title: Detection of renal allograft rejection using blood oxygen level-dependent and diffusion weighted magnetic resonance imaging: a retrospective study.
abstract: BACKGROUND
  Acute rejection (AR) and acute tubular necrosis (ATN) are main causes of early renal allograft dysfunction. Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) and Diffusion weighted (DW) MRI can provide valuable information about changes of oxygen bioavailability and water diffusion by measuring R2* or apparent diffusion coefficient (ADC) respectively. We aimed to determine the value of BOLD MRI and DW MRI in detecting causes for early allograft dysfunction in renal allograft recipients.
  
  
  METHODS
  Fifty patients received renal allografts from deceased donors were analyzed, including 35 patients with normal renal function (control group), 10 AR patients and 5 ATN patients. Cortical R2* (CR2*) and medullary R2* (MR2*) were measured by BOLD MRI. Ten diffusion gradient b values (0, 5, 10, 20, 50, 100, 200, 400, 800, 1200s/mm2) were used in DW MRI. ADC values were measured in renal cortex (CADC) and medulla (MADC). CADCl and MADCl were measured under low b values (b ≤ 200 s/mm2), while CADCh and MADCh were measured under high b values (b > 200 s/mm2).
  
  
  RESULTS
  MR2* was significantly lower in AR group (18.2 ± 1.5/s) than control group (23.8 ± 5.0/s, p = 0.001) and ATN group (25.8 ± 5.0/s, p = 0.004). There was a tendency of lower levels on CADCl, MADCl, CADCh or MADCh in AR group than in control group. There were no differences on ADC values between AR group and ATN group.
  
  
  CONCLUSIONS
  BOLD MRI was a valuable method in detection of renal allografts with acute rejection.
authors.forename: Guangyi
authors.initials: G
authors.lastname: Liu
authors.affiliation: Kidney Disease Center, First Affiliated Hospital, College of Medicine, Zhejiang University; Key Laboratory of Kidney Disease Prevention and Control Technology, Zhejiang Province; The Third Grade Laboratory under the National State Administration of Traditional Chinese Medicine, Hangzhou, China. hanf8876@gmail.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Han
authors.forename: Wenbo
authors.initials: W
authors.lastname: Xiao
authors.forename: Qidong
authors.initials: Q
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Jianghua
authors.initials: J
authors.lastname: Chen
mesh_terms: D064591:Allografts; D038524:Diffusion Magnetic Resonance Imaging; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000175:diagnosis* / Q000473:pathology / Q000517:prevention & control; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D016030:Kidney Transplantation; D007683:Kidney Tubular Necrosis, Acute / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood; D012189:Retrospective Studies
chemical_list: D007166:Immunosuppressive Agents; D010100:Oxygen