RESUMO
Abdominal hemorrhage is an important clinical disease that can be life-threatening in severe cases. Therefore, timely detection and treatment of abdominal hemorrhage is crucial for the health and safety of patients. Magnetic induction tomography is a non-invasive, nonradioactive, and non-contact electromagnetic imaging technology with potential application value for disease screening and continuous monitoring. In this paper, a simulation model of electrical impedance distribution close to the real human abdominal tissue was constructed, and based on this model, the magnetic induction tomography simulation method of internal bleeding was studied by the finite element numerical method, and the comparison was verified by phantom experiments. The eddy current density distribution inside the abdominal tissue and the magnetic induction phase data at the tissue boundary are solved, and sensitivity analysis of phase differences caused by changes in the radius and position of bleeding volume was conducted, and three sensitivity indicators were proposed. Both the simulation and phantom experiment show that when there are six types of tissues with different conductivity in the abdomen, the radius of bleeding increases from 10 to 30 mm, and the radius phase difference sensitivity index Ar increases approximately linearly monotonically. Its radius transformation sensitivity Kr is 3.0961 × 10-5°/cm. When the position of the bleeding volume changes, the sensitivity index Ax of the x-axis displacement phase difference shows a quasilinear monotonic decrease, and the x-axis displacement sensitivity Kx is -6.3744 × 10-6°/cm. The y-axis displacement phase difference sensitivity Ay index shows a quasilinear relationship and monotonically increases, with a y-axis displacement sensitivity Ky of 5.2870 × 10-4°/cm. The results indicate that the phase difference sensitivity before and after the occurrence of bleeding can be used as a quantitative monitoring indicator to monitor the occurrence and trend of intra-abdominal hemorrhage, laying the foundation for the preliminary screening and continuous monitoring of abdominal hemorrhage diseases using magnetic induction imaging.
Assuntos
Abdome , Hemorragia , Imagens de Fantasmas , Tomografia , Hemorragia/diagnóstico por imagem , Humanos , Tomografia/instrumentação , Tomografia/métodos , Abdome/diagnóstico por imagem , Simulação por Computador , Análise de Elementos FinitosAssuntos
Impedância Elétrica , Respiração com Pressão Positiva , Síndrome do Desconforto Respiratório , Humanos , Respiração com Pressão Positiva/métodos , Síndrome do Desconforto Respiratório/terapia , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Síndrome do Desconforto Respiratório/fisiopatologia , Tomografia/métodos , Masculino , Criança , FemininoRESUMO
Electrical Impedance Tomography (EIT) is a groundbreaking, non-invasive, and radiation-free imaging technique for continuous, real-time ventilation monitoring. It also has an application in pulmonary perfusion monitoring. EIT quantifies ventilation and perfusion patterns across the lung from the measurement and processing of impedance changes in the thorax. It is a powerful tool for clinicians to visualize breath-by-breath changes in pulmonary function. An innovative application of EIT is its ability to assess pulmonary perfusion using the kinetic analysis of a hypertonic solution injection during a breath-hold. The solution generates an impedance change in the thorax as it circulates through the pulmonary vasculature. This indirect method allows for the estimation of perfusion patterns, contributing significantly to our understanding of pulmonary blood flow dynamics at the bedside. EIT is not just a tool for monitoring but also can be critical for the diagnosis of respiratory pathologies such as pneumothorax and bronchial intubation. It can help identify the etiology of ventilation/perfusion (V/Q) mismatch in patients receiving invasive mechanical ventilation, which is not possible with other diagnostic tools. Moreover, EIT can assist in the individual optimization of ventilator settings, such as Positive End-Expiratory Pressure (PEEP) titration and tidal volume improving oxygenation and lung health in critical care. In summary, EIT represents a paradigm shift in bedside pulmonary monitoring and diagnostics. Its non-invasive nature and immediacy of data make EIT an indispensable tool in modern respiratory medicine. With its growing applications, EIT will be pivotal in advancing our understanding of and approach to respiratory care, particularly in intensive care settings.
Assuntos
Impedância Elétrica , Pulmão , Tomografia , Humanos , Tomografia/métodos , Pulmão/fisiologia , Pulmão/diagnóstico por imagem , Pulmão/irrigação sanguínea , Unidades de Terapia Intensiva , Monitorização Fisiológica/métodosRESUMO
In the rapidly evolving field of human-machine interfaces (HMIs), high-resolution wearable electronic skin (e-skin) is essential for user interaction. However, traditional array-structured tactile interfaces require increased number of interconnects, while soft material-based computational methods have limited functionalities. Here, we introduce a thin and soft e-skin for tactile interfaces, offering high mapping capabilities through electrical impedance tomography (EIT). We employed an organic/inorganic hybrid structure with simple, cost-effective fabrication processes, ensuring flexibility and stability. The conductive and stretchable sensing domain includes a micropatterned multiwall carbon nanotube and elastomer composite. The skin-like tactile interface effectively detects pressure-induced conductivity changes, offering superior spatiotemporal resolution with fewer interconnects (pixel/interconnects >57). This EIT-based tactile interface discerns external pressures to a submillimeter degree and vertical deformations of a few hundred micrometers. It sustains stable functions under external damage or environmental changes, confirming its suitability for persistent wearable use. We demonstrate practical applications in real-time HMIs: handwriting recognition and drone control.
Assuntos
Impedância Elétrica , Tomografia , Tato , Dispositivos Eletrônicos Vestíveis , Humanos , Tomografia/métodos , Tomografia/instrumentação , Tato/fisiologia , Nanotubos de Carbono/química , PeleRESUMO
The ability to image tissues in three dimensions (3D) with label-free molecular contrast at the mesoscale would be a valuable capability in biology and biomedicine. Here, we introduce Raman spectral projection tomography (RSPT) for volumetric molecular imaging with optical sub-millimeter spatial resolution. We have developed a RSPT imaging instrument capable of providing 3D molecular contrast in transparent and semi-transparent samples. We also created a computational pipeline for multivariate reconstruction to extract label-free spatial molecular information from Raman projection data. Using these tools, we demonstrate imaging and visualization of phantoms of various complex shapes with label-free molecular contrast. Finally, we apply RSPT as a tool for imaging of molecular gradients and extracellular matrix heterogeneities in fixed and living tissue-engineered constructs and explanted native cartilage tissues. We show that there exists a favorable balance wherein employing Raman spectroscopy, with its advantages in live cell imaging and label-free molecular contrast, outweighs the reduction in imaging resolution and blurring caused by diffuse photon propagation. Thus, RSPT imaging opens new possibilities for label-free molecular monitoring of tissues.
Assuntos
Imageamento Tridimensional , Imagem Molecular , Imagens de Fantasmas , Análise Espectral Raman , Análise Espectral Raman/métodos , Imageamento Tridimensional/métodos , Animais , Imagem Molecular/métodos , Engenharia Tecidual/métodos , Humanos , Tomografia/métodos , Cartilagem/diagnóstico por imagem , Cartilagem/metabolismo , Matriz Extracelular/metabolismo , CamundongosRESUMO
Bioimpedance imaging aims to generate a 3D map of the resistivity and permittivity of biological tissue from multiple impedance channels measured with electrodes applied to the skin. When the electrodes are distributed around the body (for example, by delineating a cross section of the chest or a limb), bioimpedance imaging is called electrical impedance tomography (EIT) and results in functional 2D images. Conventional EIT systems rely on individually cabling each electrode to master electronics in a star configuration. This approach works well for rack-mounted equipment; however, the bulkiness of the cabling is unsuitable for a wearable system. Previously presented cooperative sensors solve this cabling problem using active (dry) electrodes connected via a two-wire parallel bus. The bus can be implemented with two unshielded wires or even two conductive textile layers, thus replacing the cumbersome wiring of the conventional star arrangement. Prior research demonstrated cooperative sensors for measuring bioimpedances, successfully realizing a measurement reference signal, sensor synchronization, and data transfer though still relying on individual batteries to power the sensors. Subsequent research using cooperative sensors for biopotential measurements proposed a method to remove batteries from the sensors and have the central unit supply power over the two-wire bus. Building from our previous research, this paper presents the application of this method to the measurement of bioimpedances. Two different approaches are discussed, one using discrete, commercially available components, and the other with an application-specific integrated circuit (ASIC). The initial experimental results reveal that both approaches are feasible, but the ASIC approach offers advantages for medical safety, as well as lower power consumption and a smaller size.
