Chest sonography in the diagnosis of pulmonary embolism: a comparison with MRI angiography and ventilation perfusion scintigraphy.

AIM: To compare the diagnostic performance of chest sonography, MRI angiography and ventilation/perfusion intigraphy in pulmonary embolism (PE). METHOD: In a prospective clinical study, 55 patients (41 women, 14 men, age 23 - 91 years) with clinical signs of PE were investigated within 48 hours of the onset of symptoms. The final diagnosis was made by MRI angiography (reference method). RESULTS: PE was diagnosed in a total of 36 patients. Chest sonography revealed rounded or wedge-shaped hypoechoic lesions in 30 patients. On ventilation/perfusion (V/P) scintigraphy, 41 patients had positive V/P scans, but only 23 were of high probability. Chest ultrasound had a positive predictive value of 97 % to diagnose PE. The sensitivity, specificity, the negative predictive value and accuracy were 81 %, 84 %, 84 % and 82 %, respectively. As 18 patients had inconclusive scans, the diagnostic performance of ventilation/perfusion scintigraphy was poor. The positive predictive value, sensitivity and specificity were 58 %, 42 % and 91 %, respectively. Patients in whom PE was excluded mainly suffered from congestive heart failure, bronchopulmonary infections or pulmonary hypertension. CONCLUSION: A negative sonographic study cannot rule out PE with certainty. However, a chest sonography is of acceptable diagnostic value in patients with suspected PE and may be used as an adjunct or guide to more established methods.

Lung sonographic findings in patients with suspected pulmonary embolism.

PURPOSE: To assess the feasibility and diagnostic performance of lung transthoracic sonography in patients with suspected pulmonary embolism. METHOD: In a prospective clinical study we compared sonographic findings of the peripheral lung with various scintigraphic gradings and D-dimer plasma concentrations. One hundred and nineteen consecutive patients with clinical signs of pulmonary embolism were investigated within 24 hours of the onset of symptoms. RESULTS: Seventy patients with suspected pulmonary embolism (59%) had sonographic lesions, which were echo poor, homogeneous and rounded or wedge-shaped with a hyperechoic reflexion in the centre. Of the patients with high-probability scintigraphic scans 86% had such sonographic lesions as had 79% with intermediate, 64% with low-probability and 33% with normal scintigraphic scans. Of the patients with positive sonographic findings and normal or low-probability scans only a minority (14%) had negative D-dimer tests. CONCLUSION: We found a high rate of specific sonographic lesions in patients with suspected pulmonary embolism when investigating the peripheral lung with ultrasound.