Slice-selective extended phase graphs in gradient-crushed, transient-state free precession sequences: An application to MR fingerprinting.

ABSTRACT:

Purpose

Slice-selective, gradient-crushed, transient-state sequences such as those used in MR fingerprinting (MRF) relaxometry are sensitive to slice profile effects. Whereas balanced steady-state free precession MRF profile effects have been studied, less attention has been given to gradient-crushed MRF forms. Extensions of the extended phase graph (EPG) formalism, called slice-selective EPG (ssEPG), are proposed that model slice profile effects.

Theory and methods

The hard-pulse approximation to slice-selective excitation in the spatial domain is reformulated in k-space. Excitation is modeled by standard EPG shift and transition operators. This ssEPG modeling is validated against Bloch simulations and phantom slice profile measurements. ssEPG relaxometry accuracy and varia

SUBMITTER: Ostenson J 

PROVIDER: S-EPMC8485742 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature