Application of Laser Imaging for Bio/geophysical Studies

NASA Technical Reports Server (NTRS)

Hummel, J. R.; Goltz, S. M.; Depiero, N. L.; Degloria, D. P.; Pagliughi, F. M.

1992-01-01

SPARTA, Inc. has developed a low-cost, portable laser imager that, among other applications, can be used in bio/geophysical applications. In the application to be discussed here, the system was utilized as an imaging system for background features in a forested locale. The SPARTA mini-ladar system was used at the International Paper Northern Experimental Forest near Howland, Maine to assist in a project designed to study the thermal and radiometric phenomenology at forest edges. The imager was used to obtain data from three complex sites, a 'seed' orchard, a forest edge, and a building. The goal of the study was to demonstrate the usefulness of the laser imager as a tool to obtain geometric and internal structure data about complex 3-D objects in a natural background. The data from these images have been analyzed to obtain information about the distributions of the objects in a scene. A range detection algorithm has been used to identify individual objects in a laser image and an edge detection algorithm then applied to highlight the outlines of discrete objects. An example of an image processed in such a manner is shown. Described here are the results from the study. In addition, results are presented outlining how the laser imaging system could be used to obtain other important information about bio/geophysical systems, such as the distribution of woody material in forests.

Thermal imaging for assessment of electron-beam freeform fabrication (EBF3) additive manufacturing deposits

NASA Astrophysics Data System (ADS)

Zalameda, Joseph N.; Burke, Eric R.; Hafley, Robert A.; Taminger, Karen M.; Domack, Christopher S.; Brewer, Amy; Martin, Richard E.

2013-05-01

Additive manufacturing is a rapidly growing field where 3-dimensional parts can be produced layer by layer. NASA's electron beam freeform fabrication (EBF3) technology is being evaluated to manufacture metallic parts in a space environment. The benefits of EBF3 technology are weight savings to support space missions, rapid prototyping in a zero gravity environment, and improved vehicle readiness. The EBF3 system is composed of 3 main components: electron beam gun, multi-axis position system, and metallic wire feeder. The electron beam is used to melt the wire and the multi-axis positioning system is used to build the part layer by layer. To insure a quality deposit, a near infrared (NIR) camera is used to image the melt pool and solidification areas. This paper describes the calibration and application of a NIR camera for temperature measurement. In addition, image processing techniques are presented for deposit assessment metrics.

Second-Order Asymptotics for the Classical Capacity of Image-Additive Quantum Channels

NASA Astrophysics Data System (ADS)

Tomamichel, Marco; Tan, Vincent Y. F.

2015-08-01

We study non-asymptotic fundamental limits for transmitting classical information over memoryless quantum channels, i.e. we investigate the amount of classical information that can be transmitted when a quantum channel is used a finite number of times and a fixed, non-vanishing average error is permissible. In this work we consider the classical capacity of quantum channels that are image-additive, including all classical to quantum channels, as well as the product state capacity of arbitrary quantum channels. In both cases we show that the non-asymptotic fundamental limit admits a second-order approximation that illustrates the speed at which the rate of optimal codes converges to the Holevo capacity as the blocklength tends to infinity. The behavior is governed by a new channel parameter, called channel dispersion, for which we provide a geometrical interpretation.

Target detection in active polarization images perturbed with additive noise and illumination nonuniformity.

PubMed

Bénière, Arnaud; Goudail, François; Dolfi, Daniel; Alouini, Mehdi

2009-07-01

Active imaging systems that illuminate a scene with polarized light and acquire two images in two orthogonal polarizations yield information about the intensity contrast and the orthogonal state contrast (OSC) in the scene. Both contrasts are relevant for target detection. However, in real systems, the illumination is often spatially or temporally nonuniform. This creates artificial intensity contrasts that can lead to false alarms. We derive generalized likelihood ratio test (GLRT) detectors, for which intensity information is taken into account or not and determine the relevant expressions of the contrast in these two situations. These results are used to determine in which cases considering intensity information in addition to polarimetric information is relevant or not.

S-SIMS and MetA-SIMS study of organic additives in thin polymer coatings

NASA Astrophysics Data System (ADS)

Adriaensen, L.; Vangaever, F.; Lenaerts, J.; Gijbels, R.

2006-07-01

In the present study a methodology for TOF-S-SIMS measurements is developed to gain information on the distribution of molecules on and in polymer coatings (thickness ˜100 μm). Experiments were carried out on model systems consisting of one or more additive-containing polyvinylbutyral coatings. Several organic additives were selected: carbocyanine dyes, basonyl blue and the pharmaceutical risperidone. The additives have been measured as pure compounds on a Si substrate to obtain good reference spectra. After optimisation of the sample preparation method, the coatings were embedded in epoxy resin and stored in an oven (60 °C) for 24 h. Cross-sections were made by means of a microtome. S-SIMS spectra were taken on the prepared cross-sections before and after Au was deposited on the sample surface. Compared to the untreated samples, the Au covered samples give rise to more intense secondary ion signals. Generally, signals of the intact cations were more intense than those of the fragment ions. Apart from mass spectra, images of the additive distribution in the coatings could also be acquired by recording structural ion signals. It was possible to make secondary ion images of the additive molecule ions with a (sub)-micrometer lateral resolution.

Is whole-body fluorine-18 fluorodeoxyglucose PET/CT plus additional pelvic images (oral hydration-voiding-refilling) useful for detecting recurrent bladder cancer?

PubMed

Yang, Zhongyi; Cheng, Jingyi; Pan, Lingling; Hu, Silong; Xu, Junyan; Zhang, Yongping; Wang, Mingwei; Zhang, Jianping; Ye, Dingwei; Zhang, Yingjian

2012-08-01

Because of the urinary excretion of fluorine-18 fluorodeoxyglucose ((18)F-FDG), FDG-PET or PET/CT is thought of little value in patients with bladder cancer. The purpose of our study was to investigate the value of (18)F-FDG PET/CT with additional pelvic images in detection of recurrent bladder cancers. From December 2006 to August 2010, 35 bladder cancer patients (median age 56 years old, ranging from 35 to 96) underwent routine (18)F-FDG PET/CT. To better detect bladder lesions, a new method called as oral hydration-voiding-refilling was introduced, which included that all the patients firstly received oral hydration, then were required to void frequently and finally were demanded to hold back urine when the additional pelvic images were scanned. Lesions were confirmed by either histopathology or clinical follow-up for at least 6 months. Finally, 12 recurrent cases of 35 patients were confirmed by cystoscope. PET/CT correctly detected 11 of them. Among these 11 true positive patients, 5 patients (45.5 %) were detected only after additional pelvic images. Lichenoid lesions on the bladder wall were missed, which caused 1 false negative result. All three false positive cases were testified to be inflammatory tissues by cystoscope. Therefore, the sensitivity, specificity and accuracy of PET/CT were 91.7 % (11/12), 87.0 % (20/23) and 88.6 % (31/35), respectively. PET/CT with additional pelvic images can highly detect recurrent lesions in residual bladder tissues. Our method with high accuracy and better endurance could be potentially applied.

BRAIN IMAGING IN THE STUDY OF ALZHEIMER'S DISEASE

PubMed Central

Reiman, Eric M.; Jagust, William J.

2012-01-01

Over the last 20 years, there has been extraordinary progress in brain imaging research and its application to the study of Alzheimer's disease (AD). Brain imaging researchers have contributed to the scientific understanding, early detection and tracking of AD. They have set the stage for imaging techniques to play growing roles in the clinical setting, the evaluation of disease-modifying treatments, and the identification of demonstrably effective prevention therapies. They have developed ground-breaking methods, including positron emission tomography (PET) ligands to measure fibrillar amyloid-β (Aβ) deposition, new magnetic resonance imaging (MRI) pulse sequences, and powerful image analysis techniques, to help in these endeavors. Additional work is needed to develop even more powerful imaging methods, to further clarify the relationship and time course of Aβ and other disease processes in the predisposition to AD, to establish the role of brain imaging methods in the clinical setting, and to provide the scientific means and regulatory approval pathway needed to evaluate the range of promising disease-modifying and prevention therapies as quickly as possible. Twenty years from now, AD may not yet be a distant memory, but the best is yet to come. PMID:22173295

An additional reference axis improves femoral rotation alignment in image-free computer navigation assisted total knee arthroplasty.

PubMed

Inui, Hiroshi; Taketomi, Shuji; Nakamura, Kensuke; Sanada, Takaki; Tanaka, Sakae; Nakagawa, Takumi

2013-05-01

Few studies have demonstrated improvement in accuracy of rotational alignment using image-free navigation systems mainly due to the inconsistent registration of anatomical landmarks. We have used an image-free navigation for total knee arthroplasty, which adopts the average algorithm between two reference axes (transepicondylar axis and axis perpendicular to the Whiteside axis) for femoral component rotation control. We hypothesized that addition of another axis (condylar twisting axis measured on a preoperative radiograph) would improve the accuracy. One group using the average algorithm (double-axis group) was compared with the other group using another axis to confirm the accuracy of the average algorithm (triple-axis group). Femoral components were more accurately implanted for rotational alignment in the triple-axis group (ideal: triple-axis group 100%, double-axis group 82%, P<0.05). Copyright © 2013 Elsevier Inc. All rights reserved.

Addition of atropine to submaximal exercise stress testing in patients evaluated for suspected ischaemia with SPECT imaging: a randomized, placebo-controlled trial.

PubMed

Manganelli, Fiore; Spadafora, Marco; Varrella, Paola; Peluso, Giuseppina; Sauro, Rosario; Di Lorenzo, Emilio; Rosato, Giuseppe; Daniele, Stefania; Cuocolo, Alberto

2011-02-01

To evaluate the effects of the addition of atropine to exercise testing in patients who failed to achieve their target heart rate (HR) during stress myocardial perfusion imaging with single-photon emission computed tomography (SPECT). The study was a prospective, randomized, placebo-controlled design. Patients with suspected or known coronary artery disease who failed to achieve a target HR (≥85% of maximal predicted HR) during exercise SPECT imaging were randomized to receive intravenous atropine (n=100) or placebo (n=101). The two groups of patients did not differ with respect to demographic or clinical characteristics. A higher proportion of patients in the atropine group achieved the target HR compared to the placebo group (60% versus 3%, p<0.0001). SPECT imaging was abnormal in a higher proportion of patients in the atropine group as compared to the placebo group (57% versus 42%, p<0.05). Stress-induced myocardial ischaemia was present in more patients in the atropine group as compared to placebo (47% versus 29%, p<0.01). In both groups of patients, no major side effects occurred. The addition of atropine at the end of exercise testing is more effective than placebo in raising HR to adequate levels, without additional risks of complications. The use of atropine in patients who initially failed to achieve their maximal predicted HR is associated with a higher probability of achieving a diagnostic myocardial perfusion study.

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Brain imaging in the study of Alzheimer's disease.

PubMed

Reiman, Eric M; Jagust, William J

2012-06-01

Over the last 20 years, there has been extraordinary progress in brain imaging research and its application to the study of Alzheimer's disease (AD). Brain imaging researchers have contributed to the scientific understanding, early detection and tracking of AD. They have set the stage for imaging techniques to play growing roles in the clinical setting, the evaluation of disease-modifying treatments, and the identification of demonstrably effective prevention therapies. They have developed ground-breaking methods, including positron emission tomography (PET) ligands to measure fibrillar amyloid-β (Aβ) deposition, new magnetic resonance imaging (MRI) pulse sequences, and powerful image analysis techniques, to help in these endeavors. Additional work is needed to develop even more powerful imaging methods, to further clarify the relationship and time course of Aβ and other disease processes in the predisposition to AD, to establish the role of brain imaging methods in the clinical setting, and to provide the scientific means and regulatory approval pathway needed to evaluate the range of promising disease-modifying and prevention therapies as quickly as possible. Twenty years from now, AD may not yet be a distant memory, but the best is yet to come. Copyright © 2011 Elsevier Inc. All rights reserved.

Advances in imaging: impact on studying craniofacial bone structure.

PubMed

Majumdar, S

2003-01-01

Methods for measuring the structure of craniofacial bones are discussed in this paper. In addition to the three-dimensional macro-structure of the craniofacial skeleton, there is considerable interest in imaging the bone at a microscopic resolution in order to depict the micro-architecture of the trabecular bone itself. In addition to the density of the bone, the microarchitecture reflects bone quality. An understanding of bone quality and density changes has implications for a number of craniofacial pathologies, as well as for implant design and understanding the biomechanical function and loading of the jaw. Trabecular bone micro-architecture has been recently imaged using imaging methods such as micro-computed tomography, magnetic resonance imaging, and the images have been used in finite element models to assess bone mechanical properties. In this paper, some of the recent advances in micro-computed tomography and magnetic resonance imaging are reviewed, and their potential for imaging the trabecular bone in mandibular bones is presented. Examples of in vitro and in vivo images are presented.

Intrusive images and intrusive thoughts as different phenomena: two experimental studies.

PubMed

Hagenaars, Muriel A; Brewin, Chris R; van Minnen, Agnes; Holmes, Emily A; Hoogduin, Kees A L

2010-01-01

According to the dual representation theory of PTSD, intrusive trauma images and intrusive verbal thoughts are produced by separate memory systems. In a previous article it was shown that after watching an aversive film, participants in non-movement conditions reported more intrusive images than participants in a free-to-move control condition (Hagenaars, Van Minnen, Holmes, Brewin, & Hoogduin, 2008). The present study investigates whether the experimental conditions of the Hagenaars et al. study had a different effect on intrusive thoughts than on intrusive images. Experiment 2 further investigated the image-thoughts distinction by manipulating stimulus valence (trauma film versus neutral film) and assessing the subsequent development of intrusive images and thoughts. In addition, both experiments studied the impact of peri-traumatic emotions on subsequent intrusive images and thoughts frequency across conditions. Results showed that experimental manipulations (non-movement and trauma film) caused higher levels of intrusive images relative to control conditions (free movement and neutral film) but they did not affect intrusive thoughts. Peri-traumatic anxiety and horror were associated with subsequent higher levels of intrusive images, but not intrusive thoughts. Correlations were inconclusive for anger and sadness. The results suggest intrusive images and thoughts can be manipulated independently and as such can be considered different phenomena.

Study on Hybrid Image Search Technology Based on Texts and Contents

NASA Astrophysics Data System (ADS)

Wang, H. T.; Ma, F. L.; Yan, C.; Pan, H.

2018-05-01

Image search was studied first here based on texts and contents, respectively. The text-based image feature extraction was put forward by integrating the statistical and topic features in view of the limitation of extraction of keywords only by means of statistical features of words. On the other hand, a search-by-image method was put forward based on multi-feature fusion in view of the imprecision of the content-based image search by means of a single feature. The layered-searching method depended on primarily the text-based image search method and additionally the content-based image search was then put forward in view of differences between the text-based and content-based methods and their difficult direct fusion. The feasibility and effectiveness of the hybrid search algorithm were experimentally verified.

Thermal Imaging for Assessment of Electron-Beam Free Form Fabrication (EBF(sup 3)) Additive Manufacturing Welds

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Burke, Eric R.; Hafley, Robert A.; Taminger, Karen M.; Domack, Christopher S.; Brewer, Amy R.; Martin, Richard E.

2013-01-01

Additive manufacturing is a rapidly growing field where 3-dimensional parts can be produced layer by layer. NASA s electron beam free-form fabrication (EBF(sup 3)) technology is being evaluated to manufacture metallic parts in a space environment. The benefits of EBF(sup 3) technology are weight savings to support space missions, rapid prototyping in a zero gravity environment, and improved vehicle readiness. The EBF(sup 3) system is composed of 3 main components: electron beam gun, multi-axis position system, and metallic wire feeder. The electron beam is used to melt the wire and the multi-axis positioning system is used to build the part layer by layer. To insure a quality weld, a near infrared (NIR) camera is used to image the melt pool and solidification areas. This paper describes the calibration and application of a NIR camera for temperature measurement. In addition, image processing techniques are presented for weld assessment metrics.

Studies on image compression and image reconstruction

NASA Technical Reports Server (NTRS)

Sayood, Khalid; Nori, Sekhar; Araj, A.

1994-01-01

During this six month period our works concentrated on three, somewhat different areas. We looked at and developed a number of error concealment schemes for use in a variety of video coding environments. This work is described in an accompanying (draft) Masters thesis. In the thesis we describe application of this techniques to the MPEG video coding scheme. We felt that the unique frame ordering approach used in the MPEG scheme would be a challenge to any error concealment/error recovery technique. We continued with our work in the vector quantization area. We have also developed a new type of vector quantizer, which we call a scan predictive vector quantization. The scan predictive VQ was tested on data processed at Goddard to approximate Landsat 7 HRMSI resolution and compared favorably with existing VQ techniques. A paper describing this work is included. The third area is concerned more with reconstruction than compression. While there is a variety of efficient lossless image compression schemes, they all have a common property that they use past data to encode future data. This is done either via taking differences, context modeling, or by building dictionaries. When encoding large images, this common property becomes a common flaw. When the user wishes to decode just a portion of the image, the requirement that the past history be available forces the decoding of a significantly larger portion of the image than desired by the user. Even with intelligent partitioning of the image dataset, the number of pixels decoded may be four times the number of pixels requested. We have developed an adaptive scanning strategy which can be used with any lossless compression scheme and which lowers the additional number of pixels to be decoded to about 7 percent of the number of pixels requested! A paper describing these results is included.

The Magnetosphere Imager Mission Concept Definition Study

NASA Technical Reports Server (NTRS)

Johnson, L.; Herrmann, M.; Alexander, Reggie; Beabout, Brent; Blevins, Harold; Bridge, Scott; Burruss, Glenda; Buzbee, Tom; Carrington, Connie; Chandler, Holly;

Real-Time X-ray Imaging Reveals Interfacial Growth, Suppression, and Dissolution of Zinc Dendrites Dependent on Anions of Ionic Liquid Additives for Rechargeable Battery Applications.

PubMed

Song, Yuexian; Hu, Jiugang; Tang, Jia; Gu, Wanmiao; He, Lili; Ji, Xiaobo

2016-11-23

The dynamic interfacial growth, suppression, and dissolution of zinc dendrites have been studied with the imidazolium ionic liquids (ILs) as additives on the basis of in situ synchrotron radiation X-ray imaging. The phase contrast difference of real-time images indicates that zinc dendrites are preferentially developed on the substrate surface in the ammoniacal electrolytes. After adding imidazolium ILs, both nucleation overpotential and polarization extent increase in the order of additive-free < EMI-Cl < EMI-PF 6 < EMI-TFSA < EMI-DCA. The real-time X-ray images show that the EMI-Cl can suppress zinc dendrites, but result in the formation of the loose deposits. The EMI-PF 6 and EMI-TFSA additives can smooth the deposit morphology through suppressing the initiation and growth of dendritic zinc. The addition of EMI-DCA increases the number of dendrite initiation sites, whereas it decreases the growth rate of dendrites. Furthermore, the dissolution behaviors of zinc deposits are compared. The zinc dendrites show a slow dissolution process in the additive-free electrolyte, whereas zinc deposits are easily detached from the substrate in the presence of EMI-Cl, EMI-PF 6 , or EMI-TFSA due to the formation of the loose structure. Hence, the dependence of zinc dendrites on anions of imidazolium IL additives during both electrodeposition and dissolution processes has been elucidated. These results could provide the valuable information in perfecting the performance of zinc-based rechargeable batteries.

Flatbed scanners as a source of imaging. Brightness assessment and additives determination in a nickel electroplating bath.

PubMed

Vidal, M; Amigo, J M; Bro, R; Ostra, M; Ubide, C; Zuriarrain, J

2011-05-23

Desktop flatbed scanners are very well-known devices that can provide digitized information of flat surfaces. They are practically present in most laboratories as a part of the computer support. Several quality levels can be found in the market, but all of them can be considered as tools with a high performance and low cost. The present paper shows how the information obtained with a scanner, from a flat surface, can be used with fine results for exploratory and quantitative purposes through image analysis. It provides cheap analytical measurements for assessment of quality parameters of coated metallic surfaces and monitoring of electrochemical coating bath lives. The samples used were steel sheets nickel-plated in an electrodeposition bath. The quality of the final deposit depends on the bath conditions and, especially, on the concentration of the additives in the bath. Some additives become degraded with the bath life and so is the quality of the plate finish. Analysis of the scanner images can be used to follow the evolution of the metal deposit and the concentration of additives in the bath. Principal component analysis (PCA) is applied to find significant differences in the coating of sheets, to find directions of maximum variability and to identify odd samples. The results found are favorably compared with those obtained by means of specular reflectance (SR), which is here used as a reference technique. Also the concentration of additives SPB and SA-1 along a nickel bath life can be followed using image data handled with algorithms such as partial least squares (PLS) regression and support vector regression (SVR). The quantitative results obtained with these and other algorithms are compared. All this opens new qualitative and quantitative possibilities to flatbed scanners. Copyright © 2011 Elsevier B.V. All rights reserved.

Blood vessel segmentation in modern wide-field retinal images in the presence of additive Gaussian noise.

PubMed

Asem, Morteza Modarresi; Oveisi, Iman Sheikh; Janbozorgi, Mona

2018-07-01

Retinal blood vessels indicate some serious health ramifications, such as cardiovascular disease and stroke. Thanks to modern imaging technology, high-resolution images provide detailed information to help analyze retinal vascular features before symptoms associated with such conditions fully develop. Additionally, these retinal images can be used by ophthalmologists to facilitate diagnosis and the procedures of eye surgery. A fuzzy noise reduction algorithm was employed to enhance color images corrupted by Gaussian noise. The present paper proposes employing a contrast limited adaptive histogram equalization to enhance illumination and increase the contrast of retinal images captured from state-of-the-art cameras. Possessing directional properties, the multistructure elements method can lead to high-performance edge detection. Therefore, multistructure elements-based morphology operators are used to detect high-quality image ridges. Following this detection, the irrelevant ridges, which are not part of the vessel tree, were removed by morphological operators by reconstruction, attempting also to keep the thin vessels preserved. A combined method of connected components analysis (CCA) in conjunction with a thresholding approach was further used to identify the ridges that correspond to vessels. The application of CCA can yield higher efficiency when it is locally applied rather than applied on the whole image. The significance of our work lies in the way in which several methods are effectively combined and the originality of the database employed, making this work unique in the literature. Computer simulation results in wide-field retinal images with up to a 200-deg field of view are a testimony of the efficacy of the proposed approach, with an accuracy of 0.9524.

Results of ACTIM: an EDA study on spectral laser imaging

NASA Astrophysics Data System (ADS)

Hamoir, Dominique; Hespel, Laurent; Déliot, Philippe; Boucher, Yannick; Steinvall, Ove; Ahlberg, Jörgen; Larsson, Hakan; Letalick, Dietmar; Lutzmann, Peter; Repasi, Endre; Ritt, Gunnar

2011-11-01

The European Defence Agency (EDA) launched the Active Imaging (ACTIM) study to investigate the potential of active imaging, especially that of spectral laser imaging. The work included a literature survey, the identification of promising military applications, system analyses, a roadmap and recommendations. Passive multi- and hyper-spectral imaging allows discriminating between materials. But the measured radiance in the sensor is difficult to relate to spectral reflectance due to the dependence on e.g. solar angle, clouds, shadows... In turn, active spectral imaging offers a complete control of the illumination, thus eliminating these effects. In addition it allows observing details at long ranges, seeing through degraded atmospheric conditions, penetrating obscurants (foliage, camouflage...) or retrieving polarization information. When 3D, it is suited to producing numerical terrain models and to performing geometry-based identification. Hence fusing the knowledge of ladar and passive spectral imaging will result in new capabilities. We have identified three main application areas for active imaging, and for spectral active imaging in particular: (1) long range observation for identification, (2) mid-range mapping for reconnaissance, (3) shorter range perception for threat detection. We present the system analyses that have been performed for confirming the interests, limitations and requirements of spectral active imaging in these three prioritized applications.

Improvement in perception of image sharpness through the addition of noise and its relationship with memory texture

NASA Astrophysics Data System (ADS)

Wan, Xiazi; Kobayashi, Hiroyuki; Aoki, Naokazu

2015-03-01

In a preceding study, we investigated the effects of image noise on the perception of image sharpness using white noise, and one- and two-dimensional single-frequency sinusoidal patterns as stimuli. This study extends our preceding study by evaluating natural color images, rather than black-and-white patterns. The results showed that the effect of noise in improving image sharpness perception is more evident in blurred images than in sharp images. This is consistent with the results of the preceding study. In another preceding study, we proposed "memory texture" to explain the preferred granularity of images, as a concept similar to "memory color" for preferred color reproduction. We observed individual differences in type of memory texture for each object, that is, white or 1/f noise. This study discusses the relationship between improvement of sharpness perception by adding noise, and the memory texture, following its individual differences. We found that memory texture is one of the elements that affect sharpness perception.

Label-free imaging to study phenotypic behavioural traits of cells in complex co-cultures

NASA Astrophysics Data System (ADS)

Suman, Rakesh; Smith, Gabrielle; Hazel, Kathryn E. A.; Kasprowicz, Richard; Coles, Mark; O'Toole, Peter; Chawla, Sangeeta

2016-02-01

Time-lapse imaging is a fundamental tool for studying cellular behaviours, however studies of primary cells in complex co-culture environments often requires fluorescent labelling and significant light exposure that can perturb their natural function over time. Here, we describe ptychographic phase imaging that permits prolonged label-free time-lapse imaging of microglia in the presence of neurons and astrocytes, which better resembles in vivo microenvironments. We demonstrate the use of ptychography as an assay to study the phenotypic behaviour of microglial cells in primary neuronal co-cultures through the addition of cyclosporine A, a potent immune-modulator.

Assessing the use of an infrared spectrum hyperpixel array imager to measure temperature during additive and subtractive manufacturing

NASA Astrophysics Data System (ADS)

Whitenton, Eric; Heigel, Jarred; Lane, Brandon; Moylan, Shawn

2016-05-01

Accurate non-contact temperature measurement is important to optimize manufacturing processes. This applies to both additive (3D printing) and subtractive (material removal by machining) manufacturing. Performing accurate single wavelength thermography suffers numerous challenges. A potential alternative is hyperpixel array hyperspectral imaging. Focusing on metals, this paper discusses issues involved such as unknown or changing emissivity, inaccurate greybody assumptions, motion blur, and size of source effects. The algorithm which converts measured thermal spectra to emissivity and temperature uses a customized multistep non-linear equation solver to determine the best-fit emission curve. Emissivity dependence on wavelength may be assumed uniform or have a relationship typical for metals. The custom software displays residuals for intensity, temperature, and emissivity to gauge the correctness of the greybody assumption. Initial results are shown from a laser powder-bed fusion additive process, as well as a machining process. In addition, the effects of motion blur are analyzed, which occurs in both additive and subtractive manufacturing processes. In a laser powder-bed fusion additive process, the scanning laser causes the melt pool to move rapidly, causing a motion blur-like effect. In machining, measuring temperature of the rapidly moving chip is a desirable goal to develop and validate simulations of the cutting process. A moving slit target is imaged to characterize how the measured temperature values are affected by motion of a measured target.

A Study of NetCDF as an Approach for High Performance Medical Image Storage

NASA Astrophysics Data System (ADS)

Magnus, Marcone; Coelho Prado, Thiago; von Wangenhein, Aldo; de Macedo, Douglas D. J.; Dantas, M. A. R.

2012-02-01

The spread of telemedicine systems increases every day. The systems and PACS based on DICOM images has become common. This rise reflects the need to develop new storage systems, more efficient and with lower computational costs. With this in mind, this article discusses a study for application in NetCDF data format as the basic platform for storage of DICOM images. The study case comparison adopts an ordinary database, the HDF5 and the NetCDF to storage the medical images. Empirical results, using a real set of images, indicate that the time to retrieve images from the NetCDF for large scale images has a higher latency compared to the other two methods. In addition, the latency is proportional to the file size, which represents a drawback to a telemedicine system that is characterized by a large amount of large image files.

The addition of a sagittal image fusion improves the prostate cancer detection in a sensor-based MRI /ultrasound fusion guided targeted biopsy.

PubMed

Günzel, Karsten; Cash, Hannes; Buckendahl, John; Königbauer, Maximilian; Asbach, Patrick; Haas, Matthias; Neymeyer, Jörg; Hinz, Stefan; Miller, Kurt; Kempkensteffen, Carsten

2017-01-13

To explore the diagnostic benefit of an additional image fusion of the sagittal plane in addition to the standard axial image fusion, using a sensor-based MRI/US fusion platform. During July 2013 and September 2015, 251 patients with at least one suspicious lesion on mpMRI (rated by PI-RADS) were included into the analysis. All patients underwent MRI/US targeted biopsy (TB) in combination with a 10 core systematic prostate biopsy (SB). All biopsies were performed on a sensor-based fusion system. Group A included 162 men who received TB by an axial MRI/US image fusion. Group B comprised 89 men in whom the TB was performed with an additional sagittal image fusion. The median age in group A was 67 years (IQR 61-72) and in group B 68 years (IQR 60-71). The median PSA level in group A was 8.10 ng/ml (IQR 6.05-14) and in group B 8.59 ng/ml (IQR 5.65-12.32). In group A the proportion of patients with a suspicious digital rectal examination (DRE) (14 vs. 29%, p = 0.007) and the proportion of primary biopsies (33 vs 46%, p = 0.046) were significantly lower. The rate of PI-RADS 3 lesions were overrepresented in group A compared to group B (19 vs. 9%; p = 0.044). Classified according to PI-RADS 3, 4 and 5, the detection rates of TB were 42, 48, 75% in group A and 25, 74, 90% in group B. The rate of PCa with a Gleason score ≥7 missed by TB was 33% (18 cases) in group A and 9% (5 cases) in group B; p-value 0.072. An explorative multivariate binary logistic regression analysis revealed that PI-RADS, a suspicious DRE and performing an additional sagittal image fusion were significant predictors for PCa detection in TB. 9 PCa were only detected by TB with sagittal fusion (sTB) and sTB identified 10 additional clinically significant PCa (Gleason ≥7). Performing an additional sagittal image fusion besides the standard axial fusion appears to improve the accuracy of the sensor-based MRI/US fusion platform.

Preliminary study of copper oxide nanoparticles acoustic and magnetic properties for medical imaging

NASA Astrophysics Data System (ADS)

Perlman, Or; Weitz, Iris S.; Azhari, Haim

2015-03-01

The implementation of multimodal imaging in medicine is highly beneficial as different physical properties may provide complementary information, augmented detection ability, and diagnosis verification. Nanoparticles have been recently used as contrast agents for various imaging modalities. Their significant advantage over conventional large-scale contrast agents is the ability of detection at early stages of the disease, being less prone to obstacles on their path to the target region, and possible conjunction to therapeutics. Copper ions play essential role in human health. They are used as a cofactor for multiple key enzymes involved in various fundamental biochemistry processes. Extremely small size copper oxide nanoparticles (CuO-NPs) are readily soluble in water with high colloidal stability yielding high bioavailability. The goal of this study was to examine the magnetic and acoustic characteristics of CuO-NPs in order to evaluate their potential to serve as contrast imaging agent for both MRI and ultrasound. CuO-NPs 7nm in diameter were synthesized by hot solution method. The particles were scanned using a 9.4T MRI and demonstrated a concentration dependent T1 relaxation time shortening phenomenon. In addition, it was revealed that CuO-NPs can be detected using the ultrasonic B-scan imaging. Finally, speed of sound based ultrasonic computed tomography was applied and showed that CuO-NPs can be clearly imaged. In conclusion, the preliminary results obtained, positively indicate that CuO-NPs may be imaged by both MRI and ultrasound. The results motivate additional in-vivo studies, in which the clinical utility of fused images derived from both modalities for diagnosis improvement will be studied.

A correlative imaging based methodology for accurate quantitative assessment of bone formation in additive manufactured implants.

PubMed

Geng, Hua; Todd, Naomi M; Devlin-Mullin, Aine; Poologasundarampillai, Gowsihan; Kim, Taek Bo; Madi, Kamel; Cartmell, Sarah; Mitchell, Christopher A; Jones, Julian R; Lee, Peter D

2016-06-01

A correlative imaging methodology was developed to accurately quantify bone formation in the complex lattice structure of additive manufactured implants. Micro computed tomography (μCT) and histomorphometry were combined, integrating the best features from both, while demonstrating the limitations of each imaging modality. This semi-automatic methodology registered each modality using a coarse graining technique to speed the registration of 2D histology sections to high resolution 3D μCT datasets. Once registered, histomorphometric qualitative and quantitative bone descriptors were directly correlated to 3D quantitative bone descriptors, such as bone ingrowth and bone contact. The correlative imaging allowed the significant volumetric shrinkage of histology sections to be quantified for the first time (~15 %). This technique demonstrated the importance of location of the histological section, demonstrating that up to a 30 % offset can be introduced. The results were used to quantitatively demonstrate the effectiveness of 3D printed titanium lattice implants.

Study on polarization image methods in turbid medium

NASA Astrophysics Data System (ADS)

Fu, Qiang; Mo, Chunhe; Liu, Boyu; Duan, Jin; Zhang, Su; Zhu, Yong

2014-11-01

Polarization imaging detection technology in addition to the traditional imaging information, also can get polarization multi-dimensional information, thus improve the probability of target detection and recognition.Image fusion in turbid medium target polarization image research, is helpful to obtain high quality images. Based on visible light wavelength of light wavelength of laser polarization imaging, through the rotation Angle of polaroid get corresponding linear polarized light intensity, respectively to obtain the concentration range from 5% to 10% of turbid medium target stocks of polarization parameters, introduces the processing of image fusion technology, main research on access to the polarization of the image by using different polarization image fusion methods for image processing, discusses several kinds of turbid medium has superior performance of polarization image fusion method, and gives the treatment effect and analysis of data tables. Then use pixel level, feature level and decision level fusion algorithm on three levels of information fusion, DOLP polarization image fusion, the results show that: with the increase of the polarization Angle, polarization image will be more and more fuzzy, quality worse and worse. Than a single fused image contrast of the image be improved obviously, the finally analysis on reasons of the increase the image contrast and polarized light.

Frequency of recommendations for additional imaging in diagnostic ultrasound examinations: Evaluation of radiologist, technologist, and other examination-related factors.

PubMed

Margolis, Nathaniel E; Rosenkrantz, Andrew B; Babb, James S; Macari, Michael

2015-10-01

Our aim in this study was to evaluate the effect of the radiologist, technologist, and other examination-related factors on the frequency of recommendations for additional imaging (RAI) during sonographic (US) interpretation. We retrospectively reviewed 719 US reports from a single academic medical center for the presence of RAI. All studies had been interpreted by one of three abdominal radiologists. Examinations were performed at an outpatient radiology facility with no onsite radiologist (n = 299) or at an inpatient emergency department or hospital-based outpatient setting that had an onsite radiologist (n = 420). Possible associations between the frequency of RAI and the presence of an onsite radiologist, location of the examination, body part or region imaged, patient age, technologist performing the exam, and radiologist reading the exam were evaluated. There were significant differences between each pair of radiologists in terms of overall frequency of RAI (p < 0.001) (radiologist 1: 12.0% [22/184]; radiologist 2: 21.6% [78/361]; and radiologist 3: 45.5% [79/174]). In addition, there were statistically significant differences in the frequency of RAI among studies scanned by the 10 different US technologists (13.6%-40.0%, p = 0.03). However, other factors such as patient age, patient sex, US unit, patient location, and radiologist location were not associated with the frequency of RAI (p = 0.15-0.93). The individual radiologist and technologist influenced the frequency of RAI for US examinations, whereas other examination-related factors did not. The observed substantial variability in RAI between radiologists and technologists warrants further study, with consideration of strategies to optimize RAI within US reports. © 2015 Wiley Periodicals, Inc.

A Time of Flight Fast Neutron Imaging System Design Study

NASA Astrophysics Data System (ADS)

Canion, Bonnie; Glenn, Andrew; Sheets, Steven; Wurtz, Ron; Nakae, Les; Hausladen, Paul; McConchie, Seth; Blackston, Matthew; Fabris, Lorenzo; Newby, Jason

2017-09-01

LLNL and ORNL are designing an active/passive fast neutron imaging system that is flexible to non-ideal detector positioning. It is often not possible to move an inspection object in fieldable imager applications such as safeguards, arms control treaty verification, and emergency response. Particularly, we are interested in scenarios which inspectors do not have access to all sides of an inspection object, due to interfering objects or walls. This paper will present the results of a simulation-based design parameter study, that will determine the optimum system design parameters for a fieldable system to perform time-of-flight based imaging analysis. The imaging analysis is based on the use of an associated particle imaging deuterium-tritium (API DT) neutron generator to get the time-of-flight of radiation induced within an inspection object. This design study will investigate the optimum design parameters for such a system (e.g. detector size, ideal placement, etc.), as well as the upper and lower feasible design parameters that the system can expect to provide results within a reasonable amount of time (e.g. minimum/maximum detector efficiency, detector standoff, etc.). Ideally the final prototype from this project will be capable of using full-access techniques, such as transmission imaging, when the measurement circumstances allow, but with the additional capability of producing results at reduced accessibility.

Getting the most out of additional guidance information in deformable image registration by leveraging multi-objective optimization

NASA Astrophysics Data System (ADS)

Alderliesten, Tanja; Bosman, Peter A. N.; Bel, Arjan

2015-03-01

Incorporating additional guidance information, e.g., landmark/contour correspondence, in deformable image registration is often desirable and is typically done by adding constraints or cost terms to the optimization function. Commonly, deciding between a "hard" constraint and a "soft" additional cost term as well as the weighting of cost terms in the optimization function is done on a trial-and-error basis. The aim of this study is to investigate the advantages of exploiting guidance information by taking a multi-objective optimization perspective. Hereto, next to objectives related to match quality and amount of deformation, we define a third objective related to guidance information. Multi-objective optimization eliminates the need to a-priori tune a weighting of objectives in a single optimization function or the strict requirement of fulfilling hard guidance constraints. Instead, Pareto-efficient trade-offs between all objectives are found, effectively making the introduction of guidance information straightforward, independent of its type or scale. Further, since complete Pareto fronts also contain less interesting parts (i.e., solutions with near-zero deformation effort), we study how adaptive steering mechanisms can be incorporated to automatically focus more on solutions of interest. We performed experiments on artificial and real clinical data with large differences, including disappearing structures. Results show the substantial benefit of using additional guidance information. Moreover, compared to the 2-objective case, additional computational cost is negligible. Finally, with the same computational budget, use of the adaptive steering mechanism provides superior solutions in the area of interest.

Prompt gamma ray imaging for verification of proton boron fusion therapy: A Monte Carlo study.

PubMed

Shin, Han-Back; Yoon, Do-Kun; Jung, Joo-Young; Kim, Moo-Sub; Suh, Tae Suk

2016-10-01

The purpose of this study was to verify acquisition feasibility of a single photon emission computed tomography image using prompt gamma rays for proton boron fusion therapy (PBFT) and to confirm an enhanced therapeutic effect of PBFT by comparison with conventional proton therapy without use of boron. Monte Carlo simulation was performed to acquire reconstructed image during PBFT. We acquired percentage depth dose (PDD) of the proton beams in a water phantom, energy spectrum of the prompt gamma rays, and tomographic images, including the boron uptake region (BUR; target). The prompt gamma ray image was reconstructed using maximum likelihood expectation maximisation (MLEM) with 64 projection raw data. To verify the reconstructed image, both an image profile and contrast analysis according to the iteration number were conducted. In addition, the physical distance between two BURs in the region of interest of each BUR was measured. The PDD of the proton beam from the water phantom including the BURs shows more efficient than that of conventional proton therapy on tumour region. A 719keV prompt gamma ray peak was clearly observed in the prompt gamma ray energy spectrum. The prompt gamma ray image was reconstructed successfully using 64 projections. Different image profiles including two BURs were acquired from the reconstructed image according to the iteration number. We confirmed successful acquisition of a prompt gamma ray image during PBFT. In addition, the quantitative image analysis results showed relatively good performance for further study. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Preoperative Magnetic Resonance Imaging in Patients With Stage I Invasive Ductal Breast Cancer: A Prospective Randomized Study.

PubMed

Brück, N; Koskivuo, I; Boström, P; Saunavaara, J; Aaltonen, R; Parkkola, R

2018-03-01

Preoperative magnetic resonance imaging has become an important complementary imaging technique in patients with breast cancer, providing additional information for preoperative local staging. Magnetic resonance imaging is recommended selectively in lobular breast cancer and in patients with dense breast tissue in the case when mammography and ultrasound fail to fully evaluate the lesion, but the routine use of magnetic resonance imaging in all patients with invasive ductal carcinoma is controversial. The purpose of this randomized study was to investigate the diagnostic value of preoperative magnetic resonance imaging and its impact on short-term surgical outcome in newly diagnosed unifocal stage I invasive ductal carcinoma. A total of 100 patients were randomized to either receive preoperative breast magnetic resonance imaging or to be scheduled directly to operation without magnetic resonance imaging on a 1:1 basis. There were 50 patients in both study arms. In 14 patients (28%), breast magnetic resonance imaging detected an additional finding and seven of them were found to be malignant. Six additional cancer foci were found in the ipsilateral breast and one in the contralateral breast. Magnetic resonance imaging findings caused a change in planned surgical management in 10 patients (20%). Mastectomy was performed in six patients (12%) in the magnetic resonance imaging group and in two patients (4%) in the control group ( p = 0.140). The breast reoperation rate was 14% in the magnetic resonance imaging group and 24% in the control group ( p = 0.202). The mean interval between referral and first surgical procedure was 34 days in the magnetic resonance imaging group and 21 days in the control group ( p < 0.001). Preoperative magnetic resonance imaging may be beneficial for some patients with early-stage invasive ductal carcinoma, but its routine use is not recommended without specific indications.

Effects of intra-operative fluoroscopic 3D-imaging on peri-operative imaging strategy in calcaneal fracture surgery.

PubMed

Beerekamp, M S H; Backes, M; Schep, N W L; Ubbink, D T; Luitse, J S; Schepers, T; Goslings, J C

2017-12-01

Previous studies demonstrated that intra-operative fluoroscopic 3D-imaging (3D-imaging) in calcaneal fracture surgery is promising to prevent revision surgery and save costs. However, these studies limited their focus to corrections performed after 3D-imaging, thereby neglecting corrections after intra-operative fluoroscopic 2D-imaging (2D-imaging). The aim of this study was to assess the effects of additional 3D-imaging on intra-operative corrections, peri-operative imaging used, and patient-relevant outcomes compared to 2D-imaging alone. In this before-after study, data of adult patients who underwent open reduction and internal fixation (ORIF) of a calcaneal fracture between 2000 and 2014 in our level-I Trauma center were collected. 3D-imaging (BV Pulsera with 3D-RX, Philips Healthcare, Best, The Netherlands) was available as of 2007 at the surgeons' discretion. Patient and fracture characteristics, peri-operative imaging, intra-operative corrections and patient-relevant outcomes were collected from the hospital databases. Patients in whom additional 3D-imaging was applied were compared to those undergoing 2D-imaging alone. A total of 231 patients were included of whom 107 (46%) were operated with the use of 3D-imaging. No significant differences were found in baseline characteristics. The median duration of surgery was significantly longer when using 3D-imaging (2:08 vs. 1:54 h; p = 0.002). Corrections after additional 3D-imaging were performed in 53% of the patients. However, significantly fewer corrections were made after 2D-imaging when 3D-imaging was available (Risk difference (RD) -15%; 95% Confidence interval (CI) -29 to -2). Peri-operative imaging, besides intra-operative 3D-imaging, and patient-relevant outcomes were similar between groups. Intra-operative 3D-imaging provides additional information resulting in additional corrections. Moreover, 3D-imaging probably changed the surgeons' attitude to rely more on 3D-imaging, hence a 15%-decrease of

Tracking tumor boundary in MV-EPID images without implanted markers: A feasibility study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xiaoyong, E-mail: xiaoyong@ieee.org; Homma, Noriyasu, E-mail: homma@ieee.org; Ichiji, Kei, E-mail: ichiji@yoshizawa.ecei.tohoku.ac.jp

2015-05-15

Purpose: To develop a markerless tracking algorithm to track the tumor boundary in megavoltage (MV)-electronic portal imaging device (EPID) images for image-guided radiation therapy. Methods: A level set method (LSM)-based algorithm is developed to track tumor boundary in EPID image sequences. Given an EPID image sequence, an initial curve is manually specified in the first frame. Driven by a region-scalable energy fitting function, the initial curve automatically evolves toward the tumor boundary and stops on the desired boundary while the energy function reaches its minimum. For the subsequent frames, the tracking algorithm updates the initial curve by using the trackingmore » result in the previous frame and reuses the LSM to detect the tumor boundary in the subsequent frame so that the tracking processing can be continued without user intervention. The tracking algorithm is tested on three image datasets, including a 4-D phantom EPID image sequence, four digitally deformable phantom image sequences with different noise levels, and four clinical EPID image sequences acquired in lung cancer treatment. The tracking accuracy is evaluated based on two metrics: centroid localization error (CLE) and volume overlap index (VOI) between the tracking result and the ground truth. Results: For the 4-D phantom image sequence, the CLE is 0.23 ± 0.20 mm, and VOI is 95.6% ± 0.2%. For the digital phantom image sequences, the total CLE and VOI are 0.11 ± 0.08 mm and 96.7% ± 0.7%, respectively. In addition, for the clinical EPID image sequences, the proposed algorithm achieves 0.32 ± 0.77 mm in the CLE and 72.1% ± 5.5% in the VOI. These results demonstrate the effectiveness of the authors’ proposed method both in tumor localization and boundary tracking in EPID images. In addition, compared with two existing tracking algorithms, the proposed method achieves a higher accuracy in tumor localization. Conclusions: In this paper, the authors presented a feasibility study of

Tracking tumor boundary in MV-EPID images without implanted markers: A feasibility study.

PubMed

Zhang, Xiaoyong; Homma, Noriyasu; Ichiji, Kei; Takai, Yoshihiro; Yoshizawa, Makoto

2015-05-01

To develop a markerless tracking algorithm to track the tumor boundary in megavoltage (MV)-electronic portal imaging device (EPID) images for image-guided radiation therapy. A level set method (LSM)-based algorithm is developed to track tumor boundary in EPID image sequences. Given an EPID image sequence, an initial curve is manually specified in the first frame. Driven by a region-scalable energy fitting function, the initial curve automatically evolves toward the tumor boundary and stops on the desired boundary while the energy function reaches its minimum. For the subsequent frames, the tracking algorithm updates the initial curve by using the tracking result in the previous frame and reuses the LSM to detect the tumor boundary in the subsequent frame so that the tracking processing can be continued without user intervention. The tracking algorithm is tested on three image datasets, including a 4-D phantom EPID image sequence, four digitally deformable phantom image sequences with different noise levels, and four clinical EPID image sequences acquired in lung cancer treatment. The tracking accuracy is evaluated based on two metrics: centroid localization error (CLE) and volume overlap index (VOI) between the tracking result and the ground truth. For the 4-D phantom image sequence, the CLE is 0.23 ± 0.20 mm, and VOI is 95.6% ± 0.2%. For the digital phantom image sequences, the total CLE and VOI are 0.11 ± 0.08 mm and 96.7% ± 0.7%, respectively. In addition, for the clinical EPID image sequences, the proposed algorithm achieves 0.32 ± 0.77 mm in the CLE and 72.1% ± 5.5% in the VOI. These results demonstrate the effectiveness of the authors' proposed method both in tumor localization and boundary tracking in EPID images. In addition, compared with two existing tracking algorithms, the proposed method achieves a higher accuracy in tumor localization. In this paper, the authors presented a feasibility study of tracking tumor boundary in EPID images by using a

Advanced MR Imaging of the Human Nucleus Accumbens--Additional Guiding Tool for Deep Brain Stimulation.

PubMed

Lucas-Neto, Lia; Reimão, Sofia; Oliveira, Edson; Rainha-Campos, Alexandre; Sousa, João; Nunes, Rita G; Gonçalves-Ferreira, António; Campos, Jorge G

2015-07-01

The human nucleus accumbens (Acc) has become a target for deep brain stimulation (DBS) in some neuropsychiatric disorders. Nonetheless, even with the most recent advances in neuroimaging it remains difficult to accurately delineate the Acc and closely related subcortical structures, by conventional MRI sequences. It is our purpose to perform a MRI study of the human Acc and to determine whether there are reliable anatomical landmarks that enable the precise location and identification of the nucleus and its core/shell division. For the Acc identification and delineation, based on anatomical landmarks, T1WI, T1IR and STIR 3T-MR images were acquired in 10 healthy volunteers. Additionally, 32-direction DTI was obtained for Acc segmentation. Seed masks for the Acc were generated with FreeSurfer and probabilistic tractography was performed using FSL. The probability of connectivity between the seed voxels and distinct brain areas was determined and subjected to k-means clustering analysis, defining 2 different regions. With conventional T1WI, the Acc borders are better defined through its surrounding anatomical structures. The DTI color-coded vector maps and IR sequences add further detail in the Acc identification and delineation. Additionally, using probabilistic tractography it is possible to segment the Acc into a core and shell division and establish its structural connectivity with different brain areas. Advanced MRI techniques allow in vivo delineation and segmentation of the human Acc and represent an additional guiding tool in the precise and safe target definition for DBS. © 2015 International Neuromodulation Society.

Imaging study of using radiopharmaceuticals labeled with cyclotron-produced 99mTc.

PubMed

Hou, X; Tanguay, J; Vuckovic, M; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

2016-12-07

Cyclotron-produced 99m Tc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based 99m Tc. However, the small amount of 92-98 Mo in the irradiation of enriched 100 Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered. The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.

Imaging study of using radiopharmaceuticals labeled with cyclotron-produced 99mTc

NASA Astrophysics Data System (ADS)

Hou, X.; Tanguay, J.; Vuckovic, M.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

2016-12-01

Cyclotron-produced 99mTc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based 99mTc. However, the small amount of 92-98Mo in the irradiation of enriched 100Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered. The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.

A comparative study of additive and subtractive manufacturing for dental restorations.

PubMed

Bae, Eun-Jeong; Jeong, Il-Do; Kim, Woong-Chul; Kim, Ji-Hwan

2017-08-01

Digital systems have recently found widespread application in the fabrication of dental restorations. For the clinical assessment of dental restorations fabricated digitally, it is necessary to evaluate their accuracy. However, studies of the accuracy of inlay restorations fabricated with additive manufacturing are lacking. The purpose of this in vitro study was to evaluate and compare the accuracy of inlay restorations fabricated by using recently introduced additive manufacturing with the accuracy of subtractive methods. The inlay (distal occlusal cavity) shape was fabricated using 3-dimensional image (reference data) software. Specimens were fabricated using 4 different methods (each n=10, total N=40), including 2 additive manufacturing methods, stereolithography apparatus and selective laser sintering; and 2 subtractive methods, wax and zirconia milling. Fabricated specimens were scanned using a dental scanner and then compared by overlapping reference data. The results were statistically analyzed using a 1-way analysis of variance (α=.05). Additionally, the surface morphology of 1 randomly (the first of each specimen) selected specimen from each group was evaluated using a digital microscope. The results of the overlap analysis of the dental restorations indicated that the root mean square (RMS) deviation observed in the restorations fabricated using the additive manufacturing methods were significantly different from those fabricated using the subtractive methods (P<.05). However, no significant differences were found between restorations fabricated using stereolithography apparatus and selective laser sintering, the additive manufacturing methods (P=.466). Similarly, no significant differences were found between wax and zirconia, the subtractive methods (P=.986). The observed RMS values were 106 μm for stereolithography apparatus, 113 μm for selective laser sintering, 116 μm for wax, and 119 μm for zirconia. Microscopic evaluation of the surface

A study on a portable fluorescence imaging system

NASA Astrophysics Data System (ADS)

Chang, Han-Chao; Wu, Wen-Hong; Chang, Chun-Li; Huang, Kuo-Cheng; Chang, Chung-Hsing; Chiu, Shang-Chen

2011-09-01

The fluorescent reaction is that an organism or dye, excited by UV light (200-405 nm), emits a specific frequency of light; the light is usually a visible or near infrared light (405-900 nm). During the UV light irradiation, the photosensitive agent will be induced to start the photochemical reaction. In addition, the fluorescence image can be used for fluorescence diagnosis and then photodynamic therapy can be given to dental diseases and skin cancer, which has become a useful tool to provide scientific evidence in many biomedical researches. However, most of the methods on acquiring fluorescence biology traces are still stay in primitive stage, catching by naked eyes and researcher's subjective judgment. This article presents a portable camera to obtain the fluorescence image and to make up a deficit from observer competence and subjective judgment. Furthermore, the portable camera offers the 375nm UV-LED exciting light source for user to record fluorescence image and makes the recorded image become persuasive scientific evidence. In addition, when the raising the rate between signal and noise, the signal processing module will not only amplify the fluorescence signal up to 70 %, but also decrease the noise significantly from environmental light on bill and nude mouse testing.

Optimization of SPECT-CT Hybrid Imaging Using Iterative Image Reconstruction for Low-Dose CT: A Phantom Study

PubMed Central

Grosser, Oliver S.; Kupitz, Dennis; Ruf, Juri; Czuczwara, Damian; Steffen, Ingo G.; Furth, Christian; Thormann, Markus; Loewenthal, David; Ricke, Jens; Amthauer, Holger

2015-01-01

Background Hybrid imaging combines nuclear medicine imaging such as single photon emission computed tomography (SPECT) or positron emission tomography (PET) with computed tomography (CT). Through this hybrid design, scanned patients accumulate radiation exposure from both applications. Imaging modalities have been the subject of long-term optimization efforts, focusing on diagnostic applications. It was the aim of this study to investigate the influence of an iterative CT image reconstruction algorithm (ASIR) on the image quality of the low-dose CT images. Methodology/Principal Findings Examinations were performed with a SPECT-CT scanner with standardized CT and SPECT-phantom geometries and CT protocols with systematically reduced X-ray tube currents. Analyses included image quality with respect to photon flux. Results were compared to the standard FBP reconstructed images. The general impact of the CT-based attenuation maps used during SPECT reconstruction was examined for two SPECT phantoms. Using ASIR for image reconstructions, image noise was reduced compared to FBP reconstructions for the same X-ray tube current. The Hounsfield unit (HU) values reconstructed by ASIR were correlated to the FBP HU values(R2 ≥ 0.88) and the contrast-to-noise ratio (CNR) was improved by ASIR. However, for a phantom with increased attenuation, the HU values shifted for low X-ray tube currents I ≤ 60 mA (p ≤ 0.04). In addition, the shift of the HU values was observed within the attenuation corrected SPECT images for very low X-ray tube currents (I ≤ 20 mA, p ≤ 0.001). Conclusion/Significance In general, the decrease in X-ray tube current up to 30 mA in combination with ASIR led to a reduction of CT-related radiation exposure without a significant decrease in image quality. PMID:26390216

Inversion domain boundaries in ZnO with additions of Fe2O3 studied by high-resolution ADF imaging.

PubMed

Wolf, Frank; Freitag, Bert H; Mader, Werner

2007-01-01

Columns of metal atoms in the polytypoid compound Fe2O3(ZnO)15 could be resolved by high angle annular dark field imaging in a transmission electron microscopy (TEM)/STEM electron microscope--a result which could not be realized by high-resolution bright field imaging due to inherent strain from inversion domains and inversion domain boundaries (IDBs) in the crystals. The basal plane IDB was imaged in [11 00] yielding the spacing of the two adjacent ZnO domains, while imaging in [21 1 0] yields the position of single metal ions. The images allow the construction of the entire domain structure including the stacking sequence and positions of the oxygen ions. The IDB consists of a single layer of octahedrally co-ordinated Fe3+ ions, and the inverted ZnO domains are related by point symmetry at the iron position. The FeO6 octahedrons are compressed along the ZnO c-axis resulting in a FeO bond length of 0.208 nm which is in the range of FeO distances in iron containing oxides. The model of the basal plane boundary resembles that of the IDB in polytypoid ZnO-In2O3 compounds.

Clinical and imaging evaluation of the response to intravenous steroids in patients with Graves' orbitopathy and analysis on who requires additional therapy.

PubMed

Tsirouki, Theodora; Bargiota, Alexandra; Tigas, Stelios; Vasileiou, Agathi; Kapsalaki, Eftichia; Giotaki, Zoe; Asproudis, Ioannis; Tsatsoulis, Agathokles; Koukoulis, Georgios; Tsironi, Evangelia E

2016-01-01

The aim of this study was to evaluate the safety and efficacy of an individualized steroid regimen in patients with moderate-to-severe Graves' orbitopathy (GO) by monitoring clinical and imaging parameters. In total, 47 patients with active, moderate-to-severe GO were enrolled in this study. All the patients received the proposed treatment regimen by European Group on GO of 4.5 g of intravenous (IV) methylprednisolone for 12 weeks. At the end of the IV treatment, patients with persistent active GO (Group 1) who were assessed by clinical examination and orbital imaging with short tau inversion recovery-sequence magnetic resonance imaging (STIR MRI) received additional treatment with oral prednisolone, and those with inactive GO (Group 2) received no further treatment. Of the 42 patients who completed the study, 22 (52.4%) patients formed Group 1 and 20 (47.6%) patients Group 2. At the 12th week, the overall response to IV treatment was 76.2%, and clinical activity score (CAS) improvement was 69%. At the 24th week, the overall response was 92.8%, and CAS improvement was 97.6%, without statistically significant difference in CAS and total eye score between these two groups ( P =0.157 and P =0.856, respectively). Ophthalmic manifestations were improved, being absent or minimal in 78.6% of patients at the 24th week follow-up. Recurrence of disease activity occurred in 9.5% of patients up to 24 weeks after the completion of treatment, and major adverse events occurred in 6.4% of patients. In patients with moderate-to-severe GO, IV steroid treatment, followed by oral treatment, when needed, is an effective regimen with low rates of adverse events and recurrences. STIR MRI is a significant tool for recognizing patients who need additional steroid treatment.

Clinical and imaging evaluation of the response to intravenous steroids in patients with Graves’ orbitopathy and analysis on who requires additional therapy

PubMed Central

Tsirouki, Theodora; Bargiota, Alexandra; Tigas, Stelios; Vasileiou, Agathi; Kapsalaki, Eftichia; Giotaki, Zoe; Asproudis, Ioannis; Tsatsoulis, Agathokles; Koukoulis, Georgios; Tsironi, Evangelia E

2016-01-01

Objective The aim of this study was to evaluate the safety and efficacy of an individualized steroid regimen in patients with moderate-to-severe Graves’ orbitopathy (GO) by monitoring clinical and imaging parameters. Methods In total, 47 patients with active, moderate-to-severe GO were enrolled in this study. All the patients received the proposed treatment regimen by European Group on GO of 4.5 g of intravenous (IV) methylprednisolone for 12 weeks. At the end of the IV treatment, patients with persistent active GO (Group 1) who were assessed by clinical examination and orbital imaging with short tau inversion recovery-sequence magnetic resonance imaging (STIR MRI) received additional treatment with oral prednisolone, and those with inactive GO (Group 2) received no further treatment. Results Of the 42 patients who completed the study, 22 (52.4%) patients formed Group 1 and 20 (47.6%) patients Group 2. At the 12th week, the overall response to IV treatment was 76.2%, and clinical activity score (CAS) improvement was 69%. At the 24th week, the overall response was 92.8%, and CAS improvement was 97.6%, without statistically significant difference in CAS and total eye score between these two groups (P=0.157 and P=0.856, respectively). Ophthalmic manifestations were improved, being absent or minimal in 78.6% of patients at the 24th week follow-up. Recurrence of disease activity occurred in 9.5% of patients up to 24 weeks after the completion of treatment, and major adverse events occurred in 6.4% of patients. Conclusion In patients with moderate-to-severe GO, IV steroid treatment, followed by oral treatment, when needed, is an effective regimen with low rates of adverse events and recurrences. STIR MRI is a significant tool for recognizing patients who need additional steroid treatment. PMID:27895458

Improved accuracy of markerless motion tracking on bone suppression images: preliminary study for image-guided radiation therapy (IGRT)

NASA Astrophysics Data System (ADS)

Tanaka, Rie; Sanada, Shigeru; Sakuta, Keita; Kawashima, Hiroki

2015-05-01

The bone suppression technique based on advanced image processing can suppress the conspicuity of bones on chest radiographs, creating soft tissue images obtained by the dual-energy subtraction technique. This study was performed to evaluate the usefulness of bone suppression image processing in image-guided radiation therapy. We demonstrated the improved accuracy of markerless motion tracking on bone suppression images. Chest fluoroscopic images of nine patients with lung nodules during respiration were obtained using a flat-panel detector system (120 kV, 0.1 mAs/pulse, 5 fps). Commercial bone suppression image processing software was applied to the fluoroscopic images to create corresponding bone suppression images. Regions of interest were manually located on lung nodules and automatic target tracking was conducted based on the template matching technique. To evaluate the accuracy of target tracking, the maximum tracking error in the resulting images was compared with that of conventional fluoroscopic images. The tracking errors were decreased by half in eight of nine cases. The average maximum tracking errors in bone suppression and conventional fluoroscopic images were 1.3   ±   1.0 and 3.3   ±   3.3 mm, respectively. The bone suppression technique was especially effective in the lower lung area where pulmonary vessels, bronchi, and ribs showed complex movements. The bone suppression technique improved tracking accuracy without special equipment and implantation of fiducial markers, and with only additional small dose to the patient. Bone suppression fluoroscopy is a potential measure for respiratory displacement of the target. This paper was presented at RSNA 2013 and was carried out at Kanazawa University, JAPAN.

Additive Manufacturing Infrared Inspection

NASA Technical Reports Server (NTRS)

Gaddy, Darrell; Nettles, Mindy

2015-01-01

The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

Compact Video Microscope Imaging System Implemented in Colloid Studies

NASA Technical Reports Server (NTRS)

McDowell, Mark

2002-01-01

Long description Photographs showing fiber-optic light source, microscope and charge-coupled discharge (CCD) camera head connected to camera body, CCD camera body feeding data to image acquisition board in PC, and Cartesian robot controlled via PC board. The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. CMIS can be used in situ with a minimum amount of user intervention. This system can scan, find areas of interest in, focus on, and acquire images automatically. Many multiple-cell experiments require microscopy for in situ observations; this is feasible only with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control. The software also has a user-friendly interface, which can be used independently of the hardware for further post-experiment analysis. CMIS has been successfully developed in the SML Laboratory at the NASA Glenn Research Center and adapted for use for colloid studies and is available for telescience experiments. The main innovations this year are an improved interface, optimized algorithms, and the ability to control conventional full-sized microscopes in addition to compact microscopes. The CMIS software-hardware interface is being integrated into our SML Analysis package, which will be a robust general-purpose image-processing package that can handle over 100 space and industrial applications.

Combined Magnetic Resonance Imaging and Spectroscopic Imaging Approach to Molecular Imaging of Prostate Cancer

PubMed Central

Kurhanewicz, John; Swanson, Mark G.; Nelson, Sarah J.; Vigneron, Daniel B.

2005-01-01

Magnetic resonance spectroscopic imaging (MRSI) provides a noninvasive method of detecting small molecular markers (historically the metabolites choline and citrate) within the cytosol and extracellular spaces of the prostate, and is performed in conjunction with high-resolution anatomic imaging. Recent studies in pre-prostatectomy patients have indicated that the metabolic information provided by MRSI combined with the anatomical information provided by MRI can significantly improve the assessment of cancer location and extent within the prostate, extracapsular spread, and cancer aggressiveness. Additionally, pre- and post-therapy studies have demonstrated the potential of MRI/MRSI to provide a direct measure of the presence and spatial extent of prostate cancer after therapy, a measure of the time course of response, and information concerning the mechanism of therapeutic response. In addition to detecting metabolic biomarkers of disease behavior and therapeutic response, MRI/MRSI guidance can improve tissue selection for ex vivo analysis. High-resolution magic angle spinning (1H HR-MAS) spectroscopy provides a full chemical analysis of MRI/MRSI-targeted tissues prior to pathologic and immunohistochemical analyses of the same tissue. Preliminary 1H HR-MAS spectroscopy studies have already identified unique spectral patterns for healthy glandular and stromal tissues and prostate cancer, determined the composition of the composite in vivo choline peak, and identified the polyamine spermine as a new metabolic marker of prostate cancer. The addition of imaging sequences that provide other functional information within the same exam (dynamic contrast uptake imaging and diffusion-weighted imaging) have also demonstrated the potential to further increase the accuracy of prostate cancer detection and characterization. PMID:12353259

Endoscopic tri-modal imaging for detection of early neoplasia in Barrett's oesophagus: a multi-centre feasibility study using high-resolution endoscopy, autofluorescence imaging and narrow band imaging incorporated in one endoscopy system.

PubMed

Curvers, W L; Singh, R; Song, L-M Wong-Kee; Wolfsen, H C; Ragunath, K; Wang, K; Wallace, M B; Fockens, P; Bergman, J J G H M

2008-02-01

To investigate the diagnostic potential of endoscopic tri-modal imaging and the relative contribution of each imaging modality (i.e. high-resolution endoscopy (HRE), autofluorescence imaging (AFI) and narrow-band imaging (NBI)) for the detection of early neoplasia in Barrett's oesophagus. Prospective multi-centre study. Tertiary referral centres. 84 Patients with Barrett's oesophagus. The Barrett's oesophagus was inspected with HRE followed by AFI. All lesions detected with HRE and/or AFI were subsequently inspected in detail by NBI for the presence of abnormal mucosal and/or microvascular patterns. Biopsies were obtained from all suspicious lesions for blinded histopathological assessment followed by random biopsies. (1) Number of patients with early neoplasia diagnosed by HRE and AFI; (2) number of lesions with early neoplasia detected with HRE and AFI; and (3) reduction of false positive AFI findings after NBI. Per patient analysis: AFI identified all 16 patients with early neoplasia identified with HRE and detected an additional 11 patients with early neoplasia that were not identified with HRE. In three patients no abnormalities were seen but random biopsies revealed HGIN. After HRE inspection, AFI detected an additional 102 lesions; 19 contained HGIN/EC (false positive rate of AFI after HRE: 81%). Detailed inspection with NBI reduced this false positive rate to 26%. In this international multi-centre study, the addition of AFI to HRE increased the detection of both the number of patients and the number of lesions with early neoplasia in patients with Barrett's oesophagus. The false positive rate of AFI was reduced after detailed inspection with NBI.

Multi-institutional Validation Study of Commercially Available Deformable Image Registration Software for Thoracic Images.

PubMed

Kadoya, Noriyuki; Nakajima, Yujiro; Saito, Masahide; Miyabe, Yuki; Kurooka, Masahiko; Kito, Satoshi; Fujita, Yukio; Sasaki, Motoharu; Arai, Kazuhiro; Tani, Kensuke; Yagi, Masashi; Wakita, Akihisa; Tohyama, Naoki; Jingu, Keiichi

2016-10-01

To assess the accuracy of the commercially available deformable image registration (DIR) software for thoracic images at multiple institutions. Thoracic 4-dimensional (4D) CT images of 10 patients with esophageal or lung cancer were used. Datasets for these patients were provided by DIR-lab (dir-lab.com) and included a coordinate list of anatomic landmarks (300 bronchial bifurcations) that had been manually identified. Deformable image registration was performed between the peak-inhale and -exhale images. Deformable image registration error was determined by calculating the difference at each landmark point between the displacement calculated by DIR software and that calculated by the landmark. Eleven institutions participated in this study: 4 used RayStation (RaySearch Laboratories, Stockholm, Sweden), 5 used MIM Software (Cleveland, OH), and 3 used Velocity (Varian Medical Systems, Palo Alto, CA). The ranges of the average absolute registration errors over all cases were as follows: 0.48 to 1.51 mm (right-left), 0.53 to 2.86 mm (anterior-posterior), 0.85 to 4.46 mm (superior-inferior), and 1.26 to 6.20 mm (3-dimensional). For each DIR software package, the average 3-dimensional registration error (range) was as follows: RayStation, 3.28 mm (1.26-3.91 mm); MIM Software, 3.29 mm (2.17-3.61 mm); and Velocity, 5.01 mm (4.02-6.20 mm). These results demonstrate that there was moderate variation among institutions, although the DIR software was the same. We evaluated the commercially available DIR software using thoracic 4D-CT images from multiple centers. Our results demonstrated that DIR accuracy differed among institutions because it was dependent on both the DIR software and procedure. Our results could be helpful for establishing prospective clinical trials and for the widespread use of DIR software. In addition, for clinical care, we should try to find the optimal DIR procedure using thoracic 4D-CT data. Copyright © 2016 Elsevier Inc. All rights

Multi-institutional Validation Study of Commercially Available Deformable Image Registration Software for Thoracic Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kadoya, Noriyuki, E-mail: kadoya.n@rad.med.tohoku.ac.jp; Nakajima, Yujiro; Saito, Masahide

Purpose: To assess the accuracy of the commercially available deformable image registration (DIR) software for thoracic images at multiple institutions. Methods and Materials: Thoracic 4-dimensional (4D) CT images of 10 patients with esophageal or lung cancer were used. Datasets for these patients were provided by DIR-lab ( (dir-lab.com)) and included a coordinate list of anatomic landmarks (300 bronchial bifurcations) that had been manually identified. Deformable image registration was performed between the peak-inhale and -exhale images. Deformable image registration error was determined by calculating the difference at each landmark point between the displacement calculated by DIR software and that calculated bymore » the landmark. Results: Eleven institutions participated in this study: 4 used RayStation (RaySearch Laboratories, Stockholm, Sweden), 5 used MIM Software (Cleveland, OH), and 3 used Velocity (Varian Medical Systems, Palo Alto, CA). The ranges of the average absolute registration errors over all cases were as follows: 0.48 to 1.51 mm (right-left), 0.53 to 2.86 mm (anterior-posterior), 0.85 to 4.46 mm (superior-inferior), and 1.26 to 6.20 mm (3-dimensional). For each DIR software package, the average 3-dimensional registration error (range) was as follows: RayStation, 3.28 mm (1.26-3.91 mm); MIM Software, 3.29 mm (2.17-3.61 mm); and Velocity, 5.01 mm (4.02-6.20 mm). These results demonstrate that there was moderate variation among institutions, although the DIR software was the same. Conclusions: We evaluated the commercially available DIR software using thoracic 4D-CT images from multiple centers. Our results demonstrated that DIR accuracy differed among institutions because it was dependent on both the DIR software and procedure. Our results could be helpful for establishing prospective clinical trials and for the widespread use of DIR software. In addition, for clinical care, we should try to find the optimal DIR procedure using

Differentiation of malignant from benign soft tissue tumours: use of additive qualitative and quantitative diffusion-weighted MR imaging to standard MR imaging at 3.0 T.

PubMed

Lee, So-Yeon; Jee, Won-Hee; Jung, Joon-Yong; Park, Michael Y; Kim, Sun-Ki; Jung, Chan-Kwon; Chung, Yang-Guk

2016-03-01

To determine the added value of diffusion-weighted imaging (DWI) to standard magnetic resonance imaging (MRI) to differentiate malignant from benign soft tissue tumours at 3.0 T. 3.0 T MR images including DWI in 63 patients who underwent surgery for soft tissue tumours were retrospectively analyzed. Two readers independently interpreted MRI for the presence of malignancy in two steps: standard MRI alone, standard MRI and DWI with qualitative and quantitative analysis combined. There were 34 malignant and 29 non-malignant soft tissue tumours. In qualitative analysis, hyperintensity relative to skeletal muscle was more frequent in malignant than benign tumours on DWI (P=0.003). In quantitative analysis, ADCs of malignant tumours were significantly lower than those of non-malignant tumours (P≤0.002): 759±385 vs. 1188±423 μm(2)/sec minimum ADC value, 941±440 vs. 1310±440 μm(2)/sec average ADC value. The mean sensitivity, specificity and accuracy of both readers were 96%, 72%, and 85% on standard MRI alone and 97%, 90%, and 94% on standard MRI with DWI. The addition of DWI to standard MRI improves the diagnostic accuracy for differentiation of malignant from benign soft tissue tumours at 3.0 T. DWI has added value for differentiating malignant from benign soft tissue tumours. Addition of DWI to standard MRI at 3.0 T improves the diagnostic accuracy. Measurements of both ADC min within solid portion and ADC av are helpful.

Investigation of the practical aspects of an additional 0.1 mm copper x-ray spectral filter for cine acquisition mode imaging in a clinical care setting.

PubMed

Fetterly, Kenneth A

2010-11-01

Minimizing the x-ray radiation dose is an important aspect of patient safety during interventional fluoroscopy procedures. This work investigates the practical aspects of an additional 0.1 mm Cu x-ray beam spectral filter applied to cine acquisition mode imaging on patient dose and image quality. Measurements were acquired using clinical interventional imaging systems. Acquisition images of Solid Water phantoms (15-40 cm) were acquired using x-ray beams with the x-ray tube inherent filtration and using an additional 0.1 mm Cu x-ray beam spectral filter. The skin entrance air kerma (dose) rate was measured and the signal difference to noise ratio (SDNR) of an iodine target embedded into the phantom was calculated to assess image quality. X-ray beam parameters were recorded and analyzed and a primary x-ray beam simulation was performed to assess additional x-ray tube burden attributable to the Cu filter. For all phantom thicknesses, the 0.1 mm Cu filter resulted in a 40% reduction in the entrance air kerma rate to the phantoms and a 9% reduction in the SDNR of the iodine phantom. The expected additional tube load required by the 0.1 mm Cu filter ranged from 11% for a 120 kVp x-ray beam to 43% for a 60 kVp beam. For these clinical systems, use of the 0.1 mm Cu filter resulted in a favorable compromise between reduced skin dose rate and image quality and increased x-ray tube burden.

Study of clutter origin in in-vivo epi-optoacoustic imaging of human forearms

NASA Astrophysics Data System (ADS)

Preisser, Stefan; Held, Gerrit; Akarçay, Hidayet G.; Jaeger, Michael; Frenz, Martin

2016-09-01

Epi-optoacoustic (OA) imaging offers flexible clinical diagnostics of the human body when the irradiation optic is attached to or directly integrated into the acoustic probe. Epi-OA images, however, encounter clutter that deteriorates contrast and significantly limits imaging depth. This study elaborates clutter origin in clinical epi-optoacoustic imaging using a linear array probe for scanning the human forearm. We demonstrate that the clutter strength strongly varies with the imaging location but stays stable over time, indicating that clutter is caused by anatomical structures. OA transients which are generated by strong optical absorbers located at the irradiation spot were identified to be the main source of clutter. These transients obscure deep in-plane OA signals when detected by the transducer either directly or after being acoustically scattered in the imaging plane. In addition, OA transients generated in the skin below the probe result in acoustic reverberations, which cause problems in image interpretation and limit imaging depth. Understanding clutter origin allows a better interpretation of clinical OA imaging, helps to design clutter compensation techniques and raises the prospect of contrast optimization via the design of the irradiation geometry.

A Study of Imaging Interferometer Simulators

NASA Technical Reports Server (NTRS)

Allen, Ronald J.

2002-01-01

Several new space science mission concepts under development at NASA-GSFC for astronomy are intended to carry out synthetic imaging using Michelson interferometers or direct (Fizeau) imaging with sparse apertures. Examples of these mission concepts include the Stellar Imager (SI), the Space Infrared Interferometric Telescope (SPIRIT), the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS), and the Fourier-Kelvin Stellar Interferometer (FKSI). We have been developing computer-based simulators for these missions. These simulators are aimed at providing a quantitative evaluation of the imaging capabilities of the mission by modelling the performance on different realistic targets in terms of sensitivity, angular resolution, and dynamic range. Both Fizeau and Michelson modes of operation can be considered. Our work is based on adapting a computer simulator called imSIM, which was initially written for the Space Interferometer Mission in order to simulate the imaging mode of new missions such as those listed. In a recent GSFC-funded study we have successfully written a preliminary version of a simulator SISIM for the Stellar Imager and carried out some preliminary studies with it. In a separately funded study we have also been applying these methods to SPECS/SPIRIT.

Study of spin-scan imaging for outer planets missions: Executive summary

NASA Technical Reports Server (NTRS)

Russell, E. E.; Chandos, R. A.; Kodak, J. C.; Pellicori, S. F.; Tomasko, M. G.

1974-01-01

The development and characteristics of spin-scan imagers for interplanetary exploration are discussed. The spin-scan imaging photopolarimeter instruments of Pioneer 10 and 11 are described. In addition to the imaging function, the instruments are also used in a faint-light mode to take sky maps in both radiance and polarization. The performance of a visible-infrared spin-scan radiometer (VISSR), which operates in both visible and infrared wavelengths, is reported.

Imaging study on acupuncture points

NASA Astrophysics Data System (ADS)

Yan, X. H.; Zhang, X. Y.; Liu, C. L.; Dang, R. S.; Ando, M.; Sugiyama, H.; Chen, H. S.; Ding, G. H.

2009-09-01

The topographic structures of acupuncture points were investigated by using the synchrotron radiation based Dark Field Image (DFI) method. Four following acupuncture points were studied: Sanyinjiao, Neiguan, Zusanli and Tianshu. We have found that at acupuncture point regions there exists the accumulation of micro-vessels. The images taken in the surrounding tissue out of the acupuncture points do not show such kind of structure. It is the first time to reveal directly the specific structure of acupuncture points by X-ray imaging.

High-Spatial- and High-Temporal-Resolution Dynamic Contrast-enhanced MR Breast Imaging with Sweep Imaging with Fourier Transformation: A Pilot Study

PubMed Central

Benson, John C.; Idiyatullin, Djaudat; Snyder, Angela L.; Snyder, Carl J.; Hutter, Diane; Everson, Lenore I.; Eberly, Lynn E.; Nelson, Michael T.; Garwood, Michael

2015-01-01

Purpose To report the results of sweep imaging with Fourier transformation (SWIFT) magnetic resonance (MR) imaging for diagnostic breast imaging. Materials and Methods Informed consent was obtained from all participants under one of two institutional review board–approved, HIPAA-compliant protocols. Twelve female patients (age range, 19–54 years; mean age, 41.2 years) and eight normal control subjects (age range, 22–56 years; mean age, 43.2 years) enrolled and completed the study from January 28, 2011, to March 5, 2013. Patients had previous lesions that were Breast Imaging Reporting and Data System 4 and 5 based on mammography and/or ultrasonographic imaging. Contrast-enhanced SWIFT imaging was completed by using a 4-T research MR imaging system. Noncontrast studies were completed in the normal control subjects. One of two sized single-breast SWIFT-compatible transceiver coils was used for nine patients and five controls. Three patients and five control subjects used a SWIFT-compatible dual breast coil. Temporal resolution was 5.9–7.5 seconds. Spatial resolution was 1.00 mm isotropic, with later examinations at 0.67 mm isotropic, and dual breast at 1.00 mm or 0.75 mm isotropic resolution. Results Two nonblinded breast radiologists reported SWIFT image findings of normal breast tissue, benign fibroadenomas (six of six lesions), and malignant lesions (10 of 12 lesions) concordant with other imaging modalities and pathologic reports. Two lesions in two patients were not visualized because of coil field of view. The images yielded by SWIFT showed the presence and extent of known breast lesions. Conclusion The SWIFT technique could become an important addition to breast imaging modalities because it provides high spatial resolution at all points during the dynamic contrast-enhanced examination. © RSNA, 2014 PMID:25247405

Addition of right-sided and posterior precordial leads during stress testing.

PubMed

Shry, Eric A; Eckart, Robert E; Furgerson, James L; Stajduhar, Karl C; Krasuski, Richard A

2003-12-01

Exercise treadmill testing has limited sensitivity for the detection of coronary artery disease, frequently requiring the addition of imaging modalities to enhance the predictive value of the test. Recently, there has been interest in using nonstandard electrocardiographic (ECG) leads during exercise testing. We consecutively enrolled all patients undergoing exercise myocardial imaging with four additional leads recorded (V4R, V7, V8, and V9). The test characteristics of the 12-lead, the 15-lead (12-lead, V7, V8, V9), and the 16-lead (12-lead, V4R, V7, V8, V9) ECGs were compared with stress imaging in all patients. In the subset of patients who underwent angiography within 60 days of stress testing, these lead arrays were compared with the catheterization findings. There were 727 subjects who met entry criteria. The mean age was 58.5 +/- 12.3 years, and 366 (50.3%) were women. Pretest probability for disease was high in 241 (33.1%), intermediate in 347 (47.7%), and low in 139 (19.1%). A total of 166 subjects had an abnormal 12-lead ECG during exercise. The addition of 3 posterior leads to the standard 12-lead ECG resulted in 7 additional subjects having an abnormal electrocardiographic response to exercise. The addition of V4R resulted in only 1 additional patient having an abnormal ECG during exercise. The sensitivity of the ECG for detecting ischemia as determined by stress imaging was 36.6%, 39.2%, and 40.0% (P = NS) for the 12-lead, 15-lead, and 16-lead ECGs, respectively. In those with catheterization data (n = 123), the sensitivity for determining obstructive coronary artery disease was 43.5%, 45.2%, and 45.2% (P = NS) for the 12-lead, 15-lead, and 16-lead ECGs, respectively. The sensitivity of imaging modalities was 77.4% when compared with catheterization. In patients undergoing stress imaging studies, the addition of right-sided and posterior leads did not significantly increase the sensitivity of the ECG for the detection of myocardial ischemia

Direct laser additive fabrication system with image feedback control

DOEpatents

Griffith, Michelle L.; Hofmeister, William H.; Knorovsky, Gerald A.; MacCallum, Danny O.; Schlienger, M. Eric; Smugeresky, John E.

2002-01-01

A closed-loop, feedback-controlled direct laser fabrication system is disclosed. The feedback refers to the actual growth conditions obtained by real-time analysis of thermal radiation images. The resulting system can fabricate components with severalfold improvement in dimensional tolerances and surface finish.

A qualitative study of body image and appearance among men of Chinese ancestry in Australia.

PubMed

Watt, Merran; Ricciardelli, Lina A

2012-01-01

Little is known about the body image of non-White men living in Western countries, even though it has been suggested that they may be more at risk of body image concerns, especially if they internalize Western ideals. This study focused on identifying the main body image and appearance themes among 15 men of Chinese ancestry in Australia using semi-structured interviews and grounded theory. Moderate muscularity was the preferred ideal and height dissatisfaction was shown to be the primary concern. The majority was not invested in achieving muscularity and had a "holistic" approach to their body image that included concerns about hairstyling and clothing. In addition, the men were influenced by both Asian and Western ideals, and this included comparison targets with both Asian and Western men. Further studies are needed to assess the extent of men's body image and appearance concerns, and the role played by Asian and Western influences. Copyright © 2011 Elsevier Ltd. All rights reserved.

Studying time of flight imaging through scattering media across multiple size scales (Conference Presentation)

NASA Astrophysics Data System (ADS)

Velten, Andreas

2017-05-01

Light scattering is a primary obstacle to optical imaging in a variety of different environments and across many size and time scales. Scattering complicates imaging on large scales when imaging through the atmosphere when imaging from airborne or space borne platforms, through marine fog, or through fog and dust in vehicle navigation, for example in self driving cars. On smaller scales, scattering is the major obstacle when imaging through human tissue in biomedical applications. Despite the large variety of participating materials and size scales, light transport in all these environments is usually described with very similar scattering models that are defined by the same small set of parameters, including scattering and absorption length and phase function. We attempt a study of scattering and methods of imaging through scattering across different scales and media, particularly with respect to the use of time of flight information. We can show that using time of flight, in addition to spatial information, provides distinct advantages in scattering environments. By performing a comparative study of scattering across scales and media, we are able to suggest scale models for scattering environments to aid lab research. We also can transfer knowledge and methodology between different fields.

An image assessment study of image acceptability of the Galileo low gain antenna mission

NASA Technical Reports Server (NTRS)

Chuang, S. L.; Haines, R. F.; Grant, T.; Gold, Yaron; Cheung, Kar-Ming

1994-01-01

This paper describes a study conducted by NASA Ames Research Center (ARC) in collaboration with the Jet Propulsion Laboratory (JPL), Pasadena, California on the image acceptability of the Galileo Low Gain Antenna mission. The primary objective of the study is to determine the impact of the Integer Cosine Transform (ICT) compression algorithm on Galilean images of atmospheric bodies, moons, asteroids and Jupiter's rings. The approach involved fifteen volunteer subjects representing twelve institutions involved with the Galileo Solid State Imaging (SSI) experiment. Four different experiment specific quantization tables (q-table) and various compression stepsizes (q-factor) to achieve different compression ratios were used. It then determined the acceptability of the compressed monochromatic astronomical images as evaluated by Galileo SSI mission scientists. Fourteen different images were evaluated. Each observer viewed two versions of the same image side by side on a high resolution monitor, each was compressed using a different quantization stepsize. They were requested to select which image had the highest overall quality to support them in carrying out their visual evaluations of image content. Then they rated both images using a scale from one to five on its judged degree of usefulness. Up to four pre-selected types of images were presented with and without noise to each subject based upon results of a previously administered survey of their image preferences. Fourteen different images in seven image groups were studied. The results showed that: (1) acceptable compression ratios vary widely with the type of images; (2) noisy images detract greatly from image acceptability and acceptable compression ratios; and (3) atmospheric images of Jupiter seem to have higher compression ratios of 4 to 5 times that of some clear surface satellite images.

The effect of image quality, repeated study, and assessment method on anatomy learning.

PubMed

Fenesi, Barbara; Mackinnon, Chelsea; Cheng, Lucia; Kim, Joseph A; Wainman, Bruce C

2017-06-01

The use of two-dimensional (2D) images is consistently used to prepare anatomy students for handling real specimen. This study examined whether the quality of 2D images is a critical component in anatomy learning. The visual clarity and consistency of 2D anatomical images was systematically manipulated to produce low-quality and high-quality images of the human hand and human eye. On day 0, participants learned about each anatomical specimen from paper booklets using either low-quality or high-quality images, and then completed a comprehension test using either 2D images or three-dimensional (3D) cadaveric specimens. On day 1, participants relearned each booklet, and on day 2 participants completed a final comprehension test using either 2D images or 3D cadaveric specimens. The effect of image quality on learning varied according to anatomical content, with high-quality images having a greater effect on improving learning of hand anatomy than eye anatomy (high-quality vs. low-quality for hand anatomy P = 0.018; high-quality vs. low-quality for eye anatomy P = 0.247). Also, the benefit of high-quality images on hand anatomy learning was restricted to performance on short-answer (SA) questions immediately after learning (high-quality vs. low-quality on SA questions P = 0.018), but did not apply to performance on multiple-choice (MC) questions (high-quality vs. low-quality on MC questions P = 0.109) or after participants had an additional learning opportunity (24 hours later) with anatomy content (high vs. low on SA questions P = 0.643). This study underscores the limited impact of image quality on anatomy learning, and questions whether investment in enhancing image quality of learning aids significantly promotes knowledge development. Anat Sci Educ 10: 249-261. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

Investigation of microstructure in additive manufactured Inconel 625 by spatially resolved neutron transmission spectroscopy

DOE PAGES

Tremsin, Anton S.; Gao, Yan; Dial, Laura C.; ...

2016-07-08

Non-destructive testing techniques based on neutron imaging and diffraction can provide information on the internal structure of relatively thick metal samples (up to several cm), which are opaque to other conventional non-destructive methods. Spatially resolved neutron transmission spectroscopy is an extension of traditional neutron radiography, where multiple images are acquired simultaneously, each corresponding to a narrow range of energy. The analysis of transmission spectra enables studies of bulk microstructures at the spatial resolution comparable to the detector pixel. In this study we demonstrate the possibility of imaging (with ~100 μm resolution) distribution of some microstructure properties, such as residual strain,more » texture, voids and impurities in Inconel 625 samples manufactured with an additive manufacturing method called direct metal laser melting (DMLM). Although this imaging technique can be implemented only in a few large-scale facilities, it can be a valuable tool for optimization of additive manufacturing techniques and materials and for correlating bulk microstructure properties to manufacturing process parameters. Additionally, the experimental strain distribution can help validate finite element models which many industries use to predict the residual stress distributions in additive manufactured components.« less

Investigation of microstructure in additive manufactured Inconel 625 by spatially resolved neutron transmission spectroscopy.

PubMed

Tremsin, Anton S; Gao, Yan; Dial, Laura C; Grazzi, Francesco; Shinohara, Takenao

2016-01-01

Non-destructive testing techniques based on neutron imaging and diffraction can provide information on the internal structure of relatively thick metal samples (up to several cm), which are opaque to other conventional non-destructive methods. Spatially resolved neutron transmission spectroscopy is an extension of traditional neutron radiography, where multiple images are acquired simultaneously, each corresponding to a narrow range of energy. The analysis of transmission spectra enables studies of bulk microstructures at the spatial resolution comparable to the detector pixel. In this study we demonstrate the possibility of imaging (with ~100 μm resolution) distribution of some microstructure properties, such as residual strain, texture, voids and impurities in Inconel 625 samples manufactured with an additive manufacturing method called direct metal laser melting (DMLM). Although this imaging technique can be implemented only in a few large-scale facilities, it can be a valuable tool for optimization of additive manufacturing techniques and materials and for correlating bulk microstructure properties to manufacturing process parameters. In addition, the experimental strain distribution can help validate finite element models which many industries use to predict the residual stress distributions in additive manufactured components.

Investigation of microstructure in additive manufactured Inconel 625 by spatially resolved neutron transmission spectroscopy

NASA Astrophysics Data System (ADS)

Tremsin, Anton S.; Gao, Yan; Dial, Laura C.; Grazzi, Francesco; Shinohara, Takenao

2016-01-01

Non-destructive testing techniques based on neutron imaging and diffraction can provide information on the internal structure of relatively thick metal samples (up to several cm), which are opaque to other conventional non-destructive methods. Spatially resolved neutron transmission spectroscopy is an extension of traditional neutron radiography, where multiple images are acquired simultaneously, each corresponding to a narrow range of energy. The analysis of transmission spectra enables studies of bulk microstructures at the spatial resolution comparable to the detector pixel. In this study we demonstrate the possibility of imaging (with 100 μm resolution) distribution of some microstructure properties, such as residual strain, texture, voids and impurities in Inconel 625 samples manufactured with an additive manufacturing method called direct metal laser melting (DMLM). Although this imaging technique can be implemented only in a few large-scale facilities, it can be a valuable tool for optimization of additive manufacturing techniques and materials and for correlating bulk microstructure properties to manufacturing process parameters. In addition, the experimental strain distribution can help validate finite element models which many industries use to predict the residual stress distributions in additive manufactured components.

Investigation of microstructure in additive manufactured Inconel 625 by spatially resolved neutron transmission spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tremsin, Anton S.; Gao, Yan; Dial, Laura C.

Non-destructive testing techniques based on neutron imaging and diffraction can provide information on the internal structure of relatively thick metal samples (up to several cm), which are opaque to other conventional non-destructive methods. Spatially resolved neutron transmission spectroscopy is an extension of traditional neutron radiography, where multiple images are acquired simultaneously, each corresponding to a narrow range of energy. The analysis of transmission spectra enables studies of bulk microstructures at the spatial resolution comparable to the detector pixel. In this study we demonstrate the possibility of imaging (with ~100 μm resolution) distribution of some microstructure properties, such as residual strain,more » texture, voids and impurities in Inconel 625 samples manufactured with an additive manufacturing method called direct metal laser melting (DMLM). Although this imaging technique can be implemented only in a few large-scale facilities, it can be a valuable tool for optimization of additive manufacturing techniques and materials and for correlating bulk microstructure properties to manufacturing process parameters. Additionally, the experimental strain distribution can help validate finite element models which many industries use to predict the residual stress distributions in additive manufactured components.« less

Investigation of microstructure in additive manufactured Inconel 625 by spatially resolved neutron transmission spectroscopy

PubMed Central

Tremsin, Anton S.; Gao, Yan; Dial, Laura C.; Grazzi, Francesco; Shinohara, Takenao

2016-01-01

Abstract Non-destructive testing techniques based on neutron imaging and diffraction can provide information on the internal structure of relatively thick metal samples (up to several cm), which are opaque to other conventional non-destructive methods. Spatially resolved neutron transmission spectroscopy is an extension of traditional neutron radiography, where multiple images are acquired simultaneously, each corresponding to a narrow range of energy. The analysis of transmission spectra enables studies of bulk microstructures at the spatial resolution comparable to the detector pixel. In this study we demonstrate the possibility of imaging (with ~100 μm resolution) distribution of some microstructure properties, such as residual strain, texture, voids and impurities in Inconel 625 samples manufactured with an additive manufacturing method called direct metal laser melting (DMLM). Although this imaging technique can be implemented only in a few large-scale facilities, it can be a valuable tool for optimization of additive manufacturing techniques and materials and for correlating bulk microstructure properties to manufacturing process parameters. In addition, the experimental strain distribution can help validate finite element models which many industries use to predict the residual stress distributions in additive manufactured components. PMID:27877885

Feasibility study of the neutron dose for real-time image-guided proton therapy: A Monte Carlo study

NASA Astrophysics Data System (ADS)

Kim, Jin Sung; Shin, Jung Suk; Kim, Daehyun; Shin, Eunhyuk; Chung, Kwangzoo; Cho, Sungkoo; Ahn, Sung Hwan; Ju, Sanggyu; Chung, Yoonsun; Jung, Sang Hoon; Han, Youngyih

2015-07-01

Two full rotating gantries with different nozzles (multipurpose nozzle with MLC, scanning dedicated nozzle) for a conventional cyclotron system are installed and being commissioned for various proton treatment options at Samsung Medical Center in Korea. The purpose of this study is to use Monte Carlo simulation to investigate the neutron dose equivalent per therapeutic dose, H/D, for X-ray imaging equipment under various treatment conditions. At first, we investigated the H/D for various modifications of the beamline devices (scattering, scanning, multi-leaf collimator, aperture, compensator) at the isocenter and at 20, 40 and 60 cm distances from the isocenter, and we compared our results with those of other research groups. Next, we investigated the neutron dose at the X-ray equipment used for real-time imaging under various treatment conditions. Our investigation showed doses of 0.07 ~ 0.19 mSv/Gy at the X-ray imaging equipment, depending on the treatment option and interestingly, the 50% neutron dose reduction was observed due to multileaf collimator during proton scanning treatment with the multipurpose nozzle. In future studies, we plan to measure the neutron dose experimentally and to validate the simulation data for X-ray imaging equipment for use as an additional neutron dose reduction method.

Reevaluation of JPEG image compression to digitalized gastrointestinal endoscopic color images: a pilot study

NASA Astrophysics Data System (ADS)

Kim, Christopher Y.

1999-05-01

Endoscopic images p lay an important role in describing many gastrointestinal (GI) disorders. The field of radiology has been on the leading edge of creating, archiving and transmitting digital images. With the advent of digital videoendoscopy, endoscopists now have the ability to generate images for storage and transmission. X-rays can be compressed 30-40X without appreciable decline in quality. We reported results of a pilot study using JPEG compression of 24-bit color endoscopic images. For that study, the result indicated that adequate compression ratios vary according to the lesion and that images could be compressed to between 31- and 99-fold smaller than the original size without an appreciable decline in quality. The purpose of this study was to expand upon the methodology of the previous sty with an eye towards application for the WWW, a medium which would expand both clinical and educational purposes of color medical imags. The results indicate that endoscopists are able to tolerate very significant compression of endoscopic images without loss of clinical image quality. This finding suggests that even 1 MB color images can be compressed to well under 30KB, which is considered a maximal tolerable image size for downloading on the WWW.

A quantitative experimental phantom study on MRI image uniformity.

PubMed

Felemban, Doaa; Verdonschot, Rinus G; Iwamoto, Yuri; Uchiyama, Yuka; Kakimoto, Naoya; Kreiborg, Sven; Murakami, Shumei

2018-05-23

Our goal was to assess MR image uniformity by investigating aspects influencing said uniformity via a method laid out by the National Electrical Manufacturers Association (NEMA). Six metallic materials embedded in a glass phantom were scanned (i.e. Au, Ag, Al, Au-Ag-Pd alloy, Ti and Co-Cr alloy) as well as a reference image. Sequences included spin echo (SE) and gradient echo (GRE) scanned in three planes (i.e. axial, coronal, and sagittal). Moreover, three surface coil types (i.e. head and neck, Brain, and temporomandibular joint coils) and two image correction methods (i.e. surface coil intensity correction or SCIC, phased array uniformity enhancement or PURE) were employed to evaluate their effectiveness on image uniformity. Image uniformity was assessed using the National Electrical Manufacturers Association peak-deviation non-uniformity method. Results showed that temporomandibular joint coils elicited the least uniform image and brain coils outperformed head and neck coils when metallic materials were present. Additionally, when metallic materials were present, spin echo outperformed gradient echo especially for Co-Cr (particularly in the axial plane). Furthermore, both SCIC and PURE improved image uniformity compared to uncorrected images, and SCIC slightly surpassed PURE when metallic metals were present. Lastly, Co-Cr elicited the least uniform image while other metallic materials generally showed similar patterns (i.e. no significant deviation from images without metallic metals). Overall, a quantitative understanding of the factors influencing MR image uniformity (e.g. coil type, imaging method, metal susceptibility, and post-hoc correction method) is advantageous to optimize image quality, assists clinical interpretation, and may result in improved medical and dental care.

Feasibility of generating quantitative composition images in dual energy mammography: a simulation study

NASA Astrophysics Data System (ADS)

Lee, Donghoon; Kim, Ye-seul; Choi, Sunghoon; Lee, Haenghwa; Choi, Seungyeon; Kim, Hee-Joung

2016-03-01

Breast cancer is one of the most common malignancies in women. For years, mammography has been used as the gold standard for localizing breast cancer, despite its limitation in determining cancer composition. Therefore, the purpose of this simulation study is to confirm the feasibility of obtaining tumor composition using dual energy digital mammography. To generate X-ray sources for dual energy mammography, 26 kVp and 39 kVp voltages were generated for low and high energy beams, respectively. Additionally, the energy subtraction and inverse mapping functions were applied to provide compositional images. The resultant images showed that the breast composition obtained by the inverse mapping function with cubic fitting achieved the highest accuracy and least noise. Furthermore, breast density analysis with cubic fitting showed less than 10% error compare to true values. In conclusion, this study demonstrated the feasibility of creating individual compositional images and capability of analyzing breast density effectively.

Image enhancement based on in vivo hyperspectral gastroscopic images: a case study

NASA Astrophysics Data System (ADS)

Gu, Xiaozhou; Han, Zhimin; Yao, Liqing; Zhong, Yunshi; Shi, Qiang; Fu, Ye; Liu, Changsheng; Wang, Xiguang; Xie, Tianyu

2016-10-01

Hyperspectral imaging (HSI) has been recognized as a powerful tool for noninvasive disease detection in the gastrointestinal field. However, most of the studies on HSI in this field have involved ex vivo biopsies or resected tissues. We proposed an image enhancement method based on in vivo hyperspectral gastroscopic images. First, we developed a flexible gastroscopy system capable of obtaining in vivo hyperspectral images of different types of stomach disease mucosa. Then, depending on a specific object, an appropriate band selection algorithm based on dependence of information was employed to determine a subset of spectral bands that would yield useful spatial information. Finally, these bands were assigned to be the color components of an enhanced image of the object. A gastric ulcer case study demonstrated that our method yields higher color tone contrast, which enhanced the displays of the gastric ulcer regions, and that it will be valuable in clinical applications.

Preliminary Study on Appearance-Based Detection of Anatomical Point Landmarks in Body Trunk CT Images

NASA Astrophysics Data System (ADS)

Nemoto, Mitsutaka; Nomura, Yukihiro; Hanaoka, Shohei; Masutani, Yoshitaka; Yoshikawa, Takeharu; Hayashi, Naoto; Yoshioka, Naoki; Ohtomo, Kuni

Anatomical point landmarks as most primitive anatomical knowledge are useful for medical image understanding. In this study, we propose a detection method for anatomical point landmark based on appearance models, which include gray-level statistical variations at point landmarks and their surrounding area. The models are built based on results of Principal Component Analysis (PCA) of sample data sets. In addition, we employed generative learning method by transforming ROI of sample data. In this study, we evaluated our method with 24 data sets of body trunk CT images and obtained 95.8 ± 7.3 % of the average sensitivity in 28 landmarks.

Adsorption of molecular additive onto lead halide perovskite surfaces: A computational study on Lewis base thiophene additive passivation

NASA Astrophysics Data System (ADS)

Zhang, Lei; Yu, Fengxi; Chen, Lihong; Li, Jingfa

2018-06-01

Organic additives, such as the Lewis base thiophene, have been successfully applied to passivate halide perovskite surfaces, improving the stability and properties of perovskite devices based on CH3NH3PbI3. Yet, the detailed nanostructure of the perovskite surface passivated by additives and the mechanisms of such passivation are not well understood. This study presents a nanoscopic view on the interfacial structure of an additive/perovskite interface, consisting of a Lewis base thiophene molecular additive and a lead halide perovskite surface substrate, providing insights on the mechanisms that molecular additives can passivate the halide perovskite surfaces and enhance the perovskite-based device performance. Molecular dynamics study on the interactions between water molecules and the perovskite surfaces passivated by the investigated additive reveal the effectiveness of employing the molecular additives to improve the stability of the halide perovskite materials. The additive/perovskite surface system is further probed via molecular engineering the perovskite surfaces. This study reveals the nanoscopic structure-property relationships of the halide perovskite surface passivated by molecular additives, which helps the fundamental understanding of the surface/interface engineering strategies for the development of halide perovskite based devices.

A comparison study: image-based vs signal-based retrospective gating on microCT

NASA Astrophysics Data System (ADS)

Liu, Xuan; Salmon, Phil L.; Laperre, Kjell; Sasov, Alexander

2017-09-01

Retrospective gating on animal studies with microCT has gained popularity in recent years. Previously, we use ECG signals for cardiac gating and breathing airflow or video signals of abdominal motion for respiratory gating. This method is adequate and works well for most applications. However, through the years, researchers have noticed some pitfalls in the method. For example, the additional signal acquisition step may increase failure rate in practice. X-Ray image-based gating, on the other hand, does not require any extra step in the scanning. Therefore we investigate imagebased gating techniques. This paper presents a comparison study of the image-based versus signal-based approach to retrospective gating. The two application areas we have studied are respiratory and cardiac imaging for both rats and mice. Image-based respiratory gating on microCT is relatively straightforward and has been done by several other researchers and groups. This method retrieves an intensity curve of a region of interest (ROI) placed in the lung area on all projections. From scans on our systems based on step-and-shoot scanning mode, we confirm that this method is very effective. A detailed comparison between image-based and signal-based gating methods is given. For cardiac gating, breathing motion is not negligible and has to be dealt with. Another difficulty in cardiac gating is the relatively smaller amplitude of cardiac movements comparing to the respirational movements, and the higher heart rate. Higher heart rate requires high speed image acquisition. We have been working on our systems to improve the acquisition speed. A dual gating technique has been developed to achieve adequate cardiac imaging.

Downstream Imaging Utilization After Emergency Department Ultrasound Interpreted by Radiologists Versus Nonradiologists: A Medicare Claims-Based Study.

PubMed

Allen, Bibb; Carrol, L Van; Hughes, Danny R; Hemingway, Jennifer; Duszak, Richard; Rosenkrantz, Andrew B

2017-04-01

To study differences in imaging utilization downstream to initial emergency department (ED) ultrasound examinations interpreted by radiologists versus nonradiologists. Using 5% Medicare Research Identifiable Files from 2009 to 2014, we identified episodes where the place of service was "emergency room hospital" and the patient also underwent an ultrasound examination. We determined whether the initial ultrasound was interpreted by a radiologist or nonradiologist and then summed all additional imaging events occurring within 7, 14, and 30 days of each initial ED ultrasound. For each year and each study window, we calculated the mean number of downstream imaging procedures by specialty group. Of 200,357 ED ultrasound events, 163,569 (81.6%) were interpreted by radiologists and 36,788 (18.4%) by nonradiologists. Across all study years, ED patients undergoing ultrasound examinations interpreted by nonradiologists underwent 1.08, 1.22, and 1.34 additional diagnostic imaging studies at 7, 14, and 30 days, respectively (P < .01) compared with when the initial ultrasound examination was interpreted by a radiologist. From 2010 to 2014, the volume of downstream imaging for both radiologists and nonradiologists significantly decreased, with each year resulting in 0.08 fewer imaging examinations (P < .001) 14 days after the ED ultrasound event. Despite that decline, differences in downstream imaging between radiologists and nonradiologists persisted over time. Downstream imaging after an initial ED ultrasound is significantly reduced when the ultrasound examination is interpreted by a radiologist rather than a nonradiologist. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Animal imaging studies of potential brain damage

NASA Astrophysics Data System (ADS)

Gatley, S. J.; Vazquez, M. E.; Rice, O.

To date, animal studies have not been able to predict the likelihood of problems in human neurological health due to HZE particle exposure during space missions outside the Earth's magnetosphere. In ongoing studies in mice, we have demonstrated that cocaine stimulated locomotor activity is reduced by a moderate dose (120 cGy) of 1 GeV 56Fe particles. We postulate that imaging experiments in animals may provide more sensitive and earlier indicators of damage due to HZE particles than behavioral tests. Since the small size of the mouse brain is not well suited to the spatial resolution offered by microPET, we are now repeating some of our studies in a rat model. We anticipate that this will enable us to identify imaging correlates of behavioral endpoints. A specific hypothesis of our studies is that changes in the metabolic rate for glucose in striatum of animals will be correlated with alterations in locomotor activity. We will also evaluate whether the neuroprotective drug L-deprenyl reduces the effect of radiation on locomotor activity. In addition, we will conduct microPET studies of brain monoamine oxidase A and monoamine oxidase B in rats before and at various times after irradiation with HZE particles. The hypothesis is that monoamine oxidase A, which is located in nerve terminals, will be unchanged or decreased after irradiation, while monoamine oxidase B, which is located in glial cells, will be increased after irradiation. Neurochemical effects that could be measured using PET could in principle be applied in astronauts, in terms of detecting and monitoring subtle neurological damage that might have occurred during long space missions. More speculative uses of PET are in screening candidates for prolonged space missions (for example, for adequate reserve in critical brain circuits) and in optimizing medications to treat impairments after missions.

Seismic imaging of post-glacial sediments - test study before Spitsbergen expedition

NASA Astrophysics Data System (ADS)

Szalas, Joanna; Grzyb, Jaroslaw; Majdanski, Mariusz

2017-04-01

This work presents results of the analysis of reflection seismic data acquired from testing area in central Poland. For this experiment we used total number of 147 vertical component seismic stations (DATA-CUBE and Reftek "Texan") with accelerated weight drop (PEG-40). The profile was 350 metres long. It is a part of pilot study for future research project on Spitsbergen. The purpose of the study is to recognise the characteristics of seismic response of post-glacial sediments in order to design the most adequate survey acquisition parameters and processing sequence for data from Spitsbergen. Multiple tests and comparisons have been performed to obtain the best possible quality of seismic image. In this research we examine the influence of receiver interval size, front mute application and surface wave attenuation attempts. Although seismic imaging is the main technique we are planning to support this analysis with additional data from traveltime tomography, MASW and other a priori information.

Multimodality imaging probe for positron emission tomography and fluorescence imaging studies.

PubMed

Pandey, Suresh K; Kaur, Jasmeet; Easwaramoorthy, Balu; Shah, Ankur; Coleman, Robert; Mukherjee, Jogeshwar

2014-01-01

Our goal is to develop multimodality imaging agents for use in cell tracking studies by positron emission tomography (PET) and optical imaging (OI). For this purpose, bovine serum albumin (BSA) was complexed with biotin (histologic studies), 5(6)-carboxyfluorescein, succinimidyl ester (FAM SE) (OI studies), and diethylenetriamine pentaacetic acid (DTPA) for chelating gallium 68 (PET studies). For synthesis of BSA-biotin-FAM-DTPA, BSA was coupled to (+)-biotin N-hydroxysuccinimide ester (biotin-NHSI). BSA-biotin was treated with DTPA-anhydride and biotin-BSA-DTPA was reacted with FAM. The biotin-BSA-DTPA-FAM was reacted with gallium chloride 3 to 5 mCi eluted from the generator using 0.1 N HCl and was passed through basic resin (AG 11 A8) and 150 μCi (100 μL, pH 7-8) was incubated with 0.1 mg of FAM conjugate (100 μL) at room temperature for 15 minutes to give 68Ga-BSA-biotin-DTPA-FAM. A shaved C57 black mouse was injected with FAM conjugate (50 μL) at one flank and FAM-68Ga (50 μL, 30 μCi) at the other. Immediately after injection, the mouse was placed in a fluorescence imaging system (Kodak In-Vivo F, Bruker Biospin Co., Woodbridge, CT) and imaged (λex: 465 nm, λem: 535 nm, time: 8 seconds, Xenon Light Source, Kodak). The same mouse was then placed under an Inveon microPET scanner (Siemens Medical Solutions, Knoxville, TN) injected (intravenously) with 25 μCi of 18F and after a half-hour (to allow sufficient bone uptake) was imaged for 30 minutes. Molecular weight determined using matrix-associated laser desorption ionization (MALDI) for the BSA sample was 66,485 Da and for biotin-BSA was 67,116 Da, indicating two biotin moieties per BSA molecule; for biotin-BSA-DTPA was 81,584 Da, indicating an average of 30 DTPA moieties per BSA molecule; and for FAM conjugate was 82,383 Da, indicating an average of 1.7 fluorescent moieties per BSA molecule. Fluorescence imaging clearly showed localization of FAM conjugate and FAM-68Ga at respective flanks of the mouse

Predicting High Imaging Utilization Based on Initial Radiology Reports: A Feasibility Study of Machine Learning.

PubMed

Hassanpour, Saeed; Langlotz, Curtis P

2016-01-01

Imaging utilization has significantly increased over the last two decades, and is only recently showing signs of moderating. To help healthcare providers identify patients at risk for high imaging utilization, we developed a prediction model to recognize high imaging utilizers based on their initial imaging reports. The prediction model uses a machine learning text classification framework. In this study, we used radiology reports from 18,384 patients with at least one abdomen computed tomography study in their imaging record at Stanford Health Care as the training set. We modeled the radiology reports in a vector space and trained a support vector machine classifier for this prediction task. We evaluated our model on a separate test set of 4791 patients. In addition to high prediction accuracy, in our method, we aimed at achieving high specificity to identify patients at high risk for high imaging utilization. Our results (accuracy: 94.0%, sensitivity: 74.4%, specificity: 97.9%, positive predictive value: 87.3%, negative predictive value: 95.1%) show that a prediction model can enable healthcare providers to identify in advance patients who are likely to be high utilizers of imaging services. Machine learning classifiers developed from narrative radiology reports are feasible methods to predict imaging utilization. Such systems can be used to identify high utilizers, inform future image ordering behavior, and encourage judicious use of imaging. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Magnetic resonance imaging study of eye congenital birth defects in mouse model

PubMed Central

Tucker, Zachary; Mongan, Maureen; Meng, Qinghang; Xia, Ying

2017-01-01

Purpose Embryonic eyelid closure is a well-documented morphogenetic episode in mammalian eye development. Detection of eyelid closure defect in humans is a major challenge because eyelid closure and reopen occur entirely in utero. As a consequence, congenital eye defects that are associated with failure of embryonic eyelid closure remain unknown. To fill the gap, we developed a mouse model of defective eyelid closure. This preliminary work demonstrates that the magnetic resonance imaging (MRI) approach can be used for the detection of extraocular muscle abnormalities in the mouse model. Methods Mice with either normal (Map3k1+/−) or defective (Map3k1−/−) embryonic eyelid closure were used in this study. Images of the extraocular muscles were obtained with a 9.4 T high resolution microimaging MRI system. The extraocular muscles were identified, segmented, and measured in each imaging slice using an in-house program. Results In agreement with histological findings, the imaging data show that mice with defective embryonic eyelid closure develop less extraocular muscle than normal mice. In addition, the size of the eyeballs was noticeably reduced in mice with defective embryonic eyelid closure. Conclusions We demonstrated that MRI can potentially be used for the study of extraocular muscle in the mouse model of the eye open-at-birth defect, despite the lack of specificity of muscle group provided by the current imaging resolution. PMID:28848319

Pediatric chest imaging.

PubMed

Gross, G W

1992-10-01

The highlight of recent articles published on pediatric chest imaging is the potential advantage of digital imaging of the infant's chest. Digital chest imaging allows accurate determination of functional residual capacity as well as manipulation of the image to highlight specific anatomic features. Reusable photostimulable phosphor imaging systems provide wide imaging latitude and lower patient dose. In addition, digital radiology permits multiple remote-site viewing on monitor displays. Several excellent reviews of the imaging features of various thoracic abnormalities and the application of newer imaging modalities, such as ultrafast CT and MR imaging to the pediatric chest, are additional highlights.

The impact of using visual images of the body within a personalized health risk assessment: an experimental study.

PubMed

Hollands, Gareth J; Marteau, Theresa M

2013-05-01

To examine the motivational impact of the addition of a visual image to a personalized health risk assessment and the underlying cognitive and emotional mechanisms. An online experimental study in which participants (n = 901; mean age = 27.2 years; 61.5% female) received an assessment and information focusing on the health implications of internal body fat and highlighting the protective benefits of physical activity. Participants were randomized to receive this in either (a) solely text form (control arm) or (b) text plus a visual image of predicted internal body fat (image arm). Participants received information representing one of three levels of health threat, determined by how physically active they were: high, moderate or benign. Main outcome measures were physical activity intentions (assessed pre- and post-intervention), worry, coherence and believability of the information. Intentions to undertake recommended levels of physical activity were significantly higher in the image arm, but only amongst those participants who received a high-threat communication. Believability of the results received was greater in the image arm and mediated the intervention effect on intentions. The addition of a visual image to a risk assessment led to small but significant increases in intentions to undertake recommended levels of physical activity in those at increased health risk. Limitations of the study and implications for future research are discussed. What is already known on this subject? Health risk information that is personalized to the individual may more strongly motivate risk-reducing behaviour change. Little prior research attention has been paid specifically to the motivational impact of personalized visual images and underlying mechanisms. What does this study add? In an experimental design, it is shown that receipt of visual images increases intentions to engage in risk-reducing behaviour, although only when a significant level of threat is presented. The

An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes

NASA Astrophysics Data System (ADS)

Calta, Nicholas P.; Wang, Jenny; Kiss, Andrew M.; Martin, Aiden A.; Depond, Philip J.; Guss, Gabriel M.; Thampy, Vivek; Fong, Anthony Y.; Weker, Johanna Nelson; Stone, Kevin H.; Tassone, Christopher J.; Kramer, Matthew J.; Toney, Michael F.; Van Buuren, Anthony; Matthews, Manyalibo J.

2018-05-01

In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results using Ti-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at the Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a ˜1.1 μm effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a ˜50 × 100 μm area. We also discuss the utility of these measurements for model validation and process improvement.

An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes.

PubMed

Calta, Nicholas P; Wang, Jenny; Kiss, Andrew M; Martin, Aiden A; Depond, Philip J; Guss, Gabriel M; Thampy, Vivek; Fong, Anthony Y; Weker, Johanna Nelson; Stone, Kevin H; Tassone, Christopher J; Kramer, Matthew J; Toney, Michael F; Van Buuren, Anthony; Matthews, Manyalibo J

2018-05-01

In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results using Ti-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at the Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a ∼1.1 μm effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a ∼50 × 100 μm area. We also discuss the utility of these measurements for model validation and process improvement.

Clinical study of imaging skin cancer margins using polarized light imaging

NASA Astrophysics Data System (ADS)

Samatham, Ravikant; Lee, Ken; Jacques, Steven L.

2012-02-01

Skin cancer is most commons type of cancer in United States that occur on sun-exposed cosmetically sensitive areas like face, neck, and forearms. Surgical excision of skin cancer is challenging as more than one-third the actual margins extend beyond the clinically determined margins. Polarized light camera (polCAM) provides images of the superficial layers of the tissue with enhanced contrast which was used to image skin cancer margins. In a NIH-funded pilot study polCAM was used to image skin cancer in patients undergoing Mohs micrographic surgery for skin cancer. Polarized light imaging utilizes the polarization properties of light to create an image of a lesion comprised only of light scattering from the superficial layers of the skin which yields a characteristic "fabric pattern" of the putative lesion and the surrounding normal tissue. In several case studies conducted with a system developed for the clinic, we have found that skin cancer disrupts this fabric pattern, allowing the doctor a new means of identifying the margins of the lesion. Data is acquired before the patient underwent surgery. The clinically determined skin cancer margins were compared with margins determined by examination of the polCAM images. The true margins were provided by the dermatophathologist on examination of the frozen sections. Our initial data suggests that the contrast due to polarization changes associated with cancerous lesions can elucidate margins that were not recognized by the surgeon under normal conditions but were later confirmed by the pathologist.

Opto-acoustic image fusion technology for diagnostic breast imaging in a feasibility study

NASA Astrophysics Data System (ADS)

Zalev, Jason; Clingman, Bryan; Herzog, Don; Miller, Tom; Ulissey, Michael; Stavros, A. T.; Oraevsky, Alexander; Lavin, Philip; Kist, Kenneth; Dornbluth, N. C.; Otto, Pamela

2015-03-01

Functional opto-acoustic (OA) imaging was fused with gray-scale ultrasound acquired using a specialized duplex handheld probe. Feasibility Study findings indicated the potential to more accurately characterize breast masses for cancer than conventional diagnostic ultrasound (CDU). The Feasibility Study included OA imagery of 74 breast masses that were collected using the investigational Imagio® breast imaging system. Superior specificity and equal sensitivity to CDU was demonstrated, suggesting that OA fusion imaging may potentially obviate the need for negative biopsies without missing cancers in a certain percentage of breast masses. Preliminary results from a 100 subject Pilot Study are also discussed. A larger Pivotal Study (n=2,097 subjects) is underway to confirm the Feasibility Study and Pilot Study findings.

Performance characteristics of UV imaging instrumentation for diffusion, dissolution and release testing studies.

PubMed

Jensen, Sabrine S; Jensen, Henrik; Goodall, David M; Østergaard, Jesper

2016-11-30

UV imaging is capable of providing spatially and temporally resolved absorbance measurements, which is highly beneficial in drug diffusion, dissolution and release testing studies. For optimal planning and design of experiments, knowledge about the capabilities and limitations of the imaging system is required. The aim of this study was to characterize the performance of two commercially available UV imaging systems, the D100 and SDI. Lidocaine crystals, lidocaine containing solutions, and gels were applied in the practical assessment of the UV imaging systems. Dissolution of lidocaine from single crystals into phosphate buffer and 0.5% (w/v) agarose hydrogel at pH 7.4 was investigated to shed light on the importance of density gradients under dissolution conditions in the absence of convective flow. In addition, the resolution of the UV imaging systems was assessed by the use of grids. Resolution was found to be better in the vertical direction than the horizontal direction, consistent with the illumination geometry. The collimating lens in the SDI imaging system was shown to provide more uniform light intensity across the UV imaging area and resulted in better resolution as compared to the D100 imaging system (a system without a lens). Under optimal conditions, the resolution was determined to be 12.5 and 16.7 line pairs per mm (lp/mm) corresponding to line widths of 40μm and 30μm in the horizontal and vertical direction, respectively. Overall, the performance of the UV imaging systems was shown mainly to depend on collimation of light, the light path, the positioning of the object relative to the line of 100μm fibres which forms the light source, and the distance of the object from the sensor surface. Copyright © 2016 Elsevier B.V. All rights reserved.

Robotics and dynamic image analysis for studies of gene expression in plant tissues.

PubMed

Hernandez-Garcia, Carlos M; Chiera, Joseph M; Finer, John J

2010-05-05

Gene expression in plant tissues is typically studied by destructive extraction of compounds from plant tissues for in vitro analyses. The methods presented here utilize the green fluorescent protein (gfp) gene for continual monitoring of gene expression in the same pieces of tissues, over time. The gfp gene was placed under regulatory control of different promoters and introduced into lima bean cotyledonary tissues via particle bombardment. Cotyledons were then placed on a robotic image collection system, which consisted of a fluorescence dissecting microscope with a digital camera and a 2-dimensional robotics platform custom-designed to allow secure attachment of culture dishes. Images were collected from cotyledonary tissues every hour for 100 hours to generate expression profiles for each promoter. Each collected series of 100 images was first subjected to manual image alignment using ImageReady to make certain that GFP-expressing foci were consistently retained within selected fields of analysis. Specific regions of the series measuring 300 x 400 pixels, were then selected for further analysis to provide GFP Intensity measurements using ImageJ software. Batch images were separated into the red, green and blue channels and GFP-expressing areas were identified using the threshold feature of ImageJ. After subtracting the background fluorescence (subtraction of gray values of non-expressing pixels from every pixel) in the respective red and green channels, GFP intensity was calculated by multiplying the mean grayscale value per pixel by the total number of GFP-expressing pixels in each channel, and then adding those values for both the red and green channels. GFP Intensity values were collected for all 100 time points to yield expression profiles. Variations in GFP expression profiles resulted from differences in factors such as promoter strength, presence of a silencing suppressor, or nature of the promoter. In addition to quantification of GFP intensity, the

The study of fresh-water lake ice using multiplexed imaging radar

USGS Publications Warehouse

Leonard, Bryan M.; Larson, R.W.

1975-01-01

The study of ice in the upper Great Lakes, both from the operational and the scientific points of view, is receiving continued attention. Quantitative and qualitative field work is being conducted to provide the needed background for accurate interpretation of remotely sensed data. The data under discussion in this paper were obtained by a side-looking multiplexed airborne radar (SLAR) supplemented with ground-truth data.Because of its ability to penetrate adverse weather, radar is an especially important instrument for monitoring ice in the upper Great Lakes. It has previously been shown that imaging radars can provide maps of ice cover in these areas. However, questions concerning both the nature of the surfaces reflecting radar energy and the interpretation of the radar imagery continually arise.Our analysis of ice in Whitefish Bay (Lake Superior) indicates that the combination of the ice/water interlace and the ice/air interface is the major contributor to the radar backscatter as seen on the imagery At these frequencies the ice has a very low relative dielectric permittivity (< 3.0) and a low loss tangent Thus, this ice is somewhat transparent to the energy used by the imaging SLAR system. The ice types studied include newly formed black ice, pancake ice, and frozen and consolidated pack and brash ice.Although ice thickness cannot be measured directly from the received signals, it is suspected that by combining the information pertaining to radar backscatter with data on the meteorological and sea-state history of the area, together with some basic ground truth, better estimates of the ice thickness may be provided. In addition, certain ice features (e.g. ridges, ice-foot formation, areas of brash ice) may be identified with reasonable confidence. There is a continued need for additional ground work to verify the validity of imaging radars for these types of interpretations.

Imaging of idle breast implants with ultrasound-strain elastography- A first experimental study to establish criteria for accurate imaging of idle implants via ultrasound-strain elastography.

PubMed

Kuehlmann, Britta; Prantl, Lukas; Michael Jung, Ernst

2016-01-01

To investigate whether there are fundamental sonographic and elastographic criteria to precisely assess different surfaces and fillings of idle breast implants and to determine their most distinctive parameters. This was a comparative study of different unused breast implant materials, neighter in animals nor in humans. This knowledge should be transferred in vivo to develop an objective measurement tool. Nine idle breast implants-silicone and polyurethane (PU)-were examined in an experimental study by using ultrasound B-mode with tissue harmonic imaging (THI), speckle reduction imaging (SRI, level 0-4), cross-beam (CB, low, medium, high), photopic and the colour coded ultrasound-strain elastography with a multifrequency probe (9-15 MHz).Using a standardised protocol the implants' centre as well as the edge were analysed by one experienced examiner. Two independent readers performed analysis and evaluation. For image interpretation a score was created (score 0:inadequate image, score 5:best image quality). The highest score result for the centre was achieved by using ultrasound with B-mode in addition with CB level medium, SRI level 2, THI and photopic (mean:3.22±SD:1.56), but without any statistic significant difference (t-value = 0.71). With elastography the implants' edge in general was represented without disruptive artefacts (3.89±0.60) with statistic significant difference (t-value = 5.29). Implants filled with inner cohesive silicone gel II° showed best imaging conditions for their centre via ultrasound (5±0) as well as for their edge via elastography (4.50±0.71). Ultrasound-strain elastography and high resolution ultrasound represent a valuable measurement tool to evaluate different properties of idle breast implants. These modified ultrasound examinations could be an additional help for clinical investigations and be correlated with Baker's Classification.

Single Particle Analysis by Combined Chemical Imaging to Study Episodic Air Pollution Events in Vienna

NASA Astrophysics Data System (ADS)

Ofner, Johannes; Eitenberger, Elisabeth; Friedbacher, Gernot; Brenner, Florian; Hutter, Herbert; Schauer, Gerhard; Kistler, Magdalena; Greilinger, Marion; Lohninger, Hans; Lendl, Bernhard; Kasper-Giebl, Anne

2017-04-01

The aerosol composition of a city like Vienna is characterized by a complex interaction of local emissions and atmospheric input on a regional and continental scale. The identification of major aerosol constituents for basic source appointment and air quality issues needs a high analytical effort. Exceptional episodic air pollution events strongly change the typical aerosol composition of a city like Vienna on a time-scale of few hours to several days. Analyzing the chemistry of particulate matter from these events is often hampered by the sampling time and related sample amount necessary to apply the full range of bulk analytical methods needed for chemical characterization. Additionally, morphological and single particle features are hardly accessible. Chemical Imaging evolved to a powerful tool for image-based chemical analysis of complex samples. As a complementary technique to bulk analytical methods, chemical imaging can address a new access to study air pollution events by obtaining major aerosol constituents with single particle features at high temporal resolutions and small sample volumes. The analysis of the chemical imaging datasets is assisted by multivariate statistics with the benefit of image-based chemical structure determination for direct aerosol source appointment. A novel approach in chemical imaging is combined chemical imaging or so-called multisensor hyperspectral imaging, involving elemental imaging (electron microscopy-based energy dispersive X-ray imaging), vibrational imaging (Raman micro-spectroscopy) and mass spectrometric imaging (Time-of-Flight Secondary Ion Mass Spectrometry) with subsequent combined multivariate analytics. Combined chemical imaging of precipitated aerosol particles will be demonstrated by the following examples of air pollution events in Vienna: Exceptional episodic events like the transformation of Saharan dust by the impact of the city of Vienna will be discussed and compared to samples obtained at a high alpine

[Elastography as an additional tool in breast sonography. Technical principles and clinical applications].

PubMed

Rjosk-Dendorfer, D; Reichelt, A; Clevert, D-A

2014-03-01

In recent years the use of elastography in addition to sonography has become a routine clinical tool for the characterization of breast masses. Whereas free hand compression elastography results in qualitative imaging of tissue stiffness due to induced compression, shear wave elastography displays quantitative information of tissue displacement. Recent studies have investigated the use of elastography in addition to sonography and improvement of specificity in differentiating benign from malignant breast masses could be shown. Therefore, additional use of elastography could help to reduce the number of unnecessary biopsies in benign breast lesions especially in category IV lesions of the ultrasound breast imaging reporting data system (US-BI-RADS).

Image splitting and remapping method for radiological image compression

NASA Astrophysics Data System (ADS)

Lo, Shih-Chung B.; Shen, Ellen L.; Mun, Seong K.

1990-07-01

A new decomposition method using image splitting and gray-level remapping has been proposed for image compression, particularly for images with high contrast resolution. The effects of this method are especially evident in our radiological image compression study. In our experiments, we tested the impact of this decomposition method on image compression by employing it with two coding techniques on a set of clinically used CT images and several laser film digitized chest radiographs. One of the compression techniques used was full-frame bit-allocation in the discrete cosine transform domain, which has been proven to be an effective technique for radiological image compression. The other compression technique used was vector quantization with pruned tree-structured encoding, which through recent research has also been found to produce a low mean-square-error and a high compression ratio. The parameters we used in this study were mean-square-error and the bit rate required for the compressed file. In addition to these parameters, the difference between the original and reconstructed images will be presented so that the specific artifacts generated by both techniques can be discerned by visual perception.

Additive controlled synthesis of gold nanorods (GNRs) for two-photon luminescence imaging of cancer cells

NASA Astrophysics Data System (ADS)

Zhu, Jing; Yong, Ken-Tye; Roy, Indrajit; Hu, Rui; Ding, Hong; Zhao, Lingling; Swihart, Mark T.; He, Guang S.; Cui, Yiping; Prasad, Paras N.

2010-07-01

Gold nanorods (GNRs) with a longitudinal surface plasmon resonance peak that is tunable from 600 to 1100 nm have been fabricated in a cetyl trimethylammoniumbromide (CTAB) micellar medium using hydrochloric acid and silver nitrate as additives to control their shape and size. By manipulating the concentrations of silver nitrate and hydrochloric acid, the aspect ratio of the GNRs was reliably and reproducibly tuned from 2.5 to 8. The GNRs were first coated with polyelectrolyte multilayers and then bioconjugated to transferrin (Tf) to target pancreatic cancer cells. Two-photon imaging excited from the bioconjugated GNRs demonstrated receptor-mediated uptake of the bioconjugates into Panc-1 cells, overexpressing the transferrin receptor (TfR). The bioconjugated GNR formulation exhibited very low toxicity, suggesting that it is biocompatible and potentially suitable for targeted two-photon bioimaging.

Penn State's Visual Image User Study

ERIC Educational Resources Information Center

Pisciotta, Henry A.; Dooris, Michael J.; Frost, James; Halm, Michael

2005-01-01

The Visual Image User Study (VIUS), an extensive needs assessment project at Penn State University, describes academic users of pictures and their perceptions. These findings outline the potential market for digital images and list the likely determinates of whether or not a system will be used. They also explain some key user requirements for…

The collection of images of an insulator taken outdoors in varying lighting conditions with additional laser spots.

PubMed

Tomaszewski, Michał; Ruszczak, Bogdan; Michalski, Paweł

2018-06-01

Electrical insulators are elements of power lines that require periodical diagnostics. Due to their location on the components of high-voltage power lines, their imaging can be cumbersome and time-consuming, especially under varying lighting conditions. Insulator diagnostics with the use of visual methods may require localizing insulators in the scene. Studies focused on insulator localization in the scene apply a number of methods, including: texture analysis, MRF (Markov Random Field), Gabor filters or GLCM (Gray Level Co-Occurrence Matrix) [1], [2]. Some methods, e.g. those which localize insulators based on colour analysis [3], rely on object and scene illumination, which is why the images from the dataset are taken under varying lighting conditions. The dataset may also be used to compare the effectiveness of different methods of localizing insulators in images. This article presents high-resolution images depicting a long rod electrical insulator under varying lighting conditions and against different backgrounds: crops, forest and grass. The dataset contains images with visible laser spots (generated by a device emitting light at the wavelength of 532 nm) and images without such spots, as well as complementary data concerning the illumination level and insulator position in the scene, the number of registered laser spots, and their coordinates in the image. The laser spots may be used to support object-localizing algorithms, while the images without spots may serve as a source of information for those algorithms which do not need spots to localize an insulator.

An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calta, Nicholas P.; Wang, Jenny; Kiss, Andrew M.

In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results using Ti-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at themore » Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a ~1.1 μm effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a ~50 × 100 μm area. In conclusion, we also discuss the utility of these measurements for model validation and process improvement.« less

An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes

DOE PAGES

Calta, Nicholas P.; Wang, Jenny; Kiss, Andrew M.; ...

2018-05-01

In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results using Ti-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at themore » Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a ~1.1 μm effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a ~50 × 100 μm area. In conclusion, we also discuss the utility of these measurements for model validation and process improvement.« less

Image Gallery

MedlinePlus

... R S T U V W X Y Z Image Gallery Share: The Image Gallery contains high-quality digital photographs available from ... Select a category below to view additional thumbnail images. Images are available for direct download in 2 ...

Pilot Study of 64Cu(I) for PET Imaging of Melanoma

DOE PAGES

Jiang, Lei; Tu, Yingfeng; Hu, Xiang; ...

2017-05-31

Currently, 64Cu(II) labeled tracers including 64CuCl 2 have been widely applied in the research of molecular imaging and therapy. Human copper transporter 1 (hCTR1) is the major high affinity copper influx transporter in mammalian cells, and specially responsible for the transportation of Cu(I) not Cu(II). Thus, we investigated the feasible application of 64Cu(I) for PET imaging. 64Cu(II) was reduced to 64Cu(I) with the existence of sodium L-ascorbate, DL-Dithiothreitol or cysteine. Cell uptake and efflux assay was investigated using B16F10 and A375 cell lines, respectively. Small animal PET and biodistribution studies were performed in both B16F10 and A375 tumor-bearing mice. Comparedmore » with 64Cu(II), 64Cu(I) exhibited higher cellular uptake by melanoma, which testified CTR1 specially influx of Cu(I). But, due to oxidation reaction in vivo, no significant difference between 64Cu(I) and 64Cu(II) was observed through PET images and biodistribution. In addition, radiation absorbed doses for major tissues of human were calculated based on the mouse biodistribution. Radiodosimetry calculations for 64/67Cu(I) and 64/67Cu(II) were similar, which suggested that although melanoma were with high radiation absorbed doses, high radioactivity accumulation by liver and kidney should be noticed for the further application. Thus, 64Cu(I) should be further studied to evaluate it as a PET imaging radiotracer.« less

Pilot Study of 64Cu(I) for PET Imaging of Melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Lei; Tu, Yingfeng; Hu, Xiang

Currently, 64Cu(II) labeled tracers including 64CuCl 2 have been widely applied in the research of molecular imaging and therapy. Human copper transporter 1 (hCTR1) is the major high affinity copper influx transporter in mammalian cells, and specially responsible for the transportation of Cu(I) not Cu(II). Thus, we investigated the feasible application of 64Cu(I) for PET imaging. 64Cu(II) was reduced to 64Cu(I) with the existence of sodium L-ascorbate, DL-Dithiothreitol or cysteine. Cell uptake and efflux assay was investigated using B16F10 and A375 cell lines, respectively. Small animal PET and biodistribution studies were performed in both B16F10 and A375 tumor-bearing mice. Comparedmore » with 64Cu(II), 64Cu(I) exhibited higher cellular uptake by melanoma, which testified CTR1 specially influx of Cu(I). But, due to oxidation reaction in vivo, no significant difference between 64Cu(I) and 64Cu(II) was observed through PET images and biodistribution. In addition, radiation absorbed doses for major tissues of human were calculated based on the mouse biodistribution. Radiodosimetry calculations for 64/67Cu(I) and 64/67Cu(II) were similar, which suggested that although melanoma were with high radiation absorbed doses, high radioactivity accumulation by liver and kidney should be noticed for the further application. Thus, 64Cu(I) should be further studied to evaluate it as a PET imaging radiotracer.« less

Synchrotron radiation imaging is a powerful tool to image brain microvasculature.

PubMed

Zhang, Mengqi; Peng, Guanyun; Sun, Danni; Xie, Yuanyuan; Xia, Jian; Long, Hongyu; Hu, Kai; Xiao, Bo

2014-03-01

Synchrotron radiation (SR) imaging is a powerful experimental tool for micrometer-scale imaging of microcirculation in vivo. This review discusses recent methodological advances and findings from morphological investigations of cerebral vascular networks during several neurovascular pathologies. In particular, it describes recent developments in SR microangiography for real-time assessment of the brain microvasculature under various pathological conditions in small animal models. It also covers studies that employed SR-based phase-contrast imaging to acquire 3D brain images and provide detailed maps of brain vasculature. In addition, a brief introduction of SR technology and current limitations of SR sources are described in this review. In the near future, SR imaging could transform into a common and informative imaging modality to resolve subtle details of cerebrovascular function.

SU-E-J-158: Audiovisual Biofeedback Reduces Image Artefacts in 4DCT: A Digital Phantom Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pollock, S; Kipritidis, J; Lee, D

2015-06-15

Purpose: Irregular breathing motion has a deleterious impact on 4DCT image quality. The breathing guidance system: audiovisual biofeedback (AVB) is designed to improve breathing regularity, however, its impact on 4DCT image quality has yet to be quantified. The purpose of this study was to quantify the impact of AVB on thoracic 4DCT image quality by utilizing the digital eXtended Cardiac Torso (XCAT) phantom driven by lung tumor motion patterns. Methods: 2D tumor motion obtained from 4 lung cancer patients under two breathing conditions (i) without breathing guidance (free breathing), and (ii) with guidance (AVB). There were two breathing sessions, yieldingmore » 8 tumor motion traces. This tumor motion was synchronized with the XCAT phantom to simulate 4DCT acquisitions under two acquisition modes: (1) cine mode, and (2) prospective respiratory-gated mode. Motion regularity was quantified by the root mean square error (RMSE) of displacement. The number of artefacts was visually assessed for each 4DCT and summed up for each breathing condition. Inter-session anatomic reproducibility was quantified by the mean absolute difference (MAD) between the Session 1 4DCT and Session 2 4DCT. Results: AVB improved tumor motion regularity by 30%. In cine mode, the number of artefacts was reduced from 61 in free breathing to 40 with AVB, in addition to AVB reducing the MAD by 34%. In gated mode, the number of artefacts was reduced from 63 in free breathing to 51 with AVB, in addition to AVB reducing the MAD by 23%. Conclusion: This was the first study to compare the impact of breathing guidance on 4DCT image quality compared to free breathing, with AVB reducing the amount of artefacts present in 4DCT images in addition to improving inter-session anatomic reproducibility. Results thus far suggest that breathing guidance interventions could have implications for improving radiotherapy treatment planning and interfraction reproducibility.« less

Comparison of 0.625-mm source computed tomographic images versus 5-mm thick reconstructed images in the evaluation for renal calculi in at-risk patients.

PubMed

Berkenblit, Robert; Hoenig, David; Lerer, Daniel; Moses, Melanie; Minsky, Lloyd

2013-02-01

CT has become a well-established modality in the evaluation of urinary calculi. The advent of multidetector CT (MDCT) scanners and submillimeter thick slice acquisitions has yielded CT images with even greater resolution. MDCT scanners allow for source data slice acquisition with submillimeter slice thickness. These source images can then be reconstructed to thicker slices for more convenient interpretation of the CT scan. Previous authors have looked at the effect of slice thickness on detection of urinary calculi. We investigated whether the thin slice source images yielded detection of additional stones and the potential significance of detecting these additional stones. Ninety-five consecutive patients who were referred to our outpatient imaging center for CT, with a clinical history placing them at risk for urinary calculi, were included in the study. In 49 (52%) of the 95 patients, more calculi were visualized using the 0.625-mm thick images than with the 5-mm thick images. In 34 (69%) of these 49 patients, the additional findings were thought to be "clinically significant," while in the remaining 15 (31%) patients, the additional findings were not thought to be clinically significant. In 46 (48%) of the 95 patients, there were no additional urinary calculi identified on the 0.625-mm thick images compared with that observed on 5-mm thick images. The results from this study encourage reviewing the thin slice source images of MDCTs in patients at risk for urinary calculi, because important clinical decisions may hinge on the additional findings made on these images.

A functional magnetic resonance imaging study of working memory abnormalities in schizophrenia.

PubMed

Johnson, Matthew R; Morris, Nicholas A; Astur, Robert S; Calhoun, Vince D; Mathalon, Daniel H; Kiehl, Kent A; Pearlson, Godfrey D

2006-07-01

Previous neuroimaging studies of working memory (WM) in schizophrenia, typically focusing on dorsolateral prefrontal cortex, yield conflicting results, possibly because of varied choice of tasks and analysis techniques. We examined neural function changes at several WM loads to derive a more complete picture of WM dysfunction in schizophrenia. We used a version of the Sternberg Item Recognition Paradigm to test WM function at five distinct loads. Eighteen schizophrenia patients and 18 matched healthy controls were scanned with functional magnetic resonance imaging at 3 Tesla. Patterns of both overactivation and underactivation in patients were observed depending on WM load. Patients' activation was generally less responsive to load changes than control subjects', and different patterns of between-group differences were observed for memory encoding and retrieval. In the specific case of successful retrieval, patients recruited additional neural circuits unused by control subjects. Behavioral effects were generally consistent with these imaging results. Differential findings of overactivation and underactivation may be attributable to patients' decreased ability to focus and allocate neural resources at task-appropriate levels. Additionally, differences between encoding and retrieval suggest that WM dysfunction may be manifested differently during the distinct phases of encoding, maintenance, and retrieval.

The Socio-Moral Image Database (SMID): A novel stimulus set for the study of social, moral and affective processes

PubMed Central

Bode, Stefan; Murawski, Carsten; Laham, Simon M.

2018-01-01

A major obstacle for the design of rigorous, reproducible studies in moral psychology is the lack of suitable stimulus sets. Here, we present the Socio-Moral Image Database (SMID), the largest standardized moral stimulus set assembled to date, containing 2,941 freely available photographic images, representing a wide range of morally (and affectively) positive, negative and neutral content. The SMID was validated with over 820,525 individual judgments from 2,716 participants, with normative ratings currently available for all images on affective valence and arousal, moral wrongness, and relevance to each of the five moral values posited by Moral Foundations Theory. We present a thorough analysis of the SMID regarding (1) inter-rater consensus, (2) rating precision, and (3) breadth and variability of moral content. Additionally, we provide recommendations for use aimed at efficient study design and reproducibility, and outline planned extensions to the database. We anticipate that the SMID will serve as a useful resource for psychological, neuroscientific and computational (e.g., natural language processing or computer vision) investigations of social, moral and affective processes. The SMID images, along with associated normative data and additional resources are available at https://osf.io/2rqad/. PMID:29364985

The Socio-Moral Image Database (SMID): A novel stimulus set for the study of social, moral and affective processes.

PubMed

Crone, Damien L; Bode, Stefan; Murawski, Carsten; Laham, Simon M

2018-01-01

A major obstacle for the design of rigorous, reproducible studies in moral psychology is the lack of suitable stimulus sets. Here, we present the Socio-Moral Image Database (SMID), the largest standardized moral stimulus set assembled to date, containing 2,941 freely available photographic images, representing a wide range of morally (and affectively) positive, negative and neutral content. The SMID was validated with over 820,525 individual judgments from 2,716 participants, with normative ratings currently available for all images on affective valence and arousal, moral wrongness, and relevance to each of the five moral values posited by Moral Foundations Theory. We present a thorough analysis of the SMID regarding (1) inter-rater consensus, (2) rating precision, and (3) breadth and variability of moral content. Additionally, we provide recommendations for use aimed at efficient study design and reproducibility, and outline planned extensions to the database. We anticipate that the SMID will serve as a useful resource for psychological, neuroscientific and computational (e.g., natural language processing or computer vision) investigations of social, moral and affective processes. The SMID images, along with associated normative data and additional resources are available at https://osf.io/2rqad/.

Impact of pediatric burn camps on participants' self esteem and body image: an empirical study.

PubMed

Bakker, Anne; Van der Heijden, Peter G M; Van Son, Maarten J M; Van de Schoot, Rens; Van Loey, Nancy E E

2011-12-01

This study focuses on possible effects of specialized summer camps on young burn survivors' self esteem and body image. Quantitative as well as qualitative measures was used. To study possible effects, a pretest-posttest comparison group design with a follow-up was employed. Self-report questionnaires were used to measure self esteem and body image in a burn camp group (n=83, 8-18 years) and in a comparison group of children with burns who did not attend a burn camp during the course of the study (n=90, 8-18 years). Additionally, burn camp participants and parents completed an evaluation form about benefits derived from burn camp. A small positive short-term effect of burn camp participation was found on the 'satisfaction with appearance' component of body image. Overall, participants and parents showed high appreciation of the burn camps and reported several benefits, particularly concerning meeting other young burn survivors. Albeit statistically modest, this is the first quantitative study to document on a significant short-term impact of burn camp on young burn survivors' body image. Implications of this result for future research and burn camp organization were discussed, including the strengths of residential camps for young burn survivors. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

Intrinsic and extrinsic effects on image memorability.

PubMed

Bylinskii, Zoya; Isola, Phillip; Bainbridge, Constance; Torralba, Antonio; Oliva, Aude

2015-11-01

Previous studies have identified that images carry the attribute of memorability, a predictive value of whether a novel image will be later remembered or forgotten. Here we investigate the interplay between intrinsic and extrinsic factors that affect image memorability. First, we find that intrinsic differences in memorability exist at a finer-grained scale than previously documented. Second, we test two extrinsic factors: image context and observer behavior. Building on prior findings that images that are distinct with respect to their context are better remembered, we propose an information-theoretic model of image distinctiveness. Our model can automatically predict how changes in context change the memorability of natural images. In addition to context, we study a second extrinsic factor: where an observer looks while memorizing an image. It turns out that eye movements provide additional information that can predict whether or not an image will be remembered, on a trial-by-trial basis. Together, by considering both intrinsic and extrinsic effects on memorability, we arrive at a more complete and fine-grained model of image memorability than previously available. Copyright © 2015 Elsevier Ltd. All rights reserved.

Magnetic resonance imaging for the study of mummies.

PubMed

Giovannetti, Giulio; Guerrini, Andrea; Carnieri, Emiliano; Salvadori, Piero A

2016-07-01

Nondestructive diagnostic imaging for mummies study has a long tradition and high-resolution images of the samples morphology have been extensively acquired by using computed tomography (CT). However, although in early reports no signal or image was obtained because of the low water content, mummy magnetic resonance imaging (MRI) was demonstrated able to generate images of such ancient specimens by using fast imaging techniques. Literature demonstrated the general feasibility of nonclinical MRI for visualizing historic human tissues, which is particularly interesting for archeology. More recently, multinuclear magnetic resonance spectroscopy (MRS) was demonstrated able to detect numerous organic biochemicals from such remains. Although the quality of these images is not yet comparable to that of clinical magnetic resonance (MR) images, and further research will be needed for determining the full capacity of MR in this topic, the information obtained with MR can be viewed as complementary to the one provided by CT and useful for paleoradiological studies of mummies. This work contains an overview of the state of art of the emerging uses of MRI in paleoradiology. Copyright © 2016 Elsevier Inc. All rights reserved.

Nuclear medicine and imaging research: Quantitative studies in radiopharmaceutical science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Copper, M.; Beck, R.N.

1991-06-01

During the past three years the program has undergone a substantial revitalization. There has been no significant change in the scientific direction of this grant, in which emphasis continues to be placed on developing new or improved methods of obtaining quantitative data from radiotracer imaging studies. However, considerable scientific progress has been made in the three areas of interest: Radiochemistry, Quantitative Methodologies, and Experimental Methods and Feasibility Studies, resulting in a sharper focus of perspective and improved integration of the overall scientific effort. Changes in Faculty and staff, including development of new collaborations, have contributed to this, as has acquisitionmore » of additional and new equipment and renovations and expansion of the core facilities. 121 refs., 30 figs., 2 tabs.« less

Electrostatic Levitation for Studies of Additive Manufactured Materials

NASA Technical Reports Server (NTRS)

SanSoucie, Michael P.; Rogers, Jan R.; Tramel, Terri

2014-01-01

The electrostatic levitation (ESL) laboratory at NASA's Marshall Space Flight Center is a unique facility for investigators studying high temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified. Electrostatic levitation minimizes gravitational effects and allows materials to be studied without contact with a container or instrumentation. The lab also has a high temperature emissivity measurement system, which provides normal spectral and normal total emissivity measurements at use temperature. The ESL lab has been instrumental in many pioneering materials investigations of thermophysical properties, e.g., creep measurements, solidification, triggered nucleation, and emissivity at high temperatures. Research in the ESL lab has already led to the development of advanced high temperature materials for aerospace applications, coatings for rocket nozzles, improved medical and industrial optics, metallic glasses, ablatives for reentry vehicles, and materials with memory. Modeling of additive manufacturing materials processing is necessary for the study of their resulting materials properties. In addition, the modeling of the selective laser melting processes and its materials property predictions are also underway. Unfortunately, there is very little data for the properties of these materials, especially of the materials in the liquid state. Some method to measure thermophysical properties of additive manufacturing materials is necessary. The ESL lab is ideal for these studies. The lab can provide surface tension and viscosity of molten materials, density measurements, emissivity measurements, and even creep strength measurements. The ESL lab can also determine melting temperature, surface temperatures, and phase transition temperatures of additive manufactured materials. This presentation will provide background on the ESL lab and its capabilities, provide an approach to using the ESL

Magnetic Resonance Imaging Studies of Process Rheology

DTIC Science & Technology

1990-08-14

a Twin - screw Extruder ................ 7 2.1.2 NMR Flow Imaging Studies ................................... 7U 2.2 Theoretical Modeling ...run at high production rates, mixed in a 50.8 mm fully intermeshing, co - rotating twin - screw off-line techniques of quality control may lead to very...Imaging Studies of............... A -1 Mixing in a Twin - Screw Extruder " B. "Stokesian Dynamics Simulation of Polyether-coated

Developing a Hypnotic Relaxation Intervention to Improve Body Image: A Feasibility Study.

PubMed

Cieslak, Alison; Elkins, Gary; Banerjee, Tanima; Marsack, Jessica; Hickman, Kimberly; Johnson, Alisa; Henry, Norah; Barton, Debra

2016-11-01

To determine the content, feasibility, and best outcome of a mind-body intervention involving self-directed hypnotic relaxation to target body image.
. A five-week, uncontrolled, unblinded feasibility intervention study.
. Behavioral therapy offices in Ann Arbor, Michigan, and Waco, Texas.
. 10 female breast cancer survivors and 1 breast and gynecologic cancer survivor. 
. Adult women with a history of breast and gynecologic cancer and no major psychiatric history were eligible. The intervention included four face-to-face sessions with a research therapist lasting 40-60 minutes, logged home practice, one telephone check-in call at week 5, and one intervention feedback telephone call to complete the study. Descriptive statistics and paired t-tests were used to test feasibility and content validity.
. Stress from body changes as measured by the Impact of Treatment Scale, sexual function as measured by the Female Sexual Function Index, and sexual self-image as measured by the Sexual Self-Schema Scale for women were the variables of interest.
. The intervention content was confirmed. Changes in scores from the baseline to week 5 suggested that stress from body changes decreased and sexual self-schema and function improved during the intervention. Nine of the 11 women were satisfied with the intervention, and all 11 indicated that their body image improved. 
. Hypnotic relaxation therapy shows promise for improving body image and, in doing so, improving sexual health in this population. Additional testing of this intervention is warranted.
. Hypnotic relaxation therapy is feasible to improve body image and sexual health in women diagnosed with cancer and may be an important intervention that could be offered by nurses and other behavioral therapists.

Synchrotron radiation imaging is a powerful tool to image brain microvasculature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Mengqi; Sun, Danni; Xie, Yuanyuan

2014-03-15

Synchrotron radiation (SR) imaging is a powerful experimental tool for micrometer-scale imaging of microcirculation in vivo. This review discusses recent methodological advances and findings from morphological investigations of cerebral vascular networks during several neurovascular pathologies. In particular, it describes recent developments in SR microangiography for real-time assessment of the brain microvasculature under various pathological conditions in small animal models. It also covers studies that employed SR-based phase-contrast imaging to acquire 3D brain images and provide detailed maps of brain vasculature. In addition, a brief introduction of SR technology and current limitations of SR sources are described in this review. Inmore » the near future, SR imaging could transform into a common and informative imaging modality to resolve subtle details of cerebrovascular function.« less

64Cu-PSMA-617 PET/CT Imaging of Prostate Adenocarcinoma: First In-Human Studies.

PubMed

Grubmüller, Bernhard; Baum, Richard P; Capasso, Enza; Singh, Aviral; Ahmadi, Yasaman; Knoll, Peter; Floth, Andreas; Righi, Sergio; Zandieh, Shahin; Meleddu, Carlo; Shariat, Shahrokh F; Klingler, Hans Christoph; Mirzaei, Siroos

2016-10-07

The prostate-specific membrane antigen (PSMA) is a cell surface protein, which is overexpressed in nearly all cases of prostate cancer (PCa). PET imaging with 68 Ga-PSMA-HBED-CC has recently found widespread application in the diagnosis of recurrent PCa. In this study, the diagnostic potential of 64 Cu-labeled PSMA ligand (PSMA-617) PET in patients with PCa has been investigated. The study was conducted simultaneously at two nuclear medicine centers, Austria (Vienna, Center 1) and Germany (Bad Berka, Center 2). The patients (n = 29) included in this study were referred for PET (Center 1, 21 patients) or PET/CT (Center 2, 8 patients) imaging with either a high suspicion of recurrent disease or for possible surgical or PSMA radioligand therapy planning. PET images of the whole body were performed at 1 hour p.i. and additional images of the pelvis at 2 hours p.i. In 23 of 29 patients, at least one focus of pathological tracer uptake suspicious for primary disease in the prostate lobe or recurrent disease was detected. Among healthy organs, the salivary glands, kidneys, and liver showed the highest radiotracer uptake. Lesions suspicious for PCa were detected with excellent contrast as early as 1 hour p.i. with high detection rates even at low prostate-specific antigen (PSA) levels. The preliminary results of this study demonstrate the high potential of 64 Cu-PSMA ligand PET/CT imaging in patients with recurrent disease and in the primary staging of selected patients with progressive local disease. The acquired PET images showed an excellent resolution of the detected lesions with very high lesion-to- background contrast. Furthermore, the long half-life of 64 Cu allows distribution of the tracer to clinical PET centers that lack radiochemistry facilities for the preparation of 68 Ga-PSMA ligand (satellite concept).

Combining image-processing and image compression schemes

NASA Technical Reports Server (NTRS)

Greenspan, H.; Lee, M.-C.

1995-01-01

An investigation into the combining of image-processing schemes, specifically an image enhancement scheme, with existing compression schemes is discussed. Results are presented on the pyramid coding scheme, the subband coding scheme, and progressive transmission. Encouraging results are demonstrated for the combination of image enhancement and pyramid image coding schemes, especially at low bit rates. Adding the enhancement scheme to progressive image transmission allows enhanced visual perception at low resolutions. In addition, further progressing of the transmitted images, such as edge detection schemes, can gain from the added image resolution via the enhancement.

Estimation of chromatic errors from broadband images for high contrast imaging: sensitivity analysis

NASA Astrophysics Data System (ADS)

Sirbu, Dan; Belikov, Ruslan

2016-01-01

Many concepts have been proposed to enable direct imaging of planets around nearby stars, and which would enable spectroscopic observations of their atmospheric observations and the potential discovery of biomarkers. The main technical challenge associated with direct imaging of exoplanets is to effectively control both the diffraction and scattered light from the star so that the dim planetary companion can be seen. Usage of an internal coronagraph with an adaptive optical system for wavefront correction is one of the most mature methods and is being developed as an instrument addition to the WFIRST-AFTA space mission. In addition, such instruments as GPI and SPHERE are already being used on the ground and are yielding spectra of giant planets. For the deformable mirror (DM) to recover a dark hole region with sufficiently high contrast in the image plane, mid-spatial frequency wavefront errors must be estimated. To date, most broadband lab demonstrations use narrowband filters to obtain an estimate of the the chromaticity of the wavefront error and this can result in usage of a large percentage of the total integration time. Previously, we have proposed a method to estimate the chromaticity of wavefront errors using only broadband images; we have demonstrated that under idealized conditions wavefront errors can be estimated from images composed of discrete wavelengths. This is achieved by using DM probes with sufficient spatially-localized chromatic diversity. Here we report on the results of a study of the performance of this method with respect to realistic broadband images including noise. Additionally, we study optimal probe patterns that enable reduction of the number of probes used and compare the integration time with narrowband and IFS estimation methods.

The relationship between three-dimensional imaging and group decision making: an exploratory study.

PubMed

Litynski, D M; Grabowski, M; Wallace, W A

1997-07-01

This paper describes an empirical investigation of the effect of three dimensional (3-D) imaging on group performance in a tactical planning task. The objective of the study is to examine the role that stereoscopic imaging can play in supporting face-to-face group problem solving and decision making-in particular, the alternative generation and evaluation processes in teams. It was hypothesized that with the stereoscopic display, group members would better visualize the information concerning the task environment, producing open communication and information exchanges. The experimental setting was a tactical command and control task, and the quality of the decisions and nature of the group decision process were investigated with three treatments: 1) noncomputerized, i.e., topographic maps with depth cues; 2) two-dimensional (2-D) imaging; and 3) stereoscopic imaging. The results were mixed on group performance. However, those groups with the stereoscopic displays generated more alternatives and spent less time on evaluation. In addition, the stereoscopic decision aid did not interfere with the group problem solving and decision-making processes. The paper concludes with a discussion of potential benefits, and the need to resolve demonstrated weaknesses of the technology.

Clinical evaluation of watermarked medical images.

PubMed

Zain, Jasni M; Fauzi, Abdul M; Aziz, Azian A

2006-01-01

Digital watermarking medical images provides security to the images. The purpose of this study was to see whether digitally watermarked images changed clinical diagnoses when assessed by radiologists. We embedded 256 bits watermark to various medical images in the region of non-interest (RONI) and 480K bits in both region of interest (ROI) and RONI. Our results showed that watermarking medical images did not alter clinical diagnoses. In addition, there was no difference in image quality when visually assessed by the medical radiologists. We therefore concluded that digital watermarking medical images were safe in terms of preserving image quality for clinical purposes.

Image correlation and sampling study

NASA Technical Reports Server (NTRS)

Popp, D. J.; Mccormack, D. S.; Sedwick, J. L.

1972-01-01

The development of analytical approaches for solving image correlation and image sampling of multispectral data is discussed. Relevant multispectral image statistics which are applicable to image correlation and sampling are identified. The general image statistics include intensity mean, variance, amplitude histogram, power spectral density function, and autocorrelation function. The translation problem associated with digital image registration and the analytical means for comparing commonly used correlation techniques are considered. General expressions for determining the reconstruction error for specific image sampling strategies are developed.

Axial nonimaging characteristics of imaging lenses: discussion.

PubMed

Siew, Ronian

2016-05-01

At observation planes away from the image plane, an imaging lens is a nonimaging optic. We examine the variation of axial irradiance with distance in image space and highlight the following little-known observation for discussion: On a per-unit-area basis, the position of the highest concentration in image space is generally not at the focal plane. This characteristic is contrary to common experience, and it offers an additional degree of freedom for the design of detection systems. Additionally, it would also apply to lenses with negative refractive index. The position of peak concentration and its irradiance is dependent upon the location and irradiance of the image. As such, this discussion also includes a close examination of expressions for image irradiance and explains how they are related to irradiance calculations beyond the image plane. This study is restricted to rotationally symmetric refractive imaging systems with incoherent extended Lambertian sources.

Image processing of angiograms: A pilot study

NASA Technical Reports Server (NTRS)

Larsen, L. E.; Evans, R. A.; Roehm, J. O., Jr.

1974-01-01

The technology transfer application this report describes is the result of a pilot study of image-processing methods applied to the image enhancement, coding, and analysis of arteriograms. Angiography is a subspecialty of radiology that employs the introduction of media with high X-ray absorption into arteries in order to study vessel pathology as well as to infer disease of the organs supplied by the vessel in question.

Preliminary study of the reliability of imaging charge coupled devices

NASA Technical Reports Server (NTRS)

Beall, J. R.; Borenstein, M. D.; Homan, R. A.; Johnson, D. L.; Wilson, D. D.; Young, V. F.

1978-01-01

Imaging CCDs are capable of low light level response and high signal-to-noise ratios. In space applications they offer the user the ability to achieve extremely high resolution imaging with minimum circuitry in the photo sensor array. This work relates the CCD121H Fairchild device to the fundamentals of CCDs and the representative technologies. Several failure modes are described, construction is analyzed and test results are reported. In addition, the relationship of the device reliability to packaging principles is analyzed and test data presented. Finally, a test program is defined for more general reliability evaluation of CCDs.

A comparison study of image features between FFDM and film mammogram images

PubMed Central

Jing, Hao; Yang, Yongyi; Wernick, Miles N.; Yarusso, Laura M.; Nishikawa, Robert M.

2012-01-01

Purpose: This work is to provide a direct, quantitative comparison of image features measured by film and full-field digital mammography (FFDM). The purpose is to investigate whether there is any systematic difference between film and FFDM in terms of quantitative image features and their influence on the performance of a computer-aided diagnosis (CAD) system. Methods: The authors make use of a set of matched film-FFDM image pairs acquired from cadaver breast specimens with simulated microcalcifications consisting of bone and teeth fragments using both a GE digital mammography system and a screen-film system. To quantify the image features, the authors consider a set of 12 textural features of lesion regions and six image features of individual microcalcifications (MCs). The authors first conduct a direct comparison on these quantitative features extracted from film and FFDM images. The authors then study the performance of a CAD classifier for discriminating between MCs and false positives (FPs) when the classifier is trained on images of different types (film, FFDM, or both). Results: For all the features considered, the quantitative results show a high degree of correlation between features extracted from film and FFDM, with the correlation coefficients ranging from 0.7326 to 0.9602 for the different features. Based on a Fisher sign rank test, there was no significant difference observed between the features extracted from film and those from FFDM. For both MC detection and discrimination of FPs from MCs, FFDM had a slight but statistically significant advantage in performance; however, when the classifiers were trained on different types of images (acquired with FFDM or SFM) for discriminating MCs from FPs, there was little difference. Conclusions: The results indicate good agreement between film and FFDM in quantitative image features. While FFDM images provide better detection performance in MCs, FFDM and film images may be interchangeable for the purposes of

Automated image segmentation-assisted flattening of atomic force microscopy images.

PubMed

Wang, Yuliang; Lu, Tongda; Li, Xiaolai; Wang, Huimin

2018-01-01

Atomic force microscopy (AFM) images normally exhibit various artifacts. As a result, image flattening is required prior to image analysis. To obtain optimized flattening results, foreground features are generally manually excluded using rectangular masks in image flattening, which is time consuming and inaccurate. In this study, a two-step scheme was proposed to achieve optimized image flattening in an automated manner. In the first step, the convex and concave features in the foreground were automatically segmented with accurate boundary detection. The extracted foreground features were taken as exclusion masks. In the second step, data points in the background were fitted as polynomial curves/surfaces, which were then subtracted from raw images to get the flattened images. Moreover, sliding-window-based polynomial fitting was proposed to process images with complex background trends. The working principle of the two-step image flattening scheme were presented, followed by the investigation of the influence of a sliding-window size and polynomial fitting direction on the flattened images. Additionally, the role of image flattening on the morphological characterization and segmentation of AFM images were verified with the proposed method.

Dynamic studies of small animals with a four-color diffuse optical tomography imager

NASA Astrophysics Data System (ADS)

Schmitz, Christoph H.; Graber, Harry L.; Pei, Yaling; Farber, Mark; Stewart, Mark; Levina, Rita D.; Levin, Mikhail B.; Xu, Yong; Barbour, Randall L.

2005-09-01

We present newly developed instrumentation for full-tomographic four-wavelength, continuous wave, diffuse optical tomography (DOT) imaging on small animals. A small-animal imaging stage was constructed, from materials compatible with in-magnet studies, which offers stereotaxic fixation of the animal and precise, stable probe positioning. Instrument performance, based on calibration and phantom studies, demonstrates excellent long-term signal stability. DOT measurements of the functional rat brain response to electric paw stimulation are presented, and these demonstrate high data quality and excellent sensitivity to hemodynamic changes. A general linear model analysis on individual trials is used to localize and quantify the occurrence of functional behavior associated with the different hemoglobin state responses. Statistical evaluation of outcomes of individual trials is employed to identify significant regional response variations for different stimulation sites. Image results reveal a diffuse cortical response and a strong reaction of the thalamus, both indicative of activation of pain pathways by the stimulation. In addition, a weaker lateralized functional component is observed in the brain response, suggesting presence of motor activation. An important outcome of the experiment is that it shows that reactions to individual provocations can be monitored, without having to resort to signal averaging. Thus the described technology may be useful for studies of long-term trends in hemodynamic response, as would occur, for example, in behavioral studies involving freely moving animals.

An Exploratory Study of Residents’ Perception of Place Image

PubMed Central

Stylidis, Dimitrios; Sit, Jason; Biran, Avital

2014-01-01

Studies on place image have predominantly focused on the tourists’ destination image and have given limited attention to other stakeholders’ perspectives. This study aims to address this gap by focusing on the notion of residents’ place image, whereby it reviews existing literature on residents’ place image in terms of whether common attributes can be identified, and examines the role of community-focused attributes in its measurement. Data collected from a sample of 481 Kavala residents (Greece) were subjected to exploratory and confirmatory factor analysis. The study reveals that the existing measurement tools have typically emphasized destination-focused attributes and neglected community-focused attributes. This study contributes to the residents’ place image research by proposing a more holistic measurement, which consisted of four dimensions: physical appearance, community services, social environment, and entertainment opportunities. The study also offers practical insights for developing and promoting a tourist place while simultaneously enhancing its residents’ quality of life. PMID:29708109

Evaluation of automatic image quality assessment in chest CT - A human cadaver study.

PubMed

Franck, Caro; De Crop, An; De Roo, Bieke; Smeets, Peter; Vergauwen, Merel; Dewaele, Tom; Van Borsel, Mathias; Achten, Eric; Van Hoof, Tom; Bacher, Klaus

2017-04-01

The evaluation of clinical image quality (IQ) is important to optimize CT protocols and to keep patient doses as low as reasonably achievable. Considering the significant amount of effort needed for human observer studies, automatic IQ tools are a promising alternative. The purpose of this study was to evaluate automatic IQ assessment in chest CT using Thiel embalmed cadavers. Chest CT's of Thiel embalmed cadavers were acquired at different exposures. Clinical IQ was determined by performing a visual grading analysis. Physical-technical IQ (noise, contrast-to-noise and contrast-detail) was assessed in a Catphan phantom. Soft and sharp reconstructions were made with filtered back projection and two strengths of iterative reconstruction. In addition to the classical IQ metrics, an automatic algorithm was used to calculate image quality scores (IQs). To be able to compare datasets reconstructed with different kernels, the IQs values were normalized. Good correlations were found between IQs and the measured physical-technical image quality: noise (ρ=-1.00), contrast-to-noise (ρ=1.00) and contrast-detail (ρ=0.96). The correlation coefficients between IQs and the observed clinical image quality of soft and sharp reconstructions were 0.88 and 0.93, respectively. The automatic scoring algorithm is a promising tool for the evaluation of thoracic CT scans in daily clinical practice. It allows monitoring of the image quality of a chest protocol over time, without human intervention. Different reconstruction kernels can be compared after normalization of the IQs. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

A Clinical Feasibility Study of Atrial and Ventricular Electromechanical Wave Imaging

PubMed Central

Provost, Jean; Gambhir, Alok; Vest, John; Garan, Hasan; Konofagou, Elisa E.

2014-01-01

Background Cardiac Resynchronization Therapy (CRT) and atrial ablation currently lack a noninvasive imaging modality for reliable treatment planning and monitoring. Electromechanical Wave Imaging (EWI) is an ultrasound-based method that has previously been shown to be capable of noninvasively and transmurally mapping the activation sequence of the heart in animal studies by estimating and imaging the electromechanical wave, i.e., the transient strains occurring in response to the electrical activation, at both very high temporal and spatial resolution. Objective Demonstrate the feasibility of noninvasive transthoracic EWI for mapping the activation sequence during different cardiac rhythms in humans. Methods EWI was performed in CRT patients with a left bundle-branch block (LBBB), during sinus rhythm, left-ventricular pacing, and right-ventricular pacing and in atrial flutter (AFL) patients before intervention and correlated with results from invasive intracardiac electrical mapping studies during intervention. Additionally, the feasibility of single-heartbeat EWI at 2000 frames/s, is demonstrated in humans for the first time in a subject with both AFL and right bundle-branch-block. Results The electromechanical activation maps demonstrated the capability of EWI to localize the pacing sites and characterize the LBBB activation sequence transmurally in CRT patients. In AFL patients, the propagation patterns obtained with EWI were in agreement with results obtained from invasive intracardiac mapping studies. Conclusion Our findings demonstrate the potential capability of EWI to aid in monitoring and follow-up of patients undergoing CRT pacing therapy and atrial ablation with preliminary validation in vivo. PMID:23454060

High throughput imaging cytometer with acoustic focussing† †Electronic supplementary information (ESI) available: High throughput imaging cytometer with acoustic focussing. See DOI: 10.1039/c5ra19497k Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file.

PubMed Central

Zmijan, Robert; Jonnalagadda, Umesh S.; Carugo, Dario; Kochi, Yu; Lemm, Elizabeth; Packham, Graham; Hill, Martyn

2015-01-01

We demonstrate an imaging flow cytometer that uses acoustic levitation to assemble cells and other particles into a sheet structure. This technique enables a high resolution, low noise CMOS camera to capture images of thousands of cells with each frame. While ultrasonic focussing has previously been demonstrated for 1D cytometry systems, extending the technology to a planar, much higher throughput format and integrating imaging is non-trivial, and represents a significant jump forward in capability, leading to diagnostic possibilities not achievable with current systems. A galvo mirror is used to track the images of the moving cells permitting exposure times of 10 ms at frame rates of 50 fps with motion blur of only a few pixels. At 80 fps, we demonstrate a throughput of 208 000 beads per second. We investigate the factors affecting motion blur and throughput, and demonstrate the system with fluorescent beads, leukaemia cells and a chondrocyte cell line. Cells require more time to reach the acoustic focus than beads, resulting in lower throughputs; however a longer device would remove this constraint. PMID:29456838

Optical Detection of Ultrasound in Photoacoustic Imaging

PubMed Central

Dong, Biqin; Sun, Cheng; Zhang, Hao F.

2017-01-01

Objective Photoacoustic (PA) imaging emerges as a unique tool to study biological samples based on optical absorption contrast. In PA imaging, piezoelectric transducers are commonly used to detect laser-induced ultrasonic waves. However, they typically lack adequate broadband sensitivity at ultrasonic frequency higher than 100 MHz while their bulky size and optically opaque nature cause technical difficulties in integrating PA imaging with conventional optical imaging modalities. To overcome these limitations, optical methods of ultrasound detection were developed and shown their unique applications in photoacoustic imaging. Methods We provide an overview of recent technological advances in optical methods of ultrasound detection and their applications in PA imaging. A general theoretical framework describing sensitivity, bandwidth, and angular responses of optical ultrasound detection is also introduced. Results Optical methods of ultrasound detection can provide improved detection angle and sensitivity over significantly extended bandwidth. In addition, its versatile variants also offer additional advantages, such as device miniaturization, optical transparency, mechanical flexibility, minimal electrical/mechanical crosstalk, and potential noncontact PA imaging. Conclusion The optical ultrasound detection methods discussed in this review and their future evolution may play an important role in photoacoustic imaging for biomedical study and clinical diagnosis. PMID:27608445

Radiotracer imaging studies in hepatic encephalopathy: ISHEN practice guidelines.

PubMed

Berding, Georg; Banati, Richard B; Buchert, Ralph; Chierichetti, Franca; Grover, Vijay P B; Kato, Akinobu; Keiding, Susanne; Taylor-Robinson, Simon D

2009-05-01

There is lack of consensus on radiotracer usage in hepatic encephalopathy (HE). We have focused our attention on three main areas: (i) radiotracer imaging in animal models of HE, (ii) methodological issues of radiotracer imaging in HE and (iii) radiotracer imaging studies on the pathophysiology and (new) therapies in HE. We suggest the following: 1. Positron emission tomography (PET) and single photon emission computed tomography lend themselves to the study of animal models of HE, but the models that are suitable depend on the specific research question. Magnetic resonance imaging (MRI) may be a useful alternative technique. 2. Owing to the cost of the technique, there is a need for multicentre human PET studies to overcome the problem of underpowered small studies being undertaken in individual research centres. There should be a unified PET protocol with central, anonymised data analysis in one centre, using validated methodology, on behalf of all participating centres. Such studies would be useful for the assessment of early intervention in patients with subtle neuropsychiatric symptoms, or for clarification of the effect of liver transplantation on HE. 3. While radiotracer imaging modalities remain useful research tools for the study of pathogenesis and for the assessment of treatment effects, there is no consensus on the use of imaging in routine clinical practice for diagnosis and prognosis. The most promising objective tools appear to be magnetic resonance spectroscopy (MRS) and volumetric MRI, which can be performed in multiple centres without the difficulties that radiotracer imaging entail.

Application of multispectral imaging in quantitative immunohistochemistry study of breast cancer: a comparative study.

PubMed

Liu, Wen-Lou; Wang, Lin-Wei; Chen, Jia-Mei; Yuan, Jing-Ping; Xiang, Qing-Ming; Yang, Gui-Fang; Qu, Ai-Ping; Liu, Juan; Li, Yan

2016-04-01

Multispectral imaging (MSI) based on imaging and spectroscopy, as relatively novel to the field of histopathology, has been used in biomedical multidisciplinary researches. We analyzed and compared the utility of multispectral (MS) versus conventional red-green-blue (RGB) images for immunohistochemistry (IHC) staining to explore the advantages of MSI in clinical-pathological diagnosis. The MS images acquired of IHC-stained membranous marker human epidermal growth factor receptor 2 (HER2), cytoplasmic marker cytokeratin5/6 (CK5/6), and nuclear marker estrogen receptor (ER) have higher resolution, stronger contrast, and more accurate segmentation than the RGB images. The total signal optical density (OD) values for each biomarker were higher in MS images than in RGB images (all P < 0.05). Moreover, receiver operator characteristic (ROC) analysis revealed that a greater area under the curve (AUC), higher sensitivity, and specificity in evaluation of HER2 gene were achieved by MS images (AUC = 0.91, 89.1 %, 83.2 %) than RGB images (AUC = 0.87, 84.5, and 81.8 %). There was no significant difference between quantitative results of RGB images and clinico-pathological characteristics (P > 0.05). However, by quantifying MS images, the total signal OD values of HER2 positive expression were correlated with lymph node status and histological grades (P = 0.02 and 0.04). Additionally, the consistency test results indicated the inter-observer agreement was more robust in MS images for HER2 (inter-class correlation coefficient (ICC) = 0.95, r s = 0.94), CK5/6 (ICC = 0.90, r s = 0.88), and ER (ICC = 0.94, r s = 0.94) (all P < 0.001) than that in RGB images for HER2 (ICC = 0.91, r s = 0.89), CK5/6 (ICC = 0.85, r s = 0.84), and ER (ICC = 0.90, r s = 0.89) (all P < 0.001). Our results suggest that the application of MS images in quantitative IHC analysis could obtain higher accuracy, reliability, and more

Improving image reconstruction of bioluminescence imaging using a priori information from ultrasound imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Jayet, Baptiste; Ahmad, Junaid; Taylor, Shelley L.; Hill, Philip J.; Dehghani, Hamid; Morgan, Stephen P.

2017-03-01

Bioluminescence imaging (BLI) is a commonly used imaging modality in biology to study cancer in vivo in small animals. Images are generated using a camera to map the optical fluence emerging from the studied animal, then a numerical reconstruction algorithm is used to locate the sources and estimate their sizes. However, due to the strong light scattering properties of biological tissues, the resolution is very limited (around a few millimetres). Therefore obtaining accurate information about the pathology is complicated. We propose a combined ultrasound/optics approach to improve accuracy of these techniques. In addition to the BLI data, an ultrasound probe driven by a scanner is used for two main objectives. First, to obtain a pure acoustic image, which provides structural information of the sample. And second, to alter the light emission by the bioluminescent sources embedded inside the sample, which is monitored using a high speed optical detector (e.g. photomultiplier tube). We will show that this last measurement, used in conjunction with the ultrasound data, can provide accurate localisation of the bioluminescent sources. This can be used as a priori information by the numerical reconstruction algorithm, greatly increasing the accuracy of the BLI image reconstruction as compared to the image generated using only BLI data.

Reformatted images improve the detection rate of acute traumatic subdural hematomas on brain CT compared with axial images alone.

PubMed

Amrhein, Timothy J; Mostertz, William; Matheus, Maria Gisele; Maass-Bolles, Genevieve; Sharma, Komal; Collins, Heather R; Kranz, Peter G

2017-02-01

Subdural hematomas (SDHs) comprise a significant percentage of missed intracranial hemorrhage on axial brain CT. SDH detection rates could be improved with the addition of reformatted images. Though performed at some centers, the potential additional diagnostic sensitivity of reformatted images has not yet been investigated. The purpose of our study is to determine if the addition of coronal and sagittal reformatted images to an axial brain CT increases the sensitivity and specificity for detection of acute traumatic SDH. We retrospectively reviewed consecutive brain CTs acquired for acute trauma that contained new SDHs. An equivalent number of normal brain CTs served as control. Paired sets of images were created for each case: (1) axial images only ("axial only") and (2) axial, coronal, sagittal images ("reformat added"). Three readers interpreted both the axial only and companion reformat added for each case, separated by 1 month. Reading times and SDH detection rates were compared. One hundred SDH and 100 negative examinations were collected. Sensitivity and specificity for the axial-only scans were 75.7 and 94.3 %, respectively, compared with 88.3 and 98.3 % for reformat added. There was a 24.3 % false negative (missed SDH) rate with axial-only scans versus 11.7 % with reformat added (p = <0.001). Median reader interpretation times were longer with the addition of reformatted images (125 versus 89 s), but this difference was not significant (p = 0.23). The addition of coronal and sagittal images in trauma brain CT resulted in improved sensitivity and specificity as well as a reduction in SDH false negatives by greater than 50 %. Reformatted images substantially reduce the number of missed SDHs compared with axial images alone.

A reference dataset for deformable image registration spatial accuracy evaluation using the COPDgene study archive

NASA Astrophysics Data System (ADS)

Castillo, Richard; Castillo, Edward; Fuentes, David; Ahmad, Moiz; Wood, Abbie M.; Ludwig, Michelle S.; Guerrero, Thomas

2013-05-01

Landmark point-pairs provide a strategy to assess deformable image registration (DIR) accuracy in terms of the spatial registration of the underlying anatomy depicted in medical images. In this study, we propose to augment a publicly available database (www.dir-lab.com) of medical images with large sets of manually identified anatomic feature pairs between breath-hold computed tomography (BH-CT) images for DIR spatial accuracy evaluation. Ten BH-CT image pairs were randomly selected from the COPDgene study cases. Each patient had received CT imaging of the entire thorax in the supine position at one-fourth dose normal expiration and maximum effort full dose inspiration. Using dedicated in-house software, an imaging expert manually identified large sets of anatomic feature pairs between images. Estimates of inter- and intra-observer spatial variation in feature localization were determined by repeat measurements of multiple observers over subsets of randomly selected features. 7298 anatomic landmark features were manually paired between the 10 sets of images. Quantity of feature pairs per case ranged from 447 to 1172. Average 3D Euclidean landmark displacements varied substantially among cases, ranging from 12.29 (SD: 6.39) to 30.90 (SD: 14.05) mm. Repeat registration of uniformly sampled subsets of 150 landmarks for each case yielded estimates of observer localization error, which ranged in average from 0.58 (SD: 0.87) to 1.06 (SD: 2.38) mm for each case. The additions to the online web database (www.dir-lab.com) described in this work will broaden the applicability of the reference data, providing a freely available common dataset for targeted critical evaluation of DIR spatial accuracy performance in multiple clinical settings. Estimates of observer variance in feature localization suggest consistent spatial accuracy for all observers across both four-dimensional CT and COPDgene patient cohorts.

In situ X-ray imaging of defect and molten pool dynamics in laser additive manufacturing.

PubMed

Leung, Chu Lun Alex; Marussi, Sebastian; Atwood, Robert C; Towrie, Michael; Withers, Philip J; Lee, Peter D

2018-04-10

The laser-matter interaction and solidification phenomena associated with laser additive manufacturing (LAM) remain unclear, slowing its process development and optimisation. Here, through in situ and operando high-speed synchrotron X-ray imaging, we reveal the underlying physical phenomena during the deposition of the first and second layer melt tracks. We show that the laser-induced gas/vapour jet promotes the formation of melt tracks and denuded zones via spattering (at a velocity of 1 m s -1 ). We also uncover mechanisms of pore migration by Marangoni-driven flow (recirculating at a velocity of 0.4 m s -1 ), pore dissolution and dispersion by laser re-melting. We develop a mechanism map for predicting the evolution of melt features, changes in melt track morphology from a continuous hemi-cylindrical track to disconnected beads with decreasing linear energy density and improved molten pool wetting with increasing laser power. Our results clarify aspects of the physics behind LAM, which are critical for its development.

X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong

2015-07-15

Several X-ray techniques for studying structure, elastic properties, viscosity, and immiscibility of liquids at high pressures have been integrated using a Paris-Edinburgh press at the 16-BM-B beamline of the Advanced Photon Source. Here, we report the development of X-ray imaging techniques suitable for studying behavior of liquids at high pressures and high temperatures. White X-ray radiography allows for imaging phase separation and immiscibility of melts at high pressures, identified not only by density contrast but also by phase contrast imaging in particular for low density contrast liquids such as silicate and carbonate melts. In addition, ultrafast X-ray imaging, at framemore » rates up to ∼10{sup 5} frames/second (fps) in air and up to ∼10{sup 4} fps in Paris-Edinburgh press, enables us to investigate dynamics of liquids at high pressures. Very low viscosities of melts similar to that of water can be reliably measured. These high-pressure X-ray imaging techniques provide useful tools for understanding behavior of liquids or melts at high pressures and high temperatures.« less

X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press.

PubMed

Kono, Yoshio; Kenney-Benson, Curtis; Shibazaki, Yuki; Park, Changyong; Wang, Yanbin; Shen, Guoyin

2015-07-01

Several X-ray techniques for studying structure, elastic properties, viscosity, and immiscibility of liquids at high pressures have been integrated using a Paris-Edinburgh press at the 16-BM-B beamline of the Advanced Photon Source. Here, we report the development of X-ray imaging techniques suitable for studying behavior of liquids at high pressures and high temperatures. White X-ray radiography allows for imaging phase separation and immiscibility of melts at high pressures, identified not only by density contrast but also by phase contrast imaging in particular for low density contrast liquids such as silicate and carbonate melts. In addition, ultrafast X-ray imaging, at frame rates up to ∼10(5) frames/second (fps) in air and up to ∼10(4) fps in Paris-Edinburgh press, enables us to investigate dynamics of liquids at high pressures. Very low viscosities of melts similar to that of water can be reliably measured. These high-pressure X-ray imaging techniques provide useful tools for understanding behavior of liquids or melts at high pressures and high temperatures.

Dual-modality imaging

NASA Astrophysics Data System (ADS)

Hasegawa, Bruce; Tang, H. Roger; Da Silva, Angela J.; Wong, Kenneth H.; Iwata, Koji; Wu, Max C.

2001-09-01

In comparison to conventional medical imaging techniques, dual-modality imaging offers the advantage of correlating anatomical information from X-ray computed tomography (CT) with functional measurements from single-photon emission computed tomography (SPECT) or with positron emission tomography (PET). The combined X-ray/radionuclide images from dual-modality imaging can help the clinician to differentiate disease from normal uptake of radiopharmaceuticals, and to improve diagnosis and staging of disease. In addition, phantom and animal studies have demonstrated that a priori structural information from CT can be used to improve quantification of tissue uptake and organ function by correcting the radionuclide data for errors due to photon attenuation, partial volume effects, scatter radiation, and other physical effects. Dual-modality imaging therefore is emerging as a method of improving the visual quality and the quantitative accuracy of radionuclide imaging for diagnosis of patients with cancer and heart disease.

Pulse splitter-based nonlinear microscopy for live-cardiomyocyte imaging

PubMed Central

Wang, Zhonghai; Qin, Wan; Shao, Yonghong; Ma, Siyu; Borg, Thomas K.; Gao, Bruce Z.

2015-01-01

Second harmonic generation (SHG) microscopy is a new imaging technique used in sarcomeric-addition studies. However, during the early stage of cell culture in which sarcomeric additions occur, the neonatal cardiomyocytes that we have been working with are very sensitive to photodamage, the resulting high rate of cell death prevents systematic study of sarcomeric addition using a conventional SHG system. To address this challenge, we introduced use of the pulse-splitter system developed by Na Ji et al. in our two photon excitation fluorescence (TPEF) and SHG hybrid microscope. The system dramatically reduced photodamage to neonatal cardiomyocytes in early stages of culture, greatly increasing cell viability. Thus continuous imaging of live cardiomyocytes was achieved with a stronger laser and for a longer period than has been reported in the literature. The pulse splitter-based TPEF-SHG microscope constructed in this study was demonstrated to be an ideal imaging system for sarcomeric addition-related investigations of neonatal cardiomyocytes in early stages of culture. PMID:25767692

Study of fish response using particle image velocimetry and high-speed, high-resolution imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Z.; Richmond, M. C.; Mueller, R. P.

2004-10-01

Fish swimming has fascinated both engineers and fish biologists for decades. Digital particle image velocimetry (DPIV) and high-speed, high-resolution digital imaging are recently developed analysis tools that can help engineers and biologists better understand how fish respond to turbulent environments. This report details studies to evaluate DPIV. The studies included a review of existing literature on DPIV, preliminary studies to test the feasibility of using DPIV conducted at our Flow Biology Laboratory in Richland, Washington September through December 2003, and applications of high-speed, high-resolution digital imaging with advanced motion analysis to investigations of fish injury mechanisms in turbulent shear flowsmore » and bead trajectories in laboratory physical models. Several conclusions were drawn based on these studies, which are summarized as recommendations for proposed research at the end of this report.« less

Kinetic studies of retinol addition radicals.

PubMed

El-Agamey, Ali; Fukuzumi, Shunichi; Naqvi, K Razi; McGarvey, David J

2011-03-07

Retinol neutral radicals (RS-retinol˙), generated from the reaction of retinol with 4-pyridylthiyl and 2-pyridylthiyl radicals in argon-saturated methanol, undergo β-elimination, which can be monitored via the slow secondary absorption rise at 380 nm attributed to the rearrangement of the unstable retinol neutral addition radicals to the more stable addition radicals. Rate constants for the β-elimination reactions (k(β)) of 4-PyrS-retinol˙ were measured at different temperatures and the Arrhenius equation for the reaction is described by log (k(β)/s(-1)) = (12.7 ± 0.2) - (54.3 ± 1.3)/θ, where θ = 2.3RT kJ mol(-1). The reactivities of retinol addition radicals (RS-retinol˙), generated from the reaction of retinol with various thiyl radicals, towards oxygen have also been investigated in methanol. In the presence of oxygen, the decay of RS-retinol˙ fits to biexponential kinetics and both observed rate constants for the RS-retinol˙ decay are oxygen-concentration dependent. This suggests that at least two thiyl addition radicals, formed from the reaction of RS˙ with retinol, undergo oxygen addition reactions. In light of the estimated rate constants for oxygen addition to RS-retinol˙ and RS-CAR˙ (CAR: carotenoid), the antioxidant-prooxidant properties of retinol are discussed.

Influence of study design on digital pathology image quality evaluation: the need to define a clinical task

PubMed Central

Platiša, Ljiljana; Brantegem, Leen Van; Kumcu, Asli; Ducatelle, Richard; Philips, Wilfried

2017-01-01

Abstract. Despite the current rapid advance in technologies for whole slide imaging, there is still no scientific consensus on the recommended methodology for image quality assessment of digital pathology slides. For medical images in general, it has been recommended to assess image quality in terms of doctors’ success rates in performing a specific clinical task while using the images (clinical image quality, cIQ). However, digital pathology is a new modality, and already identifying the appropriate task is difficult. In an alternative common approach, humans are asked to do a simpler task such as rating overall image quality (perceived image quality, pIQ), but that involves the risk of nonclinically relevant findings due to an unknown relationship between the pIQ and cIQ. In this study, we explored three different experimental protocols: (1) conducting a clinical task (detecting inclusion bodies), (2) rating image similarity and preference, and (3) rating the overall image quality. Additionally, within protocol 1, overall quality ratings were also collected (task-aware pIQ). The experiments were done by diagnostic veterinary pathologists in the context of evaluating the quality of hematoxylin and eosin-stained digital pathology slides of animal tissue samples under several common image alterations: additive noise, blurring, change in gamma, change in color saturation, and JPG compression. While the size of our experiments was small and prevents drawing strong conclusions, the results suggest the need to define a clinical task. Importantly, the pIQ data collected under protocols 2 and 3 did not always rank the image alterations the same as their cIQ from protocol 1, warning against using conventional pIQ to predict cIQ. At the same time, there was a correlation between the cIQ and task-aware pIQ ratings from protocol 1, suggesting that the clinical experiment context (set by specifying the clinical task) may affect human visual attention and bring focus to

Influence of study design on digital pathology image quality evaluation: the need to define a clinical task.

PubMed

Platiša, Ljiljana; Brantegem, Leen Van; Kumcu, Asli; Ducatelle, Richard; Philips, Wilfried

2017-04-01

Despite the current rapid advance in technologies for whole slide imaging, there is still no scientific consensus on the recommended methodology for image quality assessment of digital pathology slides. For medical images in general, it has been recommended to assess image quality in terms of doctors' success rates in performing a specific clinical task while using the images (clinical image quality, cIQ). However, digital pathology is a new modality, and already identifying the appropriate task is difficult. In an alternative common approach, humans are asked to do a simpler task such as rating overall image quality (perceived image quality, pIQ), but that involves the risk of nonclinically relevant findings due to an unknown relationship between the pIQ and cIQ. In this study, we explored three different experimental protocols: (1) conducting a clinical task (detecting inclusion bodies), (2) rating image similarity and preference, and (3) rating the overall image quality. Additionally, within protocol 1, overall quality ratings were also collected (task-aware pIQ). The experiments were done by diagnostic veterinary pathologists in the context of evaluating the quality of hematoxylin and eosin-stained digital pathology slides of animal tissue samples under several common image alterations: additive noise, blurring, change in gamma, change in color saturation, and JPG compression. While the size of our experiments was small and prevents drawing strong conclusions, the results suggest the need to define a clinical task. Importantly, the pIQ data collected under protocols 2 and 3 did not always rank the image alterations the same as their cIQ from protocol 1, warning against using conventional pIQ to predict cIQ. At the same time, there was a correlation between the cIQ and task-aware pIQ ratings from protocol 1, suggesting that the clinical experiment context (set by specifying the clinical task) may affect human visual attention and bring focus to their criteria

A Relationship Between Visual Complexity and Aesthetic Appraisal of Car Front Images: An Eye-Tracker Study.

PubMed

Chassy, Philippe; Lindell, Trym A E; Jones, Jessica A; Paramei, Galina V

2015-01-01

Image aesthetic pleasure (AP) is conjectured to be related to image visual complexity (VC). The aim of the present study was to investigate whether (a) two image attributes, AP and VC, are reflected in eye-movement parameters; and (b) subjective measures of AP and VC are related. Participants (N=26) explored car front images (M=50) while their eye movements were recorded. Following image exposure (10 seconds), its VC and AP were rated. Fixation count was found to positively correlate with the subjective VC and its objective proxy, JPEG compression size, suggesting that this eye-movement parameter can be considered an objective behavioral measure of VC. AP, in comparison, positively correlated with average dwelling time. Subjective measures of AP and VC were related too, following an inverted U-shape function best-fit by a quadratic equation. In addition, AP was found to be modulated by car prestige. Our findings reveal a close relationship between subjective and objective measures of complexity and aesthetic appraisal, which is interpreted within a prototype-based theory framework. © The Author(s) 2015.

Attractive celebrity and peer images on Instagram: Effect on women's mood and body image.

PubMed

Brown, Zoe; Tiggemann, Marika

2016-12-01

A large body of research has documented that exposure to images of thin fashion models contributes to women's body dissatisfaction. The present study aimed to experimentally investigate the impact of attractive celebrity and peer images on women's body image. Participants were 138 female undergraduate students who were randomly assigned to view either a set of celebrity images, a set of equally attractive unknown peer images, or a control set of travel images. All images were sourced from public Instagram profiles. Results showed that exposure to celebrity and peer images increased negative mood and body dissatisfaction relative to travel images, with no significant difference between celebrity and peer images. This effect was mediated by state appearance comparison. In addition, celebrity worship moderated an increased effect of celebrity images on body dissatisfaction. It was concluded that exposure to attractive celebrity and peer images can be detrimental to women's body image. Copyright © 2016 Elsevier Ltd. All rights reserved.

Noninvasive imaging of experimental lung fibrosis.

PubMed

Zhou, Yong; Chen, Huaping; Ambalavanan, Namasivayam; Liu, Gang; Antony, Veena B; Ding, Qiang; Nath, Hrudaya; Eary, Janet F; Thannickal, Victor J

2015-07-01

Small animal models of lung fibrosis are essential for unraveling the molecular mechanisms underlying human fibrotic lung diseases; additionally, they are useful for preclinical testing of candidate antifibrotic agents. The current end-point measures of experimental lung fibrosis involve labor-intensive histological and biochemical analyses. These measures fail to account for dynamic changes in the disease process in individual animals and are limited by the need for large numbers of animals for longitudinal studies. The emergence of noninvasive imaging technologies provides exciting opportunities to image lung fibrosis in live animals as often as needed and to longitudinally track the efficacy of novel antifibrotic compounds. Data obtained by noninvasive imaging provide complementary information to histological and biochemical measurements. In addition, the use of noninvasive imaging in animal studies reduces animal usage, thus satisfying animal welfare concerns. In this article, we review these new imaging modalities with the potential for evaluation of lung fibrosis in small animal models. Such techniques include micro-computed tomography (micro-CT), magnetic resonance imaging, positron emission tomography (PET), single photon emission computed tomography (SPECT), and multimodal imaging systems including PET/CT and SPECT/CT. It is anticipated that noninvasive imaging will be increasingly used in animal models of fibrosis to gain insights into disease pathogenesis and as preclinical tools to assess drug efficacy.

A study for watermark methods appropriate to medical images.

PubMed

Cho, Y; Ahn, B; Kim, J S; Kim, I Y; Kim, S I

2001-06-01

The network system, including the picture archiving and communication system (PACS), is essential in hospital and medical imaging fields these days. Many medical images are accessed and processed on the web, as well as in PACS. Therefore, any possible accidents caused by the illegal modification of medical images must be prevented. Digital image watermark techniques have been proposed as a method to protect against illegal copying or modification of copyrighted material. Invisible signatures made by a digital image watermarking technique can be a solution to these problems. However, medical images have some different characteristics from normal digital images in that one must not corrupt the information contained in the original medical images. In this study, we suggest modified watermark methods appropriate for medical image processing and communication system that prevent clinically important data contained in original images from being corrupted.

Evaluation of multimodality imaging using image fusion with ultrasound tissue elasticity imaging in an experimental animal model.

PubMed

Paprottka, P M; Zengel, P; Cyran, C C; Ingrisch, M; Nikolaou, K; Reiser, M F; Clevert, D A

2014-01-01

secure differentiation between different tumor tissue areas in comparison to image fusion with MRI in our small study group. Therefore ultrasound tissue elasticity imaging might be used for fast detection of tumor response in the future whereas conventional grey scale imaging alone could not provide the additional information. By using standard, contrast-enhanced MRI images for reliable and reproducible slice positioning, the strongly user-dependent limitation of ultrasound tissue elasticity imaging may be overcome, especially for a comparison between baseline and follow-up measurements.

International students' image of rural Pennsylvania as a travel destination

Treesearch

Po-Ju Chen; Deborah L. Kerstetter

1998-01-01

The purpose of this study was to examine the image international students at Penn State have of rural travel destinations in the state of Pennsylvania. In addition, this study investigated whether destination image differed depending upon travel behavior and socio-demographic variables. Four distinct image dimensions, "tourism infrastructure," "...

Use of High Resolution 3D Diffusion Tensor Imaging to Study Brain White Matter Development in Live Neonatal Rats

PubMed Central

Cai, Yu; McMurray, Matthew S.; Oguz, Ipek; Yuan, Hong; Styner, Martin A.; Lin, Weili; Johns, Josephine M.; An, Hongyu

2011-01-01

High resolution diffusion tensor imaging (DTI) can provide important information on brain development, yet it is challenging in live neonatal rats due to the small size of neonatal brain and motion-sensitive nature of DTI. Imaging in live neonatal rats has clear advantages over fixed brain scans, as longitudinal and functional studies would be feasible to understand neuro-developmental abnormalities. In this study, we developed imaging strategies that can be used to obtain high resolution 3D DTI images in live neonatal rats at postnatal day 5 (PND5) and PND14, using only 3 h of imaging acquisition time. An optimized 3D DTI pulse sequence and appropriate animal setup to minimize physiological motion artifacts are the keys to successful high resolution 3D DTI imaging. Thus, a 3D rapid acquisition relaxation enhancement DTI sequence with twin navigator echoes was implemented to accelerate imaging acquisition time and minimize motion artifacts. It has been suggested that neonatal mammals possess a unique ability to tolerate mild-to-moderate hypothermia and hypoxia without long term impact. Thus, we additionally utilized this ability to minimize motion artifacts in magnetic resonance images by carefully suppressing the respiratory rate to around 15/min for PND5 and 30/min for PND14 using mild-to-moderate hypothermia. These imaging strategies have been successfully implemented to study how the effect of cocaine exposure in dams might affect brain development in their rat pups. Image quality resulting from this in vivo DTI study was comparable to ex vivo scans. fractional anisotropy values were also similar between the live and fixed brain scans. The capability of acquiring high quality in vivo DTI imaging offers a valuable opportunity to study many neurological disorders in brain development in an authentic living environment. PMID:22013426

Additional diagnostic value of multiplane echocardiography over biplane imaging in assessment of mitral prosthetic valves.

PubMed Central

Faletra, F.; De Chiara, F.; Corno, R.; Passini, L.

1996-01-01

OBJECTIVE: To evaluate how often multiplane transoesophageal echocardiography yields new or complementary data in mitral prostheses in comparison with the exclusive use of biplane imaging. PATIENTS: 73 consecutive patients with mitral prostheses who underwent multiplane transoesophageal echocardiograpy between January 1993 and December 1994. METHODS: Biplane images (transverse and longitudinal planes) and multiplane images (transverse, longitudinal, and intermediate planes) were recorded on two separate videotapes. The data provided by multiplane transoesophageal echocardiography were evaluated as (a) new data (abnormalities missed by biplane imaging); (b) complementary data (better delineating lesions already visualised by biplane imaging); or (c) redundant data (data already provided by biplane imaging). RESULTS: Multiplane transoesophageal echocardiography revealed new abnormalities in seven patients (9.5%) (thrombi in three and paraprosthetic leaks in the remaining four) and complementary data in nine (12.3%). In patients with paraprosthetic regurgitation, the possibility of continuously visualising the sewing ring by means of sequential angulations allowed the circumferential extension of the leak to be measured. In seven patients with paravalvar regurgitation who underwent surgery, the extension of the leak as measured by the multiplane approach closely corresponded with the surgical data. CONCLUSIONS: In comparison with the exclusive use of biplane imaging, the multiplane approach added new or complementary data in a significant proportion of patients with mitral prostheses. The ability to obtain the sequential adjacent planes allowed a more reliable appraisal of the extension of the leak and other abnormalities. Images PMID:8697166

Additive Manufacturing Infrared Inspection

NASA Technical Reports Server (NTRS)

Gaddy, Darrell

2014-01-01

Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

Additive manufacturing technology in reconstructive surgery.

PubMed

Fuller, Scott C; Moore, Michael G

2016-10-01

Technological advances have been part and parcel of modern reconstructive surgery, in that practitioners of this discipline are continually looking for innovative ways to perfect their craft and improve patient outcomes. We are currently in a technological climate wherein advances in computers, imaging, and science have coalesced with resulting innovative breakthroughs that are not merely limited to improved outcomes and enhanced patient care, but may provide novel approaches to training the next generation of reconstructive surgeons. New developments in software and modeling platforms, imaging modalities, tissue engineering, additive manufacturing, and customization of implants are poised to revolutionize the field of reconstructive surgery. The interface between technological advances and reconstructive surgery continues to expand. Additive manufacturing techniques continue to evolve in an effort to improve patient outcomes, decrease operative time, and serve as instructional tools for the training of reconstructive surgeons.

NMR relaxometry study of plaster mortar with polymer additives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jumate, E.; Manea, D.; Moldovan, D.

2013-11-13

The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T{sub 2} relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T{sub 2} distributions. These can bemore » associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T{sub 2} relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T{sub 2} relaxation rates corresponding to the bound water.« less

NMR relaxometry study of plaster mortar with polymer additives

NASA Astrophysics Data System (ADS)

Jumate, E.; Moldovan, D.; Fechete, R.; Manea, D.

2013-11-01

The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T2 relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T2 distributions. These can be associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T2 relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T2 relaxation rates corresponding to the bound water.

A comparison of 3D poly(ε-caprolactone) tissue engineering scaffolds produced with conventional and additive manufacturing techniques by means of quantitative analysis of SR μ-CT images

NASA Astrophysics Data System (ADS)

Brun, F.; Intranuovo, F.; Mohammadi, S.; Domingos, M.; Favia, P.; Tromba, G.

2013-07-01

The technique used to produce a 3D tissue engineering (TE) scaffold is of fundamental importance in order to guarantee its proper morphological characteristics. An accurate assessment of the resulting structural properties is therefore crucial in order to evaluate the effectiveness of the produced scaffold. Synchrotron radiation (SR) computed microtomography (μ-CT) combined with further image analysis seems to be one of the most effective techniques to this aim. However, a quantitative assessment of the morphological parameters directly from the reconstructed images is a non trivial task. This study considers two different poly(ε-caprolactone) (PCL) scaffolds fabricated with a conventional technique (Solvent Casting Particulate Leaching, SCPL) and an additive manufacturing (AM) technique (BioCell Printing), respectively. With the first technique it is possible to produce scaffolds with random, non-regular, rounded pore geometry. The AM technique instead is able to produce scaffolds with square-shaped interconnected pores of regular dimension. Therefore, the final morphology of the AM scaffolds can be predicted and the resulting model can be used for the validation of the applied imaging and image analysis protocols. It is here reported a SR μ-CT image analysis approach that is able to effectively and accurately reveal the differences in the pore- and throat-size distributions as well as connectivity of both AM and SCPL scaffolds.

MISTICA: Minimum Spanning Tree-based Coarse Image Alignment for Microscopy Image Sequences

PubMed Central

Ray, Nilanjan; McArdle, Sara; Ley, Klaus; Acton, Scott T.

2016-01-01

Registration of an in vivo microscopy image sequence is necessary in many significant studies, including studies of atherosclerosis in large arteries and the heart. Significant cardiac and respiratory motion of the living subject, occasional spells of focal plane changes, drift in the field of view, and long image sequences are the principal roadblocks. The first step in such a registration process is the removal of translational and rotational motion. Next, a deformable registration can be performed. The focus of our study here is to remove the translation and/or rigid body motion that we refer to here as coarse alignment. The existing techniques for coarse alignment are unable to accommodate long sequences often consisting of periods of poor quality images (as quantified by a suitable perceptual measure). Many existing methods require the user to select an anchor image to which other images are registered. We propose a novel method for coarse image sequence alignment based on minimum weighted spanning trees (MISTICA) that overcomes these difficulties. The principal idea behind MISTICA is to re-order the images in shorter sequences, to demote nonconforming or poor quality images in the registration process, and to mitigate the error propagation. The anchor image is selected automatically making MISTICA completely automated. MISTICA is computationally efficient. It has a single tuning parameter that determines graph width, which can also be eliminated by way of additional computation. MISTICA outperforms existing alignment methods when applied to microscopy image sequences of mouse arteries. PMID:26415193

MISTICA: Minimum Spanning Tree-Based Coarse Image Alignment for Microscopy Image Sequences.

PubMed

Ray, Nilanjan; McArdle, Sara; Ley, Klaus; Acton, Scott T

2016-11-01

Registration of an in vivo microscopy image sequence is necessary in many significant studies, including studies of atherosclerosis in large arteries and the heart. Significant cardiac and respiratory motion of the living subject, occasional spells of focal plane changes, drift in the field of view, and long image sequences are the principal roadblocks. The first step in such a registration process is the removal of translational and rotational motion. Next, a deformable registration can be performed. The focus of our study here is to remove the translation and/or rigid body motion that we refer to here as coarse alignment. The existing techniques for coarse alignment are unable to accommodate long sequences often consisting of periods of poor quality images (as quantified by a suitable perceptual measure). Many existing methods require the user to select an anchor image to which other images are registered. We propose a novel method for coarse image sequence alignment based on minimum weighted spanning trees (MISTICA) that overcomes these difficulties. The principal idea behind MISTICA is to reorder the images in shorter sequences, to demote nonconforming or poor quality images in the registration process, and to mitigate the error propagation. The anchor image is selected automatically making MISTICA completely automated. MISTICA is computationally efficient. It has a single tuning parameter that determines graph width, which can also be eliminated by the way of additional computation. MISTICA outperforms existing alignment methods when applied to microscopy image sequences of mouse arteries.

Dual light field and polarization imaging using CMOS diffractive image sensors.

PubMed

Jayasuriya, Suren; Sivaramakrishnan, Sriram; Chuang, Ellen; Guruaribam, Debashree; Wang, Albert; Molnar, Alyosha

2015-05-15

In this Letter we present, to the best of our knowledge, the first integrated CMOS image sensor that can simultaneously perform light field and polarization imaging without the use of external filters or additional optical elements. Previous work has shown how photodetectors with two stacks of integrated metal gratings above them (called angle sensitive pixels) diffract light in a Talbot pattern to capture four-dimensional light fields. We show, in addition to diffractive imaging, that these gratings polarize incoming light and characterize the response of these sensors to polarization and incidence angle. Finally, we show two applications of polarization imaging: imaging stress-induced birefringence and identifying specular reflections in scenes to improve light field algorithms for these scenes.

Removing inter-subject technical variability in magnetic resonance imaging studies.

PubMed

Fortin, Jean-Philippe; Sweeney, Elizabeth M; Muschelli, John; Crainiceanu, Ciprian M; Shinohara, Russell T

2016-05-15

Magnetic resonance imaging (MRI) intensities are acquired in arbitrary units, making scans non-comparable across sites and between subjects. Intensity normalization is a first step for the improvement of comparability of the images across subjects. However, we show that unwanted inter-scan variability associated with imaging site, scanner effect, and other technical artifacts is still present after standard intensity normalization in large multi-site neuroimaging studies. We propose RAVEL (Removal of Artificial Voxel Effect by Linear regression), a tool to remove residual technical variability after intensity normalization. As proposed by SVA and RUV [Leek and Storey, 2007, 2008, Gagnon-Bartsch and Speed, 2012], two batch effect correction tools largely used in genomics, we decompose the voxel intensities of images registered to a template into a biological component and an unwanted variation component. The unwanted variation component is estimated from a control region obtained from the cerebrospinal fluid (CSF), where intensities are known to be unassociated with disease status and other clinical covariates. We perform a singular value decomposition (SVD) of the control voxels to estimate factors of unwanted variation. We then estimate the unwanted factors using linear regression for every voxel of the brain and take the residuals as the RAVEL-corrected intensities. We assess the performance of RAVEL using T1-weighted (T1-w) images from more than 900 subjects with Alzheimer's disease (AD) and mild cognitive impairment (MCI), as well as healthy controls from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. We compare RAVEL to two intensity-normalization-only methods: histogram matching and White Stripe. We show that RAVEL performs best at improving the replicability of the brain regions that are empirically found to be most associated with AD, and that these regions are significantly more present in structures impacted by AD (hippocampus, amygdala

Oil/water nano-emulsion loaded with cobalt ferrite oxide nanocubes for photo-acoustic and magnetic resonance dual imaging in cancer: in vitro and preclinical studies.

PubMed

Vecchione, Raffaele; Quagliariello, Vincenzo; Giustetto, Pierangela; Calabria, Dominic; Sathya, Ayyappan; Marotta, Roberto; Profeta, Martina; Nitti, Simone; Silvestri, Niccolò; Pellegrino, Teresa; Iaffaioli, Rosario V; Netti, Paolo Antonio

2017-01-01

Dual imaging dramatically improves detection and early diagnosis of cancer. In this work we present an oil in water (O/W) nano-emulsion stabilized with lecithin and loaded with cobalt ferrite oxide (Co 0.5 Fe 2.5 O 4 ) nanocubes for photo-acoustic and magnetic resonance dual imaging. The nanocarrier is responsive in in vitro photo-acoustic and magnetic resonance imaging (MRI) tests. A clear and significant time-dependent accumulation in tumor tissue is shown in in vivo photo-acoustic studies on a murine melanoma xenograft model. The proposed O/W nano-emulsion exhibits also high values of r 2 /r 1 (ranging from 45 to 85, depending on the magnetic field) suggesting a possible use as T 2 weighted image contrast agents. In addition, viability and cellular uptake studies show no significant cytotoxicity on the fibroblast cell line. We also tested the O/W nano-emulsion loaded with curcumin against melanoma cancer cells demonstrating a significant cytotoxicity and thus showing possible therapeutic effects in addition to the in vivo imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

Osteoporosis Imaging: State of the Art and Advanced Imaging

PubMed Central

2012-01-01

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures. © RSNA, 2012 PMID:22438439

Myocardial perfusion imaging with PET

PubMed Central

Nakazato, Ryo; Berman, Daniel S; Alexanderson, Erick; Slomka, Piotr

2013-01-01

PET-myocardial perfusion imaging (MPI) allows accurate measurement of myocardial perfusion, absolute myocardial blood flow and function at stress and rest in a single study session performed in approximately 30 min. Various PET tracers are available for MPI, and rubidium-82 or nitrogen-13-ammonia is most commonly used. In addition, a new fluorine-18-based PET-MPI tracer is currently being evaluated. Relative quantification of PET perfusion images shows very high diagnostic accuracy for detection of obstructive coronary artery disease. Dynamic myocardial blood flow analysis has demonstrated additional prognostic value beyond relative perfusion imaging. Patient radiation dose can be reduced and image quality can be improved with latest advances in PET/CT equipment. Simultaneous assessment of both anatomy and perfusion by hybrid PET/CT can result in improved diagnostic accuracy. Compared with SPECT-MPI, PET-MPI provides higher diagnostic accuracy, using lower radiation doses during a shorter examination time period for the detection of coronary artery disease. PMID:23671459

Deficits in agency in schizophrenia, and additional deficits in body image, body schema, and internal timing, in passivity symptoms.

PubMed

Graham, Kyran T; Martin-Iverson, Mathew T; Holmes, Nicholas P; Jablensky, Assen; Waters, Flavie

2014-01-01

Individuals with schizophrenia, particularly those with passivity symptoms, may not feel in control of their actions, believing them to be controlled by external agents. Cognitive operations that contribute to these symptoms may include abnormal processing in agency as well as body representations that deal with body schema and body image. However, these operations in schizophrenia are not fully understood, and the questions of general versus specific deficits in individuals with different symptom profiles remain unanswered. Using the projected-hand illusion (a digital video version of the rubber-hand illusion) with synchronous and asynchronous stroking (500 ms delay), and a hand laterality judgment task, we assessed sense of agency, body image, and body schema in 53 people with clinically stable schizophrenia (with a current, past, and no history of passivity symptoms) and 48 healthy controls. The results revealed a stable trait in schizophrenia with no difference between clinical subgroups (sense of agency) and some quantitative (specific) differences depending on the passivity symptom profile (body image and body schema). Specifically, a reduced sense of self-agency was a common feature of all clinical subgroups. However, subgroup comparisons showed that individuals with passivity symptoms (both current and past) had significantly greater deficits on tasks assessing body image and body schema, relative to the other groups. In addition, patients with current passivity symptoms failed to demonstrate the normal reduction in body illusion typically seen with a 500 ms delay in visual feedback (asynchronous condition), suggesting internal timing problems. Altogether, the results underscore self-abnormalities in schizophrenia, provide evidence for both trait abnormalities and state changes specific to passivity symptoms, and point to a role for internal timing deficits as a mechanistic explanation for external cues becoming a possible source of self-body input.

Noninvasive imaging of bone microarchitecture

PubMed Central

Patsch, Janina M.; Burghardt, Andrew J.; Kazakia, Galateia; Majumdar, Sharmila

2015-01-01

The noninvasive quantification of peripheral compartment-specific bone microarchitecture is feasible with high-resolution peripheral quantitative computed tomography (HR-pQCT) and high-resolution magnetic resonance imaging (HR-MRI). In addition to classic morphometric indices, both techniques provide a suitable basis for virtual biomechanical testing using finite element (FE) analyses. Methodical limitations, morphometric parameter definition, and motion artifacts have to be considered to achieve optimal data interpretation from imaging studies. With increasing availability of in vivo high-resolution bone imaging techniques, special emphasis should be put on quality control including multicenter, cross-site validations. Importantly, conclusions from interventional studies investigating the effects of antiosteoporotic drugs on bone microarchitecture should be drawn with care, ideally involving imaging scientists, translational researchers, and clinicians. PMID:22172043

Does pre-operative breast magnetic resonance imaging in addition to mammography and breast ultrasonography change the operative management of breast carcinoma?

