Fast and accurate compensation of signal offset for T2 mapping

. 2019 Aug ; 32 (4) : 423-436. [epub] 20190207

Jazyk angličtina Země Německo Médium print-electronic

Typ dokumentu časopisecké články

Perzistentní odkaz   https://www.medvik.cz/link/pmid30730022

Grantová podpora
LM2015062 Ministerstvo Školství, Mládeže a Tělovýchovy

Odkazy

PubMed 30730022
DOI 10.1007/s10334-019-00737-3
PII: 10.1007/s10334-019-00737-3
Knihovny.cz E-zdroje

OBJECTIVE: T2 maps are more vendor independent than other MRI protocols. Multi-echo spin-echo signal decays to a non-zero offset due to imperfect refocusing pulses and Rician noise, causing T2 overestimation by the vendor's 2-parameter algorithm. The accuracy of the T2 estimate is improved, if the non-zero offset is estimated as a third parameter. Three-parameter Levenberg-Marquardt (LM) T2 estimation takes several minutes to calculate, and it is sensitive to initial values. We aimed for a 3-parameter fitting algorithm that was comparably accurate, yet substantially faster. METHODS: Our approach gains speed by converting the 3-parameter minimisation problem into an empirically unimodal univariate problem, which is quickly minimised using the golden section line search (GS). RESULTS: To enable comparison, we propose a novel noise-masking algorithm. For clinical data, the agreement between the GS and the LM fit is excellent, yet the GS algorithm is two orders of magnitude faster. For synthetic data, the accuracy of the GS algorithm is on par with that of the LM fit, and the GS algorithm is significantly faster. The GS algorithm requires no parametrisation or initialisation by the user. DISCUSSION: The new GS T2 mapping algorithm offers a fast and much more accurate off-the-shelf replacement for the inaccurate 2-parameter fit in the vendor's software.

Zobrazit více v PubMed

J Magn Reson Imaging. 2008 Nov;28(5):1166-72 PubMed

Magn Reson Med. 2012 Jun;67(6):1803-14 PubMed

MAGMA. 2014 Dec;27(6):567-77 PubMed

Magn Reson Med. 2015 Feb;73(2):843-50 PubMed

J Magn Reson Imaging. 2015 Feb;41(2):266-95 PubMed

Magn Reson Med. 2015 Jul;74(1):93-105 PubMed

Diagn Interv Imaging. 2015 Apr;96(4):365-72 PubMed

Magn Reson Med. 2016 Jan;75(1):390-402 PubMed

PLoS One. 2015 Dec 17;10(12):e0145255 PubMed

Magn Reson Med. 2017 Jan;77(1):385-397 PubMed

MAGMA. 2016 Oct;29(5):777-88 PubMed

Magn Reson Imaging. 2017 Jan;35:69-80 PubMed

J Magn Reson Imaging. 2018 Nov;48(5):1432-1440 PubMed

Magn Reson Med. 1994 Jun;31(6):673-7 PubMed

Magn Reson Med. 1995 Dec;34(6):910-4 PubMed

Magn Reson Imaging. 1997;15(10):1177-86 PubMed

Najít záznam

Citační ukazatele

Nahrávání dat ...

Možnosti archivace

Nahrávání dat ...