title: Effect of concentration of SH U 555A labeled human melanoma cells on MR spin echo and gradient echo signal decay at 0.2, 1.5, and 3T.
abstract: In the current study the effect of increasing concentrations of superparamagnetic iron oxide labeled cells on the MRI signal decay at magnetic field strengths of 0.2, 1.5, and 3 T was evaluated. The spin echo and gradient echo cellular transverse relaxivity was systematically studied for various concentrations (N = 1, 5, 10, 20, 40, and 80 cells/microl(gel)) of homogeneously suspended SH U 555A labeled SK-Mel28 human melanoma cells. For all field strengths investigated a linear relationship between cellular transverse relaxation enhancement and cell concentration was found. In the spin echo case, the cellular relaxivities [i.e., d(deltaR2)/dN] were determined to 0.12 s(-1) (cell/microl)(-1) at 0.2 T, 0.16 s(-1) (cell/microl)(-1) at 1.5 T, and 0.17 s(-1) (cell/microl) at 3 T. In the gradient echo case, the calculated cellular relaxivities (i.e., d(deltaR2*)/dN) were 0.51 s(-1) (cell/microl)(-1) at 0.2 T, 0.69 s(-1) (cell/microl)(-1) at 1.5 T, and 0.71 s(-1) (cell/microl)(-1) at 3 T. The proposed preparation technique has proven to be a simple and reliable approach to quantify effects of magnetically labeled cells in vitro. On the basis of this quantification well suited tissue specific models can be derived.
authors.affiliation: Department of Diagnostic Radiology, Section on Experimental Radiology, University Hospital Tübingen, Hoppe-Seyler-Str.3, Tubingen, 72076, Germany. Joerg.Pintaske@med.uni-tuebingen.de
authors.forename: J
authors.initials: J
authors.lastname: Pintaske
authors.forename: R
authors.initials: R
authors.lastname: Bantleon
authors.forename: R
authors.initials: R
authors.lastname: Kehlbach
authors.forename: C D
authors.initials: CD
authors.lastname: Claussen
authors.forename: J
authors.initials: J
authors.lastname: Wiskirchen
authors.forename: F
authors.initials: F
authors.lastname: Schick
mesh_terms: D016477:Artifacts; D002138:Calibration; D002478:Cells, Cultured; D003287:Contrast Media; D003911:Dextrans; D017352:Echo-Planar Imaging; D005290:Ferric Compounds / Q000737:chemistry; D052203:Ferrosoferric Oxide; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007501:Iron; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles; D008545:Melanoma / Q000473:pathology; D010087:Oxides; D013194:Staining and Labeling
chemical_list: D003287:Contrast Media; D003911:Dextrans; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; D010087:Oxides; C000499:ferric oxide; D007501:Iron; C065507:ferumoxides; D052203:Ferrosoferric Oxide