Posted on Mar 27, 2020
We spoke with Barbara L McComb, MD, FACR, Associate Professor of Radiology, Emeritus at the Mayo Clinic and reading radiologist for DocPanel, to understand how and when medical imaging is being used to evaluate patients for signs of Coronavirus Disease COVID-19.
From how patterns of other conditions compare to signs of COVID-19 to advice for patients being tested for the disease, Dr. McComb shares the latest on the role of imaging in Coronavirus diagnosis.
[DocPanel] How are medical imaging tests being used to diagnose Coronavirus Disease COVID-19?
The Centers for Disease Control and Prevention (CDC) recommends viral testing from the upper or lower respiratory tract as the reference standard for making a definitive diagnosis of COVID-19.
Chest x-rays and CT scans, traditional imaging tools used to evaluate the lungs, are not currently recommended to screen for COVID-19 pneumonia in the U.S. However, these imaging studies are being used in the U.S and globally as discriminatory elements in conjunction with the clinical examination and results of viral testing (when tests are available). Nuclear medicine ventilation studies are not recommended by the American College of Radiology (ACR) in the present environment. CT scans have greater sensitivity than chest x-rays for early-stage pneumonias and have been reported to be abnormal in some patients with negative viral testing or x-ray results but clinical findings still of high concern for COVID-19.
Imaging studies also continue to be performed for various reasons other than COVID-19, and certain findings have been reported to suggest COVID-19 in patients both with and without respiratory symptoms.
In certain clinical settings, trained physicians are also using bedside ultrasound to evaluate the lungs for findings that have been reported as compatible with COVID-19.
[DocPanel] What are some pros and cons of using medical imaging to diagnose COVID 19?
It is important to understand that chest x-rays and CT scans can both be normal early in the disease course, and that imaging findings, when present, are not specific for COVID-19 pneumonia. Similar findings can be seen in influenza pneumonia and several other viral infections as well as various non-infectious lung diseases. On the other hand, certain patterns of lung disease on imaging studies have been reported to be common in patients with COVID-19 and helpful in its diagnosis.
Findings atypical for COVID-19 may also suggest an alternative diagnosis. The use of ultrasound for lung imaging is not yet ubiquitous in the U.S., although some trained physicians are using it, as well as portable x-rays, for the bedside evaluation and triage of patients.
[DocPanel] What advice do you have for patients being tested for COVID 19 with medical imaging?
Please understand that physicians are gauging risk based on a patient’s history, symptoms, examination, and availability of viral testing, and using imaging sparingly in the U.S. during this pandemic. The CDC currently recommends viral testing even if imaging findings suggest a new diagnosis of COVID-19 pneumonia.
Radiology departments may choose to employ portable equipment to image certain patients, and they follow meticulous infection control policies to decontaminate equipment and rooms between patients. Various measures have the potential to cause delays, and patience will be welcomed by stressed medical personnel.
DocPanel is always committed to making sure every patient receives excellent care. If you would like an expert second opinion on your medical imaging scan from Dr. McComb or one of our other subspecialists, you can learn more here.