When working in all other states: Credentialed with the American Registry of Radiologic Technologist (ARRT), American Registry of Diagnostic Medical Sonographers (ARDMS), or Cardiovascular Credentialing International (CCI), or registry eligible is required within 18 months of hire. When working or hired in South Dakota: American Registry of Diagnostic Medical Sonographers (ARDMS) or Cardiovascular Credentialing International (CCI), or registry eligible is required within 12 months into the position.