Results showed a good agreement between experimental measurements (with TLD and MOSFET) and MC data for both homogeneous and anthropomorphic breast phantoms. Larger discrepancies are found when comparing the GafChromic™ dose values to the MC results due to the inherent less precise nature of the for …
CIRS ATOM phantoms are a full line of anthropomorphic, cross sectional dosimetry phantoms designed to investigate organ dose, whole body effective dose as well as verification of delivery of therapeutic radiation doses.. ATOM is the only line of dosimetry phantoms to range in sizes from newborn to adult. Six models are available: newborn, 1-year, 5-year and 10-year old pediatric phantoms as well as adult male and female phantoms.. Each phantom is sectional in design with traditional 25 mm thick sections. The sectional surfaces are extremely flat and smooth and do not require any special coatings or treatment. This results in minimal interfaces between the slabs when viewed in a scout or projection X-ray. The ATOM line also differs from other dosimetry phantoms by providing optimized TLD locations specific to 21 inner organs.. Tissue-equivalent epoxy resins are used in all aspects of the phantom. CIRS technology offers superior tissue simulation Dosimetry Verification Phantoms by covering a wider ...
We describe herein a novel life-size phantom model of the intracranial cavity and its validation. The cerebrospinal fluid (CSF) domains including ventricular, cysternal, and subarachnoid spaces were derived via magnetic resonance imaging. Brain mechanical properties and cranio-spinal compliance were set based on published data. Both bulk and pulsatile physiologic CSF flow were modeled. Model validation was carried out by comparisons of flow and pressure measurements in the phantom with published in vivo data of healthy subjects. Physiologic intracranial pressure with 10 mmHg mean and 0.4 mmHg peak pulse amplitude was recorded in the ventricles. Peak CSF flow rates of 0.2 and 2 ml/s were measured in the cerebral aqueduct and subarachnoid space, respectively. The phantom constitutes a first-of-its-kind approach to modeling physiologic intracranial dynamics in vitro. Herein, we describe the phantom design and manufacturing, definition and implementation of its operating parameters, as well as the ...
IMRT Homogeneous Phantom - Complete QA from CT imaging to dose verification. CIRS is the leading manufacturer of medical imaging phantoms and simulators for radiation therapy QA, dosimetry, diagnostic imaging QA as well as training and demonstration phantom
This Spotlight describes the use of optical phantoms as validation tools for probe-based imaging and spectroscopy platforms. Composition of optical phantoms, including scattering and absorbing agents, is discussed in the context of their specific application. Next, requirements for designing optical phantoms for validation of small endoscopic instrumentation is presented including a discussion on the diffuse and sub-diffuse scattering regimes and how this relates to common types of epithelial tissue. This Spotlight concludes with a tutorial section for constructing solid phantoms to simulate thin epithelial tissue structure and liquid phantoms to extract tissue optical properties using probe-based reflectance spectroscopy techniques. For these applications, solid phantoms are made using poly(dimethylsiloxane) and liquid phantoms are made using deionized water as the substrate material. The scope of the chapter is limited to optical phantom design and application and is not intended to describe ...
This Spotlight describes the use of optical phantoms as validation tools for probe-based imaging and spectroscopy platforms. Composition of optical phantoms, including scattering and absorbing agents, is discussed in the context of their specific application. Next, requirements for designing optical phantoms for validation of small endoscopic instrumentation is presented including a discussion on the diffuse and sub-diffuse scattering regimes and how this relates to common types of epithelial tissue. This Spotlight concludes with a tutorial section for constructing solid phantoms to simulate thin epithelial tissue structure and liquid phantoms to extract tissue optical properties using probe-based reflectance spectroscopy techniques. For these applications, solid phantoms are made using poly(dimethylsiloxane) and liquid phantoms are made using deionized water as the substrate material. The scope of the chapter is limited to optical phantom design and application and is not intended to describe ...
Regulation of intracranial pressure (ICP) is vital to proper brain function. Pathologic conditions such as traumatic brain injury and hydrocephalus can cause lethal changes in ICP through an imbalance of fluid passage into and out of the craniospinal space. The relationship between craniospinal volume and pressure determines to a large extent whether such imbalance can be compensated or if it will lead to neuronal damage. Phantom models are predisposed for the evaluation of medical procedures and devices that alter volume in the spinal or cranial space. However, current phantoms have substantial limitations in the reproduction of craniospinal pressure-volume relationships, which need to be overcome prior to their deployment outside the basic research setting. We present herein a novel feedback controlled phantom for the reproduction of any physiologic or pathologic pressure-volume relation. We compare its performance to those of existing passive methods, showing that it follows reference curves ...
MRI Distortion Phantom Model: Model 604 Condition: New The Model 604 is a large field MRI distortion phantom designed for the assessment of MRI distortion caused mainly by the non-linearity of magnetic gradients. It can also help quantify MRI image distortion due to chemical shifts and susceptibility owing to density differences common in diagnostic and RT treatment planning.
Purpose: Epidemiological study of second cancer risk for cancer survivors often requires the dose to normal tissues located outside the anatomy covered by radiological imaging, which is usually limited to tumor and organs at risk. We have investigated the feasibility of using whole body computational human phantoms for estimating out-of-field organ doses for patients treated by Intensity Modulated Radiation Therapy (IMRT). Methods: Identical 7-field IMRT prostate plans were performed using X-ray Voxel Monte Carlo (XVMC), a radiotherapy-specific Monte Carlo transport code, on the computed tomography (CT) images of the torso of an adult male patient (175 cm height, 66 kg weight) and an adult male hybrid computational phantom with the equivalent body size. Dose to the liver, right lung, and left lung were calculated and compared. Results: Considerable differences are seen between the doses calculated by XVMC for the patient CT and the hybrid phantom. One major contributing factor is the treatment ...
© 2018 Multi-center MRI studies can enhance power, generalizability, and discovery for clinical neuroimaging research in brain disorders. Here, we sought to establish the utility of a clustering algorithm as an alternative to more traditional intra-class correlation coefficient approaches in a longitudinal multi-center human phantom study. We completed annual reliability scans on travelling human phantoms. Acquisitions across sites were harmonized prospectively. Twenty-seven MRI sessions were available across four participants, scanned on five scanners, across three years. For each scan, three metrics were extracted: cortical thickness (CT), white matter fractional anisotropy (FA), and resting state functional connectivity (FC). For each metric, hierarchical clustering (Wards method) was performed. The cluster solutions were compared to participant and scanner using the adjusted Rand index (ARI). For all metrics, data clustered by participant rather than by scanner (ARI | 0.8 comparing clusters to
In a computer tomography system, a flexible calibration phantom is utilized simultaneously with analysis of a patient to ensure accuracy of imagry and to facilitate interpretation of tomographs created. The flexible calibration phantom is preferably placed directly upon a patient between a radiation source and a radiation detector. It includes two solid and flexible samples of reference materials, each having a substantially uniform density, and a solid and flexible encasement surrounding the samples of reference material. The encasement has a substantially uniform density different than that of each of the samples of reference material, and the combination provides suitable reference points for proper analysis of tomographs obtained.
TY - JOUR. T1 - Size effect on dose output in phantoms of x-ray tubes in medical x-ray imaging. AU - Zheng, Xiaoming. AU - Nardi, Laura. AU - Murray, Mark. N1 - Includes bibliographical references.. PY - 2017/11/27. Y1 - 2017/11/27. N2 - The purpose of this work was to study how patient size affects the exponent of the power law relating dose to x-ray tube potential in clinical x-ray imaging using phantoms. Computed tomography (CT) dose phantoms of 16 cm and 32 cm in diameter were used to model children and adults respectively. A Fujifilm digital radiographic imaging system and a GE Discovery HD 750 CT scanner were employed to image both phantoms. For the Fujifilm radiographic imaging system, doses were measured at various locations of entrance, centre, exit as well as side locations of the phantoms using a PTW DIADOS diagnostic dosimeter. Standard procedure was employed for CT dose measurements for the GE CT scanner. X-ray exposures were varied by employing various tube voltages kVp and tube ...
RSDs Heart/Thorax Phantom is ideal for evaluation of detectability, extent, and severity of myocardial infarcts in patients. This phantom also provides valid assessment of mammoscintigraphy techniques.
All Blue Phantom models are made using our patented SimulexUS tissue. SimulexUS is specifically designed to match the acoustic properties of human tissue. This means that you can use virtually any ultrasound system with a Blue Phantom model and have a realistic ultrasound image.
NAVIGATING AN INTERVENTIONAL DEVICE - The present invention relates to navigating an interventional device. In particular, the invention relates to a system for navigating an interventional device within a tubular structure of an object, a method for navigating an interventional device within a tubular structure of an object as well as a computer program element and a computer-readable medium. In order to provide enhanced information to the user in an easily comprehensible manner while keeping the X-ray dose to a minimum, a system and a method for navigating an interventional device within a tubular structure of an object are provided, wherein the method comprised the following steps: a) Acquiring 2D X-ray fluoroscopy image data in one projection geometry of a region of interest of the tubular structure; b) detecting the interventional device in the 2D X-ray image; c) determining the 2D position of the interventional device in the 2D X-ray image; d) registering the at least one 2D X-ray image ...
The following evening, despite the Phantoms warnings, a defiant Carlotta appears as Marguerite. At first, the performance goes well, but soon the Phantoms curse takes its effect, backstage, causing the great crystal chandelier to fall down onto the audience. Christine runs to her dressing room and is entranced by a mysterious voice through a secret door behind the mirror, descending, in a dream-like sequence, semi-conscious on horseback by a winding staircase into the lower depths of the Opera. She is then taken by gondola over a subterranean lake by the masked Phantom into his lair. The Phantom introduces himself as Erik and declares his love; Christine faints, so Erik carries her to a suite fabricated for her comfort. The next day, when she awakens, she finds a note from Erik telling her that she is free to come and go as she pleases, but that she must never look behind his mask. In the next room, the Phantom is playing his composition, Don Juan Triumphant. Christines curiosity gets the ...
TY - JOUR. T1 - Target localization accuracy in a respiratory phantom using BrainLab ExacTrac and 4DCT imaging. AU - Matney, Jason E.. AU - Parker, Brent C.. AU - Neck, Daniel W.. AU - Henkelmann, Greg. AU - Rosen, Isaac I.. PY - 2011. Y1 - 2011. N2 - This study evaluated the accuracy of measuring the motion of an internal target using four-dimensional computed tomography (4DCT) scanning and the BrainLAB ExacTrac X-ray imaging system. Displacements of a metal coil implanted in a commercial respiratory phantom were measured in each system and compared to the known motion. A commercial respiratory motion phantom containing a metal coil as a surrogate target was used. Phantom longitudinal motions were sinusoidal with a 4.0 second period and amplitudes ranging from 5-25 mm. We acquired 4DCT and ExacTrac images of the coil at specified respiratory phases and recorded the coordinates of the coil ends. Coil displacement relative to the 0% phase (full-inhale) position were computed for the ExacTrac and ...
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TY - JOUR. T1 - Evaluation of strategies to reduce radiation dose in perfusion ct imaging using a reproducible biologic phantom. AU - Ramirez-Giraldo, Juan C.. AU - Thompson, Scott M.. AU - Krishnamurthi, Ganapathy. AU - Knudsen, Bruce E.. AU - Woodrum, David A.. AU - Callstrom, Matthew R.. AU - McCollough, Cynthia H.. PY - 2013/6/1. Y1 - 2013/6/1. N2 - OBJECTIVE. The purpose of this study is to evaluate radiation dose reduction strategies in perfusion CT by using a biologic phantom. MATERIALS AND METHODS. A formalin-preserved porcine liver was submerged in a 32-cm-wide acrylic phantom filled with water. The portal vein was connected to a continuous flow pump. The phantom was scanned with a perfusion CT protocol using 80 kVp and 400 mAs, every 1 second, for 50 seconds. This was repeated using 100 and 20 mAs. It was also repeated again using 400 mAs to assess reproducibility. A sparser scan frequency was simulated retrospectively. Blood flow was determined for each dataset using the maximum slope ...
SEA WATER PHANTOM 500. The new PHANTOM 500, with its 15 m in length, represents SEA WATERs new flagship and a new landmark for our shipyard in terms of design and technology. The most recent addition to our range and now SEA WATERs leading RIB, the PHANTOM 500 can be supplied in an open configuration, with an enormous sun-pad and an array of spacious lockers for use as a day cruiser, tender or chase boat or with a spacious bow cabin and a custom maxi T-Top for comfortable cruising. The PHANTOM 500 can house either twin inboard diesel engines with sterndrives or other propulsion drives or triple and even quadruple outboard engines and together with one of the new Joystick piloting packages, available both with inboard or outboard engine configurations and/or a bow thruster, manoeuvrability and ease-of-use become unmatched.. Deck layout has once again been designed according to our SEA WATER philosophy: a simple and functional layout, where everything is in the right place and where beauty means ...
Disclosed herein is a spine phantom for calibrating a dual energy x-ray attenuation measurement device for measuring vertebral bone density. Simplified construction of the phantom is made possible by equating the density variations in the three dimensionally complex and inhomogeneous spine as a set of easily machined flat surfaces of different thicknesses. In particular, the spine phantom includes a vertebra-simulating body having a base surface perpendicular to the x-ray beam of the measurement device and defining an intervertebral section, a composite bone section and cortical wall sections. These sections each extend to planes of different heights from the base surface, so as to simulate cartilage, cortical and tabecular bone, and cortical bone wall regions of a human spine, respectively. The spine phantom of the present invention can include multiple vertebra-simulating bodies simulating a range of vertebra types and densities. Moreover, the vertebra-simulating bodies may be embedded in an acrylic
The Anthropomorphic Torso Phantom is used for the evaluation of non-uniform attenuation and scatter compensation methods. The phantom consists of a large, body-shaped cylinder with lung, liver and spine inserts. The phantom simulates the anatomical structures of radioactivity distributions for the upper torso of average to large male/female patients. Lung inserts can be filled with Styrofoam® beads and water to simulate lung tissue density ...
TY - JOUR. T1 - Estimation of Phantom Arm Mechanics About Four Degrees of Freedom After Targeted Muscle Reinnervation. AU - Sartori, Massimo. AU - Van De Riet, Justin. AU - Farina, Dario. PY - 2019/1/28. Y1 - 2019/1/28. N2 - The intuitive control of bionic arms requires estimation of amputees phantom arm movements from residual muscle bio-electric signals. The functional use of myoelectric arms relies on the ability of controlling large sets of degrees of freedom (,3 DOFs) spanning elbow, forearm, and wrist joints. This would assure optimal hand orientation in any environment. As part of this paper we recorded high-density electromyograms with ,190 electrodes from the residual stump of a trans-humeral amputee who underwent targeted muscle reinnervation. We employed clustering to determine eight spatially separated sub-sets of channels sampling electromyograms associated to the actuation of four phantom arm DOFs. We created a large-scale musculoskeletal model of the phantom arm encompassing 33 ...
A couple of the more popular posts in recent months here on Photography Bay deal with reports and concerns about DJI Phantom users and their experience with flyaways. By flyaway, we are talking about when the user loses control of the DJI Phantom quadcopter and it is most often lost or heavily damaged as it heads off into an unanticipated direction.. Obviously, flyaways are a concern for DJI Phantom users, and to read the comment threads below Photography Bays articles or in our forum threads, you would think we have reached an epidemic status. The actual numbers of flyaways are unknown; however, I would speculate that we are still dealing with a small percentage of users. There are many users who have been using the product for years without a single flyaway.. That said, when a flyaway occurs, it is a significant loss to most users when you consider the cost of the equipment often exceeds $1000 for the DJI Phantom and the oft-equipped GoPro camera. And then, of course, there is the danger to ...
A couple of the more popular posts in recent months here on Photography Bay deal with reports and concerns about DJI Phantom users and their experience with flyaways. By flyaway, we are talking about when the user loses control of the DJI Phantom quadcopter and it is most often lost or heavily damaged as it heads off into an unanticipated direction.. Obviously, flyaways are a concern for DJI Phantom users, and to read the comment threads below Photography Bays articles or in our forum threads, you would think we have reached an epidemic status. The actual numbers of flyaways are unknown; however, I would speculate that we are still dealing with a small percentage of users. There are many users who have been using the product for years without a single flyaway.. That said, when a flyaway occurs, it is a significant loss to most users when you consider the cost of the equipment often exceeds $1000 for the DJI Phantom and the oft-equipped GoPro camera. And then, of course, there is the danger to ...
2018 IEEE. A simulation study was conducted to estimate the scatter fraction (SF) and to determine the most suitable line source radial offset displacement required to measure the SF for the total body long axial field-of-view (LAFOV) PET scanner by simulating different cylindrical and anthropomorphic digital phantoms. Simulations are conducted using a scanner model together with scatter phantoms adapted from the NEMA NU-2 2007 scatter phantom design, modified to suit the dimensions of the respective scanners, with line sources of various activities placed at a 45 mm radial offset. SF estimates obtained using the NEMA protocol are compared to values obtained with uniformly filled water phantom of the same length. A whole-body study is conducted using a set of 12 anthropomorphic phantoms with different BMIs, with different organs and anatomical structures filled with realistic concentrations of 18F-FDG. The SF obtained at 45 mm radial offset using 1 kBq/ml with the 200 cm (LAFOV scanner) and 70 ...
We seek to characterize the sampling conditions for iterative image reconstruction exploiting gradient-magnitude sparsity. We seek the number of views necessary for accurate image reconstruction by constrained, total variation (TV) minimization, which is the optimization problem suggested in the compressive sensing (CS) community for this type of sparsity. The preliminary finding here, based on simulations using images of realistic sparsity levels, is that necessary sampling can go as low as N/4 views for an NxN pixel array. This work sets the stage for fixed-exposure studies where the number of projections is balanced against the X-ray intensity per projection ...
Objective(s): Considering the fact that the standardized uptake value (SUV) of a normal lung tissue is expressed as x±SD, x+3×SD could be considered as the threshold value to outline the internal tumor volume (ITV) of a lung neoplasm. Methods: Three hollow models were filled with 55.0 kBq/mL fluorine18- fluorodeoxyglucose (18F-FDG) to represent tumors. The models were fixed to a barrel filled with 5.9 kBq/mL 18F-FDG to characterize normal lung tissues as a phantom. The PET/CT images of the phantom were acquired at rest. Then, the barrel was moved periodically to simulate breathing while acquiring PET/CT data. Volume recovery coefficient (VRC) was applied to evaluate the accuracy of ITVs. For statistical analysis, paired t-test and analysis of variance were applied. Results: The VRCs ranged from 0.74 to 0.98 and significantly varied among gross tumor volumes for delineating ITV (P|0.01). In two-dimensional PET scans, the motion distance did not affect VRC (P|0.05), whereas VRC decreased with increasing
BACKGROUND: We evaluated the effects of attenuation correction and reconstruction techniques on the detection of hypoperfused lesions in brain SPECT imaging. METHODS: A software phantom was constructed using the data available on the BrainWeb database by assigning activity values to grey and white matter. The true attenuation map was generated by assigning attenuation coefficients to six different tissue classes to create a non-uniform attenuation map. The uniform attenuation map was calculated using an attenuation coefficient of 0.15 cm. Hypoperfused lesions of varying intensities and sizes were added. The phantom was then projected as typical SPECT projection data, taking into account attenuation and collimator blurring with the addition of Poisson noise. The projection data were reconstructed using four different methods: filtered back-projection in combination with Changs first-order attenuation correction using the uniform or the true attenuation map and maximum likelihood iterative ...
Purpose: 4D CT is routinely performed during radiation therapy treatment planning of thoracic and abdominal cancers. Compared with the cine mode, the helical mode is advantageous in temporal resolution. However, a low pitch (∼0.1) for 4D CT imaging is often required instead of the standard pitch (∼1) for static imaging, since standard image reconstruction based on analytic method requires the low-pitch scanning in order to satisfy the data sufficient condition when reconstructing each temporal frame individually. In comparison, the flexible iterative method enables the reconstruction of all temporal frames simultaneously, so that the image similarity among frames can be utilized to possibly perform high-pitch and sparse-view helical 4D CT imaging. The purpose of this work is to investigate such an exciting possibility for faster imaging with lower dose. Methods: A key for highpitch and sparse-view helical 4D CT imaging is the simultaneous reconstruction of all temporal frames using the prior ...
In this work, the resistive dipole antenna is designed for sensing the effective dielectric constants of the skull defect as part of the healing stages for craniosynostosis. The performance of the fabricated resistive dipole antenna is analyzed by comparing to the conventional dipole antenna in terms of both frequency and time domain. The measurement result is shown that the amplitude of the reflected pulse is increased as the thickness of the powder is increased.. ...
DESCRIPTION (provided by applicant): Efforts to establish MRA as clinically practical are hampered by lack of realistic beating heart flow phantom. We propose to develop an enhanced Coronary Artery Disease (eCAD) phantom for use by MR researchers, developers and medical equipment manufacturers, eCAD combines advanced features from previously introduced technology with innovative design, materials and processing to create a controlled environment which reproduces clinical conditions. This will be accomplished by: 1) developing functional cardiac structures based on clinical data, 2) combining structures with advanced materials, processing and modular infrastructure to reproduce cardiac functionality, 3) verifying eCAD is anatomically accurate with proper flow patterns and motion under pulsatile flow conditions and 4) demonstrating prototype reproducibility, stability and commercial potential during extended evaluations in academic and industrial environments. Design optimization and manufacturing ...
OBJECTIVES: To investigate the accuracy of bone mineral density (BMD) quantification using dual-layer spectral detector CT (SDCT) at various scan protocols. METHODS: Two validated anthropomorphic phantoms containing inserts of 50-200 mg/cm(3) calcium hydroxyapatite (HA) were scanned using a 64-slice SDCT scanner at various acquisition protocols (120 and 140 kVp, and ... read more 50, 100 and 200 mAs). Regions of interest (ROIs) were placed in each insert and mean attenuation profiles at monochromatic energy levels (90-200 keV) were constructed. These profiles were fitted to attenuation profiles of pure HA and water to calculate HA concentrations. For comparison, one phantom was scanned using dual energy X-ray absorptiometry (DXA). RESULTS: At both 120 and 140 kVp, excellent correlations (R = 0.97, P , 0.001) were found between true and measured HA concentrations. Mean error for all measurements at 120 kVp was -5.6 ± 5.7 mg/cm(3) (-3.6 ± 3.2%) and at 140 kVp -2.4 ± 3.7 mg/cm(3) (-0.8 ± 2.8%). ...
True Real-Time Cardiac MRI with Radial K-Space Sampling in Free Breathing without ECG-synchronization-Improved Image Quality with Iterative Image Reconstruction, SSC02-07, 12026589, Ralf Bauer,
SPEAG has released a novel generic forearm phantom. The SHO-GFPC-V1 phantom was jointly developed with CTIA. It was extensively tested in a round-robin. It can be used for the evaluation of wrist-worn transmitters. The same phantom is also available for specific absorption rate (SAR) testing.
Abstract--To test the feasibility of using 1.1MHz focused ultrasound to increase the diffusion of drug through neurological tissue, tissue mimicking agar phantoms and a water soluble dye mimicking drug were exposed to 1.1MHz ultrasonic sound fields for 1 to 4 minutes in duration. Histology was then performed on the phantoms to assess the effect of ultrasound on the perfusion of drug. Mathematical analysis was used to quantify the extent of perfusion of dye and parametrically fit the experimental data to the theoretical diffusion equation. Results show a substantial increase in drug perfusion and not diffusion like behavior for the sonicated phantoms.
On October 6, Panavision Alga France organized its traditional open house in Aubervilliers (93), where they asked Binocle to establish an innovative 3D workshop. With a theme of shooting high-speed stereoscopic footage using the Vision Research Phantom Flex camera, it was a very successful operation.. Installed in one of the studios of Panavision Alga France, located in the outskirts of Paris, the Binocle team spent the open house day engaged in demonstrations of high-speed stereoscopic shooting. Panavision Alga made available two Phantom Flex cameras in order to assess the viability and performance for this type of usage. Both cameras were equipped with optical Master premium Zeiss 25 mm and were mounted on a Binocle Brigger III stereoscopic rig. The resulting two video streams were managed by Binocles visualization software Disparity Tagger, and were fed to two 46 inch TV screens. An Astro 3D tilt complemented everything.. Vision Researchs in-house software for Phantom on the PC was then ...
We are an official distributor of Data Spectrum Phantoms. Data Spectrum is the worlds leading supplier of high-quality SPECT phantoms and offers a wide range of inserts for the effective evaluation of multiple performance characteristics of any ECT camera. Whether it is a SPECT or positron system, Data Spectrum phantoms and related accessories provide medical imaging investigators with the ability to test imaging equipment and validate that the medical imaging is done correctly and accurately. With a wide range of uses, these products can assist with:. ...
Gamma-Ray Interactions with Matter 29 a much lower fraction of incident gamma radiation than does a similar thickness of aluminum or steel. The attenuation coefficient in Equation is called the linear attenuation coefficient. Figure shows the linear attenuation of solid sodium iodide, a common material used in gamma-ray Size: KB.
Building upon the original Phantom fanless PSU, Phantom 500 uses hybrid fan technology that allows PC users to balance high-power performance with quiet computing. The 500 Watt power supply operates completely silently and fanlessly until its internal temperature reaches a pre-determined user-selected value. At that point, the fan turns on to maintain adequate cooling for higher loads. Users are able to select the temperature at which the fan turns on to fit individual computing needs. Phantom 500 is also equipped with specially designed internal heatsinks and a chassis heatsink for maximum heat dissipation ...
Ive been using my BG4.1 with batteries as an unbalanced mic (XLR to 1/4 mono cable). I have a new mixer that accepts XLR balanced mics and also has 48 volt phantom supply. How do I use this mic in this configuration: (1) Do I remove the internal battery to utilize the phantom supply? (2) If I dont use the phantom supply and continue to use battery instead, does the mic still produce a balanced signal? (3) Ive seen mic cables advertised that are 2 conductor but have XLR on both ends - how do these carry balanced signals (I thought you needed 3 conductors). How do I identify proper cables?|br/| |br/| Thanks.
Summon Phantom Satchel (8 slot, giant, wt 0.1, wr 0%), WAR/CLR/PAL/SHD/BRD, ALL but IKS, Phantom Plate Helm (AC 10, wt 7.5), Phantom Breastplate (AC 17, wt 12.5), Phantom Plate Vambraces (AC 8, wt 8.1), 2 Phantom Plate Bracers (AC 7, wt 5.0), Phantom Plate Gauntlets (AC 9, wt 6.2), Phantom Plate Greaves (AC 10, wt 9.4), Phantom Plate Boots (AC 8, wt 8.1) ...
Veröffentlichung: 13.10.2017. Stil: Melodicrock, Hardrock. Label: Frontiers Records. Facebook: https://www.facebook.com/Pfivemusic. PHANTOM 5, die eigentlich unter dem Namen SUPREMACY gegründet wurden, änderten ihren Bandnamen in PHANTOM 5 bevor sie ihr Debutalbum veröffentlichten. Mit ihrem selbstbetiteltem Debut ernteten sie Lob von Fans und der Fachpresse und nun veröffentlicht die Band um den Mastermind Michale Voss ihr zweites Album „Play To Win. PHANTOM 5 die sich neben Michael Voss noch aus Sänger Claus Lessmann, Gitarrist Robert Boebel und Schlagzeuger Axel Kruse zusammensetzt, versuchen nun mit ihrem 11 Songs umfassenden Albums „Play To Win das Debut zu übertreffen. Mal sehen ob ihnen das gelungen ist.. Schon beim ersten Song „The Change In You bemerkt man das man sich am Mikro keinen besseren hätte wählen können als Claus Lessmann. Toller rockiger Song der den Reigen von 11 neuen Stücken beginnt. Der Hardrocker „Crossfire klingt am Anfang sehr düster, aber das ...
The Fairline Phantom 40 is a very popular flybridge cruiser, held in high regard by boat owners and the industry alike. This boat combines the practicality required for serious, long-distance cruising with the spaciousness and comfort to accommodate four people with an exclusive blend of privacy and sociability. The Phantom 40 is a boat that should feature on the wish list of anyone looking for a second-hand family-friendly flybridge cruiser.. Who and what is the boat designed for ...
In order to extract quantitative parameters from PET images, several physical effects such as photon attenuation, scatter, and partial volume must be taken into account. The main objectives of this work were the evaluation of photon attenuation in small animals and the implementation of two attenuation correction methods based on X-rays CT and segmentation of emission images. The accuracy of the first method with respect to the beam hardening effect was investigated by using Monte Carlo simulations. Mouse- and rat-sized phantoms were acquired in order to evaluate attenuation correction in terms of counts increment and recovery of uniform activity concentration. Both methods were applied to mice and rat images acquired with several radiotracers such as|svg style=vertical-align:-0.0pt;width:21.1625px; id=M1 height=15.8375 version=1.1 viewBox=0 0 21.1625 15.8375 width=21.1625 xmlns:xlink=http://www.w3.org/1999/xlink xmlns=http://www.w3.org/2000/svg||g transform=matrix(.012,-0,0,-.012,.062
Introduction In clinical practice AP pelvis standard protocols are suitable for average size patients. However, as the average body size has increased over the past decades, radiographers have had to improve their practice in order to ensure that adequate image quality with minimal radiation dose to the patient is achieved. Gonad shielding has been found to be an effective way to reduce the radiation dose to the ovaries. However, the effect of increased body size, or fat thickness, in combination with gonad shielding is unclear. The goal of the study was to investigate the impact of gonad shielding in a phantom of adult female stature with increasing fat thicknesses on SNR (as a measure for image quality) and dose for AP pelvis examination. Methods An adult Alderson female pelvis phantom was imaged with a variety of fat thickness categories as a representation of increasing BMI. 72 images were acquired using both AEC and manual exposure with and without gonad shielding. The radiation dose to the ...
Compressive Sensing (CS) theory has great potential for reconstructing Computed Tomography (CT) images from sparse-views projection data and Total Variation- (TV-) based CT reconstruction method is very popular. However, it does not directly incorporate prior images into the reconstruction. To improve the quality of reconstructed images, this paper proposed an improved TV minimization method using prior images and Split-Bregman method in CT reconstruction, which uses prior images to obtain valuable previous information and promote the subsequent imaging process. The images obtained asynchronously were registered via Locally Linear Embedding (LLE). To validate the method, two studies were performed. Numerical simulation using an abdomen phantom has been used to demonstrate that the proposed method enables accurate reconstruction of image objects under sparse projection data. A real dataset was used to further validate the method.
TY - JOUR. T1 - 3D-printed breast phantom for multi-purpose and multi-modality imaging. AU - He, Yaoyao. AU - Liu, Yulin. AU - Dyer, Brandon A.. AU - Boone, John M. AU - Liu, Shanshan. AU - Chen, Tiao. AU - Zheng, Fenglian. AU - Zhu, Ye. AU - Sun, Yong. AU - Rong, Yi. AU - Qiu, Jianfeng. PY - 2019/1/1. Y1 - 2019/1/1. N2 - Background: Breast imaging technology plays an important role in breast cancer planning and treatment. Recently, three-dimensional (3D) printing technology has become a trending issue in phantom constructions for medical applications, with its advantages of being customizable and cost-efficient. However, there is no current practice in the field of multi-purpose breast phantom for quality control (QC) in multi-modalities imaging. The purpose of this study was to fabricate a multi-purpose breast phantom with tissue-equivalent materials via a 3D printing technique for QC in multi-modalities imaging. Methods: We used polyvinyl chloride (PVC) based materials and a 3D printing ...
Supernumerary phantom limb is a condition where the affected individual believes and receives sensory information from limbs of the body that do not actually exist, and never have existed, in contradistinction to phantom limbs, which appear after an individual has had a limb removed from the body and still receives input from it. An fMRI study of a subject with a supernumerary phantom left arm was done by Khateb et al. at the Laboratory of Experimental Neuropsychology at the University of Geneva. When the subject was told to touch her right cheek with the phantom limb, there was increased activity in the motor cortex of her brain in the area roughly corresponding to the left arm. When she announced that she had touched the phantom limb to her cheek, activity was monitored in the area of the somatosensory cortex that corresponded to the right cheek. At times during the experiment, the subject was asked to move the phantom limb to a location that was obstructed or otherwise unfeasible. In these ...
The 1943 adaptation of the Phantom of the Opera is ok and thats unfortunately the best I can say for the movie, I really enjoyed the cast they were campy and fun, the movie used comedy in a way that it didnt ruin the dark romantic atmosphere of the movie, Claude Rains did a fantastic job at playing the Phantom and the sets were all extremely memorable, the film was even filmed in Technicolour but even with all this going for it something was missing and that was the the monster movie I was promised, this is not a monster movie and Im not even sure if I could class it as a horror, the Phantom of the Opera is more of a romantic drama with a dark coat of paint, even twilight has a vampires and werewolves but would you cast that a horror? At least Twilight had monsters which is something I cant say about this so why on earth was it included in a classic monster collection? To most its the Phantom of the Opera but to me its more like the Phantom of the Mediocre.. The Bluray for Phantom of the ...
Traditional image reconstruction methods in rapid dynamic diffuse optical tomography employ l(2)-norm-based regularization, which is known to remove the high-frequency components in the reconstructed images and make them appear smooth. The contrast recovery in these type of methods is typically dependent on the iterative nature of method employed, where the nonlinear iterative technique is known to perform better in comparison to linear techniques (noniterative) with a caveat that nonlinear techniques are computationally complex. Assuming that there is a linear dependency of solution between successive frames resulted in a linear inverse problem. This new framework with the combination of l(1)-norm based regularization can provide better robustness to noise and provide better contrast recovery compared to conventional l(2)-based techniques. Moreover, it is shown that the proposed l(1)-based technique is computationally efficient compared to its counterpart (l(2)-based one). The proposed ...
TY - JOUR. T1 - Validation of practical diffusion approximation for virtual near infrared spectroscopy using a digital head phantom. AU - Oki, Yosuke. AU - Kawaguchi, Hiroshi. AU - Okada, Eiji. PY - 2009/3/1. Y1 - 2009/3/1. N2 - Light propagation in the digital head phantom for virtual near infrared spectroscopy and imaging is calculated by diffusion theory. In theory, diffusion approximation is not valid in a low-scattering cerebrospinal fluid (CSF) layer around the brain. The optical path length and spatial sensitivity profile predicted by the finite element method based upon the diffusion theory are compared with those predicted by the Monte Carlo method to validate a practical implementation of diffusion approximation to light propagation in an adult head. The transport scattering coefficient of the CSF layer is varied from 0.01 to 1.0 mm-1 to evaluate the influence of that layer on the error caused by diffusion approximation. The error is practically ignored and the geometry of the brain ...
OBJECTIVE: Cranial sutures and fontanelles can be reliably demonstrated using three-dimensional (3D) ultrasound with rendering. Our objective was to assess the repeatability and validity of fontanelle surface area measurement on rendered 3D images. METHODS: This was an in-vitro phantom validation study. Four holes, representing fontanelles, were cut on a flat vinyl tile. The phantom was scanned in a test-tank by two sonographers, at four different depths and using two different 3D sweep directions. The surface areas were measured on scan images and also directly from the phantom for comparison. Coefficients of variation (CVs), intraclass correlation coefficients (ICCs) and Bland-Altman plots were used for repeatability analysis. Validity was expressed as the percentage difference of the measured area from the true surface area. RESULTS: Validity of measurement was satisfactory with a mean percentage difference of - 5.9% (median = - 3.5%). The 95% limits of agreement were - 23.9 to 12.1%, suggesting that
We describe a phantom which enables EEG and near-infrared optical tomography to be performed simultaneously over the same volume. The phantom provides a surface electrical contact impedance comparable to that of the human scalp, whilst also possessing an optical scattering coefficient and electrical conductivity equivalent to that of brain tissue. The construction of the phantom is described, as is the resulting simultaneous EEG and near infrared optical tomography experiment, which, to our knowledge, is the first performed on a scale comparable to that of the infant human brain. This imaging experiment successfully shows the suitability of this phantom construction for the assessment of simultaneous EEG and near infrared optical tomography systems.. ©2010 Optical Society of America. Full Article , PDF Article ...
