Project 6

Heart Attack (Myocardial Infarction) •

Heart attack A heart attack (also known as a myocardial infarction) is the death of heart muscle from the sudden blockage of a coronary artery by a blood clot. Coronary arteries are blood vessels that supply the heart muscle with blood and oxygen. Blockage of a coronary artery deprives the heart muscle of blood and oxygen,causing injury to the heart muscle. Injury to the heart muscle causes chest pain and chest pressure sensation. If blood flow is not restored to the heart muscle within 20 to 40 minutes, irreversible death of the heart muscle will begin to occur. Muscle continues to die for six to eight hours at which time the heart attack usually is "complete." The dead heart muscle is eventually replaced by scar tissue.Approximately one million Americans suffer a heart attack each year. Four hundred thousand of them die as a result of their heart attack.

Causes for heart attack Atherosclerosis Atherosclerosis is a gradual process by which plaques (collections) of cholesterol are deposited in the walls of arteries. Cholesterol plaques cause hardening of the arterial walls and narrowing of the inner channel (lumen) of the artery. Arteries that are narrowed by atherosclerosis cannot deliver enough blood to maintain normal function of the parts of the body they supply. For example, atherosclerosis of the arteries in the legs causes reduced blood flow to the legs. Reduced blood flow to the legs can lead to pain in the legs while walking or exercising, leg ulcers, or a delay in the healing of wounds to the legs. Atherosclerosis of the arteries that furnish blood to the brain can lead to vascular dementia (mental deterioration due to gradual death of brain tissue over many years) or stroke (sudden death of brain tissue). In many people, atherosclerosis can remain silent (causing no symptoms or health problems) for years or decades. Atherosclerosis 1

can begin as early as the teenage years, but symptoms or health problems usually do not arise until later in adulthood when the arterial narrowing becomes severe. Smoking cigarettes, high blood pressure, elevated cholesterol, and diabetes mellitus can accelerate atherosclerosis and lead to the earlier onset of symptoms and complications, particularly in those people who have a family history of early atherosclerosis. Coronary atherosclerosis (or coronary artery disease) refers to the atherosclerosis that causes hardening and narrowing of the coronary arteries. Diseases caused by the reduced blood supply to the heart muscle from coronary atherosclerosis are called coronary heart diseases (CHD). Coronary heart diseases include heart attacks, sudden unexpected death, chest pain (angina), abnormal heart rhythms, and heart failure due to weakening of the heart muscle.

Atherosclerosis

and

angina

pectoris

Angina pectoris (also referred to as angina) is chest pain or pressure that occurs when the blood and oxygen supply to the heart muscle cannot keep up with the needs of the muscle. When coronary arteries are narrowed by more than 50 to 70 percent, the arteries may not be able to increase the supply of blood to the heart muscle during exercise or other periods of high demand for oxygen. An insufficient supply of oxygen to the heart muscle causes angina. Angina that occurs with exercise or exertion is called exertional angina. In some patients, especially diabetics, the progressive decrease in blood flow to the heart may occur without any pain or with just shortness of breath or unusually early fatigue. Exertional angina usually feels like a pressure, heaviness, squeezing, or aching across the chest. This pain may travel to the neck, jaw, arms, back, or even the teeth, and may be accompanied by shortness of breath, nausea, or a cold sweat. Exertional angina typically lasts from one to 15 minutes and is relieved by rest or by taking nitroglycerin by placing a tablet under the tongue. Both resting and nitroglycerin decrease the heart muscle's demand for oxygen, thus relieving angina. Exertional angina may be the first warning sign of advanced coronary artery disease. Chest pains that just last a few seconds rarely are due to coronary artery disease. Angina also can occur at rest. Angina at rest more commonly indicates that a coronary artery has narrowed to such a critical degree that the

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heart is not receiving enough oxygen even at rest. Angina at rest infrequently may be due to spasm of a coronary artery (a condition called Prinzmetal's or variant angina). Unlike a heart attack, there is no permanent muscle damage with either exertional or rest angina.

Atherosclerosis and heart attack Occasionally the surface of a cholesterol plaque in a coronary artery may rupture, and a blood clot forms on the surface of the plaque. The clot blocks the flow of blood through the artery and results in a heart attack (see picture below). The cause of rupture that leads to the formation of a clot is largely unknown, but contributing factors may include cigarette smoking or other nicotine exposure, elevated LDL cholesterol, elevated levels of blood catecholamines (adrenaline), high blood pressure, and other mechanical and biochemical forces. Unlike exertional or rest angina, heart muscle dies during a heart attack and loss of the muscle is permanent, unless blood flow can be promptly restored, usually within one to six hours.

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While heart attacks can occur at any time, more heart attacks occur between 4:00 A.M. and 10:00 A.M. because of the higher blood levels of adrenaline released from the adrenal glands during the morning hours. Increased adrenaline, as previously discussed, may contribute to rupture of cholesterol plaques. Approximately 50% of patients who develop heart attacks have warning symptoms such as exertional angina or rest angina prior to their heart

How is a heart attack diagnosed When there is severe chest pain, suspicion that a heart attack is occurring usually is high, and tests can be performed quickly that will confirm the heart attack. A problem arises, however, when the symptoms of a heart attack do not include chest pain. A heart attack may not be suspected, and the appropriate tests may not be performed. Therefore, the initial step in diagnosing a heart attack is to be suspicious that one has occurred. •

Electrocardiogram.

An electrocardiogram (ECG) is a recording of the electrical activity of the heart. Abnormalities in the electrical activity usually occur with heart attacks and can identify the areas of heart muscle that are deprived of oxygen and/or areas of muscle that have died. In a patient with typical symptoms of heart attack (such as crushing chest pain) and characteristic changes of heart attack on the ECG, a secure diagnosis of heart attack can be made quickly in the emergency room and treatment can be started immediately. If a patient's symptoms are vague or atypical and if there are preexisting ECG abnormalities Ffor example, from old heart attacks or abnormal electrical patterns that make interpretation of the ECG difficult, the diagnosis of a heart attack may be less secure. In these patients, the diagnosis can be made only hours later through detection of elevated cardiac enzymes in the blood.

Blood tests.

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Cardiac enzymes are proteins that are released into the blood by dying heart muscles. These cardiac enzymes are creatine phosphokinase (CPK), special sub-fractions of CPK (specifically, the MB fraction of CPK), and troponin, and their levels can be measured in blood. These cardiac enzymes typically are elevated in the blood several hours after the onset of a heart attack. A series of blood tests for the enzymes performed over a 24-hour period are useful not only in confirming the diagnosis of heart attack The changes in their levels over time also correlates with the amount of heart muscle that has died.

