Simple X-ray versus ultrasonography examination in blunt chest trauma: effective tools of accurate diagnosis and considerations for rib fractures.

Simple radiography is the best diagnostic tool for rib fractures caused by chest trauma, but it has some limitations. Thus, other tools are also being used. The aims of this study were to investigate the effectiveness of ultrasonography (US) for identifying rib fractures and to identify influencing factors of its effectiveness. Between October 2003 and August 2007, 201 patients with blunt chest trauma were available to undergo chest radiographic and US examinations for diagnosis of rib fractures. The two modalities were compared in terms of effectiveness based on simple radiographic readings and US examination results. We also investigated the factors that influenced the effectiveness of US examination. Rib fractures were detected on radiography in 69 patients (34.3%) but not in 132 patients. Rib fractures were diagnosed by using US examination in 160 patients (84.6%). Of the 132 patients who showed no rib fractures on radiography, 92 showed rib fractures on US. Among the 69 patients of rib fracture detected on radiography, 33 had additional rib fractures detected on US. Of the patients, 76 (37.8%) had identical radiographic and US results, and 125 (62.2%) had fractures detected on US that were previously undetected on radiography or additional fractures detected on US. Age, duration until US examination, and fracture location were not significant influencing factors. However, in the group without detected fractures on radiography, US showed a more significant effectiveness than in the group with detected fractures on radiography (=0.003). US examination could detect unnoticed rib fractures on simple radiography. US examination is especially more effective in the group without detected fractures on radiography. More attention should be paid to patients with chest trauma who have no detected fractures on radiography.