| M1 | mitral first [sound]; myeloblast; slight dullness |
|---|---|
| M2 | dose per square meter of body surface; marked dullness; promyelocyte |
| M3 | absolute dullness; myelocyte at the 3rd stage of maturation |
| RBCD | right border cardiac dullness |
| RBD | recurrent brief depression; relative biological dose; right border of dullness |