PURPOSE: Turbo spin echo (TSE) imaging reduces imaging time by acquiring multiple echoes per repetition (TR), requiring fewer TRs. O-space can also require fewer TRs by using a combination of nonlinear magnetic gradient fields and surface coil arrays. Although to date, O-space has only been demonstrated for gradient echo imaging, it is valuable to combine these two techniques. However, collecting multiple O-space echoes per TR is difficult because of the different local k-space trajectories and variable T2-weighting. THEORY AND METHODS: A practical scheme is demonstrated to combine the benefits of TSE and O-space for highly accelerated T2-weighted images. The scheme uses a modified acquisition order and filtered projection reconstruction to reduce artifacts caused by T2 decay, while retaining T2 contrast that corresponds to a specific echo time. RESULTS: The experiments revealed that the proposed method can produce highly accelerated T2-weighted images. Moreover, the method can generate multiple images with different T2 contrasts from a single dataset. CONCLUSIONS: The proposed O-space TSE imaging method requires fewer echoes than conventional TSE and fewer repetitions than conventional O-space imaging. It retains resilience to undersampling, clearly outperforming Cartesian SENSE at high levels of undersampling, and can generate undistorted images with a range of T2 contrast from a single acquired dataset.
PURPOSE: Turbo spin echo (TSE) imaging reduces imaging time by acquiring multiple echoes per repetition (TR), requiring fewer TRs. O-space can also require fewer TRs by using a combination of nonlinear magnetic gradient fields and surface coil arrays. Although to date, O-space has only been demonstrated for gradient echo imaging, it is valuable to combine these two techniques. However, collecting multiple O-space echoes per TR is difficult because of the different local k-space trajectories and variable T2-weighting. THEORY AND METHODS: A practical scheme is demonstrated to combine the benefits of TSE and O-space for highly accelerated T2-weighted images. The scheme uses a modified acquisition order and filtered projection reconstruction to reduce artifacts caused by T2 decay, while retaining T2 contrast that corresponds to a specific echo time. RESULTS: The experiments revealed that the proposed method can produce highly accelerated T2-weighted images. Moreover, the method can generate multiple images with different T2 contrasts from a single dataset. CONCLUSIONS: The proposed O-space TSE imaging method requires fewer echoes than conventional TSE and fewer repetitions than conventional O-space imaging. It retains resilience to undersampling, clearly outperforming Cartesian SENSE at high levels of undersampling, and can generate undistorted images with a range of T2 contrast from a single acquired dataset.
Authors: Gigi Galiana; Jason P Stockmann; Leo Tam; Dana Peters; Hemant Tagare; R Todd Constable Journal: Concepts Magn Reson Part A Bridg Educ Res Date: 2012-09-26 Impact factor: 0.481
Authors: Daniel Gallichan; Chris A Cocosco; Andrew Dewdney; Gerrit Schultz; Anna Welz; Jürgen Hennig; Maxim Zaitsev Journal: Magn Reson Med Date: 2010-11-30 Impact factor: 4.668
Authors: Gerrit Schultz; Hans Weber; Daniel Gallichan; Walter R T Witschey; Anna M Welz; Chris A Cocosco; Jürgen Hennig; Maxim Zaitsev Journal: IEEE Trans Med Imaging Date: 2011-08-12 Impact factor: 10.048
Authors: Jason P Stockmann; Gigi Galiana; Leo Tam; Christoph Juchem; Terence W Nixon; R Todd Constable Journal: Magn Reson Med Date: 2012-05-14 Impact factor: 4.668
Authors: Dan Ma; Vikas Gulani; Nicole Seiberlich; Kecheng Liu; Jeffrey L Sunshine; Jeffrey L Duerk; Mark A Griswold Journal: Nature Date: 2013-03-14 Impact factor: 49.962