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Two 16-element radio frequency (RF) transceiver antisymmetric coil arrays with two different implementation designs aiming for improved characteristics for static phase $B_{1}^{+}$ shimming and parallel receive were developed for human cardiac MRI at 7 T. Both cardiac arrays consist of a weakly curved lightweight housing fit to an average human thorax shape as an anterior array in combination with a flat posterior array. The first array (Design 1) comprised eight identical antisymmetric loops for both anterior and posterior sections. Based on initial testing and to improve parallel imaging capabilities and $B_{1}^{+}$ field homogeneity, the second array (Design 2) was composed of 12-loops for the anterior section and four antisymmetric loops of larger size for the posterior section. Electromagnetic-field (EMF) simulations were carried out for both antisymmetric arrays loaded with an elliptical-shaped thorax phantom and two human voxel models (Duke and Ella). Static phase $B_{1}^{+}$ shimming has been carried out within Duke and Ella models using two optimization cost functions aiming to maximize the transmit efficiency and weighted combination of both $B_{1}^{+}$ field homogeneity and efficiency. The hardware and imaging performance of the two developed antisymmetric cardiac arrays was validated through EMF simulations, benchtop measurements, and MR measurements in a thorax phantom. Both antisymmetric arrays were compared to two commercial 16-element transceiver arrays (a 1Tx/16Rx in single transmit mode and an 8Tx/16Rx in parallel transmit mode). MRI measurements were performed with Design 2 using a 70-kg fresh pig cadaver (10–15 min postmortem). Parallel imaging with an acceleration factor up to $R = 6$ was possible using Design 2 while maintaining a mean g-factor of 1.47 within the pig heart. $T_{2}^{\ast }$ -weighted images of the pig heart were acquired using up to $R = 5$ with a spatial resolution of $0.35 \times 0.35 \times 4$ mm3.

A dedicated, novel, multichannel transmit/receive (Tx/Rx) coil array was designed, simulated, and tested for cardiac magnetic resonance imaging (cMRI) of pigs at 7 T. The cardiac array was composed of 16 elements with physically independent anterior and posterior parts. The array was connected to the MRI scanner in the parallel transmit (pTx) mode forming an 8-channel transmit and 16-channel receive (8Tx/16Rx) coil configuration. The anterior array was composed of four central octagonal elements, which were decoupled using a common central ring (CCR) and shared decoupling capacitors. The surrounding four triangular elements were decoupled from the central four elements using gaps and capacitive decoupling. In total, the eight elements of the anterior array resembled a coil with a symmetrical circular shape. Due to the advantageous arrangement of the elements in conjunction with the novel decoupling method of a CCR, the coupling between the adjacent loop elements was minimized. The posterior array was built using a $4 \times 2$ standard rectangular, symmetric element configuration. The dedicated cardiac array was tested in phantom and in ex vivo MR measurements with a female pig of 46 kg. The dedicated coil array enhanced the signal-to-noise ratio (40 ± 27) in ex vivo measurements of the pig heart by about three times compared to a coil prototype for cardiac human imaging (11.8 ± 7). High-resolution, ex vivo cardiac images were acquired with an in-plane resolution of up to 0.3 mm $\times0.3$ mm using the dedicated pig coil array. The novel cardiac array supports parallel imaging with an acceleration factor (R) of 4 without increasing the mean $g$ -factor within the heart region beyond 1.15.