Search

Childhood interstitial lung disease (chILD) encompasses a diverse group of genetic, infectious, and inflammatory conditions affecting infants and children. The recognition and understanding of these entities have highlighted the necessity for more accurate classification. This group of rare heterogeneous diseases comprises more than 200 different conditions and has a combined estimated prevalence of less than one patient per 100 000 children. Hence, a systematic diagnostic approach is crucial. This article describes a diagnostic approach for pediatric diffuse lung diseases in infancy, including an analysis of clinical presentations and imaging and histologic features to effectively distinguish among various chILD entities. Although they often have overlapping and nonspecific radiologic features, some chILD entities may exhibit typical imaging findings, resulting in a CT diagnosis or aiding in narrowing the differential diagnosis, thus guiding the clinician to the appropriate genetic tests, potentially limiting unnecessary biopsies. This approach aims to enhance the understanding and diagnosis of chILD in infants, thereby facilitating improved patient care., (© RSNA, 2024.)

Magnetic resonance imaging (MRI) is now an indispensable diagnostic tool in medicine due to its outstanding contrast resolution and absence of radiation exposure, enabling detailed tissue characterization and three-dimensional anatomical representation. This is especially important when evaluating individuals with congenital heart disease (CHD) who frequently require cardiac implantable electrical devices (CIEDs). While MRI safety issues have previously limited its use in patients with CIEDs, new advances have called these limitations into question. However, difficulties persist in the pediatric population due to the continued lack of specific safety data both related to imaging young children and the specific CIED devices they often require. This paper discusses MRI safety considerations related to imaging patients with CIEDs, investigates pediatric-specific problems, and describes thorough methods for safe MRI access, highlighting the significance of specialized institutional guidelines., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Tracheomalacia (TM) is an important cause of respiratory morbidity. Dynamic flexible bronchoscopy is considered the gold standard for diagnosis. Dynamic airway computed tomography (DACT) is a low radiation, noninvasive diagnostic tool utilizing images obtained continuously over several respiratory cycles. We aimed to assess the accuracy of DACT in TM diagnosis., Methods: Retrospective analysis of all patients who underwent both DACT and flexible bronchoscopy within 6 months. Airway anterior-posterior (AP) diameter was measured on multiplanar reconstructions CT in both the inspiratory and expiratory phases. Using still images from the bronchoscopy videos, the AP diameter of the trachea was measured at points of maximal and minimal diameter during tidal breathing. Degree of TM on both DACT and flexible bronchoscopy were graded using a scaling system of 50%-74%, 75%-89%, and 90%-100% as described by the European Respiratory Society., Results: Twenty-four patients met inclusion criteria with an average time of 19.5 days between CT and bronchoscopy. The specificity and sensitivity of DACT for the overall diagnosis of TM was 100% and 68%, respectively, with a positive predictive value of 100% and a negative predictive value of 62%. There was a strong positive correlation between DACT and flexible bronchoscopy in the measurement of tracheal AP diameter changes (ρ = 0.773, R 2 0.597, p = 0.00001). Mean effective radiation dose for DACT was 0.1 mSv., Conclusion: Ultralow dose DACT has excellent specificity and positive predictive value for both detection of TM and categorizing severity of tracheal collapse but is not sufficiently sensitive to rule it out., (© 2024 Wiley Periodicals LLC.)

Introduction: Radiation-induced lung injury is a rare complication of radioactive iodine therapy (RAIT) in pediatric thyroid cancer treatment. In this case report, we describe a pediatric patient with an ERC1::RET-positive classic papillary thyroid carcinoma who developed progressive respiratory symptoms and chest imaging abnormalities following RAIT for lymph node and pulmonary disease., Case Presentation: A pediatric patient with ERC1::RET-positive classic papillary thyroid carcinoma was hospitalized for pulmonary decompensation 3 months following one empiric dose of RAIT. Testing revealed no evidence of infection or progression of pulmonary metastases, and there was no improvement with empiric antibiotic therapy for pneumonia. Despite empiric anti-inflammatory therapies, the patient remains symptomatic from a respiratory standpoint with requirement for supplemental oxygen and evidence of fibrotic changes on chest imaging., Conclusions: This patient's pulmonary condition is consistent with radiation-induced pulmonary injury including development of pulmonary fibrosis. With the availability of RET fusion-targeted inhibitors, this case highlights a rare pulmonary side effect of radioactive iodine for clinicians to recognize. Upfront targeted therapy protocols may help avoid radioactive iodine-associated adverse reactions., (© 2023 S. Karger AG, Basel.)

Dual-energy CT has expanded the potential of thoracic imaging in both children and adults. Data processing allows material- and energy-specific reconstructions, which improve material differentiation and tissue characterization compared with single-energy CT. Material-specific reconstructions include iodine, virtual unenhanced, perfusion blood volume, and lung vessel images, which can improve assessment of vascular, mediastinal, and parenchymal abnormalities. The energy-specific reconstruction algorithm allows virtual monoenergetic reconstructions, including low-energy images to increase iodine conspicuity and high-energy images to reduce beam-hardening and metal artifacts. This review highlights dual-energy CT principles, hardware, and postprocessing algorithms; the clinical applications of dual-energy CT; and the potential benefits of photon counting (the most recently introduced iteration of spectral imaging) in pediatric thoracic imaging.

The lymphatic system has been poorly understood and its importance neglected for decades. Growing understanding of lymphatic flow pathophysiology through peripheral and central lymphatic flow imaging has improved diagnosis and treatment options in children with lymphatic diseases. Flow dynamics can now be visualized by different means including dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL), the current standard technique to depict central lymphatics. Novel imaging modalities including intranodal, intrahepatic and intramesenteric DCMRL are quickly evolving and have shown important advances in the understanding and guidance of interventional procedures in children with intestinal lymphatic leaks. Lymphatic imaging is gaining importance in the radiologic and clinical fields and new techniques are emerging to overcome its limitations., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The gold standard for pediatric chest imaging remains the CT scan. An ideal pediatric chest CT has the lowest radiation dose with the least motion degradation possible in a diagnostic scan. Because of the known inherent risks and costs of anesthesia, non-sedate options are preferred. Dual-source CTs are currently the fastest, lowest-dose CT scanners available, utilizing an ultra-high-pitch mode resulting in sub-second CTs. The dual-energy technique, available on dual-source CT scanners, gathers additional information such as pulmonary blood volume and includes relative contrast enhancement and metallic artifact reduction, features that are not available in high-pitch flash mode. In this article we discuss the benefits and tradeoffs of dual-source CT scan modes and tips on image optimization., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The presence of airway and lung disease in children with congenital heart disease is commonly observed with both cardiac CT angiography and routine chest CT. In this review we discuss abnormalities encountered on CT imaging of the chest beyond the heart and central vasculature, focusing on the airways, lung parenchyma and peripheral vasculature. Preoperative and postoperative findings are reviewed as well., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Computed tomography technology continues to undergo evolution and improvement with each passing decade. From its inception in 1971, to the advent of commercially available dual-energy CT just over a decade ago, and now to the latest innovation, photon-counting detector CT, CT's utility for resolving and discriminating tissue types improves. In this review we discuss the impact of spectral imaging, including dual-energy CT and the recently available photon-counting detector CT, on the imaging of the pediatric chest. We describe the current capabilities and future directions of CT imaging, encompassing both the lungs and the surrounding tissues., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Children with single-ventricle congenital heart disease undergo a series of operations to maintain their pulmonary circulation including bidirectional Glenn (BDG) or hemi-Fontan in the second stage to create a superior cavopulmonary anastomosis. We aimed to optimize cardiovascular angiography protocols by determining optimal contrast timing of pulmonary and systemic circulation on magnetic resonance angiography (MRA) performed with the technique of time-resolved imaging with interleaved stochastic trajectories (TWIST)., Methods and Materials: Cardiac TWIST MRA with lower extremity (LE) contrast injection was analyzed in 92 consecutive patients with a BDG or hemi-Fontan anastomosis. Contrast arrival time to inferior vena cava was set to zero to determine the relative time-to-peak (TTP) of the target vessels. Time-to-peak of each vessel was compared by age (<2 or ≥2 y), ejection fraction (<54% or ≥54%), the median values of heart rate (<111 or ≥111 beats per minute), body surface area (BSA, <0.59 or ≥0.59), cardiac index (<6.04 or ≥6.04), and indexed ascending aorta flow (AscAo&#95;i, <5.3 or ≥5.3). The TTP of the vessels was also correlated with the volumetric parameters., Results: The mean age of 92 patients (32 female, 60 male) was 3.1 years (0.7-5.6 years). With LE injection, the first peak was depicted in AscAo. Time-to-peak of the pulmonary arteries was approximately 9 seconds later than AscAo. The TTP difference between pulmonary arteries and AscAo was shorter in high heart rate group (8.3 vs 10 seconds, P < 0.001). The TTP difference between AscAo and the mean of pulmonary arteries was significantly shorter in high cardiac index group (8.4 vs 9.9 seconds, P < 0.01) and high AscAo&#95;i group (8.7 vs 9.7 seconds, P = 0.03). The TTP differences were not significant by age, ejection fraction, and BSA. Cardiac index and AscAo&#95;i were negatively correlated with all TTPs except AscAo. The ejection fraction, stroke volume, and atrioventricular regurgitation fraction did not correlate with the TTP., Conclusions: In patients with BDG or hemi-Fontan anastomosis, TTP of the pulmonary arteries on TWIST MRA via LE intravenous injection is approximately 9 seconds later than AscAo, approximately 8 and 10 seconds later in high and low heart rate groups, respectively. Cardiac index and AscAo&#95;i have less effect on the TTP than the heart rate. There was no TTP difference of the pulmonary arteries by age, BSA, and ejection fraction and no correlation with ejection fraction, stroke volume, and atrioventricular regurgitation fraction. These data can be used to guide timing of pulmonary arterial enhancement of single-ventricle patients after BDG or hemi-Fontan anastomosis., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Congenital heart disease can lead to various lymphatic complications including traumatic leaks, lymphatic overproduction, conduction abnormalities or lymphedema. Advancements in the imaging of central lymphatics and guided interventions have improved outcomes in these children. Dynamic contrast-enhanced magnetic resonance (MR) lymphangiography allows for the assessment of abnormal lymphatic drainage. This technique is preferred for evaluating lymphatic conditions such as plastic bronchitis, chylothorax, chyloptysis, chylopericardium, protein-losing enteropathy and chylous ascites, among other lymphatic disorders. In this review, we discuss lymphatic abnormalities encountered on MRI in children with congenital heart disease. We also briefly review treatment options., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Amid the coronavirus disease 2019 (COVID-19) pandemic, numerous publications of imaging findings in children have surfaced in a very short time. Publications discuss populations of overlapping age groups and describe different imaging patterns. We aim to present an overview of the quantity and type of literature available regarding COVID-19 chest imaging findings in children according to a 2020 publication timeline. We conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. We searched terminology related to COVID-19, chest, children and imaging modalities in PubMed and Embase. The included papers were published online in 2020 and described imaging findings specific to children and reported five or more cases. Two researchers reviewed each abstract to determine inclusion or exclusion, and a radiologist reconciled any disagreements. Then we reviewed full articles for the main analysis. Eligible study designs included original articles, case series (≥5 cases), systematic reviews and meta-analyses. We excluded non-English manuscripts, retracted articles, and those without available full text. The remaining articles were distributed to four pediatric radiologists (on the Society for Pediatric Radiology Thoracic Committee), who summarized chest imaging findings. Eighty-two articles were included in the final analysis - 28% in radiology journals and 71% in non-radiology journals; 71% contained original data and 29% were review-style papers. There was a disproportionate contribution of review-style papers in April (55%), considering the paucity of preceding publications with original data in March (5 papers). June had the highest number of publications (n=14), followed by April (n=11) and July (n=11). Most (52%) original papers were from China and most individual pediatric imaging descriptions were from China (57%), while the majority of review papers (83%) were international. Imaging descriptions were available for 2,199 children (1,678 CT descriptions and 780 chest radiography descriptions). Findings included a 25% normal CT scan reports vs. 40% normal chest radiography reports. Ground-glass opacification was the most common CT finding (33%) and was reported in only a minority of chest radiographs (9%). A significant amount of information on pediatric COVID-19 chest imaging has become rapidly available over a short period. Most publications in 2020 were original articles, but they were published more often in non-radiology journals. A disproportionate number of review articles were published early on and were based on little original pediatric imaging data. CT scan reports, which represent the standard, outnumbered radiographic reports and indicated that ground-glass opacification is the main imaging finding and that only a quarter of scans are normal in children with COVID-19., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Magnetic resonance imaging (MRI) and CT perform an important role in the evaluation of neonates with congenital heart disease (CHD) when echocardiography is not sufficient for surgical planning or postoperative follow-up. Cardiac MRI and cardiac CT have complementary applications in the evaluation of cardiovascular disease in neonates. This review focuses on the indications and technical aspects of these modalities and special considerations for imaging neonates with CHD., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To assess the feasibility of direct intra-lymphatic administration of diluted ferumoxytol as a T1-positive contrast agent for dynamic contrast-enhanced MR lymphangiography (DCMRL) imaging of the central lymphatics in children with renal disease., Methods: In vitro scan of dilute ferumoxytol was initially performed using time-resolved and high-resolution 3D gradient echo (GRE) sequences with short TE values (1 to 1.5 ms). A ferumoxytol concentration of 0.25 to 0.40 mg/mL was found to retain high signal in the T1-weighted sequences. DCMRL was then performed in 4 children with renal disease with the same 3D GRE sequences administrating diluted ferumoxytol via intra-mesenteric (IM), intra-hepatic (IH), and intra-nodal (IN) routes (6 to 9 mL to each site; average total dose of 0.75 mg/kg) by slow hand injection (0.5 to 1.0 mL/min). The signal-to-noise ratio (SNR) of the lymphatics was measured for quantitative evaluation., Results: Ferumoxytol-enhanced DCMRL was technically successful in all patients. Contrast conspicuity within the lymphatics was sufficient without subtraction. The mean SNR was significantly higher than the muscle (50.1 ± 12.2 vs 13.2 ± 2.8; t = 15.9; p < .001). There were no short-term complications attributed to the administration of ferumoxytol in any of the four patients., Conclusion: Magnetic resonance lymphangiography using ferumoxytol via IN, IH, and IM access is a new method to directly visualize the central lymphatic system and can be applied safely in patients with renal failure based on our preliminary report of four cases. Ferumoxytol-enhanced DCMRL shows diagnostic image quality by using 3D GRE sequences with short TE values and appropriate dilution of ferumoxytol., Key Points: • MR lymphangiography using ferumoxytol via intra-nodal, intra-hepatic, and intra-mesenteric access is a new method to directly visualize the central lymphatic system from the groin to the venous angle. • FDCMRL can be applied safely in patients with renal failure based on our preliminary report of four cases. • FDCMRL shows diagnostic image quality by using 3D GRE sequences with short TE values and appropriate dilution of the ferumoxytol., (© 2021. This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.)

