Sathya Vijayakumar^1,2, Eugene G Kholmovski^1,2, Ravi Ranjan^2,3, Gaston Vergara^2,3, Joshua Blauer^2,4, Gene Payne^1,2, Nelly Volland^1,2, Kamal Vij⁵, Gregory Gardner^2,4, Peter Piferi⁵, Kimberly Johnson^2,3, Li Pan⁶, Klaus Kirchberg⁶, Rob MacLeod^2,4, Christopher J McGann^2,3, and Nassir F Marrouche^2,3
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, ²CARMA Center, University of Utah, Salt Lake City, Utah, United States,³Department of Cardiology, University of Utah, Salt Lake City, Utah, United States, ⁴SCI, University of Utah, Salt Lake City, Utah, United States, ⁵SurgiVision Inc., Irvine, California, United States, ⁶Center for Applied Medical Imaging, Siemens Corporate Research, Princeton, NJ

In this work, we study the feasibility of an EP-MRI workflow for RF ablation procedures for the treatment of atrial fibrillation. This approach consists of the assessment of ablation performed in the EP-suite using MRI, and completing the ablation procedure in the MRI-suite if necessary using real time MRI guidance. This work flow may possibly reduce the number of repeat ablation procedures.

Li Pan¹, Julien Barbot², Steven M. Shea¹, Sunil Patil¹, Klaus J. Kirchberg², Glenn Meredith², Tongbai Meng¹, Eugene G. Kholmovski^3,4, Sathya Vijayakumar^3,4, Kamal Vij⁵, Mike Guttman⁵, Peter G. Piferi⁵, Kimble L. Jenkins⁵, and Christine H. Lorenz^1
1Center for Applied Medical Imaging, Siemens Corporate Research, Baltimore, MD, United States, ²Center for Applied Medical Imaging, Siemens Corporate Research, Princeton, NJ, United States, ³UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, United States, ⁴CARMA Center, University of Utah, Salt Lake City, UT, United States, ⁵SurgiVision, Inc., Irvine, CA, United States

In this work, we present an integrated system that incorporates active device tracking implemented in an interactive real-time sequence as well as a graphical interface for real-time catheter visualization and navigation. The system supports tracking and visualization of multiple catheters and several options for automatically updating imaging planes. The tracking provided robust catheter location accuracy, and the visualization of the catheters provided the users with an environment similar as with X-ray fluoroscopy guided procedures. The system is especially suitable for MR guided intravascular interventions in which real-time catheter tracking and visualization for navigation is mandatory.

Christoph Kolbitsch¹, Claudia Prieto¹, Christian Buerger¹, Reza Razavi¹, Jouke Smink², and Tobias Schaeffter^1
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, ²Philips Healthcare, Best, Netherlands

Image-guided catheterisations are an important clinical tool for cardiovascular diseases. In order to increase the accuracy of the procedure with an additional MRI roadmap, a 3D high resolution scan and additional respiratory information are required. Here we present a method that records all the necessary information during a single whole-heart scan with a prospective respiratory resolved acquisition scheme. Moreover, an affine model to describe the breathing motion can be obtained from the same acquired data. Validation on volunteer data yielded a maximum target registration error of less than 3.4mm.

Steffen Weiss¹, Bernd David¹, Kai-Michael Luedeke¹, Oliver Lips¹, Daniel Wirtz¹, Sascha Krueger¹, Peter Koken¹, Ronald Holthuizen², Tobias Schaeffter³, Jas Gill³, and Reza Razavi^3
1Philips Research Laboratories, Hamburg, Germany, ²Philips Healthcare, Best, Netherlands, ³Division of Imaging Sciences, King's College, London, United Kingdom

Earlier work on an MR-RF ablation catheter has been complemented by adding a sensor to measure the temperature of the ablation electrode as in standard catheters but here connected via highly resistive wires. This provides much increased RF safety and compatibility with clinical RF generators. All wiring in the final prototype either dampens RF resonances by high resistance or avoids RF resonances by segmentation of long cables into short sections using transformers and switches. RF safety of the catheter is demonstrated by RF heating measurements, and all EP functions of the catheter are evaluated by various measurements including MR-guided ablation procedures.

Sherif G Nour¹, Daniel P. Hsu², Jamal J Derakhshan³, and Jonathan S Lewin^4
1Radiology, Emory University Hospital, Atlanta, GA, United States, ²Radiology, Case Medical Center, Cleveland, OH, ³Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ⁴Radiology, Johns Hopkins School of Medicine, Baltimore, MA, United States

Veno-lymphatic (slow-flow) vascular malformations typically present in children and young adults with various combinations of pain, localized dysfunction, and disfigurement. They may also bleed or result in fatal coagulopathy. The treatment is often challenging with high recurrence after surgery or traditional x-ray fluoroscopy guided sclerotherapy. This work describes our experience with 46 sclerotherapy procedures performed exclusively within a high-field interventional MRI suite, highlights the necessary technical aspects, demonstrates the safety features related to MRI guidance as compared to traditional x-ray guidance, and reports the long-term efficacy of these procedures as observed on extended follow-up durations of up to 36.1 months.

Raphael Duivenvoorden^1,2, Jun Tang¹, David Izquierdo-Garcia³, David P. Cormode¹, Eric S.G. Stroes², Edward A. Fisher⁴, Zahi A. Fayad^1,3, and Willem J.M. Mulder^1
1Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, New York, NY, United States, ²Vascular Medicine, Academic Medical Center, Amsterdam, NH, Netherlands, ³Radiology, Mount Sinai School of Medicine, New York, NY, United States, ⁴Department of Medicine, Division of Cardiology, New York University School of Medicine, New York, NY, United States

We hypothesized that targeted statin delivery to atherosclerotic plaque with a reconstituted high density lipoprotein (rHDL) nanoparticle can inhibit plaque inflammation and development more potently than oral statin therapy or rHDL infusion. We divided 48 apoE-KO mice in 3 equal groups that were either treated with oral simvastatin, rHDL infusion or our rHDL like nanoparticle loaded with simvastatin for 12 weeks. We performed MRI and histology measurements to quantify aortic atherosclerosis. We found that targeted statin delivery to atherosclerotic plaque with rHDL like nanoparticles showed considerably more efficacy in the treatment of atherosclerosis than oral statin therapy or rHDL infusion.

Dingxin Wang^1,2, Brian Jin³, Robert Lewandowski³, Robert Ryu³, Kent Sato³, Ann Ragin³, Laura Kulik⁴, Mary Mulcahy^5,6, Frank Miller³, Riad Salem^3,6, Andrew Larson^3,6, and Reed Omary^3,6
1Siemens Medical Solutions USA, Inc., Minneapolis, Minnesota, United States, ²Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States, ³Department of Radiology, Northwestern University, Chicago, Illinois, United States, ⁴Department of Hepatology, Northwestern University, Chicago, Illinois, United States, ⁵Department of Medicine, Northwestern University, Chicago, Illinois, United States, ⁶Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, United States

This study accessed the utility of quantitative Transcatheter Intraarterial Perfusion (TRIP)-MRI for predicting chemotherapy-lipiodol delivery during transcatheter arterial chemoembolization (TACE). The volumes of drug distribution in the tumors and liver as well as the selectivity of chemotherapy emulsion delivery to the tumors obtained from pre-TACE TRIP-MRI highly correlated with corresponding parameters seen on CT scans after TACE. These findings suggest that quantitative TRIP-MRI may have the potential to provide important spatial biodistribution information of subsequent drug delivery during liver-directed transarterial locoregional therapies with same catheter positioning.

Gerrit Hendrik van de Maat¹, Mattijs Elschot², Peter Roland Seevinck¹, Hendrik de Leeuw¹, H.W. de Jong², M.L. Smits², M.A. van den Bosch², M.G. Lam², B.A. Zonnenberg², A D van het Schip², J Frank Nijsen², and Chris J Bakker^1
1Image Sciences Institute, University Medical Center, Utrecht, Utrecht, Netherlands, ²Department of Radiology and Nuclear Medicine, University Medical Center, Utrecht, Netherlands

We report the first results of the detection and quantification of Holmium-166 loaded microspheres in patients with liver metastases that were treated within the framework of a clinical phase I study. HoMS concentration maps determined from T2* weighted data acquired using a multi gradient echo sequence show good correspondence with activity maps acquired with Single Photon Emission Computed Tomography (SPECT). The total amount of HoMS in the liver determined from the concentration maps was in good agreement with the total amount that was delivered to the liver. The HoMS were found to mainly accumulate at the tumor site.

Uta Wonneberger¹, Sascha Krüger², Daniel Wirtz², Christoph Leussler², Steffen Weiss², Kerstin Jungnickel¹, Matthias Ludewig¹, Jürgen Bunke³, Jens Ricke¹, and Frank Fischbach^1
1Klinik für Radiologie und Nuklearmedizin, Otto-von-Guericke-Universität Magdeburg, D-39120 Magdeburg, Germany, ²Imaging Systems and Intervention, Philips Research Europe, D-22335 Hamburg, Germany, ³Healthcare, Philips, D-22335 Hamburg, Germany

An actively tracked needle guidance tool, directly connected to the MR system, with respective MR system software modifications to allow for simple-to-use, fast and accurate scan plane controlling with inherent registration to the MRI coordinate system is presented for the use in clinical routine for needle interventions in freehand-technique with the physician practicing from inside the open MR-system. The hand-held device is equipped with a guide bar to automatically align the needle path with the device and with a thumb switch to perform fast, immediate 90° scan plane rotations around the needle axis without actual rotation of the device while simultaneously toggling between the two viewports of the real-time interactive scanner user interface.

David Arthur Woodrum¹, Jun Chen¹, Kevin J Glaser¹, Krzysztof Gorny¹, and Richard L Ehman^1
1Radiology, Mayo Clinic, Rochester, Minnesota, United States

A critical part of the tumor ablation is intra-treatment monitoring to determine whether an adequate treatment is achieved. Our hypothesis is MR elastography can be used to measure the changing stiffness of the ablation zone during and after the ablation. The purpose of this study is to demonstrate the feasibility of new acoustic path-thru driver at producing mechanical waves through a laser ablation applicator to the ablation zone. In vivo studies in porcine liver demonstrate that these waves can be produced and measured within the porcine liver. The stiffness at tip of laser applicator demonstrates increasing stiffness during the ablation.