Electronic poster

Tuesday 13:30-15:30 Computer 70

13:30 4218. Transition to MRI – Guided Interventions: First Multimodal Embolization Particles Being Visible in MRI and X-Ray/CT

Sönke H. Bartling¹, Johannes Budjan¹, Hagit Aviv², Henrik J. Michaely¹, Wolfhard Semmler³, Stefan O. Schönberg¹, Steffen Diehl¹, Shlomo Margel², Maliha Sadick<sup>1

1</sup>Clinical Radiology and Nuclear Medicine, University Medical Center, Mannheim, Baden-Württemberg, Germany; ²Dept. of Chemistry, Bar-Ilan University, Ramat-Gan, Israel; ³Dept. of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany

MRI guidance of interventions is a goal. Current embolization particles cannot be detected by an imaging modality (clinical) or only by CT/X-ray (research). Here, we developed and tested the first multimodal embolization particles being visible within MRI and CT/x-ray. An animal model was used. Post embolization imaging confirmed dual-modality contrast as embolized areas could be detected by CT and MRI. Histology confirmed results. The particles consist of two clinically approved substances: polymerized Iodine and USPIO. Once introduced into clinical routine, improvements of embolization therapy can be expected, because both CT and MRI could be used for treatment control.

14:00 4219. On the Effect of Contrast Agent Internalization in a Two Compartment Diffusion Model

Thomas Kampf¹, Christian Herbert Ziener¹, Peter Michael Jakob^1,2, Wolfgang Rudolf Bauer<sup>3

1</sup>Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany; ²Research Center for Magnetic Resonance Bavaria (MRB), Wuerzburg, Bavaria, Germany; ³Medical Clinic and Polyclinic 1, University of Wuerzburg, Wuerzburg, Bavaria, Germany

Contrast agents (CA) are commonly used to alter the contrast in MR data. Thus, profound knowledge of the CAs influence on the MR signal is important. In this work the effect of CA internalization is studied numerically. The simulations show that the simple linear relationship between the concentration of the CA and the relaxation rate is not preserved if the CA is internalized in a small part of the volume. This leads to a decreased apparent relaxivity. Furthermore an upper limit for the averaged relaxation rate was observed for a given volume fraction and size of the CA containing compartment.

14:30 4220. Prolonged and Homogenous Delivery of Gd Chelates to the Rat Brain with an Osmotic Pump

Paul A. Schornack<sup>1

1</sup>Radiology, University of Pittsburgh, Pittsburgh, PA, United States

The purpose of this study is to demonstrate the very prolonged, chronic delivery of neutral & negatively charged Gd-chelates, in addition to the positively charged Mn2+ ion, directly to rat brain interstitium by direct infusion into CSF of the lateral ventricles using an osmostic pump. The main goal of this work is to develop a framework for delivering molecular imaging agents of interest, such as pH reporting agents, to the brain in a consistent & predictable manner.

15:00 4221. Indirect Sensitive MR Detection of Aβ Plaques with USPIO in Alzheimer Transgenic Mice

Jean-Sebastien Raynaud¹, Gaelle Louin¹, Olivier Rousseaux¹, Isabelle Raynal¹, Claire Corot<sup>1

1</sup>Research, Guerbet, Roissy CdG Cedex, France

The aim was to evaluate the potentiality of an USPIO to increase the sensitivity to indirectly detect, via microglial phagocytic activity, Ab plaques, in Alzheimer transgenic mice. P904-Rhodamine was iv administrated in trangenic mice. MRI was performed at 2.35T and 7T. Microglia (CD45), iron (Perl's), Ab (Congo Red) and Rhodamine were analyzed on histological slices. Post P904 injection, several susceptibility artefacts were observed as focal spots all over the mouse brain. Iron, microglia, amyloid plaques et fluorescence were colocalized. These results suggest that P904 could be a very sensitive tool for Alzheimer disease diagnostic and prognostic.

Wednesday 13:30-15:30 Computer 70

13:30 4222. Gadolinium-Stained Brains Reveal Amyloid Plaques in Live Alzheimer's Transgenic Mice

Alexandra Petiet^1,2, Anne Bertrand^2,3, Christopher J. Wiggins³, Fanny Petit², Diane Houitte², Thomas Debeir¹, Thomas Rooney¹, Philippe Hantraye², Marc Dhenain<sup>2,3

1</sup>CNS, sanofi-aventis, Vitry-sur-Seine, France; ²MIRCen, CEA-CNRS URA 2210, Fontenay-aux-Roses, France; ³DSV/I2BM/Neurospin, CEA, Gif-sur-Yvette, France

Beta-amyloid (Aβ) plaques, one of the hallmarks of Alzheimer's disease (AD), are the targets of many pharmacological trials. MRI can be used to image these microscopic lesions (50–200μm) in mouse models but their in vivo detection is very challenging. We propose here a protocol based on the use of a gadolinium contrast agent injected directly in the brain of live mice to detect amyloid plaques. We show that Aβ plaques can be identified in APP/PS1 mice aged from 6 to 20 months and that the plaque load measured with MR correlates with histological measurements.

14:00 4223. Targeting of Tumor Cells with Glutamine Containing Carriers

Simonetta Geninatti-Crich¹, Rachele Stefania¹, Lorenzo Tei², Alessandro Barge¹, Ibolya Szabo¹, Stefania Lanzardo¹, Carlotta Bianco¹, Silvio Aime<sup>1

1</sup>University of Torino, Torino, Italy; ²University of piemonte orientale, Alessandria, Italy

Efficient routes to accumulate imaging probes in tumor cells may be found by exploiting the up-regulation of trans-membrane transporting systems. In fact, rapidly growing tumors require an increased and continuous supply of aminoacids and other nutrients. Glutamine appears an interesting candidate as it is considered the main source of nitrogen for tumor cells. Thus tumor cells have been targeted with MR imaging probes bearing glutamine residues as targeting vectors.

14:30 4224. ¹⁹F MRI of Trifluoroacetic Acid Encapsulated Into Liposomes

Mirko Meißner¹, Germaine Loredana Truisi², Constantin von zur Mühlen², Gerhard Pütz³, Dominik von Elverfeldt<sup>1

1</sup>Dept. of Diagnostic Radiology / Medical Physics, University Hospital Freiburg, Freiburg, Germany; ²Dept. of Cardiology and Angiology, University Hospital Freiburg, Freiburg, Germany; ³Dept. of Clinical Chemistry, University Hospital Freiburg, Freiburg, Germany

Gd-liposomes had been synthesized with a novel dual asymmetric centrifugation technique. Using MRI we examined the in vitro T₁-Relaxivity at 9.4 T and could show the influence of the internal Gd-concentration on the in vitro relaxivity of liposome encapsulated Gd-DTPA.

15:00 4225. Fluorinated Contrast Agents with Cation Depending T1 Sensitivity

Markus Plaumann¹, Dieter Leibfritz<sup>1

1</sup>Institute of Organic Chemistry, University of Bremen, Bremen, Germany

The synthesis of metal ion sensitive MR-contrast agents is important for many medical studies, i.e. neuronal processes. Eight fluorinated Gd³⁺ complexes were synthesized to study the effect of different metal ions to the relaxation time. ¹H-T₁ measurements of the synthesized complexes show a strong dependence of relaxivity in presence of diamagnetic metal ions (i.e. Na⁺, K⁺, Ca²⁺, Mg²⁺) and additionally Mⁿ⁺-concentration. Furthermore, relaxation times depend on temperature and pH-value. The molecular structure and length of the side chain of the synthesized complexes is very important for sensitivity to metal ions and changes in T₁ times.

Thursday 13:30-15:30 Computer 70

13:30 4226. Positive Contrast and Quantitative Imaging of Magnetic Nanoparticles and Cancer Cells with Biomarker Targeted RGD-Nanoparticle Conjugates Using T₁ Weighted Ultrashort Echo Time (UTE) Imaging

Xiaodong Zhong¹, Longjiang Zhang^2,3, Liya Wang², Hongwei Chen², Julie Yeh², Andrew Wang⁴, Hui Mao<sup>2

1</sup>MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States; ²Department of Radiology, Center for Systems Imaging, Emory University, Atlanta, GA, United States; ³Department of Radiology, Jinling Hospital, Nanjing University College of Clinical Medicine, Nanjing, Jiangsu, China; ⁴Ocean NanoTech, LLC, Springdale, AR, United States

Negative contrast of magnetic nanoparticles (MNPs) on conventional T₂ weighted images may suffer from poor contrast to noise ratio (CNR). This study demonstrated that positive T₁ contrast from MNPs can be obtained using ultrashort echo time (UTE) imaging, resulting higher CNR than that of conventional T₂ weighted imaging. Signal intensity of MNPs in UTE images has a linear correlation with core size and concentration of MNPs used in this study. Cell imaging with the UTE method also demonstrated potential applications of UTE imaging of biomarker targeted MNPs with contrast enhancement associated to the binding of cell targeted MNP.

14:00 4227. MR Lymphography with Fe3O4 Nanoparticles in Rabbits: In Vivo Investigation of Metabolism of Fe3O4 Nanoprobes

Rong Rong¹, Wang Ruixue², Wang Xiaoying¹, Zhang Jue², Song Yujun<sup>2

1</sup>Department of Radiology, 1st Hospital of Peking University, Beijing, China; ²Department of Biomedicine, Peking University, Beijing, China

The metabolism of magnetic nanoprobes for MRI was investigated in vivo in order to determinate optimized diagnosis time for the most contrast imaging and to discover nidus. After injection of these nanoprobes into rabbits, a significant darkening effect on the liver epithelial net lymph tissue was observed in 20 min, with about 20% reduce of the spin-spin relaxation time T2. The metabolism study on these nanoparticles indicated that they did not show any weak toxicity to organs detected and finally entered into the hematopoietic organ ¨C spleen without obvious retention in any related organs after recycling for 3 days.

14:30 4228. Ultrasmall Particle of Iron Oxide – RGD Peptidomimetic Conjugate as Novel MRI Contrast Agent

Sophie Laurent¹, Carmen Burtéa¹, Vincent Rerat², Jacqueline Marchand-Brynaert², Luce Vander Elst¹, Robert N. Muller<sup>1

1</sup>Université de Mons, Mons, Belgium; ²Université catholique de Louvain, Louvain-la-Neuve , Belgium

In this work, we describe the grafting of a home-made RGD peptidomimetic on ultrasmall particles of iron oxide (USPIO) coated with 3,3’-bis(phosphonate)propionic acid, and the determination of the grafting rates by X-ray photoelectron spectroscopy (XPS). The USPIO-g-Mimic have been characterized by photon correlation spectroscopy (PCS); their magnetometric and relaxometric profiles, and their capacity to target leukemic cells were also analyzed.

15:00 4229. Cracked Iron Oxide Nanoprticles as T2 Contrast Agents for Magnetic Resonance Imaging

Sung Lan Jeon¹, Min Kyung Chae, Eun Ju Jang, Jee-Hyun Cho, Kwan Soo Hong, Gyunggoo Cho, Chulhyun Lee

¹Korea Basic Science Institute, Cheongwon-gun, Chungcheongbuk-do, Korea, Republic of

Nanoparticles with small size and large surface provide magnetic resonance image with high sensitivity and specificity at low imaging-agent concentration. Metal oxide nanoparticles with hollow spheres can incorporate therapeutic agents into their payloads, enabling simultaneous MRI diagnosis and delivery of drugs to targeted sites. Herein, we report a facile synthesis of nontoxic cracked iron oxide nanoparticles (CIONPs) from hydrophobic FeO nanoparticles (HIONPs) via 3 steps. With complex surface structure, CIONPs showed improved r2 relaxivities compared to hydrophobic FeO nanoparticles (HIONPs). We expect that CIONPs have the potential application as a drug or chemical delivery vehicle because of their cracked spheres. In addition, cellular and in vivo MR imaging study with CIONPs will be tested.

Advanced Imaging of Spine

Hall B Monday 14:00-16:00 Computer 71

14:00 4230. Magnetization Transfer MRI Measurements of Cervical Spinal Cord Abnormalities in Patients with Neuromyelitis Optica

Mina Kim¹, Aaron Chan¹, Henry Mak¹, Queenie Chan², Koon Ho Chan<sup>3

1</sup>Department of Diagnostic Radiology, The University of Hong Kong, Pokfulam, Hong Kong, China; ²Philips Healthcare, Hong Kong; ³Department of Medicine, The University of Hong Kong, Hong Kong

Diagnosing neuromyelitis optica (NMO) in the early stages is crucial in order to provide the proper treatment as it involves aggressive and severe attacks of blindness and paralysis. However, current diagnostic criteria in routine practice using conventional techniques are not sensitive to early abnormalities in NMO. In the present work, we conducted magnetization transfer (MT) imaging for NMO patients. Our results show that it is feasible to assess NMO cervical cord damage of normal appearing tissues using the quantitative capability of MT imaging, which may lead to a better understanding of the clinical manifestations in NMO.

14:30 4231. Diffusional Kurtosis Imaging of the Cervical Spinal Cord in Multiple Sclerosis Patients

Maxim Bester^1,2, Eric Sigmund¹, Ali Tabesh¹, Hina Jaggi¹, Matilde Inglese^3,4, Robin Mitnick<sup>1

1</sup>Radiology, New York University, New York, NY, United States; ²Neuroradiology, Eppendorf-Hamburg University, Hamburg, Germany; ³Radiology , New York University, New York, NY, United States; ⁴Neurology, New York University, New York, NY, United States

Spinal cord (SC) is a frequent and clinically relevant site of pathology in multiple sclerosis (MS). Diffusion kurtosis imaging (DKI) measures non-Gaussian water diffusion and DKI-derived mean kurtosis (MK) is an index of tissue microstructural complexity. Using a moderately expanded diffusion sampling scheme, MK can be obtained simultaneously with DTI metrics. The aim of this study was to investigate global and regional structural abnormalities in the cervical SC of MS patients using both DKI and DTI. Compared to controls, fractional anisotropy and MK were significantly decreased and mean diffusivity was increased in patients. MK was significantly associated to disability.

15:00 4232. Radial Fractional Anisotropy Mean and Radial Mean Diffusivity Mean: New Metric in the Study of Spinal Cord Tissue

Arturo Cardenas-Blanco^1,2, Eve Chung Tsai<sup>3,4

1</sup>Radiology, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; ²Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada; ³Neurosurgery, The Ottawa Hospital, Ottawa, Ontario, Canada; ⁴Cellular and Molecular medicine, University of Ottawa, Ottawa, Ontario, Canada

Diffusion Tensor Imaging (DTI) and its ability to delineate the motion of water molecules and subsequently white matter tracts has become more important during the last years in the study of spinal cord. Nevertheless, due to the lack of resolution and the poor signal to noise ratio, it is still one of the big challenges in clinical MR research. In this abstract a new approach to quantitatively assess SC tissue is presented. This new approach is based in the combination of quantitative information obtained from DTI; Fractional Anisotropy (FA) and Mean Diffusivity (MD); taking advantage of the singular geometry of the SC.

15:30 4233. T1 and T2 Mapping of the Human Cervical Spinal Cord at 3 Tesla

Maxim Bester^1,2, Matilde Inglese¹, Lazar Fleysher<sup>1

1</sup>Radiology and Neurology, New York University, New York, NY, United States; ²Eppendorf-Hamburg University, Hamburg, Germany

The cervical spinal cord (SC) is a frequent site of pathology in several neurological diseases. We measured the T1 and T2 relaxation times of the human SC using a 3-point GRE T1 mapping method with built-in B1-correction and spin-echo sequence with protocol optimization based on 2-point measurements of T2s respectively. The T1 relaxation times measured in our study were lower and the T2 relaxation values were higher than those reported previously. The latter might be explained by the fact that undesired diffusion weighting may be introduced by use of the TSE sequence leading to a decrease in T2 values.

Tuesday 13:30-15:30 Computer 71

13:30 4234. Novel Assessment of the Effects of Spinal Cord Injury in Patients by Means of Spinal FMRI

Patrick W. Stroman^1,2, Randi L. Beazer¹, Christopher Kidd¹, Rachael Bosma¹, Karen Smith^3,4, Ronald Pokrupa^5,6, Omar Islam, ^2,7, Nomusa Mngoma⁴, David Cadotte^8,9, David Mikulis^8,10, Michael G. Fehlings<sup>8,9

