Test–retest assessment of non-contrast MRI sequences to characterise and quantify the small bowel wall in healthy participants

Abstract

Objective Quantitative Magnetic Resonance Imaging sequences have been investigated as objective imaging biomarkers of fibrosis and inflammation in Crohn’s disease. Aim To determine the repeatability and inter- and intra-observer agreement of these measures in the prepared small bowel wall. Methods Ten healthy participants were scanned at 3 T on 2 separate occasions using T1 and T2 relaxometry, IVIM-DWI and MT sequences. Test–retest repeatability was assessed using the coefficient of variation (CoV) and intra-class correlation coefficients (ICCs) were used to evaluate the intra- and inter-observer agreement Results Test–retest repeatability in the bowel wall was excellent for apparent diffusion coefficient (ADC), magnetisation transfer ratio (MTR), T1, and diffusion coefficient D (CoV 5%, 7%, 8%, and 10%, respectively), good for perfusion fraction (PF) (CoV 20%) and acceptable for T2 (CoV 21%). Inter-observer agreement was good for the T2, D and ADC (ICC = 0.89, 0.86, 0.76, respectively) and moderate for T1 (ICC = 0.55). Intra-observer agreement was similar to inter-observer agreement. Discussion This study showed variable results between the different parameters measured. Test–retest repeatability was at least acceptable for all parameters except pseudo-diffusion coefficient D*. Good inter- and intra-observer agreement was obtained for T2, ADC and D, with these parameters performing best in this technical validation study.

Differentiating active from Inactive Sacroiliitis in ankylosing spondylitis by combination of DWI and Magnetization Transfer Imaging

“…As inflammation progresses, MTR could even reduce to close to zero. 18 In this study, the MTRc in the active group was significantly lower than that in the inactive group, which is consistent with previous conclusions. 6 MTRc has better sensitivity than ADC (BME) and ADC(NABM) but lower specificity.…”

Multispectral optoacoustic tomography of the human intestine – temporal precision and the influence of postprandial gastrointestinal blood flow

“…But, pertaining to CVs, the variation across the two examination days was smaller than the variation between individuals. These findings are in accordance with MRI data of the healthy intestine with similar temporal and individual variability [27] , and preclinical MSOT data of murine spleens and kidneys [28] . The between-day reproducibility of MRI and MSOT signals of healthy intestine might be predominantly challenged by the difficulty of exact anatomical relocation due to missing fixed landmarks, intestinal motility, gas overlay and stool filling.…”