Figure 1.
Evaluation of computational fluid dynamics model of an atherosclerotic lesion of left middle cerebral artery.
A: Post- and pre-stenotic pressures were measured using spherical volumes-of-interest (VOI, double arrows) at the first anatomically normal diameters distal (VOI 1) and proximal (VOI 2) to the lesion, respectively. The pressure ratio was calculated by dividing the mean pressure at VOI 1 by the mean pressure at VOI 2. B: Shear strain rates (SSR) were respectively measured at the stenotic throat (cut-plane 1) and at the first anatomically normal diameter (cut-plane 2) proximal to the lesion, by using cut-planes perpendicular to the direction of blood flow (arrow). The SSR ratio was calculated by dividing the SSR averaged over cut-plane 1 by the SSR averaged over cut-plane 2. C: Velocities were similarly measured (arrow) as with the SSRs, and the velocity ratio was similarly calculated as with the SSR ratio.
Table 1.
Baseline characteristics of all patients, and patients with and without recurrent ischemic stroke in the territory of the qualifying artery.
Table 2.
Results of univariate Cox regression for predictors of recurrent ischemic stroke in the territory of the qualifying artery.
Figure 2.
Kaplan-Meier curves for the cumulative probabilities of recurrent ischemic stroke in the territory (SIT) of the stenotic artery within 1 year after ictus, according to the shear strain rate (SSR) ratio (≥ or < median) as evaluated on the computational fluid dynamics models.
Intracranial atherosclerotic lesions with a SSR ratio of ≥ median may relate to a higher risk of SIT, compared with lesions with a SSR ratio of < median (HR 5.483; 95% CI, 1.105–27.211; log-rank P = 0.079).
Figure 3.
Kaplan-Meier curves for the cumulative probabilities of recurrent ischemic stroke in the territory (SIT) of the stenotic artery within 1 year after ictus, according to the velocity ratio (≥ or < median) as evaluated on the computational fluid dynamics models.
Intracranial atherosclerotic lesions with a velocity ratio of ≥ median may relate to a higher risk of SIT, compared with lesions with a velocity ratio of < median (HR 5.483; 95% CI, 1.105–27.211; log-rank P = 0.079).
Figure 4.
Receiver operating characteristic curves for shear strain rate ratio (left) and velocity ratio (right) to predict recurrent ischemic stroke in the territory of the qualifying artery.
SIT indicates recurrent ischemic stroke in the territory of the qualifying artery; AUC, area under curve.