VALUE OF TRANSTHORACIC ULTRASONOGRAPHY IN DIAGNOSIS OF PULMONARY EMBOLISM

Abstract

Background: the diagnosis of pulmonary embolism (PE) is still a problem especially at emergency units. challenges remain regarding efficient, appropriate, and safe imaging methods for the diagnosis of suspected pulmonary embolism. Aim of the study: is to determine the diagnostic value of transthoracic ultrasonography (TUS) in patients with pulmonary embolism .Patients and methods: cross sectional study was conducted at Chest Department, Zagazig University Hospitals in the period from May 2017 to November 2017. The study was carried out on 48 patients clinically suspected PE. At the begining, TUS was performed by a chest physician, subsequently for definitive diagnosis computed tomography pulmonary angiography (CTPA) was performed to all cases as a reference method. Other diagnostic procedures were examination of serum d-dimer levels, echocardiography, and venous doppler ultrasonography of the legs. Diagnosis of PE was suggested if at least one typical pleural-based/subpleural wedge-shaped or round hypoechoic lesion with or without pleural effusion was reported by TUS. Presence of pure pleural effusion or normal sonographic findings were accepted as negative TUS for PE. RESULTS :PE was diagnosed in 31 patients. It was shown that TUS was true positive in 27 patients and false positive in 3 and true negative in 14 and false negative in 4. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of TUS in diagnosis of PE for clinically suspected patients were 87.09%, 82.3%, 90%, 77.7%, and 85.4%, respectively. CONCLUSIONS:TUS with a high sensitivity 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 tool in diagnosis of PE at bedside especially at emergency setting, for critically ill and immobile patients, facilitating immediate treatment decision .
Keywords: Chest ultrasonography, hypoechoic shadow, pulmonary embolism.