Unusual pediatric lung infections: imaging findings.

Pediatric lung infections continue to be a leading cause of pediatric morbidity and mortality. Although both pediatric and general radiologists are familiar with typical lung infections and their imaging findings in children, relatively rare lung infections continue to present a diagnostic challenge. In addition, the advances in radiological imaging and emergence of several new lung infections in recent years facilitated the need for up-to-date knowledge on this topic. In this review article, we discuss the imaging findings of pediatric lung infections caused by unusual/uncommon and new pathogens. We review the epidemiological, clinical, and radiological imaging findings of viral (coronavirus disease 2019, Middle East respiratory syndrome, bird flu), bacterial (Streptococcus anginosus, Francisella tularensis, Chlamydia psittaci), and parasitic lung infections (echinococcosis, paragonimiasis, amoebiasis). Additional disorders whose clinical course and imaging findings may mimic lung infections in children (hypersensitivity pneumonitis, pulmonary hemorrhage, eosinophilic pneumonia) are also presented, to aid in differential diagnosis. As the clinical presentation of children with new and unusual lung infections is often non-specific, imaging evaluation plays an important role in initial detection, follow-up for disease progression, and assessment of potential complications.

Pulmonary imaging in coronavirus disease 2019 (COVID-19): a series of 140 Latin American children.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which resulted in the worldwide coronavirus disease 2019 (COVID-19) pandemic of 2020, has particularly affected Latin America. OBJECTIVE: The purpose of the study was to analyze the imaging findings of pulmonary COVID-19 in a large pediatric series. MATERIALS AND METHODS: Children with SARS-CoV-2 infection confirmed by either quantitative reverse transcription-polymerase chain reaction from nasopharyngeal swabs or presence of circulating immunoglobulin M (IgM) antibodies and who underwent chest radiograph or CT or both were included in this retrospective multicenter study. Three pediatric radiologists independently reviewed radiographs and CTs to identify the presence, localization, distribution and extension of pulmonary lesions. RESULTS: We included 140 children (71 female; median age 6.3 years, interquartile range 1.6-12.1 years) in the study. Peribronchial thickening (93%), ground-glass opacities (79%) and vascular engorgement (63%) were the most frequent findings on 131 radiographs. Ground-glass opacities (91%), vascular engorgement (84%) and peribronchial thickening (72%) were the most frequent findings on 32 CTs. Peribronchial thickening (100%), ground-glass opacities (83%) and pulmonary vascular engorgement (79%) were common radiograph findings in asymptomatic children (n=25). Ground-glass opacity and consolidation were significantly higher in children who needed intensive care admission or died (92% and 48%), in contrast with children with a favorable outcome (71% and 24%, respectively; P<0.05). CONCLUSION: Asymptomatic children and those with mild symptoms of COVID-19 showed mainly peribronchial thickening, ground-glass opacities and pulmonary vascular engorgement on radiographs. Ground-glass opacity and consolidation were more common in children who required intensive care admission or died.

Zika Virus Infection in Pregnant Women in Rio de Janeiro.

