Non-Proton MRI
Thursday 23 April 2009
Room 315 10:30-12:30


Navin Bansal and Christian Beaulieu

10:30 609. Non-Invasive, Whole-Brain CMRO2 Mapping of the Human Brain
    Ian C. Atkinson1, Keith R. Thulborn1
Center for MR Research, University of Illinois at Chicago, Chicago, IL, USA
    An MR-based technique for whole-brain CMRO2 mapping is introduced and demonstrated in the human brain. This new approach incorporates a biologically based model of metabolic water production and persistence and accounts for brain tissue mass. Unlike positron emission tomography based CMRO2 approaches, this new technique allows CMRO2 maps to be obtained from humans without radioactive tracers or invasive measurements.
10:42 610. Performance of Hyperpolarized 1,4-13C2 Fumarate in a Murine Lymphoma Model in Vivo, a New Diagnostic Agent for Oncology

Pernille Rose Jensen1, Rene in 't Zandt1, Magnus Karlsson1, Anna Gisselsson1, Georg Hansson1, Mathilde Hauge Lerche1
Imagnia AB, Malmö, Sweden

    We have developed hyperpolarized 1,4-13C2 fumarate as a new promising metabolic marker for oncology. Metabolic parameters like up-take and conversion significantly influences imaging parameters like timing and concentration. Here we show a comparison between two substrates, hyperpolarized 1-13C pyruvate, which previously has been shown to be an oncology marker1, and the new agent, 1,4-13C2 fumarate. In a mouse EL-4 lymphoma model, the optimal timing and concentration are determined after which the SNR and contrast for the two substrates in the metabolic images are evaluated and compared.
10:54 611. Dual Resolution Simultaneous 19F/1H In Vivo Imaging of Targeted Nanoparticles
    Jürgen Rahmer1, Jochen Keupp1, Shelton D. Caruthers2,3, Oliver Lips1, Todd A. Williams3, Samuel A. Wickline3, Gregory M. Lanza3
Philips Research Europe, Hamburg, Germany; 2Philips Healthcare, Andover, MA, USA; 3Washington University, St. Louis, MO, USA
    19F-labeled diagnostic or therapeutic agents, like targeted perfluorocarbon nanoparticles, offer a high potential for quantified molecular MRI with excellent specificity. For anatomical co-registration of the fluorine signal, a proton image of the morphology is needed. Simultaneous 19F/1H imaging was shown to be an ideal approach to timeefficient recording of molecular information and morphology. An unmet need of truly simultaneous imaging is to satisfy the substantially different requirements on sensitivity and resolution between the 19F and 1H acquisition, while being constrained to a single choice of gradient strengths. This work presents in vivo results of angiogenesis-targeted imaging of Vx-2 tumors in rabbits, demonstrating that 3D radial simultaneous acquisition offers an SNR-efficient way to acquire 19F and 1H images at different resolutions at the same time. The basic principle is to modify the weight applied to samples in the gridding reconstruction.
11:06 612. Sodium and Proton Diffusion MRI of Rodent Glioma Therapy at 21 T
    Victor D. Schepkin1, Cathy W. Levenson2, Silvia M. Figueiroa3, William W. Brey1, Peter L. Gor'kov1, Kiran K. Shetty1
CIMAR, NHMFL/FSU, Tallahassee, FL, USA; 2College of Medicine, Florida State University, Tallahassee, FL, USA; 3College of Human Sciences, Florida State University, Tallahassee, FL, USA
    Rodent glioma chemotherapy was investigated using for the first time MRI at 21T. Tumor responses were detected by high resolution sodium and proton diffusion MRI in non-treated and BCNU treated 9L tumors. Steady increase of tumor sodium content in non-treated tumor was detected with a rate of ~ 5%/day. Both sodium and diffusion MRI can identify therapeutic response in a few days but can predict outcome only in ~ two weeks after initiation of therapy. The study supports the unique role of sodium homeostasis in tumors and the importance of sodium and diffusion MRI in evaluating and predicting efficacy of therapy.
11:18 613. Noninvasive Monitoring of CCl4 Induced Acute and Chronic Liver Damage in Rat by SQ and TQF 23Na MRI
    Yong Gao1, Judy James1, Navin Bansal1
Radiology, Indiana University School of Medicine, Indianapolis, IN, USA
    Single-quantum (SQ) and triple-quantum-filtered (TQF) 23Na MRI and shift-reagent- (SR-) aided 23Na and 31P MRS were employed to monitor the progression of liver injury by CCl4 intoxication of rats. Acute high-dose CCl4 (2.5 ml/kg) caused increase in SQ and TQF 23Na MRI signal intensity (SI) due to an increase in intracellular [Na+]. Chronic low-dose CCl4 (0.5 ml/kg twice weekly for 8 weeks) caused an increase in SQ SI due to increased extracellular space, and an increase in TQF SI due to extracellular fibroses. 23Na MRI may prove useful in diagnosis of liver diseases because of its sensitivity to liver injury.
