MRI Findings of Hemangioblastomas

ABSTRACT

PURPOSE: The purpose of this study is to evaluate the findings of magnetic resonance imaging(MRI) of posterior fossa hemangioblastoma and usefulness of contrast enhancement with Gd-DTPA. MATERIALS AND METHODS: Seven patients with posterior fossa hemangioblastoma were studied with both pre- and post-enhanced MRI. The MR images were reviewed regarding the location, size, signal intensities of cysts and mural nodules, and their contrast enhancement pattern. RESULTS: Five tumors were located in cerebellar hemisphere, one in vermis, and one in posterior part of medulla. One patient with von HippeI-Lindau disease had a medullary hemangioblastoma with multiple pancreatic cysts. In 6 cases, the major portion of the tumor was cysts and had small mulkal nodules. The solid portion was relatiely lange in one case, cemprising half of the tumor Cysts were oval shaped and their sizes were 3--6.7cm in diameter. In five cases(71%), septations were noted within the cysts. Cysts were isointense or slightly hyperintense on Tl-weighted image and hyperintense on T2-weighted image compared with cerebrospinal fluid. Mural nodules were oval or rounded appearance in five cases and flattened appearance in two, and their size was 0.5--2.5cm in diameter. Mural nodules were isointense to gray matter. They were detected in five cases on Tl-weighted images and one case on T2-weighted images. In two cases, vascular signal void area was noted in mural nodules. On contrast-enhanced Tl-weighted images, all mural nodules were intensely enhanced. CONCLUSION: MRI proved to be a good diagnostic method to detect and characterize posterior fossa hemangioblastoma. The most common finding is Cystic posterior fossa lesion with enhancing mural nodule. Contrast enhancement is essential for specific diagnosis.