Analysis of MRI Artifacts Induced by Cranial Implants in Phantom Models

Background/Objectives: Cranial reconstruction (cranioplasty) is a surgical procedure performed to restore skull function and aesthetics following trauma, oncological conditions, or congenital defects. Magnetic resonance imaging (MRI) is commonly used for the postoperative monitoring and diagnosis of patients with cranial implants. However, MRI artifacts caused by these implants can compromise imaging accuracy and diagnostic precision. This study aims to evaluate the extent of MRI artifacts caused by titanium and polyether ether ketone (PEEK) cranial implants and to identify optimal imaging sequences to minimize these artifacts. Methods: Phantom skull models with cranial defects of varying sizes (one-quarter, one-third, and one-half of the skull) were used to simulate real-world clinical conditions. The defects were filled with a water-based medium containing simulated brain tissue and tumor models. Custom 3D-printed titanium and PEEK cranial implants were fixed onto the phantom skulls and scanned using 1.5 T and 3 T MRI scanners. Various imaging sequences were tested, with a focus on optimizing parameters to reduce artifact formation. Turbo Spin Echo (TSE) sequences with fat saturation were implemented to assess their effectiveness in artifact reduction. Results: The study found that MRI artifacts varied based on the implant material, defect size, and magnetic field strength. A higher field strength (3 T) resulted in more pronounced artifacts. However, the use of TSE sequences with fat saturation significantly reduced artifacts and improved lesion visualization, enhancing diagnostic accuracy. Conclusions: This research highlights the importance of optimized MRI protocols when imaging patients with cranial implants. Proper selection of imaging sequences, particularly TSE with fat saturation, can mitigate artifacts and improve diagnostic precision, ultimately benefiting patient outcomes in clinical radiology.