title: Contrast-enhanced MR urography in the evaluation of renal transplants with urological complications.
abstract: OBJECTIVE
  The diagnostic work-up of renal transplants with impaired function due to urological problems can be difficult. This study was performed to assess sensitivity and specificity of non-invasive contrast-enhanced MR urography (MRU).
  
  
  METHODS
  Thirty-five patients with renal transplants (25 - 71 years, mean: 53.4 years) with sonographically diagnosed hydronephrosis or perirenal fluid collections were assessed by MR urography. MR examinations were carried out at a 1.5 T clinical scanner (Vision, Siemens, Erlangen, Germany) with a 512 matrix contrast-enhanced fat-suppressed T1-weighted FLASH 3D sequence in breath-hold technique. MIP reconstructions were used to produce MR urography. MRU diagnoses were compared to operative results.
  
  
  RESULTS
  In all patients, images with sufficient contrast in the renal collecting system were obtained. Hydronephrosis was confirmed in 20 patients, 8 patients showed a different pathology while 7 had normal findings. Compared to operative results, sensitivity of MRU was 100% with a specificity of 78%, respectively. One ureteral stone was misdiagnosed as a stricture, and 2 suspected ureteral stenoses could not be found upon operation.
  
  
  CONCLUSIONS
  Contrast-enhanced MR urography is a highly sensitive and specific non-invasive method to evaluate patients suspected of having typical post-transplant urological complications. It may replace invasive procedures such as antegrade pyelography in the pre-operative work-up.
authors.affiliation: Institute of Diagnostic Radiology, MNR-Klinik, Heinrich Heine University, Düsseldorf, Germany. cohnen@med.uni-duesseldorf.de
authors.forename: M
authors.initials: M
authors.lastname: Cohnen
authors.forename: M
authors.initials: M
authors.lastname: Brause
authors.forename: P
authors.initials: P
authors.lastname: May
authors.forename: G
authors.initials: G
authors.lastname: Hetzel
authors.forename: A
authors.initials: A
authors.lastname: Saleh
authors.forename: B
authors.initials: B
authors.lastname: Grabensee
authors.forename: U
authors.initials: U
authors.lastname: Mödder
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D004108:Dilatation, Pathologic / Q000175:diagnosis / Q000209:etiology; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D007089:Image Enhancement; D016030:Kidney Transplantation; D007685:Kidney Tubules, Collecting / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology; D012680:Sensitivity and Specificity; D013997:Time Factors; D014567:Urography / Q000379:methods; D014570:Urologic Diseases / Q000175:diagnosis* / Q000209:etiology*
chemical_list: D003287:Contrast Media