Cerebral infarction due to embolism of left middle cerebral artery [I63.412], Reason for Study: ^Reason: evaluate penumbra, perform MRI brain with research protocol History: acute stroke from distal M1 occlusion, and right hemiparesis as result. There are multifocal restricted diffusion lesions involving left frontal lobe especially middle frontal gyrus and deep white matter of parietal and temporal lobes. There are also restricted diffusion lesions on the left external capsule and periventricular white matter. Constellation of above findings indicate both embolic and hemodynamic patterned acute ischemic infarction.On contrast enhanced scan, there are ill defined enhancement especially on the right superior frontal sulcus and adjacent to the left middle frontal gyrus which indicate contrast leakage due to blood brain barrier disruption or could represent parenchymal enhancement of acute/subacute ischemic tissue. There is no definitive evidence of hemorrhagic conversion.Underlying brain shows multifocal scattered FLAIR/T2 high signal intensities on bilateral periventricular white matter indicating non specific small vessel disease. The ventricles, sulci and cisterns are symmetric and unremarkable. The midline structures and cranial-cervical junction are normal. Normal flow voids are identified in the major intracranial vessels. The paranasal sinuses and mastoid air cells are clear.Brain perfusion imagingThe left MCA territory shows Increased MTT and Tmax comparing to that of right side.The left MCA rCBV shows significant increase and equivocal rCBF.Constellation of above findings indicate the left MCA territory is compensatory hypoperfusion status. In particular, the left frontal lobe especially middle frontal gyrus and deep white matter areas do not show increased rCBV with decreased rCBF, thus indicating ischemic tissue.
1. Acute ischemic infarctions on the left MCA territory.2. MR perfusion map shows the left MCA territory is overall compensatory hyperperfusion status with ischemic tissues on the left middle frontal gyrus and deep white matter.3. MR findings as well as perfusion map indicate the acute ischemic lesions are most likely combined embolic and hemodynamic in nature.