Comparison of clinical MRI liver iron content measurements using signal intensity ratios, R ₂ and R ₂

Area of Science:

• Radiology
• Medical Imaging
• Hepatology

Background:

• Accurate liver iron content (LIC) measurement is crucial for managing iron overload disorders.
• Magnetic Resonance Imaging (MRI) offers non-invasive methods for LIC assessment.
• Routine clinical practice involves various MRI techniques for LIC quantification.

Purpose of the Study:

• To compare the clinical utility of three MRI-based liver iron content (LIC) measurement techniques.
• To evaluate the success rates and diagnostic accuracy of signal intensity ratio (SIR), R2, and R2* methods.
• To determine the most suitable MRI method for routine LIC assessment over a 6-year period.

Main Methods:

• Retrospective analysis of 114 patients undergoing 1.5T MRI for LIC measurement (2008-2013).
• Comparison of signal intensity ratio (SIR), MR-relaxometry (R2 and R2*) methods for LIC quantification.
• Assessment of success rates, interobserver agreement (ICC), and diagnostic accuracy (ROC analysis) against elevated R2*.

Main Results:

• Successful LIC data acquisition rates were 89% for SIR, 62% for R2, and 98% for R2*.
• All methods demonstrated excellent interobserver agreement (ICC > 0.997).
• R2 and serum ferritin showed high diagnostic accuracy in detecting iron overload indicated by elevated R2*.

Conclusions:

• Signal intensity ratio (SIR) and R2* methods are preferable to R2 due to higher success rates in routine clinical practice.
• R2* is favored over SIR for MRI-based LIC measurement owing to its shorter acquisition time and wider measurable LIC range.
• MRI techniques, particularly R2*, provide reliable and efficient assessment of liver iron overload.