BACKGROUND: Zika virus (ZIKV) has been linked to central nervous system malformations in fetuses. To characterize the spectrum of ZIKV disease in pregnant women and infants, we followed patients in Rio de Janeiro to describe clinical manifestations in mothers and repercussions of acute ZIKV infection in infants. METHODS: We enrolled pregnant women in whom a rash had developed within the previous 5 days and tested blood and urine specimens for ZIKV by reverse-transcriptase-polymerase-chain-reaction assays. We followed women prospectively to obtain data on pregnancy and infant outcomes. RESULTS: A total of 345 women were enrolled from September 2015 through May 2016; of these, 182 women (53%) tested positive for ZIKV in blood, urine, or both. The timing of acute ZIKV infection ranged from 6 to 39 weeks of gestation. Predominant maternal clinical features included a pruritic descending macular or maculopapular rash, arthralgias, conjunctival injection, and headache; 27% had fever (short-term and low-grade). By July 2016, a total of 134 ZIKV-affected pregnancies and 73 ZIKV-unaffected pregnancies had reached completion, with outcomes known for 125 ZIKV-affected and 61 ZIKV-unaffected pregnancies. Infection with chikungunya virus was identified in 42% of women without ZIKV infection versus 3% of women with ZIKV infection (P<0.001). Rates of fetal death were 7% in both groups; overall adverse outcomes were 46% among offspring of ZIKV-positive women versus 11.5% among offspring of ZIKV-negative women (P<0.001). Among 117 live infants born to 116 ZIKV-positive women, 42% were found to have grossly abnormal clinical or brain imaging findings or both, including 4 infants with microcephaly. Adverse outcomes were noted regardless of the trimester during which the women were infected with ZIKV (55% of pregnancies had adverse outcomes after maternal infection in the first trimester, 52% after infection in the second trimester, and 29% after infection in the third trimester). CONCLUSIONS: Despite mild clinical symptoms in the mother, ZIKV infection during pregnancy is deleterious to the fetus and is associated with fetal death, fetal growth restriction, and a spectrum of central nervous system abnormalities. (Funded by Ministério da Saúde do Brasil and others.).

Back to Fundamentals: Radiographic Evaluation of Thoracic Lines and Tubes in Children.

OBJECTIVE. The purpose of this article is to provide an up-to-date review of the radiographic appearance of the most commonly used thoracic lines and tubes in pediatric patients in daily clinical practice. CONCLUSION. Thoracic support lines and tubes are frequently used in children receiving hospital care. Evaluation of these devices is a fundamental skill in radiology. Many different devices are currently used, and new devices are regularly introduced. It is essential for radiologists to maintain a clear understanding of all devices currently in use.

Applicability of Magnetic Resonance Imaging in the Assessment of Fetal Urinary Tract Malformations.

OBJECTIVE: To assess the applicability of magnetic resonance imaging (MRI) to complement ultrasound in the diagnosis of fetal urinary tract anomalies. METHODS: This was a retrospective cohort study that included 41 women between 19 weeks and 37 weeks and 6 days of gestation carrying fetuses with malformations of the urinary tract which were initially diagnosed by ultrasound and then referred for MRI. In all cases, the diagnosis was confirmed after birth either through imaging or autopsy. A surface coil was positioned over the abdomen and T2-weighted sequences were obtained in the axial, coronal, and sagittal planes; T1 in at least one plane; and three-dimensional (3-D) TRUFI in fetuses with dilatation of the urinary tract. RESULTS: Mean gestational age at the time of MRI examination was 28.21 weeks. The rapid T2 sequences allowed all the anomalies of the fetal urinary tract to be assessed, whereas 3-D TRUFI sequencing proved very useful in evaluating anomalies involving dilatation of the urinary tract. The signs of pulmonary hypoplasia characterized by hypointense signal in the T2-weighted sequences were identified in 13 of the 41 fetuses. CONCLUSION: MRI confirmed and added information to the ultrasound regarding fetal urinary tract anomalies, as well as information related to the other associated malformations, their progress in the prenatal period, and possible postnatal prognosis.

Prenatal diagnosis of Apert syndrome using ultrasound, magnetic resonance imaging, and three-dimensional virtual/physical models: three case series and literature review.

OBJECTIVE: This aimed to describe the prenatal diagnosis of three cases of Apert syndrome using two-dimensional (2D) and three-dimensional (3D) ultrasound, magnetic resonance imaging (MRI), and 3D virtual/physical models. METHODS: We retrospectively analyzed three cases of Apert syndrome at our service. The prenatal diagnostic methods used were 2D ultrasound, 3D ultrasound in conventional and HDlive rendering modes, T2-weighted MRI sequences, and 3D virtual/physical models from MRI or 3D ultrasound scan data. All imaging methods were performed by one observer. All prenatal diagnoses were confirmed by autopsy in cases of termination of pregnancy or genetic assessment during the postnatal period. RESULTS: Mean ± standard deviation of maternal and gestational age at the time of diagnosis was 36.5 ± 3.5 years and 32 ± 4.2 weeks, respectively. Main 2D/3D ultrasound and MRI findings were craniosynostosis, hypertelorism, low ear implantation, increased kidneys dimensions, and syndactyly of hands and feet. 3D virtual/physical models allowed 3D view of fetal head and extremity abnormalities. Termination of pregnancy occurred in two cases. CONCLUSION: Prenatal 3D ultrasound and MRI enabled the identification of all Apert syndrome phenotypes. 3D virtual/physical models provided both the parents and the medical team a better understanding of fetal abnormalities.

Central Nervous System Effects of Intrauterine Zika Virus Infection: A Pictorial Review.

Relatively few agents have been associated with congenital infections involving the brain. One such agent is the Zika virus, which has caused several outbreaks worldwide and has spread in the Americas since 2015. The Zika virus is an arbovirus transmitted by infected female mosquito vectors, such as the Aedes aegypti mosquito. This virus has been commonly associated with congenital infections of the central nervous system and has greatly increased the rates of microcephaly. Ultrasonography (US) remains the method of choice for fetal evaluation of congenital Zika virus infection. For improved assessment of the extent of the lesions, US should be complemented by magnetic resonance (MR) imaging. Postnatal computed tomography and MR imaging can also unveil additional findings of central nervous system involvement, such as microcephaly with malformation of cortical development, ventriculomegaly, and multifocal calcifications in the cortical-subcortical junction, along with associated cortical atrophy. The calcifications may be punctate, dystrophic, linear, or coarse and may follow a predominantly bandlike distribution. A small anterior fontanelle with prematurely closed sutures is also observed with Zika virus infection. In this review, the prenatal and postnatal neurologic imaging findings of congenital Zika virus infection are covered. Radiologists must be aware of this challenging entity and have knowledge of the various patterns that may be depicted with each imaging modality and the main differential diagnosis of the disease. As in other neurologic infections, serial imaging is able to help demonstrate the progression of the findings. ©RSNA, 2017.

Neuroimaging Findings of Congenital Toxoplasmosis, Cytomegalovirus, and Zika Virus Infections: A Comparison of Three Cases.

OBJECTIVE: Toxoplasmosis, cytomegalovirus (CMV), and Zika virus (ZIKV) are among the common infectious agents that may infect the fetuses vertically. Clinical presentations of these congenital infections overlap significantly, and it is usually impossible to determine the causative agent clinically. The objective was the comparison of neuroimaging findings in three fetuses who underwent intrauterine infection by toxoplasmosis, CMV, and ZIKV. METHODS: Three confirmed cases of congenital toxoplasmosis, CMV, and ZIKV infections were included in the study over 7 months prospectively. Prenatal ultrasound, fetal brain MRI, and postnatal neuroimaging (CT or MRI) were performed on all of the included cases and interpreted by an expert radiologist. RESULTS: The mean GA at the time of prenatal imaging was 34.5 ± 3.5 weeks. The main neuroimaging findings in congenital toxoplasmosis were randomly distributed brain calcifications and ventricular dilatation on ultrasounds (US), as well as white matter signal change on fetal brain MRI. The main neuroimaging findings of congenital CMV infection included microcephaly, ventriculomegaly, and periventricular calcifications on US, as well as pachygyria revealed by fetal MRI. The case of congenital ZIKV infection showed microcephaly, ventriculomegaly, and periventricular calcifications on ultrasound, as well as brain atrophy and brain surface smoothness on fetal MRI. CONCLUSION: Although the neuroimaging findings in congenital infections are not pathognomonic, in combination with the patient history may be suggestive of one of the infectious agents, which will guide the management strategy.

