NEW YORK (Reuters Health), May 5 - The mean effective radiation dose for multislice computed tomography (MSCT) coronary angiography is significantly higher than that for conventional angiography, investigators from the U.K. report in the May 2nd issue of the Journal of the American College of Cardiology.
Dr. Duncan R. Coles and colleagues from the Bristol Heart Institute quantified and compared effective radiation doses from conventional coronary angiography and MSCT coronary angiography using a 16-slice scanner.
"Effective dose," they point out, "takes into account the amount of radiation absorbed in different organs and tissues, the relative biologic effectiveness of the radiation used, and the differing radiosensitivities of each organ and tissue."
One hundred eighty patients with suspected coronary artery disease underwent angiography using both modalities. The average age of study subjects was 63 years.
In a subset of 91 directly comparable patients, the researchers report that the mean effective dose for MSCT coronary angiography was 14.7 mSv and that for conventional angiography it was 5.6 mSv. The difference was significant.
They also make the point that an effective dose of 14.7 mSv carries a risk of inducing fatal cancer of 1 in 1,400, whereas an effective dose of 5.6 mSv carries a risk of 1 in 3,600.
"Coronary CT," the team notes, "gives a higher risk of cancer than conventional angiography, although it is without the invasive mortality and morbidity risks."
"As the clinical role of noninvasive CT coronary angiography develops," they conclude, "clinicians should remember that the use of ionizing radiation in medical exposures should be both justified and optimized."
Last Updated: 2006-05-04 15:46:36 -0400 (Reuters Health)
J Am Coll Cardiol 2006;47:1840-1845.
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