Radiation From Cardiac CT Scans Varies
Study Shows Many Centers Are Not Using Radiation-Lowering Strategies
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64-Slice CT Scan continued...
"We know the risk is low, but we don't know how low," he says.
Gerber emphasized that the wide variation of patient exposures in the study had little to do with technician error or carelessness.
And patient exposures at centers performing the most cardiac CT scans were not necessarily lower than exposure at centers performing fewer of the diagnostic tests.
One of the biggest dosage predictors was the use of strategies to lower radiation exposures to individual patients.
Only three-fourths of the centers participating in the study used a radiation-lowering strategy that has been shown to reduce exposure without affecting the efficacy of the scan. And other potentially more beneficial, but less well-studied, strategies have not been widely adopted.
Because the field is so new and it is so difficult to compare radiation doses of different centers, there is little that individual patients can do to minimize their exposure, short of avoiding redundant tests, Gerber says.
CT Scan Advisory
On Monday the American Heart Association issued an advisory to doctors in its journal Circulation, urging the judicious use of CT scans for the diagnosis of cardiovascular disease.
Gerber, who led the panel that wrote the advisory, says doctors need to carefully consider whether patients with chest pain or other symptoms consistent with heart disease will benefit from the test before ordering it.
The advisory also warns against using CT scans to screen asymptomatic patients who are at risk for cardiovascular disease.
"This is already happening, but there are no studies that show that screening asymptomatic patients and then changing their treatment based on the results impacts survival," he says.