Incidental Thalamic Lesions Identified on Brain MRI in Pediatric and Young Adult Patients: Imaging Features and Natural History.

BACKGROUND AND PURPOSE: Nonspecific, localized thalamic signal abnormalities of uncertain significance are occasionally found on pediatric brain MR imaging. The goal of this study is to describe the MR imaging appearance and natural history of these lesions in children and young adults. MATERIALS AND METHODS: This retrospective study evaluated clinically acquired brain MR imaging examinations obtained from February 1995 to March 2022 at a large, tertiary care pediatric hospital. Examinations with non-mass-like and nonenhancing thalamic lesions were identified based on term search of MR imaging reports. A total of 221 patients formed the initial group for imaging assessment. Additional exclusions during imaging review resulted in 171 patients. Imaging appearance and size changes were assessed at baseline and at follow-up examinations. RESULTS: A total of 171 patients (102 male) at a median age of 11 years (range: 1-23 years), 568 MR imaging examinations, and 180 thalamic lesions were included. Median time from baseline to the last follow-up MR imaging was 542 days (range: 46-5730 days). No lesion enhanced at any time point. On imaging follow-up, 11% of lesions (18/161) became smaller, 10% (16/161) resolved, 73% (118/161) remained stable, and 6% (9/161) increased in size at some point during evaluation. Median time interval from baseline to enlargement was 430 days (range: 136-1074 days). CONCLUSIONS: Most incidental, non-mass-like thalamic signal abnormalities were stable, decreased in size, or resolved on follow-up imaging and are likely of no clinical significance. Surveillance strategies with longer follow-up intervals may be adequate in the management of such findings.

Understanding Bilateral Skull Fractures in Infancy: A Retrospective Multicenter Case Review.

BACKGROUND: Bilateral skull fractures in infancy often raise suspicion for abuse. Nevertheless, literature suggests that they may occur accidentally. However, empiric data are lacking. OBJECTIVE: This multicenter retrospective review aimed to characterize bilateral skull fractures in a large sample. PARTICIPANTS AND SETTING: Medical records for infants younger than 24 months with bilateral skull fractures involving hospital consultation with a child abuse pediatrician (CAP) were reviewed from 2005 to 2020 at 13 nationally represented institutions. METHODS: Standardized data collection across institutions included historical features, fracture characteristics, and additional injuries, as well as the CAP's determination of accident versus abuse. Pooled data were analyzed for descriptive and bivariate analyses. RESULTS: For 235 cases, 141 were accidental, and 94 abuse. The majority occurred in young infants, and a history of a fall was common in 70% of cases. More than 80% involved both parietal bones. Bilateral simple linear fractures were more common in accidental cases, 79% versus 35%, whereas a complex fracture was more frequent in abuse cases, 55% versus 21% ( P < 0.001). Almost two thirds of accidental cases showed approximation of the fractures at the sagittal suture, compared with one third of abuse cases ( P < 0.001). Whereas focal intracranial hemorrhage was seen in 43% of all cases, diffuse intracranial hemorrhage was seen more in abuse cases (45%) than accidents (11%). Skin trauma was more common in abusive than accidental injury (67% vs 17%, P < 0.001), as were additional fractures on skeletal survey (49% vs 3%, P < 0.001). CONCLUSIONS: A fall history was common in bilateral skull fractures deemed accidental by a CAP. Most accidental cases involved young infants with biparietal simple linear fractures, without skin trauma or additional fractures. A skeletal survey may aid in the determination of accidental or abusive injury for unwitnessed events resulting in bilateral skull fractures in infants.

Cerebral vascular injury in transplant-associated thrombotic microangiopathy.

Transplant-associated thrombotic microangiopathy (TA-TMA) and atypical hemolytic uremic syndrome (aHUS) are complement-mediated TMAs. The central nervous system (CNS) is the most common extrarenal organ affected by aHUS, and, despite mechanistic overlap between aHUS and TA-TMA, CNS involvement is rarely reported in TA-TMA, suggesting that CNS involvement in TA-TMA may be underdiagnosed and that these patients may benefit from complement blockers. In addition, there are no widely used histologic or radiologic criteria for the diagnosis of TMA in the brain. Thirteen recipients of pediatric hematopoietic cell transplants (HCTs) who had TA-TMA and who underwent autopsy were studied. Seven of 13 brains had vascular injury, and 2 had severe vascular injury. Neurologic symptoms correlated with severe vascular injury. Classic TMA histology was present and most often observed in the cerebellum, brainstem, and cerebral white matter. Abnormalities in similar anatomic regions were seen on imaging. Brain imaging findings related to TMA included hemorrhages, siderosis, and posterior reversible encephalopathy syndrome. We then studied 100 consecutive HCT recipients to identify differences in neurologic complications between patients with and those without TA-TMA. Patients with TA-TMA were significantly more likely to have a clinical concern for seizure, have an electroencephalogram performed, and develop altered mental status. In summary, our study confirms that TA-TMA involves the brains of recipients of HCT and is associated with an increased incidence of neurologic symptoms. Based on these findings, we propose that patients with low- or moderate-risk TA-TMA who develop neurologic complications should be considered for TA-TMA-directed therapy.

Parenchymal Insults in Abuse-A Potential Key to Diagnosis.

Subdural hemorrhage is a key imaging finding in cases of abusive head trauma and one that many radiologists and radiology trainees become familiar with during their years of training. Although it may prove to be a marker of trauma in a young child or infant that presents without a history of injury, the parenchymal insults in these young patients more often lead to the debilitating and sometimes devastating outcomes observed in this young population. It is important to recognize these patterns of parenchymal injuries and how they may differ from the imaging findings in other cases of traumatic injury in young children. In addition, these parenchymal insults may serve as another significant, distinguishing feature when making the medical diagnosis of abusive head injury while still considering alternative diagnoses, including accidental injury. Therefore, as radiologists, we must strive to look beyond the potential cranial injury or subdural hemorrhage for the sometimes more subtle but significant parenchymal insults in abuse.

Craniosynostosis is a feature of Costello syndrome.

Costello syndrome (CS) is an autosomal dominant disorder caused by pathogenic variants in HRAS. Craniosynostosis is a known feature of other RASopathies (Noonan and cardiofaciocutaneous syndromes) but not CS. We describe four individuals with CS and craniosynostosis and present a summary of all previously reported individuals with craniosynostosis and RASopathy.

Macrocephaly and subdural collections.

Enlarged subarachnoid spaces are a common finding in infants and young children imaged for macrocephaly or an enlarging head circumference, and benign enlargement of the subarachnoid spaces is often diagnosed. Infrequently, presumed "spontaneous" subdural hemorrhages or subdural collections might complicate these enlarged subarachnoid spaces. Children with large bilateral subdural collections might also present for imaging with macrocephaly. Each scenario potentially raises concerns for prior injury because subdural hemorrhage is a frequent finding in children with abusive head trauma.

Debunking Fringe Beliefs in Child Abuse Imaging: AJR Expert Panel Narrative Review.

Child abuse is a global public health concern. Injuries from physical abuse may be clinically occult and not appreciable on physical examination. Imaging is therefore critical in identifying and documenting such injuries. The radiologic approach for a child who has potentially been abused has received considerable attention and recommendations according to decades of experience and rigorous scientific study. Nonetheless, fringe beliefs describing alternative explanations for child abuse-related injuries have emerged and received mainstream attention. Subsequently, imaging findings identified in abused children have been attributed to poorly supported underlying medical conditions, clouding the evidence basis for radiologic findings indicative of nonaccidental trauma. Fringe beliefs that attribute findings seen in child abuse to alternate pathologies such as genetic disorders, birth trauma, metabolic imbalances, vitamin D deficiency, and short-distance falls typically have limited evidence basis and lack professional society support. Careful review of the scientific evidence and professional society consensus statements is important in differentiating findings attributable to child abuse from fringe beliefs used to discount the possibility that a child's constellation of injuries is consistent with abuse. This review refutes fringe beliefs used to provide alternative explanations in cases of suspected child abuse and reinforces the key literature and scientific consensus regarding child abuse imaging.

Pediatric hanging and strangulation: is vascular injury a true risk?

BACKGROUND: Acute screening of pediatric strangulation and hanging injuries has evolved at many institutions to include cervical arterial vascular imaging. As current standards in pediatric imaging support less radiation exposure and increased imaging appropriateness, it is questionable whether vascular arterial injury is a true risk in this population. OBJECTIVE: To determine the role of cervical vascular arterial imaging in the evaluation of pediatric hanging and strangulation injuries. MATERIALS AND METHODS: This is a retrospective study of patients who present at a Level 1 pediatric trauma center with a history of hanging and strangulation injuries. All relevant studies, including computed tomography (CT) angiography of the neck, contrast-enhanced neck CT, cervical magnetic resonance (MR) angiography, magnetic resonance imaging (MRI) and/or CT of the brain and cervical spine and associated clinical records, were reviewed. RESULTS: Sixty-six patients were identified, 60 with vascular arterial imaging studies. No vascular injury was identified. Soft-tissue injury was noted in 20/66 (30%) patients and craniocervical injury was suspected in 2/66 (3%), but no cervical spine fracture was identified. Only 49 patients had brain imaging, with 7/49 (14%) demonstrating changes consistent with cerebral edema, which correlated negatively with survival (P<0.01). CONCLUSION: Vascular arterial imaging, particularly with CT angiography, performed in the pediatric population after hanging and strangulation injury resulted in no positive studies for cervical arterial injury. This study supports the need to reevaluate routine screening CT angiography in this study population.

Pediatric Emergencies: Imaging of Pediatric Head Trauma.

Pediatric head trauma is an important cause of morbidity and mortality in children and may be seen in the setting of accidental or abusive injuries. Although many of the patterns of head injury are similar to adults, the imaging manifestations of head injury in children are more complex due to the developing brain and calvarium. Additionally, there are unique considerations for mechanisms of injury in children, to include abusive head trauma and birth-related injuries. The primary role of the radiologist is to identify and characterize the type and severity of head injury to help guide appropriate patient management.

Pediatric Spinal Ultrasound: Neonatal and Intraoperative Applications.

The purpose of this article is to review the use of ultrasound as a screening tool for spinal diseases in neonates and infants and its intraoperative value in selected pediatric neurosurgical disorders. A review of spinal embryology followed by a description of common spinal diseases in neonates assessed with ultrasound is presented. Indications for spinal ultrasound in neonates, commonly identified conditions, and the importance of magnetic resonance imaging in selected cases are emphasized. Additionally, the use of ultrasound in selected neurosurgical spinal diseases in pediatric patients is presented with magnetic resonance imaging and intraoperative correlation. Technique, limitations, and pitfalls are discussed.

Clinical validation of synthetic brain MRI in children: initial experience.

INTRODUCTION: The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. METHODS: Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences. Two exams for each patient were de-identified. Four blinded reviewers reviewed eight patients and were asked to generate clinical reports on each exam (synthetic or conventional) at two different time points separated by a mean of 33 days. Exams were rated for overall and specific finding agreement (synthetic/conventional and compared to gold standard consensus review by two senior reviewers with knowledge of clinical report), quality, and diagnostic confidence. RESULTS: Overall agreement between conventional and synthetic exams was 97%. Agreement with consensus readings was 84% (conventional) and 81% (synthetic), p = 0.61. There were no significant differences in sensitivity, specificity, or accuracy for specific imaging findings involving the ventricles, CSF, brain parenchyma, or vasculature between synthetic or conventional exams (p > 0.05). No significant difference in exam quality, diagnostic confidence, or noise/artifacts was noted comparing studies with synthetic or conventional sequences. CONCLUSIONS: Diagnostic accuracy and quality of synthetically generated sequences are comparable to conventionally acquired sequences as part of a standard pediatric brain exam. Further confirmation in a larger study is warranted.

Reduced Field of View Diffusion-Weighted Imaging in the Evaluation of Congenital Spine Malformations.

BACKGROUND: Reduced field of view diffusion-weighted imaging (rFOV DWI) is a more recently described technique in the evaluation of spine pathology. In adults, this technique has been shown to increase clinician confidence in identification of diffusion restricting lesions. PURPOSE: In this study, we evaluate the image quality and diagnostic confidence of the rFOV DWI technique in pediatric spine MRI. METHODS: We included patients with MRI of the lumbar spine for suspected congenital abnormalities who had conventional SS-EPI (single shot echo planar imaging) with full field of view (fFOV) and rFOV DWI performed. Images were graded for image quality and observer confidence for detection of lesions with reduced diffusion. Position of the conus and L3 vertebral body measurements were recorded. Comparisons were made between the fFOV and rFOV scores. RESULTS: Fifty children (30 girls, 20 boys) were included (median 3.6 years). Compared to the fFOV images, the rFOV images scored higher in image quality (P < 0.0001) and for confidence in detecting lesions with reduced diffusion (P < 0.0001). The average spread of identified conus position was smaller for in rFOV compared to fFOV (P = 0.0042). There was no significant difference in the L3 vertebral body measurements between the two methods. In rFOV, the anterior aspects of the vertebral bodies were excluded in a few studies due to narrow FOV. CONCLUSION: rFOV DWI of the lumbar spine in the pediatric population has qualitatively improved image quality and observer confidence for lesion detection when compared to conventional fFOV SS-EPI DWI.

Everolimus for subependymal giant cell astrocytoma: 5-year final analysis.

OBJECTIVE: To analyze the cumulative efficacy and safety of everolimus in treating subependymal giant cell astrocytomas (SEGA) associated with tuberous sclerosis complex (TSC) from an open-label phase II study (NCT00411619). Updated data became available from the conclusion of the extension phase and are presented in this ≥5-year analysis. METHODS: Patients aged ≥ 3 years with a definite diagnosis of TSC and increasing SEGA lesion size (≥2 magnetic resonance imaging scans) received everolimus starting at 3mg/m(2) /day (titrated to target blood trough levels of 5-15ng/ml). The primary efficacy endpoint was reduction from baseline in primary SEGA volume. RESULTS: As of the study completion date (January 28, 2014), 22 of 28 (78.6%) initially enrolled patients finished the study per protocol. Median (range) duration of exposure to everolimus was 67.8 (4.7-83.2) months; 12 (52.2%) and 14 (60.9%) of 23 patients experienced SEGA volume reductions of ≥50% and ≥30% relative to baseline, respectively, after 60 months of treatment. The proportion of patients experiencing daily seizures was reduced from 7 of 26 (26.9%) patients at baseline to 2 of 18 (11.1%) patients at month 60. Most commonly reported adverse events (AEs) were upper respiratory tract infection and stomatitis of mostly grade 1 or 2 severity. No patient discontinued treatment due to AEs. The frequency of emergence of most AEs decreased over the course of the study. INTERPRETATION: Everolimus continues to demonstrate a sustained effect on SEGA tumor reduction over ≥5 years of treatment. Everolimus remained well-tolerated, and no new safety concerns were noted.

The striated MR nephrogram, not a reflection of pathology.

BACKGROUND: We have intermittently observed low signal striations in the kidneys on delayed post-contrast MR exams of the spine. While we suspected these striations were due to concentrated gadolinium, the clinical importance of this finding was uncertain. OBJECTIVE: To describe the striated MR nephrogram (low signal striations in the kidney) and assess its clinical relevance. MATERIALS AND METHODS: Retrospective review of delayed post-contrast MRIs of the spine (mean: 45 min after contrast administration). The presence of the striated MR nephrogram was correlated with imaging parameters (field strength, time since contrast), and findings (gadolinium in the bladder, inferior vena cava and aorta diameters) and with clinical factors (history of renal disease, laboratory values). RESULTS: Seven hundred seventy-three exams performed on 229 patients, 8.3 ± 5.3 years of age, were reviewed. The striated MR nephrogram was observed in 102/773 examinations (13.2%) and was present on at least one study in 54/229 patients (23.6%). The presence of striations was associated with the specific magnet on which the exam was performed (P < 0.01) but not with magnet field strength. Serum creatinine was minimally lower in patients with striations (0.43 ± 0.12 vs. 0.49 ± 0.18 mg/dL, P = 0.002), but no other clinical or historical data, including time from contrast administration (P = 0.54), fluid status (P = 0.17) and clinical history of renal disease (P = 0.14), were predictive of the presence of striations. CONCLUSION: The striated MR nephrogram was observed in 13% of delayed post-contrast MR exams of the spine. Precipitating factors are unclear, but the striated nephrogram does not appear to be a marker of clinically apparent renal dysfunction.

Adding Insult to Injury: Nonconvulsive Seizures in Abusive Head Trauma.

The primary objectives of this study were to determine the prevalence of nonconvulsive seizures and nonconvulsive status epilepticus in patients with abusive head trauma who underwent electroencephalography (EEG) monitoring and to describe predictive factors for this population. Children with a diagnosis of abusive head trauma were studied retrospectively to determine the rate of EEG monitoring, the rate of nonconvulsive seizures and nonconvulsive status epilepticus, and the associated neuroimaging findings. Over 11 years, 73 of 199 (36.8%) children with abusive head trauma had electroencephalography monitoring performed. Of these, 20 (27.4%) had nonconvulsive seizures and 3 (4.1%) had nonconvulsive status epilepticus. The presence of subarachnoid hemorrhage and cortical T2 / fluid-attenuated inversion recovery signal abnormalities were both significantly associated with the presence of nonconvulsive seizures / nonconvulsive status epilepticus. Nonconvulsive seizures are relatively common in abusive head trauma and may go unrecognized. Specific neuroimaging characteristics increase the likelihood of nonconvulsive seizures on EEG.

Utility of head computed tomography in children with a single extremity fracture.

