Reversed half-echo stack-of-stars TrueFISP (TrueSTAR).
To introduce a reversed half-echo readout scheme for artifact-free two-dimensional (2D) radial and three-dimensional (3D) stack-of-stars TrueFISP imaging, termed TrueSTAR.



TrueSTAR imaging (echo time [TE]/repetition time [TR] = 0.94/1.62 ms for 2D, TE/TR = 0.85/1.21 ms for 3D) was evaluated in phantoms and for in vivo chest imaging at 1.5T and was compared with contemporary center-out (TE/TR = 0.66/1.62 ms for 2D, TE/TR = 0.36/1.21 ms for 3D) and symmetric (TE/TR = 0.93/1.86 ms for 2D, TE/TR = 0.85/1.70 ms for 3D) radial acquisition schemes in terms of image quality and severity of artifacts.



Images obtained using a center-out sampling scheme were blurred as a result of trajectory inconsistencies in the k-space center, whereas in vivo acquisitions with symmetric sampling were prone to banding artifacts from the increased TR, compared with center-out and TrueSTAR acquisitions. In contrast, TrueSTAR imaging inherits both benefits, namely, a short TR from the half-echo readout, resulting in reduced banding artifacts, and a high trajectory fidelity in the k-space center from center-in trajectories, yielding an improved signal homogeneity. In addition, near artifact-free 3D TrueSTAR chest imaging (TE/TR = 0.88/1.27 ms) is demonstrated at 3T.



TrueSTAR makes use of a generic radial sampling scheme that mitigates residual MR system imperfections, offering artifact-free chest imaging at 1.5T. Magn Reson Med 76:583-590, 2016. © 2015 Wiley Periodicals, Inc.
Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.|Department of Biomedical Engineering, University of Basel, Basel, Switzerland.
Grzegorz
G
Bauman
Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland.|Department of Biomedical Engineering, University of Basel, Basel, Switzerland.
Oliver
O
Bieri
D000465:Algorithms; D016477:Artifacts; D003627:Data Interpretation, Statistical; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
TrueFISP; non-Cartesian trajectories; radial MRI; steady-state free precession