Multi-site feasibility and reproducibility study on UTE 3D phosphorous MRSI using novel rosette trajectory (PETALUTE)

Area of Science:

• Magnetic Resonance Imaging
• Neuroimaging
• Metabolomics

Background:

• ³¹P Magnetic Resonance Spectroscopic Imaging (MRSI) is crucial for assessing brain metabolism.
• Existing methods face challenges in acquisition speed and resolution.
• Novel acquisition patterns are needed to improve clinical utility.

Purpose of the Study:

• To implement and validate a novel rosette k-space pattern for 3D Ultra-short Echo Time (UTE) ³¹P MRSI.
• To establish a robust, automated pipeline for data reconstruction and processing.
• To evaluate the clinical applicability and reproducibility of this technique across different scanner setups.

Main Methods:

• A multi-center feasibility study using a novel UTE ³¹P 3D MRSI sequence with a rosette petal trajectory (PETALUTE).
• Data acquired across three institutions on Siemens Prisma and Biograph mMR scanners.
• Healthy subjects underwent repeated measurements for spectral analysis using LCModel, with compressed sensing explored for acceleration.

Main Results:

• High-quality ³¹P MRSI spectra were obtained across different sites and hardware.
• Feasibility demonstrated with a 4x acceleration, reducing acquisition time to 6.75 minutes.
• Key metabolites like phosphocreatine (PCr) and adenosine triphosphate (ATP) showed low variability (<20%).

Conclusions:

• UTE ³¹P 3D rosette MRSI, coupled with compressed sensing and LCModel, enables clinically feasible, robust, high-resolution ³¹P MRSI.
• The technique is suitable for implementation on standard clinical MRI scanners.
• This advancement facilitates in vivo metabolic assessment in the brain.