Traditional Posters: Interventional - ismrm

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 multislice,
parallel imaging systems for MR-guided interventions. Ghosting is caused by discontinuities in Fourier space along the phaseencoding
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.