Improving MR Image Quality in Patients with Metallic Implants

The number of implanted devices such as orthopedic hardware and cardiac implantable devices continues to increase with an increase in the age of the patient population, as well as an increase in the number of indications for specific devices. Many patients with these devices have or will develop clinical conditions that are best depicted at MRI. However, implanted devices containing paramagnetic or ferromagnetic substances can cause significant artifact, which could limit the diagnostic capability of this modality. Performing imaging with MRI when an implant is present may be challenging, and there are numerous techniques the radiologist and technologist can use to help minimize artifacts related to implants. First, knowledge of the presence of an implant before patient arrival is critical to ensure safety of the patient when the device is subjected to a strong magnetic field. Once safety is ensured, the examination should be performed with the MRI system that is expected to provide the best image quality. The selection of the MRI system includes multiple considerations such as the effects of field strength and availability of specific sequences, which can reduce metal artifact. Appropriate patient positioning, attention to MRI parameters (including bandwidth, voxel size, and echo), and appropriate selection of sequences (those with less metal artifact and advanced metal reduction sequences) are critical to improve image quality. Patients with implants can be successfully imaged with MRI with appropriate planning and understanding of how to minimize artifacts. This improves image quality and the diagnostic confidence of the radiologist. (C) RSNA, 2021