Detection of peripheral embolic consolidations using contrast-enhanced ultrasonography in patients with no evidence of pulmonary embolism on computed tomography: A pilot study.

AIM: To investigate the value of B-mode imaging and contrast-enhanced ultrasonography (CEUS) in patients with clinically suspected pulmonary embolism (PE) but no evidence of central PE on CT.

METHODS: Between May 2004 and February 2015, we included in this retrospective study 19 patients with a risk profile for PE according to their Wells' score, sonographic patterns of peripheral embolic consolidations (EC) on B-mode-imaging and CEUS (ie, missing or inhomogeneous enhancement of the pleural lesions), and exclusion of central PE by CT within 1 week of CEUS.

RESULTS: On B-mode imaging, 19 pleural defects presented as hypoechoic. The shape of EC was round in 2, wedge-shaped in 12, polygonal in 3, and presented as atelectasis in 2 cases. On CEUS, 5 of the defects demonstrated, at the arterial and parenchymal phase, a lack of enhancement, and 14 showed an inhomogeneous (mixed) enhancement with wedge-shaped peripheral areas of no contrast enhancement. A second radiologic evaluation of the CT scans revealed PE in two patients and lesions suspicious for malignancy in two other patients.

CONCLUSIONS: Despite the lack of definite confirmation of peripheral and central PE on CT, peripheral pleural consolidations with no or inhomogeneous enhancement on CEUS, in combination with the risk profile for a PE, are highly suggestive of EC. If there is still some doubt, histologic confirmation is important to confirm EC and exclude malignancy. Thus, CEUS may close a potential diagnostic gap of small peripheral PE on CT. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:575-579, 2017.