TRADITIONAL POSTER - ismrm

Poster Sessions
to monitor both the progress of the insertion and the procedure itself, such as core needle biopsy or tumor ablation. Flexibility was added to adjust the scan
plane in real-time and make tradeoffs between update display rate and image quality.
1840. A Passive, Image-Based Navigation Tool for Real-Time MR-Guided Percutaneous Interventional
Procedures
Wilhelm Strehl 1 , Eva Rothgang 1,2 , Wesley Gilson 2 , Klaus J. Kirchberg 3 , Joachim Hornegger 1 , Christine
Lorenz 2
1 Pattern Recognition Lab, Department of Computer Science, University of Erlangen-Nuremberg, Erlangen, Bavaria, Germany; 2 Center
for Applied Medical Imaging, Siemens Corporation, Corporate Research, Baltimore, MD, United States; 3 Center for Applied Medical
Imaging, Siemens Corporation, Princeton, NJ, United States
Percutaneous interventions involve the navigation of a needle or probe to a target location. MRI is well-suited to guide these procedures as it offers good soft
tissue target visualization and no ionizing radiation. High field wide bore MRI has stimulated interest in performing more of these procedures, but workflow
and procedure speed are significant hurdles for full adoption. Here, a navigation tool for guiding and tracking the needle in real-time under MRI is
presented.
1841. Navigated Liver Biopsies in a Closed-Bore MR Scanner: First Clinical Experience
Michael Moche 1 , Gregor Thörmer 1 , Nikita Garnov 1 , Jochen Fuchs 1 , Susann Heinig 1 , Tim Riedel 1 , Thomas
Kahn 1 , Harald Busse 1
1 Leipzig University Hospital, Leipzig, Germany
MRI has been shown to be of great clinical utility for the guidance of various procedures. In a closed-bore scanner, the simplest approach is to manipulate
the instrument outside the bore and move the patient inside for control imaging only. Potential benefits for percutaneous biopsies in the liver have been
investigated in 15 patients by using a flexible add-on navigation solution which even allowed interventions in obese patients. Real time navigation was
provided by following the virtual instrument on properly reformatted images of a 3D roadmap. In combination with a specific breathhold protocol, punctures
could be reliably performed in reasonable times.
1842. Evaluation of a Real Time MR-Guided Interactive Navigation Device: Phantom and Animal
Experiments
Steffi Valdeig 1 , Barry Fetics 2 , Li Pan, 1,3 , Clifford R. Weiss 1 , Erez Nevo 2 , Dara L. Kraitchman 1 , Frank K.
Wacker 1
1 Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 2 Robin Medical Inc.,
Baltimore, MD, United States; 3 Center for Applied Medical Imaging, Siemens Corporation, Corporate Research, Baltimore, MD,
United States
Purpose: To test the feasibility and accuracy of a tool that allows for interactive adjustments of the needle plane during a MR guided puncture Method:
Experiments were performed in vivo and in phantoms using a gradient based navigation system for real time MR guided punctures in a wide bore MR
imager. To assess for accuracy of the system the distance of the needle tip (virtual and real) to the target was determined on MR control scans. Result: The
mean 3D total error was 4.9 ±2.8mm in the phantom. The system error was less than 2 mm. In the animal, successful punctures of the target structures could
be confirmed in all punctures. Conclusion: The combination of image overlay with real time adjustment of the virtual needle and real-time imaging feedback
provides an accurate and intuitive means to perform percutaneous interventions in a wide bore MR imager.
1843. Fast and Precise: Real Time MR-Guided Prostate Biopsy at 3 Tesla in Animal Experiment.
Patrik Zamecnik 1 , Axel j. Krafft 2 , Florian Maier 3 , Jaane Rauschenberg 2 , Michael Bock 2
1 DKFZ German Cancer Research Center), Heidelberg, Baden-Württemberg, Germany; 2 DKFZ (German Cancer Research Center);
3 DKFZ (German Cancer Resaerch Center)
Real time MR-guided prostate biopsy at 3 Tesla in animal experiment proved to be a fast an precise method to perform prostate biopsies.
1844. Development of a Pneumatic Robot for MRI-Guided Transperineal Prostate Intervention
Sang Eun Song 1 , Nathan Bongjoon Cho 1 , Iulian Iordachita 2 , Gregory Scott Fischer 3 , Junichi Tokuda 4 ,
Nobuhito Hata 4 , Gabor Fichtinger 5 , Clare Tempany 4
1 Engineering Research Center, The Johns Hopkins University, Baltimore, MD, United States; 2 Department of Mechanical
Engineering, The Johns Hopkins University, Baltimore, MD, United States; 3 Mechanical Engineering Department, Worcester
Polytechnic Institute, Worchester, MA, United States; 4 Brigham and Women’s Hospital, Boston, MA, United States; 5 School of
Computing,, Queen’s University, Kingston, Ontario, Canada
As accurate needle positioning helps the prostate cancer detection and treatment, a number of MRI-compatible robots have been introduced. However,
problems exist due to the strong magnetic field and limited workspace. Pneumatic actuator has the minimum distraction in the environment. However, it has
poor controllability. To overcome the controllability problem, a simple external damping mechanism that can enhance accuracy was developed. Based on the
actuator mechanism and workflow optimized modular design approaches, a new pneumatically actuated 4-DOF parallel robot for MRI-guided prostate
intervention was developed. A preliminary evaluation was conducted with satisfying actuator average position error of 0.2mm.