Registered Diagnostic Cardiac Sonographer (RDCS) are credentials from the The American Registry for Diagnostic Medical Sonography (ARDMS).  The ARDMS is the largest worldwide sonography credentialing organization. Through its mission, ARDMS empowers sonographers to provide exceptional patient care through rigorous assessments and continuous learning.  To obtain certification, medical professionals must pass a rigorous examination that tests their knowledge and practical, real-world skills, all of which take years of training and experience to acquire.  When a sonography professional holds certification from ARDMS, you know that she is dedicated to providing high-quality care and meeting the highest standards. No one has to be certified; instead, they choose to be certified to show how seriously they take their work.