PURPOSE: Alteration in pulmonary vessel structure and function are highly prevalent in patient with chronic obstructive pulmonary disease (COPD). Pulmonary hypertension caused by vascular abnormalities is one of the factors associated with survival in COPD patients. Recently, it was reported these change observed in early stage of COPD. However, relationship of structural change and severity of COPD has not been assessed. We purposed to quantify cross-sectional area of small pulmonary vessels (CSA) and low attenuation area (LAA) in COPD using inspiratory and expiratory multi-detecter row CT (MDCT) scans and analyze the relationship between airflow limitation and these parameters.
METHODS: fifty consecutive patients with COPD were underwent 64-MDCT and pulmonary function tests (PFTs). Using a semiautomatic image-processing program (Image J Version 1.39), the whole lung field and LAA were segmented. We measured CSA less than 5mm2 and 5-10mm2, and calculated the percentage of the total CSA and LAA for the lung area (%CSA<5, %CSA5-10, LAA%, respectively). Then, we assessed the relationship between these parameters and PFTs.
RESULTS: %CSA<5 had inverse correlation with FEV1/FVC and FEV1 (%predicted). The correlation coefficients of %CSA<5 in inspiratory CT with FEV1/FVC and FEV1 (%predicted) were -0.49 (p <0.001) and -0.32 (p <0.05), respectively. The correlation coefficients of %CSA<5 ratio in expiratory CT with FEV1/FVC and FEV1 (%predicted) were -0.57 (p <0.001) and -0.44 (p <0.01), respectively. %CSA correlated to FEV1/FVC and FEV1 (%predicted) especially in expiratory CT.
CONCLUSIONS: This study suggests that %CSA can correlate with the severity of airflow limitation.
CLINICAL IMPLICATIONS: %CSA may help to predict severity of COPD.
DISCLOSURE: The following authors have nothing to disclose: Yukiko Matsauura, Naoko Kawata, Toshihiko Sugiura, Noriyuki Yanagawa, Koichiro Tatsumi
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