  This document reports an unconventional and rapidly developing approach to
magnetic resonance imaging (MRI) using intermolecular multiple-quantum
coherences (iMQCs). Rat brain images are acquired using iMQCs. We detect iMQCs
between spins that are 10 {\mu}m to 500 {\mu}m apart. The interaction between
spins is dependent on different directions. We can choose the directions on
physical Z, Y and X axis by choosing correlation gradients along those
directions. As an important application, iMQCs can be used for anisotropy
mapping. In the rat brains, we investigate tissue microstructure. We simulated
images expected from rat brains without microstructure. We compare those with
experimental results to prove that the dipolar field from the overall shape
only has small contributions to the experimental iMQC signal. Because of the
underlying low signal to noise ratio (SNR) in iMQCs, this anisotropy mapping
method still has comparatively large potentials to grow. The ultimate goal of
my project is to develop creative and effective methods of tissue
microstructure anisotropy mapping. Recently we found that combining phase data
of iMQCs images with phase data of modified-crazed images is very promising to
construct microstructure maps. Some information and initial results are shown
in this document.
