Experimental congenital diaphragmatic hernia features an alteration of DNA sensing targets cGAS and STING.

BACKGROUND: The pathogenesis of congenital diaphragmatic hernia (CDH) depends on multiple factors. Activation of the DNA-sensing cyclic-GMP-AMP-synthase (cGAS) and Stimulator-of-Interferon-Genes (STING) pathway by double-stranded DNA (dsDNA) links environmental stimuli and inflammation. We hypothesized that nitrofen exposure alters cGAS and STING in human bronchial epithelial cells and fetal rat lungs. METHODS: We used the Quant-IT™-PicoGreen™ assay to assess dsDNA concentration in BEAS-2B cells after 24 h of nitrofen-exposure and performed immunofluorescence of cGAS/STING. We used nitrofen to induce CDH and harvested control and CDH lungs at embryonic day E15, E18 and E21 for cGAS/STING immunofluorescence, RT-qPCR and RNA-Scope™ in-situ-hybridization (E18, E21). RESULTS: We found a higher concentration of dsDNA following nitrofen treatment. Nitrofen-exposure to BEAS-2B cells increased cGAS and STING protein abundance. cGAS abundance was higher in nitrofen lungs at E15, E18 and E21. RNA-Scope in-situ-hybridization showed higher cGAS and STING expression in E18 and E21 lungs. RT-qPCR revealed higher mRNA expression levels of STING in E21 nitrofen-induced lungs. CONCLUSION: Our data suggest that nitrofen-exposure increases dsDNA content which leads to stimulation of the cGAS/STING pathway in human BEAS-2B cells and the nitrofen rat model of CDH. Consequently, DNA sensing and the cGAS-STING-pathway potentially contribute to abnormal lung development in CDH. IMPACT STATEMENT: We found an alteration of DNA sensing targets cGAS and STING in human BEAS-2B cells and experimental congenital diaphragmatic hernia with higher protein abundance and mRNA expression in cells and lung sections of nitrofen-treated rat pups. This is the first study to investigate DNA sensing, a potential link between environmental stimuli and inflammation, in experimental CDH. Our study extends the knowledge on the pathogenesis of experimental CDH.

Pediatric cervical spine clearance after blunt trauma and negative CT: What is the role of MRI?

BACKGROUND AND PURPOSE: The cervical spine in children has marked anatomical and biomechanical differences compared to adults, leading to significantly different patterns and incidence of spinal injury, and consequently to different X-ray and computed tomography (CT) imaging recommendations. Magnetic resonance imaging (MRI) has been validated to clear cervical spine trauma in adults, but not in pediatric patients. We hypothesized that MRI findings have a low probability to change management in children with spine trauma and negative CT findings. MATERIALS AND METHODS: We reviewed records for admitted pediatric patients due to blunt trauma from January 2011 to May 2021, and identified 212 patients who underwent MRI within 3 days of a negative CT. Two neuroradiologists independently reviewed all CT and MRI images for the following categories: fracture, subluxation, spinal canal compromise, ligamentous injury, spinal canal hemorrhage, cord contusion and soft tissue hemorrhage. We identified follow-up MRI examinations as negative or positive for the above categories, and calculated the prevalence of each category as a percentage of cases with negative CT. We also evaluated whether negative and positive MRI groups differed significantly with respect to age and sex of the patients. RESULTS AND CONCLUSIONS: In our study of 212 children with cervical spine trauma and a negative CT, most follow-up MRI scans were found to be negative (79.9 %). Positive MRI findings consisted mainly of ligamentous sprain without disruption (15.1 %). Ligamentous disruption and epidural or soft tissue hemorrhage were found in 4.5 %, and focal cord contusion in 0.5 %. There was no statically significant difference between negative and positive MRI groups with respect to age (P = 0.45) and sex (P = 0.52). CONCLUSION: In our patient group with a negative CT, MRI did not significantly impact management nor contribute to cervical spine clearance in children.

Altered Development of Amygdala-Connected Brain Regions in Males and Females with Autism.

Altered amygdala development is implicated in the neurobiology of autism, but little is known about the coordinated development of the brain regions directly connected with the amygdala. Here we investigated the volumetric development of an amygdala-connected network, defined as the set of brain regions with monosynaptic connections with the amygdala, in autism from early to middle childhood. A total of 950 longitudinal structural MRI scans were acquired from 282 children (93 female) with autism and 128 children with typical development (61 female) at up to four time points (mean ages: 39, 52, 64, and 137 months, respectively). Volumes from 32 amygdala-connected brain regions were examined using mixed effects multivariate distance matrix regression. The Social Responsiveness Scale-2 was administered to assess degree of autistic traits and social impairments. The amygdala-connected network exhibited persistent diagnostic differences (p values ≤ 0.03) that increased over time (p values ≤ 0.02). These differences were most prominent in autistics with more impacted social functioning at baseline. This pattern was not observed across regions without monosynaptic amygdala connection. We observed qualitative sex differences. In males, the bilateral subgenual anterior cingulate cortices were most affected, while in females the left fusiform and superior temporal gyri were most affected. In conclusion, (1) autism is associated with widespread alterations to the development of brain regions connected with the amygdala, which were associated with autistic social behaviors; and (2) autistic males and females exhibited different patterns of alterations, adding to a growing body of evidence of sex differences in the neurobiology of autism.SIGNIFICANCE STATEMENT Global patterns of development across brain regions with monosynaptic connection to the amygdala differentiate autism from typical development, and are modulated by social functioning in early childhood. Alterations to brain regions within the amygdala-connected network differed in males and females with autism. Results also indicate larger volumetric differences in regions having monosynaptic connection with the amygdala than in regions without monosynaptic connection.

A Comprehensive Review of Cross-Sectional Imaging of the Nasolacrimal Drainage Apparatus: What Radiologists Need to Know.

OBJECTIVE. The purpose of this study is to provide a comprehensive review of the radiographic anatomy and cross-sectional imaging findings of the full gamut of nasolacrimal drainage apparatus diseases, highlighting imaging findings from the different nasolacrimal drainage apparatus surgeries, posttreatment complications, and potential imaging pitfalls. CONCLUSION. Radiologists play a critical role in guiding the management of nasolacrimal drainage apparatus diseases and should be familiar with the anatomy and characteristic imaging findings of commonly encountered nasolacrimal drainage apparatus abnormalities and surgeries.

ALS-associated FUS mutations result in compromised FUS alternative splicing and autoregulation.

The gene encoding a DNA/RNA binding protein FUS/TLS is frequently mutated in amyotrophic lateral sclerosis (ALS). Mutations commonly affect its carboxy-terminal nuclear localization signal, resulting in varying deficiencies of FUS nuclear localization and abnormal cytoplasmic accumulation. Increasing evidence suggests deficiencies in FUS nuclear function may contribute to neuron degeneration. Here we report a novel FUS autoregulatory mechanism and its deficiency in ALS-associated mutants. Using FUS CLIP-seq, we identified significant FUS binding to a highly conserved region of exon 7 and the flanking introns of its own pre-mRNAs. We demonstrated that FUS is a repressor of exon 7 splicing and that the exon 7-skipped splice variant is subject to nonsense-mediated decay (NMD). Overexpression of FUS led to the repression of exon 7 splicing and a reduction of endogenous FUS protein. Conversely, the repression of exon 7 was reduced by knockdown of FUS protein, and moreover, it was rescued by expression of EGFP-FUS. This dynamic regulation of alternative splicing describes a novel mechanism of FUS autoregulation. Given that ALS-associated FUS mutants are deficient in nuclear localization, we examined whether cells expressing these mutants would be deficient in repressing exon 7 splicing. We showed that FUS harbouring R521G, R522G or ΔExon15 mutation (minor, moderate or severe cytoplasmic localization, respectively) directly correlated with respectively increasing deficiencies in both exon 7 repression and autoregulation of its own protein levels. These data suggest that compromised FUS autoregulation can directly exacerbate the pathogenic accumulation of cytoplasmic FUS protein in ALS. We showed that exon 7 skipping can be induced by antisense oligonucleotides targeting its flanking splice sites, indicating the potential to alleviate abnormal cytoplasmic FUS accumulation in ALS. Taken together, FUS autoregulation by alternative splicing provides insight into a molecular mechanism by which FUS-regulated pre-mRNA processing can impact a significant number of targets important to neurodegeneration.

Microinjection With Nanoparticles to Deliver Drugs in Prenatal Lung Explants - A Pilot Study for Prenatal Therapy in Congenital Diaphragmatic Hernia.

BACKGROUND: Fetoscopic endoluminal tracheal occlusion (FETO) improves the survival rate in fetuses with severe congenital diaphragmatic hernia (CDH). We hypothesize that prenatal therapies into the trachea during FETO can further improve outcomes. Here, we present an ex vivo microinjection technique with rat lung explants to study prenatal therapy with nanoparticles. METHODS: We used microsurgery to isolate lungs from rats on embryonic day 18. We injected chitosan nanoparticles loaded with fluorescein (FITC) into the trachea of the lung explants. We compared the difference in biodistribution of two types of nanoparticles, functionalized IgG-conjugated nanoparticles (IgG-nanoparticles) and bare nanoparticles after 24 h culture with immunofluorescence (IF). We used IF to mark lung epithelial cells with E-cadherin and to investigate an apoptosis (Active-caspase 3) and inflammatory marker (Interleukin, IL-6) and compared its abundance between the two experimental groups and control lung explants. RESULTS: We detected the presence of nanoparticles in the lung explants, and the relative number of nanoparticles to cells was 2.49 fold higher in IgG-nanoparticles than bare nanoparticles (p < 0.001). Active caspase-3 protein abundance was similar in the control, bare nanoparticles (1.20 fold higher), and IgG-nanoparticles (1.34 fold higher) groups (p = 0.34). Similarly, IL-6 protein abundance was not different in the control, bare nanoparticles (1.13 fold higher), and IgG-nanoparticles (1.12 fold higher) groups (p = 0.33). CONCLUSIONS: Functionalized nanoparticles had a higher presence in lung cells and this did not result in more apoptosis or inflammation. Our proof-of-principle study will guide future research with therapies to improve lung development prenatally. LEVELS OF EVIDENCE: N/A TYPE OF STUDY: Animal and laboratory study.

Axial 3D gradient-echo imaging for improved multiple sclerosis lesion detection in the cervical spinal cord at 3T.

INTRODUCTION: In multiple sclerosis (MS), spinal cord imaging can help in diagnosis and follow-up evaluation. However, spinal cord magnetic resonance imaging (MRI) is technically challenging, and image quality, particularly in the axial plane, is typically poor compared to brain MRI. Because gradient-recalled echo (GRE) images might offer improved contrast resolution within the spinal cord at high magnetic field strength, both without and with a magnetization transfer prepulse, we compared them to T2-weighted fast-spin-echo (T2-FSE) images for the detection of MS lesions in the cervical cord at 3T. METHODS: On a clinical 3T MRI scanner, we studied 62 MS cases and 19 healthy volunteers. Axial 3D GRE sequences were performed without and with off-resonance radiofrequency irradiation. To mimic clinical practice, all images were evaluated in conjunction with linked images from a sagittal short tau inversion recovery scan, which is considered the gold standard for lesion detection in MS. Two experienced observers recorded image quality, location and size of focal lesions, atrophy, swelling, and diffuse signal abnormality independently at first and then in consensus. RESULTS: The number and volume of lesions detected with high confidence was more than three times as high on both GRE sequences compared to T2-FSE (p < 0.0001). Approximately 5 % of GRE scans were affected by artifacts that interfered with image interpretation, not significantly different from T2W-FSE. CONCLUSIONS: Axial 3D GRE sequences are useful for MS lesion detection when compared to 2D T2-FSE sequences in the cervical spinal cord at 3T and should be considered when examining intramedullary spinal cord lesions.

Imaging Cancer in Neuroradiology.

Neuroimaging plays a pivotal role in the diagnosis, management, and prognostication of brain tumors. Recently, the World Health Organization published the fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS5), which places greater emphasis on tumor genetics and molecular markers to complement the existing histological and immunohistochemical approaches. Recent advances in computational power allowed modern neuro-oncological imaging to move from a strictly morphology-based discipline to advanced neuroimaging techniques with quantifiable tissue characteristics such as tumor cellularity, microstructural organization, hemodynamic, functional, and metabolic features, providing more precise tumor diagnosis and management. The aim of this review is to highlight the key imaging features of the recently published CNS5, outlining the current imaging standards and summarizing the latest advances in neuro-oncological imaging techniques and their role in complementing traditional brain tumor imaging and management.

Skull base infections, their complications, and management.

OBJECTIVE: Our review aims to summarize the current literature on skull base infections (SBIs) and retrospectively analyze any such cases encountered at our institution. DESIGN: A literature search was conducted using online databases PubMed, MEDLINE, and ResearchGate with the terms "skull base osteomyelitis," "temporal bone osteomyelitis," "skull base infections," "necrotizing otitis media," and "SBO". References from the resulting manuscripts were reviewed for relevant articles. A search of our electronic health records using the same key terms was also performed to identify patients with a tissue biopsy-confirmed diagnosis of skull base infections. Patients with an indeterminate diagnosis or inaccessible/poor imaging were excluded. SETTING: A level one trauma and major tertiary academic medical center. PARTICIPANTS: All patients treated at the University of California Davis Health System with a confirmed diagnosis of skull base infections from January 2005 to November 2020. MAIN OUTCOME MEASURES: Imaging results, symptoms, treatment, morbidity, and mortality. RESULTS: Our literature search yielded 59 articles ranging from 1982 to 2021. A retrospective search of our electronic health records identified two cases of skull base infections. CONCLUSION: Skull base infections have no pathognomonic findings. A multimodal approach with computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine is necessary to characterize the disease process in addition to a biopsy for definitive diagnosis. Other diagnoses can mimic SBI on imaging, such as nasopharyngeal carcinoma and inflammatory pseudotumor. Culture-guided antimicrobial treatment and surgery are mainstay therapies. Other adjuvant strategies currently lack the robust evidence necessary to characterize their risks and benefits.

Autoimmune disease of head and neck, imaging, and clinical review.

Autoimmune disease of the head and neck (H&N) could be primary or secondary to systemic diseases, medications, or malignancies. Immune-mediated diseases of the H&N are not common in daily practice of radiologists; the diagnosis is frequently delayed because of the non-specific initial presentation and lack of familiarity with some of the specific imaging and clinical features. In this review, we aim to provide a practical diagnostic approach based on the specific radiological findings for each disease. We hope that our review will help radiologists expand their understanding of the spectrum of the discussed disease entities, help them narrow the differential diagnosis, and avoid unnecessary tissue biopsy when appropriate based on the specific clinical scenarios.

Multimodal neuroimaging in pediatric type 1 diabetes: a pilot multisite feasibility study of acquisition quality, motion, and variability.

Type 1 diabetes (T1D) affects over 200,000 children and is associated with an increased risk of cognitive dysfunction. Prior imaging studies suggest the neurological changes underlying this risk are multifactorial, including macrostructural, microstructural, and inflammatory changes. However, these studies have yet to be integrated, limiting investigation into how these phenomena interact. To better understand these complex mechanisms of brain injury, a well-powered, prospective, multisite, and multimodal neuroimaging study is needed. We take the first step in accomplishing this with a preliminary characterization of multisite, multimodal MRI quality, motion, and variability in pediatric T1D. We acquire structural T1 weighted (T1w) MRI, diffusion tensor MRI (DTI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS) of 5-7 participants from each of two sites. First, we assess the contrast-to-noise ratio of the T1w MRI and find no differences between sites. Second, we characterize intervolume motion in DTI and fMRI and find it to be on the subvoxel level. Third, we investigate variability in regional gray matter volumes and local gyrification indices, bundle-wise DTI microstructural measures, and N-acetylaspartate to creatine ratios. We find the T1-based measures to be comparable between sites before harmonization and the DTI and MRS-based measures to be comparable after. We find a 5-15% coefficient of variation for most measures, suggesting ~150-200 participants per group on average are needed to detect a 5% difference across these modalities at 0.9 power. We conclude that multisite, multimodal neuroimaging of pediatric T1D is feasible with low motion artifact after harmonization of DTI and MRS.

MR enterography findings of inflammatory bowel disease in pediatric patients.

OBJECTIVE: The purpose of this article is to illustrate and describe the characteristic MR enterography findings in children with inflammatory bowel disease (IBD) and to present MR enterography as the first-choice imaging modality in this setting. CONCLUSION: Given its high sensitivity and specificity for IBD and lack of ionizing radiation, MR enterography is a valuable technique for examining children with IBD.

Automated vs. conventional tractography in multiple sclerosis: variability and correlation with disability.

Diffusion-tensor-imaging fiber tractography enables interrogation of brain white matter tracts that subserve different functions. However, tract reconstruction can be labor and time intensive and can yield variable results that may reduce the power to link imaging abnormalities with disability. Automated segmentation of these tracts would help make tract-specific imaging clinically useful, but implementation of such segmentation is problematic in the presence of diseases that alter brain structure. In this work, we investigated an automated tract-probability-mapping scheme and applied it to multiple sclerosis, comparing the results to those derived from conventional tractography. We found that the automated method has consistently lower scan-rescan variability (typically 0.7-1.5% vs. up to 3% for conventional tractography) and avoids problems related to tractography failures within and around lesions. In the corpus callosum, optic radiation, and corticospinal tract, tract-specific MRI indices calculated by the two methods were moderately to strongly correlated, though systematic, tract-specific differences were present. In these tracts, the two methods also yielded similar correlation coefficients relating tract-specific MRI indices to clinical disability scores. In the optic tract, the automated method failed. With judicious application, therefore, the automated method may be useful for studies that investigate the relationship between imaging findings and clinical outcomes in disease.

A topology-preserving approach to the segmentation of brain images with multiple sclerosis lesions.

We describe a new fully automatic method for the segmentation of brain images that contain multiple sclerosis white matter lesions. Multichannel magnetic resonance images are used to delineate multiple sclerosis lesions while segmenting the brain into its major structures. The method is an atlas-based segmentation technique employing a topological atlas as well as a statistical atlas. An advantage of this approach is that all segmented structures are topologically constrained, thereby allowing subsequent processing such as cortical unfolding or diffeomorphic shape analysis techniques. Evaluation with both simulated and real data sets demonstrates that the method has an accuracy competitive with state-of-the-art MS lesion segmentation methods, while simultaneously segmenting the whole brain.

Neuroimaging and neuropsychological follow-up study in a pediatric brain tumor patient treated with surgery and radiation.

Intracranial tumors are the most common neoplasms of childhood, accounting for approximately 20% of all pediatric malignancies. Radiation therapy has led directly to significant increases in survival of children with certain types of intracranial tumors; however, given the aggressive nature of this therapy, children are at risk for exhibiting changes in brain structure, neuronal biochemistry, and neurocognitive functioning. In this case report, we present neuropsychological, magnetic resonance imaging, proton magnetic resonance spectroscopic imaging, and diffusion tensor imaging data for two adolescents (one patient with ependymal spinal cord tumor with intracranial metastases, and one healthy, typically developing control) from three time points as defined by the patient's radiation schedule (baseline before the patient's radiation therapy, 6 months following completion of the patient's radiation, and 27 months following the patient's radiation). In the patient, there were progressive decreases in gray and white matter volumes as well as early decreases in mean N-acetyl aspartate/choline (NAA/Cho) ratios and fractional anisotropy (FA) in regions with normal appearance on conventional MRI. At the last follow-up, NAA/Cho and FA tended to change in the direction to normal values in selected regions. At the same time, the patient had initial reduction in language and motor skills, followed by return to baseline, but later onset delay in visuospatial and visual perceptual skills. Results are discussed in terms of sensitivity of the four techniques to early and late effects of treatment, and avenues for future investigations.

Medulloblastoma: atypical CT and MRI findings in children.

Posterior fossa mass lesions in children usually present a diagnostic challenge despite their high frequency and the limited number of differential diagnostic possibilities. Consideration of medulloblastoma within the differential diagnosis of such lesions mandates an aggressive surgical approach as residual tumor is a known risk factor for poor prognosis. Preoperative imaging of the entire neuroaxis is critical given the high propensity of drop metastases. In this pictorial presentation, we review and demonstrate less common features of medulloblastomas to facilitate diagnosis in challenging cases.

MR imaging findings of a rare pediatric parotid tumor: Mammary analogue secretory carcinoma.

We present magnetic resonance imaging findings of an 11-year-old girl with a mammary analogue secretory carcinoma (MASC) of the parotid gland. MASC is a recently described tumor of the salivary glands that is genetically and histologically similar to secretory breast carcinoma. To date, a few cases have been reported in the pediatric population, with limited information of its imaging characteristics. We suggest that decreased T2 signal of the solid component of the MASC representing cellular components with associated complex cystic parts may be a helpful imaging finding and can make a substantial contribution in differentiating this new entity from other rare pediatric parotid masses. Although there are no characteristic imaging findings at this time, MASC should be considered in the differential of salivary gland tumors in the pediatric population as well.

Bilateral external auditory canal masses following repair of ruptured abdominal aortic aneurysm and open decompressive exploratory laparotomy for compartment syndrome: A rare case of spontaneous bilateral otorrhagia.

Very few cases of spontaneous otorrhagia (SO) following nonotolaryngologic surgery have ever been reported in surgical literature and none in radiographic. Of the surgical cases reported, SO occurred in the perioperative period following laparoscopic surgeries in the Trendelenburg position. We report the first case of spontaneous bilateral otorrhagia which presented as bilateral external auditory canal masses following endovascular surgery and open decompressive laparotomy in a 60-year-old male with a prior history of hypertension and smoking. We seek to inform radiologists that SO can present on neck imaging as external auditory canal masses as a complication of nonotolaryngologic surgery away from the imaged field of view.

Neuroimaging findings in a child with dumbbell-shaped frontosphenoidal dermoid cyst presenting as preseptal cellulitis.

We report the CT and MRI findings in a 5-year-old girl with histologically proven frontosphenoidal dumbbell-shaped dermoid cyst with sinus tracts in the frontal bone extending to the dura. Although the most common location for dermoid cyst in the head and neck is at the frontosphenoidal region, presentation with a tract extending deep to underlying bone or the intracranium is rare for this location. Complete surgical excision has been widely accepted as the basic treatment for dermoid cyst. However, the relatively extensive nature of such surgical interventions may be associated with serious risks to both visual acuity and cosmesis. From a clinical viewpoint, even if these are rare cases, radiological imaging is crucial for orienting the deeper extension of the lesion for presurgical planning.