title: In vivo dynamic MRI tracking of rat T-cells labeled with superparamagnetic iron-oxide particles.
abstract: Dynamic MRI tracking of rat T-cells in vivo is performed in rat testicles after labeling isolated rat T-cells in vitro with superparamagnetic dextran-coated iron-oxide particles, BMS180549. Tissue inflammation induced by the local injection of the calcium ionophore, A23187, is used to attract labeled T-cells. Gradient-echo MR images of rat testicles show a statistically significant decrease (4%) of the signal intensity in areas of injection of A23187 as early as 30 min after intravenous infusion of 2 x 10(8) labeled T-cells. The signal change reaches its maximum (6-7% decrease) at about 60-120 min after cell infusion. T2-mapping also shows a decrease of T2 in the areas with A23187. Image quantitation, which includes a chemical-shift effect, significantly enhances the sensitivity for detection of superparamagnetically labeled T-cells. Localization of labeled T-cells in rat testicles has been verified by fluorescence microscopy studies of T-cells co-labeled with a lipophilic fluorescent carbocyanine dye, 1,1-dioctadecyl-3,3,3',3'-tetramethyl-lindocarbocyanine perchlorate. These results represent the first successful demonstration of dynamic tracking of specific cells in vivo using MRI.
authors.affiliation: Pittsburgh NMR Center for Biomedical Research, Department of Biological Sciences, Carnegie Mellon University, PA 15213, USA.
authors.forename: T C
authors.initials: TC
authors.lastname: Yeh
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: S T
authors.initials: ST
authors.lastname: Ildstad
authors.forename: C
authors.initials: C
authors.lastname: Ho
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000009:adverse effects; D002232:Carbocyanines; D002465:Cell Movement; D002633:Chemotaxis; D003287:Contrast Media; D052203:Ferrosoferric Oxide; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D005583:Fourier Analysis; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008856:Microscopy, Fluorescence; D009920:Orchitis / Q000139:chemically induced / Q000473:pathology; D010087:Oxides; D051381:Rats; D011916:Rats, Inbred F344; D013382:Subtraction Technique; D013601:T-Lymphocytes / Q000473:pathology / Q000502:physiology*; D013737:Testis / Q000473:pathology*
chemical_list: D002232:Carbocyanines; D003287:Contrast Media; D005456:Fluorescent Dyes; D010087:Oxides; D000001:Calcimycin; C072024:carbocyanine dye DiIC12(3); D007501:Iron; D052203:Ferrosoferric Oxide