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.
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.
Numminen
Kirsti
K
Department of Radiology, Helsinki University Central Hospital, Kasarmikatu 11, 00130 Helsinki, Finland. kirsti.numminen@hus.fi
Halavaara
Juha
J
Isoniemi
Helena
H
Tervahartiala
Pekka
P
Kivisaari
Leena
L
Numminen
Jussi
J
Höckerstedt
Krister
K
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