Research for Confirming the Diagnostic Criteria and the Diagnostic Methods of Pulmonary Nodules Depicted by Lung Cancer Screening Using Helical CT.

1991 ~ 1996年对597例肺癌患者进行了螺旋CT二次筛查。597例中55例显示肺结节（原发性肺癌14例，转移瘤8例，良性病变33例）。通过对螺旋CT和HRCT表现的分析，提出了3种诊断标准方案：直径小于5 mm的结节以良性为主，直径越大，恶性肿瘤越多。在原发性肺癌的病例中，分叶，毛刺，胸膜凹陷，血管受累螺旋CT常表现为肺结节（尤其是肺静脉）和实性密度，而HRCT多表现为实性密度，转移瘤螺旋CT仅表现为数目较多，而HRCT多表现为实性密度和分叶影。建议在直径大于5 mm的病例中，如有上述表现之一怀疑恶性肿瘤，应作进一步检查。对于直径小于5 mm的结节，如果结节形状圆形、边界清楚、边缘光滑，则怀疑为良性结节，需要进行观察。

From 1991 to 1996, the secondary screening for lung cancer by helical CT has been performed in 597 persons. In 55 out of 597 cases, pulmonary nodules were depicted (primary lung cancer : 14 cases, metastatic tumor : 8 cases, benign lesion : 33 cases). To confirm the diagnostic criteria for the screening, these helical CT findings and HRCT findings were analyzed, and from the results, three plans for diagnostic criteria were discussed.In cases of nodules smaller than 5mm in diameter, the majorities were benign, and the larger nodular size was, the more malignant tumor was increased. And in cases of primary lung cancer, lobulation, spiculation, pleural indentation, vascular involvement (especially PV) and solid density were often found in helical CT.These CT findings were more often found in HRCT.In cases of metastatic tumor, it was only larger number of the lesions in helical CT,but in HRCT,solid density and lobulation were often found.In conclusion, it was suggested that in cases of larger than 5mm in diameter, if one of these findings of suspected malignancy was seen, further examination should be done. In cases of nodules smaller than 5mm in diameter, if round shape, well difined and smooth margin were seen, the nodule was suspected to be benign, and observation would be needed.