title: Diagnostic accuracy and sensitivity of diffusion-weighted and of gadoxetic acid-enhanced 3-T MR imaging alone or in combination in the detection of small liver metastasis (≤ 1.5 cm in diameter).
abstract: OBJECTIVE
  To compare the diagnostic accuracy and sensitivity of combined gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) with each imaging approach alone for detecting small hepatic metastases (≤ 1.5 cm).
  
  
  METHODS
  Institutional review board approved this retrospective study and waived informed patient consent. Eighty-six patients with 179 liver metastases underwent liver MRI including unenhanced and gadoxetic acid-enhanced imaging and DWI at 3.0 T. Three image sets including unenhanced images-gadoxetic acid set (early dynamic and hepatocyte phase), DWI set, and the combined set-were analyzed independently and in consensus by 2 observers for detecting liver metastases using receiver operating characteristic analysis.
  
  
  RESULTS
  There was a tendency toward an increased diagnostic accuracy for the combined set (mean, 0.965) compared with that for each image set alone (mean, 0.911 for gadoxetic acid set; 0.926 for DWI set). The combined set showed better sensitivity (mean, 97.47%/95.0%: values on per-lesion/per-patient basis) than each imaging set alone (mean, 90.7%/83.7% for gadoxetic acid set; 91.6%/83.0% for DWI set) (P < 0.05) on both per-lesion basis and per-patient basis. All image sets showed similar positive predictive values.
  
  
  CONCLUSIONS
  The combination of gadoxetic acid-enhanced MRI and DWI yielded better diagnostic accuracy and sensitivity in the detection of small liver metastasis than each magnetic resonance scan sequence alone.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Young Kon
authors.initials: YK
authors.lastname: Kim
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Seong Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Rhim
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lim
authors.forename: Dongil
authors.initials: D
authors.lastname: Choi
authors.forename: Young-sun
authors.initials: YS
authors.lastname: Kim
authors.forename: Kyung Mi
authors.initials: KM
authors.lastname: Jang
authors.forename: Soon Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Hyo Keun
authors.initials: HK
authors.lastname: Lim
mesh_terms: D016001:Confidence Intervals; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation*; D005240:Feasibility Studies; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA