Table 5.
Suggested interpretations for the Patient Type maps shown in Figure 7
| Patient | CVR | Types map |
|---|---|---|
| p3 | RH positive CVR (normal appearing). LH mostly negative (steal). | RH much of the positive CVR is type B +/−. An example of positive CVR but biphasic pattern which is not seen in normal cohort. LH steal types B +/− and D −/+. Most severe steal on CVR confirmed as type D −/+. |
| p4 | RH has reduced CVR particularly in right occipital lobe; LH appears normal. | RH negative areas of CVR are indeed biphasic type D −/+. One area in occipital lobe is complete steal (type C −/−). LH predominantly type A +/+, consistent with the normal type and extent of the CVR response |
| p5 | Extensive bilateral steal | Negative CVR is types B +/− and C −/−. Vessels in type B +/− have been shown to have increased flow for small increases in PCO2 and may be stealing from the type C −/− which reduce their flow from initial increases in PCO2. |
| p6 | Normal appearing CVR other than over the ventricles. | Extensive type A +/+ with types B +/− and C −/− over the ventricles. CVR is normal in degree and type. Presumably this patient has a well developed collateral circulation. |
| p7 | Areas of negative CVR (steal) in occipital lobe WM bilaterally. (Frontal lobes often contain susceptibility artefacts and are not usually diagnostic). | Confirmation of negative CVR as type B +/−. Type C −/− identifies the complete steal. |
| p8 | RH good CVR in cortical areas, negative CVR (steal) in WM. Extensive negative CVR (steal) in LH WM and a small region of left parietal GM. | RH cortical areas type A +/+ consistent with CVR. WM type D −/+ bilaterally. LH positive cortical CVR is type B +/− showing low CVR in areas of positive CVR. |
| p9 | Normal CVR right hemisphere. Negative CVR (steal) in LH WM. | RH: Type A +/+ confirms normal CVR. LH cortex is type B +/− indicating abnormal positive CVR. Type C −/− also identifies area of complete steal. There are type C −/− and D −/+ responses in LH WM. |
| p10 | Negative CVR (steal) in WM bilaterally, and in the inferior division right MCA (posterior temporal) and left PCA. (occipital) GM. | Much of the positive CVR is actually type B +/−. Areas of complete steal (type C −/−) nicely demonstrated in right MCA left PCA GM and WM. |
Abbreviations: RH, right hemisphere; LH, left hemisphere; CVR, cerebrovascular reactivity; WM, white matter; GM, grey matter. MCA, middle cerebral artery.