Ectopic cervical thymus: Recognising the characteristic 'embroidery yarn' appearance on ultrasound.

Introduction: The thymus normally forms in the neck from the third pharyngeal pouch and descends to its normal position in the mediastinum. Arrest of descent or sequestration of thymic tissue can occur at any point along its path leading to an ectopic thymus which can present as a neck mass, usually in the paediatric age group. Purpose and Case Report: Ultrasound is generally performed in the presence of a neck mass in children. Although a characteristic 'starry sky' appearance of the thymus has been described on ultrasound, it is not considered sufficiently specific and cross-sectional imaging with magnetic resonance imaging is usually performed. On magnetic resonance imaging, the ectopic thymus appears as a homogeneous T1 isointense and T2 hyperintense mass and may actually appear ominous due to the tendency of ectopic thymus to sometimes show diffusion restriction unlike the normal thymus. Subsequent invasive biopsy or surgical removal is usually necessary to rule out a neoplastic lesion. In our observation, the ultrasound appearance of thymus is sufficiently distinctive to be confidently diagnosed as ectopic thymic tissue. This appearance is similar to the high-resolution appearance of an embroidery yarn. The reason most radiologists are not aware of the same is because the normal mediastinal thymus is not usually imaged by ultrasound. Conclusion: An accurate diagnosis on ultrasound would mean avoidance of expensive cross-sectional imaging and invasive biopsy or surgical excision in favour of regular non-invasive follow-up ultrasound scans until the lesion involutes in late childhood.

Birth-related subdural hemorrhage in asymptomatic neonates: evolution over time and differentiation from traumatic subdural hemorrhage.

BACKGROUND: Intracranial birth-related subdural hemorrhage frequently occurs in asymptomatic newborns and has no adverse long-term sequelae. It is medically and medicolegally important to differentiate birth-related subdural hemorrhage from other pathological causes of intracranial hemorrhage. There is limited literature available on the incidence of birth-related subdural hemorrhage, its imaging features, and evolution over time, mainly because asymptomatic infants do not routinely undergo cranial MRI. OBJECTIVE: To establish the incidence and distribution of birth-related subdural hemorrhage and evaluate their association with various modes of delivery, identify associated features, and evaluate the sequential evolution of signal changes of the birth-related hemorrhages on MRI. MATERIALS AND METHODS: A total of 200 healthy term neonates and young infants were included in this retrospective review study. All infants underwent MRI of the brain and cervical spine at postnatal age of 0-2 months with acquisition of a 3D T1-weighted (T1W), 3D or 2D T2-weighted (T2W), and axial diffusion-weighted imaging (DWI) sequences. The scans were evaluated for the presence and distribution of subdural hemorrhages, other intracranial hemorrhages, and associated injuries. Prevalence of intracranial hemorrhage in various modes of delivery was analyzed. Relationship between the signal intensities of the bleeds on T1W, T2W, and DWI scans and the age of the infants was analyzed. Appropriate tests were applied to test for statistical significance of the data. RESULTS: Out of 200 neonates, 66 (33%) had detectable intracranial hemorrhage on MRI with an age range of 11-25 days, including 31 (47%) males and 35 (53%) females. All of them had subdural hemorrhages, 54 (81.8%) of which were in the posterior fossa. Additional parenchymal hemorrhages were present in a few, but no subarachnoid hemorrhages, cervical spinal canal hemorrhages, cortical bridging vein injury, or cervical spinal ligamentous injury were identified within the limitations of the study. No detectable intracranial hemorrhage was found in subjects above 25 days of age. Overall incidence of subdural hemorrhage by mode of delivery was 8/68 (11.8%) in babies born by cesarean section and 58/132 (43.9%) in babies born by vaginal delivery. Among the vaginal deliveries, the highest incidence was observed in assisted vaginal delivery (19/30, 63.3%). Subjects with birth-related subdural hemorrhage were categorized into three age groups: <13 days, 13-21 days, and >21 days. All detected hemorrhages were T1W hyperintense. In the <13 days group, all bleeds were T2W hypointense. In the 13-21 days group, 73.1% were T2W hypointense, while 26.9% were T2W mixed. All bleeds in the >21 days group were T2W hypointense. All DWI hyperintense bleeds were found in the 13-21 days group. CONCLUSION: Birth-related subdural hemorrhage occurs in over a third of normal deliveries and has a characteristic distribution, predominantly in the posterior fossa. Associated cervical spinal subdural hemorrhages, cervical spinal ligamentous injury, or cortical bridging vein injury, which are concerning for traumatic etiology, were not identified. Birth-related subdural hemorrhages follow a characteristic pattern of signal changes on MRI. Although not completely reliable, this can help in differentiating them from traumatic intracranial hemorrhages which usually occur postnatally. No birth-related subdural hemorrhages were seen after 25 days of age in our cohort.

Collapse or distention of the perioptic space in children - What does it mean to pediatric radiologists? Comprehensive review of perioptic space evaluation.

The perioptic space comprises the subarachnoid space [SAS] of the optic nerve communicating with the SAS of the central nervous system. Pressure variations in the SAS of the central nervous system can be transmitted to the optic papilla through the perioptic space. Variations in the diameter of the perioptic space serve as an important indicator for select intracranial pathologies in the pediatric population. Though the perioptic space can be evaluated using various imaging modalities, MRI is considered highly effective due to its superior soft tissue resolution. With advancement in MR imaging techniques, high-resolution images of the orbits can provide improved visualization of the perioptic space. It is imperative for the pediatric radiologist to routinely assess the perioptic space on brain and orbit MR imaging, as it can prompt exploration for additional features associated with select intracranial pathologies, thus improving diagnostic accuracy. This article reviews basic anatomy of the perioptic space, current understanding of the CSF dynamics between the perioptic space and central nervous system SAS, various imaging modalities utilized in the assessment of the perioptic space, MRI sequences and the optimal parameters of specific sequences, normal appearance of the perioptic space on MR imaging, and various common pediatric pathologies which cause alteration in the perioptic space.

Clinical and radiological evaluation of caudal regression syndrome.

Caudal regression syndrome is a form of segmental spinal dysgenesis involving the caudal spinal column, ranging from segmental coccygeal agenesis to extensive thoracolumbar agenesis with varying degrees of spinal cord dysgenesis. A majority of caudal regression cases are sporadic but maternal pre-gestational diabetes mellitus is an important risk factor. Imaging is an integral part of management of caudal regression syndrome. Antenatal diagnosis on obstetric ultrasound and evaluation with fetal MRI is ideal. Early postnatal diagnosis and/or detailed evaluation with MRI is essential for early management to improve outcomes. Pang classification categorizes caudal regression syndrome into two categories based on the position of the conus while Renshaw classification is based on the degree of vertebral column agenesis. Caudal regression syndrome may be associated with several additional anomalies, both spinal and extraspinal. A number of genitourinary and gastrointestinal anomalies have been described in association with caudal regression syndrome. The field of view of MRI of the lumbosacral spine in caudal regression syndrome needs to be extended to visualize the retroperitoneal structures without the use of a saturation band. Syndromic associations may be suspected, and additional imaging performed, based on findings of extended field of view MRI of the spine. Associated sacral masses and filar abnormalities need to be identified and may also require surgical treatment. The multisystem nature of this disease necessitates a multimodality approach to the evaluation and management of caudal regression syndrome with close cooperation between pediatric neuroradiologists and body radiologists as well as multiple clinical teams. Appropriate early management with surgical correction as necessary can significantly improve prognosis and survival in caudal regression syndrome.

Arachnoid cyst in the pediatric patient: What the radiologist needs to know.

Arachnoid cysts are the most common incidentally discovered intracranial lesions on imaging and the most common cystic intracranial lesions. They may be developmental or secondary. A relative lack of recent literature and any comprehensive radiological review on arachnoid cysts has led to a general lack of awareness among radiologists of symptomatic or complicated arachnoid cysts. This is particularly concerning in pediatric patients. While arachnoid cysts are asymptomatic in most cases, they can cause clinical symptoms in a minority of cases, especially when they occur in unusual sites. These include intraventricular locations where they may cause hydrocephalus, the basal cisterns where they may compress cranial nerves, the cerebellopontine angle where they have to be differentiated from a number of cystic lesions, the cavum septum pellucidum or cavum velum interpositum, the choroid fissure where they can entrap the temporal horn and compress the hippocampus, the posterior fossa where they need to be differentiated from other posterior fossa cystic lesions, and within the spinal canal where there is a concern for cord or nerve root compression. Larger cysts are more prone to complications such as mass effect, hemorrhage, and rupture. Hemorrhage and rupture often present with acute symptoms. Ruptured cysts lose their characteristic imaging appearance and can mimic several ominous pathologies. It therefore becomes vital to accurately diagnose these cases as complications of pre-existing arachnoid cysts for appropriate management. A detailed review of all diagnostic imaging aspects of arachnoid cysts will help fill in the existing information void on this important entity.

Neonatal osteoblastic tumor with a novel PTBP1::FOSB fusion.

Congenital/neonatal bone neoplasms are extremely rare. We present the case of a patient with a neonatal bone tumor of the fibula that had osteoblastic differentiation and a novel PTBP1::FOSB fusion. FOSB fusions are described in several different tumor types, including osteoid osteoma and osteoblastoma; however, these tumors typically present in the second or third decade of life, with case reports as young as 4 months of age. Our case expands the spectrum of congenital/neonatal bone lesions. The initial radiologic, histologic, and molecular findings supported the decision for close clinical follow-up rather than more aggressive intervention. Since the time of diagnosis, this tumor has undergone radiologic regression without treatment.

Utility of balanced steady-state field precession sequence in the evaluation of retinal and subdural hemorrhages in patients with abusive head trauma.

Abusive head trauma is the leading cause of physical child abuse deaths in children under 5 years of age in the United States. To evaluate suspected child abuse, radiologic studies are typically the first to identify hallmark findings of abusive head trauma including intracranial hemorrhage, cerebral edema, and ischemic injury. Prompt evaluation and diagnosis are necessary as findings may change rapidly. Current imaging recommendations include brain magnetic resonance imaging with the addition of a susceptibility weighted imaging (SWI) sequence which can detect additional findings that suggest abusive head trauma including cortical venous injury and retinal hemorrhages. However, SWI is limited due to blooming artifacts and artifacts from the adjacent skull vault or retroorbital fat, which can affect the evaluation of retinal, subdural, and subarachnoid hemorrhages. This work explores the utility of the high-resolution, heavily T2 weighted balanced steady-state field precession (bSSFP) sequence to identify and characterize retinal hemorrhage and cerebral cortical venous injury in children with abusive head trauma. The bSSFP sequence provides distinct anatomical images to improve the identification of retinal hemorrhage and cortical venous injury.

Can you see with CT? Is cervical spine computed tomographic imaging sufficient in pediatric trauma?

BACKGROUND: Traumatic cervical spine injury (CSI) is fundamentally different in children, and imaging recommendations vary; however, prompt diagnosis is necessary. METHODS: We conducted a retrospective cohort study, evaluating children who presented after traumatic injury from 7/1/2012 to 12/31/2019 receiving a cervical spine CT. Evaluation of the incidence and clinical significance of CSI undetected on CT subsequently diagnosed on MRI was conducted. Additionally, all with CSI underwent image review to evaluate for potential overlooked, but visible pathology. RESULTS: 1487 children underwent a cervical spine CT, revealing 52 with CSI. 237 underwent MRI due to an abnormal CT or continued clinical concern. Ultimately, three were discovered to have clinically significant CSI missed on CT. In all cases, retrospective review demonstrated a retroclival hematoma when soft tissue windows were formatted in sagittal and coronal views. CONCLUSIONS: A normal CT may be sufficient to rule-out clinically significant CSI. However, the presence of a retroclival hematoma must be evaluated.

Imaging of pediatric calvarial and skull base tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper.

A standardized imaging protocol for pediatric oncology patients is essential for accurate and efficient imaging, while simultaneously promoting collaborative understanding of pathologies and radiologic assessment of treatment response. The objective of this article is to provide standardized pediatric imaging guidelines and parameters for evaluation of tumors of the pediatric orbit, calvarium, skull base, and temporal bone. This article was drafted based on current scientific literature as well as consensus opinions of imaging experts in collaboration with the Children's Oncology Group Diagnostic Imaging Committee, Society of Pediatric Radiology Oncology Committee, and American Society of Pediatric Neuroradiology.

Mother's physical activity during pregnancy and newborn's brain cortical development.

Background: Physical activity is known to improve mental health, and is regarded as safe and desirable for uncomplicated pregnancy. In this novel study, we aim to evaluate whether there are associations between maternal physical activity during pregnancy and neonatal brain cortical development. Methods: Forty-four mother/newborn dyads were included in this longitudinal study. Healthy pregnant women were recruited and their physical activity throughout pregnancy were documented using accelerometers worn for 3-7 days for each of the 6 time points at 4-10, ∼12, ∼18, ∼24, ∼30, and ∼36 weeks of pregnancy. Average daily total steps and daily total activity count as well as daily minutes spent in sedentary/light/moderate/vigorous activity modes were extracted from the accelerometers for each time point. At ∼2 weeks of postnatal age, their newborns underwent an MRI examination of the brain without sedation, and 3D T1-weighted brain structural images were post-processed by the iBEAT2.0 software utilizing advanced deep learning approaches. Cortical surface maps were reconstructed from the segmented brain images and parcellated to 34 regions in each brain hemisphere, and mean cortical thickness for each region was computed for partial correlation analyses with physical activity measures, with appropriate multiple comparison corrections and potential confounders controlled. Results: At 4-10 weeks of pregnancy, mother's daily total activity count positively correlated (FDR corrected P ≤ 0.05) with newborn's cortical thickness in the left caudal middle frontal gyrus (rho = 0.48, P = 0.04), right medial orbital frontal gyrus (rho = 0.48, P = 0.04), and right transverse temporal gyrus (rho = 0.48, P = 0.04); mother's daily time in moderate activity mode positively correlated with newborn's cortical thickness in the right transverse temporal gyrus (rho = 0.53, P = 0.03). At ∼24 weeks of pregnancy, mother's daily total activity count positively correlated (FDR corrected P ≤ 0.05) with newborn's cortical thickness in the left (rho = 0.56, P = 0.02) and right isthmus cingulate gyrus (rho = 0.50, P = 0.05). Conclusion: We identified significant relationships between physical activity in healthy pregnant women during the 1st and 2nd trimester and brain cortical development in newborns. Higher maternal physical activity level is associated with greater neonatal brain cortical thickness, presumably indicating better cortical development.

Impact of a statewide computed tomography scan educational campaign on radiation dose and repeat CT scan rates for transferred injured children.

PURPOSE: Research demonstrates that children receive twice as much medical radiation from Computed Tomography (CT) scans performed at non-pediatric facilities as equivalent CTs performed at pediatric trauma centers (PTCs). In 2014, AFMC outreach staff educated Emergency Department (ED) staff on appropriate CT imaging utilization to reduce unnecessary medical radiation exposure. We set out to determine the educational campaign's impact on injured children received radiation dose. METHODS: All injured children who underwent CT imaging and were transferred to a Level I PTC during 2010 to 2013 (pre-campaign) and 2015 (post-campaign) were reviewed. Patient demographics, mode of transportation, ED length of stay, scanned body region, injury severity score, and trauma center level were analyzed. Median effective radiation dose (ERD) controlled for each variable, pre-campaign and post-campaign, was compared using Wilcoxon rank sum test. RESULTS: Three hundred eighty-five children under 17 years were transferred from 45 and 48 hospitals, pre- and post-campaign. Most (43%) transferring hospitals were urban or critical access hospitals (30%). Pre- and post-campaign patient demographics were similar. We analyzed 482 and 398 CT scans pre- and post-campaign. Overall, median ERD significantly decreased from 3.80 to 2.80. Abdominal CT scan ERD declined significantly from 7.2 to 4.13 (P-value 0.03). Head CT scan ERD declined from 3.27 to 2.45 (P-value < 0.0001). CONCLUSION: A statewide, CT scan educational campaign contributed to ERD decline (lower dose scans and fewer repeat scans) among transferred injured children seen at PTCs. State-level interventions are feasible and can be effective in changing radiology provider practices.

Case Report: SATB2-Associated Syndrome Overlapping With Clinical Mitochondrial Disease Presentation: Report of Two Cases.

SATB2-associated syndrome (SAS) is an autosomal dominant neurogenetic multisystemic disorder. We describe two individuals with global developmental delay and hypotonia who underwent an extensive evaluation to rule out an underlying mitochondrial disorder before their eventual diagnosis of SAS. Although the strict application of the clinical mitochondrial disease score only led to the designation of "possible" mitochondrial disorder for these two individuals, other documented abnormalities included nonspecific neuroimaging findings on magnetic resonance imaging and magnetic resonance spectroscopy, decreased complex I activity on muscle biopsy for patient 2, and variation in the size and relative proportion of types of muscle fibers in the muscle biopsies that were aligned with mitochondrial diseases. SAS should be in the differential diagnoses of mitochondrial disorders, and broad-spectrum diagnostic tests such as exome sequencing need to be considered early in the evaluation process of undiagnosed neurodevelopmental disorders.

Spinal subdural hemorrhage in abusive head trauma: a pictorial review.

A growing body of evidence links abusive head trauma (AHT) to patterns of direct and indirect spinal injuries, such as spinal subdural hemorrhage (SDH). Identification of evidence of spinal injury such as spinal SDH plays a crucial role in the diagnosis and subsequent management of the index child with AHT and his or her siblings. In a value-based practice of medicine, it can be argued that adding spine imaging to identify spinal SDH in the workup of AHT adds value to both the short- and long-term management of the patient. This pictorial review describes the normal appearance of spinal SDH and challenges of identifying spinal SDH, and it explores the mechanism of spinal SDH development in AHT.

Spinal ligamentous injury in abusive head trauma: a pictorial review.

There is growing evidence of spine injury in abusive head trauma (AHT). Historically, spine injury was considered rare in AHT because of a lack of attributable clinical symptoms or signs and a lack of advanced imaging. Increased use of MRI in AHT has been instrumental in helping identify evidence of ligamentous injuries of the spine. These findings can be difficult to identify on autopsy because of the size and location of the ligaments. Because spinal injury in AHT mostly involves ligamentous and soft tissues and only rarely involves bony fractures, more than 90% of the injury findings are missed on CT or radiography of the spine. Investigation of these findings and the injury patterns should lead to a better understanding of the mechanism of spinal injury. In this pictorial review, we describe the various manifestations of spinal ligamentous injury in AHT, as seen on MRI, in children younger than 48 months.

Venous injury in pediatric abusive head trauma: a pictorial review.

Abusive head trauma (AHT) is the leading cause of fatal head injuries in children younger than 2 years. An intracranial pathology can exist even in the setting of a normal physical exam. A delay in the diagnosis of AHT can have serious life-threatening consequences for the child and increases the potential the child will be abused again. In this article, we review the traumatic subdural hematoma as well as various morpho-structural patterns of shearing injuries and thrombosis of intracranial bridging veins. This work serves as a summary of patterns of imaging features of intracranial venous injury in AHT, as described in the literature, to facilitate familiarity and early detection of abusive head trauma in the pediatric population. Essentially, in AHT there is a traumatic injury to the bridging vein with either partial or complete tear. This can secondarily result in thrombosis at the terminal end of the bridging vein with blood clots adjacent to the bridging vein.