Optimization of spin-lock times in T_1ρ mapping of knee cartilage: Cramer-Rao bounds versus matched sampling-fitting.

ABSTRACT:

Purpose

To compare different optimization approaches for choosing the spin-lock times (TSLs), in spin-lattice relaxation time in the rotating frame (T_1ρ ) mapping.

Methods

Optimization criteria for TSLs based on Cramér-Rao lower bounds (CRLB) are compared with matched sampling-fitting (MSF) approaches for T_1ρ mapping on synthetic data, model phantoms, and knee cartilage. The MSF approaches are optimized using robust methods for noisy cost functions. The MSF approaches assume that optimal TSLs depend on the chosen fitting method. An iterative non-linear least squares (NLS) and artificial neural networks (ANN) are tested as two possible T_1ρ fitting methods for MSF approaches.

Results

All optimized criteria were better than non-optimized

SUBMITTER: Zibetti MVW 

PROVIDER: S-EPMC8822470 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature