Congenital chest malformations: a multimodality approach with emphasis on fetal MR imaging

An Incidental Finding of Congenital Pulmonary Airway Malformation Type 3 During a Forensic Autopsy for a Sudden Infant Death: A Case Report With a Brief Literature Review

ABSTRACT

Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic airway malformation, is a developmental disorder of the lower respiratory tract. It is subdivided into 5 types based on clinical and pathologic features. Type 3, an adenomatoid type of CPAM, is the second rarest form of CPAM, occurring in approximately 5% of all CPAM cases. This article reports an autopsy of a nearly 11-week-old male infant, found unresponsive in bed with his mother. She had fallen asleep after breastfeeding a few hours prior. Although the autopsy and additional technical examinations did not uncover the exact cause of death, CPAM type 3 was eventually identified on histological examination. Taking into account the context of this case, in which accidental asphyxia/neglect could not be ruled out, it is thought that the presence of CPAM might have contributed to the demise of the infant. As CPAM is a rare congenital disorder, the diagnosis could easily be missed. Therefore, this article aims to raise awareness of this diagnosis and points out the clinical and pathologic features of this disorder.

Characterization of the Hyperintense Bronchus Sign as a Fetal MRI Marker of Airway Obstruction

Background Fetal MRI-based differential diagnosis of congenital lung malformations is difficult because of the paucity of well-described imaging markers. Purpose To characterize the hyperintense bronchus sign (HBS) in in vivo fetal MRI of congenital lung malformation cases. Materials and Methods In this retrospective two-center study, fetal MRI scans obtained in fetuses with congenital lung malformations at US (January 2002 to September 2018) were reviewed for the HBS, a tubular or branching hyperintense structure within a lung lesion on T2-weighted images. The frequency of the HBS and respective gestational ages in weeks and days were analyzed. Areas under the curve (AUCs), 95% CIs, and P values of the HBS regarding airway obstruction, as found in histopathologic and postnatal CT findings as the reference standards, were calculated for different gestational ages. Results A total of 177 fetuses with congenital lung malformations (95 male fetuses) and 248 fetal MRI scans obtained at a median gestational age of 25.6 weeks (interquartile range, 8.9 weeks) were included. The HBS was found in 79% (53 of 67) of fetuses with bronchial atresia, 71% (39 of 55) with bronchopulmonary sequestration (BPS), 43% (three of seven) with hybrid lesion, 15% (six of 40) with congenital cystic adenomatoid malformation, and 13% (one of eight) with bronchogenic cyst at a median gestational age of 24.9 weeks (interquartile range, 9.7 weeks). HBS on MRI scans at any gestational age had an AUC of 0.76 (95% CI: 0.70, 0.83; P = .04) for the presence of isolated or BPS-associated airway obstruction at histopathologic analysis and postnatal CT. The AUC of HBS on fetal MRI scans obtained until gestational age of 26 weeks (AUC, 0.83; 95% CI: 0.75, 0.91; P < .001) was significantly higher (P = .045) than that for fetal MRI scans obtained after gestational age 26 weeks (AUC, 0.69; 95% CI: 0.57, 0.80; P = .004). Conclusion The hyperintense bronchus sign is a frequently detectable feature at fetal MRI and is associated with airway obstruction particularly before gestational age 26 weeks. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Dubinsky in this issue.

Tomographic findings in bronchial atresia

Objective

To evaluate computed tomography (CT) findings in 23 patients with bronchial atresia.

Materials and Methods

The CT images were reviewed by two radiologists who reached decisions by consensus. We included only patients who presented with abnormalities on CT and in whom the diagnosis had been confirmed by pathological examination of the surgical specimen (if the lesion was resected). The CT scans were assessed in order to identify the main findings and to map the distribution of the lesions (i.e., to determine whether the pulmonary involvement was unilateral or bilateral).

Results

The main CT finding was the combination of bronchocele and hyperinflation of the distal lung. That combination was observed in all of the patients. The lesions were unilateral in all 23 cases, being seen predominantly in the left upper lobe, followed by the right lower lobe, right upper lobe, middle lobe, and left lower lobe.

Conclusion

The diagnosis of bronchial atresia can be reliably made on the basis of a finding of bronchocele accompanied by hyperinflation of the adjacent lung parenchyma.

Usefulness of prenatal magnetic resonance imaging in differential diagnosis of fetal congenital cystic adenomatoid malformation and bronchopulmonary sequestration

BACKGROUND

Congenital cystic adenomatoid malformation (CCAM) and bronchopulmonary sequestration (BPS) are the most common lung diseases in fetuses. There are differences in the prognosis and treatment of CCAM and BPS, and the clinical diagnosis and treatment plan is usually prepared prior to birth. Therefore, it is quite necessary to make a clear diagnosis before delivery. CCAM and BPS have similar imaging features, and the differentiation mainly relies on the difference in supply vessels. However, it is hard to distinguish them due to invisible supplying vessels on some images.

AIM

To explore the application value of magnetic resonance imaging (MRI) in the differential diagnosis of fetal CCAM and BPS.

METHODS

Data analysis for 32 fetuses with CCAM and 14 with BPS diagnosed by prenatal MRI at Huzhou Maternal and Child Health Care Hospital and Anhui Provincial Children’s Hospital from January 2017 to January 2020 was performed to observe the source blood vessels of lesions and their direction. Pathological confirmation was completed through CT examination and/or operations after birth.

RESULTS

After birth, 31 cases after birth were confirmed to be CCAM, and 15 were confirmed to be BPS. The CCAM group consisted of 21 macrocystic cases and 10 microcystic cases. In 18 cases, blood vessels were visible in lesions. Blood supply of the pulmonary artery could be traced in eight cases, and in 10 cases, only vessels running from the midline to the lateral down direction were observed. No lesions were found in four macrocystic cases and one microcystic case with CCAM through CT after birth; two were misdiagnosed by MRI, and three were misdiagnosed by prenatal ultrasonography. The BPS group consisted of 12 intralobar cases and three extralobar cases. Blood vessels were visible in lesions of nine cases, in four of which, the systemic circulation blood supply could be traced, and in five of which, only vessels running from the midline to the lateral up direction were observed. Three were misdiagnosed by MRI, and four were misdiagnosed by prenatal ultrasonography.

CONCLUSION

CCAM and BPS can be clearly diagnosed based on the origin of blood vessels, and correct diagnosis can be made according to the difference in the direction of the blood vessels, but it is hard distinguish microcystic CCAM and BPS without supplying vessels. In some CCAM cases, mainly the macrocystic ones, the lesions may disappear after birth.

Fetal ultrasound and magnetic resonance imaging: a primer on how to interpret prenatal lung lesions

Fetal lung lesions include common lesions such as congenital pulmonary airway malformation (CPAM), bronchopulmonary sequestration (BPS) and combined CPAM-BPS hybrid lesions, as well as less common entities including congenital lobar emphysema/obstruction, bronchial atresia, bronchogenic cysts and rare malignant pulmonary lesions such as pleuropulmonary blastoma. Fetal lung lesions occur in approximately 1 in 15,000 live births and are thought to arise from a spectrum of abnormalities related to airway obstruction and malformation, with the lesion type depending on the timing of insult, level of bronchial tree involvement, and severity of obstruction. Lesions vary from small and asymptomatic to large and symptomatic with significant mass effect on surrounding structures. Accurate diagnosis and characterization of these anomalies is crucial for guiding patient counseling as well as perinatal and postnatal management. The goal of this review is to provide an overview of normal fetal lung appearance and imaging features of common and uncommon lesions on both ultrasound and MR imaging, and to discuss key aspects in reporting and evaluating the severity of these lesions.

Thoracoscopic removal of a displaced thoracoamniotic shunt in a newborn with antenatal pleural effusion-a case report

Thoracoamniotic shunt has been considered as a treatment for antenatal pleural effusion and complication is rare. In majority of cases, the shunt can be removed uneventfully. In this article, we reported a rare complication of shunt migration resulting in the need of thoracoscopic removal at newborn period. The patient born at 39+3 weeks of gestation suffered from antenatal chylothorax detected at 28 weeks and was managed by intrauterine thoracoamniotic shunt insertion. This was complicated by shunt displacement, which caused respiratory distress after birth requiring ventilatory support and progressive pleural effusion in this patient. To prevent further neonatal compromise, thoracoscopic removal of the retained shunt was done on day 7 of life followed by post-op chest drain insertion. Post-op condition was stable with resolution of respiratory distress, and the patient was discharge on post-op day 16. We would like to remind clinicians about this potential complication of thoracoaminotic shunt, which can pose a potential risk of severe neonatal compromise, and that it can be managed by minimal invasive surgery even in the newborn period.

