| RRT | random response technique; Registered Respiratory Therapist; relative retention time |
|---|---|
| RT | radiologic technologist; radiotelemetry; radiotherapy; radium therapy; rapid tranquilization; reacti... |
| RTR | Recreational Therapist, Registered; red blood cell turnover rate; retention time ratio |
| SCRAM | speech-controlled respirometer for ambulation measurement |
| SDL | serum digoxin level; speech discrimination level |