Referral Patterns for Dual-Energy Computed Tomography in Diagnosis and Management of Gout: Ten-Year Experience at a Canadian Institution

Abstract

Purpose To analyze the utilization, indications, and outcomes of dual-energy computed tomography (DECT) gout imaging in clinical practice. Methods This retrospective study was ethics approved. Radiology reports of DECT gout scans between 2007 and 2016 were analyzed for trends of utilization, referral pattern, indication, and diagnosis. Results DECT gout referrals increased substantially (2007: 37; 2008: 72; 2016: 385; total: 1877). The largest number of referrals were from rheumatology (1160), emergency medicine (283), and family medicine (177). Most referrals (92%) were requested to aid an initial diagnosis of gout. Other reasons included estimating the disease burden (6%) or monitoring disease progression and effectiveness of treatment (2%). Rheumatology accounted for most referrals for the latter two reasons (81% and 97%). Imaging findings of urate presence were similar in referrals from rheumatology (62%), family medicine (62%), and other medical specialties (62%). The urate positive rates were slightly lower in referrals from emergency medicine (47%) and surgical specialties (41%). The most common differential diagnoses by referring specialties were calcium pyrophosphate dihydrate crystal deposition disease (CPPD) and other inflammatory or erosive arthritides (rheumatology, family medicine), CPPD and infections (other medical specialties), infections and fractures (emergency medicine), neoplasm and infections (surgical specialties). Conclusions The increasing utilization of DECT for gout imaging validates its clinical value. Varying clinical presentation could explain differences of urate positive rates among specialties. Our results support a multispecialty collaborative approach to the diagnosis and management of gout, with direct access to DECT gout imaging provided to various physician specialties.