Table 1. Patient Characteristics.

Characteristic
Gender	Male	54 (50.5%)
	Female	53 (49.5%)
Age		58.9±11.73 (24∼83)
Smoking history		40 (37.4%)*
Malignancy history		9 (8.4%)
Imaging characteristic	Maximal diameter (cm)	1.93±0.63 (0.5∼3.0)
	Located on Upper lobe	58 (54.2%)
	Spiculation	75 (70.1%)
	Lobulation	96 (89.7%)
	Calcification	7 (6.5%)

^*6 had quitted smoking for 1–20 years.