As COVID-19 tests remain scarce, some physicians turn to CT for diagnosis

April 13, 2020
by Thomas Dworetzky, Contributing Reporter
Faced with government snafus that have hampered the rollout of adequate numbers of diagnostic tests for COVID-19, some U.S. physicians are turning to expensive CT scans.

It “is really a failure of the system to have adequate tests,” Brigham and Women’s Hospital emergency medicine physician Dr. Jeremy Faust told Bloomberg.

He used CT during the initial phase of the outbreak when no tests were available.

“The problem is, in a lot of small community hospitals, we’re waiting up to 12 days” for results, Georgia radiologist Dr. Daniel Ortiz, told the news service, adding, “at that point, a test that’s essentially not available is worthless.”

At healthcare facilities from rural Georgia to major centers in New York, scans are being used both for additional diagnostic data and in lieu of adequate virus testing capability.

But CT usage, which can show a hazy lung infiltrate indicative of COVID-19, is, itself, not hazard-free. Beyond the risks from radiation exposure, heavily used machines can themselves become infected and spread the virus.

Faced with this difficult choice, some have cautioned against overuse, including the American College of Radiology

In March, the ACR advised that scans should not be the “first-line test to diagnose COVID-19.”

More recently, it added, that, “a normal chest CT does not mean a person does not have COVID-19 infection and an abnormal CT is not specific for COVID-19 diagnosis,” stressing to Bloomberg that, “clearly, locally constrained resources may be a factor in such decision-making.”

And on April 8, a consensus statement from the Fleischner Society on imaging for COVID-19 patients was published jointly in the journals Radiology and Chest.

The report advised that chest imaging is indicated in patients with COVID-19 who have worsening respiratory status and also for patients with moderate to severe features of COVID-19 regardless of COVID-19 test results — or in pre-test situations, according to an RSNA release.

At issue is that the scans will typically show a less-than-specific lung reaction.

“The lung only has so many ways it reacts to injury,” Dr. Ella Kazerooni, chair of the American College of Radiology’s thoracic imaging panel, told Bloomberg.

Basically, she advised that if clinical presentations suggest COVID-19, scans won't add much. But “if you think clinically they’ve got something else, then there’s a reason to do chest X-ray or CT.”

However, not all concur with this more conservative approach to scanning.

Mt. Sinai Health System radiologist Dr. Adam Bernheim, who has now analyzed hundreds of COVID-19 CT scans, told the news agency that he finds that the “rounded gray and white spots at the outer edge of the lung” are “very atypical.”

He described these spots as “clear enough that you can see through it, but it’s kind of hazy.”

And even at Mt. Sinai, which has available testing, the scans have proved helpful, he noted.

When scanning patients with COVID-19 is in order, extreme caution should be used to fight against the spread of infection.

The ACR advises that “appropriate infection control procedures should be followed before scanning subsequent patients.”

In addition, it suggests that “facilities may consider deploying portable radiography units in ambulatory care facilities for use when CXRs are considered medically necessary,” noting that, “the surfaces of these machines can be easily cleaned, avoiding the need to bring patients into radiography rooms.”