Slotted cage resonator for high-field magnetic resonance imaging of rodents

• Published in: Journal of physics. D, Applied physics Applied physics, 2011-04, Vol.44 (15), p.155503
• Main Authors: Marrufo, O, Vasquez, F, Solis, S E, Rodriguez, A O
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Radiodiagnosis. Nmr imagery. Nmr spectrometry
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/44/15/155503

A variation of the high-frequency cavity resonator coil was experimentally developed according to the theoretical frame proposed by Mansfield in 1990. Circular slots were used instead of cavities to form the coil endplates and it was called the slotted cage resonator coil. The theoretical principles were validated via a coil equivalent circuit and also experimentally with a coil prototype. The radio frequency magnetic field, B 1, produced by several coil configurations was numerically simulated using the finite-element approach to investigate their performances. A transceiver coil, 8 cm long and 7.6 cm in diameter, and composed of 4 circular slots with a 15 mm diameter on both endplates, was built to operate at 300 MHz and quadrature driven. Experimental results obtained with the slotted cage resonator coil were presented and showed very good agreement with the theoretical expectations for the resonant frequency as a function of the coil dimensions and slots. A standard birdcage coil was also built for performance comparison purposes. Phantom images were then acquired to compute the signal-to-noise ratio of both coils showing an important improvement of the slotted cage coil over the birdcage coil. The whole-body images of the mouse were also obtained showing high-quality images. Volume resonator coils can be reliably built following the physical principles of the cavity resonator design for high-field magnetic resonance imaging applications of rodents.