TRIAGE OF COVID-19 BY LUNG ULTRASOUND

 by Robert  Bard MD, FASL  with contributors: Dr. K. Lessnau, New York with Dr. D. Buonsenso, Rome

The use of CT lung imaging for COVID-19 has been the diagnostic standard for the last few months of the current epidemic.  CT has the disadvantage of logistics (staff, patients, transport) and radiation exposure. Respiratory distress creates motion artifacts on images that may simulate pulmonary inflammation. Since the disease mutates often, frequent imaging may be required. Viral pneumonia is not diagnostically distinguishable from other viral inflammations in the lung so the argument for a screening modality is useful to separate the critically ill from those needing outpatient treatment.  Dr. Klaus Lessnau, author of CHEST ULTRASOUND (Springer 2003), employs both CT and ultrasound imaging in clinical practice.

Ultrasound probes have the ability to screen the lungs for respiratory
issues and is a useful TRIAGE tool- however no radiological device
has been able to identify pulmonary viruses directly

Front line physicians in Italy and Spain are triaging with portable bedside ultrasound units that reduce logistical problems of a chaotic environment and healthcare worker exposure. Since imaging with CT or ultrasound is not diagnostic, determining who needs hospitalization is essential in a pandemic that is overwhelming medical providers and hospital resources.  Dr. Buonsenso, on the front lines in Rome, uses sonograms to decide who gets a CT scan. This is key since deep cleaning a CT room after a suspected patient shuts the room down for up to 2 hours for decontamination.

Lung ultrasound has been used in emergency rooms since it was introduced to the Mt Sinai Med School (New York) Emergency Department in 2014 and is now used nationwide to diagnose pneumonia (viral or bacterial) in children which spares them unnecessary x-rays since it is so caccurate. It is like an electronic stethoscope since lung disease and heart failure producing pulmonary fluid buildup are diagnosed or confirmed with portable ultrasound units at the bedside. This is considered the best imaging tool to diagnose a collapsed lung in seconds which has proven lifesaving as a time saver for on the spot detection. While it was assumed that children are carriers and not clinically affected, Dr. Buonsenso is actively investigating this population and there are findings that are concerning with the expanded use of lung ultrasound in this understudied group.

Disease of the lung from fluid overload-infection, 

heart failure-produces vertical white lines (B-Lines)

Ultrasound probes study the lungs via the ribs showing the lung surface (where most Covid pathology is situated) and adjacent lung tissue. The abdominal scan with the curved transducer has a larger field of view and affords a rapid assessment of B lines (Fig 1), pleural effusion and frank pneumonia (Fig 2).  Portable units have the advantage of containment within a sterile sleeve preventing accidental viral spread to imaging equipment necessitating full decontamination procedures.  Some infected European physicians are monitoring their disease at home via the B line count-few B lines suggest low grade inflamed lung tissue-increasing B line count calls for more aggressive treatment. All clinical imaging was correlated with the patient’s oxygen saturation and clinical setting.  The virus has potential cardiac toxicity so the same sonogram unit may image the heart for fluid buildup and weakened contraction. This may differentiate heart failure from pulmonary infection in some cases which may have similar clinical presentations.

REFERENCE
Bard R: 3D Imaging of Pulmonary Edema in Proceedings of 2020 Annual  American Institute of Ultrasound in Medicine ;Supplement to Journal of Ultrasound in Medicine  July 2020 (in press)

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CONTRIBUTING WRITER

ROBERT L. BARD, MD, PC, DABR, FASLMS - Advanced Imaging & Diagnostic Specialist
Having paved the way for the study of various cancers both clinically and academically, Dr. Robert Bard co-founded the 9/11 CancerScan program to bring additional diagnostic support to all first responders from Ground Zero. His main practice in midtown, NYC (Bard Diagnostic Imaging- www.CancerScan.com) uses the latest in digital Imaging technology has been also used to help guide biopsies and in many cases, even replicate much of the same reports of a clinical invasive biopsy. Imaging solutions such as high-powered Sonograms, Spectral Doppler, sonofluoroscopy, 3D/4D Image Reconstruction and the Spectral Doppler are safe, noninvasive, and does not use ionizing radiation. It is used as a complement to find anomalies and help diagnose the causes of pain, swelling and infection in the body’s internal organs while allowing the diagnostician the ability to zoom and ‘travel’ deep into the body for maximum exploration.