MRI Quantification of Liver Fibrosis Using Diamagnetic Susceptibility: An Ex Vivo Validation Study

Area of Science:

• Magnetic Resonance Imaging
• Medical Imaging
• Hepatology

Background:

• Liver fibrosis progression can lead to cirrhosis and cancer.
• Current liver biopsy for staging is invasive and carries risks.
• Need for a noninvasive method to quantify liver fibrosis.

Purpose of the Study:

• Develop a noninvasive method for liver fibrosis quantification.
• Utilize diamagnetic susceptibility from multi-echo gradient echo (mGRE) data.
• Integrate magnitude decay R2* and phase quantitative susceptibility mapping (QSM) modeling.

Main Methods:

• Processed ex vivo liver explant mGRE data with fat-water separation.
• Separated susceptibility sources to measure diamagnetic fibrosis.
• Compared negative susceptibility maps with other MRI parameters against pathology in 20 explant sections.

Main Results:

• Negative susceptibility differentiated fibrosis stages (F0-F1 vs. F2-F3, p=0.0025; F2-F3 vs. F4, p=0.021).
• Achieved 90% sensitivity and 90% specificity for advanced fibrosis/cirrhosis (F3-F4) with 0.88 AUC (p=0.0017).
• Negative susceptibility sources positively correlated with fibrosis stage (r=0.60).

Conclusions:

• Negative susceptibility outperformed R2*, QSM, and PDFF for fibrosis staging.
• Negative susceptibility is a promising tool for noninvasive MRI staging of liver fibrosis.
• This method could improve patient management and reduce invasive procedures.