Objective: To evaluate clinical applications of dual-energy computed tomography (DECT) in pediatric-specific lung diseases and compare ventilation and perfusion findings with those from single-photon emission computed tomography (SPECT-CT) V/Q., Methods: All patients at our institution who underwent exams using both techniques within a 3-month period were included in this study. Two readers independently described findings for DECT, and two other readers independently analyzed the SPECT-CT V/Q scan data. All findings were compared between readers and disagreements were reassessed and resolved by consensus. Inter-modality agreements are described throughout this study., Results: Eight patients were included for evaluation. The median age for DECT scanning was 3.5 months (IQR = 2). Five of these patients were scanned for both DECT and SPECT-CT V/Q studies the same day, and three had a time gap of 7, 65, and 94 days between studies. The most common indications were chronic lung disease (5/8; 63%) and pulmonary hypertension (6/8; 75%). DECT and SPECT-CT V/Q identified perfusion abnormalities in concordant lobes in most patients (7/8; 88%). In one case, atelectasis limited DECT perfusion assessment. Three patients ultimately underwent lobectomy with corresponding perfusion abnormalities identified by all reviewers on both DECT and SPECT-CT V/Q in all resected lobes., Conclusion: DECT is a feasible technique that could be considered as an alternative for SPECT-CT V/Q for lung perfusion evaluation in infants., (© 2021 Wiley Periodicals LLC.)

Lymphatic flow disorders include a broad spectrum of abnormalities that can originate in the lymphatic or the venous system. The development of these disorders is multifactorial and is most commonly associated with congenital heart diseases and palliative surgeries that these patients undergo. Central lymphatic disorders might be secondary to traumatic leaks, lymphatic overproduction, conduction abnormalities or lymphedema, and they can progress to perfusion anomalies. Several imaging modalities have been used to visualize the lymphatic system. However, the imaging of central lymphatic flow has always been challenging. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) allows for visualization of central lymphatic flow disorders and has been recently applied for the assessment of plastic bronchitis, protein-losing enteropathy, chylothorax and chylopericardium, among other lymphatic disorders. The hepatic and mesenteric accesses are innovative and promising techniques for better identification and understanding of these abnormalities. The main objectives of this review are to discuss the physiology and anatomy of the lymphatic system and review the current uses of DCMRL in the diagnosis and management of lymphatic flow disorders., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Most pediatric masses in the chest are located in the mediastinum. These masses are often initially detected incidentally on chest radiographs in asymptomatic children, although some patients may present with respiratory symptoms. At chest radiography, the mediastinum has been anatomically divided into anterior, middle, and posterior compartments. However, with the International Thymic Malignancy Interest Group classification scheme, which is based on cross-sectional imaging findings, the mediastinum is divided into prevascular, visceral, and paravertebral compartments. In the prevascular compartment, tumors of thymic origin, lymphomas, germ cell tumors, and vascular tumors are encountered. In the visceral compartment, lymphadenopathy and masses related to the foregut are seen. In the paravertebral compartment, neurogenic tumors are most common. Using the anatomic location in combination with knowledge of the imaging and pathologic features of pediatric mediastinal masses aids in accurate diagnosis of these masses to guide treatment and management decisions. An invited commentary by Lee and Winant is available online. © RSNA, 2021.

