Peripherally enhancing lesion within the right basal ganglia with associated abnormal diffusion restriction. In addition, cortically based T2/FLAIR hyperintensity and abnormal diffusion restriction involving the right frontal, parietal and temporal gyri, extending into the right cerebral peduncle are also present. These demonstrate gyral enhancement post-contrast. Occluded right middle cerebral artery on MRA (obtained the following day) - on the initial study there appeared to be preserved flow voids on T2.
Conclusion:
The appearances are most in keeping with a subacute MCA territory infarct. It is possible that this represents a basal ganglia abscess with secondary M1 arteritis and distal artery-to-artery embolism although the lack of significant leptomeningeal enhancement around the artery makes this less likely. It is also possible that this was an embolic stroke with subsequent superimposed infection (e.g. from bacterial endocarditis).
Regardless of the microbiology of the aspirate, this requires stroke workup and an echo of the heart is recommended.