Exophthalmometry is an essential component in the determination of changes in the position of the eyeball and is influenced by various factors. This paper analyzes the usefulness of the Ex/Axl ratio, meaning the ratio of anterior exophthalmos to bulbar axial length, in relation to the position of the eye in the orbit in order to take better account the anthropometric characteristics of individual exophthalmometry measurements. MRI scans of the head in the population-based cohorts SHIP-START-2 and SHIP-TREND-0 were used to perform anterior and posterior exophthalmometry as well as bulbar axial length measurements in 2083 subjects between 21 and 89 years of age. After excluding non-measurable images, 1926 subjects were included in the data analysis. We established sex- and age specific reference limits for the Ex/Axl ratio and the exophthalmometry parameters. If the Ex/Axl ratio was above 85.3% in men and above 79.7% in women, this indicated pathological exophthalmos in our study. Exophthalmometry should be considered on a sex-specific basis since there are clear differences in the measurements between men and women. MRI images of the head were used to determine separate reference values for men and women, which may be useful in clinical practice. Furthermore, our study highlights the clinical significance of measuring the individual bulbar axial length and anthropometric data for the personalized assessment of exophthalmos. In this context, the newly introduced Ex/Axl ratio may be a useful tool for a better differentiation between pseudoexophthalmos and clinically relevant exophthalmos.

In this study we introduce automated 3D segmentation of the healthy human adult eye and orbit from Magnetic Resonance Images, to improve ophthalmic diagnostics and treatments. Past efforts have primarily focused on small sample sizes and varied imaging modalities. Here, we leverage a large-scale dataset of T1-weighted MRI of 1245 subjects and the deep learning-based nnU-Net for MR-Eye segmentation tasks. The results showcase robust and accurate 3D segmentation of lens, globe, optic nerve, rectus muscles, and orbital fat. We also present the automated estimation of key ophthalmic morphometry biomarkers such as axial length and volumetry, while benchmarking correlations between body mass index and eye structure volumes. Quality control protocols are introduced through the pipeline to ensure the reliability of the segmented large-scale data, further enhancing the applicability of our algorithm in clinical research. As a major outcome we provide the first large-scale unbiased eye atlases (female, male, and combined) towards standardization of spatial normalization tools for MR-Eye.

Background/Objectives. Automated lateral ventricle volumetry is increasingly used in population-based neuroimaging, but correlation between methods does not establish agreement of absolute volumes. We quantified agreement and calibration between FreeSurfer and a visually quality-controlled FSL/FAST-ALVIN lateral ventricle workflow within the Study of Health in Pomerania (SHIP). Methods. This cross-sectional agreement-and-calibration study included 2988 SHIP participants with visually accepted FSL/FAST-ALVIN total lateral ventricle volumes; paired FreeSurfer data were available for 1913 participants. FSL/FAST-ALVIN was treated as the study reference scale rather than biological ground truth. Agreement was assessed using Pearson and Spearman correlations, Bland-Altman analysis, log-ratio agreement, Lin's concordance correlation coefficient, and a two-way mixed-effects single-measure absolute agreement intraclass correlation coefficient. Directional calibration models predicted FSL/FAST-ALVIN volume from FreeSurfer volume and were internally validated using 2000 bootstrap resamples. Results. In the paired sample, volumes were almost perfectly associated (Pearson r = 0.9978; Spearman ρ = 0.9974), but FreeSurfer yielded systematically lower values (mean FreeSurfer-minus-FSL bias, -3.02 mL; 95% limits of agreement, -4.52 to -1.53 mL; geometric mean FreeSurfer/FSL ratio, 0.844). Lin's concordance coefficient and the absolute agreement ICC were both 0.9598. Calibration was strong but workflow-specific: FSL/FAST-ALVIN volume = 2.611 + 1.0210 × FreeSurfer volume (R2 = 0.9955; optimism-corrected RMSE = 0.732 mL). Conclusions. FreeSurfer and visually quality-controlled FSL/FAST-ALVIN preserved participant ranking extremely well but were not directly interchangeable as absolute measurements. Cross-workflow comparisons require explicit method reporting, formal agreement analysis, and calibration to the intended measurement scale; the equation should not be used as a universal conversion formula outside comparable acquisition, segmentation, QC and software settings.

Neurovascular compression (NVC) of the rostral ventrolateral medulla (RVLM) is discussed as a cause for arterial hypertension (aHT). This study aimed to investigate the prevalence and the extent of NVC of the RVLM and to evaluate association with aHT in Germany. In a population-based sample of 3044 subjects of the “Study of Health in Pomerania” (SHIP), brain imaging including T1-weighted MPRAGE with 1 mm isotropic voxel-size and time-of-flight angiography was obtained. We determined prevalence and extent of neurovascular contact or NVC grade I, II or III of the RVLM in all individuals. Statistical analysis included descriptive and comparative cohort characterisation, as well as contingency analysis for NVC and aHT. Prevalence of neurovascular contact and NVC grades I-III was 12.6

Evans’ Index (EI) and Frontal and Occipital Horn Ratio (FOHR) are routinely used in screening for enlargement of the ventricular system. However, both lack epidemiological definition of normal values in adults. In a representative, randomized sample of adult normal population in Germany we studied the correlation of lateral ventricle volumes with EI and FOHR to evaluate the performance of pre-established cutoff values of EI > 0.3 and FOHR > 0.37, and to introduce age- and sex-specific thresholds, which for FOHR do not yet exist in adults. In a population-based sample of 3058 subjects of the “Study of Health in Pomerania” (SHIP), aged 21–90 years, brain imaging with T1 weighted MPRAGE with 1 mm isotropic voxel-size was obtained. We semiautomatically determined the volumes of the lateral ventricles and manually performed measurements to calculate EI and FOHR for every individual. Besides descriptive statistics, ROC analyses were carried out to determine test performance of both parameters. Negative and positive predictive values were derived from contingency analyses. Average values were 0.257 ± 0.025 for EI and 0.363 ± 0.024 for FOHR, with sex- and age-depending differences. Using the established cut-off value of EI > 0.3, this index achieved high specificity of 97.1

The Alberta Stroke Program Early CT Score (ASPECTS) and advances in CT reconstruction play important roles in the neurodiagnostic workflow. This study examines the effect of these reconstruction techniques on automated ASPECTS. In this retrospective study, 173 patients (median age 79 years, 39

A standardized, population-based three-dimensional (3D) computer-aided design (CAD) model of the intracranial arterial system was developed from time-of-flight magnetic resonance angiography (TOF-MRA) data of the Study of Health in Pomerania (SHIP) cohort, tailored for realistic simulation and experimental neurovascular applications. An averaged intracranial TOF-MRA dataset generated from 4308 individual whole-body MRI examinations of the SHIP cohort was used as the anatomical basis. Intracranial arteries were segmented using 3D Slicer with Frangi-based vessel enhancement, semi-automatic region-growing, and manual refinement to obtain continuous vascular masks. Centerlines were extracted with VMTK (Vascular Modelling Toolkit), and vessel radii were computed via distance mapping. The resulting centerline and radius data were imported into a CAD environment (Creo Parametric) to reconstruct smooth vessel centerlines, generate circular cross-sections, and create a lofted three-dimensional lumen model, which was converted into a hollow geometry with a uniform wall thickness and exported as an STL file for 3D printing. The proposed workflow yielded a geometrically consistent, hollow 3D model of the central intracranial arteries, representing a population-averaged arterial anatomy with smooth vessel courses, gradual diameter transitions, and a closed, continuous wall. The CAD model could be successfully manufactured as a physical 3D-printed phantom and provides a stable, reproducible test environment for digital and in vitro investigations of neurovascular interventions under standardized anatomical conditions. Population-based TOF-MRA data can be transformed into a technically robust and anatomically meaningful intracranial reference model suitable for CAD-based simulation and additive manufacturing. The resulting 3D CAD geometry serves as a reusable reference for comparative studies, methodological validation, early-stage device development, and training in endovascular neurosurgery, without aiming to replace patient-specific models. Time-of-flight magnetic resonance angiography (TOF-MRA)–based vascular modeling. Population-averaged intracranial arterial anatomy. Three-dimensional (3D) cerebrovascular reconstruction. Image-based vessel segmentation and centerline extraction. Computational modeling of cerebral blood vessels.

Background: Radiomic analyses have been extensively explored in oncologic imaging and more recently in neuroimaging. However, radiomic characterization of the crystalline lens using computed tomography has not yet been systematically investigated. Methods: In this retrospective study, semiautomatic segmentation of the eye lens on orbital CT was performed on 112 patients (mean age 48 ± 20 years, 38% female). After radiomics feature extraction, a Boruta feature selection approach based on the random forest algorithm was applied to select the most relevant radiomics features. Severity of white matter lesions were graded according to the Fazekas scale for each patient on axial non-contrast head CT. Results: In total, 17 important features were associated with age-related changes in the eye lens and three important radiomic features for the differentiation between patients with a Fazekas score > 1 and a control group. Significantly higher values were found in patients with a Fazekas score > 1 compared to the control group regarding all three features, “ClusterShade”, “Skewness” and “DifferenceVariance” (p = 0.0006, 0.0023 and 0.0376, respectively), which are all measures of heterogeneity. No important radiomic features of the eye lens were confirmed between patients with and without hypertension. Conclusions: To the best of our knowledge, this is the first study to use CT-based radiomic analysis of the crystalline lens to detect differences among demographic or clinical groups with small vessel disease. The present results might help to expand the range of applications of radiomics regarding ophthalmic (patho-)physiology and suggest a possible new biomarker for systemic vascular diseases.

Unresectable WHO grade II astrocytomas require continuous imaging surveillance. To evaluate whether sodium MRI (23Na-MRI) adds diagnostic value to multiparametric MRI and helps predict progressive disease (PD), patients monitored under a “watchful waiting” strategy were repeatedly examined. Overall, 18 patients with biopsy-proven WHO grade II astrocytoma (10 female, mean age 42 ± 15 years) were prospectively included after baseline imaging. The imaging protocol comprised morphological MRI (T2 TSE, T2 FLAIR, pre- and post-contrast T1 SE), DSC perfusion MRI (n = 17), and 23Na-MRI (n = 9) at 3 T. At baseline, evaluable 23Na-MRI was available for six patients. The Response Assessment in Neuro-Oncology criteria were used to define PD. Semiquantitative ROI analysis was performed on DSC- and 23Na-MRI. Data were analyzed using the Cox regression model. In 14 patients (78

Objective: The current study aims to investigate whether objective measurements of the cochlear nerve (CN), derived from preoperative MRI images, correlate with postoperative speech perception in CI patients. Study Design: Retrospective cohort study. Setting: University Medical Center, tertiary academic referral center. Patients: Patients undergoing a cochlear implant surgery including MED-EL (Synchrony 2, FLEX electrode series; MED-EL, Innsbruck, Austria) Cochlear (slim straight electrodes; Cochlear Ltd., Sydney, Australia), Advanced Bionics (HiRes Ultra 3D CI, HiFocus SlimJ electrodes; Sonova, Z & uuml;rich, Switzerland), and Oticon (Neuro Zti EVO; Oticon A/S, Sm & oslash;rum, Denmark) between 2020 and 2023. Intervention: Preoperative MRI images were utilized to measure the volume of the modiolus (VM), the cross-sectional areas of the CN (ACN), and for normalization, the area of the facial nerve (AFN) and the area of the internal ear canal (AIEC). Postoperative speech perceptions were assessed through word recognition scores (WRS) at several stages following the first fitting (FF) of the CI processor: immediately after FF, 1 month, 3 months, and 6 months after FF. Main Outcome Measures: Sixty-eight patients were enrolled in this study. A statistically significant positive correlation between the ratio between ACN and AFN (ACN/AFN) and WRSFF was identified (R = 0.36, p < 0.003). However, this correlation disappeared in subsequent follow-up tests. Moreover, upon grouping patients based on their degree of asymmetrical hearing loss, it was observed that the correlation was primarily driven by patients with moderate to severe asymmetrical hearing loss (AHLm) on the contralateral side (R = 0.62, p = 0.0003).Conclusion: The present results suggest that assessing the size of the CN through MRI has limited predictive utility for postoperative speech perceptions during CI consultations. This limitation seems to be particularly relevant for AHLm patients and is confined to the initial activation period.

This study addresses the need for accurate 3D segmentation of the human eye and orbit from MRI to improve ophthalmic diagnostics. Past efforts focused on small sample sizes and varied imaging methods. Here, two techniques (atlas-based registration and supervised deep learning) are tested for automated segmentation on a large T1-weighted MRI dataset. Results show accurate segmentations of the lens, globe, optic nerve, rectus muscles, and fat. Additionally, the study automates the estimation of axial length, a key biomarker. ### Competing Interest Statement The authors have declared no competing interest. Fondation Gelbert, Geneva, Switzerland

Differentiation between saltwater and freshwater immersion as well as estimating the corpse's time in water can be challenging. We aimed to establish and examine the feasibility of a novel approach based on sodium magnetic resonance imaging (23Na MRI) of the eye to facilitate noninvasive sodium quantification. Enucleated porcine eyes were immersed in NaCl 0.9%, NaCl 3.0%, NaCl 5.85%, distilled water (DW) or lake water (LW) at different time intervals, followed by 23Na 7-T MRI sodium quantification. After 6 h of immersion, a significant difference in vitreous body (VB) sodium concentration was found for NaCl 5.85% versus DW or LW (p ≤ 0.019). After 24 and 48 h of immersion, a significant difference in VB sodium concentration was found for NaCl 5.85% versus DW, LW, NaCl 3.0% or NaCl 0.9%, as well as for NaCl 3.0% versus DW, LW or NaCl 0.9% (p ≤ 0.001). After 24 h of immersion, lens sodium concentration showed a significant difference for NaCl 5.85% versus DW, LW, NaCl 3.0% or NaCl 0.9% (p ≤ 0.009); after 48 h of immersion, for NaCl 5.85% versus DW, LW, NaCl 3.0% or NaCl 0.9% (p ≤ 0.001), as well as for NaCl 3.0% versus DW, LW or NaCl 0.9% (p ≤ 0.007). For VB, sodium concentration changes over immersion time, and exponential curves were fitted to the data. Using 23Na MRI in ex vivo porcine eyes with different immersion times in various saltwater concentrations and freshwater equivalents allowed noninvasive quantification of VB and lens sodium concentrations. Although not a substitute for autopsy, 23Na MRI assessment of VB and lens sodium concentrations may provide biochemical support in suspected drowning, especially in cases where an internal examination of the body is not authorized or where objections to autopsy are upheld. Postmortem porcine eyes with different immersion times in saltwater and freshwater. Noninvasive quantification of vitreous body and lens sodium concentrations with 23Na MRI. Exponential time course of vitreous body sodium concentration in saltwater and freshwater.

Quantitative susceptibility mapping (QSM) and transcranial sonography (TCS) offer proximal evaluations of iron load in the substantia nigra. Our prospective study aimed to investigate the relationship between QSM and TCS measurements of nigral iron content in patients with Parkinson’s disease (PD). In secondary analyses, we wanted to explore the correlation of substantia nigra imaging data with clinical and laboratory findings. Eighteen magnetic resonance imaging and TCS examinations were performed in 15 PD patients at various disease stages. Susceptibility measures of substantia nigra were calculated from referenced QSM maps. Echogenicity of substantia nigra on TCS was measured planimetrically (echogenic area) and by digitized analysis (echo-intensity). Iron-related blood serum parameters were measured. Clinical assessments included the Unified PD Rating Scale and non-motor symptom scales. Substantia nigra susceptibility correlated with echogenic area (Pearson correlation, r = 0.53, p = 0.001) and echo-intensity (r = 0.78, p < 0.001). Individual asymmetry indices correlated between susceptibility and echogenic area measurements (r = 0.50, p = 0.042) and, more clearly, between susceptibility and echo-intensity measurements (r = 0.85, p < 0.001). Substantia nigra susceptibility (individual mean of bilateral measurements) correlated with serum transferrin saturation (Spearman test, r = 0.78, p < 0.001) and, by trend, with serum iron (r = 0.69, p = 0.004). Nigral echogenicity was not clearly related to serum values associated with iron metabolism. Susceptibility and echogenicity measurements were unrelated to PD duration, motor subtype, and severity of motor and non-motor symptoms. The present results support the assumption that iron accumulation is involved in the increase of nigral echogenicity in PD. Nigral echo-intensity probably reflects ferritin-bound iron, e.g. stored in microglia.

In vitro test setups for simulated application testing are necessary for physician training as well as for development and benchmarking of various devices in interventional neuroradiology. Within the current study, we implemented a test setup for in vitro simulated application testing. Trackability in the distal catheter area, which was positioned inside a complex 3D vascular model was analyzed for two neurovascular stent systems (Neuroform EZ 4.0x20 mm and Enterprise VRD 4.5x14 mm) combined with different microcatheters (Excelsior XT-27 Flex, PX Slim Delivery Microcatheter and Prowler Select Plus Infusion Catheter). The described test setup allows for a diffentiation of neurovascular stent systems with regard to the trackability force as a major procedure related indicator for device handling. Therefore, the simulated application system presented within the current work represents an indispensable tool for safely and efficiently developing and evaluating new technologies for interventional neuroradiology prior to clinical implementation.

OBJECTIVE:The current study aims to investigate whether objective measurements of the cochlear nerve (CN), derived from preoperative MRI images, correlate with postoperative speech perception in CI patients. STUDY DESIGN:Retrospective cohort study. SETTING:University Medical Center, tertiary academic referral center. PATIENTS:Patients undergoing a cochlear implant surgery including MED-EL (Synchrony 2, FLEX electrode series; MED-EL, Innsbruck, Austria) Cochlear (slim straight electrodes; Cochlear Ltd., Sydney, Australia), Advanced Bionics (HiRes Ultra 3D CI, HiFocus SlimJ electrodes; Sonova, Zürich, Switzerland), and Oticon (Neuro Zti EVO; Oticon A/S, Smørum, Denmark) between 2020 and 2023. INTERVENTION:Preoperative MRI images were utilized to measure the volume of the modiolus (VM), the cross-sectional areas of the CN (ACN), and for normalization, the area of the facial nerve (AFN) and the area of the internal ear canal (AIEC). Postoperative speech perceptions were assessed through word recognition scores (WRS) at several stages following the first fitting (FF) of the CI processor: immediately after FF, 1 month, 3 months, and 6 months after FF. MAIN OUTCOME MEASURES:Sixty-eight patients were enrolled in this study. A statistically significant positive correlation between the ratio between ACN and AFN (ACN/AFN) and WRS FF was identified ( R  = 0.36, p  < 0.003). However, this correlation disappeared in subsequent follow-up tests. Moreover, upon grouping patients based on their degree of asymmetrical hearing loss, it was observed that the correlation was primarily driven by patients with moderate to severe asymmetrical hearing loss (AHLm) on the contralateral side ( R  = 0.62, p  = 0.0003). CONCLUSION:The present results suggest that assessing the size of the CN through MRI has limited predictive utility for postoperative speech perceptions during CI consultations. This limitation seems to be particularly relevant for AHLm patients and is confined to the initial activation period.

Patients with chronic daily headaches (CDH) are often a diagnostic challenge and frequently undergo neuroimaging. One common underlying cause of CDH is idiopathic intracranial hypertension (IIH). However, certain neuroimaging abnormalities that suggest IIH, such as optic nerve sheath diameters (ONSD), pituitary gland height, and venous sinus diameter, require interpretation due to the absence of established normative values. Notably, intracranial pressure is known to varies with age, sex and weight, further complicating the determination of objectively abnormal findings within a specific patient group. This study aims to assist clinical neuroradiologists in differentiating neuroimaging results in CDH by providing weight-adjusted normative values for imaging characteristics of IIH. In addition to age and BMI we here assessed 1924 population-based T1-weighted MRI datasets of healthy participants for relevant MRI aspects of IIH. Association to BMI was analyzed using linear/logistic regression controlled for age and stratified for sex. ONSD was 4.3 mm [2.8; 5.9]/4.6 mm [3.6; 5.7] and diameter of transverse sinus was 4.67 mm [1.6; 6.5]/4.45 mm [3.0; 7.9]. Height of pituitary gland was 5.1 mm [2.2;8.1]/4.6 mm [1.9;7.1] for female and male respectively. Values generally varied with BMI with regression slopes spanning 0.0001 to 0.05 and were therefor presented as normative values stratified by BMI. Protrusion of ocular papilla, empty sella and transverse sinus occlusion were rare in total. Our data show an association between BMI and commonly used MRI features for diagnosing IIH. We provide categorized normative BMI values for ONSD, pituitary gland height, and transverse sinus diameter. This distinction helps objectively identify potential IIH indicators compared to regular population norms, enhancing diagnostic accuracy for suspected IIH patients. Notably, optic nerve head protrusion, empty sella, and transverse sinus occlusion are rare in healthy individuals, solidifying their importance as imaging markers regardless of BMI.

Neuroimaging-based machine learning models are widely employed to analyze healthy brain aging and its pathological deviations. This includes regression models that estimate a brain's biological age using structural MR images, generative models that capture the conditional distribution of aging-related brain morphology changes, and hybrid generative-inferential models that handle both tasks. Generative models are useful when systematically analyzing the influence that different semantic factors have on brain morphology. Within this context, this paper builds upon a recently proposed normalizing flow-based, generative-inferential brain aging model (iBAM) that uses supervision to disentangle age and age-unrelated identity information of a subject's brain morphology in its structured latent space. We analyze the effects adding sex as an additional supervised factor to iBAM has on the latent space when using real data. Moreover, we propose to learn an identity part that is ordered with respect to the amount of morphological variability covered. Our results on T1 images from more than 5000 healthy subjects show that iBAM is able to successfully disentangle age and sex from the identity information using supervision. Furthermore, the identity part is ordered, which aids efficient exploration and summarization of inter-subject variations.

Abstract Introduction Immunological alterations associated with increased susceptibility to infection are an essential aspect of stroke pathophysiology. Several immunological functions of adipose tissue are altered by obesity and are accompanied by chronic immune activation. The purpose of this study was to examine immune function (monocytes, granulocytes, cytokines) as a function of body mass index (BMI: 1st group: 25; 2nd group: 25 BMI 30; 3rd group: 30) and changes in body weight post stroke. Method Fat status was assessed using standardized weight measurements on days 1, 2, 3, 4, 5, and 7 after ischemic stroke in a cohort of 40 stroke patients and 16 control patients. Liver fat and visceral fat were assessed by MRI on day 1 or 2 [I] and on day 5 or 7 [II]. Leukocyte subpopulations in peripheral blood, cytokines, chemokines, and adipokine concentrations in sera were quantified. In a second cohort (stroke and control group, n = 17), multiple regression analysis was used to identify correlations between BMI and monocyte and granulocyte subpopulations. Results Weight and fat loss occurred from the day of admission to day 1 after stroke without further reduction in the postischemic course. No significant changes in liver or visceral fat were observed between MRI I and MRI II. BMI was inversely associated with IL-6 levels, while proinflammatory cytokines such as eotaxin, IFN-β, IFN -γ and TNF-α were upregulated when BMI increased. The numbers of anti-inflammatory CD14+CD16+ monocytes and CD16+CD62L− granulocytes were reduced in patients with higher BMI values, while that of proinflammatory CD16dimCD62L+ granulocytes was increased. Conclusion A small weight loss in stroke patients was detectable. The data demonstrate a positive correlation between BMI and a proinflammatory poststroke immune response. This provides a potential link to how obesity may affect the clinical outcome of stroke patients.