Mankind is now dealing with a new infection of uncertain origin. COVID-19 infection causes severe pneumonia, which is accompanied by fever and dry cough. As of March 17, 2020, the COVID-19 coronavirus was registered in 182,406 people worldwide (of whom 7,154 died). The World Health Organization (WHO) classifies an outbreak of a new coronavirus as a pandemic. 79,433 infected people have already recovered, although there is currently no specific antiviral treatment (data from the Public Health Center of the Ministry of Health of Ukraine).
As of March 17, seven laboratory-confirmed cases of COVID-19 (including one fatal) were recorded in Ukraine. The Cabinet of Ministers of Ukraine announced a three-week quarantine in the country on March 11 to prevent the spread of the virus, as a number of other states have done.
Radiation Diagnosis of Coronavirus Pneumonia: Contraindications
Therefore, methods of diagnosing a new coronavirus infection are of particular importance. X-rays and CT scans are important to assess the severity and development of this infection. Therefore, radiologists should be aware of the signs of infection visible in the images. At the same time, radiologists are the first to fall into the risk group of infection through contact with patients suspected of infection.
However, radiological diagnostic methods should be used only when the benefits outweigh the adverse effects of ionizing radiation on patients’ health. The American College of Radiology recommends that the following factors be considered when using radiography when diagnosing COVID-19 coronavirus infection:
- The US Department of Health and Human Services’ Centers for Disease Control and Prevention does not currently recommend chest radiography or computed tomography (CT) for the diagnosis of COVID-19. Viral tests remain the only accurate method of diagnosis. Confirmation by viral tests is necessary even if X-rays or CT scans show the presence of COVID-19.
- For the initial diagnosis of suspected coronavirus-19, it is recommended that samples be taken and examined from the upper respiratory tract (nasopharyngeal and oropharyngeal smears) or from the lower respiratory tract, if available for examination.
- In general, COVID-19 chest radiographs are inaccurate and reflect the presence of other infections, including influenza, H1N1, SARS, and MERS coronaviruses. The height of the flu season, which is dominated by COVID-19, limits CT accuracy.
Accordingly, the American College of Radiology recommends:
- Do not use CT for primary diagnosis of coronavirus-19.
- Moderate use of CT for already hospitalized patients with severe symptoms with special clinical indications for CT. Appropriate anti-infective procedures should be performed before examining subsequent patients.
- Medical facilities can deploy portable X-ray machines in outpatient facilities if there is a medical need for a chest x-ray. The surfaces of these devices are easy to clean, which eliminates the need for patients to come to X-ray rooms.
- Radiologists should be aware of the signs of COVID-19 infection seen on CT scans to be able to detect them in patients who have had CT scans for other reasons.
Safety of radiologists
During X-ray examinations, healthcare professionals should pay special attention to precautions against infection.
COVID-19 coronavirus infection is spread by airborne droplets, but there is no reliable data on whether it is transmitted through contact with infected surfaces or objects. According to research, the greatest danger of spreading the virus by droplets — at a distance of 91.44 cm. However, the drops can fall at a distance of up to 183 cm from the source.
A study of 254 therapist who came in contact with coronavirus SARS (2003, China) showed that precautions against airborne transmission of the virus are quite effective.
WHO recommendations (March 2020) provide for the protection of the respiratory tract with a standard medical mask (except for medical procedures using aerosols). Additionally, the Centers for Disease Control and Prevention recommends protection with N95 or higher levels of masks during close contact with patients in whom Coronavirus-19 is confirmed or diagnosed. The face of the patient being transported to the radiography department should also be covered with a surgical mask.
Doctors are advised to wear protective equipment, such as: disposable insulating suit with liquid protective properties, disposable gloves that cover the palms to the cuffs of the suit, goggles and a mask on top of the glasses.
After each contact with a patient suspected of being infected with the COVID-19 virus, the surfaces of the CT and MRI equipment, the non-invasive ultrasound probe, the mouse and the control panel keyboard should be disinfected.
Disinfection should be carried out either with soap and water, or a disinfectant of low or medium degree (bactericidal detergent iodophoric solution; ethyl alcohol or isopropyl alcohol). Radiology departments should contact equipment suppliers to determine the safest disinfectant for each item of equipment.
In addition to cleaning and disinfecting rooms where a patient with a suspected or confirmed coronavirus has been present, the CT or radiography room should be ventilated before scanning the next patient. Ventilation of health care facilities is an important measure to prevent airborne transmission of the virus.
- ACR Recommendations for the use of Chest Radiography and Computed Tomography (CT) for Suspected COVID-19 Infection // American College of Radiology.
- Coronavirus (COVID-19) Outbreak: What the Department of Radiology Should Know// Journal of the American College of Radiology (JACR).
- Coronavirus infection COVID-19 // Public Health Centre of the Ministry of Health of Ukraine.
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