What are the next steps for a patient with persistent pain 5-6 weeks after an injury, with a negative chest x-ray (chest radiograph) for fractures?

Management of Persistent Chest Pain 5-6 Weeks Post-Injury with Negative Initial Radiographs

For a patient with persistent chest pain 5-6 weeks after injury and an initially negative chest X-ray, obtain advanced imaging with either MRI without IV contrast or CT without IV contrast to evaluate for occult rib fractures or stress fractures that were not visible on initial radiographs. 1

Rationale for Advanced Imaging at This Time Point

• Initial chest radiographs miss a significant proportion of rib fractures, detecting only 50% of rib fractures compared to CT, and up to 80% of other thoracic injuries may be radiographically occult 1
• At 5-6 weeks post-injury, stress fractures and occult fractures should now be visible on advanced imaging due to bone remodeling and callus formation that occurs during the healing process 1
• Follow-up radiographs at 10-14 days increase sensitivity to 30-70% compared to initial films, but at 5-6 weeks, cross-sectional imaging is more definitive than repeat plain films 1

Recommended Imaging Algorithm

First-Line Advanced Imaging Options

MRI without IV contrast is the preferred modality because:

• It has excellent sensitivity for detecting occult fractures through bone marrow edema patterns 1
• It can identify stress fractures, bone contusions, and soft tissue injuries that may be causing persistent pain 1
• It provides both diagnostic and prognostic information about bone healing 1
• No ionizing radiation exposure 1

CT without IV contrast is an acceptable alternative when:

• MRI is unavailable, contraindicated, or the patient cannot tolerate it 1
• Superior for visualizing cortical bone detail and subtle fracture lines 1
• Faster acquisition time than MRI 1
• Particularly useful for rib fractures where cortical detail is important 1

IV Contrast Is Not Indicated

• Neither MRI nor CT requires IV contrast for fracture evaluation, as contrast does not provide additional diagnostic information for bone injury assessment 1

What to Look For on Advanced Imaging

The radiologist should specifically evaluate for:

• Occult rib fractures that were not visible on initial radiographs, particularly anterior rib fractures which are commonly missed 1
• Stress fractures showing bone marrow edema on MRI or sclerotic lines on CT 1
• Sternal fractures which can cause persistent pain and may be associated with cardiac contusion 1
• Costochondral junction injuries that are radiographically occult but visible on MRI 1
• Underlying complications such as delayed healing, nonunion, or secondary soft tissue injury 1

Common Pitfalls to Avoid

• Do not simply repeat chest radiographs at this time point - while follow-up radiographs at 10-14 days have increased sensitivity, at 5-6 weeks cross-sectional imaging is more definitive 1
• Do not assume pain is musculoskeletal without imaging confirmation - persistent pain at 5-6 weeks warrants investigation for occult fracture or complications 1
• Do not order bone scintigraphy as first-line advanced imaging - while sensitive, it is nonspecific and often requires supplemental imaging with CT or MRI anyway, making cross-sectional imaging the preferred initial approach 1
• Recognize that normal initial radiographs do not exclude fracture - radiographs have only 15-35% sensitivity for stress fractures and miss 50% of rib fractures 1

Clinical Management Considerations

• Most isolated rib fractures have low morbidity and are managed conservatively with pain control and pulmonary hygiene 1
• If advanced imaging confirms a fracture, treatment remains primarily conservative unless complications are identified 1
• If imaging is negative, consider alternative diagnoses such as costochondritis, intercostal muscle strain, or referred pain from thoracic spine pathology 1
• Ensure adequate pain control to prevent complications such as pneumonia from splinting and inadequate respiratory effort 1