Time-efficient, high-resolution 3T whole-brain relaxometry using Cartesian 3D MR Spin TomogrAphy in Time-Domain...

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging (MRI)
• Neuroimaging

Background:

• Current 3D MR Spin Tomography in Time-Domain (MR-STAT) protocols are susceptible to cerebrospinal fluid (CSF) pulsation artifacts.
• These artifacts degrade the quality of quantitative maps in brain imaging.

Purpose of the Study:

• To develop and validate a novel 3D MR-STAT protocol for whole-brain relaxometry.
• To overcome challenges posed by CSF-induced ghosting artifacts in brain MR-STAT imaging.

Main Methods:

• Optimization of the flip-angle train within the Cartesian 3D MR-STAT framework.
• Minimization of noise and reduction of CSF-to-white-matter signal ratio for artifact suppression.
• Validation using a gel/water phantom and in vivo experiments on healthy volunteers.

Main Results:

• An optimized sequence demonstrated high parameter-encoding capability and low CSF signal response.
• In vivo experiments showed no CSF artifacts and improved image quality compared to baseline.
• Low intersubject and interscan variability (1.6%-4.6%) for T1 and T2 parameters in gray and white matter.

Conclusions:

• A new 3D MR-STAT sequence with effective CSF suppression was developed.
• The sequence eliminates CSF pulsation artifacts, ensuring high-quality, 1-mm³ whole-brain relaxometry.
• Achieved rapid 5.5-minute scan time for comprehensive brain relaxometry.