Radiation Protection for Angiography Procedure.

Radiation Protection for Angiography Procedure. Fluoroscopic procedure produces the greatest patient radiation exposure rate in diagnostic radiology. Therefore the radiation protection in fluoroscopy is very important. Several feature and techniques in fluoroscopy are designed for protection to the patient during fluoroscopic procedure. a) Protection to Patient * A dead-man switch is a device (switch) constructed so that a circuit closing contact can only be maintained by continuous pressure on the switch by the operator. Therefore, when the machine is turned on by any means, whether by the push button at the control panel, or by the foot pedal, this switch must be held in for the machine to remain on. * The on-time of the fluoroscopic tube must be controlled by a timing device, and must end alarm when the exposure exceeds 5 minutes. An audible signal must alert the user to the completion of the preset on time. This signal will remain on until the timing device is reset. * The X-ray tube used for fluoroscopic must not produce X-rays unless a barrier is in position to intercept the entire cross-section of the useful beam. The fluoroscopic imaging assembly must be provided with shielding sufficient that the scatter radiation from the useful beam is minimized. * Protective barriers of at least 0.25 mm lead equivalency must be used to attenuate scatter radiation above the tabletop. This shielding does not replace the lead garments worn by personnel. Scattered radiation under the table must be attenuated by at least 0.25 mm lead equivalency shielding. * Additionally, most c-arm fluoroscopes have a warning beeper or light that activate when the beam is on, some have both. Never inactivate any warning devices, and keep ones foot off the foot pedal whenever possible. * Methods of limiting radiation exposure include: o making certain that the fluoroscopy unit is functioning properly through routine maintenance, o limiting fluoroscopic exposure time, o reducing fields of exposure through collimation, o keeping the X-ray source under the table by avoiding cross-table lateral visualization when possible, and o bringing the image intensifier down close to the patient b) Protection to personnel There are therefore three basic ways to minimize dose: * Reduce time of exposure * Use the inverse square law-doubling your distance away quarter your exposure * Use shielding by barrier These basics known as Cardinal Principle which is important to achieved ALARA. i) Time Radiation dose is directly proportional to the time, those by doubling the radiation time the dose is doubled and by having the radiation time the doses halved. Many factors impact the on time of a fluoroscopic procedure. The exposure time is related to radiation exposure and exposure rate (exposure per unit time) as follows: Exposure time = Exposure/Exposure rate Exposure = Exposure rate x time The algebraic expressions simply imply that if the exposure time is kept short, then the resulting dose to the individual is small. Method of reducing exposure time include meticulous advanced planning of the procedure, judicious use of contrast enhancement, appropriate positioning of the patient, orientation of the fluoroscope unit prior to beginning the procedure. ii) Distance The second radiation protection action relates to the distance between the source of radiation and the exposed individual. The exposure to the individual decreases inversely as the square of the distance. This is known as the inverse square law, which is stated mathematically as: where I is the intensity of radiation and d is the distance between the radiation source and the exposed individual. For example, when the distance is doubled the exposure is reduced by a factor of four. In mobile radiography, where there is no fixed protective control booth, the technologist should remain at least 2 m from the patient, the x-ray tube, and the primary beam during the exposure. In this respect, the ICRP (1982), as well as the NCRP (1989a), recommended that the length of the exposure cord on mobile radiographic units be at least 2 m long. Another important consideration with respect to distance relates to the source-to-image receptor distance (SID). The appropriate SIDs for various examinations must always be maintained because an incorrect SID could mean a second exposure to the patient. Long SID results in less divergent beam and thus decreases the concentration of photons in the patients. Short SID results in the reverse action and increases the patient dose. Hence the longest possible SID should be employed in examinations. However, if a greater than standard SID is used then greater intensity of radiation would be required to produce the same film density. Therefore it is recommended that only standard SIDs should be used. iii) Shielding Shielding procedure the most utilitarian results in the reduction of staff dose as there are times when the procedure list simply must function in close proximity, even directly cines fluoroscopy. In these circumstances there simply is no substitute for the best modern flexible lead gloves, lead glasses, lightweight lead apron and lead lined thyroid shield available. Appropriate shielding is mandatory for the safe use of ionizing radiation for medical imaging. Other method of shielding includes beam collimation, protective drapes and panels. Shielding of occupational workers can be achieved by following methods: * Personnel should remain in the radiation environment only when necessary (step behind the control booth, or leave the room when practical) * The distance between the personnel and the patient should be maximized when practical as the intensity of radiation decreases as the square of distance (inverse square law). * Shielding apparel should be used as and when necessary which comprise of lead aprons, eye glasses with side shields, hand gloves and thyroid shields. Lead aprons are shielding apparel recommended for use by radiation workers. These are classified as a secondary barrier to the effects of ionizing radiation. These aprons protect an individual only from secondary (scattered) radiation, not the primary beam. The thickness of lead in the protective apparel determines the protection it provides. It is known that 0.25 mm lead thickness attenuates 66% of the beam at 75kVp and 1mm attenuates 99% of the beam at same kVp. It is recommended that for general purpose radiography the minimum thickness of lead equivalent in the protective apparel should be 0.5mm. It is recommended that women radiation workers should wear a customized lead apron that reaches below mid thigh level and wraps completely around the pelvis. This would eliminate an accidental exposure to a concept us. Other protective apparel included eye glasses with side shields, thyroid shields and hand gloves. The minimum protective lead equivalents in hand gloves and thyroid shields should be 0.5mm. Lead lined glass and thyroid shield likewise reduce 90% of the exposure to the eyes and thyroid respectively. Lead lined gloves reduce radiation exposure to the hands; however they are no substitute for strict observation of appropriate fluoroscopic hygiene. Gloves should be considered as an effective means of reducing scatter radiation only. 2. State five clinical indications for the patient undergo the angiography procedure. 3. Explain the patient care management before, during and after the procedure Before a procedure: * Patients undergoing an angiogram are advised to stop eating and drinking eight hours prior to the procedure. * They must remove all jewelry before the procedure and change into a hospital gown. * If the arterial puncture is to be made in the armpit or groin area, shaving may be required. * A sedative may be administered to relax the patient for the procedure. * An IV line will also be inserted into a vein in the patients arm before the procedure begins in case medication or blood products are required during the angiogram. * Be aware of and follow all Local Rules and protocols * Prior to the angiography procedure, patients will be briefed on the details of the test, the benefits and risks, and the possible complications involved, and asked to sign an informed consent form. * Ensure that all exposures are justified and there is informed consent * Check patient identity * Position patient comfortably flat, with arm above head where possible * Ensure all members of staff in room are wearing suitable. For operations this should be lead glasses, thyroid collar and wrap-around lead apron * Check all staff are wearing radiation monitors correctly * Use all available lead shielding appropriately sited * Position table before screening * Keep tube current as low as possible and kVp as high as possible for cardiac studies, 60 – 90 kV is appropriate * Keep x ray tube at maximum and image intensifier / receptor at minimum distance from patient * Check all staff are as far away as possible in their role * Use dose reduction programmers when possible * Perform acquisitions on full inspiration where possible * Collimate closely to area of interest * Prolonged procedures: reduce dose to the irradiated skin eg. Change beam angulations * Minimize fluoroscopy time, high dose rate time and no of acquisitions * Remember software features, such as replay fluoro to minimize dose * Dont over use geometric magnification * Remove grid for small patients or when image intensifier / detector cannot be placed close to patient * Check and record screening time and DAP at the end of the case and review against the DRL. During the procedure: * The radiologic technologist will position you on the exam table. A radiologist a physician who specializes in the diagnostic interpretation of medical images will administer a local anesthetic and then make a small nick in your skin so that a thin catheter can be inserted into an artery or vein. The catheter is a flexible, hollow tube about the size of a strand of spaghetti. It usually is inserted into an artery in your groin, although in some cases your arm or another site will be selected for the catheter. * The radiologist will ease the catheter into the artery or vein and gently guide it to the area under investigation. The radiologist will be able to watch the movement of the catheter on a fluoroscope, which is an x-ray unit combined with a television monitor. * When the catheter reaches the area under study, the contrast agent will be injected through the catheter. By watching the fluoroscope screen, the radiologist will be able to see the outline of your blood vessels and identify any blockages or other irregularities. * Angiography procedures can range in time from less than an hour to three hours or more. It is important that you relax and remain as still as possible during the examination. The radiologic technologist and radiologist will stay in the room with you throughout the procedure. If you experience any difficulty, let them know. * Angiography also can be performed using magnetic resonance instead of x-rays to produce images of the blood vessels; this procedure is known as magnetic resonance angiography (MRA) or magnetic resonance venography (MRV). After the procedure: * Because life-threatening internal bleeding is a possible complication of an arterial puncture, an overnight stay in the hospital is sometimes recommended following an angiography procedure, particularly with cerebral and coronary angiograms. * If the procedure is performed on an outpatient basis, the patient is typically kept under close observation for a period of at six to 12 hours before being released. * If the arterial puncture was performed in the femoral artery, the patient will be instructed to keep his leg straight and relatively immobile during the observation period. * The patients blood pressure and vital signs will be monitored and the puncture site observed closely. Pain medication may be prescribed if the patient is experiencing discomfort from the puncture, and a cold pack is applied to the site to reduce swelling. It is normal for the puncture site to be sore and bruised for several weeks. * The patient may also develop a hematoma, a hard mass created by the blood vessels broken during the procedure. Hematomas should be watched carefully, as they may indicate continued bleeding of the arterial puncture site. * Angiography patients are also advised to enjoy two to three days of rest and relaxation after the procedure in order to avoid placing any undue stress on the arterial puncture. Patients who experience continued bleeding or abnormal swelling of the puncture site, sudden dizziness, or chest pains in the days following an angiography procedure should seek medical attention immediately. * Patients undergoing a fluorescein angiography should not drive or expose their eyes to direct sunlight for 12 hours following the procedure. 4. Identify the type of contrast medium, the dose and delivering technique in angiography procedure. * Reducing radiation doses to the patient also generally reduces doses to the medical personnel. Â · Angiography procedure is using fluoroscopy imaging technique which is a real-time imaging technique. 