Design and development of a novel flexible ultra‐short echo time (FUSE) sequence

Abstract

AbstractPurposeTo present the validation of a new Flexible Ultra‐Short Echo time (FUSE) pulse sequence using a short‐T2 phantom.MethodsFUSE was developed to include a range of RF excitation pulses, trajectories, dimensionalities, and long‐T2 suppression techniques, enabling real‐time interchangeability of acquisition parameters. Additionally, we developed an improved 3D deblurring algorithm to correct for off‐resonance artifacts. Several experiments were conducted to validate the efficacy of FUSE, by comparing different approaches for off‐resonance artifact correction, variations in RF pulse and trajectory combinations, and long‐T2 suppression techniques. All scans were performed on a 3 T system using an in‐house short‐T2 phantom. The evaluation of results included qualitative comparisons and quantitative assessments of the SNR and contrast‐to‐noise ratio.ResultsUsing the capabilities of FUSE, we demonstrated that we could combine a shorter readout duration with our improved deblurring algorithm to effectively reduce off‐resonance artifacts. Among the different RF and trajectory combinations, the spiral trajectory with the regular half‐inc pulse achieves the highest SNRs. The dual‐echo subtraction technique delivers better short‐T2 contrast and superior suppression of water and agar signals, whereas the off‐resonance saturation method successfully suppresses water and lipid signals simultaneously.ConclusionIn this work, we have validated the use of our new FUSE sequence using a short T2 phantom, demonstrating that multiple UTE acquisitions can be achieved within a single sequence. This new sequence may be useful for acquiring improved UTE images and the development of UTE imaging protocols.