Dual-Energy CT: Current Principles, Clinical Applications, And Future Perspectives

Abstract

Dual-energy computed tomography (DECT) has transformed modern computed tomography by enabling the acquisition of imaging data at two different energy spectra, thereby providing additional diagnostic information beyond conventional single-energy CT. By exploiting energy-dependent attenuation differences among tissues and materials, DECT allows improved tissue characterisation, material differentiation, and quantitative analysis. Recent technological developments, including dual-source systems, rapid kVp-switching techniques, dual-layer detector technology, and photon-counting CT, have significantly enhanced the clinical applicability of spectral imaging. Advanced reconstruction methods such as virtual monoenergetic imaging, virtual non-contrast imaging, iodine mapping, and material decomposition have expanded the diagnostic capabilities of DECT. These techniques improve lesion conspicuity, reduce imaging artefacts, optimize contrast enhancement, and provide valuable functional information.  As a result, DECT has found widespread applications in cardiothoracic, abdominal, gastrointestinal, musculoskeletal, neurological, oncological, and emergency imaging. Despite its advantages, challenges such as high equipment costs, variability among imaging platforms, and the need for standardised protocols continue to influence its broader implementation. Ongoing advancements in artificial intelligence, radiomics, quantitative imaging biomarkers, and photon-counting technology are expected to improve diagnostic accuracy and clinical utility further.  This review highlights the fundamental principles, technological developments, clinical applications, advantages, limitations, and prospects of DECT, emphasising its growing role in precision imaging and contemporary radiological practice.