Computerized Tomography-How Safe?

To the Editor. —Computerized tomography (CT) is undoubtedly one of the transcendental inventions in medicine. Its popularity derives from its superb resolution, specificity, and noninvasiveness. Coupled with contrast intensification, it has proved unequaled in the diagnosis of cerebrovascular disease. The technique is painless, results are readily available, and its cost is most competitive with other techniques capable of yielding similar information (ie, selective arteriography). The iodinated radiographic material infused when contrast is desired is the same used for intravenous pyelography, but the dosage is often higher. Therefore, the same potential complications, including acute oliguric renal failure, seen with any iodinated contrast medium1should be expected. During the past year, we have seen two diabetic patients with mild to moderate renal insufficiency in whom acute renal failure developed after CT scanning of the brain and contrast medium infusion. Both patients had had relatively stable renal function before the procedure, were and