| MCx | main circumflex [artery] |
|---|---|
| MD | Doctor of Medicine [Lat. Medicinae Doctor]; magnesium deficiency; main duct; maintenance dose; major... |
| MPD | main pancreatic duct; maximum permissible dose; mean population doubling; membrane potential differe... |
| MPV | main portal vein; mean platelet volume; mitral valve prolapse |
| MRA | magnetic resonance angiography; main renal artery; marrow repopulation activity; medical record anal... |