宝石CT能谱成像诊断肺栓塞和肺灌注缺损的临床价值

Clinical value of dual energy spectral CT imaging in diagnosing pulmonary embolism and perfusion defect

目的评价宝石CT能谱成像的单能量图像与碘基肺灌注图诊断肺栓塞和肺灌注缺损的临床价值。方法选择56例临床怀疑肺栓塞且CT肺血管成像(CTPA)显示肺叶和肺段动脉腔内有明确充盈缺损患者,对以上病例行宝石能谱CT扫描,获得单能量CTPA图像及碘基肺灌注图。结果 56例CTPA阳性患者共显示302处血管内充盈缺损,其中叶级肺动脉65处,段级237处。56例CTPA阳性患者在碘基肺灌注图共显示203处灌注缺损区,CTPA各肺段动脉栓子显示率与碘基肺灌注图相应肺段灌注缺损区显示率间比较差异无统计学意义。碘基肺灌注图所示正常肺实质的碘基物质含量与灌注缺损肺段碘基物质含量差异有统计学意义。结论宝石CT能谱成像的CTPA单能量图像显示肺栓塞与碘基肺灌注图显示肺灌注缺损之间具有良好的相关性,可为PE和由此引起的肺实质功能变化提供可靠的诊断依据。

Objective To assess the clinical value of monochromatic and iodine - based material decomposition images by spectral CT imaging for diagnosing pulmonary embolism and perfusion defect. Methods Fifty - six patients with clinically suspected pulmonary embolism and with filling defects in the lobar pulmonary and segmental pulmonary arteries underwent CT angiography with spectral CT imaging mode by GE Discovery CT750HD scanner. Results In 56 patients, a total of 302 filling defects in the pulmonary arteries were detected, 65 in the lobar pulmonary ＇arteries and 237 in the segmental pulmonary arteries. 203 perfusion defects were detected based on the iodine images. There was no significant difference in the display rate between filling defects in the segmental pulmonary arteries and perfusion defects on the iodinebased lung perfusion images. The average iodine concentrations were 2.21 ±0. 50 mg . mL^-1 in the normal lung parenchyma and 0.74 ± 0.44 mg . mL^-1 in perfusion defects and there was significant difference （P 〈 0.05 ）. Conclusion There is good correlation between pulmonary embolism detected with the monochromatic CTA images and perfusion defect assessed with the iodine - base material decomposition images. Spectral CT may provide a reliable diagnose evidence in the evaluation of pulmonary embolism and associated functional changes in lung parenchyma.