Sonographic prediction of chronic lung disease in the premature undergoing mechanical ventilation

Lung ultrasound scores within the first 3 days of life to predict respiratory outcomes

BACKROUND

Lung ultrasound (LUS) is a rapid and simple method to evaluate preterm babies with respiratory distress. Lately, LUS has also been reported as an accurate predictor for bronchopulmonary dysplasia (BPD).

OBJECTIVES

The aim of the study was to investigate the relationship between the LUS scores within the first 3 days of life and respiratory outcomes including the need and the duration of invasive mechanical ventilation, and development of BPD.

METHODS

It was a retrospective observational study. Preterm infants younger than 32 weeks were included at an academic tertiary Neonatal Intensive Care Unit between 2018 and 2023. LUS was performed within the first 3 days. Each lung was divided into three regions and defined as a score of 0 to 3 points; the total score was obtained by adding the six regional scores. LUS scores were noted in two groups as the highest and lowest scores. Statistical analyses were done to predict respiratory outcomes.

RESULTS

Total 218 patients were enrolled; 40, 17, and 18 infants had mild, moderate, and severe BPD, respectively. BPD did not develop in 143 patients. Within the first 3 days, the highest and lowest LUS scores significantly predicted moderate-to-severe BPD (p < .001) (area under receiver operating characteristic [ROC] curve, 0.684-0.913; area under ROC curve 0.647-0.902; respectively). High LUS scores were also related with the need of mechanical ventilation (p < .001). There was not a significant correlation between the duration of mechanical ventilation and the LUS scores. Regression analysis revealed that the highest LUS scores within the first 3 days of life, sepsis, and the presence of hemodynamically significant patent ductus arteriosus (hsPDA) were significantly associated with the severity of BPD.

CONCLUSIONS

In preterm babies, the LUS scores were useful to predict BPD and the need of invasive ventilation in long term. However, it was not related with the length of invasive ventilation.

A scoping review of echocardiographic and lung ultrasound biomarkers of bronchopulmonary dysplasia in preterm infants

Despite recent improvements in neonatal care, moderate to severe bronchopulmonary dysplasia (BPD) is still associated with high mortality and with an increased risk of developing pulmonary hypertension (PH). This scoping review provides an updated overview of echocardiographic and lung ultrasound biomarkers associated with BPD and PH, and the parameters that may prognosticate their development and severity, which could be clinically helpful to undertake preventive strategies. A literature search for published clinical studies was conducted in PubMed using MeSH terms, free-text words, and their combinations obtained through appropriate Boolean operators. It was found that the echocardiography biomarkers for BPD, and especially those assessing right ventricular function, are reflective of the high pulmonary vascular resistance and PH, indicating a strong interplay between heart and lung pathophysiology; however, early assessment (e.g., during the first 1-2 weeks of life) may not successfully predict later BPD development. Lung ultrasound indicating poor lung aeration at day 7 after birth has been reported to be highly predictive of later development of BPD at 36 weeks' postmenstrual age. Evidence of PH in BPD infants increases risk of mortality and long-term PH; hence, routine PH surveillance in all at risk preterm infants at 36 weeks, including an echocardiographic assessment, may provide useful information. Progress has been made in identifying the echocardiographic parameters on day 7 and 14 to predict later development of pulmonary hypertension. More studies on sonographic markers, and especially on echocardiographic parameters, are needed for the validation of the currently proposed parameters and the timing of assessment before recommendations can be made for the routine clinical practice.

Lung Ultrasound for Predicting the Respiratory Outcome in Patients with Bronchopulmonary Dysplasia

OBJECTIVE

This study aimed to investigate the utility of lung ultrasound (LUS) with whole chest scanning for predicting respiratory outcomes in patients with bronchopulmonary dysplasia (BPD).

STUDY DESIGN

We performed a prospective observational study. Preterm infants of less than 32 weeks' gestational age requiring oxygen therapy at 28 days of life were included. LUS was performed on day 28, at 36 weeks' postmenstrual age, and at the time of discharge. Each lung was divided into three regions by the anterior and posterior axillary lines and received an LUS score of 0 to 3 points; the total score was obtained by adding the six regional scores. The classification of BPD was determined based on the National Institute of Child and Human Development. The outcomes of this study were the development of moderate-to-severe BPD and the need for home oxygen therapy (HOT).

RESULTS

We enrolled 87 patients; 39, 33, and 15 infants had mild, moderate, and severe BPD, respectively. The LUS score correlated with BPD severity and exhibited an improvement trend with time toward the point of discharge. LUS at 28 days of life predicted moderate-to-severe BPD with an area under the curve of 0.95 (95% confidence interval: 0.91-0.99) and HOT with an area under the curve of 0.95 (95% confidence interval: 0.81-1.0).

CONCLUSION

LUS with whole chest scanning is useful for predicting respiratory outcomes in patients with BPD, as well as for understanding BPD severity or clinical improvement trends.

KEY POINTS

· LUS predicts respiratory outcomes in patients with BPD.. · LUS indicates BPD severity.. · LUS can show clinical improvement with time..

A modified lung ultrasound score to evaluate short-term clinical outcomes of bronchopulmonary dysplasia

Background

Lung ultrasound (LUS) is a useful tool for assessing the severity of lung disease, without radiation exposure. However, there is little data on the practicality of LUS in assessing the severity of bronchopulmonary dysplasia (BPD) and evaluating short-term clinical outcomes. We adapted a LUS score to evaluate BPD severity and assess the reliability of mLUS score correlated with short-term clinical outcomes.

Methods

Prospective diagnostic accuracy study was designed to enroll preterm infants with gestational age < 34 weeks. Lung ultrasonography was performed at 36 weeks postmenstrual age. The diagnostic and predictive values of new modified lung ultrasound (mLUS) scores based on eight standard sections were compared with classic lung ultrasound (cLUS) scores.

Results

A total of 128 infants were enrolled in this cohort, including 30 without BPD; 31 with mild BPD; 23 with moderate BPD and 44 with severe BPD. The mLUS score was significantly correlated with the short-term clinical outcomes, superior to cLUS score. The mLUS score well correlated with moderate and severe BPD (AUC = 0.813, 95% CI 0.739–0.888) and severe BPD (AUC = 0.801, 95% CI 0.728–0.875), which were superior to cLUS score. The ROC analysis of mLUS score to evaluate the other short-term outcomes also showed significant superiority to cLUS score. The optimal cutoff points for mLUS score were 14 for moderate and severe BPD and 16 for severe BPD.

Conclusions

The mLUS score correlates significantly with short-term clinical outcomes and well evaluates these outcomes in preterm infants.

Application of ultrasonography in neonatal lung disease: An updated review

Lung disease is often life-threatening for both preterm and term newborns. Therefore, an accurate and rapid diagnosis of lung diseases in newborns is crucial, as management strategies differ with different etiologies. To reduce the risk of radiation exposure derived from the conventionally used chest x-ray as well as computed tomography scans, lung ultrasonography (LUS) has been introduced in clinical practice to identify and differentiate neonatal lung diseases because of its radiation-free characteristic, convenience, high accuracy, and low cost. In recent years, it has been proved that LUS exhibits high sensitivity and specificity for identifying various neonatal lung diseases. Here, we offer an updated review of the applications of LUS in neonatal lung diseases based on the reports published in recent years (2017 to present).

Meta-analysis of Lung Ultrasound Scores for Early Prediction of Bronchopulmonary Dysplasia

RATIONALE

Lung ultrasound scores (LUS) might be useful in monitoring neonates with chronic pulmonary insufficiency of prematurity and in predicting bronchopulmonary dysplasia (BPD). Given their ease of use, accuracy and lack of invasiveness, LUS have been the subject of several recent studies.

OBJECTIVE

We sought to clarify whether LUS provide an accurate and early (within the first two weeks of life) prediction of BPD in preterm infants of gestational age <32weeks.

METHODS

Systematic review and diagnostic accuracy meta-analysis following PRISMA-P, PRISMA and QUADAS guidelines. Studies designed to predict BPD in the first two weeks of life using LUS were selected. A classical LUS (calculated for 6 chest areas) and its extended version (eLUS, 10 chest areas) were tested.

RESULTS

Seven studies (1027 neonates) were meta-analyzed. LUS and eLUS showed good diagnostic accuracy in predicting BPD at 7 and 14 days of life (AUC 0.85-0.87, pooled sensitivity 70-80%, pooled specificity 80-87%). The diagnostic accuracy of LUS and eLUS did not differ at any timepoint (AUC difference always p >0.05). Repeating the analyses without outliers or with moderate-to-severe BPD as outcome yielded similar results. Meta-regressions showed that prenatal steroid prophylaxis and sex were not significant effect confounders.

CONCLUSIONS

LUS are accurate for early prediction of BPD and moderate-to-severe BPD, in an average population of preterm infants <32weeks' gestation. The diagnostic accuracy is similar for LUS and eLUS, so the use of the simpler score should be advocated. Registration. PROSPERO CRD42021233010.

Early lung ultrasound affords little to the prediction of bronchopulmonary dysplasia

OBJECTIVE

To test the hypothesis that lung ultrasound (LUS) performed in the first week of life would predict bronchopulmonary dysplasia (BPD). Secondary outcomes included the utility of LUS in predicting interim respiratory interventions.

DESIGN

A prospective observational cohort study in preterm infants born <28 weeks' gestation in the single tertiary statewide neonatal intensive care unit in Western Australia.

METHODS

A rigorous protocol for LUS acquisition on day 1, day 3-4, day 7, day 28 and 36 weeks' postmenstrual age (PMA) was implemented with blinded analysis using a modified, previously validated LUS score. BPD was defined by both recent National Institute of Child Health and Human Development categorical criteria and a continuous physiological variable using a modified Shift test.

RESULTS

Of the 100 infants studies, primary outcome data were available for the 96 infants, surviving to 36 weeks' PMA. In a univariate logistic regression analysis, LUS on days 3-4 and day 7 accurately predicted BPD (day 3-4 OR (95% CI)=1.54 (1.03 to 2.42), p=0.044; day 7 OR (95% CI)=1.66 (1.07 to 2.70), p=0.031). The predictive value of LUS was insignificant in a multivariate model in which gestational age was the dominant predictor. LUS accurately predicted interim respiratory outcomes including surfactant administration, duration of intubation and extubation to non-invasive support at 48 hours.

CONCLUSIONS

LUS in the first week of life predicted BPD. However, LUS offers little additive accuracy to current gestational age-based models.

TRIAL REGISTRATION NUMBER

ACTRN12617000208303.

Lung ultrasound predicts the development of bronchopulmonary dysplasia: a prospective observational diagnostic accuracy study

This study aimed to evaluate the predictive ability of lung ultrasound (LU) in the development of bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) infants. A total of 130 VLBW infants with gestational age < 32 weeks were included; LU was performed at days 1, 2, 3, 6, 9, 12, and 15 postnatally. We calculated the LU score by 12-region, 10-region, and 6-region protocols. The incidence of BPD according to the National Institutes of Health (NIH) 2001 definition and 2019 criteria was 38.5% and 64.6%, respectively. By 12-region and 10-region protocols, LU predicted BPD from the 9^th to 15^th days of life (DOLs) regardless of the criteria used, with an area under the curve (AUC) ranging from 0.826 (95% confidence interval (CI): 0.750-0.887) to 0.877 (95% CI: 0.807-0.928). According to the 2019 BPD definition, the LU score incorporated gestational age, and invasive mechanical ventilation >6 days predicted BPD on the 6^th DOL with an AUC of 0.862 (95% CI: 0.790-0.916). The 6-region protocol had significantly smaller AUC values on the 6^th and 9^th DOLs than the other two protocols.Conclusion: The 12-region and 10-region LU scoring protocols are superior to the 6-region protocol in the prediction of BPD. LU can predict the development of BPD from the 9^th to 15^th DOLs. With the addition of clinical variables, the earliest prediction time was the 6^th DOL. What is Known: • Bronchopulmonary dysplasia is the most common and adverse complication of prematurity. Recent four studies found that lung ultrasound score or findings predicted the development of bronchopulmonary dysplasia. What is New: • We present analysis by classical 6-region and the other two lung ultrasound score (10-region and 12-region) which include an assessment of the posterior lung to allow to understand what is the best score to be used. In addition, we explore whether LU-incorporated clinical variables could improve the predictive value for BPD.

Characterization of lung ultrasound imaging in preterm infants with bronchopulmonary dysplasia

BACKGROUND

Lung ultrasound (LUS) is a bedside technique that can be used on diagnosis and follow-up of neonatal respiratory diseases. However, there are rare reports on the ultrasound features of bronchopulmonary dysplasia (BPD) which is one of the most common chronic lung diseases in preterm infants.

OBJECTIVE

To describe the ultrasound features of different BPD levels, and to investigate the value of ultrasound in evaluating moderate-to-severe BPD.

METHODS

In this prospective cohort study, newborns of less than 37 weeks' gestational age in neonatal intensive care unit (NICU) were included. The LUS characteristics including pleural line, alveolar-interstitial syndrome (AIS), retrodiaphragmatic hyperechogenicity and diaphragmatic morphology were observed and recorded. The reliability of LUS in evaluating moderate and severe BPD were compared and calculated.

RESULTS

A total of 108 infants were enrolled in our study: 39, 24, 29, 16 infants had non, mild, moderate and severe BPD. The median(IQR) pleura thickness in the moderate-to-severe BPD group was 1.7(1.6-1.85) mm, which was thicker than that in the none-to-mild BPD infants (P <  0.001), meanwhile the proportions of rough pleural lines, diffuse AIS, retrodiaphragmatic hyperechogenicity, small cysts above the diaphragm and rough diaphragm in the moderate-to-severe BPD group were also higher than those in none-to-mild BPD group (86.7% vs 36.5, 57.8% vs 7.9%, 37.8% vs 0, 33.3% vs 0, P <  0.001). In evaluating moderate-to-severe BPD, rough pleura had 91.1% (95% confidence interval [CI]: 0.793-0.965) in sensitivity, 91.3% (95% CI: 0.797-0.966) in negative predictive value (NPV), and 66.7% (95% CI: 0.544-0.771) in specificity. Small cysts had 100% (95% CI: 0.941-1) in specificity, 100% (95% CI: 0.816-1) in PPV, and 37.8% in sensitivity (95% CI: 0.251-0.524). Rough diaphragm had 100% (95% CI: 0.943-1) in sensitivity, 100% (95% CI: 0.796-1) in PPV and 33.3% (95% CI: 0.211-0.478) in specificity.

CONCLUSIONS

Depending on its unique advantages such as convenient, no radiation and repeatable, LUS is a valuable imaging method in assessing the severity of BPD, especially in moderate and severe BPD.

Modern pulmonary imaging of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a complex and serious cardiopulmonary morbidity in infants who are born preterm. Despite advances in clinical care, BPD remains a significant source of morbidity and mortality, due in large part to the increased survival of extremely preterm infants. There are few strong early prognostic indicators of BPD or its later outcomes, and evidence for the usage and timing of various interventions is minimal. As a result, clinical management is often imprecise. In this review, we highlight cutting-edge methods and findings from recent pulmonary imaging research that have high translational value. Further, we discuss the potential role that various radiological modalities may play in early risk stratification for development of BPD and in guiding treatment strategies of BPD when employed in varying severities and time-points throughout the neonatal disease course.

Point-of-care lung ultrasound in neonatology: classification into descriptive and functional applications

Lung ultrasound (LUS) is the latest amongst imaging techniques: it is a radiation-free, inexpensive, point-of-care tool that the clinician can use at the bedside. This review summarises the rapidly growing scientific evidence on LUS in neonatology, dividing it into descriptive and functional applications. We report the description of the main ultrasound features of neonatal respiratory disorders and functional applications of LUS aiming to help a clinical decision (such as surfactant administration, chest drainage etc). Amongst the functional applications, we propose SAFE (Sonographic Algorithm for liFe threatening Emergencies) as a standardised protocol for emergency functional LUS in critical neonates. SAFE has been funded by a specific grant issued by the European Society for Paediatric Research. Future potential development of LUS in neonatology might be linked to its quantitative evaluation: we also discuss available data and research directions using computer-aided diagnostic techniques. Finally, tools and opportunities to teach LUS and expand the research network are briefly presented.

The application value of lung ultrasound findings in preterm infants with bronchopulmonary dysplasia

BACKGROUND

The purpose of this study was to investigate the association between ultrasound findings and preterm infants with bronchopulmonary dysplasia (BPD).

METHODS

Preterm infants with a gestation age of less than 28 weeks or birthweight less than 1,500 g admitted to the neonatal intensive care unit (NICU) in the Chengdu Women's & Children's Central Hospital from June 2018 to June 2019 were enrolled in the study and divided into 2 groups: the BPD group and the non-BPD group. All clinical data and lung ultrasound were retrospectively analyzed.

RESULTS

A total of 81 neonates (gestational age =29.71±2.27 weeks; birth weight =1,189.5±184.5 g) were enrolled in our center. The regression analysis showed that gestational age [odds ratio (OR) =0.57; 95% confidence interval (CI): 0.42-0.77, P=0.0002], birthweight (OR =0.99; 95% CI: 0.99-1.00, P<0.0001), mild asphyxia (OR =3.3; 95% CI: 1.24-8.74, P=0.0165), anemia (OR =4.43; 95% CI: 1.34-14.64, P=0.0146), blood transfusion (OR =3.68; 95% CI: 1.38-9.79, P=0.0090), respiratory failure (OR =6.58; 95% CI: 1.27-34.08, P=0.0486), heart failure (OR =6.58; 95% CI: 1.27-34.08, P=0.0248), and "debris" lung ultrasound findings (OR =21.82; 95% CI: 2.63-181.11, P=0.0043) were correlated with BPD.

CONCLUSIONS

BPD-related lung ultrasound findings can be a kind of imaging marker to diagnose BPD.

Pediatric lung ultrasound - pros and potentials

Lung ultrasound (US) cannot be considered a new diagnostic imaging technique anymore, with some articles dating back 50 years. The question that hovers over it recently is why it is still not widely accepted, like chest radiography. So, have we wasted a lot of time without using lung US, or are we wasting our time using lung US? The main goals of this article are to underline all the advantages, potentials and reasons to use lung US in everyday clinical practice, but also to address the main concerns linked to this imaging tool. From the standpoint of an experienced pediatric radiologist from a tertiary health care children's hospital who has been performing this examination for more than 10 years on a daily basis, this article also addresses the most common applications of lung US, such as detection of pneumonia and neonatal lung diseases.

Utility of lung ultrasound scanning in neonatology

The utility of point-of-care lung ultrasound in neonatology is rapidly expanding. This review summarises current evidence of a diagnostic, procedural and observational tool valuable in the management of newborns requiring intensive care. Approaching a patient, probe in-hand with focused clinical question is essential, and barriers to implication together with important research questions are explored.

Lung ultrasound score as early predictor of bronchopulmonary dysplasia in very low birth weight infants

BACKGROUND

Lung ultrasound (LU) has been widely used to diagnose and monitor acute lung diseases in neonates, but its role in chronic diseases has not been elucidated.

OBJECTIVE

We aim to describe the evolution of a lung ultrasound score (LU score) in very low birth weight infants (VLBWI) with and without bronchopulmonary dysplasia (BPD).

METHODS

We prospectively included 59 VLBWI and performed LU in the first 24 and 72 hours of life, and then weekly until 36 weeks´ postmenstrual age (PMA). We calculated the LU score as a semiquantitative score representing the aeration (0-3) in three different areas of each lung.

RESULTS

The non-BPD group (n = 38) had lower LU score at 1, 2, 3, 4, and 36 weeks' PMA than the BPD group: median score of 1 (0-4) vs 7 (3-10), P < .001; 0 (0-1) vs 7 (4-9), P < .001; 0 (0-1) vs 8 (7-11), P < .001; 0 (0-2) vs 9 (4-12), P < .001; 0 (0-0) vs 3 (0-6), P < .001. A LU score of 5 or above at 1 week of life predicted BPD with a sensitivity (Se) of 71%, specificity (Sp) 80%, area under the ROC curve (AUC) 0.8, and at 2 weeks of life with Se 74%, Sp 100%, and AUC 0.93. An LU score of 4 or above at 4 weeks predicted moderate-severe BPD (Se 100%, Sp 80%, and AUC 0.89).

CONCLUSION

In VLBWI without BPD, LU score increases during the first week of life and decreases thereafter, whereas among subjects with BPD, the LU score remains high until 36 weeks´ PMA. LU score can predict the diagnosis of BPD at 1 week and 2 weeks of life, and may predict moderate-severe BPD at 4 weeks of life.

Ultrasound in neonatal lung disease

Lung diseases in neonates can be life-threatening condition and may result in respiratory failure and death. Chest X-ray is a traditional diagnostic technique that results in radiation exposure to patients. Lung ultrasound is a user-friendly imaging technique that has been increasingly used in clinical practice in recent years and presents the advantages of real-time imaging and without radiation. Here we review the sonographic appearances of common neonatal lung diseases and present demonstration of typical cases.

Interstitial Lung Disease in Children Made Easier…Well, Almost

Interstitial lung disease (ILD) in pediatric patients is different from that in adults, with a vast array of pathologic conditions unique to childhood, varied modes of presentation, and a different range of radiologic appearances. Although rare, childhood ILD (chILD) is associated with significant morbidity and mortality, most notably in conditions of disordered surfactant function, with respiratory failure in 100% of neonates with surfactant protein B dysfunction and 100% mortality without lung transplantation. The authors present a summary of lung development and anatomy, followed by an organized approach, using the structure and nomenclature of the 2013 update to the chILD Research Network classification system, to aid radiologic diagnosis of chILD. Index radiologic cases with contemporaneous histopathologic findings illustrate a summary of recent imaging studies covering the full spectrum of chILD. chILD is best grouped by age at presentation from infancy (diffuse developmental disorders, lung growth abnormalities, specific conditions of unknown origin, surfactant dysfunction mutations) to later childhood (disorders of the normal host, disorders related to systemic disease processes, disorders related to immunocompromise). Appreciation of the temporal division of chILD into infant and later childhood onset, along with a sound understanding of pulmonary organogenesis and surfactant homeostasis, will aid in providing useful insight into this important group of pediatric conditions. Application of secondary lobular anatomy to interpretation of thin-section computed tomographic images is pivotal to understanding patterns of ILD and will aid in selecting and narrowing a differential diagnosis. ^©RSNA, 2017.

Neonatal lung ultrasound exam guidelines

Point-of-care ultrasound (POC-US) is increasingly used especially in emergency and critical-care medicine. It is focused, quick and does not expose patients to ionizing radiation. It encompasses all organ systems and has well-defined indications. Lung ultrasound (LUS) represents one of the most exciting applications in the field of POC-US. It is particularly important to emphasize the role of LUS in neonatology due to the specific pathology inherent in lung immaturity as well as in the particular sensitivity of neonates to repeated radiation exposure. One of the main barriers to the more extensive use of the ultrasound technology is a lack of efficient and attractive training solutions followed by the structured quality-check assurance. In an effort to help bridge this gap, based on the most current literature, we developed creative and intuitive neonatal LUS algorithms. We hope they can serve as a clinical imaging guidelines and a valuable complement to the history and physical exam.

Diagnosis of secondary pulmonary lymphangiectasia in congenital heart disease: a novel role for chest ultrasound and prognostic implications

BACKGROUND

Secondary pulmonary lymphangiectasia is a complication of congenital heart disease that results from chronic pulmonary venous obstruction.

OBJECTIVES

We aimed to evaluate the performance of chest ultrasound (US) in diagnosing secondary pulmonary lymphangiectasia and to review the clinical course of children with secondary pulmonary lymphangiectasia.

MATERIALS AND METHODS

Chest US was performed on 26 children with hypoplastic left heart syndrome, total anomalous pulmonary venous connection or cor triatriatum in a prospective observational study. Thirteen children had pulmonary venous obstruction (62% male; median age: 17 days old, range: 1-430 days old) and 13 children did not have obstruction (62% male; median age: 72 days old, range: 4-333 days old). US features of secondary pulmonary lymphangiectasia were documented and diagnostic performance was determined. Clinical course of patients with secondary pulmonary lymphangiectasia was reviewed.

RESULTS

Eleven of 13 (84.6%) patients in the obstructed group had a clinical and/or biopsy diagnosis of secondary pulmonary lymphangiectasia. Statistically significant chest US criteria for diagnosis were presence of irregular lung surface (likelihood ratio [LR] 6.8, 95% confidence interval [CI] 1.9-25.1), subpleural cystic appearing structures (LR 3.6, 95% CI 1.2-10.7), and combination of subpleural cystic appearing structures and surface irregularity together (LR 10.9, 95% CI 1.6-75.0). Seven of 11 (63.6%) patients with secondary pulmonary lymphangiectasia died during follow-up, the majority due to cardiopulmonary failure or complications.

CONCLUSION

Chest US is an accurate and reproducible bedside method for diagnosing secondary pulmonary lymphangiectasia in patients with pulmonary venous obstruction. These patients may have worse prognoses.

Imaging Bronchopulmonary Dysplasia-A Multimodality Update

Bronchopulmonary dysplasia is the most common form of infantile chronic lung disease and results in significant health-care expenditure. The roles of chest radiography and computed tomography (CT) are well documented but numerous recent advances in imaging technology have paved the way for newer imaging techniques including structural pulmonary assessment via lung magnetic resonance imaging (MRI), functional assessment via ventilation, and perfusion MRI and quantitative imaging techniques using both CT and MRI. New applications for ultrasound have also been suggested. With the increasing array of complex technologies available, it is becoming increasingly important to have a deeper knowledge of the technological advances of the past 5–10 years and particularly the limitations of some newer techniques currently undergoing intense research. This review article aims to cover the most salient advances relevant to BPD imaging, particularly advances within CT technology, postprocessing and quantitative CT; structural MRI assessment, ventilation and perfusion imaging using gas contrast agents and Fourier decomposition techniques and lung ultrasound.

Neonatal respiratory distress syndrome: Chest X-ray or lung ultrasound? A systematic review

BACKGROUND AND AIM

Neonatal respiratory distress syndrome is a leading cause of morbidity in preterm new-born babies (<37 weeks gestation age). The current diagnostic reference standard includes clinical testing and chest radiography with associated exposure to ionising radiation. The aim of this review was to compare the diagnostic accuracy of lung ultrasound against the reference standard in symptomatic neonates of ≤42 weeks gestation age.

METHODS

A systematic search of literature published between 1990 and 2016 identified 803 potentially relevant studies. Six studies met the review inclusion criteria and were retrieved for analysis. Quality assessment was performed before data extraction and meta-analysis.

RESULTS

Four prospective cohort studies and two case control studies included 480 neonates. All studies were of moderate methodological quality although heterogeneity was evident across the studies. The pooled sensitivity and specificity of lung ultrasound were 97% (95% confidence interval [CI] 94-99%) and 91% (CI: 86-95%) respectively. False positive diagnoses were made in 16 cases due to pneumonia (n = 8), transient tachypnoea (n = 3), pneumothorax (n = 1) and meconium aspiration syndrome (n = 1); the diagnoses of the remaining three false positive results were not specified. False negatives diagnoses occurred in nine cases, only two were specified as air-leak syndromes.

CONCLUSIONS

Lung ultrasound was highly sensitive for the detection of neonatal respiratory distress syndrome although there is potential to miss co-morbid air-leak syndromes. Further research into lung ultrasound diagnostic accuracy for neonatal air-leak syndrome and economic modelling for service integration is required before lung ultrasound can replace chest radiography as the imaging component of the reference standard.

Hyperpolarized 3He and 129Xe magnetic resonance imaging apparent diffusion coefficients: physiological relevance in older never- and ex-smokers

Noble gas pulmonary magnetic resonance imaging (MRI) is transitioning away from (3)He to (129)Xe gas, but the physiological/clinical relevance of (129)Xe apparent diffusion coefficient (ADC) parenchyma measurements is not well understood. Therefore, our objective was to generate (129)Xe MRI ADC for comparison with (3)He ADC and with well-established measurements of alveolar structure and function in older never-smokers and ex-smokers with chronic obstructive pulmonary disease (COPD). In four never-smokers and 10 COPD ex-smokers, (3)He (b = 1.6 sec/cm(2)) and (129)Xe (b = 12, 20, and 30 sec/cm(2)) ADC, computed tomography (CT) density-threshold measurements, and the diffusing capacity for carbon monoxide (DLCO) were measured. To understand regional differences, the anterior-posterior (APG) and superior-inferior (∆SI) ADC differences were evaluated. Compared to never-smokers, COPD ex-smokers showed greater (3)He ADC (P = 0.006), (129)Xe ADCb12 (P = 0.006), and ADCb20 (P = 0.006), but not for ADCb30 (P > 0.05). Never-smokers and COPD ex-smokers had significantly different APG for (3)He ADC (P = 0.02), (129)Xe ADCb12 (P = 0.006), and ADCb20 (P = 0.01), but not for ADCb30 (P > 0.05). ∆SI for never- and ex-smokers was significantly different for (3)He ADC (P = 0.046), but not for (129)Xe ADC (P > 0.05). There were strong correlations for DLCO with (3)He ADC and (129)Xe ADCb12 (both r = -0.95, P < 0.05); in a multivariate model (129)Xe ADCb12 was the only significant predictor of DLCO (P = 0.049). For COPD ex-smokers, CT relative area <-950 HU (RA950) correlated with (3)He ADC (r = 0.90, P = 0.008) and (129)Xe ADCb12 (r = 0.85, P = 0.03). In conclusion, while (129)Xe ADCb30 may be appropriate for evaluating subclinical or mild emphysema, in this small group of never-smokers and ex-smokers with moderate-to-severe emphysema, (129)Xe ADCb12 provided a physiologically appropriate estimate of gas exchange abnormalities and alveolar microstructure.

