Multi-detector row CT evaluation of living renal donors prior to laparoscopic nephrectomy.

Since its introduction in 1995, laparoscopic nephrectomy has become the preferred technique at many medical centers for the harvesting of kidneys from living donors for transplantation. Because the field of view at laparoscopic surgery is limited, preoperative radiologic evaluation of the donor's anatomy---the renal veins and arteries, collecting system, and parenchyma--is critical. Spiral computed tomographic (CT) angiography is a fast, safe, minimally invasive, and generally accepted method for preoperative evaluation of the renal vessels. Multi-detector row CT scanners offer shorter image acquisition time, narrower collimation, better spatial resolution, and less tube heating than do single-detector row CT scanners. Multi-row scanners also provide more complete anatomic coverage, increased contrast enhancement of the arteries, and greater longitudinal spatial resolution--all of which are important both for accurate imaging of the renal vasculature and for three-dimensional postprocessing of image data. Dual-phase multi-detector row CT angiography combined with three-dimensional postprocessing enables minimally invasive and highly accurate depiction of the preoperative donor anatomy. To make the most effective use of this method, radiologists must be familiar with its technical aspects, advantages, and potential pitfalls. They also must be able to identify variations in vasculature and in renal and extrarenal anatomy that are important for laparoscopic donor nephrectomy.