The most important factor in diagnosing Rapid evaluation allows early treatment of potentially life-threatening abnormal rhythms such as ventricular fibrillation and allows early reperfusion (return of blood flow to the heart muscle) by procedures that unclog the blocked coronary arteries. The more rapidly blood flow is reestablished, the more heart muscle that is saved. Large and active medical centers often have a "chest pain unit" where patients suspected of having heart attacks are rapidly evaluated. heart attack is diagnosed, prompt therapy is initiated.

What is new in heart attack Greater public awareness about heart attacks and changes in lifestyle have contributed to a dramatic reduction in the incidence of heart attacks during the last four decades. Improved anticoagulant drugs such as hirudin and hirulog, are being tested and may complement current therapies. The role of the "super aspirins" [abciximab (Reopro) and eptifibatide (Integrilin)] is currently being investigated as well. More effective versions of TPA are being developed. Increasingly, paramedics can do ECGs in the field, diagnose a heart attack, and take patients directly to hospitals that have the ability to do PTCA and stenting. This can save time and reduce damage to the heart. At present, the accepted best treatment for a heart attack is identification promptly of the diagnosis, and transport to a hospital that can perform prompt

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catheterization and PTCA or stenting within the first 90 minutes of the cardiac event. Research also has shown that inflammation may play a role in the development of atherosclerosis, and this is an active area of current investigation.

Treatment for heart attack Thrombolytic (fibrinolytic or clot dissolving) therapy has been shown to reduce death from heart attacks similarly in men and women; however, the complication of strokes from the thrombolytic therapy may be slightly higher in women than in men. Emergency percutaneous transluminal coronary angioplasty (PTCA) or coronary stenting for acute heart attack is as effective in women as in men; however women may have a slightly higher rate of procedure-related complications in their blood vessels (such as bleeding or clotting at the point of insertion of the PTCA catheter in the groin) and death. This higher rate of complications has been attributed to women's older age, smaller artery size, and greater severity of angina. The long-term outcome of angioplasty or stenting however, is similar in men and women, and should not be withheld due to gender. The immediate mortality from coronary artery bypass graft surgery (CABG) in women is higher than that for men. The higher immediate mortality rate has been attributed to women's older age, smaller artery size, and greater severity of angina

Prevention of Heart Attack: Reasonable advice includes the following: The cardiovascular benefits of regular exercise are a diminished tendency of blood to form clots, an improved cholesterol profile, more efficient use of oxygen by the muscles. a larger volume of blood pumped with each heartbeat, and during periods of exertion, greater dilation of the arteries, a lower heart rate and lower blood pressure.

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Start slow and easy:For the first week or two, exercise at an easy pace for no more than 10 to 20 minutes at a time. Build up gradually – As a general rule, do not increase either the intensity, frequency or duration of your exercise sessions by more than 10 percent each week. Exercise often – It is safer to get modest amounts of exercise several times a week than to try making up for days or weeks of inactivity with a single, prolonged workout. Do not overexert – Beginners should avoid pushing their heart rate higher than 70 percent of its maximum. (Your maximum rate equals roughly 220 minus your age). Warm up – Begin every workout with a gentle warm-up to boost circulation to the heart muscle. Jog in place, ride a stationary bicycle or do calisthenic exercise for a few minutes. Then stretch to reduce the risk of injury. Cool down – Rapid muscle movement helps pump blood back to the heart. If you stop exercising abruptly, the heart's blood supply may drop abruptly. Do not eat and run – During and after a meal, the body sends extra blood to the digestive organs, leaving less blood for the heart and muscles. Try to wait at least two hours after a heavy meal before exercising. Watch the weather – Blood vessels in the skin and the limbs constrict when it is cold outside, making it more difficult for the heart to pump blood throughout the body. If you exercise outdoors in frigid weather, dress in warm layers and do not push yourself too hard. Working out in hot weather can also threaten the heart, since heavy sweating decreases the total volume of blood, and in turn, the amount flowing to the heart muscle. Take pollution to heart - Exercising in polluted air increases blood levels of carbon monoxide, which raises the risk of heart attack by replacing oxygen in the blood.

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SWINE FLU(H1N1)

swine flu (novel H1N1 influenza A swine flu) Swine flu (swine influenza) is a respiratory disease caused by viruses (influenza viruses) that infect the respiratory tract of pigs and result in nasal secretions, a barking-like cough, decreased appetite, and listless behavior. Swine flu produces most of the same symptoms in pigs as human flu produces in people. Swine flu can last about one to two weeks in pigs that survive. Swine influenza virus was first isolated from pigs in 1930 in the U.S. and has been recognized by pork producers and veterinarians to cause infections in pigs worldwide. 0 In a number of instances, people have developed the swine flu infection when they are closely associated with pigs (for example, farmers, pork processors), and likewise, pig populations have occasionally been infected with the human flu infection. In most instances, the cross-species infections (swine virus to man; human flu virus to pigs) have remained in local areas and have not caused national or worldwide infections in either pigs or humans. Unfortunately, this cross-species situation with influenza viruses has had the potential to change. Investigators think the 2009 swine flu strain, first seen in Mexico, should be termed novel H1N1 flu since it is mainly found infecting people and exhibits two main surface antigens, H1 (hemagglutinin type 1) and N1 (neuraminidase type1). Recent investigations show the eight RNA strands from novel H1N1 flu have one strand derived from human flu strains, two from avian (bird) strains, and five from swine strains.

History of swine flu (H1N1) in humans In 1976, there was an outbreak of swine flu at Fort Dix. This virus is not the same as the 2009 outbreak, but it was similar insofar as it was an influenza A virus that had similarities to the swine flu virus. There was one death at Fort Dix.

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The government decided to produce a vaccine against this virus, but the vaccine was associated with neurological complications (GuillainBarré syndrome) and was discontinued. Some individuals speculate that formalin, used to inactivate the virus, may have played a role in the development of this complication in 1976. There is no evidence that anyone who obtained this vaccine would be protected against the 2009 swine flu. One of the reasons it takes a few months to develop a new vaccine is to test the vaccine for safety to avoid the complications seen in the 1976 vaccine. New vaccines against any flu virus type are usually made by growing virus particles in eggs. A serious side effect (allergic reaction such as swelling of the airway) to vaccines can occur in people who are allergic to eggs; these people should not get flu vaccines. Individuals with active infections or diseases of the nervous system are also not recommended to get flu vaccines.

