COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

COVID-19 Evidence Alerts needs your support. If our service is of value to you, please consider donating to keep it going. Learn more Donate now

Diagnosis Shao JM, Ayuso SA, Deerenberg EB, et al. A systematic review of CT chest in COVID-19 diagnosis and its potential application in a surgical setting. Colorectal Dis. 2020 Sep;22(9):993-1001. doi: 10.1111/codi.15252. Epub 2020 Aug 5.

AIM: The aim of this work was to investigate the sensitivity and utility of CT of the chest in diagnosing active SARS-Cov-2 (COVID-19) infection, and its potential application to the surgical setting.

METHOD: A literature review was conducted using Google Scholar® and MEDLINE®/PubMed® to identify current available evidence regarding the sensitivity of CT chest compared with RT-PCR for the diagnosis of COVID-19-positive patients. GRADE criteria and the QUADAS 2 tool were used to assess the level of evidence.

RESULTS: A total of 20 articles were identified that addressed the question of sensitivity of CT for diagnosis of symptomatic and asymptomatic COVID-19-positive patients. Overall sensitivity of CT scan ranged from 57%-100% for symptomatic and 46%-100% for asymptomatic COVID-19 patients, while that of RT-PCR ranged from 39%-89%. CT chest was a better diagnostic modality and capable of detecting active infection earlier in the time course of infection than RT-PCR in symptomatic patients. In asymptomatic patients, disease prevalence seems to play a role in the positive predictive value. Minimal evidence exists regarding the sensitivity of CT in patients who are asymptomatic.

CONCLUSIONS: In surgical patients, CT chest should be considered as an important adjunct for detection of COVID-19 infection in patients who are symptomatic with negative RT-PCR prior to any operation. For surgical patients who are asymptomatic, there is insufficient evidence to recommend routine preoperative CT chest for COVID-19 screening.

Discipline / Specialty Area Score
Hospital Doctor/Hospitalists
Internal Medicine
Intensivist/Critical Care
Infectious Disease
Emergency Medicine
Comments from MORE raters

Infectious Disease rater

Just sensitivity and specificity are not enough for clinical use. We need likelihood ratios or predictive values at least.

Respirology/Pulmonology rater

Analysis of a number of retrospective studies suggests potential role of chest CT as a pre-op tool to rule out Covid-19. This does not address the significant number of patients with isolated interstitial abnormalities that confound the picture. The use of pre-op CT scanning will need prospective evaluation due to cost and radiation exposure to asymptomatic patients.