| RFT | respiratory function test; rod-and-frame test; right frontotransverse [fetal position] |
|---|---|
| RST | radiosensitivity test; reagin screen test; right sacrotransverse [fetal position]; rubrospinal tract... |
| SAST | Self-administered Alcoholism Screening Test; selective arterial secretin injection test; serum aspar... |
| STD | selective T-cell defect; sexually transmitted disease; skin-to-tumor distance; skin test dose; sodiu... |
| STS | sequence tagged site; serologic test for syphilis; sodium tetradecyl sulfate; sodium thiosulfate; st... |