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Fast and robust 3D T 1 mapping using spiral encoding and steady RF excitation at 7 T: application to cardiac manganese enhanced MRI (MEMRI) in mice
Author(s) -
Castets Charles R.,
Ribot Emeline J.,
Lefrançois William,
Trotier Aurélien J.,
Thiaudière Eric,
Franconi JeanMichel,
Miraux Sylvain
Publication year - 2015
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.3327
Subject(s) - spiral (railway) , temporal resolution , materials science , excitation , contrast (vision) , pulse (music) , in vivo , biomedical engineering , nuclear magnetic resonance , image resolution , signal (programming language) , pulse sequence , physics , computer science , chemistry , mathematics , artificial intelligence , voltage , medicine , optics , biology , mathematical analysis , microbiology and biotechnology , quantum mechanics , programming language
Mapping longitudinal relaxation times in 3D is a promising quantitative and non‐invasive imaging tool to assess cardiac remodeling. Few methods are proposed in the literature allowing us to perform 3D T 1 mapping. These methods often require long scan times and use a low number of 3D images to calculate T 1 . In this project, a fast 3D T 1 mapping method using a stack‐of‐spirals sampling scheme and regular RF pulse excitation at 7 T is presented. This sequence, combined with a newly developed fitting procedure, allowed us to quantify T 1 of the whole mouse heart with a high spatial resolution of 208 × 208 × 315 µm 3 in 10–12 min acquisition time. The sensitivity of this method for measuring T 1 variations was demonstrated on mouse hearts after several injections of manganese chloride (doses from 25 to 150 µmol kg −1 ). T 1 values were measured in vivo in both pre‐ and post‐contrast experiments. This protocol was also validated on ischemic mice to demonstrate its efficiency to visualize tissue damage induced by a myocardial infarction. This study showed that combining spiral gradient shape and steady RF excitation enabled fast and robust 3D T 1 mapping of the entire heart with a high spatial resolution. Copyright © 2015 John Wiley & Sons, Ltd.