How we do it: Cardiac implantable devices are not a contraindication to MRI: time for a paradigm shift.

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.

Development and clinical feasibility of a reduced-dose radiograph in children for feeding tube placement.

BACKGROUND: Temporary feeding tubes are commonly used but may lead to complications if malpositioned. Radiographs are the gold standard for assessing tube position, but clinician concern over radiation risks may curtail their use. OBJECTIVE: We describe development and use of a reduced dose feeding tube radiograph (RDFTR) targeted for evaluation of feeding tube position. MATERIALS AND METHODS: Age-based abdominal radiograph was adapted to use the lowest mAs setting of 0.32 mAs with field of view between carina and iliac crests. The protocol was tested in DIGI-13 line-pair plates and anthropomorphic phantoms. Retrospective review of initial clinical use compared dose area product (DAP) for RDFTR and routine abdomen, chest, or infant chest and abdomen. Review of RDFTR reports assessed tube visibility, malpositioning, and incidental critical findings. RESULTS: Testing through a line-pair phantom showed loss of spatial resolution from 2.2 line pairs to 0.6 line pairs but preserved visibility of feeding tube tip in RDFTR protocol. DAP comparisons across 23,789 exams showed RDFTR reduced median DAP 72-93% compared to abdomen, 55-78% compared to chest, and 76-79% compared to infant chest and abdomen (p<0.001). Review of 3286 reports showed tube was visible in 3256 (99.1%), malpositioned in airway 8 times (0.2%) and in the esophagus 74 times (2.3%). The tip was not visualized in 30 (0.9%). Pneumothorax or pneumoperitoneum was noted seven times (0.2%) but was expected or spurious in five of these cases. CONCLUSION: RDFTR significantly reduces radiation dose in children with temporary feeding tubes while maintaining visibility of tube tip.

Cardiac and Pericardial Neoplasms in Children: Radiologic-Pathologic Correlation.

Primary cardiac and pericardial neoplasms are rare in the pediatric population and can include both benign and malignant lesions. Rhabdomyomas, teratomas, fibromas, and hemangiomas are the most common benign tumors. The most common primary cardiac malignancies are soft-tissue sarcomas, including undifferentiated sarcomas, rhabdomyosarcomas, and fibrosarcomas. However, metastatic lesions are more common than primary cardiac neoplasms. Children with primary cardiac and pericardial tumors may present with nonspecific cardiovascular symptoms, and their clinical presentation may mimic that of more common nonneoplastic cardiac disease. The diagnosis of cardiac tumors has recently been facilitated using noninvasive cardiac imaging. Echocardiography is generally the first-line modality for evaluation. Cardiac MRI and CT are used for tissue characterization and evaluation of tumor size, extension, and physiologic effect. The varied imaging appearances of primary cardiac neoplasms can be explained by their underlying abnormality. Treatment of these lesions varies from conservative management, with spontaneous regression of some lesions such as rhabdomyomas, to surgical resection, particularly in patients with associated heart failure. With adequate imaging techniques and knowledge of the pathologic basis of the neoplasm, it is often possible to differentiate benign from malignant tumors, which can greatly affect adequate and timely treatment. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Yield of Postmortem Skeletal Surveys in Infants Presenting to Emergency Care With Sudden and Unexpected Death.

OBJECTIVES: Child abuse should be considered in cases of sudden unexpected infant death (SUID). Postmortem skeletal surveys (PM-SS) are recommended to evaluate for abusive fractures in SUID. Little is known about the yield of PM-SS among infants presenting to emergency care with SUID. Our objectives were to (1) describe the presentation and care of infants with SUID at a tertiary children's hospital emergency department and (2) report PM-SS use and findings. METHODS: We performed a retrospective study of infants younger than 12 months with SUID presenting to an urban emergency department from 2007 to 2019. We describe their presentation and care, including PM-SS performance and findings, referrals to the medical examiner, and reports to child protective services (CPS). We assessed for associations between race, payer, and presentation with reports to CPS. RESULTS: Of 73 infants with SUID, concern for unsafe sleep was documented in 45 (61.6%) and 71 (97.3%) underwent cardiopulmonary resuscitation by a medical professional. All 73 (100%) underwent PM-SS and were referred to the medical examiner. Twelve definite fractures (11 rib, 1 classic metaphyseal lesion) and 8 possible fractures (7 rib, 1 classic metaphyseal lesion) were identified among 6 (8.2%) infants. Forty-three (58.9%) were reported to CPS. There were no associations between race, payer, age, or history of unsafe sleep and CPS reports. CONCLUSIONS: One in 12 cases of SUID had a possible and/or definite fracture identified on plain radiography. Multicenter studies are needed to compare yield across different postmortem imaging modalities and populations.