Prenatal Diagnosis of Caroli Disease Associated With Autosomal Recessive Polycystic Kidney Disease by 3-D Ultrasound and Magnetic Resonance Imaging.

BACKGROUND: Caroli disease is a very rare congenital anomaly characterized by non-obstructive saccular or fusiform dilatation of the intrahepatic bile ducts. It is associated with bile stagnation and hepatolithiasis, which explain the recurrent cholangitis and portal hypertension as a consequence of congenital liver fibrosis. Although there are several reports of diagnosis in childhood and adult life, the prenatal diagnosis using conventional 2-D ultrasound is rare, with few reports in the literature. CASE: We present a case of a 26-year-old primigravid woman at 24 weeks of gestation which 3-D ultrasound in the rendering mode clearly revealed the enlarged fetal kidneys and the increased abdominal volume, confirming the diagnosis of autosomal recessive polycystic kidney disease. The MRI was essential to the prenatal diagnosis of Caroli disease, identifying the congenital saccular dilations of intrahepatic bile ducts.

Standardized radiographic interpretation of thoracic tuberculosis in children.

There is a lack of standardized approach and terminology to classify the diverse spectrum of manifestations in tuberculosis. It is important to recognize the different clinical and radiographic patterns to guide treatment. As a result of changing epidemiology, there is considerable overlap in the radiologic presentations of primary tuberculosis and post-primary tuberculosis. In this article we promote a standardized approach in clinical and radiographic classification for children suspected of having or diagnosed with childhood tuberculosis. We propose standardized terms to diminish confusion and miscommunication, which can affect management. In addition, we present pitfalls and limitations of imaging.

Visualisation of the vascular equator in twin-to-twin transfusion syndrome by virtual fetoscopy.

BACKGROUND: Twin-to-twin transfusion syndrome (TTTS) is a serious complication of monochorionic twin gestation, which has a high risk of perinatal morbidity and mortality. Fetoscopic laser photocoagulation of the vascular anastomoses is the preferred treatment. Nowadays, Solomon technique which consists the vascular coagulation of all anastomoses in the placental equator is the preferable method. OBJECTIVE: To develop a method of virtual fetoscopy by means of ultrasound and resonance magnetic imaging (MRI) scan data to allow the identification of placental equator. RESULTS: MRI was performed in a twin monochorionic twin pregnancy with 28 weeks previously treated for TTTS with fetoscopic laser photocoagulation. A three-dimensional (3D) file of the placenta was created from overlapping image layers generated by MRI using Mimics software. Virtual fetoscopy allowed adequate visualization of fetuses, umbilical cord insertion and placental equator. CONCLUSION: Virtual fetoscopy is a non-invasive technique which allowed adequate identification of placental equator, and it may be an important learning method to novice fetal endoscopic surgeons in TTTS cases.

Neonatal and Infant Lung Disorders: Glossary, Practical Approach, and Diagnoses.

A multitude of lung disorders ranging from congenital and genetic anomalies to iatrogenic complications can affect the neonate or the infant within the first year of life. Neonatal and infant chest imaging, predominantly by plain radiography and computed tomography, is frequently employed to aid in diagnosis and management; however, these disorders can be challenging to differentiate due to their broad-ranging, and frequently overlapping radiographic features. A systematic and practical approach to imaging interpretation which includes recognition of radiologic patterns, utilization of commonly accepted nomenclature and classification, as well as interpretation of imaging findings in conjunction with clinical history can not only assist radiologists to suggest the diagnosis, but also aid clinicians in management planning. The contents of this article were endorsed by the leadership of both the World Federation of Pediatric Imaging (WFPI), and the International Society of Pediatric Thoracic Imaging (ISPTI).

Advanced large airway CT imaging in children: evolution from axial to 4-D assessment.

