Does evaluation of the ligamentous compartment enhance diagnostic utility of sacroiliac joint MRI in XXXX ?

@entity1 @entity1596 @entity615 @entity1691 @entity4648 @entity2720 @entity236
INTRODUCTION: Inflammation of the @entity2720 ( @entity2720 ) is a fundamental clinical feature of @entity1691 (SpA). The anatomy of the irregularly shaped @entity2720 is complex with an antero-inferior cartilaginous compartment containing central hyaline and peripheral fibrocartilage, and a dorso-superior ligamentous compartment. Several scoring modules to systematically assess @entity2720 magnetic resonance imaging (MRI) in SpA have been developed. Nearly all of them are based on the cartilaginous joint compartment alone. However, there are only limited data about the frequency of inflammatory lesions in the ligamentous compartment and their potential diagnostic utility in axial SpA. We therefore aimed to evaluate the ligamentous compartment on sacroiliac joint MRI for lesion distribution and potential incremental value towards diagnosis of SpA over and above the traditional assessment of the cartilaginous compartment alone. METHODS: Two independent cohorts of 69 and 88 consecutive @entity615 @entity1  <=50 years were referred for suspected SpA (cohort A) or acute anterior @entity1596 plus @entity615 (cohort B). @entity1 were classified according to rheumatologist expert opinion based on clinical, radiographic and laboratory examination as having nonradiographic axial SpA (nr-axSpA; n = 51), @entity1691 (n = 34), or @entity615 ( @entity615 ; n = 72). Five blinded readers assessed @entity2720 MRI globally for presence/absence of SpA. @entity236 ( @entity236 ) and fat @entity4648 were recorded in the cartilaginous and ligamentous compartment. The incremental value of evaluating the ligamentous additionally to the cartilaginous compartment alone for diagnosis of SpA was graded qualitatively. We determined the lesion distribution between the two compartments, and the impact of the ligamentous compartment evaluation on diagnostic utility. RESULTS: MRI bone @entity236 solely in the ligamentous compartment in the absence of lesions in the cartilaginous compartment were reported in just 0-2.0/0-4.0 % ( @entity236 /fat @entity4648 ) of all subjects. Additional assessment of the ligamentous compartment was regarded as essential for diagnosis in 0 and 0.6 %, and as contributory in 28.0 and 7.7 % of nr-axSpA @entity1 in cohorts A and B, respectively. Concomitant @entity236 in both compartments was evident in 11.6-42.0 % of nr-axSpA and 2.1-2.4 % of @entity615 @entity1 . CONCLUSION: Assessing the ligamentous compartment on @entity2720 MRI provided no incremental value for diagnosis of axial SpA. However, concomitant @entity236 in both compartments may help discriminate nr-axSpA from @entity615 .
