Focal area of ground-glass opacity and ground-glass opacity predominance on thin-section CT: Discrimination between neoplastic and non-neoplastic lesions

AIM: To reveal differences in thin-section computed tomography (CT) findings between lung neoplastic lesions and non-neoplastic lesions, which showed a focal area of ground-glass opacity or ground-g[ass opacity predominance. MATERIALS AND METHODS: A total of 82 focal areas of ground-glass opacity and ground-glass opacity predominance, consisting of 38 neoplastic and 44 nonneoplastic lesions, were assessed retrospectively regarding their thin-section CT findings. RESULTS: The frequency of wholly welt-defined margin (p=0.001), spiculation (p=0.019), pleural indentation (p=0.016), air bronchograms (p=0.027), air-containing space (p=0.004) was significantly higher in neoplastic lesions than in non-neoplastic Lesions. Thirty-four of 38 (89%) neoplastic lesions were well-defined in more than 50% of the circumference, of which nine had an air-containing space other than air bronchogram, whereas only one non-neoptastic lesion had these features. CONCLUSION: A focal area of ground-glass opacity or ground-g[ass opacity predominance with a well-defined margin and air-containing space is more likely to be a neoplasm. (C) 2005 Published by Elsevier Ltd on behalf of The Royal College of Radiologists.