Required Certifications: 1 of the following license or registry is required - -, RDMS, PS - American Registry of Diagnostic Medial Sonography (ARDMS) - Must obtain within 2 years of hire date. Recommended Certifications: ARRT - R.T.(S) or R.T.(VS) - American Registry of Radiology Technologist (ARRT), RDMS, AB, OB/GYN, PS - RDCS, AE, RVT, VT - American Registry of Diagnostic Medical Sonography (ARDMS).