Why is swine flu (H1N1) now infecting humans Many researchers now consider that two main series of events can lead to swine flu (and also avian or bird flu) becoming a major cause for influenza illness in humans. First, the influenza viruses (types A, B, C) are enveloped RNA viruses with a segmented genome; this means the viral RNA genetic code is not a single strand of RNA but exists as eight different RNA segments in the influenza viruses. A human (or bird) influenza virus can infect a pig respiratory cell at the same time as a swine influenza virus; some of the replicating RNA strands from the human virus can get mistakenly enclosed inside the enveloped swine influenza virus. For example, one cell could contain eight swine flu and eight human flu RNA segments. The total number of RNA types in one cell would be 16; four swine and four human flu RNA segments could be incorporated into one particle, making a viable eight RNA segmented flu virus from the 16 available segment types. Various combinations of RNA segments can result in a new subtype of virus (known as antigenic shift) that may have the ability to preferentially infect humans but still show characteristics unique to the swine influenza virus. 9

It is even possible to include RNA strands from birds, swine, and human influenza viruses into one virus if a cell becomes infected with all three types of influenza For example, two bird flu, three swine flu, and three human flu RNA segments to produce a viable eight-segment new type of flu viral genome). Formation of a new viral type is considered to be antigenic shift; small changes in an individual RNA segment in flu viruses are termed antigenic drift and result in minor changes in the virus. However, these can accumulate over time to produce enough minor changes that cumulatively change the virus' antigenic makeup over time (usually years). Second, pigs can play a unique role as an intermediary host to new flu types because pig respiratory cells can be infected directly with bird, human, and other mammalian flu viruses. Consequently, pig respiratory cells are able to be infected with many types of flu and can function as a "mixing pot" for flu RNA segments . Bird flu viruses, which usually infect the gastrointestinal cells of many bird species, are shed in bird feces. Pigs can pick these viruses up from the environment and seem to be the major way that bird flu virus RNA segments enter the mammalian flu virus population.

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Symptoms of swine flu (H1N1) Symptoms of swine flu are similar to most influenza infections: fever (100F or greater), cough, nasal secretions, fatigue, and headache, with fatigue being reported in most infected individuals. Some patients also get nausea, vomiting, and diarrhea. In Mexico, many of the patients are young adults, which made some investigators speculate that a strong immune response may cause some collateral tissue damage. Some patients develop severe respiratory symptoms and need respiratory support (such as a ventilator to breathe for the patient). Patients can get pneumonia (bacterial secondary infection) if the viral infection persists, and some can develop seizures. Death often occurs from secondary bacterial infection of the lungs; appropriate antibiotics need to be used in these patients. The usual mortality (death) rate for typical influenza A is about 0.1%, while the 1918 "Spanish flu" epidemic had an estimated mortality rate ranging from 2%-20%.

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Swine flu in Mexico (as of April 2009) has had about 160 deaths and about 2,500 confirmed cases, which would correspond to a mortality rate of about 6%, but these initial data have been revised and the mortality rate currently in Mexico is estimated to be much lower. By June 2009, the virus had reached 74 different countries on every continent except Antarctica, and by September 2009, the virus had been reported in most countries in the world. Fortunately, the mortality rate as of October 2009 has been low but higher than for the conventional flu (average conventional flu mortality rate is about 36,000 per year; projected novel H1N1 flu mortality rate is 90,000 per year in the U.S. as determined by the president's advisory committee).

swine flu (H1N1) diagnosed Swine flu is presumptively diagnosed clinically by the patient's history of association with people known to have the disease and their symptoms listed above. Usually, a quick test (for example, nasopharyngeal swab sample) is done to see if the patient is infected with influenza A or B virus. Most of the tests can distinguish between A and B types. The test can be negative (no flu infection) or positive for type A and B. If the test is positive for type B, the flu is not likely to be swine flu (H1N1). If it is positive for type A, the person could have a conventional flu strain or swine flu (H1N1). However, the accuracy of these tests has been challenged, and the U.S. Centers for Disease Control and Prevention (CDC) has not completed their comparative studies of these tests. A new test developed by the CDC and a commercial company reportedly can detect H1N1 reliably in about one hour; as of October 2009, the test is only available to the military. Swine flu (H1N1) is definitively diagnosed by identifying the particular antigens associated with the virus type. In general, this test is done in a specialized laboratory and is not done by many doctors' offices or hospital laboratories. However, doctors' offices are able to send specimens to specialized laboratories if necessary. Because of the large number of novel H1N1 swine flu cases (as of October 2009, the vast majority of flu cases [about 99%] are due to 12

novel H1N1 flu viruses), the CDC recommends only hospitalized patients' flu virus strains be sent to reference labs to be identified.

Treatment is available for swine flu (H1N1) The best treatment for influenza infections in humans is prevention by vaccination. Work by several laboratories has recently produced vaccines. The first vaccine released in early October 2009 was a nasal spray vaccine. It is approved for use in healthy individuals ages 2 through 49. This vaccine consists of a live attenuated H1N1 virus and should not be used in anyone who is pregnant or immunocompromised. The injectable vaccine, made from killed H1N1, became available in the second week of October. This vaccine is approved for use in ages 6 months to the elderly, including pregnant females. Both of these vaccines have been approved by the CDC only after they had conducted clinical trials to prove that the vaccines were safe and effective. Two antiviral agents have been reported to help prevent or reduce the effects of swine flu. They are zanamivir (Relenza) and oseltamivir (Tamiflu), both of which are also used to prevent or reduce influenza A and B symptoms. These drugs should not be used indiscriminately, because viral resistance to them can and has occurred. Also, they are not recommended if the flu symptoms already have been present for 48

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hours or more, although hospitalized patients may still be treated past the 48-hour guideline. Severe infections in some patients may require additional supportive measures such as ventilation support and treatment of other infections like pneumonia that can occur in patients with a severe flu infection. The CDC has suggested in their interim guidelines that pregnant females can be treated with the two antiviral agents.

Preventive measures for swine flu: 1.

The first preventive measure is to avoid contact with the pigs (swine) 2. Swine flu is communicable disease, so use the face masks to protect from the swine flu antigens.

3. Cover your nose and mouth when coughing or sneezing, using tissue when possible. Dispose this tissue by using only once 4. Avoid visiting the crowded places like theaters and prayer halls. This can be the spreading ground for Swine flu 5. Maintain good hygiene. Wash your hands frequently with soap and water to reduce the spread of virus. It would be better if you use alcohol sanitizers or Dettol for washing hands.

