The effects of emphysema on airway disease: correlations between multi-detector CT and pulmonary function tests in smokers.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation caused by emphysema and small airway narrowing. Quantitative evaluation of airway dimensions by multi-detector computed tomography (MDCT) has revealed a correlation between airway dimension and airflow limitation. However, the effect of emphysema on this correlation is unclear.


OBJECTIVE
The goal of this study was to determine whether emphysematous changes alter the relationships between airflow limitation and airway dimensions as measured by inspiratory and expiratory MDCT.


METHODS
Ninety-one subjects underwent inspiratory and expiratory MDCT. Images were evaluated for mean airway luminal area (Ai), wall area percentage (WA%) from the third to the fifth generation of three bronchi (B1, B5, B8) in the right lung, and low attenuation volume percent (LAV%). Correlations between each airway index and airflow limitation were determined for each patient and compared between patients with and without evidence of emphysema.


RESULTS
In patients without emphysema, Ai and WA% from both the inspiratory and expiratory scans were significantly correlated with FEV1. No correlation was detected in patients with emphysema. In addition, emphysematous COPD patients with GOLD stage 1 or 2 disease had significantly lower changes in B8 Ai than non-emphysematous patients.


CONCLUSIONS
A significant correlation exists between airway parameters and FEV1 in patients without emphysema. Emphysema may influence airway dimensions even in patients with mild to moderate COPD.
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: mis_misuzu@yahoo.co.jp.
Misuzu
M
Yahaba
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: chumito_03@yahoo.co.jp.
Naoko
N
Kawata
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: iesato_k@yahoo.co.jp.
Ken
K
Iesato
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: matsuyuki_future@yahoo.co.jp.
Yukiko
Y
Matsuura
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: sugiura@js3.so-net.ne.jp.
Toshihiko
T
Sugiura
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: daikasai6075@yahoo.co.jp.
Hajime
H
Kasai
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: yoliri@nifty.com.
Yoriko
Y
Sakurai
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: jirotera@chiba-u.jp.
Jiro
J
Terada
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: sakao@faculty.chiba-u.jp.
Seiichiro
S
Sakao
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: ytada@faculty.chiba-u.jp.
Yuji
Y
Tada
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: ntanabe@faculty.chiba-u.jp.
Nobuhiro
N
Tanabe
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: tatsumi@faculty.chiba-u.jp.
Koichiro
K
Tatsumi
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011656:Pulmonary Emphysema / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000379:methods*; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity; D013223:Statistics as Topic
Airway luminal area; Chronic obstructive pulmonary disease; Low attenuation volume percentage; Multi-detector computed tomography; Wall area percentage