Abstract:

Objective To investigate the morphologic characteristics of pulmonary multiple nodules (PMN) on chest computed tomography (CT).Methods Fifty-three patients from the Beijing Shijitan Hospital with PMN were retrospectively reviewed, including 19 cases with pulmonary tuberculosis, 23 cases with pulmonary metastasis, 5 cases with chronic pulmonary inflammation and 6 cases with diffuse lymphangiomatosis. The CT morphologic characteristics of PMN in the above four diseases were analyzed.Results 68.4% (13/19) of pulmonary tuberculosis patients and 78.3% (18/23) of pulmonary metastasis patients possessed PMN with maximum diameter ranging from 10 mm to 20 mm, while 60% (3/5) of chronic pulmonary inflammation patients and 60.0% (3/6) of diffuse lymphangiomatosis patients were detected PMN with maximum diameter ranging from 3 mm to 8 mm. The CT findings of chronic pulmonary inflammation group showed that there was no calcification and cavity in the nodules, 79.3% (69/87) cases had nodules with smooth edge and no lobule septum, 41.3% (36/87) cases had pleural thickening and adhesion adjacent to the lesions. The rates of no lobule septal nodule with smooth edge, calcification, cavity, and adjacent pleural thickening and adhesion in pulmonary tuberculosis group were 82.1% (128/156), 55.1% (86/156), 27.6% (43/156), and 45.5% (71/156), respectively. For the pulmonary metastasis group, the rates of no lobule septal nodule, calcification, cavity, and adjacent pleural thickening and adhesion were 60.0% (369/615), 3.7% (23/615), 18.0% (111/615), and 18.5% (114/615), respectively. Compared to the pulmonary metastasis group, the rates of no lobule septal nodule in chronic pulmonary inflammation group and pulmonary tuberculosis group were statistically significant (χ ²=47.613, P=0.000; χ ²=88.095, P=0.000). There were statistical differences in calcification and cavity between the pulmonary tuberculosis group and pulmonary metastasis group (χ ²=270.707,P=0.000; χ ²=7.048,P=0.008). Compared to the pulmonary metastasis group, the rates of adjacent pleural thickening and adhesion in chronic pulmonary inflammation group and pulmonary tuberculosis group were statistically significant (χ ²=23.670,P=0.000; χ ²=49.650,P=0.000). The types of cavity in pulmonary metastasis group were as follows: the incidence of vacuolar cavity, 34.2% (38/111) > cystic cavity, 26.2% (29/111) > small annular cavity, 22.5% (25/111) > irregular cavity 17.1% (19/111). In addition, all the vacuolar cavities were only detected in the pulmonary metastasis of adenocarcinoma and 78.9% (30/38) of vacuolar cavity nodules possessed characteristic of lobule septal and rag margin. All the five patients in chronic inflammation group showed nodules with poorly defined margins, surrounded by flaky infiltrating shadows and stripe shadows. The nodules of diffuse lymphangiomatosis showed a diffuse or multifocal growth pattern, involving multiple regions with multiple cystic lesions of unequal size, and the pulmonary nodules were smooth in margin and homogeneous in density. Conclusion When the pulmonary tuberculosis, pulmonary metastasis, chronic pulmonary inflammation, and diffuse lymphangiomatosis showed PMN, the specific visual characteristics on CT, such as lesion size, location, morphology, edge, density and adjacent tissue have important value in the differential diagnosis of the above four diseases.

Key words: Multiple pulmonary nodules, Tomography, X-ray computed, Diagnostic imaging, Diagnosis, differential