An NMR phased array for human cardiac 31P spectroscopy.

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Cardiovascular Spectroscopy

Background:

• Phosphorus-31 (31P) Magnetic Resonance Spectroscopy (MRS) is crucial for assessing myocardial metabolism.
• Current 31P MRS techniques face limitations in signal-to-noise ratio (SNR) and field of view, hindering comprehensive cardiac analysis.
• Optimizing receiver coil design is essential for advancing in vivo cardiac 31P MRS.

Purpose of the Study:

• To evaluate a novel four-coil phased-array 31P NMR receiver for human cardiac applications.
• To determine if this phased-array system can achieve high SNR and a large field of view comparable to 1H imaging.
• To assess the feasibility of in vivo 31P spectroscopy with enhanced spatial coverage and sensitivity.

Main Methods:

• Design and testing of a four-coil phased-array 31P NMR receiver.
• Acquisition of 31P spectra using one- and two-dimensional phase-encoding pulse sequences.
• Optimal combination of data from overlapping surface coils to create composite spectroscopic images.

Main Results:

• The phased-array receiver provided useful 31P spectra from a 2.5-fold wider lateral region around the anterior myocardium compared to a single coil.
• Sensitive depth was increased by up to 2 cm over a single coil.
• Combined spectra showed a 30% higher SNR on average, with some voxels exhibiting up to a 60% increase, without increasing imaging time.

Conclusions:

• The four-coil phased-array 31P NMR receiver significantly enhances in vivo cardiac spectroscopy.
• This technology offers improved spatial coverage and SNR, enabling more detailed metabolic assessment of the human heart.
• The developed system holds promise for advancing cardiovascular research and clinical diagnostics.