Prenatal diagnosis of congenital lobar fluid overload

Prenatal congenital lobar fluid overload (CLFO), which was first described by Ramsay and Byron, is identical to postnatal congenital lobar overinflation. It is characterized by progressive lobar overexpansion that compresses the other adjacent lung lobes. The underlying cause can be an intrinsic cartilaginous abnormality or an extrinsic airway compression. It may be associated with cardiovascular anomalies in 12%-14% of cases and affects males more frequently than females. Most cases are diagnosed postnatally, but early antenatal diagnosis and sequential follow-up are attempted for early treatment, if clinically indicated. This article provided a thorough review of CLFO, including prenatal diagnosis and differential diagnoses, as well as comprehensive illustrations of the perinatal imaging findings of CLFO. Prenatal diagnosis of fetal lung lesions should include CLFO in the differential diagnosis and prompt investigation for associated anomalies.

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.

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.

Applicability of three-dimensional imaging techniques in fetal medicine

Objective

To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology.

Materials and Methods

We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques.

Results

Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations.

Conclusion

The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models.

Imaging findings of bronchial atresia in fetuses, neonates and infants

Congenital lung malformations are increasingly detected before birth. However, bronchial atresia is rarely identified in utero and not always recognized in neonates. There are two types of atresia: 1) proximal, located at the level of the mainstem or the proximal lobar bronchi, which is extremely rare and usually lethal during pregnancy, causing a tremendous volume increase of the distal involved lung with secondary hypoplasia of the normal lung, and 2) peripheral, located at the segmental/subsegmental bronchial level, which may present as an isolated lesion or as part of a complex congenital malformation. Prenatal findings are mostly nonspecific. Postnatal exams show overinflated lung areas and focal bronchial dilations. The typical fluid-filled bronchoceles are not always observed in neonates but develop progressively in the first months of life. This pictorial essay describes the spectrum of imaging findings of bronchial atresia in fetuses, neonates and infants.

Developmental lung malformations in children: recent advances in imaging techniques, classification system, and imaging findings

Congenital lung anomalies represent a diverse group of developmental malformations of the lung parenchyma, arterial supply, and venous drainage, which may present anywhere from the prenatal period through adulthood. It is imperative for radiologists to be aware of imaging techniques and imaging appearance of these anomalies across the pediatric age range. This review presents the spectrum of these lesions that are often encountered in daily clinical practice. Each anomaly is discussed in terms of underlying etiology, clinical presentation, and imaging characterization with emphasis on the most up-to-date research and treatment. Knowledge of these areas is essential for accurate, timely diagnosis, which aids in optimizing patient outcomes.

Prenatal imaging and postnatal presentation, diagnosis and management of congenital lung malformations

PURPOSE OF REVIEW

Congenital lung malformations (CLMs) vary in their clinical presentation and severity. Increases in prenatal diagnosis, observed regression of certain lesions, and prognostic uncertainty are driving an evolution in management.

RECENT FINDINGS

There has been an increase in the early diagnosis of these malformations, a change that is attributable to the routine use of prenatal ultrasound. Although prenatal diagnosis of CLMs using ultrasound and MRI has increased, chest radiography and computed tomography still play important roles in diagnosis. The management of these lesions depends on the type of malformation and symptoms. The treatment of asymptomatic patients with lung malformations is controversial, because the prognosis of these lesions is largely unknown. Proponents of early intervention argue that the complications of CLM, which may include infection, pneumothorax, bleeding and malignant transformation, justify surgery. Advocates of conservative management note that some CLMs disappear postnatally, and that the long-term complication rate following surgery is unknown. There is a need to obtain natural history data regardless of the therapeutic recommendations.

SUMMARY

This article reviews the prenatal radiographic features and postnatal clinical findings of various CLMs and the dilemmas regarding treatment.

Congenital lung malformations: radiological findings and clues for differential diagnosis

Congenital lung malformations encompass a wide spectrum of conditions with a broadly varying clinical presentation. They are often a source of morbidity in infants and children. Their management depends on the type of malformation and its clinical presentation. Usually, the diagnosis requires an imaging evaluation. Classifications of bronchopulmonary malformations have undergone significant revision in recent years and several theories have attempted to explain their confusing pathogenesis. There are considerable degrees of overlapping and hybrid conditions are common, with interrelated malformations showing various radiologic and pathologic features. Attending to the pathophysiological mechanisms and structures involved, lung malformations can be divided into three categories: bronchopulmonary anomalies, combined lung and vascular abnormalities, and vascular anomalies. The purpose of this article is to review the current imaging techniques for evaluating lung malformations in pediatric patients and their characteristic imaging findings. Moreover, this review discusses a useful classification and offers some clues to facilitate the differential diagnosis.

Potential of magnetic resonance for imaging the fetal heart

Significant congenital heart disease (sCHD) affects 3.6 per 1000 births, and is often associated with extracardiac and chromosomal anomalies. Although early mortality has been substantially reduced and the rate of long-term survival has improved, sCHD is, after preterm birth, the second most frequent cause of neonatal infant death. The prenatal detection of cardiac and vascular abnormalities enables optimal parental counselling and perinatal management. Echocardiography (ECG) is the first-line examination and gold standard by which cardiac malformations are defined. However, adequate examination by an experienced healthcare provider with modern technical imaging equipment is required. In addition, maternal factors and the gestational age may lower the image quality. Fetal magnetic resonance imaging (MRI) has been implemented over the last several years and is already used in the clinical routine as a second-line approach to assess fetal abnormalities. MRI of the fetal heart is still not routinely performed. Nevertheless, fetal cardiac MRI has the potential to complement ultrasound in detecting cardiovascular malformations and extracardiac lesions. The present work reviews the potential of MRI to delineate the anatomy and pathologies of the fetal heart. This work also deals with the limitations and continuing developments designed to overcome the current problems in cardiac imaging, including fast fetal heart rates, the lack of ECG-gating, and the presence of fetal movements.

Congenital lung lesions: prenatal MRI and postnatal findings

BACKGROUND

Congenital lung lesions refer to a spectrum of malformations and developmental abnormalities of the foregut, pulmonary airways and vasculature. These lesions range from small, asymptomatic to large space-occupying masses that can increase risk of fetal death and respiratory compromise after birth. Prenatal sonography has been used for routine screening in pregnancy. The advent of prenatal magnetic resonance imaging leads to complementary use in the diagnosis of fetal anomalies, including in fetuses with congenital lung lesions.

OBJECTIVE

To determine whether fetal MRI can differentiate congenital lung lesions by comparing prenatal diagnosis with postnatal imaging and pathology.

MATERIALS AND METHODS

In a 4-year period, 76 fetuses with suspected lung lesions were referred for fetal MRI. We retrospectively reviewed the MR exams and assigned a specific diagnosis based on predetermined criteria. We then compared the prenatal diagnosis to postnatal imaging and pathology.

RESULTS

Of 76 cases, 7 were excluded because of an alternative diagnosis. Of the 69 remaining patients, 3 died and 13 were lost to follow-up. Among the 53 patients, there were 56 lung lesions. Four of these lesions were difficult to diagnose because of size and location. Based on imaging records we gave the remaining 52 lesions a specific prenatal diagnosis: 28 congenital pulmonary airway malformations (CPAM), 4 bronchopulmonary sequestrations (BPS), 9 cases of overinflation, 9 hybrid lesions and 2 bronchogenic cysts. The prenatal diagnosis was concordant with postnatal evaluation in 51 of the 52 lung lesions. One fetus given the diagnosis of CPAM prenatally was diagnosed with a hybrid lesion postnatally.

CONCLUSION

Prenatal MRI is highly accurate in defining congenital lung anomalies. When fetal MRI findings suggest a specific diagnosis, postnatal findings confirmed the prenatal MRI diagnosis in 98% of cases.

