Propagation of error from parameter constraints in quantitative MRI: Example application of multiple spin echo T₂ mapping.

ABSTRACT:

Purpose

Quantitative MRI may require correcting for nuisance parameters which can or must be constrained to independently measured or assumed values. The noise and/or bias in these constraints propagate to fitted parameters. For example, the case of refocusing pulse flip angle constraint in multiple spin echo T₂ mapping is explored.

Methods

An analytical expression for the mean-squared error of a parameter of interest was derived as a function of the accuracy and precision of an independent estimate of a nuisance parameter. The expression was validated by simulations and then used to evaluate the effects of flip angle (θ) constraint on the accuracy and precision of T⁁2 for a variety of multi-echo T₂ mapping protocols.

Results

Constraining θ impro

SUBMITTER: Lankford CL 

PROVIDER: S-EPMC5650597 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature