Current Ultrasound Technologies and Instrumentation in the Assessment and Monitoring of COVID-19 Positive Patients.

Qian, Xuejun; Wodnicki, Robert; Kang, Haochen; Zhang, Junhang; Tchelepi, Hisham; Zhou, Qifa

Since the emergence of the COVID-19 pandemic in December of 2019, clinicians and scientists all over the world have faced overwhelming new challenges that not only threaten their own communities and countries but the world at large. These challenges have been enormous and debilitating, as the infrastructure of many countries including developing ones had little, or no resources to deal with the crisis. Even in developed countries like Italy, health systems have been so inundated by cases that health care facilities became oversaturated and could not accommodate the unexpected influx of patients to be tested. Initially, resources were focused on testing to identify those who were infected. When it became clear that the virus mainly attacks the lungs by causing parenchymal changes in the form of multifocal pneumonia of different levels of severity, imaging became paramount in the assessment of disease severity, progression, and even response to treatment. As a result, there was a need to establish protocols for imaging of the lungs in these patients. In North America, the focus was on chest x-ray and CT as these are widely available and accessible at most health facilities. However, in Europe and China, this was not the case and a cost-effective and relatively fast imaging modality was needed to scan a large number of sick patients promptly. Hence, ultrasound found its way into the hands of Chinese and European physicians and has since become an important imaging modality in those locations. Ultrasound (US) is a highly versatile, portable, and inexpensive imaging modality which has application across a broad spectrum of conditions and in this way is ideally suited to assess the lungs of COVID-19 patients in the ICU. This bedside test can be done with little to no movement of the patients from the unit which keeps them in their isolated rooms, thereby limiting further exposure to other health personnel. This paper presents a basic introduction to COVID-19 and the use of ultrasound for lung imaging. It further provides a high-level overview of the existing ultrasound technologies which are driving development in current and potential future US imaging systems for lung, with a specific emphasis on portable and 3D systems.