【Objective】 To investigate the relationship of airway dimensions measured by multi-slice spiral CT (MSCT) with lung function in the patients with chronic obstructive pulmonary disease (COPD). 【Methods】 Forty subjects were divided into two groups: COPD group with 25 patients and control group with 15 healthy subjects. All the subjects underwent 64-slice spiral CT scans at chest and pulmonary function test. The dimensions of apical bronchus of the right upper lobe in the CT images were measured

which included the following parameters: the ratio of airway wall thickness (T) and square root of body surface area (T/√BSA)

the ratio of airway luminal area (Ai) and BSA (Ai/BSA). The following parameters were calculated by the preceding ones: the ratio of the outer area of the bronchus (Ao) and BSA (Ao /BSA)

the ratio of T and the total diameter of the bronchus (T/D)

the percentage of airway wall area to Ao (WA%). The relationship between airway dimensions and lung functions in COPD patients were analyzed.【Results】 There were significant differences between COPD group and control group in T/√BSA[(1.5±0.3) vs (1 ± 0.2) mm/m

P < 0.01]

T/D[(0.3 ± 0.05) vs (0.2 ± 0.02)

P < 0.01]

Ai/BSA[(4 ± 1.7) vs (5.6 ± 2) mm/m

P = 0.01]

WA%[(81.1 ± 8.1) vs (72.2 ± 4.1)%

P < 0.01]

ventilation function(P < 0.05)

small airway function (P ≤ 0.001)

total lung capacity (P < 0.05)

residual volume(P < 0.01)

airway resistance (P < 0.01) and diffusion function(P < 0.01). T/√BSA and T/D correlated negatively with ventilation function

small airway function

vital capacity (VC)(r = -0.724 ~ -0.400

P < 0.05) and positively with residual volume and airway resistance (r = -0.378~ -0.578

P < 0.05). T/D also correlated negatively with diffusion function (r = -0.485

P < 0.05). Ai/BSA correlated positively with ventilation function

small airway function and VC(r = -0.410 ~ -0.625

P < 0.05). Ao/BSA correlated negatively with ventilation function(r = -0.425

P < 0.05) and positively with residual volume (r = -0.497

P < 0.05). WA% correlated negatively with ventilation function

small airway function and VC(r = -0.729 ~ -0.445

P < 0.05) and positively with residual volume and airway resistance(r = 0.408 ~ 0.488

P < 0.05). 【Conclusion】 Airway dimensions measured by MSCT

among which the T/√BSA

T/D

Ai/BSA and WA% correlated strongly with lung functions

provided large amount of information about the airway abnormality in COPD.