Publications (2)6.19 Total impact
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Article: Quantified terminal ileal motility during MR enterography as a potential biomarker of Crohn's disease activity: a preliminary study.
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ABSTRACT: To compare quantified terminal ileal (TI) motility during MR enterography (MRE) with histopathological severity of acute inflammation in Crohn's disease. A total of 28 Crohn's patients underwent MRE and endoscopic TI biopsy. Axial and coronal TrueFISP, HASTE and post-gadolinium VIBE images were supplemented by multiple coronal TrueFISP cine motility sequences through the small bowel volume. TI motility index (MI) was quantified using validated software; an acute inflammation score (eAIS; 0-6) was assigned to the biopsy. Two observers qualitatively scored mural thickness, T2 signal, contrast enhancement and perimural oedema (0-3) to produce an activity score (aMRIs) based on anatomical MRI. The association among the MI, eAIS and aMRIs was tested using Spearman's rank correlation. Wilcoxon rank sum test compared motility in subjects with and without histopathological inflammation. Mean MI and mean eAIS were 0.27 (range 0.06-0.55) and 1.5 (range 0-5), respectively. There was a significant difference in MI between non-inflamed (mean 0.37, range 0.13-0.55) and inflamed (mean 0.19, range 0.06-0.44) TI, P = 0.002, and a significant negative correlation between MI and both eAIS (Rho = -0.52, P = 0.005) and aMRIs (R = -0.7, P < 0.001). Quantified TI motility negatively correlates with histopathological measures of disease activity and existing anatomical MRI activity biomarkers. • Magnetic resonance imaging is increasingly used to assess Crohn's disease. • MRI measurements can provide a quantitative assessment of small bowel motility. • MR enterography can grade Crohn's disease. • Small bowel motility can be used as a marker of inflammatory activity.European Radiology 06/2012; 22(11):2494-501. · 3.22 Impact Factor -
Article: Quantitative assessment of small bowel motility by nonrigid registration of dynamic MR images.
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ABSTRACT: Evaluation of small bowel motility from two-dimensional dynamic MRI is of increasing interest for the assessment of segmental diseases such as Crohn's disease. We propose to use nonrigid image registration for automated motility analysis. Registration is particularly difficult when localized intensity changes occur (e.g., due to intraluminal flow or through-plane motion). Therefore, displacements were extracted using a joint registration and modeling of intensity changes. Results were analyzed in 10 patients with known or suspected Crohn's disease. Bowel wall displacements were assessed by tracking bowel cross-sectional markers over time. Automated tracking with the proposed technique was in good agreement with manual tracking (similar bias, improved standard deviations). The ability to quantify different grades of bowel motility was investigated by comparing direct motion measures (i.e., changes in bowel cross-sectional diameter or area) and various parametric maps, e.g., based on the Jacobian of the measured displacements with expert grading. Among these measures, the standard deviation over time of the Jacobian was the best at predicting grades from 1 (moving normally) to 4 (not moving at all) in 50 bowel regions with normal and pathologically reduced motility, yielding 93% correct classification with a 1-class tolerance (i.e., same score as the expert ± 1).Magnetic Resonance in Medicine 01/2012; 68(3):783-93. · 2.96 Impact Factor
