SAR evaluations of head with carotid stent during MR imaging

Modern MRI systems employ high-frequency and high-powered radio frequency (RF) pulses. Given this, it is necessary to evaluate the specific absorption rate (SAR) of the irradiated human body. Recently, the materials and shapes of implantable medical devices such as artificial joints or pacemakers have become increasingly diverse. At once, making it more likely that subjects´ implanted medical devices will affect MR imaging, potentially causing temperature increases in unexpected regions. Despite this, guidelines for evaluating the effects of such cases on the human body are still unclear. Therefore, in order to consider the safety of patients with implanted medical devices during MR imaging, it is necessary to comprehend the detailed SAR distribution within the human body. While many existing studies have addressed cases involving pacemakers, none have dealt with carotid stents. In Japan, 10,000 carotid endarterectomies and carotid artery stents are carried out each year. In this study, we evaluate the SAR distribution within the head embedding the carotid stents as an example of implanted medical devices.