COVID-19 Chest CT

Summarized by: Lucy Samoilov, M.D.

Reviewed by: Prasaanthan Gopee-Ramanan, M.D.

Original publication details

Authors: Thomas C. Kwee, Robert M. Kwee

DOI: https://doi.org/10.1148/rg.2020200159

Reference: Kwee, T. C., & Kwee, R. M. (2020). Chest CT in covid-19: What the radiologist needs to know. RadioGraphics, 40(7), 1848–1865.

Chest CT protocol

COVID suspected/confirmed and referred for CT → non contrast-enhanced chest CT unless CT pulmonary angiography is required to detect pulmonary embolism (PE).

Low dose CT noninferior diagnostic quality ↓ radiation dose by 90% compared to standard CT.

Chest CT indications

Moderate to severe respiratory symptoms (i.e., presence of significant pulmonary dysfunction or damage) and any pretest probability of COVID-19 infection.

Chest CT findings

Most sensitive: ground-glass opacities, vascular enlargement, bilateral abnormalities, lower lobe involvement, and posterior predilection.

Complications

ARDS - older age confers increased risk

PE: 17-35% incidence - highest prevalence in those critically ill

Superimposed bacterial/fungal pneumonia: 10% of patients - look for lobar consolidation and/or cavitation

Cardiac injury: 12.5-19.7% of patients - look for nonspecific but important pericardial effusion [in 5.2% of patients]

Diagnostic accuracy*

94.6%

Chest CT sensitivity

46%

Chest CT specificity

*However, methodologic quality issues in the published diagnostic accuracy studies to date may have led to an overestimation of sensitivity, especially in asymptomatic patients

Reporting

Four categories for standardized COVID-19 reporting were proposed by the RSNA.

  1. Typical appearance

  2. Indeterminate appearance

  3. Atypical appearance

  4. Negative for pneumonia

Citation


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