Living Donor Kidneys: Usefulness of 16-Slice Multi-Detector Row; CT for Preoperative Evaluation

Purpose: To assess in living renal donors the accuracy of 16-slice multi-detector row CT (MDCT) in the evaluation of renal vasculature and the upper urinary tract by using surgery as the reference standard.Material and Methods: This study was approved by our institutional review board for human investigation. 63 consecutive potential kidney donors (38 men and 25 women; mean age, 40.7 years) underwent 16-channel MDCT. Unenhanced CT of the abdomen was performed. Next, 100mL of nonionic contrast material was injected at a rate of 4-5mL/sec. Arterial, nephrographic and excretory phase volumetric data sets were acquired at 20-25 seconds, 70-75 seconds, and 10 min after start of injection respectively. Volumetric reconstructions were performed at a CT workstation for the 1mm sections of the arterial and nephrographic phases. These included coronal and oblique coronal overlapping thin MIP as well as 3D MIP reconstructions parallel to the renal hilar vessels. CT urographic images were reconstructed from the excretory phase CT data in the coronal or oblique coronal plane by using MIP. Each scan was evaluated independently for renal vascular and ureteral anatomic variants. Findings at CT were compared with those at surgery. Sensitivity, specificity and accuracy of MDCT were calculated on the basis of presence or absence of variant anatomy at surgery. Results: CT depicted 76 of 77 renal arteries confirmed at surgery, one accessory artery was misinterpreted at CT as early branching artery. CT depicted 66 of 67 renal veins confirmed at surgery. Overall accuracy of CT was 98.4%, 98.4% and 100% for identification of variant anatomy of renalarteries, veins and ureters, respectively.Conclusion: 16-channel MDCT used as the sole minimally invasive imaging technique in the comprehensive evaluation of living renal donor candidates provides high accuracy for detecting renovascular and ureteric anomalies.