ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

SCIENTIFIC SESSION
Acquisition & Detection Strategies in Molecular Imaging
 
Wednesday 24 April 2013
Room 355 EF  16:00 - 18:00 Moderators: Michael F. Tweedle, Patrick M. Winter

16:00 0559.   
New Approaches in B1-Mapping Compensation for in Vivo Quantitative 19F MR Molecular Imaging Using UTE BSSFP
Matthew J. Goette1, Todd A. Williams1, John S. Allen1, Jochen Keupp2, Gregory M. Lanza1, Samuel A. Wickline1, and Shelton D. Caruthers1
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.

 
16:12 0560.   Improving Contrast of Delta Relaxation Enhanced MR (DreMR) Imaging
Francisco M. Martinez-Santiesteban1, Yonathan Araya1, Chad Harris2, William B. Handler2, Blaine A. Chronik3,4, and Timothy J. Scholl1,4
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.

 
16:24 0561.   
A Novel Strategy to Track Short-Term Stem Cell Viability and Integration Using Diffusion-Activated MRI Contrast Agents in a Murine Model of Radiation-Induced Cognitive Dysfunction
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 Artemov1
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.

 
16:36 0562.   Real-Time MR Imaging of Stem Cell Delivery to the Central Nervous System of Small and Large Animal Models Using EPI
Miroslaw Janowski1,2, 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. Bulte1,8, and Piotr Walczak1,8
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.

 
16:48 0563.   Quantification of MRI Sensitivity for Monodisperse Microbubble-Based Contrast Agent to Measure Fluid Pressure Changes. -permission withheld
Amgad Alrwaili1, Martin Bencsik1, Robert Morris1, David Fairhurst1, Victoria Mundell1, Gareth Cave1, Jonathan McKendry2, and Stephen Evans2
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.

 
17:00 0564.   
Multi-Modality Imaging of Endothelial Progenitor Cells Mediates Neovascularization and Muscle Regeneration in Ischemia Muscle
Shenghong Ju1 and Xingui Peng2
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.

 
17:12 0565.   MRI Detection of Bacterial Infection Through Endogenous CEST Contrast
Guanshu Liu1,2, Yuan Qiao3, Chetan Bettegowda3, Verena Staedtke3, Kannie W.Y. Chan4,5, Renyuan Bai3, Gregory Riggins3, Kenneth W. Kinzler3, Jeff W.M. Bulte4,5, Michael T. McMahon1,2, Assaf A. Gilad4,5, Bert Vogelstein3, Shibin Zhou3, and Peter C.M. van Zijl1,2
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.

 
17:24 0566.   in vivo Detection of Membrane-Bound Radicals Using Molecular MRI and Immuno-Spin-Trapping in a Mouse Model for ALS
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 Hensley7
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.

 
17:36 0567.   
Complete Separation of Extra- And Intracellular Hyperpolarized 13C Metabolite Signal with Diffusion Weighted MR
Bertram L. Koelsch1, Kayvan R. Keshari2, Tom H. Peeters2, Peder E.Z. Larson1,2, David M. Wilson2, and John Kurhanewicz1,2
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.

 
17:48 0568.   Towards Early Detection of Pancreatic Cancers by CA 19-9 Conjugated Magnetic Nanoparticles and Active Feedback MRI -permission withheld
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 Lin1
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 patientsí 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.