Osmotic blood-brain barrier disruption. Computerized tomographic monitoring of chemotherapeutic agent delivery.

PubMed Central

Neuwelt, E A; Maravilla, K R; Frenkel, E P; Rapaport, S I; Hill, S A; Barnett, P A

1979-01-01

The present study describes a canine model of transient reversible blood-brain barrier disruption with hyperosmolar mannitol infusion into the internal carotid artery. Studies in this model show that osmotic blood-brain barrier disruption before intracarotid infusion of methotrexate results in markedly elevated (therapeutic) levels of drug in the ipsilateral cerebral hemisphere. Levels in the cerebrospinal fluid correlate poorly and inconsistently with brain levels. Computerized tomograms in this canine model provide a noninvasive monitor of the degree, time-course, and localization of osmotic blood-brain barrier disruption. Images PMID:457877

Tomographic imaging of the shallow crustal structure of the East Pacific Rise at 9 deg 30 min N

NASA Astrophysics Data System (ADS)

Toomey, Douglas R.; Solomon, Sean C.; Purdy, G. M.

1994-12-01

Compressional wave travel times from a seismic tomography experiment at 9 deg 30 min N on the East Pacific Rise are analyzed by a new tomographic method to determine the three-dimensional seismic velocity structure of the upper 2.5 km of oceanic crust within a 20 x 18 km area centered on the rise axis. The data comprise the travel times and associated uncertainties of 1459 compressional waves that have propagated above the axial magma chamber. A careful analysis of source and receiver parameters, in conjunction with an automated method of picking P wave onsets and assigning uncertainties, constrains the prior uncertainty in the data to 5 to 20 ms. The new tomographic method employs graph theory to estimate ray paths and travel times through strongly heterogeneous and densely parameterized seismic velocity models. The nonlinear inverse method uses a jumping strategy to minimize a functional that includes the penalty function, horizontal and vertical smoothing constraints, and prior model assumptions; all constraints applied to model perturbations are normalized to remove bias. We use the tomographic method to reject the null hypothesis that the axial seismic structure is two-dimensional. Three-dimensional models reveal a seismic structure that correlates well with cross- and along-axis variations in seafloor morphology, the location of the axial summit caldera, and the distribution of seafloor hydrothermal activity. The along-axis segmentation of the seismic structure above the axial magma chamber is consistent with the hypothesis that mantle-derived melt is preferentially injected midway along a locally linear segment of the rise and that the architecture of the crustal section is characterized by an en echelon series of elongate axial volcanoes approximately 10 km in length. The seismic data are compatible with a 300- to 500-m-thick thermal anomaly above a midcrustal melt lens; such an interpretation suggests that hydrothermal fluids may not have penetrated this region in the last 10(exp 3) years. Asymmetries in the seismic structure across the rise support the inferences that the thickness of seismic layer 2 and the average midcrustal temperature increase to the west of the rise axis. These anomalies may be the result of off-axis magmatism; alternatively, the asymmetric thermal anomaly may be the consequence of differences in the depth extent of hydrothermal cooling.

CMT for biomedical and other applications

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

Spanne, P.

This session includes two presentations describing applications for x-ray tomography using synchrotron radiation for biomedical uses and fluid flow modeling, and outlines advantages for using monoenergetic x-rays. Contrast mechanisms are briefly described and several graphs of absorbed doses and scattering of x-rays are included. Also presented are schematic diagrams of computerized tomographic instrumentation with camera head. A brief description of goals for a real time tomographic system and expected improvements to the system are described. Color photomicrographs of the Berea Sandstone and human bone are provided, as well as a 3-D microtomographic reconstruction of a human vertebra sample.

Tomographic imaging of transparent biological samples using the pyramid phase microscope

PubMed Central

Iglesias, Ignacio

2016-01-01

We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

Emission computerized axial tomography from multiple gamma-camera views using frequency filtering.

PubMed

Pelletier, J L; Milan, C; Touzery, C; Coitoux, P; Gailliard, P; Budinger, T F

1980-01-01

Emission computerized axial tomography is achievable in any nuclear medicine department from multiple gamma camera views. Data are collected by rotating the patient in front of the camera. A simple fast algorithm is implemented, known as the convolution technique: first the projection data are Fourier transformed and then an original filter designed for optimizing resolution and noise suppression is applied; finally the inverse transform of the latter operation is back-projected. This program, which can also take into account the attenuation for single photon events, was executed with good results on phantoms and patients. We think that it can be easily implemented for specific diagnostic problems.

Tomographic phase analysis to detect the site of accessory conduction pathway in Wolff-Parkinson-White syndrome

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

Nakajima, K.; Bunko, H.; Tada, A.

1984-01-01

Phase analysis has been applied to Wolff-Parkinson-White syndrome (WPW) to detect the site of accessory conduction pathway (ACP); however, there was a limitation to estimate the precise location of ACP by planar phase analysis. In this study, the authors applied phase analysis to gated blood pool tomography. Twelve patients with WPW who underwent epicardial mapping and surgical division of ACP were studied by both of gated emission computed tomography (GECT) and routine gated blood pool study (GBPS). The GBPS was performed with Tc-99m red blood cells in multiple projections; modified left anterior oblique, right anterior oblique and/or left lateral views.more » In GECT, short axial, horizontal and vertical long axial blood pool images were reconstructed. Phase analysis was performed using fundamental frequency of the Fourier transform in both GECT and GBPS images, and abnormal initial contractions on both the planar and tomographic phase analysis were compared with the location of surgically confirmed ACPs. In planar phase analysis, abnormal initial phase was identified in 7 out of 12 (58%) patients, while in tomographic phase analysis, the localization of ACP was predicted in 11 out of 12 (92%) patients. Tomographic phase analysis is superior to planar phase images in 8 out of 12 patients to estimate the location of ACP. Phase analysis by GECT can avoid overlap of blood pool in cardiac chambers and has advantage to identify the propagation of phase three-dimensionally. Tomographic phase analysis is a good adjunctive method for patients with WPW to estimate the site of ACP.« less

[The role of multidetector computer tomography in diagnosis of acute pancreatitis].

PubMed

Lohanikhina, K Iu; Hordiienko, K P; Kozarenko, T M

2014-10-01

With the objective to improve the diagnostic semiotics of an acute pancreatitis (AP) 35 patients were examined, using 64-cut computeric tomograph Lightspeed VCT (GE, USA) with intravenous augmentation in arterial and portal phases. Basing on analysis of the investigations conducted, using multidetector computeric tomography (MDCT), the AP semiotics was systematized, which is characteristic for oedematous and destructive forms, diagnosed in 19 (44.2%) and 16 (45.8%) patients, accordingly. The procedure for estimation of preservation of the organ functional capacity in pancreonecrosis pres- ence was elaborated, promoting rising of the method diagnostic efficacy by 5.3 - 9.4%.

The economic potential of CT scanners for hardwood sawmills

Treesearch

Donald G. Hodges; Walter C. Anderson; Charles W. McMillin

1990-01-01

Research has demonstrated that a knowledge of internal log defects prior to sawing could improve lumber value yields significantly. This study evaluated the potential economic returns from investments in computerized tomographic (CT) scanners to detect internal defects in hardwood logs at southern sawmills. The results indicate that such investments would be profitable...

Multidetector computerized tomographic fistulography in the evaluation of congenital branchial cleft fistulae and sinuses.

PubMed

Sun, Zhipeng; Fu, Kaiyuan; Zhang, Zuyan; Zhao, Yanping; Ma, Xuchen

2012-05-01

The aim of this study was to primarily investigate the usefulness of computerized tomographic (CT) fistulography in the diagnosis and management of branchial cleft fistulae and sinuses. Fifteen patients with confirmed branchial fistulae or sinuses who had undergone CT fistulography were included. The diagnoses were confirmed by clinical, radiologic, or histopathologic examinations. The internal openings, distribution, and neighboring relationship of the lesions presented by CT fistulography were analyzed to evaluate the usefulness in comparison with x-ray fistulography. Nine patients were diagnosed with first branchial fistulae or sinuses, 2 with second branchial fistulae, and 4 with third or fourth branchial fistulae. The presence and location of the lesions could be seen on x-ray fistulography. The distribution of the lesions, internal openings, and neighboring relationship with parotid gland, carotid sheath, and submandibular gland could be clearly demonstrated on CT cross-sectional or volume-rendering images. CT fistulography could provide valuable information and benefit surgical planning by demonstrating the courses of branchial anomalies in detail. Copyright © 2012 Elsevier Inc. All rights reserved.

[Evaluation of the risk of mediastinal or retroperitoneal injuries caused by dorso-lumbar pedicle screws].

PubMed

Hernigou, P; Germany, W

1998-09-01

Within an anatomical and a clinical study, the authors employed computerized tomographic scans to evaluate the risks of anterior surrounding tissues injuries during screw insertion. CT scans of 20 patients suffering from cardiac disease were reviewed retrospectively. Scans through the thoracic and lumbar spine were obtained using 6 mm slice thickness. These examinations were performed with intravenous contrast medium. Measurements of vessel diameters and distance of the soft tissues situated directly anterior to the spine were done. A retrospective study of 61 pedicle screws implanted for spine fractures evaluated the penetration of the anterior vertebral cordex with X rays and CT scans. Computerized tomographic scans of the thoracic and lumbar spine of the 20 patients in the control group confirmed proximity of the posterior mediastinal structures to the anterior vertebral cortex. Many structures of the posterior mediastinum were within five millimeters of the anterior vertebral cortex and thus were at risk: aorta, azygos vein, vena cava, parietal pleura and lungs. The theoretical risk of unrecognized screw penetrations evaluated on geometric shape of the anterior vertebral body is as high as 21 per cent when screw position is only seen with an antero posterior and a lateral X Ray. In the other group, computerized tomographic scans showed that 30 per cent of the implanted screws were outside the boundaries of the anterior thoracic spine. Two orthogonal incidences do not enable determination of whether the extremity of the screw is slightly outside the anterior cortex of the vertebral body. However the geometric shape of the anterior vertebral body enables peroperative definition of a safety zone on two orthogonal incidences. Even if a breach of a few millimeters of the anterior cortical boundaries of the vertebral body may not initially damage the adjacent soft-tissue structures, chronic irritation may result in late damages of these structures. The use of metallic markers and the respect of a safe vertebral zone on X Rays could guide the choice of the appropriate screw length.

Relations between age, weight, refractive error and eye shape by computerized tomography in children.

PubMed

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung; Moon, Yeon Sung

2007-09-01

To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths/axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years.

Relations between Age, Weight, Refractive Error and Eye Shape by Computerized Tomography in Children

PubMed Central

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung

2007-01-01

Purpose To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Methods Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Results Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths / axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. Conclusions The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years. PMID:17804923

Strut fracture and disc embolization of a Björk-Shiley mitral valve prosthesis: localization of embolized disc by computerized axial tomography.

PubMed

Larrieu, A J; Puglia, E; Allen, P

1982-08-01

The case of a patient who survived strut fracture and embolization of a Björk-Shiley mitral prosthetic disc is presented. Prompt surgical treatment was directly responsible for survival. In addition, computerized axial tomography of the abdomen aided in localizing and retrieving the embolized disc, which was lodged at the origin of the superior mesenteric artery. A review of similar case reports from the literature supports our conclusions that the development of acute heart failure and absent or muffled prosthetic heart sounds in a patient with a Björk-Shiley prosthetic heart valve inserted prior to 1978 should raise the possibility of valve dysfunction and lead to early reoperation.

X-ray tomographic image magnification process, system and apparatus therefor

DOEpatents

Kinney, J.H.; Bonse, U.K.; Johnson, Q.C.; Nichols, M.C.; Saroyan, R.A.; Massey, W.N.; Nusshardt, R.

1993-09-14

A computerized three-dimensional x-ray tomographic microscopy system is disclosed, comprising: (a) source means for providing a source of parallel x-ray beams, (b) staging means for staging and sequentially rotating a sample to be positioned in the path of the (c) x-ray image magnifier means positioned in the path of the beams downstream from the sample, (d) detecting means for detecting the beams after being passed through and magnified by the image magnifier means, and (e) computing means for analyzing values received from the detecting means, and converting the values into three-dimensional representations. Also disclosed is a process for magnifying an x-ray image, and apparatus therefor. 25 figures.

X-ray tomographic image magnification process, system and apparatus therefor

DOEpatents

Kinney, John H.; Bonse, Ulrich K.; Johnson, Quintin C.; Nichols, Monte C.; Saroyan, Ralph A.; Massey, Warren N.; Nusshardt, Rudolph

1993-01-01

A computerized three-dimensional x-ray tomographic microscopy system is disclosed, comprising: a) source means for providing a source of parallel x-ray beams, b) staging means for staging and sequentially rotating a sample to be positioned in the path of the c) x-ray image magnifier means positioned in the path of the beams downstream from the sample, d) detecting means for detecting the beams after being passed through and magnified by the image magnifier means, and e) computing means for analyzing values received from the detecting means, and converting the values into three-dimensional representations. Also disclosed is a process for magnifying an x-ray image, and apparatus therefor.

Experimental and theoretical analysis for improved microscope design of optical projection tomographic microscopy.

PubMed

Coe, Ryan L; Seibel, Eric J

2013-09-01

We present theoretical and experimental results of axial displacement of objects relative to a fixed condenser focal plane (FP) in optical projection tomographic microscopy (OPTM). OPTM produces three-dimensional, reconstructed images of single cells from two-dimensional projections. The cell rotates in a microcapillary to acquire projections from different perspectives where the objective FP is scanned through the cell while the condenser FP remains fixed at the center of the microcapillary. This work uses a combination of experimental and theoretical methods to improve the OPTM instrument design.

Procedures for Geometric Data Reduction in Solid Log Modelling

Treesearch

Luis G. Occeña; Wenzhen Chen; Daniel L. Schmoldt

1995-01-01

One of the difficulties in solid log modelling is working with huge data sets, such as those that come from computed axial tomographic imaging. Algorithmic procedures are described in this paper that have successfully reduced data without sacrificing modelling integrity.

Anthropometric and computerized tomographic measurements of lower extremity lean body mass.

PubMed

Buckley, D C; Kudsk, K A; Rose, B S; Fatzinger, P; Koetting, C A; Schlatter, M

1987-02-01

The loss of lean muscle mass is one of the hallmarks of protein-calorie malnutrition. Anthropometry is a standardized technique used to assess the response of muscle mass to nutrition therapy by quantifying the muscle and fat compartments. That technique does not accurately reflect actual limb composition, whereas computerized tomography does. Twenty lower extremities on randomly chosen men and women patients were evaluated by anthropometry and computerized tomography. Total area, muscle plus bone area, total volume, and muscle plus bone volume were correlated, using Heymsfield's equation and computerized tomography-generated areas. Anthropometrics overestimated total and muscle plus bone cross-sectional areas at almost every level. Anthropometry overestimated total area and total volume by 5% to 10% but overestimated muscle plus bone area and muscle plus bone volume by as much as 40%. Anthropometry, while easily performed and useful in large population groups for epidemiological studies, offers a poor assessment of lower extremity composition. On the other hand, computerized tomography is also easily performed and, while impractical for large population groups, does offer an accurate assessment of the lower extremity tissue compartments and is an instrument that might be used in research on lean muscle mass.

Measurement of radioactivity concentration in blood by using newly developed ToT LuAG-APD based small animal PET tomograph.

PubMed

Malik, Azhar H; Shimazoe, Kenji; Takahashi, Hiroyuki

2013-01-01

In order to obtain plasma time activity curve (PTAC), input function for almost all quantitative PET studies, patient blood is sampled manually from the artery or vein which has various drawbacks. Recently a novel compact Time over Threshold (ToT) based Pr:LuAG-APD animal PET tomograph is developed in our laboratory which has 10% energy resolution, 4.2 ns time resolution and 1.76 mm spatial resolution. The measured value of spatial resolution shows much promise for imaging the blood vascular, i.e; artery of diameter 2.3-2.4mm, and hence, to measure PTAC for quantitative PET studies. To find the measurement time required to obtain reasonable counts for image reconstruction, the most important parameter is the sensitivity of the system. Usually small animal PET systems are characterized by using a point source in air. We used Electron Gamma Shower 5 (EGS5) code to simulate a point source at different positions inside the sensitive volume of tomograph and the axial and radial variations in the sensitivity are studied in air and phantom equivalent water cylinder. An average sensitivity difference of 34% in axial direction and 24.6% in radial direction is observed when point source is displaced inside water cylinder instead of air.

Coping with Memory Loss

MedlinePlus

... either using computerized axial tomography (CAT) scans or magnetic resonance imaging (MRI) – can help to identify strokes and tumors, which can sometimes cause memory loss. “The goal is to rule out factors ...

PubMed Central

Laplante, L; Everett, J

1992-01-01

Many attempts to isolate a dysfunctional site in the brain of schizophrenic patients have converged in a neuropathological conception of the disease based on frontal lobe hypoactivity. Recent data from studies using cytoarchitectony, computerized tomographic scans, cerebral regional blood flow, smooth pursuit eye movements and neuropsychological assessments are discussed. Current data on the hypofrontality hypothesis in schizophrenia seem to suggest an associationist rather than a localisationist perspective of the disorder. PMID:1489762

Ultrafast CT scanning of an oak log for internal defects

Treesearch

Francis G. Wagner; Fred W. Taylor; Douglas S. Ladd; Charles W. McMillin; Fredrick L. Roder

1989-01-01

Detecting internal defects in sawlogs and veneer logs with computerized tomographic (CT) scanning is possible, but has been impractical due to the long scanning time required. This research investigated a new scanner able to acquire 34 cross-sectional log scans per second. This scanning rate translates to a linear log feed rate of 85 feet (25.91 m) per minute at one...

Can axial-based nodal size criteria be used in other imaging planes to accurately determine "enlarged" head and neck lymph nodes?

PubMed

Bartlett, Eric S; Walters, Thomas D; Yu, Eugene

2013-01-01

Objective. We evaluate if axial-based lymph node size criteria can be applied to coronal and sagittal planes. Methods. Fifty pretreatment computed tomographic (CT) neck exams were evaluated in patients with head and neck squamous cell carcinoma (SCCa) and neck lymphadenopathy. Axial-based size criteria were applied to all 3 imaging planes, measured, and classified as "enlarged" if equal to or exceeding size criteria. Results. 222 lymph nodes were "enlarged" in one imaging plane; however, 53.2% (118/222) of these were "enlarged" in all 3 planes. Classification concordance between axial versus coronal/sagittal planes was poor (kappa = -0.09 and -0.07, resp., P < 0.05). The McNemar test showed systematic misclassification when comparing axial versus coronal (P < 0.001) and axial versus sagittal (P < 0.001) planes. Conclusion. Classification of "enlarged" lymph nodes differs between axial versus coronal/sagittal imaging planes when axial-based nodal size criteria are applied independently to all three imaging planes, and exclusively used without other morphologic nodal data.

Can Axial-Based Nodal Size Criteria Be Used in Other Imaging Planes to Accurately Determine “Enlarged” Head and Neck Lymph Nodes?

PubMed Central

Bartlett, Eric S.; Walters, Thomas D.; Yu, Eugene

2013-01-01

Objective. We evaluate if axial-based lymph node size criteria can be applied to coronal and sagittal planes. Methods. Fifty pretreatment computed tomographic (CT) neck exams were evaluated in patients with head and neck squamous cell carcinoma (SCCa) and neck lymphadenopathy. Axial-based size criteria were applied to all 3 imaging planes, measured, and classified as “enlarged” if equal to or exceeding size criteria. Results. 222 lymph nodes were “enlarged” in one imaging plane; however, 53.2% (118/222) of these were “enlarged” in all 3 planes. Classification concordance between axial versus coronal/sagittal planes was poor (kappa = −0.09 and −0.07, resp., P < 0.05). The McNemar test showed systematic misclassification when comparing axial versus coronal (P < 0.001) and axial versus sagittal (P < 0.001) planes. Conclusion. Classification of “enlarged” lymph nodes differs between axial versus coronal/sagittal imaging planes when axial-based nodal size criteria are applied independently to all three imaging planes, and exclusively used without other morphologic nodal data. PMID:23984099

Nanometer resolution optical coherence tomography using broad bandwidth XUV and soft x-ray radiation

DOE PAGES

Fuchs, Silvio; Rödel, Christian; Blinne, Alexander; ...

2016-02-10

Optical coherence tomography (OCT) is a non-invasive technique for cross-sectional imaging. It is particularly advantageous for applications where conventional microscopy is not able to image deeper layers of samples in a reasonable time, e.g. in fast moving, deeper lying structures. However, at infrared and optical wavelengths, which are commonly used, the axial resolution of OCT is limited to about 1 μm, even if the bandwidth of the light covers a wide spectral range. Here, we present extreme ultraviolet coherence tomography (XCT) and thus introduce a new technique for non-invasive cross-sectional imaging of nanometer structures. XCT exploits the nanometerscale coherence lengthsmore » corresponding to the spectral transmission windows of, e.g., silicon samples. The axial resolution of coherence tomography is thus improved from micrometers to a few nanometers. Tomographic imaging with an axial resolution better than 18 nm is demonstrated for layer-type nanostructures buried in a silicon substrate. Using wavelengths in the water transmission window, nanometer-scale layers of platinum are retrieved with a resolution better than 8 nm. As a result, XCT as a nondestructive method for sub-surface tomographic imaging holds promise for several applications in semiconductor metrology and imaging in the water window.« less

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance

Science.gov Websites

Radiopharmaceuticals, DOE Technical Report, 1977 Emission Computed Tomography: A New Technique for the Quantitative Extending the Power of Nuclear Magnetic Resonance Techniques Magnetic Resonance Imaging Research Top Some

Computerized tomographic determination of spinal bone mineral content

NASA Technical Reports Server (NTRS)

Cann, C. E.; Genant, H. K.

1980-01-01

The aims of the study were three-fold: to determine the magnitude of vertebral cancellous mineral loss in normal subjects during bedrest, to compare this loss with calcium balance and mineral loss in peripheral bones, and to use the vertebral measurements as an evaluative criterion for the C12MDP treatment and compare it with other methods. The methods used are described and the results from 14 subjects are presented.

Computed tomographic atlas for the new international lymph node map for lung cancer: A radiation oncologist perspective.

PubMed

Lynch, Rod; Pitson, Graham; Ball, David; Claude, Line; Sarrut, David

2013-01-01

To develop a reproducible definition for each mediastinal lymph node station based on the new TNM classification for lung cancer. This paper proposes an atlas using the new international lymph node map used in the seventh edition of the TNM classification for lung cancer. Four radiation oncologists and 1 diagnostic radiologist were involved in the project to put forward a reproducible radiologic description for the lung lymph node stations. The International Association for the Study of Lung Cancer lymph node definitions for stations 1 to 11 have been described and illustrated on axial computed tomographic scan images using a certified radiotherapy planning system. This atlas will assist both diagnostic radiologists and radiation oncologists in accurately defining the lymph node stations on computed tomographic scan in patients diagnosed with lung cancer. Copyright © 2013 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Assessment of Severity of Ovine Smoke Inhalation Injury by Analysis of Computed Tomographic Scans

DTIC Science & Technology

2003-09-01

Computerized analysis of three- dimensional reconstructed scans was also performed, based on Hounsfield unit ranges: hyperinflated, 1,000 to 900; normal...the interactive segmentation function of the software. The pulmonary parenchyma was separated into four regions based on the Hounsfield unit (HU...SII) severity. Methods: Twenty anesthetized sheep underwent graded SII: group I, no smoke; group II, 5 smoke units ; group III, 10 units ; and group IV

Wavelength scanning digital interference holography for high-resolution ophthalmic imaging

NASA Astrophysics Data System (ADS)

Potcoava, Mariana C.; Kim, M. K.; Kay, Christine N.

2009-02-01

An improved digital interference holography (DIH) technique suitable for fundus images is proposed. This technique incorporates a dispersion compensation algorithm to compensate for the unknown axial length of the eye. Using this instrument we acquired successfully tomographic fundus images in human eye with narrow axial resolution less than 5μm. The optic nerve head together with the surrounding retinal vasculature were constructed. We were able to quantify a depth of 84μm between the retinal fiber and the retinal pigmented epithelium layers. DIH provides high resolution 3D information which could potentially aid in guiding glaucoma diagnosis and treatment.

Digital enhancement of computerized axial tomograms

NASA Technical Reports Server (NTRS)

Roberts, E., Jr.

1978-01-01

A systematic evaluation was conducted of certain digital image enhancement techniques performed in image space. Three types of images were used, computer generated phantoms, tomograms of a synthetic phantom, and axial tomograms of human anatomy containing images of lesions, artificially introduced into the tomograms. Several types of smoothing, sharpening, and histogram modification were explored. It was concluded that the most useful enhancement techniques are a selective smoothing of singular picture elements, combined with contrast manipulation. The most useful tool in applying these techniques is the gray-scale histogram.

Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator

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

Andersson, P., E-mail: peter.andersson@physics.uu.se; Andersson-Sunden, E.; Sjöstrand, H.

2014-08-01

In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the time-averaged void distribution in these loops. Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantagemore » of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed. In this article, three axially symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm, and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper. Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020, and 0.022 cm{sup −1}, solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.« less

Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator.

PubMed

Andersson, P; Andersson-Sunden, E; Sjöstrand, H; Jacobsson-Svärd, S

2014-08-01

In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the time-averaged void distribution in these loops. Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed. In this article, three axially symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm, and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper. Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020, and 0.022 cm(-1), solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.

Research on ionospheric tomography based on variable pixel height

NASA Astrophysics Data System (ADS)

Zheng, Dunyong; Li, Peiqing; He, Jie; Hu, Wusheng; Li, Chaokui

2016-05-01

A novel ionospheric tomography technique based on variable pixel height was developed for the tomographic reconstruction of the ionospheric electron density distribution. The method considers the height of each pixel as an unknown variable, which is retrieved during the inversion process together with the electron density values. In contrast to conventional computerized ionospheric tomography (CIT), which parameterizes the model with a fixed pixel height, the variable-pixel-height computerized ionospheric tomography (VHCIT) model applies a disturbance to the height of each pixel. In comparison with conventional CIT models, the VHCIT technique achieved superior results in a numerical simulation. A careful validation of the reliability and superiority of VHCIT was performed. According to the results of the statistical analysis of the average root mean square errors, the proposed model offers an improvement by 15% compared with conventional CIT models.

Technological Advances in the Study of Reading: An Introduction.

ERIC Educational Resources Information Center

Henk, William A.

1991-01-01

Describes the purpose and functional operation of new computer-driven technologies such as computerized axial tomography, positron emissions transaxial tomography, regional cerebral blood flow monitoring, magnetic resonance imaging, and brain electrical activity mapping. Outlines their current contribution to the knowledge base. Speculates on the…

Root elongation against a constant force: experiment with a computerized feedback-controlled device

NASA Technical Reports Server (NTRS)

Kuzeja, P. S.; Lintilhac, P. M.; Wei, C.

2001-01-01

Axial force was applied to the root tip of corn (Zea mays L. cv. Merit) seedlings using a computerized, feedback-controlled mechanical device. The system's feedback capability allowed continuous control of a constant tip load, and the attached displacement transducer provided the time course of root elongation. Loads up to 7.5 g decreased the root elongation rate by 0.13 mm h-1 g-1, but loads 7.5 to 17.5 g decreased the growth rate by only 0.04 mm h-1 g-1. Loads higher than 18 g stopped root elongation completely. Measurement of the cross-sectional areas of the root tips indicated that the 18 g load had applied about 0.98 MPa of axial pressure to the root, thereby exceeding the root's ability to respond with increased turgor pressure. Recorded time-lapse images of loaded roots showed that radial thickening (swelling) occurred behind the root cap, whose cross-sectional area increased with tip load.

Comparison of the Multidetector-row Computed Tomographic Angiography Axial and Coronal Planes' Usefulness for Detecting Thoracodorsal Artery Perforators

PubMed Central

Kim, Jong Gyu

2012-01-01

Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels. PMID:22872839

Field-portable lensfree tomographic microscope†

PubMed Central

Isikman, Serhan O.; Bishara, Waheb; Sikora, Uzair; Yaglidere, Oguzhan; Yeah, John; Ozcan, Aydogan

2011-01-01

We present a field-portable lensfree tomographic microscope, which can achieve sectional imaging of a large volume (~20 mm3) on a chip with an axial resolution of <7 μm. In this compact tomographic imaging platform (weighing only ~110 grams), 24 light-emitting diodes (LEDs) that are each butt-coupled to a fibre-optic waveguide are controlled through a cost-effective micro-processor to sequentially illuminate the sample from different angles to record lensfree holograms of the sample that is placed on the top of a digital sensor array. In order to generate pixel super-resolved (SR) lensfree holograms and hence digitally improve the achievable lateral resolution, multiple sub-pixel shifted holograms are recorded at each illumination angle by electromagnetically actuating the fibre-optic waveguides using compact coils and magnets. These SR projection holograms obtained over an angular range of ~50° are rapidly reconstructed to yield projection images of the sample, which can then be back-projected to compute tomograms of the objects on the sensor-chip. The performance of this compact and light-weight lensfree tomographic microscope is validated by imaging micro-beads of different dimensions as well as a Hymenolepis nana egg, which is an infectious parasitic flatworm. Achieving a decent three-dimensional spatial resolution, this field-portable on-chip optical tomographic microscope might provide a useful toolset for telemedicine and high-throughput imaging applications in resource-poor settings. PMID:21573311

[Prostatic abscess. Contribution of the x-ray computed tomography. Apropos of a case].

PubMed

Husain, A; Touzard, D

1988-01-01

We reported a case of prostatic abscess due to staphylococeus aureus developed in a chronic alcoholic patient. The clinical symptoms and signs were largely masked by prior antibiotic therapy. Computed axial tomographic scanning of the pelvis made the diagnosis and demonstrated the resolution of the prostatic abscess following antibiotic therapy and spontaneous rupture to the urethra.

Digital enhancement of computerized axial tomograms

NASA Technical Reports Server (NTRS)

Roberts, E., Jr.

1978-01-01

A systematic evaluation has been conducted of certain digital image enhancement techniques performed in image space. Three types of images have been used, computer generated phantoms, tomograms of a synthetic phantom, and axial tomograms of human anatomy containing images of lesions, artificially introduced into the tomograms. Several types of smoothing, sharpening, and histogram modification have been explored. It has been concluded that the most useful enhancement techniques are a selective smoothing of singular picture elements, combined with contrast manipulation. The most useful tool in applying these techniques is the gray-scale histogram.

An Analysis of the Need for a Whole-Body CT Scanner at US Darnall Army Community Hospital

DTIC Science & Technology

1980-05-01

TASK IWORK UNIT ELEMENT NO. I NO.JC NO. rSSION NO. Ij6T’,WAM ’"Aa1W% A WHOLE BODY CT SCANNER AT DARNALL ARMY COMUNITY HOSPITAL 16PTR3OAL tUTHOR(S)* a...computerized axial tomography or CT. Computerized tomography experiments "were conducted by Godfrey Hounsfield at Central Research Laboratories, EMI, Ltd. in...remained the same, with clinical and nursing unit facilities to support a one division post. Presently, Fort Hood is the home of the III US Army Corps, the

Field-portable lensfree tomographic microscope.

PubMed

Isikman, Serhan O; Bishara, Waheb; Sikora, Uzair; Yaglidere, Oguzhan; Yeah, John; Ozcan, Aydogan

2011-07-07

We present a field-portable lensfree tomographic microscope, which can achieve sectional imaging of a large volume (∼20 mm(3)) on a chip with an axial resolution of <7 μm. In this compact tomographic imaging platform (weighing only ∼110 grams), 24 light-emitting diodes (LEDs) that are each butt-coupled to a fibre-optic waveguide are controlled through a cost-effective micro-processor to sequentially illuminate the sample from different angles to record lensfree holograms of the sample that is placed on the top of a digital sensor array. In order to generate pixel super-resolved (SR) lensfree holograms and hence digitally improve the achievable lateral resolution, multiple sub-pixel shifted holograms are recorded at each illumination angle by electromagnetically actuating the fibre-optic waveguides using compact coils and magnets. These SR projection holograms obtained over an angular range of ±50° are rapidly reconstructed to yield projection images of the sample, which can then be back-projected to compute tomograms of the objects on the sensor-chip. The performance of this compact and light-weight lensfree tomographic microscope is validated by imaging micro-beads of different dimensions as well as a Hymenolepis nana egg, which is an infectious parasitic flatworm. Achieving a decent three-dimensional spatial resolution, this field-portable on-chip optical tomographic microscope might provide a useful toolset for telemedicine and high-throughput imaging applications in resource-poor settings. This journal is © The Royal Society of Chemistry 2011

Synthetic aperture tomographic phase microscopy for 3D imaging of live cells in translational motion

PubMed Central

Lue, Niyom; Choi, Wonshik; Popescu, Gabriel; Badizadegan, Kamran; Dasari, Ramachandra R.; Feld, Michael S.

2009-01-01

We present a technique for 3D imaging of live cells in translational motion without need of axial scanning of objective lens. A set of transmitted electric field images of cells at successive points of transverse translation is taken with a focused beam illumination. Based on Hyugens’ principle, angular plane waves are synthesized from E-field images of a focused beam. For a set of synthesized angular plane waves, we apply a filtered back-projection algorithm and obtain 3D maps of refractive index of live cells. This technique, which we refer to as synthetic aperture tomographic phase microscopy, can potentially be combined with flow cytometry or microfluidic devices, and will enable high throughput acquisition of quantitative refractive index data from large numbers of cells. PMID:18825263

Rapid and high-resolution imaging of human liver specimens by full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhu, Yue; Gao, Wanrong; Zhou, Yuan; Guo, Yingcheng; Guo, Feng; He, Yong

2015-11-01

We report rapid and high-resolution tomographic en face imaging of human liver specimens by full-field optical coherence tomography (FF-OCT). First, the arrangement of the FF-OCT system was described and the performance of the system was measured. The measured axial and lateral resolutions of the system are 0.8 and 0.9 μm, respectively. The system has a sensitivity of ˜60 dB and can achieve an imaging rate of 7 fps and a penetration depth of ˜80 μm. The histological structures of normal liver can be seen clearly in the en face tomographic images, including central veins, cords of hepatocytes separated by sinusoidal spaces, and portal area (portal vein, the hepatic arteriole, and the bile duct). A wide variety of histological subtypes of hepatocellular carcinoma was observed in en face tomographic images, revealing notable cancerous features, including the nuclear atypia (enlarged convoluted nuclei), the polygonal tumor cells with obvious resemblance to hepatocytes with enlarged nuclei. In addition, thicker fibrous bands, which make the cytoplasmic plump vesicular nuclei indistinct, were also seen in the images. Finally, comparison between the portal vein in a normal specimen versus that seen in the rare type of cholangiocarcinoma was made. The results show that the cholangiocarcinoma presents with a blurred pattern of portal vein in the lateral direction and an aggregated distribution in the axial direction; the surrounding sinusoidal spaces and nuclei of cholangiocarcinoma are absent. The findings in this work may be used as additional signs of liver cancer or cholangiocarcinoma, demonstrating capacity of FF-OCT device for early cancer diagnosis and many other tumor-related studies in biopsy.

An Overview of Integrated Logistic Support in Medical Material Programs.

DTIC Science & Technology

1980-12-01

OF MEDICAL INTEGRATED LOGISTIC SUPPORT ----------------- 7 B. PROBLEM DEFINITION AND OBJECTIVE ------------ 9 C. GENERAL APPROACH AND METHODOLOGY...SYSTEM ---------------------- 61 C. GENERAL CONCLUSIONS ------------------------- 63 D. RECOMMENDATIONS ----------------------------- 73 E. CONCLUSION...21 Technological advancement has caused major changes in medicine and dentistry in the last several decades. Inten- sive care units, computerized axial

Initial studies using the RatCAP conscious animal PET tomograph

NASA Astrophysics Data System (ADS)

Woody, C.; Vaska, P.; Schlyer, D.; Pratte, J.-F.; Junnarkar, S.; Park, S.-J.; Stoll, S.; Purschke, M.; Southekal, S.; Kriplani, A.; Krishnamoorthy, S.; Maramraju, S.; Lee, D.; Schiffer, W.; Dewey, S.; Neill, J.; Kandasamy, A.; O'Connor, P.; Radeka, V.; Fontaine, R.; Lecomte, R.

2007-02-01

The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4×8 array of 2.2×2.2×5 mm 3 LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of ˜14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using 18F-FDG and 11C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP.

TomoPhantom, a software package to generate 2D-4D analytical phantoms for CT image reconstruction algorithm benchmarks

NASA Astrophysics Data System (ADS)

Kazantsev, Daniil; Pickalov, Valery; Nagella, Srikanth; Pasca, Edoardo; Withers, Philip J.

2018-01-01

In the field of computerized tomographic imaging, many novel reconstruction techniques are routinely tested using simplistic numerical phantoms, e.g. the well-known Shepp-Logan phantom. These phantoms cannot sufficiently cover the broad spectrum of applications in CT imaging where, for instance, smooth or piecewise-smooth 3D objects are common. TomoPhantom provides quick access to an external library of modular analytical 2D/3D phantoms with temporal extensions. In TomoPhantom, quite complex phantoms can be built using additive combinations of geometrical objects, such as, Gaussians, parabolas, cones, ellipses, rectangles and volumetric extensions of them. Newly designed phantoms are better suited for benchmarking and testing of different image processing techniques. Specifically, tomographic reconstruction algorithms which employ 2D and 3D scanning geometries, can be rigorously analyzed using the software. TomoPhantom also provides a capability of obtaining analytical tomographic projections which further extends the applicability of software towards more realistic, free from the "inverse crime" testing. All core modules of the package are written in the C-OpenMP language and wrappers for Python and MATLAB are provided to enable easy access. Due to C-based multi-threaded implementation, volumetric phantoms of high spatial resolution can be obtained with computational efficiency.

Computed tomographic (CT) neuroradiological evaluation of intra-axial and extra-axial lesions: a receiver operating characteristic (ROC) study of film and 1K workstation

NASA Astrophysics Data System (ADS)

El-Saden, Suzie; Hademenos, George J.; Zhu, Wei; Sayre, James W.; Glenn, Brad; Steidler, Jim; Kode, L.; King, Brian; Quinones, Diana; Valentino, Daniel J.; Bentsen, John R.

1995-04-01

Digital display workstations are now commonly used for cross-sectional image viewing; however, few receiver operating characteristic (ROC) studies have been performed to evaluate the diagnostic efficiency of hard copy versus a workstation display for neuroradiology applications. We have performed an ROC study of film and 1K workstation based on the diagnostic performance of neuroradiology fellows to detect subtle intra- axial (high density (HD) and low density (LD)) and extra-axial (fluid, blood) lesions presented on computed tomographic (CT) images. An ROC analysis of the interpretation of approximately 200 CT images (1/2 normals and 1/2 abnormals) was performed by five experienced observers. The total number of abnormal images were equally divided among the three represented types of lesions (HD, LD, and extra-axial lesions). The images comprising the extra-axial lesion group were further subdivided into the following three distinct types: subdural hemorrhage, subarachnoid hemorrhage, and epidural hemorrhage. A fraction of the abnormal images were represented by more than one type of lesion, e.g., one abnormal image could contain both a HD and LD lesion. The digitized CT images were separated into four groups and read on the standard light box and a 1K workstation monitor equipped with simple image processing functions. Confidence ratings were scaled on a range from 0 (least confident) to 4 (most confident). Reader order sequences were randomized for each reader and for each modality. Each observer read from a total of eight different groups with a four-week intermission following the fourth group. The randomly assigned image number, lesion type and approximate location, incidental findings and comments, and confidence ratings were reported in individual worksheets for each image. ROC curves that were generated and analyzed for the various subgroups are presented in addition to the overall generalized jackknifed estimates of the grouped data. Also, 95% confidence intervals are presented for the differences in the area under the ROC curves. Although there were no statistically significant differences in the diagnostic accuracy between the original CT slice with HD and LD lesions viewed on the light box and on the 1K display workstation, the observers tended to record extra- axial lesions more frequently and with more confidence on the 1K display in comparison to the light box primarily due to the added advantage of adjusting the display window levels.

The influence of the periodontal biotype on peri-implant tissues around immediate implants with and without xenografts. Clinical and micro-computerized tomographic study in small Beagle dogs.

PubMed

Maia, Luciana P; Reino, Danilo M; Muglia, Valdir A; de Souza, Sérgio L S; Palioto, Daniela B; Novaes, Arthur B

2015-01-01

Soft tissues and buccal bone plate remodeling after immediate implantation in sockets with thin buccal bone, using the flapless approach with or without bone graft into the buccal gap, was compared between sites with thin and normal gingiva. Eight dogs had the gingiva of one side of the mandible thinned, the mandibular premolars were extracted without flaps, and 4 implants were installed in each side, positioned 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). Buccal bone thickness (BBT), thickness of keratinized tissue (TKT), alveolar thickness (AT), gingival recession (GR), and probing depth (PD) were clinically evaluated. Within 12 weeks the dogs were sacrificed and the samples were analyzed by micro-computerized tomography. A thin BBT was observed in all the dogs. The presurgical procedures reduced TKT in the test group, with minimal changes of the AT. There were no statistically significant differences among the groups for the clinical parameters and the tomographic analysis showed similar linear and tri-dimensional bone reduction in all the groups. The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The decrease in gingival thickness or the addition of a biomaterial in the gap did not influence the results. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Two cases of severe eye and cranial injuries due to firework explosions].

PubMed

Saunte, J P; Trojaborg, N S; Nielsen, O A; Thygesen, J

1999-12-20

Two patients who sustained serious facial, cranial and eye trauma secondary to recreational fireworks injuries are reported. Initial assessment included axial and coronary computerized tomography, control of haemorrhage, debridement of wound and brain, and in one patient bilateral excenteration of the globe. Both patients suffered from intracranial haemorrhage, but both recovered without severe neurological sequelae.

Usefulness of axial planes of helical computed tomography for diagnosis of pancreaticobiliary maljunction in early infants with negative findings on magnetic resonance cholangiopancreatography.

PubMed

Okada, Tadao; Sasaki, Fumiaki; Honda, Shouhei; Naitou, Satsuki; Onodera, Yuya; Todo, Satoru

2008-03-01

Magnetic resonance cholangiopancreatography (MRCP) is not sufficient to detect pancreaticobiliary maljunction (PBM) in young infants because the main pancreatic duct is not visualized and respiratory artifacts occur. To our knowledge, there are no reports highlighting the diagnostic accuracy of evaluation using the axial planes of helical computed tomographic (CT) scanning with contrast medium instead of 3-dimensional (3D) reconstruction. The aim of this study was to describe our experience and the characteristics of 3 children with PBM diagnosed using the axial planes of helical CT with contrast medium, although they showed negative findings of PBM by MRCP, instead of 3D reconstruction. Three patients aged from 1 month to 3 years were diagnosed with PBM using the axial planes of helical CT with contrast medium though MRCP could not show the common channel and/or the entrance of the common channel into the duodenum. In all 3 patients, PBM of the common channel was not revealed by MRCP. On the other hand, axial planes of contrast-enhanced helical CT scans showed PBM clearly. Our experience suggests that axial planes of the contrast-enhanced helical CT scan comprise an accurate tool for the diagnosis of fusiform-type PBM and could replace MRCP in younger children. Further studies are necessary for better assessment of the potential advantages and pitfalls of this modality.

Large depth high-precision FMCW tomography using a distributed feedback laser array

NASA Astrophysics Data System (ADS)

DiLazaro, Thomas; Nehmetallah, George

2018-02-01

Swept-source optical coherence tomography (SS-OCT) has been widely employed in the medical industry for the high resolution imaging of subsurface biological structures. SS-OCT typically exhibits axial resolutions on the order of tens of microns at speeds of hundreds of kilohertz. Using the same coherent heterodyne detection technique, frequency modulated continuous wave (FMCW) ladar has been used for highly precise ranging for distances up to kilometers. Distributed feedback lasers (DFBs) have been used as a simple and inexpensive source for FMCW ranging. Here, we use a bandwidth-combined DFB array for sub-surface volume imaging at a 27 μm axial resolution over meters of distance. 2D and 3D tomographic images of several semi-transparent and diffuse objects at distances up to 10 m will be presented.

Computerized system for translating a torch head

NASA Technical Reports Server (NTRS)

Wall, W. A., Jr.; Ives, R. E.; Bruce, M. M., Jr.; Pryor, P. P., Jr.; Gard, L. H. (Inventor)

1978-01-01

The system provides a constant travel speed along a contoured workpiece. It has a driven skate characterized by an elongated bed, with a pair of independently pivoted trucks connected to the bed for support. The trucks are mounted on a contoured track of arbitrary configuration in a mutually spaced relation. An axially extensible torch head manipulator arm is mounted on the bed of the carriage and projects perpendicular from the midportion. The torch head is mounted at its distal end. A real-time computerized control drive subsystem is used to advance the skate along the track of a variable rate for maintaining a constant speed for the torch head tip, and to position the torch axis relative to a preset angle to the workpiece.

High-Resolution Imaging of Axial Volcano, Juan de Fuca ridge.

NASA Astrophysics Data System (ADS)

Arnulf, A. F.; Harding, A. J.; Kent, G. M.

2014-12-01

To date, seismic experiments have been key in our understanding of the internal structure of volcanic systems. However, most experiments, especially subaerial-based, are often restricted to refraction geometries with limited numbers of sources and receivers, and employ smoothing constraints required by tomographic inversions that produce smoothed and blurry images with spatial resolutions well below the length scale of important features that define these magmatic systems. Taking advantage of the high density of sources and receivers from multichannel seismic (MCS) data should, in principle, allow detailed images of velocity and reflectivity to be recovered. Unfortunately, the depth of mid-ocean ridges has the detrimental effect of concealing critical velocity information behind the seafloor reflection, preventing first arrival travel-time tomographic approaches from imaging the shallowest and most heterogeneous part of the crust. To overcome the limitations of the acquisition geometry, here we are using an innovative multistep approach. We combine a synthetic ocean bottom experiment (SOBE), 3-D traveltime tomography, 2D elastic full waveform and a reverse time migration (RTM) formalism, and present one of the most detailed imagery to date of a massive and complex magmatic system beneath Axial seamount, an active submarine volcano that lies at the intersection of the Juan de Fuca ridge and the Cobb-Eickelberg seamount chain. We present high-resolution images along 12 seismic lines that span the volcano. We refine the extent/volume of the main crustal magma reservoir that lies beneath the central caldera. We investigate the extent, volume and physical state of a secondary magma body present to the southwest and study its connections with the main magma reservoir. Additionally, we present a 3D tomographic model of the entire volcano that reveals a subsiding caldera floor that provides a near perfect trap for the ponding of lava flows, supporting a "trapdoor" mechanism for caldera formation. Finally, we show that crustal aging (increase in layer 2A velocity with age) is controlled by pipe-like pattern of focused hydrothermal mineralization.

Integrating Images, Applications, and Communications Networks. Volume 5.

DTIC Science & Technology

1987-12-01

AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK Massachusetts Institute of Technology AREA A WORK UNIT NUMBERS Cambridge, MA 02139 II. CONTROLLING...Systems Center (TSC) for their support and assistance, to Professor Joseph Sussman, Director, Center for Transportation Studies ( CTS ) at MIT for his...IEEE Press, New York, 1987. [15] W. J. Hawkins. Bits and Bytes. 0 Popular Science, January, 1984. [16] G. N. Hounsfield . Computerized Tranverse Axial

Computed tomographic analysis of deformity and dimensional changes in the eyeball

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

Osborne, D.R.; Foulks, G.N.

1984-12-01

Computed tomography (CT) was performed in 40 patients with a confirmed ophthalmic diagnosis and a change in the dimensions or configuration of the eyeball. Abnormalities studied included coloboma, microphthalmus, buphthalmos, axial myopia, macrophthalmus, phthisis bulbi, trauma, neoplasm, posterior staphyloma, granuloma, pseudotumor, and surgicalscleral banding for retinal detachment. CT findings could be grouped into three categories depending upon whether the eye was small, large, or normal in size, with the findings in each group allowing distinction of most disease processes.

[Imaging of temporo-mandibular disorders].

PubMed

Felizardo, Rufino; Foucart, Jean-Michel; Pizelle, Christophe

2012-03-01

Dominated for years by standard films (tomographic mouth open and mouth closed X-rays, MRI) radiographs of the TMJ have progressively lost their usefulness to diagnosticians who have progressively increased their reliance on well codified clinical examinations, which suffice in a great majority of cases.The indications for and diagnostic worth of radiological studies and the impact they have on the management of TMJ disorders are today quite low especially when the high cost of procedures like MRI, computerized tomography, and CBCT is taken into account. In this article we discuss the various maladies that dentists might encounter and the situations in which radiological examinations are still indicated. © EDP Sciences, SFODF, 2012.

High-resolution velocity measurements using dual-view tomographic digital holographic microscopy

NASA Astrophysics Data System (ADS)

Gao, Jian; Agarwal, Karuna; Katz, Joseph

2017-11-01

A recently developed two-view tomographic digital holographic microscopy (DHM) system is used for measuring the flow around a pair of cubes with height of 90 wall units immersed in the inner layer of a turbulent channel flow at Reτ = 2500. Matching of the two views at 1- μm precision is achieved by implementing a self-calibration procedure that determines the three-dimensional, three-component (3D3C) distortion function, which corrects the geometric mapping. The procedure has been tested using distorted synthetic particle fields, and then implemented on experimental data. The two views are used to overcome the reduced accuracy of DHM in the axial direction of the reference beam due to elongation of the reconstructed traces. Multiplying the two precisely-matched 3D intensity fields is used for truncating the elongated traces. The velocity distributions are obtained by 3D particle tracking guided by 3D cross-correlation of the truncated intensity fields along with other size/shape/smoothness constraints. As demonstrated by how divergence-free the data is, the resulting 3D3C velocity field is substantially more accurate than results obtained from single-view DHM. Results show that the cube is surrounded by a vorticity ``canopy'' that extends from upstream of its front surface to the separated region in its near wake. Nearly axial necklace vortices remain confined to the near wall region between the cubes, but expand rapidly behind them. Funded by NSF and ONR.

Factors prognostic for phonetic development after cleft palate repair.

PubMed

Lee, Joon Seok; Kim, Jae Bong; Lee, Jeong Woo; Yang, Jung Dug; Chung, Ho Yun; Cho, Byung Chae; Choi, Kang Young

2015-10-01

Palatoplasty is aimed to achieve normal speech, improve food intake, and ensure successful maxillary growth. However, the velopharyngeal function is harder to control than other functions. Therefore, many studies on the prognostic factor of velopharyngeal insufficiency have been conducted. This study aimed to evaluate the relationships between speech outcomes and multimodality based on intraoral and preoperative three-dimensional computerized tomographic (CT) findings. Among 73 children with cleft palate who underwent palatoplasty between April 2011 and August 2014 at Kyungpook National University Hospital (KNUH), 27 were retrospectively evaluated. The 27 cases were non-syndromic, for which successful speech evaluation was conducted by a single speech-language pathologist (Table 1). Successful speech evaluation was defined as performing the test three times in 6-month intervals. Three intraoral parameters were measured before and immediately after operation (Fig. 1). On axial- and coronal-view preoperative facial CT, 5 and 2 different parameters were analyzed, respectively (Figs. 2 and 3). Regression analysis (SPSS IBM 22.0) was used in the statistical analysis. Two-flap palatoplasty and Furlow's double opposing Z-plasty were performed in 15 and 12 patients, respectively. The operation was performed 11 months after birth on average. Children with a higher palatal arch and wider maxillary tuberosity distance showed hypernasality (p < 0.05; Table 2). The useful prognostic factors of velopharyngeal function after palatoplasty were palate width and height, rather than initial diagnosis, treatment method, or palate length. Therefore, a more active intervention is needed, such as orthopedic appliance, posterior pharyngeal wall augmentation, or early speech training. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

An evaluation of the effectiveness of adaptive histogram equalization for contrast enhancement.

PubMed

Zimmerman, J B; Pizer, S M; Staab, E V; Perry, J R; McCartney, W; Brenton, B C

1988-01-01

Adaptive histogram equalization (AHE) and intensity windowing have been compared using psychophysical observer studies. Experienced radiologists were shown clinical CT (computerized tomographic) images of the chest. Into some of the images, appropriate artificial lesions were introduced; the physicians were then shown the images processed with both AHE and intensity windowing. They were asked to assess the probability that a given image contained the artificial lesion, and their accuracy was measured. The results of these experiments show that for this particular diagnostic task, there was no significant difference in the ability of the two methods to depict luminance contrast; thus, further evaluation of AHE using controlled clinical trials is indicated.

CMT for materials science

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

Kinney, J.

This session is comprised of two articles by John Kinney describing biomedical and other uses for computerized tomography. In the first article, Kinney describes the use of a three-dimensional x-ray tomographic microscope to image the trabecular bone architecture of the proximal tibias of rats in vivo. Research in this field may help to detect the earliest stages of hypoestrogenemic bone loss and may help to more rapidly test the effectiveness of new clinical treatments for this major public health problem. The second article describes recent advances in X-ray tomography using synchrotron radiation to evaluate microstructures in ceramic matrix composites, bonemore » loss in osteoporosis, and the development of carries lesions in teeth.« less

Right Cardiac Chambers Involvement by a Malignant Testicular Germ Cell Tumor: An Imaging-pathologic Correlation.

PubMed

do Nascimento, Felipe Barjud Pereira; Albieri, Lilian; Bento Dos Santos, Glaucia Aparecida; Dolhnikoff, Marisa

2016-07-01

The cardiac chamber's involvement with neoplastic embolism has been rarely reported; it is mostly associated with gastric, breast, lung, liver, and prostate cancers, and usually affects the pulmonary arteries. This paper reports a case of a 31-year-old man with a malignant testicular germ cell tumor who presented with multiple episodes of pulmonary thromboembolism and died of sudden respiratory failure 1 year after the initial diagnosis. Death was attributed to massive pulmonary embolism and pulmonary infarction associated with a neoplastic thrombus that extended from the gonadal veins to pulmonary arteries. A postmortem computerized tomographic angiography and autopsy confirmed this finding. Copyright © 2016 Elsevier Inc. All rights reserved.

Ureteral stone location at emergency room presentation with colic.

PubMed

Eisner, Brian H; Reese, Adam; Sheth, Sonali; Stoller, Marshall L

2009-07-01

It is thought that the 3 narrowest points of the ureter are the ureteropelvic junction, the point where the ureter crosses anterior to the iliac vessels and the ureterovesical junction. Textbooks describe these 3 sites as the most likely places for ureteral stones to lodge. We defined the stone position in the ureter when patients first present to the emergency department with colic. We retrospectively reviewed the records of 94 consecutive patients who presented to the emergency department with a chief complaint of colic and computerized tomography showing a single unilateral ureteral calculus. Axial, coronal and 3-dimensional reformatted computerized tomography scans were evaluated, and stone position and size (maximal axial and coronal diameters) were recorded, as were the position of the ureteropelvic junction, the iliac vessels (where the ureter crosses anterior to the iliac vessels) and the ureterovesical junction. Patients with a history of nephrolithiasis, shock wave lithotripsy, ureteroscopy or percutaneous nephrolithotripsy were excluded from study. Statistical analysis was performed using Student's t test and Pearson's correlation coefficient. At the time of emergency department presentation for colic ureteral stone position was the ureteropelvic junction in 10.6% cases, between the ureteropelvic junction and the iliac vessels in 23.4%, where the ureter crosses anterior to the iliac vessels in 1.1%, between the iliac vessels and the ureterovesical junction in 4.3% and at the ureterovesical junction in 60.6%. Proximal calculi had a greater axial diameter than distal calculi (mean 6.1 vs 4.0 mm) and a greater coronal diameter than distal calculi (6.8 vs 4.1 mm, each p <0.001). Axial and coronal diameters moderately correlated with stone position (r = -0.47 and -0.55, respectively, each p <0.001). Proximal ureteral stones were larger in axial and coronal diameter than distal ureteral stones. At emergency department presentation for colic most stones were at the ureterovesical junction and in the proximal ureter between the ureteropelvic junction and the iliac vessels. A few stones were at the ureteropelvic junction and only 1 lodged at the level where the ureter crosses anterior to the iliac vessels, despite the literature stating that these locations are 2 of the 3 most likely places for stones to become lodged.

Cerebral infarction in association with Ecstasy abuse.

PubMed Central

Manchanda, S.; Connolly, M. J.

1993-01-01

A previously fit 35 year old man presented with a right hemiparesis and dysphasia 36 hours after abuse of Ecstasy (3,4-methylenedioxymethamphetamine). Computerized axial tomography scan demonstrated an extensive acute left cerebral infarction and carotid digital subtraction angiogram, 2 days after admission, revealed left middle cerebral artery occlusion. There were no other known risk factors and all other investigations were negative. The patient made a partial recovery. We propose an association between Ecstasy abuse and cerebral infarction. PMID:7904748

Cerebral infarction in association with Ecstasy abuse.

PubMed

Manchanda, S; Connolly, M J

1993-11-01

A previously fit 35 year old man presented with a right hemiparesis and dysphasia 36 hours after abuse of Ecstasy (3,4-methylenedioxymethamphetamine). Computerized axial tomography scan demonstrated an extensive acute left cerebral infarction and carotid digital subtraction angiogram, 2 days after admission, revealed left middle cerebral artery occlusion. There were no other known risk factors and all other investigations were negative. The patient made a partial recovery. We propose an association between Ecstasy abuse and cerebral infarction.

Keeping the Edge. Air Force Materiel Command Cold War Context (1945-1991). Volume 2: Installations and Facilities

DTIC Science & Technology

2003-08-01

connector increased the strength of the joints by spreading the load more equally over the cross section of the wood, and in fact made the "all-wood...strength of the timber joints by spreading the load more equally over the cross section of the wood. The Timber Engineering Company established a...Laboratory Computerized Axial Tomography Columbia Broadcasting System Comprehensive Display System Corps of Engineers Ballistic Missile Construction

Vertebral sarcoidosis: demonstration of bone involvement by computerized axial tomography

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

Dinerstein, S.L.; Kovarsky, J.

1984-08-01

A report is given of a rare case of vertebral sarcoidosis with negative conventional spinal x-ray films, yet with typical cystic lesions of the spine found incidentally during abdominal computerized axial tomography (CAT). The patient was a 28-year-old black man, who was admitted for evaluation of a 1 1/2-year history of diffuse myalgias, intermittent fever to 102 F orally, bilateral hilar adenopathy, and leukopenia. A technetium polyphosphate bone scan revealed diffuse areas of increased uptake over the sternum, entire vertebral column, and pelvis. Conventional x-ray films of the cervical, thoracic, and lumbar spine, and an AP view of the pelvismore » were all normal. Chest x-ray film revealed only bilateral hilar adenopathy. During the course of an extensive negative evaluation for infection, an abdominal CAT scan was done, showing multiple, small, sclerotic-rimmed cysts at multiple levels of the lower thoracic and lumbar spine. Bone marrow biopsy revealed only changes consistent with anemia of chronic disease. Mediastinal lymph node biopsy revealed noncaseating granulomas. A tentative diagnosis of sarcoidosis was made, and treatment with prednisone, isoniazid and rifampin was begun. Within two weeks of initiation of prednisone therapy, the patient was symptom-free. A repeat technetium polyphosphate bone scan revealed only a small residual area of mildly increased uptake over the upper thoracic vertebrae.« less

Correlation of quantitative computed tomographic subchondral bone density and ash density in horses.

PubMed

Drum, M G; Les, C M; Park, R D; Norrdin, R W; McIlwraith, C W; Kawcak, C E

2009-02-01

The purpose of this study was to compare subchondral bone density obtained using quantitative computed tomography with ash density values from intact equine joints, and to determine if there are measurable anatomic variations in mean subchondral bone density. Five adult equine metacarpophalangeal joints were scanned with computed tomography (CT), disarticulated, and four 1-cm(3) regions of interest (ROI) cut from the distal third metacarpal bone. Bone cubes were ashed, and percent mineralization and ash density were recorded. Three-dimensional models were created of the distal third metacarpal bone from CT images. Four ROIs were measured on the distal aspect of the third metacarpal bone at axial and abaxial sites of the medial and lateral condyles for correlation with ash samples. Overall correlations of mean quantitative CT (QCT) density with ash density (r=0.82) and percent mineralization (r=0.93) were strong. There were significant differences between abaxial and axial ROIs for mean QCT density, percent bone mineralization and ash density (p<0.05). QCT appears to be a good measure of bone density in equine subchondral bone. Additionally, differences existed between axial and abaxial subchondral bone density in the equine distal third metacarpal bone.

Thoracic computerized tomographic (CT) findings in 2009 influenza A (H1N1) virus infection in Isfahan, Iran

PubMed Central

Rostami, Mojtaba; Javadi, Abbas-Ali; Khorvash, Farzin; Mostafavizadeh, Kamyar; Adibi, Atoosa; Babak, Anahita; Ataei, Behrooz; Meidani, Mohsen; Naeini, Alireza Emami; Salehi, Hasan; Avijgan, Majid; Yazdani, Mohammad Reza; Rezaei, Farshid

2011-01-01

BACKGROUND: Pandemic 2009 H1N1 influenza A virus arrived at Isfahan in August 2009. The virus is still circulating in the world. The abnormal thoracic computerized tomographic (CT) scan findings vary widely among the studies of 2009 H1N1 influenza. We evaluated the thoracic CT findings in patients with 2009 H1N1 virus infection to describe findings compared to previously reported findings, and to suggest patterns that may be suggestive for 2009 influenza A (H1N1) in an appropriate clinical setting. METHODS: Retrospectively, the archive of all patients with a diagnosis of 2009 H1N1 influenza A were reviewed, in Al-Zahra Hospital in Isfahan, central Iran, between September 23rd 2009 to February 20th 2010. Out of 216 patients with confirmed 2009 influenza A (H1N1) virus, 26 cases with abnormal CT were enrolled in the study. Radiologic findings were characterized by the type and pattern of opacities and zonal distribution. RESULTS: Patchy infiltration (34.6%), lobar consolidation (30.8%), and interstitial infiltration (26.9%) with airbronchogram (38.5%) were the predominant findings in our patients. Bilateral distribution was seen in 80.8% of the patients. Only one patient (3.8%) showed ground-glass opacity, predominant radiographic finding in the previous reports and severe acute respiratory syndrome (SARS). CONCLUSIONS: The most common thoracic CT findings in pandemic H1N1 were patchy infiltration, lobar consolidation, and interstitial infiltration with airbronchogram and bilateral distribution. While these findings can be associated with other infections; they may be suggestive to 2009 influenza A (H1N1) in the appropriate clinical setting. Various radiographic patterns can be seen in thoracic CT scans of the influenza patients. Imaging findings are nonspecific. PMID:22091280

Computerized tomographic findings of hepatic fascioliasis compared with melioidosis-caused liver abscesses.

PubMed

Chamadol, Nittaya; Laopaiboon, Vallop; Techasatian, Pennapa; Sukeepaisanjaroen, Wattana; Sripanuskul, Anan

2010-07-01

To compare the computerized tomographic (CT) findings of hepatic fascioliasis (HF) vs. melioidosis-caused liver (ML) abscesses. CT images of 15 patients with hepatic fascioliasis (HF) and 16 patients with melioidosis-caused liver (ML) abscesses were retrospectively reviewed. The authors evaluated and compared HF and ML abscesses (by chi2 and Fisher exact tests) vis-a-vis their location of liver involvement, size, shape, number margins, enhancement patterns, subcapsular lesions, internal architecture, dilatation of intrahepatic bile duct and combination with splenic abscesses. Fourteen HF patients had only liver abscesses and 1 had combined liver and splenic abscesses. Four ML patients had liver abscesses alone while 12 had combined liver and splenic abscesses (p = 0.000). Eight of the 15 HF (53.3%) and 2 of the 16 ML (12.5%) patients had subcapsular lesions (p = 0.019). The liver abscesses were round or oval with linear tracts in 8 of the 15 HF (53.3%) and none of the ML patients (p = 0.001). Between the respective HF and ML patients, there was a significant difference in those with round shaped in ML (p = 0.008), multiple and conglomerately distributed in HF (p = 0.050), multiple and discretely distributed in ML (p = 0.001) no (or minimal) peripheral contrast enhancement in HF (p = 0.011) and moderate or mark peripheral enhancement in ML (p = 0.011). The CT findings of liver abscesses that helped to differentiate hepatic fascioliasis from melioidosis liver abscesses were: their number shape, enhancement pattern, presence of subcapsular lesion (s) and co-occurrence with splenic abscesses. The diagnosis of hepatic fascioliasis by CT is suggested when the following characteristics were seen: (1) multiple, small round or oval (with linear tracts) conglomerates presenting as hypodense lesions; (2) no (or minimal) peripheral contrast enhancement; (3) subcapsular lesions; or (4) less frequent co-occurrence with splenic abscesses.

Comparison of computed tomography and complex motion tomography in the evaluation of cholesteatoma

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

Shaffer, K.A.

1984-08-01

High-resolution axial and coronal computed tomographic (CT) scans were compared with coronal and sagittal complex motion tomograms in patients with suspected middle ear cholesteatomas. Information on CT scans equaled or exceeded that on conventional complex motion tomograms in 16 of 17 patients, and in 11 it provided additional information. Soft-tissue resolution was superior with CT. In 14 patients who underwent surgery, CT provided information that was valuable to the surgeon. On the basis of this study, high-resolution CT is recommended as the preferred method for evaluating most patients with cholesteatomas of the temporal bone.

Atlas of neuroanatomy with radiologic correlation and pathologic illustration

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

Dublin, A.B.; Dublin, W.B.

1982-01-01

This atlas correlates gross neuroanatomic specimens with radiographs and computed tomographic scans. Pathologic specimens and radiographs are displayed in a similar manner. The first chapter, on embryology, shows the development of the telencephalon, diencephalon, mesencephalon, and metencephalon through a series of overlays. The anatomical section shows the surface of the brain, the ventricles and their adjacent structures, and the vascular system. CT anatomy is demonstrated by correlating CT scans with pathologic brain specimens cut in the axial plane. Pathologic changes associated with congenital malformations, injections, injuries, tumors, and other causes are demonstrated in the last six chapters.

Successful Transarterial Embolization of a Posttraumatic Fistula Between a Posterior Communicating Artery Aneurysm and the Cavernous Sinus: A Case Report.

PubMed

Jinbo, Yin; Jun, Liu; Kejie, Mou; Zheng, Zhou

2015-01-01

Posterior communicating artery (PCoA) aneurysm-cavernous sinus fistulae are an extremely rare complication of head injury . The treatment of PCoA aneurysm-cavernous sinus fistulae has not been well described. A 27-year-old man was admitted with a retroocular bruit and blurred vision of the left eye seven months after a severe head injury. We report the angiographic appearance of a posterior communicating artery (PCoA) aneurysm with a fistula to the cavernous sinus. This injury had been previously misinterpreted to be a PCoA aneurysm by computerized tomographic angiography (CTA). The patient was successfully treated with coils and Onyx of a fistula between the PCoA aneurysm and cavernous sinus.

The neurologic evaluation of patients with low-tension glaucoma.

PubMed

Corbett, J J; Phelps, C D; Eslinger, P; Montague, P R

1985-08-01

One hypothesized cause of low-tension glaucoma is chronic or intermittent ischemia of the optic nerve. Since the optic nerve and brain are both parts of the central nervous system and share a common blood supply, the authors wondered if patients with low-tension glaucoma might also have clinical or radiographic evidence of cerebral atrophy. In this study, 27 patients with low-tension glaucoma were examined using neurobehavioral testing, electroencephalography, computerized tomographic scan, neurological history, and physical examination. In only a small number of patients were these tests abnormal. However, 12 of the 27 patients gave a history of common or classic migraine. This unexpected finding raises the possibility that migraine-related ischemia might be the pathogenic mechanism in some cases of low-tension glaucoma.

Optimization in multi-implant placement for immediate loading in edentulous arches using a modified surgical template and prototyping: a case report.

PubMed

Jayme, Sérgio J; Muglia, Valdir A; de Oliveira, Rafael R; Novaes, Arthur B Júnior

2008-01-01

Immediate loading of dental implants shortens the treatment time and makes it possible to give the patient an esthetic appearance throughout the treatment period. Placement of dental implants requires precise planning that accounts for anatomic limitations and restorative goals. Diagnosis can be made with the assistance of computerized tomographic scanning, but transfer of planning to the surgical field is limited. Recently, novel CAD/CAM techniques such as stereolithographic rapid prototyping have been developed to build surgical guides in an attempt to improve precision of implant placement. The aim of this case report was to show a modified surgical template used throughout implant placement as an alternative to a conventional surgical guide.

Measurement of spatial refractive index distributions of fusion spliced optical fibers by digital holographic microtomography

NASA Astrophysics Data System (ADS)

Pan, Feng; Deng, Yating; Ma, Xichao; Xiao, Wen

2017-11-01

Digital holographic microtomography is improved and applied to the measurements of three-dimensional refractive index distributions of fusion spliced optical fibers. Tomographic images are reconstructed from full-angle phase projection images obtained with a setup-rotation approach, in which the laser source, the optical system and the image sensor are arranged on an optical breadboard and synchronously rotated around the fixed object. For retrieving high-quality tomographic images, a numerical method is proposed to compensate the unwanted movements of the object in the lateral, axial and vertical directions during rotation. The compensation is implemented on the two-dimensional phase images instead of the sinogram. The experimental results exhibit distinctly the internal structures of fusion splices between a single-mode fiber and other fibers, including a multi-mode fiber, a panda polarization maintaining fiber, a bow-tie polarization maintaining fiber and a photonic crystal fiber. In particular, the internal structure distortion in the fusion areas can be intuitively observed, such as the expansion of the stress zones of polarization maintaining fibers, the collapse of the air holes of photonic crystal fibers, etc.

Levator claviculae muscle discovered during physical examination for cervical lymphadenopathy.

PubMed

Rosenheimer, J L; Loewy, J; Lozanoff, S

2000-01-01

During a routine physical examination of an adult female with a history of breast cancer and cervical lymphadenopathy, a mass was noted in the right supraclavicular region. The mass was unilateral and easily palpable along the superior border near the median aspect of the clavicle. Plain film radiography, performed to determine whether the mass represented an enlarged jugulo-omohyoid lymph node, revealed an elongated opaque mass in this region. Computed tomographic (CT) and magnetic resonance (MR) images were subsequently obtained. Sequential axial CT scans revealed a cylindrical mass that appeared to be independent of contiguous muscles, including the sternocleidomastoid, anterior, and middle scalene muscles. This mass attached inferiorly to the clavicle and superiorly to the transverse process of the sixth cervical vertebra. Sagittal, coronal, and axial MR scans confirmed the presence of a well-defined superficial mass. It is concluded that the mass represents a levator claviculae (cleidocervical) muscle. This observation underscores the importance of understanding soft tissue variants that may be encountered during a routine physical examination. Copyright 2000 Wiley-Liss, Inc.

[Utility of methoxy isobutyl isonitrile (MIBI) scintigraphy, ultrasound and computerized axial tomography in preoperative topographic diagnosis of hiperparathyroidism].

PubMed

Gómez Palacios, Angel; Gómez Zábala, Jesús; Gutiérrez, María Teresa; Expósito, Amaya; Barrios, Borja; Zorraquino, Angel; Taibo, Miguel Angel; Iturburu, Ignacio

2006-12-01

1. To assess the sensitivity of scintigraphy using methoxy isobutyl isonitrile (MIBI). 2. To compare its resolution with that of ultrasound (US) and computerized axial tomography (CAT). 3. To use its diagnostic reliability to determine whether selective approaches can be used to treat hyperparathyroidism (HPT). A study of 76 patients who underwent surgery for HPT between 1996 and 2005 was performed. MIBI scintigraphy and cervical US were used for whole-body scanning in all patients; CAT was used in 47 patients. Intraoperative and postoperative biopsies were used for final evaluation of the tests, after visualization and surgical extirpation. The results of scintigraphy were positive in 65 patients (85.52%). The diagnosis was correct in all of the single images. Multiple images were due to hyperplasia and parathyroid adenomas with thyroid disease (5.2%). Three images, incorrectly classified as negative (3.94%), were positive. The sensitivity of US was 63% and allowed detection of three MIBI-negative adenomas (4%). CAT was less sensitive (55%), but detected a further three MIBI-negative adenomas (4%). 1. The sensitivity of MIBI reached 89.46%. In the absence of thyroid nodules, MIBI diagnosed 100% of single lesions. Pathological thyroid processes produced false-positive results (5.2%) and there were diagnostic errors (4%). 2. MIBI scintigraphy was more sensitive than US and CAT. 3. Positive, single image scintigraphy allows a selective cervical approach. US and CAT may help to save a further 8% of patients (with negative scintigraphy).

A computerized tomography system for transcranial ultrasound imaging.

PubMed

Tang, Sai Chun; Clement, Gregory T

Hardware for tomographic imaging presents both challenge and opportunity for simplification when compared with traditional pulse-echo imaging systems. Specifically, point diffraction tomography does not require simultaneous powering of elements, in theory allowing just a single transmit channel and a single receive channel to be coupled with a switching or multiplexing network. In our ongoing work on transcranial imaging, we have developed a 512-channel system designed to transmit and/or receive a high voltage signal from/to arbitrary elements of an imaging array. The overall design follows a hierarchy of modules including a software interface, microcontroller, pulse generator, pulse amplifier, high-voltage power converter, switching mother board, switching daughter board, receiver amplifier, analog-to-digital converter, peak detector, memory, and USB communication. Two pulse amplifiers are included, each capable of producing up to 400Vpp via power MOSFETS. Switching is based around mechanical relays that allow passage of 200V, while still achieving switching times of under 2ms, with an operating frequency ranging from below 100kHz to 10MHz. The system is demonstrated through ex vivo human skulls using 1MHz transducers. The overall system design is applicable to planned human studies in transcranial image acquisition, and may have additional tomographic applications for other materials necessitating a high signal output.

Multi-dimensional distribution of near-field ionospheric disturbances produced by the 2015 Mw7.8 Nepal earthquake

NASA Astrophysics Data System (ADS)

Tang, Jun; Yuan, Yunbin

2017-10-01

Ionospheric anomalies possibly associated with large earthquakes, particularly coseismic ionospheric disturbances, have been detected by global positioning system (GPS). A large Nepal earthquake with magnitude Mw7.8 occurred on April 25, 2015. In this paper, we investigate the multi-dimensional distribution of near-field coseismic ionospheric disturbances (CIDs) using total electron content (TEC) and computerized ionospheric tomography (CIT) from regional GPS observational data. The results show significant ionospheric TEC disturbances and interesting multi-dimensional structures around the main shock. Regarding the TEC changes, coseismic ionospheric disturbances occur approximately 10-20 min after the earthquake northeast and northwest of epicentre. The maximum ridge-to-trough amplitude of CIDs is up to approximately 0.90 TECU/min. Propagation velocities of the TEC disturbances are 1.27 ± 0.06 km/s and 1.91 ± 0.38 km/s. It is believed that the ionospheric disturbances are triggered by acoustic and Rayleigh waves. Tomographic results show that the three-dimensional distribution of ionospheric disturbances obviously increases at an altitude of 300 km above the surrounding epicentre, predominantly in the entire region between 200 km and 400 km. Significant ionospheric disturbances appear at 06:30 UT from tomographic images. This study reveals characteristics of an ionospheric anomaly caused by the Nepal earthquake.

Orthodontic decompensation in skeletal Class III malocclusion: redefining the amount of movement assessed by Cone-Beam Computed Tomography

PubMed Central

Cappellozza, José Antonio Zuega; Guedes, Fabio Pinto; Nary, Hugo; Capelozza, Leopoldino; Cardoso, Mauricio de Almeida

2015-01-01

Introduction: Cone-Beam Computed Tomography (CBCT) is essential for tridimensional planning of orthognathic surgery, as it allows visualization and evaluation of bone structures and mineralized tissues. Tomographic slices allow evaluation of tooth inclination and individualization of movement performed during preoperative decompensation. The aim of this paper was to assess maxillary and mandibular incisors inclination pre and post orthodontic decompensation in skeletal Class III malocclusion. Methods: The study was conducted on six individuals with skeletal Class III malocclusion, surgically treated, who had Cone-Beam Computed Tomographic scans obtained before and after orthodontic decompensation. On multiplanar reconstruction view, tomographic slices (axial, coronal and sagittal) were obtained on the long axis of each incisor. The sagittal slice was used for measurement taking, whereas the references used to assess tooth inclination were the long axis of maxillary teeth in relation to the palatal plane and the long axis of mandibular teeth in relation to the mandibular plane. Results: There was significant variation in the inclination of incisors before and after orthodontic decompensation. This change was of greater magnitude in the mandibular arch, evidencing that natural compensation is more effective in this arch, thereby requiring more intensive decompensation. Conclusion: When routinely performed, the protocols of decompensation treatment in surgical individuals often result in intensive movements, which should be reevaluated, since the extent of movement predisposes to reduction in bone attachment levels and root length. PMID:26560818

[Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].

PubMed

Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

2007-03-20

In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.

WE-G-18A-08: Axial Cone Beam DBPF Reconstruction with Three-Dimensional Weighting and Butterfly Filtering

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

Tang, S; Wang, W; Tang, X

2014-06-15

Purpose: With the major benefit in dealing with data truncation for ROI reconstruction, the algorithm of differentiated backprojection followed by Hilbert filtering (DBPF) is originally derived for image reconstruction from parallel- or fan-beam data. To extend its application for axial CB scan, we proposed the integration of the DBPF algorithm with 3-D weighting. In this work, we further propose the incorporation of Butterfly filtering into the 3-D weighted axial CB-DBPF algorithm and conduct an evaluation to verify its performance. Methods: Given an axial scan, tomographic images are reconstructed by the DBPF algorithm with 3-D weighting, in which streak artifacts existmore » along the direction of Hilbert filtering. Recognizing this orientation-specific behavior, a pair of orthogonal Butterfly filtering is applied on the reconstructed images with the horizontal and vertical Hilbert filtering correspondingly. In addition, the Butterfly filtering can also be utilized for streak artifact suppression in the scenarios wherein only partial scan data with an angular range as small as 270° are available. Results: Preliminary data show that, with the correspondingly applied Butterfly filtering, the streak artifacts existing in the images reconstructed by the 3-D weighted DBPF algorithm can be suppressed to an unnoticeable level. Moreover, the Butterfly filtering also works at the scenarios of partial scan, though the 3-D weighting scheme may have to be dropped because of no sufficient projection data are available. Conclusion: As an algorithmic step, the incorporation of Butterfly filtering enables the DBPF algorithm for CB image reconstruction from data acquired along either a full or partial axial scan.« less

Maximum Diameter Measurements of Aortic Aneurysms on Axial CT Images After Endovascular Aneurysm Repair: Sufficient for Follow-up?

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

Baumueller, Stephan, E-mail: Stephan.Baumueller@usz.ch; Nguyen, Thi Dan Linh, E-mail: ThiDanLinh.Nguyen@usz.ch; Goetti, Robert Paul, E-mail: RobertPaul.Goetti@usz.ch

2011-12-15

Purpose: To assess the accuracy of maximum diameter measurements of aortic aneurysms after endovascular aneurysm repair (EVAR) on axial computed tomographic (CT) images in comparison to maximum diameter measurements perpendicular to the intravascular centerline for follow-up by using three-dimensional (3D) volume measurements as the reference standard. Materials and Methods: Forty-nine consecutive patients (73 {+-} 7.5 years, range 51-88 years), who underwent EVAR of an infrarenal aortic aneurysm were retrospectively included. Two blinded readers twice independently measured the maximum aneurysm diameter on axial CT images performed at discharge, and at 1 and 2 years after intervention. The maximum diameter perpendicular tomore » the centerline was automatically measured. Volumes of the aortic aneurysms were calculated by dedicated semiautomated 3D segmentation software (3surgery, 3mensio, the Netherlands). Changes in diameter of 0.5 cm and in volume of 10% were considered clinically significant. Intra- and interobserver agreements were calculated by intraclass correlations (ICC) in a random effects analysis of variance. The two unidimensional measurement methods were correlated to the reference standard. Results: Intra- and interobserver agreements for maximum aneurysm diameter measurements were excellent (ICC = 0.98 and ICC = 0.96, respectively). There was an excellent correlation between maximum aneurysm diameters measured on axial CT images and 3D volume measurements (r = 0.93, P < 0.001) as well as between maximum diameter measurements perpendicular to the centerline and 3D volume measurements (r = 0.93, P < 0.001). Conclusion: Measurements of maximum aneurysm diameters on axial CT images are an accurate, reliable, and robust method for follow-up after EVAR and can be used in daily routine.« less

A High-Precision Instrument for Mapping of Rotational Errors in Rotary Stages

DOE PAGES

Xu, W.; Lauer, K.; Chu, Y.; ...

2014-11-02

A rotational stage is a key component of every X-ray instrument capable of providing tomographic or diffraction measurements. To perform accurate three-dimensional reconstructions, runout errors due to imperfect rotation (e.g. circle of confusion) must be quantified and corrected. A dedicated instrument capable of full characterization and circle of confusion mapping in rotary stages down to the sub-10 nm level has been developed. A high-stability design, with an array of five capacitive sensors, allows simultaneous measurements of wobble, radial and axial displacements. The developed instrument has been used for characterization of two mechanical stages which are part of an X-ray microscope.

Three-dimensional ophthalmic optical coherence tomography with a refraction correction algorithm

NASA Astrophysics Data System (ADS)

Zawadzki, Robert J.; Leisser, Christoph; Leitgeb, Rainer; Pircher, Michael; Fercher, Adolf F.

2003-10-01

We built an optical coherence tomography (OCT) system with a rapid scanning optical delay (RSOD) line, which allows probing full axial eye length. The system produces Three-dimensional (3D) data sets that are used to generate 3D tomograms of the model eye. The raw tomographic data were processed by an algorithm, which is based on Snell"s law to correct the interface positions. The Zernike polynomials representation of the interfaces allows quantitative wave aberration measurements. 3D images of our results are presented to illustrate the capabilities of the system and the algorithm performance. The system allows us to measure intra-ocular distances.

Use of radiologic modalities in coccidioidal meningitis

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

Stadalnik, R.C.; Goldstein, E.; Hoeprich, P.D.

1981-01-01

The diagnostic utility of pentetate indium trisodium CSF studies, technetium Tc 99m brain scans, and computerized tomographic (CT) scans was evaluated in eight patients in whom coccidioidal meningitis developed following a dust storm in the Central Valley of California. The 111In flow studies and the CT scans demonstrated hydrocephalus in five patients with clinical findings suggesting this complication. Ventriculitis has not previously been diagnosed before death in patients with coccidioidal meningitis; however, it was demonstrated in two patients by the technetium Tc 99m brain scan. The finding that communicating hydrocephalus occurs early in meningitis and interferes with CSF flow intomore » infected basilar regions has important therapeutic implications in that antifungal agents injected into the lumbar subarachnoid space may not reach these regions.« less

Quantitative PET and SPECT performance characteristics of the Albira Trimodal pre-clinical tomograph

NASA Astrophysics Data System (ADS)

Spinks, T. J.; Karia, D.; Leach, M. O.; Flux, G.

2014-02-01

The Albira Trimodal pre-clinical scanner comprises PET, SPECT and CT sub-systems and thus provides a range of pre-clinical imaging options. The PET component consists of three rings of single-crystal LYSO detectors with axial/transverse fields-of-view (FOVs) of 148/80 mm. The SPECT component has two opposing CsI detectors (100 × 100 mm2) with single-pinhole (SPH) or multi(9)-pinhole (MPH) collimators; the detectors rotate in 6° increments and their spacing can be adjusted to provide different FOVs (25 to 120 mm). The CT sub-system provides ‘low’ (200 µA, 35 kVp) or ‘high’ (400 µA, 45 kVp) power x-rays onto a flat-panel CsI detector. This study examines the performance characteristics and quantitative accuracy of the PET and SPECT components. Using the NEMA NU 4-2008 specifications (22Na point source), the PET spatial resolution is 1.5 + 0.1 mm on axis and sensitivity 6.3% (axial centre) and 4.6% (central 70 mm). The usable activity range is ≤ 10 MBq (18F) over which good linearity (within 5%) is obtained for a uniform cylinder spanning the axial FOV; increasing deviation from linearity with activity is, however, observed for the NEMA (mouse) line source phantom. Image uniformity axially is within 5%. Spatial resolution (SPH/MPH) for the minimum SPECT FOV used for mouse imaging (50 mm) is 1.5/1.7 mm and point source sensitivity 69/750 cps MBq-1. Axial uniformity of SPECT images (%CV of regions-of-interest counts along the axis) is mostly within 8% although there is a range of 30-40% for the largest FOV. The variation is significantly smaller within the central 40 mm. Instances of count rate nonlinearity (PET) and axial non-uniformity (SPECT) were found to be reproducible and thus amenable to empirical correction.

Experience with single photon emission computerized tomography (SPECT) in follow-up of sternotomy healing.

PubMed

Harjula, A; Järvinen, A; Mattila, S; Porkka, L

1985-01-01

Single photon emission computerized tomography (SPECT) was performed thrice in ten patients undergoing open-heart surgery--preoperatively and 2 and 12 weeks postoperatively. The operations were done for ischemic heart disease (5), aortic valvular stenosis (2), aortic valvular insufficiency (1), leaking mitral prosthetic valve (1) and combined aortic and mitral valvular stenosis and insufficiency (1). The healing process in the longitudinally divided sternum was evaluated from the SPECT study. Four conventional static images in two dimensions were registered in anteroposterior, posteroanterior and left and right lateral projections. A tomographic study was done. Quantitative analyses were performed. The ratio of the sternal counts to the counts from a thoracic vertebra was calculated for use as a reference. The activity ratios showed a similar pattern in six cases, with initial increases and at 12 weeks slight decrease compared with the preoperative values. In two cases the activity was still increasing after 12 postoperative weeks. One patient, with sternotomy also one year previously, showed only slightly increased activity. The activity at the areas of the sternal wires was increased in six cases. The study thus revealed differing patterns of isotope uptake, although recovery was uneventful in all patients. The differences may reflect the possibility that the operative course and the preoperative clinical status can influence the healing mechanisms.

Improving perceptions of empathy in patients undergoing low-yield computerized tomographic imaging in the emergency department.

PubMed

Lin, Michelle P; Probst, Marc A; Puskarich, Michael A; Dehon, Erin; Kuehl, Damon R; Wang, Ralph C; Hess, Erik P; Butler, Katie; Runyon, Michael S; Wang, Hao; Courtney, D Mark; Muckley, Brandon; Hobgood, Cherri D; Hall, Cassandra L; Kline, Jeffrey A

2018-04-01

We assessed emergency department (ED) patient perceptions of how physicians can improve their language to determine patient preferences for 11 phrases to enhance physician empathy toward the goal of reducing low-value advanced imaging. Multi-center survey study of low-risk ED patients undergoing computerized tomography (CT) scanning. We enroled 305 participants across nine sites. The statement "I have carefully considered what you told me about what brought you here today" was most frequently rated as important (88%). The statement "I have thought about the cost of your medical care to you today" was least frequently rated as important (59%). Participants preferred statements indicating physicians had considered their "vital signs and physical examination" (86%), "past medical history" (84%), and "what prior research tells me about your condition" (79%). Participants also valued statements conveying risks of testing, including potential kidney injury (78%) and radiation (77%). The majority of phrases were identified as important. Participants preferred statements conveying cognitive reassurance, medical knowledge and risks of testing. Our findings suggest specific phrases have the potential to enhance ED patient perceptions of physician empathy. Further research is needed to determine whether statements to convey empathy affect diagnostic testing rates. Copyright © 2017 Elsevier B.V. All rights reserved.

Design of an ultraprecision computerized numerical control chemical mechanical polishing machine and its implementation

NASA Astrophysics Data System (ADS)

Zhang, Chupeng; Zhao, Huiying; Zhu, Xueliang; Zhao, Shijie; Jiang, Chunye

2018-01-01

The chemical mechanical polishing (CMP) is a key process during the machining route of plane optics. To improve the polishing efficiency and accuracy, a CMP model and machine tool were developed. Based on the Preston equation and the axial run-out error measurement results of the m circles on the tin plate, a CMP model that could simulate the material removal at any point on the workpiece was presented. An analysis of the model indicated that lower axial run-out error led to lower material removal but better polishing efficiency and accuracy. Based on this conclusion, the CMP machine was designed, and the ultraprecision gas hydrostatic guideway and rotary table as well as the Siemens 840Dsl numerical control system were incorporated in the CMP machine. To verify the design principles of machine, a series of detection and machining experiments were conducted. The LK-G5000 laser sensor was employed for detecting the straightness error of the gas hydrostatic guideway and the axial run-out error of the gas hydrostatic rotary table. A 300-mm-diameter optic was chosen for the surface profile machining experiments performed to determine the CMP efficiency and accuracy.

Identification of High-Risk Plaques Destined to Cause Acute Coronary Syndrome Using Coronary Computed Tomographic Angiography and Computational Fluid Dynamics.

PubMed

Lee, Joo Myung; Choi, Gilwoo; Koo, Bon-Kwon; Hwang, Doyeon; Park, Jonghanne; Zhang, Jinlong; Kim, Kyung-Jin; Tong, Yaliang; Kim, Hyun Jin; Grady, Leo; Doh, Joon-Hyung; Nam, Chang-Wook; Shin, Eun-Seok; Cho, Young-Seok; Choi, Su-Yeon; Chun, Eun Ju; Choi, Jin-Ho; Nørgaard, Bjarne L; Christiansen, Evald H; Niemen, Koen; Otake, Hiromasa; Penicka, Martin; de Bruyne, Bernard; Kubo, Takashi; Akasaka, Takashi; Narula, Jagat; Douglas, Pamela S; Taylor, Charles A; Kim, Hyo-Soo

2018-03-14

We investigated the utility of noninvasive hemodynamic assessment in the identification of high-risk plaques that caused subsequent acute coronary syndrome (ACS). ACS is a critical event that impacts the prognosis of patients with coronary artery disease. However, the role of hemodynamic factors in the development of ACS is not well-known. Seventy-two patients with clearly documented ACS and available coronary computed tomographic angiography (CTA) acquired between 1 month and 2 years before the development of ACS were included. In 66 culprit and 150 nonculprit lesions as a case-control design, the presence of adverse plaque characteristics (APC) was assessed and hemodynamic parameters (fractional flow reserve derived by coronary computed tomographic angiography [FFR CT ], change in FFR CT across the lesion [△FFR CT ], wall shear stress [WSS], and axial plaque stress) were analyzed using computational fluid dynamics. The best cut-off values for FFR CT , △FFR CT , WSS, and axial plaque stress were used to define the presence of adverse hemodynamic characteristics (AHC). The incremental discriminant and reclassification abilities for ACS prediction were compared among 3 models (model 1: percent diameter stenosis [%DS] and lesion length, model 2: model 1 + APC, and model 3: model 2 + AHC). The culprit lesions showed higher %DS (55.5 ± 15.4% vs. 43.1 ± 15.0%; p < 0.001) and higher prevalence of APC (80.3% vs. 42.0%; p < 0.001) than nonculprit lesions. Regarding hemodynamic parameters, culprit lesions showed lower FFR CT and higher △FFR CT , WSS, and axial plaque stress than nonculprit lesions (all p values <0.01). Among the 3 models, model 3, which included hemodynamic parameters, showed the highest c-index, and better discrimination (concordance statistic [c-index] 0.789 vs. 0.747; p = 0.014) and reclassification abilities (category-free net reclassification index 0.287; p = 0.047; relative integrated discrimination improvement 0.368; p < 0.001) than model 2. Lesions with both APC and AHC showed significantly higher risk of the culprit for subsequent ACS than those with no APC/AHC (hazard ratio: 11.75; 95% confidence interval: 2.85 to 48.51; p = 0.001) and with either APC or AHC (hazard ratio: 3.22; 95% confidence interval: 1.86 to 5.55; p < 0.001). Noninvasive hemodynamic assessment enhanced the identification of high-risk plaques that subsequently caused ACS. The integration of noninvasive hemodynamic assessments may improve the identification of culprit lesions for future ACS. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary CT Angiography and Computational Fluid Dynamic [EMERALD]; NCT02374775). Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrastenhanced cardiac computerized tomographic angiography in children

PubMed Central

Chakravarthy, Murali; Sunilkumar, Gubbihalli; Pargaonkar, Sumant; Hosur, Rajathadri; Harivelam, Chidananda; Kavaraganahalli, Deepak; Srinivasan, Pradeep

2015-01-01

Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases. Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in patients, which was followed by electrocardiogram gated cardiac CT angiography. General anesthesia was induced using sleep dose of intravenous propofol. After the initial check CT, on request by the radiologist, apnea was induced by the anesthesiologist by administering 1 mg/kg of intravenous suxamethonium. Soon after apnea ensued, the contrast was injected, and CT angiogram carried out. CT images in the “apnea group” were compared with those in “nonapnea group.” After the completion of the procedure, the patients were mask ventilated with 100% oxygen till the spontaneous ventilation was restored. Results: We studied 46 patients, of whom 36 with apnea and yet another 10 without. The quality of the image, visualization of structures such as cardiac wall, outflow tracts, lung field, aortopulmonary shunts, and coronary arteries were analyzed and subjected to statistical analysis (Mann–Whitney U, Fischer's exact test and Pearson's Chi-square test). In the induced apnea group, overall image quality was considered excellent in 89% (n = 33) of the studies, while in the “no apnea group,” only 30% of studies were excellent. Absent or minimal motion artifacts were seen in a majority of the studies in apnea group (94%). In the nonapnea group, the respiratory and body motion artifacts were severe in 50%, moderate in 30%, and minimal in 20%, but they were significantly lesser in the apnea group. All the studied parameters were statistically significant in the apnea group in contrast to nonapnea group (P < 0.000). Conclusion: The image quality of cardiac CT angiography greatly improves, and motion artifact significantly decreases with the use of induced apnea in pediatrics patients being evaluated for congenital heart disease. This technique poses no additional morbidity of significance. PMID:25849686

Computational modeling of optical projection tomographic microscopy using the finite difference time domain method.

PubMed

Coe, Ryan L; Seibel, Eric J

2012-12-01

We present a method for modeling image formation in optical projection tomographic microscopy (OPTM) using high numerical aperture (NA) condensers and objectives. Similar to techniques used in computed tomography, OPTM produces three-dimensional, reconstructed images of single cells from two-dimensional projections. The model is capable of simulating axial scanning of a microscope objective to produce projections, which are reconstructed using filtered backprojection. Simulation of optical scattering in transmission optical microscopy is designed to analyze all aspects of OPTM image formation, such as degree of specimen staining, refractive-index matching, and objective scanning. In this preliminary work, a set of simulations is performed to examine the effect of changing the condenser NA, objective scan range, and complex refractive index on the final reconstruction of a microshell with an outer radius of 1.5 μm and an inner radius of 0.9 μm. The model lays the groundwork for optimizing OPTM imaging parameters and triaging efforts to further improve the overall system design. As the model is expanded in the future, it will be used to simulate a more realistic cell, which could lead to even greater impact.

Optical and tomographic imaging of a middle ear malformation in the bullfrog (Rana catesbeiana).

PubMed

Horowitz, Seth S; Simmons, Andrea Megela; Ketten, Darlene R

2005-08-01

Using a combination of in vivo computerized tomography and histological staining, a middle ear anomaly in two wild-caught American bullfrogs (Rana catesbeiana) is characterized. In these animals, the tympanic membrane, extrastapes, and pars media (shaft) of the stapes are absent on one side of the head, with the other side exhibiting normal morphology. The pars interna (footplate) of the stapes and the operculum are present in their normal positions at the entrance of the otic capsule on both the affected and unaffected sides. The pattern of deformity suggests a partial failure of development of tympanic pathway tissues, but with a preservation of the opercularis pathway. While a definitive proximate cause of the condition could not be determined, the anomalies show similarities to developmental defects in mammalian middle ear formation.

Optical and tomographic imaging of a middle ear malformation in the bullfrog (Rana catesbeiana)

PubMed Central

Horowitz, Seth S.; Simmons, Andrea Megela; Ketten, Darlene R.

2005-01-01

Using a combination of in vivo computerized tomography and histological staining, a middle ear anomaly in two wild-caught American bullfrogs (Rana catesbeiana) is characterized. In these animals, the tympanic membrane, extrastapes, and pars media (shaft) of the stapes are absent on one side of the head, with the other side exhibiting normal morphology. The pars interna(footplate) of the stapes and the operculum are present in their normal positions at the entrance of the otic capsule on both the affected and unaffected sides. The pattern of deformity suggests a partial failure of development of tympanic pathway tissues, but with a preservation of theopercularis pathway. While a definitive proximate cause of the condition could not be determined, the anomalies show similarities to developmental defects in mammalian middle ear formation. PMID:16158670

Tomographic reconstruction of ionospheric electron density during the storm of 5-6 August 2011 using multi-source data

PubMed Central

Tang, Jun; Yao, Yibin; Zhang, Liang; Kong, Jian

2015-01-01

The insufficiency of data is the essential reason for ill-posed problem existed in computerized ionospheric tomography (CIT) technique. Therefore, the method of integrating multi-source data is proposed. Currently, the multiple satellite navigation systems and various ionospheric observing instruments provide abundant data which can be employed to reconstruct ionospheric electron density (IED). In order to improve the vertical resolution of IED, we do research on IED reconstruction by integration of ground-based GPS data, occultation data from the LEO satellite, satellite altimetry data from Jason-1 and Jason-2 and ionosonde data. We used the CIT results to compare with incoherent scatter radar (ISR) observations, and found that the multi-source data fusion was effective and reliable to reconstruct electron density, showing its superiority than CIT with GPS data alone. PMID:26266764

A rare case of ethambutol induced pulmonary eosinophilia

PubMed Central

Saha, Kaushik; Bandyopadhyay, Ankan; Sengupta, Amitabha; Jash, Debraj

2013-01-01

Antitubercular drug (ATD) induced eosinophilic lung disease is a rare phenomenon. It usually occurs due to isoniazid and para amino salicylic acid. A 34-year-male of sputum positive pulmonary tuberculosis, on antitubercular drugs (rifampicin, isoniazid, ethambutol, and pyrazinamide) for last 3 weeks, presented with generalized arthralgia and maculopapular rash for last 2 weeks and shortness of breath for last 1 week. Chest X-ray and High resolution computerized tomographic scan thorax showed bilateral peripheral airspace opacification. Bronchoalveolar lavage revealed 51% eosinophils of total cellularity (1200/cmm) confirming the diagnosis of pulmonary eosinophilia. ATD was stopped for 2 weeks and then reintroduced one by one. Patient again developed similar kind of symptoms with reintroduction of ethambutol. According to criteria for drug induced pulmonary eosinophilia, he was diagnosed as a case of ethambutol induced pulmonary eosinophilia. PMID:24250213

Tomographic reconstruction of ionospheric electron density during the storm of 5-6 August 2011 using multi-source data.

PubMed

Tang, Jun; Yao, Yibin; Zhang, Liang; Kong, Jian

2015-08-12

The insufficiency of data is the essential reason for ill-posed problem existed in computerized ionospheric tomography (CIT) technique. Therefore, the method of integrating multi-source data is proposed. Currently, the multiple satellite navigation systems and various ionospheric observing instruments provide abundant data which can be employed to reconstruct ionospheric electron density (IED). In order to improve the vertical resolution of IED, we do research on IED reconstruction by integration of ground-based GPS data, occultation data from the LEO satellite, satellite altimetry data from Jason-1 and Jason-2 and ionosonde data. We used the CIT results to compare with incoherent scatter radar (ISR) observations, and found that the multi-source data fusion was effective and reliable to reconstruct electron density, showing its superiority than CIT with GPS data alone.

Mid-infrared laser absorption tomography for quantitative 2D thermochemistry measurements in premixed jet flames

NASA Astrophysics Data System (ADS)

Wei, Chuyu; Pineda, Daniel I.; Paxton, Laurel; Egolfopoulos, Fokion N.; Spearrin, R. Mitchell

2018-06-01

A tomographic laser absorption spectroscopy technique, utilizing mid-infrared light sources, is presented as a quantitative method to spatially resolve species and temperature profiles in small-diameter reacting flows relevant to combustion systems. Here, tunable quantum and interband cascade lasers are used to spectrally resolve select rovibrational transitions near 4.98 and 4.19 μm to measure CO and {CO2}, respectively, as well as their vibrational temperatures, in piloted premixed jet flames. Signal processing methods are detailed for the reconstruction of axial and radial profiles of thermochemical structure in a canonical ethylene-air jet flame. The method is further demonstrated to quantitatively distinguish between different turbulent flow conditions.

A method for volume determination of the orbit and its contents by high resolution axial tomography and quantitative digital image analysis.

PubMed Central

Cooper, W C

1985-01-01

The various congenital and acquired conditions which alter orbital volume are reviewed. Previous investigative work to determine orbital capacity is summarized. Since these studies were confined to postmortem evaluations, the need for a technique to measure orbital volume in the living state is presented. A method for volume determination of the orbit and its contents by high-resolution axial tomography and quantitative digital image analysis is reported. This procedure has proven to be accurate (the discrepancy between direct and computed measurements ranged from 0.2% to 4%) and reproducible (greater than 98%). The application of this method to representative clinical problems is presented and discussed. The establishment of a diagnostic system versatile enough to expand the usefulness of computerized axial tomography and polytomography should add a new dimension to ophthalmic investigation and treatment. Images FIGURE 8 FIGURE 9 FIGURE 10 A FIGURE 10 B FIGURE 11 A FIGURE 11 B FIGURE 12 FIGURE 13 FIGURE 14 FIGURE 15 FIGURE 16 FIGURE 17 FIGURE 18 FIGURE 19 FIGURE 20 FIGURE 21 FIGURE 22 FIGURE 23 FIGURE 24 FIGURE 25 FIGURE 26 A FIGURE 26 B FIGURE 27 FIGURE 28 FIGURE 29 FIGURE 30 FIGURE 31 FIGURE 32 PMID:3938582

Monte Carlo simulations of adult and pediatric computed tomography exams: Validation studies of organ doses with physical phantoms

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

Long, Daniel J.; Lee, Choonsik; Tien, Christopher

2013-01-15

Purpose: To validate the accuracy of a Monte Carlo source model of the Siemens SOMATOM Sensation 16 CT scanner using organ doses measured in physical anthropomorphic phantoms. Methods: The x-ray output of the Siemens SOMATOM Sensation 16 multidetector CT scanner was simulated within the Monte Carlo radiation transport code, MCNPX version 2.6. The resulting source model was able to perform various simulated axial and helical computed tomographic (CT) scans of varying scan parameters, including beam energy, filtration, pitch, and beam collimation. Two custom-built anthropomorphic phantoms were used to take dose measurements on the CT scanner: an adult male and amore » 9-month-old. The adult male is a physical replica of University of Florida reference adult male hybrid computational phantom, while the 9-month-old is a replica of University of Florida Series B 9-month-old voxel computational phantom. Each phantom underwent a series of axial and helical CT scans, during which organ doses were measured using fiber-optic coupled plastic scintillator dosimeters developed at University of Florida. The physical setup was reproduced and simulated in MCNPX using the CT source model and the computational phantoms upon which the anthropomorphic phantoms were constructed. Average organ doses were then calculated based upon these MCNPX results. Results: For all CT scans, good agreement was seen between measured and simulated organ doses. For the adult male, the percent differences were within 16% for axial scans, and within 18% for helical scans. For the 9-month-old, the percent differences were all within 15% for both the axial and helical scans. These results are comparable to previously published validation studies using GE scanners and commercially available anthropomorphic phantoms. Conclusions: Overall results of this study show that the Monte Carlo source model can be used to accurately and reliably calculate organ doses for patients undergoing a variety of axial or helical CT examinations on the Siemens SOMATOM Sensation 16 scanner.« less

Model-based registration for assessment of spinal deformities in idiopathic scoliosis

NASA Astrophysics Data System (ADS)

Forsberg, Daniel; Lundström, Claes; Andersson, Mats; Knutsson, Hans

2014-01-01

Detailed analysis of spinal deformity is important within orthopaedic healthcare, in particular for assessment of idiopathic scoliosis. This paper addresses this challenge by proposing an image analysis method, capable of providing a full three-dimensional spine characterization. The proposed method is based on the registration of a highly detailed spine model to image data from computed tomography. The registration process provides an accurate segmentation of each individual vertebra and the ability to derive various measures describing the spinal deformity. The derived measures are estimated from landmarks attached to the spine model and transferred to the patient data according to the registration result. Evaluation of the method provides an average point-to-surface error of 0.9 mm ± 0.9 (comparing segmentations), and an average target registration error of 2.3 mm ± 1.7 (comparing landmarks). Comparing automatic and manual measurements of axial vertebral rotation provides a mean absolute difference of 2.5° ± 1.8, which is on a par with other computerized methods for assessing axial vertebral rotation. A significant advantage of our method, compared to other computerized methods for rotational measurements, is that it does not rely on vertebral symmetry for computing the rotational measures. The proposed method is fully automatic and computationally efficient, only requiring three to four minutes to process an entire image volume covering vertebrae L5 to T1. Given the use of landmarks, the method can be readily adapted to estimate other measures describing a spinal deformity by changing the set of employed landmarks. In addition, the method has the potential to be utilized for accurate segmentations of the vertebrae in routine computed tomography examinations, given the relatively low point-to-surface error.

Mantle-driven geodynamo features - accounting for non-thermal lower mantle features

NASA Astrophysics Data System (ADS)

Choblet, G.; Amit, H.

2011-12-01

Lower mantle heterogeneity responsible for spatial variations of the CMB heat flux could control long term geodynamo properties such as deviations from axial symmetry in the magnetic field and the core flow, frequency of geomagnetic reversals and anisotropic growth of the inner core. In this context, a classical interpretation of tomographic mapping of the lowermost mantle is to correlate linearly seismic velocities to heat flux anomalies. This implicitly assumes that temperature alone controls the tomographic anomalies. In addition, the limited spatial resolution of tomographic images precludes modeling sharp CMB heat flux structures.. There has been growing evidence however that non-thermal origins are also be expected for seismic velocity anomalies: the three main additional control parameters are (i) compositional anomalies possibly associated to the existence of a deep denser layer, (ii) the phase transition in magnesium perovskite believed to occur in the lowermost mantle and (iii) the possible presence of partial melts. Numerical models of mantle dynamics have illustrated how the first two parameters could distort the linear relationship between shear wave velocity anomalies and CMB heat flux (Nakagawa and Tackley, 2008). In this presentation we will consider the effect of such alternative interpretations of seismic velocity anomalies in order to prescribe CMB heat flux as an outer boundary for dynamo simulations. We first focus on the influence of post-perovskite. Taking into account this complexity could result in an improved agreement between the long term average properties of simulated dynamos and geophysical observations, including the Atlantic/Pacific hemispherical dichotomy in core flow activity, the single intense paleomagnetic field structure in the southern hemisphere, and possibly degree 1 dominant mode of inner-core seismic heterogeneity. We then account for sharp anomalies that are not resolved by the global tomographic probe. For instance, Ultra Low Velocity Zones (ULVZs) have been identified by dedicated seismic tools that cannot be observed by global tomographic models. These are likely associated to the hottest regions in the lowermost mantle. We thus model anomalies of the CMB heat flux where narrow ridges with low heat flux are juxtaposed to a large scale degree 2 pattern which represents the dominant component of tomographic observations. We find that hot ridges located with a large-scale positive heat flux anomaly to the east produce a time-average narrow elongated upwelling which acts as a flow barrier at the top of the core and results in intensified low-latitudes magnetic flux patches. This is found to have a clear signature on the meridional component of the thermal wind balance. Based on the lower mantle seismic tomography pattern, time average intense geomagnetic flux patches are expected below east Asia and Oceania and below the Americas.

Vertical structure of medium-scale traveling ionospheric disturbances

NASA Astrophysics Data System (ADS)

Ssessanga, Nicholas; Kim, Yong Ha; Kim, Eunsol

2015-11-01

We develop an algorithm of computerized ionospheric tomography (CIT) to infer information on the vertical and horizontal structuring of electron density during nighttime medium-scale traveling ionospheric disturbances (MSTIDs). To facilitate digital CIT we have adopted total electron contents (TEC) from a dense Global Positioning System (GPS) receiver network, GEONET, which contains more than 1000 receivers. A multiplicative algebraic reconstruction technique was utilized with a calibrated IRI-2012 model as an initial solution. The reconstructed F2 peak layer varied in altitude with average peak-to-peak amplitude of ~52 km. In addition, the F2 peak layer anticorrelated with TEC variations. This feature supports a theory in which nighttime MSTID is composed of oscillating electric fields due to conductivity variations. Moreover, reconstructed TEC variations over two stations were reasonably close to variations directly derived from the measured TEC data set. Our tomographic analysis may thus help understand three-dimensional structure of MSTIDs in a quantitative way.

Measurement of absolute lung volumes by imaging techniques.

PubMed

Clausen, J

1997-10-01

In this paper, the techniques available for estimating total lung capacities from standard chest radiographs in children and infants as well as adults are reviewed. These techniques include manual measurements using ellipsoid and planimetry techniques as well as computerized systems. Techniques are also available for making radiographic lung volume measurements from portable chest radiographs. There are inadequate data in the literature to support recommending one specific technique over another. Though measurements of lung volumes by radiographic, plethysmographic, gas dilution or washout techniques result in remarkably similar mean results when groups of normal subjects are tested, in patients with disease, the results of these different basic measurement techniques can differ significantly. Computed tomographic and magnetic resonance techniques can also be used to measure absolute lung volumes and offer the theoretical advantages that the results in individual subjects are less affected by variances of thoracic shape than are measurements made using conventional chest radiographs.

Technical report on semiautomatic segmentation using the Adobe Photoshop.

PubMed

Park, Jin Seo; Chung, Min Suk; Hwang, Sung Bae; Lee, Yong Sook; Har, Dong-Hwan

2005-12-01

The purpose of this research is to enable users to semiautomatically segment the anatomical structures in magnetic resonance images (MRIs), computerized tomographs (CTs), and other medical images on a personal computer. The segmented images are used for making 3D images, which are helpful to medical education and research. To achieve this purpose, the following trials were performed. The entire body of a volunteer was scanned to make 557 MRIs. On Adobe Photoshop, contours of 19 anatomical structures in the MRIs were semiautomatically drawn using MAGNETIC LASSO TOOL and manually corrected using either LASSO TOOL or DIRECT SELECTION TOOL to make 557 segmented images. In a similar manner, 13 anatomical structures in 8,590 anatomical images were segmented. Proper segmentation was verified by making 3D images from the segmented images. Semiautomatic segmentation using Adobe Photoshop is expected to be widely used for segmentation of anatomical structures in various medical images.

Characterization of microwave plasma in a multicusp using 2D emission based tomography: Bessel modes and wave absorption

NASA Astrophysics Data System (ADS)

Rathore, Kavita; Bhattacharjee, Sudeep; Munshi, Prabhat

2017-06-01

A tomographic method based on the Fourier transform is used for characterizing a microwave plasma in a multicusp (MC), in order to obtain 2D distribution of plasma emissions, plasma (electron) density (Ne) and temperature (Te). The microwave plasma in the MC is characterized as a function of microwave power, gas pressure, and axial distance. The experimentally obtained 2D emission profiles show that the plasma emissions are generated in a circular ring shape. There are usually two bright rings, one at the plasma core and another near the boundary. The experimental results are validated using a numerical code that solves Maxwell's equations inside a waveguide filled with a plasma in a magnetic field, with collisions included. It is inferred that the dark and bright circular ring patterns are a result of superposition of Bessel modes (TE11 and TE21) of the wave electric field inside the plasma filled MC, which are in reasonable agreement with the plasma emission profiles. The tomographically obtained Ne and Te profiles indicate higher densities in the plasma core (˜1010 cm-3) and enhanced electron temperature in the ECR region (˜13 eV), which are in agreement with earlier results using a Langmuir probe and optical emission spectroscopy (OES) diagnostics.

A semi-automatic method for positioning a femoral bone reconstruction for strict view generation.

PubMed

Milano, Federico; Ritacco, Lucas; Gomez, Adrian; Gonzalez Bernaldo de Quiros, Fernan; Risk, Marcelo

2010-01-01

In this paper we present a semi-automatic method for femoral bone positioning after 3D image reconstruction from Computed Tomography images. This serves as grounding for the definition of strict axial, longitudinal and anterior-posterior views, overcoming the problem of patient positioning biases in 2D femoral bone measuring methods. After the bone reconstruction is aligned to a standard reference frame, new tomographic slices can be generated, on which unbiased measures may be taken. This could allow not only accurate inter-patient comparisons but also intra-patient comparisons, i.e., comparisons of images of the same patient taken at different times. This method could enable medical doctors to diagnose and follow up several bone deformities more easily.

Display modes for CT colonography. Part II. Blinded comparison of axial CT and virtual endoscopic and panoramic endoscopic volume-rendered studies.

PubMed

Beaulieu, C F; Jeffrey, R B; Karadi, C; Paik, D S; Napel, S

1999-07-01

To determine the sensitivity of radiologist observers for detecting colonic polyps by using three different data review (display) modes for computed tomographic (CT) colonography, or "virtual colonoscopy." CT colonographic data in a patient with a normal colon were used as base data for insertion of digitally synthesized polyps. Forty such polyps (3.5, 5, 7, and 10 mm in diameter) were randomly inserted in four copies of the base data. Axial CT studies, volume-rendered virtual endoscopic movies, and studies from a three-dimensional mode termed "panoramic endoscopy" were reviewed blindly and independently by two radiologists. Detection improved with increasing polyp size. Trends in sensitivity were dependent on whether all inserted lesions or only visible lesions were considered, because modes differed in how completely the colonic surface was depicted. For both reviewers and all polyps 7 mm or larger, panoramic endoscopy resulted in significantly greater sensitivity (90%) than did virtual endoscopy (68%, P = .014). For visible lesions only, the sensitivities were 85%, 81%, and 60% for one reader and 65%, 62%, and 28% for the other for virtual endoscopy, panoramic endoscopy, and axial CT, respectively. Three-dimensional displays were more sensitive than two-dimensional displays (P < .05). The sensitivity of panoramic endoscopy is higher than that of virtual endoscopy, because the former displays more of the colonic surface. Higher sensitivities for three-dimensional displays may justify the additional computation and review time.

Three-dimensional tomographic mapping related to primary stability and structural miniscrew characteristics.

PubMed

Silvestrini Biavati, A; Tecco, S; Migliorati, M; Festa, F; Panza, G; Marzo, G; Gherlone, E; Tetè, S

2011-05-01

To evaluate the maxilla, mandible, and cortical plates on computerized tomographic (CT) scans to achieve accurate three-dimensional bone thickness measurements. We selected the CT scans of 25 subjects (among 102), aged 18-58 years (10 men, 15 women), with nearly complete dentition. We performed interradicular and bucco-lingual (including cortical plate thickness) measurements in dental areas distal to the canines in both alveolar arches, at three levels (5, 8, and 11 mm) from the alveolar ridge. The mean thicknesses of the cortical plates in the maxilla were 1.10 mm buccally and 1.27 mm on the palatal side (p < 0.05). In the mandible, cortical plates were 2.23 mm buccally and 2.02 mm lingually. Mandibular buccal and lingual cortical plates became thicker distally in the second and third molar areas. There was considerable variation in cortical thickness (from 0.25 to 5.50 mm). Based on interradicular distances, only 13% of measured sites in the maxilla were suitable for miniscrew insertion (≥3.3 mm), but 63% of sites were suitable in the mandible. This study showed considerable individual variation in bone thickness. Our data suggested that the palatal/lingual side may provide greater primary stability for miniscrews. The palatal area, between the second upper bicuspid and the first molar, appeared to be the most suitable area for tapered 7- to 9-mm miniscrews, starting at 1.5-2 mm from the alveolar crest. © 2011 John Wiley & Sons A/S.

Laterality and Left-sidedness in the Nose, Face, and Body: A New Finding.

PubMed

Hafezi, Farhad; Javdani, Ali; Naghibzadeh, Bijan; Ashtiani, Abbas Kazemi

2017-12-01

Asymmetry is a common occurrence in bilaterian animals, particularly human beings. Through examination of patients and their photographs during rhinoplasty, we noted wider left-sided nasal and facial features in most patients. This observation led us to hypothesize that this might be consistent to the whole body. We conducted a study in 3 parts to test the question above. First, we analyzed operating notes of 50 rhinoplasty patients to determine the wider side of the upper, middle, and lower thirds of the nose. Second, we analyzed the width of the face and chest wall in 31 patients to discern any correlation between facial and bodily asymmetry. Third, computerized tomographic scans of the thorax and body of 48 patients were studied to measure the width of the hemithorax and hemipelvic bone. (1) Upper vault width was wider on left side (78%). Left middle vault width was wider (88%). The lower lateral cartilage, lateral crura convexity was more prominent on left side (48%), and a wider scroll area was found and trimmed in 21 (left) and 0 (right) cases. The alar base was wider on left side (56%). (2) In the body and face analysis, 64.5% had a wider left-sided face and body. (3) In the computed tomographic scan analysis, same-sided thorax and pelvis asymmetry was seen (85.35%), 33 and 7 of which were left- and right-sided, respectively. We observed generalized asymmetry of the face and body with left-sided predominance.

Gas Turbine Engine Carbon Oil Seals Computerized Assembly

NASA Technical Reports Server (NTRS)

Lee, Robert

2006-01-01

In a bearing compartment there are a series of parts when assembled determine the location of the bearing and seal as related to the centerline of rotation. We see part datums that do not establish A coincident path from the bearing to the seal. High engine vibration can cause severe oil leakage. The inability of the seal to respond fast enough to the rotating element Radial Seal: Sensitive to housing air pressure Sensitive to seal runout ? Axial Seal: Very sensitive to seal perpendicularity to shaft. Goals include: 1) Repeatable assembly process; 2) Accurate assembly process; 3) Minimize seal runout; 4) Design to engine centerline of rotation, i.e. bearings.

A 5-year clinical and computerized tomographic implant follow-up in sinus-lifted maxillae and native bone.

PubMed

Sbordone, Carolina; Toti, Paolo; Ramaglia, Luca; Guidetti, Franco; Sbordone, Ludovico; Martuscelli, Ranieri

2014-09-01

The present study analysed apical and marginal bone remodelling around dental implants placed in both maxillary (sinus elevated with particulated autogenous osseous graft) and corresponding native bone areas, with a follow-up of 5 years. The clinical survival of implants was also observed. In this retrospective chart review, 27 patients were enrolled, with 55 dental implants inserted from 2000 to 2006, 26 of which were followed (one implant per patient); if required, patients were treated via sinus lift with autogenous bone and particulate technique. The internal controls were implants positioned in native areas beneath the sinus. Radiologic survey was assessed via computerized tomographic analysis measuring apical bone level (ABL) and marginal bone level (MBL), at 1- (T1 ), 3- (T2 ) and 5 years (T3 ), around implants (buccal, b; palatal, p; mesial, m; and distal sides, d). Clinical probing depth (CPD) and clinical attachment level (CAL) for all the four peri-implant aspects were measured. Cumulative survival rate (CSR) and survival rate (SR) of implants were calculated. Significances for paired and unpaired comparisons were searched for. A significant degree of apical resorption was recorded between T1 and T3 for the mesial particulate group; again, a significant difference was discovered between the native and particulate procedures for mABL. A further feature was discovered for the particulate procedure, for which ABLs resulted negative at least for three of the aspects. Regarding MBL measurements, similar behaviours were revealed using time-comparison analysis for the two procedures at the buccal aspect. Comparisons among diameters, irrespective of the procedure, showed that resorption times for the bMBL were shorter as the diameter of the implant became wider. The implant CSR was 92% in native areas (two failures/25 implants) and 93.3% in sinuses lifted with particulate bone (two failures/30 implants). The results suggest that a protrusion of the implant apices into augmented sinus lift occurred, whereas the bone remodelling of the coronal areas was not influenced by the events in the maxillary sinus. A diameter ranging from 4 to 5 mm might better guarantee a conservation of marginal peri-implant bone level compared with implants with smaller diameters. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of Sandostatin LAR on sleep apnoea in acromegaly: correlation with computerized tomographic cephalometry and hormonal activity.

PubMed

Ip, M S; Tan, K C; Peh, W C; Lam, K S

2001-10-01

Sleep apnoea has been reported to occur in subjects with acromegaly. This study evaluates the relationship among biochemical activity, sleep apnoeic activity and upper airway anatomic profile in acromegaly, and the effect of Sandostatin LAR, a long-acting somatostatin analogue, on these parameters. Fourteen subjects with acromegaly were recruited. Subjects were assessed at baseline and those with apnoea-hypopnoea index (AHI) > or = 5 were reassessed after 6 months of treatment with Sandostatin LAR 20-30 mg IMI 4-weekly. Biochemical activity was assessed with levels of GH and IGF-1. Sleep disordered breathing was assessed with overnight polysomnography. Upper airway anatomic profile was defined with computerized tomographic cephalometry. Of 14 subjects (age 42.0 +/- 8.1 years, mean +/- SD; 11 men) at baseline, there was a positive correlation between GH and tongue length (VT; P = 0.004), and between AHI and cephalometric indices: length of soft palate (PMU; P = 0.002); mandibular plane-hyoid bone distance (MPH; P = 0.017), maximum thickness of soft palate (Max-SP; P = 0.018) and VT (P = 0.027). Eight patients had sleep disordered breathing (AHI > or = 5) which was predominantly obstructive in nature (AHI = 29.4 +/- 22.6). After treatment, there were significant improvements in hormonal profile: GH, mU/l (before, 51.5 +/- 27.8; after, 8.0 +/- 7.4; P = 0.017) and IGF-1, nmol/l (before, 95.5 +/- 23.4; after, 35.0 +/- 12.4; P = 0.012); sleep-disordered breathing: AHI (before, 29.4 +/- 22.6; after, 13.4 +/- 11.12; P = 0.025), snoring episodes (before, 486 +/- 240; after, 165 +/- 170; P = 0.05); cephalometric indices, mm: MPH (before, 18.8 +/- 12.1; after, 14.8 +/- 8.4; P = 0.018), VT (before, 72.3 +/- 4.4; after, 69.7 +/- 4.3; P = 0.05). There was a positive correlation between the reduction in GH and AHI (r = 0.738, P = 0.037). The findings demonstrated that there was correlation between sleep apnoea severity and soft tissue overgrowth at the upper airway region in acromegaly. They also suggest that Sandostatin LAR improved obstructive sleep apnoea in acromegaly, and the effect might be partly mediated via a reduction in upper airway soft tissue, in particular that of the tongue, concomitant with a reduction in GH levels.

Seismic structure and segmentation of the axial valley of the Mid-Cayman Spreading Center

NASA Astrophysics Data System (ADS)

Van Avendonk, Harm J. A.; Hayman, Nicholas W.; Harding, Jennifer L.; Grevemeyer, Ingo; Peirce, Christine; Dannowski, Anke

2017-06-01

We report the results of a two-dimensional tomographic inversion of marine seismic refraction data from an array of ocean-bottom seismographs (OBSs), which produced an image of the crustal structure along the axial valley of the ultraslow spreading Mid-Cayman Spreading Center (MCSC). The seismic velocity model shows variations in the thickness and properties of the young oceanic crust that are consistent with the existence of two magmatic-tectonic segments along the 110 km long spreading center. Seismic wave speeds are consistent with exhumed mantle at the boundary between these two segments, but changes in the vertical gradient of seismic velocity suggest that volcanic crust occupies most of the axial valley seafloor along the seismic transect. The two spreading segments both have a low-velocity zone (LVZ) several kilometers beneath the seafloor, which may indicate the presence of shallow melt. However, the northern segment also has low seismic velocities (3 km/s) in a thick upper crustal layer (1.5-2.0 km), which we interpret as an extrusive volcanic section with high porosity and permeability. This segment hosts the Beebe vent field, the deepest known high-temperature black smoker hydrothermal vent system. In contrast, the southern spreading segment has seismic velocities as high as 4.0 km/s near the seafloor. We suggest that the porosity and permeability of the volcanic crust in the southern segment are much lower, thus limiting deep seawater penetration and hydrothermal recharge. This may explain why no hydrothermal vent system has been found in the southern half of the MCSC.

The Japan Lung Cancer Society–Japanese Society for Radiation Oncology consensus-based computed tomographic atlas for defining regional lymph node stations in radiotherapy for lung cancer

PubMed Central

Itazawa, Tomoko; Tamaki, Yukihisa; Komiyama, Takafumi; Nishimura, Yasumasa; Nakayama, Yuko; Ito, Hiroyuki; Ohde, Yasuhisa; Kusumoto, Masahiko; Sakai, Shuji; Suzuki, Kenji; Watanabe, Hirokazu; Asamura, Hisao

2017-01-01

The purpose of this study was to develop a consensus-based computed tomographic (CT) atlas that defines lymph node stations in radiotherapy for lung cancer based on the lymph node map of the International Association for the Study of Lung Cancer (IASLC). A project group in the Japanese Radiation Oncology Study Group (JROSG) initially prepared a draft of the atlas in which lymph node Stations 1–11 were illustrated on axial CT images. Subsequently, a joint committee of the Japan Lung Cancer Society (JLCS) and the Japanese Society for Radiation Oncology (JASTRO) was formulated to revise this draft. The committee consisted of four radiation oncologists, four thoracic surgeons and three thoracic radiologists. The draft prepared by the JROSG project group was intensively reviewed and discussed at four meetings of the committee over several months. Finally, we proposed definitions for the regional lymph node stations and the consensus-based CT atlas. This atlas was approved by the Board of Directors of JLCS and JASTRO. This resulted in the first official CT atlas for defining regional lymph node stations in radiotherapy for lung cancer authorized by the JLCS and JASTRO. In conclusion, the JLCS–JASTRO consensus-based CT atlas, which conforms to the IASLC lymph node map, was established. PMID:27609192

Noninvasive detection of coronary artery bypass graft patency by intravenous electron beam computed tomographic angiography.

PubMed

Yamakami, Shoji; Toyama, Junji; Okamoto, Mitsuhiro; Matsushita, Toyoaki; Murakami, Yoshimasa; Ogata, Masaki; Ito, Shigenori; Fukutomi, Tatsuya; Okayama, Naotsuka; Itoh, Makoto

2003-11-01

This study evaluates the usefullness of intravenous electron beam computed tomographic angiography (EBA) for the detection of coronary artery bypass graft patency in 43 patients (33 men and 10 women, mean age, 65 years) who had coronary artery bypass graft surgery. EBA was performed a few days before selective bypass graft angiography (SGA). Forty axial cross-sections of angiographic images of the heart were acquired consecutively by an electrocardiographic trigger signal at 40% of the RR interval, which corresponds to the end-systolic phase. EBA data were reconstructed as a three-dimensional shaded surface display of the heart and bypass grafts. Detectability of the patency of bypass gratis was evaluated, taking selective angiographic images of the bypass grafts as a gold standard. One hundred and nine grafts (96%) out of 114 grafts were subjected to evaluation: 37 grafts were left internal mammary artery grafts (LIMA), 7 were right internal mammary artery grafts (RIMA), 6 were gastroepiploic artery grafts (GEA), 7 were free gastroepiploic artery grafts with venous drainage (free-GEA), 7 were radial artery grafts (RAG), and 45 were saphenous vein gratis (SVG). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBA were 98%, 100%, 100%, 91%, and 98%, respectively. EBA sampled at the end-systolic period was determined to be useful for the detection of coronary artery bypass graft patency and occlusion.

Cone beam tomographic study of facial structures characteristics at rest and wide smile, and their correlation with the facial types.

PubMed

Martins, Luciana Flaquer; Vigorito, Julio Wilson

2013-01-01

To determine the characteristics of facial soft tissues at rest and wide smile, and their possible relation to the facial type. We analyzed a sample of forty-eight young female adults, aged between 19.10 and 40 years old, with a mean age of 30.9 years, who had balanced profile and passive lip seal. Cone beam computed tomographies were performed at rest and wide smile postures on the entire sample which was divided into three groups according to individual facial types. Soft tissue features analysis of the lips, nose, zygoma and chin were done in sagittal, axial and frontal axis tomographic views. No differences were observed in any of the facial type variables for the static analysis of facial structures at both rest and wide smile postures. Dynamic analysis showed that brachifacial types are more sensitive to movement, presenting greater sagittal lip contraction. However, the lip movement produced by this type of face results in a narrow smile, with smaller tooth exposure area when compared with other facial types. Findings pointed out that the position of the upper lip should be ahead of the lower lip, and the latter, ahead of the pogonion. It was also found that the facial type does not impact the positioning of these structures. Additionally, the use of cone beam computed tomography may be a valuable method to study craniofacial features.

Tomographic imaging of the transition from asthenospheric to lithospheric melt migration processes: 3-D structure of the topmost mantle and crust at the Endeavour Segment, Juan de Fuca Ridge

NASA Astrophysics Data System (ADS)

Arnoux, G. M.; Toomey, D. R.; Hooft, E. E. E.; Wilcock, W. S. D.

2017-12-01

We present tomographic images of the intermediate-spreading Endeavour Segment that constrain the nature of an axial magmatic system as it transitions from asthenospheric- to lithospheric-dominated rheologies. We use seismic energy from 5500 air gun shots refracted through the crust (Pg), reflected off the Moho (PmP), and refracted below the Moho (Pn)—as recorded by 64 OBSs from the Endeavour tomography experiment—to image the isotropic and anisotropic P-wave velocity structure of the topmost mantle and crust, as well as crustal thickness. At crustal depths, results reveal a low-velocity zone (LVZ)—inferred to be the axial magmatic system—that: (i) is continuous along the entire Endeavour Segment at depths of 2-3 km below seafloor and closely follows the axis of spreading, (ii) broadens and becomes more discontinuous at lower crustal depths, and (iii) has its largest amplitude from the mid- to lower-crust at the segment center. The ridge-tracking trend of the mid-crustal LVZ is in contrast to the crustal thickness pattern; in particular, a swath of thin crust is skewed with respect to both the ridge axis and the mid-crustal magmatic system and connects two overlapping spreading centers bounding the segment. The trend of thinner crust, however, is aligned with the mantle LVZ, which constrains the thermal structure and distribution of melt within the topmost mantle. The systematic depth variation of the map-view orientation and structure of the magmatic system indicates a distinct transition from a broad, cross-axis regime in the topmost asthenosphere governed by a regional, north-south trending thermal structure, to a narrow, cross-axis regime in the mid- to upper-crust governed by lithospheric rifting, magma injection, and hydrothermal processes. The lower-crustal magmatic system connects these two regimes. We also postulate that accumulation and differentiation of magma immediately beneath the crust-mantle boundary increases temperatures and suppresses plagioclase crystallization, thereby reducing the depth of lower crustal accretion and resulting in the observed north-south trending swath of thinner crust.

