16层螺旋CT血管造影在下肢动脉成像中的初步应用

The application of CTA on lesion of artery of lower limb with 16 -slice spiral CT

目的 探讨16层螺旋CT血管造影技术(CT angiography,CTA)诊断下肢动脉病变的价值及技术特点。方法 对44例临床疑下肢动脉病变的病人行螺旋CT下肢动脉增强扫描,扫描范围1100-1200mm,层厚2.5-5mm,螺距1.375-1.75,重建层厚1.25mm,重叠50％。对比剂量120-150ml,注射速率2.5-3ml/s,Smartprep自动触发扫描,扫描时间24-35s。对全部重建图像行MIP,VR重建,并对图像进行评价。其中6例同期进行了DSA检查,8例行手术治疗。结果 44例可疑下肢动脉病变患者的下肢动脉在CTA上得以清晰显示。其中下肢动脉硬化性闭塞36例,动静脉畸形2例,髂总动脉瘤1例,腹主动脉瘤2例,3例未见异常。在下肢动脉硬化性闭塞的36例中,肾动脉以下腹主动脉狭窄7例,闭塞2例;髂总动脉狭窄5例,闭塞4例;髂内外动脉狭窄7例,闭塞7例;股动脉狭窄14例,闭塞19例;腘动脉狭窄5例,闭塞12例;小腿动脉狭窄17例,闭塞20例。29例显示管壁钙化。与DSA和手术结果比较的14例中,敏感性92.9％,特异性100％,准确性92.9％。 结论 16层螺旋CT血管造影能较好地显示下肢动脉及其病变,可以成为下肢动脉病变术前评价和筛选的主要方法。

Objective To evaluate the technical superiority of 16-slice spiral CT angiography on the lesion of artery of lower limb. Methods 44 cases with lesion in artery of lower limb diagnosed clinically were performed enhanced 16-slice spiral CT. Slice width 1100-1200mm, slice thickness 2.5-5mm, pitch 1.375-1.75,slice increment 1.25 mm,overlap 50%, the volume of contrast agent 120-150ml, flow rate 2.5-3ml/s. Scan with Smartprep auto-trigger. All scan time 24-35s. All reconstructed images were reformed by means of MIP、VR and evaluated. DSA 6 cases and surgical exposition served as control group 8 cases. Results 44 cases doubtfully with disease in artery of lower limb were demonstrated successfully with CTA. The diagnosis included stiffened occlusion 36 cases, arteriovenous malformation (AVM) 2 cases, iliac communis aneurysm 1 case, femoralis aneurysm 2 cases, normal vessel 3 cases. The stiffened occlusion group were comprised of stenosis 7 cases and occlusion 2 cases in aorta abdominalis below renalis, stenosis 5 cases and occlusion 4 cases in a.iliaca communis, stenosis 7 cases and occlusion 7 cases in a. iliaca interna, stenosis 14 cases and occlusion 19 cases in femoralis, stenosis 5 cases and occlusion 12 cases in a poplitea, stenosis 17 cases and occlusion 20 cases in artery of crus. Calcification of artery wall was found in 29 cases. Compared by DSA and surgical result, sensitivity was 92.9%, specificity 100% and accurate rate 92.9%. Conclusion The lesion in artery of lower limb could be well demonstrated by 16 -slice spiral CT angiography, and served as pre-surgery evaluation and primary method.