We have measured the decay of NMR multiple quantum coherence intensities both under the internal dipolar Hamiltonian as well as when this interaction is effectively averaged to zero, in the cubic calcium fluoride ͑CaF 2 ͒ spin system and the pseudo-one-dimensional system of fluoroapatite. In calcium fluoride the decay rates depend both on the number of… (More)
This study presents the first demonstration of the MR signal decay due to diffusion in the internal field (DDIF) for in vivo knee trabecular bone imaging. DDIF contrast was compared with high resolution FLASH, T 1 , and T 2 * mapping in healthy volunteers. DDIF maps showed spatial variation, superimposed on a T 1 background, reflecting trabecular structure.… (More)
Solid state Nuclear Magnetic Resonance (NMR) allows us to explore a large coherent spin system and provides an ideal test-bed for studying strongly interacting multiple-spin system in a large Hilbert space. In this thesis, we experimentally investigate the spin dynamics in a rigid lattice of dipolarly coupled nuclear spins using multiple quantum NMR… (More)
A variable repetition-delay (TR) spin echo sequence with repeated refocusing pulses, i.e., a variable TR turbo-spin echo (TSE), provides an attractive means of acquiring an accurate T1 map information that is free from gradient echo based artifacts such as magnetic field inhomogeneities particularly for ultra-high field (at 7T and above) preclinical… (More)
High field magnetic resonance imaging (MRI)-based delineation of the substantia nigra (SN) and visualization of its inner cellular organization are promising methods for the evaluation of morphological changes associated with neurodegenerative diseases; however, corresponding MR contrasts must be matched and validated with quantitative histological… (More)
With the applications of magnetic resonance imaging (MRI) at higher magnetic fields increasing, there is demand for MRI contrast agents with improved relaxivity at higher magnetic fields. Macromolecule-based contrast agents, such as protein-based ones, are known to yield significantly higher r1 relaxivity at low fields, but tend to lose this merit when used… (More)
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