title: [Virtual endoscopy of the urinary tract from T(2)-weighted and gadolinium-enhanced T(1)-weighted MR urographic images].
abstract: OBJECTIVE
  To determine the diagnostic performance of T(2)-weighted (T2w) and gadolinium-enhanced T(1)-weighted (T1w-Gd-enhanced) MR urographic images for virtual endoscopy of the urinary tract.
  
  
  METHODS
  36 patients underwent MR urography at 1.5 T. In each patient a T2w (3D-TSE, respiration-triggered) and a T1w-Gd-enhanced sequence (T1-FFE, breathhold) were acquired. Data reconstruction was performed as maximum intensity projection (MIP) and virtual endoscopy (VE).
  
  
  RESULTS
  Combined analysis of MIP and VE delineated 32 of 36 pathologies; 86 % (19/22) of intraluminal pathologies could be depicted by VE and 15 % (3/22) by MIP (p </= 0.01). For the assessment of the renal pelvis, MIP was superior to VE in 55 % (39/71). Concerning the ureter, MIP was equal in 52 % (37/71) and superior to VE in 45 % (32/71). For virtual ureterorenoscopy both data sets were comparable in their diagnostic performance. T2w data sets were superior for virtual cystoscopy because no contrast medium is required in cases of renal failure and sedimentation artifacts can be avoided.
  
  
  CONCLUSIONS
  For the depiction of the upper urinary tract, MIP is in most cases equally good or superior to VE. However, virtual endoscopy of the urinary tract, especially virtual cystoscopy, is a useful tool for the depiction of intraluminal pathology.
authors.affiliation: Institut für Röntgendiagnostik, Urologische Klinik und Poliklinik, TU München, Klinikum rechts der Isar. beer@roe-med.tu-muenchen.de
authors.forename: A
authors.initials: A
authors.lastname: Beer
authors.forename: B
authors.initials: B
authors.lastname: Saar
authors.forename: T M
authors.initials: TM
authors.lastname: Link
authors.forename: M
authors.initials: M
authors.lastname: Settles
authors.forename: C
authors.initials: C
authors.lastname: Drews
authors.forename: H
authors.initials: H
authors.lastname: Schwaibold
authors.forename: E J
authors.initials: EJ
authors.lastname: Rummeny
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D004724:Endoscopy / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D014567:Urography / Q000379:methods*; D014570:Urologic Diseases / Q000175:diagnosis*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA