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Objective: To evaluate the prenatal diagnosis of closed dysraphism (CD) and its correlation with postnatal findings and neonatal adverse outcomes., Methods: A retrospective cohort study including pregnancies diagsnosed with fetal CD by prenatal ultrasound (US) and magnetic resonance imaging (MRI) at a single tertiary center between September 2011 and July 2021., Results: CD was diagnosed prenatally and confirmed postnatally in 12 fetuses. The mean gestational age of prenatal imaging was 24.2 weeks, in 17% the head circumference was ≤fifth percentile and in 25% the cerebellar diameter was ≤fifth percentile. US findings included banana sign in 17%, and lemon sign in 33%. On MRI, posterior fossa anomalies were seen in 33% of cases, with hindbrain herniation below the foramen magnum in two cases. Mean clivus-supraocciput angle (CSA) was 74°. Additional anomalies outside the CNS were observed in 50%. Abnormal foot position was demonstrated prenatally in 17%. Neurogenic bladder was present in 90% of patients after birth., Conclusion: Arnold Chiari II malformation and impaired motor function can be present on prenatal imaging of fetuses with CD and may be associated with a specific type of CD. Prenatal distinction of CD can be challenging. Associated extra CNS anomalies are frequent and the rate of neurogenic urinary tract dysfunction is high., (© 2023 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Neurotuberculosis is defined as a tuberculous infection of the meninges, brain parenchyma, vessels, cranial and spinal nerves, spinal cord, skull, and spine that can occur either in a localized or in a diffuse form. It is a heterogeneous disease characterized by many imaging appearances and it has been defined as "the great mimicker" due to similarities with many other conditions. The diagnosis of central nervous system (CNS) tuberculosis (TB) is based on clinical presentation, neuroimaging findings, laboratory and microbiological findings, and comprehensive evaluation of the response to anti-TB drug treatment. However, the absence of specific symptoms, the wide spectrum of neurological manifestations, the myriad of imaging findings, possible inconclusive laboratory results, and the paradoxical reaction to treatment make the diagnosis often challenging and difficult, potentially delaying adequate treatment with possible devastating short-term and long-term neurologic sequelae. Familiarity with the imaging characteristics helps in accurate diagnosis and may prevent or limit significantly morbidity and mortality. The goal of this review is to provide a comprehensive up-to-date overview of the conventional and advanced imaging features of CNS TB for radiologists, neuroradiologists, and pediatric radiologists. We discuss the most typical neurotuberculosis imaging findings and their differential diagnosis in children and adults with the goal to provide a global overview of this entity., (© 2023 American Society of Neuroimaging.)

Ataxia is one of the most common pediatric movement disorders and can be caused by a large number of congenital and acquired diseases affecting the cerebellum or the vestibular or sensory system. It is mainly characterized by gait abnormalities, dysmetria, intention tremor, dysdiadochokinesia, dysarthria, and nystagmus. In young children, ataxia may manifest as the inability or refusal to walk. The diagnostic approach begins with a careful clinical history including the temporal evolution of ataxia and the inquiry of additional symptoms, is followed by a meticulous physical examination, and, depending on the results, is complemented by laboratory assays, electroencephalography, nerve conduction velocity, lumbar puncture, toxicology screening, genetic testing, and neuroimaging. Neuroimaging plays a pivotal role in either providing the final diagnosis, narrowing the differential diagnosis, or planning targeted further workup. In this review, we will focus on the most common form of ataxia in childhood, cerebellar ataxia (CA). We will discuss and summarize the neuroimaging findings of either the most common or the most important causes of CA in childhood or present causes of pediatric CA with pathognomonic findings on MRI. The various pediatric CAs will be categorized and presented according to (a) the cause of ataxia (acquired/disruptive vs. inherited/genetic) and (b) the temporal evolution of symptoms (acute/subacute, chronic, progressive, nonprogressive, and recurrent). In addition, several illustrative cases with their key imaging findings will be presented., (© 2022 American Society of Neuroimaging.)

Tinnitus is defined as the perception of sound without an external source and can be categorized as either pulsatile or nonpulsatile (ie, continuous). A variety of etiologies have been reported to cause pediatric tinnitus, many with long-lasting implications due to hearing and concentration impairments. Therefore, imaging can be an essential part of the accurate and timely diagnosis of treatable etiologies. We describe neuroimaging findings in different etiologies of pediatric tinnitus. Etiologies of pulsatile tinnitus are frequently vascular in nature and include vascular loops, congenital vascular anomalies or variants, high riding jugular bulbs with or without a jugular bulb diverticulum, idiopathic intracranial hypertension, aneurysms, internal auditory canal hemangiomas, and petrous apex cephaloceles. Etiologies of continuous tinnitus frequently affect the middle/inner ear structures and include vestibular schwannomas, cholesteatomas, trauma, Chiari malformations, and labyrinthitis ossificans. CT and MR are often complementary modalities: CT is better suited to evaluate the integrity of the temporal osseous structures and MR is better suited to evaluate the vestibulocochlear nerve and to assess for the presence of any masses or malformations. Prompt diagnosis of the etiology of tinnitus in pediatric patients is important to avoid any potential long-term developmental impairments. In the approach to pediatric tinnitus, categorizing the symptoms as either pulsatile versus nonpulsatile and then being aware of the possible causes and imaging findings of either can assist both the clinician and the radiologist in making an expeditious diagnosis., (© 2022 American Society of Neuroimaging.)

Objectives: To characterize a suggestive prenatal imaging pattern of Aicardi syndrome using ultrasound and MR imaging., Methods: Based on a retrospective international series of Aicardi syndrome cases from tertiary centers encountered over a 20-year period (2000-2020), we investigated the frequencies of the imaging features in order to characterize an imaging pattern highly suggestive of the diagnosis., Results: Among 20 cases included, arachnoid cysts associated with a distortion of the interhemispheric fissure were constantly encountered associated with complete or partial agenesis of the corpus callosum (19/20, 95%). This triad in the presence of other CNS disorganization, such as polymicrogyria (16/17, 94%), heterotopias (15/17, 88%), ventriculomegaly (14/20, 70%), cerebral asymmetry [14/20, 70%]) and less frequently extra-CNS anomaly (ocular anomalies [7/11, 64%], costal/vertebral segmentation defect [4/20, 20%]) represent a highly suggestive pattern of Aicardi syndrome in a female patient., Conclusion: Despite absence of genetic test to confirm prenatal diagnosis of AS, this combination of CNS and extra-CNS fetal findings allows delineation of a characteristic imaging pattern of AS, especially when facing dysgenesis of the corpus callosum., (© 2022 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.)

Mitochondrial disorders represent a diverse and complex group of entities typified by defective energy metabolism. The mitochondrial oxidative phosphorylation system is typically impaired, which is the predominant source of energy production. Because mitochondria are present in nearly all organs, multiple systems may be affected including the central nervous system, skeletal muscles, kidneys, and liver. In particular, those organs that are metabolically active with high energy demands are explicitly vulnerable. Initial diagnostic work up relies on a detailed evaluation of clinical symptoms including physical examination as well as a comprehensive review of the evolution of symptoms over time, relation to possible "triggering" events (eg, fever, infection), blood workup, and family history. High-end neuroimaging plays a pivotal role in establishing diagnosis, narrowing differential diagnosis, monitoring disease progression, and predicting prognosis. The pattern and characteristics of the neuroimaging findings are often highly suggestive of a mitochondrial disorder; unfortunately, in many cases the wide variability of involved metabolic processes prevents a more specific subclassification. Consequently, additional diagnostic steps including muscle biopsy, metabolic workup, and genetic tests are necessary. In the current manuscript, basic concepts of energy production, genetics, and inheritance patterns are reviewed. In addition, the imaging findings of several illustrative mitochondrial disorders are presented to familiarize the involved physicians with pediatric mitochondrial disorders. In addition, the significance of spinal cord imaging and the value of "reversed image-based discovery" for the recognition and correct (re-)classification of mitochondrial disorders is discussed., (© 2022 American Society of Neuroimaging.)

Objective: To determine the impact of the lesion type (cystic [myelomeningocele] or flat [myeloschisis]) on the fetal motor function (MF) in cases candidates for prenatal open neural tube defect (ONTD) repair., Methods: Retrospective cohort study of patients with ONTD who underwent prenatal repair at a single institution between 2011 and 2019. The lesion type and the measurements of the length and width of the lesions to calculate the surface of the ellipsoid lesion were performed using MR scans. Prenatal MF of the lower extremities was evaluated by ultrasound following a metameric distribution at the time of referral. Intact MF was defined as the observation of plantar flexion of the ankle. Logistic regression was performed to determine the predictive value of the type of lesion for having an intact MF at the time of referral., Results: 103 patients were included at 22.9 (19-25.4) weeks; 65% had cystic and 35% had flat lesions. At the time of referral, there was a higher proportion of cases with an intact MF in the presence of flat lesions (34/36; 94.4%) as compared to cystic lesion (48/67; 71.6%, p < 0.01). When adjusting for gestational age and anatomical level of the lesion, flat ONTD were 3.1 times more likely to be associated by intact motor function (CI%95 [2.1-4.6], p < 0.01) at the time of referral., Conclusion: Cystic ONTD are more likely to be associated with impaired MF at mid-gestation in candidates for prenatal ONTD repair., (© 2021 John Wiley & Sons Ltd.)

Prenatal ultrasound (US) is the first prenatal imaging tool for screening and evaluation of posterior fossa malformations since it is noninvasive, widely available, and safe for both mother and child. Fetal MRI is a widely used secondary technique to confirm, correct, or complement questionable US findings and plays an essential role in evaluating fetuses with suspected US findings and /or positive family history. The main sequences of fetal MRI consist of T2-weighted (T2w) ultrafast, single-shot sequences. Axial, coronal, and sagittal images are typically acquired allowing for a detailed evaluation of the posterior fossa contents. Also, various complimentary sequences, such as T1w, T2*w gradient sequences, or advanced techniques, including diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy, may provide additional information based on the studied malformation. Inclusion of these techniques should be done with careful risk-benefit analysis. The use of fetal MRI also aims to evaluate for associated anomalies. In addition, prenatal diagnosis of posterior fossa malformations is still a challenge but advances in knowledge in human developmental anatomy, genetic, and imaging recognition patterns have enabled us to shed some light on prognostic information that will help with the counseling of families. Finally, high-resolution late third trimester fetal MRI offers a safe alternative to early postnatal MR imaging, basically taking advantage of the uterine environment as a kind of "maternal incubator." Our goal is to discuss the spectrum of prenatal posterior fossa pathologies that can be studied by fetal MRI and their key neuroimaging features., (© 2021 American Society of Neuroimaging.)

Background and Purpose: Pediatric nasopharyngeal carcinoma (NPC) is a rare epithelial origin tumor associated with undifferentiated histology, Epstein-Barr virus (EBV) infection, and genetic risk factors. Childhood NPC is usually clinically silent, often presenting with advanced locoregional compromise, including skull base invasion and cervical lymphadenopathy, and has a better prognosis than adult NPC. This article describes computed tomography (CT) and magnetic resonance imaging (MRI) features in a cohort of 28 pediatric NPC patients., Methods: A retrospective review was performed among children with histopathology proven NPC diagnoses between 1996 and 2019 for this study. The electronic medical records were reviewed to determine demographics, EBV serology, and World Health Organization (WHO) type. Nasopharyngeal CT and/or MRI at presentation for tumor spread as well as density and/or intensity, lymphadenopathy, postcontrast enhancement and diffusion characteristics before treatment were evaluated., Results: Twenty-eight patients (21 males, 7 females) were included. The mean patient age at diagnosis was 13.3 (range 7 to 17) years. EBV was positive in 71.4% of patients. The majority of patients (78.6%) had a WHO type III tumor, unilateral fossa of Rosenmuller involvement (71.4%). Neuroimaging features were CT isodensity, T1-isointensity, T2-hyperintensity, and heterogeneous postcontrast enhancement for all patients (100%) and restricted diffusion (90%)., Conclusions: Although uncommon in pediatric patients, NPC should be in the differential diagnosis of adolescents presenting with a nasopharyngeal mass. Recognizing key imaging characteristics is helpful in the diagnosis of NPC., (© 2020 American Society of Neuroimaging.)

Paranasal sinuses (PNS) infections are common in children. They may cause common and well-known complications, but also, unusual and potentially devastating complications. Diagnosing PNS infections and complications in children requires knowledge of the unique anatomy of the nasal cavity and the PNS. In fetal life, nasal mucosa evaginations into the lateral nasal walls initiate the development of the PNS. The PNS continue to develop after birth and complete their maturation and pneumatization at different ages during childhood which makes the pattern of PNS infections determined by patient age. Complications are caused by direct spread of the infection to the orbit, face, intracranial or osseous structures or hematogenous spread of the infection to the intracranial structures. Emergent imaging studies are often necessary in the evaluation of the complications in pediatric patients when the symptoms persist for 10 days and/or if there is evidence of intracranial or orbital complications. In addition, immunocompromised children are especially vulnerable to developing unusual complications. Computed tomography (CT) is excellent for determining whether there is intraorbital extension of PNS disease. However, when the infection approaches the orbital apex, a magnetic resonance imaging (MRI) study with contrast is necessary to assess spread into the cavernous sinus and the intracranial compartment. The goal of this manuscript is to review and characterize imaging findings of PNS infections using CT and MRI allowing determination of the extent of PNS infections and their common and unusual complications in children. In addition, a summary of the development of the normal PNS is provided., (© 2020 American Society of Neuroimaging.)

Background and Purpose: The molecular groups WNT activated (WNT), Sonic hedgehog activated (SHH), group 3, and group 4 are biologically and clinically distinct forms of medulloblastoma. We evaluated apparent diffusion coefficient (ADC) values' utility in differentiating/predicting medulloblastoma groups at the initial diagnostic imaging evaluation and prior to surgery., Methods: We retrospectively measured the ADC values of the enhancing, solid portion of the tumor (EST) and of the whole tumor (WT) and performed Kruskal-Wallis testing to compare the absolute tumor ADC values and cerebellar and thalamic ratios of three medulloblastoma groups (WNT, SHH, and group 3/group 4 combined)., Results: Ninety-three children (65 males) were included. Fifty-seven children had group 3/group 4, 27 had SHH, and 9 had WNT medulloblastomas. The median absolute ADC values in the EST and WT were .719 × 10 -3 and .864 × 10 -3 mm 2 /s for group 3/group 4; .660 × 10 -3 and .965 × 10 -3 mm 2 /s for SHH; and .594 × 10 -3 and .728 × 10 -3 mm 2 /s for WNT medulloblastomas (P = .02 and .13). The median ratio of ADC values in the EST or the WT to normal cerebellar tissue was highest for group 3/group 4 and lowest for WNT medulloblastomas (P = .03 and .09), with similar results in pairwise comparisons of the corresponding thalamic ADC values (P = .02 and .06)., Conclusion: ADC analysis of a tumor's contrast-enhancing solid portion may aid preoperative molecular classification/prediction of pediatric medulloblastomas and may facilitate optimal surgical treatment planning, reducing surgery-induced morbidity., (© 2020 American Society of Neuroimaging.)

Background and Purpose: Posterior fossa syndrome (PFS), characterized by loss of language and other neurological impairments within the immediate postoperative period, occurs in approximately 25% of children who undergo surgical resection of posterior fossa tumors. Diffusion tensor imaging connectomics offer promise for elucidation of pathway-level disruption in neural connectivity of patients with this disorder. We aim to determine differences in pre- and postoperative connectomics between children with PFS and children with mild or no language deficit after surgery., Methods: Pre- and postoperative diffusion tensor imaging connectomics were applied and compared among patients with PFS, mild deficits, and intact language., Results: A total of 35 patients were included in the study. Twenty-three patients with preoperative data and 24 patients with postoperative data were included in the analysis. Mean ages: PFS-8.5 years, mild-3.1 years, intact language-9.4 years (P = .02). Diagnoses included medulloblastoma (44.1%), pilocytic astrocytoma (28.6%), ependymoma (8.6%), other (11.4%), and unknown (8.6%). Five (21.7%) patients had PFS, 4 (17.4%) had mild deficits, and 14 (60.9%) had intact language. The assortativity coefficient was significantly higher in patients with PFS when compared to patients with mild deficits (P = .023). In the connectometry analyses, decreased connectivity was found involving the corpus callosum, right corticothalamic pathway, and right corticostriatal pathway in patients with PFS when compared to patients with intact language., Conclusions: Our findings revealed significant differences in preoperative neural connectivity involving the corticothalamic and other pathways among children who did, versus who did not, develop PFS postoperatively. Diffusion tensor imaging connectomics offers a unique opportunity to study the effect of the posterior fossa tumors on cerebello-cerebral networks and provide new insights into the mechanism of the structural plasticity/reorganization after surgery., (© 2020 by the American Society of Neuroimaging.)

Trauma is the most common cause of death and significant morbidity in childhood; abusive head trauma (AHT) is a prominent cause of significant morbidity and mortality in children younger than 2 years old. Correctly diagnosing AHT is challenging both clinically and radiologically. The primary diagnostic challenges are that the abused children are usually too young to provide an adequate history, perpetrators are unlikely to provide truthful account of trauma, and clinicians may be biased in their assessment of potentially abused children. The main radiological challenge is that there is no single imaging finding that is independently specific for or diagnostic of AHT. The radiological evaluation should be based on the multiplicity and severity of findings and an inconsistency with the provided mechanism of trauma. While the most common neuroimaging finding in AHT is subdural hemorrhage, other less well-known magnetic resonance imaging (MRI) findings such as the "lollipop sign" or "tadpole sign," parenchymal or cortical lacerations, subpial hemorrhage, cranio-cervical junction injuries including retroclival hematomas, as well as diffuse hypoxic brain injury have been identified and described in the recent literature. While AHT is ultimately a clinical diagnosis combining history, exam, and neuroimaging, familiarity with the typical as well as the less-well known MRI findings will improve recognition of AHT by radiologists., (© 2019 by the American Society of Neuroimaging.)

Background: Hypoxic-ischemic injury (HII) is a major cause of neonatal death and neurodevelopmental disability. Head ultrasounds (HUS) in neonates with HII often show enhanced gray/white matter differentiation. We assessed the significance of this finding in predicting white matter structural integrity measured by diffusion tensor imaging (DTI) in neonates with HII., Methods: We performed a quantitative region of interest-based analysis of white and gray matter echogenicity within the cingulate gyrus on pre- and posthypothermia HUS. We also completed a quantitative analysis of fractional anisotropy (FA) and mean (MD), axial (AD), and radial (RD) diffusivity within the bilateral anterior and posterior centrum semiovale (CSO) on posthypothermia brain magnetic resonance imaging. For HUS studies, we calculated a white-to-gray matter echogenicity ratio (WGR) and subsequently correlated it to DTI measurements., Results: Forty-two term neonates with HII who underwent hypothermia therapy were included. Significant correlation was found between prehypothermia WGR and MD, AD, and RD values in the left anterior CSO (r = .38-.40, P = .02). Prehypothermia WGR also correlated with the following: MD and RD in the right anterior CSO (r = .35-.36, P = .04), MD and AD in the right posterior CSO (r = .32-.45, P = .008-.03), and AD in the left posterior CSO (r = .47, P = .005). No significant correlation was found either between prehypothermia WGR and FA values in the bilateral anterior and posterior CSO or between posthypothermia WGR and all DTI scalars in the bilateral anterior and posterior CSO., Conclusions: Prehypothermia HUS WGR may predict posthypothermia white matter structural integrity and is potentially an early and easily obtainable biomarker of severity in neonatal HII., (© 2019 by the American Society of Neuroimaging.)

The embryologic development of the spinal cord is a remarkably complex process. Spinal abnormalities can occur in isolation or be part of a clinical syndrome commonly summarized as spinal dysraphism. Proper evaluation of spinal malformations with imaging is required for early diagnosis prior to counseling and selection of postnatal treatment options. The preferred imaging modality of the spine in newborns up to 3 months of age are ultrasound (US) and magnetic resonance imaging (MRI). The diagnostic workup should preferably start with the safe, minimal invasive (no need for sedation), cost-effective, and bedside US as a screening procedure. On the other hand, need for sedation, thermal instability of infants, and high cost make the use of spinal MRI impracticable for screening purposes. US is also a well-established imaging modality to investigate the spinal cord and canal during pregnancy. It is critical to follow a strict protocol in an attempt to precisely identify all imaging findings, one should be familiar with the normal ultrasonographic appearance of bony and soft tissue structures in the various planes and one should be able to correlate the abnormal findings with spinal cord embryology as it aids in identifying the etiology. US should be considered as a first-line imaging for neonates suspected of spinal anomalies. In this article, we discuss up-to-date US technique of the spine, the most frequently encountered neonatal spinal malformations seen with US and correlate these findings with the relevant embryologic processes., (© 2019 by the American Society of Neuroimaging.)

Purpose: Noninvasive measurement of cerebral venous oxygenation (Y v ) in neonates is important in the assessment of brain oxygen extraction and consumption, and may be useful in characterizing brain development and neonatal brain diseases. This study aims to develop a rapid method for vessel-specific measurement of Y v in neonates., Methods: We developed a pulse sequence, named accelerated T 2 -relaxation-under-phase-contrast (aTRUPC), which consists of velocity-encoding phase-contrast module to isolate pure blood signal, flow-insensitive T 2 -preparation to quantify blood T 2 , and turbo-field-echo (TFE) scheme for rapid image acquisition, which is critical for neonatal MRI. A series of studies were conducted. First, the pulse sequence was optimized in terms of TFE factor, velocity encoding (VENC), and slice thickness for best sensitivity. Second, to account for the influence of TFE acquisition on T 2 quantification, simulation and experiments were conducted to establish the relationship between TFE-T 2 and standard T 2 . Finally, the complete aTRUPC sequence was applied on a group of healthy neonates and normative Y v values were determined., Results: Optimal parameters of aTRUPC in neonates were found to be a TFE factor of 15, VENC of 5 cm/s, and slice thickness of 10 mm. The TFE-T 2 was on average 3.9% lower than standard T 2 . These two measures were strongly correlated (R 2 = 0.86); thus their difference can be accounted for by a correction equation, T 2,standard = 1.2002 × T 2,TFE - 10.6276. Neonatal Y v values in veins draining cortical brain and those draining central brain were 64.8 ± 2.9% and 70.2 ± 3.3%, respectively, with a significant difference (P =.02)., Conclusion: The aTRUPC MRI has the potential to provide vessel-specific quantification of cerebral Y v in neonates., (© 2019 International Society for Magnetic Resonance in Medicine.)

There is increasing interest in applying physiological MRI in neonates, based on the premise that physiological parameters may provide an early biomarker of neonatal brain health and injury. Two commonly used techniques are oxygen extraction fraction (OEF) measurement using T 2 -relaxation-under-spin-tagging (TRUST) MRI and cerebral blood flow measurement using phase-contrast (PC) quantitative flow MRI, which collectively provide an assessment of the brain's oxygen consumption. However, prior research has only demonstrated proof of principle of these methods in neonates, without characterization or benchmarking of the techniques. This is because available time is limited in neonatal subjects, especially when scans are performed as add-ons to clinical scans (typically less than 5 min). The work presented aims to examine the TRUST and PC MRI sequences systematically in normal neonates, through research-dedicated scan sessions. A series of characterization and optimization studies were conducted in a total of 26 radiographically normal neonates on 3 T systems. Our results show that TRUST MRI at the superior sagittal sinus (SSS) provides an OEF measurement equivalent to that at the internal jugular vein (r = 0.80, n = 10), yet with shorter scan time. Lower resolution provided better precision in the TRUST measurement (p = 0.001, n = 9). Therefore, the preferred OEF measurement is to apply TRUST MRI at the SSS using a spatial resolution of 2.5 mm. For PC MRI, our results showed that non-gated PC MRI yielded blood flow measurements comparable to those from the more time-consuming gated approach in neonates (r = 0.89, n = 7). It was also found that blood flow could be overestimated by 18% when imaging resolution is larger than 0.3 mm (n = 7). Therefore, non-gated PC MRI with a spatial resolution of 0.3 mm is recommended for neonatal applications. In conclusion, this study verifies consistency of neonatal brain oxygenation and flow measurements across acquisition schemes and points to optimal strategies in parameter selection when using these sequences., (© 2019 John Wiley & Sons, Ltd.)

Background and Purpose: Tuberous sclerosis complex (TSC) is a rare, genetic disease that is associated with multiple manifestations including epilepsy and autism. Self-injurious behaviors (SIBs) also occur in a subset of patients. This study used diffusion tensor imaging (DTI) in children with TSC for quantitative and volumetric analysis of brain regions that have been associated with SIB in other genetic conditions., Methods: We used DTI to compare 6 children with TSC-associated SIB and 10 children with TSC without SIB. Atlas-based analysis of DTI data and calculation of number of voxels; fractional anisotropy (FA); and mean, axial, and radial diffusivity were performed for multiple regions; DTI measures were summarized using medians and interquartile ranges and were compared using Wilcoxon rank sum tests and false discovery rates (FDRs)., Results: Analysis showed that children with TSC and SIB had reduced numbers of voxels (median) in the bilateral globus pallidus (right: 218 vs. 260, P = .008, FDR = .18; left: 222 vs. 274, P = .002, FDR = .12) and caudate nucleus (right: 712 vs. 896, P = .01, FDR = .26; left: 702 vs. 921, P = .03, FDR = .44) and reduced FA in the bilateral globus pallidus (right: .233 vs. .272, P = .003, FDR = .12; left: .223 vs. .247, P = .004, FDR = .12) and left caudate nucleus (.162 vs. .186, P = .03, FDR = .39) versus children without SIB. No other statistically significant differences were found., Conclusions: These data support a correlation between lower volumes of the globus pallidus and caudate with SIB in children with TSC., (© 2019 The Authors Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.)

Background and Purpose: Neonatal hypoxic-ischemic injury of the brain and resultant encephalopathy (HIE) leads to major developmental impairments by school age. Conventional/anatomical MRI often fails to detect hippocampal injury in mild cases. We hypothesize that diffusion tensor imaging (DTI) has greater sensitivity for identifying subtle hippocampal injury., Methods: We retrospectively analyzed DTI data collected from a cohort of neonates with HIE and controls. Conventional MRI sequences were classified qualitatively according to severity using a modified Barkovich scale. Using multivariate linear regression, we compared hippocampal DTI scalars of HIE patients and controls. Spearman correlation was used to test the association of DTI scalars in the hippocampal and thalamic regions. A multiple regression analysis tested the association of the DTI scalars with short-term outcomes., Results: Fifty-five neonates with HIE (42% males) and 13 controls (54% males) were included. Hippocampal DTI scalars were similar between HIE and control groups, even when restricting the HIE group to those with moderate-to-severe injury (8 subjects). DTI scalars of the thalamus were significantly lower in the moderate-to-severely affected patients compared to controls (right fractional anisotropy [FA] .148 vs. .182, P = .01; left FA .147 vs. .181, P = .03). Hippocampal and thalamic DTI scalars were correlated (P < .001). Hippocampal DTI scalars were not associated with short-term outcomes., Conclusions: Quantitative DTI analysis of the hippocampus in neonates following HIE is a feasible technique to examine neuronal injury. Although DTI scalars were useful in identifying thalamic injury in our cohort, hippocampal DTI analysis did not provide additional information regarding hippocampal injury following HIE., (© 2018 by the American Society of Neuroimaging.)

There are multiple causes of neurotoxicity in children including medications, extrinsic toxins and insults, illicit drugs, built up of toxic metabolites due to genetic or acquired disorders, and metabolic abnormalities. The review is centered on causes of neurotoxicity affecting the pediatric brain and producing typical and easily recognized imaging manifestations. Early identification of common and less common imaging findings may point toward the correct direction, and may facilitate early diagnosis and institution of appropriate treatment to reverse or at least limit the injury to the developing brain. Two common imaging patterns of neurotoxicity in children are the posterior reversible encephalopathy syndrome and acute toxic leukoencephalopathy that are usually related to chemotherapy and immunosuppression for common pediatric malignancies. Another well-described imaging pattern of injury in children involves reversible splenial lesions with or without associated white matter abnormalities. Multiple additional extrinsic causes of neurotoxicity are presented including radiation and chemoradiation, various medications and treatment regimens, poisoning, illicit drug use or accidental exposure, and the respective characteristic neuroimaging findings are highlighted. Intrinsic neurotoxicity may occur in the setting of inborn errors of metabolism or acquired progressive organ failure leading to build up of toxic metabolites. Additional intrinsic causes of neurotoxicity include metabolic derangements and characteristic imaging findings in all instances are reviewed. The goal of the article is to enhance familiarity of neurologists and neuroradiologists with the imaging appearance of common and less common toxic insults to the pediatric brain., (© 2018 by the American Society of Neuroimaging.)

Background and Purpose: Hypoxic-ischemic injuries (HIIs) are a scarcely investigated but important cause of morbidity and mortality in children who suffered abusive head trauma (AHT). The purpose of this study is to determine: (a) prevalence, types, and clinical relevance of cytotoxic edema compatible with HII in nonpenetrating AHT, (b) their relationship to other classic neuroimaging findings of AHT, and (c) their correlation with clinical outcomes., Methods: Diffusion-weighted imaging sequences of magnetic resonance imagings performed on children under 5 years diagnosed with AHT were reviewed to detect the most common patterns of acute parenchymal damage. Patterns of cytotoxic edema were described, and HII-compatible ones divided in subtypes. Correlation between HII, fractures, and subdural hemorrhages (SDHs) and with clinical outcomes was determined using imaging and available follow-up data., Results: Out of 57 patients, 36.8% showed lesions compatible with HII. A predominantly asymmetric cortical distribution was observed in 66.7% of cases, while 33.3% had diffused both cortical and deep gray/white matter distribution injury. Traumatic axonal injuries and focal contusions were less common. There was no significant correlation between the presence of SDH (P = .6) or skull fractures (P = .53) and HII. HII was the most severe form of parenchymal damage in terms of in-hospital mortality and morbidity at follow-up., Conclusions: HII is the most common type of parenchymal damage in children victim of AHT, being present in 1/3 of patients with this condition, and correlates with more severe outcomes. Its presence is independent from other classic traumatic findings such as SDH and fractures., (© 2018 by the American Society of Neuroimaging.)

Background and Purpose: Persistent hyperextension of the fetal craniocervical junction or neck is one of several fetal positions commonly observed on prenatal imaging. Underlying fetal structural etiologies such as fetal neck masses and iniencephaly can be detected as causes of hyperextension. Caesarean delivery is considered in cases of vaginal delivery or obstructed labor for fear of cervical spinal cord injury. In this case series, we describe the prenatal magnetic resonance imaging (MRI) findings and their potential role in obstetric management and discuss postnatal outcomes in fetuses demonstrating prenatal imaging findings of persistent extreme hyperextension of the neck., Methods: A retrospective cohort of fetuses with extreme fetal neck hyperextension on prenatal ultrasound and subsequent MRI is described., Results: Persistent extreme neck hyperextension was demonstrated in four pregnancies. One patient showed resolution of head positioning prior to labor. In the other 3 patients, neck hyperextension persisted until labor. In these three pregnancies, caesarean section with early intubation was performed due to concern for airway compromise and cervical cord injury. An underlying structural neck abnormality with airway compromise was noted only in 1 patient (large venolymphatic malformation). No airway compromise, cervical spine, or spinal cord anomaly was identified in the remaining 3 patients. Noncervical fetal anomalies were detected only in 1 patient (arthogryposis multiplex and clubfoot deformities). In patients with no structural neck abnormality, early extubation was performed shortly following labor., Conclusions: Detailed, high-resolution fetal MRI may serve as a valuable secondary imaging modality for clinical decision making regarding management of pregnancy, in utero therapy, mode of delivery, and postnatal care., (Copyright © 2018 by the American Society of Neuroimaging.)

Recent technical advances in neurosonography continue broadening the diagnostic utility, sensitivity, and specificity of ultrasound for detecting intracranial abnormalities bed side. The clinical and functional applications of neurosonography have significantly expanded since the 1980s when transcranial Doppler sonography first allowed anatomic and hemodynamic delineation of the intracranial vessels through the thin temporal skull. In the past few years, contrast-enhanced ultrasonography, elastography, 3D/4D reconstruction tools, and high-resolution microvessel imaging techniques have further enhanced the diagnostic significance of neurosonography. Given these advances, a thorough familiarity with these new techniques and devices is crucial for a successful clinical application allowing improved patient care. It is essential that future neurosonography studies compare these advanced techniques against the current "gold standard" computed tomography and magnetic resonance imaging to assure the accuracy of their diagnostic potential. This review will provide a comprehensive update on currently available advanced neurosonography techniques., (Copyright © 2017 by the American Society of Neuroimaging.)

A wide variety of conditions may involve the splenium of the corpus callosum on magnetic resonance imaging in children. A single cause may present with different patterns of splenial involvement, and multiple diseases may have similar imaging findings. Keeping this limitation in mind, the goal of this text is to assist in the diagnostic process of pediatric neurological diseases that are characterized by prominent involvement of the splenium of the corpus callosum on imaging. The various pathologies will be reviewed and categorized based on etiology, reversibility, and pattern of additional or associated findings. Transient splenial lesions in children are an uncommon radiologic finding of unknown etiology in a long list of conditions that may present with altered consciousness, and it usually carries a favorable prognosis. The discussion continues with the presentation of diseases inflicting irreversible damage on the splenium. Familiarity with the various causes implicated in splenial injury may assist in the formulation of differential diagnosis in the appropriate clinical setting using an easily recognizable imaging finding., (Copyright © 2017 by the American Society of Neuroimaging.)

Neonates presenting with neurologic symptoms require rapid, noninvasive imaging with high spatial resolution and tissue contrast. Magnetic resonance imaging (MRI) is currently the most sensitive and specific imaging modality for evaluation of neurological pathology. This modality does come with several challenges in the neonatal population, namely, the need to transport a possibly critically sick neonate to the MRI suite and the necessity of the neonate to remain still for a significant length of time, occasionally requiring sedation. Cranial ultrasound has provided radiologists and clinicians with an invaluable imaging modality that allows of rapid, bedside point of care evaluation without ionizing radiation. The major drawback of cranial ultrasound is its lower sensitivity and specificity for subtle/early lesions. Contrast-enhanced ultrasound (CEUS) and elastography have the potential to improve sensitivity and specificity for a variety of neuropathology but also expand the indications for cranial ultrasound. Goal of this paper is to present and discuss CEUS and elastography for neonatal brain imaging., (Copyright © 2017 by the American Society of Neuroimaging.)

Parturitional injuries refer to injuries sustained during and secondary to fetal delivery. The skull, brain, and head and neck regions are frequently involved. Accurate differentiation and classification of the various injuries is essential for treatment, prognosis, and parental counseling. In this review, we discuss the various "bumps and lumps" that maybe encountered along the neonatal skull as well as the most frequent calvarial and intracranial parturitional injuries. In addition, a short discussion of the most common head and neck, facial, and spinal lesions is included. Various mimickers and risk factors are also presented., (Copyright © 2014 by the American Society of Neuroimaging.)