Hyperpolarized carbon-13 magnetic resonance spectroscopy is a novel and powerful tool for exploring the metabolic state of tissue, but a number of technological problems still limit this technology and need innovative solutions. In particular, the low molar concentration of derivate metabolites give rise to low signal-to-noise ratio (SNR), which makes the design and development of dedicated RF coils a task of fundamental importance. In this article, the authors describe the simulation and the design of a dedicated surface coil for cardiac metabolism assessment in pig models.Methods:
A SNR model for a circular loop is presented and applied to the design of acoil which guarantees the desired field-of-view and provides high SNR with a good penetration in deep sample regions. The coilresistance was calculated from Ohm’s law and the magnetic field pattern was calculated using Biot–Savart law, while the sample induced resistance was calculated using a numerical finite-difference time-domain algorithm. Successively, a prototype of the coil was built and tested on the workbench and by acquisition of MR data.Results:
The comparison of SNR-vs-depth profiles between the theoretical SNR model and the experimental SNR extracted from the phantom chemical shift image (CSI) showed the accuracy of the authors’ model. Moreover, the authors demonstrated the use of the coil for the acquisition of a CSI of a hyperpolarized pyruvate phantom.Conclusions:
The results demonstrated the design trade-offs to successfully design a dedicated coil for cardiacimaging in the pig with hyperpolarized by developing a SNR model which allows the prediction of the coil performance. This approach can be employed for deriving SNR formulations for coil with more complex geometries.
II. MATERIALS AND METHODS
II.A. SNR evaluation
II.B. Coil inductance calculation
II.C. Coilmagnetic field calculation
II.D. Coilresistance estimation
II.E. Sample induced resistance estimation
II.F. Coil building and workbench test
II.G. CoilMR test
III.A. Coil simulation
III.B. Coil workbench test
III.C. CoilMR test
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