Abstract

Entheses are sites of attachment of tendons, ligaments, fascia, or capsule into bone, providing a mechanism for reducing stress at the bony interface. Entheses dissipate biomechanical stress and, in doing so, are thought to be subjected to repeated micro traumas.

Inflammation of the entheses, enthesitis, is a well-known hallmark of spondyloarthritis (SpA), playing a central role in disease pathogenesis. It can also be associated with degenerative, endocrinologic, metabolic and traumatic conditions.

Magnetic resonance imaging (MRI) is a sensitive tool for the detection of early signs of enthesitis in patients with SpA. The MRI features of enthesitis are well described, and include thickened enthesis with altered signal intensity and perientheseal soft tissue edema. Bone marrow edema and erosions at the adjacent bone appear mainly in SpA-associated enthesitis. Contrast material administration improves the reliability, sensitivity and specificity of detecting enthesitis on an MRI.

Whole-body (WB) MRI allows assessment of all peripheral and axial joints and entheses from “head-to-toe” in one examination. The promising role of WBMRI in the evaluation of enthesitis in SpA and other rheumatic diseases was evaluated in several cross sectional and prospective studies. Indeed WB MRI was shown to be sensitive in the detection of inflammatory lesions, including enthesitis, on multiple sites, potentially serving as a one stop shop for the estimate of active disease load.

In the current presentation, the typical imaging properties of enthesitis on conventional and WB-MRI will be presented along with several challenging quiz cases.