Improved Myocardial Sodium Quantification at 7 T Using Interleaved ²³Na/¹H pTx MRI With Motion and Anatomy-Based B₁...

Area of Science:

• Cardiovascular Magnetic Resonance Imaging
• Sodium-23 MRI
• Quantitative Imaging

Background:

• Myocardial 23Na quantification at 7T is challenging due to motion and B1 field inhomogeneities.
• Accurate sodium imaging is crucial for assessing myocardial health and disease.

Purpose of the Study:

• To enhance the accuracy and repeatability of myocardial 23Na quantification in cardiac MRI at 7T.
• To implement a novel anatomy-based B1 bias field correction combined with motion correction.

Main Methods:

• A dual-nuclear interleaved 23Na/1H MRI sequence at 7T was utilized.
• 1H MR data enabled automated segmentation and motion correction.
• A novel anatomy-based B1 bias field correction was developed using 1H-derived segmentations.

Main Results:

• Combined motion and B1 corrections significantly improved myocardial sodium quantification repeatability (2.0 mM, 4.0%).
• The anatomy-based B1 correction outperformed phantom-based methods.
• Measured myocardial sodium concentration (49.5 ± 4.7 mM) aligns with literature values.

Conclusions:

• Retrospective motion correction and anatomy-based B1 correction enable repeatable myocardial sodium quantification at 7T.
• This approach provides a scalable framework for future clinical research using 1H MRI for corrections.