Fetal circulation in left-sided congenital heart disease measured by cardiovascular magnetic resonance: a case-control study

BACKGROUND

The distribution of blood flow in fetuses with congenital heart disease (CHD) is likely to influence fetal growth, organ development, and postnatal outcome, but has previously been difficult to study. We present the first measurements of the distribution of the fetal circulation in left-sided CHD made using phase contrast cardiac magnetic resonance (CMR).

METHODS

Twenty-two fetuses with suspected left-sided CHD and twelve normal controls underwent fetal CMR and echocardiography at a mean of 35 weeks gestation (range 30-39 weeks).

RESULTS

Fetuses with left-sided CHD had a mean combined ventricular output 19% lower than normal controls (p < 0.01). In fetuses with left-sided CHD with pulmonary venous obstruction, pulmonary blood flow was significantly lower than in those with left-sided CHD without pulmonary venous obstruction (p < 0.01). All three fetuses with pulmonary venous obstruction had pulmonary lymphangectasia by fetal CMR and postnatal histology. Fetuses with small but apex forming left ventricles with left ventricular outflow tract or aortic arch obstruction had reduced ascending aortic and foramen ovale flow compared with normals (p < 0.01). Fetuses with left-sided CHD had more variable superior vena caval flows than normal controls (p < 0.05). Six fetuses with CHD had brain weights at or below the 5th centile for gestational age, while none of the fetuses in the normal control group had brain weights below the 25th centile.

CONCLUSIONS

Measurement of the distribution of the fetal circulation in late gestation left-sided CHD is feasible with CMR. We demonstrated links between fetal blood flow distribution and postnatal course, and examined the relationship between fetal hemodynamics and lung and brain development. CMR enhances our understanding of pathophysiology of the fetal circulation and, with more experience, may help with the planning of perinatal management and fetal counselling.

Prenatal diagnosis of fetal congenital cystic adenomatoid malformation of the lung using three-dimensional ultrasound: comparison between the 20th and 21st centuries

OBJECTIVE

Congenital cystic adenomatoid malformation of the lung (CCAML) is one of the most common lung lesions diagnosed prenatally. In order to compare the trends and improvements of prenatal diagnosis of CCAML, we herein retrospectively reviewed our cases of fetal CCAML detected by three-dimensional ultrasound (3-D US) between two centuries.

MATERIALS AND METHODS

We reviewed our computer database of prenatal diagnosis of CCAML in National Cheng Kung University Hospital from October 1994 to November 2011. All of the fetuses were initially scanned by two-dimensional (2-D) US to locate the region-of-interest (ROI). Then, the 3-D probe was used to scan all of the ROI systematically and mechanically, and the images were stored in the laser discs for further 3-D visualization and reconstruction. To compare the characteristics at prenatal diagnosis of CCAML between the 20th and 21st centuries in our hospital, Chi-square tests were undertaken. A p value <0.05 was considered as statistically significant.

RESULTS

In total, 58 fetuses with CCAML were depicted by 3-D US in utero (12 cases were diagnosed in the 20th century and 46 cases in the 21st century). The ranges of gestational age at prenatal diagnosis of CCAML by 3-D US in the 20th century were between 15 and 36 weeks (mean=24 weeks), and were between 16 and 31 weeks (mean=22 weeks) in the 21st century. Moreover, nine cases (75%) were diagnosed at the second trimester in the 20th century, whereas 44 cases (96%) were diagnosed at the second trimester in the 21st century.

CONCLUSION

The advancement of 3-D US has remarkable advantages in adding novel visual depiction of a 3-D lesion of a 3-D fetus in 3-D US after reconstruction, and thus assists substantially in the prenatal diagnosis and genetic consultation of CCAML. Furthermore, the trend analysis in this series showed a significantly earlier gestational age at prenatal diagnosis of CCAML in the 21st century than that in the 20th century.

Space occupying lesions in the fetal chest evaluated by MRI

Background

The most common space occupying lesions of the fetal thorax are congenital diaphragmatic hernia (CDH), congenital cystic adenomatoid malformation (CCAM), and bronchopulmonary sequestration (BPS). Although applications of prenatal MRI have been vastly improved in the recent years, its use in the assessment of space occupying lesions of the fetal chest differs among centers.

