Contrast-Enhanced Ultrasound of the Chest in Children and Adolescents: A Pilot Study for Assessment of Added Diagnostic Value.

OBJECTIVES: To determine the added diagnostic value of contrast-enhanced ultrasound (CEUS) in pediatric chest abnormalities by comparing interpretation of CEUS studies and confidence level to conventional US studies. METHODS: CEUS studies in patients with a variety of clinically suspected chest abnormalities performed between 2016 and 2020 were reviewed and compared to same-day conventional US studies. Examinations were independently interpreted by 4 radiologists blinded to clinical and other imaging data. Rater confidence was classified as low, moderate, or high. Diagnostic accuracy was determined by comparing image interpretation to patient outcome as the ground truth. Interobserver agreement was also assessed. RESULTS: Sixteen patients (10 male) with 18 CEUS studies were included. Median rater agreement with ground truth was significantly higher for CEUS (100%) than conventional US (50%; P = .004). Median rater confidence was high (3.0) for CEUS, and low-moderate (1.5) for conventional US (P < .001). CEUS sensitivity (54.6-81.8%) and specificity (63.4-100.0%) were greater than conventional US (45.5-72.7% and 12.5-63.5%, respectively). CEUS false positives (0-4) and false negatives (2-5) were fewer than conventional US (4-7 and 3-6, respectively). Except for one rater pair where agreement was substantial (κ = .78, P < .01), inter-rater agreement for CEUS for all other rater pairs was nonsignificant (κ = .25-0.51, P ≥ .07). Agreement for conventional US was moderate and statistically significant for 3 rater pairs (κ = .55-0.78) and nonsignificant for the remaining 3 rater pairs (P ≥ .06). CONCLUSIONS: CEUS adds diagnostic value to the assessment of a variety of chest abnormalities. The data support further evaluation of the role of CEUS as a non-invasive, problem-solving technique in children.

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.

Ultrasound-guided hydrostatic reduction of intussusception: comparison of success rates between subspecialized pediatric radiologists and non-pediatric radiologists or radiology residents.

Ileocolic intussusception is the most common cause of intestinal obstruction in children under two years of age. Treatment in most cases is radiologically guided reduction. In Slovenia, ultrasound (US)-guided hydrostatic reduction is currently the standard of care. The purpose of this study was to compare the success rate of US-guided hydrostatic reduction when performed by subspecialty-trained pediatric radiologists, non-pediatric radiologists, or radiology residents. We retrospectively analyzed medical records of patients with ileocolic intussusception who underwent US-guided hydrostatic intussusception reduction at University Medical Centre Ljubljana between January 2012 and December 2022 (n = 101). During regular daily working hours, the reduction was performed by pediatric radiologists. After hours (evenings and overnight), pediatric radiologists, non-pediatric radiologists, or radiology residents performed the reduction procedure. Patients were divided into three groups based on the operator performing the procedure. Data was analyzed using the chi-square test. Pediatric radiologists had thirty-seven (75.5%) successful first attempts, non-pediatric radiologists had nineteen (76.0%), and radiology residents had twenty (74.1%). There was no statistically significant difference in the success rate of ileocolic intussusception reduction depending on the operator who performed the procedure (p = 0.98). No perforation was observed in either group during the reduction attempts.  Conclusion: Our results demonstrate that US-guided hydrostatic reduction is a reliable and safe procedure that achieves good results even in the hands of less experienced, however appropriately trained, radiologists. The results should encourage more medical centers to consider the implementation of US-guided hydrostatic reduction of ileocolic intussusception. What is Known: • US-guided hydrostatic reduction is a well-established method of treatment for ileocolic intussusception in children. • The results regarding the influence of operator's experience with the procedure on its success rate are scarce and contradictory. What is New: • US-guided hydrostatic intussusception reduction is a reliable and safe technique that achieves similar success rates when performed by experienced subspecialized pediatric radiologists or less experienced but trained operators such as non-pediatric radiologists and radiology residents. • The implementation of US-guided hydrostatic reduction in general hospitals without subspecialized pediatric radiologists could improve patient care by increasing access to radiologically guided reduction and simultaneously decreasing the time to reduction attempts.

Computed tomography and magnetic resonance imaging for pulmonary embolus evaluation in children: up-to-date review on practical imaging protocols.

Pulmonary embolism (PE) is a potentially life-threatening condition that requires immediate medical intervention. Although PE was previously thought to occur infrequently in the pediatric population, recent studies have found a higher-than-expected prevalence of PE in the pediatric population of up to 15.5%. The imaging modality of choice for detecting PE in the pediatric population is multi-detector CT angiography, although MRI is assuming a growing and more important role as a potential alternative modality. Given the recent advances in both computed tomography pulmonary angiography (CTPA) and MRI techniques, a growing population of pediatric patients with complex comorbidities (such as children with a history of surgeries for congenital heart disease repair), and the recent waves of coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C), which are associated with increased risk of PE, there is new and increased need for an up-to-date review of practical CT and MRI protocols for PE evaluation in children. This article provides guidance for up-to-date CT and MR imaging techniques, reviews key recent studies on the imaging of pediatric PE, and discusses relevant pediatric PE imaging pearls and pitfalls, in hopes of providing readers with up-to-date and accurate practice for imaging evaluation of PE in children.

Tuberculosis revisted: classic imaging findings in childhood.

Tuberculosis (TB) remains one of the major public health threats worldwide, despite improved diagnostic and therapeutic methods. Tuberculosis is one of the main causes of infectious disease in the chest and is associated with substantial morbidity and mortality in paediatric populations, particularly in low- and middle-income countries. Due to the difficulty in obtaining microbiological confirmation of pulmonary TB in children, diagnosis often relies on a combination of clinical and radiological findings. The early diagnosis of central nervous system TB is challenging with presumptive diagnosis heavily reliant on imaging. Brain infection can present as a diffuse exudative basal leptomeningitis or as localised disease (tuberculoma, abscess, cerebritis). Spinal TB may present as radiculomyelitis, spinal tuberculoma or abscess or epidural phlegmon. Musculoskeletal manifestation accounts for 10% of extrapulmonary presentations but is easily overlooked with its insidious clinical course and non-specific imaging findings. Common musculoskeletal manifestations of TB include spondylitis, arthritis and osteomyelitis, while tenosynovitis and bursitis are less common. Abdominal TB presents with a triad of pain, fever and weight loss. Abdominal TB may occur in various forms, as tuberculous lymphadenopathy or peritoneal, gastrointestinal or visceral TB. Chest radiographs should be performed, as approximately 15% to 25% of children with abdominal TB have concomitant pulmonary infection. Urogenital TB is rare in children. This article will review the classic radiological findings in childhood TB in each of the major systems in order of clinical prevalence, namely chest, central nervous system, spine, musculoskeletal, abdomen and genitourinary system.

Lung and large airway imaging: magnetic resonance imaging versus computed tomography.

Disorders of the respiratory system are common in children and imaging plays an important role for initial diagnosis and follow-up evaluation. Radiographs are typically the first-line imaging test for respiratory symptoms in children and, when advanced imaging is required, CT has been the most frequently used imaging modality. However, because of increasing concern about potentially harmful effects of ionizing radiation on children, there has been a shift toward MRI in pediatric imaging. Although MRI of chest in children presents many technical challenges, recent advances in MRI technology are overcoming many of these issues, and MRI is now being used for evaluating the lung and large airway in children at centers with expertise in pediatric chest MRI. In this article we review the state of pediatric lung and large airway imaging, with an emphasis on cross-sectional modalities and the roles of MRI versus CT.

Pediatric large airway imaging: evolution and revolution.

