Purpose: The aim of this study was to clarify
whether decreases in baseline regional cerebral blood flow
(rCBF) and in residual cerebral vasoreactivity (CVR),
assessed by the acetazolamide (ACZ) challenge, can detect
misery perfusion in patients with chronic cerebrovascular
disease (CVD).
Methods: Oxygen extraction fraction (OEF) and other
haemodynamic parameters were measured in 115 patients
(64±9 years old) with unilateral cerebrovascular steno-
occlusive disease (>70% stenosis) using
15
O-gas and water
PET. A significant elevation of OEF, by greater than the
mean+2SD compared with healthy controls, was defined
as misery perfusion. CBF, CVR determined by percent
change in CBF after ACZ administration, OEF and other
haemodynamic parameters in the territories of the bilateral
middle cerebral arteries were analysed. Diagnostic accu-
racy for the detection of misery perfusion using the criteria
determined by baseline CBF and CVR was evaluated in all
patients and in only those patients with occlusive lesions.
Results: Ten of 24 patients with misery perfusion showed a
significant reduction in CVR. Using criteria determined by
significant decreases in CVR and baseline CBF, misery
perfusion was detected with a sensitivity of 42% and a
specificity of 95% in all patients. In patients with occlusive
lesions (n=50), sensitivity was higher but specificity was
slightly lower. The diagnostic accuracy of the threshold
determined by baseline CBF alone was similar in all
patients and in only those patients with occlusive lesions,
and was higher than that achieved using the asymmetry
index of OEF.
Conclusion: Reductions in CVR and baseline CBF in the
ACZ challenge for CVD would detect misery perfusion
with high specificity. Reduction in baseline rCBF is more
accurate than reduction in CVR alone for the detection of
misery perfusion.
