What is the best initial X-ray (X-ray) for a patient with posterior chest pain following a fall?

Best Initial X-ray for Posterior Chest Pain Following a Fall

A portable anteroposterior (AP) chest radiograph is the best initial X-ray for a patient with posterior chest pain following a fall, as it serves as the first-line trauma series imaging to screen for immediately life-threatening findings such as pneumothorax, significant mediastinal injury, and to confirm line placement. 1

Initial Imaging Approach

• Portable AP chest X-ray is the standard initial imaging in the trauma series for patients with blunt chest trauma, regardless of hemodynamic stability 1
• This view evaluates for tension pneumothorax, hemothorax, rib fractures, and mediastinal widening that require immediate intervention 1
• The ACR Appropriateness Criteria for Major Blunt Trauma explicitly recommends trauma series radiographs (chest and pelvis) as the initial workup for stable patients with blunt trauma 1

When to Add Lateral View

• Consider adding a lateral chest X-ray if the AP view is abnormal or clinical suspicion remains high, as lateral views can detect posterior abnormalities that may be missed on AP alone 2, 3
• Lateral views are particularly useful for visualizing posterior pleural-based opacities, posterior rib fractures, and retrosternal injuries 2
• However, in the acute trauma setting, the lateral view is not part of the standard initial trauma series and should be obtained selectively 1

Critical Next Steps Based on Initial X-ray

• If the chest X-ray is abnormal in the setting of trauma, proceed directly to CT chest with IV contrast, as patients with abnormal chest radiographs have clinically significant rates of major injury on CT 1
• CT chest with IV contrast has greater sensitivity for detecting visceral organ and vascular injury compared to noncontrast CT and should be primarily considered unless absolutely contraindicated 1
• Falls from height >15 feet warrant consideration of whole-body CT regardless of initial chest X-ray findings, as this mechanism meets criteria for high-energy trauma 1

Common Pitfalls to Avoid

• Do not rely solely on a normal AP chest X-ray to exclude significant injury, as portable supine AP radiographs have substantial limitations and miss up to 35% of significant chest injuries that are later detected on CT 3, 4
• Pneumothorax is particularly difficult to detect on supine AP films, and posterior rib fractures may not be visible 3
• In elderly patients or those with osteoporosis, maintain a lower threshold for CT imaging even with a normal chest X-ray, as occult rib fractures are common and can lead to complications 5

Specific Clinical Context Considerations

• If the patient is hemodynamically stable with normal physical examination and normal chest X-ray, clinical judgment determines whether further imaging is needed 4
• If posterior chest pain persists despite normal AP chest X-ray, strongly consider CT chest, as posterior injuries (scapular fractures, posterior rib fractures, thoracic spine injuries) are poorly visualized on AP views 2, 3
• Obtain concurrent ECG and cardiac troponin if there is any concern for blunt cardiac injury, as normal values effectively exclude significant cardiac trauma 6