TRADITIONAL POSTER - ismrm

Poster Sessions
imaging using Proton Imaging of Siloxanes to map Tissue Oxygenation Levels (PISTOL) technique. We now present in vitro data demonstrating the pO2
calibration curves of linear and cyclic siloxanes of different chain lengths as pO2 sensing reporter molecules for use in conjunction with PISTOL.
1884. Hyperpolarized 13 C MR Reporter Probe System with Acy-I Gene and [1- 13 C] N-Acetyl-L-Methionine
Albert P. Chen 1 , Ralph E. Hurd 2 , Yi-Ping Gu 3 , David M. Wilson 4 , Charles H. Cunningham 3
1 GE Healthcare, Toronto, ON, Canada; 2 GE Healthcare, Menlo Park, CA, United States; 3 Imaging Research, Sunnybrook Health
Sciences Centre, Toronto, ON, Canada; 4 Radiology, UCSF, San Francisco, CA, United States
With the recent development of techniques to achieve highly polarized nuclear spins states via dynamic nuclear polarization and retain the polarization in
solution, it may be feasible to utilize a suitable hyperpolarized 13 C substrate to target an enzyme reporter gene for non-invasive MR imaging of labeled
cells/tissue. In this study, a hyperpolarized 13 C MR reporter system is demonstrated in cells transfected to overexpress a reporter gene, aminoacylase I (Acy-
I), using pre-polarized [1- 13 C] N-acetyl-L-methionine as the reporter probe.
1885. In Vivo Detection of CFos-GFP for Neural Activation Via Magnetization Transfer Contrast (MTC)
Magnetic Resonance Imaging (MRI)
Carlos J. Perez-Torres 1,2 , Robia G. Pautler 1,2
1 Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, United
States; 2 Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, United States
cFos is a widely utilized marker of neuronal activation that currently requires ex vivo immunohistochemistry for detection. We believe detecting cFos
expression in vivo with MRI would provide an unparalleled means to assess neuronal activation in mouse models of human diseases. Importantly, the levels
of activation would be a direct measurement of neuronal function. . We have previously described a novel approach to detect Green Fluorescent Protein
(GFP) expression in vivo using Magnetization Transfer MRI. Here, we apply the MRI based detection of GFP to evaluate a cFos-GFP fusion model.
1886. Dual 1 H and 19 F MR LacZ Gene Reporter Molecule
Rami Robert Hallac 1 , Vikram D. Kodibagkar 1 , Jian-Xin Yu 1 , Ralph P. Mason 1
1 Radiology, UT Southwestern Medical Center at Dallas, Dallas, TX, United States
The detection of enzyme activity and gene expression in vivo is potentially important for the characterization of diseases and gene therapy. We demonstrate
the use of a novel class of dual 1H/19F NMR lacZ gene reporter molecule to identify £]-gal expressing tumors in mice. The substrate shows a single 19F
NMR signal and exposure to ƒÒ-galactosidase induces a large 19F NMR chemical shift response. The combination of Fe3+ and released aglycone product
generates intense T2 contrast only in £]-gal expressing tumor. The dual modality approach allows both the detection of substrate and imaging of product.
1887. Quantification of 3D T2*-Weighted MR Images Allows Evaluation of Different Viral Vectors for
Stable MR Reporter Gene Expression in the Rodent Brain
Greetje Vande Velde 1 , Janaki Raman Rangarajan 2 , Tom Dresselaers 1 , Jaan Toelen 3 , Zeger Debyser 3 ,
Veerle Baekelandt 3 , Uwe Himmelreich 1
1 Biomedical NMR unit/MoSAIC, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium; 2 Medical Imaging Research
Center/MoSAIC, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium; 3 Molecular Medicine, Katholieke Universiteit Leuven,
Leuven, Flanders, Belgium
Utilizing lentiviral (LV) and adeno-associated (AAV) viral vector systems for delivering MRI reporter genes (e.g. ferritin) will allow stable labeling and in
vivo visualization of marked cells, but their potential limitations for MRI are often insufficiently addressed. LV injection resulted in hypointense contrast at
the injection site on T2*-weighted MRI, partially explained by an immune response. Contrasting with LV, AAV injection resulted in little background
contrast and AAV-mediated MRI reporter overexpression resulted in significant contrast-to-background on T2*-weighted MRI. We developed an image
analysis pipeline that permits to quantitatively compare the hypointense contrast parameters of timeline scans or different experimental groups.
1888. Non-Invasive DNA Probe Delivery Enables MR Detection of Gene Up-Regulation Associated with
Psychostimulant Sensitization
Christina H. Liu 1 , Jia Q. Ren 1 , Charng-ming Liu 1 , Philip K. Liu 1
1 Radiology, Massachusetts General Hospital, Charlestown, MA, United States
Synopsis Intracerebroventricular infusion of therapeutics or MR contrast agents by lumbar or cortical puncture to the brains was the route of choice to
bypass the blood brain barrier (BBB) and to achieve uniform distribution. However, only limited number of delivery can be performed in the same subject,
therefore, has limited longitudinal applicability. Here we explore the feasibility of a non-invasive DNA-based MRI probe delivery route by intraperitoneal
injection with BBB bypass to assess gene up-regulation associated with chronic drug exposure.
1889. Remote MR Sensing of PH and Cell Viability Using LipoCEST-Filled Microcapsules
Kannie W. Y. Chan 1,2 , G. Liu 1,3 , D.R. Arifin 1,2 , J. W.M. Bulte 1,2 , M.T. McMahon 1,3
1 Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2 Cellular Imaging Section,
Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 3 F.M. Kirby Center for
Functional Brain Imaging, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
Cell transplantation is widely used for treatment of various diseases, with cell viability being key for successful therapy. Semi-permeable microcapsules have
been used to immunoprotect and visualize cell location, but not cell function. We demonstrate that LipoCEST-filled microcapsules can be used as a novel
way to monitor cell viability. CEST contrast is dependent on pH, which in itself is closely related to cell activity and functionality. Our pH-responsive
microcapsules showed a significant decrease in CEST signal when cell viability decreased at physiologically relevant pH’s, thus representing a useful noninvasive
tool to monitor successful cell therapy.