Chest CT findings in patients with Omicron versus Delta variants in SARS-CoV-2 infection

The SARS-CoV-2 omicron variant shows fewer and less severe changes on chest CT than the delta variant, according to a paper published in Radiology.  However, it does have at least one distinct manifestation that of bronchial thickening.  More of the patients who contracted the omicron variant had normal results on computed tomography.  The SARS-CoV-2 omicron variant spreads rapidly but has lower rates of hospital admission and disease severity.

Long-term Sequelae in Covid-19 patients; CT Findings

A study of 118 patients with Covid-19 had both baseline and six months follow-up computed tomograms.  At follow-up chest CT 72% of the patients showed fibrotic-like changes while 42% showed ground glass opacifications.  The researchers concluded that blending clinical data with baseline chest CT findings can effectively anticipate which Covid-19 patients are a higher risk of long-term sequelae. 

Coronary Artery Calcium on Chest CTs and Mortality Risk.

A study by Hughes-Austin et al published in the Journalof the American College of Cardiology: Cardiovascular Imaging reported on the correlation between coronary artery calcium (CAC) scores on 3 mm electrocardiography (ECG)-gated computed tomography (CT) scans and standard 6 mm chest CT scans, and compared their associations of CAC on each scan type with mortality risk.

The investigators analyzed CT studies of 4,544 patients (mean age 68), who had standard 6mm CT that were followed with 3mm EKG gated CTs.  The Agatston method quantified CAC on both scans.  The median CAC scores were lower on 6 mm CTs compared to 3 mm CTs (22 vs.104 Agatston units, p < 0.001).

During the study period 157 deaths were recorded.  Adjusted for traditional CVD risk factors, when CAC scores were evaluated as a continuous variable each standard deviation higher CAC score on both 6 mm and 3 mm CTs was associated with 1.5-fold or 50% higher odds of mortality. 

The authors concluded that CAC scores on standard 6 mm chest CTs correlate well with 3 mm ECG-gated CTs and can predict mortality risk similarly in patients whose CTs were performed for other clinical indications without additional radiation exposure or expense.