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Objectives: The aim of this study was to identify cone-beam computed tomography (CBCT) protocols that offer an optimal balance between effective dose (ED) and 3D model for orthognathic virtual surgery planning, using CT as a reference, and to assess whether such protocols can be defined based on technical image quality metrics., Methods: Eleven CBCT (VISO G7, Planmeca Oy, Helsinki, Finland) scan protocols were selected out of 32 candidate protocols, based on ED and technical image quality measurements. Next, an anthropomorphic RANDO SK150 phantom was scanned using these 11 CBCT protocols and 2 CT scanners for bone quantity assessments. The resulting DICOM (Digital Imaging and Communications in Medicine) files were converted into Standard Tessellation Language (STL) models that were used for bone volume and area measurements in the predefined orbital region to assess the validity of each CBCT protocol for virtual surgical planning., Results: The highest CBCT bone volume and area of the STL models were obtained using normal dose protocol (F2) and ultra-low dose protocol (J13), which resulted in 48% and 96% of the mean STL bone volume and 48% and 95% of the bone area measured on CT scanners, respectively., Conclusions: The normal dose CBCT protocol "F2" offered optimal bone area and volume balance for STL. The optimal CBCT protocol can be defined using contrast-to-noise ratio and modulation transfer function values that were similar to those of the reference CT scanners'. CBCT scanners with selected protocols can offer a viable alternative to CT scanners for acquiring STL models for virtual surgical planning at a lower effective dose., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology and the International Association of Dentomaxillofacial Radiology.)

Aim: Machine learning techniques have demonstrated success in predictive modeling across various clinical cases. However, few studies have considered predicting the use of multisectoral health and social services among older adults. This research aims to utilize machine learning models to detect high-risk groups of excessive health and social services utilization at early stage, facilitating the implementation of preventive interventions., Methods: We used pseudonymized data covering a four-year period and including information on a total of 33,374 senior citizens from Southern Finland. The endpoint was defined based on the occurrence of unplanned healthcare visits and the total number of different services used. Input features included individual's basic demographics, health status and past usage of healthcare resources. Logistic regression and eXtreme Gradient Boosting (XGBoost) methods were used for binary classification, with the dataset split into 70% training and 30% testing sets., Results: Subgroup-based results mirrored trends observed in the full cohort, with age and certain health issues, e.g. mental health, emerging as positive predictors for high service utilization. Conversely, hospital stay and urban residence were associated with decreased risk. The models achieved a classification performance (AUC) of 0.61 for the full cohort and varying in the range of 0.55-0.62 for the subgroups., Conclusions: Predictive models offer potential for predicting future high service utilization in the older adult population. Achieving high classification performance remains challenging due to diverse contributing factors. We anticipate that classification performance could be increased by including features based on additional data categories such as socio-economic data.

Substituting plastics with circular and sustainable alternatives has increasingly become a priority. Protective coatings, crucial components in numerous industries, are now in demand for biodegradable options to replace their plastic-based counterparts. Being one of nature's most abundant components, lignin remains underutilized, and this study focuses on investigating its potential for the production of biobased coatings. The method used here involved formulating coating suspensions by mixing methylcellulose and organosolv lignin powders and adding water to the mixture. Glass wafers were coated with the formulated suspensions using spin-coating. The morphology of the coated surfaces was assessed using optical and scanning electron microscopy. In addition, the wettability of the surfaces was examined through water contact angle experiments, and a numerical model was introduced to predict the water contact angle evolution over time. The results revealed that the sample coated with a 2.5 wt% lignin suspension exhibited the highest initial contact angle (114°), with a decreasing trend as the lignin fraction increases. Moreover, coatings with 3.5 wt% lignin and above exhibited lower surface coverage due to lignin particle aggregation and surface defects. By approximating the water droplet on the surface as a spherical cap, the introduced numerical model successfully predicted the time-dependent evolution of the water contact angle by showing strong alignment with experimental results. Taken altogether, we have showcased here a method for modifying coating properties-in a practical sense from water-absorbent to splash-proof-using readily available forest-based materials. This advancement is paving the way for sustainable protective packaging, aiming to replace styrofoam in the electronics and food industries.

Background: To compare the diagnostic value of 120-kV with conventional 96-kV Cone-Beam CT (CBCT) of the temporal bone after cochlear implant (CI) surgery., Methods: This retrospective study included CBCT scans after CI surgery between 06/17 and 01/18. CBCT allowed examinations with 96-kV or 120-kV; other parameters were the same. Two radiologists independently evaluated following criteria on 5-point Likert scales: osseous spiral lamina, inner and outer cochlear wall, semi-circular canals, mastoid trabecular structure, overall image quality, metal and motion artefacts, depiction of intracochlear electrode position and visualisation of single electrode contacts. Effective radiation dose was assessed., Results: Seventy-five patients (females, n = 39 [52.0%], mean age, 55.8 ± 16.5 years) were scanned with 96-kV (n = 32, 42.7%) and 120-kV (n = 43, 57.3%) protocols including CI models from three vendors (vendor A n = 7; vendor B n = 43; vendor C n = 25). Overall image quality, depiction of anatomical structures, and electrode position were rated significantly better in 120-kV images compared to 96-kV (all p < = 0.018). Anatomical structures and electrode position were rated significantly better in 120-kV CBCT for CI models from vendor A and C, while 120-kV did not provide improved image quality in CI models from vendor B. Radiation doses were significantly higher for 120-kV scans compared to 96-kV (0.15 vs. 0.08 mSv, p < 0.001)., Conclusions: 120-kV and 96-kV CBCT provide good diagnostic images for the postoperative CI evaluation. While 120-kV showed improved depiction of temporal bone and CI electrode position compared to 96-kV in most CI models, the 120-kV protocol should be chosen wisely due to a substantially higher radiation exposure., (© 2024. The Author(s).)

Background: There is a need for better adoption of technology to meet the needs of home care professionals, older people, and informal caregivers., Methods: Mixed methods were used to describe and analyse quantitative and qualitative data in a Finnish governmental programme called KATI. The study was three-fold: it 1) listed what kinds of technologies were piloted and deployed in a national study, 2) provided information from the perspectives of home care professionals about requirements to use technology by using focus-group interviews, and 3) assessed experiences of how the adoption of technology changes work and work processes over time by using repeated surveys. Informants in interviews (n = 25) and surveys (n = 90) were home care professionals, who also described the perspectives of older people and informal caregivers. The conceptual models framing the study were adapted from the Technology Acceptance Model and DirVA PROVE-IT., Results: There were 80 technology pilots, in which variety of technologies were followed in home care. Familiarity with, commitment to and understanding of technology benefits were considered to be requirements for the technology to be used. The adoption of technology provided new skills and information about older people's wellbeing, realisation of treatment and new possibilities in home care. It developed new procedures to focus on older people's needs and motivated professionals by gained concrete aid. It enabled them to leave out some concrete procedures as unnecessary. On the other hand, there were also pessimistic and negative experiences when technology use provided nothing new or did not change anything., Conclusions: The adoption of technology is dependent on the technology and its integration into the prevailing service practice. When they both work, it is possible to leave out unnecessary procedures in care, allocate resources and save time. It is possible to be aware of older people's safety and how they cope at home, find new ways to get involved in older people's lives, gain insight, and make changes at work. Continuous on-site training, modifications in service practices and communication throughout organisations is needed., (© 2023. The Author(s).)

The electrode-generated intracochlear electrical field (EF) spreads widely along the scala tympani surrounded by poorly-conducting tissue and it can be measured with monopolar transimpedance matrix (TIM mp ). Bipolar TIM (TIM bp ) allows estimations of local potential differences. With TIM mp , the correct alignment of the electrode array can be assessed, and TIM bp may be useful in more subtle evaluations of the electrode array's intracochlear location. In this temporal bone study, we investigated the effect of the cross-sectional scala area (SA) and the electrode-medial-wall distance (EMWD) on both TIM mp and TIM bp using three types of electrode arrays. Also, multiple linear regressions based on the TIM mp and TIM bp measurements were used to estimate the SA and EMWD. Six cadaver temporal bones were consecutively implanted with a lateral-wall electrode array (Slim Straight) and with two different precurved perimodiolar electrode arrays (Contour Advance and Slim Modiolar) for variation in EMWD. The bones were imaged with cone-beam computed tomography with simultaneous TIM mp and TIM bp measurements. The results from imaging and EF measurements were compared. SA increased from apical to basal direction (r = 0.96, p < 0.001). Intracochlear EF peak negatively correlated with SA (r = -0.55, p < 0.001) irrespective of the EMWD. The rate of the EF decay did not correlate with SA but it was faster in the proximity of the medial wall than in more lateral positions (r = 0.35, p < 0.001). For a linear comparison between the EF decaying proportionally to squared distance and anatomic dimensions, a square root of inverse TIM bp was applied and found to be affected by both SA and EMWD (r = 0.44 and r = 0.49, p < 0.001 for both). A regression model confirmed that together TIM mp and TIM bp can be used to estimate both SA and EMWD (R 2  = 0.47 and R 2  = 0.44, respectively, p < 0.001 for both). In TIM mp , EF peaks grow from basal to apical direction and EF decay is steeper in the proximity of the medial wall than in more lateral positions. Local potentials measured via TIM bp correlate with both SA and EMWD. Altogether, TIM mp and TIM bp can be used to assess the intracochlear and intrascalar position of the electrode array, and they may reduce the need for intra- and postoperative imaging in the future., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Today, digitalisation is strongly present in health and social care, and it increasingly affects the organisation of work, work requirements, tasks and tools. Due to the constant change in work, up-to-date knowledge is needed about these micro-level effects of digitalisation and how professionals experience the effects in their work. Furthermore, even though managers play a key role in implementing new digital services, their perceptions of the effects of digitalisation and whether they match the views of professionals remain unknown. This study examined how health and social care professionals and managers perceive the effects of digitalisation on the work of professionals., Methods: We used a qualitative approach and conducted eight semi-structured focus group interviews with health and social care professionals (n = 30) and 21 individual interviews with managers in 2020 in four health centres in Finland. The qualitative content analysis included both an inductive and a deductive approach., Results: Digitalisation was perceived to have changed professionals' 1) workload and pace, 2) the field and nature of work, 3) work community communication and interaction, and 4) information flow and security. Both professionals and managers identified effects such as accelerated work, reduction in workload, constant learning of technical skills, complicated work due to vulnerable information systems, and reduction in face-to-face encounters. However, managers did not bring up all the effects that professionals considered important, such as the creation of new work tasks, increased and duplicated work, or insufficient time to get acquainted with the systems., Conclusions: The findings suggest that some of the effects of digitalisation on professionals' work and changes in the workplace may receive too little or no recognition from managers. This increases the risk that the potential negative effects may be overlooked and that managers will adopt systems that do not support the work of professionals. To reach a common understanding of the effects of digitalisation, continuous discussions between employees and different management levels are required. This contributes to professionals' well-being and adaptation to changes, as well as the provision of quality health and social services., (© 2023. The Author(s).)

Background: Multi slice computed tomography (MSCT) is the most common used method in middle ear imaging. However, MSCT lacks the ability to distinguish the ossicular chain microstructures in detail resulting in poorer diagnostic outcomes. Novel cone beam computed tomography (CBCT) devices' image resolution is, on the other hand, better than MSCT resolution. The aim of this study was to optimize imaging parameters of a novel full body CBCT device to obtain optimal contrast to noise ratio (CNR) with low effective dose, and to optimize its clinical usability., Methods: Imaging of five anonymous excised human cadaver temporal bones, the acquisition of the effective doses and the CNR measurements were performed for images acquired on using Planmed XFI® full body CBCT device (Planmed Oy, Helsinki, Finland) with a voxel size of 75 µm. All images acquired from the specimens using 10 different imaging protocols varying from their tube current exposure time product (mAs) and tube voltage (kVp) were analyzed for eight anatomical landmarks and evaluated by three evaluators., Results: With the exception of protocol with 90 kVp 100 mAs, all other protocols used are competent to image the finest structures. With a moderate effective dose (86.5 µSv), protocol with 90 kV 450 mAs was chosen the best protocol used in this study. A significant correlation between CNR and clinical image quality of the protocols was observed in linear regression model. Using the optimized imaging parameters, we were able to distinguish even the most delicate middle ear structures in 2D images and produce accurate 3D reconstructions., Conclusions: In this ex vivo experiment, the new Planmed XFI® full body CBCT device produced excellent 2D resolution and easily created 3D reconstructions in middle ear imaging with moderate effective doses. This device would be suitable for middle ear diagnostics and for e.g., preoperative planning. Furthermore, the results of this study can be used to optimize the effective dose by selecting appropriate exposure parameters depending on the diagnostic task., (© 2023. The Author(s).)

With computed tomography (CT), the delicate structures of the inner ear may be hard to visualise, which a cochlear implant (CI) electrode array can further complicate. The usefulness of a novel cone-beam CT device in CI recipient's inner ear imaging was evaluated and the exposure parameters were optimised to attain adequate clinical image quality at the lowest effective dose (ED). Six temporal bones were implanted with a Cochlear Slim Straight electrode array and imaged with six different imaging protocols. Contrast-to-noise ratio was calculated for each imaging protocol, and three observers evaluated independently the image quality of each imaging protocol and temporal bone. The overall image quality of the inner ear structures did not differ between the imaging protocols and the most relevant inner ear structures of CI recipient's inner ear can be visualised with a low ED. To visualise the most delicate structures in the inner ear, imaging protocols with higher radiation exposure may be required., (© The Author(s) 2023. Published by Oxford University Press.)

Objectives: To compare the cone-beam computed tomography (CBCT) image quality and effective dose between low-dose scanning and standard manufacturer-recommended protocols among different CBCT units., Methods: Three human-equivalent phantoms were scanned using the ultra-low-dose (ULD), low dose (LD), and standard dose (STD) modes of ProMax 3D Mid (Planmeca Oy, Helsinki, Finland) and Orthophos SL (Sirona, Bensheim, German) for the CBCT images. The quality of the dental anatomical images was assessed by four experienced oral and maxillofacial radiologists using a 5-point Likert scale. OnDemand3D (Cybermed Co., Seoul, Korea) was used as the third-party software for viewing. The percentage of absolute agreement was calculated to determine intra- and interrater agreements among the observers. The effective doses for all CBCT scanning protocols were also calculated., Results: The STD protocol yielded a higher image quality than did the ULD and LD protocols in both ProMax 3D Mid and Orthophos SL. The ULD and LD protocols demonstrated an "acceptable-to-good" sense of visual perception of the CBCT images. The visibility scores significantly differed between the ULD and LD and the STD protocols in ProMax 3D Mid and Orthophos SL, except for the 120-kVp setting in ProMax 3D Mid. The average intra- and interrater agreement scores ranged from 0.63 to 0.89 and from 0.44 to 0.76, respectively. The ULD and LD protocols reduced the radiation dose sixfold compared with the STD protocol., Conclusions: High-tube-voltage protocols could remarkably reduce the imaging dose without degrading the image quality. Specifically, ULD and LD CBCT protocols may be adopted as routine practice for diagnosis and treatment planning.

Understanding of the viscoelastic behavior of a polymer is a prerequisite for its thermomechanical processing beyond laboratory scale. Utilizing rheological characterization is a powerful tool to comprehend the complex nature and time-dependent properties of macromolecular materials. Nevertheless, it consumes time as rheometry involves iterating experiments under several conditions to visualize the non-linear behavior of materials under varying conditions. The work hereunder examines the rheology of cellulosic aqueous suspensions prepared using cellulose fibers as the dispersed phase (Refcell and Storacell) and methylcellulose (MC) as the polymeric matrix. Interfacial phenomena between MC and cellulose fibers arise in particle laden systems with supramolecular structures formed by non-covalent interactions. Therefore, this study elucidates the rheological evolution of these interactions as a function of temperature and fiber concentration. This study displays how researchers may reduce the number of rheological experiments and save time utilizing a novel method based on a Bayesian optimization with Gaussian processes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Purpose: To evaluate fetal doses from extremity CBCT examinations at different stages of pregnancy and to investigate different methods of fetal dose optimization., Method: Fetal doses were measured in an anthropomorphic phantom for two CBCT examination protocols - knee and elbow. The measurements were made at three different heights representing the three trimesters during pregnancy and three different depths in the phantom. The effect of soft tissue layer, tube voltage, add-on device shield and body angulation on fetal dose were investigated., Results: The fetal doses in clinical examination protocols were in the range of 3.4 to 6.0 µGy during knee examinations and 2.9 to 7.7 µGy during elbow examinations depending on the depth of the fetus and the stage of pregnancy. A soft tissue layer representing variative body composition above abdomen region decreased the fetal dose up to 19 % in knee and up to 21 % in elbow examinations. Using lower tube voltage decreased the fetal doses up to 45 % (knee) and 51 % (elbow). An add-on device shield decreased the fetal doses up to 91 % (knee) and up to 75 % (elbow). Turning the body away from the device bore reduced the fetal doses up to 62 %. The conversion factor to convert an entrance surface dose to the fetal dose ranged from 0.4 to 0.6., Conclusions: The fetal doses from CBCT examinations of extremities are low and do not produce a concern about radiation detriment to the fetus. The most efficient way found to reduce the fetal dose was to use the add-on device shielding., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: Cone beam computed tomography (CBCT) images are being increasingly used to acquire three-dimensional (3D) models of the skull for additive manufacturing purposes. However, the accuracy of such models remains a challenge, especially in the orbital area. The aim of this study is to assess the impact of four different CBCT imaging positions on the accuracy of the resulting 3D models in the orbital area., Methods: An anthropomorphic head phantom was manufactured by submerging a dry human skull in silicon to mimic the soft tissue attenuation and scattering properties of the human head. The phantom was scanned on a ProMax 3D MAX CBCT scanner using 90 and 120 kV for four different field of view positions: standard; elevated; backwards tilted; and forward tilted. All CBCT images were subsequently converted into 3D models and geometrically compared with a "gold-standard" optical scan of the dry skull., Results: Mean absolute deviations of the 3D models ranged between 0.15 ± 0.11 mm and 0.56 ± 0.28 mm. The elevated imaging position in combination with 120 kV tube voltage resulted in an improved representation of the orbital walls in the resulting 3D model without compromising the accuracy., Conclusions: Head positioning during CBCT imaging can influence the accuracy of the resulting 3D model. The accuracy of such models may be improved by positioning the region of interest ( e.g. the orbital area) in the focal plane (Figure 2a) of the CBCT X-ray beam.

Introduction: This paper analyses and discusses the models and tools in the Finnish health and social care system to identify the individuals who might benefit from integrated multidisciplinary care., Description: The analysis and discussion of the paper is based on a study which mapped and studied the models and tools in practice or under development for identification in the Finnish health and social care organizations. The study used electric survey and structured interviews as research methods., Discussion: There are several different established models of identification in Finland and the experiences of using them are mainly positive. However, only every third of health and social care organizations in Finland have defined a common model or tool. The identification practices and criteria vary by region, municipality and/or organization. The identification is in general unsystematic and insufficient in practice that may inhibit the individuals to access the integrated care they might benefit from., Conclusions: Models and tools are needed for founding and identifying individuals who are outside the service system, those whose client-ship has just begun, and those who already access services. The identification of individuals for integrated multidisciplinary care and the assimilation and understanding of different identification models and tools requires the development of basic and further competence in the different fields of health and social care. Multidisciplinary collaboration requires shared concepts and positive attitudes on the development of integrated professional environments, identification models and services. It is therefore also a question of shared working culture., Competing Interests: The authors have no competing interest to declare., (Copyright: © 2022 The Author(s).)

Objective: The purpose of this study was to evaluate the impact of thyroid gland shielding on radiation doses in dental cone beam computed tomography (CBCT) with small and medium fields of view (FOVs)., Study Design: Six CBCT protocols were investigated by exposing an adult anthropomorphic male phantom head without and with thyroid shielding, using 4 small (4 × 5 cm) and 2 medium (10 × 6 cm) FOVs. Twenty metal oxide semiconductor field-effect transistor dosimeters were placed in the phantom head to measure absorbed doses and calculate equivalent doses at 11 sites. Effective doses were calculated based on the tissue weighting factors in International Commission on Radiological Protection Publication 103. The data were analyzed using the independent samples t test., Results: Thyroid gland shielding led to significant equivalent dose reductions in many tissues for all protocols. Equivalent dose reductions to the thyroid were significant in all 6 protocols (P ≤ .037). Significant reduction depended on the FOV and ranged between 24.5% and 42.6% for the thyroid gland and 4.9% and 34.5% for other tissues and organs. Effective doses were significantly lower in all protocols (P ≤ .016)., Conclusions: Thyroid gland shielding protects the thyroid gland and other organs and should be utilized with all CBCT examinations where feasible., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: To highlight the detail obtained on a Cone Beam Computed Tomography (CBCT) scan of the craniocervical junction and its usefulness to Chiropractors who specialize in the upper cervical spine. A review of the dose considerations to patients vs radiography in a chiropractic clinical setting and to review the effective radiation dose to the patient., Methods: A review of studies discussing cervical biomechanics, neurovascular structures, and abnormal radiographic findings, was discussed in relation to chiropractic clinical relevance. Further studies were evaluated demonstrating radiation dose to the patient from radiographs compared to CBCT., Results: Incidental and abnormal findings of the craniocervical junction were shown to have superior visualization with CBCT compared to radiography. The radiation dose to the patient for similar imaging protocols to the craniocervical junction and cervical spine was equal or less utilizing CBCT when compared to radiographs., Conclusions: The use of CBCT for visualization of the craniocervical junction and cervical spine in the chiropractic clinical setting allows for adjunctive visualization of the osseous structures which is germane to clinical protocol. Further with CBCT the effective dose to the patient is equal or less than similar imaging protocols utilizing radiographs to evaluate the craniocervical junction., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)

Mimicking natural structures allows the exploitation of proven design concepts for advanced material solutions. Here, our inspiration comes from the anisotropic closed cell structure of wood. The bubbles in our fiber reinforced foam are elongated using temperature dependent viscosity of methylcellulose and constricted drying. The oriented structures lead to high yield stress in the primary direction; 64 times larger than compared to the cross direction. The closed cells of the foam also result in excellent thermal insulation. The proposed novel foam manufacturing process is trivial to up-scale from the laboratory trial scale towards production volumes on industrial scales., (© 2021. The Author(s).)

Background: Although the COVID-19 pandemic has significantly boosted the implementation of digital services worldwide, it has become increasingly important to understand how these solutions are integrated into professionals' routine work. Professionals who are using the services are key influencers in the success of implementations. To ensure successful implementations, it is important to understand the multiprofessional perspective, especially because implementations are likely to increase even more., Objective: The aim of this study is to examine health and social care professionals' experiences of digital service implementations and to identify factors that support successful implementations and should be considered in the future to ensure that the services are integrated into professionals' routine work., Methods: A qualitative approach was used, in which 8 focus group interviews were conducted with 30 health and social care professionals from 4 different health centers in Finland. Data were analyzed using qualitative content analysis. The resulting categories were organized under the components of normalization process theory., Results: Our results suggested 14 practices that should be considered when implementing new digital services into routine work. To get professionals to understand and make sense of the new service, (1) the communication related to the implementation should be comprehensive and continuous and (2) the implementation process should be consistent. (3) A justification for the service being implemented should also be given. The best way to engage the professionals with the service is (4) to give them opportunities to influence and (5) to make sure that they have a positive attitude toward the service. To enact the new service into professionals' routine work, it is important that (6) the organization take a supportive approach by providing support from several easy and efficient sources. The professionals should also have (7) enough time to become familiar with the service, and they should have (8) enough know-how about the service. The training should be (9) targeted individually according to skills and work tasks, and (10) it should be diverse. The impact of the implementation on the professionals' work should be evaluated. The service (11) should be easy to use, and (12) usage monitoring should happen. An opportunity (13) to give feedback on the service should also be offered. Moreover, (14) the service should support professionals' work tasks., Conclusions: We introduce 14 practices for organizations and service providers on how to ensure sustainable implementation of new digital services and the smooth integration into routine work. It is important to pay more attention to comprehensive and continuing communication. Organizations should conduct a competence assessment before training in order to ensure proper alignment. Follow-ups to the implementation process should be performed to guarantee sustainability of the service. Our findings from a forerunner country of digitalization can be useful for countries that are beginning their service digitalization or further developing their digital services., (©Janna Nadav, Anu-Marja Kaihlanen, Sari Kujala, Elina Laukka, Pirjo Hilama, Juha Koivisto, Ilmo Keskimäki, Tarja Heponiemi. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 01.12.2021.)

Background and Objective: Over the past decade, convolutional neural networks (CNNs) have revolutionized the field of medical image segmentation. Prompted by the developments in computational resources and the availability of large datasets, a wide variety of different two-dimensional (2D) and three-dimensional (3D) CNN training strategies have been proposed. However, a systematic comparison of the impact of these strategies on the image segmentation performance is still lacking. Therefore, this study aimed to compare eight different CNN training strategies, namely 2D (axial, sagittal and coronal slices), 2.5D (3 and 5 adjacent slices), majority voting, randomly oriented 2D cross-sections and 3D patches., Methods: These eight strategies were used to train a U-Net and an MS-D network for the segmentation of simulated cone-beam computed tomography (CBCT) images comprising randomly-placed non-overlapping cylinders and experimental CBCT images of anthropomorphic phantom heads. The resulting segmentation performances were quantitatively compared by calculating Dice similarity coefficients. In addition, all segmented and gold standard experimental CBCT images were converted into virtual 3D models and compared using orientation-based surface comparisons., Results: The CNN training strategy that generally resulted in the best performances on both simulated and experimental CBCT images was majority voting. When employing 2D training strategies, the segmentation performance can be optimized by training on image slices that are perpendicular to the predominant orientation of the anatomical structure of interest. Such spatial features should be taken into account when choosing or developing novel CNN training strategies for medical image segmentation., Conclusions: The results of this study will help clinicians and engineers to choose the most-suited CNN training strategy for CBCT image segmentation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier B.V.)

High cone-angle artifacts (HCAAs) appear frequently in circular cone-beam computed tomography (CBCT) images and can heavily affect diagnosis and treatment planning. To reduce HCAAs in CBCT scans, we propose a novel deep learning approach that reduces the three-dimensional (3D) nature of HCAAs to two-dimensional (2D) problems in an efficient way. Specifically, we exploit the relationship between HCAAs and the rotational scanning geometry by training a convolutional neural network (CNN) using image slices that were radially sampled from CBCT scans. We evaluated this novel approach using a dataset of input CBCT scans affected by HCAAs and high-quality artifact-free target CBCT scans. Two different CNN architectures were employed, namely U-Net and a mixed-scale dense CNN (MS-D Net). The artifact reduction performance of the proposed approach was compared to that of a Cartesian slice-based artifact reduction deep learning approach in which a CNN was trained to remove the HCAAs from Cartesian slices. In addition, all processed CBCT scans were segmented to investigate the impact of HCAAs reduction on the quality of CBCT image segmentation. We demonstrate that the proposed deep learning approach with geometry-aware dimension reduction greatly reduces HCAAs in CBCT scans and outperforms the Cartesian slice-based deep learning approach. Moreover, the proposed artifact reduction approach markedly improves the accuracy of the subsequent segmentation task compared to the Cartesian slice-based workflow., (© 2021 Institute of Physics and Engineering in Medicine.)

The aim of the study was to estimate and to compare effective doses in the elbow region resulting from four different x-ray imaging modalities. Absorbed organ doses were measured using 11 metal oxide field effect transistor (MOSFET) dosimeters that were placed in a custom-made anthropomorphic elbow RANDO phantom. Examinations were performed using Shimadzu FH-21 HR radiography device, Siemens Sensation Open 24-slice MSCT-device, NewTom 5G CBCT device, and Planmed Verity CBCT device, and the effective doses were calculated according to ICRP 103 recommendations. The effective dose for the conventional radiographic device was 1.5 µSv. The effective dose for the NewTom 5G CBCT ranged between 2.0 and 6.7 µSv, for the Planmed Verity CBCT device 2.6 µSv and for the Siemens Sensation MSCT device 37.4 µSv. Compared with conventional 2D radiography, this study demonstrated a 1.4-4.6 fold increase in effective dose for CBCT and 25-fold dose for standard MSCT protocols. When compared with 3D CBCT protocols, the study showed a 6-19 fold increase in effective dose using a standard MSCT protocol. CBCT devices offer a feasible low-dose alternative for elbow 3D imaging when compared to MSCT., (© 2021 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.)

Unicellular Chlamydomonas reinhardtii micro-algae cells were inserted into a quasi-2D Hele-Shaw chamber filled with saponin foam. The movement of the algae along the bubble borders was then manipulated and tracked. These self-propelled particles generate flow and stresses in their surrounding matter. In addition, the algae possess the capability of exerting forces that alter bubble boundaries while maintaining an imminent phototactic movement. We find that by controlling the gas fraction of the foam we can change the interaction of the algae and bubbles. Specifically, our data expose three distinct swimming regimes for the algae with respect to the level of confinement due to the Plateau border cross-section: unlimited bulk, transition, and overdamped regimes. At the transition regime we find the speed of the algae to be modeled by a simple force balance equation emerging from the shear inside the Plateau border. Thus, we have shown that it is possible to create an algae-friendly foam while controlling the algae motion. This opens doors to multiple applications where the flow of nutrients, oxygen and recirculation of living organisms is essential.

In rheological terms, foams are time independent yield stress fluids, displaying properties of both solid and liquid materials. Here we measure the propagation of a 2D dry foam in a radially symmetric Hele-Shaw cell forcing local yielding. The yield rate is manipulated by mechanical vibration with frequencies from 0 to 150 Hz. The flow speed is then extracted from the video stream and analyzed using digital image correlation software. The data are modeled analytically by a Guzman-Arrhenius type of energy landscape where the local yielding of foam correlates with the number of oscillations, i.e. attempts to cross the energy barrier. The model is confirmed in an auxiliary experiment where the vibrated foam stays in its flowing state at the same small driving pressures, where the flow of the unvibrated foam ceases. We conclude that the yield stress behaviour of foams under an external perturbation can be summarized using a simple energy landscape model. The vibration affects the films causing the stress to occasionally and locally exceed the yield threshold. This, thus, prevents the foam from jamming as in a static configuration even when the global driving is below the yield point of the foam.

We study the compression of low-weight foam-formed materials made out of wood fibers. Initially the stress-strain behavior follows mean-field like response, related to the buckling of fiber segments as dictated by the random three-dimensional geometry. Our Acoustic Emission (AE) measurements correlate with the predicted number of segment bucklings for increasing strain. However, the experiments reveal a transition to collective phenomena as the strain increases sufficiently. This is also seen in the gradual failure of the theory to account for the stress-strain curves. The collective avalanches exhibit scale-free features both as regards the AE energy distribution and the AE waiting time distributions with both exponents having values close to 2. In cyclic compression tests, significant increases in the accumulated acoustic energy are found only when the compression exceeds the displacement of the previous cycle, which further confirms other sources of acoustic events than fiber bending.

Here, we follow the stable propagation of a roughening crack using simultaneously Digital Image Correlation and Infra-Red imaging. In a quasi-two-dimensional paper sample, the crack tip and ahead of that the fracture process zone follow the slowly, diffusively moving "hot spot" ahead of the tip. This also holds when the crack starts to roughen during propagation. The well-established intermittency of the crack advancement and the roughening of the crack in paper are thus subject to the dissipation and decohesion in the hot spot zone. They are therefore not only a result of the depinning of the crack in a heterogeneous material.

Objectives:: The primary aim was to evaluate the effective dose for a full size panoramic image and nine different panoramic protocols using collimation. The secondary aim was to estimate possible reduction of effective dose in clinical situations., Methods: Effective dose, according to International Commission on Radiological Protection 2007 was determined for a full size panoramic image and nine different panoramic protocols applying collimation on an anthropomorphic Rando phantom, using metal-oxide semiconductor field-effect transistor dosemeters. The collimation protocols were chosen based on common diagnostic questions. 10 exposures were made for each protocol using a Planmeca ProMax® 2D (Helsinki, Finland). The mean effective doses were calculated according to clinical default exposure settings and compared for all protocols. A retrospective analysis of 252 referrals to a specialist clinic in dentomaxillofacial radiology assessed usability and dose reduction applying nine different collimation protocols, based on possible collimation of panoramic images. Dose reduction was calculated applying collimation feature in comparison to constant use of full size panoramic imaging. Referrals were categorized according to indication for radiographic examination., Results:: Effective dose of a full size panoramic radiograph was 17.6 µSv at 8 mA and 66 kV. The dose reduction for the collimated images compared to a full size panoramic radiograph ranged from 4.5 to 86.9%. Potential total dose reduction in the studied sample was 35% if collimation feature had been applied. In four out of five of the referrals, collimation was possible and in 61% of the referrals the indication for radiographic examination was restricted to the dental alveolar region, reducing the dose by 40.3% compared with a full size panoramic image., Conclusions:: Since the effective dose may be reduced without losing diagnostic information in the area of interest, collimation feature of panoramic imaging should be routinely applied when the diagnostic task allows.

Aim of the Study: The accuracy of additive manufactured medical constructs is limited by errors introduced during image segmentation. The aim of this study was to review the existing literature on different image segmentation methods used in medical additive manufacturing., Methods: Thirty-two publications that reported on the accuracy of bone segmentation based on computed tomography images were identified using PubMed, ScienceDirect, Scopus, and Google Scholar. The advantages and disadvantages of the different segmentation methods used in these studies were evaluated and reported accuracies were compared., Results: The spread between the reported accuracies was large (0.04 mm - 1.9 mm). Global thresholding was the most commonly used segmentation method with accuracies under 0.6 mm. The disadvantage of this method is the extensive manual post-processing required. Advanced thresholding methods could improve the accuracy to under 0.38 mm. However, such methods are currently not included in commercial software packages. Statistical shape model methods resulted in accuracies from 0.25 mm to 1.9 mm but are only suitable for anatomical structures with moderate anatomical variations., Conclusions: Thresholding remains the most widely used segmentation method in medical additive manufacturing. To improve the accuracy and reduce the costs of patient-specific additive manufactured constructs, more advanced segmentation methods are required., (Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.)

Objectives: To assess the impact of supine, prone and oblique patient imaging positions on the image quality, contrast-to-noise ratio (CNR) and figure of merit (FOM) value in the maxillofacial region using a CBCT scanner. Furthermore, the CBCT supine images were compared with supine multislice CT (MSCT) images., Methods: One fresh frozen cadaver head was scanned in prone, supine and oblique imaging positions using a mobile CBCT scanner. MSCT images of the head were acquired in a supine position. Two radiologists graded the CBCT and MSCT images at ten different anatomical sites according to their image quality using a six-point scale. The CNR and FOM values were calculated at two different anatomical sites on the CBCT and MSCT images., Results: The best image quality was achieved in the prone imaging position for sinus, mandible and maxilla, followed by the supine and oblique imaging positions. 12-mA prone images presented high delineation scores for all anatomical landmarks, except for the ear region (carotid canal), which presented adequate to poor delineation scores for all studied head positions and exposure parameters. The MSCT scanner offered similar image qualities to the 7.5-mA supine images acquired using the mobile CBCT scanner. The prone imaging position offered the best CNR and FOM values on the mobile CBCT scanner., Conclusions: Head positioning has an impact on CBCT image quality. The best CBCT image quality can be achieved using the prone and supine imaging positions. The oblique imaging position offers inadequate image quality except in the sinus region.

Purpose: Medical additive manufacturing requires standard tessellation language (STL) models. Such models are commonly derived from computed tomography (CT) images using thresholding. Threshold selection can be performed manually or automatically. The aim of this study was to assess the impact of manual and default threshold selection on the reliability and accuracy of skull STL models using different CT technologies., Method: One female and one male human cadaver head were imaged using multi-detector row CT, dual-energy CT, and two cone-beam CT scanners. Four medical engineers manually thresholded the bony structures on all CT images. The lowest and highest selected mean threshold values and the default threshold value were used to generate skull STL models. Geometric variations between all manually thresholded STL models were calculated. Furthermore, in order to calculate the accuracy of the manually and default thresholded STL models, all STL models were superimposed on an optical scan of the dry female and male skulls ("gold standard")., Results: The intra- and inter-observer variability of the manual threshold selection was good (intra-class correlation coefficients >0.9). All engineers selected grey values closer to soft tissue to compensate for bone voids. Geometric variations between the manually thresholded STL models were 0.13 mm (multi-detector row CT), 0.59 mm (dual-energy CT), and 0.55 mm (cone-beam CT). All STL models demonstrated inaccuracies ranging from -0.8 to +1.1 mm (multi-detector row CT), -0.7 to +2.0 mm (dual-energy CT), and -2.3 to +4.8 mm (cone-beam CT)., Conclusions: This study demonstrates that manual threshold selection results in better STL models than default thresholding. The use of dual-energy CT and cone-beam CT technology in its present form does not deliver reliable or accurate STL models for medical additive manufacturing. New approaches are required that are based on pattern recognition and machine learning algorithms.