The Phantom of the Opera by Gaston Leroux. A disfigured man, known as the Phantom who loves to strike fear in the minds of the Paris Opera House staff, comes to a young singer, Christine Daae, and tutors her voice. He falls in love with Christine and wants her for his own, but she only has eyes for Raoul Viscount de Chagny. The Phantom, feeling betrayed, kidnaps Christine and brings her to his lair where he plans to make her his eternal bride ...
A method for simulating an anthropomorphic phantom and radioisotope distribution using a Monte Carlo based code is presented. A voxel-based simulation of a Jaszczak phantom was performed and the results compared to both a previously validated geometric-based simulation and experimental data. The method was then extended to create a voxel-based simulation of an anthropomorphic phantom which was validated using an equivalent data set. Good agreement is observed between the voxel-based and geometric-based Jaszczak phantom simulations, but it is noted that for complete agreement, it is crucial that the source distribution is fully aligned to the phantom geometry. With regards to the anthropomorphic phantom simulation, an excellent agreement is observed, which suggests that the activity distribution has been accurately aligned with the phantom. The method proposed can be extended to any arbitrary geometry, with the condition that the activity distribution has been accurately aligned to the phantom geometry.
Early in production, the radar was upgraded to the Westinghouse AN/APQ-72, an AN/APG-50 with a larger radar antenna, necessitating the bulbous nose, and the canopy was reworked to improve visibility and make the rear cockpit less claustrophobic.[21] During its career the Phantom underwent many changes in the form of numerous variants developed. The USAF received Phantoms as the result of Defense Secretary Robert McNamaras push to create a unified fighter for all branches of the military. After an F-4B won the Operation Highspeed fly-off against the Convair F-106 Delta Dart, the USAF borrowed two Naval F-4Bs, temporarily designating them F-110A Spectre in January 1962, and developed requirements for their own version. Unlike the navys focus on interception, the USAF emphasized a fighter-bomber role. With McNamaras unification of designations on 18 September 1962, the Phantom became the F-4 with the naval version designated F-4B and USAF F-4C. The first Air Force Phantom flew on 27 May ...
Comparison of metal artifact in digital tomosynthesis and computed tomography for evaluation of phantoms. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Image quality in digital chest PA and pelvis AP was assessed using two different methods; one based on observations of images of an anthropomorphic phantom, one based on computer modelling using an anthropomorphic voxel phantom. The tube voltage was varied within a broad range (50-150 kV), including those values typically used with screen-film radiography. The tube charge was altered so that approximately the same effective dose was achieved in the modelled patient (anthropomorphic phantom). Two x-ray units were employed using a digital image detector (computed radiography, CR, system) with standard tube filtration and anti-scatter device. Clinical image quality was assessed by a group of radiologists using a visual grading analysis (VGA) technique based on the revised CEC image criteria. Physical image quality was derived from the computer model in terms of the signal-to-noise ratio, SNR for fixed effective dose in the voxel phantom. The computer model uses Monte Carlo simulations of the ...
Background: Periodic quality control (QC) procedures are important in order to guarantee the image quality of radiological equipment and are also conducted using phantoms simulating human body. Objective: To perform (QC) measurements in intraoral imaging devices, a new and simple phantom was manufactured. Besides, to simplify QC procedures, computerized LabView-based software has been devised, enabling determination of image quantitative parameters in real time or during post processing.Material and Methods: In this experimental study, the novel developed phantom consists of a Polymethyl methacrylate (PMMA) circular insert. It is able to perform a complete QC image program of X-ray intraoral equipment and also causes the evaluation of image uniformity, high and low contrast spatial resolution, image linearity and artefacts, with only two exposures. Results: Three raters analyzed the images using the LabView dedicated software and determined the quantitative and qualitative parameters in an innovative
TY - JOUR. T1 - Determination of equivalent breast phantoms for different age groups of Taiwanese women. T2 - An experimental approach. AU - Dong, Shang Lung. AU - Chu, Tieh Chi. AU - Lin, Yung Chien. AU - Lan, Gong Yau. AU - Yeh, Yu Hsiu. AU - Chen, Sharon. AU - Chuang, Keh Shih. PY - 2011/1/1. Y1 - 2011/1/1. N2 - Purpose: Polymethylmethacrylate (PMMA) slab is one of the mostly used phantoms for studying breast dosimetry in mammography. The purpose of this study was to evaluate the equivalence between exposure factors acquired from PMMA slabs and patient cases of different age groups of Taiwanese women in mammography. Methods: This study included 3910 craniocaudal screen/film mammograms on Taiwanese women acquired on one mammographic unit. The tube loading, compressed breast thickness (CBT), compression force, tube voltage, and target/filter combination for each mammogram were collected for all patients. The glandularity and the equivalent thickness of PMMA were determined for each breast using ...
Purpose: 123I-labelled radioligands are commonly used for single-photon emission computed tomography (SPECT) imaging of the dopaminergic system to study the dopamine transporter binding. The aim of this work was to compare the quantitative capabilities of two different SPECT systems through Monte Carlo (MC) simulation. Methods: The SimSET MC code was employed to generate simulated projections of a numerical phantom for two gamma cameras equipped with a parallel and a fan-beam collimator, respectively. A fully 3D iterative reconstruction algorithm was used to compensate for attenuation, the spatially variant point spread function (PSF) and scatter. A post-reconstruction partial volume effect (PVE) compensation was also developed. Results: For both systems, the correction for all degradations and PVE compensation resulted in recovery factors of the theoretical specific uptake ratio (SUR) close to 100%. For a SUR value of 4, the recovered SUR for the parallel imaging system was 33% for a ...
Chapter V- The Test. There was a slight pause in the beating of whatever organ was lodged in his ribcage at the surprise his companion was giving him. He uncharacteristically fumbled over the latches in gross desire.. The ability to rival Danny Phantom? It was if the gods had granted asylum on his very soul.. Well, if he actually had one.. Clockwork raised an amused eyebrow as he flipped the case top eagerly and stared.. What the fuck is that? Phantom pointed at a small, round jewel and found it utterly unimpressive.. His companion stare did not waver. My way of trusting you in your test.. Seriously, did Clockwork have to put such an insignificant trinket in such a threatening looking case?. Phantom picked it up for closer inspection. It was the size of a marble. You know-shit!. The marble began to go from indifferent to lightning hot in two seconds and he wouldve thrown it had it not developed an adhesive to his palm. It stuck like glue to his skin as he waved his arm in pain.. Get ...
Central nervous system changes in cortical regions are often considered to be the main underlying mechanism of phantom limb pain1,2. Phantom limb pain has been connected to changes in many regions of the brain, including the anterior cingulate cortex, brainstem, thalamus and, most importantly, the primary somatosensory cortex and the primary motor cortex2,11,15. Often these cortical changes are associated with cortical reorganization in the brain15. The cortical reorganization may be a result of axonal sprouting11. Axonal sprouting is thought to be caused by increased excitability, which is a result of increased presence of excitatory neurotransmitter2,11. Increased excitability in various cortical regions can lead to the experience of phantom limb pain11. It has also been suggested that inhibitory fibers are lost due to amputation and this loss may cause cortical reorganization in areas where c-fibers usually have an inhibitory effect11. Cortical reorganization is often observed in areas that ...
A case of supernumerary phantom limb is described after a haematoma within the right basal ganglia. The phantom, which persisted for many months, occurred in the context of severe left hemiplegia, sensory loss, hemianopia, and neglect. The subjective reality of this third arm caused the patient considerable distress, which was not ameliorated by his attempts to rationalise its existence. Although deeply confused by the phantom, the patient was otherwise fully oriented, with a high verbal IQ, and normal cognition. Two distinct formal interpretations of the phenomenon are discussed.. ...
Blue Phantom lumbar puncture and lumbar epidural ultra-durable replacement tissue. For use with Blue Phantom spinal epidural and lumbar puncture training models.
Phantom Limb Label music on CD, MP3 and Vinyl available at Juno Records. Listen to Phantom Limb now using our online music player. Phantom Limb
Comparison of the Breast Dose based on the Existence of the Bismuth Breast Protection Shield for Automatic Exposure Control and Manual Exposure Control with the Coronary Artery CT Angiography - coronary artery CT angiography;bismuth breast shield;MEC;AEC;breast dose;
Fingerprint Dive into the research topics of Dynamic phantom with two stage-driven absorbers for mimicking hemoglobin changes in superficial and deep tissues. Together they form a unique fingerprint. ...
CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Abstract: Current computed tomography (CT) scanners, including micro-CT scanners, utilize a point x-ray source. As we target higher and higher spatial resolutions, the reduced x-ray focal spot size limits the temporal and contrast resolutions achievable. To overcome this limitation, in this paper we propose to use a line-shaped x-ray source so that many more photons can be generated, given a data acquisition interval. In reference to the simultaneous algebraic reconstruction technique (SART) algorithm for image reconstruction from projection data generated by an x-ray point source, here we develop a generalized SART algorithm for image reconstruction from projection data generated by an x-ray line source. Our numerical simulation results demonstrate the feasibility of our novel line-source-based x-ray CT approach and the proposed generalized SART algorithm.
We aimed at reviewing design and realisation of perfusion/flow phantoms for validating quantitative perfusion imaging (PI) applications to encourage best practices. A systematic search was performed on the Scopus database for
0021] In the manufacture of shield 10, such foam layer 14 is provided as having a first surface, referenced in phantom at 16 in FIG. 1, and a second surface, 18, which together define a thickness dimension, referenced at T1, therebetween. As sized to form the shield 10, layer 14 further has interior portion, which is the area bounded in phantom at 20, surrounded by a perimeter portion, referenced at 22. With layer 14 being so provided, interior portion of 20 thereof may be hot-pressed against or by a heated tool, or otherwise compression molded or thermoformed, through the thickness dimension T1 to form a top wall portion, 30, of shield 10 having a compressed thickness referenced at T2. With the perimeter portion 22 of layer 14 remaining uncompressed, the thickness dimension T1 thereof thus extends downwardly from the top wall portion 30 to form a side wall portion, 32, of shield 10 which together with top wall portion 30 defines the compartment 14 as having a depth referenced at d. As shown, ...
An AlN film as an underlayer is epitaxially grown on a substrate having a dislocation density of 1011/cm2 or below and a crystallinity of 90 seconds or below in full width at half maximum (FWHM) of an X-ray rocking curve at (002) reflection. Then, on the AlN film an n-GaN film is epitaxially grown as a conductive layer having a dislocation density of 1010/cm2 or below and a crystallinity of 150 seconds or below in full width at half maximum (FWHM) of an X-ray rocking curve at (002) reflection, to fabricate a semiconductor element.
To overcome the limitations of the classical volume scoring method for quantifying coronary calcifications, including accuracy, variability between examinations, and dependency on plaque density and acquisition parameters, a mesh-based volume measurement method has been developed. It was evaluated and compared with the classical volume scoring method for accuracy, i.e., the normalized volume (measured volume/ground-truthed volume), and for variability between examinations (standard deviation of accuracy). A cardiac computed-tomography (CT) phantom containing various cylindrical calcifications was scanned using different tube voltages and reconstruction kernels, at various positions and orientations on the CT table and using different slice thicknesses. Mean accuracy for all plaques was significantly higher (p , 0.0001) for the proposed method (1.220 +/- 0.507) than for the classical volume score (1.896 +/- 1.095). In contrast to the classical volume score, plaque density (p = 0.84), ...
Abstract: : Purpose:To evaluate the test-retest reproducibility of ATL HDI-5000 CDI measurements of volumetric blood flowas compared to an in-vitro phantom flow model. Methods:A phantom flow model was constructed using agarose gel to mimic fatty soft tissue. 1.57mm and 2.36mm lumens were created in the gel. A UHDC flow system pumped blood mimicking fluid through each tube at three different rates. The ATL HDI-5000 measured the velocity and volumetric flow in the phantom model using cineloops (a cineloop is a rapidly acquired sequence of CDI images). A newly developed software package from ATL calculated both volumetric flow and velocity from the cineloops. Measurements were performed with the probe in four different positions: 1) 45° angle, parallel to the flow, 2) 45° angle, offset to the flow, 3) 75° angle, parallel to the flow, and 4) 75° angle, offset to the flow. The coefficient of variance was then calculated for each of the probe positions. Results:The average coefficients of ...
TY - GEN. T1 - Hemorrhages detection in atherosclerotic plaques using ultrasound and photoacoustic, phantom study. AU - Gouteux, L.K.L.. AU - Arabul, M.Ü.. AU - Rutten, M.C.M.. AU - Van De Vosse, F.N.. AU - Lopata, R.G.P.. PY - 2017/10/31. Y1 - 2017/10/31. N2 - Rupture of an atherosclerotic plaque in the carotid artery is one of the main causes of stroke and stroke-induced death. Currently, to prevent this risk, endarterectomy is performed based on the stenosis grade assessed with Duplex ultrasound (US). However, plaque composition, e.g. presence of lipids and hemorrhages, is a more important factor of rupture risk than stenosis. The optical absorption of hemorrhages (composed of coagulated, deoxygenated blood) is different from that of oxygenated blood and allows their distinction using different wavelengths. In this study, photoacoustic (PA) imaging is used to detect intraplaque hemorrhages using contrast in optical absorption in combination with the resolution of US.. AB - Rupture of an ...
A few additional notes concerning adverse effects of eddy currents. . . .. Multiple eddy currents with different time constants always coexist. The most rapid eddy currents (with time constants on the order of a few hundred micro(μ)-seconds) are present in the RF coil and shield. These are responsible for the Nyquist N/2 artifact described above. Intermediate term eddy currents (on the order 1-100 milliseconds) typically originate in the walls of the cryostat or outer radiation shields and produce shading artifacts on fast (turbo) spin echo or gradient echo images. Eddy currents with long time constants (hundreds of milliseconds) often derive from the inner cryogen shields and produce frequency drifts in the main field. This may be manifest on images as insufficient fat or water suppression.. Eddy currents are particularly problematic in localized spectroscopy, where they cause broadened resonances and distorted line shapes, especially in short TE experiments. At times they may completely ...
