Chest trauma X‑ray

Written by the X-Ray Atlas editorial team from the sources listed below · Medical review pending · Updated 24 October 2026 · Level: Intermediate

In major trauma, the chest X-ray is usually a supine AP film taken in the resuscitation room, as part of the primary survey. Its job is to find immediately life-threatening problems quickly, such as a large haemothorax or pneumothorax, and to guide tube placement, not to catalogue every injury. Many important injuries are invisible or easy to miss on a supine film, and in significant trauma a CT scan usually follows. This page works through the trauma film in order of threat: pleural air and blood, the chest wall, the lungs, the diaphragm and the mediastinum.

1. The trauma film in context

• Clinical diagnoses come first. Tension pneumothorax, massive haemothorax and cardiac tamponade are diagnosed and treated clinically; treatment must not wait for a film.
• Ultrasound (eFAST) in the resuscitation room is more sensitive than a supine film for pneumothorax and haemothorax, and detects pericardial fluid.
• CT is the definitive test in significant blunt trauma, and NICE (NG39, major trauma) supports whole-body CT in adults with major trauma when indicated. The chest X-ray should not delay it.
• Despite this, the film is quick, is often available first, and finds problems that need action now. Read it systematically, and check every tube and line on it: ETT, NG tube, chest drains and central lines.

2. Pneumothorax and haemothorax on a supine film

Pneumothorax

In a supine patient, air rises to the front and bottom of the chest, not to the apex. A visible pleural line may be absent. Look for:

• the deep sulcus sign: an abnormally deep, lucent costophrenic angle;
• an unusually sharp heart border or hemidiaphragm;
• hyperlucency of one hemithorax or of the upper abdomen on that side;
• the "double diaphragm" sign, where both the dome and the anterior part of the diaphragm are outlined.

A substantial proportion of pneumothoraces in supine trauma patients, quoted as up to about 30%, are occult on the chest X-ray and seen only on CT or ultrasound. [VARIES] A small occult pneumothorax can enlarge rapidly with positive-pressure ventilation. See pneumothorax.

Haemothorax

On a supine film, blood layers posteriorly, so there is no meniscus. It appears as a diffuse hazy veil over the hemithorax, with lung vessels still visible through it, sometimes with an apical cap. A large volume may be needed before it is visible. An air–fluid level suggests a haemopneumothorax. See pleural effusion.

3. Rib fractures and flail chest

• The chest X-ray misses many rib fractures, often quoted as up to about half. [VARIES] Dedicated rib views are rarely needed, because management depends on the complications and the patient's pain and breathing, not the count on the film.
• Trace every rib, including the posterior and lateral parts. Look for a step in the cortex, a lucent line, or overlying soft-tissue swelling and surgical emphysema.
• Fractures of the 1st–3rd ribs imply high-energy trauma: look for injury to the great vessels and brachial plexus.
• Fractures of the 9th–12th ribs should prompt a search for injury to the liver (right), spleen (left) and kidneys.
• Multiple rib fractures in older patients carry significant morbidity and mortality, from pneumonia and respiratory failure, even with no other injury.

Healed fractures show callus. Multiple fractures of different ages raise questions about falls, alcohol or abuse; in infants, posterior rib fractures are highly specific for non-accidental injury. See non-accidental injury.

4. Clavicle, sternum, scapula and spine

• Clavicle: about 80% of fractures are in the middle third. See shoulder and clavicle fractures.
• Sternum: often invisible on the frontal film; best seen on a lateral, or CT. Associated with blunt cardiac injury.
• Scapula: a marker of high-energy trauma, often missed because attention is on the lungs.
• Thoracic spine: look at vertebral alignment and the paraspinal lines; a widened paraspinal line can indicate a haematoma from a spinal fracture. See thoracolumbar spine fractures.
• Sternoclavicular dislocation, especially posterior, can compress the great vessels; it is difficult to see on a chest X-ray and needs CT.

5. Contusion and laceration

• Pulmonary contusion is bruising of the lung: patchy, non-segmental air-space opacity, usually beneath the site of impact, that does not respect lobar boundaries. It typically appears within about 6 hours of injury and clears over about 3–10 days. Opacity appearing later, or persisting longer, suggests aspiration, infection or ARDS instead.
• Pulmonary laceration is a tear in the lung, which may fill with air (a traumatic pneumatocele) or blood (a haematoma), forming a rounded lucency or opacity that may take weeks to resolve.

6. Diaphragmatic rupture

Traumatic rupture of the diaphragm is more common on the left, roughly 3:1, because the liver protects the right. It is often missed at first, and abdominal organs may herniate into the chest later. Signs include:

• an elevated, irregular or indistinct hemidiaphragm;
• bowel or stomach in the chest, with gas-filled loops above the expected diaphragm;
• an NG tube curling up into the left chest above the expected diaphragm;
• the collar sign: a waist where the herniating organ is squeezed through the defect (often seen on CT).

Positive-pressure ventilation can keep herniated organs in the abdomen and hide the injury. CT is the test, and a normal film does not exclude rupture.

7. The mediastinum and aortic injury

A widened mediastinum after high-energy deceleration should raise concern for traumatic aortic injury. The classic signs are a widened mediastinum, an abnormal aortic knob, opacification of the AP window, rightward deviation of the trachea and NG tube, depression of the left main bronchus, a widened right paratracheal stripe, a left apical cap and fractures of the upper ribs. Supine AP films exaggerate mediastinal width, and a normal film does not exclude aortic injury. CT angiography is the test. The details are in mediastinum and hila.

Also look for pneumomediastinum and surgical emphysema, which can indicate airway or oesophageal injury, and an enlarged globular heart (haemopericardium is better shown by ultrasound).

Red flags: act now

What to focus on, by role

Role	Priorities
Medical student	Supine signs of pneumothorax and haemothorax, the meaning of upper and lower rib fractures, and the aortic injury signs.
Nurse	Recognise deterioration after chest injury, especially in older patients with rib fractures; pain control and breathing support matter.
Junior doctor	Read the supine film systematically, check every tube and line, and do not let a reassuring film delay CT in high-energy trauma.
Radiographer	Supine trauma technique, full coverage of both costophrenic angles and apices, and minimising rotation in difficult conditions.
Advanced / FRCR	Subtle supine signs, aortic and diaphragmatic injury, and correlation with trauma CT.

Practise on real chest X-rays →

References

1. American College of Surgeons. Advanced Trauma Life Support (ATLS), 10th edition. 2018.
2. NICE. Major trauma: assessment and initial management (NG39). nice.org.uk
3. Radiopaedia. Flail chest. radiopaedia.org
4. Roberts ME, et al. British Thoracic Society Guideline for pleural disease. Thorax 2023;78(Suppl 3):s1–s42. thorax.bmj.com
5. Royal College of Radiologists. iRefer. irefer.org.uk

For education only. Not a substitute for a formal report, senior review or your local policy. Never use this page to make decisions about a real patient.