ELECTRONIC POSTER - ismrm

14:30 3755. The Use of Cellular MRI and Magnetic Particles to Study Cancer Stem Cells
Emeline Julie Ribot 1 , Carmen Simedrea 2 , Patricia McGowan 2 , Ann Chambers 2 , Paula J.
Foster 1
1 Imaging Laboratories, Robarts Research Institute, London, Ontario, Canada; 2 Medical Biophysics, University
of Western Ontario, London, Ontario, Canada
In this abstract, we describe technology developed in our labs for tracking stem-like cancer cells (CSC), in a mouse model of breast
cancer metastasis to the brain, using MRI and magnetic particles. A human breast cancer cell line was sorted by flow cytometry into
two distinct populations: CD44high/CD24low and CD44low/CD24high, representing the CSC-like and non-CSC cells, respectively.
The sorted cell populations can be labeled efficiently and without toxicity with the iron agent MoldayION Rhodamine B. Labeled
CSC can be detected in vivo in images of the mouse brain after injection into the left ventricle of the heart in nude mice.
15:00 3756. Development of Cationic Gd(III) Chelate as Potential Tumor-Selective MRI
Contrast Agent
Chang-Tong Yang 1 , Cai-Xian Yong 1 , Chew-Yuan Tuang 2 , Young-Tae Chang 2 , Kai-
Hsiang Chuang 1
1 Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Agency for Science,Technology and
Research, Singapore, Singapore; 2 Laboratory of Bioimaging Probe Development, Singapore Bioimaging
Consortium, Agency for Science,Technology and Research, Singapore, Singapore
We developed a new Gd(III) chelate by conjugating GdDO3A with 2-(diphenylphosphoryl)ethyldiphenylphosphonium cation --
Gd(DO3A-xy-TPEP)+ to form a cationic MRI contrast agent. This contrast agent has been synthesized and characterized in vitro and
in vivo. In vitro cell viability showed insignificant cytotoxicity at low [Gd] concentrations up to 0.2 mM. The in vitro T1 relaxivity
measured at 7.0 T is about 50% higher than that of clinically used Gd-DTPA and Gd-DOTA. In vivo imaging study in mice
demonstrated longer tissue retention especially in the liver. It indicated that Gd(DO3A-xy-TPEP)+ could potentially be used to detect
tumor which generally has larger negative mitochondrial transmembrane potential.
Human MRA
Hall B Monday 14:00-16:00 Computer 41
14:00 3757. Clinical Evaluation of Peripheral Vascular Disease Using a Hybrid Approach:
Unenhanced Quiescent Interval Single Shot and Low-Dose TWIST MR Angiography
Philip Anthony Hodnett 1,2 , Ioannis Kokztzoglou 3 , Timothy Scanlon, Jeremy Collins 4 , John
Sheehan, Eugene Dunkle, James C. Carr, Robert Edelman
1 Northwestern University, Chicago, IL, United States; 2 Northshore University Healthcare System, Chicago, IL,
United States; 3 Northshore University Healthcare System, United States; 4 Northwestern University, United
States
Imtroduction:The purpose of this study was to test the hypothesis that a hybrid technique employing a new unenhanced MRA
technique, quiescent interval single shot (QISS) in combination with a low-dose time resolved (TWIST)of the calf provides
comparable diagnostic accuracy to the standard hybrid approach using low-dose TWIST of the calf and high-dose stepping table CE-
MRA. Materials and Methods:20 prospective patients referred for evaluation of peripheral arterial disease underwent unenhanced and
combined low-dose time-resolved (TWIST)evaluation followed by standard hybrid stepping table bolus chase MRA. Results:The
combined unenhanced QISS technique and low-dose time resolved (TWIST ) calf study resulted in an overall sensitivity of 97.4%,
specificity of 98.3%, a negative predictive value of 98.7% and a positive predictive value of 96.7% using CE-MRA as the reference
standard. Cohen kappa analysis for inter-rater indicates almost perfect agreement (©§= 0.86) between the hybrid approach of
unenhanced QISS and TWIST and standard hybrid CE-MRA. Conclusion: This hybrid strategy permits a dramatic reduction in
contrast agent dosage with no loss of diagnostic accuracy.
14:30 3758. "Does Higher R1 Relaxivity Transfer in Improved Vessel Enhancement of the Run-
Off Vasculature?" - Evaluation of Macrocylic Gadolinium Chelates for Peripheral MR-
Angiography at 3 T by an Inter-Individual Comparison of Gadobutrol Vs Gadoterate
Meglumine, Bo
Ulrike I. Attenberger 1 , Matthias Voth 2 , Andre Luckscheiter 3 , Stefan Haneder 1 , Stefan O.
Schoenberg 4 , Henrik J. Michaely 1
1 Department of Clinical Radiology and Nuclear Medicine, University Medical Center Manheim, Mannheim,
Germany; 2 Bayer Schering AG, Berlin, Germany; 3 University of Heidelberg, Heidelberg, Germany;
4 Department of Clinical Radiology and Nuclear Medicine, University Medical Center Manheim , Mannheim,
Germany
Since nephrogenic systemic fibrosis (NSF) has been linked to gadolinium-chelate administration in patients with impaired renal
function, contrast agent dose and chelate stability have attracted broad attention. Numerous studies have demonstrated linear
compounds to be the least stable, whereas the macrocyclic compounds are the most stable. With the approval of gadobutrol, a double
concentrated macrocyclic gadolinium chelate became available, characterized by the highest R1-relaxivity among the macrocyclic
gadolinium chelates. The aim of this study was to evaluate the enhancement characteristics of gadobutrol and gadoterate meglumine,
both injected at a dose level of 0.07 mmol/kg BW, for peripheral MR-angiography.