Fig. 6

Low risk group patients Case 3 (3a, 3b, 3c) and Case 4 (4a, 4b, 4c): Case 3 was the solid nodule with spherical growth, obvious lobulation sign, vascular/cord shadows (fine arrow in 3a, 3c) and pleural indentation sign (star in 3b). Case 3 was the nodule with cavity or vacuole (round dot in 4a, 4b, 4c), no-spherical growth in the coronal plane, vascular/cord shadows and the growth angle of 45°