Can the detection of misery perfusion in chronic cerebrovascular disease be based on reductions in baseline CBF and vasoreactivity?

Purpose: To investigate diagnostic accuracy for misery perfusion using criteria defined by baseline cerebral blood flow (CBF) and cerebral vasoreactivity (CVR) in the acetazolamide (ACZ) challenge, patients with chronic cerebrovascular disease (CVD) were studied. Methods: Oxygen extraction fraction (OEF) and other hemodynamic parameters were measured in 115 patients (64±9y) with unilateral cerebrovascular stenoocclusive disease (>70% stenosis) using 15O-gas and water PET. A significant elevation of OEF greater than mean+2SD of healthy controls was defined as misery perfusion. CBF, CVR determined by %change in CBF after ACZ administration, OEF, and other hemodynamic parameters in territories of bilateral middle cerebral arteries were analyzed. Diagnostic accuracy in detection of misery perfusion using the criteria determined by baseline CBF and CVR was evaluated in all patients and only in patients with occlusive lesions. Results: Ten of 24 patients with misery perfusion showed a significant CVR decrease. Using criteria determined by significant decreases in CVR and baseline CBF, misery perfusion was detected with sensitivity of 42% and specificity of 95% in all patients. Patients with occlusive lesions (n=50) showed higher sensitivity with slightly lower specificity. Threshold determined by baseline CBF alone provided similar diagnostic accuracy in all patients as well as patients with occlusive lesions, which was more accurate than the detection by asymmetry index of OEF (OEF-AI). Conclusion: Reductions of CVR and baseline CBF in the ACZ challenge for CVD would detect misery perfusion with high specificity. Decrease in baseline rCBF is more accurately detect misery perfusion than reduced CVR alone.