Bedside 3D diagnostic imaging in ICU ABSTRACT Imaging in intensive care unit (ICU) is an integral part of patient management. Bedside chest x-ray radiograph (CXR) is the most often requested imaging examination for the commonly encountered pulmonary diseases in the ICU and is also routinely used for the assessment of various catheters and tubes. In many ICU traditional practice mandates a daily CXR for all ICU patients. It enables examination of the critically ill patients at the point- of-care. In the current COVID-19 pandemic, physicians also use bedside CXR for follow-up of patients with COVID pneumonia. The global market for mobile digital radiography was estimated to be over USD 2 billion in 2017, growing at an annual rate of 7%. However, as a 2D imaging modality the diagnostic accuracy of CXR is limited by structural/anatomical overlaps. Superposition of devices, tubes and catheters further reduce the diagnostic quality. Interpretation of CXR is challenging not only for intensive care physicians but also for radiologist. Computed tomography (CT) is the current gold standard for diagnosis of cardiopulmonary diseases. However, CT uses a significantly higher radiation exposure to the patients and the staff, and has a higher cost compared to CXR. With the exception of a few special purpose systems, CT is in bulky and heavy and is not mobile. We propose to address this unmet clinical need of better diagnosis at the ICU by developing a mobile digital tomosynthesis scanner to provide 3D imaging capability at the patient bedside. Digital tomosynthesis (DTS) overcomes the problem of anatomical overlap by collecting multiple low-dose x-ray images from different angles. It improves the visualization and diagnosis compared to CXR and uses a significantly lower dose and has a lower cost compared to CT. It is now widely used clinically for detection of breast cancer, lung disease and orthopedic imaging. The use of DTS is expected to improve the decision process in the ICU, but due to limitations of the current technologies, no portable DTS has been developed. The proposed device is enabled by multiple innovations including a novel carbon nanotube (CNT) x-ray source array technology invented by our team. We have developed a proof-of-concept DTS and demonstrated its utility in patient imaging studies. The goal of this project is to develop a mobile DTS device specifically for ICU. The technology is protected by a strong patent portfolio. New IP’s will be developed during this project to strengthen the protection. The device is expected to require the Pre-market Notification (510(K)) approval from the FDA. The Specific Aims of this project are: (1) Designing a mobile DTS for bedside 3D imaging (R61 Phase); (2) Validating the system performance by image simulation and experiment (R61 Phase); and (3) Prototype construction and validation (R33 Phase).