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

从1991年到1998年，通过螺旋CT对801人进行了肺癌二次筛查。801例中有82例出现肺结节（原发性肺癌24例，转移性肿瘤9例，良性病变49例）。为了确定筛查的诊断标准，我们分析了螺旋CT和HRCT的表现，并根据结果讨论了三种诊断标准方案。在直径小于5mm的结节中，以良性结节居多，且结节尺寸越大，恶性肿瘤增加越多。在原发性肺癌中，螺旋CT常发现分叶、多刺、胸膜压痕、血管受累（尤其是PV）和实性密度。这些CT表现多见于HRCT。在转移性肿瘤中，螺旋CT上病灶数量较多，HRCT上常可见实性密度和分叶。总之，我们建议在直径大于5mm的病例中，如果发现这些发现之一疑似恶性肿瘤，应进一步检查。对于直径小于5mm的结节，若见圆形、边界分明、边缘光滑，则怀疑为良性结节，需观察。

From 1991 to 1998, the secondary screening for lung cancer by helical CT has been performed in 801 persons. In 82 out of 801 cases, pulmonary nodules were depicted (primary lung cancer : 24 cases, metastatic tumor 9 cases, benign lesion 49 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.