OBJECTIVES: To determine the clinical and forensic utility of head computed tomography (CT) in children younger than 2 years of age with an acute isolated extremity fracture and an otherwise-negative skeletal survey. STUDY DESIGN: Retrospective chart review of children younger than 2 years of age who obtained a skeletal survey in the Cincinnati Children's Hospital Medical Center Emergency Department during the 159-month study period. Clinically important head injury was determined based on previously defined Pediatric Emergency Care Applied Research Network criteria. Forensically significant head injury was defined as that which increased the concern for inflicted injury. The rate of head CT relative to patient age and location of fracture (proximal vs distal extremity, upper vs. lower extremity) was determined via χ2 tests. RESULTS: Of the 320 children evaluated, 37% received neuroimaging, 95.7% of which had no signs of skull fracture or intracranial trauma. Five children (4.3%) with head imaging had traumatic findings but no children in the study had clinically significant head injury. Three of these children had previous concerns for nonaccidental trauma and findings on head CT that were forensically significant. There was a greater rate of head imaging in children in the younger age groups and those with proximal extremity fractures (P < .05). CONCLUSIONS: In young children who present with an isolated extremity fracture, clinicians should consider obtaining head CT in those who are younger than 12 months of age, have proximal extremity fractures, or who have previous evaluations for nonaccidental trauma. Evaluation with head CT in children without these risk factors may be low yield.

Combined analysis of sMRI and fMRI imaging data provides accurate disease markers for hearing impairment.

In this research, we developed a robust two-layer classifier that can accurately classify normal hearing (NH) from hearing impaired (HI) infants with congenital sensori-neural hearing loss (SNHL) based on their Magnetic Resonance (MR) images. Unlike traditional methods that examine the intensity of each single voxel, we extracted high-level features to characterize the structural MR images (sMRI) and functional MR images (fMRI). The Scale Invariant Feature Transform (SIFT) algorithm was employed to detect and describe the local features in sMRI. For fMRI, we constructed contrast maps and detected the most activated/de-activated regions in each individual. Based on those salient regions occurring across individuals, the bag-of-words strategy was introduced to vectorize the contrast maps. We then used a two-layer model to integrate these two types of features together. With the leave-one-out cross-validation approach, this integrated model achieved an AUC score of 0.90. Additionally, our algorithm highlighted several important brain regions that differentiated between NH and HI children. Some of these regions, e.g. planum temporale and angular gyrus, were well known auditory and visual language association regions. Others, e.g. the anterior cingulate cortex (ACC), were not necessarily expected to play a role in differentiating HI from NH children and provided a new understanding of brain function and of the disorder itself. These important brain regions provided clues about neuroimaging markers that may be relevant to the future use of functional neuroimaging to guide predictions about speech and language outcomes in HI infants who receive a cochlear implant. This type of prognostic information could be extremely useful and is currently not available to clinicians by any other means.

Everolimus long-term safety and efficacy in subependymal giant cell astrocytoma.

OBJECTIVE: To report long-term efficacy and safety data for everolimus for the treatment of subependymal giant cell astrocytoma (SEGA) in patients with tuberous sclerosis complex (TSC). METHODS: This was an open-label extension phase of a prospective, phase 1-2 trial (NCT00411619) in patients ≥3 years of age with SEGA associated with TSC. Patients received oral everolimus starting at 3 mg/m2 per day and subsequently titrated, subject to tolerability, to attain whole blood trough concentrations of 5-15 ng/mL. Change in SEGA volume, seizures, and safety assessments were the main outcome measures. RESULTS: Of 28 patients enrolled, 25 were still under treatment at the time of analysis. Median dose was 5.3 mg/m2/day and median treatment duration was 34.2 months (range 4.7-47.1). At all time points (18, 24, 30, and 36 months), primary SEGA volume was reduced by ≥30% from baseline (treatment response) in 65%-79% of patients. All patients reported ≥1 adverse event (AE), mostly grade 1/2 in severity, consistent with that previously reported, and none led to everolimus discontinuation. The most commonly reported drug-related AEs were upper respiratory infections (85.7%), stomatitis (85.7%), sinusitis (46.4%), and otitis media (35.7%). No drug-related grade 4 or 5 events occurred. CONCLUSION: Everolimus therapy is safe and effective for longer term (median exposure 34.2 months) treatment of patients with TSC with SEGA. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that everolimus, titrated to trough serum levels of 5-15 ng/mL, was effective in reducing tumor size in patients with SEGA secondary to TSC for a median of 34 months.