Delayed reflow of an ischemic infarct after spontaneous thrombolysis studied by CBF tomography using SPECT and Tc-99m HMPAO

A patient with a large ischemic infarct in the left middle cerebral artery territory was studied six times in the acute/subacute phase by cerebral blood flow (CBF) tomography using Tc-99m-HMPAO. The SPECT instrument used was a brain dedicated highly sensitive four-camera system (TOMOMATIC 232) that allows to keep the radioactivity dose per study at 10 mCi (370 MBq). Transcranial Doppler and angiography showed spontaneous disappearance of the middle cerebral artery occlusion between days 5 and 8, while CBF showed reperfusion of the borderzone with flow increasing over several days after resolution of the occlusion with flows reaching levels above that of the opposite non-affected side ("Luxury Perfusion"). The delayed reflow implies, that SPECT may not constitute a reliable tool for evaluating the success or failure of thrombolytic treatment in ischemic stroke.