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.

Purpose: Investigations have shown that a Cobalt-60 (Co-60) radioactive source has the potential to play a role in intensity modulated radiation therapy (IMRT). In this paper, Co-60 tomotherapys conformal dose delivery potential is evaluated by delivering conformal dose plans on a cylindrical homogeneous phantom containing clinical structures similar to those found in a typical head and neck (H and N) cancer. Also, the clinical potential of Co-60 tomotherapy is investigated by generating 2D clinical treatment plans for H and N and prostate anatomical regions. These plans are compared with the 6 MV based treatment plans for modalities such as linear accelerator-based tomotherapy and broad beam IMRT, and 15 MV based 3D conformal radiation therapy (3DCRT).Methods: For experimental validation studies, clinical and nonclinical conformal dose patterns were delivered on circular, homogeneous phantoms containing GafChromic film. For clinical planning study, dose calculations were performed with the ...

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 ...

Paco Rabanne Phantom: Paco Rabanne Phantom Deodorant Stick 75ml - Paco Rabanne Phantom Eau de Toilette Spray 100 ml - Paco Rabanne Phantom Deodorant Spray 1

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

Purpose: To design a precise perfusion phantom mimicking capillaries of the brain vasculature which could be used to test various perfusion protocols and algorithms which generate perfusion maps. Methods: A perfusion phantom was designed in Solidworks and built using additive manufacturing. The phantom was an overall cylindrical shape of diameter and height 20mm and containing capillaries of 200μm or 300μm which were parallel and in contact making up the inside volume where flow was allowed. We created a flow loop using a peristaltic pump and contrast agent was injected manually. Digital Subtraction Angiographic images and low contrast images with cone beam CT were acquired after the contrast was injected. These images were analyzed by our own code in LabVIEW software and Time-Density Curve, MTT and TTP was calculated. Results: Perfused area was visible in the cone beam CT images; however, individual capillaries were not distinguishable. The Time-Density Curve acquired was accurate, sensitive ...

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 ...

The Phantom Zone was a pocket universe discovered by Jor-El that existed outside the space-time continuum; used on the planet Krypton as a humane method of imprisoning criminals. Previously, criminals were punished by being sealed into capsules and rocketed into orbit in suspended animation with crystals attached to their foreheads to slowly erase their criminal tendencies; Klax-Ar was one criminal who received this punishment but escaped. Gra-Mo was the last to suffer the punishment, for it was then abolished in favor of the Zone. The inmates of the Phantom Zone reside in a ghost-like state of existence from which they can observe, but cannot interact with, the regular universe. Inmates do not age or require sustenance in the Phantom Zone; furthermore, they are telepathic and mutually insubstantial. As such, they were able to survive the destruction of Krypton and focus their attention on Earth, as most of the surviving Kryptonians now reside there. Most have a particular grudge against ...

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.. ...

State of Mind Black Ice - Eve 10 inch (x Phantom Limbs) - Black Ice is a project from two musicians from the postpunk band The Phantom Limbs. The music of The Phantom Limbs sounds pretty cheerful in comparison with the postpunk/deathrock that Black Ice plays. Their music might be darker but their sound is at times just as chaotic as that of

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 ...

Imaging of dynamic changes in blood parameters, functional brain imaging, and tumor imaging are the most advanced application areas of diffuse optical tomography (DOT). When dealing with the image reconstruction problem one is faced with the fact that near-infrared photons, unlike X-rays, are highly scattered when they traverse biological tissue. Image reconstruction schemes are required that model the light propagation inside biological tissue and predict measurements on the tissue surface. By iteratively changing the tissue-parameters until the predictions agree with the real measurements, a spatial distribution of optical properties inside the tissue is found. The optical properties can be related to the tissue oxygenation, inflammation, or to the fluorophore concentration of a biochemical marker. If the model of light propagation is inaccurate, the reconstruction process will lead to an inaccurate result as well. Here, we focus on difficulties that are encountered when DOT is employed for ...

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 ...

