TRADITIONAL POSTER - ismrm

Poster Sessions
refocusing flip angles. Volunteer experiments were acquired in 3D low refocusing flip angle TSE (LOWRAT) using a 3.0T imager. The optimal parameter
for T1-optimized black-blood imaging was low excitation flip angles, low refocusing flip angles, NPHA pseudo steady-state preparation, short ETL, best
echo number for K-space center=2nd echo, and shortest TR. Contrast behavior of 3D LOWRAT T1W was similar to that of 2D SE. This optimal sequences
can be used for 3D volumetric T1 weighted black-blood imaging.
3032. Rapid Optimization of Acquisition Parameters for Fast Spin Echo Imaging in RF Power Constrained
Regimes
Robert Marc Lebel 1 , Alan W. Wilman 1
1 Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
At high field strengths, fast spin echo is a SAR constrained procedure; parameter concessions are required to enable its use. Typical modifications include
elongated RF pulses and reduced refocusing angles. We present an SNR analysis investigating the effects of reduced angles (lower signal) and longer RF
pulses (less readout time) and present a reliable method for rapidly selecting these parameters to optimize the SNR for a given target power level.
3033. Reduced SAR with BASE Sequence at 7 Tesla
Daniel Neumann 1 , Morwan Choli 2 , Martin Blaimer 2 , Michael Bock 3 , Felix Breuer 2 , Peter M. Jakob 4
1 Experimental Physics 5, University of Würzburg, Würzburg, Germany; 2 Experimental Physics 5, Research Center Magnetic
Resonance Bavaria (MRB), Würzburg, Germany; 3 Department of Medical Physics in Radiology, German Cancer Research Center
(dkfz), Heidelberg, Germany; 4 Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany
The step towards higher magnetic fields on the one hand provides a stronger NMR signal while on the other hand SAR is significantly increased in
comparison with standard clinical scanners. Therefore the application of sequences using many refocusing pulses such as TSE can be difficult.
In this work we examine the potential of the BASE sequence to obtain high resolution images at 7T. BASE is a combination of BURST and multiple
refocusing pulses. However, compared to TSE, there are a lower number of pulses and therefore SAR could be reduced by a factor of four.
3034. Whole-Brain FLAIR Using 3D TSE with Variable Flip Angle Readouts Optimized for 7 Tesla
John W. Grinstead 1 , Oliver Speck 2 , Dominik Paul, Lisa Silbert 3 , Louis Perkins 3 , William Rooney 3
1 Siemens Healthcare, Portland, OR, United States; 2 Biomedical Magnetic Resonance, Otto-von-Guericke-University, Magdeburg,
Germany; 3 Oregon Health and Science University
Routine FLAIR uses a 2D inversion-recovery turbo spin echo pulse sequence having many high-SAR RF pulses, allowing only a few slices to be acquired at
7 Tesla. Recent work demonstrated the feasibility of using 3D IR-TSE with a T2-prepared IR and a reduced flip angle readout of 70 degrees to perform
whole brain FLAIR at 7 Tesla for the first time. The present work extends this approach with a variable flip angle readout optimized for the T1 and T2
values of brain tissues at 7 Tesla to further improve the SAR, contrast, and SNR performance.
3035. Inversion of a Non-CPMG Fast Spin Echo Train.
Patrick H. Le Roux 1
1 Applied Science Lab, GE Healthcare, Palaiseau, IDF, France
The non-CPMG sequence permits to acquire MR signal in the Fast Spin Echo mode even when the CPMG (Carr Purcell Meiboom Gill) phase conditions
cannot be fulfilled. It consists in a quadratic phase modulation of the refocusing pulses train, preceded by a suitable preparation period. It turns out that this
sequence of RF pulses can be readily inversed permitting a perfect Driven Equilibrium scheme to be applied.
3036. Verse-Space
Guobin Li 1 , Christoph Sauerbier 2 , Dominik Paul 3 , Weijun Zhang 1 , Qiang He 1 , Marc Beckmann 1 , Lars
Lauer 3
1 Siemens Mindit Magnetic Resonance Ltd., Shenzhen, Guang Dong, China; 2 Hochschule Furtwangen University, Germany; 3 Siemens
Medical Solutions, Erlangen, Germany
Slab selection by the dual echo-spacing technique in SPACE with non-selective refocusing pulses needs averaging with phase cycling ans is sensitive to
chemical shift artifacts during excitation. A new technique, VERSE-SPACE is presented in this abstract to provide faster acquisition speed and better slab
profile than the previous technique.
3037. Multi-Slab SPACE
Guobin Li 1 , Dominik Paul 2 , Weijun Zhang 1 , Tallal Charles Mamisch 3 , Qiang He 1 , Marc Beckmann 1 , Lars
Lauer 2
1 Siemens Mindit Magnetic Resonance Ltd., Shenzhen, Guang Dong, China; 2 Siemens Medical Solutions, Erlangen, Germany;
3 Department of Orthopaedic Surgery, Inselspital, University of Berne, Bern, Switzerland
In Single Slab SPACE, relative short TR and long echo train have to be used to reduce the total acquisition time into clinical acceptable range at the cost of
the degradation in contrast purity and SNR, especially in PDw imaging. A new Multi-Slab SPACE is presented here to further increase the sampling
efficiency, and then provides more flexibility to use longer TR and shorter echo train acquisition compared to Single Slab SPACE.
3038. Fast Spin-Echo Imaging of Inner Field-Of-Views Using 2D-Selective RF Excitations
Jürgen Finsterbusch 1,2
1 Department of Systems Neuroscience , University Medical Center Hamburg-Eppendorf, Hamburg, Germany; 2 Neuroimage Nord,
University Medical Centers Hamburg-Kiel-Lübeck, Hamburg-Kiel-Lübeck, Germany
Fast spin-echo imaging suffers from image blurring if a large number of echoes per excitation (turbo factor) is used and, in particular at higher magnetic
fields, from SAR limitations. Focussing the field-of-view to a small inner volume reduces the number of required echoes considerably and thus ameliorates