Henning Neubauer MD, MBA, Presenter: Nothing to Disclose

Annette Holl-Wieden, Abstract Co-Author: Nothing to Disclose

Nicole Hassold MD, Abstract Co-Author: Nothing to Disclose

Thomas Alois Pabst PhD, Abstract Co-Author: Nothing to Disclose

Thorsten Alexander Bley MD, Abstract Co-Author: Nothing to Disclose

Contrast-enhanced (ce-)T1w MRI is the current diagnostic standard for imaging synovitis in arthritis joints aiming at early diagnosis and sensitive therapy surveillance. Native MR imaging techniques for synovitis have been a focus of research for concerns of patient safety and cost. We evaluated diffusion-weighted MRI (DWI) as a novel technique for imaging of synovitis in young patients with gonarthritis.

Twenty-five children and adolescents (age 11±5 years, 13 females) with clinically suspected gonarthritis and nine age-matched controls underwent routine MRI, including transversal ce-T1w and single-shot echoplanar diffusion-weighted imaging (SS-EPI DWI, two b-values 0-50 and 800-1000 s2/mm, slice thickness 4-6 mm, 1.8 x 1.8 mm in-plane resolution, 2-6 averages, acquisition time 41 s to 190 s). DWI and ce-T1w images were evaluated for the presence of synovitis. Signal intensity ratios were calculated for synovia vs. bone marrow and synovia vs. effusion.

All examinations yielded diagnostic image quality. All patients showed synovial thickening and contrast enhancement on ce-T1w and corresponding synovial signal increase on DWI at high b-values. Mean total ADC was 2.2±0.5 (*10-3 mm2/s) for synovitis and 2.8±0.4 for joint effusion. Mean signal intensity (SI) ratios were 5.4 (ce-T1w) vs. 9.1 (DWI) for SI (synovitis/bone marrow) and 4.8 (ce-T1w) vs. 1.5 (DWI) for SI (synovitis/effusion). There were no false-positive cases among controls.

Diffusion-weighted MRI reliably visualises synovitis of the knee joint based on altered tissue diffusivity and presents a novel approach to imaging of synovitis without application of i.v. contrast agent. A combination of DWI with dark-fluid techniques should be evaluated to further improve the delineation of synovitis in the presence of joint effusion.

Imaging synovitis with diffusion-weighted MRI holds potential to increase patient safety, to streamline scan protocols and to reduce costs and thus deserves further evaluation.

Neubauer, H, Holl-Wieden, A, Hassold, N, Pabst, T, Bley, T, Diffusion-weighted MRI in Paediatric Patients with Gonarthritis: A Novel Approach to Imaging of Synovitis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010339.html