To diagnose<unk> , health professionals use clues from a physical examination, information about the event that caused the injury, and radiography. Laboratory findings may also be used; for example, arterial blood gasses may show insufficient oxygen and excessive carbon dioxide even in someone receiving supplemental oxygen. However, blood gas levels may show no abnormality early in the course of<unk> . X-ray A chest X-ray showing right sided (seen on the left of the picture)<unk>  associated with rib fractures and subcutaneous emphysema Chest X-ray is the most common method used for diagnosis, and may be used to confirm a diagnosis already made using clinical signs. Consolidated areas appear white on an X-ray film.<unk>  is not typically restricted by the anatomical boundaries of the lobes or segments of the lung. The X-ray appearance of<unk>  is similar to that of aspiration, and the presence of hemothorax or pneumothorax may obscure the<unk>  on a radiograph. Signs of<unk>  that progress after 48 hours post-injury are likely to be actually due to aspiration, pneumonia, or ARDS. Although chest radiography is an important part of the diagnosis, it is often not sensitive enough to detect the condition early after the injury. In a third of cases,<unk>  is not visible on the first chest radiograph performed. It takes an average of six hours for the characteristic white regions to show up on a chest X-ray, and the<unk>  may not become apparent for 48 hours. When a<unk>  is apparent in an X-ray, it suggests that the trauma to the chest was severe and that a CT scan might reveal other injuries that were missed with X-ray. Computed tomography A chest CT scan revealing<unk> s, pneumothorax, and pseudocysts Computed tomography (CT scanning) is a more sensitive test for<unk> , and it can identify abdominal, chest, or other injuries that accompany the<unk> . In one study, chest X-ray detected<unk> s in 16.3% of people with serious blunt trauma, while CT detected them in 31.2% of the same people. Unlike X-ray, CT scanning can detect the<unk>  almost immediately after the injury. However, in both X-ray and CT a<unk>  may become more visible over the first 24–48 hours after trauma as bleeding and edema into lung tissues progress. CT scanning also helps determine the size of a<unk> , which is useful in determining whether a patient needs mechanical ventilation; a larger volume of contused lung on CT scan is associated with an increased likelihood that ventilation will be needed. CT scans also help differentiate between<unk>  and<unk>  hematoma, which may be difficult to tell apart otherwise. However,<unk> s that are visible on CT but not chest X-ray are usually not severe enough to affect outcome or treatment. Ultrasound ultrasound image showing early<unk> , at this moment not visible on radiography. Lung swelling is seen as vertical white lines, the "B-lines".<unk>  ultrasound, performed at the bedside or on the accident scene, is being explored as a diagnosis for<unk> . Its use is still not widespread, being limited to facilities which are comfortable with its use for other applications, like pneumothorax, airway management, and hemothorax. Accuracy has been found to be comparable to CT scanning.
Pulmonary contusion
Hemothorax
Pulmonary hematoma
Diaphragmatic rupture
Urinothorax
Hemopneumothorax
Hydropneumothorax
Flail chest