Wednesday, August 30, 2006

HOW SAFE IS YOUR CT SCAN?

Risk of radiation during CT scans:
CT scans have become commonplace and are an essential part of investigations,
that the consultant/ doctor advises, today. However, have CT scans been taken for granted, as truly safe for the patient?

Recent studies done (http://www.fda.gov/cdrh/ct/risks.html ) in USA and Europe suggest that there is a small but significant risk of radiation induced cancer, occurring due to
CT scans. These conclusions have been made after the release of the BEIR VII report
( BEIR VII Press Release: Low Levels of Radiation May Cause Harm ).
According to the report, the National Academy of Sciences, has described a 1-in-1000 chance of developing cancer from a single radiation exposure of 10 mSv.
(mSv is a unit of measuring the amount of radiation a person receives).
10 mSv is the amount of radiation a patient receives during a single CT scan study of the
abdomen, chest or the pelvis. The study also finds that the risk in children is even
higher. 1 in every 550 children scanned would develop cancer due to the CT scan.
The recommendations of the study are that persons under 40 yrs. age should be carefully
screened to avoid unnecessary scans. This is specially true whilst scans involve the gonads.
A CT scan of the head exposes you to about 2 mSv, a scan of the chest is about 8 mSv, and a study of the abdomen and pelvis is about 10 mSv. A normal person is
exposed to 3 to 5 mSv of radiation every year (ie: radiation from soil and atmosphere).
The real problem arises when a person (especially those under 40 and children) are
subjected to repeated scans, with doses exceeding 50 mSv.

Conclusion: Be judicious in the use of CT scans. Though there are definite risks
involved in repeated scans, they are to be carefully weighed against the numerous diagnostic benefits this tool provides.