Imaging systems in medicine

Top PDF Imaging systems in medicine:

PS 3.3-2009 Digital Imaging and Communications in Medicine (DICOM) Part 3: Information Object Definitions

PS 3.3-2009 Digital Imaging and Communications in Medicine (DICOM) Part 3: Information Object Definitions

This Section defines the Information Object for X-Ray Radiofluoroscopic Imaging that includes those data elements and information objects necessary for the interchange of digital X-Ray RF Image data. The XRF IOD is applicable to X-Ray acquisition systems equipped with an image receptor whose plane is parallel to the table plane where the patient is. This Table has in general the ability to be tilted. Furthermore the X-Ray source may be supported by a column that can be angulated to adjust the incidence of the X-Ray beam on the image receptor plan. An equipment based coordinated system is used to track these angles.
Mostrar más

1286 Lee mas

PS 3.5-2011 Digital Imaging and Communications in Medicine (DICOM) Part 5: Data Structures and Encoding

PS 3.5-2011 Digital Imaging and Communications in Medicine (DICOM) Part 5: Data Structures and Encoding

Part 1 of the JPEG-LS Standard sets out requirements and implementation guidelines for the coded representation of compressed image data to be interchanged between applications. The processes and representations are intended to be generic in order to support the broad range of applications for color and grayscale still images for the purpose of communications and storage within computer systems. The JPEG-LS Standard specifies a single lossy (near-lossless) code process that can achieve lossless compression by constraining the absolute error value during encoding to zero. The lossless and lossy (near-lossless) coding is based on a predictive scheme with statistical modeling, in which differences between pixels and their surround are computed and their context modeled prior to coding, with a run- length escape mechanism. This scheme achieves consistently better compression in lossless mode than the lossless processes of JPEG defined in ISO 10918-1, with less complexity.
Mostrar más

117 Lee mas

PS 3.5-2009 Digital Imaging and Communications in Medicine (DICOM) Part 5: Data Structures and Encoding

PS 3.5-2009 Digital Imaging and Communications in Medicine (DICOM) Part 5: Data Structures and Encoding

Part 1 of the JPEG-LS Standard sets out requirements and implementation guidelines for the coded representation of compressed image data to be interchanged between applications. The processes and representations are intended to be generic in order to support the broad range of applications for color and grayscale still images for the purpose of communications and storage within computer systems. The JPEG-LS Standard specifies a single lossy (near-lossless) code process that can achieve lossless compression by constraining the absolute error value during encoding to zero. The lossless and lossy (near-lossless) coding is based on a predictive scheme with statistical modeling, in which differences between pixels and their surround are computed and their context modeled prior to coding, with a run- length escape mechanism. This scheme achieves consistently better compression in lossless mode than the lossless processes of JPEG defined in ISO 10918-1, with less complexity.
Mostrar más

116 Lee mas

RNA Interference in Biology and Medicine

RNA Interference in Biology and Medicine

Even at this early stage of understanding the molec- ular mechanisms of RNAi and in the development of methods for the use of RNAi technology for selective gene silencing, it is clear that RNAi will be a widely used tool for establishing the functions of genes. The ability to selectively deplete a single protein of interest in cultured cells using siRNAs, and plasmids and viral vectors, is now established. Improvements on the currently avail- able protocols for RNAi are being made, and the meth- ods are being applied by thousands of investigators in diverse fields. With the advent of these methods has come an explosion of studies that have employed RNAi. Indeed, although there were only nine publications listed on Medline in the years 1987 through 1998 inclu- sive, there are 631 listed from 1999 to the time of writing of this article. The current status of RNAi as an exper- imental tool is such that many investigators are now aware of the technology, but most have not yet imple- mented it in their own studies. The development of RNAi kits by several companies will facilitate the imple- mentation of RNAi methods by essentially any investi- gator, regardless of their knowledge of RNAi mecha- nisms. However, major hurdles remain to be crossed, including the application of RNAi methods to in vivo studies. Once it becomes possible to reliably target a specific gene and deplete the protein encoded by that gene from one or all cell types in an organism, a wealth of information will flow from studies of processes rang- ing from embryogenesis to the function of organ sys- tems.
Mostrar más

20 Lee mas

Discovery of four gravitationally lensed quasars from the Sloan Digital Sky Survey

Discovery of four gravitationally lensed quasars from the Sloan Digital Sky Survey

The purpose of the Sloan Digital Sky Survey Quasar Lens Search (SQLS; Oguri et al. 2006) is to construct a large statistical lens sample in optical band. The SQLS searches for lensed quasars among spectroscopically confirmed quasar catalogs in the Sloan Digital Sky Survey (SDSS; York et al. 2000). Thus far we have discovered >20 new lensed quasars as well as several previously known lenses in the SDSS footprint (e.g., Kayo et al. 2007, and references therein); therefore it has already become the largest statistical sample of strongly lensed quasars. Inada et al. (2008) presented the first statistical lens sample of the SQLS from the Data Release 3 (DR3).
Mostrar más

7 Lee mas

Role of pharmacogenetics in personalized medicine in hepatology

Role of pharmacogenetics in personalized medicine in hepatology

Genetic studies on DILI susceptibility • DILIGEN UK-based • Primarily concerned with DILI due to amoxicillinclavulanate, flucloxacillin, anti-TB agents • Now complete • iDILIC worldwide [r]

39 Lee mas

Cardiotoxicidad, strain: evidencia actual

Cardiotoxicidad, strain: evidencia actual

The initial assessment should consist of a history and physical examination aimed at assessing the presence of heart disease, ECG to detect arrhythmias or alterations in the QTc interval, echocardiogram and biomarkers for functional and structural assessment. Recommend healthy lifestyles, identify and establish a correct treatment for CVRF. Patients with CVRF present a higher risk of developing cardiotoxicity. CV risk factors are considered: unfavorable lifestyle (smoking, overweight and reduced physical activity) pre-existing diseases such as dyslipidemia, hypertension, diabetes, coronary heart disease, heart failure, stroke or thromboembolic events. Patients with arrhythmias and ventricular dysfunction with EF lower than 50-55% are considered high risk group to develop cardiotoxicity with oncological treatment.
Mostrar más

6 Lee mas

Optogenética: el uso de la luz para revertir la paraálisis por accidentes cerebrovasculares

Optogenética: el uso de la luz para revertir la paraálisis por accidentes cerebrovasculares

inhibitors in the contralesional hemisphere that are impeding the connection attempts from the ipsilateral neurons that can still communicate. If we can silence the inhibitors, the remaining neurons located near the space in which the insult occurred and which are not damaged but were being inhibited, will be able to carry out their functions. This kind of therapy can be invasive, like epidural stimulation, or non-invasive, like transcranial magnetic stimulation (TMS). Studies show promise for non-invasive methods, like transcranial direct current stimulation (tDCS). However, these methods cannot discriminate the type of cell they stimulate, therefore, when stimulating one specific area, they can activate or inhibit all cell types. This can lead to psychiatric, motor or speech problems (Coleman et al., 2017; Transcranial Magnetic Stimulation, n.d.; Azad et al., 2016; Cheng et al., 2014). Invasive cortical stimulation allows a bigger stimulus at a more precise location and have been proven to be safe in preclinical and pilot human studies but remain unstudied because of a discontinuity in the sponsorship of the group studying this (Azad et al., 2016). Another type of neuromodulation that has been studied is cerebellar stimulation, which leads to clinical improvements in motor recovery and plastic reorganization (Azad et al., 2016). Vagal stimulation has also been stipulated to be efficient and has been shown to be safe, however, further studying is needed.(Azad et al., 2016)
Mostrar más

73 Lee mas

Medicine Science in Sports Exercise ®

Medicine Science in Sports Exercise ®

La meta de beber durante el ejercicio es prevenir la deshidratación excesiva (>2% de pérdida de peso corporal por déficit de agua) y los cambios excesivos en el balance de electrolit[r]

25 Lee mas

La escala CURB-65 como índice pronóstico inicial en la enfermedad no quirúrgica

La escala CURB-65 como índice pronóstico inicial en la enfermedad no quirúrgica

Ya en 1837 William Farr 2 abogó en el British Annals of Medicine, por el método científico-aritmético como condición indispensable para el avance médico. Procurando que el componente de ciencia en la profesión médica no desbanque su faceta de arte y oficio 3 , se han buscado en los últimos años herramientas apropiadas para un abordaje sistemático del paciente. Y así, a principios de la década de los 80 comenzaron a desarrollarse las escalas o índices de gravedad. De todos ellos, la escala APACHE (Acute Physiology And Chronic Health Evaluation) fue pionera y referencia de las demás. La desarrollaron Knaus y cols. 4, 5 en el ámbito de la Medicina Intensiva, tras asistir al desgraciado caso de una paciente que falleció en la UCI en presencia de sus médicos, disponiendo éstos de ―una información detallada y exhaustiva, pero imposible de organizar y analizar en el tiempo requerido‖. La escala APACHE se validó en 805 pacientes ingresados en UCI en dos hospitales norteamericanos tras el análisis de múltiples variables obtenidas al ingreso. En el modelo final se seleccionaron aquéllas que mejor se relacionaban con la gravedad. Desde entonces, la escala ha sido revisada en varias ocasiones, para optimizar la información facilitada por el primer modelo 6,7,8 . La versión más actualizada es la APACHE IV 8 .
Mostrar más

165 Lee mas

Brain Changes in Long Term Zen Meditators Using Proton Magnetic Resonance Spectroscopy and Diffusion Tensor Imaging: A Controlled Study

Brain Changes in Long Term Zen Meditators Using Proton Magnetic Resonance Spectroscopy and Diffusion Tensor Imaging: A Controlled Study

non-meditators found that meditators showed greater grey matter concentration in the hippocampus [6,7]. In an examination of participants who underwent mindfulness-based stress reduction, structural changes in the hippocampus were detectable within a period of only 8 weeks [4]. In addition, the cumulative hours of meditation training have been positively correlated with grey matter concentration in the ventromedial PFC in experienced meditators [8]. Functional MRI studies found that individuals who had completed a mindfulness-based stress reduction course demonstrated increased insula activation when they focused on their momentary experience compared with individuals who had not practiced mindfulness [9]. This study also found increased activation of the secondary somatosensory area, which is relevant for the processing of exteroceptive sensory events [9]. In addition, during mindfulness meditation, experienced mindfulness medita- tors show greater activation in the dorso-medial PFC and rostral ACC compared with non-meditators [9]. After participants completed an 8-week mindfulness-based stress reduction course, Farb et al. [10] found increased activity in participants’ ventro- lateral PFC, which the authors interpreted as augmented inhibitory control. Recently, a positive association between the describing facet of mindfulness and gray matter volume in the right anterior insula and the right amygdala has been described [11].
Mostrar más

14 Lee mas

Toward a virtual laboratory for the design of acoustic imaging systems

Toward a virtual laboratory for the design of acoustic imaging systems

The need for powerful simulation package devoted to ultrasonic transducers has induced many developments based on finite element techniques. On the other hand, New approaches can be implemented to provide more complete design and analysis tools, including front and back-end electronics. In this paper, examples of computation results are reported concerning 2D acoustic problems (standard probes and 2-2 piezocomposite) and 1-3 connectivity piezocomposites (3D). The use computation results together with a computation simulator is discussed. As a conclusion, The possibility to simulate the construction of an acoustic image using our ultrasonics virtual laboratory is evoked.
Mostrar más

6 Lee mas

Anotador de anomalías para imágenes médicas

Anotador de anomalías para imágenes médicas

In order to assess new algorithms, a ground truth is needed. Particularly, for algorithms that detect anomalies in medical images, a set of annotated images by medical specialists is necessary. Most software applications used in this kind of tasks comes as value added in medical equipment and carries license problems. These and others available tools do not have the flexibility and functionality required in some cases. In this paper the implementation of a software application for anomaly annotation in medical images is described. This program allows loading images, making annotations, undoing and repeating, drawing (lines, rectangles, ellipses, and free hand), filling, erasing, magnifying, and using different colors and transparency levels.
Mostrar más

8 Lee mas

El papel de la imagenologa en el diagnstico de enfermedades cardiovasculares

El papel de la imagenologa en el diagnstico de enfermedades cardiovasculares

Quantification of valve stenosis is possible by calculating valve orifice area, which can be per- formed with MRI and MDCT. An estimation of the instantaneous peak gradient can only be achieved by MR flow measurements. MR flow measurement is a reliable method to quantify the degree of mild to moderate stenoses. Quantifica- tion of valve regurgitation is possible by measu- rement of the regurgitation fraction with MR flow measurements as well as with MR volumetry/CT volumetry. But only the MR flow measurement is suitable for the quantification of valve regurgita- tion in patients with multiple valves involved or cardiac shunting. MRI and probably MDCT are the most reliable methods in the evaluation of ven- tricular volumes and therefore suitable for the fo- llow-up in patients with valvular heart disease, because changes in volumes are important for the- rapeutic decisions in these patients. The crucial advantages of MRI compared to CT in the diag- nostic of valvular heart diseases however are the absence of radiation exposure, the possibility of quantitative evaluation of valves function using flow measurements and the higher temporal reso- lution as compared to MDCT. 14
Mostrar más

7 Lee mas

Functionalized nanostructures with application in regenerative medicine

Functionalized nanostructures with application in regenerative medicine

shown promising results in tissue repair, they have some drawbacks regarding mechanical properties, degradation, immunogenicity and cross-contamination. Synthetic scaffolds have been constructed using synthetic materials or a combination between natural and synthetic materials. Polyhydroxic acids, polytetrafluoroethylene, steel titanium, or ceramics are examples of synthetic polymers with improved biocompatibility [14,15]. Natural materials, such as collagen, gelatine, chitosan, alginates and silk or synthetic poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA), poly-epsiloncaprolactone (PCL), or polyvinyl alcohol (PVA) polymers, are the most common materials employed for the fabrication of nanofibre scaffolds. These matrices can be created with high structural precision, using complex polymers and assembly techniques, to control material properties such as stiffness, degradation and porosity. The advent of nanotechnology has allowed further developments in the field of biomaterials. Suitable nano-modified surfaces create a nanotopography which facilitates cell adhesion and can induce a better cellular response and specific cell differentiation than untreated surfaces [16]. For example, nano-structured PLGA surfaces have been shown to accelerate chondrocyte adhesion and proliferation, as well as extracellular matrix production [17,18]. Furthermore, vascular graft (PLGA) and stent (titanium) surfaces with nanometer surface roughness improve endothelial cell functions as compared to nano-smooth polymer and titanium surfaces [19,20].
Mostrar más

40 Lee mas

Mtodo NLS 3D en el diagnstico de la enfermedad vascular

Mtodo NLS 3D en el diagnstico de la enfermedad vascular

In addition, the 3D NLS-method makes it possible to diagnose portal hypertension, its extent and the permeability of Porto-systemic shunts. NLS is very sensitive in determining the extent of peripancreatic vessel involvement with pancreas cancer which is essentially important for the choice of tactics for surgical treatment. NLS makes it possible to determine affected renal vessels (both veins and arteries), which is very important for the correct choice of hypotensive drug in the case of arterial hypertension 1-4 .