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6. Take a special care of children because they easily get infected with the Swine flu. It is okay if you don’t send them to school for few days. Many schools have even announced holidays. 7. Avoid eating outside food because it may be contaminated and may make you infected with the virus. 8. Don’t use the public urinals because many people spit there, which could lead to the spreading of the disease.

Tuberculosis

Tuberculosis Tuberculosis (TB) is an infectious disease caused by bacteria whose scientific name is Mycobacterium tuberculosis. It was first isolated in 1882 by a German physician named Robert Koch who received the Nobel prize for this discovery. TB most commonly affects the lungs but also can involve almost any organ of the body. Many years ago, this disease was referred to as "consumption" because without effective treatment, these patients often would waste away. Today, of course, tuberculosis usually can be treated successfully with antibiotics. There is also a group of organisms referred to as atypical tuberculosis. These involve other types of bacteria that are in the Mycobacterium family. Often, these organisms do not cause disease and are referred to a "colonizers," because they simply live alongside other bacteria in our bodies without causing damage. At times, these bacteria can cause an infection that is sometimes clinically like typical tuberculosis. When these atypical mycobacteria cause infection, they are often very difficult to cure. Often, drug therapy for these organisms must be administered for one and a half to two years and requires multiple medication

How common is TB, and who gets it? Over 8 million new cases of TB occur each year worldwide. In the United States, it is estimated that 10-15 million people are infected with the TB bacteria and 22,000 new cases of TB occur each year. 15

Anyone can get TB, but certain people are at higher risk, including •

people who live with individuals who have an active TB infection,

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poor or homeless people,

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foreign-born people from countries that have a high prevalence of TB,

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nursing home residents and prison inmates,

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alcoholics and intravenous drug users,

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people with diabetes, certain cancers, and HIV infection (the AIDS virus), andhealth-care workers.

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There is no strong evidence for a genetically determined (inherited) susceptibility for TB.

symptoms of tuberculosis As previously mentioned, TB infection usually occurs initially in the upper part (lobe) of the lungs. The body's immune system, however, can stop the bacteria from continuing to reproduce. Thus, the immune system can make the lung infection inactive (dormant). On the other hand, if the body's immune system cannot contain the TB bacteria, the bacteria will reproduce (become active or reactivate) in the lungs and spread elsewhere in the body. It may take many months from the time the infection initially gets into the lungs until symptoms develop. The usual symptoms that occur with an active TB infection are a generalized tiredness or weakness, weight loss, fever, and night sweats. If the infection in the lung worsens, then further symptoms can include coughing, chest pain, coughing up of sputum (material from the lungs) and/or blood, and shortness of breath. If the infection spreads beyond the lungs, the symptoms will depend upon the organs involved.

How does a doctor diagnose tuberculosis

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TB can be diagnosed in several different ways, including chest x-rays, analysis of sputum, and skin tests. Sometimes, the chest x-rays can reveal evidence of active tuberculosis pneumonia. Other times, the x-rays may show scarring (fibrosis) or hardening (calcification) in the lungs, suggesting that the TB is contained and inactive. Examination of the sputum on a slide (smear) under the microscope can show the presence of the tuberculosis-like bacteria. Bacteria of the mycobacterium family, including atypical mycobacteria, stain positive with special dyes and are referred to as acid-fast bacteria (AFB). A sample of the sputum also is usually taken and grown (cultured) in special incubators so that the tuberculosis bacteria can subsequently be identified as tuberculosis or atypical tuberculosis. Several types of skin tests are used to screen for TB infection. These so-called tuberculin skin tests include the Tine test and the Mantoux test, also known as the PPD (purified protein derivative) test. In each of these tests, a small amount of purified extract from dead tuberculosis bacteria is injected under the skin. If a person is not infected with TB, then no reaction will occur at the site of the injection (a negative skin test). If a person is infected with tuberculosis. however, a raised and reddened area will occur around the site of the test injection. This reaction, a positive skin test, occurs about 48 to 72 hours after the injection. If the infection with tuberculosis has occurred recently, however, the skin test can be falsely negative. The reason for a false negative test with a recent infection is that it usually takes two to 10 weeks after the time of infection with tuberculosis before the skin test becomes positive. The skin test can also be falsely negative if a person's immune system is weakened or deficient due to another illness such as AIDS or cancer, or while taking medications that can suppress the immune response, such as cortisone or anticancer drugs. Remember, however, that the TB skin test cannot determine whether the disease is active or not. This determination requires the chest xrays and/or sputum analysis (smear and culture) in the laboratory. The organism can take up to six weeks to grow in culture in the microbiology lab. 17

A special test to diagnose TB called the PCR (polymerase chain reaction) detects the genetic material of the bacteria. This test is extremely sensitive (it detects minute amounts of the bacteria) and specific (it detects only the TB bacteria)

Treatment for tuberculosis: A person with a positive skin test, a normal chest x-ray, and no symptoms most likely has only a few TB germs in an inactive state and is not contagious. The antibiotic used for this purpose is called isoniazid (INH). If taken for six to 12 months, it will prevent the TB from becoming active in the future. In fact, if a person with a positive skin test does not take INH, there is a 5%-10% lifelong risk that the TB will become active. Taking isoniazid can be inadvisable (contraindicated) during pregnancy or for those suffering from alcoholism or liver disease. Also, isoniazid can have side effects. The side effects occur infrequently, but a rash can develop, and the patient can feel tired or irritable. Liver damage from isoniazid is a rare occurrence and typically reverses once the drug is stopped. It is important therefore, for the doctor to monitor a patient's liver by periodically ordering blood tests called "liver function tests" during the course of INH therapy. Another side effect of INH is a decreased sensation in the extremities referred to as a peripheral neuropathy. This can be avoided by taking vitamin B6 (pyridoxine), and this is often prescribed along with INH. A person with a positive skin test along with an abnormal chest x-ray and sputum evidencing TB bacteria has active TB and is contagious. As already mentioned, active TB usually is accompanied by symptoms, such as a cough, fever, weight loss, and fatigue. Active TB is treated with a combination of medications along with isoniazid. Rifampin (Rifadin), ethambutol (Myambutol), and pyrazinamide are the drugs commonly used to treat active TB in conjunction with isoniazid (INH). Four drugs are often taken for the first two months of therapy to help kill any potentially resistant strains of bacteria. Then the number is usually reduced to two drugs for the remainder of the treatment based on drug sensitivity testing that is usually available by this time in the course. 18

