| IEI | isoelectric interval |
|---|---|
| IMI | immunologically measurable insulin; impending myocardial infarction; Imperial Mycological Institute ... |
| INT | intermediate; intermittent; intern, internship; internal; interval; intestinal; intima; p-iodonitrot... |
| IPI | interpulse interval |
| ISI | infarct size index; initial slope index; injury severity index; Institute for Scientific Information... |