Objectives

To evaluate MRI findings in the diagnosis and follow-up of space-occupying lesions in the fetal chest with the review of relevant literature.

Patients and Methods

The fetuses with space-occupying lesions of the chest were retrieved from our 1.5T fetal MRI database of 347 patients. MRI features including the shape, signal characteristics, feeding artery, margin, mass effect, affected organ parts and anatomic location were reviewed. The results were correlated with the pathology results, follow-up and surgical findings.

Results

Nineteen MR images of 17 fetuses (mean gestational age, 23.8 weeks) with spaceoccupying lesions (5 CCAMs including one involuted case), 2 BPSs, 2 hybrid lesions, 8 CDH) were evaluated. One case of CCAM completely involuted in utero, four newborns were operated, and the resulting 12 fetuses were terminated. The surgical and pathological findings were in accordance with MRI findings.

Conclusion

MRI can reliably differentiate CDH from CCAM and BPS in utero. Follow-up is of utmost importance as lesions may involute or progress in utero. Prenatal MRI findings help postnatal decision-making, surgical planning and parental counseling.

Fetal MR in the evaluation of pulmonary and digestive system pathology

BACKGROUND

Prenatal awareness of an anomaly ensures better management of the pregnant patient, enables medical teams and parents to prepare for the delivery, and is very useful for making decisions about postnatal treatment. Congenital malformations of the thorax, abdomen, and gastrointestinal tract are common. As various organs can be affected, accurate location and morphological characterization are important for accurate diagnosis.

METHODS

Magnetic resonance imaging (MRI) enables excellent discrimination among tissues, making it a useful adjunct to ultrasonography (US) in the study of fetal morphology and pathology.

RESULTS

MRI is most useful when US has detected or suspected anomalies, and more anomalies are detected when MRI and US findings are assessed together.

CONCLUSION

We describe the normal appearance of fetal thoracic, abdominal, and gastrointestinal structures on MRI, and we discuss the most common anomalies involving these structures and the role of MRI in their study.

TEACHING POINTS

• To learn about the normal anatomy of the fetal chest, abdomen, and GI tract on MRI. • To recognize the MR appearance of congenital anomalies of the lungs and the digestive system. • To understand the value of MRI when compared to US in assessing fetal anomalies.

Prenatal diagnosis of congenital lung malformations

Prenatal diagnosis of congenital lung anomalies has increased in recent years as imaging methods have benefitted from technical improvements. The purpose of this pictorial essay is to illustrate typical imaging findings of a wide spectrum of congenital lung anomalies on prenatal US and MRI. Moreover, we propose an algorithm based on imaging findings to facilitate the differential diagnosis, and suggest a follow-up algorithm during pregnancy and in the immediate postnatal period.

The fetal magnetic resonance imaging experience in a large community medical center

Fetal magnetic resonance imaging (MRI) continues to prove a useful problem solving tool for diagnostic and management decision making issues encountered in the antenatal period. In this paper, we attempt to review basic fetal MRI protocol considerations and demonstrate key imaging findings through multiple modalities, with pathologic correlation in several cases. A study of five fetal MRI cases, from our institution, were selected in order to highlight both the indications for, and benefits obtained from this advanced imaging technique. Fetal MRI proved useful in each case in better defining fetal anomalies, especially where ultrasound (due to drawbacks such as shadowing by pelvic bones) was unable to be completely diagnostic. The more in-depth study made possible by MRI also helped with formulation of disease prognosis and estimation of survival chances of the fetus. Further, MRI as a diagnostic and prognostic tool has become more ubiquitous across the medical community. This imparts tangible benefit to patients, who are now able to find this service within arm's reach. Whereas previously these patients were obligatorily referred up to 90 miles away from our centre for further medical work-up, now a large percentage can obtain their prenatal imaging and perinatal care locally. In addition, medical education benefits as new types of cases, those with pathology of the antenatal period, are retained for work-up and management in these large community settings. Cases from our institution exemplify these types of pathologies, from fetal chest masses to a syndromic presentation of bilateral renal agenesis.