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BackgroundMiddle meningeal artery (MMA) embolization is a promising intervention as a stand-alone or adjunct treatment to surgery in patients with chronic subdural hematomas. There are currently no large animal models for selective access and embolization of the MMA for preclinical evaluation of this endovascular modality. Our objective was to introduce a novel in vivo model of selective MMA embolization in swine.MethodsDiagnostic cerebral angiography with selective microcatheter catheterization into the MMA was performed under general anesthesia in five swine. Anatomical variants in arterial meningeal supply were examined. In two animals, subsequent embolization of the MMA with a liquid embolic agent (Onyx-18) was performed, followed by brain tissue harvest and histological analysis.ResultsThe MMA was consistently localized as a branch of the internal maxillary artery just distal to the origin of the ascending pharyngeal artery. Additional meningeal supply was observed from the external ophthalmic artery, although not present consistently. MMA embolization with Onyx was technically successful and feasible. Histological analysis showed Onyx material within the MMA lumen.ConclusionsMicrocatheter access into the MMA in swine with liquid embolic agent delivery represents a reproducible model of MMA embolization. Anatomical variations in the distribution of arterial supply to the meninges exist. This model has a potential application for comparing therapeutic effects of various embolic agents in a preclinical setting that closely resembles the MMA embolization procedure in humans.

Chimeric antigen receptor (CAR) T-cell therapy has transformed the treatment landscape of lymphoma and is now approved by the FDA for multiple indications. Given that the indications for CAR T-cell therapy are expanding, a larger patient population will be eligible to receive this treatment in the coming years. Pivotal clinical trials leading to FDA approval of CAR T-cell products required patients to have adequate organ function and good performance status. In the real world, however, the patient population eligible for CAR T-cell therapy includes patients who are older, frail, have poor performance status, and have multiple comorbidities. Studies have shown that CAR T-cell therapy is relatively safe and tolerable in such frail patients, however, there is no agreed upon consensus or guidelines to assess eligibility for CAR T-cell therapy at this moment. Gaining further insight into such patient populations will be vital in order to safely provide and expand access to CAR T-cell therapy.

Industry 4.0 symbolizes various applications and technologies that have many possible positive effects within the industrial field. The complex production area contains longer product cycle times and multiple levels of subassemblies, and this reflects a higher need for raising production efficiency and optimizing the resources and time. Adopting developed Industry 4.0 technologies is considered a promising way for achieving this since they contribute directly to real-time data analysis, remote operation, and complete product life analysis next to further tools that allow more profound and inclusive analysis in the target complex production system. This article discusses the integration of Industry 4.0 technologies with in-plant complex production processes. A proposed system with an optimization purpose is designed and described that focuses on using multi-level integration processes effectively.

This paper presents the first-ever evaluation of the thermochemical properties and suitability of mango wood (MW) for energy production. The data is compared to that of sugarcane bagasse (SB), a common biomass in waste-to-energy technology (WTE). Proximate, ultimate, and calorific analyses were conducted to assess the energy potential of MW, while thermogravimetric analysis was employed to investigate its decomposition behavior under pyrolysis conditions. Exhibiting low nitrogen content and an absence of sulfur, the two samples emerged as environmentally friendly energy sources. To investigate their potential for biocrude oil production, hydrothermal liquefaction (HTL) was conducted at low temperature (180 °C) in the presence of water/methanol (35/15v/v) co-solvent system. The results revealed a remarkable enhancement in biocrude oil production, attributed to the strong interaction between the co-solvents and biomass intermediates. Mango wood waste exhibited higher conversion rate of 70 wt%, resulting in higher biocrude oil yield and lower hydrochar selectivity. The biocrude oil produced from MW had a higher heating value (HHV) of 29.70 MJ/kg and higher energy recovery (EY% ~ 50.60%) than that from SB. Moreover, it contains high concentration of phenolic compounds, contributing to enhance its stability; however, SB biocrude oil exhibited an aromatic hydrocarbon content (> 25%), making it suitable candidate for blending with diesel fuel. The hydrochar produced from MW exhibited high HHV of ~ 23.61 MJ/kg and lower EY% of ~ 45.02%, outperforming SB hydrochar in both aspects (HHV ~ 22.7 MJ/kg, EY% ~ 65.43%). Additionally, the MW hydrochar has high ignition temperature and lower burnout temperature.

