Warning signs can often be found at the entrance to the magnetic resonance imaging (MRI) examination room: No metal objects are allowed inside. Before a patient undergoes an MRI, the radiographer will also ask if the patient has metal endosseous, such as metal dentures, cardiovascular stents, pacemakers, artificial joints, and internal fixation plates. Radiographers often refuse to perform an MRI if the patient has non-removable implants. This is because MRI equipment produces a strong magnetic field that attracts ferromagnetic objects (mainly metals containing iron) to move, which can cause injury if the patient is wearing such objects or has ferromagnetic endosomes in his or her body. Secondly, the electromagnetic waves emitted during MRI scanning can cause certain metals, such as aluminum, to generate heat and increase the temperature of the surrounding tissues, resulting in local damage to the patient. Finally, the presence of metals can cause loss and distortion of the MRI signal, resulting in metal artifacts and distortion of the image around the metal, which can seriously affect the interpretation of the image. Therefore, some orthopedic surgeons or radiologists list all metallic endophytes as contraindications to MRI and immediately refuse to give MRI examinations to patients upon hearing that they have metallic endophytes. However, it is well known that MRI is an ideal tool for diagnosing skeletal and muscular system disorders because of its superior soft tissue contrast, multidimensional scanning capability and absence of ionizing radiation, especially in cases such as post-arthroplasty pain, where conventional imaging does not provide sufficient information. Can MRI be performed on all metallic endosseous materials? Safety studies have confirmed that some metallic materials can be used for MRI. Titanium and titanium alloys are non-magnetic, making endosseous devices safe for MRI, and even titanium surgical tools can be used by physicians to operate with MRI detection. Secondly, although cobalt is ferromagnetic, cobalt-chromium has been shown to have very low magnetism and is safe for MRI. It has also been shown that IUDs with copper rings are safe for MRI, and that copper-containing IUDs neither move nor heat up, even in strong magnetic fields at 3T. Although some stainless steels have extremely low magnetic susceptibility, tools made of medical stainless steel can be used in the MRI room, and MRI examinations of medical stainless steel implants have been shown to be safe, but MRI examinations of areas near medical stainless steel implants are not recommended because the MRI artifacts produced by medical stainless steel are so great that the image quality is severe. Since the materials of artificial joints commonly used today do not exceed the metal materials mentioned above, MRI examinations can be safely performed after artificial joint replacement. With the development of MRI equipment and techniques in recent years, especially the development of metal artifact reduction techniques, the local MRI imaging clarity of the metal endosseous has been greatly improved, and the diagnostic use of MRI after prosthetic arthroplasty has become more and more widespread. MRI has been reported to have the highest accuracy for assessing periprosthetic osteolysis and wear particle-induced synovitis, and is also uniquely suited for assessing periarticular soft tissue and vascular-neural structures. This technique can also be applied to other postoperative orthopedic endoprosthetic examinations, such as determining the degree of fracture healing after internal fracture fixation, the presence of infection, and the presence of femoral head necrosis after hip fracture surgery. In general, MRI is safe to perform after prosthetic joint replacement and conventional internal fixation. Patients with pacemakers and cochlear implants should not undergo MRI because of the strong magnetic field that may cause electronic malfunction. MRI is also contraindicated in patients with cardiac stents and arterial clips due to the presence of ferromagnetic materials, and in patients wearing nickel-containing metal dentures that are not removable. In any case, patients should inform the radiographer of the type and material of their implants before the MRI is performed.