Which X-rays (X-radiation images) should be ordered for a patient?

Recommended X-rays for Clinical Evaluation

For initial diagnostic evaluation, a chest X-ray (both anteroposterior and lateral views) is recommended as the first imaging study in most clinical scenarios, followed by appropriate advanced imaging based on specific clinical suspicion.

Initial Imaging Approach

• Chest X-ray (anteroposterior and lateral views) should be the first diagnostic study for patients with respiratory symptoms, suspected thoracic pathology, or as part of initial trauma evaluation 1
• For patients with suspected diaphragmatic hernia, chest X-ray has a sensitivity of 2-60% for left-sided hernia and 17-33% for right-sided hernia, but remains useful as an initial screening tool due to its availability, low cost, and low radiation exposure 1
• In patients with thoracic back pain without myelopathy, radiculopathy, or red flags, imaging is typically not indicated initially 1

Advanced Imaging Based on Clinical Suspicion

Suspected Thoracic Aortic Disease

• For patients with suspected thoracic aortic disease, CT scan with contrast enhancement of the chest and abdomen is strongly recommended after initial chest X-ray 1
• A negative chest X-ray should not delay definitive aortic imaging in patients determined to be high risk for aortic dissection by initial screening 1, 2
• Selection of a specific imaging modality (CT, MRI, or transesophageal echocardiogram) should be based on patient variables and institutional capabilities 1

Suspected Diaphragmatic Hernia

• In stable trauma patients with suspected diaphragmatic hernia, CT scan with contrast enhancement of the chest and abdomen is recommended after initial chest X-ray 1
• In stable trauma patients with lower chest penetrating wounds and suspected diaphragmatic hernia, diagnostic laparoscopy is recommended 1
• In pregnant patients with suspected non-traumatic diaphragmatic hernia, ultrasonography is suggested as the first diagnostic study, followed by MRI 1

Suspected Thoracic Back Pain Pathology

• For thoracic back pain with myelopathy or radiculopathy, MRI of the thoracic spine without IV contrast is usually appropriate for initial imaging 1
• For thoracic back pain with low-velocity trauma, osteoporosis, advanced age, or chronic steroid use, thoracic spine radiography or MRI/CT of the thoracic spine without IV contrast is usually appropriate 1
• For thoracic back pain with suspicion of cancer, MRI of the thoracic spine without and with IV contrast or without IV contrast is usually appropriate 1

Suspected Chronic Dyspnea

• For patients with chronic dyspnea of unclear etiology, chest radiography is usually appropriate as the initial imaging study 1
• For patients with chronic dyspnea and suspected interstitial lung disease, CT without IV contrast is usually appropriate after initial chest X-ray 1
• For patients with chronic dyspnea and suspected diaphragm dysfunction, chest radiography followed by fluoroscopy is usually appropriate 1

Important Considerations and Pitfalls

• Chest X-ray has significant limitations as a screening tool for thoracic aortic disease, with a sensitivity of only 64% for widened mediastinum and 71% for abnormal aortic contour 2
• A completely normal chest X-ray does not exclude significant pathology, particularly in patients with high clinical suspicion for thoracic aortic disease 1, 2
• Chest radiography in the investigation of patients with suspected lung cancer may be harmful due to false reassurance in the case of a normal X-ray, leading to significant delays in diagnosis 3
• For soft tissue masses of the foot, plain radiographs should be the first step to identify bone involvement, calcifications, or radio-opaque foreign bodies, followed by ultrasound as the primary triage tool 4
• Perceptual errors are the predominant source of missed findings on chest X-rays, highlighting the importance of careful interpretation and consideration of advanced imaging when clinical suspicion remains high 5

Special Patient Populations

• In elderly patients, a lower threshold for thorough examination and advanced imaging should be considered, as they are less likely to report symptoms compared to younger patients 6
• In children, radiological findings of COVID-19 on chest X-rays are often nonspecific with minimal interobserver agreement, suggesting chest radiography may not be useful for determining disease severity 7
• For post-pneumonia follow-up in patients over 50 years old, the yield from a 6-12 week chest X-ray for detecting lung malignancy is low (approximately 2%), suggesting the need for more targeted screening approaches 8