Assuntos
Impedância Elétrica , Eletrodos , Dispositivos Eletrônicos Vestíveis , Humanos , Fontes de Energia Elétrica , Tomografia/instrumentação , Tomografia/métodos , Desenho de Equipamento , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodosRESUMO
Flexible electronic skin (e-skin) can enable robots to have sensory forms similar to human skin, enhancing their ability to obtain more information from touch. The non-invasive nature of electrical impedance tomography (EIT) technology allows electrodes to be arranged only at the edges of the skin, ensuring the stretchability and elasticity of the skin's interior. However, the image quality reconstructed by EIT technology has deteriorated in multi-touch identification, where it is challenging to clearly reflect the number of touchpoints and accurately size the touch areas. This paper proposed an EIT-based flexible tactile sensor that employs self-made hydrogel material as the primary sensing medium. The sensor's structure, fabrication process, and tactile imaging principle were elaborated. To improve the quality of image reconstruction, the fast iterative shrinkage-thresholding algorithm (FISTA) was embedded into the EIDORS toolkit. The performances of the e-skin in aspects of assessing the touching area, quantitative force sensing and multi-touch identification were examined. Results showed that the mean intersection over union (MIoU) of the reconstructed images was improved up to 0.84, and the tactile position can be accurately imaged in the case of the number of the touchpoints up to seven (larger than two to four touchpoints in existing studies), proving that the combination of the proposed sensor and imaging algorithm has high sensitivity and accuracy in multi-touch tactile sensing. The presented e-skin shows potential promise for the application in complex human-robot interaction (HRI) environments, such as prosthetics and wearable devices.
Assuntos
Algoritmos , Impedância Elétrica , Hidrogéis , Tomografia , Tato , Dispositivos Eletrônicos Vestíveis , Humanos , Tato/fisiologia , Tomografia/métodos , Tomografia/instrumentação , Hidrogéis/química , Processamento de Imagem Assistida por Computador/métodos , Pele/diagnóstico por imagem , Pele/química , Eletrodos , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentaçãoRESUMO
Objective. Geometrical region of interest (ROI) selection in electrical impedance tomography (EIT) monitoring may lack sensitivity to subtle changes in ventilation distribution. Therefore, we demonstrate a new physiological method for ROI definition. This is relevant when using ROIs to compute subsequent EIT-parameters, such as the ventral-to-dorsal ratio during a positive end-expiratory pressure (PEEP) trial.Approach.Our physiological approach divides an EIT image to ensure exactly 50% tidal impedance variation in the ventral and dorsal region. To demonstrate the effects of our new method, EIT measurements during a decremental PEEP trial in 49 mechanically ventilated ICU-patients were used. We compared the center of ventilation (CoV), a robust parameter for changes in ventro-dorsal ventilation distribution, to our physiological ROI selection method and different commonly used ROI selection methods. Moreover, we determined the impact of different ROI selection methods on the PEEP level corresponding to a ventral-to-dorsal ratio closest to 1.Main results.The division line separating the ventral and dorsal ROI was closer to the CoV for our new physiological method for ROI selection compared to geometrical ROI definition. Moreover, the PEEP level corresponding to a ventral-to-dorsal ratio of 1 is strongly influenced by the chosen ROI selection method, which could have a profound clinical impact; the within-subject range of PEEP level was 6.2 cmH2O depending on the chosen ROI selection method.Significance.Our novel physiological method for ROI definition is sensitive to subtle ventilation-induced changes in regional impedance (i.e. due to (de)recruitment) during mechanical ventilation, similar to the CoV.
Assuntos
Impedância Elétrica , Respiração com Pressão Positiva , Tomografia , Humanos , Tomografia/métodos , Masculino , Feminino , Pessoa de Meia-Idade , IdosoRESUMO
Fluorescence lifetime imaging microscopy (FLIM) is a powerful imaging technique that enables the visualization of biological samples at the molecular level by measuring the fluorescence decay rate of fluorescent probes. This provides critical information about molecular interactions, environmental changes, and localization within biological systems. However, creating high-resolution lifetime maps using conventional FLIM systems can be challenging, as it often requires extensive scanning that can significantly lengthen acquisition times. This issue is further compounded in three-dimensional (3D) imaging because it demands additional scanning along the depth axis. To tackle this challenge, we developed a computational imaging technique called light-field tomographic FLIM (LIFT-FLIM). Our approach allows for the acquisition of volumetric fluorescence lifetime images in a highly data-efficient manner, significantly reducing the number of scanning steps required compared to conventional point-scanning or line-scanning FLIM imagers. Moreover, LIFT-FLIM enables the measurement of high-dimensional data using low-dimensional detectors, which are typically low cost and feature a higher temporal bandwidth. We demonstrated LIFT-FLIM using a linear single-photon avalanche diode array on various biological systems, showcasing unparalleled single-photon detection sensitivity. Additionally, we expanded the functionality of our method to spectral FLIM and demonstrated its application in high-content multiplexed imaging of lung organoids. LIFT-FLIM has the potential to open up broad avenues in both basic and translational biomedical research.
Assuntos
Microscopia de Fluorescência , Microscopia de Fluorescência/métodos , Animais , Humanos , Imageamento Tridimensional/métodos , Camundongos , Corantes Fluorescentes/química , Tomografia/métodosRESUMO
INTRODUCTION: The apnea test (AT) is a crucial procedure in determining brain death (BD), with detection of spontaneous breathing efforts serving as a key criterion. Numerous national statutes mandate complete disconnection of the patient from the ventilator during the procedure to open the airway directly to the atmosphere. These regulations mandate visual observation as an exclusive option for detecting breathing efforts. However, reliance on visual observation alone can pose challenges in identifying subtle respiratory movements. CASE PRESENTATION: This case report presents a 55-year-old morbidly obese male patient with suspected BD due to cerebral hemorrhage undergoing an AT. The AT was performed with continuous electrical impedance tomography (EIT) monitoring. Upon detection of spontaneous breathing movements by both visual observation and EIT, the AT was aborted, and the patient was reconnected to the ventilator. EIT indicated a shift in ventilation distribution from the ventral to the dorsal regions, indicating the presence of spontaneous breathing efforts. EIT results also suggested the patient experienced a slow but transient initial recovery phase, likely due to atelectasis induced by morbid obesity, before returning to a steady state of ventilatory support. CONCLUSION: The findings suggest EIT could enhance the sensitivity and accuracy of detecting spontaneous breathing efforts, providing additional insights into the respiratory status of patients during the AT.
Assuntos
Apneia , Morte Encefálica , Impedância Elétrica , Obesidade Mórbida , Tomografia , Humanos , Masculino , Morte Encefálica/diagnóstico , Morte Encefálica/fisiopatologia , Pessoa de Meia-Idade , Apneia/diagnóstico , Apneia/fisiopatologia , Tomografia/métodos , Obesidade Mórbida/complicações , Obesidade Mórbida/fisiopatologia , Respiração , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/complicações , Hemorragia Cerebral/fisiopatologiaRESUMO
Introducción: La anemia es frecuentemente subdiagnosticada dada su vaga sintomatología. Estudios con evaluación subjetiva-visual por expertos describen signos tomográficos sugerentes de anemia, tales como el septo denso. Proponemos que lectores con entrenamiento básico realicen mediciones objetivas de alto poder estadístico para la detección de anemia. Material y Métodos: Se cruzaron datos de tomografía computarizada (TC) de tórax no contrastada (2021) con medición de hemoglobina plasmática (Hb) realizada 24 horas antes o después del estudio tomográfico. Dos estudiantes de Medicina, previamente entrenados, realizaron mediciones de Unidades Hounsfield (UH) en el septo interventri-cular (SIV) y cavidades ventriculares derecho (VD) e izquierdo (VI). Las relaciones SIV/VI y SIV/VD se correlacionaron con los valores de Hb. Se analizó la variabilidad interob-servador y se determinó el punto de corte óptimo para detectar anemia. Resultados: En una muestra de 112 casos, hubo alta concordancia interobservador con r de 0,85 (VD), 0,67 (SIV) y 0,87 (VI). La relación SIV/VI obtuvo el mayor AUC con 0,86 (IC 95%: 0,72 a 0,91), con una sensibilidad de 80% y especificidad de 88% utilizando un punto de corte de 1,15. Conclusiones: La razón SIV/VI con punto de corte de 1,15 es un parámetro confiable para detectar anemia mediante TC de tórax no contrastada, en observadores con entrenamiento básico.
Introduction: Anemia is frequently underdiagnosed given its vague symptomatology. Studies with subjective-visual evaluation by experts describe tomographic signs suggestive of anemia, such as a dense septum. This study aims to evaluate if readers with basic training can perform high statistical value measurements for anemia detection. Material and Methods: Data of non-contrast thoracic computed tomography (CT) (2021) with a measurement of plasma hemoglobin (Hb) performed 24 hours before or after the CT were identified. Two previously trained medical students performed measurements of Hounsfield Units (HU) on the interventricular septum (IVS) and right (RV) and left (LV) ventricular cavities. The SIV/VI and SIV/VD ratios were correlated with Hb values. Interobserver variability was analyzed and the optimal cut-off point to detect anemia was determined. Results: In a sample of 112 cases, there was a high interobserver correlation with r of 0.85 (VD), 0.67 (SIV), and 0.87 (VI). SIV/VI ratio obtained the highest AUC with 0.86 (95% CI: 0.72 to 0.91), with a sensitivity of 80% and specificity of 88% using a cut-off point of 1.15. Conclusions: The SIV/VI ratio with a cut-off point of 1.15 is a reliable parameter to detect anemia using non-contrast chest CT in observers with basic training.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Tomografia , Anemia/diagnóstico por imagem , Estudantes de Medicina , Tórax/diagnóstico por imagem , Hemoglobinas , Chile , Septo Interventricular/diagnóstico por imagem , Ventrículos do CoraçãoRESUMO
El síndrome de Williams-Campbell (SWC) es una entidad clínica caracterizada por la deficiencia de cartílago en la pared bronquial de los bronquios subsegmentarios. Es una condición congénita que por lo general se diagnostica en la niñez, pero hay reportes de caso en la población adulta y se cree que esto se debe a un menor déficit de cartílago. Los síntomas principales de esta condición son la presencia de tos, disnea e infecciones respiratorias a repetición. Radiológicamente, se evidencia la presencia de bronquiectasias de pared delgada. El diagnóstico se basa en descartar otras causas más comunes de bronquiectasias, así como en la identificación de las características radiológicas y la presencia del componente congénito. Presentamos el caso de un joven con síntomas respiratorios desde la infancia, con necesidad de múltiples hospitalizaciones por procesos infecciosos de origen pulmonar a repetición, con lo cual se llega al diagnóstico de un síndrome de Williams-Campbell.
Williams-Campbell syndrome (WCS) is a clinical entity characterized by cartilage deficiency in the bronchial wall of the subsegmental bronchi. It is a congenital condition that is usually diagnosed in childhood, but there are case reports in the adult population, and it is believed that this is due to a minor cartilage deficiency. The main symptoms of this condition are the presence of cough, dyspnea and repeated respiratory infections. Radiologically, the presence of thin-walled bronchiectasis is evident. The diagnosis is based on ruling out other more common causes of bronchiectasis, as well as identifying the radiological characteristics and the presence of the congenital component. We present the case of a young man with respiratory symptoms since childhood requiring multiple hospitalizations due to repeated infectious processes of pulmonary origin, in which the diagnosis of Williams-Campbell syndrome was reached.
Assuntos
Humanos , Masculino , Adulto , Bronquiectasia , Traqueobroncomalácia/diagnóstico , Sinais e Sintomas Respiratórios , Anormalidades Congênitas/diagnóstico , Brônquios , Tomografia , Cartilagem , IontoforeseRESUMO
Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer, a leading cause of cancer-related deaths globally. Initial lesions of PDAC develop within the exocrine pancreas' functional units, with tumor progression driven by interactions between PDAC and stromal cells. Effective therapies require anatomically and functionally relevantin vitrohuman models of the pancreatic cancer microenvironment. We employed tomographic volumetric bioprinting, a novel biofabrication method, to create human fibroblast-laden constructs mimicking the tubuloacinar structures of the exocrine pancreas. Human pancreatic ductal epithelial (HPDE) cells overexpressing the KRAS oncogene (HPDE-KRAS) were seeded in the multiacinar cavity to replicate pathological tissue. HPDE cell growth and organization within the structure were assessed, demonstrating the formation of a thin epithelium covering the acini inner surfaces. Immunofluorescence assays showed significantly higher alpha smooth muscle actin (α-SMA) vs. F-actin expression in fibroblasts co-cultured with cancerous versus wild-type HPDE cells. Additionally,α-SMA expression increased over time and was higher in fibroblasts closer to HPDE cells. Elevated interleukin (IL)-6 levels were quantified in supernatants from co-cultures of stromal and HPDE-KRAS cells. These findings align with inflamed tumor-associated myofibroblast behavior, serving as relevant biomarkers to monitor early disease progression and target drug efficacy. To our knowledge, this is the first demonstration of a 3D bioprinted model of exocrine pancreas that recapitulates its true 3-dimensional microanatomy and shows tumor triggered inflammation.
Assuntos
Bioimpressão , Fibroblastos , Pâncreas Exócrino , Humanos , Pâncreas Exócrino/metabolismo , Fibroblastos/metabolismo , Fibroblastos/citologia , Impressão Tridimensional , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Tomografia , Actinas/metabolismo , Interleucina-6/metabolismo , Engenharia Tecidual , Técnicas de Cocultura , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genéticaRESUMO
In this pilot study, we investigated the utility of handheld ultrasound-guided photoacoustic (US-PA) imaging probe for analyzing ex-vivo breast specimens obtained from female patients who underwent breast-conserving surgery (BCS). We aimed to assess the potential of US-PA in detecting biochemical markers such as collagen, lipids, and hemoglobin, and compare these findings with routine imaging modalities (mammography, ultrasound) and histopathology results, particularly across various breast densities. Twelve ex-vivo breast specimens were obtained from female patients with a mean age of 59.7 ± 9.5 years who underwent BCS. The tissues were illuminated using handheld US-PA probe between 700 and 1100 nm across all margins and analyzed for collagen, lipids, and hemoglobin distribution. The obtained results were compared with routine imaging and histopathological assessments. Our findings revealed that lipid intensity and distribution decreased with increasing breast density, while collagen exhibited an opposite trend. These observations were consistent with routine imaging and histopathological analyses. Moreover, collagen intensity significantly differed (P < 0.001) between cancerous and normal breast tissue, indicating its potential as an additional biomarker for risk stratification across various breast conditions. The study results suggest that a combined assessment of PA biochemical information, such as collagen and lipid content, superimposed on grey-scale ultrasound findings could aid in distinguishing between normal and malignant breast conditions, as well as assist in BCS margin assessment. This underscores the potential of US-PA imaging as a valuable tool for enhancing breast cancer diagnosis and management, offering complementary information to existing imaging modalities and histopathology.
Assuntos
Neoplasias da Mama , Colágeno , Hemoglobinas , Lipídeos , Técnicas Fotoacústicas , Humanos , Feminino , Técnicas Fotoacústicas/métodos , Pessoa de Meia-Idade , Hemoglobinas/análise , Hemoglobinas/metabolismo , Colágeno/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Idoso , Lipídeos/análise , Lipídeos/química , Mama/patologia , Mama/diagnóstico por imagem , Projetos Piloto , Ultrassonografia Mamária/métodos , Tomografia/métodos , BiomarcadoresRESUMO
Diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT) and electrodeless conductivity tensor imaging (CTI) are two emerging modalities that can quantify low-frequency tissue anisotropic conductivity properties by assuming similar properties underlie ionic mobility and water diffusion. While both methods have potential applications to estimating neuro-modulation fields or formulating forward models used for electrical source imaging, a direct comparison of the two modalities has not yet been performed in-vitro or in-vivo. Therefore, the aim of this study was to test the equivalence of these two modalities. We scanned a tissue phantom and the head of human subject using DT-MREIT and CTI protocols and reconstructed conductivity tensor and effective low frequency conductivities. We found both gray and white matter conductivities recovered by each technique were equivalent within 0.05 S/m. Both DT-MREIT and CTI require multiple processing steps, and we further assess the effects of each factor on reconstructions and evaluate the extent to which different measurement mechanisms potentially cause discrepancies between the two methods. Finally, we discuss the implications for spectral models of measuring conductivity using these techniques. The study further establishes the credibility of CTI as an electrodeless non-invasive method of measuring low frequency conductivity properties.
Assuntos
Imagem de Tensor de Difusão , Condutividade Elétrica , Impedância Elétrica , Imagens de Fantasmas , Humanos , Imagem de Tensor de Difusão/métodos , Tomografia/métodos , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , AdultoRESUMO
OBJECTIVE: Our study aimed to investigate the effects of different extracorporeal membrane oxygenation (ECMO) blood flow rates on lung perfusion assessment using the saline bolus-based electrical impedance tomography (EIT) technique in patients on veno-venous (VV) ECMO. METHODS: In this single-centered prospective physiological study, patients on VV ECMO who met the ECMO weaning criteria were assessed for lung perfusion using saline bolus-based EIT at various ECMO blood flow rates (gradually decreased from 4.5 L/min to 3.5 L/min, 2.5 L/min, 1.5 L/min, and finally to 0 L/min). Lung perfusion distribution, dead space, shunt, ventilation/perfusion matching, and recirculation fraction at different flow rates were compared. RESULTS: Fifteen patients were included. As the ECMO blood flow rate decreased from 4.5 L/min to 0 L/min, the recirculation fraction decreased significantly. The main EIT-based findings were as follows. (1) Median lung perfusion significantly increased in region-of-interest (ROI) 2 and the ventral region [38.21 (34.93-42.16)% to 41.29 (35.32-43.75)%, p = 0.003, and 48.86 (45.53-58.96)% to 54.12 (45.07-61.16)%, p = 0.037, respectively], whereas it significantly decreased in ROI 4 and the dorsal region [7.87 (5.42-9.78)% to 6.08 (5.27-9.34)%, p = 0.049, and 51.14 (41.04-54.47)% to 45.88 (38.84-54.93)%, p = 0.037, respectively]. (2) Dead space significantly decreased, and ventilation/perfusion matching significantly increased in both the ventral and global regions. (3) No significant variations were observed in regional and global shunt. CONCLUSIONS: During VV ECMO, the ECMO blood flow rate, closely linked to recirculation fraction, could affect the accuracy of lung perfusion assessment using hypertonic saline bolus-based EIT.
Assuntos
Impedância Elétrica , Oxigenação por Membrana Extracorpórea , Pulmão , Tomografia , Humanos , Oxigenação por Membrana Extracorpórea/métodos , Masculino , Feminino , Estudos Prospectivos , Impedância Elétrica/uso terapêutico , Pessoa de Meia-Idade , Adulto , Tomografia/métodos , Pulmão/irrigação sanguínea , Pulmão/fisiopatologia , Pulmão/diagnóstico por imagem , Solução Salina Hipertônica/uso terapêutico , Idoso , Velocidade do Fluxo Sanguíneo/fisiologiaRESUMO
OBJECTIVE: The study aimed to evaluate the improvements in pulmonary ventilation following a sitting position in ventilated ARDS patients using electrical impedance tomography. METHODOLOGY: A total of 17 patients with ARDS under mechanical ventilation participated in this study, including 8 with moderate ARDS and 9 with severe ARDS. Each patient was initially placed in the supine position (S1), transitioned to sitting position (SP) for 30 min, and then returned to the supine position (S2). Patients were monitored for each period, with parameters recorded. MAIN OUTCOME MEASURES: The primary outcome included the spatial distribution parameters of EIT, regional of interest (ROI), end-expiratory lung impedance (ΔEELI), and parameters of respiratory mechanics. RESULTS: Compared to S1, the SP significantly altered the distribution in ROI1 (11.29 ± 4.70 vs 14.88 ± 5.00 %, p = 0.003) and ROI2 (35.59 ± 8.99 vs 44.65 ± 6.97 %, p ï¼ 0.001), showing reductions, while ROI3 (39.71 ± 11.49 vs 33.06 ± 6.34 %, p = 0.009), ROI4 (13.35 ± 8.76 vs 7.24 ± 5.23 %, p ï¼ 0.001), along with peak inspiratory pressure (29.24 ± 3.96 vs 27.71 ± 4.00 cmH2O, p = 0.036), showed increases. ΔEELI decreased significantly ventrally (168.3 (40.33 - 189.5), p ï¼ 0.0001) and increased significantly dorsally (461.7 (297.5 - 683.7), p ï¼ 0.0001). The PaO2/FiO2 ratio saw significant improvement in S2 compared to S1 after 30 min in the seated position (108 (73 - 130) vs 96 (57 - 129) mmHg, p = 0.03). CONCLUSIONS: The sitting position is associated with enhanced compliance, improved oxygenation, and more homogenous ventilation in patients with ventilated ARDS compared to the supine position. IMPLICATIONS FOR CLINICAL PRACTICE: It is important to know the impact of postural changes on patient pulmonary ventilation in order to standardize safe practices in critically ill patients. It may be helpful in the management among ventilated patients.
