A prospective study of helical computed tomography angiography versus angiography for the detection of renal artery stenoses in hypertensive patients

Abstract

Objective. To compare helical computed tomography angiography with arterial digital subtraction angiography in the diagnosis of renal artery stenoses. Methods. Fifty hypertensives (24 men; mean age 53 years) were prospectively studied with computed tomography (Somaton Plus S, Siemens) and digital angiography (double-blind evaluation). Computed tomography was performed both in the sequential (the length of the abdomen) and in the helical (6 cm around renal arteries) modes during injection of 120 cm3 contrast medium. Results. Digital angiography visualized 16 significant (< 50% on quantitative angiography) stenoses (16/131 renal arteries, including 32 accessory), in 14 (28%) patients. On helical computed tomography, 16 stenoses were detected, in 49 patients (16/122 renal arteries, seven accessory arteries were not identified because they were located out side the scan area); two patients had false-positive helical computed tomography results. The computed tomography sensitivity, specificity, positive and negative predictive values were 87.5% (14/16), 98.2% (111/114), 87.5% and 98.2%, respectively. In the sequential mode, two cases of bilateral adrenal hyperplasia, two aortic aneurysms and one renal neoplasm were detected. None of these patients had renal artery stenosis. Conclusions. Helical computed tomography is a suitable new non-invasive diagnostic modality for the detection of renal artery stenosis or adrenal pathology. With continued development and evaluation computed tomography could prove useful as a screening tool or as a replacement for digital angiography in patients with possible secondary hypertension.