Quantitative and longitudinal assessment of diffuse pulmonary parenchymal disease using lung ultrasound surface wave elastography - Project Summary/Abstract Early diagnosis and assessment of parenchymal lung disease, including interstitial lung disease (ILD)/pulmonary fibrosis, emphysema, and combined pulmonary fibrosis and emphysema (CPFE), is difficult as clinical presentation is variable/nonspecific, and functional evaluation to differentiate parenchymal from airway disease can be confusing, particularly in mixed obstructive/restrictive processes. We have developed a noninvasive lung ultrasound surface wave elastography (LUSWE) technique to measure the surface wave speed (SWS) of lungs quickly, safely, and noninvasively. In our extensive publications, we have demonstrated that SWS can be used for assessing and grading the severity of ILD. Based on these achievements, we will develop novel technology to analyze lung mass density and viscoelasticity in addition to SWS in this project. In a large and longitudinal clinical research study, we will develop LUSWE as a screening tool for early identification of lung fibrosis, quantitative assessment of emphysema and CPFE. Lung tissue is stiffened by fibrosis and the opposite occurs with the parenchymal destruction seen in emphysema. We will be able to provide quantitative viscoelastic data for assessing early ILD, emphysema, and CPFE. In Aim 1, we will enroll 50 patients with clinical pulmonary function tests and CT evidence of early/mild ILD. We will also enroll 50 healthy subjects as age/sex matched controls. In Aim 2, we will study 50 patients with CT based diagnosis of moderate and severe emphysema. In Aim 3, we will study 50 patients with CPFE. We will perform follow-up LUSWE testing for these patients during their routinely scheduled clinical appointments. We will rigorously evaluate LUSWE with CT for assessing these patients. CT is the clinical standard for lung assessment, but is costly, uses radiation, and typically is not performed serially. In contrast, LUSWE can be used frequently to noninvasively evaluate the changes in lung viscoelasticity with disease progression. CT will be used to establish baseline characteristics, and the patient will then have follow-up with LUSWE to track changes in lung viscoelasticity. Such a strategy will reduce potential radiation risk, mitigate the high costs associated with repeat CT, and improve patient management. Successful completion of this program will result in a novel, noninvasive, clinically efficient technique for assessing early ILD, emphysema, and CPFE and will also provide a tool for cost-effectively tracking disease progression.
