Resurgence of CT for Musculoskeletal Applications: Where Are We in 2021?

Presentation Format: Educational poster presentation.

Purpose or Learning Objective: To illustrate the value of computed tomography (CT) for musculoskeletal applications CT compared with other imaging modalities and also illustrate its problem-solving capacities.

Methods or Background: Magnetic resonance imaging (MRI) has become the standard of care in musculoskeletal imaging except in trauma and the emergency setting. Recent technological improvements in CT technology have contributed to a renewed interest of musculoskeletal applications of CT.

Results or Findings

1. Dual-energy CT

   • - Allows precise characterization of urate crystals from other types of crystalline deposition.

   • - Detects bone marrow edema in radiographic occult fractures and osteomyelitis.

   • - Reduces metal artifacts.

2. Cone beam computed tomography (CBCT)

   • - Offers high spatial resolution at low dose.

   • - Plays an emergent role for a more precise diagnosis of fractures, local extent, complexity of fractures, dislocations, and for follow-up.

3. Characterizations of lesions: certain CT characteristics can suggest a specific diagnosis.

   • - The mineralization matrix: osteoid in bone-forming tumors, ground-glass appearance in fibrous dysplasia, and high-density attenuation measurements in enostosis.

   • - Detection of the nidus and central calcification in osteoid osteoma.

4. Fracture evaluation

   • - CT volume-rendered three-dimensional reconstruction allows for improved visualization of complex fractures, preoperative planning, and postoperative follow-up.

5. Staging of cartilage lesions

   • - Although MRI is the initial technique to detect osteochondral lesions, increased spatial resolution of CBCT arthrography permits excellent assessment of the articular cartilage.

6. Hybrid imaging

   • - Imaging techniques such as positron emission tomography/CT (PET/CT) or single-photon emission/computed tomography (SPECT/CT) allow the direct fusion of morphological information and functional information.

7. Biomechanical information

   • - Four-dimensional computed tomography (4DCT) may provide a thorough understanding of the pathophysiology of joint kinematics and instability.

8. CT-guided intervention

   • - CT-guided intervention plays a critical role in interventional procedures such as biopsy, abscess drainage, tumor ablation, catheter placement, and minimally invasive spinal surgery.

   • - Compared with fluoroscopic guidance, the major advantage of CT is the cross-sectional visualization of the anatomy and interventional materials.

Conclusion: Although MRI is regarded as the preferred imaging modality for the assessment of musculoskeletal lesions, recent technological improvements have made CT a valuable tool to evaluate selected musculoskeletal problems and to tackle specific clinical scenarios.