Intracranial Structure Research Articles

Effects and neural mechanisms of different physical activity on major depressive disorder based on cerebral multimodality monitoring: a narrative review.

Major depressive disorder (MDD) is currently the most common psychiatric disorder in the world. It characterized by a high incidence of disease with the symptoms like depressed mood, slowed thinking, and reduced cognitive function. Without timely intervention, there is a 20-30% risk of conversion to treatment-resistant depression (TRD) and a high burden for the patient, family and society. Numerous studies have shown that physical activity (PA) is a non-pharmacological treatment that can significantly improve the mental status of patients with MDD and has positive effects on cognitive function, sleep status, and brain plasticity. However, the physiological and psychological effects of different types of PA on individuals vary, and the dosage profile of PA in improving symptoms in patients with MDD has not been elucidated. In most current studies of MDD, PA can be categorized as continuous endurance training (ECT), explosive interval training (EIT), resistance strength training (RST), and mind-body training (MBT), and the effects on patients' depressive symptoms, cognitive function, and sleep varied. Therefore, the present study was based on a narrative review and included a large number of existing studies to investigate the characteristics and differences in the effects of different PA interventions on MDD. The study also investigated the characteristics and differences of different PA interventions in MDD, and explained the neural mechanisms through the results of multimodal brain function monitoring, including the intracranial environment and brain structure. It aims to provide exercise prescription and theoretical reference for future research in neuroscience and clinical intervention in MDD.

Eye-brain connections revealed by multimodal retinal and brain imaging genetics

The retina, an anatomical extension of the brain, forms physiological connections with the visual cortex of the brain. Although retinal structures offer a unique opportunity to assess brain disorders, their relationship to brain structure and function is not well understood. In this study, we conducted a systematic cross-organ genetic architecture analysis of eye-brain connections using retinal and brain imaging endophenotypes. We identified novel phenotypic and genetic links between retinal imaging biomarkers and brain structure and function measures from multimodal magnetic resonance imaging (MRI), with many associations involving the primary visual cortex and visual pathways. Retinal imaging biomarkers shared genetic influences with brain diseases and complex traits in 65 genomic regions, with 18 showing genetic overlap with brain MRI traits. Mendelian randomization suggests bidirectional genetic causal links between retinal structures and neurological and neuropsychiatric disorders, such as Alzheimer’s disease. Overall, our findings reveal the genetic basis for eye-brain connections, suggesting that retinal images can help uncover genetic risk factors for brain disorders and disease-related changes in intracranial structure and function.

Optimizing contrast protocol for bone-subtraction CT angiography of intracranial arteries in normal dogs using 160-slice CT.

Bone-subtraction computed tomography angiography (CTA) (BSCTA) is a new technique designed to overcome the limitation of three-dimensional CTA, where the vessels surrounded by bone and calcification can be obscured. An optimal contrast CT protocol for intracranial artery visualization with BSCTA has yet to be established in dogs. The purpose of this study was to determine the optimal contrast protocol of CTA for visualizing intracranial artery using an automatic bone-subtraction technique in dogs. Brain CTA was performed four times for each of nine healthy beagle dogs to cover all the contrast protocols: two different contrast iodine concentrations (300 and 370mgI/mL) and two different contrast media injection rates (2 and 4mL/s). Bone removal post-processing was performed automatically by subtracting the non-enhanced CT data from the contrast CT data using a dedicated workstation. The bone-subtracted intracranial vessels were analysed for quantitative and qualitative evaluation. Quantitative evaluation showed significantly higher CT attenuation values for the group with a 370mgI/mL iodine content at a rate of 4mL/s than the two groups with a 300mgI/mL iodine content at the rates of 2 and 4mL/s (p<0.001). Qualitative assessment revealed significantly higher mean scores for the 370mgI/mL groups than the 300mgI/mL groups and significantly higher mean scores for the 4mL/s groups than the 2mL/s groups (p<0.05). The optimal contrast protocol for BSCTA suggests that high iodine material concentration and high injection rate should be used for strong arterial attenuation and great visualization of the intracranial arterial structure in dogs.

Evaluating the Impact of Intracranial Volume Correction Approaches on the Quantification of Intracranial Structures in MRI: A Systematic Analysis.

In neuroscience, accurately quantifying individual brain regions in large cohorts is a challenge. Differences in intracranial structures can suggest functional differences, but they also reflect the effects of other factors. However, there is currently no standardized method for the correction of intracranial structure measurements. To identify the optimal method to counteract the influence of total intracranial volume (TIV) and gender on the measurement of intracranial structures. Prospective. One hundred forty-one healthy adult volunteers (70 male, mean age 21.8 ± 1.7 years). T1-weighted 3D gradient-echo sequence at 3.0 T. A radiologist with 5 years of work experience screened the raw images to exclude poor-quality images. Freesurfer then performed automated segmentation to obtain measurements of intracranial structures. Male-only, female-only, and TIV-matched sub-samples were created separately. Comparisons between the original data and these sub-samples were used to assess the effects of gender and TIV. Comparison the consistency between TIV-matched sample and corrected data that corrected by four methods: Proportion method, power-corrected proportion method, covariate regression method, and residual method. Cohen's d for examining group distribution disparities, t-tests for probing mean differences, correlation coefficients to assess the relationships between intracranial substructure measurements and TIV. Multiple comparison corrections were applied to the results. The correlation coefficients between TIV and the volumes of intracranial structures ranged from 0.033 to 0.883, with an average of 0.467. Thirty significant volume differences were found among 36 structures in the original sample, while no differences were observed in the TIV-matched sample. Among the four correction methods, the residual method had highest consistency (similarity 94.4%) with the TIV-matched group. The variation in intracranial structure sizes between genders was largely attributable to TIV. The residual method offers a more accurate and effective approach for correcting the effects of TIV on intracranial structures. 2 TECHNICAL EFFICACY: Stage 1.

Clinical effectiveness of 3.0T high resolution magnetic resonance imaging in the diagnosis and prognostic assessment of intracranial atherosclerotic disease

Purpose: To evaluate the usefulness of 3.0T high-resolution magnetic resonance imaging (HR-MRI) in the diagnostic and prognostic assessment of intracranial atherosclerotic diseases. Methods: This retrospective study analyzed the medical data of 100 patients who received intracranial artery 3.0T HR-MRI from November 2020 to November 2021 in Chongqing General Hospital. The patients were divided into ‘symptomatic group’ (n = 60) and ‘asymptomatic group’ (n = 40) based on the occurrence of stroke or transient ischemic attack (TIA) within 4 months. Results: Patients with stroke or TIA within 4 months had a higher risk of hyperlipidemia than those without (p &lt; 0.05). The area of the outer edge of the vessel at the stenosis and the North American Standard for Symptomatic Carotid Endarterectomy Test (NASCET) index in the symptomatic group were significantly higher than in the asymptomatic group (p &lt; 0.001). The symptomatic group documented a significantly higher frequency of fibrous cap rupture (56.17 %) versus the asymptomatic group (25.0 %) (p &lt; 0.05). Conclusion: Thus, 3.0T HR-MRI presents significant advantages in evaluating the intracranial arterial wall structure, plaque, and fibrous cap status, and hence can be used in combination with 3D-TOF-MRA in the diagnosis of intracranial atherosclerosis. This combined strategy provides a basis for the assessment of a patient's ischemic stroke condition.

The insular cortex: a mystery or a verified, documented history. A comprehensive literature review

The insular cortex had been considered a mysterious structure for years and consists of only 2% of all cortical surface area. It is a separate lobe of the cerebral cortex and lies close to the limbic system, which makes it a paralimbic structure, and forms the floor of the lateral sulcus. Despite the myriad of research regarding the insular cortex over the years, it is still considered an obscure and incompletely known structure. Thus, this study aimed to summarize the previous studies regarding the structure, embryology, location, connections, and functions of the insular cortex. Moreover, this review would tend to reorganize the data in a more comprehensive fashion to facilitate reaching the information regarding the insular cortex. The results of the studies were summarized from three perspectives that is neuroanatomy, physiological function, and pathologies commonly affecting the insular cortex. Overall, many textbooks, reviews, case reports, and clinical trials have demonstrated that the insular cortex has a crucial, active, and integrative role in functions throughout the body, from the brain to feeling pain in dorsal part of the foot. Moreover, ischemic stroke cases have demonstrated clearly, how much important the insular cortex is, in normal physiological functioning. More studies, especially clinical trials, should be performed to evaluate the effects of impeding this important intracranial structure.

Frontal lobe development in fetuses with growth restriction by using ultrasound: a case–control study

BackgroundFetal growth restriction (FGR) occurs in up to 10% of pregnancies and is a leading cause of perinatal mortality and neonatal morbidity. Three-dimensional ultrasonography of intracranial structure volume revealed significant differences between fetuses with FGR and appropriate for gestational age (AGA) fetuses. We aimed to compare the frontal lobe development between fetuses with FGR and appropriately grown fetuses and evaluate the impact of fetal circulatory redistribution (FCR) on frontal lobe development in fetuses with FGR.MethodsWe performed a case–control study at our institution from August 2020 to April 2021. The frontal antero-posterior diameter (FAPD) and occipito-frontal diameter (OFD) were measured on the trans-ventricle view and we calculated the Z-scores for FAPD and OFD standardized for gestational age (GA) and transverse cerebellar diameter (TCD) by performing a standard regression analysis followed by weighted regression of absolute residual values in appropriately grown fetuses. We calculated the FAPD/OFD ratio as 100 × FAPD/OFD and FAPD/HC (head circumference) as 100 × FAPD/HC. To compare intracranial parameters, we randomly selected a control group of appropriately grown fetuses matched with the FGR group at the time of ultrasonography. We performed between-group comparisons of the FAPD Z-score, OFD Z-score, FAPD/OFD ratio and FAPD/HC. Similarly, we compared intracranial parameters between fetuses with FGR with and without FCR.ResultsFAPD/OFD ratio was curvilinear related to all the independent variables (GA, BPD, FL, and TCD). Compared with appropriately grown fetuses, fetuses with FGR showed a significantly lower FAPD/OFD ratio, FAPD Z-score, and FAPD/HC. There was no significant difference in the FAPD Z-score, FAPD/OFD ratio, and FAPD/HC between FGR fetuses with and without FCR.ConclusionsThe FAPD/OFD ratio varied during pregnancy, with a mild reduction before and a mild increase after about 33 gestational weeks. Fetuses with FGR showed reduced frontal lobe growth; moreover, fetal frontal lobe development disorders were not significantly different in fetuses with FCR.Trial registrationDate: 09–27-2017; Number: [2017]239.

A new neurosurgical adjustable pressure suction apparatus with a mechanically controlled air inlet: the study of precise regulation and atraumatic suction.

BackgroundAn essential surgical tool in neurosurgery is the suction tube. The skillful and accurate use of a suction tube facilitates the neurosurgical operation.ObjectiveThis study is to verify the practicality of an adjustable pressure suction tube (APS tube) and to explore the ideal APS tube diameter and tip negative pressure for different intracranial structures.MethodsAPS tubes were used to aspirate brain tissues and carotid arteries of rats. Laser speckle contrast imaging (LSCI) was used to record the blood flow velocity (BFV). We measured APS tube diameter, air inlet size, tip negative pressure and central negative pressure and calculated the correlation between them. In our department, intraoperative real-time parameters including APS tube diameter, length, air inlet size, and central negative pressure were recorded, and the tube tip negative pressure suitable for different intracranial structures and parts was calculated.ResultsAll experiments were carried out using APS tubes. Experiments on rats objectively reflected a severe structural damage to the brain and blood vessels by the suction tube, which might even result in an irreversible reduction in blood flow., Rat carotid arteries and brain tissue suffered severe damage when the tip negative pressure exceeded 33.4 ± 1.8 and 29.2 ± 2.0 kPa, respectively. BFV failed to return to the preoperative level 3 min after the operation (p < 0.05), and this decrease was more pronounced when the suction tube diameter was large (p < 0.05). The tip negative pressure was positively and negatively correlated with central negative pressure and the air inlet size, and was independent of APS tube diameter. A total of 50 operations including 39 tumor resection operations and 11 moyamoya disease bypass operations were recorded. Large-diameter APS tubes (3.5 mm) with an closed air inlet were frequently used to maintain a greater tip negative pressure before the incision of dura mater. When important structures such as motor cortex and brainstem were involved, 1.5- or 2.0-mm-diameter APS tubes were mostly used, and an air inlet was opened up to 0.7–2.1 mm to maintain a safe tip negative pressure (7.4–27.9 kPa).ConclusionAPS tubes with a mechanical knob provide stable and precise adjustment of the tip negative pressure, avoiding excessive negative pressure that causes serious damage to the intracranial structure. And, this allows the surgeon to hold the suction tube more freely and operate at any angle with an appropriate fulcrum near the incision to achieve efficient atraumatic suction and enhance surgical safety.

3D-Printed Disease Models for Neurosurgical Planning, Simulation, and Training.

Spatial insight into intracranial pathology and structure is important for neurosurgeons to perform safe and successful surgeries. Three-dimensional (3D) printing technology in the medical field has made it possible to produce intuitive models that can help with spatial perception. Recent advances in 3D-printed disease models have removed barriers to entering the clinical field and medical market, such as precision and texture reality, speed of production, and cost. The 3D-printed disease model is now ready to be actively applied to daily clinical practice in neurosurgical planning, simulation, and training. In this review, the development of 3D-printed neurosurgical disease models and their application are summarized and discussed.

Direct intracranial invasion of eccrine spiradenocarcinoma of the scalp: a case report and literature review

BackgroundEccrine spiradenocarcinoma (SC), also known as malignant eccrine spiradenoma, is a rare malignant cutaneous adnexal neoplasm arising from long-standing benign eccrine spiradenoma. Malignant skin tumors rarely show direct intracranial invasion. However, once the intracranial structure is infiltrated, curative excision with sufficient margins can become extremely difficult, particularly when the venous sinuses are involved. No effective adjuvant therapies have yet been established. Here, we report an extremely rare case of scalp eccrine SC with direct intracranial invasion, which does not appear to have been reported previously.Case presentationAn 81-year-old woman presented with a large swelling on the parietal scalp 12 years after resection of spiradenoma from the same site. The tumor showed intracranial invasion with involvement of the superior sagittal sinus and repeated recurrences after four surgeries with preservation of the sinus. The histopathological diagnosis was eccrine SC. Adjuvant high-precision external beam radiotherapy (EBRT) proved effective after the third surgery, achieving remission of the residual tumor. The patient died 7 years after the first surgery for SC.ConclusionsScalp SC with direct intracranial invasion is extremely rare. Radical resection with tumor-free margins is the mainstay of treatment, but the involvement of venous sinuses makes this unfeasible. High-precision EBRT in combination with maximal resection preserving the venous sinuses could be a treatment option for local tumor control.

Quantification of Intracranial Structures Volume in Fetuses Using 3-D Volumetric MRI: Normal Values at 19 to 37 Weeks' Gestation.

ObjectiveThe purpose of this study is to establish a reference of intracranial structure volumes in normal fetuses ranging from 19 to 37 weeks' gestation (mean 27 weeks).Materials and MethodsA retrospective analysis of 188 MRI examinations (1.5 T) of fetuses with a normal brain appearance (19–37 gestational weeks) from January 2018 to December 2021 was included in this study. Three dimensional (3-D) volumetric parameters from slice-to-volume reconstructed (SVR) images, such as total brain volume (TBV), cortical gray matter volume (GMV), subcortical brain tissue volume (SBV), intracranial cavity volume (ICV), lateral ventricles volume (VV), cerebellum volume (CBV), brainstem volume (BM), and extra-cerebrospinal fluid volume (e-CSFV), were quantified by manual segmentation from two experts. The mean, SD, minimum, maximum, median, and 25th and 75th quartiles for intracranial structures volume were calculated per gestational week. A linear regression analysis was used to determine the gestational weekly age-related change adjusted for sex. A t-test was used to compare the mean TBV and ICV values to previously reported values at each gestational week. The formulas to calculate intracranial structures volume derived from our data were created using a regression model. In addition, we compared the predicted mean TBV values derived by our formula with the expected mean TBV predicted by the previously reported Jarvis' formula at each time point. For intracranial volumes, the intraclass correlation coefficient (ICC) was calculated to convey association within and between observers.ResultsThe intracranial volume data are shown in graphs and tabular summaries. The male fetuses had significantly larger VV compared with female fetuses (p = 0.01). Measured mean ICV values at 19 weeks are significantly different from those published in the literature (p < 0.05). Means were compared with the expected TBV generated by the previously reported formula, showing statistically differences at 22, 26, 29, and 30 weeks' gestational age (GA) (all p < 0.05). A comparison between our data-derived formula and the previously reported formula for TBV showed very similar values at every GA. The predicted TBV means derived from the previously reported formula were all within the 95% confidence interval (CI) of the predicted means of this study. Intra- and inter-observer agreement was high, with an intraclass correlation coefficient larger than 0.98.ConclusionWe have shown that the intracranial structural volume of the fetal brain can be reliably quantified using 3-D volumetric MRI with a high degree of reproducibility and reinforces the existing data with more robust data in the earlier second and third stages of pregnancy.

Retracted] The Study of Expanded Polytetrafluoroethylene New Material in Dural Repair

Dural defect is a common problem in neurosurgery, and the emergence of expanded polytetrafluoroethylene material provides an effective solution for the rehabilitation of artificial blood vessels, heart patches, and other fields. However, studies on the repair of expanded polytetrafluoroethylene in the dura have reported the occurrence of adverse events of cerebrospinal fluid leakage. Therefore, the task of improving expanded polytetrafluoroethylene materials cannot be delayed. In this study, a new composite dural repair material based on expanded polytetrafluoroethylene and polylactic acid‐glycolic acid (expanded polytetrafluoroethylene/polylactic acid‐glycolic acid) was designed and synthesized. The results of in vivo experiments confirmed that the material can fully meet the requirements of repairing the integrity of the dura mater, providing protection for the intracranial structure and rebuilding the extracellular matrix. More importantly, the new composite dural repair material can greatly reduce the incidence of cerebrospinal fluid leakage and inhibit inflammation. Therefore, the application data of this study on New Zealand rabbit species will lay an important foundation for the development of dural repair technology.

THE UTILIZATION OF MAGNETIC RESONANCE IMAGING (MRI) TO DIFFERENTIATE VARIOUS GRADES OF BRAIN TUMOURS

Introduction: Intracranial cancers structure a critical medical problem. The yearly frequency of essential and auxiliary focal sensory system neoplasms goes from 10 to 17 for every 100,000 people. Imaging assumes a significant part in administration and guess of intracranial growths. Magnetic Resonance (MR) imaging has arisen as the imaging methodology most often used to assess intracranial growths and it keeps on having a consistently extending, complex job. On conventional MR imaging Grade I tumors show no edema and enhancement, Grade II tumors show minimal edema and enhancement, Grade III tumors show significant edema and heterogenous enhancement where as Grade IV tumors show significant edema, heterogenous enhancement, hemorrhage and necrosis.&#x0D; Aim: Utility of advanced magnetic resonance imaging sequences in order to differentiate different grades of brain tumors and to evaluate the advance Magnetic Resonance imaging (MRI) Protocol in Gradingbrain tumors both intra axial and extra axial.&#x0D; Results: The present study disclosed that for high grade gliomas Cho/Cr ratios with mean average values 5.13±1.9 ranging from 1.6 to 8.1 and median value of 5.3 and Cho/NAA ratios with mean average values 5.29 ± 1.84 ranging from 1.2 to 7.2 and median value is 6.05. Similarly Cho/Cr ratios for low grade tumors range with mean average values 1.85 ±0.58 ranging from 1.58 to 4.2 and median value of 1.61 and Cho/NAA ratios with mean average values 1.58±0.84 ranging from 1.1 to 5.1 and median value is 1.3. In the study 37 (92.5%) patients show supratentorial location of tumor and 3(7.5%) patients show infratentorial location of tumor.&#x0D; Conclusion: We concluded that by utility of advance MRI imaging can effectively differentiate different grades of brain tumors. The advance MRI imaging methods perfusion study, spectroscopy and Diffuse tensor imaging have significant correlation with degree of malignancy, thus predicting different grades of tumors compared to conventional MRI imaging alone, aiding in management and follow up. So utility of advance MRI imaging sequences in brain tumors imaging provides significant insight regarding malignancy of the tumor apart from conventional imaging. Being these are non invasive techniques and easily available helps in prognostication of patient and thus avoiding unnecessary stereotactic biopsies for low grade gliomas which require follow up. Utility of advance MRI imaging sequences in brain tumor for differentiating different grades of tumors forms an integral part of patient management.

Effect of gravity on brain structure as indicated on upright computed tomography

We aimed to use upright computed tomography (CT) to depict posture-related changes in the brain tissue under normal gravity. Thirty-two asymptomatic volunteers underwent upright CT in the sitting position and conventional CT in the supine position on the same day. We compared the shift of the pineal body, cerebellar tonsil, the length of pituitary stalk, optic nerve sheath area and perimeter (ONSA and ONSP, respectively), and lateral ventricular volume between the supine and sitting positions. We also compared shape changes of the cerebrospinal fluid (CSF) spaces at different sites between both positions. In the sitting position, the pineal body shifted 0.68 ± 0.27 mm in the ventral direction and 0.76 ± 0.24 mm in the caudal direction, the length of pituitary stalk decreased by 1.23 ± 0.71 mm, the cerebellar tonsil descended by 2.10 ± 0.86 mm, the right ONSA decreased by 15.21 ± 6.54%, the left ONSA decreased by 15.30 ± 7.37%, the right ONSP decreased by 8.52 ± 3.91%, the left ONSP decreased by 8.20 ± 4.38%, and the lateral ventricular volume decreased by 5.07 ± 3.24% (all P < 0.001). We also observed changes in the shape of CSF spaces with changes in posture. We concluded that the intracranial structure of healthy subjects and volume of ventricles changed according to posture on Earth.

Vein of Galen Malformation.

* Abbreviations: CPAP: : continuous positive airway pressure Fio2: : fraction of inspired oxygen MFCC: : Maternal Fetal Care Clinic MRA: : magnetic resonance angiography MRI: : magnetic resonance imaging MRV: : magnetic resonance venography PGE1: : prostaglandin E1 VOGM: : vein of Galen malformation A 37-year-old gravida 3, para 1 pregnant woman was referred to the Maternal Fetal Care Center (MFCC) at Boston Children’s Hospital at 36 weeks’ gestation for the finding of vein of Galen malformation (VOGM). The patient’s pregnancy was complicated by gestational diabetes. Her surgical history was notable for adenoidectomy, a previous cesarean section, and dilation and curettage following a spontaneous abortion. Maternal medications included prenatal vitamins and glyburide. Family history was noncontributory. This pregnancy was planned and naturally conceived. The woman received appropriate prenatal care. Noninvasive prenatal screening showed her to be at low risk and cell-free fetal DNA screening was negative. She had a normal anatomy scan at 20 weeks’ gestation. Fetal ultrasonography performed at 36 weeks' gestation for evaluation of fetal growth demonstrated a prominent rounded vascular structure in the quadrigeminal cistern with turbulent flow consistent with a VOGM. Fetal echocardiography at that time revealed dilation of the right atrium and right ventricle with normal biventricular function. There was no evidence of hydrops. Imaging at 37 weeks’ gestation in the Boston Children’s Hospital MFCC included repeat comprehensive fetal echocardiography, fetal ultrasonography, and fetal brain magnetic resonance imaging (MRI). Echocardiography revealed a markedly enlarged right atrium and right ventricle with mild right ventricular dysfunction. Moderate tricuspid regurgitation was noted, the innominate vein was markedly dilated, and the superior vena cava had increased flow. The interventricular septum was dyskinetic, suggesting increased pressure within the right ventricle. There was a patent foramen ovale and a patent ductus arteriosus with right-to-left shunting throughout the cardiac cycle. No evidence of pericardial effusion or hydrops fetalis was seen. Fetal ultrasonography showed a singleton male fetus with biometry measurements, including head circumference, corresponding to estimated gestational age. Amniotic fluid volume was normal. The fetal survey demonstrated a large midline intracranial vascular structure in the expected …

The Effects of Acute Intracranial Pressure Changes on the Episcleral Venous Pressure, Retinal Vein Diameter and Intraocular Pressure in a Pig Model

ABSTRACT Purpose Orbital veins such as the retinal veins and episcleral veins drain into the cavernous sinus, an intracranial venous structure. We studied the effects of acute intracranial pressure (ICP) elevation on episcleral venous pressure, intraocular pressure and retinal vein diameter in an established non-survival pig model. Methods In six adult female domestic pigs, we increased ICP in 5 mm Hg increments using saline infusion through a lumbar drain. We measured ICP (using parenchymal pressure monitor), intraocular pressure (using pneumatonometer), episcleral venous pressure (using venomanometer), retinal vein diameter (using OCT images) and arterial blood pressure at each stable ICP increment. The average baseline ICP was 5.4 mm Hg (range 1.5–9 mm Hg) and the maximum stable ICP ranged from 18 to 40 mm Hg. Linear mixed models with random intercepts were used to evaluate the effect of acute ICP increase on outcome variables. Results With acute ICP elevation, we found loss of retinal venous pulsation and increased episcleral venous pressure, intraocular pressure and retinal vein pressure in all animals. Specifically, acute ICP increase was significantly associated with episcleral venous pressure (β = 0.31; 95% CI 0.14–0.48, p < .001), intraocular pressure (β = 0.37, 95%CI 0.24–0.50; p < .001) and retinal vein diameter (β = 11.29, 95%CI 1.57–21.00; p = .03) after controlling for the effects of arterial blood pressure. Conclusion We believe that the ophthalmic effects of acute ICP elevation are mediated by increased intracranial venous pressure producing upstream pressure changes within the orbital and retinal veins. These results offer exciting possibilities for the development of non-invasive ophthalmic biomarkers to estimate acute ICP elevations following significant neuro-trauma.

Eye Shielding During Head CT Scans: Dose Reduction and Image Quality Evaluation

In this study, we assessed the radiation dose to the lens and the impacts of various eye shields using either a fixed or modulated tube current. Patients undergoing head computed tomography (CT) examinations were recruited, and each was randomly assigned to one of five imaging groups, either without a CT eye shield or with one of two types of shielding and topogram-based tube current modulation (TCM). The radiation dose at the eye lens was estimated using Gafchromic films. All CT images were analyzed for quality in the orbit and brain areas. Two radiologists also qualitatively assessed image artifacts and their impacts on image quality using three-point Likert scales. Both barium sulfate and bismuth-antimony shields significantly reduced radiation dose to the lens (by 28.60%-31.92% and 43.87%-47.00%, respectively) while significantly inducing image artifacts. The image quality of the intraocular structure, but not the intracranial structure, was significantly degraded by shielding. In addition, discriminating the periocular tissues was improved using a bismuth-antimony shield and topogram-based TCM. Compared to fixed tube current, topogram-based TCM provided better signal-to-noise and contrast-to-noise ratios in the intracranial structures when the bismuth-antimony and barium sulfate shields were applied, respectively. Artifacts resulting from the application of eye shields during head CT examinations can be reduced by using topogram-based TCM instead of a fixed tube current. This could be an alternative approach for maintaining image quality in CT scans that do not encompass organ-based TCM.

OP09.09: Normal intracranial structure volume analysis between 11 and 20 weeks of gestation by transvaginal 3D neurosonography

OP09.09: Normal intracranial structure volume analysis between 11 and 20 weeks of gestation by transvaginal 3D neurosonography

Molecular and phenotypic spectrum of Noonan syndrome in Chinese patients.

Noonan syndrome (NS) is a common autosomal dominant/recessive disorder. No large-scale study has been conducted on NS in China, which is the most populous country in the world. Next-generation sequencing (NGS) was used to identify pathogenic variants in patients that exhibited NS-related phenotypes. We assessed the facial features and clinical manifestations of patients with pathogenic or likely pathogenic variants in the RAS-MAPK signaling pathway. Gene-related Chinese NS facial features were described using artificial intelligence (AI).NGS identified pathogenic variants in 103 Chinese patients in eight NS-related genes: PTPN11 (48.5%), SOS1 (12.6%), SHOC2 (11.7%), KRAS (9.71%), RAF1 (7.77%), RIT1 (6.8%), CBL (0.97%), NRAS (0.97%), and LZTR1 (0.97%). Gene-related facial representations showed that each gene was associated with different facial details. Eight novel pathogenic variants were detected and clinical features because of specific genetic variants were reported, including hearing loss, cancer risk due to a PTPN11 pathogenic variant, and ubiquitous abnormal intracranial structure due to SHOC2 pathogenic variants. NGS facilitates the diagnosis of NS, especially for patients with mild/moderate and atypical symptoms. Our study describes the genotypic and phenotypic spectra of NS in China, providing new insights into distinctive clinical features due to specific pathogenic variants.

Obtaining Informed Consent Using Patient Specific 3D Printing Cerebral Aneurysm Model.

ObjectiveRecently, three-dimensional (3D) printed models of the intracranial vascular have served as useful tools in simulation and training for cerebral aneurysm clipping surgery. Precise and realistic 3D printed aneurysm models may improve patients’ understanding of the 3D cerebral aneurysm structure. Therefore, we created patient-specific 3D printed aneurysm models as an educational and clinical tool for patients undergoing aneurysm clipping surgery. Herein, we describe how these 3D models can be created and the effects of applying them for patient education purpose. MethodsTwenty patients with unruptured intracranial aneurysm were randomly divided into two groups. We explained and received informed consent from patients in whom 3D printed models-(group I) or computed tomography angiography-(group II) was used to explain aneurysm clipping surgery. The 3D printed intracranial aneurysm models were created based on time-of-flight magnetic resonance angiography using a 3D printer with acrylonitrile-butadiene-styrene resin as the model material. After describing the model to the patients, they completed a questionnaire about their understanding and satisfaction with aneurysm clipping surgery. ResultsThe 3D printed models were successfully made, and they precisely replicated the actual intracranial aneurysm structure of the corresponding patients. The use of the 3D model was associated with a higher understanding and satisfaction of preoperative patient education and consultation. On a 5-point Likert scale, the average level of understanding was scored as 4.7 (range, 3.0–5.0) in group I. In group II, the average response was 2.5 (range, 2.0–3.0). ConclusionThe 3D printed models were accurate and useful for understanding the intracranial aneurysm structure. In this study, 3D printed intracranial aneurysm models were proven to be helpful in preoperative patient consultation.