Quantitative and Dynamic Imaging of ATM Kinase Activity.

Science.gov (United States)

Nyati, Shyam; Young, Grant; Ross, Brian Dale; Rehemtulla, Alnawaz

2017-01-01

Ataxia telangiectasia mutated (ATM) is a serine/threonine kinase critical to the cellular DNA-damage response, including DNA double-strand breaks (DSBs). ATM activation results in the initiation of a complex cascade of events facilitating DNA damage repair, cell cycle checkpoint control, and survival. Traditionally, protein kinases have been analyzed in vitro using biochemical methods (kinase assays using purified proteins or immunological assays) requiring a large number of cells and cell lysis. Genetically encoded biosensors based on optical molecular imaging such as fluorescence or bioluminescence have been developed to enable interrogation of kinase activities in live cells with a high signal to background. We have genetically engineered a hybrid protein whose bioluminescent activity is dependent on the ATM-mediated phosphorylation of a substrate. The engineered protein consists of the split luciferase-based protein complementation pair with a CHK2 (a substrate for ATM kinase activity) target sequence and a phospho-serine/threonine-binding domain, FHA2, derived from yeast Rad53. Phosphorylation of the serine residue within the target sequence by ATM would lead to its interaction with the phospho-serine-binding domain, thereby preventing complementation of the split luciferase pair and loss of reporter activity. Bioluminescence imaging of reporter expressing cells in cultured plates or as mouse xenografts provides a quantitative surrogate for ATM kinase activity and therefore the cellular DNA damage response in a noninvasive, dynamic fashion.

Development of an image processing system at the Technology Applications Center, UNM: Landsat image processing in mineral exploration and related activities. Final report

International Nuclear Information System (INIS)

Budge, T.K.

1980-09-01

This project was a demonstration of the capabilities of Landsat satellite image processing applied to the monitoring of mining activity in New Mexico. Study areas included the Navajo coal surface mine, the Jackpile uranium surface mine, and the potash mining district near Carlsbad, New Mexico. Computer classifications of a number of land use categories in these mines were presented and discussed. A literature review of a number of case studies concerning the use of Landsat image processing in mineral exploration and related activities was prepared. Included in this review is a discussion of the Landsat satellite system and the basics of computer image processing. Topics such as destriping, contrast stretches, atmospheric corrections, ratioing, and classification techniques are addressed. Summaries of the STANSORT II and ELAS software packages and the Technology Application Center's Digital Image Processing System (TDIPS) are presented

Developing standard transmission system for radiology reporting including key images

International Nuclear Information System (INIS)

Kim, Seon Chil

2007-01-01

Development of hospital information system and Picture Archiving Communication System is not new in the medical field, and the development of internet and information technology are also universal. In the course of such development, however, it is hard to share medical information without a refined standard format. Especially in the department of radiology, the role of PACS has become very important in interchanging information with other disparate hospital information systems. A specific system needs to be developed that radiological reports are archived into a database efficiently. This includes sharing of medical images. A model is suggested in this study in which an internal system is developed where radiologists store necessary images and transmit them is the standard international clinical format, Clinical Document Architecture, and share the information with hospitals. CDA document generator was made to generate a new file format and separate the existing storage system from the new system. This was to ensure the access to required data in XML documents. The model presented in this study added a process where crucial images in reading are inserted in the CDA radiological report generator. Therefore, this study suggests a storage and transmission model for CDA documents, which is different from the existing DICOM SR. Radiological reports could be better shared, when the application function for inserting images and the analysis of standard clinical terms are completed

Pediatric littoral cell angioma of the spleen: multimodality imaging including diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Ertan, Gulhan; Tekes, Aylin; Huisman, Thierry A.G.M. [Johns Hopkins Hospital, Division of Pediatric Radiology, Department of Radiology and Radiological Science, Baltimore, MD (United States); Mitchell, Sally [Johns Hopkins Hospital, Division of Cardiovascular and Interventional Radiology, Department of Radiology and Radiological Science, Baltimore (United States); Keefer, Jeffrey [Johns Hopkins Hospital, Division of Pediatric Hematology, Department of Pediatrics, Baltimore, MD (United States)

2009-10-15

Littoral cell angioma (LCA) is a rare primary splenic vascular tumor originating from littoral cells lining the splenic red pulp sinuses. LCAs are rarely seen in children. We present the US, CT, and MRI findings including diffusion-weighted imaging (DWI) in a 2-year-old boy with histologically proven LCA. Previous studies on liver lesions have shown that DWI allows differentiation of vascular tumors from primary neoplasms and metastatic disease. The current case indicates that increased ADC values within the splenic lesions suggest a vascular etiology, which might help narrow the differential diagnosis. (orig.)

Pediatric littoral cell angioma of the spleen: multimodality imaging including diffusion-weighted imaging

International Nuclear Information System (INIS)

Ertan, Gulhan; Tekes, Aylin; Huisman, Thierry A.G.M.; Mitchell, Sally; Keefer, Jeffrey

2009-01-01

Littoral cell angioma (LCA) is a rare primary splenic vascular tumor originating from littoral cells lining the splenic red pulp sinuses. LCAs are rarely seen in children. We present the US, CT, and MRI findings including diffusion-weighted imaging (DWI) in a 2-year-old boy with histologically proven LCA. Previous studies on liver lesions have shown that DWI allows differentiation of vascular tumors from primary neoplasms and metastatic disease. The current case indicates that increased ADC values within the splenic lesions suggest a vascular etiology, which might help narrow the differential diagnosis. (orig.)

Active learning methods for interactive image retrieval.

Science.gov (United States)

Gosselin, Philippe Henri; Cord, Matthieu

2008-07-01

Active learning methods have been considered with increased interest in the statistical learning community. Initially developed within a classification framework, a lot of extensions are now being proposed to handle multimedia applications. This paper provides algorithms within a statistical framework to extend active learning for online content-based image retrieval (CBIR). The classification framework is presented with experiments to compare several powerful classification techniques in this information retrieval context. Focusing on interactive methods, active learning strategy is then described. The limitations of this approach for CBIR are emphasized before presenting our new active selection process RETIN. First, as any active method is sensitive to the boundary estimation between classes, the RETIN strategy carries out a boundary correction to make the retrieval process more robust. Second, the criterion of generalization error to optimize the active learning selection is modified to better represent the CBIR objective of database ranking. Third, a batch processing of images is proposed. Our strategy leads to a fast and efficient active learning scheme to retrieve sets of online images (query concept). Experiments on large databases show that the RETIN method performs well in comparison to several other active strategies.

Large-scale imaging of retinal output activity

CERN Document Server

Litke, A M; Dabrowski, W; Grillo, A A; Grybos, P; Kachiguine, S; Rahman, M; Taylor, G

2003-01-01

A system is being developed to study how the retina processes, encodes and communicates information about the visual world to the brain. It will image the activity of retinal output neurons over a region of live retina approaching that used for significant neural computation in the visual cortex. A prototype system consisting of 61 microelectrodes, covering an area of 0.17 mm**2, is described, including some first results with monkey retina. The plans and status for a system with 512 microelectrodes, covering an area of 1.7 mm**2, are also given.

Active spectral imaging nondestructive evaluation (SINDE) camera

Energy Technology Data Exchange (ETDEWEB)

Simova, E.; Rochefort, P.A., E-mail: eli.simova@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

2016-06-15

A proof-of-concept video camera for active spectral imaging nondestructive evaluation has been demonstrated. An active multispectral imaging technique has been implemented in the visible and near infrared by using light emitting diodes with wavelengths spanning from 400 to 970 nm. This shows how the camera can be used in nondestructive evaluation to inspect surfaces and spectrally identify materials and corrosion. (author)

The fiber-optic imaging and manipulation of neural activity during animal behavior.

Science.gov (United States)

Miyamoto, Daisuke; Murayama, Masanori

2016-02-01

Recent progress with optogenetic probes for imaging and manipulating neural activity has further increased the relevance of fiber-optic systems for neural circuitry research. Optical fibers, which bi-directionally transmit light between separate sites (even at a distance of several meters), can be used for either optical imaging or manipulating neural activity relevant to behavioral circuitry mechanisms. The method's flexibility and the specifications of the light structure are well suited for following the behavior of freely moving animals. Furthermore, thin optical fibers allow researchers to monitor neural activity from not only the cortical surface but also deep brain regions, including the hippocampus and amygdala. Such regions are difficult to target with two-photon microscopes. Optogenetic manipulation of neural activity with an optical fiber has the advantage of being selective for both cell-types and projections as compared to conventional electrophysiological brain tissue stimulation. It is difficult to extract any data regarding changes in neural activity solely from a fiber-optic manipulation device; however, the readout of data is made possible by combining manipulation with electrophysiological recording, or the simultaneous application of optical imaging and manipulation using a bundle-fiber. The present review introduces recent progress in fiber-optic imaging and manipulation methods, while also discussing fiber-optic system designs that are suitable for a given experimental protocol. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Magnetic resonance imaging of epidermoid, including diffusion weighted images and an atypical case

International Nuclear Information System (INIS)

Takahashi, Shoki; Higano, Shuichi; Kurihara, Noriko

1994-01-01

In order to study the role of magnetic resonance imaging (MRI) in diagnosing intracranial epidermoid, we evaluated the MRI findings on five cases with such tumor, all of which were surgically verified. In addition to standard spin-echo (SE) images obtained in all cases, diffusion-weighted images were acquired in two patients. In four patients, the tumor revealed to be almost isointense relative to cerebrospinal fluid (CSF) on both T 1 -and T 2 -weighted images, while it tended to show slightly hyperintense to CSF on proton-density-weighted images; thus, based on the signal intensity on standard SE images the distinction between epidermoid and arachnoid cyst may be difficult. Furthermore, the presence of the tumor which has a tendency to grow in and along the subarachnoid space causing relatively minimal mass effect may be overlooked. Diffusion-weighted images were shown to have advantages in such cases by demonstrating the tumor unequivocally as a mass of high signal, and differentiating it from arachnoid cysts. In the remaining patient, its appearance was atypical, showing bright signal on both T 1 -and T 2 -weighted images. In conclusion free of bone artifacts, multiplanar MRI with additional diffusion-weighted images provides a clear demonstration of epidermoid, and its differentiation from arachnoid cyst, thus obviating the need for CT cisternography. (author)

Gender differences in brain activity generated by unpleasant word stimuli concerning body image: an fMRI study.

Science.gov (United States)

Shirao, Naoko; Okamoto, Yasumasa; Mantani, Tomoyuki; Okamoto, Yuri; Yamawaki, Shigeto

2005-01-01

We have previously reported that the temporomesial area, including the amygdala, is activated in women when processing unpleasant words concerning body image. To detect gender differences in brain activation during processing of these words. Functional magnetic resonance imaging was used to investigate 13 men and 13 women during an emotional decision task consisting of unpleasant words concerning body image and neutral words. The left medial prefrontal cortex and hippocampus were activated only among men, and the left amygdala was activated only among women during the task; activation in the apical prefrontal region was significantly greater in men than in women. Our data suggest that the prefrontal region is responsible for the gender differences in the processing of words concerning body image, and may also be responsible for gender differences in susceptibility to eating disorders.

Role of 3.0 T MR vessel wall imaging for identifying the activity of takayasu arteritis

International Nuclear Information System (INIS)

Liu Xiaosheng; Xu Jianrong; Zhao Huilin; Cheng Fang; Lu Qing; Yao Qiuying

2010-01-01

Objective: To analyze and explore the value of 3 T high resolution magnetic resonance vessel wall imaging for identifying the activity of Takayasu arteritis. Methods: Twenty-six consecutive patients with Takayasu arteritis underwent 3.0 T high resolution MR vessel wall imaging on supraortic vessels (according to the classification of Lupi-Herrea, type I and III were included). Sixteen patients were in active phase and 10 in inactive phase based on the Kerr criteria. The MR vessel wall imaging appearances of Takayasu arteritis were compared between the active phase and inactive phase cases. Results: Wall thickening was demonstrated in all involved arteries. There were statistically significant differences between active phase and inactive phase cases in MR appearances including multi-ring thickening of vessel wall (75/80 and 18/50), arterial inner wail enhancement (50/80 and 19/50), obscurity of perivascular fat (55/80 and 18/50, X 2 =50.39, 7.41, 13.40, P<0.01). There was also a statistically significant difference in the thickness of carotid artery wall between the two groups [ (3.8 ± 0.2) mm vs (2.5 ± 0.8) mm]. Conclusion: 3 T high resolution MR vessel wall imaging is valuable for identifying the activity of Takayasu arteritis. (authors)

Sequential Magnetic Resonance Imaging Finding of Intramedullary Spinal Cord Abscess including Diffusion Weighted Image: a Case Report

Energy Technology Data Exchange (ETDEWEB)

Roh, Jae Eun; Lee, Seung Young; Cha, Sang Hoon; Cho, Bum Sang; Jeon, Min Hee; Kang, Min Ho [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of)

2011-04-15

Intramedullary spinal cord abscess (ISCA) is a rare infection of the central nervous system. We describe the magnetic resonance imaging (MRI) findings, including the diffusion-weighted imaging (DWI) findings, of ISCA in a 78-year-old man. The initial conventional MRI of the thoracic spine demonstrated a subtle enhancing nodule accompanied by significant edema. On the follow-up MRI after seven days, the nodule appeared as a ring-enhancing nodule. The non-enhancing central portion of the nodule appeared hyperintense on DWI with a decreased apparent diffusion coefficient (ADC) value on the ADC map. We performed myelotomy and surgical drainage, and thick, yellowish pus was drained

Imaging of Prostate Cancer Using Urokinase-Type Plasminogen Activator Receptor PET

DEFF Research Database (Denmark)

Skovgaard, Dorthe; Persson, Morten; Kjaer, Andreas

2017-01-01

Urokinase-type plasminogen activator receptor (uPAR) overexpression is an important biomarker for aggressiveness in cancer including prostate cancer (PC) and provides independent clinical information in addition to prostate-specific antigen and Gleason score. This article focuses on uPAR PET...... as a new diagnostic and prognostic imaging biomarker in PC. Many preclinical uPAR-targeted PET imaging studies using AE105 in cancer models have been undertaken with promising results. A major breakthrough was obtained with the recent human translation of uPAR PET in using 64Cu- and 68Ga-labelled versions...

Visual image reconstruction from human brain activity: A modular decoding approach

International Nuclear Information System (INIS)

Miyawaki, Yoichi; Uchida, Hajime; Yamashita, Okito; Sato, Masa-aki; Kamitani, Yukiyasu; Morito, Yusuke; Tanabe, Hiroki C; Sadato, Norihiro

2009-01-01

Brain activity represents our perceptual experience. But the potential for reading out perceptual contents from human brain activity has not been fully explored. In this study, we demonstrate constraint-free reconstruction of visual images perceived by a subject, from the brain activity pattern. We reconstructed visual images by combining local image bases with multiple scales, whose contrasts were independently decoded from fMRI activity by automatically selecting relevant voxels and exploiting their correlated patterns. Binary-contrast, 10 x 10-patch images (2 100 possible states), were accurately reconstructed without any image prior by measuring brain activity only for several hundred random images. The results suggest that our approach provides an effective means to read out complex perceptual states from brain activity while discovering information representation in multi-voxel patterns.

Major depressive disorder is characterized by greater reward network activation to monetary than pleasant image rewards.

Science.gov (United States)

Smoski, Moria J; Rittenberg, Alison; Dichter, Gabriel S

2011-12-30

Anhedonia, the loss of interest or pleasure in normally rewarding activities, is a hallmark feature of unipolar Major Depressive Disorder (MDD). A growing body of literature has identified frontostriatal dysfunction during reward anticipation and outcomes in MDD. However, no study to date has directly compared responses to different types of rewards such as pleasant images and monetary rewards in MDD. To investigate the neural responses to monetary and pleasant image rewards in MDD, a modified Monetary Incentive Delay task was used during functional magnetic resonance imaging to assess neural responses during anticipation and receipt of monetary and pleasant image rewards. Participants included nine adults with MDD and 13 affectively healthy controls. The MDD group showed lower activation than controls when anticipating monetary rewards in right orbitofrontal cortex and subcallosal cortex, and when anticipating pleasant image rewards in paracingulate and supplementary motor cortex. The MDD group had relatively greater activation in right putamen when anticipating monetary versus pleasant image rewards, relative to the control group. Results suggest reduced reward network activation in MDD when anticipating rewards, as well as relatively greater hypoactivation to pleasant image than monetary rewards. 2011 Elsevier Ireland Ltd. All rights reserved.

Method and apparatus for enhanced sensitivity filmless medical x-ray imaging, including three-dimensional imaging

Science.gov (United States)

Parker, Sherwood

1995-01-01

A filmless X-ray imaging system includes at least one X-ray source, upper and lower collimators, and a solid-state detector array, and can provide three-dimensional imaging capability. The X-ray source plane is distance z.sub.1 above upper collimator plane, distance z.sub.2 above the lower collimator plane, and distance z.sub.3 above the plane of the detector array. The object to be X-rayed is located between the upper and lower collimator planes. The upper and lower collimators and the detector array are moved horizontally with scanning velocities v.sub.1, v.sub.2, v.sub.3 proportional to z.sub.1, z.sub.2 and z.sub.3, respectively. The pattern and size of openings in the collimators, and between detector positions is proportional such that similar triangles are always defined relative to the location of the X-ray source. X-rays that pass through openings in the upper collimator will always pass through corresponding and similar openings in the lower collimator, and thence to a corresponding detector in the underlying detector array. Substantially 100% of the X-rays irradiating the object (and neither absorbed nor scattered) pass through the lower collimator openings and are detected, which promotes enhanced sensitivity. A computer system coordinates repositioning of the collimators and detector array, and X-ray source locations. The computer system can store detector array output, and can associate a known X-ray source location with detector array output data, to provide three-dimensional imaging. Detector output may be viewed instantly, stored digitally, and/or transmitted electronically for image viewing at a remote site.

Activating Attachments Reduces Memories of Traumatic Images.

Directory of Open Access Journals (Sweden)

Richard A Bryant

Full Text Available Emotional memories, and especially intrusive memories, are a common feature of many psychological disorders, and are overconsolidated by stress. Attachment theory posits that activation of mental representations of attachment figures can reduce stress and boost coping. This study tested the proposition that attachment activation would reduce consolidation of emotional and intrusive memories. Sixty-seven undergraduate students viewed subliminal presentations of traumatic and neutral images, which were preceded by subliminal presentations of either attachment-related images or non-attachment-related images; free recall and intrusive memories were assessed two days later. Participants with low avoidant attachment tendencies who received the attachment primes recalled fewer memories and reported fewer intrusions than those who received the non-attachment primes. Unexpectedly, those with high anxious attachment tendencies reported fewer memories. These findings generally accord with attachment theory, and suggest that consolidation of emotional memories can be moderated by activation of attachment representations.

An asynchronous, pipelined, electronic acquisition system for Active Matrix Flat-Panel Imagers (AMFPIs)

Energy Technology Data Exchange (ETDEWEB)

Huang, W.; Antonuk, L.E. E-mail: antonuk@umich.edu; Berry, J.; Maolinbay, M.; Martelli, C.; Mody, P.; Nassif, S.; Yeakey, M

1999-07-11

The development of a full-custom electronic acquisition system designed for readout of large-area active matrix flat-panel imaging arrays is reported. The arrays, which comprise two-dimensional matrices of pixels utilizing amorphous silicon thin-film transistors, are themselves under development for a wide variety of X-ray imaging applications. The acquisition system was specifically designed to facilitate detailed, quantitative investigations of the properties of these novel imaging arrays and contains significant enhancements compared to a previously developed acquisition system. These enhancements include pipelined preamplifier circuits to allow faster readout speed, expanded addressing capabilities allowing a maximum of 4096 array data lines, and on-board summing of image frames. The values of many acquisition system parameters, including timings and voltages, may be specified and downloaded from a host computer. Once acquisition is enabled, the system operates asynchronously of its host computer. The system allows image capture in both radiographic mode (corresponding to the capture of individual X-ray images), and fluoroscopic mode (corresponding to the capture of a continual series of X-ray images). A detailed description of the system architecture and the underlying motivations for the design is reported in this paper. (author)

An asynchronous, pipelined, electronic acquisition system for Active Matrix Flat-Panel Imagers (AMFPIs)

CERN Document Server

Huang, W; Berry, J; Maolinbay, M; Martelli, C; Mody, P; Nassif, S; Yeakey, M

1999-01-01

The development of a full-custom electronic acquisition system designed for readout of large-area active matrix flat-panel imaging arrays is reported. The arrays, which comprise two-dimensional matrices of pixels utilizing amorphous silicon thin-film transistors, are themselves under development for a wide variety of X-ray imaging applications. The acquisition system was specifically designed to facilitate detailed, quantitative investigations of the properties of these novel imaging arrays and contains significant enhancements compared to a previously developed acquisition system. These enhancements include pipelined preamplifier circuits to allow faster readout speed, expanded addressing capabilities allowing a maximum of 4096 array data lines, and on-board summing of image frames. The values of many acquisition system parameters, including timings and voltages, may be specified and downloaded from a host computer. Once acquisition is enabled, the system operates asynchronously of its host computer. The sys...

Simulating Galaxies and Active Galactic Nuclei in the LSST Image Simulation Effort

NARCIS (Netherlands)

Pizagno II, Jim; Ahmad, Z.; Bankert, J.; Bard, D.; Connolly, A.; Chang, C.; Gibson, R. R.; Gilmore, K.; Grace, E.; Hannel, M.; Jernigan, J. G.; Jones, L.; Kahn, S. M.; Krughoff, S. K.; Lorenz, S.; Marshall, S.; Shmakova, S. M.; Sylvestri, N.; Todd, N.; Young, M.

We present an extragalactic source catalog, which includes galaxies and Active Galactic Nuclei, that is used for the Large Survey Synoptic Telescope Imaging Simulation effort. The galaxies are taken from the De Lucia et. al. (2006) semi-analytic modeling (SAM) of the Millennium Simulation. The LSST

Submillimeter Confocal Imaging Active Module

Science.gov (United States)

Hong, John; Mehdi, Imran; Siegel, Peter; Chattopadhyay, Goutam; Cwik, Thomas; Rowell, Mark; Hacker, John

2009-01-01

The term submillimeter confocal imaging active module (SCIAM) denotes a proposed airborne coherent imaging radar system that would be suitable for use in reconnaissance, surveillance, and navigation. The development of the SCIAM would include utilization and extension of recent achievements in monolithic microwave integrated circuits capable of operating at frequencies up to and beyond a nominal radio frequency of 340 GHz. Because the SCIAM would be primarily down-looking (in contradistinction to primarily side-looking), it could be useful for imaging shorter objects located between taller ones (for example, objects on streets between buildings). The SCIAM would utilize a confocal geometry to obtain high cross-track resolution, and would be amenable to synthetic-aperture processing of its output to obtain high along-track resolution. The SCIAM (see figure) would include multiple (two in the initial version) antenna apertures, separated from each other by a cross-track baseline of suitable length (e.g., 1.6 m). These apertures would both transmit the illuminating radar pulses and receive the returns. A common reference oscillator would generate a signal at a controllable frequency of (340 GHz + (Delta)f)/N, where (Delta)f is an instantaneous swept frequency difference and N is an integer. The output of this oscillator would be fed to a frequency- multiplier-and-power-amplifier module to obtain a signal, at 340 GHz + (Delta)f, that would serve as both the carrier signal for generating the transmitted pulses and a local-oscillator (LO) signal for a receiver associated with each antenna aperture. Because duplexers in the form of circulators or transmit/receive (T/R) switches would be lossy and extremely difficult to implement, the antenna apertures would be designed according to a spatial-diplexing scheme, in which signals would be coupled in and out via separate, adjacent transmitting and receiving feed horns. This scheme would cause the transmitted and received beams

The relationship between functional magnetic resonance imaging activation, diffusion tensor imaging, and training effects.

Science.gov (United States)

Farrar, Danielle; Budson, Andrew E

2017-04-01

While the relationship between diffusion tensor imaging (DTI) measurements and training effects is explored by Voelker et al. (this issue), a cursory discussion of functional magnetic resonance imaging (fMRI) measurements categorizes increased activation with findings of greater white matter integrity. Evidence of the relationship between fMRI activation and white matter integrity is conflicting, as is the relationship between fMRI activation and training effects. An examination of the changes in fMRI activation in response to training is helpful, but the relationship between DTI and fMRI activation, particularly in the context of white matter changes, must be examined further before general conclusions can be drawn.

Body Image and quality of life of senior citizens included in a cardiac rehabilitation program

Directory of Open Access Journals (Sweden)

Fernanda Vargas Amaral

2013-12-01

Full Text Available Most people who have to live with some kind of disease tend to adopt healthy habits and create new ways of seeing themselves. The aim of this study is to explore the relationship between the index of quality of life and self perception of patients included in a cardiovascular rehabilitation program in Florianopolis/Brazil. The sample consists of 24 subjects of 62 ± 1.3 years of age, who have coronary artery disease. The Minnesota Living With Heart Failure Questionnaire (MLHFQ was used to assess the quality of life, and to identify the degree of body image discontentment the Stunkard and Sorensen questionnaire (1993 was applied. Statistical analysis was made through statistics programs and the software SPSS 11.0. The degree of association between variables was studied with Kendall test. It was verified that the higher the BMI and the current body shape, the greatest the degree of body image dissatisfaction. The emotional symptoms also appear to be significantly correlated with a desire for a smaller body shape and with indicators of lower quality of life (r = 0474 = 0735, p major 0.05. The physical symptoms were also considerably associated with the emotional symptoms. These results suggest that the variables concerning the quality of life are meaningful to significant body image and satisfaction, which seems to correlate with fewer emotional problems and better facing of the disease. Cardiovascular Rehabilitation Programs that implement physical activity in daily habits proves to be a suitable tool for improving these ailments in this post-acute phase

Active gated imaging in driver assistance system

Science.gov (United States)

Grauer, Yoav

2014-04-01

In this paper, we shall present the active gated imaging system (AGIS) in relation to the automotive field. AGIS is based on a fast-gated camera and pulsed illuminator, synchronized in the time domain to record images of a certain range of interest. A dedicated gated CMOS imager sensor and near infra-red (NIR) pulsed laser illuminator, is presented in this paper to provide active gated technology. In recent years, we have developed these key components and learned the system parameters, which are most beneficial to nighttime (in all weather conditions) driving in terms of field of view, illumination profile, resolution, and processing power. We shall present our approach of a camera-based advanced driver assistance systems (ADAS) named BrightEye™, which makes use of the AGIS technology in the automotive field.

Imaging of glia activation in people with primary lateral sclerosis.

Science.gov (United States)

Paganoni, Sabrina; Alshikho, Mohamad J; Zürcher, Nicole R; Cernasov, Paul; Babu, Suma; Loggia, Marco L; Chan, James; Chonde, Daniel B; Garcia, David Izquierdo; Catana, Ciprian; Mainero, Caterina; Rosen, Bruce R; Cudkowicz, Merit E; Hooker, Jacob M; Atassi, Nazem

2018-01-01

Glia activation is thought to contribute to neuronal damage in several neurodegenerative diseases based on preclinical and human post - mortem studies, but its role in primary lateral sclerosis (PLS) is unknown. To localize and measure glia activation in people with PLS compared to healthy controls (HC). Ten participants with PLS and ten age-matched HCs underwent simultaneous magnetic resonance (MR) and proton emission tomography (PET). The radiotracer [ 11 C]-PBR28 was used to obtain PET-based measures of 18 kDa translocator protein (TSPO) expression, a marker of activated glial cells. MR techniques included a structural sequence to measure cortical thickness and diffusion tensor imaging (DTI) to assess white matter integrity. PET data showed increased [ 11 C]-PBR28 uptake in anatomically-relevant motor regions which co-localized with areas of regional gray matter atrophy and decreased subcortical fractional anisotropy. This study supports a link between glia activation and neuronal degeneration in PLS, and suggests that these disease mechanisms can be measured in vivo in PLS. Future studies are needed to determine the longitudinal changes of these imaging measures and to clarify if MR-PET with [ 11 C]-PBR28 can be used as a biomarker for drug development in the context of clinical trials for PLS.

Physiological basis and image processing in functional magnetic resonance imaging: Neuronal and motor activity in brain

Directory of Open Access Journals (Sweden)

Sharma Rakesh

2004-05-01

Full Text Available Abstract Functional magnetic resonance imaging (fMRI is recently developing as imaging modality used for mapping hemodynamics of neuronal and motor event related tissue blood oxygen level dependence (BOLD in terms of brain activation. Image processing is performed by segmentation and registration methods. Segmentation algorithms provide brain surface-based analysis, automated anatomical labeling of cortical fields in magnetic resonance data sets based on oxygen metabolic state. Registration algorithms provide geometric features using two or more imaging modalities to assure clinically useful neuronal and motor information of brain activation. This review article summarizes the physiological basis of fMRI signal, its origin, contrast enhancement, physical factors, anatomical labeling by segmentation, registration approaches with examples of visual and motor activity in brain. Latest developments are reviewed for clinical applications of fMRI along with other different neurophysiological and imaging modalities.

A 128 x 128 CMOS Active Pixel Image Sensor for Highly Integrated Imaging Systems

Science.gov (United States)

Mendis, Sunetra K.; Kemeny, Sabrina E.; Fossum, Eric R.

1993-01-01

A new CMOS-based image sensor that is intrinsically compatible with on-chip CMOS circuitry is reported. The new CMOS active pixel image sensor achieves low noise, high sensitivity, X-Y addressability, and has simple timing requirements. The image sensor was fabricated using a 2 micrometer p-well CMOS process, and consists of a 128 x 128 array of 40 micrometer x 40 micrometer pixels. The CMOS image sensor technology enables highly integrated smart image sensors, and makes the design, incorporation and fabrication of such sensors widely accessible to the integrated circuit community.

NSCT BASED LOCAL ENHANCEMENT FOR ACTIVE CONTOUR BASED IMAGE SEGMENTATION APPLICATION

Directory of Open Access Journals (Sweden)

Hiren Mewada

2010-08-01

Full Text Available Because of cross-disciplinary nature, Active Contour modeling techniques have been utilized extensively for the image segmentation. In traditional active contour based segmentation techniques based on level set methods, the energy functions are defined based on the intensity gradient. This makes them highly sensitive to the situation where the underlying image content is characterized by image nonhomogeneities due to illumination and contrast condition. This is the most difficult problem to make them as fully automatic image segmentation techniques. This paper introduces one of the approaches based on image enhancement to this problem. The enhanced image is obtained using NonSubsampled Contourlet Transform, which improves the edges strengths in the direction where the illumination is not proper and then active contour model based on level set technique is utilized to segment the object. Experiment results demonstrate that proposed method can be utilized along with existing active contour model based segmentation method under situation characterized by intensity non-homogeneity to make them fully automatic.

Dual-source dual-energy CT angiography with virtual non-enhanced images and iodine map for active gastrointestinal bleeding: Image quality, radiation dose and diagnostic performance

International Nuclear Information System (INIS)

Sun, Hao; Hou, Xin-Yi; Xue, Hua-Dan; Li, Xiao-Guang; Jin, Zheng-Yu; Qian, Jia-Ming; Yu, Jian-Chun; Zhu, Hua-Dong

2015-01-01

Highlights: • GIB is a common gastrointestinal emergency with a high mortality rate. • Detection and localization of GIB source are important for imaging modality. • DSDECTA using a dual-phase scan protocol is clinically feasible. • DSDECTA with VNE and iodine map images can diagnose the active GIB source accurately. • DSDECTA can reduce radiation dose compared with conventional CT examination in GIB. - Abstract: Objectives: To evaluate the clinical feasibility of dual-source dual-energy CT angiography (DSDECTA) with virtual non-enhanced images and iodine map for active gastrointestinal bleeding (GIB). Methods: From June 2010 to December 2012, 112 consecutive patients with clinical signs of active GIB underwent DSDECTA with true non-enhanced (TNE), arterial phase with single-source mode, and portal-venous phase with dual-energy mode (100 kVp/230 mAs and Sn 140 kVp/178 mAs). Virtual non-enhanced CT (VNE) image sets and iodine map were reformatted from ‘Liver VNC’ software. The mean CT number, noise, signal to noise ratio (SNR), image quality and radiation dose were compared between TNE and VNE image sets. Two radiologists, blinded to clinical data, interpreted images from DSDECTA with TNE (protocol 1), and DSDECTA with VNE and iodine map (protocol 2) respectively, with discordant interpretation resolved by consensus. The standards of reference included digital subtraction angiography, endoscopy, surgery, or final pathology reports. Receiver–operating characteristic (ROC) analysis was undertaken and the area under the curve (AUC) calculated for CT protocols 1 and 2, respectively. Results: There was no significant difference in mean CT numbers of all organs (including liver, pancreas, spleen, kidney, abdominal aorta, and psoas muscle) (P > 0.05). Lower noise and higher SNR were found on VNE images than TNE images (P < 0.05). Image quality of VNE was lower than that of TNE without significant difference (P > 0.05). The active GIB source was identified

Dual-source dual-energy CT angiography with virtual non-enhanced images and iodine map for active gastrointestinal bleeding: Image quality, radiation dose and diagnostic performance

Energy Technology Data Exchange (ETDEWEB)

Sun, Hao, E-mail: sunhao_robert@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Hou, Xin-Yi, E-mail: hxy_pumc@126.com [Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing (China); Xue, Hua-Dan, E-mail: bjdanna95@hotmail.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Li, Xiao-Guang, E-mail: xglee88@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Jin, Zheng-Yu, E-mail: zhengyu_jin@126.com [Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Wangfujing Street, Dongcheng District, Beijing 100730 (China); Qian, Jia-Ming, E-mail: qjiaming57@gmail.com [Department of Gastroenterology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China); Yu, Jian-Chun, E-mail: yu-jch@163.com [Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China); Zhu, Hua-Dong, E-mail: huadongzhu@hotmail.com [Department of Emergency, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing (China)

2015-05-15

Highlights: • GIB is a common gastrointestinal emergency with a high mortality rate. • Detection and localization of GIB source are important for imaging modality. • DSDECTA using a dual-phase scan protocol is clinically feasible. • DSDECTA with VNE and iodine map images can diagnose the active GIB source accurately. • DSDECTA can reduce radiation dose compared with conventional CT examination in GIB. - Abstract: Objectives: To evaluate the clinical feasibility of dual-source dual-energy CT angiography (DSDECTA) with virtual non-enhanced images and iodine map for active gastrointestinal bleeding (GIB). Methods: From June 2010 to December 2012, 112 consecutive patients with clinical signs of active GIB underwent DSDECTA with true non-enhanced (TNE), arterial phase with single-source mode, and portal-venous phase with dual-energy mode (100 kVp/230 mAs and Sn 140 kVp/178 mAs). Virtual non-enhanced CT (VNE) image sets and iodine map were reformatted from ‘Liver VNC’ software. The mean CT number, noise, signal to noise ratio (SNR), image quality and radiation dose were compared between TNE and VNE image sets. Two radiologists, blinded to clinical data, interpreted images from DSDECTA with TNE (protocol 1), and DSDECTA with VNE and iodine map (protocol 2) respectively, with discordant interpretation resolved by consensus. The standards of reference included digital subtraction angiography, endoscopy, surgery, or final pathology reports. Receiver–operating characteristic (ROC) analysis was undertaken and the area under the curve (AUC) calculated for CT protocols 1 and 2, respectively. Results: There was no significant difference in mean CT numbers of all organs (including liver, pancreas, spleen, kidney, abdominal aorta, and psoas muscle) (P > 0.05). Lower noise and higher SNR were found on VNE images than TNE images (P < 0.05). Image quality of VNE was lower than that of TNE without significant difference (P > 0.05). The active GIB source was identified

Body image dissatisfaction, physical activity and screen-time in Spanish adolescents.

Science.gov (United States)

Añez, Elizabeth; Fornieles-Deu, Albert; Fauquet-Ars, Jordi; López-Guimerà, Gemma; Puntí-Vidal, Joaquim; Sánchez-Carracedo, David

2018-01-01

This cross-sectional study contributes to the literature on whether body dissatisfaction is a barrier/facilitator to engaging in physical activity and to investigate the impact of mass-media messages via computer-time on body dissatisfaction. High-school students ( N = 1501) reported their physical activity, computer-time (homework/leisure) and body dissatisfaction. Researchers measured students' weight and height. Analyses revealed that body dissatisfaction was negatively associated with physical activity on both genders, whereas computer-time was associated only with girls' body dissatisfaction. Specifically, as computer-homework increased, body dissatisfaction decreased; as computer-leisure increased, body dissatisfaction increased. Weight-related interventions should improve body image and physical activity simultaneously, while critical consumption of mass-media interventions should include a computer component.

Can We Include The Third Dimension During Image Mining?

Indian Academy of Sciences (India)

Retrieved images using only photometric features · Use of X-ratio · Results for a different query · Retrieval results with geometric and photometric features · Rail track retrieval · Recall and Precision · Retrieval Performance · Application II: Search Arts and Sports Photography · Examples of low DOF images · Typical Retrieval.

Active mask segmentation of fluorescence microscope images.

Science.gov (United States)

Srinivasa, Gowri; Fickus, Matthew C; Guo, Yusong; Linstedt, Adam D; Kovacević, Jelena

2009-08-01

We propose a new active mask algorithm for the segmentation of fluorescence microscope images of punctate patterns. It combines the (a) flexibility offered by active-contour methods, (b) speed offered by multiresolution methods, (c) smoothing offered by multiscale methods, and (d) statistical modeling offered by region-growing methods into a fast and accurate segmentation tool. The framework moves from the idea of the "contour" to that of "inside and outside," or masks, allowing for easy multidimensional segmentation. It adapts to the topology of the image through the use of multiple masks. The algorithm is almost invariant under initialization, allowing for random initialization, and uses a few easily tunable parameters. Experiments show that the active mask algorithm matches the ground truth well and outperforms the algorithm widely used in fluorescence microscopy, seeded watershed, both qualitatively, as well as quantitatively.

A generalized model for optimal transport of images including dissipation and density modulation

KAUST Repository

Maas, Jan

2015-11-01

© EDP Sciences, SMAI 2015. In this paper the optimal transport and the metamorphosis perspectives are combined. For a pair of given input images geodesic paths in the space of images are defined as minimizers of a resulting path energy. To this end, the underlying Riemannian metric measures the rate of transport cost and the rate of viscous dissipation. Furthermore, the model is capable to deal with strongly varying image contrast and explicitly allows for sources and sinks in the transport equations which are incorporated in the metric related to the metamorphosis approach by Trouvé and Younes. In the non-viscous case with source term existence of geodesic paths is proven in the space of measures. The proposed model is explored on the range from merely optimal transport to strongly dissipative dynamics. For this model a robust and effective variational time discretization of geodesic paths is proposed. This requires to minimize a discrete path energy consisting of a sum of consecutive image matching functionals. These functionals are defined on corresponding pairs of intensity functions and on associated pairwise matching deformations. Existence of time discrete geodesics is demonstrated. Furthermore, a finite element implementation is proposed and applied to instructive test cases and to real images. In the non-viscous case this is compared to the algorithm proposed by Benamou and Brenier including a discretization of the source term. Finally, the model is generalized to define discrete weighted barycentres with applications to textures and objects.

Comparison of CT enterography and MR enterography imaging features of active Crohn disease in children and adolescents

Energy Technology Data Exchange (ETDEWEB)

Gale, Heather I. [The Warren Alpert Medical School of Brown University, Department of Diagnostic Imaging, Rhode Island Hospital/Hasbro Children' s Children' s Hospital/Women and Infants Hospital, Providence, RI (United States); Sharatz, Steven M.; Nimkin, Katherine; Gee, Michael S. [MassGeneral Hospital for Children, Division of Pediatric Imaging, Department of Radiology, Harvard Medical School, Boston, MA (United States); Taphey, Mayureewan [Bumrungrad International Hospital, Bangkok (Thailand); Bradley, William F. [Cambridge Mobile Telematics, Cambridge, MA (United States)

2017-09-15

Assessment for active Crohn disease by CT enterography and MR enterography relies on identifying mural and perienteric imaging features. To evaluate the performance of established imaging features of active Crohn disease in children and adolescents on CT and MR enterography compared with histological reference. We included patients ages 18 years and younger who underwent either CT or MR enterography from 2007 to 2014 and had endoscopic biopsy within 28 days of imaging. Two pediatric radiologists blinded to the histological results reviewed imaging studies and scored the bowel for the presence or absence of mural features (wall thickening >3 mm, mural hyperenhancement) and perienteric features (mesenteric hypervascularity, edema, fibrofatty proliferation and lymphadenopathy) of active disease. We performed univariate analysis and multivariate logistic regression to compare imaging features with histological reference. We evaluated 452 bowel segments (135 from CT enterography, 317 from MR enterography) from 84 patients. Mural imaging features had the highest association with active inflammation both for MR enterography (wall thickening had 80% accuracy, 69% sensitivity and 91% specificity; mural hyperenhancement had 78%, 53% and 96%, respectively) and CT enterography (wall thickening had 84% accuracy, 72% sensitivity and 91% specificity; mural hyperenhancement had 76%, 51% and 91%, respectively), with perienteric imaging features performing significantly worse on MR enterography relative to CT enterography (P < 0.001). Mural features are predictors of active inflammation for both CT and MR enterography, while perienteric features can be distinguished better on CT enterography compared with MR enterography. This likely reflects the increased conspicuity of the mesentery on CT enterography and suggests that mural features are the most reliable imaging features of active Crohn disease in children and adolescents. (orig.)

Automatic Image Segmentation Using Active Contours with Univariate Marginal Distribution

Directory of Open Access Journals (Sweden)

I. Cruz-Aceves

2013-01-01

Full Text Available This paper presents a novel automatic image segmentation method based on the theory of active contour models and estimation of distribution algorithms. The proposed method uses the univariate marginal distribution model to infer statistical dependencies between the control points on different active contours. These contours have been generated through an alignment process of reference shape priors, in order to increase the exploration and exploitation capabilities regarding different interactive segmentation techniques. This proposed method is applied in the segmentation of the hollow core in microscopic images of photonic crystal fibers and it is also used to segment the human heart and ventricular areas from datasets of computed tomography and magnetic resonance images, respectively. Moreover, to evaluate the performance of the medical image segmentations compared to regions outlined by experts, a set of similarity measures has been adopted. The experimental results suggest that the proposed image segmentation method outperforms the traditional active contour model and the interactive Tseng method in terms of segmentation accuracy and stability.

Multiple imaging mode X-ray computed tomography for distinguishing active and inactive phases in lithium-ion battery cathodes

Science.gov (United States)

Komini Babu, Siddharth; Mohamed, Alexander I.; Whitacre, Jay F.; Litster, Shawn

2015-06-01

This paper presents the use of nanometer scale resolution X-ray computed tomography (nano-CT) in the three-dimensional (3D) imaging of a Li-ion battery cathode, including the separate volumes of active material, binder plus conductive additive, and pore. The different high and low atomic number (Z) materials are distinguished by sequentially imaging the lithium cobalt oxide electrode in absorption and then Zernike phase contrast modes. Morphological parameters of the active material and the additives are extracted from the 3D reconstructions, including the distribution of contact areas between the additives and the active material. This method could provide a better understanding of the electric current distribution and structural integrity of battery electrodes, as well as provide detailed geometries for computational models.

My Body Looks Like That Girl's: Body Mass Index Modulates Brain Activity during Body Image Self-Reflection among Young Women.

Science.gov (United States)

Gao, Xiao; Deng, Xiao; Wen, Xin; She, Ying; Vinke, Petra Corianne; Chen, Hong

2016-01-01

Body image distress or body dissatisfaction is one of the most common consequences of obesity and overweight. We investigated the neural bases of body image processing in overweight and average weight young women to understand whether brain regions that were previously found to be involved in processing self-reflective, perspective and affective components of body image would show different activation between two groups. Thirteen overweight (O-W group, age = 20.31±1.70 years) and thirteen average weight (A-W group, age = 20.15±1.62 years) young women underwent functional magnetic resonance imaging while performing a body image self-reflection task. Among both groups, whole-brain analysis revealed activations of a brain network related to perceptive and affective components of body image processing. ROI analysis showed a main effect of group in ACC as well as a group by condition interaction within bilateral EBA, bilateral FBA, right IPL, bilateral DLPFC, left amygdala and left MPFC. For the A-W group, simple effect analysis revealed stronger activations in Thin-Control compared to Fat-Control condition within regions related to perceptive (including bilateral EBA, bilateral FBA, right IPL) and affective components of body image processing (including bilateral DLPFC, left amygdala), as well as self-reference (left MPFC). The O-W group only showed stronger activations in Fat-Control than in Thin-Control condition within regions related to the perceptive component of body image processing (including left EBA and left FBA). Path analysis showed that in the Fat-Thin contrast, body dissatisfaction completely mediated the group difference in brain response in left amygdala across the whole sample. Our data are the first to demonstrate differences in brain response to body pictures between average weight and overweight young females involved in a body image self-reflection task. These results provide insights for understanding the vulnerability to body image distress

Macroenvironmental factors including GDP per capita and physical activity in Europe.

Science.gov (United States)

Cameron, Adrian J; Van Stralen, Maartje M; Kunst, Anton E; Te Velde, Saskia J; Van Lenthe, Frank J; Salmon, Jo; Brug, Johannes

2013-02-01

Socioeconomic inequalities in physical activity at the individual level are well reported. Whether inequalities in economic development and other macroenvironmental variables between countries are also related to physical activity at the country level is comparatively unstudied. We examined the relationship between country-level data on macroenvironmental factors (gross domestic product (GDP) per capita, public sector expenditure on health, percentage living in urban areas, and cars per 1000 population) with country-level physical activity prevalence obtained from previous pan-European studies. Studies that assessed leisuretime physical activity (n = 3 studies including 27 countries in adults, n = 2 studies including 28 countries in children) and total physical activity (n = 3 studies in adults including 16 countries) were analyzed separately as were studies among adults and children. Strong and consistent positive correlations were observed between country prevalence of leisure-time physical activity and country GDP per capita in adults (average r = 0.70; all studies, P G 0.05). In multivariate analysis, country prevalence of leisure-time physical activity among adults remained associated with country GDP per capita (two of three studies) but not urbanization or educational attainment. Among school-age populations, no association was found between country GDP per capita and country prevalence of leisure-time physical activity. In those studies that assessed total physical activity (which also includes occupational and transport physical activity), no association with country GDP per capita was observed. Clear differences in national leisure-time physical activity levels throughout Europe may be a consequence of economic development. Lack of economic development of some countries in Europe may make increasing leisure-time physical activity more difficult. Further examination of the link between country GDP per capita and national physical activity levels (across

Multiple imaging procedures including MRI for the bladder cancer

International Nuclear Information System (INIS)

Mikata, Noriharu; Suzuki, Makoto; Takeuchi, Takumi; Kunisawa, Yositaka; Fukutani, Keiko; Kawabe, Kazuki

1986-01-01

Endoscopic photography, double contrast cystography, transurethral echography, X-ray CT scan, and MRI (magnetic resonance imaging) were utilized for the staging diagnosis of the four patients with carcinoma of the bladder. In the first case, a 70-year-old man, since all of the five imaging procedures suggested a superficial and pedunculated tumor, his bladder cancer was considered T1. The classification of stage T3 carcinoma was made for the second 86-year-old male. Because all of his imaging examinations showed a tumor infiltrating deep muscle and penetrating the bladder wall. The third case was a 36-year-old male. His clinical stage was diagnosed as T2 or T3a by cystophotography, double contrast cystogram, ultrasonography, and X-ray CT scan. However, MRI showed only thickened bladder wall and the infiltrating tumor could not be distinguished from the hypertrophic wall. The last patient, a 85-year-old female, had a smaller Ta cancer. Her double contrast cystography revealed the small tumor at the lateral bladder wall. But, the tumor could not be detected by transaxial, sagittal and coronal scans. Multiple imaging procedures combining MRI and staging diagnosis of the bladder carcinoma were discussed. (author)

Ratio Imaging of Enzyme Activity Using Dual Wavelength Optical Reporters

Directory of Open Access Journals (Sweden)

Moritz F. Kircher

2002-04-01

Full Text Available The design of near-infrared fluorescent (NIRF probes that are activated by specific proteases has, for the first time, allowed enzyme activity to be imaged in vivo. In the current study, we report on a method of imaging enzyme activity using two fluorescent probes that, together, provide improved quantitation of enzymatic activity. The method employs two chemically similar probes that differ in their degradability by cathepsin B. One probe consists of the NIRF dye Cy5.5 attached to a particulate carrier, a crosslinked iron oxide nanoparticle (CLIO, through cathepsin B cleavable l-arginyl peptides. A second probe consists of Cy3.5 attached to a CLIO through proteolytically resistant d-arginyl peptides. Using mixtures of the two probes, we have shown that the ratio of Cy5.5 to Cy3.5 fluorescence can be used to determine levels of cathepsin B in the environment of nanoparticles with macrophages in suspension. After intravenous injection, tissue fluorescence from the nondegradable Cy3.5–d-arginyl probe reflected nanoparticle accumulation, while fluorescence of the Cy5.5–l-arginyl probe was dependent on both accumulation and activation by cathepsin B. Dual wavelength ratio imaging can be used for the quantitative imaging of a variety of enzymes in clinically important settings, while the magnetic properties of the probes allow their detection by MR imaging.

Applicability of compton imaging in nuclear decommissioning activities

International Nuclear Information System (INIS)

Ljubenov, V.Lj.; Marinkovic, P.M.

2002-01-01

During the decommissioning of nuclear facilities significant part of the activities is related to the radiological characterization, waste classification and management. For these purposes a relatively new imaging technique, based on information from the gamma radiation that undergoes Compton scattering, is applicable. Compton imaging systems have a number of advantages for nuclear waste characterization, such as identifying hot spots in mixed waste in order to reduce the volume of high-level waste requiring extensive treatment or long-term storage, imaging large contaminated areas and objects etc. Compton imaging also has potential applications for monitoring of production, transport and storage of nuclear materials and components. This paper discusses some system design requirements and performance specifications for these applications. The advantages of Compton imaging are compared to competing imaging techniques. (author)

PET imaging of urokinase-type plasminogen activator receptor (uPAR) in prostate cancer

DEFF Research Database (Denmark)

Skovgaard, Dorthe; Persson, Morten; Kjaer, Andreas

2016-01-01

Overexpression of urokinase-type plasminogen activator receptors (uPAR) represents an important biomarker for aggressiveness in most common malignant diseases, including prostate cancer (PC). Accordingly, uPAR expression either assessed directly in malignant PC tissue or assessed directly in plasma...... and prognostic imaging method. In this review, we will focus on the recent development of uPAR PET and the relevance within prostate cancer imaging. Novel antibody and small-molecule radiotracers-targeting uPAR, including a series of uPAR-targeting PET ligands, based on the high affinity peptide ligand AE105......, have been synthesized and tested in vitro and in vivo in preclinical murine xenograft models and, recently, in a first-ever clinical uPAR PET study in cancer patients, including patients with PC. In this phase I study, a high and specific uptake of the tracer 64Cu-DOTA-AE105 was found in both primary...

Total-hip arthroplasty: Periprosthetic indium-111-labeled leukocyte activity and complementary technetium-99m-sulfur colloid imaging in suspected infection

International Nuclear Information System (INIS)

Palestro, C.J.; Kim, C.K.; Swyer, A.J.; Capozzi, J.D.; Solomon, R.W.; Goldsmith, S.J.

1990-01-01

Indium-111-labeled leukocyte images of 92 cemented total-hip arthroplasties were correlated with final diagnoses. Prostheses were divided into four zones: head (including acetabulum), trochanter, shaft, and tip. The presence (or absence) and intensity of activity in each zone was noted, and compared to the corresponding contralateral zone. Though present in all 23 infected arthroplasties, periprosthetic activity was also present in 77% of uninfected arthroplasties, and was greater than the contralateral zone 51% of the time. When analyzed by zone, head zone activity was the best criterion for infection (87% sensitivity, 94% specificity, 92% accuracy). Fifty of the arthroplasties were studied with combined labeled leukocyte/sulfur colloid imaging. Using incongruence of images as the criterion for infection, the sensitivity, specificity, and accuracy of the study were 100%, 97%, and 98%, respectively. While variable periprosthetic activity makes labeled leukocyte imaging alone unreliable for diagnosing hip arthroplasty infection, the addition of sulfur colloid imaging results in a highly accurate diagnostic procedure

Preliminary clinical results: an analyzing tool for 2D optical imaging in detection of active inflammation in rheumatoid arthritis

Science.gov (United States)

Adi Aizudin Bin Radin Nasirudin, Radin; Meier, Reinhard; Ahari, Carmen; Sievert, Matti; Fiebich, Martin; Rummeny, Ernst J.; No"l, Peter B.

2011-03-01

Optical imaging (OI) is a relatively new method in detecting active inflammation of hand joints of patients suffering from rheumatoid arthritis (RA). With the high number of people affected by this disease especially in western countries, the availability of OI as an early diagnostic imaging method is clinically highly relevant. In this paper, we present a newly in-house developed OI analyzing tool and a clinical evaluation study. Our analyzing tool extends the capability of existing OI tools. We include many features in the tool, such as region-based image analysis, hyper perfusion curve analysis, and multi-modality image fusion to aid clinicians in localizing and determining the intensity of inflammation in joints. Additionally, image data management options, such as the full integration of PACS/RIS, are included. In our clinical study we demonstrate how OI facilitates the detection of active inflammation in rheumatoid arthritis. The preliminary clinical results indicate a sensitivity of 43.5%, a specificity of 80.3%, an accuracy of 65.7%, a positive predictive value of 76.6%, and a negative predictive value of 64.9% in relation to clinical results from MRI. The accuracy of inflammation detection serves as evidence to the potential of OI as a useful imaging modality for early detection of active inflammation in patients with rheumatoid arthritis. With our in-house developed tool we extend the usefulness of OI imaging in the clinical arena. Overall, we show that OI is a fast, inexpensive, non-invasive and nonionizing yet highly sensitive and accurate imaging modality.-

A digital library for medical imaging activities

Science.gov (United States)

dos Santos, Marcelo; Furuie, Sérgio S.

2007-03-01

This work presents the development of an electronic infrastructure to make available a free, online, multipurpose and multimodality medical image database. The proposed infrastructure implements a distributed architecture for medical image database, authoring tools, and a repository for multimedia documents. Also it includes a peer-reviewed model that assures quality of dataset. This public repository provides a single point of access for medical images and related information to facilitate retrieval tasks. The proposed approach has been used as an electronic teaching system in Radiology as well.

My Body Looks Like That Girl’s: Body Mass Index Modulates Brain Activity during Body Image Self-Reflection among Young Women

Science.gov (United States)

Wen, Xin; She, Ying; Vinke, Petra Corianne; Chen, Hong

2016-01-01

Body image distress or body dissatisfaction is one of the most common consequences of obesity and overweight. We investigated the neural bases of body image processing in overweight and average weight young women to understand whether brain regions that were previously found to be involved in processing self-reflective, perspective and affective components of body image would show different activation between two groups. Thirteen overweight (O-W group, age = 20.31±1.70 years) and thirteen average weight (A-W group, age = 20.15±1.62 years) young women underwent functional magnetic resonance imaging while performing a body image self-reflection task. Among both groups, whole-brain analysis revealed activations of a brain network related to perceptive and affective components of body image processing. ROI analysis showed a main effect of group in ACC as well as a group by condition interaction within bilateral EBA, bilateral FBA, right IPL, bilateral DLPFC, left amygdala and left MPFC. For the A-W group, simple effect analysis revealed stronger activations in Thin-Control compared to Fat-Control condition within regions related to perceptive (including bilateral EBA, bilateral FBA, right IPL) and affective components of body image processing (including bilateral DLPFC, left amygdala), as well as self-reference (left MPFC). The O-W group only showed stronger activations in Fat-Control than in Thin-Control condition within regions related to the perceptive component of body image processing (including left EBA and left FBA). Path analysis showed that in the Fat-Thin contrast, body dissatisfaction completely mediated the group difference in brain response in left amygdala across the whole sample. Our data are the first to demonstrate differences in brain response to body pictures between average weight and overweight young females involved in a body image self-reflection task. These results provide insights for understanding the vulnerability to body image distress

Influence of Atmospheric Propagation on Performance of Laser Active Imaging System

International Nuclear Information System (INIS)

Li Yingchun; Sun Huayan; Guo Huichao; Zhao Yun

2011-01-01

Atmospheric propagation has serious influence on the performance of a good designed laser active imaging system. Atmospheric attenuation and turbulence are two main effects on laser atmospheric propagation. Imaging SNR (Signal-Noise-Ratio) and resolution are two key indexes to describe the performance of a laser active imaging system. Establishing the relation between system performance index and atmospheric propagation effect is significant. The paper analyzed the relation between imaging performance and atmospheric attenuation and turbulence through simulation. And also the experiments were done under different weather to validate the conclusion of simulation.

Real-time intravital imaging of pH variation associated with osteoclast activity.

Science.gov (United States)

Maeda, Hiroki; Kowada, Toshiyuki; Kikuta, Junichi; Furuya, Masayuki; Shirazaki, Mai; Mizukami, Shin; Ishii, Masaru; Kikuchi, Kazuya

2016-08-01

Intravital imaging by two-photon excitation microscopy (TPEM) has been widely used to visualize cell functions. However, small molecular probes (SMPs), commonly used for cell imaging, cannot be simply applied to intravital imaging because of the challenge of delivering them into target tissues, as well as their undesirable physicochemical properties for TPEM imaging. Here, we designed and developed a functional SMP with an active-targeting moiety, higher photostability, and a fluorescence switch and then imaged target cell activity by injecting the SMP into living mice. The combination of the rationally designed SMP with a fluorescent protein as a reporter of cell localization enabled quantitation of osteoclast activity and time-lapse imaging of its in vivo function associated with changes in cell deformation and membrane fluctuations. Real-time imaging revealed heterogenic behaviors of osteoclasts in vivo and provided insights into the mechanism of bone resorption.

Imaging of Stellar Surfacess Using Radio Facilities Including ALMA

Science.gov (United States)

O'Gorman, Eamon

2018-04-01

Until very recently, studies focusing on imaging stars at continuum radio wavelengths (here defined as submillimeter, millimeter, and centimeter wavelengths) has been scarce. These studies have mainly been carried out with the Very Large Array on a handful of evolved stars (i.e., Asymptotic Giant Branch and Red Supergiant stars) whereby their stellar disks have just about been spatially resolved. Some of these results however, have challenged our historical views on the nature of evolved star atmospheres. Now, the very long baselines of the Atacama Large Millimeter/submillimeter Array and the newly upgraded Karl G. Jansky Very Large Array provide a new opportunity to image these atmospheres at unprecedented spatial resolution and sensitivity across a much wider portion of the radio spectrum. In this talk I will first provide a history of stellar radio imaging and then discuss some recent exciting ALMA results. Finally I will present some brand new multi-wavelength ALMA and VLA results for the famous red supergiant Antares.

Live-Cell Imaging of Protease Activity: Assays to Screen Therapeutic Approaches.

Science.gov (United States)

Chalasani, Anita; Ji, Kyungmin; Sameni, Mansoureh; Mazumder, Samia H; Xu, Yong; Moin, Kamiar; Sloane, Bonnie F

2017-01-01

Methodologies to image and quantify the activity of proteolytic enzymes have been developed in an effort to identify protease-related druggable pathways that are involved in malignant progression of cancer. Our laboratory has pioneered techniques for functional live-cell imaging of protease activity in pathomimetic avatars for breast cancer. We analyze proteolysis in the context of proliferation and formation of structures by tumor cells in 3-D cultures over time (4D). In order to recapitulate the cellular composition and architecture of tumors in the pathomimetic avatars, we include other tumor-associated cells (e.g., fibroblasts, myoepithelial cells, microvascular endothelial cells). We also model noncellular aspects of the tumor microenvironment such as acidic pericellular pH. Use of pathomimetic avatars in concert with various types of imaging probes has allowed us to image, quantify, and follow the dynamics of proteolysis in the tumor microenvironment and to test interventions that impact directly or indirectly on proteolytic pathways. To facilitate use of the pathomimetic avatars for screening of therapeutic modalities, we have designed and fabricated custom 3D culture chambers with multiple wells that are either individual or connected by a channel to allow cells to migrate between wells. Optical glass microscope slides underneath an acrylic plate allow the cultures to be imaged with an inverted microscope. Fluid ports in the acrylic plate are at a level above the 3D cultures to allow introduction of culture media and test agents such as drugs into the wells and the harvesting of media conditioned by the cultures for immunochemical and biochemical analyses. We are using the pathomimetic avatars to identify druggable pathways, screen drug and natural product libraries and accelerate entry of validated drugs or natural products into clinical trials.

AMISS - Active and passive MIcrowaves for Security and Subsurface imaging

Science.gov (United States)

Soldovieri, Francesco; Slob, Evert; Turk, Ahmet Serdar; Crocco, Lorenzo; Catapano, Ilaria; Di Matteo, Francesca

2013-04-01

The FP7-IRSES project AMISS - Active and passive MIcrowaves for Security and Subsurface imaging is based on a well-combined network among research institutions of EU, Associate and Third Countries (National Research Council of Italy - Italy, Technische Universiteit Delft - The Netherlands, Yildiz Technical University - Turkey, Bauman Moscow State Technical University - Russia, Usikov Institute for Radio-physics and Electronics and State Research Centre of Superconductive Radioelectronics "Iceberg" - Ukraine and University of Sao Paulo - Brazil) with the aims of achieving scientific advances in the framework of microwave and millimeter imaging systems and techniques for security and safety social issues. In particular, the involved partners are leaders in the scientific areas of passive and active imaging and are sharing their complementary knowledge to address two main research lines. The first one regards the design, characterization and performance evaluation of new passive and active microwave devices, sensors and measurement set-ups able to mitigate clutter and increase information content. The second line faces the requirements to make State-of-the-Art processing tools compliant with the instrumentations developed in the first line, suitable to work in electromagnetically complex scenarios and able to exploit the unexplored possibilities offered by new instrumentations. The main goals of the project are: 1) Development/improvement and characterization of new sensors and systems for active and passive microwave imaging; 2) Set up, analysis and validation of state of art/novel data processing approach for GPR in critical infrastructure and subsurface imaging; 3) Integration of state of art and novel imaging hardware and characterization approaches to tackle realistic situations in security, safety and subsurface prospecting applications; 4) Development and feasibility study of bio-radar technology (system and data processing) for vital signs detection and

Ambient Seismic Imaging of Hydraulically Active Fractures at km Depths

Science.gov (United States)

Malin, P. E.; Sicking, C.

2017-12-01

Streaming Depth Images of ambient seismic signals using numerous, densely-distributed, receivers have revealed their connection to hydraulically active fractures at 0.5 to 5 km depths. Key for this type of imaging is very high-fold stacking over both multiple receives and periods of a few hours. Also important is suppression of waveforms from fixed, repeating sources such as pumps, generators, and traffic. A typical surface-based ambient SDI survey would use a 3D seismic receiver grid. It would have 1,000 to 4,000 uniformly distributed receivers at a density of 50/km2over the target. If acquired by borehole receivers buried 100 m deep, the density can be dropped by an order of magnitude. We show examples of the acquisition and signal processing scenarios used to produce the ambient images. (Sicking et al., SEG Interpretation, Nov 2017.) While the fracture-fluid source connection of SDI has been verified by drilling and various types of hydraulic tests, the precise nature of the signal's origin is not clear. At the current level of observation, the signals do not have identifiable phases, but can be focused using P wave velocities. Suggested sources are resonances of pressures fluctuations in the fractures, or small, continuous, slips on fractures surfaces. In either case, it appears that the driving mechanism is tectonic strain in an inherently unstable crust. Solid earth tides may enhance these strains. We illustrate the value of the ambient SDI method in its industrial application by showing case histories from energy industry and carbon-capture-sequestration projects. These include ambient images taken before, during, and after hydraulic treatments in un-conventional reservoirs. The results show not only locations of active fractures, but also their time responses to stimulation and production. Time-lapse ambient imaging can forecast and track events such as well interferences and production changes that can result from nearby treatments.

Efficient Active Contour and K-Means Algorithms in Image Segmentation

Directory of Open Access Journals (Sweden)

J.R. Rommelse

2004-01-01

Full Text Available In this paper we discuss a classic clustering algorithm that can be used to segment images and a recently developed active contour image segmentation model. We propose integrating aspects of the classic algorithm to improve the active contour model. For the resulting CVK and B-means segmentation algorithms we examine methods to decrease the size of the image domain. The CVK method has been implemented to run on parallel and distributed computers. By changing the order of updating the pixels, it was possible to replace synchronous communication with asynchronous communication and subsequently the parallel efficiency is improved.

Active polarization imaging system based on optical heterodyne balanced receiver

Science.gov (United States)

Xu, Qian; Sun, Jianfeng; Lu, Zhiyong; Zhou, Yu; Luan, Zhu; Hou, Peipei; Liu, liren

2017-08-01

Active polarization imaging technology has recently become the hot research field all over the world, which has great potential application value in the military and civil area. By introducing active light source, the Mueller matrix of the target can be calculated according to the incident light and the emitted or reflected light. Compared with conventional direct detection technology, optical heterodyne detection technology have higher receiving sensitivities, which can obtain the whole amplitude, frequency and phase information of the signal light. In this paper, an active polarization imaging system will be designed. Based on optical heterodyne balanced receiver, the system can acquire the horizontal and vertical polarization of reflected optical field simultaneously, which contain the polarization characteristic of the target. Besides, signal to noise ratio and imaging distance can be greatly improved.

Implicit Active Contours Driven by Local and Global Image Fitting Energy for Image Segmentation and Target Localization

Directory of Open Access Journals (Sweden)

Xiaosheng Yu

2013-01-01

Full Text Available We propose a novel active contour model in a variational level set formulation for image segmentation and target localization. We combine a local image fitting term and a global image fitting term to drive the contour evolution. Our model can efficiently segment the images with intensity inhomogeneity with the contour starting anywhere in the image. In its numerical implementation, an efficient numerical schema is used to ensure sufficient numerical accuracy. We validated its effectiveness in numerous synthetic images and real images, and the promising experimental results show its advantages in terms of accuracy, efficiency, and robustness.

99Tcm-labelled leucocyte imaging in active rheumatoid arthritis

International Nuclear Information System (INIS)

Al-Janabi, M.A.; Jones, A.K.P.; Solanki, K.; Sobnack, R.; Bomanji, J.; Al-Nahhas, A.A.; Britton, K.E.; Huskisson, E.C.; Doyle, D.V.

1988-01-01

A simplified technique of labelling leucocytes with technetium-99m is described and applied to patients with active rheumatoid arthritis. The clinically active and less active knees in seven patients were imaged and the uptake of labelled leucocytes was measured. The measurements were repeated after local steroid injection into nine painful knees. A 50-80% reduction in leucocyte uptake localized to the region of the synovium was demonstrated in the eight knees which showed clinical responses and a rise of 8% in the non-responder. There was a variable response in the knees that were not injected. 99 Tc m leucocyte imaging in rheumatoid arthritis is able to assess objectively joint inflammation and its response to treatment. (author)

Representation of activity in images using geospatial temporal graphs

Science.gov (United States)

Brost, Randolph; McLendon, III, William C.; Parekh, Ojas D.; Rintoul, Mark Daniel; Watson, Jean-Paul; Strip, David R.; Diegert, Carl

2018-05-01

Various technologies pertaining to modeling patterns of activity observed in remote sensing images using geospatial-temporal graphs are described herein. Graphs are constructed by representing objects in remote sensing images as nodes, and connecting nodes with undirected edges representing either distance or adjacency relationships between objects and directed edges representing changes in time. Activity patterns may be discerned from the graphs by coding nodes representing persistent objects like buildings differently from nodes representing ephemeral objects like vehicles, and examining the geospatial-temporal relationships of ephemeral nodes within the graph.

Fast Graph Partitioning Active Contours for Image Segmentation Using Histograms

Directory of Open Access Journals (Sweden)

Nath SumitK

2009-01-01

Full Text Available Abstract We present a method to improve the accuracy and speed, as well as significantly reduce the memory requirements, for the recently proposed Graph Partitioning Active Contours (GPACs algorithm for image segmentation in the work of Sumengen and Manjunath (2006. Instead of computing an approximate but still expensive dissimilarity matrix of quadratic size, , for a 2D image of size and regular image tiles of size , we use fixed length histograms and an intensity-based symmetric-centrosymmetric extensor matrix to jointly compute terms associated with the complete dissimilarity matrix. This computationally efficient reformulation of GPAC using a very small memory footprint offers two distinct advantages over the original implementation. It speeds up convergence of the evolving active contour and seamlessly extends performance of GPAC to multidimensional images.

CMOS Active-Pixel Image Sensor With Intensity-Driven Readout

Science.gov (United States)

Langenbacher, Harry T.; Fossum, Eric R.; Kemeny, Sabrina

1996-01-01

Proposed complementary metal oxide/semiconductor (CMOS) integrated-circuit image sensor automatically provides readouts from pixels in order of decreasing illumination intensity. Sensor operated in integration mode. Particularly useful in number of image-sensing tasks, including diffractive laser range-finding, three-dimensional imaging, event-driven readout of sparse sensor arrays, and star tracking.

Histomorphology of canine urethral sphincter systems, including three-dimensional reconstruction and magnetic resonance imaging.

Science.gov (United States)

Stolzenburg, Jens-Uwe; Neuhaus, Jochen; Liatsikos, Evangelos N; Schwalenberg, Thilo; Ludewig, Eberhard; Ganzer, Roman

2006-03-01

To present a detailed anatomic description and comparison of the smooth and striated urethral sphincter in male and female dogs. We performed a thorough histologic evaluation, three-dimensional reconstruction, and magnetic resonance imaging of the lower urinary tract of male and female dogs. The lower urinary tract anatomy was investigated in 16 male and 18 female dogs by serial sectioning, including immunohistochemical staining and three-dimensional reconstruction. Magnetic resonance imaging performed in 5 male and 5 female dogs before histologic investigation helped to demonstrate the anatomy in vivo. A urethral sphincter muscle in both sexes existed without muscular connection to the pelvic floor. It ran circularly and consisted of an inner smooth and outer striated muscular part. In the female dog, the striated muscle encircled the urethra and vagina in the caudal third of the membranous urethra (musculus urethrovaginalis). A urinary diaphragm (diaphragma urogenitale) could not be found histologically or by magnetic resonance imaging. The dog is a suitable animal model for investigations of the urethral sphincter. In the female dog, attention should be given to the special topography of the musculus urethrovaginalis.

Circularly polarized antennas for active holographic imaging through barriers

Science.gov (United States)

McMakin, Douglas L [Richland, WA; Severtsen, Ronald H [Richland, WA; Lechelt, Wayne M [West Richland, WA; Prince, James M [Kennewick, WA

2011-07-26

Circularly-polarized antennas and their methods of use for active holographic imaging through barriers. The antennas are dielectrically loaded to optimally match the dielectric constant of the barrier through which images are to be produced. The dielectric loading helps to remove barrier-front surface reflections and to couple electromagnetic energy into the barrier.

Defining active sacroiliitis on magnetic resonance imaging (MRI) for classification of axial spondyloarthritis: a consensual approach by the ASAS/OMERACT MRI group

DEFF Research Database (Denmark)

Rudwaleit, M; Jurik, A G; Hermann, K-G A

2009-01-01

BACKGROUND: Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. OBJECTIVES: To identify and describe MRI findings in sacroiliitis and...... relevant for sacroiliitis have been defined by consensus by a group of rheumatologists and radiologists. These definitions should help in applying correctly the imaging feature "active sacroiliitis by MRI" in the new ASAS classification criteria for axial SpA.......BACKGROUND: Magnetic resonance imaging (MRI) of sacroiliac joints has evolved as the most relevant imaging modality for diagnosis and classification of early axial spondyloarthritis (SpA) including early ankylosing spondylitis. OBJECTIVES: To identify and describe MRI findings in sacroiliitis...... conditions which may mimic SpA. Descriptions of the pathological findings and technical requirements for the appropriate acquisition were formulated. In a consensual approach MRI findings considered to be essential for sacroiliitis were defined. RESULTS: Active inflammatory lesions such as bone marrow oedema...

Magnetic resonance imaging guided transatrial electrophysiological studies in swine using active catheter tracking - experience with 14 cases

Energy Technology Data Exchange (ETDEWEB)

Grothoff, Matthias; Gutberlet, Matthias [University of Leipzig - Heart Center, Department of Radiology, Leipzig (Germany); Hindricks, Gerhard; Sommer, Philipp; Hilbert, Sebastian [University of Leipzig - Heart Center, Department of Electrophysiology, Leipzig (Germany); Fleiter, Christian [Helios Klinikum Berlin-Buch, Department of Orthopaedic Surgery, Berlin (Germany); Schnackenburg, Bernhard [Philips Healthcare, Hamburg (Germany); Weiss, Steffen; Krueger, Sascha [Philips Innovative Technologies, Hamburg (Germany); Piorkowski, Christopher; Gaspar, Thomas [University of Dresden - Heart Center, Department of Electrophysiology, Dresden (Germany); Wedan, Steve; Lloyd, Thomas [Imricor Medical Systems, Burnsville, MN (United States)

2017-05-15

To evaluate the feasibility of performing comprehensive Cardiac Magnetic resonance (CMR) guided electrophysiological (EP) interventions in a porcine model encompassing left atrial access. After introduction of two femoral sheaths 14 swine (41 ± 3.6 kg) were transferred to a 1.5 T MR scanner. A three-dimensional whole-heart sequence was acquired followed by segmentation and the visualization of all heart chambers using an image-guidance platform. Two MR conditional catheters were inserted. The interventional protocol consisted of intubation of the coronary sinus, activation mapping, transseptal left atrial access (n = 4), generation of ablation lesions and eventually ablation of the atrioventricular (AV) node. For visualization of the catheter tip active tracking was used. Catheter positions were confirmed by passive real-time imaging. Total procedure time was 169 ± 51 minutes. The protocol could be completed in 12 swine. Two swine died from AV-ablation induced ventricular fibrillation. Catheters could be visualized and navigated under active tracking almost exclusively. The position of the catheter tips as visualized by active tracking could reliably be confirmed with passive catheter imaging. Comprehensive CMR-guided EP interventions including left atrial access are feasible in swine using active catheter tracking. (orig.)

Imaging and Modeling Laboratory in Neurobiology and Oncology - IMNC. Activity report 2008-2012

International Nuclear Information System (INIS)

Charon, Yves; Arlaud, Nathalie; Mastrippolito, Roland

2014-09-01

The Imaging and Modeling Laboratory in Neurobiology and Oncology (IMNC) is an interdisciplinary unit shared between the Paris-Sud and Paris-Diderot universities and the National Institute of Nuclear and particle physics (IN2P3). Created in January 2006, the laboratory activities are structured around three main topics: the clinical and pre-clinical multi-modal imaging (optical and isotopic), the modeling of tumoral processes, and radiotherapy. This report presents the activities of the laboratory during the years 2008-2012: 1 - Forewords; 2 - Highlights; 3 - Research teams: Small animal imaging; Metabolism, imaging and olfaction; Surgery imaging in oncology; Quantification in molecular imaging; Modeling of biological systems; 4 - Technical innovations: Instrumentation, Scientific calculation, Biology department, valorisation and open-source softwares; 5 - Publications; 6 - Scientific life, communication and teaching activities; 7 - Laboratory operation; 8 - Perspectives

Beyond image interpretation: Capturing the impact of radiographer advanced practice through activity diaries

International Nuclear Information System (INIS)

Snaith, B.; Milner, R.C.; Harris, M.A.

2016-01-01

Background: There is limited evidence of the impact of radiographers working in advanced roles beyond task substitution. This study reviews the contribution of advanced (and consultant) practitioner radiographers to service delivery whilst reporting radiographs and demonstrates the impact this has on patients and staff, both internal and external to the imaging department. Method: The study was a prospective exploratory study using activity diaries to allow interval sampling when individuals were rostered to report. Data was coded using a compiled list of activities and recorded in 15-min intervals over the period of one week. Thirteen radiographers who independently report radiographs participated across 6 locations in a busy multisite English National Health Service (NHS) Trust. Results: Radiographers reported the majority of the examinations during the study period (n = 4512/5671; 79.6%). The total number of coded activities recorded over the study period was 1527, equating to 380.5 relative hours. The majority of available time was spent reporting, including dictating and verifying the reports of colleagues or trainees, although 69.5% of reporting time was interrupted. Based upon the hours of reporting there was an average of 19.3 reports (patient episodes) produced per hour. Direct patient care tasks and support for staff in decision making were regularly documented. Supplementary tasks included administrative activity, amendments to rotas, preparing presentations and documenting incidents identified during reporting. Conclusion: This study has demonstrated the breadth and complexity of the activities performed by advanced practice radiographers. The findings confirm their role in supporting service delivery beyond image interpretation. - Highlights: • Radiographers can make a significant contribution to reporting workloads. • The range of activities undertaken when reporting is complex and varied. • Reporting radiographers impact on staff, patients

7 CFR 981.441 - Credit for market promotion activities, including paid advertising.

Science.gov (United States)

2010-01-01

... promotion activities, including paid advertising. (a) In order for a handler to receive credit for his/her... 7 Agriculture 8 2010-01-01 2010-01-01 false Credit for market promotion activities, including paid advertising. 981.441 Section 981.441 Agriculture Regulations of the Department of Agriculture (Continued...

Technical and economic considerations of using actively shielded superconducting magnets for MR imaging

International Nuclear Information System (INIS)

McDougall, L.; Hawksworth, D.

1986-01-01

Air-cored superconducting magnets provide uniform fields for MR imaging over large volumes at the lowest cost per gauss of available technologies. Traditional solenoidal designs have an air flux return path and contaminate the clinical environment. Actively shielded magnets comprising one magnet inside another provide the maximum possible fringe field reduction per unit cost. The use of iron to reduce fringe field is more costly than active shielding and much less flexible. Solutions to providing fringe field cancellation are possible using industry standard cryostat dimensions. Costs of materials are minimized by designing with coil optimization routines that include stress parameters

Active Mask Segmentation of Fluorescence Microscope Images

OpenAIRE

Srinivasa, Gowri; Fickus, Matthew C.; Guo, Yusong; Linstedt, Adam D.; Kovačević, Jelena

2009-01-01

We propose a new active mask algorithm for the segmentation of fluorescence microscope images of punctate patterns. It combines the (a) flexibility offered by active-contour methods, (b) speed offered by multiresolution methods, (c) smoothing offered by multiscale methods, and (d) statistical modeling offered by region-growing methods into a fast and accurate segmentation tool. The framework moves from the idea of the “contour” to that of “inside and outside”, or, masks, allowing for easy mul...

Multiple Active Contours Guided by Differential Evolution for Medical Image Segmentation

Science.gov (United States)

Cruz-Aceves, I.; Avina-Cervantes, J. G.; Lopez-Hernandez, J. M.; Rostro-Gonzalez, H.; Garcia-Capulin, C. H.; Torres-Cisneros, M.; Guzman-Cabrera, R.

2013-01-01

This paper presents a new image segmentation method based on multiple active contours guided by differential evolution, called MACDE. The segmentation method uses differential evolution over a polar coordinate system to increase the exploration and exploitation capabilities regarding the classical active contour model. To evaluate the performance of the proposed method, a set of synthetic images with complex objects, Gaussian noise, and deep concavities is introduced. Subsequently, MACDE is applied on datasets of sequential computed tomography and magnetic resonance images which contain the human heart and the human left ventricle, respectively. Finally, to obtain a quantitative and qualitative evaluation of the medical image segmentations compared to regions outlined by experts, a set of distance and similarity metrics has been adopted. According to the experimental results, MACDE outperforms the classical active contour model and the interactive Tseng method in terms of efficiency and robustness for obtaining the optimal control points and attains a high accuracy segmentation. PMID:23983809

Multiple Active Contours Guided by Differential Evolution for Medical Image Segmentation

Directory of Open Access Journals (Sweden)

I. Cruz-Aceves

2013-01-01

Full Text Available This paper presents a new image segmentation method based on multiple active contours guided by differential evolution, called MACDE. The segmentation method uses differential evolution over a polar coordinate system to increase the exploration and exploitation capabilities regarding the classical active contour model. To evaluate the performance of the proposed method, a set of synthetic images with complex objects, Gaussian noise, and deep concavities is introduced. Subsequently, MACDE is applied on datasets of sequential computed tomography and magnetic resonance images which contain the human heart and the human left ventricle, respectively. Finally, to obtain a quantitative and qualitative evaluation of the medical image segmentations compared to regions outlined by experts, a set of distance and similarity metrics has been adopted. According to the experimental results, MACDE outperforms the classical active contour model and the interactive Tseng method in terms of efficiency and robustness for obtaining the optimal control points and attains a high accuracy segmentation.

Active gated imaging for automotive safety applications

Science.gov (United States)

Grauer, Yoav; Sonn, Ezri

2015-03-01

The paper presents the Active Gated Imaging System (AGIS), in relation to the automotive field. AGIS is based on a fast gated-camera equipped with a unique Gated-CMOS sensor, and a pulsed Illuminator, synchronized in the time domain to record images of a certain range of interest which are then processed by computer vision real-time algorithms. In recent years we have learned the system parameters which are most beneficial to night-time driving in terms of; field of view, illumination profile, resolution and processing power. AGIS provides also day-time imaging with additional capabilities, which enhances computer vision safety applications. AGIS provides an excellent candidate for camera-based Advanced Driver Assistance Systems (ADAS) and the path for autonomous driving, in the future, based on its outstanding low/high light-level, harsh weather conditions capabilities and 3D potential growth capabilities.

Magnetic Resonance Imaging Features as Surrogate Markers of X-Linked Hypophosphatemic Rickets Activity.

Science.gov (United States)

Lempicki, Marta; Rothenbuhler, Anya; Merzoug, Valérie; Franchi-Abella, Stéphanie; Chaussain, Catherine; Adamsbaum, Catherine; Linglart, Agnès

2017-01-01

X-linked hypophosphatemic rickets (XLH) is the most common form of inheritable rickets. Rickets treatment is monitored by assessing alkaline phosphatase (ALP) levels, clinical features, and radiographs. Our objectives were to describe the magnetic resonance imaging (MRI) features of XLH and to assess correlations with disease activity. Twenty-seven XLH patients (median age 9.2 years) were included in this prospective single-center observational study. XLH activity was assessed using height, leg bowing, dental abscess history, and serum ALP levels. We looked for correlations between MRI features and markers of disease activity. On MRI, the median maximum width of the physis was 5.6 mm (range 4.8-7.8; normal 1.5 mm in all of the patients. The appearance of the zone of provisional calcification was abnormal on 21 MRI images (78%), Harris lines were present on 24 (89%), and bone marrow signal abnormalities were present on 16 (59%). ALP levels correlated with the maximum physeal widening and with the transverse extent of the widening. MRI of the knee provides precise rickets patterns that are correlated with ALP, an established biochemical marker of the disease, avoiding X-ray exposure and providing surrogate quantitative markers of disease activity. © 2017 S. Karger AG, Basel.

State-dependent cellular activity patterns of the cat paraventricular hypothalamus measured by reflectance imaging

DEFF Research Database (Denmark)

Kristensen, Morten Pilgaard; Rector, D M; Poe, G R

1996-01-01

Activity within the cat paraventricular hypothalamus (PVH) during sleep and waking states was measured by quantifying intrinsic tissue reflectivity. A fiber optic probe consisting of a 1.0 mm coherent image conduit, surrounded by plastic fibers which conducted 660 nm source light, was attached...... to a charge-coupled device camera, and positioned over the PVH in five cats. Electrodes for assessing state variables, including electroencephalographic activity, eye movement, and somatic muscle tone were also placed. After surgical recovery, reflected light intensity was measured continuously at 2.5 Hz...

Beyond the limits of present active matrix flat-panel imagers (AMFPIs) for diagnostic radiology

Science.gov (United States)

Antonuk, Larry E.; El-Mohri, Youcef; Jee, Kyung-Wook; Maolinbay, Manat; Nassif, Samer C.; Rong, Xiujiang; Siewerdsen, Jeffrey H.; Zhao, Qihua; Street, Robert A.

1999-05-01

A theoretical cascaded systems analysis of the performance limits of x-ray imagers based on thin-film, active matrix flat-panel technology is presented. This analysis specifically focuses upon an examination of the functional dependence of the detective quantum efficiency on exposure. While the DQE of AMFPI systems is relatively high at the large exposure levels associated with radiographic x-ray imaging, there is a significant decline in DQE with decreasing exposure over the medium and lower end of the exposure range associated with fluoroscopic imaging. This fall-off in DQE originates from the relatively large size of the additive noise of AMFPI systems compared to their overall system gain. Therefore, strategies to diminish additive noise and increase system gain should significantly improve performance. Potential strategies for noise reduction include the use of charge compensation lines while strategies for gain enhancement include continuous photodiodes, pixel amplification structures, or higher gain converters. The effect of the implementation of such strategies is examined for a variety for hypothetical imager configurations. Through the modeling of these configurations, such enhancements are shown to hold the potential of making low frequency DQE response large and essentially independent of exposure while greatly reducing the fall-off in DQE at higher spatial frequencies.

Robot Vision to Monitor Structures in Invisible Fog Environments Using Active Imaging Technology

Energy Technology Data Exchange (ETDEWEB)

Park, Seungkyu; Park, Nakkyu; Baik, Sunghoon; Choi, Youngsoo; Jeong, Kyungmin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

Active vision is a direct visualization technique using a highly sensitive image sensor and a high intensity illuminant. Range-gated imaging (RGI) technique providing 2D and 3D images is one of emerging active vision technologies. The RGI technique extracts vision information by summing time sliced vision images. In the RGI system, objects are illuminated for ultra-short time by a high intensity illuminant and then the light reflected from objects is captured by a highly sensitive image sensor with the exposure of ultra-short time. The RGI system provides 2D and 3D image data from several images and it moreover provides clear images from invisible fog and smoke environment by using summing of time-sliced images. Nowadays, the Range-gated (RG) imaging is an emerging technology in the field of surveillance for security applications, especially in the visualization of invisible night and fog environment. Although RGI viewing was discovered in the 1960's, this technology is, nowadays, more and more applicable by virtue of the rapid development of optical and sensor technologies, such as highly sensitive imaging sensor and ultra-short pulse laser light. In contrast to passive vision systems, this technology enables operation even in harsh environments like fog and smoke. During the past decades, several applications of this technology have been applied in target recognition and in harsh environments, such as fog, underwater vision. Also, this technology has been demonstrated 3D imaging based on range-gated imaging. In this paper, a robot system to monitor structures in invisible fog environment is developed using an active range-gated imaging technique. The system consists of an ultra-short pulse laser device and a highly sensitive imaging sensor. The developed vision system is carried out to monitor objects in invisible fog environment. The experimental result of this newly approach vision system is described in this paper. To see invisible objects in fog

Robot Vision to Monitor Structures in Invisible Fog Environments Using Active Imaging Technology

International Nuclear Information System (INIS)

Park, Seungkyu; Park, Nakkyu; Baik, Sunghoon; Choi, Youngsoo; Jeong, Kyungmin

2014-01-01

Active vision is a direct visualization technique using a highly sensitive image sensor and a high intensity illuminant. Range-gated imaging (RGI) technique providing 2D and 3D images is one of emerging active vision technologies. The RGI technique extracts vision information by summing time sliced vision images. In the RGI system, objects are illuminated for ultra-short time by a high intensity illuminant and then the light reflected from objects is captured by a highly sensitive image sensor with the exposure of ultra-short time. The RGI system provides 2D and 3D image data from several images and it moreover provides clear images from invisible fog and smoke environment by using summing of time-sliced images. Nowadays, the Range-gated (RG) imaging is an emerging technology in the field of surveillance for security applications, especially in the visualization of invisible night and fog environment. Although RGI viewing was discovered in the 1960's, this technology is, nowadays, more and more applicable by virtue of the rapid development of optical and sensor technologies, such as highly sensitive imaging sensor and ultra-short pulse laser light. In contrast to passive vision systems, this technology enables operation even in harsh environments like fog and smoke. During the past decades, several applications of this technology have been applied in target recognition and in harsh environments, such as fog, underwater vision. Also, this technology has been demonstrated 3D imaging based on range-gated imaging. In this paper, a robot system to monitor structures in invisible fog environment is developed using an active range-gated imaging technique. The system consists of an ultra-short pulse laser device and a highly sensitive imaging sensor. The developed vision system is carried out to monitor objects in invisible fog environment. The experimental result of this newly approach vision system is described in this paper. To see invisible objects in fog

Predictive value of diffusion-weighted imaging without and with including contrast-enhanced magnetic resonance imaging in image analysis of head and neck squamous cell carcinoma

Energy Technology Data Exchange (ETDEWEB)

Noij, Daniel P., E-mail: d.noij@vumc.nl [Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands); Pouwels, Petra J.W., E-mail: pjw.pouwels@vumc.nl [Department of Physics and Medical Technology, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands); Ljumanovic, Redina, E-mail: rljumanovic@adventh.org [Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands); Knol, Dirk L., E-mail: dirklknol@gmail.com [Department of Epidemiology and Biostatistics, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands); Doornaert, Patricia, E-mail: p.doornaert@vumc.nl [Department of Radiation Oncology, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands); Bree, Remco de, E-mail: r.debree@vumc.nl [Department of Otolaryngology – Head and Neck Surgery, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands); Castelijns, Jonas A., E-mail: j.castelijns@vumc.nl [Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands); Graaf, Pim de, E-mail: p.degraaf@vumc.nl [Department of Radiology and Nuclear Medicine, VU University Medical Center, De Boelelaan 1117, Amsterdam, Noord-Holland (Netherlands)

2015-01-15

Highlights: • Primary tumor volume and lymph node ADC1000 are predictors of survival. • CE-T1WI does not improve the prognostic capacity of DWI. • Using CE-T1WI for ROI placement results in lower interobserver agreement. - Abstract: Objectives: To assess disease-free survival (DFS) in head and neck squamous cell carcinoma (HNSCC) treated with (chemo)radiotherapy ([C]RT). Methods: Pretreatment MR-images of 78 patients were retrospectively studied. Apparent diffusion coefficients (ADC) were calculated with two sets of two b-values: 0–750 s/mm{sup 2} (ADC{sub 750}) and 0–1000 s/mm{sup 2} (ADC{sub 1000}). One observer assessed tumor volume on T1-WI. Two independent observers assessed ADC-values of primary tumor and largest lymph node in two sessions (i.e. without and with including CE-T1WI in image analysis). Interobserver and intersession agreement were assessed with intraclass correlation coefficients (ICC) separately for ADC{sub 750} and ADC{sub 1000}. Lesion volumes and ADC-values were related to DFS using Cox regression analysis. Results: Median follow-up was 18 months. Interobserver ICC was better without than with CE-T1WI (primary tumor: 0.92 and 0.75–0.83, respectively; lymph node: 0.81–0.83 and 0.61–0.64, respectively). Intersession ICC ranged from 0.84 to 0.89. With CE-T1WI, mean ADC-values of primary tumor and lymph node were higher at both b-values than without CE-T1WI (P < 0.001). Tumor volume (sensitivity: 73%; specificity: 57%) and lymph node ADC{sub 1000} (sensitivity: 71–79%; specificity: 77–79%) were independent significant predictors of DFS without and with including CE-T1WI (P < 0.05). Conclusions: Pretreatment primary tumor volume and lymph node ADC{sub 1000} were significant independent predictors of DFS in HNSCC treated with (C)RT. DFS could be predicted from ADC-values acquired without and with including CE-T1WI in image analysis. The inclusion of CE-T1WI did not result in significant improvements in the predictive value of

Satellite images to aircraft in flight. [GEOS image transmission feasibility analysis

Science.gov (United States)

Camp, D.; Luers, J. K.; Kadlec, P. W.

1977-01-01

A study has been initiated to evaluate the feasibility of transmitting selected GOES images to aircraft in flight. Pertinent observations that could be made from satellite images on board aircraft include jet stream activity, cloud/wind motion, cloud temperatures, tropical storm activity, and location of severe weather. The basic features of the Satellite Aircraft Flight Environment System (SAFES) are described. This system uses East GOES and West GOES satellite images, which are interpreted, enhanced, and then retransmitted to designated aircraft.

SPR imaging combined with cyclic voltammetry for the detection of neural activity

Directory of Open Access Journals (Sweden)

Hui Li

2014-03-01

Full Text Available Surface plasmon resonance (SPR detects changes in refractive index at a metal-dielectric interface. In this study, SPR imaging (SPRi combined with cyclic voltammetry (CV was applied to detect neural activity in isolated bullfrog sciatic nerves. The neural activities induced by chemical and electrical stimulation led to an SPR response, and the activities were recorded in real time. The activities of different parts of the sciatic nerve were recorded and compared. The results demonstrated that SPR imaging combined with CV is a powerful tool for the investigation of neural activity.

Functional magnetic resonance imaging of hippocampal activation during silent mantra meditation.

Science.gov (United States)

Engström, Maria; Pihlsgård, Johan; Lundberg, Peter; Söderfeldt, Birgitta

2010-12-01

The objective of the present study was to investigate whether moderately experienced meditators activate hippocampus and the prefrontal cortex during silent mantra meditation, as has been observed in earlier studies on subjects with several years of practice. Subjects with less than 2 years of meditation practice according to the Kundalini yoga or Acem tradition were examined by functional magnetic resonance imaging during silent mantra meditation, using an on-off block design. Whole-brain as well as region-of-interest analyses were performed. The most significant activation was found in the bilateral hippocampus/parahippocampal formations. Other areas with significant activation were the bilateral middle cingulate cortex and the bilateral precentral cortex. No activation in the anterior cingulate cortex was found, and only small activation clusters were observed in the prefrontal cortex. In conclusion, the main finding in this study was the significant activation in the hippocampi, which also has been correlated with meditation in several previous studies on very experienced meditators. We propose that the hippocampus is activated already after moderate meditation practice and also during different modes of meditation, including relaxation. The role of hippocampal activity during meditation should be further clarified in future studies, especially by investigating whether the meditation-correlated hippocampal activity is related to memory consolidation.

Gallbladder shape extraction from ultrasound images using active contour models.

Science.gov (United States)

Ciecholewski, Marcin; Chochołowicz, Jakub

2013-12-01

Gallbladder function is routinely assessed using ultrasonographic (USG) examinations. In clinical practice, doctors very often analyse the gallbladder shape when diagnosing selected disorders, e.g. if there are turns or folds of the gallbladder, so extracting its shape from USG images using supporting software can simplify a diagnosis that is often difficult to make. The paper describes two active contour models: the edge-based model and the region-based model making use of a morphological approach, both designed for extracting the gallbladder shape from USG images. The active contour models were applied to USG images without lesions and to those showing specific disease units, namely, anatomical changes like folds and turns of the gallbladder as well as polyps and gallstones. This paper also presents modifications of the edge-based model, such as the method for removing self-crossings and loops or the method of dampening the inflation force which moves nodes if they approach the edge being determined. The user is also able to add a fragment of the approximated edge beyond which neither active contour model will move if this edge is incomplete in the USG image. The modifications of the edge-based model presented here allow more precise results to be obtained when extracting the shape of the gallbladder from USG images than if the morphological model is used. © 2013 Elsevier Ltd. Published by Elsevier Ltd. All rights reserved.

Baseline and cognition activated brain SPECT imaging in depression

International Nuclear Information System (INIS)

Zhao Jinhua; Lin Xiangtong; Jiang Kaida; Liu Yongchang; Xu Lianqin

1998-01-01

Purpose: To evaluate the regional cerebral blood flow (rCBF) abnormalities through the semiquantitative analysis of the baseline and cognition activated rCBF imaging in unmedicated depressed patients. Methods: 27 depressed patients unmedicated by anti-depressants were enrolled. The diagnosis (depression of moderate degree with somatization) was confirmed by the ICD-10 criteria. 15 age matched normal controls were studied under identical conditions. Baseline and cognition activated 99m Tc-ECD SPECT were performed on 21 of the 27 patients with depression and 13 of the 15 normal controls. Baseline 99m Tc-ECD SPECT alone were performed on the rest 6 patients with depression and 2 normal controls. The cognitive activation is achieved by Wisconsin Card Sorting Test (WCST). 1110 MBq of 99m Tc-ECD was administered by intravenous bolus injection 5 minutes after the onset of the WCST. Semi-quantitative analysis was conducted with the 7th, 8th, 9th, 10th, 11th slices of the transaxial imaging. rCBF ratios of every ROI were calculated using the average tissue activity in the region divided by the maximum activity in the cerebellum. Results: 1) The baseline rCBF of left frontal (0.720) and left temporal lobe (0.720) were decreased significantly in depressed patients comparing with those of the control subjects. 2) The activated rCBF of left frontal lobe (0.719) and left temporal lobe (0.690), left parietal lobe (0.701) were decreased evidently than those of the controls. Conclusions: 1) Hypoperfusions of left frontal and left temporal cortexes were identified in patients with depression. 2) The hypoperfusion of left frontal and left temporal cortexes may be the cause of cognition disorder and depressed mood in patients with depression. 3) Cognition activated brain perfusion imaging is helpful for making a more accurate diagnosis of depression

Magnetic resonance imaging of the active second stage of labour: Proof of principle

International Nuclear Information System (INIS)

Guettler, F.V.; Heinrich, A.; Rump, J.; Bucourt, M. de; Hamm, B.; Teichgraeber, U.K.; Schnackenburg, B.; Bamberg, C.

2012-01-01

To prove that magnetic resonance imaging of foetal anatomy during the active second stage of vaginal delivery is feasible. Initially, five pregnant volunteers around the 30th week of gestation were examined in an open MRI. Based on the findings, one vaginal delivery was acquired under real-time imaging. To monitor the birth status during image acquisition, an MR-compatible wireless cardiotocography (CTG) system was built. Single-shot sequence parameters were optimised to compensate motion artefacts during labour. Safety requirements to monitor the birth process under real-time MR imaging were met. High-resolution MR images were acquired immediately before and after delivery. In one patient, TSE single-shot cinematic sequences of the active second stage of labour were obtained. All sequences were adapted to tolerate movement of the mother and infant, as well as residual noise from the CTG. Furthermore, the MR imaging during labour showed only minor image artefacts. CTG-monitored acquisition of MRI series during the active second stage of delivery is feasible. Image quality should allow various further studies to improve models for birth simulation as well as potential investigation of obstructed labour and obstetric complications. (orig.)

State-dependent cellular activity patterns of the cat paraventricular hypothalamus measured by reflectance imaging

DEFF Research Database (Denmark)

Kristensen, Morten Pilgaard; Rector, D M; Poe, G R

1996-01-01

Activity within the cat paraventricular hypothalamus (PVH) during sleep and waking states was measured by quantifying intrinsic tissue reflectivity. A fiber optic probe consisting of a 1.0 mm coherent image conduit, surrounded by plastic fibers which conducted 660 nm source light, was attached...... to a charge-coupled device camera, and positioned over the PVH in five cats. Electrodes for assessing state variables, including electroencephalographic activity, eye movement, and somatic muscle tone were also placed. After surgical recovery, reflected light intensity was measured continuously at 2.5 Hz...... changes with behavioral state in a regionally specific manner, and that overall activity increases during quiet sleep, and is even more enhanced in active sleep. PVH activation could be expected to stimulate pituitary release of adrenocorticotropic hormone (ACTH) and affect input to autonomic regulatory...

A method for energy window optimization for quantitative tasks that includes the effects of model-mismatch on bias: application to Y-90 bremsstrahlung SPECT imaging

International Nuclear Information System (INIS)

Rong Xing; Du Yong; Frey, Eric C

2012-01-01

Quantitative Yttrium-90 ( 90 Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging has shown great potential to provide reliable estimates of 90 Y activity distribution for targeted radionuclide therapy dosimetry applications. One factor that potentially affects the reliability of the activity estimates is the choice of the acquisition energy window. In contrast to imaging conventional gamma photon emitters where the acquisition energy windows are usually placed around photopeaks, there has been great variation in the choice of the acquisition energy window for 90 Y imaging due to the continuous and broad energy distribution of the bremsstrahlung photons. In quantitative imaging of conventional gamma photon emitters, previous methods for optimizing the acquisition energy window assumed unbiased estimators and used the variance in the estimates as a figure of merit (FOM). However, for situations, such as 90 Y imaging, where there are errors in the modeling of the image formation process used in the reconstruction there will be bias in the activity estimates. In 90 Y bremsstrahlung imaging this will be especially important due to the high levels of scatter, multiple scatter, and collimator septal penetration and scatter. Thus variance will not be a complete measure of reliability of the estimates and thus is not a complete FOM. To address this, we first aimed to develop a new method to optimize the energy window that accounts for both the bias due to model-mismatch and the variance of the activity estimates. We applied this method to optimize the acquisition energy window for quantitative 90 Y bremsstrahlung SPECT imaging in microsphere brachytherapy. Since absorbed dose is defined as the absorbed energy from the radiation per unit mass of tissues in this new method we proposed a mass-weighted root mean squared error of the volume of interest (VOI) activity estimates as the FOM. To calculate this FOM, two analytical expressions were derived for

A method for energy window optimization for quantitative tasks that includes the effects of model-mismatch on bias: application to Y-90 bremsstrahlung SPECT imaging.

Science.gov (United States)

Rong, Xing; Du, Yong; Frey, Eric C

2012-06-21

Quantitative Yttrium-90 ((90)Y) bremsstrahlung single photon emission computed tomography (SPECT) imaging has shown great potential to provide reliable estimates of (90)Y activity distribution for targeted radionuclide therapy dosimetry applications. One factor that potentially affects the reliability of the activity estimates is the choice of the acquisition energy window. In contrast to imaging conventional gamma photon emitters where the acquisition energy windows are usually placed around photopeaks, there has been great variation in the choice of the acquisition energy window for (90)Y imaging due to the continuous and broad energy distribution of the bremsstrahlung photons. In quantitative imaging of conventional gamma photon emitters, previous methods for optimizing the acquisition energy window assumed unbiased estimators and used the variance in the estimates as a figure of merit (FOM). However, for situations, such as (90)Y imaging, where there are errors in the modeling of the image formation process used in the reconstruction there will be bias in the activity estimates. In (90)Y bremsstrahlung imaging this will be especially important due to the high levels of scatter, multiple scatter, and collimator septal penetration and scatter. Thus variance will not be a complete measure of reliability of the estimates and thus is not a complete FOM. To address this, we first aimed to develop a new method to optimize the energy window that accounts for both the bias due to model-mismatch and the variance of the activity estimates. We applied this method to optimize the acquisition energy window for quantitative (90)Y bremsstrahlung SPECT imaging in microsphere brachytherapy. Since absorbed dose is defined as the absorbed energy from the radiation per unit mass of tissues in this new method we proposed a mass-weighted root mean squared error of the volume of interest (VOI) activity estimates as the FOM. To calculate this FOM, two analytical expressions were

In vivo stepwise multi-photon activation fluorescence imaging of melanin in human skin

Science.gov (United States)

Lai, Zhenhua; Gu, Zetong; Abbas, Saleh; Lowe, Jared; Sierra, Heidy; Rajadhyaksha, Milind; DiMarzio, Charles

2014-03-01

The stepwise multi-photon activated fluorescence (SMPAF) of melanin is a low cost and reliable method of detecting melanin because the activation and excitation can be a continuous-wave (CW) mode near infrared (NIR) laser. Our previous work has demonstrated the melanin SMPAF images in sepia melanin, mouse hair, and mouse skin. In this study, we show the feasibility of using SMPAF to detect melanin in vivo. in vivo melanin SMPAF images of normal skin and benign nevus are demonstrated. SMPAF images add specificity for melanin detection than MPFM images and CRM images. Melanin SMPAF is a promising technology to enable early detection of melanoma for dermatologists.

Fueling and Imaging Brain Activation

Directory of Open Access Journals (Sweden)

Gerald A Dienel

2012-05-01

Full Text Available Metabolic signals are used for imaging and spectroscopic studies of brain function and disease and to elucidate the cellular basis of neuroenergetics. The major fuel for activated neurons and the models for neuron–astrocyte interactions have been controversial because discordant results are obtained in different experimental systems, some of which do not correspond to adult brain. In rats, the infrastructure to support the high energetic demands of adult brain is acquired during postnatal development and matures after weaning. The brain's capacity to supply and metabolize glucose and oxygen exceeds demand over a wide range of rates, and the hyperaemic response to functional activation is rapid. Oxidative metabolism provides most ATP, but glycolysis is frequently preferentially up-regulated during activation. Underestimation of glucose utilization rates with labelled glucose arises from increased lactate production, lactate diffusion via transporters and astrocytic gap junctions, and lactate release to blood and perivascular drainage. Increased pentose shunt pathway flux also causes label loss from C1 of glucose. Glucose analogues are used to assay cellular activities, but interpretation of results is uncertain due to insufficient characterization of transport and phosphorylation kinetics. Brain activation in subjects with low blood-lactate levels causes a brain-to-blood lactate gradient, with rapid lactate release. In contrast, lactate flooding of brain during physical activity or infusion provides an opportunistic, supplemental fuel. Available evidence indicates that lactate shuttling coupled to its local oxidation during activation is a small fraction of glucose oxidation. Developmental, experimental, and physiological context is critical for interpretation of metabolic studies in terms of theoretical models.

Fueling and imaging brain activation

Science.gov (United States)

Dienel, Gerald A

2012-01-01

Metabolic signals are used for imaging and spectroscopic studies of brain function and disease and to elucidate the cellular basis of neuroenergetics. The major fuel for activated neurons and the models for neuron–astrocyte interactions have been controversial because discordant results are obtained in different experimental systems, some of which do not correspond to adult brain. In rats, the infrastructure to support the high energetic demands of adult brain is acquired during postnatal development and matures after weaning. The brain's capacity to supply and metabolize glucose and oxygen exceeds demand over a wide range of rates, and the hyperaemic response to functional activation is rapid. Oxidative metabolism provides most ATP, but glycolysis is frequently preferentially up-regulated during activation. Underestimation of glucose utilization rates with labelled glucose arises from increased lactate production, lactate diffusion via transporters and astrocytic gap junctions, and lactate release to blood and perivascular drainage. Increased pentose shunt pathway flux also causes label loss from C1 of glucose. Glucose analogues are used to assay cellular activities, but interpretation of results is uncertain due to insufficient characterization of transport and phosphorylation kinetics. Brain activation in subjects with low blood-lactate levels causes a brain-to-blood lactate gradient, with rapid lactate release. In contrast, lactate flooding of brain during physical activity or infusion provides an opportunistic, supplemental fuel. Available evidence indicates that lactate shuttling coupled to its local oxidation during activation is a small fraction of glucose oxidation. Developmental, experimental, and physiological context is critical for interpretation of metabolic studies in terms of theoretical models. PMID:22612861

Magnetic Resonance Imaging Including Magnetic Resonance Cholangiopancreatography for Tumor Localization and Therapy Planning in Malignant Hilar Obstructions

International Nuclear Information System (INIS)

Haenninen, E.L.

2005-01-01

PURPOSE: To assess image quality and overall accuracy of magnetic resonance imaging (MRI), including two magnetic cholangiopancreatography (MRCP) techniques, for the diagnostics and preoperative work-up of malignant hilar obstructions. MATERIAL AND METHODS: Thirty-one patients with malignant hilar obstructions (hilar cholangiocarcinoma, n=30; hepatocellular carcinoma, n=1) received MRCP by two techniques (single-shot thick-slab and multisection thin-slice MRCP) and unenhanced and contrast material-enhanced MRI. MR assessment included the evaluation of image quality and visualization of bile ducts (5-point scale), and the classification of tumor status. MR results were subsequently correlated with the results from surgery and pathology. RESULTS: The maximum intensity projections of multisection thin-slice MRCP had significantly more artifacts compared to MRCP in the single-shot thick-slab technique, and overall image quality of single-shot thick-slab MRCP was rated significantly superior compared to multisection thin-slice MRCP (4.4 ± 0.7 and 4.1 ± 0.9, respectively). Moreover, ductal visualization of different parts of the biliary system was rated superior with single-shot thick-slab MRCP. In contrast, the original data from multisection thin slice MRCP facilitated visualization of periductal lesions and adjacent structures. Overall MR accuracy for the assessment of tumor status, periductal infiltration, and lymph node metastases was 90%, 87%, and 66%, respectively. CONCLUSION: For evaluation of malignant hilar obstructions, MRCP by the single-shot thick-slab technique had superior image quality and fewer artifacts; in contrast, besides sole biliary visualization, multisection MRCP depicted complementary adjacent parenchymal and periductal structures. We therefore recommend MRI, with a combination of both MRCP techniques, for the diagnostic work-up and therapy planning of malignant hilar obstructions

POTENTIALS OF IMAGE BASED ACTIVE RANGING TO CAPTURE DYNAMIC SCENES

Directory of Open Access Journals (Sweden)

B. Jutzi

2012-09-01

Full Text Available Obtaining a 3D description of man-made and natural environments is a basic task in Computer Vision and Remote Sensing. To this end, laser scanning is currently one of the dominating techniques to gather reliable 3D information. The scanning principle inherently needs a certain time interval to acquire the 3D point cloud. On the other hand, new active sensors provide the possibility of capturing range information by images with a single measurement. With this new technique image-based active ranging is possible which allows capturing dynamic scenes, e.g. like walking pedestrians in a yard or moving vehicles. Unfortunately most of these range imaging sensors have strong technical limitations and are not yet sufficient for airborne data acquisition. It can be seen from the recent development of highly specialized (far-range imaging sensors – so called flash-light lasers – that most of the limitations could be alleviated soon, so that future systems will be equipped with improved image size and potentially expanded operating range. The presented work is a first step towards the development of methods capable for application of range images in outdoor environments. To this end, an experimental setup was set up for investigating these proposed possibilities. With the experimental setup a measurement campaign was carried out and first results will be presented within this paper.

Tracking molecular dynamics without tracking: image correlation of photo-activation microscopy

International Nuclear Information System (INIS)

Pandžić, Elvis; Rossy, Jérémie; Gaus, Katharina

2015-01-01

Measuring protein dynamics in the plasma membrane can provide insights into the mechanisms of receptor signaling and other cellular functions. To quantify protein dynamics on the single molecule level over the entire cell surface, sophisticated approaches such as single particle tracking (SPT), photo-activation localization microscopy (PALM) and fluctuation-based analysis have been developed. However, analyzing molecular dynamics of fluorescent particles with intermittent excitation and low signal-to-noise ratio present at high densities has remained a challenge. We overcame this problem by applying spatio-temporal image correlation spectroscopy (STICS) analysis to photo-activated (PA) microscopy time series. In order to determine under which imaging conditions this approach is valid, we simulated PA images of diffusing particles in a homogeneous environment and varied photo-activation, reversible blinking and irreversible photo-bleaching rates. Further, we simulated data with high particle densities that populated mobile objects (such as adhesions and vesicles) that often interfere with STICS and fluctuation-based analysis. We demonstrated in experimental measurements that the diffusion coefficient of the epidermal growth factor receptor (EGFR) fused to PAGFP in live COS-7 cells can be determined in the plasma membrane and revealed differences in the time-dependent diffusion maps between wild-type and mutant Lck in activated T cells. In summary, we have developed a new analysis approach for live cell photo-activation microscopy data based on image correlation spectroscopy to quantify the spatio-temporal dynamics of single proteins. (paper)

Tracking molecular dynamics without tracking: image correlation of photo-activation microscopy

Science.gov (United States)

Pandžić, Elvis; Rossy, Jérémie; Gaus, Katharina

2015-03-01

Measuring protein dynamics in the plasma membrane can provide insights into the mechanisms of receptor signaling and other cellular functions. To quantify protein dynamics on the single molecule level over the entire cell surface, sophisticated approaches such as single particle tracking (SPT), photo-activation localization microscopy (PALM) and fluctuation-based analysis have been developed. However, analyzing molecular dynamics of fluorescent particles with intermittent excitation and low signal-to-noise ratio present at high densities has remained a challenge. We overcame this problem by applying spatio-temporal image correlation spectroscopy (STICS) analysis to photo-activated (PA) microscopy time series. In order to determine under which imaging conditions this approach is valid, we simulated PA images of diffusing particles in a homogeneous environment and varied photo-activation, reversible blinking and irreversible photo-bleaching rates. Further, we simulated data with high particle densities that populated mobile objects (such as adhesions and vesicles) that often interfere with STICS and fluctuation-based analysis. We demonstrated in experimental measurements that the diffusion coefficient of the epidermal growth factor receptor (EGFR) fused to PAGFP in live COS-7 cells can be determined in the plasma membrane and revealed differences in the time-dependent diffusion maps between wild-type and mutant Lck in activated T cells. In summary, we have developed a new analysis approach for live cell photo-activation microscopy data based on image correlation spectroscopy to quantify the spatio-temporal dynamics of single proteins.

Validity of Estimation of Pelvic Floor Muscle Activity from Transperineal Ultrasound Imaging in Men.

Directory of Open Access Journals (Sweden)

Ryan E Stafford

Full Text Available To investigate the relationship between displacement of pelvic floor landmarks observed with transperineal ultrasound imaging and electromyography of the muscles hypothesised to cause the displacements.Three healthy men participated in this study, which included ultrasound imaging of the mid-urethra, urethra-vesical junction, ano-rectal junction and bulb of the penis. Fine-wire electromyography electrodes were inserted into the puborectalis and bulbocavernosus muscles and a transurethral catheter electrode recorded striated urethral sphincter electromyography. A nasogastric sensor recorded intra-abdominal pressure. Tasks included submaximal and maximal voluntary contractions, and Valsalva. The relationship between each of the parameters measured from ultrasound images and electromyography or intra-abdominal pressure amplitudes was described with nonlinear regression.Strong, non-linear relationships were calculated for each predicted landmark/muscle pair for submaximal contractions (R2-0.87-0.95. The relationships between mid-urethral displacement and striated urethral sphincter electromyography, and bulb of the penis displacement and bulbocavernosus electromyography were strong during maximal contractions (R2-0.74-0.88. Increased intra-abdominal pressure prevented shortening of puborectalis, which resulted in weak relationships between electromyography and anorectal and urethravesical junction displacement during all tasks.Displacement of landmarks in transperineal ultrasound imaging provides meaningful measures of activation of individual pelvic floor muscles in men during voluntary contractions. This method may aid assessment of muscle function or feedback for training.

Nonspecific bowel activity in imaging inflammation with Tc-99m labelled monoclonal anti-NCA-90 Fab' fragment MN3

International Nuclear Information System (INIS)

Ivancevic, V.; Wolter, A.; Munz, D.L.

2001-01-01

Since the Tc-99m labelled monoclonal anti-NCA 90 granulocyte antibody Fab' fragment MN3 (MN3 Fab') might be of interest for imaging abdominal inflammation which could be hampered by nonspecific bowel activity, we prospectively investigated the appearance of bowel activity in MN3 Fab' imaging. Methods: Eighty consecutive patients (age range 12-85 years) referred for suspected nonabdominal, mostly musculoskeletal infection, were included. Abdominal inflammation was excluded clinically and there were no signs of inflammatory bowel disease in the patients' histories. One, 5, and 24 hours after introvenous injection of up to 1.1 GBq of MN3 Fab' planar images of the abdomen were performed. Bowel activity was graded visually using a 5-point scale. Results: The one (N = 80), 5 (N = 79), and 24 (N = 52) hour images revealed 46 (10%), 162 (34%), and 173 (55%) accumulating bowel segments, respectively, in 37 (46%), 69 (87%), and 52 (100%) patients. The mean intensity score per accumulating segment was 1.1, 1.8 and 2.7 (p = 0), respectively. Relative frequencies of appearance of the small intestine were 38%, 57%, and 21%, ileocaecal region 6%, 53%, and 48%, ascending colon 5%, 67%, and 89%, transverse colon 1%, 9%, and 69%, descending colon 8%, 15%, and 67%, and rectosigmoid 0%, 4%, and 38%, respectively. Follow-up investigations in 13 patients revealed diverging uptake patterns. Conclusion: Nonspecific bowel activity is often present in the early and almost always and more intense, in the delayed images. Early imaging at one hour after administration seems feasible, but a loss in sensitivity has to be considered. Thus, nonspecific bowel activity can be anticipated to be a pitfall in imaging abdominal inflammation with MN3 Fab'. (orig.) [de

Research on active imaging information transmission technology of satellite borne quantum remote sensing

Science.gov (United States)

Bi, Siwen; Zhen, Ming; Yang, Song; Lin, Xuling; Wu, Zhiqiang

2017-08-01

According to the development and application needs of Remote Sensing Science and technology, Prof. Siwen Bi proposed quantum remote sensing. Firstly, the paper gives a brief introduction of the background of quantum remote sensing, the research status and related researches at home and abroad on the theory, information mechanism and imaging experiments of quantum remote sensing and the production of principle prototype.Then, the quantization of pure remote sensing radiation field, the state function and squeezing effect of quantum remote sensing radiation field are emphasized. It also describes the squeezing optical operator of quantum light field in active imaging information transmission experiment and imaging experiments, achieving 2-3 times higher resolution than that of coherent light detection imaging and completing the production of quantum remote sensing imaging prototype. The application of quantum remote sensing technology can significantly improve both the signal-to-noise ratio of information transmission imaging and the spatial resolution of quantum remote sensing .On the above basis, Prof.Bi proposed the technical solution of active imaging information transmission technology of satellite borne quantum remote sensing, launched researches on its system composition and operation principle and on quantum noiseless amplifying devices, providing solutions and technical basis for implementing active imaging information technology of satellite borne Quantum Remote Sensing.

Illumination Effect of Laser Light in Foggy Objects Using an Active Imaging System

Energy Technology Data Exchange (ETDEWEB)

Kwon, Seong-Ouk; Park, Seung-Kyu; Ahn, Yong-Jin; Baik, Sung-Hoon; Choi, Young-Soo; Jeong, Kyung-Min [KAERI, Daejeon (Korea, Republic of)

2015-05-15

Active imaging techniques usually provide improved image information when compared to passive imaging techniques. Active vision is a direct visualization technique using an artificial illuminant. Range-gated imaging (RGI) technique is one of active vision technologies. The RGI technique extracts vision information by summing time sliced vision images. In the RGI system, objects are illuminated for ultra-short time by a high intensity illuminant and then the light reflected from objects is captured by a highly sensitive image sensor with the exposure of ultra-short time. The Range-gated imaging is an emerging technology in the field of surveillance for security application, especially in the visualization of darken night or foggy environment. Although RGI viewing was discovered in the 1960's, this technology is currently more applicable by virtue of the rapid development of optical and sensor technologies, such as highly sensitive imaging sensor and ultra-short pulse laser light. Especially, this system can be adopted in robot-vision system by virtue of the compact system configuration. During the past decades, several applications of this technology have been applied in target recognition and in harsh environments, such as fog, underwater vision. Also, this technology has been demonstrated range imaging based on range-gated imaging. Laser light having a short pulse width is usually used for the range-gated imaging system. In this paper, an illumination effect of laser light in foggy objects is studied using a range-gated imaging system. The used imaging system consists of an ultra-short pulse (0.35 ns) laser light and a gated imaging sensor. The experiment is carried out to monitor objects in a box filled by fog. In this paper, the effects by fog particles in range-gated imaging technique are studied. Edge blurring and range distortion are the generated by fog particles.

Illumination Effect of Laser Light in Foggy Objects Using an Active Imaging System

International Nuclear Information System (INIS)

Kwon, Seong-Ouk; Park, Seung-Kyu; Ahn, Yong-Jin; Baik, Sung-Hoon; Choi, Young-Soo; Jeong, Kyung-Min

2015-01-01

Active imaging techniques usually provide improved image information when compared to passive imaging techniques. Active vision is a direct visualization technique using an artificial illuminant. Range-gated imaging (RGI) technique is one of active vision technologies. The RGI technique extracts vision information by summing time sliced vision images. In the RGI system, objects are illuminated for ultra-short time by a high intensity illuminant and then the light reflected from objects is captured by a highly sensitive image sensor with the exposure of ultra-short time. The Range-gated imaging is an emerging technology in the field of surveillance for security application, especially in the visualization of darken night or foggy environment. Although RGI viewing was discovered in the 1960's, this technology is currently more applicable by virtue of the rapid development of optical and sensor technologies, such as highly sensitive imaging sensor and ultra-short pulse laser light. Especially, this system can be adopted in robot-vision system by virtue of the compact system configuration. During the past decades, several applications of this technology have been applied in target recognition and in harsh environments, such as fog, underwater vision. Also, this technology has been demonstrated range imaging based on range-gated imaging. Laser light having a short pulse width is usually used for the range-gated imaging system. In this paper, an illumination effect of laser light in foggy objects is studied using a range-gated imaging system. The used imaging system consists of an ultra-short pulse (0.35 ns) laser light and a gated imaging sensor. The experiment is carried out to monitor objects in a box filled by fog. In this paper, the effects by fog particles in range-gated imaging technique are studied. Edge blurring and range distortion are the generated by fog particles

CMOS Active-Pixel Image Sensor With Simple Floating Gates

Science.gov (United States)

Fossum, Eric R.; Nakamura, Junichi; Kemeny, Sabrina E.

1996-01-01

Experimental complementary metal-oxide/semiconductor (CMOS) active-pixel image sensor integrated circuit features simple floating-gate structure, with metal-oxide/semiconductor field-effect transistor (MOSFET) as active circuit element in each pixel. Provides flexibility of readout modes, no kTC noise, and relatively simple structure suitable for high-density arrays. Features desirable for "smart sensor" applications.

Non-invasive In Vivo Fluorescence Optical Imaging of Inflammatory MMP Activity Using an Activatable Fluorescent Imaging Agent.

Science.gov (United States)

Schwenck, Johannes; Maier, Florian C; Kneilling, Manfred; Wiehr, Stefan; Fuchs, Kerstin

2017-05-08

This paper describes a non-invasive method for imaging matrix metalloproteinases (MMP)-activity by an activatable fluorescent probe, via in vivo fluorescence optical imaging (OI), in two different mouse models of inflammation: a rheumatoid arthritis (RA) and a contact hypersensitivity reaction (CHR) model. Light with a wavelength in the near infrared (NIR) window (650 - 950 nm) allows a deeper tissue penetration and minimal signal absorption compared to wavelengths below 650 nm. The major advantages using fluorescence OI is that it is cheap, fast and easy to implement in different animal models. Activatable fluorescent probes are optically silent in their inactivated states, but become highly fluorescent when activated by a protease. Activated MMPs lead to tissue destruction and play an important role for disease progression in delayed-type hypersensitivity reactions (DTHRs) such as RA and CHR. Furthermore, MMPs are the key proteases for cartilage and bone degradation and are induced by macrophages, fibroblasts and chondrocytes in response to pro-inflammatory cytokines. Here we use a probe that is activated by the key MMPs like MMP-2, -3, -9 and -13 and describe an imaging protocol for near infrared fluorescence OI of MMP activity in RA and control mice 6 days after disease induction as well as in mice with acute (1x challenge) and chronic (5x challenge) CHR on the right ear compared to healthy ears.

Magnetic resonance imaging of the small bowel in children with idiopathic inflammatory bowel disease: evaluation of disease activity

International Nuclear Information System (INIS)

Alexopoulou, Efthymia; Loggitsi, Dimitra; Economopoulos, Nikos; Papakonstantinou, Olympia; Kelekis, Nikolaos L.; Roma, Eleftheria; Panagiotou, Ioanna; Pahoula, Ioanna

2009-01-01

Examinations using ionizing radiation are frequently used in the evaluation of disease activity in children affected by idiopathic inflammatory bowel disease (IBD). To develop an MR imaging protocol without the need for fluoroscopic insertion of an enteral tube and to assess the disease activity in children with IBD. Included in the study were 37 children (22 girls and 15 boys; age range 7-15 years, mean 11.67 years) with IBD who underwent MR imaging of the small bowel. Of these 37 children, 32 had Crohn disease and 5 had indeterminate colitis. A water solution containing herbal fibres was administered orally or through a nasogastric tube. Patients were imaged on a 1.5-T MR scanner with T1-weighted and Τ2-weighted sequences followed by a dynamic study using 3-D T1-W images after intravenous administration of gadolinium. The percentage enhancement of the bowel wall was significantly increased in patients with abnormal C-reactive protein (CRP) values compared to patients with CRP values in the normal range (P<0.001). A relatively weak but significant correlation between percentage enhancement of the bowel wall and CRP values was noted during all phases of enhancement. This MR imaging protocol is a safe and well-tolerated method for evaluating disease activity and extraintestinal manifestations of IBD in children. (orig.)

Magnetic resonance imaging of the small bowel in children with idiopathic inflammatory bowel disease: evaluation of disease activity

Energy Technology Data Exchange (ETDEWEB)

Alexopoulou, Efthymia; Loggitsi, Dimitra; Economopoulos, Nikos; Papakonstantinou, Olympia; Kelekis, Nikolaos L. [National and Kapodistrian University of Athens, General University Hospital, Second Department of Radiology, Athens (Greece); Roma, Eleftheria; Panagiotou, Ioanna; Pahoula, Ioanna [National and Kapodistrian University of Athens, Aghia Sofia Children' s Hospital, First Department of Paediatrics, Athens (Greece)

2009-08-15

Examinations using ionizing radiation are frequently used in the evaluation of disease activity in children affected by idiopathic inflammatory bowel disease (IBD). To develop an MR imaging protocol without the need for fluoroscopic insertion of an enteral tube and to assess the disease activity in children with IBD. Included in the study were 37 children (22 girls and 15 boys; age range 7-15 years, mean 11.67 years) with IBD who underwent MR imaging of the small bowel. Of these 37 children, 32 had Crohn disease and 5 had indeterminate colitis. A water solution containing herbal fibres was administered orally or through a nasogastric tube. Patients were imaged on a 1.5-T MR scanner with T1-weighted and {tau}2-weighted sequences followed by a dynamic study using 3-D T1-W images after intravenous administration of gadolinium. The percentage enhancement of the bowel wall was significantly increased in patients with abnormal C-reactive protein (CRP) values compared to patients with CRP values in the normal range (P<0.001). A relatively weak but significant correlation between percentage enhancement of the bowel wall and CRP values was noted during all phases of enhancement. This MR imaging protocol is a safe and well-tolerated method for evaluating disease activity and extraintestinal manifestations of IBD in children. (orig.)

Imaging TCR-Dependent NFAT-Mediated T-Cell Activation with Positron Emission Tomography In Vivo

Directory of Open Access Journals (Sweden)

Vladimir Ponomarev

2001-01-01

Full Text Available A noninvasive method for molecular imaging of T-cell activity in vivo would be of considerable value. It would aid in understanding the role of specific genes and signal transduction pathways in the course of normal and pathologic immune responses, could elucidate temporal dynamics and immune regulation at different stages of disease and following therapy. We developed and assessed a novel method for monitoring the T-cell receptor (TCR -dependent nuclear factor of activated T cells (NFAT -mediated activation of T cells by optical fluorescence imaging (OFI and positron emission tomography (PET. The herpes simplex virus type 1 thymidine kinase/green fluorescent protein [HSV1-tk/GFP (TKGFP ] dual reporter gene was used to monitor NFAT-mediated transcriptional activation in human Jurkat cells. A recombinant retrovirus bearing the NFAT-TKGFP reporter system was constructed in which the TKGFP reporter gene was placed under control of an artificial cis-acting NFAT-specific enhancer. Transduced Jurkat cells were used to establish subcutaneous infiltrates in nude rats. We demonstrated that noninvasive OR and nuclear imaging of T-cell activation is feasible using the NFAT-TKGFP reporter system. PET imaging with [124]FIAU using the NFAT-TKGFP reporter system is sufficiently sensitive to detect T-cell activation in vivo. PET images were confirmed by independent measurements of T-cell activation (e.g., CD69 and induction of GFP fluorescence. PET imaging of TCR-induced NFAT-dependent transcriptional activity may be useful in the assessment of T cell responses, T-cell-based adoptive therapies, vaccination strategies and immunosuppressive drugs.

Evaluation of dual γ-ray imager with active collimator using various types of scintillators.

Science.gov (United States)

Lee, Wonho; Lee, Taewoong; Jeong, Manhee; Kim, Ho Kyung

2011-10-01

The performance of a specialized dual γ-ray imager using both mechanical and electronic collimation was evaluated by Monte Carlo simulation (MCNP5). The dual imager consisted of an active collimator and a planar detector that were made from scintillators. The active collimator served not only as a coded aperture for mechanical collimation but also as a first detector for electronic collimation. Therefore, a single system contained both mechanical and electronic collimation. Various types of scintillators were tested and compared with each other in terms of their angular resolution, efficiency, and background noise. In general, a BGO active collimator had the best mechanical collimation performance, and an LaCl₃(Ce) active collimator provided the best electronic collimation performance. However, for low radiation energies, the mechanical collimation images made from both scintillators showed the same quality, and, for high radiation energies, electronic collimation images made from both scintillators also show similar quality. Therefore, if mechanical collimation is used to detect low-energy radiation and electronic collimation is applied to reconstruct a high-energy source, either LaCl₃(Ce) or BGO would be appropriate for the active collimator of a dual γ-ray imager. These results broaden the choice of scintillators for the active collimator of the dual γ-ray imager, which makes it possible to consider other factors, such as machinability and cost, in making the imager. As a planar detector, BGO showed better performance than other scintillators since its radiation detection efficiency was highest of all. Copyright © 2011 Elsevier Ltd. All rights reserved.

Systematic review: Use of ultrasonography, computed tomography and magnetic resonance imaging for the diagnosis, assessment of activity and abdominal complications of Crohn's disease

OpenAIRE

Panes , Julian; Bouzas , Rosa; García-Sánchez , Valle; Chaparro , María; Pérez-Gisbert , Javier; Martínez De Guereñu , Blanca; Mendoza , Juan Luis; Paredes , José María; Quiroga , Sergi; Ripollés , Tomás; Rimola , Jordi

2011-01-01

Abstract Backgroud: Cross-sectional imaging techniques, including ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI), are increasingly used for evaluation of Crohn?s disease (CD). Aim: To perform an assessment of the diagnostic accuracy of cross-sectional imaging techniques for diagnosis of CD, evaluation of disease extension and activity, and diagnosis of complications, and to provide recommendations for their optimal use. Methods: Relevant ...

Focal Pancreatitis Mimicking Pancreatic Mass: Magnetic Resonance Imaging (MRI)/Magnetic Resonance Cholangiopancreatography (MRCP) Findings Including Diffusion-Weighted MRI

International Nuclear Information System (INIS)

Momtahen, A.J.; Balci, N.C.; Alkaade, S.; Akduman, E.I.; Burton, F.R.

2008-01-01

Background: Focal pancreatitis (FP) is a confined inflammation that mimics a pancreatic mass. Its imaging diagnosis is important to avoid unnecessary procedures. Purpose: To describe the spectrum of magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted MRI (DWI) findings of focal pancreatitis mimicking pancreatic masses. Material and Methods: Findings of MRI/MRCP including DWI with a b value of 0 and 600 s/mm2 in 14 patients with pancreatic masses on MRI were retrospectively reviewed and compared to normal pancreas in 14 patients as a control group. Results: FP revealed hypointense signal intensity (SI) (3/14), hypo- to isointense SI (7/14), or isointense SI (4/14) on T1-weighted images, and hypointense SI (1/14), isointense SI (5/14), iso- to hyperintense SI (7/14), or hyperintense SI (1/14) on T2-weighted images compared to remaining pancreas (RP). MRCP images revealed dilatation of the common bile duct (CBD) and main pancreatic duct (MPD) (5/14), dilatation of the MPD only (3/14), dilatation of the CBD only (3/14), and normal MPD and CBD (3/14). Both FP and RP revealed three types of time-signal intensity curves: 1) rapid rise to a peak, with a rapid decline (FP=2, RP=4), 2) slow rise to a peak, followed by a slow decline (FP=5, RP=4), and 3) slower rise to a peak, with a slow decline or plateau (FP=7, RP=6). Mean apparent diffusion coefficient (ADC) values for FP and RP were 2.09±0.18 and 2.03±0.2x10 -3 mm 2 /s, respectively. ADC values of FP and RP revealed no significant difference. Conclusion: The spectrum of imaging findings of focal pancreatitis on MRI/MRCP including DWI was described. Findings of FP were not distinctive as compared to the remaining pancreas

Normal and abnormal electrical activation of the heart. Imaging patterns obtained by phase analysis of equilibrium cardiac studies

International Nuclear Information System (INIS)

Pavel, D.; Byrom, E.; Swiryn, S.; Meyer-Pavel, C.; Rosen, K.

1981-01-01

By using a temporal Fourier analysis of gated equilibrium cardiac studies, phase images were obtained. These functional images were analysed qualitatively and quantitatively to determine if specific patterns can be found for normal versus abnormal electrical activation of the heart. The study included eight subjects with normal cardiac function and 24 patients with abnormal electrical activation: eight with left bundle branch block (LBBB), two with right bundle branch block (RBBB), six with Wolff-Parkinson-White syndrome (WPW), one with junctional rhythm, one with spontaneous sustained ventricular tachycardia (VT) (all with normal wall motion), two with chronic transvenous pacemakers, and four with induced sustained VT (all with regional wall motion abnormalities). The results show that the two ventricals have the same mean phase (within +-9 0 ) in normals, but significantly different mean phases in all patients with bundle branch blocks. Of the six WPW patients, three had a distinctive abnormal pattern. The patient with junctional rhythm, those with transvenous pacemakers, and those with VT all had abnormal patterns on the phase image. The phase image is capable of showing differences between patients with electrical activation and a variety of electrical abnormalities. Within the latter category distinct patterns can be associated with each type of abnormality. (author)

Body image and self-esteem among adolescents undergoing an intervention targeting dietary and physical activity behaviors.

Science.gov (United States)

Huang, Jeannie S; Norman, Gregory J; Zabinski, Marion F; Calfas, Karen; Patrick, Kevin

2007-03-01

observed among adolescents undergoing this behavioral intervention. These results suggest that a behavioral intervention directed at improving physical activity and diet habits may be safely undertaken by adolescents, including those who are overweight and at risk for overweight, without adverse psychological consequences. Inclusion of specific elements in the intervention that directly addressed body image and self-esteem issues may have reduced the risk for negative psychological effects.

Towards brain-activity-controlled information retrieval: Decoding image relevance from MEG signals.

Science.gov (United States)

Kauppi, Jukka-Pekka; Kandemir, Melih; Saarinen, Veli-Matti; Hirvenkari, Lotta; Parkkonen, Lauri; Klami, Arto; Hari, Riitta; Kaski, Samuel

2015-05-15

We hypothesize that brain activity can be used to control future information retrieval systems. To this end, we conducted a feasibility study on predicting the relevance of visual objects from brain activity. We analyze both magnetoencephalographic (MEG) and gaze signals from nine subjects who were viewing image collages, a subset of which was relevant to a predetermined task. We report three findings: i) the relevance of an image a subject looks at can be decoded from MEG signals with performance significantly better than chance, ii) fusion of gaze-based and MEG-based classifiers significantly improves the prediction performance compared to using either signal alone, and iii) non-linear classification of the MEG signals using Gaussian process classifiers outperforms linear classification. These findings break new ground for building brain-activity-based interactive image retrieval systems, as well as for systems utilizing feedback both from brain activity and eye movements. Copyright © 2015 Elsevier Inc. All rights reserved.

Research on range-gated laser active imaging seeker

Science.gov (United States)

You, Mu; Wang, PengHui; Tan, DongJie

2013-09-01

Compared with other imaging methods such as millimeter wave imaging, infrared imaging and visible light imaging, laser imaging provides both a 2-D array of reflected intensity data as well as 2-D array of range data, which is the most important data for use in autonomous target acquisition .In terms of application, it can be widely used in military fields such as radar, guidance and fuse. In this paper, we present a laser active imaging seeker system based on range-gated laser transmitter and sensor technology .The seeker system presented here consist of two important part, one is laser image system, which uses a negative lens to diverge the light from a pulse laser to flood illuminate a target, return light is collected by a camera lens, each laser pulse triggers the camera delay and shutter. The other is stabilization gimbals, which is designed to be a rotatable structure both in azimuth and elevation angles. The laser image system consists of transmitter and receiver. The transmitter is based on diode pumped solid-state lasers that are passively Q-switched at 532nm wavelength. A visible wavelength was chosen because the receiver uses a Gen III image intensifier tube with a spectral sensitivity limited to wavelengths less than 900nm.The receiver is image intensifier tube's micro channel plate coupled into high sensitivity charge coupled device camera. The image has been taken at range over one kilometer and can be taken at much longer range in better weather. Image frame frequency can be changed according to requirement of guidance with modifiable range gate, The instantaneous field of views of the system was found to be 2×2 deg. Since completion of system integration, the seeker system has gone through a series of tests both in the lab and in the outdoor field. Two different kinds of buildings have been chosen as target, which is located at range from 200m up to 1000m.To simulate dynamic process of range change between missile and target, the seeker system has

Differences in the Nature of Body Image Disturbances between Female Obese Individuals with versus without a Comorbid Binge Eating Disorder: An Exploratory Study Including Static and Dynamic Aspects of Body Image

Science.gov (United States)

Legenbauer, Tanja; Vocks, Silja; Betz, Sabrina; Puigcerver, Maria Jose Baguena; Benecke, Andrea; Troje, Nikolaus F.; Ruddel, Heinz

2011-01-01

Various components of body image were measured to assess body image disturbances in patients with obesity. To overcome limitations of previous studies, a photo distortion technique and a biological motion distortion device were included to assess static and dynamic aspects of body image. Questionnaires assessed cognitive-affective aspects, bodily…

CMOS active pixel sensor type imaging system on a chip

Science.gov (United States)

Fossum, Eric R. (Inventor); Nixon, Robert (Inventor)

2011-01-01

A single chip camera which includes an .[.intergrated.]. .Iadd.integrated .Iaddend.image acquisition portion and control portion and which has double sampling/noise reduction capabilities thereon. Part of the .[.intergrated.]. .Iadd.integrated .Iaddend.structure reduces the noise that is picked up during imaging.

TWO NOVEL ACM (ACTIVE CONTOUR MODEL) METHODS FOR INTRAVASCULAR ULTRASOUND IMAGE SEGMENTATION

International Nuclear Information System (INIS)

Chen, Chi Hau; Potdat, Labhesh; Chittineni, Rakesh

2010-01-01

One of the attractive image segmentation methods is the Active Contour Model (ACM) which has been widely used in medical imaging as it always produces sub-regions with continuous boundaries. Intravascular ultrasound (IVUS) is a catheter based medical imaging technique which is used for quantitative assessment of atherosclerotic disease. Two methods of ACM realizations are presented in this paper. The gradient descent flow based on minimizing energy functional can be used for segmentation of IVUS images. However this local operation alone may not be adequate to work with the complex IVUS images. The first method presented consists of basically combining the local geodesic active contours and global region-based active contours. The advantage of combining the local and global operations is to allow curves deforming under the energy to find only significant local minima and delineate object borders despite noise, poor edge information and heterogeneous intensity profiles. Results for this algorithm are compared to standard techniques to demonstrate the method's robustness and accuracy. In the second method, the energy function is appropriately modified and minimized using a Hopfield neural network. Proper modifications in the definition of the bias of the neurons have been introduced to incorporate image characteristics. The method overcomes distortions in the expected image pattern, such as due to the presence of calcium, and employs a specialized structure of the neural network and boundary correction schemes which are based on a priori knowledge about the vessel geometry. The presented method is very fast and has been evaluated using sequences of IVUS frames.

Myocardial perfusion imaging in Denmark: activity from 1997 to 2001 and current practice

DEFF Research Database (Denmark)

Petersen, Claus Leth; Kjaer, Andreas

2003-01-01

, and the survey thus covers all MPI performed in Denmark during the period in question. The number of MPI studies (examined patients) was 2,531 in 1997 (0.47 MPI/1,000/year) and 4,961 (0.93 MPI/1,000/year) in 2001, which is a doubling in activity in 5 years. Nineteen (95%) of the Danish departments performed MPI...... in 2001, and 14 (74%) of these reported that activity had increased over the past 5 years. MPI activity was unevenly distributed between hospitals and regions. In 2001, the university hospitals in the central Copenhagen region (capital) accounted for the highest MPI activity (2.00/1,000/year), while......A questionnaire was sent to all departments of nuclear medicine in Denmark (n=20) asking for details of myocardial perfusion imaging (MPI), including the number of patients examined each year from 1997 to 2001 and the current clinical and technical practice. All (100%) departments replied...

Noninvasive Evaluation of Cellular Proliferative Activity in Brain Neurogenic Regions in Rats under Depression and Treatment by Enhanced [18F]FLT-PET Imaging.

Science.gov (United States)

Tamura, Yasuhisa; Takahashi, Kayo; Takata, Kumi; Eguchi, Asami; Yamato, Masanori; Kume, Satoshi; Nakano, Masayuki; Watanabe, Yasuyoshi; Kataoka, Yosky

2016-08-03

Neural stem cells in two neurogenic regions, the subventricular zone and the subgranular zone (SGZ) of the hippocampal dentate gyrus, can divide and produce new neurons throughout life. Hippocampal neurogenesis is related to emotions, including depression/anxiety, and the therapeutic effects of antidepressants, as well as learning and memory. The establishment of in vivo imaging for proliferative activity of neural stem cells in the SGZ might be used to diagnose depression and to monitor the therapeutic efficacy of antidepressants. Positron emission tomography (PET) imaging with 3'-deoxy-3'-[(18)F]fluoro-l-thymidine ([(18)F]FLT) has been studied to allow visualization of proliferative activity in two neurogenic regions of adult mammals; however, the PET imaging has not been widely used because of lower accumulation of [(18)F]FLT, which does not allow quantitative assessment of the decline in cellular proliferative activity in the SGZ under the condition of depression. We report the establishment of an enhanced PET imaging method with [(18)F]FLT combined with probenecid, an inhibitor of drug transporters at the blood-brain barrier, which can allow the quantitative visualization of neurogenic activity in rats. Enhanced PET imaging allowed us to evaluate reduced cell proliferation in the SGZ of rats with corticosterone-induced depression, and further the recovery of proliferative activity in rats under treatment with antidepressants. This enhanced [(18)F]FLT-PET imaging technique with probenecid can be used to assess the dynamic alteration of neurogenic activity in the adult mammalian brain and may also provide a means for objective diagnosis of depression and monitoring of the therapeutic effect of antidepressant treatment. Adult hippocampal neurogenesis may play a role in major depression and antidepressant therapy. Establishment of in vivo imaging for hippocampal neurogenic activity may be useful to diagnose depression and monitor the therapeutic efficacy of

Digital imaging information technology for biospeckle activity assessment relative to bacteria and parasites.

Science.gov (United States)

Ramírez-Miquet, Evelio E; Cabrera, Humberto; Grassi, Hilda C; de J Andrades, Efrén; Otero, Isabel; Rodríguez, Dania; Darias, Juan G

2017-08-01

This paper reports on the biospeckle processing of biological activity using a visualization scheme based upon the digital imaging information technology. Activity relative to bacterial growth in agar plates and to parasites affected by a drug is monitored via the speckle patterns generated by a coherent source incident on the microorganisms. We present experimental results to demonstrate the potential application of this methodology for following the activity in time. The digital imaging information technology is an alternative visualization enabling the study of speckle dynamics, which is correlated to the activity of bacteria and parasites. In this method, the changes in Red-Green-Blue (RGB) color component density are considered as markers of the growth of bacteria and parasites motility in presence of a drug. The RGB data was used to generate a two-dimensional surface plot allowing an analysis of color distribution on the speckle images. The proposed visualization is compared to the outcomes of the generalized differences and the temporal difference. A quantification of the activity is performed using a parameterization of the temporal difference method. The adopted digital image processing technique has been found suitable to monitor motility and morphological changes in the bacterial population over time and to detect and distinguish a short term drug action on parasites.

Optimal Design and Real Time Implementation of Autonomous Microgrid Including Active Load

OpenAIRE

Mohamed A. Hassan; Muhammed Y. Worku; Mohamed A. Abido

2018-01-01

Controller gains and power-sharing parameters are the main parameters affect the dynamic performance of the microgrid. Considering an active load to the autonomous microgrid, the stability problem will be more involved. In this paper, the active load effect on microgrid dynamic stability is explored. An autonomous microgrid including three inverter-based distributed generations (DGs) with an active load is modeled and the associated controllers are designed. Controller gains of the inverters ...

Multiple Active Contours Driven by Particle Swarm Optimization for Cardiac Medical Image Segmentation

Science.gov (United States)

Cruz-Aceves, I.; Aviña-Cervantes, J. G.; López-Hernández, J. M.; González-Reyna, S. E.

2013-01-01

This paper presents a novel image segmentation method based on multiple active contours driven by particle swarm optimization (MACPSO). The proposed method uses particle swarm optimization over a polar coordinate system to increase the energy-minimizing capability with respect to the traditional active contour model. In the first stage, to evaluate the robustness of the proposed method, a set of synthetic images containing objects with several concavities and Gaussian noise is presented. Subsequently, MACPSO is used to segment the human heart and the human left ventricle from datasets of sequential computed tomography and magnetic resonance images, respectively. Finally, to assess the performance of the medical image segmentations with respect to regions outlined by experts and by the graph cut method objectively and quantifiably, a set of distance and similarity metrics has been adopted. The experimental results demonstrate that MACPSO outperforms the traditional active contour model in terms of segmentation accuracy and stability. PMID:23762177

MR arthrography including abduction and external rotation images in the assessment of atraumatic multidirectional instability of the shoulder

Energy Technology Data Exchange (ETDEWEB)

Schaeffeler, Christoph [Technische Universitaet Muenchen, Department of Radiology, Munich (Germany); Kantonsspital Graubuenden, Musculoskeletal Imaging, Chur (Switzerland); Waldt, Simone; Bauer, Jan S.; Rummeny, Ernst J.; Woertler, Klaus [Technische Universitaet Muenchen, Department of Radiology, Munich (Germany); Kirchhoff, Chlodwig [Technische Universitaet Muenchen, Department of Traumatology, Munich (Germany); Haller, Bernhard [Technische Universitaet Muenchen, Institute for Medical Statistics and Epidemiology, Munich (Germany); Schroeder, Michael [Center for Sports Orthopedics and Medicine, Orthosportiv, Munich (Germany); Imhoff, Andreas B. [Technische Universitaet Muenchen, Department of Orthopedic Sports Medicine, Munich (Germany)

2014-06-15

To evaluate diagnostic signs and measurements in the assessment of capsular redundancy in atraumatic multidirectional instability (MDI) of the shoulder on MR arthrography (MR-A) including abduction/external rotation (ABER) images. Twenty-one MR-A including ABER position of 20 patients with clinically diagnosed MDI and 17 patients without instability were assessed by three radiologists. On ABER images, presence of a layer of contrast between the humeral head (HH) and the anteroinferior glenohumeral ligament (AIGHL) (crescent sign) and a triangular-shaped space between the HH, AIGHL and glenoid (triangle sign) were evaluated; centring of the HH was measured. Anterosuperior herniation of the rotator interval (RI) capsule and glenoid version were determined on standard imaging planes. The crescent sign had a sensitivity of 57 %/62 %/48 % (observers 1/2/3) and specificity of 100 %/100 %/94 % in the diagnosis of MDI. The triangle sign had a sensitivity of 48 %/57 %/48 % and specificity of 94 %/94 %/100 %. The combination of both signs had a sensitivity of 86 %/90 %/81 % and specificity of 94 %/94 %/94 %. A positive triangle sign was significantly associated with decentring of the HH. Measurements of RI herniation, RI width and glenoid were not significantly different between both groups. Combined assessment of redundancy signs on ABER position MR-A allows for accurate differentiation between patients with atraumatic MDI and patients with clinically stable shoulders; measurements on standard imaging planes appear inappropriate. (orig.)

Unified theory of dislocation motion including thermal activation and inertial effects

International Nuclear Information System (INIS)

Isaac, R.D.; Granato, A.V.

1979-01-01

Transition-state rate theory has generally been used to explain the temperature dependence of the flow stress of a crystal. However, the existence of a change in the flow stress during the superconducting transition indicates the presence of inertial effects in which dislocations overcome obstacles mechanically rather than thermally. It is shown here that the thermally activated and the inertial overcoming of obstacles are not unrelated but can both be derived from principles of stochastic motion. This leads to a theory of dislocation motion that includes both thermal activation and inertial effects. It is also shown that a distribution of activation energies must be considered to account for the experimental data

Calcium imaging of basal forebrain activity during innate and learned behaviors

Directory of Open Access Journals (Sweden)

Thomas Clarke Harrison

2016-05-01

Full Text Available The basal forebrain (BF plays crucial roles in arousal, attention, and memory, and its impairment is associated with a variety of cognitive deficits. The BF consists of cholinergic, GABAergic, and glutamatergic neurons. Electrical or optogenetic stimulation of BF cholinergic neurons enhances cortical processing and behavioral performance, but the natural activity of these cells during behavior is only beginning to be characterized. Even less is known about GABAergic and glutamatergic neurons. Here, we performed microendoscopic calcium imaging of BF neurons as mice engaged in spontaneous behaviors in their home cages (innate or performed a go/no-go auditory discrimination task (learned. Cholinergic neurons were consistently excited during movement, including running and licking, but GABAergic and glutamatergic neurons exhibited diverse responses. All cell types were activated by overt punishment, either inside or outside of the discrimination task. These findings reveal functional similarities and distinctions between BF cell types during both spontaneous and task-related behaviors.

Cardiac imaging in RASopathies/mitogen activated protein kinase syndromes

Directory of Open Access Journals (Sweden)

Rita Gravino

2014-07-01

Full Text Available RASopathies include a spectrum of disorders due to dysregulation of RAS/mitogen activated protein kinase pathway that plays an essential role in the control of the cell cycle and differentiation. As a consequence, its dysregulation has profound developmental consequences, in particular cardiac malformations. RASopathies with cardiac features are: Noonan syndrome, multiple lentigines syndrome, cardio-faciocutaneous syndrome, Costello syndrome, neurofibromatosis- 1, Legius syndrome, neurofibromatosis- Noonan syndrome. The former syndromes are associated with a high rate of cardiac involvement (60-85% and 12 genes: PTPN11, SOS1, RAF1, KRAS, HRAS, BRAF, MEK1/MAP2K1, MEK2/MAP2K2, NRAS, SHOC2, CBL and SPRED1. Although the majority of these diseases are readily distinguishable in clinical terms, an integrated imaging study of the cardiac condition associated to RASopathies helps to better define risk assessment, surveillance, and management of these patients.

Is Being a Boy and Feeling Fat a Barrier for Physical Activity? The Association between Body Image, Gender and Physical Activity among Adolescents

NARCIS (Netherlands)

Kopcakova, Jaroslava; Veselska, Zuzana Dankulincova; Geckova, Andrea Madarasova; van Dijk, Jitse P.; Reijneveld, Sijmen A.

2014-01-01

Regular physical activity leads to physical and mental health benefits. Previous studies have shown physical activity to be associated with body image and gender. The aim of this cross-sectional study was to explore the associations of body image with physical activity of adolescents and whether

Diagnostic value of static MR imaging of soft tissue tumours including lesion size, borders and local extend

International Nuclear Information System (INIS)

Tacikowska, M.

2001-01-01

The usefulness of MR imaging in the evaluation of the degree of soft tissue malignancy is widely discussed. The aim of this study was to analyse the diagnostic value of MR imaging in the evaluation of local progression of soft tissue tumours and to analyse the usefulness of MR imaging in the differential diagnosis (malignant versus benign lesions). One hundred and ten patients with soft tissue tumours were examined by MR imaging (60 men and 50 women, aged 16 to 84 years). MR imaging was carried out with an Elscint 2T or 0.5T unit. Surface coils (passive) or circular polarized coils (active) depending on the localisation of the lesions were used with field vision from 20x24 cm or 40x40 cm, matrices 200x256, 256x256, or 22x315, layer thickness from 3 to 10 mm, gap 20-30%. SE T1 sequences (TR = 500 - 800 ms, TE = 15 - 20 ms) and FSE T2 (Tr = 2000-4500 ms, TE = 96-104 ms) were routinely used in at least two planes: transverse, frontal or saggital, and SE T1 sequences were used after administration of gadolinium Gd-DTPA in 0.1 m - 0.2 mmol/kg body weigh doses. The tumour dimensions by MR imaging were compared with the results of histological examination of samples obtained during surgery (65 cases) - the statistical analysis was performed using Student's t-test, with statistically significant difference accepted at p = 0.05 or less. The borders of the lesions were assessed in the entire material and in the group of 65 patients treated surgically. The latter were compared with the results of histological examination after surgery, thus calculating MR sensitivity and specificity. Static imaging is a valuable diagnostic method for preoperative assesment of the local progression of soft tissue tumours, however it is not suitable for differentiating malignant lesions from benign according to tumour size, borders and local extent. (author)

Activation in mesolimbic and visuospatial neural circuits elicited by smoking cues: evidence from functional magnetic resonance imaging.

Science.gov (United States)

Due, Deborah L; Huettel, Scott A; Hall, Warren G; Rubin, David C

2002-06-01

The authors sought to increase understanding of the brain mechanisms involved in cigarette addiction by identifying neural substrates modulated by visual smoking cues in nicotine-deprived smokers. Event-related functional magnetic resonance imaging (fMRI) was used to detect brain activation after exposure to smoking-related images in a group of nicotine-deprived smokers and a nonsmoking comparison group. Subjects viewed a pseudo-random sequence of smoking images, neutral nonsmoking images, and rare targets (photographs of animals). Subjects pressed a button whenever a rare target appeared. In smokers, the fMRI signal was greater after exposure to smoking-related images than after exposure to neutral images in mesolimbic dopamine reward circuits known to be activated by addictive drugs (right posterior amygdala, posterior hippocampus, ventral tegmental area, and medial thalamus) as well as in areas related to visuospatial attention (bilateral prefrontal and parietal cortex and right fusiform gyrus). In nonsmokers, no significant differences in fMRI signal following exposure to smoking-related and neutral images were detected. In most regions studied, both subject groups showed greater activation following presentation of rare target images than after exposure to neutral images. In nicotine-deprived smokers, both reward and attention circuits were activated by exposure to smoking-related images. Smoking cues are processed like rare targets in that they activate attentional regions. These cues are also processed like addictive drugs in that they activate mesolimbic reward regions.

Use of high resolution satellite images for monitoring of earthquakes and volcano activity.

Science.gov (United States)

Arellano-Baeza, Alonso A.

Our studies have shown that the strain energy accumulation deep in the Earth's crust that precedes a strong earthquake can be detected by applying a lineament extraction technique to the high-resolution multispectral satellite images. A lineament is a straight or a somewhat curved feature in a satellite image, which it is possible to detect by a special processing of images based on directional filtering and or Hough transform. We analyzed tens of earthquakes occurred in the Pacific coast of the South America with the Richter scale magnitude ˜4.5, using ASTER/TERRA multispectral satellite images for detection and analysis of changes in the system of lineaments previous to a strong earthquake. All events were located in the regions with small seasonal variations and limited vegetation to facilitate the tracking of features associated with the seismic activity only. It was found that the number and orientation of lineaments changed significantly about one month before an earthquake approximately, and a few months later the system returns to its initial state. This effect increases with the earthquake magnitude. It also was shown that the behavior of lineaments associated to the volcano seismic activity is opposite to that obtained previously for earthquakes. This discrepancy can be explained assuming that in the last case the main reason of earthquakes is compression and accumulation of strength in the Earth's crust due to subduction of tectonic plates, whereas in the first case we deal with the inflation of a volcano edifice due to elevation of pressure and magma intrusion. The results obtained made it possible to include this research as a part of scientific program of Chilean Remote Sensing Satellite mission to be launched in 2010.

An image-free opto-mechanical system for creating virtual environments and imaging neuronal activity in freely moving Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Serge Faumont

Full Text Available Non-invasive recording in untethered animals is arguably the ultimate step in the analysis of neuronal function, but such recordings remain elusive. To address this problem, we devised a system that tracks neuron-sized fluorescent targets in real time. The system can be used to create virtual environments by optogenetic activation of sensory neurons, or to image activity in identified neurons at high magnification. By recording activity in neurons of freely moving C. elegans, we tested the long-standing hypothesis that forward and reverse locomotion are generated by distinct neuronal circuits. Surprisingly, we found motor neurons that are active during both types of locomotion, suggesting a new model of locomotion control in C. elegans. These results emphasize the importance of recording neuronal activity in freely moving animals and significantly expand the potential of imaging techniques by providing a mean to stabilize fluorescent targets.

Body image and physical activity among black university students in ...

African Journals Online (AJOL)

BMI was associated with overweight preoccupation and self-classified weight. Fitness orientation, health evaluation and body areas satisfaction were associated ... Key words: Body image, physical activity, black women and men, South Africa.

Pain anticipation: an activation likelihood estimation meta-analysis of brain imaging studies.

Science.gov (United States)

Palermo, Sara; Benedetti, Fabrizio; Costa, Tommaso; Amanzio, Martina

2015-05-01

The anticipation of pain has been investigated in a variety of brain imaging studies. Importantly, today there is no clear overall picture of the areas that are involved in different studies and the exact role of these regions in pain expectation remains especially unexploited. To address this issue, we used activation likelihood estimation meta-analysis to analyze pain anticipation in several neuroimaging studies. A total of 19 functional magnetic resonance imaging were included in the analysis to search for the cortical areas involved in pain anticipation in human experimental models. During anticipation, activated foci were found in the dorsolateral prefrontal, midcingulate and anterior insula cortices, medial and inferior frontal gyri, inferior parietal lobule, middle and superior temporal gyrus, thalamus, and caudate. Deactivated foci were found in the anterior cingulate, superior frontal gyrus, parahippocampal gyrus and in the claustrum. The results of the meta-analytic connectivity analysis provide an overall view of the brain responses triggered by the anticipation of a noxious stimulus. Such a highly distributed perceptual set of self-regulation may prime brain regions to process information where emotion, action and perception as well as their related subcategories play a central role. Not only do these findings provide important information on the neural events when anticipating pain, but also they may give a perspective into nocebo responses, whereby negative expectations may lead to pain worsening. © 2014 Wiley Periodicals, Inc.

ImageX: new and improved image explorer for astronomical images and beyond

Science.gov (United States)

Hayashi, Soichi; Gopu, Arvind; Kotulla, Ralf; Young, Michael D.

2016-08-01

The One Degree Imager - Portal, Pipeline, and Archive (ODI-PPA) has included the Image Explorer interactive image visualization tool since it went operational. Portal users were able to quickly open up several ODI images within any HTML5 capable web browser, adjust the scaling, apply color maps, and perform other basic image visualization steps typically done on a desktop client like DS9. However, the original design of the Image Explorer required lossless PNG tiles to be generated and stored for all raw and reduced ODI images thereby taking up tens of TB of spinning disk space even though a small fraction of those images were being accessed by portal users at any given time. It also caused significant overhead on the portal web application and the Apache webserver used by ODI-PPA. We found it hard to merge in improvements made to a similar deployment in another project's portal. To address these concerns, we re-architected Image Explorer from scratch and came up with ImageX, a set of microservices that are part of the IU Trident project software suite, with rapid interactive visualization capabilities useful for ODI data and beyond. We generate a full resolution JPEG image for each raw and reduced ODI FITS image before producing a JPG tileset, one that can be rendered using the ImageX frontend code at various locations as appropriate within a web portal (for example: on tabular image listings, views allowing quick perusal of a set of thumbnails or other image sifting activities). The new design has decreased spinning disk requirements, uses AngularJS for the client side Model/View code (instead of depending on backend PHP Model/View/Controller code previously used), OpenSeaDragon to render the tile images, and uses nginx and a lightweight NodeJS application to serve tile images thereby significantly decreasing the Time To First Byte latency by a few orders of magnitude. We plan to extend ImageX for non-FITS images including electron microscopy and radiology scan

Development of a contrast phantom for active millimeter-wave imaging systems

Science.gov (United States)

Barber, Jeffrey; Weatherall, James C.; Brauer, Carolyn S.; Smith, Barry T.

2011-06-01

As the development of active millimeter wave imaging systems continues, it is necessary to validate materials that simulate the expected response of explosives. While physics-based models have been used to develop simulants, it is desirable to image both the explosive and simulant together in a controlled fashion in order to demonstrate success. To this end, a millimeter wave contrast phantom has been created to calibrate image grayscale while controlling the configuration of the explosive and simulant such that direct comparison of their respective returns can be performed. The physics of the phantom are described, with millimeter wave images presented to show successful development of the phantom and simulant validation at GHz frequencies.

Thermal neutron imaging in an active interrogation environment

International Nuclear Information System (INIS)

Vanier, P.E.; Forman, L.; Norman, D.R.

2009-01-01

We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

Imaging Features of Patients Undergoing Active Surveillance for Ductal Carcinoma in Situ.

Science.gov (United States)

Grimm, Lars J; Ghate, Sujata V; Hwang, E Shelley; Soo, Mary Scott

2017-11-01

The aim of this study was to describe the imaging appearance of patients undergoing active surveillance for ductal carcinoma in situ (DCIS). We retrospectively identified 29 patients undergoing active surveillance for DCIS from 2009 to 2014. Twenty-two patients (group 1) refused surgery or were not surgical candidates. Seven patients (group 2) enrolled in a trial of letrozole and deferred surgical excision for 6-12 months. Pathology and imaging results at the initial biopsy and follow-up were recorded. In group 1, the median follow-up was 2.7 years (range: 0.6-13.9 years). Fifteen patients (68%) remained stable. Seven patients (32%) underwent additional biopsies with invasive ductal carcinoma diagnosed in two patients after 3.9 and 3.6 years who developed increasing calcifications and new masses. In group 2, one patient (14%) was upstaged to microinvasive ductal carcinoma at surgery. Among the patients in both groups with calcifications (n = 26), there was no progression to invasive disease among those with stable (50%, 13/26) or decreased (19%, 5/26) calcifications. Among a DCIS active surveillance cohort, invasive disease progression presented as increasing calcifications and a new mass following more than 3.5 years of stable imaging. In contrast, there was no progression to invasive disease among cases of DCIS with stable or decreasing calcifications. Close imaging is a key follow-up component in active surveillance. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Detection of cortical activities on eye movement using functional magnetic resonance imaging

International Nuclear Information System (INIS)

Yoshida, Masaki; Kawai, Kazushige; Kitahara, Kenji; Soulie, D.; Cordoliani, Y.S.; Iba-Zizen, M.T.; Cabanis, E.A.

1997-01-01

Cortical activity during eye movement was examined with functional magnetic resonance imaging. Horizontal saccadic eye movements and smooth pursuit eye movements were elicited in normal subjects. Activity in the frontal eye field was found during both saccadic and smooth pursuit eye movements at the posterior margin of the middle frontal gyrus and in parts of the precentral sulcus and precentral gyrus bordering the middle frontal gyrus (Brodmann's areas 8, 6, and 9). In addition, activity in the parietal eye field was found in the deep, upper margin of the angular gyrus and of the supramarginal gyrus (Brodmann's areas 39 and 40) during saccadic eye movement. Activity of V5 was found at the intersection of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus during smooth pursuit eye movement. Our results suggest that functional magnetic resonance imaging is useful for detecting cortical activity during eye movement. (author)

Active filtering applied to radiographic images unfolded by the Richardson-Lucy algorithm

International Nuclear Information System (INIS)

Almeida, Gevaldo L. de; Silvani, Maria Ines; Lopes, Ricardo T.

2011-01-01

Degradation of images caused by systematic uncertainties can be reduced when one knows the features of the spoiling agent. Typical uncertainties of this kind arise in radiographic images due to the non - zero resolution of the detector used to acquire them, and from the non-punctual character of the source employed in the acquisition, or from the beam divergence when extended sources are used. Both features blur the image, which, instead of a single point exhibits a spot with a vanishing edge, reproducing hence the point spread function - PSF of the system. Once this spoiling function is known, an inverse problem approach, involving inversion of matrices, can then be used to retrieve the original image. As these matrices are generally ill-conditioned, due to statistical fluctuation and truncation errors, iterative procedures should be applied, such as the Richardson-Lucy algorithm. This algorithm has been applied in this work to unfold radiographic images acquired by transmission of thermal neutrons and gamma-rays. After this procedure, the resulting images undergo an active filtering which fairly improves their final quality at a negligible cost in terms of processing time. The filter ruling the process is based on the matrix of the correction factors for the last iteration of the deconvolution procedure. Synthetic images degraded with a known PSF, and undergone to the same treatment, have been used as benchmark to evaluate the soundness of the developed active filtering procedure. The deconvolution and filtering algorithms have been incorporated to a Fortran program, written to deal with real images, generate the synthetic ones and display both. (author)

Scoring inflammatory activity of the spine by magnetic resonance imaging in ankylosing spondylitis: a multireader experiment

DEFF Research Database (Denmark)

Lukas, Cédric; Braun, Jürgen; van der Heijde, Désirée

2007-01-01

= 10) and selected to cover a wide range of activity at baseline and change in activity, were presented electronically in a partial latin-square design to 9 experienced readers from different countries (Europe, Canada). Readers scored each set of MRI 3 times, using 3 different methods including...... the Ankylosing Spondylitis spine Magnetic Resonance Imaging-activity [ASspiMRI-a, grading activity (0-6) per vertebral unit in 23 units]; the Berlin modification of the ASspiMRI-a; and the Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system, which scores the 6 vertebral units considered......) assessed by Z-scores was good and comparable among methods. CONCLUSION: This experiment demonstrates the feasibility of multiple-reader MRI scoring exercises for method comparison, provides evidence for the feasibility, reliability, sensitivity to change, and discriminatory capacity of all 3 tested scoring...

Use of blood-pool imaging in evaluation of diffuse activity patterns in technetium-99m pyrophosphate myocardial scintigraphy.

Science.gov (United States)

Cowley, M J; Mantle, J A; Rogers, W J; Russell, R O; Rackley, C E; Logic, J R

1979-06-01

It has been suggested that diffuse Tc-99m pyrophosphate precordial activity may be due to persistent blood-pool activity in routine delayed views during myocardial imaging. To answer this question, we reviewed myocardial scintigrams recorded 60--90 min following the injection of 12--15 mCi of Tc-99m pyrophosphate for the presence of diffuse precordial activity, and compared these with early images of the blood pool in 265 patients. Diffuse activity in the delayed images was identified in 48 patients: in 20 with acute myocardial infarction and in 28 with no evidence of it. Comparison of these routine delayed images with early views of the blood pool revealed two types of patterns. In patients with acute infarction, 95% had delayed images that were distinguishable from blood pool either because the activity was smaller than the early blood pool, or by the presence of localized activity superimposed on diffuse activity identical to blood pool. In those without infarction, 93% had activity distribution in routine delayed views matching that in the early blood-pool images. The usefulness of the diffuse TcPPi precordial activity in myocardial infarction is improved when early blood-pool imaging is used to exclude persistence of blood-pool activity as its cause. Moreover, it does not require additional amounts of radioactivity nor complex computer processing, a feature that may be of value in the community hospital using the technique to "rule out" infarction 24--72 hr after onset of suggestive symptoms.

Body image dissatisfaction and its relationship with physical activity and nutritional status in university students

Directory of Open Access Journals (Sweden)

Elisa Pinheiro Ferrari

2012-10-01

Full Text Available The aim of the present study was to evaluate the association of body image dissatisfaction with physical activity level and nutritional status in freshmen from a public Brazilian university. A total of 832 university students (485 men with a mean age of 20.1 years (standard deviation = 4.6 participated in the study. Self-reported body weight and height were used for the calculation of body mass index. The students responded to the Body Shape Questionnaire and International Physical Activity Questionnaire. Data were analyzed using Fisher’s exact test, considering p < .05. The prevalence of body image dissatisfaction and physical inactivity was 10.1% and 14.5%, respectively. No significant association was observed between body image dissatisfaction and physical activity level. Body image dissatisfaction was associated with nutritional status in both genders (p < .05. University students with excess body weight should be encouraged to pursue a healthier lifestyle in order to promote an adequate nutritional status and also to improve their body image.

X-ray imaging characterization of active edge silicon pixel sensors

International Nuclear Information System (INIS)

Ponchut, C; Ruat, M; Kalliopuska, J

2014-01-01

The aim of this work was the experimental characterization of edge effects in active-edge silicon pixel sensors, in the frame of X-ray pixel detectors developments for synchrotron experiments. We produced a set of active edge pixel sensors with 300 to 500 μm thickness, edge widths ranging from 100 μm to 150 μm, and n or p pixel contact types. The sensors with 256 × 256 pixels and 55 × 55 μm 2 pixel pitch were then bump-bonded to Timepix readout chips for X-ray imaging measurements. The reduced edge widths makes the edge pixels more sensitive to the electrical field distribution at the sensor boundaries. We characterized this effect by mapping the spatial response of the sensor edges with a finely focused X-ray synchrotron beam. One of the samples showed a distortion-free response on all four edges, whereas others showed variable degrees of distortions extending at maximum to 300 micron from the sensor edge. An application of active edge pixel sensors to coherent diffraction imaging with synchrotron beams is described

Detection of cortical activities on eye movement using functional magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Masaki; Kawai, Kazushige; Kitahara, Kenji [Jikei Univ., Tokyo (Japan). School of Medicine; Soulie, D.; Cordoliani, Y.S.; Iba-Zizen, M.T.; Cabanis, E.A.

1997-11-01

Cortical activity during eye movement was examined with functional magnetic resonance imaging. Horizontal saccadic eye movements and smooth pursuit eye movements were elicited in normal subjects. Activity in the frontal eye field was found during both saccadic and smooth pursuit eye movements at the posterior margin of the middle frontal gyrus and in parts of the precentral sulcus and precentral gyrus bordering the middle frontal gyrus (Brodmann`s areas 8, 6, and 9). In addition, activity in the parietal eye field was found in the deep, upper margin of the angular gyrus and of the supramarginal gyrus (Brodmann`s areas 39 and 40) during saccadic eye movement. Activity of V5 was found at the intersection of the ascending limb of the inferior temporal sulcus and the lateral occipital sulcus during smooth pursuit eye movement. Our results suggest that functional magnetic resonance imaging is useful for detecting cortical activity during eye movement. (author)

Functional magnetic resonance imaging of higher brain activity

International Nuclear Information System (INIS)

Cui He; Wang Yunjiu; Chen Runsheng; Tang Xiaowei.

1996-01-01

Functional magnetic resonance images (fMRIs) exhibit small differences in the magnetic resonance signal intensity in positions corresponding to focal areas of brain activation. These signal are caused by variation in the oxygenation state of the venous vasculature. Using this non-invasive and dynamic method, it is possible to localize functional brain activation, in vivo, in normal individuals, with an accuracy of millimeters and a temporal resolution of seconds. Though a series of technical difficulties remain, fMRI is increasingly becoming a key method for visualizing the working brain, and uncovering the topographical organization of the human brain, and understanding the relationship between brain and the mind

Imaging large cohorts of single ion channels and their activity

Directory of Open Access Journals (Sweden)

Katia eHiersemenzel

2013-09-01

Full Text Available As calcium is the most important signaling molecule in neurons and secretory cells, amongst many other cell types, it follows that an understanding of calcium channels and their regulation of exocytosis is of vital importance. Calcium imaging using calcium dyes such as Fluo3, or FRET-based dyes that have been used widely has provided invaluable information, which combined with modeling has estimated the sub-types of channels responsible for triggering the exocytotic machinery as well as inferences about the relative distances away from vesicle fusion sites these molecules adopt. Importantly, new super-resolution microscopy techniques, combined with novel Ca2+ indicators and imaginative imaging approaches can now define directly the nanoscale locations of very large cohorts of single channel molecules in relation to single vesicles. With combinations of these techniques the activity of individual channels can be visualized and quantified using novel Ca2+ indicators. Fluorescently labeled specific channel toxins can also be used to localize endogenous assembled channel tetramers. Fluorescence lifetime imaging microscopy and other single-photon-resolution spectroscopic approaches offer the possibility to quantify protein-protein interactions between populations of channels and the SNARE protein machinery for the first time. Together with simultaneous electrophysiology, this battery of quantitative imaging techniques has the potential to provide unprecedented detail describing the locations, dynamic behaviours, interactions and conductance activities of many thousands of channel molecules and vesicles in living cells.

Non-traumatic thoracic emergencies: imaging and treatment of thoracic fluid collections (including pneumothorax)

International Nuclear Information System (INIS)

Ellis, J.R.C.; Gleeson, F.V.

2002-01-01

Cross-sectional imaging has revolutionised the radiological diagnosis of pleural collections. Not only can the precise location and volume of a pleural effusion be established, but also features specific for the aetiology of the effusion can be demonstrated. Increasingly, radiologists are called upon to perform image-guided biopsies, aspirations and small bore chest drain placement, all of which have been shown to be safe and efficacious. Pneumothoraces occurring due to acute trauma and in an intensive care setting can also benefit from radiological input, both in terms of diagnosis and image-guided treatment. (orig.)

Non-traumatic thoracic emergencies: imaging and treatment of thoracic fluid collections (including pneumothorax)

Energy Technology Data Exchange (ETDEWEB)

Ellis, J.R.C.; Gleeson, F.V. [Department of Radiology, The Churchill Hospital, Old Road, Headington, Oxford OX3 7LJ (United Kingdom)

2002-08-01

Cross-sectional imaging has revolutionised the radiological diagnosis of pleural collections. Not only can the precise location and volume of a pleural effusion be established, but also features specific for the aetiology of the effusion can be demonstrated. Increasingly, radiologists are called upon to perform image-guided biopsies, aspirations and small bore chest drain placement, all of which have been shown to be safe and efficacious. Pneumothoraces occurring due to acute trauma and in an intensive care setting can also benefit from radiological input, both in terms of diagnosis and image-guided treatment. (orig.)

Comparison of bi-exponential and mono-exponential models of diffusion-weighted imaging for detecting active sacroiliitis in ankylosing spondylitis.

Science.gov (United States)

Sun, Haitao; Liu, Kai; Liu, Hao; Ji, Zongfei; Yan, Yan; Jiang, Lindi; Zhou, Jianjun

2018-04-01

Background There has been a growing need for a sensitive and effective imaging method for the differentiation of the activity of ankylosing spondylitis (AS). Purpose To compare the performances of intravoxel incoherent motion (IVIM)-derived parameters and the apparent diffusion coefficient (ADC) for distinguishing AS-activity. Material and Methods One hundred patients with AS were divided into active (n = 51) and non-active groups (n = 49) and 21 healthy volunteers were included as control. The ADC, diffusion coefficient ( D), pseudodiffusion coefficient ( D*), and perfusion fraction ( f) were calculated for all groups. Kruskal-Wallis tests and receiver operator characteristic (ROC) curve analysis were performed for all parameters. Results There was good reproducibility of ADC /D and relatively poor reproducibility of D*/f. ADC, D, and f were significantly higher in the active group than in the non-active and control groups (all P  0.050). In the ROC analysis, ADC had the largest AUC for distinguishing between the active group and the non-active group (0.988) and between the active and control groups (0.990). Multivariate logistic regression analysis models showed no diagnostic improvement. Conclusion ADC provided better diagnostic performance than IVIM-derived parameters in differentiating AS activity. Therefore, a straightforward and effective mono-exponential model of diffusion-weighted imaging may be sufficient for differentiating AS activity in the clinic.

Use of blood-pool imaging in evaluation of diffuse activity patterns in technetium-99m pyrophosphate myocardial scintigraphy

International Nuclear Information System (INIS)

Cowley, M.J.; Mantle, J.A.; Rogers, W.J.; Russell, R.O. Jr.; Rackley, C.E.; Logic, J.R.

1979-01-01

It has been suggested that diffuse 99m Tc pyrophosphate precordial activity may be due to persistent blood-pool activity in routine delayed views during myocardial imaging. To answer this question, we reviewed myocardial scintigrams recorded 60 to 90 min following the injection of 12 to 15 mCi of 99m Tc pyrophosphate for the presence of diffuse precordial activity, and compared these with early images of the blood pool in 265 patients. Diffuse activity in the delayed images was identified in 48 patients: in 20 with acute myocardial infarction and in 28 with no evidence of it. Comparison of these routine delayed images with early views of the blood pool revealed two types of patterns. In patients with acute infarction, 95% had delayed images that were distinguishable from blood pool either because the activity was smaller than the early blood pool, or by the presence of localized activity superimposed on diffuse activity identical to blood pool. In those without infarction, 93% had activity distribution in routine delayed views matching that in the early blood-pool images. The usefulness of the diffuse TcPPi precordial activity in myocardial infarction is improved when early blood-pool imaging is used to exclude persistence of blood-pool activity as its cause. Moreover, it does not require additional amounts of radioactivity nor complex computer processing, a feature that may be of value in the community hospital using the technique to rule out infarction 24 to 72 hr after onset of suggestive symptoms

The Effect of Milk, Water and Lemon Juice on Various Subdiaphragmatic Activity-Related Artifacts in Myocardial Perfusion Imaging.

Science.gov (United States)

Malek, Hadi; Hedayati, Raheleh; Yaghoobi, Nahid; Bitarafan-Rajabi, Ahmad; Firoozabadi, Seyed Hassan; Rastgou, Feridoon

2015-11-01

Subdiaphragmatic activity can produce subdiaphragmatic-related artifacts, which can degrade the quality of myocardial perfusion imaging (MPI). We examined the impact of drinking milk, water, and lemon juice on different subdiaphragmatic-related artifacts by using (99m)Tc-sestamibi myocardial single-photon emission computed tomography (SPECT) in order to determine a feasible method for improving the image quality. A total of 179 patients (age 58 ± 9.6 years) were enrolled in this study. The patients were randomly divided into five groups. Ten minutes after injection of 740 MBq 99mTc-sestamibi in both pharmacologic stress and rest phases, the individuals in group 1 were given water and milk (125 mL of each); those in group 2 were given lemon juice (250 mL); group 3 was given milk (250 mL); and group 4 was given water (250 mL), whereas no intervention was performed in group 5. The study was double-blind for both subjects and data collectors. MPI was performed for all patients and image quality was controlled by 2 experienced nuclear physicians. Interfering activity was determined visually on reconstructed images and categorized as extracardiac normalization artifact, overlapping of activity, scattering of activity, and ramp filter artifact. There were significant differences in terms of interfering activity among the five groups; group 3 (milk) had significantly lower interfering activity than other groups had, as defined by overlapping of activity (on both stress and rest images), ramp filter artifact (stress images), and scatter artifact (rest images) (P < 0.05). Furthermore, there was a significant difference in the incidence of good-quality images, with no interfering activity in group 3 in the resting state compared with the other groups in the study (P < 0.05). Drinking 250 mL of milk in either the stress phase or the rest phase of imaging diminishes interfering subdiaphragmatic-related artifacts, particularly overlapping of activity in MPI SPECT, resulting in

Perceived Body Image, Eating Behavior, and Sedentary Activities and Body Mass Index Categories in Kuwaiti Female Adolescents

Directory of Open Access Journals (Sweden)

Lemia H. Shaban

2016-01-01

Full Text Available Background. The State of Kuwait has a growing obesity epidemic in both genders and all age groups; however, obesity rates in the young seem to be rising. Methods. We conducted a cross-sectional survey in 169 Kuwaiti female adolescents attending both private and public schools spanning the six governorates in the State of Kuwait in order to explore female adolescents’ self-image, body dissatisfaction, type of school (private versus public, TV viewing, and computer games and their relationship to body mass index. Results. Approximately half the students classified as obese perceived their body image to lie in the normal range. Females in the obese category were the most dissatisfied with their body image, followed by those in the overweight category. Eating behavior, level of physical activity, school type, television viewing, computer/video usage, and desired BMI were not significantly associated with level of obesity. Conclusion. This study was one of the few studies to assess adolescent females’ body image dissatisfaction in relation to obesity in the State of Kuwait. The results suggest that including body image dissatisfaction awareness into obesity prevention programs would be of value.

Noninvasive imaging of three-dimensional cardiac activation sequence during pacing and ventricular tachycardia.

Science.gov (United States)

Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; He, Bin

2011-08-01

Imaging cardiac excitation within ventricular myocardium is important in the treatment of cardiac arrhythmias and might help improve our understanding of arrhythmia mechanisms. This study sought to rigorously assess the imaging performance of a 3-dimensional (3D) cardiac electrical imaging (3DCEI) technique with the aid of 3D intracardiac mapping from up to 216 intramural sites during paced rhythm and norepinephrine (NE)-induced ventricular tachycardia (VT) in the rabbit heart. Body surface potentials and intramural bipolar electrical recordings were simultaneously measured in a closed-chest condition in 13 healthy rabbits. Single-site pacing and dual-site pacing were performed from ventricular walls and septum. VTs and premature ventricular complexes (PVCs) were induced by intravenous NE. Computed tomography images were obtained to construct geometry models. The noninvasively imaged activation sequence correlated well with invasively measured counterpart, with a correlation coefficient of 0.72 ± 0.04, and a relative error of 0.30 ± 0.02 averaged over 520 paced beats as well as 73 NE-induced PVCs and VT beats. All PVCs and VT beats initiated in the subendocardium by a nonreentrant mechanism. The averaged distance from the imaged site of initial activation to the pacing site or site of arrhythmias determined from intracardiac mapping was ∼5 mm. For dual-site pacing, the double origins were identified when they were located at contralateral sides of ventricles or at the lateral wall and the apex. 3DCEI can noninvasively delineate important features of focal or multifocal ventricular excitation. It offers the potential to aid in localizing the origins and imaging activation sequences of ventricular arrhythmias, and to provide noninvasive assessment of the underlying arrhythmia mechanisms. Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

GPU-based simulation of optical propagation through turbulence for active and passive imaging

Science.gov (United States)

Monnier, Goulven; Duval, François-Régis; Amram, Solène

2014-10-01

IMOTEP is a GPU-based (Graphical Processing Units) software relying on a fast parallel implementation of Fresnel diffraction through successive phase screens. Its applications include active imaging, laser telemetry and passive imaging through turbulence with anisoplanatic spatial and temporal fluctuations. Thanks to parallel implementation on GPU, speedups ranging from 40X to 70X are achieved. The present paper gives a brief overview of IMOTEP models, algorithms, implementation and user interface. It then focuses on major improvements recently brought to the anisoplanatic imaging simulation method. Previously, we took advantage of the computational power offered by the GPU to develop a simulation method based on large series of deterministic realisations of the PSF distorted by turbulence. The phase screen propagation algorithm, by reproducing higher moments of the incident wavefront distortion, provides realistic PSFs. However, we first used a coarse gaussian model to fit the numerical PSFs and characterise there spatial statistics through only 3 parameters (two-dimensional displacements of centroid and width). Meanwhile, this approach was unable to reproduce the effects related to the details of the PSF structure, especially the "speckles" leading to prominent high-frequency content in short-exposure images. To overcome this limitation, we recently implemented a new empirical model of the PSF, based on Principal Components Analysis (PCA), ought to catch most of the PSF complexity. The GPU implementation allows estimating and handling efficiently the numerous (up to several hundreds) principal components typically required under the strong turbulence regime. A first demanding computational step involves PCA, phase screen propagation and covariance estimates. In a second step, realistic instantaneous images, fully accounting for anisoplanatic effects, are quickly generated. Preliminary results are presented.

Prostate Cancer Imaging and Biomarkers Guiding Safe Selection of Active Surveillance

Directory of Open Access Journals (Sweden)

Zachary A. Glaser

2017-10-01

Full Text Available BackgroundActive surveillance (AS is a widely adopted strategy to monitor men with low-risk, localized prostate cancer (PCa. Current AS inclusion criteria may misclassify as many as one in four patients. The advent of multiparametric magnetic resonance imaging (mpMRI and novel PCa biomarkers may offer improved risk stratification. We performed a review of recently published literature to characterize emerging evidence in support of these novel modalities.MethodsAn English literature search was conducted on PubMed for available original investigations on localized PCa, AS, imaging, and biomarkers published within the past 3 years. Our Boolean criteria included the following terms: PCa, AS, imaging, biomarker, genetic, genomic, prospective, retrospective, and comparative. The bibliographies and diagnostic modalities of the identified studies were used to expand our search.ResultsOur review identified 222 original studies. Our expanded search yielded 244 studies. Among these, 70 met our inclusion criteria. Evidence suggests mpMRI offers improved detection of clinically significant PCa, and MRI-fusion technology enhances the sensitivity of surveillance biopsies. Multiple studies demonstrate the promise of commercially available screening assays for prediction of AS failure, and several novel biomarkers show promise in this setting.ConclusionIn the era of AS for men with low-risk PCa, improved strategies for proper stratification are needed. mpMRI has dramatically enhanced the detection of clinically significant PCa. The advent of novel biomarkers for prediction of aggressive disease and AS failure has shown some initial promise, but further validation is warranted.

Preliminary results of MR imaging of lymphoma: Distinguishing active tumor from benign residue

International Nuclear Information System (INIS)

Drace, J.; Baker, L.L.; Chang, P.; Castellino, R.A.

1987-01-01

Distinguishing tumor from benign posttreatment tissue based on both morphologic and tissue characteristics is critically important. Patients are studied before, during, and after treatment; at the time of recurrence; and on long-term follow-up. Multisection spin-echo sequences in orthogonal planes and a special single-section tissue characterization matrix of 16 different repetition time/echo time combinations are used. These basic images are used for cluster analysis (approximate fuzzy C means), T1-T2 synthetic images, linear combinations, and comparison with internal standards. Preliminary results in 35 patients imaged before treatment and 12 patients with follow-up examinations consistently show lymphoma masses to have complex architecture with high T2-weighted signal and moderate T1-weighted signal, distinct from posttreatment fibrosis. Uncommon components of active tumor with low T2-weighted signal appear distinct from fibrosis on T1-weighted images. Preliminary cluster analysis results show distinct clustering of active lymphoma versus fibrosis and biopsy-proved cystic degeneration

Body image satisfaction and the view of active old women about the influence of physical exercise in their self-image

Directory of Open Access Journals (Sweden)

Josinéia Gresele Coradini

2013-06-01

Full Text Available The aim of this paper was to analyze the body image satisfaction with 24 active elderly women, and to understand the view of these people about the connection between physical exercise and their body image. All of them answered to the scale proposed by Stunkard, Sorenson and Schlusinger, 1983 and to a semi-structured interview. 87.50% of the women were unsatisfied about the body image. From the reading and analysis of the speeches, it was formed two major categories and four subcategories. Thus, most of the elderly women are unsatisfied about their body image, but the proportionate benefits by the exercises are recognized.

Lesions inflammatory activity quantification in multiple sclerosis using ["1"1C]-(R)-PK11195 PET brain images

International Nuclear Information System (INIS)

Schuck, Phelipi N.; Narciso, Lucas D.L.; Dartora, Caroline M.; Silva, Ana M. Marques da

2016-01-01

The criteria for multiple sclerosis (MS) diagnosis include the presence of lesions in brain regions called black holes (BH), characterized by low signal on magnetic resonance imaging T1-weighted. Studies suggest that lesions in MS, if there is an inflammatory process, can be detected in PET imaging with ["1"1C]- (R)-PK11195. The aim of this study is to investigate the uptake of ["1"1C]-(R)-PK11195 in BH in PET images, searching for inflammation activity in lesions and neighborhoods. Semiquantitative methods of SUV and uptake normalization were applied to PET images, in different time intervals, acquired from 8 MS patients and 5 healthy controls. Higher uptake was identified in BH and its edges, when compared with health controls white matter, when the SUV method is applied (p < 0,01, 40 to 60 min). When uptake normalization method is applied, smaller uptake in black holes and its your edges is observed, when compared with white matter apparently healthy (p < 0,01, 0 to 60 min). (author)

Molecular Targets for PET Imaging of Activated Microglia: The Current Situation and Future Expectations.

Science.gov (United States)

Tronel, Claire; Largeau, Bérenger; Santiago Ribeiro, Maria Joao; Guilloteau, Denis; Dupont, Anne-Claire; Arlicot, Nicolas

2017-04-11

Microglia, as cellular mediators of neuroinflammation, are implicated in the pathogenesis of a wide range of neurodegenerative diseases. Positron emission tomography (PET) imaging of microglia has matured over the last 20 years, through the development of radiopharmaceuticals targeting several molecular biomarkers of microglial activation and, among these, mainly the translocator protein-18 kDa (TSPO). Nevertheless, current limitations of TSPO as a PET microglial biomarker exist, such as low brain density, even in a neurodegenerative setting, expression by other cells than the microglia (astrocytes, peripheral macrophages in the case of blood brain barrier breakdown), genetic polymorphism, inducing a variation for most of TSPO PET radiopharmaceuticals' binding affinity, or similar expression in activated microglia regardless of its polarization (pro- or anti-inflammatory state), and these limitations narrow its potential interest. We overview alternative molecular targets, for which dedicated radiopharmaceuticals have been proposed, including receptors (purinergic receptors P2X7, cannabinoid receptors, α7 and α4β2 nicotinic acetylcholine receptors, adenosine 2A receptor, folate receptor β) and enzymes (cyclooxygenase, nitric oxide synthase, matrix metalloproteinase, β-glucuronidase, and enzymes of the kynurenine pathway), with a particular focus on their respective contribution for the understanding of microglial involvement in neurodegenerative diseases. We discuss opportunities for these potential molecular targets for PET imaging regarding their selectivity for microglia expression and polarization, in relation to the mechanisms by which microglia actively participate in both toxic and neuroprotective actions in brain diseases, and then take into account current clinicians' expectations.

MR imaging in adults with Gaucher disease type I: evulation of marrow involvement and disease activity

Energy Technology Data Exchange (ETDEWEB)

Hermann, G. (Dept. of Radiology, Mount Sinai Medical Center, City Univ. of New York, NY (United States)); Shaprio, R.S. (Dept. of Radiology, Mount Sinai Medical Center, City Univ. of New York, NY (United States)); Abdelwahab, I.F. (Dept. of Radiology, Mount Sinai Medical Center, City Univ. of New York, NY (United States)); Grabowski, G. (Dept. of Pediatrics, Mount Sinai Medical Center, City Univ. of New York, NY (United States))

1993-05-01

An investigation was conducted to determine the usefulness of magnetic resonance imaging (MRI) in the evaluation of bone marrow involvement in patients with Gaucher disease type I. T1- and T2-weighted images were obtained of the lower extremities of 29 adult patients. Patients were classified into one of three groups based on marrow signal patterns on T1- and T2-weighted images as well as change in signal intensity from T1- to T2-weighted images. An increase in signal intensity from T1- to T2-weighted images was the criterion for an 'active process' within the bone marrow. Classification of the 29 patients produced the following results: Group A: Normal, 4 patients; group B: Marrow infiltration, 16 patients; group C: Marrow infiltration plus active marrow process, 9 patients. Correlation with clinical findings revealed that all nine patients with evidence of an active marrow process on MRI (group C) had acute bone pain. Conversely, only one of the remaining 20 patients (groups A and B) had bone pain. There was no correlation between disease activity and findings on conventional radiographs. We conclude the MRI provides an excellent noninvasive assessment of the extent and activity of marrow involvement in type I Gaucher disease. (orig.)

MR imaging in adults with Gaucher disease type I: evulation of marrow involvement and disease activity

International Nuclear Information System (INIS)

Hermann, G.; Shaprio, R.S.; Abdelwahab, I.F.; Grabowski, G.

1993-01-01

An investigation was conducted to determine the usefulness of magnetic resonance imaging (MRI) in the evaluation of bone marrow involvement in patients with Gaucher disease type I. T1- and T2-weighted images were obtained of the lower extremities of 29 adult patients. Patients were classified into one of three groups based on marrow signal patterns on T1- and T2-weighted images as well as change in signal intensity from T1- to T2-weighted images. An increase in signal intensity from T1- to T2-weighted images was the criterion for an 'active process' within the bone marrow. Classification of the 29 patients produced the following results: Group A: Normal, 4 patients; group B: Marrow infiltration, 16 patients; group C: Marrow infiltration plus active marrow process, 9 patients. Correlation with clinical findings revealed that all nine patients with evidence of an active marrow process on MRI (group C) had acute bone pain. Conversely, only one of the remaining 20 patients (groups A and B) had bone pain. There was no correlation between disease activity and findings on conventional radiographs. We conclude the MRI provides an excellent noninvasive assessment of the extent and activity of marrow involvement in type I Gaucher disease. (orig.)

Molecular Imaging of the ATM Kinase Activity

Energy Technology Data Exchange (ETDEWEB)

Williams, Terence M. [Department of Radiation Oncology, Ohio State University, Columbus, Ohio (United States); Nyati, Shyam [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Center for Molecular Imaging, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Ross, Brian D. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Rehemtulla, Alnawaz, E-mail: alnawaz@umich.edu [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Center for Molecular Imaging, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)

2013-08-01

Purpose: Ataxia telangiectasia mutated (ATM) is a serine/threonine kinase critical to the cellular DNA-damage response, including from DNA double-strand breaks. ATM activation results in the initiation of a complex cascade of events including DNA damage repair, cell cycle checkpoint control, and survival. We sought to create a bioluminescent reporter that dynamically and noninvasively measures ATM kinase activity in living cells and subjects. Methods and Materials: Using the split luciferase technology, we constructed a hybrid cDNA, ATM-reporter (ATMR), coding for a protein that quantitatively reports on changes in ATM kinase activity through changes in bioluminescence. Results: Treatment of ATMR-expressing cells with ATM inhibitors resulted in a dose-dependent increase in bioluminescence activity. In contrast, induction of ATM kinase activity upon irradiation resulted in a decrease in reporter activity that correlated with ATM and Chk2 activation by immunoblotting in a time-dependent fashion. Nuclear targeting improved ATMR sensitivity to both ATM inhibitors and radiation, whereas a mutant ATMR (lacking the target phosphorylation site) displayed a muted response. Treatment with ATM inhibitors and small interfering (si)RNA-targeted knockdown of ATM confirm the specificity of the reporter. Using reporter expressing xenografted tumors demonstrated the ability of ATMR to report in ATM activity in mouse models that correlated in a time-dependent fashion with changes in Chk2 activity. Conclusions: We describe the development and validation of a novel, specific, noninvasive bioluminescent reporter that enables monitoring of ATM activity in real time, in vitro and in vivo. Potential applications of this reporter include the identification and development of novel ATM inhibitors or ATM-interacting partners through high-throughput screens and in vivo pharmacokinetic/pharmacodynamic studies of ATM inhibitors in preclinical models.

FIRST IMAGES FROM THE FOCUSING OPTICS X-RAY SOLAR IMAGER

Energy Technology Data Exchange (ETDEWEB)

Krucker, Säm; Glesener, Lindsay; Turin, Paul; McBride, Stephen; Glaser, David; Fermin, Jose; Lin, Robert [Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA (United States); Christe, Steven [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Ishikawa, Shin-nosuke [National Astronomical Observatory, Mitaka (Japan); Ramsey, Brian; Gubarev, Mikhail; Kilaru, Kiranmayee [NASA Marshall Space Flight Center, Huntsville, AL (United States); Takahashi, Tadayuki; Watanabe, Shin; Saito, Shinya [Institute of Space and Astronautical Science (ISAS)/JAXA, Sagamihara (Japan); Tajima, Hiroyasu [Solar-Terrestial Environment Laboratory, Nagoya University, Nagoya (Japan); Tanaka, Takaaki [Department of Physics, Kyoto University, Kyoto (Japan); White, Stephen [Air Force Research Laboratory, Albuquerque, NM (United States)

2014-10-01

The Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket payload flew for the first time on 2012 November 2, producing the first focused images of the Sun above 5 keV. To enable hard X-ray (HXR) imaging spectroscopy via direct focusing, FOXSI makes use of grazing-incidence replicated optics combined with fine-pitch solid-state detectors. On its first flight, FOXSI observed several targets that included active regions, the quiet Sun, and a GOES-class B2.7 microflare. This Letter provides an introduction to the FOXSI instrument and presents its first solar image. These data demonstrate the superiority in sensitivity and dynamic range that is achievable with a direct HXR imager with respect to previous, indirect imaging methods, and illustrate the technological readiness for a spaceborne mission to observe HXRs from solar flares via direct focusing optics.

Empirical validation of statistical parametric mapping for group imaging of fast neural activity using electrical impedance tomography.

Science.gov (United States)

Packham, B; Barnes, G; Dos Santos, G Sato; Aristovich, K; Gilad, O; Ghosh, A; Oh, T; Holder, D

2016-06-01

Electrical impedance tomography (EIT) allows for the reconstruction of internal conductivity from surface measurements. A change in conductivity occurs as ion channels open during neural activity, making EIT a potential tool for functional brain imaging. EIT images can have  >10 000 voxels, which means statistical analysis of such images presents a substantial multiple testing problem. One way to optimally correct for these issues and still maintain the flexibility of complicated experimental designs is to use random field theory. This parametric method estimates the distribution of peaks one would expect by chance in a smooth random field of a given size. Random field theory has been used in several other neuroimaging techniques but never validated for EIT images of fast neural activity, such validation can be achieved using non-parametric techniques. Both parametric and non-parametric techniques were used to analyze a set of 22 images collected from 8 rats. Significant group activations were detected using both techniques (corrected p  <  0.05). Both parametric and non-parametric analyses yielded similar results, although the latter was less conservative. These results demonstrate the first statistical analysis of such an image set and indicate that such an analysis is an approach for EIT images of neural activity.

Photoacoustic imaging to detect rat brain activation after cocaine hydrochloride injection

Science.gov (United States)

Jo, Janggun; Yang, Xinmai

2011-03-01

Photoacoustic imaging (PAI) was employed to detect small animal brain activation after the administration of cocaine hydrochloride. Sprague Dawley rats were injected with different concentrations (2.5, 3.0, and 5.0 mg per kg body) of cocaine hydrochloride in saline solution through tail veins. The brain functional response to the injection was monitored by photoacoustic tomography (PAT) system with horizontal scanning of cerebral cortex of rat brain. Photoacoustic microscopy (PAM) was also used for coronal view images. The modified PAT system used multiple ultrasonic detectors to reduce the scanning time and maintain a good signal-to-noise ratio (SNR). The measured photoacoustic signal changes confirmed that cocaine hydrochloride injection excited high blood volume in brain. This result shows PAI can be used to monitor drug abuse-induced brain activation.

The Stellar Imager (SI) Project: Resolving Stellar Surfaces, Interiors, and Magnetic Activity

Science.gov (United States)

Carpenter, Kenneth G.; Schrijver, K.; Karovska, M.

2007-01-01

The Stellar Imager (SI) is a UV/Optical. Space-Based Interferometer designed to enable 0.1 milli-arcsec (mas) spectral imaging of stellar surfaces and, via asteroseismology, stellar interiors and of the Universe in general. The ultra-sharp images of SI will revolutionize our view of many dynamic astrophysical processes by transforming point sources into extended sources, and snapshots into evolving views. The science of SI focuses on the role of magnetism in the Universe, particularly on magnetic activity on the surfaces of stars like the Sun. Its prime goal is to enable long-term forecasting of solar activity and the space weather that it drives. SI will also revolutionize our understanding of the formation of planetary systems, of the habitability and climatology of distant planets, and of many magneto-hydrodynamically controlled processes in the Universe. In this paper we discuss the science goals, technology needs, and baseline design of the SI mission.

Time Spent by Breast Imaging Radiologists to Perform Value-Added Activities at an Academic Cancer Center.

Science.gov (United States)

Collado-Mesa, Fernando; Klevos, Geetika; Arheart, Kristopher; Banks, James; Yepes, Monica; Net, Jose

2017-04-01

Health care reform in the United States has generated a paradigm shift in the practice of radiology aimed at increasing the degree of patient-centered care. We conducted a study to quantify the amount of time breast imaging radiologists spend on value-added activities at an academic comprehensive cancer center located in Miami, Florida, and accredited by the American College of Radiology as a Breast Imaging Center of Excellence. A prospective, observational study was conducted during a period of 20 consecutive workdays. Three participating breast imaging radiologists maintained a real-time log of each activity performed. A generalized linear model was used to perform a 1-way analysis of variance. An alpha level of .05 was used to determine statistical significance. The average daily time dedicated to these activities was 92.1 minutes (range, 56.4-132.2). The amount of time significantly differed among breast imaging radiologists and correlated with their assigned daily role (P value-added activities to help improve patients' experience across the continuity of their care. We propose that similar studies be conducted at other institutions to better assess the magnitude of this finding across different breast imaging care settings.

Multimodal Imaging of Human Brain Activity: Rational, Biophysical Aspects and Modes of Integration

Science.gov (United States)

Blinowska, Katarzyna; Müller-Putz, Gernot; Kaiser, Vera; Astolfi, Laura; Vanderperren, Katrien; Van Huffel, Sabine; Lemieux, Louis

2009-01-01

Until relatively recently the vast majority of imaging and electrophysiological studies of human brain activity have relied on single-modality measurements usually correlated with readily observable or experimentally modified behavioural or brain state patterns. Multi-modal imaging is the concept of bringing together observations or measurements from different instruments. We discuss the aims of multi-modal imaging and the ways in which it can be accomplished using representative applications. Given the importance of haemodynamic and electrophysiological signals in current multi-modal imaging applications, we also review some of the basic physiology relevant to understanding their relationship. PMID:19547657

Registering Active and Passive IMAGE RPI Datasets with the Virtual Wave Observatory

Science.gov (United States)

Galkin, I. A.; Fung, S.; King, T. A.; Reinisch, B. W.

2008-12-01

Development of the Virtual Wave Observatory (VWO) for acquired active/passive plasma wave and radiation datasets will be a significant step forward for the Heliophysics community in its efforts to make wave-specific science data searchable, understandable, and usable. The first phase of the VWO project commenced in September 2008 with the goal of converting existing custom database storing wave data acquired by the Radio Plasma Imager (RPI) on the NASA IMAGE satellite into the VxO realm and, specifically, the SPASE Data Model. The RPI dataset comprises 1.2 million active and 0.8 million passive stepped-frequency measurements whose exploration incurs substantial expense of data search and expert interpretation. Our attention is drawn to the ability of the VWO not only to organize numeric and display data records in the SPASE-compatible manner, but most importantly, provide the essential means to capture the wave research community knowledge in accompanying metadata so as to let users understand the VWO data collections and search them by phenomena and context conditions. To that end, we pursue to extend the SPASE model to include wave-relevant terms and to develop a VWO annotation service to provide searchable data interpretations to the scientists who may not be a wave expert. The SPASE Data Model provides several means to describe data sets in a unified manner, forging them together in a three large categories, (1) numeric data, (2) display data, and (3) catalogs. Whereas numeric data resources simply point to the instrument data, the other two categories refer to the presentation of derived and interpreted information. We consider images of the RPI data as derived products that required investment in time and effort to create, especially if their author provided interpretation of visible signatures and optimized the visualization settings to highlight the signatures. When such interpretations are available, they can be used to further group RPI data in categories

Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis

Energy Technology Data Exchange (ETDEWEB)

Sowa, Piotr [Oslo University Hospital, Department of Radiology and Nuclear Medicine, Oslo (Norway); University of Oslo, Institute of Clinical Medicine, Faculty of Medicine, Oslo (Norway); Owren Nygaard, Gro [Oslo University Hospital, Department of Neurology, Oslo (Norway); Bjoernerud, Atle [Intervention Center, Oslo University Hospital, Oslo (Norway); University of Oslo, Department of Physics, Oslo (Norway); Gulowsen Celius, Elisabeth [Oslo University Hospital, Department of Neurology, Oslo (Norway); University of Oslo, Institute of Health and Society, Faculty of Medicine, Oslo (Norway); Flinstad Harbo, Hanne [University of Oslo, Institute of Clinical Medicine, Faculty of Medicine, Oslo (Norway); Oslo University Hospital, Department of Neurology, Oslo (Norway); Kristiansen Beyer, Mona [Oslo University Hospital, Department of Radiology and Nuclear Medicine, Oslo (Norway); Oslo and Akershus University College of Applied Sciences, Department of Life Sciences and Health, Oslo (Norway)

2017-07-15

The utility of perfusion-weighted imaging in multiple sclerosis (MS) is not well investigated. The purpose of this study was to compare baseline normalized perfusion measures in subgroups of newly diagnosed MS patients. We wanted to test the hypothesis that this method can differentiate between groups defined according to disease severity and disease activity at 1 year follow-up. Baseline magnetic resonance imaging (MRI) including a dynamic susceptibility contrast perfusion sequence was performed on a 1.5-T scanner in 66 patients newly diagnosed with relapsing-remitting MS. From the baseline MRI, cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were generated. Normalized (n) perfusion values were calculated by dividing each perfusion parameter obtained in white matter lesions by the same parameter obtained in normal-appearing white matter. Neurological examination was performed at baseline and at follow-up approximately 1 year later to establish the multiple sclerosis severity score (MSSS) and evidence of disease activity (EDA). Baseline normalized mean transit time (nMTT) was lower in patients with MSSS >3.79 (p = 0.016), in patients with EDA (p = 0.041), and in patients with both MSSS >3.79 and EDA (p = 0.032) at 1-year follow-up. Baseline normalized cerebral blood flow and normalized cerebral blood volume did not differ between these groups. Lower baseline nMTT was associated with higher disease severity and with presence of disease activity 1 year later in newly diagnosed MS patients. Further longitudinal studies are needed to confirm whether baseline-normalized perfusion measures can differentiate between disease severity and disease activity subgroups over time. (orig.)

Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis

International Nuclear Information System (INIS)

Sowa, Piotr; Owren Nygaard, Gro; Bjoernerud, Atle; Gulowsen Celius, Elisabeth; Flinstad Harbo, Hanne; Kristiansen Beyer, Mona

2017-01-01

The utility of perfusion-weighted imaging in multiple sclerosis (MS) is not well investigated. The purpose of this study was to compare baseline normalized perfusion measures in subgroups of newly diagnosed MS patients. We wanted to test the hypothesis that this method can differentiate between groups defined according to disease severity and disease activity at 1 year follow-up. Baseline magnetic resonance imaging (MRI) including a dynamic susceptibility contrast perfusion sequence was performed on a 1.5-T scanner in 66 patients newly diagnosed with relapsing-remitting MS. From the baseline MRI, cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were generated. Normalized (n) perfusion values were calculated by dividing each perfusion parameter obtained in white matter lesions by the same parameter obtained in normal-appearing white matter. Neurological examination was performed at baseline and at follow-up approximately 1 year later to establish the multiple sclerosis severity score (MSSS) and evidence of disease activity (EDA). Baseline normalized mean transit time (nMTT) was lower in patients with MSSS >3.79 (p = 0.016), in patients with EDA (p = 0.041), and in patients with both MSSS >3.79 and EDA (p = 0.032) at 1-year follow-up. Baseline normalized cerebral blood flow and normalized cerebral blood volume did not differ between these groups. Lower baseline nMTT was associated with higher disease severity and with presence of disease activity 1 year later in newly diagnosed MS patients. Further longitudinal studies are needed to confirm whether baseline-normalized perfusion measures can differentiate between disease severity and disease activity subgroups over time. (orig.)

A medical imaging analysis system for trigger finger using an adaptive texture-based active shape model (ATASM in ultrasound images.

Directory of Open Access Journals (Sweden)

Bo-I Chuang

Full Text Available Trigger finger has become a prevalent disease that greatly affects occupational activity and daily life. Ultrasound imaging is commonly used for the clinical diagnosis of trigger finger severity. Due to image property variations, traditional methods cannot effectively segment the finger joint's tendon structure. In this study, an adaptive texture-based active shape model method is used for segmenting the tendon and synovial sheath. Adapted weights are applied in the segmentation process to adjust the contribution of energy terms depending on image characteristics at different positions. The pathology is then determined according to the wavelet and co-occurrence texture features of the segmented tendon area. In the experiments, the segmentation results have fewer errors, with respect to the ground truth, than contours drawn by regular users. The mean values of the absolute segmentation difference of the tendon and synovial sheath are 3.14 and 4.54 pixels, respectively. The average accuracy of pathological determination is 87.14%. The segmentation results are all acceptable in data of both clear and fuzzy boundary cases in 74 images. And the symptom classifications of 42 cases are also a good reference for diagnosis according to the expert clinicians' opinions.

Physical activity practice, body image and visual impairment: a comparison between Brazilian and Italian children and adolescents.

Science.gov (United States)

Greguol, Márcia; Gobbi, Erica; Carraro, Attilio

2014-01-01

The aim of this study was to analyze the physical activity and body image of children and adolescents with visual impairment (VI) in Brazil and Italy. For this, 41 children and adolescents with VI (19 Brazilian and 22 Italian) aged 10.22 ± 2.19 years old (18 girls and 23 boys) answered the Physical Activity Questionnaire for Children (PAQ-C), the Offer Self-Image Questionnaire (OSIQ), and an instrument with information about the disability, body weight and height. We analyzed the relationship between data from PAQ-C and OSIQ, as well as the gender, level of disability (blindness or low vision) and country using independent Mann-Whitney test. Body mass index (BMI) values were higher for Brazilian youths, with more than half of them classified as overweight and obese. Italian youths exhibited values of body image that were more positive and only 27% presented overweight or obesity. Blind children and adolescents were less active than those with low vision, but no differences were found between countries or genders. In Brazil, we detected significant correlations (p>0.05) between physical activity, body image and BMI, which more active youths presenting lower values of BMI and a better perception of body image. Physical activity seems to have a positive influence on body image and BMI for children and adolescents with VI, thus it should be encouraged especially for those with higher disability degrees. Copyright © 2013 Elsevier Ltd. All rights reserved.

Use of the one‐legged hyperextension test and magnetic resonance imaging in the diagnosis of active spondylolysis

Science.gov (United States)

Masci, L; Pike, J; Malara, F; Phillips, B; Bennell, K; Brukner, P

2006-01-01

Background Active spondylolysis is an acquired lesion in the pars interarticularis and is a common cause of low back pain in the young athlete. Objectives To evaluate whether the one‐legged hyperextension test can assist in the clinical detection of active spondylolysis and to determine whether magnetic resonance imaging (MRI) is equivalent to the clinical gold standard of bone scintigraphy and computed tomography in the radiological diagnosis of this condition. Methods A prospective cohort design was used. Young active subjects with low back pain were recruited. Outcome measures included clinical assessment (one‐legged hyperextension test) and radiological investigations including bone scintigraphy (with single photon emission computed tomography (SPECT)) and MRI. Computed tomography was performed if bone scintigraphy was positive. Results Seventy one subjects were recruited. Fifty pars interarticulares in 39 subjects (55%) had evidence of active spondylolysis as defined by bone scintigraphy (with SPECT). Of these, 19 pars interarticulares in 14 subjects showed a fracture on computed tomography. The one‐legged hyperextension test was neither sensitive nor specific for the detection of active spondylolysis. MRI revealed bone stress in 40 of the 50 pars interarticulares in which it was detected by bone scintigraphy (with SPECT), indicating reduced sensitivity in detecting bone stress compared with bone scintigraphy (p  =  0.001). Conversely, MRI revealed 18 of the 19 pars interarticularis fractures detected by computed tomography, indicating concordance between imaging modalities (p  =  0.345). There was a significant difference between MRI and the combination of bone scintigraphy (with SPECT)/computed tomography in the radiological visualisation of active spondylolysis (p  =  0.002). Conclusions These results suggest that there is a high rate of active spondylolysis in active athletes with low back pain. The one‐legged hyperextension test is not

Segmentation of solid subregion of high grade gliomas in MRI images based on active contour model (ACM)

Science.gov (United States)

Seow, P.; Win, M. T.; Wong, J. H. D.; Abdullah, N. A.; Ramli, N.

2016-03-01

Gliomas are tumours arising from the interstitial tissue of the brain which are heterogeneous, infiltrative and possess ill-defined borders. Tumour subregions (e.g. solid enhancing part, edema and necrosis) are often used for tumour characterisation. Tumour demarcation into substructures facilitates glioma staging and provides essential information. Manual segmentation had several drawbacks that include laborious, time consuming, subjected to intra and inter-rater variability and hindered by diversity in the appearance of tumour tissues. In this work, active contour model (ACM) was used to segment the solid enhancing subregion of the tumour. 2D brain image acquisition data using 3T MRI fast spoiled gradient echo sequence in post gadolinium of four histologically proven high-grade glioma patients were obtained. Preprocessing of the images which includes subtraction and skull stripping were performed and then followed by ACM segmentation. The results of the automatic segmentation method were compared against the manual delineation of the tumour by a trainee radiologist. Both results were further validated by an experienced neuroradiologist and a brief quantitative evaluations (pixel area and difference ratio) were performed. Preliminary results of the clinical data showed the potential of ACM model in the application of fast and large scale tumour segmentation in medical imaging.

Segmentation of solid subregion of high grade gliomas in MRI images based on active contour model (ACM)

International Nuclear Information System (INIS)

Seow, P; Win, M T; Wong, J H D; Ramli, N; Abdullah, N A

2016-01-01

Gliomas are tumours arising from the interstitial tissue of the brain which are heterogeneous, infiltrative and possess ill-defined borders. Tumour subregions (e.g. solid enhancing part, edema and necrosis) are often used for tumour characterisation. Tumour demarcation into substructures facilitates glioma staging and provides essential information. Manual segmentation had several drawbacks that include laborious, time consuming, subjected to intra and inter-rater variability and hindered by diversity in the appearance of tumour tissues. In this work, active contour model (ACM) was used to segment the solid enhancing subregion of the tumour. 2D brain image acquisition data using 3T MRI fast spoiled gradient echo sequence in post gadolinium of four histologically proven high-grade glioma patients were obtained. Preprocessing of the images which includes subtraction and skull stripping were performed and then followed by ACM segmentation. The results of the automatic segmentation method were compared against the manual delineation of the tumour by a trainee radiologist. Both results were further validated by an experienced neuroradiologist and a brief quantitative evaluations (pixel area and difference ratio) were performed. Preliminary results of the clinical data showed the potential of ACM model in the application of fast and large scale tumour segmentation in medical imaging. (paper)

Imaging Primary Mouse Sarcomas After Radiation Therapy Using Cathepsin-Activatable Fluorescent Imaging Agents

Energy Technology Data Exchange (ETDEWEB)

Cuneo, Kyle C. [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Mito, Jeffrey K.; Javid, Melodi P. [Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States); Ferrer, Jorge M. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Kim, Yongbaek [Department of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul (Korea, Republic of); Lee, W. David [The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Bawendi, Moungi G. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Brigman, Brian E. [Department of Orthopedic Surgery, Duke University School of Medicine, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States)

2013-05-01

Purpose: Cathepsin-activated fluorescent probes can detect tumors in mice and in canine patients. We previously showed that these probes can detect microscopic residual sarcoma in the tumor bed of mice during gross total resection. Many patients with soft tissue sarcoma (STS) and other tumors undergo radiation therapy (RT) before surgery. This study assesses the effect of RT on the ability of cathepsin-activated probes to differentiate between normal and cancerous tissue. Methods and Materials: A genetically engineered mouse model of STS was used to generate primary hind limb sarcomas that were treated with hypofractionated RT. Mice were injected intravenously with cathepsin-activated fluorescent probes, and various tissues, including the tumor, were imaged using a hand-held imaging device. Resected tumor and normal muscle samples were harvested to assess cathepsin expression by Western blot. Uptake of activated probe was analyzed by flow cytometry and confocal microscopy. Parallel in vitro studies using mouse sarcoma cells were performed. Results: RT of primary STS in mice and mouse sarcoma cell lines caused no change in probe activation or cathepsin protease expression. Increasing radiation dose resulted in an upward trend in probe activation. Flow cytometry and immunofluorescence showed that a substantial proportion of probe-labeled cells were CD11b-positive tumor-associated immune cells. Conclusions: In this primary murine model of STS, RT did not affect the ability of cathepsin-activated probes to differentiate between tumor and normal muscle. Cathepsin-activated probes labeled tumor cells and tumor-associated macrophages. Our results suggest that it would be feasible to include patients who have received preoperative RT in clinical studies evaluating cathepsin-activated imaging probes.

Evaluating imaging devices

International Nuclear Information System (INIS)

Rollo, F.D.

1977-01-01

The performance of any imaging device depends on two principal factors inherent to the device, namely, plane sensitivity and spatial resolution. These factors may be defined as follows: plane sensitivity is the counts per second recorded by the imaging device for each disintegration per second per square centimeter occurring within a plane sheet of radioactivity. Spatial resolution may be defined as the fidelity with which the imaging device reproduces the activity distribution of an object in the image plane. In all imaging devices, a trade-off exists between these two parameters; that is, as sensitivity improves, spatial resolution is degraded, and vice versa. Therefore, to fully evaluate an imaging system a technique should be selected that measures both parameters and reflects the trade-off between the two. In addition, the method should approximate the clinical problem, namely, the detection of a focal lesion within an activity distribution. Several methods have been described to evaluate nuclear imaging devices. The more common techniques include the use of organ phantoms, bar phantoms, line-spread functions, modulation transfer functions, contrast efficiency functions, and performance index functions. Each of these techniques is briefly described in this chapter, and their advantages and disadvantages are discussed. In addition, a phantom that can be used to simply and completely measure overall imaging system performance is described

Gallbladder Boundary Segmentation from Ultrasound Images Using Active Contour Model

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Ciecholewski, Marcin

Extracting the shape of the gallbladder from an ultrasonography (US) image allows superfluous information which is immaterial in the diagnostic process to be eliminated. In this project an active contour model was used to extract the shape of the gallbladder, both for cases free of lesions, and for those showing specific disease units, namely: lithiasis, polyps and changes in the shape of the organ, such as folds or turns of the gallbladder. The approximate shape of the gallbladder was found by applying the motion equation model. The tests conducted have shown that for the 220 US images of the gallbladder, the area error rate (AER) amounted to 18.15%.

Benign familial fleck retina: multimodal imaging including optical coherence tomography angiography.

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Garcia, Jose Mauricio Botto de Barros; Isaac, David Leonardo Cruvinel; Sardeiro, Tainara; Aquino, Érika; Avila, Marcos

2017-01-01

This report presents multimodal imaging of a 27-year-old woman diagnosed with benign familial fleck retina (OMIM 228980), an uncommon disorder. Fundus photographs revealed retinal flecks that affected her post-equatorial retina but spared the macular area. Fundus autofluorescence and infrared imaging demonstrated a symmetrical pattern of yellow-white fleck lesions that affected both eyes. Her full-field electroretinogram and electrooculogram were normal. An optical coherence tomography B-scan was performed for both eyes, revealing increased thickness of the retinal pigmented epithelium leading to multiple small pigmented epithelium detachments. The outer retina remained intact in both eyes. Spectral-domain optical coherence tomography angiography with split-spectrum amplitude decorrelation algorithm and 3 × 3 mm structural en face optical coherence tomography did not show macular lesions. Benign familial fleck retina belongs to a heterogenous group of so-called flecked retina syndromes, and should be considered in patients with yellowish-white retinal lesions without involvement of the macula.

Benign familial fleck retina: multimodal imaging including optical coherence tomography angiography

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Jose Mauricio Botto de Barros Garcia

Full Text Available ABSTRACT This report presents multimodal imaging of a 27-year-old woman diagnosed with benign familial fleck retina (OMIM 228980, an uncommon disorder. Fundus photographs revealed retinal flecks that affected her post-equatorial retina but spared the macular area. Fundus autofluorescence and infrared imaging demonstrated a symmetrical pattern of yellow-white fleck lesions that affected both eyes. Her full-field electroretinogram and electrooculogram were normal. An optical coherence tomography B-scan was performed for both eyes, revealing increased thickness of the retinal pigmented epithelium leading to multiple small pigmented epithelium detachments. The outer retina remained intact in both eyes. Spectral-domain optical coherence tomography angiography with split-spectrum amplitude decorrelation algorithm and 3 × 3 mm structural en face optical coherence tomography did not show macular lesions. Benign familial fleck retina belongs to a heterogenous group of so-called flecked retina syndromes, and should be considered in patients with yellowish-white retinal lesions without involvement of the macula.

131I activity quantification of gamma camera planar images

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Barquero, Raquel; Garcia, Hugo P.; Incio, Monica G.; Minguez, Pablo; Cardenas, Alexander; Martínez, Daniel; Lassmann, Michael

2017-02-01

A procedure to estimate the activity in target tissues in patients during the therapeutic administration of 131I radiopharmaceutical treatment for thyroid conditions (hyperthyroidism and differentiated thyroid cancer) using a gamma camera (GC) with a high energy (HE) collimator, is proposed. Planar images are acquired for lesions of different sizes r, and at different distances d, in two HE GC systems. Defining a region of interest (ROI) on the image of size r, total counts n g are measured. Sensitivity S (cps MBq-1) in each acquisition is estimated as the product of the geometric G and the intrinsic efficiency η 0. The mean fluence of 364 keV photons arriving at the ROI per disintegration G, is calculated with the MCNPX code, simulating the entire GC and the HE collimator. Intrinsic efficiency η 0 is estimated from a calibration measurement of a plane reference source of 131I in air. Values of G and S for two GC systems—Philips Skylight and Siemens e-cam—are calculated. The total range of possible sensitivity values in thyroidal imaging in the e-cam and skylight GC measure from 7 cps MBq-1 to 35 cps MBq-1, and from 6 cps MBq-1 to 29 cps MBq-1, respectively. These sensitivity values have been verified with the SIMIND code, with good agreement between them. The results have been validated with experimental measurements in air, and in a medium with scatter and attenuation. The counts in the ROI can be produced by direct, scatter and penetration photons. The fluence value for direct photons is constant for any r and d values, but scatter and penetration photons show different values related to specific r and d values, resulting in the large sensitivity differences found. The sensitivity in thyroidal GC planar imaging is strongly dependent on uptake size, and distance from the GC. An individual value for the acquisition sensitivity of each lesion can significantly alleviate the level of uncertainty in the measurement of thyroid uptake activity for each patient.

Statistical Correlation of Low-Altitude ENA Emissions with Geomagnetic Activity from IMAGE MENA Observations

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Mackler, D. A.; Jahn, J.- M.; Perez, J. D.; Pollock, C. J.; Valek, P. W.

2016-01-01

Plasma sheet particles transported Earthward during times of active magnetospheric convection can interact with exospheric/thermospheric neutrals through charge exchange. The resulting Energetic Neutral Atoms (ENAs) are free to leave the influence of the magnetosphere and can be remotely detected. ENAs associated with low-altitude (300-800 km) ion precipitation in the high-latitude atmosphere/ionosphere are termed low-altitude emissions (LAEs). Remotely observed LAEs are highly nonisotropic in velocity space such that the pitch angle distribution at the time of charge exchange is near 90deg. The Geomagnetic Emission Cone of LAEs can be mapped spatially, showing where proton energy is deposited during times of varying geomagnetic activity. In this study we present a statistical look at the correlation between LAE flux (intensity and location) and geomagnetic activity. The LAE data are from the MENA imager on the IMAGE satellite over the declining phase of solar cycle 23 (2000-2005). The SYM-H, AE, and Kp indices are used to describe geomagnetic activity. The goal of the study is to evaluate properties of LAEs in ENA images and determine if those images can be used to infer properties of ion precipitation. Results indicate a general positive correlation to LAE flux for all three indices, with the SYM-H showing the greatest sensitivity. The magnetic local time distribution of LAEs is centered about midnight and spreads with increasing activity. The invariant latitude for all indices has a slightly negative correlation. The combined results indicate LAE behavior similar to that of ion precipitation.

Statistical correlation of low-altitude ENA emissions with geomagnetic activity from IMAGE/MENA observations

Science.gov (United States)

Mackler, D. A.; Jahn, J.-M.; Perez, J. D.; Pollock, C. J.; Valek, P. W.

2016-03-01

Plasma sheet particles transported Earthward during times of active magnetospheric convection can interact with exospheric/thermospheric neutrals through charge exchange. The resulting Energetic Neutral Atoms (ENAs) are free to leave the influence of the magnetosphere and can be remotely detected. ENAs associated with low-altitude (300-800 km) ion precipitation in the high-latitude atmosphere/ionosphere are termed low-altitude emissions (LAEs). Remotely observed LAEs are highly nonisotropic in velocity space such that the pitch angle distribution at the time of charge exchange is near 90°. The Geomagnetic Emission Cone of LAEs can be mapped spatially, showing where proton energy is deposited during times of varying geomagnetic activity. In this study we present a statistical look at the correlation between LAE flux (intensity and location) and geomagnetic activity. The LAE data are from the MENA imager on the IMAGE satellite over the declining phase of solar cycle 23 (2000-2005). The SYM-H, AE, and Kp indices are used to describe geomagnetic activity. The goal of the study is to evaluate properties of LAEs in ENA images and determine if those images can be used to infer properties of ion precipitation. Results indicate a general positive correlation to LAE flux for all three indices, with the SYM-H showing the greatest sensitivity. The magnetic local time distribution of LAEs is centered about midnight and spreads with increasing activity. The invariant latitude for all indices has a slightly negative correlation. The combined results indicate LAE behavior similar to that of ion precipitation.

Active contour segmentation in dynamic medical imaging: application to nuclear cardiology

International Nuclear Information System (INIS)

Debreuve, Eric

2000-01-01

In emission imaging, nuclear medicine provides functional information about the organ of interest. In transmission imaging, it provides anatomical information whose goal may be the correction of physical phenomena that corrupt emission images. With both emission and transmission images, it is useful to know how to extract, either automatically or semi-automatically, the organs of interest and the body outline in the case of a large field of view. This is the aim of segmentation. We developed two active contour segmentation methods. They were implemented using level sets. The key point is the evolution velocity definition. First, we were interested in static transmission imaging of the thorax. The evolution velocity was heuristically defined and depended only on the acquired projections. The segmented transmission map was computed w/o reconstruction and could be advantageously used for attenuation correction. Then, we studied the segmentation of cardiac gated sequences. The developed space-time segmentation method results from the minimization of a variational criterion which takes into account the whole sequence. The computed segmentation could be used for calculating physiological parameters. As an illustration, we computed the ejection fraction. Finally, we exploited some level set properties to develop a non-rigid, non-parametric, and geometric registration method. We applied it for kinetic compensation of cardiac gated sequences. The registered images were then added together providing an image with noise characteristics similar to a cardiac static image but w/o motion-induced blurring. (author)

Noninvasive cardiac activation imaging of ventricular arrhythmias during drug-induced QT prolongation in the rabbit heart.

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Han, Chengzong; Pogwizd, Steven M; Killingsworth, Cheryl R; Zhou, Zhaoye; He, Bin

2013-10-01

Imaging myocardial activation from noninvasive body surface potentials promises to aid in both cardiovascular research and clinical medicine. To investigate the ability of a noninvasive 3-dimensional cardiac electrical imaging technique for characterizing the activation patterns of dynamically changing ventricular arrhythmias during drug-induced QT prolongation in rabbits. Simultaneous body surface potential mapping and 3-dimensional intracardiac mapping were performed in a closed-chest condition in 8 rabbits. Data analysis was performed on premature ventricular complexes, couplets, and torsades de pointes (TdP) induced during intravenous administration of clofilium and phenylephrine with combinations of various infusion rates. The drug infusion led to a significant increase in the QT interval (from 175 ± 7 to 274 ± 31 ms) and rate-corrected QT interval (from 183 ± 5 to 262 ± 21 ms) during the first dose cycle. All the ectopic beats initiated by a focal activation pattern. The initial beat of TdPs arose at the focal site, whereas the subsequent beats were due to focal activity from different sites or 2 competing focal sites. The imaged results captured the dynamic shift of activation patterns and were in good correlation with the simultaneous measurements, with a correlation coefficient of 0.65 ± 0.02 averaged over 111 ectopic beats. Sites of initial activation were localized to be ~5 mm from the directly measured initiation sites. The 3-dimensional cardiac electrical imaging technique could localize the origin of activation and image activation sequence of TdP during QT prolongation induced by clofilium and phenylephrine in rabbits. It offers the potential to noninvasively investigate the proarrhythmic effects of drug infusion and assess the mechanisms of arrhythmias on a beat-to-beat basis. © 2013 Heart Rhythm Society. All rights reserved.

Imaging active topological defects in carbon nanotubes

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Suenaga, Kazu; Wakabayashi, Hideaki; Koshino, Masanori; Sato, Yuta; Urita, Koki; Iijima, Sumio

2007-06-01

A single-walled carbon nanotube (SWNT) is a wrapped single graphene layer, and its plastic deformation should require active topological defects-non-hexagonal carbon rings that can migrate along the nanotube wall. Although in situ transmission electron microscopy (TEM) has been used to examine the deformation of SWNTs, these studies deal only with diameter changes and no atomistic mechanism has been elucidated experimentally. Theory predicts that some topological defects can form through the Stone-Wales transformation in SWNTs under tension at 2,000 K, and could act as a dislocation core. We demonstrate here, by means of high-resolution (HR)-TEM with atomic sensitivity, the first direct imaging of pentagon-heptagon pair defects found in an SWNT that was heated at 2,273 K. Moreover, our in situ HR-TEM observation reveals an accumulation of topological defects near the kink of a deformed nanotube. This result suggests that dislocation motions or active topological defects are indeed responsible for the plastic deformation of SWNTs.

Active instrumental guidance in interventional magnetic resonance imaging

International Nuclear Information System (INIS)

Wildermuth, S.; Erhart, P.; Leung, D.A.; Goehde, S.; Schoenenberger, A.; Debatin, J.F.

1998-01-01

Purpose: An active MR-based guidance system for visualisation of invasive instruments is described. Methods: The principle of MR tracking is based on the integration of a miniaturised coil into the tip of the instrument itself. A phantom experiment was designed to demonstrate the localising accuracy of this technique. In [dition, bicompatibility and warming effects were evaluated. Preliminary intravascular applications that were performed in animal experiments under MR guidance included embolisation, vascular occlusion as well as transjugular intrahepatic punctures. Percutaneous biopsies, cholecystostomies and laparoscopic applications were also evaluated with MR tracking. Results: Phantom experiments confirmed an excellent localisation accuracy of MR tracking compared to conventional r[iography. At a field strength of 0.5 T, the temperature increase remained below 2 C. Results of phantom experiments revealed a potential of significant heating dependent on the sequence parameters employed. MR tracking allowed a robust, simultaneously biplanar visualisation of the instrument tips in real time. Based on MR 'ro[ map' images, various intravascular and percutaneous interventions were successfully performed in vivo under MR guidance. Conclusions: MR tracking is a flexible concept permitting monitoring in the guidance of instruments in an MR environment. Various preliminary in vitro and in vivo experiments demonstrate safety, localisation accuracy and feasibility of this biplanar localisation technique in real time. (orig.) [de

Comparative study on the performance of textural image features for active contour segmentation.

Science.gov (United States)

Moraru, Luminita; Moldovanu, Simona

2012-07-01

We present a computerized method for the semi-automatic detection of contours in ultrasound images. The novelty of our study is the introduction of a fast and efficient image function relating to parametric active contour models. This new function is a combination of the gray-level information and first-order statistical features, called standard deviation parameters. In a comprehensive study, the developed algorithm and the efficiency of segmentation were first tested for synthetic images. Tests were also performed on breast and liver ultrasound images. The proposed method was compared with the watershed approach to show its efficiency. The performance of the segmentation was estimated using the area error rate. Using the standard deviation textural feature and a 5×5 kernel, our curve evolution was able to produce results close to the minimal area error rate (namely 8.88% for breast images and 10.82% for liver images). The image resolution was evaluated using the contrast-to-gradient method. The experiments showed promising segmentation results.

Contrast-enhanced ultrasound imaging of active bleeding associated with hepatic and splenic trauma.

Science.gov (United States)

Lv, F; Tang, J; Luo, Y; Li, Z; Meng, X; Zhu, Z; Li, T

2011-10-01

The aim of this study was to evaluate contrast-enhanced ultrasound (CEUS) imaging of active bleeding from hepatic and splenic trauma. Three hundred and ninety-two patients with liver or/and spleen trauma (179 liver and 217 spleen injuries), who underwent CEUS examinations following contrast-enhanced computed tomography (CT), were enrolled in this retrospective study over a period of >4 years. CEUS detected contrast medium extravasation or pooling in 16% (63/396) of liver or spleen lesions in 61 patients, which was confirmed by contrast-enhanced CT. Special attention was paid to observing the presence, location, and characteristics of the extravasated or pooled contrast medium. The CEUS detection rate for active bleeding was not different from that of contrast-enhanced CT (p=0.333). Information from surgery, minimally invasive treatment and conservative treatment was used as reference standard, and the sensitivities of the two techniques were not different (p=0.122). Of 63 lesions in 61 patients, CEUS showed that 74.6% (47/63) (21 liver lesions and 26 spleen lesions) presented contrast medium extravasation or pooling, both in the organ and out the capsule, in 14.3% (9/63) and only outside the capsule in 11.1% (7/63). CEUS imaging of active bleeding from hepatic and splenic trauma presented various characteristics, and the sizes and shapes of the active bleeding due to contrast medium extravasation or pooling were variable. CEUS can show the active bleeding associated with hepatic and splenic trauma with various imaging characteristics, thus making it possible to diagnose active bleeding using CEUS.

Triple Active Antiretroviral Regimen Including Enfuvirtide Via the Biojector is Effective and Safe

Directory of Open Access Journals (Sweden)

Mona Loutfy

2007-01-01

Full Text Available For full HIV virological suppression, three fully active antiretroviral agents are required. New drug classes should be included to ensure that agents are fully active. The addition of enfuvirtide and efavirenz to the present patient’s new antiretroviral regimen ensured that two fully active agents were in use in the setting of a moderate degree of nucleoside resistance and a high level of protease resistance, and where non-nucleoside reverse transcriptase inhibitors were still fully active. Both viral load and CD4 count responded favourably to this regimen. The patient received support from physicians and clinic staff in the introduction and use of enfuvirtide. To reduce injection site reactions, a needle-free injection system (Biojector proved effective.

THE EFFECT OF SOCIAL MEDIA MARKETING ACTIVITIES ON BRAND AWARENESS, BRAND IMAGE AND BRAND LOYALTY

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Yusuf BİLGİN

2018-04-01

Full Text Available The aim of this research is to examine the effect of social media marketing activities on brand awareness, brand image and brand loyalty. In addition, it has been aimed to analyze the effect of brand awareness and brand image on brand loyalty in this research. The population of the research consists of the consumers who actively follow five brands with the highest social score according to the Marketing Turkey social media brand performance data on social media communication channels such as Facebook, Twitter and Instagram. In this research, quantitative method has been used and research data has been obtained via online questionnaires shared on social media from 547 brand followers with applying convenience sampling method. The obtained data have been analyzed by structural equation modeling (SEM. As a result of the analysis, social media marketing activities have been found as effective factors on brand image and brand loyalty, besides it has been determined that the most obvious effect seen on brand awareness. In addition, it has been found out that brand awareness and brand image have a significant effect on brand loyalty. Furthermore, in the research, it has been achieved that the brand awareness has a limited effect on the brand image.

The relationship between physical activity and self-image and problem behaviour among adolescents.

Science.gov (United States)

Kirkcaldy, B D; Shephard, R J; Siefen, R G

2002-11-01

Although there are a vast array of studies which have demonstrated the psychological and physical health benefits of regular aerobic exercise for adults, few studies have focussed on children and adolescents. The current study examined associations between the extent of participation in endurance sport, and self-report data on self-image, physical and psychological health and overall lifestyle in a large representative sample of German high-school students. Almost 1000 German adolescents (aged 14-18 years) were administered a comprehensive series of questionnaires aimed at assessing anxiety-depression, trait addiction, smoking and drinking behaviour, physical ill-health reports, and self-perception of self-image, parental acceptance and educational attainment. Regular practice of endurance exercise was related to a more favourable self-image. There was a strong association between participation in sports and the type of personality that tends to be resistant to drug and alcohol addiction. Physical exercise was further significantly related to scores for physical and psychological well-being. Adolescents who engaged regularly in physical activity were characterised by lower anxiety-depression scores, and displayed much less social behavioural inhibition than their less active counterparts. It is likely that discussion of recreational or exercise involvement may provide a useful point of entry for facilitating dialogue among adolescents about concerns relating to body image and self-esteem. In terms of psychotherapeutic applications, physical activity has many additional rewards for adolescents. It is probable that by promoting physical fitness, increased physical performance, lessening body mass and promoting a more favourable body shape and structure, exercise will provide more positive social feedback and recognition from peer groups, and this will subsequently lead to improvement in an individual's self-image.

Body Image and Nutritional Status Are Associated with Physical Activity in Men and Women: The ELSA-Brasil Study.

Science.gov (United States)

Coelho, Carolina G; Giatti, Luana; Molina, Maria D C B; Nunes, Maria A A; Barreto, Sandhi M

2015-05-29

The association of body image dissatisfaction and obesity with physical activity is likely to differ according to gender. To investigate this hypothesis, we conducted a cross-sectional study among the ELSA-Brasil cohort members aged 34-65 years (n=13,286). The body image dissatisfaction was present even among normal weight individuals of both sexes and was associated with lesser chances of practicing moderate physical activity in women and intense physical activity in men. Men and women with central obesity were less prone to practice physical activity of high or moderate intensity. Overweight and obese men were more likely to report vigorous physical activity while obese women were less likely to report this level of physical activity. Body images as well as nutritional status are related to physical activity in both sexes, but the association with physical activity differs by gender.

The impact of verbal framing on brain activity evoked by emotional images.

Science.gov (United States)

Kisley, Michael A; Campbell, Alana M; Larson, Jenna M; Naftz, Andrea E; Regnier, Jesse T; Davalos, Deana B

2011-12-01

Emotional stimuli generally command more brain processing resources than non-emotional stimuli, but the magnitude of this effect is subject to voluntary control. Cognitive reappraisal represents one type of emotion regulation that can be voluntarily employed to modulate responses to emotional stimuli. Here, the late positive potential (LPP), a specific event-related brain potential (ERP) component, was measured in response to neutral, positive and negative images while participants performed an evaluative categorization task. One experimental group adopted a "negative frame" in which images were categorized as negative or not. The other adopted a "positive frame" in which the exact same images were categorized as positive or not. Behavioral performance confirmed compliance with random group assignment, and peak LPP amplitude to negative images was affected by group membership: brain responses to negative images were significantly reduced in the "positive frame" group. This suggests that adopting a more positive appraisal frame can modulate brain activity elicited by negative stimuli in the environment.

Active laser radar (lidar) for measurement of corresponding height and reflectance images

Science.gov (United States)

Froehlich, Christoph; Mettenleiter, M.; Haertl, F.

1997-08-01

For the survey and inspection of environmental objects, a non-tactile, robust and precise imaging of height and depth is the basis sensor technology. For visual inspection,surface classification, and documentation purposes, however, additional information concerning reflectance of measured objects is necessary. High-speed acquisition of both geometric and visual information is achieved by means of an active laser radar, supporting consistent 3D height and 2D reflectance images. The laser radar is an optical-wavelength system, and is comparable to devices built by ERIM, Odetics, and Perceptron, measuring the range between sensor and target surfaces as well as the reflectance of the target surface, which corresponds to the magnitude of the back scattered laser energy. In contrast to these range sensing devices, the laser radar under consideration is designed for high speed and precise operation in both indoor and outdoor environments, emitting a minimum of near-IR laser energy. It integrates a laser range measurement system and a mechanical deflection system for 3D environmental measurements. This paper reports on design details of the laser radar for surface inspection tasks. It outlines the performance requirements and introduces the measurement principle. The hardware design, including the main modules, such as the laser head, the high frequency unit, the laser beam deflection system, and the digital signal processing unit are discussed.the signal processing unit consists of dedicated signal processors for real-time sensor data preprocessing as well as a sensor computer for high-level image analysis and feature extraction. The paper focuses on performance data of the system, including noise, drift over time, precision, and accuracy with measurements. It discuses the influences of ambient light, surface material of the target, and ambient temperature for range accuracy and range precision. Furthermore, experimental results from inspection of buildings, monuments

Italy: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

International Nuclear Information System (INIS)

Zoppi, Marco

2012-01-01

Materials characterization, through non-invasive techniques, represents an important strategic tool in the non-destructive quantitative analysis of artefacts of archaeological and historical interest. In fact, thanks to the high penetration power of thermal neutrons in dense matter, bulk analysis of massive findings, characteristic of archaeological activity, can be nowadays carried out in an almost straightforward way, especially on metal samples. By means of neutron diffraction, it is possible to obtain, without any need of sampling, the average bulk phase composition of the specimen and to reveal the hidden presence of mineralisation phases, which, in turn, gives a deep information on its preservation status. Moreover, a detailed analysis of the peak shape, can shed light on smelting and smithing methods, as well as on the amount of mechanical work that was originally carried out on the sample. Neutron imaging techniques, have developed to such an extent that, today, it is possible to reconstruct tomographic images down to ≅30 μm space resolution. In addition, thanks to the developing techniques of energy selective neutron imaging and tomography the scenario opens over a wealth of futuristic applications, thanks to the enhanced contrast inherent in this technique. At present, these energy selective techniques are only limited by the performances of the device needed to select the energy (and wavelength) of the incident neutron beam: i.e. a rotating disk velocity selector and double monochromator. The possibility of enhancing this technique by fully exploiting the Time of Flight technique could improve dramatically the energy resolution and consequently the range of possible “contrast enhancement” possibilities. What we propose is a research activity using energy selective neutron imaging, applied to cultural heritage metal artefacts, to study the historical evolution of iron production on a world basis, i.e. including European, middle-east, Indian, and

Peptidase inhibitors reduce opiate narcotic withdrawal signs, including seizure activity, in the rat.

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Pinsky, C; Dua, A K; LaBella, F S

1982-07-15

Narcotic withdrawal was precipitated by administration of naloxone in a low dose at 2 h after the final dose of morphine in a 9-day dependency-inducing schedule. Withdrawal was characterized by leaps, increased nocifensor activity and by cerebral cortical epileptiform activity, the latter not generally reported to be prominent in narcotic withdrawal. Single large doses of morphine did not provoke epileptiform activity at 2 h postinjection but did induce an acute opioid dependency wherein a moderately high dose of naloxone, ineffective in non-dependent rats, provoked upward leaping and electrocortical epileptiform activity. Pretreatment of the 9-day dependent rats with peptidase inhibitors, administered intracerebroventricularly, significantly reduced withdrawal severity including the epileptiform activity. We propose that peptidase inhibitors protect certain species of endogenous opioids and/or other neuropeptides that tend to suppress expression of the narcotic withdrawal syndrome. Furthermore, our findings suggest that epileptiform activity is a nascent form of cerebral activity hitherto largely unnoticed in narcotic withdrawal and that neuropeptides may be involved in certain epileptic states.

Functional imaging reveals movement preparatory activity in the vegetative state

Directory of Open Access Journals (Sweden)

Tristan A Bekinschtein

2011-01-01

Full Text Available The Vegetative State (VS is characterized by the absence of awareness of self or the environment and preserved autonomic functions. The diagnosis relies critically on the lack of consistent signs of purposeful behavior in response to external stimulation. Yet, given that patients with disorders of consciousness often exhibit fragmented movement patterns, voluntary actions may go unnoticed. Here we designed a simple motor paradigm that could potentially detect residual conscious awareness in VS patients with mild to severe brain damage by examining the neural correlates of motor preparation in response to verbal commands. Twenty-four patients who met the diagnostic criteria for VS were recruited for this study. Eleven of these patients showing preserved auditory evoked potentials underwent functional magnetic resonance imaging (fMRI to test for basic speech processing. Five of these patients, who showed word related activity, were included in a second fMRI study aimed at detecting functional changes in premotor cortex elicited by specific verbal instructions to move either their left or their right hand. Despite the lack of overt muscle activity, two patients out of five activated the dorsal premotor cortex contralateral to the instructed hand, consistent with movement preparation. Given that movement preparation in response to a motor command is a sign of purposeful behavior, our results are consistent with residual conscious awareness in these patients. We believe that the identification of positive results with fMRI using this simple task, may complement the clinical assessment by helping attain a more precise diagnosis in patients with disorders of consciousness.

Activated sludge characterization through microscopy: A review on quantitative image analysis and chemometric techniques

Energy Technology Data Exchange (ETDEWEB)

Mesquita, Daniela P. [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Amaral, A. Luís [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra (Portugal); Ferreira, Eugénio C., E-mail: ecferreira@deb.uminho.pt [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

2013-11-13

Graphical abstract: -- Highlights: •Quantitative image analysis shows potential to monitor activated sludge systems. •Staining techniques increase the potential for detection of operational problems. •Chemometrics combined with quantitative image analysis is valuable for process monitoring. -- Abstract: In wastewater treatment processes, and particularly in activated sludge systems, efficiency is quite dependent on the operating conditions, and a number of problems may arise due to sludge structure and proliferation of specific microorganisms. In fact, bacterial communities and protozoa identification by microscopy inspection is already routinely employed in a considerable number of cases. Furthermore, quantitative image analysis techniques have been increasingly used throughout the years for the assessment of aggregates and filamentous bacteria properties. These procedures are able to provide an ever growing amount of data for wastewater treatment processes in which chemometric techniques can be a valuable tool. However, the determination of microbial communities’ properties remains a current challenge in spite of the great diversity of microscopy techniques applied. In this review, activated sludge characterization is discussed highlighting the aggregates structure and filamentous bacteria determination by image analysis on bright-field, phase-contrast, and fluorescence microscopy. An in-depth analysis is performed to summarize the many new findings that have been obtained, and future developments for these biological processes are further discussed.

SU-F-J-86: Method to Include Tissue Dose Response Effect in Deformable Image Registration

Energy Technology Data Exchange (ETDEWEB)

Zhu, J; Liang, J; Chen, S; Qin, A; Yan, D [Beaumont Health Systeml, Royal Oak, MI (United States)

2016-06-15

Purpose: Organ changes shape and size during radiation treatment due to both mechanical stress and radiation dose response. However, the dose response induced deformation has not been considered in conventional deformable image registration (DIR). A novel DIR approach is proposed to include both tissue elasticity and radiation dose induced organ deformation. Methods: Assuming that organ sub-volume shrinkage was proportional to the radiation dose induced cell killing/absorption, the dose induced organ volume change was simulated applying virtual temperature on each sub-volume. Hence, both stress and heterogeneity temperature induced organ deformation. Thermal stress finite element method with organ surface boundary condition was used to solve deformation. Initial boundary correspondence on organ surface was created from conventional DIR. Boundary condition was updated by an iterative optimization scheme to minimize elastic deformation energy. The registration was validated on a numerical phantom. Treatment dose was constructed applying both the conventional DIR and the proposed method using daily CBCT image obtained from HN treatment. Results: Phantom study showed 2.7% maximal discrepancy with respect to the actual displacement. Compared with conventional DIR, subvolume displacement difference in a right parotid had the mean±SD (Min, Max) to be 1.1±0.9(−0.4∼4.8), −0.1±0.9(−2.9∼2.4) and −0.1±0.9(−3.4∼1.9)mm in RL/PA/SI directions respectively. Mean parotid dose and V30 constructed including the dose response induced shrinkage were 6.3% and 12.0% higher than those from the conventional DIR. Conclusion: Heterogeneous dose distribution in normal organ causes non-uniform sub-volume shrinkage. Sub-volume in high dose region has a larger shrinkage than the one in low dose region, therefore causing more sub-volumes to move into the high dose area during the treatment course. This leads to an unfavorable dose-volume relationship for the normal organ

Accuracy and Precision of Radioactivity Quantification in Nuclear Medicine Images

Science.gov (United States)

Frey, Eric C.; Humm, John L.; Ljungberg, Michael

2012-01-01

The ability to reliably quantify activity in nuclear medicine has a number of increasingly important applications. Dosimetry for targeted therapy treatment planning or for approval of new imaging agents requires accurate estimation of the activity in organs, tumors, or voxels at several imaging time points. Another important application is the use of quantitative metrics derived from images, such as the standard uptake value commonly used in positron emission tomography (PET), to diagnose and follow treatment of tumors. These measures require quantification of organ or tumor activities in nuclear medicine images. However, there are a number of physical, patient, and technical factors that limit the quantitative reliability of nuclear medicine images. There have been a large number of improvements in instrumentation, including the development of hybrid single-photon emission computed tomography/computed tomography and PET/computed tomography systems, and reconstruction methods, including the use of statistical iterative reconstruction methods, which have substantially improved the ability to obtain reliable quantitative information from planar, single-photon emission computed tomography, and PET images. PMID:22475429

A clustering model proposal for activity optimization vs. image quality. Application in HMPAO-99mTc brain SPECT

International Nuclear Information System (INIS)

Perez, M.; Diaz, O.; Estevez, E.; Roque, R.; Hernandez, C.

2008-01-01

A method based on clustering analysis and image quality discriminant functions is tested over HMPAO- 99m Tc -SPECT images to optimize image quality vs. administered activity to patient. Signal-to-Noise ratios and Signal-to-Background ratios in each transaxial slice were measured over the images and used as image quality objective indexes. They were employed to develop image quality classification using a model of three clusters (k-mean Cluster Technique). The mathematical classification was compared with the subjective image quality evaluation, following expert observer criterion. Linear image quality discrimination was developed using the results of the cluster classification and taking as independent variables: the characteristics of the patients (sex, age and weight) and the radiopharmaceutical (labelling yield and administered activity). The dependent variables in the discriminant functions were the cluster centroids. The objective of this procedure was assigning a statistical weight to each image quality determinant variable for the optimization purpose. The method was applied in 30 brain SPECT images, acquired under different activities (400 MBq, 600 MBq, 800 MBq and 1000 MBq as reference), with a Sopha gamma camera, mean-resolution - general purpose - parallel-hole collimator, acquisition matrix 128 x 128 pixels and reconstruction following Filter - Back - Projection Algorithm. We looked for the minimum activity that guaranty most of the cases classified into the cluster with the best image quality (optimization criterion). The value of 800 MBq was the optimum obtained after application of the above methodology for the technology used. The labelling yield and the weight of the patients were the main parameters which determined image quality in clusters, as well as the processing digital filter used. The reduction in the effective dose, as a consequence of this procedure implementation, was also analysed. (author)

Evaluation of rectus extraocular muscles using dynamic contrast-enhanced MR imaging in patients with Graves' ophthalmopathy for assessment of disease activity

International Nuclear Information System (INIS)

Jiang, Hong; Wang, Zhenchang; Xian, Junfang; Li, Jing; Chen, Qinghua; Ai, Likun

2012-01-01

Background. It is important to assess the activity of Graves' ophthalmopathy (GO) for planning optimal treatment strategy. Dynamic contrast-enhanced MR imaging (DCE-MRI) is a technique for assessment of microcirculation status. The correlation between disease activity and the microcirculation characteristics of extraocular muscles (EOMs) has been demonstrated in GO. Purpose. To investigate the changes of rectus EOMs in patients with active vs. inactive GO using DCE-MRI, and to evaluate the value of DCE-MRI in assessing the activity of GO. Material and Methods. Rectus EOMs of 20 healthy controls, 18 patients with active GO, and 16 patients with inactive GO were studied. The signal intensity (SI) of rectus EOMs on T 2 W images was evaluated. Regions of interest were placed on each rectus on DCE-MRI images. The DCE-MRI parameters including time to peak enhancement (T peak ), enhancement ratio (ER), and wash-out ratio (WR) were calculated. Results. There were significant differences in SI and T peak , ER and WR values among the three groups (P = 0.000). However, there was no significant difference in SI between the active and inactive groups (P = 0.07). Tpeak values of each rectus were significantly increased in inactive group compared with the active group (P peak ), maximum ER (maxER) and maximum WR (maxWR) (P peak , maxER and maxWR were 156.98s, 1.31 and 13.50% respectively, giving positive predictive values of 68.00%, 88.90%, and 94.44% for the assessment of disease activity. Conclusion. DCE-MRI could demonstrate the micro circulatory changes of rectus EOMs in both active and inactive GO, and this MRI method is a useful tool in differentiating active from inactive GO

Transferring Biomarker into Molecular Probe: Melanin Nanoparticle as a Naturally Active Platform for Multimodality Imaging

OpenAIRE

Fan, Quli; Cheng, Kai; Hu, Xiang; Ma, Xiaowei; Zhang, Ruiping; Yang, Min; Lu, Xiaomei; Xing, Lei; Huang, Wei; Gambhir, Sanjiv Sam; Cheng, Zhen

2014-01-01

Developing multifunctional and easily prepared nanoplatforms with integrated different modalities is highly challenging for molecular imaging. Here, we report the successful transfer of an important molecular target, melanin, into a novel multimodality imaging nanoplatform. Melanin is abundantly expressed in melanotic melanomas and thus has been actively studied as a target for melanoma imaging. In our work, the multifunctional biopolymer nanoplatform based on ultrasmall (

MR constrained simultaneous reconstruction of activity and attenuation maps in brain TOF-PET/MR imaging

Energy Technology Data Exchange (ETDEWEB)

Mehranian, Abolfazl; Zaidi, Habib [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva (Switzerland)

2014-07-29

The maximum likelihood estimation of attenuation and activity (MLAA) algorithm has been proposed to jointly estimate activity and attenuation from emission data only. Salomon et al employed the MLAA to estimate activity and attenuation from time-of-flight PET data with spatial MR prior information on attenuation. Recently, we proposed a novel algorithm to impose both spatial and statistical constraints on attenuation estimation within the MLAA algorithm using Dixon MR images and a constrained Gaussian mixture model (GMM). In this study, we compare the proposed algorithm with MLAA and MLAA-Salomon in brain TOF-PET/MR imaging.

MR constrained simultaneous reconstruction of activity and attenuation maps in brain TOF-PET/MR imaging

International Nuclear Information System (INIS)

Mehranian, Abolfazl; Zaidi, Habib

2014-01-01

The maximum likelihood estimation of attenuation and activity (MLAA) algorithm has been proposed to jointly estimate activity and attenuation from emission data only. Salomon et al employed the MLAA to estimate activity and attenuation from time-of-flight PET data with spatial MR prior information on attenuation. Recently, we proposed a novel algorithm to impose both spatial and statistical constraints on attenuation estimation within the MLAA algorithm using Dixon MR images and a constrained Gaussian mixture model (GMM). In this study, we compare the proposed algorithm with MLAA and MLAA_Salomon in brain TOF-PET/MR imaging.

Detection of active bile leak with Gd-EOB-DTPA enhanced MR cholangiography: Comparison of 20–25 min delayed and 60–180 min delayed images

International Nuclear Information System (INIS)

Cieszanowski, Andrzej; Stadnik, Anna; Lezak, Aleksandra; Maj, Edyta; Zieniewicz, Krzysztof; Rowinska-Berman, Katarzyna; Grudzinski, Ireneusz P.; Krawczyk, Marek; Rowiński, Olgierd

2013-01-01

Objectives: The purpose of this study was to assess the value of contrast-enhanced magnetic resonance cholangiography (MRC) performed in different time delays after injection of gadoxetic acid disodium (Gd-EOB-DTPA) for the diagnosis of active bile leak. Methods: This retrospective analysis included Gd-EOB-DTPA enhanced MR images of 34 patients suspected of bile leak. Images were acquired 20–25 min after Gd-EOB-DTPA injection. If there was inadequate contrast in the bile ducts then delayed images after 60–90 min and 150–180 min were obtained. Results were correlated with intraoperative findings, ERCP results, clinical data, laboratory tests, and follow-up examinations. Results: Gd-EOB-DTPA enhanced MRC yielded an overall sensitivity of 96.4%, specificity of 100% and accuracy of 97.1% for the diagnosis of an active bile leak. The sensitivity of 20–25 min delayed MR images was 42.9%, of combined 20–25 min and 60–90 min delayed images was 92.9% and of combined 20–25 min, 60–90 min and 150–180 min delayed images was 96.4%. Conclusions: Gd-EOB-DTPA enhanced MRC utilizing delayed phase images was effective for detecting the presence and location of active bile leaks. The images acquired 60–180 min post-injection enabled identification of bile leaks even in patients with a dilated biliary system or moderate liver dysfunction

Dynamic contrast-enhanced 3-T magnetic resonance imaging: a method for quantifying disease activity in early polyarthritis

Energy Technology Data Exchange (ETDEWEB)

Navalho, Marcio [Faculdade de Medicina da Universidade de Lisboa, Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon (Portugal); Hospital da Luz, Radiology Department, Lisbon (Portugal); Hospital da Luz, Centro de Imagiologia, Lisbon (Portugal); Resende, Catarina [Hospital da Luz, Rheumatology Department, Lisbon (Portugal); Hospital de Santa Maria, Rheumatology Department, Centro Hospitalar de Lisboa Norte, EPE, Lisbon (Portugal); Rodrigues, Ana Maria; Fonseca, Joao Eurico; Canhao, Helena [Faculdade de Medicina da Universidade de Lisboa, Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon (Portugal); Hospital de Santa Maria, Rheumatology Department, Centro Hospitalar de Lisboa Norte, EPE, Lisbon (Portugal); Gaspar, Augusto [Hospital da Luz, Radiology Department, Lisbon (Portugal); Campos, Jorge [Hospital de Santa Maria, Radiology Department, Centro Hospitalar de Lisboa Norte, EPE, Lisbon (Portugal)

2012-01-15

To determine whether measurement of synovial enhancement and thickness quantification parameters with 3.0-Tesla magnetic resonance imaging (3-T MRI) can reliably quantify disease activity in patients with early polyarthritis. Eighteen patients (16 women, 2 men; mean age 46 years) with early polyarthritis with less than 12 months of symptoms were included. MRI examination using 3-T device was performed by a new approach including both wrists and hands simultaneously in the examination field-of-view. MRI scoring of disease activity included quantification of synovial enhancement with simple measurements such as rate of early enhancement (REE; REE{sub 57} = S{sub 57}/S{sub 200}, where S{sub 57} and S{sub 200} are the signal intensities 57 s and 200 s after gadolinium injection) and rate of relative enhancement (RE; RE = S{sub 200} - S{sub 0}). Both wrists and hands were scored according to the Rheumatoid Arthritis MRI Scoring System (RAMRIS) for synovitis. Disease activity was clinically assessed by the 28-joint Disease Activity Score (DAS28). DAS28 score was strongly correlated with RE (r = 0.8331, p < 0.0001), REE (r = 0.8112, p < 0.0001), and RAMRIS score for synovitis (r = 0.7659, p < 0.0002). An REE score above 0.778 accurately identified patients with clinically active disease (sensitivity 92%; specificity 67%; p < 0.05). A statistically significant difference was observed in the RE, REE, and RAMRIS scores for synovitis between patients with active and inactive disease (p < 0.05). Our findings support the use of 3-T dynamic contrast-enhanced MRI for precise quantification of disease activity and for discriminating active disease from inactive disease in early polyarthritis. (orig.)

The association between sexual satisfaction and body image in women.

Science.gov (United States)

Pujols, Yasisca; Seal, Brooke N; Meston, Cindy M

2010-02-01

Although sexual functioning has been linked to sexual satisfaction, it only partially explains the degree to which women report being sexually satisfied. Other factors include quality of life, relational variables, and individual factors such as body image. Of the few studies that have investigated the link between body image and sexual satisfaction, most have considered body image to be a single construct and have shown mixed results. The present study assessed multiple body image variables in order to better understand which aspects of body image influence multiple domains of sexual satisfaction, including sexual communication, compatibility, contentment, personal concern, and relational concern in a community sample of women. Women between the ages of 18 and 49 years in sexual relationships (N = 154) participated in an Internet survey that assessed sexual functioning, five domains of sexual satisfaction, and several body image variables. Body image variables included the sexual attractiveness, weight concern, and physical condition subscales of the Body Esteem Scale, the appearance-based subscale of the Cognitive Distractions During Sexual Activity Scale, and body mass index. Total score of the Sexual Satisfaction Scale for Women was the main outcome measure. Sexual functioning was measured by a modified Female Sexual Function Index. Consistent with expectations, correlations indicated significant positive relationships between sexual functioning, sexual satisfaction, and all body image variables. A multiple regression analysis revealed that sexual satisfaction was predicted by high body esteem and low frequency of appearance-based distracting thoughts during sexual activity, even after controlling for sexual functioning status. Several aspects of body image, including weight concern, physical condition, sexual attractiveness, and thoughts about the body during sexual activity predict sexual satisfaction in women. The findings suggest that women who experience

Active thermography and post-processing image enhancement for recovering of abraded and paint-covered alphanumeric identification marks

Science.gov (United States)

Montanini, R.; Quattrocchi, A.; Piccolo, S. A.

2016-09-01

Alphanumeric marking is a common technique employed in industrial applications for identification of products. However, the realised mark can undergo deterioration, either by extensive use or voluntary deletion (e.g. removal of identification numbers of weapons or vehicles). For recovery of the lost data many destructive or non-destructive techniques have been endeavoured so far, which however present several restrictions. In this paper, active infrared thermography has been exploited for the first time in order to assess its effectiveness in restoring paint covered and abraded labels made by means of different manufacturing processes (laser, dot peen, impact, cold press and scribe). Optical excitation of the target surface has been achieved using pulse (PT), lock-in (LT) and step heating (SHT) thermography. Raw infrared images were analysed with a dedicated image processing software originally developed in Matlab™, exploiting several methods, which include thermographic signal reconstruction (TSR), guided filtering (GF), block guided filtering (BGF) and logarithmic transformation (LN). Proper image processing of the raw infrared images resulted in superior contrast and enhanced readability. In particular, for deeply abraded marks, good outcomes have been obtained by application of logarithmic transformation to raw PT images and block guided filtering to raw phase LT images. With PT and LT it was relatively easy to recover labels covered by paint, with the latter one providing better thermal contrast for all the examined targets. Step heating thermography never led to adequate label identification instead.

Bio-imaging and visualization for patient-customized simulations

CERN Document Server

Luo, Xiongbiao; Li, Shuo

2014-01-01

This book contains the full papers presented at the MICCAI 2013 workshop Bio-Imaging and Visualization for Patient-Customized Simulations (MWBIVPCS 2013). MWBIVPCS 2013 brought together researchers representing several fields, such as Biomechanics, Engineering, Medicine, Mathematics, Physics and Statistic. The contributions included in this book present and discuss new trends in those fields, using several methods and techniques, including the finite element method, similarity metrics, optimization processes, graphs, hidden Markov models, sensor calibration, fuzzy logic, data mining, cellular automation, active shape models, template matching and level sets. These serve as tools to address more efficiently different and timely applications involving signal and image acquisition, image processing and analysis, image segmentation, image registration and fusion, computer simulation, image based modelling, simulation and surgical planning, image guided robot assisted surgical and image based diagnosis.  This boo...

Functional photoacoustic imaging to observe regional brain activation induced by cocaine hydrochloride

Science.gov (United States)

Jo, Janggun; Yang, Xinmai

2011-09-01

Photoacoustic microscopy (PAM) was used to detect small animal brain activation in response to drug abuse. Cocaine hydrochloride in saline solution was injected into the blood stream of Sprague Dawley rats through tail veins. The rat brain functional change in response to the injection of drug was then monitored by the PAM technique. Images in the coronal view of the rat brain at the locations of 1.2 and 3.4 mm posterior to bregma were obtained. The resulted photoacoustic (PA) images showed the regional changes in the blood volume. Additionally, the regional changes in blood oxygenation were also presented. The results demonstrated that PA imaging is capable of monitoring regional hemodynamic changes induced by drug abuse.

Dynamic gadolinium-enhanced MR imaging in active and inactive immunoinflammatory gonarthritis

DEFF Research Database (Denmark)

Østergaard, Mikkel; Lorenzen, I; Henriksen, O

1994-01-01

examined 16 clinically active (CAG), 7 clinically inactive (CIG) and 4 healthy knees. The synovium of a preselected slice was outlined. Its area and relative signal intensity increase after gadopentetate dimeglumine on T1-SE and FLASH (at each time t) were calculated. The CAG knees showed a mean signal...... intensity increase on early dynamic FLASH images higher by far than the CIG knees, while no significant difference was found on spin-echo images obtained 5 to 15 min after contrast injection. The early signal enhancement probably reflects the perfusion and capillary permeability of the synovium. The area...

Brain MRI Tumor Detection using Active Contour Model and Local Image Fitting Energy

Science.gov (United States)

Nabizadeh, Nooshin; John, Nigel

2014-03-01

Automatic abnormality detection in Magnetic Resonance Imaging (MRI) is an important issue in many diagnostic and therapeutic applications. Here an automatic brain tumor detection method is introduced that uses T1-weighted images and K. Zhang et. al.'s active contour model driven by local image fitting (LIF) energy. Local image fitting energy obtains the local image information, which enables the algorithm to segment images with intensity inhomogeneities. Advantage of this method is that the LIF energy functional has less computational complexity than the local binary fitting (LBF) energy functional; moreover, it maintains the sub-pixel accuracy and boundary regularization properties. In Zhang's algorithm, a new level set method based on Gaussian filtering is used to implement the variational formulation, which is not only vigorous to prevent the energy functional from being trapped into local minimum, but also effective in keeping the level set function regular. Experiments show that the proposed method achieves high accuracy brain tumor segmentation results.

The effects of exercise on cigarette cravings and brain activation in response to smoking-related images.

Science.gov (United States)

Janse Van Rensburg, Kate; Taylor, Adrian; Benattayallah, Abdelmalek; Hodgson, Tim

2012-06-01

Smokers show heightened activation toward smoking-related stimuli and experience increased cravings which can precipitate smoking cessation relapse. Exercise can be effective for modulating cigarette cravings and attenuating reactivity to smoking cues, but the mechanism by which these effects occur remains uncertain. The objective of the study was to assess the effect of exercise on regional brain activation in response to smoking-related images during temporary nicotine abstinence. In a randomised crossover design, overnight abstinent smokers (n = 20) underwent an exercise (10-min moderate-intensity stationary cycling) and passive control (seating for the same duration) treatment, following 15 h of nicotine abstinence. After each treatment, participants underwent functional magnetic resonance imaging (fMRI) brain scanning while viewing a random series of blocked smoking or neutral images. Self-reported cravings were assessed at baseline, mid-, and post-treatments. There was a significant interaction effect (treatment × time) for desire to smoke, F (2,32) = 12.5, p exercise at all time points compared with the control treatment. After both exercise and rest, significant areas of activation were found in areas of the limbic lobe and in areas associated with visual attention in response to smoking-related stimuli. Smokers showed increased activation to smoking images in areas associated with primary and secondary visual processing following rest, but not following a session of exercise. The study shows differing activation towards smoking images following exercise compared to a control treatment and may point to a neuro-cognitive process following exercise that mediates effects on cigarette cravings.

Optimal Design and Real Time Implementation of Autonomous Microgrid Including Active Load

Directory of Open Access Journals (Sweden)

Mohamed A. Hassan

2018-05-01

Full Text Available Controller gains and power-sharing parameters are the main parameters affect the dynamic performance of the microgrid. Considering an active load to the autonomous microgrid, the stability problem will be more involved. In this paper, the active load effect on microgrid dynamic stability is explored. An autonomous microgrid including three inverter-based distributed generations (DGs with an active load is modeled and the associated controllers are designed. Controller gains of the inverters and active load as well as Phase Locked Loop (PLL parameters are optimally tuned to guarantee overall system stability. A weighted objective function is proposed to minimize the error in both measured active power and DC voltage based on time-domain simulations. Different AC and DC disturbances are applied to verify and assess the effectiveness of the proposed control strategy. The results demonstrate the potential of the proposed controller to enhance the microgrid stability and to provide efficient damping characteristics. Additionally, the proposed controller is compared with the literature to demonstrate its superiority. Finally, the microgrid considered has been established and implemented on real time digital simulator (RTDS. The experimental results validate the simulation results and approve the effectiveness of the proposed controllers to enrich the stability of the considered microgrid.

Mapping whole-brain activity with cellular resolution by light-sheet microscopy and high-throughput image analysis (Conference Presentation)

Science.gov (United States)

Silvestri, Ludovico; Rudinskiy, Nikita; Paciscopi, Marco; Müllenbroich, Marie Caroline; Costantini, Irene; Sacconi, Leonardo; Frasconi, Paolo; Hyman, Bradley T.; Pavone, Francesco S.

2016-03-01

Mapping neuronal activity patterns across the whole brain with cellular resolution is a challenging task for state-of-the-art imaging methods. Indeed, despite a number of technological efforts, quantitative cellular-resolution activation maps of the whole brain have not yet been obtained. Many techniques are limited by coarse resolution or by a narrow field of view. High-throughput imaging methods, such as light sheet microscopy, can be used to image large specimens with high resolution and in reasonable times. However, the bottleneck is then moved from image acquisition to image analysis, since many TeraBytes of data have to be processed to extract meaningful information. Here, we present a full experimental pipeline to quantify neuronal activity in the entire mouse brain with cellular resolution, based on a combination of genetics, optics and computer science. We used a transgenic mouse strain (Arc-dVenus mouse) in which neurons which have been active in the last hours before brain fixation are fluorescently labelled. Samples were cleared with CLARITY and imaged with a custom-made confocal light sheet microscope. To perform an automatic localization of fluorescent cells on the large images produced, we used a novel computational approach called semantic deconvolution. The combined approach presented here allows quantifying the amount of Arc-expressing neurons throughout the whole mouse brain. When applied to cohorts of mice subject to different stimuli and/or environmental conditions, this method helps finding correlations in activity between different neuronal populations, opening the possibility to infer a sort of brain-wide 'functional connectivity' with cellular resolution.

Image understanding using sparse representations

CERN Document Server

Thiagarajan, Jayaraman J; Turaga, Pavan; Spanias, Andreas

2014-01-01

Image understanding has been playing an increasingly crucial role in several inverse problems and computer vision. Sparse models form an important component in image understanding, since they emulate the activity of neural receptors in the primary visual cortex of the human brain. Sparse methods have been utilized in several learning problems because of their ability to provide parsimonious, interpretable, and efficient models. Exploiting the sparsity of natural signals has led to advances in several application areas including image compression, denoising, inpainting, compressed sensing, blin

Wide dynamic logarithmic InGaAs sensor suitable for eye-safe active imaging

Science.gov (United States)

Ni, Yang; Bouvier, Christian; Arion, Bogdan; Noguier, Vincent

2016-05-01

In this paper, we present a simple method to analyze the injection efficiency of the photodiode interface circuit under fast shuttering conditions for active Imaging applications. This simple model has been inspired from the companion model for reactive elements largely used in CAD. In this paper, we demonstrate that traditional CTIA photodiode interface is not adequate for active imaging where fast and precise shuttering operation is necessary. Afterwards we present a direct amplification based photodiode interface which can provide an accurate and fast shuttering operation on photodiode. These considerations have been used in NIT's newly developed ROIC and corresponding SWIR sensors both in VGA 15um pitch (NSC1201) and also in QVGA 25um pitch (NSC1401).

[Effectiveness of mental health training including active listening for managers].

Science.gov (United States)

Ikegami, Kazunori; Tagawa, Yoshimasa; Mafune, Kosuke; Hiro, Hisanori; Nagata, Shoji

2008-07-01

significant increases post-training in "Job demands", "Worksite support by supervisor" and "Worksite support by co-worker", subscales of the BJSQ 12 items version. Particularly, the "Worksite support by supervisor" subscale increased significantly in 8 of the 47 sections in a comparison among sections. In this present study, we investigated the effectiveness of mental health training including Active Listening for managers, and suggest that to train Active Listening and use it at the worksite possibly strengthens "Worksite support by supervisor".

Learning of serial digits leads to frontal activation in functional MR imaging.

Science.gov (United States)

Karakaş, Hakki Muammer; Karakaş, Sirel

2006-03-01

Clinical studies have shown that performance on the serial digit learning test (SDLT) is dependent upon the mesial temporal lobes, which are responsible for learning and its consolidation. However, an effective SDLT performance is also dependent upon sequencing, temporal ordering, and the utilization of mnemonic strategies. All of these processes are among the functions of the frontal lobes; in spite of this, the relationship between SDLT performance and the frontal lobes has not been demonstrated with previously used mapping techniques. The aim of this study was to investigate the areas of the brain that are activated by SDLT performance. Ten healthy, right handed volunteers (mean age, 20.1 years; SD: 3.3) who had 12 years of education were studied with a 1.0 T MR imaging scanner. BOLD (blood oxygen level dependent) contrast and a modified SDLT were used. Activated loci were automatically mapped using a proportional grid. In learning, the most consistent activation was observed in B-a-7 of the right (80%) and the left hemispheres (50%). In recall, the most consistent activation was observed in B-a-7 of the right hemisphere (60%). Activations were observed in 2.5+/-0.97 Talairach volumes in learning, whereas they encompassed 1.7+/-0.95 volumes in recall. The difference between both phases (learning and recall) regarding total activated volume was significant (p SDLT performance was not related to learning or to recall, but to a function that is common to both of these cognitive processes. A candidate for this common factor may be the executive functions, which also include serial position processing and temporal ordering.

THE EFFECT OF SOCIAL MEDIA MARKETING ACTIVITIES ON BRAND AWARENESS, BRAND IMAGE AND BRAND LOYALTY

OpenAIRE

Yusuf BİLGİN

2018-01-01

The aim of this research is to examine the effect of social media marketing activities on brand awareness, brand image and brand loyalty. In addition, it has been aimed to analyze the effect of brand awareness and brand image on brand loyalty in this research. The population of the research consists of the consumers who actively follow five brands with the highest social score according to the Marketing Turkey social media brand performance data on social media communication channels such as ...

Magnetic resonance imaging of active sacroiliitis: Do we really need gadolinium?

Energy Technology Data Exchange (ETDEWEB)

Althoff, Christian E. [Department of Radiology, Charite - Universitaetsmedizin Berlin, Campus Mitte, Chariteplatz 1, 10117 Berlin (Germany)], E-mail: christian.althoff@charite.de; Feist, Eugen [Department of Rheumatology and Clinical Immunology, Charite - Universitaetsmedizin Berlin, Campus Mitte (Germany); Burova, Elena [Department of Radiology, Charite - Universitaetsmedizin Berlin, Campus Mitte, Chariteplatz 1, 10117 Berlin (Germany); Eshed, Iris [Department of Radiology, Chaim Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University (Israel); Bollow, Matthias [Department of Radiology, Augusta Hospital, Bochum (Germany); Hamm, Bernd; Hermann, Kay-Geert A. [Department of Radiology, Charite - Universitaetsmedizin Berlin, Campus Mitte, Chariteplatz 1, 10117 Berlin (Germany)

2009-08-15

Introduction: Magnetic resonance imaging (MRI) of active inflammatory changes of the sacroiliac joint (SIJ) in spondyloarthritis (SpA) is performed with short tau inversion recovery (STIR) sequences and fat-saturated T1-weighted fast spin-echo (FSE) sequences after administration of gadolinium-based contrast medium (T1/Gd). The aim of the present study was to compare these two pulse sequences in terms of diagnosis, diagnostic confidence, and quantification of inflammatory changes. Materials and methods: The study included 105 patients with suspected SpA; 72 patients developed clinical SpA over time. All patients were examined with STIR and T1/Gd and each of the two sequences was analyzed separately in conjunction with unenhanced T1 FSE images. For quantitative estimation of inflammatory changes, each sacroiliac joint (SIJ) was divided into 4 quadrants (and severity per quadrant was assigned a score of 0-4, resulting in a maximum sum score of 16 per SIJ). Diagnostic confidence was assessed on a visual analogue scale ranging from 0 to 10. Results: Active sacroiliitis was diagnosed in 46 patients and ruled out in 34 using STIR, whereas findings were inconclusive in 25 patients. The corresponding numbers for T1/Gd were 47, 44, and 14. Diagnostic confidence was significantly lower for STIR (7.3 {+-} 2.6) compared with T1/Gd (8.7 {+-} 1.9) (p < 0.001). The sum scores were 2.5 ({+-}3.3) for STIR and 2.2 ({+-}3.2) for T1/Gd for the right SIJ and 2.2 ({+-}2.9) (STIR) and 1.9 ({+-}3.1) (T1/Gd) for the left SIJ. Agreement was high with intraclass correlation coefficient (ICC) values of 0.86 for the right SIJ and 0.90 for the left SIJ and positive correlation (r = 0.62 right, 0.60 left). Summary: STIR sequences alone are sufficient for establishing a reliable diagnosis and quantify the amount of inflammation in active sacroiliitis. A contrast-enhanced study is dispensable in patients with established disease or in the setting of clinical follow-up studies. However, a contrast

The correlation between biological activity and diffusion-weighted MR imaging and ADC value in cases with prostate cancer.

Science.gov (United States)

Sokmen, Bedriye Koyuncu; Sokmen, Dogukan; Ucar, Nese; Ozkurt, Huseyin; Simsek, Abdulmuttalip

2017-12-31

Firstly, we aimed to investigate the correlation among dynamic contrasted magnetic resonance (MR) images, diffusion-weighted MR images, and apparent diffusion coefficent (ADC) values in patients with prostate cancer. Secondly, we aimed to investigate the roles of these variables on clinical risk classification and the biological behavior of the prostate cancer. A total of sixty with prostatic adenocarcinoma patients diagnosed between January 2011 and May 2013 were retrospectively included in the study. Risk classification of patients were evaluated as low-risk (Group 1) (n = 20) (Stage T1c-T2a, PSA T3a, PSA > 20 ng/ml, Gleason Score > 7). Diffusion-weighted MR images, dynamic contrasted MR images, and ADC values of the prostates were correlated. ADC values of the cases in Group 3 were lower than those of the other groups (p values of the areas without malignancy did not differ significantly between groups (p > 0.05). Biological activity of the tumor tissue was determined by GS, while a negative correlation was observed between GSs and ADC values of the patients, (p values were obtained. These measured values can play a role in the noninvasive determination of the cellularity of the tumoral mass.

Speckle imaging of active galactic nuclei: NGC 1068 and NGC 4151

International Nuclear Information System (INIS)

Ebstein, S.M.

1987-01-01

High-resolution images of NGC 1068 and NGC 4151 in the [O III) 5007A line the nearby continuum produced from data taken with the PAPA photon-counting imaging detector using the technique of speckle imaging are presented. The images show an unresolved core of [O III] 5007A emission in the middle of an extended emission region. The extended emission tends to lie alongside the subarcsecond radio structure. In NGC 4151, the extended emission comes from a nearly linear structure extending on both sides of the unresolved core. In NGC 1068, the extended emission is also a linear structure centered on the unresolved core but the emission is concentrated in lobes lying to either side of the major axis. The continuum of NGC 4151 is spatially unresolved. The continuum of NGC 1068 is extended ∼1'' to the SW of the center of the [O III] 5007A emission. Certain aspects of the PAPA detector are discussed, including the variable-threshold discriminators that track the image intensifier pulse height and the camera artifacts. The data processing is described in detail

of Hypoxia-Inducible Factor-1α Activity by the Fusion of High-Resolution SPECT and Morphological Imaging Tests

Directory of Open Access Journals (Sweden)

Hirofumi Fujii

2012-01-01

Full Text Available Purpose. We aimed to clearly visualize heterogeneous distribution of hypoxia-inducible factor 1α (HIF activity in tumor tissues in vivo. Methods. We synthesized of 125I-IPOS, a 125I labeled chimeric protein probe, that would visualize HIF activity. The biodistribution of 125I-IPOS in FM3A tumor-bearing mice was evaluated. Then, the intratumoral localization of this probe was observed by autoradiography, and it was compared with histopathological findings. The distribution of 125I-IPOS in tumors was imaged by a small animal SPECT/CT scanner. The obtained in vivo SPECT-CT fusion images were compared with ex vivo images of excised tumors. Fusion imaging with MRI was also examined. Results. 125I-IPOS well accumulated in FM3A tumors. The intratumoral distribution of 125I-IPOS by autoradiography was quite heterogeneous, and it partially overlapped with that of pimonidazole. High-resolution SPECT-CT fusion images successfully demonstrated the heterogeneity of 125I-IPOS distribution inside tumors. SPECT-MRI fusion images could give more detailed information about the intratumoral distribution of 125I-IPOS. Conclusion. High-resolution SPECT images successfully demonstrated heterogeneous intratumoral distribution of 125I-IPOS. SPECT-CT fusion images, more favorably SPECT-MRI fusion images, would be useful to understand the features of heterogeneous intratumoral expression of HIF activity in vivo.

A Nonparametric Shape Prior Constrained Active Contour Model for Segmentation of Coronaries in CTA Images

Directory of Open Access Journals (Sweden)

Yin Wang

2014-01-01

Full Text Available We present a nonparametric shape constrained algorithm for segmentation of coronary arteries in computed tomography images within the framework of active contours. An adaptive scale selection scheme, based on the global histogram information of the image data, is employed to determine the appropriate window size for each point on the active contour, which improves the performance of the active contour model in the low contrast local image regions. The possible leakage, which cannot be identified by using intensity features alone, is reduced through the application of the proposed shape constraint, where the shape of circular sampled intensity profile is used to evaluate the likelihood of current segmentation being considered vascular structures. Experiments on both synthetic and clinical datasets have demonstrated the efficiency and robustness of the proposed method. The results on clinical datasets have shown that the proposed approach is capable of extracting more detailed coronary vessels with subvoxel accuracy.

Cellular MR Imaging

Directory of Open Access Journals (Sweden)

Michel Modo

2005-07-01

Full Text Available Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall superparamagnetic iron oxide [(USPIO] particles or (polymeric paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (USPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune cell trafficking and of novel guided (stem cell-based therapies aimed to be translated to the clinic in the future.

Factors associated with body image dissatisfaction in Portuguese adolescents: obesity, sports activity and TV watching

Directory of Open Access Journals (Sweden)

Eduarda Maria Rocha Teles de Castro Coelho

2016-10-01

Full Text Available This cross-sectional study intended to determine the prevalence of body image dissatisfaction and associated factors in Portuguese adolescents (N=529, 10-18 years, 53.7% male and 46.3% female. The prevalence of body dissatisfaction (estimated through Collins's silhouettes was 58%. Multivariate logistic regression analyses showed that the variables associated were: obesity, watch TV over 2 hours/day and practice sport activities 4 or more days/week. In male, obesity and watch TV over 2 hours/day were related to body dissatisfaction and among female only obesity had statistical significance. It is necessary to considered different public health interventions for men and women in order to reduce this high body image dissatisfaction.   Keywords: Body image, adolescence, gender, obesity, sports activity

Imaging of Neuronal Activity in Awake Mice by Measurements of Flavoprotein Autofluorescence Corrected for Cerebral Blood Flow.

Science.gov (United States)

Takahashi, Manami; Urushihata, Takuya; Takuwa, Hiroyuki; Sakata, Kazumi; Takado, Yuhei; Shimizu, Eiji; Suhara, Tetsuya; Higuchi, Makoto; Ito, Hiroshi

2017-01-01

Green fluorescence imaging (e.g., flavoprotein autofluorescence imaging, FAI) can be used to measure neuronal activity and oxygen metabolism in living brains without expressing fluorescence proteins. It is useful for understanding the mechanism of various brain functions and their abnormalities in age-related brain diseases. However, hemoglobin in cerebral blood vessels absorbs green fluorescence, hampering accurate assessments of brain function in animal models with cerebral blood vessel dysfunctions and subsequent cerebral blood flow (CBF) alterations. In the present study, we developed a new method to correct FAI signals for hemoglobin-dependent green fluorescence reductions by simultaneous measurements of green fluorescence and intrinsic optical signals. Intrinsic optical imaging enabled evaluations of light absorption and scatters by hemoglobin, which could then be applied to corrections of green fluorescence intensities. Using this method, enhanced flavoprotein autofluorescence by sensory stimuli was successfully detected in the brains of awake mice, despite increases of CBF, and hemoglobin interference. Moreover, flavoprotein autofluorescence could be properly quantified in a resting state and during sensory stimulation by a CO 2 inhalation challenge, which modified vascular responses without overtly affecting neuronal activities. The flavoprotein autofluorescence signal data obtained here were in good agreement with the previous findings from a condition with drug-induced blockade of cerebral vasodilation, justifying the current assaying methodology. Application of this technology to studies on animal models of brain diseases with possible changes of CBF, including age-related neurological disorders, would provide better understanding of the mechanisms of neurovascular coupling in pathological circumstances.

Composite multi-lobe descriptor for cross spectral face recognition: matching active IR to visible light images

Science.gov (United States)

Cao, Zhicheng; Schmid, Natalia A.

2015-05-01

Matching facial images across electromagnetic spectrum presents a challenging problem in the field of biometrics and identity management. An example of this problem includes cross spectral matching of active infrared (IR) face images or thermal IR face images against a dataset of visible light images. This paper describes a new operator named Composite Multi-Lobe Descriptor (CMLD) for facial feature extraction in cross spectral matching of near-infrared (NIR) or short-wave infrared (SWIR) against visible light images. The new operator is inspired by the design of ordinal measures. The operator combines Gaussian-based multi-lobe kernel functions, Local Binary Pattern (LBP), generalized LBP (GLBP) and Weber Local Descriptor (WLD) and modifies them into multi-lobe functions with smoothed neighborhoods. The new operator encodes both the magnitude and phase responses of Gabor filters. The combining of LBP and WLD utilizes both the orientation and intensity information of edges. Introduction of multi-lobe functions with smoothed neighborhoods further makes the proposed operator robust against noise and poor image quality. Output templates are transformed into histograms and then compared by means of a symmetric Kullback-Leibler metric resulting in a matching score. The performance of the multi-lobe descriptor is compared with that of other operators such as LBP, Histogram of Oriented Gradients (HOG), ordinal measures, and their combinations. The experimental results show that in many cases the proposed method, CMLD, outperforms the other operators and their combinations. In addition to different infrared spectra, various standoff distances from close-up (1.5 m) to intermediate (50 m) and long (106 m) are also investigated in this paper. Performance of CMLD is evaluated for of each of the three cases of distances.

Passive and Active Fast-Neutron Imaging in Support of Advanced Fuel Cycle Initiative Safeguards Campaign

International Nuclear Information System (INIS)

Blackston, Matthew A.; Hausladen, Paul

2010-01-01

Results from safeguards-related passive and active coded-aperture fast-neutron imaging measurements of plutonium and highly enriched uranium (HEU) material configurations performed at Idaho National Laboratory s Zero Power Physics Reactor facility are presented. The imaging measurements indicate that it is feasible to use fast neutron imaging in a variety of safeguards-related tasks, such as monitoring storage, evaluating holdup deposits in situ, or identifying individual leached hulls still containing fuel. The present work also presents the first demonstration of imaging of differential die away fast neutrons.

Optimum allocation of imaging time and minimum detectable activity in dual isotope blood pool subtraction indium-111 platelet imaging

International Nuclear Information System (INIS)

Machac, J.; Horowitz, S.F.; Goldsmith, S.J.; Fuster, V.

1984-01-01

Indium-111 labeled platelet imaging is a tool for detection of thrombus formation in vascular spaces. Dual isotope blood pool subtraction may help differentiate focal platelet accumulation from blood pool activity. This study used a computer model to calculate the minimum excess-to-blood pool platelet ratio (EX/BP) and the optimum dual isotope imaging times under varied conditions of lesion size. The model simulated usual human imaging doses of 500 μCi of In-111 platelets and 5mCi of Tc-99m labeled RBCs giving a reference cardiac blood pool region (100cc) of 10000 cpm for Tc-99m and 500 cpm for In-111. The total imaging time was fixed at 20 minutes, while the two isotope imaging times (TIn/TTc) were varied, as were the simulated lesion size (cc) and EX/BP. The relative error of the excess counts was calculated using propagation of error theory. At the critical level of detection, where the excess lesion counts equal 3 times the standard deviation, the optimum TIn/TTc and minimum Ex/BP were determined for each lesion size. For the smallest lesion size (0.1cc), the minimum detectable EX/BP ratio was 1.6, with the best TIn/TTC ratio of 18/2 minutes, and for large lesions, an EX/BP of 0.1, with a TIn/TTc of 16/4. This model provides an estimate of the sensitivity and optimizes imaging times in dual isotope subtraction platelet imaging. The model is adaptable to varying isotope doses, total imaging times and lesion size. This information will be helpful in future in- vivo imaging studies of intravascular thrombi in humans

CMOS Image Sensors: Electronic Camera On A Chip

Science.gov (United States)

Fossum, E. R.

1995-01-01

Recent advancements in CMOS image sensor technology are reviewed, including both passive pixel sensors and active pixel sensors. On- chip analog to digital converters and on-chip timing and control circuits permit realization of an electronic camera-on-a-chip. Highly miniaturized imaging systems based on CMOS image sensor technology are emerging as a competitor to charge-coupled devices for low cost uses.

Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization.

Science.gov (United States)

Zhao, Chumin; Kanicki, Jerzy; Konstantinidis, Anastasios C; Patel, Tushita

2015-11-01

Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50-300 e-) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). In this study, imaging performance of a large area (29×23 cm2) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165-400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. The LFW mode shows better DQE at low air kerma (Ka<10 μGy) and should be used for DBT. At current DBT applications, air kerma (Ka∼10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165-400 μm in size can be resolved using a MGD range of 0.3-1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at MGD of 2.5 mGy), an increased CNR (by ∼10) for

Seismic Holography of Solar Activity

Science.gov (United States)

Lindsey, Charles

2000-01-01

The basic goal of the project was to extend holographic seismic imaging techniques developed under a previous NASA contract, and to incorporate phase diagnostics. Phase-sensitive imaging gives us a powerful probe of local thermal and Doppler perturbations in active region subphotospheres, allowing us to map thermal structure and flows associated with "acoustic moats" and "acoustic glories". These remarkable features were discovered during our work, by applying simple acoustic power holography to active regions. Included in the original project statement was an effort to obtain the first seismic images of active regions on the Sun's far surface.

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... Examples include but are not limited to: artificial heart valves implanted drug infusion ports artificial limbs or ... imaging based on the electrical activity of the heart, such as electrocardiography (EKG). MRI generally is not ...

Non-target activity detection by post-radioembolization yttrium-90 PET/CT: Image assessment technique and case examples

Directory of Open Access Journals (Sweden)

Yung Hsiang eKao

2014-02-01

Full Text Available High-resolution yttrium-90 (90Y imaging of post-radioembolization microsphere biodistribution may be achieved by conventional positron emission tomography with integrated computed tomography (PET/CT scanners that have time-of-flight capability. However, reconstructed 90Y PET/CT images have high background noise, making non-target activity detection technically challenging. This educational article describes our image assessment technique for non-target activity detection by 90Y PET/CT which qualitatively overcomes the problem of background noise. We present selected case examples of non-target activity in untargeted liver, stomach, gallbladder, chest wall and kidney, supported by angiography and 90Y bremsstrahlung single photon emission computed tomography with integrated computed tomography (SPECT/CT or technetium-99m macroaggregated albumin SPECT/CT.

Imaging of pancreatic tumors

International Nuclear Information System (INIS)

Brambs, Hans-Juergen; Juchems, Markus

2010-01-01

Ductal adenocarcinoma is the most frequent solid tumor of the pancreas. This tumor has distinct features including early obstruction of the pancreatic duct, diminished enhancement after administration of contrast material due to desmoplastic growth, high propensity to infiltrate adjacent structures and to metastasize into the liver and the peritoneum. Hormone active endocrine tumors cause specific clinical symptoms. Imaging is aimed at localization of these hypervascular tumors. Non hormone active tumors are most frequently malignant and demonstrate very varying features. Cystic pancreatic tumors are increasingly detected by means of cross sectional imaging. Exact classification can be achieved with knowledge of the macropathology and considering clinical presentation as well as age and gender of the patients. (orig.)

[Study on method of tracking the active cells in image sequences based on EKF-PF].

Science.gov (United States)

Tang, Chunming; Liu, Ying

2013-02-01

In cell image sequences, due to the nonlinear and nonGaussian motion characteristics of active cells, the accurate prediction and tracking is still an unsolved problem. We applied extended Kalman particle filter (EKF-PF) here in our study, attempting to solve the problem. Firstly we confirmed the existence and positions of the active cells. Then we established a motion model and improved it via adding motion angle estimation. Next we predicted motion parameters, such as displacement, velocity, accelerated velocity and motion angle, in region centers of the cells being tracked. Finally we obtained the motion traces of active cells. There were fourteen active cells in three image sequences which have been tracked. The errors were less than 2.5 pixels when the prediction values were compared with actual values. It showed that the presented algorithm may basically reach the solution of accurate predition and tracking of the active cells.

Cranial nerve clock. Part II: functional MR imaging of brain activation during a declarative memory task.

Science.gov (United States)

Weiss, K L; Welsh, R C; Eldevik, P; Bieliauskas, L A; Steinberg, B A

2001-12-01

The authors performed this study to assess brain activation during encoding and successful recall with a declarative memory paradigm that has previously been demonstrated to be effective for teaching students about the cranial nerves. Twenty-four students underwent functional magnetic resonance (MR) imaging during encoding and recall of the name, number, and function of the 12 cranial nerves. The students viewed mnemonic graphic and text slides related to individual nerves, as well as their respective control slides. For the recall paradigm, students were prompted with the numbers 1-12 (test condition) intermixed with the number 14 (control condition). Subjects were tested about their knowledge of cranial nerves outside the MR unit before and after functional MR imaging. Students learned about the cranial nerves while undergoing functional MR imaging (mean post- vs preparadigm score, 8.1 +/- 3.4 [of a possible 12] vs 0.75 +/- 0.94, bilateral prefrontal cortex, left greater than right; P brain activation. Encoding revealed statistically significant activation in the bilateral prefrontal cortex, left greater than right [corrected]; bilateral occipital and parietal associative cortices, parahippocampus region, fusiform gyri, and cerebellum. Successful recall activated the left much more than the right prefrontal, parietal associative, and anterior cingulate cortices; bilateral precuneus and cerebellum; and right more than the left posterior cingulate. A predictable pattern of brain activation at functional MR imaging accompanies the encoding and successful recall of the cranial nerves with this declarative memory paradigm.

Prostate Activated Prodrugs and Imaging Agents

National Research Council Canada - National Science Library

Jones, Graham B

2004-01-01

.... The substrate chosen was a 3 component system composed of a peptide sequence with affinity for PSA, an imaging agent and a deactivating bridge-linker, which electronically incapacitates the imaging agent...

25 CFR 170.623 - How are IRR Program projects and activities included in a self-governance agreement?

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false How are IRR Program projects and activities included in a self-governance agreement? 170.623 Section 170.623 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE... self-governance agreement? To include an IRR Program project or activity in a self-governance agreement...

Macro optical projection tomography for large scale 3D imaging of plant structures and gene activity.

Science.gov (United States)

Lee, Karen J I; Calder, Grant M; Hindle, Christopher R; Newman, Jacob L; Robinson, Simon N; Avondo, Jerome J H Y; Coen, Enrico S

2017-01-01

Optical projection tomography (OPT) is a well-established method for visualising gene activity in plants and animals. However, a limitation of conventional OPT is that the specimen upper size limit precludes its application to larger structures. To address this problem we constructed a macro version called Macro OPT (M-OPT). We apply M-OPT to 3D live imaging of gene activity in growing whole plants and to visualise structural morphology in large optically cleared plant and insect specimens up to 60 mm tall and 45 mm deep. We also show how M-OPT can be used to image gene expression domains in 3D within fixed tissue and to visualise gene activity in 3D in clones of growing young whole Arabidopsis plants. A further application of M-OPT is to visualise plant-insect interactions. Thus M-OPT provides an effective 3D imaging platform that allows the study of gene activity, internal plant structures and plant-insect interactions at a macroscopic scale. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Facebook photo activity associated with body image disturbance in adolescent girls.

Science.gov (United States)

Meier, Evelyn P; Gray, James

2014-04-01

The present study examined the relationship between body image and adolescent girls' activity on the social networking site (SNS) Facebook (FB). Research has shown that elevated Internet "appearance exposure" is positively correlated with increased body image disturbance among adolescent girls, and there is a particularly strong association with FB use. The present study sought to replicate and extend upon these findings by identifying the specific FB features that correlate with body image disturbance in adolescent girls. A total of 103 middle and high school females completed questionnaire measures of total FB use, specific FB feature use, weight dissatisfaction, drive for thinness, thin ideal internalization, appearance comparison, and self-objectification. An appearance exposure score was calculated based on subjects' use of FB photo applications relative to total FB use. Elevated appearance exposure, but not overall FB usage, was significantly correlated with weight dissatisfaction, drive for thinness, thin ideal internalization, and self-objectification. Implications for eating disorder prevention programs and best practices in researching SNSs are discussed.

MR Imaging Biomarkers to Monitor Early Response to Hypoxia-Activated Prodrug TH-302 in Pancreatic Cancer Xenografts.

Directory of Open Access Journals (Sweden)

Xiaomeng Zhang

Full Text Available TH-302 is a hypoxia-activated prodrug known to activate selectively under the hypoxic conditions commonly found in solid tumors. It is currently being evaluated in clinical trials, including two trials in Pancreatic Ductal Adenocarcinomas (PDAC. The current study was undertaken to evaluate imaging biomarkers for prediction and response monitoring of TH-302 efficacy in xenograft models of PDAC. Dynamic contrast-enhanced (DCE and diffusion weighted (DW magnetic resonance imaging (MRI were used to monitor acute effects on tumor vasculature and cellularity, respectively. Three human PDAC xenografts with known differential responses to TH-302 were imaged prior to, and at 24 h and 48 hours following a single dose of TH-302 or vehicle to determine if imaging changes presaged changes in tumor volumes. DW-MRI was performed at five b-values to generate apparent diffusion coefficient of water (ADC maps. For DCE-MRI, a standard clinically available contrast reagent, Gd-DTPA, was used to determine blood flow into the tumor region of interest. TH-302 induced a dramatic decrease in the DCE transfer constant (Ktrans within 48 hours after treatment in the sensitive tumors, Hs766t and Mia PaCa-2, whereas TH-302 had no effect on the perfusion behavior of resistant SU.86.86 tumors. Tumor cellularity, estimated from ADC, was significantly increased 24 and 48 hours after treatment in Hs766t, but was not observed in the Mia PaCa-2 and SU.86.86 groups. Notably, growth inhibition of Hs766t was observed immediately (day 3 following initiation of treatment, but was not observed in MiaPaCa-2 tumors until 8 days after initiation of treatment. Based on these preclinical findings, DCE-MRI measures of vascular perfusion dynamics and ADC measures of cell density are suggested as potential TH-302 response biomarkers in clinical trials.

MR Imaging Biomarkers to Monitor Early Response to Hypoxia-Activated Prodrug TH-302 in Pancreatic Cancer Xenografts.

Science.gov (United States)

Zhang, Xiaomeng; Wojtkowiak, Jonathan W; Martinez, Gary V; Cornnell, Heather H; Hart, Charles P; Baker, Amanda F; Gillies, Robert

2016-01-01

TH-302 is a hypoxia-activated prodrug known to activate selectively under the hypoxic conditions commonly found in solid tumors. It is currently being evaluated in clinical trials, including two trials in Pancreatic Ductal Adenocarcinomas (PDAC). The current study was undertaken to evaluate imaging biomarkers for prediction and response monitoring of TH-302 efficacy in xenograft models of PDAC. Dynamic contrast-enhanced (DCE) and diffusion weighted (DW) magnetic resonance imaging (MRI) were used to monitor acute effects on tumor vasculature and cellularity, respectively. Three human PDAC xenografts with known differential responses to TH-302 were imaged prior to, and at 24 h and 48 hours following a single dose of TH-302 or vehicle to determine if imaging changes presaged changes in tumor volumes. DW-MRI was performed at five b-values to generate apparent diffusion coefficient of water (ADC) maps. For DCE-MRI, a standard clinically available contrast reagent, Gd-DTPA, was used to determine blood flow into the tumor region of interest. TH-302 induced a dramatic decrease in the DCE transfer constant (Ktrans) within 48 hours after treatment in the sensitive tumors, Hs766t and Mia PaCa-2, whereas TH-302 had no effect on the perfusion behavior of resistant SU.86.86 tumors. Tumor cellularity, estimated from ADC, was significantly increased 24 and 48 hours after treatment in Hs766t, but was not observed in the Mia PaCa-2 and SU.86.86 groups. Notably, growth inhibition of Hs766t was observed immediately (day 3) following initiation of treatment, but was not observed in MiaPaCa-2 tumors until 8 days after initiation of treatment. Based on these preclinical findings, DCE-MRI measures of vascular perfusion dynamics and ADC measures of cell density are suggested as potential TH-302 response biomarkers in clinical trials.

Imaging of glia activation in people with primary lateral sclerosis

Directory of Open Access Journals (Sweden)

Sabrina Paganoni

2018-01-01

Conclusions: This study supports a link between glia activation and neuronal degeneration in PLS, and suggests that these disease mechanisms can be measured in vivo in PLS. Future studies are needed to determine the longitudinal changes of these imaging measures and to clarify if MR-PET with [11C]-PBR28 can be used as a biomarker for drug development in the context of clinical trials for PLS.

PET imaging in pediatric oncology

International Nuclear Information System (INIS)

Shulkin, B.L.

2004-01-01

High-quality PET imaging of pediatric patients is challenging and requires attention to issues commonly encountered in the practice of pediatric nuclear medicine, but uncommon to the imaging of adult patients. These include intravenous access, fasting, sedation, consent, and clearance of activity from the urinary tract. This paper discusses some technical differences involved in pediatric PET to enhance the quality of scans and assure the safety and comfort of pediatric patients. (orig.)

Active and Passive Optical Imaging Modality for Unobtrusive Cardiorespiratory Monitoring and Facial Expression Assessment.

Science.gov (United States)

Blazek, Vladimir; Blanik, Nikolai; Blazek, Claudia R; Paul, Michael; Pereira, Carina; Koeny, Marcus; Venema, Boudewijn; Leonhardt, Steffen

2017-01-01

Because of their obvious advantages, active and passive optoelectronic sensor concepts are being investigated by biomedical research groups worldwide, particularly their camera-based variants. Such methods work noninvasively and contactless, and they provide spatially resolved parameter detection. We present 2 techniques: the active photoplethysmography imaging (PPGI) method for detecting dermal blood perfusion dynamics and the passive infrared thermography imaging (IRTI) method for detecting skin temperature distribution. PPGI is an enhancement of classical pulse oximetry. Approved algorithms from pulse oximetry for the detection of heart rate, heart rate variability, blood pressure-dependent pulse wave velocity, pulse waveform-related stress/pain indicators, respiration rate, respiratory variability, and vasomotional activity can easily be adapted to PPGI. Although the IRTI method primarily records temperature distribution of the observed object, information on respiration rate and respiratory variability can also be derived by analyzing temperature change over time, for example, in the nasal region, or through respiratory movement. Combined with current research areas and novel biomedical engineering applications (eg, telemedicine, tele-emergency, and telemedical diagnostics), PPGI and IRTI may offer new data for diagnostic purposes, including assessment of peripheral arterial and venous oxygen saturation (as well as their differences). Moreover, facial expressions and stress and/or pain-related variables can be derived, for example, during anesthesia, in the recovery room/intensive care unit and during daily activities. The main advantages of both monitoring methods are unobtrusive data acquisition and the possibility to assess vital variables for different body regions. These methods supplement each other to enable long-term monitoring of physiological effects and of effects with special local characteristics. They also offer diagnostic advantages for

Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

Energy Technology Data Exchange (ETDEWEB)

Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke [Nihon Univ., Tokyo (Japan). School of Medicine

2000-12-01

Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5{+-}6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33{+-}0.22 in chronic heart failure class I, 2.50{+-}0.34 in class II, 1.95{+-}0.61 in class III, and 1.39{+-}0.29 in class IV (p<0.05). %WR was 24.8{+-}12.8% in chronic heart failure class I, 23.3{+-}10.2% in class II, 49.2{+-}24.5% in class III, and 66.3{+-}26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

Ex Vivo Activity of Endoperoxide Antimalarials, Including Artemisone and Arterolane, against Multidrug-Resistant Plasmodium falciparum Isolates from Cambodia

Science.gov (United States)

2014-10-01

OCT 2014 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Ex Vivo Activity of Endoperoxide Antimalarials , Including Artemisone...Prescribed by ANSI Std Z39-18 Ex Vivo Activity of Endoperoxide Antimalarials , Including Artemisone and Arterolane, against Multidrug-Resistant...potent antimalarial activity (2, 3). Despite having a rapid mecha- nism of action, artemisinin resistance eventually emerged and was first detected

Functional magnetic resonance imaging in the activation of working memory

International Nuclear Information System (INIS)

Spitzer, M.; Kammer, T.; Bellemann, M.E.; Gueckel, F.; Georgi, M.; Gass, A.; Brix, G.

1996-01-01

Functional magnetic resonance imaging was used in conjunction with a letter detection task for the study of working memory in 16 normal subjects. Because of movement artifacts, data from only 9 subjects were analysed. In the activation taks, subjects responded by pressing a button whenever any presented letter was the same as the second last in the sequence. In the control condition, the subjects had to respond to a fixed letter. Hence, the activation condition and the control condition differend only subjectively, i.e., regarding the task demand, whereas the stimuli and the type and frequency of response were identical. The activation condition produced significant activation in the dorsolateral prefrontal cortex (Brodmann's areas 10, 46, and 9). In contrast to experimental tasks previsouly used rather extensively to study the prefrontal cortex, the present paradigm is characterized by its simplicity, interpretability, and its ties to known neurophysiology of the frontal cortex. (orig.) [de

Framework for a low-cost intra-operative image-guided neuronavigator including brain shift compensation

OpenAIRE

Bucki, Marek; Lobos, Claudio; Payan, Yohan

2007-01-01

In this paper we present a methodology to address the problem of brain tissue deformation referred to as 'brain-shift'. This deformation occurs throughout a neurosurgery intervention and strongly alters the accuracy of the neuronavigation systems used to date in clinical routine which rely solely on pre-operative patient imaging to locate the surgical target, such as a tumour or a functional area. After a general description of the framework of our intra-operative image-guided system, we desc...

Image-guided recording system for spatial and temporal mapping of neuronal activities in brain slice.

Science.gov (United States)

Choi, Geonho; Lee, Jeonghyeon; Kim, Hyeongeun; Jang, Jaemyung; Im, Changkyun; Jeon, Nooli; Jung, Woonggyu

2018-03-01

In this study, we introduce the novel image-guided recording system (IGRS) for efficient interpretation of neuronal activities in the brain slice. IGRS is designed to combine microelectrode array (MEA) and optical coherence tomography at the customized upright microscope. It allows to record multi-site neuronal signals and image of the volumetric brain anatomy in a single body configuration. For convenient interconnection between a brain image and neuronal signals, we developed the automatic mapping protocol that enables us to project acquired neuronal signals on a brain image. To evaluate the performance of IGRS, hippocampal signals of the brain slice were monitored, and corresponding with two-dimensional neuronal maps were successfully reconstructed. Our results indicated that IGRS and mapping protocol can provide the intuitive information regarding long-term and multi-sites neuronal signals. In particular, the temporal and spatial mapping capability of neuronal signals would be a very promising tool to observe and analyze the massive neuronal activity and connectivity in MEA-based electrophysiological studies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The first X-ray imaging spectroscopy of quiescent solar active regions with NuSTAR

DEFF Research Database (Denmark)

Hannah, Iain G.; Grefenstette, Brian W.; Smith, David M.

2016-01-01

We present the first observations of quiescent active regions (ARs) using the Nuclear Spectroscopic Telescope Array (NuSTAR), a focusing hard X-ray telescope capable of studying faint solar emission from high-temperature and non-thermal sources. We analyze the first directly imaged and spectrally...... resolved X-rays above 2 keV from non-flaring ARs, observed near the west limb on 2014 November 1. The NuSTAR X-ray images match bright features seen in extreme ultraviolet and soft X-rays. The NuSTAR imaging spectroscopy is consistent with isothermal emission of temperatures 3.1-4.4 MK and emission...

The correlation between biological activity and diffusion-weighted MR imaging and ADC value in cases with prostate cancer

Directory of Open Access Journals (Sweden)

Bedriye Koyuncu Sokmen

2017-12-01

Full Text Available Purpose: Firstly, we aimed to investigate the correlation among dynamic contrasted magnetic resonance (MR images, diffusion-weighted MR images, and apparent diffusion coefficent (ADC values in patients with prostate cancer. Secondly, we aimed to investigate the roles of these variables on clinical risk classification and the biological behavior of the prostate cancer. Methods: A total of sixty with prostatic adenocarcinoma patients diagnosed between January 2011 and May 2013 were retrospectively included in the study. Risk classification of patients were evaluated as low-risk (Group 1 (n = 20 (Stage T1c-T2a, PSA T3a, PSA > 20 ng/ml, Gleason Score > 7. Diffusion-weighted MR images, dynamic contrasted MR images, and ADC values of the prostates were correlated. Results: ADC values of the cases in Group 3 were lower than those of the other groups (p 0.05. Biological activity of the tumor tissue was determined by GS, while a negative correlation was observed between GSs and ADC values of the patients, (p < 0.001. Conclusion: In tumors with higher Gleason scores, lower ADC values were obtained. These measured values can play a role in the noninvasive determination of the cellularity of the tumoral mass.

Significance of magnetic resonance imaging for early rheumatoid arthritis activity

Directory of Open Access Journals (Sweden)

E Y Pogozeva

2009-01-01

Full Text Available Objective. To assess possibility of magnetic resonance image (MRI application for rheu- matoid arthritis (RA activity and severity assessment.Material and methods. 100 pts with RA who fulfilled the 1987 ACR criteria with disease duration less than 12 months were included. Standard clinical examination with evaluation of tender and swollen joint counts, acute phase markers, hand and foot X-ray and hand MRI with 0,2 T Artoscan apparatus (ESAOTE Biomedica, Italy were performed.Results. MRI showed hand joint synovitis in 94,5%, erosions – in 67,3% of cases. X-ray examination revealed erosions in only 20,8% of pts. Localization of erosions revealed by X-ray and MRI coincided in 36,4% of cases and in 61,8% of pts erosions were detected only by MRI. MRI confirmed clinical conclusion about presence or absence of metacarpophalangeal and wrist joint synovitis in 64,5% and 74,5% of cases respectively. In8,2% and 21,8% MRI revealed signs of synovitis in clinically intact joints. MRI synovitis score correlated with clinical and laboratory measures of disease activity – DAS 28 (r=0,37, p=0,001, CRP(r=0,30, p=0,001, ESR (r=0,42, p=0,001, HAQ (r=0,24, p=0,001. Weak correlation was revealed between ESR and presence of erosions (r=0,29, CRP, ESR and MRI signs of bone marrow edema (r=0,27, p=0,005 and r=0,29, p=0,002 respectively. Relationship between laboratory and clinical features was weaker and referred only to CRP level and swollen joint count (p=0,05.Conclusion. MRI signs may be used as additional and independent measures of inflammatory activity (particularly synovitis score and severity of RA

Hypoperfusion in baseline and cognitively activated brain SPECT imaging of adult and elderly patients with depression

International Nuclear Information System (INIS)

Zhao Jinhua; Lin Xiangtong; Jiang Kaida; Ang Qiuqing; Shi Shenxun; Xue Fangping

2000-01-01

Objective: To evaluate the rCBF abnormalities of the baseline and cognitively activated rCBF imaging in unmedicated adult and elderly patients with depression. Methods: The subjects were divided into four groups: depressed adults, normal adult controls, depressed elders and normal elderly controls. All depressed patients were unmedicated and the diagnoses (depression of moderate degree with accompanying somatization) were confirmed by the ICD-10 criteria. Age range of the 39 depressed adult patients was 17 - 55 years. 17 age-matched normal adult controls (age range 21 - 50 years) were studied under identical conditions. The age range of 18 depressed elderly patients was 62 - 76 years. 21 age-matched normal elderly controls (age range 60 - 72 years) were studied under identical conditions. Baseline and cognitively activated 99 Tc m -ECD SPECT were performed on 25 of the 39 adult patients with depression and 17 normal adult controls. Baseline 99 Tc m -ECD SPECT only was performed on the remaining 14 patients with depression. Baseline and cognitively activated 99 Tc m -ECD SPECT were performed on 12 of the 18 elderly patients with depression and 18 of the 21 normal elderly controls. Baseline 99 Tc m -ECD SPECT only was performed on the remaining elderly patients and 3 normal elderly controls. Results: 1) The characteristic abnormalities of baseline and cognitively activated brain SPECT imaging of depression in adults: the baseline rCBF values of frontal and temporal lobe decreased significantly and the activated rCBF values of frontal, temporal lobe decreased more evidently than that in the baseline imaging and additionally decreased activated rCBF values in parietal lobe were found. 2) The characteristic abnormalities of baseline and cognitively activated brain SPECT imaging of elderly patients with depression: the baseline rCBF values of frontal, temporal lobe and right basal ganglia decreased significantly and the activated rCBF values of frontal, temporal, right

Imaging of Neuronal Activity in Awake Mice by Measurements of Flavoprotein Autofluorescence Corrected for Cerebral Blood Flow

Directory of Open Access Journals (Sweden)

Manami Takahashi

2018-01-01

Full Text Available Green fluorescence imaging (e.g., flavoprotein autofluorescence imaging, FAI can be used to measure neuronal activity and oxygen metabolism in living brains without expressing fluorescence proteins. It is useful for understanding the mechanism of various brain functions and their abnormalities in age-related brain diseases. However, hemoglobin in cerebral blood vessels absorbs green fluorescence, hampering accurate assessments of brain function in animal models with cerebral blood vessel dysfunctions and subsequent cerebral blood flow (CBF alterations. In the present study, we developed a new method to correct FAI signals for hemoglobin-dependent green fluorescence reductions by simultaneous measurements of green fluorescence and intrinsic optical signals. Intrinsic optical imaging enabled evaluations of light absorption and scatters by hemoglobin, which could then be applied to corrections of green fluorescence intensities. Using this method, enhanced flavoprotein autofluorescence by sensory stimuli was successfully detected in the brains of awake mice, despite increases of CBF, and hemoglobin interference. Moreover, flavoprotein autofluorescence could be properly quantified in a resting state and during sensory stimulation by a CO2 inhalation challenge, which modified vascular responses without overtly affecting neuronal activities. The flavoprotein autofluorescence signal data obtained here were in good agreement with the previous findings from a condition with drug-induced blockade of cerebral vasodilation, justifying the current assaying methodology. Application of this technology to studies on animal models of brain diseases with possible changes of CBF, including age-related neurological disorders, would provide better understanding of the mechanisms of neurovascular coupling in pathological circumstances.

Body Image and Nutritional Status Are Associated with Physical Activity in Men and Women: The ELSA-Brasil Study

OpenAIRE

Coelho, Carolina G.; Giatti, Luana; Molina, Maria D. C. B.; Nunes, Maria A. A.; Barreto, Sandhi M.

2015-01-01

The association of body image dissatisfaction and obesity with physical activity is likely to differ according to gender. To investigate this hypothesis, we conducted a cross-sectional study among the ELSA-Brasil cohort members aged 34–65 years (n = 13,286). The body image dissatisfaction was present even among normal weight individuals of both sexes and was associated with lesser chances of practicing moderate physical activity in women and intense physical activity in men. Men and women w...

Management of formation of image of Lithuanian countryside

OpenAIRE

Atkočiūnienė, Vilma; Boculo, Irina

2011-01-01

Image formation of country­side is part of a regional image itself; it includes all general country­side development areas. Image formation of country­side is based on the efforts made by different concerned actors and their additional initiative; consequently, the core activity of the above process is management. The investigation is aimed at the analysis of theoretical constituent actors assign ed to the process of development of country­side, at the identification of country­side image ele...

Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization

Energy Technology Data Exchange (ETDEWEB)

Zhao, Chumin; Kanicki, Jerzy, E-mail: kanicki@eecs.umich.edu [Solid-State Electronics Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Konstantinidis, Anastasios C. [Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom and Diagnostic Radiology and Radiation Protection, Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX (United Kingdom); Patel, Tushita [Department of Physics, University of Virginia, Charlottesville, Virginia 22908 (United States)

2015-11-15

Purpose: Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50–300 e{sup −}) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). Methods: In this study, imaging performance of a large area (29 × 23 cm{sup 2}) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165–400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. Results: The LFW mode shows better DQE at low air kerma (K{sub a} < 10 μGy) and should be used for DBT. At current DBT applications, air kerma (K{sub a} ∼ 10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165–400 μm in size can be resolved using a MGD range of 0.3–1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at

Large area CMOS active pixel sensor x-ray imager for digital breast tomosynthesis: Analysis, modeling, and characterization

International Nuclear Information System (INIS)

Zhao, Chumin; Kanicki, Jerzy; Konstantinidis, Anastasios C.; Patel, Tushita

2015-01-01

Purpose: Large area x-ray imagers based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been proposed for various medical imaging applications including digital breast tomosynthesis (DBT). The low electronic noise (50–300 e − ) of CMOS APS x-ray imagers provides a possible route to shrink the pixel pitch to smaller than 75 μm for microcalcification detection and possible reduction of the DBT mean glandular dose (MGD). Methods: In this study, imaging performance of a large area (29 × 23 cm 2 ) CMOS APS x-ray imager [Dexela 2923 MAM (PerkinElmer, London)] with a pixel pitch of 75 μm was characterized and modeled. The authors developed a cascaded system model for CMOS APS x-ray imagers using both a broadband x-ray radiation and monochromatic synchrotron radiation. The experimental data including modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE) were theoretically described using the proposed cascaded system model with satisfactory consistency to experimental results. Both high full well and low full well (LFW) modes of the Dexela 2923 MAM CMOS APS x-ray imager were characterized and modeled. The cascaded system analysis results were further used to extract the contrast-to-noise ratio (CNR) for microcalcifications with sizes of 165–400 μm at various MGDs. The impact of electronic noise on CNR was also evaluated. Results: The LFW mode shows better DQE at low air kerma (K a < 10 μGy) and should be used for DBT. At current DBT applications, air kerma (K a ∼ 10 μGy, broadband radiation of 28 kVp), DQE of more than 0.7 and ∼0.3 was achieved using the LFW mode at spatial frequency of 0.5 line pairs per millimeter (lp/mm) and Nyquist frequency ∼6.7 lp/mm, respectively. It is shown that microcalcifications of 165–400 μm in size can be resolved using a MGD range of 0.3–1 mGy, respectively. In comparison to a General Electric GEN2 prototype DBT system (at MGD of 2.5 m

Scoring inflammatory activity of the spine by magnetic resonance imaging in ankylosing spondylitis: a multireader experiment

DEFF Research Database (Denmark)

Lukas, C; Braun, J; van der Heijde, D

2007-01-01

OBJECTIVE: Magnetic resonance imaging (MRI) of the spine is increasingly important in the assessment of inflammatory activity in clinical trials with patients with ankylosing spondylitis (AS). We investigated feasibility, inter-reader reliability, sensitivity to change, and discriminatory ability...... of 3 different scoring methods for MRI activity and change in activity of the spine in patients with AS. METHODS: Thirty sets of spinal MRI at baseline and after 24 weeks of followup, derived from a randomized clinical trial comparing a tumor necrosis factor (TNF)-blocking drug (n = 20) with placebo (n...... the Ankylosing Spondylitis spine Magnetic Resonance Imaging-activity [ASspiMRI-a, grading activity (0-6) per vertebral unit in 23 units]; the Berlin modification of the ASspiMRI-a; and the Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system, which scores the 6 vertebral units considered...

Image Cytometric Analysis of Algal Spores for Evaluation of Antifouling Activities of Biocidal Agents.

Science.gov (United States)

Il Koo, Bon; Lee, Yun-Soo; Seo, Mintae; Seok Choi, Hyung; Leng Seah, Geok; Nam, Taegu; Nam, Yoon Sung

2017-07-31

Chemical biocides have been widely used as marine antifouling agents, but their environmental toxicity impose regulatory restriction on their use. Although various surrogate antifouling biocides have been introduced, their comparative effectiveness has not been well investigated partly due to the difficulty of quantitative evaluation of their antifouling activity. Here we report an image cytometric method to quantitatively analyze the antifouling activities of seven commercial biocides using Ulva prolifera as a target organism, which is known to be a dominant marine species causing soft fouling. The number of spores settled on a substrate is determined through image analysis using the intrinsic fluorescence of chlorophylls in the spores. Pre-determined sets of size and shape of spores allow for the precise determination of the number of settled spores. The effects of biocide concentration and combination of different biocides on the spore settlement are examined. No significant morphological changes of Ulva spores are observed, but the amount of adhesive pad materials is appreciably decreased in the presence of biocides. It is revealed that the growth rate of Ulva is not directly correlated with the antifouling activities against the settlement of Ulva spores. This work suggests that image cytometric analysis is a very convenient, fast-processable method to directly analyze the antifouling effects of biocides and coating materials.

Brazil: Overview of activities on Neutron Imaging (NI) and Cultural Heritage (CH) studies

International Nuclear Information System (INIS)

Pugliesi, Reynaldo

2012-01-01

The neutron imaging is a set of non - destructive testing techniques commonly employed to inspect the internal structure of objects. Because of the neutron - matter interaction characteristics, these techniques are largely employed to inspect hydrogenous substances (water, organic fibers, adhesives, etc) even wrapped by thick metal layers. The Brazilian culture is surrounded by a rich cultural heritage, mainly left by Indians and slaves. Many of the old objects and tools they have used, were manufactured by using clay, wood, organic fibers as well as bones. These materials and the ones used for their restoration are manufactured of several types of hydrogenous substances and hence the use of neutron imaging techniques are very adequate to study such objects. The neutron imaging activities at IPEN - CNEN/SP began in 1988 and the primary objective of the working group was to design and to construct an operational facility for neutron imaging, to be installed in the beam-hole - 08 of the 5MW IEA-R1 Nuclear Research Reactor. From 1992 to 1997, the group has developed several 2D imaging techniques

Autonomic markers of emotional processing: skin sympathetic nerve activity in humans during exposure to emotionally charged images.

Science.gov (United States)

Brown, Rachael; James, Cheree; Henderson, Luke A; Macefield, Vaughan G

2012-01-01

The sympathetic innervation of the skin primarily subserves thermoregulation, but the system has also been commandeered as a means of expressing emotion. While it is known that the level of skin sympathetic nerve activity (SSNA) is affected by anxiety, the majority of emotional studies have utilized the galvanic skin response as a means of inferring increases in SSNA. The purpose of the present study was to characterize the changes in SSNA when showing subjects neutral or emotionally charged images from the International Affective Picture System (IAPS). SSNA was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in ten subjects. Neutral images, positively charged images (erotica) or negatively charged images (mutilation) were presented in blocks of fifteen images of a specific type, each block lasting 2 min. Images of erotica or mutilation were presented in a quasi-random fashion, each block following a block of neutral images. Both images of erotica or images of mutilation caused significant increases in SSNA, but the increases in SSNA were greater for mutilation. The increases in SSNA were often coupled with sweat release and cutaneous vasoconstriction; however, these markers were not always consistent with the SSNA increases. We conclude that SSNA, comprising cutaneous vasoconstrictor and sudomotor activity, increases with both positively charged and negatively charged emotional images. Measurement of SSNA provides a more comprehensive assessment of sympathetic outflow to the skin than does the use of sweat release alone as a marker of emotional processing.

In Vivo Molecular Imaging of Cathepsin and Matrix Metalloproteinase Activity Discriminates between Arthritic and Osteoarthritic Processes in Mice

Directory of Open Access Journals (Sweden)

Eline A. Vermeij

2014-01-01

Full Text Available Rheumatoid arthritis (RA and osteoarthritis (OA are serologically and clinically distinctive, but at the local level, both diseases have many molecular pathways in common. In vivo molecular imaging can unravel the local pathologic processes involved in both diseases. In this study, we investigated matrix metalloproteinase (MMP and cathepsin activity during cartilage destruction, in an RA and an OA mouse model, using biophotonic imaging of substrate-based probes. Mice with collagen-induced arthritis (CIA or destabilization of the medial meniscus (DMM were imaged using near-infrared fluorescent probes, activated by several cathepsins or MMPs. Fluorescence signal intensity was compared to synovial gene expression, histology, and cartilage staining of a neoepitope of aggrecan cleaved by MMPs with the amino acids DIPEN. Increased cathepsin and MMP activity was seen during CIA, whereas the DMM model only showed increased MMP activity. DIPEN expression was seen only during CIA. A possible explanation can be differences in gene expressions; MMP3 and -13, known to produce DIPEN neoepitopes, were upregulated in the CIA model, whereas MMP12, known to be involved in elastin degradation and chemokine inhibition, was upregulated in the DMM model. Thus, molecular imaging showed no cathepsin activity at the time of cartilage damage in the DMM model, whereas both cathepsins and MMPs are active in the CIA model during disease progression.

Applications of image processing and visualization in the evaluation of murder and assault

Science.gov (United States)

Oliver, William R.; Rosenman, Julian G.; Boxwala, Aziz; Stotts, David; Smith, John; Soltys, Mitchell; Symon, James; Cullip, Tim; Wagner, Glenn

1994-09-01

Recent advances in image processing and visualization are of increasing use in the investigation of violent crime. The Digital Image Processing Laboratory at the Armed Forces Institute of Pathology in collaboration with groups at the University of North Carolina at Chapel Hill are actively exploring visualization applications including image processing of trauma images, 3D visualization, forensic database management and telemedicine. Examples of recent applications are presented. Future directions of effort include interactive consultation and image manipulation tools for forensic data exploration.

Long-term 4D Geoelectrical Imaging of Moisture Dynamics in an Active Landslide

Science.gov (United States)

Uhlemann, S.; Chambers, J. E.; Wilkinson, P. B.; Maurer, H.; Meldrum, P.; Gunn, D.; Smith, A.; Dijkstra, T.

2016-12-01

Landslides are a major natural hazard, endangering communities and infrastructure worldwide. Mitigating landslide risk relies on understanding causes and triggering processes, which are often linked to moisture dynamics in slopes causing material softening and elevated pore water pressures. Geoelectrical monitoring is frequently applied to study landslide hydrology. However, its sensitivity to sensor movements has been a challenge for long-term studies on actively failing slopes. Although 2D data acquisition has previously been favoured, it provides limited resolution and relatively poor representation of important 3D landslide structures. We present a novel methodology to incorporate electrode movements into a time-lapse 3D inversion workflow, resulting in a virtually artefact-free time-series of resistivity models. Using temperature correction and laboratory hydro-geophysical relationships, resistivity models are translated into models of moisture content. The data span more than three years, enabling imaging of processes pre- and post landslide reactivation. In the two years before reactivation, the models showed surficial wetting and drying, drainage pathways, and deeper groundwater dynamics. During reactivation, exceptionally high moisture contents were imaged throughout the slope, which was confirmed by independent measurements. Preferential flow was imaged that stabilized parts of the landslide by diverting moisture, and thus dissipating pore pressures, from the slip surface. The results highlight that moisture levels obtained from resistivity monitoring may provide a better activity threshold than rainfall intensity. Based on this work, pro-active remediation measures could be designed and effective early-warning systems implemented. Eventually, resistivity monitoring that can account for moving electrodes may provide a new means for pro-active mitigation of landslide risk, especially for communities and critical infrastructure.

A preliminary report on the use of functional magnetic resonance imaging with simultaneous urodynamics to record brain activity during micturition.

Science.gov (United States)

Krhut, Jan; Tintera, Jaroslav; Holý, Petr; Zachoval, Roman; Zvara, Peter

2012-08-01

We mapped brain activity during micturition using functional magnetic resonance imaging with simultaneous recording of urodynamic properties during slow bladder filling and micturition. We evaluated 12 healthy female volunteers 20 to 68 years old. Eight subjects could urinate while supine. Meaningful data were obtained on 6 of these subjects. Brain activity was recorded continuously during bladder filling and micturition. Functional magnetic resonance imaging measurements made during the micturition phase were used for the final analysis. Using group statistics we identified clusters of brain activity in the parahippocampal gyrus, anterior cingulate gyrus, inferior temporal gyrus and inferior frontal gyrus during micturition. At the individual level we also observed activation in the upper pontine region, thalamus and posterior cingulum. In subjects unable to void brain activation was documented in the frontal lobe and posterior cingulate gyrus but not in the pons, thalamus or anterior cingulate gyrus. In 5 subjects we identified a relevant pattern of brain activity during the terminal portion of the filling phase when the patient reported a strong desire to urinate. This new protocol allows for the localization of brain structures that are active during micturition. Data suggest that additional validation studies are needed. Future studies will test modifications that include more detailed monitoring of bladder sensation, stratifying subjects based on age and gender, and increasing the number of data points by adding subjects and the number of micturitions recorded in a single subject. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Early dynamic imaging in 68Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions.

Science.gov (United States)

Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Fritz, Josef; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; von Guggenberg, Elisabeth; Bektic, Jasmin; Horninger, Wolfgang; Virgolini, Irene Johanna

2017-05-01

PET/CT with 68 Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic 68 Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to 68 Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV max of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic 68 Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv max was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p dynamic imaging in 68 Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic bladder accumulation. Performance of early dynamic imaging in addition to whole body imaging 60 min after tracer injection might improve the detection rate

Exploring the potential of using stories about diverse scientists and reflective activities to enrich primary students' images of scientists and scientific work

Science.gov (United States)

Sharkawy, Azza

2012-06-01

The purpose of this qualitative study was to explore the potential of using stories about diverse scientists to broaden primary students' images of scientists and scientific work. Stories featuring scientists from diverse socio-cultural backgrounds (i.e., physical ability, gender, ethnicity) were presented to 11 grade one students over a 15 -week period. My analysis of pre-and post audio-taped interview transcripts, draw-a-scientist-tests (Chambers 1983), participant observations and student work suggest that the stories about scientists and follow-up reflective activities provided resources for students that helped them: (a) acquire images of scientists from less dominant socio-cultural backgrounds; (b) enrich their views of scientific work from predominantly hands-on/activity-oriented views to ones that includes cognitive and positive affective dimensions. One of the limitations of using stories as a tool to extend students' thinking about science is highlighted in a case study of a student who expresses resistance to some of the counter-stereotypic images presented in the stories. I also present two additional case studies that illustrate how shifts in student' views of the nature of scientific work can change their interest in future participation in scientific work.

In Vivo Imaging of Retinoic Acid Receptor Activity using a Sodium/Iodide Symporter and Luciferase Dual Imaging Reporter Gene

Directory of Open Access Journals (Sweden)

Min Kyung So

2004-07-01

Full Text Available Retinoic acids are natural derivatives of vitamin A, and play important roles in modulating tumor cell growth by regulating differentiation, thus suggesting the potential use of these derivatives in cancer therapy and prevention. To visualize the intranuclear responses of functional retinoic acid receptors, we have developed a dual-imaging reporter gene system based on the use of sodium/iodide symporter (NIS and luciferase in cancer cell lines. NIS and luciferase genes were linked with an internal ribosome entry site, and placed under the control of an artificial cis-acting retinoic acid responsive element (pRARE/NL. After retinoic acid treatment, I-125 uptake by pRARE/NL transfected cells was found to have increased by up to about five times that of nontreated cells. The bioluminescence intensity of pRARE/NL transfected cells showed dose-dependency. In vivo luciferase images showed higher intensity in retinoic acid treated SK-RARE/NL tumors, and scintigraphic images of SK-RARE/NL tumors showed increased Tc-99m uptake after retinoic acid treatment. The NIS/luciferase imaging reporter system was sufficiently sensitive to allow the visualization of intranuclear retinoic acid receptor activity. This cis-enhancer imaging reporter system may be useful in vitro and in vivo for the evaluation of retinoic acid responses in such areas as cellular differentiation and chemoprevention.

Visual activation in infants and young children studied by functional magnetic resonance imaging

DEFF Research Database (Denmark)

Born, Alfred Peter; Leth, H; Miranda Gimenez-Ricco, Maria Jo

1998-01-01

The purpose of this study was to determine whether visual stimulation in sleeping infants and young children can be examined by functional magnetic resonance imaging. We studied 17 children, aged 3 d to 48 mo, and three healthy adults. Visual stimulation was performed with 8-Hz flickering light...... through the sleeping childs' closed eyelids. Functional magnetic resonance imaging was performed with a gradient echoplanar sequence in a l.5-T magnetic resonance scanner. Six subjects were excluded because of movement artifacts; the youngest infant showed no response. In 10 children, we could demonstrate...... flow during activation. The different response patterns in young children and adults can reflect developmental or behavioral differences. Localization of the activation seemed to be age-dependent. In the older children and the adults, it encompassed the whole length of the calcarine sulcus, whereas...

Image-based synchronization of force and bead motion in active electromagnetic microrheometry

International Nuclear Information System (INIS)

Park, Chang-Young; Saleh, Omar A

2014-01-01

In the past, electromagnetic tweezers have been used to make active microrheometers. An active microrheometer measures the dynamic mechanical properties of a material from the motion of embedded particles under external force, e.g. a sinusoidal magnetic force generated by a sinusoidal current on a coil. The oscillating amplitude and the phase lag of the motion are then used to estimate the material’s dynamic mechanical properties. The phase lag, in particular, requires precise synchronization of the particle motion with the external force. In previous works, synchronization difficulties have arisen from measuring two parameters with two instruments, one of them being a camera. We solved the synchronization issue by measuring two parameters with a single instrument, the camera alone. From captured images, particles can be tracked in three dimensions through an image-analysis algorithm while the current on the coil can be measured from the brightness of the image; this enables simultaneous synchronization of the phases of the driving current on the electromagnet coil and the motion of the magnetic probe particle. We calibrate the phase delay between the magnetic force and the particle’s motion in glycerol and confirm the calibration with a Hall probe. The technique is further tested by measuring the shear modulus of a polyacrylamide gel, and comparing the results to those obtained using a conventional rheometer. (paper)

Active Sensor for Microwave Tissue Imaging with Bias-Switched Arrays.

Science.gov (United States)

Foroutan, Farzad; Nikolova, Natalia K

2018-05-06

A prototype of a bias-switched active sensor was developed and measured to establish the achievable dynamic range in a new generation of active arrays for microwave tissue imaging. The sensor integrates a printed slot antenna, a low-noise amplifier (LNA) and an active mixer in a single unit, which is sufficiently small to enable inter-sensor separation distance as small as 12 mm. The sensor’s input covers the bandwidth from 3 GHz to 7.5 GHz. Its output intermediate frequency (IF) is 30 MHz. The sensor is controlled by a simple bias-switching circuit, which switches ON and OFF the bias of the LNA and the mixer simultaneously. It was demonstrated experimentally that the dynamic range of the sensor, as determined by its ON and OFF states, is 109 dB and 118 dB at resolution bandwidths of 1 kHz and 100 Hz, respectively.

Imaging cardiac activation sequence during ventricular tachycardia in a canine model of nonischemic heart failure.

Science.gov (United States)

Han, Chengzong; Pogwizd, Steven M; Yu, Long; Zhou, Zhaoye; Killingsworth, Cheryl R; He, Bin

2015-01-15

Noninvasive cardiac activation imaging of ventricular tachycardia (VT) is important in the clinical diagnosis and treatment of arrhythmias in heart failure (HF) patients. This study investigated the ability of the three-dimensional cardiac electrical imaging (3DCEI) technique for characterizing the activation patterns of spontaneously occurring and norepinephrine (NE)-induced VTs in a newly developed arrhythmogenic canine model of nonischemic HF. HF was induced by aortic insufficiency followed by aortic constriction in three canines. Up to 128 body-surface ECGs were measured simultaneously with bipolar recordings from up to 232 intramural sites in a closed-chest condition. Data analysis was performed on the spontaneously occurring VTs (n=4) and the NE-induced nonsustained VTs (n=8) in HF canines. Both spontaneously occurring and NE-induced nonsustained VTs initiated by a focal mechanism primarily from the subendocardium, but occasionally from the subepicardium of left ventricle. Most focal initiation sites were located at apex, right ventricular outflow tract, and left lateral wall. The NE-induced VTs were longer, more rapid, and had more focal sites than the spontaneously occurring VTs. Good correlation was obtained between imaged activation sequence and direct measurements (averaged correlation coefficient of ∼0.70 over 135 VT beats). The reconstructed initiation sites were ∼10 mm from measured initiation sites, suggesting good localization in such a large animal model with cardiac size similar to a human. Both spontaneously occurring and NE-induced nonsustained VTs had focal initiation in this canine model of nonischemic HF. 3DCEI is feasible to image the activation sequence and help define arrhythmia mechanism of nonischemic HF-associated VTs. Copyright © 2015 the American Physiological Society.

INTERACTIVE CHANGE DETECTION USING HIGH RESOLUTION REMOTE SENSING IMAGES BASED ON ACTIVE LEARNING WITH GAUSSIAN PROCESSES

Directory of Open Access Journals (Sweden)

H. Ru

2016-06-01

Full Text Available Although there have been many studies for change detection, the effective and efficient use of high resolution remote sensing images is still a problem. Conventional supervised methods need lots of annotations to classify the land cover categories and detect their changes. Besides, the training set in supervised methods often has lots of redundant samples without any essential information. In this study, we present a method for interactive change detection using high resolution remote sensing images with active learning to overcome the shortages of existing remote sensing image change detection techniques. In our method, there is no annotation of actual land cover category at the beginning. First, we find a certain number of the most representative objects in unsupervised way. Then, we can detect the change areas from multi-temporal high resolution remote sensing images by active learning with Gaussian processes in an interactive way gradually until the detection results do not change notably. The artificial labelling can be reduced substantially, and a desirable detection result can be obtained in a few iterations. The experiments on Geo-Eye1 and WorldView2 remote sensing images demonstrate the effectiveness and efficiency of our proposed method.

Active contour based segmentation of resected livers in CT images

Science.gov (United States)

Oelmann, Simon; Oyarzun Laura, Cristina; Drechsler, Klaus; Wesarg, Stefan

2015-03-01

The majority of state of the art segmentation algorithms are able to give proper results in healthy organs but not in pathological ones. However, many clinical applications require an accurate segmentation of pathological organs. The determination of the target boundaries for radiotherapy or liver volumetry calculations are examples of this. Volumetry measurements are of special interest after tumor resection for follow up of liver regrow. The segmentation of resected livers presents additional challenges that were not addressed by state of the art algorithms. This paper presents a snakes based algorithm specially developed for the segmentation of resected livers. The algorithm is enhanced with a novel dynamic smoothing technique that allows the active contour to propagate with different speeds depending on the intensities visible in its neighborhood. The algorithm is evaluated in 6 clinical CT images as well as 18 artificial datasets generated from additional clinical CT images.

Effects of image-based and text-based active learning exercises on student examination performance in a musculoskeletal anatomy course.

Science.gov (United States)

Gross, M Melissa; Wright, Mary C; Anderson, Olivia S

2017-09-01

Research on the benefits of visual learning has relied primarily on lecture-based pedagogy, but the potential benefits of combining active learning strategies with visual and verbal materials on learning anatomy has not yet been explored. In this study, the differential effects of text-based and image-based active learning exercises on examination performance were investigated in a functional anatomy course. Each class session was punctuated with an average of 12 text-based and image-based active learning exercises. Participation data from 231 students were compared with their examination performance on 262 questions associated with the in-class exercises. Students also rated the helpfulness and difficulty of the in-class exercises on a survey. Participation in the active learning exercises was positively correlated with examination performance (r = 0.63, P active learning exercises were helpful for seeing images of key ideas (94%) and clarifying key course concepts (80%), and that the image-based exercises were significantly less demanding, less hard and required less effort than text-based exercises (P active learning strategies on student learning, and suggest that integrating them may be especially beneficial for learning anatomy. Anat Sci Educ 10: 444-455. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Guided filtering for solar image/video processing

Directory of Open Access Journals (Sweden)

Long Xu

2017-06-01

Full Text Available A new image enhancement algorithm employing guided filtering is proposed in this work for enhancement of solar images and videos, so that users can easily figure out important fine structures imbedded in the recorded images/movies for solar observation. The proposed algorithm can efficiently remove image noises, including Gaussian and impulse noises. Meanwhile, it can further highlight fibrous structures on/beyond the solar disk. These fibrous structures can clearly demonstrate the progress of solar flare, prominence coronal mass emission, magnetic field, and so on. The experimental results prove that the proposed algorithm gives significant enhancement of visual quality of solar images beyond original input and several classical image enhancement algorithms, thus facilitating easier determination of interesting solar burst activities from recorded images/movies.

Parallel magnetic resonance imaging

International Nuclear Information System (INIS)

Larkman, David J; Nunes, Rita G

2007-01-01

Parallel imaging has been the single biggest innovation in magnetic resonance imaging in the last decade. The use of multiple receiver coils to augment the time consuming Fourier encoding has reduced acquisition times significantly. This increase in speed comes at a time when other approaches to acquisition time reduction were reaching engineering and human limits. A brief summary of spatial encoding in MRI is followed by an introduction to the problem parallel imaging is designed to solve. There are a large number of parallel reconstruction algorithms; this article reviews a cross-section, SENSE, SMASH, g-SMASH and GRAPPA, selected to demonstrate the different approaches. Theoretical (the g-factor) and practical (coil design) limits to acquisition speed are reviewed. The practical implementation of parallel imaging is also discussed, in particular coil calibration. How to recognize potential failure modes and their associated artefacts are shown. Well-established applications including angiography, cardiac imaging and applications using echo planar imaging are reviewed and we discuss what makes a good application for parallel imaging. Finally, active research areas where parallel imaging is being used to improve data quality by repairing artefacted images are also reviewed. (invited topical review)

Dosimetric verification of radiation therapy including intensity modulated treatments, using an amorphous-silicon electronic portal imaging device

Science.gov (United States)

Chytyk-Praznik, Krista Joy

Radiation therapy is continuously increasing in complexity due to technological innovation in delivery techniques, necessitating thorough dosimetric verification. Comparing accurately predicted portal dose images to measured images obtained during patient treatment can determine if a particular treatment was delivered correctly. The goal of this thesis was to create a method to predict portal dose images that was versatile and accurate enough to use in a clinical setting. All measured images in this work were obtained with an amorphous silicon electronic portal imaging device (a-Si EPID), but the technique is applicable to any planar imager. A detailed, physics-motivated fluence model was developed to characterize fluence exiting the linear accelerator head. The model was further refined using results from Monte Carlo simulations and schematics of the linear accelerator. The fluence incident on the EPID was converted to a portal dose image through a superposition of Monte Carlo-generated, monoenergetic dose kernels specific to the a-Si EPID. Predictions of clinical IMRT fields with no patient present agreed with measured portal dose images within 3% and 3 mm. The dose kernels were applied ignoring the geometrically divergent nature of incident fluence on the EPID. A computational investigation into this parallel dose kernel assumption determined its validity under clinically relevant situations. Introducing a patient or phantom into the beam required the portal image prediction algorithm to account for patient scatter and attenuation. Primary fluence was calculated by attenuating raylines cast through the patient CT dataset, while scatter fluence was determined through the superposition of pre-calculated scatter fluence kernels. Total dose in the EPID was calculated by convolving the total predicted incident fluence with the EPID-specific dose kernels. The algorithm was tested on water slabs with square fields, agreeing with measurement within 3% and 3 mm. The

Significance of increased lung thallium-201 activity on serial cardiac images after dipyridamole treatment in coronary heart disease

International Nuclear Information System (INIS)

Okada, R.D.; Dai, Y.H.; Boucher, C.A.; Pohost, G.M.

1984-01-01

Increased lung thallium-201 (Tl-201) activity occurs in patients with severe coronary artery disease (CAD) on initial postexercise images. To determine the significance of assessing lung Tl-201 on serial imaging after dipyridamole therapy, initial and delayed (2 to 3 hours) Tl-201 imaging was performed in 40 patients with CAD and 26 normal control subjects. Lung Tl-201 activity was quantitated as a percentage of maximal myocardial activity for each imaging time (lung Tl-201 index). The mean initial lung Tl-201 activity was 42 +/- 2% (+/- standard error of the mean) in 26 control subjects, 56 +/- 2% in 25 patients with 2- or 3-vessel CAD (p less than 0.001) and 53 +/- 2% in 15 patients with 1-vessel CAD (p less than 0.005 compared with control subjects) (difference not significant between 1-vessel and multivessel CAD). Dipyridamole lung Tl-201 activity decreased relative to the myocardium from initial to delayed images (p less than 0.001) in patients with CAD but not in control subjects. When a dipyridamole lung Tl-201 index of 58% (mean +/- 2 standard deviations for control subjects) was chosen as the upper limit of normal, 14 of 40 of the CAD patients (35%) had abnormal values and all control patients had values within normal limits. These 14 patients with CAD and abnormal initial lung Tl-201 indexes had rest ejection fractions that were not significantly different from those in patients with CAD, and normal initial dipyridamole lung Tl-201 index (58 +/- 4% and 63 +/- 2%, respectively)

Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

International Nuclear Information System (INIS)

Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke

2000-01-01

Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5±6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33±0.22 in chronic heart failure class I, 2.50±0.34 in class II, 1.95±0.61 in class III, and 1.39±0.29 in class IV (p<0.05). %WR was 24.8±12.8% in chronic heart failure class I, 23.3±10.2% in class II, 49.2±24.5% in class III, and 66.3±26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

Filter and slice thickness selection in SPECT image reconstruction

International Nuclear Information System (INIS)

Ivanovic, M.; Weber, D.A.; Wilson, G.A.; O'Mara, R.E.

1985-01-01

The choice of filter and slice thickness in SPECT image reconstruction as function of activity and linear and angular sampling were investigated in phantom and patient imaging studies. Reconstructed transverse and longitudinal spatial resolution of the system were measured using a line source in a water filled phantom. Phantom studies included measurements of the Data Spectrum phantom; clinical studies included tomographic procedures in 40 patients undergoing imaging of the temporomandibular joint. Slices of the phantom and patient images were evaluated for spatial of the phantom and patient images were evaluated for spatial resolution, noise, and image quality. Major findings include; spatial resolution and image quality improve with increasing linear sampling frequencies over the range of 4-8 mm/p in the phantom images, best spatial resolution and image quality in clinical images were observed at a linear sampling frequency of 6mm/p, Shepp and Logan filter gives the best spatial resolution for phantom studies at the lowest linear sampling frequency; smoothed Shepp and Logan filter provides best quality images without loss of resolution at higher frequencies and, spatial resolution and image quality improve with increased angular sampling frequency in the phantom at 40 c/p but appear to be independent of angular sampling frequency at 400 c/p

Magnetic resonance imaging findings as predictors of clinical outcome in patients with sciatica receiving active conservative treatment

DEFF Research Database (Denmark)

Jensen, Tue Secher; Albert, Hanne B; Sorensen, Joan S

2007-01-01

OBJECTIVE: The aims of this study were to investigate the possible prognostic value of disk-related magnetic resonance imaging (MRI) findings in relation to recovery at 14 months in patients with severe sciatica, and whether improvement of disk herniation and/or nerve root compromise is concurrent...... with recovery. METHODS: All patients included in this prospective observational study of patients with sciatica receiving active conservative treatment were scanned at baseline and at 14 months' follow-up. Definite recovery at follow-up was defined as an absence of sciatic leg pain and a Roland Morris...... in that the prevalence of disk-related MRI findings was different for men and women, and they had different recovery rates. Improvement of disk herniations and nerve root compromise over time did not coincide with definite recovery. CONCLUSIONS: In patients with sciatica receiving active conservative treatment, broad...

An automated approach for segmentation of intravascular ultrasound images based on parametric active contour models

International Nuclear Information System (INIS)

Vard, Alireza; Jamshidi, Kamal; Movahhedinia, Naser

2012-01-01

This paper presents a fully automated approach to detect the intima and media-adventitia borders in intravascular ultrasound images based on parametric active contour models. To detect the intima border, we compute a new image feature applying a combination of short-term autocorrelations calculated for the contour pixels. These feature values are employed to define an energy function of the active contour called normalized cumulative short-term autocorrelation. Exploiting this energy function, the intima border is separated accurately from the blood region contaminated by high speckle noise. To extract media-adventitia boundary, we define a new form of energy function based on edge, texture and spring forces for the active contour. Utilizing this active contour, the media-adventitia border is identified correctly even in presence of branch openings and calcifications. Experimental results indicate accuracy of the proposed methods. In addition, statistical analysis demonstrates high conformity between manual tracing and the results obtained by the proposed approaches.

A generalized model for optimal transport of images including dissipation and density modulation

KAUST Repository

Maas, Jan; Rumpf, Martin; Schö nlieb, Carola; Simon, Stefan

2015-01-01

transport to strongly dissipative dynamics. For this model a robust and effective variational time discretization of geodesic paths is proposed. This requires to minimize a discrete path energy consisting of a sum of consecutive image matching functionals

Evolution of Choroidal Neovascularization due to Presumed Ocular Histoplasmosis Syndrome on Multimodal Imaging including Optical Coherence Tomography Angiography

Directory of Open Access Journals (Sweden)

T. Y. Alvin Liu

2018-01-01

Full Text Available A 37-year-old Caucasian woman presented with acute decrease in central vision in her right eye and was found to have subfoveal choroidal neovascularization (CNV due to presumed ocular histoplasmosis syndrome (POHS. Her visual acuity improved from 20/70 to 20/20 at her 6-month follow-up, after 3 consecutive monthly intravitreal bevacizumab injections were initiated at her first visit. Although no CNV activity was seen on fluorescein angiography (FA or spectral-domain optical coherence tomography (SD-OCT at her 2-month, 4-month, and 6-month follow-up visits, persistent flow in the CNV lesion was detected on optical coherence tomography angiography (OCTA. OCTA shows persistent vascular flow as well as changes in vascular flow in CNV lesions associated with POHS, indicating the continued presence of patent vessels and changes in these CNV lesions, even when traditional imaging of the lesion with OCT and FA indicates stability of the lesion with no disease activity. Additional cases with longitudinal follow-up are needed to assess how OCTA should be incorporated into clinical practice.

A convolution method for predicting mean treatment dose including organ motion at imaging

International Nuclear Information System (INIS)

Booth, J.T.; Zavgorodni, S.F.; Royal Adelaide Hospital, SA

2000-01-01

Full text: The random treatment delivery errors (organ motion and set-up error) can be incorporated into the treatment planning software using a convolution method. Mean treatment dose is computed as the convolution of a static dose distribution with a variation kernel. Typically this variation kernel is Gaussian with variance equal to the sum of the organ motion and set-up error variances. We propose a novel variation kernel for the convolution technique that additionally considers the position of the mobile organ in the planning CT image. The systematic error of organ position in the planning CT image can be considered random for each patient over a population. Thus the variance of the variation kernel will equal the sum of treatment delivery variance and organ motion variance at planning for the population of treatments. The kernel is extended to deal with multiple pre-treatment CT scans to improve tumour localisation for planning. Mean treatment doses calculated with the convolution technique are compared to benchmark Monte Carlo (MC) computations. Calculations of mean treatment dose using the convolution technique agreed with MC results for all cases to better than ± 1 Gy in the planning treatment volume for a prescribed 60 Gy treatment. Convolution provides a quick method of incorporating random organ motion (captured in the planning CT image and during treatment delivery) and random set-up errors directly into the dose distribution. Copyright (2000) Australasian College of Physical Scientists and Engineers in Medicine

Assisting in Radiology/Imaging. Instructor's Guide, Student's Manual, and Student Learning Activities.

Science.gov (United States)

Fair, Helena J.

The instructor's guide, the first of three documents in this package, is designed for a course to help students who are investigating the activities within a radiology department or considering any of the imaging technologies as a career. The material is designed to relate training experience to information studied in the classroom. This…

Noise analysis of a novel hybrid active-passive pixel sensor for medical X-ray imaging

International Nuclear Information System (INIS)

Safavian, N.; Izadi, M.H.; Sultana, A.; Wu, D.; Karim, K.S.; Nathan, A.; Rowlands, J.A.

2009-01-01

Passive pixel sensor (PPS) is one of the most widely used architectures in large area amorphous silicon (a-Si) flat panel imagers. It consists of a detector and a thin film transistor (TFT) acting as a readout switch. While the PPS is advantageous in terms of providing a simple and small architecture suitable for high-resolution imaging, it directly exposes the signal to the noise of data line and external readout electronics, causing significant increase in the minimum readable sensor input signal. In this work we present the operation and noise performance of a hybrid 3-TFT current programmed, current output active pixel sensor (APS) suitable for real-time X-ray imaging. The pixel circuit extends the application of a-Si TFT from conventional switching element to on-pixel amplifier for enhanced signal-to-noise ratio and higher imager dynamic range. The capability of operation in both passive and active modes as well as being able to compensate for inherent instabilities of the TFTs makes the architecture a good candidate for X-ray imaging modalities with a wide range of incoming X-ray intensities. Measurement and theoretical calculations reveal a value for input refferd noise below the 1000 electron noise limit for real-time fluoroscopy. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Empirical electro-optical and x-ray performance evaluation of CMOS active pixels sensor for low dose, high resolution x-ray medical imaging

International Nuclear Information System (INIS)

Arvanitis, C. D.; Bohndiek, S. E.; Royle, G.; Blue, A.; Liang, H. X.; Clark, A.; Prydderch, M.; Turchetta, R.; Speller, R.

2007-01-01

Monolithic complementary metal oxide semiconductor (CMOS) active pixel sensors with high performance have gained attention in the last few years in many scientific and space applications. In order to evaluate the increasing capabilities of this technology, in particular where low dose high resolution x-ray medical imaging is required, critical electro-optical and physical x-ray performance evaluation was determined. The electro-optical performance includes read noise, full well capacity, interacting quantum efficiency, and pixels cross talk. The x-ray performance, including x-ray sensitivity, modulation transfer function, noise power spectrum, and detection quantum efficiency, has been evaluated in the mammographic energy range. The sensor is a 525x525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25x25 μm pixel pitch. Reading at 10 f/s, it is found that the sensor has 114 electrons total additive noise, 10 5 electrons full well capacity with shot noise limited operation, and 34% interacting quantum efficiency at 530 nm. Two different structured CsI:Tl phosphors with thickness 95 and 115 μm, respectively, have been optically coupled via a fiber optic plate to the array resulting in two different system configurations. The sensitivity of the two different system configurations was 43 and 47 electrons per x-ray incident on the sensor. The MTF at 10% of the two different system configurations was 9.5 and 9 cycles/mm with detective quantum efficiency of 0.45 and 0.48, respectively, close to zero frequency at ∼0.44 μC/kg (1.72 mR) detector entrance exposure. The detector was quantum limited at low spatial frequencies and its performance was comparable with high resolution a:Si and charge coupled device based x-ray imagers. The detector also demonstrates almost an order of magnitude lower noise than active matrix flat panel imagers. The results suggest that CMOS active pixel sensors when coupled to structured CsI:Tl can

Greater anterior insula activation during anticipation of food images in women recovered from anorexia nervosa versus controls

Science.gov (United States)

Oberndorfer, Tyson; Simmons, Alan; McCurdy, Danyale; Strigo, Irina; Matthews, Scott; Yang, Tony; Irvine, Zoe; Kaye, Walter

2013-01-01

Individuals with anorexia nervosa (AN) restrict food consumption and become severely emaciated. Eating food, even thinking of eating food, is often associated with heightened anxiety. However, food cue anticipation in AN is poorly understood. Fourteen women recovered from AN and 12 matched healthy control women performed an anticipation task viewing images of food and object images during functional magnetic resonance imaging. Comparing anticipation of food versus object images between control women and recovered AN groups showed significant interaction only in the right ventral anterior insula, with greater activation in recovered AN anticipating food images. These data support the hypothesis of a disconnect between anticipating and experiencing food stimuli in recovered AN. Insula activation positively correlated with pleasantness ratings of palatable foods in control women, while no such relationship existed in recovered AN, which is further evidence of altered interoceptive function. Finally, these findings raise the possibility that enhanced anterior insula anticipatory response to food cues in recovered AN could contribute to exaggerated sensitivity and anxiety related to food and eating. PMID:23993362

A novel neural network based image reconstruction model with scale and rotation invariance for target identification and classification for Active millimetre wave imaging

Science.gov (United States)

Agarwal, Smriti; Bisht, Amit Singh; Singh, Dharmendra; Pathak, Nagendra Prasad

2014-12-01

Millimetre wave imaging (MMW) is gaining tremendous interest among researchers, which has potential applications for security check, standoff personal screening, automotive collision-avoidance, and lot more. Current state-of-art imaging techniques viz. microwave and X-ray imaging suffers from lower resolution and harmful ionizing radiation, respectively. In contrast, MMW imaging operates at lower power and is non-ionizing, hence, medically safe. Despite these favourable attributes, MMW imaging encounters various challenges as; still it is very less explored area and lacks suitable imaging methodology for extracting complete target information. Keeping in view of these challenges, a MMW active imaging radar system at 60 GHz was designed for standoff imaging application. A C-scan (horizontal and vertical scanning) methodology was developed that provides cross-range resolution of 8.59 mm. The paper further details a suitable target identification and classification methodology. For identification of regular shape targets: mean-standard deviation based segmentation technique was formulated and further validated using a different target shape. For classification: probability density function based target material discrimination methodology was proposed and further validated on different dataset. Lastly, a novel artificial neural network based scale and rotation invariant, image reconstruction methodology has been proposed to counter the distortions in the image caused due to noise, rotation or scale variations. The designed neural network once trained with sample images, automatically takes care of these deformations and successfully reconstructs the corrected image for the test targets. Techniques developed in this paper are tested and validated using four different regular shapes viz. rectangle, square, triangle and circle.

Transferring biomarker into molecular probe: melanin nanoparticle as a naturally active platform for multimodality imaging.

Science.gov (United States)

Fan, Quli; Cheng, Kai; Hu, Xiang; Ma, Xiaowei; Zhang, Ruiping; Yang, Min; Lu, Xiaomei; Xing, Lei; Huang, Wei; Gambhir, Sanjiv Sam; Cheng, Zhen

2014-10-29

Developing multifunctional and easily prepared nanoplatforms with integrated different modalities is highly challenging for molecular imaging. Here, we report the successful transfer of an important molecular target, melanin, into a novel multimodality imaging nanoplatform. Melanin is abundantly expressed in melanotic melanomas and thus has been actively studied as a target for melanoma imaging. In our work, the multifunctional biopolymer nanoplatform based on ultrasmall (passive nanoplatforms require complicated and time-consuming processes for prebuilding reporting moieties or chemical modifications using active groups to integrate different contrast properties into one entity. In comparison, utilizing functional biomarker melanin can greatly simplify the building process. We further conjugated αvβ3 integrins, cyclic c(RGDfC) peptide, to MNPs to allow for U87MG tumor accumulation due to its targeting property combined with the enhanced permeability and retention (EPR) effect. The multimodal properties of MNPs demonstrate the high potential of endogenous materials with multifunctions as nanoplatforms for molecular theranostics and clinical translation.

[A correlation between diffusion kurtosis imaging and the proliferative activity of brain glioma].

Science.gov (United States)

Tonoyan, A S; Pronin, I N; Pitshelauri, D I; Shishkina, L V; Fadeeva, L M; Pogosbekyan, E L; Zakharova, N E; Shults, E I; Khachanova, N V; Kornienko, V N; Potapov, A A

2015-01-01

The aim of the study was to assess the capabilities of diffusion kurtosis imaging (DKI) in diagnosis of the glioma proliferative activity and to evaluate a relationship between the glioma proliferative activity index and diffusion parameters of the contralateral normal appearing white matter (CNAWM). The study included 47 patients with newly diagnosed brain gliomas (23 low grade, 13 grade III, and 11 grade IV gliomas). We determined a relationship between absolute and normalized parameters of the diffusion tensor (mean (MD), axial (AD), and radial (RD) diffusivities; fractional (FA) and relative (RA) anisotropies) and diffusion kurtosis (mean (MK), axial (AK), and radial (RK) kurtosis; kurtosis anisotropy (KA)) and the proliferative activity index in the most malignant glioma parts (pAK, and RK) and anisotropy (KA, FA, RA) values increased, and diffusivity (MD, AD, RD) values decreased as the glioma proliferative activity index increased. A strong correlation between the proliferative activity index and absolute RK (r=0,71; p=0.000001) and normalized values of MK (r=0.8; p=0.000001), AK (r=0.71; p=0.000001), RK (r=0.81; p=0.000001), and RD (r=-0.71; p=0.000001) was found. A weak, but statistically significant correlation between the glioma proliferative activity index and diffusion values RK (r=-0.36; p=0.014), KA (r=-0.39; p=0.007), RD (r=0.35; p=0.017), FA (r=-0.42; p=0.003), and RA (r=-0.41; p=0.004) of CNAWM was found. DKI has good capabilities to detect immunohistochemical changes in gliomas. DKI demonstrated a high sensitivity in detection of microstructural changes in the contralateral normal appearing white matter in patients with brain gliomas.

Three-dimensional reconstruction of functional brain images

International Nuclear Information System (INIS)

Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao

1999-01-01

We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface

Three-dimensional reconstruction of functional brain images

Energy Technology Data Exchange (ETDEWEB)

Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao [Kyoto Univ. (Japan)

1999-08-01

We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface

Magnetic resonance imaging of tumor oxygenation and metabolic profile

DEFF Research Database (Denmark)

Krishna, Murali C.; Matsumoto, Shingo; Saito, Keita

2013-01-01

The tumor microenvironment is distinct from normal tissue as a result of abnormal vascular network characterized by hypoxia, low pH, high interstitial fluid pressure and elevated glycolytic activity. This poses a barrier to treatments including radiation therapy and chemotherapy. Imaging methods...... spectroscopic imaging. Imaging pO2 in tumors is now a robust pre-clinical imaging modality with potential for implementation clinically. Pre-clinical studies and an initial clinical study with hyperpolarized metabolic MR have been successful and suggest that the method may be part of image-guided radiotherapy...

The translocator protein ligand [{sup 18}F]DPA-714 images glioma and activated microglia in vivo

Energy Technology Data Exchange (ETDEWEB)

Winkeler, Alexandra; Boisgard, Raphael; Awde, Ali R.; Dubois, Albertine; Theze, Benoit; Zheng, Jinzi [Universite Paris Sud, Inserm, U1023, Laboratoire d' Imagerie Moleculaire Experimentale, Orsay (France); CEA, I2BM, SHFJ, Orsay (France); Ciobanu, Luisa [CEA, DSV, I2BM, NeuroSpin, LRMN, Gif sur Yvette (France); Dolle, Frederic [CEA, I2BM, SHFJ, Orsay (France); Viel, Thomas; Jacobs, Andreas H. [Westfaelische Wilhelm-Universitaet Muenster (WWU), European Institute for Molecular Imaging (EIMI), Muenster (Germany); Tavitian, Bertrand [Universite Paris Sud, Inserm, U1023, Laboratoire d' Imagerie Moleculaire Experimentale, Orsay (France)

2012-05-15

In recent years there has been an increase in the development of radioligands targeting the 18-kDa translocator protein (TSPO). TSPO expression is well documented in activated microglia and serves as a biomarker for imaging neuroinflammation. In addition, TSPO has also been reported to be overexpressed in a number of cancer cell lines and human tumours including glioma. Here we investigated the use of [{sup 18}F]DPA-714, a new TSPO positron emission tomography (PET) radioligand to image glioma in vivo. We studied the uptake of [{sup 18}F]DPA-714 in three different rat strains implanted with 9L rat glioma cells: Fischer (F), Wistar (W) and Sprague Dawley (SD) rats. Dynamic [{sup 18}F]DPA-714 PET imaging, kinetic modelling of PET data and in vivo displacement studies using unlabelled DPA-714 and PK11195 were performed. Validation of TSPO expression in 9L glioma cell lines and intracranial 9L gliomas were investigated using Western blotting and immunohistochemistry of brain tissue sections. All rats showed significant [{sup 18}F]DPA-714 PET accumulation at the site of 9L tumour implantation compared to the contralateral brain hemisphere with a difference in uptake among the three strains (F > W > SD). The radiotracer showed high specificity for TSPO as demonstrated by the significant reduction of [{sup 18}F]DPA-714 binding in the tumour after administration of unlabelled DPA-714 or PK11195. TSPO expression was confirmed by Western blotting in 9L cells in vitro and by immunohistochemistry ex vivo. The TSPO radioligand [{sup 18}F]DPA-714 can be used for PET imaging of intracranial 9L glioma in different rat strains. This preclinical study demonstrates the feasibility of employing [{sup 18}F]DPA-714 as an alternative radiotracer to image human glioma. (orig.)

Small-Animal Imaging Using Diffuse Fluorescence Tomography.

Science.gov (United States)

Davis, Scott C; Tichauer, Kenneth M

2016-01-01

Diffuse fluorescence tomography (DFT) has been developed to image the spatial distribution of fluorescence-tagged tracers in living tissue. This capability facilitates the recovery of any number of functional parameters, including enzymatic activity, receptor density, blood flow, and gene expression. However, deploying DFT effectively is complex and often requires years of know-how, especially for newer mutlimodal systems that combine DFT with conventional imaging systems. In this chapter, we step through the process of using MRI-DFT imaging of a receptor-targeted tracer in small animals.

Episodic aphasia associated with tumor active multiple sclerosis: a correlative SPECT study utilising image fusion

International Nuclear Information System (INIS)

Roff, G.; Campbell, A.; Lawn, N.; Henderson, A.; McCarthy, M.; Lenzo, N.

2003-01-01

Full text: Cerebral perfusion imaging is a common technique to assess cerebral perfusion and metabolism. It can complement anatomical imaging in assessing a number of neurological conditions. At times it can better define the clinical manifestations of a disease process than anatomical imaging alone. We present a clinical case whereby cerebral SPECT imaging helped define the physiological reason for intermittent aphasia in a patient with tumor active multiple sclerotic white matter plaques. Cerebral SPECT studies were performed during a period of aphasia and when the patient had recovered. We utilised subtraction analyses and image fusion techniques to better define the changes seen on SPECT. We discuss the neuroanatomical relationship of aphasia and the automatic fusion technique that allows accurate co-registration of the MRI and SPECT data. Copyright (2003) The Australian and New Zealand Society of Nuclear Medicine Inc

Minimising activity and dose with enhanced image quality by radiopharmaceutical administrations

International Nuclear Information System (INIS)

Hoeschen, C.; Mattsson, S.; Cantone, M. C.; Mikuz, M.; Lacasta, C.; Ebel, G.; Clinthorne, N.; Giussani, A.

2010-01-01

Owing to the introduction of new diagnostic procedures, such as computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT), the individual dose caused by medical exposures has grown rapidly in the last years. This is especially a subject to radiation protection for nuclear medical diagnosis, since in this case radiopharmaceuticals are administered to the patient, meaning not only a radiation exposure to the diseased tissue but also to the healthy tissues of large parts of the body. 'Minimizing Activity and Dose with Enhanced Image quality by Radiopharmaceutical Administrations' (MADEIRA) is a project co-funded by the European Commission within the Seventh Euratom Framework Programme that aims to improve three-dimensional (3D) nuclear medical imaging technologies significantly. MADEIRA is aiming to improve the efficacy and safety of 3D PET and SPECT functional imaging by optimising the spatial resolution and the signal-to-noise ratio, improving the knowledge of the temporal variation of the radiopharmaceuticals' uptake in and clearance from tumorous and healthy tissues, and evaluation of the corresponding patient dose. Using an optimised imaging procedure that improves the information gained per unit administered dose, MADEIRA aims especially to reduce the dose to healthy tissues of the patient. In this paper, an overall summary of the current achievements will be presented. (authors)

Calibration of Cherenkov detectors for monoenergetic photon imaging in active interrogation applications

Energy Technology Data Exchange (ETDEWEB)

Rose, P.B., E-mail: prose6@gatech.edu; Erickson, A.S., E-mail: anna.erickson@me.gatech.edu

2015-11-01

Active interrogation of cargo containers using monoenergetic photons offers a rapid and low-dose approach to search for shielded special nuclear materials. Cherenkov detectors can be used for imaging of the cargo provided that gamma ray energies used in interrogation are well resolved, as the case in {sup 11}B(d,n-γ){sup 12}C reaction resulting in 4.4 MeV and 15.1 MeV photons. While an array of Cherenkov threshold detectors reduces low energy background from scatter while providing the ability of high contrast transmission imaging, thus confirming the presence of high-Z materials, these detectors require a special approach to energy calibration due to the lack of resolution. In this paper, we discuss the utility of Cherenkov detectors for active interrogation with monoenergetic photons as well as the results of computational and experimental studies of their energy calibration. The results of the studies with sources emitting monoenergetic photons as well as complex gamma ray spectrum sources, for example {sup 232}Th, show that calibration is possible as long as the energies of photons of interest are distinct.

The brain smell centres - comparison of localisation and activation in male and female subjects using functional MR imaging

International Nuclear Information System (INIS)

Marchwicka-Wasiak, M.; Goraj, B.

2004-01-01

The study was conducted in order to determine and to compare the location and activation of smell brain centres in females and males brains using olfactory nerve-mediated (geraniol) and combined olfactory and trigeminal nerve-mediated (patchouli) stimulants. 10 normal volunteers (five women and five men), right-handed, non-smokers, without any CNS diseases were examined to determine the activated cortex areas during stimulation by geraniol and patchouli. MR brain scans were obtained using a 1.5 T clinical scanner, with the head-neck coil. The imaging was performed in each subject using SE and EPI sequences with a blood-oxygen-level-dependent (BOLD) effect. The individual inhaled odorized air during the 30 seconds period and alternating room air over the same period. The mean pixel intensity of activated images was substracted from the mean pixel intensity of preactivated images. The olfactory system-mediated stimuli (geraniol) evoked bilateral activation of female brains smell centres and right hemisphere centres activation in male brains. The exposure to the olfactory and trigeminal nerve-mediated stimuli (patchouli) showed more activated regions in both sexes than to the olfactory nerve-ediated stimuli. fMRI proved to be a useful method to compare the location and activation of male and female brain smell centres. (author)

Intravenous streptokinase therapy in acute myocardial infarction: Assessment of therapy effects by quantitative 201Tl myocardial imaging (including SPECT) and radionuclide ventriculography

International Nuclear Information System (INIS)

Koehn, H.; Bialonczyk, C.; Mostbeck, A.; Frohner, K.; Unger, G.; Steinbach, K.

1984-01-01

To evaluate a potential beneficial effect of systemic streptokinase therapy in acute myocardial infarction, 36 patients treated with streptokinase intravenously were assessed by radionuclide ventriculography and quantitative 201 Tl myocardial imaging (including SPECT) in comparison with 18 conventionally treated patients. Patients after thrombolysis had significantly higher EF, PFR, and PER as well as fewer wall motion abnormalities compared with controls. These differences were also observed in the subset of patients with anterior wall infarction (AMI), but not in patients with inferior wall infarction (IMI). Quantitative 201 Tl imaging demonstrated significantly smaller percent myocardial defects and fewer pathological stress segments in patients with thrombolysis compared with controls. The same differences were also found in both AMI and IMI patients. Our data suggest a favorable effect of intravenous streptokinase on recovery of left ventricular function and myocardial salvage. Radionuclide ventriculography and quantitative 201 Tl myocardial imaging seem to be reliable tools for objective assessment of therapy effects. (orig.)

Feasibility and resolution limits of opto-magnetic imaging of neural network activity in brain slices using color centers in diamond

DEFF Research Database (Denmark)

Karadas, Mürsel; Wojciechowski, Adam M.; Huck, Alexander

2018-01-01

We suggest a novel approach for wide-field imaging of the neural network dynamics of brain slices that uses highly sensitivity magnetometry based on nitrogen-vacancy (NV) centers in diamond. Invitro recordings in brain slices is a proven method for the characterization of electrical neural activi...... cell. Our results suggest that imaging of slice activity will be possible with the upcoming generation of NV magnetic field sensors, while single-shot imaging of planar cell activity remains challenging....

Thermal Infrared Imaging-Based Computational Psychophysiology for Psychometrics.

Science.gov (United States)

Cardone, Daniela; Pinti, Paola; Merla, Arcangelo

2015-01-01

Thermal infrared imaging has been proposed as a potential system for the computational assessment of human autonomic nervous activity and psychophysiological states in a contactless and noninvasive way. Through bioheat modeling of facial thermal imagery, several vital signs can be extracted, including localized blood perfusion, cardiac pulse, breath rate, and sudomotor response, since all these parameters impact the cutaneous temperature. The obtained physiological information could then be used to draw inferences about a variety of psychophysiological or affective states, as proved by the increasing number of psychophysiological studies using thermal infrared imaging. This paper presents therefore a review of the principal achievements of thermal infrared imaging in computational physiology with regard to its capability of monitoring psychophysiological activity.

Early dynamic imaging in {sup 68}Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions

Energy Technology Data Exchange (ETDEWEB)

Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; Guggenberg, Elisabeth von; Virgolini, Irene Johanna [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Fritz, Josef [Medical University Innsbruck, Department for Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Bektic, Jasmin; Horninger, Wolfgang [Medical University Innsbruck, Department of Urology, Innsbruck (Austria)

2017-05-15

PET/CT with {sup 68}Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic {sup 68}Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to {sup 68}Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV{sub max} of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic {sup 68}Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv{sub max} was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p < 0.001). In the subgroup of PC patients with biochemical relapse the detection rate of local recurrence could be increased from 20.3 to 29.7%. Early dynamic imaging in {sup 68}Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic

Early dynamic imaging in "6"8Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions

International Nuclear Information System (INIS)

Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; Guggenberg, Elisabeth von; Virgolini, Irene Johanna; Fritz, Josef; Bektic, Jasmin; Horninger, Wolfgang

2017-01-01

PET/CT with "6"8Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic "6"8Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to "6"8Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV_m_a_x of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic "6"8Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv_m_a_x was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p < 0.001). In the subgroup of PC patients with biochemical relapse the detection rate of local recurrence could be increased from 20.3 to 29.7%. Early dynamic imaging in "6"8Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic bladder accumulation

Continuous, high-resolution biospeckle imaging reveals a discrete zone of activity at the root apex that responds to contact with obstacles.

Science.gov (United States)

Ribeiro, K M; Barreto, B; Pasqual, M; White, P J; Braga, R A; Dupuy, L X

2014-02-01

Shining a laser onto biological material produces light speckles termed biospeckles. Patterns of biospeckle activity reflect changes in cell biochemistry, developmental processes and responses to the environment. The aim of this work was to develop methods to investigate the biospeckle activity in roots and to characterize the distribution of its intensity and response to thigmostimuli. Biospeckle activity in roots of Zea mays, and also Jatropha curcas and Citrus limonia, was imaged live and in situ using a portable laser and a digital microscope with a spatial resolution of 10 μm per pixel and the ability to capture images every 0.080 s. A procedure incorporating a Fujii algorithm, image restoration using median and Gaussian filters, image segmentation using maximum-entropy threshold methods and the extraction of features using a tracing algorithm followed by spline fitting were developed to obtain quantitative information from images of biospeckle activity. A wavelet transform algorithm was used for spectral decomposition of biospeckle activity and generalized additive models were used to attribute statistical significance to changes in patterns of biospeckle activity. The intensity of biospeckle activity was greatest close to the root apex. Higher frequencies (3-6 Hz) contributed most to the total intensity of biospeckle activity. When a root encountered an obstacle, the intensity of biospeckle activity decreased abruptly throughout the root system. The response became attenuated with repeated thigmostimuli. The data suggest that at least one component of root biospeckle activity resulted from a biological process, which is located in the zone of cell division and responds to thigmostimuli. However, neither individual cell division events nor root elongation is likely to be responsible for the patterns of biospeckle activity.

Validated automatic segmentation of AMD pathology including drusen and geographic atrophy in SD-OCT images.

Science.gov (United States)

Chiu, Stephanie J; Izatt, Joseph A; O'Connell, Rachelle V; Winter, Katrina P; Toth, Cynthia A; Farsiu, Sina

2012-01-05

To automatically segment retinal spectral domain optical coherence tomography (SD-OCT) images of eyes with age-related macular degeneration (AMD) and various levels of image quality to advance the study of retinal pigment epithelium (RPE)+drusen complex (RPEDC) volume changes indicative of AMD progression. A general segmentation framework based on graph theory and dynamic programming was used to segment three retinal boundaries in SD-OCT images of eyes with drusen and geographic atrophy (GA). A validation study for eyes with nonneovascular AMD was conducted, forming subgroups based on scan quality and presence of GA. To test for accuracy, the layer thickness results from two certified graders were compared against automatic segmentation results for 220 B-scans across 20 patients. For reproducibility, automatic layer volumes were compared that were generated from 0° versus 90° scans in five volumes with drusen. The mean differences in the measured thicknesses of the total retina and RPEDC layers were 4.2 ± 2.8 and 3.2 ± 2.6 μm for automatic versus manual segmentation. When the 0° and 90° datasets were compared, the mean differences in the calculated total retina and RPEDC volumes were 0.28% ± 0.28% and 1.60% ± 1.57%, respectively. The average segmentation time per image was 1.7 seconds automatically versus 3.5 minutes manually. The automatic algorithm accurately and reproducibly segmented three retinal boundaries in images containing drusen and GA. This automatic approach can reduce time and labor costs and yield objective measurements that potentially reveal quantitative RPE changes in longitudinal clinical AMD studies. (ClinicalTrials.gov number, NCT00734487.).

Near-field three-dimensional radar imaging techniques and applications.

Science.gov (United States)

Sheen, David; McMakin, Douglas; Hall, Thomas

2010-07-01

Three-dimensional radio frequency imaging techniques have been developed for a variety of near-field applications, including radar cross-section imaging, concealed weapon detection, ground penetrating radar imaging, through-barrier imaging, and nondestructive evaluation. These methods employ active radar transceivers that operate at various frequency ranges covering a wide range, from less than 100 MHz to in excess of 350 GHz, with the frequency range customized for each application. Computational wavefront reconstruction imaging techniques have been developed that optimize the resolution and illumination quality of the images. In this paper, rectilinear and cylindrical three-dimensional imaging techniques are described along with several application results.

Engaging luxury consumers in social media : Does active consumer engagement influence brand image?

OpenAIRE

Åvall, Martina

2017-01-01

This study aimed to investigate the effects of active consumer engagement within social media based brand communities on the brand image and luxury consumers’ desire to pur-chase luxury goods. The purpose of this study was to prove that by actively engaging con-sumers on social media luxury brands can positively influence the way consumers perceive the brand and through it increase consumers’ intention to purchase their products and services. Secondary research was carried out through col...

Active Contour Driven by Local Region Statistics and Maximum A Posteriori Probability for Medical Image Segmentation

Directory of Open Access Journals (Sweden)

Xiaoliang Jiang

2014-01-01

Full Text Available This paper presents a novel active contour model in a variational level set formulation for simultaneous segmentation and bias field estimation of medical images. An energy function is formulated based on improved Kullback-Leibler distance (KLD with likelihood ratio. According to the additive model of images with intensity inhomogeneity, we characterize the statistics of image intensities belonging to each different object in local regions as Gaussian distributions with different means and variances. Then, we use the Gaussian distribution with bias field as a local region descriptor in level set formulation for segmentation and bias field correction of the images with inhomogeneous intensities. Therefore, image segmentation and bias field estimation are simultaneously achieved by minimizing the level set formulation. Experimental results demonstrate desirable performance of the proposed method for different medical images with weak boundaries and noise.

Activity in the fusiform face area supports expert perception in radiologists and does not depend upon holistic processing of images

Science.gov (United States)

Engel, Stephen A.; Harley, Erin M.; Pope, Whitney B.; Villablanca, J. Pablo; Mazziotta, John C.; Enzmann, Dieter

2009-02-01

Training in radiology dramatically changes observers' ability to process images, but the neural bases of this visual expertise remain unexplored. Prior imaging work has suggested that the fusiform face area (FFA), normally selectively responsive to faces, becomes responsive to images in observers' area of expertise. The FFA has been hypothesized to be important for "holistic" processing that integrates information across the entire image. Here, we report a cross-sectional study of radiologists that used functional magnetic resonance imaging to measure neural activity in first-year radiology residents, fourth-year radiology residents, and practicing radiologists as they detected abnormalities in chest radiographs. Across subjects, activity in the FFA correlated with visual expertise, measured as behavioral performance during scanning. To test whether processing in the FFA was holistic, we measured its responses both to intact radiographs and radiographs that had been divided into 25 square pieces whose locations were scrambled. Activity in the FFA was equal in magnitude for intact and scrambled images, and responses to both kinds of stimuli correlated reliably with expertise. These results suggest that the FFA is one of the cortical regions that provides the basis of expertise in radiology, but that its contribution is not holistic processing of images.

Modulation of the semantic system by word imageability.

Science.gov (United States)

Sabsevitz, D S; Medler, D A; Seidenberg, M; Binder, J R

2005-08-01

A prevailing neurobiological theory of semantic memory proposes that part of our knowledge about concrete, highly imageable concepts is stored in the form of sensory-motor representations. While this theory predicts differential activation of the semantic system by concrete and abstract words, previous functional imaging studies employing this contrast have provided relatively little supporting evidence. We acquired event-related functional magnetic resonance imaging (fMRI) data while participants performed a semantic similarity judgment task on a large number of concrete and abstract noun triads. Task difficulty was manipulated by varying the degree to which the words in the triad were similar in meaning. Concrete nouns, relative to abstract nouns, produced greater activation in a bilateral network of multimodal and heteromodal association areas, including ventral and medial temporal, posterior-inferior parietal, dorsal prefrontal, and posterior cingulate cortex. In contrast, abstract nouns produced greater activation almost exclusively in the left hemisphere in superior temporal and inferior frontal cortex. Increasing task difficulty modulated activation mainly in attention, working memory, and response monitoring systems, with almost no effect on areas that were modulated by imageability. These data provide critical support for the hypothesis that concrete, imageable concepts activate perceptually based representations not available to abstract concepts. In contrast, processing abstract concepts makes greater demands on left perisylvian phonological and lexical retrieval systems. The findings are compatible with dual coding theory and less consistent with single-code models of conceptual representation. The lack of overlap between imageability and task difficulty effects suggests that once the neural representation of a concept is activated, further maintenance and manipulation of that information in working memory does not further increase neural activation in

CT Image Contrast of High-Z Elements: Phantom Imaging Studies and Clinical Implications.

Science.gov (United States)

FitzGerald, Paul F; Colborn, Robert E; Edic, Peter M; Lambert, Jack W; Torres, Andrew S; Bonitatibus, Peter J; Yeh, Benjamin M

2016-03-01

To quantify the computed tomographic (CT) image contrast produced by potentially useful contrast material elements in clinically relevant imaging conditions. Equal mass concentrations (grams of active element per milliliter of solution) of seven radiodense elements, including iodine, barium, gadolinium, tantalum, ytterbium, gold, and bismuth, were formulated as compounds in aqueous solutions. The compounds were chosen such that the active element dominated the x-ray attenuation of the solution. The solutions were imaged within a modified 32-cm CT dose index phantom at 80, 100, 120, and 140 kVp at CT. To simulate larger body sizes, 0.2-, 0.5-, and 1.0-mm-thick copper filters were applied. CT image contrast was measured and corrected for measured concentrations and presence of chlorine in some compounds. Each element tested provided higher image contrast than iodine at some tube potential levels. Over the range of tube potentials that are clinically practical for average-sized and larger adults-that is, 100 kVp and higher-barium, gadolinium, ytterbium, and tantalum provided consistently increased image contrast compared with iodine, respectively demonstrating 39%, 56%, 34%, and 24% increases at 100 kVp; 39%, 66%, 53%, and 46% increases at 120 kVp; and 40%, 72%, 65%, and 60% increases at 140 kVp, with no added x-ray filter. The consistently high image contrast produced with 100-140 kVp by tantalum compared with bismuth and iodine at equal mass concentration suggests that tantalum could potentially be favorable for use as a clinical CT contrast agent.

Variability-based active galactic nucleus selection using image subtraction in the SDSS and LSST era

Energy Technology Data Exchange (ETDEWEB)

Choi, Yumi; Gibson, Robert R.; Becker, Andrew C.; Ivezić, Željko; Connolly, Andrew J.; Ruan, John J.; Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); MacLeod, Chelsea L., E-mail: ymchoi@astro.washington.edu [Physics Department, U.S. Naval Academy, 572 Holloway Road, Annapolis, MD 21402 (United States)

2014-02-10

With upcoming all-sky surveys such as LSST poised to generate a deep digital movie of the optical sky, variability-based active galactic nucleus (AGN) selection will enable the construction of highly complete catalogs with minimum contamination. In this study, we generate g-band difference images and construct light curves (LCs) for QSO/AGN candidates listed in Sloan Digital Sky Survey Stripe 82 public catalogs compiled from different methods, including spectroscopy, optical colors, variability, and X-ray detection. Image differencing excels at identifying variable sources embedded in complex or blended emission regions such as Type II AGNs and other low-luminosity AGNs that may be omitted from traditional photometric or spectroscopic catalogs. To separate QSOs/AGNs from other sources using our difference image LCs, we explore several LC statistics and parameterize optical variability by the characteristic damping timescale (τ) and variability amplitude. By virtue of distinguishable variability parameters of AGNs, we are able to select them with high completeness of 93.4% and efficiency (i.e., purity) of 71.3%. Based on optical variability, we also select highly variable blazar candidates, whose infrared colors are consistent with known blazars. One-third of them are also radio detected. With the X-ray selected AGN candidates, we probe the optical variability of X-ray detected optically extended sources using their difference image LCs for the first time. A combination of optical variability and X-ray detection enables us to select various types of host-dominated AGNs. Contrary to the AGN unification model prediction, two Type II AGN candidates (out of six) show detectable variability on long-term timescales like typical Type I AGNs. This study will provide a baseline for future optical variability studies of extended sources.

Active learning of cortical connectivity from two-photon imaging data

Science.gov (United States)

Wang, Ye; Dunson, David; Sapiro, Guillermo; Ringach, Dario

2018-01-01

Understanding how groups of neurons interact within a network is a fundamental question in system neuroscience. Instead of passively observing the ongoing activity of a network, we can typically perturb its activity, either by external sensory stimulation or directly via techniques such as two-photon optogenetics. A natural question is how to use such perturbations to identify the connectivity of the network efficiently. Here we introduce a method to infer sparse connectivity graphs from in-vivo, two-photon imaging of population activity in response to external stimuli. A novel aspect of the work is the introduction of a recommended distribution, incrementally learned from the data, to optimally refine the inferred network. Unlike existing system identification techniques, this “active learning” method automatically focuses its attention on key undiscovered areas of the network, instead of targeting global uncertainty indicators like parameter variance. We show how active learning leads to faster inference while, at the same time, provides confidence intervals for the network parameters. We present simulations on artificial small-world networks to validate the methods and apply the method to real data. Analysis of frequency of motifs recovered show that cortical networks are consistent with a small-world topology model. PMID:29718955

Active learning of cortical connectivity from two-photon imaging data.

Directory of Open Access Journals (Sweden)

Martín A Bertrán

Full Text Available Understanding how groups of neurons interact within a network is a fundamental question in system neuroscience. Instead of passively observing the ongoing activity of a network, we can typically perturb its activity, either by external sensory stimulation or directly via techniques such as two-photon optogenetics. A natural question is how to use such perturbations to identify the connectivity of the network efficiently. Here we introduce a method to infer sparse connectivity graphs from in-vivo, two-photon imaging of population activity in response to external stimuli. A novel aspect of the work is the introduction of a recommended distribution, incrementally learned from the data, to optimally refine the inferred network. Unlike existing system identification techniques, this "active learning" method automatically focuses its attention on key undiscovered areas of the network, instead of targeting global uncertainty indicators like parameter variance. We show how active learning leads to faster inference while, at the same time, provides confidence intervals for the network parameters. We present simulations on artificial small-world networks to validate the methods and apply the method to real data. Analysis of frequency of motifs recovered show that cortical networks are consistent with a small-world topology model.

Framework for a low-cost intra-operative image-guided neuronavigator including brain shift compensation.

Science.gov (United States)

Bucki, M; Lobos, C; Payan, Y

2007-01-01

In this paper we present a methodology to address the problem of brain tissue deformation referred to as 'brain-shift'. This deformation occurs throughout a neurosurgery intervention and strongly alters the accuracy of the neuronavigation systems used to date in clinical routine which rely solely on pre-operative patient imaging to locate the surgical target, such as a tumour or a functional area. After a general description of the framework of our intra-operative image-guided system, we describe a procedure to generate patient specific finite element meshes of the brain and propose a biomechanical model which can take into account tissue deformations and surgical procedures that modify the brain structure, like tumour or tissue resection.

Examining the relationships between body image, eating attitudes, BMI, and physical activity in rural and urban South African young adult females using structural equation modeling.

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Alessandra Prioreschi

Full Text Available The persistence of food insecurity, malnutrition, increasing adiposity, and decreasing physical activity, heightens the need to understand relationships between body image satisfaction, eating attitudes, BMI and physical activity levels in South Africa. Females aged 18-23 years were recruited from rural (n = 509 and urban (n = 510 settings. Body image satisfaction was measured using Stunkard's silhouettes, and the 26-item Eating Attitudes questionnaire (EAT-26 was used to evaluate participants' risk of disordered eating. Minutes per week of moderate to vigorous physical activity (MVPA was assessed using the Global Physical Activity Questionnaire (GPAQ. Significant linear correlates were included in a series of regressions run separately for urban and rural participants. Structural equation modeling (SEM was used to test the relationships between variables. Urban females were more likely to be overweight and obese than rural females (p = 0.02, and had a greater desire to be thinner (p = 0.02. In both groups, being overweight or obese was positively associated with a desire to be thinner (p<0.01, and negatively associated with a desire to be fatter (p<0.01. Having a disordered eating attitude was associated with body image dissatisfaction in the urban group (β = 1.27, p<0.01, CI: 0.38; 2.16, but only with a desire to be fatter in the rural group (β = 0.63, p = 0.04, CI: 0.03; 1.23. In the SEM model, body image dissatisfaction was associated with disordered eating (β = 0.63, as well as higher MVPA participation (p<0.01. These factors were directly associated with a decreased risk of disordered eating attitude, and with a decreased desire to be thinner. Findings indicate a shift in both settings towards more Westernised ideals. Physical activity may provide a means to promote a healthy body image, while reducing the risk of disordered eating. Given the high prevalence of overweight and obesity in both rural and urban women, this study provides

Performance of a novel wafer scale CMOS active pixel sensor for bio-medical imaging

International Nuclear Information System (INIS)

Esposito, M; Evans, P M; Wells, K; Anaxagoras, T; Konstantinidis, A C; Zheng, Y; Speller, R D; Allinson, N M

2014-01-01

Recently CMOS active pixels sensors (APSs) have become a valuable alternative to amorphous silicon and selenium flat panel imagers (FPIs) in bio-medical imaging applications. CMOS APSs can now be scaled up to the standard 20 cm diameter wafer size by means of a reticle stitching block process. However, despite wafer scale CMOS APS being monolithic, sources of non-uniformity of response and regional variations can persist representing a significant challenge for wafer scale sensor response. Non-uniformity of stitched sensors can arise from a number of factors related to the manufacturing process, including variation of amplification, variation between readout components, wafer defects and process variations across the wafer due to manufacturing processes. This paper reports on an investigation into the spatial non-uniformity and regional variations of a wafer scale stitched CMOS APS. For the first time a per-pixel analysis of the electro-optical performance of a wafer CMOS APS is presented, to address inhomogeneity issues arising from the stitching techniques used to manufacture wafer scale sensors. A complete model of the signal generation in the pixel array has been provided and proved capable of accounting for noise and gain variations across the pixel array. This novel analysis leads to readout noise and conversion gain being evaluated at pixel level, stitching block level and in regions of interest, resulting in a coefficient of variation ⩽1.9%. The uniformity of the image quality performance has been further investigated in a typical x-ray application, i.e. mammography, showing a uniformity in terms of CNR among the highest when compared with mammography detectors commonly used in clinical practice. Finally, in order to compare the detection capability of this novel APS with the technology currently used (i.e. FPIs), theoretical evaluation of the detection quantum efficiency (DQE) at zero-frequency has been performed, resulting in a higher DQE for this

Performance of a novel wafer scale CMOS active pixel sensor for bio-medical imaging.

Science.gov (United States)

Esposito, M; Anaxagoras, T; Konstantinidis, A C; Zheng, Y; Speller, R D; Evans, P M; Allinson, N M; Wells, K

2014-07-07

Recently CMOS active pixels sensors (APSs) have become a valuable alternative to amorphous silicon and selenium flat panel imagers (FPIs) in bio-medical imaging applications. CMOS APSs can now be scaled up to the standard 20 cm diameter wafer size by means of a reticle stitching block process. However, despite wafer scale CMOS APS being monolithic, sources of non-uniformity of response and regional variations can persist representing a significant challenge for wafer scale sensor response. Non-uniformity of stitched sensors can arise from a number of factors related to the manufacturing process, including variation of amplification, variation between readout components, wafer defects and process variations across the wafer due to manufacturing processes. This paper reports on an investigation into the spatial non-uniformity and regional variations of a wafer scale stitched CMOS APS. For the first time a per-pixel analysis of the electro-optical performance of a wafer CMOS APS is presented, to address inhomogeneity issues arising from the stitching techniques used to manufacture wafer scale sensors. A complete model of the signal generation in the pixel array has been provided and proved capable of accounting for noise and gain variations across the pixel array. This novel analysis leads to readout noise and conversion gain being evaluated at pixel level, stitching block level and in regions of interest, resulting in a coefficient of variation ⩽1.9%. The uniformity of the image quality performance has been further investigated in a typical x-ray application, i.e. mammography, showing a uniformity in terms of CNR among the highest when compared with mammography detectors commonly used in clinical practice. Finally, in order to compare the detection capability of this novel APS with the technology currently used (i.e. FPIs), theoretical evaluation of the detection quantum efficiency (DQE) at zero-frequency has been performed, resulting in a higher DQE for this

A Single-Transistor Active Pixel CMOS Image Sensor Architecture

International Nuclear Information System (INIS)

Zhang Guo-An; He Jin; Zhang Dong-Wei; Su Yan-Mei; Wang Cheng; Chen Qin; Liang Hai-Lang; Ye Yun

2012-01-01

A single-transistor CMOS active pixel image sensor (1 T CMOS APS) architecture is proposed. By switching the photosensing pinned diode, resetting and selecting can be achieved by diode pull-up and capacitive coupling pull-down of the source follower. Thus, the reset and selected transistors can be removed. In addition, the reset and selected signal lines can be shared to reduce the metal signal line, leading to a very high fill factor. The pixel design and operation principles are discussed in detail. The functionality of the proposed 1T CMOS APS architecture has been experimentally verified using a fabricated chip in a standard 0.35 μm CMOS AMIS technology

FDG-PET imaging of lower extremity muscular activity during level walking

International Nuclear Information System (INIS)

Oi, Naoyuki; Iwaya, Tsutomu; Tobimatsu, Yoshiko; Fujimoto, Toshihiko; Itoh, Masatoshi; Yamaguchi, Keiichiro

2003-01-01

We analyzed muscular activity of the lower extremities during level walking using positron emission tomography (PET) with 18 F-fluorodeoxyglucose ( 18 F-FDG). We examined 17 healthy male subjects; 11 were assigned to a walking group and 6 to a resting group. After 18 F-FDG injection, the walking group subjects walked at a free speed for 15 min. A whole-body image was then obtained by a PET camera, and the standardized uptake ratio (SUR) was computed for each muscle. The SUR for each muscle of the walking group was compared with that for the corresponding muscles in the resting group. The level of muscular activity of all the muscles we examined were higher during level walking than when resting. The activity of the lower leg muscles was higher than that of the thigh muscles during level walking. The muscular activity of the soleus was highest among all the muscles examined. Among the gluteal muscles, the muscular activity of the gluteus minimus was higher than that of the gluteus maximus and gluteus medius. The concurrent validity of measuring muscular activity of the lower extremity during level walking by the PET method using 18 F-FDG was demonstrated. (author)

IMAGE DESCRIPTIONS FOR SKETCH BASED IMAGE RETRIEVAL

OpenAIRE

SAAVEDRA RONDO, JOSE MANUEL; SAAVEDRA RONDO, JOSE MANUEL

2008-01-01

Due to the massive use of Internet together with the proliferation of media devices, content based image retrieval has become an active discipline in computer science. A common content based image retrieval approach requires that the user gives a regular image (e.g, a photo) as a query. However, having a regular image as query may be a serious problem. Indeed, people commonly use an image retrieval system because they do not count on the desired image. An easy alternative way t...

Functional Neuro-Imaging and Post-Traumatic Olfactory Impairment

Science.gov (United States)

Roberts, Richard J.; Sheehan, William; Thurber, Steven; Roberts, Mary Ann

2010-01-01

Objective: To evaluate via a research literature survey the anterior neurological significance of decreased olfactory functioning following traumatic brain injuries. Materials and Methods: A computer literature review was performed to locate all functional neuro-imaging studies on patients with post-traumatic anosmia and other olfactory deficits. Results: A convergence of findings from nine functional neuro-imaging studies indicating evidence for reduced metabolic activity at rest or relative hypo-perfusion during olfactory activations. Hypo-activation of the prefrontal regions was apparent in all nine post-traumatic samples, with three samples yielding evidence of reduced activity in the temporal regions as well. Conclusions: The practical ramifications include the reasonable hypothesis that a total anosmic head trauma patient likely has frontal lobe involvement. PMID:21716782

45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

Science.gov (United States)

2010-10-01

... assessments, job creation and economic development activities? 287.130 Section 287.130 Public Welfare... creation and economic development activities? (a) A Tribe may conduct job market assessments within its NEW Program. These might include the following: (1) Consultation with the Tribe's economic development staff...

Predicting Pathological Features at Radical Prostatectomy in Patients with Prostate Cancer Eligible for Active Surveillance by Multiparametric Magnetic Resonance Imaging.

Directory of Open Access Journals (Sweden)

Ottavio de Cobelli

Full Text Available The aim of this study was to investigate the prognostic performance of multiparametric magnetic resonance imaging (mpMRI and Prostate Imaging Reporting and Data System (PIRADS score in predicting pathologic features in a cohort of patients eligible for active surveillance who underwent radical prostatectomy.A total of 223 patients who fulfilled the criteria for "Prostate Cancer Research International: Active Surveillance", were included. Mp-1.5 Tesla MRI examination staging with endorectal coil was performed at least 6-8 weeks after TRUS-guided biopsy. In all patients, the likelihood of the presence of cancer was assigned using PIRADS score between 1 and 5. Outcomes of interest were: Gleason score upgrading, extra capsular extension (ECE, unfavorable prognosis (occurrence of both upgrading and ECE, large tumor volume (≥ 0.5 ml, and seminal vesicle invasion (SVI. Receiver Operating Characteristic (ROC curves and Decision Curve Analyses (DCA were performed for models with and without inclusion of PIRADS score.Multivariate analysis demonstrated the association of PIRADS score with upgrading (P < 0.0001, ECE (P < 0.0001, unfavorable prognosis (P < 0.0001, and large tumor volume (P = 0.002. ROC curves and DCA showed that models including PIRADS score resulted in greater net benefit for almost all the outcomes of interest, with the only exception of SVI.mpMRI and PIRADS scoring are feasible tools in clinical setting and could be used as decision-support systems for a more accurate selection of patients eligible for AS.

scikit-image: image processing in Python.

Science.gov (United States)

van der Walt, Stéfan; Schönberger, Johannes L; Nunez-Iglesias, Juan; Boulogne, François; Warner, Joshua D; Yager, Neil; Gouillart, Emmanuelle; Yu, Tony

2014-01-01

scikit-image is an image processing library that implements algorithms and utilities for use in research, education and industry applications. It is released under the liberal Modified BSD open source license, provides a well-documented API in the Python programming language, and is developed by an active, international team of collaborators. In this paper we highlight the advantages of open source to achieve the goals of the scikit-image library, and we showcase several real-world image processing applications that use scikit-image. More information can be found on the project homepage, http://scikit-image.org.

scikit-image: image processing in Python

Directory of Open Access Journals (Sweden)

Stéfan van der Walt

2014-06-01

Full Text Available scikit-image is an image processing library that implements algorithms and utilities for use in research, education and industry applications. It is released under the liberal Modified BSD open source license, provides a well-documented API in the Python programming language, and is developed by an active, international team of collaborators. In this paper we highlight the advantages of open source to achieve the goals of the scikit-image library, and we showcase several real-world image processing applications that use scikit-image. More information can be found on the project homepage, http://scikit-image.org.

Acute opioid withdrawal is associated with increased neural activity in reward-processing centers in healthy men: A functional magnetic resonance imaging study.

Science.gov (United States)

Chu, Larry F; Lin, Joanne C; Clemenson, Anna; Encisco, Ellen; Sun, John; Hoang, Dan; Alva, Heather; Erlendson, Matthew; Clark, J David; Younger, Jarred W

2015-08-01

Opioid analgesics are frequently prescribed for chronic pain. One expected consequence of long-term opioid use is the development of physical dependence. Although previous resting state functional magnetic resonance imaging (fMRI) studies have demonstrated signal changes in reward-associated areas following morphine administration, the effects of acute withdrawal on the human brain have been less well-investigated. In an earlier study by our laboratory, ondansetron was shown to be effective in preventing symptoms associated with opioid withdrawal. The purpose of this current study was to characterize neural activity associated with acute opioid withdrawal and examine whether these changes are modified by ondansetron. Ten participants were enrolled in this placebo-controlled, randomized, double-blind, crossover study and attended three acute opioid withdrawal sessions. Participants received either placebo or ondansetron (8Ymg IV) before morphine administration (10Ymg/70Ykg IV). Participants then underwent acute naloxone-precipitated withdrawal during a resting state fMRI scan. Objective and subjective opioid withdrawal symptoms were assessed. Imaging results showed that naloxone-precipitated opioid withdrawal was associated with increased neural activity in several reward processing regions, including the right pregenual cingulate, putamen, and bilateral caudate, and decreased neural activity in networks involved in sensorimotor integration. Ondansetron pretreatment did not have a significant effect on the imaging correlates of opioid withdrawal. This study presents a preliminary investigation of the regional changes in neural activity during acute opioid withdrawal. The fMRI acute opioid withdrawal model may serve as a tool for studying opioid dependence and withdrawal in human participants. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Translocator protein as an imaging marker of macrophage and stromal activation in RA pannus.

Science.gov (United States)

Narayan, Nehal; Owen, David; Mandhair, Harpreet; Smyth, Erica; Carlucci, Francesco; Saleem, Azeem; Gunn, Roger; Rabiner, Eugenii Ilan A; Wells, Lisa; Dakin, Stephanie; Sabokbar, Afsie; Taylor, Peter

2018-01-04

Positron Emission Tomography (PET) radioligands targeted to Translocator protein (TSPO), offer a highly sensitive and specific means of imaging joint inflammation in rheumatoid arthritis (RA). Through high expression of TSPO on activated macrophages, TSPO PET has been widely reported in several studies of RA as a means of imaging synovial macrophages in vivo. However, this premise does not take into account the ubiquitous expression of TSPO. This study aimed to investigate TSPO expression in major cellular constituents of RA pannus; monocytes, macrophages, fibroblast-like synoviocytes (FLS) and CD4+ T lymphocytes, to more accurately interpret TSPO PET signal from RA synovium. Methods: 3 RA patients and 3 healthy volunteers underwent PET both knees using the TSPO radioligand 11 C-PBR28. Through synovial tissue 3H-PBR28 autoradiography and immunostaining of 6 RA patients and 6 healthy volunteers, cellular expression of TSPO in synovial tissue was evaluated. TSPO mRNA expression and 3H-PBR28 radioligand binding was assessed using in vitro monocytes, macrophages, FLS and CD4+ T-lymphocytes. Results: 11 C-PBR28 PET signal was significantly higher in RA compared to healthy joints (average SUV 0.82± 0.12 compared to 0.03± 0.004 respectively, p<0.01). Further, 3H-PBR28 specific binding in synovial tissue was approximately 10-fold higher in RA compared to healthy controls. Immunofluorescence revealed TSPO expression on macrophages, FLS and CD4+ T cells. In vitro study demonstrated highest TSPO mRNA expression and 3H-PBR28 specific binding, in activated FLS, non-activated and activated 'M2' reparative macrophages, with least TSPO expression in activated and non-activated CD4+ T lymphocytes. Conclusion: This study is the first evaluation of cellular TSPO expression in synovium, finding highest TSPO expression and PBR28 binding on activated synovial FLS and M2 phenotype macrophages. TSPO targeted PET may therefore have unique sensitivity to detect FLS and macrophage

Assessment of chitosan-affected metabolic response by peroxisome proliferator-activated receptor bioluminescent imaging-guided transcriptomic analysis.

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Chia-Hung Kao

Full Text Available Chitosan has been widely used in food industry as a weight-loss aid and a cholesterol-lowering agent. Previous studies have shown that chitosan affects metabolic responses and contributes to anti-diabetic, hypocholesteremic, and blood glucose-lowering effects; however, the in vivo targeting sites and mechanisms of chitosan remain to be clarified. In this study, we constructed transgenic mice, which carried the luciferase genes driven by peroxisome proliferator-activated receptor (PPAR, a key regulator of fatty acid and glucose metabolism. Bioluminescent imaging of PPAR transgenic mice was applied to report the organs that chitosan acted on, and gene expression profiles of chitosan-targeted organs were further analyzed to elucidate the mechanisms of chitosan. Bioluminescent imaging showed that constitutive PPAR activities were detected in brain and gastrointestinal tract. Administration of chitosan significantly activated the PPAR activities in brain and stomach. Microarray analysis of brain and stomach showed that several pathways involved in lipid and glucose metabolism were regulated by chitosan. Moreover, the expression levels of metabolism-associated genes like apolipoprotein B (apoB and ghrelin genes were down-regulated by chitosan. In conclusion, these findings suggested the feasibility of PPAR bioluminescent imaging-guided transcriptomic analysis on the evaluation of chitosan-affected metabolic responses in vivo. Moreover, we newly identified that downregulated expression of apoB and ghrelin genes were novel mechanisms for chitosan-affected metabolic responses in vivo.

Evaluation of the Effect of Fingolimod Treatment on Microglial Activation Using Serial PET Imaging in Multiple Sclerosis.

Science.gov (United States)

Sucksdorff, Marcus; Rissanen, Eero; Tuisku, Jouni; Nuutinen, Salla; Paavilainen, Teemu; Rokka, Johanna; Rinne, Juha; Airas, Laura

2017-10-01

Traditionally, multiple sclerosis (MS) has been considered a white matter disease with focal inflammatory lesions. It is, however, becoming clear that significant pathology, such as microglial activation, also takes place outside the plaque areas, that is, in areas of normal-appearing white matter (NAWM) and gray matter (GM). Microglial activation can be detected in vivo using 18-kDa translocator protein (TSPO)-binding radioligands and PET. It is unknown whether fingolimod affects microglial activation in MS. The aim of this study was to investigate whether serial PET can be used to evaluate the effect of fingolimod treatment on microglial activation. Methods: Ten relapsing-remitting MS patients were studied using the TSPO radioligand 11 C-( R )-PK11195. Imaging was performed at baseline and after 8 and 24 wk of fingolimod treatment. Eight healthy individuals were imaged for comparison. Microglial activation was evaluated as distribution volume ratio of 11 C-( R )-PK11195. Results: The patients had MS for an average of 7.9 ± 4.3 y (mean ± SD), their total relapses averaged 4 ± 2.4, and their Expanded Disability Status Scale was 2.7 ± 0.5. The patients were switched to fingolimod because of safety reasons or therapy escalation. The mean washout period before the initiation of fingolimod was 2.3 ± 1.1 mo. The patients were clinically stable on fingolimod. At baseline, microglial activation was significantly higher in the combined NAWM and GM areas of MS patients than in healthy controls ( P = 0.021). 11 C-( R )-PK11195 binding was reduced (-12.31%) within the combined T2 lesion area after 6 mo of fingolimod treatment ( P = 0.040) but not in the areas of NAWM or GM. Conclusion: Fingolimod treatment reduced microglial/macrophage activation at the site of focal inflammatory lesions, presumably by preventing leukocyte trafficking from the periphery. It did not affect the widespread, diffuse microglial activation in the NAWM and GM. The study opens new vistas for

Generic and robust method for automatic segmentation of PET images using an active contour model

Energy Technology Data Exchange (ETDEWEB)

Zhuang, Mingzan [Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, 9700 RB Groningen (Netherlands)

2016-08-15

Purpose: Although positron emission tomography (PET) images have shown potential to improve the accuracy of targeting in radiation therapy planning and assessment of response to treatment, the boundaries of tumors are not easily distinguishable from surrounding normal tissue owing to the low spatial resolution and inherent noisy characteristics of PET images. The objective of this study is to develop a generic and robust method for automatic delineation of tumor volumes using an active contour model and to evaluate its performance using phantom and clinical studies. Methods: MASAC, a method for automatic segmentation using an active contour model, incorporates the histogram fuzzy C-means clustering, and localized and textural information to constrain the active contour to detect boundaries in an accurate and robust manner. Moreover, the lattice Boltzmann method is used as an alternative approach for solving the level set equation to make it faster and suitable for parallel programming. Twenty simulated phantom studies and 16 clinical studies, including six cases of pharyngolaryngeal squamous cell carcinoma and ten cases of nonsmall cell lung cancer, were included to evaluate its performance. Besides, the proposed method was also compared with the contourlet-based active contour algorithm (CAC) and Schaefer’s thresholding method (ST). The relative volume error (RE), Dice similarity coefficient (DSC), and classification error (CE) metrics were used to analyze the results quantitatively. Results: For the simulated phantom studies (PSs), MASAC and CAC provide similar segmentations of the different lesions, while ST fails to achieve reliable results. For the clinical datasets (2 cases with connected high-uptake regions excluded) (CSs), CAC provides for the lowest mean RE (−8.38% ± 27.49%), while MASAC achieves the best mean DSC (0.71 ± 0.09) and mean CE (53.92% ± 12.65%), respectively. MASAC could reliably quantify different types of lesions assessed in this work

A study on the activation of supplementary motor area in functional magnetic resonance imaging of the brain

International Nuclear Information System (INIS)

Jin, Gong Yong; Chung, Gyung Ho; Park, Hark Hoon; Oh, Hee Sul; Kim, Chong Soo; Chung, Jin Young

1999-01-01

To evaluate the activated zone of the supplementary motor area through motor and sensory stimulation of both hands by fMRI. Twenty-four healthy volunteers, ranging in age from 20 to 30 years, served as subjects. They were divided into four groups and performed one of the four activation tasks : complex movement, fine movement, touch sensation, heat sensation. Complex movement consisted of a finger task in which subjects flexed and extended all fingers repeatedly in union, without the fingers touching each other(group I). Fine movement involved a thumb task in which subjects flexed and extended the thumb repeatedly without touching the other fingers(group II). Touch sensation consisted of a palm task in which another person repeatedly drew a circle on the subject's palm (group III), and heat sensation involved of a palm task in which subject's palm was touched by another person with a 40 deg C water-bag (group IV). F-MRI was conducted on a commercial 1.5-T scanner equipped with echo-planar imaging. After overlapping images were obtained using a Z-s-core, and the mean/curve in the MR devices was evaluated, the activated zone of the supplementary motor area was also evalvated. Thirty-two of 48 images(20 of the 24 men) revealed activated zones in the supplementary motor area. In group I, activation was observed in five subjects, in three of whom it was bilateral (contralateral activation). In group II, activation was observed in five subjects, in one of whom it was bilateral. In group III, activation occurred in five subjects(bilateral in four, and contralateral in three), and In group IV, activation was also observed in five;in three of these it was bilateral. Using fMRI, and in association with motor and sensory tasks, the supplementary motor area was activated in 66.7% of healthy volunteers (32/48)

In Vivo Metabolic Trapping Radiotracers for Imaging Monoamine Oxidase-A and –B Enzymatic Activity

Science.gov (United States)

Brooks, Allen F.; Shao, Xia; Quesada, Carole A.; Sherman, Phillip; Scott, Peter J.H.; Kilbourn, Michael R.

2017-01-01

The isozymes of monoamine oxidase (MAO-A and MAO-B) are important enzymes involved in the metabolism of numerous biogenic amines, including the neurotransmitters serotonin, dopamine and norepinephrine. Recently, changes in concentrations of MAO-B have been proposed as an in vivo marker of neuroinflammation associated with Alzheimer’s disease. Previous developments of in vivo radiotracers for imaging changes in MAO enzyme expression or activity have utilized the irreversible propargylamine-based suicide inhibitors, or high-affinity reversibly-binding inhibitors. As an alternative approach, we have investigated 1-[11C]methyl-4-aryloxy-1,2,3,6-tetrahydropyridines as metabolic trapping agents for the monoamine oxidases. MAO-mediated oxidation and spontaneous hydrolysis yields 1-[11C]methyl-2,3-dihydro-4-pyridinone as a hydrophilic metabolite that is trapped within brain tissues. Radiotracers with phenyl, biphenyl and 7-coumarinyl ethers were evaluated using microPET imaging in rat and primate brain. No isozyme selectivity for radiotracer trapping was observed in the rat brain for any compound, but in the monkey brain the phenyl ether demonstrated MAO-A selectivity, and the coumarinyl ether showed MAO-B selectivity. These are lead compounds for further development of 1-[11C]methyl-4-aryloxy-1,2,3,6-tetrahydropyridines with optimized brain pharmacokinetics and isozyme selectivity. PMID:26393369

Association between Body Image Dissatisfaction and Self-Rated Health, as Mediated by Physical Activity and Eating Habits: Structural Equation Modelling in ELSA-Brasil.

Science.gov (United States)

de Oliveira da Silva, Patricia; Miguez Nery Guimarães, Joanna; Härter Griep, Rosane; Caetano Prates Melo, Enirtes; Maria Alvim Matos, Sheila; Del Carmem Molina, Maria; Maria Barreto, Sandhi; de Jesus Mendes da Fonseca, Maria

2018-04-18

This study investigated whether the association between body image dissatisfaction and poor self-rated health is mediated by insufficient physical activity and unhealthy eating habits. The participants were 6727 men and 8037 women from the baseline (2008–2010) of the Longitudinal Study of Adult Health (Estudo Longitudinal de Saúde do Adulto, ELSA-Brasil). Structural equation modelling was used. Associations were found between body image dissatisfaction and poor self-rated health in both sexes. Insufficient physical activity was a mediator. However, unhealthy eating habits were found to exert a mediator effect only via insufficient physical activity. Body image dissatisfaction was found to associate, both directly and possibly indirectly, with poor self-rated health, mediated by insufficient physical activity and unhealthy eating habits. Accordingly, encouraging physical activity and healthy eating can contribute to reducing body image dissatisfaction and favour better self-rated health.

The evolution of colour polymorphism in British winter-active Lepidoptera in response to search image use by avian predators.

Science.gov (United States)

Weir, Jamie Conor

2018-05-10

Phenotypic polymorphism in cryptic species is widespread. This may evolve in response to search image use by predators exerting negative frequency-dependent selection on intraspecific colour morphs, "apostatic selection". Evidence exists to indicate search image formation by predators and apostatic selection operating on wild prey populations, though not to demonstrate search image use directly resulting in apostatic selection. The present study attempted to address this deficiency, using British Lepidoptera active in winter as a model system. It has been proposed that the typically polymorphic wing colouration of these species represents an anti-search image adaptation against birds. To test (a) for search image driven apostatic selection, dimorphic populations of artificial moth-like models were established in woodland at varying relative morph frequencies and exposed to predation by natural populations of birds. In addition, to test (b) whether abundance and degree of polymorphism are correlated across British winter-active moths, as predicted where search image use drives apostatic selection, a series of phylogenetic comparative analyses were conducted. There was a positive relationship between artificial morph frequency and probability of predation, consistent with birds utilising search images and exerting apostatic selection. Abundance and degree of polymorphism were found to be positively correlated across British Lepidoptera active in winter, though not across all taxonomic groups analysed. This evidence is consistent with polymorphism in this group having evolved in response to search image driven apostatic selection and supports the viability of this mechanism as a means by which phenotypic and genetic variation may be maintained in natural populations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Advances in low-level color image processing

CERN Document Server

Smolka, Bogdan

2014-01-01

Color perception plays an important role in object recognition and scene understanding both for humans and intelligent vision systems. Recent advances in digital color imaging and computer hardware technology have led to an explosion in the use of color images in a variety of applications including medical imaging, content-based image retrieval, biometrics, watermarking, digital inpainting, remote sensing, visual quality inspection, among many others. As a result, automated processing and analysis of color images has become an active area of research, to which the large number of publications of the past two decades bears witness. The multivariate nature of color image data presents new challenges for researchers and practitioners as the numerous methods developed for single channel images are often not directly applicable to multichannel  ones. The goal of this volume is to summarize the state-of-the-art in the early stages of the color image processing pipeline.

Imaging and Screening of Kidney Cancer.

Science.gov (United States)

Diaz de Leon, Alberto; Pedrosa, Ivan

2017-11-01

Renal cell carcinoma (RCC) exhibits a diverse and heterogeneous disease spectrum, but insight into its molecular biology has provided an improved understanding of potential risk factors, oncologic behavior, and imaging features. Computed tomography (CT) and MR imaging may allow the identification and preoperative subtyping of RCC and assessment of a response to various therapies. Active surveillance is a viable management option in some patients and has provided further insight into the natural history of RCC, including the favorable prognosis of cystic neoplasms. This article reviews CT and MR imaging in RCC and the role of screening in selected high-risk populations. Copyright © 2017 Elsevier Inc. All rights reserved.

The Black Hole Mass-Bulge Luminosity Relationship for Active Galactic Nuclei From Reverberation Mapping and Hubble Space Telescope Imaging

DEFF Research Database (Denmark)

Bentz, Misty C.; Peterson, Bradley M.; Pogge, Richard W.

2009-01-01

We investigate the relationship between black hole mass and bulge luminosity for active galactic nuclei (AGNs) with reverberation-based black hole mass measurements and bulge luminosities from two-dimensional decompositions of Hubble Space Telescope host galaxy images. We find that the slope...... of the relationship for AGNs is 0.76-0.85 with an uncertainty of ~0.1, somewhat shallower than the M BH vprop L 1.0±0.1 relationship that has been fit to nearby quiescent galaxies with dynamical black hole mass measurements. This difference is somewhat perplexing, as the AGN black hole masses include an overall...

On two methods of statistical image analysis

NARCIS (Netherlands)

Missimer, J; Knorr, U; Maguire, RP; Herzog, H; Seitz, RJ; Tellman, L; Leenders, K.L.

1999-01-01

The computerized brain atlas (CBA) and statistical parametric mapping (SPM) are two procedures for voxel-based statistical evaluation of PET activation studies. Each includes spatial standardization of image volumes, computation of a statistic, and evaluation of its significance. In addition,

Reflective and Non-conscious Responses to Exercise Images.

Science.gov (United States)

Cope, Kathryn; Vandelanotte, Corneel; Short, Camille E; Conroy, David E; Rhodes, Ryan E; Jackson, Ben; Dimmock, James A; Rebar, Amanda L

2017-01-01

Images portraying exercise are commonly used to promote exercise behavior and to measure automatic associations of exercise (e.g., via implicit association tests). The effectiveness of these promotion efforts and the validity of measurement techniques partially rely on the untested assumption that the images being used are perceived by the general public as portrayals of exercise that is pleasant and motivating. The aim of this study was to investigate how content of images impacted people's automatic and reflective evaluations of exercise images. Participants ( N = 90) completed a response time categorization task (similar to the implicit association test) to capture how automatically people perceived each image as relevant to Exercise or Not exercise . Participants also self-reported their evaluations of the images using visual analog scales with the anchors: Exercise / Not exercise, Does not motivate me to exercise / Motivates me to exercise, Pleasant / Unpleasant , and Energizing/Deactivating . People tended to more strongly automatically associate images with exercise if the images were of an outdoor setting, presented sport (as opposed to active labor or gym-based) activities, and included young (as opposed to middle-aged) adults. People tended to reflectively find images of young adults more motivating and relevant to exercise than images of older adults. The content of exercise images is an often overlooked source of systematic variability that may impact measurement validity and intervention effectiveness.

Reflective and Non-conscious Responses to Exercise Images

Directory of Open Access Journals (Sweden)

Kathryn Cope

2018-01-01

Full Text Available Images portraying exercise are commonly used to promote exercise behavior and to measure automatic associations of exercise (e.g., via implicit association tests. The effectiveness of these promotion efforts and the validity of measurement techniques partially rely on the untested assumption that the images being used are perceived by the general public as portrayals of exercise that is pleasant and motivating. The aim of this study was to investigate how content of images impacted people's automatic and reflective evaluations of exercise images. Participants (N = 90 completed a response time categorization task (similar to the implicit association test to capture how automatically people perceived each image as relevant to Exercise or Not exercise. Participants also self-reported their evaluations of the images using visual analog scales with the anchors: Exercise/Not exercise, Does not motivate me to exercise/Motivates me to exercise, Pleasant/Unpleasant, and Energizing/Deactivating. People tended to more strongly automatically associate images with exercise if the images were of an outdoor setting, presented sport (as opposed to active labor or gym-based activities, and included young (as opposed to middle-aged adults. People tended to reflectively find images of young adults more motivating and relevant to exercise than images of older adults. The content of exercise images is an often overlooked source of systematic variability that may impact measurement validity and intervention effectiveness.

Statistical region based active contour using a fractional entropy descriptor: Application to nuclei cell segmentation in confocal \\ud microscopy images

OpenAIRE

Histace, A; Meziou, B J; Matuszewski, Bogdan; Precioso, F; Murphy, M F; Carreiras, F

2013-01-01

We propose an unsupervised statistical region based active contour approach integrating an original fractional entropy measure for image segmentation with a particular application to single channel actin tagged fluorescence confocal microscopy image segmentation. Following description of statistical based active contour segmentation and the mathematical definition of the proposed fractional entropy descriptor, we demonstrate comparative segmentation results between the proposed approach and s...

Managing nuclear knowledge: IAEA activities and international coordination. Including resource material full text CD-ROM

International Nuclear Information System (INIS)

2005-06-01

The present CD-ROM summarizes some activities carried out by the Departments of Nuclear Energy and Nuclear Safety and Security in the area of nuclear knowledge management in the period 2003-2005. It comprises, as open resource, most of the relevant documents in full text, including policy level documents, reports, presentation material by Member States and meeting summaries. The collection starts with a reprint of the report to the IAEA General Conference 2004 on Nuclear Knowledge [GOV/2004/56-GC(48)/12] summarizing the developments in nuclear knowledge management since the 47th session of the General Conference in 2003 and covers Managing Nuclear Knowledge including safety issues and Information and Strengthening Education and Training for Capacity Building. It contains an excerpt on Nuclear Knowledge from the General Conference Resolution [GC(48)/RES/13] on Strengthening the Agency's Activities Related to Nuclear Science, Technology and Applications. On the CD-ROM itself, all documents can easily be accessed by clicking on their titles on the subject pages (also printed at the end of this Working Material). Part 1 of the CD-ROM covers the activities in the period 2003-2005 and part 2 presents a resource material full text CD-ROM on Managing Nuclear Knowledge issued in October 2003

In-vitro and in-vivo imaging of MMP activity in cartilage and joint injury

International Nuclear Information System (INIS)

Fukui, Tomoaki; Tenborg, Elizabeth; Yik, Jasper H.N.; Haudenschild, Dominik R.

2015-01-01

Non-destructive detection of cartilage-degrading activities represents an advance in osteoarthritis (OA) research, with implications in studies of OA pathogenesis, progression, and intervention strategies. Matrix metalloproteinases (MMPs) are principal cartilage degrading enzymes that contribute to OA pathogenesis. MMPSense750 is an in-vivo fluorimetric imaging probe with the potential to continuously and non-invasively trace real-time MMP activities, but its use in OA-related research has not been reported. Our objective is to detect and characterize the early degradation activities shortly after cartilage or joint injury with MMPSense750. We determined the appropriate concentration, assay time, and linear range using various concentrations of recombinant MMPs as standards. We then quantified MMP activity from cartilage explants subjected to either mechanical injury or inflammatory cytokine treatment in-vitro. Finally, we performed in-vivo MMP imaging of a mouse model of post-traumatic OA. Our in-vitro results showed that the optimal assay time was highly dependent on the MMP enzyme. In cartilage explant culture media, mechanical impact or cytokine treatment increased MMP activity. Injured knees of mice showed significantly higher fluorescent signal than uninjured knees. We conclude that MMPSense750 detects human MMP activities and can be used for in-vitro study with cartilage, as well as in-vivo studies of knee injury, and can offering real-time insight into the degradative processes that occurring within the joint before structural changes become evident radiographically. - Highlights: • MMPSense750 is near-infrared fluorescent probe which can detect MMP activity. • MMPSense750 can detect human MMP-3, -9, and -13. • The reaction kinetics with MMPSense750 were different for the three MMPs. • MMPSense750 can visualized real time MMP activity in mouse injured knees. • MMPSense750 is convenient tool to evaluate real-time MMP activity non-invasively

In-vitro and in-vivo imaging of MMP activity in cartilage and joint injury

Energy Technology Data Exchange (ETDEWEB)

Fukui, Tomoaki; Tenborg, Elizabeth; Yik, Jasper H.N.; Haudenschild, Dominik R., E-mail: DRHaudenschild@ucdavis.edu

2015-05-08

Non-destructive detection of cartilage-degrading activities represents an advance in osteoarthritis (OA) research, with implications in studies of OA pathogenesis, progression, and intervention strategies. Matrix metalloproteinases (MMPs) are principal cartilage degrading enzymes that contribute to OA pathogenesis. MMPSense750 is an in-vivo fluorimetric imaging probe with the potential to continuously and non-invasively trace real-time MMP activities, but its use in OA-related research has not been reported. Our objective is to detect and characterize the early degradation activities shortly after cartilage or joint injury with MMPSense750. We determined the appropriate concentration, assay time, and linear range using various concentrations of recombinant MMPs as standards. We then quantified MMP activity from cartilage explants subjected to either mechanical injury or inflammatory cytokine treatment in-vitro. Finally, we performed in-vivo MMP imaging of a mouse model of post-traumatic OA. Our in-vitro results showed that the optimal assay time was highly dependent on the MMP enzyme. In cartilage explant culture media, mechanical impact or cytokine treatment increased MMP activity. Injured knees of mice showed significantly higher fluorescent signal than uninjured knees. We conclude that MMPSense750 detects human MMP activities and can be used for in-vitro study with cartilage, as well as in-vivo studies of knee injury, and can offering real-time insight into the degradative processes that occurring within the joint before structural changes become evident radiographically. - Highlights: • MMPSense750 is near-infrared fluorescent probe which can detect MMP activity. • MMPSense750 can detect human MMP-3, -9, and -13. • The reaction kinetics with MMPSense750 were different for the three MMPs. • MMPSense750 can visualized real time MMP activity in mouse injured knees. • MMPSense750 is convenient tool to evaluate real-time MMP activity non-invasively.

Different patterns of auditory cortex activation revealed by functional magnetic resonance imaging

International Nuclear Information System (INIS)

Formisano, E.; Pepino, A.; Bracale, M.; Di Salle, F.; Lanfermann, H.; Zanella, F.E.

1998-01-01

In the last few years, functional Magnetic Resonance Imaging (fMRI) has been widely accepted as an effective tool for mapping brain activities in both the sensorimotor and the cognitive field. The present work aims to assess the possibility of using fMRI methods to study the cortical response to different acoustic stimuli. Furthermore, we refer to recent data collected at Frankfurt University on the cortical pattern of auditory hallucinations. Healthy subjects showed broad bilateral activation, mostly located in the transverse gyrus of Heschl. The analysis of the cortical activation induced by different stimuli has pointed out a remarkable difference in the spatial and temporal features of the auditory cortex response to pulsed tones and pure tones. The activated areas during episodes of auditory hallucinations match the location of primary auditory cortex as defined in control measurements with the same patients and in the experiments on healthy subjects. (authors)

Monitoring Active Volcanos Using Aerial Images and the Orthoview Tool

Directory of Open Access Journals (Sweden)

Maria Marsella

2014-12-01

Full Text Available In volcanic areas, where it can be difficult to perform direct surveys, digital photogrammetry techniques are rarely adopted for routine volcano monitoring. Nevertheless, they have remarkable potentialities for observing active volcanic features (e.g., fissures, lava flows and the connected deformation processes. The ability to obtain accurate quantitative data of definite accuracy in short time spans makes digital photogrammetry a suitable method for controlling the evolution of rapidly changing large-area volcanic phenomena. The systematic acquisition of airborne photogrammetric datasets can be adopted for implementing a more effective procedure aimed at long-term volcano monitoring and hazard assessment. In addition, during the volcanic crisis, the frequent acquisition of oblique digital images from helicopter allows for quasi-real-time monitoring to support mitigation actions by civil protection. These images are commonly used to update existing maps through a photo-interpretation approach that provide data of unknown accuracy. This work presents a scientific tool (Orthoview that implements a straightforward photogrammetric approach to generate digital orthophotos from single-view oblique images provided that at least four Ground Control Points (GCP and current Digital Elevation Models (DEM are available. The influence of the view geometry, of sparse and not-signalized GCP and DEM inaccuracies is analyzed for evaluating the performance of the developed tool in comparison with other remote sensing techniques. Results obtained with datasets from Etna and Stromboli volcanoes demonstrate that 2D features measured on the produced orthophotos can reach sub-meter-level accuracy.

Optimization of a GCaMP calcium indicator for neural activity imaging.

Science.gov (United States)

Akerboom, Jasper; Chen, Tsai-Wen; Wardill, Trevor J; Tian, Lin; Marvin, Jonathan S; Mutlu, Sevinç; Calderón, Nicole Carreras; Esposti, Federico; Borghuis, Bart G; Sun, Xiaonan Richard; Gordus, Andrew; Orger, Michael B; Portugues, Ruben; Engert, Florian; Macklin, John J; Filosa, Alessandro; Aggarwal, Aman; Kerr, Rex A; Takagi, Ryousuke; Kracun, Sebastian; Shigetomi, Eiji; Khakh, Baljit S; Baier, Herwig; Lagnado, Leon; Wang, Samuel S-H; Bargmann, Cornelia I; Kimmel, Bruce E; Jayaraman, Vivek; Svoboda, Karel; Kim, Douglas S; Schreiter, Eric R; Looger, Loren L

2012-10-03

Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Recent efforts in protein engineering have significantly increased the performance of GECIs. The state-of-the art single-wavelength GECI, GCaMP3, has been deployed in a number of model organisms and can reliably detect three or more action potentials in short bursts in several systems in vivo. Through protein structure determination, targeted mutagenesis, high-throughput screening, and a battery of in vitro assays, we have increased the dynamic range of GCaMP3 by severalfold, creating a family of "GCaMP5" sensors. We tested GCaMP5s in several systems: cultured neurons and astrocytes, mouse retina, and in vivo in Caenorhabditis chemosensory neurons, Drosophila larval neuromuscular junction and adult antennal lobe, zebrafish retina and tectum, and mouse visual cortex. Signal-to-noise ratio was improved by at least 2- to 3-fold. In the visual cortex, two GCaMP5 variants detected twice as many visual stimulus-responsive cells as GCaMP3. By combining in vivo imaging with electrophysiology we show that GCaMP5 fluorescence provides a more reliable measure of neuronal activity than its predecessor GCaMP3. GCaMP5 allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general.

Bioorthogonal Chemical Imaging for Biomedicine

Science.gov (United States)

Min, Wei

2017-06-01

Innovations in light microscopy have tremendously revolutionized the way researchers study biological systems with subcellular resolution. Although fluorescence microscopy is currently the method of choice for cellular imaging, it faces fundamental limitations for studying the vast number of small biomolecules. This is because relatively bulky fluorescent labels could introduce considerable perturbation to or even completely alter the native functions of vital small biomolecules. Hence, despite their immense functional importance, these small biomolecules remain largely undetectable by fluorescence microscopy. To address this challenge, we have developed a bioorthogonal chemical imaging platform. By coupling stimulated Raman scattering (SRS) microscopy, an emerging nonlinear Raman microscopy technique, with tiny and Raman-active vibrational probes (e.g., alkynes, nitriles and stable isotopes including 2H and 13C), bioorthogonal chemical imaging exhibits superb sensitivity, specificity, multiplicity and biocompatibility for imaging small biomolecules in live systems including tissues and organisms. Exciting biomedical applications such as imaging fatty acid metabolism related to lipotoxicity, glucose uptake and metabolism, drug trafficking, protein synthesis, DNA replication, protein degradation, RNA synthesis and tumor metabolism will be presented. This bioorthogonal chemical imaging platform is compatible with live-cell biology, thus allowing real-time imaging of small-molecule dynamics. Moreover, further chemical and spectroscopic strategies allow for multicolor bioorthogonal chemical imaging, a valuable technique in the era of "omics". We envision that the coupling of SRS microscopy with vibrational probes would do for small biomolecules what fluorescence microscopy of fluorophores has done for larger molecular species, bringing small molecules under the illumination of modern light microscopy.

Percutaneous Image-Guided Screw Fixation of Bone Lesions in Cancer Patients: Double-Centre Analysis of Outcomes including Local Evolution of the Treated Focus

Energy Technology Data Exchange (ETDEWEB)

Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Koch, Guillaume, E-mail: guillaume.koch@chru-strasbourg.fr [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France); Buy, Xavier, E-mail: x.buy@bordeaux.unicancer.fr [Institut Bergonié, Department of Radiology (France); Ramamurthy, Nitin, E-mail: nitin-ramamurthy@hotmail.com [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Tsoumakidou, Georgia, E-mail: georgia.tsoumakidou@chru-strasbourg.fr; Caudrelier, Jean, E-mail: jean.caudrelier@chru-strasbourg.fr [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France); Catena, Vittorio, E-mail: v.catena@bordeaux.unicancer.fr [Institut Bergonié, Department of Radiology (France); Garnon, Julien, E-mail: juleiengarnon@gmail.com [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France); Palussiere, Jean, E-mail: j.palussiere@bordeaux.unicancer.fr [Institut Bergonié, Department of Radiology (France); Gangi, Afshin, E-mail: gangi@unistra.fr [Hôpitaux Universitaires de Strasbourg, HUS, Department of Interventional Radiology, Nouvel Hôpital Civil (France)

2016-10-15

AimTo review outcomes and local evolution of treated lesions following percutaneous image-guided screw fixation (PIGSF) of pathological/insufficiency fractures (PF/InF) and impeding fractures (ImF) in cancer patients at two tertiary centres.Materials and methodsThirty-two consecutive patients (mean age 67.5 years; range 33–86 years) with a range of tumours and prognoses underwent PIGSF for non/minimally displaced PF/InF and ImF. Screws were placed under CT/fluoroscopy or cone-beam CT guidance, with or without cementoplasty. Clinical outcomes were assessed using a simple 4-point scale (1 = worse; 2 = stable; 3 = improved; 4 = significantly improved). Local evolution was reviewed on most recent follow-up imaging. Technical success, complications, and overall survival were evaluated.ResultsThirty-six lesions were treated with 74 screws mainly in the pelvis and femoral neck (58.2 %); including 47.2 % PF, 13.9 % InF, and 38.9 % ImF. Cementoplasty was performed in 63.9 % of the cases. Technical success was 91.6 %. Hospital stay was ≤3 days; 87.1 % of lesions were improved at 1-month follow-up; three major complications (early screw-impingement radiculopathy; accelerated coxarthrosis; late coxofemoral septic arthritis) and one minor complication were observed. Unfavourable local evolution at imaging occurred in 3/24 lesions (12.5 %) at mean 8.7-month follow-up, including poor consolidation (one case) and screw loosening (two cases, at least 1 symptomatic). There were no cases of secondary fractures.ConclusionsPIGSF is feasible for a wide range of oncologic patients, offering good short-term efficacy, acceptable complication rates, and rapid recovery. Unfavourable local evolution at imaging may be relatively frequent, and requires close clinico-radiological surveillance.

Design of Spreading-Codes-Assisted Active Imaging System

Directory of Open Access Journals (Sweden)

Alexey Volkov

2015-07-01

Full Text Available This work discusses an innovative approach to imaging which can improve the robustness of existing active-range measurement methods and potentially enhance their use in a variety of outdoor applications. By merging a proven modulation technique from the domain of spread-spectrum communications with the bleeding-edge CMOS sensor technology, the prototype of the modulated range sensor is designed and evaluated. A suitable set of application-specific spreading codes is proposed, evaluated and tested on the prototype. Experimental results show that the introduced modulation technique significantly reduces the impacts of environmental factors such as sunlight and external light sources, as well as mutual interference of identical devices. The proposed approach can be considered as a promising basis for a new generation of robust and cost-efficient range-sensing solutions for automotive applications, autonomous vehicles or robots.

Imaging cerebral activity in recovery from chronic traumatic brain injury: a preliminary report.

Science.gov (United States)

Lewis, David H; Bluestone, Judith P; Savina, Maryann; Zoller, William H; Meshberg, Emily B; Minoshima, Satoshi

2006-07-01

People in chronic phase of traumatic brain injury (TBI) are often told that there will be no further recovery in brain function, that they are in a "static phase." Holistic Approach to NeuroDevelopment and Learning Efficiency (HANDLE), an alternative therapy, aims to improve function by teaching a series of physical and mental activities that clients perform and encouraging changes in lifestyle. Five subjects (3 males) with chronic TBI (at least 3 years since ictus) completed the HANDLE Institute's program and were prospectively evaluated. Each had six regional cerebral blood flow (rCBF) single-photon emission computed tomography (SPECT) scans over 7 months (scans n= 30). Paired scans were performed with injection of Tc-99m ECD to image rCBF at rest and during the HANDLE "Crossed Arm Bounce" (CAB) exercise before the program, at 3-4 months into the program, and at 6-7 months, after the program had ended. SPECT images were analyzed statistically using Neurostat in which image sets were coregistered and warped into Talaraich atlas for pairwise subtraction between conditions. Group analysis of SPECT showed that CAB activated (increased rCBF) vermis and cerebellar hemispheres in first two paired scans and anterior cingulate and vermis on the final pair. Increased rCBF at rest occurred in cerebellar hemispheres, vermis, and right dorsomedial frontal cortex. These preliminary observations suggest that there may be a role of the hindbrain (vermis and cerebellum) with HANDLE treatment of chronic TBI.

RANZAR Body Systems Framework of diagnostic imaging examination descriptors

International Nuclear Information System (INIS)

Pitman, Alexander D.; Penlington, Lisa; Doromal, Darren; Vukolova, Natalia; Slater, Gregory

2014-01-01

A unified and logical system of descriptors for diagnostic imaging examinations and procedures is a desirable resource for radiology in Australia and New Zealand and is needed to support core activities of RANZCR. Existing descriptor systems available in Australia and New Zealand (including the Medicare DIST and the ACC Schedule) have significant limitations and are inappropriate for broader clinical application. An anatomically based grid was constructed, with anatomical structures arranged in rows and diagnostic imaging modalities arranged in columns (including nuclear medicine and positron emission tomography). The grid was segregated into five body systems. The cells at the intersection of an anatomical structure row and an imaging modality column were populated with short, formulaic descriptors of the applicable diagnostic imaging examinations. Clinically illogical or physically impossible combinations were ‘greyed out’. Where the same examination applied to different anatomical structures, the descriptor was kept identical for the purposes of streamlining. The resulting Body Systems Framework of diagnostic imaging examination descriptors lists all the reasonably common diagnostic imaging examinations currently performed in Australia and New Zealand using a unified grid structure allowing navigation by both referrers and radiologists. The Framework has been placed on the RANZCR website and is available for access free of charge by registered users. The Body Systems Framework of diagnostic imaging examination descriptors is a system of descriptors based on relationships between anatomical structures and imaging modalities. The Framework is now available as a resource and reference point for the radiology profession and to support core College activities.

RANZCR Body Systems Framework of diagnostic imaging examination descriptors.

Science.gov (United States)

Pitman, Alexander G; Penlington, Lisa; Doromal, Darren; Slater, Gregory; Vukolova, Natalia

2014-08-01

A unified and logical system of descriptors for diagnostic imaging examinations and procedures is a desirable resource for radiology in Australia and New Zealand and is needed to support core activities of RANZCR. Existing descriptor systems available in Australia and New Zealand (including the Medicare DIST and the ACC Schedule) have significant limitations and are inappropriate for broader clinical application. An anatomically based grid was constructed, with anatomical structures arranged in rows and diagnostic imaging modalities arranged in columns (including nuclear medicine and positron emission tomography). The grid was segregated into five body systems. The cells at the intersection of an anatomical structure row and an imaging modality column were populated with short, formulaic descriptors of the applicable diagnostic imaging examinations. Clinically illogical or physically impossible combinations were 'greyed out'. Where the same examination applied to different anatomical structures, the descriptor was kept identical for the purposes of streamlining. The resulting Body Systems Framework of diagnostic imaging examination descriptors lists all the reasonably common diagnostic imaging examinations currently performed in Australia and New Zealand using a unified grid structure allowing navigation by both referrers and radiologists. The Framework has been placed on the RANZCR website and is available for access free of charge by registered users. The Body Systems Framework of diagnostic imaging examination descriptors is a system of descriptors based on relationships between anatomical structures and imaging modalities. The Framework is now available as a resource and reference point for the radiology profession and to support core College activities. © 2014 The Royal Australian and New Zealand College of Radiologists.

Roles of medical image processing in medical physics

International Nuclear Information System (INIS)

Arimura, Hidetaka

2011-01-01

Image processing techniques including pattern recognition techniques play important roles in high precision diagnosis and radiation therapy. The author reviews a symposium on medical image information, which was held in the 100th Memorial Annual Meeting of the Japan Society of Medical Physics from September 23rd to 25th. In this symposium, we had three invited speakers, Dr. Akinobu Shimizu, Dr. Hideaki Haneishi, and Dr. Hirohito Mekata, who are active engineering researchers of segmentation, image registration, and pattern recognition, respectively. In this paper, the author reviews the roles of the medical imaging processing in medical physics field, and the talks of the three invited speakers. (author)