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Validation and optimization of adiabatic T 1ρ and T 2ρ for quantitative imaging of articular cartilage at 3 T
Author(s) -
Casula Victor,
Autio Joonas,
Nissi Mikko J.,
Auerbach Edward J.,
Ellermann Jutta,
Lammentausta Eveliina,
Nieminen Miika T.
Publication year - 2017
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.26183
Subject(s) - reproducibility , cartilage , agarose , imaging phantom , in vivo , magnetic resonance imaging , t2 relaxation , biomedical engineering , nuclear magnetic resonance , relaxation (psychology) , materials science , nuclear medicine , chemistry , medicine , anatomy , radiology , physics , biology , chromatography , microbiology and biotechnology
Purpose The aim of the present work was to validate and optimize adiabatic T 1ρ and T 2ρ mapping for in vivo measurements of articular cartilage at 3 Tesla (T). Methods Phantom and in vivo experiments were systematically performed on a 3T clinical system to evaluate the sequences using hyperbolic secant HS1 and HS4 pulses. R 1ρ and R 2ρ relaxation rates were studied as a function of agarose and chondroitin sulfate concentration and pulse duration. Optimal in vivo protocol was determined by imaging the articular cartilage of two volunteers and varying the sequence parameters, and successively applied in eight additional subjects. Reproducibility was assessed in phantoms and in vivo. Results Relaxation rates depended on agarose and chondroitin sulfate concentration. The sequences were able to generate relaxation time maps with pulse lengths of 8 and 6 ms for HS1 and HS4, respectively. In vivo findings were in good agreement with the phantoms. The implemented adiabatic T 1ρ and T 2ρ sequences demonstrated regional variation in relaxation time maps of femorotibial cartilage. Reproducibility in phantoms and in vivo was good to excellent for both adiabatic T 1ρ and T 2ρ . Conclusions The findings indicate that sequences are suitable for quantitative in vivo assessment of articular cartilage at 3 T. Magn Reson Med 77:1265–1275, 2017. © 2016 International Society for Magnetic Resonance in Medicine