Infants and children often present with respiratory symptoms referable to the airway. For these pediatric patients, airway imaging is frequently performed to evaluate for underlying disorders of the large airway. Various imaging modalities have been used to evaluate the pediatric large airway, and pediatric airway imaging techniques have continued to evolve. Therefore, clear understanding of the status and new advances in pediatric large airway imaging is essential for practicing radiologists to make timely and accurate diagnoses, which can lead to optimal pediatric patient management.

Imaging evaluation of the pediatric mediastinum: new International Thymic Malignancy Interest Group classification system for children.

Mediastinal masses are commonly identified in the pediatric population with cross-sectional imaging central to the diagnosis and management of these lesions. With greater anatomical definition afforded by cross-sectional imaging, classification of mediastinal masses into the traditional anterior, middle and posterior mediastinal compartments - as based on the lateral chest radiograph - has diminishing application. In recent years, the International Thymic Malignancy Interest Group (ITMIG) classification system of mediastinal masses, which is cross-sectionally based, has garnered acceptance by multiple thoracic societies and been applied in adults. Therefore, there is a need for pediatric radiologists to clearly understand the ITMIG classification system and how it applies to the pediatric population. The main purpose of this article is to provide an updated review of common pediatric mediastinal masses and mediastinal manifestations of systemic disease processes in the pediatric population based on the new ITMIG classification system.

Prospective Evaluation of Free-Breathing Fast T2-Weighted MultiVane XD Sequence at 3-T MRI for Large Airway Assessment in Pediatric Patients.

OBJECTIVE. The purpose of our study was to prospectively evaluate the technical feasibility of the free-breathing fast T2-weighted MultiVane XD sequence (sequence with non-Cartesian k-space filling using radial rectangular blades) at 3-T MRI for large airway assessment in pediatric patients. SUBJECTS AND METHODS. Forty consecutive pediatric patients (23 boys and 17 girls; age range, 5-15 years) referred for MRI examination for indications not related to neck, chest, or large airway disorders were enrolled in this prospective research study. All children underwent MRI in three planes using a free-breathing fast T2-weighted MultiVane XD sequence at 3-T MRI. The MR images were assessed by two pediatric radiologists independently for visualization of the large airways at six levels. The quality of the MR images was assessed and graded. Interobserver agreement between two radiologists was assessed using the kappa test, McNemar test, and intraclass correlation coefficients. RESULTS. High-quality MR images of the large airways were obtained in at least one plane in 38 MRI examinations (95.0%) by reviewer 1 and 37 MRI examinations (92.5%) by reviewer 2. Best-quality MR images with the least artifacts were seen in the sagittal plane followed by the coronal plane and the axial plane. The kappa test of agreement showed almost-perfect agreement between the two radiologists for MR image quality in the sagittal (κ = 1), coronal (κ = 0.96), and axial (κ = 0.81) planes. The McNemar test and intraclass correlation coefficients revealed similar results. CONCLUSION. The free-breathing fast T2-weighted MultiVane XD sequence at 3-T MRI is a technically feasible and promising new MRI technique for evaluating the large airways of pediatric patients in daily clinical practice.

Pediatric Lung MRI: Currently Available and Emerging Techniques.

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.

CT Features of Benign Intrapulmonary Lymph Nodes in Pediatric Patients With Known Extrapulmonary Solid Malignancy.

OBJECTIVE. The purpose of our study was to determine the CT features of benign intrapulmonary lymph nodes in pediatric patients with known extrapulmonary solid malignancy. MATERIALS AND METHODS. A retrospective review of surgical pathology archives was performed to identify consecutive chest CT studies of pediatric patients (≤ 18 years) with extrapulmonary solid malignancy and histologically confirmed benign intrapulmonary lymph nodes between January 1, 2004, and March 15, 2020. CT features of intrapulmonary lymph nodes-including size, shape, margin, type, associated calcification or fat, and location-were independently evaluated by two pediatric radiologist reviewers. The CT features of benign intrapulmonary lymph nodes in pediatric patients were analyzed using summary statistics. Interobserver agreement was measured with the kappa coefficient. RESULTS. There were 36 pathology-confirmed benign intrapulmonary lymph nodes in 27 pediatric patients (18 boys and nine girls; mean age, 12 years; age range, 1-18.2 years). Twenty-three (63.9%) of the benign intrapulmonary lymph nodes were biopsied from the right lung and 13 (36.1%) from the left lung (p = .03). The mean size, determined from CT studies, of benign intrapulmonary lymph nodes was 3.6 mm (SD, 1.4 mm; range, 1.3-7.8 mm). Triangular shape (25/36, 69.4%) was the most common shape of the benign intrapulmonary lymph nodes. Less commonly seen shapes of benign intrapulmonary lymph nodes were oval (6/36, 16.7%), round (3/36, 8.3%), and trapezoidal (2/36, 5.6%). All benign intrapulmonary lymph nodes were smoothly marginated and solid without associated calcification or fat. Of the 36 benign intrapulmonary lymph nodes, 15 (41.7%) were pleura-based; 11 (30.6%), perifissural; and 10 (27.8%), parenchymal. The kappa value for interobserver agreement between the two reviewers was 0.917 (95% CI, 0.825-1.000; standard error, 0.047), which corresponds to near-perfect agreement. CONCLUSION. In pediatric patients with known extrapulmonary solid malignancy, benign intrapulmonary lymph nodes are subcentimeter (mean size, 3.6 mm), smoothly marginated, and solid without containing calcification or fat on CT. In particular, triangular shape was the most commonly encountered shape of a benign intrapulmonary lymph node.

Imaging Findings in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated With Coronavirus Disease (COVID-19).

BACKGROUND. A multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease (COVID-19) has recently been described. OBJECTIVE. The purpose of our study was to evaluate the imaging findings of MIS-C associated with COVID-19. METHODS. Imaging studies and medical records of patients (age range, 0-20 years) admitted with MIS-C between April 22 and May 21, 2020, were retrospectively reviewed. Thoracic imaging studies were evaluated for parenchymal, mediastinal and hilar, and cardiovascular abnormalities. Abdominal imaging studies were evaluated for abnormalities of solid viscera, hollow viscera, and the peritoneum as well as the mesentery and retroperitoneum. Studies were reviewed independently by two radiologists, and disagreements were resolved by a third senior radiologist. RESULTS. Sixteen patients (10 male and six female patients; age range, 20 months-20 years) were included in this study. All 16 patients presented with fever. Other presenting signs and symptoms included the following: vomiting (12/16, 75%), abdominal pain (11/16, 69%), rash (10/16, 63%), conjunctivitis (8/16, 50%), diarrhea (7/16, 44%), headache (6/16, 38%), and sore throat (5/16, 31%). Shortness of breath and cough were each present in one patient. Chest radiography showed cardiomegaly (10/16, 63%), congestive heart failure or cardiogenic pulmonary edema (9/16, 56%), atelectasis (9/16, 56%), pleural effusions (7/16, 44%), acute respiratory distress syndrome (2/16, 13%), and pneumonia (1/16, 6%). Eight patients (50%) were evaluated for pulmonary embolism (PE) (six [75%] by CT angiography [CTA] and two [25%] by ventilation-perfusion scintigraphy). In two of the eight patients (25%), CTA showed a segmental PE. Abdominal imaging findings (ultrasound, CT, and radiography) included small-volume ascites (6/16, 38%), hepatomegaly (6/16, 38%), echogenic kidneys (5/16, 31%), bowel wall thickening (3/16, 19%), gallbladder wall thickening (3/16, 19%), mesenteric lymphadenopathy (2/16, 13%), splenomegaly (1/16, 6%), and bladder wall thickening (1/16, 6%). The frequencies of findings based on all the reviewed modalities were as follows: cardiomegaly (12/16, 75%), pleural effusion (10/16, 63%), and atelectasis (10/16, 63%). Absolute interobserver agreement was 0.69-1 for thoracic findings and 0.17-1 for abdominal findings. Fifteen patients (94%) were discharged from the hospital (length of hospital stay: range, 3-20 days), and one patient remained in the hospital at the end of the study period. There were no mortalities. CONCLUSION. MIS-C associated with COVID-19 is characterized predominantly by cardiovascular abnormalities, although solid visceral organ, gallbladder, and bowel abnormalities as well as ascites are also seen, reflecting a multisystemic inflammatory process. CLINICAL IMPACT. The constellation of imaging findings in the setting of COVID-19 may alert radiologists to the diagnosis of MIS-C before rapid deterioration of patients.

