TRADITIONAL POSTER - ismrm

Poster Sessions
1926. T1 Mapping of the Heart with Cardio-Respiratory-Gated Look-Locker MRI Quantifies T1 Shortening
Due to Gd-Labeled Macrophage Infiltration After Acute Myocardial Infarction
Nivedita Naresh 1 , Moriel Vandsburger 1 , Alexander Klibanov, 12 , Patrick Antkowiak 1 , Yaqin Xu 1 , Brent A.
French 1,3 , Frederick H. Epstein 1,3
1 Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2 Division of Cardiovascular Medicine,
University of Virginia; 3 Department of Radiology, University of Virginia
Macrophages play the critical role of clearing necrotic debris in the wound healing response that follows myocardial infarction (MI). Two days after MI, we
labeled macrophages in vivo using intravenous liposomes containing gadolinium. On day 5 after MI, cardiorespiratory-gated (CRG) Look-Locker MRI of
the heart quantified T1 shortening of the infarct zone secondary to infiltration of the labeled macrophages. The T1 shortening effect was dependent upon the
dose of liposomes. Macrophage labeling with Gd-liposomes and T1-mapping with CRG Look-Locker imaging may prove useful for quantitative MRI of
post-MI macrophage infiltration in preclinical murine studies.
1927. Development and Validation of a Peptide-Vectorized Superparamagnetic Imaging Probe Designed for
the Detection of Inflammation in Atherosclerotic Plaque
Carmen Burtea 1 , Sophie Laurent 1 , Eric Lancelot 2 , Olivier Rousseaux 2 , Sébastien Ballet 2 , Coralie
Thirifays 1 , Marc Port 2 , Gérard Toubeau 3 , Luce Vander Elst 1 , Claire Corot 2 , Robert Nicolas Muller 1
1 General, Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons, Mons, Belgium;
2 Research Center, Guerbet, Aulnay-sous-Bois, France; 3 Laboratory of Histology, University of Mons, Mons, Belgium
A VCAM-1-targeted cyclic heptapeptide peptide was conjugated to USPIO (USPIO-R832), and VCAM-1 binding was first confirmed on HUVEC
stimulated with TNF-alpha. Subsequently, USPIO-R832 was evaluated by MRI at 4.7T on ApoE-KO mice, by using T2 and T2*-weighted imaging
sequences. The ability to bind to atherosclerotic plaque of this molecular imaging probe was furthermore corroborated by histochemistry. The control
imaging probe was represented by USPIO vectorized by a non-specific peptide (USPIO-NSP).
1928. Non Invasive Assessment of Plaque Progression in ApoE-/- Mice Using T2* Weighted and Positive
Contrast SGM-MRI
Marcus R. Makowski 1 , Gopal Varma, Christian Jansen, Andrea J. Wiethoff, Tobias Schaeffter, Mathias
Taupitz 2 , Rene M. Botnar
1 King’s College London, Division of Imaging Sciences, , London, United Kingdom; 2 Radiology, Charite –, Berlin, Germany
Macrophages have been identified as a contributor to plaque instability in atherosclerosis. The aim of this study was to noninvasively assess iron oxide
uptake at different stages of plaque development in the innominate artery of apoE-/- mice and to evaluate the effect of anti-inflammatory treatment using
T2* weighted and positive contrast susceptibility gradient mapping (SGM) MRI. Molecular alterations in plaque composition with regard to macrophage
content could be detected using iron oxide particles in combination with T2* weighted and SGM MRI. Anti-inflammatory treatment with statins resulted in a
smaller SGM signal and smaller signal voids on T2* weighted images.
1929. Target-Binding of Perfluoro-Carbon Nanoparticles Alters Optimal Imaging Parameters Using F-19
Molecular MRI: A Study Using Fast in Vitro Screening and in Vivo Tumor Models.
Jochen Keupp 1 , Anne H. Schmieder 2 , Samuel A. Wickline 2 , Gregory M. Lanza 2 , Shelton D. Caruthers 2
1 Philips Research Europe, Hamburg, Germany; 2 C-TRAIN, Washington University, St. Louis, MO, United States
Patient stratification using molecular MRI of angiogenesis could change standard of care in anti-angiogenic therapy. Previously, α ν β 3-integrin targeted
nanoparticles (NP) have been shown to detect and quantify angiogenesis in small-animal tumor models based on 19 F-MRI. These promising results using
Perfluoro-Crown-Ether labels are currently translated to more clinically-relevant Perfluoro-Octyl-Bromide (PFOB) NP. The complex spectral properties of
PFOB and the sensitivity to the target-binding process, as observed in this work, require a thorough optimization of imaging parameters on target. In vitro
optimization on fibrin clots and in vivo detection of angiogenesis-targeted NP in the vasculature of Vx2-tumor bearing rabbits by 19 F-MRI is demonstrated.
1930. In Vivo CEST-Based Molecular Imaging Using RGD-LipoCEST in U87 Mice Brain Tumor
Julien Flament 1 , Benjamin Marty 1 , Céline Giraudeau 1 , Sébastien Mériaux 1 , Julien Valette 1 , Christelle
Médina 2 , Caroline Robic 2 , Marc Port 2 , Franck Lethimonnier 1 , Gilles Bloch 1 , Denis Le Bihan 1 , Fawzi
Boumezbeur 1
1 NeuroSpin, I²BM, Commissariat à l'Energie Atomique, Gif-sur-Yvette, France; 2 Guerbet, Research Division, Roissy-Charles de
Gaulle, France
LipoCEST are a new class of contrast agents for CEST-MRI which provide a tremendous amplification factor and can be easily functionalized by grafting
specific peptide on their outer membrane in order to target pathology specific biomarker. We present our promising preliminary result to image αvβ3,
integrin expressed during tumor growth, with CEST-based MRI using RGD-LipoCEST contrast agents. It constitutes to our knowledge the first attempt
towards brain tumor detection using LipoCEST contrast agents in vivo.