Initial measurements of ifosfamide and cyclophosphamide in patients using (31)P MRS: pulse-and-acquire, decoupling,...

Ifosfamide and cyclophosphamide are (31)P-containing alkylating agents used widely in the treatment of cancer. In this communication it is demonstrated that signals from these agents may be detected in the livers of patients undergoing treatment using (31)P MRS at 1.5 T. In vitro, signals are enhanced 4-fold by use of (1)H-decoupling, with a B(1) field of 100 Hz at -150 Hz relative to water. Polarization transfer (BINEPT) enhances signals in vitro by a further factor of 5.5. Preliminary results using the double-resonance methods in vivo show that the technique is practicable although enhancements may be less than observed in vitro. Factors affecting signal enhancement in vivo are evaluated. Magn Reson Med 44:180-184, 2000.