That includes flight servicings or other general unserviceabilities.. Also under investigation is the use of multi-spectral cameras including thermal imagery.. This would potentially allow us to detect less obvious paint defects, where non-uniform emissivity results from changes in surface roughness, SQNLDR Smith said.. Commander Air Mobility Group Air Commodore William Kourelakos said introducing the Phantom drone was an example of bottom-up innovation from within 36SQN under the Air Force Safety Always Program.. Introducing this drone and these procedures goes further to reducing workplace health and safety risks to so far as reasonably practicable, AIRCDRE Kourelakos said.. The Phantom was introduced into 36SQN service with the aid of Armys 20th Surveillance and Target Acquisition Regiment.. The Army has extensive experience using this particular model, and managing the information downloaded from it, SQNLDR Smith said.. We manage the drone through a standalone laptop, and have ...

That includes flight servicings or other general unserviceabilities.. Also under investigation is the use of multi-spectral cameras including thermal imagery.. This would potentially allow us to detect less obvious paint defects, where non-uniform emissivity results from changes in surface roughness, SQNLDR Smith said.. Commander Air Mobility Group Air Commodore William Kourelakos said introducing the Phantom drone was an example of bottom-up innovation from within 36SQN under the Air Force Safety Always Program.. Introducing this drone and these procedures goes further to reducing workplace health and safety risks to so far as reasonably practicable, AIRCDRE Kourelakos said.. The Phantom was introduced into 36SQN service with the aid of Armys 20th Surveillance and Target Acquisition Regiment.. The Army has extensive experience using this particular model, and managing the information downloaded from it, SQNLDR Smith said.. We manage the drone through a standalone laptop, and have ...

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 […]

id:4940969148487,title:Columbian Phantom Quartz Point (approx. 7.5x2.5x2cm),handle:columbian-phantom-quartz-point-approx-7-5x2-5x2cm,description:,published_at:2020-12-13T08:27:31+13:00,created_at:2020-12-13T08:27:31+13:00,vendor:Inspire Me Online,type:Crystals, Fossils, Shells $40-$69,tags:[Crystals \u0026 Fossils,Points],price:6200,price_min:6200,price_max:6200,available:false,price_varies:false,compare_at_price:null,compare_at_price_min:0,compare_at_price_max:0,compare_at_price_varies:false,variants:[{id:32736467255367,title:Default Title,option1:Default Title,option2:null,option3:null,sku:CPQP,requires_shipping:true,taxable:true,featured_image:null,available:false,name:Columbian Phantom Quartz Point (approx. 7.5x2.5x2cm),public_title:null,options:[Default ...

You dont have to travel miles away from your home to have fun. Enjoy yourself right from your house with the Hathaway Phantom 7.5-Feet Air Hockey table. This is an elegant arcade-style hockey that has several features which are meant to give you total excitement.. The classy 89 Length by 48 Width play area is made of powerful PVC which has been further laminated with MDF to support high-speed play. This is a futuristic air hockey table that contains lots of high-tech features. In this article, we are going to cover everything that you need to know about the Hathaway Phantom 7.5-Feet Air Hockey table. ...

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…

The phantom eye syndrome (PES) is a phantom pain in the eye and visual hallucinations after the removal of an eye (enucleation, evisceration). Many patients experience one or more phantom phenomena after the removal of the eye: Phantom pain in the (removed) eye (prevalence: 26%) Non-painful phantom sensations Visual hallucinations. About 30% of patients report visual hallucinations of the removed eye. Most of these hallucinations consist of basic perceptions (shapes, colors). In contrast, visual hallucinations caused by severe visual loss without removal of the eye itself (Charles Bonnet syndrome) are less frequent (prevalence 10%) and often consist of detailed images. Phantom pain and non-painful phantom sensations result from changes in the central nervous system due to denervation of a body part. Phantom eye pain is considerably less common than phantom limb pain. The prevalence of phantom pain after limb amputation ranged from 50% to 78%. The prevalence of phantom eye pain, in contrast, is ...

V.S. Ramachandran, a neurologist and psychologist at UC San Diego and a leading authority on phantom limb sensations, says it has long been known that some people who are born without arms have vivid phantom arms. They can swing them around, wave goodbye and make complicated gestures.. This suggests that an intact body image - the maps of the body laid down in the brain before and after birth - can develop without actual limbs. So-called mirror neurons that map the actions and intentions of others into ones own brain may help bring the phantoms to life, Ramachandran says.. …. This got Ramachandran wondering whether the phantoms applied to transsexuality. To find out, he surveyed 20 male-to-female transsexual women and 29 female-to-male transsexual men.. The first finding was intriguing. Only 6 out of 20, or 30 percent, of the transsexual women who had had their penises removed reported feeling a phantom phallus. But 58 percent of normal men have such sensations after the surgery.. The ...

Mammography is currently the standard imaging modality used to screen women for breast abnormalities and, as a result, it is a tool of great importance for the early detection of breast cancer. Physical phantoms are commonly used as surrogates of breast tissue to evaluate some aspects of the performance of mammography systems. However, most phantoms do not reproduce the anatomic heterogeneity of real breasts. New fabrication technologies, such as 3D printing, have created the opportunity to build more complex, anatomically realistic breast phantoms that could potentially assist in the evaluation of mammography systems. The primary objective of this work is to present a simple, easily reproducible methodology to design and print 3D objects that replicate the attenuation profile observed in real 2D mammograms. The secondary objective is to evaluate the capabilities and limitations of the competing 3D printing technologies, and characterize the x-ray properties of the different materials they use. ...

Computational anthropomorphic phantoms are computer models of human anatomy used in the calculation of radiation dose distribution in the human body upon exposure to a radiation source. Depending on the manner to represent human anatomy, they are categorized into two classes: stylized and tomographic phantoms. Stylized phantoms, which have mainly been developed at the Oak Ridge National Laboratory (ORNL), describe human anatomy by using simple mathematical equations of analytical geometry. Several improved stylized phantoms such as male and female adults, pediatric series, and enhanced organ models have been developed following the first hermaphrodite adult stylized phantom, Medical Internal Radiation Dose (MIRD)-5 phantom. Although stylized phantoms have significantly contributed to dosimetry calculation, they provide only approximations of the true anatomical features of the human body and the resulting organ dose distribution. An alternative class of computational phantom, the tomographic ...

In fluorescence molecular tomography (FMT), diffuse-light measurements are obtained from a series of source-detector pairs placed on the boundary of the medium. The sensitivity of measurements deteriorates quickly with increased distance from the sources and detectors and therefore yields poor depth quantitative recovery. A depth compensation algorithm is presented in this paper to reconstruct fluorescent inclusions in deep tissues. Two weight matrixes are employed to level off sensitivity differences and enhance prominent elements of the solution. Results of numerical and phantom experiments demonstrate that both relative quantitation and spatial resolution of FMT are improved for inclusions at different depths.. © 2012 Optical Society of America. Full Article , PDF Article ...

Background: The aim of this study was to determine the impact of respiratory motion correction on SPECT MPI and on defect detection using a phantom assembly. Methods: SPECT/CT data were acquired using an anthropomorphic phantom with inflatable lungs and with an ECG beating and moving cardiac compartment. The heart motion followed the respiratory pattern in the cranio-caudal direction to simulate normal or deep breathing. Small or large transmural defects were inserted into the myocardial wall of the left ventricle. SPECT/CT images were acquired for each of the four respiratory phases, from exhale to inhale. A respiratory motion correction was applied using an image-based method with transformation parameters derived from the SPECT data by a non-rigid registration algorithm. A report on defect detection from two physicians and a quantitative analysis on MPI data were performed before and after applying motion correction. Results: Respiratory motion correction eliminated artifacts present in the ...

TY - GEN. T1 - Concentration dependent absorption and scattering characteristics of gold nanoparticles embedded in liquid phantoms. AU - Moon, Seyoung. AU - Sim, Eunji. AU - Kim, Donghyun. PY - 2007. Y1 - 2007. N2 - For biomedical applications, various optical techniques have been explored, all of which are inherently subject to the limited penetration depth of observation. Nanoparticles have thus been introduced as a potential agent to overcome the limit and to reveal more information on biomedical samples. Optical properties of nanoparticles in a turbid medium, however, have remained difficult to measure precisely. In this paper, we investigate the scattering and absorbing properties of gold nanoparticles of varying diameter and different concentration in absorbing liquid phantoms of silica colloid, based on diffuse photometry. Diffuse reflectance patterns have been collected for each phantom with nanoparticles of different size and concentrations relative to base media. The results imply that ...

The feeling we have of our own body, sometimes called body image, is fundamental to self-awareness. However, by altering sensory input, the body image can be modified into impossible configurations. Can impossible movements of the body image be conjured solely via internally generated mechanisms, and, if so, do the structural characteristics of the body image modify to accommodate the new movements? We encouraged seven amputees with a vivid phantom arm to learn to perform a phantom wrist movement that defied normal anatomical constraints. Four reported success. Learning the impossible movement coincided in time with a profound change in the body image of the arm, including a sense of ownership and agency over a modified wrist joint. Remarkably, some previous movements and functional tasks involving the phantom arm became more difficult once the shift in body image had occurred. Crucially, these introspective reports were corroborated by robust empirical data from motor imagery tasks, about ...

Welcome to the official website of the worlds first Phantom Vibration Syndrome therapy? and information portal. Our goal is to educate people who suffer from these odd vibrations and to offer guidance and treatments for phantom vibration syndrome.. If you are visiting this website you are probably like the hundreds of thousands of people around the world who suffer from Phantom Vibration Syndrome. While some media and lobby-groups have downplayed the seriousness of PVS (Phantom Vibration Syndrome) more and more people are experiencing symptoms firsthand. Like most conditions and syndromes, PVS is thought to be a bit of the canary in the coalmine or the tip of the iceberg that is actually the start of something ominous if not dangerous to the well-being of our very genetic code and mental health.. On our website we offer resources and help for sufferers who are being adversely effected by the electromagnetic pollutants that are literally dumped into the air with virtually zero emissions ...

Welcome to the official website of the worlds first Phantom Vibration Syndrome therapy? and information portal. Our goal is to educate people who suffer from these odd vibrations and to offer guidance and treatments for phantom vibration syndrome.. If you are visiting this website you are probably like the hundreds of thousands of people around the world who suffer from Phantom Vibration Syndrome. While some media and lobby-groups have downplayed the seriousness of PVS (Phantom Vibration Syndrome) more and more people are experiencing symptoms firsthand. Like most conditions and syndromes, PVS is thought to be a bit of the canary in the coalmine or the tip of the iceberg that is actually the start of something ominous if not dangerous to the well-being of our very genetic code and mental health.. On our website we offer resources and help for sufferers who are being adversely effected by the electromagnetic pollutants that are literally dumped into the air with virtually zero emissions ...

Some people also experience tingling, pressure, stinging, burning, pain, itching or aching. Despite the comedic name, it can actually be really miserable and affect self esteem, confidence and mental health in some people.. Sometimes phantom rectum syndrome is found in patients who still have a rectum, but dont have it connected as they have had ostomy surgery or other operations to divert stool away from it. They may experience phantom rectum because of a build up of mucus in the rectum. But it is also experienced by those who have had the rectum and anus removed completely, this could be because of scar tissue, nerve damage or a psychological effect.. I am only a few weeks out of surgery but I definitely get the old phantom rectum symptoms, I really do think mine is my brain telling my body to do something it cant. For example, after a morning cup of coffee when you get that urge, I still get that, but there is nothing down there! I can only poo through my stoma, I have no rectum or anus ...

TY - JOUR. T1 - Somatotopical feedback versus non-somatotopical feedback for phantom digit sensation on amputees using electrotactile stimulation. AU - Zhang, Dingguo. AU - Xu, Heng. AU - Shull, Peter B.. AU - Liu, Jianrong. AU - Zhu, Xiangyang. PY - 2015/5/2. Y1 - 2015/5/2. N2 - Abstract Background: Transcutaneous electrical stimulation can provide amputees with tactile feedback for better manipulating an advanced prosthesis. In general, there are two ways to transfer the stimulus to the skin: somatotopical feedback (SF) that stimulates the phantom digit somatotopy on the stump and non-somatotopical feedback (NF) that stimulates other positions on the human body. Methods: To investigate the difference between SF and NF, electrotactile experiments were conducted on seven amputees. Electrical stimulation was applied via a complete phantom map to the residual limb (SF) and to the upper arm (NF) separately. The behavior results of discrimination accuracy and response time were used to examine: 1) ...

The purpose of this study was to develop, implement and evaluate a dedicated metal artefact reduction (MAR) method for flat-detector CT (FDCT). The algorithm uses the multidimensional raw data space to calculate surrogate attenuation values for the original metal traces in the raw data domain. The metal traces are detected automatically by a three-dimensional, threshold-based segmentation algorithm in an initial reconstructed image volume, based on twofold histogram information for calculating appropriate metal thresholds. These thresholds are combined with constrained morphological operations in the projection domain. A subsequent reconstruction of the modified raw data yields an artefact-reduced image volume that is further processed by a combining procedure that reinserts the missing metal information. For image quality assessment, measurements on semi- anthropomorphic phantoms containing metallic inserts were evaluated in terms of CT value accuracy, image noise and spatial resolution before ...

