Dual-energy CT for detection of knee fractures as alternative to MRI

Dual-energy CT (DECT) has emerged as a valuable imaging modality in musculoskeletal radiology, offering unique capabilities through virtual non-calcium reconstructions and spectral analysis. This narrative review examines the current evidence and clinical applications of DECT as an alternative to MRI in acute knee trauma evaluation. We discussed the technical principles of DECT, including virtual non-calcium imaging for bone marrow edema detection, metal artifact reduction techniques, and soft tissue assessment capabilities. The review covers six key clinical applications: complex fractures with articular involvement, subtle impacted fractures, stress fractures and healing assessment, imaging around metallic implants, osteochondritis dissecans evaluation, fracture assessment in specific knee locations. Current evidence indicates that DECT can detect bone marrow edema with sensitivity and specificity comparable to MRI, while providing distinct advantages in availability, acquisition speed, and compatibility with metallic implants. The advent of photon-counting CT technology is expected to further enhance both spatial resolution and spectral differentiation. Although MRI remains the gold standard for comprehensive assessment of knee trauma, DECT offers a practical alternative in selected clinical scenarios-particularly in emergency settings and in patients with contraindications to MRI. Future studies should aim to standardize acquisition protocols and establish evidence-based guidelines to support its optimal clinical application.