title: T1 measurements in cell cultures: a new tool for characterizing contrast agents at 1.5T.
abstract: The objective of this work was to assess the feasibility and accuracy of T1 and relaxivity measurements in cell cultures using 1.5T magnetic resonance imaging (MRI) with the long-term goal to develop a tool for evaluation of novel paramagnetic agents in a realistic macromolecular environment. This initial study was carried out using MCF-7 cells treated with independently determined concentrations of Gd-DTPA. Two cell culture systems were evaluated: cell pellets and single layers of cells grown on microporous inserts. High-resolution T1 measurements of cell cultures were acquired with two dimensional Inversion Recovery Fast Spin Echo (2D-IR-FSE), three dimensional Inversion Recovery Fast Spin Echo (3D-IR-FSE), and 3D-SPGR sequences. The T1 and relaxivity accuracy of these sequences was confirmed with aqueous Gd-DTPA samples of known concentration. Relaxivities of 1.71 +/- 0.15 [mM(-1)second(-1)] and 1.55 +/- 0.50 [mM(-1)second(-1)] were measured in the cell pellets and cell monolayers, respectively, and were different from the value of 4.3 [mM(-1)second(-1)] for Gd-DTPA in water. Both cell pellets and monolayers are suitable for initial assessment of novel MR contrast agents.
authors.affiliation: Department of Radiology, Ohio State University, Columbus, Ohio 43210, USA. schmalbrock.l@osu.edu
authors.forename: P
authors.initials: P
authors.lastname: Schmalbrock
authors.forename: J V
authors.initials: JV
authors.lastname: Hines
authors.forename: S M
authors.initials: SM
authors.lastname: Lee
authors.forename: G M
authors.initials: GM
authors.lastname: Ammar
authors.forename: E W
authors.initials: EW
authors.lastname: Kwok
mesh_terms: D001943:Breast Neoplasms; D002478:Cells, Cultured; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA