Prevalence of Monosodium Urate (MSU) Deposits in Cadavers Detected by Dual-Energy Computed Tomography (DECT)

Abstract

Background: Dual-energy computed tomography (DECT) allows direct visualization of monosodium urate (MSU) deposits in joints and soft tissues. Purpose: To describe the distribution of MSU deposits in cadavers using DECT in the head, body trunk, and feet. Materials and Methods: A total of 49 cadavers (41 embalmed and 8 fresh cadavers; 20 male, 29 female; mean age, 79.5 years; SD ± 11.3; range 52–95) of unknown clinical history underwent DECT to assess MSU deposits in the head, body trunk, and feet. Lens, thoracic aorta, and foot tendon dissections of fresh cadavers were used to verify MSU deposits by polarizing light microscopy. Results: 33/41 embalmed cadavers (80.5%) showed MSU deposits within the thoracic aorta. 11/41 cadavers (26.8%) showed MSU deposits within the metatarsophalangeal (MTP) joints and 46.3% of cadavers demonstrated MSU deposits within foot tendons, larger than and equal to 5 mm. No MSU deposits were detected in the cranium/intracerebral vessels, or the coronary arteries. Microscopy used as a gold standard could verify the presence of MSU deposits within the lens, thoracic aorta, or foot tendons in eight fresh cadavers. Conclusions: Microscopy confirmed the presence of MSU deposits in fresh cadavers within the lens, thoracic aorta, and foot tendons, whereas no MSU deposits could be detected in cranium/intracerebral vessels or coronary arteries. DECT may offer great potential as a screening tool to detect MSU deposits and measure the total uric acid burden in the body. The clinical impact of this cadaver study in terms of assessment of MSU burden should be further proven.

Impact of Dual-Energy Computed Tomography (DECT) Postprocessing Protocols on Detection of Monosodium Urate (MSU) Deposits in Foot Tendons of Cadavers

“…Tendon involvement in patients with gout has been evaluated by US and DECT [30][31][32] and it has been shown that tendons are a frequent location of extraarticular MSU deposition in the lower limbs, especially in longstanding gout. DECT demonstrated high sensitivity, specificity, and reproducibility in the detection of MSU deposits in tendons in previous studies [26,31,33,34]. Yuan et al [3] reported tendons as the most frequent anatomical location site of MSU deposits in a DECT study of 184 joints, regardless of whether the intraarticular DECT results were positive or negative.…”

“…Several typical artifacts have been well described in the literature, e.g., finger nails, tendons and vessels [ 25 ]. Only a few studies correlated DECT findings with polarizing light microscopy [ 26 ]. Given the lack of verification by microscopy of extraarticular MSU deposits in published studies, it remains questionable whether these findings represent true urate or artifact.…”

Frequently Encountered Artifacts in the Application of Dual‐Energy Computed Tomography to Cardiovascular Imaging for Urate Crystals in Gout: A Matched‐Control Study

“…However, another cadaveric DECT study published by the same group of investigators found no evidence of coronary MSU deposition, although they were identified in the lens, thoracic aorta, and foot tendons. 9 In another study of 96 patients with gout and hyperuricemia and controls, 102 plaques with DECT findings suggestive of MSU deposition using default settings were reported, with 74.2% of them having evidence of calcification adjacent to the DECT MSU findings. 18 Based on the fact that beam hardening was a highly prevalent source of artifactual DECT findings in our study, further investigation of these plaques with advanced DECT measurements may have shed more clarity on whether these areas of green colorization were, in fact, suggestive of MSU deposition or artifacts.…”

“…Several published reports have shown evidence of microscopic MSU crystals in postmortem and surgical specimens. [6][7][8][9] Consequently, there has been surging interest in the novel application of dual-energy computed tomography (DECT) technology to noninvasively identify macroscopic cardiovascular MSU crystals. DECT, which has revolutionized musculoskeletal imaging in patients with gout, is a unique imaging modality that allows for the identification and quantification of MSU crystal deposits based on their chemical composition.…”

“…One emerging hypothesis to explain the strong association between gout and CVD is the direct deposition of MSU crystals in the vicinity of atherosclerotic plaque, contributing to plaque progression and instability. Several published reports have shown evidence of microscopic MSU crystals in postmortem and surgical specimens 6–9 . Consequently, there has been surging interest in the novel application of dual‐energy computed tomography (DECT) technology to noninvasively identify macroscopic cardiovascular MSU crystals.…”