What does an abnormal X-ray (X-ray) result mean?

Understanding Abnormal X-ray Results

Abnormal X-ray findings indicate structural or functional abnormalities that require further evaluation, with the specific interpretation depending on the anatomical area imaged and the nature of the abnormality detected. 1

Common Abnormal X-ray Findings and Their Meanings

Chest X-ray Abnormalities

• Routine chest X-rays show abnormal findings in 2.5-60.1% of cases, leading to changes in clinical management in 0-51% of those cases 1
• For clinically indicated chest X-rays, abnormal findings are reported in 7.7-65.4% of cases and lead to changes in management in 0.5-74.3% of those abnormal cases 1
• Abnormal findings may include:
  • Widened mediastinum, which could suggest aortic pathology 1
  • Mass effect or distortion of para-aortic structures 1
  • Aortic tortuosity or widening, potentially indicating aneurysm 1
  • Pneumothorax, hemothorax, or lung contusions that may not be readily apparent 1
  • Rib fractures or other osseous abnormalities 1

Musculoskeletal X-ray Abnormalities

• In patients with diabetes and suspected active Charcot neuro-osteoarthropathy, X-rays may show: 1
  • Diffuse soft tissue swelling
  • Joint effusion
  • Reduced bone density
  • Cortical erosions
  • Fractures or fracture fragments
  • Subluxation or dislocation of joints

Cardiovascular X-ray Abnormalities

• Chest X-rays may reveal: 1
  • Prominent curvilinear shadow along the mid-right sternal border (dilated ascending aorta)
  • "3 sign" adjacent to the area beneath the transverse arch
  • Notching on the underside of ribs from collateral vessels
  • Left ventricular hypertrophy or asymmetry of the aortic knob 1

Limitations of X-ray Interpretation

• X-rays have lower sensitivity compared to advanced imaging modalities like CT and MRI 1
• Up to 40% of patients with a "normal" chest X-ray may have injuries detectable on CT 1
• Approximately 29% of patients with an "abnormal" chest X-ray may have no injury on CT 1
• X-rays miss approximately: 1
  • Half of all pneumothoraces, pulmonary contusions, and rib fractures
  • Three-quarters of all hemothoraces
  • Most cases of aortic injury

Next Steps After Abnormal X-ray Findings

Further Imaging

• When X-rays appear normal but clinical suspicion remains high, advanced imaging is recommended: 1
  • MRI is preferred for suspected bone/joint abnormalities
  • CT scan when MRI is unavailable or contraindicated
  • Nuclear imaging scans (scintigraphy) or SPECT-CT in specific cases

Clinical Correlation

• Abnormal X-ray findings should be correlated with clinical presentation 1
• The presence of an abnormal finding on neurological examination significantly increases the likelihood of an abnormality on imaging 1
• Specific symptoms like rapidly increasing frequency of symptoms, dizziness, or numbness may warrant further investigation 1

Important Considerations

• Errors and discrepancies in radiology interpretation are relatively common (3-5% of studies) 2
• Not all discrepancies between radiology reports and subsequent outcomes represent errors 2
• X-ray interpretation should be performed systematically to minimize errors 1
• Weight-bearing radiographs are preferred for musculoskeletal assessment when feasible, as they may detect dynamic abnormalities not apparent on non-weight-bearing images 1

When to Seek Immediate Medical Attention

• Abnormal findings suggesting immediate life-threatening conditions require urgent evaluation: 1
  • Tension pneumothorax
  • Significant mediastinal injury
  • Unstable fractures or dislocations
  • Evidence of aortic or major vascular injury

Remember that an abnormal X-ray is often just the first step in diagnosis, and further evaluation is typically needed to determine the clinical significance and appropriate management of the findings 1.