能谱CT体外鉴别渗出性与漏出性浆膜腔积液的价值

目的探讨宝石能谱CT在体外鉴别浆膜腔渗出性与漏出性积液的价值。材料与方法收集42例胸腔积液或腹腔积液体外样本,根据Light's标准将其分为渗出液组(n=32)和漏出液组(n=10)。对积液进行体外能谱CT扫描,应用宝石能谱成像软件,测量样本的有效原子序数、水(碘)浓度、碘(水)浓度、40-140KeV(间隔5KeV)单能量CT值和混合能量CT值、计算能谱曲线斜率。比较两组各指标的差别,组间计量比较采用独立样本t检验。结果渗出液组的有效原子序数、混合能量CT值及能谱曲线斜率(7.26±0.24、13.16±7.64HU和0.25±0.12)与漏出液组的(7.32±0.09、8.56±4.89HU和0.23±0.09)无差别(p0.05)。渗出液组水(碘)浓度(1024.87±5.44mg/ml)高于漏出液组(1017.60±4.45mg/ml)(p0.05);而碘(水)浓度渗出液组(-3.24±1.51mg/ml)与漏出液组(-3.04±1.10mg/ml)无差别(p0.05)。在40-50KeV单能量区间两组CT值无差别(p0.05);在55-140KeV单能量区间渗出液组CT值高于漏出液组(p0.05)。结论能谱CT体外测定浆膜腔积液的水(碘)浓度和55-140KeV单能量区间CT值可能对鉴别渗出液与漏出液有帮助,其临床应用价值需待进一步研究。

The Value of Spectral CT in Differentiating Exudative Serous Cavity Effusion from Transudates in Vitro

Objective To assess the value of spectral CT in differentiating serous cavity effusion.Materials and Methods 42 cases serous cavity effusion samples （32 exudates and 10 transudates） underwent spectral CT imaging. Using gemstone spectral imaging（GSI） viewer, the effective-Z（EFF-Z）,CT values of water-iodine concentration, iodine-water concentration, 40-140KeV monochromatic images（interval of 5KeV）, 140KVp QC and slope of spectral curve were measured. The difference of the spectral characteristic parameters was evaluated statistically by independent-samples t test.Results The EFF-Z, CT values on 140 KVp QC and slope of spectral curve don＇t show any statistically significant difference between exudates and transudates. CT values of water-iodine concentration of exudates was higher than that of transudates. But there was no difference on iodine-water concentration between the two groups. There was statistically significant difference on 55-140KeV between the two groups, however, there was no statistically significant difference on 40-50KeV.Conclusion Some spectral CT characteristic parameters especially 55-140KeV monochromatic images and water-iodine concentration maybe can differentiate exudates from transudates in vitro. There may be more search on the topic.