Enhanced B1 Mapping Technique Improves SNR in MRI

Jörg Felder, Markus Zimmermann, N. Jon Shah

27th October 2024

Researchers from INM-4 at Forschungszentrum Jülich have demonstrated a new method for acquiring high signal-to-noise ratio (SNR) B+1 maps, which is critical for MRI applications, especially in the design and calibration of advanced parallel-transmit arrays. This innovative approach combines gradient echo data with a specialized image reconstruction technique, leveraging the ESPIRiT algorithm—commonly used in parallel imaging—to produce high-quality efficiency maps without additional measurements.

This ESPIRiT-based method offers substantial improvements in noise suppression, allowing faster, high-resolution mapping that surpasses previous methods. Such enhanced SNR capabilities are especially valuable in the construction of transmit arrays, where it supports efficient calibration and validation of the required simulation models. Open-source resources, including the BART toolbox, streamline the adoption of this technique, making it practical for integration into MRI workflows.

With this advance, the team aims to simplify the development and application of parallel-transmit MRI technology, ultimately enhancing the fidelity of clinical and research imaging. Future studies are planned to expand this approach to use the unique phase properties of the method to improve stability in parallel transmit pulse design.

Original publication: High dynamic range mapping for the evaluation of parallel transmit arrays