5. List down the catheters and guide wires inclusive of size, shape and the hole type that are used in angiography procedures. The use of lead gloves during procedures is unusual as they are cumbersome and difficult to work in. The automatic brightness control will increase the exposure to go through two layers and one only protects the hand, so if they are going to be used a programme that sets the radiation factors rather than allowing adjustment may be appropriate. In practice, with careful collimation and attenuation to detail it should not necessary for the operators hand to be in the primary beam and only close to it for short periods. While doing catheterization, radiologist should do it behind the lead glass viewer which consists of lead equivalent glass of 0.25mm thickness. Geometric consideration is one of the important things in angiography because source of exposure to personnel is mainly from scattered radiation from the patient. So, it is important to minimize the amount of scattered radiation to personnel. This can be achieved by geometric consideration involving the x-ray tube, patient and image intensifier. The image intensifier should be as close as possible to patient to minimize the amount of scattered radiation hitting personnel. Because in angiography room is sterile for all things, personnel such as radiologist, nurses, radiographer or student should wear shoes which are prepared only. Make sure that film badges always outside personnel body to measure the dose receive to the personnel. The most important thing to remember is that all individuals should be fully trained and learned to be responsible for radiation safety. Involvement of a radiation expert is essential and is particularly useful in equipment specification, assessment and quality assurance, but also in the formulation of Local Rules. Technique Reduces Physician Radiation Exposure During Angiography Current technique requires that physicians performing radiation procedures wear lead gowns. The new technique involves use of a body length floor mounted lead plastic panel to protect to physicians as they monitor patients angiograms and control exam table movement. An extension bar allows the physician to remain safely behind the shield and still retain table control for panning. In the study, researchers recorded radiation exposure to various parts of a physicians body during 25 coronary angiography procedures and compared those results with radiation exposure during angiography on 25 patients using conventional radiation protection. A lead apron, thyroid shield, eyeglasses and facemask were used in both techniques, but a ceiling mounted shield was used in the conventional technique. The researchers placed radiation badges outside and inside the facemask; outside and inside the thyroid shield; on the right and left arm; outside and inside the lead apron; and on the right and left leg. The new equipment resulted in a 90 percent reduction in radiation exposure to the physicians head, arms, and legs. Exposure of the thyroid and torso was minimal with both techniques. Enhanced physician radiation protection during coronary angiography is readily achievable with this new technique, said Martin Magram, M.D., of the University of Maryland Medical Center in Baltimore, Md. Dr. Magram presented the study results on May 3 at the American Roentgen Ray Society Annual Meeting in Vancouver, British Columbia. Dr. Magram pointed out that by freeing physicians from the need to wear lead gowns, the new technique could preserve their ability to benefit patients. It may extend by years their ability to apply the skills they have developed over long careers of serving patients, noted Dr. Magram. New methods of radiation protection must parallel the development of new radiation techniques, added Dr. Magram. The key is to limit medical workers radiation exposure with effective and easy-to-use techniques, and the use of this extension bar and lead plastic shield may be such a technique. Definition Angiography is the x-ray study of the blood vessels. An angiogram uses a radiopaque substance, or dye, to make the blood vessels visible under x ray. Arteriography is a type of angiography that involves the study of the arteries. Purpose Angiography is used to detect abnormalities or blockages in the blood vessels (called occlusions) throughout the circulatory system and in some organs. The procedure is commonly used to identify atherosclerosis; to diagnose heart disease; to evaluate kidney function and detect kidney cysts or tumors; to detect an aneurysm (an abnormal bulge of an artery that can rupture leading to hemorrhage), tumor, blood clot, or arteriovenous malformations (abnormals tangles of arteries and veins) in the brain; and to diagnose problems with the retina of the eye. It is also used to give surgeons an accurate map of the heart prior to open-heart surgery, or of the brain prior to neurosurgery. Precautions Patients with kidney disease or injury may suffer further kidney damage from the contrast mediums used for angiography. Patients who have blood clotting problems, have a known allergy to contrast mediums, or are allergic to iodine, a component of some contrast mediums, may also not be suitable candidates for an angiography procedure. Because x rays carry risks of ionizing radiation exposure to the fetus, pregnant women are also advised to avoid this procedure. Description Angiography is usually performed at a hospital by a trained radiologist and assisting technician or nurse. It takes place in an x-ray or fluoroscopy suite, and for most types of angiograms, the patients vital signs will be monitored throughout the procedure. Angiography requires the injection of a contrast dye that makes the blood vessels visible to x ray. The dye is injected through a procedure known as arterial puncture. The puncture is usually made in the groin area, armpit, inside elbow, or neck. The site is cleaned with an antiseptic agent and injected with a local anesthetic. First, a small incision is made in the skin to help the needle pass. A needle containing an inner wire called a stylet is inserted through the skin into the artery. When the radiologist has punctured the artery with the needle, the stylet is removed and replaced with another long wire called a guide wire. It is normal for blood to spout out of the needle before the guide wire is inserted. The guide wire is fed through the outer needle into the artery and to the area that requires angiographic study. A fluoroscopic screen that displays a view of the patients vascular system is used to pilot the wire to the correct location. Once it is in position, the needle is removed and a catheter is slid over the length of the guide wire until it to reaches the area of study. The guide wire is removed and the catheter is left in place in preparation for the injection of the contrast medium, or dye. Depending on the type of angiography procedure being performed, the contrast medium is either injected by hand with a syringe or is mechanically injected with an automatic injector connected to the catheter. An automatic injector is used frequently because it is able to propel a large volume of dye very quickly to the angiogram site. The patient is warned that the injection will start, and instructed to remain very still. The injection causes some mild to moderate discomfort. Possible side effects or reactions include headache, dizziness, irregular heartbeat, nausea, warmth, burning sensation, and chest pain, but they usually last only momentarily. To view the area of study from different angles or perspectives, the patient may be asked to change positions several times, and subsequent dye injections may be administered. During any injection, the patient or the camera may move. Throughout the dye injection procedure, x-ray pictures and/or fluoroscopic pictures (or moving x rays) will be taken. Because of the high pressure of arterial blood flow, the dye will dissipate through the patients system quickly, so pictures must be taken in rapid succession. An automatic film changer is used because the manual changing of x-ray plates can eat up valuable time. Once the x rays are complete, the catheter is slowly and carefully removed from the patient. Pressure is applied to the site with a sandbag or other weight for 10-20 minutes in order for clotting to take place and the arterial puncture to reseal itself. A pressure bandage is then applied. Most angiograms follow the general procedures outlined above, but vary slightly depending on the area of the vascular system being studied. A variety of common angiography procedures are outlined below: Cerebral angiography Cerebral angiography is used to detect aneurysms, blood clots, and other vascular irregularities in the brain. The catheter is inserted into the femoral or carotid artery and the injected contrast medium travels through the blood vessels on the brain. Patients frequently experience headache, warmth, or a burning sensation in the head or neck during the injection portion of the procedure. A cerebral angiogram takes two to four hours to complete. Coronary angiography Coronary angiography is administered by a cardiologist with training in radiology or, occasionally, by a radiologist. The arterial puncture is typically given in the femoral artery, and the cardiologist uses a guide wire and catheter to perform a contrast injection and x-ray series on the coronary arteries. The catheter may also be placed in the left ventricle to examine the mitral and aortic valves of the heart. If the cardiologist requires a view of the right ventricle of the heart or of the tricuspid or pulmonic valves, the catheter will be inserted through a large vein and guided into the right ventricle. The catheter also serves the purpose of monitoring blood pressures in these different locations inside the heart. The angiogram procedure takes several hours, depending on the complexity of the procedure. Pulmonary angiography Pulmonary, or lung, angiography is performed to evaluate blood circulation to the lungs. It is also considered the most accurate diagnostic test for detecting a pulmonary embolism. The procedure differs from cerebral and coronary angiograms in that the guide wire and catheter are inserted into a vein instead of an artery, and are guided up through the chambers of the heart and into the pulmonary artery. Throughout the procedure, the patients vital signs are monitored to ensure that the catheter doesnt cause arrhythmias, or irregular heartbeats. The contrast medium is then injected into the pulmonary artery where it circulates through the lung capillaries. The test typically takes up to 90 minutes. Kidney angiography Patients with chronic renal disease or injury can suffer further damage to their kidneys from the contrast medium used in a kidney angiogram, yet they often require the test to evaluate kidney function. These patients should be well-hydrated with a intravenous saline drip before the procedure, and may benefit from available medications (e.g., dopamine) that help to protect the kidney from further injury due to contrast agents. During a kidney angiogram, the guide wire and catheter are inserted into the femoral artery in the groin area and advanced through the abdominal aorta, the main artery in the abdomen, and into the renal arteries. The procedure will take approximately one hour. Fluorescein angiography Fluorescein angiography is used to diagnose retinal problems and circulatory disorders. It is typically conducted as an outpatient procedure. The patients pupils are dilated with eye drops and he rests his chin and forehead against a bracing apparatus to keep it still. Sodium fluorescein dye is then injected with a syringe into a vein in the patients arm. The dye will travel through the patients body and into the blood vessels of the eye. The procedure does not require x rays. Instead, a rapid series of close-up photographs of the patients eyes are taken, one set immediately after the dye is injected, and a second set approximately 20 minutes later once the dye has moved through the patients vascular system. The entire procedure takes up to one hour. Celiac and mesenteric angiography Celiac and mesenteric angiography involves x-ray exploration of the celiac and mesenteric arteries, arterial branches of the abdominal aorta that supply blood to the abdomen and digestive system. The test is commonly used to detect aneurysm, thrombosis, and signs of ischemia in the celiac and mesenteric arteries, and to locate the source of gastrointestinal bleeding. It is also used in the diagnosis of a number of conditions, including portal hypertension, and cirrhosis. The procedure can take up to three hours, depending on the number of blood vessels studied. Splenoportography A splenoportograph is a variation of an angiogram that involves the injection of contrast medium directly into the spleen to view the splenic and portal veins. It is used to diagnose blockages in the splenic vein and portal vein thrombosis and to assess the strength and location of the vascular system prior to liver transplantation. Most angiography procedures are typically paid for by major medical insurance. Patients should check with their individual insurance plans to determine their coverage. Aftercare Risks Because angiography involves puncturing an artery, internal bleeding or hemorrhage are possible complications of the test. As with any invasive procedure, infection of the puncture site or bloodstream is also a risk, but this is rare. A stroke or heart attack may be triggered by an angiogram if blood clots or plaque on the inside of the arterial wall are dislodged by the catheter and form a blockage in the blood vessels or artery. The heart may also become irritated by the movement of the catheter through its chambers during pulmonary and coronary angiography procedures, and arrhythmias may develop. Patients who develop an allergic reaction to the contrast medium used in angiography may experience a variety of symptoms, including swelling, difficulty breathing, heart failure, or a sudden drop in blood pressure. If the patient is aware of the allergy before the test is administered, certain medications can be administered at that time to counteract the reaction. Angiography involves minor exposure to radiation through the x rays and fluoroscopic guidance used in the procedure. Unless the patient is pregnant, or multiple radiological or fluoroscopic studies are required, the small dose of radiation incurred during a single procedure poses little risk. However, multiple studies requiring fluoroscopic exposure that are conducted in a short time period have been known to cause skin necrosis in some individuals. This risk can be minimized by careful monitoring and documentation of cumulative radiation doses administered to these patients. Normal results The results of an angiogram or arteriogram depend on the artery or organ system being examined. Generally, test results should display a normal and unimpeded flow of blood through the vascular system. Fluorescein angiography should result in no leakage of fluorescein dye through the retinal blood vessels. Abnormal results Abnormal results of an angiography may display a restricted blood vessel or arterial blood flow (ischemia) or an irregular placement or location of blood vessels. The results of an angiography vary widely by the type of procedure performed, and should be interpreted and explained to the patient by a trained radiologist. Arteriosclerosis A chronic condition characterized by thickening and hardening of the arteries and the build-up of plaque on the arterial walls. Arteriosclerosis can slow or impair blood circulation. Carotid artery An artery located in the neck. Catheter A long, thin, flexible tube used in angiography to inject contrast material into the arteries. Cirrhosis A condition characterized by the destruction of healthy liver tissue. A cirrhotic liver is scarred and cannot break down the proteins in the bloodstream. Cirrhosis is associated with portal hypertension. Embolism A blood clot, air bubble, or clot of foreign material that travels and blocks the flow of blood in an artery. When blood supply to a tissue or organ is blocked by an embolism, infarction, or death of the tissue the artery feeds, occurs. Without immediate and appropriate treatment, an embolism can be fatal. Femoral artery An artery located in the groin area that is the most frequently accessed site for arterial puncture in angiography. Fluorescein dye An orange dye used to illuminate the blood vessels of the retina in fluorescein angiography. Fluoroscopic screen A fluorescent screen which displays moving x-rays of the body. Fluoroscopy allows the radiologist to visualize the guide wire and catheter he is moving through the patients artery. Guide wire A wire that is inserted into an artery to guides a catheter to a certain location in the body. Iscehmia A lack of normal blood supply to a organ or body part because of blockages or constriction of the blood vessels. Necrosis Cellular or tissue death; skin necrosis may be caused by multiple, consecutive doses of radiation from fluoroscopic or x-ray procedures. Plaque Fatty material that is deposited on the inside of the arterial wall. Portal hypertension A condition caused by cirrhosis of the liver. It is characterized by impaired or reversed blood flow from the portal vein to the liver, an enlarged spleen, and dilated veins in the esophagus and stomach. Portal vein thrombosis The development of a blood clot in the vein that brings blood into the liver. Untreated portal vein thrombosis causes portal hypertension. For Your Information Books * Baum, Stanley, and Michael J. Pentecost, eds. Abrams Angiography. 4th ed. Radiation Protection for Angiography Procedure. Radiation Protection for Angiography Procedure. Fluoroscopic procedure produces the greatest patient radiation exposure rate in diagnostic radiology. Therefore the radiation protection in fluoroscopy is very important. Several feature and techniques in fluoroscopy are designed for protection to the patient during fluoroscopic procedure. a) Protection to Patient * A dead-man switch is a device (switch) constructed so that a circuit closing contact can only be maintained by continuous pressure on the switch by the operator. Therefore, when the machine is turned on by any means, whether by the push button at the control panel, or by the foot pedal, this switch must be held in for the machine to remain on. * The on-time of the fluoroscopic tube must be controlled by a timing device, and must end alarm when the exposure exceeds 5 minutes. An audible signal must alert the user to the completion of the preset on time. This signal will remain on until the timing device is reset. * The X-ray tube used for fluoroscopic must not produce X-rays unless a barrier is in position to intercept the entire cross-section of the useful beam. The fluoroscopic imaging assembly must be provided with shielding sufficient that the scatter radiation from the useful beam is minimized. * Protective barriers of at least 0.25 mm lead equivalency must be used to attenuate scatter radiation above the tabletop. This shielding does not replace the lead garments worn by personnel. Scattered radiation under the table must be attenuated by at least 0.25 mm lead equivalency shielding. * Additionally, most c-arm fluoroscopes have a warning beeper or light that activate when the beam is on, some have both. Never inactivate any warning devices, and keep ones foot off the foot pedal whenever possible. * Methods of limiting radiation exposure include: o making certain that the fluoroscopy unit is functioning properly through routine maintenance, o limiting fluoroscopic exposure time, o reducing fields of exposure through collimation, o keeping the X-ray source under the table by avoiding cross-table lateral visualization when possible, and o bringing the image intensifier down close to the patient b) Protection to personnel There are therefore three basic ways to minimize dose: * Reduce time of exposure * Use the inverse square law-doubling your distance away quarter your exposure * Use shielding by barrier These basics known as Cardinal Principle which is important to achieved ALARA. i) Time Radiation dose is directly proportional to the time, those by doubling the radiation time the dose is doubled and by having the radiation time the doses halved. Many factors impact the on time of a fluoroscopic procedure. The exposure time is related to radiation exposure and exposure rate (exposure per unit time) as follows: Exposure time = Exposure/Exposure rate Exposure = Exposure rate x time The algebraic expressions simply imply that if the exposure time is kept short, then the resulting dose to the individual is small. Method of reducing exposure time include meticulous advanced planning of the procedure, judicious use of contrast enhancement, appropriate positioning of the patient, orientation of the fluoroscope unit prior to beginning the procedure. ii) Distance The second radiation protection action relates to the distance between the source of radiation and the exposed individual. The exposure to the individual decreases inversely as the square of the distance. This is known as the inverse square law, which is stated mathematically as: where I is the intensity of radiation and d is the distance between the radiation source and the exposed individual. For example, when the distance is doubled the exposure is reduced by a factor of four. In mobile radiography, where there is no fixed protective control booth, the technologist should remain at least 2 m from the patient, the x-ray tube, and the primary beam during the exposure. In this respect, the ICRP (1982), as well as the NCRP (1989a), recommended that the length of the exposure cord on mobile radiographic units be at least 2 m long. Another important consideration with respect to distance relates to the source-to-image receptor distance (SID). The appropriate SIDs for various examinations must always be maintained because an incorrect SID could mean a second exposure to the patient. Long SID results in less divergent beam and thus decreases the concentration of photons in the patients. Short SID results in the reverse action and increases the patient dose. Hence the longest possible SID should be employed in examinations. However, if a greater than standard SID is used then greater intensity of radiation would be required to produce the same film density. Therefore it is recommended that only standard SIDs should be used. iii) Shielding Shielding procedure the most utilitarian results in the reduction of staff dose as there are times when the procedure list simply must function in close proximity, even directly cines fluoroscopy. In these circumstances there simply is no substitute for the best modern flexible lead gloves, lead glasses, lightweight lead apron and lead lined thyroid shield available. Appropriate shielding is mandatory for the safe use of ionizing radiation for medical imaging. Other method of shielding includes beam collimation, protective drapes and panels. Shielding of occupational workers can be achieved by following methods: * Personnel should remain in the radiation environment only when necessary (step behind the control booth, or leave the room when practical) * The distance between the personnel and the patient should be maximized when practical as the intensity of radiation decreases as the square of distance (inverse square law). * Shielding apparel should be used as and when necessary which comprise of lead aprons, eye glasses with side shields, hand gloves and thyroid shields. Lead aprons are shielding apparel recommended for use by radiation workers. These are classified as a secondary barrier to the effects of ionizing radiation. These aprons protect an individual only from secondary (scattered) radiation, not the primary beam. The thickness of lead in the protective apparel determines the protection it provides. It is known that 0.25 mm lead thickness attenuates 66% of the beam at 75kVp and 1mm attenuates 99% of the beam at same kVp. It is recommended that for general purpose radiography the minimum thickness of lead equivalent in the protective apparel should be 0.5mm. It is recommended that women radiation workers should wear a customized lead apron that reaches below mid thigh level and wraps completely around the pelvis. This would eliminate an accidental exposure to a concept us. Other protective apparel included eye glasses with side shields, thyroid shields and hand gloves. The minimum protective lead equivalents in hand gloves and thyroid shields should be 0.5mm. Lead lined glass and thyroid shield likewise reduce 90% of the exposure to the eyes and thyroid respectively. Lead lined gloves reduce radiation exposure to the hands; however they are no substitute for strict observation of appropriate fluoroscopic hygiene. Gloves should be considered as an effective means of reducing scatter radiation only. 2. State five clinical indications for the patient undergo the angiography procedure. 3. Explain the patient care management before, during and after the procedure Before a procedure: * Patients undergoing an angiogram are advised to stop eating and drinking eight hours prior to the procedure. * They must remove all jewelry before the procedure and change into a hospital gown. * If the arterial puncture is to be made in the armpit or groin area, shaving may be required. * A sedative may be administered to relax the patient for the procedure. * An IV line will also be inserted into a vein in the patients arm before the procedure begins in case medication or blood products are required during the angiogram. * Be aware of and follow all Local Rules and protocols * Prior to the angiography procedure, patients will be briefed on the details of the test, the benefits and risks, and the possible complications involved, and asked to sign an informed consent form. * Ensure that all exposures are justified and there is informed consent * Check patient identity * Position patient comfortably flat, with arm above head where possible * Ensure all members of staff in room are wearing suitable. For operations this should be lead glasses, thyroid collar and wrap-around lead apron * Check all staff are wearing radiation monitors correctly * Use all available lead shielding appropriately sited * Position table before screening * Keep tube current as low as possible and kVp as high as possible for cardiac studies, 60 – 90 kV is appropriate * Keep x ray tube at maximum and image intensifier / receptor at minimum distance from patient * Check all staff are as far away as possible in their role * Use dose reduction programmers when possible * Perform acquisitions on full inspiration where possible * Collimate closely to area of interest * Prolonged procedures: reduce dose to the irradiated skin eg. Change beam angulations * Minimize fluoroscopy time, high dose rate time and no of acquisitions * Remember software features, such as replay fluoro to minimize dose * Dont over use geometric magnification * Remove grid for small patients or when image intensifier / detector cannot be placed close to patient * Check and record screening time and DAP at the end of the case and review against the DRL. During the procedure: * The radiologic technologist will position you on the exam table. A radiologist a physician who specializes in the diagnostic interpretation of medical images will administer a local anesthetic and then make a small nick in your skin so that a thin catheter can be inserted into an artery or vein. The catheter is a flexible, hollow tube about the size of a strand of spaghetti. It usually is inserted into an artery in your groin, although in some cases your arm or another site will be selected for the catheter. * The radiologist will ease the catheter into the artery or vein and gently guide it to the area under investigation. The radiologist will be able to watch the movement of the catheter on a fluoroscope, which is an x-ray unit combined with a television monitor. * When the catheter reaches the area under study, the contrast agent will be injected through the catheter. By watching the fluoroscope screen, the radiologist will be able to see the outline of your blood vessels and identify any blockages or other irregularities. * Angiography procedures can range in time from less than an hour to three hours or more. It is important that you relax and remain as still as possible during the examination. The radiologic technologist and radiologist will stay in the room with you throughout the procedure. If you experience any difficulty, let them know. * Angiography also can be performed using magnetic resonance instead of x-rays to produce images of the blood vessels; this procedure is known as magnetic resonance angiography (MRA) or magnetic resonance venography (MRV). After the procedure: * Because life-threatening internal bleeding is a possible complication of an arterial puncture, an overnight stay in the hospital is sometimes recommended following an angiography procedure, particularly with cerebral and coronary angiograms. * If the procedure is performed on an outpatient basis, the patient is typically kept under close observation for a period of at six to 12 hours before being released. * If the arterial puncture was performed in the femoral artery, the patient will be instructed to keep his leg straight and relatively immobile during the observation period. * The patients blood pressure and vital signs will be monitored and the puncture site observed closely. Pain medication may be prescribed if the patient is experiencing discomfort from the puncture, and a cold pack is applied to the site to reduce swelling. It is normal for the puncture site to be sore and bruised for several weeks. * The patient may also develop a hematoma, a hard mass created by the blood vessels broken during the procedure. Hematomas should be watched carefully, as they may indicate continued bleeding of the arterial puncture site. * Angiography patients are also advised to enjoy two to three days of rest and relaxation after the procedure in order to avoid placing any undue stress on the arterial puncture. Patients who experience continued bleeding or abnormal swelling of the puncture site, sudden dizziness, or chest pains in the days following an angiography procedure should seek medical attention immediately. * Patients undergoing a fluorescein angiography should not drive or expose their eyes to direct sunlight for 12 hours following the procedure. 4. Identify the type of contrast medium, the dose and delivering technique in angiography procedure. * Reducing radiation doses to the patient also generally reduces doses to the medical personnel. Â · Angiography procedure is using fluoroscopy imaging technique which is a real-time imaging technique. 5. List down the catheters and guide wires inclusive of size, shape and the hole type that are used in angiography procedures. The use of lead gloves during procedures is unusual as they are cumbersome and difficult to work in. The automatic brightness control will increase the exposure to go through two layers and one only protects the hand, so if they are going to be used a programme that sets the radiation factors rather than allowing adjustment may be appropriate. In practice, with careful collimation and attenuation to detail it should not necessary for the operators hand to be in the primary beam and only close to it for short periods. While doing catheterization, radiologist should do it behind the lead glass viewer which consists of lead equivalent glass of 0.25mm thickness. Geometric consideration is one of the important things in angiography because source of exposure to personnel is mainly from scattered radiation from the patient. So, it is important to minimize the amount of scattered radiation to personnel. This can be achieved by geometric consideration involving the x-ray tube, patient and image intensifier. The image intensifier should be as close as possible to patient to minimize the amount of scattered radiation hitting personnel. Because in angiography room is sterile for all things, personnel such as radiologist, nurses, radiographer or student should wear shoes which are prepared only. Make sure that film badges always outside personnel body to measure the dose receive to the personnel. The most important thing to remember is that all individuals should be fully trained and learned to be responsible for radiation safety. Involvement of a radiation expert is essential and is particularly useful in equipment specification, assessment and quality assurance, but also in the formulation of Local Rules. Technique Reduces Physician Radiation Exposure During Angiography Current technique requires that physicians performing radiation procedures wear lead gowns. The new technique involves use of a body length floor mounted lead plastic panel to protect to physicians as they monitor patients angiograms and control exam table movement. An extension bar allows the physician to remain safely behind the shield and still retain table control for panning. In the study, researchers recorded radiation exposure to various parts of a physicians body during 25 coronary angiography procedures and compared those results with radiation exposure during angiography on 25 patients using conventional radiation protection. A lead apron, thyroid shield, eyeglasses and facemask were used in both techniques, but a ceiling mounted shield was used in the conventional technique. The researchers placed radiation badges outside and inside the facemask; outside and inside the thyroid shield; on the right and left arm; outside and inside the lead apron; and on the right and left leg. The new equipment resulted in a 90 percent reduction in radiation exposure to the physicians head, arms, and legs. Exposure of the thyroid and torso was minimal with both techniques. Enhanced physician radiation protection during coronary angiography is readily achievable with this new technique, said Martin Magram, M.D., of the University of Maryland Medical Center in Baltimore, Md. Dr. Magram presented the study results on May 3 at the American Roentgen Ray Society Annual Meeting in Vancouver, British Columbia. Dr. Magram pointed out that by freeing physicians from the need to wear lead gowns, the new technique could preserve their ability to benefit patients. It may extend by years their ability to apply the skills they have developed over long careers of serving patients, noted Dr. Magram. New methods of radiation protection must parallel the development of new radiation techniques, added Dr. Magram. The key is to limit medical workers radiation exposure with effective and easy-to-use techniques, and the use of this extension bar and lead plastic shield may be such a technique. Definition Angiography is the x-ray study of the blood vessels. An angiogram uses a radiopaque substance, or dye, to make the blood vessels visible under x ray. Arteriography is a type of angiography that involves the study of the arteries. Purpose Angiography is used to detect abnormalities or blockages in the blood vessels (called occlusions) throughout the circulatory system and in some organs. The procedure is commonly used to identify atherosclerosis; to diagnose heart disease; to evaluate kidney function and detect kidney cysts or tumors; to detect an aneurysm (an abnormal bulge of an artery that can rupture leading to hemorrhage), tumor, blood clot, or arteriovenous malformations (abnormals tangles of arteries and veins) in the brain; and to diagnose problems with the retina of the eye. It is also used to give surgeons an accurate map of the heart prior to open-heart surgery, or of the brain prior to neurosurgery. Precautions Patients with kidney disease or injury may suffer further kidney damage from the contrast mediums used for angiography. Patients who have blood clotting problems, have a known allergy to contrast mediums, or are allergic to iodine, a component of some contrast mediums, may also not be suitable candidates for an angiography procedure. Because x rays carry risks of ionizing radiation exposure to the fetus, pregnant women are also advised to avoid this procedure. Description Angiography is usually performed at a hospital by a trained radiologist and assisting technician or nurse. It takes place in an x-ray or fluoroscopy suite, and for most types of angiograms, the patients vital signs will be monitored throughout the procedure. Angiography requires the injection of a contrast dye that makes the blood vessels visible to x ray. The dye is injected through a procedure known as arterial puncture. The puncture is usually made in the groin area, armpit, inside elbow, or neck. The site is cleaned with an antiseptic agent and injected with a local anesthetic. First, a small incision is made in the skin to help the needle pass. A needle containing an inner wire called a stylet is inserted through the skin into the artery. When the radiologist has punctured the artery with the needle, the stylet is removed and replaced with another long wire called a guide wire. It is normal for blood to spout out of the needle before the guide wire is inserted. The guide wire is fed through the outer needle into the artery and to the area that requires angiographic study. A fluoroscopic screen that displays a view of the patients vascular system is used to pilot the wire to the correct location. Once it is in position, the needle is removed and a catheter is slid over the length of the guide wire until it to reaches the area of study. The guide wire is removed and the catheter is left in place in preparation for the injection of the contrast medium, or dye. Depending on the type of angiography procedure being performed, the contrast medium is either injected by hand with a syringe or is mechanically injected with an automatic injector connected to the catheter. An automatic injector is used frequently because it is able to propel a large volume of dye very quickly to the angiogram site. The patient is warned that the injection will start, and instructed to remain very still. The injection causes some mild to moderate discomfort. Possible side effects or reactions include headache, dizziness, irregular heartbeat, nausea, warmth, burning sensation, and chest pain, but they usually last only momentarily. To view the area of study from different angles or perspectives, the patient may be asked to change positions several times, and subsequent dye injections may be administered. During any injection, the patient or the camera may move. Throughout the dye injection procedure, x-ray pictures and/or fluoroscopic pictures (or moving x rays) will be taken. Because of the high pressure of arterial blood flow, the dye will dissipate through the patients system quickly, so pictures must be taken in rapid succession. An automatic film changer is used because the manual changing of x-ray plates can eat up valuable time. Once the x rays are complete, the catheter is slowly and carefully removed from the patient. Pressure is applied to the site with a sandbag or other weight for 10-20 minutes in order for clotting to take place and the arterial puncture to reseal itself. A pressure bandage is then applied. Most angiograms follow the general procedures outlined above, but vary slightly depending on the area of the vascular system being studied. A variety of common angiography procedures are outlined below: Cerebral angiography Cerebral angiography is used to detect aneurysms, blood clots, and other vascular irregularities in the brain. The catheter is inserted into the femoral or carotid artery and the injected contrast medium travels through the blood vessels on the brain. Patients frequently experience headache, warmth, or a burning sensation in the head or neck during the injection portion of the procedure. A cerebral angiogram takes two to four hours to complete. Coronary angiography Coronary angiography is administered by a cardiologist with training in radiology or, occasionally, by a radiologist. The arterial puncture is typically given in the femoral artery, and the cardiologist uses a guide wire and catheter to perform a contrast injection and x-ray series on the coronary arteries. The catheter may also be placed in the left ventricle to examine the mitral and aortic valves of the heart. If the cardiologist requires a view of the right ventricle of the heart or of the tricuspid or pulmonic valves, the catheter will be inserted through a large vein and guided into the right ventricle. The catheter also serves the purpose of monitoring blood pressures in these different locations inside the heart. The angiogram procedure takes several hours, depending on the complexity of the procedure. Pulmonary angiography Pulmonary, or lung, angiography is performed to evaluate blood circulation to the lungs. It is also considered the most accurate diagnostic test for detecting a pulmonary embolism. The procedure differs from cerebral and coronary angiograms in that the guide wire and catheter are inserted into a vein instead of an artery, and are guided up through the chambers of the heart and into the pulmonary artery. Throughout the procedure, the patients vital signs are monitored to ensure that the catheter doesnt cause arrhythmias, or irregular heartbeats. The contrast medium is then injected into the pulmonary artery where it circulates through the lung capillaries. The test typically takes up to 90 minutes. Kidney angiography Patients with chronic renal disease or injury can suffer further damage to their kidneys from the contrast medium used in a kidney angiogram, yet they often require the test to evaluate kidney function. These patients should be well-hydrated with a intravenous saline drip before the procedure, and may benefit from available medications (e.g., dopamine) that help to protect the kidney from further injury due to contrast agents. During a kidney angiogram, the guide wire and catheter are inserted into the femoral artery in the groin area and advanced through the abdominal aorta, the main artery in the abdomen, and into the renal arteries. The procedure will take approximately one hour. Fluorescein angiography Fluorescein angiography is used to diagnose retinal problems and circulatory disorders. It is typically conducted as an outpatient procedure. The patients pupils are dilated with eye drops and he rests his chin and forehead against a bracing apparatus to keep it still. Sodium fluorescein dye is then injected with a syringe into a vein in the patients arm. The dye will travel through the patients body and into the blood vessels of the eye. The procedure does not require x rays. Instead, a rapid series of close-up photographs of the patients eyes are taken, one set immediately after the dye is injected, and a second set approximately 20 minutes later once the dye has moved through the patients vascular system. The entire procedure takes up to one hour. Celiac and mesenteric angiography Celiac and mesenteric angiography involves x-ray exploration of the celiac and mesenteric arteries, arterial branches of the abdominal aorta that supply blood to the abdomen and digestive system. The test is commonly used to detect aneurysm, thrombosis, and signs of ischemia in the celiac and mesenteric arteries, and to locate the source of gastrointestinal bleeding. It is also used in the diagnosis of a number of conditions, including portal hypertension, and cirrhosis. The procedure can take up to three hours, depending on the number of blood vessels studied. Splenoportography A splenoportograph is a variation of an angiogram that involves the injection of contrast medium directly into the spleen to view the splenic and portal veins. It is used to diagnose blockages in the splenic vein and portal vein thrombosis and to assess the strength and location of the vascular system prior to liver transplantation. Most angiography procedures are typically paid for by major medical insurance. Patients should check with their individual insurance plans to determine their coverage. Aftercare Risks Because angiography involves puncturing an artery, internal bleeding or hemorrhage are possible complications of the test. As with any invasive procedure, infection of the puncture site or bloodstream is also a risk, but this is rare. A stroke or heart attack may be triggered by an angiogram if blood clots or plaque on the inside of the arterial wall are dislodged by the catheter and form a blockage in the blood vessels or artery. The heart may also become irritated by the movement of the catheter through its chambers during pulmonary and coronary angiography procedures, and arrhythmias may develop. Patients who develop an allergic reaction to the contrast medium used in angiography may experience a variety of symptoms, including swelling, difficulty breathing, heart failure, or a sudden drop in blood pressure. If the patient is aware of the allergy before the test is administered, certain medications can be administered at that time to counteract the reaction. Angiography involves minor exposure to radiation through the x rays and fluoroscopic guidance used in the procedure. Unless the patient is pregnant, or multiple radiological or fluoroscopic studies are required, the small dose of radiation incurred during a single procedure poses little risk. However, multiple studies requiring fluoroscopic exposure that are conducted in a short time period have been known to cause skin necrosis in some individuals. This risk can be minimized by careful monitoring and documentation of cumulative radiation doses administered to these patients. Normal results The results of an angiogram or arteriogram depend on the artery or organ system being examined. Generally, test results should display a normal and unimpeded flow of blood through the vascular system. Fluorescein angiography should result in no leakage of fluorescein dye through the retinal blood vessels. Abnormal results Abnormal results of an angiography may display a restricted blood vessel or arterial blood flow (ischemia) or an irregular placement or location of blood vessels. The results of an angiography vary widely by the type of procedure performed, and should be interpreted and explained to the patient by a trained radiologist. Arteriosclerosis A chronic condition characterized by thickening and hardening of the arteries and the build-up of plaque on the arterial walls. Arteriosclerosis can slow or impair blood circulation. Carotid artery An artery located in the neck. Catheter A long, thin, flexible tube used in angiography to inject contrast material into the arteries. Cirrhosis A condition characterized by the destruction of healthy liver tissue. A cirrhotic liver is scarred and cannot break down the proteins in the bloodstream. Cirrhosis is associated with portal hypertension. Embolism A blood clot, air bubble, or clot of foreign material that travels and blocks the flow of blood in an artery. When blood supply to a tissue or organ is blocked by an embolism, infarction, or death of the tissue the artery feeds, occurs. Without immediate and appropriate treatment, an embolism can be fatal. Femoral artery An artery located in the groin area that is the most frequently accessed site for arterial puncture in angiography. Fluorescein dye An orange dye used to illuminate the blood vessels of the retina in fluorescein angiography. Fluoroscopic screen A fluorescent screen which displays moving x-rays of the body. Fluoroscopy allows the radiologist to visualize the guide wire and catheter he is moving through the patients artery. Guide wire A wire that is inserted into an artery to guides a catheter to a certain location in the body. Iscehmia A lack of normal blood supply to a organ or body part because of blockages or constriction of the blood vessels. Necrosis Cellular or tissue death; skin necrosis may be caused by multiple, consecutive doses of radiation from fluoroscopic or x-ray procedures. Plaque Fatty material that is deposited on the inside of the arterial wall. Portal hypertension A condition caused by cirrhosis of the liver. It is characterized by impaired or reversed blood flow from the portal vein to the liver, an enlarged spleen, and dilated veins in the esophagus and stomach. Portal vein thrombosis The development of a blood clot in the vein that brings blood into the liver. Untreated portal vein thrombosis causes portal hypertension. For Your Information Books * Baum, Stanley, and Michael J. Pentecost, eds. Abrams Angiography. 4th ed.

Analysis Of The Bridge Of San :: essays research papers

People who thinks of Thornton Wilder primarily in terms of his classic novella â€Å"Our Town,† The Bridge of San Luis Rey will seem like quite a switch. For one thing, he has switched countries; instead of middle America, he deals here with Peru. He has switched eras, moving from the twentieth century back to the eighteenth. He has also dealt with a much broader society than he did in â€Å"Our Town,† representing the lower classes and the aristocracy with equal ease. But despite these differences, his theme is much the same; life is short, our expectations can be snuffed out with the snap of a finger, and in the end all that remains of us is those we have loved. The novella begins by describing the quest of a Franciscan monk, Brother Juniper, to figure out why some people’s lives are cut short while others, apparently less deserving of life, live well into their eighties and nineties. He has happened to witness a terrible accident (the sudden collapse of a national landmark, the Bridge of San Luis Rey) which five people were crossing at the time of the disaster. All five were killed instantly: a little boy, a young girl, a wealthy old woman, an old man, and a youth. Brother Juniper is shocked into a metaphysical thought: â€Å"If there were any pattern in the universe at all, any plan in a human life, surely it could be discovered mysteriously latent in those lives so suddenly cut off. Either we live by accident and die by accident, or we live by plan and die by plan. And in that instant Brother Juniper made the resolve to inquire into the secret lives of those five persons, that moment falling through the air, and to surprise the reason of their taking off† (Wilder, 5). This is the wonderful premise behind Wilder’s examination of the connected lives of these five people. Several of them never actually meet, any more than we â€Å"meet† people with whom we happen to ride an elevator but, each of them knows someone who knows one of the other victims. Wilder goes on to clear up the stories of their lives, devoting a chapter to each of the major characters: The old woman, The Marquesa; The young man, Esteban; and the old man, Uncle Pio. (The other two victims, the young maid Pepita and the child Jaime, are not really explored, because they are seen primarily in relationship to the adults they accompany.

Save the Arts :: essays research papers

Within the past few years, the government has been taking major strides to improve the education system by increasing the funding for our school systems and programs. They are increasing the school?s funding by taking away the funds from the art, dance, and theatre classes, among other programs. As a student raised in the atmosphere of the arts and a student now majoring in theatre, I feel very strongly that the government is making a major mistake by taking money away from the arts.   Ã‚  Ã‚  Ã‚  Ã‚  The arts should be supported because children earn a great deal of self-confidence by being involved in the arts. The children?s self-confidence level is increased through the arts because children are more free to express how they really feel in any and all situations. In the completion of a project, generally there will be some sort of reward, whether applause or recognition for a job well done. The rewards make children feel special, valuable, and important. All of the recognition and support that is received through the arts make it quite easy for a child to gain great self-confidence.   Ã‚  Ã‚  Ã‚  Ã‚  The arts also help children to improve their social skills. Being involved in the arts teaches one teamwork. Through these fine art groups and activities one will learn to do their best as an individual, yet come together with others in order to put on the best show possible. Teamwork is a great way to teach a child the social skills which indeed, are needed to carry them through life.   Ã‚  Ã‚  Ã‚  Ã‚  Children involved in the arts learn a great sense of responsibility. Children are already responsible for a lot in school, but when they are involved in the arts, not only do they have to make time for homework, but also make time for their lessons and rehearsals that go along with being involved in the arts. These children work hard, and are pushed to be all they can be, and they truly learn what it is like to be responsible.   Ã‚  Ã‚  Ã‚  Ã‚  Children in the arts learn three of lives most important skills: self-confidence, social skills, and a sense of responsibility. These skills cannot be taught in a class or out of a book, but one must learn it for themselves by taking part in something that teaches them these skills.

Anthony Trollope’s He Knew He Was Right :: Morals Happiness Struggles Papers

Anthony Trollope’s He Knew He Was Right Anthony Trollope’s He Knew He Was Right is unique among the prolific writer’s novels in having as its title a complete declarative sentence. Such a title stands as a sort of challenge to the reader: it invites us, as we make our way through the novel’s densely detailed presentation of lived reality, to consider the relation between that reality and the proposition put forward in the title sentence. What does it mean to say that Louis Trevelyan â€Å"knew he was right†? Even if we are unconvinced by J. Hillis Miller’s argument that â€Å"a long multi-plotted novel like He Knew He Was Right, with all its wealth and particularity of character, incident, realistic detail, may be an exploration of a single ‘complex word’† (Miller 77), Trollope’s choice of title inevitably throws us back, as we attempt to make sense of the events narrated under that title, on questions of moral epistemology; that is, it compels reflection on ho w we know what is right and on the extent to which we can be secure in that knowledge. Obliged to read the narrative as, among other things, a meditation on â€Å"knowing† and on â€Å"rightness,† we can perceive that Trollope’s concern here is with the manner in which his characters come to possess certainty in their moral judgments, with the process by which they acquire the disposition towards what is â€Å"right† that we can label â€Å"virtue.† â€Å"Who would ever think of learning to live out of an English novel?† an irritated Caroline Spalding asks her zealously romantic sister, a credulous devotee of the genre. We might turn her question on its head and ask how it is that people learn how to live in an English novel, and what He Knew He Was Right in particular has to say about becoming good. If the novel’s most prominent interest is in the breakdown or perversion of moral certainty, exemplified in the grotesque errors of judgment that deprive Trevelyan of his family and his sanity, it also manifests a subsidiary interest in the ways in which moral agents can replace such false certainty with the sort of just and balanced ethical vision that Trevelyan so conspicuously lacks. As we will see, this concern with moral education is displayed most directly in the novel’s secondary narrative threads, in which both Jemima Stanbury and her niece Dorothy attain an empathetic subtlety of perception and a depth of understanding of others that are absent in their former selves, as depicted at the opening of the novel.

Determination of the molar mass of magnesium Essay

Introduction: This experiment will be an attempt to determine the molar mass of magnesium. For that we will have an experiment where we dissolve sulphur into hydrochloric acid. Then we measure the amount of gas created during the reaction. To get the molar mass itself we will have to make sure to record the conditions of the experiment such as the temperature or pressure. Material: The material used for the experiment was: 1. eudiometer 2. thermometer 3. barometer 4. measuring cylinder (1000 cm3) 5. Stand with clamp 6. magnesium ribbon 7. hydrochloric acid Method: 1. About 20mm of magnesium ribbon and weight it with the accuracy of 0.001g 2. Pour 5cm3 of HCl into the eudiometer. Then carefully filling the eudiometer with water above the HCl, without mixing the liquids. 3. Wind the magnesium ribbon around a piece of copper wire and let it hang down a little bit into the eudiometer. Make sure there is a hole into the rubber stopper and fill it with water. 4. Place a large measuring cylinder filled with water in the sink. Put a finger over the hole in the stopper and turn the eudiometer upside down into the cylinder. 5. Observe what happens with the hydrochloric acid and magnesium after a little while. When the reaction is complete wait at least 5 minutes so that the eudiometer reaches room temperature. 6. Arrange the eudiometer in the cylinder so that the gas into the eudiometer has the same pressure as the air pressure in the room. Note the air pressure and temperature in the room. 7. Calculate the molar mass of magnesium. Result: Before the experiment the magnesium was carefully weighted on a scale. After turning the eudiometer the HCl started to go down towards the magnesium through the water. Once it reached it a reaction took place creating bubbles of air that went up to the top and pushed the water level down. Once the reaction ended all the magnesium was gone. During the reaction the temperature was read of a thermometer and the pressure of a barometer to get the most accurate values. finally we measured the volume of air inside the eudiometer. Conclusion and Evaluation: When studding the results and comparing them with the book (24.31 ) one can see that the value received from the experiment () is very comparable. Percentage yield: Despite that high percentage the experiment was not accurate enough to have the book value within the error range (≈). The biggest two sources of error in this experiment are the instruments (systematic errors) and of course the human factor (random errors). Also the part of the experiment where one is supposed to turn the eudiometer and put it into water can impossibly be done without bigger or lesser errors since it’s such a complex movement. Then I would like to put extra attention on the thermometer and especially the barometer. The thermometer could only show whole degrees which is a great loss to precision. Then the barometer seemed quite old and unstable and the need to convert the pressure to Pascal and finally reading from it was quite hard which in my opinion was altogether quite hard. Also these where only the conditions in the entire room. One cannot be sure if they where exactly the same in the tube. Especially the temperature of water could have been quite different. Then of course the amount mg could have impossibly been measured accurately and we can’t be sure if exactly all of it reacted. Also the unknown pureness of the reactants and the solvent could justify the error in the result. My suggestions for improvements is to begin with is use of more precise instruments. Then a different method involving a more closed environment and a different method for gathering data. Bibliography: 1. â€Å"Standard Level Chemistry† Pearson Baccalaureate by Catrin Brown and Mike Ford

Digital Cinema

Scott McQuire Millennial fantasies As anyone interested in film culture knows, the last decade has witnessed an explosion of pronouncements concerning the future of cinema. Many are fuelled by naked technological determinism, resulting in apocalyptic scenarios in which cinema either undergoes digital rebirth to emerge more powerful than ever in the new millennium, or is marginalised by a range of ‘new media’ which inevitably include some kind of broadband digital pipe capable of delivering full screen ‘cinema quality’ pictures on demand to home consumers.The fact that the doubleedged possibility of digital renaissance or death by bytes has coincided with celebrations of the ‘centenary of cinema’ has undoubtedly accentuated desire to reflect more broadly on the history of cinema as a social and cultural institution. It has also intersected with a significant transformation of film history, in which the centrality of ‘narrative’ as th e primary category for uniting accounts of the technological, the economic and the aesthetic in film theory, has become subject to new questions.Writing in 1986 Thomas Elsaesser joined the revisionist project concerning ‘early cinema’ to cinema’s potential demise: ‘A new interest in its beginnings is justified by the very fact that we might be witnessing the end: movies on the big screen could soon be the exception rather than the rule’. 1 Of course, Elsaesser’s speculation, which was largely driven by the deregulation of television broadcasting in Europe in conjunction with the emergence of new technologies such as video, cable and satellite in the 1980s, has been contradicted by the decade long cinema boom in the multiplexed 1990s. It has also been challenged from another direction, as the giant screen ‘experience’ of large format cinema has been rather unexpectedly transformed from a bit player into a prospective force. However , in the same article, Elsaesser raised another issue which has continued to resonate in subsequent debates: Scott McQuire, ‘Impact Aesthetics: Back to the Future in Digital Cinema? ‘, Convergence: The Journal of Research into New Media Technologies, vol. 6, no. 2, 2000, pp. 41-61.  © Scott McQuire. All rights reserved.Deposited to the University of Melbourne ePrints Repository with permission of Sage Publications . 2 Few histories fully address the question of why narrative became the driving force of cinema and whether this may itself be subject to change. Today the success, of SF as a genre, or of directors like Steven Spielberg whose narratives are simply anthology pieces from basic movie plots, suggest that narrative has to some extent been an excuse for the pyrotechnics of IL;M. 3 Concern for the demise, if not of cinema per se, then of narrative in cinema, is widespread in the present.In the recent special ‘digital technology’ issue of Screen, Sean Cubitt noted a ‘common intuition among reviewers, critics and scholars that something has changed in the nature of cinema — something to do with the decay of familiar narrative and performance values in favour of the qualities of the blockbuster’. 4 Lev Manovich has aligned the predominance of ‘blockbusters’ with ‘digital cinema’ by defining the latter almost entirely in terms of increased visual special effects: ‘A visible sign of this shift is the new role which computer generated special effects have come to play in the Hollywood industry in the last few years.Many recent blockbusters have been driven by special effects; feeding on their popularity’. 5 In his analysis of Hollywood’s often anxious depiction of cyberspace in films such as The Lawn Mower Man (1992), Paul Young argues that ‘cyberphobic films overstress the power of the visual in their reliance on digital technology to produce spectacle at the exp ense of narrative’, and adds this is ‘a consequence that [Scott] Bukatman has argued is latent in all special effects’. A more extreme (but nevertheless common) view is expressed by film maker Jean Douchet: ‘[Today] cinema has given up the purpose and the thinking behind individual shots [and narrative], in favour of images — rootless, textureless images — designed to violently impress by constantly inflating their spectacular qualities’. 7 ‘Spectacle’, it seems, is winning the war against ‘narrative’ all along the line.Even a brief statistical analysis reveals that ‘special effects’ driven films have enjoyed enormous recent success, garnering an average of over 60% of the global revenue taken by the top 10 films from 1995-1998, compared to an average of 30% over the previous four years. 8 Given that the proportion of box office revenue taken by the top 10 films has held steady or increased slightl y in the context of a rapidly expanding total market, this indicates that a handful of special-effects films are generating huge revenues each year.While such figures don’t offer a total picture of the film industry, let alone reveal which films which will exert lasting cultural influence, they do offer a snapshot of contemporary cultural taste refracted through studio marketing budgets. Coupled to the recent popularity of paracinematic forms, such as large format and special venue films, the renewed emphasis on ‘spectacle’ over ‘narrative’ suggests another possible end-game for 3 inema: not the frequently prophesied emptying of theatres made redundant by the explosion of home-based viewing (television, video, the internet), but a transformation from within which produces a cinema no longer resembling its (narrative) self, but something quite other. Complementing these debates over possible cinematic futures is the fact that any turn to spectacular f ilm ‘rides’ can also be conceived as a return — whether renaissance or regression is less clear — to an earlier paradigm of film-making famously dubbed the ‘cinema of attraction’ by Tom Gunning.Gunning long ago signalled this sense of return when he commented: ‘Clearly in some sense recent spectacle cinema has re-affirmed its roots in stimulus and carnival rides, in what might be called the Spielberg-Lucas-Coppola cinema of effects’. 9 For Paul Arthur, developments in the 1990s underline the point: The advent of Imax 3-D and its future prospects, in tandem with the broader strains of a New Sensationalism, provide an occasion to draw some connections with the early history of cinema and the recurrent dialectic between the primacy of the visual and, for lack of a better term, the sensory. 0 In what follows here, I want to further consider the loops and twists of these debates, not so much with the grand ambition of resolving them, b ut firstly of adding some different voices to the discussion — particularly the voices of those involved in film production. 11 My intention is not to elevate empiricism over theory, but to promote dialogue between different domains of film culture which meet all too rarely, and, in the process, to question the rather narrow terms in which ‘digital cinema’ has frequently entered recent theoretical debates.Secondly, I want to consider the relation between ‘narrative’ and ‘spectacle’ as it is manifested in these debates. My concern is that there seems to be a danger of confusing a number of different trajectories — such as cinema’s on-going efforts to demarcate its ‘experience’ from that of domestic entertainment technologies, and the turn to blockbuster exploitation strategies —and conflating them under the heading of ‘digital cinema’.While digital technology certainly intersects with, and si gnificantly overlaps these developments, it is by no means co-extensive with them. ‘Spectacular sounds’: cinema in the digital domain Putting aside the inevitable hype about the metamorphosis of Hollywood into ‘Cyberwood’, like many others I am convinced that digital technology constitutes a profound revolution in cinema, primarily because of its capacity to cut across all 4 sectors of the industry simultaneously, affecting film production, narrative conventions and audience experience.In this respect, the only adequate point of reference for the depth and extent of current changes are the transformations which took place with the introduction of synchronised sound in the 1920s. However, while the fundamental level at which change is occurring is widely recognised, it has been discussed primarily in terms of the impact of CGI (computer-generated imaging) on the film image. A more production-oriented approach would most likely begin elsewhere; with what Phil ip Brophy has argued is among ‘the most overlooked aspects of film theory and criticism (both modern and postmodern strands)’ — sound. 2 A brief flick through recent articles on digital cinema confirms this neglect: Manovich locates ‘digital cinema’ solely in a historical lineage of moving pictures; none of the articles in the recent Screen dossier mention sound, and even Eric Faden’s ‘Assimilating New Technologies: Early Cinema, Sound and Computer Imaging’ only uses the introduction of synchronised sound as an historical analogy for discussing the contemporary effect of CGI on the film image13. While not entirely unexpected, this silence is still somewhat urprising, given the fact that digital sound technology was adopted by the film industry far earlier and more comprehensively than was CGI. And, at least until the early 1990s with films like Terminator 2 (1991) and Jurassic Park (1993), the effect on audience experience was arg uably far greater than was digital imaging. Dominic Case [Group Services and Technology Manager at leading Australian film processor Atlab] argued in 1997: I am more and more convinced that the big story about film technology as far as audiences are concerned in the past few years has been sound.Because, although you can do fancy digital things, the image remains glued to that bit of screen in front of your eyes, and it’s not really any bigger†¦ But the sound has gone from one woolly sound coming from the back of the screen with virtually no frequency range or dynamic range whatsoever †¦ to something that fills the theatre in every direction with infinitely more dynamic range and frequency range. To me, that’s an explosion in experience compared to what you are seeing on the screen.However, the visual bias of most film theory is so pervasive that this transformation often passes unremarked. Part of the problem is that we lack the necessary conceptual armature : there are no linkages which pull terms such as 5 ‘aural’ or ‘listener’ into the sort of semantic chain joining spectacle and spectator to the adjective ‘spectacular’. Film sound-mixer Ian McLoughlin notes: Generally speaking, most people are visually trained from birth. †¦ Very few people are trained to have a aural language and, as a result there isn't much discussion about the philosophy of the sound track. .. There has been very, very little research done into the psycho-acoustic effects of sound and the way sound works sociologically on the audience. 14 Compounding this absence is the fact that the digital revolution in sound is, in many respects, the practical realisation of changes initiated with the introduction of Dolby Stereo in 1975. (On the other hand, the fact that CGI entered a special effects terrain already substantially altered by techniques of motion control, robotics and animatronics didn’t prevent critical atten tion to it. Four-track Dolby stereo led to a new era of sound experimentation beginning with films such as Star Wars (1977) and Close Encounters of the Third Kind (1977). As renowned sound mixer Roger Savage (whose credits include Return of the Jedi, 1983; Shine, 1996; and Romeo + Juliet, 1996) recalls: ‘Prior to that, film sound hadn’t changed for probably 30 years. It was Mono Academy †¦ Star Wars was one of the first films that I can remember where people started coming out of the theatre talking about the sound track’. 5 While narrative sound effects such as dialogue and music were still generally concentrated in the front speakers, the surround sound speakers became the vehicles for a new range of ‘spectacular’ sound effects. In particular, greater emphasis was given to boosting low frequency response, explicitly mirroring the amplified ambience of rock music. There was also greater attention given to the ‘spatialisation’ of di screte sound elements within the theatre.As Rich Altman has argued, these developments presented a significant challenge to one of the fundamental precepts of classical Hollywood narrative: the unity of sound and image and the subservience of sound effects to narrative logic: Whereas Thirties film practice fostered unconscious visual and psychological spectator identification with characters who appear as a perfect amalgam of image and sound, the Eighties ushered in a new kind of visceral identification, dependent on the sound system’s overt ability, through bone-rattling bass and unexpected surround effects, to cause spectators to vibrate — quite literally — with the entire narrative space.It is thus no longer the eyes, the ears and the brain that alone initiate identification and maintain contact with a sonic 6 source; instead, it is the whole body that establishes a relationship, marching to the beat of a different woofer. Where sound was once hidden behind t he image in order to allow more complete identification with the image, now the sound source is flaunted, fostering a separate sonic identification contesting the limited rational draw of the image and its characters. 16 Altman’s observation is significant in this context, inasmuch as it suggests that the dethroning of a certain model of narrative cinema had begun prior to the digital threshold, and well before the widespread use of CGI.It also indicates the frontline role that sound took in the film industry’s initial response to the incursions of video : in the 1980s the new sound of cinema was a primary point of differentiation from domestic image technologies. However, while Dolby certainly created a new potential for dramatic sound effects, in practice most film makers remained limited by a combination of logistical and economic constraints. In this respect, the transition to digital sound has been critical in creating greater latitude for experimentation within e xisting budget parameters and production time frames. In terms of sound production, Roger Savage argues: ‘The main advantages in digital are the quality control, the speed and the flexibility’. This is a theme which is repeated with regard to the computerisation of other areas of film making such as picture editing and CGI. ) Enhanced speed, flexibility and control stem from a reduction in the need for physical handling and a refinement of precision in locating and manipulating individual elements. In sound production, libraries of analogue tape reels each holding ten minutes of sound have given way to far more compact DAT tapes and hard drive storage. The entire production process can now often be realised on a single digital workstation. There is no need for a separate transfer bay, and, since digital processing involves the manipulation of electronic data, there is no risk of degrading or destroying original recordings by repeated processing.Once the sounds are catal ogued, digital workstations grant random access in a fraction of a second (eliminating tape winding time), and, unlike sprocket-based sound editing, all the tracks which have been laid can be heard immediately in playback. The creative pay-off is an enhanced ability to add complexity and texture to soundtracks. In terms of sound reproduction, the most marked change resulting from six track digital theatre systems is improved stereo separation and frequency response which assists better music reproduction in theatres — a change which goes hand in glove with the increased prominence that music and soundtracks have assumed in promoting and marketing films in recent years. 