Virtual Radiologic (vRad), a technology-enabled national radiology practice and the largest telemedicine company in the world, and its subsidiary, NightHawk Radiology Services (NRS), have filed a lawsuit today in the United States District Court for the District of Arizona claiming patent and copyright infringement and misappropriation of trade secrets by Tandem Radiology and certain of its employees and founders, and claiming infringement of patent rights by Direct Radiology and Imaging Advantage through their use of Tandem's platform.