Single-shot diffusion trace spectroscopic imaging using radial echo planar trajectories.

Area of Science:

• Magnetic Resonance Imaging
• Diffusion Tensor Imaging
• Spectroscopic Imaging

Background:

• Diffusion-weighted imaging (DWI) is crucial for characterizing tissue microstructure.
• Accurate quantification of apparent diffusion coefficient (ADC) is vital for various neurological applications.
• Conventional DWI methods can be time-consuming, limiting clinical utility.

Purpose of the Study:

• To demonstrate the feasibility of single-shot diffusion trace-weighted radial echo planar spectroscopic imaging (Trace DW-REPSI).
• To evaluate the performance of Trace DW-REPSI for quantifying trace ADC in phantoms and in vivo.
• To assess the potential for faster ADC quantification using this novel sequence.

Main Methods:

• Trace DW-REPSI datasets were acquired using a 3T scanner in phantoms and 10 healthy volunteers.
• Maximum b-value of 1601 s/mm² and diffusion time of 10.75 ms were employed.
• Radial acquisition self-navigation was utilized for phase and frequency correction.

Main Results:

• Phantom trace ADCs showed excellent agreement with reported values.
• In vivo ADCs correlated well with expected gray and white matter differences.
• Extrapolated trace ADCs for tNAA, tCr, and tCho in gray/white matter ranged from 0.18-0.27 and 0.26-0.38 μm²/ms, respectively.
• Overestimation of trace ADCs was attributed to the short diffusion time.

Conclusions:

• This study presents the first demonstration of the single-shot Trace DW-REPSI sequence.
• The Trace DW-REPSI sequence offers a significant reduction in scan time compared to conventional methods.
• This technique holds promise for efficient and accurate trace ADC estimation in clinical settings.