Andrea Capozzi^1,2, Magnus Karlsson², Esben Søvsø Szocska Hansen³, Juan Diego Sanchez², Christoffer Laustsen³, Mathilde Hauge Lerche², Jacques Van Der Klink¹, and Jan Henrik Ardenkjær-Larsen^2
1Physics, EPFL, Lausanne, Switzerland, ²Technical University of Denmark, Kgs. Lyngby, Denmark, ³Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark

Dissolution DNP polarizers are expensive, technically demanding and require trained personnel. At the same time, hyperpolarized MR tracers have a half-life short enough to need the polarizer to be placed as close as possible to the MRI scanner. Similarly to PET tracers, being able to receive on demand hyperpolarized contrast agents from a centralized facility would solve this major shortcoming and boost the diffusion of hyperpolarized MR on a wider scale. In this work, using UV-induced non-persistent radicals and purpose build hardware, we demonstrate the first “across-cities-dDNP” experiment.

Adam W Autry¹, Sana Vaziri¹, Jeremy W Gordon¹, Marisa LaFontaine¹, Hsin-Yu Chen¹, Yaewon Kim¹, Javier Villanueva-Meyer¹, Susan M Chang², Jennifer Clarke^2,3, Nancy A Oberheim-Bush^2,3, Duan Xu¹, Janine M Lupo¹, Peder EZ Larson¹, Daniel B Vigneron^1,4, and Yan Li^1
1Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, ²Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States, ³Department of Neurology, University of California San Francisco, San Francisco, CA, United States, ⁴Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, United States

This study aimed to improve hyperpolarized carbon-13 (HP-¹³C) metabolic imaging methodologies for serial monitoring of patients with malignant brain tumors. Several analyses were pursued among 29 patients diagnosed with gliomas and 7 volunteers. Implementation of atlas-based prescription of echo-planar imaging (EPI) demonstrated consistent volumetric coverage (dice:0.967-0.978) and improved hemispheric symmetry in modeled kinetics(p=0.006), which helped highlight tumor. A 2s versus 5s acquisition delay post injection of tracer increased the capture of [1-¹³C]pyruvate inflow dynamics(p=0.04), while reducing simulated kinetic modeling error. Post-acquisition FID-CSI spectra demonstrated improved referencing of [1-¹³C]pyruvate f₀ using water versus a coil-embedded urea phantom(p=0.00003), thereby maximizing EPI excitation.

Nicole I.C. Cappelletto¹, Hany Soliman², Casey Y. Lee¹, Nadia D. Bragagnolo^1,3, Arjun Sahgal², Albert P. Chen⁴, Ruby Endre³, William J. Perks⁵, Nathan Ma⁵, Jay S. Detsky², Chris Heyn⁶, and Charles H. Cunningham^1,3
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, ²Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, ³Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, ⁴GE Healthcare, Toronto, ON, Canada, ⁵Pharmacy, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, ⁶Radiology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada

Brain metastases are increasingly being treated with stereotactic radiosurgery; however, 20-30% of treated tumors recur locally post-treatment. Hyperpolarized [1-¹³C]pyruvate magnetic resonance imaging (HP ¹³C MRI) is an emerging metabolic imaging modality that measures key metabolic phenotypes indicative of tumor biology. Here we investigate pre-treatment [1-¹³C]pyruvate uptake – a potential marker of monocarboxylate transporter 1 expression and tumor vascularity – via HP ¹³C MR images as a predictor of local recurrence. [1-¹³C]pyruvate uptake establishes a robust predictive model (AUC = 0.73) and, as a result, can inform treatment decisions should the model predict a non-response to SRS.