1</sup>Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada; ²Diagnostic Radiology, Queen's University, Kingston, Ontario, Canada; ³Physical Medicine and Rehabilitation, Queen's University, Kingston, Ontario, Canada; ⁴Providence Care, St Mary's of the Lake, Kingston, Ontario, Canada; ⁵Neurosurgery, Kingston General Hospital, Kingston, Ontario, Canada; ⁶Neurosurgery, Queen's University, Kingston, Ontario, Canada; ⁷Radiology, Kingston General Hospital, Kingston, Ontario, Canada; ⁸Neurosurgery, University of Toronto, Toronto, Ontario, Canada; ⁹Surgery, Toronto Western Hospital, Toronto, Ontario, Canada; ¹⁰Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada

Clinical applications of functional MRI of the spinal cord, in order to assess the effects of spinal cord trauma or disease, must provide sensitive and reliable results, even in the presence of fixation devices to stabilize the spine, and must meet practical time limitations while providing enough information to be diagnostic. Here we demonstrate detailed functional maps in response to stimulation on the right and left sides of the body, at spinal cord segmental levels above and below the level of injury, in spinal cord injured patients. The method is almost fully automated, and takes under 7 minutes.

14:00 4235. High-Resolution CINE MRI for the Visualization of Arachnoid Adhesions

Andreas Gottschalk¹, Axel Bornstedt², Uwe Maurer³, Silke Steinhoff¹, Bernd Schmitz⁴, Volker Rasche<sup>2

1</sup>Department of Radiology, Armed Forces Hospital, Ulm, Germany; ²Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany; ³Department of Neurosurgery, Armed Forces Hospital, Ulm, Germany; ⁴Department for Diagnostic and Interventional Radiology, University Hospital Ulm, Ulm, Baden Wuerttemberg, Germany

The application of high-resolution cardiac phase resolved MRI (CINE) to directly visualize arachnoid adhesions for improved intervention planning in syringomyelia was investigated. It could be shown that high-spatial resolution (250µmx500µmx2mm) combined with 30 cardiac phases enabled direct visualization and quantification of the arachnoid adhesions. The position of the adhesions was verified during the intervention and post-interventional MRI was performed for assessment of the structure of the arachnoid adhesion after the microsurgical adhesiolysis procedure.

14:30 4236. Preoperation MRI Analysis in 149 Patients with Adolescent Idiopathic Scoliosis

Zhengguang Chen¹, Lifeng Lao², Jianxiong Shen³, Xiaozhen Li<sup>4

1</sup>Department of Radiology, First Hospital of Tsinghua University, Beijing, China; ²Department of Orthopaedic, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China; ³Department of Orthopedics, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China; ⁴Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China

Adolescent Idiopathic Scoliosis (AIS) is defined as a lateral spinal curvature greater than 10° accompanied by vertebral rotation and has no clear underlying causes. Traditionally AIS was evaluated using standing radiographs of the full spine to assess lateral curvature with the Cobb method, but it is on 2D coronal plane-only evaluating system, ignoring the 3D nature of AIS. MRI and computer-generated 3D images is a noninvasive procedure which could be used to assess the functional morphology in spine. To validate the hypothesis of disproportional growth between neural and skeletal system a MRI study was performed in 149 AIS patients and 41 age-matched controls.

15:00 4237. Mean Displacement Map of Spine and Spinal Cord Disorders Using High B-Value Q-Space Imaging; Feasibility Study.

Masaaki Hori^1,2, Utaro Motosugi¹, Fatima Zareen¹, Keiichi Ishigame¹, Hiroshi Kumagai¹, Toshiyuki Onodera³, Kazuo Yagi³, Shigeki Aoki², Tsutomu Araki<sup>1

1</sup>Radiology, University of Yamanashi, Chuou, Yamanashi, Japan; ²Radiology, School of Medicine, Juntendo University, Bunkyo, Tokyo, Japan; ³Tokyo Metropolitan University, Tokyo, Japan

Purpose of this study is to investigate the use of high b-value q-space imaging (QSI) to evaluate spine and spinal cord lesions in vivo, with the use of mean displacement (MD) maps, as feasibility study. In results, various MD values were measured in the lesions. Moreover, MD maps were not apparently well correlated with corresponding apparent diffusion coefficient maps of DWI with b-values of 1000 s/mm2. This technique has potential to provide new information in addition to conventional sequences in routine clinical study.