31P spectrum (left panel) was acquired from perfused PC3 cells in agarose beads before chemotherapy. No significant change in the spectrum was observed following 2.5 hours of drug exposure (100 nM of taxotere). The α-, β-, and γ-ATP peaks are well resolved and the Pi peak is due to 31P in the perfusate. Experimental conditions: pulse sequence = single Rf pulse followed by signal detection, Rf flip angle = 70°, repetition time = 1 sec, and total acquisition time = 1 hour. 23Na TQ spectra (right panel) acquired from perfused PC3 cells in agarose beads before (A), 1.5 hours (B), and 3.5 hours (C) after chemotherapy (100 nM of taxotere). Experimental conditions: pulse sequence = , with the Rf phases cycled for TQF, repetition time = 0.2 sec, creation time τP = 3.2 ms, evolution time τE = 0.1 ms, and total acquisition time = 20 min.