Diffusion-weighted MRI of haemangioblastomas and other cerebellar tumours.

We examined the signal intensity on diffusion-weighted imaging and the apparent diffusion coefficients (ADC) relative to normal cerebellum of the solid portions of 10 cerebellar haemangioblastomas and 12 other cerebellar tumours: three metastases, three medulloblastomas, three malignant lymphomas, an atypical teratoid rhabdoid tumour, an ependymoma and a subependymoma. The tumours were confirmed histopathologically except for one metastasis with pathological diagnosis of the primary lesion. In nine of the haemangioblatomas, the solid and contrast-enhancing portions gave low signal on DWI, but this was not seen in the other tumours. The ADC was increased in haemangioblastomas. These findings may indicate rich vascular spaces of the haemangioblastomas. DWI may be useful for distinguishing haemangioblastomas from other enhancing cerebellar tumours.