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Sample records for intravenous digital subtraction

  1. Intravenous digital subtraction angiography in the investigation of intracranial disease

    SciTech Connect

    DeFilipp, G.J.; Pinto, R.S.; Lin, J.P.; Kricheff, I.I.

    1983-07-01

    Eighty-six patients who presented with a variety of intracranial lesions were examined with intravenous digital subtraction angiogrphy (IV-DSA). A grading system was used to evaluate the ability IV-DSA to answer specific diagnostic questions regarding intracranial tumors, vasospasm following subarachnoid hemorrhage, lesions of the sella, dural sinus occlusion, and post-therapeutic embolization. Eighty-four percent of the examinations provided clinically useful information. In 15% of the cases limited but useful information was obtained; only 1% of the examinations provided no useful information. We conclude that IV-DSA can routinely provide useful information in the evaluation of the variety of intracranial lesions described above.

  2. Intravenous Digital Subtraction Angiography (DSA) of Hemodialysis Access Fistulae

    PubMed Central

    Allen, Gregory J.; Burnett, Keith R.; Vaziri, Nosratola D.; Friedenberg, Richard M.

    1986-01-01

    Hemodialysis access fistulae or grafts are subject to a variety of complications, including thrombosis, stenoses, and aneurysm or pseudoaneurysm formation. The usual radiologic methods to evaluate these problems consist of retrograde venous angiography or standard femoral or brachial arteriography. Both are invasive, and may traumatize the artery or graft. Six patients with internal blood access were studied using digital subtraction angiography; five using a central venous injection and one with direct graft injection. Preliminary results indicate that intravenous digital subtraction angiography (IV-DSA) can depict the anatomy of access fistula with adequate spatial resolution. Pathologic entities (stenoses, aneurysms) can be demonstrated, as well as other findings of uncertain clinical significance (kinks and webs). In addition, hemodynamic data can be inferred from the near-physiologic sequence of vessel opacification. Methods are in development that will allow determination of absolute blood flow in pertinent vessels via IV-DSA. There were no complications in this small series, and all examinations were performed on outpatients utilizing standard technique. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:3537322

  3. Videodensitometric ejection fraction from intravenous digital subtraction right ventriculograms: correlation with first pass radionuclide ejection fraction

    SciTech Connect

    Detrano, R.; MacIntyre, W.; Salcedo, E.E.; O'Donnell, J.; Underwood, D.A.; Simpfendorfer, C.; Go, R.T.; Butters, K.; Withrow, S.

    1985-06-01

    Thirty-one consecutive patients undergoing intravenous blurred mask digital subtraction right ventriculography were submitted to first pass radionuclide angiography. Second order mask resubtraction of end-diastolic and end-systolic right ventricular digital image frames was executed using preinjection end-diastolic and end-systolic frames to rid the digital subtraction images of mis-registration artifact. End-diastolic and end-systolic perimeters were drawn manually by two independent observers with a light pen. Ejection fractions calculated from the integrated videodensitometric counts within these perimeters correlated well with those derived from the first pass radionuclide right ventriculogram (r = 0.84) and the interobserver correlation was acceptable (r = 0.91). Interobserver differences occurred more frequently in patients with atrial fibrillation and in those whose tricuspid valve planes were difficult to discern on the digital subtraction right ventriculograms. These results suggest that videodensitometric analysis of digital subtraction right ventriculograms is an accurate method of determining right ventricular ejection fraction and may find wide clinical applicability.

  4. Quantitative Assessment of Regional Wall Motion Abnormalities Using Dual-Energy Digital Subtraction Intravenous Ventriculography

    NASA Astrophysics Data System (ADS)

    McCollough, Cynthia H.

    Healthy portions of the left ventricle (LV) can often compensate for regional dysfunction, thereby masking regional disease when global indices of LV function are employed. Thus, quantitation of regional function provides a more useful method of assessing LV function, especially in diseases that have regional effects such as coronary artery disease. This dissertation studied the ability of a phase -matched dual-energy digital subtraction angiography (DE -DSA) technique to quantitate changes in regional LV systolic volume. The potential benefits and a theoretical description of the DE imaging technique are detailed. A correlated noise reduction algorithm is also presented which raises the signal-to-noise ratio of DE images by a factor of 2 -4. Ten open-chest dogs were instrumented with transmural ultrasonic crystals to assess regional LV function in terms of systolic normalized-wall-thickening rate (NWTR) and percent-systolic-thickening (PST). A pneumatic occluder was placed on the left-anterior-descending (LAD) coronary artery to temporarily reduce myocardial blood flow, thereby changing regional LV function in the LAD bed. DE-DSA intravenous left ventriculograms were obtained at control and four levels of graded myocardial ischemia, as determined by reductions in PST. Phase-matched images displaying changes in systolic contractile function were created by subtracting an end-systolic (ES) control image from ES images acquired at each level of myocardial ischemia. The resulting wall-motion difference signal (WMD), which represents a change in regional systolic volume between the control and ischemic states, was quantitated by videodensitometry and compared with changes in NWTR and PST. Regression analysis of 56 data points from 10 animals shows a linear relationship between WMD and both NWTR and PST: WMD = -2.46 NWTR + 13.9, r = 0.64, p < 0.001; WMD = -2.11 PST + 18.4, r = 0.54, p < 0.001. Thus, changes in regional ES LV volume between rest and ischemic states, as

  5. Digital subtraction angiography of the heart and lungs

    SciTech Connect

    Moodie, D.S.; Yiannikas, J.

    1986-01-01

    This book contains 12 chapters. Some of the chapter titles are: Physical Principles of Cardiac Digital Subtraction Angiography, The Use of Intravenous Digital Subtraction Angiography in Evaluating Patients with Complex Congenital Heart Disease, Exercise Intravenous Digital Subtraction Angiograpny, Cardiomyopathic and Cardiac Neoplastic Disease, Digital Subtraction Angiography in the Catheterization Laboratory, and Cardiac Digital Subtraction Angiography - Future Directions.

  6. Pediatric digital subtraction angiography

    SciTech Connect

    Amundson, G.M.; Wesenberg, R.L.; Mueller, D.L.; Reid, R.H.

    1984-12-01

    Experience with intravenous digital subtraction angiography (DSA) in infants and children is limited, although its relative rate of performance, low complication rate, and diagnostic accuracy indicate great potential. The authors performed 87 DSA examinations (74 patients) and obtained sufficient detail to facilitate diagnosis in most cases. The major problems of patient movement and overlapping vessels can be minimized by judicious use of sedation and strict attention to technique. Exposure of patients to radiation has not been a limiting factor since our system uses low exposure factors. Our results demonstrate that DSA has wide applicability to many organ systems and is especially useful in intracranial disease and for preoperative evaluation of neoplasms.

  7. Digital subtraction laryngography

    SciTech Connect

    Brown, B.W.; Enzmann, D.R.; Hopp, M.L.; Castellino, R.A.

    1983-06-01

    Digital subtraction laryngography was used to evaluate laryngeal function in 8 patients: 4 with normal larynxes and 4 with laryngeal disease. Subtracted digital images provided a dynamic display of the extent and symmetry of vocal cord excursions and pyriform sinus inflation, and the vocal cord resting position was also clearly depicted. The technical details of digital subtraction laryngography and its application are described.

  8. Diagnosis of Cardiovascular Disease by Digital Subtraction Angiography

    NASA Astrophysics Data System (ADS)

    Mistretta, Charles A.; Crummy, Andrew B.

    1981-11-01

    Recent advances in real-time digital video processing have led to a practical method for intravenous arteriography. The digital subtraction technique, which detects small differences in the concentration of the iodinated contrast material injected, is relatively safe and does not usually require hospitalization of the patient. The technique can thus be used for serial evaluation of various clinical problems and for studying the natural history of certain disease processes, as well as for following therapeutic endeavors.

  9. Digital subtraction angiography of the portal venous system

    SciTech Connect

    Foley, W.D.; Stewart E.T.; Milbrath, J.R.; SanDretto, M.; Milde, M.

    1983-03-01

    Venous-phase arteriography after celiac or superior mesenteric artery injection is the most common technique used to demonstrate portal venous anatomy, flow direction, and portal systemic shunts. Large-volume contrast material injections and intraarterial vasodilators or balloon occlusion technique are required for optimal examinations using film-screen recording. A technique for performing venous-phase arteriography with digital subtraction imaging after celiac and superior mesenteric artery injection is described. The major advantage of intraarterial digital subtraction technique in comparison to film-screen recording is sensitivity to intravascular iodine with a consequent reduction in contrast material load and examination time. Technical success is limited only by motion artifact and should approximate the 80%-90% figure achieved for intravenous digital subtraction angiography of the aortorenal vessels.

  10. Evaluation of vascular rings with digital subtraction angiography.

    PubMed

    Tonkin, I L; Gold, R E; Moser, D; Laster, R E

    1984-06-01

    Seven patients with vascular rings were evaluated over a 2-year period with intravenous digital subtraction angiography (DSA), which was compared with screen-film aortography or cineangiography. The seven patients were also evaluated with barium esophagography. Six of the seven DSA images were totally diagnostic and one study was only partly diagnostic. Six of the seven vascular anomalies were confirmed surgically. DSA is suggested as an alternative to arteriography in evaluating patients with suspected vascular rings. PMID:6372419

  11. The utility of digital subtraction arteriography in peripheral vascular disease.

    PubMed

    Kubal, W S; Crummy, A B; Turnipseed, W D

    1983-01-01

    Digital subtraction angiography (DSA), whether used in conjunction with intravenous or intraarterial injection techniques, has an established role in evaluation of peripheral vascular disease. Use of DSA can reduce the time, cost, and patient discomfort of the standard arteriographic study. While it is limited by field size and patient cooperation in some instances, the utility of noninvasive imaging using intravenous DSA and the added anatomic detail of intraarterial DSA for roadmapping and delineation of small distal vessels provide the basis for future integration of standard arteriographic and DSA methods in assessment of peripheral vascular disease. PMID:6228296

  12. Children's Use of Subtraction by Addition on Large Single-Digit Subtractions

    ERIC Educational Resources Information Center

    Peters, Greet; De Smedt, Bert; Torbeyns, Joke; Ghesquiere, Pol; Verschaffel, Lieven

    2012-01-01

    Subtractions of the type M - S = ? can be solved by various strategies, including subtraction by addition. In this study, we investigated children's use of subtraction by addition by means of reaction time analyses. We presented 106 third to sixth graders with 32 large non-tie single-digit problems in both subtraction (12 - 9 = .) and addition…

  13. Digital subtraction angiography in extremity trauma

    SciTech Connect

    Goodman, P.C.; Jeffrey, R.B. Jr.; Brant-Zawadzki, M.

    1984-10-01

    Digital subtraction angiography (DSA) may have considerable impact on the work-up of patients who have suffered trauma. The angiographic evaluation of vascular injuries can be accomplished rapidly and with minimal catheter use and manipulation, which is particularly important for those critically ill patients who have significant immobility because of multiple fractures. The authors retrospectively reviewed the digital subtraction angiograms in 50 consecutive cases of extremity trauma. The quality of the images in 44 of these permitted a confident diagnosis, the accuracy of which was confirmed by surgical or clinical follow-up. DSA reduces the time required to perform the procedure, the amount of contrast material injected, patient discomfort, and film cost. Its major disadvantage is the limited field size of the image intensifier.

  14. Tomosynthesis applied to digital subtraction angiography

    SciTech Connect

    Kruger, R.A.; Sedaghati, M.; Roy, D.G.; Liu, P.; Nelson, J.A.; Kubal, W.; Del Rio, P.

    1984-09-01

    This extension of the author's previous work on tomographic digital subtraction angiography (DSA) describes the theory of tomosynthetic DSA image reconstruction techniques. In addition to developing the resolution limits resulting from x-ray exposure length and image intensifier field curvature, the authors describe one method of image formation and show tomosynthetic DSA images of animal and human anatomy. Methods for improving the present technique are discussed.

  15. Digital subtraction angiography: overview of technical principles.

    PubMed

    Harrington, D P; Boxt, L M; Murray, P D

    1982-10-01

    The rapid development of equipment for digital subtraction angiography (DSA) has created a new diagnostic imaging method, the limits of which have not been scientifically determined. Yet through aggressive marketing, the technique is already beginning to permeate radiologic practice. The radiologist requires technical understanding of the instrumentation for informed judgment on clinical applications. DSA depends on the mating of high-resolution image-intensifier and television technology with computerized information manipulation and storage. In this overview, the individual components of the system are analyzed, from the generator to the image intensifier to the television system to the associated computer. By examining the role of each component, the current limitations and the areas of possible future development of DSA can be understood. This provides a basis for dealing with current technology and for evaluating the rapid technological changes that will occur over the next few years. PMID:6751053

  16. [Digital subtraction radiography for the detection of periodontal bone changes].

    PubMed

    Mera, T

    1989-03-01

    This study was performed to evaluate the efficacy of digital subtraction radiography in detecting alveolar bone changes. In order to test the sensitivity of quantitative evaluation by subtraction radiography, a copper equivalent thickness obtained from digitized radiographs was compared with the actual mineral content of bone phantoms with 15 different minerals and 25 bone specimens. Results demonstrated that the copper equivalent thickness correlated well with the actual mineral content (bone phantoms: gamma s = 1.0, bone specimens: gamma s = 0.985). In order to test the ability of digitized subtraction radiography in assessing alveolar bone changes in vivo, subtraction images were compared with histological features. The experimental angular bony defects were treated with conservative periodontal therapy in 3 monkeys. The standardized radiographs were taken longitudinally after therapy, and subtraction images were made from the sequentially obtained radiographs. In addition, for fluorescent histomorphometrical evaluations of new bone formations, the animals were dosed with oxytetracycline, calsein solution and arizarin complex solution. Radiographic and histological evaluations were scheduled to provide healing periods of 2, 3, 4, 5, 6 and 9 weeks after periodontal therapy. Subtraction radiography offered an objective method to follow histological changes of alveolar bone, and the copper equivalent thickness obtained from subtraction radiographs correlated with the histometric bone volume (gamma s = 0.9023, p less than 0.01). The results of these studies indicated that subtraction radiography was useful in monitoring alveolar bone changes associated with periodontal disease and treatment and that the quanitative measurement of periodontal bone changes by subtraction radiography was feasible. PMID:2517790

  17. EKG-gated digital subtraction angiography in the detection of pulmonary emboli. [Dogs

    SciTech Connect

    Hirji, M.; Gamsu, G.; Webb, W.R.; Brito, A.C.; Kuriyama, K.; Stern, R.G.; Cox, L.

    1984-07-01

    Detection of pulmonary emboli was investigated using electrocardiographically gated (EKG-gated) intravenous digital subtraction angiography (DSA) in 6 anesthetized and paralyzed dogs. Six autologous blood clots were introducted into the internal jugular vein of each dog and both conventional pulmonary angiography and EKG- gated DSA performed in frontal and oblique projections. The authors conclude that DSA can demonstrate individual emboli with good sensitivity and excellent precision. If several emboli are present, KEG-gated DSA should prove highly accurate; however, care must be taken because overinterpretation is more likely with DSA than with conventional pulmonary angiography.

  18. Digital subtraction angiography in pediatric cerebrovascular occlusive disease

    SciTech Connect

    Faerber, E.N.; Griska, L.A.B.; Swartz, J.D.; Capitanio, M.A.; Popky, G.L.

    1984-08-01

    While conventional angiography has been used to demonstrate cerebrovascular occlusive disease in the past, digital subtraction angiography (DSA) is capable of showing progressive vascular involvement with ease, simplicity, and extremely low morbidity, making it particularly well suited for children and outpatients either alone or coordinated with computed tomography. The authors discuss the usefulness and advantages of DSA as demonstrated in 7 infants and children with hemiplegia, 4 of whom had sickle-cell disease.

  19. Digital subtraction angiography of a persistent trigeminal artery variant.

    PubMed

    Temizöz, Osman; Genchellac, Hakan; Unlü, Ercüment; Cağli, Bekir; Ozdemir, Hüseyin; Demir, M Kemal

    2010-09-01

    Persistent trigeminal artery variants are described as cerebellar arteries that directly originate from the precavernous segment of the internal carotid artery. This has been observed in 0.18% of cerebral catheter angiograms. On the other hand, a persistent trigeminal artery variant feeding both the anterior inferior cerebellar artery and the posterior inferior cerebellar artery territory is very rare. We present this uncommon anomalous artery along with digital subtraction angiography findings and discuss its clinical significance in light of the literature. PMID:19821254

  20. Contrast matching techniques for digital subtraction radiography: an objective evaluation.

    PubMed Central

    Likar, B.; Bernard, R.; Pernus, F.

    1996-01-01

    Digital subtraction radiography (DSR) enables the detection of subtle early detrimental effects of periodontal disease as well as the evaluation of the effects of therapy. However, the differences between two radiographs due to alignment and contrast errors must be kept at minimum. In the present in vitro study we test the efficacy of three basic contrast correction methods in the reduction of contrast mismatches which can adversely affect a subtracted image. The ODTF (Optical Density Thickness Function) method, which is based on a function relating grey level values of the aluminium wedge image and the corresponding thickness of the wedge, induced less contrast correction error than the CDF (Cumulative Density Function) and the LSQA (Least Square Quadratic Approximation) methods. Moreover, CDF, ODTF, and LSQA functions obtained from the reference structure density distribution may be applied for objective contrast enhancements and for standardisation of image quality, while the ODTF function allows also bone change volume estimations. PMID:8947675

  1. IMPROVED BACKGROUND SUBTRACTION FOR THE SLOAN DIGITAL SKY SURVEY IMAGES

    SciTech Connect

    Blanton, Michael R.; Kazin, Eyal; Muna, Demitri; Weaver, Benjamin A.; Price-Whelan, Adrian

    2011-07-15

    We describe a procedure for background subtracting Sloan Digital Sky Survey (SDSS) imaging that improves the resulting detection and photometry of large galaxies on the sky. Within each SDSS drift scan run, we mask out detected sources and then fit a smooth function to the variation of the sky background. This procedure has been applied to all SDSS-III Data Release 8 images, and the results are available as part of that data set. We have tested the effect of our background subtraction on the photometry of large galaxies by inserting fake galaxies into the raw pixels, reanalyzing the data, and measuring them after background subtraction. Our technique results in no size-dependent bias in galaxy fluxes up to half-light radii r{sub 50} {approx} 100 arcsec; in contrast, for galaxies of that size the standard SDSS photometric catalog underestimates fluxes by about 1.5 mag. Our results represent a substantial improvement over the standard SDSS catalog results and should form the basis of any analysis of nearby galaxies using the SDSS imaging data.

  2. Tomographic digital subtraction angiography for lung perfusion estimation in rodents

    SciTech Connect

    Badea, Cristian T.; Hedlund, Laurence W.; De Lin, Ming; Boslego Mackel, Julie S.; Samei, Ehsan; Allan Johnson, G.

    2007-05-15

    In vivo measurements of perfusion present a challenge to existing small animal imaging techniques such as magnetic resonance microscopy, micro computed tomography, micro positron emission tomography, and microSPECT, due to combined requirements for high spatial and temporal resolution. We demonstrate the use of tomographic digital subtraction angiography (TDSA) for estimation of perfusion in small animals. TDSA augments conventional digital subtraction angiography (DSA) by providing three-dimensional spatial information using tomosynthesis algorithms. TDSA is based on the novel paradigm that the same time density curves can be reproduced in a number of consecutive injections of {mu}L volumes of contrast at a series of different angles of rotation. The capabilities of TDSA are established in studies on lung perfusion in rats. Using an imaging system developed in-house, we acquired data for four-dimensional (4D) imaging with temporal resolution of 140 ms, in-plane spatial resolution of 100 {mu}m, and slice thickness on the order of millimeters. Based on a structured experimental approach, we optimized TDSA imaging providing a good trade-off between slice thickness, the number of injections, contrast to noise, and immunity to artifacts. Both DSA and TDSA images were used to create parametric maps of perfusion. TDSA imaging has potential application in a number of areas where functional perfusion measurements in 4D can provide valuable insight into animal models of disease and response to therapeutics.

  3. Using a digital signal processor as a data stream controller for digital subtraction angiography

    SciTech Connect

    Meng, J.D.; Katz, J.E.

    1991-10-01

    High speed, flexibility, and good arithmetic abilities make digital signal processors (DSP) a good choice as input/output controllers for real time applications. The DSP can be made to pre-process data in real time to reduce data volume, to open early windows on what is being acquired and to implement local servo loops. We present an example of a DSP as an input/output controller for a digital subtraction angiographic imaging system. The DSP pre-processes the raw data, reducing data volume by a factor of two, and is potentially capable of producing real-time subtracted images for immediate display.

  4. Using a digital signal processor as a data stream controller in digital subtraction angiography

    SciTech Connect

    Meng, J.D.; Katz, J.E. )

    1993-04-01

    High speed, flexibility, and good arithmetic abilities make digital signal processors (DSP) a good choice as input/output controllers for real time applications. The DSP can be made to pre-process data in real time to reduce data volume, to open early windows on what is being acquired and to implement input/output controller for a digital subtraction angiographic imaging system. The DSP pre-processes the raw data, reducing data volume by a factor of two, and is potentially capable of producing real-time subtracted images for immediate display.

  5. The Principle of Digital Subtraction Angiography and Radiological Protection

    PubMed Central

    Okamoto, K.; Ito, J.; Sakai, K.; Yoshimura, S.

    2000-01-01

    Summary Recent improvements in x-ray technology have greatly contributed to the advancement of diagnostic imaging. Fluoroscopically guided neurointerventional procedures with digital subtraction angiography (DSΛ) are being performed with increasing frequency as the treatment of choice for a variety of neurovascular diseases. Radiation-induced skin injuries can occur after extended fluoroscopic exposure times, and the injuries have recently been reported. In this article, measured radiation doses at the surface of Rando Phantom with Skin Dose Monitor, and estimated and measured entrance skin doses in patients underwent neurointerventional procedures are reported as well as means of reducing radiation doses absorbed by patients and personnel to avoid occurrence of radiation-induced injuries. PMID:20667218

  6. Multinuclide digital subtraction imaging in symptomatic prostnetic joints

    SciTech Connect

    Chafetz, N.; Hattner, R.S.; Ruarke, W.C.; Helms, C.A.; Genant, H.K.; Murray, W.R.

    1985-06-01

    One hundred eleven patients with symptomatic prosthetic joints (86 hips, 23 knees, and two shoulders) were evaluated for prosthetic loosening and infection by combined technetium-99m-MDP/gallium-67 digital subtraction imaging. Clinical correlation was based on the assessment of loosening and bacterial cultures obtained at the time of surgery in 54 patients, joint aspiration cultures obtained in 37 patients, and long-term clinical follow-up for greater than 1.5 years in an additional 15 patients. Results revealed an 80-90% predictive value of a positive test for loosening, and a 95% predictive value of a negative test for infection. However, because of the low sensitivities and specificities observed, this approach to the evaluation of symptomatic prosthetic joints does not seem cost effective.

  7. Efficiency and Flexibility of Indirect Addition in the Domain of Multi-Digit Subtraction

    ERIC Educational Resources Information Center

    Torbeyns, Joke; Ghesquiere, Pol; Verschaffel, Lieven

    2009-01-01

    This article discusses the characteristics of the indirect addition strategy (IA) in the domain of multi-digit subtraction. In two studies, adults' use of IA on three-digit subtractions with a small, medium, or large difference between the integers was analysed using the choice/no-choice method. Results from both studies indicate that adults…

  8. Mental Computation or Standard Algorithm? Children's Strategy Choices on Multi-Digit Subtractions

    ERIC Educational Resources Information Center

    Torbeyns, Joke; Verschaffel, Lieven

    2016-01-01

    This study analyzed children's use of mental computation strategies and the standard algorithm on multi-digit subtractions. Fifty-eight Flemish 4th graders of varying mathematical achievement level were individually offered subtractions that either stimulated the use of mental computation strategies or the standard algorithm in one choice and two…

  9. Digital subtraction angiography in the evaluation of left ventricular function and wall motion in man.

    PubMed

    O'Connor, M K; Quigley, P J; Gearty, G F

    1984-08-01

    The purpose of this study was to examine the usefulness of digital subtraction angiography in the evaluation of left ventricular function (LVF). LVF was examined in 24 patients by three methods, (a) conventional ventriculography using an intraventricular injection (CLV) of 40 ml of contrast medium, (b) small volume (10-15 ml) left ventriculogram (SVLV) and (c) intravenous injection of 30 ml contrast medium (IVLV). Images were recorded via a conventional image intensifier--TV chain on to video tape and later analysed using a nuclear medicine computer with a digital interface. There was excellent correlation of ejection fraction and wall motion abnormalities between CLV and SVLV methods (r = 0.92 and r = 0.71, respectively) and good correlation between CLV and IVLV methods (r = 0.88 and r = 0.67, respectively). However, only minimal contrast induced premature ventricular contractions were observed in either the SVLV or IVLV methods compared with approximately 60% in the CLV method. Exclusion of studies containing ectopic cardiac cycles considerably improved the correlation between CLV and SVLV (r = 0.97) and between CLV and IVLV methods (r = 0.95). In conclusion, our results indicate that conventional left ventriculography may be replaced by either intravenous or small volume intraventricular methods with little loss of wall motion definition or error in ejection fraction estimation. The less invasive nature of the SVLV and IVLV methods should increase the usefulness of left ventriculography and extend its application to the assessment of left ventricular reserve under stress and during drug intervention. PMID:6207025

  10. Titanium plate artefact mimicking popliteal artery dissection on digital subtraction CT angiography

    PubMed Central

    Woodacre, Timothy; Wienand-Barnett, Sophie

    2013-01-01

    Titanium plates used for the internal fixation of long bone fractures cause significant artefact on CT scans but have not been reported to affect digital subtraction CT angiography. We present a patient with clinical suspicion of popliteal artery injury following a high tibial osteotomy. The osteotomy was stabilised with a titanium locking plate. During the digital subtraction process used to produce reconstruction CT angiography, removal of artefact caused by the titanium plate produced CT images mimicking the appearance of a popliteal artery dissection. The imaging inaccuracy was realised prior to the patient undergoing further intervention. We highlight the potential error caused by titanium plates on digital subtraction CT angiography and recommend careful analysis of such images prior to further treatment. PMID:23563677

  11. [Development of a digital chest phantom for studies on energy subtraction techniques].

    PubMed

    Hayashi, Norio; Taniguchi, Anna; Noto, Kimiya; Shimosegawa, Masayuki; Ogura, Toshihiro; Doi, Kunio

    2014-03-01

    Digital chest phantoms continue to play a significant role in optimizing imaging parameters for chest X-ray examinations. The purpose of this study was to develop a digital chest phantom for studies on energy subtraction techniques under ideal conditions without image noise. Computed tomography (CT) images from the LIDC (Lung Image Database Consortium) were employed to develop a digital chest phantom. The method consisted of the following four steps: 1) segmentation of the lung and bone regions on CT images; 2) creation of simulated nodules; 3) transformation to attenuation coefficient maps from the segmented images; and 4) projection from attenuation coefficient maps. To evaluate the usefulness of digital chest phantoms, we determined the contrast of the simulated nodules in projection images of the digital chest phantom using high and low X-ray energies, soft tissue images obtained by energy subtraction, and "gold standard" images of the soft tissues. Using our method, the lung and bone regions were segmented on the original CT images. The contrast of simulated nodules in soft tissue images obtained by energy subtraction closely matched that obtained using the gold standard images. We thus conclude that it is possible to carry out simulation studies based on energy subtraction techniques using the created digital chest phantoms. Our method is potentially useful for performing simulation studies for optimizing the imaging parameters in chest X-ray examinations. PMID:24647055

  12. Digital subtraction cisternography: a new approach to fistula localisation in cerebrospinal fluid rhinorrhoea.

    PubMed Central

    Byrne, J V; Ingram, C E; MacVicar, D; Sullivan, F M; Uttley, D

    1990-01-01

    Positive contrast cisternography with digital subtraction of fluoroscopy images before computed tomography (CT) was employed in the investigation of eight patients with cerebrospinal fluid (CSF) rhinorrhoea. Fistulae were visualised by preliminary digital subtraction cisternography (DSC) in six patients and in five patients the sites of leakage were confirmed at surgery. Fluoroscopy facilitated interpretation of CT in all the positive studies and in two patients provided information which could not be deduced from CT cisternography (CTC) alone. The combined technique is recommended for the investigation of patients with recurrent and post operative CSF rhinorrhoea and when CTC alone fails to identify the site of leakage. Images PMID:2292701

  13. Applications of digital subtraction angiography in cardiovascular diagnosis.

    PubMed

    Myerowitz, P D; Swanson, D K; Turnipseed, W D

    1985-06-01

    Both intravenous and intra-arterial DSA have widespread applications in the field of cardiovascular diagnosis. The definition of carotid artery stenosis or severe peripheral vascular disease in the patient undergoing coronary artery bypass surgery might dictate the need for simultaneous carotid and coronary artery surgery or demonstrate the best route for insertion of an intra-aortic balloon. DSA also might find further application in the definition of thoracic aortic dissection, thoracic aortic trauma, and coarctation of the thoracic aorta, as well as in showing the adequacy of repair of thoracic coarctation in patients who remain hypertensive postoperatively. Left ventricular imaging using intravenous or intraventricular injections of contrast material provides an accurate method of calculating ejection fraction and an excellent picture of left ventricular wall motion. In addition, because smaller amounts of contrast material may be used for intraventricular infections, patients with renal failure or severe impairment of the left ventricle might fare better with the reduced contrast load. Multiple ventriculograms can be performed following interventions such as pacing or exercise to allow a more adequate definition of left ventricular performance. Intravenous DSA still has not achieved satisfactory visualization of the coronary arteries or coronary artery bypass grafts. However, aortic root injections of contrast material can provide adequate definition of these structures and has been recommended as a screening technique for coronary disease in patients undergoing arteriography for other vascular disease. Current work on the development of DSA techniques for the quantitation of coronary artery blood flow and myocardial perfusion is quite promising. Accurate, reproducible measurement of coronary artery blood flow, patterns of myocardial perfusion, and areas of myocardium supplied by specific coronary vessels with obstructions may soon provide physiologic

  14. Digital Subtraction Cystography for Detection of Communicating Holes of Spinal Extradural Arachnoid Cysts

    PubMed Central

    Gu, Kyowon; Kim, Eun-Sang

    2016-01-01

    Objective The purpose of this study was to demonstrate the usefulness of digital subtraction cystography to identify communicating holes between a spinal extradural arachnoid cyst (SEAC) and the subarachnoid space prior to cyst removal and hole closure. Materials and Methods Six patients with SEAC were enrolled in this retrospective study. Digital subtraction cystography and subsequent CT myelography were performed for every patient. The presence and location of the communicating holes on cystography were documented. We evaluated the MRI characteristics of the cysts, including location, size, and associated spinal cord compression; furthermore, we reviewed cystographic images, CT myelograms, procedural reports, and medical records for analysis. If surgery was performed after cystography, intraoperative findings were compared with preoperative cystography. Results The location of the communicating hole between the arachnoid cyst and the subarachnoid space was identified by digital subtraction cystography in all cases (n = 6). Surgical resection of SEAC was performed in 4 patients, and intraoperative location of the communicating hole exactly corresponded to the preoperative identification. Conclusion Fluoroscopic-guided cystography for SEAC accurately demonstrates the presence and location of dural defects. Preoperative digital subtraction cystography is useful for detection of a communicating hole between a cyst and the subarachnoid space. PMID:26798223

  15. [Evaluation of coronary blood flow using digital subtraction technique and cine coronary angiography: a preliminary report].

    PubMed

    Uwatoko, M; Miyagi, Y; Nomura, M; Shiga, Y; Koike, A; Tateishi, R; Mitsuguchi, F; Mano, K; Hishida, H; Mizuno, Y

    1988-06-01

    To evaluate coronary circulation in ischemic heart disease, digital image processing with cine coronary angiography was performed. Using time-density curves obtained from individual pixels, images showing the distribution of contrast density and transit time were obtained. To record angiograms, contrast medium was injected into the coronary artery in a steady manner during right atrial pacing. Frames in the end-diastolic phase immediately before the P wave were selected, and digitized into a 512 x 512 x 8 bit matrix using a system composed of a video camera, an analog-to-digital converter, and a computer. These digitized images were then stored in a disk memory. A mask image was prepared before the injection of contrast medium. Subtraction was performed using the mask image and a series of images following contrast injection. The subtracted images were of sufficient quality to permit clear observation of the individual coronary arterial branches. Time-density curves were then determined from these subtracted images. From these curves, time from the onset of contrast injection to its peak density (Tp), time from the peak density to the half peak density (T 1/2) and the attenuation factor of the curves (tau) were derived. Their distributions were expressed as color images. Examples of a normal control and a case of inferior infarction were demonstrated. Blood flow function images with good spatial resolution were thus obtained. This method is useful for evaluating coronary blood flow. PMID:2977791

  16. Digital subtraction myelography for the identification of spontaneous spinal CSF-venous fistulas.

    PubMed

    Schievink, Wouter I; Moser, Franklin G; Maya, M Marcel; Prasad, Ravi S

    2016-06-01

    OBJECTIVE In most patients with spontaneous intracranial hypotension, a spinal CSF leak can be found, but occasionally, no leak can be demonstrated despite extensive spinal imaging. Failure to localize a CSF leak limits treatment options. The authors recently reported the discovery of CSF-venous fistulas in patients with spontaneous intracranial hypotension and now report on the use of digital subtraction myelography in patients with spontaneous intracranial hypotension but no CSF leak identifiable on conventional spinal imaging (i.e., non-digital subtraction myelography). METHODS The patient population consisted of 53 consecutive patients with spontaneous intracranial hypotension who underwent digital subtraction myelography but in whom no spinal CSF leak (i.e., presence of extradural CSF) was identifiable on conventional spinal imaging. RESULTS The mean age of the 33 women and 20 men was 53.4 years (range 29-71 years). A CSF-venous fistula was demonstrated in 10 (19%) of the 53 patients. A CSF-venous fistula was found in 9 (27%) of the 33 women and in 1 (5%) of the 20 men (p = 0.0697). One patient was treated successfully with percutaneous injection of fibrin sealant. Nine patients underwent surgery for the fistula. Surgery resulted in complete resolution of symptoms in 8 patients (follow-up 7-25 months), and in 1 patient, symptoms recurred after 4 months. CONCLUSIONS In this study, the authors found a CSF-venous fistula in approximately one-fifth of the patients with recalcitrant spontaneous intracranial hypotension but no CSF leak identifiable on conventional spinal imaging. The authors suggest that digital subtraction myelography be considered in this patient population. PMID:26849709

  17. Digital subtraction radiography evaluation of longitudinal bone density changes around immediate loading implants: a pilot study

    PubMed Central

    Carneiro, LS; da Cunha, HA; Leles, CR; Mendonça, EF

    2012-01-01

    Objective The aim of this study was to assess longitudinal quantitative changes in bone density around different implant loading protocols and implant surfaces measured by digital subtraction radiography (DSR). Methods 12 patients received bilateral homologous standard and TiUnite® (Nobel Biocare, Kloten, Switzerland) single-tooth implants under 2 implant—loading protocols: immediate loading (8 patients, 16 implants, 12 maxillary) and conventional loading (4 patients, 8 implants, 4 maxillary). Standardized periapical radiographs were taken immediately after implant placement (baseline image) and at the 3-month, 6-month and 12-month follow ups. Radiographic images were digitized and submitted to digital subtraction using the DSR system® (Electro Medical System, Nyon, Switzerland), resulting in three subtracted images. Quantitative analysis of bone density was performed using Image Tool® software (University of Texas Health Science Centre, San Antonio, TX) to assess pixel value changes in five areas around the implants (crestal, subcrestal, medial third, apical–lateral and apical). Results Repeated-measures analysis of variance showed that grey levels were significantly influenced by follow-up time and implant-loading protocol. A linear increase in grey levels was found for immediate loading (IML) implants and a significant decrease in grey levels was observed in the 12-month follow up for conventional loading implants. No effect of implant surface treatment was observed. Conclusion In conclusion, IML protocol induced mineral bone gain around single-tooth implants after the first year under function for cases with favourable bone conditions. PMID:22074866

  18. Strategies for Human Tumor Virus Discoveries: From Microscopic Observation to Digital Transcriptome Subtraction

    PubMed Central

    Mirvish, Ezra D.; Shuda, Masahiro

    2016-01-01

    Over 20% of human cancers worldwide are associated with infectious agents, including viruses, bacteria, and parasites. Various methods have been used to identify human tumor viruses, including electron microscopic observations of viral particles, immunologic screening, cDNA library screening, nucleic acid hybridization, consensus PCR, viral DNA array chip, and representational difference analysis. With the Human Genome Project, a large amount of genetic information from humans and other organisms has accumulated over the last decade. Utilizing the available genetic databases, Feng et al. (2007) developed digital transcriptome subtraction (DTS), an in silico method to sequentially subtract human sequences from tissue or cellular transcriptome, and discovered Merkel cell polyomavirus (MCV) from Merkel cell carcinoma. Here, we review the background and methods underlying the human tumor virus discoveries and explain how DTS was developed and used for the discovery of MCV. PMID:27242703

  19. Strategies for Human Tumor Virus Discoveries: From Microscopic Observation to Digital Transcriptome Subtraction.

    PubMed

    Mirvish, Ezra D; Shuda, Masahiro

    2016-01-01

    Over 20% of human cancers worldwide are associated with infectious agents, including viruses, bacteria, and parasites. Various methods have been used to identify human tumor viruses, including electron microscopic observations of viral particles, immunologic screening, cDNA library screening, nucleic acid hybridization, consensus PCR, viral DNA array chip, and representational difference analysis. With the Human Genome Project, a large amount of genetic information from humans and other organisms has accumulated over the last decade. Utilizing the available genetic databases, Feng et al. (2007) developed digital transcriptome subtraction (DTS), an in silico method to sequentially subtract human sequences from tissue or cellular transcriptome, and discovered Merkel cell polyomavirus (MCV) from Merkel cell carcinoma. Here, we review the background and methods underlying the human tumor virus discoveries and explain how DTS was developed and used for the discovery of MCV. PMID:27242703

  20. Intravenous Angiocardiography Using Digital Image Processing: Experience With Axial Projections In Normal Pigs And In Pigs With Experimentally Generated Left-To-Right Shunts

    NASA Astrophysics Data System (ADS)

    Bogren, Hugo G.; Bursch, Joachim H.; Brennecke, Rudiger; Heintzen, Paul H.

    1981-11-01

    Computerized digitization and processing of roentgen video images recorded at a rate of 50 per second was tested in intravenous angiocardiography in normal pigs weighing 15 to 20 kg. Roentgen video images were recorded in the 4-chamber view obtained by 30-35 degrees caudocranial angulation of the x-ray tube and 50-60 degrees LAO obliquity in the pig. Significant contrast enhancement was obtained through ECG-gated background subtraction and rescaling after integration of multiple background as well as contrast images. Occasionally, histogram equalization was used to further enhance contrast. To study temporal changes in cardiac motion, time parameter extraction or functional imaging was applied as well. The left and right heart were well visualized after intravenous injection of 1/3-1 cc. 76% Urografin per kg. bodyweight. Special purpose processing like subtraction of the end systolic phase from the end diastolic in the left and right ventricles as well as subtraction of the right ventricular phase from the left ventricular phase was also performed. If the left ventricular end systolic phase was subtracted from the end diastolic, most of the left atrium was also subtracted whereby the left ventricle was seen without continuity or superimposition of the left atrium. Experimentally generated ventricular and atrial septal defects as well as patent ductus arteriosus could be detected using the described technique. The results of the animal experiments became the basis for subsequent applications in children with congenital heart disease.

  1. Digital Subtraction Phonocardiography (DSP) applied to the detection and characterization of heart murmurs

    PubMed Central

    2011-01-01

    Background During the cardiac cycle, the heart normally produces repeatable physiological sounds. However, under pathologic conditions, such as with heart valve stenosis or a ventricular septal defect, blood flow turbulence leads to the production of additional sounds, called murmurs. Murmurs are random in nature, while the underlying heart sounds are not (being deterministic). Innovation We show that a new analytical technique, which we call Digital Subtraction Phonocardiography (DSP), can be used to separate the random murmur component of the phonocardiogram from the underlying deterministic heart sounds. Methods We digitally recorded the phonocardiogram from the anterior chest wall in 60 infants and adults using a high-speed USB interface and the program Gold Wave http://www.goldwave.com. The recordings included individuals with cardiac structural disease as well as recordings from normal individuals and from individuals with innocent heart murmurs. Digital Subtraction Analysis of the signal was performed using a custom computer program called Murmurgram. In essence, this program subtracts the recorded sound from two adjacent cardiac cycles to produce a difference signal, herein called a "murmurgram". Other software used included Spectrogram (Version 16), GoldWave (Version 5.55) as well as custom MATLAB code. Results Our preliminary data is presented as a series of eight cases. These cases show how advanced signal processing techniques can be used to separate heart sounds from murmurs. Note that these results are preliminary in that normal ranges for obtained test results have not yet been established. Conclusions Cardiac murmurs can be separated from underlying deterministic heart sounds using DSP. DSP has the potential to become a reliable and economical new diagnostic approach to screening for structural heart disease. However, DSP must be further evaluated in a large series of patients with well-characterized pathology to determine its clinical potential

  2. Digital subtraction angiography of the pulmonary arteries for the diagnosis of pulmonary embolism

    SciTech Connect

    Ludwig, J.W.; Verhoeven, L.A.J.; Kersbergen, J.J.; Overtoom, T.T.C.

    1983-06-01

    A comparative study of radionuclide scanning (perfusion studies in all 18 patients and ventilation studies in 9) and digital subtraction angiography (DSA) was performed in 18 patients with suspected pulmonary thromboembolism. In 17 patients good visualization of the arteries was obtained with DSA; 10 of these patients had no pre-existing lung disease, and 7 had chronic obstructive pulmonary disease (COPD). The information provided by DSA in this small group was equal to or better than that of scintigraphy, especially in patients with COPD, and the reliability of DSA was superior to that of the radionuclide scintigraphy. Methods for preventing motion artifacts with DSA are also described.

  3. Inferior vena cava leiomyosarcoma confirmed by catheter suction biopsy during digital subtraction angiography.

    PubMed

    Wei, Ning; Xu, Xiang-Dong; Xu, Hao; Zu, Mao-Heng

    2014-01-01

    Leiomyosarcoma of vascular origin is a rare disease and most cases arise in the inferior vena cava. Inferior vena cava leiomyosarcoma (IVCLMS) usually presents in females in their sixth decade of life. The clinical symptoms are often non-specific and the diagnosis is often delayed. Current imaging techniques can accurately differentiate inferior vena cava neoplasms from other non-neoplastic lesions. However, definitive diagnosis of IVCLMS needs histologic evidence. We report a case of IVCLMS in a 61-year old Chinese woman. This is the first IVCLMS case confirmed by catheter suction biopsy during digital subtraction angiography. PMID:25232438

  4. Pulsed-injection method for blood flow velocity measurement in intraarterial digital subtraction angiography.

    PubMed

    Shaw, C G; Plewes, D B

    1986-08-01

    The pulsed-injection method for measuring the velocity of blood flow in intraarterial digital subtraction angiography is described. With this technique, contrast material is injected at a pulsing frequency as high as 15 Hz, so that two or more boluses can be imaged simultaneously. The velocity of flow is determined by measuring the spacing between the boluses and multiplying it by the pulsing frequency. Results of tests with phantoms correlate well with flow measurements obtained with a graduated cylinder for velocities ranging from 8 to 60 cm/sec. The potential of the method for time-dependent velocity measurement has been demonstrated with simulated pulsatile flows. PMID:3523598

  5. Anatomic and functional imaging of congenital heart disease with digital subtraction angiography

    SciTech Connect

    Buonocore, E.; Pavlicek, W.; Modic, M.T.; Meaney, T.F.; O'Donovan, P.B.; Grossman, L.B.; Moodie, D.S.; Yiannikas, J.

    1983-06-01

    Digital subtraction angiography (DSA) of the heart was performed in 54 patients for the evaluation of congenital heart diagnostic images and accurate physiologic shunt data that compared favorably with catheter angiography and nuclear medicine studies. Retrospective analysis of this series of patients indicated that DSA studies contributed sufficient informantion to shorten significantly or modify cardiac catheterization in 85% (79/93) of the defects that were identified. Interatrial septal defects were particularly well diagnosed, with identification occurring in 10 of 10 cases, wheseas intraventricular septal defects were identified in only 6 of 9 patients. Evaluation of postsurgical patients was accurate in 19 of 20 cases.

  6. How number line estimation skills relate to neural activations in single digit subtraction problems.

    PubMed

    Berteletti, I; Man, G; Booth, J R

    2015-02-15

    The Number Line (NL) task requires judging the relative numerical magnitude of a number and estimating its value spatially on a continuous line. Children's skill on this task has been shown to correlate with and predict future mathematical competence. Neurofunctionally, this task has been shown to rely on brain regions involved in numerical processing. However, there is no direct evidence that performance on the NL task is related to brain areas recruited during arithmetical processing and that these areas are domain-specific to numerical processing. In this study, we test whether 8- to 14-year-old's behavioral performance on the NL task is related to fMRI activation during small and large single-digit subtraction problems. Domain-specific areas for numerical processing were independently localized through a numerosity judgment task. Results show a direct relation between NL estimation performance and the amount of the activation in key areas for arithmetical processing. Better NL estimators showed a larger problem size effect than poorer NL estimators in numerical magnitude (i.e., intraparietal sulcus) and visuospatial areas (i.e., posterior superior parietal lobules), marked by less activation for small problems. In addition, the direction of the activation with problem size within the IPS was associated with differences in accuracies for small subtraction problems. This study is the first to show that performance in the NL task, i.e. estimating the spatial position of a number on an interval, correlates with brain activity observed during single-digit subtraction problem in regions thought to be involved in numerical magnitude and spatial processes. PMID:25497398

  7. [Development of a prevention of body movement fixation appliance in leg digital subtraction angiography].

    PubMed

    Yasuda, Mitsuyoshi; Kato, Kyouichi; Sakiyama, Koushi; Uchiyama, Yushi; Asanuma, Shinichi; Fujimura, Kazumasa; Suzuki, Hiroshi; Nakazawa, Yasuo

    2010-01-20

    In the peripheral angiography to evaluate blood flow below the knee levels in patients with arteriosclerosis obliterans, a motion artifact occurs as a result of body movements of a patient in normal fixation. This sometimes makes a correct evaluation difficult. Therefore, we developed a fixed appliance which can restrain body movement without affecting image quality and blood flow in digital subtraction angiography of a leg. The appliance is filled with the styrofoam of 1 mm diameter in a sealed bag, after air is aspirated from inside the bag. The appliance is stiffened to fit the shape of the crus. We measured signal to noise ratio / contrast to noise ratio / a resolution limit by visual evaluation to examine the influence of the image before and after usage of this appliance. In addition, the blood velocity of the dorsalis artery in ultrasound was measured to examine the effect on the blood flow. As a result, the fixed appliance did not affect blood flow in peripheral angiography to evaluate the clinical significance, the usual 5-point evaluate scale was used. The scale was significantly improved (p <0.01) after usage of this appliance. The newly developed fixed appliance for digital subtraction angiography of a leg is useful to avoid motion artifacts in clinical settings. PMID:20145364

  8. Comparison of the diagnostic accuracy of direct digital radiography system, filtered images, and subtraction radiography

    PubMed Central

    Takeshita, Wilton Mitsunari; Vessoni Iwaki, Lilian Cristina; Da Silva, Mariliani Chicarelli; Filho, Liogi Iwaki; Queiroz, Alfredo De Franco; Geron, Lucas Bachegas Gomes

    2013-01-01

    Background: To compare the diagnostic accuracy of three different imaging systems: Direct digital radiography system (DDR-CMOS), four types of filtered images, and a priori and a posteriori registration of digital subtraction radiography (DSR) in the diagnosis of proximal defects. Materials and Methods: The teeth were arranged in pairs in 10 blocks of vinyl polysiloxane, and proximal defects were performed with drills of 0.25, 0.5, and 1 mm diameter. Kodak RVG 6100 sensor was used to capture the images. A posteriori DSR registrations were done with Regeemy 0.2.43 and subtraction with Image Tool 3.0. Filtered images were obtained with Kodak Dental Imaging 6.1 software. Images (n = 360) were evaluated by three raters, all experts in dental radiology. Results: Sensitivity and specificity of the area under the receiver operator characteristic (ROC) curve (Az) were higher for DSR images with all three drills (Az = 0.896, 0.979, and 1.000 for drills 0.25, 0.5, and 1 mm, respectively). The highest values were found for 1-mm drills and the lowest for 0.25-mm drills, with negative filter having the lowest values of all (Az = 0.631). Conclusion: The best method of diagnosis was by using a DSR. The negative filter obtained the worst results. Larger drills showed the highest sensitivity and specificity values of the area under the ROC curve. PMID:24124300

  9. Intravenous pyelogram artefacts unique to digital tomosynthesis reconstruction.

    PubMed

    Rowberry, B K; Galea, A

    2011-11-01

    Recent advances in technology have led to the realisation of digital tomosynthesis (DT) imaging in routine investigations such as intravenous pyelogram (IVP). The major advantage this technology has over other technologies is its ability to perform a retrospective reconstruction of an arbitrary number of coronal image planes from a single data set consisting of a series of low dose discrete projections acquired over a limited angular range using a stationary detector. It is well documented that because DT relies on an angular limited acquisition, the data set is incomplete. This, in combination with the image reconstruction algorithm, results in reconstructed images containing non-focused information from outside the immediate focal plane. This article describes and suggests the cause of two artefacts unique to DT that cannot be explained by blurring alone. We believe the two artefacts are caused by breathing during data acquisition together with a combination of other factors, including the anatomy of the renal system, the method of data acquisition and the reconstructive algorithm used. This could lead to the unaware reporting radiologist falsely diagnosing a duplex collecting system. To avoid these artefacts, we recommend DT IVP should only be used in patients who can adequately perform a breath-hold for the duration of the data acquisition. In addition, we suggest that the study should be performed with breath-held following expiration. PMID:22011833

  10. Novel method for digital subtraction of tagged stool in virtual colonoscopy

    NASA Astrophysics Data System (ADS)

    Guendel, Lutz; Suehling, Michael; Eckert, Helmut

    2008-03-01

    Colon cancer is one of the most frequent causes of death. CT colonography is a novel method for the detection of polyps and early cancer. The general principle of CT colonography includes a cathartic bowel preparation. The resulting discomfort for patients leads to limited patient acceptance and therefore to limited cancer detection rates. Reduced bowel preparation, techniques for stool tagging, and electronic cleansing, however, improve the acceptance rates. Hereby, the high density of oral contrast material highlights residual stool and can be digitally removed. Known subtraction methods cause artifacts: additional 3D objects are introduced and small bowel folds are perforated. We propose a new algorithm that is based on the 2 nd derivative of the image data using the Hessian matrix and the following principal axis transform to detect tiny folds which shall not be subtracted together with tagged stool found by a thresholding method. Since the stool is usually not homogenously tagged with contrast media a detection algorithm for island-like structures is incorporated. The interfaces of air-stool level and colon wall are detected by a 3-dimensional difference of Gaussian module. A 3-dimensional filter smoothes the transitions between removed stool and colon tissue. We evaluated the efficacy of the new algorithm with 10 patient data sets. The results showed no introduced artificial objects and no perforated folds. The artifacts at the air-stool and colon tissue-stool transitions are considerably reduced compared to those known from the literature.

  11. Intra-arterial digital subtraction angiogrpahy: comparison with conventional hepatic arteriography

    SciTech Connect

    Flannigan, B.D.; Gomes, A.S.; Stambuk, E.C.; Lois, J.F.; Pais, S.O.

    1983-07-01

    To evaluate the efficacy of arterial digital subtraction angiography (DSA), 28 patients with a variety of hepatic lesions underwent intra-arterial DSA immediately following conventional celiac or hepatic arteriography. Thirty-one studies were obtained and the results of DSA were compared with the conventional arteriograms. DSA showed good visualization of the arteries in the early arterial phase of the examination. The late arterial phase was better evaluated on conventional arteriograms due to the decreased spatial resolution of DSA. Arterial DSA was most useful in the evaluation of the parenchyma of the liver; the use of remasking techniques allowed improved visualization of hepatic lesions, particularly in the left lobe of the liver. It is concluded that arterial DSA is useful in hepatic imaging and may supplant conventional hepatic arteriography as the technology improves.

  12. A 3D space-time motion evaluation for image registration in digital subtraction angiography.

    PubMed

    Taleb, N; Bentoutou, Y; Deforges, O; Taleb, M

    2001-01-01

    In modern clinical practice, Digital Subtraction Angiography (DSA) is a powerful technique for the visualization of blood vessels in a sequence of X-ray images. A serious problem encountered in this technique is the presence of artifacts due to patient motion. The resulting artifacts frequently lead to misdiagnosis or rejection of a DSA image sequence. In this paper, a new technique for removing both global and local motion artifacts is presented. It is based on a 3D space-time motion evaluation for separating pixels changing values because of motion from those changing values because of contrast flow. This technique is proved to be very efficient to correct for patient motion artifacts and is computationally cheap. Experimental results with several clinical data sets show that this technique is very fast and results in higher quality images. PMID:11179698

  13. All-optical digital logic: Full addition or subtraction on a three-state system

    SciTech Connect

    Remacle, F.; Levine, R. D.

    2006-03-15

    Stimulated Raman adiabatic passage (STIRAP) is a well-studied pump-probe control scheme for manipulating the population of quantum states of atoms or molecules. By encoding the digits to be operated on as 'on' or 'off' laser input signals we show how STIRAP can be used to implement a finite-state logic machine. The physical conditions required for an effective STIRAP operation are related to the physical conditions expected for a logic machine. In particular, a condition is derived on the mean number of photons that represent an on pulse. A finite-state machine computes Boolean expressions that depend both on the input and on the present state of the machine. With two input signals we show how to implement a full adder where the carry-in digit is stored in the state of the machine. Furthermore, we show that it is possible to store the carry-out digit as the next state and thereby return the machine to a state ready for the next full addition. Such a machine operates as a cyclical full adder. We further show how this full adder can equally well be operated as a full subtractor. To the best of our knowledge this is the first example of a nanosized system that implements a full subtraction.

  14. [Improved reproducibility of contrast echocardiography by SH U 454. Experimental studies using digital subtraction echocardiography].

    PubMed

    Grube, E; Fritzsch, T

    1986-06-01

    The right heart chambers of 10 animals were contrasted by conventional (NaCl, CO2, H2O2, indocyanine green (ICG), haemaccel) and a newly developed echo-contrast medium (SH U 454) and studied by 2-D echocardiography. By means of digital subtraction echocardiography (DSE) endocardial borders were defined automatically and the results were compared with the manual input of endocardial borders of original and contrast echocardiograms. The area enclosed by these borders served as basis for the calculation of reproducibility (in %) and correlations. The following correlation coefficients (r) and SEE were calculated between the areas defined by the different contrast media and DSE and manually derived borders: r = 0.85, 3.98 cm2 (ICG), and 0.89, 1.00 cm2 (haemaccel). The best calculations were found using SH U 454 in concentrations between 100 and 300 mg/ml. The correlation coefficients were in the range of r = 0.95 and 0.98 with an SEE of 0.21 to 0.56 cm2 between manually and automatically derived contours. Comparing the reproducibility of data between the different evaluation methods we found the following results: manual input of endocardial borders in original echocardiograms 12.3%-16.9%; manual definition of endocardial borders in contrast echocardiograms 2.0% (SH U 454) - 15.7% (CO2); automatic contour finding in original echocardiograms 8.6%-28.9% (mean 21.6%); automatic definition of endocardium by DSE in contrast echocardiograms 7.6% (ICG) - 0.9% (SH U 454, 300 mg/ml). Our results demonstrate that digital subtraction echocardiography is a simple an safe procedure to define endocardial contours if echo contrast media lead to a uniform and homogeneous opacification of the left and right cardiac cavities.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3529670

  15. Diagnostic effects of edge sharpening filtration and magnification on digitally subtracted renal images.

    PubMed

    Kimme-Smith, C; Gomes, A S; Cochran, S T; Barbaric, Z L; Lois, J F

    1986-01-01

    The improved appearance of digital radiographs filtered to improve local contrast and sharpen edges has not increased acceptance of these images by radiologists. Furthermore, many radiologists assert that correct diagnosis is not improved with these filtered images. This study was designed to test this assertion for digital subtraction angiograms (DSA) of renal images. Four experiments are described. First, phantom studies identified filters and their parameters thought likely to be acceptable and useful in diagnosing renal images formed by DSA. Second, these filters and parameters were then tested on medical images to assess their acceptance by radiologists. Third, display modes of windowing, positive/negative presentation, and magnification were varied for filtered and unfiltered images to assess preferences of radiologists. Fourth, filtered and unfiltered magnified images were used to test improved diagnosis. In the final experiment, 148 images from 33 renal studies (15 normal, 18 abnormal) were magnified, gray level windowed, and filtered. Diagnosis was not improved by the two edge sharpening filters tested. PMID:3540567

  16. Improved Visualization of Intracranial Vessels with Intraoperative Coregistration of Rotational Digital Subtraction Angiography and Intraoperative 3D Ultrasound

    PubMed Central

    Podlesek, Dino; Meyer, Tobias; Morgenstern, Ute; Schackert, Gabriele; Kirsch, Matthias

    2015-01-01

    Introduction Ultrasound can visualize and update the vessel status in real time during cerebral vascular surgery. We studied the depiction of parent vessels and aneurysms with a high-resolution 3D intraoperative ultrasound imaging system during aneurysm clipping using rotational digital subtraction angiography as a reference. Methods We analyzed 3D intraoperative ultrasound in 39 patients with cerebral aneurysms to visualize the aneurysm intraoperatively and the nearby vascular tree before and after clipping. Simultaneous coregistration of preoperative subtraction angiography data with 3D intraoperative ultrasound was performed to verify the anatomical assignment. Results Intraoperative ultrasound detected 35 of 43 aneurysms (81%) in 39 patients. Thirty-nine intraoperative ultrasound measurements were matched with rotational digital subtraction angiography and were successfully reconstructed during the procedure. In 7 patients, the aneurysm was partially visualized by 3D-ioUS or was not in field of view. Post-clipping intraoperative ultrasound was obtained in 26 and successfully reconstructed in 18 patients (69%) despite clip related artefacts. The overlap between 3D-ioUS aneurysm volume and preoperative rDSA aneurysm volume resulted in a mean accuracy of 0.71 (Dice coefficient). Conclusions Intraoperative coregistration of 3D intraoperative ultrasound data with preoperative rotational digital subtraction angiography is possible with high accuracy. It allows the immediate visualization of vessels beyond the microscopic field, as well as parallel assessment of blood velocity, aneurysm and vascular tree configuration. Although spatial resolution is lower than for standard angiography, the method provides an excellent vascular overview, advantageous interpretation of 3D-ioUS and immediate intraoperative feedback of the vascular status. A prerequisite for understanding vascular intraoperative ultrasound is image quality and a successful match with preoperative

  17. Nonrigid Image Registration in Digital Subtraction Angiography Using Multilevel B-Spline

    PubMed Central

    2013-01-01

    We address the problem of motion artifact reduction in digital subtraction angiography (DSA) using image registration techniques. Most of registration algorithms proposed for application in DSA, have been designed for peripheral and cerebral angiography images in which we mainly deal with global rigid motions. These algorithms did not yield good results when applied to coronary angiography images because of complex nonrigid motions that exist in this type of angiography images. Multiresolution and iterative algorithms are proposed to cope with this problem, but these algorithms are associated with high computational cost which makes them not acceptable for real-time clinical applications. In this paper we propose a nonrigid image registration algorithm for coronary angiography images that is significantly faster than multiresolution and iterative blocking methods and outperforms competing algorithms evaluated on the same data sets. This algorithm is based on a sparse set of matched feature point pairs and the elastic registration is performed by means of multilevel B-spline image warping. Experimental results with several clinical data sets demonstrate the effectiveness of our approach. PMID:23971026

  18. A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT

    PubMed Central

    Badea, Cristian T.; Hedlund, Laurence W.; Johnson, G. Allan

    2013-01-01

    CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging. PMID:27006920

  19. Increasing Efficacy of Thrombectomy by Using Digital Subtraction Angiography to Confirm Stent Retriever Clot Integration.

    PubMed

    Simon, Scott; Langan, Sara; Cooke, Jonathon

    2016-01-01

    Physicians performing thrombectomy for acute stroke have had increasing success as thrombectomy-specific devices have continued to evolve. As the devices evolve, so too must the techniques. The current generation of stent retriever thrombectomy devices requires five minutes of dwell time, regardless of the particularities of the case. We have noticed the presence of flow through the stent immediately prior to removal portends a lower chance of successful thrombus retrieval than when no flow is seen, regardless of dwell time. We hypothesize that interventionalists can use the presence or absence of flow to predict adequacy of seating time and decrease the number of deployments per case. This could significantly decrease time to recanalization by avoiding time-consuming, unsuccessful pulls. This is a technical report of a few cases of stent retriever thrombectomy. We propose using post-deployment digital subtraction angiography to confirm thrombus-device integration and increase the chance of thrombus removal. PMID:27182473

  20. Nonrigid image registration in digital subtraction angiography using multilevel B-spline.

    PubMed

    Nejati, Mansour; Sadri, Saeid; Amirfattahi, Rassoul

    2013-01-01

    We address the problem of motion artifact reduction in digital subtraction angiography (DSA) using image registration techniques. Most of registration algorithms proposed for application in DSA, have been designed for peripheral and cerebral angiography images in which we mainly deal with global rigid motions. These algorithms did not yield good results when applied to coronary angiography images because of complex nonrigid motions that exist in this type of angiography images. Multiresolution and iterative algorithms are proposed to cope with this problem, but these algorithms are associated with high computational cost which makes them not acceptable for real-time clinical applications. In this paper we propose a nonrigid image registration algorithm for coronary angiography images that is significantly faster than multiresolution and iterative blocking methods and outperforms competing algorithms evaluated on the same data sets. This algorithm is based on a sparse set of matched feature point pairs and the elastic registration is performed by means of multilevel B-spline image warping. Experimental results with several clinical data sets demonstrate the effectiveness of our approach. PMID:23971026

  1. Failing Hemodialysis Arteriovenous Fistula and Percutaneous Treatment: Imaging with CT, MRI and Digital Subtraction Angiography

    SciTech Connect

    Cavagna, Enrico; D'Andrea, Paolo; Schiavon, Francesco; Tarroni, Giovanni

    2000-07-15

    Purpose: To evaluate failing hemodialysis arteriovenous fistulas with helical CT angiography (CTA), MR angiography (MRA), and digital subtraction angiography (DSA), and to compare the efficacy of the three techniques in detecting the number, location, grade, and extent of stenoses and in assessing the technical results of percutaneous transluminal angioplasty (PTA) and stenting.Methods: Thirteen patients with Brescia-Cimino arteriovenous fistula malfunction underwent MRA and CTA of the fistula and, within 1 week, DSA. A total of 11 PTAs were performed; in three cases an MR-compatible stent was placed. DSA served as the gold standard for comparison in all patients. The presence, site, and number of stenoses or occlusions and the technical results of percutaneous procedures were assessed with DSA, CTA, and MRA.Results: MRA underestimated a single stenosis in one patient; CTA and MRA did not overestimate any stenosis. Significant artifacts related to stent geometry and/or underlying metal were seen in MRA sequences in two cases.Conclusions: CT and MRI can provide information regarding the degree of vascular impairment, helping to stratify patients into those who can have PTA (single or multiple stenoses) versus those who require an operative procedure (occlusion). Conventional angiography can be reserved for candidates for percutaneous intervention.

  2. Patient radiation dose from computed tomography angiography and digital subtraction angiography of the brain

    NASA Astrophysics Data System (ADS)

    Netwong, Y.; Krisanachinda, A.

    2016-03-01

    The 64-row multidetector computed tomography angiography (64-MDCTA) provides vascular image quality of the brain similar to digital subtraction angiography (DSA), but the effective dose of CTA is lower than DSA studied in phantom. The purpose of this study is to evaluate the effective dose from 64-MDCTA and DSA. Effective dose (according to ICRP 103) from 64-MDCTA and DSA flat panel detector for cerebral vessels examination of the brain using standard protocols as recommended by the manufacturer was calculated for 30 cases of MDCTA (15 male and 15 female).The mean patient age was 49.5 (23-89) yrs. 30 cases of DSA (14 male and 16 female), the mean patient age was 46.8 (21-81) yrs. For CTA, the mean effective dose was 3.7 (2.82- 5.19) mSv. For DSA, the mean effective dose was 5.78 (3.3-10.06) mSv. The effective dose of CTA depends on the scanning protocol and scan length. Low tube current can reduce patient dose whereas the number of exposures and number of series in 3D rotational angiography (3D RA) resulted in increasing effective dose in DSA patients.

  3. Remapping of digital subtraction angiography on a standard fluoroscopy system using 2D-3D registration

    NASA Astrophysics Data System (ADS)

    Alhrishy, Mazen G.; Varnavas, Andreas; Guyot, Alexis; Carrell, Tom; King, Andrew; Penney, Graeme

    2015-03-01

    Fluoroscopy-guided endovascular interventions are being performing for more and more complex cases with longer screening times. However, X-ray is much better at visualizing interventional devices and dense structures compared to vasculature. To visualise vasculature, angiography screening is essential but requires the use of iodinated contrast medium (ICM) which is nephrotoxic. Acute kidney injury is the main life-threatening complication of ICM. Digital subtraction angiography (DSA) is also often a major contributor to overall patient radiation dose (81% reported). Furthermore, a DSA image is only valid for the current interventional view and not the new view once the C-arm is moved. In this paper, we propose the use of 2D-3D image registration between intraoperative images and the preoperative CT volume to facilitate DSA remapping using a standard fluoroscopy system. This allows repeated ICM-free DSA and has the potential to enable a reduction in ICM usage and radiation dose. Experiments were carried out using 9 clinical datasets. In total, 41 DSA images were remapped. For each dataset, the maximum and averaged remapping accuracy error were calculated and presented. Numerical results showed an overall averaged error of 2.50 mm, with 7 patients scoring averaged errors < 3 mm and 2 patients < 6 mm.

  4. In Vivo Small Animal Imaging using Micro-CT and Digital Subtraction Angiography

    PubMed Central

    Badea, C.T.; Drangova, M.; Holdsworth, D.W.; Johnson, G.A.

    2009-01-01

    Small animal imaging has a critical role in phenotyping, drug discovery, and in providing a basic understanding of mechanisms of disease. Translating imaging methods from humans to small animals is not an easy task. The purpose of this work is to review in vivo X-ray based small animal imaging, with a focus on in vivo micro-computed tomography (micro-CT) and digital subtraction angiography (DSA). We present the principles, technologies, image quality parameters and types of applications. We show that both methods can be used not only to provide morphological, but also functional information, such as cardiac function estimation or perfusion. Compared to other modalities, x-ray based imaging is usually regarded as being able to provide higher throughput at lower cost and adequate resolution. The limitations are usually associated with the relatively poor contrast mechanisms and potential radiation damage due to ionizing radiation, although the use of contrast agents and careful design of studies can address these limitations. We hope that the information will effectively address how x-ray based imaging can be exploited for successful in vivo preclinical imaging. PMID:18758005

  5. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data.

    PubMed

    Spiegel, M; Redel, T; Struffert, T; Hornegger, J; Doerfler, A

    2011-10-01

    Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling. PMID:21908904

  6. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data

    NASA Astrophysics Data System (ADS)

    Spiegel, M.; Redel, T.; Struffert, T.; Hornegger, J.; Doerfler, A.

    2011-10-01

    Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.

  7. Interventional digital subtraction angiography for small bowel gastrointestinal stromal tumors with bleeding

    PubMed Central

    Chen, Yao-Ting; Sun, Hong-Liang; Luo, Jiang-Hong; Ni, Jia-Yan; Chen, Dong; Jiang, Xiong-Ying; Zhou, Jing-Xing; Xu, Lin-Feng

    2014-01-01

    AIM: To retrospectively evaluate the diagnostic efficacy of interventional digital subtraction angiography (DSA) for bleeding small bowel gastrointestinal stromal tumors (GISTs). METHODS: Between January 2006 and December 2013, small bowel tumors in 25 consecutive patients undergoing emergency interventional DSA were histopathologically confirmed as GIST after surgical resection. The medical records of these patients and the effects of interventional DSA and the presentation and management of the condition were retrospectively reviewed. RESULTS: Of the 25 patients with an age range from 34- to 70-year-old (mean: 54 ± 12 years), 8 were male and 17 were female. Obscure gastrointestinal bleeding, including tarry or bloody stool and intermittent melena, was observed in all cases, and one case also involved hematemesis. Nineteen patients required acute blood transfusion. There were a total of 28 small bowel tumors detected by DSA. Among these, 20 were located in the jejunum and 8 were located in the ileum. The DSA characteristics of the GISTs included a hypervascular mass of well-defined, homogeneous enhancement and early developed draining veins. One case involved a complication of intussusception of the small intestine that was discovered during surgery. No pseudoaneurysms, arteriovenous malformations or fistulae, or arterial rupture were observed. The completely excised size was approximately 1.20 to 5.50 cm (mean: 3.05 ± 1.25 cm) in maximum diameter based on measurements after the resection. There were ulcerations (n = 8), erosions (n = 10), hyperemia and edema (n = 10) on the intra-luminal side of the tumors. Eight tumors in patients with a large amount of blood loss were treated with transcatheter arterial embolization with gelfoam particles during interventional DSA. CONCLUSION: Emergency interventional DSA is a useful imaging option for locating and diagnosing small bowel GISTs in patients with bleeding, and is an effective treatment modality. PMID:25548494

  8. Accurate, fully-automated registration of coronary arteries for volumetric CT digital subtraction angiography

    NASA Astrophysics Data System (ADS)

    Razeto, Marco; Mohr, Brian; Arakita, Kazumasa; Schuijf, Joanne D.; Fuchs, Andreas; Kühl, J. Tobias; Chen, Marcus Y.; Kofoed, Klaus F.

    2014-03-01

    Diagnosis of coronary artery disease with Coronary Computed Tomography Angiography (CCTA) is complicated by the presence of signi cant calci cation or stents. Volumetric CT Digital Subtraction Angiography (CTDSA) has recently been shown to be e ective at overcoming these limitations. Precise registration of structures is essential as any misalignment can produce artifacts potentially inhibiting clinical interpretation of the data. The fully-automated registration method described in this paper addresses the problem by combining a dense deformation eld with rigid-body transformations where calci cations/stents are present. The method contains non-rigid and rigid components. Non-rigid registration recovers the majority of motion artifacts and produces a dense deformation eld valid over the entire scan domain. Discrete domains are identi ed in which rigid registrations very accurately align each calci cation/stent. These rigid-body transformations are combined within the immediate area of the deformation eld using a distance transform to minimize distortion of the surrounding tissue. A recent interim analysis of a clinical feasibility study evaluated reader con dence and diagnostic accuracy in conventional CCTA and CTDSA registered using this method. Conventional invasive coronary angiography was used as the reference. The study included 27 patients scanned with a second-generation 320-row CT detector in which 41 lesions were identi ed. Compared to conventional CCTA, CTDSA improved reader con dence in 13/36 (36%) of segments with severe calci cation and 3/5 (60%) of segments with coronary stents. Also, the false positive rate of CTDSA was reduced compared to conventional CCTA from 18% (24/130) to 14% (19/130).

  9. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    SciTech Connect

    Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan

    2009-11-15

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  10. Estimating breast thickness for dual-energy subtraction in contrast-enhanced digital mammography using calibration phantoms

    NASA Astrophysics Data System (ADS)

    Lau, Kristen C.; Kwon, Young Joon; Aziz, Moez Karim; Acciavatti, Raymond J.; Maidment, Andrew D. A.

    2016-04-01

    Dual-energy contrast-enhanced digital mammography (DE CE-DM) uses an iodinated contrast agent to image the perfusion and vasculature of the breast. DE images are obtained by a weighted logarithmic subtraction of the high-energy (HE) and low-energy (LE) image pairs. We hypothesized that the optimal DE subtraction weighting factor is thickness-dependent, and developed a method for determining breast tissue composition and thickness in DE CE-DM. Phantoms were constructed using uniform blocks of 100% glandular-equivalent and 100% adipose-equivalent material. The thickness of the phantoms ranged from 3 to 8 cm, in 1 cm increments. For a given thickness, the glandular-adipose composition of the phantom was varied using different combinations of blocks. The logarithmic LE and logarithmic HE signal intensities were measured; they decrease linearly with increasing glandularity for a given thickness. The signals decrease with increasing phantom thickness and the x-ray signal decreases linearly with thickness for a given glandularity. As the thickness increases, the attenuation difference per additional glandular block decreases, indicating beam hardening. From the calibration mapping, we have demonstrated that we can predict percent glandular tissue and thickness when given two distinct signal intensities. Our results facilitate the subtraction of tissue at the boundaries of the breast, and aid in discriminating between contrast agent uptake in glandular tissue and subtraction artifacts.

  11. Supine Digital Subtraction Myelography for the Demonstration of a Dorsal Cerebrospinal Fluid Leak in a Patient with Spontaneous Intracranial Hypotension: A Technical Note

    PubMed Central

    Carstensen, Michael; Chaudhary, Navjot; Leung, Andrew; Ng, Wai

    2012-01-01

    A patient with spontaneous intracranial hypotension due to a spinal cerebrospinal fluid (CSF) leak required localization of the leakage site prior to surgical management. Conventional, computed tomography and prone digital subtraction myelography failed to localize the dural tear, which was postulated to be dorsally located. We present here a digital subtraction myelographic approach to accurately localize a dorsal site of CSF leakage by injecting iodinated contrast via a lumbar drain with the patient in the supine position. PMID:23378882

  12. Projection-based energy weighting on photon-counting X-ray images in digital subtraction mammography: a feasibility study

    NASA Astrophysics Data System (ADS)

    Choi, Sung-Hoon; Lee, Seung-Wan; Choi, Yu-Na; Lee, Young-Jin; Kim, Hee-Joung

    2014-03-01

    In digital subtraction mammography where subtracts the one image (with contrast medium) from the other (anatomical background) for observing the tumor structure, tumors which include more blood vessels than normal tissue could be distinguished through the enhancement of contrast-to-noise ratio (CNR). In order to improve CNR, we adopted projection-based energy weighting for iodine solutions with four different concentrations embedded in a breast phantom (50% adipose and 50% glandular tissues). In this study, a Monte Carlo simulation was used to simulate a 40 mm thickness breast phantom, which has 15 and 30 mg/cm3 iodine solutions with two different thicknesses, and an energy resolving photon-counting system. The input energy spectrum was simulated in a range of 20 to 45 keV in order to reject electronic noise and include k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy weighting improved the CNR by factors of 1.05-1.86 compared to the conventional integrating images. Consequently, the CNR of images from the digital subtraction mammography could be improved by the projection-based energy weighting with photon-counting detectors.

  13. Leiomyosarcoma of the Inferior Vena Cava Confirmed by Aspiration Biopsy With a Catheter During Digital Subtraction Angiography.

    PubMed

    Yakupoglu, Abdullah; Ulus, Sila; Cantasdemir, Murat

    2016-04-01

    Leiomyosarcoma of the vascular origin is a rare malignant tumor. It originates from the smooth muscle cells of the media with intra- or extraluminal growth, and in most cases it arises in the inferior vena cava. The diagnosis is often delayed because the clinical symptoms of this disease are often nonspecific. Accurate diagnosis of inferior vena cava leiomyosarcoma (IVCLMS) needs histologic confirmation. We report a case of IVCLMS histologically confirmed by aspiration biopsy with a catheter during digital subtraction angiography presenting with pulmonary emboli in a 65-year-old man. PMID:27000390

  14. Multimodality evaluation of dural arteriovenous fistula with CT angiography, MR with arterial spin labeling, and digital subtraction angiography: case report.

    PubMed

    Alexander, Matthew; McTaggart, Ryan; Santarelli, Justin; Fischbein, Nancy; Marks, Michael; Zaharchuk, Greg; Do, Huy

    2014-01-01

    Dural arteriovenous fistulae (DAVF) are cerebrovascular lesions with pathologic shunting into the venous system from arterial feeders. Digital subtraction angiography (DSA) has long been considered the gold standard for diagnosis, but advances in noninvasive imaging techniques now play a role in the diagnosis of these complex lesions. Herein, we describe the case of a patient with right-side pulsatile tinnitus and DAVF diagnosed using computed tomography angiography, magnetic resonance with arterial spin labeling, and DSA. Implications for imaging analysis of DAVFs and further research are discussed. PMID:23746119

  15. Phantom study to evaluate contrast-medium-enhanced digital subtraction mammography with a full-field indirect-detection system

    SciTech Connect

    Palma, B. A.; Rosado-Mendez, I.; Villasenor, Y.; Brandan, M. E.

    2010-02-15

    This phantom study simulates contrast-medium-enhanced digital subtraction mammography (CEDM) and compares subtracted image quality and total mean glandular dose for two alternative spectral combinations available in a GE Senographe DS mammography unit. The first choice takes advantage of large iodine attenuation at low photon energies and uses traditionally available spectra (anode/filter combinations Mo/Mo at 25 kV and Rh/Rh at 40 kV, ''Mo25-Rh40''). The second choice, selected from a previous analytical optimization, includes harder spectra obtained by adding external filtration to traditional beams (Rh/Rh at 34 kV and Rh/Rh+5 mm of Al at 45 kV, ''Rh34-Rh45H''). Individual images of a custom-made phantom containing tubes of various diameters filled with water- or iodine-based contrast agent were acquired with both spectral combinations. The total breast entrance air kerma, considering subtraction of two images, was limited to 8.76 mGy (1 R). The results were compared to predictions obtained through an analytical formalism that assumes noise of stochastic origin. Individual images were evaluated and subtracted under five combinations of temporal and dual-energy modalities. Signal variance analysis in individual raw images showed important contributions of nonstochastic origin, associated with the software applied to raw images, the curved geometry, and strong attenuation of the phantom cylindrical iodine-filled tubes, causing experimental SNR to vary from 2.2 to 0.8 times the predictions from low to high values of SNR. Iodine contrast in the subtracted images was found to be mainly defined by the spectra, independent of exposure, and linearly dependent on the iodine mass thickness. The highest contrast was obtained with the combined dual-energy temporal subtraction with Rh34-Rh45H, its value was 7% larger than the highest value measured with Mo25-Rh40. As expected, temporal modalities (single and dual energy, any spectral choice) led to higher contrast

  16. Digital Subtraction Of Radiographs As An Aid For Detecting Pathologic Changes In Periodontal Bone

    NASA Astrophysics Data System (ADS)

    Webber, Richard L.; Ruttimann, Urs E.

    1982-11-01

    Serial periapical dental radiographs are produced using a constant exposure geometry made possible by a simple occlusal template. Selected radiograph pairs are placed in register with the aid of a micromanipulator and a closed-circuit video system. The same video system, interfaced with an A to D converter, is used to store the respective radiographs as 6 bit images in a frame buffer. A computer is then used to subtract the two images. Gamma correction is accomplished with special software to assure that any non-linear effects attributable to contrast differences between radiographs are minimized. Blurring of the difference image, in an area known to be unchanged, provides a means for thresholding out differences attributable to registration artifacts. Preliminary data on both patients and radiographic phantoms demonstrate that diagnostic accuracy from subtracted images is markedly improved when compared to that obtainable from the undigitized control radiographs displayed conventionally.

  17. Chrom: A C program to evaluate the application of the dark object subtraction technique to digital remote-sensing data

    NASA Astrophysics Data System (ADS)

    Campbell, James B.; Ran, Limei

    1993-11-01

    This program, written in Turbo-C, version 2.0, permits the user to enter data from several earth-resource satellite systems, determine corresponding radiances (using published calibration data) and plot chromaticity coordinates on the usual chromaticity diagram. If the user enters the digital numbers (DNs) in three spectral bands for a dark object selected by the user, the program will use these values to perform the dark object subtraction technique for adjusting for the effects of atmospheric scattering, and plot chromaticity coordinates for both original and corrected values. The program allows the user to enter values from the screen, or from a file that records several sets of DNs. Calibration data also can be entered by the user, to allow for use with revised calibration data, or with systems other than those discussed here. The program also allows the user to apply a modified dark object subtraction technique as proposed by P. S. Chavez in 1988. The user selects a scattering model, based upon an assessment of prevailing atmospheric conditions, and selection of one of the visible bands to be used as a base for calculation of corrections to be applied to other bands. The chromaticity technique permits the user to examine the spectra of features before and after application of the correction, to assess if the adjustment is satisfactory.

