目的探讨16层螺旋CT数字减影术在颈部动脉血管成像的应用价值。资料与方法52例拟诊颈部动脉病变患者,分别采用减影术(computed tomography digital subtraction angiographyDS-CTA)及非减影术(computed tomography digital not-subtraction angiography NS-CTA)行三维血管成像,比较两种成像方法的成像时间及图像质量。10例同时接受DSA检查,其中3例为支架置入术后随访,比较DS-CTA与DSA血管成像的一致性。结果DS-CTA与NS-CTA比较,前者成像时间明显缩短,但两者图像质量差异无统计学意义,DS-CTA能较完整、清晰地显示血管。10例同时接受DSA,结果与DS-CTA一致,3例支架置入术后随访病例均显示管腔通畅,无明显狭窄。结论16层螺旋CTDS-CTA是一种快速、直观的血管成像技术,可以提供高质量的血管三维重组图像,具有较高的应用价值,可作为临床制定治疗方案的补充手段。
Background and Purpose - Clinical trials have shown that carotid endarterectomy reduces stroke risk in symptomatic individuals with severe internal carotid artery (ICA) stenosis. As a result of these trials, digital subtraction angiography (DSA)- became a standard of reference for ICA stenosis diagnosis. Newer 3D techniques provide a larger number of views than DSA, which may influence the estimated degree of stenosis. We evaluate this possibility by directly comparing stenosis grades from 3D computed rotational angiography (CRA) and DSA. Methods - As a prospective diagnostic study, we performed CRA and DSA on 26 consecutive symptomatic patients. Only 1 angiographic procedure was performed on normal asymptomatic arteries, yielding 42 arteries for comparison. Four neuroradiologists graded the CRA maximum intensity projections (MIPs) and DSA images, according to the North American Symptomatic Carotid Endarterectomy Trial guidelines. CRA studies included a search for the narrowest view by evaluating 60 MIPs generated at 3° intervals and measurement of actual artery diameters. Artery diameters and stenosis grades were analyzed graphically; statistical significance was determined using a paired t test. Results - The mean difference of 1.2% (CI, - 18% , 21% ) between CRA and DSA stenosis grades was not statistically significant (P=0.55). Agreement of the optimal CRA viewing angle was limited, with an interobserver variability of 24± 13° . The interobserver variability of DSA and CRA stenosis grades, 9.1% (CI, 0% , 21% ) and 9.4% (CI, 0% ,22% ), respectively, was not significantly different (P=0.79). Conclusion - CRA provides stenosis grades equivalent to DSA, as well as absolute measurements, providing a comparison for newer 3D techniques.
