technetium-tc-99m-exametazime and Brain-Infarction

A simple method to predict the final infarct volume within 6 h of onset of hemispheric ischemic stroke based on the measurement of cerebral blood flow (CBF) using single photon emission computed tomography (SPECT) with techneticum-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO) was investigated in a clinical model involving patients without definite early reperfusion or clinical recovery.. A group of 16 patients (group 1) was used to establish the methodology, which was then validated in a second group of 14 patients (group 2). The final infarct volume was defined using computed tomography (CT) performed at least 7 days after stroke. The relative CBF threshold value, expressed as a percentage of the mean contralateral hemispheric value, which most closely estimated the final infarct size on coregistered CT was established for each patient.. The mean threshold CBF value for group 1 was 63.7%. When this value was used to predict infarct size in group 2, a close correlation was observed between the actual and the estimated sizes (r = 0.973, p < 0.0001). This value was not time dependent.. If no significant early reperfusion or clinical recovery occurs, a CBF threshold value of 63.7% on (99m)Tc-HMPAO SPECT performed within 6 h of stroke onset will reliably predict the final infarct size.

Topics: Aged; Aged, 80 and over; Brain Infarction; Cerebrovascular Circulation; Female; Humans; Male; Middle Aged; Radiopharmaceuticals; Reproducibility of Results; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

There have been few direct comparisons between MR perfusion-weighted imaging (PWI) and established perfusion imaging techniques, and none in chronic stroke. We therefore studied 17 chronic hemispheric infarction patients (mean, 90 days) and compared hypoperfusion volumes determined from PWI maps of relative cerebral blood flow (rCBF) and volume (rCBV), and mean transit time (rMTT) with those measured with (99)Tc-HMPAO single photon emission computed tomography (SPECT). Comparisons were also made between infarct size (T(2)-WI) and clinical scales. Correlations were found between lesion location and volume in all three PWI hemodynamic parameter maps with clinical state and lesions on SPECT and T(2)-WI. In 3 patients, rCBF and rCBV lesions extended well beyond the borders of moderate-sized infarctions. We conclude that in chronic stroke, PWI can delineate regions of abnormal perfusion that reflect the degree of functional impairment and structural damage. The finding of peri-infarct hypoperfusion suggests that PWI may have the potential to provide a rapid and non-invasive template against which interventional strategies aimed at promoting functional recovery may be investigated.

Topics: Aged; Aged, 80 and over; Brain Infarction; Cerebrovascular Circulation; Chronic Disease; Contrast Media; Female; Gadolinium DTPA; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Atlanto-Occipital Joint; Brain Infarction; Cerebellar Diseases; Humans; Joint Dislocations; Male; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime