title: Is rectal MRI beneficial for determining the location of rectal cancer with respect to the peritoneal reflection?
abstract: BACKGROUND
  An objective method for determining the location of the cancer with respect to peritoneal reflection would be helpful to decide the treatment modality for rectal cancer. This study was designed to evaluate the accuracy and usefulness of rectal MRI to determine spatial relations between the peritoneal reflection and rectal cancer and to compare these with operative findings.
  
  
  METHODS
  Patients that underwent a rectal cancer operation after a rectal MRI check between November 2008 and June 2010 were considered for the study. The patients that received preoperative concurrent chemoradiation or trans-anal local excision were excluded.
  
  
  RESULTS
  Fifty-four patients constituted the study cohort. By comparing surgical and radiologic findings, the accuracy for predicting tumour location in relation to the peritoneal reflection by rectal MRI in all patients was 90.7%. In terms of tumour location in relation to peritoneal reflection, the accuracy of rectal MRI was 93.5% in patients with a tumour located above the peritoneal reflection, 90.0% in patients with a tumour located on the peritoneal reflection, and 84.6% in patients with a tumour located below the peritoneal reflection (p=0.061). When the cohort was subdivided by gender, body mass index (BMI), operative findings, or tumour size, no significant difference was observed among subgroups.
  
  
  CONCLUSIONS
  Rectal MRI could be a useful tool for evaluating the relation between rectal cancer and peritoneal reflection especially when tumour size is less than 8cm. Rectal MRI can provide information regarding the location of rectal cancer in relation to the peritoneal reflection for treatment planning purposes.
authors: Department of Surgery, Colorectal Cancer Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea.
authors: Eun Joo
authors: EJ
authors: Jung
authors: Chun Geun
authors: CG
authors: Ryu
authors: Gangmi
authors: G
authors: Kim
authors: Su Ran
authors: SR
authors: Kim
authors: Sang Eun
authors: SE
authors: Nam
authors: Hee Sun
authors: HS
authors: Park
authors: Young Jun
authors: YJ
authors: Kim
authors: Dae-Yong
authors: DY
authors: Hwang
keywords: magnetic resonance imaging (MRI); peritoneal reflection; rectal cancer