Patrick Rapley1, Katy Lynn Rich2, Mary Lynn Tassotto1
1Medical Physics, Thunder Bay Regional Health Science Centre, Thunder Bay, Ontario, Canada; 2Physics, Lakehead University, Thunder Bay, Ontario, Canada
This investigation demonstrates the feasibility of imaging the therapeutic response of HL-60 (human leukemia) cells by establishing a quantitative relationship between T2 enhancment and apoptotic extent. Heat shock induced apoptosis was probed by tagging with Annexin-V+SPIO in vitro and subsequent analysis of the transverse relaxation (T2) measured with a multi echo spin echo MRI acquisition. The results determined a linear relationship between spin-spin relaxivity (R2) and the percentage of apoptosis and also an increase in R2 as the concentration of cells increases. Targeting these nanoparticles to a specific biomarker enables the detection different levels of cell death using a clinical MRI.