Simulation Of Magnetic Resonance Imaging Based On Intermolecular Multiple-quantum Coherences

Recently the study of intermolecular multiple-quantum coherences (iMQC) is increasing hot in nuclear magnetic resonance (NMR) field. It is expected that iMQC will have a great application in magnetic resonance imaging (MRI). Although the signal of iMQC is lower in intensity than that of conventional MRI, it contains unique imaging parameters such as dipolar correlation distance. Therefore, iMQC-MRI may provide higher resolution and novel contrast mechanism.By using an algorithm based on non-linear Bloch equation, a series of iMQC-MRI of a three-dimensional sample were simulated systematically. Combining the iMQC and dipolar field treatments, contribution of primary parameters to iMQC-MRI contrast, as well as specific imaging information provided by iMQC, were discussed thoroughly. The main results are summarized as follows:First, we employed a fast, efficient numerical algorithm which switches back and forth between real and Fourier spaces to simulate distant dipolar field (DDF) and diffusion effects for heterogeneous three-dimensional structures. Simulated results show that the algorithm can correctly reflect the DDF effect and the resulting iMQC signals, providing a solid base for studying the unique image contrast mechanism of iMQC.Second, when suitable imaging pulse sequence and imaging parameters were selected, images with unique contrast were obtained without using contrast agents. Simulated results demonstrated that the iMQC images can help enhance contrast in MRI and contain...