title: Detection of single mammalian cells by high-resolution magnetic resonance imaging.
abstract: This study reports the detection of single mammalian cells, specifically T cells (T lymphocytes) labeled with dextran-coated superparamagnetic iron oxide particles, using magnetic resonance microscopy. Size amplification due to sequestration of the superparamagnetic particles in vacuoles enhances contrast in localized areas in high-resolution magnetic resonance imaging. Magnetic resonance images of samples containing differing concentrations of T cells embedded in 3% gelatin show a number of dark regions due to the superparamagnetic iron oxide particles, consistent with the number predicted by transmission electron microscopy. Colabeling of T cell samples with a fluorescent dye leads to strong correlations between magnetic resonance and fluorescence microscopic images, showing the presence of the superparamagnetic iron oxide particles at the cell site. This result lays the foundation for our approach to tracking the movement of a specific cell type in live animals and humans.
authors.affiliation: Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Dodd
authors.forename: M
authors.initials: M
authors.lastname: Williams
authors.forename: J P
authors.initials: JP
authors.lastname: Suhan
authors.forename: D S
authors.initials: DS
authors.lastname: Williams
authors.forename: A P
authors.initials: AP
authors.lastname: Koretsky
authors.forename: C
authors.initials: C
authors.lastname: Ho
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D002232:Carbocyanines; D002465:Cell Movement; D003911:Dextrans; D052203:Ferrosoferric Oxide; D005456:Fluorescent Dyes; D006801:Humans; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D058185:Magnetite Nanoparticles; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D010087:Oxides; D051381:Rats; D011916:Rats, Inbred F344; D013601:T-Lymphocytes / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure
chemical_list: D002232:Carbocyanines; D003911:Dextrans; D005456:Fluorescent Dyes; D058185:Magnetite Nanoparticles; D010087:Oxides; C024286:3,3'-dioctadecylindocarbocyanine; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide