Advances in Imaging Modalities for Pediatric Brain and Spinal Cord Tumors

BACKGROUND

Neuroimaging has evolved from anatomical imaging toward a multi-modality comprehensive anatomical and functional imaging in the past decades, important functional data like perfusion-weighted imaging, permeability imaging, diffusion-weighted imaging (DWI), and diffusion tensor imaging (DTI), tractography, metabolic imaging, connectomics, event-related functional imaging, resting state functional imaging, and much more is now being offered.

SUMMARY

Precision diagnostics has proven to be essential for precision treatment. Many minimal invasive techniques have been developed, taking advantage of digital subtraction angiography and interventional neuroradiology. Furthermore, intraoperative CT and/or MRI and more recently MR-guided focused ultrasound have complemented the diagnostic and therapeutic armamentarium.

KEY MESSAGES

In the current manuscript, we discuss standard imaging sequences including advanced techniques like DWI, DTI, susceptibility-weighted imaging, and 1H magnetic resonance spectroscopy, various perfusion weighted imaging approaches including arterial spin labeling, dynamic contrast enhanced imaging, and dynamic susceptibility contrast imaging. Pre-, intra, and postoperative surgical imaging including visualize imaging will be discussed. The value of connectomics will be presented for its value in neuro-oncology. Minimal invasive therapeutic possibilities of interventional neuroradiology and image-guided laser ablation and MR-guided high-intensity-focused ultrasound will be presented for treatment of pediatric brain and spinal cord tumors. Finally, a comprehensive review of spinal cord tumors and matching neuropathology has been included.

Association between ambulatory skills and diffusion tensor imaging of corpus callosal white matter in infants with spina bifida

OBJECTIVES

To assess brain white matter using diffusion tensor imaging (DTI) at 1 year of age in infants diagnosed with open neural tube defect (ONTD) and explore the association of DTI parameters with ambulatory skills at 30 months of age.

METHODS

Magnetic resonance imaging (MRI) was performed at an average of 12 months of age and included an echo planar axial DTI sequence with diffusion gradients along 20 non-collinear directions. TORTOISE software was used to correct DTI raw data for motion artifacts, and DtiStudio, DiffeoMap and RoiEditor were used for further postprocessing. DTI data were analyzed in terms of fractional anisotropy (FA), trace, radial diffusivity and axial diffusivity. These parameters reflect the integrity and maturation of white-matter motor pathways. At 30 months of age, ambulation status was evaluated by a developmental pediatrician, and infants were classified as ambulatory if they were able to walk independently with or without orthoses or as non-ambulatory if they could not. Linear mixed-effects method was used to examine the association between study outcomes and study group. Possible confounders were sought, and analyses were adjusted for age at MRI scan and ventricular size by including them in the regression model as covariates.

RESULTS

Twenty patients with ONTD were included in this study, including three cases that underwent postnatal repair and 17 cases that underwent prenatal repair. There were five ambulatory and 15 non-ambulatory infants evaluated at a mean age of 31.5 ± 5.7 months. MRI was performed at 50.3 (2-132.4) weeks postpartum. When DTI analysis results were compared between ambulatory and non-ambulatory infants, significant differences were observed in the corpus callosum (CC). Compared with non-ambulatory infants, ambulatory infants had increased FA in the splenium (0.62 (0.48-0.75) vs 0.41 (0.34-0.49); P = 0.01, adjusted P = 0.02), genu (0.64 (0.47-0.80) vs 0.47 (0.35-0.61); P = 0.03, adjusted P = 0.004) and body (0.55 (0.45-0.65) vs 0.40 (0.35-0.46), P = 0.01, adjusted P = 0.01). Reduced trace was observed in the CC of ambulatory children at the level of the splenium (0.0027 (0.0018-0.0037) vs 0.0039 (0.0034-0.0044) mm² /s; P = 0.04, adjusted P = 0.03) and genu (0.0029 (0.0020-0.0038) vs 0.0039 (0.0033-0.0045) mm² /s; P = 0.04, adjusted P = 0.01). In addition, radial diffusivity was reduced in the CC of the ambulatory children at the level of the splenium (0.00057 (0.00025-0.00089) vs 0.0010 (0.00084-0.00120) mm² /s; P = 0.02, adjusted P = 0.02) and the genu (0.00058 (0.00028-0.00088) vs 0.0010 (0.00085-0.00118) mm² /s; P = 0.02, adjusted P = 0.02). There were no differences in axial diffusivity between ambulatory and non-ambulatory children.

CONCLUSION

This study demonstrates a significant association between white matter integrity of connecting fibers of the corpus callosum, as assessed by DTI, and ambulatory skills at 30 months of age in infants with ONTD. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Diagnostic Accuracy of MRI for Detection of Meningitis in Infants

PURPOSE

To determine the accuracy of MR imaging for diagnosis of meningitis in infants.

MATERIALS AND METHODS

Retrospective review of infants less than 1 year of age who underwent a brain MR imaging for meningitis from 2010-2018. Gold standard for diagnosis of bacterial meningitis was a positive bacterial CSF culture or a positive blood culture with an elevated CSF WBC count, and diagnosis of viral meningitis was a positive CSF PCR result and elevated CSF WBC count. Sensitivity, specificity, PPV, NPV, and accuracy for MR imaging diagnosis of meningitis were calculated.

RESULTS

Two hundred nine infants with mean age 80 days (range 0-347 days) were included. There were 178 true positives with the most common pathogens being: Group B Streptococcus (58), E. coli (50), Streptococcus pneumoniae (21), H. influenzae (4); Herpes simplex virus 1 or 2 (18); Enterovirus (4); and other (23). There were 31 true negatives. Range of sensitivity, specificity, PPV, NPV, and accuracy of MR imaging for detection of meningitis was 67.4-83.5%, 92.3-95.7%, 95.0-98.6%, 33.3-76.5%, and 71.3-86.5% respectively. MR imaging sensitivity decreased after 10 days from time of presentation while specificity remained stable. Among individual MR imaging findings, leptomeningeal enhancement was the most sensitive finding, while cerebritis, infarction, ventriculitis, abscess, and intraventricular purulent material were the most specific findings.

CONCLUSIONS

MR imaging of the brain demonstrates high specificity and moderate sensitivity for diagnosis among infants presenting with signs and symptoms of meningitis. The results reflect current standard of care for imaging of infants with meningitis however a selection bias for imaging of more severe meningitis may affect these results.

COVID-19 Vaccination May Provoke Intracranial Hypertension

In parallel to the spread of the novel severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), there has been the growing recognition that active SARS-CoV-2 infection has the potential to effect both the peripheral and central nervous systems. When it comes to the SARS-CoV-2 vaccine, however, reporting has been more uncertain. As the vaccination rate has risen, we have seen a rise in rare neurological complications thought to be associated with the vaccination including acute transverse myelitis, Guillain–Barre syndrome, optic neuritis, and Tolosa–Hunt syndrome. The Centers for Disease Control and Prevention (CDC) estimates 98 confirmed cases of Guillain–Barre syndrome out of 12.6 million doses. Given the initial age limits of vaccination eligibility, most reports have been limited to the adult population. Here, we report a case of intracranial hypertension (IH), evolving to fulminant IH in a healthy female after receiving the SARS-CoV-2 vaccine. While elevated intracranial pressure has been reported in the context of active SARS-CoV-2 infections and postinfection multisystem inflammatory syndrome (MIS-C), this is the first reported case of pediatric IH after vaccination alone.

Neuroimaging in cerebellar ataxia in childhood: A review

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.

Another Piece of the Puzzle of Anomalous Connectivity in Joubert's Syndrome

We report on the conventional and diffusion tensor imaging (DTI) findings of a 2-year-old child with clinical presentation of Joubert's Syndrome (JS) and brainstem structural abnormalities as depicted by neuroimaging.Conventional magnetic resonance imaging (MRI) showed a "molar tooth" configuration of the brainstem. A band-like formation coursing in an apparent axial plane anterior to the interpeduncular fossa was noted and appeared to partially cover the interpeduncular fossa.DTI maps and three-dimensional (3D) tractography demonstrated a prominent red-encoded white matter bundle anterior to the midbrain. Probable aberrant course of the bilateral corticospinal tracts (CST) was also depicted. Absence of the decussation of the superior cerebellar peduncles and elongated thickened, horizontal superior cerebellar peduncle (SCP) reflecting the molar tooth sign were also shown.Our report and the review of the published cases suggest that DTI and tractography may be very helpful to differentiate between interpeduncular heterotopias and similarly located white matter bundles corroborating the underlying etiology of axonal guidance disorders in the complex group of ciliopathies including JS. Our case represents an important additional puzzle piece to explore the variability of these ciliopathies.

An In-Depth Analysis of Brain and Spine Neuroimaging in Children with Abusive Head Trauma: Beyond the Classic Imaging Findings

BACKGROUND AND PURPOSE

Abusive head trauma is the leading cause of morbidity and mortality in young children. Radiology provides valuable information for this challenging diagnosis, but no single neuroimaging finding is independently diagnostic of abusive head trauma. Our purposes were to describe the prevalence of brain and spine neuroimaging findings and to analyze the association of neuroimaging findings with clinical factors to determine which neuroimaging findings may be used as prognostic indicators.

MATERIALS AND METHODS

Children with a confirmed abusive head trauma diagnosis between January 2018 to February 2021 were included in this single-center retrospective study. Patient demographics, survival, Glasgow Coma Scale score on admission, length of hospital stay, and intensive care unit stay were examined. Brain neuroimaging findings were categorized as classic and nonclassic findings. Spine MRIs were also assessed for spinal ligamentous injury, compression fracture, and hemorrhage. The χ² test or the Wilcoxon rank-sum test was used for the analysis.

RESULTS

One hundred two children (male/female ratio: 75:27; average age, 9.49; range, 0.27-53.8 months) were included. Subdural hematoma was the most common (83.3%) classic neuroimaging finding. Bridging vein thrombosis was the most common (30.4%) nonclassic neuroimaging finding. Spinal ligamentous injury was seen in 23/49 patients. Hypoxic-ischemic injury was significantly higher in deceased children (P = .0001). The Glasgow Coma Scale score was lower if hypoxic-ischemic injury (P < .0001) or spinal ligamentous injury were present (P = .017). The length of hospital stay was longer if intraventricular hemorrhage (P = .04), diffuse axonal injury (P = .017), hypoxic-ischemic injury (P = .001), or arterial stroke (P = .0003) was present. The intensive care unit stay was longer if intraventricular hemorrhage (P = .02), diffuse axonal injury (P = .01), hypoxic-ischemic injury (P < .0001), or spinal ligamentous injury (P = .03) was present.

CONCLUSIONS

Our results may suggest that a combination of intraventricular hemorrhage, diffuse axonal injury, hypoxic-ischemic injury, arterial stroke, and/or spinal ligamentous injury on neuroimaging at presentation may be used as potential poor prognostic indicators in children with abusive head trauma.

Characterization of Restenosis following Carotid Endarterectomy Using Contrast-Enhanced Vessel Wall MR Imaging

BACKGROUND AND PURPOSE

Restenosis is an important determinant of the long-term efficacy of carotid endarterectomy. Our aim was to assess the role of high-resolution vessel wall MR imaging for characterizing restenosis after carotid endarterectomy.

MATERIALS AND METHODS

Patients who underwent vessel wall MR imaging after carotid endarterectomy were included in this study. Restenotic lesions were classified as myointimal hyperplasia or recurrent atherosclerotic plaques based on MR imaging features of lesion compositions. Imaging characteristics of myointimal hyperplasia were compared with those of normal post-carotid endarterectomy and recurrent plaque groups. Recurrent plaques were matched with primary plaques by categories of stenosis, and differences in plaque features were compared between the 2 groups.

RESULTS

Twenty-two recurrent lesions from 18 patients (14 unilateral and 4 bilateral) were classified as myointimal hyperplasia or recurrent plaque. Myointimal hyperplasia showed no difference in enhancement compared with normal post-carotid endarterectomy vessels (5 unilateral) but showed stronger enhancement than recurrent plaques (80.10% [SD, 42.42%] versus 56.74% [SD, 46.54%], P = .042). A multivariate logistic regression model of plaque-feature detection in recurrent plaques compared with primary plaques adjusted for maximum wall thickness revealed that recurrent plaques were longer (OR, 4.27; 95% CI, 1.32-13.85; P = .015) and more likely to involve a flow divider and side walls (OR, 6.96; 95% CI, 1.37-35.28; P = .019). Recurrent plaques had a higher prevalence of intraplaque hemorrhage (61.5% versus 30.8%, P = .048) by a χ² test, but compositional differences were not significant in the multivariate model.

CONCLUSIONS

Vessel wall MR imaging can distinguish recurrent plaques from myointimal hyperplasia and reveal features that may differ between primary and recurrent plaques, highlighting its value for evaluating patients with carotid restenosis.

Neuroimaging of primary mitochondrial disorders in children: A review

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.

Conventional and advanced MR imaging findings in a cohort of pathology-proven dermoid cysts of the pediatric scalp and skull

BACKGROUND

In the pediatric population, dermoid cysts are among the most frequent lesions of the scalp and skull. Imaging plays a key role in characterizing scalp and skull lesions in order to narrow the differential diagnoses. In general, dermoids are described as heterogeneous T1-/T2-hypo- to hyperintense lesions on magnetic resonance imaging.

METHODS

The goal of this retrospective study is to evaluate the diffusion weighted imaging findings while reviewing the conventional T1-/T2-/T1+C-weighted MR characteristics in a pathology-proven series of 14 dermoids of the pediatric scalp and skull.

RESULTS

In our pediatric cohort (eight boys, six girls, age range 3-95 months), half of the dermoids were homogeneous T1-hypointense and homogeneous T2-hyperintense. We found a mixture of restricted (45.5%) and increased diffusion (54.5%) in dermoids. The vast majority of dermoids (91.7%) showed rim enhancement. Most dermoids (57.1%) were located at the midline and adjacent to one of its sutures.

CONCLUSIONS

This study suggests that dermoids may have more variable imaging appearances than hitherto assumed and are frequently seen in close proximity or adjacent to the anterior fontanelle.

Can MRI Differentiate between Infectious and Immune-Related Acute Cerebellitis? A Retrospective Imaging Study

BACKGROUND AND PURPOSE

Acute cerebellitis is an acute neurologic condition attributable to a recent or concurrent infection or a recent vaccination or ingestion of medication, with MR imaging evidence of cerebellar edema. MR imaging can confirm an anatomic abnormality and may allow the radiologist to establish a differential diagnosis. The purpose of this research was to evaluate the MR imaging findings in children with acute cerebellitis due to infectious versus immune-related conditions, in particular whether MR imaging findings allow differentiation.

MATERIALS AND METHODS

Electronic medical records were reviewed between 2003 and 2020 in our quaternary children's hospital. Data included demographics and clinical records: presentation/symptoms, final diagnosis including acute cerebellitis and immune-related acute cerebellitis, length of stay, treatment, condition at discharge, and laboratory findings. Retrospective independent review of all brain MR imaging studies was performed.

RESULTS

Forty-three patients (male/female ratio, 28:15) were included in this study. Average age at presentation was 7.08 years (range, 0.05-17.52 years). Thirty-five children had infectious and 8 children had immune-related acute cerebellitis. Significant differences in neuroimaging were the following: 1) T2-FLAIR hyperintense signal in the brainstem (37.50% versus 2.85%, P = .016); 2) T2-FLAIR hyperintense signal in the supratentorial brain higher in the immune-related group (37.50% versus 0.00%, P = .004); and 3) downward herniation, higher in the infectious acute cerebellitis group (42.85% versus 0.00%, P = .03).

CONCLUSIONS

Acute cerebellitis is a rare condition, and MR imaging is helpful in the differential diagnosis. T2-FLAIR hyperintense signal in the brainstem and supratentorial brain may be indicative of immune-related acute cerebellitis, and downward herniation may be indicative of infectious acute cerebellitis.

Pulmonary manifestations and outcomes in paediatric ANCA-associated vasculitis: a single-centre experience

OBJECTIVES

ANCA-associated vasculitis (AAV) usually involves the renal and respiratory systems, but the paediatric literature on pulmonary manifestations and outcomes is limited. We aimed to describe pulmonary manifestations and outcomes after therapy in a cohort of paediatric AAV (pAAV) patients.

METHODS

A retrospective chart review of all patients <19 years presenting to our institution with AAV between 1/2008 and 2/2018 was conducted. Patient demographics, clinical presentation, diagnostic testing, therapy and pulmonary outcomes over the first 3 years after presentation were evaluated.

RESULTS

A total of 38 patients were included; all had ANCA positivity by immunofluorescence. A total of 23 had microscopic polyangiitis (MPA), 13 had granulomatosis with polyangiitis and 2 had eosinophilic granulomatosis with polyangiitis. A total of 30 (79%) had pulmonary manifestations, with cough (73%) and pulmonary haemorrhage (67%) being the most common. Abnormalities were noted in 82% of chest CT scans reviewed, with nodules and ground-glass opacities being the most common. At 6, 12 and 36 months follow-up, respectively, 61.8%, 39.4% and 29% of patients continued to show pulmonary manifestations. Five MPA patients with re-haemorrhage are described in detail.

CONCLUSION

MPA was more common than granulomatosis with polyangiitis, with pulmonary involvement being common in both. MPA patients had more severe pulmonary manifestations. Chest CT revealed abnormal findings in a majority of cases. A subgroup of young MPA patients experienced repeat pulmonary haemorrhage. Treatment modality and response were comparable in different subtypes of AAV, except for this young MPA group. Additional prospective studies are needed to better understand the different phenotypes of pAAV.

Neuroimaging Features of Ectopic Cerebellar Tissue: A Case Series Study of a Rare Entity

Ectopic cerebellar tissue is a rare entity likely secondary to multiple, interacting, developmental errors during embryogenesis. Multiple sites of ectopic cerebellar tissue have been reported, including extracranial locations; however, an intracranial location is most common. We report on the MR imaging findings of a multi-institutional series of 7 ectopic cerebellar tissue cases (2 males, 4 females, 1 fetal) ranging from 22 weeks 5 days' gestational age to 18 years of age. All cases of ectopic cerebellar tissue were diagnosed incidentally, while imaging was performed for other causes. Ectopic cerebellar tissue was infratentorial in 6/7 patients and supratentorial in 1/7 patients. All infratentorial ectopic cerebellar tissue was connected with the brain stem or cerebellum. MR imaging signal intensity was identical to the cerebellar gray and white matter signal intensity on all MR imaging sequences in all cases. Ectopic cerebellar tissue should be considered in the differential diagnoses of extra-axial masses with signal characteristics similar to those of the cerebellum. Surgical biopsy or resection is rarely necessary, and in most cases, MR imaging is diagnostic.

Possible additional MRI markers for critical brain swelling with increased intracranial pressure in children?

A retrospective study was performed evaluating the volume and T2/T1 signal intensity of orbital fat in five children diagnosed with severe global brain swelling and confirmed cessation of cerebral perfusion. Imaging showed a volume increase (five of five) and a heterogeneous T2-hypointensity of orbital fat (four of five). This preliminary study suggests that swelling and T2-hypointensity of orbital fat may be a marker of global brain swelling and/or increased intracranial pressure.

Presentation of External Ear Rosai-Dorfman Disease With Laryngeal Involvement

Rosai-Dorfman disease (RDD) is a rare benign systemic histiocytic proliferation characterized by massive lymph node enlargement and sometimes associated with extranodal involvement. Even though it is considered to be benign, death can occur depending on the extent and location. Our case highlights a primary extranodal site of the right pinna with extension through the Eustachian tube to the subglottis. A previously healthy 15-year-old female presented with 1-year right pinna swelling, slowly enlarging and becoming more bothersome. An incisional biopsy was performed on the ear along with S100 staining yielding a diagnosis. After multidisciplinary case discussion, clofarabine monotherapy and systemic therapy for Langerhans cell histiocytosis has started. Rosai-Dorfman disease can be a general disorder, often affecting the lymph nodes. Unlike a nodal disease, extranodal disease could involve any site on the patient's anatomy. Head and neck lesions are the most common extranodal lesions. Rosai-Dorfman disease is self-limited in more than 20% of the cases with spontaneous regression without intervention; 70% of the patients have noticeable symptoms and vital organ involvement requiring treatments such as surgery, steroids, radiation, and chemotherapy. In our case, the patient had wide involvement and presented without any serious breathing difficulties; we decided to start with monotherapy with chemotherapy and systematic glucocorticoid treatment.

Fetal MRI assessment of posterior fossa anomalies: A review

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.

Diagnostic sensitivity and specificity of CT angiography for renal artery stenosis in children

BACKGROUND

Children with suspected renal artery stenosis (RAS) are screened with renal Doppler ultrasonography or computed tomography (CT) angiography/magnetic resonance (MR) angiography depending on institutional preference. CT angiography produces images with superior resolution, allowing higher quality multiplanar two-dimensional reformats and three-dimensional reconstructions. However, there is a paucity of data in the literature regarding the utility and diagnostic performance of renal CT angiography in pediatric RAS.

OBJECTIVE

The objective of this study is to retrospectively review our experience with renal CT angiography in the diagnosis of pediatric RAS relative to digital subtraction angiography (DSA) as the reference standard.

MATERIALS AND METHODS

All patients 0-18 years of age who underwent CT angiography for evaluation of RAS as a cause of hypertension between January 2012 and May 2019 were identified for the study. A total of 131 patients were identified, 23 of whom had DSA correlation.

RESULTS

Twenty-three patients (17 boys, 6 girls) with a mean age of 6 years 3 months (range: 3 months to 14 years 7 months) were included in this study. Of the 59 renal arteries studied by DSA, 22 were abnormal on CT angiography and 20 were abnormal on DSA. Of the 59 renal arteries, CT angiography was true positive in 18 and true negative in 35. The sensitivity and specificity of CT angiography for RAS diagnosis were 90.0% and 89.7%, respectively. CT angiography identified all cases of main RAS.

CONCLUSION

Renal CT angiography has a high sensitivity and specificity for pediatric RAS diagnosis in patients referred for DSA.

Maternal serum alpha-fetoprotein level and the relationship to ventriculomegaly in fetal neural tube defect: A retrospective cohort study

OBJECTIVE

To estimate the significance of the association between mid-trimester maternal serum alpha-fetoprotein (MSAFP) level and fetal neuroanatomic findings in cases of open neural tube defect (ONTD).

METHODS

Retrospective study of patients referred for prenatal ONTD repair between 2012 and 2018. Cases were classified into three groups based on their MSAFP level: 1)High MSAFP (>3.8MoM - n = 22), 2)Moderately high MSAFP (≤3.8 and ≥2.5MoM - n = 28), 3)Normal MSAFP (<2.5MoM - n = 18). MRI scans at the time of referral were used to assess the relationship between MSAFP and: A)Type of ONTD; B) Ventriculomegaly; C) Size of the myeloschisis lesion; D) Volume of myelomeningocele; E) Anatomical level of the lesion (LL).

RESULTS

Having a high MSAFP level was more likely to be associated ventriculomegaly at mid-gestation than a moderately high or normal MSAFP level (OR = 8.4;CI95[0.9-73.4];p = 0.05 and OR = 2.8;CI95[0.9-8.8];p = 0.07). There were no differences between the three groups regarding type of lesion, size of the myeloschisis lesion, anatomic LL, or volume of the myelomeningocele sac. Myeloschisis cases with normal MSAFP had a larger surface area when compared to myeloschisis cases with moderately high MSAFP (219.8[104.4-551] vs 155.4[38.5-502.4] mm², p = 0.04).

CONCLUSION

A 2nd trimester MSAFP level >3.8MoM in a fetus with ONTD is associated with mid-gestation ventriculomegaly.

Neuroimaging Offers Low Yield in Children Positive for SARS-CoV-2

The coronavirus disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome coronavirus disease 2 (SARS CoV-2) most commonly presents with respiratory disease, but neurologic complications are being reported. We aimed to investigate the rate of positive neuroimaging findings in children positive for SARS-CoV-2 referred for neuroimaging between March 18 and September 30, 2020. We found that 10% (n = 2) had acute findings. Our results may suggest that in children, neurologic involvement in COVID-19 is rare, neuroimaging has a low yield in diagnosis, and acute neuroimaging should involve careful risk-benefit analysis.

Neuroimaging Characteristics of Nasopharyngeal Carcinoma in Children

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.

Neuroimaging Appearance of Cerebral Malignant Epithelioid Glioneuronal Tumors in Children

Malignant epithelioid glioneuronal tumor is a rare high-grade, aggressive brain tumor that shows both glial and neuronal differentiation on histopathology but is not included in the current World Health Organization classification. The neuroimaging appearance is variable but may be secondary to the size of the mass and/or location of the tumor. In our series, all epithelioid glioneuronal tumors were encountered in the supratentorial space and included pineal, temporal, and extratemporal lobar cerebral hemisphere locations. When large, the tumors demonstrate cystic degeneration and necrosis, hemorrhage, contrast enhancement, and regions of low apparent diffusion coefficient scalars consistent with patterns seen with other high-grade pediatric brain tumors. The tumors also have a propensity to spread into the meninges at presentation and for distant CSF spread on follow-up imaging.

Impact of the size of the lesion in prenatal neural tube defect repair on imaging, neurosurgical and motor outcomes: a retrospective cohort study

OBJECTIVES

(1) To compare brain findings between large and non-large neural tube defect (NTD); (2) to evaluate the impact of large lesion on the surgical parameters; (3) to study any associations between the size of the lesions and brain findings 6 weeks postoperatively and neurological short-term outcomes.

DESIGN

Retrospective cohort study.

SETTING

Texas Children's Hospital, between 2011 and 2018.

POPULATION

Patients who underwent prenatal NTD repair.

METHODS

Large lesion was defined when the lesion's surface was >75th centile of our cohorts' lesions.

MAIN OUTCOME MEASURES

Time of referral: ventriculomegaly and anatomical level of the lesion; surgery: duration and need for relaxing incisions. 6 weeks postoperative: hindbrain herniation (HBH) and ventriculomegaly. After delivery: dehiscence, need for hydrocephalus treatment and motor function.

RESULTS

A total of 99 patients were included, 25 of whom presented with large lesions. Type of lesion and ventriculomegaly were comparable between individuals with large and non-large lesions. Individuals with large lesions were associated with increased need for relaxing incisions by 5.4 times (95% CI 1.3-23.2, P = 0.02). Six weeks postoperatively, having a large lesion decreased by ten times the likelihood of having a postoperative reversal of HBH (odds ratio = 0.1, 95% CI 0.1-0.4, P < 0.01). At birth, larger lesions increased the risk for repair dehiscence by 6.1 times (95% CI 1.6-22.5, P < 0.01) and the risk of dehiscence or leakage of cerebrospinal fluid at birth by 5.5 times (95% CI 1.6-18.9, P < 0.01).

CONCLUSION

Prenatal repair of patients with large NTD presents a lower proportion of HBH reversal 6 weeks after the surgery, a higher risk of dehiscence and a higher need for postnatal repair.

TWEETABLE ABSTRACT

Evaluation of the size of fetal NTD can predict adverse neurological outcomes after prenatal NTD repair.

Pediatric thoracic mass lesions: Beyond the common

Thoracic mass lesions can be categorized as originating in one of the three major compartments: a) chest wall and pleura, b) lung parenchyma and airways, c) mediastinum. While some of these, such as lymphoma, are common in both children and adults, others are rare and unique to childhood. The goal of this review is to familiarize radiologists with unusual but distinctive mass lesions of the pediatric thorax.

Accuracy of MR Imaging for Detection of Sensorineural Hearing Loss in Infants with Bacterial Meningitis

BACKGROUND AND PURPOSE

Bacterial meningitis most commonly affects young children and can result in critical adverse outcomes, including sensorineural hearing loss (SNHL). The purpose of this study is to determine the diagnostic accuracy of MR imaging for predicting the development of SNHL among infants with bacterial meningitis.

MATERIALS AND METHODS

A retrospective review was performed among infants (age <365 days) with bacterial meningitis (n = 115). Independent and consensus blinded review of brain MRIs (n = 239) performed less than 90 days from presentation were conducted. Abnormal appearance of the inner ear was defined as enhancement on postcontrast T1-weighted (T1-weighted+C) sequence and FLAIR hyperintensity. The consensus MR imaging appearance of the inner ear on FLAIR, T1-weighted+C, and combined evaluation was compared with criterion standard audiometric testing to determine the sensitivity and specificity of MR imaging for detecting SNHL.

RESULTS

The mean age at diagnosis of bacterial meningitis was 50.6 days (range, 0-338 days) and 24.3% had SNHL. Sensitivity and specificity was 0.61/0.96, 0.50/0.94, and 0.61/0.94 for T1-weighted+C, FLAIR hyperintensity, and combined evaluation, respectively, for prediction of SNHL. There was excellent interobserver agreement for both the T1-weighted+C and FLAIR sequences and combined evaluation for presence of abnormal enhancement and hyperintense signal, respectively. Factors associated with abnormal MR imaging findings on T1-weighted+C and/or FLAIR in patients with SNHL included low CSF glucose (P = .04, .02) and high CSF protein (P = .04, .03).

CONCLUSIONS

Abnormal enhancement and/or FLAIR hyperintensity of the inner ear demonstrate high specificity and average sensitivity for prediction of SNHL among infants with bacterial meningitis.

Imaging of Paranasal Sinus Infections in Children: A Review

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.

Advanced multimodality neuroimaging of a giant, thrombosed MCA aneurysm complicated by an acute stroke in a pediatric patient

A 17-year-old boy presented to our quaternary hospital because of acute mental status changes following prolonged gastrointestinal illness resulting in dehydration. Neuroimaging studies with computed tomography and magnetic resonance imaging (MRI) revealed a giant thrombosed aneurysm of the left middle cerebral artery (MCA) with acute left MCA stroke. An ischemic penumbra was identified based upon the mismatch between diffusion weighted (DWI) and susceptibility weighted (SWI) MRI matching with the perfusion weighted imaging (PWI). On follow-up MRI, the core of ischemia as identified by DWI progressed into the ischemic penumbra identified by SWI. The patient had permanent moderate right hemiparesis and aphasia on last follow-up. In conclusion, thrombosis is a rare complication of a giant aneurysm in children. Advanced neuroimaging using the combination of DWI and noncontrast enhanced SWI is a valuable alternative or possibly adjunct to PWI to identify tissue at risk for progressing stroke.

MRI Findings in Pediatric Abusive Head Trauma: A Review

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.

Enhancing Brain Lesions during Acute Optic Neuritis and/or Longitudinally Extensive Transverse Myelitis May Portend a Higher Relapse Rate in Neuromyelitis Optica Spectrum Disorders

BACKGROUND AND PURPOSE

Neuromyelitis optica spectrum disorders are inflammatory demyelinating disorders with optic neuritis and/or longitudinally extensive transverse myelitis episodes. We now know that neuromyelitis optica spectrum disorders are associated with antibodies to aquaporin-4, which are highly concentrated on astrocytic end-feet at the blood-brain barrier. Immune-mediated disruption of the blood-brain barrier may manifest as contrast enhancement on brain MR imaging. We aimed to delineate the extent and frequency of contrast enhancement on brain MR imaging within 1 month of optic neuritis and/or longitudinally extensive transverse myelitis attacks and to correlate contrast enhancement with outcome measures.

MATERIALS AND METHODS

Brain MRIs of patients with neuromyelitis optica spectrum disorders were evaluated for patterns of contrast enhancement (periependymal, cloudlike, leptomeningeal, and so forth). The Fisher exact test was used to evaluate differences between the proportion of contrast enhancement in patients who were seropositive and seronegative for aquaporin-4 antibodies. The Mann-Whitney test was used to compare the annualized relapse rate and disease duration between patients with and without contrast enhancement and with and without seropositivity.

RESULTS

Brain MRIs of 77 patients were evaluated; 59 patients (10 males, 49 females) were scanned within 1 month of optic neuritis and/or longitudinally extensive transverse myelitis attacks and were included in the analysis. Forty-eight patients were seropositive, 9 were seronegative, and 2 were not tested for aquaporin-4 antibodies. Having brain contrast enhancement of any type during an acute attack was significantly associated with higher annualized relapse rates (P = .03) and marginally associated with shorter disease duration (P = .05). Having periependymal contrast enhancement was significantly associated with higher annualized relapse rates (P = .03).

CONCLUSIONS

Brain MRIs of patients with neuromyelitis optica spectrum disorders with contrast enhancement during an acute relapse of optic neuritis and/or longitudinally extensive transverse myelitis are associated with increased annual relapse rates.

Pediatric skull fracture diagnosis: should 3D CT reconstructions be added as routine imaging?

OBJECT

The authors compared the efficacy of combining 2D+3D CT reconstructions with standard 2D CT images in the diagnosis of linear skull fractures in children with head trauma.

METHODS

This was a retrospective evaluation of consecutive head CT studies of children presenting with head trauma. Two experienced pediatric neuroradiologists in consensus created the standard of reference. Three readers independently evaluated the 2D CT images alone and then in combination with the 3D reconstructions for the diagnosis of linear skull fractures. Sensitivity and specificity in the diagnosis of linear skull fractures utilizing 2D and 2D+3D CT in combination were measured for children less than 2 years of age and for all children for analysis by the 3 readers.

RESULTS

Included in the study were 250 consecutive CT studies of 250 patients (167 boys and 83 girls). The mean age of the children was 7.82 years (range 4 days to 17.4 years). 2D+3D CT combined had a higher sensitivity and specificity (83.9% and 97.1%, respectively) compared with 2D alone (78.2% and 92.8%, respectively) with statistical significance for specificity (p < 0.05) in children less than 2 years of age. 2D+3D CT combined had a higher sensitivity and specificity (81.3% and 90.5%, respectively) compared with 2D alone (74.5% and 89.1%, respectively) with statistical significance for sensitivity (p < 0.05) in all children.

CONCLUSIONS

In this study, 2D+3D CT in combination showed increased sensitivity in the diagnosis of linear skull fractures in all children and increased specificity in children less than 2 years of age. In children less than 2 years of age, added confidence in the interpretation of fractures by distinguishing them from sutures may have a significant implication in the setting of nonaccidental trauma. Furthermore, 3D CT is available at no added cost, scan time, or radiation exposure, providing trainees and clinicians with limited experience an additional valuable tool for routine imaging of pediatric head trauma.

Longitudinally extensive optic neuritis as an MRI biomarker distinguishes neuromyelitis optica from multiple sclerosis

OBJECTIVE

To differentiate MRI characteristics of optic neuritis associated with neuromyelitis optica (NMO) and relapsing remitting multiple sclerosis (RRMS).

BACKGROUND

Optic neuritis is a common presenting feature of both neuromyelitis optica and multiple sclerosis. Distinguishing between NMO and RRMS is important in guiding treatment, but biomarkers of NMO and MS can be absent early in the disease process. We looked for differences in MRI characteristics of optic neuritis associated with NMO and MS that provide an early clue in the diagnostic workup.

DESIGN/METHODS

We conducted a retrospective analysis of 26 NMO and 26 RRMS patients presenting to the Johns Hopkins Hospital with MRI-confirmed acute optic neuritis. MRIs were assessed to identify the location and longitudinal extent of each contrast enhancing lesion. For the purposes of this study, the optic nerve was divided into intraorbital, canalicular, pre-chiasmal, chiasmal, and optic tract.

RESULTS

There are distinct differences in MRI characteristics between NMO- and RRMS-associated optic neuritis. The majority of NMO lesions were longitudinally extensive measuring at least 17.6mm in length and involving at least three optic nerve segments. At a cutoff of 17.6mm lesion length, the specificity for NMO is 76.9% with a sensitivity of 80.8% and positive likelihood ratio of 3.50. Conversely, MS lesions were more commonly focal in one optic nerve segment localized anteriorly.

CONCLUSIONS

Optic neuritis in NMO has a distinct pattern on MRI as compared with RRMS and can help differentiate these two neuroinflammatory diseases at presentation.

Differentiating neuromyelitis optica from other causes of longitudinally extensive transverse myelitis on spinal magnetic resonance imaging

BACKGROUND

Although spinal magnetic resonance imaging (MRI) findings of neuromyelitis optica (NMO) have been described, there is limited data available that help differentiate NMO from other causes of longitudinally extensive transverse myelitis (LETM).

OBJECTIVE

To investigate the spinal MRI findings of LETM that help differentiate NMO at the acute stage from multiple sclerosis (MS) and other causes of LETM.

METHODS

We enrolled 94 patients with LETM into our study. Bright spotty lesions (BSL), the lesion distribution and location were evaluated on axial T2-weighted images. Brainstem extension, cord expansion, T1 darkness and lesion enhancement were noted. We also reviewed the brain MRI of the patients during LETM.

RESULTS

Patients with NMO had a greater amount of BSL and T1 dark lesions (p < 0.001 and 0.003, respectively). The lesions in NMO patients were more likely to involve greater than one-half of the spinal cord's cross-sectional area; to enhance and be centrally-located, or both centrally- and peripherally-located in the cord. Of the 62 available brain MRIs, 14 of the 27 whom were NMO patients had findings that may be specific to NMO.

CONCLUSIONS

Certain spinal cord MRI features are more commonly seen in NMO patients and so obtaining brain MRI during LETM may support diagnosis.

Achondroplasia in children: correlation of ventriculomegaly, size of foramen magnum and jugular foramina, and emissary vein enlargement

PURPOSE

Achondroplasia is a skeletal dysplasia with diminished growth of the skull base secondary to defective enchondral bone formation. This leads to narrowing of the foramen magnum and jugular foramina, which further leads to ventricular dilatation and prominence of the emissary veins. The primary goal of our study was to determine a correlation between the degree of ventricular dilatation, jugular foramina and foramen magnum narrowing, as well as emissary vein enlargement.

METHODS

Conventional T2-weighted MR images were evaluated for surface area of the foramen magnum and jugular foramina, ventricular dilatation, and emissary veins enlargement in 16 achondroplasia patients and 16 age-matched controls. Ratios were calculated for the individual parameters using median values from age-matched control groups to avoid age as a confounder.

RESULTS

Compared to age-matched controls, in children with achondroplasia, the surface area of the foramen magnum (median 0.50 cm(2), range 0.23-1.37 cm(2) vs. 3.14 cm(2), 1.83-6.68 cm(2), p < 0.001) and jugular foramina (median 0.02 cm(2), range 0-0.10 cm(2) vs. 0.21 cm(2), 0.03-0.61 cm(2), p < 0.001) were smaller, whereas ventricular dilatation (0.28, 0.24-0.4 vs. 0.26, 0.21-0.28, p < 0.001) and enlargement of emissary veins (6, 0-11 vs. 0, p < 0.001) were higher. Amongst the patients, Spearman correlation and multiple regression analysis did not reveal correlation for severity between the individual parameters.

CONCLUSIONS

Our study suggests that in children with achondroplasia, (1) the variation in ventricular dilatation may be related to an unquantifiable interdependent relationship of emissary vein enlargement, venous channel narrowing, and foramen magnum compression and (2) stable ventricular size facilitated by interdependent factors likely obviates the need for ventricular shunt placement.

Hypertrophic olivary degeneration in a child following midbrain tumor resection: longitudinal diffusion tensor imaging studies

Hypertrophic olivary degeneration (HOD) is a dynamic process caused by disruptive lesions affecting components of the Guillain-Mollaret triangle (GMT). The authors applied diffusion tensor imaging (DTI) to investigate longitudinal changes of the GMT components in a child with HOD after neurosurgery for a midbrain tumor. Diffusion tensor imaging data were acquired on a 1.5-T MRI scanner using a balanced pair of diffusion gradients along 20 noncollinear directions 1 day and 3, 6, and 9 months after surgery. Measurements from regions of interest (ROIs) were sampled in the affected inferior olivary nucleus, ipsilateral red nucleus, and contralateral superior and inferior cerebellar peduncles and dentate nucleus. For each ROI, fractional anisotropy and the mean, axial, and radial diffusivities were calculated. In the affected inferior olivary nucleus, the authors found a decrease in fractional anisotropy and an increase in mean, axial, and radial diffusivities 3 months after surgery, while 3 months later fractional anisotropy increased and diffusivities decreased. For all other GMT components, changes in DTI scalars were less pronounced, and fractional anisotropy mildly decreased over time. A detailed analysis of longitudinal DTI scalars in the various GMT components may shed light on a better understanding of the dynamic complex histopathological processes occurring in pediatric HOD over time.

Association between frontal sinus development and persistent metopic suture

BACKGROUND

Frontal sinuses are 2 irregular cavities, placed between 2 lamina of frontal bone. Expansion continues during childhood and reaches full size after puberty. Persistent metopic suture is one of the factors that are related to abnormal frontal sinus development. In this study, we want to discuss about the coexistence of persistent metopic suture and abnormal frontal sinus development using radiological techniques.

MATERIALS AND METHODS

In this retrospectively planned study, images of 631 patients were examined, 217 (34.4%) of them were men and 414 (65.6%) of them were women. Brain computed tomography and magnetic resonance images were retrieved from the electronic archive for analysis.

RESULTS

In this study, frontal sinus development is categorised as right side atrophy, left side atrophy, bilateral atrophy and bilaterally developed sinuses. The presence of metopic suture was accepted as persistent metopic suture. Frontal sinus atrophy was found in 22.7% and persistent metopic sutures were found in 9.7% of overall.

CONCLUSIONS

In this study, no significant results were detected that were relatedto the frontal sinus agenesis or dismorphism associated with persistent metopicsuture. We conclude that, although publications propounding metopism thatleads to abnormal frontal sinus development are present in the literature, noreasonable explanation has been mentioned in these articles; and we believe thatthese findings are all incidental.

Scout view in pediatric CT neuroradiological evaluation: do not underestimate!

PURPOSE

Computed tomography (CT) is an important first-line imaging tool in pediatric neuroradiology. The scout view (SV) is essential for planning the CT study. It is frequently underestimated for its diagnostic value but may harbor important diagnostic clues. We present and discuss the role of SV in the accurate interpretation of pediatric neuroradiological CT studies.

METHODS

CT studies have been collected over 12 months by an experienced pediatric neuroradiologist. Retrospective evaluation of SV and axial CT images was performed in nine children, where the SV gave important diagnostic information. Abnormalities on SV were classified as (1) located outside the field of view as imaged by the cross-sectional CT slices or (2) located in the plane of the cross-sectional CT slices or orthogonal to it.

RESULTS

Five male and four female patients were included. The mean age at CT was 9.86 years (range, 0.75 to 19 years). Abnormalities on SV were located outside of the field of view as imaged by cross-sectional CT slices in six out of nine children and were within the plane of the CT slices or orthogonal to it in three out of nine children.

CONCLUSIONS

A thorough and accurate evaluation of the SV may add valuable, clinically relevant information and should be a routine part of the interpretation of each pediatric neuroradiological CT study.

Posttraumatic carotid artery dissection in children: not to be missed!

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.

Pediatric cerebral stroke: susceptibility-weighted imaging may predict post-ischemic malignant edema

Susceptibility-weighted imaging (SWI) is an advanced MRI technique providing information on the blood oxygenation level. Deoxyhemoglobin is increased in hypoperfused tissue characterized by SWI-hypointensity, while high oxyhemoglobin concentration within hyperperfused tissue results in a SWI iso- or hyperintensity compared to healthy brain tissue. We describe a child with a stroke, where SWI in addition to excluding hemorrhage and delineating the thrombus proved invaluable in determining regions of hyperperfusion or luxury perfusion, which contributed further to the prognosis including an increased risk of developing post-ischemic malignant edema.

Ultrasound elastographic evaluation in the diagnosis of carpal tunnel syndrome: initial findings

The purpose of this study was to investigate ultrasound (US)- and US elastography-detected changes in the median nerve of patients with carpal tunnel syndrome (CTS). Seventy-four wrists of 41 female patients with CTS (mean age, 47.73 ± 11.45 y) and 45 wrists of 24 asymptomatic female controls (mean age, 42.83 ± 10.66 y) were examined with US and US elastography. Electromyography results confirmed the diagnosis of CTS in the patients. The mean median nerve perimeter (MN-P = 15.26 ± 2.18 mm) and median nerve cross-sectional area (MN-CSA = 11.81 ± 4.05 mm²) of patients with CTS were higher than those of controls (12.08 ± 1.54 mm and 7.76 ± 1.40 mm², respectively) (p < 0.05). Mean tissue strain was lower in the patients with CTS (0.094 ± 0.045 than in the controls (0.145 ± 0.068) (p < 0.05). The most sensitive cut-off value for tissue strain was 0.0635, and the most specific was 0.19. US and US elastography, in addition to electromyography, proved to be beneficial in the diagnosis of CTS. US elastography is a new technique that may well find a place in the diagnosis of nerve entrapment syndromes.

Idiopathıc pulmonary artery aneurysm

Pulmonary artery aneurysms are rare pathologic conditions of the thoracic cavity. The ıdiopathic form of the disease is reported very rarely. We report the case of a 16-year-old girl with idiopathic pulmonary artery aneurysm with surface rendered 3-dimensional images of 64-slice computed tomography. A right-sided aortic arch with normal aortic branching was seen. The main pulmonary artery was moderately dilated, and there was aneurysmal dilatation of the right pulmonary artery from its origin to the level of the right descending pulmonary artery. The maximal diameter of the main pulmonary artery was 38 mm; that of the right pulmonary artery was 31 to 34 mm. The left pulmonary artery was of normal diameter (18.5 mm). There was no other accompanying abnormality. Because the patient had no severe symptoms and there were no signs of aneurysmic compression or a shunt, she was scheduled for elective aneurysmectomy.