ELECTRONIC POSTER - ismrm

14:30 5021. Self-Gating Reconstruction of Multiple Respiratory Phases Using Undersampled
Golden-Radial Phase Encoding Trajectory
Christian Buerger 1 , Tobias Schaeffter 1 , Claudia Prieto 1
1 Division of Imaging Sciences, King's College London, London, United Kingdom
A new self-gating acquisition scheme allowing the retrospective reconstruction of several respiratory phases is proposed. This
approach takes advantage of the recently introduced Golden-Radial Phase Encoding (G-RPE) trajectory and uses the, inherently
acquired, central k-space profiles to derive the respiratory motion signal. The method was tested in in-vivo data using a 32-channel
coil and 3 different respiratory phases were reconstructed from undersampled data using non-Cartesian SENSE reconstruction.
15:00 5022. Phase Navigator for Respiratory Triggering
Alto Stemmer 1 , Berthold Kiefer 1
1 Healthcare Sector, Siemens AG, Erlangen, Germany
In this work the signal for respiratory triggering is derived with a navigator that measures respiratory induced off-resonance effects.
The advantages compared to a liver dome navigator are the compatibility with short bore scanners and that no navigator positioning is
necessary.
Prospective Motion Correction
Hall B Monday 14:00-16:00 Computer 121
14:00 5023. Combination of Prospective and Retrospective Motion Correction for Multi-
Channel MRI
Chaiya Luengviriya 1,2 , Jian Yun 1 , Oliver Speck 1
1 Department of Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany;
2 Department of Physics, Kasetsart University, Bangkok, Thailand
Real-time prospective correction is a very promising method to avoid image quality degradation caused by subject motion in MRI of
human brain. The inaccuracy of measured motion data is limiting the efficiency. Simulations showed that residual motion artifacts
after a prospective correction increased with the level of inaccuracy. Even for an ideal accurate case, artifacts can appear in multichannel
MRI because of coil sensitivity map errors. A retrospective correction was proposed and showed that the image quality can be
further improved, especially for strong motion. In all cases, smooth motion resulted in fewer artifacts than abrupt motion.
14:30 5024. MR Compatible Sensor for Motion Artifact Corrected Reconstruction Method
Laure Rousselet 1,2 , Maélène Lohezic, 23 , Damien Mandry, 2,4 , Cédric Pasquier 5 , Jacques
Felblinger 1,2
1 IADI, Nancy-Université, Nancy, France; 2 U947, Inserm, Nancy, France; 3 Global Applied Science Lab., GE
Healthcare, Nancy, France; 4 CHU de Nancy, Nancy, France; 5 CIC801, INSERM, Nancy, France
The goal of this work was to develop a MR compatible sensor which aims at measuring the acceleration of a localized region of the
body. It has been integrated to a motion compensated reconstruction (GRICS) as a physiological input to reduce respiratory artifacts
and improve image quality.
GRICS reconstructions, performed with respiratory belt and with accelerometer, were compared to breath-hold images and averaged
free breathing acquisitions. Accelerometer gives similar results to respiratory belts and to breath-hold. Moreover, it is easier to install
on patient.
15:00 5025. Self-Encoded Marker Design for Adaptive Optical Real-Time Motion Correction
Christoph Forman 1 , Murat Aksoy 2 , Matus Straka 2 , Joachim Hornegger 1 , Roland
Bammer 2
1 Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-University Erlangen-
Nuremberg, Erlangen, Germany; 2 Department of Radiology, Stanford University, Stanford, CA, United States
Patient motionis one of the unsolved problems in MRI. In this study, we propose a novel large field of view marker design to be used
with a monovision based system to correct for rigid head motion. The proposed marker design has gives better accuracy and can
correct for larger patient head motion.
15:30 5026. Fast Cross-Calibration Between MR Scanner and Optical System for Prospective
Motion Correction
Murat Aksoy 1 , Christoph Forman 1 , Matus Straka 1 , Samantha Jane Holdsworth 1 , Stefan
Tor Skare 1,2 , Joachim Hornegger 3 , Roland Bammer 1
1 Department of Radiology, Stanford University, Stanford, CA, United States; 2 Karolinska Institute, Stockholm,
Sweden; 3 Computer Science, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
Optical systems have been proposed as a way to achieve rigid head motion correction with minimal changes to the pulse sequence.
However, the usability of these systems in clinical practice have been limited mostly due to the tedious scanner-optical system crosscalibration
routine that is required to link the frame of references of the optical system and the MR scanner. In this study, we propose a
fast cross-calibration routine that is easy and takes only a couple of seconds. The variability of the scanner-camera cross calibration
parameters with varying sequence parameters was investigated.