Proton-detected 13C imaging using cyclic J cross polarization.

A new method is proposed permitting two- or three-dimensional Fourier transform imaging of protons coupled to 13C nuclei. In this way the spatial distribution of a preselected 13C resonance line can be imaged indirectly. The initial excitation as well as the detection of the signal are performed in the proton radiofrequency channel so that the utmost sensitivity is achieved. The principle is cyclic J cross polarization (CYCLCROP) for heteronuclear editing combined with a standard imaging sequence. The sequence has been implemented on a 4.7 T tomography system and successfully tested with a phantom as well as with biological objects with 13C in natural abundance.