  18. ANGY: A Rule-Based Expert System for Automatic Segmentation of Coronary Vessels From Digital Subtracted Angiograms.

    PubMed

    Stansfield, S A

    1986-02-01

    This paper details the design and implementation of ANGY, a rule-based expert system in the domain of medical image processing. Given a subtracted digital angiogram of the chest, ANGY identifies and isolates the coronary vessels, while ignoring any nonvessel structures which may have arisen from noise, variations in background contrast, imperfect subtraction, and irrelevent anatomical detail. The overall system is modularized into three stages: the preprocessing stage and the two stages embodied in the expert itself. In the preprocessing stage, low-level image processing routines written in C are used to create a segmented representation of the input image. These routines are applied sequentially. The expert system is rule-based and is written in OPS5 and LISP. It is separated into two stages: The low-level image processing stage embodies a domain-independent knowledge of segmentation, grouping, and shape analysis. Working with both edges and regions, it determines such relations as parallel and adjacent and attempts to refine the segmentation begun by the preprocessing. The high-level medical stage embodies a domain-dependent knowledge of cardiac anatomy and physiology. Applying this knowledge to the objects and relations determined in the preceding two stages, it identifies those objects which are vessels and eliminates all others. PMID:21869337

  19. Hemodynamic responses of the equine digit to intravenous and digital arterial infusion of dopamine.

    PubMed

    Hunt, R J; Moore, J N; Allen, D

    1990-04-01

    In 6 adult horses anesthetized with pentobarbital, the hemodynamic responses of the equine digit to infusion of dopamine were evaluated by use of an isolated extra corporeal pump perfused digital preparation. Digital blood flow was maintained at a constant rate that was independent of systemic hemodynamic changes. Three sequential experiments were performed on each horse. In the first experiment (n = 6), dopamine was infused IV at rates of 1.0, 2.5, and 5.0 micrograms/kg/min. For the second experiment (n = 5), dopamine (400 micrograms/ml) was infused into the digital artery at the rates of 0.07, 0.7, and 1.2 ml/min. The third experiment (n = 5) consisted of a 5-minute intra-arterial infusion of phentolamine followed by the intra-arterial infusion of dopamine while continuing the infusion of phentolamine. Digital venous, arterial, and capillary pressures, total digital vascular resistance, and precapillary to postcapillary resistance ratios were determined in each experiment. Systemic infusion of dopamine did not induce changes in the hemodynamics of the digital vasculature. Digital arterial infusion of dopamine alone resulted in a dose-dependent increase in arterial pressure, total digital vascular resistance, and an increase in the precapillary to postcapillary resistance ratio. Phentolamine attenuated the vasoconstrictive response elicited by intra-arterial infusion of dopamine. PMID:2327616

  20. Advanced digital subtraction angiography and MR fusion imaging protocol applied to accurate placement of flow diverter device.

    PubMed

    Faragò, Giuseppe; Caldiera, Valentina; Tempra, Giovanni; Ciceri, Elisa

    2016-02-01

    In recent years there has been a progressive increase in interventional neuroradiology procedures, partially due to improvements in devices, but also to the simultaneous development of technologies and radiological images. Cone beam CT (Dyna-CT; Siemens) is a method recently used to obtain pseudo CT images from digital subtraction angiography (DSA) with a flat panel detector. Using dedicated software, it is then possible to merge Dyna-CT images with images from a different source. We report here the usefulness of advanced DSA techniques (Syngo-Dyna CT, three-dimensional DSA iPilot) for the treatment of an intracranial aneurysm with a flow diverter device. Merging MR and Dyna-CT images at the end of the procedure proved to be a simple and rapid additional method of verifying the success of the intervention. PMID:25589548

  1. Integration of temporal subtraction and nodule detection system for digital chest radiographs into picture archiving and communication system (PACS): four-year experience.

    PubMed

    Sakai, Shuji; Yabuuchi, Hidetake; Matsuo, Yoshio; Okafuji, Takashi; Kamitani, Takeshi; Honda, Hiroshi; Yamamoto, Keiji; Fujiwara, Keiichi; Sugiyama, Naoki; Doi, Kunio

    2008-03-01

    Since May 2002, temporal subtraction and nodule detection systems for digital chest radiographs have been integrated into our hospital's picture archiving and communication systems (PACS). Image data of digital chest radiographs were stored in PACS with the digital image and communication in medicine (DICOM) protocol. Temporal subtraction and nodule detection images were produced automatically in an exclusive server and delivered with current and previous images to the work stations. The problems that we faced and the solutions that we arrived at were analyzed. We encountered four major problems. The first problem, as a result of the storage of the original images' data with the upside-down, reverse, or lying-down positioning on portable chest radiographs, was solved by postponing the original data storage for 30 min. The second problem, the variable matrix sizes of chest radiographs obtained with flat-panel detectors (FPDs), was solved by improving the computer algorithm to produce consistent temporal subtraction images. The third problem, the production of temporal subtraction images of low quality, could not be solved fundamentally when the original images were obtained with different modalities. The fourth problem, an excessive false-positive rate on the nodule detection system, was solved by adjusting this system to chest radiographs obtained in our hospital. Integration of the temporal subtraction and nodule detection system into our hospital's PACS was customized successfully; this experience may be helpful to other hospitals. PMID:17333415

  2. Suppression of high-density artifacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    NASA Astrophysics Data System (ADS)

    Baissalov, Roustem; Sandison, George A.; Donnelly, Bryan J.; Saliken, John C.; Muldrew, Ken; Rewcastle, John C.

    2000-06-01

    Image guidance of cryotherapy is usually performed using ultrasound or x-ray CT. Despite the ability of CT to display the full 3D structure of the iceball, including frozen and unfrozen regions, the quality of the images is compromised by the presence of high density streak artifacts. To suppress these artifacts we applied Temporal Digital Subtraction (TDS). This TDS method has the added advantage of improving the gray scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high density artifacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced content of the artifacts. This TDS can be used in x-ray CT assisted cryotherapy to significantly suppress or eliminate high density x-ray CT streak artifacts by digitally processing x-ray CT images. Applying TDS in cryotherapy will facilitate estimation of the amount and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent.

  3. A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: A simulation study

    NASA Astrophysics Data System (ADS)

    Choi, Sunghoon; Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung

    2014-06-01

    Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05-1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

  4. Particle tracking by full-field complex wavefront subtraction in digital holography microscopy.

    PubMed

    Miccio, L; Memmolo, P; Merola, F; Fusco, S; Embrione, V; Paciello, A; Ventre, M; Netti, P A; Ferraro, P

    2014-03-21

    The 3D tracking of micro-objects, based on digital holography, is proposed through the analysis of the complex wavefront of the light scattered by the micro-samples. Exploiting the advantages of the off-axis full-field holographic interferometry, the tracking of multiple objects is achieved by a direct wavefront analysis at the focal plane overcoming the limitation of the conventional back focal plane interferometry in which only one object at a time can be tracked. Furthermore, the method proposed and demonstrated here is a step forward with respect to other holographic tracking tools. The approach is tested in two experiments, the first investigates the Brownian motion of particles trapped by holographic optical tweezers, while the second relates to the cell motility in a 3D collagen matrix, thus showing its usefulness for lab-on-chip systems in typical bioassay testing. PMID:24463986

  5. The biologic stability of alumina-zirconia implant abutments after 1 year of clinical service: a digital subtraction radiographic evaluation.

    PubMed

    Bae, Kyu-Hyun; Han, Jung-Suk; Seol, Yang-Jo; Butz, Frank; Caton, Jack; Rhyu, In-Chul

    2008-04-01

    The purpose of the present clinical study was to evaluate the biologic stability of alumina-zirconia implant abutments by histologic and radiographic examination. Nineteen partially edentulous patients were treated with 37 external-hexagon implants. After a healing period of 3 to 6 months, alumina-zirconia abutments were connected and restored with cemented single crowns or short-span fixed partial dentures. Periapical radiographs were taken at the time of prosthesis delivery and after 3, 6, and 12 months of follow-up. Crestal alveolar bone level changes were assessed by digital subtraction of consecutive images, and 1-way analysis of variance was used for statistical analysis. No implant, abutment, or restoration failed during the observation period. Bone level changes were statistically insignificant and histologic examination revealed no signs of inflammation. Stable and healthy soft and hard tissue conditions may be expected around alumina-zirconia abutments after 1 year of clinical service. However, long-term data are needed to confirm the present results. PMID:18546809

  6. Initial testing of a 3D printed perfusion phantom using digital subtraction angiography

    PubMed Central

    Khobragade, Parag; Ying, Leslie; Snyder, Kenneth; Wack, David; Bednarek, Daniel R.; Rudin, Stephen; Ionita, Ciprian N.

    2015-01-01

    Perfusion imaging is the most applied modality for the assessment of acute stroke. Parameters such as Cerebral Blood Flow (CBF), Cerebral Blood volume (CBV) and Mean Transit Time (MTT) are used to distinguish the tissue infarct core and ischemic penumbra. Due to lack of standardization these parameters vary significantly between vendors and software even when provided with the same data set. There is a critical need to standardize the systems and make them more reliable. We have designed a uniform phantom to test and verify the perfusion systems. We implemented a flow loop with different flow rates (250, 300, 350 ml/min) and injected the same amount of contrast. The images of the phantom were acquired using a Digital Angiographic system. Since this phantom is uniform, projection images obtained using DSA is sufficient for initial validation. To validate the phantom we measured the contrast concentration at three regions of interest (arterial input, venous output, perfused area) and derived time density curves (TDC). We then calculated the maximum slope, area under the TDCs and flow. The maximum slope calculations were linearly increasing with increase in flow rate, the area under the curve decreases with increase in flow rate. There was 25% error between the calculated flow and measured flow. The derived TDCs were clinically relevant and the calculated flow, maximum slope and areas under the curve were sensitive to the measured flow. We have created a systematic way to calibrate existing perfusion systems and assess their reliability. PMID:26633914

  7. Use of cone-beam tomography and digital subtraction radiography for diagnosis and evaluation of traumatized teeth treated with endodontic surgery and MTA. A case report.

    PubMed

    de Carvalho, Fabíola Bastos; Gonçalves, Paloma Souza; Lima, Regina Karla de Pontes; Guerreiro-Tanomaru, Juliane Maria; Rasquin, Luis Cardoso; Tanomaru-Filho, Mário

    2013-10-01

    The aim of this paper was to report the diagnosis and evaluation of periradicular bone repair by using computed tomography and digital subtraction radiography in an endodontic surgery case treated with mineral trioxide aggregate (MTA). The patient had local swelling and fistula 7 years after trauma in the upper jaw. Periapical lesion on tooth #12 and root resorption of tooth #11 were detected radiographically. Endodontic therapy and placement of intracanal medication were carried out. After 3 months, with no improvement in the clinical signs and symptoms, computed tomography was performed, showing extensive apical bone resorption on tooth #12 and dental resorption promoting communication of the root canal with the periodontium of tooth #11. The patient was referred to endodontic surgery. After surgery and postoperative periods of 15, 30, 60, 90, and 120 days, standardized radiographs were taken, digitized, and subjected to digital subtraction of the images using Adobe Photoshop CS software. Four years later, a cone-beam computed tomography was performed, showing bone repair and absence of root resorption at tooth #11. In this clinical case, digital subtraction radiography was effective for early detection of new bone formation and evolution of repair. PMID:22111874

  8. A retrospective study of digital subtraction technique to detect sclerotic changes in alveolar bone on intraoral radiographs of bisphosphonate-treated patients

    PubMed Central

    Zaman, M U; Nakamoto, T; Tanimoto, K

    2013-01-01

    Objectives: Several reports have suggested that sclerotic changes in cancellous bone of the jaw and thickening of the lamina dura are characteristic radiographic changes of an early silent stage of bisphosphonate (BP)-related osteonecrosis of the jaw. No quantitative evaluation has been reported to support this hypothesis. Emago® software (Oral Diagnostic Systems, Amsterdam, Netherlands) can perform digital subtraction on intraoral radiographs even if they were obtained by non-standardized radiography, provided the dimensional error is within a certain limit. The purpose of this study was to evaluate whether sclerotic changes of alveolar bone or thickening of lamina dura in patients using BP can be detected using the subtraction function of Emago. Methods: The authors selected 46 pairs of intraoral radiographs of the mandibular molar area in dental patients. All radiographs were obtained at intervals of 6 months or more. Among the 46 pairs, 7 pairs were from patients who were being treated with BP (study subjects), and 39 pairs were from patients who had not been using BP (controls). All pairs of radiographs underwent digital subtraction by Emago. The number of pixels of the sclerotic areas was counted and compared between subjects and controls. Results: The sclerotic changes were significantly distinguishable in two of the seven subjects (28.6%) using BP. Conclusions: Digital subtraction function of Emago was able to detect sclerotic changes in alveolar bone. Therefore, it is suggested that the subtraction function of Emago is a useful tool for quantitatively detecting sclerotic changes that are observed at an early, silent stage of BP-related osteonecrosis of the jaw. PMID:24170801

  9. Mask free intravenous 3D digital subtraction angiography (IV 3D-DSA) from a single C-arm acquisition

    NASA Astrophysics Data System (ADS)

    Li, Yinsheng; Niu, Kai; Yang, Pengfei; Aagaard-Kienitz, Beveley; Niemann, David B.; Ahmed, Azam S.; Strother, Charles; Chen, Guang-Hong

    2016-03-01

    Currently, clinical acquisition of IV 3D-DSA requires two separate scans: one mask scan without contrast medium and a filled scan with contrast injection. Having two separate scans adds radiation dose to the patient and increases the likelihood of suffering inadvertent patient motion induced mis-registration and the associated mis-registraion artifacts in IV 3D-DSA images. In this paper, a new technique, SMART-RECON is introduced to generate IV 3D-DSA images from a single Cone Beam CT (CBCT) acquisition to eliminate the mask scan. Potential benefits of eliminating mask scan would be: (1) both radiation dose and scan time can be reduced by a factor of 2; (2) intra-sweep motion can be eliminated; (3) inter-sweep motion can be mitigated. Numerical simulations were used to validate the algorithm in terms of contrast recoverability and the ability to mitigate limited view artifacts.

  10. An automatic fuzzy-based multi-temporal brain digital subtraction angiography image fusion algorithm using curvelet transform and content selection strategy.

    PubMed

    Momeni, Saba; Pourghassem, Hossein

    2014-08-01

    Recently image fusion has prominent role in medical image processing and is useful to diagnose and treat many diseases. Digital subtraction angiography is one of the most applicable imaging to diagnose brain vascular diseases and radiosurgery of brain. This paper proposes an automatic fuzzy-based multi-temporal fusion algorithm for 2-D digital subtraction angiography images. In this algorithm, for blood vessel map extraction, the valuable frames of brain angiography video are automatically determined to form the digital subtraction angiography images based on a novel definition of vessel dispersion generated by injected contrast material. Our proposed fusion scheme contains different fusion methods for high and low frequency contents based on the coefficient characteristic of wrapping second generation of curvelet transform and a novel content selection strategy. Our proposed content selection strategy is defined based on sample correlation of the curvelet transform coefficients. In our proposed fuzzy-based fusion scheme, the selection of curvelet coefficients are optimized by applying weighted averaging and maximum selection rules for the high frequency coefficients. For low frequency coefficients, the maximum selection rule based on local energy criterion is applied to better visual perception. Our proposed fusion algorithm is evaluated on a perfect brain angiography image dataset consisting of one hundred 2-D internal carotid rotational angiography videos. The obtained results demonstrate the effectiveness and efficiency of our proposed fusion algorithm in comparison with common and basic fusion algorithms. PMID:24957394

  11. Effect of injection technique on temporal parametric imaging derived from digital subtraction angiography in patient specific phantoms

    NASA Astrophysics Data System (ADS)

    Ionita, Ciprian N.; Garcia, Victor L.; Bednarek, Daniel R.; Snyder, Kenneth V.; Siddiqui, Adnan H.; Levy, Elad I.; Rudin, Stephen

    2014-03-01

    Parametric imaging maps (PIM's) derived from digital subtraction angiography (DSA) for the cerebral arterial flow assessment in clinical settings have been proposed, but experiments have yet to determine the reliability of such studies. For this study, we have observed the effects of different injection techniques on PIM's. A flow circuit set to physiologic conditions was created using an internal carotid artery phantom. PIM's were derived for two catheter positions, two different contrast bolus injection volumes (5ml and 10 ml), and four injection rates (5, 10, 15 and 20 ml/s). Using a gamma variate fitting approach, we derived PIM's for mean-transit-time (MTT), time-to-peak (TTP) and bolus-arrivaltime (BAT). For the same injection rates, a larger bolus resulted in an increased MTT and TTP, while a faster injection rate resulted in a shorter MTT, TTP, and BAT. In addition, the position of the catheter tip within the vasculature directly affected the PIM. The experiment showed that the PIM is strongly correlated with the injection conditions, and, therefore, they have to be interpreted with caution. PIM images must be taken from the same patient to be able to be meaningfully compared. These comparisons can include pre- and post-treatment images taken immediately before and after an interventional procedure or simultaneous arterial flow comparisons through the left and right cerebral hemispheres. Due to the strong correlation between PIM and injection conditions, this study indicates that this assessment method should be used only to compare flow changes before and after treatment within the same patient using the same injection conditions.

  12. Optical Image Subtraction

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang; Chao, Tien-Hsin

    1988-01-01

    Report reviews optical image subtraction techniques developed during years 1975 through 1985. Useful in such disciplines as studies of earth resources, meteorology, automatic surveillance, pattern recognition, studies of urban growth, and compression of bandwidth in communication systems. Describes following real-time techniques: source encoding, polarization modulation, pseudocolor image-difference detection, holographic-shear-lens technique, and nonlinear electro-optics. Reported non-real-time image-subtraction techniques are following, all of which involve intensity subtraction: speckle-diffuser encoding, speckle-pattern encoding, halftone-screen encoding,and polarization-shifted carrier encoding. Offers an attractive alternative to digital electronic image subtraction, is faster and treats all parts of images simultaneously.

  13. Identification of Students' Intuitive Mental Computational Strategies for 1, 2 and 3 Digits Addition and Subtraction: Pedagogical and Curricular Implications

    ERIC Educational Resources Information Center

    Ghazali, Munirah; Alias, Rohana; Ariffin, Noor Asrul Anuar; Ayub, Ayminsyadora

    2010-01-01

    This paper reports on a study to examine mental computation strategies used by Year 1, Year 2, and Year 3 students to solve addition and subtraction problems. The participants in this study were twenty five 7 to 9 year-old students identified as excellent, good and satisfactory in their mathematics performance from a school in Penang, Malaysia.…

  14. Using digital subtraction in computer simulated images as a tool to aid the visual detection of masked lesions in dense breasts

    NASA Astrophysics Data System (ADS)

    Schiabel, Homero; Guimarães, Luciana T.; Sousa, Maria A. Z.

    2015-03-01

    This work proposes a simulation model involving subtraction of digital mammography images obtained at different X-ray beam levels of energy to aid the detection of breast malignant lesions. Absorption coefficients behavior of 3 main structures of clinical interest - adipose tissue, fiber glandular tissue and the typical carcinoma - as a function of the beam energy from a Mo X-ray tube was the basis to develop a computer simulation of the possible acquired images. The simulation has considered a typical compressed breast with 4.5cm in thickness, and variations of the carcinoma and glandular tissues thicknesses - 0.4 up to 2.0cm and 4.1 to 2.5cm, respectively - were evaluated as a function of the photons mean energy - 14 up to 25 keV, in the typical mammography energy range. Results have shown that: (a) if the carcinoma thickness is over 0.4cm, its detection may be feasible even masked by fiber tissue with exposures in the range of 19 to 25 keV; (b) for masked carcinoma with thickness in the range of 0.4-2.0cm, the proposed procedure can enhance it in the image resulting from the digital subtraction between images obtained at 14 and at 22 keV. Therefore such results indicate that this simulation procedure can be a useful tool in aiding the identification of possible missed malignant lesions which could not be detected in the typical exam, mainly considering dense breasts.

  15. A novel approach to background subtraction in contrast-enhanced dual-energy digital mammography with commercially available mammography devices: Polychromaticity correction

    SciTech Connect

    Contillo, Adriano Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo

    2015-11-15

    Purpose: Contrast-enhanced digital mammography is an image subtraction technique that is able to improve the detectability of lesions in dense breasts. One of the main sources of error, when the technique is performed by means of commercial mammography devices, is represented by the intrinsic polychromaticity of the x-ray beams. The aim of the work is to propose an iterative procedure, which only assumes the knowledge of a small set of universal quantities, to take into account the polychromaticity and correct the subtraction results accordingly. Methods: In order to verify the procedure, it has been applied to an analytical simulation of a target containing a contrast medium and to actual radiographs of a breast phantom containing cavities filled with a solution of the same medium. Results: The reconstructed densities of contrast medium were compared, showing very good agreement between the theoretical predictions and the experimental results already after the first iteration. Furthermore, the convergence of the iterative procedure was studied, showing that only a small number of iterations is necessary to reach limiting values. Conclusions: The proposed procedure represents an efficient solution to the polychromaticity issue, qualifying therefore as a viable alternative to inverse-map functions.

  16. Tests of variable-band multilayers designed for investigating optimal signal-to-noise vs artifact signal ratios in Dual-Energy Digital Subtraction Angiography (DDSA) imaging systems

    SciTech Connect

    Boyers, D.; Ho, A.; Li, Q.; Piestrup, M.; Rice, M.; Tatchyn, R.

    1993-08-01

    In recent work, various design techniques were applied to investigate the feasibility of controlling the bandwidth and bandshape profiles of tungsten/boron-carbon (W/B{sub 4}C) and tungsten/silicon (W/Si) multilayers for optimizing their performance in synchrotron radiation based angiographical imaging systems at 33 keV. Varied parameters included alternative spacing geometries, material thickness ratios, and numbers of layer pairs. Planar optics with nominal design reflectivities of 30%--94% and bandwidths ranging from 0.6%--10% were designed at the Stanford Radiation Laboratory, fabricated by the Ovonic Synthetic Materials Company, and characterized on Beam Line 4-3 at the Stanford Synchrotron Radiation Laboratory, in this paper we report selected results of these tests and review the possible use of the multilayers for determining optimal signal to noise vs. artifact signal ratios in practical Dual-Energy Digital Subtraction Angiography systems.

  17. Incidence of different causes of benign obstruction of the salivary glands: retrospective analysis of 493 cases using fluoroscopy and digital subtraction sialography.

    PubMed

    Lee, L I T; Pawar, R R; Whitley, S; Makdissi, J

    2015-01-01

    To identify the incidence of different causes of benign obstruction of the salivary glands, we retrospectively analysed 788 anonymised sialography reports of 719 patients referred to the department of dental and maxillofacial radiology between 2006 and 2012. Reports that showed evidence of benign obstruction were included (n=493). Salivary stones were identified in 151 (31%), ductal strictures in 115 (23%), and mucus plugs in 295 (60%). In 67 cases (14%) there was evidence of 2 or 3 causes of obstruction. As previously reported, mucous plugs were the most common finding, possibly because of the use of fluoroscopy or digital subtraction sialography, or both. These methods enable images to be captured during the initial filling of the main duct and are likely to prevent mucus plugs from being obscured by the contrast medium, which is the case in conventional sialography when a single image is produced after the contrast has been injected. PMID:25445390

  18. Real-time out-of-plane artifact subtraction tomosynthesis imaging using prior CT for scanning beam digital x-ray system

    SciTech Connect

    Wu, Meng; Fahrig, Rebecca

    2014-11-01

    Purpose: The scanning beam digital x-ray system (SBDX) is an inverse geometry fluoroscopic system with high dose efficiency and the ability to perform continuous real-time tomosynthesis in multiple planes. This system could be used for image guidance during lung nodule biopsy. However, the reconstructed images suffer from strong out-of-plane artifact due to the small tomographic angle of the system. Methods: The authors propose an out-of-plane artifact subtraction tomosynthesis (OPAST) algorithm that utilizes a prior CT volume to augment the run-time image processing. A blur-and-add (BAA) analytical model, derived from the project-to-backproject physical model, permits the generation of tomosynthesis images that are a good approximation to the shift-and-add (SAA) reconstructed image. A computationally practical algorithm is proposed to simulate images and out-of-plane artifacts from patient-specific prior CT volumes using the BAA model. A 3D image registration algorithm to align the simulated and reconstructed images is described. The accuracy of the BAA analytical model and the OPAST algorithm was evaluated using three lung cancer patients’ CT data. The OPAST and image registration algorithms were also tested with added nonrigid respiratory motions. Results: Image similarity measurements, including the correlation coefficient, mean squared error, and structural similarity index, indicated that the BAA model is very accurate in simulating the SAA images from the prior CT for the SBDX system. The shift-variant effect of the BAA model can be ignored when the shifts between SBDX images and CT volumes are within ±10 mm in the x and y directions. The nodule visibility and depth resolution are improved by subtracting simulated artifacts from the reconstructions. The image registration and OPAST are robust in the presence of added respiratory motions. The dominant artifacts in the subtraction images are caused by the mismatches between the real object and the prior CT

  19. Real-time out-of-plane artifact subtraction tomosynthesis imaging using prior CT for scanning beam digital x-ray system

    PubMed Central

    Wu, Meng; Fahrig, Rebecca

    2014-01-01

    Purpose: The scanning beam digital x-ray system (SBDX) is an inverse geometry fluoroscopic system with high dose efficiency and the ability to perform continuous real-time tomosynthesis in multiple planes. This system could be used for image guidance during lung nodule biopsy. However, the reconstructed images suffer from strong out-of-plane artifact due to the small tomographic angle of the system. Methods: The authors propose an out-of-plane artifact subtraction tomosynthesis (OPAST) algorithm that utilizes a prior CT volume to augment the run-time image processing. A blur-and-add (BAA) analytical model, derived from the project-to-backproject physical model, permits the generation of tomosynthesis images that are a good approximation to the shift-and-add (SAA) reconstructed image. A computationally practical algorithm is proposed to simulate images and out-of-plane artifacts from patient-specific prior CT volumes using the BAA model. A 3D image registration algorithm to align the simulated and reconstructed images is described. The accuracy of the BAA analytical model and the OPAST algorithm was evaluated using three lung cancer patients’ CT data. The OPAST and image registration algorithms were also tested with added nonrigid respiratory motions. Results: Image similarity measurements, including the correlation coefficient, mean squared error, and structural similarity index, indicated that the BAA model is very accurate in simulating the SAA images from the prior CT for the SBDX system. The shift-variant effect of the BAA model can be ignored when the shifts between SBDX images and CT volumes are within ±10 mm in the x and y directions. The nodule visibility and depth resolution are improved by subtracting simulated artifacts from the reconstructions. The image registration and OPAST are robust in the presence of added respiratory motions. The dominant artifacts in the subtraction images are caused by the mismatches between the real object and the prior CT

  20. Use of Computed Tomography – Digital Subtraction Angiography in differentiating pulmonary thrombosis and pulmonary artery dissection in a large pulmonary artery aneurysm

    PubMed Central

    Rashid, Hashrul N.Z.; Lim, Andy K.; Lau, Kenneth K.

    2016-01-01

    70 year-old female with chronic obstructive pulmonary disease (COPD) presented with typical symptoms of an exacerbation of COPD. Management of COPD resolved her wheezing, but ongoing hypoxia and retrospective history of atypical chest pain prompted exclusion of a pulmonary embolus. A CT Pulmonary Angiogram (CTPA) with standard 64-slice CT revealed an extensive non-occlusive defect in a grossly dilated right pulmonary artery. Presence of circumferential cuff of soft tissue within sub-segmental pulmonary artery branch raised the possibility of pulmonary artery dissection (PAD). Exclusion of PAD was important as it precluded full anticoagulation. A dynamic CT-digital subtraction angiography (CT-DSA) with the 320-slice multidetector CT (Aquilion-one Vision, Toshiba) did not reveal any intimal flap or contrast extension into the pulmonary arterial wall, suggesting it is unlikely to be PAD. The patient was started on full anticoagulation and reported improvement of symptoms with reduction in pulmonary thrombus burden on repeat CTPA at 4 weeks. To our knowledge, this is the first reported use of dynamic CT-DSA in ruling out PAD. PMID:27144113

  1. Use of Computed Tomography - Digital Subtraction Angiography in differentiating pulmonary thrombosis and pulmonary artery dissection in a large pulmonary artery aneurysm.

    PubMed

    Rashid, Hashrul N Z; Lim, Andy K; Lau, Kenneth K

    2016-01-01

    70 year-old female with chronic obstructive pulmonary disease (COPD) presented with typical symptoms of an exacerbation of COPD. Management of COPD resolved her wheezing, but ongoing hypoxia and retrospective history of atypical chest pain prompted exclusion of a pulmonary embolus. A CT Pulmonary Angiogram (CTPA) with standard 64-slice CT revealed an extensive non-occlusive defect in a grossly dilated right pulmonary artery. Presence of circumferential cuff of soft tissue within sub-segmental pulmonary artery branch raised the possibility of pulmonary artery dissection (PAD). Exclusion of PAD was important as it precluded full anticoagulation. A dynamic CT-digital subtraction angiography (CT-DSA) with the 320-slice multidetector CT (Aquilion-one Vision, Toshiba) did not reveal any intimal flap or contrast extension into the pulmonary arterial wall, suggesting it is unlikely to be PAD. The patient was started on full anticoagulation and reported improvement of symptoms with reduction in pulmonary thrombus burden on repeat CTPA at 4 weeks. To our knowledge, this is the first reported use of dynamic CT-DSA in ruling out PAD. PMID:27144113

  2. Flow modification in canine intracranial aneurysm model by an asymmetric stent: studies using digital subtraction angiography (DSA) and image-based computational fluid dynamics (CFD) analyses

    PubMed Central

    Hoi, Yiemeng; Ionita, Ciprian N.; Tranquebar, Rekha V.; Hoffmann, Kenneth R.; Woodward, Scott, H.; Taulbee, Dale B.; Meng, Hui; Rudin, Stephen

    2011-01-01

    An asymmetric stent with low porosity patch across the intracranial aneurysm neck and high porosity elsewhere is designed to modify the flow to result in thrombogenesis and occlusion of the aneurysm and yet to reduce the possibility of also occluding adjacent perforator vessels. The purposes of this study are to evaluate the flow field induced by an asymmetric stent using both numerical and digital subtraction angiography (DSA) methods and to quantify the flow dynamics of an asymmetric stent in an in vivo aneurysm model. We created a vein-pouch aneurysm model on the canine carotid artery. An asymmetric stent was implanted at the aneurysm, with 25% porosity across the aneurysm neck and 80% porosity elsewhere. The aneurysm geometry, before and after stent implantation, was acquired using cone beam CT and reconstructed for computational fluid dynamics (CFD) analysis. Both steady-state and pulsatile flow conditions using the measured waveforms from the aneurysm model were studied. To reduce computational costs, we modeled the asymmetric stent effect by specifying a pressure drop over the layer across the aneurysm orifice where the low porosity patch was located. From the CFD results, we found the asymmetric stent reduced the inflow into the aneurysm by 51%, and appeared to create a stasis-like environment which favors thrombus formation. The DSA sequences also showed substantial flow reduction into the aneurysm. Asymmetric stents may be a viable image guided intervention for treating intracranial aneurysms with desired flow modification features. PMID:21666881

  3. NOTE: Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    NASA Astrophysics Data System (ADS)

    Baissalov, R.; Sandison, G. A.; Donnelly, B. J.; Saliken, J. C.; McKinnon, J. G.; Muldrew, K.; Rewcastle, J. C.

    2000-05-01

    Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent.

  4. Contexts for Column Addition and Subtraction

    ERIC Educational Resources Information Center

    Lopez Fernandez, Jorge M.; Velazquez Estrella, Aileen

    2011-01-01

    In this article, the authors discuss their approach to column addition and subtraction algorithms. Adapting an original idea of Paul Cobb and Erna Yackel's from "A Contextual Investigation of Three-Digit Addition and Subtraction" related to packing and unpacking candy in a candy factory, the authors provided an analogous context by designing…

  5. Self-masking subtraction tomosynthesis

    SciTech Connect

    Chakraborty, D.P.; Yester, M.V.; Barnes, G.T.; Lakshminarayanan, A.V.

    1984-01-01

    The authors tested the image quality and dose savings of self-masking subtraction tomosynthesis (SST), which combines digital tomosynthesis with subtraction of a blurred self-mask. High-quality images of the inner ear of a head phantom were obtained at moderate dose savings. Although they were taken with linear motion, they did not exhibit the streaking due to off-fulcrum objects that is characteristic of conventional linear tomography. SST could reduce patient dose by a factor of at least 12 in examinations of the inner ear, and the mechanical aspects can be implemented with moderate modifications of existing instrumentation.

  6. Evaluation of the lower limb vasculature before free fibula flap transfer. A prospective blinded comparison between magnetic resonance angiography and digital subtraction angiography.

    PubMed

    Klein, Steven; Van Lienden, Krijn P; Van't Veer, Marcel; Smit, Jeroen M; Werker, Paul M N

    2013-10-01

    Introduction The aim of this study was to compare magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) in the preoperative assessment of crural arteries and their skin perforators prior to free fibular transfer. Patients and methods Fifteen consecutive patients, scheduled for free vascularized fibular flap transfer, were subjected to DSA as well as MRA of the crural arteries of both legs (n = 30). All DSA and MRA images were assessed randomly, blindly, and independently by two radiologists. Each of the assessors scored the degree of stenosis of various segments on a 5 point scale from 0 (occlusive) to 4 (no stenosis). The Cohen's Kappa coefficient was used to assess the agreement between DSA and MRA scores. In addition, the number of cutaneous perforators were scored and the assessors were asked if they would advise against fibula harvest and transplantation based on the images. Results A Cohen's Kappa of 0.64, indicating "substantial agreement of stenosis severity scores" was found between the two imaging techniques. The sensitivity of MRA to detect a stenosis compared with DSA was 79% (CI 95%:60-91), and a specificity of 98% (CI 95%: 97-99). In 53 out of 60 assessments, advice on suitability for transfer were equal between DSA and MRA. The median number of cutaneous perforators that perfuse the skin overlying the fibula per leg was one for DSA as well as MRA (P = 0.142).Conclusions A substantial agreement in the assessment of stenosis severity was found between DSA and MRA. The results suggest that MRA is a good alternative to DSA in the preoperative planning of free fibula flap transplantation. PMID:24038374

  7. Value of Single-Dose Contrast-Enhanced Magnetic Resonance Angiography Versus Intraarterial Digital Subtraction Angiography in Therapy Indications in Abdominal and Iliac Arteries

    SciTech Connect

    Schaefer, Philipp J. Schaefer, Fritz K. W.; Mueller-Huelsbeck, Stefan; Both, Markus; Heller, Martin; Jahnke, Thomas

    2007-06-15

    The objective of the study was to prove the value of single-dose contrast-enhanced magnetic resonance angiography [three-dimensional (3D) ceMRA] in abdominal and iliac arteries versus the reference standard intra-arterial digital subtraction angiography (i.a.DSA) when indicating a therapy. Patients suspected of having abdominal or iliac artery stenosis were included in this study. A positive vote of the local Ethics Committee was given. After written informed consent was obtained, 37 patients were enrolled, of which 34 were available for image evaluation. Both 3D ceMRA and i.a. DSA were performed for each patient. The dosage for 3D ceMRA was 0.1 mmol/kg body weight in a 1.5-T scanner with a phased-array coil. The parameters of the 3D-FLASH sequence were as follows: TR/TE 4.6/1.8 ms, effective thickness 3.5 mm, matrix 512 x 200, flip angle 30{sup o}, field of view 420 mm, TA 23 s, coronal scan orientation. Totally, 476 vessel segments were evaluated for stenosis degree by two radiologists in a consensus fashion in a blinded read. For each patient, a therapy was proposed, if clinically indicated. Sensitivity, specificity, positive and negative predictive values, and accuracy for stenoses {>=}50% were 68%, 92%, 44%, 97%, and 90%, respectively. In 13/34 patients, a discrepancy was found concerning therapy decisions based on MRA findings versus therapy decisions based on the reference standard DSA. The results showed that the used MRA imaging technique of abdominal and iliac arteries is not competitive to i.a. DSA, with a high rate of misinterpretation of the MRAs resulting in incorrect therapies.

  8. Evaluation of Non-contrast Dynamic MRA in Intracranial Arteriovenous Malformation (AVM): Comparison with time of flight (TOF) and digital subtraction angiography (DSA)

    PubMed Central

    Yu, Songlin; Yan, Lirong; Yao, Yuqiang; Wang, Shuo; Yang, Mingqi; Wang, Bo; Zhuo, Yan; Zhao, Jizong; Wang, Danny J. J.

    2014-01-01

    Purpose Digital subtraction angiography (DSA) remains the gold standard to diagnose intracranial arteriovenous malformations (AVMs) but is invasive. Existing magnetic resonance angiography (MRA) is suboptimal for assessing the hemodynamics of AVMs. The objective of this study was to evaluate the clinical utility of a novel noncontrast four-dimensional (4D) dynamic MRA (dMRA) in the evaluation of intracranial AVMs through comparison with DSA and time-of-flight (TOF) MRA. Materials and methods Nineteen patients (12 women, mean age 26.2±10.7 years) with intracranial AVMs were examined with 4D dMRA, TOF and DSA. Spetzler–Martin grading scale was evaluated using each of the above three methods independently by two raters. Diagnostic confidence scores for three components of AVMs (feeding artery, nidus and draining vein) were also rated. Kendall's coefficient of concordance was calculated to evaluate the reliability between two raters within each modality (dMRA, TOF, TOF plus dMRA). The Wilcoxon signed-rank test was applied to compare the diagnostic confidence scores between each pair of the three modalities Results dMRA was able to detect 16 out of 19 AVMs, and the ratings of AVM size and location matched those of DSA. The diagnostic confidence scores by dMRA were adequate for nidus (3.5/5), moderate for feeding arteries (2.5/5) and poor for draining veins (1.5/5). The hemodynamic information provided by dMRA improved diagnostic confidence scores by TOF MRA. Conclusion As a completely noninvasive method, 4D dMRA offers hemodynamic information with a temporal resolution of 50–100 ms for the evaluation of AVMs and can complement existing methods such as DSA and TOF MRA. PMID:22521994

  9. Diagnostic yield and accuracy of CT angiography, MR angiography, and digital subtraction angiography for detection of macrovascular causes of intracerebral haemorrhage: prospective, multicentre cohort study

    PubMed Central

    Velthuis, Birgitta K; Rinkel, Gabriël J E; Algra, Ale; de Kort, Gérard A P; Witkamp, Theo D; de Ridder, Johanna C M; van Nieuwenhuizen, Koen M; de Leeuw, Frank-Erik; Schonewille, Wouter J; de Kort, Paul L M; Dippel, Diederik W; Raaymakers, Theodora W M; Hofmeijer, Jeannette; Wermer, Marieke J H; Kerkhoff, Henk; Jellema, Korné; Bronner, Irene M; Remmers, Michel J M; Bienfait, Henri Paul; Witjes, Ron J G M; Greving, Jacoba P; Klijn, Catharina J M

    2015-01-01

    Study question What are the diagnostic yield and accuracy of early computed tomography (CT) angiography followed by magnetic resonance imaging/angiography (MRI/MRA) and digital subtraction angiography (DSA) in patients with non-traumatic intracerebral haemorrhage? Methods This prospective diagnostic study enrolled 298 adults (18-70 years) treated in 22 hospitals in the Netherlands over six years. CT angiography was performed within seven days of haemorrhage. If the result was negative, MRI/MRA was performed four to eight weeks later. DSA was performed when the CT angiography or MRI/MRA results were inconclusive or negative. The main outcome was a macrovascular cause, including arteriovenous malformation, aneurysm, dural arteriovenous fistula, and cavernoma. Three blinded neuroradiologists independently evaluated the images for macrovascular causes of haemorrhage. The reference standard was the best available evidence from all findings during one year’s follow-up. Study answer and limitations A macrovascular cause was identified in 69 patients (23%). 291 patients (98%) underwent CT angiography; 214 with a negative result underwent additional MRI/MRA and 97 with a negative result for both CT angiography and MRI/MRA underwent DSA. Early CT angiography detected 51 macrovascular causes (yield 17%, 95% confidence interval 13% to 22%). CT angiography with MRI/MRA identified two additional macrovascular causes (18%, 14% to 23%) and these modalities combined with DSA another 15 (23%, 18% to 28%). This last extensive strategy failed to detect a cavernoma, which was identified on MRI during follow-up (reference strategy). The positive predictive value of CT angiography was 72% (60% to 82%), of additional MRI/MRA was 35% (14% to 62%), and of additional DSA was 100% (75% to 100%). None of the patients experienced complications with CT angiography or MRI/MRA; 0.6% of patients who underwent DSA experienced permanent sequelae. Not all patients with negative CT angiography and

  10. Animal experiments by K-edge subtraction angiography by using SR (abstract)

    NASA Astrophysics Data System (ADS)

    Anno, I.; Akisada, M.; Takeda, T.; Sugishita, Y.; Kakihana, M.; Ohtsuka, S.; Nishimura, K.; Hasegawa, S.; Takenaka, E.; Hyodo, K.; Ando, M.

    1989-07-01

    Ischemic heart disease is one of the most popular and lethal diseases for aged peoples in the world, and is usually diagnosed by transarterial selective coronary arteriography. However, it is rather invasive and somewhat dangerous, so that the selective coronary arteriography is not feasible for prospective screening of coronary occlusive heart disease. Conventional digital subtraction angiography (DSA) is widely known as a relatively noninvasive and useful technique is making a diagnosis of arterial occlusive disease, especially in making the diagnosis of ischemic heart disease. Conventional intravenous subtraction angiography by temporal subtraction, however, has several problems when applying to the moving objects. Digital subtraction method using high-speed switching above and below the K edge could be the ideal approach to this solution. We intend to make a synchrotron radiation digital K-edge subtraction angiography in the above policy, and to apply it to the human coronary ischemic disease on an outpatient basis. The principles and experimental systems have already been described in detail by our coworkers. Our prototype experimental system is situated at the AR (accumulation ring) for TRISTAN project of high energy physics. The available beam size is 70 mm by 120 mm. The electron energy of AR is 6.5 GeV and average beam current is approximately 10 mA. This paper will show the animal experiments of our K-edge subtraction system, and discuss some problems and technical difficulties. Three dogs, weighing approximately 15 kg, were examined to evaluate the ability of our prototype synchrotron radiation DSA unit, that we are now constructing. The dogs were anaesthetized with pentobarbital sodium, intravenously (30 mg/kg). Six french-sized (1.52 mm i.d.) pigtail catheter with multiple side holes were introduced via the right femoral vein into the right atrium by the cutdown technique under conventional x-ray fluoroscopic control. Respiration of the dogs was

  11. Digital radiography: a focus on clinical utility

    SciTech Connect

    Price, R.R.; Rollo, F.D.; Monahan, W.G.; James, A.E. Jr.

    1982-01-01

    This book is interesting and timely in that it covers the new and exciting area of digital radiography. The book begins with chapters on the physics, instrumentation, and terminology of digital radiography. Then cost-benefit ratios, legal implication, and outpatient vs. inpatient studies are discussed. The clinical chapters follow. These are applicable to the head and neck, heart, lungs, kidneys, peripheral arteries, and pediatric population. Discussion then centers on intraarterial digital subtraction, clinical experience at Wisconsin, nonangiography application of digital radiology in children, and analog film-screen subtraction intravenous angiography. The book ends by briefly discussing microwave imaging, nuclear magnetic resonance, emission tomography, real-time and Doppler sonography, analog tomography, and the future photoelectric radiology department.

  12. Contrast-enhanced three-dimensional fast-spoiled gradient magnetic resonance angiography of the renal arteries for potential living renal transplant donors: a comparative study with digital subtraction angiography.

    PubMed

    Al-Saeed, O; Ismail, M; Sheikh, M; Al-Moosawi, M; Al-Khawari, H

    2005-06-01

    Preoperative assessment of the arterial anatomy of prospective renal donors is essential. Various non-invasive techniques are used for such evaluation. We conducted this study using contrast-enhanced 3-D fast-spoiled gradient (CE 3-D FSPGR) magnetic resonance angiography (MRA) on a 1.0 Tesla magnet, for preoperative definition of the renal arteries. Forty-five preoperative living renal donors underwent CE 3-D FSPGR MRA of the renal vessels and the results were compared with conventional digital subtraction angiography (DSA). The renal vascular anatomy, both normal and with variations, was satisfactorily defined in all 45 cases with CE 3-D FSPGR MRA. Fifteen cases showed an accessory or aberrant arterial supply. A small aneurysm was shown in one case. All cases compared well with conventional DSA. Our study revealed that CE 3-D FSPGR MRA on a lower field strength magnet is accurate in defining the renal vascular anatomy and its variations. PMID:15932463

  13. SR high-speed K-edge subtraction angiography in the small animal (abstract)

    NASA Astrophysics Data System (ADS)

    Takeda, T.; Akisada, M.; Nakajima, T.; Anno, I.; Ueda, K.; Umetani, K.; Yamaguchi, C.

    1989-07-01

    To assess the ability of the high-speed K-edge energy subtraction system which was made at beamline 8C of Photon Factory, Tsukuba, we performed an animal experiment. Rabbits were used for the intravenous K-edge subtraction angiography. In this paper, the actual images of the artery obtained by this system, are demonstrated. The high-speed K-edge subtraction system consisted of movable silicon (111) monocrystals, II-ITV, and digital memory system. Image processing was performed by 68000-IP computer. The monochromatic x-ray beam size was 50×60 mm. Photon energy above and below iodine K edge was changed within 16 ms and 32 frames of images were obtained sequentially. The rabbits were anaesthetized by phenobarbital and a 5F catheter was inserted into inferior vena cava via the femoral vein. 1.5 ml/kg of contrast material (Conlaxin H) was injected at the rate of 0.5 ml/kg/s. TV images were obtained 3 s after the starting point of injection. By using this system, the clear K-edge subtracted images were obtained sequentially as a conventional DSA system. The quality of the images were better than that obtained by DSA. The dynamical blood flow was analyzed, and the best arterial image could be selected from the sequential images. The structures of aortic arch, common carotid arteries, right subclavian artery, and internal thoracic artery were obtained at the chest. Both common carotid arteries and vertebral arteries were recorded at the neck. The diameter of about 0.3-0.4 mm artery could be clearly revealed. The high-speed K-edge subtraction system demonstrates the very sharp arterial images clearly and dynamically.

  14. Effect of x-ray energy dispersion in digital subtraction imaging at the iodine K-edge--A Monte Carlo study

    SciTech Connect

    Prino, F.; Ceballos, C.; Cabal, A.; Sarnelli, A.; Gambaccini, M.; Ramello, L.

    2008-01-15

    The effect of the energy dispersion of a quasi-monochromatic x-ray beam on the performance of a dual-energy x-ray imaging system is studied by means of Monte Carlo simulations using MCNPX (Monte Carlo N-Particle eXtended) version 2.6.0. In particular, the case of subtraction imaging at the iodine K-edge, suitable for angiographic imaging application, is investigated. The average energies of the two beams bracketing the iodine K-edge are set to the values of 31.2 and 35.6 keV corresponding to the ones obtained with a compact source based on a conventional x-ray tube and a mosaic crystal monochromator. The energy dispersion of the two beams is varied between 0 and 10 keV of full width at half-maximum (FWHM). The signal and signal-to-noise ratio produced in the simulated images by iodine-filled cavities (simulating patient vessels) drilled in a PMMA phantom are studied as a function of the x-ray energy dispersion. The obtained results show that, for the considered energy separation of 4.4 keV, no dramatic deterioration of the image quality is observed with increasing x-ray energy dispersion up to a FWHM of about 2.35 keV. The case of different beam energies is also investigated by means of fast simulations of the phantom absorption.

  15. Intravenous Therapy.

    ERIC Educational Resources Information Center

    Galliart, Barbara

    Intended for teaching licensed practical nurses, this curriculum guide provides information related to the equipment and skills required for nursing care of patients needing intravenous (IV) therapy. It also explains the roles and responsibilities of the licensed practical nurse with regard to intravenous therapy. Each of the 15 instructional…

  16. Optimal Image Subtraction

    NASA Astrophysics Data System (ADS)

    Gal-Yam, Avishay; Zackay, Barak; Ofek, Eran O.

    2016-01-01

    Transient detection and flux measurement via image subtraction are fundamental to time domain astronomy. Starting from first principles, we develop the optimal linear statistic for transient detection and flux measurement and any other image-difference hypothesis testing. We derive a simple closed-form statistic that: (1) Is mathematically proven to be the optimal subtraction statistic in the limit of background-dominated noise within the family of linear solutions, that contains all previously suggested methods; (2) Does not leave subtraction or deconvolution artifacts, even in the vicinity of bright stars; (3) Is an order of magnitude faster to compute than popular methods; (4) Allowsautomatic transient detection down to the theoretical sensitivity limit by providing a reliable, well-defined detection significance; (5) Is symmetric to the interchange of the new and reference images; (6) Is numerically stable; and (7) Is trivial to implement. We demonstratethat the correct way to prepare a reference image is the proper image co-addition presented in Zackay & Ofek 2015. Finally, we show a proper image subtraction statistic, that, along with its point spread functions, is a sufficient statistic for any decision or measurement on the difference image. This allows accurate filtration of image artifacts such as cosmic rays and hot pixels. We demonstrate this method on simulated data as well as on observations from the Palomar Transient Factory.

  17. Subtraction at NNLO

    NASA Astrophysics Data System (ADS)

    Frixione, Stefano; Grazzini, Massimiliano

    2005-06-01

    We propose a framework for the implementation of a subtraction formalism at NNLO in QCD, based on an observable- and process-independent cancellation of infrared singularities. As a first simple application, we present the calculation of the contribution to the e+e- dijet cross section proportional to CFTR.

  18. Language, visual working memory, and dot subtraction: What counts?

    PubMed

    Briere, Jennifer L; Campbell, Jamie I D

    2016-03-01

    To investigate cognitive factors affecting subtraction of visual objects, we adapted the dot subtraction task developed by Pica, Lemer, Izard, and Dehaene (2004), who used it to investigate calculation by the Mundurukú, an indigene group in Brazil that has a limited number word vocabulary. In the dot subtraction task, briefly displayed arrays of moving dots are used to represent the quantities for subtraction. We tested 40 Canadian university students' dot enumeration, Arabic digit subtraction, visual working memory, and performance on the dot subtraction task with dot display durations of 2, 1.5, 1, and .5 s. In the 2 s condition, error rates were uniformly low, whereas in the .5 s condition, error rates increased sharply as the minuend increased from 4 to 8, as was observed with the Mundurukú. Individual differences in dot subtraction accuracy were predicted by dot enumeration skill with longer dot display durations but were predicted by visual working memory efficiency with shorter durations. Pica et al. (2004) attributed the Mundurukú participants' very poor subtraction to the absence of counting words, but our results show that a shift to reliance on visual working memory is a nonlinguistic factor that comes into play in the dot subtraction task when time to encode the dot arrays is limited. (PsycINFO Database Record PMID:26372056

  19. Liquid-Crystal-Television Image Subtracters

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Liu, Hua-Kuang

    1988-01-01

    Two image-subtraction systems from output images that show differences between input images of two objects. First: differences appear as bright regions in otherwise dark output image. Second: differences and similarities shown by colors. All parts of two images processed simultaneously by optical components only; digital electronic processing of data not required. Concept offers potential for rapid, inexpensive comparison of images in such applications as automatic inspection, medical diagnosis, and robotic vision.

  20. Myocardial ischemia during intravenous DSA in patients with cardiac disease

    SciTech Connect

    Hesselink, J.R.; Hayman, L.A.; Chung, K.J.; McGinnis, B.D.; Davis, K.R.; Taveras, J.M.

    1984-12-01

    A prospective study was performed for 48 patients who had histories of angina and were referred for digital subtraction angiography (DSA). Cardiac disease was graded according to the American Heart Association (AHA) functional classification system. Each patient received 2-5 injections of 40-ml diatrizoate meglumine and diatrizoate sodium at 15 ml per second in the superior vena cava. Of the 28 patients in functional Classes I or II, 11% had angina and 32% had definite ischemic ECG changes after the DSA injections. Of the patients in functional Class III 63% had angina, and 58% had definite ischemic ECG changes after the injections. These observed cardiac effects following bolus injections of hypertonic ionic contrast media indicate that special precautions are necessary when performing intravenous DSA examinations on this group of high risk patients.

  1. Pharmacokinetic-Pharmacodynamic Modeling of Intravenous and Oral Topiramate and Its Effect on the Symbol-Digit Modalities Test in Adult Healthy Volunteers.

    PubMed

    Lim, Chay Ngee; Birnbaum, Angela K; Brundage, Richard C; Leppik, Ilo E; Cloyd, James C; Clark, Annie; Marino, Susan E

    2016-06-01

    A sequential pharmacokinetic-pharmacodynamic (PK-PD) modeling approach was used to quantify the effects of a single dose of topiramate (100 or 200 mg) on working memory, attention, and psychomotor speed as measured by the Symbol-Digit Modalities Test (SDMT). Established on data pooled from 3 randomized, crossover studies in healthy subjects (19-55 years of age), using both oral and a novel stable-labeled intravenous (IV) formulation of topiramate, an inhibitory Emax model was found to characterize the topiramate concentration-SDMT score relationship well. At the EC50 of 2.85 μg/mL, this topiramate plasma concentration value was estimated to be associated with a 25.5% reduction of SDMT score relative to baseline. Age was an important determinant of the baseline SDMT score, with an estimated decrease of 1.13% in baseline SDMT score with every year of age. Moreover, this approach enabled the quantification of the practice effect observed with repeated administration of the neuropsychological test over shorter testing intervals than have previously been reported in the literature. The finding of a significant effect following a single dose of topiramate in the range widely used to treat migraine and epilepsy needs to be evaluated in a broader patient population undergoing chronic treatment, as the narrow range of resultant concentrations limits the generalizability of the findings. PMID:26395889

  2. Intravenous conivaptan.

    PubMed

    Moen, Marit D; Keating, Gillian M

    2008-01-01

    *Conivaptan is an arginine vasopressin V1A and V2 receptor antagonist. The intravenous formulation is approved in the US for use in the treatment of euvolemic and hypervolemic hyponatremia. Conivaptan produces a dose-dependent electrolyte-sparing aquaresis (solute-free water excretion), increasing serum sodium levels. *In a randomized, double-blind, parallel-group, placebo-controlled, multicenter trial in adults with euvolemic or hypervolemic hyponatremia, the area under the serum sodium concentration-time curve over a 4-day treatment duration (primary endpoint) was significantly greater in intravenous conivaptan 40 mg/day recipients than in placebo recipients. *The total time during treatment that patients had serum sodium levels > or = 4 mEq/L above baseline was significantly longer in intravenous conivaptan than placebo recipients. In conivaptan recipients, an increase in serum sodium levels of > or = 4 mEq/L above baseline was achieved approximately 1 day after the first dose of the drug. *In addition, the mean change from baseline in free water clearance and effective water clearance over the first day of treatment was significantly greater with intravenous conivaptan than with placebo. *Given the nature of the treatment, the tolerability profile for intravenous conivaptan was generally acceptable in patients with hyponatremia. The most common adverse events were injection related (e.g. injection-site phlebitis), hypotension, and pyrexia. PMID:18828645

  3. Numerical integration of subtraction terms

    NASA Astrophysics Data System (ADS)

    Seth, Satyajit; Weinzierl, Stefan

    2016-06-01

    Numerical approaches to higher-order calculations often employ subtraction terms, both for the real emission and the virtual corrections. These subtraction terms have to be added back. In this paper we show that at NLO the real subtraction terms, the virtual subtraction terms, the integral representations of the field renormalization constants and—in the case of initial-state partons—the integral representation for the collinear counterterm can be grouped together to give finite integrals, which can be evaluated numerically. This is useful for an extension towards next-to-next-to-leading order.

  4. Digital Subtraction Arteriography: Now And The Future

    NASA Astrophysics Data System (ADS)

    Crummy, Andrew B.

    1982-12-01

    Roentgen discovered x-rays in late 1895 and published his first paper on the subject December 28, 1895. Almost immediately it was recognized that blood and surrounding tissues provided similar x-ray attenuation and that studies of the cardiovascular system would require the use of some intravascular contrast medium. The first arteriogram was reported in January, 1896, by Haschek and Lindenthal who injected the arteries of a cadaver forearm with a medium that was largely calcium carbonate. It was not until 1927 that Moniz of Portugal reported the first successful arteriograms in patients. He studied the intracranial vasculature with iodinated contrast material which was injected by means of a needle placed in a surgically exposed carotid artery. In 1929, Dos Santos and his colleagues performed aortography with the contrast agent injected into the aorta by way of a translumbar approach. The same group also used one of the earliest pressure injections to ensure rapid delivery of the contrast material. These workers were using iodine as the atom which was incorporated into the contrast medium. Iodine has good biological compatibility and shows an abrupt increase in its x-ray attenuation coefficient at 33 kiloelectron volts and in the energy range commonly used in diagnostic x-ray images it is more efficient in producing x-ray shadows than lead. Iodine remains the contrast atom of choice.

  5. Novel embossed radiography system utilizing energy subtraction

    NASA Astrophysics Data System (ADS)

    Osawa, Akihiro; Sato, Eiichi; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Watanabe, Manabu; Nagao, Jiro; Abderyim, Purkhet; Tanaka, Etsuro; Izumisawa, Mitsuru; Ogawa, Akira; Sato, Shigehiro

    2008-08-01

    Digital subtraction is useful for carrying out embossed radiography by shifting an x-ray source, and energy subtraction is an important technique for imaging target region by deleting unnecessary region in vivo. X-ray generator had a 100-μm-focus tube, energy subtraction was performed at tube voltages of 40 and 60 kV, and a 3.0-mm-thick aluminum filter was used to absorb low-photon-energy bremsstrahlung x-rays. Embossed radiography was achieved with cohesion imaging using a flat panel detector (FPD) with pixel sizes of 48×48 μm, and the shifting distance of the x-ray source in horizontal direction and the distance between the x-ray source and the FPD face were 5.0 mm and 1.0 m, respectively. At a tube voltage of 60 kV and a tube current of 0.50 mA, x-ray intensities without filtering and with filtering were 307 and 28.4 μGy/s, respectively, at 1.0 m from the source. In embossed radiography of non-living animals, the spatial resolution measured using a lead test chart was approximately 70 μm, and we observed embossed images of fine bones, soft tissues, and coronary arteries of approximately 100 μm.

  6. Acute ischemic stroke treated with intravenous tissue plasminogen activator in a patient taking dabigatran with radiographic evidence of recanalization.

    PubMed

    Sangha, Navdeep; El Khoury, Ramy; Misra, Vivek; Lopez, George

    2012-11-01

    Dabigatran etexelate is a new oral direct thrombin inhibitor that has been approved by the US Food and Drug Administration to prevent stroke in patients with nonvalvular atrial fibrillation. A 51-year-old man with a history of atrial fibrillation who was taking dabigatran presented with an acute ischemic stroke. The patient had a normal international normalized ratio, activated partial thromboplastin time, and an elevated thrombin time of 26.4 seconds. Recanalization of the middle cerebral artery with intravenous tissue plasminogen activator was apparent on digital subtraction angiography, and there was no evidence of intracerebral hemorrhage on the repeat computed tomographic scan. This is the first report of a patient who was taking dabigatran etexilate and who had an ischemic stroke caused by a middle cerebral artery occlusion, with an elevated thrombin time and radiographic recanalization with intravenous tissue plasminogen activator without evidence of hemorrhagic transformation. PMID:22683118

  7. Enriching Addition and Subtraction Fact Mastery through Games

    ERIC Educational Resources Information Center

    Bay-Williams, Jennifer M.; Kling, Gina

    2014-01-01

    The learning of "basic facts"--single-digit combinations for addition, subtraction, multiplication, and division--has long been a focus of elementary school mathematics. Many people remember completing endless worksheets, timed tests, and flash card drills as they attempted to "master" their basic facts as children. However,…

  8. Subtraction Facts with Pattern Explorations.

    ERIC Educational Resources Information Center

    Beard, Earl M. L.; Polis, A. Richard

    1981-01-01

    The subtraction ideas presented are designed for elementary and junior high school children, yet are felt to be flexible enough to offer some challenge for high school students, particularly in algebra. (MP)

  9. Color Addition and Subtraction Apps

    NASA Astrophysics Data System (ADS)

    Ruiz, Frances; Ruiz, Michael J.

    2015-10-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step in understanding mathematical representations of RGB color. Finally, color addition and subtraction are presented for the X11 colors from web design to illustrate yet another real-life application of color mixing.

  10. "Subtractive" Bilingualism in Northern Belize.

    ERIC Educational Resources Information Center

    Rubinstein, Robert A.

    "Subtractive" bilingualism in Northern Belize is analyzed based on an extension of a model by Wallace Lambert. The impact of English language instruction on Spanish speaking children in Corozal Town, the northernmost urban center in the British colony of Belize, Central America, is described. This description extends an earlier account of…

  11. Color Addition and Subtraction Apps

    ERIC Educational Resources Information Center

    Ruiz, Frances; Ruiz, Michael J.

    2015-01-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…

  12. Sky subtraction with fiber spectrographs

    NASA Astrophysics Data System (ADS)

    Lissandrini, C.; Cristiani, S.; La Franca, F.

    1994-11-01

    The sky-subtraction performance of multifiber spectrographs is discussed, analyzing in detail the case of the OPTOPUS system at the 3.6-m European Space Observatory (ESO) telescope at La Silla. A standard technique, based on flat fields obtained with a uniformly illuminated screen on the dome, provides poor results. A new method has been developed, using the (O I) emission line at 5577 A as a calibrator of the fiber transmittance, taking into account the diffuse light and the influence of each fiber on the adjacent ones, and correcting for the effects of the image distortions on the sky sampling. In this way the accuracy of the sky subtraction improves from 2%-8% to 1.3%-1.6%.

  13. All-optical background subtraction readout method for bimaterial cantilever array sensing.

    PubMed

    Gong, Cheng; Zhao, Yuejin; Dong, Liquan; Yu, Xiaomei; Chen, Ping; Liu, Weiwei

    2015-08-10

    Optical readout method plays a critical role in bimaterial cantilever array sensing system. The common optical readout methods are based on spectral plane filtering. In the paper an all-optical background subtraction readout approach inspired by total reflection and optical lever principle is presented for the bimaterial cantilever array sensing. Comparing with the spectral plane filtering methods the proposed approach eliminates digital subtraction operation by using optical total reflection instead of digital subtraction and avoids spectral filtering operation. An all-optical background subtraction directly-view infrared sensing system was developed to evaluate the approach. The infrared target can be directly acquired by the visible light CCD. The experimental results and analysis show its unique advantages. PMID:26367910

  14. Two-dimensional real-time imaging system for subtraction angiography using an iodine filter

    NASA Astrophysics Data System (ADS)

    Umetani, Keiji; Ueda, Ken; Takeda, Tohoru; Anno, Izumi; Itai, Yuji; Akisada, Masayoshi; Nakajima, Teiichi

    1992-01-01

    A new type of subtraction imaging system was developed using an iodine filter and a single-energy broad bandwidth monochromatized x ray. The x-ray images of coronary arteries made after intravenous injection of a contrast agent are enhanced by an energy-subtraction technique. Filter chopping of the x-ray beam switches energies rapidly, so that a nearly simultaneous pair of filtered and nonfiltered images can be made. By using a high-speed video camera, a pair of two 512 × 512 pixel images can be obtained within 9 ms. Three hundred eighty-four images (raw data) are stored in a 144-Mbyte frame memory. After phantom studies, in vivo subtracted images of coronary arteries in dogs were obtained at a rate of 15 images/s.

  15. Using addition to solve large subtractions in the number domain up to 20.

    PubMed

    Peters, Greet; De Smedt, Bert; Torbeyns, Joke; Ghesquière, Pol; Verschaffel, Lieven

    2010-02-01

    This study examined 25 university students' use of addition to solve large single-digit subtractions by contrasting performance in the standard subtraction format (12-9=.) and in the addition format (9+.=12). In particular, we investigated the effect of the relative size of the subtrahend on performance in both formats. We found a significant interaction between format, the magnitude of the subtrahend (S) compared to the difference (D) (S>D vs. Ssubtraction format; when the subtrahend was smaller than the difference and S and D were far from each other (e.g., 12-3=.), problems were solved faster in the subtraction than in the addition format. However, when the subtrahend and the difference were close to each other (e.g., 13-7=.), there were no significant reaction time differences between both formats. These results suggest that adults do not rely exclusively and routinely on addition to solve large single-digit subtractions, but select either addition-based or subtraction-based strategies depending on the relative size of the subtrahend. PMID:19963199

  16. Intravenous paracetamol (acetaminophen).

    PubMed

    Duggan, Sean T; Scott, Lesley J

    2009-01-01

    Intravenous paracetamol (rINN)/intravenous acetaminophen (USAN) is an analgesic and antipyretic agent, recommended worldwide as a first-line agent for the treatment of pain and fever in adults and children. In double-blind clinical trials, single or multiple doses of intravenous paracetamol 1 g generally provided significantly better analgesic efficacy than placebo treatment (as determined by primary efficacy endpoints) in adult patients who had undergone dental, orthopaedic or gynaecological surgery. Furthermore, where evaluated, intravenous paracetamol 1 g generally showed similar analgesic efficacy to a bioequivalent dose of propacetamol, and a reduced need for opioid rescue medication. In paediatric surgical patients, recommended doses of intravenous paracetamol 15 mg/kg were not significantly different from propacetamol 30 mg/kg for the treatment of pain, and showed equivocal analgesic efficacy compared with intramuscular pethidine 1 mg/kg in several randomized, active comparator-controlled studies. In a randomized, noninferiority study in paediatric patients with an infection-induced fever, intravenous paracetamol 15 mg/kg treatment was shown to be no less effective than propacetamol 30 mg/kg in terms of antipyretic efficacy. Intravenous paracetamol was well tolerated in clinical trials, having a tolerability profile similar to placebo. Additionally, adverse reactions emerging from the use of the intravenous formulation of paracetamol are extremely rare (<1/10 000). [table: see text]. PMID:19192939

  17. Addition and Subtraction, and Algorithms in General

    ERIC Educational Resources Information Center

    Fielker, David

    2007-01-01

    The juxtaposition of articles by Ian Thompson and Ian Sugarman in "MT202" on addition and subtraction respectively engendered some bemused thoughts in this author, who for some years has been sheltered from controversy by retirement. In this article, Fielker shares some thoughts on addition and subtraction raised by Thompson and Sugarman in their…

  18. Tracking of Human Groups Using Subtraction Stereo

    NASA Astrophysics Data System (ADS)

    Hoshikawa, Yuma; Hashimoto, Yuki; Moro, Alessandro; Terabayashi, Kenji; Umeda, Kazunori

    In this paper, we propose a method for tracking groups of people using three-dimensional (3D) feature points obtained with use of the Kanade-Lucas-Tomasi feature tracker (KLT) method and a stereo camera system called “Subtraction stereo”. The tracking system using subtraction stereo, which focuses its stereo matching algorithm to foreground regions obtained by background subtraction, is realized using Kalman filter based tracker. The effectiveness of the proposed method is verified using 3D scenes of people walking, which are difficult to track.

  19. Optimization of background subtraction for image enhancement

    NASA Astrophysics Data System (ADS)

    Venetsky, Larry; Boczar, Ross; Lee-Own, Robert

    2013-05-01

    Analysis of foreground objects in scenery via image processing often involves a background subtraction process. This process aims to improve blob (connected component) content in the image. Quality blob content is often needed for defining regions of interest for object recognition and tracking. Three techniques are examined which optimize the background to be subtracted - genetic algorithm, an analytic solution based on convex optimization, and a related application of the CVX solver toolbox. These techniques are applied to a set of images and the results are compared. Additionally, a possible implementation architecture that uses multiple optimization techniques with subsequent arbitration to produce the best background subtraction is considered.

  20. The research about the quick algorithm of subtracting the DTM

    NASA Astrophysics Data System (ADS)

    Chian, Tao; Li, Yan; Geng, Juan

    2007-06-01

    There is some relationship between the Digital Surface Model (DSM) and the Digital Terrain Model (DTM). The contents they express are relative: DSM expresses the height we focus on about the surface of the ground, including the terrain and the objects on it, and DTM only gives the height of the terrain excluding the objects above it. DSM have the information of DTM, therefore it provides us a chance to subtract the DTM from the DSM. Mathematical morphology is a new method applied to Imagery processing and pattern recognition fields. It provides an effective method of subtracting DTM from DSM. But in practical application, the original calculations of these two are in low efficiency. Especially when it comes to a large template or huge block data, the computation speed can be a very headache question. This paper is studying the implementing process of the Open and the Close operators, especially the Erode and the Dilate calculations. Then we have developed two kinds of quick algorithms, which are aim to avoid the repeated calculation, and to enhance the efficiency sharply. The step of the two operations also should be refined, while the disposals are different from each other depending on the distinct configuration of these two kinds of algorithms.

  1. Developmental dissociation in the neural responses to simple multiplication and subtraction problems

    PubMed Central

    Prado, Jérôme; Mutreja, Rachna; Booth, James R.

    2014-01-01

    Mastering single-digit arithmetic during school years is commonly thought to depend upon an increasing reliance on verbally memorized facts. An alternative model, however, posits that fluency in single-digit arithmetic might also be achieved via the increasing use of efficient calculation procedures. To test between these hypotheses, we used a cross-sectional design to measure the neural activity associated with single-digit subtraction and multiplication in 34 children from 2nd to 7th grade. The neural correlates of language and numerical processing were also identified in each child via localizer scans. Although multiplication and subtraction were undistinguishable in terms of behavior, we found a striking developmental dissociation in their neural correlates. First, we observed grade-related increases of activity for multiplication, but not for subtraction, in a language-related region of the left temporal cortex. Second, we found grade-related increases of activity for subtraction, but not for multiplication, in a region of the right parietal cortex involved in the procedural manipulation of numerical quantities. The present results suggest that fluency in simple arithmetic in children may be achieved by both increasing reliance on verbal retrieval and by greater use of efficient quantity-based procedures, depending on the operation. PMID:25089323

  2. Intravenous smart pumps.

    PubMed

    Harding, Andrew D

    2013-01-01

    Intravenous (IV) smart pumps provide substantial safety features during infusion. However, nurses need to understand the requisite education necessary to fully benefit from and improve IV smart pump use and clinical integration. Failure to use IV smart pumps places the nurse and patient at increased risk. PMID:23558918

  3. Minimal subtraction and momentum subtraction in quantum chromodynamics at two-loop order

    SciTech Connect

    Braaten, E.; Leveille, J.P.

    1981-09-01

    The momentum-subtraction coupling constant ..cap alpha../sub MOM/ yields consistently smaller one-loop corrections to many quantum-chromodynamics (QCD) processes than the minimal-subtraction couplings ..cap alpha../sub MS/ and ..cap alpha../sub M/S. By shifting the renormalization scale ..mu.. of ..cap alpha../sub MS/(..mu..), we obtain a minimal-subtraction coupling with the same small one-loop corrections. It is shown, by studying the effective charges of QCD, that at two-loop order this coupling constant will continue to yield corrections to physical quantities that are comparable to those obtained by momentum subtraction. We also introduce a momentum-subtraction scheme which treats the triple-gluon, quark, and ghost vertices equally at one-loop order and is more convenient for higher-order calculations than the MOM scheme.

  4. Digital Subtraction MR Angiography Roadmapping for Magnetic Steerable Catheter Tracking

    PubMed Central

    Martin, Alastair J.; Lillaney, Prasheel; Saeed, Maythem; Losey, Aaron D.; Settecase, Fabio; Evans, Lee; Arenson, Ronald L.; Wilson, Mark W.; Hetts, Steven W.

    2014-01-01

    Purpose To develop a high temporal resolution MR imaging technique that could be employed with magnetically-assisted remote control (MARC) endovascular catheters. Materials and Methods A technique is proposed based on selective intra-arterial injections of dilute MR contrast at the beginning of a fluoroscopic MR angiography acquisition. The initial bolus of contrast is used to establish a vascular roadmap upon which MARC catheters can be tracked. The contrast to noise ratio of the achieved roadmap was assessed in phantoms and in a swine animal model. The ability of the technique to permit navigation of activated MARC catheters through arterial branch points was evaluated. Results The roadmapping mode proved effective in phantoms for tracking objects and achieved a contrast to noise ratio of 35.7 between the intra and extra-vascular space. In vivo, the intra-arterial enhancement strategy produced roadmaps with a contrast to noise ratio of 42.0. The artifact produced by MARC catheter activation provided signal enhancement patterns on the roadmap that experienced interventionalists could track through vascular structures. Conclusion A roadmapping approach with intra-arterial CE-MRA is introduced for navigating the MARC catheter. The technique mitigates the artifact produced by the MARC catheter, greatly limits the required SAR, permits regular roadmap updates due to the low contrast agent requirements, and proved effective in the in vivo setting. PMID:24797218

  5. Fiber Optically Coupled Diode Array Digital Radiography System

    NASA Astrophysics Data System (ADS)

    Sashin, Donald; Sternglass, Ernest J.; Slasky, B. S.; Bron, Klaus M.; Herron, John M.; Kennedy, William H.; Shabason, Leonard; Boyer, Joseph W.; Pollitt, Alma E.; Latchaw, Richard E.

    1982-12-01

    A new type of digital radiography system of very high contrast sensitivity and spatial resolution is described which is based on the use of six linear arrays of self-scanning diodes fiber-optically coupled to a phosphor screen. The high detail of the system results from the fact that 6144 discrete diodes, 1024 per array, scan a field of view of 6 inches wide. A contrast sensitivity five times greater than film is achieved due to the high dynamic range of the diodes combined with the scatter rejection associated with the slit geometry. The entrance radiation exposure per image is 100 mR but could be reduced well below that in the future. Initial clinical experience has demonstrated the advantage of being able to display a single image over a wide range of window levels and window widths at the same time having a high contrast sensitivity in both the dark and light areas of the image. The complete digital radiograph is taken in a second, however the motion unsharpness is held to a minimum by virtue of an effective exposure time of 8 milliseconds. Applications to digital chest radiography and digital intravenous subtraction angiography in over 30 patients have shown the clinical value of this new form of radiography.

  6. Intravenous Flat-Detector Computed Tomography Angiography for Symptomatic Cerebral Vasospasm following Aneurysmal Subarachnoid Hemorrhage

    PubMed Central

    Jeon, Jin Pyeong; Sheen, Seung Hun; Cho, Yong-Jun

    2014-01-01

    The study evaluated the diagnostic accuracy of intravenous flat-detector computed tomography (IV FDCT) angiography in assessing hemodynamically significant cerebral vasospasm in patients with subarachnoid hemorrhage (SAH) with digital subtraction angiography (DSA) as the reference. DSA and IV FDCT were conducted concurrently in patients suspected of having symptomatic cerebral vasospasm postoperatively. The presence and severity of vasospasm were estimated according to location (proximal versus distal). Vasospasm >50% was defined as having hemodynamic significance. Vasospasms <30% were excluded from this analysis to avoid spectrum bias. Twenty-nine patients (311 vessel segments) were measured. The intra- and interobserver agreements were excellent for depicting vasospasm (k = 0.84 and 0.74, resp.). IV FDCT showed a sensitivity of 95.7%, specificity of 92.3%, positive predictive value of 93.6%, and negative predictive value of 94.7% for detecting vasospasm (>50%) with DSA as the reference. Bland-Altman plots revealed good agreement of assessing vasospasm between the two tests. The discrepancy of vasospasm severity was more noted in the distal location with high-severity. However, it was not statistically significant (Spearman's rank test; r = 0.15, P = 0.35). Therefore, IV FDCT could be a feasible noninvasive test to evaluate suspected significant vasospasm in SAH. PMID:25383367

  7. Subtraction CT angiography for the detection of intracranial aneurysms: A meta-analysis

    PubMed Central

    FENG, TIAN-YING; HAN, XUE-FENG; LANG, RUI; WANG, FEI; WU, QIONG

    2016-01-01

    The aim of this meta-analysis was to investigate the accuracy of subtraction computed tomography angiography (CTA) for diagnosing intracranial aneurysms. A systematic literature search up to January 1, 2013 was performed in PubMed. Two independent reviewers selected 8 studies that compared subtraction CTA with digital subtraction angiography. Data from the studies were used to construct a 2×2 contingency table on a per-patient basis in ≥5 diseased and 5 non-diseased patients, with additional data on a per-aneurysm basis. Overall, subtraction CTA had a pooled sensitivity of 99% [95% confidence interval (CI), 95–100%] and specificity of 94% (95% CI, 86–97%) for detecting and ruling out cerebral aneurysms, respectively, on a per-patient basis. On a per-aneurysm basis, the pooled sensitivity was 96% (95% CI, 90–99%), and the specificity was 91% (95% CI, 85–95%). In conclusion, subtraction CTA is a highly sensitive, specific and non-invasive method for the diagnosis and evaluation of intracranial aneurysms. PMID:27168830

  8. Children's Misconceptions about the Multidigit Subtraction Algorithm.

    ERIC Educational Resources Information Center

    Cauley, Kathleen M.

    This study probed children's reasoning about both correct and incorrect but plausible statements of hypothetical children concerning the concepts of subtraction, with the intention of examining misconceptions in greater depth. Eight third graders, 14 fourth graders, and 14 fifth graders were interviewed individually to assess their understanding…

  9. Diagnosis of Subtraction Bugs Using Bayesian Networks

    ERIC Educational Resources Information Center

    Lee, Jihyun; Corter, James E.

    2011-01-01

    Diagnosis of misconceptions or "bugs" in procedural skills is difficult because of their unstable nature. This study addresses this problem by proposing and evaluating a probability-based approach to the diagnosis of bugs in children's multicolumn subtraction performance using Bayesian networks. This approach assumes a causal network relating…

  10. Verification of IEEE Compliant Subtractive Division Algorithms

    NASA Technical Reports Server (NTRS)

    Miner, Paul S.; Leathrum, James F., Jr.

    1996-01-01

    A parameterized definition of subtractive floating point division algorithms is presented and verified using PVS. The general algorithm is proven to satisfy a formal definition of an IEEE standard for floating point arithmetic. The utility of the general specification is illustrated using a number of different instances of the general algorithm.

  11. Children's Profiles of Addition and Subtraction Understanding

    ERIC Educational Resources Information Center

    Canobi, Katherine H.

    2005-01-01

    The current research explored children's ability to recognize and explain different concepts both with and without reference to physical objects so as to provide insight into the development of children's addition and subtraction understanding. In Study 1, 72 7- to 9-year-olds judged and explained a puppet's activities involving three conceptual…

  12. Polygon Subtraction in 2 or 3 Dimensions

    SciTech Connect

    Wilson, John E.

    2013-10-01

    When searching for computer code to perform the ubiquitous task of subtracting one polygon from another, it is difficult to find real examples and detailed explanations. This paper outlines the step-by-step process necessary to accomplish this basic task.

  13. INTRAVENOUS ETHER ANESTHESIA

    PubMed Central

    Eger, Edmond I.; Johnson, Edward A.

    1963-01-01

    From a study of intravenous ether anesthesia, it was concluded that ether diluted to a 5 per cent solution in 5 per cent dextrose and water may be used to induce and maintain a smooth and easily controlled anesthetic state similar to that obtained with inhalation ether but without the dependence of the latter technique on ventilation. Cough and laryngospasm were absent. Adequate spontaneous respiration can be maintained with this technique. The technique is particularly useful in endoscopy during which the airway is often not available for anesthetic administration. PMID:14051486

  14. Hardware Implementation of a Bilateral Subtraction Filter

    NASA Technical Reports Server (NTRS)

    Huertas, Andres; Watson, Robert; Villalpando, Carlos; Goldberg, Steven

    2009-01-01

    A bilateral subtraction filter has been implemented as a hardware module in the form of a field-programmable gate array (FPGA). In general, a bilateral subtraction filter is a key subsystem of a high-quality stereoscopic machine vision system that utilizes images that are large and/or dense. Bilateral subtraction filters have been implemented in software on general-purpose computers, but the processing speeds attainable in this way even on computers containing the fastest processors are insufficient for real-time applications. The present FPGA bilateral subtraction filter is intended to accelerate processing to real-time speed and to be a prototype of a link in a stereoscopic-machine- vision processing chain, now under development, that would process large and/or dense images in real time and would be implemented in an FPGA. In terms that are necessarily oversimplified for the sake of brevity, a bilateral subtraction filter is a smoothing, edge-preserving filter for suppressing low-frequency noise. The filter operation amounts to replacing the value for each pixel with a weighted average of the values of that pixel and the neighboring pixels in a predefined neighborhood or window (e.g., a 9 9 window). The filter weights depend partly on pixel values and partly on the window size. The present FPGA implementation of a bilateral subtraction filter utilizes a 9 9 window. This implementation was designed to take advantage of the ability to do many of the component computations in parallel pipelines to enable processing of image data at the rate at which they are generated. The filter can be considered to be divided into the following parts (see figure): a) An image pixel pipeline with a 9 9- pixel window generator, b) An array of processing elements; c) An adder tree; d) A smoothing-and-delaying unit; and e) A subtraction unit. After each 9 9 window is created, the affected pixel data are fed to the processing elements. Each processing element is fed the pixel value for

  15. Effect of color coding and subtraction on the accuracy of contrast echocardiography

    NASA Technical Reports Server (NTRS)

    Pasquet, A.; Greenberg, N.; Brunken, R.; Thomas, J. D.; Marwick, T. H.

