Endoluminal coils for interventional MRI procedures

Abstract

In this study we designed endoluminal magnetic resonance imaging (MRI) coils to be used for interventional procedures under the guidance of MRI. The first coil we developed is a two-channel endocervical coil for the treatment of cervical cancer. The coil was embedded into the brachytherapy applicator without interfering with its functions. It provides magnetic resonance (MR) images of the cervix with high signal-to-noise ratio (SNR) that is required for a more accurate radiation dose calculation in the treatment of cervical cancer with high dose rate brachytherapy (HDRB). The performance of this coil was tested with phantom experiments and the results proved that the design worked properly. Second, we developed an MRI guidewire and an MR EP catheter for the treatment of atrial fibrillation (AF). The MRI guidewire had similar mechanical properties with the common cardiovascular guidewires and it was proved successful in obtaining high SNR images of the heart. The MR EP catheter could also provide high SNR images as well as clean intracardiac electrocardiogram (IECG) signal during the MR scan. Due to the loopless antenna embedded inside both of these catheters, they could be navigated in the body under the MRI. They may be used to guide complex interventional procedures such as RF ablation. The performance of these catheters was tested and confirmed with in vitro experiments. To sum up, these two technologies can play a significant role in the treatment of cervical cancer and AF as well as contributing to the development of interventional MRI.