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

Area of Science:

• Pediatric Radiology
• Medical Imaging
• Biomedical Engineering

Background:

• Pediatric pancreatic fat quantification using MRI is challenged by breath-holds (BH).
• Current methods like full segmentation (FS) or region of interest (ROI) analysis may not capture pancreatic fat's spatial heterogeneity, potentially limiting accuracy.

Purpose of the Study:

• To enhance MRI techniques for quantifying pediatric pancreatic proton-density fat fraction (pPDFF).
• Investigate free-breathing MRI (FB-MRI) for improved acquisition.
• Characterize pPDFF spatial heterogeneity and its correlation with clinical markers.

Main Methods:

• Prospective study involving 34 children (16 healthy, 18 overweight).
• Utilized 3T multiecho gradient-echo 3D stack-of-stars FB-MRI and Cartesian BH-MRI sequences.
• Assessed FS- and ROI-based pPDFF on FB-MRI and BH-MRI, including regional analysis (head, body, tail) and correlation with hemoglobin A1c.

Main Results:

• FB-MRI and BH-MRI showed comparable FS-pPDFF (mean difference 0.4%, CCC 0.95).
• FS-pPDFF was significantly higher than ROI-pPDFF (10.4% vs. 4.2%).
• Tail pPDFF was highest, and head/body pPDFF correlated positively with hemoglobin A1c.

Conclusions:

• FB-MRI provides reliable pPDFF measurements comparable to BH-MRI in children.
• Pancreatic fat quantification is influenced by spatial heterogeneity.
• Regional pPDFF in the pancreatic head and body correlates with hemoglobin A1c, indicating potential clinical relevance.