Parallel transmit hybrid pulse design for controlled on-resonance magnetization transfer in R₁ mapping at 7T.

ABSTRACT:

Purpose

This work proposes a "hybrid" RF pulse design method for parallel transmit (pTx) systems to simultaneously control flip angle and root-mean-squared B 1 + $$ {\mathrm{B}}_1^{+} $$ ( B 1 rms $$ {B}_1^{\mathrm{rms}} $$ ). These pulses are generally only designed for flip angle, however, this can lead to uncontrolled B 1 rms $$ {B}_1^{\mathrm{rms}} $$ , which then leads to variable magnetization transfer (MT) effects. We demonstrate the hybrid design approach for quantitative imaging where both flip angle and B 1 rms $$ {B}_1^{\mathrm{rms}} $$ are important.

Theory and methods

A dual cost function optimization is performed containing the normalized mean squared errors of the flip angle and B 1 rms $$ {B}_1^{\mathrm{rms}} $$ distributions weighted by a

SUBMITTER: Leitao D 

PROVIDER: S-EPMC11680742 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature