Time and SAR efficiency in Imaging of Metal Orthopedic Hardware Utilizing Optimized Turbo Spin Echo Sequences

Motivation: Metal artifact reduction sequences suffer from SAR resulting in longer scans. Goal(s): Our goal was to reduce the sequence SAR without compromising image contrast and image quality. Approach: We propose an optimization framework to design variable refocusing flip angles to minimize SAR while maintaining image quality comparable to clinical sequence. The prototype sequence was tested on a cohort of patients with metallic implants at 1.5T. Results: The variable flip angle sequence generates images of comparable quality as conventional clinical acquisition while allowing savings in SAR and acquisition time. Impact: Metal artifact reduction sequences that utilize the proposed variable flip angle framework result in lower SAR and scan time without any loss in image quality.