Detection of Apoptotic Cell Death in Vitro Using Quantitative Magnetization Transfer

Colleen Bailey^1,2, Kimberly L. Desmond^1,2, Gregory J. Czarnota^1,2, Greg J. Stanisz^1,2

Acute myeloid leukemia cells were treated with cisplatin to induce apoptosis and spun into a cell sample for imaging. Magnetization transfer scans were performed at 427 and 243 Hz peak power, for sixteen offset frequencies logarithmically spaced from 0.12 to 200 kHz. The magnetization transfer ratio at 2320 Hz showed a statistically significant increase from 24.8% in control cells to 28.0% thirty-six hours after cisplatin treatment and 30.3% forty-eight hours after cisplatin treatment, preceding T1 changes. Quantitative fitting showed an increase macromolecular/free water proton exchange and a decrease in T_2B, which characterizes the width of the macromolecular lineshape.