title: Medial pathway patterns of the right retromesenteric plane: anatomical investigation using MDCT in patients with acute pancreatitis and pyelonephritis.
abstract: OBJECTIVE
  To investigate the medial pathways of the right retromesenteric plane by reviewing multidetector CT (MDCT) findings in patients with acute pancreatitis and pyelonephritis.
  
  
  METHODS
  112 patients with acute pancreatitis and 114 patients with pyelonephritis underwent MDCT scans. 64 of the 112 patients with acute pancreatitis and 34 of the 114 patients with pyelonephritis had right retromesenteric plane thickening because of inflammatory extensions. The medial pathways of the right retromesenteric plane were evaluated by two radiologists in consensus.
  
  
  RESULTS
  In 18 (28%) of the 64 patients with acute pancreatitis and 10 (29%) of the 34 patients with pyelonephritis, the right retromesenteric plane continued to the central retroperitoneum behind the descending duodenum and pancreatic head (Type 1 pathway). The right retromesenteric plane extended to the right wall of the descending duodenum (Type 2 pathway) in 46 patients (72%) with acute pancreatitis and 24 patients (71%) with pyelonephritis. There was no significant difference in the pathway patterns of the right retromesenteric plane between the acute pancreatitis group and the pyelonephritis group (Type 1 pathway, p = 0.89; Type 2 pathway, p = 0.76).
  
  
  CONCLUSIONS
  Two patterns were confirmed regarding the medial pathways of the right retromesenteric plane; this anatomical knowledge is important for evaluating the extension of retroperitoneal diseases.
  
  
  CONCLUSIONS
  Medial aspect of the right retromesenteric plane is thought to have two pathways. The right retromesenteric plane continuing to the right duodenal wall is a common type. Knowledge of these variations is important when evaluating the retroperitoneal diseases.
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Takaji
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Hiromu
authors.initials: H
authors.lastname: Mori
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Kiyonaga
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, Yufu, Japan.
authors.forename: Shunro
authors.initials: S
authors.lastname: Matsumoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008643:Mesentery / Q000000981:diagnostic imaging*; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D010179:Pancreas / Q000000981:diagnostic imaging; D010195:Pancreatitis / Q000150:complications / Q000000981:diagnostic imaging*; D011704:Pyelonephritis / Q000150:complications / Q000000981:diagnostic imaging*; D012187:Retroperitoneal Space / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D055815:Young Adult