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

OBJECTIVE To evaluate the effects of test bolus technique with small dose of contrast agent on ankle level in lower extremity arterial CT angiography(CTA),and to study the correlation of 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%(n=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 Ⅱ clinical manifestation have multi-segmental extensive arterial occlusive characteristics.