Quantification of sarcopenia in patients with rheumatoid arthritis by measuring the cross-sectional area of the thigh muscles with magnetic resonance imaging.

PURPOSE: To determine the utility of cross-sectional area (CSA) measurements on magnetic resonance imaging (MRI), at the level of the thigh muscles, to estimate muscle mass in discriminating rheumatoid arthritis (RA) patients with sarcopenia from those without. MATERIALS AND METHODS: Consecutive female RA patients were enrolled for this cross-sectional study. Patients were assessed for disease activity, radiological damage, handgrip strength, physical performance and for the presence of sarcopenia, identified in accordance with the EWGSOP2 criteria. A 1.5 T MRI machine was used to scan the thigh muscles. A dimensional region growth algorithm (Horos™) was used to segment the muscles CSAs (in cm2) on MR images located 25 cm above the knee joint (MRI-CSA-25). The MRI-CSA-25 was obtained by summing the CSAs of the individual muscles. MRI-CSA-25 was correlated (Pearson's r) with the other variables, and its optimal cut-off point (Youden index) for sarcopenia diagnosis was identified in relation to the EWGSOP2 criteria. RESULTS: 32 RA female patients were studied, 34.4% diagnosed as sarcopenic. The mean MRI-CSA-25 was 151.00 cm2 for patient with sarcopenia, 275.57 cm2 for patient without sarcopenia (p < 0.001). MRI-CSA-25 correlated significantly with measures of physical performance, and disease activity, but not with radiological damage or age. The MRI-CSA-25 optimal cut-off point in discriminating sarcopenic patients was identified at 182.00 cm2 (AUC-ROC = 0.894). CONCLUSION: MRI-CSA-25 can differentiate sarcopenic versus non-sarcopenic RA patients, representing an imaging biomarker of this condition.

Imaging of Sacroiliac Pain: The Current State-of-the-Art.

Pain in the sacroiliac (SI) region is a common clinical manifestation, often caused by diseases involving the SI joints. This is typically due to inflammation or degenerative changes, while infections or cancer are less frequent causes. The SI joint is challenging to image accurately because of its distinct anatomical characteristics. For an accurate diagnosis, conventional radiography often needs to be supplemented with more precise methods such as magnetic resonance imaging (MRI) or computed tomography (CT). Sacroiliitis, a common presenting feature of axial spondyloarthritis (axial SpA), manifests as bone marrow edema, erosions, sclerosis, and joint space narrowing. Septic sacroiliitis and repetitive stress injuries in sports can also cause changes resembling inflammatory sacroiliitis. Other conditions, such as osteitis condensans ilii (OCI), can mimic the radiologic characteristics of sacroiliitis. Inflammatory lesions are diagnosed by concurrent erosions, hyperostosis, and ankylosis. Ligament ossifications or mechanical stress can also result in arthritic disorders. Determining the exact diagnosis can be aided by the distribution of the lesions. Inflammatory lesions can affect any part of the articulation, including the inferior and posterior portions. Mechanical lesions, such as those seen in OCI, often occur in the anterior middle region of the joint. In cases of idiopathic skeletal hyperostosis, ligament ossification is found at the joint borders. This pictorial essay describes common SI joint problems, illustrated with multimodal imaging data. We, also, discuss strategies for selecting the best imaging modalities, along with imaging pitfalls, key points, and approaches for treating patients with suspected inflammatory back pain.

Magnetic Resonance Imaging (MRI)-Based Semi-Quantitative Methods for Rheumatoid Arthritis: From Scoring to Measurement.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the small joints of the hands and feet, characterized by pain, inflammation, and joint damage. In this context, magnetic resonance imaging (MRI) is useful to identify and monitor joint/tendon inflammation and the evolution of joint damage, playing a key role in treatment response evaluation, in addition to clinical measurements. Various methods to quantify joint inflammation and damage with MRI in RA have been developed, such as RA-MRI Score (RAMRIS), Early RA-MRI Score (ERAMRS), and Simplified RA-MRI Score (SAMIS). RAMRIS, introduced in 2002, offers an objective means to assess inflammation and damage via MRI in RA trials, encompassing findings such as synovitis, bone erosion, and edema/osteitis. Recently, an updated RAMRIS version was developed, which also includes the evaluation of joint space narrowing and tenosynovitis. The RAMRIS-5, which is a condensed RAMSIS version focusing on five hand joints only, has been proven to be a valuable resource for the semi-quantitative evaluation of RA joint damage, both in early and established disease. This narrative literature review will provide an overview of the MRI scoring systems that have been developed for the assessment of joint inflammation and structural damage in RA patients.