11:30 614. Sodium MR Imaging at 3T Using an 8-Channel 23Na and 2-Channel 1H Rx/Tx Coil: Optimization and RF Inhomogeneity Corrections
    Judy Rose James1,2, Chen Lin1, Ulrike Dydak1,2, Andriy M. Babsky1, Helmut Stark3, Brian M. Dale4, Navin Bansal1,2
Radiology, Indiana University School of Medicine, Indianapolis, IN, USA; 2School of Health Sciences, Purdue University, West Lafayette, IN, USA; 3MRI Coils Research, Stark Contrast, Erlangen, Germany; 4Siemens Medical Solutions, Cary, NC, USA
    Initial 23Na MR images of the human torso acquired at 3-Tesla using an 8-channel dual tuned 23Na/1H transmit/receive coil after RF inhomogeneity corrections are presented. 23Na images were obtained with 0.3 cm spatial resolution and ~20 SNR in ~15 min with clear delineation between different abdominal organs and their sub-regions. These images were acquired with imaging parameters optimized under SAR limits for human scans. The ability to perform 23Na MRI in clinical settings is useful to non-invasively detect and diagnose diseases in various body organs due to the physiological significance of trans-membrane sodium gradient that is critical for cell survival.
11:42 615. Dynamic MRSI for Hyperpolarized [1-13C]-Pyruvate with Multiband Pulses Applied in the TRAMP Prostate Cancer Mouse Model
    Peder E. Z. Larson1, Robert Bok1, Adam B. Kerr2, Albert P. Chen3, Simon Hu1, Matthew L. Zierhut1, Michael Lustig2, John M. Pauly2, Sarah J. Nelson1, John Kurhanewicz1, Daniel B. Vigneron1
Radiology and Biomedical Imaging, University of California - San Francisco, San Francisco, CA, USA; 2Electrical Engineering, Stanford University, Stanford, CA, USA; 3Global Applied Science Lab, GE Healthcare, Toronto, Ontario, Canada
    We have applied a new serial, time-resolved 13C MRSI acquisition method for metabolic imaging in the TRansgenic Adenocarcinoma of Mouse Prostate (TRAMP) mouse model in order to investigate the uptake and metabolic dynamics within tumors and in normal tissues following injection of hyperpolarized pyruvate. This new method is based on tailored multiband excitation pulses that preserve the magnetization over time. The prostate tumors have characteristically high lactate conversion and, as this study showed, a characteristic dynamic curve. The results demonstrated significant tumor heterogeneity, with variations in pyruvate perfusion/uptake and lactate conversion.
11:54 616. In-Vivo Ultra-Fast Spectroscopic Imaging of 19F Containing Contrast Agents
    Rolf Lamerichs1, Caren van Kammen2, Muhammed Yildirim1, Klaas Nicolay3
Philips Research, Eindhoven, Netherlands; 2Maastricht University, Maastricht, Netherlands; 3Eindhoven University of Technology, Eindhoven, Netherlands
    Imaging of fluorine based contrast agents can play a major role in the context of Molecular Imaging. Here we show the in-vivo feasiblity of fast spectroscopic imaging of such agents.
12:06 617. Spin-Lock Sodium MRI of the Human Brain: A Preliminary Study
    David Thomas Pilkinton1, Mark A. Elliott1, Jeremy F. Magland2, Ravinder Reddy1
Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
    In this preliminary study, spin-lock sodium MRI was used to image agarose and human brain. Although measurements of T2 or T2* are sensitive to slow motion through the spectral density at zero frequency, slow dynamics are probed more efficiently through the application of a strong RF field near the kilohertz range. We demonstrate in sodium images of brain tissue and agarose that spin-locking provides significant contrast for macromolecular content due to its sensitivity to spins in slow molecular motion regimes.
12:18 618. Faster Sodium MRI Through TPI-SENSE: Results at 7T
    Yongxian Qian1, Graham Wiggins2, Lawrence L. Wald2, Fernando E. Boada1
Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA; 2Department of Radiology, Massachusetts General Hospital, Massachusetts, MA, USA
    This study presents parallel sodium (23Na) images of human brain on a whole-body 7T scanner using a 15-channel array coil and demonstrates the potential benefits of the TPI-SENSE technique in accelerating data acquisition. Our initial results shows that an acceleration of 2x3 (ring x rotation) is achievable using TPI-SENSE sodium parallel imaging with a 15-channel array coil without significant degradation in image quality