title: Diffusion-weighted magnetic resonance imaging to differentiate malignant from benign gallbladder disorders.
abstract: OBJECTIVE
  To retrospectively evaluate the utility of apparent diffusion coefficient (ADC) and lesion to spinal cord ratio (LSR) in diffusion-weighted magnetic resonance (MR) imaging (DWI) as compared with morphological assessment alone, for differentiating malignant from benign gallbladder disorders.
  
  
  METHODS
  This study was approved by the ethics committee, and written informed consent was waived. Ninety-one patients (13 malignancy and 78 benignancy) were reviewed. ADC was calculated using two DW images with different motion-probing gradient strengths (b=0, 1000s/mm(2)). LSR was measured by dividing the signal intensity of a thickened gallbladder wall by the maximum signal intensity of the lumbar enlargement of the spinal cord. In addition, the morphology of the gallbladders was assessed with conventional MR imaging.
  
  
  RESULTS
  In receiver operating characteristic curve analysis, the areas under the curves for ADC and LSR were 0.861 and 0.906, respectively. Three morphological findings were considered: a massive formation, a disrupted mucosal line, and the absence of a two-layered pattern. When a combination of two or more of these morphological findings was positive for malignancy, the sensitivity, specificity, and accuracy were 76.9%, 84.0%, and 83.0%, respectively. When a combination of three or more of the above morphological findings together with ADC of less than 1.2 × 10(-3)mm(2)/s or LSR of more than 0.48 were positive for malignancy, these values were 73.0%, 96.2%, and 92.9%, respectively. There were significant differences in specificity and accuracy.
  
  
  CONCLUSIONS
  Use of ADC and LSR in DWI can improve diagnostic performance for differentiating malignant from benign gallbladder disorders.
authors.affiliation: Department of Radiology, Tokyo Medical and Dental University, 1-5-45 Yushima Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kitazume
authors.affiliation: Department of Radiology, Ome Municipal General Hospital, 4-16-5, Higashi-Ome, Ome City, Tokyo 198-0042, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Taura
authors.affiliation: Department of Radiology, Ome Municipal General Hospital, 4-16-5, Higashi-Ome, Ome City, Tokyo 198-0042, Japan.
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Nakaminato
authors.affiliation: Department of Gastroenterology, Ome Municipal General Hospital, 4-16-5, Higashi-Ome, Ome City, Tokyo 198-0042, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Noguchi
authors.affiliation: Department of Surgery, Ome Municipal General Hospital, 4-16-5, Higashi-Ome, Ome City, Tokyo 198-0042, Japan.
authors.forename: Yukiyoshi
authors.initials: Y
authors.lastname: Masaki
authors.affiliation: Department of Pathology, Ome Municipal General Hospital, 4-16-5, Higashi-Ome, Ome City, Tokyo 198-0042, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kasahara
authors.affiliation: Department of Radiology, Tokyo Medical and Dental University, 1-5-45 Yushima Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Kishino
authors.affiliation: Department of Radiology, Tokyo Medical and Dental University, 1-5-45 Yushima Bunkyo-ku, Tokyo 113-8519, Japan. Electronic address: ttisdrnm@tmd.ac.jp.
authors.forename: Ukihide
authors.initials: U
authors.lastname: Tateishi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D002277:Carcinoma / Q000175:diagnosis; D002764:Cholecystitis / Q000175:diagnosis; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D005704:Gallbladder / Q000473:pathology; D005705:Gallbladder Diseases / Q000175:diagnosis*; D005706:Gallbladder Neoplasms / Q000175:diagnosis*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods / Q000706:statistics & numerical data; D008159:Lumbar Vertebrae / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011127:Polyps / Q000175:diagnosis; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013116:Spinal Cord / Q000473:pathology
keywords: Apparent diffusion coefficient; Diffusion-weighted imaging; Gallbladder; Gallbladder carcinoma