[Cerebellar infarcts that require differentiation from tumors: diagnosis with MRI].

It is often difficult to differentiate cerebellar infarct with cerebellar swelling from neoplastic disorders, because former can be shown as cerebellar mass with marked contrast enhancement on CT scan. We analyzed radiologically three cases with cerebellar infarction by using MRI, conventional CT scan and angiography. Two cases in the acute stage could be diagnosed as cerebellar infarction by MRI alone based on the following findings: 1) the lesion was distributed in the territory of cerebellar arteries; 2) the normal pattern of cerebellar folia and fissures was preserved in Gd enhancement MRI image; 3) characteristics of MRI intensity were compatible with hemorrhagic infarction. The other case in the chronic stage showed peculiar enhancement, which was unusual for infarction. It was diagnosed as cellular infarction with reference to the angiographic findings. MRI is generally useful to obtain early diagnosis of tumor-like cerebellar infarcts, and proper treatment should be started as early as possible.