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In this work, the effect of vacuum ion-plasma treatment on the wear resistance of the medical screws surface made of VT6 titanium alloy is studied as well as on the mechanical characteristics of the screws in contact with the plate for osteosynthesis. It is shown that the TiN titanium nitride deposition on the screw head increases the surface microhardness by 3 times and also provides lowering the torque during removal of the screw out of the plate.

Background: Rete middle cerebral artery (MCA) is a rare anomaly of the intracranial circulation that mimics congenital Moyamoya disease (MMD). Similar to MMD, it is reported almost exclusively in East-Asian ethnicities. Here, we report 13 patients with rete MCA anomaly from a predominantly non-Asian background in the USA., Methods: Consecutive patients (≥18 years of age) with rete MCA seen in the neurovascular clinic at Columbia University Medical Center (2014-2024) were included. We retrieved demographics, clinical presentation, imaging findings, neurosurgical interventions, and clinical outcomes., Results: 13 patients were identified (mean age 42±21 years, 83.3% female): 7 were White (53.8%), 3 were multiracial Hispanic (23.1%), 2 were South-Asian (15.4%), and 1 was Black (7.7%). Rete MCA was unilateral in all (n=13) and collaterals typical of MMD were absent. MRI vessel wall imaging (n=6) did not show enhancement characteristic of MMD. With serial imaging (n=12), there was no progression or contralateral MCA involvement. Strokes occurred in 5 (38.5%): subarachnoid hemorrhage (n=2), intracerebral hemorrhage (n=2), and ischemic stroke (n=1) from cardioembolism (n=1). 5 (38.5%) underwent neurosurgical bypass (encephaloduroarteriosynangiosis) due to presumed initial diagnosis of MMD (n=4), or for hypoperfusion on imaging related to rete MCA (n=1). Over a 4±3-year mean follow-up, there were no acute neurovascular events., Conclusions: Rete MCA anomaly occurs in non-Asian populations, and is likely benign relative to MMD. The diagnosis should be considered with unilateral, non-progressive findings, and absent MMD-type collaterals. Neurosurgical bypass appears safe, but studies are required to assess the natural history and stroke risk in this condition., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Gliomas and Glioblastomas represent a significant portion of central nervous system (CNS) tumors associated with high mortality rates and variable prognosis. In 2021, the World Health Organization (WHO) updated its Glioma classification criteria, most notably incorporating molecular markers including CDKN2A/B homozygous deletion, TERT promoter mutation, EGFR amplification, + 7/-10 chromosome copy number changes, and others into the grading and classification of adult and pediatric Gliomas. The inclusion of these markers and the corresponding introduction of new Glioma subtypes has allowed for more specific tailoring of clinical interventions and has inspired a new wave of Radiogenomic studies seeking to leverage medical imaging information to explore the diagnostic and prognostic implications of these new biomarkers. Radiomics, deep learning, and combined approaches have enabled the development of powerful computational tools for MRI analysis correlating imaging characteristics with various molecular biomarkers integrated into the updated WHO CNS-5 guidelines. Recent studies have leveraged these methods to accurately classify Gliomas in accordance with these updated molecular-based criteria based solely on non-invasive MRI, demonstrating the great promise of Radiogenomic tools. In this review, we explore the relative benefits and drawbacks of these computational frameworks and highlight the technical and clinical innovations presented by recent studies in the landscape of fast evolving molecular-based Glioma subtyping. Furthermore, the potential benefits and challenges of incorporating these tools into routine radiological workflows, aiming to enhance patient care and optimize clinical outcomes in the evolving field of CNS tumor management, have been highlighted., (© 2024. The Author(s).)

Objectives: Although lower hemoglobin levels associate with worse intracerebral hemorrhage (ICH) outcomes, causal drivers for this relationship remain unclear. We investigated the hypothesis that lower hemoglobin relates to increased hematoma expansion (HE) risk and poor outcomes using human observational data and assessed causal relationships using a translational murine model of anemia and ICH., Methods: ICH patients with baseline hemoglobin measurements and serial CT neuroimaging enrolled between 2010-2016 to a multicenter, prospective observational cohort study were studied. Patients with systemic evidence of coagulopathy were excluded. Separate regression models assessed relationships of baseline hemoglobin with HE (≥33% and/or ≥6mL growth) and poor long-term neurological outcomes (modified Rankin Scale 4-6) after adjusting for relevant covariates. Using a murine collagenase ICH model with serial neuroimaging in anemic vs. non-anemic C57/BL6 mice, intergroup differences in ICH lesion volume, ICH volume changes, and early mortality were assessed., Results: Among 1190 ICH patients analyzed, lower baseline hemoglobin levels associated with increased odds of HE (adjusted OR per -1g/dL hemoglobin decrement: 1.10 [1.02-1.19]) and poor 3-month clinical outcomes (adjusted OR per -1g/dL hemoglobin decrement: 1.11 [1.03-1.21]). Similar relationships were seen with poor 6 and 12-month outcomes. In our animal model, anemic mice had significantly greater ICH lesion expansion, final lesion volumes, and greater mortality, as compared to non-anemic mice., Conclusions: These results, in a human cohort and a mouse model, provide novel evidence suggesting that anemia has causal roles in HE and poor ICH outcomes. Additional studies are required to clarify whether correcting anemia can improve these outcomes., Competing Interests: Potential Conflicts of Interest: none

Background and Objectives: Red blood cell (RBC) concentrations are known to associate with ischemic stroke. It is unclear whether RBC concentrations associate specifically with small vessel disease lacunar infarcts. We investigated the hypothesis that RBC concentrations associate with both chronic covert and acute symptomatic brain MRI lacunar infarcts., Methods: A cross-sectional observational analysis was performed across 2 cohorts with available hematocrit (as the assessment of RBC concentration exposure) and MRI outcome data. The primary setting was a population-based cohort of stroke-free, older adult (>50 years) participants from the Northern Manhattan Study (NOMAS) enrolled between 2003 and 2009. A second replication sample consisted of patients admitted with acute stroke and enrolled into the Columbia Stroke Registry (CSR) between 2005 and 2020. Associations of hematocrit with (1) chronic, covert lacunar infarcts and (2) symptomatic (i.e., acute) lacunar strokes were separately assessed from the NOMAS and CSR cohorts, respectively, using general additive models after adjusting for relevant covariates., Results: Of 1,218 NOMAS participants analyzed, 6% had chronic, covert lacunar infarcts. The association between hematocrit and these covert lacunar infarcts was U-shaped (χ 2 = 9.21 for nonlinear associations; p = 0.03), with people with hematocrit extremes being more likely to have covert lacunar infarcts. Of the 1,489 CSR patients analyzed, 23% had acute lacunar strokes. In this sample, only the relationships of increased hematocrit concentrations and lacunar strokes were replicated (adjusted coefficient β = 0.020; SE = 0.009; p = 0.03)., Discussion: We identified relationships of hematocrit with MRI lacunar infarcts in both stroke-free and ischemic stroke cohorts, respectively. The relationship between increased hematocrit concentrations with lacunar infarcts was replicated in both cohorts. Further studies are required to clarify the mechanisms behind the relationships of hematocrit with ischemic cerebral small vessel disease.

Background: Hemoglobin concentration and diffusion-weighted imaging (DWI) ischemic lesions are separately known to be associated with poor intracerebral hemorrhage (ICH) outcomes. While hemoglobin concentrations have known relationships with ischemic stroke, it is unclear whether hemoglobin concentration is associated with DWI ischemic lesions after ICH. We sought to investigate the hypothesis that hemoglobin concentrations would associate with DWI lesions after ICH and further investigated their relationships with clinical outcomes., Methods: Supratentorial ICH patients enrolled between 2010 and 2016 to a prospective, multicenter, observational cohort study (ERICH study [Ethnic/Racial Variations of Intracerebral Hemorrhage]) were assessed. Patients from this study with baseline, admission hemoglobin, and hospitalization magnetic resonance imaging were analyzed. Hemoglobin was examined as the primary exposure variable defined as a continuous variable (g/dL). Magnetic resonance imaging DWI ischemic lesion presence was assessed as the primary radiographic outcome. Primary analyses assessed relationships of hemoglobin with DWI lesions. Secondary analyses assessed relationships of DWI lesions with poor 3-month outcomes (modified Rankin Scale score, 4-6). These analyses were performed using separate multivariable logistic regression models adjusting for relevant covariates., Results: Of 917 patients with ICH analyzed, mean baseline hemoglobin was 13.8 g/dL (±1.9), 60% were deep ICH, and DWI lesions were identified in 27% of the cohort. In our primary analyses, increased hemoglobin, defined as a continuous variable, was associated with DWI lesions (adjusted odds ratio, 1.21 per 1 g/dL change in hemoglobin [95% CI, 1.07-1.37]) after adjusting for sex, race, ICH severity, time to magnetic resonance imaging, and acute blood pressure change. In secondary analyses, DWI lesions were associated with poor 3-month outcomes (adjusted odds ratio, 1.83 [95% CI, 1.24-2.69]) after adjusting for similar covariates., Conclusions: We identified novel relationships between higher baseline hemoglobin concentrations and DWI ischemic lesions in patients with ICH. Further studies are required to clarify the role of hemoglobin concentration on both cerebral small vessel disease pathophysiology and ICH outcomes.

The effect of thermohydrogen treatment and vacuum ion-plasma nitriding on the determination of the volume and surface structure of ball heads made of Ti-6Al-4V alloy was studied. It was found that the submicrocrystalline structure formed in the head during thermohydrogen treatment makes it possible to achieve hardness values of 39-41 units HRC and a surface roughness of 0.02 μm. It was shown that the creation of a modified layer consisting of ε (TiN) and δ (Ti 2 N) titanium nitrides on the surface of a ball head and the solid interstitial solution of nitrogen in α-titanium makes it possible to completely eliminate material wear when testing for friction on ultra-high-molecular-weight polyethylene. The equivalent analysis was also conducted with a ball head that had been implanted in a human body for 12 years. It was found that the change in the color of the head, from slightly golden after nitriding to metallic, is due to the formation of an oxynitride nanoscale layer on the surface. It was shown that in contrast with films made of titanium oxide, the film developed in this study has high wear resistance.

The natural history and treatment landscape of primary brain tumours are complicated by the varied tumour behaviour of primary or secondary gliomas (high-grade transformation of low-grade lesions), as well as the dilemmas with identification of radiation necrosis, tumour progression, and pseudoprogression on MRI. Radiomics and radiogenomics promise to offer precise diagnosis, predict prognosis, and assess tumour response to modern chemotherapy/immunotherapy and radiation therapy. This is achieved by a triumvirate of morphological, textural, and functional signatures, derived from a high-throughput extraction of quantitative voxel-level MR image metrics. However, the lack of standardisation of acquisition parameters and inconsistent methodology between working groups have made validations unreliable, hence multi-centre studies involving heterogenous study populations are warranted. We elucidate novel radiomic and radiogenomic workflow concepts and state-of-the-art descriptors in sub-visual MR image processing, with relevant literature on applications of such machine learning techniques in glioma management., (© 2021. The Author(s).)

Our paper describes and interprets grain microtexture and microstructure collected from periglacial sediments on the Abalakh High-Accumulation Plain (AHAP) in Central Yakutia. This territory occupies the Lena-Amga Rivers interfluve. In borehole 18/1, five sediment Complexes (I-V) of successive environments were recognized: 1) alluvial in the base of the borehole-Complex I; 2) alluvial-lake-Complex II; 3) lake-complex-Complex III; 4) ice-complex (yedoma)-Complex IV; and finally 5) a Holocene cover-Complex V. Quartz sand-grain and silt-grain microtextural analysis was undertaken in a scanning electron microscope (SEM) and supplemented by mineralogical analyses to reconstruct the sedimentary-accumulation environment, discern the influence of periglacial conditions on the grains, and identify the sediment source(s) for each complex. Based on the results, a conclusion can be reached that the accumulation of Complex I took place as a result of multiple repetitive transportation events recycling the same material and introducing a limited supply of new material into the fluvial environment. Upward in the succession, fluvial-process activities decreased in favour of lake-deposit accumulation. Frozen syngenetic ice-rich silty deposits-yedoma or ice complex-of Complex IV are composed of grains with a precipitated surface, but differ from the underlying deposits in the degree of crusting and mineralogy. Most probably aeolian processes are responsible for their transport. They include a variety of sediments, including older-sourced sediments such as retransported loess and the detritus from mechanical weathering coeval with sediment accumulation. Traces of frost and chemical weathering have been identified on the grain surfaces, the former visible in the form of breakage blocks and conchoidal fracture microtextures and the latter - as surface crusting. However, the frequencies of these microtextures are low, which suggests a relatively high rate of sediment accumulation., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective: To determine the network connections between clinical, cognitive, speech and oculographic parameters in patients with schizophrenia., Material and Methods: The study included 104 patients with schizophrenia and schizophrenia spectrum disorders and 70 healthy subjects. Clinical assessment of the patients was performed using a number of scales: PANSS, CDSS, YMRS, SAS and BAS. Basic cognitive functions were assessed by BACS. Eye movements were recorded using the SMI RED-500 non-invasive eye tracking system. Several experimental paradigms were used - free viewing of animal images with subsequent description of these images, performing progressive saccades in the experimental Go/NoGo scheme, and performing anti-saccades., Results: The severity of clinical symptoms, cognitive impairments, oculomotor parameters and characteristics of speech structure of written speech are largely independent, although not completely isolated from each other. Cognitive and oculomotor parameters have the largest number of connections. In this case, the results of cognitive tests are the central element of the «network» that connects other groups., Conclusion: Further development of the approach should be aimed at studying the influence of node changes on the structure of the network that would potentially allows the identification of the most effective points of application of therapeutic and rehabilitation programs.

Background: Our previous work demonstrating great ease and predictability of cannulation of the major aortic arch branches with an upwardly pointing 3DR catheter, irrespective of aortic arch type, led us to hypothesize that centering or "cresting" of these vessels must occur along the superior most aspect of the aortic arch in a curvilinear fashion., Methods: We retrospectively analyzed 111 computed tomographic scans of the chest and thoracic aorta with intravenous contrast performed at our hospital between April 2011 and May 2012 utilizing TeraRecon image reconstruction software. Four studies were excluded due to poor image quality and/or surgical changes to native aortic architecture., Results: Of the 107 studies included, 104 (97.2%) demonstrated centering of the major aortic arch branches on a curvilinear line "cresting" the superior most aspect of the aortic arch irrespective of arch type. Of the three studies that did not demonstrate this "cresting," two were found to have aberrant right subclavian arteries associated with a type I aortic arch, and one had an aberrant right common carotid associated with a type II aortic arch., Conclusion: Operators engaging major aortic arch branches need to be mindful of the fact that these vessels are indeed centered on a line "cresting" along the superior most aspect of the aortic arch, and any algorithm that, by taking this information into account, reduces catheter manipulation in the aortic arch could potentially result in a reduction in distal atheroembolic events., Competing Interests: Declaration of conflicting interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Neurolymphomatosis is a rare neurological syndrome in lymphomas. It is reported as infiltration of peripheral nerves by lymphoma. It is important to distinguish neurolymphomatosis from other types of neuropathies, particularly infectious and inflammatory conditions. However, it is difficult to isolate a cancer-related inflammatory vasculitis and mononeuritis multiplex without definitive histopathologic examination. In this report, we describe a case of non-Hodgkin's lymphoma involving the peroneal nerve and presenting as neurolymphomatosis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Perfusion CT is being increasingly used as a diagnostic tool for the evaluation of acute ischemic stroke. It can be performed rapidly and aids in the detection of salvageable tissue (penumbra) from the unsalvageable core infarct. The purpose of this article is to provide an overview of the imaging technique, interpretation pearls, and common pitfalls encountered in perfusion CT of the brain., Conclusion: Perfusion CT has proven to be a valuable tool in the diagnosis of acute ischemic stroke. The knowledge provided by these cases will allow the reader not only to confidently identify the presence of acute ischemic stroke, but also to recognize the common pitfalls and limitations of perfusion CT in this setting.

CTP has a growing role in evaluating stroke. It can be performed immediately following NCCT and has advantages of accessibility and speed. Differentiation of salvageable ischemic penumbra from unsalvageable core infarct may help identify patients most likely to benefit from thrombectomy or thrombolysis. Still, CTP interpretation can be complex. We review normal and ischemic perfusion patterns followed by an illustrative series of technical/diagnostic challenges of CTP interpretation in the setting of acute stroke syndromes.

Kikuchi-Fujimoto disease (KFD) is an uncommon disorder that usually presents in young adults of Asian descent with fever and cervical lymphadenopathy. Clinically, this disease is often misdiagnosed as lymphoma or tuberculosis, and biopsy is needed for confirmation. The authors report an unusual case of KFD in a Hispanic male presenting with a subacute subdural hematoma, whose care was complicated by extranodal features not typically associated with KFD. The clinical, histopathologic, and radiographic manifestations of KFD are discussed.

Malignant neoplasia involving contiguous vertebrae and the corresponding intervertebral discs is a rare occurrence that has similar imaging manifestations as pyogenic osteodiscitis. The authors describe the imaging manifestations of two cases of malignant neoplasia mimicking pyogenic osteodiscitis. We present a case of an 83-year-old male with metastatic non-small cell lung carcinoma and an 82-year-old female with a plasmacytoma, both within the thoracic spine. These cases illustrate how the imaging features of pyogenic osteodiscitis may parallel those of malignant neoplasia., (Copyright 2010 Elsevier Inc. All rights reserved.)

Erdheim-Chester disease is a rare form of non-Langerhans histiocytosis presenting in the 5th through 7th decades of life. Osseous manifestations include symmetrical sclerosis of the long bones and, rarely, the spine. Central nervous system disease commonly affects the white matter tracts as well as the orbits, but epidural disease is rare. To the best of the authors' knowledge, simultaneous epidural and skeletal spine disease has not been reported. The MR imaging characteristics of skeletal spine disease have also not been reported. The authors describe the case of an 87-year-old man with both epidural and skeletal spine disease. The clinical characteristics, imaging manifestations, and the histological features are discussed.

Susac syndrome is a rare neurologic disorder first described by Susac et al. in 1979. Clinically, Susac syndrome consists of a triad including encephalopathy, branch retinal artery occlusion, and sensorineural hearing loss. Microinfarction is believed to be the basic histologic feature and MR is considered the best imaging modality. This case documents the typical imaging findings of Susac syndrome, as well as the unique MR imaging finding of cranial nerve enhancement., (Copyright 2010 Elsevier Inc. All rights reserved.)

We present an infant with macrocrania, who initially demonstrated prominent extra-axial fluid collections on sonography of the brain, compatible with benign infantile hydrocephalus (BIH). Because of increasing macrocrania, a follow-up sonogram of the brain was performed; it revealed progressive enlargement of the extra-axial spaces, which now had echogenic debris. Color Doppler US showed bridging veins traversing these extra-axial spaces, so it was initially thought that these spaces were subarachnoid in nature (positive cortical vein sign). However, an arachnoid membrane was identified superior to the cortex, and there was compression of true cortical vessels beneath this dural membrane. An MRI of the brain showed the extra-axial spaces to represent bilateral subdural hematomas. The pathogenesis of spontaneous development of the subdural hematomas, in the setting of BIH, is discussed. We also emphasize that visualizing traversing bridging veins through extra-axial spaces does not necessarily imply that these spaces are subarachnoid in origin.