双源CTA对下肢动脉慢性完全闭塞的诊断能力——与DSA对照研究

Diagnostic Ability of Dual-Source CTA for Chronic Total Occlusion of Lower Extremity Arteries—A Comparative Study with DSA

摘要: 目的：以DSA为金标准，研究双源CTA常规扫描联合延迟扫描及CT值反向递减征象诊断下肢动脉慢性完全闭塞的价值。方法：选取2019年1月~2022年3月于我院行下肢动脉双源CTA检查且在近一周内行DSA检查的120位患者，120位患者均经常规CTA显示为动脉期局部管腔完全不显影或显示为完全闭塞，对上述患者进行下肢动脉延迟扫描，并测定CT值确定CT值反向递减征象是否存在。以DSA结果为诊断金标准，分别以常规CTA、常规CTA联合延迟扫描、常规CTA联合CT值反向递减征象、常规CTA联合延迟扫描及CT值反向递减征象进行诊断，使用McNemar检验比较检出率，进行Kappa一致性检验，并计算不同CTA诊断方式诊断下肢动脉完全闭塞的特异性和诊断符合率。结果：120位患者中经常规双源CTA诊断为完全闭塞的血管共236段，经DSA诊断为完全闭塞的血管为202段，重度狭窄的血管为34段；常规CTA联合延迟扫描、常规CTA联合CT值反向递减征象、常规CTA联合延迟扫描及CT值反向递减征象分别将236段血管中的223、218、207段诊断为完全闭塞血管。McNemar检验结果显示，DSA (金标准)对于动脉完全闭塞情况的检出率与常规CTA联合延迟扫描、常规CTA联合CT值反向递减征象的检出率存在差异(P < 0.001)，可认为两种方法检验结果存在差别。Kappa分别为0.514、0.658，提示两种诊断结果存在一致性，但一致性一般。DSA (金标准)对于动脉闭塞情况的检出率与常规CTA联合延迟扫描及CT值反向递减征象的检出率不存在差异(P = 0.063)，可认为两种方法检验结果不存在差别，Kappa = 0.908，一致性极高。常规CTA、常规CTA联合延迟扫描、常规CTA联合CT值反向递减征象、常规CTA联合延迟扫描及CT值反向递减征象诊断下肢动脉完全闭塞的特异性分别是0% (因本研究只纳入了被常规CTA诊断为完全闭塞的动脉节段)、38.2%、52.9%、85.3%，四种诊断方法的诊断符合率分别为85.6%、91.1%、93.2%、97.9%。特异性和诊断符合率以常规CTA联合延迟扫描和CT值反向递减征象为最高，其次为常规CTA联合反向递减征象，再其次为常规CTA联合延迟扫描，以常规CTA最低。结论：常规双源CTA联合延迟扫描和CT值反向递减征象可明显提高CTA对下肢动脉慢性完全闭塞的诊断能力。

Abstract: Objective: To investigate the value of dual-source CTA routine scan combined with delayed scan and reverse attenuation gradient sign of CT value in the diagnosis of chronic total occlusion of lower ex-tremity arteries with DSA as the gold standard. Methods: A total of 120 patients who underwent dual-source CTA examination of lower extremity arteries in our hospital from January 2019 to March 2022 and underwent DSA examination within one week later were included in the study. CTA routine scan showed that the lumen of local artery was completely unseen in all 120 patients or showed complete occlusion, delayed scan of lower extremity arteries was performed on the above-mentioned patients, and CT values were measured to determine whether there were signs of reverse attenuation gradient. Taking DSA as the gold standard, CTA routine scan, CTA routine scan combined with delayed scan, CTA routine scan combined with reverse attenuation gradient sign of CT value, CTA routine scan combined with delayed scan and reverse attenuation gradient sign of CT value were used for diagnosis. McNemar test was used to compare the detection rate, and Kappa test was used for consistency. The specificity and diagnostic coincidence rate of different CTA methods in the diagnosis of total arterial occlusion of lower extremity were calculated. Results: Among the 120 patients, there were 236 locations of blood vessels diagnosed as complete occlusion by dual-source CTA routine scan, 202 locations of blood vessels were diagnosed as total occlusion by DSA, and 34 locations of blood vessels were diagnosed as severe stenosis; CTA routine scan com-bined with delayed scan, CTA routine scan combined with reverse attenuation gradient sign of CT value, CTA routine combined with delayed scan and reverse attenuation gradient sign of CT value in the diagnosis identified 223, 218 and 207 of the 236 locations of blood vessels as completely oc-cluded blood vessels, respectively. McNemar test results showed that the detection rate of DSA for complete arterial occlusion was different from the detection rate of CTA routine scan combined with delayed scan and CTA routine scan combined with reverse attenuation gradient sign of CT value (P < 0.001); Kappa were 0.514 and 0.658, indicating that there was consistency between the two diag-nostic results, but the consistency was general. The detection rate of DSA for arterial occlusion was not different from the detection rate of CTA routine combined with delayed scan and reverse atten-uation gradient sign of CT value (P = 0.063), so there was no difference in the results of the two methods. Kappa = 0.908, indicating high consistency. The specificity of CTA routine scan, CTA rou-tine scan combined with delayed scan, CTA routine scan combined with reverse attenuation gradi-ent sign of CT value, CTA routine combined with delayed scan and reverse attenuation gradient sign of CT value in the diagnosis of complete occlusion of lower extremity arteries were 0% (Only seg-ments diagnosed as completely occluded by CTA routine scan were included in this study), 38.2%, 52.9%, and 85.3%. The diagnostic coincidence rates of the four methods were 85.6%, 91.1%, 93.2% and 97.9%, respectively. The specificity and diagnostic coincidence rate were the highest with CTA routine combined with delayed scan and reverse attenuation gradient sign of CT value, followed by CTA routine scan combined with reverse attenuation gradient sign of CT value, followed by CTA rou-tine scan combined with delayed scan; CTA routine scan was the lowest. Conclusion: Dual-source CTA routine scan combined with delayed scan and reverse attenuation gradient sign of CT value can significantly improve the diagnostic ability of CTA for chronic total occlusion of lower extremity ar-teries.