Kanimozhi Vendhan MBBS, FRCR, Abstract Co-Author: Nothing to Disclose

Timothy James Bray MBBCHIR, MA, Presenter: Nothing to Disclose

David Atkinson, Abstract Co-Author: Nothing to Disclose

Corinne Fisher, Abstract Co-Author: Nothing to Disclose

Debajit Sen, Abstract Co-Author: Nothing to Disclose

Yiannakis Ioannou, Abstract Co-Author: Nothing to Disclose

Margaret Anne Hall-Craggs MD, Abstract Co-Author: Nothing to Disclose

To use diffusion weighted images to quantify inflammation of the sacroiliac joints in adolescents with enthesitis related arthritis (ERA) and to correlate this with the conventional STIR inflammation score.  

We performed a retrospective case control study on 20 patients (10 ERA cases; 10 controls with mechanical back pain). All patients had conventional MRI of the sacroiliac joints along with diffusion weighted MRI. The anonymised images were exported to Matlab for analysis. The STIR scoring was performed by two readers and was based on a modification of an established scoring system used in adults with ankylosing spondylitis. Inflammation was also scored on the ADC maps using a methodology previously developed and piloted by our research group. In this technique the synovial portion of the SIJs are evaluated using multiple linear regions of interest (ROI). A profile of ADC values are obtained across each of those ROIs. Disease severity and extent were quantified using ‘integrated normalised ADC value’ – a summation of normalised ADC values along the standarised 14mm line profile expressed as 10-6 mm2s-1 x mm.

There was a highly significant difference in mean integrated ADC values between cases (8000 x 10-6 mm2s-1 x mm) and controls (2000 x 10-6 mm2s-1 x mm). There was good agreement in STIR scores between the two observers as shown by an intra-class correlation value of 0.96 for controls and 0.94 for cases. Pearson correlation was used to examine the association between the STIR scores and the average integrated ADC values. For cases, the Pearson correlation coefficient was 0.89 and for controls it was 0.82. This suggests a highly significant association between the two scores.

This data shows clear separation between normal subcortical bone and areas of inflammation using ‘integrated normalised ADC’ scores obtained from ADC maps. It has the potential to serve as a quantitative tool to assess sacroiliitis.

This technique can be used to assess change in ADC scores with treatment and to determine if there is a significant difference in scores between ERA patients treated with disease modifying anti-rheumatic drugs and those treated with anti- TNF agents.

http://media.rsna.org/media/abstract/2014/14014844/VSPD21-07 sec.pdf

Vendhan, K, Bray, T, Atkinson, D, Fisher, C, Sen, D, Ioannou, Y, Hall-Craggs, M, The Use of DWI to Quantify Sacroiliitis in Adolescents with Enthesitis-related Arthritis (ERA) and Correlation with Conventional STIR Score.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014844.html