| OpScan | optical scanning |
|---|---|
| ORD | optical rotatory dispersion; oral radiation death |
| OSA | obstructive sleep apnea; Office of Services to the Aging; Optical Society of America; ovarian sectio... |
| CAT | 1) Computerized(= Computed) Axial Tomography = CAT scan &n... |
| CT | 1) Computed(Computer) Tomography(-gram); 컴퓨터 단층 촬영 = CAT &... |