Foot and Ankle Inflammatory Arthritis

Advanced Imaging of Gout and Other Inflammatory Diseases Around the Knee

“…Gout is the most common form of inflammatory arthropathy resulting from MSU crystal deposition, and its prevalence is increasing in Western societies. 13 26 27 The knee, following the metatarsophalangeal joints, is the second most common location affected by gout. 26 If left untreated, the persistent deposition of MSU crystals in the joints and surrounding soft tissues can lead to progressive joint destruction.…”

“…13 26 27 The knee, following the metatarsophalangeal joints, is the second most common location affected by gout. 26 If left untreated, the persistent deposition of MSU crystals in the joints and surrounding soft tissues can lead to progressive joint destruction. 13…”

“…Diagnosing gout hinges on identifying negatively birefringent MSU crystals in joint fluid or tophi through polarized microscopy. 13 26 However, this method is infrequently used in clinical practice due to its invasiveness and other limitations. 13 Imaging modalities that can facilitate the diagnosis of gout and are included in the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria: plain radiography (presence of typical bone erosions), US (presence of a “double-contour” sign), and DECT (color-coded MSU crystals) 27 ( Fig.…”

“…Features of early and chronic gout on US are well described in the literature. 26 In early gout, joint effusions with or without hyperechoic MSU crystal foci may be seen that measure < 1 mm (“starry sky” sign). Larger MSU aggregates, referred to as micro-tophi, may result in a “snowstorm” appearance.…”

“…In chronic gout, the tophi appear as well circumscribed, hyperechoic, or hypoechoic nodules that initially are uniform. 26 28 With chronicity, they become nonhomogeneous (“wet clumps of sugar” sign), with characteristic tiny internal hyperechoic echoes or aggregates. Juxta-articular erosions may also be seen.…”