title: Magnetic resonance imaging of the liver: true fast imaging with steady state free precession sequence facilitates rapid and reliable distinction between hepatic hemangiomas and liver malignancies.
abstract: OBJECTIVE
  To assess the capability of the true fast imaging with steady state free precession (true FISP) sequence in the distinction between hemangiomas and malignant liver lesions.
  
  
  METHODS
  Sixty-eight patients with 45 hemangiomas and 51 liver malignancies were included in this study. A 1.5-T magnetic resonance system and a phased-array body coil were used. In addition to true FISP, breath-hold and fat-suppressed, T2-weighted, half-Fourier single-shot turbo spin echo (HASTE) and both unenhanced and gadolinium (Gd)-enhanced T1-weighted sequences were acquired. Two radiologists evaluated the magnetic resonance images independently in a blinded fashion. Interobserver variations with true FISP and HASTE were determined. Lesion contrast-to-noise ratios were calculated from true FISP images.
  
  
  RESULTS
  With true FISP, readers 1 and 2 made a correct distinction between hemangiomas and liver malignancies in 43 of 45 (96%) cases and 40 of 45 (89%) cases, respectively. The kappa value was 0.65. With HASTE, the success rates were 40 of 45 cases (89%) and 36 of 45 cases (80%), respectively, and the kappa value was 0.33. With a Gd-enhanced T1-weighted sequence, the correct classifications were 35 of 45 cases (78%) and 37 of 45 cases (82%), respectively. All hemangiomas appeared as bright and well-demarcated lesions on true FISP images. Malignant liver foci were heterogeneous with unsharp margins and nearly isointense relative to liver. The specificities of true FISP in lesion differentiation were 100% and 98% for readers 1 and 2, respectively. The mean contrast to noise ratio value of hemangiomas was 21.2 (standard deviation [SD] = 9.2), and that of malignant lesions was 4.9 (SD = 3.9). This difference was highly significant (P < 0.0001).
  
  
  CONCLUSIONS
  Noninvasive, rapid, and reliable differentiation between hemangiomas and malignant liver lesions is possible by using the true FISP sequence.
authors.affiliation: Department of Radiology, Helsinki University Central Hospital, Kasarmikatu 11, 00130 Helsinki, Finland. kirsti.numminen@hus.fi
authors.forename: Kirsti
authors.initials: K
authors.lastname: Numminen
authors.forename: Juha
authors.initials: J
authors.lastname: Halavaara
authors.forename: Helena
authors.initials: H
authors.lastname: Isoniemi
authors.forename: Pekka
authors.initials: P
authors.lastname: Tervahartiala
authors.forename: Leena
authors.initials: L
authors.lastname: Kivisaari
authors.forename: Jussi
authors.initials: J
authors.lastname: Numminen
authors.forename: Krister
authors.initials: K
authors.lastname: Höckerstedt
mesh_terms: D000328:Adult; D000368:Aged; D001331:Automation; D003937:Diagnosis, Differential; D005260:Female; D006391:Hemangioma / Q000175:diagnosis* / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity