title: Performance of external and internal coil configurations for prostate investigations at 7 T.
abstract: Three different coil configurations were evaluated through simulation and experimentally to determine safe operating limits and evaluate subject size-dependent performance for prostate imaging at 7 T. The coils included a transceiver endorectal coil (trERC), a 16-channel transceiver external surface array (trESA) and a trESA combined with a receive-only ERC (trESA+roERC). Although the transmit B(1) (B 1+) homogeneity was far superior for the trESA, the maximum achievable B 1+ is subject size dependent and limited by transmit chain losses and amplifier performance. For the trERC, limitations in transmit homogeneity greatly compromised image quality and limited coverage of the prostate. Despite these challenges, the high peak B 1+ close to the trERC and subject size-independent performance provides potential advantages especially for spectroscopic localization where high-bandwidth radiofrequency pulses are required. On the receive side, the combined trESA+roERC provided the highest signal-to-noise ratio and improved homogeneity over the trERC resulting in better visualization of the prostate and surrounding anatomy. In addition, the parallel imaging performance of the trESA+roERC holds strong promise for diffusion-weighted imaging and dynamic contrast-enhanced MRI.
authors.affiliation: Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA. gmetzger@umn.edu
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Metzger
authors.forename: Pierre-Francois
authors.initials: PF
authors.lastname: van de Moortele
authors.forename: Can
authors.initials: C
authors.lastname: Akgun
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Snyder
authors.forename: Steen
authors.initials: S
authors.lastname: Moeller
authors.forename: John
authors.initials: J
authors.lastname: Strupp
authors.forename: Peter
authors.initials: P
authors.lastname: Andersen
authors.forename: Devashish
authors.initials: D
authors.lastname: Shrivastava
authors.forename: Tommy
authors.initials: T
authors.lastname: Vaughan
authors.forename: Kamil
authors.initials: K
authors.lastname: Ugurbil
authors.forename: Gregor
authors.initials: G
authors.lastname: Adriany
mesh_terms: D000328:Adult; D004867:Equipment Design; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D011467:Prostate / Q000033:anatomy & histology*; D012007:Rectum