Kazutoshi Yamamoto¹, Yohei Kondo², Ana Opina³, Deepak Sail³, Natarajan Raju³, Burchelle Blackman³, Ronja M. Malinowski⁴, Tomohiro Seki¹, Shun Kishimoto¹, Nobu Oshima¹, Yasunori Otowa¹, Kota Yamashita¹, Daniel R. Crooks¹, Jeffrey R. Brender¹, Hiroshi Nonaka², Yutaro Saito², Peter L. Choyke¹, Jan H. Ardenkjær-Larsen ⁴, James B. Mitchell¹, W. Marston Linehan¹, Rolf Swenson³, Shinsuke Sando², and Murali C. Krishna^1
1National Cancer Institute, National Institutes of Health, Bethesda, MD, United States, ²Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Japan, ³National Heart, Lung, and Blood Institute, National Institutes of Health, Rockville, MD, United States, ⁴Department of Health Technology, Technical University of Denmark, Lyngby, Denmark

Molecular imaging can personalize cancer therapies by monitoring treatment responses, where hyperpolarized MRI is becoming an increasingly critical methodology.  However, the limited number of available probes, which can interrogate key physiology/biochemistry related to targeted diseases, remains one of the major challenges in this growing field.  In this presentation, we successfully demonstrate, for the first time, the advantages of newly synthesized ¹³C-Glutathione and ¹³C-N-acetyl cysteine probe in vivo redox status in a complementary manner.  This approach serves as powerful non-invasive biomarkers to assess oxidative stress, which plays a vital role in various diseases and can be translatable to the clinical diagnosis.

Pascal Wodtke¹, Martin Grashei¹, Frits H. A. van Heijster¹, Sandra Sühnel¹, Nadine Setzer¹, and Franz Schilling^1
1Department of Nuclear Medicine, Technical University of Munich, Munich, Germany

We introduce hyperpolarized [1,5-¹³C₂]Z-OMPD as a novel in vivo pH sensor. Upon synthesis from ethyl pyruvate, the molecule appears to be non-toxic and shows good hyperpolarization properties, as indicated by high polarization levels and long T₁ relaxation times for both ¹³C-labels. ¹³C-chemical shifts show good pH sensitivity in the physiological range, which enables pH imaging in vitro of human blood phantoms of different pH. In vivo pH imaging upon injection in rats reveals previously reported pH compartments in kidneys. It is further demonstrated, that the OMPD₁ peak can be used as internal reference, further facilitating the process.

Neil James Stewart^1,2, Qiwei Xiao^2,3, Matthew Willmering^2,3, Keith McConnell³, Hui Wang⁴, Robert Fleck⁵, Jason Woods^2,3, Raouf Amin³, and Alister Bates^2,3,5,6
1POLARIS, Imaging Sciences, Department of Infection, Immunity & Cardiovascular Disease, The University of Sheffield, Sheffield, United Kingdom, ²Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States, ³Division of Pulmonary Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States, ⁴MR Clinical Science, Philips, Cincinnati, OH, United States, ⁵Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States, ⁶Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, United States

Ummul AFIA Shammi¹, Lucia Flors Blasco², Talissa Altes³, John P. Mugler⁴, Craig Meyer⁴, Jaime Mata⁵, Kun Qing⁵, Wilson Miller⁵, and Robert Thomen^1
1Biomedical, Biological & Chemical Engineering, University of Missouri, Columbia, Columbia, MO, United States, ²Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, ³Department of Radiology, University of Missouri, Columbia, Columbia, MO, United States, ⁴Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ⁵Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States

Quantification of reginal pulmonary ventilation changes in a longitudinal study with hyperpolarized gas MRI would be beneficial for clinicians evaluating treatment responses. While VDP is a sensitive measure of global lung ventilation, regional ventilation information inherent in imaging is lost. In this work, we present a method of performing voxel-wise comparisons in ³He MRI and producing regional ventilation change maps in asthma patients following bronchodilation with either short-acting or long-acting beta agonists at three timepoints. Regional change maps were congruous with visual assessment of regional ventilation changes and showed the temporal effects of bronchodilator action in patients with severe asthma.