Tuberc Respir Dis.  2009 Apr;66(4):288-294.

The Correlation of Dyspnea and Radiologic Quantity in Patients with COPD

• Jung EJ
• Kim YK
• Lee YM
• Kim KU
• Uh ST
• Kim YH
• Kim DJ
• Park CS
• Hwang JH

Abstract

BACKGROUND
A lung hyperinflation, or air trapping, caused by expiratory flow-limitation contributes to dyspnea in patients with chronic obstructive pulmonary disease (COPD). Forced expiratory volume in 1 second (FEV1) has served as an important diagnostic measurement of COPD, but does not correlate with patient-centered outcomes such as dyspnea. Therefore, this study was performed to investigate the role of radiologic quantity in evaluating the dyspnea in patients with COPD by measuring lung hyperinflation in chest x-ray and high resolution chest tomography (HRCT).
METHODS
Fifty patients with COPD were enrolled in this study. Their subjective dyspnea score (modified Borg scale dyspnea index), spirometry, and lung volume were measured. Simultaneous hyperinflations of chest x-ray score ("chest score") and degree of emphysema of HRCT ("HRCT score") were measured. The "chest score" were composed of lung length, retrosternal space width, and height of the arc of the diaphragm and "HRCT score" were composed of severity and extent of emphysema.
RESULTS
The mean age of patients was 69 years old and their mean FEV1 was 51.7%. The Borg score significantly correlated with parameters of spirometry and lung volume, including FVC, FEV1, FEV1/FVC, RV, RV/TLC, and DLCO. The Borg score correlated well with "HRCT score", but did not correlate with "chest score". Also, the Borg scale correlates inversely with body mass index.
CONCLUSION
The quantity of emphysema on chest HRCT may serve as an objective marker of dyspnea in patients with COPD.

Keyword

Dyspnea; Chronic obstructive pulmonary disease; Radiology

MeSH Terms

Diaphragm
Dyspnea
Emphysema
Forced Expiratory Volume
Humans
Lung
Pulmonary Disease, Chronic Obstructive
Spirometry
Thorax

Figure

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  Figure 1 Radiographic measurements of lung hyperinflation. (A) Lung length - distance from the tubercle of the rib to the top of the dome of the right diaphragm. (B) Retrosternal space width - horizontal distance from the posterior aspect of the sternum 3 cm below the sternoclavicular junction to the anterior margin of the aorta measured on the lateral film. (C) Right diaphragm arc on the lateral film - measurement of a line normal to the curve at its apex and normal to a line drawn between the posterior and anterior costophrenic angles.

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  Figure 2 The correlation of Borg scale with chest score. A correlation was not found between two parameters (r= -0.136, p=0.345).

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  Figure 3 The Borg scale well correlated with HRCT score.

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  Figure 4 The Borg scale well inversely correlated with body mass index (BMI).

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