The ultimate signal-to-noise ratio in realistic body models.

ABSTRACT:

Purpose

We compute the ultimate signal-to-noise ratio (uSNR) and G-factor (uGF) in a realistic head model from 0.5 to 21 Tesla.

Methods

We excite the head model and a uniform sphere with a large number of electric and magnetic dipoles placed at 3 cm from the object. The resulting electromagnetic fields are computed using an ultrafast volume integral solver, which are used as basis functions for the uSNR and uGF computations.

Results

Our generalized uSNR calculation shows good convergence in the sphere and the head and is in close agreement with the dyadic Green's function approach in the uniform sphere. In both models, the uSNR versus B₀ trend was linear at shallow depths and supralinear at deeper locations. At equivalent positions, the rate of increase of

SUBMITTER: Guerin B 

PROVIDER: S-EPMC5532082 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature