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.

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.

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.

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.

Ultra-Low-Dose Computed Tomography Protocol for Preoperative Evaluation in Children With Craniofacial Anomalies.

PURPOSE: Preoperative three-dimensional computed tomography is currently the gold standard imaging modality in patients with craniofacial anomalies. In these patients, bone structural evaluation is paramount for surgical planning and evaluation of brain parenchyma is often secondary. With the significant complexity of these patients, a majority of patients undergo multiple Computed Tomography (CT) studies from infancy into adulthood. This study presents an ultra-low-dose CT protocol that limits the radiation exposure per CT scan in patients with craniofacial anomalies. MATERIAL AND METHODS: A total of 200 consecutive patients who underwent head CT for preoperative evaluation of craniofacial anomalies at Tertiary Children's Hospital were included in the study. The kVp, (KiloVoltage Peak) mA (milliAnperage), CT dose index (CTDI), and dose-length product (DLP) were documented from the dose page. Patients were stratified based on age for determining age specific effective dose and for age matched comparison. The age specific effective dose was derived by using the established conversion factor as described in the paper. (1) Standard t test was performed to determine the statistical significance of radiation dose reduction. The Institutional Review Board approved the study and data was collected from 2012-2014. FINDINGS: Of the 200 patients assessed in our study, 90 patients had low-dose CT scans and 110 patients had ultra-low-dose CT scans of the head. All patients had diagnostic quality CT studies. The low-dose CT was performed at 120 kVp and 100 mA. The ultra-low-dose CT was performed at 80 kVp and fixed 80 mA. The minimum, maximum and mean effective dose before the introduction of the ultra-low-dose protocol was 0.8 mSv, 6.9 mSV and 2.82 mSv. The minimum, maximum and mean effective dose after the introduction of the ultra-low-dose protocol was 0.6 mSv, 3.8 mSV, and 1.37 mSv. The reduction in the effective radiation dose was statistically significant (standard t test; P = 0.0001). CONCLUSION: Compared to the regular low-dose protocol, the ultra-low-dose CT protocol provided appropriate diagnostic images with a significantly decreased radiation dose.

Injured Children Receive Twice the Radiation Dose at Nonpediatric Trauma Centers Compared With Pediatric Trauma Centers.

BACKGROUND: Use of cranial CT scans in children has been increasing, in part due to increased awareness of sports-related concussions. CT is the largest contributor to medical radiation exposure, a risk factor for cancer. Long-term cancer risks of CT scans can be two to three times higher for children than for adults because children are more radiosensitive and have a longer lifetime in which to accumulate exposure from multiple scans. STUDY AIM: To compare the radiation exposure injured children receive when imaged at nonpediatric hospitals (NPHs) versus pediatric hospitals. METHODS: Injured children younger than 18 years who received a CT scan at a referring hospital during calendar years (CYs) 2010 and 2013 were included. Patient-level factors included demographics, mode of transportation, and Injury Severity Score, and hospital-level factors included region of state, radiology services, and hospital type and size. Our primary outcome of interest was the effective radiation dose. RESULTS: Four hundred eighty-seven children were transferred to the pediatric trauma center during CYs 2010 and 2013, with a median age of 7.2 years (interquartile range 5-13). The median effective radiation dose received at NPHs was twice that received at the pediatric trauma center (3.8 versus 1.6 mSv, P < .001). Results were confirmed in independent and paired analyses, after controlling for mode of transportation, emergency department disposition, level of injury severity, and at the NPH trauma center level, hospital type, size, region, and radiology services location. CONCLUSION: NPHs have the potential to substantially reduce the medical radiation received by injured children. Pediatric CT protocols should be considered.

Idiopathic Intracranial Hypertension Progressing to Venous Sinus Thrombosis, Subarachnoid Hemorrhage, and Stroke.

Idiopathic intracranial hypertension (IIH) is a syndrome characterized by increased intracranial pressure (ICP), the absence of structural lesions on neuroimaging, and normal cerebrospinal fluid composition. Cerebral venous sinus thrombosis (CVST) is a common cause of increased ICP and can be differentiated from IIH with magnetic resonance venography. We describe a young woman with typical IIH who underwent lumbar puncture and was treated with a short course of high-dose corticosteroids followed by acetazolamide. She subsequently developed CVST, subarachnoid hemorrhage, and stroke. Risk factors that may have resulted in CVST are discussed.

Diplopia is better than no plopia!

Idiopathic intracranial hypertension often presents with cranial nerve VI paresis. Infrequently, other cranial nerve dysfunction may occur. We report a case of idiopathic intracranial hypertension that presented with bilateral cranial nerve III paresis. Review of the literature suggests that severe elevation of intracranial pressure may predispose patients with idiopathic intracranial hypertension to cranial nerve III dysfunction.

Utility of an allograft tendon for scoliosis correction via the costo-transverse foreman.

Current convex tethering techniques for treatment of scoliosis have centered on anterior convex staples or polypropylene tethers. We hypothesized that an allograft tendon tether inserted via the costo-transverse foramen would correct an established spinal deformity. In the pilot study, six 8-week-old pigs underwent allograft tendon tethering via the costo-transverse foreman or sham to test the strength of the transplanted tendon to retard spine growth. After 4 months, spinal deformity in three planes was induced in all animals with allograft tendons. In the treatment study, the allograft tendon tether was used to treat established scoliosis in 11 8-week-old pigs (spinal deformity > 50°). Once the deformity was observed (4 months) animals were assigned to either no treatment group or allograft tendon tether group and progression assessed by monthly radiographs. At final follow-up, coronal Cobb angle and maximum vertebral axial rotation of the treatment group was significantly smaller than the non-treatment group, whereas sagittal kyphosis of the treatment group was significantly larger than the non-treatment group. In sum, a significant correction was achieved using a unilateral allograft tendon spinal tether, suggesting that an allograft tendon tethering approach may represent a novel fusion-less procedure to correct idiopathic scoliosis. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:183-192, 2017.

The Clinical Impact of a Web-Based Image Repository on Radiation Exposure in Injured Children.

PURPOSE: The long-term cancer risks for children exposed to radiologic images can be two to three times higher than for adults because children are more sensitive to radiation and have a longer lifetime in which to accumulate exposure from CT scans. Injured children often undergo repeat CT imaging if they are transferred from non-pediatric hospitals to a Level I pediatric trauma center (PTC). This study determined the impact of a statewide web-based image repository (WBIR) on repeat imaging among transferred injured children. METHODS: All injured children who underwent CT imaging and were transferred to the PTC in 2010 (pre-WBIR) and 2013 (post-WBIR) were included. Patient-level factors studied included demographics, body region of scan, Injury Severity Score, and Emergency Department (ED) disposition. Change from pre to post on rate of repeat imaging was assessed. RESULTS: Two hundred fifty-four and 233 children, with a median age of 7.3 years, were transferred to the Children's Hospital in 2010 and 2013, respectively. Repeat imaging levels at the PTC were lower post-WBIR than pre-WBIR (20% versus 33%, odds ratio [OR] 0.54, P = .005). Images of the head decreased most significantly (60% versus 33%, OR 0.33). Images performed at Level II and III trauma centers were repeated less often after WBIR. CONCLUSIONS: The WBIR significantly reduced repeat imaging among injured children transferred to a PTC, especially children transferred from Level II and Level III trauma centers, children with lower-acuity injuries, and children with initial scans of the head. Radiation savings are expected to be beneficial to children.