What we should expect from a lateral chest radiograph.

Abstract

We reviewed 400 cases whose P-A and lateral chest radiographs were used. These were divided into three groups. Group A was composed of 235 cases of normal radiographs. This group was used to evaluate the incidence of visibility of some anatomic structures on a lateral radiograph. Group B consisted of 143 cases with various diseases including pleural effusion (20 cases), peri-diaphragmatic lesions (15 cases), abscess (12 cases), emphysema (20 cases), lung tumor (15 cases), mediastinal tumor (10 cases), obstructive atelectasis (16 cases), infiltrative pattern (15 cases), and pneumonia (20 cases). This group was used to evaluate what information the lateral view could add to an abnormal chest P-A radiograph. Group C had 22 cases with additional findings on the lateral view which were not seen on the chest P-A radiographs. This group was used to evaluate the applicability of sings of thickening of the posterior tracheal band, thickening of the posterior wall of the bronchus intermedius and posterior displacement of the left main bronchus in the diagnosis of specific diseases. The results showed A) there was no difference in the incidence of visibility of anatomic structures evaluated in this study on the right and the left lateral view. The visible incidence of these structures in 235 cases was 97% for the posterior tracheal band, 45% for the right upper lobe bronchus orifice, 83% for the left upper lobe bronchus orifice, 70% for the inferior vena cava, 92% for the posterior wall of the bronchus intermedius, 87% for the aorta, 97% for the right pulmonary artery, 71% for the left pulmonary artery, 69% for stomach air and 99% for the tracheal air column. B) unless the diagnosis could not be reached on the chest P-A radiograph or localization of the lesion was expected, the lateral view should be ordered only for patients with lesions of the peridiaphragm, mediastinum, hilum, midline, middle or lingual lobe, sternum, retrosternum or spine. C) the high incidence of visibility of the posterior tracheal band, posterior wall of the application of these signs available for diagnosis of specific diseases.