Brain death: MR and MR angiography.

Four patients in whom brain deaths was identified on the basis of neurologic and electroencephalographic findings were examined with MR imaging and MR angiography. MR images showed diffuse swelling of the cerebral gyri and cerebellar cortex, which prolongation of both the T1 and T2 signal (representing hypoxic ischemic brain injury), downward displacement of the diencephalon and the brain stem (central and tonsillar herniation), and loss of flow void in the intracranial portions of both internal carotid arteries. MR angiograms did not show the intracranial vessels above the level of the supraclinoid portion of the internal carotid arteries. MR angiography and MR imaging are noninvasive and reliable methods for use in determining brain death.