Peripapillary retinal nerve fiber layer thickness in a population of 6-year-old children: findings by optical coherence tomography.

PubMed

Huynh, Son C; Wang, Xiu Ying; Rochtchina, Elena; Mitchell, Paul

2006-09-01

To study the distribution of retinal nerve fiber layer (RNFL) thickness by ocular and demographic variables in a population-based study of young children. Population-based cross-sectional study. One thousand seven hundred sixty-five of 2238 (78.9%) eligible 6-year-old children participated in the Sydney Childhood Eye Study between 2003 and 2004. Mean age was 6.7 years (50.9% boys). Detailed examination included cycloplegic autorefraction and measurement of axial length. Retinal nerve fiber layer scans using an optical coherence tomographer were performed with a circular scan pattern of 3.4-mm diameter. Multivariate analyses were performed to examine the distribution of RNFL parameters with gender, ethnicity, axial length, and refraction. Peripapillary RNFL thickness and RNFL(estimated integral) (RNFL(EI)), which measures the total cross-sectional area of ganglion cell axons converging onto the optic nerve head. Peripapillary RNFL thickness and RNFL(EI) were normally distributed. The mean+/-standard deviation RNFL average thickness was 103.7+/-11.4 microm and RNFL(EI) was 1.05+/-0.12 mm2. Retinal nerve fiber layer thickness was least for the temporal quadrant (75.7+/-14.7 microm), followed by the nasal (81.7+/-19.6 microm), inferior (127.8+/-20.5 microm), and superior (129.5+/-20.6 microm) quadrants. Multivariate adjusted RNFL average thickness was marginally greater in boys than in girls (104.7 microm vs. 103.2 microm; P = 0.007) and in East Asian than in white children (107.7 microm vs. 102.7 microm; P<0.0001). The RNFL was thinner with greater axial length (P(trend)<0.0001) and less positive spherical equivalent refractions (P(trend) = 0.004). Retinal nerve fiber layer average thickness and RNFL(EI) followed a normal distribution. Retinal nerve fiber layer thickness varied marginally with gender, but differences were more marked between white and East Asian children. Retinal nerve fiber layer thinning was associated with increasing axial length and less positive refractions.

NECTAR—A fission neutron radiography and tomography facility

NASA Astrophysics Data System (ADS)

Bücherl, T.; Lierse von Gostomski, Ch.; Breitkreutz, H.; Jungwirth, M.; Wagner, F. M.

2011-09-01

NECTAR (Neutron Computerized Tomography and Radiography) is a versatile facility for radiographic and tomographic investigations as well as for neutron activation experiments using fission neutrons. The radiation sources for this facility are two plates of highly enriched uranium situated in the moderator vessel in FRM II. Thermal neutrons originating from the main fuel element of the reactor generate in these plates fast neutrons. These can escape through a horizontal beam tube without moderation. The beam can be filtered and manipulated in order to reduce the accompanying gamma radiation and to match the specific experimental tasks. A summary of the main parameters required for experimental set-up and (quantitative) data evaluation is presented. The (measured) spectra of the neutron and gamma radiations are shown along with the effect of different filters on their behavior. The neutron and gamma fluxes, dose rates, L/ D-ratios, etc. and the main parameters of the actually used detection systems for neutron imaging are given, too.

An alternative method in mandibular fracture treatment: bone graft use instead of a plate.

PubMed

Alagöz, Murat Sahin; Uysal, Ahmet Cagri; Sensoz, Omer

2008-03-01

In the treatment of the mandibular fractures, one of the main principles is to use the least amount of foreign material. We present an alternative technique that the bone grafts harvested from the fracture borders or from the iliac crest were used instead of plates and the fixation was done with screws. In the study including 24 mandible fractures, the bone grafts harvested from the fracture borders were used in the 10 favorable fractures and the bone grafts harvested from the iliac crest were used in the 14 unfavorable fractures. In the combined mandible fractures, four fractures were fixated with titanium plates and the other side with the bone graft. The patients, who were followed up for 12 to 20 months, were evaluated with macroscopic occlusion, panoramic graphs, and three-dimensional computerized tomographs. The advantage of this technique of fixation with the autogenous tissue is reduced infection rates and reduced operation costs. In the pediatric patients, the second session operation of plate removal is not necessary.

Developmental ossification sequences of the appendicular and axial skeleton in Kuttanad duck embryos (Anas platyrhynchos domesticus)

PubMed Central

Firdous, A.D.; Maya, S.; Massarat, K.; Baba, M.A.

2016-01-01

The processes of ossification sequences are poorly investigated for birds in general, even for domestic and experimental species and when it comes to the waterfowl it is almost negligible. Such sequences constitute a rich source of data on character evolution, and may even provide phylogenetic information. A pre-hatch developmental study on ossification sequences of axial and appendicular skeletal system in Kuttanad duck embryos was undertaken using 78 viable embryos. From day 3 to day 7 of incubation no ossification densities were seen both by alizarin red staining and computerized radiography. The first indication of ossification as small ossification centers in skull bones, clavicle, scapula, humerus, radius and ulna in forelimb and ilium, pubis femur and fibula in hind limb were observed on the 9th day of incubation. The ossification of the body of the ribs started at the 11th day of incubation towards the proximal extremity. On day 13th the ossification process of vertebrae was started from cervical end. The variation in appearance of the ossification centers in different bones at different stages of incubation period suggests relative importance of phylogeny to the sequences. PMID:26862514

Manubriosternal dislocation with spinal fracture: A rare cause for delayed haemothorax.

PubMed

Kothari, Manish; Saini, Pramod; Shethna, Sunny; Dalvie, Samir

2015-01-01

Type 2 manubriosternal dislocations with concomitant spinal fracture are rare and may be associated with thoracic visceral injuries. The complication of delayed haemothorax has not been reported yet. We report a case of a young male who suffered manubriosternal dislocation with chance type thoracic spine fracture due to fall of a tree branch over his back. The haemothorax presented late on day three. The possible injury mechanism is discussed along with review of literature. We conclude that a lateral chest radiograph is indicated in spinal fracture patients complaining of midsternal pain. Computerized axial tomography scan of chest with contrast is indicated to rule out visceral injuries and a chest radiograph should be repeated before the patient is discharged to look for delayed haemothorax.

Whole-Body Single-Bed Time-of-Flight RPC-PET: Simulation of Axial and Planar Sensitivities With NEMA and Anthropomorphic Phantoms

NASA Astrophysics Data System (ADS)

Crespo, Paulo; Reis, João; Couceiro, Miguel; Blanco, Alberto; Ferreira, Nuno C.; Marques, Rui Ferreira; Martins, Paulo; Fonte, Paulo

2012-06-01

A single-bed, whole-body positron emission tomograph based on resistive plate chambers has been proposed (RPC-PET). An RPC-PET system with an axial field-of-view (AFOV) of 2.4 m has been shown in simulation to have higher system sensitivity using the NEMA NU2-1994 protocol than commercial PET scanners. However, that protocol does not correlate directly with lesion detectability. The latter is better correlated with the planar (slice) sensitivity, obtained with a NEMA NU2-2001 line-source phantom. After validation with published data for the GE Advance, Siemens TruePoint and TrueV, we study by simulation their axial sensitivity profiles, comparing results with RPC-PET. Planar sensitivities indicate that RPC-PET is expected to outperform 16-cm (22-cm) AFOV scanners by a factor 5.8 (3.0) for 70-cm-long scans. For 1.5-m scans (head to mid-legs), the sensitivity gain increases to 11.7 (6.7). Yet, PET systems with large AFOV provide larger coverage but also larger attenuation in the object. We studied these competing effects with both spherical- and line-sources immersed in a 27-cm-diameter water cylinder. For 1.5-m-long scans, the planar sensitivity drops one order of magnitude in all scanners, with RPC-PET outperforming 16-cm (22-cm) AFOV scanners by a factor 9.2 (5.3) without considering the TOF benefit. A gain in the effective sensitivity is expected with TOF iterative reconstruction. Finally, object scatter in an anthropomorphic phantom is similar for RPC-PET and modern, scintillator-based scanners, although RPC-PET benefits further if its TOF information is utilized to exclude scatter events occurring outside the anthropomorphic phantom.

NEMA NU 2-2007 performance measurements of the Siemens Inveon™ preclinical small animal PET system

PubMed Central

Kemp, Brad J; Hruska, Carrie B; McFarland, Aaron R; Lenox, Mark W; Lowe, Val J

2010-01-01

National Electrical Manufacturers Association (NEMA) NU 2-2007 performance measurements were conducted on the Inveon™ preclinical small animal PET system developed by Siemens Medical Solutions. The scanner uses 1.51 × 1.51 × 10 mm LSO crystals grouped in 20 × 20 blocks; a tapered light guide couples the LSO crystals of a block to a position-sensitive photomultiplier tube. There are 80 rings with 320 crystals per ring and the ring diameter is 161 mm. The transaxial and axial fields of view (FOVs) are 100 and 127 mm, respectively. The scanner can be docked to a CT scanner; the performance characteristics of the CT component are not included herein. Performance measurements of spatial resolution, sensitivity, scatter fraction and count rate performance were obtained for different energy windows and coincidence timing window widths. For brevity, the results described here are for an energy window of 350–650 keV and a coincidence timing window of 3.43 ns. The spatial resolution at the center of the transaxial and axial FOVs was 1.56, 1.62 and 2.12 mm in the tangential, radial and axial directions, respectively, and the system sensitivity was 36.2 cps kBq−1 for a line source (7.2% for a point source). For mouse- and rat-sized phantoms, the scatter fraction was 5.7% and 14.6%, respectively. The peak noise equivalent count rate with a noisy randoms estimate was 1475 kcps at 130 MBq for the mouse-sized phantom and 583 kcps at 74 MBq for the rat-sized phantom. The performance measurements indicate that the Inveon™ PET scanner is a high-resolution tomograph with excellent sensitivity that is capable of imaging at a high count rate. PMID:19321924

NEMA NU 2-2007 performance measurements of the Siemens Inveon™ preclinical small animal PET system

NASA Astrophysics Data System (ADS)

Kemp, Brad J.; Hruska, Carrie B.; McFarland, Aaron R.; Lenox, Mark W.; Lowe, Val J.

2009-04-01

National Electrical Manufacturers Association (NEMA) NU 2-2007 performance measurements were conducted on the Inveon™ preclinical small animal PET system developed by Siemens Medical Solutions. The scanner uses 1.51 × 1.51 × 10 mm LSO crystals grouped in 20 × 20 blocks; a tapered light guide couples the LSO crystals of a block to a position-sensitive photomultiplier tube. There are 80 rings with 320 crystals per ring and the ring diameter is 161 mm. The transaxial and axial fields of view (FOVs) are 100 and 127 mm, respectively. The scanner can be docked to a CT scanner; the performance characteristics of the CT component are not included herein. Performance measurements of spatial resolution, sensitivity, scatter fraction and count rate performance were obtained for different energy windows and coincidence timing window widths. For brevity, the results described here are for an energy window of 350-650 keV and a coincidence timing window of 3.43 ns. The spatial resolution at the center of the transaxial and axial FOVs was 1.56, 1.62 and 2.12 mm in the tangential, radial and axial directions, respectively, and the system sensitivity was 36.2 cps kBq-1 for a line source (7.2% for a point source). For mouse- and rat-sized phantoms, the scatter fraction was 5.7% and 14.6%, respectively. The peak noise equivalent count rate with a noisy randoms estimate was 1475 kcps at 130 MBq for the mouse-sized phantom and 583 kcps at 74 MBq for the rat-sized phantom. The performance measurements indicate that the Inveon™ PET scanner is a high-resolution tomograph with excellent sensitivity that is capable of imaging at a high count rate.

The Japan Lung Cancer Society-Japanese Society for Radiation Oncology consensus-based computed tomographic atlas for defining regional lymph node stations in radiotherapy for lung cancer.

PubMed

Itazawa, Tomoko; Tamaki, Yukihisa; Komiyama, Takafumi; Nishimura, Yasumasa; Nakayama, Yuko; Ito, Hiroyuki; Ohde, Yasuhisa; Kusumoto, Masahiko; Sakai, Shuji; Suzuki, Kenji; Watanabe, Hirokazu; Asamura, Hisao

2017-01-01

The purpose of this study was to develop a consensus-based computed tomographic (CT) atlas that defines lymph node stations in radiotherapy for lung cancer based on the lymph node map of the International Association for the Study of Lung Cancer (IASLC). A project group in the Japanese Radiation Oncology Study Group (JROSG) initially prepared a draft of the atlas in which lymph node Stations 1-11 were illustrated on axial CT images. Subsequently, a joint committee of the Japan Lung Cancer Society (JLCS) and the Japanese Society for Radiation Oncology (JASTRO) was formulated to revise this draft. The committee consisted of four radiation oncologists, four thoracic surgeons and three thoracic radiologists. The draft prepared by the JROSG project group was intensively reviewed and discussed at four meetings of the committee over several months. Finally, we proposed definitions for the regional lymph node stations and the consensus-based CT atlas. This atlas was approved by the Board of Directors of JLCS and JASTRO. This resulted in the first official CT atlas for defining regional lymph node stations in radiotherapy for lung cancer authorized by the JLCS and JASTRO. In conclusion, the JLCS-JASTRO consensus-based CT atlas, which conforms to the IASLC lymph node map, was established. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

D-dimer threshold increase with pretest probability unlikely for pulmonary embolism to decrease unnecessary computerized tomographic pulmonary angiography

PubMed Central

Hogg, Melanie M.; Courtney, D. Mark; Miller, Chadwick D.; Jones, Alan E.; Smithline, Howard A

2012-01-01

Background Increasing the threshold to define a positive D-dimer could reduce unnecessary computed tomographic pulmonary angiography (CTPA) for suspected PE but might increase rates of missed PE and missed pneumonia, the most common nonthromboembolic diagnosis seen on CTPA. Objective Measure the effect of doubling the standard D-dimer threshold for “PE unlikely” Revised Geneva (RGS) or Wells’ scores on the exclusion rate, frequency and size of missed PE and missed pneumonia. Methods Patients evaluated for suspected PE with 64-channel CTPA were prospectively enrolled from EDs and inpatient units of four hospitals. Pretest probability data were collected in real time and the D-dimer was measured in a central laboratory. Criterion standard was CPTA interpretation by two independent radiologists combined with clinical outcome at 30 days. Results Of 678 patients enrolled, 126 (19%) were PE+ and 93 (14%) had pneumonia. Use of either Wells≤4 or RGS≤6 produced similar results. For example, with RGS≤6 and standard threshold (<500 ng/mL), D-dimer was negative in 110/678 (16%), and 4/110 were PE+ (posterior probability 3.8%), and 9/110 (8.2%) had pneumonia. With RGS≤6 and a threshold <1000 ng/mL, D-dimer was negative in 208/678 (31%) and 11/208 (5.3%) were PE+, but 10/11 missed PEs were subsegmental, and none had concomitant DVT. Pneumonia was found in 12/208 (5.4%) with RGS≤6 and D-dimer<1000 ng/mL. Conclusions Doubling the threshold for a positive D-dimer with a PE unlikely pretest probability could reduce CTPA scanning with a slightly increased risk of missed isolated subsegmental PE, and no increase in rate of missed pneumonia. PMID:22284935

External and internal macromorphology in 3D-reconstructed maxillary molars using computerized X-ray microtomography.

PubMed

Bjørndal, L; Carlsen, O; Thuesen, G; Darvann, T; Kreiborg, S

1999-01-01

The aim of this study was to perform a qualitative analysis of the relationship between the external and internal macromorphology of the root complex and to use fractal dimension analysis to determine the correlation between the shape of the outer surface of the root and the shape of the root canal. On the basis of X-ray computed transaxial microtomography, a qualitative and quantitative analysis of the external and internal macromorphology of the root complex in permanent maxillary molars was performed using well-defined macromorphological variables and fractal dimension analysis. Five maxillary molars were placed between a microfocus X-ray tube with a focal spot size of 0.07 mm, a Thomson-SCF image intensifier, and a CCD camera compromising a detector for the tomograph. Between 100 and 240 tomographic 2D slices were made of each tooth. Assembling slices for 3D volume was carried out with subsequent median noise filtering. Segmentation into enamel, dentine and pulp space was achieved through thresholding followed by morphological filtering. Surface representations were then constructed. A useful visualization of the tooth was created by making the dental hard tissues transparent and the pulp chamber and root-canal system opaque. On this basis it became possible to assess the relationship between the external and internal macromorphology of the crown and root complex. There was strong agreement between the number, position and cross-section of the root canals and the number, position and degree of manifestation of the root complex macrostructures. Data from a fractal dimension analysis also showed a high correlation between the shape of the root canals and the corresponding roots. It is suggested that these types of 3D volumes constitute a platform for preclinical training in fundamental endodontic procedures.

Blunt trauma of bone structures of the chest--computed tomography vs multidetector computed tomography.

PubMed

Petrović, Kosta; Turkalj, Ivan; Stojanović, Sanja; Vucaj-Cirilović, Viktorija; Nikolić, Olivera; Stojiljković, Dragana

2013-08-01

Computerized tomography (CT), especially multidetector CT (MDCT), has had a revolutionary impact in diagnostic in traumatized patients. The aim of the study was to identify and compare the frequency of injuries to bone structures of the thorax displayed with 5-mm-thick axial CT slices and thin-slice (MDCT) examination with the use of 3D reconstructions, primarily multiplanar reformations (MPR). This prospective study included 61 patients with blunt trauma submitted to CT scan of the thorax as initial assessment. The two experienced radiologists inde pendently and separately described the findings for 5-mm-thick axial CT slices (5 mm CT) as in monoslice CT examination; MPR and other 3D reconstructions along with thin-slice axial sections which were available in modern MDCT technologies. After describing thin-slice examination in case of disagreement in the findings, the examiners redescribed thin-slice examination together which was ultimately considered as a real, true finding. No statistically significant difference in interobserver evaluation of 5 mm CT examination was recorded (p > 0.05). Evaluation of fractures of sternum with 5 mm CT and MDCT showed a statistically significant difference (p < 0.05) in favor of better display of injury by MDCT examination. MDCT is a powerful diagnostic tool that can describe higher number of bone fractures of the chest in traumatized patients compared to 5 mm CT, especially in the region of sternum for which a statistical significance was obtained using MPR. Moreover, the importance of MDCT is also set by easier and more accurate determination of the level of bone injury.

Using Cross-Sectional Imaging to Convey Organ Relationships: An Integrated Learning Environment for Students of Gross Anatomy

PubMed Central

Forman, Bruce H.; Eccles, Randy; Piggins, Judith; Raila, Wayne; Estey, Greg; Barnett, G. Octo

1990-01-01

We have developed a visually oriented, computer-controlled learning environment designed for use by students of gross anatomy. The goals of this module are to reinforce the concepts of organ relationships and topography by using computed axial tomographic (CAT) images accessed from a videodisc integrated with color graphics and to introduce students to cross-sectional radiographic anatomy. We chose to build the program around CAT scan images because they not only provide excellent structural detail but also offer an anatomic orientation (transverse) that complements that used in the dissection laboratory (basically a layer-by-layer, anterior-to-posterior, or coronal approach). Our system, built using a Microsoft Windows-386 based authoring environment which we designed and implemented, integrates text, video images, and graphics into a single screen display. The program allows both user browsing of information, facilitated by hypertext links, and didactic sessions including mini-quizzes for self-assessment.

MICROCOMPUTED TOMOGRAPHIC, MORPHOMETRIC, AND HISTOPATHOLOGIC ASSESSMENT OF CONGENITAL BONE MALFORMATIONS IN TWO NEOTROPICAL VIPERIDS.

PubMed

de Carvalho, Marcelo Pires Nogueira; Sant'Anna, Sávio Stefanini; Grego, Kathleen Fernandes; de Campos Fonseca-Pinto, Ana Carolina Brandão; Lorigados, Carla Aparecida Batista; Queiroz-Hazarbassanov, Nicolle Gilda Teixeira; Catão-Dias, José Luiz

2017-10-01

Congenital malformations have been reported in all classes of vertebrates and may be a determinant of life span and survival. In reptiles, the incidence of congenital malformations can be associated with genetic and environmental causes, including pollution. The characterization of pathological processes involved in the development of congenital malformations of bone in snakes is rare in the literature, but is of great relevance in the field of reptile conservation and environmental health. We describe congenital bone lesions in 50 newborn jararaca (Bothrops jararaca) and 26 South American rattlesnakes (Crotalus durissus terrificus) born from wild-caught pregnant females in Southeastern Brazil. Lesions were evaluated by morphometric quantitative analysis, x-ray microtomography, and histopathologic descriptive analysis. Morphometric analysis showed that jararaca presented more severe axial lesions (kyphosis, scoliosis, and kyphoscoliosis) than rattlesnakes. Female rattlesnakes presented more severe axial lesions than did males. In rattlesnakes, spinal deformities were more frequently diagnosed in the caudal segment of the body. We present x-ray microtomographic assessments and images of malformed snakes (n=9) and characterized novel malformations, such as the agenesis of frontal, parietal, and supraoccipital bones in a jararaca specimen. Histopathologic findings included vertebral body fusion, myositis, coagulation necrosis, and disorganization of periaxial muscle fibers. The new methods and results presented in this study will be useful and informative for future research in pathology, teratology, embryology, and ecotoxicology in snakes.

Development of a High Precision Axial 3-D PET for Brain Imaging

NASA Astrophysics Data System (ADS)

Bolle, E.; Braem, A.; Casella, C.; Chesi, E.; Clinthorne, N.; Cochran, E.; De Leo, R.; Dissertori, G.; Djambazov, L.; Honscheid, K.; Huh, S.; Johnson, I.; Joram, C.; Kagan, H.; Lacasta, C.; Lustermann, W.; Meddi, F.; Nappi, E.; Nessi-Tedaldi, F.; Oliver, J. F.; Pauss, F.; Rafecas, M.; Renker, D.; Rudge, A.; Schinzel, D.; Schneider, T.; Séguinot, J.; Smith, S.; Solevi, P.; Stapnes, S.; Vilardi, I.; Weilhammer, P.

2009-12-01

We describe a PET device based on a novel method to extract the coordinates of the interaction point of the 511keV γ rays from 100 mm long and thin LYSO (Lutetium Yttrium OxyorthoSilicate) scintillator bars, positioned axially in the tomograph. The coordinate along the hit crystal is measured by using a hodoscope of Wave Length Shifting (WLS) plastic strips mounted perpendicularly to each plane of scintillators. As photodetectors, new Geiger mode Avalanche PhotoDetectors (G-APDs) with integrated electronics are being used to detect both the hit crystal in a block (x and y coordinates) and the interaction point in the crystal (z coordinate) through the light escaping from the crystal and transmitted to the WLS strips. In this way, the γ interaction point can be determined with a spatial resolution of few cubic millimeters down to a minimum deposited energy of about 50 keV, resulting in a volumetric precision very close to the limits imposed by the physics of the positron annihilation. The method allows to increase the detection efficiency without affecting the spatial resolution by adding scintillator planes in the radial direction. A demonstrator scanner, based on two matrices of 8 × 6 LYS crystals and 312 WLS strips, slotted in between the crystals, is under construction. Preliminary results from the feasibility studies of the various components will be presented.

Ultrasonic multi-skip tomography for pipe inspection

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

Volker, Arno; Zon, Tim van

The inspection of wall loss corrosion is difficult at pipe supports due to limited accessibility. The recently developed ultrasonic Multi-Skip screening technique is suitable for this problem. The method employs ultrasonic transducers in a pitch-catch geometry positioned on opposite sides of the pipe support. Shear waves are transmitted in the axial direction within the pipe wall, reflecting multiple times between the inner and outer surfaces before reaching the receivers. Along this path, the signals accumulate information on the integral wall thickness (e.g., via variations in travel time). The method is very sensitive in detecting the presence of wall loss, butmore » it is difficult to quantify both the extent and depth of the loss. Multi-skip tomography has been developed to reconstruct the wall thickness profile along the axial direction of the pipe. The method uses model-based full wave field inversion; this consists of a forward model for predicting the measured wave field and an iterative process that compares the predicted and measured wave fields and minimizes the differences with respect to the model parameters (i.e., the wall thickness profile). Experimental results are very encouraging. Various defects (slot and flat bottom hole) are reconstructed using the tomographic inversion. The general shape and width are well recovered. The current sizing accuracy is in the order of 1 mm.« less

East Pacific Rise axial structure from a joint tomographic inversion of traveltimes picked on downward continued and standard shot gathers collected by 3D MCS surveying

NASA Astrophysics Data System (ADS)

Newman, Kori; Nedimović, Mladen; Delescluse, Matthias; Menke, William; Canales, J. Pablo; Carbotte, Suzanne; Carton, Helene; Mutter, John

2010-05-01

We present traveltime tomographic models along closely spaced (~250 m), strike-parallel profiles that flank the axis of the East Pacific Rise at 9°41' - 9°57' N. The data were collected during a 3D (multi-streamer) multichannel seismic (MCS) survey of the ridge. Four 6-km long hydrophone streamers were towed by the ship along three along-axis sail lines, yielding twelve possible profiles over which to compute tomographic models. Based on the relative location between source-receiver midpoints and targeted subsurface structures, we have chosen to compute models for four of those lines. MCS data provide for a high density of seismic ray paths with which to constrain the model. Potentially, travel times for ~250,000 source-receiver pairs can be picked over the 30 km length of each model. However, such data density does not enhance the model resolution, so, for computational efficiency, the data are decimated so that ~15,000 picks per profile are used. Downward continuation of the shot gathers simulates an experimental geometry in which the sources and receivers are positioned just above the sea floor. This allows the shallowest sampling refracted arrivals to be picked and incorporated into the inversion whereas they would otherwise not be usable with traditional first-arrival travel-time tomographic techniques. Some of the far-offset deep-penetrating 2B refractions cannot be picked on the downward continued gathers due to signal processing artifacts. For this reason, we run a joint inversion by also including 2B traveltime picks from standard shot gathers. Uppermost velocity structure (seismic layer 2A thickness and velocity) is primarily constrained from 1D inversion of the nearest offset (<500 m) source-receiver travel-time picks for each downward continued shot gather. Deeper velocities are then computed in a joint 2D inversion that uses all picks from standard and downward continued shot gathers and incorporates the 1D results into the starting model. The resulting velocity models extend ~1 km into the crust. Preliminary results show thicker layer 2A and faster layer 2A velocities at fourth order ridge segment boundaries. Additionally, layer 2A thickens north of 9° 52' N, which is consistent with earlier investigations of this ridge segment. Slower layer 2B velocities are resolved in the vicinity of documented hydrothermal vent fields. We anticipate that additional analyses of the results will yield further insight into fine scale variations in near-axis mid-ocean ridge structure.

The use of microtomography in bone tissue and biomaterial three-dimensional analysis.

PubMed

Bedini, Rossella; Meleo, Deborah; Pecci, Raffaella; Pacifici, Luciano

2009-01-01

X-ray computed microtomography (micro-CT, microComputerised Tomography) is a miniaturized form of conventional computerized axial tomography (CAT ). This sophisticated technology enables 3D riconstruction of the internal structure of small X-ray opaque objects without sample destruction or preparation. The aim of this study is to show the possible applications of micro-CT in the analysis of bone graft materials of different origins (i.e. homologous, heterologous, alloplastic) in order to define their morphometric properties by means of SkyScan 1072 3D microtomography system. Since there is a close relationship between the properties of the materials and their microstructure, it is necessary to examine them using the highest levels of resolution before being able to improve existing materials or create new products.

Volume changes of autogenous bone after sinus lifting and grafting procedures: a 6-year computerized tomographic follow-up.

PubMed

Sbordone, Carolina; Toti, Paolo; Guidetti, Franco; Califano, Luigi; Bufo, Pantaleo; Sbordone, Ludovico

2013-04-01

To evaluate long-term bone remodelling of autografts over time (annually, for 6 years), comparing the block and particulate bone procedures for sinus floor elevation, as well as to evaluate the survival of positioned dental implants. Twenty-three sinus lift procedures with autogenous bone were performed: seven sinus lift procedures using particulate graft and 10 with block autogenous bone were performed in 17 patients. Employing a software program, pre- and post-surgical computerized tomography (CT) scans were used to compare the volume (V) and density (D) of inlay grafts over time (up to 6 years), and to determine the percentage of remaining bone (%R). All variable (V, D and %R) measurements were then compared statistically. At the 6-year survey for block form, a resorption of 21.5% was seen, whereas for particulate grafts there was a resorption of 39.2%. Both groups exhibited bone remodelling between the first and second follow-up which was significant regarding volume for the block form and regarding density for the particulate group. During the initial period of healing, the cortico-cancellous block bone grafted into the maxillary sinus underwent a negative remodelling of the volume, which is most probably due to graft cortex resorption, coupled with, primarily, an increase in density in the spongious area; for the particulate grafts, significant augmentations in density were obtained. The lack of significant differences among volumes was due to the wide degree of dispersion of the data. The rough data presented in this paper seem to support the use of a bone-block grafting procedure in maxillary sinus augmentation. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Surgically Assisted Rapid Palatomaxillary Expansion With or Without Pterygomaxillary Disjunction: A Systematic Review and Meta-Analysis.

PubMed

Hamedi Sangsari, Adrien; Sadr-Eshkevari, Pooyan; Al-Dam, Ahmed; Friedrich, Reinhard E; Freymiller, Earl; Rashad, Ashkan

2016-02-01

The purpose of this review was to evaluate the outcome measurements of anterior expansion, posterior expansion, and complications after surgically assisted rapid palatal expansion (SARPE) with or without pterygomaxillary disjunction (PMD). A computerized database search was performed using PubMed, CINAHL, Cochrane, Scopus, and Web of Science. Then, a computerized search was conducted in Google Scholar and ProQuest to overcome publication bias. From the original 125 combined results, 3 met the inclusion criteria. The Quality Assessment Tool for Quantitative Studies of the Effective Public Health Practice Project assessed 2 articles as weak and 1 as moderate. The systematic review included a total of 48 patients (11 male and 37 female). For 25 patients, SARPE was performed with PMD and for 23 patients SARPE was performed without PMD. A tooth-borne fixed hyrax-type palatal expansion screw appliance was used for all cases, activated 1 to 2 mm intraoperatively, and, after a latency period of 3 to 7 days, activated 0.5 to 0.6 mm per day for 38 patients and 0.25 mm for the other 10 until adequate expansion. Postexpansion retention was performed using ligature wired hyrax in 18 patients for 4 months. Comparisons were based on cone-beam computed tomographic projections, study models only, or a combination of study models, anteroposterior cephalometric radiographs, and occlusal radiographs. The time to measure the changes ranged from before fixed orthodontic retention to 6 months after the completion of active expansion. A meta-analysis was possible only for anterior (intercanine) and posterior (inter-molar) dental expansions. The literature is inconclusive regarding the effect of PMD on the outcomes of SARPE. Further controlled trials are needed. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Assessment of the Biomechanical Performance of 5 Plating Techniques in Fixation of Mandibular Subcondylar Fracture Using Finite Element Analysis.

PubMed

Darwich, Mhd Ayham; Albogha, Mhd Hassan; Abdelmajeed, Adnan; Darwich, Khaldoun

2016-04-01

The aim of this study was to compare the performances of 5 plating techniques for fixation of unilateral mandibular subcondylar fracture. Five titanium plating techniques for fixation of condylar fracture were analyzed using the finite element method. The modeled techniques were 1) 1 straight plate, 2) 2 parallel straight plates, 3) 2 angulated straight plates, 4) 1 trapezoidal plate, and 5) 1 square plate. Three-dimensional models were generated using patient-specific geometry for the mandible obtained from a computerized tomographic image of a healthy living man. Plates were designed and combined with the mandible and analyzed under a 500-N load. The single straight plate presented the most inferior performance; it presented maximum displacement and strain on cortical bone. The trapezoidal plate induced the least amount of strain on cortical bone and was best at resisting displacement. The trapezoidal plate is recommended for fixation of subcondylar fracture. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Peritoneal mesothelioma presenting as an acute surgical abdomen due to jejunal perforation.

PubMed

Salemis, Nikolaos S; Tsiambas, Evangelos; Gourgiotis, Stavros; Mela, Ageliki; Karameris, Andreas; Tsohataridis, Efstathios

2007-11-01

Peritoneal mesothelioma is a rare disease associated with poor prognosis. Acute abdomen as the first presentation is an extremely rare occurrence. We report an exceptional case of a patient who was found to have a jejunal perforation due to infiltration of peritoneal mesothelioma. A 62-year-old man was admitted with clinical signs of peritonitis. Computerized tomographic scans showed a mass distal to the ligament of Treitz, thickening of the mesentery and a small amount of ascites. Emergency laparotomy revealed a perforated tumor 15 cm distal to the ligament of Treitz and diffuse peritoneal disease. Segmental small bowel resection and suboptimal cytoreduction were performed. Histopathology and immunohistochemistry showed infiltration of malignant mesothelioma. During the postoperative period pleural mesothelioma was also diagnosed. Despite adjuvant chemotherapy, the patient died of disseminated progressive disease 7 months after surgery. Peritoneal mesothelioma is a rare malignancy with grim prognosis. Small bowel involvement is a poor prognostic indicator. Our case of a small bowel perforation due to direct infiltration by peritoneal mesothelioma appears to be the first reported in the English literature.

Current Trends in the Management of Abdominal Aortic Aneurysms

PubMed Central

Harris, K.A.; Ameli, F. Michael; Louis, E.L. St.

1987-01-01

The treatment of abdominal aortic aneurysm has undergone dramatic changes over the last three decades. More sophisticated diagnostic techniques have allowed early elective repair to be carried out. Improvement has resulted in both morbidity and mortality rates. Investigations such as ultrasound, computerized tomographic scanning and arteriography allow easy confirmation of the diagnosis of aortic aneurysms and permit a better assessment of the extent prior to surgical intervention. Improvement in the pre-operative management, particularly in relation to cardiac, renal, and pulmonary disease, has led to greatly improved results. The most important change in surgical technique has been repair of the aneurysm rather than resection. Combined with better post-operative intensive care units, this development has contributed to the improved morbidity and mortality rates. Although the complication rate of elective repair is low, the major cause of death remains myocardial infarction. As a result of all these improvements, indication for repair of abdominal aortic aneurysms has been extended to patients over the age of 80. Following surgical repair, most patients can be expected to return to normal lifestyles and lifespans. ImagesFigure 2Figure 3Figure 4 PMID:21263973

Treatment of a Common Iliac Aneurysm by Endovascular Exclusion Using the Amplatzer Vascular Plug and Femorofemoral Crossover Graft

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

Coupe, Nicholas J., E-mail: optimus2050@hotmail.com; Ling, Lynn; Cowling, Mark G.

2009-07-15

We report our initial experience using the Amplatzer Vascular Plug II (AVP2) in the treatment of a left common iliac aneurysm. Following investigation by computerized tomographic angiography and catheter angiography, a 79-year-old man was found to have a markedly tortuous iliac system, with a left common iliac artery aneurysm that measured 48 mm in maximal diameter. Due to the patient's age and comorbidities the surgical opinion was that conventional open repair was not suitable. However, due to the tortuous nature of the aneurysm and iliac vessels, standard endovascular repair, using either a bifurcated or an aorto-uni-iliac stent graft, was alsomore » not possible. A combined approach was used by embolizing the ipsilateral internal iliac artery using coils and excluding the aneurysm using two AVP2 occlusion devices, followed by femorofemoral crossover grafting. Total aneurysm occlusion was achieved using this method and this allowed the patient to have a much less invasive surgical procedure than with conventional open repair of common iliac aneurysms, thus avoiding potential comorbidity and mortality.« less

Computed tomographic anatomy of the equine foot.

PubMed

Claerhoudt, S; Bergman, E H J; Saunders, J H

2014-10-01

This study describes a detailed computed tomographic reference of the normal equine foot. Ten forefeet of five adult cadavers, without evidence of orthopaedic disease, were used. Computed tomography (CT) was performed on all feet. Two-millimetre thick transverse slices were obtained, and sagittal and dorsal planes were reformatted. The CT images were matched with the corresponding anatomic slices. The phalanges and the distal sesamoid bone showed excellent detail. The extensor and flexor tendons (including their attachments) could be clearly evaluated. The collateral (sesamoidean) ligaments could be readily located, but were difficult to delineate at their proximal attachment. The distal digital annular ligament could only be distinguished from the deep digital flexor tendon proximal to the distal sesamoid bone, and its proximal attachment could be identified, but not its distal insertion. Small ligaments (impar ligament, chondrosesamoidean, chondrocoronal and chondrocompedal ligaments, axial and abaxial palmar ligaments of the proximal inter-phalangeal joint) were seen with difficulty and not at all slices. The joint capsules could not be delineated from the surrounding soft tissue structures. The lateral and medial proprius palmar digital artery and vein could be visualized occasionally on some slices. The ungular cartilages, corium and hoof wall layering were seen. The nerves, the articular and fibrocartilage of the distal sesamoid bone and the chondroungular ligament could not be assessed. Computed tomography of the equine foot can be of great value when results of radiography and ultrasonography are inconclusive. Images obtained in this study may serve as reference for CT of the equine foot. © 2013 Blackwell Verlag GmbH.

Video analysis of the biomechanics of a bicycle accident resulting in significant facial fractures.

PubMed

Syed, Shameer H; Willing, Ryan; Jenkyn, Thomas R; Yazdani, Arjang

2013-11-01

This study aimed to use video analysis techniques to determine the velocity, impact force, angle of impact, and impulse to fracture involved in a video-recorded bicycle accident resulting in facial fractures. Computed tomographic images of the resulting facial injury are presented for correlation with data and calculations. To our knowledge, such an analysis of an actual recorded trauma has not been reported in the literature. A video recording of the accident was split into frames and analyzed using an image editing program. Measurements of velocity and angle of impact were obtained from this analysis, and the force of impact and impulse were calculated using the inverse dynamic method with connected rigid body segments. These results were then correlated with the actual fracture pattern found on computed tomographic imaging of the subject's face. There was an impact velocity of 6.25 m/s, impact angles of 14 and 6.3 degrees of neck extension and axial rotation, respectively, an impact force of 1910.4 N, and an impulse to fracture of 47.8 Ns. These physical parameters resulted in clinically significant bilateral mid-facial Le Fort II and III pattern fractures. These data confer further understanding of the biomechanics of bicycle-related accidents by correlating an actual clinical outcome with the kinematic and dynamic parameters involved in the accident itself and yielding a concrete evidence of the velocity, force, and impulse necessary to cause clinically significant facial trauma. These findings can aid in the design of protective equipment for bicycle riders to help avoid this type of injury.

Improved method to visualize lipid distribution within arterial vessel walls by 1.7 μm spectroscopic spectral-domain optical coherence tomography

NASA Astrophysics Data System (ADS)

Hirano, Mitsuharu; Tonosaki, Shozo; Ueno, Takahiro; Tanaka, Masato; Hasegawa, Takemi

2014-02-01

We report an improved method to visualize lipid distribution in axial and lateral direction within arterial vessel walls by spectroscopic spectral-domain Optical Coherence Tomography (OCT) at 1.7μm wavelength for identification of lipidrich plaque that is suspected to cause coronary events. In our previous method, an extended InGaAs-based line camera detects an OCT interferometric spectrum from 1607 to 1766 nm, which is then divided into twenty subbands, and A-scan OCT profile is calculated for each subband, resulting in a tomographic spectrum. This tomographic spectrum is decomposed into lipid spectrum having an attenuation peak at 1730 nm and non-lipid spectrum independent of wavelength, and the weight of each spectrum, that is, lipid and non-lipid score is calculated. In this paper, we present an improved algorithm, in which we have combined the lipid score and the non-lipid score to derive a corrected lipid score. We have found that the corrected lipid score is better than the raw lipid score in that the former is more robust against false positive occurring due to abrupt change in reflectivity at vessel surface. In addition, we have optimized spatial smoothing filter and reduced false positive and false negative due to detection noise and speckle. We have verified this improved algorithm by the use of measuring data of normal porcine coronary artery and lard as a model of lipid-rich plaque and confirmed that both the sensitivity and the specificity of lard are 92%.

High-resolution imaging of biological tissue with full-field optical coherence tomography

NASA Astrophysics Data System (ADS)

Zhu, Yue; Gao, Wanrong

2015-03-01

A new full-field optical coherence tomography system with high-resolution has been developed for imaging of cells and tissues. Compared with other FF-OCT (Full-field optical coherence tomography, FF-OCT) systems illuminated with optical fiber bundle, the improved Köhler illumination arrangement with a halogen lamp was used in the proposed FF-OCT system. High numerical aperture microscopic objectives were used for imaging and a piezoelectric ceramic transducer (PZT) was used for phase-shifting. En-face tomographic images can be obtained by applying the five-step phase-shifting algorithm to a series of interferometric images which are recorded by a smart camera. Three-dimensional images can be generated from these tomographic images. Imaging of the chip of Intel Pentium 4 processor demonstrated the ultrahigh resolution of the system (lateral resolution is 0.8μm ), which approaches the theoretical resolution 0.7 μm× 0.5 μm (lateral × axial). En-face images of cells of onion show an excellent performance of the system in generating en-face images of biological tissues. Then, unstained pig stomach was imaged as a tissue and gastric pits could be easily recognized using FF-OCT system. Our study provides evidence for the potential ability of FFOCT in identifying gastric pits from pig stomach tissue. Finally, label-free and unstained ex vivo human liver tissues from both normal and tumor were imaged with this FFOCT system. The results show that the setup has the potential for medical diagnosis applications such liver cancer diagnosis.

[The importance of axial computer tomography of the neurocranium in neurotraumatology (1) (author's transl)].

PubMed

Gustorf, R

1979-07-01

Computer tomography enables exact diagnostic clarification of intracranial lesions in trauma of the neurocranium. Subdural or epidural as well as intracerebral haemorrhages can be localised, and a circumscribed contusion and cerebral oedema become tangible. The article reports on 90 patients subjected to computerized tomography following trauma of the neurocranium. In about 50% of the cases, the trauma had been caused by a traffic accident. About 27% of the accident victims were children and adolescents. In about one-half of the examined persons, subdural or epidural haemorrhages were found, whereas in about 20% of the cases, contusions, partly with mild haemorrhages, were seen. In about 10% of the cases a more or less severe oedema was seen. About 20% of the patients yielded no abnormal finding by CT in accordance with the age of the patient.

Laparoscopic optical coherence tomographic imaging of human ovarian cancer

NASA Astrophysics Data System (ADS)

Hariri, Lida P.; Bonnema, Garret T.; Schmidt, Kathy; Hatch, Kenneth; Brewer, Molly; Barton, Jennifer K.

2008-02-01

Ovarian cancer is the fourth leading cause of cancer-related death among women in the United States. If diagnosed at an early stage, the 5-year survival rate is 94%, but drops to 68% for regional disease and 29% for distant metastasis; only 19% of all cases are diagnosed at the early, localized stage. Optical coherence tomography is a recently emerging non-destructive imaging technology, achieving high axial resolutions (10-20 microns) at imaging depths up to 2 mm. Previously, we studied OCT imaging in normal and diseased human ovary ex vivo to determine the features OCT is capable of resolving. Changes in collagen were suggested with several of the images that correlated with changes in collagen seen in malignancy. Areas of necrosis and blood vessels were also visualized using OCT, indicative of an underlying tissue abnormality. We recently developed a custom side-firing laparoscopic OCT (LOCT) probe fabricated specifically for in vivo laparoscopic imaging. The LOCT probe consists of a 38 mm diameter handpiece terminated in an 280 mm long, 4.6 mm diameter tip for insertion into the laparoscopic trocar and is capable of obtaining up to 9.5 mm image lengths at 10 micron axial resolution. In this study, we utilize the LOCT probe to image one or both ovaries of 20 patients undergoing laparotomy or transabdominal endoscopy and oophorectomy to determine if OCT is capable of identifying and/or differentiating normal and neoplastic ovary. To date, we have laparoscopically imaged the ovaries of ten patients successfully with no known complications.

Impacts of Contracted Endodontic Cavities on Instrumentation Efficacy and Biomechanical Responses in Maxillary Molars.

PubMed

Moore, Brent; Verdelis, Konstantinos; Kishen, Anil; Dao, Thuan; Friedman, Shimon

2016-12-01

Recently, we reported that in mandibular molars contracted endodontic cavities (CECs) improved fracture strength compared with traditional endodontic cavities (TECs) but compromised instrumentation efficacy in distal canals. This study assessed the impacts of CECs on instrumentation efficacy and axial strain responses in maxillary molars. Eighteen extracted intact maxillary molars were imaged with micro-computed tomographic imaging (12-μm voxel), assigned to CEC or TEC groups (n = 9/group), and accessed accordingly. Canals were instrumented (V-Taper2H; SSWhite Dental, Lakewood, NJ) with 2.5% sodium hypochlorite irrigation, reimaged, and the proportion of the modified canal wall determined. Cavities were restored with bonded composite resin (TPH-Spectra-LV; Dentsply International, York, PA). Another 28 similar molars (n = 14/group) with linear strain gauges (Showa Measuring Instruments, Tokyo, Japan) attached to mesiobuccal and palatal roots were subjected to load cycles (50-150 N) in the Instron Universal Testing machine (Instron, Canton, MA), and the axial microstrain was recorded before access and after restoration. These 28 molars and additional 11 intact molars (control) were cyclically fatigued (1 million cycles, 5-50 N, 15 Hz) and subsequently loaded to failure. Data were analyzed by the Wilcoxon rank sum and Kruskal-Wallis tests (α = 0.05). The overall mean proportion of the modified canal wall did not differ significantly between CECs (49.7% ± 12.0%) and TECs (44.7% ± 9.0%). Relative changes in axial microstrain responses to load varied in both groups. The mean load at failure for CECs (1703 ± 558 N) did not differ significantly from TECs (1384 ± 377 N) and was significantly lower (P < .005) for both groups compared with intact molars (2457 ± 941 N). In maxillary molars tested in vitro, CECs did not impact instrumentation efficacy and biomechanical responses compared with TECs. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Fetal neurosonography using 3-dimensional multiplanar sonography].

PubMed

Chaoui, R; Heling, K S; Kainer, F; Karl, K

2012-04-01

This review focuses on the examination of the fetal brain, using three-dimensional (3D) ultrasound and the multiplanar rendering mode (MPR). The routine examination of the brain is achieved with axial planes but a dedicated fetal neurosonogram requires additional coronal and sagittal views, in order to provide a complete view of the different brain structures. Because these planes are difficult to obtain under many conditions, the present paper shows how 3D MPR allows one to obtain 1 or multiple reconstructed images from a digital volume. The display can be either as orthogonal planes, tomographic planes with parallel slices or as one single plane of the region of interest, which can be selected by the examiner. This approach allows easily the demonstration of the corpus callosum, the cerebellar vermis, the three-horn view, the foetal hippocampus and other regions. In addition, early neurosonography of the developing brain from the 7th week of pregnancy onwards can be achieved. © Georg Thieme Verlag KG Stuttgart · New York.

Monitoring tooth demineralization using a cross polarization optical coherence tomographic system with an integrated MEMS scanner

NASA Astrophysics Data System (ADS)

Fried, Daniel; Staninec, Michal; Darling, Cynthia; Kang, Hobin; Chan, Kenneth

2012-01-01

New methods are needed for the nondestructive measurement of tooth demineralization and remineralization to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-μm, it is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces. In this paper we present early results using a new cross-polarization OCT system introduced by Santec. This system utilizes a swept laser source and a MEMS scanner for rapid acquisition of cross polarization images. Preliminary studies show that this system is useful for measurement of the severity of demineralization on tooth surfaces and for showing the spread of occlusal lesions under the dentinal-enamel junction.

Wavelength-encoded tomography based on optical temporal Fourier transform

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

Zhang, Chi; Wong, Kenneth K. Y., E-mail: kywong@eee.hku.hk

We propose and demonstrate a technique called wavelength-encoded tomography (WET) for non-invasive optical cross-sectional imaging, particularly beneficial in biological system. The WET utilizes time-lens to perform the optical Fourier transform, and the time-to-wavelength conversion generates a wavelength-encoded image of optical scattering from internal microstructures, analogous to the interferometery-based imaging such as optical coherence tomography. Optical Fourier transform, in principle, comes with twice as good axial resolution over the electrical Fourier transform, and will greatly simplify the digital signal processing after the data acquisition. As a proof-of-principle demonstration, a 150 -μm (ideally 36 μm) resolution is achieved based on a 7.5-nm bandwidth swept-pump,more » using a conventional optical spectrum analyzer. This approach can potentially achieve up to 100-MHz or even higher frame rate with some proven ultrafast spectrum analyzer. We believe that this technique is innovative towards the next-generation ultrafast optical tomographic imaging application.« less

Optical Coherence Tomography Findings of Exophytic Retinal Capillary Hemangiomas of the Posterior Pole

PubMed Central

Chin, Eric K.; Trikha, Rupan; Morse, Lawrence S.; Zawadzki, Robert J.; Werner, John S.; Park, Susanna S.

2013-01-01

Exophytic retinal capillary hemangiomas (RCH) can be a diagnostic challenge in subjects without von Hippel-Lin-dau disease (VHL). This report of two cases describes the optical coherence tomographic (OCT) characteristics of RCH in two eyes of a subject with VHL and in one eye of an otherwise normal subject. Three different OCT instruments were used (Stratus, Cirrus and/or custom high resolution Fourier-domain OCT with 4.5 μm axial resolution) depending on availability. All instruments localized the tumor to the outer retina. A sharp border between the tumor and overlying inner retina was noted. The tumor bulged into the subretinal space and showed marked shadowing. Associated cystoid macular edema and sub-retinal fluid were noted. High-resolution Fourier-domain OCT showed a focal photoreceptor layer rip in the adjacent tumor-free macula in one eye with poor vision after treatment. OCT may be a useful tool in diagnosing RCH and studying associated morphologic changes. PMID:20337341

Validation of a Monte Carlo simulation of the Inveon PET scanner using GATE

NASA Astrophysics Data System (ADS)

Lu, Lijun; Zhang, Houjin; Bian, Zhaoying; Ma, Jianhua; Feng, Qiangjin; Chen, Wufan

2016-08-01

The purpose of this study is to validate the application of GATE (Geant4 Application for Tomographic Emission) Monte Carlo simulation toolkit in order to model the performance characteristics of Siemens Inveon small animal PET system. The simulation results were validated against experimental/published data in accordance with the NEMA NU-4 2008 protocol for standardized evaluation of spatial resolution, sensitivity, scatter fraction (SF) and noise equivalent counting rate (NECR) of a preclinical PET system. An agreement of less than 18% was obtained between the radial, tangential and axial spatial resolutions of the simulated and experimental results. The simulated peak NECR of mouse-size phantom agreed with the experimental result, while for the rat-size phantom simulated value was higher than experimental result. The simulated and experimental SFs of mouse- and rat- size phantom both reached an agreement of less than 2%. It has been shown the feasibility of our GATE model to accurately simulate, within certain limits, all major performance characteristics of Inveon PET system.

Design of the first optical system for real-time tomographic holography (RTTH)

NASA Astrophysics Data System (ADS)

Galeotti, John M.; Siegel, Mel; Rallison, Richard D.; Stetten, George

2008-08-01

The design of the first Real-Time-Tomographic-Holography (RTTH) optical system for augmented-reality applications is presented. RTTH places a viewpoint-independent real-time (RT) virtual image (VI) of an object into its actual location, enabling natural hand-eye coordination to guide invasive procedures, without requiring tracking or a head-mounted device. The VI is viewed through a narrow-band Holographic Optical Element (HOE) with built-in power that generates the largest possible near-field, in-situ VI from a small display chip without noticeable parallax error or obscuring direct view of the physical world. Rigidly fixed upon a medical-ultrasound probe, RTTH could show the scan in its actual location inside the patient, because the VI would move with the probe. We designed the image source along with the system-optics, allowing us to ignore both planer geometric distortions and field curvature, respectively compensated by using RT pre-processing software and attaching a custom-surfaced fiber-optic-faceplate (FOFP) to our image source. Focus in our fast, non-axial system was achieved by placing correcting lenses near the FOFP and custom-optically-fabricating our volume-phase HOE using a recording beam that was specially shaped by extra lenses. By simultaneously simulating and optimizing the system's playback performance across variations in both the total playback and HOE-recording optical systems, we derived and built a design that projects a 104x112 mm planar VI 1 m from the HOE using a laser-illuminated 19x16 mm LCD+FOFP image-source. The VI appeared fixed in space and well focused. Viewpoint-induced location errors were <3 mm, and unexpected first-order astigmatism produced 3 cm (3% of 1 m) ambiguity in depth, typically unnoticed by human observers.

Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors.

PubMed

Tombul, S T; Aki, F T; Gunay, M; Inci, K; Hazirolan, T; Karcaaltincaba, M; Erkan, I; Bakkaloglu, A; Yasavul, U; Bakkaloglu, M

2008-01-01

Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.

Bacteroides (Parabacteroides) distasonis splenic abscess in a sickle cell patient.

PubMed

Al-Tawfiq, Jaffar A

2008-01-01

Splenic abscess is not an uncommon complication of patients with sickle-cell disease. Here we describe an 18 year-old boy with sickle cell disease and left upper quadrant abdominal pain. Computerized axial tomography revealed left sided free flowing pleural effusion and splenomegaly with liquefaction and possible gas formation. The splenic fluid grew an unusual organism known as Bacteroides distasonis. The patient received antimicrobial therapy and underwent a splenectomy with full recovery. The spleen was cystically infarcted and measured 22 x 16 x 5 cm. The capsule was thickened and covered by fibrinous exudate. Histopathologic examination of the spleen showed complete necrosis with reparative fibrosis. This case presents an unusual cause of splenic abscess due to Bacteroides distasonis with a subacute to chronic course. The presence of fever and left sided pleuritic chest pain in patients with sickle cell disease should raise the suspicion of splenic abscess.

Distribution of Hydrothermal Activity at the Lau ISS: Possible Controlling Parameters

NASA Astrophysics Data System (ADS)

Martinez, F.; Baker, E. T.; Resing, J. A.; Edwards, M. H.; Walker, S. L.; Buck, N.

2008-12-01

Seismic tomographic studies of intermediate to fast spreading rate mid-ocean ridges (MORs) interpret zones of rapid crustal cooling a few (3-4) km off axis surrounding the axial seismic low velocity zone (LVZ). These zones of rapid cooling also broadly correlate with the initiation and growth of large abyssal hill faults. The close association of both high thermal gradients and development of fault permeability at crustal scales suggests the hypothesis that these areas may be favorable locations for off-axis high temperature hydrothermal activity. In March-May 2008 on R/V Kilo Moana we conducted a near-bottom sidescan sonar and oceanographic survey along the Eastern Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR) in the Lau back-arc basin to map the distribution of hydrothermal activity within this region. The survey utilized the deep-towed DSL120A (IMI120) sonar, an array of miniature autonomous plume recorders (MAPRs) attached to the tow cable and tethered beneath the sonar's depressor weight, an in situ chemical scanner (VISA) and 23 CTD hydrocasts (see Baker et al., this session). At the ELSC the survey spanned ~100 x 10 km area encompassing the ABE, Tow Cam and Kilo Moana vent fields with ~ 1 km spaced lines overall and ~500 m spaced lines in the area of the ABE vent field. On the VFR the survey spanned a distance of ~100 km along axis by ~5 km across axis with 700 m spaced lines encompassing the Vai Lili, Mariner and Tui Malila vent sites. Initial results identified particle plumes, indicative of high temperature venting, only within about a km of the ridge axis at the ELSC and VFR with possible diffuse venting indicated by MAPR oxidation-reduction potential (ORP) measurements at flank sites at VFR. The expanded sonar coverage better defines the volcano-tectonic context of the hydrothermal signals and previously mapped vent sites. Initial results suggest, however, no high-T venting more than about 1 km from the ridge axis, an apparently negative test of the above hypothesis. This may suggest that hydrothermal fluids are efficiently channeled to the axis even if cooling off-axis crustal regions. Alternatively, at the back-arc VFR/ELSC subduction controls on magmatic productivity may play an important role in modifying the usual relationships observed at MORs among spreading rate, seismic low velocity zone width, faulting, sedimentation and hydrothermal activity. For example, the fast spreading ELSC is magmatically deficient for its spreading rate, forms a deep faulted axial floor and has no continuous axial magma lens seismic reflector. This may lead to a narrower LVZ at the ELSC relative to MORs spreading at the same rate. At the intermediate rate and arc- proximal VFR excess magmatic productivity and volatile-rich volcanics form a peaked shallow axis, few flanking faults and a sediment drape of volcaniclastics from the ridge axis (and nearby arc volcanoes). These effects may act to suppress fault-related permeability on ridge flanks or may rapidly blanket ridge-flanking hydrothermal systems. Some of these issues may be further clarified when planned seismic tomographic and moored hydrophone studies are carried out beginning next year at the ELSC/VFR.

Association of Brachial-Ankle Pulse Wave Velocity with Asymptomatic Intracranial Arterial Stenosis in Hypertension Patients.

PubMed

Wang, Yan; Zhang, Jin; Qain, Yuesheng; Tang, Xiaofeng; Ling, Huawei; Chen, Kemin; Li, Yan; Gao, Pingjin; Zhu, Dingliang

2016-08-01

Intracranial arterial stenosis is a common cause of ischemic stroke in Asians. We therefore sought to explore the relationship of brachial-ankle pulse wave velocity and intracranial arterial stenosis in 834 stroke-free hypertensive patients. Intracranial arterial stenosis was evaluated through computerized tomographic angiography. Brachial-ankle pulse wave velocity was measured by an automated cuff device. The top decile of brachial-ankle pulse wave velocity was significantly associated with intracranial arterial stenosis (P = .027, odds ratio = 1.82; 95% confidence interval: 1.07-3.10). The patients with the top decile of brachial-ankle pulse wave velocity showed 56% higher risk for the presence of intracranial arterial stenosis to the whole population, which was more significant in patients younger than 65 years old. We also found that brachial-ankle pulse wave velocity related to both intracranial arterial stenosis and homocysteine. Our study showed the association of brachial-ankle pulse wave velocity with asymptomatic intracranial arterial stenosis in hypertension patients, especially in relative younger subjects. Brachial-ankle pulse wave velocity might be a relatively simple and repeatable measurement to detect hypertension patients in high risk of intracranial arterial stenosis. Copyright © 2016. Published by Elsevier Inc.

Role of CT scanning in formation evaluation

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

Bergosh, J.L.; Dibona, B.G.

1988-01-01

The use of the computerized tomographic (CT) scanner in formation evaluation of difficult to analyze core samples has moved from the research and development phase to daily, routine use in the core-analysis laboratory. The role of the CT scanner has become increasingly important as geologists try to obtain more representative core material for accurate formation evaluation. The most common problem facing the core analyst when preparing to measure petrophysical properties is the selection of representative and unaltered core samples for routine and special core testing. Recent data have shown that heterogeneous reservoir rock can be very difficult, if not impossible,more » to assess correctly when using standard core examination procedures, because many features, such as fractures, are not visible on the core surface. Another problem is the invasion of drilling mud into the core sample. Flushing formation oil and water from the core can greatly alter the saturation and distribution of fluids and lead to serious formation evaluation problems. Because the quality and usefulness of the core date are directly tied to proper sample selection, it has become imperative that the CT scanner be used whenever possible.« less

Chondro-manubrial deformity and bifid rib, rare variations seen in pectus carinatum: a radiological finding.

PubMed

Allwyn Joshua, S; Shetty, Lathika; Pare, V S; Sebastian, Roopa

2013-07-01

Pectus carinatum or protrusion deformity of chest wall is less frequently occurring anterior chest wall deformity when compared to pectus excavatum. It may be classified as type 1 or chondro-gladiolar and type 2 or chondro-manubrial deformity. Other variations seen are symmetrical and asymmetrical pectus carinatum. Here we present two unique case reports, one with chondro-manubrial deformity (Currarino-Silverman syndrome) and other with asymmetrical pectus carinatum having bifid rib which are some of the rare variations seen in pectus carinatum found during Computerized tomographic examination. Currarino-Silverman syndrome is a type 2 pectus carinatum, a rare deformity with chondro-manubrial involvement and usually associated congenital heart diseases. Early fusion of sternal plates is one of the known theories in producing this deformity. On the other hand, asymmetrical pectus deformity are usually seen due to imbalance or abnormality in growth plates of costal cartilages leading to forked rib or bifid rib, which are accidently seen on radiological examination. To conclude, our reports would help in differential diagnosis from frequently occurring conditions affecting chest like chondro-gladiolar deformity, pectus excavatum, chest wall tumours, rib fractures and intra thoracic ribs.

Tomographic diagnostics of nonthermal plasmas

NASA Astrophysics Data System (ADS)

Denisova, Natalia

2009-10-01

In the previous work [1], we discussed a ``technology'' of tomographic method and relations between the tomographic diagnostics in thermal (equilibrium) and nonthermal (nonequilibrium) plasma sources. The conclusion has been made that tomographic reconstruction in thermal plasma sources is the standard procedure at present, which can provide much useful information on the plasma structure and its evolution in time, while the tomographic reconstruction of nonthermal plasma has a great potential at making a contribution to understanding the fundamental problem of substance behavior in strongly nonequilibrium conditions. Using medical terminology, one could say, that tomographic diagnostics of the equilibrium plasma sources studies their ``anatomic'' structure, while reconstruction of the nonequilibrium plasma is similar to the ``physiological'' examination: it is directed to study the physical mechanisms and processes. The present work is focused on nonthermal plasma research. The tomographic diagnostics is directed to study spatial structures formed in the gas discharge plasmas under the influence of electrical and gravitational fields. The ways of plasma ``self-organization'' in changing and extreme conditions are analyzed. The analysis has been made using some examples from our practical tomographic diagnostics of nonthermal plasma sources, such as low-pressure capacitive and inductive discharges. [0pt] [1] Denisova N. Plasma diagnostics using computed tomography method // IEEE Trans. Plasma Sci. 2009 37 4 502.

Preoperative evaluation of renal anatomy and renal masses with helical CT, 3D-CT and 3D-CT angiography.

PubMed

Toprak, Uğur; Erdoğan, Aysun; Gülbay, Mutlu; Karademir, Mehmet Alp; Paşaoğlu, Eşref; Akar, Okkeş Emrah

2005-03-01

The aim of this prospective study was to determine the efficacy of three-dimensional computed tomography (3D-CT) and three-dimensional computed tomographic angiography (3D-CTA) that were reconstructed by using the axial images of the multiphasic helical CT in the preoperative evaluation of renal masses and demonstration of renal anatomy. Twenty patients that were suspected of having renal masses upon initial physical examination and ultrasonographic evaluation were examined through multiphasic helical CT. Two authors executed CT evaluations. Axial images were first examined and then used to reconstruct 3D-CT and 3D- CTA images. Number, location and size of the renal masses and other findings were noted. Renal vascularization and relationships of the renal masses with the neighboring renal structures were further investigated with 3D-CT and 3D-CTA images. Out of 20 patients, 13 had histopathologically proven renal cell carcinoma. The diagnoses of the remaining seven patients were xanthogranulomatous pyelonephritis, abscess, simple cyst, infected cyst, angiomyolipoma, oncocytoma and arteriovenous fistula. In the renal cell carcinoma group, 3 patients had stage I, 7 patients had stage II, and 3 patients had stage III disease. Sizes of renal cell carcinoma masses were between 23 mm to 60 mm (mean, 36 mm). Vascular invasion was shown in 2 renal cell carcinoma patients. Collecting system invasion was identified in 11 of 13 renal cell patients. These radiologic findings were confirmed with surgical specimens. Three-dimensional CT and 3D-CTA are non-invasive, effective imaging techniques for the preoperative evaluation of renal masses.

Preoperative magnetic resonance imaging protocol for endoscopic cranial base image-guided surgery.

PubMed

Grindle, Christopher R; Curry, Joseph M; Kang, Melissa D; Evans, James J; Rosen, Marc R

2011-01-01

Despite the increasing utilization of image-guided surgery, no radiology protocols for obtaining magnetic resonance (MR) imaging of adequate quality are available in the current literature. At our institution, more than 300 endonasal cranial base procedures including pituitary, extended pituitary, and other anterior skullbase procedures have been performed in the past 3 years. To facilitate and optimize preoperative evaluation and assessment, there was a need to develop a magnetic resonance protocol. Retrospective Technical Assessment was performed. Through a collaborative effort between the otolaryngology, neurosurgery, and neuroradiology departments at our institution, a skull base MR image-guided (IGS) protocol was developed with several ends in mind. First, it was necessary to generate diagnostic images useful for the more frequently seen pathologies to improve work flow and limit the expense and inefficiency of case specific MR studies. Second, it was necessary to generate sequences useful for IGS, preferably using sequences that best highlight that lesion. Currently, at our institution, all MR images used for IGS are obtained using this protocol as part of preoperative planning. The protocol that has been developed allows for thin cut precontrast and postcontrast axial cuts that can be used to plan intraoperative image guidance. It also obtains a thin cut T2 axial series that can be compiled separately for intraoperative imaging, or may be fused with computed tomographic images for combined modality. The outlined protocol obtains image sequences effective for diagnostic and operative purposes for image-guided surgery using both T1 and T2 sequences. Copyright © 2011 Elsevier Inc. All rights reserved.

Laparoscopic optical coherence tomographic imaging of human ovarian cancer

NASA Astrophysics Data System (ADS)

Hariri, Lida P.; Bonnema, Garret T.; Schmidt, Kathy; Korde, Vrushali; Winkler, Amy M.; Hatch, Kenneth; Brewer, Molly; Barton, Jennifer K.

2009-02-01

Ovarian cancer is the fourth leading cause of cancer-related death among women. If diagnosed at early stages, 5-year survival rate is 94%, but drops to 68% for regional disease and 29% for distant metastasis; only 19% of cases are diagnosed at early, localized stages. Optical coherence tomography is a recently emerging non-destructive imaging technology, achieving high axial resolutions (10-20 µm) at imaging depths up to 2 mm. Previously, we studied OCT in normal and diseased human ovary ex vivo. Changes in collagen were suggested with several images that correlated with changes in collagen seen in malignancy. Areas of necrosis and blood vessels were also visualized using OCT, indicative of an underlying tissue abnormality. We recently developed a custom side-firing laparoscopic OCT (LOCT) probe fabricated for in vivo imaging. The LOCT probe, consisting of a 38 mm diameter handpiece terminated in a 280 mm long, 4.6 mm diameter tip for insertion into the laparoscopic trocar, is capable of obtaining up to 9.5 mm image lengths at 10 µm axial resolution. In this pilot study, we utilize the LOCT probe to image one or both ovaries of 17 patients undergoing laparotomy or transabdominal endoscopy and oophorectomy to determine if OCT is capable of differentiating normal and neoplastic ovary. We have laparoscopically imaged the ovaries of seventeen patients with no known complications. Initial data evaluation reveals qualitative distinguishability between the features of undiseased post-menopausal ovary and the cystic, non-homogenous appearance of neoplastic ovary such as serous cystadenoma and endometroid adenocarcinoma.

Use of Noncontrast Computed Tomography and Computed Tomographic Perfusion in Predicting Intracerebral Hemorrhage After Intravenous Alteplase Therapy.

PubMed

Batchelor, Connor; Pordeli, Pooneh; d'Esterre, Christopher D; Najm, Mohamed; Al-Ajlan, Fahad S; Boesen, Mari E; McDougall, Connor; Hur, Lisa; Fainardi, Enrico; Shankar, Jai Jai Shiva; Rubiera, Marta; Khaw, Alexander V; Hill, Michael D; Demchuk, Andrew M; Sajobi, Tolulope T; Goyal, Mayank; Lee, Ting-Yim; Aviv, Richard I; Menon, Bijoy K

2017-06-01

Intracerebral hemorrhage is a feared complication of intravenous alteplase therapy in patients with acute ischemic stroke. We explore the use of multimodal computed tomography in predicting this complication. All patients were administered intravenous alteplase with/without intra-arterial therapy. An age- and sex-matched case-control design with classic and conditional logistic regression techniques was chosen for analyses. Outcome was parenchymal hemorrhage on 24- to 48-hour imaging. Exposure variables were imaging (noncontrast computed tomography hypoattenuation degree, relative volume of very low cerebral blood volume, relative volume of cerebral blood flow ≤7 mL/min·per 100 g, relative volume of T max ≥16 s with all volumes standardized to z axis coverage, mean permeability surface area product values within T max ≥8 s volume, and mean permeability surface area product values within ipsilesional hemisphere) and clinical variables (NIHSS [National Institutes of Health Stroke Scale], onset to imaging time, baseline systolic blood pressure, blood glucose, serum creatinine, treatment type, and reperfusion status). One-hundred eighteen subjects (22 patients with parenchymal hemorrhage versus 96 without, median baseline NIHSS score of 15) were included in the final analysis. In multivariable regression, noncontrast computed tomography hypoattenuation grade ( P <0.006) and computerized tomography perfusion white matter relative volume of very low cerebral blood volume ( P =0.04) were the only significant variables associated with parenchymal hemorrhage on follow-up imaging (area under the curve, 0.73; 95% confidence interval, 0.63-0.83). Interrater reliability for noncontrast computed tomography hypoattenuation grade was moderate (κ=0.6). Baseline hypoattenuation on noncontrast computed tomography and very low cerebral blood volume on computerized tomography perfusion are associated with development of parenchymal hemorrhage in patients with acute ischemic stroke receiving intravenous alteplase. © 2017 American Heart Association, Inc.

Tomographic Imaging of a Forested Area By Airborne Multi-Baseline P-Band SAR.

PubMed

Frey, Othmar; Morsdorf, Felix; Meier, Erich

2008-09-24

In recent years, various attempts have been undertaken to obtain information about the structure of forested areas from multi-baseline synthetic aperture radar data. Tomographic processing of such data has been demonstrated for airborne L-band data but the quality of the focused tomographic images is limited by several factors. In particular, the common Fourierbased focusing methods are susceptible to irregular and sparse sampling, two problems, that are unavoidable in case of multi-pass, multi-baseline SAR data acquired by an airborne system. In this paper, a tomographic focusing method based on the time-domain back-projection algorithm is proposed, which maintains the geometric relationship between the original sensor positions and the imaged target and is therefore able to cope with irregular sampling without introducing any approximations with respect to the geometry. The tomographic focusing quality is assessed by analysing the impulse response of simulated point targets and an in-scene corner reflector. And, in particular, several tomographic slices of a volume representing a forested area are given. The respective P-band tomographic data set consisting of eleven flight tracks has been acquired by the airborne E-SAR sensor of the German Aerospace Center (DLR).

A cost-utility analysis of the use of preoperative computed tomographic angiography in abdomen-based perforator flap breast reconstruction.

PubMed

Offodile, Anaeze C; Chatterjee, Abhishek; Vallejo, Sergio; Fisher, Carla S; Tchou, Julia C; Guo, Lifei

2015-04-01

Computed tomographic angiography is a diagnostic tool increasingly used for preoperative vascular mapping in abdomen-based perforator flap breast reconstruction. This study compared the use of computed tomographic angiography and the conventional practice of Doppler ultrasonography only in postmastectomy reconstruction using a cost-utility model. Following a comprehensive literature review, a decision analytic model was created using the three most clinically relevant health outcomes in free autologous breast reconstruction with computed tomographic angiography versus Doppler ultrasonography only. Cost and utility estimates for each health outcome were used to derive the quality-adjusted life-years and incremental cost-utility ratio. One-way sensitivity analysis was performed to scrutinize the robustness of the authors' results. Six studies and 782 patients were identified. Cost-utility analysis revealed a baseline cost savings of $3179, a gain in quality-adjusted life-years of 0.25. This yielded an incremental cost-utility ratio of -$12,716, implying a dominant choice favoring preoperative computed tomographic angiography. Sensitivity analysis revealed that computed tomographic angiography was costlier when the operative time difference between the two techniques was less than 21.3 minutes. However, the clinical advantage of computed tomographic angiography over Doppler ultrasonography only showed that computed tomographic angiography would still remain the cost-effective option even if it offered no additional operating time advantage. The authors' results show that computed tomographic angiography is a cost-effective technology for identifying lower abdominal perforators for autologous breast reconstruction. Although the perfect study would be a randomized controlled trial of the two approaches with true cost accrual, the authors' results represent the best available evidence.

Prostate seed implant quality assessment using MR and CT image fusion.

PubMed

Amdur, R J; Gladstone, D; Leopold, K A; Harris, R D

1999-01-01

After a seed implant of the prostate, computerized tomography (CT) is ideal for determining seed distribution but soft tissue anatomy is frequently not well visualized. Magnetic resonance (MR) images soft tissue anatomy well but seed visualization is problematic. We describe a method of fusing CT and MR images to exploit the advantages of both of these modalities when assessing the quality of a prostate seed implant. Eleven consecutive prostate seed implant patients were imaged with axial MR and CT scans. MR and CT images were fused in three dimensions using the Pinnacle 3.0 version of the ADAC treatment planning system. The urethra and bladder base were used to "line up" MR and CT image sets during image fusion. Alignment was accomplished using translation and rotation in the three ortho-normal planes. Accuracy of image fusion was evaluated by calculating the maximum deviation in millimeters between the center of the urethra on axial MR versus CT images. Implant quality was determined by comparing dosimetric results to previously set parameters. Image fusion was performed with a high degree of accuracy. When lining up the urethra and base of bladder, the maximum difference in axial position of the urethra between MR and CT averaged 2.5 mm (range 1.3-4.0 mm, SD 0.9 mm). By projecting CT-derived dose distributions over MR images of soft tissue structures, qualitative and quantitative evaluation of implant quality is straightforward. The image-fusion process we describe provides a sophisticated way of assessing the quality of a prostate seed implant. Commercial software makes the process time-efficient and available to any clinical practice with a high-quality treatment planning system. While we use MR to image soft tissue structures, the process could be used with any imaging modality that is able to visualize the prostatic urethra (e.g., ultrasound).

Self-propelled in-tube shuttle and control system for automated measurements of magnetic field alignment

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

Boroski, W.N.; Nicol, T.H.; Pidcoe, S.V.

1990-03-01

A magnetic field alignment gauge is used to measure the field angle as a function of axial position in each of the magnets for the Superconducting Super Collider (SSC). Present measurements are made by manually pushing the through the magnet bore tube and stopping at intervals to record field measurements. Gauge location is controlled through graduation marks and alignment pins on the push rods. Field measurements are recorded on a logging multimeter with tape output. Described is a computerized control system being developed to replace the manual procedure for field alignment measurements. The automated system employs a pneumatic walking devicemore » to move the measurement gauge through the bore tube. Movement of the device, called the Self-Propelled In-Tube Shuttle (SPITS), is accomplished through an integral, gas driven, double-acting cylinder. The motion of the SPITS is transferred to the bore tube by means of a pair of controlled, retractable support feet. Control of the SPITS is accomplished through an RS-422 interface from an IBM-compatible computer to a series of solenoid-actuated air valves. Direction of SPITS travel is determined by the air-valve sequence, and is managed through the control software. Precise axial position of the gauge within the magnet is returned to the control system through an optically-encoded digital position transducer attached to the shuttle. Discussed is the performance of the transport device and control system during preliminary testing of the first prototype shuttle. 1 ref., 7 figs.« less

Tomographic Reconstruction from a Few Views: A Multi-Marginal Optimal Transport Approach

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

Abraham, I., E-mail: isabelle.abraham@cea.fr; Abraham, R., E-mail: romain.abraham@univ-orleans.fr; Bergounioux, M., E-mail: maitine.bergounioux@univ-orleans.fr

2017-02-15

In this article, we focus on tomographic reconstruction. The problem is to determine the shape of the interior interface using a tomographic approach while very few X-ray radiographs are performed. We use a multi-marginal optimal transport approach. Preliminary numerical results are presented.

Optimization of an ultralow-dose high-resolution pediatric PET scanner design based on monolithic scintillators with dual-sided digital SiPM readout: a simulation study

NASA Astrophysics Data System (ADS)

Mikhaylova, Ekaterina; Tabacchini, Valerio; Borghi, Giacomo; Mollet, Pieter; D'Hoe, Ester; Schaart, Dennis R.; Vandenberghe, Stefaan

2017-11-01

The goal of this simulation study is the performance evaluation and comparison of six potential designs for a time-of-flight PET scanner for pediatric patients of up to about 12 years of age. It is designed to have a high sensitivity and provide high-contrast and high-resolution images. The simulated pediatric PET is a full ring scanner, consisting of 32  ×  32 mm2 monolithic LYSO:Ce crystals coupled to digital silicon photomultiplier arrays. The six considered designs differ in axial lengths (27.2 cm, 54.4 cm and 102 cm) and crystal thicknesses (22 mm and 11 mm). The simulations are based on measured detector response data. We study two possible detector arrangements: 22 mm-thick crystals with dual-sided readout and 11 mm-thick crystals with back-sided readout. The six designs are simulated by means of the GEANT4 application for tomographic emission software, using the measured spatial, energy and time response of the monolithic scintillator detectors as input. The performance of the six designs is compared on the basis of four studies: (1) spatial resolution; (2) NEMA NU2-2012 sensitivity and scatter fraction (SF) tests; (3) non-prewhitening signal-to-noise ratio observer study; and (4) receiver operating characteristics analysis. Based on the results, two designs are identified as cost-effective solutions for fast and efficient imaging of children: one with 54.4 cm axial field-of-view (FOV) and 22 mm-thick crystals, and another one with 102 cm axial FOV and 11 cm-thick crystals. The first one has a higher center point sensitivity than the second one, but requires dual-sided readout. The second design has the advantage of allowing a whole-body scan in a single bed position acquisition. Both designs have the potential to provide an excellent spatial resolution (˜2 mm) and an ultra-high sensitivity (>100 cps kBq-1 ).

Computed tomographic anatomy of the nasal cavity, paranasal sinuses and tympanic cavity of the koala.

PubMed

Hemsley, S; Palmer, H; Canfield, R B; Stewart, M E B; Krockenberger, M B; Malik, R

2013-09-01

To use cross-sectional imaging (helical computed tomography (CT)) combined with conventional anatomical dissection to define the normal anatomy of the nasal cavity and bony cavitations of the koala skull. Helical CT scans of the heads of nine adult animals were obtained using a multislice scanner acquiring thin slices reconstructed in the transverse, sagittal and dorsal planes. Subsequent anatomical dissection permitted confirmation of correct identification and further delineation of bony and air-filled structures visible in axial and multiplanar reformatted CT images. The nasal cavity was relatively simple, with little scrolling of nasal conchae, but bony cavitations were complex and extensive. A rostral maxillary recess and ventral conchal, caudal maxillary, frontal and sphenoidal paranasal sinuses were identified and characterised. Extensive temporal bone cavitation was shown to be related to a large epitympanic recess. The detailed anatomical data provided are applicable to future functional and comparative anatomical studies, as well as providing a preliminary atlas for clinical investigation of conditions such as cryptococcal rhinosinusitis, a condition more common in the koala than in many other species. © 2013 Australian Veterinary Association.

Partial double-layered patella in a nondysplasic adolescent.

PubMed

García-Mata, Serafín; Hidalgo-Ovejero, Angel

2016-11-01

Double-layered patella (DLP) is a rare patella-formation abnormality reported in association with multiple epiphyseal dysplasia. DLP is one of the five types of bipartite patella, caused by a coronal septum that divides the patella into anterior and posterior segments. Although the double layer of bone has been reported as complete, it may also manifest as partial, as in our case. A 13-year-old male patient attended A&E after accidentally falling and sustaining a direct injury to his left knee, with pain in the anterior surface of the right patella. He was diagnosed with an incomplete vertical fracture of the left patella. An axial view radiography indicated an external partial DLP. No bone dysplasia was found. Computed tomographic scan and MRI showed partial DLP and bone marrow oedema because of the injury in the femoral condyle, but no fracture. The reason for highlighting this type of patella abnormality is to present the case of a patient without bone dysplasia, either partial or incomplete, that has not been reported previously. We also wish to emphasize the importance of not confusing it with a fracture in standard radiographies.

Modelling polymeric deformable granular materials - from experimental data to numerical models at the grain scale

NASA Astrophysics Data System (ADS)

Teil, Maxime; Harthong, Barthélémy; Imbault, Didier; Peyroux, Robert

2017-06-01

Polymeric deformable granular materials are widely used in industry and the understanding and the modelling of their shaping process is a point of interest. This kind of materials often presents a viscoelasticplastic behaviour and the present study promotes a joint approach between numerical simulations and experiments in order to derive the behaviour law of such granular material. The experiment is conducted on a polystyrene powder on which a confining pressure of 7MPa and an axial pressure reaching 30MPa are applied. Between different steps of the in-situ test, the sample is scanned in an X-rays microtomograph in order to know the structure of the material depending on the density. From the tomographic images and by using specific algorithms to improve the images quality, grains are automatically identified, separated and a finite element mesh is generated. The long-term objective of this study is to derive a representative sample directly from the experiments in order to run numerical simulations using a viscoelactic or viscoelastic-plastic constitutive law and compare numerical and experimental results at the particle scale.

3D perfusion mapping in the intact mouse heart after myocardial infarction using myocardial contrast echocardiography

NASA Astrophysics Data System (ADS)

Li, Yinbo; Yang, Zequan; French, Brent A.; Hossack, John A.

2005-04-01

An intact mouse model of surgically-induced myocardial infarction (MI) caused by permanent occlusion of the Left Anterior Descending (LAD) coronary artery was studied. Normal mice with no occlusion were also studied as controls. For each mouse, contrast enhanced ultrasound images of the heart were acquired in parallel cross-sections perpendicular to the sternum at millimeter increments. For accurate 3D reconstruction, ECG gating and a tri-axial adjustable micromanipulator were used for temporal and spatial registration. Ultrasound images at steady-state of blood refilling were color-coded in each slice to show relative perfusion. Myocardial perfusion defects and necrosis were also examined postmortem by staining with Phthalo blue and TTC red dyes. Good correlation (R>0.93) in perfused area size was observed between in vivo measurements and histological staining. A 3D multi-slice model and a 3D rendering of perfusion distribution were created and showed a promising match with postmortem results, lending further credence to its use as a more comprehensive and more reliable tool for in vivo assessment of myocardial perfusion than 2D tomographic analysis.

Transversal craniofacial growth evaluated on children dry skulls using V2 and V 3 canal openings as references.

PubMed

Harnet, J C; Lombardi, T; Manière-Ezvan, A; Chamorey, E; Kahn, J L

2013-11-01

The aim of this study was to investigate the transversal relationships between two cephalometric landmarks and lines on the face using ovale, rotundum, greater palatine and infra-orbital foramina as references. Thirty-four children dry skulls, 19 males and 15 females aged 0-6 years, were examined by computed tomography scanning by using constructed tomographic axial and frontal planes. The cephalometric transversal dimensions of the face skull were measured between the right and left landmarks from the orbital lateral wall and from the zygomatic arch. The cephalometric transversal dimensions of the base skull were measured between the right and left ovale, rotundum, greater palatine and infra-orbital foramina. Statistical analysis using partial correlations, regardless of the age, showed strong relationships (p < 0.05) among transversal measurements with nerve canal openings and transversal distances of skull face. We showed that the cranial base transversal growth was very strongly related to facial transversal growth from the postnatal period up to 6 years of age.

Computed Tomographic Pattern of Physiological Intracranial Calcifications in a City in Central Africa

PubMed Central

Uduma, Uduma Felix; Pius, Fokam; Mathieu, Motah

2012-01-01

Objective: Intracranial calcifications underlie certain brain diseases which may be de novo or systemic. But calclfications un-connected to pathologies are classified physiological. Aim: To evaluate physiological intracranial calcifications in Douala with establishment of earliest age range of detection. Materials and Methods: Prospective study of brain computed tomograms was done from April to October 2009 using Schumadzu CT Scan machine. Axial, reconstructed and bone window images as well Hounsfield unit measurements were used for final evaluations. Results were analysed with SSPS 3. Results: 132 patients with 75 males and 57 females were studied and 163 separate calcifications were identified due to co-existent calcifications. The highest calcification was in choroid plexi, constituiting 56.82% of the studied population. This was followed by pineal gland. Both were commonly co-existent with advancing age. These calcifications were first seen at 10-19years. No type of physiological intracranial calcification was seen below age 10. The least calcification of 0.76% of population was in dentate nucleus. Conclusion: No intra-cranial physiological calcifications started earlier than 9years in Douala, a city in Cameroon, Central Africa. PMID:22980109

Computed tomographic pattern of physiological intracranial calcifications in a city in central Africa.

PubMed

Uduma, Felix Uduma; Pius, Fokam; Mathieu, Motah

2011-12-29

Intracranial calcifications underlie certain brain diseases which may be de novo or systemic. But calcifications un-connected to pathologies are classified physiological. To evaluate physiological intracranial calcifications in Douala with establishment of earliest age range of detection. Prospective study of brain computed tomograms was done from April to October 2009 using Schumadzu CT Scan machine. Axial, reconstructed and bone window images as well Hounsfield unit measurements were used for final evaluations. RESULTS were analysed with SSPS 3. 132 patients with 75 males and 57 females were studied and 163 separate calcifications were identified due to co-existent calcifications. The highest calcification was in choroid plexi, constituting 56.82% of the studied population. This was followed by pineal gland. Both were commonly co-existent with advancing age. These calcifications were first seen at 10-19 years. No type of physiological intracranial calcification was seen below age 10. The least calcification of 0.76% of population was in dentate nucleus. No intra-cranial physiological calcifications started earlier than 9 years in Douala, a city in Cameroon, Central Africa.

Massive Intrapelvic Hematoma after a Pubic Ramus Fracture in an Osteoporotic Patient

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

Haruki, Funao, E-mail: hfunao@yahoo.co.jp; Takahiro, Koyanagi

2016-03-24

An 88-year-old female presented with a left thigh pain and dysuria. She visited our hospital 2 week after she noticed her symptoms. She stated that she might have a low-energy fall, but she could not identify the exact onset. Her radiograph of the pelvis (Figure 1) showed displaced left pubic ramus fracture. Her computed tomographic scanning of the pelvis (Figure 2) showed massive intrapelvic hematoma (axial size, 11 cm by 5 cm) around the fracture site, although she did not use any anticoagulants. Because her bone mineral density was 0.357 g/cm{sup 2}, and T score was -4.8 SD, she startedmore » a bisphosphonate therapy. She received a bed-rest physical therapy for 6 weeks, and the hematoma regressed spontaneously. She started full weight bearing after 6 weeks, and walked by a walker after 8 weeks. Although it is extremely rare to develop massive chronic intra-pelvic hematoma after a lowenergy pubic ramus fracture without any use of anticoagulants, it may occur in elderly and severely osteoporotic patient.« less

Reducing radiation dose without compromising image quality in preoperative perforator flap imaging with CTA using ASIR technology.

PubMed

Niumsawatt, Vachara; Debrotwir, Andrew N; Rozen, Warren Matthew

2014-01-01

Computed tomographic angiography (CTA) has become a mainstay in preoperative perforator flap planning in the modern era of reconstructive surgery. However, the increased use of CTA does raise the concern of radiation exposure to patients. Several techniques have been developed to decrease radiation dosage without compromising image quality, with varying results. The most recent advance is in the improvement of image reconstruction using an adaptive statistical iterative reconstruction (ASIR) algorithm. We sought to evaluate the image quality of ASIR in preoperative deep inferior epigastric perforator (DIEP) flap surgery, through a direct comparison with conventional filtered back projection (FBP) images. A prospective review of 60 consecutive ASIR and 60 consecutive FBP CTA images using similar protocol (except for radiation dosage) was undertaken, analyzed by 2 independent reviewers. In both groups, we were able to accurately identify axial arteries and their perforators. Subjective analysis of image quality demonstrated no statistically significant difference between techniques. ASIR can thus be used for preoperative imaging with similar image quality to FBP, but with a 60% reduction in radiation delivery to patients.

System and method for generating motion corrected tomographic images

DOEpatents

Gleason, Shaun S [Knoxville, TN; Goddard, Jr., James S.

2012-05-01

A method and related system for generating motion corrected tomographic images includes the steps of illuminating a region of interest (ROI) to be imaged being part of an unrestrained live subject and having at least three spaced apart optical markers thereon. Simultaneous images are acquired from a first and a second camera of the markers from different angles. Motion data comprising 3D position and orientation of the markers relative to an initial reference position is then calculated. Motion corrected tomographic data obtained from the ROI using the motion data is then obtained, where motion corrected tomographic images obtained therefrom.

Optical tomographic memories: algorithms for the efficient information readout

NASA Astrophysics Data System (ADS)

Pantelic, Dejan V.

1990-07-01

Tomographic alogithms are modified in order to reconstruct the inf ormation previously stored by focusing laser radiation in a volume of photosensitive media. Apriori information about the position of bits of inf ormation is used. 1. THE PRINCIPLES OF TOMOGRAPHIC MEMORIES Tomographic principles can be used to store and reconstruct the inf ormation artificially stored in a bulk of a photosensitive media 1 The information is stored by changing some characteristics of a memory material (e. g. refractive index). Radiation from the two independent light sources (e. g. lasers) is f ocused inside the memory material. In this way the intensity of the light is above the threshold only in the localized point where the light rays intersect. By scanning the material the information can be stored in binary or nary format. When the information is stored it can be read by tomographic methods. However the situation is quite different from the classical tomographic problem. Here a lot of apriori information is present regarding the p0- sitions of the bits of information profile representing single bit and a mode of operation (binary or n-ary). 2. ALGORITHMS FOR THE READOUT OF THE TOMOGRAPHIC MEMORIES Apriori information enables efficient reconstruction of the memory contents. In this paper a few methods for the information readout together with the simulation results will be presented. Special attention will be given to the noise considerations. Two different

Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

PubMed

Miho, Otoaki; Sato, Toru; Matsukubo, Takashi

2015-01-01

The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

Serial volumetric registration of pulmonary CT studies

NASA Astrophysics Data System (ADS)

Silva, José Silvestre; Silva, Augusto; Sousa Santos, Beatriz

2008-03-01

Detailed morphological analysis of pulmonary structures and tissue, provided by modern CT scanners, is of utmost importance as in the case of oncological applications both for diagnosis, treatment, and follow-up. In this case, a patient may go through several tomographic studies throughout a period of time originating volumetric sets of image data that must be appropriately registered in order to track suspicious radiological findings. The structures or regions of interest may change their position or shape in CT exams acquired at different moments, due to postural, physiologic or pathologic changes, so, the exams should be registered before any follow-up information can be extracted. Postural mismatching throughout time is practically impossible to avoid being particularly evident when imaging is performed at the limiting spatial resolution. In this paper, we propose a method for intra-patient registration of pulmonary CT studies, to assist in the management of the oncological pathology. Our method takes advantage of prior segmentation work. In the first step, the pulmonary segmentation is performed where trachea and main bronchi are identified. Then, the registration method proceeds with a longitudinal alignment based on morphological features of the lungs, such as the position of the carina, the pulmonary areas, the centers of mass and the pulmonary trans-axial principal axis. The final step corresponds to the trans-axial registration of the corresponding pulmonary masked regions. This is accomplished by a pairwise sectional registration process driven by an iterative search of the affine transformation parameters leading to optimal similarity metrics. Results with several cases of intra-patient, intra-modality registration, up to 7 time points, show that this method provides accurate registration which is needed for quantitative tracking of lesions and the development of image fusion strategies that may effectively assist the follow-up process.

Three-Dimensional Variation of the Slab Geometry Along Strike and Along Dip in the Cascadia Subduction

NASA Astrophysics Data System (ADS)

Gao, H.

2017-12-01

The crust and upper mantle seismic structure, spanning from the Juan de Fuca and Gorda spreading centers to the Cascade arc, is imaged with full-wave propagation simulation and ambient noise tomography. To retrieve Rayleigh-wave Empirical Green's Functions between station pairs, we process the vertical component of continuous seismic data recorded between 2004 and 2015 by about 800 stations, including three offshore seismic networks (the Cascadia Initiative Amphibious Array, the Blanco Transform OBS experiment, and the Gorda Deformation Zone OBS experiment) and all available broadband inland stations. The spreading centers have anomalously low shear-wave velocity beneath the oceanic lithosphere. Around the Cobb axial seamount, we observe a low velocity anomaly underlying a relatively thin oceanic lithosphere, indicating its influence on the Juan de Fuca ridge. The tomographic imaging reveals great details of the seismic feature of the oceanic lithosphere prior to and after subduction, which varies significantly along strike and along dip. On average, the thickness of the oceanic lithosphere is about 30-45 km. The Juan de Fuca lithosphere appears to be relatively thin around the ridge, especially beneath the Cobb axial seamount, and then gradually thickens with increasing distance from the ridge. The thickness of the Gorda plate appears to be constant, which is probably due to the small size of the subduction system from formation to subduction. It is noteworthy that the oceanic plate is imaged relatively weaker beneath the trench compared to other parts of the plate. We suggest that in addition to the possible hydration of the oceanic mantle lithosphere, other mechanisms must be considered to explain the observed seismic feature around the trench. Further landward, very low velocity anomalies are observed above the plate interface along the Cascade forearc, indicative of subducted sediments.

Three-Dimensional Eyeball and Orbit Volume Modification After LeFort III Midface Distraction.

PubMed

Smektala, Tomasz; Nysjö, Johan; Thor, Andreas; Homik, Aleksandra; Sporniak-Tutak, Katarzyna; Safranow, Krzysztof; Dowgierd, Krzysztof; Olszewski, Raphael

2015-07-01

The aim of our study was to evaluate orbital volume modification with LeFort III midface distraction in patients with craniosynostosis and its influence on eyeball volume and axial diameter modification. Orbital volume was assessed by the semiautomatic segmentation method based on deformable surface models and on 3-dimensional (3D) interaction with haptics. The eyeball volumes and diameters were automatically calculated after manual segmentation of computed tomographic scans with 3D slicer software. The mean, minimal, and maximal differences as well as the standard deviation and intraclass correlation coefficient (ICC) for intraobserver and interobserver measurements reliability were calculated. The Wilcoxon signed rank test was used to compare measured values before and after surgery. P < 0.05 was considered statistically significant. Intraobserver and interobserver ICC for haptic-aided semiautomatic orbital volume measurements were 0.98 and 0.99, respectively. The intraobserver and interobserver ICC values for manual segmentation of the eyeball volume were 0.87 and 0.86, respectively. The orbital volume increased significantly after surgery: 30.32% (mean, 5.96  mL) for the left orbit and 31.04% (mean, 6.31  mL) for the right orbit. The mean increase in eyeball volume was 12.3%. The mean increases in the eyeball axial dimensions were 7.3%, 9.3%, and 4.4% for the X-, Y-, and Z-axes, respectively. The Wilcoxon signed rank test showed that preoperative and postoperative eyeball volumes, as well as the diameters along the X- and Y-axes, were statistically significant. Midface distraction in patients with syndromic craniostenosis results in a significant increase (P < 0.05) in the orbit and eyeball volumes. The 2 methods (haptic-aided semiautomatic segmentation and manual 3D slicer segmentation) are reproducible techniques for orbit and eyeball volume measurements.

Morphea "en coup de sabre": An unusual oral presentation.

PubMed

Niklander, Sven; Marín, Constanza; Martínez, René; Esguep, Alfredo

2017-02-01

Morphea, or localized scleroderma, is an inflammatory disease that leads to sclerosis of the skin and underlying tissues due to excessive collagen deposition. Oral involvement is unusual and it may produce white linear fibrotic areas with a scar-like appearance, atrophy of tongue papillae, gingival recession and alveolar bone resorption. We report a case of a 13-year-old girl who consulted for progressive recession on the attached gingiva of her upper left incisors. She also presented a hypopigmented line on the left side skin of her upper lip, which continued through the vermilion and the lip mucosa, including the gingiva of the affected teeth. Clinical examination, blood tests, computerized axial tomography, echo-Doppler ultrasound and histopathological evaluation confirmed the diagnosis of morphea. Treatment with methotrexate and systemic corticosteroids was conducted. After 24 months, no other lesions appeared. No adverse side effects have been reported so far. Key words: Localized scleroderma, oral morphea, linear scleroderma, oral involvement, intraoral lesions.

Quality inspection of anisotropic scintillating lead tungstate (PbWO 4) crystals through measurement of interferometric fringe pattern parameters

NASA Astrophysics Data System (ADS)

Cocozzella, N.; Lebeau, M.; Majni, G.; Paone, N.; Rinaldi, D.

2001-08-01

Scintillating crystals are widely used as detectors in radiographic systems, computerized axial tomography devices and in calorimeters employed in high-energy physics. This paper results from a project motivated by the development of the CMS calorimeter at CERN, which will make use of a large number of scintillating crystals. In order to prevent crystals from breaking because of internal residual stress, a quality control system based on optic inspection of interference fringe patterns was developed. The principle of measurement procedures was theoretically modelled, and then a dedicated polariscope was designed and built, in order to observe the crystals under induced stresses or to evaluate the residual internal stresses. The results are innovative and open a new perspective for scintillating crystals quality control: the photoelastic constant normal to the optic axis of the lead tungstate crystals (PbWO 4) was measured, and the inspection procedure developed is applicable to mass production, not only to optimize the crystal processing, but also to establish a quality inspection procedure.

[X-ray computed tomographic abnormalities in schizophrenia. Trial of relationship with clinical data].

PubMed

D'Amato, T; Rochet, T; Dalery, J; Chauchat, J H; Terra, J L; Arteaga, C; Marie-Cardine, M

1992-01-01

Computerized tomography (CT-scan) studies in schizophrenia revealed that some patients have neuromorphological abnormalities. The structural changes consist mainly in lateral and third ventricle enlargement, and in cortical atrophy. The present study evaluates these three changes in 42 schizophrenics aged 18 to 50, compared to 24 healthy controls. Diagnosis were established from information gathered by personal interview with the SADS-LA. Clinical sub-types were evaluated according to the DSM III-R criteria. Moreover, detailed symptoms were rated according to the Positive And Negative Syndrome Scale (PANSS). CT scans were recorded in floppy disks and blindly analyzed. Schizophrenics shown significant higher mean size of lateral and third ventricles, and higher mean anterior cortical atrophy than healthy subjects. Significant differences were also found between subtypes, with more marked abnormalities in the disorganized group. The relationship between brain abnormalities and clinical symptoms recorded with the PANSS, were analysed using Pearson correlates. Positive correlations concerned mainly negative symptoms like blunted affect, emotional withdrawal, difficulties in abstract thinking, passive apathetic social withdrawal and lack of spontaneity of conversation. Positive correlations are also observed with some symptoms classified with the PANSS in the General Psychopathology scale such as mannerism and disorientation. Negative correlation concerned most of PANSS positive symptoms.

Pseudo-shading technique in the two-dimensional domain: a post-processing algorithm for enhancing the Z-buffer of a three-dimensional binary image.

PubMed

Tan, A C; Richards, R

1989-01-01

Three-dimensional (3D) medical graphics is becoming popular in clinical use on tomographic scanners. Research work in 3D reconstructive display of computerized tomography (CT) and magnetic resonance imaging (MRI) scans on conventional computers has produced many so-called pseudo-3D images. The quality of these images depends on the rendering algorithm, the coarseness of the digitized object, the number of grey levels and the image screen resolution. CT and MRI data are fundamentally voxel based and they produce images that are coarse because of the resolution of the data acquisition system. 3D images produced by the Z-buffer depth shading technique suffer loss of detail when complex objects with fine textural detail need to be displayed. Attempts have been made to improve the display of voxel objects, and existing techniques have shown the improvement possible using these post-processing algorithms. The improved rendering technique works on the Z-buffer image to generate a shaded image using a single light source in any direction. The effectiveness of the technique in generating a shaded image has been shown to be a useful means of presenting 3D information for clinical use.

Electrical properties of rat muscle after sciatic nerve injury: Impact on surface impedance measurements assessed via finite element analysis

NASA Astrophysics Data System (ADS)

Ahad, M. A.; Rutkove, S. B.

2010-04-01

Tetrapolar surface electrical impedance methods are sensitive to changes in muscle status and can therefore provide a means for studying neuromuscular disease noninvasively. In order to better understand the relationship between surface impedance measurements and the actual muscle electrical properties, we performed measurements on 20 adult Wistar rats, 8 of which underwent sciatic nerve crush. Surface impedance measurements were performed on the left hind limb both before injury and out to 2 weeks after injury. In addition, both normal and sciatic crush animals were sacrificed and the dielectric properties of the extracted gastrocnemius muscle measured. We found that 50 kHz conductivities were greater in the animals that underwent crush than in the animals that did not. The permittivities in both directions, however, showed non-significant differences. In order to analyze the effect of these changes as well as the accompanying reduction in muscle volume, a finite element model of the hind limb was developed based on computerized tomographic imaging. The model successfully predicted the surface impedance values in the animals after crush injury and, by its inverse application, may be used to help determine the underlying electrical properties of muscle in various neuromuscular diseases based on surface impedance data.

CT colonography with reduced bowel preparation after incomplete colonoscopy in the elderly.

PubMed

Iafrate, F; Hassan, C; Zullo, A; Stagnitti, A; Ferrari, R; Spagnuolo, A; Laghi, A

2008-07-01

We prospectively assessed the feasibility and acceptance of computerized tomographic colonography (CTC) without bowel cathartic preparation in elderly patients after incomplete colonoscopy. A total of 136 patients underwent CTC without cathartic preparation. The time delay between conventional colonoscopy and CTC ranged between 3 and 20 days, depending on the clinical situation. Before CTC, fecal tagging was achieved by adding diatrizoate meglumine and diatrizoate sodium to regular meals. CTCs were interpreted using a primary two-dimensional (2D) approach and 3D images for further characterization. Patients were interviewed before and 2 weeks after CTC to assess preparation acceptance. CTC was feasible and technically successful in all the 136 patients. Fecal tagging was judged as excellent in 113 (83%) patients and sufficient in 23 (17%). Average CT image interpretation time was 14.8 min. Six (4.4%) cases of colorectal cancer and nine (6.6%) large polyps were detected, as well as 23 (11.3%) extracolonic findings of high clinical importance. No major side effect occurred, although 25% patients reported minor side effects, especially diarrhea. Overall, 76/98 patients replied that they would be willing to repeat the test if necessary. CTC without cathartic preparation is a technically feasible and safe procedure to complete a colonic study in the elderly, prompting its use in clinical practice.

Finite element method framework for RF-based through-the-wall mapping

NASA Astrophysics Data System (ADS)

Campos, Rafael Saraiva; Lovisolo, Lisandro; de Campos, Marcello Luiz R.

2017-05-01

Radiofrequency (RF) Through-the-Wall Mapping (TWM) employs techniques originally applied in X-Ray Computerized Tomographic Imaging to map obstacles behind walls. It aims to provide valuable information for rescuing efforts in damaged buildings, as well as for military operations in urban scenarios. This work defines a Finite Element Method (FEM) based framework to allow fast and accurate simulations of the reconstruction of floors blueprints, using Ultra High-Frequency (UHF) signals at three different frequencies (500 MHz, 1 GHz and 2 GHz). To the best of our knowledge, this is the first use of FEM in a TWM scenario. This framework allows quick evaluation of different algorithms without the need to assemble a full test setup, which might not be available due to budgetary and time constraints. Using this, the present work evaluates a collection of reconstruction methods (Filtered Backprojection Reconstruction, Direct Fourier Reconstruction, Algebraic Reconstruction and Simultaneous Iterative Reconstruction) under a parallel-beam acquisition geometry for different spatial sampling rates, number of projections, antenna gains and operational frequencies. The use of multiple frequencies assesses the trade-off between higher resolution at shorter wavelengths and lower through-the-wall penetration. Considering all the drawbacks associated with such a complex problem, a robust and reliable computational setup based on a flexible method such as FEM can be very useful.

Comparison study on the feasibility of photoacoustic power spectrum analysis in osteoporosis detection

NASA Astrophysics Data System (ADS)

He, Weizhen; Zhu, Yunhao; Feng, Ting; Wang, Huaideng; Yuan, Jie; Xu, Guan; Wang, Xueding; Carson, Paul

2017-03-01

Osteoporosis is a progressive bone disease which is characterized by a decrease in the bone mass and deterioration in bone micro-architecture. In theory, photoacoustic (PA) imaging analysis has potential to obtain the characteristics of the bone effectively. Previous study demonstrated that photoacoustic spectral analysis (PASA) method with the qualified parameter slope could provide an objective assessment of bone microstructure and deterioration. In this study, we tried to compare PASA method with the traditional quantitative ultrasound (QUS) method in osteoporosis assessment. Numerical simulations of both PA and ultrasound (US) signal are performed on computerized tomographic (CT) images of trabecular bone with different bone mineral densities (BMDs). Ex vivo experiments were conducted on porcine femur bone model of different BMDs. We compared the quantified parameter slope and the broadband ultrasound attenuation (BUA) coefficient from the PASA and QUS among different bone models, respectively. Both the simulation and ex vivo experiment results show that bone with low BMD has a higher slope value and lower BUA value. Our result demonstrated that the PASA method has the same efficacy with QUS in bone assessment, considering PA is a non-ionizing, non-invasive technique, PASA method holds potential for clinical diagnosis in osteoporosis and other bone diseases.

Creation of virtual patients from CT images of cadavers to enhance integration of clinical and basic science student learning in anatomy.

PubMed

Jacobson, Stanley; Epstein, Scott K; Albright, Susan; Ochieng, Joseph; Griffiths, Jeffrey; Coppersmith, Veronica; Polak, Joseph F

2009-08-01

The goal of this study was to determine whether computerized tomographic (CT) images of cadavers could be used in addition to images from patients to develop virtual patients (VPs) to enhance integrated learning of basic and clinical science. We imaged 13 cadavers on a Siemens CT system. The DICOM images from the CT were noted to be of high quality by a radiologist who systematically identified all abnormal and pathological findings. The pathological findings from the CT images and the cause of death were used to develop plausible clinical cases and study questions. Each case was designed to highlight and explain the abnormal anatomic findings encountered during the cadaveric dissection. A 3D reconstruction was produced using OsiriX and then formatted into a QuickTime movie which was then stored on the Tufts University Sciences Knowledgebase (TUSK) as a VP. We conclude that CT scanning of cadavers produces high-quality images that can be used to develop VPs. Although the use of the VPs was optional and fewer than half of the students had an imaged cadaver for dissection, 59 of the 172 (34%) students accessed and reviewed the cases and images positively and were very encouraging for us to continue.

New developments in multimodal clinical multiphoton tomography

NASA Astrophysics Data System (ADS)

König, Karsten

2011-03-01

80 years ago, the PhD student Maria Goeppert predicted in her thesis in Goettingen, Germany, two-photon effects. It took 30 years to prove her theory, and another three decades to realize the first two-photon microscope. With the beginning of this millennium, first clinical multiphoton tomographs started operation in research institutions, hospitals, and in the cosmetic industry. The multiphoton tomograph MPTflexTM with its miniaturized flexible scan head became the Prism-Award 2010 winner in the category Life Sciences. Multiphoton tomographs with its superior submicron spatial resolution can be upgraded to 5D imaging tools by adding spectral time-correlated single photon counting units. Furthermore, multimodal hybrid tomographs provide chemical fingerprinting and fast wide-field imaging. The world's first clinical CARS studies have been performed with a hybrid multimodal multiphoton tomograph in spring 2010. In particular, nonfluorescent lipids and water as well as mitochondrial fluorescent NAD(P)H, fluorescent elastin, keratin, and melanin as well as SHG-active collagen have been imaged in patients with dermatological disorders. Further multimodal approaches include the combination of multiphoton tomographs with low-resolution imaging tools such as ultrasound, optoacoustic, OCT, and dermoscopy systems. Multiphoton tomographs are currently employed in Australia, Japan, the US, and in several European countries for early diagnosis of skin cancer (malignant melanoma), optimization of treatment strategies (wound healing, dermatitis), and cosmetic research including long-term biosafety tests of ZnO sunscreen nanoparticles and the measurement of the stimulated biosynthesis of collagen by anti-ageing products.

Chamber dimensions and functional assessment with coronary computed tomographic angiography as compared to echocardiography using American Society of Echocardiography guidelines

PubMed Central

Rose, Michael; Rubal, Bernard; Hulten, Edward; Slim, Jennifer N; Steel, Kevin; Furgerson, James L; Villines, Todd C

2014-01-01

Background: The correlation between normal cardiac chamber linear dimensions measured during retrospective coronary computed tomographic angiography as compared to transthoracic echocardiography using the American Society of Echocardiography guidelines is not well established. Methods: We performed a review from January 2005 to July 2011 to identify subjects with retrospective electrocardiogram-gated coronary computed tomographic angiography scans for chest pain and transthoracic echocardiography with normal cardiac structures performed within 90 days. Dimensions were manually calculated in both imaging modalities in accordance with the American Society of Echocardiography published guidelines. Left ventricular ejection fraction was calculated on echocardiography manually using the Simpson’s formula and by coronary computed tomographic angiography using the end-systolic and end-diastolic volumes. Results: We reviewed 532 studies, rejected 412 and had 120 cases for review with a median time between studies of 7 days (interquartile range (IQR25,75) = 0–22 days) with no correlation between the measurements made by coronary computed tomographic angiography and transthoracic echocardiography using Bland–Altman analysis. We generated coronary computed tomographic angiography cardiac dimension reference ranges for both genders for our population. Conclusion: Our findings represent a step towards generating cardiac chamber dimensions’ reference ranges for coronary computed tomographic angiography as compared to transthoracic echocardiography in patients with normal cardiac morphology and function using the American Society of Echocardiography guideline measurements that are commonly used by cardiologists. PMID:26770706

Detailed seismic velocity structure of the ultra-slow spread crust at the Mid-Cayman Spreading Center from travel-time tomography and synthetic seismograms

NASA Astrophysics Data System (ADS)

Harding, J.; Van Avendonk, H. J.; Hayman, N. W.; Grevemeyer, I.; Peirce, C.

2017-12-01

The Mid-Cayman Spreading Center (MCSC), an ultraslow-spreading center in the Caribbean Sea, has formed highly variable oceanic crust. Seafloor dredges have recovered extrusive basalts in the axial deeps as well as gabbro on bathymetric highs and exhumed mantle peridotite along the only 110 km MCSC. Wide-angle refraction data were collected with active-source ocean bottom seismometers in April, 2015, along lines parallel and across the MCSC. Travel-time tomography produces relatively smooth 2-D tomographic models of compressional wave velocity. These velocity models reveal large along- and across-axis variations in seismic velocity, indicating possible changes in crustal thickness, composition, faulting, and magmatism. It is difficult, however, to differentiate between competing interpretations of seismic velocity using these tomographic models alone. For example, in some areas the seismic velocities may be explained by either thin igneous crust or exhumed, serpentinized mantle. Distinguishing between these two interpretations is important as we explore the relationships between magmatism, faulting, and hydrothermal venting at ultraslow-spreading centers. We therefore improved our constraints on the shallow seismic velocity structure of the MCSC by modeling the amplitude of seismic refractions in the wide-angle data set. Synthetic seismograms were calculated with a finite-difference method for a range of models with different vertical velocity gradients. Small-scale features in the velocity models, such as steep velocity gradients and Moho boundaries, were explored systematically to best fit the real data. With this approach, we have improved our understanding of the compressional velocity structure of the MCSC along with the geological interpretations that are consistent with three seismic refraction profiles. Line P01 shows a variation in the thinness of lower seismic velocities along the axis, indicating two segment centers, while across-axis lines P02 and P03 show variations in igneous crustal thickness and exhumed mantle in some areas.

Influence of Intracanal Materials in Vertical Root Fracture Pathway Detection with Cone-beam Computed Tomography.

PubMed

Dutra, Kamile Leonardi; Pachêco-Pereira, Camila; Bortoluzzi, Eduardo Antunes; Flores-Mir, Carlos; Lagravère, Manuel O; Corrêa, Márcio

2017-07-01

Investigating the vertical root fracture (VRF) pathway under different clinical scenarios may help to diagnose this condition properly. We aimed to determine the capability and intrareliability of VRF pathway detection through cone-beam computed tomographic (CBCT) imaging as well as analyze the influence of different intracanal and crown materials. VRFs were mechanically induced in 30 teeth, and 4 clinical situations were reproduced in vitro: no filling, gutta-percha, post, and metal crown. A Prexion (San Mateo, CA) 3-dimensional tomographic device was used to generate 104 CBCT scans. The VRF pathway was determined by using landmarks in the Avizo software (Version 8.1; FEI Visualization Sciences Group, Burlington, MA) by 1 observer repeated 3 times. Analysis of variance and post hoc tests were applied to compare groups. Intrareliability demonstrated an excellent agreement (intraclass correlation coefficient mean = 0.93). Descriptive analysis showed that the fracture line measurement was smaller in the post and metal crown groups than in the no-filling and gutta-percha groups. The 1-way analysis of variance test found statistically significant differences among the groups measurements. The Bonferroni correction showed statistically significant differences related to the no-filling and gutta-percha groups versus the post and metal crown groups. The VRF pathway can be accurately detected in a nonfilled tooth using limited field of view CBCT imaging. The presence of gutta-percha generated a low beam hardening artifact that did not hinder the VRF extent. The presence of an intracanal gold post made the fracture line appear smaller than it really was in the sagittal images; in the axial images, a VRF was only detected when the apical third was involved. The presence of a metal crown did not generate additional artifacts on the root surface compared to the intracanal gold post by itself. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

First results from the ionospheric tomography experiment using beacon TEC data obtained by means of a network along a longitude of 136°E over Japan

NASA Astrophysics Data System (ADS)

Thampi, Smitha V.; Yamamoto, Mamoru

2010-03-01

A chain of newly designed GNU (GNU is not UNIX) Radio Beacon Receivers (GRBR) has recently been established over Japan, primarily for tomographic imaging of the ionosphere over this region. Receivers installed at Shionomisaki (33.45°N, 135.8°E), Shigaraki (34.8°N, 136.1°E), and Fukui (36°N, 136°E) continuously track low earth orbiting satellites (LEOS), mainly OSCAR, Cosmos, and FORMOSAT-3/COSMIC, to obtain simultaneous total electron content (TEC) data from these three locations, which are then used for the tomographic reconstruction of ionospheric electron densities. This is the first GRBR network established for TEC observations, and the first beacon-based tomographic imaging in Japanese longitudes. The first tomographic images revealed the temporal evolution with all of the major features in the ionospheric electron density distribution over Japan. A comparison of the tomographically reconstructed electron densities with the ƒ o F 2 data from Kokubunji (35°N, 139°E) revealed that there was good agreement between the datasets. These first results show the potential of GRBR and its network for making continuous, unattended ionospheric TEC measurements and for tomographic imaging of the ionosphere.

On the feasibility of tomographic-PIV with low pulse energy illumination in a lifted turbulent jet flame

NASA Astrophysics Data System (ADS)

Boxx, I.; Carter, C. D.; Meier, W.

2014-08-01

Tomographic particle image velocimetry (tomographic-PIV) is a recently developed measurement technique used to acquire volumetric velocity field data in liquid and gaseous flows. The technique relies on line-of-sight reconstruction of the rays between a 3D particle distribution and a multi-camera imaging system. In a turbulent flame, however, index-of-refraction variations resulting from local heat-release may inhibit reconstruction and thereby render the technique infeasible. The objective of this study was to test the efficacy of tomographic-PIV in a turbulent flame. An additional goal was to determine the feasibility of acquiring usable tomographic-PIV measurements in a turbulent flame at multi-kHz acquisition rates with current-generation laser and camera technology. To this end, a setup consisting of four complementary metal oxide semiconductor cameras and a dual-cavity Nd:YAG laser was implemented to test the technique in a lifted turbulent jet flame. While the cameras were capable of kHz-rate image acquisition, the laser operated at a pulse repetition rate of only 10 Hz. However, use of this laser allowed exploration of the required pulse energy and thus power for a kHz-rate system. The imaged region was 29 × 28 × 2.7 mm in size. The tomographic reconstruction of the 3D particle distributions was accomplished using the multiplicative algebraic reconstruction technique. The results indicate that volumetric velocimetry via tomographic-PIV is feasible with pulse energies of 25 mJ, which is within the capability of current-generation kHz-rate diode-pumped solid-state lasers.

Large-scale tomographic particle image velocimetry using helium-filled soap bubbles

NASA Astrophysics Data System (ADS)

Kühn, Matthias; Ehrenfried, Klaus; Bosbach, Johannes; Wagner, Claus

2011-04-01

To measure large-scale flow structures in air, a tomographic particle image velocimetry (tomographic PIV) system for measurement volumes of the order of one cubic metre is developed, which employs helium-filled soap bubbles (HFSBs) as tracer particles. The technique has several specific characteristics compared to most conventional tomographic PIV systems, which are usually applied to small measurement volumes. One of them is spot lights on the HFSB tracers, which slightly change their position, when the direction of observation is altered. Further issues are the large particle to voxel ratio and the short focal length of the used camera lenses, which result in a noticeable variation of the magnification factor in volume depth direction. Taking the specific characteristics of the HFSBs into account, the feasibility of our large-scale tomographic PIV system is demonstrated by showing that the calibration errors can be reduced down to 0.1 pixels as required. Further, an accurate and fast implementation of the multiplicative algebraic reconstruction technique, which calculates the weighting coefficients when needed instead of storing them, is discussed. The tomographic PIV system is applied to measure forced convection in a convection cell at a Reynolds number of 530 based on the inlet channel height and the mean inlet velocity. The size of the measurement volume and the interrogation volumes amount to 750 mm × 450 mm × 165 mm and 48 mm × 48 mm × 24 mm, respectively. Validation of the tomographic PIV technique employing HFSBs is further provided by comparing profiles of the mean velocity and of the root mean square velocity fluctuations to respective planar PIV data.

11 CFR 9033.12 - Production of computerized information.

Code of Federal Regulations, 2011 CFR

2011-01-01

... magnetic media, such as magnetic tapes or magnetic diskettes, containing the computerized information at.... The computerized magnetic media shall be prepared and delivered at the committee's expense and shall... Commission's Computerized Magnetic Media Requirements for title 26 Candidates/Committees Receiving Federal...

SIRT-FILTER v1.0.0

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

PELT, DANIEL

2017-04-21

Small Python package to compute tomographic reconstructions using a reconstruction method published in: Pelt, D.M., & De Andrade, V. (2017). Improved tomographic reconstruction of large-scale real-world data by filter optimization. Advanced Structural and Chemical Imaging 2: 17; and Pelt, D. M., & Batenburg, K. J. (2015). Accurately approximating algebraic tomographic reconstruction by filtered backprojection. In Proceedings of The 13th International Meeting on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine (pp. 158-161).

Quantitation of mandibular ramus volume as a source of bone grafting.

PubMed

Verdugo, Fernando; Simonian, Krikor; Smith McDonald, Roberto; Nowzari, Hessam

2009-10-01

When alveolar atrophy impairs dental implant placement, ridge augmentation using mandibular ramus graft may be considered. In live patients, however, an accurate calculation of the amount of bone that can be safely harvested from the ramus has not been reported. The use of a software program to perform these calculations can aid in preventing surgical complications. The aim of the present study was to intra-surgically quantify the volume of the ramus bone graft that can be safely harvested in live patients, and compare it to presurgical computerized tomographic calculations. The AutoCAD software program quantified ramus bone graft in 40 consecutive patients from computerized tomographies. Direct intra-surgical measurements were recorded thereafter and compared to software data (n = 10). In these 10 patients, the bone volume was also measured at the recipient sites 6 months post-sinus augmentation. The mandibular second and third molar areas provided the thickest cortical graft averaging 2.8 +/- 0.6 mm. The thinnest bone was immediately posterior to the third molar (1.9 +/- 0.3 mm). The volume of ramus bone graft measured by AutoCAD averaged 0.8 mL (standard deviation [SD] 0.2 mL, range: 0.4-1.2 mL). The volume of bone graft measured intra-surgically averaged 2.5 mL (SD 0.4 mL, range: 1.8-3.0 mL). The difference between the two measurement methods was significant (p < 0.001). The bone volume measured 6 months post-sinus augmentation averaged 2.2 mL (SD 0.4 mL, range: 1.6-2.8 mL) with a mean loss of 0.3 mL in volume. The mandibular second molar area provided the thickest cortical graft. A cortical plate of 2.8 mm in average at combined second and third molar areas provided 2.5 mL particulated volume. The use of a design software program can improve surgical treatment planning prior to ramus bone grafting. The AutoCAD software program did not overestimate the volume of bone that can be safely harvested from the mandibular ramus.

Three-dimensional thoracic aorta principal strain analysis from routine ECG-gated computerized tomography: feasibility in patients undergoing transcatheter aortic valve replacement.

PubMed

Satriano, Alessandro; Guenther, Zachary; White, James A; Merchant, Naeem; Di Martino, Elena S; Al-Qoofi, Faisal; Lydell, Carmen P; Fine, Nowell M

2018-05-02

Functional impairment of the aorta is a recognized complication of aortic and aortic valve disease. Aortic strain measurement provides effective quantification of mechanical aortic function, and 3-dimenional (3D) approaches may be desirable for serial evaluation. Computerized tomographic angiography (CTA) is routinely performed for various clinical indications, and offers the unique potential to study 3D aortic deformation. We sought to investigate the feasibility of performing 3D aortic strain analysis in a candidate population of patients undergoing transcatheter aortic valve replacement (TAVR). Twenty-one patients with severe aortic valve stenosis (AS) referred for TAVR underwent ECG-gated CTA and echocardiography. CTA images were analyzed using a 3D feature-tracking based technique to construct a dynamic aortic mesh model to perform peak principal strain amplitude (PPSA) analysis. Segmental strain values were correlated against clinical, hemodynamic and echocardiographic variables. Reproducibility analysis was performed. The mean patient age was 81±6 years. Mean left ventricular ejection fraction was 52±14%, aortic valve area (AVA) 0.6±0.3 cm 2 and mean AS pressure gradient (MG) 44±11 mmHg. CTA-based 3D PPSA analysis was feasible in all subjects. Mean PPSA values for the global thoracic aorta, ascending aorta, aortic arch and descending aorta segments were 6.5±3.0, 10.2±6.0, 6.1±2.9 and 3.3±1.7%, respectively. 3D PSSA values demonstrated significantly more impairment with measures of worsening AS severity, including AVA and MG for the global thoracic aorta and ascending segment (p<0.001 for all). 3D PSSA was independently associated with AVA by multivariable modelling. Coefficients of variation for intra- and inter-observer variability were 5.8 and 7.2%, respectively. Three-dimensional aortic PPSA analysis is clinically feasible from routine ECG-gated CTA. Appropriate reductions in PSSA were identified with increasing AS hemodynamic severity. Expanded study of 3D aortic PSSA for patients with various forms of aortic disease is warranted.

A review of US anthropometric reference data (1971 2000) with comparisons to both stylized and tomographic anatomic models

NASA Astrophysics Data System (ADS)

Huh, C.; Bolch, W. E.

2003-10-01

Two classes of anatomic models currently exist for use in both radiation protection and radiation dose reconstruction: stylized mathematical models and tomographic voxel models. The former utilize 3D surface equations to represent internal organ structure and external body shape, while the latter are based on segmented CT or MR images of a single individual. While tomographic models are clearly more anthropomorphic than stylized models, a given model's characterization as being anthropometric is dependent upon the reference human to which the model is compared. In the present study, data on total body mass, standing/sitting heights and body mass index are collected and reviewed for the US population covering the time interval from 1971 to 2000. These same anthropometric parameters are then assembled for the ORNL series of stylized models, the GSF series of tomographic models (Golem, Helga, Donna, etc), the adult male Zubal tomographic model and the UF newborn tomographic model. The stylized ORNL models of the adult male and female are found to be fairly representative of present-day average US males and females, respectively, in terms of both standing and sitting heights for ages between 20 and 60-80 years. While the ORNL adult male model provides a reasonably close match to the total body mass of the average US 21-year-old male (within ~5%), present-day 40-year-old males have an average total body mass that is ~16% higher. For radiation protection purposes, the use of the larger 73.7 kg adult ORNL stylized hermaphrodite model provides a much closer representation of average present-day US females at ages ranging from 20 to 70 years. In terms of the adult tomographic models from the GSF series, only Donna (40-year-old F) closely matches her age-matched US counterpart in terms of average body mass. Regarding standing heights, the better matches to US age-correlated averages belong to Irene (32-year-old F) for the females and Golem (38-year-old M) for the males. Both Helga (27-year-old F) and Donna, however, provide good matches to average US sitting heights for adult females, while Golem and Otoko (male of unknown age) yield sitting heights that are slightly below US adult male averages. Finally, Helga is seen as the only GSF tomographic female model that yields a body mass index in line with her average US female counterpart at age 26. In terms of dose reconstruction activities, however, all current tomographic voxel models are valuable assets in attempting to cover the broad distribution of individual anthropometric parameters representative of the current US population. It is highly recommended that similar attempts to create a broad library of tomographic models be initiated in the United States and elsewhere to complement and extend the limited number of tomographic models presently available for these efforts.

Critical factors influencing physicians' intention to use computerized clinical practice guidelines: an integrative model of activity theory and the technology acceptance model.

PubMed

Hsiao, Ju-Ling; Chen, Rai-Fu

2016-01-16

With the widespread use of information communication technologies, computerized clinical practice guidelines are developed and considered as effective decision supporting tools in assisting the processes of clinical activities. However, the development of computerized clinical practice guidelines in Taiwan is still at the early stage and acceptance level among major users (physicians) of computerized clinical practice guidelines is not satisfactory. This study aims to investigate critical factors influencing physicians' intention to computerized clinical practice guideline use through an integrative model of activity theory and the technology acceptance model. The survey methodology was employed to collect data from physicians of the investigated hospitals that have implemented computerized clinical practice guidelines. A total of 505 questionnaires were sent out, with 238 completed copies returned, indicating a valid response rate of 47.1 %. The collected data was then analyzed by structural equation modeling technique. The results showed that attitudes toward using computerized clinical practice guidelines (γ = 0.451, p < 0.001), organizational support (γ = 0.285, p < 0.001), perceived usefulness of computerized clinical practice guidelines (γ = 0.219, p < 0.05), and social influence (γ = 0.213, p < 0.05) were critical factors influencing physicians' intention to use computerized clinical practice guidelines, and these factors can explain 68.6 % of the variance in intention to use computerized clinical practice guidelines. This study confirmed that some subject (human) factors, environment (organization) factors, tool (technology) factors mentioned in the activity theory should be carefully considered when introducing computerized clinical practice guidelines. Managers should pay much attention on those identified factors and provide adequate resources and incentives to help the promotion and use of computerized clinical practice guidelines. Through the appropriate use of computerized clinical practice guidelines, the clinical benefits, particularly in improving quality of care and facilitating the clinical processes, will be realized.

39 CFR 501.15 - Computerized Meter Resetting System.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.15 Computerized Meter Resetting System. (a) Description. The Computerized Meter Resetting System (CMRS) permits customers to reset their postage meters at... 39 Postal Service 1 2010-07-01 2010-07-01 false Computerized Meter Resetting System. 501.15...

A comparison of newborn stylized and tomographic models for dose assessment in paediatric radiology

NASA Astrophysics Data System (ADS)

Staton, R. J.; Pazik, F. D.; Nipper, J. C.; Williams, J. L.; Bolch, W. E.

2003-04-01

Establishment of organ doses from diagnostic and interventional examinations is a key component to quantifying the radiation risks from medical exposures and for formulating corresponding dose-reduction strategies. Radiation transport models of human anatomy provide a convenient method for simulating radiological examinations. At present, two classes of models exist: stylized mathematical models and tomographic voxel models. In the present study, organ dose comparisons are made for projection radiographs of both a stylized and a tomographic model of the newborn patient. Sixteen separate radiographs were simulated for each model at x-ray technique factors typical of newborn examinations: chest, abdomen, thorax and head views in the AP, PA, left LAT and right LAT projection orientation. For AP and PA radiographs of the torso (chest, abdomen and thorax views), the effective dose assessed for the tomographic model exceeds that for the stylized model with per cent differences ranging from 19% (AP abdominal view) to 43% AP chest view. In contrast, the effective dose for the stylized model exceeds that for the tomographic model for all eight lateral views including those of the head, with per cent differences ranging from 9% (LLAT chest view) to 51% (RLAT thorax view). While organ positioning differences do exist between the models, a major factor contributing to differences in effective dose is the models' exterior trunk shape. In the tomographic model, a more elliptical shape is seen thus providing for less tissue shielding for internal organs in the AP and PA directions, with corresponding increased tissue shielding in the lateral directions. This observation is opposite of that seen in comparisons of stylized and tomographic models of the adult.

High-Energy, High-Pulse-Rate Light Sources for Enhanced Time-Resolved Tomographic PIV of Unsteady and Turbulent Flows

DTIC Science & Technology

2017-07-31

Report: High-Energy, High-Pulse-Rate Light Sources for Enhanced Time -Resolved Tomographic PIV of Unsteady & Turbulent Flows The views, opinions and/or...reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching...High-Energy, High-Pulse-Rate Light Sources for Enhanced Time -Resolved Tomographic PIV of Unsteady & Turbulent Flows Report Term: 0-Other Email

21 CFR 884.2800 - Computerized Labor Monitoring System.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Computerized Labor Monitoring System. 884.2800... Devices § 884.2800 Computerized Labor Monitoring System. (a) Identification. A computerized labor monitoring system is a system intended to continuously measure cervical dilation and fetal head descent and...

Image processing pipeline for synchrotron-radiation-based tomographic microscopy.

PubMed

Hintermüller, C; Marone, F; Isenegger, A; Stampanoni, M

2010-07-01

With synchrotron-radiation-based tomographic microscopy, three-dimensional structures down to the micrometer level can be visualized. Tomographic data sets typically consist of 1000 to 1500 projections of 1024 x 1024 to 2048 x 2048 pixels and are acquired in 5-15 min. A processing pipeline has been developed to handle this large amount of data efficiently and to reconstruct the tomographic volume within a few minutes after the end of a scan. Just a few seconds after the raw data have been acquired, a selection of reconstructed slices is accessible through a web interface for preview and to fine tune the reconstruction parameters. The same interface allows initiation and control of the reconstruction process on the computer cluster. By integrating all programs and tools, required for tomographic reconstruction into the pipeline, the necessary user interaction is reduced to a minimum. The modularity of the pipeline allows functionality for new scan protocols to be added, such as an extended field of view, or new physical signals such as phase-contrast or dark-field imaging etc.

Tomographic imaging of OH laser-induced fluorescence in laminar and turbulent jet flames

NASA Astrophysics Data System (ADS)

Li, Tao; Pareja, Jhon; Fuest, Frederik; Schütte, Manuel; Zhou, Yihui; Dreizler, Andreas; Böhm, Benjamin

2018-01-01

In this paper a new approach for 3D flame structure diagnostics using tomographic laser-induced fluorescence (Tomo-LIF) of the OH radical was evaluated. The approach combined volumetric illumination with a multi-camera detection system of eight views. Single-shot measurements were performed in a methane/air premixed laminar flame and in a non-premixed turbulent methane jet flame. 3D OH fluorescence distributions in the flames were reconstructed using the simultaneous multiplicative algebraic reconstruction technique. The tomographic measurements were compared and validated against results of OH-PLIF in the laminar flame. The effects of the experimental setup of the detection system and the size of the volumetric illumination on the quality of the tomographic reconstructions were evaluated. Results revealed that the Tomo-LIF is suitable for volumetric reconstruction of flame structures with acceptable spatial resolution and uncertainty. It was found that the number of views and their angular orientation have a strong influence on the quality and accuracy of the tomographic reconstruction while the illumination volume thickness influences mainly the spatial resolution.

Seismic structure beneath Mt Vesuvius from receiver function analysis and local earthquakes tomography: evidences for location and geometry of the magma chamber

NASA Astrophysics Data System (ADS)

Agostinetti, N. Piana; Chiarabba, C.

2008-12-01

The recognition and localization of magmatic fluids are pre-requisites for evaluating the volcano hazard of the highly urbanized area of Mt Vesuvius. Here we show evidence and constraints for the volumetric estimation of magmatic fluids underneath this sleeping volcano. We use Receiver Functions for teleseismic data recorded at a temporary broad-band station installed on the volcano to constrain the S-wave velocity structure in the crust. Receiver Functions are analysed and inverted using the Neighbourhood Algorithm approach. The 1-D S-velocity profile is jointly interpreted and discussed with a new Vp and Vp/Vs image obtained by applying double difference tomographic techniques to local earthquakes. Seismologic data define the geometry of an axial, cylindrical high Vp, high Vs body consisting of a shallow solidified materials, probably the remnants of the caldera, and ultramafic rocks paving the crustal magma chamber. Between these two anomalies, we find a small region where the shear wave velocity drops, revealing the presence of magma at relatively shallow depths. The volume of fluids (30 km3) is sufficient to contribute future explosive eruptions.

Current research on ARO-positron emission tomography

NASA Astrophysics Data System (ADS)

Jan, Meei-Ling; Liang, Hsing C.; Huang, Shin W.; Shyu, Chuen-Shing; Tang, Jiy-Shan; Liu, Hong-Chih; Pei, Cheng-Chih; Yeh, Ching-Kai

2000-06-01

We are presently constructing `AROPET', a rotating PET scanner for imaging small animals. The design of the system has flexible geometry, using four detectors. Each detector is made of a position-sensitive PMTs (Hamamatsu R3941) coupled with 18 X 16 small individual BGO scintillator crystals of dimension 2.6 X 2.6 X 25 mm3. Animals can be imaged in two modes. One is similar to a gamma camera in which the detectors are stationary and a 2D planar projection imaging is obtained. This mode is used for initial characterization of the bio-distribution of tracers. In the other mode the detectors are rotated through 90 degree(s), and the diameter can be adjusted between 22 cm - 40 cm. This mode resembles a conventional 3D PET scan using a partial detector ring. Thirty-one tomographic images can be obtained after rebinning and reconstruction. The field of view is 51.3 mm (transaxial) by 45.6 mm (axial). The spatial resolution of the planar projection mode, and the results of the planar image of a phantom and the dynamical images of the bio-distribution of F18-FDG in a mouse are discussed.

Recurrent hemorrhage in hemangioblastoma involving the posterior fossa: Case report

PubMed Central

Marvin, Eric; Akhter, Asad S.; Coppens, Jeroen R.

2017-01-01

Background: Hemangioblastomas (HGBs) are the most common primary intra-axial posterior fossa tumor in adults. Although spontaneous hemorrhage of these tumors is exceedingly rare, despite their vascular nature, we describe a case of recurrent hemorrhage with associated tonsillar herniation, and demonstrate that a surgical approach can provide a suitable outcome. Case Description: A 54-year-old female with von Hippel-Lindau (VHL) syndrome presented with acute loss of consciousness and Glasgow Coma Scale (GCS) was 4. Computed tomographic (CT) images demonstrated large volume subarachnoid hemorrhage of the posterior fossa with intraventricular extension and intraparenchymal hemorrhage involving the right cerebellar tonsil. Magnetic resonance imaging (MRI) displayed three lesions in the posterior fossa, two near the hemorrhage site. Patient underwent suboccipital craniectomy with a decent recovery followed by radiosurgery as she refused resection. A second hemorrhage occurred ultimately prompting surgical resection of the three posterior fossa lesions, with a reasonable postoperative course. Conclusion: Hemorrhage of HGBs of the posterior fossa can present in conjunction of tonsillar herniation. Re-hemorrhage appears to be likely if prior acute hemorrhage has occurred. A stepwise approach of surgical decompression and resection may provide the best outcome. PMID:28713626

Hybrid Gama Emission Tomography (HGET): FY16 Annual Report

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

Miller, Erin A.; Smith, Leon E.; Wittman, Richard S.

2017-02-01

Current International Atomic Energy Agency (IAEA) methodologies for the verification of fresh low-enriched uranium (LEU) and mixed oxide (MOX) fuel assemblies are volume-averaging methods that lack sensitivity to individual pins. Further, as fresh fuel assemblies become more and more complex (e.g., heavy gadolinium loading, high degrees of axial and radial variation in fissile concentration), the accuracy of current IAEA instruments degrades and measurement time increases. Particularly in light of the fact that no special tooling is required to remove individual pins from modern fuel assemblies, the IAEA needs new capabilities for the verification of unirradiated (i.e., fresh LEU and MOX)more » assemblies to ensure that fissile material has not been diverted. Passive gamma emission tomography has demonstrated potential to provide pin-level verification of spent fuel, but gamma-ray emission rates from unirradiated fuel emissions are significantly lower, precluding purely passive tomography methods. The work presented here introduces the concept of Hybrid Gamma Emission Tomography (HGET) for verification of unirradiated fuels, in which a neutron source is used to actively interrogate the fuel assembly and the resulting gamma-ray emissions are imaged using tomographic methods to provide pin-level verification of fissile material concentration.« less

3D visualization of the scoliotic spine: longitudinal studies, data acquisition, and radiation dosage constraints

NASA Astrophysics Data System (ADS)

Kalvin, Alan D.; Adler, Roy L.; Margulies, Joseph Y.; Tresser, Charles P.; Wu, Chai W.

1999-05-01

Decision making in the treatment of scoliosis is typically based on longitudinal studies that involve the imaging and visualization the progressive degeneration of a patient's spine over a period of years. Some patients will need surgery if their spinal deformation exceeds a certain degree of severity. Currently, surgeons rely on 2D measurements, obtained from x-rays, to quantify spinal deformation. Clearly working only with 2D measurements seriously limits the surgeon's ability to infer 3D spinal pathology. Standard CT scanning is not a practical solution for obtaining 3D spinal measurements of scoliotic patients. Because it would expose the patient to a prohibitively high dose of radiation. We have developed 2 new CT-based methods of 3D spinal visualization that produce 3D models of the spine by integrating a very small number of axial CT slices with data obtained from CT scout data. In the first method the scout data are converted to sinogram data, and then processed by a tomographic image reconstruction algorithm. In the second method, the vertebral boundaries are detected in the scout data, and these edges are then used as linear constraints to determine 2D convex hulls of the vertebrae.

Optimal joule heating of the subsurface

DOEpatents

Berryman, James G.; Daily, William D.

1994-01-01

A method for simultaneously heating the subsurface and imaging the effects of the heating. This method combines the use of tomographic imaging (electrical resistance tomography or ERT) to image electrical resistivity distribution underground, with joule heating by electrical currents injected in the ground. A potential distribution is established on a series of buried electrodes resulting in energy deposition underground which is a function of the resistivity and injection current density. Measurement of the voltages and currents also permits a tomographic reconstruction of the resistivity distribution. Using this tomographic information, the current injection pattern on the driving electrodes can be adjusted to change the current density distribution and thus optimize the heating. As the heating changes conditions, the applied current pattern can be repeatedly adjusted (based on updated resistivity tomographs) to affect real time control of the heating.

45 CFR 307.15 - Approval of advance planning documents for computerized support enforcement systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... computerized support enforcement systems. 307.15 Section 307.15 Public Welfare Regulations Relating to Public... CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES COMPUTERIZED SUPPORT ENFORCEMENT SYSTEMS § 307.15 Approval of advance planning documents for computerized support enforcement systems. (a...

Arkansas' Curriculum Guide. Competency Based Computerized Accounting.

ERIC Educational Resources Information Center

Arkansas State Dept. of Education, Little Rock. Div. of Vocational, Technical and Adult Education.

This guide contains the essential parts of a total curriculum for a one-year secondary-level course in computerized accounting. Addressed in the individual sections of the guide are the following topics: the complete accounting cycle, computer operations for accounting, computerized accounting and general ledgers, computerized accounts payable,…

Axial crustal structure of the Costa Rica Rift: Implications for along-axis hydrothermal circulation

NASA Astrophysics Data System (ADS)

Zhang, L.; Tong, V.; Hobbs, R. W.; Peirce, C.; Lowell, R. P.; Haughton, G.; Murton, B. J.; Morales Maqueda, M. A.; Harris, R. N.; Robinson, A. H.

2017-12-01

In 2015, a multidisciplinary geophysical cruise surveyed the Costa Rica Rift (CRR) in the Panama Basin of the equatorial East Pacific, acquiring a grid of multichannel seismic and wide-angle profiles to determine the mode of oceanic crustal accretion at intermediate-spreading ridges, and how the crustal structure may be influenced by hydrothermal fluid flow. Analysis of 69,000 P-wave first arrivals recorded by 25 ocean-bottom seismographs deployed over a 20 × 20 km area that straddles the ridge axis, reveals a 3D velocity-depth model of upper crustal structure. In particular, the model shows a low velocity anomaly that extends to 2 km below seabed centred on a small-offset non-transform discontinuity (NTD), and a pattern of increasing velocity with distance off-axis that may reflect changes in porosity and permeability in layer 2 of the crust. Assuming the upper crustal velocity anomalies are linked with porosity and hence represent the ability of fluid to flow, comparison of the tomographic model with the volcanic seabed morphology suggests that the broad low velocity zone beneath the NTD may be a region of extensive fracturing. Hence, we infer that this region may provide a primary pathway for the recharge of seawater into the crust. Further west along the axis, beneath the bathymetric dome, which is the shallowest portion along the axis, the low-velocity anomaly is less pronounced, suggesting that fractures are less open and that fluid-rock interaction has encouraged mineral precipitation and alteration, as a result of a longer established hydrothermal fluid flow driven by the axial magma lens observed beneath it. This interpretation is supported by the presence of a plume from an active hydrothermal vent system. Hence, we infer that the variable velocity structure of the upper crust of the CRR is a proxy that reflects the primary porosity, faulting and fracturing related to phases of magma-driven accretion and/or ridge geometry re-adjustment, and that there is along-axis hydrothermal circulation transferring heat and impacting the properties of newly accreted oceanic crust. This research is part of a major, interdisciplinary NERC-funded collaboration entitled: Oceanographic and Seismic Characterisation of heat dissipation and alteration by hydrothermal fluids at an Axial Ridge (OSCAR).

Tomographic imaging of subducted lithosphere below northwest Pacific island arcs

USGS Publications Warehouse

Van Der Hilst, R.; Engdahl, R.; Spakman, W.; Nolet, G.

1991-01-01

The seismic tomography problem does not have a unique solution, and published tomographic images have been equivocal with regard to the deep structure of subducting slabs. An improved tomographic method, using a more realistic background Earth model and surf ace-reflected as well as direct seismic phases, shows that slabs beneath the Japan and Izu Bonin island arcs are deflected at the boundary between upper and lower mantle, whereas those beneath the northern Kuril and Mariana arcs sink into the lower mantle.

Business aspects of cardiovascular computed tomography: tackling the challenges.

PubMed

Bateman, Timothy M

2008-01-01

The purpose of this article is to provide a comprehensive understanding of the business issues surrounding provision of dedicated cardiovascular computed tomographic imaging. Some of the challenges include high up-front costs, current low utilization relative to scanner capability, and inadequate payments. Cardiovascular computed tomographic imaging is a valuable clinical modality that should be offered by cardiovascular centers-of-excellence. With careful consideration of the business aspects, moderate-to-large size cardiology programs should be able to implement an economically viable cardiovascular computed tomographic service.

3D "spectracoustic" system: a modular, tomographic, spectroscopic mapping imaging, non-invasive, diagnostic system for detection of small starting developing tumors like melanoma

NASA Astrophysics Data System (ADS)

Karagiannis, Georgios

2017-03-01

This work led to a new method named 3D spectracoustic tomographic mapping imaging. The current and the future work is related to the fabrication of a combined acoustic microscopy transducer and infrared illumination probe permitting the simultaneous acquisition of the spectroscopic and the tomographic information. This probe provides with the capability of high fidelity and precision registered information from the combined modalities named spectracoustic information.

Single-Shot, Volumetrically Illuminated, Three-Dimensional, Tomographic Laser-Induced-Fluorescence Imaging in a Gaseous Free Jet

DTIC Science & Technology

2016-04-28

Single- shot , volumetrically illuminated, three- dimensional, tomographic laser-induced- fluorescence imaging in a gaseous free jet Benjamin R. Halls...us.af.mil Abstract: Single- shot , tomographic imaging of the three-dimensional concentration field is demonstrated in a turbulent gaseous free jet in co-flow...2001). 6. K. M. Tacina and W. J. A. Dahm, “Effects of heat release on turbulent shear flows, Part 1. A general equivalence principle for non-buoyant

Tomographic diffractive microscopy with agile illuminations for imaging targets in a noisy background.

PubMed

Zhang, T; Godavarthi, C; Chaumet, P C; Maire, G; Giovannini, H; Talneau, A; Prada, C; Sentenac, A; Belkebir, K

2015-02-15

Tomographic diffractive microscopy is a marker-free optical digital imaging technique in which three-dimensional samples are reconstructed from a set of holograms recorded under different angles of incidence. We show experimentally that, by processing the holograms with singular value decomposition, it is possible to image objects in a noisy background that are invisible with classical wide-field microscopy and conventional tomographic reconstruction procedure. The targets can be further characterized with a selective quantitative inversion.

Computerized Adaptive Personality Testing: A Review and Illustration With the MMPI-2 Computerized Adaptive Version.

ERIC Educational Resources Information Center

Forbey, Johnathan D.; Ben-Porath, Yossef S.

2007-01-01

Computerized adaptive testing in personality assessment can improve efficiency by significantly reducing the number of items administered to answer an assessment question. Two approaches have been explored for adaptive testing in computerized personality assessment: item response theory and the countdown method. In this article, the authors…

A Randomized Controlled Trial of the "Cool Teens" CD-ROM Computerized Program for Adolescent Anxiety

ERIC Educational Resources Information Center

Wuthrich, Viviana M.; Rapee, Ronald M.; Cunningham, Michael J.; Lyneham, Heidi J.; Hudson, Jennifer L.; Schniering, Carolyn A.

2012-01-01

Objective: Computerized cognitive behavioral interventions for anxiety disorders in adults have been shown to be efficacious, but limited data are available on the use of computerized interventions with young persons. Adolescents in particular are difficult to engage in treatment and may be especially suited to computerized technologies. This…

Combining computerized social cognitive training with neuroplasticity-based auditory training in schizophrenia.

PubMed

Sacks, Stephanie; Fisher, Melissa; Garrett, Coleman; Alexander, Phillip; Holland, Christine; Rose, Demian; Hooker, Christine; Vinogradov, Sophia

2013-01-01

Social cognitive deficits are an important treatment target in schizophrenia, but it is unclear to what degree they require specialized interventions and which specific components of behavioral interventions are effective. In this pilot study, we explored the effects of a novel computerized neuroplasticity-based auditory training delivered in conjunction with computerized social cognition training (SCT) in patients with schizophrenia. Nineteen clinically stable schizophrenia subjects performed 50 hours of computerized exercises that place implicit, increasing demands on auditory perception, plus 12 hours of computerized training in emotion identification, social perception, and theory of mind tasks. All subjects were assessed with MATRICS-recommended measures of neurocognition and social cognition, plus a measure of self-referential source memory before and after the computerized training. Subjects showed significant improvements on multiple measures of neurocognition. Additionally, subjects showed significant gains on measures of social cognition, including the MSCEIT Perceiving Emotions, MSCEIT Managing Emotions, and self-referential source memory, plus a significant decrease in positive symptoms. Computerized training of auditory processing/verbal learning in schizophrenia results in significant basic neurocognitive gains. Further, addition of computerized social cognition training results in significant gains in several social cognitive outcome measures. Computerized cognitive training that directly targets social cognitive processes can drive improvements in these crucial functions.

Improving the utility of the fine motor skills subscale of the comprehensive developmental inventory for infants and toddlers: a computerized adaptive test.

PubMed

Huang, Chien-Yu; Tung, Li-Chen; Chou, Yeh-Tai; Chou, Willy; Chen, Kuan-Lin; Hsieh, Ching-Lin

2017-07-27

This study aimed at improving the utility of the fine motor subscale of the comprehensive developmental inventory for infants and toddlers (CDIIT) by developing a computerized adaptive test of fine motor skills. We built an item bank for the computerized adaptive test of fine motor skills using the fine motor subscale of the CDIIT items fitting the Rasch model. We also examined the psychometric properties and efficiency of the computerized adaptive test of fine motor skills with simulated computerized adaptive tests. Data from 1742 children with suspected developmental delays were retrieved. The mean scores of the fine motor subscale of the CDIIT increased along with age groups (mean scores = 1.36-36.97). The computerized adaptive test of fine motor skills contains 31 items meeting the Rasch model's assumptions (infit mean square = 0.57-1.21, outfit mean square = 0.11-1.17). For children of 6-71 months, the computerized adaptive test of fine motor skills had high Rasch person reliability (average reliability >0.90), high concurrent validity (rs = 0.67-0.99), adequate to excellent diagnostic accuracy (area under receiver operating characteristic = 0.71-1.00), and large responsiveness (effect size = 1.05-3.93). The computerized adaptive test of fine motor skills used 48-84% fewer items than the fine motor subscale of the CDIIT. The computerized adaptive test of fine motor skills used fewer items for assessment but was as reliable and valid as the fine motor subscale of the CDIIT. Implications for Rehabilitation We developed a computerized adaptive test based on the comprehensive developmental inventory for infants and toddlers (CDIIT) for assessing fine motor skills. The computerized adaptive test has been shown to be efficient because it uses fewer items than the original measure and automatically presents the results right after the test is completed. The computerized adaptive test is as reliable and valid as the CDIIT.

Management of seizures in the elderly: a survey of UK geriatricians.

PubMed Central

Stolarek, I H; Brodie, A F; Brodie, M J

1995-01-01

The incidence and prevalence of epilepsy increase substantially with old age. Despite this, the investigation and management of this patient population remains a grey area. Four hundred and eleven (53%) consultant geriatricians responded to a questionnaire exploring their approach to seizures in the elderly in order to establish an overview of current clinical practice. Between one and five patients presenting with seizures, predominantly aged between 75-85 years, were reviewed monthly. Seventy per cent of geriatricians undertook to investigate the patients themselves with biochemical and haematological profiles performed by most. Electroencephalography and computerized tomographic scanning were routinely requested by a quarter of responders. Only 58% would themselves initiate therapy with antiepileptic drugs, with 16% of consultants starting treatment following the first seizure, 59% after a second and 5% after a third. Phenytoin was first choice for generalized tonic-clonic seizures with carbamazepine preferred for partial seizures. If good control was not obtained, 67% would substitute another first line drug, while 27% would add in a second. Less than 3% would use the new anticonvulsants lamotrigine or vigabatrin. Sixty per cent monitored anticonvulsant concentrations in patients with poor control or suspected toxicity. A wide variability was seen in the current approach to seizures in the elderly, which reflects a lack of established practice. Epilepsy clinics for the elderly would encourage structured research into the many unanswered questions affecting the care of older people with seizures. PMID:8786590

Association of Inter-arm Blood Pressure Difference with Asymptomatic Intracranial and Extracranial Arterial Stenosis in Hypertension Patients.

PubMed

Wang, Yan; Zhang, Jin; Qian, Yuesheng; Tang, Xiaofeng; Ling, Huawei; Chen, Kemin; Li, Yan; Gao, Pingjin; Zhu, Dingliang

2016-07-14

Inter-arm blood pressure (BP) difference has been associated with ischemic stroke. Local atherosclerosis of stroke differ among vulnerable individuals, whereas intracranial arterial stenosis (ICAS) is more frequently affected Asians, and extracranial arterial stenosis (ECAS) is more prevalent among whites. We hereby sought to explore the association of inter-arm BP difference with ICAS and ECAS in stroke-free hypertensive patients in Chinese population. All the 885 subjects were evaluated of ICAS and ECAS through computerized tomographic angiography. Both arm BP was measured simultaneously by Vascular Profiler-1000 device. In the continuous study, ICAS was significantly associated with age, male, average brachial SBP, diabetes, anti-hypertensive treatment and inter-arm DBP difference. ECAS was associated with age, inter-arm SBP and LDL. In the categorical study, subjects with the top quartile of inter-arm DBP difference (≥4 mmHg) showed significantly higher risk of ICAS (OR = 2.109; 95% CI, 1.24-3.587). And the participants with the top quartile of inter-arm SBP difference (≥6 mmHg) showed significantly higher risk of ECAS (OR = 2.288; 95% CI, 1.309-3.998). In conclusion, we reported a diverse association of inter-arm SBP/DBP difference with the ICAS/ECAS. Inter-arm DBP difference might be the early symbol of ICAS in Chinese population, which need further verification in long-term cohort study.

Successful Resection of a Large Carotid Body Tumor Masquerading Complete Encasement of the Internal Carotid Artery on Preoperative Imaging.

PubMed

Kakkos, Stavros K; Zampakis, Peter; Lampropoulos, George C; Paridis, Leonidas; Kaplanis, Charalampos; Bantouna, Dimitra; Nikolakopoulos, Konstantinos M; Papageorgopoulou, Chrysanthi P; Kalogeropoulou, Christina; Tsolakis, Ioannis A

2018-05-01

A 41-year-old woman presented with a large painful and tender mass of the left side of her neck located just below the angle of the mandible. She was also complaining of frequent attacks of symptoms ranging from dizziness upon resuming the erect position to frank syncope. Color-coded duplex showed a large well-vascularized vascular mass at the level of the carotid bifurcation, suggesting the diagnosis of a carotid body tumor (CBT). A computerized tomographic angiography confirmed the diagnosis of a CBT, which measured 5.7 cm in its craniocaudal axis. The tumor appeared to encase the internal carotid artery (ICA) at the level of its origin, indicating the presence of a Shamblin group 3 tumor. During surgery, the CBT seemingly encased the ICA; however, it was successfully taken off the ICA, by establishing an adventitial dissection place, obviating the need for arterial resection and replacement. A brief intraoperative episode of cardiac arrest was successfully managed. Postoperative course was uneventful, and all symptoms were cured. Pathology confirmed the clinical diagnosis and did not show malignancy. In conclusion, meticulous surgical techniques can spare the ICA from removal or inadvertent injury during CBT surgery and reduce the morbidity often associated with the resection of large or advanced tumors but also cure atypical patient symptoms.

Regional model-based computerized ionospheric tomography using GPS measurements: IONOLAB-CIT

NASA Astrophysics Data System (ADS)

Tuna, Hakan; Arikan, Orhan; Arikan, Feza

2015-10-01

Three-dimensional imaging of the electron density distribution in the ionosphere is a crucial task for investigating the ionospheric effects. Dual-frequency Global Positioning System (GPS) satellite signals can be used to estimate the slant total electron content (STEC) along the propagation path between a GPS satellite and ground-based receiver station. However, the estimated GPS-STEC is very sparse and highly nonuniformly distributed for obtaining reliable 3-D electron density distributions derived from the measurements alone. Standard tomographic reconstruction techniques are not accurate or reliable enough to represent the full complexity of variable ionosphere. On the other hand, model-based electron density distributions are produced according to the general trends of ionosphere, and these distributions do not agree with measurements, especially for geomagnetically active hours. In this study, a regional 3-D electron density distribution reconstruction method, namely, IONOLAB-CIT, is proposed to assimilate GPS-STEC into physical ionospheric models. The proposed method is based on an iterative optimization framework that tracks the deviations from the ionospheric model in terms of F2 layer critical frequency and maximum ionization height resulting from the comparison of International Reference Ionosphere extended to Plasmasphere (IRI-Plas) model-generated STEC and GPS-STEC. The suggested tomography algorithm is applied successfully for the reconstruction of electron density profiles over Turkey, during quiet and disturbed hours of ionosphere using Turkish National Permanent GPS Network.

[Hepatic fine needle aspiration biopsy. Experience in the study of hepatic masses at the Salvador Zubiran National Institute of Nutrition].

PubMed

Angeles-Angeles, A; Gamboa-Domínguez, A; Velázquez Fernández, D; Muñoz-Fernández, L

1994-01-01

The results of 114 fine-needle aspiration biopsies (FNAB) of the liver performed during six years (1987-1992) at the Departament of Pathology of the Instituto Nacional de la Nutrición Salvador Zubirán are presented. All were done by radiologists under ultrasonographic (three cases) or computerized tomographic guidance (111 cases). In order to determine the diagnostic accuracy, diagnoses made by FNAB were compared with those made by histological examination (coarse biopsies or surgical specimens) and/or by other diagnostic procedures including the clinical follow-up. Six cases were excluded because clinical information was not available. In 92 cases (85.2%) a correct diagnosis was made, in six (5.5%) the sample was inadequate and in 10 (9.3%) the diagnosis made by FNAB was incorrect. The diagnoses made were as follows: hepatocarcinoma 44, metastatic carcinoma 27, inflammatory lesions 12, regeneration 10, normal eight, unclassified carcinoma five, and lymphoma two. The sensitivity was 96.2, specificity 93.1, positive predictive value 97.4, negative predictive value 90.0, accuracy 95.3 and prevalence 73.1. There were three false negative and two false positive for carcinoma. These figures are similar to those found by other authors. No relevant complications were observed. It is concluded that FNAB of the liver is a safe, inexpensive and reliable method in the diagnoses of liver masses.

Compton imaging tomography for nondestructive evaluation of large multilayer aircraft components and structures

NASA Astrophysics Data System (ADS)

Romanov, Volodymyr; Grubsky, Victor; Zahiri, Feraidoon

2017-02-01

We present a novel NDT/NDE tool for non-contact, single-sided 3D inspection of aerospace components, based on Compton Imaging Tomography (CIT) technique, which is applicable to large, non-uniform, and/or multilayer structures made of composites or lightweight metals. CIT is based on the registration of Compton-scattered X-rays, and permits the reconstruction of the full 3D (tomographic) image of the inspected objects. Unlike conventional computerized tomography (CT), CIT requires only single-sided access to objects, and therefore can be applied to large structures without their disassembly. The developed tool provides accurate detection, identification, and precise 3D localizations and measurements of any possible internal and surface defects (corrosions, cracks, voids, delaminations, porosity, and inclusions), and also disbonds, core and skin defects, and intrusion of foreign fluids (e.g., fresh and salt water, oil) inside of honeycomb sandwich structures. The NDE capabilities of the system were successfully demonstrated on various aerospace structure samples provided by several major aerospace companies. Such a CIT-based tool can detect and localize individual internal defects with dimensions about 1-2 mm3, and honeycomb disbond defects less than 6 mm by 6 mm area with the variations in the thickness of the adhesive by 100 m. Current maximum scanning speed of aircraft/spacecraft structures is about 5-8 min/ft2 (50-80 min/m2).

Optimal joule heating of the subsurface

DOEpatents

Berryman, J.G.; Daily, W.D.

1994-07-05

A method for simultaneously heating the subsurface and imaging the effects of the heating is disclosed. This method combines the use of tomographic imaging (electrical resistance tomography or ERT) to image electrical resistivity distribution underground, with joule heating by electrical currents injected in the ground. A potential distribution is established on a series of buried electrodes resulting in energy deposition underground which is a function of the resistivity and injection current density. Measurement of the voltages and currents also permits a tomographic reconstruction of the resistivity distribution. Using this tomographic information, the current injection pattern on the driving electrodes can be adjusted to change the current density distribution and thus optimize the heating. As the heating changes conditions, the applied current pattern can be repeatedly adjusted (based on updated resistivity tomographs) to affect real time control of the heating.

Lamb-Wave-Based Tomographic Imaging Techniques for Hole-Edge Corrosion Monitoring in Plate Structures

PubMed Central

Wang, Dengjiang; Zhang, Weifang; Wang, Xiangyu; Sun, Bo

2016-01-01

This study presents a novel monitoring method for hole-edge corrosion damage in plate structures based on Lamb wave tomographic imaging techniques. An experimental procedure with a cross-hole layout using 16 piezoelectric transducers (PZTs) was designed. The A0 mode of the Lamb wave was selected, which is sensitive to thickness-loss damage. The iterative algebraic reconstruction technique (ART) method was used to locate and quantify the corrosion damage at the edge of the hole. Hydrofluoric acid with a concentration of 20% was used to corrode the specimen artificially. To estimate the effectiveness of the proposed method, the real corrosion damage was compared with the predicted corrosion damage based on the tomographic method. The results show that the Lamb-wave-based tomographic method can be used to monitor the hole-edge corrosion damage accurately. PMID:28774041

A three-dimensional thermal and electromagnetic model of whole limb heating with a MAPA.

PubMed

Charny, C K; Levin, R L

1991-10-01

Previous studies by the authors have shown that if properly implemented, the Pennes assumptions can be applied to quantify bioheat transfer during extremity heating. Given its relative numerical simplicity and its ability to predict temperatures in thermoregulated tissue, the Pennes model of bioheat transfer was utilized in a three-dimensional thermal model of limb heating. While the arterial blood temperature was assumed to be radially uniform within a cross section of the limb, axial gradients in the arterial and venous blood temperatures were computed with this three-dimensional model. A realistically shaped, three-dimensional finite element model of a tumor-bearing human lower leg was constructed and was "attached" mathematically to the whole body thermal model of man described in previous studies by the authors. The central as well as local thermoregulatory feedback control mechanisms which determine blood perfusion to the various tissues and rate of evaporation by sweating were input into the limb model. In addition, the temperature of the arterial blood which feeds into the most proximal section of the lower leg was computed by the whole body thermal model. The variations in the shape of the tissues which comprise the limb were obtained from computerized tomography scans. Axial variations in the energy deposition patterns along the length of the limb exposed to a miniannular phased array (MAPA) applicator were also input into this model of limb heating. Results indicate that proper positioning of the limb relative to the MAPA is a significant factor in determining the effectiveness of the treatment. A patient-specific hyperthermia protocol can be designed using this coupled electromagnetic and thermal model.

Morphometric anatomical and CT study of the human adult sacroiliac region.

PubMed

Postacchini, Roberto; Trasimeni, Guido; Ripani, Francesca; Sessa, Pasquale; Perotti, Stefano; Postacchini, Franco

2017-01-01

To identify and describe the morphometry and CT features of the articular and extra-articular portions of the sacroiliac region. The resulting knowledge might help to avoid complications in sacroiliac joint (SIJ) fusion. We analyzed 102 dry hemi-sacra, 80 ilia, and 10 intact pelves and assessed the pelvic computerized tomography (CT) scans of 90 patients, who underwent the examination for conditions not involving the pelvis. We assessed both the posterior aspect of sacrum with regard to the depressions located externally to the lateral sacral crest at the level of the proximal three sacral vertebrae and the posteroinferior aspect of ilium. Coronal and axial CT scans of the SIJ of patients were obtained and the joint space was measured. On each side, the sacrum exhibits three bone depressions, not described in anatomic textbooks or studies, facing the medial aspect of the posteroinferior ilium, not yet described in detail. Both structures are extra-articular portions situated posteriorly to the SIJ. Coronal CT scans of patients showing the first three sacral foramens and the interval between sacrum and ilium as a continuous space display only the S1 and S3 portions of SIJ, the intermediate portion being extra-articular. The S2 portion is visible on the most anterior coronal scan. Axial scans show articular and extra-articular portions and features improperly described as anatomic variations. Extra-articular portions of the sacroiliac region, not yet described exhaustively, have often been confused with SIJ. Coronal CT scans through the middle part of sacrum, the most used to evaluate degenerative and inflammatory conditions of SIJ, show articular and extra-articular portions of the region.

45 CFR 310.40 - What requirements apply for accessing systems and records for monitoring Computerized Tribal IV-D...

Code of Federal Regulations, 2010 CFR

2010-10-01

... records for monitoring Computerized Tribal IV-D Systems and Office Automation? 310.40 Section 310.40... COMPUTERIZED TRIBAL IV-D SYSTEMS AND OFFICE AUTOMATION Accountability and Monitoring Procedures for... monitoring Computerized Tribal IV-D Systems and Office Automation? In accordance with Part 95 of this title...

[In vitro study with techniques of imaging of the composition of urinary calculi].

PubMed

Tellez Martínez-Fornés, M; Burgos Revilla, F J; Sáez Garrido, J C; Soria Descalzo, J; Barbero González, J; Sánchez Corral, J; Minaya Minaya, A; Vallejo Herrador, J

1997-02-01

Pre-treatment knowledge of the lithiasic composition can be useful to design the most appropriate therapeutic scheme for each kind of stone. The relationship between the stone's densitometry information provided by the different imaging techniques, conventional radiology (RX), computerized axial tomography (CAT) and dual energy radiographic densitometry (DO) is analyzed, as well as the elemental composition determined by the microanalysis of fragments obtained post-lithotrity using a scanning electronic microscope (SEM) associated to X-ray dispersion energy (XDE). 60 stones, 12 for each pure composition selected (calcium oxalate mono and dihydro, phosphocarbonate, magnesium ammonium phosphate and uric acid), were studied with XR, CAT and DO and were later subjected to lithofragmentation in vitro. Fragments analysis was carried out post-lithotrity with SEM associated to XDE. The X-ray does not allow to establish the composition of some calculi. CAT quantifies the mineral contents of the oxalocalcic and infective calculi and differentiates the uric acid from the other compositions because the mean density values are under 500 Hounsfield Units. DO evaluates the lithiasic content in phosphocarbonate salts which are structurally similar to bone hydroxyapatite.

Clinical recommendation for treatment planning of sinus augmentation procedures by using presurgical CAT scan images: a preliminary report.

PubMed

Kutkut, Ahmad M; Andreana, Sebastiano; Kim, Hyeong-Ll; Monaco, Edward

2011-12-01

To propose a clinical recommendation based on anatomy of maxillary sinus before sinus augmentation procedure using presurgical computerized axial tomography (CAT) scan images. CAT scan images were randomly selected from previous completed implant cases. Proposed area for the lateral window osteotomy was outlined on the panorex image of the CAT scan. Sagittal section on the CAT scan that was in the center of the outlined window was selected for sinus measurement analysis. On CAT scan, 2 lines were drawn to measure the dimensions of sinus. One line measured the horizontal width and the other line measured the vertical height. Based on the measurement data, a classification of the maxillary sinus anatomy was proposed. Narrow sinus cavity indicates favorable type anatomy in terms of bone regeneration healing and wide sinus cavity as less favorable anatomy for patient treatment planning. A narrow sinus and greater exposure to the blood supply should require shorter healing times after grafting. Conversely, wider sinus cavities and less exposure to the blood supply would require a longer healing time before implant placement.

Analyzing the evolution of young people's brain cancer mortality in Spanish provinces.

PubMed

Ugarte, M D; Adin, A; Goicoa, T; López-Abente, G

2015-06-01

To analyze the spatio-temporal evolution of brain cancer relative mortality risks in young population (under 20 years of age) in Spanish provinces during the period 1986-2010. A new and flexible conditional autoregressive spatio-temporal model with two levels of spatial aggregation was used. Brain cancer relative mortality risks in young population in Spanish provinces decreased during the last years, although a clear increase was observed during the 1990s. The global geographical pattern emphasized a high relative mortality risk in Navarre and a low relative mortality risk in Madrid. Although there is a specific Autonomous Region-time interaction effect on the relative mortality risks this effect is weak in the final estimates when compared to the global spatial and temporal effects. Differences in mortality between regions and over time may be caused by the increase in survival rates, the differences in treatment or the availability of diagnostic tools. The increase in relative risks observed in the 1990s was probably due to improved diagnostics with computerized axial tomography and magnetic resonance imaging techniques. Copyright © 2015 Elsevier Ltd. All rights reserved.

A 3D gantry single photon emission tomograph with hemispherical coverage for dedicated breast imaging

NASA Astrophysics Data System (ADS)

Tornai, Martin P.; Bowsher, James E.; Archer, Caryl N.; Peter, Jörg; Jaszczak, Ronald J.; MacDonald, Lawrence R.; Patt, Bradley E.; Iwanczyk, Jan S.

2003-01-01

A novel tomographic gantry was designed, built and initially evaluated for single photon emission imaging of metabolically active lesions in the pendant breast and near chest wall. Initial emission imaging measurements with breast lesions of various uptake ratios are presented. Methods: A prototype tomograph was constructed utilizing a compact gamma camera having a field-of-view of <13×13 cm 2 with arrays of 2×2×6 mm 3 quantized NaI(Tl) scintillators coupled to position sensitive PMTs. The camera was mounted on a radially oriented support with 6 cm variable radius-of-rotation. This unit is further mounted on a goniometric cradle providing polar motion, and in turn mounted on an azimuthal rotation stage capable of indefinite vertical axis-of-rotation about the central rotation axis (RA). Initial measurements with isotopic Tc-99 m (140 keV) to evaluate the system include acquisitions with various polar tilt angles about the RA. Tomographic measurements were made of a frequency and resolution cold-rod phantom filled with aqueous Tc-99 m. Tomographic and planar measurements of 0.6 and 1.0 cm diameter fillable spheres in an available ˜950 ml hemi-ellipsoidal (uncompressed) breast phantom attached to a life-size anthropomorphic torso phantom with lesion:breast-and-body:cardiac-and-liver activity concentration ratios of 11:1:19 were compared. Various photopeak energy windows from 10-30% widths were obtained, along with a 35% scatter window below a 15% photopeak window from the list mode data. Projections with all photopeak window and camera tilt conditions were reconstructed with an ordered subsets expectation maximization (OSEM) algorithm capable of reconstructing arbitrary tomographic orbits. Results: As iteration number increased for the tomographically measured data at all polar angles, contrasts increased while signal-to-noise ratios (SNRs) decreased in the expected way with OSEM reconstruction. The rollover between contrast improvement and SNR degradation of the lesion occurred at two to three iterations. The reconstructed tomographic data yielded SNRs with or without scatter correction that were >9 times better than the planar scans. There was up to a factor of ˜2.5 increase in total primary and scatter contamination in the photopeak window with increasing tilt angle from 15° to 45°, consistent with more direct line-of-sight of myocardial and liver activity with increased camera polar angle. Conclusion: This new, ultra-compact, dedicated tomographic imaging system has the potential of providing valuable, fully 3D functional information about small, otherwise indeterminate breast lesions as an adjunct to diagnostic mammography.

A high-throughput system for high-quality tomographic reconstruction of large datasets at Diamond Light Source

PubMed Central

Atwood, Robert C.; Bodey, Andrew J.; Price, Stephen W. T.; Basham, Mark; Drakopoulos, Michael

2015-01-01

Tomographic datasets collected at synchrotrons are becoming very large and complex, and, therefore, need to be managed efficiently. Raw images may have high pixel counts, and each pixel can be multidimensional and associated with additional data such as those derived from spectroscopy. In time-resolved studies, hundreds of tomographic datasets can be collected in sequence, yielding terabytes of data. Users of tomographic beamlines are drawn from various scientific disciplines, and many are keen to use tomographic reconstruction software that does not require a deep understanding of reconstruction principles. We have developed Savu, a reconstruction pipeline that enables users to rapidly reconstruct data to consistently create high-quality results. Savu is designed to work in an ‘orthogonal’ fashion, meaning that data can be converted between projection and sinogram space throughout the processing workflow as required. The Savu pipeline is modular and allows processing strategies to be optimized for users' purposes. In addition to the reconstruction algorithms themselves, it can include modules for identification of experimental problems, artefact correction, general image processing and data quality assessment. Savu is open source, open licensed and ‘facility-independent’: it can run on standard cluster infrastructure at any institution. PMID:25939626

Tomographic inversion of satellite photometry. II

NASA Technical Reports Server (NTRS)

Solomon, S. C.; Hays, P. B.; Abreu, V. J.

1985-01-01

A method for combining nadir observations of emission features in the upper atmosphere with the result of a tomographic inversion of limb brightness measurements is presented. Simulated and actual results are provided, and error sensitivity is investigated.

Efficient control schemes with limited computation complexity for Tomographic AO systems on VLTs and ELTs

NASA Astrophysics Data System (ADS)

Petit, C.; Le Louarn, M.; Fusco, T.; Madec, P.-Y.

2011-09-01

Various tomographic control solutions have been proposed during the last decades to ensure efficient or even optimal closed-loop correction to tomographic Adaptive Optics (AO) concepts such as Laser Tomographic AO (LTAO), Multi-Conjugate AO (MCAO). The optimal solution, based on Linear Quadratic Gaussian (LQG) approach, as well as suboptimal but efficient solutions such as Pseudo-Open Loop Control (POLC) require multiple Matrix Vector Multiplications (MVM). Disregarding their respective performance, these efficient control solutions thus exhibit strong increase of on-line complexity and their implementation may become difficult in demanding cases. Among them, two cases are of particular interest. First, the system Real-Time Computer architecture and implementation is derived from past or present solutions and does not support multiple MVM. This is the case of the AO Facility which RTC architecture is derived from the SPARTA platform and inherits its simple MVM architecture, which does not fit with LTAO control solutions for instance. Second, considering future systems such as Extremely Large Telescopes, the number of degrees of freedom is twenty to one hundred times bigger than present systems. In these conditions, tomographic control solutions can hardly be used in their standard form and optimized implementation shall be considered. Single MVM tomographic control solutions represent a potential solution, and straightforward solutions such as Virtual Deformable Mirrors have been already proposed for LTAO but with tuning issues. We investigate in this paper the possibility to derive from tomographic control solutions, such as POLC or LQG, simplified control solutions ensuring simple MVM architecture and that could be thus implemented on nowadays systems or future complex systems. We theoretically derive various solutions and analyze their respective performance on various systems thanks to numerical simulation. We discuss the optimization of their performance and stability issues with respect to classic control solutions. We finally discuss off-line computation and implementation constraints.

Computerized adaptive control weld skate with CCTV weld guidance project

NASA Technical Reports Server (NTRS)

Wall, W. A.

1976-01-01

This report summarizes progress of the automatic computerized weld skate development portion of the Computerized Weld Skate with Closed Circuit Television (CCTV) Arc Guidance Project. The main goal of the project is to develop an automatic welding skate demonstration model equipped with CCTV weld guidance. The three main goals of the overall project are to: (1) develop a demonstration model computerized weld skate system, (2) develop a demonstration model automatic CCTV guidance system, and (3) integrate the two systems into a demonstration model of computerized weld skate with CCTV weld guidance for welding contoured parts.

Assessing the resolution-dependent utility of tomograms for geostatistics

USGS Publications Warehouse

Day-Lewis, F. D.; Lane, J.W.

2004-01-01

Geophysical tomograms are used increasingly as auxiliary data for geostatistical modeling of aquifer and reservoir properties. The correlation between tomographic estimates and hydrogeologic properties is commonly based on laboratory measurements, co-located measurements at boreholes, or petrophysical models. The inferred correlation is assumed uniform throughout the interwell region; however, tomographic resolution varies spatially due to acquisition geometry, regularization, data error, and the physics underlying the geophysical measurements. Blurring and inversion artifacts are expected in regions traversed by few or only low-angle raypaths. In the context of radar traveltime tomography, we derive analytical models for (1) the variance of tomographic estimates, (2) the spatially variable correlation with a hydrologic parameter of interest, and (3) the spatial covariance of tomographic estimates. Synthetic examples demonstrate that tomograms of qualitative value may have limited utility for geostatistics; moreover, the imprint of regularization may preclude inference of meaningful spatial statistics from tomograms.

Subsurface PpIX imaging in vivo with ultrasound-guided tomographic spectroscopy: reconstruction vs. born-normalized data

NASA Astrophysics Data System (ADS)

Flynn, Brendan P.; D'Souza, Alisha V.; Kanick, Stephen C.; Maytin, Edward; Hasan, Tayyaba; Pogue, Brian W.

2013-03-01

Aminolevulinic acid (ALA)-induced Protoporphyrin IX (PpIX)-based photodynamic therapy (PDT) is an effective treatment for skin cancers including basal cell carcinoma (BCC). Topically applied ALA promotes PpIX production preferentially in tumors, and many strategies have been developed to increase PpIX distribution and PDT treatment efficacy at depths > 1mm is not fully understood. While surface imaging techniques provide useful diagnosis, dosimetry, and efficacy information for superficial tumors, these methods cannot interrogate deeper tumors to provide in situ insight into spatial PpIX distributions. We have developed an ultrasound-guided, white-light-informed, tomographics spectroscopy system for the spatial measurement of subsurface PpIX. Detailed imaging system specifications, methodology, and optical-phantom-based characterization will be presented separately. Here we evaluate preliminary in vivo results using both full tomographic reconstruction and by plotting individual tomographic source-detector pair data against US images.

Increasing profitability through computerization.

PubMed

Sokol, D J

1988-01-01

The author explores the pragmatic or financial justification for computerizing a dental practice and discusses a computerized approach to precollection and collection for the dental office. The article also deals with the use of computerized correspondence to augment the recall policy of the office and to help generate new patient referrals and discusses the pros and cons of utilizing a dental computer service bureau in implementing these policies.

Influence of the limited detector size on spatial variations of the reconstruction accuracy in holographic tomography

NASA Astrophysics Data System (ADS)

Kostencka, Julianna; Kozacki, Tomasz; Hennelly, Bryan; Sheridan, John T.

2017-06-01

Holographic tomography (HT) allows noninvasive, quantitative, 3D imaging of transparent microobjects, such as living biological cells and fiber optics elements. The technique is based on acquisition of multiple scattered fields for various sample perspectives using digital holographic microscopy. Then, the captured data is processed with one of the tomographic reconstruction algorithms, which enables 3D reconstruction of refractive index distribution. In our recent works we addressed the issue of spatially variant accuracy of the HT reconstructions, which results from the insufficient model of diffraction that is applied in the widely-used tomographic reconstruction algorithms basing on the Rytov approximation. In the present study, we continue investigating the spatially variant properties of the HT imaging, however, we are now focusing on the limited spatial size of holograms as a source of this problem. Using the Wigner distribution representation and the Ewald sphere approach, we show that the limited size of the holograms results in a decreased quality of tomographic imaging in off-center regions of the HT reconstructions. This is because the finite detector extent becomes a limiting aperture that prohibits acquisition of full information about diffracted fields coming from the out-of-focus structures of a sample. The incompleteness of the data results in an effective truncation of the tomographic transfer function for the out-of-center regions of the tomographic image. In this paper, the described effect is quantitatively characterized for three types of the tomographic systems: the configuration with 1) object rotation, 2) scanning of the illumination direction, 3) the hybrid HT solution combing both previous approaches.

Influence of computerized sounding out on spelling performance for children who do and do not rely on AAC.

PubMed

McCarthy, Jillian H; Hogan, Tiffany P; Beukelman, David R; Schwarz, Ilsa E

2015-05-01

Spelling is an important skill for individuals who rely on augmentative and alternative communication (AAC). The purpose of this study was to investigate how computerized sounding out influenced spelling accuracy of pseudo-words. Computerized sounding out was defined as a word elongated, thus providing an opportunity for a child to hear all the sounds in the word at a slower rate. Seven children with cerebral palsy, four who use AAC and three who do not, participated in a single subject AB design. The results of the study indicated that the use of computerized sounding out increased the phonologic accuracy of the pseudo-words produced by participants. The study provides preliminary evidence for the use of computerized sounding out during spelling tasks for children with cerebral palsy who do and do not use AAC. Future directions and clinical implications are discussed. We investigated how computerized sounding out influenced spelling accuracy of pseudowords for children with complex communication needs who did and did not use augmentative and alternative communication (AAC). Results indicated that the use of computerized sounding out increased the phonologic accuracy of the pseudo-words by participants, suggesting that computerized sounding out might assist in more accurate spelling for children who use AAC. Future research is needed to determine how language and reading abilities influence the use of computerized sounding out with children who have a range of speech intelligibility abilities and do and do not use AAC.

Carotid body size measured by computed tomographic angiography in individuals born prematurely.

PubMed

Bates, Melissa L; Welch, Brian T; Randall, Jess T; Petersen-Jones, Humphrey G; Limberg, Jacqueline K

2018-05-24

We tested the hypothesis that the carotid bodies would be smaller in individuals born prematurely or exposed to perinatal oxygen therapy when compared individuals born full term that did not receive oxygen therapy. A retrospective chart review was conducted on patients who underwent head/neck computed tomography angiography (CTA) at the Mayo Clinic between 10 and 40 years of age (n = 2503). Patients were identified as premature ( < 38 weeks) or receiving perinatal oxygen therapy by physician completion or billing codes (n = 16 premature and n = 7 receiving oxygen). Widest axial measurements of the carotid body images captured during the CTA were performed. Carotid body visualization was possible in 43% of patients and 52% of age, sex, and body mass index (BMI)-matched controls but only 17% of juvenile preterm subjects (p = 0.07). Of the carotid bodies that could be visualized, widest axial measurements of the carotid bodies in individuals born prematurely (n = 7, 34 ± 4 weeks gestation, birth weight: 2460 ± 454 g; average size: 2.5 ± 0.2 cm) or individuals exposed to perinatal oxygen therapy (n = 3, 38 ± 2 weeks gestation, Average size: 2.2 ± 0.1 cm) were not different when compared to controls (2.3 ± 0.2 cm and 2.3 ± 0.2 cm, respectively, p > 0.05). Carotid body size, as measured using CTA, is not smaller in adults born prematurely or exposed to perinatal oxygen therapy when compared to sex, age, and BMI-matched controls. However, carotid body visualization was lower in juvenile premature patients. The decreased ability to visualize the carotid bodies in these individuals may be a result of their prematurity. Copyright © 2018. Published by Elsevier B.V.

Performance Evaluation and Initial Clinical Test of the Positron Emission Mammography System (PEMi)

NASA Astrophysics Data System (ADS)

Li, Lin; Gu, Xiao-Yue; Li, Dao-Wu; Huang, Xian-Chao; Chai, Pei; Feng, Bao-Tong; Wang, Pei-Lin; Yun, Ming-Kai; Dai, Dong; Zhang, Zhi-Ming; Yin, Peng-Fei; Xu, Wen-Gui; Wei, Long

2015-10-01

A new polygon positron emission mammography imaging system (PEMi) was developed in 2009 by the Institute of High Energy Physics, Chinese Academy of Sciences. PEMi is constructed in a polygon structure with lutetium yttrium orthosilicate crystal arrays mounted on a position-sensitive photomultiplier. The system consists of 64 blocks and each block is arranged in 16 ×16 crystal arrays with a pixel size of 1.9 ×1.9 ×15 mm. The diameter of the detector ring is 166 mm, and the axial length is 128 mm. The transaxial field of view of PEMi is 110 mm. The goal of the initial study was to test PEMi's performance and the clinical imaging ability with a small group of selected subjects. The detectors have a measured intrinsic spatial resolution averaging 1.67 mm. The axial and tangential resolution remained under 2.5-mm full width at half maximum within the central 5-cm diameter of the field of view. The hot rods with a diameter of 1.7 mm can be clearly identified, and the structure of the region containing 1.35-mm diameter rods can also be observed. Using a 6-ns coincidence timing window and a 360 660-keV energy window, the peak sensitivity of the tomograph is 6.88%. The noise-equivalent count rate peak is 110 766 cps for a breast-like cylindrical phantom of 100 mm in diameter at an activity concentration of 0.03 MBq/cc. The recovery coefficients ranged from 0.21 to 0.85 for rods between 1 mm and 5 mm in the image-quality phantom. The reconstructed image resolution achieved an improvement compared with whole-body positron emission tomography (PET), which might reduce the lower threshold on detectable lesion size. Example patient images demonstrate that PEMi is clinically feasible. And more detailed structure information was obtained with PEMi than with the whole-body PET imaging.

Estimating Patient Dose from X-ray Tube Output Metrics: Automated Measurement of Patient Size from CT Images Enables Large-scale Size-specific Dose Estimates

PubMed Central

Ikuta, Ichiro; Warden, Graham I.; Andriole, Katherine P.; Khorasani, Ramin

2014-01-01

Purpose To test the hypothesis that patient size can be accurately calculated from axial computed tomographic (CT) images, including correction for the effects of anatomy truncation that occur in routine clinical CT image reconstruction. Materials and Methods Institutional review board approval was obtained for this HIPAA-compliant study, with waiver of informed consent. Water-equivalent diameter (DW) was computed from the attenuation-area product of each image within 50 adult CT scans of the thorax and of the abdomen and pelvis and was also measured for maximal field of view (FOV) reconstructions. Linear regression models were created to compare DW with the effective diameter (Deff) used to select size-specific volume CT dose index (CTDIvol) conversion factors as defined in report 204 of the American Association of Physicists in Medicine. Linear regression models relating reductions in measured DW to a metric of anatomy truncation were used to compensate for the effects of clinical image truncation. Results In the thorax, DW versus Deff had an R2 of 0.51 (n = 200, 50 patients at four anatomic locations); in the abdomen and pelvis, R2 was 0.90 (n = 150, 50 patients at three anatomic locations). By correcting for image truncation, the proportion of clinically reconstructed images with an extracted DW within ±5% of the maximal FOV DW increased from 54% to 90% in the thorax (n = 3602 images) and from 95% to 100% in the abdomen and pelvis (6181 images). Conclusion The DW extracted from axial CT images is a reliable measure of patient size, and varying degrees of clinical image truncation can be readily corrected. Automated measurement of patient size combined with CT radiation exposure metrics may enable patient-specific dose estimation on a large scale. © RSNA, 2013 PMID:24086075

TOmographic Remote Observer of Ionospheric Disturbances

DTIC Science & Technology

2007-11-15

ionosphere . The proposed spacecraft was an evolutionary design from the USUSat, Combat Sentinel, and USUSat II programs whose histories are shown in...Figure 1. The primary science instrument, TOROID for TOmographic Remote Observer of Ionospheric Disturbances, is a photometer for measuring the

Acoustic representation of tomographic data

NASA Astrophysics Data System (ADS)

Wampler, Cheryl; Zahrt, John D.; Hotchkiss, Robert S.; Zahrt, Rebecca; Kust, Mark

1993-04-01

Tomographic data and tomographic reconstructions are naturally periodic in the angle of rotation of the turntable and the polar angel of the coordinates in the object, respectively. Similarly, acoustic waves are periodic and have amplitude and wavelength as free parameters that can be fit to another representation. Work has been in progress for some time in bringing the acoustic senses to bear on large data sets rather than just the visual sense. We will provide several different acoustic representations of both raw data and density maps. Rather than graphical portrayal of the data and reconstructions, you will be presented various 'tone poems.'

Optical tomograph optimized for tumor detection inside highly absorbent organs

NASA Astrophysics Data System (ADS)

Boutet, Jérôme; Koenig, Anne; Hervé, Lionel; Berger, Michel; Dinten, Jean-Marc; Josserand, Véronique; Coll, Jean-Luc

2011-05-01

This paper presents a tomograph for small animal fluorescence imaging. The compact and cost-effective system described in this article was designed to address the problem of tumor detection inside highly absorbent heterogeneous organs, such as lungs. To validate the tomograph's ability to detect cancerous nodules inside lungs, in vivo tumor growth was studied on seven cancerous mice bearing murine mammary tumors marked with Alexa Fluor 700. They were successively imaged 10, 12, and 14 days after the primary tumor implantation. The fluorescence maps were compared over this time period. As expected, the reconstructed fluorescence increases with the tumor growth stage.

Lamb wave tomographic imaging system for aircraft structural health assessment

NASA Astrophysics Data System (ADS)

Schwarz, Willi G.; Read, Michael E.; Kremer, Matthew J.; Hinders, Mark K.; Smith, Barry T.

1999-01-01

A tomographic imaging system using ultrasonic Lamb waves for the nondestructive inspection of aircraft components such as wings and fuselage is being developed. The computer-based system provides large-area inspection capability by electronically scanning an array of transducers that can be easily attached to flat and curved surface without moving parts. Images of the inspected area are produced in near real time employing a tomographic reconstruction method adapted from seismological applications. Changes in material properties caused by structural flaws such as disbonds, corrosion, and fatigue cracks can be effectively detected and characterized utilizing this fast NDE technique.

Sodankylä ionospheric tomography dataset 2003-2014

NASA Astrophysics Data System (ADS)

Norberg, J.; Roininen, L.; Kero, A.; Raita, T.; Ulich, T.; Markkanen, M.; Juusola, L.; Kauristie, K.

2015-12-01

Sodankylä Geophysical Observatory has been operating a tomographic receiver network and collecting the produced data since 2003. The collected dataset consists of phase difference curves measured from Russian COSMOS dual-frequency (150/400 MHz) low-Earth-orbit satellite signals, and tomographic electron density reconstructions obtained from these measurements. In this study vertical total electron content (VTEC) values are integrated from the reconstructed electron densities to make a qualitative and quantitative analysis to validate the long-term performance of the tomographic system. During the observation period, 2003-2014, there were three-to-five operational stations at the Fenno-Scandinavian sector. Altogether the analysis consists of around 66 000 overflights, but to ensure the quality of the reconstructions, the examination is limited to cases with descending (north to south) overflights and maximum elevation over 60°. These constraints limit the number of overflights to around 10 000. Based on this dataset, one solar cycle of ionospheric vertical total electron content estimates is constructed. The measurements are compared against International Reference Ionosphere IRI-2012 model, F10.7 solar flux index and sunspot number data. Qualitatively the tomographic VTEC estimate corresponds to reference data very well, but the IRI-2012 model are on average 40 % higher of that of the tomographic results.

11 CFR 9033.12 - Production of computerized information.

Code of Federal Regulations, 2012 CFR

2012-01-01

... conform to the technical specifications, including file requirements, described in the Federal Election Commission's Computerized Magnetic Media Requirements for title 26 Candidates/Committees Receiving Federal... outstanding campaign obligations. (b) Organization of computerized information and technical specifications...

11 CFR 9033.12 - Production of computerized information.

Code of Federal Regulations, 2014 CFR

2014-01-01

... conform to the technical specifications, including file requirements, described in the Federal Election Commission's Computerized Magnetic Media Requirements for title 26 Candidates/Committees Receiving Federal... outstanding campaign obligations. (b) Organization of computerized information and technical specifications...

11 CFR 9033.12 - Production of computerized information.

Code of Federal Regulations, 2013 CFR

2013-01-01

... conform to the technical specifications, including file requirements, described in the Federal Election Commission's Computerized Magnetic Media Requirements for title 26 Candidates/Committees Receiving Federal... outstanding campaign obligations. (b) Organization of computerized information and technical specifications...

Microcomputer Network for Computerized Adaptive Testing (CAT)

DTIC Science & Technology

1984-03-01

PRDC TR 84-33 \\Q.�d-33- \\ MICROCOMPUTER NETWOJlt FOR COMPUTERIZED ADAPTIVE TESTING ( CAT ) Baldwin Quan Thomas A . Park Gary Sandahl John H...ACCEIIION NO NPRDC TR 84-33 4. TITLE (-d Sul>tlllo) MICROCOMP UTER NETWORK FOR COMPUTERIZED ADA PTIVE TESTING ( CAT ) 1. Q B. uan T. A . Park...adaptive testing ( CAT ) Bayesian sequential testing 20. ABSTitACT (Continuo on ro•••• aide II noco .. _, _., ld-tlly ,.,. t.loclt _._.) DO Computerized

Computerized Adaptive Testing (CAT): A User Manual

DTIC Science & Technology

1984-03-12

NPRDC TR 84-32 COMPUTERIZED ADAPTIVE TESTING ( CAT ): A USER MANUAL Susan Hardwick Lawrence Eastman Ross Cooper Rehab Group, Incorporated San...a ~EI’IOD COVIRED COMPUTERIZED ADAPTIVE TESTING ( CAT ) Final Report Aug 1981-June 1982 A USER MANUAL 1. ~l:l’t,ORMINCI ORCI. RE~ORT NUM.I:R 62-83...II nee• .. _, entl ldentll)’ ,,. llloclr _,.,) A joint-service effort is underway to develop a computerized adaptive testing ( CAT ) system and to

Digital holography applications in ophthalmology, biometry, and optical trapping characterization

NASA Astrophysics Data System (ADS)

Potcoava, Mariana Camelia

This dissertation combines various holographic techniques with application on the two- and three-dimensional imaging of ophthalmic tissue, fingerprints, and microsphere samples with micrometer resolution. Digital interference holography (DIH) uses scanned wavelengths to synthesize short-coherence interference tomographic images. We used DIH for in vitro imaging of human optic nerve head and retina. Tomographic images were produced by superposition of holograms. Holograms were obtained with a signal-to-noise ratio of approximately 50 dB. Optic nerve head characteristics (shape, diameter, cup depth, and cup width) were quantified with a few micron resolution (4.06--4.8mum). Multiple layers were distinguishable in cross-sectional images of the macula. To our knowledge, this is the first report of DIH use to image human macular and optic nerve tissue. Holographic phase microscopy is used to produce images of thin film patterns left by latent fingerprints. Two or more holographic phase images with different wavelengths are combined for optical phase unwrapping of images of patent prints. We demonstrated digital interference holography images of a plastic print, and latent prints. These demonstrations point to significant contributions to biometry by using digital interference holography to identify and quantify Level 1 (pattern), Level 2 (minutia points), and Level 3 (pores and ridge contours). Quantitative studies of physical and biological processes and precise non-contact manipulation of nanometer/micrometer trapped objects can be effectuated with nanometer accuracy due to the development of optical tweezers. A three-dimensional gradient trap is produced at the focus position of a high NA microscope objective. Particles are trapped axially and laterally due to the gradient force. The particle is confined in a potential well and the trap acts as a harmonic spring. The elastic constant or the stiffness along any axis is determined from the particle displacements in time along each specific axis. Thus, we report the sensing of small particles using optical trapping in combination with the digital Gabor holography to calibrate the optical force and the position and of the copolymer microsphere in the x, y, z direction with nm precision.

Is it necessary to diagnose levator avulsion on pelvic floor muscle contraction?

PubMed

Dietz, H P; Pattillo Garnham, A; Guzmán Rojas, R

2017-02-01

Avulsion of the levator ani muscle commonly occurs at vaginal birth. This condition is usually diagnosed by translabial ultrasound (TLUS) during pelvic floor muscle contraction (PFMC). Some patients are unable to achieve a satisfactory PFMC and in these cases avulsion is assessed at rest. The aim of this study was to validate the diagnosis of levator avulsion by means of TLUS at rest. This was a retrospective study of 233 women seen at a tertiary urogynecological center. All women underwent four-dimensional TLUS in the supine position and after voiding. Volumes were obtained on maximal PFMC and at rest. Analysis of the volumes was performed with the observer blinded against all clinical data. Avulsion was defined as an abnormal levator ani muscle insertion that was visible in at least three consecutive axial plane slices, at and above the level of minimal hiatal dimensions, at 2.5-mm intervals. We examined the correlation between both assessment methods using Cohen's kappa coefficient and tested the association of each method with female pelvic organ prolapse on clinical examination, organ descent on ultrasound and hiatal ballooning. In total, datasets from 202 women were available for analysis. The correlation between a diagnosis of avulsion in volumes obtained at rest and those on PFMC was moderate, with a kappa value of 0.583 (95% CI, 0.484-0.683). Agreement for defects visualized on single slices was moderate, with a kappa value of 0.556 (95% CI, 0.520-0.591). When avulsion diagnoses at rest and on PFMC were tested against symptoms of prolapse, and prolapse on clinical examination and on ultrasound, neither of the two methods was superior. Although tomographic ultrasound imaging during PFMC enhances tissue discrimination, this may not translate to superior diagnostic performance. Hence, volumes obtained at rest may be used in women unable to contract their pelvic floor. The diagnosis of levator avulsion by tomographic pelvic floor ultrasound is equally valid when performed at rest or on PFMC. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

NEMA NU-4 performance evaluation of PETbox4, a high sensitivity dedicated PET preclinical tomograph

NASA Astrophysics Data System (ADS)

Gu, Z.; Taschereau, R.; Vu, N. T.; Wang, H.; Prout, D. L.; Silverman, R. W.; Bai, B.; Stout, D. B.; Phelps, M. E.; Chatziioannou, A. F.

