| RAMP | radioactive antigen microprecipitin; right atrial mean pressure |
|---|---|
| RAU | radioactive uptake |
| RI | radiation intensity; radioactive isotope; radioimmunology; recession index; recombinant inbred [stra... |
| RIHSA | radioactive iodinated human serum albumin |
| RISA | radioactive iodinated serum albumin; radioimmunosorbent assay |