The Sensitivity of Limited-Sequence MRI in Identifying Pediatric Cervical Spine Injury: A Western Pediatric Surgery Research Consortium Multicenter Retrospective Cohort Study.

INTRODUCTION: Clinical clearance of a child's cervical spine after trauma is often challenging due to impaired mental status or an unreliable neurologic examination. Magnetic resonance imaging (MRI) is the gold standard for excluding ligamentous injury in children but is constrained by long image acquisition times and frequent need for anesthesia. Limited-sequence MRI (LSMRI) is used in evaluating the evolution of traumatic brain injury and may also be useful for cervical spine clearance while potentially avoiding the need for anesthesia. The purpose of this study was to assess the sensitivity and negative predictive value of LSMRI as compared to gold standard full-sequence MRI as a screening tool to rule out clinically significant ligamentous cervical spine injury. METHODS: We conducted a ten-center, five-year retrospective cohort study (2017-2021) of all children (0-18y) with a cervical spine MRI after blunt trauma. MRI images were re-reviewed by a study pediatric radiologist at each site to determine if the presence of an injury could be identified on limited sequences alone. Unstable cervical spine injury was determined by study neurosurgeon review at each site. RESULTS: We identified 2,663 children less than 18 years of age who underwent an MRI of the cervical spine with 1,008 injuries detected on full-sequence studies. The sensitivity and negative predictive value of LSMRI were both >99% for detecting any injury and 100% for detecting any unstable injury. Young children (age < 5 years) were more likely to be electively intubated or sedated for cervical spine MRI. CONCLUSION: LSMRI is reliably detects clinically significant ligamentous injury in children after blunt trauma. To decrease anesthesia use and minimize MRI time, trauma centers should develop LSMRI screening protocols for children without a reliable neurologic exam. LEVEL OF EVIDENCE: 2 (Diagnostic Tests or Criteria).

Imaging of Central Nervous System Involvement in Pediatric Hematologic Disorders.

Hematologic disorders and malignancies are commonly encountered in children. The central nervous system is affected by many benign and malignant hematological diseases. Neurologic findings may occur due to central involvement of hematological disease or neurotoxic effects of treatment during the disease. At all these stages, radiological imaging and evaluation have a critical role. In this review article, we aim to describe the imaging findings of central nervous system involvement in pediatric hematologic diseases. This review was prepared based on the latest literature available in the PubMed database in the English language from inception to March 2022. The radiological images of the patients in our archive were obtained from the PACS (Picture Archiving and Communication Systems) to set an example for the diseases described in the text.

The use of 3D printing in shared decision making for a juvenile aggressive ossifying fibroma in a pediatric patient.

Juvenile aggressive ossifying fibromas (JAOF) are rare, typically benign pediatric tumors that are locally aggressive and have high recurrence rates. A 7-year old male presented with a palatal mass and a 3D printed model was created and used as a visual aide to highlight the importance of management in terms of functional, cosmetic, and disease-free outcomes with the family. The patient ultimately underwent successful enucleation with final pathology consistent with JAOF. To our knowledge, this is the first description of the use of 3D printing to help in the shared decision-making process for the treatment of this aggressive tumor.

Craniofacial Flash: Minimizing Radiation Dose in Pediatric Craniofacial Computed Tomography.

BACKGROUND AND PURPOSE: The routine use of computed tomography (CT) in evaluation of pediatric craniofacial abnormalities is controversial. While there are benefits to preoperative imaging, there are risks related to ionizing radiation and sedation/anesthesia. In this study, the authors describe their experience with a new craniofacial CT protocol (Craniofacial-Flash) that provides bone detail equivalent to conventional CT, while delivering a substantially lower radiation dose and reducing the scan time to obviate the requirement of sedation/anesthesia. METHODS: Following IRB approval, dose identification and image analysis were conducted retrospectively on all patients who underwent craniofacial CT using either the conventional protocol or Craniofacial-Flash protocol between November 2013 and September 2015. Image analysis consisted of automated segmentation of bone and soft tissue, followed by noise interpretation of each study segment. RESULTS: The conventional CT group included 175 patients (mean age 6.38 years) with a median dose length product of 243.00 mGy·cm. The Craniofacial-Flash CT group included 208 patients (mean age 3.31 years) with median dose length product of 27.60 mGy·cm. Image quality was equivalent for bone, with coefficient of variation values of 0.20 for the conventional CT group and 0.21 for the Craniofacial-Flash group. Soft tissues coefficients of variation were disparate at 0.07 for conventional CT and 0.14 for Craniofacial-Flash protocol. CONCLUSION: The Craniofacial-Flash protocol reliably generates craniofacial bone images adequate for routine use in craniofacial practice, while reducing the radiation dose by 88.87% compared with a conventional craniofacial CT scan, and eliminating the need for sedation.

Characterization of upper airway obstruction using cine MRI in children with residual obstructive sleep apnea after adenotonsillectomy.

OBJECTIVES/BACKGROUND: Tonsillectomy and adenoidectomy (T&A) lead to resolution of obstructive sleep apnea (OSA) in most children. However, OSA persists in about 25-40% of children. Cinematic magnetic resonance imaging (cine MRI) can aid the management of persistent OSA by localizing airway obstruction. We describe our experience in implementing and optimizing a cine MRI protocol by using a 3 Tesla MRI scanner, and the use of dexmedetomidine for sedation to improve reproducibility, safety, and diagnostic accuracy. PATIENTS/METHODS: Patients aged 3-18 years who underwent cine MRI for the evaluation of persistent OSA after T&A and failed positive airway pressure (PAP) therapy were included. Clinical data and the apnea-hyponea index were compared with quantitative and qualitative estimates of airway obstruction from imaging sequences. RESULTS: A total of 36 children were included with a mean age of 9.6 ± 4.6 (SD) years with 40% over 12 years of age. Two-thirds of them were boys. Seventeen out of 36 children (47%) had Down syndrome. Single site and multilevel obstruction were identified in 21 of 36 patients (58%) and in 12 of 36 patients (33%), respectively. All cine MRIs were performed without complications. Multiple regression analysis demonstrated that a combination of the minimum airway diameter and body mass index z-score best predicted OSA severity (P = 0.002). CONCLUSIONS: Cine MRI is a sensitive, safe, and noninvasive modality for visualizing upper airway obstruction in children with persistent OSA after T&A. Accurate identification of obstruction can assist in surgical planning in children who fail PAP therapy.

Straight to the Operating Room: An Emergent Surgery Track for Acute Testicular Torsion Transfers.

OBJECTIVE: To assess the effect of implementing an emergency surgery track for testicular torsion transfers. We hypothesized that transferring children from other facilities diagnosed with torsion straight to the operating room (STOR) would decrease ischemia time, lower costs, and reduce testicular loss. STUDY DESIGN: Demographics, arrival to incision time, hospital cost in dollars, and testicular outcome (determined by testicular ultrasound) at follow-up were retrospectively compared in all patients transferred to our tertiary care children's hospital with a diagnosis of testicular torsion from 2012 to 2016. Clinical data for STOR and non-STOR patients were compared by Wilcoxon rank-sum, 2-tailed t test, or Fisher exact test as appropriate. RESULTS: Sixty-eight patients met inclusion criteria: 35 STOR and 33 non-STOR. Children taken STOR had a shorter median arrival to incision time (STOR: 54 minutes vs non-STOR: 94 minutes, P < .0001) and lower median total hospital costs (STOR: $3882 vs non-STOR: $4419, P < .0001). However, only 46.8% of STOR patients and 48.4% of non-STOR patients achieved surgery within 6 hours of symptom onset. Testicular salvage rates in STOR and non-STOR patients were not significantly different (STOR: 68.4% vs non-STOR: 36.8%, P = .1), but follow-up was poor. CONCLUSIONS: STOR decreased arrival to incision time and hospital cost but did not affect testicular loss. The bulk of ischemia time in torsion transfers occurred before arrival at our tertiary care center. Further interventions addressing delays in diagnosis and transfer are needed to truly improve testicular salvage rates in these patients.

Targeted MAPK Pathway Inhibitors in Patients With Disseminated Pilocytic Astrocytomas.

This report presents a series of 5 pediatric patients with disseminated pilocytic astrocytomas and frequent nonfusion activating mutations. Genetic variants in these patients' tumors include BRAF p.Val600Glu, BRAF p.Val600Asp, and KRAS p.Gly60_Gln62ins7. The 2 patients with BRAF-mutated tumors were treated with dabrafenib or a combination of dabrafenib plus trametinib. The patients had either near complete resolution of the primary tumor (BRAF p.Val600Glu) or a stable primary tumor (BRAF p.Val600Asp). Both patients showed improvement in leptomeningeal dissemination without significant toxicity. Genomic testing of disseminated pilocytic astrocytomas, particularly those arising at extracerebellar locations, may result in the identification of mutations associated with ERK/MAPK activation. Patients with these activating mutations may benefit from targeted therapies.

Ionizing Radiation in Craniofacial Surgery: A Primer on Dose and Risks.

An understanding of radiation dose and the anticipated risk to the patient is an important aspect of ordering radiological imaging studies responsibly. It is especially true for the pediatric practitioner because children are more vulnerable to the biological effects of radiation, such as radiosensitivity, longer lifetime years, and higher cellular mitotic activity. The use of fluoroscopy and computed tomography is commonplace in the practice of craniofacial surgery, but often dose reports from varied investigations are not directly comparable, and the risk of patient harm from the investigation is unclear. This article presents the fundamentals of radiation, dose, and risk as it applies to radiological imaging and also introduces our low dose craniofacial computed tomography protocol.

A rare nasal cavity mass in a child: Accessory middle turbinate.

OBJECTIVES: The accessory middle turbinate, a rare anatomical variation of the nasal cavity, have been systematically studied in adults. Presence of accessory middle turbinate and its clinical significance in a child has not been reported. We describe clinical appearance and radiologic features of accessory middle turbinate in a child. METHODS: Retrospective chart review. RESULTS: A 3-year-old boy presented to the otolaryngology clinic for evaluation of recurrent epistaxis. Anterior rhinoscopy revealed moist nasal mucosa without inflammation and bilateral prominent blood vessels on the anterior nasal septum. Nasal endoscopy showed turbinate like protuberances in bilateral middle meatus. CT images documented accessory middle turbinate in the bilateral nasal cavity. CONCLUSION: Otolaryngologists should be cognizant of anatomical variations of middle turbinate to achieve correct diagnosis and avoid potential complications during surgical management.

Postoperative surveillance of pediatric cerebellar pilocytic astrocytoma.

The purpose of this study was to identify the optimal frequency and duration of magnetic resonance imaging follow-up in children who had gross totally resected cerebellar pilocytic astrocytomas (CPAs). Our hypothesis was that following two MR examinations, separated by at least 3 months, showing no evidence of tumor, gross totally resected CPAs did not recur and no further imaging follow-up was necessary. Retrospective review of Neuro-Oncology database from 1/2000 to 7/2013 yielded 53 patients with CPAs that had preoperative imaging and >2 years post-operative imaging follow-up available. Pilocytic astrocytomas with brainstem involvement and patients with neurofibromatosis type I were excluded. Preoperative tumor volumes were calculated. The dates and reports of the examinations were tabulated. The median number of follow-up examinations was 9 over a median follow-up time of 6.05 years (2.07-12.28 years). Two consecutive MR examinations over at least a 3 month span demonstrated the smallest negative likelihood ratio of future recurrence (0.15). There was no association of recurrence with preoperative tumor volume. Among the 35 patients with gross total resection of their tumor and greater than two negative follow-up examinations, one recurrence (2.9 %) was identified, occurring 6.4 years after initial resection. Gross totally resected pediatric CPAs can recur, but this is exceedingly rare. Frequent surveillance (every 3-6 months) is suggested in patients with CPAs until absence of tumor is concluded on imaging and documented on two consecutive studies spaced at least 3 months apart. The likelihood of recurrence thereafter is low.

Pediatric Sarcomas Are Targetable by MR-Guided High Intensity Focused Ultrasound (MR-HIFU): Anatomical Distribution and Radiological Characteristics.

BACKGROUND: Despite intensive therapy, children with metastatic and recurrent sarcoma or neuroblastoma have a poor prognosis. Magnetic resonance guided high intensity focused ultrasound (MR-HIFU) is a noninvasive technique allowing the delivery of targeted ultrasound energy under MR imaging guidance. MR-HIFU may be used to ablate tumors without ionizing radiation or target chemotherapy using hyperthermia. Here, we evaluated the anatomic locations of tumors to assess the technical feasibility of MR-HIFU therapy for children with solid tumors. PROCEDURE: Patients with sarcoma or neuroblastoma with available cross-sectional imaging were studied. Tumors were classified based on the location and surrounding structures within the ultrasound beam path as (i) not targetable, (ii) completely or partially targetable with the currently available MR-HIFU system, and (iii) potentially targetable if a respiratory motion compensation technique was used. RESULTS: Of the 121 patients with sarcoma and 61 patients with neuroblastoma, 64% and 25% of primary tumors were targetable at diagnosis, respectively. Less than 20% of metastases at diagnosis or relapse were targetable for both sarcoma and neuroblastoma. Most targetable lesions were located in extremities or in the pelvis. Respiratory motion compensation may increase the percentage of targetable tumors by 4% for sarcomas and 10% for neuroblastoma. CONCLUSIONS: Many pediatric sarcomas are localized at diagnosis and are targetable by current MR-HIFU technology. Some children with neuroblastoma have bony tumors targetable by MR-HIFU at relapse, but few newly diagnosed children with neuroblastoma have tumors amenable to MR-HIFU therapy. Clinical trials of MR-HIFU should focus on patients with anatomically targetable tumors.

Tectal Lesions in Children: A Long-Term Follow-Up Volumetric Tumor Growth Analysis in Surgical and Nonsurgical Cases.

BACKGROUND/AIMS: Different tectal masses have been described; most are low-grade gliomas. Only 20-30% of all lesions grow, as shown on follow-up MRIs, requiring surgical resection at some point. The aim of this study is to describe the experience of a single institution managing pediatric patients with tectal lesions. METHODS: We retrospectively studied and analyzed 40 children with tectal lesions managed from 1990 to 2006; the mean age at diagnosis was 9.4 years. A volumetric classification was used to analyze tumor growth trends. More than 1 year of imaging follow-up was available for 23 patients. RESULTS AND CONCLUSION: Medium- and large-volume-size lesions were associated with the need for surgery. About half of the nonsurgical lesions grew at least 50% over a period of 4.5 years and did not require surgical resection.

Recurrent unilateral facial nerve palsy in a child with dehiscent facial nerve canal.

OBJECTIVE: The dehiscent facial nerve canal has been well documented in histopathological studies of temporal bones as well as in clinical setting. We describe clinical and radiologic features of a child with recurrent facial nerve palsy and dehiscent facial nerve canal. METHODS: Retrospective chart review. RESULTS: A 5-year-old male was referred to the otolaryngology clinic for evaluation of recurrent acute otitis media and hearing loss. He also developed recurrent left peripheral FN palsy associated with episodes of bilateral acute otitis media. High resolution computed tomography of the temporal bones revealed incomplete bony coverage of the tympanic segment of the left facial nerve. CONCLUSIONS: Recurrent peripheral FN palsy may occur in children with recurrent acute otitis media in the presence of a dehiscent facial nerve canal. Facial nerve canal dehiscence should be considered in the differential diagnosis of children with recurrent peripheral FN palsy.

Pilomatricoma of Childhood: A Common Pathologic Diagnosis Yet a Rare Radiologic One.

OBJECTIVE: The purposes of this study were to determine the accuracy of radiology reports in the diagnosis of pediatric pilomatricoma and to describe the characteristic imaging findings in a large cohort. MATERIALS AND METHODS: Query of a pathology database between January 2009 and February 2014 yielded 623 specimens from 596 patients. Seventy-four patients (41 girls, 33 boys; mean age, 8.9 years) underwent imaging of the 80 excised lesions. Ninety imaging studies were available (58 ultrasound, 11 CT, 21 MRI). Radiology reports were reviewed. The lesions were evaluated for location, size, and imaging characteristics. RESULTS: Pilomatricoma was included as an indication for two (2.2%) imaging studies. No differential diagnosis was given in 34 (37.8%) imaging reports. In the radiology reports, pilomatricoma was suggested as a possibility for 12 (13.3%) lesions. Foreign body reaction (13.3%), dermoid cyst (10.0%), and sebaceous cyst (8.9%) were other leading suggested diagnoses. In six (6.7%) reports, lesions were described as aggressive tumors. In nine (10.0%) reports additional studies were recommended. In all examinations, the lesions involved both skin and subcutaneous tissues without infiltration of the deep tissues. Hypoechoic rim (82.8%), internal reticulations (65.5%), and flow at Doppler examination (63.2%) were the most common sonographic features. MRI characteristics were enhancement (100.0%), heterogeneous T2-weighted hyperintensity with intermixed hypointensity (76.2%), T1-weighted isointensity in relation to skeletal muscle (66.7%), and absence of restricted diffusion (100.0%). CONCLUSION: Although pilomatricoma is a common tumor of the skin and subcutaneous tissues, imaging is infrequently used in the diagnosis, and therefore, many radiologists are not aware of the lesion. The imaging features of pilomatricoma are consistent in all imaging modalities.

Lenticulostriate vasculopathy in neonates: Perspective of the radiologist.

Lenticulostriate vasculopathy (LSV) is a diagnosis dependent on neonatal cranial ultrasound (US). The diagnosis of LSV requires the presence of linear or branching echogenicities in the area of the basal ganglia and/or thalamus on gray scale cranial US. Although the diagnosis of LSV is dependent on cranial US, there are no convincing correlates observed on either computerized tomography or magnetic resonance imaging. Moreover, the radiographic criteria for LSV on cranial US remain vague, and intra-observer correlations are generally reported to be poor. The purpose of this review is to examine the issues associated with the use of cranial US and the diagnosis of LSV, including alternative imaging, clinical abnormalities and the significance of LSV on cranial US.

Applicability of apparent diffusion coefficient ratios in preoperative diagnosis of common pediatric cerebellar tumors across two institutions.

INTRODUCTION: The purpose of our study was to test the accuracy and applicability of decision rules utilizing apparent diffusion coefficient (ADC) ratios on accurate preoperative diagnosis of common pediatric cerebellar tumors across two institutions. METHODS: In this HIPAA-compliant, IRB-approved study, performed at two institutions, 140 pediatric cerebellar tumors were included. Two separate reviewers placed regions of interest on the solid components of 140 tumors (98 at site A and 42 at site B) and normal brain on the ADC maps. The third reviewer who was blinded to the histopathological diagnoses made the same measurements on 140 patients to validate the data. Tumor to normal brain ADC ratios were calculated. Receiver operator curve (ROC) analysis was performed to generate thresholds to discriminate tumors. Utility of decision rules based on these thresholds was tested. RESULTS: While ADC values of medulloblastomas were different between the sites, there was no difference among the ADC ratios of medulloblastomas, pilocytic astrocytomas, ependymomas, and atypical teratoid rhabdoid tumors between the sites. ADC ratio of ≥1.8 correctly discriminated pilocytic astrocytomas from ependymomas with a sensitivity of 0.83 and a specificity of 0.78. ADC ratio of <1.2 correctly discriminated ependymomas from embryonal tumors with a sensitivity of 0.87 and a specificity of 0.83. The proposed decision rules correctly discriminated 120 of the 140 tumors (85.71%). Age ≥2 years criterion correctly sorted medulloblastomas in 84.48% of patients and age <2 years correctly distinguished atypical teratoid rhabdoid tumors in 90.00% of patients with embryonal tumors. CONCLUSIONS: Decision rules based on ADC ratios are applicable across two institutions in the accurate preoperative diagnosis of common pediatric cerebellar tumors.

MRI of the petromastoid canal in children.

PURPOSE: To characterize the MRI features of the petromastoid canal in children with sensorineural hearing loss (SNHL) and in normal infants. MATERIALS AND METHODS: High resolution MRI examinations of 564 children who were evaluated for SNHL and brain MRI examinations of 112 infants who had normal studies were studied independently by two reviewers. RESULTS: In SNHL group, visibility of the PMC decreased for right and left PMC (P < 0.001). The width of the right PMC significantly decreased as age increased (P < 0.0001). There was no relation between abnormalities of membranous labyrinth and cochlear nerve and PMC visibility in children with SNHL (p > 0.05). In the normal group, the PMC visibility decreased with increasing age (right P = 0.0001, left P = 0.001). In the normal group also, as age increased, the PMC width decreased for both PMCs (right, P = 0.0006; left, P = 0.03). CONCLUSION: The PMC is more frequently visualized in young children. Its visibility and width are not associated with abnormalities of membranous labyrinth and cochlear nerves.