Objective: To characterize the normal progression of quantitative CT parameters in normal children from birth to adulthood., Materials and Methods: Patients aged 0-18 years with non-contrast-enhanced chest CT and evidence of normal lung parenchyma were included. Patients with respiratory symptoms, incomplete anthropometric measurements, or sub-optimal imaging technique were excluded. Segmentation was performed using an open-source software with an automated threshold segmentation. The following parameters were obtained: mean lung density, kurtosis, skewness, lung volume, and mass. Linear and exponential regression models were calculated with age and height as independent variables. A p-value of <0.05 was considered significant., Results: 220 patients (111 females, 109 males) were included. Mean age was 9.6 ± 5.9 years and mean height was 133.9 ± 35.1 cm. Simple linear regression showed a significant relationship between mean lung density with age (R 2 = 0.70) and height (R 2 = 0.73). Kurtosis displayed a significant exponential correlation with age (R 2 = 0.70) and height (R 2 = 0.71). Skewness showed a significant exponential correlation with age (R 2 = 0.71) and height (R 2 = 0.73). Lung mass showed a correlation with age (R 2 = 0.93) and height (R 2 = 0.92). Exponential regression showed a significant relationship between lung volume with age (R 2 = 0.88) and height (R 2 = 0.93)., Conclusion: Quantitative CT parameters of the lung parenchyma demonstrate changes from birth to adulthood. As children grow, the mean lung density decreases, and the lung parenchyma becomes more homogenous., (Copyright © 2020 Elsevier Inc. All rights reserved.)

OBJECTIVE. The purpose of this article is to review currently available and emerging techniques for pediatric lung MRI for general radiologists. CONCLUSION. MRI is a radiation-free alternative to CT, and clearly understanding the strengths and limitations of established and emerging techniques of pediatric lung MRI can allow practitioners to select and combine the optimal techniques, apply them in clinical practice, and potentially improve early diagnostic accuracy and patient management.

Background: Imaging of novel coronavirus disease 2019 (COVID-19) has been described in adults, but children have milder forms of disease. Pediatric imaging descriptions are of asymptomatic children, raising the question of whether imaging is needed in this patient group., Objective: To describe the utilization and imaging findings in children with COVID-19 along with the comorbidities, treatment and short-term outcomes., Materials and Methods: We retrospectively reviewed pediatric patients who had a confirmed positive test for COVID-19 during a 2-month period. We noted symptoms and presence of imaging at presentation. Comorbidities were recorded for children with imaging. Children were categorized as having multisystem inflammatory syndrome in children (MIS-C) if they met criteria for the disorder. For children who were admitted to the hospital, we documented length of hospital stay, need for intensive care unit care/ventilator support, and treatment regimen. We evaluated all imaging for acute/chronic abnormalities including chest radiographs for interstitial or alveolar opacities, distribution/symmetry of disease, zonal predominance, and pleural abnormalities. We performed descriptive statistics and compared children with MIS-C with the cohort using a Fisher exact test., Results: During the study period, 5,969 children were tested for COVID-19, with 313 (5%) testing positive. Of these, 92/313 (29%) were asymptomatic and 55/313 (18%) had imaging and were admitted to the hospital for treatment. Forty-one of 55 patients (75%) with imaging had comorbidities. Chest radiographs were the most common examination (51/55 patients, or 93%) with most demonstrating no abnormality (34/51, or 67%). Children with MIS-C were more likely to have interstitial opacities and pleural effusions. US, CT or MRI was performed in 23/55 (42%) children, 9 of whom had MIS-C. Only one chest CT was performed., Conclusion: In our study, most pediatric patients with COVID-19 did not require hospital admission or imaging. Most children with imaging had comorbidities but children with MIS-C were more likely to have no comorbidities. Children with imaging mostly had normal chest radiography. Advanced imaging (US, CT, MRI) was less common for the care of these children, particularly CT examination of the chest and for children without MIS-C.

Purpose: E-cigarette or vaping product use associated lung injury (EVALI) has received national attention as an epidemic resulting in cases of significant morbidity and mortality. We aim to present the clinical and imaging findings in adolescents with pulmonary symptoms from suspected EVALI., Methods: Chest radiographs and CTs of adolescents (< 19 years) with acute pulmonary symptoms and history of vaping were reviewed by two radiologists in consensus. Clinical presentation and laboratory data were derived from the electronic medical records including pulmonary function tests (PFTs)., Results: Eleven patients were identified (9 male, mean 16.6 years). The most common presentation was progressive, subacute respiratory distress with abdominal pain. All but one of the patients tested positive for tetrahydrocannabinol. Chest radiograph features were notable for interstitial pattern of opacities (91%) and basilar abnormalities (82%). CT features were notable for ground-glass opacities (89%), interstitial opacities (78%), and subpleural sparing (67%). Eight patients underwent PFTs. Six had diffusing capacity measurement, which demonstrated impaired diffusion in 3 (50%). All patients received supportive treatment with supplemental oxygen and corticosteroids., Conclusion: Adolescents with suspected EVALI commonly present with subacute respiratory distress with abdominal pain. Imaging findings include ground-glass opacities, subpleural sparing, and basilar opacities, most consistent with organizing pneumonia or hypersensitivity pneumonitis. Recognition of the common imaging findings may have significant patient management implications, especially if the diagnosis is not suspected clinically. The lung function effects of vaping are consistent with mildly reduced airflow, which improves on follow-up testing, and reduced diffusion capacity, which, concerningly, does not improve.

Dual-energy computer tomography (DECT) technology has experienced rapid growth in recent years, now allowing for the collection of 2 CT data sets and opening the potential for functional data acquisition. Data from a single postcontrast phase are deconstructed and Iodine can be subtracted to create a virtual noncontrast image, or selectively represented as a contrast map that allows for the qualification and quantification of lung perfusion. Virtual monoenergetic images can also be used to reduce beam-hardening artifact from concentrated contrast or metal implants. In children, DECT is of particular interest because it has been shown to be dose neutral in most applications, dose-reducing in multiphase studies, and to increase the contrast to noise ratio in suboptimal studies. We review the basics of acquisition, postprocessing, and thoracic applications of DECT with a focus on pulmonary blood volumes as a surrogate for perfusion imaging. The discussed applications include pulmonary embolism, hypoplastic lung, pulmonary hypertension in bronchopulmonary dysplasia, and pediatric lung masses., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The Fontan operation or the total cavopulmonary connection is a palliative surgery for single ventricle congenital heart disease where the systemic venous return circumvents a pumping chamber and flows directly into the pulmonary circuit. With surgical and medical advances, there has been improvement in life expectancy of these patients, however, it has also resulted in unique complications from the physiology that requires diligent surveillance. A critical component relies on optimal imaging for diagnosis and treatment of these complications. This article describes the normal anatomy of the Fontan circulation, current imaging modalities and techniques, and frequently encountered complications seen when imaging the patients who have undergone Fontan palliation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

To assess the diagnostic efficiency of CT angiography (CTA) to detect pulmonary vein stenosis in children. We retrospectively identify patients between 0 and 3 years old with confirmed pulmonary vein stenosis with conventional angiography or surgery and available CTA. Patients without confirmed stenosis of the pulmonary veins were included as controls. We excluded patients with previous surgery involving the pulmonary veins, exclusively right-heart conventional angiography or insufficient data in the operation note to confirm the status of the pulmonary veins. Two pediatric radiologists evaluated and determine the presence of stenosis and the pulmonary veins affected. Disagreement between the readers were solved by consensus with a third reader. A pediatric cardiologist reviewed the available angiographic images to determine the presence of stenosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Kappa statistics was performed. 26 patients (15 boys, 11 Girls) were included. Conventional angiography (n = 20) and cardiothoracic surgery (n = 6) confirmed the diagnosis of pulmonary vein stenosis in 13 children. The diagnostic performance at patient level showed the sensitivity, specificity, PPV, and NPV were 84.6%, 92.3%, 91.6%, 87.5%, and 88.4%, respectively. The interobserver was k = 0.76. The performance at pulmonary vein level showed the sensitivity, specificity, PPV, and NPV were 63.3%, 97.4%, 90.4%,85.7% and 87.9%, respectively. The interobserver agreement was k = 0.62. Computed Tomography Angiography is an excellent and reliable image technique for ruling in pulmonary vein stenosis in young children.

