title: Three-dimensional inversion recovery manganese-enhanced MRI of mouse brain using super-resolution reconstruction to visualize nuclei involved in higher brain function.
abstract: The visualization of activity in mouse brain using inversion recovery spin echo (IR-SE) manganese-enhanced MRI (MEMRI) provides unique contrast, but suffers from poor resolution in the slice-encoding direction. Super-resolution reconstruction (SRR) is a resolution-enhancing post-processing technique in which multiple low-resolution slice stacks are combined into a single volume of high isotropic resolution using computational methods. In this study, we investigated, first, whether SRR can improve the three-dimensional resolution of IR-SE MEMRI in the slice selection direction, whilst maintaining or improving the contrast-to-noise ratio of the two-dimensional slice stacks. Second, the contrast-to-noise ratio of SRR IR-SE MEMRI was compared with a conventional three-dimensional gradient echo (GE) acquisition. Quantitative experiments were performed on a phantom containing compartments of various manganese concentrations. The results showed that, with comparable scan times, the signal-to-noise ratio of three-dimensional GE acquisition is higher than that of SRR IR-SE MEMRI. However, the contrast-to-noise ratio between different compartments can be superior with SRR IR-SE MEMRI, depending on the chosen inversion time. In vivo experiments were performed in mice receiving manganese using an implanted osmotic pump. The results showed that SRR works well as a resolution-enhancing technique in IR-SE MEMRI experiments. In addition, the SRR image also shows a number of brain structures that are more clearly discernible from the surrounding tissues than in three-dimensional GE acquisition, including a number of nuclei with specific higher brain functions, such as memory, stress, anxiety and reward behavior.
authors.affiliation: C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Dana S
authors.initials: DS
authors.lastname: Poole
authors.forename: Esben
authors.initials: E
authors.lastname: Plenge
authors.forename: Dirk H J
authors.initials: DH
authors.lastname: Poot
authors.forename: Egbert A J F
authors.initials: EA
authors.lastname: Lakke
authors.forename: Wiro J
authors.initials: WJ
authors.lastname: Niessen
authors.forename: Erik
authors.initials: E
authors.lastname: Meijering
authors.forename: Louise
authors.initials: L
authors.lastname: van der Weerd
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008345:Manganese; D051379:Mice; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio
chemical_list: D008345:Manganese
keywords: activation; brain nuclei; manganese-enhanced MRI; mouse brain; super-resolution reconstruction; three-dimensional inversion recovery