Genetic and genomic evaluation of age at first calving in Italian Holsteins

Age at first calving (AFC) represents the nonproductive period of ∼2 yr in Holstein cows, and thus, it has a relevant effect on the cost of rearing replacements in the dairy herd. In the present study, we aimed to evaluate genetic and genomic aspects of AFC in the Italian Holstein population. Data of 4,206,218 heifers with first calving between 1996 and 2020 were used. Age at first calving averaged 26.09 ± 3.07 mo and decreased across years. Heritability was estimated using a linear animal model which included the fixed effects of herd-year-season of birth and classes of gestation length, and the random animal additive genetic effect fitted to a pedigree-based relationship matrix. The EBV and genomically EBV (GEBV) were obtained, and they were standardized to mean 100 and standard deviation 5, where animals above the mean are those contributing to reduce AFC. Heritability estimates of AFC ranged from 0.031 to 0.045. The trend of sires' GEBV was favorable and indicated a reduced AFC across years. Approximate genetic correlations between GEBV of AFC and GEBV of other economically important traits were calculated on a subset of genotyped females born after 2015. Moderate favorable associations of AFC with production traits (0.39-0.51), udder depth (0.40), interval from first to last insemination in heifer (-0.43), and longevity (0.34) were assessed. Overall, the greatest lifetime productive performances and most favorable days open in first lactation were observed when heifers calved at 22 to 23 mo. In contrast, progeny of sires with GEBV of AFC above the mean yielded more milk, fat, and protein in first lactation, and had shorter days open than progeny of sires with GEBV of AFC below the mean. Results suggested that breeding strategies to improve AFC should be pursued, also considering genetic correlations between AFC and traits which are already part of the Italian Holstein breeding objective. The inclusion of AFC in an aggregate index is expected to contribute to enhance farm income.

Complicated Falciparum Malarial ARDS Requiring Noninvasive Support

Severe plasmodium falciparum infection can induce respiratory distress and clinical ARDS in children, requiring intensive care admission and respiratory support. We present 3 cases of imported malarial acute respiratory distress syndrome requiring noninvasive ventilation in the pediatric intensive care unit, in the absence of any cerebral involvement. Radiological features and their relationship with severe hematological complications are also illustrated.

Genetic and nongenetic variation of heifer fertility in Italian Holstein cattle

Excellent fertility performance is important to maximize farmers' profit and to reduce the number of culled animals. Although female fertility of adult cows has been included in Italian Holstein breeding objectives since 2009, little has been done to quantify genetic variation of heifer fertility characteristics so far. The aim of the present study was to estimate genetic parameters of 4 fertility traits in nulliparous Italian Holstein heifers and to develop an aggregate selection index to improve heifer fertility. Data were retrieved from the national fertility database and included information on insemination, calving, and pregnancy diagnosis dates. The investigated phenotypes (mean ± standard deviation) were age at first insemination (AFI, mo; 17.25 ± 2.89), nonreturn rate at 56 d from the first insemination (NRR56, binary; 0.78 ± 0.41), conception rate at first insemination (CR, binary; 0.61 ± 0.49), and interval from first to last insemination (IFL, d; 26.09 ± 51.85). Genetic parameters were estimated using a 4-trait animal model that included the following fixed effects: herd-year of birth and month of birth for AFI, and herd-year-season of birth and month-year of insemination for IFL, NRR56, and CR; the animal additive genetic effect (fitted to the pedigree-based relationship matrix) was considered as a random term. An aggregate index was developed from the estimated additive genetic (co)variance matrix by considering CR as the breeding goal and AFI, NRR56, and IFL as selection criteria. Heritability estimates from average covariance matrices ranged from 0.012 (CR) to 0.015 (IFL), with the exception of AFI (0.071). Conception rate at first insemination was strongly correlated with both IFL (-0.730) and NRR56 (0.668), and weakly to AFI (-0.065), and the relative emphasis placed on each selection criteria in the aggregate index was 10%, 47%, and 43% for AFI, IFL, and NRR56, respectively. The results of the present study suggest that heifer fertility should be considered as an additional trait in the breeding objectives of Italian Holstein.

Delayed tension hemothorax after chest trauma in children

Blunt chest injury is commonly observed in the Pediatric Emergency Department and Intensive Care Unit since up to 30% of children with traumatic injury sustain injury to the thorax. Differently from adults, who present with concomitant rib or sternoclavicular fractures in 70% of cases, more than half of childhood chest injuries occur without any bone fracture, mostly causing lung contusions. This lower rate of rib fractures and near absence of flail chest in children may be due to greater elasticity of the pediatric cartilaginous and bony skeleton. Whenever a rib fracture is present, underlying complications should be evaluated carefully (i.e., air leaks or blood effusions). Depending on the trauma mechanism, even minor injuries should raise the suspicion of pathologic bone fractures.

Single feature constrained manual registration method for Augmented Reality applications in gynecological laparoscopic interventions

Augmented Reality (AR) can avoid some of the drawbacks of Minimally Invasive Surgery and may provide opportunities for developing innovative tools to assist surgeons. In laparoscopic surgery, the achievement of easy and sufficiently accurate registration is an open challenge. This is particularly true in procedures, such as laparoscopic abdominal Sacro-Colpopexy, where there is a lack of a sufficient number of visible anatomical landmarks to be used as a reference for registration. In an attempt to address the above limitations, we developed and preliminarily testes a constrained manual procedure based on the identification of a single anatomical landmark in the laparoscopic images, and the intraoperative measurement of the laparoscope orientation. Tests in a rigid in-vitro environment show good accuracy (median error 2.4 mm obtained in about 4 min) and good preliminary feedback from the technical staff who tested the system. Further experimentation in a more realistic environment is needed to validate these positive results. Clinical Relevance - This paper provides a new registration method for the development of AR educational videos and AR-based navigation systems for laparoscopic interventions.

A Rendering Engine for Integral Imaging in Augmented Reality Guided Surgery. Annu Int Conf IEEE Eng Med Biol Soc 2022;2022:2693-2696. [PMID: 36086410 DOI: 10.1109/embc48229.2022.9871806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

In the field of image-guided surgery, Augmented Reality wearable displays are a widely studied and documented technology for their ability to provide egocentric vision together with the overlap between real and virtual content. In particular, optical see-through (OST) displays have the advantage of maintaining visual perception of the real world. However, OST displays suffer from vergeance-accomodation conflict when virtual content is superimposed on real world. Furthermore, the calibration methods required to achieve geometric consistency between real and virtual are inherently error-prone. One of the solutions, already studied, to these problems is to use of integral imaging displays. In this paper we present an easy and straightforward real-time rendering strategy implemented in modern OpenGL to show the 3D image of a virtual object on a wearable OST display deploying the integral imaging approach. Clinical Relevance- The algorithm proposed open the way towards more effective AR surgical navigation in terms of comfort of the AR experience and accuracy of the AR guidance.

Augmented Reality as a Tool to Guide Patient-Specific Templates Placement in Pelvic Resections

Patient-specific templates (PST) have become a useful tool for guiding osteotomy in complex surgical scenarios such as pelvic resections. The design of the surgical template results in sharper, less jagged resection margins than freehand cuts. However, their correct placement can become difficult in some anatomical regions and cannot be verified during surgery. Conventionally, pelvic resections are performed using Computer Assisted Surgery (CAS), and in recent years Augmented Reality (AR) has been proposed in the literature as an additional tool to support PST placement. This work presents an AR task to simplify and improve the accuracy of the positioning of the template by displaying virtual content. The focus of the work is the creation of the virtual guides displayed during the AR task. The system was validated on a patient-specific phantom designed to provide a realistic setup. Encouraging results have been achieved. The use of the AR simplifies the surgical task and optimizes the correct positioning of the cutting template: an average error of 2.19 mm has been obtained, lower than obtained with state-of-the-art solutions. In addition, supporting PST placement through AR guidance is less time-consuming than the standard procedure that solely relies on anatomical landmarks as reference.

Vitamin D and tuberculosis in children: a role in the prevention or treatment of the disease?

Despite the growing number of published studies, the role of vitamin D in the prevention or treatment of tuberculosis remains unclear. In this review we analyze current scientific literature to provide evidence about the relationship between vitamin D and TB, with a special focus on the pediatric population. While in vitro studies have shown relevant antimycobacterial immune-stimulatory and immunosuppressive effects of vitamin D, this has not panned out in vivo with active TB. On the contrary, there is some evidence that this tool could work as prevention - both against TB infection as well as progression from latent to active infection. However, only a few studies have evaluated this correlation in children. The potential link between tuberculosis and vitamin D levels is promising. If effective, vitamin D supplementation of at-risk populations would be an affordable public health intervention, particularly in light of the worldwide increase in identified TB cases and drug-resistance. Vitamin D might represent a new, affordable, safe and easy to access drug for the prevention and treatment of TB. For stronger evidence, considering the features of infection (relative low incidence of reactivation of latent infection in immunocompetent patients) we need clinical trials with large numbers of participants conducted in endemic regions with a prolonged follow-up time.

Insights on Human Small Heat Shock Proteins and Their Alterations in Diseases

The family of the human small Heat Shock Proteins (HSPBs) consists of ten members of chaperones (HSPB1-HSPB10), characterized by a low molecular weight and capable of dimerization and oligomerization forming large homo- or hetero-complexes. All HSPBs possess a highly conserved centrally located α-crystallin domain and poorly conserved N- and C-terminal domains. The main feature of HSPBs is to exert cytoprotective functions by preserving proteostasis, assuring the structural maintenance of the cytoskeleton and acting in response to cellular stresses and apoptosis. HSPBs take part in cell homeostasis by acting as holdases, which is the ability to interact with a substrate preventing its aggregation. In addition, HSPBs cooperate in substrates refolding driven by other chaperones or, alternatively, promote substrate routing to degradation. Notably, while some HSPBs are ubiquitously expressed, others show peculiar tissue-specific expression. Cardiac muscle, skeletal muscle and neurons show high expression levels for a wide variety of HSPBs. Indeed, most of the mutations identified in HSPBs are associated to cardiomyopathies, myopathies, and motor neuropathies. Instead, mutations in HSPB4 and HSPB5, which are also expressed in lens, have been associated with cataract. Mutations of HSPBs family members encompass base substitutions, insertions, and deletions, resulting in single amino acid substitutions or in the generation of truncated or elongated proteins. This review will provide an updated overview of disease-related mutations in HSPBs focusing on the structural and biochemical effects of mutations and their functional consequences.

Escherichia coli resistance patterns, empiric and targeted antibiotic prescriptions in children: a single center experience

BACKGROUND AND AIM

Antibiotic resistance represents one of the major public health issues, due to the potential future ineffectiveness of available antibiotics. However, epidemiological studies on E. coli antibiotic resistance patterns in the pediatric population are limited.

METHODS

We conducted a retrospective analysis on children younger than 18 years of age admitted to the Department of Pediatrics from April 2016 to April 2018 with E. coli isolation on biological materials.

RESULTS

205 subjects were included in the study (mean age 1.6 years). We found an overall low rate of resistance of E. coli isolates to Amoxicil-lin/Clavulanate (20%), Cephalosporins (6.3%) and Aminoglycosides (6.3%), while no isolates were resistant to Carbapenems. Presence of invasive devices and intensive care admissions were as-sociated with resistance to Cephalosporines (P < 0.001; OR 9.21, 95% CI 2.7 - 31.39) and Amino-glycosides (P < 0.004; OR 5.42, 95% CI 1.71 - 17.15), while no factors associated with resistance to the other antibiotics were found.

CONCLUSIONS

Aminoglycosides and Cephalosporins were frequently used as empiric therapy, whereas targeted therapies aimed at sparing these classes of antibiotics once antibiograms were available have not always been established. These data may inform local antimicrobial stewardship and guide the development of programs aiming at a better use of antibiotics.

Life-threatening complications of streptococcal sepsis: a PICU contemporary series

Background

Life-threatening streptococcal sepsis nowadays represents an uncommon event in previously healthy infants and children. Critically ill patients suffering from severe streptococcal sepsis complications may present with pre-antibiotic era clinical pictures and require a timely clinical approach to achieve restitutio ad integrum.

Results

We report a series of four patient groups affected by an uncommon life-threatening streptococcal sepsis, each of them exhibiting some distinct features. Streptococcus Agalactiae sepsis was associated with cerebral thrombotic/ischaemic lesions, whereas severe cardiogenic shock was prominent in the Streptococcus Viridans group; Streptococcus Faecalis and β-hemolytic group A Streptococcus patients mostly reported lung complications.

Conclusions

Previous antibiotic treatments should not delay aggressive treatment in the intensive care setting. Early diagnostic suspicion, as well as appropriate and aggressive treatment provided within an intensive care setting are crucial for the clinical outcome.

Ecotoxicological effects of new generation pollutants (nanoparticles, amoxicillin and white musk) on freshwater and marine phytoplankton species

Phytoplankton occupies a key trophic level in aquatic ecosystems. Chemical impacts on these primary producers can disrupt the integrity of an entire ecosystem. Two freshwater (Pseudokirchneriella subcapitata-Ps and Scenedesmus obliquus-S) and three marine (Phaeodactylum tricornutum-P, Isochrysis galbana-I, Tetraselmis suecica-T) microalgae species were exposed to dilutions of four chemicals: nanoparticles (n-TiO₂, n-ZnO), amoxicillin (antibiotic), and white musk (personal care fragrance) to determine the half maximal effective concentration (EC₅₀) after 72 h of exposure under standardized and controlled environmental conditions. Cell cultures were exposed to EC₅₀ to determine sublethal effects (72 h) based on biochemical (chlorophylls a, b, c), molecular (changes in outer cell wall structure), and morphological alterations. We report for the first time EC₅₀ values for nanoparticles in not standardized species (S, I and T) and for amoxicillin and white musk in all tested species. Standardized species (Ps and P) were less sensitive than non-standardized in some cases. Fourier-transformed infrared spectroscopy showed a marked spectral alteration (from 10.44% to 90.93%) of treated cultures compared to negative controls; however, principal component analysis disclosed no differences in molecular alteration between the five microalgae species or the two aquatic habitats considered. There was a significant decrease in chlorophylls content in all species exposed to EC₅₀ compared to controls (Kruskal Wallis test; p < 0.05). There was a significant increase in cell-size (Mann-Whitney U test; p < 0.05) in I, P and T exposed to white musk and S exposed to amoxicillin. Findings highlight ecotoxicological risks from new generation pollutants for primary producers in aquatic ecosystems.

Seroprevalence of anti-SARS-CoV-2 IgG antibodies in children with household exposure to adults with COVID-19: Preliminary findings

Weather and the susceptibility of children to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is still a debated question and currently a hot topic, particularly in view of important decisions regarding opening schools. Therefore, we performed this prospective analysis of anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies in children with known household exposure to SARS-CoV-2 and compared their IgG status with the other adults exposed to the index case in the same household. A total of 30 families with a documented COVID-19 index case were included. A total of 44 out of 80 household contacts (55%) of index patients had anti SARS-CoV-2 IgG antibodies. In particular, 16/27 (59,3%) adult partners had IgG antibodies compared with 28/53 (52,3%) of pediatric contacts (p > .05). Among the pediatric population, children ≥5 years of age had a similar probability of having SARS-CoV-2 IgG antibodies (21/39, 53.8%) compared to those less than 5 years old (7/14, 50%) (p > .05). Adult partners and children also had a similar probability of having SARS-CoV-2 IgG antibodies. Interestingly, 10/28 (35.7%) of children and 5/27 (18.5%) of adults with SARS-CoV-2 IgG antibodies were previously diagnosed as COVID-19 cases. Our study shows evidence of a high rate of IgG antibodies in children exposed to SARS-CoV-2. This report has public health implications, highlighting the need to establish appropriate guidelines for school openings and other social activities related to childhood.

A Systematic Review on Methods and Tools for the In Situ Fenestration of Aortic Stent-Graft

In situ fenestration of stent-graft represents a potential option for the treatment of aortic diseases in patients unsuitable for standard endovascular repair. The best fenestration strategy to restore perfusion of collateral vessels after their coverage by an endograft depends mainly on the anatomical area. Several tools are employed as fenestration devices, including needles, radiofrequency probes, and laser systems, used in conjunction with other instrumentation to provide enough support and stability during the procedure. In this systematic review, the approaches to reach the correct fenestration site both in human, animal, and in in vitro environments are described and discussed, highlighting advantages and limitations. Both commercial and dedicated solutions for the intraoperative modification of the fabric material are reported as well. The clinical interest in this procedure has so far encouraged researchers to develop and refine both methods and tools to solve the current limitations of this technique, intending to extend the indications for endovascular treatment to a broader range of patients.

Variation in neutrophil to lymphocyte ratio (NLR) as predictor of outcomes in metastatic renal cell carcinoma (mRCC) and non-small cell lung cancer (mNSCLC) patients treated with nivolumab

BACKGROUND

An elevated pre-treatment neutrophil to lymphocytes ratio (NLR) is associated with poor prognosis in various malignancies. Optimal cut-off is highly variable across studies and could not be determined individually for a patient to inform his prognosis. We hypothesize that NLR variations could be more useful than baseline NLR to predict progression-free survival (PFS) and overall survival (OS) in patients (pts) receiving anti-PD1 treatment.

PATIENTS AND METHODS

All pts with metastatic renal cell carcinoma (mRCC) and metastatic non-small cell lung cancer (mNSCLC) who received anti-PD1 nivolumab monotherapy in second-line setting or later were included in this French multicentric retrospective study. NLR values were prospectively collected prior to each nivolumab administration. Clinical characteristics were recorded. Associations between baseline NLR, NLR variations and survival outcomes were determined using Kaplan-Meier's method and multivariable Cox regression models.

RESULTS

161 pts (86 mRCC and 75 mNSCLC) were included with a median follow-up of 18 months. On the whole cohort, any NLR increase at week 6 was significantly associated with worse outcomes compared to NLR decrease, with a median PFS of 11 months vs 3.7 months (p < 0.0001), and a median OS of 28.5 months vs. 18 months (p = 0.013), respectively. In multivariate analysis, NLR increase was significantly associated with worse PFS (HR 2.2; p = 6.10^-5) and OS (HR 2.1; p = 0.005). Consistent results were observed in each cohort when analyzed separately.

CONCLUSION

Any NLR increase at week 6 was associated with worse PFS and OS outcomes. NLR variation is an inexpensive and dynamic marker easily obtained to monitor anti-PD1 efficacy.

Quartz Crystal Resonator Sensor With Printed-on-Crystal Coil for Dual-Harmonic Electromagnetic Contactless Interrogation

A novel quartz crystal resonator (QCR) sensor with a printed-on-crystal conductive coil, named sensor coil, is presented. The sensor coil electromagnetically coupled to an external readout coil allow to perform contactless interrogation of the QCR working as a stand-alone sensor unit. A frequency-domain readout technique is adopted that allows dual-harmonic operation by detecting the QCR frequencies of the fundamental and third harmonic, and offers first-order independence from the stand-off distance between the sensor and the readout unit. The QCR electrodes and sensor coil have been printed on a 330- [Formula: see text]-thick bare AT-cut quartz crystal exploiting the aerosol jet printing technology. The fabricated QCR sensor has reference values of the fundamental and third harmonic frequencies at 4.77 and 14.22 MHz, respectively. Distance-independent contactless operation has been demonstrated for distances up to 12 mm. The readout frequencies deviate from reference values less than 10 and 90 ppm for the fundamental and third harmonic, respectively, thus validating the proposed principle.

Novel EM Guided Endovascular Instrumentation for In Situ Endograft Fenestration

Objective: This work aims at providing novel endovascular instrumentation to overcome current technical limitations of in situ endograft fenestration including challenges in targeting the fenestration site under fluoroscopic control and supplying mechanical support during endograft perforation. Technology: Novel electromagnetically trackable instruments were developed to facilitate the navigation of the fenestration device and its stabilization at the target site. In vitro trials were performed to preliminary evaluate the proposed instrumentation for the antegrade in situ fenestration of an aortic endograft, using a laser guidewire designed ad hoc and the sharp end of a commercial endovascular guidewire. Results: In situ fenestration was successfully performed in 22 trials. A total of two laser tools were employed since an over bending of laser guidewire tip, due to its manufacturing, caused the damage of the sensor in the first device used. Conclusions: Preliminary in vitro trials demonstrate the feasibility of the proposed instrumentation which could widespread the procedure for in situ fenestration. The results obtained should be validated performing animal studies. Clinical Impact: The proposed instrumentation has the potential to expand indications for standard endovascular aneurysm repair to cases of acute syndromes.

The inaccuracy of LaFarge equations estimating the oxygen consumption in children under 3 years age

Accurate oxygen consumption measurement (VO₂), is essential to obtain a reliable hemodynamic assessment, particularly in patients with congenital heart diseases undergoing cardiac catheterization. LaFarge equations can be unreliable in predicting VO₂, particularly in the pediatric population. In a clinical setting, these inaccurate estimates can lead to important hemodynamic parameter miscalculations, with possible therapeutic or diagnostic consequences. Our aim is to validate LaFarge equations (the most widely used for estimating VO₂) and compare them with direct measurement in children during cardiac catheterization in the cath lab. We performed a prospective observational study in 21 patients (0-3 years of age) with different congenital cardiac diseases, scheduled for diagnostic cardiac catheterization. Under general anesthesia and mechanical ventilation, VO₂ was measured directly with a metabolic module in our cath lab, and also estimated using LaFarge equations. Statistical analysis included Bland-Altman plots, Pearson coefficient and percentage error, among others. LaFarge equations overestimated VO₂ values in all study patients. Therefore, in pediatric patients under 3 years of age, the use of direct VO₂ measurement methods are more accurate and acceptable than LaFarge equations.

Forearm lengthening and prosthetic management in children with transverse congenital forearm deficiency

In cases of transverse congenital forearm deficiency, achieving a good prosthesis fit during childhood remains a challenge. Ulnar lengthening is a treatment option for improving the prosthesis fit. The objective of this study was to evaluate surgical ulnar lengthening and the subsequent prosthesis fit. We reviewed four cases of ulnar lengthening in children with transverse congenital forearm deficiency. The procedure was evaluated in terms of the duration of lengthening, increase in ulnar length and healing index. The elbow range of motion, functional outcome (Prosthetic Upper Extremity Functional Index, PUFI) and time spent using the prosthesis per day were evaluated. The mean age at the time of the lengthening procedure was 3.5 years, the mean duration of lengthening was 58.3 days, the mean length gain was 21 mm, and the mean healing index was 70.1 days/cm. Elbow range of motion was restricted in one patient (100°-140°) and full in the other three patients. Based on the PUFI, 88.4% of activities were performed without the prosthesis. Children only used their prosthesis to perform specific tasks. Given the high complication rate and the lack of prosthesis use during daily activities, the main indication for forearm lengthening is a very short forearm that prevents prosthesis fitting. This procedure should be performed later in life - in adolescence.

Guidance on validation and qualification of processes and operations involving radiopharmaceuticals

BACKGROUND

Validation and qualification activities are nowadays an integral part of the day by day routine work in a radiopharmacy. This document is meant as an Appendix of Part B of the EANM "Guidelines on Good Radiopharmacy Practice (GRPP)" issued by the Radiopharmacy Committee of the EANM, covering the qualification and validation aspects related to the small-scale "in house" preparation of radiopharmaceuticals. The aim is to provide more detailed and practice-oriented guidance to those who are involved in the small-scale preparation of radiopharmaceuticals which are not intended for commercial purposes or distribution.

RESULTS

The present guideline covers the validation and qualification activities following the well-known "validation chain", that begins with editing the general Validation Master Plan document, includes all the required documentation (e.g. User Requirement Specification, Qualification protocols, etc.), and leads to the qualification of the equipment used in the preparation and quality control of radiopharmaceuticals, until the final step of Process Validation.

CONCLUSIONS

A specific guidance to the qualification and validation activities specifically addressed to small-scale hospital/academia radiopharmacies is here provided. Additional information, including practical examples, are also available.

Automatic carotid centerline extraction from three-dimensional ultrasound Doppler images

Vessel lumen centerline extraction is an important issue for the intra-operative guidance of endovascular instruments; furthermore, vessel centerline is often used as a reference position in many hemodynamic studies, especially in carotid arteries. In this work we propose an innovative method for the extraction of carotid vessels centerline from three-dimensional Color Doppler ultrasound images. The method was tested on carotid Color Doppler images of eighteen healthy subjects and validated by calculating the Euclidean distances between the centerlines detected by the algorithm and those manually annotated by two experts in the corresponding original US volumes. The results show that the proposed approach can accurately estimate the actual centerline with an average error of 1.08 ± 0.54 mm. Furthermore, the method is completely automatic and therefore suitable for the aforementioned purposes.

Augmented reality system for freehand guide of magnetic endovascular devices

Magnetic guide of endovascular devices or magnetized therapeutic microparticles to the specific target in the arterial tree is increasingly studied, since it could improve treatment efficacy and reduce side effects. Most proposed systems use external permanent magnets attached to robotic manipulators or magnetic resonance imaging (MRI) systems to guide internal carriers to the region of treatment. We aim to simplify this type of procedures, avoiding or reducing the need of robotic arms and MRI systems in the surgical scenario. On account of this we investigated the use of a wearable stereoscopic video see-through augmented reality system to show the hidden vessel to the surgeon; in this way, the surgeon is able to freely move the external magnet, following the showed path, to lead the endovascular magnetic device towards the desired position. In this preliminary study, we investigated the feasibility of such an approach trying to guide a magnetic capsule inside a vascular mannequin. The high rate of success and the positive evaluation provided by the operators represent a good starting point for further developments of the system.

Position paper on requirements for toxicological studies in the specific case of radiopharmaceuticals

This is a position paper of the Radiopharmacy Committee of the EANM (European Association of Nuclear Medicine) addressing toxicology studies for application of new diagnostic and therapeutic radiopharmaceuticals (RP) that are not approved (i.e., not having a marketing authorization or a monograph in the European Pharmacopoeia), excluding endogenous and ubiquitous substances in humans. This paper discusses the requirements for clinical trials with radiopharmaceuticals for clinical research applications, not necessarily intended to aim at a marketing authorization. If marketing authorization is intended, scientific advice of the competent authorities is mandatory and cannot be replaced by this position paper. The position paper reflects the view of the Radiopharmacy Committee of the EANM and can be used as a basis for discussions with the responsible authorities.

Basic Endovascular Skills Trainer: A surgical simulator for the training of novice practitioners of endovascular procedures

In recent years the clinical interest for structured training in endovascular procedures has increased. Such procedures respect the physical integrity of the patient and at the same time ensure good therapeutic results. This study describes the development and testing of the B.E.S.T. (Basic Endovascular Skills Trainer) simulator. The B.E.S.T is an innovative physical endovascular simulator to learn basic skills of endovascular surgery. The simulator was tested by 25 clinicians with different levels of experience: novices, intermediates, and experts. All clinicians agree on affirming the importance of training in endovascular surgery; in particular they consider the B.E.S.T a valid simulator to learn specific basic skills of vascular surgery.

New training methods based on mixed reality for interventional ultrasound: Design and validation

Currently the learning model for ultrasound imaging diagnosis and intervention follows a traditional approach based on learning by doing but this model exposes the patient to the whole learning curve of the novice. In order to enable training in a safe environment without compromising patient's health we have developed and demonstrated face, content and construct validity of a hybrid simulator for ultrasound-guided biopsy. This hybrid simulator is able to provide a support to acquire skills in term of 3D perception and hand-eye coordination thanks to a mixed reality visualization that allows accurate and easy planning of probe position/orientation and needle trajectory to reach the target.

A 3D sparse motion field filtering for quantitative analysis of fascial layers mobility based on 3D ultrasound scans

In the last few years, there has been an increasing interest in the role of deep fascia mobility in musculoskeletal dynamics and chronic pain mechanisms. In a previous paper we presented an innovative semiautomatic approach to evaluate the 3D motion of the fascia using ultrasound (US) imaging, generating a sparse deformation vector field. This paper presents an improvement of our original method, focusing on the filtering of the sparse vector field and its validation. Moreover, in order to evaluate the performance of the algorithm, a method is proposed to generate synthetic deformation vector fields, including: expansion, rotation, horizontal shear, and oblique shear components. Preliminary tests on the final synthetic deformation vector fields showed promising results. Further experiments are required in order to optimize the tuning of the algorithm.

Hybrid simulation using mixed reality for interventional ultrasound imaging training

PURPOSE

Ultrasound (US) imaging offers advantages over other imaging modalities and has become the most widespread modality for many diagnostic and interventional procedures. However, traditional 2D US requires a long training period, especially to learn how to manipulate the probe. A hybrid interactive system based on mixed reality was designed, implemented and tested for hand-eye coordination training in diagnostic and interventional US.

METHODS

A hybrid simulator was developed integrating a physical US phantom and a software application with a 3D virtual scene. In this scene, a 3D model of the probe with its relative scan plane is coherently displayed with a 3D representation of the phantom internal structures. An evaluation study of the diagnostic module was performed by recruiting thirty-six novices and four experts. The performances of the hybrid (HG) versus physical (PG) simulator were compared. After the training session, each novice was required to visualize a particular target structure. The four experts completed a 5-point Likert scale questionnaire.

RESULTS

Seventy-eight percentage of the HG novices successfully visualized the target structure, whereas only 45% of the PG reached this goal. The mean scores from the questionnaires were 5.00 for usefulness, 4.25 for ease of use, 4.75 for 3D perception, and 3.25 for phantom realism.

CONCLUSIONS

The hybrid US training simulator provides ease of use and is effective as a hand-eye coordination teaching tool. Mixed reality can improve US probe manipulation training.

An optimal design for patient-specific templates for pedicle spine screws placement

BACKGROUND

Currently, pedicle screws are positioned using a free-hand technique or under fluoroscopic guidance, with error in the range 10-40%, depending on the skill of the surgeon.

METHODS

After spine CT acquisition, each vertebra is segmented and the surgeon plans screw positioning in a virtual environment, then the template is designed around the chosen trajectories. This design is based on surgical and mechanical considerations to obtain an optimal solution to guarantee template stability, simple positioning and minimized intervention invasiveness. In vitro evaluation on synthetic spine models and ex vivo animal tests on porcine specimens were performed, with the insertion of 28 Kirschner wires.

RESULTS

During the in vitro tests, all the surgeons rendered positive evaluations regarding the device and considered template placement to be easy. Ex vivo tests were evaluated by CT examination, which showed that 96.5% of the Kirschner wires had been correctly inserted.

CONCLUSIONS

The proposed solution is a promising, simple, highly precise, low-cost solution to safely performing posterior stabilization. Such a solution would be of interest even in hospitals in which a few spine interventions are performed per year, and for which it is not reasonable to purchase the equipment required for robotic or navigated approaches.

Electromagnetic navigation platform for endovascular surgery: how to develop sensorized catheters and guidewires

BACKGROUND

Endovascular procedures are nowadays limited by difficulties arising from the use of 2D images and are associated with dangerous X-ray exposure and the injection of nephrotoxic contrast medium.

METHODS

An electromagnetic navigator is proposed to guide endovascular procedures with reduced radiation dose and contrast medium injection. Five DOF electromagnetic sensors are calibrated and used to track in real time the positions and orientation of endovascular catheters and guidewires, while intraoperative 3D rotational angiography is used to acquire 3D models of patient anatomy. A preliminary prototype is developed to prove the feasibility of the system using an anthropomorphic phantom.

RESULTS

The spatial accuracy of the system was evaluated during 70 targeting trials obtaining an overall accuracy of 1.2 ± 0.3 mm; system usability was positively evaluated by three surgeons.

CONCLUSIONS

The strategy proposed to sensorize endovascular instruments paves the way for the development of surgical strategies with reduced radiation dose and contrast medium injection. Further in vitro, animal and clinical experiments are necessary for complete surgical validation.