Development and Characterization of a Transceiver Solenoid RF Coil for MRI Acquisition of Ex Situ Brain Samples at 7 Teslas

This paper describes the development and characterization of a solenoid radiofrequency (RF) coil specifically designed for MRI acquisition of ex situ brain samples at 7 teslas. The coil was designed to maximize the filling factor of small brain samples, such as hippocampus and brainstem, providing optimum signal-to-noise ratio (SNR) when compared to a 32-channel volume head coil available. SNR measurements comparing the performance between the constructed solenoid and the available head coil have shown a gain of 4.8 times. As expected, field homogeneity achieved by the solenoid was found to be considerably worse when compared to the volume head coil. Nevertheless, the available region with high homogeneity provided by the solenoid showed to be enough to cover the whole sample and generate images free of RF inhomogeneity artifacts. The solenoid coil allowed the acquisition of high spatial resolution images of ex situ brainstem samples, making possible the discrimination between gray-white matters in the brainstem anatomy.