OBJECTIVE: To investigate the use of a quantitative diffusion-weighted imaging (DWI) tool for measuring @entity32 of the sacroiliac joints (SIJs) in enthesitis-related @entity625 (ERA). METHODS: A retrospective study was performed with institutional review board approval. Subjects were adolescents who had undergone MRI of the SIJs since January 2010. 10 @entity1 with a clinical diagnosis of ERA and 10 controls with a clinical diagnosis of mechanical back @entity158 were assessed. Axial T1 weighted, short tau inversion recovery (STIR) and DWI (b-values 0, 50, 100, 300 and 600   mm(2)   s(-1)) images were acquired. Apparent diffusion coefficient (ADC) maps were generated using a monoexponential fit. On each of four slices, two to three linear regions-of-interest were placed on each joint. Normalized ADC (nADC) values were defined as joint ADC divided by a reference ADC derived from normal sacral bone. STIR images were scored using a modification of an established technique. The correlation between nADC values and STIR scores was evaluated using Spearman's rank correlation. RESULTS: Mean nADC values were significantly higher in cases than in controls (p   =   0.0015). There was a strong correlation between STIR scores and nADC values (R   =   0.85). CONCLUSION: ADC values are significantly increased in inflamed SIJs compared with controls. There is a good correlation between this diffusion-based method and STIR scores of @entity32 . Advances in knowledge: We have described and provisionally validated a method for quantifying the severity of @entity32 in the SIJs in ERA using ADC measurements. This method is quick, is reproducible and could potentially be automated.

A diffusion-based quantification technique for assessment of sacroiliitis in adolescents with enthesitis-related XXXX .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity32 :: ('MESH:D007249', 'Disease') :: ['inflammation'] @entity625 :: ('MESH:D001168', 'Disease') :: ['arthritis'] @entity158 :: ('MESH:D010146', 'Disease') :: ['pain']
@entity625 :: (MESH:D001168,Disease) :: ['arthritis']
