Optimal flip angles for in vivo liver 3D T₁ mapping and  B₁₊  mapping at 3T.

ABSTRACT:

Purpose

The spoiled gradient recalled echo (SPGR) sequence with variable flip angles (FAs) enables whole liver T1$$ {T}_1 $$ mapping at high spatial resolutions but is strongly affected by B1+$$ {B}_1^{+} $$ inhomogeneities. The aim of this work was to study how the precision of acquired T1$$ {T}_1 $$ maps is affected by the T1$$ {T}_1 $$ and B1+$$ {B}_1^{+} $$ ranges observed in the liver at 3T, as well as how noise propagates from the acquired signals into the resulting T1$$ {T}_1 $$ map.

Theory

The T1$$ {T}_1 $$ variance was estimated through the Fisher information matrix with a total noise variance including, for the first time, the B1+$$ {B}_1^{+} $$ map noise as well as contributions from the SPGR noise.

Methods

Simulations were used to find the optimal FAs for

SUBMITTER: Belsley G 

PROVIDER: S-EPMC10952198 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature