Traditional Posters: Interventional - ismrm

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.
1845. Development and Preliminary Evaluation of a MRI-Guided Transrectal Prostate
Intervention
Axel Krieger 1,2 , Sang Eun Song 3 , Nathan Bongjoon Cho 3 , Peter Guion 4 , Iulian
Iordachita 1 , Gabor Fichtinger 5 , Louis L. Whitcomb 1
1 Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD, United States;
2 Sentinelle Medical Inc., Toronto, Canada; 3 Engineering Research Center, The Johns Hopkins University,
Baltimore, MD, United States; 4 National Institute of Health, Bethesda, MD, United States; 5 School of
Computing,, Queen’s University, Kingston, Ontario, Canada
This paper reports the design, development and MRI compatibility evaluation of a transrectal prostate robot for MRI-guided
intervention. The robot employs an automated needle guide with the goal of increasing needle placement accuracy and reducing
interventional procedure times. The design of the robot, employing piezo-ceramic-motor actuated needle guide and manual needle
insertion, is reported. Results of a MRI compatibility study show no reduction of MRI image SNR with the motors disabled and a 40%