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Lung Damage May Persist Long After COVID-19 Pneumonia

The COVID-19 pandemic has considerably increased the demand for acute and postacute health care worldwide. COVID-19’s short-term effects on the lungs, such as pneumonia, are well documented, but much less is known about the illness’ long-term effects. According to a study published recently in Radiology, some people recovering from COVID-19 pneumonia have CT evidence of damage to their lungs that persists a full year after the onset of symptoms.

As part of an Austria-based observational study on the development of lung disease in patients with SARS-CoV-2 infection, researchers looked at patterns and rates of improvement of chest CT abnormalities in patients one year after COVID-19 pneumonia. CT has been an important imaging tool in the workup of patients suspected of having COVID-19.

The researchers assessed lung abnormalities on chest CT in 91 participants with a mean age of 59 years at several points over one year after the onset of COVID-19 symptoms. At one year, CT abnormalities were present in 49 (54%) of the 91 participants. Of these 49 participants, two (4%) had received outpatient treatment only, while 25 (51%) were treated on a general hospital ward and 22 (45%) had received ICU treatment.

“The observed chest CT abnormalities from our study are indicative of damaged lung tissue,” says study coauthor Anna Luger, MD, from the department of radiology at Innsbruck Medical University in Austria. “However, it is currently unclear if they represent persistent scarring and whether they regress over time or lead to pulmonary fibrosis.”

While CT abnormalities decreased in initial follow-ups, 63% of participants with abnormalities did not show any further improvement after six months. Age over 60 years, critical COVID-19 severity, and male gender were associated with persistent CT abnormalities at one year.

Evidence from the SARS-CoV-1 outbreak of 2002 to 2004 shows that lung abnormalities may remain detectable, but do not show any progression, even after decades, according to study coauthor Leonhard Gruber, MD, from the department of radiology at Innsbruck Medical University. Recent studies, though, have shown a risk of progression of lung abnormalities such as the ones depicted on CT.

“In a recently published clinical study of our CovILD interdisciplinary working group, we were able to show that the severity of acute COVID-19, protracted systemic inflammation, and the presence of residual chest CT abnormalities are strongly related to persistently impaired lung function and clinical symptoms,” says study coauthor Christoph Schwabl, MD, from Innsbruck Medical University.

The study underscores radiology’s role in helping identify patients at risk for post–COVID-19 consequences and assisting in COVID-19 follow-up management. The researchers intend to continue gathering data on patients with persistent CT abnormalities.

“In the end, long-term follow-up, both clinical and radiological, is necessary to gather more information about the course and clinical role of persisting SARS-CoV-2–related chest CT abnormalities,” says study senior author Gerlig Widmann, MD, chief thoracic radiologist at Innsbruck Medical University.

— Source: RSNA


Noncancerous Chest CT Features Help Predict Cancer Survival

Noncancerous imaging markers on chest CT performed before stereotactic body radiation therapy (SBRT) improve survival prediction, compared with clinical features alone, according to a recent study in the American Journal of Roentgenology.

“In patients undergoing SBRT for stage I lung cancer, higher coronary artery calcium (CAC) score, higher pulmonary artery (PA)-to-aorta ratio, and lower thoracic skeletal muscle index independently predicted worse overall survival,” says corresponding author and 2019 American Roentgen Ray Society Scholar Florian J. Fintelmann, MD.

Fintelmann and his team’s retrospective study included 282 patients (168 female, 114 male; median age 75 years) with stage I lung cancer who were treated with SBRT between January 2009 and June 2017. To quantify the CAC score and PA-to-aorta ratio, as well as emphysema and body composition, pretreatment chest CT was used. Associations of clinical and imaging features with overall survival were quantified using a multivariable Cox proportional hazards model.

For stage I lung cancer patients treated with SBRT, CAC score, PA-to-aorta ratio, and skeletal muscle index showed significant independent associations with overall survival (p<0.05). The model including clinical and imaging features demonstrated better discriminatory ability for five-year overall survival than the model including clinical features alone (AUC 0.75 vs 0.61, p<0.01).

“The PA-to-aorta ratio, which is readily quantifiable with electronic calipers during routine image review, was the most important predictor of overall survival,” the authors concluded.

— Source: American Roentgen Ray Society