title: Computed tomography angiogram: accuracy in renal surgery.
abstract: OBJECTIVE
  To determine the sensitivity and specificity of computed tomography angiogram (CTA) in detecting number and location of renal arteries and veins as well as crossing vessels causing uretero-pelvic junction obstruction (UPJO), and to determine if this can be used in decision-making algorithms for treatment of UPJO.
  
  
  METHODS
  A prospective study was carried out in patients undergoing open, laparoscopic and robotic renal surgery from April 2005 until October 2006. All patients were imaged using CTA with 1.25 collimation of arterial and venous phases. Each multi-detector CTA was then read by one radiologist and his results were compared prospectively with the actual intra-operative findings.
  
  
  RESULTS
  Overall, 118 patients were included. CTA had 93% sensitivity, 77% specificity and 90% overall accuracy for detecting a single renal artery, and 76% sensitivity, 92% specificity and 90% overall accuracy for detecting two or more renal arteries (Pearson chi(2) = 0.001). There was 95% sensitivity, 84% specificity and 85% overall accuracy for detecting the number of renal veins. CTA had 100% overall accuracy in detecting early dividing renal artery (defined as less than 1.5 cm branching from origin), and 83.3% sensitivity, specificity and overall accuracy in detecting crossing vessels at UPJ. The percentage of surgeons stating CTA to be helpful as pre-operative diagnostic tool was 85%.
  
  
  CONCLUSIONS
  Computed tomography angiogram is simple, quick and can provide an accurate pre-operative renal vascular anatomy in terms of number and location of renal vessels, early dividing renal arteries and crossing vessels at UPJ.
authors.affiliation: Department of Urology, King Khalid University Hospital, Department of Urology and Department of Renal Transplant at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. danny@surgical.net
authors.forename: Danny M
authors.initials: DM
authors.lastname: Rabah
authors.forename: Naif
authors.initials: N
authors.lastname: Al-Hathal
authors.forename: Turki
authors.initials: T
authors.lastname: Al-Fuhaid
authors.forename: Sayed
authors.initials: S
authors.lastname: Raza
authors.forename: Fahad
authors.initials: F
authors.lastname: Al-Yami
authors.forename: Waleed
authors.initials: W
authors.lastname: Al-Taweel
authors.forename: Mohamed
authors.initials: M
authors.lastname: Alomar
authors.forename: Nizar
authors.initials: N
authors.lastname: Al-Nagshabandi
mesh_terms: D000328:Adult; D000465:Algorithms; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D009392:Nephrectomy; D011446:Prospective Studies; D012077:Renal Artery / Q000000981:diagnostic imaging*; D012082:Renal Veins / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging; D055815:Young Adult