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Magnetic resonance imaging perfusion (MRP) techniques can improve the selection of acute ischemic stroke patients for treatment by estimating the salvageable area of decreased perfusion, that is, penumbra. Arterial spin labeling (ASL) is a noncontrast MRP technique that is used to assess cerebral blood flow without the use of intravenous gadolinium contrast. Thus, ASL is of particular interest in stroke imaging. This article will review clinical applications of ASL in stroke such as assessment of the core infarct and penumbra, localization of the vascular occlusion, and collateral status. Given the nonspecific symptoms that patients can present with, differentiating between stroke and a stroke mimic is a diagnostic dilemma. ASL not only helps in differentiating stroke from stroke mimic but also can be used to specify the exact mimic when used in conjunction with the symptomatology and structural imaging. In addition to a case-based overview of clinical applications of the ASL in stroke and stroke mimics in this article, the more commonly used ASL labeling techniques as well as emerging ASL techniques, future developments, and limitations will be reviewed.

Lymphatic anomalies comprise a spectrum of disorders ranging from common localized microcystic and macrocystic lymphatic malformations (LMs) to rare complex lymphatic anomalies, including generalized lymphatic anomaly, Kaposiform lymph-angiomatosis, central conducting lymphatic anomaly, and Gorham-Stout disease. Imaging diagnosis of cystic LMs is generally straightforward, but complex lymphatic anomalies, particularly those with multiorgan involvement or diffuse disease, may be more challenging to diagnose. Complex lymphatic anomalies are rare but associated with high morbidity. Imaging plays an important role in their diagnosis, and radiologists may be the first clinicians to suggest the diagnosis. Furthermore, radiologists are regularly involved in management given the frequent need for image-guided interventions. For these reasons, it is crucial for radiologists to be familiar with the spectrum of entities comprising complex lymphatic anomalies and their typical imaging findings. In this article, we review the imaging findings of lymphatic anomalies, including LMs and complex lymphatic anomalies. We discuss characteristic imaging findings, multimodality imaging techniques used for evaluation, pearls and pitfalls in diagnosis, and potential complications. We also review recently discovered genetic changes underlying lymphatic anomaly development and the advent of new molecularly targeted therapies.

BACKGROUND Disruption of brain oxygen delivery and consumption after hypoxic-ischemic injury contributes to neonatal mortality and neurological impairment. Measuring cerebral hemodynamic parameters, including cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2 ), is clinically important. PURPOSE Phase-contrast (PC), velocity-selective arterial spin labeling (VSASL), and T2 -relaxation-under-phase-contrast (TRUPC) are magnetic resonance imaging (MRI) techniques that have shown promising results in assessing cerebral hemodynamics in humans. We aimed to test their feasibility in quantifying CBF, OEF, and CMRO2 in piglets. STUDY TYPE Prospective. ANIMAL MODEL Ten neonatal piglets subacutely recovered from global hypoxia-ischemia (N = 2), excitotoxic brain injury (N = 6), or sham procedure (N = 2). FIELD STRENGTH/SEQUENCE VSASL, TRUPC, and PC MRI acquired at 3.0 T. ASSESSMENT Regional CBF was measured by VSASL. Global CBF was quantified by both PC and VSASL. TRUPC assessed OEF at the superior sagittal sinus (SSS) and internal cerebral veins (ICVs). CMRO2 was calculated from global CBF and SSS-derived OEF. End-tidal carbon dioxide (EtCO2 ) levels of the piglets were also measured. Brain damage was assessed in tissue sections postmortem by counting damaged neurons. STATISTICAL TESTS Spearman correlations were performed to evaluate associations among CBF (by PC or VSASL), OEF, CMRO2 , EtCO2 , and the pathological neuron counts. Paired t-test was used to compare OEF at SSS with OEF at ICV. RESULTS Global CBF was 32.1 ± 14.9 mL/100 g/minute and 30.9 ± 8.3 mL/100 g/minute for PC and VSASL, respectively, showing a significant correlation (r = 0.82, P

BACKGROUND: Diffusion MRI is routinely used to evaluate brain injury in neonatal encephalopathy. Though abnormal mean diffusivity (MD) is often attributed to cytotoxic edema, the specific contribution from neuronal pathology is unclear. PURPOSE: To determine whether MD from high-resolution diffusion tensor imaging (DTI) can detect variable degrees of neuronal degeneration and pathology in piglets with brain injury induced by excitotoxicity or global hypoxia-ischemia (HI) with or without overt infarction. STUDY TYPE: Prospective. ANIMAL MODEL: Excitotoxic brain injury was induced in 6 neonatal piglets by intrastriatal stereotaxic injection of the glutamate receptor agonist quinolinic acid (QA). Three piglets underwent global HI or sham procedure. Piglets recovered for 20–96 hours before undergoing MRI (n=9). FIELD STRENGTH/SEQUENCE: 3.0T MRI with DTI, T(1)- and T(2)-weighted imaging. ASSESSMENT: MD, fractional anisotropy (FA), and qualitative T(2) injury were measured in putamen and caudate. The cell bodies of normal neurons, degenerating neurons (excitotoxic necrosis, ischemic necrosis, or necrosis-apoptosis cell death continuum), and injured neurons with equivocal degeneration were counted by histopathology. STATISTICAL TESTS: Spearman correlations were used to compare MD and FA to normal, degenerating, and injured neurons. T(2) injury and neuron counts were evaluated by descriptive analysis. RESULTS: The QA insult generated titratable levels of neuronal pathology. In QA, HI, and sham piglets, lower MD correlated with higher ratios of degenerating-to-total neurons (p0.99). Neuron counts were not related to FA (p>0.30) or to qualitative injury from T(2)-weighted MRI. DATA CONCLUSION: MD is more accurate than FA for detecting neuronal degeneration and loss during acute recovery from neonatal excitotoxic and HI brain injury. MD does not reliably detect non-fulminant, nascent, and potentially reversible neuronal injury.

BACKGROUND Blood-brain barrier (BBB) disruption may lead to endothelium dysfunction and inflammation in sickle cell disease (SCD). However, abnormalities of BBB in SCD, especially in pediatric patients for whom contrast agent administration less than optimal, have not been fully characterized. PURPOSE To examine BBB permeability to water in a group of pediatric SCD participants using a non-invasive magnetic resonance imaging technique. We hypothesized that SCD participants will have increased BBB permeability. STUDY TYPE Prospective cross-sectional. POPULATION Twenty-six pediatric participants (10 ± 1 years, 15F/11M) were enrolled, including 21 SCD participants and 5 sickle cell trait (SCT) participants, who were siblings of SCD patients. FIELD STRENGTH/SEQUENCE 3 T. Water extraction with phase-contrast arterial spin tagging with echo-planer imaging, phase-contrast and T1 -weighted magnetization-prepared rapid acquisition of gradient echo. ASSESSMENT Water extraction fraction (E), BBB permeability-surface area product (PS), cerebral blood flow, hematological measures (hemoglobin, hematocrit, hemoglobin S), neuropsychological scores (including domains of intellectual ability, attention and executive function, academic achievement and adaptive function, and a composite score). Regions of interest were drawn by Z.L. (6 years of experience). STATISTICAL TESTS Wilcoxon rank sum test and chi-square test for group comparison of demographics. Multiple linear regression analysis of PS with diagnostic category (SCD or SCT), hematological measures, and neuropsychological scores. A two-tailed P value of 0.05 or less was considered statistically significant. RESULTS Compared with SCT participants, SCD participants had a significantly higher BBB permeability to water (SCD: 207.0 ± 33.3 mL/100 g/minute, SCT: 171.2 ± 27.2 mL/100 g/minute). SCD participants with typically more severe phenotypes also had a significantly leakier BBB than those with typically milder phenotypes (severe: 217.3 ± 31.7 mL/100 g/minute, mild: 193.3 ± 31.8 mL/100 g/minute). Furthermore, more severe BBB disruption was associated with worse hematological symptoms, including lower hemoglobin concentrations (β = -8.84, 95% confidence interval [CI] [-14.69, -3.00]), lower hematocrits (β = -2.96, 95% CI [-4.84, -1.08]), and higher hemoglobin S fraction (β = 0.77, 95% CI [0.014, 1.53]). DATA CONCLUSION These findings support a potential role for BBB dysfunction in SCD pathogenesis of ischemic injury. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 2.

Scoliosis is frequently encountered in childhood, with prevalence of 2%. The majority is idiopathic, without vertebral segmentation anomaly, dysraphism, neuromuscular abnormality, skeletal dysplasia, tumor, or infection. As a complement to clinical assessment, radiography is the primary imaging modality used to classify scoliosis and subsequently monitor its progression and response to treatment. MRI is utilized selectively to assess for neural axis abnormalities in those at higher risk, including those with congenital scoliosis, early onset idiopathic scoliosis, and adolescent idiopathic scoliosis with certain risk factors. CT, although not routinely employed in the initial evaluation of scoliosis, may have a select role in characterizing the bone anomalies of congenital scoliosis and in perioperative planning. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Choosing the appropriate imaging in children with accidental traumatic spine injuries can be challenging because the recommendations based on scientific evidence at this time differ from those applied in adults. This differentiation is due in part to differences in anatomy and physiology of the developing spine. This publication uses scientific evidence and a panel of pediatric experts to summarize best current imaging practices for children with accidental spine trauma. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Aim There is controversy regarding the diagnosis and classification of vascular anomalies (VA). As torso and extremities are the second most common body part for presentation of VAs, musculoskeletal (MSK) radiologists play a central role in VA classification. The purpose of this study was to evaluate the awareness and clinical use of the International Society for the Study of Vascular Anomalies (ISSVA) classification by MSK radiologists. Materials and Methods A Web-based survey was designed and electronically sent to Society of Skeletal Radiology (SSR) members, with 3 questions on demographics and 7 questions on ISSVA classification use and knowledge. The Z-test for binomial proportions is used to assess for statistical significance between subgroups. Results The response rate was 12% (130 of 1091), comprised of 64% (83 of 130) academic and 36% (47 of 130) nonacademic MSK radiologists. VAs accounted for only a small (0%-5%) proportion of clinical practice in the majority 92% (119 of 130). Only 17% (22 of 130) of MSK radiologists used the ISSVA classification in practice. Of all respondents, 74% (94 of 127) considered hemangioma a type of vascular malformation (VM). There was no significant difference in the response characteristics between academic and nonacademic radiologists. A greater proportion of MSK radiologists with >5 years’ experience provided responses that were discordant with the ISSVA classification compared with less experienced radiologists (0-5 years) in diagnosing hemangiomas in adult patients (P = 0.02), and using the presence of phleboliths to diagnose hemangiomas (P = 0.004). Conclusion Our survey results indicate a lack of familiarity with the ISSVA classification by the MSK radiology community.

OBJECTIVE. Subpial hemorrhages, typically seen in neonates, are rare but can harm the adjacent brain parenchyma. The purpose of this review is to summarize the anatomy and pathophysiology of subpial hemorrhage and highlight its characteristic neuro-imaging pattern. CONCLUSION. The distinctive neuroimaging pattern of subpial hemorrhage is best appreciated on brain MRI, which shows the morphology over the cortex and injury to adjacent cortex and subcortical white matter. These findings do not occur in subarachnoid and subdural hemorrhages. Recognizing the pattern of subpial hemorrhages should guide prognostic precision, prognostication, and counseling.

Sinusitis is common in children that usually resolves spontaneously. Imaging is not part of the standard of care for initial diagnosis, however may be necessary in cases with persistent or chronic sinusitis to guide surgical intervention, or to rule out intracranial and vascular complications of sinusitis. Computed tomography (CT) and magnetic resonance imaging (MRI) are the leading imaging modalities. In this article, appropriateness in use of imaging modalities are discussed under common/clinically relevant scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Headaches in children are not uncommon and have various causes. Proper neuroimaging of these children is very specific to the headache type. Care must be taken to choose and perform the most appropriate initial imaging examination in order to maximize the ability to properly determine the cause with minimum risk to the child. This evidence-based report discusses the different headache types in children and provides appropriate guidelines for imaging these children. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Vascular anomalies can occur anywhere in the body, and the majority present in the pediatric population. Accurate classification is essential for proper clinical evaluation, particularly because multidisciplinary care is often required. The International Society for the Study of Vascular Anomalies classification offers a comprehensive classification for all subspecialties. In this review article, we present a magnetic resonance imaging protocol with exemplary cases of the most common types of vascular anomalies in the pediatric trunk and extremities using the current International Society for the Study of Vascular Anomalies classification.

Sensitive, specific, and safe bedside evaluation of brain perfusion is key to the early diagnosis, treatment, and improved survival of neonates with hypoxic ischemic injury. Contrast-enhanced ultrasound (US) imaging is a novel imaging technique in which intravenously injected gas-filled microbubbles generate enhanced US echoes from an acoustic impedance mismatch. This article describes contrast-enhanced US imaging in 2 neonates with hypoxic ischemic injury and future directions on developing quantitative contrast-enhanced US techniques for improved characterization of perfusion abnormalities. The importance of studying the temporal evolution of brain perfusion in neonatal hypoxic ischemic injury is also highlighted.

PURPOSE: Non-invasive 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 5cm/s, and slice thickness of 10mm. 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=0.02). CONCLUSION: aTRUPC MRI has the potential to provide vessel-specific quantification of cerebral Y(v) in neonates.

Neck masses present as palpable lumps and bumps in children with acquired lesions more common than congenital ones. Assessment of the anatomical site of origin, signal, and contrast enhancement characteristics may help define the etiology of the lesions, eg, developmental, inflammatory, vascular, or neoplastic. The age of the patient along with detailed clinical history and physical exam findings are important element to narrow down the differential diagnosis. The correct final diagnosis is essential to guide treatment as well as the urgency of intervention. The objective of this review is to define the characteristic location, classic and differentiating imaging features of the most frequent congenital and acquired cervical lumps and bumps in the pediatric population.

The purpose of this article is to present illustrative cases highlighting the value of fetal MRI as a problem-solving tool in evaluating anomalies of the fetal chest, abdomen, and pelvis that are being evaluated for fetal therapy.Fetal MRI is an increasingly valuable noninvasive tool for evaluating fetal anomalies in the age of fetal therapy. Although ultrasound remains the primary diagnostic imaging modality, MRI can provide additional information to assist parental counseling and patient care.

Purpose To report clinical and radiographic outcomes of patients with venous malformations (VMs) treated with bleomycin foam. Materials and Methods Twenty patients (age, 2–68 y) presented with symptoms of swelling (n = 19; 95%), pain (n = 14; 70%), and bleeding (n = 4; 20%). Lesions were located in the head and neck in 17 patients (85%), extremities in two (10%), and mediastinum in one (5%). Twenty-seven embolizations were performed, with a mean of 1.7 ± 1.0 treatments per patient (range, 1–4). An average of 0.45 ± 0.4 U/kg of bleomycin foam was used per procedure, with a range of 0.1–2.3 U/kg. Results All procedures were technically successful with no intraprocedural complications. Mean follow-up was 66 days ± 80, with a range of 4–403 days. Postprocedure complications were minor in 6 of 27 procedures (22%) and major in 2 of 27 procedures (7%). All 20 patients (100%) reported improvement in their symptoms after a single treatment session. Postprocedural magnetic resonance (MR) imaging demonstrated volume reduction of treated lesions in 13 of 14 patients (93%), with a mean lesion volume reduction of 66% ± 21. Enhancement on MR imaging after treatment was decreased in 11 of 14 patients (79%), increased in two (14%), and stable in one (7%). T2 signal intensity on MR imaging after treatment was decreased in 12 of 14 patients (86%) and stable in two (14%). Conclusions The use of bleomycin foam for the percutaneous treatment of VMs is safe and effective. Foaming bleomycin may be used to address the dose limitations of the liquid.

Spondylodiscitis is a rare complication of unwitnessed button battery ingestion in children. We report a case of a 20-month-old girl who presented to the emergency room 2 weeks after endoscopic removal of unwitnessed, impacted esophageal battery. Delayed presentation of spondylodiscitis after foreign body removal is related to local injury, pressure necrosis, and perforation. The bilaminar shape of an unknown ingested foreign body should alert the treating physician that it might be a battery rather than a coin. Prompt evaluation with magnetic resonance imaging is essential to prevent neurological deficit and/or spinal deformities.

Spinal nerve root enhancement in pediatric patients is generally nonspecific, and clinical and laboratory correlation is essential. Nerve root enhancement indicates lack of integrity of the blood-nerve barrier. In this review, we will present a range of pediatric conditions that can present with spinal nerve root enhancement including inflammatory, infectious, hereditary, and neoplastic causes. Familiarity with the various pathologic entities associated with spinal nerve root enhancement is important for a concise differential diagnosis in the appropriate clinical setting. This will avoid unnecessary additional investigations.

Moyamoya disease and syndrome represent an important cause of acute and chronic stroke in children. Neuroimaging plays a critical role in the early recognition, differential diagnosis, treatment and follow-up. This review will discuss the imaging findings and techniques as well as an ideal imaging strategy in the management of children with various etiologies of moyamoya. In addition, the postoperative imaging findings after revascularization will be presented.

Fetal magnetic resonance imaging is well accepted as secondary image tool for the evaluation of pathologies affecting the fetal brain as detected on prenatal ultrasonography. Significantly, fewer articles have focused on the fetal spinal canal and its contents. Many malformations and pathologies involving the spinal canal and cord may however have a significant impact on the quality of life. In addition, anomalies of the spinal cord may affect the development of the fetal brain or may be part of a more extensive malformation that may also affect the major thoracic and abdominal organs. A thorough knowledge of the nor- mal and abnormal development of the spinal column and its contents is necessary to diagnose and understand the encountered findings. In the current review the value of fetal magnetic resonance imaging of the spinal column and cord is discussed. The most frequently encountered malformations will be presented and discussed in the context of the most relevant embryological processes.

Early, sensitive and specific prenatal diagnosis of malformations of the fetal brain and correct identification of the various etiologies of ventriculomegaly are essential for the pre-, peri-, and postnatal management. Prenatal ultrasonography (US) is the primary imaging modality for identification of fetal central nervous system (CNS) pathology. However, prenatal US may not always identify the full spectrum of pathology. Consequently, the final diagnosis may be incorrect or underestimate the CNS anomaly. Fetal magnetic resonance imaging has emerged as a valuable, safe and easy to perform secondary imaging tool for the evaluation of the fetal CNS. The high spatial resolution, good signal to noise ratio, and high contrast to noise ratio allow the study of various developmental processes of the fetal CNS in detail. Consequently, fetal magnetic resonance imaging may show pathology that remained undetected on prenatal US. The extra information has proven invaluable for managing these high-risk pregnancies and is also important for the counseling of the parents. In the current review we discuss various frequently encountered brain malformations as well as the various etiologies of "ventriculomegaly".

Pediatric patients undergoing MRI often require general anesthesia, which may improve image quality but is associated with significant medical risk and economic cost. It has previously been shown that certified child life specialists using high-tech interventions (eg, MRI-compatible video goggles) significantly reduce the number of pediatric MRI patients who require sedation. Most imaging centers lack such technology, however, and it remains unclear whether simpler and less costly child life interventions may be equally effective in avoiding general anesthesia. The aim of this study was to assess the impact of requiring mandatory child life evaluation for all patients aged 5 to 18 years undergoing MRI before referral for general anesthesia. Inserting this simple step into the scheduling workflow significantly reduced the use of general anesthesia in this population: general anesthesia was required in 564 of 2,433 MRI cases during the 1-year baseline period compared with 484 of 2,526 cases during the 1-year intervention period (P < .01 by z test for proportions; absolute reduction, 4.0%; relative reduction, 14.8%). The authors estimate that instituting mandatory child life evaluation avoided the use of general anesthesia in approximately 102 patients during the intervention period. Further subgroup analysis revealed that avoidance of general anesthesia was highly significant in the 5- to 10-year-old age group, whereas those aged 11 to 18 years experienced only a trend toward modestly decreased use of general anesthesia. These results suggest that mandatory evaluation for standard child life interventions is a worthwhile step that can save many children from unnecessary exposure to the risks, cost, and inconvenience of general anesthesia.

The frequency and importance of the evaluation of the posterior fossa have increased significantly over the past 20 years owing to advances in neuroimaging. Nowadays, conventional and advanced neuroimaging techniques allow detailed evaluation of the complex anatomic structures within the posterior fossa. A wide spectrum of congenital abnormalities has been demonstrated, including malformations (anomalies due to an alteration of the primary developmental program caused by a genetic defect) and disruptions (anomalies due to the breakdown of a structure that had a normal developmental potential). Familiarity with the spectrum of congenital posterior fossa anomalies and their well-defined diagnostic criteria is crucial for optimal therapy, an accurate prognosis, and correct genetic counseling. The authors discuss the spectrum of posterior fossa malformations and disruptions, with emphasis on neuroimaging findings (including diagnostic criteria), neurologic presentation, systemic involvement, prognosis, and risk of recurrence.

BACKGROUND AND PURPOSE: Head CT is the current neuroimaging tool of choice in acute evaluation of pediatric head trauma. The potential cancer risks of CT-related ionizing radiation should limit its use in children. We evaluated the role of MR imaging, including a “black bone” sequence, compared with CT in detecting skull fractures and intracranial hemorrhages in children with acute head trauma. MATERIALS AND METHODS: We performed a retrospective evaluation of 2D head CT and brain MR imaging studies including the black bone sequence of children with head trauma. Two experienced pediatric neuroradiologists in consensus created the standard of reference. Another pediatric neuroradiologist blinded to the diagnosis evaluated brain MR images and head CT images in 2 separate sessions. The presence of skull fractures and intracranial posttraumatic hemorrhages was evaluated. We calculated the sensitivity and specificity of CT and MR imaging with the black bone sequence in the diagnosis of skull fractures and intracranial hemorrhages. RESULTS: Twenty-eight children (24 boys; mean age, 4.89 years; range, 0–15.5 years) with head trauma were included. MR imaging with the black bone sequence revealed lower sensitivity (66.7% versus 100%) and specificity (87.5% versus 100%) in identifying skull fractures. Four of 6 incorrectly interpreted black bone MR imaging studies showed cranial sutures being misinterpreted as skull fractures and vice versa. CONCLUSIONS: Our preliminary results show that brain MR imaging complemented by a black bone sequence is a promising nonionizing alternative to head CT for the assessment of skull fractures in children. However, accuracy in the detection of linear fractures in young children and fractures of aerated bone remains limited.

Pediatric spinal trauma is unique. The developing pediatric spinal column and spinal cord deal with direct impact and indirect acceleration/deceleration or shear forces very different compared to adult patients. In addition children are exposed to different kind of traumas. Moreover, each age group has its unique patterns of injury. Familiarity with the normal developing spinal anatomy and kind of traumas is essential to correctly diagnose injury. Various imaging modalities can be used. Ultrasound is limited to the neonatal time period; plain radiography and computer tomography are typically used in the acute work-up and give highly detailed information about the osseous lesions. Magnetic resonance imaging is more sensitive for disco-ligamentous and spinal cord injuries. Depending on the clinical presentation and timing of trauma the various imaging modalities will be employed. In the current review article, a summary of the epidemiology and distribution of posttraumatic lesions is discussed in the context of the normal anatomical variations due to progressing development of the child.

Neurofibromatosis bright objects (NBOs) are poorly understood. This article aimed to investigate: 1) differences in fractional anisotropy (FA) between NBOs based in gray matter (GM) and white matter (WM), and 2) the relationship between NBOs and the affected white matter tracts. Fourteen NF1 patients were included in this study. Apparent diffusion coefficient (ADC), FA, radial diffusivity (RD) and eigenvalues were used to compare NBOs and matching contralateral normal-appearing sites (NAS). Diffusion tensor imaging scalars were also compared with age-matched healthy controls. Fiber tractography was performed to assess NBO-induced changes in WM trajectories. ADC values were higher for GM and WM NBOs than for NAS and controls. FA values were lower in GM and WM NBOs compared with controls. In all regions, eigenvalues were higher in NBOs than in NAS and controls. Only three out of 18 NOBs appeared to disrupt WM tracts. ADC, Λ2 and RD values of WM NBOs were higher in symptomatic compared to asymptomatic patients. Increased ADC, RD and eigenvalues and decreased FA values in NBOs can be explained by myelin and axonal damage. Increased ADC values and RD in WM NBOs correlated with the presence of symptoms. Tract integrity predominated in our study.

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.

Hypoxic-ischemic injury (HII) continues to be an important cause of neonatal mortality and morbidity. In recent years, the role of magnetic resonance (MR) imaging has increased by providing early detection to initiate preventive measures and assess the severity of tissue injury, and it often serves as a prognostic indicator. However, because of the subtle findings and temporal variability of signal abnormalities, the imaging diagnosis often remains troublesome, particularly for trainees and general radiologists who do not often encounter these findings. The imaging manifestations between term and preterm infants differ significantly; the imaging findings in term neonates are discussed. Two main patterns of HII have been described in term neonates: peripheral and basal ganglia-thalamus, with the predominant pattern in an affected infant dependent on the duration and severity of the insult. The peripheral pattern occurs in the setting of mild hypoxia or ischemia of prolonged duration, with predominant findings in the cerebral cortex and subcortical white matter along the intervascular boundary zones. The basal ganglia-thalamus pattern is most often secondary to a more severe hypoxic or ischemic event of short duration and manifests with abnormal hyperintensity on T1-weighted images and hypointensity on T2-weighted images in the posterolateral putamen and ventrolateral thalamus. Associated loss of normal hyperintensity on T1-weighted images and hypointensity on T2-weighted images in the posterior limb of the internal capsule may be present. Restricted diffusion and evolution of imaging findings may be seen in each of these regions, depending on when images are obtained. Advanced imaging techniques, including MR spectroscopy, may add valuable information and specificity, with an abnormal lactate peak often serving as an indicator of HII in term neonates.

Classification of vascular anomalies (VAs) is challenging due to overlapping clinical symptoms, confusing terminology in the literature and unfamiliarity with this complex entity. It is important to recognize that VAs include two distinct entities, vascular tumours (VTs) and vascular malformations (VaMs). In this article, we describe SE Mitchell Vascular Anomalies Flow Chart (SEMVAFC), which arises from a multidisciplinary approach that incorporates clinical symptoms, physical examination and magnetic resonance imaging (MRI) findings to establish International Society for the Study of Vascular Anomalies (ISSVA)-based classification of the VAs. SEMVAFC provides a clear visual pathway for physicians to accurately diagnose Vas, which is important as treatment, management, and prognosis differ between VTs and VaMs.

Summary Background and purpose Susceptibility weighted imaging (SWI) allows the study of the intracranial venous vasculature based on the paramagnetic susceptibility effects of deoxygenated blood. Prominent hypointense draining veins have been revealed in ischemic brain tissue by SWI. The goal of our study was to evaluate whether a match or mismatch between territorial changes in the venous drainage of ischemic brain tissue, as identified by SWI and diffusion restriction, can show a ‘venous ischemic penumbra’. Materials and methods Eight children with a confirmed diagnosis of acute pediatric arterial ischemic stroke (PAIS) were included in this preliminary study. All had undergone an acute standard magnetic resonance imaging (MRI) study with diffusion-weighted imaging (DWI) and SWI sequences. SWI scans were semi-quantitatively evaluated for signal intensity and caliber of both the intramedullary and sulcal veins. In addition, SWI abnormalities were compared with DWI images for match/mismatch of signal alterations, and the acute MRI data were compared with follow-up scans. Results A total of 17 vascular territories showed infarction. SWI hypointensity in sulcal and intramedullary veins was found in 77% and 94% of the infarcted territories, respectively, while the caliber of the sulcal and intramedullary veins was increased in 64% and 88% of the infarcted areas, respectively. SWI/DWI match was observed in 88% of the vascular territories, whereas mismatch was noted in two; follow-up neuroimaging showed infarct progression into the mismatch areas. Conclusion Our study showed that, in children, high-quality SWI studies focused on venous drainage can provide important non-invasive data on critically perfused brain tissue at risk of infarct progression. SWI is therefore a valuable MR tool that can be added to the battery of neuroimaging techniques for acute PAIS.

Head ultrasonography (HUS) remains an important tool in the initial evaluation of intracranial abnormalities in infants. In experienced hands, HUS is an outstanding tool to detect brain abnormalities in preterm and full-term infants, to follow the progression of these lesions, and to describe the maturation of the infant brain. We believe it is a safe and cost-efficient alternative to magnetic resonance imaging and computerized tomography in many cases. In this article we discuss the HUS techniques that are currently available and are now the standard of care, how to perform them, and what to look for. We describe a variety of findings that may be encountered including hemorrhagic complications of prematurity, hypoxic ischemic brain injury, neonatal stroke, infections, malformations, neoplasms, and a few more rare neonatal pathologies.

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 T2 -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.

BACKGROUND Post-traumatic carotid artery dissection (PTCAD) may result in acute arterial ischemic stroke (AIS). Pediatric PTCAD is rarely diagnosed prior to onset of neurological symptoms. We report on neuroimaging findings in a series of children with PTCAD. METHODS Five children with head or neck trauma were included in this study. Clinical histories were reviewed for mechanism of trauma, symptoms, complications, therapy, and outcome. Computed tomography (CT), magnetic resonance imaging (MRI), and CT/MR angiography (CTA, MRA) studies were retrospectively evaluated for signs and complications of PTCAD and presence and extent of skull base fractures. RESULTS PTCAD was located at the level of the skull base in all children and was associated with a skull base fracture in two. The diagnosis was made in five children by combined MRI/MRA and in two by CTA. Air in the carotid canal suggested skull base injury with PTCAD in two children. PTCAD was complicated by AIS in three children. CONCLUSION PTCAD may result from neck and head trauma. To avoid secondary AIS, radiologists should be familiar with neuroimaging findings in children, especially as acute PTCAD may initially be clinically silent. Consequently, pediatric neuroradiologists should actively exclude PTCAD in children with head and neck trauma.

Keutel syndrome is a rare autosomal-recessive condition characterized by abnormal cartilage calcification. Neuroimaging findings associated with this condition have been randomly described in the literature. To systematically evaluate the neuroimaging findings in a series of children with Keutel syndrome to broaden our base of knowledge. Four children with confirmed Keutel syndrome were reviewed for the brain, head and neck imaging findings. Three of the four children, all siblings, showed evidence of moyamoya syndrome. All four siblings had pinna cartilage calcification. We propose that Keutel syndrome be considered and included among the secondary causes of moyamoya syndrome. In children with petrified auricle and neurological symptoms, Keutel syndrome should be considered and brain MRI with MRA is required.

Summary Objectives To evaluate the sensitivity and specificity of head ultrasound (HUS) in the detection of intracranial hemorrhage in premature neonates compared with brain MRI using susceptibility-weighted imaging (SWI). Material and methods Ultrasound (US) and MRI scans of the brain using SWI in premature neonates were retrospectively evaluated for grade I–III germinal matrix hemorrhage (GMH), periventricular hemorrhagic infarction (PVHI), intra-axial hemorrhage other than PVHI, extra-axial hemorrhage in each cerebral hemisphere and cerebellar hemorrhage in each cerebellar hemisphere. The impact of these hemorrhagic findings on short-term clinical management was also reviewed. Results Twelve neonates (mean age: 9.8 days; range: 3–23 days) with a mean gestational age of 32.8 weeks (range: 29.6–35.4 weeks) were included in the study. HUS had high sensitivity (100%) and specificity (93.3%) in detecting grade III GMH using SWI as a reference, but poor sensitivity (0%) in the detection of intraventricular hemorrhage with normal-sized ventricles (grade II GMH). US was not sensitive in detecting either small cerebellar or extra-axial hemorrhage. Conclusion HUS was highly sensitive and specific in the evaluation of grade III GMH, whereas SWI was superior to HUS in detecting small intra-axial or extra-axial hemorrhage, and had no impact on short-term management. Given the low cost, lack of radiation and advantages of bedside evaluation, HUS should continue to be the first line of imaging for brain injury in the evaluation of premature neonates with suspected intracranial hemorrhage. However, the usefulness of SWI for predicting long-term neurological outcomes has yet to be determined.

Congenital extra-adrenal neuroblastoma is a rare condition, which typically has a favorable prognosis. We present a unique case of extra-adrenal retroperitoneal neuroblastoma diagnosed by fetal magnetic resonance imaging, which ultimately leads to fetal hydrops and neonatal death.

Summary Objective Normative apparent diffusion coefficient (ADC) and fractional anisotropy (FA) metrics of the brain have been published previously. However, no larger studies evaluated the normal evolution of ADC/FA metrics of the maturing paediatric spinal cord. Goal of this study is to evaluate the age-dependent evolution of the ADC/FA values of the developing/maturing normal cervical spinal cord (CSC). Patients and methods Forty-one subjects, aged less than 18 years with a negative spinal MRI study and no systemic central nervous disease, underwent diffusion tensor imaging (DTI) of the CSC. DTI metrics were measured in the centre of the CSC. Regression and ANCOVA analyses were performed to evaluate the association between ADC/FA values and age and its potential modification by sex. Results A linear model emerged as the best fit for our data. ADC showed a continuous decrease with age; FA showed a continuous increase with age. Conclusion The simultaneous age-related ADC decrease and FA increase likely reflect progressive maturation, myelination and fibre packing within the CSC similar to that observed in the brain. Collection of age-dependent normative DTI metrics may be helpful in the early identification and quantification of altered water diffusion in a variety of pathologies affecting the developing paediatric spinal cord.

Traumatic brain injury (TBI) is a major cause of morbidity and mortality in children. The unique biomechanical, hemodynamical, and functional characteristics of the developing brain and the age-dependent variance in trauma mechanisms result in a wide range of age specific traumas and patterns of brain injuries. Detailed knowledge of the main primary and secondary pediatric injuries, which enhance sensitivity and specificity of diagnosis, will guide therapy and may give important information about the prognosis. In recent years, anatomical but also functional imaging methods have revolutionized neuroimaging of pediatric TBI. The purpose of this article is (1) to comprehensively review frequent primary and secondary brain injuries and (2) to give a short overview of two special types of pediatric TBI: birth related and nonaccidental injuries.

Birth-related injury is defined as any traumatic or ischemic event sustained during the process of delivery. Perinatally acquired disease processes secondary to birth-related injury can be traumatic or ischemic in nature. In this article, the authors focus on traumatic/mechanical injuries. Other diseases of the perinatal time period, including germinal matrix hemorrhages and hypoxic-ischemic encephalopathy, are beyond the objective of this review.

Susceptibility-weighted imaging (SWI) is a new high-resolution magnetic resonance imaging (MRI) tool that uses the paramagnetic susceptibility effects of deoxygenated blood to study the intracranial venous vasculature. We present SWI imaging findings in two children who suffered from acute arterial ischemia. Various patterns of normal/altered venous drainage could be identified. Our case study suggests that SWI assisted mapping of the regional changes of the cerebral venous drainage and correlation with diffusion weighted MRI may identify critically perfused brain at risk for infarct progression. Prospective studies are mandatory to further validate the value of SWI.

Summary Objectives The goal of our study was to: determine the incidence of cerebellar lesions in a cohort of children and young adults with TSC, and analyze the magnetic resonance imaging (MRI) findings of cerebellar TSC lesions including their contrast behavior and diffusion characteristics. Material and Methods MRI studies of 27 TSC patients (mean age, 10.6 years) were evaluated for: cortical/subcortical tubers, white matter lesions, subependymal nodules, and giant cell astrocytomas. Patients with cerebellar involvement were further analyzed for the imaging and diffusion characteristics. ADC measurements of the cerebellar tubers were performed and compared with the contralateral normal appearing cerebellum. The clinical charts were revisited for symptoms suggesting cerebellar involvement. Results Cerebellar tubers were seen in 8/27 patients, cerebellar atrophy in 1/27 patients. Cerebellar tubers showed a pyramidal/wedge appearance with a broad base reaching the cortex. The majority of the cerebellar tubers (11/12, 92%) showed a “zebra-like” contrast enhancement. All cerebellar tubers had increased ADC values (mean ADC 1472 × 10 −6 mm 2 /s). None of the patients had “typical” cerebellar symptoms. Conclusion Thirty-three percent of TSC patients had cerebellar lesions, most of them being cerebellar tubers. Cerebellar tubers differ from supratentorial tubers both concerning shape and contrast behavior. The exact etiology of contrast enhancement remains unclear. Future studies have to determine the impact of cerebellar lesions on neurocognitive development.

Summary Background and purpose Patients with Sturge-Weber syndrome (SWS) may present with neurological symptoms or neurocognitive deficits that cannot always be explained by the supratentorial findings seen on conventional MRI. Purpose of our study was to determine (a) what percentage of children with SWS have simultaneous supra- and infratentorial involvement and (b) what kind of infratentorial lesions are seen. In addition, we used DWI data to measure the ADC-values of normal appearing white matter (NAWM) to rule out impaired or delayed white matter maturation. Material and methods Fifteen SWS patients who underwent MRI/DWI between January 2000 and August 2008 were studied. Images were retrospectively reviewed by two experienced pediatric neuroradiologists. ADC measurements of the NAWM were performed at multiple locations within the brain. ADC-values were compared with normative data and with 18 matched normal controls from our hospital. Results Infratentorial involvement was seen in six out of 15 patients (40%). Cerebellar lesions included leptomeningeal enhancement, atrophy and developmental venous anomaly. ADC-values were increased in the NAWM of the frontal, parietal and occipital lobes of both hemispheres and in the pons. The ADC-values of the cerebellar white matter were increased in six out of eight affected cerebellar lobes. Conclusion Infratentorial involvement of SWS is more frequently than previously thought. ADC analysis of the NAWM reveals impaired/altered white matter maturation distant from the area of leptomeningeal angiomatosis. This may explain neurocognitive deficits. ADC analysis of the NAWM may serve as biomarker of tissue injury and therefore guide treatment options.

Introduction Patients with tuberous sclerosis complex (TSC) frequently present with neurocognitive deficits which may be related to impaired white matter maturation. The purposes of our study were (a) to evaluate the white matter maturation in children and young adults with TSC by comparing the apparent diffusion coefficient (ADC) values of normal-appearing white matter (NAWM) with age-matched healthy controls and (b) to determine the association of NAWM-ADC values with the severity of neurological symptoms in TSC patients. Methods Twenty-three TSC patients who underwent magnetic resonance imaging/diffusion-weighted imaging between January 2000 and January 2009 were studied. ADC values of NAWM were measured in the frontal, parietal, occipital lobes, and in the pons. ADC data were compared with age-matched normative data derived from healthy controls. Patients were neurologically scored by a pediatric neurologist. Two-sample t tests and linear regression were conducted using STATA software. Results ADC values of NAWM were higher in TSC patients compared with healthy controls; the increase, however, only reached statistical significance in the frontal white matter and pons in the age group between 96 and 144 months and in the right parietal and occipital white matter in the age group above 144 months. There was no significant change in neurological severity score per unit increase in ADC measurement. Conclusion ADC values of NAWM appear increased in TSC patients. The abnormal ADC values suggest that myelination may be delayed/impaired in TSC patients, which could explain global neurocognitive deficits. Larger prospective studies, including diffusion tensor imaging, are necessary to validate our results.

Littoral cell angioma (LCA) is a rare primary splenic vascular tumor originating from littoral cells lining the splenic red pulp sinuses. LCAs are rarely seen in children. We present the US, CT, and MRI findings including diffusion-weighted imaging (DWI) in a 2-year-old boy with histologically proven LCA. Previous studies on liver lesions have shown that DWI allows differentiation of vascular tumors from primary neoplasms and metastatic disease. The current case indicates that increased ADC values within the splenic lesions suggest a vascular etiology, which might help narrow the differential diagnosis.

OBJECTIVES The purpose of this study was to determine the value of resistive index (RI) variability in predicting cerebrovascular complications during extracorporeal membrane oxygenation (ECMO). METHODS This retrospective study included 36 infants treated by ECMO. The RI was measured on daily transfontanellar duplex sonography, obtained first without fontanel compression and then after gentle compression with the transducer. The age at ECMO cannulation, sex, gestational age at birth, method of delivery, indication, and type and duration of ECMO were recorded. RESULTS There was a statistically significant difference in RI variability in infants who developed cerebrovascular complications as opposed to those who did not (P = .002). Resistive index variability of 10% or greater on any day was associated with an increased risk for cerebrovascular complications (P = .0482; χ2 = 3.9). Variability in the first 5 days was significantly higher than on following days (P < .0001). The age at ECMO cannulation showed a significant difference, with mean ± SD values of 1.1 ± 0.9 days in the complications group and 2.7 ± 2.2 days in the no-complications group (P = .043). CONCLUSIONS Resistive index variability of 10% or greater on any day had a statistically significant risk of cerebrovascular complication development. Extracorporeal membrane oxygenation cannulation at younger than 3 days conferred an increased risk of cerebrovascular complications.

Radiologic diagnosis of skull fractures in young children is difficult due to numerous accessory sutures. This is especially true around the occipital bone because it has more than one ossification center. Normal anatomic variants, such as the mendosal suture, may be misinterpreted as a skull fracture. We investigated the anatomic traits of the mendosal suture in young children. We retrospectively evaluated 52 children, aged between 1 month and 4 years, who had undergone head computed tomography with three-dimensional reconstructions. We evaluated the presence or absence of the mendosal suture. If present, then we measured the length of the suture and the angle between the lambdoidal and mendosal suture lines. The presence of the mendosal suture was bilateral in 12 children and unilateral in 5 children. The mendosal suture had a mean length of 13.9 ± 3.4 mm on the right side and 11.2 ± 4 mm on the left side. The angle between the mendosal and lambdoidal sutures had a mean value of 54.2° ± 11° for the right side and 53.6° ± 13.9° for the left side. The 95 % confidence interval for the mean value of the angle had a lower and upper bounds of 48° and 60° on the right side and 46° and 61° on the left side, respectively. The angle between mendosal and lambdoidal suture lines may help radiologists to identify the mendosal suture.