光谱CT单期增强扫描鉴别左心耳血栓与血流淤滞的临床初探

Clinical Study on Differential Diagnosis of Left Atrial Appendage Thrombus and Blood Flow Stasis by Spectral CT Single-Phase Scanning

目的:评估光谱CT单期增强检查对于鉴别左心耳血栓和血流淤滞的应用价值。方法:回顾性收集2021年9月至2023年3月因房颤在我院行左心房CT血管成像检查的患者共86例。每例患者均在Philips IQON Spectral CT接受双期增强扫描;以双期增强扫描诊断结果为参考标准,定量测量单期左心耳充盈缺损区碘浓度。采用独立样本t检验比较血栓及血流淤滞处碘浓度的差异。结果:入组患者22例,其中诊断为左心耳血栓2例,诊断为血流淤滞16例,诊断为血栓合并血流淤滞4例。增强第一期图像生成的碘浓度图中,血栓处碘浓度[(0.68±0.47)mg/mL]明显低于血流淤滞处[(3.51±1.25)mg/mL,P<0.001],经过受试者工作特征曲线分析得到截断值1.80 mg/mL时有较高鉴别诊断效能。结论:光谱CT单期增强扫描碘浓度测定可帮助鉴别左心耳血栓和血流淤滞。

Purpose:To evaluate the value of single-phase spectral CT in differentiating left atrial appendage thrombosis and blood flow stasis.Methods:A total of 86 patients with atrial fibrillation who underwent left atrial CT angiography in our hospital from September 2021 to March 2023 were collected retrospectively.Each patient underwent biphasic enhanced scan at Philips IQON Spectral CT.The iodine concentration in single-phase left atrial appendage filling defect area was measured with reference to the diagnostic results of biphasic contrast-enhanced scanning.Independent sample t test was used to compare the difference of iodine concentration between thrombus and blood flow stasis.Results:Twenty-two patients were enrolled,including 2 patients diagnosed with left atrial appendage thrombus,16 patients diagnosed with blood flow stasis,and 4 patients diagnosed with thrombus combined with blood flow stasis.In the iodine concentration(IC)map generated by enhanced first-stage images,the IC at the thrombus[(0.68±0.47)mg/mL]was significantly lower than that at the blood flow stasis point[(3.51±1.25)mg/mL,P<0.001].Through receiver operating characteristic curve analysis,it was found that the IC cutoff of 1.80 mg/mL had higher differential diagnosis efficiency.Conclusion:The iodine concentration measurement by single-phase enhanced spectral CT may help identify left atrial appendage thrombus and blood flow stasis.