Imaging findings in acute pediatric coronavirus disease 2019 (COVID-19) pneumonia and multisystem inflammatory syndrome in children (MIS-C).

The two primary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children are acute coronavirus disease 2019 (COVID-19) pneumonia and multisystem inflammatory syndrome (MIS-C). While most pediatric cases of acute COVID-19 disease are mild or asymptomatic, some children are at risk for developing severe pneumonia. In MIS-C, children present a few weeks after SARS-CoV-2 exposure with a febrile illness that can rapidly progress to shock and multiorgan dysfunction. In both diseases, the clinical and laboratory findings can be nonspecific and present a diagnostic challenge. Thoracic imaging is commonly obtained to assist with initial workup, assessment of disease progression, and guidance of therapy. This paper reviews the radiologic findings of acute COVID-19 pneumonia and MIS-C, highlights the key distinctions between the entities, and summarizes our understanding of the role of imaging in managing SARS-CoV-2-related illness in children.

Appendiceal involvement in pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): a diagnostic challenge in the coronavirus disease (COVID) era.

BACKGROUND: Many studies on pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (PIMS-TS) have described abdominal findings as part of multisystem involvement, with limited descriptions of abdominal imaging findings specific to PIMS-TS. OBJECTIVE: To perform a detailed evaluation of abdominal imaging findings in children with PIMS-TS. MATERIALS AND METHODS: We performed a single-center retrospective study of children admitted to our institution between April 2020 and January 2021 who fulfilled Royal College of Paediatrics and Child Health criteria for PIMS-TS and who had cross-sectional abdominal imaging. We studied clinical data, abdominal imaging, laboratory markers, echocardiography findings, treatment and outcomes for these children. We also reviewed the literature on similar studies. RESULTS: During the study period, 60 PIMS-TS cases were admitted, of whom 23 required abdominal imaging. Most (74%) were from a Black, Asian or minority ethnic background and they had an average age of 7 years (range 2-14 years). All children had fever and gastrointestinal symptoms on presentation with elevated C-reactive protein, D-dimer and fibrinogen. Most had lymphopenia, raised ferritin and hypoalbuminemia, with positive severe acute respiratory syndrome coronavirus 2 immunoglobulin G antibodies in 65%. Free fluid (78%), right iliac fossa mesenteric inflammation (52%), and significantly enlarged mesenteric lymph nodes (52%) were the most common imaging findings. Appendiceal inflammation (30%) and abnormal distal ileum and cecum/ascending colon wall thickening (35%) were also common. All children responded well to medical management alone, with no mortality. CONCLUSION: In addition to free fluid, prominent lymphadenopathy, and inflammatory changes in the right iliac fossa, we found abnormal long-segment ileal thickening and appendicitis to be frequent findings. Recognition of appendiceal involvement as a component of the PIMS-TS spectrum should help clinicians avoid unnecessary surgical intervention as part of a multidisciplinary team approach.

Abdominal US in Pediatric Inflammatory Multisystem Syndrome Associated with SARS-CoV-2 (PIMS-TS).

Background Children with pediatric inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS), also known as multisystem inflammatory syndrome in children, present with abdominal pain among other nonspecific symptoms. Although initial imaging features of PIMS-TS have been reported, the duration of sonographic features remains unknown. Purpose To describe the abdominal US features of PIMS-TS at initial presentation and follow-up. Materials and Methods A retrospective review of children and young adults presenting with clinical features suspicious for PIMS-TS between April 2020 and June 2021 was carried out. US features were documented and reviewed at initial presentation and follow-up. Descriptive statistics were used and interobserver variability was calculated. Results Of 140 children and young adults presenting with suspected PIMS-TS, 120 had confirmed PIMS-TS (median age, 9 years; interquartile range, 7-12 years; 65 male patients) and 102 underwent abdominal US at presentation. PIMS-TS was present as a single abnormality in 109 of the 120 patients (91%) and abdominal symptoms were present in 104 of the 109 (95%). US examinations were abnormal in 86 of 102 patients (84%), with ascites being the most common abnormality in 65 (64%; 95% CI: 54, 73). Bowel wall thickening was present at US in 14 of the 102 patients (14%; 95% CI: 7, 20) and mesenteric inflammation was present in 16 (16%; 95% CI: 9, 23); all of these patients presented with abdominal symptoms. Among the patients with bowel wall thickening, the distal and terminal ileum were most involved (eight of 14 patients, 57%). Abdominal symptoms decreased to seven of 56 patients (13%) in those followed up at 6 months. Thirty-eight patients underwent follow-up US, and the presence of bowel inflammation had decreased to three of 27 patients (11%; 95% CI: -1, 23) in those followed up for less than 2 months and 0 of 17 (0%) in those followed up for more than 2 months. Conclusion Of 102 patients with pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 who underwent US at presentation, 14 (14%) had abdominal US findings of bowel inflammation and 16 (16%) had mesenteric edema. All US abnormalities resolved after 2 months. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by van Rijn and Pajkrt in this issue.

Multisystem inflammatory syndrome in children associated with SARS-CoV-2: extracardiac radiological findings.

OBJECTIVE: Multisystem inflammatory syndrome in children (MIS-C) is seen as a serious delayed complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The aim of this study was to describe the most common imaging features of MIS-C associated with SARS-CoV-2. METHODS: A retrospective review was made of the medical records and radiological imaging studies of 47 children (26 male, 21 female) in the age range of 25 months-15 years who were diagnosed with MIS-C between August 2020 and March 2021. Chest radiographs were available for all 47 patients, thorax ultrasound for 6, chest CT for 4, abdominal ultrasound for 42, abdomen CT for 9, neck ultrasound for 4, neck CT for 2, brain CT for 1, and brain MRI for 3. RESULTS: The most common finding on chest radiographs was perihilar-peribronchial thickening (46%). The most common findings on abdominal ultrasonography were mesenteric inflammation (42%), and hepatosplenomegaly (38%, 28%). Lymphadenopathy was determined in four patients who underwent neck ultrasound, one of whom had deep neck infection on CT. One patient had restricted diffusion and T2 hyperintensity involving the corpus callosum splenium on brain MRI, and one patient had epididymitis related with MIS-C. CONCLUSION: Pulmonary manifestations are uncommon in MIS-C. In the abdominal imaging, mesenteric inflammation, hepatosplenomegaly, periportal edema, ascites and bowel wall thickening are the most common findings. ADVANCES IN KNOWLEDGE: The imaging findings of MIS-C are non-specific and can mimic many other pathologies. Radiologists should be aware that these findings may indicate the correct diagnosis of MIS-C.

Midterm Outcomes and Cardiac Magnetic Resonance Imaging following Multisystem Inflammatory Syndrome in Children.

At midterm follow-up visits performed at a median of 7 months (IQR 6.0-8.4 months), 16 patients with multisystem inflammatory syndrome in children had resolution of left ventricular dysfunction and most had resolution of coronary aneurysms. On cardiovascular magnetic resonance imaging, no patients had late gadolinium enhancement.

Short-Term Outcomes After Multisystem Inflammatory Syndrome in Children Treatment.

This is a retrospective chart review of 20 patients treated with a consensus-driven treatment algorithm in multisystem inflammatory syndrome in children patients across a wide clinical spectrum. Their treatments and clinical status are described as well as their favorable return to functional baseline by 30 days post presentation.

Longitudinally extensive transverse myelitis as a sign of multisystem inflammatory syndrome following COVID-19 infection: A pediatric case report.

COVID-19 infection can cause inflammatory reactions that could involve several organs. In the pediatric population, Multi-System Inflammatory Syndrome in Children (MIS-C) has been reported as one of the consequences of COVID-19. We report a unique pediatric COVID-19 patient with MIS-C, associated with paralysis of the extremities. MRI showed abnormal signal in the cervical spinal cord compatible with transverse myelitis. Methylprednisolone and IVIG were administered, without significant symptom improvement. As a next step, Infliximab was tried for her, and she responded remarkably well to this treatment. Infliximab may be considered as a treatment option in COVID-19 patients with transverse myelitis.

Clinical and radiological findings for the new multisystem inflammatory syndrome in children associated with COVID-19.

The World Health Organization defines the multisystem inflammatory syndrome in children (MIS-C) as a new syndrome reported in patients aged <19 years old who have a history of exposure to SARS-CoV-2. The onset of this syndrome is characterized by persistent fever that is associated with lethargy, abdominal pain, vomiting and/or diarrhea, and, less frequently, rash and conjunctivitis. The course and severity of the signs and symptoms vary; in some children, MIS-C worsens rapidly and can lead to hypotension, cariogenic shock, or even damage to multiple organs. The characteristic laboratory findings are elevated markers of inflammation and heart dysfunction. The most common radiological findings are cardiomegaly, pleural effusion, signs of heart failure, ascites, and inflammatory changes in the right iliac fossa. In the context of the current COVID-19 pandemic, radiologists need to know the clinical, laboratory, and radiological characteristics of this syndrome to ensure the correct diagnosis.

Coronavirus disease 2019 (COVID-19): A systematic review of 133 Children that presented with Kawasaki-like multisystem inflammatory syndrome.

Kawasaki-like disease (KLD) and multisystem inflammatory syndrome in children (MIS-C) are considered as challenges for pediatric patients under the age of 18 infected with coronavirus disease 2019 (COVID-19). A systematic search was performed on July 2, 2020, and updated on December 1, 2020, to identify studies on KLD/MIS-C associated with COVID-19. The databases of Scopus, PubMed, Web of Science, Embase, and Scholar were searched. The hospitalized children with a presentation of Kawasaki disease (KD), KLD, MIS-C, or inflammatory shock syndromes were included. A total number of 133 children in 45 studies were reviewed. A total of 74 (55.6%) cases had been admitted to pediatric intensive care units (PICUs). Also, 49 (36.8%) patients had required respiratory support, of whom 31 (23.3%) cases had required mechanical ventilation/intubation, 18 (13.5%) cases had required other oxygen therapies. In total, 79 (59.4%) cases had been discharged from hospitals, 3 (2.2%) had been readmitted, 9 (6.7%) had been hospitalized at the time of the study, and 9 (6.7%) patients had expired due to the severe heart failure, shock, brain infarction. Similar outcomes had not been reported in other patients. Approximately two-thirds of the children with KLD associated with COVID-19 had been admitted to PICUs, around one-fourth of them had required mechanical ventilation/intubation, and even some of them had been required readmissions. Therefore, physicians are strongly recommended to monitor children that present with the characteristics of KD during the pandemic as they can be the dominant manifestations in children with COVID-19.

Acral Gangrene: Ugly Cousin of "COVID Toes" in Multisystem Inflammatory Syndrome in Children Associated with SARS-CoV-2?

A spectrum of dermatologic manifestations has been reported in multisystem inflammatory syndrome in children associated with SARS-CoV-2 infection. We report 2 patients with multisystem inflammatory syndrome in children and severe cardiovascular dysfunction who developed acral gangrene. Both responded well to therapy and recovered in the follow-up.

Point-of-Care Ultrasound Findings in Multisystem Inflammatory Syndrome in Children: A Cross-Sectional Study.

