Ultrasound of the pediatric chest

Lung ultrasound and mediastinal retraction in children

The authors showed a case of left mediastinal retraction associated with massive left lung collapse suspected after easy visualization of the heart on all scans of the anterolateral left hemithorax. In fact, the figure shows that the apex of the ventricle was visible at the level of the pleural line in the left hemithorax (usually not visible due to pulmonary air artifacts).

Imaging recommendations and algorithms for pediatric tuberculosis: part 1-thoracic tuberculosis

Tuberculosis (TB) remains a global health problem and is the second leading cause of death from a single infectious agent, behind the novel coronavirus disease of 2019. Children are amongst the most vulnerable groups affected by TB, and imaging manifestations are different in children when compared to adults. TB primarily involves the lungs and mediastinal lymph nodes. Clinical history, physical examination, laboratory examinations and various medical imaging tools are combined to establish the diagnosis. Even though chest radiography is the accepted initial radiological imaging modality for the evaluation of children with TB, this paper, the first of two parts, aims to discuss the advantages and limitations of the various medical imaging modalities and to provide recommendations on which is most appropriate for the initial diagnosis and assessment of possible complications of pulmonary TB in children. Practical, evidence-based imaging algorithms are also presented.

Ultrasound-guided puncture into newborn rat brain

Since the brain structure of neonatal rats was not fully formed during the first 4 days, it cannot be detected using ultrasound. The objective of this study was to investigate the use of ultrasound to guide puncture in the normal coronal brain structure and determine the puncture depth of the location of the cortex, hippocampus, lateral ventricle, and striatum of newborn rats of 5-15 days. The animal was placed in a prone position. The specific positions of the cortex, hippocampus, lateral ventricle, and striatum were measured under ultrasound. Then, the rats were punctured with a stereotaxic instrument, and dye was injected. Finally, the brains of rats were taken to make frozen sections to observe the puncture results. By ultrasound, the image of the cortex, hippocampus, lateral ventricle, and striatum of the rat can be obtained and the puncture depth of the cortex (8 days: 1.02 ± 0.12, 10 days: 1.02 ± 0.08, 13 days: 1.43 ± 0.05), hippocampus (8 days: 2.63 ± 0.07, 10 days: 2.77 ± 0.14, 13 days: 2.82 ± 0.09), lateral ventricle (8 days: 2.08 ± 0.04, 10 days: 2.26 ± 0.03, 13 days: 2.40 ± 0.06), and corpus striatum (8 days: 4.57 ± 0.09, 10 days: 4.94 ± 0.31, 13 days: 5.13 ± 0.10) can be accurately measured. The rat brain structure and puncture depth changed with the age of the rats. Ultrasound technology can not only clarify the brain structure characteristics of 5-15-day-old rats but also guide the puncture and injection of the rat brain structure. The results of this study laid the foundation for the future use of ultrasound in experimental animal models of neurological diseases.

The Role of Ultrasound in the Diagnosis of Pulmonary Infection Caused by Intracellular, Fungal Pathogens and Mycobacteria: A Systematic Review

BACKGROUND

Lung ultrasound (LUS) is a widely available technique allowing rapid bedside detection of different respiratory disorders. Its reliability in the diagnosis of community-acquired lung infection has been confirmed. However, its usefulness in identifying infections caused by specific and less common pathogens (e.g., in immunocompromised patients) is still uncertain.

METHODS

This systematic review aimed to explore the most common LUS patterns in infections caused by intracellular, fungal pathogens or mycobacteria.

RESULTS

We included 17 studies, reporting a total of 274 patients with M. pneumoniae, 30 with fungal infection and 213 with pulmonary tuberculosis (TB). Most of the studies on M. pneumoniae in children found a specific LUS pattern, mainly consolidated areas associated with diffuse B lines. The typical LUS pattern in TB consisted of consolidation and small subpleural nodes. Only one study on fungal disease reported LUS specific patterns (e.g., indicating "halo sign" or "reverse halo sign").

CONCLUSIONS

Considering the preliminary data, LUS appears to be a promising point-of-care tool, showing patterns of atypical pneumonia and TB which seem different from patterns characterizing common bacterial infection. The role of LUS in the diagnosis of fungal disease is still at an early stage of exploration. Large trials to investigate sonography in these lung infections are granted.

Diagnostic accuracy of lung ultrasound for transient tachypnea: a meta-analysis

OBJECTIVE

The objective of this meta-analysis was to study the diagnostic value of lung ultrasound (LUS) for transient tachypnea of the newborn (TTN).

