By Toby Gordon, ScD
Before the COVID-19 pandemic, there were many devastating viral, bacterial, and parasitic outbreaks in North America, most of which preceded the discovery of x-rays. But since Röentgen discovered x-rays in 1895, radiology has been an important discipline in the response to epidemics, not just for diagnosis but because radiologists are critical members of multidisciplinary care teams.
Epidemics that occurred before the benefits of radiologic science were identified by their clinical presentation and devastating effects. Malaria, a mosquito-borne illness, nearly wiped out the Jamestown colony in 1605. In 1633, smallpox brought by explorers decimated Native American populations farther north. In the 18th and 19th centuries, Americans endured recurring epidemics of yellow fever, cholera, typhoid, and scarlet fever, and tuberculosis was endemic, estimated to have killed 25 percent of colonial Americans. In these diseases, until the viral and bacterial causes were identified, diagnostic approaches were extremely limited.
Radiology’s first contribution to patient care in epidemics was in the diagnosis of tuberculosis with chest x-rays. Doctors were able to diagnose tuberculosis based on abnormal findings in the lungs that were consistent with the disease. By 1916, specific criteria for diagnosing pulmonary tuberculosis were developed by a group at the Trudeau Sanitorium, a medical treatment facility in the Adirondack Mountains. Of note, a “Radiographer’s Cottage” stands on the grounds of the Trudeau Sanatorium Historic District. At the time, there were lay radiologists, as there wasn’t professional certification until the American Board of Radiology was incorporated in 1934.
Radiology’s next epidemic-related contribution was in the influenza outbreak in 1918. Prior to that time, the potential value of chest x-rays for military use was diagnosing battlefield trauma. As U.S. troops began mobilizing for WWI, chest x-rays were also seen as potentially beneficial for screening soldiers for combat fitness, though that rarely actually happened. It was also thought that x-rays could be used in military training camps, since respiratory infections were expected to spread quickly in the close living quarters, and x-rays could be used to diagnose pneumonia.
Deployment of American troops headed to Europe included radiologists and state-of-the-art radiographic equipment for the medical corps. During the influenza outbreak in 1918, chest x-rays were available and the radiologic findings could be assessed to see if they were effective diagnostic tools. Doctors learned that tuberculosis could not always be differentiated from influenza, but regardless, radiologists were critical members of the medical team. This helped usher in collaborative multi-disciplinary approaches to clinical care with radiologists recognized as vital team members.
While epidemics of prior centuries were ameliorated without imaging, there were many major epidemics in the 20th century after the 1918 influenza epidemic including diphtheria, measles, polio, and HIV that relied on radiologic examination as part of diagnosis and care management. Radiation oncology became part of the armamentarium for treating carriers of diphtheria when other treatments were found to be ineffective and was used to treat Kaposi sarcoma lesions in patients with HIV/AIDS.
In 2010, in response to the 2009 H1N1 influenza outbreak, a team from the National Institutes of Health studied the role of radiology in pandemics in light of the technological advances in radiology such as CT (Mollura, 2010). From a clinical research perspective, they noted that the pathogenesis of influenza could be better understand with the ability to correlate pathology and radiology findings. With respect to the novel coronavirus, we are now seeing clinical reports on the radiologic appearance of COVID-19 in patients with the illness. The study of radiologic findings early in the U.S. outbreak noted the appearance of ground-glass opacification that can help identify the presence of COVID-19.
The contributions of radiologists today and in previous epidemics cannot be underestimated. The in-depth knowledge and expertise of diagnostic radiologists, the growth of radiology specialties, and the continuing development of technological advances enables rapid and more sophisticated diagnosis and earlier treatment. The next contribution of radiologists will be in preparedness planning for infection control for health care providers, surge capacity, and optimal patient management to mitigate exposure and viral spread. As in previous epidemics, radiologists will be indispensable members of the planning process to the benefit of patients and professional colleagues.
Toby Gordon is an associate professor at Johns Hopkins’ Carey Business School with a joint appointment at the university’s department of surgery in the school of medicine. She is the ABR’s first public board member.