| SI | System of International Units (Systeme International D'unites) |
|---|---|
| SI | International System of Units [Fr. le Systeme International d'Unites]; sacroiliac; saline infusion; ... |
| ICD | I-cell disease; immune complex disease; implantable cardioverter defibrillator; impulse-control diso... |
| IPA | immunoperoxidase assay; incontinentia pigmenti achromians; independent physician or practice associa... |
| BIPM | International Bureau of Weights and Measures [Fr. Bureau International des Poids et Mesures] |