Validation of a Recently Developed Fluoroscopic Video Analysis Workstation (Radwisp™) for the Reliable Diagnosis of Acute Pulmonary Thromboembolism.

Objective Radwisp™ is a fluoroscopic video analysis workstation recently developed to evaluate pulmonary circulation, thereby obviating the need for contrast medium or breath-holding. This study validated Radwisp as a diagnostic tool for acute pulmonary embolism (APE) and evaluated its potential utility in patients with symptoms of suspected APE. Methods The study included 10 patients (mean age, 69±16 years old) who were admitted to our hospital for suspected APE based on symptoms and physical examination findings between January 2020 and April 2021. Contrast-enhanced computed tomography (CT) and cineradiography, based on standard radiographs for the creation of a Radwisp image, were performed on the same day. Of the 10 cases of suspected APE, 7 were definitively diagnosed by CT with APE, and 3 were definitively diagnosed as not having APE. Fifty physicians (25 cardiologists and 25 residents) were blinded to patient information and CT images and asked to diagnose the presence of APE based solely on the Radwisp images. Results A total of 250 diagnoses were made by cardiologists and 250 by residents. Among the cardiologists, the sensitivity and specificity of the Radwisp-based analysis were 91% and 48%, respectively, and the positive and negative predictive values were 80% and 69%, respectively. Among the residents, the sensitivity and specificity were 88% and 35%, respectively, and the positive and negative predictive values were 76% and 55%, respectively. Conclusion This study showed an initial validation of Radwisp for diagnosing APE, revealing a high sensitivity but not yet achieving a high specificity. Further studies with a larger number of cases are needed to thoroughly evaluate the diagnostic performance.