Assessment of Diffusion and Perfusion
Magnetic Resonance Imaging
Imaging Studies for Cardiovascular System IV: CMRI
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Updated: Jul 13, 2025

Novel In Vivo Micro-Computed Tomography Imaging Techniques for Assessing the Progression of Non-Alcoholic Fatty Liver Disease
Published on: March 24, 2023
Monchai Phonlakrai1,2, Saadallah Ramadan3,4, John Simpson5,6
1School of Health Sciences, College of Health, Medicine and Wellbeing, The University of Newcastle, Newcastle, NSW, Australia.
This study explores a non-contrast MRI technique to measure liver function. By using advanced diffusion imaging, researchers can assess tissue health and blood flow without needing injected dyes. This approach shows promise for identifying early liver impairment in patients, potentially improving treatment planning.
Area of Science:
Background:
Liver cirrhosis significantly alters organ performance and blood flow, yet current detection methods often rely on invasive procedures or contrast agents. No prior work had resolved whether non-invasive magnetic resonance imaging could accurately quantify these changes at a granular level. That uncertainty drove researchers to investigate advanced diffusion sequences for functional assessment. Prior research has shown that standard imaging often misses subtle early-stage damage. This gap motivated the exploration of multi-parametric approaches to improve diagnostic sensitivity. It was already known that tissue perfusion is a key indicator of hepatic health. However, the clinical utility of specific diffusion parameters remained largely unverified. This study addresses the need for reliable, contrast-free biomarkers in liver disease management.
Purpose Of The Study:
This study aimed to evaluate the feasibility of using non-contrast diffusion imaging for liver function assessment. The researchers sought to determine if these metrics could correlate with established multi-parametric magnetic resonance imaging methods. A primary motivation was the need for safer, non-invasive alternatives to contrast-enhanced procedures for patients with early impairment. The team investigated the variability of diffusion-derived parameters to ensure diagnostic reliability. They also examined whether these measurements could provide accurate data at the voxel level. By comparing healthy volunteers with patient groups, the authors intended to validate the sensitivity of their approach. This work addresses the clinical challenge of sparing healthy tissue during radiation therapy. The study ultimately explores the potential for these techniques to become standard diagnostic tools in hepatology.
Main Methods:
The research team implemented a multi-parametric imaging design to evaluate liver function. They utilized phantom models to establish baseline measurement stability before moving to human subjects. Ten healthy volunteers and twelve patients participated in the clinical phase of the investigation. The imaging protocol combined diffusion-weighted sequences with T1 mapping and contrast-enhanced scans. Researchers generated parametric maps to visualize tissue characteristics at the voxel level. Statistical comparisons between groups relied on the Mann-Whitney U test. Pearson correlation analysis assessed the relationship between non-contrast diffusion metrics and contrast-derived hepatic extraction fraction values. This comprehensive approach allowed for both global and pixel-based performance evaluation.
Main Results:
The study identified that perfusion fraction and pseudo-diffusion parameters effectively distinguish healthy liver function from mild impairment. Statistical analysis revealed significant p-values of 0.002 for perfusion fraction and less than 0.001 for pseudo-diffusion. These specific metrics demonstrated a moderate correlation with hepatic extraction fraction values within the patient cohort. Measurements in phantom models showed maximum coefficients of variation at 12.4% for apparent diffusion coefficient and 16.1% for T1 values. These findings confirm the feasibility of using non-contrast diffusion imaging for functional assessment. The data suggest that voxel-level analysis provides a granular view of tissue perfusion. Overall, the results support the potential of these parameters as non-invasive biomarkers. The findings highlight the consistency of the imaging protocol across different subjects.
Conclusions:
The authors demonstrate that specific diffusion-derived parameters offer a viable pathway for non-invasive hepatic assessment. These metrics successfully differentiate between healthy tissue and early-stage functional impairment. The findings suggest that perfusion-related variables correlate with established contrast-enhanced measurements at the voxel level. This synthesis implies that clinicians may eventually reduce reliance on exogenous agents for routine monitoring. The researchers highlight the potential for these techniques to guide radiation therapy planning by sparing healthy tissue. Future clinical workflows could incorporate these maps to improve patient outcomes. The study provides a foundation for validating these metrics in larger, diverse cohorts. These results establish a framework for using non-contrast imaging to track liver health over time.
The researchers propose that pseudo-diffusion and perfusion fraction parameters serve as markers for hepatic health. These metrics distinguish healthy tissue from impaired states with statistical significance, specifically p=0.002 for the perfusion fraction and p<0.001 for the pseudo-diffusion coefficient.
The team utilized a 13-b value intravoxel incoherent motion diffusion-weighted imaging sequence. This protocol generates parametric maps that allow for the calculation of pure diffusion, pseudo-diffusion, and perfusion fraction values without requiring contrast administration.
The authors employed B1-corrected dual flip angle T1 mapping to ensure accuracy. This technical necessity accounts for magnetic field inhomogeneities, which are required to produce reliable T1 maps during the multi-parametric examination process.
Gadoxatate low temporal resolution dynamic contrast-enhanced MRI provides the hepatic extraction fraction map. This data type acts as a reference standard to validate the correlations observed between the non-contrast diffusion parameters and actual liver function at the voxel level.
The researchers measured the coefficient of variation for apparent diffusion coefficient and T1 parameters. They observed maximum values of 12.4% and 16.1% respectively, confirming the stability of their measurements within the controlled phantom environment.
The authors propose that these non-contrast metrics could assist in radiation therapy liver-sparing treatments. By identifying regions of impaired function, clinicians may better protect healthy tissue during localized interventions for patients with early-stage disease.