Streptomycin, a drug that is given by injection, may be used as well, particularly when the disease is extensive and/or the patients do not take their oral medications reliably (termed "poor compliance"). Successful treatment of TB is dependent largely on the compliance of the patient. Indeed, the failure of a patient to take the medications is the most important cause of failure to cure the TB infection. In some locations, the health department demands direct monitoring of patient compliance with therapy. Without treatment, however, tuberculosis can be a lethal infection. Therefore, early diagnosis is important. Those individuals who have been exposed to a person with TB, or suspect that they have been, should be exami examined by a doctor for signs of TB and screened with a TB skin test.

drug-resistant TB Drug-resistant TB (TB that does not respond to drug treatment) has become a very serious problem in recent years in certain populations. For example, INH-resistant TB is seen among patients from Southeast Asia.. However, the major reason for the development of resistance is poorly managed TB care. This can result from poor patient compliance, inappropriate dosing or prescribing of medication, poorly formulated medications, and/or an inadequate supply of medication. Multidrug-resistant tuberculosis (MDR-TB) refers to organisms that are resistant to at least two of the first-line drugs, INH and Rifampin. More recently, extensively (extremely) drug resistant tuberculosis (XDR-TB) has emerged. These bacteria are also resistant to three or more of the second-line treatment drugs. . Prevention of Tuberculosis Preventive measures include strict standards for ventilation, air filtration, and isolation methods in hospitals, medical and dental offices, nursing homes, and prisons. If someone is believed to have been in contact with another person who has TB, preventive antibiotic treatment may have to be given. Infected persons need to be

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identified as soon as possible so that they can be isolated from others and treated. An antituberculosis vaccine, bacille Calmette-Guérin, or BCG vaccine, was developed in France in 1908. Although there is conflicting evidence as to its efficacy (it appears to be effective in 50% of those vaccinated), it is given to over 80% of the world's children, mostly in countries where TB is common; it is not generally given in the United States. Federal health officials in the United States have stated (1999) that a new vaccine is essential to TB prevention.

Systemic Lupus Erythematosus (SLE or Lupus) Lupus: Lupus is an autoimmune disease characterized by acute and chronic inflammation of various tissues of the body. Autoimmune diseases are illnesses that occur when the body's tissues are attacked by its own immune system. The immune system is a complex system within the body that is designed to fight infectious agents, such as bacteria and other foreign microbes. One of the ways that the immune system fights infections is by producing antibodies that bind to the microbes. Patients with lupus produce abnormal antibodies in their blood that target tissues within their own body rather than foreign infectious agents. Because the antibodies and accompanying cells of inflammation can affect tissues anywhere in the body, lupus has the potential to affect a variety of areas

Types of lupus . Sometimes lupus can cause disease of the skin, heart, lungs, kidneys, joints, and/or nervous system. When only the skin is involved, the condition is called lupus dermatitis or cutaneous lupus erythematosus. A form of lupus dermatitis that can be isolated to the skin, without internal disease, is called discoid lupus. When internal organs are involved, the condition is referred to as systemic lupus erythematosus (SLE).

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Both discoid and systemic lupus are more common in women than men (about eight times more common). The disease can affect all ages but most commonly begins from 20 to 45 years of age. Statistics demonstrate that lupus is somewhat more frequent in African Americans and people of Chinese and Japanese descent.

CAUSES OF LUPUS: The precise reason for the abnormal autoimmunity that causes lupus is not known. Inherited genes, viruses, ultraviolet light, and certain medications may all play some role. Genetic factors increase the tendency of developing autoimmune diseases, and autoimmune diseases such as lupus, rheumatoid arthritis, and autoimmune thyroid disorders are more common among relatives of patients with lupus than the general population. Some scientists believe that the immune system in lupus is more easily stimulated by external factors like viruses or ultraviolet light. Sometimes, symptoms of lupus can be precipitated or aggravated by only a brief period of sun exposure. It also is known that some women with SLE can experience worsening of their symptoms prior to their menstrual periods. This phenomenon, together with the female predominance of SLE, suggest that female hormones play an important role in the expression of SLE. This hormonal relationship is an active area of ongoing study by scientists. More recently, research has demonstrated evidence that a key enzyme's failure to dispose of dying cells may contribute the development of SLE. The enzyme, DNase1, normally eliminates what is called "garbage DNA" and other cellular debris by chopping them into tiny fragments for easier disposal. Researchers turned off the DNase1 gene in mice. The mice appeared healthy at birth, but after six to eight months, the majority of mice without DNase1 showed signs of SLE. Thus, a genetic mutation in a gene that could disrupt the body's cellular waste disposal may be involved in the initiation of SLE

symptoms and signs of lupus Patients with SLE can develop different combinations of symptoms and organ involvement. Common complaints and symptoms include fatigue, low-grade fever, loss of appetite, muscle aches, arthritis, ulcers of the mouth and nose, facial rash ("butterfly rash"), unusual sensitivity to sunlight (photosensitivity), inflammation of the lining that surrounds the lungs (pleuritis)

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and the heart (pericarditis), and poor circulation to the fingers and toes with cold exposure (Raynaud's phenomenon). Complications of organ involvement can lead to further symptoms that depend on the organ affected and severity of the disease. Skin manifestations are frequent in lupus and can sometimes lead to scarring. In discoid lupus, only the skin is typically involved. The skin rash in discoid lupus often is found on the face and scalp. It usually is red and may have raised borders. Discoid lupus rashes are usually painless and do not itch, but scarring can cause permanent hair loss. Over time, 5%-10% of patients with discoid lupus may develop SLE. Over half of the patients with SLE develop a characteristic red, flat facial rash over the bridge of their nose. Because of its shape, it is frequently referred to as the "butterfly rash" of SLE. The rash is painless and does not itch. The facial rash, along with inflammation in other organs, can be precipitated or worsened by exposure to sunlight, a condition called photosensitivity. This photosensitivity can be accompanied by worsening of inflammation throughout the body, called a "flare" of the disease.

