title: Multishot echo-planar imaging with gadopentetate dimeglumine. Preliminary study of efficacy for detection of hypovascular metastatic liver tumors.
abstract: OBJECTIVE
  To evaluate the usefulness of sequential T2-weighted spin-echo type multishot echo-planar (T2-EP) imaging with gadopentetate dimeglumine for the detection of hypovascular metastatic liver tumors.
  
  
  METHODS
  Fifteen consecutive patients with 56 proven hypovascular metastatic liver tumors were included in the study. Three observers blindly and independently read the whole-liver images obtained with T2-weighted spin-echo, T2-weighted single-shot fast spin-echo, T1-weighted fast multiplanar spoiled GRASS and T2-EP images obtained before and 25, 60, 90 and 120 s after injection of 0.2 mmol/kg b.w. of gadopentetate dimeglumine. The diagnostic accuracy was estimated by calculating the area under the observer-specific binomial receiver operating characteristics curves (Az).
  
  
  RESULTS
  T2-EP images obtained 60 s after contrast injection showed significantly higher contrast-to-noise (C/N) ratios than the other imaging techniques. A combination of all phases of the T2-EP images produced the highest sensitivity and specificity. In terms of the Az value, the diagnostic accuracy for tumor detection achieved with a combination of all phases of the T2-EP images was significantly higher than that with T1-SPGR and T2-SSFSE images (p<0.01). The Az values of the T2-EP images (Az=0.975) were higher than those of T2-CSE images (Az=0.948), but the difference was not significant.
  
  
  CONCLUSIONS
  Our preliminary study revealed that sequential imaging with enhanced T2-EP images was useful for the detection of hypovascular metastatic liver tumors because of its superior C/N ratio and sensitivity.
authors.affiliation: Department of Radiology, Osaka University Medical School, Suita-city, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: T
authors.initials: T
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Hori
authors.forename: M
authors.initials: M
authors.lastname: Takamura
authors.forename: K
authors.initials: K
authors.lastname: Tsuda
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Narumi
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D016477:Artifacts; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000379:methods*; D005189:False Positive Reactions; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007275:Injections, Intravenous; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D013997:Time Factors
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA