title: Focal liver lesions: characterization with conventional spin-echo versus fast spin-echo T2-weighted MR imaging.
abstract: OBJECTIVE
  To compare prospectively the diagnostic accuracy of T2-weighted conventional spin-echo (SE) and fast SE magnetic resonance (MR) imaging for differentiation of benign (hemangiomas or cysts) from malignant (metastases or hepatocellular carcinoma) liver lesions.
  
  
  METHODS
  Fifty-three patients with 55 confirmed liver lesions (20 hemangiomas, eight cysts, 22 metastases, four hepatocellular carcinomas, one malignant fibrous histiocytoma) underwent T2-weighted conventional SE (repetition time msec/echo time [TE] msec = 3,100/ 80,160) and fast SE (5,000-5,000/99-104 [effective TE]) MR imaging at 1.5 T. The images were evaluated quantitatively (lesion-liver signal intensity ratio and lesion T2 index [SIlesion TE80/SIlesion TE160, where SI = signal intensity] and qualitatively (blinded reading) by using receiver operating characteristic analysis.
  
  
  RESULTS
  Quantitatively, the T2 index (Az = .988) was more accurate than the signal intensity ratio at conventional SE (Az = .920) and fast SE (Az = .910) imaging (P < .05). Qualitatively, there was no statistically significant difference between the blinded reading of conventional SE (Az = .988) and fast SE (Az = .986) images in lesion characterization (benign vs malignant). There was a trend, however, toward superiority of conventional SE imaging for evaluation of "hypervascular" metastases (n = 9).
  
  
  CONCLUSIONS
  With the specific parameters used, conventional SE and fast SE images provide equal accuracy for characterization of focal liver lesions. In patients with hypervascular metastases, double-echo conventional SE images may be preferable.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, USA.
authors.forename: W
authors.initials: W
authors.lastname: Schima
authors.forename: S
authors.initials: S
authors.lastname: Saini
authors.forename: J A
authors.initials: JA
authors.lastname: Echeverri
authors.forename: P F
authors.initials: PF
authors.lastname: Hahn
authors.forename: M
authors.initials: M
authors.lastname: Harisinghani
authors.forename: P R
authors.initials: PR
authors.lastname: Mueller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003560:Cysts / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006391:Hemangioma / Q000175:diagnosis; D006801:Humans; D008099:Liver / Q000473:pathology; D008107:Liver Diseases / Q000175:diagnosis*; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity