Figure 1

MRI/MRA of two patients diagnosed with clinical brain death.

a) The T2-weighted sagittal image shows tonsilar herniation due to global brain edema as one of the common findings in brain dead patients. The gadolinium-enhanced MR angiography showed no evidence for arterial blood flow in the intracranial circulation. b) The T1-weighted axial image shows diffuse gyral swelling, intraventricular hemorrhage and a fracture of the anterior skull resulting from severe traumatic head injury. The MRA showed no intracranial blood above the level of the proximal A2-segment of the ACA and the M1-segment of the MCA. c) The T2-weighted axial image depicts the situation after left-sided unilateral decompressive craniectomy showing a midline shift after massive hemispheric infarction due to vasospasm resulting from a subarachnoid hemorrhage. The MRA showed no evidence for cerebral blood flow while extracranial vessels exhibit normal circulation. d) The coronal T1-weighted image shows decompression after a hemorrhagic stroke affecting the right hemisphere. The MRA confirms the absence intracerebral arterial blood flow.