Radiographic characteristics of asthma

A novel and interesting observation is that ribs go less sloped in asthma patients' radiograph than non-asthmatics people. The aim of this study was to investigate whether a smaller horizontal curve of the ribs is a special trait on chest radiograph of asthma patients.

A retrospective review of the chest radiographs of 57 cases of asthma who were admitted between January 2011 and February 2011, and 57 non-asthma patients was performed. Chest radiographs were examined and lines drawn horizontally through the middle point of the sixth rib, and to where the sixth rib reaches the thoracic cage. The angle between these two lines was defined as the angle of rib curve (ARC). The ARCs were then compared between groups using the Student's t-test.

The mean ARC was smaller in asthma patients than in non-asthma patients (10.7 ± 4.7° vs. 14.3 ± 4.7°, P < 0.0001). In the asthma group, the mean male ARC was smaller than the mean female ARC (8.4 ± 4.1° vs. 11.5 ± 4.7°, P = 0.026); however, there was no statistical difference in gender in the non-asthma group (P = 0.405).

This is the first study to report that the ribs of asthma patients are less sloped than in patients without asthma. This photographic trait may be helpful in daily practice for suspecting a diagnosis of bronchial asthma.