National Cancer Center Hospital East 1 article published in JoVE Environment Visualization of Low-Level Gamma Radiation Sources Using a Low-Cost, High-Sensitivity, Omnidirectional Compton Camera Hiroshi Muraishi1, Ryoji Enomoto2, Hideaki Katagiri3, Mika Kagaya4, Takara Watanabe5, Naofumi Narita3, Daisuke Kano5 1School of Allied Health Sciences, Kitasato University, 2Institute for Cosmic Ray Research, University of Tokyo, 3College of Science, Ibaraki University, 4National Institute of Technology, Sendai College, 5National Cancer Center Hospital East We present experimental protocols for visualizing various low-level gamma radiation sources in the ambient environment using a low-cost, high-sensitivity, omnidirectional, gamma-ray imaging Compton camera.