title: Rapid in vivo apparent diffusion coefficient mapping of hyperpolarized (13) C metabolites.
abstract: OBJECTIVE
  Hyperpolarized (13) C magnetic resonance allows for the study of real-time metabolism in vivo, including significant hyperpolarized (13) C lactate production in many tumors. Other studies have shown that aggressive and highly metastatic tumors rapidly transport lactate out of cells. Thus, the ability to not only measure the production of hyperpolarized (13) C lactate but also understand its compartmentalization using diffusion-weighted MR will provide unique information for improved tumor characterization.
  
  
  METHODS
  We used a bipolar, pulsed-gradient, double spin echo imaging sequence to rapidly generate diffusion-weighted images of hyperpolarized (13) C metabolites. Our methodology included a simultaneously acquired B1 map to improve apparent diffusion coefficient (ADC) accuracy and a diffusion-compensated variable flip angle scheme to improve ADC precision.
  
  
  RESULTS
  We validated this sequence and methodology in hyperpolarized (13) C phantoms. Next, we generated ADC maps of several hyperpolarized (13) C metabolites in a normal rat, rat brain tumor, and prostate cancer mouse model using both preclinical and clinical trial-ready hardware.
  
  
  CONCLUSIONS
  ADC maps of hyperpolarized (13) C metabolites provide information about the localization of these molecules in the tissue microenvironment. The methodology presented here allows for further studies to investigate ADC changes due to disease state that may provide unique information about cancer aggressiveness and metastatic potential.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.|UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley and University of California, San Francisco, California, USA.
authors.forename: Bertram L
authors.initials: BL
authors.lastname: Koelsch
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.|UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley and University of California, San Francisco, California, USA.
authors.forename: Galen D
authors.initials: GD
authors.lastname: Reed
authors.affiliation: Department of Radiology and Molecular Pharmacology and Chemistry Program, Memorial Sloan Kettering Cancer Center, New York, USA.
authors.forename: Kayvan R
authors.initials: KR
authors.lastname: Keshari
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.
authors.forename: Myriam M
authors.initials: MM
authors.lastname: Chaumeil
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Bok
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.|UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley and University of California, San Francisco, California, USA.
authors.forename: Sabrina M
authors.initials: SM
authors.lastname: Ronen
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.|UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley and University of California, San Francisco, California, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Vigneron
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.|UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley and University of California, San Francisco, California, USA.
authors.forename: John
authors.initials: J
authors.lastname: Kurhanewicz
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.|UC Berkeley - UCSF Graduate Program in Bioengineering, University of California, Berkeley and University of California, San Francisco, California, USA.
authors.forename: Peder E Z
authors.initials: PEZ
authors.lastname: Larson
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology; D002247:Carbon Isotopes / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D045744:Cell Line, Tumor; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D019047:Phantoms, Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D002247:Carbon Isotopes; D019344:Lactic Acid
keywords: ADC mapping; diffusion-weighted imaging; dissolution DNP; hyperpolarized 13C; metabolic imaging