7The enhanced role of sound in cinema is even more marked for large format films which, because of their high level of visual detail, demand a correspondingly high level of audio detail. Ian McLoughlin (who, amongst many other things, shares sound mixing credits with Savage for the large-format films Africaâ₠¬â„¢s Elephant Kingdom, 1998 and The Story of a Sydney, 1999) comments: If you look at the two extremes of image technology, if you look at television, and then you look at something like Imax, the most interesting difference is the density of the sound track that is required with the size of the picture. When you’re doing a TV mix, you try to be simple, bold. You can’t get much in or otherwise it just becomes a mess.With 35mm feature films you're putting in 10, 20 times more density and depth into the sound track as compared to television, and †¦ when you go to Imax, you need even more. McLoughlin also makes a significant point concerning the use (or abuse) of digital sound: When digital first came out and people found that they could make a enormously loud sound tracks, everyone wanted enormously large sound tracks. †¦ Unfortunately some people who present films decided that the alignment techniques that companies like Dolby and THX have worked out arenâ₠¬â„¢t to their liking and they think audiences like a lot of sub-base and so they sometimes wind that up. †¦ [S]uddenly you’ve got audiences with chest cavities being punched due to the amount of bottom end. †¦Dolby and screen producers and screen distributors in America have actually been doing a lot of research into what they are calling the ‘annoyance factor’ of loud sound tracks. Because audiences are getting turned off by overly jarring, overly sharp, soundtracks. This comment is worth keeping in mind for two reasons. Firstly, it underlines the fact that the image is by no means the only vehicle for producing cinematic affect: in this sense, ‘impact aesthetics’ offers a more apt description of the trajectory of contemporary cinema than ‘spectacle’. Secondly, it warns against making hasty generalisations when assessing the long-term implications of CGI.While digital imaging undoubtedly represents a significant paradigm shif t in cinema, it is also feasible that the 1990s will eventually be seen more as a teething period of ‘gee whizz’ experimentation with the new digital toolbox, which was gradually turned towards other (even more ‘narrative’) ends. (The way we now look at early sound films is instructive: while contemporary audiences were fascinated by the mere 8 fact that pictures could ‘talk’, in retrospect we tend to give more weight to the way sound imposed new restrictions on camera movement, location shooting and acting style). Painting with light In contrast to the relative dearth of attention given to changes in areas such as sound and picture editing, digital manipulation of the film image has received massive publicity.While this is partly the result of deliberate studio promotion, it also reflects the profound changes in cinematic experience that computers have set in train. When we can see Sam Neil running from a herd of dinosaurs — in other wo rds, when we see cinematic images offering realistic depictions of things we know don’t exist — it is evident that the whole notion of photo-realism which has long been a central plank of cinematic credibility is changing. But how should this change be understood? Is it simply that ‘live action’ footage can now be ‘supplemented’ with CG elements which replace earlier illusionistic techniques such as optical printing, but leave cinema’s unique identity as an ‘art of recording’ intact? Or is a new paradigm emerging in which cinema becomes more like painting or animation?Lev Manovich has recently taken the latter position to an extreme, arguing that, ‘Digital cinema is a particular case of animation which uses live-action footage as one of its many elements’, and concluding: ‘In retrospect, we can see that twentieth century cinema’s regime of visual realism, the result of automatically recording visua l reality, was only an exception, an isolated accident in the history of visual representation†¦ ’. 17 While I suspect that Manovich significantly underestimates the peculiar attractions of ‘automatic recording’ (which produced what Walter Benjamin termed the photograph’s irreducible ‘spark of contingency’, what Barthes ontologised as the hotographic punctum), it is clear the referential bond linking camera image to physical object has come under potentially terminal pressure in the digital era. However, any consideration of ‘realism’ in cinema is immediately complicated by the primacy of fictional narrative as the dominant form of film production and consumption. Moreover, cinema swiftly moved from adherence to the ideal of direct correspondence between image and object which lay at the heart of classical claims to photographic referentiality. ‘Cheating’ with the order of events, or the times, locations and sett ings in which they occur, is second nature to film-makers. By the time cinema ‘came of age’ in the picture palace of the 1920s, a new logic of montage, shot matching and continuity had coalesced into the paradigm of 9 classical narrative’, and cinematic credibility belonged more to the movement of the text rather than the photographic moment — a shift Jean-Louis Commolli has neatly described in terms of a journey from purely optical to psychological realism. 18 Within this paradigm all imaginable tactics were permissible in order to imbue pro-filmic action with the stamp of cinematic authority — theatrical techniques such as performance, make-up, costumes, lighting and set design were augmented by specifically cinematic techniques such as stop motion photography and rear projection, as well as model-making and matte painting which entered the screen world via the optical printer.Given this long history of simulation, the digital threshold is perhaps best located in terms of its effect on what Stephen Prince has dubbed ‘perceptual realism’, rather than in relation to an abstract category of ‘realism’ in general. Prince argues: A perceptually realistic image is one which structurally corresponds to the viewer’s audio-visual experience of three-dimensional space †¦ Such images display a nested hierarchy of cues which organise the display of light, colour, texture, movement and sound in ways that correspond to the viewer’s own understanding of these phenomena in daily life. Perceptual realism, therefore, designates a relationship between the image on film and the spectator, and it can encompass both unreal images and those which are referentially realistic. Because of this, unreal images may be referentially fictional but perceptually realistic. 19I have emphasised Prince’s evocation of fidelity to ‘audio-visual experience’ because it underlines the extent to which t he aim of most computer artists working in contemporary cinema is not simply to create high resolution images, but to make these images look as if they might have been filmed. This includes adding various ‘defects’, such as film grain, lens flare, motion blur and edge halation. CG effects guru Scott Billups argues that film makers had to ‘educate’ computer programmers to achieve this end: For years we were saying: ‘Guys, you look out on the horizon and things get grayer and less crisp as they get farther away’. But those were the types of naturally occurring event structures that never got written into computer programs.They’d say ‘Why do you want to reduce the resolution? Why do you want to blur it? ’. 20 10 By the 1990s many software programs had addressed this issue. As Peter Webb (one of the developers of Flame) notes: Flame has a lot of tools that introduce the flaws that one is trained to see. Even though we donâ€℠¢t notice them, there is lens flare and motion blur, and the depth of field things, and, if you don’t see them, you begin to get suspicious about a shot. 21 In other words, because of the extent to which audiences have internalised the camera’s qualities as the hallmark of credibility, contemporary cinema no longer aims to mime ‘reality’, but ‘camera-reality’.Recognising this shift underlines the heightened ambivalence of realism in the digital domain. The film maker’s ability to take the image apart at ever more minute levels is counterpointed by the spectator’s desire to comprehend the resulting image as ‘realistic’ — or, at least, equivalent to other cine-images. In some respects, this can be compared to the dialectic underlying the development of montage earlier this century, as a more ‘abstract’ relation to individual shots became the basis for their reconstitution as an ‘organicâ€℠¢ text. But instead of the fragmentation and re-assemblage of the image track over time, which founded the development of lassical narrative cinema and its core ‘grammatical’ structures such as shot/reverse shot editing, digital technology introduces a new type of montage: montage within the frame whose prototype is the real time mutation of morphing. However, while ‘perceptual realism’ was achieved relatively painlessly in digital sound, the digital image proved far more laborious. Even limited attempts to marry live action with CGI, such as TRON (1982) and The Last Starfighter (1984) proved unable to sustain the first wave of enthusiasm for the computer. As one analyst observed: ‘The problem was that digital technology was both comparatively slow and prohibitively expensive. In fact, workstations capable of performing at film resolution were driven by Cray super-computers’. 2 It is these practical exigencies, coupled to the aesthetic disjunct ion separating software programmers from film makers I noted above, rather than a deeply felt desire to manufacture a specifically electronic aesthetic, which seems to underlie the ‘look’ of early CGI. 23 Exponential increases in computing speed, coupled to decreases in computing cost, not only launched the desktop PC revolution in the mid-1980s, but made CGI in film an entirely different matter. The second wave of CGI was signalled when Terminator 2: Judgement Day (1991) made morphing a household word. 24 Two 11 years later the runaway box-office success of Jurassic Park (1993) changed the question from whether computers could be effectively used in film making to how soon this would happen. The subsequent rash of CGI-driven blockbusters, topped by the billion dollar plus gross of Cameron’s Titanic (1997), has confirmed the trajectory.Cameron is one of many influential players who argue that cinema is currently undergoing a fundamental transformation: ‘Weà ¢â‚¬â„¢re on the threshold of a moment in cinematic history that is unparalleled. Anything you imagine can be done. If you can draw it, if you can describe it, we can do it. It’s just a matter of cost’. 25 While this claim is true at one level — many tricky tasks such as depicting skin, hair and water, or integrating CGI elements into live action images shot with a hand-held camera, have now been accomplished successfully — it is worth remembering that ‘realism’ is a notoriously slippery goal, whether achieved via crayon, camera or computer.Dennis Muren’s comments on his path-breaking effects for Jurassic Park (which in fact had only 5 to 6 minutes of CGI and relied heavily on models and miniatures, as did more recent ‘state of the art’ blockbusters such as The Fifth Element, 1997 and Dark City, 1998) bear repeating: ‘Maybe we’ll look back in 10 years and notice that we left things out that we didn’t kn ow needed to be there until we developed the next version of this technology’. Muren adds: In the Star Wars films you saw lots of X-wings fighters blow up, but these were always little models shot with high-speed cameras. You’ve never seen a real X-wing blow up, but by using CGI, you might just suddenly see what looks like a full-sized X-wing explode. It would be all fake of course, but you’d see the structure inside tearing apart, the physics of this piece blowing off that piece. Then you might look back at Star Wars and say, ‘That looks terrible’. 26Clearly, George Lucas shared this sentiment, acknowledging in 1997 that ‘I’m still bugged by things I couldn’t do or couldn’t get right, and now I can fix them’. 27 The massive returns generated by the ‘digitally enhanced’ Star Wars trilogy raises the prospect of a future in which blockbuster movies are not re-made with new casts, but perpetually updated w ith new generations of special effects. Stop the sun, I want to get off Putting aside the still looming question of digital projection, the bottom line in the contemporary use of digital technology in cinema is undoubtedly ‘control’: 12 particularly the increased control that film makers have over all the different components of image and sound tracks.Depending on a film’s budget, the story no longer has to work around scenes which might be hard to set up physically or reproduce photo-optically— they are all grist to the legions of screen jockeys working in digital post-production houses. George Lucas extols the new technology for enhancing the ability to realise directorial vision: I think cinematographers would love to have ultimate control over the lighting; they’d like to be able to say, ‘OK, I want the sun to stop there on the horizon and stay there for about six hours, and I want all of those clouds to go away. Everybody wants that kind of control over the image and the storytelling process. Digital technology is just the ultimate version of that. 28A direct result of digital imaging and compositing techniques has been an explosion of films which, instead of ‘fudging’ the impossible, revel in the capacity to depict it with gripping ‘realism’: Tom Cruise’s face can be ripped apart in real time (Interview with the Vampire, 1994), the Whitehouse can be incinerated by a fireball from above (Independence Day, 1996), New York can be drowned by a tidal wave, or smashed by a giant lizard(Deep Impact, Godzilla, 1998). But, despite Lucas’ enthusiasm, many are dubious about where the new primacy of special effects leaves narrative in cinema. The argument put forward by those such as Sean Cubitt and Scott Bukatman is that contemporary special effects tend to displace narrative insofar as they introduce a disjunctive temporality evocative of the sublime.Focusing on Doug Trumbull’s work, Bukatman emphasises the contemplative relationship established between spectator and screen in key effects scenes (a relationship frequently mirrored by on-screen characters displaying their awe at what they– and ‘we’ – are seeing. )29 Cubitt suggests that similar ‘fetishistic’ moments occur in songs such as Diamonds are a Girl’s Best Friend, where narrative progress gives way to visual fascination. His example is drawn from a strikingly similar terrain to that which inspired Laura Mulvey’s well-known thesis on the tension between voyeurism and scopophilia in classical narrative cinema: Mainstream film neatly combined spectacle and narrative. (Note, however, in the musical song-and-dance numbers break the flow of the diegesis).The presence of woman is an indispensable element of spectacle in normal narrative film, yet her visual presence tends to work against the development of a story line, to freeze the flow of action in moments of erotic contemplation. 30 13 This connection was also made by Tom Gunning in his work on the early ‘cinema of attraction’: ‘As Laura Mulvey has shown in a very different context, the dialectic between spectacle and narrative has fueled much of the classical cinema’. 31 In this respect, a key point to draw from both Mulvey and Gunning is to recognise that they don’t conceive the relationship between spectacle and narrative in terms of opposition but dialectical tension. 