HEPATIC CAVERNOUS HEMANGIOMA - APPEARANCE ON T2-WEIGHTED FAST SPIN-ECHO MR-IMAGING WITH AND WITHOUT FAT-SUPPRESSION

OBJECTIVE. The goals of our study were to define the morphologic appea rance of cavernous hemangioma of the liver on T2-weighted fast spin-ec ho MR imaging and to determine if the use of fat suppression may quant itatively and qualitatively modify the MR imaging appearance of cavern ous hemangioma. SUBJECTS AND METHODS. Twenty-six patients with caverno us hemangiomas of the liver were prospectively studied with T2-weighte d MR imaging with a fast spin-echo technique with and without fat supp ression. Thirteen patients had known hemangiomas for more than 2 years , with no change in size or morphology during this period. The remaini ng 13 patients had diagnoses based on dynamic CT and sonography and an absence of change in the morphology and size of their lesions during follow-up of more than 6 months (range, 6-12 months) after the MR imag ing studies. Values for signal intensity and contrast-to-noise (CM) ra tios in cavernous hemangiomas that were obtained with and without fat suppression were compared. Images were qualitatively analyzed separate ly at identical level and window settings by two interpreters for morp hologic features of cavernous hemangiomas. RESULTS. No significant dif ference was found between signal intensity values obtained using the f at-suppressed fast spin-echo MR imaging technique (5.62 +/- 1.14 [SD]) and those obtained without fat suppression (5.51 +/- 1.23). Values fo r C/N ratios obtained with the fat-suppressed fast spin-echo MR imagin g technique (20.13 +/- 7.63) were significantly superior to those obta ined without fat suppression (16.59 +/- 5.31) (p < .001). On T2-weight ed fast spin-echo MR imaging without fat suppression, 100% of cavernou s hemangiomas were hyperintense relative to the spleen, 90% had well-d efined and sharp margins, 55% were isointense to CSF, and 76% were hom ogeneous. Without fat suppression, 34% of cavernous hemangiomas showed the combination of isointensity to CSF, well-defined margins, and hom ogeneity. On T2-weighted fast spin-echo MR imaging with fat suppressio n, all cavernous hemangiomas showed this same combination of features. CONCLUSION. Seventy-six percent of hepatic cavernous hemangiomas were homogeneous on T2-weighted fast spin-echo MR imaging, and 55% were is ointense to CSF. However, only 34% of hepatic cavernous hemangiomas sh owed typical features. Although fat suppression significantly increase d the C/N ratio of cavernous hemangiomas of the liver, fat suppression did not affect their morphologic appearance on T2-weighted fast spin- echo MR imaging.