Prospective characterization of intestinal MRI intravoxel incoherent motion in pediatric and young adult patients with newly diagnosed small bowel Crohn's disease

Vinicius de Padua V Alves; Neeraja Mahalingam; Jean A Tkach; Alexander J Towbin; Rebecca Imbus; Lee A Denson; Jonathan R Dillman

doi:10.1007/s00261-024-04318-4

Prospective characterization of intestinal MRI intravoxel incoherent motion in pediatric and young adult patients with newly diagnosed small bowel Crohn's disease

Abdom Radiol (NY). 2024 May 9. doi: 10.1007/s00261-024-04318-4. Online ahead of print.

Authors

Vinicius de Padua V Alves¹, Neeraja Mahalingam², Jean A Tkach^{2

3}, Alexander J Towbin^{2

3}, Rebecca Imbus², Lee A Denson^{4

5}, Jonathan R Dillman^{2

3}

Affiliations

¹ Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA. vinpvalves@gmail.com.
² Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA.
³ Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
⁴ Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
⁵ Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital, Cincinnati, OH, USA.

PMID: 38724774
DOI: 10.1007/s00261-024-04318-4

Abstract

Background: MRI diffusion-weighted imaging (DWI) is commonly used in MR enterography protocols for assessment of intestinal inflammation in patients with Crohn's disease. The intravoxel incoherent motion (IVIM) approach to DWI has been proposed as a more objective approach, providing quantitative parameters that reflect water diffusivity (D), blood flow (D*), and perfusion fraction (f).

Purpose: We aimed to determine if DWI-IVIM metrics from the terminal ileum in patients with newly diagnosed Crohn's disease differ from healthy participants and change in response to biologic medical therapy.

Methods: In this prospective case-control study, 20 consecutive pediatric patients (mean age = 14 years ± 2 [SD]; eight females) with newly diagnosed ileal Crohn's disease and 15 pediatric healthy participants (mean age = 18 years ± 4 [SD]; eight females) underwent research MRI examinations of the small bowel between 12/2018 and 10/2021. Participants with Crohn's disease underwent MR studies at baseline, 6 weeks, and 6 months following initiation of anti-TNF-alpha therapy, whereas control participants underwent one research MRI examination. The MRI protocol included a DWI-IVIM sequence with nine b-values and the IVIM parameters (D, D*, and f) were extracted. Unpaired t-tests and mixed-effects models were used for analyses.

Results: Mean IVIM D (P < 0.001), D* (P = 0.004), and f (P = 0.001) metrics were lower for Crohn's patients at the time of diagnosis compared to healthy participants. Mean IVIM f value increased over time in response to medical therapy (mean f at baseline, 22% ± 6%; 6 weeks, 25% ± 7%; 6 months, 29% ± 10%; P = 0.016). Mean IVIM D* value increased over time in response to treatment (mean D* at baseline, 10.9 ± 3.0 × 10^-3 mm²/s; 6 weeks, 11.8 ± 2.8 × 10^-3 mm²/s; 6 months, 13.3 ± 3.3 × 10^-3 mm²/s; P = 0.047), while there was no significant change in mean IVIM D value (P = 0.10).

Conclusion: MRI DWI-IVIM metrics in patients with ileal Crohn's disease change over time in response to biological therapy and help discriminate these patients from healthy participants.

Keywords: Adolescents; Children; Crohn’s disease; Intravoxel incoherent motion; Magnetic resonance imaging.

Grants and funding

5R21DK114657-02/Foundation for the National Institutes of Health