Time to Exhale: Additional Value of Expiratory Chest CT in Chronic Obstructive Pulmonary Disease

Table 3

Quantified CT parameters.

Parameter	Mean		SD		Range
	Inspiration	Expiration	Inspiration	Expiration	Inspiration	Expiration
Volume (ml)	5421	4417	1441	1279	2528 to 8541	1859 to 7792
MLD (HU)	−840	−803	48	66	−915 to −715	−910 to −663
FWHM (HU)	94	123	32	43	27 to 230	71 to 231
LAV (%)	12	9	15	14	0 to 50	0 to 50

MLD: mean lung density; FWHM: full width half max; LAV: low attenuation volume.