Dual-energy computed tomography diagnostics for gout

Non-invasive imaging modalities are used for the morphological and functional evaluation and diagnosis of gout; however, none of these methods are sufficiently sensitive or specific for the diagnosis of gout. By the use of dual-energy computed tomography (DECT) the direct visualization of sodium urate deposition is now possible. Moreover, it is possible to show the different pathological situations, disease activity and monitoring of tophaceous gout. The positive DECT scan became one of the 2015 ACR/EULAR classification criteria for gout 2 years ago. The literature search from 2009-2017 in PubMed, with the search criteria "Dual Energy CT and Gout" revealed 77 publications on the DECT method. The DECT technique has a high sensitivity (90-100%) and a high specificity (83-89%) for diagnosing gout. The development of a semiquantitative scoring method also enables measurement of the severity of urate deposits at specific sites. The gold standard for the diagnosis of gout is still the detection of monosodium urate monohydrate crystals by polarizing microscopy after a joint punction; however with the DECT it is possible to non-invasively visualize, measure and score urate deposition and is therefore suitable for estimating the severity and prognosis. Although not clinical validated, DECT may sometimes help to detect gout. More studies should be conducted.