Alexander Ruh1, Philipp Emerich1, Dmitry S. Novikov2, Valerij G. Kiselev1
1Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany; 2Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States
NMR spectroscopy is commonly used to detect populations of nuclei in different chemical environments. We demonstrate for the first time that the lineshape of chemically homogeneous nuclei carries information about microscopic spatial variations of NMR parameters. In particular, the water lineshape is sensitive to the degree of structural ordering of magnetic susceptibility in microscopically heterogeneous samples, such as tissues with the susceptibility varying on a cellular scale. We explicitly focus on the lineshape features which distinguish an ordered (periodic) sample from a disordered one. Our results agree well with Monte Carlo simulations of transverse relaxation in synthetic three-dimensional media.