下肢动脉闭塞性疾病的64层螺旋CT血管造影表现与临床特征的相关性分析

Correlation analysis of 64-slice spiral CT angiography and clinical characteristics for lower extremity arterial occlusive diseases

[目的]评价踝部小剂量对比剂预试验技术在下肢动脉CT血管造影(CTA)检查中的作用,探讨下肢动脉闭塞性疾病的CTA表现特征的相关性.[方法]使用64层螺旋CT进行下肢动脉CTA扫描,其中25例采用踝部小剂量对比剂预试验注射技术,38例采用示踪法技术;分析腹主动脉、踝部动脉峰值变化及下肢动脉CTA表现特征.[结果]63例个体间胫前动脉达峰时间(TTI)差异较大(35.0～75.0s),平均时间为48.6s±9.7s;示踪法技术组34.2%(13/38)的病例小腿段以下动脉显示不良.下肢皮肤坏疽13例中动脉闭塞为12例(92.3%),28例静息痛患者中为27例(96.4%),11例间歇性跛行或活动后疼痛患者中为10例(90.9),且多为2段以上动脉闭塞(67.8%～81.8%).无疼痛的11例下肢动脉的狭窄程度均在中度以下;82.5%(52例/63例)的病例发现动脉粥样硬化斑块,多节段弥漫性分布为主.[结论]踝部小剂量对比剂预试验技术可以提高下肢动脉CTA图像质量,有助于准确判断动脉狭窄程度.具有Ⅱ级以上临床表现的下肢动脉硬化性闭塞症患者以多节段动脉广泛性闭塞为特点.

OBJECTIVE To evaluate the effects of test bolus technique with small dose of contrastagent on ankle level in lower extremity arterial CT angiography（CTA）, and to study the correlation ot performance characteristics of 64-slice spiral CTA for lower extremity arterial occlusive diseases. METHODS CTA scanning for lower extremity arteries were performed by 64-slice spiral CT, and 25 cases of subjects underwent CTA by test bolus technique with small dose of contrast agent on ankle level and 38 cases of subjects underwent CTA by bolus tracking to analysis the peak changes of abdominal aorta and ankle artery level and the performance characteristics of lower extremity arterial CTA. RESULTS Time to peak of bilateral anterior tibial artery was quite different in 63 cases of subjects, and the time range was 35.0±75.0 s and the average time was 48.6 s± 9. 7 s. The 34.2% （13/38 cases） of artery under the lower limb segments showed poor in bolus tracking group. There were 92.3 % （ n - 12） of arterial occlusion in 13 cases of lower limb gangrene of skin, 96.4% （n = 27） in 28 cases of rest pain, 90.9% （ = 10） in 11 cases of intermittent claudication or pain after movement, and many of them were the more than 2 arterial occlusion （67.8% ±81.8%）. The degree of stenosis of lower extremity arteries in 11 cases without pain was in moderate. The 82.5% （52 /63 cases） were found in atherosclerotic plaques, multiple segmental diffuse distribution. CONCLUSION Test bolus technique at ankle level could improve lower extremity arterial CTA image quality, help to accurately judge the degree of arterial stenosis. Lower extremity arteriosclerosis obliterans patients with more than grade Ⅱclinical manifestation have multi-segmental extensive arterial occlusive characteristics.