A 15 year old female with a history only significant for long standing dysphagia and intermittent chest pain underwent a screening chest radiograph. Findings of a large mass prompted cross sectional imaging where extensive and marked diffuse esophageal thickening was demonstrated. The patient ultimately underwent biopsy and surgical resection for diffuse esophageal leiomyomatosis. Diffuse leiomyomatosis of the esophagus has been described in the literature for about 100 years with increasing recognition in more recent times. There is a known association with inherited syndromes such as Alport and Esophageal-Vulvar syndrome, though some cases are sporadic. This case report will demonstrate the imaging features of diffuse esophageal leiomyomatosis utilizing multiple modalities including radiography, fluoroscopy, CT, and MRI, with surgical and pathologic correlation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: A closed degloving injury is often referred to as a Morel-Lavellée lesion regardless of location despite traditionally being associated with the hip in adults. It results from a shearing injury that separates the subcutaneous layers from the fascia with fluid filling a potential space., Objective: While the most common location and cause have been described in adults, there is limited literature in pediatric patients. We have seen pediatric Morel-Lavellée lesions commonly occurring at the knee after sports. We set out to describe the magnetic resonance imaging (MRI) characteristics., Materials and Methods: A retrospective analysis was performed. All patients with trauma to the pelvis and lower extremities with a subcutaneous fluid collection seen on MRI were evaluated. Age, gender, mechanism of injury, time interval to imaging, and treatment were recorded. The collections were evaluated for location, size, shape and signal characteristics including the presence of fat, blood and septations., Results: Twenty-one patients ages 7 to 17 years old had findings of degloving injury on MRI. The most common etiology was sports related (18/21, 85.7%). The anterior knee was most often affected (18/21, 85.7%). Lesions were ovoid and centered over the medial retinaculum (8/18, 44.4%) or lateral retinaculum (7/18, 38.9%). A capsule was weakly associated with later presentation (P=0.12)., Conclusion: Pediatric Morel-Lavellée lesions commonly occur in a location not classically described, the anterior knee, and often after sports injury. Commonly, the collections are ovoid and always located at the subcutaneous fat/fascial interface. Recognition of specific imaging characteristics in a common location after sports injury allows for early identification. While most patients recover with conservative management, some need additional intervention with aspiration or debridement.

Background: Diffusion restriction has been utilized as a marker for bowel inflammation on magnetic resonance enterography (MRE). However, diffusion restriction has been seen in otherwise normal appearing small bowel in patients without active inflammation, with little published data on this subject., Objective: Assess diffusion restriction in normal loops of jejunum and to determine if there is a correlation to luminal distention, age, magnet field strength, slice thickness, and bowel segment location., Materials and Methods: A retrospective analysis of subjects with a normal MRE and clinical work-up was performed. The abdomen was divided into four quadrants. If available, two loops of jejunum were randomly chosen in each quadrant. Two radiologists evaluated the loops of jejunum for distension, wall thickness, enhancement and diffusion restriction. Disagreement was resolved by consensus. Presence of diffusion restriction was correlated with luminal distension, age, magnet field strength, slice thickness and abdominal quadrant., Results: One hundred ninety-seven loops of jejunum were evaluated in 39 subjects. Fifteen subjects (38.5%) had jejunal loops with diffusion restriction for a total of 28 loops. There was no correlation between diffusion restriction and luminal distension, age, magnet field strength or quadrant location (P>0.05, Pearson chi-squared test or Student's t-tests). Of the 15 subjects with a loop demonstrating diffusion restriction, additional loops with diffusion restriction were found in 40%. There was a very weak trend observed for greater slice thickness in patients with jejunal diffusion restriction (Student's t-test, P=0.10)., Conclusion: Jejunal diffusion restriction is a common finding in children with no clinical evidence of bowel pathology, irrespective of patient age, luminal distension, location of bowel loop and magnetic field strength. Further studies may be valuable in assessing the impact of slice thickness on subjective diffusion restriction in the jejunum.

Background: Children with Alagille syndrome undergo surveillance radiologic examinations as they are at risk for developing cirrhosis and hepatocellular carcinoma. There is limited literature on the imaging of liver masses in Alagille syndrome. We report the ultrasound (US) and magnetic resonance imaging (MRI) appearances of incidental benign giant hepatic regenerative nodules in this population., Objective: To describe the imaging findings of giant regenerative nodules in patients with Alagille syndrome., Materials and Methods: A retrospective search of the hospital database was performed to find all cases of hepatic masses in patients with Alagille syndrome during a 10-year period. Imaging, clinical charts, laboratory data and available pathology were reviewed and analyzed and summarized for each patient., Results: Twenty of 45 patients with confirmed Alagille syndrome had imaging studies. Of those, we identified six with giant focal liver masses. All six patients had large central hepatic masses that were remarkably similar on US and MRI, in addition to having features of cirrhosis. In each case, the mass was located in hepatic segment VIII and imaging showed the mass splaying the main portal venous branches at the hepatic hilum, as well as smaller portal and hepatic venous branches coursing through them. On MRI, signal intensity of the mass was isointense to liver on T1-weighted sequences in four of six patients, but hyperintense on T1 in two of six patients. In all six cases, the mass was hypointense on T2- weighted sequences. The mass post-contrast was isointense to adjacent liver in all phases in five the cases. Five out of six patients had pathological correlation demonstrating preserved ductal architecture confirming the final diagnosis of a regenerative nodule., Conclusion: Giant hepatic regenerative nodules with characteristic US and MR features can occur in patients with Alagille syndrome with underlying cirrhosis. Recognizing these lesions as benign giant hepatic regenerative nodules should, thereby, mitigate any need for intervention.