Pediatric Musculoskeletal Trauma: Upper Limb.

Pediatric upper extremity injuries, acute and chronic due to overuse, are commonly encountered in the clinical setting. However, interpretation of imaging studies is often challenging in pediatric patients because of changing postnatal skeletal development and the broad spectrum of pathology that can potentially occur. This article discusses normal skeletal development and the pathomechanics of skeletal injuries in pediatric patients. It also outlines a framework for imaging as it pertains to the pediatric upper extremity, with specific emphasis on acute and chronic injuries to the shoulder, elbow, forearm, and wrist.

Updates and Advances: Pediatric Musculoskeletal Infection Imaging Made Easier for Radiologists and Clinicians.

Infants and children often present with a wide range of musculoskeletal (MSK) infections in daily clinical practice. This can vary from relatively benign superficial infections such as cellulitis to destructive osseous and articular infections and life-threatening deep soft tissue processes such as necrotizing fasciitis. Imaging evaluation plays an essential role for initial detection and follow-up evaluation of pediatric MSK infections. Therefore, a clear and up-to-date knowledge of imaging manifestations in MSK infections in infants and children is imperative for timely and accurate diagnosis that, in turn, can result in optimal patient management. This article reviews an up-to-date practical imaging techniques, the differences between pediatric and adult MSK infections, the spectrum of pediatric MSK infections, and mimics of pediatric MSK infections encountered in daily clinical practice by radiologists and clinicians.

Pediatric Chest Radiographic and CT Findings of Electronic Cigarette or Vaping Product Use-associated Lung Injury (EVALI).

Background Electronic cigarette or vaping product use-associated lung injury (EVALI) is a serious public health concern with substantial morbidity and mortality, particularly in young individuals. Purpose To evaluate chest radiographic and chest CT findings of EVALI in the pediatric population. Materials and Methods This was a retrospective study of children who presented to a tertiary pediatric hospital from December 2018 to December 2019. Patients fulfilled the Centers for Disease Control and Prevention criteria for EVALI and had chest radiographs and CT images available at initial presentation. Two pediatric radiologists independently reviewed imaging for pattern, distribution, and extent of pulmonary abnormalities, as well as for extrapulmonary abnormalities. Clinical information, management, and outcomes were reviewed. Interobserver agreement was measured with Cohen κ coefficient. Results Seven male patients (50%) and seven female patients (50%) (mean age, 16 years; range, 13-18 years) were evaluated. All patients underwent chest radiography and CT within 4 days of presentation (range, 0-4 days). Chest radiographic findings included ground-glass opacity in 14 of 14 (100%) and consolidation in eight of 14 (57%). CT findings included ground-glass opacity in 14 of 14 (100%), consolidation in nine of 14 (64%), and interlobular septal thickening in two of 14 (14%). At CT, subpleural sparing was seen in 11 of 14 (79%) and a reversed halo sign was seen in five of 14 (36%). Chest radiographic and CT abnormalities were predominately bilateral in 14 of 14 (100%) and symmetric in 13 of 14 (93%), with lower lobe predominance in seven of 14 (50%). Extent of abnormality was predominately diffuse at both chest radiography and CT. There was almost perfect interobserver agreement between two reviewers for detecting abnormalities on chest radiographs (κ = 0.99; 95% confidence interval: 0.97, 1.00) and CT (κ = 0.99; 95% confidence interval: 0.98, 1.00). Conclusion In pediatric patients, electronic cigarette or vaping product use-associated lung injury is characterized by bilateral symmetric ground-glass opacities, consolidation, and a lower lobe predominance at CT. © RSNA, 2020.

Practical Imaging Strategies for Intussusception in Children.

OBJECTIVE. Intussusception is the most common cause of intestinal obstruction in young children. Radiology has a key role in its diagnosis and treatment. This systematic review summarizes the currently available evidence for best practices in radiologic management of pediatric intussusception. CONCLUSION. High diagnostic accuracy and lack of ionizing radiation make ultrasound (US) the preferred imaging modality for diagnosing intussusception. For intussusception reduction, fluoroscopy-guided pneumatic enema and US-guided hydrostatic enema are equally dependable and safe techniques. The areas that warrant further research in this field include the efficacy and safety of the US-guided pneumatic enema, potential benefits of sedation and general anesthesia for the reduction procedure, and the optimal management of intussusceptions potentially involving pathologic lead points.

Hepatobiliary MRI Contrast Agents: Pattern Recognition Approach to Pediatric Focal Hepatic Lesions.

OBJECTIVE. The purposes of this article are to review currently available hepatobiliary contrast agents, discuss techniques for optimization of pediatric liver MRI with hepatobiliary contrast agents, and review the imaging features of several pediatric hepatic lesions, focusing on their assessment with hepatobiliary contrast agents. CONCLUSION. MRI is the preferred imaging modality for complete assessment of focal liver lesions in the pediatric population. Imaging with gadolinium-based hepatobiliary contrast agents yields beneficial information about many focal liver lesions encountered in pediatric patients.

Pediatric Tongue Lesions: An Often-Overlooked but Important Collection of Diagnoses.

OBJECTIVE. The purpose of this article is to discuss imaging techniques and provide a pictorial review of pediatric tongue lesions. CONCLUSION. Pediatric tongue lesions represent an often-overlooked collection of abnormalities with a variety of clinical and radiologic features. The location of these lesions places the patient at risk for airway compromise. Systematic imaging evaluation of pediatric tongue lesions can help the radiologist arrive at a correct and timely diagnosis, thus improving and expediting patient care.

Pediatric SARS, H1N1, MERS, EVALI, and Now Coronavirus Disease (COVID-19) Pneumonia: What Radiologists Need to Know.

OBJECTIVE. The purpose of this article is to review new pediatric lung disorders-including disorders that have occurred in recent years years such as severe acute respiratory syndrome (SARS), swine-origin influenza A (H1N1), Middle East respiratory syndrome (MERS), e-cigarette or vaping product use-associated lung injury (EVALI), and coronavirus disease (COVID-19) pneumonia-to enhance understanding of the characteristic imaging findings. CONCLUSION. Although the clinical symptoms of SARS, H1N1, MERS, EVALI, and COVID-19 pneumonia in pediatric patients may be nonspecific, some characteristic imaging findings have emerged or are currently emerging. It is essential for radiologists to have a clear understanding of the characteristic imaging appearances of these lung disorders in pediatric patients to ensure optimal patient care.

Newly Developed Methods for Reducing Motion Artifacts in Pediatric Abdominal MRI: Tips and Pearls.

OBJECTIVE. The purpose of this article is to review established and emerging methods for reducing motion artifacts in pediatric abdominal MRI. CONCLUSION. Clearly understanding the strengths and limitations of motion reduction methods can enable practitioners of pediatric abdominal MRI to select and combine the appropriate techniques and potentially reduce the need for sedation and anesthesia.