Optimization of a Phased-Array Coil for High-Resolution MR of the Carotid Arteries

utilization of surface coils is essential. The carotid arteries are situated superficial at a depth of y = 3-4 cm. To ensure adequate longitudinal coverage, including the bifurcation, they should be imaged over a length of about ∆zK = 8 cm. The penetration depth of a surface coil is approximately restricted to its smallest geometrical dimension. To enhance the SNR while maintaining anatomical coverage, phased-arrays are used. Phased-arrays consist of several individual coils, which are arranged with an optimized overlap. Phased-arrays achieve a higher SNR than single coils with the same surface coverage. This is not the first application of a phased-array coil for high-resolution MR of the carotid arteries. Hayes et al. [1] developed an array consisting of two square elements with overall dimensions of ∆x x ∆z = 10.8 cm x 6.4 cm. The goal of the present work is the optimization of the geometry of the elements to further enhance the SNR, while maintaining an anatomical coverage (5 cm x 8 cm) which avoids the necessity for frequent repositioning of the coil in a clinical situation. METHODS