Table 1.

Characteristics of NCNs reported on the baseline CT screen

CharacteristicsPercentage of NCNs (N = 11,779)
Nodule attenuation
 Soft tissue74.8
 Ground glass15.3
 Mixed4.3
 Other/unknown5.6
Nodule margins
 Smooth65.9
 Spiculated10.0
 Poorly defined19.9
 Unable to determine4.3
Nodule size (largest diameter)
 4–9 mm83.9
 10+ mm16.1
Nodule location
 Right upper lobe23.6
 Right middle lobe13.7
 Right lower lobe23.7
 Left upper lobe14.4
 Lingula4.3
 Left lower lobe19.7
 Other0.6

NOTE: All NCNs are 4+ mm.