METHODS

Embase, Cochrane Library, PubMed, Web of Science, and Google Scholar were searched, and the last search date was October 31, 2020. Studies on the diagnostic accuracy of pulmonary ultrasound for transient tachypnea were included. The quality assessment of the included study was assessed using the Diagnostic Accuracy Studies-2 tool. A meta-analysis was performed using Meta-Disc 1.4. A random-effects model was used and subgroup analysis was carried out to identify possible sources of heterogeneity.

RESULTS

A total of 378 articles were retrieved and nine studies with 3239 patients were included in the present meta-analysis. The overall quality of the included studies was moderate to high. The result of threshold analysis shows that there was no threshold effect. However, there was a significant heterogeneity caused by non-threshold effects in the included studies. A random-effects model was used. The pooled sensitivity, specificity, PLR and NLR were 0.55 (95% CI: 0.51-0.58), 0.98 (95% CI: 0.98-0.99), 58.30 (95% CI: 14.05-241.88) and 0.28 (95% CI: 0.18-0.43). The pooled DOR and AUC were 689.12 (95% CI: 68.71 to 6911.79) and 0.994. The results of subgroup analysis showed that the LUS diagnostic criteria and gold standard might be responsible for heterogeneity. Choosing "DLP combined with B line" as the diagnostic standard of LUS and choosing CXR as the gold standard could significantly improve the diagnostic performance of LUS.

CONCLUSION

LUS is a promising method to diagnose TTN. Only DLP is not enough to diagnose TTN, while DLP combined with B-line has good diagnostic performance.

Ultrasound-Guided Selective Bronchial Intubation: A Feasibility Study in Pediatric Animal Model

Objective

Selective one-lung ventilation used to optimize neonatal and pediatric surgical conditions is always a demanding task for anesthesiologists, especially during minimally invasive thoracoscopic surgery. This study aims to introduce an ultrasound-guided bronchial intubation and exclusion technique in a pediatric animal model.

Methods

Seven rabbits were anesthetized and airway ultrasound acquisitions were done.

Results

Tracheal tube progression along the trachea to the right bronchus and positioning of the bronchial blocker in the left bronchus were successfully done with consistent ultrasound identification of relevant anatomical structures.

Conclusion

The study provided a new application of ultrasound in airway management. More advanced experimental studies are needed since this technique has the potential for translation to pediatric anesthesia.

The Key Role of Lung Ultrasound in the Diagnosis of a Mature Cystic Teratoma in a Child with Suspected Difficult to Treat Pneumonia: A Case Report

To date, the diagnosis of mediastinal teratoma and mediastinal masses relies on the use of chest X-ray and CT. Lung and thoracic ultrasound is becoming increasingly used in the diagnosis and follow-up of many lung and thoracic diseases. Here, we report the case of a mature cystic teratoma in which the performance of lung ultrasound allowed to speed up the diagnostic workup and to provide the indication for the execution of CT of the thorax allowing the diagnosis.

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

Thoracic ultrasound is radiation-free, easily available, portable modality with added advantage of real-time assessment. It is useful in mediastinal lesions and peripheral lung, pleural and chest wall masses. Not only is it a valuable modality in differentiating solid from cystic lesion, it can also depict internal architecture without the use of contrast material. The added advantages of its use in children are the lack of ionizing radiation, and no need for sedation or general anesthesia in most cases. Although it has its limitations with a longer learning curve, it can act as a second-line modality to chest radiograph and adjunctive modality to CT in cases of a thoracic mass in a child.

Ten Years of Pediatric Lung Ultrasound: A Narrative Review

Lung diseases are the most common conditions in newborns, infants, and children and are also the primary cause of death in children younger than 5 years old. Traditionally, the lung was not thought to be a target for an ultrasound due to its inability to penetrate the gas-filled anatomical structures. With the deepening of knowledge on ultrasound in recent years, it is now known that the affected lung produces ultrasound artifacts resulting from the abnormal tissue/gas/tissue interface when ultrasound sound waves penetrate lung tissue. Over the years, the application of lung ultrasound (LUS) has changed and its main indications in the pediatric population have expanded. This review analyzed the studies on lung ultrasound in pediatrics, published from 2010 to 2020, with the aim of highlighting the usefulness of LUS in pediatrics. It also described the normal and abnormal appearances of the pediatric lung on ultrasound as well as the benefits, limitations, and possible future challenges of this modality.

