title: Mitigation of B1(+) inhomogeneity on single-channel transmit systems with TIAMO.
abstract: In magnetic resonance imaging, there has been a constant drive to higher static magnetic field strengths (B0) to achieve a higher signal-to-noise ratio and new or enhanced contrasts. In today's high-field systems, severe problems regarding the homogeneity of the transmission field are encountered. Recently, an acquisition scheme called Time-Interleaved Acquisition of Modes has been proposed to tackle the inhomogeneity problems in high-field magnetic resonance imaging. The basic premise is to excite two (or more) different B1(+) modes using static radiofrequency shimming in an interleaved acquisition, where the complementary radiofrequency patterns of the two modes can be exploited to improve overall signal homogeneity. In its usual implementation, a multichannel transmit system is required. In this work, the goal is to present a simple and inexpensive hardware setup which makes it possible to use time-interleaved acquisition of modes on any single-channel transmit system while making use of the vendor-provided single-channel radiofrequency safety system. To demonstrate the efficacy of this setup, spin echo images from the pelvis are acquired at 7 T exhibiting no complete signal dropouts.
authors.affiliation: Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Germany. Stephan.Orzada@uni-duisburg-essen.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Orzada
authors.forename: Sören
authors.initials: S
authors.lastname: Johst
authors.forename: Stefan
authors.initials: S
authors.lastname: Maderwald
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Bitz
authors.forename: Klaus
authors.initials: K
authors.lastname: Solbach
authors.forename: Mark E
authors.initials: ME
authors.lastname: Ladd
mesh_terms: D016477:Artifacts; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D010388:Pelvis / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers