FDA relaxes rules on ultrasound in COVID-19

The FDA carved out a special section of the guidance for ultrasound systems, which have become useful in diagnosing patients with COVID-19. The agency said that because ultrasound scanners do not emit ionizing radiation, the FDA believes users can have "additional flexibility," with modifications allowed under the following circumstances:

• Modifications that would allow an ultrasound scanner to be used outside of the environment for which it is cleared, such as a general practitioner's office or a field hospital
• Changes that would enable the acquisition of images by healthcare practitioners who are not trained in sonography, under appropriate supervision
• The addition of lung scanning clinical applications, as long as labeling is included that is based on established practice guidelines, such as from the American Institute of Ultrasound in Medicine (AIUM)
• The availability of probes and machine settings that are suitable for lung scanning, such as probes at a frequency of 3 MHz and higher, and with linear, curvilinear, and phased-array technologies
• The use of a mechanical index (MI) < 1.4 as an indicator for potential biological effects on tissues containing gas bodies

The agency would frown on ultrasound modifications as follows:

• Changes that would result in an increase of the derated maximum acoustic output parameters
• Modifications that would exceed known safety limits in humans, such as a MI ≥ 1.4 for lung images
• Modifications that would allow lay users to acquire images without guidance of healthcare practitioners.

Abdominal Pain: An Unusual -- But Not Rare -- COVID-19 Presentation

• Whitney J. Palmer

April 20, 2020

Fever. Cough. Shortness of breath. These are what have become known as the classic, tell-tale COVID-19 symptoms. But, there’s a different, less common, one that should alert you to possible infection– abdominal discomfort.

Recent literature has revealed that as many as 20 percent of patients present to the hospital with a digestive symptom, such as diarrhea, vomiting, pain, accompanying their respiratory symptoms. And, roughly 5 percent show up with an abdominal complaint alone.
This is where abdominal radiologists can play an integral role, said industry experts in a recent article published in the American Journal of Roentgenology. A team, led by Abraham Dachman, M.D., professor of radiology and abdominal imaging specialist with UChicago Medicine, shared three cases where patients were referred for abdominal imaging and providers distinguished findings indicative of COVID-19 infection in the lung base.

“It’s important not to be lulled into a false sense of security by a chief complaint of abdominal pain,” Dachman wrote. “The fact that we observed several patients presenting in this way in such a short time period suggests that although abdominal symptoms are an unusual presentation of the infection, they are not rare, and abdominal radiologists must be on the lookout to diagnose COVID-19, even when it is not suspected clinically.”

Because these findings first appeared on abdominal scans, Dachman wrote, it’s important for all radiological sub-specialties to be aware that COVID-19 can produce abdominal complaints.

“Careful evaluation of the lung bases for the typical nodular, peripherally distributed ground-glass opacities may lead to the correct diagnosis before progressive respiratory manifestations,” he wrote. “An early diagnosis is helpful not only in patient care, but also in allowing healthcare workers to be prepared with the appropriate personal protective equipment.”