Design of a superconducting volume coil for magnetic resonance microscopy of the mouse brain.
We present the design process of a superconducting volume coil for magnetic resonance microscopy of the mouse brain at 9.4T. The yttrium barium copper oxide coil has been designed through an iterative process of three-dimensional finite-element simulations and validation against room temperature copper coils. Compared to previous designs, the Helmholtz pair provides substantially higher B(1) homogeneity over an extended volume of interest sufficiently large to image biologically relevant specimens. A custom-built cryogenic cooling system maintains the superconducting probe at 60+/-0.1K. Specimen loading and probe retuning can be carried out interactively with the coil at operating temperature, enabling much higher through-put. The operation of the probe is a routine, consistent procedure. Signal-to-noise ratio in a mouse brain increased by a factor ranging from 1.1 to 2.9 as compared to a room-temperature solenoid coil optimized for mouse brain microscopy. We demonstrate images encoded at 10x10x20mum for an entire mouse brain specimen with signal-to-noise ratio of 18 and a total acquisition time of 16.5h, revealing neuroanatomy unseen at lower resolution. Phantom measurements show an effective spatial resolution better than 20mum.
Nouls
John C
JC
Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, NC 27710, USA.
Izenson
Michael G
MG
Greeley
Harold P
HP
Johnson
G Allan
GA
D000818:Animals; D001921:Brain / Q000166:cytology*; D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000662:veterinary; D008280:Magnetics / Q000295:instrumentation*; D051379:Mice; D008853:Microscopy / Q000295:instrumentation* / Q000662:veterinary*; D014159:Transducers / Q000662:veterinary