Are we using appropriate segmentation metrics? Identifying correlates of human expert perception for CNN training beyond rolling the DICE coefficient

In this study, we explore quantitative correlates of qualitative human expert perception. We discover that current quality metrics and loss functions, considered for biomedical image segmentation tasks, correlate moderately with segmentation quality assessment by experts, especially for small yet clinically relevant structures, such as the enhancing tumor in brain glioma. We propose a method employing classical statistics and experimental psychology to create complementary compound loss functions for modern deep learning methods, towards achieving a better fit with human quality assessment. When training a CNN for delineating adult brain tumor in MR images, all four proposed loss candidates outperform the established baselines on the clinically important and hardest to segment enhancing tumor label, while maintaining performance for other label channels

Are we using appropriate segmentation metrics? Identifying correlates of human expert perception for CNN training beyond rolling the DICE coefficient

In this study, we explore quantitative correlates of qualitative human expert perception. We discover that current quality metrics and loss functions, considered for biomedical image segmentation tasks, correlate moderately with segmentation quality assessment by experts, especially for small yet clinically relevant structures, such as the enhancing tumor in brain glioma. We propose a method employing classical statistics and experimental psychology to create complementary compound loss functions for modern deep learning methods, towards achieving a better fit with human quality assessment. When training a CNN for delineating adult brain tumor in MR images, all four proposed loss candidates outperform the established baselines on the clinically important and hardest to segment enhancing tumor label, while maintaining performance for other label channels

Whole-body imaging of the musculoskeletal system: the value of MR imaging

In clinical practice various modalities are used for whole-body imaging of the musculoskeletal system, including radiography, bone scintigraphy, computed tomography, magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT). Multislice CT is far more sensitive than radiographs in the assessment of trabecular and cortical bone destruction and allows for evaluation of fracture risk. The introduction of combined PET-CT scanners has markedly increased diagnostic accuracy for the detection of skeletal metastases compared with PET alone. The unique soft-tissue contrast of MRI enables for precise assessment of bone marrow infiltration and adjacent soft tissue structures so that alterations within the bone marrow may be detected before osseous destruction becomes apparent in CT or metabolic changes occur on bone scintigraphy or PET scan. Improvements in hard- and software, including parallel image acquisition acceleration, have made high resolution whole-body MRI clinically feasible. Whole-body MRI has successfully been applied for bone marrow screening of metastasis and systemic primary bone malignancies, like multiple myeloma. Furthermore, it has recently been proposed for the assessment of systemic bone diseases predisposing for malignancy (e.g., multiple cartilaginous exostoses) and muscle disease (e.g., muscle dystrophy). The following article gives an overview on state-of-the-art whole-body imaging of the musculoskeletal system and highlights present and potential future applications, especially in the field of whole-body MRI

Antonimias institucionales: militancia y burocratización en el ministerio de comunas de Venezuela

En este artículo exploro los diferentes modos en que las y los funcionarios(as) del Ministerio de Poder Popular para las Comunas y Movimientos Sociales (MPCyMS) se construyen como agentes políticos en base de un año de trabajo de investigación etnográfica que realicé allí entre 2017 y 2018. Partiendo de una caracterización clasista de la burocracia venezolana y el MPCyMS en particular, examino las concepciones contrastantes de compromiso político que se elaboran en el espacio institucional – orientada hacia la defensa del Gobierno Bolivariano y/o el fortalecimiento del poder popular –, basándose en la literatura sobre la militancia en el Estado. Luego, analizo las antonimias del concepto de burocratismo manejado por las y los funcionarios(as) según sus horizontes militantes. A partir de una corriente más crítica, desarrollo una categoría de burocratización para comprender la manera en que el objetivo político del Ministerio de construir el Estado comunal se subsume por la lógica técnocrata-electoralista propia del petro-Estado venezolano, lo cual provoca conflictos intraburocráticos.Fil: Koerner, Lucas Maximilian. Instituto para Estudios Avanzados (IDEA)

Antonimias institucionales: militancia y burocratización en el ministerio de comunas de Venezuela

En este artículo exploro los diferentes modos en que las y los funcionarios(as) del Ministerio de Poder Popular para las Comunas y Movimientos Sociales (MPCyMS) se construyen como agentes políticos en base de un año de trabajo de investigación etnográfica que realicé allí entre 2017 y 2018. Partiendo de una caracterización clasista de la burocracia venezolana y el MPCyMS en particular, examino las concepciones contrastantes de compromiso político que se elaboran en el espacio institucional – orientada hacia la defensa del Gobierno Bolivariano y/o el fortalecimiento del poder popular –, basándose en la literatura sobre la militancia en el Estado. Luego, analizo las antonimias del concepto de burocratismo manejado por las y los funcionarios(as) según sus horizontes militantes. A partir de una corriente más crítica, desarrollo una categoría de burocratización para comprender la manera en que el objetivo político del Ministerio de construir el Estado comunal se subsume por la lógica técnocrata-electoralista propia del petro-Estado venezolano, lo cual provoca conflictos intraburocráticos

AOSpine subaxial cervical spine injury classification system

Purpose: This project describes a morphology-based subaxial cervical spine traumatic injury classification system. Using the same approach as the thoracolumbar system, the goal was to develop a comprehensive yet simple classification system with high intra- and interobserver reliability to be used for clinical and research purposes. Methods: A subaxial cervical spine injury classification system was developed using a consensus process among clinical experts. All investigators were required to successfully grade 10 cases to demonstrate comprehension of the system before grading 30 additional cases on two occasions, 1 month apart. Kappa coefficients (κ) were calculated for intraobserver and interobserver reliability. Results: The classification system is based on three injury morphology types similar to the TL system: compression injuries (A), tension band injuries (B), and translational injuries (C), with additional descriptions for facet injuries, as well as patient-specific modifiers and neurologic status. Intraobserver and interobserver reliability was substantial for all injury subtypes (κ = 0.75 and 0.64, respectively). Conclusions: The AOSpine subaxial cervical spine injury classification system demonstrated substantial reliability in this initial assessment, and could be a valuable tool for communication, patient care and for research purposes

AOSpine subaxial cervical spine injury classification system

Purpose: This project describes a morphology-based subaxial cervical spine traumatic injury classification system. Using the same approach as the thoracolumbar system, the goal was to develop a comprehensive yet simple classification system with high intra- and interobserver reliability to be used for clinical and research purposes. Methods: A subaxial cervical spine injury classification system was developed using a consensus process among clinical experts. All investigators were required to successfully grade 10 cases to demonstrate comprehension of the system before grading 30 additional cases on two occasions, 1 month apart. Kappa coefficients (κ) were calculated for intraobserver and interobserver reliability. Results: The classification system is based on three injury morphology types similar to the TL system: compression injuries (A), tension band injuries (B), and translational injuries (C), with additional descriptions for facet injuries, as well as patient-specific modifiers and neurologic status. Intraobserver and interobserver reliability was substantial for all injury subtypes (κ = 0.75 and 0.64, respectively). Conclusions: The AOSpine subaxial cervical spine injury classification system demonstrated substantial reliability in this initial assessment, and could be a valuable tool for communication, patient care and for research purposes