TRADITIONAL POSTER - ismrm

Poster Sessions
1856. Post-Mortem In-Situ Vs in Vitro and in Vivo RF Safety Evaluation of a Two-Channel Intravascular
Active Guidewire for Cardiovascular Interventional MRI
Christina E. Saikus 1 , Merdim Sonmez 1 , Israel M. Barbash 1 , Vincent Wu 1 , Jamie A. Bell 1 , Christopher J.
Yeung 1 , Robert J. Lederman 1 , Ozgur Kocaturk 1
1 Translational Medicine Branch, Division of Intramural Research, National Heart Lung and Blood Institute, National Institutes of
Health, Bethesda, MD, United States
Devices for interventional MRI must be evaluated for potential radiofrequency induced heating but phantom heating tests can be difficult to relate to
intended uses in vivo. We examined in vivo and post-mortem in situ device heating in swine and more realistic phantom in vitro testing of an actively
visualized guidewire for interventional cardiovascular MRI.
1857. An Integrated CMOS Detector for MR Image Guided Interventions
Jens Anders 1 , Paul SanGiorgio 1 , Giovanni Boero 1 , Xenia Deligianni 2 , Sunil Patil 2 , Klaus Scheffler 2
1 Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland; 2 University of Basel, University Hospital, Basel,
Switzerland
In this work, standard CMOS technology is used to miniaturize highly integrated active tracking devices in MR image guided interventions. The presented
microsystem contains a detection coil, a tuning capacitor, a low-noise amplifier, a downconversion mixer and a low-frequency gain stage on a single
integrated circuit. Downconverting the NMR signal to a few kilohertz on chip significantly reduces losses in the cables and thereby facilitates the use of the
system in small catheters. The feasibility of the approach is demonstrated with phantom experiments in a standard 1.5 T clinical scanner.
1858. A Method to Eliminate Motion-Related Ghosting Artifacts from Images of Active Devices During
Parallel Imaging
Ashvin Kurian George 1 , Christina E. Saikus 1 , Ozgur Kocaturk 1 , Robert J. Lederman 1 , Anthony Z.
Faranesh 1
1 National Institutes of Health, Bethesda, MD, United States
We present a method to remove the ghosting artifact from images formed from under-sampled active device data such as in multi-slice, parallel imaging
systems for MR-guided interventions. Ghosting is caused by discontinuities in Fourier space along the phase-encoding direction. The method works by first
forming an image from temporally-local, under-sampled Fourier data. This image contains periodically repeated copies in the phase-encoding direction. The
non-ghost period of each column is determined by using the view-shared image and exploiting the correlation of the active device image across columns.
1859. Automatic Device Tracking in a Closed-Bore MRI: Principle and Initial Experimental Results on a
Robotically Driven Needle
Gregor Thörmer 1 , Nikita Garnov 1 , Jürgen Haase 2 , Thomas Kahn 1 , Michael Moche 1 , Harald Busse 1
1 Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany; 2 Physics and Geosciences Department,
Leipzig University, Leipzig, Germany
Localization and tracking of devices in a closed-bore scanner may improve the accuracy and workflow of MR-guided interventions and also reduce a
potential user bias. The goal was to evaluate the performance of a novel image-based approach for device tracking which is demonstrated in a phantom
experiment with a robotically driven needle inside the magnet. The presented method is based on the automatic localization of wireless MR-visible markers
in poorly resolved MR images. Integration of the localization algorithm into a custom-made pulse sequence with interleaved anatomical imaging would
provide a relatively simple and safe alternative to other tracking approaches.
1860. A Multi-Slice Interactive Real-Time Sequence Integrated with the EndoScout Tracking System for
Interventional MR Guidance
Kun Qing 1,2 , Li Pan 1,3 , Barry Fetics 4 , Frank K. Wacker 5 , Steffi Valdeig 5 , Mathew Philip 4 , Amir Roth 4 , Erez
Nevo 4 , Dara L. Kraitchman 5 , Andre J. van der Kouwe 6 , Christine H. Lorenz 1,7
1 Center for Applied Medical Imaging, Siemens Corporation, Corporate Research, Baltimore, MD, United States; 2 Department of
Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3 Department of Radiology and Radiological
Science, Johns Hopkins University, Baltimore, MD, United States; 4 Robin Medical Inc., Baltimore, MD, United States; 5 Department
of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 6 Department of Radiology, Harvard
Medical School, Brookline, MA, United States; 7 Department of Radiology and Radiological Science, Johns Hopkins University,
Baltimore, MD, United States
The purpose of the present work was to integrate the EndoScout tracking technique into a multi-slice interactive real-time sequence to assist MR guided
interventions. The sequence was modified to provide the excitation gradients fed into the Endodoscout system for sensor tracking. The position and
orientation of the surgical device is real-time updated and superimposed either on pre-acquired images or real-time images during the procedures. The
multi-slice real-time images were displayed to enable both surgical device guidance and underlying tissue monitoring. Animal study suggests that MR
guidance using the integrated system is feasible and effective at performing interventional procedures.
1861. Phase Only Cross-Correlation Tracking of a Passive Marker for MR-Guided Interventions
Roger Jason Stafford 1 , Florian Maier 2 , Axel Joachim Krafft 2 , Michael Bock 2 , Axel Winkel 3 , Kamran Ahrar 4
1 Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center , Houston, TX, United States; 2 Department
of Medical Physics in Radiology, Cancer Research Center Heidelberg (DKFZ), Heidelberg, Germany; 3 Invivo GMBH, Schwerin,
Germany; 4 Department of Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States
Real-time MR-guidance of percutaneous procedures may benefit from methods for automatically adjusting the scan prescription to the needle trajectory, as
well as visual delineation of the trajectory, in real-time. In this work, the feasibility of using a phase only cross correlation tracking algorithm for automated