title: The usefulness of (18)F-FDG PET/MRI fusion image in diagnosing pancreatic tumor: comparison with (18)F-FDG PET/CT.
abstract: OBJECTIVE
  This study aimed at demonstrating the feasibility of retrospectively fused (18)F FDG-PET and MRI (PET/MRI fusion image) in diagnosing pancreatic tumor, in particular differentiating malignant tumor from benign lesions. In addition, we evaluated additional findings characterizing pancreatic lesions by FDG-PET/MRI fusion image.
  
  
  METHODS
  We analyzed retrospectively 119 patients: 96 cancers and 23 benign lesions. FDG-PET/MRI fusion images (PET/T1 WI or PET/T2WI) were made by dedicated software using 1.5 Tesla (T) MRI image and FDG-PET images. These images were interpreted by two well-trained radiologists without knowledge of clinical information and compared with FDG-PET/CT images. We compared the differential diagnostic capability between PET/CT and FDG-PET/MRI fusion image. In addition, we evaluated additional findings such as tumor structure and tumor invasion.
  
  
  RESULTS
  FDG-PET/MRI fusion image significantly improved accuracy compared with that of PET/CT (96.6 vs. 86.6 %). As additional finding, dilatation of main pancreatic duct was noted in 65.9 % of solid types and in 22.6 % of cystic types, on PET/MRI-T2 fusion image. Similarly, encasement of adjacent vessels was noted in 43.1 % of solid types and in 6.5 % of cystic types. Particularly in cystic types, intra-tumor structures such as mural nodule (35.4 %) or intra-cystic septum (74.2 %) were detected additionally. Besides, PET/MRI-T2 fusion image could detect extra benign cystic lesions (9.1 % in solid type and 9.7 % in cystic type) that were not noted by PET/CT.
  
  
  CONCLUSIONS
  In diagnosing pancreatic lesions, FDG-PET/MRI fusion image was useful in differentiating pancreatic cancer from benign lesions. Furthermore, it was helpful in evaluating relationship between lesions and surrounding tissues as well as in detecting extra benign cysts.
authors.affiliation: Department of Radiology, School of Medicine, Miyazaki University, 5200 Kihara, Kiyotake, Miyazaki-city, Miyazaki Prefecture, 889-1692, Japan. snagama@med.miyazaki-u.ac.jp
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nagamachi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nishii
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Wakamatsu
authors.forename: Youichi
authors.initials: Y
authors.lastname: Mizutani
authors.forename: Shogo
authors.initials: S
authors.lastname: Kiyohara
authors.forename: Seigo
authors.initials: S
authors.lastname: Fujita
authors.forename: Shigemi
authors.initials: S
authors.lastname: Futami
authors.forename: Tatefumi
authors.initials: T
authors.lastname: Sakae
authors.forename: Eiji
authors.initials: E
authors.lastname: Furukoji
authors.forename: Shozo
authors.initials: S
authors.lastname: Tamura
authors.forename: Hideo
authors.initials: H
authors.lastname: Arita
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chijiiwa
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kawai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18