Table 2.

CT diagnosis and differential diagnosis of PPP

	PPP	Peripheral lung cancer	Tuberculoma	Nodular focal organizing pneumonia
Lobule	Superficial lobe	Deep lobules	No lobule	No lobule
Rim	Fine burr shadow	Short hard burrs	Long burrs, satellite lesions	Peripheral visible burrs
Density	Relatively uniform density, occasionally empty	Most uneven, jagged hole in the inner wall	Calcification, hollow with smooth inner wall	Uneven density, pus cavity
Enhanced CT scan	Moderate uniform reinforcement	Obvious strengthening	No or light enhancement	Uniform or delayed enhancement
Pleural	Pleural retraction	Subpleural focal fatty infiltration	Pleural thickening/calcification	Adjacent pleural thickening