Dual-source computed tomography protocols for the pediatric chest - scan optimization techniques.

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.

Persistent Left Superior Vena Cava and Inferior Vena Cava Dual Drainage to Coronary Sinus: A Case Report.

Dilation of the coronary sinus is often a result of excessive volume overload from congenital anomalies of systemic venous return to the heart. These abnormalities are often discovered incidentally later in life when a patient requires cardiac imaging, cardiac catheterization, or thoracic surgery. The most common abnormality is a persistent left superior vena cava. Inferior vena cava malformation is less common, yet several different anomalies can arise. The presence of persistent left superior vena cava or inferior vena cava anomalies requires further evaluation to rule out congenital heart disease in infants. Knowledge of technically challenging systemic venous anatomy is beneficial prior to procedures necessitating central venous access such as a central line, cardiac catheterization, and intracardiac device implantation. We present an unusual case of persistent LSVC and IVC both draining directly into a severely dilated coronary sinus that was diagnosed by fetal echocardiogram and later confirmed postnatally by transthoracic echocardiogram and computed tomography angiography. To our knowledge this is the second reported case of IVC drainage into the CS and the first case that reports this as a prenatal diagnosis.

Results of a Virtual Multi-Institutional Program for Quality Improvement Training and Project Facilitation.

OBJECTIVE: The purpose of this project was to describe the results of a multi-institutional quality improvement (QI) program conducted in a virtual format. METHODS: Developed at Stanford in 2016, the Realizing Improvement Through Team Empowerment program uses a team-based, project-based improvement approach to QI. The program was planned to be replicated at two other institutions through respective on-site programs but was converted to a multi-institutional virtual format in 2020 in response to the COVID-19 pandemic. The virtual program began in July 2020 and ended in December 2020. The two institutions participated jointly in the cohort, with 10 2-hour training sessions every 2 weeks for a total of 18 weeks. Project progress was monitored using a predetermined project progress scale by the program manager, who provided more direct project support as needed. RESULTS: The cohort consisted of six teams (37 participants) from two institutions. Each team completed a QI project in subjects including MRI, ultrasound, CT, diagnostic radiography, and ACR certification. All projects reached levels of between 3.0 (initial test cycles begun with evidence of modest improvement) and 4.0 (performance data meeting goal and statistical process control criteria for improvement) and met graduation criteria for program completion. DISCUSSION: We found the structured problem-solving method, along with timely focused QI education materials via a virtual platform, to be effective in simultaneously facilitating improvement projects from multiple institutions. The combination of two institutions fostered encouragement and shared learning across institutions.

Lymphatic anomalies in congenital heart disease.

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.

Spectral imaging in the pediatric chest: past, present and future.

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.

Determination of Contrast Timing by Time-Resolved Magnetic Resonance Angiography in Patients With Bidirectional Glenn and Hemi-Fontan Anastomoses.

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_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_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_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_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.

Magnetic resonance lymphangiography in post-Fontan palliation patients with MR non-conditional cardiac electronic devices: An institutional experience.

Magnetic resonance imaging (MRI) is a routinely used imaging modality for the diagnosis and treatment planning of many health conditions in children and adults. Yet, its use has been limited in many institutions for patients with cardiac implantable electronic devices (CIEDs) due to safety concerns. Current evidence relates primarily to devices with transvenous leads. However, patients with complex cardiac anatomy and palliative surgery procedures often require epicardial pacemakers. To date, very few studies have addressed MRI safety considerations with non-conditional CIEDs or abandoned epicardial leads in infants, and to our knowledge, this is the first report that shows Fontan palliation patients who underwent Dynamic Contrast enhanced MR Lymphangiography (DCMRL) with these types of devices. We present our institutional experience with five cases where a DCMRL was safely performed in three children and two adults with Fontan palliation to evaluate their lymphatic anatomy and guide interventional procedures. Regarding our brief experience, we concluded that DCMRL may be considered in post-Fontan patients with non-conditional CIEDs, including epicardial leads, seeking the best diagnostic and treatment options available. Institutional protocols must be revised in advance to perform this technique in a controlled setting.

Dynamic contrast-enhanced MR lymphangiography: feasibility of using ferumoxytol in patients with chronic kidney disease.

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.

Computed tomography of the airways and lungs in congenital heart disease.

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.

Optimizing neonatal cardiac imaging (magnetic resonance/computed tomography).

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.

Establishing a magnetic resonance safety program.

