|Alliance Healthcare Services, Inc., is a national provider of advanced outpatient diagnostic imaging and radiation therapy services. The Company provides imaging and therapeutic services primarily to hospitals and other healthcare providers on a shared-service and full-time service basis. The Company also provides services through fixed-site imaging centers, primarily to hospitals or health systems. The Company's services normally include the use of its imaging systems, technologists to operate the systems, equipment maintenance and upgrades and management of day-to-day shared-service and fixed-site diagnostic imaging operations. The Company also provides non scan-based services, which include only the use of its imaging systems under a short-term contract. In April 2011, the Company acquired 24/7 Radiology, a professional radiology services Company. In April 2011, the Company purchased all of the outstanding membership interests of US Radiosurgery, LLC .