Fast and accurate compensation of signal offset for T2 mapping
Language English Country Germany Media print-electronic
Document type Journal Article
Grant support
LM2015062
Ministerstvo Školství, Mládeže a Tělovýchovy
PubMed
30730022
DOI
10.1007/s10334-019-00737-3
PII: 10.1007/s10334-019-00737-3
Knihovny.cz E-resources
- Keywords
- Algorithms, Least-squares analysis, Software,
- MeSH
- Algorithms MeSH
- Time Factors MeSH
- Phantoms, Imaging MeSH
- Image Interpretation, Computer-Assisted methods MeSH
- Humans MeSH
- Magnetic Resonance Imaging * MeSH
- Least-Squares Analysis MeSH
- Prostatic Neoplasms diagnostic imaging MeSH
- Image Processing, Computer-Assisted methods MeSH
- Signal-To-Noise Ratio MeSH
- Probability MeSH
- Regression Analysis MeSH
- Reproducibility of Results MeSH
- Software MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
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.
Department of Urology Medical School Masaryk University Jihlavská 20 62500 Brno Czech Republic
Department of Urology University Hospital Brno Jihlavská 20 62500 Brno Czech Republic
See more in 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
