Fast pseudo-CT synthesis from MRI T1-weighted images using a patch-based approach

MRI-based bone segmentation is a challenging task because bone tissue and air both present low signal intensity on MR images, making it difficult to accurately delimit the bone boundaries. However, estimating bone from MRI images may allow decreasing patient ionization by removing the need of patient-specific CT acquisition in several applications. In this work, we propose a fast GPU-based pseudo-CT generation from a patient-specific MRI T1-weighted image using a group-wise patch-based approach and a limited MRI and CT atlas dictionary. For every voxel in the input MR image, we compute the similarity of the patch containing that voxel with the patches of all MR images in the database, which lie in a certain anatomical neighborhood. The pseudo-CT is obtained as a local weighted linear combination of the CT values of the corresponding patches. The algorithm was implemented in a GPU. The use of patch-based techniques allows a fast and accurate estimation of the pseudo-CT from MR T1-weighted images, with a similar accuracy as the patient-specific CT. The experimental normalized cross correlation reaches 0.9324±0.0048 for an atlas with 10 datasets. The high NCC values indicate how our method can accurately approximate the patient-specific CT. The GPU implementation led to a substantial decrease in computational time making the approach suitable for real applications

Magnetic Resonance-Based Attenuation Correction and Scatter Correction in Neurological Positron Emission Tomography/Magnetic Resonance Imaging—Current Status With Emerging Applications

In this review, we will summarize the past and current state-of-the-art developments in attenuation and scatter correction approaches for hybrid positron emission tomography (PET) and magnetic resonance (MR) imaging. The current status of the methodological advances for producing accurate attenuation and scatter corrections on PET/MR systems are described, in addition to emerging clinical and research applications. Future prospects and potential applications that benefit from accurate data corrections to improve the quantitative accuracy and clinical applicability of PET/MR are also discussed. Novel clinical and research applications where improved attenuation and scatter correction methods are beneficial are highlighted

Descripción de las saponinas en quinua (Chenopodium quinoa willd) en relación con el suelo y el clima: Una revisión

Increasingly, the production of quinoa (Chenopodium quinoa Willd) in different regions of the world becomes more important, due to the fact that it has been sought to position the crop as an alternative to food security. However, this plant has metabolites such as tannins and saponins, which are chemical substances that serve as protective barriers to biotic and abiotic factors. In the case of saponins, 31 chemical structures are recognized, present in leaves, stems, panicles, husk and seeds of different species and genotypes. In this regard, this review seeks to describe general characteristics of the saponins present in quinoa and its relations with soil and climate. Finding that the edaphoclimatics characteristic of each place as well as the genetic characteristics of each variety are determinants in the content of saponin compounds stimulated mainly by water and saline stress.Cada vez, toma mayor importancia la producción de la quinua (Chenopodium quinoa Willd) en diferentes regiones del mundo, debido a que se ha buscado posicionar el cultivo como una alternativa de seguridad alimentaria. Sin embargo, esta planta presenta metabolitos como taninos y saponinas que son sustancias químicas que sirven de barreras de protección a factores bióticos y abióticos. En el caso de las saponinas, se reconocen 31 estructuras químicas, presentes en hojas, tallos, panojas, cascarilla y semillas de diferentes especies y genotipos. Al respecto, esta revisión busca describir características generales de las saponinas presentes en la quinua y su relación con el suelo y el clima. Encontrando que las edafoclimáticas propias de cada lugar, así como las características genéticas de cada variedad son determinantes en el contenido de compuestos saponínicos, estimulados principalmente por estrés de tipo hídrico y salino

La imagen y la narrativa como herramientas para el abordaje psicosocial en escenarios de violencia en los municipios de Abrego, Labateca norte de Santander y San Gil Santander

En este documento plasmamos los análisis de dos casos propuestos por la “guía de actividades del diplomado de profundización acompañamiento psicosocial en escenarios de violencia”, donde se expone el caso de camilo un joven que huye a la violencia del Quibdó, desde pequeño ha estado en escenarios violentos, ha visto la maldad , el dolor, el desarraigo de sus raíces y familiares, trato de ser un líder colocando su voz por los demás pero fue callado, muchas veces fue amenazado y en algunas casi es reclutado por los grupos Almargen de la ley, además fue víctimas de las malas acusaciones por parte de los entes de justicia del estado. Para cerrar el caso se articulan unas preguntas reflexivas, circulares y estratégicas. Luego pasamos a realizar el análisis del caso “Peñas coloradas” que al igual es un entorno de violencia, incluyendo a las tropas armadas al margen de la ley que están presentes en el país, donde un campesino se ve envuelto en acatos ilícitos exponiendo a su familia y terminado en como integrante de la guerrilla, viviendo momentos de desolación, distanciamiento familiar y búsquedas de salida. De este caso se plantean acciones y estrategia psicosociales para contrarrestar los hechos violentos. Palabras claves: violencia, dolor, miedo, victimas.In this document we capture the analysis of two cases proposed by the “activities guide of the diploma course of deepening psychosocial accompaniment in scenarios of violence”, where the case of Camilo is exposed, a young man who flees from the violence of Quibdó, since he was a child he has been in violent scenarios He has seen the evil, the pain, the uprooting of his roots and relatives, he tried to be a leader by placing his voice for others but he was silent, many times he was threatened and in some cases he was almost recruited by groups outside the law, He was also victims of bad accusations by the state justice entities. To close the case, some reflective, circular and strategic questions are articulated. Then we go on to analyze the “colored rocks” case, which is also an environment of violence, including the illegal armed troops that are present in the country, where a peasant is involved in illegal acts exposing his family and ended up as a member of the guerrilla, experiencing moments of desolation, family distancing and searching for a way out. From this case, psychosocial actions and strategies are proposed to counteract violent acts. Keywords: violence, pain, fear, victims

Neuro-immune signatures in chronic low back pain subtypes

We recently showed that patients with different chronic pain conditions (such as chronic low back pain, fibromyalgia, migraine, and Gulf War Illness) demonstrated elevated brain and/or spinal cord levels of the glial marker 18 kDa translocator protein, which suggests that neuroinflammation might be a pervasive phenomenon observable across multiple etiologically heterogeneous pain disorders. Interestingly, the spatial distribution of this neuroinflammatory signal appears to exhibit a degree of disease specificity (e.g. with respect to the involvement of the primary somatosensory cortex), suggesting that different pain conditions may exhibit distinct “neuroinflammatory signatures”. To further explore this hypothesis, we tested whether neuroinflammatory signal can characterize putative etiological subtypes of chronic low back pain patients based on clinical presentation. Specifically, we explored neuroinflammation in patients whose chronic low back pain either did or did not radiate to the leg (i.e. “radicular” vs. “axial” back pain). Fifty-four chronic low back pain patients, twenty-six with axial back pain (43.7 ± 16.6 y.o. [mean±SD]) and twenty-eight with radicular back pain (48.3 ± 13.2 y.o.), underwent PET/MRI with [11C]PBR28, a second-generation radioligand for the 18 kDa translocator protein. [11C]PBR28 signal was quantified using standardized uptake values ratio (validated against volume of distribution ratio; n = 23). Functional MRI data were collected simultaneously to the [11C]PBR28 data 1) to functionally localize the primary somatosensory cortex back and leg subregions and 2) to perform functional connectivity analyses (in order to investigate possible neurophysiological correlations of the neuroinflammatory signal). PET and functional MRI measures were compared across groups, cross-correlated with one another and with the severity of “fibromyalgianess” (i.e. the degree of pain centralization, or “nociplastic pain”). Furthermore, statistical mediation models were employed to explore possible causal relationships between these three variables. For the primary somatosensory cortex representation of back/leg, [11C]PBR28 PET signal and functional connectivity to the thalamus were: 1) higher in radicular compared to axial back pain patients, 2) positively correlated with each other and 3) positively correlated with fibromyalgianess scores, across groups. Finally, 4) fibromyalgianess mediated the association between [11C]PBR28 PET signal and primary somatosensory cortex-thalamus connectivity across groups. Our findings support the existence of “neuroinflammatory signatures” that are accompanied by neurophysiological changes, and correlate with clinical presentation (in particular, with the degree of nociplastic pain) in chronic pain patients. These signatures may contribute to the subtyping of distinct pain syndromes and also provide information about inter-individual variability in neuro-immune brain signals, within diagnostic groups, that could eventually serve as targets for mechanism-based precision medicine approaches

Neuroimmune activation and increased brain aging in chronic pain patients after the COVID-19 pandemic onset

The COVID-19 pandemic has exerted a global impact on both physical and mental health, and clinical populations have been disproportionally affected. To date, however, the mechanisms underlying the deleterious effects of the pandemic on pre-existing clinical conditions remain unclear. Here we investigated whether the onset of the pandemic was associated with an increase in brain/blood levels of inflammatory markers and MRI-estimated brain age in patients with chronic low back pain (cLBP), irrespective of their infection history. A retrospective cohort study was conducted on 56 adult participants with cLBP (28 ‘Pre-Pandemic’, 28 ‘Pandemic’) using integrated Positron Emission Tomography/ Magnetic Resonance Imaging (PET/MRI) and the radioligand [11C]PBR28, which binds to the neuroinflammatory marker 18 kDa Translocator Protein (TSPO). Image data were collected between November 2017 and January 2020 (‘Pre-Pandemic’ cLBP) or between August 2020 and May 2022 (‘Pandemic’ cLBP). Compared to the Pre-Pandemic group, the Pandemic patients demonstrated widespread and statistically significant elevations in brain TSPO levels (P =.05, cluster corrected). PET signal elevations in the Pandemic group were also observed when 1) excluding 3 Pandemic subjects with a known history of COVID infection, or 2) using secondary outcome measures (volume of distribution -VT- and VT ratio - DVR) in a smaller subset of participants. Pandemic subjects also exhibited elevated serum levels of inflammatory markers (IL-16; P <.05) and estimated BA (P <.0001), which were positively correlated with [11C]PBR28 SUVR (r’s ≥ 0.35; P’s < 0.05). The pain interference scores, which were elevated in the Pandemic group (P <.05), were negatively correlated with [11C]PBR28 SUVR in the amygdala (r = −0.46; P<.05). This work suggests that the pandemic outbreak may have been accompanied by neuroinflammation and increased brain age in cLBP patients, as measured by multimodal imaging and serum testing. This study underscores the broad impact of the pandemic on human health, which extends beyond the morbidity solely mediated by the virus itself

Temas Socio-Jurídicos. Volumen 18 No. 38 Junio 2000

La revista Temas Socio-Jurídicos en su edición número 38, quiere destacar la lucha del pueblo U’WA por su supervivencia étnica y cultural; por tal razón hemos dedicado nuestra portada a un exponente de la comunidad, así como el artículo escrito por Javier Vesga Flórez, sobre los problemas generados a la comunidad U‘wa por el proyecto petrolífero del Bloque Samoré.The Socio-Legal Issues magazine in its 38th edition wants to highlight the struggle of the U'WA people for their ethnic and cultural survival; For this reason, we have dedicated our cover to an exponent of the community, as well as the article written by Javier Vesga Flórez, about the problems caused to the U‘wa community by the oil project of the Samoré Block

Temas Socio-Jurídicos. Volumen 17 No. 37 Diciembre 1999

Al cierre de la edición número 37 de la Revista Temas Socio- Jurídicos, registramos la desaparición de la profesora de la Universidad Nacional de Colombia Virginia Gutierrez De Pineda, antropóloga santandereana, profesora, quien en varias oportunidades honró con su presencia y su prestancia a la Universidad Autónoma de Bucaramanga, en especial la Maestría en Derecho de Familia, en la cual atendió el área relacionada con los conflictos entre los géneros, la pareja y la familia. Gus enseñanzas, su acción vital, su permanente indagación de la realidad del país han de servir de ejemplo a quienes deseen seguir la senda de la ciencia y conquistar horizontes de conocimiento. Como homenaje a esta mujer pionera, la revista publica una de sus últimas conferencias pronunciadas en la Universidad, denominada el conflicto en la relación de los géneros. Dos escritos salidos de la pluma del profesor Alfonso Gómez Gómez, el primero sobre el resurgimiento de las provincias, el segundo sobre las Asambleas Departamentales, incitan a la reflexión cobre la necesidad de una reconfiguración de la estructura político-administrativa de las regiones en el País. Proseguimos con la divulgación del ensayo sobre Institutos Jurídicos Básicos, la segunda parte, donde se exponen los fundamentos económico-sociales de las instituciones jurídicas y sus expresiones abstractas en el orden de los conceptos.At the close of the 37th edition of the Socio-Legal Issues Magazine, we recorded the disappearance of the professor at the National University of Colombia, Virginia Gutierrez De Pineda, an anthropologist from Santander, professor, who on several occasions honored the Autonomous University of Bucaramanga, especially the Master's Degree in Family Law, in which he dealt with the area related to conflicts between genders, couples and family. Gus teachings, his vital action, his permanent investigation of the reality of the country must serve as an example to those who wish to follow the path of science and conquer horizons of knowledge. As a tribute to this pioneering woman, the magazine publishes one of her last lectures given at the University, called the conflict in the relationship between genders. Two writings from the pen of Professor Alfonso Gómez Gómez, the first on the resurgence of the provinces, the second on the Departmental Assemblies, encourage reflection on the need for a reconfiguration of the political-administrative structure of the regions in the Country . We continue with the disclosure of the essay on Basic Legal Institutes, the second part, where the socio-economic foundations of legal institutions and their abstract expressions in the order of concepts are exposed