title: Contrast Agent Mass Spectrometry Imaging Reveals Tumor Heterogeneity.
abstract: Mapping intratumoral heterogeneity such as vasculature and margins is important during intraoperative applications. Desorption electrospray ionization mass spectrometry (DESI-MS) has demonstrated potential for intraoperative tumor imaging using validated MS profiles. The clinical translation of DESI-MS into a universal label-free imaging technique thus requires access to MS profiles characteristic to tumors and healthy tissues. Here, we developed contrast agent mass spectrometry imaging (CA-MSI) that utilizes a magnetic resonance imaging (MRI) contrast agent targeted to disease sites, as a label, to reveal tumor heterogeneity in the absence of known MS profiles. Human breast cancer tumors grown in mice were subjected to CA-MSI using Gadoteridol revealing tumor margins and vasculature from the localization of [Gadoteridol+K](+) and [Gadoteridol+Na](+) adducts, respectively. The localization of the [Gadoteridol+K](+) adduct as revealed through DESI-MS complements the in vivo MRI results. DESI-MS imaging is therefore possible for tumors for which no characteristic MS profiles are established. Further DESI-MS imaging of the flux of the contrast agent through mouse kidneys was performed indicating secretion of the intact label.
authors.affiliation: †Techna Institute for the Advancement of Technology for Health, University Health Network, Toronto, Ontario M5G-1P5, Canada.|‡Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J-1P3, Canada.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Tata
authors.affiliation: †Techna Institute for the Advancement of Technology for Health, University Health Network, Toronto, Ontario M5G-1P5, Canada.
authors.forename: Jinzi
authors.initials: J
authors.lastname: Zheng
authors.affiliation: §Department of Surgery, University of Toronto, 149 College Street, Toronto, Ontario M5T-1P5, Canada.|⊥Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 30 Bond Street, Toronto, Ontario M5B-1W8, Canada.
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Ginsberg
authors.affiliation: †Techna Institute for the Advancement of Technology for Health, University Health Network, Toronto, Ontario M5G-1P5, Canada.|∥Department of Medical Biophysics, University of Toronto, 101 College Street, Suite 15-701, Toronto, Ontario M5G 1L7, Canada.
authors.forename: David A
authors.initials: DA
authors.lastname: Jaffray
authors.affiliation: ‡Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J-1P3, Canada.
authors.forename: Demian R
authors.initials: DR
authors.lastname: Ifa
authors.affiliation: †Techna Institute for the Advancement of Technology for Health, University Health Network, Toronto, Ontario M5G-1P5, Canada.|§Department of Surgery, University of Toronto, 149 College Street, Toronto, Ontario M5T-1P5, Canada.|⊥Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 30 Bond Street, Toronto, Ontario M5B-1W8, Canada.|∥Department of Medical Biophysics, University of Toronto, 101 College Street, Suite 15-701, Toronto, Ontario M5G 1L7, Canada.
authors.forename: Arash
authors.initials: A
authors.lastname: Zarrine-Afsar
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D051379:Mice; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D003287:Contrast Media