Room 355 EF

16:00 - 18:00

Moderators:

Michael F. Tweedle, Patrick M. Winter

Matthew J. Goette¹, Todd A. Williams¹, John S. Allen¹, Jochen Keupp², Gregory M. Lanza¹, Samuel A. Wickline¹, and Shelton D. Caruthers^1
1C-TRAIN, Washington University in St. Louis, St. Louis, MO, United States, ²Philips Research Europe, Hamburg, Germany

This study presents a strategy to more accurately quantify the sparse 19F signal from alpha-v-beta-3-integrin targeted perfluorocarbon nanoparticle emulsions with a 1H image-based Actual Flip Angle B1-mapping correction to the 19F and 1H images, acquired with a simultaneous dual-frequency ultra-short echo time balanced steady state free precession sequence, in an in vivo setting using a VX2 tumor model implanted into rabbits.

Francisco M. Martinez-Santiesteban¹, Yonathan Araya¹, Chad Harris², William B. Handler², Blaine A. Chronik^3,4, and Timothy J. Scholl^1,4
1Medical Biophysics, University of Western Ontario, London, Ontario, Canada, ²Physics and Astronomy, University of Western Ontario, London, Ontario, Canada, ³Physics and Astronomy, Western University, London, Ontario, Canada, ⁴Robarts Research Institute, University of Western Ontario, London, Ontario, Canada

Delta relaxation enhanced MR (dreMR) uses the change in relaxation rate of molecular probes, at different magnetic fields, as a source of contrast. This contrast is normally obtained subtracting magnitude MR images acquired at two different magnetic fields, and is highly susceptible to motion, edge artefacts, Eddy Currents, and magnetic field variations in B₀ or B₁. The proposed method reduces these problems and improves dreMR contrast by compensating phase differences between the source images and performing a complex subtraction.

Ethel Ngen¹, Lee Wang¹, Yoshinori Kato¹, Nishant Gandhi², Balaji Krishnamachary¹, Barbara Smith³, Wenlian Zhu¹, Micheal Armour², John Wong², Zaver M. Bhujwalla⁴, Katheleen Gabrielson⁵, and Dmitri Artemov^1
1Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ²Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ³Institute for Basic Biomedical Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ⁴Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, United States, ⁵Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States

Given the limited regenerative ability of the central nervous system, several stem cell-based therapies are currently being investigated to repair brain damage. In order to effectively manage these therapeutic regimes, there is a need for non-invasive and clinically translatable imaging strategies capable of tracking the engraftment and survival of transplanted stem cells with high resolutions. In this study, we non-invasively monitored the viability and homing of transplanted stem cells in mice, using a dual-labeled MRI contrast strategy. Furthermore, an image-guided radiation-induced murine model of cognitive dysfunction was developed to assess the efficiency of the MR activation strategy in vivo.

Miroslaw Janowski^1,2, Joanna Wojtkiewicz³, Adam Nowakowski², Aleksandra Habich³, Piotr Holak⁴, Hubert Matyjasik⁴, Dawn Ruben⁵, Jiadi Xu⁶, Sunil Patil⁷, Zbigniew Adamiak⁴, Monica S. Pearl¹, Philippe Gailloud¹, Barbara Lukomska², Wojciech Maksymowicz³, Jeff W.M. Bulte^1,8, and Piotr Walczak^1,8
1Rusell H. Morgan Dept. of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, United States, ²NeuroRepair Department, Mossakowski Medical Research Centre, Warsaw, Mazowsze, Poland, ³Department of Neurology and Neurosurgery, University of Warmia and Mazury, Olsztyn, Warmia and Mazury, Poland, ⁴Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Warmia and Mazury, Poland, ⁵Department of Molecular and Comparative Pathobiology, Johns Hopkins University, Baltimore, Maryland, United States, ⁶F. M. Kirby Research Center, Kennedy Krieger Institute, Baltimore, Maryland, United States, ⁷Center for Applied Medical Imaging, Siemens Corporate Research, Baltimore, Maryland, United States, ⁸Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, United States

There is a tremendous progress in manufacturing and in vitro characterization of stem cells, however the process of stem cell delivery remains a serious challenge. We report on a novel intraarterial stem cell delivery technique with real-time MR imaging of labeled cells using an EPI sequence. This ultrafast imaging technique provides information in real time on the distribution of cells during the procedure of cell infusion, enabling immediate intervention when cells engraft within an undesired location, or engraft excessively, giving rise to microembolisms. Our dynamic imaging technique should aid in enhancing the safety and efficacy of intraarterial cell delivery.

Amgad Alrwaili¹, Martin Bencsik¹, Robert Morris¹, David Fairhurst¹, Victoria Mundell¹, Gareth Cave¹, Jonathan McKendry², and Stephen Evans^2
1Physics and Mathematical Sciences, Nottingham Trent University, Nottingham, United Kingdom, ²School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom

Quantification of MRI Sensitivity for Monodisperse Microbubble-based Contrast Agent to Measure Fluid Pressure Changes.

Shenghong Ju¹ and Xingui Peng^2
1Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu, China, ²Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province, China

This paper was focus on the cell tracking by optical imaging and MRI in vivo and the therapeutic effect assessment of endothelial progenitor cells by MRI and histology.

Guanshu Liu^1,2, Yuan Qiao³, Chetan Bettegowda³, Verena Staedtke³, Kannie W.Y. Chan^4,5, Renyuan Bai³, Gregory Riggins³, Kenneth W. Kinzler³, Jeff W.M. Bulte^4,5, Michael T. McMahon^1,2, Assaf A. Gilad^4,5, Bert Vogelstein³, Shibin Zhou³, and Peter C.M. van Zijl^1,2
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, ²Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, ³Ludwig Center, Howard Hughes Medical Institute and Sidney Kimmel Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, United States,⁴Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, ⁵Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States

Currently there are no MRI methods to image bacterial infection. Here, we show that Chemical Exchange Saturation Transfer (CEST) provides a non-invasive MR imaging method to detect bacteria in live mice. Using this approach, we were able to detect two bacteria strains, C. novyi-NT and E. Coli, in vitro. As a first demonstration, we applied this approach to bacteriolytic therapy, which has recently emerged as a promising approach for treating cancer and is currently being translated to the clinic. The results show that CEST-MRI can monitor the infection of anaerobic bacteria in the hypoxic cores of solid tumors.

Rheal A. Towner¹, Nataliya Smith¹, Debra Saunders¹, Florea Luou², Robert Silasi-Mansat², Melinda West³, Dario C. Ramirez⁴, Sandra E. Gomez-Mejiba⁴, Marcelo G. Bonini⁵, Ronald P. Mason⁶, Marilyn I. Ehrenshaft⁶, and Kenneth Hensley^7
1Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States, ²Cardiovascular Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States, ³Free Radical Biology & Aging, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States, ⁴4Laboratory of Experimental Medicine & Therapeutics, National University of San Luis, San Luis, San Luis, Argentina, ⁵Medicine, Univ. of Illinois at Chicago, Chicago, IL, United States, ⁶Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States, ⁷Department of Pathology, University of Toledo Health Sciences Campus, Toledo, Ohio, United States

Free radicals play a major role in the pathogenesis of amyotrophic lateral sclerosis (ALS), a detrimental neuroinflammatory disease. We used a combination of targeted molecular MRI (mMRI) and immuno-spin-trapping (IST) to detect for the first time non-invasive in vivo spin-trapped membrane-bound radicals (MBR) in a mouse model for ALS. MBR are trapped by the spin trapping compound 5,5-dimethyl-pyrroline-N-oxide (DMPO). Using both mMRI and IST provides the advantage of in vivo image resolution and spatial differentiation of regional events in heterogeneous tissues or organs and the regional targeting of free radical mediated oxidation of cellular membrane components.

Bertram L. Koelsch¹, Kayvan R. Keshari², Tom H. Peeters², Peder E.Z. Larson^1,2, David M. Wilson², and John Kurhanewicz^1,2
1UC Berkeley - UCSF Graduate Program in Bioengineering, San Francisco, CA, United States, ²Dept. of Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States

Most commonly employed proton diffusion weighting MR techniques cannot measure rapid (sub-minute) changes in molecular motion and thus are limited in monitoring these highly dynamic processes. We previously combined diffusion weighting and hyperpolarized 13C techniques to rapidly (second) measure the translational motion of hyperpolarized metabolites. By exploiting the difference in extra- and intracellular molecular translational motion, we extend hyperpolarized 13C diffusion weighted MR to measure total and intracellular metabolite pools. The translation of this methodology can allow for the non-invasive assessment of intra and extracellular metabolite pools on the order of their generation.

Zhao Li¹, Chaohsiung Hsu², Chih-Wei Lai¹, Matthew Rochefort³, Yu-Hao Chen², James S. Tomlinson³, Lian-Pin Hwang², Vay Liang W. Go⁴, and Yung-Ya Lin^1
1Chemistry and Biochemistry, UCLA, Los Angeles, CA, United States, ²Chemistry, National Taiwan University, Taipei, Taiwan, ³Surgical Oncology, UCLA, Los Angeles, CA, United States, ⁴UCLA Center for Excellence in Pancreatic Diseases, UCLA, Los Angeles, CA, United States

Early detection of pancreatic cancers using enhanced MRI techniques increases not only the treatment options available, but also the patients’ survival rate. This can be achieved with antibody-conjugated superparamagnetic iron oxide (SPIO) nanoparticles capable of binding to early stage pancreatic cancer cells to improve imaging specificity and innovation methods that can sensitively detect SPIO to improve imaging sensitivity. The enhanced contrast from SPIO can then be used to visually assess the distribution and magnitude of SPIO-targeted tumor cells. In vivo subcutaneous and orthotopic xenografts mouse models validated the superior contrast/sensitivity and robustness of this approach towards early pancreatic cancers detection.