The VOICE for the Vascular Ultrasound Profession since 1977 The Society of Diagnostic Medical Sonography (SDMS) is a non-profit association for ultrasound professionals. Make a statement about quality: Get your lab accredited. The American Registry of Diagnostic Medical Sonographers (ARDMS) is an independent, nonprofit organization that administers examinations and awards credentials in the areas of diagnostic medical sonography, diagnostic cardiac sonography, vascular technology, and ophthalmic biometry. CCI is an independent not-for-profit corporation established for the purpose of administering credentialing examinations as an independent credentialing agency. CCI began credentialing cardiovascular professionals in 1968.