title: Preoperative T staging of urinary bladder cancer: efficacy of stalk detection and diagnostic performance of diffusion-weighted imaging at 3T.
abstract: OBJECTIVE
  We evaluated the ability of diffusion-weighted imaging (DWI) at 3 tesla for diagnosing T stage and detecting stalks in bladder cancer.
  
  
  METHODS
  In total, 39 consecutive patients with bladder tumors underwent magnetic resonance (MR) imaging that included T2-weighted imaging (T2WI) and DWI using a 3T MR scanner. Two radiologists interpreted T2WI plus DWI and T2WI for diagnosis of T stage and for detection of stalks. We used McNemar's test to examine differences in diagnostic performance and Fisher's exact test to evaluate differences in stalk detection frequency.
  
  
  RESULTS
  Specificity and accuracy in differentiating T1 tumors from T2 to T4 tumors were significantly better with T2WI plus DWI (83% [20/24] and 85% [33/39]) than T2WI (50% [12/24] and 67% [26/39]; P = 0.02), and accuracy for diagnosing tumor stage was significantly better with T2WI plus DWI (82% [32/39]) than T2WI alone (59% [23/39]; P = 0.03). The observers identified stalks in 11 tumors by T2WI (48% [11/23]) and 17 by DWI (74% [17/23]) (P < 0.03).
  
  
  CONCLUSIONS
  DWI at 3T was superior to T2WI for evaluating the T stage of bladder cancer, particularly in differentiating T1 tumors from those T2 or higher, and in detecting stalks of papillary bladder tumors.
authors.affiliation: Department of Radiology, Showa University School of Medicine.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Ohgiya
authors.forename: Jumpei
authors.initials: J
authors.lastname: Suyama
authors.forename: Shoei
authors.initials: S
authors.lastname: Sai
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kawahara
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takeyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ohike
authors.forename: Hiroto
authors.initials: H
authors.lastname: Sasamori
authors.forename: Jiro
authors.initials: J
authors.lastname: Munechika
authors.forename: Makoto
authors.initials: M
authors.lastname: Saiki
authors.forename: Yui
authors.initials: Y
authors.lastname: Onoda
authors.forename: Masanori
authors.initials: M
authors.lastname: Hirose
authors.forename: Takehiko
authors.initials: T
authors.lastname: Gokan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D015588:Observer Variation; D011300:Preoperative Care / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D001743:Urinary Bladder / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000473:pathology*