Warning: Imaging Tests Can Damage Kidneys, Increase Stroke and Heart Attack Risk

Monday, July 20, 2009 by: S. L. Baker, features writer
Tags: imaging tests, health news, Natural News

(NaturalNews) No matter what your health complaint is, if you go see your doctor you might end up undergoing some kind of high tech imaging procedure such as cardiac angiography, CT (computed tomography) or MRI (magnetic resonance imaging). According to a study published last fall in the journal Health Affairs, medical imaging has soared over the last few years across all types of these tests, doubling the annual medical cost per patient. In fact, the study confirmed previous reports that patients are far-too-often being subjected to unnecessary imaging.

At least, most of these tests are minimally invasive and thoroughly studied to make sure they carry few risks so they are safe, right? Unfortunately, the answer is no. New reports of lasting, health-harming effects from some imaging tests are accumulating. A case in point: a new study just published in the Clinical Journal of the American Society Nephrology (CJASN) warns that seemingly minor and reversible kidney damage injury which can arise after undergoing certain common medical imaging procedures is a serious health threat. The reason? It is linked to a greatly increased risk of stroke, heart attack and death.

University of Vermont physician Richard Solomon,MD, and his colleagues investigated 294 patients with kidney disease who were exposed to contrast agents during cardiac angiography. Patients in this study, dubbed the CARE (Cardiac Angiography in REnally Impaired Patients) trial, were randomly divided with half receiving the contrast agent iopamidol and the other receiving the contrast agent iodixanol.

Many medical imaging techniques, including cardiac angiography and CT scans, often involve the use of contrast agents, substances that contain iodine (like iopamidol and iodixanol) and barium, because they enhance the contrast between body structures or fluids within the body. This allows blood vessels and changes in tissues to be more clearly visualized.

When Dr. Solomon and his colleagues followed the CARE patients for one year or longer, they found that 92 (31 percent) of the research subjects experienced negative health effects after their imaging test. Their risk of having a stroke or heart attack over the next year or two after the test was elevated. Overall, 38 (13 percent) of the patients experienced a major event, such as death, stroke, heart attack, or end-stage renal disease. Those who developed contrast-induced kidney injuries had twice as many long-term negative health effects compared with patients who didn't suffer kidney damage.

It isn't only people who already have problems with their kidneys who can be at risk from the imaging testing, either. Doctors have long known exposure to contrast agents can cause damage in seemingly healthy kidneys, but patients are usually assured this is just a temporary side effect that will resolve on its own. However, recent studies have suggested that contrast-induced kidney damage might actually be lasting and serious. In a statement to the media, the University of Vermont researchers said "the CARE trial findings should prompt investigators to design additional studies on the long-term negative health effects of contrast-induced kidney damage".

In addition to kidney damage, the contrast agent iopamidol has also been known to sometimes cause seizures in people with a history of epilepsy. In rare case reports, including one published earlier this year in the Internet Journal of Neurology, iopamidol has been found to cause severe seizures and respiratory arrest in non-epileptic patients undergoing imaging tests.

As reported in Natural News last April (https://www.naturalnews.com/026001.html), the use of contrast agents isn't the only potentially dangerous downside to some common imaging procedures. A study in the medical journal Radiology found that people who had numerous CT scans over their lifetime had a significantly increased risk of cancer. In fact, CT scans increased the risk of cancer by 2.7 to 12 percent.

For more information:
http://cjasn.asnjournals.org/
http://www.ispub.com/journal/the_internet_jo...
http://www.mayoclinic.com/health/drug-inform...