@misc{oai:repo.qst.go.jp:00072718,
 author = {Matsumoto, Ken-ichiro and Subramanian, Sankaran and B., Mitchell James and C., Krishna Murali and 松本 謙一郎},
 month = {Jul},
 note = {In vivo decay rates of a nitroxyl contrast agent estimated by a MR redox imaging technique were compared with the decay rates obtained by the electron paramagnetic resonance spectroscopy (EPRS) and EPR imaging (EPRI). The MR redox imaging is a dynamic imaging employing T1-weighted pulse sequence, which can visualize a nitroxyl-induced enhancement of T1-weighted contrast. The EPR techniques can directly measure the paramagnetic nitroxyl radical. A female C3H mouse bearing SCC tumor on the right leg was anesthetized by isoflurane and fixed on the special mouse holder. The both tumor and normal legs were scanned by T1-weighted SPGR sequence at 4.7 T with a nitroxyl radical, carbamoyl-PROXYL, as the contrast agent. Similarly, time course of carbamoyl-PROXYL in normal muscle and tumor tissues was obtained using a surface coil resonator and a 700 MHz EPR spectrometer. The time course imaging of carbamoyl-PROXYL was also performed by 300 MHz continuous wave (CW) EPR imager. EPRS and EPRI gives slightly slow decay rates of carbamoyl-PROYXL compared to the MRI based signal decay rate. Relatively slow decay rate at peripheral region of the tumor tissues were found in the high-resolution image obtained by MRI. This slow decay in peripheral regions may contribute to the slower decay rates observed by EPRS and/or the EPRI measurements. ROI selection of estimate redox status in the tissue must consider heterogenic structure in the tumor tissue. Importance of appropriate choice of measuring volume and suitability of T1-weighted SPGR MRI based redox status estimation were confirmed., 1st QST International Symposium -Quantum Life Science-},
 title = {Importance of Suitable Volume Limitation for Estimating Tissue Redox Status Using a Nitroxyl Contrast Agent},
 year = {2017}
}