Continuing advances in multidetector computed tomography (MDCT) technology are revolutionizing the non-invasive evaluation of congenital and acquired large airway disorders in children. For example, the faster scanning time and increased anatomical coverage that are afforded by MDCT are especially beneficial to children. MDCT also provides high-quality multiplanar 2-dimensional (2-D), internal and external volume-rendering 3-dimensional (3-D), and dynamic 4-dimensional (4-D) imaging. These advances have enabled CT to become the primary non-invasive imaging modality of choice for the diagnosis, treatment planning, and follow-up evaluation of various large airway disorders in infants and children. It is thus essential for radiologists to be familiar with safe and effective techniques for performing MDCT and to be able to recognize the characteristic imaging appearances of large airway disorders affecting children.

Pulmonary infections.

This paper reviews the most common imaging findings of pulmonary infection in children. Pneumonia is a leading cause of mortality in children in developing and industrialized countries. While the imaging findings usually are nonspecific, correlation with the patient's age, immune status and pertinent history can limit the differential diagnoses. The paper will review the common and unique features of pneumonia caused by specific organisms and in specific patient populations.

Symmetric and ventrally conjoined twins: prenatal evaluation by ultrasound and magnetic resonance imaging and postnatal outcomes.

OBJECTIVE: To review the perinatal and long-term outcomes of symmetric and ventrally conjoined twins evaluated prenatally by ultrasound and fetal magnetic resonance imaging (MRI). METHODS: From March 2010 to January 2019, cases of symmetric and ventrally conjoined twins, who were prenatally diagnosed and referred to the Clínica Diagnóstico por Imagem (CDPI), Rio de Janeiro, Brazil, for prenatal evaluation by ultrasound and MRI were selected. The postnatal information was collected from hospitals where the twins were born and/or treated and from parents' verbal and written information. RESULTS: Four cases of symmetrical and ventrally conjoined twins were selected. Of these, two were omphalopagi and two thoracopagi. One pair of thoracomphalopagus died early in utero and the other died 6 days after birth. The outcome of the two omphalopagus pairs were separation in emergency surgeries after birth, with neonatal demise of one of the twins due to congenital malformations. In cases of omphalopagi, fetal MRI presented important information of the twins' anatomy before emergency separation of both pairs. CONCLUSION: Despite the apparently similar conditions of twins with ventral fusion, ventrally attached twins have very different outcomes, most adverse for thoracomphalopagus and related to the singular anatomy of the pair, associated malformations and the extension of the adhesion, requiring individual evaluation of the cases. Fetal MRI is as an important tool for the postnatal surgery management of twin neonates, providing crucial information in cases where urgent separation is required.

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.

OBJETIVO: Analisar os achados na tomografia computadorizada (TC) de tórax de 23 pacientes com atresia brônquica. MATERIAIS E MÉTODOS: As imagens de TC foram avaliadas por dois observadores e os casos discordantes foram resolvidos por consenso. Os critérios de inclusão foram a presença de anormalidades na TC compatíveis com atresia brônquica e/ou diagnóstico confirmado por exame anatomopatológico das peças cirúrgicas para os pacientes submetidos a ressecção cirúrgica. As TCs foram avaliadas quanto aos principais achados de imagem, à distribuição das lesões, ao envolvimento pulmonar unilateral ou bilateral. RESULTADOS: Os principais achados na TC foram a presença de broncocele, hiperinsuflação do parênquima pulmonar ou ambos. A combinação desses achados foi encontrada em todos os pacientes. Em relação à distribuição, o envolvimento foi unilateral nos 23 casos. Quando se consideraram os lobos mais acometidos, o lobo superior esquerdo foi o mais acometido, seguido do lobo inferior direito, lobo superior direito, lobo médio e lobo inferior esquerdo. CONCLUSÃO: O diagnóstico de atresia brônquica pode ser feito em presença de broncocele associada com hiperinsuflação do parênquima pulmonar adjacente.