TABLE 2.

Imaging Markers

	PAO2						ADC
	Single-breath			Multibreath			Single-breath		Multibreath
Subject	Global (Torr)	Heterogeneity* (Torr)	<40 or >160 Nonphysiol.†	Global (Torr)	Heterogeneity* (Torr)	<40 or >160 Nonphysiol.†	Global (cm2/s)	Heterogeneity* (cm2/s)	Global (cm2/s)	Heterogeneity* (cm2/s)
AS 1	116	43	61	69	35	52	0.356	0.118	0.391	0.097
AS 2‡	-	-	-	-	-	-	0.315	0.106	0.317	0.124
AS 3	73	42	102	85	36	89	0.320	0.109	0.328	0.108
AS 4	101	35	48	74	34	48	0.263	0.072	0.272	0.070
AS 5 ‡	-	-	-	-	-	-	0.204	0.099	0.205	0.111
Mean ± SD	97 ± 22	40 ± 4	70 ± 28	76 ± 8	35 ± 1	63 ± 23	0.292 ± 0.059	0.101 ± 0.017	0.303 ± 0.069	0.102 ± 0.02
COPD 1	106	49	117	73	36	103	0.547	0.143	0.598	0.157
COPD 2	105	42	69	86	34	44	0.396	0.109	0.414	0.119
COPD 3	114	39	33	90	33	33	0.328	0.107	0.329	0.124
COPD 4	85	38	50	76	30	32	0.396	0.111	0.402	0.135
COPD 5	145	48	101	106	42	92	0.269	0.072	0.264	0.119
Mean ± SD	111 ± 22	43 ± 5	67 ± 44	86 ± 13	35 ±4	56 ± 41	0.387 ± 0.104	0.108 ± 0.025	0.401 ± 0.125	0.131 ± 0.016
P (T ≤ t)	0.416	0.367	0.877	0.225	0.384	0.916	0.122	0.609	0.172	0.037

ADC, apparent diffusion coefficient; COPD, chronic obstructive pulmonary disease; SD, standard deviation.

^*Standard deviation.

^†Number of voxels with nonphysiologic values.

^‡The subject is excluded in statistical comparisons due to failed breathing protocol.