Added value of high-resolution ultrasound and MRI in the evaluation of rheumatologic diseases.

Rheumatologic diseases are a widespread group of disorders affecting the joints, bones, and connective tissue, and leading to significant disability. Imaging is an indispensable component in diagnosing, assessing, monitoring, and managing these disorders, providing information about the structural and functional alterations occurring within the affected joints and tissues. This review article aims to compare the utility, specific clinical applications, advantages, and limitations of high-resolution ultrasound and magnetic resonance imaging in the context of rheumatologic diseases. It also provides insights into the imaging features of various types of inflammatory arthritis with clinical relevance and a focus on high-resolution ultrasound and magnetic resonance imaging. By understanding the comparative aspects of high-resolution ultrasound and magnetic resonance imaging, it is easier for the treating physicians to make informed decisions when selecting the optimal imaging modality for specific diagnostic purposes, effective treatment planning, and improve patient outcomes. The patterns of soft tissue and joint involvement; bony erosion and synovitis help in differentiating between various type of arthritis. Involvement of various small joints of the hands also gives an insight into the type of arthritis. We also briefly discuss the potential applications of emerging techniques, such as ultrasound elastography, contrast-enhanced ultrasound, and dual-energy CT, in the field of rheumatology.