Establishing a magnetic resonance (MR) safety program is crucial to ensuring the safe MR imaging of pediatric patients. The organizational structure includes a core safety council and broader safety committee comprising all key stakeholders. These groups work in synchrony to establish a strong culture of safety; create and maintain policies and procedures; implement device regulations for entry into the MR setting; construct MR safety zones; address intraoperative MR concerns; guarantee safe scanning parameters, including complying with specific absorption rate limitations; adhere to national regulatory body guidelines; and ensure appropriate communication among all parties in the MR environment. Perspectives on the duties of the safety council members provide important insight into the organization of program oversite. Ultimately, the collective dedication and vigilance of all MR staff are crucial to the success of a safety program.

Normal age-related quantitative CT values in the pediatric lung: from the first breath to adulthood.

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.

Pediatric Cardiac CT and MRI: Considerations for the General Radiologist.

OBJECTIVE. This article reviews the use and current imaging techniques of cardiac CT angiography and cardiac MRI in the evaluation of commonly encountered pediatric cardiac processes that may present to the general radiologist. CONCLUSION. Imaging pediatric patients with acquired and congenital heart disease is an important skill for general radiologists. As survival rates increase and these patients enter adulthood, knowledge of pediatric acquired and congenital heart disease remains pertinent.

Characterization of Disease Phenotype in Very Preterm Infants with Severe Bronchopulmonary Dysplasia.

Rationale: Bronchopulmonary dysplasia (BPD) is a heterogenous condition with poorly characterized disease subgroups.Objectives: To define the frequency of three disease components: moderate-severe parenchymal disease, pulmonary hypertension (PH), or large airway disease, in a referral cohort of preterm infants with severe BPD. The association between each component and a primary composite outcome of death before hospital discharge, tracheostomy, or home pulmonary vasodilator therapy was assessed.Methods: This was a retrospective, single-center cohort study of infants born at <32 weeks' gestation with severe BPD who underwent both chest computed tomography with angiography (CTA) and echocardiography between 40 and 50 weeks postmenstrual age between 2011 and 2015. Moderate-severe parenchymal lung disease was defined as an Ochiai score ≥8 on CTA. PH was diagnosed by echocardiogram using standard criteria. Large airway disease was defined as tracheomalacia or bronchomalacia on bronchoscopy and/or tracheoscopy or CTA.Measurements and Main Results: Of 76 evaluated infants, 73 (96%) were classifiable into phenotypic subgroups: 57 with moderate-severe parenchymal disease, 48 with PH, and 44 with large airway disease. The presence of all three disease components was most common (n = 23). Individually, PH and large airway disease, but not moderate-severe parenchymal disease, were associated with increased risk for the primary study outcome. Having more disease components was associated with an incremental increase in the risk for the primary outcome (2 vs. 1: odds ratio, 4.9; 95% confidence interval, 1.4-17.2 and 3 vs. 1: odds ratio, 12.8; 95% confidence interval, 2.4-70.0).Conclusions: Infants with severe BPD are variable in their predominant pathophysiology. Disease phenotyping may enable better risk stratification and targeted therapeutic intervention.

Gender Differences Among Academic Pediatric Radiology Faculty in the United States and Canada.

OBJECTIVE: It is currently unknown whether efforts in recent years to create equal opportunities for female faculty in academic medicine have succeeded. We looked at faculty members in academic pediatric radiology departments across the United States and Canada to assess for evidence of gender disparities and differences in academic performance between males and females. METHODS: The analysis included diagnostic radiology programs across the United States and Canada, as specified by the American Medical Association's Fellowship and Residency Electronic Interactive Database (FREIDA Online) and the Canadian Resident Matching Service website. The Scopus database was used to retrieve the H-index, number of publications, and number of citations for each faculty member. We examined the distribution of male and female faculty members across geographical regions, academic ranks, and leadership roles. Academic performance was also compared. RESULTS: Across all regions and academic ranks, disparities exist between the number of male and female faculty members. The greatest disparity was found amongst the professor rank, where more than 70% of positions were occupied by males. Female professors were found to demonstrate similar levels of academic performance compared to their male counterparts, although this parity was not observed amongst assistant and associate professors. CONCLUSION: Women occupied almost half (46.6%) of the total academic pediatric radiology workforce, despite having been previously shown to make up only 21% of radiologists. However, gender disparities currently exist among academic pediatric radiology faculty, with a significantly higher percentage of men in pediatric radiology faculty positions. Women, however, currently occupy a greater percentage of leadership positions compared to men, even though the majority of senior academic ranks are held by men.

Diagnostic performance of CT angiography to detect pulmonary vein stenosis in children.

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.