Adiabatic J Cross Polarization for Localized Direct and Proton-Detected 13C Spectroscopy

✍ Scribed by H. Kostler; R. Kimmich

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 501 KB
• Volume: 102
• Category: Article
• ISSN: 1064-1866
• DOI: 10.1006/jmrb.1993.1097

✦ Synopsis

This work predominantly refers to in vivo spectroscopy. The objective is to record volume-selectively ({ }^{13} \mathrm{C}) signals by the aid of a new, simple, and robust localization technique. (J) cross polarization (or coherent rotating-frame polarization transfer) between coupled ({ }^{1} \mathrm{H}) and ({ }^{13} \mathrm{C}) nuclei is employed in the adiabatic level-crossing version. In the presence of a magnetic field gradient, the passage of the Hartmann/Hahn-matched energy splitting depends on position so that the polarization-transfer process is slice-selective. The signal enhancement of rare (\mathrm{X}) nuclei thus is performed slice-selectively. Test experiments demonstrating the efficiency of adiabatic (J) cross-polarization-localized spectroscopy (AJCP-LOSY) are reported. The cyclic application of the AJCP-LOSY procedure permits the indirect slice-selective detection of coupled X nuclei (adiabatic CYCLCROP-LOSY). Signals from coupled nuclei are thus observed while other signals are suppressed. The technique can be extended to volume-selective excitations of ({ }^{13} \mathrm{C}) or, preferably, of ({ }^{1} \mathrm{H}) nuclei coupled to ({ }^{13} \mathrm{C}). The latter proposal implies heteronuclear editing analogous to the CYCLPOT-VOSING methods for laboratory-frame polarization transfer previously suggested. 1993 Academic Press, Inc.