16层以上螺旋CT对诊断孤立性肺结节的合理应用分析

Rationality of 16 or more multi-slice helical CT utilization for solitary pulmonary nodule

目的 评价16层以上MSCT对诊断孤立性肺结节（〈3cm）的应用合理性。方法分析到该院会诊患者的院外胸部CT照片，选择使用16层以上MSCT机型和直径〈3cm孤立性肺结节的150例作为研究对象，记录院外CT片内常规重建层厚、有无靶重建、二维和三维重组应用情况、窗技术应用以及对比剂增强效果等。确定孤立性肺结节的胸部CT正确扫描方法，并与院外胸部CT扫描技术进行对比，评价院外MSCT胸部应用的合理性及正确诊断情况。结果92例采用16层CT机，54例采用64层CT机，4例为40层CT机。常规重建层厚选择9～10mm者59例，7～8mm者12例，5mm者79例。对病灶局部采用连续薄层（〈3mm）重建46例。9例CT片内仅有重组图像（MPR和VR），没有原始薄层轴而图像。在150例中，由于图像不满意而需重复扫描者53例（35．3％）；78例在该院经病理或临床确诊，其中院外诊断错误22例，在该院仅2例诊断错误。结论16层以上MSCT在孤立性肺结节的应用存在诸多不合理件，直接影响诊断，建议建立国内统一的胸部CT扫描标准。

Objective To analyze the rationality of 16 or more multi-slice helical CT （MSCT） utilization for solitary pulmonary nodule （SPN） （ 〈 3 cm ）. Methods One hundred and fifty consultant cases with SPN from 133 different hospitals, examined with 16 or more MSCT, were selected in this study. The reconstructed slice thickness of routine CT scan, thin slice reconstruction thickness, 2D or 3D reconstruction, window wide and level setting, contrast enhancement effect were recorded from consultant films. Thoracic CT scan criteria for SPN were proposed according to the scan guidelines at Stanford University and PubMed articles. The rationality of 16 or more MSCT utilization in other hospitals for SPN was analyzed by two radiologists compared with scan criteria. The diagnostic accuracy in other hospitals was evaluated according to the pathologic and treatment results in our hospital. Results Sixteen-MSCT was performed in 92 cases, 64-MSCT in 54 cases and 40-MSCT in 4 cases. In routine thoracic CT scan, 9-10 mm reconstructed slice thickness was selected in 59 cases, 7-8 mm thickness in 12 cases and 5 mm thickness in 79 cases. Consecutive thin slice thickness （ 〈 3 mm） was used for SPN only in 46 cases. Only MPR and VR were filmed in 9 cases without thin slice reconstructed axial images. 53 cases （35.3%） were rescanned in our hospital due to the unsatisfied image quality. Of 150 cases, 78 cases had pathologic or treatment results in our hospital and 22 cases （ 14. 7% ） were proved to he misdiagnosed in other hospitals, and only 2 cases were misdiagnosed in our hospital. Conclusion There are many irrationalities of 16 or more MSCT utilization in our country which influence the diagnostic accuracy of SPN. Unified thoracic CT scan criteria in our country are needed.