Comparison of congenital pulmonary airway malformation volume ratios calculated by ultrasound and magnetic resonance imaging

The New Frontiers of Fetal Imaging: MRI Insights into Cardiovascular and Thoracic Structures

Fetal magnetic resonance imaging (fMRI) represents a second-line imaging modality that provides multiparametric and multiplanar views that are crucial for confirming diagnoses, detecting associated pathologies, and resolving inconclusive ultrasound findings. The introduction of high-field magnets and new imaging sequences has expanded MRI's role in pregnancy management. Recent innovations in ECG-gating techniques have revolutionized the prenatal evaluation of congenital heart disease by synchronizing imaging with the fetal heartbeat, thus addressing traditional challenges in cardiac imaging. Fetal cardiac MRI (fCMR) is particularly valuable for assessing congenital heart diseases, especially when ultrasound is limited by poor imaging conditions. fCMR allows for detailed anatomical and functional evaluation of the heart and great vessels and is also useful for diagnosing additional anomalies and analyzing blood flow patterns, which can aid in understanding abnormal fetal brain growth and placental perfusion. This review emphasizes fMRI's potential in evaluating cardiac and thoracic structures, including various gating techniques like metric optimized gating, self-gating, and Doppler ultrasound gating. The review also covers the use of static and cine images for structural and functional assessments and discusses advanced techniques like 4D-flow MRI and T1 or T2 mapping for comprehensive flow quantification and tissue characterization.

Serial lung mass volume ratios as prognostic indicators of neonatal respiratory morbidity in fetal pulmonary malformations

BACKGROUND

Several studies have shown that the congenital pulmonary airway malformation volume ratio is a useful prognosticator of neonatal outcome in prenatally diagnosed lung lesions. However, there remains a lack of consensus on which congenital pulmonary airway malformation volume ratio values have the best predictive value because of operator dependence, inherent changes in lung lesion size throughout gestation, and the widespread use of maternal steroids.

OBJECTIVE

This study sought to determine the association between serial congenital pulmonary airway malformation volume ratio measurements and neonatal outcomes among fetuses with lung malformations.

STUDY DESIGN

This was a retrospective cohort study of fetuses with a prenatally diagnosed lung malformation managed at 2 major fetal centers from January 2010 to December 2021. Prenatal variables, including prospectively measured congenital pulmonary airway malformation volume ratio measurements (initial, maximum, and final), were analyzed. The results were correlated with 3 outcome measures, namely surgical resection before 30 days of life, a need for supplemental O2 at birth, and endotracheal intubation at birth. Statistical analyses were performed using receiver operating characteristic curve analyses, Welch 2 sample t tests, and multivariable logistic regressions (P<.05).

RESULTS

There were 123 fetuses with isolated lung lesions identified. Eight (6.5%) had hydrops. The mean initial congenital pulmonary airway malformation volume ratio was 0.67±0.61 cm2 at 22.9±3.9 weeks' gestation. The mean maximum congenital pulmonary airway malformation volume ratio was 1.08 ± 0.94 cm2 at 27.0 ± 4.0 weeks' gestation. The mean final congenital pulmonary airway malformation volume ratio was 0.58±0.60 cm2 at 33.2±4.1 weeks' gestation. At a mean gestational age at delivery of 38.3±2.6 weeks, 15 (12.2%) underwent neonatal lung resection for symptomatic disease. In a multivariable regression, all 3 congenital pulmonary airway malformation volume ratio measurements showed a significant correlation with neonatal lung resection (P<.001). Optimal congenital pulmonary airway malformation volume ratio cutoffs were established based on an initial congenital pulmonary airway malformation volume ratio of ≥0.8 cm2, maximum congenital pulmonary airway malformation volume ratio of ≥1.5 cm2, and a final congenital pulmonary airway malformation volume ratio of ≥1.3 cm2 with associated areas under the curve of 0.89, 0.97, and 0.93, respectively. The final congenital pulmonary airway malformation volume ratio had the highest specificity for predicting surgical lung resection in the early postnatal period.

CONCLUSION

Measuring congenital pulmonary airway malformation volume ratios throughout pregnancy in fetuses with pulmonary malformations has clinical value for prenatal counseling and planning care transition after delivery. Fetuses with a final congenital pulmonary airway malformation volume ratio of more than 1.3 cm2 are likely to require neonatal surgery and therefore should be delivered at tertiary care centers with a neonatal intensive care unit and pediatric surgical expertise.

Acutely presenting congenital chest lesions: a primer for the radiologist

Congenital chest lesions encompass several important entities. Without prompt intervention, many of these can culminate in serious complications. Timely and accurate radiologic interpretation of these entities is integral to patient management. Imaging can help characterize and prognosticate several of these entities, and may both suggest the need for and guide therapy. We overview the clinical presentation, associated complications, imaging characteristics, and prognostic indicators-both postnatal and antenatal-of the spectrum of emergently presenting congenital chest lesions. We also outline current and evolving management strategies, whether fetal, peripartum, or postnatal. The ultimate goal is to help radiologists formulate timely and effective diagnoses of these entities and boost the relevance of their input towards clinical decision-making.

The prenatal ultrasonic character and postnatal follow-up of 227 microcystic and macrocystic congenital cystic adenomatoid malformations

The objective of our study was to compare microcystic and macrocystic congenital cystic adenomatoid malformation (CCAMs) through prenatal characteristics, perinatal outcome, postnatal management and development after consultation in our prenatal diagnosis centre. We conducted a retrospective cohort study of 227 cases prenatally diagnosed as CCAM in our hospital within three years. One hundred and eighty-one cases continued their pregnancy and 46 pregnancies were terminated. One hundred and fifteen of 227 cases were microcystic and 112 were macrocystic. The prenatal ultrasound characteristics of two types showed no statistically significant differences, despite that CVR of macrocystic CCAMs was mildly greater than microcystic. None of recorded cases received surgical intervention in utero. Compared with healthy foetuses, CCAMs presented with higher percentage of polyhydramnios and male foetuses, larger amount of postpartum blood loss and longer duration of NICU hospitalisation. Compared with 46 legal abortions, continued pregnancy cases had a smaller CVR, less polyhydramnios, cardiac shift and hydrops. One hundred and seventy-nine cases were followed up after birth and 174 babies were asymptomatic. Thirty one cases received successful surgical resection. In conclusion, the prenatally diagnosed CCAMs have a good short-term prognosis and conservative management is a reasonable option in asymptomatic fetuses. Microcystic and macrocystic CCAMs both presented similar prenatal courses and perinatal prognoses. Conservative management, prenatally and postnatally, could be accepted in selected cases.Impact statementWhat is already known on this subject? Congenital cystic adenomatoid malformation is a well-known developmental abnormality of the lung. The prognosis for most CCAMs is good, but the prenatal and postnatal management remains controversial.What do the results of this study add? This study is one of the largest case cohorts to conclude that microcystic and macrocystic CCAMs both presented similar prenatal courses and perinatal prognoses. Conservative management is a reasonable option in asymptomatic babies.What are the implications of these findings for clinical practice and/or further research? A comprehensive assessment by an experienced multidisciplinary team is necessary to forbid blinding abortions of CCAMs. Conservative management prenatally and postnatally could be accepted in most asymptomatic cases.

Accuracy of prenatal and postnatal imaging for management of congenital lung malformations

PURPOSE

The purpose of this study was to compare the accuracy of prenatal and postnatal imaging modalities for evaluation and management of congenital lung malformations (CLMs).

METHODS

A retrospective review was performed of all fetuses evaluated for a CLM between December 2001 and January 2018. Pre and postnatal imaging findings, operative treatment, and patient outcomes were collected. Patients were included in analysis if they had fetal imaging (US and/or fetal MRI), a postnatal chest CT, and surgical pathology.

RESULTS

Over the study period, we identified 157 patients with prenatal imaging that also had a follow-up with postnatal chest CT at a median age of 2.1 [1.4, 3.2] months. Of these, 75% (n = 117) had surgical resection. Diagnostic accuracy (DA) for localization of unilobar lesions was 100% for pre- and postnatal imaging and 97% vs 98% for multilobar disease, respectively. On comparison for identification of aberrant vasculature and pathology prediction, pre- and postnatal imaging DAs were similar. However, postnatal CT had the highest specificity for diagnosing lesions overall (p < 0.05).

CONCLUSION

Prenatal imaging provides valuable information for counseling and possible fetal intervention. However, this study suggests that postnatal CT scan continues to provide important information for preoperative counseling and surgical management.

TYPE OF STUDY

Retrospective study.

LEVEL OF EVIDENCE

Level IV.

The Utility of the Congenital Pulmonary Airway Malformation-Volume Ratio in the Assessment of Fetal Echogenic Lung Lesions: A Systematic Review

Although relatively uncommon, the incidence of fetal echogenic lung lesions - a heterogeneous group of anomalies that includes congenital pulmonary airway malformations (CPAM) and bronchopulmonary sequestrations (BPS) - has increased recently. Two decades ago, the CPAM-volume ratio (CVR) was first described as a tool to predict the development of hydrops, with this outcome found to be unlikely in fetuses with CVRs of ≤1.6 cm2. Since then, no clear international consensus has evolved as to the optimal CVR thresholds for the prediction of fetal/neonatal outcomes. This systematic review aimed to assess all original research studies that reported on the predictive utility of the CVR. Potentially relevant papers were identified through searching for citations of the paper that originally described the CVR, in addition to keyword searches of electronic databases. Fifty-two original research papers were included in the final review. Of these, 34 used the CVR for descriptive purposes only, 5 assessed the validity of established thresholds in different populations, and 13 proposed new thresholds. The evidence identified in this review would suggest that a threshold much lower than 1.6 cm2 is likely to be of greater utility in most populations for many outcomes of perinatal relevance. For neonatal outcomes (mostly respiratory compromise at birth), a CVR on the initial ultrasound scan ranging from 0.5 to 1.0 cm2 appears to have the greatest predictive value. Although a number of studies concurred that 1.6 cm2 was a useful threshold for the prediction of hydrops, many others were unable to assess this due to the rarity of this complication. For this reason, thresholds as low as 0.4 cm2 may be more useful for the prediction of a broader range of fetal concerns, including mediastinal shift and fluid collections. Further large-scale studies are required to determine the true utility of this well-established index.