Typically, this rash can heal without permanent scarring with treatment. Most patients with SLE will develop arthritis during the course of their illness. Arthritis in SLE commonly involves swelling, pain, stiffness, and

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even deformity of the small joints of the hands, wrists, and feet. Sometimes, the arthritis of SLE can mimic that of rheumatoid arthritis (another autoimmune disease). More serious organ involvement with inflammation occurs in the brain, liver, and kidneys. White blood cells and blood-clotting factors also can be characteristically decreased in SLE, known as leucopenia and thrombocytopenia, respectively. Leucopenia can increase the risk of infection and thrombocytopenia can increase the risk of bleeding. Inflammation of muscles (myositis) can cause muscle pain and weakness. This can lead to elevations of muscle enzyme levels in the blood. Inflammation of blood vessels (vasculitis) that supply oxygen to tissues can cause isolated injury to a nerve, the skin, or an internal organ. The blood vessels are composed of arteries that pass oxygen-rich blood to the tissues of the body and veins that return oxygen-depleted blood from the tissues to the lungs. Vasculitis is characterized by inflammation with damage to the walls of various blood vessels. The damage blocks the circulation of blood through the vessels and can cause injury to the tissues that are supplied with oxygen by these vessels. Inflammation of the lining of the lungs (pleuritis) and of the heart (pericarditis) can cause sharp chest pain. The chest pain is aggravated by coughing, deep breathing, and certain changes in body position. The heart muscle itself rarely can become inflamed (carditis). It has also been shown that young women with SLE have a significantly increased risk of heart attacks from coronary artery disease. Kidney inflammation in SLE can cause leakage of protein into the urine, fluid retention, high blood pressure, and even kidney failure. This can lead to further fatigue and swelling of the legs and feet. With kidney failure, machines are needed to cleanse the blood of accumulated poisons in a process called dialysis. Involvement of the brain can cause personality changes, thought disorders (psychosis), seizures, and even coma. Damage to nerves can cause numbness, tingling, and weakness of the involved body parts or extremities. Brain involvement is referred to as lupus cerebritis. Many patients with SLE experience hair loss (alopecia). Often, this occurs simultaneously with an increase in the activity of their disease. The hair loss can be patchy or diffuse and appear to be more like hair thinning. 23

Some patients with SLE have Raynaud's phenomenon. In these patients, the blood supply to the fingers and/or toes becomes compromised upon exposure to cold, causing blanching, whitish and/or bluish discoloration, and pain and numbness in the exposed fingers and toes.

How is lupus diagnosed Since patients with SLE can have a wide variety of symptoms and different combinations of organ involvement, no single test establishes the diagnosis of systemic lupus. To help doctors improve the accuracy of the diagnosis of SLE, 11 criteria were established by the American Rheumatism Association. These 11 criteria are closely related to the symptoms discussed above. Some patients suspected of having SLE may never develop enough criteria for a definite diagnosis. Other patients accumulate enough criteria only after months or years of observation. When a person has four or more of these criteria, the diagnosis of SLE is strongly suggested. Nevertheless, the diagnosis of SLE may be made in some settings in patients with only a few of these classical criteria, and treatment may sometimes be instituted at this stage. Of these patients with minimal criteria, some may later develop other criteria, but many never do. The 11 criteria used for diagnosing systemic lupus erythematosus are •

malar (over the cheeks of the face) "butterfly" rash,

•

discoid skin rash (patchy redness with hyperpigmentation and hypopigmentation that can cause scarring),

•

photosensitivity (skin rash in reaction to sunlight [ultraviolet light] exposure),

•

mucous membrane ulcers (spontaneous ulcers of the lining of the mouth, nose, or throat),

•

arthritis (two or more swollen, tender joints of the extremities),

•

pleuritis or pericarditis (inflammation of the lining tissue around the heart or lungs, usually associated with chest pain upon breathing or changes of body position),

•

kidney abnormalities (abnormal amounts of urine protein or clumps of cellular elements called casts detectable with a urinalysis),

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•

brain irritation (manifested by seizures [convulsions] and/or psychosis),

•

blood-count abnormalities (low counts of white or red blood cells, or platelets, on routine blood testing),

•

immunologic disorder (abnormal immune tests include anti-DNA or anti-Sm [Smith] antibodies, falsely positive blood test for syphilis, anticardiolipin antibodies, lupus anticoagulant, or positive LE prep test), and

•

antinuclear antibody (positive ANA antibody testing [antinuclear antibodies in the blood]).

In addition to the 11 criteria, other tests can be helpful in evaluating patients with SLE to determine the severity of organ involvement. These include routine testing of the blood to detect inflammation (for example, tests called the sedimentation rate and C-reactive protein), blood-chemistry testing, direct analysis of internal body fluids, and tissue biopsies. Abnormalities in body fluids and tissue samples (kidney, skin, and nerve biopsies) can further support the diagnosis of SLE. The appropriate testing procedures are selected for the patient individually by the doctor

Treatment for systemic lupus There is no permanent cure for SLE. The goal of treatment is to relieve symptoms and protect organs by decreasing inflammation and/or the level of autoimmune activity in the body. Many patients with mild symptoms may need no treatment or only intermittent courses of antiinflammatory medications. Those with more serious illness involving damage to internal organ(s) may require high doses of corticosteroids in combination with other medications that suppress the body's immune system. Patients with SLE need more rest during periods of active disease. Researchers have reported that poor sleep quality was a significant factor in developing fatigue in patients with SLE. These reports emphasize the importance for patients and physicians to address sleep quality and the effect of underlying depression, lack of exercise, and self-care coping strategies on overall health. During these periods, carefully prescribed exercise is still important to maintain muscle tone and range of motion in the joints. Nonsteroidal antiinflammatory drugs (NSAIDs) are helpful in reducing inflammation and pain in muscles, joints, and other tissues. Examples of NSAIDs include aspirin, ibuprofen (Motrin), naproxen (Naprosyn),