    1999-01-01

    BACKGROUND: Contrast echocardiography may be used to assess myocardial perfusion. However, gray scale assessment of myocardial contrast echocardiography (MCE) is difficult because of variations in regional backscatter intensity, difficulties in distinguishing varying shades of gray, and artifacts or attenuation. We sought to determine whether the assessment of rest myocardial perfusion by MCE could be improved with subtraction and color coding. METHODS AND RESULTS: MCE was performed in 31 patients with previous myocardial infarction with a 2nd generation agent (NC100100, Nycomed AS), using harmonic triggered or continuous imaging and gain settings were kept constant throughout the study. Digitized images were post processed by subtraction of baseline from contrast data and colorized to reflect the intensity of myocardial contrast. Gray scale MCE alone, MCE images combined with baseline and subtracted colorized images were scored independently using a 16 segment model. The presence and severity of myocardial contrast abnormalities were compared with perfusion defined by rest MIBI-SPECT. Segments that were not visualized by continuous (17%) or triggered imaging (14%) after color processing were excluded from further analysis. The specificity of gray scale MCE alone (56%) or MCE combined with baseline 2D (47%) was significantly enhanced by subtraction and color coding (76%, p<0.001) of triggered images. The accuracy of the gray scale approaches (respectively 52% and 47%) was increased to 70% (p<0.001). Similarly, for continuous images, the specificity of gray scale MCE with and without baseline comparison was 23% and 42% respectively, compared with 60% after post processing (p<0.001). The accuracy of colorized images (59%) was also significantly greater than gray scale MCE (43% and 29%, p<0.001). The sensitivity of MCE for both acquisitions was not altered by subtraction. CONCLUSION: Post-processing with subtraction and color coding significantly improves the accuracy

  16. The Effects of Computer-Assisted Instruction on Student Achievement in Addition and Subtraction at First Grade Level.

    ERIC Educational Resources Information Center

    Spivey, Patsy M.

    This study was conducted to determine whether the traditional classroom approach to instruction involving the addition and subtraction of number facts (digits 0-6) is more or less effective than the traditional classroom approach plus a commercially-prepared computer game. A pretest-posttest control group design was used with two groups of first…

  17. Subtractive Structural Modification of Morpho Butterfly Wings.

    PubMed

    Shen, Qingchen; He, Jiaqing; Ni, Mengtian; Song, Chengyi; Zhou, Lingye; Hu, Hang; Zhang, Ruoxi; Luo, Zhen; Wang, Ge; Tao, Peng; Deng, Tao; Shang, Wen

    2015-11-11

    Different from studies of butterfly wings through additive modification, this work for the first time studies the property change of butterfly wings through subtractive modification using oxygen plasma etching. The controlled modification of butterfly wings through such subtractive process results in gradual change of the optical properties, and helps the further understanding of structural optimization through natural evolution. The brilliant color of Morpho butterfly wings is originated from the hierarchical nanostructure on the wing scales. Such nanoarchitecture has attracted a lot of research effort, including the study of its optical properties, its potential use in sensing and infrared imaging, and also the use of such structure as template for the fabrication of high-performance photocatalytic materials. The controlled subtractive processes provide a new path to modify such nanoarchitecture and its optical property. Distinct from previous studies on the optical property of the Morpho wing structure, this study provides additional experimental evidence for the origination of the optical property of the natural butterfly wing scales. The study also offers a facile approach to generate new 3D nanostructures using butterfly wings as the templates and may lead to simpler structure models for large-scale man-made structures than those offered by original butterfly wings. PMID:26397977

  18. Ambient-Light-Canceling Camera Using Subtraction of Frames

    NASA Technical Reports Server (NTRS)

    Morookian, John Michael

    2004-01-01

    The ambient-light-canceling camera (ALCC) is a proposed near-infrared electronic camera that would utilize a combination of (1) synchronized illumination during alternate frame periods and (2) subtraction of readouts from consecutive frames to obtain images without a background component of ambient light. The ALCC is intended especially for use in tracking the motion of an eye by the pupil center corneal reflection (PCCR) method. Eye tracking by the PCCR method has shown potential for application in human-computer interaction for people with and without disabilities, and for noninvasive monitoring, detection, and even diagnosis of physiological and neurological deficiencies. In the PCCR method, an eye is illuminated by near-infrared light from a lightemitting diode (LED). Some of the infrared light is reflected from the surface of the cornea. Some of the infrared light enters the eye through the pupil and is reflected from back of the eye out through the pupil a phenomenon commonly observed as the red-eye effect in flash photography. An electronic camera is oriented to image the user's eye. The output of the camera is digitized and processed by algorithms that locate the two reflections. Then from the locations of the centers of the two reflections, the direction of gaze is computed. As described thus far, the PCCR method is susceptible to errors caused by reflections of ambient light. Although a near-infrared band-pass optical filter can be used to discriminate against ambient light, some sources of ambient light have enough in-band power to compete with the LED signal. The mode of operation of the ALCC would complement or supplant spectral filtering by providing more nearly complete cancellation of the effect of ambient light. In the operation of the ALCC, a near-infrared LED would be pulsed on during one camera frame period and off during the next frame period. Thus, the scene would be illuminated by both the LED (signal) light and the ambient (background) light

  19. Intravenous Fluid Generation System

    NASA Technical Reports Server (NTRS)

    McQuillen, John; McKay, Terri; Brown, Daniel; Zoldak, John

    2013-01-01

    The ability to stabilize and treat patients on exploration missions will depend on access to needed consumables. Intravenous (IV) fluids have been identified as required consumables. A review of the Space Medicine Exploration Medical Condition List (SMEMCL) lists over 400 medical conditions that could present and require treatment during ISS missions. The Intravenous Fluid Generation System (IVGEN) technology provides the scalable capability to generate IV fluids from indigenous water supplies. It meets USP (U.S. Pharmacopeia) standards. This capability was performed using potable water from the ISS; water from more extreme environments would need preconditioning. The key advantage is the ability to filter mass and volume, providing the equivalent amount of IV fluid: this is critical for remote operations or resource- poor environments. The IVGEN technology purifies drinking water, mixes it with salt, and transfers it to a suitable bag to deliver a sterile normal saline solution. Operational constraints such as mass limitations and lack of refrigeration may limit the type and volume of such fluids that can be carried onboard the spacecraft. In addition, most medical fluids have a shelf life that is shorter than some mission durations. Consequently, the objective of the IVGEN experiment was to develop, design, and validate the necessary methodology to purify spacecraft potable water into a normal saline solution, thus reducing the amount of IV fluids that are included in the launch manifest. As currently conceived, an IVGEN system for a space exploration mission would consist of an accumulator, a purifier, a mixing assembly, a salt bag, and a sterile bag. The accumulator is used to transfer a measured amount of drinking water from the spacecraft to the purifier. The purifier uses filters to separate any air bubbles that may have gotten trapped during the drinking water transfer from flowing through a high-quality deionizing cartridge that removes the impurities in

  20. Subtraction threshold for an isotropic fluorescence emission difference microscope

    NASA Astrophysics Data System (ADS)

    Wang, Nan; Kobayashi, Takayoshi

    2015-12-01

    Isotropic fluorescence emission difference microscopy proposed recently provides a simple method to enhance the spatial resolution in three-dimensions (3D) for fluorescence imaging. However, the subtraction threshold to achieve the condition for appropriately resolving the sample in 3D have not been studied. Then the subtraction factors used in this type of microscopes are still experientially chosen. Based on vector diffraction theory and a 3D numerical model developed here, the subtraction threshold is numerically investigated for the isotropic fluorescence subtraction microscopy. The subtraction factors and peak intensities at the threshold are obtained and comparied both in lateral and axial planes for achieving most appropriate subtraction and inspecting the isotropic characteristic. The effects of radius ratios of implemented 0-π annular phase plate for generating three dimensional donut spot on the subtracted resolution, peak intensity and negative sidebands are also discussed.

  1. Intravenous acetaminophen use in pediatrics.

    PubMed

    Shastri, Nirav

    2015-06-01

    Acetaminophen is a commonly used pediatric medication that has recently been approved for intravenous use in the United States. The purpose of this article was to review the pharmacodynamics, indications, contraindications, and precautions for the use of intravenous acetaminophen in pediatrics. PMID:26035501

  2. Spectral amplitude coding OCDMA using and subtraction technique.

    PubMed

    Hasoon, Feras N; Aljunid, S A; Samad, M D A; Abdullah, Mohamad Khazani; Shaari, Sahbudin

    2008-03-20

    An optical decoding technique is proposed for a spectral-amplitude-coding-optical code division multiple access, namely, the AND subtraction technique. The theory is being elaborated and experimental results have been done by comparing a double-weight code against the existing code, Hadamard. We have proved that the and subtraction technique gives better bit error rate performance than the conventional complementary subtraction technique against the received power level. PMID:18709073

  3. Renormalization of quark bilinear operators in a momentum-subtraction scheme with a nonexceptional subtraction point

    SciTech Connect

    Sturm, C.; Soni, A.; Aoki, Y.; Christ, N. H.; Izubuchi, T.; Sachrajda, C. T. C.

    2009-07-01

    We extend the Rome-Southampton regularization independent momentum-subtraction renormalization scheme (RI/MOM) for bilinear operators to one with a nonexceptional, symmetric subtraction point. Two-point Green's functions with the insertion of quark bilinear operators are computed with scalar, pseudoscalar, vector, axial-vector and tensor operators at one-loop order in perturbative QCD. We call this new scheme RI/SMOM, where the S stands for 'symmetric'. Conversion factors are derived, which connect the RI/SMOM scheme and the MS scheme and can be used to convert results obtained in lattice calculations into the MS scheme. Such a symmetric subtraction point involves nonexceptional momenta implying a lattice calculation with substantially suppressed contamination from infrared effects. Further, we find that the size of the one-loop corrections for these infrared improved kinematics is substantially decreased in the case of the pseudoscalar and scalar operator, suggesting a much better behaved perturbative series. Therefore it should allow us to reduce the error in the determination of the quark mass appreciably.

  4. A Proposed Instructional Theory for Integer Addition and Subtraction

    ERIC Educational Resources Information Center

    Stephan, Michelle; Akyuz, Didem

    2012-01-01

    This article presents the results of a 7th-grade classroom teaching experiment that supported students' understanding of integer addition and subtraction. The experiment was conducted to test and revise a hypothetical learning trajectory so as to propose a potential instructional theory for integer addition and subtraction. The instructional…

  5. Evolutionary Processes in the Development of Errors in Subtraction Algorithms

    ERIC Educational Resources Information Center

    Fernandez, Ricardo Lopez; Garcia, Ana B. Sanchez

    2008-01-01

    The study of errors made in subtraction is a research subject approached from different theoretical premises that affect different components of the algorithmic process as triggers of their generation. In the following research an attempt has been made to investigate the typology and nature of errors which occur in subtractions and their evolution…

  6. Developing a Model to Support Students in Solving Subtraction

    ERIC Educational Resources Information Center

    Murdiyani, Nila Mareta; Zulkardi; Putri, Ratu Ilma Indra; van Eerde, Dolly; van Galen, Frans

    2013-01-01

    Subtraction has two meanings and each meaning leads to the different strategies. The meaning of "taking away something" suggests a direct subtraction, while the meaning of "determining the difference between two numbers" is more likely to be modeled as indirect addition. Many prior researches found that the second meaning and…

  7. When Should We Teach Regrouping in Addition and Subtraction.

    ERIC Educational Resources Information Center

    Engelhardt, Jon M.; Usnick, Virginia

    1991-01-01

    Presented are the results of two pilot studies about multidigit addition and subtraction. The results are discussed in relation to possible alternative sequences in the teaching of addition and subtraction and the relationship between basic fact mastery and numeration concept attainment. (CW)

  8. Fostering First-Graders' Fluency with Basic Subtraction Combinations

    ERIC Educational Resources Information Center

    Baroody, Arthur J.; Purpura, David J.; Eiland, Michael D.; Reid, Erin E.

    2012-01-01

    Subtraction combinations are particularly challenging for children to learn (Kraner, 1980; Smith, 1921; see Cowan, 2003, for a review). This study examines whether the group of children receiving the "experimental subtraction-as-addition" training outperform the "control" group, which received training on a different reasoning strategy involving…

  9. Orthostatic stability with intravenous levodopa

    PubMed Central

    Siddiqi, Shan H.; Creech, Mary L.

    2015-01-01

    Intravenous levodopa has been used in a multitude of research studies due to its more predictable pharmacokinetics compared to the oral form, which is used frequently as a treatment for Parkinson’s disease (PD). Levodopa is the precursor for dopamine, and intravenous dopamine would strongly affect vascular tone, but peripheral decarboxylase inhibitors are intended to block such effects. Pulse and blood pressure, with orthostatic changes, were recorded before and after intravenous levodopa or placebo—after oral carbidopa—in 13 adults with a chronic tic disorder and 16 tic-free adult control subjects. Levodopa caused no statistically or clinically significant changes in blood pressure or pulse. These data add to previous data that support the safety of i.v. levodopa when given with adequate peripheral inhibition of DOPA decarboxylase. PMID:26336641

  10. Digitally Controlled Beam Attenuator

    NASA Astrophysics Data System (ADS)

    Peppler, W. W.; Kudva, B.; Dobbins, J. T.; Lee, C. S.; Van Lysel, M. S.; Hasegawa, B. H.; Mistretta, C. A.

    1982-12-01

    In digital fluorographic techniques the video camera must accommodate a wide dynamic range due to the large variation in the subject thickness within the field of view. Typically exposure factors and the optical aperture are selected such that the maximum video signal is obtained in the most transmissive region of the subject. Consequently, it has been shown that the signal-to-noise ratio is severely reduced in the dark regions. We have developed a prototype digital beam attenuator (DBA) which will alleviate this and some related problems in digital fluorography. The prototype DBA consists of a 6x6 array of pistons which are individually controlled. A membrane containing an attenuating solu-tion of (CeC13) in water and the piston matrix are placed between the x-ray tube and the subject. Under digital control the pistons are moved into the attenuating material in order to adjust the beam intensity over each of the 36 cells. The DBA control unit which digitizes the image during patient positioning will direct the pistons under hydraulic control to produce a uniform x-ray field exiting the subject. The pistons were designed to produce very little structural background in the image. In subtraction studies any structure would be cancelled. For non-subtraction studies such as cine-cardiology we are considering higher cell densities (eg. 64x64). Due to the narrow range of transmission provided by the DBA, in such studies ultra-high contrast films could be used to produce a high resolution quasi-subtraction display. Additional benefits of the DBA are: 1) reduced dose to the bright image areas when the dark areas are properly exposed. 2) improved scatter and glare to primary ratios, leading to improved contrast in the dark areas.

  11. Nucleon-nucleon scattering within a multiple subtractive renormalization approach

    SciTech Connect

    Timoteo, V. S.; Frederico, T.; Delfino, A.; Tomio, Lauro

    2011-06-15

    We present a methodology to renormalize the nucleon-nucleon interaction in momentum space, using a recursive multiple subtraction approach that prescinds from a cutoff regularization, to construct the kernel of the scattering equation. The subtracted scattering equation is solved with the next-leading-order and next-to-next-leading-order interactions. The results are presented for all partial waves up to j=2, fitted to low-energy experimental data. In this renormalization group invariant approach, the subtraction energy emerges as a renormalization scale and the momentum associated with it comes to be about the QCD scale ({Lambda}{sub QCD}), irrespectively to the partial wave.

  12. Dual-tracer background subtraction approach for fluorescent molecular tomography

    PubMed Central

    Holt, Robert W.; El-Ghussein, Fadi; Davis, Scott C.; Samkoe, Kimberley S.; Gunn, Jason R.; Leblond, Frederic

    2013-01-01

    Abstract. Diffuse fluorescence tomography requires high contrast-to-background ratios to accurately reconstruct inclusions of interest. This is a problem when imaging the uptake of fluorescently labeled molecularly targeted tracers in tissue, which can result in high levels of heterogeneously distributed background uptake. We present a dual-tracer background subtraction approach, wherein signal from the uptake of an untargeted tracer is subtracted from targeted tracer signal prior to image reconstruction, resulting in maps of targeted tracer binding. The approach is demonstrated in simulations, a phantom study, and in a mouse glioma imaging study, demonstrating substantial improvement over conventional and homogenous background subtraction image reconstruction approaches. PMID:23292612

  13. [Lethal intravenous injection of benzine].

    PubMed

    Zirwes, Christian; Ritz-Timme, Stefanie; Hinsch, Nora; Kardel, Bernd; Hartung, Benno

    2015-01-01

    A man who suffered from chronic pain syndrome died two days after intravenous injection of 2 ml benzine. Previous suicide attempts by drug intoxication and strangulation had failed. Death occurred due to multi-organ failure. We present the results of the clinical, morphological and toxicological examinations performed. PMID:26548034

  14. Background Subtraction for Automated Multisensor Surveillance: A Comprehensive Review

    NASA Astrophysics Data System (ADS)

    Cristani, Marco; Farenzena, Michela; Bloisi, Domenico; Murino, Vittorio

    2010-12-01

    Background subtraction is a widely used operation in the video surveillance, aimed at separating the expected scene (the background) from the unexpected entities (the foreground). There are several problems related to this task, mainly due to the blurred boundaries between background and foreground definitions. Therefore, background subtraction is an open issue worth to be addressed under different points of view. In this paper, we propose a comprehensive review of the background subtraction methods, that considers also channels other than the sole visible optical one (such as the audio and the infrared channels). In addition to the definition of novel kinds of background, the perspectives that these approaches open up are very appealing: in particular, the multisensor direction seems to be well-suited to solve or simplify several hoary background subtraction problems. All the reviewed methods are organized in a novel taxonomy that encapsulates all the brand-new approaches in a seamless way.

  15. An auto-adaptive background subtraction method for Raman spectra.

    PubMed

    Xie, Yi; Yang, Lidong; Sun, Xilong; Wu, Dewen; Chen, Qizhen; Zeng, Yongming; Liu, Guokun

    2016-05-15

    Background subtraction is a crucial step in the preprocessing of Raman spectrum. Usually, parameter manipulating of the background subtraction method is necessary for the efficient removal of the background, which makes the quality of the spectrum empirically dependent. In order to avoid artificial bias, we proposed an auto-adaptive background subtraction method without parameter adjustment. The main procedure is: (1) select the local minima of spectrum while preserving major peaks, (2) apply an interpolation scheme to estimate background, (3) and design an iteration scheme to improve the adaptability of background subtraction. Both simulated data and Raman spectra have been used to evaluate the proposed method. By comparing the backgrounds obtained from three widely applied methods: the polynomial, the Baek's and the airPLS, the auto-adaptive method meets the demand of practical applications in terms of efficiency and accuracy. PMID:26950502

  16. Soft-collinear factorization and zero-bin subtractions

    SciTech Connect

    Chiu Juiyu; Fuhrer, Andreas; Kelley, Randall; Manohar, Aneesh V.; Hoang, Andre H.

    2009-03-01

    We study the Sudakov form factor for a spontaneously broken gauge theory using a (new) {delta}-regulator. To be well defined, the effective theory requires zero-bin subtractions for the collinear sectors. The zero-bin subtractions depend on the gauge boson mass M and are not scaleless. They have both finite and 1/{epsilon} contributions and are needed to give the correct anomalous dimension and low-scale matching contributions. We also demonstrate the necessity of zero-bin subtractions for soft-collinear factorization. We find that after zero-bin subtractions the form factor is the sum of the collinear contributions minus a soft mass-mode contribution, in agreement with a previous result of Idilbi and Mehen in QCD. This appears to conflict with the method-of-regions approach, where one gets the sum of contributions from different regions.

  17. An auto-adaptive background subtraction method for Raman spectra

    NASA Astrophysics Data System (ADS)

    Xie, Yi; Yang, Lidong; Sun, Xilong; Wu, Dewen; Chen, Qizhen; Zeng, Yongming; Liu, Guokun

    2016-05-01

    Background subtraction is a crucial step in the preprocessing of Raman spectrum. Usually, parameter manipulating of the background subtraction method is necessary for the efficient removal of the background, which makes the quality of the spectrum empirically dependent. In order to avoid artificial bias, we proposed an auto-adaptive background subtraction method without parameter adjustment. The main procedure is: (1) select the local minima of spectrum while preserving major peaks, (2) apply an interpolation scheme to estimate background, (3) and design an iteration scheme to improve the adaptability of background subtraction. Both simulated data and Raman spectra have been used to evaluate the proposed method. By comparing the backgrounds obtained from three widely applied methods: the polynomial, the Baek's and the airPLS, the auto-adaptive method meets the demand of practical applications in terms of efficiency and accuracy.

  18. Improvements in floating point addition/subtraction operations

    DOEpatents

    Farmwald, P.M.

    1984-02-24

    Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  19. Enhancing quantum entanglement by photon addition and subtraction

    NASA Astrophysics Data System (ADS)

    Navarrete-Benlloch, Carlos; García-Patrón, Raúl; Shapiro, Jeffrey H.; Cerf, Nicolas J.

    2012-07-01

    The non-Gaussian operations effected by adding or subtracting a photon on entangled optical beams emerging from a parametric down-conversion process have been suggested to enhance entanglement. Heralded photon addition or subtraction is, as a matter of fact, at the heart of continuous-variable entanglement distillation. The use of such processes has recently been experimentally demonstrated in the context of the generation of optical coherent-state superpositions or the verification of canonical commutation relations. Here, we carry out a systematic study of the effect of local photon additions and subtractions on a two-mode squeezed vacuum state, showing that the entanglement generally increases with the number of such operations. This is analytically proven when additions or subtractions are restricted to one mode only, while we observe that the highest entanglement is achieved when these operations are equally shared between the two modes. We also note that adding photons typically provides a stronger entanglement enhancement than subtracting photons, while photon subtraction performs better in terms of energy efficiency. Furthermore, we analyze the interplay between entanglement and non-Gaussianity, showing that it is more subtle than previously expected.

  20. Advanced Background Subtraction Applied to Aeroacoustic Wind Tunnel Testing

    NASA Technical Reports Server (NTRS)

    Bahr, Christopher J.; Horne, William C.

    2015-01-01

    An advanced form of background subtraction is presented and applied to aeroacoustic wind tunnel data. A variant of this method has seen use in other fields such as climatology and medical imaging. The technique, based on an eigenvalue decomposition of the background noise cross-spectral matrix, is robust against situations where isolated background auto-spectral levels are measured to be higher than levels of combined source and background signals. It also provides an alternate estimate of the cross-spectrum, which previously might have poor definition for low signal-to-noise ratio measurements. Simulated results indicate similar performance to conventional background subtraction when the subtracted spectra are weaker than the true contaminating background levels. Superior performance is observed when the subtracted spectra are stronger than the true contaminating background levels. Experimental results show limited success in recovering signal behavior for data where conventional background subtraction fails. They also demonstrate the new subtraction technique's ability to maintain a proper coherence relationship in the modified cross-spectral matrix. Beam-forming and de-convolution results indicate the method can successfully separate sources. Results also show a reduced need for the use of diagonal removal in phased array processing, at least for the limited data sets considered.

  1. Intravenous magnetic nanoparticle cancer hyperthermia

    PubMed Central

    Huang, Hui S; Hainfeld, James F

    2013-01-01

    Magnetic nanoparticles heated by an alternating magnetic field could be used to treat cancers, either alone or in combination with radiotherapy or chemotherapy. However, direct intratumoral injections suffer from tumor incongruence and invasiveness, typically leaving undertreated regions, which lead to cancer regrowth. Intravenous injection more faithfully loads tumors, but, so far, it has been difficult achieving the necessary concentration in tumors before systemic toxicity occurs. Here, we describe use of a magnetic nanoparticle that, with a well-tolerated intravenous dose, achieved a tumor concentration of 1.9 mg Fe/g tumor in a subcutaneous squamous cell carcinoma mouse model, with a tumor to non-tumor ratio > 16. With an applied field of 38 kA/m at 980 kHz, tumors could be heated to 60°C in 2 minutes, durably ablating them with millimeter (mm) precision, leaving surrounding tissue intact. PMID:23901270

  2. Anaphylactic reaction to intravenous diclofenac.

    PubMed

    Singh, Ranju; Bansal, Deepak; Baduni, Neha; Vajifdar, Homay

    2011-01-01

    Diclofenac sodium is a non-steroidal anti-inflammatory drug widely used as an opioid sparing agent for postoperative analgesia. Anaphylaxis due to intravenous diclofenac sodium is very rare. We report a case of anaphylactic reaction to IV diclofenac sodium, occurring postoperatively in a 25-year-old primigravida, the clinical features of which mimicked pulmonary embolism. The rarity, clinical importance and the diagnostic dilemma associated prompted us to report this case. PMID:21633544

  3. Intravenous Solutions for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Miller, Fletcher J.; Niederhaus, Charles; Barlow, Karen; Griffin, DeVon

    2007-01-01

    This paper describes the intravenous (IV) fluids requirements being developed for medical care during NASA s future exploration class missions. Previous research on IV solution generation and mixing in space is summarized. The current exploration baseline mission profiles are introduced, potential medical conditions described and evaluated for fluidic needs, and operational issues assessed. We briefly introduce potential methods for generating IV fluids in microgravity. Conclusions on the recommended fluid volume requirements are presented.

  4. Comparison of iodine K-edge subtraction and fluorescence subtraction imaging in an animal system

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Zhu, Y.; Bewer, B.; Zhang, L.; Korbas, M.; Pickering, I. J.; George, G. N.; Gupta, M.; Chapman, D.

    2008-09-01

    K-Edge Subtraction (KES) utilizes the discontinuity in the X-ray absorption across the absorption edge of the selected contrast element and creates an image of the projected density of the contrast element from two images acquired just above and below the K-edge of the contrast element. KES has proved to be powerful in coronary angiography, micro-angiography, bronchography, and lymphatic imaging. X-ray fluorescence imaging is a successful technique for the detection of dilute quantities of elements in specimens. However, its application at high X-ray energies (e.g. at the iodine K-edge) is complicated by significant Compton background, which may enter the energy window set for the contrast material's fluorescent X-rays. Inspired by KES, Fluorescence Subtraction Imaging (FSI) is a technique for high-energy (>20 keV) fluorescence imaging using two different incident beam energies just above and below the absorption edge of a contrast element (e.g. iodine). The below-edge image can be assumed as a "background" image, which includes Compton scatter and fluorescence from other elements. The above-edge image will contain nearly identical spectral content as the below-edge image but will contain the additional fluorescence of the contrast element. This imaging method is especially promising with thick objects with dilute contrast materials, significant Compton background, and/or competing fluorescence lines from other materials. A quality factor is developed to facilitate the comparison. The theoretical value of the quality factor sets the upper limit that an imaging method can achieve when the noise is Poisson limited. The measured value of this factor makes two or more imaging methods comparable. Using the Hard X-ray Micro-Analysis (HXMA) beamline at the Canadian Light Source (CLS), the techniques of FSI and KES were critically compared, with reference to radiation dose, image acquisition time, resolution, signal-to-noise ratios, and quality factor.

