Fetal MR in the evaluation of pulmonary and digestive system pathology

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.

Guidelines of the Italian Society of Videosurgery in Infancy (SIVI) for the minimally invasive treatment of fetal and neonatal ovarian cysts

In the last three decades, fetal ovarian cysts were diagnosed more frequently, due to technological improvement and the increasing use of prenatal screening ultrasound. Nonetheless, treatment uncertainties are still present, either prenatally or postnatally. Recently, significant innovations on diagnosis and treatment have been proposed and a more conservative, minimally invasive approach may be offered to the Pediatrician or the Surgeon who face with this condition during prenatal or neonatal age. (...).

Fetal MRI in management of complicated meconium ileus: Prenatal and surgical imaging

OBJECTIVE

To review fetal MRI cases surgically proven to have meconium ileus (MI) and obstruction, describe the common fetal MRI findings that distinguish cases of complicated MI, and to compare these findings with surgical images and perinatal outcomes.

METHOD

We performed a retrospective review of all fetal MRI examinations and the corresponding medical record from our tertiary care children's hospital over an 18-month period. Postnatal management and outcomes were reviewed for these patients, and those patients with surgical or postmortem diagnosis of complicated MI were included in the study.

RESULTS

Our analysis revealed 7 cases. In this cohort, 3 imaging features of the fetal bowel were repeatedly seen: gradient appearance of intraluminal bowel contents, abnormally localized meconium signal, and collapsed appearance of the colon on MRI. Surgical diagnoses confirmed MI. All live-born infants underwent surgical repair.

CONCLUSION

Fetal MRI should be included in the diagnostic algorithm of any pregnancy where fetal bowel obstruction is suspected to better risk stratify patients.

Magnetic Resonance Imaging Diagnosis of Volvulus through Mesenteric Defect in Neonate

Antenatal midgut volvulus is a rare surgical emergency in which bowel is severely compromised. Rarely the etiology is a mesenteric defect. Early diagnosis is essential and lifesaving in the immediate newborn period. Typically upper gastrointestinal or ultrasound imaging can be suggestive of the diagnosis of volvulus in the neonate. Sometimes, however, the diagnosis may be elusive. Herein, we report on the use of neonatal magnetic resonance imaging to diagnose a midgut volvulus that occurred through a congenital mesenteric defect.

Prenatal Imaging of the Gastrointestinal Tract with Postnatal Imaging Correlation

Prenatal detection of a wide variety of anomalies and masses of the gastrointestinal tract is now possible. Prenatal imaging with ultrasonography and in selected cases magnetic resonance imaging provides invaluable information to the referring obstetrician, the maternal fetal medicine specialist, the neonatologist and pediatrician who will care for the child after birth, the surgeons and pediatric specialists who will repair or manage a prenatally detected anomaly, and of course to the parents, allowing them to prepare psychologically and financially for the specific interventions that may be needed for their child. Additional screening for associated anomalies can take place, route of delivery can be decided, and arrangements for delivery in an appropriate setting can be made. Prenatal detection also allows for consideration for pregnancy termination. This article will give a broad overview of anomalies of the gastrointestinal tract that can be detected prenatally and their imaging appearance postnatally.

Fetal Magnetic Resonance Imaging of Malformations Associated with Heterotaxy

Magnetic resonance imaging (MRI) is increasingly used as an investigation during fetal life, particularly for assessment of intracranial masses, congenital diaphragmatic hernia, myelomeningocele, and abdominal masses. As the number of scans increases, so is the variety of congenital malformations being recognized. It is axiomatic that interpretation of the findings is enhanced when attention is paid to the likely findings in the setting of known syndromes, this information then dictating the need for additional acquisition of images. One such syndrome is so-called "visceral heterotaxy", in which there is typically an isomeric, rather than a lateralized, arrangement of the thoracic and abdominal organs. Typically associated with complex congenital cardiac malformations, heterotaxy can also involve the central nervous system, and produce pulmonary, gastrointestinal, immunologic, and genitourinary malformations. In this review, we discuss how these findings can be demonstrated using fetal MRI.

[Fetal magnetic resonance imaging of thoracic and abdominal malformations]

CLINICAL/METHODICAL ISSUE

Diagnosis and differential diagnosis of fetal thoracic and abdominal malformations.

STANDARD RADIOLOGICAL METHODS

Ultrasound and magnetic resonance imaging (MRI).

METHODICAL INNOVATIONS

In cases of suspected pathologies based on fetal ultrasound MRI can be used for more detailed examinations and can be of assistance in the differential diagnostic process.

PERFORMANCE

Improved imaging of anatomical structures and of the composition of different tissues by the use of different MRI sequences.

ACHIEVEMENTS

Fetal MRI has become a part of clinical routine in thoracic and abdominal malformations and is the basis for scientific research in this field.

PRACTICAL RECOMMENDATIONS

In cases of thoracic or abdominal malformations fetal MRI provides important information additional to ultrasound to improve diagnostic accuracy, prognostic evaluation and surgical planning.