| Abbreviation | Definition |
|---|---|
| RI | Resistive Index |
| RIA | Radio Immuno-Assay |
| RIA | RadioImmunoAssay |
| RIBA | Recombinant ImmunoBlot Assay |
| RibB | Riboflavin Biosyntheses |
| RICS | Research Informatics Consult Service |
| RIDT | rapid influenza diagnostic test |
| RIDT | Rapid influenza diagnostic testing |
| RIF | Rotation Invariant Function |
| RIL | Radar Innovations Laboratory |
| RIL | Radiological Instrumentation Laboratory |
| RIM | Reference Information Model |
| RIND | Reversible Ischemic Neurological Deficit |
| RITA | Registry of Industrial Toxicology Animal data |
| RITDS | Real-Time Interactive Telepathology Diagnosis System |
| RITQ | Revised Infant Temperament Questionnaire |
| RIU | Radioactive Iodine Uptake |
| RLB | Research Laboratory Building |
| RLB | Royal Laboratory Birtley |
| RLIS | Rockville Laboratory Imaging System |