title: Development of high resolution 3D hyperpolarized carbon-13 MR molecular imaging techniques.
abstract: The goal of this project was to develop and apply techniques for T2mapping and 3D high resolution (1.5mm isotropic; 0.003cm3)13C imaging of hyperpolarized (HP) probes [1-13C]lactate, [1-13C]pyruvate, [2-13C]pyruvate, and [13C,15N2]urea in vivo. A specialized 2D bSSFP sequence was implemented on a clinical 3T scanner and used to obtain the first high resolution T2maps of these different hyperpolarized compounds in both rats and tumor-bearing mice. These maps were first used to optimize timings for highest SNR for single time-point 3D bSSFP acquisitions with a 1.5mm isotropic spatial resolution of normal rats. This 3D acquisition approach was extended to serial dynamic imaging with 2-fold compressed sensing acceleration without changing spatial resolution. The T2mapping experiments yielded measurements of T2values of >1s for all compounds within rat kidneys/vasculature and TRAMP tumors, except for [2-13C]pyruvate which was ~730ms and ~320ms, respectively. The high resolution 3D imaging enabled visualization the biodistribution of [1-13C]lactate, [1-13C]pyruvate, and [2-13C]pyruvate within different kidney compartments as well as in the vasculature. While the mouse anatomy is smaller, the resolution was also sufficient to image the distribution of all compounds within kidney, vasculature, and tumor. The development of the specialized 3D sequence with compressed sensing provided improved structural and functional assessments at a high (0.003cm3) spatial and 2s temporal resolution in vivo utilizing HP13C substrates by exploiting their long T2values. This 1.5mm isotropic resolution is comparable to1H imaging and application of this approach could be extended to future studies of uptake, metabolism, and perfusion in cancer and other disease models and may ultimately be of value for clinical imaging.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Milshteyn
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Cornelius
authors.initials: C
authors.lastname: von Morze
authors.affiliation: HeartVista Inc., Los Altos, CA, USA.
authors.forename: Galen D
authors.initials: GD
authors.lastname: Reed
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Shang
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Shin
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Zihan
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Hsin-Yu
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Bok
authors.affiliation: Department of Cell and Tissue Biology, University of California, San Francisco, CA, USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Goga
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: John
authors.initials: J
authors.lastname: Kurhanewicz
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Peder E Z
authors.initials: PE
authors.lastname: Larson
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA. Electronic address: dan.vigneron@ucsf.edu.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Vigneron
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000737:chemistry*; D005260:Female; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007668:Kidney / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D057054:Molecular Imaging; D009010:Monte Carlo Method; D009368:Neoplasm Transplantation; D019289:Pyruvic Acid / Q000378:metabolism; D051381:Rats; D014018:Tissue Distribution; D014508:Urea / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D019289:Pyruvic Acid; D014508:Urea
keywords: (13)C; DNP; Hyperpolarized; Pyruvate; SSFP; Urea