Diagnostic Utility of Supine Chest Radiographs for Pleural Effusion.

Accession number;01A0234676
Title;Diagnostic Utility of Supine Chest Radiographs for Pleural Effusion.
Author;MATSUMOTO JUN'ICHI(St. Marianna Univ.)   KURIHARA YASUYUKI(St. Marianna Univ.)   
Journal Title;Japanese Journal of Medical Imaging
Journal Code:X0613A
ISSN:0289-0925
VOL.19;NO.5;PAGE.250-258(2000)
Figure&Table&Reference;FIG.7, TBL.4, REF.14
Pub. Country;Japan
Language;Japanese
Abstract;Objective. To assess the diagnostic utility of supine chest radiograph for pleural effusion. Materials and Methods. Eighty-three supine chest radiographs of 42 cases of suspected pleural effusion were studied retrospectively. Supine chest radiographs and subsequent thoracic CT scans were obtained within 24 hours (the average period between examinations was 2.8 hours) in all cases. First, we reviewed the supine chest radiographs without knowledge of the CT findings to evaluate the following 7 radiographic signs: (1) blunt costophrenic angle; (2) increased homogeneous density of the hemidiaphragm; (3) loss of the normal silhouette of the hemidiaphragm; (4) decreased visibility of the lower-lobe vascularity below the level of the hemidiaphragm, (5) apical capping; (6) thickening of the right minor fissure; and (7) obliteration of the descending aortic border. Then sensitivity, specificity, and accuracy of each sign of pleural effusion as well as of"clinically significant"effusion, in which the maximum anteroposterior thickness on the CT scans was over 2 cm, were assessed the based on the results of confirmatory thoracic CT scans. Results and Conclusion. The sensitivity, specificity, and accuracy of the supine chest radiograph for right-sided pleural effusion was 29.6%, 93.8%, and 62.9%, respectively, and for left-sided effusion, those were 53.9%, 85.8%, and 63.9%, respectively. The blunt costophrenic angle for right-sided effusion, and the loss of the normal silhouette of the hemidiaphragm for left-sided effusion were relatively reliable signs. On supine chest radiographs, a single positive sign can suggest the possibility of pleural effusion, although a thick minor fissure and decreased visibility of the lower-lobe vascularity in the case of right-sided effusion and obliteration of the descending aortic border and decreased visibility of the lower-lobe vascularity in the case of left-sided effusion were relatively frequently false positive.... (author abst.)