Using Free-Breathing MRI to Quantify Pancreatic Fat and Investigate Spatial Heterogeneity in Children

Jacob D Story; Shahnaz Ghahremani; Sevgi Gokce Kafali; Shu-Fu Shih; Kelsey J Kuwahara; Kara L Calkins; Holden H Wu

doi:10.1002/jmri.28337

Using Free-Breathing MRI to Quantify Pancreatic Fat and Investigate Spatial Heterogeneity in Children

J Magn Reson Imaging. 2023 Feb;57(2):508-518. doi: 10.1002/jmri.28337. Epub 2022 Jul 1.

Authors

Jacob D Story¹, Shahnaz Ghahremani², Sevgi Gokce Kafali^{2

3}, Shu-Fu Shih^{2

3}, Kelsey J Kuwahara¹, Kara L Calkins⁴, Holden H Wu^{2

3}

Affiliations

¹ David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
² Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
³ Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA.
⁴ Department of Pediatrics, Division of Neonatology and Developmental Biology, and the UCLA Children's Discovery and Innovation Institute, University of California Los Angeles, Los Angeles, California, USA.

Abstract

Background: MRI acquisition for pediatric pancreatic fat quantification is limited by breath-holds (BH). Full segmentation (FS) or small region of interest (ROI) analysis methods may not account for pancreatic fat spatial heterogeneity, which may limit accuracy.

Purpose: To improve MRI acquisition and analysis for quantifying pancreatic proton-density fat fraction (pPDFF) in children by investigating free-breathing (FB)-MRI, characterizing pPDFF spatial heterogeneity, and relating pPDFF to clinical markers.

Study type: Prospective.

Population: A total of 34 children, including healthy (N = 16, 8 female) and overweight (N = 18, 5 female) subjects.

Field strength and sequences: 3 T; multiecho gradient-echo three-dimensional (3D) stack-of-stars FB-MRI, multiecho gradient-echo 3D Cartesian BH-MRI.

Assessment: A radiologist measured FS- and ROI-based pPDFF on FB-MRI and BH-MRI PDFF maps, with anatomical images as references. Regional pPDFF in the pancreatic head, body, and tail were measured on FB-MRI. FS-pPDFF, ROI-pPDFF, and regional pPDFF were compared, and related to clinical markers, including hemoglobin A1c.

Statistical tests: T-test, Bland-Altman analysis, Lin's concordance correlation coefficient (CCC), one-way analysis of variance, and Spearman's rank correlation coefficient were used. P < 0.05 was considered significant.

Results: FS-pPDFF and ROI-pPDFF from FB-MRI and BH-MRI had mean difference = 0.4%; CCC was 0.95 for FS-pPDFF and 0.62 for ROI-pPDFF. FS-pPDFF was higher than ROI-pPDFF (10.4% ± 6.4% vs. 4.2% ± 2.8%). Tail-pPDFF (11.6% ± 8.1%) was higher than body-pPDFF (8.9% ± 6.3%) and head-pPDFF (8.7% ± 5.2%). Head-pPDFF and body-pPDFF positively correlated with hemoglobin A1c.

Data conclusion: FB-MRI pPDFF is comparable to BH-MRI. Spatial heterogeneity affects pPDFF quantification. Regional measurements of pPDFF in the head and body were correlated with hemoglobin A1c, a marker of insulin sensitivity.

Evidence level: 2 TECHNICAL EFFICACY: Stage 2.

Keywords: free-breathing MRI; metabolic syndrome; pancreatic fat; pediatric obesity; proton-density fat fraction.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Biomarkers
Child
Female
Glycated Hemoglobin
Humans
Image Interpretation, Computer-Assisted* / methods
Liver
Magnetic Resonance Imaging* / methods
Prospective Studies
Protons

Substances

Glycated Hemoglobin
Protons
Biomarkers

Abstract

Publication types

MeSH terms

Substances

Grants and funding