OBJECTIVES: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 is a novel pediatric condition with significant morbidity and mortality. The primary objective of this investigation was to describe the point-of-care ultrasound (POCUS) findings in patients evaluated in the emergency department (ED) who were diagnosed with MIS-C. METHODS: A retrospective cross-sectional study was conducted including patients <21-years-old who had POCUS performed for clinical care in a pediatric ED and were diagnosed with MIS-C. Point-of-care ultrasound studies were performed by pediatric emergency medicine attending physicians or fellows. Data abstracted by chart review included patient demographics, clinical history, physical examination findings, diagnostic test results, the time POCUS studies and echocardiograms were performed, therapies administered, and clinical course after admission. RESULTS: For the 24 patients included, 17 focused cardiac ultrasound, 9 lung POCUS, 7 pediatric modified rapid ultrasound for shock and hypotension, 1 focused assessment with sonography for trauma, 1 POCUS for suspected appendicitis, and 1 ocular POCUS were performed by 13 physicians. Point-of-care ultrasound identified impaired cardiac contractility in 5 patients, large intraperitoneal free fluid with inflamed bowel in 1 patient, and increased optic nerve sheath diameters with elevation of the optic discs in 1 patient. Trace or small pericardial effusions, pleural effusions, and intraperitoneal free fluid were seen in 3 patients, 6 patients, and 4 patients, respectively. CONCLUSIONS: This study demonstrates the spectrum of POCUS findings in MIS-C. Prospective studies are needed to help delineate the utility of incorporating POCUS into an ED management pathway for patients with suspected MIS-C.

Epidemiological features of coronavirus disease 2019 in children: a meta-analysis.

OBJECTIVE: Many studies have been published recently on the characteristics of the clinical manifestations of COVID-19 in children. The quality scores of literature are different, and the incidence of clinical manifestations and laboratory tests results vary greatly. Therefore, a systematic retrospective meta-analysis is needed to determine the incidence of the clinical manifestations of COVID-19 in children. MATERIALS AND METHODS: Data from databases, such as PubMed, Web of science, EMBASE, Johns Hopkins University, and Chinese databases were analysed from January 31, 2020 to October 20, 2020. High-quality articles were selected for analysis based on a quality standard score. A meta-analysis of random effects was used to determine the prevalence of comorbidities and subgroup meta-analysis to examine the changes in the estimated prevalence in different subgroups. RESULTS: Seventy-one articles involving 11,671 children were included in the study. The incidence of fever, respiratory symptoms, gastrointestinal symptoms, asymptomatic patients, nervous system symptoms, and chest tightness was 55.8%, 56.8%, 14.4%, 21.1%, 6.7%, and 6.1%, respectively. The incidence of multisystem inflammatory syndrome was 6.2%. Laboratory examination results showed that lymphocytes decreased in 12% and leukocytes decreased in 8.8% of patients, whereas white blood cells increased in 7.8% of patients. Imaging showed abnormalities in 66.5%, and ground-glass opacities were observed in 36.9% patients. Epidemiological history was present in 85.2% cases; severe disease rate was 3.33%. The mortality rate was 0.28%. CONCLUSIONS: The clinical symptoms of COVID-19 in children are mild, and laboratory indicators and imaging manifestations are atypical. While screening children for COVID-19, in addition to assessing patients for symptoms as the first step of screening, the epidemiological history of patients should be obtained.

Private Tour Guide to Pediatric Coronavirus Disease of 2019 and Multisystem Inflammatory Syndrome in Children in 10 Minutes: What Thoracic Radiologists Need to Know.

Filtering through the plethora of radiologic studies generated in response to the coronavirus disease of 2019 (COVID-19) pandemic can be time consuming and impractical for practicing thoracic radiologists with busy clinical schedules. To further complicate matters, several of the imaging findings in the pediatric patients differ from the adult population. This article is designed to highlight clinically useful information regarding the imaging manifestations of pediatric COVID-19 pneumonia, including findings more unique to pediatric patients, and multisystem inflammatory syndrome in children.

Spectrum of Imaging Findings at Chest Radiography, US, CT, and MRI in Multisystem Inflammatory Syndrome in Children Associated with COVID-19.

This case series examines the spectrum of imaging findings at chest radiography, US, CT, and MRI in 35 children admitted to a tertiary pediatric hospital in April and May 2020 with a post-coronavirus disease 2019 inflammatory condition known as multisystem inflammatory syndrome in children. The constellation of findings includes airway inflammation and rapid development of pulmonary edema on thoracic images, coronary artery aneurysms, and extensive right iliac fossa inflammatory changes on abdominal images. Awareness of this emerging condition and the expected multi-organ imaging findings will aid radiologists in the assessment of these complex cases.

Extracardiac imaging findings in COVID-19-associated multisystem inflammatory syndrome in children.

BACKGROUND: Coronavirus disease 2019 (COVID-19)-associated multisystem inflammatory syndrome in children (MIS-C) is an emerging syndrome that presents with a Kawasaki-like disease and multiorgan damage in children previously exposed to COVID-19. OBJECTIVE: To review the extracardiac radiologic findings of MIS-C in a group of children and young adults with a confirmed diagnosis of MIS-C. MATERIALS AND METHODS: In a retrospective study from April 1, 2020, to July 31, 2020, we reviewed the imaging studies of 47 children and adolescents diagnosed with MIS-C, 25 females (53%) and 22 males (47%), with an average age of 8.4 years (range 1.3-20 years). Forty-five had chest radiographs, 8 had abdominal radiographs, 13 had abdominal US or MRI, 2 had neck US, and 4 had brain MRI. RESULTS: Thirty-seven of 45 (82%) patients with chest radiographs had findings, with pulmonary opacities being the most common finding (n=27, 60%), most often bilateral and diffuse, followed by peribronchial thickening (n=26, 58%). Eight patients had normal chest radiographs. On abdominal imaging, small-volume ascites was the most common finding (n=7, 54%). Other findings included right lower quadrant bowel wall thickening (n=3, 23%), gallbladder wall thickening (n=3, 23%), and cervical (n=2) or abdominal (n=2) lymphadenopathy. Of the four patients with brain MRI, one had bilateral parieto-occipital abnormalities and another papilledema. CONCLUSION: The diagnosis of MIS-C and its distinction from other pathologies should be primarily based on clinical presentation and laboratory evidence of inflammation because imaging findings are nonspecific. However, it should be considered in the setting of bilateral diffuse pulmonary opacities, peribronchial thickening, right lower quadrant bowel inflammation or unexplained ascites in a child presenting with Kawasaki-like symptoms and a history of COVID-19 infection or recent COVID-19 exposure.

Chest radiograph features of multisystem inflammatory syndrome in children (MIS-C) compared to pediatric COVID-19.

BACKGROUND: Although the radiographic features of coronavirus disease 2019 (COVID-19) in children have been described, the distinguishing features of multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 are not well characterized. OBJECTIVE: We compared the chest radiographic findings of MIS-C with those of COVID-19 and described other distinguishing imaging features of MIS-C. MATERIALS AND METHODS: We performed a retrospective case series review of children ages 0 to 18 years who were hospitalized at Children's Healthcare of Atlanta from March to May 2020 and who either met the Centers for Disease Control and Prevention (CDC) case definition for MIS-C (n=11) or who had symptomatic, laboratory-confirmed COVID-19 (n=16). Two radiologists reviewed the most severe chest radiographs for each patient. The type and distribution of pulmonary opacities and presence or absence of pleural effusions were recorded. The chest radiographs were categorized based on potential COVID-19 imaging findings as typical, indeterminate, atypical or negative. An imaging severity score was also assigned using a simplified version of the Radiographic Assessment of Lung Edema Score. Findings were statistically compared between patients with MIS-C and those with COVID-19. Additional imaging findings of MIS-C were also described. RESULTS: Radiographic features of MIS-C included pleural effusions (82% [9/11]), pulmonary consolidations (73% [8/11]) and ground glass opacities (91% [10/11]). All of the lung opacities (100% [10/10]) were bilateral, and the majority of the pleural effusions (67% [6/9]) were bilateral. Compared to children with COVID-19, children with MIS-C were significantly more likely to develop pleural effusions on chest radiograph (82% [9/11] vs. 0% [0/0], P-value <0.01) and a lower zone predominance of pulmonary opacifications (100% [10/10] vs. 38% [5/13], P-value <0.01). Children with MIS-C who also had abdominal imaging had intra-abdominal inflammatory changes. CONCLUSION: Key chest radiographic features of MIS-C versus those of COVID-19 were pleural effusions and lower zone pulmonary opacifications as well as intra-abdominal inflammation. Elucidating the distinguishing radiographic features of MIS-C may help refine the case definition and expedite diagnosis and treatment.