I'm an emergency medicine resident with a special interest in ultrasonography: should I take a certification examination?

I am a second-year emergency medicine resident and I have been interested in ultrasonography since the beginning of my residency. During my internship, I realized that integrating this technology into my patient care helped my clinical practice. Because critical care emergency medicine is my primary interest, I wondered whether there was a way of distinguishing myself in terms of proficiency in performing and interpreting ultrasonographs that did not require me to complete a second fellowship. One day, at the bedside of an unstable patient who had fainted, my senior resident was performing a focused ultrasonograph of the abdominal aorta, and he casually mentioned how impressed he was by residents who obtained their Registered Diagnostic Medical Sonographer (RDMS) certification during their residency years. RDMS certification during residency? I hadn’t realized I could obtain this certification without completing an ultrasonographic fellowship. The terms competence, credential, accreditation, and certification are often used without a clear understanding of the differences between them. Competence is the recognition of ability or a skill. A resident can be deemed competent to perform a given emergency ultrasonographic examination, but competence does not grant that resident the credential to perform the skill in a clinical setting. An institution grants recognition of competence through a credentialing process. Because credentials are hospital specific, they are not necessarily transferable from one institution to another. An accreditation is conferred by a national body to a hospital or department when a certain standard has been met. For example, the American Council of Graduate Medical Education accredits emergency medicine residency programs. As such, accreditation does not apply directly to the individual. A certification is an official document attesting to a level of achievement of training. The American Registry for Diagnostic Medical Sonography (ARDMS) confers an RDMS certificate. Bedside sonography for diagnosis and procedural guidance is not exclusive to emergency medicine. Many professional medical societies have written specialty-specific guidelines for ultrasonographic use. However, a standard specialty-specific certification for emergency ultrasonography does not currently exist. An informal survey conducted by the American College of Emergency Physicians (ACEP) emergency ultrasonographic t