Enlarged cavum septum pellucidum and small thymus as markers for 22q11.2 deletion syndrome.

BACKGROUND: Enlarged cavum septum pellucidum (CSP) and hypoplastic thymus are proposed extra-cardiac fetal markers for 22q11.2 deletion syndrome. We sought to determine if they were part of the fetal phenotype of our cohort of fetuses with 22q11.2 deletion syndrome. METHODS: Case-control study of fetuses evaluated from 2016 to 2022. The study group included fetuses with laboratory confirmation of 22q11.2 deletion syndrome. The control group included pregnancies with conotruncal cardiac anomalies with normal microarray as well as structurally normal fetuses with normal microarray. The CSP and thymus were routinely measured during anatomical ultrasound in all patients at their initial visit at 27.1 ± 4.7 weeks. The CSP and thymus measurements were classified as abnormal if they were >95% or <5% for gestational age, respectively. The groups were compared using analysis of variance or Kruskal-Wallis for continuous variables and Fisher's exact test for categorical variables. Logistic regression was performed, and a Receiver Operating Characteristic (ROC) curve was constructed. RESULTS: We identified 47 fetuses with 22q11.2 deletion syndrome and compared them to 47 fetuses with conotruncal anomalies and normal microarray and 47 structurally normal fetuses with normal microarray. 51% (24/47) of fetuses with 22q11.2 deletion syndrome had an enlarged CSP compared to 6% (3/47) of fetuses with a conotruncal anomaly and normal microarray and none of the structurally normal fetuses (p < 0.001). Of the fetuses with 22q11.2 deletion syndrome, 83% (39/47) had a hypoplastic or absent thymus compared to 9% (4/47) of the fetuses with a conotruncal anomaly and normal microarray and none of the structurally normal fetuses (p < 0.001). 87% (41/47) of the fetuses with 22q11.2 deletion syndrome had conotruncal cardiac anomalies. Logistic regression revealed that both enlarged CSP and hypoplastic/absent thymus were associated with 22q11.2 deletion syndrome. The area under the ROC curve for the two markers was 0.94. CONCLUSION: An enlarged CSP and hypoplastic/absent thymus appear to be part of the fetal phenotype of 22q11.2 deletion syndrome. These markers are associated with conotruncal anomalies in the setting of 22q11.2 deletion syndrome but not in normal controls or fetuses with conotruncal defects and normal microarrays.

Fetal thoracic teratomas: mediastinal or pericardial?

BACKGROUND: Mediastinal and pericardial teratomas have overlapping imaging features that may make accurate prenatal diagnosis challenging. OBJECTIVE: To identify prenatal imaging features that may aid in distinguishing between mediastinal and pericardial teratomas. MATERIALS AND METHODS: Prenatally diagnosed pericardial and mediastinal teratomas evaluated at our fetal center from 1995 to 2020 were included in this Institutional Review Board-approved study. Lesion volume was calculated using prospectively reported ultrasound (US) measurements and the formula of a prolate ellipsoid, which was then normalized to head circumference. Prenatal US and magnetic resonance imaging (MRI) studies were anonymized with two fetal imagers reviewing the US studies and two different fetal imagers reviewing the MRI studies. These experienced reviewers scored location of the mass in the craniocaudal axis and in the transverse axis. MRI reviewers also scored the presence of inferior cardiac compression by the lesion and whether there was identifiable thymic tissue. Reviewer disagreements were resolved by consensus review. RESULTS: Eleven pericardial teratomas and 10 mediastinal teratomas were identified. All cases underwent detailed fetal anatomic US and fetal echocardiogram and 10/11 (91%) pericardial teratomas and 8/10 (80%) mediastinal teratomas underwent fetal MRI. Median volume was higher for mediastinal teratomas compared to pericardial teratomas (42.5 mL [interquartile range (IQR) 15.9 - 67.2 mL] vs. 8.1 mL [IQR 7.7 - 27.7 mL], P=0.01) and median volume/head circumference was also statistically higher in mediastinal teratomas (1.33 [IQR 0.78 - 2.61] vs. 0.43 [IQR 0.38 - 1.10], P=0.01). Logistic regression analysis demonstrated a statistical difference between teratoma types with respect to location in the craniocaudal axis by both modalities with mediastinal teratomas more commonly located in the upper and upper-middle thorax compared to pericardial teratomas, which were more commonly found in the middle thorax (US, P=0.03; MRI, P=0.04). Logistic regression analysis also demonstrated a statistical difference between teratoma types with respect to position along the transverse axis by both modalities with mediastinal teratomas more commonly located midline or left paramedian and pericardial teratomas more often right paramedian in location (US, P<0.01; MRI, P=0.02). Inferior cardiac compression observed by MRI was associated more commonly with mediastinal teratomas compared to pericardial teratomas (87.5% [7/8] vs. 10% [1/10], P<0.01). Identifiable thymus by MRI was more commonly observed in cases of pericardial teratomas, however, this difference was not statistically significant (P=0.32). CONCLUSION: Mediastinal teratomas are associated with larger lesion size and inferior cardiac compression when compared to pericardial teratomas. These features combined with lesion location in the craniocaudal and transverse axes may allow for more accurate prenatal diagnosis and optimal perinatal and surgical management.

