title: Signal-to-noise ratio of a mouse brain (13) C CryoProbe™ system in comparison with room temperature coils: spectroscopic phantom and in vivo results.
abstract: MRI and MRS in small rodents demand very high sensitivity. Cryogenic transmit/receive radiofrequency probes (CryoProbes) designed for (1) H MRI of mouse brain provide an attractive option for increasing the performance of small-animal MR systems. As the Larmor frequency of (13) C nuclei is four times lower than that for (1) H nuclei, an even larger sensitivity improvement is expected for (13) C applications. The aim of this work was to evaluate the performance of a prototype (13) C CryoProbe™ for mouse brain MRS. To investigate the possible gain of the (13) C CryoProbe™, we acquired localized single-voxel (13) C spectra and chemical shift images of a dimethyl sulfoxide phantom with the CryoProbe™, as well as with two room temperature resonators. The cryogenically cooled resonator achieved approximately four-fold higher signal-to-noise ratio in phantom tests when compared with the best-performing room temperature coil. In addition, we present localized (13) C spectra of mouse brain obtained with the CryoProbe™, as well as with one of the room temperature coils, demonstrating the performance in vivo. In summary, the cryogenic cooling technique significantly enhances the (13) C signal sensitivity at 9.4 T and enables the investigation of metabolism within mouse brain.
authors.affiliation: Research Group Translational Imaging, Central Institute of Mental Health, Medical Faculty, Mannheim/Heidelberg University, Mannheim, Germany; Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty, Mannheim/Heidelberg University, Mannheim, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Sack
authors.forename: F
authors.initials: F
authors.lastname: Wetterling
authors.forename: A
authors.initials: A
authors.lastname: Sartorius
authors.forename: G
authors.initials: G
authors.lastname: Ende
authors.forename: W
authors.initials: W
authors.lastname: Weber-Fahr
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002247:Carbon Isotopes; D005947:Glucose / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio; D013696:Temperature
chemical_list: D002247:Carbon Isotopes; D005947:Glucose
keywords: 13C spectroscopy; CryoProbe™; MRS; SNR comparison; cryogenic coil; mouse