Fig. 2
From: Differentiation of pulmonary solid nodules attached to the pleura detected by thin-section CT
SPAN with narrow or broad basement and type I of nodule-pleura relationship. a A 59-year-old man with left lower lobe lobulated SPAN which is confirmed as invasive adenocarcinoma. On the axial CT image with a maximum section of the nodule, R-length is defined as the ratio of the length of the nodule-pleura interface (red dashed line) to nodule size (blue dashed line). Its R-length is 0.36, which indicates a narrow basement. The nodule-pleura relationship is type I (nodule clinging to the normal pleura without extrapleural fat infiltration). b, c A 49-year-old man with right lower lobe SPAN which is confirmed as a benign lesion during follow-up. On the axial CT image with a maximum section of the nodule, its R-length is 1, which indicates a broad basement, and the nodule-pleura relationship is also type I