title: Fast and robust 3D T1 mapping using spiral encoding and steady RF excitation at 7 T: application to cardiac manganese enhanced MRI (MEMRI) in mice.
abstract: 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 T1 mapping. These methods often require long scan times and use a low number of 3D images to calculate T1 . In this project, a fast 3D T1 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 T1 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 T1 variations was demonstrated on mouse hearts after several injections of manganese chloride (doses from 25 to 150 µmol kg(-1) ). T1 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 T1 mapping of the entire heart with a high spatial resolution.
authors.affiliation: Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 CNRS/Universite de Bordeaux, Bordeaux Cedex, France.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Castets
authors.affiliation: Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 CNRS/Universite de Bordeaux, Bordeaux Cedex, France.
authors.forename: Emeline J
authors.initials: EJ
authors.lastname: Ribot
authors.affiliation: Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 CNRS/Universite de Bordeaux, Bordeaux Cedex, France.
authors.forename: William
authors.initials: W
authors.lastname: Lefrançois
authors.affiliation: Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 CNRS/Universite de Bordeaux, Bordeaux Cedex, France.
authors.forename: Aurélien J
authors.initials: AJ
authors.lastname: Trotier
authors.affiliation: Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 CNRS/Universite de Bordeaux, Bordeaux Cedex, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Thiaudière
authors.affiliation: Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 CNRS/Universite de Bordeaux, Bordeaux Cedex, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Franconi
authors.affiliation: Centre de Resonance Magnetique des Systemes Biologiques, UMR 5536 CNRS/Universite de Bordeaux, Bordeaux Cedex, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Miraux
mesh_terms: D000465:Algorithms; D000818:Animals; D003287:Contrast Media; D006352:Heart Ventricles / Q000473:pathology*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D015636:Magnesium Chloride; D051379:Mice; D008810:Mice, Inbred C57BL; D009203:Myocardial Infarction / Q000473:pathology*; D011829:Radiation Dosage; D011846:Radio Waves; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D015636:Magnesium Chloride
keywords: 3D T1 mapping; Look-Locker; MEMRI; mouse heart; spiral