多层螺旋CT图像后处理技术对肺弥漫性粟粒样病变的诊断价值

Diagnostic Value of MSCT Image Post-Processing for Diffuse Miliary Lesions of the Lung

目的研究多层螺旋CT（MSCT）图像后处理对肺弥漫性粟粒样病变的诊断价值。方法回顾性分析2015年11月至2017年1月首都医科大学附属北京胸科医院收治的以肺部弥漫性粟粒样病变为主要征象的112例患者的MSCT资料。以5mm层厚的常规CT扫描重建为1．25mm的薄层图像，以1．25mm层厚的薄层CT行冠状面多平面重建（MPR）和最大密度投影（MIP），比较4种图像对肺弥漫性粟粒样病变和胸膜下透亮带的显示率。结果112例患者的4组CT图像中，常规CT、薄层CT、MPR和MP判定为肺弥漫性粟粒样病变分别为101例（90．2％）、105例（93．8％）、105例（93．8％）和111例（99．1％），MIP对肺弥漫性粟粒样病变的显示率高于常规（x2=10．00，P=-0．002）、薄层CT（x2=6．00，P=O．031）和MPR（x2=6．00，P=0．031）。常规CT、薄层CT、MPR和MIP发现胸膜下透亮带分别为65例（58．0％）、62例（55．4％）、81例（72．3％）和84例（75．O％），MIP对胸膜下透亮带的显示率高于常规CT（x2=19．00，P〈0．01）和薄层CT（x2=22．00，P〈0．01），MPR对胸膜下透亮带的显示率也高于常规CT（x2=16．00，P〈0．01）和薄层CT（x2=19．00，P〈0．01）。结论在肺弥漫性粟粒样病变的MSCT诊断中，MIP图像有助于明确判定病变是否存在，MIP和MPR重建图像有助于显示胸膜下透亮带，对肺弥漫性粟粒样病变的鉴别诊断有重要的指导意义。

Objective To study the diagnostic value of image post-processing of MSCT for diffuse miliary lesions of the lung. Methods Retrospective analysis of 112 cases of MSCT admitted in Beijing Chest Hospital showed diffuse pulmonary miliary lesions, during November 2015 to January 2017. The thick thin layer image of 1.25 mm was reconstructed based on the conventional layer image of 5 mm and multi-planar reconstruction （MPR） and maximum intensity projection （MIP） were reconstructed in coronal plane based on the thick thin slice image of 1.25 mm. The display rates of diffuse miliary lesions in lungs and subpleural hyperlucent zone were compared with four kinds of CT imaging. Results One hundred and twelve cases of images with or suspected diffuse miliary lesions of the lung were showed in the 4 groups CT images. Conventional CT, thin slice CT, MPR reconstructed images, MIP reconstruction images showed 101 cases （90.2%）, 105 cases （93.8%）, 105 cases （93.8%）, 111 cases （99.1%） with diffuse miliary lesions of the lung. There was significant difference between the MIP reconstruction images and the conventional CT for showing diffuse miliary lesions （ x 2=10.00, P = 0.002）. There was significant difference between the MIP reconstructed images and the reconstructed images of thin slice CT （ x 2 = 6.00, P=0.031）. There was significant difference between the MIP reconstructed images and MPR reconstructed images （ x 2=6. 00, P=0.031）. 4 groups of images showed the subpleural translucent area. MPR and MIP images showed 81 cases （72.3%） and 84 cases （75.0%） with the subpleural translucent area respectively. The conventional CT and thin slice CT showed 65 cases （58. 0%） and 62 cases （55.4%） respectively. There was significant difference between MPR or MIP reconstruction images and the conventional CT or thin slice CT （ x 2 =19.00, 22.00, 16.00, 19.00, P〈0.01 for each）. Conclusion For the diagnosis of diffuse pulmonary miliary lesions, MIP images is helpful to determine whether lesions exist. MIP and MPR reconstruction images can help to show the subpleural translucent area and have important value in the differential diagnosis of diffuse pulmonary miliary lesions.