COVID-19 CT severity index calculator

Note: this simple calculator provides a CTSI score of COVID-19 lung involvement, which has been correlated with clinical outcomes by several studies. Please bear in mind that the pandemic is an ongoing event, and therefore our understanding of the disease, and its imaging is evolving rapidly. First time users should read the detailed notes below the calculator too.

Notes

• The range of this semiquantitative score is between 0-25
• A CT score ≥ 18 was found to be associated with increased early mortality by one study done during the initial outbreak (early 2020)
  • ^{Francone M, Iafrate F, Masci GM, Coco S, Cilia F, Manganaro L, Panebianco V, Andreoli C, Colaiacomo MC, Zingaropoli MA, Ciardi MR, Mastroianni CM, Pugliese F, Alessandri F, Turriziani O, Ricci P, Catalano C. Chest CT score in COVID-19 patients: correlation with disease severity and short-term prognosis. Eur Radiol. 2020 Dec;30(12):6808-6817. doi: 10.1007/s00330-020-07033-y. Epub 2020 Jul 4. PMID: 32623505; PMCID: PMC7334627.}

• For more information about COVID-19 and its radiological manifestations please visit the regularly updated Radiopaedia.org article.
• Note that the COVID-19 CTSI only defines extent, but not the level of suspicion. The latter can be expressed by e.g. the CO-RADS categories. An excellent summary on the topic has been provided by the Radiology Assistant team.

Last updated: 2021-09-12