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

1991~1996年，应用螺旋CT对597例肺癌患者进行了二次筛查。597例中55例显示肺结节，其中原发肺癌14例，转移瘤8例，良性病变33例。为了确定筛查的诊断标准，分析了螺旋CT和HRCT的表现，并根据结果讨论了三种诊断标准：直径小于5 mm的结节，大多数是良性的，结节越大，恶性肿瘤越多。在原发肺癌中，螺旋CT多见分叶、毛刺、胸膜凹陷、血管受累(尤其是PV)和实性密度，HRCT多见这些征象，转移性肺癌多见螺旋CT，而HRCT多见实性密度和分叶。直径小于5 mm的结节，若呈圆形，边界清楚，边缘光滑，则怀疑为良性结节，需观察。

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.