AB0761 Comparison Between Colour Doppler Ultrasound and MRI in Documenting Response to Treatment with Nsaids and in Assessing Disease Activity in Non-Radiographic Spondyloarthropathy
Authors: D. Sinha, A. Nag, S. Mondal, A. Ghosh
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> Axial type of Spondyloarthropathy (SpA) can be subdivided into the (early) non-radiographic type and the radiographic type, which is equivalent to the diagnosis of Ankylosing Spondylitis. The proportion of nonradiographic axial SpA (nr-SpA) patients among those with newly diagnosed axial SpA ranges between 23 to 80%. 1 MRI proven sacroiliitis is the "gold standard" for the diagnosis of nr-SpA. But, we have seen in some previous studies that USG can be a reliable substitute to MRI for detecting sacroiliitis in non-radiographic Spondyloarthropathy (SpA). According to a study done by Ghosh et al, 29 radiographically negative patients fulfilling the definition of IBP (ASAS 2009) &amp; 32 age and sex matched controls were made to undergo MRI and USG of their SI joints. 2 A significant difference in the number of USG documented Flow Signals (FS) of the SI joint (p&lt;0.0001) between MRI proven cases and controls had been observed and a ROC analysis revealed a cut off value of 3 FS for optimum sensitivity and specificity of detecting sacroiliitis (sensitivity 90% &amp; specificity 92.7%). <h3>Objectives</h3> To assess changes in ultrasound features of sacroiliitis after NSAID use in patients with non-radiographic SpA, to compare the changes with that of MRI after treatment and to see whether Colour Doppler Ultrasound can help in monitoring disease activity. <h3>Methods</h3> 35 patients diagnosed with non radiographic spondyloarthropathy based on inflammatory low back pain and MRI proven sacroiliitis, were made to undergo a baseline USG of sacroiliac (SI) joints. They were then kept on NSAIDs for a duration of 3 months. After 3 months, USG and MRI of sacroiliac joints were repeated and the both compared. USG findings at baseline and at follow up were also correlated with BASDAI. <h3>Results</h3> A Wilcoxons signed rank test was done to compare the number of flow signals on USG of SI joint at baseline and after 3 months of treatment and p value was found to be significant (p&lt;0.05), which means that vascularity of SI joints significantly decreases with NSAID. Number of flow signals in SI joint also correlated well with BASDAI at baseline (Spearman9s rho correlation coefficient =0.632) and at follow up (Spearman9s rho correlation coefficient =0.701). However, MRI at baseline and follow up were same and could not assess change with NSAID nor could it predict disease activity. <h3>Conclusions</h3> Ultasonography of SI joint is a sensitive way of assessing response to NSAID use in Spondyloarthropathy patients and may be used as an objective tool in monitoring disease activity. <h3>References</h3> Sieper J, van der Heijde D. Non-radiographic Spondyloarthritis: New definition of an old disease. Arthritis &amp; Rheumatism 2013 March; 65(3): 543–551. Ghosh A,Mondal S,Sinha D, Nag A, Chakraborty S. Ultrasonography as a useful modality for documenting sacroiliitis in radiographically negative inflammatory back pain: a comparative evaluation with MRI. Rheumatology (2014); 53 (11):2030-2034. <h3>Acknowledgements</h3> Dr. Sumit Chakraborty, Department of Radiology, IPGME&amp;R, Kolkata, West Bengal. <h3>Disclosure of Interest</h3> None declared