PubMed

Lim, Hye In; Choi, Jae Hyuck; Yang, Jung-Hyun; Han, Boo-Kyung; Lee, Jeong Eon; Lee, Se-Kyung; Kim, Wan Wook; Kim, Sangmin; Kim, Jee Soo; Kim, Jung-Han; Choe, Jun-Ho; Cho, Eun Yoon; Kang, Seok Seon; Shin, Jung Hee; Ko, Eun Young; Kim, Sang Wook; Nam, Seok Jin

2010-01-01

Magnetic resonance imaging (MRI) has been used for the local staging of breast cancer, especially to determine the extent of multiple lesions and to identify occult malignancies. The aim of this study was to evaluate the effect of pre-operative MRI on the surgical treatment of breast cancer. Between January 2006 and May 2007, 535 newly diagnosed breast cancer patients who planned to undergo breast conserving surgery had clinical examinations, bilateral mammography, breast ultrasonography, and breast MRI. The radiologic findings and clinicopathologic data were reviewed retrospectively. Ninety-eight (18.3%) patients had additional lesions, shown as suspicious lesions on breast MRI, but not detected with conventional methods. Eighty-four (15.7%) of these patients had a change in surgical treatment plans based on the MRI results. Forty-seven (8.8%) of the 84 patients had additional malignancies;the other 37 patients (6.9%) had benign lesions. The positive predictive value for MRI-based surgery was 56.0% (47 of 84 patients). During the period of study, the use of pre-operative MRI was increased with time (OR 1.20; 95% CI 1.16-1.23; P < 0.001), but the mastectomy rate did not change significantly (OR 0.98; 95% CI 0.95-1.00; P = 0.059). Multiple factors were analyzed to identify the patients more likely to undergo appropriate and complete surgery based on the additional findings of the pre-operative MRI, but the results were not statistically significant. This research suggests that a pre-operative MRI can potentially lower the rate of incompletely excised malignancies by identifying additional occult cancer prior to surgery and does not lead to an increase in the mastectomy rate; however, because some benign lesions are indistinguishable from suspicious or malignant lesions, excessive surgical procedures are unnecessarily performed in a significant portion of patients. In the future, the criteria for the use of MRI in local staging of breast cancer should be established.

Standardized food images: A photographing protocol and image database.

PubMed

Charbonnier, Lisette; van Meer, Floor; van der Laan, Laura N; Viergever, Max A; Smeets, Paul A M

2016-01-01

The regulation of food intake has gained much research interest because of the current obesity epidemic. For research purposes, food images are a good and convenient alternative for real food because many dietary decisions are made based on the sight of foods. Food pictures are assumed to elicit anticipatory responses similar to real foods because of learned associations between visual food characteristics and post-ingestive consequences. In contemporary food science, a wide variety of images are used which introduces between-study variability and hampers comparison and meta-analysis of results. Therefore, we created an easy-to-use photographing protocol which enables researchers to generate high resolution food images appropriate for their study objective and population. In addition, we provide a high quality standardized picture set which was characterized in seven European countries. With the use of this photographing protocol a large number of food images were created. Of these images, 80 were selected based on their recognizability in Scotland, Greece and The Netherlands. We collected image characteristics such as liking, perceived calories and/or perceived healthiness ratings from 449 adults and 191 children. The majority of the foods were recognized and liked at all sites. The differences in liking ratings, perceived calories and perceived healthiness between sites were minimal. Furthermore, perceived caloric content and healthiness ratings correlated strongly (r ≥ 0.8) with actual caloric content in both adults and children. The photographing protocol as well as the images and the data are freely available for research use on http://nutritionalneuroscience.eu/. By providing the research community with standardized images and the tools to create their own, comparability between studies will be improved and a head-start is made for a world-wide standardized food image database. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Cognitive Semiotic Study of Students' Reading a Textless Image versus a Verbal Image

ERIC Educational Resources Information Center

Ali, Roaa Hasan; Aslaadi, Shatha

2016-01-01

This study explores fourth year college students' content retrieval from reading textless versus verbal images. Furthermore, it examines the extent to which the respondents comprehend and understand them. The procedures include selecting an image from the internet, designing a written test with its rubrics and exposing it to jury members to…

Comparison study of image quality and effective dose in dual energy chest digital tomosynthesis

NASA Astrophysics Data System (ADS)

Lee, Donghoon; Choi, Sunghoon; Lee, Haenghwa; Kim, Dohyeon; Choi, Seungyeon; Kim, Hee-Joung

2018-07-01

The present study aimed to introduce a recently developed digital tomosynthesis system for the chest and describe the procedure for acquiring dual energy bone decomposed tomosynthesis images. Various beam quality and reconstruction algorithms were evaluated for acquiring dual energy chest digital tomosynthesis (CDT) images and the effective dose was calculated with ion chamber and Monte Carlo simulations. The results demonstrated that dual energy CDT improved visualization of the lung field by eliminating the bony structures. In addition, qualitative and quantitative image quality of dual energy CDT using iterative reconstruction was better than that with filtered backprojection (FBP) algorithm. The contrast-to-noise ratio and figure of merit values of dual energy CDT acquired with iterative reconstruction were three times better than those acquired with FBP reconstruction. The difference in the image quality according to the acquisition conditions was not noticeable, but the effective dose was significantly affected by the acquisition condition. The high energy acquisition condition using 130 kVp recorded a relatively high effective dose. We conclude that dual energy CDT has the potential to compensate for major problems in CDT due to decomposed bony structures, which induce significant artifacts. Although there are many variables in the clinical practice, our results regarding reconstruction algorithms and acquisition conditions may be used as the basis for clinical use of dual energy CDT imaging.

Retinal Image Quality Assessment for Spaceflight-Induced Vision Impairment Study

NASA Technical Reports Server (NTRS)

Vu, Amanda Cadao; Raghunandan, Sneha; Vyas, Ruchi; Radhakrishnan, Krishnan; Taibbi, Giovanni; Vizzeri, Gianmarco; Grant, Maria; Chalam, Kakarla; Parsons-Wingerter, Patricia

2015-01-01

Long-term exposure to space microgravity poses significant risks for visual impairment. Evidence suggests such vision changes are linked to cephalad fluid shifts, prompting a need to directly quantify microgravity-induced retinal vascular changes. The quality of retinal images used for such vascular remodeling analysis, however, is dependent on imaging methodology. For our exploratory study, we hypothesized that retinal images captured using fluorescein imaging methodologies would be of higher quality in comparison to images captured without fluorescein. A semi-automated image quality assessment was developed using Vessel Generation Analysis (VESGEN) software and MATLAB® image analysis toolboxes. An analysis of ten images found that the fluorescein imaging modality provided a 36% increase in overall image quality (two-tailed p=0.089) in comparison to nonfluorescein imaging techniques.

Performance of residents using digital images versus glass slides on certification examination in anatomical pathology: a mixed methods pilot study

PubMed Central

Mirham, Lorna; Naugler, Christopher; Hayes, Malcolm; Ismiil, Nadia; Belisle, Annie; Sade, Shachar; Streutker, Catherine; MacMillan, Christina; Rasty, Golnar; Popovic, Snezana; Joseph, Mariamma; Gabril, Manal; Barnes, Penny; Hegele, Richard G.; Carter, Beverley; Yousef, George M.

2016-01-01

Background: It is anticipated that many licensing examination centres for pathology will begin fully digitizing the certification examinations. The objective of our study was to test the feasibility of a fully digital examination and to assess the needs, concerns and expectations of pathology residents in moving from a glass slide-based examination to a fully digital examination. Methods: We conducted a mixed methods study that compared, after randomization, the performance of senior residents (postgraduate years 4 and 5) in 7 accredited anatomical pathology training programs across Canada on a pathology examination using either glass slides or digital whole-slide scanned images of the slides. The pilot examination was followed by a post-test survey. In addition, pathology residents from all levels of training were invited to participate in an online survey. Results: A total of 100 residents participated in the pilot examination; 49 were given glass slides instead of digital images. We found no significant difference in examination results between the 2 groups of residents (estimated marginal mean 8.23/12, 95% confidence interval [CI] 7.72-8.87, for glass slides; 7.84/12, 95% CI 7.28-8.41, for digital slides). In the post-test survey, most of the respondents expressed concerns with the digital examination, including slowly functioning software, blurring and poor detail of images, particularly nuclear features. All of the respondents of the general survey (n = 179) agreed that additional training was required if the examination were to become fully digital. Interpretation: Although the performance of residents completing pathology examinations with glass slides was comparable to that of residents using digital images, our study showed that residents were not comfortable with the digital technology, especially given their current level of exposure to it. Additional training may be needed before implementing a fully digital examination, with consideration for a

Computer-aided detection of brain metastasis on 3D MR imaging: Observer performance study.

PubMed

Sunwoo, Leonard; Kim, Young Jae; Choi, Seung Hong; Kim, Kwang-Gi; Kang, Ji Hee; Kang, Yeonah; Bae, Yun Jung; Yoo, Roh-Eul; Kim, Jihang; Lee, Kyong Joon; Lee, Seung Hyun; Choi, Byung Se; Jung, Cheolkyu; Sohn, Chul-Ho; Kim, Jae Hyoung

2017-01-01

To assess the effect of computer-aided detection (CAD) of brain metastasis (BM) on radiologists' diagnostic performance in interpreting three-dimensional brain magnetic resonance (MR) imaging using follow-up imaging and consensus as the reference standard. The institutional review board approved this retrospective study. The study cohort consisted of 110 consecutive patients with BM and 30 patients without BM. The training data set included MR images of 80 patients with 450 BM nodules. The test set included MR images of 30 patients with 134 BM nodules and 30 patients without BM. We developed a CAD system for BM detection using template-matching and K-means clustering algorithms for candidate detection and an artificial neural network for false-positive reduction. Four reviewers (two neuroradiologists and two radiology residents) interpreted the test set images before and after the use of CAD in a sequential manner. The sensitivity, false positive (FP) per case, and reading time were analyzed. A jackknife free-response receiver operating characteristic (JAFROC) method was used to determine the improvement in the diagnostic accuracy. The sensitivity of CAD was 87.3% with an FP per case of 302.4. CAD significantly improved the diagnostic performance of the four reviewers with a figure-of-merit (FOM) of 0.874 (without CAD) vs. 0.898 (with CAD) according to JAFROC analysis (p < 0.01). Statistically significant improvement was noted only for less-experienced reviewers (FOM without vs. with CAD, 0.834 vs. 0.877, p < 0.01). The additional time required to review the CAD results was approximately 72 sec (40% of the total review time). CAD as a second reader helps radiologists improve their diagnostic performance in the detection of BM on MR imaging, particularly for less-experienced reviewers.

[A computer-aided image diagnosis and study system].

PubMed

Li, Zhangyong; Xie, Zhengxiang

2004-08-01

The revolution in information processing, particularly the digitizing of medicine, has changed the medical study, work and management. This paper reports a method to design a system for computer-aided image diagnosis and study. Combined with some good idea of graph-text system and picture archives communicate system (PACS), the system was realized and used for "prescription through computer", "managing images" and "reading images under computer and helping the diagnosis". Also typical examples were constructed in a database and used to teach the beginners. The system was developed by the visual developing tools based on object oriented programming (OOP) and was carried into operation on the Windows 9X platform. The system possesses friendly man-machine interface.

Longitudinal study of arteriogenesis with swept source optical coherence tomography and hyperspectral imaging

NASA Astrophysics Data System (ADS)

Poole, Kristin M.; Patil, Chetan A.; Nelson, Christopher E.; McCormack, Devin R.; Madonna, Megan C.; Duvall, Craig L.; Skala, Melissa C.

2014-03-01

Peripheral arterial disease (PAD) is an atherosclerotic disease of the extremities that leads to high rates of myocardial infarction and stroke, increased mortality, and reduced quality of life. PAD is especially prevalent in diabetic patients, and is commonly modeled by hind limb ischemia in mice to study collateral vessel development and test novel therapies. Current techniques used to assess recovery cannot obtain quantitative, physiological data non-invasively. Here, we have applied hyperspectral imaging and swept source optical coherence tomography (OCT) to study longitudinal changes in blood oxygenation and vascular morphology, respectively, intravitally in the diabetic mouse hind limb ischemia model. Additionally, recommended ranges for controlling physiological variability in blood oxygenation with respect to respiration rate and body core temperature were determined from a control animal experiment. In the longitudinal study with diabetic mice, hyperspectral imaging data revealed the dynamics of blood oxygenation recovery distally in the ischemic footpad. In diabetic mice, there is an early increase in oxygenation that is not sustained in the long term. Quantitative analysis of vascular morphology obtained from Hessian-filtered speckle variance OCT volumes revealed temporal dynamics in vascular density, total vessel length, and vessel diameter distribution in the adductor muscle of the ischemic limb. The combination of hyperspectral imaging and speckle variance OCT enabled acquisition of novel functional and morphological endpoints from individual animals, and provides a more robust platform for future preclinical evaluations of novel therapies for PAD.

One-stop-shop preoperative evaluation for living liver donors with gadoxetic acid disodium-enhanced magnetic resonance imaging: efficiency and additional benefit.

PubMed

Xie, Shuangshuang; Liu, Chenhao; Yu, Zichuan; Ren, Tao; Hou, Jiancun; Chen, Lihua; Huang, Lixiang; Cheng, Yue; Ji, Qian; Yin, Jianzhong; Zhang, Longjiang; Shen, Wen

2015-12-01

To explore the efficiency, cost, and time for examination of one-stop-shop gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in preoperative evaluation for parent donors by comparing with multidetector computer tomography combined with conventional MR cholangiopancreatography (MDCT-MRCP). Forty parent donors were evaluated with MDCT-MRCP, and the other 40 sex-, age-, and weight-matched donors with Gd-EOB-DTPA-enhanced MRI. Anatomical variations and graft volume determined by pre- and intra-operative findings, costs and time for imaging were recorded. Image quality was ranked on a 4-point scale and compared between both groups. Gd-EOB-DTPA-enhanced MRI provided better image quality than MDCT-MRCP for the depiction of portal veins and bile ducts by both reviewers (p < 0.05), hepatic veins by one reviewer (p < 0.05), rather hepatic arteries by both reviewers (p < 0.01). Sixty-nine living donors proceeded to liver donation with all anatomical findings accurately confirmed by intra-operative findings. The "in-room" time of Gd-EOB-DTPA-enhanced MRI was 12 min longer than MDCT-MRCP. Gd-EOB-DTPA-enhanced MRI was cheaper than MDCT-MRCP (US$519.72 vs. US$631.85). One-stop-shop Gd-EOB-DTPA-enhanced MRI has similar diagnostic accuracy as MDCT-MRCP and can provide additional benefit in terms of costs and convenience in preoperative evaluation for parent donors. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Phase 1/2 Study of the Addition of Cisplatin to Adjuvant Chemotherapy With Image Guided High-Precision Radiation Therapy for Completely Resected Gastric Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goody, Rebecca B.; MacKay, Helen; Pitcher, Bethany

Purpose: Locoregional recurrence is common after surgery for gastric cancer. Adjuvant therapy improves outcomes but with toxicity. This phase 1/2 study investigated infusional 5-fluorouracil (5-FU) in combination with biweekly cisplatin delivered concurrently with image guided high-precision radiation therapy. Methods and Materials: Eligible patients had completely resected stage IB to IV (Union for International Cancer Control TNM 6th edition) nonmetastatic gastric adenocarcinoma. Treatment constituted 12 weeks of infusional 5-FU (200 mg/m{sup 2}/day) with cisplatin added in a standard 3 + 3 dose escalation protocol (0, 20, 30, and 40 mg/m{sup 2}) during weeks 1, 3, 5, and 7, and an additional week 9 dose in themore » final cohort. Radiation therapy (45 Gy in 25 fractions) was delivered during weeks 3 to 7. Maximum tolerated dose (MTD) was determined in phase 1 and confirmed in phase 2. Results: Among the 55 patients (median age, 54 years; range 28-77 years; 55% male), the median follow-up time was 3.0 years (range, 0.3-5.3 years). Five patients in phase 1 experienced dose-limiting toxicity, and MTD was determined as 4 cycles of 40 mg/m{sup 2} cisplatin. Twenty-seven patients were treated at MTD. Acute grade 3 to 4 toxicity rate was 37.0% at MTD and 29.1% across all dose levels. No treatment-related deaths occurred. Fourteen patients experienced recurrent disease. The 2-year overall survival (OS) and relapse-free survival were 85% and 74%, respectively. Median OS has not been reached. Quality of life (QOL) was impaired during treatment, but most scores recovered by 4 weeks. Conclusion: Cisplatin can be safely delivered with 5-FU–based chemoradiation therapy. Acute toxicity was acceptable, and patient-reported QOL showed the regimen was tolerable. Outcomes are encouraging and justify further study of this regimen.« less

Deformable Medical Image Registration: A Survey

PubMed Central

Sotiras, Aristeidis; Davatzikos, Christos; Paragios, Nikos

2013-01-01

Deformable image registration is a fundamental task in medical image processing. Among its most important applications, one may cite: i) multi-modality fusion, where information acquired by different imaging devices or protocols is fused to facilitate diagnosis and treatment planning; ii) longitudinal studies, where temporal structural or anatomical changes are investigated; and iii) population modeling and statistical atlases used to study normal anatomical variability. In this paper, we attempt to give an overview of deformable registration methods, putting emphasis on the most recent advances in the domain. Additional emphasis has been given to techniques applied to medical images. In order to study image registration methods in depth, their main components are identified and studied independently. The most recent techniques are presented in a systematic fashion. The contribution of this paper is to provide an extensive account of registration techniques in a systematic manner. PMID:23739795

Multispectral open-air intraoperative fluorescence imaging.

PubMed

Behrooz, Ali; Waterman, Peter; Vasquez, Kristine O; Meganck, Jeff; Peterson, Jeffrey D; Faqir, Ilias; Kempner, Joshua

2017-08-01

Intraoperative fluorescence imaging informs decisions regarding surgical margins by detecting and localizing signals from fluorescent reporters, labeling targets such as malignant tissues. This guidance reduces the likelihood of undetected malignant tissue remaining after resection, eliminating the need for additional treatment or surgery. The primary challenges in performing open-air intraoperative fluorescence imaging come from the weak intensity of the fluorescence signal in the presence of strong surgical and ambient illumination, and the auto-fluorescence of non-target components, such as tissue, especially in the visible spectral window (400-650 nm). In this work, a multispectral open-air fluorescence imaging system is presented for translational image-guided intraoperative applications, which overcomes these challenges. The system is capable of imaging weak fluorescence signals with nanomolar sensitivity in the presence of surgical illumination. This is done using synchronized fluorescence excitation and image acquisition with real-time background subtraction. Additionally, the system uses a liquid crystal tunable filter for acquisition of multispectral images that are used to spectrally unmix target fluorescence from non-target auto-fluorescence. Results are validated by preclinical studies on murine models and translational canine oncology models.

Multiple enface image averaging for enhanced optical coherence tomography angiography imaging.

PubMed

Uji, Akihito; Balasubramanian, Siva; Lei, Jianqin; Baghdasaryan, Elmira; Al-Sheikh, Mayss; Borrelli, Enrico; Sadda, SriniVas R

2018-05-31

To investigate the effect of multiple enface image averaging on image quality of the optical coherence tomography angiography (OCTA). Twenty-one normal volunteers were enrolled in this study. For each subject, one eye was imaged with 3 × 3 mm scan protocol, and another eye was imaged with the 6 × 6 mm scan protocol centred on the fovea using the ZEISS Angioplex™ spectral-domain OCTA device. Eyes were repeatedly imaged to obtain nine OCTA cube scan sets, and nine superficial capillary plexus (SCP) and deep capillary plexus (DCP) were individually averaged after registration. Eighteen eyes with a 3 × 3 mm scan field and 14 eyes with a 6 × 6 mm scan field were studied. Averaged images showed more continuous vessels and less background noise in both the SCP and the DCP as the number of frames used for averaging increased, with both 3 × 3 and 6 × 6 mm scan protocols. The intensity histogram of the vessels dramatically changed after averaging. Contrast-to-noise ratio (CNR) and subjectively assessed image quality scores also increased as the number of frames used for averaging increased in all image types. However, the additional benefit in quality diminished when averaging more than five frames. Averaging only three frames achieved significant improvement in CNR and the score assigned by certified grades. Use of multiple image averaging in OCTA enface images was found to be both objectively and subjectively effective for enhancing image quality. These findings may of value for developing optimal OCTA imaging protocols for future studies. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Narrow band imaging versus autofluorescence imaging for head and neck squamous cell carcinoma detection: a prospective study.

PubMed

Ni, X-G; Zhang, Q-Q; Wang, G-Q

2016-11-01

This study aimed to compare the diagnostic effectiveness of narrow band imaging and autofluorescence imaging for malignant laryngopharyngeal tumours. Between May 2010 and October 2010, 50 consecutive patients with suspected laryngopharyngeal tumour underwent endoscopic laryngopharynx examination. The morphological characteristics of laryngopharyngeal lesions were analysed using high performance endoscopic systems equipped with narrow band imaging and autofluorescence imaging modes. The diagnostic effectiveness of white light image, narrow band imaging and autofluorescence imaging endoscopy for benign and malignant laryngopharyngeal lesions was evaluated. Under narrow band imaging endoscopy, the superficial microvessels of squamous cell carcinomas appeared as dark brown spots or twisted cords. Under autofluorescence imaging endoscopy, malignant lesions appeared as bright purple. The sensitivity of malignant lesion diagnosis was not significantly different between narrow band imaging and autofluorescence imaging modes, but was better than for white light image endoscopy (χ2 = 12.676, p = 0.002). The diagnostic specificity was significantly better in narrow band imaging mode than in both autofluorescence imaging and white light imaging mode (χ2 = 8.333, p = 0.016). Narrow band imaging endoscopy is the best option for the diagnosis and differential diagnosis of laryngopharyngeal tumours.

Brain Imaging and Human Nutrition: Which Measures to Use in Intervention Studies?12

PubMed Central

Sizonenko, Stéphane V.; Babiloni, Claudio; Sijben, John W.; Walhovd, Kristine B.

2013-01-01

Throughout the life span, the brain is a metabolically highly active organ that uses a large proportion of total nutrient and energy intake. Furthermore, the development and repair of neural tissue depend on the proper intake of essential structural nutrients, minerals, and vitamins. Therefore, what we eat, or refrain from eating, may have an important impact on our cognitive ability and mental performance. Two of the key areas in which diet is thought to play an important role are in optimizing neurodevelopment in children and in preventing neurodegeneration and cognitive decline during aging. From early development to aging, brain imaging can detect structural, functional, and metabolic changes in humans and modifications due to altered nutrition or to additional nutritional supplementation. Inclusion of imaging measures in clinical studies can increase understanding with regard to the modification of brain structure, metabolism, and functional endpoints and may provide early sensitive measures of long-term effects. In this symposium, the utility of existing brain imaging technologies to assess the effects of nutritional intervention in humans is described. Examples of current research showing the utility of these markers are reviewed. PMID:24038255

Deformable image registration with content mismatch: a demons variant to account for added material and surgical devices in the target image

NASA Astrophysics Data System (ADS)

Nithiananthan, S.; Uneri, A.; Schafer, S.; Mirota, D.; Otake, Y.; Stayman, J. W.; Zbijewski, W.; Khanna, A. J.; Reh, D. D.; Gallia, G. L.; Siewerdsen, J. H.

2013-03-01

Fast, accurate, deformable image registration is an important aspect of image-guided interventions. Among the factors that can confound registration is the presence of additional material in the intraoperative image - e.g., contrast bolus or a surgical implant - that was not present in the prior image. Existing deformable registration methods generally fail to account for tissue excised between image acquisitions and typically simply "move" voxels within the images with no ability to account for tissue that is removed or introduced between scans. We present a variant of the Demons algorithm to accommodate such content mismatch. The approach combines segmentation of mismatched content with deformable registration featuring an extra pseudo-spatial dimension representing a reservoir from which material can be drawn into the registered image. Previous work tested the registration method in the presence of tissue excision ("missing tissue"). The current paper tests the method in the presence of additional material in the target image and presents a general method by which either missing or additional material can be accommodated. The method was tested in phantom studies, simulations, and cadaver models in the context of intraoperative cone-beam CT with three examples of content mismatch: a variable-diameter bolus (contrast injection); surgical device (rod), and additional material (bone cement). Registration accuracy was assessed in terms of difference images and normalized cross correlation (NCC). We identify the difficulties that traditional registration algorithms encounter when faced with content mismatch and evaluate the ability of the proposed method to overcome these challenges.

Imaging phased telescope array study

NASA Technical Reports Server (NTRS)

Harvey, James E.

1989-01-01

The problems encountered in obtaining a wide field-of-view with large, space-based direct imaging phased telescope arrays were considered. After defining some of the critical systems issues, previous relevant work in the literature was reviewed and summarized. An extensive list was made of potential error sources and the error sources were categorized in the form of an error budget tree including optical design errors, optical fabrication errors, assembly and alignment errors, and environmental errors. After choosing a top level image quality requirment as a goal, a preliminary tops-down error budget allocation was performed; then, based upon engineering experience, detailed analysis, or data from the literature, a bottoms-up error budget reallocation was performed in an attempt to achieve an equitable distribution of difficulty in satisfying the various allocations. This exercise provided a realistic allocation for residual off-axis optical design errors in the presence of state-of-the-art optical fabrication and alignment errors. Three different computational techniques were developed for computing the image degradation of phased telescope arrays due to aberrations of the individual telescopes. Parametric studies and sensitivity analyses were then performed for a variety of subaperture configurations and telescope design parameters in an attempt to determine how the off-axis performance of a phased telescope array varies as the telescopes are scaled up in size. The Air Force Weapons Laboratory (AFWL) multipurpose telescope testbed (MMTT) configuration was analyzed in detail with regard to image degradation due to field curvature and distortion of the individual telescopes as they are scaled up in size.

Relearning To Teach Arithmetic Addition and Subtraction: A Teacher's Study Guide.

ERIC Educational Resources Information Center

Russell, Susan Jo

This package features videotapes and a study guide that are designed to help teachers revisit the operations of addition and subtraction and consider how students can develop meaningful approaches to these operations. The study guides' sessions are on addition, subtraction, the teacher's role, and goals for students and teachers. The readings in…

Image quality and radiation dose on digital chest imaging: comparison of amorphous silicon and amorphous selenium flat-panel systems.

PubMed

Bacher, Klaus; Smeets, Peter; Vereecken, Ludo; De Hauwere, An; Duyck, Philippe; De Man, Robert; Verstraete, Koenraad; Thierens, Hubert

2006-09-01

The aim of this study was to compare the image quality and radiation dose in chest imaging using an amorphous silicon flat-panel detector system and an amorphous selenium flat-panel detector system. In addition, the low-contrast performance of both systems with standard and low radiation doses was compared. In two groups of 100 patients each, digital chest radiographs were acquired with either an amorphous silicon or an amorphous selenium flat-panel system. The effective dose of the examination was measured using thermoluminescent dosimeters placed in an anthropomorphic Rando phantom. The image quality of the digital chest radiographs was assessed by five experienced radiologists using the European Guidelines on Quality Criteria for Diagnostic Radiographic Images. In addition, a contrast-detail phantom study was set up to assess the low-contrast performance of both systems at different radiation dose levels. Differences between the two groups were tested for significance using the two-tailed Mann-Whitney test. The amorphous silicon flat-panel system allowed an important and significant reduction in effective dose in comparison with the amorphous selenium flat-panel system (p < 0.0001) for both the posteroanterior and lateral views. In addition, clinical image quality analysis showed that the dose reduction was not detrimental to image quality. Compared with the amorphous selenium flat-panel detector system, the amorphous silicon flat-panel detector system performed significantly better in the low-contrast phantom study, with phantom entrance dose values of up to 135 muGy. Chest radiographs can be acquired with a significantly lower patient radiation dose using an amorphous silicon flat-panel system than using an amorphous selenium flat-panel system, thereby producing images that are equal or even superior in quality to those of the amorphous selenium flat-panel detector system.

Perspective: Advanced particle imaging

DOE PAGES

Chandler, David W.; Houston, Paul L.; Parker, David H.

2017-05-26

This study discuss, the first ion imaging experiment demonstrating the capability of collecting an image of the photofragments from a unimolecular dissociation event and analyzing that image to obtain the three-dimensional velocity distribution of the fragments, the efficacy and breadth of application of the ion imaging technique have continued to improve and grow. With the addition of velocity mapping, ion/electron centroiding, and slice imaging techniques, the versatility and velocity resolution have been unmatched. Recent improvements in molecular beam, laser, sensor, and computer technology are allowing even more advanced particle imaging experiments, and eventually we can expect multi-mass imaging with co-variancemore » and full coincidence capability on a single shot basis with repetition rates in the kilohertz range. This progress should further enable “complete” experiments—the holy grail of molecular dynamics—where all quantum numbers of reactants and products of a bimolecular scattering event are fully determined and even under our control.« less

Health IT and inappropriate utilization of outpatient imaging: A cross-sectional study of U.S. hospitals.

PubMed

Appari, Ajit; Johnson, M Eric; Anthony, Denise L

2018-01-01

To determine whether the use of information technology (IT), measured by Meaningful Use capability, is associated with lower rates of inappropriate utilization of imaging services in hospital outpatient settings. A retrospective cross-sectional analysis of 3332 nonfederal U.S. hospitals using data from: Hospital Compare (2011 outpatient imaging efficiency measures), HIMSS Analytics (2009 health IT), and Health Indicator Warehouse (market characteristics). Hospitals were categorized for their health IT infrastructure including EHR Stage-1 capability, and three advanced imaging functionalities/systems including integrated picture archiving and communication system, Web-based image distribution, and clinical decision support (CDS) with physician pathways. Three imaging efficiency measures suggesting inappropriate utilization during 2011 included: percentage of "combined" (with and without contrast) computed tomography (CT) studies out of all CT studies for abdomen and chest respectively, and percentage of magnetic resonance imaging (MRI) studies of lumbar spine without antecedent conservative therapy within 60days. For each measure, three separate regression models (GLM with gamma-log link function, and denominator of imaging measure as exposure) were estimated adjusting for hospital characteristics, market characteristics, and state fixed effects. Additionally, Heckman's Inverse Mills Ratio and propensity for Stage-1 EHR capability were used to account for selection bias. We find support for association of each of the four health IT capabilities with inappropriate utilization rates of one or more imaging modality. Stage-1 EHR capability is associated with lower inappropriate utilization rates for chest CT (incidence rate ratio IRR=0.72, p-value <0.01) and lumbar MRI (IRR=0.87, p-value <0.05). Integrated PACS is associated with lower inappropriate utilization rate of abdomen CT (IRR=0.84, p-value <0.05). Imaging distribution over Web capability is associated with

An Integrated System for Superharmonic Contrast-Enhanced Ultrasound Imaging: Design and Intravascular Phantom Imaging Study.

PubMed

Li, Yang; Ma, Jianguo; Martin, K Heath; Yu, Mingyue; Ma, Teng; Dayton, Paul A; Jiang, Xiaoning; Shung, K Kirk; Zhou, Qifa

2016-09-01

Superharmonic contrast-enhanced ultrasound imaging, also called acoustic angiography, has previously been used for the imaging of microvasculature. This approach excites microbubble contrast agents near their resonance frequency and receives echoes at nonoverlapping superharmonic bandwidths. No integrated system currently exists could fully support this application. To fulfill this need, an integrated dual-channel transmit/receive system for superharmonic imaging was designed, built, and characterized experimentally. The system was uniquely designed for superharmonic imaging and high-resolution B-mode imaging. A complete ultrasound system including a pulse generator, a data acquisition unit, and a signal processing unit were integrated into a single package. The system was controlled by a field-programmable gate array, on which multiple user-defined modes were implemented. A 6-, 35-MHz dual-frequency dual-element intravascular ultrasound transducer was designed and used for imaging. The system successfully obtained high-resolution B-mode images of coronary artery ex vivo with 45-dB dynamic range. The system was capable of acquiring in vitro superharmonic images of a vasa vasorum mimicking phantom with 30-dB contrast. It could detect a contrast agent filled tissue mimicking tube of 200 μm diameter. For the first time, high-resolution B-mode images and superharmonic images were obtained in an intravascular phantom, made possible by the dedicated integrated system proposed. The system greatly reduced the cost and complexity of the superharmonic imaging intended for preclinical study. Significant: The system showed promise for high-contrast intravascular microvascular imaging, which may have significant importance in assessment of the vasa vasorum associated with atherosclerotic plaques.

Study on Over-Sampling for Imager

NASA Technical Reports Server (NTRS)

Kigawa, Seiichiro; Sullivan, Pamela C.

1998-01-01

This report describes the potential improvement of the effective ground resolution of MTSAT (Multi-functional Transport Satellite) Imager. The IFOV (Instantaneous Field of View) of MTSAT Imager is 4 km for infrared and 1 km visible. A combination of some images acquired by the MTSAT Imager could generate 2 km-latticed infrared images. Furthermore, it is possible to generate an effective 2 km IFOV image by the enhancement of the 2 km-latticed image using Digital Signal Processing. This report also mentions the on-orbit demonstration of this concept.

A comparative study of scintillator combining methods for flat-panel X-ray image sensors

NASA Astrophysics Data System (ADS)

Kim, M. S.; Lim, K. T.; Kim, G.; Cho, G.

2018-02-01

An X-ray transmission imaging based on scintillation detection method is the most widely used radiation technique particularly in the medical and industrial areas. As the name suggests, scintillation detection uses a scintillator as an intermediate material to convert incoming radiation into visible-light particles. Among different types of scintillators, CsI(Tl) in a columnar configuration is the most popular type used for applications that require an energy less than 150 keV due to its capability in obtaining a high spatial resolution with a reduced light spreading effect. In this study, different methods in combining a scintillator with a light-receiving unit are investigated and their relationships are given in terms of the image quality. Three different methods of combining a scintillator with a light-receiving unit are selected to investigate their performance in X-ray imaging: upward or downward oriented needles structure of CsI(Tl), coating layer deposition around CsI(Tl), and insertion of FOP. A charge-coupled device was chosen to serve as the light-receiving unit for the proposed system. From the result, the difference of needle directions in CsI(Tl) had no significant effects in the X-ray image. In contrast, deposition of the coating material around CsI(Tl) showed 17.3% reduction in the DQE. Insertion of the FOP increased the spatial resolution by 38%, however, it decreased the light yield in the acquired image by 56%. In order to have the maximum scintillation performance in X-ray imaging, not only the reflection material but also the bonding method must be considered when combining the scintillator with the light-receiving unit. In addition, the use of FOP should be carefully decided based on the purpose of X-ray imaging, e.g., image sharpness or SNR.

Comparative analysis of image classification methods for automatic diagnosis of ophthalmic images

NASA Astrophysics Data System (ADS)

Wang, Liming; Zhang, Kai; Liu, Xiyang; Long, Erping; Jiang, Jiewei; An, Yingying; Zhang, Jia; Liu, Zhenzhen; Lin, Zhuoling; Li, Xiaoyan; Chen, Jingjing; Cao, Qianzhong; Li, Jing; Wu, Xiaohang; Wang, Dongni; Li, Wangting; Lin, Haotian

2017-01-01

There are many image classification methods, but it remains unclear which methods are most helpful for analyzing and intelligently identifying ophthalmic images. We select representative slit-lamp images which show the complexity of ocular images as research material to compare image classification algorithms for diagnosing ophthalmic diseases. To facilitate this study, some feature extraction algorithms and classifiers are combined to automatic diagnose pediatric cataract with same dataset and then their performance are compared using multiple criteria. This comparative study reveals the general characteristics of the existing methods for automatic identification of ophthalmic images and provides new insights into the strengths and shortcomings of these methods. The relevant methods (local binary pattern +SVMs, wavelet transformation +SVMs) which achieve an average accuracy of 87% and can be adopted in specific situations to aid doctors in preliminarily disease screening. Furthermore, some methods requiring fewer computational resources and less time could be applied in remote places or mobile devices to assist individuals in understanding the condition of their body. In addition, it would be helpful to accelerate the development of innovative approaches and to apply these methods to assist doctors in diagnosing ophthalmic disease.

O-space with high resolution readouts outperforms radial imaging.

PubMed

Wang, Haifeng; Tam, Leo; Kopanoglu, Emre; Peters, Dana C; Constable, R Todd; Galiana, Gigi

2017-04-01

While O-Space imaging is well known to accelerate image acquisition beyond traditional Cartesian sampling, its advantages compared to undersampled radial imaging, the linear trajectory most akin to O-Space imaging, have not been detailed. In addition, previous studies have focused on ultrafast imaging with very high acceleration factors and relatively low resolution. The purpose of this work is to directly compare O-Space and radial imaging in their potential to deliver highly undersampled images of high resolution and minimal artifacts, as needed for diagnostic applications. We report that the greatest advantages to O-Space imaging are observed with extended data acquisition readouts. A sampling strategy that uses high resolution readouts is presented and applied to compare the potential of radial and O-Space sequences to generate high resolution images at high undersampling factors. Simulations and phantom studies were performed to investigate whether use of extended readout windows in O-Space imaging would increase k-space sampling and improve image quality, compared to radial imaging. Experimental O-Space images acquired with high resolution readouts show fewer artifacts and greater sharpness than radial imaging with equivalent scan parameters. Radial images taken with longer readouts show stronger undersampling artifacts, which can cause small or subtle image features to disappear. These features are preserved in a comparable O-Space image. High resolution O-Space imaging yields highly undersampled images of high resolution and minimal artifacts. The additional nonlinear gradient field improves image quality beyond conventional radial imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

Functional Brain Imaging

PubMed Central

2006-01-01

Database of Systematic Reviews, CENTRAL, and International Network of Agencies for Health Technology Assessment (INAHTA). The database search was supplemented with a search of relevant Web sites and a review of the bibliographies of selected papers. General inclusion criteria were applied to all conditions. Those criteria included the following: Full reports of systematic reviews, randomized controlled trials (RCTs), cohort-control studies, prospective cohort studies (PCS’), and retrospective studies. Sample sizes of at least 20 patients (≥ 10 with condition being reviewed). English-language studies. Human studies. Any age. Studying at least one of the following: fMRI, PET, MRS, or MEG. Functional brain imaging modality must be compared with a clearly defined reference standard. Must report at least one of the following outcomes: sensitivity, specificity, accuracy, positive predictive value (PPV), receiver operating characteristic curve, outcome measuring impact on diagnostic testing, treatment, patient health, or cost. Summary of Findings There is evidence to indicate that PET can accurately diagnose AD; however, at this time, there is no evidence to suggest that a diagnosis of AD with PET alters the clinical outcomes of patients. The addition of MRS or O-(2-18F-Fluoroethyl)-L-Tyrosine (FET)-PET to gadolinium (Gd)-enhanced MRI for distinguishing malignant from benign tumours during primary diagnosis may provide a higher specificity than Gd-enhanced MRI alone. The clinical utility of additional imaging in patients to distinguish malignant from benign tumours is unclear, because patients with a suspected brain tumour will likely undergo a biopsy despite additional imaging results. The addition of MRS, FET-PET, or MRI T2 to Gd-enhanced MRI for the differentiation of recurrence from radiation necrosis may provide a higher specificity than Gd-enhanced MRI alone. The clinical utility of additional imaging in patients with a suspected recurrence is in the monitoring of

Functional Generalized Additive Models.

PubMed

McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

2014-01-01

We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F { X ( t ), t } where F (·,·) is an unknown regression function and X ( t ) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F (·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X ( t ) is a signal from diffusion tensor imaging at position, t , along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online.

Comparative Study Of Image Enhancement Algorithms For Digital And Film Mammography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delgado-Gonzalez, A.; Sanmiguel, R. E.

2008-08-11

Here we discuss the application of edge enhancement algorithms on images obtained with a Mammography System which has a Selenium Detector and on the other hand, on images obtained from digitized film mammography. Comparative analysis of such images includes the study of technical aspects of image acquisition, storage, compression and display. A protocol for a local database has been created as a result of this study.

Tri-stereo Pleiades images-derived digital surface models for tectonic geomorphology studies

NASA Astrophysics Data System (ADS)

Ferry, Matthieu; Le Roux-Mallouf, Romain; Ritz, Jean-François; Berthet, Théo; Peyret, Michel; Vernant, Philippe; Maréchal, Anaïs; Cattin, Rodolphe; Mazzotti, Stéphane; Poujol, Antoine

2014-05-01

Very high resolution digital elevation models are a key component of modern quantitative geomorphology. In parallel to high-precision but time-consuming kinematic GPS and/or total station surveys and dense coverage but expensive LiDAR campaigns, we explore the usability of affordable, flexible, wide coverage digital surface models (DSMs) derived from Pleiades tri-stereo optical images. We present two different approaches to extract DSM from a triplet of images. The first relies on the photogrammetric extraction of 3 DSMs from the 3 possible stereo couples and subsequent merge based on the best correlation score. The second takes advantage of simultaneous correlation over the 3 images to derive a point cloud. We further extract DSM from panchromatic 0.5 m resolution images and multispectral 2 m resolution images to test for correlation and noise and determine optimal correlation window size and achievable resolution. Georeferencing is also assessed by comparing raw coordinates derived from Pleiades Rational Polynomial Coefficients to ground control points. Primary images appear to be referenced within ~15 m over flat areas where parallax is minimal while derived DSMs and associated orthorectified images show a much improved referencing within ~5 m of GCPs. In order to assess the adequacy of Pleiades DSMs for tectonic geomorphology, we present examples from case studies along the Trougout normal fault (Morocco), the Hovd strike-slip fault (Mongolia), the Denali strike-slip fault (USA and Canada) and the Main Frontal Thrust (Bhutan). In addition to proposing a variety of tectonic contexts, these examples cover a wide range of climatic conditions (semi-arid, arctic and tropical), vegetation covers (bare earth, sparse Mediterranean, homogeneous arctic pine, varied tropical forest), lithological natures and related erosion rates. The capacity of derived DSMs is demonstrated to characterize geomorphic markers of active deformation such as marine and alluvial terraces

IMAGES: An interactive image processing system

NASA Technical Reports Server (NTRS)

Jensen, J. R.

1981-01-01

The IMAGES interactive image processing system was created specifically for undergraduate remote sensing education in geography. The system is interactive, relatively inexpensive to operate, almost hardware independent, and responsive to numerous users at one time in a time-sharing mode. Most important, it provides a medium whereby theoretical remote sensing principles discussed in lecture may be reinforced in laboratory as students perform computer-assisted image processing. In addition to its use in academic and short course environments, the system has also been used extensively to conduct basic image processing research. The flow of information through the system is discussed including an overview of the programs.

Anthropomorphic breast phantoms for preclinical imaging evaluation with transmission or emission imaging

NASA Astrophysics Data System (ADS)

Tornai, Martin P.; McKinley, Randolph L.; Bryzmialkiewicz, Caryl N.; Cutler, Spencer J.; Crotty, Dominic J.

2005-04-01

With the development of several classes of dedicated emission and transmission imaging technologies utilizing ionizing radiation for improved breast cancer detection and in vivo characterization, it is extremely useful to have available anthropomorphic breast phantoms in a variety of shapes, sizes and malleability prior to clinical imaging. These anthropomorphic phantoms can be used to evaluate the implemented imaging approaches given a known quantity, the phantom, and to evaluate the variability of the measurement due to the imaging system chain. Thus, we have developed a set of fillable and incompressible breast phantoms ranging in volume from 240 to 1730mL with nipple-to-chest distances from 3.8 to 12cm. These phantoms are mountable and exchangeable on either a uniform chest plate or anthropomorphic torso phantom containing tissue equivalent bones and surface tissue. Another fillable ~700mL breast phantom with solid anterior chest plate is intentionally compressible, and can be used for direct comparisons between standard planar imaging approaches using mild-to-severe compression, partially compressed tomosynthesis, and uncompressed computed mammotomography applications. These phantoms can be filled with various fluids (water and oil based liquids) to vary the fatty tissue background composition. Shaped cellulose sponges with two cell densities are fabricated and can be added to the breasts to simulate connective tissue. Additionally, microcalcifications can be simulated by peppering slits in the sponges with oyster shell fragments. These phantoms have a utility in helping to evaluate clinical imaging paradigms with known input object parameters using basic imaging characterization, in an effort to further evaluate contemporary and next generation imaging tools. They may additionally provide a means to collect known data samples for task based optimization studies.

JPEG2000 Image Compression on Solar EUV Images

NASA Astrophysics Data System (ADS)

Fischer, Catherine E.; Müller, Daniel; De Moortel, Ineke

2017-01-01

For future solar missions as well as ground-based telescopes, efficient ways to return and process data have become increasingly important. Solar Orbiter, which is the next ESA/NASA mission to explore the Sun and the heliosphere, is a deep-space mission, which implies a limited telemetry rate that makes efficient onboard data compression a necessity to achieve the mission science goals. Missions like the Solar Dynamics Observatory (SDO) and future ground-based telescopes such as the Daniel K. Inouye Solar Telescope, on the other hand, face the challenge of making petabyte-sized solar data archives accessible to the solar community. New image compression standards address these challenges by implementing efficient and flexible compression algorithms that can be tailored to user requirements. We analyse solar images from the Atmospheric Imaging Assembly (AIA) instrument onboard SDO to study the effect of lossy JPEG2000 (from the Joint Photographic Experts Group 2000) image compression at different bitrates. To assess the quality of compressed images, we use the mean structural similarity (MSSIM) index as well as the widely used peak signal-to-noise ratio (PSNR) as metrics and compare the two in the context of solar EUV images. In addition, we perform tests to validate the scientific use of the lossily compressed images by analysing examples of an on-disc and off-limb coronal-loop oscillation time-series observed by AIA/SDO.

ACTIM: an EDA initiated study on spectral active imaging

NASA Astrophysics Data System (ADS)

Steinvall, O.; Renhorn, I.; Ahlberg, J.; Larsson, H.; Letalick, D.; Repasi, E.; Lutzmann, P.; Anstett, G.; Hamoir, D.; Hespel, L.; Boucher, Y.

2010-10-01

This paper will describe ongoing work from an EDA initiated study on Active Imaging with emphasis of using multi or broadband spectral lasers and receivers. Present laser based imaging and mapping systems are mostly based on a fixed frequency lasers. On the other hand great progress has recently occurred in passive multi- and hyperspectral imaging with applications ranging from environmental monitoring and geology to mapping, military surveillance, and reconnaissance. Data bases on spectral signatures allow the possibility to discriminate between different materials in the scene. Present multi- and hyperspectral sensors mainly operate in the visible and short wavelength region (0.4-2.5 μm) and rely on the solar radiation giving shortcoming due to shadows, clouds, illumination angles and lack of night operation. Active spectral imaging however will largely overcome these difficulties by a complete control of the illumination. Active illumination enables spectral night and low-light operation beside a robust way of obtaining polarization and high resolution 2D/3D information. Recent development of broadband lasers and advanced imaging 3D focal plane arrays has led to new opportunities for advanced spectral and polarization imaging with high range resolution. Fusing the knowledge of ladar and passive spectral imaging will result in new capabilities in the field of EO-sensing to be shown in the study. We will present an overview of technology, systems and applications for active spectral imaging and propose future activities in connection with some prioritized applications.

Landsat image data quality studies

NASA Technical Reports Server (NTRS)

Schueler, C. F.; Salomonson, V. V.

1985-01-01

Preliminary results of the Landsat-4 Image Data Quality Analysis (LIDQA) program to characterize the data obtained using the Thematic Mapper (TM) instrument on board the Landsat-4 and Landsat-5 satellites are reported. TM design specifications were compared to the obtained data with respect to four criteria, including spatial resolution; geometric fidelity; information content; and image relativity to Multispectral Scanner (MSS) data. The overall performance of the TM was rated excellent despite minor instabilities and radiometric anomalies in the data. Spatial performance of the TM exceeded design specifications in terms of both image sharpness and geometric accuracy, and the image utility of the TM data was at least twice as high as MSS data. The separability of alfalfa and sugar beet fields in a TM image is demonstrated.

Fluorescence Imaging Study of Transition in Underexpanded Free Jets

NASA Technical Reports Server (NTRS)

Wilkes, Jennifer A.; Danehy, Paul M.; Nowak, Robert J.

2005-01-01

Planar laser-induced fluorescence (PLIF) is demonstrated to be a valuable tool for studying the onset of transition to turbulence. For this study, we have used PLIF of nitric oxide (NO) to image underexpanded axisymmetric free jets issuing into a low-pressure chamber through a smooth converging nozzle with a sonic orifice. Flows were studied over a range of Reynolds numbers and nozzle-exit-to-ambient pressure ratios with the aim of empirically determining criteria governing the onset of turbulence. We have developed an image processing technique, involving calculation of the standard deviation of the intensity in PLIF images, in order to aid in the identification of turbulence. We have used the resulting images to identify laminar, transitional and turbulent flow regimes. Jet scaling parameters were used to define a rescaled Reynolds number that incorporates the influence of a varying pressure ratio. An empirical correlation was found between transition length and this rescaled Reynolds number for highly underexpanded jets.

What Images Reveal: a Comparative Study of Science Images between Australian and Taiwanese Junior High School Textbooks

NASA Astrophysics Data System (ADS)

Ge, Yun-Ping; Unsworth, Len; Wang, Kuo-Hua; Chang, Huey-Por

2017-07-01

From a social semiotic perspective, image designs in science textbooks are inevitably influenced by the sociocultural context in which the books are produced. The learning environments of Australia and Taiwan vary greatly. Drawing on social semiotics and cognitive science, this study compares classificational images in Australian and Taiwanese junior high school science textbooks. Classificational images are important kinds of images, which can represent taxonomic relations among objects as reported by Kress and van Leeuwen (Reading images: the grammar of visual design, 2006). An analysis of the images from sample chapters in Australian and Taiwanese high school science textbooks showed that the majority of the Taiwanese images are covert taxonomies, which represent hierarchical relations implicitly. In contrast, Australian classificational images included diversified designs, but particularly types with a tree structure which depicted overt taxonomies, explicitly representing hierarchical super-ordinate and subordinate relations. Many of the Taiwanese images are reminiscent of the specimen images in eighteenth century science texts representing "what truly is", while more Australian images emphasize structural objectivity. Moreover, Australian images support cognitive functions which facilitate reading comprehension. The relationships between image designs and learning environments are discussed and implications for textbook research and design are addressed.

Failed heart rate control with oral metoprolol prior to coronary CT angiography: effect of additional intravenous metoprolol on heart rate, image quality and radiation dose.

PubMed

Jiménez-Juan, Laura; Nguyen, Elsie T; Wintersperger, Bernd J; Moshonov, Hadas; Crean, Andrew M; Deva, Djeven P; Paul, Narinder S; Torres, Felipe S

2013-01-01

The purpose of this study was to evaluate the effect of intravenous (i.v.) metoprolol after a suboptimal heart rate (HR) response to oral metoprolol (75-150 mg) on HR control, image quality (IQ) and radiation dose during coronary CTA using 320-MDCT. Fifty-three consecutive patients who failed to achieve a target HR of < 60 bpm after an oral dose of metoprolol and required supplementary i.v. metoprolol (5-20 mg) prior to coronary CTA were evaluated. Patients with HR < 60 bpm during image acquisition were defined as responders (R) and those with HR ≥ 60 bpm as non-responders (NR). Two observers assessed IQ using a 3-point scale (1-2, diagnostic and 3, non-diagnostic). Effective dose (ED) was estimated using dose-length product and a 0.014 mSV/mGy.cm conversion factor. Baseline characteristics and HR on arrival were similar in the two groups. 58% of patients didn't achieve the target HR after receiving i.v. metoprolol (NR). R had a significantly higher HR reduction after oral (mean HR 63.9 ± 4.5 bpm vs. 69.6 ± 5.6 bpm) (p < 0.005) and i.v. (mean HR 55.4 ± 3.9 bpm vs. 67.4 ± 5.3 bpm) (p < 0.005) doses of metoprolol. Studies from NR showed a significantly higher ED in comparison to R (8.0 ± 2.9 vs. 6.1 ± 2.2 mSv) (p = 0.016) and a significantly higher proportion of non-diagnostic coronary segments (9.2 vs. 2.5%) (p < 0.001). 58% of patients who do not achieve a HR of <60 bpm prior to coronary CTA with oral fail to respond to additional i.v. metoprolol and have studies with higher radiation dose and worse image quality.

Abnormal Corpus Callosum Connectivity, Socio-Communicative Deficits, and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study

ERIC Educational Resources Information Center

Hanaie, Ryuzo; Mohri, Ikuko; Kagitani-Shimono, Kuriko; Tachibana, Masaya; Matsuzaki, Junko; Watanabe, Yoshiyuki; Fujita, Norihiko; Taniike, Masako

2014-01-01

In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore…

Dynamic Liver Magnetic Resonance Imaging in Free-Breathing: Feasibility of a Cartesian T1-Weighted Acquisition Technique With Compressed Sensing and Additional Self-Navigation Signal for Hard-Gated and Motion-Resolved Reconstruction.

