NightHawk Radiology Holdings announced the acquisition of Teleradiology Diagnostic Service (TDS), a California-based provider of off-hours teleradiology services. TDS is a top provider of off-hours teleradiology services on the West Coast, providing services to hospitals throughout California, the largest market in the U.S., the companies said.

"We are pleased to significantly expand our presence in California. Together with TDS, we believe that we are now the largest provider of off- hours teleradiology services in that state," said Dr. Paul Berger, chairman and chief executive officer, NightHawk. "We are also excited to add TDS's outstanding radiologists to our team. TDS is renowned for its quality of service and customer retention, both of which are cornerstones of NightHawk's success."

Upon the close of the acquisition, TDS will operate as a subsidiary of NightHawk Radiology Holdings. Dr. Wilson Wong, chief executive officer and president of TDS, will continue to lead TDS's operations.