Society 5.0 envisions a future where technology and humanity integrate to address societal concerns. In an era marked by significant technological advancements, particularly in artificial intelligence, it is vital to uphold the core values of compassionate care and human connection. While the healthcare sector is central to this transformation, the prevailing research ethics frameworks remain dominated by Western individualism and positivism. This conceptual paper aims to establish a case for integrating African research canons-ujamaa, utulivu, kujitoa, uhaki, and ukweli-into bioethical discourse to create a more inclusive, culturally relevant framework. As a conceptual review, this paper analyses existing Afrocentric paradigms and uses the Bachelor of Clinical Medical Practice (BCMP) curriculum as an illustrative case study of decolonised ethics in practice. Incorporating Ubuntu and specific African research canons challenges the Western-centric status quo, fostering a research environment that prioritises communal well-being and harmony. We can contribute to humanising healthcare by integrating these Afrocentric values, working towards creating a society that is more inclusive and compassionate. The inclusion of African research canons may lead to inclusive and culturally relevant research ethics by shifting the emphasis from Western individualism to a more holistic and human-centred approach.
To evaluate an in-house newly fabricated patient-specific pediatric head CT phantom developed for trauma-oriented emergency imaging, with emphasis on multiplanar visual realism, cross-platform interpretability, and expert-reader assessment of diagnostic acceptability. A heterogeneous phantom was generated from an anonymized retrospective head CT dataset of a 5-year-old child and designed to preserve emergency-relevant osseous, aerated, orbital, and intracranial anatomy. A complex orbito-nasal midface trauma was incorporated as a trauma-mimicking feature. CT was performed on two clinical multidetector systems from different vendors: a 64-row GE Discovery CT750 HD and an 80-row Canon Aquilion RXL, each using routine pediatric head CT protocols. Ten radiologists independently reviewed axial, coronal, and sagittal reformations in bone and soft-tissue windows using a structured 20-item, 4-domain scoring framework. Representative multiplanar images showed preserved calvarial contour, skull-base and orbital anatomy, aerated sinonasal spaces, intracranial contour, falcine/midline anatomy, ventricular depiction, posterior fossa appearance, and visualization of the complex orbito-nasal midface trauma. Expert ratings were favorable on both scanners, with higher scores on Canon across all domains. Domain means on Canon versus GE were 4.38 versus 4.02 for osseous realism, 4.32 versus 4.00 for soft-tissue realism, 4.36 versus 4.18 for multiplanar interpretability, and 4.57 versus 4.10 for clinical utility. Overall composite scores were 4.38 on Canon and 4.07 on GE, paired domain-level differences showed higher mean scores for the Canon dataset in all domains, with the largest difference in clinical utility (+ 0.47). The phantom provided clinically recognizable, trauma-relevant pediatric emergency head CT appearances across multiplanar bone and soft-tissue review and was rated as realistic and diagnostically acceptable by expert readers, supporting its use in protocol evaluation, training, and observer-based emergency radiology research.
This commentary advances a reframing of science as a dialectical process that moves from local lifeworld to provisional universals and back to locally situated renewal. We term this movement Indigenized Science. Building on two decades of cultural praxis work, we propose that universalization has broadened inclusion yet often stalls before reembedding knowledge into the geographic, linguistic, and sociopolitical contexts where athletes live and practitioners work with coaches, teammates, staff, and administrative leadership. Herein, we (a) synthesize how cultural sport psychology has progressed from early calls for awareness to contextualized inquiry, (b) identify limits of prevailing Anglophone methodological canons when transported across geographic settings, and (c) propose a culturally relevant and safe actionable framework for indigenizing research and practice. We offer an actionable framework specifying six intervention points: literature (multilingual and cross-regional canons), philosophies of science (context-congruent epistemologies), development of cooperation (international cooperation), situating of authors/participants/contexts (explicit "place" and positionality), modes of inquiry (community-compatible designs and elicitation), and analytic strategies (coanalysis and coauthorship to preserve local meaning). We exemplify how these choices cohere to enhance ecological validity, ethical reciprocity, and knowledge translation across diverse systems. This contribution reveals a methodological and ethical orientation, but it is not a replacement for scientific generalization. Rather, it is a disciplined return to contexts renewing and reinforcing science. We conclude with implications for scientist-practitioner training, positioning indigenization as a rigor-enhancing route to globally relevant, locally resonant sport psychology.
Academic nursing does not simply have a diversity problem; it has a knowledge problem. The discipline's credentialing systems, editorial norms, accreditation frameworks, and theoretical canon function as gatekeeping mechanisms that shape whose scholarship is recognized as legitimate, whose methods are considered rigorous, and whose expertise is institutionally validated. Although critical theoretical frameworks have increasingly entered nursing discourse, their structural implications are frequently diluted or neutralized within institutional practice. The purpose of this paper is to examine academic nursing as an epistemological gatekeeper and to analyze how nursing's knowledge infrastructure sustains racial hierarchy while simultaneously performing commitment to equity. Drawing on Critical Race Theory (CRT), and specifically Cheryl Harris's concept of whiteness as property, this conceptual analysis examines the structural and epistemic mechanisms through which academic nursing regulates legitimacy, knowledge production, and disciplinary authority. The paper also considers common diversity, equity, and inclusion (DEI) counterarguments within nursing institutions. The analysis argues that epistemic gatekeeping within academic nursing is neither accidental nor benign. Critical frameworks such as CRT are often incorporated into nursing discourse only after being stripped of structural force and rendered institutionally safe. These dynamics influence who teaches nursing, what nurses are taught, and the profession's capacity to fulfill its stated commitments to health equity. The paper identifies mechanisms of epistemic exclusion and examines how institutional norms reproduce racialized hierarchies of knowledge and authority. Academic nursing must confront not only issues of representation, but also the epistemological structures that govern legitimacy and authority within the discipline. Structural reform is necessary to address entrenched forms of epistemic gatekeeping and to advance meaningful institutional accountability in nursing education and scholarship.
Metal artifacts in computed tomography (CT) significantly compromise image quality and CT number (CTN) accuracy, which may influence downstream applications such as radiation therapy workflows. Although commercial metal artifact reduction (MAR) algorithms are widely used, their performance varies across vendors and clinical scenarios, and standardized methods for quantitative comparison remain limited. This study quantitatively compares four commercial MAR algorithms using standardized metrics and a novel analytical approach. A custom-designed resin phantom with interchangeable inserts (solid water, aluminum, titanium, and stainless steel) was scanned using four CT systems: Canon, GE, Philips, and Siemens. Each system's proprietary MAR algorithm was applied to obtain artifact-reduced image sets. Quantitative analysis employed complementary methods: (1) circular profile analysis measuring mean CTN deviations at concentric distances from metal objects; (2) geometric accuracy assessment of metal objects; and (3) volumetric artifact characterization using analysis of severe artifact voxels and composite error metric (M-error index) that integrates both artifact extent and intensity. Color maps and accumulated histograms of ΔCTN values between pre- and post-MAR images were used to characterized artifact patterns and MAR performance. All four MAR methods showed minimal |ΔCTN| at mid (2.80 cm) and far (3.80 cm) distances but showed pronounced increases in |ΔCTN| near the metal interface at the closest radius (1.27 cm). Smart-MAR exhibited the highest CTN deviation for aluminum (16.83 HU), while O-MAR showed the largest deviations for titanium and stainless steel (42.40 and 42.60 HU). Quantitative evaluation showed that single-energy metal artifact reduction (SEMAR) and iterative metal artifact reduction (iMAR) achieved the most consistent geometric accuracy (<5%) across all metals. O-MAR showed the highest accuracy for titanium (approximately 0.36%) but larger deviations for aluminum (approximately 9%), while Smart-MAR exhibited the greatest errors exceeding 19% for both titanium and stainless steel. SEMAR, Smart-MAR, and iMAR showed lower M Error values (0.00-0.83) than O-MAR, which showed significantly higher values (1.15-2.45). SEMAR and iMAR achieved the most consistent geometric accuracy (<5% error) and artifact suppression across all metals, while O-MAR demonstrated material-dependent performance with substantial residual artifacts near metal interfaces. These phantom-based benchmarks provide vendor-neutral performance data on MAR performance under controlled settings.
A super-resolution deep learning (DL) image reconstruction algorithm (Precise Image Quality Engine (PIQE)) was originally designed for cardiac CT, but is now available for abdominal CT. To examine objective and subjective image quality (IQ) improvements PIQE compared to Advanced Intelligent Clear-IQ Engine (AiCE) in abdominal CT. A retrospective analysis was conducted on 69 adult patient routine contrast enhanced abdominopelvic CT exams on a single Aquilion ONE/INSIGHT CT system (Canon Medical Systems, Otawara Japan). Images were reconstructed using PIQE (strength level L1 and L2) and AiCE (L1- the institutional standard). Four blinded radiologists assessed image noise, image contrast, small structure visibility, image sharpness, artifacts, and overall image preference with Likert scales. Reader agreement was assessed with Krippendorff's alpha. Circular regions of interest were placed on five slices on the left and right liver, portal vein, aorta, subcutaneous fat, and bilateral psoas muscles. CT number, noise, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) were determined. All significant differences between reconstructions were assessed via the Friedman test with post-hoc Dunn-Sidak corrections. Reader agreement was fair ( α ¯ = 0.20 $\bar{\alpha}=0.20$ ). PIQE L2 was preferred for image contrast and image noise and PIQE L1 was preferred for image sharpness (p < 0.05). CT numbers were significantly different between AiCE L1 and PIQE (p < 0.05) and noise was statistically lowest in PIQE L2 compared to AiCE L1 (p < 0.05). SNR and CNR differences were statistically significant (p < 0.003), with PIQE L2 demonstrating the highest SNR and CNR. The best subjective IQ metrics for image contrast, image noise, and image sharpness were obtained with PIQE. The best objective IQ metrics (SNR and CNR) were obtained with PIQE L2. This work supports improved image contrast and decreased noise when using PIQE as compared to AiCE.
This data article presents an image dataset compiled for the purpose of machine learning-based identification and prediction of adulteration levels in Teff (Eragrostis tef (Zucc.) Trotter) flour. The dataset includes images of pure white, mixed, and red Teff flour varieties, as well as these flours adulterated with wood flour (sawdust) and gypsum (calcium sulfate) powder. Adulteration levels range from 10% to 40% in 5% increments. The data collection process involved preparing Teff flour from naturally dried and milled Teff grains. Samples of 100 grams of each Teff flour variety were then mixed with the adulterants at the specified concentrations. A total of 5000 raw images were captured using an 18-megapixel Canon EOS 7D camera under controlled studio lighting (300 W incandescent lamps), with the samples placed 30 cm from the camera lens in a 10 cm x 10 cm plastic box. To enhance the dataset's diversity and quantity, 25,000 augmented images were generated by shuffling image pixels' locations with various block sizes (1 × 1, 2 × 2, 4 × 4, 8 × 8, and 16 × 16). This dataset is a valuable resource for researchers and students in Teff adulteration using image processing and feature extraction. It also holds potential for use by Food and Drug Administration Authorities and law enforcement to develop automated methods for detecting Teff flour adulteration, offering an alternative to time-consuming physio-chemical laboratory tests. The dataset's structure and augmentation methods are detailed to ensure reproducibility and encourage further research into robust machine learning models for food quality control.
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Reviving extinct animals offers a crucial opportunity to recover lost or unknown genetic resources, yet cloning methods are unsuitable because they depend on intact donor nuclei and abundant oocytes or recipients from closely related species. To overcome these constraints, we explored a chromosome level revival strategy. Blood cells from rat carcasses stored at - 30 °C for over one year were introduced into enucleated mouse oocytes, where the rat nuclei underwent premature chromosome condensation. Microtubule polymerization inhibition enabled dispersion of rat chromosomes within the ooplasm, allowing isolation of individual chromosomes by micromanipulation. Each chromosome was subsequently transferred into an intact mouse oocyte, followed by intracytoplasmic sperm injection using GFP-transgenic mouse sperm. Embryos were cultured to the blastocyst stage, yielding 17 ES cell lines, two of which carried 41 chromosomes. Spectral karyotyping confirmed the presence of rat chromosome 9 alongside a full set of normal mouse chromosomes. These ES cells generated chimeric mice exhibiting GFP based chimerism across multiple organs. Histological analyses further demonstrated expression of numerous genes located on rat chromosome 9 within chimera mouse. This study demonstrated that a single chromosome from a frozen extinct species can be functionally revived and its transcriptional activity assessed within an interspecies oocyte.
Coronary artery disease (CAD) is common in patients treated for structural heart disease, but its prevalence, prognostic impact, and optimal management in patients undergoing tricuspid transcatheter edge-to-edge repair (T-TEER) remain uncertain. The aim of this study was to examine whether the presence of CAD, its anatomical complexity, and the extent of revascularization influence outcomes after T-TEER. In this observational study, 361 consecutive T-TEER patients underwent preprocedural coronary angiography with SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) scoring. CAD was defined as ≥70% stenosis (≥50% for the left main coronary artery). Residual SYNTAX score was calculated if revascularization was performed. The primary endpoint was 12-month all-cause mortality. Obstructive CAD was present in 124 patients (34.3%), with low lesion complexity (median SYNTAX score 6; Q1-Q3: 3-9.75). Among CAD patients, 33.9% underwent revascularization, reducing the residual SYNTAX score to 4 (Q1-Q3: 2-7). During the 12-month follow-up period, 16.7% of patients died. Survival over the follow-up period did not differ significantly according to the presence of obstructive CAD, baseline SYNTAX score, or residual SYNTAX score (12-month mortality for CAD vs no CAD 17.5% vs 16.3%; log-rank P = 0.616). Interaction analysis revealed effect modification by procedural risk determined by TRI-SCORE: in patients at low and intermediate risk, elevated residual SYNTAX score was associated with lower survival over follow-up (12-month mortality 20.8% vs 6.4%; log-rank P = 0.016), whereas no association was observed in high-risk patients (27.6% vs 27.1%; log-rank P = 0.927). Adding residual SYNTAX to the TRI-SCORE improved risk stratification in low- and intermediate-risk CAD patients (ΔC = +0.099). Obstructive CAD is common but typically low in complexity among T-TEER candidates. In low- and intermediate-risk patients, a higher residual SYNTAX score is associated with reduced survival.
The Breast Committee of the Arbeitsgemeinschaft Gynäkologische Onkologie (German Gynecological Oncology Group, AGO) presents the 2026 update of the evidence-based recommendations for the diagnosis and treatment of patients with locally advanced and metastatic breast cancer.
Sigmodontine rodents (Cricetidae: Sigmodontinae) represent the most diverse extant mammalian subfamily in both generic and species richness. Variation in conservative organ systems, such as the stomach, can provide insight into the morphological basis of their ecological diversification. Here, we examined the gross internal anatomy of 602 stomachs representing 168 species, 74 genera, and 13 tribes-approximately 80% of the subfamily's generic diversity-using sagittal and transverse sections. We propose a refined and standardized classification of stomach morphology based on the distribution of glandular and cornified epithelia. Five principal gastric designs are recognized: equiglandular, supraglandular, subglandular, discoglandular, and diverticular. The equiglandular condition predominates, occurring in approximately 65% of genera. Most tribes are characterized by a single gastric design, whereas Akodontini and Thomasomyini each exhibit multiple configurations. Notable exceptions include Phaenomys, which departs from the typical tribal pattern, and Thomasomys, the only genus exhibiting more than one stomach configuration. Ancestral-state reconstruction supports the equiglandular condition as the primitive state for Sigmodontinae and their sister clade, Tylomyinae. Independent origins of the diverticular condition in Akodontini and Thomasomyini indicate convergence, although detailed anatomical comparisons reveal distinct structural patterns. In addition, previously overlooked features-particularly the configuration of the bordering fold and its relationship to the esophageal opening and plica angularis-provide new insight into stomach organization. Overall, sigmodontine gastric morphology is structured across multiple hierarchical levels, combining strong phylogenetic signal with repeated evolutionary innovation. These results establish a comparative framework for interpreting stomach diversity and highlight the need for integrative approaches to fully understand digestive-system evolution in rodents.
C-reactive protein (CRP) predicts radiographic progression in radiographic axial spondyloarthritis (r-axSpA). Normal CRP levels have been associated with reduced response to tumor necrosis factor inhibitor treatment. Ixekizumab (IXE) has demonstrated effectiveness in smaller patient groups stratified by CRP at baseline. This pooled analysis aims to demonstrate efficacy stratified by CRP across a broader population. This post hoc analysis pooled biologic-naïve patients with r-axSpA from two phase III trials: COAST-V (N = 168) and NCT04285229 (N = 130), with participants receiving IXE 80 mg every 4 weeks or placebo for up to 52 weeks. Analyses evaluated outcomes in patients stratified by CRP at baseline (≤ 5 mg/L or > 5 mg/L). A second analysis subgrouped patients based on magnetic resonance imaging (MRI)-detected inflammation in the spine or sacroiliac joints (SIJ). Baseline characteristics were comparable between normal (N = 105 [35.2%]) and elevated CRP (N = 193 [64.8%]) groups, except for corticosteroid use, MRI-SPARCC spine and SIJ total scores, and ASDAS. Across groups, 67.8-81.8% of patients had MRI inflammation. By week 52, IXE demonstrated improvements in ASAS40 (61.2% [normal CRP], 63.0% [elevated CRP]), ASDAS LDA/ID (69.4% [normal CRP], 58.8% [elevated CRP]), and BASDAI50 (55.1% [normal CRP], 63.0% [elevated CRP]) compared with placebo. Similar improvements were observed across CRP groups for patients with MRI evidence of inflammation at weeks 16 and 52. Patients with r-axSpA and normal CRP at baseline have a similar disease burden to those with elevated CRP. IXE provides significant clinical benefits across key outcome measures regardless of CRP level. NCT02696785 and NCT04285229.
High systolic inter-arm blood pressure difference (SIABPD) is associated with cardiovascular events. We evaluated the prevalence of high SIABPD and its association with coronary and peripheral artery disease in people with HIV. The prevalence of high SIABPD was 24%, and SIABPD was independently associated with extensive coronary and peripheral arterial disease.
Robotic assistance may overcome the limitations of intraocular visualization during glaucoma surgery, particularly in eyes with corneal opacity. This preclinical study investigated the feasibility and surgical utility of a robotic-assisted intraocular endoscope-holding system for real-time visualization during Preserflo MicroShunt implantation. An endoscope-holding robot (OQrimo) enabled stable, hands-free intraocular imaging throughout the procedure. Porcine eyes were used, and corneal opacity was simulated with a black-painted contact lens. Surgical feasibility, tube-endothelium (TE) distance, and intraoperative complications were evaluated. Continuous endoscopic visualization using the robotic system enabled successful MicroShunt implantation in all eyes without complications, including intraoperative mechanical trauma to the cornea, iris, or lens. The TE distance was significantly greater in the robotic group than in the conventional group under both normal visualization conditions (1.96 ± 0.27 mm vs. 1.13 ± 0.40 mm, p = 0.009) and simulated corneal opacity (1.85 ± 0.32 mm vs. 1.12 ± 0.28 mm, p = 0.015), indicating more favorable tube positioning. These results demonstrate that robotic-assisted intraocular endoscopic visualization provides stable and precise guidance for MicroShunt implantation independent of corneal clarity. This technology has the potential to enhance surgical accuracy and expand the feasibility of minimally invasive glaucoma surgery in eyes with compromised anterior segment visualization.
The incidence of pulmonary nodules (PNs) has increased as the result of expanded lung cancer screening. PNs are often difficult to access with conventional bronchoscopy. We report data from the first cadaveric assessment of a novel multisection robotic bronchoscope (snake robot, or SR) with follow-the-leader navigation. This study was conducted in a human cadaver by 3 operators. The SR was compared against a conventional (OL-6.3) and thin bronchoscope (OL-4.2). Primary outcome was number of airway generations traversed from carina. Secondary outcomes included insertion depth, computed tomography-to-body divergence, and estimated volumes of lung parenchyma accessible for biopsy. Mann-Whitney U tests, paired t tests, and mixed regression models were used. Data are reported as n (%) or median (interquartile range). The SR reached greater median airway generations (6 [5-8]) when compared with the OL-6.3 (4 [3-4]; P < .001) and OL-4.2 (5 [4-6]; P < .001); it outperformed the OL-6.3 in all lobes and reached significantly greater airway generations compared with the OL-4.2 in the right upper lobe (P = .045), right middle lobe (P = .009), and right lower lobe (P = .025). Median insertion depth for the SR was greater compared with the OL-6.3 (P < .001) and OL-4.2 (P = .002). This additional reach resulted in greater access to total (P = .009) and peri-bronchial lung volumes (P = .009), which could translate into accessibility of an additional 17,601 nodules/year in the United States. The SR outperformed both the OL-6.3 and OL-4.2 with regard to reach within the tracheobronchial tree, resulting in significant additional lung parenchyma accessible for biopsy.
With the expanding clinical application of cardiac computed tomography (CT) for myocardial tissue characterization, the accuracy of extracellular volume fraction (ECV) quantification is critically dependent on image quality. This study aimed to compare the performance of deep learning reconstruction (DLR), hybrid iterative reconstruction (HIR), and model-based iterative reconstruction (MBIR) in terms of image quality and the accuracy of ECV quantification in cardiac CT. Fifty patients with suspected cardiac disease who underwent both cardiac CT and magnetic resonance imaging (MRI) were prospectively enrolled. Non-contrast and delayed-phase CT images were reconstructed using HIR, MBIR, and DLR algorithms, respectively. Visual image noise, beam-hardening artifacts, and display of myocardium and blood pool were evaluated using a four-point scale. CT value, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of six segments of myocardium were measured and calculated. CT-ECV of six segments of myocardium was calculated in subtraction images. Pearson or Spearman correlation and Bland-Altman analysis were used to evaluate the correlation and consistency between CT-ECV and MRI-ECV in six segments of myocardium. DLR significantly decreased image noise and beam-hardening artifacts, increasing SNR and CNR, providing superior visualization of the myocardium and blood pool compared to HIR and MBIR (P<0.001). In ECV quantification, DLR demonstrated a significantly lower mean absolute difference between CT-ECV and MRI-ECV across all six segments of myocardium (P<0.05). Compared with HIR and MBIR, DLR improved the correlation between CT-ECV and MRI-ECV (P<0.001). DLR showed the highest consistency in assessing ECV in all segments of myocardium (bias: -0.183) compared to HIR (bias: 0.390) and MBIR (bias: 0.540). Cardiac CT combined with DLR enhances the myocardial image quality and improves the accuracy of CT-ECV quantification.
Large language models (LLMs) can generate structured educational content at scale, yet their role in postgraduate radiology training remains untested. This pilot study evaluated the feasibility of deploying LLM-generated radiology board preparation materials, the psychometric properties of adapted survey instruments, and exploratory effect-size estimates for sample-size planning of a future multicentre trial. We conducted a prospective observational pilot among 41 radiology residents preparing for the 2026 Korean Radiology Board Examination. A governed seven-stage LLM pipeline generated 6,000 Anki flashcards, 833 infographic summaries, and presentation slides. Materials were distributed freely, and 24 completers self-selected into users (n = 15) and non-users (n = 9). Outcomes included enrollment yield, retention rate, voluntary adoption rate, internal consistency (Cronbach's alpha) of adapted cognitive load and satisfaction scales, and change scores in extraneous cognitive load (ECL) and self-efficacy (SE), compared using Mann-Whitney U tests with Cohen's d and 95% confidence intervals. Of 114 registered candidates, 44 were recruited (38.6%); 41 were enrolled (yield 93.2%); retention was 58.5% (24 of 41), below the prespecified 80% threshold; and voluntary adoption was 62.5%. The ECL scale showed acceptable reliability (alpha = 0.87 baseline, 0.80 post-examination). After reverse-coding one reverse-worded item (E3), the corrected three-item trust-in-AI alpha was 0.583 (bootstrap 95% CI 0.151 to 0.746), below the conventional 0.70 threshold. Between-group differences were non-significant for ECL (d = - 0.28; 95% CI - 1.50 to 0.59) and SE (d = 0.26; - 0.62 to 1.24). Among users, educational quality was rated 3.33 of 5.00, and 86.7% reported encountering no factual inaccuracies. A medium-effect scenario (d = 0.50) would require 160 participants. Retention (58.5%), the trust-scale alpha of 0.583, and the - 40 Net Promoter Score together indicate that the data-collection protocol, the AI-trust instrumentation, and the user-experience design all require modification before an efficacy trial is justified. Operational deployment was feasible at the levels of enrollment yield and voluntary adoption, but not retention. Adapted cognitive load and satisfaction scales reached acceptable reliability; the trust-in-AI and single-item self-efficacy outcomes did not meet conventional thresholds. Exploratory between-group point estimates were small and unstable across sensitivity strata; they are reported as inputs for sample-size planning and should not be interpreted as evidence for or against educational benefit.
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Postural changes influence systemic hemodynamics and may affect cerebral perfusion; however, quantitative evaluation remains limited in vivo under physiological gravitational conditions. We aimed to assess posture-dependent alterations in cerebral perfusion using upright multidetector computed tomography perfusion (CTP), with whole-brain cerebral blood flow (CBF) as the primary outcome. This was a single-center observational study of healthy volunteers approved by the institutional review board. Eighteen volunteers underwent CTP imaging in both the supine and seated positions on the same day using two 320-row multidetector CT scanners with identical systems. Whole-brain CBF was defined as the primary endpoint. Mean transit time (MTT) and cerebral blood volume (CBV) were evaluated as secondary outcomes. Paired comparisons were performed between postures, and exploratory analyses assessed regional changes and interindividual variability. Whole-brain CTP-derived CBF was significantly higher in the seated position than in the supine position (32.9 ± 6.0 [mean ± standard deviation] versus 29.2 ± 5.6 mL/100 g/min; p = 0.010), representing a 1.15 ± 0.19-fold increase. CTP-derived MTT was significantly shorter in the seated position (4.25 ± 0.61 versus 4.63 ± 0.72 s; p = 0.035), and CTP-derived CBV showed a modest but significant increase (2.23 ± 0.16 versus 2.16 ± 0.17 mL/100 g; p = 0.044). Regional perfusion changes were consistent across brain segments with interindividual variability in postural responses. Upright CTP detected posture-associated differences in whole-brain CTP-derived perfusion metrics, suggesting potential utility for investigating physiological and pathological alterations in cerebral hemodynamics associated with postural change. Upright CTP enables physiological evaluation of posture-related cerebral hemodynamics under gravitational loading and may provide new insights into cerebral circulation in both health and disease. Whole-brain cerebral blood flow increased by 15% in the seated position compared with supine using upright CT perfusion. Mean transit time shortened by 7% and cerebral blood volume increased modestly by 4% in the seated position. Perfusion responses showed marked interindividual variability, suggesting different physiological adaptations to posture.