Published in:
Open Access 01-12-2015 | Technical Report
Feasibility of diffusion-weighted magnetic resonance imaging in patients with juvenile idiopathic arthritis on 1.0-T open-bore MRI
Published in: Skeletal Radiology | Issue 12/2015
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Objective
To evaluate the feasibility of non-invasive diffusion-weighted imaging (DWI) of the knee of children with juvenile idiopathic arthritis (JIA) and, further, to analyze the apparent diffusion coefficient (ADC) levels to distinguish synovium from effusion.
Materials and methods
Standard magnetic resonance imaging of the knee including post-contrast imaging was obtained in eight patients (mean age, 12 years 8 months, five females) using an open-bore magnetic resonance imaging system (1.0 T). In addition, axially acquired echo-planar DWI datasets (b-values 0, 50, and 600) were prospectively obtained and the diffusion images were post-processed into ADC50–600 maps. Two independent observers selected a region of interest (ROI) for both synovium and effusion using aligned post-contrast images as landmarks. Mann–Whitney U test was performed to compare ADC synovium and ADC effusion.
Results
DWI was successfully obtained in all patients. When data of both observers was combined, ADC synovium was lower than ADC effusion in the ROI in seven out of eight patients (median, 1.92 × 10−3 mm2/s vs. 2.40 × 10−3 mm2/s, p = 0.006, respectively). Similar results were obtained when the two observers were analyzed separately (observer 1: p = 0.006, observer 2: p = 0.04).
Conclusions
In this pilot study, on a patient-friendly 1.0-T open-bore MRI, we demonstrated that DWI may potentially be a feasible non-invasive imaging technique in children with JIA. We could differentiate synovium from effusion in seven out of eight patients based on the ADC of synovium and effusion. However, to select synovium and effusion on DWI, post-contrast images were still a necessity.