A transmit-only/receive-only (TORO) RF system for high-field MRI/MRS applications.
The design and operation of a detunable shielded hybrid birdcage RF head coil optimized for human brain imaging at 170 MHz is presented. A high duty-cycle and rapid-switching decoupling scheme that allows uniform RF transmission with the head coil and reception with a surface coil within the volume of the head coil is also demonstrated. In addition, the circumscribing hybrid coil can be biased to operate as a conventional transmit/receive head coil. Our RF design allows the use of higher sensitivity surface coils or phased-array coils at very high magnetic fields where body RF resonators are not currently available or whose use is precluded by specific-absorption ratio restrictions. The design also allows the use of receive-only coils within head gradient inserts, which normally do not allow transmission with an RF body resonator at any field strength.
Barberi
E A
EA
Imaging Research Laboratories, John P. Robarts Research Institute, London, Ontario, Canada.
Gati
J S
JS
Rutt
B K
BK
Menon
R S
RS
D004867:Equipment Design / Q000706:statistics & numerical data; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000706:statistics & numerical data; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000706:statistics & numerical data; D019047:Phantoms, Imaging / Q000706:statistics & numerical data; D011846:Radio Waves; D012680:Sensitivity and Specificity