 MRI brain: There are numerous punctate to small supratentorial and infratentorial areas of diffusion restriction with corresponding T2/FLAIR hyperintensity, with most centered in the bilateral cerebellar hemispheres posteriorly where there is effacement of sulci. There are foci of diffusion restriction in the central portion of the superior pons and cerebellar vermis. There are multiple small punctate punctate foci involving the bilateral parahippocampal gyri, left greater than right temporal and occipital lobes, bilateral parietal and frontal lobes. There is also involvement of the bilateral basal ganglia and right thalamus. There are innumerable punctate foci of susceptibility effect in the bilateral frontal, parietal and anterior temporal lobes, splenium of the corpus callosum, most of which do not definitively cross-reference with the areas of acute infarction. These are nonspecific and may represent chronic microhemorrhages.There is diffuse mild volume loss. There is mild periventricular white matter T2 signal abnormality which is nonspecific, likely representing chronic microvascular ischemic change. There is moderate left and trace right maxillary sinus mucosal thickening. There is mild to moderate ethmoid sinus and trace bilateral sphenoid mucosal thickening. There is left greater than right mastoid opacification. There is fluid in the posterior nasal cavity with a nasogastric tube partly imaged. The left V4 vertebral artery segment is diminutive with indistinct flow void.MRA brain: There is mild motion artifact degrading image quality. Within this limitation, the anterior and posterior circulation are intact with the exception of the left V4 vertebral artery segment which shows only minimal flow related enhancement and is much smaller compared to the right.MRA neck: The left subclavian artery origin is not well seen. The remaining great vessel origins are grossly intact. There is no flow related enhancement in the left subclavian artery approximately at the location of the expected left vertebral artery origin. The entire left vertebral artery is not seen except distally intracranially, compatible with occlusion with probable minimal retrograde flow. There is mild focal irregularity without significant stenosis at the origin of the right internal carotid artery suspected, best seen on the 3-D vessel images (series 505 image 13). There is mild asymmetric fullness of the left thyroid lobe with suspected decreased signal possibly representing a nodule (series 501 image 103).
1.Innumerable punctate to small acute foci of diffusion restriction in the supratentorial and infratentorial brain. Given recent history of cardiac arrest, these most likely represent numerous tiny infarcts which may be secondary cardiac embolic etiologies. Differential diagnosis also includes hypotension and/or hypoxic/anoxic injury, although the pattern seen on the study is atypical for these entities.2.Occlusion of the entire left vertebral artery with minimal retrograde flow intracranially, likely chronic.3.Occlusion of the left subclavian artery at the level of the expected left vertebral artery origin, extending distally, also likely chronic.4.Fullness and asymmetric decreased signal intensity in the left thyroid lobe suspicious for a thyroid nodule. Further dedicated thyroid sonogram can be helpful for further evaluation if clinically indicated.Findings were discussed with Dr. Ali Mansour over the telephone at 2:45 p.m. today by Dr. Uppuluri.