ABSTRACT. The purpose of this study was to compare the Pencil Beam (PB) with Monte Carlo (MC) calculated dosimetric results using phantoms for air cavity region. Measurements in Tough water phantom with air gaps were used to verify the calculated dose. The plane-parallel ionization chamber was moved from 2 mm to 20 mm behind air gap. Calculations were performed for various air gaps (1.0, 2.0, 3.0 and 4.0 cm) and field sizes (4.2 × 4.2, 6.0 × 6.0 and 9.8 × 9.8 cm2). The lateral missing tissue measurement was performed using the radiochromic RT-QA film. Dose difference between PB and chamber measurement near an air gap was greater for smaller field size, larger air gap thickness, and shallower depth behind air gap. As the distance from the phantom edge became shorter, the dose differences of the PB calculation and film measurement became larger. MC calculations were found within 3% agreement to the measured dose distributions. Our results demonstrate an excellent agreement between ionization ...

The paper investigates Second Harmonic Imaging (SHI) using Synthetic Aperture Sequential Beamforming (SASB). The investigation is made by an experimental Synthetic Aperture Real-time Ultrasound System (SARUS). A linear array transducer is used to scan 4 wires at the image depths of f22.5, 47.5, 72.5, 97.5g mm, respectively. Three different experiments are made using three different transmit foci at 10 mm, 25 mm and 50 mm. A 2-cycle sine wave with a center frequency of 5 MHz is used as the excitation. The SHI is achieved by using Pulse Inversion (PI) technique. The data received with and without PI from SARUS are beamformed using Dynamic Receive Focusing (DRF) and SASB by a Beamformation Toolbox. The Full Widths at Half Maximum (FWHM) in both the lateral and axial directions for these four wire targets using different imaging algorithms (DRF, DRF+SHI, SASB and SASB+SHI) are calculated and shown in the paper. The Full Width at One Tenth Maximum (FWOTM) is also investigated. By combining SASB and ...

The Bayesian penalized likelihood (BPL) algorithm Q.Clear (GE Healthcare) allows fully convergent iterative reconstruction that results in better image quality and quantitative accuracy, while limiting image noise. The present study aimed to optimize BPL reconstruction parameters for 18F-NaF PET/CT images and to determine the feasibility of 18F-NaF PET/CT image acquisition over shorter durations in clinical practice. A custom-designed thoracic spine phantom consisting of several inserts, soft tissue, normal spine, and metastatic bone tumor, was scanned using a Discovery MI PET/CT scanner (GE Healthcare). The phantom allows optional adjustment of activity distribution, tumor size, and attenuation. We reconstructed PET images using OSEM + PSF + TOF (2 iterations, 17 subsets, and a 4-mm Gaussian filter), BPL + TOF (β = 200 to 700), and scan durations of 30-120 s. Signal-to-noise ratios (SNR), contrast, and coefficients of variance (CV) as image quality indicators were calculated, whereas the quantitative

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I also wanted to say that I find comparing adoption to an amputation to be a fitting description of adoption in its current form but also very unfitting of how adoption should be. Phantom pains are pains felt in the mind when no real real pain-causing event is occuring. There are Psychological methods, such as the mirror method, used to trick the mind into being relieved of this pain. Adoptee pain is not phantom. It is very real with a very real pain-causing source. Our desire to know and to heal is currently placated with mirrors but this is entirely unfitting. Adoption law in its current form does indeed amputate the original family and tries to blot it out from existence (in 44 out of 50 states that is) when it should not. I am part of a small group of adoptees who has been permitted access to the knowledge of my original heritage. I am a direct descendant of Revolutionary War heros and the sojourners of the Mayflower--that BELONGS to me! and I belong to them; I am a part of the legacy that ...

I also wanted to say that I find comparing adoption to an amputation to be a fitting description of adoption in its current form but also very unfitting of how adoption should be. Phantom pains are pains felt in the mind when no real real pain-causing event is occuring. There are Psychological methods, such as the mirror method, used to trick the mind into being relieved of this pain. Adoptee pain is not phantom. It is very real with a very real pain-causing source. Our desire to know and to heal is currently placated with mirrors but this is entirely unfitting. Adoption law in its current form does indeed amputate the original family and tries to blot it out from existence (in 44 out of 50 states that is) when it should not. I am part of a small group of adoptees who has been permitted access to the knowledge of my original heritage. I am a direct descendant of Revolutionary War heros and the sojourners of the Mayflower--that BELONGS to me! and I belong to them; I am a part of the legacy that ...

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Phantom Quartz with natural mineral build up. Solid floating chlorite phantom within the quartz crystal. Self standing. under 2x1

Introduction: In radiotherapy treatment planning system (TPS), basic input is the data from computed tomography (CT) scan, which takes into account the effect of inhomogeneities in dose calculations. Measurement of CT numbers may be affected by scanner-specific parameters. Therefore, it is important to verify the effect of different CT scanning protocols on Hounsfield unit (HU) and its impact on dose calculation. This study was carried out to analyse the effect of different tube voltages on HU for various tissue substitutes in phantom and their dosimetric impact on dose calculation in TPS due to variation in HU-relative electron density (RED) calibration curves. Materials and Methods: HU for different density materials was obtained from CT images of the phantom acquired at various tube voltages. HU-RED calibration curves were drawn from CT images with various tissue substitutes acquired at different tube voltages used to quantify the error in dose calculation for different algorithms. Doses were

0049]Referring again FIG. 1, the image data generating unit 6 includes a projection data memory 61, an image processing unit 62, a subtraction process unit 63, a reconstruction processing unit 64 and a rendering process unit 65. The projection data memory 61 generates two dimensional (2D) projection data by successively storing projection data supplied from the projection data generating unit 4 in the X-ray detecting unit 3 into a self memory circuit. For instance, in a preliminary imaging mode, two of 2D projection data are generated through X-ray irradiations along the orthogonally crossed imaging directions θa and θb set up to the object 150, and the 2D projection data are stored into the memory circuit in the projection data memory 61. In an actual imaging mode, before administrating a contrast agent into an object 150, a plurality M of 2D projection data (hereinafter referred to as mask projection data) is generated through X-ray irradiations along the imaging direction θ1 through θM ...

article{c21f6689-6934-4c0b-8c77-17f94d2391f0, abstract = {Computed tomography (CT) is one of the most important modalities in a radiological department. This technique not only produces images that enable radiological reports with high diagnostic confidence, but it may also provide an elevated radiation dose to the patient. The radiation dose can be reduced by using advanced image reconstruction algorithms. This study was performed on a Brilliance iCT, equipped with iDose(4) iterative reconstruction and an iterative model-based reconstruction (IMR) method. The purpose was to investigate the effect of reduced slice thickness combined with an IMR method on image quality compared with standard slice thickness with iDose(4) reconstruction. The results of objective and subjective image quality evaluations showed that a thinner slice combined with IMR can improve the image quality and reduce partial volume artefacts compared with the standard slice thickness with iDose(4). In conclusion, IMR enables ...

In this paper, an augmented Lagrangian Uzawa iterative method is developed and analyzed for solving a class of double saddle-point systems with semidefinite (2,2) block. Convergence of the iterative method is proved under the assumption that the double saddle-point problem exists a unique solution. An application of the iterative method to the double saddle-point systems arising from the distributed Lagrange multiplier/fictitious domain (DLM/FD) finite element method for solving elliptic interface problems is also presented, in which the existence and uniqueness of the double saddle-point system is guaranteed by the analysis of the DLM/FD finite element method. Numerical experiments are conducted to validate the theoretical results and to study the performance of the proposed iterative method.

Purpose/Introduction: Use of brain PET studies in multicentre trials or as a quantitative imaging biomarker for (automated) differential diagnosis of neurogenerative diseases require harmonized quantitative image characteristics. In this study we explored the feasibility of developing a harmonizing performance standard for brain PET studies on state of the art PET/CT systems. Subjects & Methods: In this exploratory study 6 state of the art PET/CT systems were included: Philips Gemini TF, Ingenuity TF and digital Vereos systems, 2 Siemens Biograph mCTs and a GE 710. Only systems with EARL compliant (calibration and image quality) performances were included. A 30 min dynamic PET scan of the 3D Hoffmann brain phantom was acquired. The phantom was filled with an exact known FDG stock solution (aimed at 40 kBq/mL). Each scan was reconstructedusing various clinically relevant reconstruction settings. Depending on PET/CT system reconstruction settings were varied as follows: time of flight (TOF) ...

Electron tomography in the physical sciences has become a powerful tool for nanomaterial analysis. Recently, electron tomography is finding applications in more beam sensitive materials such as catalysts. For beam sensitive materials, the goal is to acquire the smallest number of images as possible but still maintain an accurate and high resolution 3-D reconstruction. Standard methods of 3D reconstruction, such as weighted back projection (WBP) and simultaneous iterative reconstruction technique (SIRT), are not equipped to handle this lack of information, and create significant blurring. This gives rise to a search for new methods of reconstruction. Two of the recent successful algorithms are the discrete algebraic reconstruction technique (DART) and total variation (TV) minimization within compressed sensing (CS). The DART algorithm uses ART and pairs it with the prior knowledge that there are only a small number (two or three) of different materials in the sample, each corresponding to a ...

Even though iterative reconstruction algorithms give very accurate results, their long computation time inhibits practical applications. The most computationally intensive steps of the algorithms used by the ASTRA research group are very well parallelizable. Modern GPU cores consist of many processing units and are optimized for operations also required during tomographic reconstructions. With the release of NVIDIA CUDA, GPUs became fully programmable. Our research is focused on maximizing parallelism in previously developed algorithms and developing new hardware platforms to allow for practical applications of iterative reconstruction algorithms.. ...

Constructing ultrasound statistical parametric images by using a sliding window is a widely adopted strategy for characterizing tissues. Deficiency in spatial resolution, the appearance of boundary artifacts, and the prerequisite data distribution limit the practicability of statistical parametric imaging. In this study, small-window entropy parametric imaging was proposed to overcome the above problems. Simulations and measurements of phantoms were executed to acquire backscattered radiofrequency (RF) signals, which were processed to explore the feasibility of small-window entropy imaging in detecting scatterer properties. To validate the ability of entropy imaging in tissue characterization, measurements of benign and malignant breast tumors were conducted (n = 63) to compare performances of conventional statistical parametric (based on Nakagami distribution) and entropy imaging by the receiver operating characteristic (ROC) curve analysis. The simulation and phantom results revealed that entropy

In todays Radiotherapy Treatment Planning, RTP, it is common to use Computed Tomography, CT, together with Magnetic Resonance Imaging, MRI, where CT provides electron density information and a geometrical reference, and where MRI provides superior soft tissue contrast. To sim- plify the workflow and improve treatment accuracy, research groups have demonstrated how to exclude CT and use a MRI-only approach. In this thesis, a method for spatial distortion analysis, ultimately enabling quality assurance, QA, of the spatial accuracy of MRI, was defined, tested and evaluated.. A phantom was built to cover the entire clinical Field Of View, FOV, and 6mm-diameter fluid filled paintball markers were placed in a well-defined geometrical pattern within the phantom, and used as positive contrast. The phantom was imaged with a 3D Fast Gradient Echo sequence and a 3D Fast Spin Echo sequence. The markers were identified in the image data by a MATLAB-algorithm, and the location of the center of mass was ...

Using an amorphous silicon (a-Si) EPID for transit dosimetry requires detailed characterization of its dosimetric response in a variety of conditions. In this study, a measurement-based model was developed to calibrate an a-Si EPID response to dose for transit dosimetry by comparison with a reference ionization chamber. The ionization chamber reference depth and the required additional buildup thickness for electronic portal imaging devices (EPID) transit dosimetry were determined. The combined effects of changes in radiation field size, phantom thickness, and the off-axis distance on EPID transit dosimetry were characterized. The effect of scattered radiation on out-of-field response was investigated for different field sizes and phantom thicknesses by evaluation of the differences in image profiles and in-water measured profiles. An algorithm was developed to automatically apply these corrections to EPID images based on the user-specified field size and phantom thickness. The average phantom ...

Objectives: This study aimed to measure the absorbed doses in selected organs for prospectively ECG-triggered coronary computed tomography angiography (CCTA) using five different generations CT scanners in a female adult anthropomorphic phantom and to estimate the effective dose (HE). Materials and Methods: Prospectively ECG-triggered CCTA was performed using five commercially available CT scanners: 64-detector-row single source CT (SSCT), 2 × 32-detector-row-dual source CT (DSCT), 2 × 64-detector-row DSCT and 320-detector-row SSCT scanners. Absorbed doses were measured in 34 organs using pre-calibrated optically stimulated luminescence dosimeters (OSLDs) placed inside a standard female adult anthropomorphic phantom. HE was calculated from the measured organ doses and compared to the HE derived from the air kerma-length product (PKL) using the conversion coefficient of 0.014 mSv_mGy-1_cm-1 for the chest region. Results: Both breasts and lungs received the highest radiation dose during CCTA ...

