超声造影对动脉狭窄检测的实验研究

The experimental study of the contrast-enhanced sonography in the assessment of artery stenosis

目的 比较彩色多普勒超声造影（彩超造影）与实时灰阶谐波超声造影（谐波造影）两种方法 对动脉狭窄性疾病的诊断及对狭窄程度的评价.方法普通家犬5只,超声造影剂为SonoVue.选择犬的双侧髂总动脉制作狭窄程度分别为50%～60%、60%～70%、70%～80%、80%～90%及＞90%的狭窄共8段.狭窄段长度约10～15 mm.人为增加血管深度至彩色多普勒血流显像不能清晰显示彩色血流,采用彩超造影与谐波造影两种方法进行检查,分别对狭窄程度作出评价并与数字减影血管造影（DSA）的检查结果相对照.结果 所有狭窄节段中除1例因声束-血流夹角（θ）超过60°未能测及有效流速外,以狭窄段收缩期峰值流速（PSV）/狭窄前PSV＞2为诊断50%以上狭窄的标准,彩超造影对其他狭窄均能诊断,但是不能准确判断狭窄程度;谐波造影检测到的狭窄率及狭窄段的长度与DSA结果对照具有良好的相关性（r=0.94 及 0.63）.结论 谐波造影能更直接地显示流道与管壁的异常,因而对狭窄程度的判断也更加准确.

Objective To evaluate the ability of contrast-enhanced color Doppler ultrasonography （CDUS） and real-time harmonic gray scale imaging in the diagnosis of arterial stenosis and the assessment of the stenosis degree. Methods Five dogs were operated to create arterial stenosis at the common lilac arteries. Eight models were made including different stenoses grade of 50% ～60% ,60%～71%, 70%～ 80%,80%～90% and 〉90%. The length of stenosis area was 10～15 mm. The depth of the vessels was increased with fresh pork until the blood flow could not be displayed clearly on color Doppler flow imaging （CDFI）. The degree of stenosis was evaluated by contrast-enhanced color Doppler and harmonic imaging respectively. The results of ultrasonography were compared with those of digital subtraction angiography （DSA）. Results The systolic peak velocity（PSV） could not be measured in one model duo to the large angle between incidence and the flow direction in this study. All remained stenostic areas were diagnosed by CDUS with a cut-off point to be Vratio （PSV stenosis/ PSVpre-stenosis）〉 2, but precise estimation of stenoses was impossible on CDUS. The stenosis degree and the length of stenosis measured by contrastenhanced harmonic gray scale imaging were correlated well with those of DSA （ r = 0.94 and 0.63, respectively）. Conclusions Microbubbles fill the arterial lumen with echoes at contrast-enhanced harmonic gray scale imaging. The ability to visualize the inner and outer surfaces of the vascular wall improved the evaluation of luminal abnormalities.