Reevaluation of T2-weighted fast field echo (T2FFE): application to rapid volumetric black-blood imaging

Abstract

T₂-fast field echo (T2FFE) sequence is a rapid T₂-weighted steady state free precession sequence, but has not become a widely utilized MR-imaging strategy because of its low signal-to-noise ratio and high sensitivity to motion. These effects have seriously limited the clinical use of T2FFE and therefore T2FFE has not been used for routine clinical studies. Nevertheless, in this study, we have investigated the possibility of clinical application by re-optimization of the T2FFE on the current MRI systems. Our purpose in this study was to explore the sensitivity of T2FFE to flow spins using a flow phantom and a contrast optimization/comparison with 2D turbo spin-echo (TSE) T₂-weighted images, and to evaluate its feasibility in volunteers and patients. This study demonstrated that the T2FFE sequence achieves rapid 3D T₂-weighted black-blood imaging while minimizing the impact of motion using a low flip angle under the shortest repetition time and the shortest echo time conditions. Furthermore, 3D T2FFE with use of an optimal flip angle (30°-40°) can provide contrast equivalent to that of 2D TSE T₂-weighted images. This proposed T2FFE sequence might be promising for numerous clinical applications.