When a patient takes an MRI scan, the patient has a risk of unexpected injuries due to the intensive electromagnetic (EM) field. Among the injuries, the tissue heating by the time-varying EM field is one of the main issues. Since an implanted artificial structure with a conductive material aggravates the heating effect, lots of studies have been conducted to investigate the effect around the implants. In this review article, a mechanism of RF heating around the implants and related studies are comprehensively investigated.