There are multiple definitions:

1. numerical rating scale(English)

   • NRS-BP, NRS-LP, PRO, IPCA, ASA, EMS, HEMS, VAS, PONV, SPI, ODI, ACDF, AE, CAC, CDA, DDD, FDA, FSU, HO, HPD, IDE, LP, MCS, NDI, PCS, SF-36
   • Scoring systems/scales, Pain, Monitoring, Spine (or spinal cord)
   • https://doi.org…man.2016.08.009
   • https://doi.org…17.5.FOCUS17188
   • https://doi.org…jnccn.2022.7034
   • https://doi.org…55/2022/3677688
   • https://doi.org…000605231198386
   • https://doi.org…6.10.SPINE16264

2. napkin ring sign(English)

   • cross-section of a coronary artery showing luminal narrowing by a low attenuating eccentric structure, surrounded by a thin ring-like hyperattenuating rim
   • CCTA, LAP
   • Cardiology, Medical imaging, Coronary circulation
   • https://radiopa…ring-sign-heart

3. normal rabbit serum(English)

   • ATTC, BMMC, MCP-1, MIP-1a, PCA, TGF-ß
   • Clinical chemistry
   • https://doi.org…mai.2000.107036

4. non-randomized study(English)

   • BCVA, DMEK, DSAEK, FED
   • Statistics, Ophthalmology
   • https://doi.org…8.CD012097.pub2

5. Nederlandse Respiratoire Vereniging(Dutch)

   • Respiratory system, Organizations (scientific)
   • https://www.nrs-science.nl/