PubMed

Kaltenbach, Benjamin; Bucher, Andreas M; Wichmann, Julian L; Nickel, Dominik; Polkowski, Christoph; Hammerstingl, Renate; Vogl, Thomas J; Bodelle, Boris

2017-11-01

The aim of this study was to assess the feasibility of a free-breathing dynamic liver imaging technique using a prototype Cartesian T1-weighted volumetric interpolated breathhold examination (VIBE) sequence with compressed sensing and simultaneous acquisition of a navigation signal for hard-gated and motion state-resolved reconstruction. A total of 43 consecutive oncologic patients (mean age, 66 ± 11 years; 44% female) underwent free-breathing dynamic liver imaging for the evaluation of liver metastases from colorectal cancer using a prototype Cartesian VIBE sequence (field of view, 380 × 345 mm; image matrix, 320 × 218; echo time/repetition time, 1.8/3.76 milliseconds; flip angle, 10 degrees; slice thickness, 3.0 mm; acquisition time, 188 seconds) with continuous data sampling and additionally acquired self-navigation signal. Data were iteratively reconstructed using 2 different approaches: first, a hard-gated reconstruction only using data associated to the dominating motion state (CS VIBE, Compressed Sensing VIBE), and second, a motion-resolved reconstruction with 6 different motion states as additional image dimension (XD VIBE, eXtended dimension VIBE). Continuous acquired data were grouped in 16 subsequent time increments with 11.57 seconds each to resolve arterial and venous contrast phases. For image quality assessment, both CS VIBE and XD VIBE were compared with the patient's last staging dynamic liver magnetic resonance imaging including a breathhold (BH) VIBE as reference standard 4.5 ± 1.2 months before. Representative quality parameters including respiratory artifacts were evaluated for arterial and venous phase images independently, retrospectively and blindly by 3 experienced radiologists, with higher scores indicating better examination quality. To assess diagnostic accuracy, same readers evaluated the presence of metastatic lesions for XD VIBE and CS VIBE compared with reference BH examination in a second session. Compared with CS VIBE, XD VIBE

Brain lesions in septic shock: a magnetic resonance imaging study.

PubMed

Sharshar, Tarek; Carlier, Robert; Bernard, Francis; Guidoux, Céline; Brouland, Jean-Philippe; Nardi, Olivier; de la Grandmaison, Geoffroy Lorin; Aboab, Jérôme; Gray, Françoise; Menon, David; Annane, Djillali

2007-05-01

Understanding of sepsis-induced brain dysfunction remains poor, and relies mainly on data from animals or post-mortem studies in patients. The current study provided findings from magnetic resonance imaging of the brain in septic shock. Nine patients with septic shock and brain dysfunction [7 women, median age 63 years (interquartile range 61-79 years), SAPS II: 48 (44-56), SOFA: 8 (6-10)] underwent brain magnetic resonance imaging including gradient echo T1-weighted, fluid-attenuated inversion recovery (FLAIR), T2-weighted and diffusion isotropic images, and mapping of apparent diffusion coefficient. Brain imaging was normal in two patients, showed multiple ischaemic strokes in two patients, and in the remaining patients showed white matter lesions at the level of the centrum semiovale, predominating around Virchow-Robin spaces, ranging from small multiple areas to diffuse lesions, and characterised by hyperintensity on FLAIR images. The main lesions were also characterised by reduced signal on diffusion isotropic images and increased apparent diffusion coefficient. The lesions of the white matter worsened with increasing duration of shock and were correlated with Glasgow Outcome Score. This preliminary study showed that sepsis-induced brain lesions can be documented by magnetic resonance imaging. These lesions predominated in the white matter, suggesting increased blood-brain barrier permeability, and were associated with poor outcome.

Body image and self-esteem in disorders of sex development: A European multicenter study.

PubMed

van de Grift, Tim C; Cohen-Kettenis, Peggy T; de Vries, Annelou L C; Kreukels, Baudewijntje P C

2018-04-01

Disorders/differences of sex development (DSD) refer to congenital conditions with atypical sex development and are associated with psychosexual issues. The aim of this study was to assess body image and self-esteem across the DSD spectrum and to study the impact of diagnosis and mediating characteristics. Data collection was part of dsd-LIFE, a cross-sectional study conducted by 14 European expert clinics on wellbeing and health care evaluation of adults diagnosed with DSD. Main outcome measures in the present analyses were the Body Image Scale and Rosenberg Self-Esteem Scale. Additional data were obtained on treatments, openness, body embarrassment, sexual satisfaction, anxiety, and depression. The participating sample (n = 1,040) included 226 classified as Congenital Adrenal Hyperplasia, 225 as Klinefelter Syndrome, 322 as Turner Syndrome, and 267 as conditions with 46,XY karyotype. Many participants had received hormonal and surgical treatments. Participants scored lower on body image and self-esteem compared to control values, whereas each diagnosis showed different areas of concern. Limited openness, body embarrassment, and sexual issues were frequently reported. Overall body satisfaction was associated with BMI, hormone use, openness, body embarrassment, anxiety, and depression; genital satisfaction with age at diagnosis, openness, sexual satisfaction, and body embarrassment. Body embarrassment, anxiety, and depression predicted lower self-esteem. While each DSD showed specific issues related to body image and self-esteem, our findings indicate that the related factors were similar across the conditions. Clinical care on this subject could be improved by giving specific attention to factors like openness, body embarrassment, sexuality, anxiety, and depression. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Imaging Surveillance After Primary Breast Cancer Treatment

PubMed Central

Lam, Diana L.; Houssami, Nehmat; Lee, Janie M.

2017-01-01

OBJECTIVE Current clinical guidelines are consistent in supporting annual mammography for women after treatment of primary breast cancer. Surveillance imaging beyond standard digital mammography, including digital breast tomosynthesis (DBT), breast ultrasound, and MRI, may improve outcomes. This article reviews the evidence on the performance and effectiveness of breast imaging modalities available for surveillance after treatment of sporadic unilateral primary breast cancer and identifies additional factors to be considered when selecting an imaging surveillance regimen. CONCLUSION Evidence review supports the use of mammography for surveillance after primary breast cancer treatment. Variability exists in guideline recommendations for surveillance initiation, interval, and cessation. DBT offers the most promise as a potential modality to replace standard digital mammography as a front-line surveillance test; a single published study to date has shown a significant decrease in recall rates compared with standard digital mammography alone. Most guidelines do not support the use of whole-breast ultrasound in breast cancer surveillance, and further studies are needed to define the characteristics of women who may benefit from MRI surveillance. The emerging evidence about surveillance imaging outcomes suggests that additional factors, including patient and imaging characteristics, tumor biology and gene expression profile, and choice of treatment, warrant consideration in selecting personalized posttreatment imaging surveillance regimens. PMID:28075622

Media additives to promote spheroid circularity and compactness in hanging drop platform.

PubMed

Leung, Brendan M; Lesher-Perez, Sasha Cai; Matsuoka, Toshiki; Moraes, Christopher; Takayama, Shuichi

2015-02-01

Three-dimensional spheroid cultures have become increasingly popular as drug screening platforms, especially with the advent of different high throughput spheroid forming technologies. However, comparing drug efficacy across different cell types in spheroid culture can be difficult due to variations in spheroid morphologies and transport characteristics. Improving the reproducibility of compact, circular spheroids contributes to standardizing and increasing the fidelity of the desired gradient profiles in these drug screening three-dimensional tissue cultures. In this study we discuss the role that circularity and compaction has on spheroids, and demonstrate the impact methylcellulose (MethoCel) and collagen additives in the culture media can contribute to more compact and circular spheroid morphology. We demonstrate that improved spheroid formation is not a simple function of increased viscosity of the different macromolecule additives, suggesting that other macromolecular characteristics contribute to improved spheroid formation. Of the various macromolecular additives tested for hanging drop culture, MethoCel provided the most desirable spheroid formation. Additionally, the higher viscosity of MethoCel-containing media improved the ease of imaging of cellular spheroids within hanging drop cultures by reducing motion-induced image blur.

Kaolinite flocculation induced by smectite addition - a transmission X-ray microscopic study.

PubMed

Zbik, Marek S; Song, Yen-Fang; Frost, Ray L

2010-09-01

The influence of smectite addition on kaolinite suspensions in water was investigated by transmission X-ray microscopy (TXM) and Scanning Electron Microscopy (SEM). Sedimentation test screening was also conducted. Micrographs were processed by the STatistic IMage Analysing (STIMAN) program and structural parameters were calculated. From the results of the sedimentation tests important influences of small smectite additions to about 3wt.% on kaolinite suspension flocculation has been found. In order to determine the reason for this smectite impact on kaolinite suspension, macroscopic behaviour micro-structural examination using Transmission X-ray Microscope (TXM) and SEM has been undertaken. TXM & SEM micrographs of freeze-dried kaolinite-smectite suspensions with up to 20% smectite showed a high degree of orientation of the fabric made of highly oriented particles and greatest density when 3wt.% of smectite was added to the 10wt.% dense kaolinite suspension. In contrast, suspensions containing pure kaolinite do not show such platelet mutual orientation but homogenous network of randomly oriented kaolinite platelets. This suggests that in kaolinite-smectite suspensions, smectite forms highly oriented basic framework into which kaolinite platelets may bond in face to face preferential contacts strengthening structure and allowing them to show plastic behaviour which is cause of platelets orientation. Copyright 2010 Elsevier Inc. All rights reserved.

Concrete thawing studied by single-point ramped imaging.

PubMed

Prado, P J; Balcom, B J; Beyea, S D; Armstrong, R L; Bremner, T W

1997-12-01

A series of two-dimensional images of proton distribution in a hardened concrete sample has been obtained during the thawing process (from -50 degrees C up to 11 degrees C). The SPRITE sequence is optimal for this study given the characteristic short relaxation times of water in this porous media (T2* < 200 micros and T1 < 3.6 ms). The relaxation parameters of the sample were determined in order to optimize the time efficiency of the sequence, permitting a 4-scan 64 x 64 acquisition in under 3 min. The image acquisition is fast on the time scale of the temperature evolution of the specimen. The frozen water distribution is quantified through a position based study of the image contrast. A multiple point acquisition method is presented and the signal sensitivity improvement is discussed.

Tracking iron in multiple sclerosis: a combined imaging and histopathological study at 7 Tesla

PubMed Central

Hametner, Simon; Yao, Bing; van Gelderen, Peter; Merkle, Hellmut; Cantor, Fredric K.; Lassmann, Hans; Duyn, Jeff H.

2011-01-01

sources included oligodendrocytes in normal-appearing white matter and activated macrophages/microglia at the edges of white matter lesions. Additionally, in white matter lesions, iron precipitation in aggregates typical of microbleeds was shown by the Perl's staining. Our combined imaging and pathological study shows that multi-gradient echo magnetic resonance imaging is a sensitive technique for the identification of iron in the brain tissue of patients with multiple sclerosis. However, magnetic resonance imaging-identified iron does not necessarily reflect pathology and may also be seen in apparently normal tissue. Iron identification by multi-gradient echo magnetic resonance imaging in diseased tissues can shed light on the pathological processes when coupled with topographical information and patient disease history. PMID:22171355

Self-Image and Physical Education--A Phenomenological Study

ERIC Educational Resources Information Center

Perrin-Wallqvist, Renee; Carlsson, Eva Segolsson

2011-01-01

In this study our aim was to investigate (a) how the awareness of one's self-image reveals itself as a phenomenon, and (b) if self-image is influenced by physical education in a social context with teachers and pupils. Six pupils, aged 15 and 16 years, attending compulsory school were interviewed with the use of an empirical phenomenological…

Three-dimensional image authentication scheme using sparse phase information in double random phase encoded integral imaging.

PubMed

Yi, Faliu; Jeoung, Yousun; Moon, Inkyu

2017-05-20

In recent years, many studies have focused on authentication of two-dimensional (2D) images using double random phase encryption techniques. However, there has been little research on three-dimensional (3D) imaging systems, such as integral imaging, for 3D image authentication. We propose a 3D image authentication scheme based on a double random phase integral imaging method. All of the 2D elemental images captured through integral imaging are encrypted with a double random phase encoding algorithm and only partial phase information is reserved. All the amplitude and other miscellaneous phase information in the encrypted elemental images is discarded. Nevertheless, we demonstrate that 3D images from integral imaging can be authenticated at different depths using a nonlinear correlation method. The proposed 3D image authentication algorithm can provide enhanced information security because the decrypted 2D elemental images from the sparse phase cannot be easily observed by the naked eye. Additionally, using sparse phase images without any amplitude information can greatly reduce data storage costs and aid in image compression and data transmission.

A comparative study for chest radiograph image retrieval using binary texture and deep learning classification.

PubMed

Anavi, Yaron; Kogan, Ilya; Gelbart, Elad; Geva, Ofer; Greenspan, Hayit

2015-08-01

In this work various approaches are investigated for X-ray image retrieval and specifically chest pathology retrieval. Given a query image taken from a data set of 443 images, the objective is to rank images according to similarity. Different features, including binary features, texture features, and deep learning (CNN) features are examined. In addition, two approaches are investigated for the retrieval task. One approach is based on the distance of image descriptors using the above features (hereon termed the "descriptor"-based approach); the second approach ("classification"-based approach) is based on a probability descriptor, generated by a pair-wise classification of each two classes (pathologies) and their decision values using an SVM classifier. Best results are achieved using deep learning features in a classification scheme.

Charge-coupled device image sensor study

NASA Technical Reports Server (NTRS)

1973-01-01

The design specifications and predicted performance characteristics of a Charge-Coupled Device Area Imager and a Charge-Coupled Device Linear Imager are presented. The Imagers recommended are intended for use in space-borne imaging systems and therefore would meet the requirements for the intended application. A unique overlapping metal electrode structure and a buried channel structure are described. Reasons for the particular imager designs are discussed.

Diffusion Tensor Imaging Studies on Arcuate Fasciculus in Stroke Patients: A Review

PubMed Central

Jang, Sung Ho

2013-01-01

Aphasia is one of the most common and devastating sequelae of stroke. The arcuate fasciculus (AF), an important neural tract for language function, connects Broca’s and Wernicke’s areas. In this review article, previous diffusion tensor imaging (DTI) studies on the AF in stroke patients were reviewed with regard to the usefulness for diagnosis (seven studies), prediction of prognosis (two studies), and recovery of aphasia (three studies). Although scant studies on this topic have been conducted in stroke patients, DTI for the AF appears to provide useful information on the presence or severity of injury of the AF, prognosis prediction of aphasia, and recovery mechanisms of aphasia in stroke patients. Therefore, further DTI studies on these topics should be encouraged, especially studies on prognosis prediction and recovery mechanisms of aphasia. In addition, research on other neural tracts known to be involved in aphasia as well as the AF in both hemispheres should be encouraged. PMID:24198780

Breast Imaging Second Opinions Impact Surgical Management.

PubMed

Spivey, Tara Lynn; Carlson, Kjirsten Ayn; Janssen, Imke; Witt, Thomas R; Jokich, Peter; Madrigrano, Andrea

2015-07-01

Breast surgeons often see women for second opinions for abnormalities found on breast imaging. For second opinions, these images are submitted for review and interpretation by dedicated breast imagers. This study evaluated the conformity of results among interpretation of imaging submitted from outside hospitals both from tertiary care centers, as well as community programs, in an attempt to evaluate the utility of this practice for the sake of clinical management and resource utilization. A retrospective chart review was conducted on all breast patients that submitted outside imaging films for the years 2011 to 2013 at Rush University Medical Center (RUMC). The radiologic diagnosis and each patient's proposed management plan was collected and evaluated for concordance between the outside institutions and RUMC. A total of 380 patients who presented for second opinions with an interpretation of outside exams were evaluated. In 47.4 % [95 % confidence interval (CI) 42.4-52.4] of cases there was distinct variance in radiologic impression. For 53.5 % (95 % CI 48.4-58.5) of patients, there was a change in recommended management plan, which included recommendations for either additional imaging or need for additional biopsy. In total, this changed the overall surgical management in 27.1 % (95 % CI 22.8-31.9) of cases. In six patients, the reinterpretation of outside imaging detected new malignancies not previously identified. Overall, 83.7 % (95 % CI 79.7-87.1) of patients who submitted imaging from outside institutions chose to complete the remainder of their treatment at RUMC. The practice of second opinion review changed overall definitive management at our specialty center in more than one in four cases. In addition, the review identified six previously unrecognized malignancies. Given this data, the practice of second opinions and interpretation of outside exams should continue despite the additional resources required.

An interactive histology image-barcode manual for a videodisc image library.

PubMed

Ogilvie, R W

1995-01-01

of class. There is a need for resources for additional study outside of the institutional setting, for students to have and interact with to reinforce the learning experience in the teaching laboratory. A hard copy manual was created and is being used in our course; it incorporates photos captured from the videodisc. The images displayed in the manual are chosen to give the student one example of each histological component. Additional labeling is added to the images, and each image is accompanied by a bar code that may be used at a videodisc player with a bar code reader to retrieve the same color image from the disc displayed in larger format on a TV monitor. Each topic in the manual is accompanied by learning objectives and a statement of clinical relevance. Following the presentation of the images in each section of the manual, the students are encouraged to practice by viewing multiple examples of each structural component presented in the lesson. They can do this by using the bar-coded catalog supplied with each disc. The presentation of each topic concludes with a quiz composed of questions about images that the student can retrieve from the videodisc using barcodes in the text of the manual. Some of the images on the quiz are printed in miniature in the manual to provide the student with an opportunity for personal review at home when hardware to obtain and display images from a video disc is not available. This manual provides an answer to the dilemma faced by the learner when access to hardware is not available; reinforcement is therefore facilitated outside the teaching laboratory. This allows learning to continue outside of the classroom, using the same materials. (abstract truncated)

Studying depression using imaging and machine learning methods.

PubMed

Patel, Meenal J; Khalaf, Alexander; Aizenstein, Howard J

2016-01-01

Depression is a complex clinical entity that can pose challenges for clinicians regarding both accurate diagnosis and effective timely treatment. These challenges have prompted the development of multiple machine learning methods to help improve the management of this disease. These methods utilize anatomical and physiological data acquired from neuroimaging to create models that can identify depressed patients vs. non-depressed patients and predict treatment outcomes. This article (1) presents a background on depression, imaging, and machine learning methodologies; (2) reviews methodologies of past studies that have used imaging and machine learning to study depression; and (3) suggests directions for future depression-related studies.

Real-time phase-contrast x-ray imaging: a new technique for the study of animal form and function

PubMed Central

Socha, John J; Westneat, Mark W; Harrison, Jon F; Waters, James S; Lee, Wah-Keat

2007-01-01

Background Despite advances in imaging techniques, real-time visualization of the structure and dynamics of tissues and organs inside small living animals has remained elusive. Recently, we have been using synchrotron x-rays to visualize the internal anatomy of millimeter-sized opaque, living animals. This technique takes advantage of partially-coherent x-rays and diffraction to enable clear visualization of internal soft tissue not viewable via conventional absorption radiography. However, because higher quality images require greater x-ray fluxes, there exists an inherent tradeoff between image quality and tissue damage. Results We evaluated the tradeoff between image quality and harm to the animal by determining the impact of targeted synchrotron x-rays on insect physiology, behavior and survival. Using 25 keV x-rays at a flux density of 80 μW/mm-2, high quality video-rate images can be obtained without major detrimental effects on the insects for multiple minutes, a duration sufficient for many physiological studies. At this setting, insects do not heat up. Additionally, we demonstrate the range of uses of synchrotron phase-contrast imaging by showing high-resolution images of internal anatomy and observations of labeled food movement during ingestion and digestion. Conclusion Synchrotron x-ray phase contrast imaging has the potential to revolutionize the study of physiology and internal biomechanics in small animals. This is the only generally applicable technique that has the necessary spatial and temporal resolutions, penetrating power, and sensitivity to soft tissue that is required to visualize the internal physiology of living animals on the scale from millimeters to microns. PMID:17331247

A study of human recognition rates for foveola-sized image patches selected from initial and final fixations on calibrated natural images

NASA Astrophysics Data System (ADS)

van der Linde, Ian; Rajashekar, Umesh; Cormack, Lawrence K.; Bovik, Alan C.

2005-03-01

Recent years have seen a resurgent interest in eye movements during natural scene viewing. Aspects of eye movements that are driven by low-level image properties are of particular interest due to their applicability to biologically motivated artificial vision and surveillance systems. In this paper, we report an experiment in which we recorded observers" eye movements while they viewed calibrated greyscale images of natural scenes. Immediately after viewing each image, observers were shown a test patch and asked to indicate if they thought it was part of the image they had just seen. The test patch was either randomly selected from a different image from the same database or, unbeknownst to the observer, selected from either the first or last location fixated on the image just viewed. We find that several low-level image properties differed significantly relative to the observers" ability to successfully designate each patch. We also find that the differences between patch statistics for first and last fixations are small compared to the differences between hit and miss responses. The goal of the paper was to, in a non-cognitive natural setting, measure the image properties that facilitate visual memory, additionally observing the role that temporal location (first or last fixation) of the test patch played. We propose that a memorability map of a complex natural scene may be constructed to represent the low-level memorability of local regions in a similar fashion to the familiar saliency map, which records bottom-up fixation attractors.

Metabolic Imaging in Parkinson Disease.

PubMed

Meles, Sanne K; Teune, Laura K; de Jong, Bauke M; Dierckx, Rudi A; Leenders, Klaus L

2017-01-01

This review focuses on recent human 18 F-FDG PET studies in Parkinson disease. First, an overview is given of the current analytic approaches to metabolic brain imaging data. Next, we discuss how 18 F-FDG PET studies have advanced understanding of the relation between distinct brain regions and associated symptoms in Parkinson disease, including cognitive decline. In addition, the value of 18 F-FDG PET studies in differential diagnosis, identifying prodromal patients, and the evaluation of treatment effects are reviewed. Finally, anticipated developments in the field are addressed. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

Imaging angiogenesis.

PubMed

Charnley, Natalie; Donaldson, Stephanie; Price, Pat

2009-01-01

There is a need for direct imaging of effects on tumor vasculature in assessment of response to antiangiogenic drugs and vascular disrupting agents. Imaging tumor vasculature depends on differences in permeability of vasculature of tumor and normal tissue, which cause changes in penetration of contrast agents. Angiogenesis imaging may be defined in terms of measurement of tumor perfusion and direct imaging of the molecules involved in angiogenesis. In addition, assessment of tumor hypoxia will give an indication of tumor vasculature. The range of imaging techniques available for these processes includes positron emission tomography (PET), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), perfusion computed tomography (CT), and ultrasound (US).

Multi-site study of additive genetic effects on fractional anisotropy of cerebral white matter: Comparing meta and megaanalytical approaches for data pooling.

PubMed

Kochunov, Peter; Jahanshad, Neda; Sprooten, Emma; Nichols, Thomas E; Mandl, René C; Almasy, Laura; Booth, Tom; Brouwer, Rachel M; Curran, Joanne E; de Zubicaray, Greig I; Dimitrova, Rali; Duggirala, Ravi; Fox, Peter T; Hong, L Elliot; Landman, Bennett A; Lemaitre, Hervé; Lopez, Lorna M; Martin, Nicholas G; McMahon, Katie L; Mitchell, Braxton D; Olvera, Rene L; Peterson, Charles P; Starr, John M; Sussmann, Jessika E; Toga, Arthur W; Wardlaw, Joanna M; Wright, Margaret J; Wright, Susan N; Bastin, Mark E; McIntosh, Andrew M; Boomsma, Dorret I; Kahn, René S; den Braber, Anouk; de Geus, Eco J C; Deary, Ian J; Hulshoff Pol, Hilleke E; Williamson, Douglas E; Blangero, John; van 't Ent, Dennis; Thompson, Paul M; Glahn, David C

2014-07-15

Combining datasets across independent studies can boost statistical power by increasing the numbers of observations and can achieve more accurate estimates of effect sizes. This is especially important for genetic studies where a large number of observations are required to obtain sufficient power to detect and replicate genetic effects. There is a need to develop and evaluate methods for joint-analytical analyses of rich datasets collected in imaging genetics studies. The ENIGMA-DTI consortium is developing and evaluating approaches for obtaining pooled estimates of heritability through meta-and mega-genetic analytical approaches, to estimate the general additive genetic contributions to the intersubject variance in fractional anisotropy (FA) measured from diffusion tensor imaging (DTI). We used the ENIGMA-DTI data harmonization protocol for uniform processing of DTI data from multiple sites. We evaluated this protocol in five family-based cohorts providing data from a total of 2248 children and adults (ages: 9-85) collected with various imaging protocols. We used the imaging genetics analysis tool, SOLAR-Eclipse, to combine twin and family data from Dutch, Australian and Mexican-American cohorts into one large "mega-family". We showed that heritability estimates may vary from one cohort to another. We used two meta-analytical (the sample-size and standard-error weighted) approaches and a mega-genetic analysis to calculate heritability estimates across-population. We performed leave-one-out analysis of the joint estimates of heritability, removing a different cohort each time to understand the estimate variability. Overall, meta- and mega-genetic analyses of heritability produced robust estimates of heritability. Copyright © 2014 Elsevier Inc. All rights reserved.

Molecular imaging using light-absorbing imaging agents and a clinical optical breast imaging system--a phantom study.

PubMed

van de Ven, Stephanie M W Y; Mincu, Niculae; Brunette, Jean; Ma, Guobin; Khayat, Mario; Ikeda, Debra M; Gambhir, Sanjiv S

2011-04-01

The aim of the study was to determine the feasibility of using a clinical optical breast scanner with molecular imaging strategies based on modulating light transmission. Different concentrations of single-walled carbon nanotubes (SWNT; 0.8-20.0 nM) and black hole quencher-3 (BHQ-3; 2.0-32.0 µM) were studied in specifically designed phantoms (200-1,570 mm(3)) with a clinical optical breast scanner using four wavelengths. Each phantom was placed in the scanner tank filled with optical matching medium. Background scans were compared to absorption scans, and reproducibility was assessed. All SWNT phantoms were detected at four wavelengths, with best results at 684 nm. Higher concentrations (≥8.0 µM) were needed for BHQ-3 detection, with the largest contrast at 684 nm. The optical absorption signal was dependent on phantom size and concentration. Reproducibility was excellent (intraclass correlation 0.93-0.98). Nanomolar concentrations of SWNT and micromolar concentrations of BHQ-3 in phantoms were reproducibly detected, showing the potential of light absorbers, with appropriate targeting ligands, as molecular imaging agents for clinical optical breast imaging.

Automatic tracking of arbitrarily shaped implanted markers in kilovoltage projection images: A feasibility study

PubMed Central

Regmi, Rajesh; Lovelock, D. Michael; Hunt, Margie; Zhang, Pengpeng; Pham, Hai; Xiong, Jianping; Yorke, Ellen D.; Goodman, Karyn A.; Rimner, Andreas; Mostafavi, Hassan; Mageras, Gig S.

2014-01-01

Purpose: Certain types of commonly used fiducial markers take on irregular shapes upon implantation in soft tissue. This poses a challenge for methods that assume a predefined shape of markers when automatically tracking such markers in kilovoltage (kV) radiographs. The authors have developed a method of automatically tracking regularly and irregularly shaped markers using kV projection images and assessed its potential for detecting intrafractional target motion during rotational treatment. Methods: Template-based matching used a normalized cross-correlation with simplex minimization. Templates were created from computed tomography (CT) images for phantom studies and from end-expiration breath-hold planning CT for patient studies. The kV images were processed using a Sobel filter to enhance marker visibility. To correct for changes in intermarker relative positions between simulation and treatment that can introduce errors in automatic matching, marker offsets in three dimensions were manually determined from an approximately orthogonal pair of kV images. Two studies in anthropomorphic phantom were carried out, one using a gold cylindrical marker representing regular shape, another using a Visicoil marker representing irregular shape. Automatic matching of templates to cone beam CT (CBCT) projection images was performed to known marker positions in phantom. In patient data, automatic matching was compared to manual matching as an approximate ground truth. Positional discrepancy between automatic and manual matching of less than 2 mm was assumed as the criterion for successful tracking. Tracking success rates were examined in kV projection images from 22 CBCT scans of four pancreas, six gastroesophageal junction, and one lung cancer patients. Each patient had at least one irregularly shaped radiopaque marker implanted in or near the tumor. In addition, automatic tracking was tested in intrafraction kV images of three lung cancer patients with irregularly shaped

Automatic tracking of arbitrarily shaped implanted markers in kilovoltage projection images: A feasibility study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Regmi, Rajesh; Lovelock, D. Michael; Hunt, Margie

Purpose: Certain types of commonly used fiducial markers take on irregular shapes upon implantation in soft tissue. This poses a challenge for methods that assume a predefined shape of markers when automatically tracking such markers in kilovoltage (kV) radiographs. The authors have developed a method of automatically tracking regularly and irregularly shaped markers using kV projection images and assessed its potential for detecting intrafractional target motion during rotational treatment. Methods: Template-based matching used a normalized cross-correlation with simplex minimization. Templates were created from computed tomography (CT) images for phantom studies and from end-expiration breath-hold planning CT for patient studies. Themore » kV images were processed using a Sobel filter to enhance marker visibility. To correct for changes in intermarker relative positions between simulation and treatment that can introduce errors in automatic matching, marker offsets in three dimensions were manually determined from an approximately orthogonal pair of kV images. Two studies in anthropomorphic phantom were carried out, one using a gold cylindrical marker representing regular shape, another using a Visicoil marker representing irregular shape. Automatic matching of templates to cone beam CT (CBCT) projection images was performed to known marker positions in phantom. In patient data, automatic matching was compared to manual matching as an approximate ground truth. Positional discrepancy between automatic and manual matching of less than 2 mm was assumed as the criterion for successful tracking. Tracking success rates were examined in kV projection images from 22 CBCT scans of four pancreas, six gastroesophageal junction, and one lung cancer patients. Each patient had at least one irregularly shaped radiopaque marker implanted in or near the tumor. In addition, automatic tracking was tested in intrafraction kV images of three lung cancer patients with irregularly

Integration of prior CT into CBCT reconstruction for improved image quality via reconstruction of difference: first patient studies

NASA Astrophysics Data System (ADS)

Zhang, Hao; Gang, Grace J.; Lee, Junghoon; Wong, John; Stayman, J. Webster

2017-03-01

Purpose: There are many clinical situations where diagnostic CT is used for an initial diagnosis or treatment planning, followed by one or more CBCT scans that are part of an image-guided intervention. Because the high-quality diagnostic CT scan is a rich source of patient-specific anatomical knowledge, this provides an opportunity to incorporate the prior CT image into subsequent CBCT reconstruction for improved image quality. We propose a penalized-likelihood method called reconstruction of difference (RoD), to directly reconstruct differences between the CBCT scan and the CT prior. In this work, we demonstrate the efficacy of RoD with clinical patient datasets. Methods: We introduce a data processing workflow using the RoD framework to reconstruct anatomical changes between the prior CT and current CBCT. This workflow includes processing steps to account for non-anatomical differences between the two scans including 1) scatter correction for CBCT datasets due to increased scatter fractions in CBCT data; 2) histogram matching for attenuation variations between CT and CBCT; and 3) registration for different patient positioning. CBCT projection data and CT planning volumes for two radiotherapy patients - one abdominal study and one head-and-neck study - were investigated. Results: In comparisons between the proposed RoD framework and more traditional FDK and penalized-likelihood reconstructions, we find a significant improvement in image quality when prior CT information is incorporated into the reconstruction. RoD is able to provide additional low-contrast details while correctly incorporating actual physical changes in patient anatomy. Conclusions: The proposed framework provides an opportunity to either improve image quality or relax data fidelity constraints for CBCT imaging when prior CT studies of the same patient are available. Possible clinical targets include CBCT image-guided radiotherapy and CBCT image-guided surgeries.

Speckle noise reduction in ultrasound images using a discrete wavelet transform-based image fusion technique.

PubMed

Choi, Hyun Ho; Lee, Ju Hwan; Kim, Sung Min; Park, Sung Yun

2015-01-01

Here, the speckle noise in ultrasonic images is removed using an image fusion-based denoising method. To optimize the denoising performance, each discrete wavelet transform (DWT) and filtering technique was analyzed and compared. In addition, the performances were compared in order to derive the optimal input conditions. To evaluate the speckle noise removal performance, an image fusion algorithm was applied to the ultrasound images, and comparatively analyzed with the original image without the algorithm. As a result, applying DWT and filtering techniques caused information loss and noise characteristics, and did not represent the most significant noise reduction performance. Conversely, an image fusion method applying SRAD-original conditions preserved the key information in the original image, and the speckle noise was removed. Based on such characteristics, the input conditions of SRAD-original had the best denoising performance with the ultrasound images. From this study, the best denoising technique proposed based on the results was confirmed to have a high potential for clinical application.

Reproducibility study of whole-brain 1H spectroscopic imaging with automated quantification.

PubMed

Gu, Meng; Kim, Dong-Hyun; Mayer, Dirk; Sullivan, Edith V; Pfefferbaum, Adolf; Spielman, Daniel M

2008-09-01

A reproducibility study of proton MR spectroscopic imaging ((1)H-MRSI) of the human brain was conducted to evaluate the reliability of an automated 3D in vivo spectroscopic imaging acquisition and associated quantification algorithm. A PRESS-based pulse sequence was implemented using dualband spectral-spatial RF pulses designed to fully excite the singlet resonances of choline (Cho), creatine (Cre), and N-acetyl aspartate (NAA) while simultaneously suppressing water and lipids; 1% of the water signal was left to be used as a reference signal for robust data processing, and additional lipid suppression was obtained using adiabatic inversion recovery. Spiral k-space trajectories were used for fast spectral and spatial encoding yielding high-quality spectra from 1 cc voxels throughout the brain with a 13-min acquisition time. Data were acquired with an 8-channel phased-array coil and optimal signal-to-noise ratio (SNR) for the combined signals was achieved using a weighting based on the residual water signal. Automated quantification of the spectrum of each voxel was performed using LCModel. The complete study consisted of eight healthy adult subjects to assess intersubject variations and two subjects scanned six times each to assess intrasubject variations. The results demonstrate that reproducible whole-brain (1)H-MRSI data can be robustly obtained with the proposed methods.

Monte Carlo simulations in X-ray imaging

NASA Astrophysics Data System (ADS)

Giersch, Jürgen; Durst, Jürgen

2008-06-01

Monte Carlo simulations have become crucial tools in many fields of X-ray imaging. They help to understand the influence of physical effects such as absorption, scattering and fluorescence of photons in different detector materials on image quality parameters. They allow studying new imaging concepts like photon counting, energy weighting or material reconstruction. Additionally, they can be applied to the fields of nuclear medicine to define virtual setups studying new geometries or image reconstruction algorithms. Furthermore, an implementation of the propagation physics of electrons and photons allows studying the behavior of (novel) X-ray generation concepts. This versatility of Monte Carlo simulations is illustrated with some examples done by the Monte Carlo simulation ROSI. An overview of the structure of ROSI is given as an example of a modern, well-proven, object-oriented, parallel computing Monte Carlo simulation for X-ray imaging.

An fMRI study of magnitude comparison and exact addition in children.

PubMed

Meintjes, Ernesta M; Jacobson, Sandra W; Molteno, Christopher D; Gatenby, J Christopher; Warton, Christopher; Cannistraci, Christopher J; Gore, John C; Jacobson, Joseph L

2010-04-01

By contrast to the adult literature, in which a consistent parietofrontal network for number processing has been identified, the data from studies of number processing in children have been less consistent, probably due to differences in study design and control conditions. Number processing was examined using functional magnetic resonance imaging in 18 right-handed children (8-12 years) from the Cape Coloured community in Cape Town, South Africa, using Proximity Judgment and Exact Addition (EA) tasks. The findings were consistent with the hypothesis that, as in adults, the anterior horizontal intraparietal sulcus (HIPS) plays a major role in the representation and manipulation of quantity in children. The posterior medial frontal cortex, believed to be involved in performance monitoring in more complex arithmetic manipulations in adults, was extensively activated even for relatively simple symbolic number processing in the children. Other areas activated to a greater degree in the children included the left precentral sulcus, which may mediate number knowledge and, for EA, the head of the caudate nucleus, which is part of a fronto-subcortical circuit involved in the behavioral execution of sequences. Two regions that have been linked to number processing in adults - the angular gyrus and posterior superior parietal lobule - were not activated in the children. The data are consistent with the inference that although the functional specialization of the anterior HIPS may increase as symbolic number processing becomes increasingly automatic, this region and other elements of the parietofrontal network identified in adults are already reliably and robustly activated by middle childhood. Copyright 2010 Elsevier Inc. All rights reserved.

ImagingSIMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

2017-11-06

ImagingSIMS is an open source application for loading, processing, manipulating and visualizing secondary ion mass spectrometry (SIMS) data. At PNNL, a separate branch has been further developed to incorporate application specific features for dynamic SIMS data sets. These include loading CAMECA IMS-1280, NanoSIMS and modified IMS-4f raw data, creating isotopic ratio images and stitching together images from adjacent interrogation regions. In addition to other modifications of the parent open source version, this version is equipped with a point-by-point image registration tool to assist with streamlining the image fusion process.

Sparse image reconstruction for molecular imaging.

PubMed

Ting, Michael; Raich, Raviv; Hero, Alfred O

2009-06-01

The application that motivates this paper is molecular imaging at the atomic level. When discretized at subatomic distances, the volume is inherently sparse. Noiseless measurements from an imaging technology can be modeled by convolution of the image with the system point spread function (psf). Such is the case with magnetic resonance force microscopy (MRFM), an emerging technology where imaging of an individual tobacco mosaic virus was recently demonstrated with nanometer resolution. We also consider additive white Gaussian noise (AWGN) in the measurements. Many prior works of sparse estimators have focused on the case when H has low coherence; however, the system matrix H in our application is the convolution matrix for the system psf. A typical convolution matrix has high coherence. This paper, therefore, does not assume a low coherence H. A discrete-continuous form of the Laplacian and atom at zero (LAZE) p.d.f. used by Johnstone and Silverman is formulated, and two sparse estimators derived by maximizing the joint p.d.f. of the observation and image conditioned on the hyperparameters. A thresholding rule that generalizes the hard and soft thresholding rule appears in the course of the derivation. This so-called hybrid thresholding rule, when used in the iterative thresholding framework, gives rise to the hybrid estimator, a generalization of the lasso. Estimates of the hyperparameters for the lasso and hybrid estimator are obtained via Stein's unbiased risk estimate (SURE). A numerical study with a Gaussian psf and two sparse images shows that the hybrid estimator outperforms the lasso.

A case study on topology optimized design for additive manufacturing

NASA Astrophysics Data System (ADS)

Gebisa, A. W.; Lemu, H. G.

2017-12-01

Topology optimization is an optimization method that employs mathematical tools to optimize material distribution in a part to be designed. Earlier developments of topology optimization considered conventional manufacturing techniques that have limitations in producing complex geometries. This has hindered the topology optimization efforts not to fully be realized. With the emergence of additive manufacturing (AM) technologies, the technology that builds a part layer upon a layer directly from three dimensional (3D) model data of the part, however, producing complex shape geometry is no longer an issue. Realization of topology optimization through AM provides full design freedom for the design engineers. The article focuses on topologically optimized design approach for additive manufacturing with a case study on lightweight design of jet engine bracket. The study result shows that topology optimization is a powerful design technique to reduce the weight of a product while maintaining the design requirements if additive manufacturing is considered.

Study of the development of fetal baboon brain using magnetic resonance imaging at 3 Tesla

PubMed Central

Liu, Feng; Garland, Marianne; Duan, Yunsuo; Stark, Raymond I.; Xu, Dongrong; Dong, Zhengchao; Bansal, Ravi; Peterson, Bradley S.; Kangarlu, Alayar

2008-01-01

Direct observational data on the development of the brains of human and nonhuman primates is on remarkably scant, and most of our understanding of primate brain development is extrapolated from findings in rodent models. Magnetic resonance imaging (MRI) is a promising tool for the noninvasive, longitudinal study of the developing primate brain. We devised a protocol to scan pregnant baboons serially at 3 T for up to 3 h per session. Seven baboons were scanned 1–6 times, beginning as early as 56 days post-conceptional age, and as late as 185 days (term ~185 days). Successful scanning of the fetal baboon required careful animal preparation and anesthesia, in addition to optimization of the scanning protocol. We successfully acquired maps of relaxation times (T1 and T2) and high-resolution anatomical images of the brains of fetal baboons at multiple time points during the course of gestation. These images demonstrated the convergence of gray and white matter contrast near term, and furthermore demonstrated that the loss of contrast at that age is a consequence of the continuous change in relaxation times during fetal brain development. These data furthermore demonstrate that maps of relaxation times have clear advantages over the relaxation time weighted images for the tracking of the changes in brain structure during fetal development. This protocol for in utero MRI of fetal baboon brains will help to advance the use of nonhuman primate models to study fetal brain development longitudinally. PMID:18155925

Quantitative phase imaging of arthropods

PubMed Central

Sridharan, Shamira; Katz, Aron; Soto-Adames, Felipe; Popescu, Gabriel

2015-01-01

Abstract. Classification of arthropods is performed by characterization of fine features such as setae and cuticles. An unstained whole arthropod specimen mounted on a slide can be preserved for many decades, but is difficult to study since current methods require sample manipulation or tedious image processing. Spatial light interference microscopy (SLIM) is a quantitative phase imaging (QPI) technique that is an add-on module to a commercial phase contrast microscope. We use SLIM to image a whole organism springtail Ceratophysella denticulata mounted on a slide. This is the first time, to our knowledge, that an entire organism has been imaged using QPI. We also demonstrate the ability of SLIM to image fine structures in addition to providing quantitative data that cannot be obtained by traditional bright field microscopy. PMID:26334858

Earth analog image digitization of field, aerial, and lab experiment studies for Planetary Data System archiving.

NASA Astrophysics Data System (ADS)

Williams, D. A.; Nelson, D. M.

2017-12-01

A portion of the earth analog image archive at the Ronald Greeley Center for Planetary Studies (RGCPS)-the NASA Regional Planetary Information Facility at Arizona State University-is being digitized and will be added to the Planetary Data System (PDS) for public use. This will be a first addition of terrestrial data to the PDS specifically for comparative planetology studies. Digitization is separated into four tasks. First is the scanning of aerial photographs of volcanic and aeolian structures and flows. The second task is to scan field site images taken from ground and low-altitude aircraft of volcanic structures, lava flows, lava tubes, dunes, and wind streaks. The third image set to be scanned includes photographs of lab experiments from the NASA Planetary Aeolian Laboratory wind tunnels, vortex generator, and of wax models. Finally, rare NASA documents are being scanned and formatted as PDF files. Thousands of images are to be scanned for this project. Archiving of the data will follow the PDS4 standard, where the entire project is classified as a single bundle, with individual subjects (i.e., the Amboy Crater volcanic structure in the Mojave Desert of California) as collections. Within the collections, each image is considered a product, with a unique ID and associated XML document. Documents describing the image data, including the subject and context, will be included with each collection. Once complete, the data will be hosted by a PDS data node and available for public search and download. As one of the first earth analog datasets to be archived by the PDS, this project could prompt the digitizing and making available of historic datasets from other facilities for the scientific community.

Simultaneous compression and encryption of closely resembling images: application to video sequences and polarimetric images.

PubMed

Aldossari, M; Alfalou, A; Brosseau, C

2014-09-22

This study presents and validates an optimized method of simultaneous compression and encryption designed to process images with close spectra. This approach is well adapted to the compression and encryption of images of a time-varying scene but also to static polarimetric images. We use the recently developed spectral fusion method [Opt. Lett.35, 1914-1916 (2010)] to deal with the close resemblance of the images. The spectral plane (containing the information to send and/or to store) is decomposed in several independent areas which are assigned according a specific way. In addition, each spectrum is shifted in order to minimize their overlap. The dual purpose of these operations is to optimize the spectral plane allowing us to keep the low- and high-frequency information (compression) and to introduce an additional noise for reconstructing the images (encryption). Our results show that not only can the control of the spectral plane enhance the number of spectra to be merged, but also that a compromise between the compression rate and the quality of the reconstructed images can be tuned. We use a root-mean-square (RMS) optimization criterion to treat compression. Image encryption is realized at different security levels. Firstly, we add a specific encryption level which is related to the different areas of the spectral plane, and then, we make use of several random phase keys. An in-depth analysis at the spectral fusion methodology is done in order to find a good trade-off between the compression rate and the quality of the reconstructed images. Our new proposal spectral shift allows us to minimize the image overlap. We further analyze the influence of the spectral shift on the reconstructed image quality and compression rate. The performance of the multiple-image optical compression and encryption method is verified by analyzing several video sequences and polarimetric images.

Diagnostic Imaging Guidelines Implementation Study for Spinal Disorders

PubMed Central

Bussières, André E.; Laurencelle, Louis; Peterson, Cynthia

2010-01-01

Purpose: Implementation strategies of imaging guidelines can assist in reducing the number of radiographic examinations. This study aimed to compare the perceived need for diagnostic imaging before and after an educational intervention strategy. Methods: One hundred sixty Swiss chiropractors attending a conference were randomized to either receive a radiology workshop, reviewing appropriate indications for diagnostic imaging for adult spine disorders (n = 80), or be in a control group (CG). One group of 40 individuals dropped out from the CG due to logistic reasons. Participants in the intervention group were randomly assigned to three subgroups to evaluate the effect of an online reminder at midpoint. All participants underwent a pretest and a final test at 14–16 weeks. A posttest was administered to two subgroups at 8–10 weeks. Results: There was no difference between baseline scores, and overall scores for the pretest and the final tests for all four groups were not significantly different. However, the subgroup provided with access to a reminder performed significantly better than the subgroup with whom they were compared (F = 4.486; df = 1 and 30; p = .043). Guideline adherence was 50.5% (95% CI, 39.1–61.8) for the intervention group and 43.7% (95% CI, 23.7–63.6) for the CG at baseline. Adherence at follow-up was lower, but mean group differences remained insignificant. Conclusions: Online access to specific recommendations while making a clinical decision may favorably influence the intention to either order or not order imaging studies. However, a didactic presentation alone did not appear to change the perception for the need of diagnostic imaging studies. PMID:20480010

Insights into Brown Adipose Tissue Physiology as Revealed by Imaging Studies

PubMed Central

Izzi-Engbeaya, Chioma; Salem, Victoria; Atkar, Rajveer S; Dhillo, Waljit S

2014-01-01

There has been resurgence in interest in brown adipose tissue (BAT) following radiological and histological identification of metabolically active BAT in adult humans. Imaging enables BAT to be studied non-invasively and therefore imaging studies have contributed a significant amount to what is known about BAT function in humans. In this review the current knowledge (derived from imaging studies) about the prevalence, function, activity and regulation of BAT in humans (as well as relevant rodent studies), will be summarized. PMID:26167397

Scatterometry or imaging overlay: a comparative study

NASA Astrophysics Data System (ADS)

Hsu, Simon C. C.; Pai, Yuan Chi; Chen, Charlie; Yu, Chun Chi; Hsing, Henry; Wu, Hsing-Chien; Kuo, Kelly T. L.; Amir, Nuriel

2015-03-01

Most fabrication facilities today use imaging overlay measurement methods, as it has been the industry's reliable workhorse for decades. In the last few years, third-generation Scatterometry Overlay (SCOL™) or Diffraction Based Overlay (DBO-1) technology was developed, along another DBO technology (DBO-2). This development led to the question of where the DBO technology should be implemented for overlay measurements. Scatterometry has been adopted for high volume production in only few cases, always with imaging as a backup, but scatterometry overlay is considered by many as the technology of the future. In this paper we compare imaging overlay and DBO technologies by means of measurements and simulations. We outline issues and sensitivities for both technologies, providing guidelines for the best implementation of each. For several of the presented cases, data from two different DBO technologies are compared as well, the first with Pupil data access (DBO-1) and the other without pupil data access (DBO-2). Key indicators of overlay measurement quality include: layer coverage, accuracy, TMU, process robustness and robustness to process changes. Measurement data from real cases across the industry are compared and the conclusions are also backed by simulations. Accuracy is benchmarked with reference OVL, and self-consistency, showing good results for Imaging and DBO-1 technology. Process sensitivity and metrology robustness are mostly simulated with MTD (Metrology Target Designer) comparing the same process variations for both technologies. The experimental data presented in this study was done on ten advanced node layers and three production node layers, for all phases of the IC fabrication process (FEOL, MEOL and BEOL). The metrology tool used for most of the study is KLA-Tencor's Archer 500LCM system (scatterometry-based and imaging-based measurement technologies on the same tool) another type of tool is used for DBO-2 measurements. Finally, we conclude that

Investigation of the Secondary School Students' Images of Scientists

ERIC Educational Resources Information Center

Akgün, Abuzer

2016-01-01

The overall purpose of this study is to explore secondary school students' images of scientists. In addition to this comprehensive purpose, it is also investigated that if these students' current images of scientists and those in which they see themselves as a scientist in the near future are consistent or not. The study was designed in line with…

Diffusion-weighted imaging of the sellar region: a comparison study of BLADE and single-shot echo planar imaging sequences.

PubMed

Yiping, Lu; Hui, Liu; Kun, Zhou; Daoying, Geng; Bo, Yin

2014-07-01

The purpose of this study is to compare BLADE diffusion-weighted imaging (DWI) with single-shot echo planar imaging (EPI) DWI on the aspects of feasibility of imaging the sellar region and image quality. A total of 3 healthy volunteers and 52 patients with suspected lesions in the sellar region were included in this prospective intra-individual study. All exams were performed at 3.0T with a BLADE DWI sequence and a standard single-shot EP-DWI sequence. Phantom measurements were performed to measure the objective signal-to-noise ratio (SNR). Two radiologists rated the image quality according to the visualisation of the internal carotid arteries, optic chiasm, pituitary stalk, pituitary gland and lesion, and the overall image quality. One radiologist measured lesion sizes for detecting their relationship with the image score. The SNR in BLADE DWI sequence showed no significant difference from the single-shot EPI sequence (P>0.05). All of the assessed regions received higher scores in BLADE DWI images than single-shot EP-DWI. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

FRET Imaging in Three-dimensional Hydrogels

PubMed Central

Taboas, Juan M.

2016-01-01

Imaging of Förster resonance energy transfer (FRET) is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly employ two-dimensional (2D) culture, which does not mimic the three-dimensional (3D) cellular microenvironment. A method to perform quenched emission FRET imaging using conventional widefield epifluorescence microscopy of cells within a 3D hydrogel environment is presented. Here an analysis method for ratiometric FRET probes that yields linear ratios over the probe activation range is described. Measurement of intracellular cyclic adenosine monophosphate (cAMP) levels is demonstrated in chondrocytes under forskolin stimulation using a probe for EPAC1 activation (ICUE1) and the ability to detect differences in cAMP signaling dependent on hydrogel material type, herein a photocrosslinking hydrogel (PC-gel, polyethylene glycol dimethacrylate) and a thermoresponsive hydrogel (TR-gel). Compared with 2D FRET methods, this method requires little additional work. Laboratories already utilizing FRET imaging in 2D can easily adopt this method to perform cellular studies in a 3D microenvironment. It can further be applied to high throughput drug screening in engineered 3D microtissues. Additionally, it is compatible with other forms of FRET imaging, such as anisotropy measurement and fluorescence lifetime imaging (FLIM), and with advanced microscopy platforms using confocal, pulsed, or modulated illumination. PMID:27500354

Lucky imaging multiplicity studies of exoplanet host stars

NASA Astrophysics Data System (ADS)

Ginski, C.; Mugrauer, M.; Neuhäuser, R.

2014-03-01

The multiplicity of stars is an important parameter in order to understand star and planet formation. In the past decades extrasolar planets have been discovered around more than 600 stars with the radial velocity and transit techniques. Many of these systems present extreme cases of massive planetary objects at very close separations to their primary stars. To explain the configurations of such systems is hence a continued challenge in the development of formation theories. It will be very interesting to determine if there are significant differences between planets in single and multiple star systems. In our ongoing study we use high resolution imaging techniques to clarify the multiplicity status of nearby (within 250 pc) planet host stars. For targets on the northern hemisphere we employ the lucky imaging instrument Astralux at the 2.2 m telescope of the Calar Alto Observatory. The lucky imaging approach consists of taking several thousand short images with integration times shorter than the speckle coherence time, to sample the speckle variations during the observation window. We then only choose the so called "lucky shots" with a very high Strehl ratio in one of the speckles, to shift and add, resulting in a final image with the highest possible Strehl ratio and therefore highest possible angular resolution. We will present recent results of our study at the Calar Alto Observatory, as well as observations undertaken with the RTK camera at the 20 cm guiding telescope in our own observatory in Großschwabhausen.

