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Higher frequencies and shorter wavelengths present significant design issues at ultra-high fields, making multi-channel array setup a critical component for ultra-high field MR imaging. The requirement for multi-channel arrays, as well as ongoing efforts to increase the number of channels in an array, are always limited by the major issue known as inter-element coupling. This coupling affects the current and field distribution, noise correlation between channels, and frequency of array elements, lowering imaging quality and performance. To realize the full potential of UHF MRI, we must ensure that the coupling between array elements is kept to a minimum. High-impedance coils allow array systems to completely realize their potential by providing optimal isolation while requiring minimal design modifications. These minor design changes, which demand the use of low capacitance on the conventional loop to induce elevated impedance, result in a significant safety hazard that cannot be overlooked. High electric fields are formed across these low capacitance lumped elements, which may result in higher SAR values in the imaging subject, depositing more power and, ultimately, providing a greater risk of tissue heating-related injury to the human sample. We propose an innovative method of utilizing high-dielectric material to effectively reduce electric fields and SAR values in the imaging sample while preserving the B1 efficiency and inter-element decoupling between the array elements to address this important safety concern with minimal changes to the existing array design comprising high-impedance coils.

Innovations in radiofrequency (RF) ablation and nonablative techniques have led to significant advances in addressing complex arrhythmogenic substrates for a variety of cardiac arrhythmias. Anatomical challenges, deep substrate, and mid-myocardial locations may pose difficulties and decrease success rates using routine methods. In this review, we provide an update on novel RF technology and techniques including (a) high-power, low-duration ablation, (b) ablation facilitated by low-ionic irrigant, and (c) bipolar ablation. In addition, we review emerging technologies including electroporation, needle catheter ablation, and ablation with the lattice catheter.

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