| AADR | American Academy of Dental Radiology |
|---|---|
| ACR | abnormally contracting region; absolute catabolic rate; acriflavine; adenomatosis of colon and rectu... |
| AHRA | American Hospital Radiology Administration |
| AOCR | American Osteopathic College of Radiology; American Osteopathic College of Rheumatology |
| ASTRO | American Society for Therapeutic Radiology and Oncology |