能谱CT检测中央型肺癌周围肺组织灌注缺损

目的 探讨能谱CT检测中央型肺癌周围肺组织灌注缺损的能力,并分析灌注缺损与中央肺动脉受侵的关系。方法 对30例中央型肺癌患者行宝石能谱成像(GSI)模式增强扫描,经图像后处理获得70 keV的单能CTA图像及碘基物质图像。于单能CTA图像上分析中央肺动脉受侵情况、以5分法进行评分;于碘基物质图像上测量并比较癌周肺组织与对侧相应区域正常肺组织的碘含量,计算癌周肺组织碘含量下降率并分析其与中央肺动脉受侵评分的相关性。结果 30例中央型肺癌患者中,共检出受侵中央肺动脉66支,受侵评分为(2.21±0.58)分。癌周肺组织碘含量 明显低于对侧相应区域正常肺组织碘含量,两者差异有统计学意义(t=-9.23,P<0.001);癌周肺组织碘含量下降率范围为14.5%~87.2%,中位数为52.9%,与中央肺动脉受侵评分呈明显正相关(r=0.94,P<0.001)。结论 能谱CT不仅能够检测出中央型肺癌周围肺组织灌注缺损,还能量化评价中央型肺癌中央肺动脉不同程度受侵所致癌周肺组织灌注缺损情况。

Spectral CT imaging in detecting perfusion defects of pulmonary parenchyma in patients with central lung cancer

Objective To evaluate the capability of spectral CT imaging in detecting the lung perfusion defects induced by central lung cancer, and to compare the correlation between the lung perfusion defects and the involvement of central pulmonary artery from central lung cancer. Methods Thirty patients with central lung cancer underwent enhanced CT with gemstone spectral imaging (GSI) mode. Then the monochromatic CTA imaging and iodine-based material decomposition imaging were obtained. On the monochromatic CTA images, scoring of five grades was applied to evaluate the central pulmonary artery involvement. On the iodine-based material decomposition images, iodine concentration were measured and compared between periphery of the central lung cancer and corresponding area of the contralateral normal lung, then the descent rate of iodine concentration in periphery of the central lung cancer was calculated. The correlation between the score of central pulmonary artery involvement and the descent rate of iodine concentration was analyzed. Results In thirty patients with central lung cancer, there were 66 central arteries involvement, the score was 2.21±0.58. The iodine concentration in periphery of the central lung cancer was significantly lower than that in corresponding area of the contralateral normal lung ( mg/ml vs mg/ml, t=-9.23, P<0.001). The range of the descent rate of iodine concentration in periphery of the central lung cancer was from 14.5% to 87.2% (median 52.9%). There was a significantly positive correlation between the score of central artery involvement and the descent rate of iodine concentration (r=0.94, P<0.001). Conclusion Spectral CT imaging not only can be used to detect, but also to evaluate quantitatively the lung perfusion defects induced by the different degree of central pulmonary artery involvement from central lung cancer.