title: Radiation-induced liver injury showing low intensity on T2-weighted images noted in Budd-Chiari syndrome.
abstract: OBJECTIVE
  Although it is documented that radiation can cause density or intensity changes on computed tomography or MR imaging in the irradiated hepatic parenchyma, few researchers have reported or understood the MR presentation of changes in hepatic parenchyma following radiotherapy in the patient with Budd-Chiari syndrome. The purpose of this study was to investigate the MR appearance of hepatic radiation injury in Budd-Chiari syndrome and to consider the underlying pathophysiology.
  
  
  METHODS
  The MR examinations of two patients with Budd-Chiari syndrome were compared with those of 11 patients without Budd-Chiari syndrome. The two groups, both of which suffered from hepatocellular carcinoma, underwent 50-72 Gy of proton-beam irradiation during a period of 14-43 days. Examinations including T1- and T2-weighted imaging, superparamagnetic iron oxide-enhanced imaging, and dynamic study were performed 3-10 weeks after the end of irradiation.
  
  
  RESULTS
  Radiation-induced hepatic injury was observed as a low-intensity area on T2-weighted images and on delayed phase images of dynamic study in the Budd-Chiari patients, and as iso- or high-intensity areas on both images in the patients without Budd-Chiari syndrome. US-guided needle biopsy from the irradiated area in one patient with Budd-Chiari syndrome revealed mostly necrotic tissue and fibrous tissue.
  
  
  CONCLUSIONS
  These MR features of hepatic radiation injury in Budd-Chiari syndrome were considered to be due to severe hepatic fibrosis.
authors.affiliation: Department of Radiology, Graduate School of Medicine, University of Tokyo, Japan.
authors.forename: Harushi
authors.initials: H
authors.lastname: Mori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshioka
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mori
authors.forename: Tayeb
authors.initials: T
authors.lastname: Ahmadi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Okumura
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Saida
authors.forename: Yuji
authors.initials: Y
authors.lastname: Itai
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D006502:Budd-Chiari Syndrome / Q000473:pathology* / Q000532:radiotherapy*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000473:pathology*; D012189:Retrospective Studies