Sensitivity-enhanced 13C MR spectroscopy of the human brain at 3 Tesla

✍ Scribed by D.W.J. Klomp; W.K.J. Renema; M. van der Graaf; B.E. de Galan; A.P.M. Kentgens; A. Heerschap

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 593 KB
• Volume: 55
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.20745

✦ Synopsis

Abstract

A new coil design for sensitivity‐enhanced ^13^C MR spectroscopy (MRS) of the human brain is presented. The design includes a quadrature transmit/receive head coil optimized for ^13^C MR sensitivity. Loss‐less blocking circuits inside the coil conductors allow this coil to be used inside a homogeneous circularly polarized ^1^H B~1~ field for ^1^H decoupled ^13^C MRS. A quadrature ^1^H birdcage coil optimized for minimal local RF heating makes broadband ^1^H decoupling in the entire human brain possible at 3 Tesla while remaining well within international safety guidelines for RF absorption. Apart from a substantial increase in sensitivity compared to conventional small linear coils, the quadrature ^13^C coil combined with the quadrature ^1^H birdcage coil allows efficient cross polarization (CP) in the brain, resulting in an additional 3.5‐fold sensitivity improvement compared to direct ^13^C measurements without nuclear Overhauser enhancement (NOE) or polarization transfer. Combined with the gain in power efficiency, this setup allows broadband ^1^H to ^13^C CP over large areas of the brain. Clear ^13^C resonances from glutamate (Glu), glutamine (Gln), aspartate (Asp), lactate (Lac), and γ‐aminobutyrate (GABA) carbon spins in the human brain demonstrate the quality of ^13^C MR spectra obtained in vivo with this coil setup. Magn Reson Med, 2006. © 2005 Wiley‐Liss, Inc.