Necrotizing pneumonia in children: Chest computed tomography vs. lung ultrasound

BACKGROUND

The utilization of contrast-enhanced computed tomography (CT) of the chest for the diagnosis of necrotizing pneumonia (NP), a complication of community-acquired pneumonia, is controversial because of the inherent ionizing radiation involved. Over the past few years, the growing availability of bedside Lung Ultrasound (LUS) devices has led to increased use of this nonionizing imaging method for diagnosing thoracic pathology, including pneumonia.

OBJECTIVE

The objectives of this study were as follows: first, to compare the performance of LUS vs. CT in the identification of certain radiological signs of NP, and second, to determine whether LUS could replace CT in the diagnosis of NP.

MATERIALS AND METHODS

We compared retrospectively the CT and LUS images of 41 patients between 2005 and 2018 in whom at least one contrast-injected chest CT scan and one LUS had been undertaken fewer than 7 days apart.

RESULTS

Pleural effusions were demonstrated almost systematically (100% on CT vs. 95.8% on LUS). Visualization of septations in pleural effusions was clearly superior on LUS (20.4% on CT vs 62.5% on LUS). Concerning the detection of necrosis, we observed a strong correlation between LUS and the gold-standard CT (95.8% on LUS vs. 93.7% on CT). Parenchymal cavities were more easily detected on CT than on LUS (79.1 vs. 35.4%).

CONCLUSION

LUS has shown to be as effective as CT in the diagnosis of NP. The use of CT in patients with NP could be limited to the detection of complications such as bronchopleural fistulae in unfavorably evolving diseases.

Pediatric lung ultrasonography: current perspectives

Ultrasonography (US) is the workhorse of pediatric imaging; however, lung US is only a recently developed application. US of the lung is based predominantly on the imaging of chest wall-air-fluid interfaces. In this review, we summarize the available literature on applications of lung US in neonatal as well as pediatric care. We describe the imaging appearance of various commonly encountered pathologies including pneumonia and respiratory distress syndrome, among others, and provide illustrative images. Finally, we describe the limitations of the technique that are essential knowledge for radiologists, critical care physicians, sonographers and technologists attempting to use lung US effectively for diagnosis and management.

Pediatric Lower Respiratory Tract Infections: Imaging Guidelines and Recommendations

Lower respiratory tract infection (LRTI) remains a major cause of morbidity and mortality in children. Various organisms cause LRTI, including viruses, bacteria, fungi, and parasites, among others. Infections caused by 2 or more organisms also occur, sometimes enhancing the severity of the infection. Medical imaging helps confirm a diagnosis but also plays a role in the evaluation of acute and chronic sequelae. Medical imaging tests help evaluate underlying pathology in pediatric patients with recurrent or long-standing symptoms as well as the immunocompromised.

Usefulness of Lung Ultrasound in Paediatric Respiratory Diseases

Respiratory infection diseases are among the major causes of morbidity and mortality in children. Diagnosis is focused on clinical presentation, yet signs and symptoms are not specific and there is a need for new non-radiating diagnostic tools. Among these, lung ultrasound (LUS) has recently been included in point-of-care protocols showing interesting results. In comparison to other imaging techniques, such as chest X-ray and computed tomography, ultrasonography does not use ionizing radiations. Therefore, it is particularly suitable for clinical follow-up of paediatric patients. LUS requires only 5-10 min and allows physicians to make quick decisions about the patient's management. Nowadays, LUS has become an early diagnostic tool to detect pneumonia during the COVID-19 pandemic. In this narrative review, we show the most recent scientific literature about advantages and limits of LUS performance in children. Furthermore, we discuss the major paediatric indications separately, with a paragraph fully dedicated to COVID-19. Finally, we mention potential future perspectives about LUS application in paediatric respiratory diseases.

Lung Ultrasound in Pediatrics and Neonatology: An Update

The potential role of ultrasound for the diagnosis of pulmonary diseases is a recent field of research, because, traditionally, lungs have been considered unsuitable for ultrasonography for the high presence of air and thoracic cage that prevent a clear evaluation of the organ. The peculiar anatomy of the pediatric chest favors the use of lung ultrasound (LUS) for the diagnosis of respiratory conditions through the interpretation of artefacts generated at the pleural surface, correlating them to disease-specific patterns. Recent studies demonstrate that LUS can be a valid alternative to chest X-rays for the diagnosis of pulmonary diseases, especially in children to avoid excessive exposure to ionizing radiations. This review focuses on the description of normal and abnormal findings during LUS of the most common pediatric pathologies. Current literature demonstrates usefulness of LUS that may become a fundamental tool for the whole spectrum of lung pathologies to guide both diagnostic and therapeutic decisions.

