Diagnostic Medical Sonography News April 2020 | Page 3

large ultrasound machine that a sonographer has to wheel from one room to the
next? These are used for patients with and without COVID-19. The Butterfly is one
option that could help. This small device would provide mobility and is easier to
sanitize than the larger, bulkier machinery. The entire system is contained inside
a protective sheath, making it possible to disinfect just the device rather than the
entire imaging room. Point-of-care ultrasound systems also allow for the triage of
patients in tents or other areas outside of hospitals in which imaging modalities
are otherwise not available – they can be easily hooked up to an iPhone, allowing
for a quick diagnosis.
Ultrasounds are being used to get a peek at the walls of the lungs before the
decision is made to use a ventilator, which are more in demand than ever.
Sonographers never really scanned lungs much in the past (CT scans are the
preferred modality), so how can we help now? How do clinicians evaluate
patients for plural wall thickening and areas of congestion that are typical of
pneumonia – both of which are now being seen in patients with COVID-19?
Early literature suggests that patients with COVID-19 pneumonia show typical
lung imaging features, with pulmonary ground-glass, ground-glass or ground-
glass/consolidation lesions that are peripherally-located, bilateral and favor
the lower lungs. Sonographic features include focal and fused B-lines and a
discontinuous/rough appearance of the plural line with subpleural consolidation.
The foci of the disease are located predominantly in the posterior lung fields,
particularly in the lower lung fields. Knowing this, what is the best way to access
these images?
First, sonographers need to use a linear, sector or small curvilinear transducer.
The chest needs to be divided into parasternal, anterior and posterior axillary
lines. Next, the basilar, mid and apical (upper portion) of the chest should be
scanned. Then, the posterior portion of the chest (base, mid and superior
portions) should be scanned. For some patients, the supine position might be
the only way to access images. A normal lung ultrasound will show a clean linear
pleural line with A-lines and lung sliding with respiration. A-lines are multiple
horizontal reverb artifacts. A thick pleural line may suggest pneumonia, acute
respiratory distress syndrome or fibrosis. Irregular lines are also indicative of
COVID-19-related pneumonia.
Knowing how to differentiate between normal and abnormal images is the key
to helping to diagnose patients. As the number of COVID-19 cases increases,
protocol for scanning the lungs and chest could soon become an everyday
practice for sonographers. It is, therefore, important to have the right tools and
scanning techniques to navigate the pandemic safely, accurately and efficiently.
Nadja Alfonso Jean-Denis
References:
itnonline.com/videos/video-imaging-COVID-19-point-care-ultrasound-pocus
butterflynetwork.com/COVID-19#lungfindings
theatlantic.com/science/archive/2020/03/biography-new-coronavirus/608338/
sonographictendencies.com/2020/03/18/chest-and-lung-ultrasound/
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