CEUS of the Lung Reveals Multiple Areas of Microthrombi in a COVID-19 Patient

A case of a 61-year-old woman (see Fig.  1) with severe COVID-19 and a negative CTPA study. We were able show that these areas of irregularity, labelled as subpleural consolidation by Peng et  al. were avascular and therefore most likely to represent 3–5 mm microinfarcts. Conversely, non-thrombotic consolidation would be seen to have some enhancement; a process not appreciated using other imaging modalities due to the superior spatial resolution of ultrasound. Anecdotally, we have also seen these areas resolve with clinical improvement. It is becoming apparent that severe cases of COVID-19 are characterised by hyperinfammation and a thrombotic phenomenon.

The theory of an underlying thrombotic process also corresponds with studies identifying admission D-dimer, prothrombin time and thrombocytopenia as prognostic markers [3]. Immuno-thrombosis is used to describe the interaction between platelets, coagulation factors and innate immune effector systems that, during an infection, results in secondary thrombus formation. This is not the first time CEUS has been used to evaluate the presence of emboli. Trenker et  al. found that, despite the lack of definite confirmation of PE on CT, peripheral subpleural consolidations with no or inhomogenous enhancement on CEUS to be highly suggestive of embolic consolidations [4].

A follow-up study by the same team used histological examination of six cases, and pulmonary infarction was found in all of them [5].

Lung abnormalties persist in 91% of COVID-19 patients

By Kate Madden Yee, AuntMinnie.com staff writer

September 10, 2021 -- More than 90% of patients who developed COVID-19 showed lung parenchymal abnormalities on chest CT and x-ray three months after recovery in a study published in the September issue of Clinical Infectious Diseases.

The findings highlight the need for further investigation into COVID-19's long-term effects, wrote a team led by Dr. Bram van den Borst of Radboud University Medical Center in Nijmegen, the Netherlands.

"Long-term health consequences of this coronavirus disease ... are yet largely unknown, but many patients are likely to experience long-lasting morbidity," the authors wrote. "Indeed, based on observations from diseases that share COVID-19 characteristics ... it is hypothesized that, in the long-term, a significant number of patients with COVID-19 will suffer from lung function impairment, residual pulmonary parenchymal abnormalities, decreased physical capacity, loss of muscle mass, anxiety, depression, cognitive deficits, post-traumatic stress disorder, fatigue, and poor health status" (Clin Infect Dis, September 2021, Vol. 73:5, pp. e1089-e1098).

The study included 124 patients who had been treated for COVID-19 at Radboud in 2020. Of the 124 patients, 27 had mild, 51 had moderate, 26 had severe, and 20 had critical disease. Each participated in a follow-up examination three months after recovery that consisted of lung function measurement tests, chest CT and x-ray, a six-minute walking test, and a body composition evaluation; each participant also responded to a questionnaire about their mental, cognitive, and health status, as well as their quality of life.

Although the majority of patients showed reduced ground-glass opacities on CT and normal chest x-rays at the three-month follow-up, the researchers also found that 91% had persistent parenchymal lung abnormalities, including ground-glass opacities, pleural lines and parenchymal bands, bronchiolectasis, and fibrosis. Nearly a third of patients had three lung abnormalities on CT at follow-up, and nearly a quarter had four.

CT imaging results in COVID-19 patients 3 months after recovery
Type of abnormality
Ground-glass opacity	86%
Lines and bands	64%
Bronchiolectasis	60%
Fibrosis	26%
No. of abnormalities
0	9%
1	20%
2	20%
3	27%
4	24%

The team also found the following:

• 72% of patients reported lower quality of life.
• 69% showed fatigue.
• 64% demonstrated functional impairment.
• 36% showed mental and/or cognitive function difficulties.

"Our results indicate that a substantial proportion of patients still experience severe problems in various health domains three months after COVID-19," the group wrote.

The study suggests that more research on the long-term effects of COVID-19 is needed, according to the authors.

"Longer follow-up studies are warranted to elucidate natural trajectories of COVID-19 recovery, to find predictors of complicated long-term trajectories, and to develop strategies to decrease long-term COVID-19 morbidity," they concluded.