Principal Component Analysis Enhanced Dynamic Electron Paramagnetic Resonance Imaging of Cycling Hypoxia in vivo

Gage Redler¹, Boris Epel¹, Howard J. Halpern¹

Hypoxia in tumors affects their malignant state and resistance to therapy. These effects may be more deleterious in regions undergoing cycling hypoxia. Electron paramagnetic resonance imaging (EPRI) has provided a non-invasive, quantitative imaging modality to investigate static pO2 in vivo. However, to image cycling hypoxia, better temporal resolution may be required. The tradeoff between temporal resolution and SNR results in lower SNR for EPRI images with higher temporal resolution. Principal component analysis is presented as a spatiotemporal filter via low-order approximation of EPRI projection data, allowing studies with SNR and temporal resolution necessary to study cycling hypoxia in vivo.