Role of Diffusion-weighted and Contrast-enhanced Magnetic Resonance Imaging in Differentiating Activity of Ankylosing Spondylitis

Abstract

Background:Previous studies showed that combining apparent diffusion coefficient (ADC) value with the Spondyloarthritis Research Consortium of Canada (SPARCC) index value might provide a reliable evaluation of the activity of ankylosing spondylitis (AS), and that contrast-enhanced (CE) magnetic resonance imaging (MRI) is unnecessary. However, the results were based on confirming only a small random sample. This study aimed to assess the role of CE-MRI in differentiating the disease activity of AS by comparing ADC value with a large sample.Methods:A total of 115 patients with AS were enrolled in accordance with Bath AS Disease Activity Index and laboratory indices, and 115 patients were divided into two groups, including active group (n = 69) and inactive group (n = 46). SPARCC, ΔSI, and ADC values were obtained from the short tau inversion recovery (STIR), diffusion-weighted imaging (DWI), and CE-MRI, respectively. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters.Results:The optimal cutoff values (with sensitivity, specificity, respective area under the curve, positive likelihood ratio, and negative likelihood ratio) for the differentiation between active and inactive groups are as follows: SPARCC = 6 (72.06%, 82.61%, 0.836, 4.14, 0.34); ΔSI (%) = 153 (80.6%, 84.78%, 0.819, 5.3, 0.23); ADC value = 1.15 × 10−3 mm2/s (72.73%, 81.82%, 0.786, 4, 0.33). No statistical differences were found among the predictive values of SPARCC, ΔSI, and ADC. Multivariate analysis showed no significant difference between the combination of SPARCC and ADC values with and without ΔSI.Conclusions:Using large sample, we concluded that the combination of STIR and DWI would play significant roles in assessing the disease activity, and CE-MRI sequence is not routinely used in imaging of AS to avoid renal fibrosis and aggravation of kidney disease.

Diffusion kurtosis imaging in sacroiliitis to evaluate the activity of ankylosing spondylitis

“…In the current study, it was found that in active AS, bone marrow edema and increased vascular permeability caused an enlarged extracellular space and increased water molecular diffusion . Zhao et al reported that the ADC and D values derived from DWI and IVIM were increased in active AS, findings that were consistent with our findings . Previous studies have also showed that DWI‐derived ADC and IVIM‐derived D values were increased with decreased bone mineral density in AS patients.…”

“…3,12 Zhao et al reported that the ADC and D values derived from DWI and IVIM were increased in active AS, findings that were consistent with our findings. 15,26 Previous studies have also showed that DWI-derived ADC and IVIM-derived D values were increased with decreased bone mineral density in AS patients. The correlation between the ADC or D value and bone mineral density in AS patients requires further confirmation.…”

Recent advances in ankylosing spondylitis: understanding the disease and management

“…However, Zhao et al . 113 confirmed these results by using a large sample of patients, showing that the combination of short tau inversion recovery (STIR) and diffusion weighted imaging (DWI) in MRI is sufficient to monitor disease activity, avoiding the unnecessary use of contrast with its risks. Conversely, Bradbury et al .…”

The Brazilian Society of Rheumatology guidelines for axial spondyloarthritis – 2019

“…Regarding the SIJ MRI in the same cohort (SPACE), the use of an IV MRI contrast agent (gadolinium), which is essential for the detection of synovitis and/or capsulitis, failed to increase the sensitivity of the test compared with STIR alone, because these acute lesions were only observed in patients who also presented bone marrow edema (visible on STIR) [20] (2B). In addition, the acquisition of diffusionweighted images (DWI) is an alternative to the use of contrast agents, reducing the risk of nephrotoxicity, albeit without showing better performance than STIR imaging analyses [21,22] (2B).…”