title: MRI findings of granulomatous prostatitis developing after intravesical Bacillus Calmette-Guérin therapy.
abstract: OBJECTIVE
  To evaluate magnetic resonance imaging (MRI) findings of granulomatous prostatitis (GP) developing after intravesical Bacillus Calmette-Guérin (BCG) therapy.
  
  
  METHODS
  Ten patients with pathologically proven GP underwent prostatic MRI. Lesion shape and signal intensity (SI) were evaluated on T2-weighted (T2WI), T1WI, and diffusion-weighted imaging (DWI).
  
  
  RESULTS
  Polygonal nodular lesions with notches, diffuse lesions, and cystic lesions with mural nodules were seen in two, six, and one patients, respectively. The remaining patient had a diffuse and cystic lesion. All diffuse lesions showed higher SI than muscle on T1WI and higher SI than the normal peripheral zone (PZ) on DWI. On T2WI, six of seven diffuse lesions showed a slightly lower SI than bone marrow and the remaining one lesion was iso-intense. All nodular lesions showed a low SI similar to muscle on T2WI and were iso-intense to muscle on T1WI. On DWI, two each of the four nodular lesions showed slightly lower SI and slightly higher SI than the normal PZ, respectively. All contents within the cyst and mural nodules showed markedly high and low SI on T2WI, respectively. On DWI, all fluids within cysts showed markedly high SI. One each of the mural nodules showed slightly higher SI and slightly lower SI than the normal PZ on DWI.
  
  
  CONCLUSIONS
  Three main MRI patterns of GP were identified: diffuse, nodular, and cystic with mural nodule; among them, the diffuse type was the most common. Cystic lesions with mural nodules could accompany the lesion.
authors: Department of Radiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya City, Japan. skamecrazy69@gmail.com
authors: T
authors: T
authors: Suzuki
authors: M
authors: M
authors: Takeuchi
authors: T
authors: T
authors: Naiki
authors: N
authors: N
authors: Kawai
authors: K
authors: K
authors: Kohri
authors: M
authors: M
authors: Hara
authors: Y
authors: Y
authors: Shibamoto
mesh_terms: D000283:Administration, Intravesical; D000368:Aged; D000369:Aged, 80 and over; D001500:BCG Vaccine / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D038524:Diffusion Magnetic Resonance Imaging; D006099:Granuloma / Q000139:chemically induced* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology; D011472:Prostatitis / Q000139:chemically induced* / Q000473:pathology; D012189:Retrospective Studies; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy*
chemical_list: D001500:BCG Vaccine