Correlation between Remote Dielectric Sensing and Chest X-Ray to Assess Pulmonary Congestion

Abstract

Background: Chest X-ray is a practical tool to semi-qualify pulmonary congestion. Remote dielectric sensing (ReDS) is a recently introduced, non-invasive, electromagnetic energy-based technology to quantify pulmonary congestion without expert technique. We compared these two modalities to clarify appropriate clinical situations for each modality. Methods: ReDS and chest X-ray measurements were prospectively performed on admission in consecutive hospitalized patients with cardiovascular diseases. In the chest X-ray, the congestive score index (CSI) was calculated blindly by two independent experts and averaged. CSIs were correlated with ReDS values. Results: A total of 458 patients (76 (69, 82) years old, 267 men, and 130 heart failure) were included. Median ReDS value was 28% (25%, 33%). There was a mild correlation between ReDS values and CSIs (r = 0.329, p < 0.001). The correlation between ReDS values and CSIs became stronger in the heart failure cohort (r = 0.538, p < 0.001). In patients with mild congestion (ReDS <35%), ReDS values, instead of CSI, stratified the degree of congestion. In patients with severe congestion (ReDS >35%), both modalities stratified the degree of congestion. Conclusions: Both chest X-ray and ReDS are useful for assessing severe pulmonary congestion, whereas ReDS would be preferred to chest X-ray in stratifying the severity of mild pulmonary congestion.

Prognostic impact of residual pulmonary congestion assessed by remote dielectric sensing system in patients admitted for heart failure

“…ReDS system is a novel, non‐invasive, and quantitative modality to evaluate pulmonary congestion by measuring the dielectric properties of the lung. The ability of this technology to quantify pulmonary congestion has been validated by comparing with other conventional modalities, whereas its prognostic impact has remained uncertain 19–21 . Our study is the first to demonstrate that lung water content assessed using ReDS technology during HF hospitalization had an impact on the prognosis in HF patients.…”

“…In this study, we excluded patients with obvious lung diseases, but some factors that could not be excluded, such as undiagnosed and untreated pulmonary or pleural disease, might have affected our results 22 . In cases with patients with extremely large or small amount of the fat or muscle mass in the chest wall, ReDS values might be affected 23 …”

Presence of Pleural Effusion in the Assessment of Remote Dielectric Sensing

“…This technology is non-invasive, easy and quick to measure, and does not require expert technicians. In the literature to date, various validation studies have been conducted that compare the ReDS system with other modalities that are clinically applied to assess pulmonary congestion, including chest computed tomography, right heart catheterization, lung ultrasound, chest X-ray, and plasma B-type natriuretic peptide levels [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. ReDS values and PAWP are known to be moderately correlated [ 7 , 12 ], as also confirmed in this study.…”

“…The remote dielectric sensing (ReDS) system is a new technology that non-invasively estimates lung fluid volume based on electromagnetic energy and displays a percentage within one minute on a monitor [ 5 ]. Its ability has been validated in comparison with other modalities, including computed tomography, right heart catheterization, chest X-ray, lung ultrasound, and plasma B-type natriuretic peptide levels [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. ReDS is approved by the FDA and CE for lung fluid monitoring, as well as in other countries, including Japan.…”

How to Assess the Degree of Pulmonary Congestion in Patients with Congestive Heart Failure

“…Chest X-ray and lung ultrasound are clinically practical tools for distinguishing severe pulmonary congestion [6]. ReDS values and modalities showed moderate correlations, especially in patients with severe pulmonary congestion [7]. ReDS technology could stratify the degree of lung fluid amount in patients with mild pulmonary congestion by displaying the quantified ReDS values, whereas these modalities could not stratify those with mild pulmonary congestion.…”