Quantitative perfusion computed tomography measurements of cerebral hemodynamics: Correlation with digital subtraction angiography identified primary and secondary cerebral collaterals in internal carotid artery occlusive disease

Cerebral hemodynamic evaluation of parent artery occlusion for giant intracranial aneurysm in patients who tolerated balloon test occlusion: two case reports

“…PCT is now mainly used to predict the presence of an ischemic penumbra following acute cerebral infarction and to evaluate cerebrovascular reserve capacity in chronic ischemia (1,6,8). In the present cases, the two patients exhibited different patterns of hemodynamic change before and after PAO.…”

Ophthalmic Artery Flow and Cognitive Performance in Patients with Carotid Artery Stenosis

“…The above results suggest patients with reversed OA flow may be more vulnerable to subsequent cerebral ischemic events than those with forward OA flow. On the other hand, the presence of reversed OA flow can supply more blood flow to the brain in patients with unilateral carotid artery stenosis/ occlusion [14] and the intracranial arterial flow velocity and cerebral blood flow (CBF) are maintained symmetrically between the bilateral cerebral hemispheres [12,15]. After carotid revascularization, profound improvement in cerebral hemo dynamics can be reconstituted within a…”

“…Furthermore, patients with reversed OA flow are more vulnerable to impaired vasoreactivity than patients without reversed OA flow [13]. Cheng et al [12] adopted CT perfusion to investigate the influence of reversed OA flow on various perfusion profiles. They found that the relative CBF did not significantly differ between patients with and without reversed OA flow, but the relative CBV and TTP were increased in patients with reversed OA flow.…”

“…Cerebral hypo perfusion is one of main clinical manifestations in patients with severe CAS, and can be measured directly by various imaging techniques, such as CT perfusion [12,16,20], MR perfusion [14,21,22], single photon emission computed tomography [23], and positron emission tomography [24,25] imaging. In patients with mildly decreased cerebral perfusion pressure, the overall cerebral perfusion can be maintained by autoregulatory mechanisms; the cerebral blood volume (CBV), TTP and even oxygen extraction fraction (OEF) are gradually increased while the CBF remains unchanged or slightly decreased [26].…”

“…Hu et al [11] reported more subsequent cerebral ischemic stroke could be seen in patients with reversed OA flow than those with forward OA flow, especially in asymptomatic patients. Cheng et al [12] found patients with signs of recruiting secondary collaterals had worse cerebral hemodynamic profiles on computed tomography (CT) perfusion imaging compared to those patients only with signs of recruiting primary collaterals from the circle of Willis. Hofmeijer et al [13] revealed in symptomatic carotid artery occlusion, patients recruiting Willisian collaterals plus reversed OA flow or leptomeningeal collaterals may have a worse vascular reactivity than those with Willisian collaterals alone.…”