Abstract
The Tc-99m-HMPAO SPECT was corrected with an optimized filtering, and converted into regional cerebral blood flow (rCBF) after Lassen linearization correction, taking as reference a quantitative but not tomographic measurement of cerebellar rCBF by inhalation of Xe-133. The rCBF at the center of the ischaemic area and at the opposite side were measured in 38 patients (mean age: 61 years +/- 17) suffering from ischaemic cerebrovascular disorders. The mean rCBF measured at the opposite side was 37 +/- 9 mL/min/100 g. The rCBF measured al the ischaemic region corelated with the severity of the vascular event: 11 patients with transient ischaemic attack had a mean rCBF in the ischaemic areas of 22 +/- 5 mL/min/100 g (n = 11) and all measurements were greater than 16 mL/min/100 g; the 13 patients suffering from prolonged reversible ischaemic neurological deficit had a mean rCBF in the ischaemic areas of 18 +/- 5 mL/min/100 g (n = 15), five measurements were in the range of 8-16 mL/min/100 g, the others were higher than 16 mL/min/100 g; nine out of the ten patients suffering from cerebral cortical infarct had a mean rCBF in the ischaemic areas of 4.5 +/- 3.6 mL/min/100 g (n = 11), two measurements were within 8-16 mL/min/100 g, the others were less than 8 mL/min/100 g, three patients presented a luxury perfusion. The rCBF in the ischaemic areas of three patients suffering from subcortical infarct fluctuated between 10 and 42 mL/min/100 g, the mean was 23 +/- 12 mL/min/100 g (n = 4). These results are consistant with the thresholds of necrosis and oligemia wherever the size of the ischaemic area is superior to the spatial resolution of Tc-99m-HMPAO SPECT.