Health Tests

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Risks from this test are minimal. A few people have an allergic reaction to the dye used in the test. Some people have a headache or back soreness for a short time.

As with x-rays, there is a small exposure to radiation. In large amounts, exposure to radiation can cause cancers or (in pregnant women) birth defects. The amount of radiation from a CT scan is larger than from regular x-rays, but still very small—too small to be likely to cause any harm.

From Health A-Z, Harvard Health Publications. Copyright 2007 by the President and Fellows of Harvard College. All rights reserved. Written permission is required to reproduce, in any manner, in whole or in part, the material contained herein. To make a reprint request, contact Harvard Health Publications. Used with permission of StayWell.

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