Nodule size in the studies examined by McWilliams et al was ≥1 mm.

† A spiculated nodule has linear strands (coarse ≥ 2 mm thick, fine < 2 mm thick) extending from the nodule into the lung parenchyma but not extending to the pleura.²

References

1. McWilliams, A. et al. Probability of Cancer in Pulmonary Nodules Detected on First Screening CT. N. Engl. J. Med. 369, 910–919 (2013).
2. Zwirewich, C. V., Vedal, S., Miller, R. R. & Müller, N. L. Solitary pulmonary nodule: high-resolution CT and radiologic-pathologic correlation. Radiology 179, 469–476 (1991).