Background: Pulmonary thromboembolism (PTE) remains under-diagnosed fatal
disease at emergency units suggesting the need for alternative, easy, and noninvasive
bedside diagnostic approaches.
Objectives: To determine the diagnostic role of gray-scale and color Doppler transthoracic
ultrasonography (TUS) in patients with PTE.
Patients and Methods: Blinded to 64 multi-detectors CT pulmonary angiography
(MDCTPA) examination as a gold standard, 60 patients with clinically suspected
PTE underwent gray-scale and then color Doppler TUS examination. Results were
compared and diagnostic accuracy of TUS was assessed.
Results: Forty patients proved to have PTE by MDCTPA. TUS showed typical
lesions in 33 patients with the mean of 2 lesions per patient. Most lesions were hypoechoic,
wedge- shaped, and pleural- based and the majority (80%) was located in the
lower lobes. Consolidation with little perfusion was detected by Color Doppler ultrasound
in 97% of lesions. Isolated central PTE was significantly higher in TUS
negative patients. For gray –scale TUS, sensitivity, specificity, positive and negative
predictive values and accuracy were 82%, 90%, 94%, 72%, and 85%. Meanwhile the
sensitivity, specificity, positive and negative predictive values and accuracy of color
Doppler TUS were 80%, 95%, 97%, 70% and 87%, respectively.
Conclusion: TUS is a reliable diagnostic bedside test for PTE in critically ill and
immobile patients. Adding color Doppler to gray–scale TUS increases the specificity
and accuracy and consequently the confidence in the diagnosis of peripheral pulmonary
infarctions and differentiates them from other pulmonary lesions that allow
initiation of anticoagulants.