Role of transabdominal ultrasound of lung bases and follow-up in premature neonates with respiratory distress soon after birth

Background:

Chest radiography has been the traditional method of diagnostic evaluation of patients of hyaline membrane disease (HMD). Lung sonography (USG) has been lately explored as an alternative modality.

Aims:

To explore the application of transabdominal USG of lung bases (TASL) in the evaluation of HMD in premature neonates with respiratory distress soon after birth.

Settings and Design:

Tertiary care institutional setup. Study duration–18 months. Follow-up–variable, up to 1 month. Prospective descriptive study.

Materials and Methods:

Eighty-eight consecutive patients admitted in the neonatal intensive care unit (NICU) with gestational age <32 weeks having respiratory distress within 6 h of birth were enrolled. The diagnosis of HMD was made if the patient had negative gastric shake test and/or suggestive chest radiograph. TASL was performed in all patients within the first 24 h of life and biweekly subsequently. USG was interpreted as normal, HMD pattern, or broncho-pulmonary dysplasia (BPD) pattern. Biweekly follow-up was done for patients showing HMD till normalization of the sonographic HMD pattern, development of the sonographic BPD pattern, or death/discharge of the neonate from the hospital.

Results and Conclusions:

TASL showed 85.7% sensitivity, 75% specificity, 88.88% positive predictive value, and 69.2% negative predictive value for the diagnosis of HMD. The abnormal sonographic findings on day 14 had 94.1% accuracy for prediction of eventual occurrence of clinical BPD. TASL is complementary to chest radiograph in the diagnosis of HMD. It is also useful for the early prediction of BPD with the potential of reducing the cumulative radiation dose to these neonates.

Lung ultrasonography of pulmonary complications in preterm infants with respiratory distress syndrome

AIM

To evaluate the diagnostic possibilities of lung ultrasonography (LUS) in detecting pulmonary complications in preterm infants with respiratory distress syndrome (RDS).

MATERIAL AND METHODS

A prospective study included 120 preterm infants with clinical and radiographic signs of RDS. LUS was performed using both a transthoracic and a transabdominal approach within the first 24 h of life, and, after that, follow-up LUS examinations were performed. In 47 detected pulmonary complications of RDS (hemorrhage, pneumothorax, pneumonia, atelectasis, bronchopulmonary dysplasia), comparisons between LUS and chest X-ray (CXR) were made. Also, 90 subpleural consolidations registered during LUS examinations were analysed. Statistical analysis included MANOVA and discriminant analysis, t-test, confidence interval, and positive predictive value.

RESULTS

In 45 of 47 instances the same diagnosis of complication was detected with LUS as with CXR, indicating a high reliability of the method in premature infants with RDS. The only two false negative findings concerned partial pneumothorax. The positive predictive value of LUS was 100%. A statistically significant difference of LUS findings between the anterior and posterior lung areas was observed in both right and left hemithoraces.

CONCLUSIONS

LUS enables the detection of pulmonary complications in preterm infants with RDS and has the potential to reduce the number of CXRs. The specific guidelines for its use should be provided in a more extensive study.

Lung ultrasound in respiratory distress syndrome: a useful tool for early diagnosis

BACKGROUND

Respiratory distress syndrome (RDS) is a severe form of neonatal respiratory distress which occurs almost exclusively in premature infants. At present, the diagnosis is based on radiological findings and clinical course. Lung ultrasound in RDS has not yet been fully assessed.

OBJECTIVES

The aim of the study was to define the ultrasonographic appearance of RDS and evaluate its clinical relevance.

METHODS

Lung sonography was performed in 40 newborn infants with radiological and clinical signs of RDS (mean gestational age 27.2 +/- 2.7 weeks, mean birth weight 1,057 +/- 361 g) and in 15 preterm infants without RDS (mean gestational age 30.4 +/- 3.4 weeks, mean birth weight 1,775 +/- 669 g).