Nondestructive, three-dimensional (3-D) element-concentration mapping was performed and high spatial resolution and quantitative applicability were demonstrated. X-ray computed tomography using synchrotron radiation developed at SPring-8 (SP-μCT) enabled us to acquire high-resolution tomographic images with X-ray energies just above and below the absorption edge of an element. Concentration of the element could be calculated from the difference of these images with a correction using standard material. A 3-D Cs concentration map of a partially molten granite was obtained by this technique and compared with a 2-D element map produced by an electron-probe X-ray microanalyzer (EPMA), with respect to spatial and compositional resolution. A spatial resolution of about 20 μm was achieved by SP-μCT. The compositional resolution of ±2.5 wt% was achieved using the following two calibration processes of linear attenuation coefficients (LAC): (1) calibration based on the empirical relationship between ...
The Phantom® v611 is the unique follow up to our v12.1 camera. With an improved body style, a lighter weight, and additional on-camera controls, i
Acquired data in tomographic imaging systems are subject to physical or detector based image degrading effects. These effects need to be considered and modeled in order to optimize resolution recovery. However, accurate modeling of the physics of data and acquisition processes still lead to an ill-posed reconstruction problem, because real data is incomplete and noisy. Real images are always a compromise between resolution and noise; therefore, noise processes also need to be fully considered for optimum bias variance trade off. Image degrading effects and noise are generally modeled in the reconstruction methods, while, statistical iterative methods can better model these effects, with noise processes, as compared to the analytical methods. Regularization is used to condition the problem and explicit regularization methods are considered better to model various noise processes with an extended control over the reconstructed image quality. Emission physics through object distribution properties ...
An apparatus, system and method are disclosed for eliminating phantom power wastage utilizing a power tap. An insulation casing creates a receiving space for a printed circuit board which mounts male blades, female receptacles, phantom power indication and a mechanical electrical switching capability is disclosed. The conductive male blades and female receptacles create a cross pattern for a two pronged power tap that allows miniaturization of the power tap so as to allow full access to adjacent electrical outlets. Switching states include normally open which permits zero power flow and normally closed which permits power indication and allows power to flow from conductive male blades to conductive female receiving receptacles.
Bea Harper Phantom of the Opera (1943) Cast: Claude Rains, Susanna Foster, Nelson Eddy and Edgar Barrier Director: Arthur Lubin Universal Studios has its fair share of heavy-hitters in terms of horror icons- Dracula, the Wolf Man, Gill Man, the Mummy and Frankensteins Creature, that often they tend to overshadow the Phantom. By the 40s […]
Erik, the man with a hideous skull-like face who lives in furtive seclusion beneath a Paris opera house, is in love with a beautiful singer. He masks his deformity and commits various murders in order to attain his ends, but nevertheless fails to get the girl. His story is told in Gaston Lerouxs 1911 novel The Phantom Of The Opera, which was filmed in 1925 with Lon Chaney Senior in the leading role. Since then it has become a standard part of the cinemas horror repertoire, with remakes appearing in 1943 starring Claude Rains and in 1962 with Herbert Lom. A later version entitled Phantom Of The Paradise (1974) had William Finley in an updated story with a rock-music setting directed by Brian DePalma with an award-winning soundtrack by Paul Williams. There was also a made-for-television movie in 1983 starring Maximillian Schell, and another notable performance came from Robert Englund in a 1986 version which played-up the horror elements of the story. Since then Lerouxs hoary old tale has been ...
Syria & The Phantom Dispatches From The Edge Conn Hallinan June 26, 2012 What was that Turkish F-4 Phantom II up to when the Syrians shot it down? Ankara said the plane strayed into Syrian airspace, but quickly left and was over international waters when it was attacked, a simple case of carelessness on the…
Syria & The Phantom Dispatches From The Edge Conn Hallinan June 26, 2012 What was that Turkish F-4 Phantom II up to when the Syrians shot it down? Ankara said the plane strayed into Syrian airspace, but quickly left and was over international waters when it was attacked, a simple case of carelessness on the…
Phantom arms, legs, fingers and toes: seemingly the stuff of horror movies. Yet for nearly 70 percent of the 4 million amputees in the United States, vivid sensations in missing body parts-such as pressure, tingling, warmth, cold, and pain that can be both constant and excruciating-are all too real. Phantom limbs have puzzled scientists for…
Experience the Power of Dry with New Prescription Treatment® Brand Phantom pressurized insecticide.. Control general pest in commercial accounts easier and faster than ever. When it comes to controlling pests in commercial accounts, new Phantom® pressurized insecticide delivers:. ...
The Phantom Of The Opera Also see Alternate Cover Editions for this ISBN ACE ACE First published in French as a serial in The Phantom of the Opera is a riveting story that revolves around the young Swedish Christine
General Objective of the Project. The goal of the project is to study the different combinations of Left Ventricular (LV) function and myocardial perfusion abnormalities using nuclear medicine procedures and a dynamic cardiac phantom. The general objective is to optimize of diagnostic value for the early detection of mild coronary artery disease in the framework of improving the public and private health services.. Specific Scientific and Technological Objectives of the Project. (a) Construction of a specific dynamic cardiac phantom (not available in the market in the desired form),. (b) Use the phantom to experimentally simulate CAD (myocardial perfusion defects) and different stages of Left ventricular dysfunction,. (c) Image acquisition and processing of phantom simulated cardiac normal and abnormal conditions,. (d) Development of a specific software package for the storage, handling and analysis of the diagnostic evaluation of the acquired images (not available in the market in the desired ...
Fingerprint Dive into the research topics of Image-based point spread function implementation in a fully 3D OSEM reconstruction algorithm for PET. Together they form a unique fingerprint. ...
Background: Invasive coronary angiography has inherent limitations for displaying complex vascular anatomy to its two dimensional projection nature. Despite these limitations, it remains the gold standard for comparisons with new coronary imaging modalities, such as computed tomography (CT). The purpose of this study was to evaluate the accuracy of stenosis assessment by CT and quantitative coronary angiography (QCA) compared to known dimensions of a custom-designed coronary phantom with cardiac motion simulation.. Methods: Nineteen coronary vessel phantoms were used consisting of acrylic tubes with precisely drilled and measured dimensions. Each phantom had three stenoses of mild (25%), moderate (50%), and severe (75%) grade and of 4 different shapes: circular concentric, circular eccentric, non-circular regular, non-circular irregular, totaling 57 stenoses. The reference sites varied between 1.5 and 4 mm. Phantom imaging was performed at rest and with simulated cardiac motion at a heart rate ...
PURPOSE: Motion-compensated temporal processing can have a major impact on improving the image quality in gated cardiac single photon emission computed tomography (SPECT). In this work, we investigate the effect of different optical flow estimation methods for motion-compensated temporal processing in gated SPECT. In particular, we explore whether better motion estimation can substantially improve reconstructed image quality, and how the estimated motion would compare to the ideal case of known motion in terms of reconstruction. METHODS: We consider the following three methods for obtaining the image motion in 4D reconstruction: (1) the Horn-Schunck optical flow equation (OFE) method, (2) a recently developed periodic OFE method, and (3) known cardiac motion derived from the NURBS-based cardiac-torso (NCAT) phantom. The periodic OFE method is used to exploit the inherent periodic nature in cardiac gated images. In this method, the optical flow in a sequence is modeled by a Fourier harmonic