双源CT双能量减影诊断下肢血管疾病

目的 探讨双源CT(DSCT)血管能量减影技术在下肢动脉疾病诊断中的应用价值.方法 对32例下肢动脉闭塞性病变患者行双源CT直接去骨CTA(DE-BR-CTA)检查,经工作站减影处理,获取容积再现及最大密度投影图像,其后2周内行数字减影血管造影(DSA)检查.以DSA为标准,由2名有经验的放射科医生评价DE-BR-CTA图像的动脉血管可见度及血管狭窄程度,并对其进行统计学分析.结果 两种成像方法有较好的一致性,DE-BR-CTA与DSA图像的血管可见度差异无统计学意义(P＞0.05),以 DSA 为标准评价32例被检查者328个节段中,12个偏心性狭窄节段被DE-BR-CTA 高估,6个节段狭窄程度被低估.DE-BR-CTA对下肢动脉狭窄或闭塞狭窄程度≥10%的诊断准确性为94.51%,敏感性96.15%,特异性93.02%,阳性预测值92.59%,阴性预测值96.39%.结论 DSCT能量减影血管成像技术是一种准确的、非侵袭性的检查方法,可为术前评价和筛选下肢动脉疾病提供可靠的参考依据.

Application of energy subtract angiography of dual source CT in diagnosis of arterial diseases of the lower extremities

Objective To observe the value of dual source CT (DSCT) dual energy subtract method in diagnosis of lower extremity arterial occlusion. Methods Thirty-two patients with lower extremity arterial occlusive diseases underwent DSCT direct bone removal CT angiography (DE-BR-CTA) and digital subtraction angiography (DSA) within 2 weeks. Raw data were reconstructed with techniques including MIP and VR. Arterial visibility of DE-BR-CTA was analyzed by two experienced radiologists taking DSA as the standard. Results A total of 328 arterial segments were selected in 32 patients with lower extremity arterial occlusive diseases. The correlation between DSA and DE-BR-CTA was good. There was no significant difference in arterial visibility between DE-BR-CTA and DSA (P＞0.05). Compared with DSA, 12 of the segmental stenosis were "overestimated" and 6 were underestimated with DE-BR-CTA. When stenosis was over 10%, the accuracy, sensitivity, specificity, positive predictive value and negative predictive value of DE-BR-CTA was 94.51%, 96.15%, 93.02%, 92.59% and 96.39%, respectively. Conclusion DSCT energy subtraction angiography is an accurate diagnostic method and non-invasive imaging technology in the assessment of lower extremity arterial occlusive diseases. It may provide precious information for pre-surgery evaluation and screening the arterial diseases of the lower extremities.