Aiming for [18F]FDG-PET acquisition time reduction in clinical practice for neurological patients.

PURPOSE: Positron emission tomography (PET) imaging with [18F]FDG provides valuable information regarding the underlying pathological processes in neurodegenerative disorders. PET imaging for these populations should be as short as possible to limit head movements and improve comfort. This study aimed to validate an optimized [18F]FDG-PET image reconstruction protocol aiming to reduce acquisition time while maintaining adequate quantification accuracy and image quality. METHODS: A time-reduced reconstruction protocol (5 min) was evaluated in [18F]FDG-PET retrospective data from healthy individuals and Alzheimer's disease (AD) patients. Standard (8 min) and time-reduced protocols were compared by means of image quality and quantification accuracy metrics, as well as standardized uptake value ratio (SUVR) and Z-scores (pons was used as reference). Images were randomly and blindly presented to experienced physicians and scored in terms of image quality. RESULTS: No differences between protocols were identified during the visual assessment. Small differences (p < 0.01) in the pons SUVR were observed between the standard and time-reduced protocols for healthy individuals (-0.002 ±â€¯0.011) and AD patients (-0.007 ±â€¯0.013). Likewise, incorporating the PSF correction in the reconstruction algorithm resulted in small differences (p < 0.01) in SUVR between protocols (healthy individuals: -0.003 ±â€¯0.011; AD patients: -0.007 ±â€¯0.014). CONCLUSION: Quality metrics were similar between time-reduced and standard protocols. In the visual assessment of the images, the physicians did not consider the use of PSF adequate, as it degraded the quality image. Shortening the acquisition time is possible by optimizing the image reconstruction parameters while maintaining adequate quantification accuracy and image quality.

A new model for classification of medical CT images using CNN: a COVID-19 case study.

SARS-CoV-2 is the causative agent of COVID-19 and leaves characteristic impressions on chest Computed Tomography (CT) images in infected patients and this analysis is performed by radiologists through visual reading of lung images, and failures may occur. In this article, we propose a classification model, called Wavelet Convolutional Neural Network (WCNN) that aims to improve the differentiation of images of patients with COVID-19 from images of patients with other lung infections. The WCNN model was based on a Convolutional Neural Network (CNN) and wavelet transform. The model proposes a new input layer added to the neural network, which was called Wave layer. The hyperparameters values were defined by ablation tests. WCNN was applied to chest CT images to images from two internal and one external repositories. For all repositories, the average results of Accuracy (ACC), Sensitivity (Sen) and Specificity (Sp) were calculated. Subsequently, the average results of the repositories were consolidated, and the final values were ACC = 0.9819, Sen = 0.9783 and Sp = 0.98. The WCNN model uses a new Wave input layer, which standardizes the network input, without using data augmentation, resizing and segmentation techniques, maintaining the integrity of the tomographic image analysis. Thus, applications developed based on WCNN have the potential to assist radiologists with a second opinion in the analysis.1.

Perception of Orthopedics Surgeons about the Risks of Radiation Exposure in Fluoroscopy.

Objective The present study aims to understand the perceptions of orthopedists and traumatologists regarding the risk of exposure to ionizing radiation in fluoroscopy procedures. Methods An objective, structured, self-administered questionnaire with sociodemographic, professional, and occupational variables was developed, available through an invitation sent to orthopedist physicians whose contacts were made publicly available. Results A total of 141 questionnaires were answered and analyzed. Most respondents (99%) use fluoroscopy in their surgeries, and only 34.8% of the participants feel safe with the use of the equipment. It was observed that the knowledge about ionizing radiation is inadequate, because 22.6% of the participants are unaware of the type of radiation emitted in fluoroscopy and its biological effects. In addition, 52% of the participants did not know or do not understand the principles of radiological protection and their relationship with surgical practices. Conclusion We concluded that the radiological protection of most orthopedists in surgical procedures is inadequate, and initial and continued training programs of professionals are necessary, bringing health benefits to orthopedists and their patients.

Perception of Orthopedics Surgeons about the Risks of Radiation Exposure in Fluoroscopy / Percepção de cirurgiões ortopédicos sobre os riscos da exposição à radiação na fluoroscopia

Abstract Objective The present study aims to understand the perceptions of orthopedists and traumatologists regarding the risk of exposure to ionizing radiation in fluoroscopy procedures. Methods An objective, structured, self-administered questionnaire with sociodemographic, professional, and occupational variables was developed, available through an invitation sent to orthopedist physicians whose contacts were made publicly available. Results A total of 141 questionnaires were answered and analyzed. Most respondents (99%) use fluoroscopy in their surgeries, and only 34.8% of the participants feel safe with the use of the equipment. It was observed that the knowledge about ionizing radiation is inadequate, because 22.6% of the participants are unaware of the type of radiation emitted in fluoroscopy and its biological effects. In addition, 52% of the participants did not know or do not understand the principles of radiological protection and their relationship with surgical practices. Conclusion We concluded that the radiological protection of most orthopedists in surgical procedures is inadequate, and initial and continued training programs of professionals are necessary, bringing health benefits to orthopedists and their patients.

Resumo Objetivo Este estudo visa compreender as percepções dos médicos ortopedistas e traumatologistas em relação ao risco da exposição à radiação ionizante nos procedimentos de fluoroscopia. Métodos Desenvolveu-se um questionário objetivo, estruturado, autoaplicável e com variáveis sociodemográficas, profissionais e ocupacionais, disponibilizado através de convite enviado a médicos ortopedistas cujos contatos estavam disponibilizados publicamente. Resultados Foram respondidos e analisados 141 questionários. A maioria dos respondentes (99%) utilizam a fluoroscopia em suas cirurgias, e apenas 34,8% dos participantes se sentem seguros com o uso do equipamento. Observou-se que o conhecimento sobre radiação ionizante é inadequado, pois 22,6% dos respondentes desconhecem o tipo de radiação emitida na fluoroscopia e seus efeitos biológicos. Além disso, 52% dos respondentes não conhecem ou não compreendem os princípios de proteção radiológica e suas relações com as práticas cirúrgicas. Conclusão Conclui-se que a proteção radiológica da maioria dos ortopedistas nos procedimentos cirúrgicos é inadequada e são necessários programas de formação inicial e continuada dos profissionais, trazendo benefícios para a saúde dos ortopedistas e de seus pacientes.

Women in Medical Physics and Biomedical Engineering: past, present and future.

Women in Medical Physics and Biomedical Engineering (WiMPBME) is a Task Group established in 2014 under the International Union of Physical and Engineering Scientists in Medicine (IUPESM). The group's main role is to identify, develop, implement, and coordinate various tasks and projects related to women's needs and roles in medical physics and biomedical engineering around the world. The current paper summarizes the past, present and future goals and activities undertaken or planned by the Task group in order to motivate, nurture and support women in medical physics and biomedical engineering throughout their professional careers. In addition, the article includes the historical pathway followed by various women's groups and subcommittees from 2004 up to the present day and depicts future aims to further these professions in a gender-balanced manner.

Parametric Imaging of [11C]Flumazenil Binding in the Rat Brain.

PURPOSE: This study evaluates the performance of several parametric methods for assessing [11C]flumazenil binding distribution in the rat brain. PROCEDURES: Dynamic (60 min) positron emission tomography data with metabolite-corrected plasma input function were retrospectively analyzed (male Wistar rats, n = 10). Distribution volume (V T) images were generated from basis function method (BFM), Logan graphical analysis (Logan), and spectral analysis (SA). Using the pons as pseudo-reference tissue, binding potential (BP ND and DVR-1) images were obtained from receptor parametric imaging algorithms (RPM and SRTM2) and reference Logan (RLogan). Standardized uptake value images (SUV and SUVR) were also computed for different intervals post-injection. Next, regional averages were extracted from the parametric images, using pre-defined volumes of interest, which were also applied to the regional time-activity curves from the dynamic data. Parametric data were compared to their regional counterparts and to two-tissue compartment model (2TCM)-based values (previously defined as the model of choice for rats). Parameter agreement was assessed by linear regression analysis and Bland-Altman plots. RESULTS: All parametric methods strongly correlated to their regional counterparts (R 2 > 0.97) and to the 2TCM values (R 2 ≥ 0.95). SA and RLogan underestimated V T and BP ND (slope of 0.93 and 0.86, respectively), while SUVR-1 overestimated BP ND (slope higher than 1.07 for all intervals). While BFM and SRTM2 had the smallest bias to 2TCM values (0.05 for both), ratio Bland-Altman plots showed Logan and RLogan displayed relative errors which were comparable between different regions, in contrast with the other methods. Although SUV consistently underestimated V T, the bias in this method was also constant across regions. CONCLUSIONS: All parametric methods performed well for the analysis of [11C]flumazenil distribution and binding in the rat brain. However, Logan and RLogan slightly outperformed the other methods in terms of precision, providing robust parameter estimation and constant bias. Yet, other methods can be of interest, because they can provide tissue perfusion (i.e., K 1 with BFM and SA), relative flow (i.e., R 1 with RPM and SRTM2), and model order (SA) images.

Primary progressive aphasia patients evaluated using diffusion tensor imaging and voxel based volumetry-preliminary results.

UNLABELLED: There are individuals who have a progressive language deficit without presenting cognitive deficits in other areas. One of the diseases related to this presentation is primary progressive aphasia (PPA). OBJECTIVE: Identify by means of diffusion tensor imaging (DTI) and measurements of cortical volume, brain areas that lead to dysphasia when presenting signs of impaired connectivity or reduced volume. METHOD: Four patients with PPA were evaluated using DTI, and measurements of cortical volumes in temporal areas. These patients were compared with two normal volunteers. RESULTS: There is a trend to a difference in the number and volume of related fibers between control group and patients with PPA. Comparing cortical volumes in temporal areas between groups yielded a trend to a smaller volume in PPA patients. CONCLUSION: Patients with PPA have a trend to impairment in cortical and subcortical levels regarding relevant areas.

Primary progressive aphasia patients evaluated using diffusion tensor imaging and voxel based volumetry-preliminary results / Avaliação de pacientes com afasia primária progressiva com imagem tensor de difusão e volumetria baseada em voxels

There are individuals who have a progressive language deficit without presenting cognitive deficits in other areas. One of the diseases related to this presentation is primary progressive aphasia (PPA). OBJECTIVE: Identify by means of diffusion tensor imaging (DTI) and measurements of cortical volume, brain areas that lead to dysphasia when presenting signs of impaired connectivity or reduced volume. METHOD: Four patients with PPA were evaluated using DTI, and measurements of cortical volumes in temporal areas. These patients were compared with two normal volunteers. RESULTS: There is a trend to a difference in the number and volume of related fibers between control group and patients with PPA. Comparing cortical volumes in temporal areas between groups yielded a trend to a smaller volume in PPA patients. CONCLUSION: Patients with PPA have a trend to impairment in cortical and subcortical levels regarding relevant areas.

Existem indivíduos que apresentam deterioração progressiva da linguagem sem apresentar déficits em outros domínios cognitivos; estes pacientes em geral apresentam afasia primária progressiva (APP). OBJETIVO: Identificar, pela imagenologia, áreas cerebrais que quando sofrem atrofia, ou quando seu sistema de conexões apresenta alterações, levam a disfasia. MÉTODO: Foram avaliados quatro pacientes com APP, utilizando-se ressonância magnética com as técnicas de imagem por tensores da difusão (DTI) e medida do volume cortical em áreas de interesse previamente definidas. Estes pacientes foram comparados com um grupo controle constituído por dois voluntários. RESULTADOS: Redução da média dos volumes dos giros temporais esquerdos no grupo de pacientes, em relação ao grupo controle, e alterações quanto ao volume e número de fibras nos tratos correspondentes. CONCLUSÃO: Pacientes com APP têm tendência a apresentar danos tanto ao nível cortical quanto subcortical.

Ambiente colaborativo para formação de pessoal em medicina nuclear / Collaborative environment for nuclear medicine training

OBJETIVO: Validar a proposta do desenvolvimento de um ambiente colaborativo virtual para formação de pessoal em medicina nuclear. MATERIAIS E MÉTODOS: No desenvolvimento inicial do ambiente foram levantadas as premissas, restrições e funcionalidades que deveriam ser oferecidas aos profissionais da área. O protótipo foi desenvolvido no ambiente Moodle, incluindo funcionalidades de armazenamento de dados e interação. Um estudo piloto de interação no ambiente foi realizado com uma amostra de profissionais especialistas em medicina nuclear. Análises quantitativas e de conteúdo foram realizadas a partir de um questionário semiestruturado de opinião dos usuários. RESULTADOS: A proposta do ambiente colaborativo foi validada por uma comunidade de profissionais que atuam nesta área e considerada relevante visando a auxiliar na formação de pessoal. Sugestões de melhorias e novas funcionalidades foram indicadas. Observou-se a necessidade de estabelecer um programa de formação dos moderadores no ambiente, visto que são necessárias características de interação distintas do ensino presencial. CONCLUSÃO: O ambiente colaborativo poderá permitir a troca de experiências e a discussão de casos entre profissionais localizados em instituições de diferentes regiões do País, possibilitando uma aproximação e colaboração entre esses profissionais. Assim, o ambiente pode contribuir para formação inicial e continuada de profissionais que atuam em medicina nuclear.

OBJECTIVE: To validate the proposal for development of a virtual collaborative environment for training of nuclear medicine personnel. MATERIALS AND METHODS: Organizational assumptions, constraints and functionalities that should be offered to the professionals in this field were raised early in the development of the environment. The prototype was developed in the Moodle environment, including data storage and interaction functionalities. A pilot interaction study was developed with a sample of specialists in nuclear medicine. Users' opinions collected by means of semi-structured questionnaire were submitted to quantitative and content analysis. RESULTS: The proposal of a collaborative environment was validated by a community of nuclear medicine professionals and considered as an aid in the training in this field. Suggestions for improvements and new functionalities were made. There is a need to establish a program for education of moderators specifically for this environment, considering the different interaction characteristics as the online and conventional teaching methods are compared. CONCLUSION: The collaborative environment will allow the exchange of experiences and case discussions among professionals from institutions located in different regions all over the country, enhancing the collaboration among them. Thus, the environment can contribute in the early and continued education of nuclear medicine professionals.

Estimativa da idade óssea através da análise de imagens digitais / Estimative bone age by digital images analysis

Foi desenvolvido um algorítmo que permite a estimativa da idade óssea através da análise de imagens radiológicas digitais. As regiões de interesse na imagem são as falanges e os metacarpos, que são realçadas e, através da aplicação de filtros espaciais e morfológicos, são segmentos para extração de parâmetros geométricos, tais como as medidas de perímetro, altura e área, da porção distal até a proximal. A quantificação destes parâmetros permite a comparação entre a idade cronológica e óssea, através de tabelas de crescimento padrão.