2007/05/31 by Vadim S Zotev, V. S. Zotev, Andrei N Matlashov +9 · 2 citations
Medicine · Physics and Astronomy · #Advanced MRI Techniques and Applications #Atomic and Subatomic Physics Research #NMR spectroscopy and applications #physics.ins-det #physics.med-ph
paper · pdf · doi:10.1088/0953-2048/20/11/s13
published as Superconductor Science and Technology 20, S367 (2007) · To appear in Proceedings of 11th International Superconductive Electronics Conference (ISEC 2007); 8 pages, 11 figures
arxiv created 2007/07/30 · openalex publication_date 2007/10/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
Magnetic resonance imaging at ultralow fields (ULF MRI) is a promising new imaging method that uses SQUID sensors to measure the spatially encoded precession of pre-polarized nuclear spin populations at a microtesla-range measurement field. In this work, a seven-channel SQUID system designed for simultaneous 3D ULF MRI and magnetoencephalography (MEG) is described. The system includes seven second-order SQUID gradiometers characterized by magnetic field resolutions of 1.2–2.8 fT Hz −1/2 . It is also equipped with five sets of coils for 3D Fourier imaging with pre-polarization. Essential technical details of the design are discussed. The system's ULF MRI performance is demonstrated by multi-channel 3D images of a preserved sheep brain acquired at 46 µT measurement field with pre-polarization at 40 mT. The imaging resolution is 2.5 mm × 2.5 mm × 5 mm. The ULF MRI images are compared to images of the same brain acquired using conventional high-field MRI. Different ways to improve imaging SNR are discussed.