Skip to main content

Table 4 Lung motion velocity in tidal and forced inspiration and expiration phases among normal, chronic obstructive pulmonary disease (COPD) mild, and COPD severe groups

From: Vector-field dynamic x-ray (VF-DXR) using optical flow method in patients with chronic obstructive pulmonary disease

 

Lung motion velocity, median [interquartile range] (mm/s)

p values

(1) Normal (n = 47)

(2) COPD mild (n = 14)

(3) COPD severe (n = 22)

Alla

(1) vs (2) b

(2) vs (3) c

(1) vs (3) d

Right

 Tidal inspiration

16.8 [14.1, 19.9]

28.5 [21.7, 33.9]

25.1 [17.8, 31.3]

< 0.001**

< 0.001**

0.432

0.002**

 Tidal expiration

-14.5 [-18.4, -11.5]

-22.1 [-28.6, -19.2]

-15.6 [-25.2, -12.9]

< 0.001**

< 0.001**

0.059

0.206

 Forced inspiration

28.8 [22.5, 36.2]

24.1 [20.7, 37.3]

36.3 [25.3, 47.6]

0.107

0.502

0.214

0.214

 Forced expiration

-23.6 [-31.4, -18.5]

-32.9 [-46.6, -20.8]

-27.0 [-40.3, -21.9]

0.093

0.227

0.810

0.227

Left

 Tidal inspiration

20.8 [17.7, 23.4]

23.9 [22.3, 29.1]

24.6 [19.9, 26.2]

0.012*

0.018*

0.642

0.089

 Tidal expiration

-19.3 [-21.5, -16.4]

-25.5 [-30.9, -22.0]

-18.4 [-23.8, -15.0]

0.009**

0.004**

0.038*

0.934

 Forced inspiration

31.2 [27.4, 36.5]

28.3 [23.5, 38.6]

31.6 [26.1, 39.0]

0.678

1.000

1.000

1.000

 Forced expiration

-27.1 [-33.5, -22.0]

-33.8 [-43.6, -27.7]

-27.8 [-39.0, -21.1]

0.171

0.166

0.479

0.650

  1. Lung motion velocity downward is defined as positive direction. *p value ≤ 0.05. **p value ≤ 0.01. ap values are for the comparison of all groups by one-way analysis of variance on ranks. Post-hoc multiple comparison was analyzed with Holm-Bonferroni method. bp values are for the comparison between normal and COPD mild groups. cp values are for the comparison between COPD mild and severe groups. dp values are for the comparison between normal and COPD severe groups