Correlation analysis between the degree of stenosis and hemodynamic parameters in symptomatic middle cerebral artery atherosclerotic stenosis

Functional assessment of luminal stenosis, especially hemodynamic evaluation, is now a key focus in the precision management of intracranial atherosclerotic stenosis (ICAS). Nevertheless, the lack of a straightforward yet accurate morphological metric to reflect post-stenotic hemodynamic changes poses a critical challenge, the resolution of which carries substantial clinical implications.

This study employs high-resolution vessel wall imaging (HR-VWI) to assess the degree of luminal stenosis in symptomatic middle cerebral artery (MCA) narrowing and utilizes computational fluid dynamics (CFD) to derive the translesional pressure ratio (PR). The aim is to investigate the correlation between PR and two current morphometric methods for quantifying luminal stenosis: diameter stenosis (DS) and area stenosis (AS).

Patients with unilateral atherosclerotic MCA-M1 stenosis (50–99%) were recruited. First, relevant morphological parameters were measured on HR-VWI images to obtain luminal stenosis rates (DS and AS). Then, based on three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), CFD technology was applied to derive the PR. Finally, the relationships between DS, AS, and PR were compared and analyzed.

A total of 50 patients with symptomatic MCA-M1 stenosis (50–99%) were included. The median translesional PR derived from CFD was 0.56, with a median of 0.71 for DS and 0.74 for AS. However, the difference between the two correlation coefficients was not statistically significant. Exploratory receiver operating characteristic (ROC) curve analysis using PR ≤ 0.8, ≤ 0.75, and ≤ 0.7 demonstrated that AS consistently outperformed DS, with significantly higher AUCs at all thresholds (all P < 0.05): at ≤ 0.8, AS AUC = 0.905 (95% CI 0.788–0.970) vs. DS 0.805 (0.668–0.903); at ≤ 0.75, AS AUC = 0.923 (0.812–0.979) vs. DS 0.882 (0.760–0.956); and at ≤ 0.7, AS AUC = 0.836 (0.704–0.925) vs. DS 0.810 (0.675–0.907).

In this exploratory study, regarding the measurement methods for the degree of luminal stenosis, DS and AS, AS shows a stronger correlation with PR. However, the difference in correlation coefficients was not statistically significant, and the findings require validation in larger cohorts with established intracranial thresholds.