Improvement of Late Phase Vessel Visibility by Applying TI Dependent Optimized Reconstruction (TIDOR)to Variable TI Ultrashort TE 4D-MRA [Presidential Award Proceedings]

Abstract

　In this study, we combined TI dependent optimized reconstruction (TIDOR) with Variable TI UTE 4D-MRA and demonstrated the clinical usefulness of this combined method. Previously, we reported that the late phase vessel visibility of ASL based UTE 4D-MRA was improved by the Variable TI method, which has the extended TI in a manner of progression of difference to keep labeled magnetization away from saturation in late phases⁵⁾. For further improvement of peripheral vessel visibility, we developed the TIDOR, which takes into account the signal and noise level of each phase. Combining Variable TI UTE 4D-MRA with TIDOR improved the peripheral vessel visibility, especially in the late phases. We demonstrated that this method is effective for clinical applications.