| The most serious problem with the widespread | | | | which you can assume you're safe. Of course, |
| use of CAT scans is the radiation these devices | | | | everyone is different and no one will be affected |
| leave in our bodies. CAT scans are not simple | | | | by radiation in the same way. And when we talk |
| chest X-rays, which deliver only a small amount | | | | about the radiation doses for various medical |
| of radiation. Instead, they expose the patient to a | | | | procedures, we are always talking about |
| significant amount of radiation, and radiation in | | | | estimates rather than exact figures. Depending on |
| significant doses has been shown to increase the | | | | where you have your CAT scan done, who is |
| risk of cancer. | | | | performing it, what machine is being used, and |
| We are all exposed to "natural background | | | | what condition is being screened for, the doses |
| radiation" -- that is, radiation from the sun, radon | | | | can vary. But radiation interferes with the body's |
| gas, rocks in the ground, cosmic rays, and other | | | | natural immune system the same way regardless |
| sources that usually can't be avoided in our daily | | | | of dose. Your body keeps you healthy by |
| lives. Radiation is measured in units called | | | | attacking free radicals, scavengers, and cancer |
| "millisieverts" (mSv), and we can use millisieverts | | | | cells inside you, but its resources are finite. A |
| to compare this natural radiation to the levels of | | | | sudden blast of radiation can be just the impetus |
| radiation we get from other sources, such as | | | | needed to allow leukemia, breast cancer, or some |
| medical tests. For instance, a chest X-ray | | | | other cancer to begin developing. |
| provides about 0.02 mSv, or the equivalent of 2.4 | | | | Cost |
| days of natural background radiation. A CAT scan | | | | When CAT scan machines were first widely |
| of the abdomen, on the other hand, provides | | | | introduced in the early 1980s, they were heavily |
| about 10.0 m5v, or the equivalent of 500 chest | | | | publicized and marketed. Because the scans were |
| X-rays or 3.3 years of natural background | | | | normally not covered by insurance, the cost was |
| radiation. And a 64-slice wholebody CAT scan | | | | all out-of-pocket for the patient. So a lot of |
| provides 15.2 m5v for men and 21.4 mSv for | | | | people, especially those who had cause to be |
| women (women's denser body tissue and breasts | | | | worried about potential health risks due to family |
| require higher doses to get clear images) -- quite | | | | history, put thousands of dollars on the table -- |
| a difference, especially when you realize that the | | | | even if they couldn't afford it -- all because they |
| radiation you receive is cumulative. | | | | and their families believed the tests would "save |
| Now compare these numbers with the level of | | | | their lives" by revealing hidden life-threatening |
| radiation to which Japanese survivors of the | | | | conditions. Some of my own patients told me |
| atomic bomb explosions at Hiroshima and | | | | that imaging centers had charged them up to |
| Nagasaki were exposed: an average dose of | | | | $2,500 for a single scan; other patients have |
| between 5 and 20 mSv, with some doses as high | | | | reported paying anywhere from $500 to $5,000. |
| as 50 mSv. A single CAT scan can easily exceed | | | | And many of these centers were not run by |
| that average. And since radiation from all sources | | | | doctors but by business people who were very |
| remains in our bodies for life, the likelihood of the | | | | aggressive in their marketing. |
| average twenty-first-century patient matching or | | | | Hospitals, doctors, and scanning centers had |
| exceeding that average, even without a CAT | | | | invested several million dollars in each one of |
| scan, is very high. In the New York Times, Roni | | | | these scanners, and naturally they wanted to |
| Caryn Rabin reported that recent studies indicate | | | | recoup their costs. So there was a lot of |
| that the amount of radiation in the bodies of | | | | pressure put on patients to have CAT scans |
| Americans increased 600 percent between 1980 | | | | when they may not have needed them and a lot |
| and 2006, with the bulk of this increase attributed | | | | of marketing done to doctors about how they |
| to diagnostic imaging procedures. In 1980 about 3 | | | | could double their income by using these machines |
| million of these procedures were performed, but | | | | in their practices. The dangers were being |
| by 2006 the number had skyrocketed to 62 | | | | completely ignored. Unfortunately, this is still largely |
| million. If you were to follow some popular | | | | the case. |
| recommendations to have an animal CAT scan, | | | | Effectiveness |
| plus one virtual colonoscopy and a coronary | | | | Here's what most people do not realize: there is |
| angiogram (both of which also deliver large doses | | | | absolutely no data to prove that CAT scans are |
| of radiation), in the space of only a few years | | | | medically useful for people who do not have any |
| you could easily be exposed to more radiation | | | | symptoms. According to the FDA website: |
| than even the most highly exposed Hiroshima | | | | The FDA has never approved CT for screening |
| survivor. | | | | any part of the body for any specific disease, let |
| The World Health Organization, Centers for | | | | alone for screening the whole body when there |
| Disease Control and Prevention, and the National | | | | are no specific symptoms of disease at all. No |
| Institute of Environmental Health Sciences have all | | | | manufacturer has submitted data to FDA to |
| classified X-rays as carcinogens based on the fact | | | | support the safety and efficacy of screening |
| that they have been linked to leukemia and | | | | claims for whole-body CT screening. |
| cancers of the breast, lungs, and thyroid. The risk | | | | They further state:the FDA knows of no data |
| of a fatal cancer from a chest X-ray has been | | | | demonstrating that whole-body CT screening is |
| estimated as one in a million or morein other | | | | effective in detecting any particular disease early |
| words, very remote. But the risk of a fatal | | | | enough for the disease to be managed, treated, |
| cancer in a person who has had just one of these | | | | or cured and advantageously spare a person at |
| new 64-slice CAT scans is estimated to be one in | | | | least some of the detriment associated with |
| 2,000. In one study reported in the Journal of the | | | | serious illness or premature death. |
| American Medical Association, the risk of cancer in | | | | In addition, the American College of Radiology, the |
| people having 64-slice CAT scans of the heart | | | | American College of Cardiology/American Heart |
| was found to be greater for young women than | | | | Association, the American Association of |
| young men. Researchers found that one of every | | | | Physicists in Medicine, and the American Medical |
| 143 women scanned at age twenty will develop | | | | Association, among others, do not recommend |
| cancer, usually breast cancer; the risk for | | | | CAT scans. Medicare and most insurance |
| forty-year-old women falls to one in 284. For | | | | companies do not cover CAT scans for screening |
| men, the cancer risk was one in 686 for a | | | | because the tests have never been shown to |
| twenty-year-old, and one in 1,007 for a | | | | provide information in addition to what we can |
| forty-year-old. The reason for the gender | | | | already learn through doing a medical history, a |
| difference in risk lies in the fact that breast tissue | | | | physical exam, and blood tests. |
| is very sensitive to radiation and the heart can't | | | | The above is an excerpt from the book The |
| be scanned without radiation exposure to breast | | | | Great American Heart Hoaxby Michael Ozner, |
| tissue. Clearly, administering CAT scans simply for | | | | MD, FACC, FAHA |
| screening is a risk we shouldn't be recommending | | | | Published by BenBella Books; December |
| people take. | | | | 2008;$24.95US/$27. |
| There is no level of radiation exposure below | | | | |