High-resolution computed tomography evaluation of peripheral airways in asthma patients: comparison of focal and diffuse air trapping.
BACKGROUND
Air trapping evaluated in high-resolution computed tomography (HRCT) reflects changes in small bronchi. We simultaneously evaluated focal and diffuse air trapping in asthmatic patients.


OBJECTIVE
(1) To evaluate air trapping and bronchial wall thickness in asthmatics. (2) To estimate the relationship between air trapping and bronchial wall thickness, pulmonary function tests (PFTs), age, gender and asthma severity. (3) To compare air trapping between subgroups of asthmatic patients with normal FEV(1) % pred. and FEV(1)/FVC % and controls. (4) To compare air trapping and bronchial wall thickness between aspirin-induced asthmatics (AIA) and aspirin-tolerant asthmatics (ATA).


METHODS
Both groups (asthmatics and controls) included 30 patients. All patients underwent HRCT and PFTs.


RESULTS
Focal (p < 0.0001) and diffuse (p = 0.0004) air trappings and bronchial wall thickness (T: p < 0.0001; T/D: p < 0.0001; WA%: p < 0.0001) were significantly greater in asthmatics. Focal and diffuse air trappings were inversely correlated (p = 0.021). Diffuse air trapping correlated with bronchial wall thickness: T/D (p = 0.047), T (p = 0.037), and WA% (p = 0.048). There was a significant difference in the extent of focal air trapping between a subgroup of asthmatics with normal FEV(1) % pred. and FEV(1)/FVC % and controls (p < 0.0001). There were no significant differences in focal (p = 0.095) and diffuse air trapping (p = 0.186) and bronchial wall thickness (T: p = 0.086; T/D: p = 0.428; WA%: p = 0.428) between AIA and ATA patients.


CONCLUSIONS
Both focal and diffuse air trappings provide valuable diagnostic information and therefore deserve to be estimated. The lack of significant differences in air trapping and bronchial wall thickness between AIA and ATA patients needs further investigation.
Mikos
Magdalena
M
Division of Pulmonology, 2nd Department of Medicine, School of Medicine, Jagiellonian University, Cracow, Poland. mmikos@vp.pl
Grzanka
Piotr
P
Sladek
Krzysztof
K
Pulka
Grazyna
G
Bochenek
Grazyna
G
Soja
Jerzy
J
Nizankowska-Mogilnicka
Ewa
E
Szczeklik
Andrzej
A
D000328:Adult; D000367:Age Factors; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D001241:Aspirin / Q000009:adverse effects; D001249:Asthma / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D001980:Bronchi / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012737:Sex Factors; D014057:Tomography, X-Ray Computed
D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin