| PDI | pain disability index; periodontal disease index; plan-do integration; psychomotor development index... |
|---|---|
| SI | International System of Units [Fr. le Systeme International d'Unites]; sacroiliac; saline infusion; ... |
| SSI | segmental sequential irradiation; shoulder subluxation inhibition; small-scale integration; Social S... |
| TDI | temperature difference integration; three-dimensional interlocking [hip]; toluene 2,4-diisocyanate; ... |
| TI | inversion time; temporal integration; terminal ileum; thalassemia intermedia; therapeutic index; tho... |