Quantification of cardiac iron in patients with thalassemia with 3-T MRI calibrated by 1.5-T MRI

Area of Science:

• Cardiovascular Imaging
• Magnetic Resonance Imaging
• Hematology

Background:

• Assessing cardiac iron load is crucial for managing thalassemia.
• Standardized T2* cutoff values at 3 Tesla (3T) for cardiac iron assessment were previously unclear due to small sample sizes.
• Limited data existed for moderate to severe cardiac iron overload at 3T.

Purpose of the Study:

• To evaluate the feasibility, reproducibility, and reliability of T2* values for quantifying cardiac iron load in thalassemia patients using 3T MRI.
• To establish a standardized reference range for T2* measurements at 3T.

Main Methods:

• 122 thalassemia patients underwent cardiac T2* MRI at both 1.5T and 3T.
• Linear regression analysis correlated R2* (1000/T2*) values at 3T with those at 1.5T to derive a prediction equation.
• The derived equation was validated on 22 independent cases.

Main Results:

• A strong linear relationship (r=0.830, P<0.001) was observed between R2* values at 1.5T and 3T.
• The prediction equation yielded cutoff values for cardiac iron overload (<10 ms) and severe overload (<6 ms) at 3T.
• Diagnostic accuracy for different iron overload levels reached 95.5% and 100.0% in the validation cohort.

Conclusions:

• T2* quantification of cardiac iron load at 3T MRI is feasible, reproducible, and reliable.
• This method provides a standardized approach for assessing cardiac iron in thalassemia.
• 3T MRI offers a dependable tool for managing iron overload in these patients.