Continuous wave EPR oximetric imaging at 300 MHz using radiofrequency power saturation effects

Yukihiro Hama, Ken Ichiro Matsumoto, Ramachandran Murugesan, Sankaran Subramanian, Nallathamby Devasahayam, Janusz W. Koscielniak, Fuminori Hyodo, John A. Cook, James B. Mitchell, Murali C. Krishna

    Research output: Contribution to journalArticlepeer-review

    7 Citations (Scopus)


    A novel continuous wave (CW), radiofrequency (RF), electron paramagnetic resonance (EPR) oximetric imaging technique is proposed, based on the influence of oxygen concentration on the RF power saturation of the EPR resonance. A linear relationship is demonstrated between the partial oxygen pressure (pO 2) and the normalized signal intensity (IN), defined as, IN = (IHP - ILP)/ILP, where I LP and IHP refer to signal intensities at low (P L) and high (PH) RF power levels, respectively. A formula for the determination of pO2, derived on the basis of the experimental results, reliably estimated various oxygen concentrations in a five-tube phantom. This new technique was time-efficient and also avoided the missing angle problem associated with conventional spectral-spatial CW EPR oximetric imaging. In vivo power saturation oximetric imaging in a tumor bearing mouse clearly depicted the hypoxic foci within the tumor.

    Original languageEnglish
    Pages (from-to)1709-1716
    Number of pages8
    JournalAntioxidants and Redox Signaling
    Issue number10
    Publication statusPublished - Oct 1 2007

    All Science Journal Classification (ASJC) codes

    • Biochemistry
    • Physiology
    • Molecular Biology
    • Clinical Biochemistry
    • Cell Biology


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