Patent ID: 7683623

Claim:
A radio frequency coil for magnetic resonance imaging or spectroscopy, the coil comprising: a plurality of generally parallel conductive members surrounding a region of interest; one or more end members disposed generally transverse to the plurality of parallel conductive members; a generally cylindrical radio frequency shield surrounding the plurality of generally parallel conductive members; and switchable circuitry selectably including TEM switches selectively connecting the conductive members with the radio frequency shield, the switchable circuitry having (i) a first switched configuration having the TEM switches open in which the conductive members are operatively connected with the one or more end members, and (ii) a second switched configuration having the TEM switches closed in which the conductive members are operatively connected with the radio frequency shield, the radio frequency coil operating in a birdcage resonance mode in the first switched configuration and operating in a TEM resonance mode in the second switched configuration, the switchable circuitry further selected from a group consisting of: (i) in the second switched configuration the closed TEM switches and the radio frequency shield cooperatively define electrical bypasses that electrically bypass the one or more end members, and (ii) the switchable circuitry further includes birdcage switches selectively connecting the conductive members with the one or more end members, the first switched configuration having the birdcage switches closed and the second switched configuration having the birdcage switches open.