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and sulindac (Clinoril). Since the individual response to NSAIDs varies among patients, it is common for a doctor to try different NSAIDs to find the most effective one with the fewest side effects. The most common side effects are stomach upset, abdominal pain, ulcers, and even ulcer bleeding. NSAIDs are usually taken with food to reduce side effects. Sometimes, medications that prevent ulcers while taking NSAIDs, such as misoprostol (Cytotec), are given simultaneously. Corticosteroids are more potent than NSAIDs in reducing inflammation and restoring function when the disease is active. Corticosteroids are particularly helpful when internal organs are affected. Corticosteroids can be given by mouth, injected directly into the joints and other tissues, or administered intravenously. Unfortunately, corticosteroids have serious side effects when given in high doses over prolonged periods, and the doctor will try to monitor the activity of the disease in order to use the lowest doses that are safe. Side effects of corticosteroids include weight gain, thinning of the bones and skin, infection, diabetes, facial puffiness, cataracts, and death (necrosis) of the tissues in large joints. Hydroxychloroquine (Plaquenil) is an antimalarial medication found to be particularly effective for SLE patients with fatigue, skin involvement, and joint disease. Consistently taking Plaquenil can prevent flare-ups of lupus. Side effects are uncommon but include diarrhea, upset stomach, and eyepigment changes. Eye-pigment changes are rare but require monitoring by an ophthalmologist (eye specialist) during treatment with Plaquenil. Researchers have found that Plaquenil significantly decreased the frequency of abnormal blood clots in patients with systemic lupus. Moreover, the effect seemed independent of immune suppression, implying that Plaquenil can directly act to prevent the blood clots. This fascinating study highlights an important reason for patients and doctors to consider Plaquenil for long-term use, especially for those SLE patients who are at some risk for blood clots in veins and arteries, such as those with phospholipid antibodies (cardiolipin antibodies, lupus anticoagulant, and false-positive venereal disease research laboratory test). This means not only that Plaquenil reduces the chance for re-flares of SLE, but it can also be beneficial in thinning the blood to prevent abnormal excessive blood clotting. Plaquenil is commonly used in combination with other treatments for lupus.

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For resistant skin disease, other antimalarial drugs, such as chloroquine (Aralen) or quinacrine, are considered and can be used in combination with hydroxychloroquine. Alternative medications for skin disease include dapsone and retinoic acid (Retin-A). Retin-A is often effective for an uncommon wart-like form of lupus skin disease. For more severe skin disease, immunosuppressive medications are considered as described below. Medications that suppress immunity (immunosuppressive medications) are also called cytotoxic drugs. Immunosuppressive medications are used for treating patients with more severe manifestations of SLE, such as damage to internal organ(s). Examples of immunosuppressive medications include methotrexate (Rheumatrex, Trexall), azathioprine (Imuran), cyclophosphamide (Cytoxan), chlorambucil (Leukeran), and cyclosporine (Sandimmune). All immunosuppressive medications can seriously depress blood-cell counts and increase risks of infection and bleeding. Other side effects are specific for each drug. For examples, Rheumatrex can cause liver toxicity, while Sandimmune can impair kidney function. In recent years, mycophenolate mofetil (Cellcept) has been used as an effective medication for lupus, particularly when it is associated with kidney disease. Cellcept has been helpful in reversing active lupus kidney disease (lupus renal disease) and in maintaining remission after it is established. Its lower side-effect profile has advantage over traditional immune-suppression medications. In SLE patients with serious brain or kidney disease, plasmapheresis is sometimes used to remove antibodies and other immune substances from the blood to suppress immunity. Rarely, SLE patients can develop seriously low platelet levels, thereby increasing the risk of excessive and spontaneous bleeding. Since the spleen is believed to be the major site of platelet destruction, surgical removal of the spleen is sometimes performed to improve platelet levels. Other treatments have included hormones. Plasmapheresis has (cryoglobulins) that can lead to from SLE requires dialysis and/or

plasmapheresis and the use of male also been used to remove proteins vasculitis. End-stage kidney damage a kidney transplant.

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Most recent research is indicating benefits of rituximab (Rituxan) in treating lupus. Rituximab is an intravenously infused antibody that suppresses a particular white blood cell, the B cell, by decreasing their number in the circulation. B cells have been found to play a central role in lupus activity, and when they are suppressed, the disease tends toward remission. This may particularly helpful for patients with kidney disease

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CT SCAN: What is CT Scanning of the Body? CT scanning—sometimes called CAT scanning—is a noninvasive medical test that helps physicians diagnose and treat medical conditions.

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CT scanning combines special x-ray equipment with sophisticated computers to produce multiple images or pictures of the inside of the body. These cross-sectional images of the area being studied can then be examined on a computer monitor or printed. CT scans of internal organs, bone, soft tissue and blood vessels provide greater clarity and reveal more details than regular x-ray exams. Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders.

some common uses

CT imaging is:  one of the best and fastest tools for studying the chest, abdomen and pelvis because it provides detailed, cross-sectional views of all types of tissue.  often the preferred method for diagnosing many different cancers, including lung, liver and pancreatic cancer, since the image allows a physician to confirm the presence of a tumor and measure its size, precise location and the extent of the tumor's involvement with other nearby tissue.  an examination that plays a significant role in the detection, diagnosis and treatment of vascular diseases that can lead to stroke, kidney failure or even death. CT is commonly used to assess for pulmonary embolism (a blood clot in the lung vessels) as well as for abdominal aortic aneurysms (AAA).  invaluable in diagnosing and treating spinal problems and injuries to the hands, feet and other skeletal structures because it can clearly show even very small bones as well as surrounding tissues such as muscle and blood vessels. Physicians often use the CT examination to:  quickly identify injuries to the lungs, heart and vessels, liver, spleen, kidneys, bowel or other internal organs in cases of trauma.

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   

guide biopsies and other procedures such as abscess drainages and minimally invasive tumor treatments. plan for and assess the results of surgery, such as organ transplants or gastric bypass. stage, plan and properly administer radiation treatments for tumors as well as monitor response to chemotherapy. measure bone mineral density for the detection of osteoporosis.

What does the equipment look like?

The CT scanner is typically a large, box like machine with a hole, or short tunnel, in the center. You will lie on a narrow examination table that slides into and out of this tunnel. Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate room, where the technologist operates the scanner and monitors your examination.

How does the procedure work? In many ways CT scanning works very much like other x-ray examinations. X-rays are a form of radiation—like light or radio waves —that can be directed at the body. Different body parts absorb the xrays in varying degrees.

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CAT scan: liver

In a conventional x-ray exam, a small burst of radiation is aimed at and passes through the body, recording an image on photographic film or a special image recording plate. Bones appear white on the x-ray; soft tissue shows up in shades of gray and air appears black.

With CT scanning, numerous x-ray beams and a set of electronic x-ray detectors rotate around you, measuring the amount of radiation being absorbed throughout your body. At the same time, the examination table is moving through the scanner, so that the x-ray beam follows a spiral path A special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. This technique is called helical or spiral CT.

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CT imaging is sometimes compared to looking into a loaf of bread by cutting the loaf into thin slices. When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior.

Refinements in detector technology allow new CT scanners to obtain multiple slices in a single rotation. These scanners, called "multislice CT" or "multidetector CT," allow thinner slices to be obtained in a shorter period of time, resulting in more detail and additional view capabilities. Modern CT scanners are so fast that they can scan through large sections of the body in just a few seconds. Such speed is beneficial for all patients but especially children, the elderly and critically ill. For some CT exams, a contrast material is used to enhance visibility in the area of the body being studied.

