Contrast-enhanced ultrasound of pediatric lungs

Abstract

In addition to radiography, ultrasound (US) has long proved to be a valuable imaging modality to evaluate the pediatric lung and pleural cavity. Its many inherent advantages, including real-time performance, high spatial resolution, lack of ionizing radiation and lack of need for sedation make it preferable over other imaging modalities such as CT. Since the introduction of ultrasound contrast agents (UCAs), contrast-enhanced ultrasound (CEUS) has become a valuable complementary US technique, with many well-established uses in adults and evolving uses in children. Lung CEUS applications are still not licensed and are performed off-label, although the added value of CEUS in certain clinical scenarios is increasingly reported. The limited evidence of CEUS in the evaluation of pediatric lungs focuses primarily on community-acquired pneumonia and its complications. In this clinical setting, CEUS is used to confidently and accurately diagnose necrotizing pneumonia and to delineate pleural effusions and empyema. In addition to intravenous use, UCAs can be administered directly into the pleural cavity through chest catheters to improve visualization of loculations within a complex pleural effusion, which might necessitate fibrinolytic therapy. The purpose of this paper is to present the current experience on pediatric lung CEUS and to suggest potential additional uses that can be derived from adult studies.

Pediatric lung ultrasonography: current perspectives

“…Free dispersion of microbubbles within the effusion indicates communicating loculi, which is a sign of successful therapy. Similarly, this helps to confirm catheter location and patency [ 42 ].…”

Ultrasonography in the Evaluation of Pediatric Chest “Masses”: When to Consider?

“…Infarct appears as non-enhancing tissue. 10 However, thoracic ultrasound is complex and requires experience. It is imperative to be aware of the normal findings and mimics on pediatric thoracic ultrasound.…”

“…Newer advances in ultrasound like CEUS can help in better microvascular assessment and help in differentiating tumor showing heterogeneous enhancement with early washout from atelectasis which shows uniform marked and sustained enhancement. Infarct appears as non‐enhancing tissue 10 …”

Contrast‐Enhanced Ultrasound of the Chest in Children and Adolescents

“…9,11 Enhancement with early washout of contrast material from an intrathoracic mass would suggest a neoplastic lesion while early homogeneous enhancement with late-phase washout would be more indicative of infection. 6,11,15 Active hemorrhage would be depicted as a pool-like leakage of contrast agent with intraparenchymal bleeding. Extra-parenchymal bleeding would manifest as jet-like contrast extravasation.…”

“…[2][3][4][5][6][7][8] There is very little information in the literature regarding the use of CEUS in disorders of the pediatric chest: a single case series of 10 children with complicated pneumonia 9 ; a study of 13 children and adolescents with solid malignancies undergoing antiangiogenic therapy that included 2 patients with pleural-based tumors 10 ; and a review article summarizing the current pediatric and adult literature and suggesting additional potential applications of CEUS of the chest in children along with several illustrative examples. 11 The primary hypothesis of this study is that CEUS has higher sensitivity and specificity for diagnosis of chest disorders in the pediatric population, resulting in higher diagnostic confidence when compared to conventional US imaging. The utility of CEUS as a diagnostic tool was investigated in children and adolescents with a variety of chest abnormalities, by comparing its diagnostic accuracy and reliability (inter-rater agreement and confidence level) to that of conventional US imaging.…”