Diagnostic Ultrasound Technicians operate diagnostic ultrasonic scanning equipment to produce cross sectional and two dimensional pictures of internal organs and body structures used to diagnose diseases and other medical conditions. Registration is offered by Cardiovascular Credentialing International (CCI) or by the American Registry of Diagnostic Medical Sonographers (ARDMS). BASIC REQUIREMENTS Citizenship. Citizenship of the United States. (Non-citizens may be appointed when it is not possible to recruit qualified citizens in accordance with chapter 3, section A, paragraph 3g, this part.) Education. There are no specific educational requirements for this occupation. Education may be substituted for experience only at the GS-4 and GS-5 levels. See the grade requirements part of this sta