Comparison of T2 and T2* for Quantification of Cellular Iron-Uptake at 3.0 T
Dahnke H, Matuszewski L, Kuhlpeter R, Heindel W, Schaeffter T, Bremer C
Philips Research Laboratories
MRI relaxometry imaging is used for the quantification of super paramagnetic iron oxide (SPIO) contrast agent concentrations. The R2 (=1/T2) and R2* relaxation rates are exploited to obtain information about the concentration. Moreover, the question, whether the contrast agent is incorporated into cells or dissolved in liquid is addressed by measuring the difference R2=R2*-R2. If the SPIOs are compartmentalized in cells, the R2* relaxation rate is higher than R2; in case the SPIOs are dissolved in liquid the relaxation rates R2 and R2* are similar. We show that SPIO-labeled Human-lung-carcinoma-cells can be distinguished form free SPIO in phantom and in-vivo studies via the different relaxation properties of R2 and R2*.