MSCTA、2DDSA和3DDSA对颈动脉狭窄测量差异比较的实验研究

目的：比较多层螺旋CT血管造影（MSCTA）与2D数字减影血管造影（DSA）、3DDSA对颈动脉狭窄模型的测量差异。方法根据北美症状性颈动脉内膜切除术试验组（NASCET）标准，利用重力输液管制备30支血管模型，其中0级2支，1级（1％～＜30％）6支，2级（30％～＜70％）和3级（70％～＜100％）各10支，血管闭塞（4级，100％）2支，分别进行MSCTA、直径10mm钢球校准后2DDSA和3DDSA成像分析（AVA），分别测量模型血管内径、狭窄段的直径狭窄率（DSR）和面积狭窄率（ASR），并评估其狭窄程度。结果与MSCTA和2DDSA比较，3DDSA对模型内径的测量误差最大（3．08±0．09）mm]，差异具有统计学意义（t＝14．95、11．89，P＜0．01）。3种方法对同一血管狭窄模型所测出的ASR均大于DSR，3DDSA的ASR和DSR均较MSCTA和2DDSA有减低。以ASR和DSR为血管狭窄的评估参考指标，2DDSA为诊断“金标准”，MSCTA与钢球校准后2DDSA对血管狭窄程度分级的诊断一致性最佳（Kappa值分别为0．86和0．91），3DDSA对血管狭窄程度评估的可靠性较低，Kappa值为0．35和0．42。结论MSCTA能够提供全面、准确的诊断信息，可替代常规DSA用于颈动脉狭窄的诊断性评价，相对于2DDSA和MSCTA，3DDSA对颈动脉的狭窄可能具有一定程度的低估。

Comparison of MSCTA,2D DSA,and 3D DSA grading measurement accuracy in a vitro model of carotid artery stenosis

Objective To investigate the accuracy of multi‐slice spiral CT angiography (MSCTA) ,2D DSA ,and 3D DSA in grading carotid stenosis compared with actual measurement in vitro carotid model .Methods Thirty carotid stenosis models were created by infusion tubes according to the North American symptomatic carotid endarterectomy trial group (NASCET ) Standard (0 to 4 grades respectively was 2 ,6 ,10 ,10 and 2) .After MSCTA ,2D DSA(calibration with 10 mm diameter steel ball) and 3D DSA , we analysed the lumen ,diameter stenosis rate (DSR) and area stenosis rate (ASR) of vitro carotid models with the aid of advanced vessels analysis (AVA) .Results Compared with MSCTA and 2D DSA ,3D DSA had the maximum measurement error (3 .08 ± 0 .09)mm] of vitro carotid model ,and a dramatically statistic difference (t=14 .95 and 11 .89 ,P<0 .01) .In these measure methods (MSCTA ,2D and 3D DSA) ,ASR was always greater than DSR in a same stenosis model ,and 3D DSA had a tendency of underesti‐mated in calculating ASR and DSR compared to MSCTA and 2D DSA .In evaluation of diagnostic efficacy ,selected ASR and DSR as assess parameters ,2D DSA was the diagnosis gold standard of carotid stenosis ,MSCTA and 2D DSA (calibrated by steel ball) had the optimal consistency (Kappa value respectively was 0 .86 and 0 .91) ,and 3D DSA had lower reliability of diagnosis carotid artery stenosis (Kappa value=0 .35 and 0 .42) .Conclusion MSCTA provides an adequate ,preciseness ,and non‐invasive alternative with a high correlation to conventional DSA .Compare to MSCTA and 2D DSA ,3D DSA would have a tendency of underestimate the grad‐ing of carotid stenosis .