TRADITIONAL POSTER - ismrm

Poster Sessions
1708. Hyperammonemia and Edema: A DTI Study in the Adult Rat Brain
Nicolas Kunz 1,2 , Cristina Cudalbu 1 , Yohan Van de Looij 1,2 , Petra Hüppi 2 , Stephane Sizonenko 2 , Rolf
Gruetter 1,3
1 Laboratory of functional and metabolic imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland;
2 Division of Child Growth &Development, University of Geneva, Geneva, Switzerland; 3 Department of Radiology, University of
Geneva & Lausanne, Geneva & Lausanne, Switzerland
Ammonia is a neurotoxin that is implicated in the pathogenesis of hepatic encephalophaty, which is reported to be responsible for brain edema. It is not yet
clear whether brain edema is mostly vasogenic or cytotoxic. The aim of this study was to assess the effects of hyperammonemia on the rat brain by using
DTI at 9.4T. This study shows a rapid increase of the ventricle size during the three first hours of infusion along with a decrease in ADC. As the ventricle
size gets stabilized after 6h, the ADC keeps on decreasing, indicating the formation of mild cytotoxic edema.
1709. Comparison of ADC Values Using Pulsed Field Gradient and Correlation Time Diffusion Techniques
in a Murine Model of Steatohepatitis at 11.7T
Stephan William Anderson 1 , Jorge A. Soto 1 , Holly N. Milch 1 , Hernan Jara 1
1 Radiology, Boston University Medical Center, Boston, MA, United States
The purpose of this study was to compare the ADC values obtained using pulsed field gradient (PFG) and correlation time diffusion (CT-D) techniques in a
mouse model of steatohepatitis at 11.7T. C57BL/6 mice fed a methionine-deficient choline-deficient (MCD) diet to induce steatohepatitis were sacrificed
intermittently throughout this period for ex vivo liver imaging. A comparison of the parametric maps and whole sample histograms generated by the PFG
and CTD techniques shows excellent agreement between the two diffusion techniques. In all cases CT-D parametric maps had significantly higher SNR and
the histogram width was narrower than those generated using PFG technique.
Blood Flow in Animal Models
Hall B Tuesday 13:30-15:30
1710. Blood-Flow MRI of Non-Human Primate (Baboon) Retina
Hsiao-Ying Wey 1 , Jinqi Li 1 , Jiongjiong Wang 2 , Sung-Hong Park 1 , Timothy Q. Duong 1
1 Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, TX, United States; 2 Radiology, University of
Pennsylvania, Philadelphia, PA, United States
Quantitative blood flow measurement of the retina is critically important as many retinal diseases could perturb basal blood flow and blood flow responses to
stimulations. In this study, we developed and applied the pseudo-continuous ASL to improve ASL contrast, and systematically explored blood-flow MRI of
the retina in anesthetized baboon on a human clinical scanner. Anesthetized baboons were used to exclude movement artifacts such that we could focus on
evaluating hardware feasibility and imaging parameters for high-resolution quantitative BF imaging of the retina as a first step toward evaluating potential
human applications.
1711. Quantitative Measurement of Cerebral Blood Flow with High Sensitivity in Mice at 9.4T
Bing Wen Zheng 1 , Philip Lee 1 , Xavier Golay 1
1 Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, A*STAR (Agency for Science, Technology and Research),
Biopolis, Singapore
The aim of this study was to develop a practical and robust perfusion measurement with high sensitivity and stability in the mouse brain at high magnetic
field strength, via the combination of flow-sensitive alternating inversion recovery (FAIR) and single-shot k space-banded gradient- and spin-echo
(kbGRASE). To estimate the influence of physiological parameters on the precision and reproducibility of CBF measurements, changes in anesthesia
regime, hypercapnia and body temperature were performed.
1712. Non-Invasive MRI Measurement of CBF: Validating an Arterial Spin Labelling Sequence with
99mTc-HMPAO CBF Autoradiography in a Rat Stroke Model
Tracey Anne Baskerville 1 , Christopher McCabe 1 , Jim Patterson 2 , Juan Chavez 3 , I Mhairi Macrae 1 , William
M. Holmes 1
1 Glasgow Experimental MRI Centre, University of Glasgow, Glasgow, Lanarkshire, United Kingdom; 2 Institute of Neurological
Sciences, Southern General Hospital, Glasgow, United Kingdom; 3 Discovery Translational Medicine, Wyeth Research, Collegeville,
PA, United States
Arterial spin labelling (ASL) has provided some valuable insight into cerebral perfusion in stroke research. ASL has the advantages of being non-invasive,
allows repeated scanning in the same subject and can generate fully quantitative cerebral blood flow (CBF) measurements; however it requires further
validation in rodent stroke models. We modified a published ASL technique (Moffat et al, 2005) and validated it against an established autoradiographic
technique using the SPECT ligand, 99mTC-D, L-Hexamethylpropyleneamine (99mTc-HMPAO) in a rodent stroke model. We found that relative CBF
estimates in cerebral regions of interest generated from ASL and autoradiography were closely matched throught MCA territory and ASL was able to
accurately detect reductions in CBF in ischaemic tissue.
1713. Quantitative CBF MRI of Anesthetized Baboon Using Pseudo-Continuous ASL
Hsiao-Ying Wey 1,2 , Jinqi Li 1 , Lisa Jones 3 , M Michelle Leland 3 , C Akos Szabo 4 , Jiongjiong Wang 5 , Peter T.
Fox 1 , Timothy Q. Duong 1,2
1 Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, TX, United States; 2 Radiology, UT Health
Science Center at San Antonio, San Antonio, TX, United States; 3 Laboratory Animal Resources, UT Health Science Center at San