Abstract:

Objective  To evaluate the correlation between late-arriving retrograde flow downstream of M1 segmentof unilateral middle cerebral artery(MCA) and neurological function score in patients with arteriosclerotic stenosis.

Methods  The MRI data of 39 patients with symptomatic M1 stenosis(vascular stenosis rate of 50%-99%) of unilateral MCA were analyzed retrospectively. All patients underwent three-dimensional pseudocontinuous arterial spin labeling(3D pCASL) imaging with dual post-label delay(PLD) (1.5s and 2.5s), the mean cerebral blood flow(CBF) of two PLD downstream of the MCA on the lesion-side and normal-side was measured. The late-arriving retrograde flow proportion(LARFP) downstream of M1 segment of MCA on the lesion-side was calculated. The National Institutes of Health Stroke Scale(NIHSS) scores of patients on the day of the MRI scanning were recorded, and the stenosis ratio of lesioned local vascular lumen was measured.Pearson correlation analysis was used to evaluate the correlation between LARFP, NIHSS score and vascular stenosis ratio.

Results  There was a correlation between LARFP and NIHSS(r=-0.698; P＜0.001), but no correlation between vascular stenosis rate and LARFP(r=-0.001; P=0.997) or NHISS score(r=-0.127; P=0.440).

Conclusion  LARFP was significantly correlated with neurological deficit, but there was no significant correlation between vascular stenosis ratio and NIHSS score. The LARFP calculated from 3DpCASL imaging using two PLDs may become a new indicator for evaluating cerebral collateral circulation in patients in the future.

Key words: collateral circulation, magnetic resonance imaging, cerebral perfusion