Living donor kidneys: usefulness of multi-detector row CT for comprehensive evaluation

To evaluate in living renal donors the usefulness of multi-detector row computed tomography (CT) in the assessment of renal vasculature and the upper urinary tract.

Four-channel multi-detector row CT scans were obtained in 77 patients. Vascular phase scans were used for CT angiography; excretory phase scans, for CT urography. At CT angiography, two independent observers evaluated the number of arteries and veins and the presence of early-branching arteries. CT urographic images were evaluated with regard to the opacification of the urinary tract and for abnormalities. Findings of CT angiography and urography were compared with surgical findings. Interobserver agreement between CT angiographic and surgical findings was quantified with weighted kappa statistics. Sensitivity and specificity of CT angiography in identifying supernumerary vessels and early-branching arteries were also evaluated. To evaluate the radiation dose to patients, weighted CT dose index (DI) was assessed for each scan.

Agreement between CT angiographic and surgical findings was excellent for the number of renal arteries (kappa = 0.896) and veins (kappa = 0.843). Detection rate of CT angiography was 98% (89 of 91) for arteries and 98% (83 of 85) for veins. The respective sensitivity and specificity of CT angiography were 86% (12 of 14) and 100% (65 of 65) for supernumerary arteries, 100% (11 of 11) and 100% (66 of 66) for early-branching arteries, and 75% (six of eight) and 100% (69 of 69) for supernumerary veins. At CT urography, collecting systems and proximal ureters were well opacified in all patients; two patients had underrotated kidneys without obstruction. The weighted CT DI was 10.19 mGy for unenhanced and excretory phase scans and 12.88 mGy for the vascular phase scan.

Multi-detector row CT can help assess well the renal vasculature and the urinary tract of living renal donors.