2013-06-01

PETbox4 is a new, fully tomographic bench top PET scanner dedicated to high sensitivity and high resolution imaging of mice. This manuscript characterizes the performance of the prototype system using the National Electrical Manufacturers Association NU 4-2008 standards, including studies of sensitivity, spatial resolution, energy resolution, scatter fraction, count-rate performance and image quality. The PETbox4 performance is also compared with the performance of PETbox, a previous generation limited angle tomography system. PETbox4 consists of four opposing flat-panel type detectors arranged in a box-like geometry. Each panel is made by a 24 × 50 pixelated array of 1.82 × 1.82 × 7 mm bismuth germanate scintillation crystals with a crystal pitch of 1.90 mm. Each of these scintillation arrays is coupled to two Hamamatsu H8500 photomultiplier tubes via a glass light guide. Volumetric images for a 45 × 45 × 95 mm field of view (FOV) are reconstructed with a maximum likelihood expectation maximization algorithm incorporating a system model based on a parameterized detector response. With an energy window of 150-650 keV, the peak absolute sensitivity is approximately 18% at the center of FOV. The measured crystal energy resolution ranges from 13.5% to 48.3% full width at half maximum (FWHM), with a mean of 18.0%. The intrinsic detector spatial resolution is 1.5 mm FWHM in both transverse and axial directions. The reconstructed image spatial resolution for different locations in the FOV ranges from 1.32 to 1.93 mm, with an average of 1.46 mm. The peak noise equivalent count rate for the mouse-sized phantom is 35 kcps for a total activity of 1.5 MBq (40 µCi) and the scatter fraction is 28%. The standard deviation in the uniform region of the image quality phantom is 5.7%. The recovery coefficients range from 0.10 to 0.93. In comparison to the first generation two panel PETbox system, PETbox4 achieves substantial improvements on sensitivity and spatial resolution. The overall performance demonstrates that the PETbox4 scanner is suitable for producing high quality images for molecular imaging based biomedical research.

Tomographic Image Compression Using Multidimensional Transforms.

ERIC Educational Resources Information Center

Villasenor, John D.

1994-01-01

Describes a method for compressing tomographic images obtained using Positron Emission Tomography (PET) and Magnetic Resonance (MR) by applying transform compression using all available dimensions. This takes maximum advantage of redundancy of the data, allowing significant increases in compression efficiency and performance. (13 references) (KRN)

Resources for Improving Computerized Learning Environments.

ERIC Educational Resources Information Center

Yeaman, Andrew R. J.

1989-01-01

Presents an annotated review of human factors literature that discusses computerized environments. Topics discussed include the application of office automation practices to educational environments; video display terminal (VDT) workstations; health and safety hazards; planning educational facilities; ergonomics in computerized offices; and…

An overview of selected information storage and retrieval issues in computerized document processing

NASA Technical Reports Server (NTRS)

Dominick, Wayne D. (Editor); Ihebuzor, Valentine U.

1984-01-01

The rapid development of computerized information storage and retrieval techniques has introduced the possibility of extending the word processing concept to document processing. A major advantage of computerized document processing is the relief of the tedious task of manual editing and composition usually encountered by traditional publishers through the immense speed and storage capacity of computers. Furthermore, computerized document processing provides an author with centralized control, the lack of which is a handicap of the traditional publishing operation. A survey of some computerized document processing techniques is presented with emphasis on related information storage and retrieval issues. String matching algorithms are considered central to document information storage and retrieval and are also discussed.

Computerized Sociometric Assessment for Preschool Children

ERIC Educational Resources Information Center

Endedijk, Hinke M.; Cillessen, Antonius H. N.

2015-01-01

In preschool classes, sociometric peer ratings are used to measure children's peer relationships. The current study examined a computerized version of preschool sociometric ratings. The psychometric properties were compared of computerized sociometric ratings and traditional peer ratings for preschoolers. The distributions, inter-item…

The Mathematics of Four or More N-Localizers for Stereotactic Neurosurgery.

PubMed

Brown, Russell A

2015-10-13

The mathematics that were originally developed for the N-localizer apply to three N-localizers that produce three sets of fiducials in a tomographic image. Some applications of the N-localizer use four N-localizers that produce four sets of fiducials; however, the mathematics that apply to three sets of fiducials do not apply to four sets of fiducials. This article presents mathematics that apply to four or more sets of fiducials that all lie within one planar tomographic image. In addition, these mathematics are extended to apply to four or more fiducials that do not all lie within one planar tomographic image, as may be the case with magnetic resonance (MR) imaging where a volume is imaged instead of a series of planar tomographic images. Whether applied to a planar image or a volume image, the mathematics of four or more N-localizers provide a statistical measure of the quality of the image data that may be influenced by factors, such as the nonlinear distortion of MR images.

TomoBank: a tomographic data repository for computational x-ray science

DOE PAGES

De Carlo, Francesco; Gürsoy, Doğa; Ching, Daniel J.; ...

2018-02-08

There is a widening gap between the fast advancement of computational methods for tomographic reconstruction and their successful implementation in production software at various synchrotron facilities. This is due in part to the lack of readily available instrument datasets and phantoms representative of real materials for validation and comparison of new numerical methods. Recent advancements in detector technology made sub-second and multi-energy tomographic data collection possible [1], but also increased the demand to develop new reconstruction methods able to handle in-situ [2] and dynamic systems [3] that can be quickly incorporated in beamline production software [4]. The X-ray Tomography Datamore » Bank, tomoBank, provides a repository of experimental and simulated datasets with the aim to foster collaboration among computational scientists, beamline scientists, and experimentalists and to accelerate the development and implementation of tomographic reconstruction methods for synchrotron facility production software by providing easy access to challenging dataset and their descriptors.« less

High-resolution multimodal clinical multiphoton tomography of skin

NASA Astrophysics Data System (ADS)

König, Karsten

2011-03-01

This review focuses on multimodal multiphoton tomography based on near infrared femtosecond lasers. Clinical multiphoton tomographs for 3D high-resolution in vivo imaging have been placed into the market several years ago. The second generation of this Prism-Award winning High-Tech skin imaging tool (MPTflex) was introduced in 2010. The same year, the world's first clinical CARS studies have been performed with a hybrid multimodal multiphoton tomograph. In particular, non-fluorescent lipids and water as well as mitochondrial fluorescent NAD(P)H, fluorescent elastin, keratin, and melanin as well as SHG-active collagen has been imaged with submicron resolution in patients suffering from psoriasis. Further multimodal approaches include the combination of multiphoton tomographs with low-resolution wide-field systems such as ultrasound, optoacoustical, OCT, and dermoscopy systems. Multiphoton tomographs are currently employed in Australia, Japan, the US, and in several European countries for early diagnosis of skin cancer, optimization of treatment strategies, and cosmetic research including long-term testing of sunscreen nanoparticles as well as anti-aging products.

Tomographic findings of acute pulmonary toxoplasmosis in immunocompetent patients.

PubMed

de Souza Giassi, Karina; Costa, Andre Nathan; Apanavicius, Andre; Teixeira, Fernando Bin; Fernandes, Caio Julio Cesar; Helito, Alfredo Salim; Kairalla, Ronaldo Adib

2014-11-25

Toxoplasmosis is one of the most common human zoonosis, and is generally benign in most of the individuals. Pulmonary involvement is common in immunocompromised subjects, but very rare in immunocompetents and there are scarce reports of tomographic findings in the literature. The aim of the study is to describe three immunocompetent patients diagnosed with acute pulmonary toxoplasmosis and their respective thoracic tomographic findings. Acute toxoplasmosis was diagnosed according to the results of serological tests suggestive of recent primary infection and the absence of an alternative etiology. From 2009 to 2013, three patients were diagnosed with acute respiratory failure secondary to acute toxoplasmosis. The patients were two female and one male, and were 38, 56 and 36 years old. Similarly they presented a two-week febrile illness and progressive dyspnea before admission. Laboratory tests demonstrated lymphocytosis, slight changes in liver enzymes and high inflammatory markers. Tomographic findings were bilateral smooth septal and peribronchovascular thickening (100%), ground-glass opacities (100%), atelectasis (33%), random nodules (33%), lymph node enlargement (33%) and pleural effusion (66%). All the patients improved their symptoms after treatment, and complete resolution of tomographic findings were found in the followup. These cases provide a unique description of the presentation and evolution of pulmonary tomographic manifestations of toxoplasmosis in immunocompetent patients. Toxoplasma pneumonia manifests with fever, dyspnea and a non-productive cough that may result in respiratory failure. In animal models, changes were described as interstitial pneumonitis with focal infiltrates of neutrophils that can finally evolve into a pattern of diffuse alveolar damage with focal necrosis. The tomographic findings are characterized as ground glass opacities, smooth septal and marked peribronchovascular thickening; and may mimic pulmonary congestion, lymphangitis, atypical pneumonia and pneumocystosis. This is the largest series of CT findings of acute toxoplasmosis in immunocompetent hosts, and the diagnosis should be considered as patients that present with acute respiratory failure in the context of a subacute febrile illness with bilateral and diffuse interstitial infiltrates with marked peribronchovascular thickening. If promptly treated, pulmonary toxoplasmosis can result in complete clinical and radiological recovery in immunocompetent hosts.

Evaluation of computerized health management information system for primary health care in rural India

PubMed Central

2010-01-01

Background The Comprehensive Rural Health Services Project Ballabgarh, run by All India Institute of Medical Sciences (AIIMS), New Delhi has a computerized Health Management Information System (HMIS) since 1988. The HMIS at Ballabgarh has undergone evolution and is currently in its third version which uses generic and open source software. This study was conducted to evaluate the effectiveness of a computerized Health Management Information System in rural health system in India. Methods The data for evaluation were collected by in-depth interviews of the stakeholders i.e. program managers (authors) and health workers. Health Workers from AIIMS and Non-AIIMS Primary Health Centers were interviewed to compare the manual with computerized HMIS. A cost comparison between the two methods was carried out based on market costs. The resource utilization for both manual and computerized HMIS was identified based on workers' interviews. Results There have been no major hardware problems in use of computerized HMIS. More than 95% of data was found to be accurate. Health workers acknowledge the usefulness of HMIS in service delivery, data storage, generation of workplans and reports. For program managers, it provides a better tool for monitoring and supervision and data management. The initial cost incurred in computerization of two Primary Health Centers was estimated to be Indian National Rupee (INR) 1674,217 (USD 35,622). Equivalent annual incremental cost of capital items was estimated as INR 198,017 (USD 4213). The annual savings is around INR 894,283 (USD 11,924). Conclusion The major advantage of computerization has been in saving of time of health workers in record keeping and report generation. The initial capital costs of computerization can be recovered within two years of implementation if the system is fully operational. Computerization has enabled implementation of a good system for service delivery, monitoring and supervision. PMID:21078203

Computerized detection of breast lesions in multi-centre and multi-instrument DCE-MR data using 3D principal component maps and template matching

NASA Astrophysics Data System (ADS)

Ertas, Gokhan; Doran, Simon; Leach, Martin O.

2011-12-01

In this study, we introduce a novel, robust and accurate computerized algorithm based on volumetric principal component maps and template matching that facilitates lesion detection on dynamic contrast-enhanced MR. The study dataset comprises 24 204 contrast-enhanced breast MR images corresponding to 4034 axial slices from 47 women in the UK multi-centre study of MRI screening for breast cancer and categorized as high risk. The scans analysed here were performed on six different models of scanner from three commercial vendors, sited in 13 clinics around the UK. 1952 slices from this dataset, containing 15 benign and 13 malignant lesions, were used for training. The remaining 2082 slices, with 14 benign and 12 malignant lesions, were used for test purposes. To prevent false positives being detected from other tissues and regions of the body, breast volumes are segmented from pre-contrast images using a fast semi-automated algorithm. Principal component analysis is applied to the centred intensity vectors formed from the dynamic contrast-enhanced T1-weighted images of the segmented breasts, followed by automatic thresholding to eliminate fatty tissues and slowly enhancing normal parenchyma and a convolution and filtering process to minimize artefacts from moderately enhanced normal parenchyma and blood vessels. Finally, suspicious lesions are identified through a volumetric sixfold neighbourhood connectivity search and calculation of two morphological features: volume and volumetric eccentricity, to exclude highly enhanced blood vessels, nipples and normal parenchyma and to localize lesions. This provides satisfactory lesion localization. For a detection sensitivity of 100%, the overall false-positive detection rate of the system is 1.02/lesion, 1.17/case and 0.08/slice, comparing favourably with previous studies. This approach may facilitate detection of lesions in multi-centre and multi-instrument dynamic contrast-enhanced breast MR data.

Clamshell tomograph

DOEpatents

Derenzo, Stephen E.; Budinger, Thomas F.

1984-01-01

In brief, the invention is a tomograph modified to be in a clamshell configuration so that the ring or rings may be moved to multiple sampling positions. The tomograph includes an array of detectors arranged in successive adjacent relative locations along a closed curve in a first position in a selected plane, and means for securing the detectors in the relative locations in a first sampling position. The securing means is movable in the plane in two sections and pivotable at one p The U.S. Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the U.S. Department of Energy and the University of California.

Center-of-Mass Tomography and Wigner Function for Multimode Photon States

NASA Astrophysics Data System (ADS)

Dudinets, Ivan V.; Man'ko, Vladimir I.

2018-06-01

Tomographic probability representation of multimode electromagnetic field states in the scheme of center-of-mass tomography is reviewed. Both connection of the field state Wigner function and observable Weyl symbols with the center-of-mass tomograms as well as connection of the Grönewold kernel with the center-of-mass tomographic kernel determining the noncommutative product of the tomograms are obtained. The dual center-of-mass tomogram of the photon states are constructed and the dual tomographic kernel is obtained. The models of other generalized center-of-mass tomographies are discussed. Example of two-mode even and odd Schrödinger cat states is presented in details.

78 FR 17940 - Certain Computerized Orthopedic Surgical Devices, Software, Implants, and Components Thereof...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-25

..., Software, Implants, and Components Thereof; Notice of Receipt of Complaint; Solicitation of Comments... Certain Computerized Orthopedic Surgical Devices, Software, Implants, and Components Thereof, DN 2945; the... importation of certain computerized orthopedic surgical devices, software, implants, and components thereof...

Designing a Computerized Presentation Center.

ERIC Educational Resources Information Center

Christopher, Doris A.

1995-01-01

The Office Systems and Business Education Department at California State University (Los Angeles) developed a computerized presentation center, with multimedia classrooms and a multipurpose room, where students learn computerized presentation design skills, faculty can develop materials for class, and local business can do videoconferencing and…

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

Bargellini, Irene, E-mail: irenebargellini@hotmail.com; Turini, Francesca; Bozzi, Elena

To assess feasibility of proper hepatic artery catheterization using a 3D model obtained from preprocedural computed tomographic angiography (CTA), fused with real-time fluoroscopy, during transarterial chemoembolization of hepatocellular carcinoma. Twenty consecutive cirrhotic patients with hepatocellular carcinoma undergoing transarterial chemoembolization were prospectively enrolled onto the study. The early arterial phase axial images of the preprocedural CTA were postprocessed on an independent workstation connected to the angiographic system (Innova 4100; GE Healthcare, Milwaukee, WI), obtaining a 3D volume rendering image (VR) that included abdominal aorta, splanchnic arteries, and first and second lumbar vertebrae. The VR image was manually registered to the real-timemore » X-ray fluoroscopy, with the lumbar spine used as the reference. The VR image was then used as guidance to selectively catheterize the proper hepatic artery. The procedure was considered successful when performed with no need for intraarterial contrast injections or angiographic acquisitions. The procedure was successful in 19 (95 %) of 20 patients. In one patient, celiac trunk angiography was required for the presence of a significant ostial stenosis that was underestimated at computed tomography. Time for image reconstruction and registration was <10 min in all cases. The use of preprocedural CTA model with fluoroscopy enables confident and direct catheterization of the proper hepatic artery with no need for preliminary celiac trunk angiography, thus reducing radiation exposure and contrast media administration.« less

Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors.

PubMed

Bhatti, Aftab A; Chugtai, Aamir; Haslam, Philip; Talbot, David; Rix, David A; Soomro, Naeem A

2005-11-01

To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors. Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery. CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively. Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.

Toxoplasma encephalitis in Haitian adults with acquired immunodeficiency syndrome: a clinical-pathologic-CT correlation

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

Post, M.J.D.; Chan, J.C.; Hensley, G.T.

1983-05-01

The clinical data, histologic findings, and computed tomographic (CT) abnormalities in eight adult Haitians with toxoplasma encephalitis were analyzed retrospectively. Diagnosis was established by identification of Toxoplasma gondii on autopsy in five and brain biopsy in three specimens and subsequently confirmed by the immunoperoxidase method. All these patiens, six of whom had been in the United States for 24 months or less, had severe idiopathic immunodeficiency syndrome. All were lymphopenic and six were on treatment for tuberculosis when the toxoplasma encephalitis developed. All patients were studied with CT when they developed an altered mental status and fever associated with seizuresmore » and/or focal neurologic deficits. Scans before treatment showed multiple intraparenchymal lesions in seven and a single lesion in the thalamus in one. Ring and/or nodular enhancement of the lesions was found in six and hypodense areas in two. Progressions of abnormalities occurred on serial studies. These CT findings that were best shown on axial and coronal thin-section double-dose contrast studies were useful but not diagnostically pathognomonic. In patients with similar clinical presentation CT is recommended to identify focal areas of involvement and to guide brain biopsy or excision so that prompt medical thereapy of this often lethal infection can be instituted.« less

Incentives and Barriers That Influence Clinical Computerization in Hong Kong: A Population-based Physician Survey

PubMed Central

Leung, Gabriel M.; Yu, Philip L. H.; Wong, Irene O. L.; Johnston, Janice M.; Tin, Keith Y. K.

2003-01-01

Objective: Given the slow adoption of medical informatics in Hong Kong and Asia, we sought to understand the contributory barriers and potential incentives associated with information technology implementation. Design and Measurements: A representative sample of 949 doctors (response rate = 77.0%) was asked through a postal survey to rank a list of nine barriers associated with clinical computerization according to self-perceived importance. They ranked seven incentives or catalysts that may influence computerization. We generated mean rank scores and used multidimensional preference analysis to explore key explanatory dimensions of these variables. A hierarchical cluster analysis was performed to identify homogenous subgroups of respondents. We further determined the relationships between the sets of barriers and incentives/catalysts collectively using canonical correlation. Results: Time costs, lack of technical support and large capital investments were the biggest barriers to computerization, whereas improved office efficiency and better-quality care were ranked highest as potential incentives to computerize. Cost vs. noncost, physician-related vs. patient-related, and monetary vs. nonmonetary factors were the key dimensions explaining the barrier variables. Similarly, within-practice vs external and “push” vs “pull” factors accounted for the incentive variables. Four clusters were identified for barriers and three for incentives/catalysts. Canonical correlation revealed that respondents who were concerned with the costs of computerization also perceived financial incentives and government regulation to be important incentives/catalysts toward computerization. Those who found the potential interference with communication important also believed that the promise of improved care from computerization to be a significant incentive. Conclusion: This study provided evidence regarding common barriers associated with clinical computerization. Our findings also identified possible incentive strategies that may be employed to accelerate uptake of computer systems. PMID:12595409

Can computerized tomography accurately stage childhood renal tumors?

PubMed

Abdelhalim, Ahmed; Helmy, Tamer E; Harraz, Ahmed M; Abou-El-Ghar, Mohamed E; Dawaba, Mohamed E; Hafez, Ashraf T

2014-07-01

Staging of childhood renal tumors is crucial for treatment planning and outcome prediction. We sought to identify whether computerized tomography could accurately predict the local stage of childhood renal tumors. We retrospectively reviewed our database for patients diagnosed with childhood renal tumors and treated surgically between 1990 and 2013. Inability to retrieve preoperative computerized tomography, intraoperative tumor spillage and nonWilms childhood renal tumors were exclusion criteria. Local computerized tomography stage was assigned by a single experienced pediatric radiologist blinded to the pathological stage, using a consensus similar to the Children's Oncology Group Wilms tumor staging system. Tumors were stratified into up-front surgery and preoperative chemotherapy groups. The radiological stage of each tumor was compared to the pathological stage. A total of 189 tumors in 179 patients met inclusion criteria. Computerized tomography staging matched pathological staging in 68% of up-front surgery (70 of 103), 31.8% of pre-chemotherapy (21 of 66) and 48.8% of post-chemotherapy scans (42 of 86). Computerized tomography over staged 21.4%, 65.2% and 46.5% of tumors in the up-front surgery, pre-chemotherapy and post-chemotherapy scans, respectively, and under staged 10.7%, 3% and 4.7%. Computerized tomography staging was more accurate in tumors managed by up-front surgery (p <0.001) and those without extracapsular extension (p <0.001). The validity of computerized tomography staging of childhood renal tumors remains doubtful. This staging is more accurate for tumors treated with up-front surgery and those without extracapsular extension. Preoperative computerized tomography can help to exclude capsular breach. Treatment strategy should be based on surgical and pathological staging to avoid the hazards of inaccurate staging. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Tracking tracer breakthrough in the hyporheic zone using time‐lapse DC resistivity, Crabby Creek, Pennsylvania

USGS Publications Warehouse

Nyquist, Jonathan E.; Toran, Laura; Fang, Allison C.; Ryan, Robert J.; Rosenberry, Donald O.

2010-01-01

Characterization of the hyporheic zone is of critical importance for understanding stream ecology, contaminant transport, and groundwater‐surface water interaction. A salt water tracer test was used to probe the hyporheic zone of a recently re‐engineered portion of Crabby Creek, a stream located near Philadelphia, PA. The tracer solution was tracked through a 13.5 meter segment of the stream using both a network of 25 wells sampled every 5–15 minutes and time‐lapse electrical resistivity tomographs collected every 11 minutes for six hours, with additional tomographs collected every 100 minutes for an additional 16 hours. The comparison of tracer monitoring methods is of keen interest because tracer tests are one of the few techniques available for characterizing this dynamic zone, and logistically it is far easier to collect resistivity tomographs than to install and monitor a dense network of wells. Our results show that resistivity monitoring captured the essential shape of the breakthrough curve and may indicate portions of the stream where the tracer lingered in the hyporheic zone. Time‐lapse resistivity measurements, however, represent time averages over the period required to collect a tomographic data set, and spatial averages over a volume larger than captured by a well sample. Smoothing by the resistivity data inversion algorithm further blurs the resulting tomograph; consequently resistivity monitoring underestimates the degree of fine‐scale heterogeneity in the hyporheic zone.

Rapid tomographic reconstruction based on machine learning for time-resolved combustion diagnostics

NASA Astrophysics Data System (ADS)

Yu, Tao; Cai, Weiwei; Liu, Yingzheng

2018-04-01

Optical tomography has attracted surged research efforts recently due to the progress in both the imaging concepts and the sensor and laser technologies. The high spatial and temporal resolutions achievable by these methods provide unprecedented opportunity for diagnosis of complicated turbulent combustion. However, due to the high data throughput and the inefficiency of the prevailing iterative methods, the tomographic reconstructions which are typically conducted off-line are computationally formidable. In this work, we propose an efficient inversion method based on a machine learning algorithm, which can extract useful information from the previous reconstructions and build efficient neural networks to serve as a surrogate model to rapidly predict the reconstructions. Extreme learning machine is cited here as an example for demonstrative purpose simply due to its ease of implementation, fast learning speed, and good generalization performance. Extensive numerical studies were performed, and the results show that the new method can dramatically reduce the computational time compared with the classical iterative methods. This technique is expected to be an alternative to existing methods when sufficient training data are available. Although this work is discussed under the context of tomographic absorption spectroscopy, we expect it to be useful also to other high speed tomographic modalities such as volumetric laser-induced fluorescence and tomographic laser-induced incandescence which have been demonstrated for combustion diagnostics.

Rapid tomographic reconstruction based on machine learning for time-resolved combustion diagnostics.

PubMed

Yu, Tao; Cai, Weiwei; Liu, Yingzheng

2018-04-01

Optical tomography has attracted surged research efforts recently due to the progress in both the imaging concepts and the sensor and laser technologies. The high spatial and temporal resolutions achievable by these methods provide unprecedented opportunity for diagnosis of complicated turbulent combustion. However, due to the high data throughput and the inefficiency of the prevailing iterative methods, the tomographic reconstructions which are typically conducted off-line are computationally formidable. In this work, we propose an efficient inversion method based on a machine learning algorithm, which can extract useful information from the previous reconstructions and build efficient neural networks to serve as a surrogate model to rapidly predict the reconstructions. Extreme learning machine is cited here as an example for demonstrative purpose simply due to its ease of implementation, fast learning speed, and good generalization performance. Extensive numerical studies were performed, and the results show that the new method can dramatically reduce the computational time compared with the classical iterative methods. This technique is expected to be an alternative to existing methods when sufficient training data are available. Although this work is discussed under the context of tomographic absorption spectroscopy, we expect it to be useful also to other high speed tomographic modalities such as volumetric laser-induced fluorescence and tomographic laser-induced incandescence which have been demonstrated for combustion diagnostics.

Estimating crustal heterogeneity from double-difference tomography

USGS Publications Warehouse

Got, J.-L.; Monteiller, V.; Virieux, J.; Okubo, P.

2006-01-01

Seismic velocity parameters in limited, but heterogeneous volumes can be inferred using a double-difference tomographic algorithm, but to obtain meaningful results accuracy must be maintained at every step of the computation. MONTEILLER et al. (2005) have devised a double-difference tomographic algorithm that takes full advantage of the accuracy of cross-spectral time-delays of large correlated event sets. This algorithm performs an accurate computation of theoretical travel-time delays in heterogeneous media and applies a suitable inversion scheme based on optimization theory. When applied to Kilauea Volcano, in Hawaii, the double-difference tomography approach shows significant and coherent changes to the velocity model in the well-resolved volumes beneath the Kilauea caldera and the upper east rift. In this paper, we first compare the results obtained using MONTEILLER et al.'s algorithm with those obtained using the classic travel-time tomographic approach. Then, we evaluated the effect of using data series of different accuracies, such as handpicked arrival-time differences ("picking differences"), on the results produced by double-difference tomographic algorithms. We show that picking differences have a non-Gaussian probability density function (pdf). Using a hyperbolic secant pdf instead of a Gaussian pdf allows improvement of the double-difference tomographic result when using picking difference data. We completed our study by investigating the use of spatially discontinuous time-delay data. ?? Birkha??user Verlag, Basel, 2006.

Compressive sensing reconstruction of 3D wet refractivity based on GNSS and InSAR observations

NASA Astrophysics Data System (ADS)

Heublein, Marion; Alshawaf, Fadwa; Erdnüß, Bastian; Zhu, Xiao Xiang; Hinz, Stefan

2018-06-01

In this work, the reconstruction quality of an approach for neutrospheric water vapor tomography based on Slant Wet Delays (SWDs) obtained from Global Navigation Satellite Systems (GNSS) and Interferometric Synthetic Aperture Radar (InSAR) is investigated. The novelties of this approach are (1) the use of both absolute GNSS and absolute InSAR SWDs for tomography and (2) the solution of the tomographic system by means of compressive sensing (CS). The tomographic reconstruction is performed based on (i) a synthetic SWD dataset generated using wet refractivity information from the Weather Research and Forecasting (WRF) model and (ii) a real dataset using GNSS and InSAR SWDs. Thus, the validation of the achieved results focuses (i) on a comparison of the refractivity estimates with the input WRF refractivities and (ii) on radiosonde profiles. In case of the synthetic dataset, the results show that the CS approach yields a more accurate and more precise solution than least squares (LSQ). In addition, the benefit of adding synthetic InSAR SWDs into the tomographic system is analyzed. When applying CS, adding synthetic InSAR SWDs into the tomographic system improves the solution both in magnitude and in scattering. When solving the tomographic system by means of LSQ, no clear behavior is observed. In case of the real dataset, the estimated refractivities of both methodologies show a consistent behavior although the LSQ and CS solution strategies differ.

Investigating Gravity Waves in Polar Mesospheric Clouds Using Tomographic Reconstructions of AIM Satellite Imagery

NASA Astrophysics Data System (ADS)

Hart, V. P.; Taylor, M. J.; Doyle, T. E.; Zhao, Y.; Pautet, P.-D.; Carruth, B. L.; Rusch, D. W.; Russell, J. M.

2018-01-01

This research presents the first application of tomographic techniques for investigating gravity wave structures in polar mesospheric clouds (PMCs) imaged by the Cloud Imaging and Particle Size instrument on the NASA AIM satellite. Albedo data comprising consecutive PMC scenes were used to tomographically reconstruct a 3-D layer using the Partially Constrained Algebraic Reconstruction Technique algorithm and a previously developed "fanning" technique. For this pilot study, a large region (760 × 148 km) of the PMC layer (altitude 83 km) was sampled with a 2 km horizontal resolution, and an intensity weighted centroid technique was developed to create novel 2-D surface maps, characterizing the individual gravity waves as well as their altitude variability. Spectral analysis of seven selected wave events observed during the Northern Hemisphere 2007 PMC season exhibited dominant horizontal wavelengths of 60-90 km, consistent with previous studies. These tomographic analyses have enabled a broad range of new investigations. For example, a clear spatial anticorrelation was observed between the PMC albedo and wave-induced altitude changes, with higher-albedo structures aligning well with wave troughs, while low-intensity regions aligned with wave crests. This result appears to be consistent with current theories of PMC development in the mesopause region. This new tomographic imaging technique also provides valuable wave amplitude information enabling further mesospheric gravity wave investigations, including quantitative analysis of their hemispheric and interannual characteristics and variations.

15 CFR 950.9 - Computerized Environmental Data and Information Retrieval Service.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Information Retrieval Service. 950.9 Section 950.9 Commerce and Foreign Trade Regulations Relating to Commerce... Computerized Environmental Data and Information Retrieval Service. The Environmental Data Index (ENDEX... computerized, information retrieval service provides a parallel subject-author-abstract referral service. A...

15 CFR 950.9 - Computerized Environmental Data and Information Retrieval Service.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Information Retrieval Service. 950.9 Section 950.9 Commerce and Foreign Trade Regulations Relating to Commerce... Computerized Environmental Data and Information Retrieval Service. The Environmental Data Index (ENDEX... computerized, information retrieval service provides a parallel subject-author-abstract referral service. A...

15 CFR 950.9 - Computerized Environmental Data and Information Retrieval Service.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Information Retrieval Service. 950.9 Section 950.9 Commerce and Foreign Trade Regulations Relating to Commerce... Computerized Environmental Data and Information Retrieval Service. The Environmental Data Index (ENDEX... computerized, information retrieval service provides a parallel subject-author-abstract referral service. A...

15 CFR 950.9 - Computerized Environmental Data and Information Retrieval Service.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Information Retrieval Service. 950.9 Section 950.9 Commerce and Foreign Trade Regulations Relating to Commerce... Computerized Environmental Data and Information Retrieval Service. The Environmental Data Index (ENDEX... computerized, information retrieval service provides a parallel subject-author-abstract referral service. A...

15 CFR 950.9 - Computerized Environmental Data and Information Retrieval Service.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Information Retrieval Service. 950.9 Section 950.9 Commerce and Foreign Trade Regulations Relating to Commerce... Computerized Environmental Data and Information Retrieval Service. The Environmental Data Index (ENDEX... computerized, information retrieval service provides a parallel subject-author-abstract referral service. A...

Innovations in Computerized Assessment.

ERIC Educational Resources Information Center

Drasgow, Fritz, Ed.; Olson-Buchanan, Julie B., Ed.

Chapters in this book present the challenges and dilemmas faced by researchers as they created new computerized assessments, focusing on issues addressed in developing, scoring, and administering the assessments. Chapters are: (1) "Beyond Bells and Whistles; An Introduction to Computerized Assessment" (Julie B. Olson-Buchanan and Fritz Drasgow);…

Advanced Composition and the Computerized Library.

ERIC Educational Resources Information Center

Hult, Christine

1989-01-01

Discusses four kinds of computerized access tools: online catalogs; computerized reference; online database searching; and compact disks and read only memory (CD-ROM). Examines how these technologies are changing research. Suggests how research instruction in advanced writing courses can be refocused to include the new technologies. (RS)

Validation of a Self-Administered Computerized System to Detect Cognitive Impairment in Older Adults

PubMed Central

Brinkman, Samuel D.; Reese, Robert J.; Norsworthy, Larry A.; Dellaria, Donna K.; Kinkade, Jacob W.; Benge, Jared; Brown, Kimberly; Ratka, Anna; Simpkins, James W.

2015-01-01

There is increasing interest in the development of economical and accurate approaches to identifying persons in the community who have mild, undetected cognitive impairments. Computerized assessment systems have been suggested as a viable approach to identifying these persons. The validity of a computerized assessment system for identification of memory and executive deficits in older individuals was evaluated in the current study. Volunteers (N = 235) completed a 3-hr battery of neuropsychological tests and a computerized cognitive assessment system. Participants were classified as impaired (n = 78) or unimpaired (n = 157) on the basis of the Mini Mental State Exam, Wechsler Memory Scale-III and the Trail Making Test (TMT), Part B. All six variables (three memory variables and three executive variables) derived from the computerized assessment differed significantly between groups in the expected direction. There was also evidence of temporal stability and concurrent validity. Application of computerized assessment systems for clinical practice and for identification of research participants is discussed in this article. PMID:25332303

Computerized neurocognitive testing in the management of sport-related concussion: an update.

PubMed

Resch, Jacob E; McCrea, Michael A; Cullum, C Munro

2013-12-01

Since the late nineties, computerized neurocognitive testing has become a central component of sport-related concussion (SRC) management at all levels of sport. In 2005, a review of the available evidence on the psychometric properties of four computerized neuropsychological test batteries concluded that the tests did not possess the necessary criteria to warrant clinical application. Since the publication of that review, several more computerized neurocognitive tests have entered the market place. The purpose of this review is to summarize the body of published studies on psychometric properties and clinical utility of computerized neurocognitive tests available for use in the assessment of SRC. A review of the literature from 2005 to 2013 was conducted to gather evidence of test-retest reliability and clinical validity of these instruments. Reviewed articles included both prospective and retrospective studies of primarily sport-based adult and pediatric samples. Summaries are provided regarding the available evidence of reliability and validity for the most commonly used computerized neurocognitive tests in sports settings.

Association of Inter-arm Blood Pressure Difference with Asymptomatic Intracranial and Extracranial Arterial Stenosis in Hypertension Patients

PubMed Central

Wang, Yan; Zhang, Jin; Qian, Yuesheng; Tang, Xiaofeng; Ling, Huawei; Chen, Kemin; Li, Yan; Gao, Pingjin; Zhu, Dingliang

2016-01-01

Inter-arm blood pressure (BP) difference has been associated with ischemic stroke. Local atherosclerosis of stroke differ among vulnerable individuals, whereas intracranial arterial stenosis (ICAS) is more frequently affected Asians, and extracranial arterial stenosis (ECAS) is more prevalent among whites. We hereby sought to explore the association of inter-arm BP difference with ICAS and ECAS in stroke-free hypertensive patients in Chinese population. All the 885 subjects were evaluated of ICAS and ECAS through computerized tomographic angiography. Both arm BP was measured simultaneously by Vascular Profiler-1000 device. In the continuous study, ICAS was significantly associated with age, male, average brachial SBP, diabetes, anti-hypertensive treatment and inter-arm DBP difference. ECAS was associated with age, inter-arm SBP and LDL. In the categorical study, subjects with the top quartile of inter-arm DBP difference (≥4 mmHg) showed significantly higher risk of ICAS (OR = 2.109; 95% CI, 1.24–3.587). And the participants with the top quartile of inter-arm SBP difference (≥6 mmHg) showed significantly higher risk of ECAS (OR = 2.288; 95% CI, 1.309–3.998). In conclusion, we reported a diverse association of inter-arm SBP/DBP difference with the ICAS/ECAS. Inter-arm DBP difference might be the early symbol of ICAS in Chinese population, which need further verification in long-term cohort study. PMID:27412818

Following Surgically Assisted Rapid Palatal Expansion, Do Tooth-Borne or Bone-Borne Appliances Provide More Skeletal Expansion and Dental Expansion?

PubMed

Hamedi-Sangsari, Adrien; Chinipardaz, Zahra; Carrasco, Lee

2017-10-01

The aim of this study was to compare outcome measurements of skeletal and dental expansion with bone-borne (BB) versus tooth-borne (TB) appliances after surgically assisted rapid palatal expansion (SARPE). This study was performed to provide quantitative measurements that will help the oral surgeon and orthodontist in selecting the appliance with, on average, the greatest amount of skeletal expansion and the least amount of dental expansion. A computerized database search was performed using PubMed, EBSCO, Cochrane, Scopus, Web of Science, and Google Scholar on publications in reputable oral surgery and orthodontic journals. A systematic review and meta-analysis was completed with the predictor variable of expansion appliance (TB vs BB) and outcome measurement of expansion (in millimeters). Of 487 articles retrieved from the 6 databases, 5 articles were included, 4 with cone-beam computed tomographic (CBCT) data and 1 with non-CBCT 3-dimensional cast data. There was a significant difference in skeletal expansion (standardized mean difference [SMD], 0.92; 95% confidence interval [CI], 0.54-1.30; P < .001) in favor of BB rather than TB appliances. However, there was no significant difference in dental expansion (SMD, 0.05; 95% CI, -0.24 to 0.34; P = .03). According to the literature, to achieve more effective skeletal expansion and minimize dental expansion after SARPE, a BB appliance should be favored. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Cost-effectiveness of Colorectal Cancer Screening and Treatment Methods: Mapping of Systematic Reviews.

PubMed

Abdolahi, Hossein Mashhadi; Asiabar, Ali Sarabi; Azami-Aghdash, Saber; Pournaghi-Azar, Fatemeh; Rezapour, Aziz

2018-01-01

Due to extensive literature on colorectal cancer and their heterogeneous results, this study aimed to summarize the systematic reviews which review the cost-effectiveness studies on different aspects of colorectal cancer. The required data were collected by searching the following key words according to MeSH: "colorectal cancer," "colorectal oncology," "colorectal carcinoma," "colorectal neoplasm," "colorectal tumors," "cost-effectiveness," "systematic review," and "meta-analysis." The following databases were searched: PubMed, Cochrane, Google Scholar, and Scopus. Two reviewers evaluated the articles according to the checklist of "assessment of multiple systematic reviews" (AMSTAR) tool. Finally, eight systematic reviews were included in the study. The Drummond checklist was mostly used for assessing the quality of the articles. The main perspective was related to the payer and the least was relevant to the social. The majority of the cases referred to sensitivity analysis (in 76% of the cases) and the lowest point also was allocated to discounting (in 37% of cases). The Markov model was used most widely in the studies. Treatment methods examined in the studies were not cost-effective in comparison with the studied units. Among the screening methods, computerized tomographic colonography and fecal DNA were cost-effective. The average score of the articles' qualities was high (9.8 out of 11). The community perspective should be taken into consideration at large in the studies. It is necessary to pay more attention to discounting subject in studies. More frequent application of the Markov model is recommended.

What Do Physicians Know About Normal Pressure Hydrocephalus and When Did They Know It? A Survey of 284 Physicians

PubMed Central

Conn, Harold O.; Lobo, Francis M.

2008-01-01

Normal pressure hydrocephalus (NPH) is a relatively new neurologic disorder first described by Salamon Hakim of Bogotá, Colombia, in 1965. NPH is characterized by three symptoms — impaired gait, incontinence and dementia — and an anatomic abnormality, i.e., enlargement of the cerebral ventricles, which can be seen on computerized tomographic or magnetic resonance imaging. Surprisingly, the intracranial pressure is normal. The first author of this article, a Yale Medical School faculty member, developed NPH over the decade from 1992 to 2002, during which it was erroneously diagnosed as cerebral atrophy and/or Parkinson’s disease. On recognizing the lack of awareness of NPH by physicians, he initiated a survey to explore this problem. He interviewed 166 practicing physicians who graduated from 50 American and 33 foreign medical schools, using a one-page, 10-point questionnaire (Part I). Almost one-third of the physicians had never heard of NPH. One-fifth had learned of NPH in medical school, and about half learned of it after medical school. Because there were insufficient physicians surveyed from 1986 to 2005, we recruited 118 additional physicians from the 20 Yale Medical School graduating classes from 1986 through 2005 (Part II). Two-thirds of them had learned of NPH in medical school, and one-fourth during residency and fellowship. Seven percent had never heard of NPH. The significance of these studies is discussed. PMID:18604308

Retinoic acid-induced alveolar cellular growth does not improve function after right pneumonectomy.

PubMed

Dane, D Merrill; Yan, Xiao; Tamhane, Rahul M; Johnson, Robert L; Estrera, Aaron S; Hogg, Deborah C; Hogg, Richard T; Hsia, Connie C W

2004-03-01

To determine whether all-trans retinoic acid (RA) treatment enhances lung function during compensatory lung growth in fully mature animals, adult male dogs (n = 4) received 2 mg x kg(-1) x day(-1) po RA 4 days/wk beginning the day after right pneumonectomy (R-PNX, 55-58% resection). Litter-matched male R-PNX controls (n = 4) received placebo. After 3 mo, transpulmonary pressure (TPP)-lung volume relationship, diffusing capacities for carbon monoxide and nitric oxide, cardiac output, and septal volume (V(tiss-RB)) were measured under anesthesia by a rebreathing technique at two lung volumes. Lung air and tissue volumes (V(air-CT) and V(tiss-CT)) were also measured from high-resolution computerized tomographic (CT) scans at a constant TPP. In RA-treated dogs compared with controls, TPP-lung volume relationships were similar. Diffusing capacities for carbon monoxide and nitric oxide were significantly impaired at a lower lung volume but similar at a high lung volume. Whereas V(tiss-RB) was significantly lower at both lung volumes in RA-treated animals, V(air-CT) and V(tiss-CT) were not different between groups; results suggest uneven distribution of ventilation consistent with distortion of alveolar geometry and/or altered small airway function induced by RA. We conclude that RA does not improve resting pulmonary function during the early months after R-PNX despite histological evidence of its action in enhancing alveolar cellular growth in the remaining lung.

Application Of Iterative Reconstruction Techniques To Conventional Circular Tomography

NASA Astrophysics Data System (ADS)

Ghosh Roy, D. N.; Kruger, R. A.; Yih, B. C.; Del Rio, S. P.; Power, R. L.

1985-06-01

Two "point-by-point" iteration procedures, namely, Iterative Least Square Technique (ILST) and Simultaneous Iterative Reconstructive Technique (SIRT) were applied to classical circular tomographic reconstruction. The technique of tomosynthetic DSA was used in forming the tomographic images. Reconstructions of a dog's renal and neck anatomy are presented.

21 CFR 892.1740 - Tomographic x-ray system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tomographic x-ray system. 892.1740 Section 892.1740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... This generic type of device may include signal analysis and display equipment, patient and equipment...

21 CFR 892.1740 - Tomographic x-ray system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tomographic x-ray system. 892.1740 Section 892.1740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... This generic type of device may include signal analysis and display equipment, patient and equipment...

21 CFR 892.1740 - Tomographic x-ray system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tomographic x-ray system. 892.1740 Section 892.1740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... This generic type of device may include signal analysis and display equipment, patient and equipment...

21 CFR 892.1740 - Tomographic x-ray system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tomographic x-ray system. 892.1740 Section 892.1740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... This generic type of device may include signal analysis and display equipment, patient and equipment...

21 CFR 892.1740 - Tomographic x-ray system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tomographic x-ray system. 892.1740 Section 892.1740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED.... This generic type of device may include signal analysis and display equipment, patient and equipment...

Computerized Numerical Control Curriculum Guide.

ERIC Educational Resources Information Center

Reneau, Fred; And Others

This guide is intended for use in a course in programming and operating a computerized numerical control system. Addressed in the course are various aspects of programming and planning, setting up, and operating machines with computerized numerical control, including selecting manual or computer-assigned programs and matching them with…

Utility of three-dimensional and multiplanar reformatted computed tomography for evaluation of pediatric congenital spine abnormalities.

PubMed

Newton, Peter O; Hahn, Gregory W; Fricka, Kevin B; Wenger, Dennis R

2002-04-15

A retrospective radiographic review of 31 patients with congenital spine abnormalities who underwent conventional radiography and advanced imaging studies was conducted. To analyze the utility of three-dimensional computed tomography with multiplanar reformatted images for congenital spine anomalies, as compared with plain radiographs and axial two-dimensional computed tomography imaging. Conventional radiographic imaging for congenital spine disorders often are difficult to interpret because of the patient's small size, the complexity of the disorder, a deformity not in the plane of the radiographs, superimposed structures, and difficulty in forming a mental three-dimensional image. Multiplanar reformatted and three-dimensional computed tomographic imaging offers many potential advantages for defining congenital spine anomalies including visualization of the deformity in any plane, from any angle, with the overlying structures subtracted. The imaging studies of patients who had undergone a three-dimensional computed tomography for congenital deformities of the spine between 1992 and 1998 were reviewed (31 cases). All plain radiographs and axial two-dimensional computed tomography images performed before the three-dimensional computed tomography were reviewed and the findings documented. This was repeated for the three-dimensional reconstructions and, when available, the multiplanar reformatted images (15 cases). In each case, the utility of the advanced imaging was graded as one of the following: Grade A (substantial new information obtained), Grade B (confirmatory with improved visualization and understanding of the deformity), and Grade C (no added useful information obtained). In 17 of 31 cases, the multiplanar reformatted and three-dimensional images allowed identification of unrecognized malformations. In nine additional cases, the advanced imaging was helpful in better visualizing and understanding previously identified deformities. In five cases, no new information was gained. The standard and curved multiplanar reformatted images were best for defining the occiput-C1-C2 anatomy and the extent of segmentation defects. The curved multiplanar reformatted images were especially helpful in keeping the spine from "coming in" and "going out" of the plane of the image when there was significant spine deformity in the sagittal or coronal plane. The three-dimensional reconstructions proved valuable in defining failures of formation. Advanced computed tomography imaging (three-dimensional computed tomography and curved/standard multiplanar reformatted images) allows better definition of congenital spine anomalies. More than 50% of the cases showed additional abnormalities not appreciated on plain radiographs or axial two-dimensional computed tomography images. Curved multiplanar reformatted images allowed imaging in the coronal and sagittal planes of the entire deformity.

An Application of the Rasch Model to Computerized Adaptive Testing.

ERIC Educational Resources Information Center

Wisniewski, Dennis R.

Three questions concerning the Binary Search Method (BSM) of computerized adaptive testing were studied: (1) whether it provided a reliable and valid estimation of examinee ability; (2) its effect on examinee attitudes toward computerized adaptive testing and conventional paper-and-pencil testing; and (3) the relationship between item response…

The Reality, Direction, and Future of Computerized Publications

ERIC Educational Resources Information Center

Levenstein, Nicholas

2012-01-01

Sharing information in digital form by using a computer is a growing phenomenon. Many universities are making their applications available on computer. More than one hundred and thirty-six universities have developed computerized applications on their own or through a commercial vendor. Universities developed computerized applications in order to…

Evaluating a Computerized Aid for Conducting a Cognitive Task Analysis

DTIC Science & Technology

2000-01-01

in conducting a cognitive task analysis . The conduct of a cognitive task analysis is costly and labor intensive. As a result, a few computerized aids...evaluation of a computerized aid, specifically CAT-HCI (Cognitive Analysis Tool - Human Computer Interface), for the conduct of a detailed cognitive task analysis . A

Computerized Classification Testing with the Rasch Model

ERIC Educational Resources Information Center

Eggen, Theo J. H. M.

2011-01-01

If classification in a limited number of categories is the purpose of testing, computerized adaptive tests (CATs) with algorithms based on sequential statistical testing perform better than estimation-based CATs (e.g., Eggen & Straetmans, 2000). In these computerized classification tests (CCTs), the Sequential Probability Ratio Test (SPRT) (Wald,…

Severity of Organized Item Theft in Computerized Adaptive Testing: A Simulation Study

ERIC Educational Resources Information Center

Yi, Qing; Zhang, Jinming; Chang, Hua-Hua

2008-01-01

Criteria had been proposed for assessing the severity of possible test security violations for computerized tests with high-stakes outcomes. However, these criteria resulted from theoretical derivations that assumed uniformly randomized item selection. This study investigated potential damage caused by organized item theft in computerized adaptive…

Computerized Adaptive Assessment of Cognitive Abilities among Disabled Adults.

ERIC Educational Resources Information Center

Engdahl, Brian

This study examined computerized adaptive testing and cognitive ability testing of adults with cognitive disabilities. Adult subjects (N=250) were given computerized tests on language usage and space relations in one of three administration conditions: paper and pencil, fixed length computer adaptive, and variable length computer adaptive.…

Development and Evaluation of a Confidence-Weighting Computerized Adaptive Testing

ERIC Educational Resources Information Center

Yen, Yung-Chin; Ho, Rong-Guey; Chen, Li-Ju; Chou, Kun-Yi; Chen, Yan-Lin

2010-01-01

The purpose of this study was to examine whether the efficiency, precision, and validity of computerized adaptive testing (CAT) could be improved by assessing confidence differences in knowledge that examinees possessed. We proposed a novel polytomous CAT model called the confidence-weighting computerized adaptive testing (CWCAT), which combined a…

Year 2000 Computerized Farm Project. Final Report.

ERIC Educational Resources Information Center

McGrann, James M.; Lippke, Lawrence A.

An ongoing project was funded to develop and demonstrate a computerized approach to operation and management of a commercial-sized farm. Other project objectives were to facilitate the demonstration of the computerized farm to the public and to develop individual software packages and make them available to the public. Project accomplishments…

10 CFR 719.44 - What categories of costs require advance approval?

Code of Federal Regulations, 2014 CFR

2014-01-01

... application software, or non-routine computerized databases, if they are specifically created for a particular matter. For costs associated with the creation and use of computerized databases, contractors and retained legal counsel must ensure that the creation and use of computerized databases is necessary and...

Computerized Diagnostic Testing: Problems and Possibilities.

ERIC Educational Resources Information Center

McArthur, David L.

The use of computers to build diagnostic inferences is explored in two contexts. In computerized monitoring of liquid oxygen systems for the space shuttle, diagnoses are exact because they can be derived within a world which is closed. In computerized classroom testing of reading comprehension, programs deliver a constrained form of adaptive…

45 CFR 307.13 - Security and confidentiality for computerized support enforcement systems in operation after...

Code of Federal Regulations, 2010 CFR

2010-10-01

... ENFORCEMENT SYSTEMS § 307.13 Security and confidentiality for computerized support enforcement systems in... systems in operation after October 1, 1997. (a) Information integrity and security. Have safeguards... 45 Public Welfare 2 2010-10-01 2010-10-01 false Security and confidentiality for computerized...

A First Life with Computerized Business Simulations

ERIC Educational Resources Information Center

Thavikulwat, Precha

2011-01-01

The author discusses the theoretical lens, origins, and environment of his work on computerized business simulations. Key ideas that inform his work include the two dimensions (control and interaction) of computerized simulation, the two ways of representing a natural process (phenotypical and genotypical) in a simulation, which he defines as a…

45 CFR 307.15 - Approval of advance planning documents for computerized support enforcement systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES COMPUTERIZED SUPPORT ENFORCEMENT SYSTEMS..., organization, services and constraints related to the computerized support enforcement system; (4) The APD must... design, development, installation or enhancement; (5) The APD must contain a description of each...

45 CFR 307.15 - Approval of advance planning documents for computerized support enforcement systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES COMPUTERIZED SUPPORT ENFORCEMENT SYSTEMS..., organization, services and constraints related to the computerized support enforcement system; (4) The APD must... design, development, installation or enhancement; (5) The APD must contain a description of each...

45 CFR 307.15 - Approval of advance planning documents for computerized support enforcement systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES COMPUTERIZED SUPPORT ENFORCEMENT SYSTEMS..., organization, services and constraints related to the computerized support enforcement system; (4) The APD must... design, development, installation or enhancement; (5) The APD must contain a description of each...

Protecting Privacy in Computerized Medical Information.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Office of Technology Assessment.

This report analyzes the implications of computerized medical information and the challenges it brings to individual privacy. The report examines the nature of the privacy interest in health care information and the current state of the law protecting that information; the nature of proposals to computerize health care information and the…

45 CFR 310.25 - What conditions apply to acquisitions of Computerized Tribal IV-D Systems?

Code of Federal Regulations, 2010 CFR

2010-10-01

... FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES COMPUTERIZED TRIBAL IV-D SYSTEMS AND OFFICE AUTOMATION... Acquisition Threshold; (c) Software and ownership rights. (1) All procurement and contract instruments must... Computerized Tribal IV-D System software or enhancements thereof and all associated documentation designed...

Computerization of the Newspaper in the 1980s.

ERIC Educational Resources Information Center

Garrison, Bruce

A review of the literature on the computerization of newspaper newsrooms shows that since 1960, computers have assumed an increasingly important role in information collection, news writing and editing, pagination, and news transmission. When newspaper libraries are computerized, reporters are able to find information more quickly and to use…

[Computerized medical record: deontology and legislation].

PubMed

Allaert, F A; Dusserre, L

1996-02-01

Computerization of medical records is making headway for patients' follow-up, scientific research, and health expenses control, but it must not alter the guarantees provided to the patients by the medical code of ethics and the law of January 6, 1978. This law, modified on July 1, 1994, requires to register all computerized records of personal data and establishes rights to protect privacy against computer misdemeanor. All medical practitioners using computerized medical records must be aware that the infringement of this law may provoke suing in professional, civil or criminal court.

Is there a link between the hospital-acquired injurious fall rates in US acute care hospitals and these institutions' implementation levels of computerized systems?

PubMed

Tzeng, Huey-Ming; Hu, Hsou Mei; Yin, Chang-Yi

2011-12-01

Medicare no longer reimburses acute care hospitals for the costs of additional care required due to hospital-acquired injuries. Consequently, this study explored the effective computerized systems to inform practice for better interventions to reduce fall risk. It provided a correlation between type of computerized system and hospital-acquired injurious fall rates at acute care hospitals in California, Florida, and New York. It used multiple publicly available data sets, with the hospital as the unit of analysis. Descriptive and Pearson correlation analyses were used. The analysis included 462 hospitals. Significant correlations could be categorized into two groups: (1) meaningful computerized systems that were associated with lower injurious fall rates: the decision support systems for drug allergy alerts, drug-drug interaction alerts, and drug-laboratory interaction alerts; and (2) computerized systems that were associated with higher injurious fall rates: the decision support system for drug-drug interaction alerts and the computerized provider order entry system for radiology tests. Future research may include additional states, multiple years of data, and patient-level data to validate this study's findings. This effort may further inform policy makers and the public about effective clinical computerized systems provided to clinicians to improve their practice decisions and care outcomes.

Uncertainty loops in travel-time tomography from nonlinear wave physics.

PubMed

Galetti, Erica; Curtis, Andrew; Meles, Giovanni Angelo; Baptie, Brian

2015-04-10

Estimating image uncertainty is fundamental to guiding the interpretation of geoscientific tomographic maps. We reveal novel uncertainty topologies (loops) which indicate that while the speeds of both low- and high-velocity anomalies may be well constrained, their locations tend to remain uncertain. The effect is widespread: loops dominate around a third of United Kingdom Love wave tomographic uncertainties, changing the nature of interpretation of the observed anomalies. Loops exist due to 2nd and higher order aspects of wave physics; hence, although such structures must exist in many tomographic studies in the physical sciences and medicine, they are unobservable using standard linearized methods. Higher order methods might fruitfully be adopted.

Tomographic diffractive microscopy with a wavefront sensor.

PubMed

Ruan, Y; Bon, P; Mudry, E; Maire, G; Chaumet, P C; Giovannini, H; Belkebir, K; Talneau, A; Wattellier, B; Monneret, S; Sentenac, A

2012-05-15

Tomographic diffractive microscopy is a recent imaging technique that reconstructs quantitatively the three-dimensional permittivity map of a sample with a resolution better than that of conventional wide-field microscopy. Its main drawbacks lie in the complexity of the setup and in the slowness of the image recording as both the amplitude and the phase of the field scattered by the sample need to be measured for hundreds of successive illumination angles. In this Letter, we show that, using a wavefront sensor, tomographic diffractive microscopy can be implemented easily on a conventional microscope. Moreover, the number of illuminations can be dramatically decreased if a constrained reconstruction algorithm is used to recover the sample map of permittivity.

5D-intravital tomography as a novel tool for non-invasive in-vivo analysis of human skin

NASA Astrophysics Data System (ADS)

König, Karsten; Weinigel, Martin; Breunig, Hans G.; Gregory, Axel; Fischer, Peter; Kellner-Höfer, Marcel; Bückle, Rainer; Schwarz, Martin; Riemann, Iris; Stracke, Frank; Huck, Volker; Gorzelanny, Christian; Schneider, Stefan W.

2010-02-01

Some years ago, CE-marked clinical multiphoton systems for 3D imaging of human skin with subcellular resolution have been launched. These tomographs provide optical biopsies with submicron resolution based on two-photon excited autofluorescence (NAD(P)H, flavoproteins, keratin, elastin, melanin, porphyrins) and second harmonic generation by collagen. The 3D tomograph was now transferred into a 5D imaging system by the additional detection of the emission spectrum and the fluorescence lifetime based on spatially and spectrally resolved time-resolved single photon counting. The novel 5D intravital tomograph (5D-IVT) was employed for the early detection of atopic dermatitis and the analysis of treatment effects.

Tomographic and analog 3-D simulations using NORA. [Non-Overlapping Redundant Image Array formed by multiple pinholes

NASA Technical Reports Server (NTRS)

Yin, L. I.; Trombka, J. I.; Bielefeld, M. J.; Seltzer, S. M.

1984-01-01

The results of two computer simulations demonstrate the feasibility of using the nonoverlapping redundant array (NORA) to form three-dimensional images of objects with X-rays. Pinholes admit the X-rays to nonoverlapping points on a detector. The object is reconstructed in the analog mode by optical correlation and in the digital mode by tomographic computations. Trials were run with a stick-figure pyramid and extended objects with out-of-focus backgrounds. Substitution of spherical optical lenses for the pinholes increased the light transmission sufficiently that objects could be easily viewed in a dark room. Out-of-focus aberrations in tomographic reconstruction could be eliminated using Chang's (1976) algorithm.

Tomographic phase microscopy: principles and applications in bioimaging [Invited

PubMed Central

Jin, Di; Zhou, Renjie; Yaqoob, Zahid; So, Peter T. C.

2017-01-01

Tomographic phase microscopy (TPM) is an emerging optical microscopic technique for bioimaging. TPM uses digital holographic measurements of complex scattered fields to reconstruct three-dimensional refractive index (RI) maps of cells with diffraction-limited resolution by solving inverse scattering problems. In this paper, we review the developments of TPM from the fundamental physics to its applications in bioimaging. We first provide a comprehensive description of the tomographic reconstruction physical models used in TPM. The RI map reconstruction algorithms and various regularization methods are discussed. Selected TPM applications for cellular imaging, particularly in hematology, are reviewed. Finally, we examine the limitations of current TPM systems, propose future solutions, and envision promising directions in biomedical research. PMID:29386746

Clinical confocal microlaparoscope for real-time in vivo optical biopsies

NASA Astrophysics Data System (ADS)

Tanbakuchi, Anthony A.; Rouse, Andrew R.; Udovich, Joshua A.; Hatch, Kenneth D.; Gmitro, Arthur F.

2009-07-01

Successful treatment of cancer is highly dependent on the stage at which it is diagnosed. Early diagnosis, when the disease is still localized at its origin, results in very high cure rates-even for cancers that typically have poor prognosis. Biopsies are often used for diagnosis of disease. However, because biopsies are destructive, only a limited number can be taken. This leads to reduced sensitivity for detection due to sampling error. A real-time fluorescence confocal microlaparoscope has been developed that provides instant in vivo cellular images, comparable to those provided by histology, through a nondestructive procedure. The device includes an integrated contrast agent delivery mechanism and a computerized depth scan system. The instrument uses a fiber bundle to relay the image plane of a slit-scan confocal microlaparoscope into tissue. It has a 3-μm lateral resolution and a 25-μm axial resolution. Initial in vivo clinical testing using the device to image human ovaries has been done in 21 patients. Results indicate that the device can successfully image organs in vivo without complications. Results with excised tissue demonstrate that the instrument can resolve sufficient cellular detail to visualize the cellular changes associated with the onset of cancer.

Finite element analysis of functionally graded bone plate at femur bone fracture site

NASA Astrophysics Data System (ADS)

Satapathy, Pravat Kumar; Sahoo, Bamadev; Panda, L. N.; Das, S.

2018-03-01

This paper focuses on the analysis of fractured Femur bone with functionally graded bone plate. The Femur bone is modeled by using the data from the CT (Computerized Tomography) scan and the material properties are assigned using Mimics software. The fracture fixation plate used here is composed of Functionally Graded Material (FGM). The functionally graded bone plate is considered to be composed of different layers of homogeneous materials. Finite element method approach is adopted for analysis. The volume fraction of the material is calculated by considering its variation along the thickness direction (z) according to a power law and the effective properties of the homogeneous layers are estimated. The model developed is validated by comparing numerical results available in the literature. Static analysis has been performed for the bone plate system by considering both axial compressive load and torsional load. The investigation shows that by introducing FG bone plate instead of titanium, the stress at the fracture site increases by 63 percentage and the deformation decreases by 15 percentage, especially when torsional load is taken into consideration. The present model yields better results in comparison with the commercially available bone plates.

Surgiplanner: a new method for one step oral rehabilitation of severe atrophic maxilla

PubMed Central

BUSATO, A.; VISMARA, V.; GRECCHI, F.; GRECCHI, E.; LAURITANO, D.

2017-01-01

SUMMARY The implant-prosthetic rehabilitation of edentulous upper jaws has always been complex for surgeons and dentists. The lack of bone in both vertical and horizontal dimension does not allow the correct insertion of dental implants. In addition, patients with edentulous upper and lower arch have a loss of vertical dimension of the face and an aged expression. Many surgical techniques have been proposed to increase the bone volume, height and thickness, such as the Le Fort I osteotomy, the bone grafts and the placement of dental implants. Planning these surgical procedures is difficult, because it is not possible to reproduce the movements of osteotomized bone segments in three planes of space. This article describes the treatment of severe atrophy maxilla with a new approach using a new instrument named “Surgiplanner”. Surgiplanner is a method that, only using a computerized axial tomography (CAT), allows to obtain a totally predetermined therapeutic result from both an aesthetic and functional point of view, with surgery of severe resorbed jaws. Surgiplanner allows repositioning of segment of the skeleton of the patient’s face in a predetermined and controlled way for the best implant-supported oral rehabilitation. PMID:29285336

Surgiplanner: a new method for one step oral rehabilitation of severe atrophic maxilla.

PubMed

Busato, A; Vismara, V; Grecchi, F; Grecchi, E; Lauritano, D

2017-01-01

The implant-prosthetic rehabilitation of edentulous upper jaws has always been complex for surgeons and dentists. The lack of bone in both vertical and horizontal dimension does not allow the correct insertion of dental implants. In addition, patients with edentulous upper and lower arch have a loss of vertical dimension of the face and an aged expression. Many surgical techniques have been proposed to increase the bone volume, height and thickness, such as the Le Fort I osteotomy, the bone grafts and the placement of dental implants. Planning these surgical procedures is difficult, because it is not possible to reproduce the movements of osteotomized bone segments in three planes of space. This article describes the treatment of severe atrophy maxilla with a new approach using a new instrument named "Surgiplanner". Surgiplanner is a method that, only using a computerized axial tomography (CAT), allows to obtain a totally predetermined therapeutic result from both an aesthetic and functional point of view, with surgery of severe resorbed jaws. Surgiplanner allows repositioning of segment of the skeleton of the patient's face in a predetermined and controlled way for the best implant-supported oral rehabilitation.

T-ray tomography.

PubMed

Mittleman, D M; Hunsche, S; Boivin, L; Nuss, M C

1997-06-15

We demonstrate tomographic T-ray imaging, using the timing information present in terahertz (THz) pulses in a reflection geometry. THz pulses are reflected from refractive-index discontinuities inside an object, and the time delays of these pulses are used to determine the positions of the discontinuities along the propagation direction. In this fashion a tomographic image can be constructed.

Computed tomographic findings of cerebral fat embolism following multiple bone fractures.

PubMed

Law, Huong Ling; Wong, Siong Lung; Tan, Suzet

2013-02-01

Fat embolism to the lungs and brain is an uncommon complication following fractures. Few reports with descriptions of computed tomographic (CT) findings of emboli to the brain or cerebral fat embolism are available. We report a case of cerebral fat embolism following multiple skeletal fractures and present its CT findings here.

Quantum-tomographic cryptography with a semiconductor single-photon source

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

Kaszlikowski, D.; Yang, L.J.; Yong, L.S.

2005-09-15

We analyze the security of so-called quantum-tomographic cryptography with the source producing entangled photons via an experimental scheme proposed by Fattal et al. [Phys. Rev. Lett. 92, 37903 (2004)]. We determine the range of the experimental parameters for which the protocol is secure against the most general incoherent attacks.

A computerized clinical decision support system as a means of implementing depression guidelines.

PubMed

Trivedi, Madhukar H; Kern, Janet K; Grannemann, Bruce D; Altshuler, Kenneth Z; Sunderajan, Prabha

2004-08-01

The authors describe the history and current use of computerized systems for implementing treatment guidelines in general medicine as well as the development, testing, and early use of a computerized decision support system for depression treatment among "real-world" clinical settings in Texas. In 1999 health care experts from Europe and the United States met to confront the well-documented challenges of implementing treatment guidelines and to identify strategies for improvement. They suggested the integration of guidelines into computer systems that is incorporated into clinical workflow. Several studies have demonstrated improvements in physicians' adherence to guidelines when such guidelines are provided in a computerized format. Although computerized decision support systems are being used in many areas of medicine and have demonstrated improved patient outcomes, their use in psychiatric illness is limited. The authors designed and developed a computerized decision support system for the treatment of major depressive disorder by using evidence-based guidelines, transferring the knowledge gained from the Texas Medication Algorithm Project (TMAP). This computerized decision support system (CompTMAP) provides support in diagnosis, treatment, follow-up, and preventive care and can be incorporated into the clinical setting. CompTMAP has gone through extensive testing to ensure accuracy and reliability. Physician surveys have indicated a positive response to CompTMAP, although the sample was insufficient for statistical testing. CompTMAP is part of a new era of comprehensive computerized decision support systems that take advantage of advances in automation and provide more complete clinical support to physicians in clinical practice.

