Julian Rauch1,2, Frederik B. Laun3, Theresa Palm3, Jan Martin3,4, Maxim Zaitsev5,6, Mark E. Ladd1,2,7, Peter Bachert1,2, and Tristan A. Kuder1
1Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany, 3Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany, 4Division of Physical Chemistry, Lund University, Lund, Sweden, 5Medical Physics, Department of Radiology, Faculty of Medicine, Medical Center University of Freiburg, Freiburg, Germany, 6High Field Magnetic Resonance Center, Center for Medical Physics and Biomedical Engineering Medical University of Vienna, Vienna, Austria, 7Faculty of Medicine, Heidelberg University, Heidelberg, Germany
1Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany, 3Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany, 4Division of Physical Chemistry, Lund University, Lund, Sweden, 5Medical Physics, Department of Radiology, Faculty of Medicine, Medical Center University of Freiburg, Freiburg, Germany, 6High Field Magnetic Resonance Center, Center for Medical Physics and Biomedical Engineering Medical University of Vienna, Vienna, Austria, 7Faculty of Medicine, Heidelberg University, Heidelberg, Germany
Additional oscillating
gradients in a double diffusion encoding imaging sequence remove the
concomitant phase induced by the used bipolar gradients and correct related
artifacts.
Figure
1: Schematic representation of the proposed method in a spin-echo double
diffusion encoding sequence. a) Bipolar diffusion-weighting gradients (blue)
are used for double diffusion encoding, here for instance along the physical x and y axes. These gradients induce additional
concomitant fields which cause severe artifacts. b) Oscillating gradients
(green) are implemented to null the concomitant fields induced by the bipolar
gradients.
Figure 4: Comparison of acquired magnitude images for the long phantom
cylinder orientated along the
z-axis. The images were corrected for diffusion
attenuation. a) Without concomitant field compensation, the image exhibits
strong artifacts, especially signal voids (q = 46 mm-1).
b) No concomitant field related artifacts can be seen when the concomitant
phase is removed by the oscillating gradients (q = 46 mm-1).
c) Image acquired with q = 0 mm-1
as reference.
