Chronic intracranial artery stenosis: Comparison of whole-brain arterial spin labeling with CT perfusion

Purpose: To evaluate the potential clinical value of Arterial spin-labeled (ASL) through comparison with computed tomography perfusion (CTP) in patients with chronic intracranial artery (middle cerebral artery, MCA) stenosis.

Methods: Twenty-nine patients (14 female, average ages 62) were included in our study from October 2013 to August 2016. Relative cerebral blood flow (rCBF) in the MCA territory was calculated on both ASL and CTP. Patients were divided into three groups (mild, moderate and severe) based on their degree of MCA stenosis on DSA. The paired t-tests and Bland-Altman plots were used to evaluate the differences of rCBF between ASL and CTP.

Results: There was a significant difference in rCBF between ASL and CTP for all patients (P < 0.001) and for those with severe MCA stenosis (P < 0.001). For patients with mild or moderate stenosis, there were no significant differences (P = 0.496 and 0.645, respectively). The 95% limits of agreement for all patients and those with severe stenosis were (-0.25, 0.41) and (-0.13, 0.56), respectively. For patients with mild or moderate stenosis, the values were (-0.21, 0.22) and (-0.20, 0.19).

Conclusion: Compared with CTP, ASL tended to overestimate the perfusion deficit in patients with severe chronic MCA stenosis. However, ASL is noninvasive, repeatable method and can be a promising clinical diagnostic tool to evaluate patients with intracranial stenosis.