Current developments in clinical multiphoton tomography

NASA Astrophysics Data System (ADS)

König, Karsten; Weinigel, Martin; Breunig, Hans Georg; Gregory, Axel; Fischer, Peter; Kellner-Höfer, Marcel; Bückle, Rainer

2010-02-01

Two-photon microscopy has been introduced in 1990 [1]. 13 years later, CE-marked clinical multiphoton systems for 3D imaging of human skin with subcellular resolution have been launched by the JenLab company with the tomograph DermaInspectTM. In 2010, the second generation of clinical multiphoton tomographs was introduced. The novel mobile multiphoton tomograph MPTflexTM, equipped with a flexible articulated optical arm, provides an increased flexibility and accessibility especially for clinical and cosmetical examinations. The multiphoton excitation of fluorescent biomolecules like NAD(P)H, flavins, porphyrins, elastin, and melanin as well as the second harmonic generation of collagen is induced by picojoule femtosecond laser pulses from an tunable turn-key near infrared laser system. The ability for rapid highquality image acquisition, the user-friendly operation of the system, and the compact and flexible design qualifies this system to be used for melanoma detection, diagnostics of dermatological disorders, cosmetic research, and skin aging measurements as well as in situ drug monitoring and animal research. So far, more than 1,000 patients and volunteers have been investigated with the multiphoton tomographs in Europe, Asia, and Australia.

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

Ceglio, N.M.; George, E.V.; Brooks, K.M.

The first successful demonstration of high resolution, tomographic imaging of a laboratory plasma using coded imaging techniques is reported. ZPCI has been used to image the x-ray emission from laser compressed DT filled microballoons. The zone plate camera viewed an x-ray spectral window extending from below 2 keV to above 6 keV. It exhibited a resolution approximately 8 ..mu..m, a magnification factor approximately 13, and subtended a radiation collection solid angle at the target approximately 10/sup -2/ sr. X-ray images using ZPCI were compared with those taken using a grazing incidence reflection x-ray microscope. The agreement was excellent. In addition,more » the zone plate camera produced tomographic images. The nominal tomographic resolution was approximately 75 ..mu..m. This allowed three dimensional viewing of target emission from a single shot in planar ''slices''. In addition to its tomographic capability, the great advantage of the coded imaging technique lies in its applicability to hard (greater than 10 keV) x-ray and charged particle imaging. Experiments involving coded imaging of the suprathermal x-ray and high energy alpha particle emission from laser compressed microballoon targets are discussed.« less

Tomography and the Herglotz-Wiechert inverse formulation

NASA Astrophysics Data System (ADS)

Nowack, Robert L.

1990-04-01

In this paper, linearized tomography and the Herglotz-Wiechert inverse formulation are compared. Tomographic inversions for 2-D or 3-D velocity structure use line integrals along rays and can be written in terms of Radon transforms. For radially concentric structures, Radon transforms are shown to reduce to Abel transforms. Therefore, for straight ray paths, the Abel transform of travel-time is a tomographic algorithm specialized to a one-dimensional radially concentric medium. The Herglotz-Wiechert formulation uses seismic travel-time data to invert for one-dimensional earth structure and is derived using exact ray trajectories by applying an Abel transform. This is of historical interest since it would imply that a specialized tomographic-like algorithm has been used in seismology since the early part of the century (see Herglotz, 1907; Wiechert, 1910). Numerical examples are performed comparing the Herglotz-Wiechert algorithm and linearized tomography along straight rays. Since the Herglotz-Wiechert algorithm is applicable under specific conditions, (the absence of low velocity zones) to non-straight ray paths, the association with tomography may prove to be useful in assessing the uniqueness of tomographic results generalized to curved ray geometries.

A detailed comparison of single-camera light-field PIV and tomographic PIV

NASA Astrophysics Data System (ADS)

Shi, Shengxian; Ding, Junfei; Atkinson, Callum; Soria, Julio; New, T. H.

2018-03-01

This paper conducts a comprehensive study between the single-camera light-field particle image velocimetry (LF-PIV) and the multi-camera tomographic particle image velocimetry (Tomo-PIV). Simulation studies were first performed using synthetic light-field and tomographic particle images, which extensively examine the difference between these two techniques by varying key parameters such as pixel to microlens ratio (PMR), light-field camera Tomo-camera pixel ratio (LTPR), particle seeding density and tomographic camera number. Simulation results indicate that the single LF-PIV can achieve accuracy consistent with that of multi-camera Tomo-PIV, but requires the use of overall greater number of pixels. Experimental studies were then conducted by simultaneously measuring low-speed jet flow with single-camera LF-PIV and four-camera Tomo-PIV systems. Experiments confirm that given a sufficiently high pixel resolution, a single-camera LF-PIV system can indeed deliver volumetric velocity field measurements for an equivalent field of view with a spatial resolution commensurate with those of multi-camera Tomo-PIV system, enabling accurate 3D measurements in applications where optical access is limited.

Computerized Adaptive Test (CAT) Applications and Item Response Theory Models for Polytomous Items

ERIC Educational Resources Information Center

Aybek, Eren Can; Demirtasli, R. Nukhet

2017-01-01

This article aims to provide a theoretical framework for computerized adaptive tests (CAT) and item response theory models for polytomous items. Besides that, it aims to introduce the simulation and live CAT software to the related researchers. Computerized adaptive test algorithm, assumptions of item response theory models, nominal response…

Computerized Testing of Level III Associate Degree Nursing Students versus Paper and Pencil Testing Methods

ERIC Educational Resources Information Center

Gullo, Shirna R.

2014-01-01

Computerized testing may be one solution to enhance performance on the curricular Health Education Systems Inc. (HESI) exam and the National Council Licensure Exam for Registered Nurses (NCLEX-RN). Due to the integration of improved technological processes and procedures in healthcare for computerized documentation and electronicmedical records,…

Computerized Dynamic Adaptive Tests with Immediately Individualized Feedback for Primary School Mathematics Learning

ERIC Educational Resources Information Center

Wu, Huey-Min; Kuo, Bor-Chen; Wang, Su-Chen

2017-01-01

In this study, a computerized dynamic assessment test with both immediately individualized feedback and adaptively property was applied to Mathematics learning in primary school. For evaluating the effectiveness of the computerized dynamic adaptive test, the performances of three types of remedial instructions were compared by a pre-test/post-test…

Computerized Management of Physical Plant Services.

ERIC Educational Resources Information Center

Hawkey, Earl W.; Kleinpeter, Joseph

Outlining the major areas to be considered when deciding whether or not to computerize physical plant services in higher education institutions, the author points out the shortcomings of manual record keeping systems. He gives five factors to consider when deciding to computerize: (1) time and money, (2) extent of operation, (3) current and future…

The Evaluation of SISMAKOM (Computerized SDI Project).

ERIC Educational Resources Information Center

University of Science, Penang (Malaysia).

A survey of 88 users of SISMAKOM, a computerized selective dissemination of information (SDI) and document delivery service provided by the Universiti Sains Malaysia and four other Malaysian universities, was conducted in August 1982 in order to collect data about SISMAKOM and to assess the value of a computerized SDI service in a developing…

An Assistive Computerized Learning Environment for Distance Learning Students with Learning Disabilities

ERIC Educational Resources Information Center

Klemes, Joel; Epstein, Alit; Zuker, Michal; Grinberg, Nira; Ilovitch, Tamar

2006-01-01

The current study examines how a computerized learning environment assists students with learning disabilities (LD) enrolled in a distance learning course at the Open University of Israel. The technology provides computer display of the text, synchronized with auditory output and accompanied by additional computerized study skill tools which…

The Effect of College Students' Self-Generated Computerized Mind Mapping on Their Reading Achievement

ERIC Educational Resources Information Center

Sabbah, Sabah Salman

2015-01-01

This study explored the potential effect of college students' self-generated computerized mind maps on their reading comprehension. It also investigated the subjects' attitudes toward generating computerized mind maps for reading comprehension. The study was conducted in response to the inability of the foundation-level students, who were learning…

The Impact of Computerization on Archival Finding Aids: A RAMP Study.

ERIC Educational Resources Information Center

Kitching, Christopher

This report is based on a questionnaire sent to 32 selected National Archives and on interviews with archivists from eight countries. Geared to the needs of developing countries, the report covers: (1) the impact of computerization on finding aids; (2) advantages and problems of computerization, including enhanced archival control, integration of…

The effects of whole body vibration combined computerized postural control training on the lower extremity muscle activity and cerebral cortex activity in stroke patients.

PubMed

Uhm, Yo-Han; Yang, Dae-Jung

2018-02-01

[Purpose] The purpose of this study was to examine the effect of computerized postural control training using whole body vibration on lower limb muscle activity and cerebral cortical activation in acute stroke patients. [Subjects and Methods] Thirty stroke patients participated and were divided into groups of 10, a group of the computerized postural control training using whole body vibration (Group I), the computerized postural control training combined with aero step (Group II) and computerized postural control training (Group III). MP100 was used to measure lower limb muscle activity, and QEEG-8 was used to measure cerebral cortical activation. [Results] Comparison of muscle activity and cerebral cortical activation before and after intervention between groups showed that Group I had significant differences in lower limb muscle activity and cerebral cortical activation compared to Groups II and III. [Conclusion] This study showed that whole body vibration combined computerized postural control training is effective for improving muscle activity and cerebral cortex activity in stroke patients.

Computed Tomographic Airway Morphology in Chronic Obstructive Pulmonary Disease. Remodeling or Innate Anatomy?

PubMed

Diaz, Alejandro A; Estépar, Raul San José; Washko, George R

2016-01-01

Computed tomographic measures of central airway morphology have been used in clinical, epidemiologic, and genetic investigation as an inference of the presence and severity of small-airway disease in smokers. Although several association studies have brought us to believe that these computed tomographic measures reflect airway remodeling, a careful review of such data and more recent evidence may reveal underappreciated complexity to these measures and limitations that prompt us to question that belief. This Perspective offers a review of seminal papers and alternative explanations of their data in the light of more recent evidence. The relationships between airway morphology and lung function are observed in subjects who never smoked, implying that native airway structure indeed contributes to lung function; computed tomographic measures of central airways such as wall area, lumen area, and total bronchial area are smaller in smokers with chronic obstructive pulmonary disease versus those without chronic obstructive pulmonary disease; and the airways are smaller as disease severity increases. The observations suggest that (1) native airway morphology likely contributes to the relationships between computed tomographic measures of airways and lung function; and (2) the presence of smaller airways in those with chronic obstructive pulmonary disease versus those without chronic obstructive pulmonary disease as well as their decrease with disease severity suggests that smokers with chronic obstructive pulmonary disease may simply have smaller airways to begin with, which put them at greater risk for the development of smoking-related disease.

Hierarchical multimodal tomographic x-ray imaging at a superbend

NASA Astrophysics Data System (ADS)

Stampanoni, M.; Marone, F.; Mikuljan, G.; Jefimovs, K.; Trtik, P.; Vila-Comamala, J.; David, C.; Abela, R.

2008-08-01

Over the last decade, synchrotron-based X-ray tomographic microscopy has established itself as a fundamental tool for non-invasive, quantitative investigations of a broad variety of samples, with application ranging from space research and materials science to biology and medicine. Thanks to the brilliance of modern third generation sources, voxel sizes in the micrometer range are routinely achieved by the major X-ray microtomography devices around the world, while the isotropic 100 nm barrier is reached and trespassed only by few instruments. The beamline for TOmographic Microscopy and Coherent rAdiology experiments (TOMCAT) of the Swiss Light Source at the Paul Scherrer Institut, operates a multimodal endstation which offers tomographic capabilities in the micrometer range in absorption contrast - of course - as well as phase contrast imaging. Recently, the beamline has been equipped with a full field, hard X-rays microscope with a theoretical pixel size down to 30 nm and a field of view of 50 microns. The nanoscope performs well at X-ray energies between 8 and 12 keV, selected from the white beam of a 2.9 T superbend by a [Ru/C]100 fixed exit multilayer monochromator. In this work we illustrate the experimental setup dedicated to the nanoscope, in particular the ad-hoc designed X-ray optics needed to produce a homogeneous, square illumination of the sample imaging plane as well as the magnifying zone plate. Tomographic reconstructions at 60 nm voxel size will be shown and discussed.

DIRECT OBSERVATION OF SOLAR CORONAL MAGNETIC FIELDS BY VECTOR TOMOGRAPHY OF THE CORONAL EMISSION LINE POLARIZATIONS

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

Kramar, M.; Lin, H.; Tomczyk, S., E-mail: kramar@cua.edu, E-mail: lin@ifa.hawaii.edu, E-mail: tomczyk@ucar.edu

We present the first direct “observation” of the global-scale, 3D coronal magnetic fields of Carrington Rotation (CR) Cycle 2112 using vector tomographic inversion techniques. The vector tomographic inversion uses measurements of the Fe xiii 10747 Å Hanle effect polarization signals by the Coronal Multichannel Polarimeter (CoMP) and 3D coronal density and temperature derived from scalar tomographic inversion of Solar Terrestrial Relations Observatory (STEREO)/Extreme Ultraviolet Imager (EUVI) coronal emission lines (CELs) intensity images as inputs to derive a coronal magnetic field model that best reproduces the observed polarization signals. While independent verifications of the vector tomography results cannot be performed, wemore » compared the tomography inverted coronal magnetic fields with those constructed by magnetohydrodynamic (MHD) simulations based on observed photospheric magnetic fields of CR 2112 and 2113. We found that the MHD model for CR 2112 is qualitatively consistent with the tomography inverted result for most of the reconstruction domain except for several regions. Particularly, for one of the most noticeable regions, we found that the MHD simulation for CR 2113 predicted a model that more closely resembles the vector tomography inverted magnetic fields. In another case, our tomographic reconstruction predicted an open magnetic field at a region where a coronal hole can be seen directly from a STEREO-B/EUVI image. We discuss the utilities and limitations of the tomographic inversion technique, and present ideas for future developments.« less

Relative arrival-time upper-mantle tomography and the elusive background mean

NASA Astrophysics Data System (ADS)

Bastow, Ian D.

2012-08-01

The interpretation of seismic tomographic images of upper-mantle seismic wave speed structure is often a matter of considerable debate because the observations can usually be explained by a range of hypotheses, including variable temperature, composition, anisotropy, and the presence of partial melt. An additional problem, often overlooked in tomographic studies using relative as opposed to absolute arrival-times, is the issue of the resulting velocity model's zero mean. In shield areas, for example, relative arrival-time analysis strips off a background mean velocity structure that is markedly fast compared to the global average. Conversely, in active areas, the background mean is often markedly slow compared to the global average. Appreciation of this issue is vital when interpreting seismic tomographic images: 'high' and 'low' velocity anomalies should not necessarily be interpreted, respectively, as 'fast' and 'slow' compared to 'normal mantle'. This issue has been discussed in the seismological literature in detail over the years, yet subsequent tomography studies have still fallen into the trap of mis-interpreting their velocity models. I highlight here some recent examples of this and provide a simple strategy to address the problem using constraints from a recent global tomographic model, and insights from catalogues of absolute traveltime anomalies. Consultation of such absolute measures of seismic wave speed should be routine during regional tomographic studies, if only for the benefit of the broader Earth Science community, who readily follow the red = hot and slow, blue = cold and fast rule of thumb when interpreting the images for themselves.

[Is the ICU staff satisfied with the computerized physician order entry? A cross-sectional survey study].

PubMed

Fumis, Renata Rego Lins; Costa, Eduardo Leite Vieira; Martins, Paulo Sergio; Pizzo, Vladimir; Souza, Ivens Augusto; Schettino, Guilherme de Paula Pinto

2014-01-01

To evaluate the satisfaction of the intensive care unit staff with a computerized physician order entry and to compare the concept of the computerized physician order entry relevance among intensive care unit healthcare workers. We performed a cross-sectional survey to assess the satisfaction of the intensive care unit staff with the computerized physician order entry in a 30-bed medical/surgical adult intensive care unit using a self-administered questionnaire. The questions used for grading satisfaction levels were answered according to a numerical scale that ranged from 1 point (low satisfaction) to 10 points (high satisfaction). The majority of the respondents (n=250) were female (66%) between the ages of 30 and 35 years of age (69%). The overall satisfaction with the computerized physician order entry scored 5.74±2.14 points. The satisfaction was lower among physicians (n=42) than among nurses, nurse technicians, respiratory therapists, clinical pharmacists and diet specialists (4.62±1.79 versus 5.97±2.14, p<0.001); satisfaction decreased with age (p<0.001). Physicians scored lower concerning the potential of the computerized physician order entry for improving patient safety (5.45±2.20 versus 8.09±2.21, p<0.001) and the ease of using the computerized physician order entry (3.83±1.88 versus 6.44±2.31, p<0.001). The characteristics independently associated with satisfaction were the system's user-friendliness, accuracy, capacity to provide clear information, and fast response time. Six months after its implementation, healthcare workers were satisfied, albeit not entirely, with the computerized physician order entry. The overall users' satisfaction with computerized physician order entry was lower among physicians compared to other healthcare professionals. The factors associated with satisfaction included the belief that digitalization decreased the workload and contributed to the intensive care unit quality with a user-friendly and accurate system and that digitalization provided concise information within a reasonable time frame.

Downscaling Smooth Tomographic Models: Separating Intrinsic and Apparent Anisotropy

NASA Astrophysics Data System (ADS)

Bodin, Thomas; Capdeville, Yann; Romanowicz, Barbara

2016-04-01

In recent years, a number of tomographic models based on full waveform inversion have been published. Due to computational constraints, the fitted waveforms are low pass filtered, which results in an inability to map features smaller than half the shortest wavelength. However, these tomographic images are not a simple spatial average of the true model, but rather an effective, apparent, or equivalent model that provides a similar 'long-wave' data fit. For example, it can be shown that a series of horizontal isotropic layers will be seen by a 'long wave' as a smooth anisotropic medium. In this way, the observed anisotropy in tomographic models is a combination of intrinsic anisotropy produced by lattice-preferred orientation (LPO) of minerals, and apparent anisotropy resulting from the incapacity of mapping discontinuities. Interpretations of observed anisotropy (e.g. in terms of mantle flow) requires therefore the separation of its intrinsic and apparent components. The "up-scaling" relations that link elastic properties of a rapidly varying medium to elastic properties of the effective medium as seen by long waves are strongly non-linear and their inverse highly non-unique. That is, a smooth homogenized effective model is equivalent to a large number of models with discontinuities. In the 1D case, Capdeville et al (GJI, 2013) recently showed that a tomographic model which results from the inversion of low pass filtered waveforms is an homogenized model, i.e. the same as the model computed by upscaling the true model. Here we propose a stochastic method to sample the ensemble of layered models equivalent to a given tomographic profile. We use a transdimensional formulation where the number of layers is variable. Furthermore, each layer may be either isotropic (1 parameter) or intrinsically anisotropic (2 parameters). The parsimonious character of the Bayesian inversion gives preference to models with the least number of parameters (i.e. least number of layers, and maximum number of isotropic layers). The non-uniqueness of the problem can be addressed by adding high frequency data such as receiver functions, able to map first order discontinuities. We show with synthetic tests that this method enables us to distinguish between intrinsic and apparent anisotropy in tomographic models, as layers with intrinsic anisotropy are only present when required by the data. A real data example is presented based on the latest global model produced at Berkeley.

Spacelab user implementation assessment study (software requirements analysis). Volume 1: Executive study

NASA Technical Reports Server (NTRS)

1976-01-01

The primary objective of this study was to develop an integrated approach for the development, implementation, and utilization of all software that is required to efficiently and cost-effectively support advanced technology laboratory flight and ground operations. It was recognized that certain aspects of the operations would be mandatory computerized services; computerization of other aspects would be optional. Thus, the analyses encompassed not only alternate computer utilization and implementations but trade studies of the programmatic effects of non-computerized versus computerized approaches to the operations. A general overview of the study is presented.

Computerized general practice based networks yield comparable performance with sentinel data in monitoring epidemiological time-course of influenza-like illness and acute respiratory illness.

PubMed

Truyers, Carla; Lesaffre, Emmanuel; Bartholomeeusen, Stefaan; Aertgeerts, Bert; Snacken, René; Brochier, Bernard; Yane, Fernande; Buntinx, Frank

2010-03-22

Computerized morbidity registration networks might serve as early warning systems in a time where natural epidemics such as the H1N1 flu can easily spread from one region to another. In this contribution we examine whether general practice based broad-spectrum computerized morbidity registration networks have the potential to act as a valid surveillance instrument of frequently occurring diseases. We compare general practice based computerized data assessing the frequency of influenza-like illness (ILI) and acute respiratory infections (ARI) with data from a well established case-specific sentinel network, the European Influenza Surveillance Scheme (EISS). The overall frequency and trends of weekly ILI and ARI data are compared using both networks. Detection of influenza-like illness and acute respiratory illness occurs equally fast in EISS and the computerized network. The overall frequency data for ARI are the same for both networks, the overall trends are similar, but the increases and decreases in frequency do not occur in exactly the same weeks. For ILI, the overall rate was slightly higher for the computerized network population, especially before the increase of ILI, the overall trend was almost identical and the increases and decreases occur in the same weeks for both networks. Computerized morbidity registration networks are a valid tool for monitoring frequent occurring respiratory diseases and the detection of sudden outbreaks.

45 CFR 310.20 - What are the conditions for funding the installation, operation, maintenance and enhancement of...

Code of Federal Regulations, 2010 CFR

2010-10-01

... installation, operation, maintenance and enhancement of Computerized Tribal IV-D Systems and Office Automation... HEALTH AND HUMAN SERVICES COMPUTERIZED TRIBAL IV-D SYSTEMS AND OFFICE AUTOMATION Funding for Computerized Tribal IV-D Systems and Office Automation § 310.20 What are the conditions for funding the installation...

45 CFR 310.35 - Under what circumstances would emergency FFP be available for Computerized Tribal IV-D Systems?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Under what circumstances would emergency FFP be... AND OFFICE AUTOMATION Funding for Computerized Tribal IV-D Systems and Office Automation § 310.35 Under what circumstances would emergency FFP be available for Computerized Tribal IV-D Systems? (a...

A Case Study of Different Types of Arguments Emerging from Explorations in an Interactive Computerized Environment

ERIC Educational Resources Information Center

Lavy, Ilana

2006-01-01

This paper presents a description of the different types of arguments that emerged as two students, working in a computerized environment, engaged in an investigation of several number theory concepts. The emerging arguments are seen as a result of the influence of the computerized environment together with collaborative learning. Using…

Development of a Computerized In-Basket Exercise for the Classroom: A Sales Management Example

ERIC Educational Resources Information Center

Pearson, Michael M.; Barnes, John W.; Onken, Marina H.

2006-01-01

This article follows the development of a sales management in-basket exercise for use in the classroom. The authors have computerized the exercise and added features to allow for additional and more quantitative input from the students. The exercise has evolved and been tested in numerous classroom situations. The computerized in-basket exercise…

Technology and Language Testing. A Collection of Papers from the Annual Colloquium on Language Testing Research (7th, Princeton, New Jersey, April 6-9, 1985).

ERIC Educational Resources Information Center

Stansfield, Charles W., Ed.

This collection of essays on measurement theory and language testing includes: "Computerized Adaptive Testing: Implications for Language Test Developers" (Peter Tung); "The Promise and Threat of Computerized Adaptive Assessment of Reading Comprehension" (Michael Canale); "Computerized Rasch Analysis of Item Bias in ESL…

Vocational Education as an Innovation in the Republic of China--Computerization of School Administration.

ERIC Educational Resources Information Center

Chang, Frank Tien-Jin

Computerized school administration has become one of the most crucial innovations in vocational education in Taiwan in the Republic of China. As these educators begin to design or purchase computerized information systems for their own schools, they must first define their specific information needs. Next, they should pay attention to…

Assessment Outcomes: Computerized Instruction in a Human Gross Anatomy Course.

ERIC Educational Resources Information Center

Bukowski, Elaine L.

2002-01-01

The first of three successive classes of beginning physical therapy students (n=17) completed traditional cadaver anatomy lecture/lab; the next 17 a self-study computerized anatomy lab, and the next 20 both lectures and computer lab. No differences in study times and course or licensure exam performance appeared. Computerized self-study is a…

Interdisciplinary Study of Egyptian Mummies from the Pushkin State Museum of Fine Arts Collection at the National Research Centre ``Kurchatov Institute''

NASA Astrophysics Data System (ADS)

Yatsishina, E. B.; Kovalchuk, M. V.; Loshak, M. D.; Vasilyev, S. V.; Vasilieva, O. A.; Dyuzheva, O. P.; Pojidaev, V. M.; Ushakov, V. L.

2018-05-01

Nine ancient Egyptian mummies (dated preliminarily to the period from the 1st mill. BCE to the first centuries CE) from the collection of the State Pushkin Museum of Fine Arts have been studied at the National Research Centre "Kurchatov Institute" (NRC KI) on the base of the complex of NBICS technologies. Tomographic scanning is performed using a magneto-resonance tomograph (3 T) and a hybrid positron emission tomography/computed tomography (PET-CT) scanner. Three-dimensional reconstructions of mummies and their anthropological measurements are carried out. Some medical conclusions are drawn based on the tomographic data. In addition, the embalming composition and tissue of one of the mummies are preliminarily analyzed.

System for plotting subsoil structure and method therefor

NASA Technical Reports Server (NTRS)

Narasimhan, K. Y.; Nathan, R.; Parthasarathy, S. P. (Inventor)

1980-01-01

Data for use in producing a tomograph of subsoil structure between boreholes is derived by pacing spaced geophones in one borehole, on the Earth surface if desired, and by producing a sequence of shots at spaced apart locations in the other borehole. The signals, detected by each of the geophones from the various shots, are processed either on a time of arrival basis, or on the basis of signal amplitude, to provide information of the characteristics of a large number of incremental areas between the boreholes. Such information is useable to produce a tomograph of the subsoil structure between the boreholes. By processing signals of relatively high frequencies, e.g., up to 100 Hz, and by closely spacing the geophones, a high resolution tomograph can be produced.

Robust statistical reconstruction for charged particle tomography

DOEpatents

Schultz, Larry Joe; Klimenko, Alexei Vasilievich; Fraser, Andrew Mcleod; Morris, Christopher; Orum, John Christopher; Borozdin, Konstantin N; Sossong, Michael James; Hengartner, Nicolas W

2013-10-08

Systems and methods for charged particle detection including statistical reconstruction of object volume scattering density profiles from charged particle tomographic data to determine the probability distribution of charged particle scattering using a statistical multiple scattering model and determine a substantially maximum likelihood estimate of object volume scattering density using expectation maximization (ML/EM) algorithm to reconstruct the object volume scattering density. The presence of and/or type of object occupying the volume of interest can be identified from the reconstructed volume scattering density profile. The charged particle tomographic data can be cosmic ray muon tomographic data from a muon tracker for scanning packages, containers, vehicles or cargo. The method can be implemented using a computer program which is executable on a computer.

Data-processing strategies for nano-tomography with elemental specification

NASA Astrophysics Data System (ADS)

Liu, Yijin; Cats, Korneel H.; Nelson Weker, Johanna; Andrews, Joy C.; Weckhuysen, Bert M.; Pianetta, Piero

2013-10-01

Combining the energy tunability provided by synchrotron X-ray sources with transmission X-ray microscopy, the morphology of materials can be resolved in 3D at spatial resolution down to 30 nm with elemental/chemical specification. In order to study the energy dependence of the absorption coefficient over the investigated volume, the tomographic reconstruction and image registration (before and/or after the tomographic reconstruction) are critical. We show in this paper the comparison of two different data processing strategies and conclude that the signal to noise ratio (S/N) in the final result can be improved via performing tomographic reconstruction prior to the evaluation of energy dependence. Our result echoes the dose fractionation theorem, and is particularly helpful when the element of interest has low concentration.

A randomized controlled trial of the Cool Teens CD-ROM computerized program for adolescent anxiety.

PubMed

Wuthrich, Viviana M; Rapee, Ronald M; Cunningham, Michael J; Lyneham, Heidi J; Hudson, Jennifer L; Schniering, Carolyn A

2012-03-01

Computerized cognitive behavioral interventions for anxiety disorders in adults have been shown to be efficacious, but limited data are available on the use of computerized interventions with young persons. Adolescents in particular are difficult to engage in treatment and may be especially suited to computerized technologies. This paper describes the results of a small randomized controlled trial of the Cool Teens program for adolescent anxiety, and examines potential barriers to treatment and user preferences of computerized technology in this population. Forty-three adolescents with a primary diagnosis of anxiety were randomly allocated to the Cool Teens program, a 12-week computerized cognitive-behavioral therapy program for anxiety management, or a 12-week wait list. Effects on symptoms, negative thoughts, and life interference were assessed at post-treatment and 3-month follow-up, based on diagnosis as well as self and maternal report. Using mixed-model analyses, at post-treatment and follow-up assessments, adolescents in the Cool Teens condition, compared with those on the wait list, were found to have significant reductions in the total number of anxiety disorders, the severity of the primary anxiety disorder, and the average severity for all disorders. These results were matched by significant reductions in mother and child questionnaire reports of anxiety, internalizing symptoms, automatic thoughts, and life interference. Further few barriers to treatment were found, and user preferences indicated that the computerized treatment was well suited to adolescents with anxiety. The Cool Teens program is efficacious for treatment of adolescent anxiety. Clinical trial registration information-A randomized controlled trial of the Cool Teens computerized program for anxious adolescents compared with waist list; http://www.anzctr.org.au; ACTRN12611000508976. Copyright © 2012 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Influence of Computerized Sounding Out on Spelling Performance for Children who do and not rely on AAC

PubMed Central

McCarthy, Jillian H.; Hogan, Tiffany P.; Beukelman, David R.; Schwarz, Ilsa E.

2015-01-01

Purpose Spelling is an important skill for individuals who rely on augmentative alternative communication (AAC). The purpose of this study was to investigate how computerized sounding out influenced spelling accuracy of pseudo-words. Computerized sounding out was defined as a word elongated, thus providing an opportunity for a child to hear all the sounds in the word at a slower rate. Methods Seven children with cerebral palsy, four who use AAC and three who do not, participated in a single subject AB design. Results The results of the study indicated that the use of computerized sounding out increased the phonologic accuracy of the pseudo-words produced by participants. Conclusion The study provides preliminary evidence for the use of computerized sounding out during spelling tasks for children with cerebral palsy who do and do not use AAC. Future directions and clinical implications are discussed. PMID:24512195

Can ureteral stones cause pain without causing hydronephrosis?

PubMed

Song, Yan; Hernandez, Natalia; Gee, Michael S; Noble, Vicki E; Eisner, Brian H

2016-09-01

While computerized tomography (CT) is the gold standard for diagnosis of ureterolithiasis, ultrasound is a less costly and radiation-free alternative which is commonly used to evaluate patients with ureteral colic. The purpose of this study was to evaluate the frequency with which patients with ureteral stones and renal colic demonstrate hydronephrosis in order to better understand the evaluation of these patients. Two hundred and forty-eight consecutive patients presenting with ureteral colic and diagnosed with a single unilateral ureteral stone on CT scan in an urban tertiary care emergency department were retrospectively reviewed. Radiology reports were reviewed for stone size, diagnosis, and degree of hydronephrosis. Of the 248 patients evaluated for suspected ureteral stone, 221 (89.1 %) demonstrated any hydronephrosis, while 27 (10.9 %) did not. Hydronephrosis grade, available in 194 patients, was as follows: mild-70.6 %, moderate-27.8 %, and severe-1.5 %. Mean patient age was 47.0 years (SD 15.5), gender distribution was 35.9 % female and 64.1 % male, and mean stone axial diameter was 4.1 mm (SD 2.4). Stone location was as follows: ureteropelvic junction-4.1 %, proximal ureter-21 %, distal ureter-24.9 %, and ureterovesical junction-47.1 %. Axial stone diameter and coronal length (craniocaudal) were both significant predictors of degree of hydronephrosis (ANOVA, p < 0.001 for both). Age (ANOVA, p = NS), stone location (Chi square, p = NS), and gender (Chi square, p = NS) were not associated with degree of hydronephrosis. In patients with ureteral stones and colic, nearly 11 % do not demonstrate any hydronephrosis and a majority (nearly 71 %) will demonstrate only mild hydronephrosis. Stone diameter appears to be related to degree of hydronephrosis, whereas age, gender, and stone location are not. The lower incidence of hydronephrosis for small stones causing renal colic may explain the lower diagnostic accuracy of ultrasound when compared to CT for detecting ureteral stones.

45 CFR 310.15 - What are the safeguards and processes that comprehensive Tribal IV-D agencies must have in place...

Code of Federal Regulations, 2014 CFR

2014-10-01

... comprehensive Tribal IV-D agencies must have in place to ensure the security and privacy of Computerized Tribal... ensure the security and privacy of Computerized Tribal IV-D Systems and Office Automation? (a..., accuracy, completeness, access to, and use of data in the Computerized Tribal IV-D System and Office...

Computerized Adaptive Testing for Polytomous Motivation Items: Administration Mode Effects and a Comparison with Short Forms

ERIC Educational Resources Information Center

Hol, A. Michiel; Vorst, Harrie C. M.; Mellenbergh, Gideon J.

2007-01-01

In a randomized experiment (n = 515), a computerized and a computerized adaptive test (CAT) are compared. The item pool consists of 24 polytomous motivation items. Although items are carefully selected, calibration data show that Samejima's graded response model did not fit the data optimally. A simulation study is done to assess possible…

Does the Computer Make a Difference? Computerized versus Face-to-Face versus Self-Report Assessment of Alcohol, Drug and Tobacco Use.

ERIC Educational Resources Information Center

Skinner, Harvey A.; Allen, Barbara A.

1983-01-01

Compared histories of alcohol, drug, and tobacco use obtained by computerized interview, face-to-face interview, and self-report in clients (N=150) from an addiction treatment center. Multivariate analyses revealed no important differences. The computerized interview was rated less friendly but faster and more interesting. (Author/JAC)

Computerized and Paper-and-Pencil Versions of the Rosenberg Self-Esteem Scale: A Comparison of Psychometric Features and Respondent Preferences.

ERIC Educational Resources Information Center

Vispoel, Walter P.; Boo, Jaeyool; Bleiler, Timothy

2001-01-01

Evaluated the characteristics of computerized and paper-and-pencil versions of the Rosenberg Self-Esteem Scale (SES) using scores for 224 college students. Results show that mode of administration has little effect on the psychometric properties of the SES although the computerized version took longer and was preferred by examinees. (SLD)

Chemical Understanding and Graphing Skills in an Honors Case-Based Computerized Chemistry Laboratory Environment: The Value of Bidirectional Visual and Textual Representations

ERIC Educational Resources Information Center

Dori, Yehudit J.; Sasson, Irit

2008-01-01

The case-based computerized laboratory (CCL) is a chemistry learning environment that integrates computerized experiments with emphasis on scientific inquiry and comprehension of case studies. The research objective was to investigate chemical understanding and graphing skills of high school honors students via bidirectional visual and textual…

Performances on the CogState and Standard Neuropsychological Batteries Among HIV Patients Without Dementia

PubMed Central

Overton, Edgar Turner; Kauwe, John S.K.; Paul, Rob; Tashima, Karen; Tate, David F.; Patel, Pragna; Carpenter, Chuck; Patty, David; Brooks, John T.; Clifford, David B

2013-01-01

HIV-associated neurocognitive disorders (HAND) remain prevalent but challenging to diagnose particularly among non-demented individuals. To determine whether a brief computerized battery correlates with formal neurocognitive testing, we identified 46 HIV-infected persons who had undergone both formal neurocognitive testing and a brief computerized battery. Simple detection tests correlated best with formal neuropsychological testing. By multivariable regression model, 53% of the variance in the composite Global Deficit Score was accounted for by elements from the brief computerized tool (p<0.01). These data confirm previous correlation data with the computerized battery, yet illustrate remaining challenges for neurocognitive screening. PMID:21877204

The equivalence of computerized and paper-and-pencil psychological instruments: implications for measures of negative affect.

PubMed

Schulenberg, S E; Yutrzenka, B A

1999-05-01

The use of computerized psychological assessment is a growing practice among contemporary mental health professionals. Many popular and frequently used paper-and-pencil instruments have been adapted into computerized versions. Although equivalence for many instruments has been evaluated and supported, this issue is far from resolved. This literature review deals with recent research findings that suggest that computer aversion negatively impacts computerized assessment, particularly as it relates to measures of negative affect. There is a dearth of equivalence studies that take into account computer aversion's potential impact on the measurement of negative affect. Recommendations are offered for future research in this area.

Computerized symbolic manipulation in structural mechanics Progress and potential

NASA Technical Reports Server (NTRS)

Noor, A. K.; Andersen, C. M.

1978-01-01

Status and recent applications of computerized symbolic manipulation to structural mechanics problems are summarized. The applications discussed include; (1) generation of characteristic arrays of finite elements; (2) evaluation of effective stiffness and mass coefficients of continuum models for repetitive lattice structures; and (3) application of Rayleigh-Ritz technique to free vibration analysis of laminated composite elliptic plates. The major advantages of using computerized symbolic manipulation in each of these applications are outlined. A number of problem areas which limit the realization of the full potential of computerized symbolic manipulation in structural mechanics are examined and some of the means of alleviating them are discussed.

A multiresolution inversion for imaging the ionosphere

NASA Astrophysics Data System (ADS)

Yin, Ping; Zheng, Ya-Nan; Mitchell, Cathryn N.; Li, Bo

2017-06-01

Ionospheric tomography has been widely employed in imaging the large-scale ionospheric structures at both quiet and storm times. However, the tomographic algorithms to date have not been very effective in imaging of medium- and small-scale ionospheric structures due to limitations of uneven ground-based data distributions and the algorithm itself. Further, the effect of the density and quantity of Global Navigation Satellite Systems data that could help improve the tomographic results for the certain algorithm remains unclear in much of the literature. In this paper, a new multipass tomographic algorithm is proposed to conduct the inversion using intensive ground GPS observation data and is demonstrated over the U.S. West Coast during the period of 16-18 March 2015 which includes an ionospheric storm period. The characteristics of the multipass inversion algorithm are analyzed by comparing tomographic results with independent ionosonde data and Center for Orbit Determination in Europe total electron content estimates. Then, several ground data sets with different data distributions are grouped from the same data source in order to investigate the impact of the density of ground stations on ionospheric tomography results. Finally, it is concluded that the multipass inversion approach offers an improvement. The ground data density can affect tomographic results but only offers improvements up to a density of around one receiver every 150 to 200 km. When only GPS satellites are tracked there is no clear advantage in increasing the density of receivers beyond this level, although this may change if multiple constellations are monitored from each receiving station in the future.

Computed tomographic contrast tenography of the digital flexor tendon sheath of the equine hindlimb.

PubMed

Agass, Rachel; Dixon, Jonathon; Fraser, Barny

2018-05-01

Pre-surgical investigation of digital flexor tendon sheath pathology remains challenging with current standard imaging techniques. The aim of this prospective, anatomical, pilot study was to describe the anatomy of the equine hind limb digital flexor tendon sheath using a combination of computed tomography (CT) and computed tomographic contrast tenography in clinically normal cadaver limbs. Ten pairs of hind limbs with no external abnormalities were examined from the level of the tarsometatarsal joint distally. Limbs initially underwent non-contrast CT examination using 120 kVp, 300 mAs, and 1.5 mm slice thickness. Sixty millilitres of ioversol iodinated contrast media and saline (final concentration 100 mg/ml) were injected using a basilar sesamoidean approach. The computed tomographic contrast tenography examination was then repeated, before dissection of the specimens to compare gross and imaging findings. The combined CT and computed tomographic contrast tenography examinations provided excellent anatomical detail of intra-thecal structures. The borders of the superficial and deep digital flexor tendons, and the manica flexoria were consistently identifiable in all limbs. Detailed anatomy including that of the mesotenons, two of which are previously undescribed, and the plantar annular ligament were also consistently identifiable. Dissection of all 10 pairs of limbs revealed there to be no pathology, in accordance with the imaging findings. In conclusion, the combination of CT and computed tomographic contrast tenography may be useful adjunctive diagnostic techniques to define digital flexor tendon sheath pathology prior to surgical exploration in horses. © 2017 American College of Veterinary Radiology.

Sparsity Aware Adaptive Radar Sensor Imaging in Complex Scattering Environments

DTIC Science & Technology

2015-06-15

while meeting the requirement on the peak to average power ratio. Third, we study impact of waveform encoding on nonlinear electromagnetic tomographic...Enyue Lu. Time Domain Electromagnetic Tomography Using Propagation and Backpropagation Method, IEEE International Conference on Image Processing...Received Paper 3.00 4.00 Yuanwei Jin, Chengdon Dong, Enyue Lu. Waveform Encoding for Nonlinear Electromagnetic Tomographic Imaging, IEEE Global

An Analysis for Capital Expenditure Decisions at a Naval Regional Medical Center.

DTIC Science & Technology

1981-12-01

Service Equipment Review Committee 1. Portable defibrilator Computed tomographic scanner and cardioscope 2. ECG cart Automated blood cell counter 3. Gas...system sterilizer Gas system sterilizer 4. Automated blood cell Portable defibrilator and counter cardioscope 5. Computed tomographic ECG cart scanner...dictating and automated typing) systems. e. Filing equipment f. Automatic data processing equipment including data communications equipment. g

Analysis of 21-cm tomographic data

NASA Astrophysics Data System (ADS)

Mellema, Garrelt; Giri, Sambit; Ghara, Raghuna

2018-05-01

The future SKA1-Low radio telescope will be powerful enough to produce tomographic images of the 21-cm signal from the Epoch of Reionization. Here we address how to identify ionized regions in such data sets, taking into account the resolution and noise levels associated with SKA1-Low. We describe three methods of which one, superpixel oversegmentation, consistently performs best.

Research in Image Understanding as Applied to 3-D Microwave Tomographic Imaging with Near Optical Resolution.

DTIC Science & Technology

1986-03-10

and P. Frangos , "Inverse Scattering for Dielectric Media", Annual OSA Meeting, Wash. D.C., Oct. 1985. Invited Presentations 1. N. Farhat, "Tomographic...Optical Computing", DARPA Briefing, ~~April 1985. ... -7--.. , 1% If .% P . .% .% *-. 7777~14e 7-7. K-7 77 Theses 0 P.V. Frangos , "The Electromagnetic

Volume Segmentation and Ghost Particles

NASA Astrophysics Data System (ADS)

Ziskin, Isaac; Adrian, Ronald

2011-11-01

Volume Segmentation Tomographic PIV (VS-TPIV) is a type of tomographic PIV in which images of particles in a relatively thick volume are segmented into images on a set of much thinner volumes that may be approximated as planes, as in 2D planar PIV. The planes of images can be analysed by standard mono-PIV, and the volume of flow vectors can be recreated by assembling the planes of vectors. The interrogation process is similar to a Holographic PIV analysis, except that the planes of image data are extracted from two-dimensional camera images of the volume of particles instead of three-dimensional holographic images. Like the tomographic PIV method using the MART algorithm, Volume Segmentation requires at least two cameras and works best with three or four. Unlike the MART method, Volume Segmentation does not require reconstruction of individual particle images one pixel at a time and it does not require an iterative process, so it operates much faster. As in all tomographic reconstruction strategies, ambiguities known as ghost particles are produced in the segmentation process. The effect of these ghost particles on the PIV measurement is discussed. This research was supported by Contract 79419-001-09, Los Alamos National Laboratory.

Creating three-dimensional tooth models from tomographic images.

PubMed

Lima da Silva, Isaac Newton; Barbosa, Gustavo Frainer; Soares, Rodrigo Borowski Grecco; Beltrao, Maria Cecilia Gomes; Spohr, Ana Maria; Mota, Eduardo Golcalves; Oshima, Hugo Mitsuo Silva; Burnett, Luiz Henrique

2008-01-01

The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur. Sharp cusps and faceted contour can produce stress concentrations, which are incoherent with the reality. The aim of this study was the processing of tomographic images in order to develop an advanced three-dimensional reconstruction of the anatomy of a molar tooth and the integration of the resulting solid with commercially available CAD/CAE software. Computed tomographic images were obtained from 0.5 mm thick slices of mandibular molar and transferred to commercial cad software. Once the point cloud data have been generated, the work on these points started to get to the solid model of the tooth with Pro/Engineer software. The obtained tooth model showed very accurate shape and dimensions, as it was obtained from real tooth data with error of 0.0 to -0.8 mm. The methodology presented was efficient for creating a biomodel of a tooth from tomographic images that realistically represented its anatomy.

Experimental demonstration of laser tomographic adaptive optics on a 30-meter telescope at 800 nm

NASA Astrophysics Data System (ADS)

Ammons, S., Mark; Johnson, Luke; Kupke, Renate; Gavel, Donald T.; Max, Claire E.

2010-07-01

A critical goal in the next decade is to develop techniques that will extend Adaptive Optics correction to visible wavelengths on Extremely Large Telescopes (ELTs). We demonstrate in the laboratory the highly accurate atmospheric tomography necessary to defeat the cone effect on ELTs, an essential milestone on the path to this capability. We simulate a high-order Laser Tomographic AO System for a 30-meter telescope with the LTAO/MOAO testbed at UCSC. Eight Sodium Laser Guide Stars (LGSs) are sensed by 99x99 Shack-Hartmann wavefront sensors over 75". The AO system is diffraction-limited at a science wavelength of 800 nm (S ~ 6-9%) over a field of regard of 20" diameter. Openloop WFS systematic error is observed to be proportional to the total input atmospheric disturbance and is nearly the dominant error budget term (81 nm RMS), exceeded only by tomographic wavefront estimation error (92 nm RMS). The total residual wavefront error for this experiment is comparable to that expected for wide-field tomographic adaptive optics systems of similar wavefront sensor order and LGS constellation geometry planned for Extremely Large Telescopes.

Scalp marking for a craniotomy using a laser pointer during preoperative computed tomographic imaging: technical note.

PubMed

Kubo, S; Nakata, H; Sugauchi, Y; Yokota, N; Yoshimine, T

2000-05-01

The preoperative localization of superficial intracranial lesions is often necessary for accurate burr hole placement or craniotomy siting. It is not always easy, however, to localize the lesions over the scalp working only from computed tomographic images. We developed a simple method for such localization using a laser pointer during the preoperative computed tomographic examination. The angle of incidence, extending from a point on the scalp to the center of the computed tomographic image, is measured by the software included with the scanner. In the gantry, at the same angle as on the image, a laser is beamed from a handmade projector onto the patient's scalp toward the center of the gantry. The point illuminated on the patient's head corresponds to that on the image. The device and the method are described in detail herein. We applied this technique to mark the area for the craniotomy before surgery in five patients with superficial brain tumors. At the time of surgery, it was confirmed that the tumors were circumscribed precisely. The technique is easy to perform and useful in the preoperative planning for a craniotomy. In addition, the device is easily constructed and inexpensive.

Optical coherence tomography using images of hair structure and dyes penetrating into the hair.

PubMed

Tsugita, Tetsuya; Iwai, Toshiaki

2014-11-01

Hair dyes are commonly evaluated by the appearance of the hair after dyeing. However, this approach cannot simultaneously assess how deep the dye has penetrated into hair. For simultaneous assessment of the appearance and the interior of hair, we developed a visible-range red, green, and blue (RGB) (three primary colors)-optical coherence tomography (OCT) using an RGB LED light source. We then evaluated a phantom model based on the assumption that the sample's absorbability in the vertical direction affects the tomographic imaging. Consistent with theory, our device showed higher resolution than conventional OCT with far-red light. In the experiment on the phantom model, we confirmed that the tomographic imaging is affected by absorbability unique to the sample. Furthermore, we verified that permeability can be estimated from this tomographic image. We also identified for the first time the relationship between penetration of the dye into hair and characteristics of wavelength by tomographic imaging of dyed hair. We successfully simultaneously assessed the appearance of dyed hair and inward penetration of the dye without preparing hair sections. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

TomoBank: a tomographic data repository for computational x-ray science

NASA Astrophysics Data System (ADS)

De Carlo, Francesco; Gürsoy, Doğa; Ching, Daniel J.; Joost Batenburg, K.; Ludwig, Wolfgang; Mancini, Lucia; Marone, Federica; Mokso, Rajmund; Pelt, Daniël M.; Sijbers, Jan; Rivers, Mark

2018-03-01

There is a widening gap between the fast advancement of computational methods for tomographic reconstruction and their successful implementation in production software at various synchrotron facilities. This is due in part to the lack of readily available instrument datasets and phantoms representative of real materials for validation and comparison of new numerical methods. Recent advancements in detector technology have made sub-second and multi-energy tomographic data collection possible (Gibbs et al 2015 Sci. Rep. 5 11824), but have also increased the demand to develop new reconstruction methods able to handle in situ (Pelt and Batenburg 2013 IEEE Trans. Image Process. 22 5238-51) and dynamic systems (Mohan et al 2015 IEEE Trans. Comput. Imaging 1 96-111) that can be quickly incorporated in beamline production software (Gürsoy et al 2014 J. Synchrotron Radiat. 21 1188-93). The x-ray tomography data bank, tomoBank, provides a repository of experimental and simulated datasets with the aim to foster collaboration among computational scientists, beamline scientists, and experimentalists and to accelerate the development and implementation of tomographic reconstruction methods for synchrotron facility production software by providing easy access to challenging datasets and their descriptors.

Tomographic imaging using poissonian detector data

DOEpatents

Aspelmeier, Timo; Ebel, Gernot; Hoeschen, Christoph

2013-10-15

An image reconstruction method for reconstructing a tomographic image (f.sub.j) of a region of investigation within an object (1), comprises the steps of providing detector data (y.sub.i) comprising Poisson random values measured at an i-th of a plurality of different positions, e.g. i=(k,l) with pixel index k on a detector device and angular index l referring to both the angular position (.alpha..sub.l) and the rotation radius (r.sub.l) of the detector device (10) relative to the object (1), providing a predetermined system matrix A.sub.ij assigning a j-th voxel of the object (1) to the i-th detector data (y.sub.i), and reconstructing the tomographic image (f.sub.j) based on the detector data (y.sub.i), said reconstructing step including a procedure of minimizing a functional F(f) depending on the detector data (y.sub.i) and the system matrix A.sub.ij and additionally including a sparse or compressive representation of the object (1) in an orthobasis T, wherein the tomographic image (f.sub.j) represents the global minimum of the functional F(f). Furthermore, an imaging method and an imaging device using the image reconstruction method are described.

45 CFR 310.30 - Under what circumstances would FFP be suspended or disallowed in the costs of Computerized Tribal...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Under what circumstances would FFP be suspended or... SYSTEMS AND OFFICE AUTOMATION Funding for Computerized Tribal IV-D Systems and Office Automation § 310.30 Under what circumstances would FFP be suspended or disallowed in the costs of Computerized Tribal IV-D...

Computerized Biomechanical Man-Model

DTIC Science & Technology

1976-07-01

Force Systems Command Wright-Patterson AFB, Ohio ABSTRACT The COMputerized BIomechanical MAN-Model (called COMBIMAN) is a computer interactive graphics...concept was to build a mock- The use of mock-ups for biomechanical evalua- up which permitted the designer to visualize the tion has long been a tool...of the can become an obstacle to design change. Aerospace Medical Research Laboratory, we are developing a computerized biomechanical man-model

The Neurological Basis and Potential Modification of Emotional Intelligence through Affective/Behavioral Training

DTIC Science & Technology

2010-10-01

facial trustworthiness; facial displays of anger) presented subliminally . Furthermore, the responsiveness of these regions to subliminal stimulation ...develop, or program the computerized stimulation paradigms for use during functional neuroimaging (i.e., MJT; BMAT; EFAT). These paradigms will be...programming began on the computerized functional MRI stimulation paradigms using e-prime software. • Quarter #2: Programming of all computerized functional

Multimodal Intervention Trial for Cognitive Deficits in Neurofibromatosis Type 1: Efficacy of Computerized Cognitive Training and Stimulant Medication

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-15-1-0508 TITLE: Multimodal Intervention Trial for Cognitive Deficits in Neurofibromatosis Type 1: Efficacy of...Computerized Cognitive Training and Stimulant Medication PRINCIPAL INVESTIGATOR: Maria T. Acosta, M.D. CONTRACTING ORGANIZATION: Children’s National Health...database. 15. SUBJECT TERMS Neurofibromatosis, cognition , pediatric, computerized training programs, working memory 16. SECURITY CLASSIFICATION OF: 17

Computerized Memory Training Leads to Sustained Improvement in Visuospatial Short-Term Memory Skills in Children with Down Syndrome

ERIC Educational Resources Information Center

Bennett, Stephanie J.; Holmes, Joni; Buckley, Sue

2013-01-01

This study evaluated the impact of a computerized visuospatial memory training intervention on the memory and behavioral skills of children with Down syndrome. Teaching assistants were trained to support the delivery of a computerized intervention program to individual children over a 10-16 week period in school. Twenty-one children aged 7-12…

A Study on the Implementation of the Ecotran Systems, Inc. Computerized Routing and Scheduling Pupil Transportation System. San Diego Unified School District, Superintendent's Organizational Study Team.

ERIC Educational Resources Information Center

Carriedo, Ruben; And Others

The San Diego Unified School District (California) began operating a computerized routing and scheduling system for its pupil transportation services at the beginning of the 1985-86 academic school year. The computerized system, provided by Ecotran Systems, Inc. (ECO) of Cleveland, Ohio experienced an inordinate number of difficulties. A…

Using artificial neural networks (ANN) for open-loop tomography

NASA Astrophysics Data System (ADS)

Osborn, James; De Cos Juez, Francisco Javier; Guzman, Dani; Butterley, Timothy; Myers, Richard; Guesalaga, Andres; Laine, Jesus

2011-09-01

The next generation of adaptive optics (AO) systems require tomographic techniques in order to correct for atmospheric turbulence along lines of sight separated from the guide stars. Multi-object adaptive optics (MOAO) is one such technique. Here, we present a method which uses an artificial neural network (ANN) to reconstruct the target phase given off-axis references sources. This method does not require any input of the turbulence profile and is therefore less susceptible to changing conditions than some existing methods. We compare our ANN method with a standard least squares type matrix multiplication method (MVM) in simulation and find that the tomographic error is similar to the MVM method. In changing conditions the tomographic error increases for MVM but remains constant with the ANN model and no large matrix inversions are required.

String-averaging incremental subgradients for constrained convex optimization with applications to reconstruction of tomographic images

NASA Astrophysics Data System (ADS)

Massambone de Oliveira, Rafael; Salomão Helou, Elias; Fontoura Costa, Eduardo

2016-11-01

We present a method for non-smooth convex minimization which is based on subgradient directions and string-averaging techniques. In this approach, the set of available data is split into sequences (strings) and a given iterate is processed independently along each string, possibly in parallel, by an incremental subgradient method (ISM). The end-points of all strings are averaged to form the next iterate. The method is useful to solve sparse and large-scale non-smooth convex optimization problems, such as those arising in tomographic imaging. A convergence analysis is provided under realistic, standard conditions. Numerical tests are performed in a tomographic image reconstruction application, showing good performance for the convergence speed when measured as the decrease ratio of the objective function, in comparison to classical ISM.

Computerized tomography versus magnetic resonance imaging: a comparative study in hypothalamic-pituitary and parasellar pathology.

PubMed

Webb, S M; Ruscalleda, J; Schwarzstein, D; Calaf-Alsina, J; Rovira, A; Matos, G; Puig-Domingo, M; de Leiva, A

1992-05-01

We wished to analyse the relative value of computerized tomography and magnetic resonance in patients referred for evaluation of pituitary and parasellar lesions. We performed a separate evaluation by two independent neuroradiologists of computerized tomography and magnetic resonance images ordered numerically and anonymously, with no clinical data available. We studied 40 patients submitted for hypothalamic-pituitary study; 31 were carried out preoperatively, of which histological confirmation later became available in 14. The remaining nine patients were evaluated postoperatively. Over 40 parameters relating to the bony margins, cavernous sinuses, carotid arteries, optic chiasm, suprasellar cisterns, pituitary, pituitary stalk and extension of the lesion were evaluated. These reports were compared with the initial ones offered when the scans were ordered, and with the final diagnosis. Concordance between initial computerized tomography and magnetic resonance was observed in 27 cases (67.5%); among the discordant cases computerized tomography showed the lesion in two, magnetic resonance in 10, while in the remaining case reported to harbour a microadenoma on computerized tomography the differential diagnosis between a true TSH-secreting microadenoma and pituitary resistance to thyroid hormones is still unclear. Both neuroradiologists coincided in their reports in 32 patients (80%); when the initial report was compared with those of the neuroradiologists, concordance was observed with at least one of them in 34 instances (85%). Discordant results were observed principally in microadenomas secreting ACTH or PRL and in delayed puberty. In the eight patients with Cushing's disease (histologically confirmed in six) magnetic resonance was positive in five and computerized tomography in two; the abnormal image correctly identified the side of the lesion at surgery. In patients referred for evaluation of Cushing's syndrome or hyperprolactinaemia (due to microadenomas) or after surgery, magnetic resonance is clearly preferable to computerized tomography. In macroadenomas both scans are equally diagnostic but magnetic resonance offers more information on pituitary morphology and neighbouring structures. Nevertheless, there are cases in which the results of computerized tomography and magnetic resonance will complement each other, since different parameters are analysed with each examination and discordant results are encountered.

Surface Model and Tomographic Archive of Fossil Primate and Other Mammal Holotype and Paratype Specimens of the Ditsong National Museum of Natural History, Pretoria, South Africa.

PubMed

Adams, Justin W; Olah, Angela; McCurry, Matthew R; Potze, Stephany

2015-01-01

Nearly a century of paleontological excavation and analysis from the cave deposits of the Cradle of Humankind UNESCO World Heritage Site in northeastern South Africa underlies much of our understanding of the evolutionary history of hominins, other primates and other mammal lineages in the late Pliocene and early Pleistocene of Africa. As one of few designated fossil repositories, the Plio-Pleistocene Palaeontology Section of the Ditsong National Museum of Natural History (DNMNH; the former Transvaal Museum) curates much of the mammalian faunas recovered from the fossil-rich deposits of major South African hominin-bearing localities, including the holotype and paratype specimens of many primate, carnivore, and other mammal species (Orders Primates, Carnivora, Artiodactyla, Eulipotyphla, Hyracoidea, Lagomorpha, Perissodactyla, and Proboscidea). Here we describe an open-access digital archive of high-resolution, full-color three-dimensional (3D) surface meshes of all 89 non-hominin holotype, paratype and significant mammalian specimens curated in the Plio-Pleistocene Section vault. Surface meshes were generated using a commercial surface scanner (Artec Spider, Artec Group, Luxembourg), are provided in formats that can be opened in both open-source and commercial software, and can be readily downloaded either via an online data repository (MorphoSource) or via direct request from the DNMNH. In addition to providing surface meshes for each specimen, we also provide tomographic data (both computerized tomography [CT] and microfocus [microCT]) for a subset of these fossil specimens. This archive of the DNMNH Plio-Pleistocene collections represents the first research-quality 3D datasets of African mammal fossils to be made openly available. This simultaneously provides the paleontological community with essential baseline information (e.g., updated listing and 3D record of specimens in their current state of preservation) and serves as a single resource of high-resolution digital data that improves collections accessibility, reduces unnecessary duplication of efforts by researchers, and encourages ongoing imaging-based paleobiological research across a range of South African non-hominin fossil faunas. Because the types, paratypes, and key specimens include globally-distributed mammal taxa, this digital archive not only provides 3D morphological data on taxa fundamental to Neogene and Quaternary South African palaeontology, but also lineages critical to research on African, other Old World, and New World paleocommunities. With such a broader impact of the DNMNH 3D data, we hope that establishing open access to this digital archive will encourage other researchers and institutions to provide similar resources that increase accessibility to paleontological collections and support advanced paleobiological analyses.

3D galaxy clustering with future wide-field surveys: Advantages of a spherical Fourier-Bessel analysis

NASA Astrophysics Data System (ADS)

Lanusse, F.; Rassat, A.; Starck, J.-L.

2015-06-01

Context. Upcoming spectroscopic galaxy surveys are extremely promising to help in addressing the major challenges of cosmology, in particular in understanding the nature of the dark universe. The strength of these surveys, naturally described in spherical geometry, comes from their unprecedented depth and width, but an optimal extraction of their three-dimensional information is of utmost importance to best constrain the properties of the dark universe. Aims: Although there is theoretical motivation and novel tools to explore these surveys using the 3D spherical Fourier-Bessel (SFB) power spectrum of galaxy number counts Cℓ(k,k'), most survey optimisations and forecasts are based on the tomographic spherical harmonics power spectrum C(ij)_ℓ. The goal of this paper is to perform a new investigation of the information that can be extracted from these two analyses in the context of planned stage IV wide-field galaxy surveys. Methods: We compared tomographic and 3D SFB techniques by comparing the forecast cosmological parameter constraints obtained from a Fisher analysis. The comparison was made possible by careful and coherent treatment of non-linear scales in the two analyses, which makes this study the first to compare 3D SFB and tomographic constraints on an equal footing. Nuisance parameters related to a scale- and redshift-dependent galaxy bias were also included in the computation of the 3D SFB and tomographic power spectra for the first time. Results: Tomographic and 3D SFB methods can recover similar constraints in the absence of systematics. This requires choosing an optimal number of redshift bins for the tomographic analysis, which we computed to be N = 26 for zmed ≃ 0.4, N = 30 for zmed ≃ 1.0, and N = 42 for zmed ≃ 1.7. When marginalising over nuisance parameters related to the galaxy bias, the forecast 3D SFB constraints are less affected by this source of systematics than the tomographic constraints. In addition, the rate of increase of the figure of merit as a function of median redshift is higher for the 3D SFB method than for the 2D tomographic method. Conclusions: Constraints from the 3D SFB analysis are less sensitive to unavoidable systematics stemming from a redshift- and scale-dependent galaxy bias. Even for surveys that are optimised with tomography in mind, a 3D SFB analysis is more powerful. In addition, for survey optimisation, the figure of merit for the 3D SFB method increases more rapidly with redshift, especially at higher redshifts, suggesting that the 3D SFB method should be preferred for designing and analysing future wide-field spectroscopic surveys. CosmicPy, the Python package developed for this paper, is freely available at https://cosmicpy.github.io. Appendices are available in electronic form at http://www.aanda.org

Mixed results in the safety performance of computerized physician order entry.

PubMed

Metzger, Jane; Welebob, Emily; Bates, David W; Lipsitz, Stuart; Classen, David C

2010-04-01

Computerized physician order entry is a required feature for hospitals seeking to demonstrate meaningful use of electronic medical record systems and qualify for federal financial incentives. A national sample of sixty-two hospitals voluntarily used a simulation tool designed to assess how well safety decision support worked when applied to medication orders in computerized order entry. The simulation detected only 53 percent of the medication orders that would have resulted in fatalities and 10-82 percent of the test orders that would have caused serious adverse drug events. It is important to ascertain whether actual implementations of computerized physician order entry are achieving goals such as improved patient safety.

Information technology and medication safety: what is the benefit?

PubMed Central

Kaushal, R; Bates, D

2002-01-01



 Medication errors occur frequently and have significant clinical and financial consequences. Several types of information technologies can be used to decrease rates of medication errors. Computerized physician order entry with decision support significantly reduces serious inpatient medication error rates in adults. Other available information technologies that may prove effective for inpatients include computerized medication administration records, robots, automated pharmacy systems, bar coding, "smart" intravenous devices, and computerized discharge prescriptions and instructions. In outpatients, computerization of prescribing and patient oriented approaches such as personalized web pages and delivery of web based information may be important. Public and private mandates for information technology interventions are growing, but further development, application, evaluation, and dissemination are required. PMID:12486992

Characterization of the LBNL PEM Camera

NASA Astrophysics Data System (ADS)

Wang, G.-C.; Huber, J. S.; Moses, W. W.; Qi, J.; Choong, W.-S.

2006-06-01

We present the tomographic images and performance measurements of the LBNL positron emission mammography (PEM) camera, a specially designed positron emission tomography (PET) camera that utilizes PET detector modules with depth of interaction measurement capability to achieve both high sensitivity and high resolution for breast cancer detection. The camera currently consists of 24 detector modules positioned as four detector banks to cover a rectangular patient port that is 8.2/spl times/6 cm/sup 2/ with a 5 cm axial extent. Each LBNL PEM detector module consists of 64 3/spl times/3/spl times/30 mm/sup 3/ LSO crystals coupled to a single photomultiplier tube (PMT) and an 8/spl times/8 silicon photodiode array (PD). The PMT provides accurate timing, the PD identifies the crystal of interaction, the sum of the PD and PMT signals (PD+PMT) provides the total energy, and the PD/(PD+PMT) ratio determines the depth of interaction. The performance of the camera has been evaluated by imaging various phantoms. The full-width-at-half-maximum (FWHM) spatial resolution changes slightly from 1.9 mm to 2.1 mm when measured at the center and corner of the field of the view, respectively, using a 6 ns coincidence timing window and a 300-750 keV energy window. With the same setup, the peak sensitivity of the camera is 1.83 kcps//spl mu/Ci.

