Toward Densely Populated Dipole Arrays for Human Prostate Imaging at 7T: 8Tx16Rx Coaxial-End Dipole Array

Motivation: To improve SNR and the SAR-performance in prostate imaging at 7T using a densely populated coaxial-end dipole array. Goal(s): To numerically optimize and evaluate an 8Tx/16Rx coaxial-end dipole array for prostate imaging at 7T. Approach: Geometry of a coaxial-end element was optimized to minimize peak SAR and improve coverage. In transmission, 16 coaxial-end dipoles were combined into 8 pairs. This further reduced pSAR. 8-element fractionated dipole and stripline arrays were simulated for comparison. Results: Optimized 8Tx/16Rx coaxial-end dipole array improved SNR in prostate compared to all other 8-element arrays. SAR-performance of the developed array was better than that of other dipole arrays. Impact: We demonstrated that densely populated 16-element coaxial-end dipole array improved SNR in the prostate by at least 10% compared to 8-element arrays. In addition, combining 16 elements in 8 pairs during transmission improved SAR-performance in comparison to the 8-channel array.