| Abbreviation | Definition |
|---|---|
| MRI | Magnetic Resonance Imaging |
| MRL | Maximum Residue Limit |
| MRRA | Microbial Research and Risk Assessment Staff |
| MRRA(CFSAN) | Microbial Research and Risk Assessment Staff (CFSAN) |
| MRS | Magnetic Resonance Spectroscopy |
| MRTP | Modified Risk Tobacco Products |
| MS | Mass Spectroscopy |
| MS | MediastinoScopy |
| MSAB | Manufacturing and Storage Adulteration Branch |
| MSAB(CFSAN) | Manufacturing and Storage Adulteration Branch (CFSAN) |
| MSB(NCTR) | Mass Spectrometry Branch (National Center for Toxicological Research) |
| MSDS | Material Safety Data Sheet(s) |
| MSDS | Material Safety Data Sheets |
| MSI | Magnetic Source Imaging |
| MSQA | Mammography Quality Standards Act of 1992 |
| MSS(CDRH) | Management Support Staff (Center for Devices and Radiological Health) |
| MSS(CVM) | Management Support Staff (CDRH) |
| MSSO | Maintenance And Support Services Organization |
| MSTD | Materials Science and Technology Department |
| MSU | Medical Statistics Unit |