Technical considerations: CT and MR imaging in the postoperative orthopedic patient.

Cross-sectional imaging utilizing computed tomography (CT) and magnetic resonance (MR) imaging have become routine components in the imaging assessment of patients with musculoskeletal disease. Unfortunately, in the setting of a postoperative orthopedic patient with associated orthopedic metallic instrumentation, these imaging techniques are prone to artifacts resulting in image quality degradation. An understanding of the physical basis of such metal-related artifacts, and their appearance on CT and MR imaging, has led investigators to the implementation of a series of techniques and modifications to imaging protocols to decrease CT and MR imaging artifacts in the vicinity of metallic instrumentation. Utilizing such modified imaging techniques, consistent, improved CT and MR image quality may be achieved in imaging of the postoperative orthopedic patient.