title: Clinicopathologic significance of high signal intensity on diffusion-weighted MR imaging in the ureter, urethra, prostate and bone of patients with bladder cancer.
abstract: OBJECTIVE
  The aim of this study was to determine the clinicopathologic significance of high-intensity areas in the ureter, urethra, prostate, and bone incidentally found on diffusion-weighted magnetic resonance imaging (DWI) for the staging of bladder cancer.
  
  
  METHODS
  Axial and sagittal DWI and T2-weighted imaging of the pelvis were evaluated in 157 patients with bladder cancer. Two observers assessed T2-weighted imaging with DWI independently. The observers pointed out 67 areas showing abnormal high signal intensity on DWI in the ureter (n = 17), urethra (n = 8), prostate (n = 20), and bone (n = 22). Of the 67 high-intensity areas, 33 lesions were confirmed histopathologically (ureter, n = 10; urethra, n = 7; prostate, n = 16), and 22 bone lesions were diagnosed using T1-weighted imaging and follow-up computed tomography. Thus, 55 lesions were evaluable for correlation with DWI findings.
  
  
  RESULTS
  Of the 55 high-intensity areas, 28 (53%) were synchronous or metastatic urothelial cancer or invasion of urothelial cancer. The remaining 27 (47%) were a ureteral clot in one, a ureteral stone granuloma in one, prostatic cancer in six, granulomatous prostatitis in three, and normal red bone marrow in 16.
  
  
  CONCLUSIONS
  DWI is useful to comprehend the extent of bladder cancer and to detect incidentally coexisting diseases. Other imaging, endoscopic, and clinical findings would be useful to reduce false positivity.
authors.affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya Aichi, 467-8601, Japan. m2rbimn@gmail.com
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sasaki
authors.forename: Masato
authors.initials: M
authors.lastname: Ito
authors.forename: Shuzo
authors.initials: S
authors.lastname: Hamamoto
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Kawai
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kohri
authors.forename: Masaki
authors.initials: M
authors.lastname: Hara
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000473:pathology / Q000556:secondary; D038524:Diffusion Magnetic Resonance Imaging; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007085:Ilium / Q000473:pathology*; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009378:Neoplasms, Multiple Primary / Q000473:pathology; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology / Q000556:secondary*; D012447:Sacrum / Q000473:pathology*; D014513:Ureter / Q000473:pathology*; D014516:Ureteral Neoplasms / Q000473:pathology / Q000556:secondary; D014521:Urethra / Q000473:pathology*; D014523:Urethral Neoplasms / Q000473:pathology / Q000556:secondary; D001749:Urinary Bladder Neoplasms / Q000473:pathology*