Introduction: To accomplish a further decrease in radiation dose for coronary CT angiography (CCTA), advances in iterative reconstruction (IR) algorithms are necessary. The purpose of the present study was to investigate the impact of a latest generation adaptive statistical IR algorithm (ASiR-V, GE Healthcare) on CCTA signal intensity, noise and image quality (IQ).. Methods: Sixty-five consecutive patients underwent clinically indicated CCTA using a latest generation 256-slice CT scanner (Revolution CT, GE Healthcare) and an ultra-low-dose CCTA protocol (i.e. a BMI-adapted tube current of 180-310 mA and tube voltage of 80-120 kVp). Datasets from each patient were reconstructed at different levels of ASiR-V (i.e. ASiR-V 0% [= filtered back projection, FBP], 20%, 40%, 60%, 80% and 100%). The signal intensity and noise (i.e. attenuation and its standard deviation [in HU]) were measured in each reconstruction by placing a region of interest in the aortic root as well as the proximal RCA and LMA. ...

This observer performance study assessed lesion detection in the computed tomography attenuation correction image, as would be produced for myocardial perfusion imaging over a tube current (mA) range. A static anthropomorphic chest phantom containing simulated pulmonary lesions was scanned using the four available mA values (1, 1.5, 2 and 2.5) on a GE Infinia Hawkeye 4. All other computed tomography acquisition parameters remained constant throughout. Twenty-seven cases showing zero to four lesions were produced for a free-response receiver-operating characteristic method. Image observations were completed using our novel web-based ROCView software under controlled conditions. The Jackknife alternative free-response receiver-operating characteristic (JAFROC) figure of merit was used for significance testing, wherein a difference in lesion detection performance was considered significant at P values less than 0.05. Twenty readers with varying computed tomography experience (0-24 years) evaluated ...

PURPOSE: To examine the effects of the reconstruction algorithm of magnitude images from multichannel diffusion MRI on fiber orientation estimation. THEORY AND METHODS: It is well established that the method used to combine signals from different coil elements in multichannel MRI can have an impact on the properties of the reconstructed magnitude image. Using a root-sum-of-squares approach results in a magnitude signal that follows an effective noncentral-χ distribution. As a result, the noise floor, the minimum measurable in the absence of any true signal, is elevated. This is particularly relevant for diffusion-weighted MRI, where the signal attenuation is of interest. RESULTS: In this study, we illustrate problems that such image reconstruction characteristics may cause in the estimation of fiber orientations, both for model-based and model-free approaches, when modern 32-channel coils are used. We further propose an alternative image reconstruction method that is based on sensitivity encoding

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Data Compression to Facilitate Remote Medical Analysis and Diagnosis | METHOD AND SYSTEM FOR CUFF-LESS BLOOD PRESSURE (BP) MEASUREMENT OF A SUBJECT | ABLATION TREATMENT DEVICE SENSOR | ESTIMATION AND DISPLAY FOR VECTOR DOPPLER IMAGING USING PLANE WAVE TRANSMISSIONS | ANALYSIS METHODS OF ULTRASOUND ECHO SIGNALS BASED ON STATISTICS OF SCATTERER DISTRIBUTIONS |

Objectives: The aim of this study was to assess the effect of a deep learning (DL)-based reconstruction algorithm on late gadolinium enhancement (LGE) image quality and to evaluate its influence on scar quantification. Methods: Sixty patients (46 ± 17 years, 50% male) with suspected or known cardiomyopathy underwent CMR. Short-axis LGE images were reconstructed using the conventional reconstruction and a DL network (DLRecon) with tunable noise reduction (NR) levels from 0 to 100%. Image quality of standard LGE images and DLRecon images with 75% NR was scored using a 5-point scale (poor to excellent). In 30 patients with LGE, scar size was quantified using thresholding techniques with different standard deviations (SD) above remote myocardium, and using full width at half maximum (FWHM) technique in images with varying NR levels. Results: DLRecon images were of higher quality than standard LGE images (subjective quality score 3.3 ± 0.5 vs. 3.6 ± 0.7, p , 0.001). Scar size increased with ...