Multiphoton parallel transmission (MP-pTx): Pulse design methods and numerical validation.

ABSTRACT:

Purpose

We propose and evaluate multiphoton parallel transmission (MP-pTx) to mitigate flip angle inhomogeneities in high-field MRI. MP-pTx is an excitation method that utilizes a single, conventional birdcage coil supplemented with low-frequency (kHz) irradiation from a multichannel shim array and/or gradient channels. SAR analysis is simplified to that of a conventional birdcage coil, because only the radiofrequency (RF) field from the birdcage coil produces significant SAR.

Methods

MP-pTx employs an off-resonance RF pulse from a conventional birdcage coil supplemented with oscillating z$$ z $$ -directed fields from a multichannel shim array and/or the gradient coils. We simulate the ability of MP-pTx to create uniform nonselective brain excitations at 7 T using realistic

SUBMITTER: Drago JM 

PROVIDER: S-EPMC11262987 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature