Diagnostic validity of thoracic ultrasound in the assessment of pulmonary embolism

Abstract

Background: To determine the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of thoracic ultrasound (TUS) in patients with moderate to high clinical suspicion of pulmonary embolism (PE). Twenty-five patients with moderate or high clinical suspicion of PE were enrolled in a prospective study. The patients’ ages were 20 to 50 years (mean age = 36 years). They were evaluated by TUS and standard contrast-enhanced CT pulmonary angiography (CTPA). Results: In comparison to and in correlation with CTPA, TUS was found true positive in 12 patients (48%), false positive in one patient (4%), true negative in eight patients (32%), and false negative in four patients (8%), with an overall sensitivity (75%), specificity (89%), positive predictive value (92%), negative predictive value (67%), and accuracy (80%). Conclusion: TUS with its high specificity and diagnostic accuracy is a noninvasive, widely available, cost-effective method which can be rapidly performed. A negative TUS study cannot rule out PE with certainty, but positive TUS findings with moderate/high suspicion for PE may prove a valuable bedside tool in the diagnosis of PE especially for critically ill and immobile patients, facilitating their immediate treatment.