| HFDA | high film density area |
|---|---|
| OFD | object-film distance; occipital frontal diameter; oro-facial-digital [syndrome] |
| ofd | object-film distance |
| RP | radial pulse; radiopharmaceutical; rapid processing [of film]; Raynaud phenomenon; reactive protein;... |
| SF | Sabin-Feldman [test]; safety factor; salt-free; scarlet fever; screen film; seminal fluid; serosal f... |