Point-of-Care Ultrasound Assists in Rapid Diagnosis of T-cell Lymphoblastic Lymphoma in a Young Boy

T-cell lymphoblastic lymphoma (T-cell LBL) is an uncommon diagnosis for acute dyspnea in pediatric emergencies. This case details a 13-year-old boy presenting to the ED with dyspnea, who was diagnosed with T-cell LBL. It was a unique presentation in which there was no obvious mediastinal mass on the examination or primary imaging. As a safe and cost-effective modality for a patient that was too unstable to transfer to the radiology department for computed tomography, point-of-care ultrasound (POCUS) was useful in the patient’s rapid assessment for suspected pericardial and pleural effusion. This case highlights the advantage of early utilization of POCUS for pediatric patients with dyspnea. 

Point of care diaphragm ultrasound in acute bronchiolitis: A measurable tool to predict the clinical, sonographic severity of the disease, and outcomes

BACKGROUND

The aim of this study was to evaluate diaphragmatic parameters in bronchiolitis patients and identify correlations between clinical and sonographic severity scores and outcomes to develop a more objective and useful tool in the emergency department.

METHODS

Children aged between 1 and 24 months and diagnosed with acute bronchiolitis were included in the study. The Modified Respiratory Distress Assessment Instrument (mRDAI) score was used to quantify the clinical severity of the disease. Lung ultrasound was performed and a bronchiolitis ultrasound score (BUS) was calculated. Diaphragm ultrasound was then performed and diaphragm thickness at the end of inspiration and expiration, thickening fraction, diaphragm excursion (EXC), inspiratory slope (IS), expiratory slope (ES), and total duration time of the respiratory cycle were measured.

RESULTS

There were 104 patients evaluated in this study. The mRDAI score and BUS had a significant positive correlation. There was a positive correlation between IS and respiratory rate at admission. As the clinical score increased, IS, ES, and EXC measurements rose and they were positively correlated. Values of IS, ES, and EXC were higher in the moderate-severe group than the mild group for both mRDAI and BUS scores. Inspiratory slope values were correlated with the length of stay in the hospital.

CONCLUSION

Values of IS and ES were correlated with clinical and sonographic severity scores. Moreover, IS was a good predictor of outcome. Diaphragm ultrasound appears to be an objective and useful tool to help the physician make decisions regarding the evaluation and management of bronchiolitis.

Point-of-care lung and diaphragm ultrasound in a patient with spinal muscular atrophy with respiratory distress type 1

Spinal muscular atrophy with respiratory distress type 1 (SMARD1, OMIM #604,320), is a rare autosomal recessive disease resulting from degeneration of motor neurons in the anterior horns, which leads irreversible diaphragmatic palsy and progressive distal symmetrical muscular weakness. Respiratory distress is the main symptom and is severe, rapidly progressive, and frequently requiring invasive ventilation. Despite diaphragm being one of the target organ of the disease, no specific study has been done using ultrasound.We report diaphragm and lung ultrasound findings of a 13-month-old girl affected by SMARD1 (homozygosis c.1540G > A mutation in IGHMPB2 gene) with respiratory failure requiring permanent mechanical ventilation since birth and we discuss the role of diaphragmatic and lung ultrasound in this category of patients and its clinical implications.

Lung Ultrasound: Its Findings and New Applications in Neonatology and Pediatric Diseases

Lung ultrasound has become increasingly used in both adult and pediatric populations, allowing the rapid evaluation of many lung and pleura diseases. This popularity is due to several advantages of the method such as the low cost, rapidity, lack of ionizing radiation, availability of bedside and repeatability of the method. These features are even more important after the outbreak of the SARS-CoV-2 pandemic, given the possibility of recognizing through ultrasound the signs of interstitial lung syndrome typical of pneumonia caused by the virus. The purpose of this paper is to review the available evidence of lung ultrasound (LUS) in children and its main applications in pediatric diseases.

Mature cystic teratoma of anterior mediastinum in a 4-month-old infant: a rare case report

Teratomas of anterior mediastinum are rare tumors and are often slow growing, asymptomatic and detected incidentally on chest imaging. We report, a rare case of an anterior mediastinal teratoma occurring in early childhood. A 4-month-old male infant presented to the pediatric unit of our hospital with a 2-week history of a progressive difficulty in breathing and stridor. He had received several courses of oral and intravenous antibiotics for a clinical diagnosis of pneumonia. The baby started to show social smile and hold his head fairly steady. Chest radiography and chest ultrasound revealed a cystic anterior mediastinal mass which was confirmed by a contrasted chest CT. An ultrasound-guided trucut biopsy of the mass was performed and histopathology showed mature cystic teratoma. Surgical removal of the mass was done with excellent post-operative outcome. Occurrence of a mature cystic anterior mediastinal teratoma is uncommon in early infancy. Early and complete surgical resection offers the best possible prognosis.