Two's Company: Multiple Thoracic Lesions on Prenatal US and MRI.

BACKGROUND: Congenital pulmonary airway malformations (CPAM), bronchopulmonary sequestrations (BPS), and CPAM-BPS hybrid lesions are most commonly solitary; however, >1 lung congenital lung lesion may occur. OBJECTIVES: To assess the frequency of multiple congenital thoracic anomalies at a high-volume referral center; determine prenatal ultrasound (US) and magnetic resonance imaging (MRI) features of these multifocal congenital lung lesions that may allow prenatal detection; and determine the most common distribution or site of origin. METHODS: Database searches were performed from August 2008 to May 2019 for prenatally evaluated cases that had a final postnatal surgical diagnosis of >1 congenital lung lesion or a lung lesion associated with foregut duplication cyst (FDC). Lesion location, size, echotexture, and signal characteristics were assessed on prenatal imaging and correlated with postnatal computed tomographic angiography and surgical pathology. -Results: Of 539 neonates that underwent surgery for a thoracic lesion, 35 (6.5%) had >1 thoracic abnormality. Multiple discrete lung lesions were present in 19 cases, and a lung lesion associated with an FDC was present in 16. Multifocal lung lesions were bilateral in 3 cases; unilateral, multilobar in 12; and, unilobar multisegmental in 4. Median total CPAM volume/head circumference ratio for multifocal lung lesions on US was 0.66 (range, 0.16-1.80). Prenatal recognition of multifocal lung lesions occurred in 7/19 cases (36.8%). Lesion combinations were CPAM-CPAM in 10 cases, CPAM-BPS in 5, CPAM-hybrid in 2, hybrid-hybrid in 1, and hybrid-BPS in 1. Of 5 unilateral, multifocal lung lesions, multifocality was prenatally established through identification of a band of normal intervening lung or intrinsic differences in lesion imaging features. CONCLUSIONS: Although less common, multiple thoracic abnormalities can be detected prenatally. Of multifocal lung lesions, the most common combination was CPAM-CPAM, with a unilateral, multilobar distribution. Prenatal recognition is important for pregnancy counseling and postnatal surgical management.

Congenital diaphragmatic hernia sacs: prenatal imaging and associated postnatal outcomes.

BACKGROUND: The presence of a hernia sac in congenital diaphragmatic hernia (CDH) has been reported to be associated with higher lung volumes and better postnatal outcomes. OBJECTIVE: To compare prenatal imaging (ultrasound and MRI) prognostic measurements and postnatal outcomes of CDH with and without hernia sac. MATERIALS AND METHODS: We performed database searches from January 2008 to March 2017 for surgically proven cases of CDH with and without hernia sac. All children had a detailed ultrasound (US) examination and most had an MRI examination. We reviewed the medical records of children enrolled in our Pulmonary Hypoplasia Program. RESULTS: Of 200 cases of unilateral CDH, 46 (23%) had hernia sacs. Cases of CDH with hernia sac had a higher mean lung-to-head ratio (LHR; 1.61 vs. 1.17; P<0.01), a higher mean observed/expected LHR (0.49 vs. 0.37; P<0.01), and on MRI a higher mean observed/expected total lung volume (0.53 vs. 0.41; P<0.01). Based on a smooth interface between lung and herniated contents, hernia sac or eventration was prospectively questioned by US and MRI in 45.7% and 38.6% of cases, respectively. Postnatally, hernia sac is associated with shorter median periods of admission to the neonatal intensive care unit (45.0 days vs. 61.5 days, P=0.03); mechanical ventilation (15.5 days vs. 23.5 days, P=0.04); extracorporeal membrane oxygenation (251 h vs. 434 h, P=0.04); decreased rates of patch repair (39.0% vs. 69.2%, P<0.01); and pulmonary hypertension (56.1% vs. 75.4%, P=0.03). CONCLUSION: Hernia sac is associated with statistically higher prenatal prognostic measurements and improved postnatal outcomes. Recognition of a sharp interface between lung and herniated contents may allow for improved prenatal diagnosis; however, delivery and management should still occur at experienced quaternary neonatal centers.

Secondary Imaging Findings Aid in Prenatal Diagnosis and Characterization of Congenital Diaphragmatic Hernia: Role of an Abnormal Orientation of Vascular Structures and Gallbladder Position.

OBJECTIVES: To determine whether an abnormal orientation of the abdominal or hepatic vasculature and an abnormal gallbladder position on prenatal ultrasound (US) imaging are associated with intrathoracic liver herniation and postnatal outcomes in cases of congenital diaphragmatic hernia (CDH). METHODS: Children who underwent prenatal US examinations and postnatal CDH repair at our institution were eligible. Prenatal US images were reviewed, and the orientation of the superior mesenteric artery (SMA) and hepatic veins as well as gallbladder position were recorded. Findings were correlated with prenatal US measurements (lung-to-head ratio and calculated observed-to-expected lung-to-head ratio) and postnatal outcomes, including intrathoracic liver herniation, an extracorporeal membrane oxygenation (ECMO) requirement, and mortality. RESULTS: A total of 175 patients met inclusion criteria. The SMA was shown in 168 cases and had a cephalad orientation in 95.4% (161 of 168), which was not associated with outcome measures and represented bowel herniation. A cephalad orientation of the hepatic veins was identified in 52.6% (90 of 171) and was associated with intrathoracic liver herniation, an ECMO requirement, and mortality (P < .01). In right-sided CDH, the gallbladder was intrathoracic in 91.3% (21 of 23). In left-sided CDH, an abnormal gallbladder position was seen in 51.3% (76/152) and was associated with intrathoracic liver herniation, an ECMO requirement, mortality, and lower lung-to-head ratio and observed-to-expected lung-to-head ratio values. When combined, abnormal hepatic vein and gallbladder positions showed good sensitivity and specificity in predicting intrathoracic liver herniation (area under the curve, 0.93). CONCLUSIONS: Abnormal SMA, hepatic vein, and gallbladder positions can be used to improve prenatal characterization of CDH. Accurate depiction of these structures on prenatal US images may aid in patient counseling and postnatal management.

Congenital Lobar Overinflation: A Rare Enigmatic Lung Lesion on Prenatal Ultrasound and Magnetic Resonance Imaging.

