A four-channel hole-slotted phased array at 7 Tesla

In recent years, the phased array coil technology has found more and more its way in applications at high field small animal systems. However, these coil arrays are usually based on simple loops and are mostly used in rat imaging studies only. Mouse imaging studies are limited to the use of linear arrays or volume resonators. Recently, a novel surface coil design based on the hole-slot magnetron's geometry was introduced to MRI. The hole-slot magnetron is a vacuum tube which operates e.g. as a high frequency oscillator in radar applications. It has been shown that the magnetron surface coil allows for a deeper RF penetration than a conventional coil both at 1.5 and 4 Tesla. The objective of this work was to find an optimal loop coil based on the hole-slot magnetron geometry in order to build a volume phased array for cardiac imaging with improved SNR on the centre of the sample. To achieve this goal, different magnetron loops were simulated and evaluated towards their performance. Based on these results the best performing hole-slot magnetron geometries were built and compared. In addition, the magnetron loop (referred as hole-slotted coil) with the best sensitivity was compared with conventional simple loop geometries. Furthermore, a four channel hole-slotted phased array based on the magnetron's design theory was built, evaluated and compared with a conventional four channel array. The four channel hole-slotted array shows improved RF penetration depth over the four channel array with simple loop geometry