From the Guidelines
Posterior rib pain may be visible on a chest X-ray (CXR) if it's caused by a fracture, but CXR has significant limitations for this purpose, missing approximately 50% of rib fractures. While CXR can detect obvious rib fractures, it is not sensitive enough to detect subtle fractures, stress fractures, or bone bruising causing posterior rib pain due to overlapping structures and the orientation of ribs relative to the X-ray beam 1.
For better visualization of posterior rib pain causes, a dedicated rib series X-ray (which includes oblique views) or more advanced imaging like CT scan would be more appropriate. CT scans are much more sensitive, detecting up to 95% of rib fractures and can also identify soft tissue injuries, pleural effusions, or other complications 1.
If posterior rib pain persists and initial X-rays are negative, further imaging should be considered, especially if the pain is severe, worsening, or associated with trauma. It's worth noting that many causes of posterior rib pain, such as costochondritis, muscle strain, or intercostal neuralgia, won't show any abnormalities on imaging studies at all 1.
Some key points to consider when evaluating posterior rib pain include:
- The use of radiographic rib series may be helpful to assess for rib fracture or other rib lesion, especially for focal chest wall pain detected at physical examination 1
- CT chest without IV contrast or Tc-99m bone scan whole body may be complementary to chest radiography for suspected pathologic rib fracture 1
- The American College of Radiology Appropriateness Criteria recommend standard chest radiographs as usually sufficient for the diagnosis of rib fractures, with further imaging generally not appropriate unless there are complications or underlying organ injuries 1.
Given the limitations of CXR and the potential for missed diagnoses, a dedicated rib series X-ray or CT scan should be considered for patients with persistent or severe posterior rib pain, especially if initial X-rays are negative. This approach can help identify underlying causes of pain and guide appropriate management, ultimately improving patient outcomes in terms of morbidity, mortality, and quality of life.
From the Research
Posterior Rib Pain Visibility on CXR
- Posterior rib pain can be challenging to diagnose using a chest X-ray (CXR) alone, as CXR may not always detect rib fractures, especially if they are non-displaced or located in areas that are difficult to visualize 2.
- A study found that screening CXRs miss rib fractures more than 50% of the time, and radiology reports are often not sufficiently descriptive or are incomplete with respect to the number and location of fractures 2.
- However, the presence of any rib fracture or pulmonary contusion visible on the initial plain CXR significantly increases the incidence of pulmonary morbidity or mortality 2.
- CT scans provide better anatomic definition of chest injuries than plain CXR and can help identify rib fractures, including those located posteriorly 2.
Comparison with Other Imaging Modalities
- Other imaging modalities, such as CT and MRI, may be more sensitive than CXR in detecting rib fractures and other thoracic injuries 2, 3, 4.
- However, the choice of imaging modality depends on the specific clinical scenario and the availability of resources 5, 6.
- In general, CXR is often used as an initial screening tool, while CT and MRI are used for more detailed evaluation and diagnosis 2, 3, 4.