MRI: the new reference standard in quantifying hepatic steatosis?

Area of Science:

• Medical Imaging
• Hepatology
• Biomedical Engineering

Background:

• Non-invasive assessment of intrahepatic fat is crucial for diagnosing and managing liver diseases.
• Current methods like Computed Tomography (CT) and pathologist assessments have limitations in accuracy and invasiveness.

Purpose of the Study:

• To evaluate non-invasive imaging techniques, specifically MRI and CT, for quantifying liver fat.
• To compare imaging-based fat quantification with chemical lipid assays and pathologist assessments.
• To correlate hepatic steatosis assessed by MRI with liver injury and patient outcomes.

Main Methods:

• Developed liver/fat phantoms to test MRI and CT accuracy.
• Correlated small-animal and human MRI/CT fat quantification with chemical lipid analysis in leptin-deficient mouse livers.
• Compared pathologist and automated software fat quantification with lipid assay.
• Assessed MRI correlation with liver injury in an ischemia/reperfusion model and postoperative complications in liver resection patients.

Main Results:

• MRI demonstrated high accuracy in detecting and quantifying fat in phantoms and mouse livers, correlating strongly with chemical lipid analysis (r=0.975).
• Human CT, pathologist, and automated software showed lower reliability in fat quantification.
• MRI-quantified fat significantly correlated with liver injury parameters and predicted mouse survival post-injury.
• In patients, higher liver fat content predicted more severe postoperative complications.

Conclusions:

• MRI provides an accurate, non-invasive method for predicting intrahepatic fat content using biological standards.
• MRI offers a representative assessment of the entire liver, surpassing the limitations of invasive biopsies.