Chest Dynamic-Ventilatory Digital Radiography in Chronic Obstructive or Restrictive Lung Disease

Figures & data

Table 1 Characteristics of Participants Based on Ventilatory Disorders

Ventilatory Pattern Group	Control	Obstructive Disorder			Restrictive Disorder
		Mild AL	Moderate AL	Severe AL	Moderate RD	Severe RD
Number	104	108	25	6	14	16
Gender (Female/male)	40/64	31/77	10/15	0/6	5/9	4/12
Age (years)	66.7 ± 9.5	71.9 ± 7.1	70.8 ± 4.4	64.3 ± 16.0	69.9 ± 9.8	59.8 ± 13.7
Height (m)	1.62 ± 0.09	1.62 ± 0.09	1.63 ± 0.07	1.67 ± 0.08	1.60 ± 0.10	1.63 ± 0.08
BMI (kg/m^2)	22.9 ± 3.6	23.3 ± 3.4	23.0 ± 5.2	19.5 ± 2.7	23.5 ± 3.9	20.9 ± 3.1
Smoking history (BI)	800 (0–2350)	800 (0–2350)	1105 (0–5800)	900 (488–1400)	910 (0–1530)	920 (0–1110)
Pulmonary function
VC (%pred.)	110.7 ± 17.9	120.8 ± 15.5	99.8 ± 12.1	100.5 ± 11.2	71.3 ± 4.0	56.5 ± 5.9
FVC (% pred.)	110.2 ± 18.1	120.4 ± 15.4	99.4 ± 12.3	97.7 ± 10.0	71.0 ± 4.2	55.3 ± 6.9
FEV1 (% pred.)	116.2 ± 21.4	108.0 ± 20.0	67.2 ± 8.3	44.3 ± 4.2	85.5 ± 14.1	61.1 ± 6.9
FEV1/FVC ratio	0.78 ± 0.06	0.63 ± 0.06	0.51 ± 0.09	0.35 ± 0.06	0.84 ± 0.07	0.85 ± 0.08
MMEF (% pred.)	73.3 ± 26.1	32.5 ± 11.1	15.3 ± 6.1	9.5 ± 3.5	79.7 ± 46.5	54.2 ± 31.0
FRC (% pred.)	103.1 ± 20.0	110.4 ± 16.4	108.3 ± 23.7	118.9 ± 26.3	80.6 ± 15.6	65.6 ± 20.8
RV (% pred.)	106.1 ± 25.6	115.6 ± 21.0	133.0 ± 33.1	147.3 ± 24.1	87.7 ± 23.8	77.8 ± 42.3
TLC (% pred.)	103.7 ± 16.5	107.1 ± 16.7	106.2 ± 16.6	110.8 ± 14.2	74.7 ± 9.2	60.9 ± 12.9
RV/TLC ratio	0.36 ± 0.06	0.37 ± 0.05	0.44 ± 0.06	0.44 ± 0.07	0.41 ± 0.06	0.39 ± 0.13
DLco (% pred.)	64.4 ± 19.3	67.1 ± 19.5	56.2 ± 16.0	37.4 ± 23.6	36.8 ± 15.0	31.1 ± 9.2

Note: All the data except smoking history are presented as the means ± SD. Smoking history is presented as the median (range).

Abbreviations: AL, airflow limitation; BI, Brinkmann index; RD, restrictive disease; Mild AL, FEV₁ ≥ 80% of predicted; Moderate AL, 50% ≤ FEV₁ < 80% of predicted; Severe AL, FEV₁ < 50% of predicted; Moderate RD, 65% ≤ FVC < 80% of predicted; Severe RD, FVC < 65% of predicted.

Figure 1 Obstructive disorder is defined as FEV₁/FVC < 0.7. The degrees of severity of airflow limitation (AL) are defined as follows: mild airflow limitation, FEV₁ ≥ 80% predicted; moderate airflow limitation, 50% ≤ FEV₁ < 80% predicted; and severe airflow limitation, FEV₁ < 50% predicted. The restrictive pattern is defined as FVC < 80% predicted. The severity of restrictive disease (RD) is defined as follows: moderate restrictive disease, 65% ≤ FVC < 80% predicted; severe restrictive disease, FVC < 65% predicted. Participants with both FVC ≥ 80% predicted and FEV₁/FVC ≥ 0.7 were included in the control group. (A) Distribution of lung area_in/height in each type of ventilatory disorder. (B) Distribution of tracheal diameter change in each type of ventilatory disorder. Distribution of tracheal narrowing rate in each type of ventilatory disorder. (C) Distribution of diaphragmatic motion in each type of ventilatory disorder. (D) Distribution of lung area change rate in each type of ventilatory disorder. Lung area change rate represents the rate of change in the lung area due to respiratory motions. Lung area change rate: (lung area_ex – lung area_in)/lung area_in. Lung area_in: lung area at the time of maximal inspiration. Lung area_ex: lung area at the time of maximal expiration. *P < 0.05 compared to control by Mann–Whitney U-test.

Table 2 AUC, Cut-Off Value, Sensitivity, Specificity for Ventilatory Disorder

	AUC	Cut-Off	Se	Sp
Lung area_in/height*	0.88	203.8	0.77	0.88
Tracheal narrowing rate**	0.67	24.8	0.53	0.81
Tracheal diameter change**	0.63	5.14	0.38	0.83
Right diaphragmatic motion***	0.67	39.6	0.67	0.64
Left diaphragmatic motion***	0.70	38.4	0.61	0.79
Lung area change rate***	0.68	−0.23	0.53	0.83

Notes: The obstructive disorder was defined as FEV₁/FVC < 0.7. The restrictive disorder was defined as FVC < 80% of predicted. *For restrictive disorder. **For obstructive disorder. ***For moderate and more than moderate ventilatory disorders, including moderate airflow limitation, severe airflow limitation, moderate restrictive disease, and/or severe restrictive disease.

Abbreviations: AUC, area under the curve; Se, sensitivity; Sp, specificity; S_In, the lung area at the time of maximum inspiration.