RESULTS

In all the studied infants with RDS, lung ultrasound consistently showed generalized alveolar-interstitial syndrome (echographic 'white lung'), pleural line abnormalities (small subpleural consolidations, thickening, irregularity and coarse appearance) and an absence of areas with a normal pattern ('spared areas'). When presented simultaneously, these signs identify RDS with a sensitivity and specificity of 100%.

CONCLUSIONS

We found that lung ultrasound is a reliable tool in the diagnosis of RDS. We speculate that it may be considered as a screening method for the diagnosis of RDS, and for early administration of surfactant in preterm infants with respiratory distress.

The 'double lung point': an ultrasound sign diagnostic of transient tachypnea of the newborn

BACKGROUND

Transient tachypnea of the newborn (TTN) is a mild form of neonatal respiratory distress which early in its course needs to be differentiated from other severe respiratory disorders. At present the diagnosis is based on radiological findings and clinical course. Lung sonography in TTN has not yet been assessed.

OBJECTIVES

The aim of the study was to define the ultrasonographic appearance of TTN and evaluate its clinical relevance.

METHODS

Lung sonography was performed in 32 newborn infants with radiological and clinical signs of TTN within the first hour after birth and the findings were compared with those of 60 normal infants, 29 with respiratory distress syndrome, 6 with pneumonia, 5 with pulmonary hemorrhage and 5 with atelectasis.

RESULTS

In the infants with TTN, lung sonography showed a difference in lung echogenicity between the upper and lower lung areas. There were very compact comet-tail artifacts in the inferior fields while these were rare in the superior fields. We designated this finding the 'double lung point' and it was not observed in healthy infants, infants with respiratory distress syndrome, actelectasis, pneumothorax, pneumonia, or pulmonary hemorrhage. Sensitivity and specificity of the double lung point was 100% for the diagnosis of TTN.

CONCLUSION

We found lung sonography reliable for the early diagnosis of TTN. We suggest that it should become the first approach for imaging of neonatal respiratory distress although further prospective studies with good blinding need to be performed.

Pediatric chest ultrasound

Ultrasound examination of the thorax can be quite rewarding in children, because their unique thoracic anatomy provides many acoustic windows into the chest. With only a modest effort, chest ultrasonography can provide many clinically relevant answers, without the radiation exposure from CT, or the need for sedation sometimes required for CT and MR imaging.

The value of ultrasound examination of the lungs in predicting bronchopulmonary dysplasia

BACKGROUND

Bronchopulmonary dysplasia (BPD) is one of the most serious complications of neonatal mechanical ventilation. Early diagnosis may influence treatment options such as early steroid administration.

OBJECTIVE

To assess the role of US of the lungs in predicting the development of BPD in infants with hyaline membrane disease (HMD) and to determine the earliest possible age at which the diagnosis of BPD could be made with certainty.

PATIENTS AND METHODS

Consecutive premature newborn infants requiring assisted ventilation during 1997-1998 who were admitted because of HMD were studied prospectively. US of the lungs was performed within 3 days of birth and three times a week thereafter until discharge from the neonatal intensive care unit. Each patient was also clinically and radiographically evaluated for the presence or absence of BPD at day 28 of life. Lung US scans were correlated with the development of BPD.

RESULTS

Retrodiaphragmatic hyperechogenicity (RH) was initially observed in 28 of the 36 patients with HMD, but resolved completely in 24 (96%) of 25 infants who had an uncomplicated clinical course. In eight of the ten infants who developed BPD, RH persisted. Day 9 was the earliest day where persistence of abnormal RH was observed with the highest predictor values for the development of BPD.

CONCLUSIONS

Lung US is a valuable technique for predicting the development of BPD.

The aurora sign: an ultrasonographic sign suggesting parenchymal lung disease

The objective of this study was to clarify the cause and clinical significance of a large number of ring-down artefact (RA) observed on the dorsal side of the right hepatic lobe on abdominal ultrasound (US). 2000 abdominal US examinations were evaluated to investigate the frequency and number of RA behind the right lobe of the liver. In this study, RA observed by subcostal or intercostal US were described as the "aurora sign" when they were numerous. US findings were correlated with high resolution CT or three-dimensional CT of the right lung base. Experimental study was also performed to investigate the mechanism of the aurora sign. The results were as follows. (1). Aurora sign was noted in 43 patients. In 37 of these 43 patients (86.0%), chest CT or plain radiography revealed diffuse interstitial changes in the right lower lung field. Three-dimensional CT of the lung and the experimental model revealed that the aurora sign derived from the irregularity of air spaces immediately below the pleura associated with interstitial pulmonary disorders. (2). One or more bands of RA were observed in 907 of the 2000 patients (45.4%). Of 177 patients with fatty liver, RA was observed in 14 (7.9%), while of the 1823 patients with no fatty liver, RA was observed in 893 (49.0%). The frequency of RA was significantly different (p<0.001) between the patients with and without fatty liver. In conclusion, parenchymal lung disease should be suspected when the aurora sign is noted on the dorsal side of the right hepatic lobe. However, RAs are rare in patients with fatty liver.