Benign lung tumors are mostly round or oval in shape, surrounded by envelope, growing slowly, with few symptoms or found during physical examination, occasionally malignant; malignant lung tumors mostly grow faster, central type lung cancer symptoms appear earlier, tumors can occur distant metastasis, infiltration, systemic symptoms are obvious, there can be wasting and other wasting symptoms. Key points of lung imaging differentiation.
Benign tumour of the lung
Margins: clear, smooth and sharp.
Contour: few visible cut marks; and different from lobar signs.
Density: homogeneous or heterogeneous, moderately high; CT values: generally above 164 Hu; fatty hypodensity visible in some nodules.
Calcifications: frequent, laminar, speckled or plaque-like. Diffuse distribution or central distribution.
Cavitation: small crescentic or fissure-shaped cavities.
Bronchial inflation sign: seen.
Vascular collection sign: rare.
Peripheral structures: clear surrounding lung fields or satellite lesions, small patchy infiltrates visible on the chest wall side of some nodules.
Malignant tumour of the lung
Margin: dense, fine, short burrs, stiff and pompom-like.
Contour: finely and deeply lobulated, spine-like and uneven or serrated, resembling a mulberry.
Density: homogeneous or heterogeneous, moderately low. CT values are generally below 164 Hu.
Calcifications: rare, finely punctate or gravelly, eccentrically distributed.
Cavitation: irregular pattern of cavity lining, with visible wall nodules.
Bronchial inflation sign: seen.
Vascular collection sign: common.
Surrounding structures: clear surrounding lung fields, no satellite lesions; small patchy infiltrates are seen on the pleural side of some nodules.