Lung Ultrasonography: An Emerging Practice

Objective:

Sonography of the chest has traditionally been focused on chest wall and pleural space. Over time, clinicians have developed a practice of bedside lung ultrasonography (LUS) to supplement physical examination. In the wake of the SARS-COV-2 (COVID-19) pandemic, clinicians have increasingly turned to LUS as a tool to assess a patient’s condition.

Methods:

A literature search was performed using Google Scholar with access to articles through a major Midwestern university.

Results:

Computed tomography (CT) and radiographs are not always available in all treatment centers. While LUS may be limited, it is important to correlate findings with compatible imaging modalities. This review summarizes lung pathologies and the sonographic appearance of lung abnormalities.

Conclusions:

Radiology professionals have largely questioned the practice and findings of LUS. However, now, as the most qualified experts in the use of ultrasound, sonographers and radiologists have a duty to be educated in the use of LUS.

Lung ultrasound in outpatient approach to children with suspected COVID 19

BACKGROUND

Children with COVID 19 infection (CV19) generally have a mild disease whose main symptoms are fever and cough. Dyspnoea and hypoxemia are rarely reported and few data are available on the frequency and extent of lung involvement in children with CV19. In addition, due to the limited availability of diagnostic tests in Italy during the pandemic period and the relative reliability of the test results, the diagnostic suspicion of CV19 infection in most of the children was difficult to confirm. The aim of this study is to evaluate if lung ultrasound (LUS) was able to highlight typical interstitial lung lesions in children with persistent cough and suspected CV19, providing corroborating evidence of CV19 infection.

METHODS

We retrospectively analysed the data of 32 children who came consecutively to our outpatient observation in the period between March 1st and April 30th, 2020 because of the presence of persistent cough for at least 3 days and with suspected CV19. All the children undergone clinical examination, oximetry measurement and LUS.

RESULTS

Twenty over thirty-two children had US lesions compatible with the presence of CV19, many of them without clinical signs of respiratory distress. LUS is much more sensitive than clinical examination to detect lung injury in children with suspected CV19.

CONCLUSION

In the absence of reliable, highly sensitive diagnostic tests or when nasal swab is unworkable or there are too many requests to be performed quickly due to the pandemic, LUS should be used in children with persistent cough for whom a CV19 is suspected because it can highlight undiagnosed interstitial lung lesions and reinforce the diagnostic suspicion of CV19 This approach can be very useful in outpatient settings and in areas with limited medical resources such as developing countries.

The use of lung ultrasound compared to chest X-ray to diagnose pneumothorax following the Nuss procedure for pectus excavatum repair in children

BACKGROUND

Pectus Excavatum is the most common deformation of the skeletal chest wall, and the Nuss procedure is used to correct this deformation. Residual pneumothorax is a frequent postoperative complication after thoracoscopy. Primary aim of this prospective observational study was to compare the level of agreement among readers using lung ultrasound and chest X-ray.

METHODS

This was an inter-reader single-center prospective observational agreement study for lung ultrasound and chest X-ray. Three lung ultrasound evaluations were performed at the end of surgery in the operating room by two Consultant Anesthesiologist (A1 and A2) and by a medical student (A3). Chest X-ray was interpreted by a consultant Radiologist (R1) and a pool of 11 radiologists (collectively named R2). Cohen's kappa was used to evaluate the level of agreement between the two imaging techniques.

RESULTS

Sixty-eight pediatric patients were included in the study. The overall agreement among (A = Anesthesiologist) A1, A2, A3, (R = Radiologist) R1, and R2 in assessing pneumothorax was fair (k = 0.32; 95% CI 0.21-0.40). The stratified analysis showed moderate inter-reader agreement among lung ultrasound readers A1, A2, and A3 (k 0.58; 95% CI 0.44-0.71), as opposed to the fair agreement found among chest X-ray readers R1 and R2 (k = 0.39; 95% CI 0.18-0.60).

CONCLUSIONS

Our results support the use of lung ultrasound to diagnose pneumothorax after Nuss procedure. We found that the inter-reader accuracy was better with ultrasound compared to X-ray at our institution.