How is the CAT scan performed? The technologist begins by positioning you on the CT examination table, usually lying flat on your back or possibly on your side or on your stomach. Straps and pillows may be used to help you maintain the correct position and to hold still during the exam. If contrast material is used, it will be swallowed, injected through an intravenous line (IV) or administered by enema, depending on the type of examination.

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Next, the table will move quickly through the scanner to determine the correct starting position for the scans. Then, the table will move slowly through the machine as the actual CT scanning is performed. You may be asked to hold your breath during the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This is similar to the blurring seen on a photograph taken of a moving object. When the examination is completed, you will be asked to wait until the technologist verifies that the images are of high enough quality for accurate interpretation. CT scanning of the body is usually completed within 30 minutes.

What will I experience procedure?

during

and

after

the

CT exams are generally painless, fast and easy. With helical CT, the amount of time that the patient needs to lie still is reduced. Though the scanning itself causes no pain, there may be some discomfort from having to remain still for several minutes. If you have a hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer you a mild sedative to help you tolerate the CT scanning procedure. If an intravenous contrast material is used, you will feel a slight pin prick when the needle is inserted into your vein. You may have a warm, flushed sensation. during the injection of the contrast materials and a metallic taste in your mouth that lasts for a few minutes. Some patients may experience a sensation like they have to urinate but this subsides quickly. If the contrast material is swallowed, you may find the taste mildly unpleasant; however, most patients can easily tolerate it. You can expect to experience a sense of abdominal fullness and an increasing need to

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expel the liquid if your contrast material is given by enema. In this case, be patient, as the mild discomfort will not last long. When you enter the CT scanner, special lights may be used to ensure that you are properly positioned. With modern CT scanners, you will hear only slight buzzing, clicking and whirring sounds as the CT scanner revolves around you during the imaging process. You will be alone in the exam room during the CT scan. However, the technologist will be able to see, hear and speak with you at all times. With pediatric patients, a parent may be allowed in the room but will be required to wear a lead apron to prevent radiation exposure. After a CT exam, you can return to your normal activities. If you received contrast material, you may be given special instructions.

Who interprets the results and how do I get them A physician, usually a radiologist with expertise in supervising and interpreting radiology examinations, will analyze the images and send a signed report to your primary care physician or the physician who referred you for the exam, who will discuss the results with you.

USES OF CT SCAN: CT scans are used to study areas of the body and the arms or legs. Chest (thorax). A CT scan of the chest can look for problems with the lungs, heart, esophagus, the major blood vessel (aorta), or the tissues in the center of the chest. Some common chest problems a CT scan may find include infection, lung cancer, a pulmonary embolism, and an aneurysm. It also can be used to see if cancer has spread into the chest from another area of the body.

Abdomen.

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A CT scan of the abdomen can find cysts, abscesses, infection, tumors, an aneurysm, enlarged lymph nodes, foreign objects, bleeding in the belly, diverticulitis, inflammatory bowel disease, and appendicitis. Urinary tract. A CT scan of the kidneys, ureters, and bladder is called a CT KUB or CT urogram. This type of scan can find kidney stones, bladder stones, or blockage of the urinary tract. See a picture of a CT of diseased kidneys . A special type of CT scan, called a CT intravenous pyelogram (IVP), uses injected dye (contrast material) to look for kidney stones, blockage, growths, infection, or other diseases of the urinary tract. Liver A CT scan can find liver tumors, bleeding from the liver, and liver diseases. A CT scan of the liver can help determine the cause of jaundice. Pancreas. A CT scan can find a tumor in the pancreas or inflammation of the pancreas (pancreatitis). Gallbladder and bile ducts A CT scan can be used to check for blockage of the bile ducts. Gallstones occasionally show up on a CT scan. But other tests, such as ultrasound, usually are used to find problems with the gallbladder and bile ducts. Adrenal glands A CT scan can find tumors or enlarged adrenal glands. Spleen. A CT scan can be used to check for an injury to the spleen or the size of the spleen. Pelvis A CT scan can look for problems of organs in the pelvis. For a woman, these include the uterus, ovaries, and fallopian tubes. For a man, the pelvic organs include the prostate gland and the seminal vesicles. Arm or leg

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A CT scan can look for problems of the arms or legs, including the shoulder, elbow, wrist, hand, hip, knee, ankle, or foot. Other uses for a CT scan A CT scan may be used to make sure a procedure is done correctly. For example, the doctor may use CT to guide a needle during a tissue biopsy or to guide the proper placement of a needle to drain an abscess. For people with cancer, a CT scan can help determine how much the cancer has spread. This is called staging the cancer.

Benefits vs Risks: Benefits: 

CT scanning is painless, noninvasive and accurate.



A major advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time.



Unlike conventional x-rays, CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, and blood vessels.



CT examinations are fast and simple; in emergency cases, they can reveal internal injuries and bleeding quickly enough to help save lives.



CT has been shown to be a cost-effective imaging tool for a wide range of clinical problems.



CT is less sensitive to patient movement than MRI.



CT can be performed if you have an implanted medical device of any kind, unlike MRI.



CT imaging provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies and needle aspirations of many areas of the body, particularly the lungs, abdomen, pelvis and bones.



A diagnosis determined by CT scanning may eliminate the need for exploratory surgery and surgical biopsy.



No radiation remains in a patient's body after a CT examination.



X-rays used in CT scans usually have no side effects.

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Risks: 

There is always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk.



The effective radiation dose from this procedure ranges from approximately two to 10 mSv, which is about the same as the average person receives from background radiation in three to five years. See the Safety page for more information about radiation dose.



Women should always inform their physician and x-ray or CT technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.



CT scanning is, in general, not recommended for pregnant women unless medically necessary because of potential risk to the baby.



Nursing mothers should wait for 24 hours after contrast material injection before resuming breast-feeding.



The risk of serious allergic reaction to contrast materials that contain iodine is extremely rare, and radiology departments are well-equipped to deal with them.



Because children are more sensitive to radiation, they should have a CT study only if it is essential for making a diagnosis and should not have repeated CT studies unless absolutely necessary.

What are the limitations of CT Scanning of the Body Soft-tissue details in areas such as the brain, internal pelvic organs, ? knee or shoulder can be more readily and clearly seen with magnetic resonance imaging (MRI). The exam is not generally indicated for pregnant women. A person who is very large may not fit into the opening of a conventional CT scanner or may be over the weight limit for the moving table.

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