Presentation
Stroke code - acute left sided weakness
Patient Data
Plain CT appears normal. The perfusion parameters show raised MTT/TTP with low CBF, but preserved CBV in the right internal capsule posterior limb/thalamus, consistent with penumbra. Note that the MTT/CBV fusion map does not demonstrate these findings showing the importance of reviewing the perfusion maps. The patient was thrombolysed shortly after the scan.
MRI shows sub-acute infarct in the abnormal region on CT perfusion.
Case Discussion
CT perfusion maps have low resolution and small infarcts can be easily missed. Also, it can be difficult to determine if a small area of abnormal perfusion represents artefact or infarct. However, as this case demonstrates, small infarcts can be seen with modern machines and software (also, there was good correlation between imaging findings and patient symptoms).