Technique, radiation safety and image quality for chest X-ray imaging through glass and in mobile settings during the COVID-19 pandemic

Abstract

The COVID-19 pandemic in 2020 has led to preparations within our hospital for an expected surge of patients. This included developing a technique to perform mobile chest X-ray imaging through glass, allowing the X-ray unit to remain outside of the patient’s room, effectively reducing the cleaning time associated with disinfecting equipment. The technique also reduced the infection risk of radiographers. We assessed the attenuation of different types of glass in the hospital and the technique parameters required to account for the glass filtration and additional source to image distance (SID). Radiation measurements were undertaken in a simulated set-up to determine the appropriate position for staff inside and outside the room to ensure occupational doses were kept as low as reasonably achievable. Image quality was scored and technical parameter information collated. The alternative to imaging through glass is the standard portable chest X-ray within the room. The radiation safety requirements for this standard technique were also assessed. Image quality was found to be acceptable or borderline in 90% of the images taken through glass and the average patient dose was 0.02 millisieverts (mSv) per image. The majority (67%) of images were acquired at 110 kV, with an average 5.5 mAs and with SID ranging from 180 to 300 cm. With staff positioned at greater than 1 m from the patient and at more than 1 m laterally from the tube head outside the room to minimise scatter exposure, air kerma values did not exceed 0.5 microgray (µGy) per image. This method has been implemented successfully.

Implementing a Novel Through-Glass Chest Radiography Technique for COVID-19 Patients: Image Quality, Radiation Dose Optimization, and Practical Considerations

“… 10 Brady and colleagues reported that 30 through-glass radiographs were assessed by 2 readers: one scored 70% of them as acceptable quality while the other scored 90% of them acceptable. 11 However, they did not compare these images to conventionally obtained radiographs. Thus, it cannot be determined if image quality was equivalent.…”

COVID-19 Associated Pneumonia

“…In addition, the low radiation dose involved in radiography compared to CT makes it an ideal imaging modality for follow-up purposes. 41 In COVID-19 cases, the appearance of lung changes on chest radiography is dependent on the stage of disease. Initially, chest radiographs are usually insensitive to mild changes in patients with early disease; however, at later or more advanced stages, radiograph abnormalities are usually apparent.…”

Cost benefit analysis of portable chest radiography through glass: Initial experience at a tertiary care centre during COVID-19 pandemic

“…The Radiological Society of North America (RSNA) scientific expert review panel proposed an innovative method of obtaining portable or bedside chest radiograph through glass walls of isolation rooms on March 18, 2020 [15] . This technique was subsequently shown to be able to produce diagnostic quality radiographs with no significant increase in radiation to the patient [16] , [17] , [18] , [19] . With some refinements, our hospital quickly adopted this technique.…”