Intramolecular zero-quantum-coherence 2D NMR spectroscopy of lipids in the human breast at 7 T

Intramolecular zero-quantum-coherences (ZQCs) are intrinsically insensitive toward magnetic field inhomogeneity. This fact is used to quantify and characterize lipid signals in the human breast at 7 T despite the presence of severe magnetic field inhomogeneity caused by water-lipid susceptibility boundaries.

A novel 3D localized 2D ZQC method is presented. The combination of cardiac/respiratory triggering and post-acquisition navigator echo correction provides high-quality 2D NMR spectra in vivo.

The lipid profile of the human breast could be quantified by 2D ZQC NMR in 100% of the subjects despite a wide range of magnetic field homogeneity. With conventional 1D (1)H MRS, the magnetic field homogeneity was only adequate in 60% of the subjects. The results from 2D ZQC NMR and 1D NMR are in good correspondence, both in vitro and in vivo.

It has been demonstrated that high quality and quantitative 2D ZQC NMR spectra can be acquired from human breast tissue at 7 T. While the simplicity and sensitivity of 1D MRS are preferable when the magnetic field homogeneity is adequate, the 2D ZQC method provides a viable alternative in cases where this requirement cannot be met.