In order to make sure the stratification of cerebral hemodynamics of child moyamoya disease, we evaluated 123I-IMP SPECT before and after surgical revascularization. The aim of this paper is toestablish the semiquantitative parameters that can be applied to estimate severity of hemodynamic cerebral ischemia instead of quantitative parameters. Quantitative studies using IMP-ARG method were performed on thirteen patients to measure resting regional rCBF, and vascular reserve (rVR): (Diamox-activated rCBF/resting rCBF-1) × 100%. Semiquantitative parameters were calculated from the ratio of ROI counts in the ACA and MCA territory to the dominant cerebellum counts (ROI/Ce ratio) at resting and Diamox-activated conditions. From the quantitative study, both mean resting rCBF less than 40m1 /100g/min and rVR less than 10% could indicate stage 2 hemodynamic cerebral ischemia. The prediction of stage 2 ischemia using semiquantitative parameters (resting ROI/Ce ratio less than 0.9 and Diamox-activated ROI/Ce ratio less than 0.85 inthe MCA territory) was not statistically different comparison to the diagnosis using quantitativeparameters (using Fisher exact test<0.0001, Sensitivity and specificity were 87.5% and90.9%, respectively). The ROI/Ce ratio can be utilized as simple parameters instead of quantitative parameters.
