Discriminative Ability of Dynamic Chest Radiography to Identify Left Ventricular Dysfunction

Abstract

Background: Dynamic chest radiography (DCR) produces sequential radiographs within a short examination time. It is also inexpensive and only uses a low dose of radiation. Because of the lack of reports of evaluating cardiac function using DCR in humans, we investigated its discriminative ability for left ventricular (LV) dysfunction in a study cohort. Methods and Results: We analyzed the DCR pixel values of 4 circular regions of interest (ROIs) in the hearts of 61 patients with cardiovascular disease and 10 healthy volunteers. We evaluated the relationship between changes in pixel value in the heart and the LV ejection fraction (LVEF) by echocardiography. We constructed receiver operating characteristic (ROC) curves to evaluate whether the percent change in pixel value (%∆pixel value) could be used to identify patients with reduced LVEF. A total of 21 patients had reduced LVEF (LVEF <50%), and 40 had preserved LVEF (LVEF ≥50%). The correlation between LVEF and %∆pixel value in each ROI was significant, and the area under the ROC curve of the %∆pixel values for identifying patients with reduced LVEF was satisfactory (0.808–0.827) in 3 ROIs where the entire circular area was within the cardiac shadow. Conclusions: LV dysfunction can be detected by changes in the pixel value on DCR.