With the advent of an aging society, the incidence of degenerative changes in the hip and knee joints (commonly referred to as osteoarthritis) is on the rise, and end-stage osteoarthritis that has failed to respond to various conservative treatments such as physical therapy, heat, oral medications, and joint cavity injections has to be replaced with an artificial joint. Currently, artificial joint replacement is one of the most successful orthopaedic surgeries of the 20th century, with unparalleled advantages in improving the symptoms and restoring the function of the hip and knee. It has even been called a “landmark surgery”. However, because most of the patients undergoing the surgery are elderly and often have a combination of underlying diseases such as hypertension, diabetes, heart disease, Parkinson’s, etc., they often have to be evaluated after the surgery due to these diseases, the most widely used and common of which are MRI and CT. Many hospital imaging departments are cautious about post-arthroplasty patients. Often, patients come from far and wide to ask if they can have an MRI. In fact, most of the materials used in the clinic for artificial joint prostheses are made of alloys, such as cobalt-chromium-molybdenum, ceramic, polyethylene, polymethyl methacrylate (commonly known as bone cement), etc. These materials are safe at low magnetic field strengths (less than 1.5T) and can be used for MRI examinations.