Numerical Solutions to the Bloch-McConnell Equations with Radio Frequency Irradiation Scheme for CEST MRI

Numerical Solutions to the Bloch-McConnell Equations with Radio Frequency Irradiation Scheme for CEST MRI

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Part of #Numerical Solutions to the Bloch-McConnell Equations with Radio Frequency Irradiation Scheme for CEST MRI# :

Publishing year : 2012

Conference : 20th Iranian Conference on Electrical Engineering

Number of pages : 6

Abstract: Chemical exchange saturation transfer (CEST) is a new mechanism of contrast generation in magnetic resonance imaging (MRI) which differentiates moleculebiomarkers through chemical shift. The CEST MRI contrast mechanism is complex and depends on radio frequency (RF) pulses used in experimental conditions. To find the optimal RF pulse, numerical solutions of Bloch-McConnell equations can be used. The purpose of this work is tocompare the effects of different RF pulses on the CEST phenomenon. First, a two-pool exchange model for CEST in MRI is used. Z-spectra and signal calculations for the twopoolmodel have been carried out for some RF pulses. Efficiency of both continuous and binomial RF pulses isinvestigated by calculating three parameters, namely: CEST image contrast, flip angle and specific absorption ratio (SAR). The contrast f CEST image is considered proportional to the amount of saturation. As a binomial RF pulse, WALTZ-16 * demonstrates a good efficiency, but generates some unwanted direct saturations. On the other hand, continuous RF pulses do not create any unwanted direct saturation, but have less efficiency