The application of dual-energy computed tomography in the diagnosis of musculoskeletal disorders: a review of current concepts and applications.

With the assistance of innovations in scanner engineering and software design, dual-energy computed tomography (DECT) is an advanced imaging method that has been developed over the last decade. With its unique ability to differentiate materials by their atomic number, DECT has opened new perspectives in imaging. The principal advantages of DECT over conventional CT in the musculoskeletal setting relate to the additional information provided regarding tissue composition, artifact reduction and image optimization. In musculoskeletal imaging, uric acid material decomposition images can help identify articular deposition of uric acid crystals (in addition to the detection of uric acid renal stones). Material separation can also help detect bone marrow edema on CT in the case of trauma, algoneurodystrophy, inflammation (osteitis) or malignant bone marrow infiltrates, such as metastases. DECT also offers means to reduce the radiation exposure of patients by replacing multiphase exams with more specific single acquisitions. The first part of this article reviews the basic principles and technical aspects of DECT. The second part focuses on applications of DECT to musculoskeletal imaging including that of gout and other crystal-induced arthropathies, virtual non-calcium images for the study of bone marrow lesions, the study of collagenous structures, as well as the detection of hemosiderin and metal particles.