OBJECTIVES: To report the ultrasound (US) features in prenatal cases of suspected congenital pulmonary airway malformation or unspecified lung lesions with a final surgical pathologic diagnosis of congenital lobar overinflation (CLO). METHODS: Institutional Review Board-approved radiology and clinical database searches from 2001 to 2017 were performed for prenatally diagnosed lung lesions with a final diagnosis of CLO. All patients had detailed US examinations in addition to magnetic resonance imaging (MRI). Size, echotexture, and vascularity were assessed with US, and the signal and vascularity were assessed with MRI. Follow-up prenatal US scans, postnatal imaging, and postnatal outcomes were reviewed. RESULTS: The study population consisted of 12 patients. The median gestational age was 23.3 weeks. The median congenital pulmonary airway malformation volume-to-head circumference ratio was 0.66. Lesion locations were 6 in the lower lobes (4 right and 2 left), 5 in the upper lobes (3 left and 2 right), and 1 in the right middle lobe. The texture was homogeneously echogenic relative to the normal lung in 100% with no visualized macrocysts. Hypervascularity by color Doppler US was observed in 5 cases (41.7%). A T2 hyperintense lung lesion was identified by MRI in 12 of 12 cases (100%), with elongated vessels identified in 11 of 12 cases (91.7%). All 12 cases had pathologically proven CLO. CONCLUSIONS: Congenital lobar overinflation should be considered in cases of prenatal echogenic lung lesions without macrocysts or classic findings of bronchial atresia. Hypervascularity may be an important imaging feature of a subset of CLO. Most cases become less conspicuous, decrease in size without overt hydrops, and are asymptomatic postnatally.

Going With the Flow: An Aid in Detecting and Differentiating Bronchopulmonary Sequestrations and Hybrid Lesions.

OBJECTIVES: To assess the ability of prenatal ultrasound (US) in identifying systemic feeding arteries in bronchopulmonary sequestrations and hybrid lesions and report the ability of US in classifying bronchopulmonary sequestrations as intralobar or extralobar. METHODS: Institutional Review Board-approved radiology and clinical database searches from 2008 to 2015 were performed for prenatal lung lesions with final diagnoses of bronchopulmonary sequestrations or hybrid lesions. All patients had detailed US examinations, and most patients had ultrafast magnetic resonance imaging (MRI). Lesion location, size, and identification of systemic feeding arteries and draining veins were assessed with US. RESULTS: The study consisted of 102 bronchopulmonary sequestrations and 86 hybrid lesions. The median maternal age was 30 years. The median gestational age was 22 weeks 5 days. Of bronchopulmonary sequestrations, 66 had surgical pathologic confirmation, and 100 had postnatal imaging. Bronchopulmonary sequestration locations were intrathoracic (n = 77), intra-abdominal (n = 19), and transdiaphragmatic (n = 6). Of hybrid lesions, 84 had surgical pathologic confirmation, and 83 had postnatal imaging. Hybrid lesion locations were intrathoracic (n = 84) and transdiaphragmatic (n = 2). Ultrasound correctly identified systemic feeding arteries in 86 of 102 bronchopulmonary sequestrations and 79 of 86 hybrid lesions. Of patients who underwent MRI, systemic feeding arteries were reported in 62 of 92 bronchopulmonary sequestrations and 56 of 81 hybrid lesions. Ultrasound identified more systemic feeding arteries than MRI in both bronchopulmonary sequestrations and hybrid lesions (P < .01). Magnetic resonance imaging identified systemic feeding arteries that US did not in only 2 cases. In cases in which both systemic feeding arteries and draining veins were identified, US could correctly predict intrathoracic lesions as intralobar or extralobar in 44 of 49 bronchopulmonary sequestrations and 68 of 73 hybrid lesions. CONCLUSIONS: Ultrasound is most accurate for systemic feeding artery detection in bronchopulmonary sequestrations and hybrid lesions and can also type the lesions as intralobar or extralobar when draining veins are evaluated.

Fetal Lymphatic Malformations: More Variable Than We Think?

Lymphatic malformations are benign lesions that result from abnormal development of the lymphatic and venous systems. These lesions may be detected during routine prenatal ultrasound screening, and typically demonstrate imaging findings of a multiseptate cystic lesion lacking solid components, vascularity, and calcifications. We report 73 cases of prenatally detected lymphatic malformations and describe greater variability in their prenatal sonographic appearance than previously reported, including purely cystic lesions and mixed cystic and solid lesions with calcifications. Appreciation of this increased variability is important in providing accurate prenatal diagnosis, counseling, and management.