Quadrature birdcage coil with distributed capacitors for 7.0 T magnetic resonance data acquisition of small animals

High static magnetic field magnetic resonance imaging (MRI) is commonly used for preclinical studies in rodents. In this context, minimization of coil losses is mandatory to scan samples that are small compared to the radiofrequency wavelength in the medium. In this study we construct a radiofrequency (RF) birdcage probe with distributed capacitors, operating in quadrature, tailored for 7.0T 1H MRI of small animals. The design eliminates the need for extra electrical components on the probe structure and affords a high SNR, a uniform B1+ field (homogeneity of 93% in the axial plain of the phantom) and a coil sensitivity of 9.8 μT/W. Feasibility experiments of mouse imaging are conducted and the competitive capability of a 7.0 T human system equipped with the proposed coil is demonstrated in both body and brain preclinical imaging.