Fast WASABI post-processing: Access to rapid B₀ and B₁ correction in clinical routine for CEST MRI

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Biomedical Engineering
• Medical Physics

Background:

• Chemical Exchange Saturation Transfer (CEST) MRI techniques, including amide proton transfer (APT) and nuclear Overhauser effect (NOE) imaging, offer significant diagnostic potential by accessing molecular tissue information.
• CEST MRI data quality is compromised by static magnetic B0 and radiofrequency B1 field inhomogeneities, necessitating artifact correction for reliable interpretation.
• The WASABI MRI protocol was previously developed to simultaneously map B0 and B1 field inhomogeneities, compatible with CEST MRI sequences.

Purpose of the Study:

• To develop a computationally accelerated post-processing method for WASABI MRI data.
• To enhance the clinical applicability of the WASABI protocol by reducing processing time without sacrificing accuracy or stability.

Main Methods:

• A novel, fast post-processing algorithm was developed for WASABI data analysis.
• The new method significantly accelerates the parameter estimation procedure compared to the previous exhaustive search and non-linear fitting approach.
• The stability and performance of the accelerated method were validated using phantom and in vivo 3 Tesla MRI data.

Main Results:

• The new post-processing method achieves outstanding acceleration of parameter estimation for WASABI data.
• The computational speed-up makes the WASABI technique practical for routine clinical use.
• The method demonstrated stable performance on both phantom and clinical 3 Tesla in vivo datasets.

Conclusions:

• The developed fast post-processing method significantly enhances the efficiency of the WASABI protocol.
• This advancement facilitates the clinical adoption of WASABI for accurate B0 and B1 field mapping in CEST MRI.
• The accelerated WASABI technique holds promise for improving diagnostic capabilities in clinical MRI settings.