This coronal (frontal view) gradient echo T2 MRI image demonstrates marked hyperintensity (looks black) of a cavernous malformation within the pons, which has also been called a cavernous angioma. This represents a slow flow type vascular malformation, which has also been referred to as an OCVM (occult vascular malformation) because they are generally angiographically invisible. These lesions represents dilated capillary spaces with no intervening normal brain. They can expand, however they are not usually associated with significant acute hemorrhages. The blood within these lesions results in marked magnetic susceptibility, which results in signal loss on the gradient echo technique making the lesion look black.