Related Experiment Video
Updated: Jun 10, 2026
Tumor Hypoxia Assessment: In Vivo 3D Oxygen Imaging Through Electron Paramagnetic Resonance
Published on: February 14, 2025
Electron paramagnetic resonance oxygen imaging of a rabbit tumor using localized spin probe delivery
Boris Epel1, Chad R Haney, Danielle Hleihel
1Department of Radiation and Cellular Oncology, The University of Chicago, MC 1105, Chicago, Illinois 60637, USA.
Purpose:
Application of in vivo electron paramagnetic resonance (EPR) oxygen imaging (EPROI) to tumors larger than those of mice requires development of both instrumental and medical aspects of imaging.
Methods:
250 MHz EPR oxygen imaging was performed using a loop-gap resonator with a volume exceeding 100 cm3. The paramagnetic spin probe was injected directly into the femoral artery feeding the rabbit leg/tumor.
Results:
The authors present continuous wave and electron spin echo EPR oxygen images of a large size (4 cm) VX-2 tumor located on the leg of a New Zealand white rabbit.
Conclusions:
This study demonstrates the feasibility of continuous wave and electron spin echo oxygen imaging modalities for investigation of volumes of tumor and normal tissue relevant to large animals. The injection of the spin probe directly into the artery feeding a rabbit leg will allow one to reduce, by over one order of magnitude, the amount of spin probe used as compared to whole animal i.v. injection.