An Imaging And Graphics Workstation For Image Sequence Analysis

NASA Astrophysics Data System (ADS)

Mostafavi, Hassan

1990-01-01

This paper describes an application-specific engineering workstation designed and developed to analyze imagery sequences from a variety of sources. The system combines the software and hardware environment of the modern graphic-oriented workstations with the digital image acquisition, processing and display techniques. The objective is to achieve automation and high throughput for many data reduction tasks involving metric studies of image sequences. The applications of such an automated data reduction tool include analysis of the trajectory and attitude of aircraft, missile, stores and other flying objects in various flight regimes including launch and separation as well as regular flight maneuvers. The workstation can also be used in an on-line or off-line mode to study three-dimensional motion of aircraft models in simulated flight conditions such as wind tunnels. The system's key features are: 1) Acquisition and storage of image sequences by digitizing real-time video or frames from a film strip; 2) computer-controlled movie loop playback, slow motion and freeze frame display combined with digital image sharpening, noise reduction, contrast enhancement and interactive image magnification; 3) multiple leading edge tracking in addition to object centroids at up to 60 fields per second from both live input video or a stored image sequence; 4) automatic and manual field-of-view and spatial calibration; 5) image sequence data base generation and management, including the measurement data products; 6) off-line analysis software for trajectory plotting and statistical analysis; 7) model-based estimation and tracking of object attitude angles; and 8) interface to a variety of video players and film transport sub-systems.

Buried Target Imaging: A Comparative Study

NASA Astrophysics Data System (ADS)

Ghaderi Aram, Morteza; Dehmollaian, Mojtaba; Khaleghi, Ali

2017-12-01

A wide variety of qualitative methods have been proposed for microwave imaging. It is difficult to select only one of these methods based on a priori information and measurement equipment to achieve a reliable reconstruction. Various arrangements for antennas to be used in, for instance, have been proposed which have direct impacts on the complexity of inverse methods as well as the quality of output images. In this study, four qualitative methods of the linear sampling method (LSM), time reversal (TR), diffraction tomography (DT), and back-projection (BP) have been reviewed in a 2D scenario; the performance of the methods is compared within the same framework of a multi-static configuration. The goal is to compare their resolutions and determine their advantages and drawbacks. It is shown that LSM provides the best azimuth resolution but the worst range resolution. It is almost invariant to dielectric contrast and is appropriate for a wide range of dielectric contrasts and relatively large objects. It is also shown that at relatively low dielectric contrasts, TR images are most similar to the true object, show fewer artifacts, and offer high immunity to noise. While suffering from more artifacts due to the presence of some ghost images, DT offers the best range resolution. The results also show that BP has the worst azimuth resolution when reconstructing deeply-buried targets, although its implementation is straightforward and not computationally complex.

Feasibility study and quality assessment of unmanned aircraft system-derived multispectral images

NASA Astrophysics Data System (ADS)

Chang, Kuo-Jen

2017-04-01

The purpose of study is to explore the precision and the applicability of UAS-derived multispectral images. In this study, the Micro-MCA6 multispectral camera was mounted on quadcopter. The Micro-MCA6 shoot images synchronized of each single band. By means of geotagged images and control points, the orthomosaic images of each single band generated firstly by 14cm resolution. The multispectral image was merged complete with 6 bands. In order to improve the spatial resolution, the 6 band image fused with 9cm resolution image taken from RGB camera. Quality evaluation of the image is verified of the each single band by using control points and check points. The standard deviations of errors are within 1 to 2 pixel resolution of each band. The quality of the multispectral image is compared with 3 cm resolution orthomosaic RGB image gathered from UAV in the same mission, as well. The standard deviations of errors are within 2 to 3 pixel resolution. The result shows that the errors resulting from the blurry and the band dislocation of the objects edge identification. To the end, the normalized difference vegetation index (NDVI) extracted from the image to explore the condition of vegetation and the nature of the environment. This study demonstrates the feasibility and the capability of the high resolution multispectral images.

Deploying swarm intelligence in medical imaging identifying metastasis, micro-calcifications and brain image segmentation.

PubMed

al-Rifaie, Mohammad Majid; Aber, Ahmed; Hemanth, Duraiswamy Jude

2015-12-01

This study proposes an umbrella deployment of swarm intelligence algorithm, such as stochastic diffusion search for medical imaging applications. After summarising the results of some previous works which shows how the algorithm assists in the identification of metastasis in bone scans and microcalcifications on mammographs, for the first time, the use of the algorithm in assessing the CT images of the aorta is demonstrated along with its performance in detecting the nasogastric tube in chest X-ray. The swarm intelligence algorithm presented in this study is adapted to address these particular tasks and its functionality is investigated by running the swarms on sample CT images and X-rays whose status have been determined by senior radiologists. In addition, a hybrid swarm intelligence-learning vector quantisation (LVQ) approach is proposed in the context of magnetic resonance (MR) brain image segmentation. The particle swarm optimisation is used to train the LVQ which eliminates the iteration-dependent nature of LVQ. The proposed methodology is used to detect the tumour regions in the abnormal MR brain images.

Imaging of thymic disorders

PubMed Central

Bogot, Naama R; Quint, Leslie E

2005-01-01

Evaluation of the thymus poses a challenge to the radiologist. In addition to age-related changes in thymic size, shape, and tissue composition, there is considerable variability in the normal adult thymic appearance within any age group. Many different types of disorders may affect the thymus, including hyperplasia, cysts, and benign and malignant neoplasms, both primary and secondary; clinical and imaging findings typical for each disease process are described in this article. Whereas computed tomography is the mainstay for imaging the thymus, other imaging modalities may occasionally provide additional structural or functional information. PMID:16361143

Plenoptic Ophthalmoscopy: A Novel Imaging Technique.

PubMed

Adam, Murtaza K; Aenchbacher, Weston; Kurzweg, Timothy; Hsu, Jason

2016-11-01

This prospective retinal imaging case series was designed to establish feasibility of plenoptic ophthalmoscopy (PO), a novel mydriatic fundus imaging technique. A custom variable intensity LED array light source adapter was created for the Lytro Gen1 light-field camera (Lytro, Mountain View, CA). Initial PO testing was performed on a model eye and rabbit fundi. PO image acquisition was then performed on dilated human subjects with a variety of retinal pathology and images were subjected to computational enhancement. The Lytro Gen1 light-field camera with custom LED array captured fundus images of eyes with diabetic retinopathy, age-related macular degeneration, retinal detachment, and other diagnoses. Post-acquisition computational processing allowed for refocusing and perspective shifting of retinal PO images, resulting in improved image quality. The application of PO to image the ocular fundus is feasible. Additional studies are needed to determine its potential clinical utility. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1038-1043.]. Copyright 2016, SLACK Incorporated.

MRI and Additive Manufacturing of Nasal Alar Constructs for Patient-specific Reconstruction.

PubMed

Visscher, Dafydd O; van Eijnatten, Maureen; Liberton, Niels P T J; Wolff, Jan; Hofman, Mark B M; Helder, Marco N; Don Griot, J Peter W; Zuijlen, Paul P M van

2017-08-30

Surgical reconstruction of cartilaginous defects remains a major challenge. In the current study, we aimed to identify an imaging strategy for the development of patient-specific constructs that aid in the reconstruction of nasal deformities. Magnetic Resonance Imaging (MRI) was performed on a human cadaver head to find the optimal MRI sequence for nasal cartilage. This sequence was subsequently used on a volunteer. Images of both were assessed by three independent researchers to determine measurement error and total segmentation time. Three dimensionally (3D) reconstructed alar cartilage was then additively manufactured. Validity was assessed by comparing manually segmented MR images to the gold standard (micro-CT). Manual segmentation allowed delineation of the nasal cartilages. Inter- and intra-observer agreement was acceptable in the cadaver (coefficient of variation 4.6-12.5%), but less in the volunteer (coefficient of variation 0.6-21.9%). Segmentation times did not differ between observers (cadaver P = 0.36; volunteer P = 0.6). The lateral crus of the alar cartilage was consistently identified by all observers, whereas part of the medial crus was consistently missed. This study suggests that MRI is a feasible imaging modality for the development of 3D alar constructs for patient-specific reconstruction.

Wideband late gadolinium enhanced magnetic resonance imaging for imaging myocardial scar without image artefacts induced by implantable cardioverter-defibrillator: a feasibility study at 3 T

PubMed Central

Ranjan, Ravi; McGann, Christopher J.; Jeong, Eun-Kee; Hong, KyungPyo; Kholmovski, Eugene G.; Blauer, Josh; Wilson, Brent D.; Marrouche, Nassir F.; Kim, Daniel

2015-01-01

Aim Late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) is a useful tool for facilitating ventricular tachycardia (VT) ablation. Unfortunately, most VT ablation candidates often have prophylactic implantable cardioverter-defibrillator (ICD) and do not undergo cardiac MRI largely due to image artefacts generated by ICD. A prior study has reported success of ‘wideband’ LGE MRI for imaging myocardial scar without image artefacts induced by ICD at 1.5T. The purpose of this study was to widen the availability of wideband LGE MRI to 3T, since it has the potential to achieve higher spatial resolution than 1.5T. Methods and results We compared the performance of standard and wideband LGE MRI pulse sequences in phantoms and canines with myocardial lesions created by radiofrequency ablation. Standard LGE MRI produced image artefacts induced by ICD and 49% accuracy in detecting 97 myocardial scars examined in this study, whereas wideband LGE MRI produced artefact-free images and 94% accuracy in detecting scars. The mean image quality score (1 = nondiagnostic, 2 = poor, 3 = adequate, 4 = good, 5 = excellent) was significantly (P < 0.001) higher for wideband (3.7 ± 0.8) than for standard LGE MRI (2.1 ± 0.7). The mean artefact level score (1 = minimal, 2 = mild, 3 = moderate, 4 = severe, 5 = nondiagnostic) was significantly (P < 0.001) lower for wideband (2.1 ± 0.8) than for standard LGE MRI (4.0 ± 0.6). Wideband LGE MRI agreed better with gross pathology than standard LGE MRI. Conclusion This study demonstrates the feasibility of wideband LGE MRI for suppression of image artefacts induced by ICD at 3T. PMID:25336666

Image Quality in High-resolution and High-cadence Solar Imaging

NASA Astrophysics Data System (ADS)

Denker, C.; Dineva, E.; Balthasar, H.; Verma, M.; Kuckein, C.; Diercke, A.; González Manrique, S. J.

2018-03-01

Broad-band imaging and even imaging with a moderate bandpass (about 1 nm) provides a photon-rich environment, where frame selection (lucky imaging) becomes a helpful tool in image restoration, allowing us to perform a cost-benefit analysis on how to design observing sequences for imaging with high spatial resolution in combination with real-time correction provided by an adaptive optics (AO) system. This study presents high-cadence (160 Hz) G-band and blue continuum image sequences obtained with the High-resolution Fast Imager (HiFI) at the 1.5-meter GREGOR solar telescope, where the speckle-masking technique is used to restore images with nearly diffraction-limited resolution. The HiFI employs two synchronized large-format and high-cadence sCMOS detectors. The median filter gradient similarity (MFGS) image-quality metric is applied, among others, to AO-corrected image sequences of a pore and a small sunspot observed on 2017 June 4 and 5. A small region of interest, which was selected for fast-imaging performance, covered these contrast-rich features and their neighborhood, which were part of Active Region NOAA 12661. Modifications of the MFGS algorithm uncover the field- and structure-dependency of this image-quality metric. However, MFGS still remains a good choice for determining image quality without a priori knowledge, which is an important characteristic when classifying the huge number of high-resolution images contained in data archives. In addition, this investigation demonstrates that a fast cadence and millisecond exposure times are still insufficient to reach the coherence time of daytime seeing. Nonetheless, the analysis shows that data acquisition rates exceeding 50 Hz are required to capture a substantial fraction of the best seeing moments, significantly boosting the performance of post-facto image restoration.

[Imaging center - optimization of the imaging process].

PubMed

Busch, H-P

2013-04-01

Hospitals around the world are under increasing pressure to optimize the economic efficiency of treatment processes. Imaging is responsible for a great part of the success but also of the costs of treatment. In routine work an excessive supply of imaging methods leads to an "as well as" strategy up to the limit of the capacity without critical reflection. Exams that have no predictable influence on the clinical outcome are an unjustified burden for the patient. They are useless and threaten the financial situation and existence of the hospital. In recent years the focus of process optimization was exclusively on the quality and efficiency of performed single examinations. In the future critical discussion of the effectiveness of single exams in relation to the clinical outcome will be more important. Unnecessary exams can be avoided, only if in addition to the optimization of single exams (efficiency) there is an optimization strategy for the total imaging process (efficiency and effectiveness). This requires a new definition of processes (Imaging Pathway), new structures for organization (Imaging Center) and a new kind of thinking on the part of the medical staff. Motivation has to be changed from gratification of performed exams to gratification of process quality (medical quality, service quality, economics), including the avoidance of additional (unnecessary) exams. © Georg Thieme Verlag KG Stuttgart · New York.

A Comparative Study on Diagnostic Accuracy of Colour Coded Digital Images, Direct Digital Images and Conventional Radiographs for Periapical Lesions – An In Vitro Study

PubMed Central

Mubeen; K.R., Vijayalakshmi; Bhuyan, Sanat Kumar; Panigrahi, Rajat G; Priyadarshini, Smita R; Misra, Satyaranjan; Singh, Chandravir

2014-01-01

Objectives: The identification and radiographic interpretation of periapical bone lesions is important for accurate diagnosis and treatment. The present study was undertaken to study the feasibility and diagnostic accuracy of colour coded digital radiographs in terms of presence and size of lesion and to compare the diagnostic accuracy of colour coded digital images with direct digital images and conventional radiographs for assessing periapical lesions. Materials and Methods: Sixty human dry cadaver hemimandibles were obtained and periapical lesions were created in first and second premolar teeth at the junction of cancellous and cortical bone using a micromotor handpiece and carbide burs of sizes 2, 4 and 6. After each successive use of round burs, a conventional, RVG and colour coded image was taken for each specimen. All the images were evaluated by three observers. The diagnostic accuracy for each bur and image mode was calculated statistically. Results: Our results showed good interobserver (kappa > 0.61) agreement for the different radiographic techniques and for the different bur sizes. Conventional Radiography outperformed Digital Radiography in diagnosing periapical lesions made with Size two bur. Both were equally diagnostic for lesions made with larger bur sizes. Colour coding method was least accurate among all the techniques. Conclusion: Conventional radiography traditionally forms the backbone in the diagnosis, treatment planning and follow-up of periapical lesions. Direct digital imaging is an efficient technique, in diagnostic sense. Colour coding of digital radiography was feasible but less accurate however, this imaging technique, like any other, needs to be studied continuously with the emphasis on safety of patients and diagnostic quality of images. PMID:25584318

Noise Power Spectrum in PROPELLER MR Imaging.

PubMed

Ichinoseki, Yuki; Nagasaka, Tatsuo; Miyamoto, Kota; Tamura, Hajime; Mori, Issei; Machida, Yoshio

2015-01-01

The noise power spectrum (NPS), an index for noise evaluation, represents the frequency characteristics of image noise. We measured the NPS in PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) magnetic resonance (MR) imaging, a nonuniform data sampling technique, as an initial study for practical MR image evaluation using the NPS. The 2-dimensional (2D) NPS reflected the k-space sampling density and showed agreement with the shape of the k-space trajectory as expected theoretically. Additionally, the 2D NPS allowed visualization of a part of the image reconstruction process, such as filtering and motion correction.

Fluorescence Imaging Study of Impinging Underexpanded Jets

NASA Technical Reports Server (NTRS)

Inman, Jennifer A.; Danehy, Paul M.; Nowak, Robert J.; Alderfer, David W.

2008-01-01

An experiment was designed to create a simplified simulation of the flow through a hole in the surface of a hypersonic aerospace vehicle and the subsequent impingement of the flow on internal structures. In addition to planar laser-induced fluorescence (PLIF) flow visualization, pressure measurements were recorded on the surface of an impingement target. The PLIF images themselves provide quantitative spatial information about structure of the impinging jets. The images also help in the interpretation of impingement surface pressure profiles by highlighting the flow structures corresponding to distinctive features of these pressure profiles. The shape of the pressure distribution along the impingement surface was found to be double-peaked in cases with a sufficiently high jet-exit-to-ambient pressure ratio so as to have a Mach disk, as well as in cases where a flow feature called a recirculation bubble formed at the impingement surface. The formation of a recirculation bubble was in turn found to depend very sensitively upon the jet-exit-to-ambient pressure ratio. The pressure measured at the surface was typically less than half the nozzle plenum pressure at low jet pressure ratios and decreased with increasing jet pressure ratios. Angled impingement cases showed that impingement at a 60deg angle resulted in up to a factor of three increase in maximum pressure at the plate compared to normal incidence.

Flickr's Potential as an Academic Image Resource: An Exploratory Study

ERIC Educational Resources Information Center

Angus, Emma; Stuart, David; Thelwall, Mike

2010-01-01

Many web 2.0 sites are extremely popular and contain vast amounts of content, but how much of this content is useful in academia? This exploratory paper investigates the potential use of the popular web 2.0 image site Flickr as an academic image resource. The study identified images tagged with any one of 12 subject names derived from recognized…

Implementing desktop image access of GI images

NASA Astrophysics Data System (ADS)

Grevera, George J.; Feingold, Eric R.; Horii, Steven C.; Laufer, Igor

1996-05-01

In this paper we present a specific example of the current state-of-the-art in desktop image access in the GI section of the Department of Radiology at the Hospital of the University of Pennsylvania. We describe a system which allows physicians to view and manipulate images from a Philips digital fluoroscopy system at the workstations in their offices. Typically they manipulate and view these images on their desktop Macs and then submit the results for slide making or save the images in digital teaching files. In addition to a discussion of the current state-of-the-art here at HUP, we also discuss some future directions that we are pursuing.

Image-adaptive and robust digital wavelet-domain watermarking for images

NASA Astrophysics Data System (ADS)

Zhao, Yi; Zhang, Liping

2018-03-01

We propose a new frequency domain wavelet based watermarking technique. The key idea of our scheme is twofold: multi-tier solution representation of image and odd-even quantization embedding/extracting watermark. Because many complementary watermarks need to be hidden, the watermark image designed is image-adaptive. The meaningful and complementary watermark images was embedded into the original image (host image) by odd-even quantization modifying coefficients, which was selected from the detail wavelet coefficients of the original image, if their magnitudes are larger than their corresponding Just Noticeable Difference thresholds. The tests show good robustness against best-known attacks such as noise addition, image compression, median filtering, clipping as well as geometric transforms. Further research may improve the performance by refining JND thresholds.

Dimensional schizotypy and social cognition: an fMRI imaging study.

PubMed

Wang, Yi; Liu, Wen-Hua; Li, Zhi; Wei, Xin-Hua; Jiang, Xin-Qing; Neumann, David L; Shum, David H K; Cheung, Eric F C; Chan, Raymond C K

2015-01-01

Impairment in empathy has been demonstrated in patients with schizophrenia and individuals with psychosis proneness. In the present study, we examined the neural correlates underlying theory of mind (ToM) and empathy and the relationships between these two social cognitive abilities with schizotypy. Fifty-six first-year college students (31 males, 25 females) between 17 and 21 years of age (M = 19.3, SD = 0.9) from a medical university in China participated. All participants undertook a comic strips functional imaging task that specifically examined both empathy and ToM. In addition, they completed two self-report scales: the Chapman Psychosis Proneness scale and the Interpersonal Responsivity Index (IRI). Results showed that both empathy and ToM conditions of the task were associated with brain activity in the middle temporal gyrus, the temporo-parietal junction (TPJ), the precuneus and the posterior cingulate gyrus. In addition, we found positive correlations between negative schizotypy and brain activity in regions involved in social cognition, namely, the middle temporal gyrus, the TPJ, as well as the medial prefrontal gyrus. These findings highlight that different dimensions of schizotypy may show different associations with brain regions involved in social cognitive abilities. More importantly, the positive correlation between brain activity and anhedonia suggests the presence of compensatory mechanisms in high-risk populations.

Towards Development of a Field-Deployable Imaging Device for TBI

DTIC Science & Technology

2012-03-01

centers such as in Germany for those studies, as well as additional medical care. This is because magnetic resonance imaging is unavailable in or near...detection of stroke in areas 283 where CAT scans and magnetic resonance imaging are not readily available or appropriate. 284 285 ACKNOWLEDGEMENTS...Task (3): MR image rodent brains. 3) UVA has performed its first round of MRI studies of CCI rats – Figures 1a,b,c. Task (4): Immunohistochemical

Dose and diagnostic image quality in digital tomosynthesis imaging of facial bones in pediatrics

NASA Astrophysics Data System (ADS)

King, J. M.; Hickling, S.; Elbakri, I. A.; Reed, M.; Wrogemann, J.

2011-03-01

The purpose of this study was to evaluate the use of digital tomosynthesis (DT) for pediatric facial bone imaging. We compared the eye lens dose and diagnostic image quality of DT facial bone exams relative to digital radiography (DR) and computed tomography (CT), and investigated whether we could modify our current DT imaging protocol to reduce patient dose while maintaining sufficient diagnostic image quality. We measured the dose to the eye lens for all three modalities using high-sensitivity thermoluminescent dosimeters (TLDs) and an anthropomorphic skull phantom. To assess the diagnostic image quality of DT compared to the corresponding DR and CT images, we performed an observer study where the visibility of anatomical structures in the DT phantom images were rated on a four-point scale. We then acquired DT images at lower doses and had radiologists indicate whether the visibility of each structure was adequate for diagnostic purposes. For typical facial bone exams, we measured eye lens doses of 0.1-0.4 mGy for DR, 0.3-3.7 mGy for DT, and 26 mGy for CT. In general, facial bone structures were visualized better with DT then DR, and the majority of structures were visualized well enough to avoid the need for CT. DT imaging provides high quality diagnostic images of the facial bones while delivering significantly lower doses to the lens of the eye compared to CT. In addition, we found that by adjusting the imaging parameters, the DT effective dose can be reduced by up to 50% while maintaining sufficient image quality.

Research on Hartmann test for progressive addition lenses

NASA Astrophysics Data System (ADS)

Qin, Lin-ling; Yu, Jing-chi

2009-05-01

Recently, in the world some growing-up measurements for Progressive addition lenses and relevant equipments have been developed. They are single point measurement, moiré deflectometry, Ronchi test techniques. Hartmann test for Progressive addition lenses is proposed in the article. The measurement principle of Hartmann test for ophthalmic lenses and the power compensation of off-axis rays are introduced. The experimental setup used to test lenses is put forward. For experimental test, a spatial filter is used for selecting a clean Gaussian beam; a collimating lens with focal distance f =300 mm is used to produce collimated beam. The Hartmann plate with a square array of holes separated at 2 mm is selected. The selection of laser and CCD camera is critical to the accuracy of experiment and the image processing algorithm. The spot patterns from CCD are obtained from the experimental tests. The power distribution map for lenses can be obtained by image processing in theory. The results indicate that Hartmann test for Progressive addition lenses is convenient and feasible; also its structure is simple.

High resolution imaging at Palomar

NASA Technical Reports Server (NTRS)

Kulkarni, Shrinivas R.

1992-01-01

For the last two years we have embarked on a program of understanding the ultimate limits of ground-based optical imaging. We have designed and fabricated a camera specifically for high resolution imaging. This camera has now been pressed into service at the prime focus of the Hale 5 m telescope. We have concentrated on two techniques: the Non-Redundant Masking (NRM) and Weigelt's Fully Filled Aperture (FFA) method. The former is the optical analog of radio interferometry and the latter is a higher order extension of the Labeyrie autocorrelation method. As in radio Very Long Baseline Interferometry (VLBI), both these techniques essentially measure the closure phase and, hence, true image construction is possible. We have successfully imaged binary stars and asteroids with angular resolution approaching the diffraction limit of the telescope and image quality approaching that of a typical radio VLBI map. In addition, we have carried out analytical and simulation studies to determine the ultimate limits of ground-based optical imaging, the limits of space-based interferometric imaging, and investigated the details of imaging tradeoffs of beam combination in optical interferometers.

Fusion imaging: a novel staging modality in testis cancer.

PubMed

Sterbis, Joseph R; Rice, Kevin R; Javitt, Marcia C; Schenkman, Noah S; Brassell, Stephen A

2010-11-05

Computed tomography and chest radiographs provide the standard imaging for staging, treatment, and surveillance of testicular germ cell neoplasms. Positron emission tomography has recently been utilized for staging, but is somewhat limited in its ability to provide anatomic localization. Fusion imaging combines the metabolic information provided by positron emission tomography with the anatomic precision of computed tomography. To the best of our knowledge, this represents the first study of the effectiveness using fusion imaging in evaluation of patients with testis cancer. A prospective study of 49 patients presenting to Walter Reed Army Medical Center with testicular cancer from 2003 to 2009 was performed. Fusion imaging was compared with conventional imaging, tumor markers, pathologic results, and clinical follow-up. There were 14 true positives, 33 true negatives, 1 false positive, and 1 false negative. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.3, 97.0, 93.3, and 97.0% respectively. In 11 patient scenarios, fusion imaging differed from conventional imaging. Utility was found in superior lesion detection compared to helical computed tomography due to anatomical/functional image co-registration, detection of micrometastasis in lymph nodes (pathologic nodes < 1cm), surveillance for recurrence post-chemotherapy, differentiating fibrosis from active disease in nodes < 2.5cm, and acting as a quality assurance measure to computed tomography alone. In addition to demonstrating a sensitivity and specificity comparable or superior to conventional imaging, fusion imaging shows promise in providing additive data that may assist in clinical decision-making.

Image Viewer using Digital Imaging and Communications in Medicine (DICOM)

NASA Astrophysics Data System (ADS)

Baraskar, Trupti N.

2010-11-01

Digital Imaging and Communications in Medicine is a standard for handling, storing, printing, and transmitting information in medical imaging. The National Electrical Manufacturers Association holds the copyright to this standard. It was developed by the DICOM Standards committee. The other image viewers cannot collectively store the image details as well as the patient's information. So the image may get separated from the details, but DICOM file format stores the patient's information and the image details. Main objective is to develop a DICOM image viewer. The image viewer will open .dcm i.e. DICOM image file and also will have additional features such as zoom in, zoom out, black and white inverter, magnifier, blur, B/W inverter, horizontal and vertical flipping, sharpening, contrast, brightness and .gif converter are incorporated.

Image segmentation with a novel regularized composite shape prior based on surrogate study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Tingting, E-mail: tingtingzhao@mednet.ucla.edu; Ruan, Dan, E-mail: druan@mednet.ucla.edu

Purpose: Incorporating training into image segmentation is a good approach to achieve additional robustness. This work aims to develop an effective strategy to utilize shape prior knowledge, so that the segmentation label evolution can be driven toward the desired global optimum. Methods: In the variational image segmentation framework, a regularization for the composite shape prior is designed to incorporate the geometric relevance of individual training data to the target, which is inferred by an image-based surrogate relevance metric. Specifically, this regularization is imposed on the linear weights of composite shapes and serves as a hyperprior. The overall problem is formulatedmore » in a unified optimization setting and a variational block-descent algorithm is derived. Results: The performance of the proposed scheme is assessed in both corpus callosum segmentation from an MR image set and clavicle segmentation based on CT images. The resulted shape composition provides a proper preference for the geometrically relevant training data. A paired Wilcoxon signed rank test demonstrates statistically significant improvement of image segmentation accuracy, when compared to multiatlas label fusion method and three other benchmark active contour schemes. Conclusions: This work has developed a novel composite shape prior regularization, which achieves superior segmentation performance than typical benchmark schemes.« less

Non-invasive imaging of skin cancer with fluorescence lifetime imaging using two photon tomography

NASA Astrophysics Data System (ADS)

Patalay, Rakesh; Talbot, Clifford; Alexandrov, Yuriy; Munro, Ian; Breunig, Hans Georg; König, Karsten; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Christopher

2011-07-01

Multispectral fluorescence lifetime imaging (FLIM) using two photon microscopy as a non-invasive technique for the diagnosis of skin lesions is described. Skin contains fluorophores including elastin, keratin, collagen, FAD and NADH. This endogenous contrast allows tissue to be imaged without the addition of exogenous agents and allows the in vivo state of cells and tissues to be studied. A modified DermaInspect® multiphoton tomography system was used to excite autofluorescence at 760 nm in vivo and on freshly excised ex vivo tissue. This instrument simultaneously acquires fluorescence lifetime images in four spectral channels between 360-655 nm using time-correlated single photon counting and can also provide hyperspectral images. The multispectral fluorescence lifetime images were spatially segmented and binned to determine lifetimes for each cell by fitting to a double exponential lifetime model. A comparative analysis between the cellular lifetimes from different diagnoses demonstrates significant diagnostic potential.

A study of the additional costs of dispensing workers' compensation prescriptions.

PubMed

Schafermeyer, Kenneth W

2007-03-01

Although there is a significant amount of additional work involved in dispensing workers' compensation prescriptions, these costs have not been quantified. A study of the additional costs to dispense a workers' compensation prescription is needed to measure actual costs and to help determine the reasonableness of reimbursement for prescriptions dispensed under workers' compensation programs. The purpose of this study was to determine the minimum additional time and costs required to dispense workers' compensation prescriptions in Texas. A convenience sample of 30 store-level pharmacy staff members involved in submitting and processing prescription claims for the Texas Mutual workers' compensation program were interviewed by telephone. Data collected to determine the additional costs of dispensing a workers' compensation prescription included (1) the amount of additional time and personnel costs required to dispense and process an average workers' compensation prescription claim, (2) the difference in time required for a new versus a refilled prescription, (3) overhead costs for processing workers' compensation prescription claims by experienced experts at a central processing facility, (4) carrying costs for workers' compensation accounts receivable, and (5) bad debts due to uncollectible workers' compensation claims. The median of the sample pharmacies' additional costs for dispensing a workers' compensation prescription was estimated to be at least $9.86 greater than for a cash prescription. This study shows that the estimated costs for workers' compensation prescriptions were significantly higher than for cash prescriptions. These costs are probably much more than most employers, workers' compensation payers, and pharmacy managers would expect. It is recommended that pharmacy managers should estimate their own costs and compare these costs to actual reimbursement when considering the reasonableness of workers' compensation prescriptions and whether to accept

A Prospective Study of the Utility of Magnetic Resonance Imaging in Determining Candidacy for Partial Breast Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorn, Paige L.; Al-Hallaq, Hania A.; Haq, Farah

2013-03-01

Purpose: Retrospective data have demonstrated that breast magnetic resonance imaging (MRI) may change a patient's eligibility for partial breast irradiation (PBI) by identifying multicentric, multifocal, or contralateral disease. The objective of the current study was to prospectively determine the frequency with which MRI identifies occult disease and to establish clinical factors associated with a higher likelihood of MRI prompting changes in PBI eligibility. Methods and Materials: At The University of Chicago, women with breast cancer uniformly undergo MRI in addition to mammography and ultrasonography. From June 2009 through May 2011, all patients were screened prospectively in a multidisciplinary conference formore » PBI eligibility based on standard imaging, and the impact of MRI on PBI eligibility according to National Surgical Adjuvant Breast and Bowel Project protocol B-39/Radiation Therapy Oncology Group protocol 0413 entry criteria was recorded. Univariable analysis was performed using clinical characteristics in both the prospective cohort and in a separate cohort of retrospectively identified patients. Pooled analysis was used to derive a scoring index predictive of the risk that MRI would identify additional disease. Results: A total of 521 patients were screened for PBI eligibility, and 124 (23.8%) patients were deemed eligible for PBI based on standard imaging. MRI findings changed PBI eligibility in 12.9% of patients. In the pooled univariable analysis, tumor size ≥2 cm on mammography or ultrasonography (P=.02), age <50 years (P=.01), invasive lobular histology (P=.01), and HER-2/neu amplification (P=.01) were associated with a higher likelihood of MRI changing PBI eligibility. A predictive score was generated by summing the number of significant risk factors. Patients with a score of 0, 1, 2, and 3 had changes to eligibility based on MRI findings in 2.8%, 13.2%, 38.1%, and 100%, respectively (P<.0001). Conclusions: MRI identified additional

Studies of auroral X-ray imaging from high altitude spacecraft

NASA Technical Reports Server (NTRS)

Mckenzie, D. L.; Mizera, P. F.; Rice, C. J.

1980-01-01

Results of a study of techniques for imaging the aurora from a high altitude satellite at X-ray wavelengths are summarized. The X-ray observations allow the straightforward derivation of the primary auroral X-ray spectrum and can be made at all local times, day and night. Five candidate imaging systems are identified: X-ray telescope, multiple pinhole camera, coded aperture, rastered collimator, and imaging collimator. Examples of each are specified, subject to common weight and size limits which allow them to be intercompared. The imaging ability of each system is tested using a wide variety of sample spectra which are based on previous satellite observations. The study shows that the pinhole camera and coded aperture are both good auroral imaging systems. The two collimated detectors are significantly less sensitive. The X-ray telescope provides better image quality than the other systems in almost all cases, but a limitation to energies below about 4 keV prevents this system from providing the spectra data essential to deriving electron spectra, energy input to the atmosphere, and atmospheric densities and conductivities. The orbit selection requires a tradeoff between spatial resolution and duty cycle.

Study of CT image texture using deep learning techniques

NASA Astrophysics Data System (ADS)

Dutta, Sandeep; Fan, Jiahua; Chevalier, David

2018-03-01

For CT imaging, reduction of radiation dose while improving or maintaining image quality (IQ) is currently a very active research and development topic. Iterative Reconstruction (IR) approaches have been suggested to be able to offer better IQ to dose ratio compared to the conventional Filtered Back Projection (FBP) reconstruction. However, it has been widely reported that often CT image texture from IR is different compared to that from FBP. Researchers have proposed different figure of metrics to quantitate the texture from different reconstruction methods. But there is still a lack of practical and robust method in the field for texture description. This work applied deep learning method for CT image texture study. Multiple dose scans of a 20cm diameter cylindrical water phantom was performed on Revolution CT scanner (GE Healthcare, Waukesha) and the images were reconstructed with FBP and four different IR reconstruction settings. The training images generated were randomly allotted (80:20) to a training and validation set. An independent test set of 256-512 images/class were collected with the same scan and reconstruction settings. Multiple deep learning (DL) networks with Convolution, RELU activation, max-pooling, fully-connected, global average pooling and softmax activation layers were investigated. Impact of different image patch size for training was investigated. Original pixel data as well as normalized image data were evaluated. DL models were reliably able to classify CT image texture with accuracy up to 99%. Results show that the deep learning techniques suggest that CT IR techniques may help lower the radiation dose compared to FBP.

Study of the performance of image restoration under different wavefront aberrations

NASA Astrophysics Data System (ADS)

Wang, Xinqiu; Hu, Xinqi

2016-10-01

Image restoration is an effective way to improve the quality of images degraded by wave-front aberrations. If the wave-front aberration is too large, the performance of the image restoration will not be good. In this paper, the relationship between the performance of image restoration and the degree of wave-front aberrations is studied. A set of different wave-front aberrations is constructed by Zernike polynomials, and the corresponding PSF under white-light illumination is calculated. A set of blurred images is then obtained through convolution methods. Next we recover the images with the regularized Richardson-Lucy algorithm and use the RMS of the original image and the homologous deblurred image to evaluate the quality of restoration. Consequently, we determine the range of wave-front errors in which the recovered images are acceptable.

Three-dimensional ultrasound imaging of the prostate

NASA Astrophysics Data System (ADS)

Fenster, Aaron; Downey, Donal B.

1999-05-01

Ultrasonography, a widely used imaging modality for the diagnosis and staging of many diseases, is an important cost- effective technique, however, technical improvements are necessary to realize its full potential. Two-dimensional viewing of 3D anatomy, using conventional ultrasonography, limits our ability to quantify and visualize most diseases, causing, in part, the reported variability in diagnosis and ultrasound guided therapy and surgery. This occurs because conventional ultrasound images are 2D, yet the anatomy is 3D; hence the diagnostician must integrate multiple images in his mind. This practice is inefficient, and may lead to operator variability and incorrect diagnoses. In addition, the 2D ultrasound image represents a single thin plane at some arbitrary angle in the body. It is difficult to localize and reproduce the image plane subsequently, making conventional ultrasonography unsatisfactory for follow-up studies and for monitoring therapy. Our efforts have focused on overcoming these deficiencies by developing 3D ultrasound imaging techniques that can acquire B-mode, color Doppler and power Doppler images. An inexpensive desktop computer is used to reconstruct the information in 3D, and then is also used for interactive viewing of the 3D images. We have used 3D ultrasound images for the diagnosis of prostate cancer, carotid disease, breast cancer and liver disease and for applications in obstetrics and gynecology. In addition, we have also used 3D ultrasonography for image-guided minimally invasive therapeutic applications of the prostate such as cryotherapy and brachytherapy.

Improving ovarian cancer imaging with LHRH-NBs: an experimental study.

PubMed

Li, Wenjuan; Zhang, Lingping; Zhu, Yuanfang; Zhang, Jinyi; Shen, Li; Huang, Shuying; Fang, Shanyu

2016-09-01

Our previous study used freeze-drying and biotin-avidin binding methods and obtained nontargeted nanobubbles (N-NBs) and ovarian cancer-targeting nanobubbles (LHRH-NBs, luteinizing hormone-releasing hormone nanobubbles). Our study also identified the physical and chemical properties of these two contrast agents, and validated the targeting ability and underlying mechanisms of LHRH-NBs in vitro. The present study investigated the imaging of N-NBs and LHRH-NBs in nude mice and their binding with tissues. The nude mice models of xenografts were divided into three groups, N-NB, LHRH-NB, and SonoVue. These contrast agents were injected via the caudal vein to observe the imaging of ovarian cancer. Fluorescence microscope was used to observe the penetration of N-NBs and LHRH-NBs through the vascular endothelial gaps. Immunofluorescence was used to observe the penetration of N-NBs and LHRH-NBs through vascular endothelial gaps and binding to the tumor cells. The imaging intensity and duration were not significantly different between N-NBs and LHRH-NBs. The imaging intensity in the N-NB and LHRH-NB groups was not significantly different compared with the SonoVue group; however, the imaging duration in the N-NB and LHRH-NB groups was significantly longer than in the SonoVue group (P < 0.001). Both N-NBs and LHRH-NBs penetrated through the vascular endothelial gaps. After penetrating through the vascular endothelial gapes, LHRH-NBs could target and bind to the tumor cells. N-NBs and LHRH-NBs are of good imaging effectiveness and relatively long imaging duration. LHRH-NB is a potent contrast agent for imaging ovarian cancer, while achieving targeted delivery of drugs to the site of ovarian cancer.

The Norwegian healthy body image programme: study protocol for a randomized controlled school-based intervention to promote positive body image and prevent disordered eating among Norwegian high school students.

PubMed

Sundgot-Borgen, Christine; Bratland-Sanda, Solfrid; Engen, Kethe M E; Pettersen, Gunn; Friborg, Oddgeir; Torstveit, Monica Klungland; Kolle, Elin; Piran, Niva; Sundgot-Borgen, Jorunn; Rosenvinge, Jan H

2018-03-06

Body dissatisfaction and disordered eating raise the risk for eating disorders. In the prevention of eating disorders, many programmes have proved partly successful in using cognitive techniques to combat such risk factors. However, specific strategies to actively promote a positive body image are rarely used. The present paper outlines a protocol for a programme integrating the promotion of a positive body image and the prevention of disordered eating. Using a cluster randomized controlled mixed methods design, 30 high schools and 2481 12th grade students were allocated to the Healthy Body Image programme or to a control condition. The intervention comprised three workshops, each of 90 min with the main themes body image, media literacy, and lifestyle. The intervention was interactive in nature, and were led by trained scientists. The outcome measures include standardized instruments administered pre-post intervention, and at 3 and 12 months follow-ups, respectively. Survey data cover feasibility and implementation issues. Qualitative interviews covers experiential data about students' benefits and satisfaction with the programme. The present study is one of the first in the body image and disordered eating literature that integrates a health promotion and a disease prevention approach, as well as integrating standardized outcome measures and experiential findings. Along with mediator and moderator analyses it is expected that the Healthy Body Image programme may prove its efficacy. If so, plans are made with respect to further dissemination as well as communicating the findings to regional and national decision makers in the education and health care services. The study was registered and released at ClinicalTrials.gov 21th August 2016 with the Clinical Trial.gov ID: PRSNCT02901457 . In addition, the study is approved by the Regional Committee for Medical and Health Research Ethics.

Modeling digital breast tomosynthesis imaging systems for optimization studies

NASA Astrophysics Data System (ADS)

Lau, Beverly Amy

Digital breast tomosynthesis (DBT) is a new imaging modality for breast imaging. In tomosynthesis, multiple images of the compressed breast are acquired at different angles, and the projection view images are reconstructed to yield images of slices through the breast. One of the main problems to be addressed in the development of DBT is the optimal parameter settings to obtain images ideal for detection of cancer. Since it would be unethical to irradiate women multiple times to explore potentially optimum geometries for tomosynthesis, it is ideal to use a computer simulation to generate projection images. Existing tomosynthesis models have modeled scatter and detector without accounting for oblique angles of incidence that tomosynthesis introduces. Moreover, these models frequently use geometry-specific physical factors measured from real systems, which severely limits the robustness of their algorithms for optimization. The goal of this dissertation was to design the framework for a computer simulation of tomosynthesis that would produce images that are sensitive to changes in acquisition parameters, so an optimization study would be feasible. A computer physics simulation of the tomosynthesis system was developed. The x-ray source was modeled as a polychromatic spectrum based on published spectral data, and inverse-square law was applied. Scatter was applied using a convolution method with angle-dependent scatter point spread functions (sPSFs), followed by scaling using an angle-dependent scatter-to-primary ratio (SPR). Monte Carlo simulations were used to generate sPSFs for a 5-cm breast with a 1-cm air gap. Detector effects were included through geometric propagation of the image onto layers of the detector, which were blurred using depth-dependent detector point-spread functions (PRFs). Depth-dependent PRFs were calculated every 5-microns through a 200-micron thick CsI detector using Monte Carlo simulations. Electronic noise was added as Gaussian noise as a

Evaluation method based on the image correlation for laser jamming image

NASA Astrophysics Data System (ADS)

Che, Jinxi; Li, Zhongmin; Gao, Bo

2013-09-01

The jamming effectiveness evaluation of infrared imaging system is an important part of electro-optical countermeasure. The infrared imaging devices in the military are widely used in the searching, tracking and guidance and so many other fields. At the same time, with the continuous development of laser technology, research of laser interference and damage effect developed continuously, laser has been used to disturbing the infrared imaging device. Therefore, the effect evaluation of the infrared imaging system by laser has become a meaningful problem to be solved. The information that the infrared imaging system ultimately present to the user is an image, so the evaluation on jamming effect can be made from the point of assessment of image quality. The image contains two aspects of the information, the light amplitude and light phase, so the image correlation can accurately perform the difference between the original image and disturbed image. In the paper, the evaluation method of digital image correlation, the assessment method of image quality based on Fourier transform, the estimate method of image quality based on error statistic and the evaluation method of based on peak signal noise ratio are analysed. In addition, the advantages and disadvantages of these methods are analysed. Moreover, the infrared disturbing images of the experiment result, in which the thermal infrared imager was interfered by laser, were analysed by using these methods. The results show that the methods can better reflect the jamming effects of the infrared imaging system by laser. Furthermore, there is good consistence between evaluation results by using the methods and the results of subjective visual evaluation. And it also provides well repeatability and convenient quantitative analysis. The feasibility of the methods to evaluate the jamming effect was proved. It has some extent reference value for the studying and developing on electro-optical countermeasures equipments and

Additional EIPC Study Analysis. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hadley, Stanton W; Gotham, Douglas J.; Luciani, Ralph L.

Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations weremore » developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 14 topics was developed for further analysis. This paper brings together the earlier interim reports of the first 13 topics plus one additional topic into a single final report.« less

Image ratio features for facial expression recognition application.

PubMed

Song, Mingli; Tao, Dacheng; Liu, Zicheng; Li, Xuelong; Zhou, Mengchu

2010-06-01

Video-based facial expression recognition is a challenging problem in computer vision and human-computer interaction. To target this problem, texture features have been extracted and widely used, because they can capture image intensity changes raised by skin deformation. However, existing texture features encounter problems with albedo and lighting variations. To solve both problems, we propose a new texture feature called image ratio features. Compared with previously proposed texture features, e.g., high gradient component features, image ratio features are more robust to albedo and lighting variations. In addition, to further improve facial expression recognition accuracy based on image ratio features, we combine image ratio features with facial animation parameters (FAPs), which describe the geometric motions of facial feature points. The performance evaluation is based on the Carnegie Mellon University Cohn-Kanade database, our own database, and the Japanese Female Facial Expression database. Experimental results show that the proposed image ratio feature is more robust to albedo and lighting variations, and the combination of image ratio features and FAPs outperforms each feature alone. In addition, we study asymmetric facial expressions based on our own facial expression database and demonstrate the superior performance of our combined expression recognition system.

Outer planet Pioneer imaging communications system study. [data compression

NASA Technical Reports Server (NTRS)

1974-01-01

The effects of different types of imaging data compression on the elements of the Pioneer end-to-end data system were studied for three imaging transmission methods. These were: no data compression, moderate data compression, and the advanced imaging communications system. It is concluded that: (1) the value of data compression is inversely related to the downlink telemetry bit rate; (2) the rolling characteristics of the spacecraft limit the selection of data compression ratios; and (3) data compression might be used to perform acceptable outer planet mission at reduced downlink telemetry bit rates.

[The future of bedside chest radiography: Comparative study of mobile flat-panels and needle-image plate storage phosphor systems].

PubMed

Bremicker, K; Gosch, D; Kahn, T; Borte, G

2015-11-01

Chest radiography is the most common diagnostic modality in intensive care units with new mobile flat-panels gaining more attention and availability in addition to the already used storage phosphor plates. Comparison of the image quality of mobile flat-panels and needle-image plate storage phosphor system in terms of bedside chest radiography. Retrospective analysis of 84 bedside chest radiographs of 42 intensive care patients (20 women, 22 men, average age: 65 years). All images were acquired during daily routine. For each patient, two images were analyzed, one from each system mentioned above. Two blinded radiologists evaluated the image quality based on ten criteria (e.g., diaphragm, heart contour, tracheal bifurcation, thoracic spine, lung structure, consolidations, foreign material, and overall impression) using a 5-point visibility scale (1 = excellent, 5 = not usable). There was no significant difference between the image quality of the two systems (p < 0.05). Overall some anatomical structures such as the diaphragm, heart, pulmonary consolidations and foreign material were considered of higher diagnostic quality compared to others, e.g., tracheal bifurcation and thoracic spine. Mobile flat-panels achieve an image quality which is as good as those of needle-image plate storage phosphor systems. In addition, they allow immediate evaluation of the image quality but in return are much more expensive in terms of purchase and maintenance.

Additive diagnostic role of imaging in glaucoma: optical coherence tomography and retinal nerve fiber layer photography.

PubMed

Kim, Ko Eun; Kim, Seok Hwan; Oh, Sohee; Jeoung, Jin Wook; Suh, Min Hee; Seo, Je Hyun; Kim, Martha; Park, Ki Ho; Kim, Dong Myung

2014-11-20

To investigate the additive diagnostic role of spectral-domain optical coherence tomography (SD-OCT) and red-free retinal nerve fiber layer photography (RNFLP) in making clinical glaucoma diagnosis. Four diagnostic combination sets, including the most recent image from each measurement of 196 glaucoma eyes (including the 44 preperimetric glaucoma eyes) and 101 healthy eyes, were prepared: (1) stereo disc photography and Humphrey visual field (SH), (2) SH and SD-OCT (SHO), (3) SH and RNFLP (SHR), and (4) SHR and SD-OCT (SHRO). Each randomly sorted set was serially presented at 1-month intervals to five glaucoma specialists who were asked to evaluate them in a subjective and independent manner. The specialists' glaucoma-diagnostic performances based on the sets were then compared. For each specialist, adding SD-OCT to SH or SHR increased the glaucoma-diagnostic sensitivity but not to a level of statistical significance. For one specialist, adding RNFLP to SH significantly increased the sensitivity. Each specialist showed a high level of specificity regardless of the diagnostic set. The overall sensitivity of all specialists' assessments was significantly increased by adding RNFLP or the combination of SD-OCT and RNFLP to SH (P < 0.001); however, adding SD-OCT to SH or SHR did not significantly increase the sensitivity. A similar relationship was noted also for the preperimetric glaucoma subgroup. In contrast to RNFLP, SD-OCT did not significantly enhance the diagnostic accuracy of detecting glaucoma or even of preperimetric glaucoma. Our results suggest that, at least for glaucoma specialists, the additive diagnostic role of OCT is limited. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Enhancing studies of the connectome in autism using the autism brain imaging data exchange II

PubMed Central

Di Martino, Adriana; O’Connor, David; Chen, Bosi; Alaerts, Kaat; Anderson, Jeffrey S.; Assaf, Michal; Balsters, Joshua H.; Baxter, Leslie; Beggiato, Anita; Bernaerts, Sylvie; Blanken, Laura M. E.; Bookheimer, Susan Y.; Braden, B. Blair; Byrge, Lisa; Castellanos, F. Xavier; Dapretto, Mirella; Delorme, Richard; Fair, Damien A.; Fishman, Inna; Fitzgerald, Jacqueline; Gallagher, Louise; Keehn, R. Joanne Jao; Kennedy, Daniel P.; Lainhart, Janet E.; Luna, Beatriz; Mostofsky, Stewart H.; Müller, Ralph-Axel; Nebel, Mary Beth; Nigg, Joel T.; O’Hearn, Kirsten; Solomon, Marjorie; Toro, Roberto; Vaidya, Chandan J.; Wenderoth, Nicole; White, Tonya; Craddock, R. Cameron; Lord, Catherine; Leventhal, Bennett; Milham, Michael P.

2017-01-01

The second iteration of the Autism Brain Imaging Data Exchange (ABIDE II) aims to enhance the scope of brain connectomics research in Autism Spectrum Disorder (ASD). Consistent with the initial ABIDE effort (ABIDE I), that released 1112 datasets in 2012, this new multisite open-data resource is an aggregate of resting state functional magnetic resonance imaging (MRI) and corresponding structural MRI and phenotypic datasets. ABIDE II includes datasets from an additional 487 individuals with ASD and 557 controls previously collected across 16 international institutions. The combination of ABIDE I and ABIDE II provides investigators with 2156 unique cross-sectional datasets allowing selection of samples for discovery and/or replication. This sample size can also facilitate the identification of neurobiological subgroups, as well as preliminary examinations of sex differences in ASD. Additionally, ABIDE II includes a range of psychiatric variables to inform our understanding of the neural correlates of co-occurring psychopathology; 284 diffusion imaging datasets are also included. It is anticipated that these enhancements will contribute to unraveling key sources of ASD heterogeneity. PMID:28291247

Diffusion-weighted imaging of the breast: principles and clinical applications.

PubMed

Woodhams, Reiko; Ramadan, Saadallah; Stanwell, Peter; Sakamoto, Satoko; Hata, Hirofumi; Ozaki, Masanori; Kan, Shinichi; Inoue, Yusuke

2011-01-01

Diffusion-weighted imaging provides a novel contrast mechanism in magnetic resonance (MR) imaging and has a high sensitivity in the detection of changes in the local biologic environment. A significant advantage of diffusion-weighted MR imaging over conventional contrast material-enhanced MR imaging is its high sensitivity to change in the microscopic cellular environment without the need for intravenous contrast material injection. Approaches to the assessment of diffusion-weighted breast imaging findings include assessment of these data alone and interpretation of the data in conjunction with T2-weighted imaging findings. In addition, the analysis of apparent diffusion coefficient (ADC) value can be undertaken either in isolation or in combination with diffusion-weighted and T2-weighted imaging. Most previous studies have evaluated ADC value alone; however, overlap in the ADC values of malignant and benign disease has been observed. This overlap may be partly due to selection of b value, which can influence the concomitant effect of perfusion and emphasize the contribution of multicomponent model influences. The simultaneous assessment of diffusion-weighted and T2-weighted imaging data and ADC value has the potential to improve specificity. In addition, the use of diffusion-weighted imaging in a standard breast MR imaging protocol may heighten sensitivity and thereby improve diagnostic accuracy. Standardization of diffusion-weighted imaging parameters is needed to allow comparison of multicenter studies and assessment of the clinical utility of diffusion-weighted imaging and ADC values in breast evaluation.

Sensor image prediction techniques

NASA Astrophysics Data System (ADS)

Stenger, A. J.; Stone, W. R.; Berry, L.; Murray, T. J.

1981-02-01

The preparation of prediction imagery is a complex, costly, and time consuming process. Image prediction systems which produce a detailed replica of the image area require the extensive Defense Mapping Agency data base. The purpose of this study was to analyze the use of image predictions in order to determine whether a reduced set of more compact image features contains enough information to produce acceptable navigator performance. A job analysis of the navigator's mission tasks was performed. It showed that the cognitive and perceptual tasks he performs during navigation are identical to those performed for the targeting mission function. In addition, the results of the analysis of his performance when using a particular sensor can be extended to the analysis of this mission tasks using any sensor. An experimental approach was used to determine the relationship between navigator performance and the type of amount of information in the prediction image. A number of subjects were given image predictions containing varying levels of scene detail and different image features, and then asked to identify the predicted targets in corresponding dynamic flight sequences over scenes of cultural, terrain, and mixed (both cultural and terrain) content.

High resolution radio imaging study of the Pulsar Wind Nebula MSH 15-52

NASA Astrophysics Data System (ADS)

Leung, W.-Y.; Ng, C.-Y.

2016-06-01

We present a new high-resolution radio imaging study of the pulsar wind nebula (PWN) MSH 15-52, also dubbed as "the hand of God", with the Australia Telescope Compact Array observations. The system is powered by a young and energetic radio pulsar B1509-58 with high spin down luminosity of E(dot) = 2 x 10^37 erg/s. Previous X-ray images have shown that the PWN has a complex hand-shape morphology extending over 10 pc with features like jets, arc, filaments and enhanced emission knots in the HII region RCW 89. The new 6cm and 3cm radio images show different morphology than the X-ray counterpart. No radio counterpart of the X-ray jet is detected, instead we found enhanced emission in a sheath surrounding the jet. Additional small-scale features including a polarized linear filament next to the pulsar have also been discovered. Our polarisation measurements show that the intrinsic orientation of magnetic field aligns with the sheath. Finally, spectral analysis results indicate a steep spectrum for the system, which is rather unusual among PWNe. Implications of these findings will be discussed. The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. This work is supported by an ECS grant under HKU 709713P.

Four-Photon Imaging with Thermal Light

NASA Astrophysics Data System (ADS)

Wen, Feng; Xue, Xinxin; Zhang, Xun; Yuan, Chenzhi; Sun, Jia; Song, Jianping; Zhang, Yanpeng

2014-10-01

In a near-field four-photon correlation measurement, ghost imaging with classical incoherent light is investigated. By applying the Klyshko advanced-wave picture, we consider the properties of four-photon spatial correlation and find that the fourth-order spatial correlation function can be decomposed into multiple lower-order correlation functions. On the basis of the spatial correlation properties, a proof-of-principle four-photon ghost imaging is proposed, and the effect of each part in a fourth-order correlation function on imaging is also analyzed. In addition, the similarities and differences among ghost imaging by fourth-, second-, and third-order correlations are also discussed. It is shown that the contrast and visibility of fourth-order correlated imaging are improved significantly, while the resolution is unchanged. Such studies can be very useful in better understanding multi photon interference and multi-channel correlation imaging.

Distance preservation in color image transforms

NASA Astrophysics Data System (ADS)

Santini, Simone

1999-12-01

Most current image processing systems work on color images, and color is a precious perceptual clue for determining image similarity. Working with color images, however, is not the sam thing as working with images taking values in a 3D Euclidean space. Not only are color spaces bounded, but the characteristics of the observer endow the space with a 'perceptual' metric that in general does not correspond to the metric naturally inherited from R3. This paper studies the problem of filtering color images abstractly. It begins by determining the properties of the color sum and color product operations such that he desirable properties of orthonormal bases will be preserved. The paper then defines a general scheme, based on the action of the additive group on the color space, by which operations that satisfy the required properties can be defined.

Study on imaging spectrometer with smile and keystone eliminated

NASA Astrophysics Data System (ADS)

Zhang, Xiaolong; Yu, Kun; Zhang, Jun

2017-03-01

The formulas of image height in two-dimensional field about Gaussian and tilted imaging system of grating-based imaging spectrometer instrument (GISI) are deduced firstly, and the determined expressions of smile and keystone of GISI are obtained. It is proposed to correct the smile with off-axis lens, and the elimination effect of the smile is studied by means of spatial ray tracing. By controlling the degree of off-axis and the distribution of focal power of the off-axis lens, the long-wave infrared imaging spectrometer with well-eliminated smile and keystone is designed. The maximum of smile and keystone at working wavelengths in all fields of view are less than 8.57 μm and 13.33 μm, respectively.

Geometry planning and image registration in magnetic particle imaging using bimodal fiducial markers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werner, F., E-mail: f.werner@uke.de; Hofmann, M.; Them, K.

Purpose: Magnetic particle imaging (MPI) is a quantitative imaging modality that allows the distribution of superparamagnetic nanoparticles to be visualized. Compared to other imaging techniques like x-ray radiography, computed tomography (CT), and magnetic resonance imaging (MRI), MPI only provides a signal from the administered tracer, but no additional morphological information, which complicates geometry planning and the interpretation of MP images. The purpose of the authors’ study was to develop bimodal fiducial markers that can be visualized by MPI and MRI in order to create MP–MR fusion images. Methods: A certain arrangement of three bimodal fiducial markers was developed and usedmore » in a combined MRI/MPI phantom and also during in vivo experiments in order to investigate its suitability for geometry planning and image fusion. An algorithm for automated marker extraction in both MR and MP images and rigid registration was established. Results: The developed bimodal fiducial markers can be visualized by MRI and MPI and allow for geometry planning as well as automated registration and fusion of MR–MP images. Conclusions: To date, exact positioning of the object to be imaged within the field of view (FOV) and the assignment of reconstructed MPI signals to corresponding morphological regions has been difficult. The developed bimodal fiducial markers and the automated image registration algorithm help to overcome these difficulties.« less

Photoacoustic image patterns of breast carcinoma and comparisons with Magnetic Resonance Imaging and vascular stained histopathology

NASA Astrophysics Data System (ADS)

Heijblom, M.; Piras, D.; Brinkhuis, M.; van Hespen, J. C. G.; van den Engh, F. M.; van der Schaaf, M.; Klaase, J. M.; van Leeuwen, T. G.; Steenbergen, W.; Manohar, S.

2015-07-01

Photoacoustic (optoacoustic) imaging can visualize vasculature deep in tissue using the high contrast of hemoglobin to light, with the high-resolution possible with ultrasound detection. Since angiogenesis, one of the hallmarks of cancer, leads to increased vascularity, photoacoustics holds promise in imaging breast cancer as shown in proof-of-principle studies. Here for the first time, we investigate if there are specific photoacoustic appearances of breast malignancies which can be related to the tumor vascularity, using an upgraded research imaging system, the Twente Photoacoustic Mammoscope. In addition to comparisons with x-ray and ultrasound images, in subsets of cases the photoacoustic images were compared with MR images, and with vascular staining in histopathology. We were able to identify lesions in suspect breasts at the expected locations in 28 of 29 cases. We discovered generally three types of photoacoustic appearances reminiscent of contrast enhancement types reported in MR imaging of breast malignancies, and first insights were gained into the relationship with tumor vascularity.

Studies of EGRET sources with a novel image restoration technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tajima, Hiroyasu; Cohen-Tanugi, Johann; Kamae, Tuneyoshi

2007-07-12

We have developed an image restoration technique based on the Richardson-Lucy algorithm optimized for GLAST-LAT image analysis. Our algorithm is original since it utilizes the PSF (point spread function) that is calculated for each event. This is critical for EGRET and GLAST-LAT image analysis since the PSF depends on the energy and angle of incident gamma-rays and varies by more than one order of magnitude. EGRET and GLAST-LAT image analysis also faces Poisson noise due to low photon statistics. Our technique incorporates wavelet filtering to minimize noise effects. We present studies of EGRET sources using this novel image restoration techniquemore » for possible identification of extended gamma-ray sources.« less

Solid-phase synthesis of graphene quantum dots from the food additive citric acid under microwave irradiation and their use in live-cell imaging.

PubMed

Zhuang, Qianfen; Wang, Yong; Ni, Yongnian

2016-05-01

The work demonstrated that solid citric acid, one of the most common food additives, can be converted to graphene quantum dots (GQDs) under microwave heating. The as-prepared GQDs were further characterized by various analytical techniques like transmission electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, fluorescence and UV-visible spectroscopy. Cytotoxicity of the GQDs was evaluated using HeLa cells. The result showed that the GQDs almost did not exhibit cytotoxicity at concentrations as high as 1000 µg mL(-1). In addition, it was found that the GQDs showed good solubility, excellent photostability, and excitation-dependent multicolor photoluminescence. Subsequently, the multicolor GQDs were successfully used as a fluorescence light-up probe for live-cell imaging. Copyright © 2015 John Wiley & Sons, Ltd.

Imaging Tumor Cell Movement In Vivo

PubMed Central

Entenberg, David; Kedrin, Dmitriy; Wyckoff, Jeffrey; Sahai, Erik; Condeelis, John; Segall, Jeffrey E.

2013-01-01

This unit describes the methods that we have been developing for analyzing tumor cell motility in mouse and rat models of breast cancer metastasis. Rodents are commonly used both to provide a mammalian system for studying human tumor cells (as xenografts in immunocompromised mice) as well as for following the development of tumors from a specific tissue type in transgenic lines. The Basic Protocol in this unit describes the standard methods used for generation of mammary tumors and imaging them. Additional protocols for labeling macrophages, blood vessel imaging, and image analysis are also included. PMID:23456602

Study of Image Qualities From 6D Robot-Based CBCT Imaging System of Small Animal Irradiator.

PubMed

Sharma, Sunil; Narayanasamy, Ganesh; Clarkson, Richard; Chao, Ming; Moros, Eduardo G; Zhang, Xin; Yan, Yulong; Boerma, Marjan; Paudel, Nava; Morrill, Steven; Corry, Peter; Griffin, Robert J

2017-01-01

To assess the quality of cone beam computed tomography images obtained by a robotic arm-based and image-guided small animal conformal radiation therapy device. The small animal conformal radiation therapy device is equipped with a 40 to 225 kV X-ray tube mounted on a custom made gantry, a 1024 × 1024 pixels flat panel detector (200 μm resolution), a programmable 6 degrees of freedom robot for cone beam computed tomography imaging and conformal delivery of radiation doses. A series of 2-dimensional radiographic projection images were recorded in cone beam mode by placing and rotating microcomputed tomography phantoms on the "palm' of the robotic arm. Reconstructed images were studied for image quality (spatial resolution, image uniformity, computed tomography number linearity, voxel noise, and artifacts). Geometric accuracy was measured to be 2% corresponding to 0.7 mm accuracy on a Shelley microcomputed tomography QA phantom. Qualitative resolution of reconstructed axial computed tomography slices using the resolution coils was within 200 μm. Quantitative spatial resolution was found to be 3.16 lp/mm. Uniformity of the system was measured within 34 Hounsfield unit on a QRM microcomputed tomography water phantom. Computed tomography numbers measured using the linearity plate were linear with material density ( R 2 > 0.995). Cone beam computed tomography images of the QRM multidisk phantom had minimal artifacts. Results showed that the small animal conformal radiation therapy device is capable of producing high-quality cone beam computed tomography images for precise and conformal small animal dose delivery. With its high-caliber imaging capabilities, the small animal conformal radiation therapy device is a powerful tool for small animal research.

Making intelligent systems team players: Additional case studies

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Schreckenghost, Debra L.; Rhoads, Ron W.

1993-01-01

Observations from a case study of intelligent systems are reported as part of a multi-year interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. A series of studies were conducted to investigate issues in designing intelligent fault management systems in aerospace applications for effective human-computer interaction. The results of the initial study are documented in two NASA technical memoranda: TM 104738 Making Intelligent Systems Team Players: Case Studies and Design Issues, Volumes 1 and 2; and TM 104751, Making Intelligent Systems Team Players: Overview for Designers. The objective of this additional study was to broaden the investigation of human-computer interaction design issues beyond the focus on monitoring and fault detection in the initial study. The results of this second study are documented which is intended as a supplement to the original design guidance documents. These results should be of interest to designers of intelligent systems for use in real-time operations, and to researchers in the areas of human-computer interaction and artificial intelligence.

Real-time hyperspectral fluorescence imaging of pancreatic β-cell dynamics with the image mapping spectrometer

PubMed Central

Elliott, Amicia D.; Gao, Liang; Ustione, Alessandro; Bedard, Noah; Kester, Robert; Piston, David W.; Tkaczyk, Tomasz S.

2012-01-01

Summary The development of multi-colored fluorescent proteins, nanocrystals and organic fluorophores, along with the resulting engineered biosensors, has revolutionized the study of protein localization and dynamics in living cells. Hyperspectral imaging has proven to be a useful approach for such studies, but this technique is often limited by low signal and insufficient temporal resolution. Here, we present an implementation of a snapshot hyperspectral imaging device, the image mapping spectrometer (IMS), which acquires full spectral information simultaneously from each pixel in the field without scanning. The IMS is capable of real-time signal capture from multiple fluorophores with high collection efficiency (∼65%) and image acquisition rate (up to 7.2 fps). To demonstrate the capabilities of the IMS in cellular applications, we have combined fluorescent protein (FP)-FRET and [Ca2+]i biosensors to measure simultaneously intracellular cAMP and [Ca2+]i signaling in pancreatic β-cells. Additionally, we have compared quantitatively the IMS detection efficiency with a laser-scanning confocal microscope. PMID:22854044

Near Infrared Imaging As a Method of Studying Tsetse Fly (Diptera: Glossinidae) Pupal Development

PubMed Central

Moran, Zelda R.; Parker, Andrew G.

2016-01-01

Abstract Near infrared (NIR) photography and video was investigated as a method for observing and recording intrapuparial development in the tsetse fly Glossina palpalis gambiensis and other Muscomorpha (Cyclorrhapha) Diptera. We showed that NIR light passes through the puparium, permitting images of the true pupae and pharate adult to be captured. Various wavelengths of NIR light from 880 to 1060 nm were compared to study the development of tsetse fly pupae from larviposition to emergence, using time-lapse videos and photographs. This study was carried out to advance our understanding of tsetse pupal development, specifically with the goal of improving a sorting technique which could separate male from female tsetse flies several days before emergence. Separation of the sexes at this stage is highly desirable for operational tsetse sterile insect technique control programmes, as it would permit the easy retention of females for the colony while allowing the males to be handled, irradiated and shipped in the pupal stage when they are less sensitive to vibration. In addition, it presents a new methodology for studying the pupal stage of many coarctate insects for many applications. NIR imaging permits observation of living pupae, allowing the entire development process to be observed without disruption. PMID:27402791

Neural Responses to Visual Food Cues According to Weight Status: A Systematic Review of Functional Magnetic Resonance Imaging Studies

PubMed Central

Pursey, Kirrilly M.; Stanwell, Peter; Callister, Robert J.; Brain, Katherine; Collins, Clare E.; Burrows, Tracy L.

2014-01-01

Emerging evidence from recent neuroimaging studies suggests that specific food-related behaviors contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI), in humans of differing weight status. Published studies to 2014 were retrieved and included if they used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies were identified that investigated the neural responses of healthy weight participants (n = 26), healthy weight compared to obese participants (n = 17), and weight-loss interventions (n = 12). High-calorie food images were used in the majority of studies (n = 36), however, image selection justification was only provided in 19 studies. Obese individuals had increased activation of reward-related brain areas including the insula and orbitofrontal cortex in response to visual food cues compared to healthy weight individuals, and this was particularly evident in response to energy dense cues. Additionally, obese individuals were more responsive to food images when satiated. Meta-analysis of changes in neural activation post-weight loss revealed small areas of convergence across studies in brain areas related to emotion, memory, and learning, including the cingulate gyrus, lentiform nucleus, and precuneus. Differential activation patterns to visual food cues were observed between obese, healthy weight, and weight-loss populations. Future studies require standardization of nutrition variables and fMRI outcomes to enable more direct comparisons between studies. PMID:25988110

Neural responses to visual food cues according to weight status: a systematic review of functional magnetic resonance imaging studies.

PubMed

Pursey, Kirrilly M; Stanwell, Peter; Callister, Robert J; Brain, Katherine; Collins, Clare E; Burrows, Tracy L

2014-01-01

Emerging evidence from recent neuroimaging studies suggests that specific food-related behaviors contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI), in humans of differing weight status. Published studies to 2014 were retrieved and included if they used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies were identified that investigated the neural responses of healthy weight participants (n = 26), healthy weight compared to obese participants (n = 17), and weight-loss interventions (n = 12). High-calorie food images were used in the majority of studies (n = 36), however, image selection justification was only provided in 19 studies. Obese individuals had increased activation of reward-related brain areas including the insula and orbitofrontal cortex in response to visual food cues compared to healthy weight individuals, and this was particularly evident in response to energy dense cues. Additionally, obese individuals were more responsive to food images when satiated. Meta-analysis of changes in neural activation post-weight loss revealed small areas of convergence across studies in brain areas related to emotion, memory, and learning, including the cingulate gyrus, lentiform nucleus, and precuneus. Differential activation patterns to visual food cues were observed between obese, healthy weight, and weight-loss populations. Future studies require standardization of nutrition variables and fMRI outcomes to enable more direct comparisons between studies.

An initial study on the estimation of time-varying volumetric treatment images and 3D tumor localization from single MV cine EPID images

PubMed Central

Mishra, Pankaj; Li, Ruijiang; Mak, Raymond H.; Rottmann, Joerg; Bryant, Jonathan H.; Williams, Christopher L.; Berbeco, Ross I.; Lewis, John H.

2014-01-01

. This is the first method to estimate volumetric time-varying images from single MV cine EPID images, and has the potential to provide volumetric information with no additional imaging dose to the patient. PMID:25086523

An initial study on the estimation of time-varying volumetric treatment images and 3D tumor localization from single MV cine EPID images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Pankaj, E-mail: pankaj.mishra@varian.com; Mak, Raymond H.; Rottmann, Joerg

2014-08-15

motion model. This is the first method to estimate volumetric time-varying images from single MV cine EPID images, and has the potential to provide volumetric information with no additional imaging dose to the patient.« less

How do you define body image? Exploring conceptual gaps in understandings of body image at an exercise facility.

PubMed

Bailey, K Alysse; Gammage, Kimberley L; van Ingen, Cathy

2017-12-01

The definition of body image has evolved within research; however, less is known about the layperson's understanding of the construct. This study explored how members and student trainees of an exercise facility (designed for older adults, people with physical disability, and those with cardiac complications) defined body image. Nineteen participants completed a one-on-one interview, and seven of those participants took part in six additional focus group meetings. The following main themes were found: stereotypical assumptions about body image (e.g., it is solely a person's weight or merely a woman's issue), body image continua for positive and negative body image, degree of complexity of body image dimensions, broad considerations of body image (e.g., it is self-esteem), and limited knowledge about body image. These findings suggest a need for knowledge translation between researchers and the general public which informs future body image program design. Copyright © 2017 Elsevier Ltd. All rights reserved.

Feasibility study on an integrated AEC-grid device for the optimization of image quality and exposure dose in mammography

NASA Astrophysics Data System (ADS)

Kim, Kyo-Tae; Yun, Ryang-Young; Han, Moo-Jae; Heo, Ye-Ji; Song, Yong-Keun; Heo, Sung-Wook; Oh, Kyeong-Min; Park, Sung-Kwang

2017-10-01

Currently, in the radiation diagnosis field, mammography is used for the early detection of breast cancer. In addition, studies are being conducted on a grid to produce high-quality images. Although the grid ratio of the grid, which affects the scattering removal rate, must be increased to improve image quality, it increases the total exposure dose. While the use of automatic exposure control is recommended to minimize this problem, existing mammography equipment, unlike general radiography equipment, is mounted on the back of a detector. Therefore, the device is greatly affected by the detector and supporting device, and it is difficult to control the exposure dose. Accordingly, in this research, an integrated AEC-grid device that simultaneously performs AEC and grid functions was used to minimize the unnecessary exposure dose while removing scattering, thereby realizing superior image quality.

A theory of phase singularities for image representation and its applications to object tracking and image matching.

PubMed

Qiao, Yu; Wang, Wei; Minematsu, Nobuaki; Liu, Jianzhuang; Takeda, Mitsuo; Tang, Xiaoou

2009-10-01

This paper studies phase singularities (PSs) for image representation. We show that PSs calculated with Laguerre-Gauss filters contain important information and provide a useful tool for image analysis. PSs are invariant to image translation and rotation. We introduce several invariant features to characterize the core structures around PSs and analyze the stability of PSs to noise addition and scale change. We also study the characteristics of PSs in a scale space, which lead to a method to select key scales along phase singularity curves. We demonstrate two applications of PSs: object tracking and image matching. In object tracking, we use the iterative closest point algorithm to determine the correspondences of PSs between two adjacent frames. The use of PSs allows us to precisely determine the motions of tracked objects. In image matching, we combine PSs and scale-invariant feature transform (SIFT) descriptor to deal with the variations between two images and examine the proposed method on a benchmark database. The results indicate that our method can find more correct matching pairs with higher repeatability rates than some well-known methods.

SEMIPARAMETRIC ADDITIVE RISKS REGRESSION FOR TWO-STAGE DESIGN SURVIVAL STUDIES

PubMed Central

Li, Gang; Wu, Tong Tong

2011-01-01

In this article we study a semiparametric additive risks model (McKeague and Sasieni (1994)) for two-stage design survival data where accurate information is available only on second stage subjects, a subset of the first stage study. We derive two-stage estimators by combining data from both stages. Large sample inferences are developed. As a by-product, we also obtain asymptotic properties of the single stage estimators of McKeague and Sasieni (1994) when the semiparametric additive risks model is misspecified. The proposed two-stage estimators are shown to be asymptotically more efficient than the second stage estimators. They also demonstrate smaller bias and variance for finite samples. The developed methods are illustrated using small intestine cancer data from the SEER (Surveillance, Epidemiology, and End Results) Program. PMID:21931467

Does use of a PACS increase the number of images per study? A case study in ultrasound.

PubMed

Horii, Steven; Nisenbaum, Harvey; Farn, James; Coleman, Beverly; Rowling, Susan; Langer, Jill; Jacobs, Jill; Arger, Peter; Pinheiro, Lisa; Klein, Wendy; Reber, Michele; Iyoob, Christopher

2002-03-01

The purpose of this study was to determine if the use of a picture archiving and communications system (PACS) in ultrasonography increased the number of images acquired per examination. The hypothesis that such an increase does occur was based on anecdotal information; this study sought to test the hypothesis. A random sample of all ultrasound examination types was drawn from the period 1998 through 1999. The ultrasound PACS in use (ACCESS; Kodak Health Information Systems, Dallas, TX) records the number of grayscale and color images saved as part of each study. Each examination in the sample was checked in the ultrasound PACS database,.and the number of grayscale and color images was recorded. The comparison film-based sample was drawn from the period 1994 through 1995. The number of examinations of each type selected was based on the overall statistics of the section; that is, the sample was designed to represent the approximate frequency with which the various examination types are done. For film-based image counts, the jackets were retrieved, and the number of grayscale and color images were counted. The number of images obtained per examination (for most examinations) in ultrasound increased with PACS use. This was more evident with some examination types (eg, pelvis). This result, however, has to be examined for possible systematic biases because ultrasound practice has changed over the time since the authors stopped using film routinely. The use of PACS in ultrasonography was not associated with an increase in the number of images per examination based solely on the use of PACS, with the exception of neonatal head studies. Increases in the number of images per study was otherwise associated with examinations for which changes in protocols resulted in the increased image counts.

Optical image hiding based on computational ghost imaging

NASA Astrophysics Data System (ADS)

Wang, Le; Zhao, Shengmei; Cheng, Weiwen; Gong, Longyan; Chen, Hanwu

2016-05-01

Imaging hiding schemes play important roles in now big data times. They provide copyright protections of digital images. In the paper, we propose a novel image hiding scheme based on computational ghost imaging to have strong robustness and high security. The watermark is encrypted with the configuration of a computational ghost imaging system, and the random speckle patterns compose a secret key. Least significant bit algorithm is adopted to embed the watermark and both the second-order correlation algorithm and the compressed sensing (CS) algorithm are used to extract the watermark. The experimental and simulation results show that the authorized users can get the watermark with the secret key. The watermark image could not be retrieved when the eavesdropping ratio is less than 45% with the second-order correlation algorithm, whereas it is less than 20% with the TVAL3 CS reconstructed algorithm. In addition, the proposed scheme is robust against the 'salt and pepper' noise and image cropping degradations.

Advanced imaging techniques for the study of plant growth and development.

PubMed

Sozzani, Rosangela; Busch, Wolfgang; Spalding, Edgar P; Benfey, Philip N

2014-05-01

A variety of imaging methodologies are being used to collect data for quantitative studies of plant growth and development from living plants. Multi-level data, from macroscopic to molecular, and from weeks to seconds, can be acquired. Furthermore, advances in parallelized and automated image acquisition enable the throughput to capture images from large populations of plants under specific growth conditions. Image-processing capabilities allow for 3D or 4D reconstruction of image data and automated quantification of biological features. These advances facilitate the integration of imaging data with genome-wide molecular data to enable systems-level modeling. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Survey of Image Encryption Algorithms

NASA Astrophysics Data System (ADS)

Kumari, Manju; Gupta, Shailender; Sardana, Pranshul

2017-12-01

Security of data/images is one of the crucial aspects in the gigantic and still expanding domain of digital transfer. Encryption of images is one of the well known mechanisms to preserve confidentiality of images over a reliable unrestricted public media. This medium is vulnerable to attacks and hence efficient encryption algorithms are necessity for secure data transfer. Various techniques have been proposed in literature till date, each have an edge over the other, to catch-up to the ever growing need of security. This paper is an effort to compare the most popular techniques available on the basis of various performance metrics like differential, statistical and quantitative attacks analysis. To measure the efficacy, all the modern and grown-up techniques are implemented in MATLAB-2015. The results show that the chaotic schemes used in the study provide highly scrambled encrypted images having uniform histogram distribution. In addition, the encrypted images provided very less degree of correlation coefficient values in horizontal, vertical and diagonal directions, proving their resistance against statistical attacks. In addition, these schemes are able to resist differential attacks as these showed a high sensitivity for the initial conditions, i.e. pixel and key values. Finally, the schemes provide a large key spacing, hence can resist the brute force attacks, and provided a very less computational time for image encryption/decryption in comparison to other schemes available in literature.

Study of quality perception in medical images based on comparison of contrast enhancement techniques in mammographic images

NASA Astrophysics Data System (ADS)

Matheus, B.; Verçosa, L. B.; Barufaldi, B.; Schiabel, H.

2014-03-01

With the absolute prevalence of digital images in mammography several new tools became available for radiologist; such as CAD schemes, digital zoom and contrast alteration. This work focuses in contrast variation and how the radiologist reacts to these changes when asked to evaluated image quality. Three contrast enhancing techniques were used in this study: conventional equalization, CCB Correction [1] - a digitization correction - and value subtraction. A set of 100 images was used in tests from some available online mammographic databases. The tests consisted of the presentation of all four versions of an image (original plus the three contrast enhanced images) to the specialist, requested to rank each one from the best up to worst quality for diagnosis. Analysis of results has demonstrated that CCB Correction [1] produced better images in almost all cases. Equalization, which mathematically produces a better contrast, was considered the worst for mammography image quality enhancement in the majority of cases (69.7%). The value subtraction procedure produced images considered better than the original in 84% of cases. Tests indicate that, for the radiologist's perception, it seems more important to guaranty full visualization of nuances than a high contrast image. Another result observed is that the "ideal" scanner curve does not yield the best result for a mammographic image. The important contrast range is the middle of the histogram, where nodules and masses need to be seen and clearly distinguished.

The role of molecular imaging in diagnosis of deep vein thrombosis

PubMed Central

Houshmand, Sina; Salavati, Ali; Hess, Søren; Ravina, Mudalsha; Alavi, Abass

2014-01-01

Venous thromboembolism (VTE) mostly presenting as deep venous thrombosis (DVT) and pulmonary embolism (PE) affects up to 600,000 individuals in United States each year. Clinical symptoms of VTE are nonspecific and sometimes misleading. Additionally, side effects of available treatment plans for DVT are significant. Therefore, medical imaging plays a crucial role in proper diagnosis and avoidance from over/under diagnosis, which exposes the patient to risk. In addition to conventional structural imaging modalities, such as ultrasonography and computed tomography, molecular imaging with different tracers have been studied for diagnosis of DVT. In this review we will discuss currently available and newly evolving targets and tracers for detection of DVT using molecular imaging methods. PMID:25143860

Neutrons Image Additive Manufactured Turbine Blade in 3-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2016-04-29

The video displays the Inconel 718 Turbine Blade made by Additive Manufacturing. First a gray scale neutron computed tomogram (CT) is displayed with transparency in order to show the internal structure. Then the neutron CT is overlapped with the engineering drawing that was used to print the part and a comparison of external and internal structures is possible. This provides a map of the accuracy of the printed turbine (printing tolerance). Internal surface roughness can also be observed. Credits: Experimental Measurements: Hassina Z. Bilheaux, Video and Printing Tolerance Analysis: Jean C. Bilheaux

TH-CD-202-02: A Preliminary Study Evaluating Beam-Hardening Artifact Reduction On CT Direct Electron-Density Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, H; Dolly, S; Zhao, T

Purpose: A prototype reconstruction algorithm that can provide direct electron density (ED) images from single energy CT scans is being currently developed by Siemens Healthcare GmbH. This feature can eliminate the need for kV specific calibration curve for radiation treatemnt planning. An added benefit is that beam-hardening artifacts are also reduced on direct-ED images due to the underlying material decomposition. This study is to quantitatively analyze the reduction of beam-hardening artifacts on direct-ED images and suggest additional clinical usages. Methods: HU and direct-ED images were reconstructed on a head phantom scanned on a Siemens Definition AS CT scanner at fivemore » tube potentials of 70kV, 80kV, 100kV, 120kV and 140kV respectively. From these images, mean, standard deviation (SD), and local NPS were calculated for regions of interest (ROI) of same locations and sizes. A complete analysis of beam-hardening artifact reduction and image quality improvement was conducted. Results: Along with the increase of tube potentials, ROI means and SDs decrease on both HU and direct-ED images. The mean value differences between HU and direct-ED images are up to 8% with absolute value of 2.9. Compared to that on HU images, the SDs are lower on direct-ED images, and the differences are up to 26%. Interestingly, the local NPS calculated from direct-ED images shows consistent values in the low spatial frequency domain for images acquired from all tube potential settings, while varied dramatically on HU images. This also confirms the beam -hardening artifact reduction on ED images. Conclusions: The low SDs on direct-ED images and relative consistent NPS values in the low spatial frequency domain indicate a reduction of beam-hardening artifacts. The direct-ED image has the potential to assist in more accurate organ contouring, and is a better fit for the desired purpose of CT simulations for radiotherapy.« less

Fusion Imaging: A Novel Staging Modality in Testis Cancer

PubMed Central

Sterbis, Joseph R.; Rice, Kevin R.; Javitt, Marcia C.; Schenkman, Noah S.; Brassell, Stephen A.

2010-01-01

Objective: Computed tomography and chest radiographs provide the standard imaging for staging, treatment, and surveillance of testicular germ cell neoplasms. Positron emission tomography has recently been utilized for staging, but is somewhat limited in its ability to provide anatomic localization. Fusion imaging combines the metabolic information provided by positron emission tomography with the anatomic precision of computed tomography. To the best of our knowledge, this represents the first study of the effectiveness using fusion imaging in evaluation of patients with testis cancer. Methods: A prospective study of 49 patients presenting to Walter Reed Army Medical Center with testicular cancer from 2003 to 2009 was performed. Fusion imaging was compared with conventional imaging, tumor markers, pathologic results, and clinical follow-up. Results: There were 14 true positives, 33 true negatives, 1 false positive, and 1 false negative. Sensitivity, specificity, positive predictive value, and negative predictive value were 93.3, 97.0, 93.3, and 97.0% respectively. In 11 patient scenarios, fusion imaging differed from conventional imaging. Utility was found in superior lesion detection compared to helical computed tomography due to anatomical/functional image co-registration, detection of micrometastasis in lymph nodes (pathologic nodes < 1cm), surveillance for recurrence post-chemotherapy, differentiating fibrosis from active disease in nodes < 2.5cm, and acting as a quality assurance measure to computed tomography alone. Conclusions: In addition to demonstrating a sensitivity and specificity comparable or superior to conventional imaging, fusion imaging shows promise in providing additive data that may assist in clinical decision-making. PMID:21103077

Experimental study of a DMD based compressive line sensing imaging system in the turbulence environment

NASA Astrophysics Data System (ADS)

Ouyang, Bing; Hou, Weilin; Gong, Cuiling; Caimi, Frank M.; Dalgleish, Fraser R.; Vuorenkoski, Anni K.

2016-05-01

The Compressive Line Sensing (CLS) active imaging system has been demonstrated to be effective in scattering mediums, such as turbid coastal water through simulations and test tank experiments. Since turbulence is encountered in many atmospheric and underwater surveillance applications, a new CLS imaging prototype was developed to investigate the effectiveness of the CLS concept in a turbulence environment. Compared with earlier optical bench top prototype, the new system is significantly more robust and compact. A series of experiments were conducted at the Naval Research Lab's optical turbulence test facility with the imaging path subjected to various turbulence intensities. In addition to validating the system design, we obtained some unexpected exciting results - in the strong turbulence environment, the time-averaged measurements using the new CLS imaging prototype improved both SNR and resolution of the reconstructed images. We will discuss the implications of the new findings, the challenges of acquiring data through strong turbulence environment, and future enhancements.

Bibliography of geologic studies using imaging radar

NASA Technical Reports Server (NTRS)

Bryan, M. L.

1979-01-01

Articles concerning imaging studies on the geomorphology, mineralogy, and topology of various landforms are reported. One hundred and ninety citations are listed and an index by National Technical Information service citation number is included. Several illustrations of L-band radar imagery are presented.

Feasibility study of computed vs measured high b-value (1400 s/mm²) diffusion-weighted MR images of the prostate

PubMed Central

Bittencourt, Leonardo K; Attenberger, Ulrike I; Lima, Daniel; Strecker, Ralph; de Oliveira, Andre; Schoenberg, Stefan O; Gasparetto, Emerson L; Hausmann, Daniel

2014-01-01

AIM: To evaluate the impact of computed b = 1400 s/mm2 (C-b1400) vs measured b = 1400 s/mm2 (M-b1400) diffusion-weighted images (DWI) on lesion detection rate, image quality and quality of lesion demarcation using a modern 3T-MR system based on a small-field-of-view sequence (sFOV). METHODS: Thirty patients (PSA: 9.5 ± 8.7 ng/mL; 68 ± 12 years) referred for magnetic resonance imaging (MRI) of the prostate were enrolled in this study. All measurements were performed on a 3T MR system. For DWI, a single-shot EPI diffusion sequence (b = 0, 100, 400, 800 s/mm²) was utilized. C-b1400 was calculated voxelwise from the ADC and diffusion images. Additionally, M-b1400 was acquired for evaluation and comparison. Lesion detection rate and maximum lesion diameters were obtained and compared. Image quality and quality of lesion demarcation were rated according to a 5-point Likert-type scale. Ratios of lesion-to-bladder as well as prostate-to-bladder signal intensity (SI) were calculated to estimate the signal-to-noise-ratio (SNR). RESULTS: Twenty-four lesions were detected on M-b1400 images and compared to C-b1400 images. C-b1400 detected three additional cancer suspicious lesions. Overall image quality was rated significantly better and SI ratios were significantly higher on C-b1400 (2.3 ± 0.8 vs 3.1 ± 1.0, P < 0.001; 5.6 ± 1.8 vs 2.8 ± 0.9, P < 0.001). Comparison of lesion size showed no significant differences between C- and M-b1400 (P = 0.22). CONCLUSION: Combination of a high b-value extrapolation and sFOV may contribute to increase diagnostic accuracy of DWI without an increase of acquisition time, which may be useful to guide targeted prostate biopsies and to improve quality of multiparametric MRI (mMRI) especially under economical aspects in a private practice setting. PMID:24976938

An Ecometric Study of Recent Microfossils using High-throughput Imaging

NASA Astrophysics Data System (ADS)

Elder, L. E.; Hull, P. M.; Hsiang, A. Y.; Kahanamoku, S.

2016-02-01

The era of Big Data has ushered in the potential to collect population level information in a manageable time frame. Taxon-free morphological trait analysis, referred to as ecometrics, can be used to examine and compare ecological dynamics between communities with entirely different species compositions. Until recently population level studies of morphology were difficult because of the time intensive task of collecting measurements. To overcome this, we implemented advances in imaging technology and created software to automate measurements. This high-throughput set of methods collects assemblage-scale data, with methods tuned to foraminiferal samples (e.g., light objects on a dark background). Methods include serial focused dark-field microscopy, custom software (Automorph) to batch process images, extract 2D and 3D shape parameters and frames, and implement landmark-free geometric morphometric analyses. Informatics pipelines were created to store, catalog and share images through the Yale Peabody Museum(YPM; peabody.yale.edu). We openly share software and images to enhance future data discovery. In less than a year we have generated over 25TB of high resolution semi 3D images for this initial study. Here, we take the first step towards developing ecometric approaches for open ocean microfossil communities with a calibration study of community shape in recent sediments. We will present an overview of the `shape' of modern planktonic foraminiferal communities from 25 Atlantic core top samples (23 sites in the North and Equatorial Atlantic; 2 sites in the South Atlantic). In total, more than 100,000 microfossils and fragments were imaged from these sites' sediment cores, an unprecedented morphometric sample set. Correlates of community shape, including diversity, temperature, and latitude, will be discussed. These methods have also been applied to images of limpets and fish teeth to date, and have the potential to be used on modern taxa to extract meaningful

Sensitivity study of voxel-based PET image comparison to image registration algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yip, Stephen, E-mail: syip@lroc.harvard.edu; Chen, Aileen B.; Berbeco, Ross

2014-11-01

Purpose: Accurate deformable registration is essential for voxel-based comparison of sequential positron emission tomography (PET) images for proper adaptation of treatment plan and treatment response assessment. The comparison may be sensitive to the method of deformable registration as the optimal algorithm is unknown. This study investigated the impact of registration algorithm choice on therapy response evaluation. Methods: Sixteen patients with 20 lung tumors underwent a pre- and post-treatment computed tomography (CT) and 4D FDG-PET scans before and after chemoradiotherapy. All CT images were coregistered using a rigid and ten deformable registration algorithms. The resulting transformations were then applied to themore » respective PET images. Moreover, the tumor region defined by a physician on the registered PET images was classified into progressor, stable-disease, and responder subvolumes. Particularly, voxels with standardized uptake value (SUV) decreases >30% were classified as responder, while voxels with SUV increases >30% were progressor. All other voxels were considered stable-disease. The agreement of the subvolumes resulting from difference registration algorithms was assessed by Dice similarity index (DSI). Coefficient of variation (CV) was computed to assess variability of DSI between individual tumors. Root mean square difference (RMS{sub rigid}) of the rigidly registered CT images was used to measure the degree of tumor deformation. RMS{sub rigid} and DSI were correlated by Spearman correlation coefficient (R) to investigate the effect of tumor deformation on DSI. Results: Median DSI{sub rigid} was found to be 72%, 66%, and 80%, for progressor, stable-disease, and responder, respectively. Median DSI{sub deformable} was 63%–84%, 65%–81%, and 82%–89%. Variability of DSI was substantial and similar for both rigid and deformable algorithms with CV > 10% for all subvolumes. Tumor deformation had moderate to significant impact on DSI for

Study on super-resolution three-dimensional range-gated imaging technology

NASA Astrophysics Data System (ADS)

Guo, Huichao; Sun, Huayan; Wang, Shuai; Fan, Youchen; Li, Yuanmiao

2018-04-01

Range-gated three dimensional imaging technology is a hotspot in recent years, because of the advantages of high spatial resolution, high range accuracy, long range, and simultaneous reflection of target reflectivity information. Based on the study of the principle of intensity-related method, this paper has carried out theoretical analysis and experimental research. The experimental system adopts the high power pulsed semiconductor laser as light source, gated ICCD as the imaging device, can realize the imaging depth and distance flexible adjustment to achieve different work mode. The imaging experiment of small imaging depth is carried out aiming at building 500m away, and 26 group images were obtained with distance step 1.5m. In this paper, the calculation method of 3D point cloud based on triangle method is analyzed, and 15m depth slice of the target 3D point cloud are obtained by using two frame images, the distance precision is better than 0.5m. The influence of signal to noise ratio, illumination uniformity and image brightness on distance accuracy are analyzed. Based on the comparison with the time-slicing method, a method for improving the linearity of point cloud is proposed.

Stereotactic radiation treatment planning and follow-up studies involving fused multimodality imaging.

PubMed

Hamm, Klaus D; Surber, Gunnar; Schmücking, Michael; Wurm, Reinhard E; Aschenbach, Rene; Kleinert, Gabriele; Niesen, A; Baum, Richard P

2004-11-01

Innovative new software solutions may enable image fusion to produce the desired data superposition for precise target definition and follow-up studies in radiosurgery/stereotactic radiotherapy in patients with intracranial lesions. The aim is to integrate the anatomical and functional information completely into the radiation treatment planning and to achieve an exact comparison for follow-up examinations. Special conditions and advantages of BrainLAB's fully automatic image fusion system are evaluated and described for this purpose. In 458 patients, the radiation treatment planning and some follow-up studies were performed using an automatic image fusion technique involving the use of different imaging modalities. Each fusion was visually checked and corrected as necessary. The computerized tomography (CT) scans for radiation treatment planning (slice thickness 1.25 mm), as well as stereotactic angiography for arteriovenous malformations, were acquired using head fixation with stereotactic arc or, in the case of stereotactic radiotherapy, with a relocatable stereotactic mask. Different magnetic resonance (MR) imaging sequences (T1, T2, and fluid-attenuated inversion-recovery images) and positron emission tomography (PET) scans were obtained without head fixation. Fusion results and the effects on radiation treatment planning and follow-up studies were analyzed. The precision level of the results of the automatic fusion depended primarily on the image quality, especially the slice thickness and the field homogeneity when using MR images, as well as on patient movement during data acquisition. Fully automated image fusion of different MR, CT, and PET studies was performed for each patient. Only in a few cases was it necessary to correct the fusion manually after visual evaluation. These corrections were minor and did not materially affect treatment planning. High-quality fusion of thin slices of a region of interest with a complete head data set could be performed

An image quality comparison study between XVI and OBI CBCT systems.

PubMed

Kamath, Srijit; Song, William; Chvetsov, Alexei; Ozawa, Shuichi; Lu, Haibin; Samant, Sanjiv; Liu, Chihray; Li, Jonathan G; Palta, Jatinder R

2011-02-04

The purpose of this study is to evaluate and compare image quality characteristics for two commonly used and commercially available CBCT systems: the X-ray Volumetric Imager and the On-Board Imager. A commonly used CATPHAN image quality phantom was used to measure various image quality parameters, namely, pixel value stability and accuracy, noise, contrast to noise ratio (CNR), high-contrast resolution, low contrast resolution and image uniformity. For the XVI unit, we evaluated the image quality for four manufacturer-supplied protocols as a function of mAs. For the OBI unit, we did the same for the full-fan and half-fan scanning modes, which were respectively used with the full bow-tie and half bow-tie filters. For XVI, the mean pixel values of regions of interest were found to generally decrease with increasing mAs for all protocols, while they were relatively stable with mAs for OBI. Noise was slightly lower on XVI and was seen to decrease with increasing mAs, while CNR increased with mAs for both systems. For XVI and OBI, the high-contrast resolution was approximately limited by the pixel resolution of the reconstructed image. On OBI images, up to 6 and 5 discs of 1% and 0.5% contrast, respectively, were visible for a high mAs setting using the full-fan mode, while none of the discs were clearly visible on the XVI images for various mAs settings when the medium resolution reconstruction was used. In conclusion, image quality parameters for XVI and OBI have been quantified and compared for clinical protocols under various mAs settings. These results need to be viewed in the context of a recent study that reported the dose-mAs relationship for the two systems and found that OBI generally delivered higher imaging doses than XVI.

Image resolution enhancement via image restoration using neural network

NASA Astrophysics Data System (ADS)

Zhang, Shuangteng; Lu, Yihong

2011-04-01

Image super-resolution aims to obtain a high-quality image at a resolution that is higher than that of the original coarse one. This paper presents a new neural network-based method for image super-resolution. In this technique, the super-resolution is considered as an inverse problem. An observation model that closely follows the physical image acquisition process is established to solve the problem. Based on this model, a cost function is created and minimized by a Hopfield neural network to produce high-resolution images from the corresponding low-resolution ones. Not like some other single frame super-resolution techniques, this technique takes into consideration point spread function blurring as well as additive noise and therefore generates high-resolution images with more preserved or restored image details. Experimental results demonstrate that the high-resolution images obtained by this technique have a very high quality in terms of PSNR and visually look more pleasant.

Study of UV imaging technology for noninvasive detection of latent fingerprints

NASA Astrophysics Data System (ADS)

Li, Hong-xia; Cao, Jing; Niu, Jie-qing; Huang, Yun-gang

2013-09-01

Using UV imaging technology, according to the special absorption 、reflection 、scattering and fluorescence characterization of the various residues in fingerprints (fatty acid ester, protein, and carboxylic acid salts etc) to the UV light, weaken or eliminate the background disturbance to increase the brightness contrast of fingerprints with the background, and design、setup the illumination optical system and UV imaging system, the noninvasive detection of latent fingerprints remaining on various object surface are studied. In the illumination optical system, using the 266nm UV Nd:YAG solid state laser as illumination light source, by calculating the best coupling conditions of the laser beam with UV liquid core fiber and analyzing the beam transforming characterizations, we designed and setup the optical system to realize the UV imaging uniform illumination. In the UV imaging system, the UV lens is selected as the fingerprint imaging element, and the UV intensified CCD (ICCD) which consists of a second-generation UV image intensifier and a CCD coupled by fiber plate and taper directly are used as the imaging sensing element. The best imaging conditions of the UV lens with ICCD were analyzed and the imaging system was designed and setup. In this study, by analyzing the factors which influence the detection effect, optimal design and setup the illumination system and imaging system, latent fingerprints on the surface of the paint tin box、plastic、smooth paper、notebook paper and print paper were noninvasive detected and appeared, and the result meet the fingerprint identification requirements in forensic science.

Resolving power of diffraction imaging with an objective: a numerical study.

PubMed

Wang, Wenjin; Liu, Jing; Lu, Jun Qing; Ding, Junhua; Hu, Xin-Hua

2017-05-01

Diffraction imaging in the far-field can detect 3D morphological features of an object for its coherent nature. We describe methods for accurate calculation and analysis of diffraction images of scatterers of single and double spheres by an imaging unit based on microscope objective at non-conjugate positions. A quantitative study of the calculated diffraction imaging in spectral domain has been performed to assess the resolving power of diffraction imaging. It has been shown numerically that with coherent illumination of 532 nm in wavelength the imaging unit can resolve single spheres of 2 μm or larger in diameters and double spheres separated by less than 300 nm between their centers.

Thermal imaging of afterburning plumes

NASA Astrophysics Data System (ADS)

Ajdari, E.; Gutmark, E.; Parr, T. P.; Wilson, K. J.; Schadow, K. C.

1989-01-01

Afterburning and nonafterburning exhaust plumes were studied experimentally for underexpanded sonic and supersonic conical circular nozzles. The plume structure was visualized using thermal imaging camera and regular photography. IR emission by the plume is mainly dependent on the presence of afterburning. Temperature and reducing power of the exhaust gases, in addition to the nozzle configuration, determine the structure of the plume core, the location where the afterburning is initiated, its size and intensity. Comparison between single shot and average thermal images of the plume show that afterburning is a highly turbulent combustion process.

A novel smartphone ophthalmic imaging adapter: User feasibility studies in Hyderabad, India

PubMed Central

Ludwig, Cassie A; Murthy, Somasheila I; Pappuru, Rajeev R; Jais, Alexandre; Myung, David J; Chang, Robert T

2016-01-01

Aim of Study: To evaluate the ability of ancillary health staff to use a novel smartphone imaging adapter system (EyeGo, now known as Paxos Scope) to capture images of sufficient quality to exclude emergent eye findings. Secondary aims were to assess user and patient experiences during image acquisition, interuser reproducibility, and subjective image quality. Materials and Methods: The system captures images using a macro lens and an indirect ophthalmoscopy lens coupled with an iPhone 5S. We conducted a prospective cohort study of 229 consecutive patients presenting to L. V. Prasad Eye Institute, Hyderabad, India. Primary outcome measure was mean photographic quality (FOTO-ED study 1–5 scale, 5 best). 210 patients and eight users completed surveys assessing comfort and ease of use. For 46 patients, two users imaged the same patient's eyes sequentially. For 182 patients, photos taken with the EyeGo system were compared to images taken by existing clinic cameras: a BX 900 slit-lamp with a Canon EOS 40D Digital Camera and an FF 450 plus Fundus Camera with VISUPAC™ Digital Imaging System. Images were graded post hoc by a reviewer blinded to diagnosis. Results: Nine users acquired 719 useable images and 253 videos of 229 patients. Mean image quality was ≥ 4.0/5.0 (able to exclude subtle findings) for all users. 8/8 users and 189/210 patients surveyed were comfortable with the EyeGo device on a 5-point Likert scale. For 21 patients imaged with the anterior adapter by two users, a weighted κ of 0.597 (95% confidence interval: 0.389–0.806) indicated moderate reproducibility. High level of agreement between EyeGo and existing clinic cameras (92.6% anterior, 84.4% posterior) was found. Conclusion: The novel, ophthalmic imaging system is easily learned by ancillary eye care providers, well tolerated by patients, and captures high-quality images of eye findings. PMID:27146928

Information content exploitation of imaging spectrometer's images for lossless compression

NASA Astrophysics Data System (ADS)

Wang, Jianyu; Zhu, Zhenyu; Lin, Kan

1996-11-01

Imaging spectrometer, such as MAIS produces a tremendous volume of image data with up to 5.12 Mbps raw data rate, which needs urgently a real-time, efficient and reversible compression implementation. Between the lossy scheme with high compression ratio and the lossless scheme with high fidelity, we must make our choice based on the particular information content analysis of each imaging spectrometer's image data. In this paper, we present a careful analysis of information-preserving compression of imaging spectrometer MAIS with an entropy and autocorrelation study on the hyperspectral images. First, the statistical information in an actual MAIS image, captured in Marble Bar Australia, is measured with its entropy, conditional entropy, mutual information and autocorrelation coefficients on both spatial dimensions and spectral dimension. With these careful analyses, it is shown that there is high redundancy existing in the spatial dimensions, but the correlation in spectral dimension of the raw images is smaller than expected. The main reason of the nonstationarity on spectral dimension is attributed to the instruments's discrepancy on detector's response and channel's amplification in different spectral bands. To restore its natural correlation, we preprocess the signal in advance. There are two methods to accomplish this requirement: onboard radiation calibration and normalization. A better result can be achieved by the former one. After preprocessing, the spectral correlation increases so high that it contributes much redundancy in addition to spatial correlation. At last, an on-board hardware implementation for the lossless compression is presented with an ideal result.

Utility of a human-mouse xenograft model and in vivo near-infrared fluorescent imaging for studying wound healing.

PubMed

Shanmugam, Victoria K; Tassi, Elena; Schmidt, Marcel O; McNish, Sean; Baker, Stephen; Attinger, Christopher; Wang, Hong; Shara, Nawar; Wellstein, Anton

2015-12-01

To study the complex cellular interactions involved in wound healing, it is essential to have an animal model that adequately mimics the human wound microenvironment. Currently available murine models are limited because wound contraction introduces bias into wound surface area measurements. The purpose of this study was to demonstrate utility of a human-mouse xenograft model for studying human wound healing. Normal human skin was harvested from elective abdominoplasty surgery, xenografted onto athymic nude (nu/nu) mice, and allowed to engraft for 3 months. The graft was then wounded using a 2-mm punch biopsy. Wounds were harvested on sequential days to allow tissue-based markers of wound healing to be followed sequentially. On the day of wound harvest, mice were injected with XenoLight RediJect cyclooxygenase-2 (COX-2) probe and imaged according to package instructions. Immunohistochemistry confirms that this human-mouse xenograft model is effective for studying human wound healing in vivo. Additionally, in vivo fluorescent imaging for inducible COX-2 demonstrated upregulation from baseline to day 4 (P = 0·03) with return to baseline levels by day 10, paralleling the reepithelialisation of the wound. This human-mouse xenograft model, combined with in vivo fluorescent imaging provides a useful mechanism for studying molecular pathways of human wound healing. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

The impact of manual threshold selection in medical additive manufacturing.

PubMed

van Eijnatten, Maureen; Koivisto, Juha; Karhu, Kalle; Forouzanfar, Tymour; Wolff, Jan

2017-04-01

Medical additive manufacturing requires standard tessellation language (STL) models. Such models are commonly derived from computed tomography (CT) images using thresholding. Threshold selection can be performed manually or automatically. The aim of this study was to assess the impact of manual and default threshold selection on the reliability and accuracy of skull STL models using different CT technologies. One female and one male human cadaver head were imaged using multi-detector row CT, dual-energy CT, and two cone-beam CT scanners. Four medical engineers manually thresholded the bony structures on all CT images. The lowest and highest selected mean threshold values and the default threshold value were used to generate skull STL models. Geometric variations between all manually thresholded STL models were calculated. Furthermore, in order to calculate the accuracy of the manually and default thresholded STL models, all STL models were superimposed on an optical scan of the dry female and male skulls ("gold standard"). The intra- and inter-observer variability of the manual threshold selection was good (intra-class correlation coefficients >0.9). All engineers selected grey values closer to soft tissue to compensate for bone voids. Geometric variations between the manually thresholded STL models were 0.13 mm (multi-detector row CT), 0.59 mm (dual-energy CT), and 0.55 mm (cone-beam CT). All STL models demonstrated inaccuracies ranging from -0.8 to +1.1 mm (multi-detector row CT), -0.7 to +2.0 mm (dual-energy CT), and -2.3 to +4.8 mm (cone-beam CT). This study demonstrates that manual threshold selection results in better STL models than default thresholding. The use of dual-energy CT and cone-beam CT technology in its present form does not deliver reliable or accurate STL models for medical additive manufacturing. New approaches are required that are based on pattern recognition and machine learning algorithms.