Background/Purpose: Dual-energy computed tomography (DECT) allows sensitive and quantative detection of monosodium urate (MSU) crystals in patients with gout. Although its usefulness in diagnosing gout is well defined, its role in monitoring changes of MSU depositions after urate lowering therpy (ULT) is unclear. The aim of our study was to investigate the difference in MSU deposition amount and pattern detected by DECT in well and poorly controlled gout patients.

Methods: DECT scans of feet and ankles were performed in 109 gout patients. Sixteen joints of ankles and feet, and achilles tendon insertion sites were evaluated for the presence of MSU deposition. The total volume of MSU deposition was quantified using an automated software program of DECT. Clinical, laboratory, and radiologic features were obtained at the time of DECT evaluation. Patients who maintained serum uric acid (sUA) level < 6.0mg/dL for more than 6 months prior to DECT evaluation were considered ‘well-controlled’ and otherwise, ‘poorly-controlled’.

Results: Twenty-five (22.9%) well-controlled patients were compared with 84 (77.1%) poorly-controlled. Well-controlled group showed mean sUA of 4.97±0.84mg/dL while poorly-controlled group showed mean sUA of 8.01±1.78mg/dL. Well-controlled group had significantly lower mean volume of MSU deposition compared with the poorly-controlled group (0.12cm³ vs 0.78cm³, p=0.001), and had lower number of MSU deposition (2 vs 4, p=0.002). Although volume and number of MSU depositions were significantly decreased, MSU depositions were still detected in the well-controlled group. In well-controlled group, MSU depositions were less frequently detected in MTP and ankle joints compared with the poorly-controlled group, whearas frequency of MSU deposition was not significantly different in the Chopart joint and Achilles tendon sites.

Conclusion: Well-controlled gout patients showed significantly reduced urate burden. However, since MSU deposition does not completely resolve even in well-controlled pateints, continuous ULT is recommended for optimal management of the gout patients.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/comparision-of-urate-burden-in-well-and-poorly-controlled-gout-patients-a-dual-energy-ct-study/