Full-field OCT: applications in ophthalmology

NASA Astrophysics Data System (ADS)

Grieve, Kate; Dubois, Arnaud; Paques, Michel; Le Gargasson, Jean-Francois; Boccara, Albert C.

2005-04-01

We present images of ocular tissues obtained using ultrahigh resolution full-field OCT. The experimental setup is based on the Linnik interferometer, illuminated by a tungsten halogen lamp. En face tomographic images are obtained in real-time without scanning by computing the difference of two phase-opposed interferometric images recorded by a high-resolution CCD camera. A spatial resolution of 0.7 μm × 0.9 μm (axial × transverse) is achieved thanks to the short source coherence length and the use of high numerical aperture microscope objectives. A detection sensitivity of 90 dB is obtained by means of image averaging and pixel binning. Whole unfixed eyes and unstained tissue samples (cornea, lens, retina, choroid and sclera) of ex vivo rat, mouse, rabbit and porcine ocular tissues were examined. The unprecedented resolution of our instrument allows cellular-level resolution in the cornea and retina, and visualization of individual fibers in the lens. Transcorneal lens imaging was possible in all animals, and in albino animals, transscleral retinal imaging was achieved. We also introduce our rapid acquisition full-field optical coherence tomography system designed to accommodate in vivo ophthalmologic imaging. The variations on the original system technology include the introduction of a xenon arc lamp as source, and rapid image acquisition performed by a high-speed CMOS camera, reducing acquisition time to 5 ms per frame.

Clinical combination of multiphoton tomography and high frequency ultrasound imaging for evaluation of skin diseases

NASA Astrophysics Data System (ADS)

König, K.; Speicher, M.; Koehler, M. J.; Scharenberg, R.; Elsner, P.; Kaatz, M.

2010-02-01

For the first time, high frequency ultrasound imaging, multiphoton tomography, and dermoscopy were combined in a clinical study. Different dermatoses such as benign and malign skin cancers, connective tissue diseases, inflammatory skin diseases and autoimmune bullous skin diseases have been investigated with (i) state-of-the-art and highly sophisticated ultrasound systems for dermatology, (ii) the femtosecond-laser multiphoton tomograph DermaInspectTM and (iii) dermoscopes. Dermoscopy provides two-dimensional color imaging of the skin surface with a magnification up to 70x. Ultrasound images are generated from reflections of the emitted ultrasound signal, based on inhomogeneities of the tissue. These echoes are converted to electrical signals. Depending on the ultrasound frequency the penetration depth varies from about 1 mm to 16 mm in dermatological application. The 100-MHz-ultrasound system provided an axial resolution down to 16 μm and a lateral resolution down to 32 μm. In contrast to the wide-field ultrasound images, multiphoton tomography provided horizontal optical sections of 0.36×0.36 mm2 down to 200 μm tissue depth with submicron resolution. The autofluorescence of mitochondrial coenzymes, melanin, and elastin as well as the secondharmonic- generation signal of the collagen network were imaged. The combination of ultrasound and multiphoton tomography provides a novel opportunity for diagnostics of skin disorders.

Fixture-abutment connection surface and micro-gap measurements by 3D micro-tomographic technique analysis.

PubMed

Meleo, Deborah; Baggi, Luigi; Di Girolamo, Michele; Di Carlo, Fabio; Pecci, Raffaella; Bedini, Rossella

2012-01-01

X-ray micro-tomography (micro-CT) is a miniaturized form of conventional computed axial tomography (CAT) able to investigate small radio-opaque objects at a-few-microns high resolution, in a non-destructive, non-invasive, and tri-dimensional way. Compared to traditional optical and electron microscopy techniques, which provide two-dimensional images, this innovative investigation technology enables a sample tri-dimensional analysis without cutting, coating or exposing the object to any particular chemical treatment. X-ray micro-tomography matches ideal 3D microscopy features: the possibility of investigating an object in natural conditions and without any preparation or alteration; non-invasive, non-destructive, and sufficiently magnified 3D reconstruction; reliable measurement of numeric data of the internal structure (morphology, structure and ultra-structure). Hence, this technique has multi-fold applications in a wide range of fields, not only in medical and odontostomatologic areas, but also in biomedical engineering, materials science, biology, electronics, geology, archaeology, oil industry, and semi-conductors industry. This study shows possible applications of micro-CT in dental implantology to analyze 3D micro-features of dental implant to abutment interface. Indeed, implant-abutment misfit is known to increase mechanical stress on connection structures and surrounding bone tissue. This condition may cause not only screw preload loss or screw fracture, but also biological issues in peri-implant tissues.

Coherence imaging for ion temperature and flow measurements in a low-temperature helicon plasma source

NASA Astrophysics Data System (ADS)

Lester, R.; Zhai, Y.; Corr, C.; Howard, J.

2016-02-01

This paper describes a coherence imaging system designed for spectroscopic Doppler measurements of ion light in a low-temperature (T e   <  10 eV) helicon-produced argon plasma. Observation of the very small Doppler broadening of the Ar II 488 nm emission line requires very high spectral resolution, or equivalently, very large interferometric optical path delay (comparable with the coherence length of the emission line). For these polarization interferometers, this can only be achieved using large thicknesses (100 mm) of birefringent crystal. This poses special design challenges including the application of field-widening techniques and the development of passive thermal stabilization of the optical phase offset. We discuss the measurement principles and the optical design of these systems and present measurements of the line-integrated emissivity, and ion flow and ion temperatures along with tomographic reconstructions of the local values, for a cylindrical low temperature helicon discharge in a linear magnetized device with downstream magnetic mirror. Key results reveal a hollow edge-peaked temperature profile (central temperature  ∼0.1 eV) and sheared rigid-body rotational flows and axial flows which are comparable with the ion thermal speed. The emission line brightness, ion temperature and azimuthal ion flows are all found to increase with increased mirror magnetic field strength.

Relationship between the maxillary transverse dimension and palatally displaced canines: A cone-beam computed tomographic study.

PubMed

Hong, Wei-Hsin; Radfar, Rebecca; Chung, Chun-Hsi

2015-05-01

To examine the relationship between palatally displaced maxillary canines (PDC) and the maxillary transverse dimension using cone-beam computed tomography (CBCT). Thirty-three patients (11 males and 22 females, mean age 18.2 years) with PDC were matched to 66 patients (22 males and 44 females, mean age 18.1 years) without PDC (control) by gender, age, and posterior occlusion. A CBCT image was taken on all the patients prior to any orthodontic treatment. For each patient the maxillary basal bone widths and interdental widths at the maxillary first molars and first and second premolars were measured on axial and coronal sections of CBCT images. In addition, the presence of permanent tooth agenesis and the widths of maxillary incisors were recorded. Similar maxillary transverse dimensions, both skeletally and dentally, were found between the PDC and control groups. In the PDC group, the number of patients with permanent tooth agenesis was six times higher than in the control group. In addition, the maxillary lateral incisors on PDC-affected sides were smaller than those of control group (P < .05). The maxillary transverse dimension, both skeletally and dentally, had no effect on the occurrence of PDC. The higher prevalence of permanent tooth agenesis was found in the PDC group. Moreover, the mean mesiodistal width of maxillary lateral incisors in the PDC group was significantly smaller than in the control group (P < .05).

Mid-thigh cortical bone structural parameters, muscle mass and strength, and association with lower limb fractures in older men and women (AGES-Reykjavik Study).

PubMed

Johannesdottir, Fjola; Aspelund, Thor; Siggeirsdottir, Kristin; Jonsson, Brynjolfur Y; Mogensen, Brynjolfur; Sigurdsson, Sigurdur; Harris, Tamara B; Gudnason, Vilmundur G; Lang, Thomas F; Sigurdsson, Gunnar

2012-05-01

In a cross-sectional study we investigated the relationship between muscle and bone parameters in the mid-thigh in older people using data from a single axial computed tomographic section through the mid-thigh. Additionally, we studied the association of these variables with incident low-trauma lower limb fractures. A total of 3,762 older individuals (1,838 men and 1,924 women), aged 66-96 years, participants in the AGES-Reykjavik study, were studied. The total cross-sectional muscular area and knee extensor strength declined with age similarly in both sexes. Muscle parameters correlated most strongly with cortical area and total shaft area (adjusted for age, height, and weight) but explained <10 % of variability in those bone parameters. The increment in medullary area (MA) and buckling ratio (BR) with age was almost fourfold greater in women than men. The association between MA and muscle parameters was nonsignificant. During a median follow-up of 5.3 years, 113 women and 66 men sustained incident lower limb fractures. Small muscular area, low knee extensor strength, large MA, low cortical thickness, and high BR were significantly associated with fractures in both sexes. Our results show that bone and muscle loss proceed at different rates and with different gender patterns.

[Introduction of computerized anesthesia-recording systems and construction of comprehensive medical information network for patients undergoing surgery in the University of Tokyo Hospital].

PubMed

Kitamura, Takayuki; Hoshimoto, Hiroyuki; Yamada, Yoshitsugu

2009-10-01

The computerized anesthesia-recording systems are expensive and the introduction of the systems takes time and requires huge effort. Generally speaking, the efficacy of the computerized anesthesia-recording systems on the anesthetic managements is focused on the ability to automatically input data from the monitors to the anesthetic records, and tends to be underestimated. However, once the computerized anesthesia-recording systems are integrated into the medical information network, several features, which definitely contribute to improve the quality of the anesthetic management, can be developed; for example, to prevent misidentification of patients, to prevent mistakes related to blood transfusion, and to protect patients' personal information. Here we describe our experiences of the introduction of the computerized anesthesia-recording systems and the construction of the comprehensive medical information network for patients undergoing surgery in The University of Tokyo Hospital. We also discuss possible efficacy of the comprehensive medical information network for patients during surgery under anesthetic managements.

Antipsychotic treatment in schizophrenia: the role of computerized neuropsychological assessment.

PubMed

Kertzman, Semion; Reznik, Ilya; Grinspan, Haim; Weizman, Abraham; Kotler, Moshe

2008-01-01

The present study analyzes the role of neurocognitive assessment instruments in the detection of the contribution of antipsychotic treatment to cognitive functioning. Recently, a panel of experts suggested six main domains (working memory; attention/vigilance; verbal/visual learning and memory; reasoning and problem solving; speed of processing) implicated in schizophrenia-related cognitive deficits, which serve as a theoretical base for creation of real-time computerized neurocognitive batteries. The high sensitivity of computerized neuropsychological testing is based on their ability to adopt the reaction time (RT) paradigm for the assessment of brain function in a real-time regime. This testing is highly relevant for the monitoring of the cognitive effects of antipsychotics. Computerized assessment assists in the identification of state- and trait-related cognitive impairments. The optimal real-time computerized neurocognitive battery should composite balance between broad and narrow coverage of cognitive domains relevant to the beneficial effects of antipsychotics and will enable better planning of treatment and rehabilitation programs.

Tomographic Image Reconstruction Using an Interpolation Method for Tree Decay Detection

Treesearch

Hailin Feng; Guanghui Li; Sheng Fu; Xiping Wang

2014-01-01

Stress wave velocity has been traditionally regarded as an indicator of the extent of damage inside wood. This paper aimed to detect internal decay of urban trees through reconstructing tomographic image of the cross section of a tree trunk. A grid model covering the cross section area of a tree trunk was defined with some assumptions. Stress wave data were processed...

Features of Computerized Educational Games in Sciences of the Elementary Phase in Jordan from the Point of View of Specialists in Teaching Science and Computer Subjects

ERIC Educational Resources Information Center

Al Sarhan, Khaled Ali; AlZboon, Saleem Odeh; Olimat, Khalaf Mufleh; Al-Zboon, Mohammad Saleem

2013-01-01

The study aims at introducing the features of the computerized educational games in sciences at the elementary school in Jordan according to the specialists in teaching science and computer subjects, through answering some questions such as: What are the features of the computerized educational games in sciences at the elementary schools in Jordan…

The Effects of a Computerized Professional Development Program on Teachers and Students with and without Disabilities in Secondary General Education Classes

ERIC Educational Resources Information Center

Schumaker, Jean B.; Fisher, Joseph B.; Walsh, Lisa D.

2010-01-01

Effects of a computerized professional development (PD) program were investigated in two studies. For each, teachers were randomly assigned to either a Virtual Workshop (VW) group that used a computerized program for PD or to an Actual Workshop (AW) group that participated in a live PD session. In Study 1, the teachers' knowledge about and…

Health technology assessment review: Computerized glucose regulation in the intensive care unit - how to create artificial control

PubMed Central

2009-01-01

Current care guidelines recommend glucose control (GC) in critically ill patients. To achieve GC, many ICUs have implemented a (nurse-based) protocol on paper. However, such protocols are often complex, time-consuming, and can cause iatrogenic hypoglycemia. Computerized glucose regulation protocols may improve patient safety, efficiency, and nurse compliance. Such computerized clinical decision support systems (Cuss) use more complex logic to provide an insulin infusion rate based on previous blood glucose levels and other parameters. A computerized CDSS for glucose control has the potential to reduce overall workload, reduce the chance of human cognitive failure, and improve glucose control. Several computer-assisted glucose regulation programs have been published recently. In order of increasing complexity, the three main types of algorithms used are computerized flowcharts, Proportional-Integral-Derivative (PID), and Model Predictive Control (MPC). PID is essentially a closed-loop feedback system, whereas MPC models the behavior of glucose and insulin in ICU patients. Although the best approach has not yet been determined, it should be noted that PID controllers are generally thought to be more robust than MPC systems. The computerized Cuss that are most likely to emerge are those that are fully a part of the routine workflow, use patient-specific characteristics and apply variable sampling intervals. PMID:19849827

Quantitation of mandibular symphysis volume as a source of bone grafting.

PubMed

Verdugo, Fernando; Simonian, Krikor; Smith McDonald, Roberto; Nowzari, Hessam

2010-06-01

Autogenous intramembranous bone graft present several advantages such as minimal resorption and high concentration of bone morphogenetic proteins. A method for measuring the amount of bone that can be harvested from the symphysis area has not been reported in real patients. The aim of the present study was to intrasurgically quantitate the volume of the symphysis bone graft that can be safely harvested in live patients and compare it with AutoCAD (version 16.0, Autodesk, Inc., San Rafael, CA, USA) tomographic calculations. AutoCAD software program quantitated symphysis bone graft in 40 patients using computerized tomographies. Direct intrasurgical measurements were recorded thereafter and compared with AutoCAD data. The bone volume was measured at the recipient sites of a subgroup of 10 patients, 6 months post sinus augmentation. The volume of bone graft measured by AutoCAD averaged 1.4 mL (SD 0.6 mL, range: 0.5-2.7 mL). The volume of bone graft measured intrasurgically averaged 2.3 mL (SD 0.4 mL, range 1.7-2.8 mL). The statistical difference between the two measurement methods was significant. The bone volume measured at the recipient sites 6 months post sinus augmentation averaged 1.9 mL (SD 0.3 mL, range 1.3-2.6 mL) with a mean loss of 0.4 mL. AutoCAD did not overestimate the volume of bone that can be safely harvested from the mandibular symphysis. The use of the design software program may improve surgical treatment planning prior to sinus augmentation.

[Acute psychiatric pathology disclosing subcortical lesion in neuro-AIDS].

PubMed

Donnet, A; Harlé, J R; Cherif, A A; Gastaut, J A; Weiller, P J

1991-01-01

Maccario et al. described, in 1987, the case of an HIV-positive patient whose psychotic symptomatology was the expression of right centrum semi-ovale lesion. We report the case of a patient who suffered a sudden delirium, expression of a probable right lenticular cerebral toxoplasmosis. This 35-year-old male homosexual, who had no psychiatric history, suddenly developed in November 1988 the following psychiatric signs: he started to walk back and forth incessantly, he had the impression that he was the subject of the conversations of the passers-by, that all the posters and notices refer to him, and that he was God. He was admitted in a psychiatric department where the symptoms were progressively curbed by neuroleptics (cyamemazine 75 mg, and haloperidol 15 mg). The episode was not questioned by the patient, but attributed to bad eating habits. HIV-positivity had been discovered a year later (during systematic screening). A computerized tomographic (CT) scan performed subsequently to this delirium was interpreted as normal. Four weeks later the patient was referred to us. The psychiatric condition was stabilized in spite of a certain aggressiveness and the probable persistence of an underlying delirium state. Laboratory examinations showed the following: blood count revealed leukopenia (2.2 G/l) and thrombocytopenia (135 G/l; OKT4/OKT8 ratio was 0.08; CSF: normal; sputum culture evidenced the presence of pneumocystis carinii; EEG were normal. Neuropsychological symptoms concerned in particular a lack of concentration during the different tests with a definitive wavering of attention. Lexical retrieval was poor whatever the topic proposed.(ABSTRACT TRUNCATED AT 250 WORDS)

Inner ear anomalies and conductive hearing loss in children with Apert syndrome: an overlooked otologic aspect.

PubMed

Zhou, Guangwei; Schwartz, Lynn Thomas; Gopen, Quinton

2009-02-01

To identify the occurrence of inner ear structural anomalies and conductive hearing loss (CHL) in children with Apert syndrome. Retrospective review. Pediatric tertiary referral center. Twenty pediatric patients with Apert syndrome were found; all patients (38/40 ears) had inner ear anomalies. Computerized tomography of the head/temporal bone, pure-tone (including air and bone conduction) audiometry, and tympanometry. Imaging demonstrating inner ear anomalies, including malformations of the cochlea, dilated vestibule, and/or semicircular canal; audiologic findings of air-bone gap(s). Hearing loss was found in 90% of the patients with Apert syndrome, and 80% of them had CHL. Air-bone gaps were found at all frequencies, with larger gaps at low frequencies. Fifty percent (20/40) of the ears had better than 0 dB hearing level bone conduction thresholds at 250 and/or 500 Hz. Normal middle ear pressure and mobility were found in all ears with intact eardrum. Inner ear anomalies were found in all patients, and 90% of them had bilateral involvement. Most frequently observed inner ear anomalies were dilated vestibule, malformed lateral semicircular canal, and cochlear dysplasia. Children with Apert syndrome may present with significant CHL that cannot be explained by minor middle ear pathologies alone. This conductive loss may be, at least partially, attributed to the inner ear anomalies; however, these structural anomalies are usually not recognized in these patients. Failure to close air-bone gap after surgical intervention may raise the suspicion of inner ear anomalies, and computed tomographic scan of the temporal bone can provide definitive proof.

Majewski osteodysplastic primordial dwarfism type II (MOPD II): expanding the vascular phenotype.

PubMed

Bober, Michael B; Khan, Nadia; Kaplan, Jennifer; Lewis, Kristi; Feinstein, Jeffrey A; Scott, Charles I; Steinberg, Gary K

2010-04-01

Majewski Osteodysplastic Primordial Dwarfism, Type II (MOPD II) is a rare, autosomal recessive disorder. Features include severe intrauterine growth retardation (IUGR), poor postnatal growth (adult stature approximately 100 cm), severe microcephaly, skeletal dysplasia, characteristic facial features, and normal or near normal intelligence. An Institutional Review Board (IRB) approved registry was created and currently follows 25 patients with a diagnosis of MOPD II. Based on previous studies, a neurovascular screening program was implemented and 13 (52%) of these patients have been found to have cerebral neurovascular abnormalities including moyamoya angiopathy and/or intracranial aneurysms. The typical moyamoya pathogenesis begins with vessel narrowing in the supraclinoid internal carotid artery, anterior cerebral (A1) or middle cerebral (M1) artery segments. The narrowing may predominate initially on one side, progresses to bilateral stenosis, with subsequent occlusion of the vessels and collateral formation. We present four patients who, on neurovascular screening, were found to have cerebrovascular changes. Two were asymptomatic, one presented with a severe headache and projectile vomiting related to a ruptured aneurysm, and one presented after an apparent decline in cognitive functioning. Analysis of the registry suggests screening for moyamoya disease be performed at the time of MOPD II diagnosis and at least every 12-18 months using MRA or computerized tomographic angiography (CTA). We believe this is imperative. If diagnosed early enough, re-vascularization and aneurysm treatment in skilled hands can be performed safely and prevent or minimize long-term sequelae in this population. Emergent evaluation is also needed when other neurologic or cardiac symptoms are present. (c) 2010 Wiley-Liss, Inc.

Pain Perception: Computerized versus Traditional Local Anesthesia in Pediatric Patients.

PubMed

Mittal, M; Kumar, A; Srivastava, D; Sharma, P; Sharma, S

2015-01-01

Local anesthetic injection is one of the most anxiety- provoking procedure for both children and adult patients in dentistry. A computerized system for slow delivery of local anesthetic has been developed as a possible solution to reduce the pain related to the local anesthetic injection. The present study was conducted to evaluate and compare pain perception rates in pediatric patients with computerized system and traditional methods, both objectively and subjectively. It was a randomized controlled study in one hundred children aged 8-12 years in healthy physical and mental state, assessed as being cooperative, requiring extraction of maxillary primary molars. Children were divided into two groups by random sampling - Group A received buccal and palatal infiltration injection using Wand, while Group B received buccal and palatal infiltration using traditional syringe. Visual Analog scale (VAS) was used for subjective evaluation of pain perception by patient. Sound, Eye, Motor (SEM) scale was used as an objective method where sound, eye and motor reactions of patient were observed and heart rate measurement using pulse oximeter was used as the physiological parameter for objective evaluation. Patients experienced significantly less pain of injection with the computerized method during palatal infiltration, while less pain was not statistically significant during buccal infiltration. Heart rate increased during both buccal and palatal infiltration in traditional and computerized local anesthesia, but difference between traditional and computerized method was not statistically significant. It was concluded that pain perception was significantly more during traditional palatal infiltration injection as compared to computerized palatal infiltration, while there was no difference in pain perception during buccal infiltration in both the groups.

Tomographic inversion techniques incorporating physical constraints for line integrated spectroscopy in stellarators and tokamaks

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

Pablant, N. A.; Bell, R. E.; Bitter, M.

2014-11-15

Accurate tomographic inversion is important for diagnostic systems on stellarators and tokamaks which rely on measurements of line integrated emission spectra. A tomographic inversion technique based on spline optimization with enforcement of constraints is described that can produce unique and physically relevant inversions even in situations with noisy or incomplete input data. This inversion technique is routinely used in the analysis of data from the x-ray imaging crystal spectrometer (XICS) installed at the Large Helical Device. The XICS diagnostic records a 1D image of line integrated emission spectra from impurities in the plasma. Through the use of Doppler spectroscopy andmore » tomographic inversion, XICS can provide profile measurements of the local emissivity, temperature, and plasma flow. Tomographic inversion requires the assumption that these measured quantities are flux surface functions, and that a known plasma equilibrium reconstruction is available. In the case of low signal levels or partial spatial coverage of the plasma cross-section, standard inversion techniques utilizing matrix inversion and linear-regularization often cannot produce unique and physically relevant solutions. The addition of physical constraints, such as parameter ranges, derivative directions, and boundary conditions, allow for unique solutions to be reliably found. The constrained inversion technique described here utilizes a modified Levenberg-Marquardt optimization scheme, which introduces a condition avoidance mechanism by selective reduction of search directions. The constrained inversion technique also allows for the addition of more complicated parameter dependencies, for example, geometrical dependence of the emissivity due to asymmetries in the plasma density arising from fast rotation. The accuracy of this constrained inversion technique is discussed, with an emphasis on its applicability to systems with limited plasma coverage.« less

Enhanced Combined Tomography and Biomechanics Data for Distinguishing Forme Fruste Keratoconus.

PubMed

Luz, Allan; Lopes, Bernardo; Hallahan, Katie M; Valbon, Bruno; Ramos, Isaac; Faria-Correia, Fernando; Schor, Paulo; Dupps, William J; Ambrósio, Renato

2016-07-01

To evaluate the performance of the Ocular Response Analyzer (ORA) (Reichert Ophthalmic Instruments, Depew, NY) variables and Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany) tomographic parameters in differentiating forme fruste keratoconus (FFKC) from normal corneas, and to assess a combined biomechanical and tomographic parameter to improve outcomes. Seventy-six eyes of 76 normal patients and 21 eyes of 21 patients with FFKC were included in the study. Fifteen variables were derived from exported ORA signals to characterize putative indicators of biomechanical behavior and 37 ORA waveform parameters were tested. Sixteen tomographic parameters from Pentacam HR were tested. Logistic regression was used to produce a combined biomechanical and tomography linear model. Differences between groups were assessed by the Mann-Whitney U test. The area under the receiver operating characteristics curve (AUROC) was used to compare diagnostic performance. No statistically significant differences were found in age, thinnest point, central corneal thickness, and maximum keratometry between groups. Twenty-one parameters showed significant differences between the FFKC and control groups. Among the ORA waveform measurements, the best parameters were those related to the area under the first peak, p1area1 (AUROC, 0.717 ± 0.065). Among the investigator ORA variables, a measure incorporating the pressure-deformation relationship of the entire response cycle was the best predictor (hysteresis loop area, AUROC, 0.688 ± 0.068). Among tomographic parameters, Belin/Ambrósio display showed the highest predictive value (AUROC, 0.91 ± 0.057). A combination of parameters showed the best result (AUROC, 0.953 ± 0.024) outperforming individual parameters. Tomographic and biomechanical parameters demonstrated the ability to differentiate FFKC from normal eyes. A combination of both types of information further improved predictive value. [J Refract Surg. 2016;32(7):479-485.]. Copyright 2016, SLACK Incorporated.

Computed Tomographic Blend Sign Is Associated With Computed Tomographic Angiography Spot Sign and Predicts Secondary Neurological Deterioration After Intracerebral Hemorrhage.

PubMed

Sporns, Peter B; Schwake, Michael; Schmidt, Rene; Kemmling, André; Minnerup, Jens; Schwindt, Wolfram; Cnyrim, Christian; Zoubi, Tarek; Heindel, Walter; Niederstadt, Thomas; Hanning, Uta

2017-01-01

Significant early hematoma growth in patients with intracerebral hemorrhage is an independent predictor of poor functional outcome. Recently, the novel blend sign (BS) has been introduced as a new imaging sign for predicting hematoma growth in noncontrast computed tomography. Another parameter predicting increasing hematoma size is the well-established spot sign (SS) visible in computed tomographic angiography. We, therefore, aimed to clarify the association between established SS and novel BS and their values predicting a secondary neurological deterioration. Retrospective study inclusion criteria were (1) spontaneous intracerebral hemorrhage confirmed on noncontrast computed tomography and (2) noncontrast computed tomography and computed tomographic angiography performed on admission within 6 hours after onset of symptoms. We defined a binary outcome (secondary neurological deterioration versus no secondary deterioration). As secondary neurological deterioration, we defined (1) early hemicraniectomy under standardized criteria or (2) secondary decrease of Glasgow Coma Scale of >3 points, both within the first 48 hours after symptom onset. Of 182 patients with spontaneous intracerebral hemorrhage, 37 (20.3%) presented with BS and 39 (21.4%) with SS. Of the 81 patients with secondary deterioration, 31 (38.3%) had BS and SS on admission. Multivariable logistic regression analysis identified hematoma volume (odds ratio, 1.07 per mL; P≤0.001), intraventricular hemorrhage (odds ratio, 3.08; P=0.008), and the presence of BS (odds ratio, 11.47; P≤0.001) as independent predictors of neurological deterioration. The BS, which is obtainable in noncontrast computed tomography, shows a high correlation with the computed tomographic angiography SS and is a reliable predictor of secondary neurological deterioration after spontaneous intracerebral hemorrhage. © 2016 American Heart Association, Inc.

Tomographic reconstruction of heat release rate perturbations induced by helical modes in turbulent swirl flames

NASA Astrophysics Data System (ADS)

Moeck, Jonas P.; Bourgouin, Jean-François; Durox, Daniel; Schuller, Thierry; Candel, Sébastien

2013-04-01

Swirl flows with vortex breakdown are widely used in industrial combustion systems for flame stabilization. This type of flow is known to sustain a hydrodynamic instability with a rotating helical structure, one common manifestation of it being the precessing vortex core. The role of this unsteady flow mode in combustion is not well understood, and its interaction with combustion instabilities and flame stabilization remains unclear. It is therefore important to assess the structure of the perturbation in the flame that is induced by this helical mode. Based on principles of tomographic reconstruction, a method is presented to determine the 3-D distribution of the heat release rate perturbation associated with the helical mode. Since this flow instability is rotating, a phase-resolved sequence of projection images of light emitted from the flame is identical to the Radon transform of the light intensity distribution in the combustor volume and thus can be used for tomographic reconstruction. This is achieved with one stationary camera only, a vast reduction in experimental and hardware requirements compared to a multi-camera setup or camera repositioning, which is typically required for tomographic reconstruction. Different approaches to extract the coherent part of the oscillation from the images are discussed. Two novel tomographic reconstruction algorithms specifically tailored to the structure of the heat release rate perturbations related to the helical mode are derived. The reconstruction techniques are first applied to an artificial field to illustrate the accuracy. High-speed imaging data acquired in a turbulent swirl-stabilized combustor setup with strong helical mode oscillations are then used to reconstruct the 3-D structure of the associated perturbation in the flame.

Permeability Surface of Deep Middle Cerebral Artery Territory on Computed Tomographic Perfusion Predicts Hemorrhagic Transformation After Stroke.

PubMed

Li, Qiao; Gao, Xinyi; Yao, Zhenwei; Feng, Xiaoyuan; He, Huijin; Xue, Jing; Gao, Peiyi; Yang, Lumeng; Cheng, Xin; Chen, Weijian; Yang, Yunjun

2017-09-01

Permeability surface (PS) on computed tomographic perfusion reflects blood-brain barrier permeability and is related to hemorrhagic transformation (HT). HT of deep middle cerebral artery (MCA) territory can occur after recanalization of proximal large-vessel occlusion. We aimed to determine the relationship between HT and PS of deep MCA territory. We retrospectively reviewed 70 consecutive acute ischemic stroke patients presenting with occlusion of the distal internal carotid artery or M1 segment of the MCA. All patients underwent computed tomographic perfusion within 6 hours after symptom onset. Computed tomographic perfusion data were postprocessed to generate maps of different perfusion parameters. Risk factors were identified for increased deep MCA territory PS. Receiver operating characteristic curve analysis was performed to calculate the optimal PS threshold to predict HT of deep MCA territory. Increased PS was associated with HT of deep MCA territory. After adjustments for age, sex, onset time to computed tomographic perfusion, and baseline National Institutes of Health Stroke Scale, poor collateral status (odds ratio, 7.8; 95% confidence interval, 1.67-37.14; P =0.009) and proximal MCA-M1 occlusion (odds ratio, 4.12; 95% confidence interval, 1.03-16.52; P =0.045) were independently associated with increased deep MCA territory PS. Relative PS most accurately predicted HT of deep MCA territory (area under curve, 0.94; optimal threshold, 2.89). Increased PS can predict HT of deep MCA territory after recanalization therapy for cerebral proximal large-vessel occlusion. Proximal MCA-M1 complete occlusion and distal internal carotid artery occlusion in conjunction with poor collaterals elevate deep MCA territory PS. © 2017 American Heart Association, Inc.

Tomographic inversion techniques incorporating physical constraints for line integrated spectroscopy in stellarators and tokamaksa)

DOE PAGES

Pablant, N. A.; Bell, R. E.; Bitter, M.; ...

2014-08-08

Accurate tomographic inversion is important for diagnostic systems on stellarators and tokamaks which rely on measurements of line integrated emission spectra. A tomographic inversion technique based on spline optimization with enforcement of constraints is described that can produce unique and physically relevant inversions even in situations with noisy or incomplete input data. This inversion technique is routinely used in the analysis of data from the x-ray imaging crystal spectrometer (XICS) installed at LHD. The XICS diagnostic records a 1D image of line integrated emission spectra from impurities in the plasma. Through the use of Doppler spectroscopy and tomographic inversion, XICSmore » can provide pro file measurements of the local emissivity, temperature and plasma flow. Tomographic inversion requires the assumption that these measured quantities are flux surface functions, and that a known plasma equilibrium reconstruction is available. In the case of low signal levels or partial spatial coverage of the plasma cross-section, standard inversion techniques utilizing matrix inversion and linear-regularization often cannot produce unique and physically relevant solutions. The addition of physical constraints, such as parameter ranges, derivative directions, and boundary conditions, allow for unique solutions to be reliably found. The constrained inversion technique described here utilizes a modifi ed Levenberg-Marquardt optimization scheme, which introduces a condition avoidance mechanism by selective reduction of search directions. The constrained inversion technique also allows for the addition of more complicated parameter dependencies, for example geometrical dependence of the emissivity due to asymmetries in the plasma density arising from fast rotation. The accuracy of this constrained inversion technique is discussed, with an emphasis on its applicability to systems with limited plasma coverage.« less

Metric on the space of quantum states from relative entropy. Tomographic reconstruction

NASA Astrophysics Data System (ADS)

Man'ko, Vladimir I.; Marmo, Giuseppe; Ventriglia, Franco; Vitale, Patrizia

2017-08-01

In the framework of quantum information geometry, we derive, from quantum relative Tsallis entropy, a family of quantum metrics on the space of full rank, N level quantum states, by means of a suitably defined coordinate free differential calculus. The cases N=2, N=3 are discussed in detail and notable limits are analyzed. The radial limit procedure has been used to recover quantum metrics for lower rank states, such as pure states. By using the tomographic picture of quantum mechanics we have obtained the Fisher-Rao metric for the space of quantum tomograms and derived a reconstruction formula of the quantum metric of density states out of the tomographic one. A new inequality obtained for probabilities of three spin-1/2 projections in three perpendicular directions is proposed to be checked in experiments with superconducting circuits.

Microcomputer Network for Computerized Adaptive Testing (CAT): Program Listing. Supplement.

DTIC Science & Technology

1984-03-01

UMICROCOMPUTER NETWORK FOR COMPUTERIZED ADAPTIVE TESTING ( CAT ): PROGRAM LISTING in APPROVED FOR PUBLIC RELEASE;IDISTRIBUTION UNLIMITEDPs DTIC ’ Akf 3 0 1-d84...NETWORK FOR COMPUTERIZED ADAPTIVE TESTING ( CAT ).- PROGRAM LISTING , ,j Baldwin Quan Thomas A. Park Gary Sandahl John H. Wolfe Reviewed by James R. McBride A...Center San Diego, California 92152 V.% :-, CONTENTrS Page CATPROJECT.TEXT CAT system driver textfile I 1 ADMINDIR- Subdirectory - Test administration

Computerized Adaptive Screening Test (CAST): Development for Use in Military Recruiting Stations

DTIC Science & Technology

1984-01-01

testing ( CAT ) 20. ABSTRACT (Continuo on rover .. efdo II neco .. ., ond Identity bJ’ 11/oclr -llor) The Computerized Adaptive Screening Test (CAST...effort is in progress to develop a computerized adaptive testing ( CAT ) system and to evaluate its potential for use in the military entrance...U.S. Marine Corps) has been designated as lead service for CAT system development; and the Navy Personnel Research and Development Center, as lead

Application of a computerized environmental information system to master and sector planning

NASA Technical Reports Server (NTRS)

Stewart, J. C.

1978-01-01

A computerized composite mapping system developed as an aid in the land use decision making process is described. Emphasis is placed on consideration of the environment in urban planning. The presence of alluvium, shallow bedrock, surface water, and vegetation growth are among the environmental factors considered. An analysis of the Shady Grove Sector planning is presented as an example of the use of computerized composite mapping for long range planning.

The ABC's required for establishing a practical computerized plant engineering management data base system

NASA Technical Reports Server (NTRS)

Maiocco, F. R.; Hume, J. P.

1976-01-01

A system's approach is outlined in the paper to assist facility and Plant Engineers improve their organization's data management system. The six basic steps identified may appear somewhat simple; however, adequate planning, proper resources, and the involvement of management will determine the success of a computerized facility management data base. Helpful suggestions are noted throughout the paper to insure the development of a practical computerized data management system.

The Tomographic Ionized-Carbon Mapping Experiment (TIME) CII Imaging Spectrometer

NASA Astrophysics Data System (ADS)

Staniszewski, Z.; Bock, J. J.; Bradford, C. M.; Brevik, J.; Cooray, A.; Gong, Y.; Hailey-Dunsheath, S.; O'Brient, R.; Santos, M.; Shirokoff, E.; Silva, M.; Zemcov, M.

2014-09-01

The Tomographic Ionized-Carbon Mapping Experiment (TIME) and TIME-Pilot are proposed imaging spectrometers to measure reionization and large scale structure at redshifts 5-9. We seek to exploit the 158 restframe emission of [CII], which becomes measurable at 200-300 GHz at reionization redshifts. Here we describe the scientific motivation, give an overview of the proposed instrument, and highlight key technological developments underway to enable these measurements.

Tomographic Validation of the AWSoM Model of the Inner Corona During Solar Minima

NASA Astrophysics Data System (ADS)

Manchester, W.; Vásquez, A. M.; Lloveras, D. G.; Mac Cormack, C.; Nuevo, F.; Lopez-Fuentes, M.; Frazin, R. A.; van der Holst, B.; Landi, E.; Gombosi, T. I.

2017-12-01

Continuous improvement of MHD three-dimensional (3D) models of the global solar corona, such as the Alfven Wave Solar Model (AWSoM) of the Space Weather Modeling Framework (SWMF), requires testing their ability to reproduce observational constraints at a global scale. To that end, solar rotational tomography based on EUV image time-series can be used to reconstruct the 3D distribution of the electron density and temperature in the inner solar corona (r < 1.25 Rsun). The tomographic results, combined with a global coronal magnetic model, can further provide constraints on the energy input flux required at the coronal base to maintain stable structures. In this work, tomographic reconstructions are used to validate steady-state 3D MHD simulations of the inner corona using the latest version of the AWSoM model. We perform the study for selected rotations representative of solar minimum conditions, when the global structure of the corona is more axisymmetric. We analyse in particular the ability of the MHD simulation to match the tomographic results across the boundary region between the equatorial streamer belt and the surrounding coronal holes. The region is of particular interest as the plasma flow from that zone is thought to be related to the origin of the slow component of the solar wind.

CT venography: use in selecting a surgical approach for the treatment of petrous apex cholesterol granulomas.

PubMed

Isaacson, Brandon; Kutz, Joe Walter; Mendelsohn, Dianne; Roland, Peter S

2009-04-01

To demonstrate the use of computed tomographic (CT) venography in selecting a surgical approach for cholesterol granulomas. Retrospective case review. Tertiary referral center. Three patients presented with symptomatic petrous apex cholesterol granulomas with extensive bone erosion involving the jugular fossa. Computed tomographic venography was performed on each patient before selecting a surgical approach for drainage. Localization of the jugular bulb in relation to the petrous carotid artery and basal turn of the cochlea was ascertained in each subject. Three patients with large symptomatic cholesterol granulomas were identified. Conventional CT demonstrated extensive bone erosion involving the jugular fossa in each patient. The location of the jugular bulb and its proximity to the petrous carotid artery and basal turn of the cochlea could not be determined with conventional temporal bone CT and magnetic resonance imaging. Computed tomographic venography provided the exact location of the jugular bulb in all 3 patients. The favorable position of the jugular bulb in all 3 cases permitted drainage of these lesions using an infracochlear approach. Computed tomographic venography provided invaluable information in 3 patients with large symptomatic cholesterol granulomas. All 3 patients were previously thought to be unsuitable candidates for an infracochlear or infralabyrinthine approach because of the unknown location of the jugular bulb.

SSULI/SSUSI UV Tomographic Images of Large-Scale Plasma Structuring

NASA Astrophysics Data System (ADS)

Hei, M. A.; Budzien, S. A.; Dymond, K.; Paxton, L. J.; Schaefer, R. K.; Groves, K. M.

2015-12-01

We present a new technique that creates tomographic reconstructions of atmospheric ultraviolet emission based on data from the Special Sensor Ultraviolet Limb Imager (SSULI) and the Special Sensor Ultraviolet Spectrographic Imager (SSUSI), both flown on the Defense Meteorological Satellite Program (DMSP) Block 5D3 series satellites. Until now, the data from these two instruments have been used independently of each other. The new algorithm combines SSULI/SSUSI measurements of 135.6 nm emission using the tomographic technique; the resultant data product - whole-orbit reconstructions of atmospheric volume emission within the satellite orbital plane - is substantially improved over the original data sets. Tests using simulated atmospheric emission verify that the algorithm performs well in a variety of situations, including daytime, nighttime, and even in the challenging terminator regions. A comparison with ALTAIR radar data validates that the volume emission reconstructions can be inverted to yield maps of electron density. The algorithm incorporates several innovative new features, including the use of both SSULI and SSUSI data to create tomographic reconstructions, the use of an inversion algorithm (Richardson-Lucy; RL) that explicitly accounts for the Poisson statistics inherent in optical measurements, and a pseudo-diffusion based regularization scheme implemented between iterations of the RL code. The algorithm also explicitly accounts for extinction due to absorption by molecular oxygen.

Sodankylä ionospheric tomography data set 2003-2014

NASA Astrophysics Data System (ADS)

Norberg, Johannes; Roininen, Lassi; Kero, Antti; Raita, Tero; Ulich, Thomas; Markkanen, Markku; Juusola, Liisa; Kauristie, Kirsti

2016-07-01

Sodankylä Geophysical Observatory has been operating a receiver network for ionospheric tomography and collecting the produced data since 2003. The collected data set consists of phase difference curves measured from COSMOS navigation satellites from the Russian Parus network (Wood and Perry, 1980) and tomographic electron density reconstructions obtained from these measurements. In this study vertical total electron content (VTEC) values are integrated from the reconstructed electron densities to make a qualitative and quantitative analysis to validate the long-term performance of the tomographic system. During the observation period, 2003-2014, there were three to five operational stations at the Fennoscandia sector. Altogether the analysis consists of around 66 000 overflights, but to ensure the quality of the reconstructions, the examination is limited to cases with descending (north to south) overflights and maximum elevation over 60°. These constraints limit the number of overflights to around 10 000. Based on this data set, one solar cycle of ionospheric VTEC estimates is constructed. The measurements are compared against the International Reference Ionosphere (IRI)-2012 model, F10.7 solar flux index and sunspot number data. Qualitatively the tomographic VTEC estimate corresponds to reference data very well, but the IRI-2012 model results are on average 40 % higher than that of the tomographic results.

Thin-walled composite tubes using fillers subjected to quasistatic axial compression

NASA Astrophysics Data System (ADS)

AL-Qrimli, Haidar F.; Mahdi, Fadhil A.; Ismail, Firas B.; Alzorqi, Ibrahim S.

2015-04-01

It has been demonstrated that composites are lightweight, fatigue resistant and easily melded, a seemingly attractive alternative to metals. However, there has been no widespread switch from metals to composites in the automotive sector. This is because there are a number of technical issues relating to the use of composite materials that still need to be resolved including accurate material characterization, manufacturing and joining process. The total of 36 specimens have been fabricated using the fibre-glass and resin (epoxy) with a two different geometries (circular and corrugated) each one will be filled with five types of filler (Rice Husk, Wood Chips, Aluminium Chips, Coconut Fibre, Palm Oil Fibre) all these type will be compared with empty Tubes for circular and corrugated in order to comprehend the crashworthiness parameters (initial failure load, average load, maximum crushing load, load ratio, energy absorption, specific energy absorption, volumetric energy absorption, crushing force efficiency and crush strain relation) which are considered very sufficient parameters in the design of automotive industry parts. All the tests have been done using the “INSTRON Universal machine” which is computerized in order to simply give a high precision to the collection of the results, along with the use of quasi-static load to test and observe the behaviour of the fabricated specimens.

Gravitational sedimentation of flocculated waste activated sludge.

PubMed

Chu, C P; Lee, D J; Tay, J H

2003-01-01

The sedimentation characteristics of flocculated wastewater sludge have not been satisfactorily explored using the non-destructive techniques, partially owing to the rather low solid content (ca. 1-2%) commonly noted in the biological sediments. This paper investigated, for the first time, the spatial-temporal gravitational settling characteristics of original and polyelectrolyte flocculated waste activated sludge using Computerized Axial Tomography Scanner. The waste activated sludge possessed a distinct settling characteristic from the kaolin slurries. The waste activated sludges settled more slowly and reached a lower solid fraction in the final sediment than the latter. Flocculation markedly enhanced the settleability of both sludges. Although the maximum achievable solid contents for the kaolin slurries were reduced, flocculation had little effects on the activated sludge. The purely plastic rheological model by Buscall and White (J Chem Soc Faraday Trans 1(83) (1987) 873) interpreted the consolidating sediment data, while the purely elastic model by Tiller and Leu (J. Chin. Inst. Chem. Eng. 11 (1980) 61) described the final equilibrated sediment. Flocculation produced lower yield stress during transient settling, thereby resulting in the more easily consolidated sludge than the original sample. Meanwhile, the flocculated activated sludge was stiffer in the final sediment than in the original sample. The data reported herein are valuable to the theories development for clarifier design and operation.

New formulation for interferometric synthetic aperture radar for terrain mapping

NASA Astrophysics Data System (ADS)

Jakowatz, Charles V., Jr.; Wahl, Daniel E.; Eichel, Paul H.; Thompson, Paul A.

1994-06-01

The subject of interferometric synthetic aperture radar (IFSAR) for high-accuracy terrain elevation mapping continues to gain importance in the arena of radar signal processing. Applications to problems in precision terrain-aided guidance and automatic target recognition, as well as a variety of civil applications, are being studied by a number of researchers. Not unlike many other areas of SAR processing, the subject of IFSAR can, at first glance, appear to be somewhat mysterious. In this paper we show how the mathematics of IFSAR for terrain elevation mapping using a pair of spotlight mode SAR collections can be derived in a very straightforward manner. Here, we employ an approach that relies entirely on Fourier transforms, and utilizes no reference to range equations or Doppler concepts. The result is a simplified explanation of the fundamentals of interferometry, including an easily-seen link between image domain phase difference and terrain elevation height. The derivation builds upon previous work by the authors in which a framework for spotlight mode SAR image formation based on an analogy to 3D computerized axial tomography (CAT) was developed. After outlining the major steps in the mathematics, we show how a computer simulator which utilizes 3D Fourier transforms can be constructed that demonstrates all of the major aspects of IFSAR from spotlight mode collections.

Gastrointestinal and nutritional problems in severe developmental disability.

PubMed

Somerville, Helen; Tzannes, Gloria; Wood, Jennifer; Shun, Albert; Hill, Christine; Arrowsmith, Fiona; Slater, Anne; O'Loughlin, Edward V

2008-09-01

The aim of this study was to describe the experience of 452 children and adults with a severe developmental disability who presented to a multidisciplinary clinic with swallowing, nutritional, and gastrointestinal problems. Data were obtained by chart review. Two hundred and ninety-four children (age range 7 mo-19 y, 173 males, 121 females) and 158 adults (age range 18-53 y; 90 males, 68 females) were assessed over 5 years. One hundred and eighty-two children and 86 adults had cerebral palsy. Approximately 90% were wheelchair dependent and totally dependent on caregivers for feeding; 60% had epilepsy. Pulmonary aspiration was identified by oesophageal videofluoroscopy in 41% of 174 children and 47% of 34 adults. Chronic oesophagitis and Helicobacter pylori were found in 57% of 182 children and 76% of 66 adults undergoing endoscopy. Chronic suppurative lung disease was identified by computerized axial tomography in 94% of 62 children and all six adults studied. Most patients improved with simple interventions. However, gastrostomy was recommended in 140 children and performed in 91, and in 10 adults but performed in seven, whereas fundoplication was recommended in 111 children and performed in 74, and in six adults but performed in two. In conclusion, chronic oesophagitis, pulmonary aspiration, and chronic lung disease were identified in many patients with a severe developmental disability.

Optical Analogies for Teaching Physics of X-rays and CAT Scans*

NASA Astrophysics Data System (ADS)

Kalita, Spartak; Zollman, D. A.

2006-12-01

Our Modern Miracle Medical Machines project is devoted to improving motivation and performance of pre-med students in their undergraduate Physics classes. Under its framework we designed some non-traditional hands-on lab activities involving optical analogies to teach the application of contemporary physics to medical imaging. On the basis of our previous research (primarily clinical interviews with the target student population) we created activities using semi-transparent Lego blocks as analogs for understanding the image reconstruction process in computerized axial tomography (CAT or CT). Teaching interviews have been conducted with pre-med and other health-related majors using these materials. Students had to determine the shape of an object constructed of Lego blocks and hidden within a closed box. This arrangement imitated an unknown entity within a part of the human body. Using LEDs (light-emitting diodes) and a photo detector the students attempted to learn the contents of the box. They also had access to another similar Lego arrangement which they were free to open. Interviewees successfully transferred knowledge from their science and math classes (as well as from other sources) while completing activities and expressed great interest in this endeavor. Improvements to the activities have been based on the students’ feedback. *Supported by the National Science Foundation under grant 04-2675

The Effectiveness of a 3D Computerized Tutorial to Enhance Learning of the Canine Larynx and Hyoid Apparatus.

PubMed

Nemanic, Sarah; Mills, Serena; Viehdorfer, Matt; Clark, Terri; Bailey, Mike

Teaching the anatomy of the canine larynx and hyoid apparatus is challenging because dissection disassembles and/or damages these structures, making it difficult to understand their three-dimensional (3D) anatomy and spatial interrelationships. This study assessed the effectiveness of an interactive, computerized 3D tutorial for teaching the anatomy of the canine larynx and hyoid apparatus using a randomized control design with students enrolled in the first-year professional program at Oregon State University College of Veterinary Medicine. All first-year students from 2 consecutive years were eligible. All students received the traditional methods of didactic teaching and dissection to learn the anatomy of the canine larynx and hyoid apparatus, after which they were divided into two statistically equal groups based on their cumulative anatomy test scores from the prior term. The tutorial group received an interactive, computerized tutorial developed by the investigators containing 3D images of the canine larynx and hyoid apparatus, while the control group received the same 3D images without the computerized tutorial. Both groups received the same post-learning assessment and survey. Sixty-three first-year students participated in the study, 28 in the tutorial group, and 35 in the control group. Post-learning assessment and survey scores were both significantly higher among students in the computerized tutorial group than those in the control group. This study demonstrates that a 3D computerized tutorial is more effective in teaching the anatomy of the canine hyoid apparatus and larynx than 3D images without a tutorial. Students likewise rated their learning experience higher when using the 3D computerized tutorial.

An Analysis of Minimum System Requirements to Support Computerized Adaptive Testing.

DTIC Science & Technology

1986-09-01

adaptive test ( CAT ); adaptive test ing A;4SRAC:’ (Continue on reverie of necessary and ident4f by block number) % This pape-r discusses the minimum system...requirements needed to develop a computerized adaptive test ( CAT ). It lists some of the benefits of adaptive testing, establishes a set of...discusses the minimum system requirements needed to develop a computerized adaptive test ( CAT ). It lists some of the benefits of adaptive testing

Build Your Own Inventory System. Annual Cost: $100.00 (Approximate). Fixed Assets, Materials and Supplies. The Practical Elements for a Computerized, Continuing Inventory System in Schools and Use in Determining a Measure for Instructional Cost.

ERIC Educational Resources Information Center

Payne, Arnold, Comp.

This publication presents performance flow charts and other accompanying forms that are elements of an economical computerized continuing inventory system. The system described here is intended to serve school systems as an adequate fixed asset system and to provide a computerized inventory model that offers support for costs of future educational…

Comparison of Centralized-Manual, Centralized-Computerized, and Decentralized-Computerized Order and Management Information Models for the Turkish Air Force Logistics System.

DTIC Science & Technology

1986-09-01

differentiation between the systems. This study will investigate an appropriate Order Processing and Management Information System (OP&MIS) to link base-level...methodology: 1. Reviewed the current order processing and information model of the TUAF Logistics System. (centralized-manual model) 2. Described the...RDS program’s order processing and information system. (centralized-computerized model) 3. Described the order irocessing and information system of

Computerized proof techniques for undergraduates

NASA Astrophysics Data System (ADS)

Smith, Christopher J.; Tefera, Akalu; Zeleke, Aklilu

2012-12-01

The use of computer algebra systems such as Maple and Mathematica is becoming increasingly important and widespread in mathematics learning, teaching and research. In this article, we present computerized proof techniques of Gosper, Wilf-Zeilberger and Zeilberger that can be used for enhancing the teaching and learning of topics in discrete mathematics. We demonstrate by examples how one can use these computerized proof techniques to raise students' interests in the discovery and proof of mathematical identities and enhance their problem-solving skills.

Language Research Center's Computerized Test System (LRC-CTS) - Video-formatted tasks for comparative primate research

NASA Technical Reports Server (NTRS)

Rumbaugh, Duane M.; Washburn, David A.; Savage-Rumbaugh, E. S.; Hopkins, William D.; Richardson, W. K.

1991-01-01

Automation of a computerized test system for comparative primate research is shown to improve the results of learning in standard paradigms. A mediational paradigm is used to determine the degree to which criterion in the learning-set testing reflects stimulus-response associative or mediational learning. Rhesus monkeys are shown to exhibit positive transfer as the criterion levels are shifted upwards, and the effectiveness of the computerized testing system is confirmed.

Clinical evaluation of the WOMAC 3.0 OA Index in numeric rating scale format using a computerized touch screen version.

PubMed

Theiler, R; Spielberger, J; Bischoff, H A; Bellamy, N; Huber, J; Kroesen, S

2002-06-01

The Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index is a previously described self-administered questionnaire covering three domains: pain, stiffness and function. It has been validated in patients with osteoarthritis (OA) of the hip or knee in a paper-based format. To validate the WOMAC 3.0 using a numerical rating scale in a computerized touch screen format allowing immediate evaluation of the questionnaire. In the computed version cartoons, written and audio instruments were included in order facilitate application. Fifty patients, demographically balanced, with radiographically proven primary hip or knee OA completed the classical paper and the new computerized WOMAC version. Subjects were randomized either to paper format or computerized format first to balance possible order effects. The intra-class correlation coefficients for pain, stiffness and function values were 0.915, 0.745 and 0.940, respectively. The Spearman correlation coefficients for pain, stiffness and function were 0.88, 0.77 and 0.87, respectively. These data indicate that the computerized WOMAC OA index 3.0 is comparable to the paper WOMAC in all three dimensions. The computerized version would allow physicians to get an immediate result and if present a direct comparison with a previous exam. Copyright 2002 OsteoArthritis Research Society International. Published by Elsevier Science Ltd. All rights reserved.

Multitasking capacities in persons diagnosed with schizophrenia: a preliminary examination of their neurocognitive underpinnings and ability to predict real world functioning.

PubMed

Laloyaux, Julien; Van der Linden, Martial; Levaux, Marie-Noëlle; Mourad, Haitham; Pirri, Anthony; Bertrand, Hervé; Domken, Marc-André; Adam, Stéphane; Larøi, Frank

2014-07-30

Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia and in particular during multitasking activities. However, at present, patients׳ multitasking capacities have not been adequately examined in the literature due to the absence of suitable assessment strategies. We thus recently developed a computerized real-life activity task designed to take into account the complex and multitasking nature of certain everyday life activities where participants are required to prepare a room for a meeting. Twenty-one individuals diagnosed with schizophrenia and 20 matched healthy controls completed the computerized task. Patients were also evaluated with a cognitive battery, measures of symptomatology and real world functioning. To examine the ecological validity, 14 other patients were recruited and were given the computerized version and a real version of the meeting preparation task. Results showed that performance on the computerized task was significantly correlated with executive functioning, pointing to the major implication of these cognitive processes in multitasking situations. Performance on the computerized task also significantly predicted up to 50% of real world functioning. Moreover, the computerized task demonstrated good ecological validity. These findings suggest the importance of evaluating multitasking capacities in patients diagnosed with schizophrenia in order to predict real world functioning. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Computerized photogrammetry used to calculate the brow position index.

PubMed

Naif-de-Andrade, Naif Thadeu; Hochman, Bernardo; Naif-de-Andrade, Camila Zirlis; Ferreira, Lydia Masako

2012-10-01

The orbital region is of vital importance to facial expression. Brow ptosis, besides having an impact on facial harmony, is a sign of aging. Various surgical techniques have been developed to increase the efficacy of brow-lift surgery. However, no consensus method exists for an objective measurement of the eyebrow position due to the curvature of the face. Therefore, this study aimed to establish a method for measuring the eyebrow position using computerized photogrammetry. For this study, 20 orbital regions of 10 volunteers were measured by direct anthropometry using a digital caliper and by indirect anthropometry (computerized photogrammetry) using standardized digital photographs. Lines, points, and distances were defined based on the position of the anthropometric landmarks endocanthion and exocanthion and then used to calculate the brow position index (BPI). Statistical analysis was performed using Student's t test with a significance level of 5 %. The BPI values obtained by computerized photogrammetric measurements did not differ significantly from those obtained by direct anthropometric measurements (p > 0.05). The mean BPI was 84.89 ± 10.30 for the computerized photogrammetric measurements and 85.27 ± 10.67 for the direct anthropometric measurements. The BPI defined in this study and obtained by computerized photogrammetry is a reproducible and efficient method for measuring the eyebrow position. This journal requires that authors assign a level of evidence to each article.

Surface mapping of spike potential fields: experienced EEGers vs. computerized analysis.

PubMed

Koszer, S; Moshé, S L; Legatt, A D; Shinnar, S; Goldensohn, E S

1996-03-01

An EEG epileptiform spike focus recorded with scalp electrodes is clinically localized by visual estimation of the point of maximal voltage and the distribution of its surrounding voltages. We compared such estimated voltage maps, drawn by experienced electroencephalographers (EEGers), with a computerized spline interpolation technique employed in the commercially available software package FOCUS. Twenty-two spikes were recorded from 15 patients during long-term continuous EEG monitoring. Maps of voltage distribution from the 28 electrodes surrounding the points of maximum change in slope (the spike maximum) were constructed by the EEGer. The same points of maximum spike and voltage distributions at the 29 electrodes were mapped by computerized spline interpolation and a comparison between the two methods was made. The findings indicate that the computerized spline mapping techniques employed in FOCUS construct voltage maps with similar maxima and distributions as the maps created by experienced EEGers. The dynamics of spike activity, including correlations, are better visualized using the computerized technique than by manual interpretation alone. Its use as a technique for spike localization is accurate and adds information of potential clinical value.

Early-term and mid-term histologic events during single-level posterolateral intertransverse process fusion with rhBMP-2/collagen carrier and a ceramic bulking agent in a nonhuman primate model: implications for bone graft preparation.

PubMed

Khan, Safdar N; Toth, Jeffrey M; Gupta, Kavita; Glassman, Steven D; Gupta, Munish C

2014-06-01

We used a nonhuman primate lumbar intertransverse process arthrodesis model to evaluate biological cascade of bone formation using different carrier preparation methods with a single dose of recombinant human bone morphogenetic protein-2 (rhBMP-2) at early time points. To examine early-term/mid-term descriptive histologic and computerized tomographic events in single-level uninstrumented posterolateral nonhuman primate spinal fusions using rhBMP-2/absorbable collagen sponge (ACS) combined with ceramic bulking agents in 3 different configurations. rhBMP-2 on an ACS carrier alone leads to consistent posterolateral lumbar spine fusions in lower-order animals; however, these results have been difficult to replicate in nonhuman primates. Twelve skeletally mature, rhesus macaque monkeys underwent single-level posterolateral arthrodesis at L4-L5. A hydroxyapatite/β-tricalcium phosphate ceramic bulking agent in 3 formulations was used in the treatment groups (n=3). When used, rhBMP-2/ACS at 1.5 mg/cm (3.0 mg rhBMP-2) was combined with 2.5 cm of ceramic bulking agent per side. Animals were euthanized at 4 and 12 weeks postoperative. Computerized tomography scans were performed immediately postoperatively and every 4 weeks until they were euthanized. Sagittal histologic sections were evaluated for bone histogenesis and location, cellular infiltration of the graft/substitute, and bone remodeling activity. Significant histologic differences in the developing fusion appeared between the 3 rhBMP-2/ACS treatment groups at 4 and 12 weeks. At 4 weeks, bone formation appeared to originate at the transverse process and the intertransverse membrane. Cellular infiltration was greatest in granular ceramic groups compared with matrix ceramic group. Minimal to no residual ACS was identified at the early time point. At 12 weeks, marked ceramic remodeling was observed with continued bone formation noted in all carrier groups. At the early time period, histology showed that bone formation appeared to originate at the transverse processes and the intertransverse membrane, indicating that the dorsal muscle bed may not be the only location for bone formation. Histology also showed that the collagen carrier for rhBMP-2 is mostly resorbed by 4 weeks. Our results and previous literature indicate that ceramic bulking agents are needed to provide resistance to compression caused by paraspinal muscles on the fusion bed in the posterolateral environment. Histology showed that ceramic bulking agents may offer long-term scaffolding and a structure to supporting bone formation of the developing fusion mass.

Supporting Patient Care in the Emergency Department with a Computerized Whiteboard System

PubMed Central

Aronsky, Dominik; Jones, Ian; Lanaghan, Kevin; Slovis, Corey M.

2008-01-01

Efficient information management and communication within the emergency department (ED) is essential to providing timely and high-quality patient care. The ED whiteboard (census board) usually serves as an ED’s central access point for operational and patient-related information. This article describes the design, functionality, and experiences with a computerized ED whiteboard, which has the ability to display relevant operational and patient-related information in real time. Embedded functionality, additional whiteboard views, and the integration with ED and institutional information system components, such as the computerized patient record or the provider order entry system, provide rapid access to more detailed information. As an information center, the computerized whiteboard supports our ED environment not only for providing patient care, but also for operational, educational, and research activities. PMID:18096913

Full-wave Moment Tensor and Tomographic Inversions Based on 3D Strain Green Tensor

DTIC Science & Technology

2010-01-31

propagation in three-dimensional (3D) earth, linearizes the inverse problem by iteratively updating the earth model , and provides an accurate way to...self-consistent FD-SGT databases constructed from finite-difference simulations of wave propagation in full-wave tomographic models can be used to...determine the moment tensors within minutes after a seismic event, making it possible for real time monitoring using 3D models . 15. SUBJECT TERMS

Medical ultrasonic tomographic system

NASA Technical Reports Server (NTRS)

Heyser, R. C.; Lecroissette, D. H.; Nathan, R.; Wilson, R. L.

1977-01-01

An electro-mechanical scanning assembly was designed and fabricated for the purpose of generating an ultrasound tomogram. A low cost modality was demonstrated in which analog instrumentation methods formed a tomogram on photographic film. Successful tomogram reconstructions were obtained on in vitro test objects by using the attenuation of the fist path ultrasound signal as it passed through the test object. The nearly half century tomographic methods of X-ray analysis were verified as being useful for ultrasound imaging.

Integration of TomoPy and the ASTRA toolbox for advanced processing and reconstruction of tomographic synchrotron data

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

Pelt, Daniël M.; Gürsoy, Dogˇa; Palenstijn, Willem Jan

2016-04-28

The processing of tomographic synchrotron data requires advanced and efficient software to be able to produce accurate results in reasonable time. In this paper, the integration of two software toolboxes, TomoPy and the ASTRA toolbox, which, together, provide a powerful framework for processing tomographic data, is presented. The integration combines the advantages of both toolboxes, such as the user-friendliness and CPU-efficient methods of TomoPy and the flexibility and optimized GPU-based reconstruction methods of the ASTRA toolbox. It is shown that both toolboxes can be easily installed and used together, requiring only minor changes to existing TomoPy scripts. Furthermore, it ismore » shown that the efficient GPU-based reconstruction methods of the ASTRA toolbox can significantly decrease the time needed to reconstruct large datasets, and that advanced reconstruction methods can improve reconstruction quality compared with TomoPy's standard reconstruction method.« less

Tomographic capabilities of the new GEM based SXR diagnostic of WEST

NASA Astrophysics Data System (ADS)

Jardin, A.; Mazon, D.; O'Mullane, M.; Mlynar, J.; Loffelmann, V.; Imrisek, M.; Chernyshova, M.; Czarski, T.; Kasprowicz, G.; Wojenski, A.; Bourdelle, C.; Malard, P.

2016-07-01

The tokamak WEST (Tungsten Environment in Steady-State Tokamak) will start operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of heavy impurities like tungsten (W) in the Soft X-ray (SXR) range [0.1 keV; 20 keV] is a critical issue for the plasma core performances. Thus reliable tools are required to monitor the local impurity density and avoid W accumulation. The WEST SXR diagnostic will be equipped with two new GEM (Gas Electron Multiplier) based poloidal cameras allowing to perform 2D tomographic reconstructions in tunable energy bands. In this paper tomographic capabilities of the Minimum Fisher Information (MFI) algorithm developed for Tore Supra and upgraded for WEST are investigated, in particular through a set of emissivity phantoms and the standard WEST scenario including reconstruction errors, influence of noise as well as computational time.

Image Reconstruction is a New Frontier of Machine Learning.

PubMed

Wang, Ge; Ye, Jong Chu; Mueller, Klaus; Fessler, Jeffrey A

2018-06-01

Over past several years, machine learning, or more generally artificial intelligence, has generated overwhelming research interest and attracted unprecedented public attention. As tomographic imaging researchers, we share the excitement from our imaging perspective [item 1) in the Appendix], and organized this special issue dedicated to the theme of "Machine learning for image reconstruction." This special issue is a sister issue of the special issue published in May 2016 of this journal with the theme "Deep learning in medical imaging" [item 2) in the Appendix]. While the previous special issue targeted medical image processing/analysis, this special issue focuses on data-driven tomographic reconstruction. These two special issues are highly complementary, since image reconstruction and image analysis are two of the main pillars for medical imaging. Together we cover the whole workflow of medical imaging: from tomographic raw data/features to reconstructed images and then extracted diagnostic features/readings.