What is the proper procedure for interpreting x-rays (radiographs)?

Systematic Approach to X-Ray Interpretation

A systematic approach to interpreting radiographs is essential to minimize perceptual errors and ensure accurate diagnosis, which directly impacts patient morbidity and mortality. This approach should follow a structured methodology to avoid missing critical findings.

General Principles for X-Ray Interpretation

• Always use a systematic approach to avoid missing important findings, as perceptual errors are the most common interpretive errors in radiology 1
• Ensure proper viewing conditions with appropriate monitors - liquid crystal display monitors are preferable to cathode ray tube monitors, with a two-monitor setup considered most functional 2
• Minimize radiation exposure to patients by following ALARA (As Low As Reasonably Achievable) principles when obtaining images 2
• Always have access to relevant prior imaging studies and clinical information to make accurate comparisons and interpretations 2

Step-by-Step Approach to Chest X-Ray Interpretation

1. Technical Quality Assessment

• Evaluate for proper positioning, penetration, and inspiration 3
• Check patient identification and examination date 2
• Ensure all anatomical structures are included in the field of view 3

2. Systematic Review of Anatomical Structures

Airway and Mediastinum:

• Examine tracheal position and patency 3
• Assess mediastinal contours and width (widened mediastinum may indicate aortic injury or dissection) 3
• Evaluate cardiac size and silhouette (cardiothoracic ratio >0.5 indicates cardiomegaly) 3
• Check for pneumomediastinum 3

Lung Fields:

• Systematically examine for focal opacities or consolidation 3
• Evaluate for interstitial patterns (reticular, nodular, or reticulonodular) 3
• Compare side-to-side for symmetry 3

Pleura:

• Assess for pneumothorax (visible pleural line with absence of lung markings peripherally) 3
• Look for pleural effusion (meniscus sign, blunting of costophrenic angles) 3
• Evaluate for pleural thickening or plaques 3

Bones and Soft Tissues:

• Examine ribs, clavicles, scapulae, and vertebrae for fractures or lesions 3
• Check for soft tissue abnormalities such as subcutaneous emphysema or masses 3
• Evaluate diaphragm contours and position 3

3. Special Considerations

Trauma Patients:

• Pay special attention to widened mediastinum, rib fractures, and pneumothorax or hemothorax 3

Suspected Pulmonary Embolism:

• Look for Westermark sign and Hampton's hump 3
• Note that a normal chest X-ray with acute dyspnea and hypoxemia increases suspicion for PE 3

Common Pitfalls and How to Avoid Them

• Satisfaction of search - after finding one abnormality, continue systematic review to avoid missing additional findings 1
• Chest X-rays have lower sensitivity compared to CT for many conditions, with up to 50% of pneumothoraces, pulmonary contusions, and rib fractures potentially being missed on standard AP radiographs 3
• Senior doctors (consultants and registrars) perform significantly better at X-ray interpretation than junior doctors, suggesting the importance of experience and training 4
• Radiologists achieve significantly higher accuracy in interpreting chest X-rays compared to non-radiologist physicians 4, 5
• When in doubt, consult a radiologist - it is critical that clinicians recognize when radiological consultancy should be sought 6

Radiation Safety Considerations

• Minimize beam-on time during fluoroscopy and acquisition to reduce radiation exposure 2, 7
• Use optimal beam collimation to limit X-ray beam size to the minimum area needed 2, 7
• Position the X-ray source and image receptor optimally - minimize the distance from the patient to the image detector 2, 7
• Use the least degree of image magnification required for accurate interpretation 2, 7
• Record the estimated dose delivered to the patient 2, 8

Educational Considerations

• Structured teaching on X-ray interpretation should be available for newly qualified doctors 4
• E-learning resources can effectively teach systematic chest X-ray interpretation approaches 9
• Medical students should be trained in basics of image interpretation and recognition of when radiological consultation is needed 6

By following this systematic approach to X-ray interpretation, clinicians can minimize errors, improve diagnostic accuracy, and ultimately enhance patient outcomes by ensuring timely and appropriate treatment based on accurate radiographic findings.