Objective To evaluate a noninvasive vessel encoded imaging for selective mapping of the flow territories of the left and right internal carotid arteries and vertebral-basilar arteries. Methods Seven volunteers [(33.5±4.1) years ; 3 men, 4 women] and 6 patients [(55.2 ± 3.2) years; 2 men,4women] were given written informed consent approved by the institutional review board before participating in the study. A pseudo-continuous tagging pulse train is modified to encode all vessels of interest. The selectivity of this method was demonstrated. Regional perfusion imaging was developed on the same arterial spin labeling sequence. Perfusion-weighted images of the selectively labeled cerebral arteries were obtained by subtraction of the labeled from control images. The CBF values of hemisphere, white matter, and gray matter of volunteers were calculated. The vessel territories on patients were compared with DSA. The low perfusion areas were compared with high signal areas on T2-FLAIR. Results High SNR maps of left carotid, right carotid, and basilar territories were generated in 8 minutes of scan time. Cerebral blood flow 100 g-1 were in agreement with data in the literature. Vessel encoded imaging in patients had a good agreement with DSA. The low perfusion areas were larger than high signal areas on T2-FLAIR. Conclusion We present a new method capable of evaluating both quantitatively and qualitatively the individual brain-feeding arteries in vivo.

Objective To study the correlation between carotid bifurcation geometry and atherosclerotic plaque vulnerability using high-resolution magnetic resonance vessel wall imaging(HRMR-VWI),and to seek the potential predictor for vulnerable plaque for-mation.Methods The clinical information and imaging data of 104 patients with carotid bifurcation plaque detected by HRMR-VWI were analyzed retrospectively.Carotid bifurcation geometric parameters was measured to determine whether the carotid bifurcation plaque was vulnerable plaque,and they were divided into vulnerable plaque group(69 cases)and stable plaque group(35 cases).The difference of carotid bifurcation geometry of various groups was investigated,and the influence of common traditional risk factors to obtain independent risk factors was adjusted.Receiver operating characteristic(ROC)curve was drawn.Results Among 104 carotid artery,vulnerable plaque group had larger bifurcation angle(54.00 vs 48.80,P＜0.001),less luminal expansion(1.76 vs 1.94,P=0.002)and less outflow/inflow area ratio(0.79 vs 0.88,P＜0.001)compared with stable plaque group.After adjusting,binary logistic regres-sion indicated that bifurcation angle[odds ratio(OR)1.132 per 10° increase;95％confidence interval(CI)1.044-1.225],luminal expan-sion(OR 0.084 per 1 increase;95％CI 0.014-0.492)and outflow/inflow area ratio(OR 0.357 per 0.01 increase;95％CI 0.177-0.723)were independent risk factors of vulnerable plaque formation.Bringing them into the final model,the area under the curve(AUC)was 0.878 above the basic model(AUC=0.664).Conclusion Bifur-cation angle,luminal expansion and outflow/inflow area ratio are independently associated with vulnerable plaque formation.Carotid bifurcation geometry have the certain predictive efficiency of vulnerable plaque formation and have the incremental diagnostic value to traditional risk factors,which are expected to be effective imaging makers for the formation of vulnerable plaque.