弥漫性肺疾病的VHRCT、MIP、MinIP诊断价值

The Diagnostic Value of Volumetric HRCT, MIP and MinIP in Diffuse Lung Diseases

目的 探讨容积高分辨率CT(VHRCT)、最大强度投影 (MIP)及最小强度投影 (MinIP)对弥漫性肺疾病 (DLD)的诊断价值。材料与方法 对 112例DLD患者行肺部感兴趣区VHRCT扫描及MIP、MinIP重建 ,其中 46例同期进行肺功能检查。全部病例均经病理或临床综合诊断证实。结果 ( 1)MIP图像显示肺结节、磨玻璃影、血管束异常和MinIP图像显示肺低衰减敏感性均为 10 0 %。分别根据常规螺旋CT(SCT)、SCT结合VHRCT ,以及SCT、VHRCT、MIP和MinIP 4种技术图像所见进行诊断 ,DLD诊断可信度水平逐步提高 (P <0 .0 0 1) ;可信度为 3的正确诊断率显著提高 [3 1.2 5 % ( 3 5 / 112 )、5 8.93 % ( 66/ 112 )、79.46% ( 89/ 112 ) ,P1、P2均 <0 .0 0 1] ;观察者之间的意见一致性逐步提高 (Kappa值分别为 0 .62 1、0 .73 9、0 .80 9)。( 2 )MinIP图像上肺低衰减评分与结合SCT图像的综合评分呈显著正相关 ( (r =0 .867,P <0 .0 0 1) ,均与大多数肺功能指标显著相关 (P <0 .0 5 )。结论 VHRCT扫描结合MIP、MinIP重建明显增加了诊断DLD的有用信息 ,可作为诊断DLD的一种很好的补充手段。MinIP图像检出肺低衰减比较敏感 ,其评分与肺功能指标明显相关 ,可作为预测肺疾病患者肺功能的指标之一。

Objective To evaluate volumetric HRCT (VHRCT), MIP and MinIP in the diagnosis of diffuse lung diseases (DLD).Materials and Methods VHRCT scan covering one or several pulmonary ROI, MIP and MinIP reconstruction were performed in 112 patients with DLD. Pulmonary function tests were carried out in 46 patients within 3 weeks after VHRCT scanning. The diagnosis in all patients was proved with pathology or clinical data.Results (1) The sensitivity of MIP in detecting pulmonary nodules, “ground glass” opacity and the thickened bronchovascular bundles was 100%, the same was the sensitivity of MinIP in detecting pulmonary hypoattenuation. The confidence level of diagnosis for DLD was gradually improved with the images of the spiral CT alone, of spiral CT and VHRCT together, and of all four imaging techniques (P<0.001). The diagnostic correctness for patients with confidence level 3 was up to 31.25% (35/112), 58.93% (66/112) and 79.46% (89/112), respectively, with both P1 and P2 <0.001. The variability between different observers was gradually decreased, with the Kappa value being 0.621, 0.739 and 0.809 respectively. (2) Hypoattenuation scores on MinIP images alone were positively correlated with comprehensive hypoattenuation scores on spiral CT scans and MinIP images (r=0.867, P<0.001). The above two scores bore a close relationship to the results of pulmonary function tests (P<0.05). Conclusion VHRCT scanning, MIP and MinIP provide important information very useful in the diagnosis of DLD, thus, it should be regarded as an effective supplement to spiral CT scan. In detecting pulmonary hypoattenuation MinIP is more sensitive than other imaging formats, hypoattenuation score on MinIP images is closely correlated with the results of pulmonary function tests, which can be sued as an index to predict pulmonary function in patients with DLD.