6 Lee mas

Correlación entre la resonancia magnética de imagen (RMI) y la regeneración histológica del nervio periférico

Correlación entre la resonancia magnética de imagen (RMI) y la regeneración histológica del nervio periférico

28 Figura 9: Imagen de tensor de difusión con reconstrucción tridimensional y tractografía de nervios periféricos de ratón ex vivo. El seguimiento de la fibra con un umbral FA de 0.5 se realizó con los datos del tensor de difusión recogidos de los nervios seccionados. Se expone toda la muestra de tejido nervioso (izquierda, gris, reconstruida a partir de imágenes potenciadas en T2) y el resultado del seguimiento de fibra (derecha, roja). Las flechas marcan el corte transversal (amarillo). En los nervios transeccionados la orientación del tracto fibroso no está bien alineada y desaparecen distalmente a la transección. (Lehmann HC, Zhang J, Mori S, Sheikh KA. Diffusion tensor imaging to assess axonal regeneration in peripheral nerves. Exp Neurol. 2010; 223(1):238-44)
Mostrar más

32 Lee mas

Direct oxygen imaging in titania nanocrystals

Direct oxygen imaging in titania nanocrystals

Figure 1 shows unprocessed STEM images of rutile and anatase nanocrystals. Figures 1(A) and (B) are simultaneously recorded HAADF and BF images of rutile h110i. Figures 1(C) and (D) are the intensity profiles of the white lines in figures 1(A) and (B), respectively. In the HAADF image of rutile h 110 i (figure 1(A)), the positions of the oxygen rows between Ti only rows are not resolved; two kinds of Ti-containing atomic columns can clearly be discriminated. The brighter contrast corresponds to Ti–O rows, the weaker contrast corresponds to Ti rows. The larger peaks in the intensity line profile are from Ti–O rows (indicated with red arrows), the smaller peaks (labeled with blue arrows) are from Ti only rows. In the bright field image of rutile h 110 i (figure 1(B)), the larger dark contrast corresponds to Ti–O rows and the smaller dark contrast corresponds to Ti rows. The gray strips between Ti rows reveal the positions of oxygen rows, but the two oxygen rows cannot be distinguished. In the intensity line profile of the bright field image, the larger troughs are from Ti–O columns and the smaller ones are from Ti rows. In the HAADF image of anatase (100), the titanium rows are revealed as bright pairs of spots, the oxygen columns between the titanium pairs not being visible; in the simultaneously recorded bright field, the larger dark
Mostrar más

10 Lee mas

Calcium Imaging in Neuron Cell Death

Calcium Imaging in Neuron Cell Death

2. The set-up in use is made of a Zeiss Axiovert S100 TV inverted microscope (Carl Zeiss Inc., Gottingen, Germany) equipped with a Zeiss Fluar 40×, 1.3 NA oil objective, a Xenon XBO75 fluorescence excitation lamp or a XCITE illumination system (EXFO, Ontario, Canada), an excitation filter wheel (Sutter Instrument Company, Novato, CA) with band pass filters for Fura2 excitation (340 and 380 nm) and a Fura2 dichroic mir- ror. Attached in the lateral port of the microscope is a Hamamatsu Orca ER Digital Camera (Hamamatsu Photonics, Hamamatsu, Japan). Camera capturing and filter wheels are handled by Aquacosmos software (Hamamatsu Photonics). A schematic of the imaging setup has been described in detail in a recent chapter [8].
Mostrar más

16 Lee mas

Study, design and validation of a framework model for smoke and particle-filled atmospheres

Study, design and validation of a framework model for smoke and particle-filled atmospheres

The lack of vision leads automatically to a sudden loss of spatial perception. This fact, together with the relative “oblivion” of the rest of the senses results in an im- portant lack of information about the environment, which, in turn, can make the subject feel uneasy, reducing his perception of safety and increasing stress levels. Many studies have been conducted in order to assess the influence of working conditions for high-risk workers in an aggregated manner [29, 30]. These works analyze physiological parameters like heart rate and ventilation (air consump- tion) of trained subjects in real-world situations to infer health related problems and propose workarounds as well as a number of recommendations. More mod- ern research has led to the development of devices capable of triggering an alarm if the subject under monitorization is in danger [31].
Mostrar más

269 Lee mas

Show all 10000 documents...