Congenital lung lesions

Diagnosis and management of congenital lung malformations has evolved dramatically over the past several decades. Advancement in imaging technology has enabled earlier, more definitive diagnoses and, consequently, more timely intervention in utero or after birth, when indicated. These advancements have increased overall survival rates to around 95% from historical rates of 60%. However, further refinement of diagnostic technique and standardization of treatment is needed, particularly as the increased sensitivity of diagnostic imaging results in more frequent diagnoses. In this article, we provide an updated review of the diagnostic strategies, management, and prognosis of congenital lung malformations.

Congenital pulmonary airway malformations: state-of-the-art review for pediatrician's use

Congenital pulmonary airway malformations or CPAM are rare developmental lung malformations, leading to cystic and/or adenomatous pulmonary areas. Nowadays, CPAM are diagnosed prenatally, improving the prenatal and immediate postnatal care and ultimately the knowledge on CPAM pathophysiology. CPAM natural evolution can lead to infections or malignancies, whose exact prevalence is still difficult to assess. The aim of this "state-of-the-art" review is to cover the recently published literature on CPAM management whether the pulmonary lesion was detected during pregnancy or after birth, the current indications of surgery or surveillance and finally its potential evolution to pleuro-pulmonary blastoma.

CONCLUSION

Surgery remains the cornerstone treatment of symptomatic lesions but the postnatal management of asymptomatic CPAM remains controversial. There are pros and cons of surgical resection, as increasing rate of infections over time renders the surgery more difficult after months or years of evolution, as well as risk of malignancy, though exact incidence is still unknown. What is known: • Congenital pulmonary airway malformations (CPAM) are rare developmental lung malformations mainly antenatally diagnosed. • While the neonatal management of symptomatic CPAM is clear and includes prompt surgery, controversies remain for asymptomatic CPAM due to risk of infections and malignancies. What is new: • Increased rate of infection over time renders the surgery more difficult after months or years of evolution and pushes for recommendation of early elective surgery. • New molecular or pathological pathways may help in the distinction of type 4 CPAM from type I pleuropulmonary blastoma.

Highlights on MRI of the fetal body

Fetal MRI is a level III diagnostic tool performed subsequently a level II prenatal ultrasound (US), in cases of inconclusive ultrasonographic diagnosis or when a further investigation is required to confirm or improve the diagnosis, to plan an appropriate pregnancy management. Fetal MRI plays an increasingly important role in the prenatal diagnosis of fetal neck, chest and abdominal malformations, even if its role has been amply demonstrated, especially, in the field of fetal CNS anomalies. Due to its multiparametricity and multiplanarity, MRI provides a detailed evaluation of the whole fetal respiratory, gastrointestinal and genitourinary systems, especially on T2-weighted (W) images, with a good tissue contrast resolution. In the evaluation of the digestive tract, T1-W sequences are very important in relation to the typical hyperintensity of the large intestine, due to the presence of meconium. The objective of this review is to focus on the application of fetal MRI in neck, chest and abdominal diseases.

Prediction of neonatal respiratory distress in pregnancies complicated by fetal lung masses

OBJECTIVE

The objective of this article is to evaluate the utility of fetal lung mass imaging for predicting neonatal respiratory distress.

METHOD

Pregnancies with fetal lung masses between 2009 and 2014 at a single center were analyzed. Neonatal respiratory distress was defined as intubation and mechanical ventilation at birth, surgery before discharge, or extracorporeal membrane oxygenation (ECMO). The predictive utility of the initial as well as maximal lung mass volume and congenital pulmonary airway malformation volume ratio by ultrasound (US) and magnetic resonance imaging (MRI) was analyzed.

RESULTS

Forty-seven fetal lung mass cases were included; of those, eight (17%) had respiratory distress. The initial US was performed at similar gestational ages in pregnancies with and without respiratory distress (26.4 ± 5.6 vs 22.3 ± 3 weeks, p = 0.09); however, those with respiratory distress had higher congenital volume ratio at that time (1.0 vs 0.3, p = 0.01). The strongest predictors of respiratory distress were maximal volume >24.0 cm³ by MRI (100% sensitivity, 91% specificity, 60% positive predictive value, and 100% negative predictive value) and maximal volume >34.0 cm³ by US (100% sensitivity, 85% specificity, 54% positive predictive value, and 100% negative predictive value).

CONCLUSION

Ultrasound and MRI parameters can predict neonatal respiratory distress, even when obtained before 24 weeks. Third trimester parameters demonstrated the best positive predictive value. © 2017 John Wiley & Sons, Ltd.