Enlargement or aneurysm of the aorta predisposes to dissection, an important cause of sudden death. We trained a deep learning model to evaluate the dimensions of the ascending and descending thoracic aorta in 4.6 million cardiac magnetic resonance images from the UK Biobank. We then conducted genome-wide association studies in 39,688 individuals, identifying 82 loci associated with ascending and 47 with descending thoracic aortic diameter, of which 14 loci overlapped. Transcriptome-wide analyses, rare-variant burden tests and human aortic single nucleus RNA sequencing prioritized genes including SVIL, which was strongly associated with descending aortic diameter. A polygenic score for ascending aortic diameter was associated with thoracic aortic aneurysm in 385,621 UK Biobank participants (hazard ratio = 1.43 per s.d., confidence interval 1.32–1.54, P= 3.3 × 10−20). Our results illustrate the potential for rapidly defining quantitative traits with deep learning, an approach that can be broadly applied to biomedical images.

Recent human decedent model studies1,2and compassionate xenograft use3have explored the promise of porcine organs for human transplantation. To proceed to human studies, a clinically ready porcine donor must be engineered and its xenograft successfully tested in nonhuman primates. Here we describe the design, creation and long-term life-supporting function of kidney grafts from a genetically engineered porcine donor transplanted into a cynomolgus monkey model. The porcine donor was engineered to carry 69 genomic edits, eliminating glycan antigens, overexpressing human transgenes and inactivating porcine endogenous retroviruses. In vitro functional analyses showed that the edited kidney endothelial cells modulated inflammation to an extent that was indistinguishable from that of human endothelial cells, suggesting that these edited cells acquired a high level of human immune compatibility. When transplanted into cynomolgus monkeys, the kidneys with three glycan antigen knockouts alone experienced poor graft survival, whereas those with glycan antigen knockouts and human transgene expression demonstrated significantly longer survival time, suggesting the benefit of human transgene expression in vivo. These results show that preclinical studies of renal xenotransplantation could be successfully conducted in nonhuman primates and bring us closer to clinical trials of genetically engineered porcine renal grafts.

We sought to characterize cellular composition across the cardiovascular system of the healthy Wistar rat, an important model in preclinical cardiovascular research. We performed single-nucleus RNA sequencing (snRNA-seq) in 78 samples in 10 distinct regions, including the four chambers of the heart, ventricular septum, sinoatrial node, atrioventricular node, aorta, pulmonary artery, and pulmonary veins, which produced 505,835 nuclei. We identified 26 distinct cell types and additional subtypes, with different cellular composition across cardiac regions and tissue-specific transcription for each cell type. Several cell subtypes were region specific, including a subtype of vascular smooth muscle cells enriched in the large vasculature. We observed tissue-enriched cellular communication networks, including heightened Nppa-Npr1/2/3 signaling in the sinoatrial node. The existence of tissue-restricted cell types suggests regional regulation of cardiovascular physiology. Our detailed transcriptional characterization of each cell type offers the potential to identify novel therapeutic targets and improve preclinical models of cardiovascular disease.

This systematic review explores the impact of international professional mobility (IPM) programmes for continuing professional development by addressing two key research questions: (1) What is the impact of IPM on participants? (2) What contributions do participants make at organisational, community, and national levels after participating in IPM? Drawing on 78 peer-reviewed studies and employing a Mixed-Methods Research Synthesis approach, this review provides a comprehensive analysis of how IPM fosters professional expertise, intercultural competencies, and career advancement, while also generating broader societal impacts. Despite reintegration challenges – such as resistance to new ideas and weakened domestic networks – participants contribute significantly to organisational innovation, community engagement, and cross-border collaboration. The review identifies three pressing areas for future research: the need for detailed analysis of specific programme characteristics, the complexities of post-mobility reintegration, and the fragmented use of theoretical frameworks in the existing literature. By synthesising the evidence, this review offers critical insights for policymakers, funding agencies, programme designers, and participants aiming to maximise the professional and societal value of IPM initiatives.

Through the design process of automotive composite structures, the designer needs to meet the mechanical characteristics and consider the sensitivity of the design to the environmental factors, which control its safety and feasibility. The current experimental study presents the effect of thermal aging on the crashworthiness of carbon/epoxy composite tubes under lateral crushing. Tubes were subjected to thermal aging at 70 and 100 °C for 14 days. Both empty and foam-filled tubes were studied. In addition, foam specimens were compressed under the same conditions to understand the behavior of the foam-filled tubes. The outcomes demonstrated that the addition of the foam improved the load carrying capacity and energy absorption. The matrix's thermal degradation and debonding were the primary factors in the reduction of crashworthiness. For the foam-filled composites, the reduction in the crashworthiness is lower because of having the foam inside the tube. The average crushing force increases by 14% and 29% for the specimens exposed to 70 and 100 °C for 14 days, respectively, which result in higher energy absorption. The improvement in the foam-filled structures by aging is governed by the higher strength and energy absorbed of the foam after thermal exposure, which supports the use of polyurethane foam as a filler in energy absorption devices.

The liver is bathed in bacterial products, including lipopolysaccharide transported from the intestinal portal vasculature, but maintains a state of tolerance that is exploited by persistent pathogens and tumours1–4. The cellular basis mediating this tolerance, yet allowing a switch to immunity or immunopathology, needs to be better understood for successful immunotherapy of liver diseases. Here we show that a variable proportion of CD8+T cells compartmentalized in the human liver co-stain for CD14 and other prototypic myeloid membrane proteins and are enriched in close proximity to CD14highmyeloid cells in hepatic zone 2. CD14+CD8+T cells preferentially accumulate within the donor pool in liver allografts, among hepatic virus-specific and tumour-infiltrating responses, and in cirrhotic ascites. CD14+CD8+T cells exhibit increased turnover, activation and constitutive immunomodulatory features with high homeostatic IL-10 and IL-2 production ex vivo, and enhanced antiviral/anti-tumour effector function after TCR engagement. This CD14+CD8+T cell profile can be recapitulated by the acquisition of membrane proteins—including the lipopolysaccharide receptor complex—from mononuclear phagocytes, resulting in augmented tumour killing by TCR-redirected T cells in vitro. CD14+CD8+T cells express integrins and chemokine receptors that favour interactions with the local stroma, which can promote their induction through CXCL12. Lipopolysaccharide can also increase the frequency of CD14+CD8+T cells in vitro and in vivo, and skew their function towards the production of chemotactic and regenerative cytokines. Thus, bacterial products in the gut–liver axis and tissue stromal factors can tune liver immunity by driving myeloid instruction of CD8+T cells with immunomodulatory ability.

The potential of machine learning mechanisms played a key role in improving the intrusion detection task. However, other factors such as quality of data, overfitting, imbalanced problems, etc. may greatly affect the performance of an intelligent intrusion detection system (IDS). To tackle these issues, this paper proposes a novel machine learning-based IDS called i-2NIDS. The novelty of this approach lies in the application of the nested cross-validation method, which necessitates using two loops: the outer loop is for hyper-parameter selection that costs least error during the run of a small amount of training set and the inner loop for the error estimation in the test set. The experiments showed significant improvements within NSL-KDD dataset with a test accuracy rate of 99.97%, 99.79%, 99.72%, 99.96%, and 99.98% in detecting normal activities, DDoS/DoS, Probing, R2L and U2R attacks, respectively. The obtained results approve the efficiency and superiority of the approach over other recent existing experiments.

Droplet-based single-cell assays, including single-cell RNA sequencing (scRNA-seq), single-nucleus RNA sequencing (snRNA-seq) and cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq), generate considerable background noise counts, the hallmark of which is nonzero counts in cell-free droplets and off-target gene expression in unexpected cell types. Such systematic background noise can lead to batch effects and spurious differential gene expression results. Here we develop a deep generative model based on the phenomenology of noise generation in droplet-based assays. The proposed model accurately distinguishes cell-containing droplets from cell-free droplets, learns the background noise profile and provides noise-free quantification in an end-to-end fashion. We implement this approach in the scalable and robust open-source software package CellBender. Analysis of simulated data demonstrates that CellBender operates near the theoretically optimal denoising limit. Extensive evaluations using real datasets and experimental benchmarks highlight enhanced concordance between droplet-based single-cell data and established gene expression patterns, while the learned background noise profile provides evidence of degraded or uncaptured cell types.

Heart failure encompasses a heterogeneous set of clinical features that converge on impaired cardiac contractile function1,2and presents a growing public health concern. Previous work has highlighted changes in both transcription and protein expression in failing hearts3,4, but may overlook molecular changes in less prevalent cell types. Here we identify extensive molecular alterations in failing hearts at single-cell resolution by performing single-nucleus RNA sequencing of nearly 600,000 nuclei in left ventricle samples from 11 hearts with dilated cardiomyopathy and 15 hearts with hypertrophic cardiomyopathy as well as 16 non-failing hearts. The transcriptional profiles of dilated or hypertrophic cardiomyopathy hearts broadly converged at the tissue and cell-type level. Further, a subset of hearts from patients with cardiomyopathy harbour a unique population of activated fibroblasts that is almost entirely absent from non-failing samples. We performed a CRISPR-knockout screen in primary human cardiac fibroblasts to evaluate this fibrotic cell state transition; knockout of genes associated with fibroblast transition resulted in a reduction of myofibroblast cell-state transition upon TGFβ1 stimulation for a subset of genes. Our results provide insights into the transcriptional diversity of the human heart in health and disease as well as new potential therapeutic targets and biomarkers for heart failure.

Abstract:"Three times the fire had come for him, but three times he lived. first in Daughter Paradise, when he was a child, still unaccustomed to the relentless want of burning. What he remembers of that day now is the sight of the abandoned vineyards past the edge of town, high orange curls sprouting out the tops of sheds and the old tasting room. […]"

Site-selective chemical methods for protein bioconjugation have revolutionized the fields of cell and chemical biology through the development of novel protein/enzyme probes bearing fluorescent, spectroscopic, or even toxic cargos. Herein, we report two new methods for the bioconjugation of α-oxo aldehyde handles within proteins using small molecule aniline and/or phenol probes. The “α-oxo-Mannich” and “catalyst-free aldol” ligations both compete for the electrophilic α-oxo aldehyde, which displays pH divergent reactivity proceeding through the “Mannich” pathway at acidic pH to afford bifunctionalized bioconjugates, and the “catalyst-free aldol” pathway at neutral pH to afford monofunctionalized bioconjugates. We explore the substrate scope and utility of both of these bioconjugations in the construction of neoglycoproteins, in the process formulating a mechanistic rationale for how both pathways intersect with each other at different reaction pH’s.

Les programmes de Récupération Accélérée Après Chirurgie (RAAC) ont été initialement développés en chirurgie colorectale d’après les travaux du Dr Khelet. La RAAC est la protocolisation complète du chemin clinique du patient, basée sur des preuves scientifiques. Son but est, en réduisant la réponse au stress chirurgical, d’améliorer la récupération des patients. Des recommandations ont été émises spécifiquement pour la chirurgie thoracique. Le but de ce papier est de présenter quels sont les éléments pour mener un programme de RAAC et discuter des éléments du chemin clinique.

2-Acylimidazoles are widely used as post-transformable carboxylic acid equivalents in chemoselective and enantioselective reactions. Their transformations, however, require pretreatment with highly reactive, toxic methylating reagents to facilitate C–C bond cleavage. Here, we demonstrate that such pretreatment can be avoided and the C–C bond cleaved under neutral conditions without the use of additional reagents or catalysts. The scope of the reaction, including the use of products reported in the literature as substrates, and some mechanistic insights are described.

Supplemental Digital Content is available in the text.

Die Einführung von Immuncheckpointinhibitoren (ICI) veränderte die Behandlung und die Prognose zahlreicher Tumorerkrankungen entscheidend. Grundsätzlich ist eine ICI-Therapie besser verträglich als eine klassische Chemotherapie, weist aufgrund ihres Wirkmechanismus aber auch ein neuartiges Nebenwirkungsspektrum auf. Durch die Blockade der Immuncheckpoints kann es zu verstärkten oder überschießenden Immunreaktionen kommen. Diese immunologisch vermittelten unerwünschten Effekte („immune-related adverse events“ [irAE]) können nahezu alle Organsysteme involvieren, wenngleich die Haut, der Darmtrakt, das endokrine System sowie Lunge und Leber am häufigsten betroffen sind. Eine rechtzeitige Diagnose von irAE ist essenziell. Sie werden üblicherweise nach den CTCAE-Kriterien (CTCAE: „common terminology criteria for adverse events“) klassifiziert. Im Rahmen einer PD-1-/PD-L1-Monotherapie (PD-1: „programmed death protein 1“, PD-L1: „programmed cell death 1 ligand 1“) sind die immunassoziierten Nebenwirkungen meist mild bis moderat; Toxizitäten Grad 3/4 treten nur mit einer Häufigkeit von ca. 14 % auf. Die duale Checkpointblockade (CTLA-4 [zytotoxisches T‑Lymphozyten-assoziiertes Protein 4] + PD-1/PD-L1) ist deutlich toxischer und zeigt Grad 3/4 Nebenwirkungen in der Größenordnung von 30–50 %. Vereinzelt sind auch schwere und selten sogar lebensbedrohliche Toxizitäten berichtet. Ab dem Auftreten einer Grad-3-Toxizität ist ein sofortiger Stopp der ICI-Therapie obligat. Initial besteht das Management der irAE aus einer topischen oder systemischen Steroidgabe, eine Therapieeskalation mit weiteren Immunsuppressiva erfolgt in Abhängigkeit von der Schwere und dem Organbefall sowie dem Ansprechen auf die Glukokortikoide. The introduction of immune checkpoint inhibitors (ICI) has rapidly changed the treatment and prognosis of numerous tumor entities. In general, therapy with ICI is better tolerated than conventional chemotherapy, but also displays a novel spectrum of side effects due to its mechanism of action. The blocking of immune checkpoints can result in increased or even excessive immune responses. These immune-related adverse events (irAE) can involve almost all organ systems, although skin, intestinal tract, endocrine system, lungs and liver are most commonly affected. Timely diagnosis of irAE is crucial and usually classified according to Common Terminology Criteria for Adverse Events criteria. In the context of PD-1/PD-L1 (PD-1: programmed death protein 1, PD-L1: programmed cell death 1 ligand 1) monotherapy, immune-associated adverse events are usually mild to moderate; grade 3/4 toxicities occur only with a frequency of about 14%. Dual checkpoint blockade (CTLA-4 [cytotoxic T‑lymphocyte-associated protein 4]+ PD-1/PD-L1) is significantly more toxic and shows grade 3/4 adverse events in the range of 30–50%. However, severe or even life-threatening toxicities are rare. At the onset of grade ≥3 toxicity, an immediate stop of ICI therapy is mandatory. Initially, the management of the irAE consists of topical or systemic steroid administration, an escalation of therapy with additional immunosuppressants depends on severity and organ involvement as well as on response to steroids.

Egypt's scientific community is hoping for a renaissance based on engineering and technology, ushered in by the election as president of an engineer with an academic background in material science.

Supplemental Digital Content is available in the text.

In the present study, we aim to propose an effective and robust ensemble-learning approach with stacked generalization for image segmentation. Initially, the input images are processed for feature extraction and edge detection using the Gabor filter and the Canny algorithms, respectively; our main goal is to determine the most feature descriptions. Subsequently, we applied the stacking generalization technique, which is generally built with two main learning levels. The first level is composed of two algorithms that give good results in the literature, namely: LightGBM (Light Gradient Boosting Machine) and SVM (support vector machine). The second level is the meta-model in which we use a predictor model that takes the base-level predictions to improve the accuracy of the final prediction. In the stacked generalization process, we use the Extreme Gradient Boosting (XGBoost); it takes as input the sub-models’ outputs to better classify each pixel of the image to give the final prediction. Today, several research works exist in the literature using different machine learning algorithms; in fact, instead of trying to find a single efficient and optimal learner, ensemble-based techniques take the advantage of each basic model; they integrate their outputs to obtain a more consistent and reliable learner. The result obtained from the models of individuals and our proposed approach is compared using a set of evaluation measures for image quality such as IoU, DSC, CC, SSIM, SAM, and UQI. The evaluation and a comparison of the results obtained showed more consistent predictions for the proposed model. Thus, we have made a comparison with some recent deep learning-based unsupervised segmentation methods. The evaluation and a comparison of the results obtained showed more coherent predictions for our stacked generalization in terms of precision, robustness, and consistency.

Introduction: Low-risk MDS is characterized by refractory anemia due to Dyserythropoiesis 1. Standard of care treatment is mainly Erythropoiesis stimulating agents (ESA) or blood transfusion or both 1. Response to ESA is achieved in some patients whose erythropoietin (EPO) level is less than 500 mu/ml 2. Luspatercept is a red cell maturing agent that may lead to an increase in Hb of up to 3 g/dL 3in responders. Response to ESA can be enhanced with the addition of Luspatercept 4.

Colonoscopy-guided mucosal injection is used to induce site-directed tumors and to transplant tumors into the distal colons of mice. Tumors for engraftment are obtained from cancer organoids derived from mouse or human tissue and can be genetically modified before use.

The tumor microenvironment (TME) in pancreatic ductal adenocarcinoma (PDA) is characterized by immune tolerance, which enables disease to progress unabated by adaptive immunity. However, the drivers of this tolerogenic program are incompletely defined. In this study, we found that NLRP3 promotes expansion of immune-suppressive macrophages in PDA. NLRP3 signaling in macrophages drives the differentiation of CD4+ T cells into tumor-promoting T helper type 2 cell (Th2 cell), Th17 cell, and regulatory T cell populations while suppressing Th1 cell polarization and cytotoxic CD8+ T cell activation. The suppressive effects of NLRP3 signaling were IL-10 dependent. Pharmacological inhibition or deletion of NLRP3, ASC (apoptosis-associated speck-like protein containing a CARD complex), or caspase-1 protected against PDA and was associated with immunogenic reprogramming of innate and adaptive immunity within the TME. Similarly, transfer of PDA-entrained macrophages or T cells from NLRP3−/− hosts was protective. These data suggest that targeting NLRP3 holds the promise for the immunotherapy of PDA.

Activation of dectin-1-dependent signaling in macrophages through ligation by galectin 9 promotes an immunosuppressive, protumorigenic microenvironment in pancreatic adenocarcinoma (PDA). Blocking dectin 1 ligation restores anti-tumor immunity and delays tumor growth, thus offering a novel strategy for improving the effectiveness of immunotherapy in patients with PDA.

Today, image segmentation plays a vital role in many crucial areas. This paper will cover the important role that image segmentation plays in medical imaging issues. Image segmentation is the process of dividing a random image into groups or partitions; the main goal here is to separate the objects from the background, to make it easier to analyze each of them individually, like in our case when the purpose is to detect and segment the tumor. In the upcoming sections, we’ll be presenting a new medical imaging technique for detecting brain tumors in MRI images. For this, we will use two algorithms. The first one is Birch which is a fast hierarchical method of grouping and reducing data. The second algorithm is the segmentation by the Watershed, these two algorithms will be explained further in detail. The first step is to segment the input MRI image using the Birch method, then the resulting image will be launched into the second algorithm which is the Watershed. The proposed method has been applied and tested on 155 images from the Kaggle dataset to detect abnormalities such as tumors. According to the results, we can say that it gives a satisfactory and efficient detection result. To evaluate the performance of our proposed method, we used a very known set of parameters such as the dice coefficient that reached 96%, the sensitivity achieved 99%, in specificity we obtained 98, and a Jaccard similarity of 94%. All the given evaluating metrics achieved satisfactory results and good segmentation of the brain tumor. Furthermore, our proposed approach was compared to the SOTA methods, and the obtained results outperformed the state-of-the-art brain tumor extraction by 5%.

Study Design Interventional human cadaver study.Objective Intraoperative three-dimensional (3-D)-guided navigation improves spine instrumentation accuracy. However, image acquisition may need to be repeated with segment hypermobility or distant target from reference frame (RF). The current study evaluates the usefulness of internal metal fiducials (IMFs) as surface references in enhancing registration accuracy and avoiding repeating imaging.Methods Six fresh-frozen cadaveric human torsos were utilized. Posterior C1–T2 exposure was done, and three IMFs were inserted per level; intraoperative 3-D images were then acquired. Two registration methods were utilized: autoregistration (AR, group 1) and point registration using IMF (IMFR, group 2). Registration accuracy was checked by identifying IMFs in both groups. Pedicle screws inserted into C2, C4, C5, and C7 based on the two registration methods (three cadavers each) with RF on C7 and then on C2.Results The mean registration error was lower with IMFR compared with AR (0.35?±?0.5?mm versus 2.02?±?0.85?mm, p?=?0.0001). Overall, 34 pedicle screws were inserted (AR, 18; IMFR, 16). Final screw placement was comparable using both techniques (p?=?0.58). Lateral screws violations were observed in four IMFR screws (1 to 2 mm) as compared with five in AR group (2 to 3 mm). Reregistration after moving RF to C2 was possible using surface screws in IMFR group, thus avoiding new 3-D image acquisition.Conclusion During intraoperative 3-D navigation in spine procedures, surface fiducial registration using IMF provided superior accuracy over automated registration. It allowed repeat registration without repeating radiation during long spine segment instrumentations. More studies are needed to clarify both practical and clinical application of this method.