Faster and More Robust CK Reaction Rate Estimation at 3T Using Acquisition-Weighted ³¹P Cardiac 1D-MRSI With...

Area of Science:

• Cardiovascular Research
• Metabolic Imaging
• Magnetic Resonance Spectroscopy

Background:

• Quantifying the creatine kinase (CK) forward reaction rate (k_f) in the human heart is crucial for understanding cardiac metabolism.
• Current phosphorus magnetic resonance spectroscopy methods are limited by long acquisition times, operator subjectivity, and skeletal muscle contamination.

Purpose of the Study:

• To evaluate if combining compartment-based reconstruction techniques with acquisition-weighted (AW) Triple Repetition Time Saturation Transfer (TRiST) acquisitions can overcome limitations in cardiac k_f quantification.
• To assess the efficiency and accuracy of a novel TRiST protocol for in vivo cardiac metabolism evaluation.

Main Methods:

• Healthy volunteers underwent 3T MRI using fully weighted (FW) and AW TRiST protocols.
• Spectra were reconstructed using conventional Fourier Transform (FT) and compartment-based methods (SLAM, SLIM, ROI-FT).
• Cardiac k_f values were calculated and compared across reconstruction methods and acquisition types.

Main Results:

• No significant differences in cardiac k_f values were observed between FW and AW TRiST acquisitions across all reconstruction methods.
• Compartment-based reconstruction (SLAM, SLIM) showed a significant decrease in cardiac PCr/ATP ratios, indicating reduced skeletal muscle signal contamination.
• The combined AW acquisition and compartment-based reconstruction reduced scan times by 47%.

Conclusions:

• Compartment-based reconstruction techniques minimize operator subjectivity and skeletal muscle contamination in TRiST analysis.
• Combining AW acquisition with compartment-based reconstruction provides a robust and efficient method for in vivo cardiac metabolism evaluation.
• This novel approach enhances the clinical utility of phosphorus magnetic resonance spectroscopy for cardiac assessment.