32 This is something that other writers have sometimes forgotten.Presenting the issue in terms of an opposition (spectacle versus narrative) in fact recycles positions which have been consistently articulated (and regularly reversed) throughout the century. In the 1920s, avant-garde film makers railed against ‘narrative’ because it was associated primarily with literary and theatrical scenarios at the expense of cinematic qualities (Gunning begins his ‘Cine ma of Attraction’ essay with just such a quote from Fernand Leger). Similar concerns emerged with debates in France over auteur theory in the 1950s, where the literary qualities of script were opposed to the ‘properly cinematic’ qualities of mise-en-scene.In the 1970s, the ‘refusal of narrative’ which characterised much Screen theory of the period, took on radical political connotations. Perhaps as a reaction to the extremity of pronouncements by those such as Peter Gidal, there has been a widespread restoration of narrative qualities as a filmic ‘good object’ in the present. However, rather than attempting to resolve this split in favour of one side or the other, the more salient need is to examine their irreducible intertwining: what sort of stories are being told, and what sort of spectacles are being deployed in their telling? While it is easy to lament the quality of story-telling in contemporary blockbusters, few critics seriously maintain that such films are without narrative.A more productive framework is to analyse why explicitly ‘mythological’ films such as the Star Wars cycle have been able to grip popular imagination at this particular historical conjuncture, marrying the bare bones of fairy-tale narrative structures to the inculcation of a specific type of special effects driven viewing experience. (To some extent, ths is Bukatman’s approach in his analysis of special effects). In this context, it is also worth remembering that, despite the quite profound transformations set in train by the use of digital technology in film making, there has thus far been little discernible effect on narrative in terms of structure or genre. The flirtation with ‘non-linear’ and ‘interactive’ films was a shooting star which came and went with the CD-ROM, while most contemporary blockbusters conform smoothly to established cine-genres (sci-fi, horror, disaster and action- 14 dventure predominating), with a significant number being direct re-makes of older films done ‘better’ in the digital domain. One of the more interesting observations about possible trends in the industry is put forward by James Cameron, who has argued that digital technology has the potential to free film makers from the constraints of the ‘A’ and ‘B’ picture hierarchy: [I]n the ’40s you either had a movie star or you had a B-movie. Now you can create an A-level movie with some kind of visual spectacle, where you cast good actors, but you don’t need an Arnold or a Sly or a Bruce or a Kevin to make it a viable film. 33 However, Cameron himself throws doubt on the extent of this ‘liberation’ by underlining the industrial nature of digital film production. 4 In practice, any film with the budget to produce a large number of cutting edge special effects shots is inevitably sold around star participation, as well as specta cle (as were films such as The Robe, 1953 and Ben Hur, 1926). This point about the intertwining of narrative and spectacle is re-inforced if we look at developments in large-format film, an area frequently singled out for its over-dependence on screen spectacle to compensate for notoriously boring ‘educational’ narrative formats. Large-format (LF) cinema is currently in the throes of a significant transformation The number of screens worldwide has exploded in the last four years (between 1995 and January 1999, the global LF circuit grew from 165 to 263 theatres. By January 2001, another 101 theatres are due to open, taking the total to 364, an increase of 120% in 6 years).More significantly, the majority of new screens are being run by commercial operators rather than institutions such as science museums. These new exhibition opportunities, coupled to the box-office returns generated by films such as Everest (the 15th highest grossing film in the USA in 1998, despite ap pearing on only 32 screens) has created significant momentum in the sector for the production of LF films capable of attracting broader audiences. For some producers, this means attempting to transfer the narrative devices of dramatic feature films onto the giant screen, while others argue that the peculiarities of the medium means that LF needs to stick with its proven documentary subjects.However, most significantly in this context, none dispute the need for the sector to develop better narrative techniques if it is to grow and prosper, particularly by 15 attracting ‘repeat’ audiences. In many respects, the LF sector is currently in a similar position to cinema in the 1900s, with people going to see the apparatus rather than a specific film, and the ‘experience’ being advertised largely on this basis. While it would be simplistic to see current attempts to improve the narrative credentials of LF films as a faithful repetition of the path that 35mm cinema took earlier this century, since most production is likely to remain documentary-oriented, it would be equally as foolish to ignore the cultural and commercial imperatives which still converge around telling a ‘good story’. 5 Distraction and the politics of spectacle Despite the current rash of digitally-inspired predictions, narrative in film is unlikely to succumb to technological obsolescence. But nor will spectacle be vanquished by a miraculous resurgence of ‘quality’ stories. A corollary of a dialectical conception of the interrelationship between narrative and spectacle is that neither should be seen simply as ‘good’ or ‘bad’ objects in themselves. For Mulvey, spectacle (exemplified by close-ups which turn woman’s face and body into a fetish), as well as the more voyeuristic strategy of narrative, were both attuned to the anxious imagination of patriarchal culture in classical cinema.Both were techniques for negotiatin g the threat of castration raised by the image of woman, an image classical cinema simultaneously desired and sought to circumscribe or punish. Nevertheless, even within this heavily constrained context, ‘spectacle’ could also assume a radical function by ‘interrupting’ the smooth functioning of narrative, disturbing the rules of identification and the systematic organisation of the look within the text. (This is the gist of her comparison between the films of von Sternberg, which privilege a fetish image of Dietrich over narrative progress, and those of Hitchcock which more closely align the viewer with the male protagonist). Can spectacle still exert a ‘progressive’ function in contemporary cinema?While most critics answer this question negatively without even posing it, Paul Young is unusual in granting a measure of radical effect to the renewed primacy of spectacle. Young draws on Miriam Hansen’s account of the ‘productive ambi guity’ of early cinema, in which the lack of standardised modes of exhibition, coupled to reliance on individual attractions, gave audiences a relative freedom to interpret what they saw, and established cinema as (potentially) an alternative public sphere. He takes this as support for his argument that contemporary ‘spectacle’ cinema constitutes an emergent challenge to ‘Hollywood’s institutional identity’. 36 16 Young’s analysis contrasts markedly with Gunning’s earlier description of the ‘cinema of effects’ as ‘tamed attractions’. 7 Nevertheless both share some common ground: Young’s reference to the ‘productive ambiguity’ of early cinema, like Gunning’s rather oblique and undeveloped reference to the ‘primal power’ of attraction, draws nourishment from Siegfried Kracauer’s early writings on the concept of distraction. In the 1920s, Kracauer set up Ã¢â‚¬Ë œdistraction’ as a counterpoint to contemplation as a privileged mode of audience reception, seeing it as embodying a challenge to bourgeois taste for literary-theatrical narrative forms, and also as the most compelling mode of presentation to the cinema audience of their own disjointed and fragmented conditions of existence. 38 While distraction persisted as a category used by Walter Benjamin in his ‘Artwork’ essay of the mid1930s, by the 1940s Kracauer seemed to have revised his position.As Elsaesser has pointed out, this re-appraisal was at least partly a re-assessment of the ‘productive ambiguity’ which had characterised social spaces such as cinema; by the 1940s distraction and spectacle had been consolidated into socially dominant forms epitomised by Hollywood on the one hand and fascism on the other. 39 If Kracauer’s faith that the 1920s audience could symptomatically encounter ‘its own reality’ via the superficial glamour of movie stars rather than the putative substance of the era’s ‘high culture’ was already shaken by the 1940s, what would he make of the post-pop art, postmodern 1990s? The extent to which surface elements of popular culture have been esthetically ‘legitimated’ without any significant transformation of corresponding political and economic values suggests the enormous difficulties facing those trying to utilise spectacle as a ‘progressive’ element in contemporary culture. However, it is equally important to acknowledge that this problem cannot be resolved simply by appealing to ‘narrative’ as an antidote. While the terms remain so monolithic, the debate will not progress beyond generalities. In this respect, Kracauer’s work still offers some important lessons to consider in the present. Here, by way of conclusion, I want to sketch out a few possible lines of inquiry. On the one hand, his concept of the ‘mass orna ment’ indicates that any turn, or return, to spectacle in cinema needs to be situated in a wider social context. 0 Spectacle is not simply a matter of screen image, but constitutes a social relation indexed by the screen (something Guy Debord underlined in the 1960s). Developments in contemporary cinema need to be related to a number of other trajectories, including cinema’s on-going endeavours to distinguish its ‘experience’ 17 from that of home entertainment, as well as the proliferation of spectacle in social arenas as diverse as sport (the Olympic games), politics (the dominance of the cult of personality in all political systems) and war (the proto-typical ‘media-event’). On the other hand, the specific forms of spectacle mobilised in contemporary cinema need to be examined for the extent to which they might reveal (in Kracauer’s terms) the ‘underlying meaning of existing conditions’.Kracauer’s analysis of cinem a in the 1920s situated the popularity of a certain structure of viewing experience in relation to the rise of a new class (the white collar worker). In contemporary terms, I would argue that the relevant transformation is the process of ‘globalisation’. While this is a complex, heterogeneous and uneven phenomenon, a relevant aspect to consider here is Hollywood’s increasing reliance on overseas markets, both for revenue, and, more importantly, for growth. 41 In this context, the growing imperative for films to ‘translate’ easily to all corners and cultures of the world is answered by building films around spectacular action setpieces. Equally as ignificantly, the predominant themes of recent special effects cinema— the destruction of the city and the mutation or dismemberment of the human body — are symptomatic of the underlying tensions of globalisation, tensions exemplified by widespread ambivalence towards the socio-political effect s of speed and the new spatio-temporal matrices such as cyberspace. 42 The most important cinematic manifestations of these anxious fascinations are not realised at the level of narrative ‘content’ (although they occasionally make themselves felt there), but appear symptomatically in the structure of contemporary viewing experience. The repetition of awe and astonishment repeatedly evoked by ‘impossible’ images as the currency of today’s ‘cutting edge’ cinema undoubtedly functions to prepare us for the uncertain pleasures of living in a world we suspect we will soon no longer recognise: it is not simply ‘realism’ but ‘reality’ which is mutating in the era of digital economy and the Human Genome Project.If this turn to spectacle is, in some respects, comparable to the role played by early cinema in negotiating the new social spaces which emerged in the industrial city remade by factories and department stores, el ectrification and dynamic vehicles, it also underscores the fact that the ‘death’ of camera realism in the late twentieth century is a complex psycho-social process, not least because photo-realism was always less an aesthetic function than a deeply embedded social and political relation. 43 18 Finally, I would argue that it is important not to subsume all these filmic headings under the single rubric of ‘digital’. There is a need to acknowledge, firstly, that digital technology is used far more widely in the film industry than for the production of blockbusters and special effects (for example, it is the new industry standard in areas such as sound production and picture editing).Moreover, as Elsaesser has argued recently, technology is not the driving force: ‘In each case, digitisation is ‘somewhere’, but it is not what regulates the system, whose logic is commercial, entrepreneurial and capitalist-industrialist’44 What the digit al threshold has enabled is the realignment of cinema in conformity with new demands, such as ‘blockbuster’ marketing blitzes constructed around a few spectacular image sequences of the kind that propelled Independence Day to an US$800m gross. It has rejuvenated cinema’s capacity to set aesthetic agendas, and, at the same time, restored its status as a key player in contemporary political economy. In this context, one aspect of the digital threshold deserves further attention. In the 1990s, product merchandising has become an increasingly important part of financing the globalised film industry.While some would date this from Star Wars, Jurassic Park offers a more relevant point of reference: for the first time, audiences could see on screen, as an integral part of the filmic diegesis, the same commodities they could purchase in the cinema foyer. As Lucie Fjeldstad (then head of IBM’s multimedia division) remarked at the time (1993) : ‘Digital conten t is a return-on-assets goldmine, because once you create Terminator 3, the character, it can be used in movies, in theme-park rides, videogames, books, educational products’. 45 Digital convergence is enacted not simply in the journey from large screen to small screen: the same parameters used in designing CG characters for a film can easily be transmitted to off-shore factories manufacturing plastic toys.