1 JOURNAL OF ENDOUROLOGY Volume 22, Number 1, January 2008 © Mary Ann Liebert, Inc. DOI: 10.1089/end.2006.9857 Vascular Renal Anatomy and the Ureteropelvic Junction: Preoperative Multidetector CT Scanning with Split-Bolus Injection as a Predictor of Laparoscopic Findings* BENOIT SAUER, M.D., 1 MURIEL FLOCQUET, M.D., 1 TOUFIK BATCH, M.D., 1 ALAIN BLUM, M.D., Ph.D., 1 and JACQUES HUBERT, M.D., Ph.D. 2 ABSTRACT Purpose: To compare multidetector CT scan (MDCT) results with intraoperative findings in the detection of an inferior-pole pedicle crossing the ureteropelvic junction. Patients and Methods: Over the 2-year study period, 35 patients receiving laparoscopic pyeloplasty under- went preoperative investigation with a novel MDCT protocol in order to detect crossing vessels. Postprocess- ing, including maximum intensity projection, volume-rendering technique, and multiplanar reconstruction, was used in addition to standard axial views. Results: All the arteries found during laparoscopic surgery were detected by MDCT, but one radiologic false-positive was noted at the beginning of the series. Seven veins were not detected with MDCT. In the only case featuring an isolated inferior-pole vein, the aberrant vessel was identified by MDCT. Conclusion: Multidetector CT scanning is a highly accurate way of providing all the information necessary preoperatively concerning renal parenchymal anomalies, urinary stones, and collecting system and vessel anat- omy. It helps physicians make appropriate therapeutic decisions and gives surgeons information about what they can expect during laparoscopic procedures. INTRODUCTION P REOPERATIVE INFORMATION about a patient’s renal anatomy is likely to reduce the risk of problems during lap- aroscopy for ureteropelvic junction (UPJ) obstruction. Detec- tion of an inferior-pole vessel (which may cause failure or he- morrhagic complications during endopyelotomy) would be particularly helpful in ensuring appropriate medical and surgi- cal intervention. The purpose of this study was to determine whether the find- ings of a multidetector CT scan (MDCT) would facilitate sur- gical management of patients with symptomatic UPJ obstruc- tion. Specifically, we assessed prospectively the ability of preoperative MDCT to detect an inferior-pole vessel crossing the UPJ. PATIENTS AND METHODS Between November 2001 and September 2003, 35 patients (mean age 40 years; range 18–77 years) scheduled for laparo- scopic robot-assisted pyeloplasty were examined preoperatively for a crossing vessel using multiphasic MDCT (16 rows, Sen- sation 16 ® , Siemens, Erlangen, Germany). Multidetector CT was conducted in three steps: a nonenhanced scan followed by administration of 60 mL of iodinated contrast medium (iodix- anol [Vispaque ® 320]; Amersham Health SA) and then imme- diate intravenous injection of a diuretic (furosemide 80 mg). Ten minutes later, CT acquisitions were obtained in the arter- ial phase (30 seconds after the start of a second injection of the same contrast medium) and the venous (nephrographic) phase (100 seconds after the second injection of contrast medium). 1 Service d’imagerie Guilloz, Hôpital central, CHU Nancy, France. 2 Service d’urologie, Hôpitaux de Brabois, CHU Nancy. * Entry in the 2006 Endourological Society Clinical Essay Competition.