Quantitative Ultrasound for Interstitial Lung Diseases

ABSTRACT The objective is to demonstrate feasibility of LQUS in human patients for assessing the severity of pulmonary edema due to heart failure and of idiopathic pulmonary fibrosis. The long-term goal is to develop LQUS to monitor pulmonary edema and fibrosis with high sensitivity and specificity in real time, in vivo, in humans. In patients with lung diseases such as pulmonary edema or fibrosis, diagnosis and monitoring is done using chest X-ray and CT scanning, or invasive pulmonary function tests. However, these imaging modalities expose patients to ionizing radiation, have high inter-observer variability, and are expensive and impractical for frequent routine monitoring. Pulmonary function tests are effort dependent and coughing and shortness of breath may affect the results. Therefore, the need for an in-vivo, point-of-care, real-time, non-ionizing, and noninvasive quantitative monitoring of pulmonary edema is great. Conventional ultrasound remains challenging in the lung because the air-filled alveoli cause multiple scattering. Vertical artifacts called B-lines can be observed with various lung diseases. Although they have some diagnostic relevance, these artifacts are operator- and system-dependent. More critically, they are qualitative and not specific. A need exists for the development of QUS biomarkers of the lung, to monitor chronic conditions leading to interstitial lung diseases such as cardiogenic pulmonary edema and idiopathic pulmonary fibrosis. We propose to develop new LQUS-based metrics of the lung parenchyma. We will develop methods to mitigate chest-wall effects and optimize the data acquisition for humans (Aim1), and apply LQUS methods in-vivo in humans with HF (Aim2) and with pulmonary fibrosis (Aim3).