A 3D trajectory for undersampling k-space in MRSI applications.

Area of Science:

• Medical Imaging
• Spectroscopy
• Biophysics

Background:

• Magnetic Resonance Spectroscopic Imaging (MRSI) is a noninvasive technique for spatially localized spectra.
• Reducing scan time while maintaining spatial resolution is a key challenge in MRSI.
• Existing fast 3D methods for MRSI are limited, with only stack of spirals and echo planar trajectories studied.

Purpose of the Study:

• To present a novel formulation for a fast, 3D k-space trajectory applicable to 3D MRSI.
• To demonstrate the method's ability to reduce scan times in 3D MRSI.
• To evaluate the method's applicability to regular 3D MRI and dynamic undersampled imaging.

Main Methods:

• A novel 3D k-space trajectory design based on rays expanding from k-space origin into a revolving sphere.
• Collection of spectral data for all 3D spatial k-space within a single scan.
• Application of the method to 3D MRSI and regular 3D MRI, including undersampled scenarios.

Main Results:

• The proposed method enables the collection of spectral data for all 3D spatial k-space.
• High-quality undersampled spectroscopic imaging is achievable in short scan times, facilitating compound recognition.
• The technique was successfully tested in both 3D MRSI and regular 3D MRI, showing potential for dynamic imaging.

Conclusions:

• The presented 3D k-space trajectory offers a simple and effective approach to accelerate 3D MRSI.
• This method allows for significant undersampling, leading to faster acquisition and reconstruction of high-quality spectroscopic images.
• The technique holds promise for dynamic undersampled imaging and standard 3D MRI applications.