Helical CT evaluation of potential kidney donors: findings in 154 subjects

The purpose of our study was to assess renal helical CT (RHCT) as the primary imaging technique in the evaluation of potential kidney donors. Unenhanced and enhanced (3-mm collimation) RHCT was performed in 154 kidney donors using 125-150 ml of i.v. contrast material at an injection rate of 3 or 4 ml/sec and a pitch of 1.3-2. Scans were reconstructed at 1.5-mm intervals for a three-dimensional image. RHCT images were compared with the results of renal arteriography (RA) (50 subjects) and surgery (117 subjects). CT and surgical findings agreed in 95% of patients (111/117), with five cases of missed accessory arteries (all < 2 mm in diameter) and one case of a missed early division of the main artery. In the 50 subjects who underwent CT and RA, imaging revealed concordance in 96% of 100 kidneys. One small accessory artery was not detected by CT (origin from the common iliac artery). RA did not detect accessory arteries in three subjects. All 22 kidneys with early dividing main arteries (< 1.5 cm from the aortic origin) were identified by both RHCT and RA. Axial and three-dimensional CT images were complementary: five small accessory arteries were seen well only on the axial sections, whereas four early dividing arteries and two cases of renal artery stenosis were prospectively identified only on the three-dimensional images. Twenty-five renal vein anomalies were detected only by CT. In the full series of 154 subjects, nonvascular renal findings included renal calculi (n = 11), cysts (n = 12), duplicated ureters (n = 6), horseshoe kidney (n = 1), and pelvic kidney (n = 1). RHCT can be the primary imaging technique in the assessment of potential kidney donors, reducing the number of examinations as well as the risk and cost of imaging in these subjects.