ABOUT US The American Registry of Radiologic Technologists (ARRT) is the world’s largest organization offering credentials in medical imaging, interventional procedures, and radiation therapy. We certify and register technologists in a range of disciplines by overseeing and administering education, ethics, and examination requirements. We also advocate for safety and advancement in radiological sciences professions by supporting initiatives such as the Image Gently™ Alliance and by contributing to industry research studies.