Swi1 and Swi3 form the replication fork protection complex and play critical roles in proper activation of the replication checkpoint and stabilization of replication forks in the fission yeast Schizosaccharomyces pombe. However, the mechanisms by which the Swi1-Swi3 complex regulates these processes are not well understood. Here, we report functional analyses of the Swi1-Swi3 complex in fission yeast. Swi1 possesses the DDT domain, a putative DNA binding domain found in a variety of chromatin remodeling factors. Consistently, the DDT domain-containing region of Swi1 interacts with DNA in vitro, and mutations in the DDT domain eliminate the association of Swi1 with chromatin in S. pombe cells. DDT domain mutations also render cells highly sensitive to S-phase stressing agents and induce strong accumulation of Rad22-DNA repair foci, indicating that the DDT domain is involved in the activity of the Swi1-Swi3 complex. Interestingly, DDT domain mutations also abolish Swi1's ability to interact with Swi3 in cells. Furthermore, we show that Swi1 is required for efficient chromatin association of Swi3 and that the Swi1 C-terminal domain directly interacts with Swi3. These results indicate that Swi1 associates with chromatin through its DDT domain and recruits Swi3 to function together as the replication fork protection complex.

Multiple genome maintenance processes are coordinated at the replication fork to preserve genomic integrity. How eukaryotic cells accomplish such a coordination is unknown. Swi1 and Swi3 form the replication fork protection complex and are involved in various processes including stabilization of replication forks, activation of the Cds1 checkpoint kinase and establishment of sister chromatid cohesion in fission yeast. However, the mechanisms by which the Swi1-Swi3 complex achieves and coordinates these tasks are not well understood. Here, we describe the identification of separation-of-function mutants of Swi3, aimed at dissecting the molecular pathways that require Swi1-Swi3. Unlike swi3 deletion mutants, the separation-of-function mutants were not sensitive to agents that stall replication forks. However, they were highly sensitive to camptothecin that induces replication fork breakage. In addition, these mutants were defective in replication fork regeneration and sister chromatid cohesion. Interestingly, unlike swi3-deleted cell, the separation-of-functions mutants were proficient in the activation of the replication checkpoint, but their fork regeneration defects were more severe than those of checkpoint mutants including cds1Δ, chk1Δ and rad3Δ. These results suggest that, while Swi3 mediates full activation of the replication checkpoint in response to stalled replication forks, Swi3 activates a checkpoint-independent pathway to facilitate recovery of collapsed replication forks and the establishment of sister chromatid cohesion. Thus, our separation-of-function alleles provide new insight into understanding the multiple roles of Swi1-Swi3 in fork protection during DNA replication, and into understanding how replication forks are maintained in response to different genotoxic agents.

Replication of chromosomes involves a variety of replication proteins including DNA polymerases, DNA helicases, and other accessory factors. Many of these proteins are known to localize at replication forks and travel with them as components of the replisome complex. Other proteins do not move with replication forks but still play an essential role in DNA replication. Therefore, in order to understand the mechanisms of DNA replication and its controls, it is important to examine localization of each replication factor. Here we describe a chromatin immunoprecipitation (ChIP) method to locate a replication factor at the replication fork. Defining the localization of replication proteins should provide important insight into mechanistic understanding of the regulation of the DNA replication process.

A sediment sample, impregnated with asphaltic petroleum and polymetallic sulfide, was dredged from the southern end of Gorda Ridge (the Escanaba Trough) off northern California, within the offshore Exclusive Economic Zone of the United States. The molecular distributions of hydrocarbons in this petroleum show that it was probably derived from terrestrial organic matter in turbidite sediment filling the Escanaba Trough. Hydrothermal activity at the Gorda Ridge spreading center provided the heat for petroleum formation and was the source of fluids for sulfide mineralization.