Would a computed tomography (CT) scan of the abdomen and pelvis show a right hip fracture?

CT of Abdomen and Pelvis Can Detect Hip Fractures but May Miss Occult Fractures

A CT scan of the abdomen and pelvis can show a right hip fracture, but it has limited sensitivity compared to MRI and may miss occult or non-displaced fractures. 1, 2

Diagnostic Performance of CT for Hip Fractures

• CT has advantages over MRI in terms of speed and use in patients with significant confusion 1
• Sensitivity of CT for detecting hip fractures ranges from 69-94% 1, 2, 3
• Specificity of CT for hip fractures is high, approaching 100% 3

Limitations of CT for Hip Fractures

• Multiple studies demonstrate potential limitations in CT sensitivity:

  • Haubro et al. found CT sensitivity of 87% compared to 100% for MRI, with CT missing 6 of 15 fractures 1
  • Cabarrus et al. found CT sensitivity of only 69% compared to 99% for MRI 1
  • A 2019 systematic review and meta-analysis found CT sensitivity of 94% for occult proximal femoral fractures 3

• CT is particularly limited in detecting:

  • Non-displaced fractures
  • Bone marrow edema
  • Soft tissue abnormalities (13% sensitivity for edema) 1

Clinical Implications

• If a hip fracture is suspected and CT abdomen/pelvis is negative, further imaging with MRI should be considered 1, 2, 4
• Missed hip fractures can lead to increased complications, hospital stays, and mortality rates 2
• For patients with ongoing clinical concern about hip fracture despite normal CT findings, MRI should be performed 3

Practical Considerations

• If CT examination of the abdomen and pelvis is performed for other reasons (e.g., suspected intra-abdominal trauma), bone algorithm reconstruction of the pelvis and hips can be performed to better evaluate for fractures 1
• Standard CT protocols for abdomen/pelvis may not be optimized for bone detail, potentially reducing sensitivity for subtle fractures
• Dual-energy CT shows promise for detecting bone marrow edema but still does not approach the diagnostic accuracy of MRI 1

Imaging Algorithm for Suspected Hip Fracture

1. Plain radiographs (X-rays) of the pelvis and hip should always be the first test ordered 2
2. If radiographs are nondiagnostic and hip fracture is still suspected:
   • MRI without contrast is the preferred next imaging study (99% sensitivity) 1, 2
   • CT without contrast if MRI is contraindicated or unavailable (69-94% sensitivity) 1, 2, 3
   • Consider MRI even after negative CT if clinical suspicion remains high 4

Remember that delays in diagnosis can significantly impact morbidity and mortality, especially in elderly patients, making accurate and prompt imaging crucial 2.