Assuntos
Impedância Elétrica , Respiração Artificial , Síndrome do Desconforto Respiratório , Postura Sentada , Humanos , Masculino , Feminino , Síndrome do Desconforto Respiratório/terapia , Síndrome do Desconforto Respiratório/fisiopatologia , Pessoa de Meia-Idade , Idoso , Respiração Artificial/métodos , Respiração Artificial/normas , Tomografia/métodos , Tomografia/normas , Adulto , Posicionamento do Paciente/métodos , Posicionamento do Paciente/normasRESUMO
Regulating the complex microenvironment after tooth extraction to promote alveolar bone regeneration is a pressing challenge for restorative dentistry. In this study, through modulating the mechanical properties of the cellular matrix, we guided various types of cells by self-organizing to form multicellular spheroids (MCSs) and hybridized MCSs with Prussian Blue nanoparticles (PBNPs) in the process. The constructed Prussian Blue nanohybridized multicellular spheroids (PBNPs@MCSs) with empowered antioxidant functions effectively reduced cell apoptosis under peroxidative conditions and exhibited enhanced ability to regulate the microenvironment and promote bone repair both in vitro and in vivo. In addition, the PBNPs@MCSs exhibited enhanced photoacoustic imaging ability to trace low doses of PBNPs. Therefore, the constructed PBNPs@MCSs based on the biomimetic hydrogel can be used as a form of an engraftment building block, with a greater potential for pro-bone repair application in the complex microenvironment of the oral cavity.
Assuntos
Antioxidantes , Regeneração Óssea , Ferrocianetos , Nanopartículas , Técnicas Fotoacústicas , Esferoides Celulares , Ferrocianetos/química , Ferrocianetos/farmacologia , Animais , Regeneração Óssea/efeitos dos fármacos , Antioxidantes/farmacologia , Antioxidantes/química , Esferoides Celulares/efeitos dos fármacos , Nanopartículas/química , Camundongos , Humanos , Tomografia , Apoptose/efeitos dos fármacosRESUMO
La actinomicosis pélvica es una infección poco común del tracto genital inferior y la pelvis. La especie causal más frecuente es la bacteria Actinomyces israelii, y se debe sospechar en toda paciente que presente dolor crónico pélvico y hemorragia uterina. Aunque se manifiesta excepcionalmente en mujeres sin antecedentes de portar dispositivos intrauterinos, es importante considerarla como diagnóstico. Se presenta el caso clínico de una paciente de 12 años con hemorragia uterina anormal resistente al tratamiento, que requirió intervención quirúrgica, incluyendo biopsia endometrial. El diagnóstico resultante fue actinomicosis endometrial. Este caso aporta la actualización del conocimiento sobre esta rara enfermedad y su presentación poco frecuente en adolescentes(AU)
Pelvic actinomycosis is a rare infection of the lower genital tract and pelvis. The most common causative species is the bacterium Actinomyces israelii, and it should be suspected in any patient who presents with chronic pelvic pain and uterine bleeding. Although it occurs exceptionally in women without a history of carrying intrauterine devices, it is important to consider it as a diagnosis. It is presented the clinical case of a 12-year-old patient with abnormal uterine bleeding resistant to treatment, which required surgical intervention, including endometrial biopsy. The resulting diagnosis was endometrial actinomycosis. This case contributes to updating knowledge about this rare disease and its uncommon presentation in adolescents(AU)