  5. Appearance of the canine meninges in subtraction magnetic resonance images.

    PubMed

    Lamb, Christopher R; Lam, Richard; Keenihan, Erin K; Frean, Stephen

    2014-01-01

    The canine meninges are not visible as discrete structures in noncontrast magnetic resonance (MR) images, and are incompletely visualized in T1-weighted, postgadolinium images, reportedly appearing as short, thin curvilinear segments with minimal enhancement. Subtraction imaging facilitates detection of enhancement of tissues, hence may increase the conspicuity of meninges. The aim of the present study was to describe qualitatively the appearance of canine meninges in subtraction MR images obtained using a dynamic technique. Images were reviewed of 10 consecutive dogs that had dynamic pre- and postgadolinium T1W imaging of the brain that was interpreted as normal, and had normal cerebrospinal fluid. Image-anatomic correlation was facilitated by dissection and histologic examination of two canine cadavers. Meningeal enhancement was relatively inconspicuous in postgadolinium T1-weighted images, but was clearly visible in subtraction images of all dogs. Enhancement was visible as faint, small-rounded foci compatible with vessels seen end on within the sulci, a series of larger rounded foci compatible with vessels of variable caliber on the dorsal aspect of the cerebral cortex, and a continuous thin zone of moderate enhancement around the brain. Superimposition of color-encoded subtraction images on pregadolinium T1- and T2-weighted images facilitated localization of the origin of enhancement, which appeared to be predominantly dural, with relatively few leptomeningeal structures visible. Dynamic subtraction MR imaging should be considered for inclusion in clinical brain MR protocols because of the possibility that its use may increase sensitivity for lesions affecting the meninges. PMID:24833219

  6. Magnification Embossed Radiography Utilizing Image-Shifting Subtraction Program

    NASA Astrophysics Data System (ADS)

    Akihiro Osawa,; Manabu Watanabe,; Eiichi Sato,; Hiroshi Matsukiyo,; Toshiyuki Enomoto,; Jiro Nagao,; Purkhet Abderyim,; Katsuo Aizawa,; Etsuro Tanaka,; Hidezo Mori,; Toshiaki Kawai,; Akira Ogawa,; Kiyomi Takahashi,; Shigehiro Sato,; Jun Onagawa,

    2010-03-01

    We developed an image-shifting subtraction program and carried out magnification embossed radiography (MER) utilizing single- and dual-energy subtractions. In particular, dual-energy subtraction was carried out to decrease the absorption contrast of unnecessary regions. The contrast resolution of the target region was increased by the use of subtraction software and a linear-contrast system in a flat-panel detector (FPD). The X-ray generator had a 100-μm-focus tube, and the subtractions were performed at tube voltages of 40 and 70 kV, a tube current of 0.50 mA, and an X-ray exposure time of 5.0 s. MER images with threefold magnification were obtained using the FPD with a pixel size of 48× 48 μm2, and the shifting dimensions of the imaged object in the horizontal and vertical directions ranged from 48 to 192 μm. At a shifting distance ranging from 48 to 144 μm, the spatial resolutions in the horizontal and vertical directions measured with a lead test chart were both 50 μm. In the MER of nonliving animals, we obtained high-contrast embossed images of fine bones, gadolinium oxide particles in blood vessels, and iodine-based microspheres in coronary arteries of approximately 100 μm diameter.

  7. Embossed radiography utilizing an image-shifting subtraction program

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Osawa, Akihiro; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Watanabe, Manabu; Takahashi, Kiyomi; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2010-07-01

    We developed an image-shifting subtraction program and carried out embossed radiography (ER) utilizing single- and dual-energy subtractions. In particular, dual-energy subtraction was carried out to decrease the absorption contrast of unnecessary regions. The contrast resolution of a target region was increased using the subtraction program and a linear-contrast system in a flat panel detector (FPD). The X-ray generator had a 100 μm-focus tube, and the subtractions were performed at tube voltages of 40 and 70 kV, a tube current of 0.50 mA, and an X-ray exposure time of 5.0 s. ER was achieved with cohesion imaging using the FPD with pixel sizes of 48×48 μm 2, and the shifting dimension of an object in the horizontal and vertical directions ranged from 48 to 96 μm. At a shifting distance of 96 μm, the spatial resolutions in the horizontal and vertical directions measured with a lead test chart were both 83 μm. In ER of animal phantoms, we obtained high-contrast embossed images of fine bones, gadolinium oxide particles in blood vessels, iodine-based microspheres in coronary arteries approximately 100 μm in diameter.

  8. Magnification Embossed Radiography Utilizing Image-Shifting Subtraction Program

    NASA Astrophysics Data System (ADS)

    Osawa, Akihiro; Watanabe, Manabu; Sato, Eiichi; Matsukiyo, Hiroshi; Enomoto, Toshiyuki; Nagao, Jiro; Abderyim, Purkhet; Aizawa, Katsuo; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ogawa, Akira; Takahashi, Kiyomi; Sato, Shigehiro; Onagawa, Jun

    2010-03-01

    We developed an image-shifting subtraction program and carried out magnification embossed radiography (MER) utilizing single- and dual-energy subtractions. In particular, dual-energy subtraction was carried out to decrease the absorption contrast of unnecessary regions. The contrast resolution of the target region was increased by the use of subtraction software and a linear-contrast system in a flat-panel detector (FPD). The X-ray generator had a 100-µm-focus tube, and the subtractions were performed at tube voltages of 40 and 70 kV, a tube current of 0.50 mA, and an X-ray exposure time of 5.0 s. MER images with threefold magnification were obtained using the FPD with a pixel size of 48×48 µm2, and the shifting dimensions of the imaged object in the horizontal and vertical directions ranged from 48 to 192 µm. At a shifting distance ranging from 48 to 144 µm, the spatial resolutions in the horizontal and vertical directions measured with a lead test chart were both 50 µm. In the MER of nonliving animals, we obtained high-contrast embossed images of fine bones, gadolinium oxide particles in blood vessels, and iodine-based microspheres in coronary arteries of approximately 100 µm diameter.

  9. Digital computer processing of X-ray photos

    NASA Technical Reports Server (NTRS)

    Nathan, R.; Selzer, R. H.

    1967-01-01

    Digital computers correct various distortions in medical and biological photographs. One of the principal methods of computer enhancement involves the use of a two-dimensional digital filter to modify the frequency spectrum of the picture. Another computer processing method is image subtraction.

  10. Practical Considerations In Digital Cardiac Angiography

    NASA Astrophysics Data System (ADS)

    Neeley, J. P.; Vannier, M. W.; Gutierrez, F. R.; Von Behren, P. L.

    1983-05-01

    Digital fluoroscopic image acquisition, processing and storage for ventriculography, coronary artery and bypass graft imaging involves many practical considerations. Issues of sufficiency in terms of spatial, temporal, gray scale resolution and intravascular contrast sensitivity arise when 35mm cineradiographic film acquisition is replaced by digital fluoroscopy as the primary imaging modality. We have qualitatively and quantitatively evaluated and compared digital fluoroscopic and cineradiographic systems for cardiovascular image acquisition, storage and display in the cardiac catheterization laboratory. A digital fluoroscopic system (Siemens Digitron I) was evaluated and compared favorably to 35mm cineradiography in temporal resolution. Spatial resolution of the digital system was poorer, but contrast sensitivity (with digital subtraction) far exceeded the capabilities of cineradiography. As further modifications are made to adapt digital systems to the cardiac catheterization laboratory, complete replacement of 35mm cineradiography by digital vascular imaging systems is likely in the near future.

  11. Digital Longitudinal Tomosynthesis

    NASA Astrophysics Data System (ADS)

    Rimkus, Daniel Steven

    1985-12-01

    The purpose of this dissertation was to investigate the clinical utility of digital longitudinal tomosynthesis in radiology. By acquiring a finite group of digital images during a longitudinal tomographic exposure, and processing these images, tomographic planes, other than the fulcrum plane, can be reconstructed. This process is now termed "tomosynthesis". A prototype system utilizing this technique was developed. Both phantom and patient studies were done with this system. The phantom studies were evaluated by subjective, visual criterion and by quantitative analysis of edge sharpness and noise in the reconstructions. Two groups of patients and one volunteer were studied. The first patient group consisted of 8 patients undergoing intravenous urography (IVU). These patients had digital tomography and film tomography of the abdomen. The second patient group consisted of 4 patients with lung cancer admitted to the hospital for laser resection of endobronchial tumor. These patients had mediastinal digital tomograms to evaluate the trachea and mainstem bronchi. The knee of one volunteer was imaged by film tomography and digital tomography. The results of the phantom studies showed that the digital reconstructions accurately produced images of the desired planes. The edge sharpness of the reconstructions approached that of the acquired images. Adequate reconstructions were achieved with as few as 5 images acquired during the exposure, with the quality of the reconstructions improving as the number of images acquired increased. The IVU patients' digital studies had less contrast and spatial resolution than the film tomograms. The single renal lesion visible on the film tomograms was also visible in the digital images. The digital mediastinal studies were felt by several radiologists to be superior to a standard chest xray in evaluating the airways. The digital images of the volunteer's knee showed many of the same anatomic features as the film tomogram, but the digital

  12. [Intravenous and subcutaneous immunoglobulin therapy].

    PubMed

    Thon, Vojtěch

    2013-07-01

    Patients with agammaglobulinaemia and hypogammaglobulinaemia require immunoglobulin G (IgG) replacement therapy to prevent serious infections. Since the 1950s, therapy with human immune globulin products has been the standard of treatment. Currently, the most common routes of administration of IgG replacement therapy are intravenous (IVIG) or subcutaneous (SCIG). The home therapy may improve the quality of life in patients who require lifelong IgG replacement. The -anti-IgA antibody test identifies the patients with the risk of anaphylactoid reactions in IVIG replacement. The SCIG delivery may be used in patients with anti-IgA antibodies and previous systemic reactions to IVIG. PMID:23964967

  13. Hypersensitivity from intravenous iron products.

    PubMed

    Bircher, Andreas J; Auerbach, Michael

    2014-08-01

    In the last several years, intravenous therapy with iron products has been more widely used. Although it has been a standard procedure in dialysis-associated anemia since the early 1990s, its use is expanding to a host of conditions associated with iron deficiency, especially young women with heavy uterine bleeding and pregnancy. Free iron is associated with unacceptable high toxicity inducing severe, hemodynamically significant symptoms. Subsequently, formulations that contain the iron as an iron carbohydrate nanoparticle have been designed. With newer formulations, including low-molecular-weight iron dextran, iron sucrose, ferric gluconate, ferumoxytol, iron isomaltoside, and ferric carboxymaltose, serious adverse events are rare. PMID:25017687

  14. Sky background subtraction with fiber-fed spectrographs

    NASA Astrophysics Data System (ADS)

    Puech, M.; Rodrigues, M.; Yang, Y.; Flores, H.; Royer, F.; Disseau, K.; Gonçalves, T.; Hammer, F.; Cirasuolo, M.; Evans, C. J.; Li Causi, G.; Maiolino, R.; Melo, C.

    2014-08-01

    Fiber-fed spectrographs can now have throughputs equivalent to slit spectrographs. However, the sky subtraction accuracy that can be reached on such instruments has often been pinpointed as one of their major issues, in relation to difficulties in scattered light and flat-field corrections or throughput losses associated with fibers. Using technical time observations with FLAMES-GIRAFFE, two observing techniques, namely dual staring and cross beam switching modes, were tested and the resulting sky subtraction accuracy reached in both cases was quantified. Results indicate that an accuracy of 0.6% on the sky subtraction can be reached, provided that the cross beam switching mode is used. This is very encouraging regarding the detection of very faint sources with future fiber-fed spectrographs such as VLT/MOONS or E-ELT/MOSAIC.

  15. Proposed smart integrated-optical preprocessor using holographic subtraction

    NASA Technical Reports Server (NTRS)

    Verber, C. M.; Vahey, D. W.

    1979-01-01

    The paper presents a proposed integrated-optical preprocessor with a holographic subtraction. It is based on an optical analog of a set of N analog voltages formed by passing an optical plane wave, confined in an electrooptic waveguide, under a set of N electrodes to which the voltages are applied; in the limit in which diffraction is ignored, the wavefront of the emerging guided wave will have superimposed upon it N discrete phase shifts. Processors which operate upon voltages encoded in this manner are being fabricated; they include a comparator in which incoming data are compared to a holographic record of the optical analog of a reference set, and a 'smart' system based upon holographic self-subtraction, in which the processor can independently adapt to changes in background information. The preprocessor operation is described in the screening, identification, and the self-subtraction modes, and implementation of devices in an integrated optical configuration is discussed.

  16. Pancreatic enzyme secretion during intravenous fat infusion.

    PubMed

    Burns, G P; Stein, T A

    1987-01-01

    The nutritional support of patients with pancreatic and high gastrointestinal fistulas and severe pancreatitis frequently involves intravenous fat infusion. There are conflicting reports on the effect of intravenous fat on pancreatic exocrine secretion. In 10 dogs with chronic pancreatic fistulas, pancreatic juice was collected during secretin (n = 10) or secretin + cholecystokinin (n = 4) stimulation, with and without intravenous fat infusion (5 g/hr). The hormonal-stimulated secretion of lipase, amylase, trypsin, total protein, bicarbonate, and water was unchanged during fat infusion. This study supports the use of intravenous fat as a nutritional source when it is desirable to avoid stimulation of the pancreas. PMID:2434670

  17. A Convenient Method for Measuring Blood Ascorbate Concentrations in Patients Receiving High-Dose Intravenous Ascorbate

    PubMed Central

    Ma, Yan; Sullivan, Garrett G; Schrick, Elizabeth; Choi, In-Young; He, Zhuoya; Lierman, JoAnn; Lee, Phil; Drisko, Jeanne A; Chen, Qi

    2013-01-01

    Objective A simple method of using fingerstick blood glucose monitors (FSBG) to estimate blood ascorbate values after high-dose intravenous (IV) ascorbate infusion is evaluated as a substitution for HPLC measurement. Methods In 33 participants, readings from FSBG were taken before and after IV ascorbate infusions at various time points, with the post-infusion FSBG readings subtracted by the baseline glucose readings. The results of the subtractions (AAFSBG) were correlated with ascorbate concentrations detected by HPLC (AAHPLC). Results A linear regression was found between ascorbate concentrations detected by the fingersitck method (AAFSBG) and by HPLC (AAHPLC). The linear correlations were identical in healthy subjects, diabetic subjects and cancer patients. ANOVA analysis obtained an AAFSBG/AAHPLC ratio of 0.90, with 90% confidence interval of (0.69, 1.20). The corrections of AAFSBG improved similarity to AAHPLC, but did not significantly differ from the un-corrected values. Conclusion The FSBG method can be used as an approximate estimation of high blood ascorbate concentration after IV ascorbate (>50 mg/dL, or 2.8 mM) without correction. However this measurement is not accurate in detecting lower or baseline blood ascorbate. It is also important to highlight that in regard to glucose monitoring, FSBG readings will be erroneously elevated following intravenous ascorbate use and insulin should not be administered to patients based on these readings. PMID:23885992

  18. Isolation of ultrasonic scattering by wavefield baseline subtraction

    NASA Astrophysics Data System (ADS)

    Dawson, Alexander J.; Michaels, Jennifer E.; Michaels, Thomas E.

    2016-03-01

    Wavefield imaging generally refers to the measurement of signals over a two-dimensional rectilinear grid that originate from a spatially fixed source. Subtraction of such wavefields is investigated as a means of separating scattered signals from the total wavefield; that is, baseline wavefield data acquired from a defect-free specimen are subtracted from analogous data acquired after introduction of a defect. The wavefields considered here are generated by a 5 MHz angle-beam probe and measured over an area of the accessible specimen surface using a laser vibrometer. The primary challenge in isolating the scattered waves is imperfect temporal and spatial alignment of the two wavefields. Two methods for aligning the wavefields in space and time prior to performing baseline subtraction are presented and their efficacy is evaluated using data acquired before and after introducing notches that originate from a through-hole. Although perfect baseline subtraction is not achieved, the improvement in performance after alignment using either method allows for scattered waves from small defects to be separated and visualized, even when their amplitudes are much smaller than those of the incident waves.

  19. Genomic subtraction for cloning DNA corresponding to deletion mutations.

    PubMed Central

    Straus, D; Ausubel, F M

    1990-01-01

    We have developed a technique, called genomic subtraction, for isolating the DNA that is absent in deletion mutants. The method removes from wild-type DNA the sequences that are present in both the wild-type and the deletion mutant genomes. The DNA that corresponds to the deleted region remains. Enrichment for the deleted sequences is achieved by allowing a mixture of denatured wild-type and biotinylated mutant DNA to reassociate. After reassociation, the biotinylated sequences are removed by binding to avidin-coated beads. This subtraction process is then repeated several times. In each cycle we hybridize the unbound wild-type DNA from the previous round with fresh biotinylated deletion mutant DNA. The unbound DNA from the final cycle is ligated to adaptors and amplified by using one strand of the adaptor as a primer in the polymerase chain reaction. The amplified sequences can then be used to probe a genomic library. We applied genomic subtraction to a yeast strain that has a 5-kilobase deletion, corresponding to 1/4000th of the genome. In the experiment reported here, three rounds of subtraction were sufficient to accurately identify genomic clones containing sequences that are missing in the deletion mutant. We discuss the limitations and some potential applications of the method. Images PMID:2408039

  20. On The Equivalence of Soft and Zero-Bin Subtractions

    SciTech Connect

    Thomas Mehen; Ahmad Idilbi

    2007-06-01

    Zero-bin subtractions are required to avoid double counting soft contributions in collinear loop integrals in Soft-Collinear Effective Theory (SCET). In traditional approaches to factorization, double counting is avoided by dividing jet functions by matrix elements of soft Wilson lines. In this paper, we compare the two approaches to double counting, studying the quark form factor and deep inelastic scattering (DIS) as x{sub B} to 1 as examples. We explain how the zero-bin subtractions in SCET are required to reproduce the well-established factorization theorem for DIS as x{sub B} to 1. We study one-loop virtual contributions to the quark form factor and real gluon emission diagrams in DIS. The two approaches to double counting are equivalent if dimensional regularization (DR) is used to regulate infrared (IR) divergences. We discuss in detail ambiguities in the calculation of one-loop scaleless integrals in DR in SCET and perturbative QCD. We also demonstrate a nontrivial check of the equivalence of the zero-bin subtraction and the soft Wilson line subtraction in the virtual two-loop Abelian contributions to the quark form factor.

  1. "Abuelita" Epistemologies: Counteracting Subtractive Schools in American Education

    ERIC Educational Resources Information Center

    Gonzales, Sandra M.

    2015-01-01

    This autoethnographic inquiry examines the intersection of elder epistemology and subtractive education, exploring how one "abuelita" countered her granddaughter's divestment of Mexican-ness. I demonstrate how the grandmother used "abuelita" epistemologies to navigate this tension and resist the assimilative pressures felt…

  2. Teaching Addition and Subtraction Facts: A Chinese Perspective.

    ERIC Educational Resources Information Center

    Sun, Wei; Zhang, Joanne Y.

    2001-01-01

    Presents an issue that arises in every country: How can teachers best help children master basic addition and subtraction facts? Discusses how this is handled in China and highlights the impact that language has on how children think about numbers. (KHR)

  3. Adding and Subtracting Vectors: The Problem with the Arrow Representation

    ERIC Educational Resources Information Center

    Heckler, Andrew F.; Scaife, Thomas M.

    2015-01-01

    A small number of studies have investigated student understanding of vector addition and subtraction in generic or introductory physics contexts, but in almost all cases the questions posed were in the vector arrow representation. In a series of experiments involving over 1000 students and several semesters, we investigated student understanding…

  4. Identifying and Remediating the Subtraction Errors of Learning Disabled Adolescents.

    ERIC Educational Resources Information Center

    Skrtic, Thomas M.; And Others

    1983-01-01

    An example is provided of remediation activities for learning disabled adolescents having a specific computation difficulty with place value and the subtraction with regrouping algorhythm. A seven-day remediation procedure, which may be used with the other basic operations, fades from the concrete to the symbolic mode. (CL)

  5. Symmetric point quartic gluon vertex and momentum subtraction

    NASA Astrophysics Data System (ADS)

    Gracey, J. A.

    2014-07-01

    We compute the full one loop correction to the quartic vertex of QCD at the fully symmetric point. This allows us to define a new momentum subtraction (MOM) scheme in the class of schemes introduced by Celmaster and Gonsalves. Hence using properties of the renormalization group equation, the two loop renormalization group functions for this scheme are given.

  6. Addition and Subtraction by Students with Down Syndrome

    ERIC Educational Resources Information Center

    Herrera, Aurelia Noda; Bruno, Alicia; Gonzalez, Carina; Moreno, Lorenzo; Sanabria, Hilda

    2011-01-01

    We present a research report on addition and subtraction conducted with Down syndrome students between the ages of 12 and 31. We interviewed a group of students with Down syndrome who executed algorithms and solved problems using specific materials and paper and pencil. The results show that students with Down syndrome progress through the same…

  7. Children's Understanding of the Relationship between Addition and Subtraction

    ERIC Educational Resources Information Center

    Gilmore, Camilla K.; Spelke, Elizabeth S.

    2008-01-01

    In learning mathematics, children must master fundamental logical relationships, including the inverse relationship between addition and subtraction. At the start of elementary school, children lack generalized understanding of this relationship in the context of exact arithmetic problems: they fail to judge, for example, that 12 + 9 - 9 yields…

  8. Energy sources for intravenous nutrition

    PubMed Central

    Rowlands, B J

    1987-01-01

    Controversy exists concerning the appropriate use of carbohydrate solutions and fat emulsions as energy sources in intravenous nutritional regimens. Current evidence suggests that glucose is the carbohydrate energy source of choice and that when infused with appropriate quantities of protein it provides cheap and effective nutritional support in the majority of patients and clinical circumstances. During glucose infusion, blood glucose and acid-base balance should be closely monitored and, when indicated, exogenous insulin should be added to the regimen to combat hyperglycaemia and improve protein anabolism. Fat emulsions, although expensive, may justifiably be used in patients with moderate or severe stress to provide up to 50% of non-protein energy, especially in circumstances where attempts to satisfy energy requirements exclusively with glucose would impose an additional metabolic stress. PMID:3109093

  9. A prototype space flight intravenous injection system

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.

    1985-01-01

    Medical emergencies, especially those resulting from accidents, frequently require the administration of intravenous fluids to replace lost body liquids. The development of a prototype space flight intravenous injection system is presented. The definition of requirements, injectable concentrates development, water polisher, reconstitution hardware development, administration hardware development, and prototype fabrication and testing are discussed.

  10. Subtraction method for intravital two-photon microscopy: intraparenchymal imaging and quantification of extravasation in mouse brain cortex.

    PubMed

    Vérant, Pascale; Serduc, Raphaël; van der Sanden, Boudewijn; Chantal, Rémy; Ricard, Clément; Coles, Jonathan A; Vial, Jean-Claude

    2008-01-01

    Brain pathologies, including stroke and tumors, are associated with a variable degree of breakdown of the blood-brain barrier (BBB), which can usefully be studied in animal models. We describe a new optical technique for quantifying extravasation in the cortex of the living mouse and for imaging intraparenchymal tissue. Leakiness of the BBB was induced by microbeam x-irradiation. Two fluorescent dyes were simultaneously infused intravenously, one of high molecular weight (fluorescein-labeled dextran, 70 kDa, green fluorescence) and one of low molecular weight (sulforhodamine B, 559 Da, red fluorescence). A two-photon microscope, directed through a cranial window, obtained separate images of the two dyes in the cortex. The gains of the two channels were adjusted so that the signals coming from within the vessels were equal. Subtraction of the image of the fluorescein-dextran from that of the sulforhodamine B gave images in which the vasculature was invisible and the sulforhodamine B in the parenchyma could be imaged with high resolution. Algorithms are presented for rapidly quantifying the extravasation without the need for shape recognition and for calculating the permeability of the BBB. Sulforhodamine B labeled certain intraparenchymal cells; these cells, and other details, were best observed using the subtraction method. PMID:18315351

  11. Efficacy of sealing proximal early active lesions: an 18-month clinical study evaluated by conventional and subtraction radiography.

    PubMed

    Martignon, S; Ekstrand, K R; Ellwood, R

    2006-01-01

    This study assessed the efficacy of sealing proximal lesions on adult patients using a split-mouth design. Eighty-two 15- to 39-year-olds from the Dental Faculties in Copenhagen and Bogotá participated, each having 2 or more proximal lesions in the following radiographic stages: (1) lesion restricted to the outer half of enamel; (2) lesion from the inner half of enamel including the enamel dentine junction, and (3) lesion restricted to the outer third of dentine. Standardized geometrically aligned baseline and follow-up radiographs were obtained. One randomly selected lesion (test) in each patient was sealed with 1 of 2 resins. The patients were instructed to floss all the proximal lesions 3 times per week. The baseline to 18 months difference in caries lesion progression status was assessed using 3 methods: (1) radiographs were independently assessed visually; (2) radiographs were read in pairs, and (3) using subtraction radiography of digitized images. A total of 72 subjects finished the study (12.2% dropout). The compliance concerning flossing was poor (15%). For the repeated examinations kappa was 0.84 for the visual examination, 0.44 for the paired readings and 0.84 for the subtraction examination. Two test lesions and 1 control lesion were restored. For the independent radiograph assessment method 10 and 26% progressed in the test and control group, respectively (p > 0.05); with the paired radiograph method the corresponding data were 22% in the test and 47% in the control groups (p < 0.01). By subtraction radiography 44% of the test group and 84% of the control were judged to have progressed (p < 0.001). The sealing technique was superior to instructing patients to floss, and subtraction radiography appeared to be the most sensitive method for assessing lesion progression. PMID:16946605

  12. Robust Background Subtraction with Foreground Validation for Urban Traffic Video

    SciTech Connect

    Cheung, S S; Kamath, C

    2004-01-15

    Identifying moving objects in a video sequence is a fundamental and critical task in many computer-vision applications. Background subtraction techniques are commonly used to separate foreground moving objects from the background. Most background subtraction techniques assume a single rate of adaptation, which is inadequate for complex scenes such as a traffic intersection where objects are moving at different and varying speeds. In this paper, we propose a foreground validation algorithm that first builds a foreground mask using a slow-adapting Kalman filter, and then validates individual foreground pixels by a simple moving object model, built using both the foreground and background statistics as well as the frame difference. Ground-truth experiments with urban traffic sequences show that our proposed algorithm significantly improves upon results using only Kalman filter or frame-differencing, and outperforms other techniques based on mixture of Gaussians, median filter, and approximated media filter.

  13. Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

    PubMed Central

    Hyun, Seung-Jae; Kim, Yongjung J; Rhim, Seung-Chul

    2013-01-01

    In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The long-term overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided. PMID:24340276

  14. Multivariate Spatial Condition Mapping Using Subtractive Fuzzy Cluster Means

    PubMed Central

    Sabit, Hakilo; Al-Anbuky, Adnan

    2014-01-01

    Wireless sensor networks are usually deployed for monitoring given physical phenomena taking place in a specific space and over a specific duration of time. The spatio-temporal distribution of these phenomena often correlates to certain physical events. To appropriately characterise these events-phenomena relationships over a given space for a given time frame, we require continuous monitoring of the conditions. WSNs are perfectly suited for these tasks, due to their inherent robustness. This paper presents a subtractive fuzzy cluster means algorithm and its application in data stream mining for wireless sensor systems over a cloud-computing-like architecture, which we call sensor cloud data stream mining. Benchmarking on standard mining algorithms, the k-means and the FCM algorithms, we have demonstrated that the subtractive fuzzy cluster means model can perform high quality distributed data stream mining tasks comparable to centralised data stream mining. PMID:25313495

  15. ZAP - enhanced PCA sky subtraction for integral field spectroscopy

    NASA Astrophysics Data System (ADS)

    Soto, Kurt T.; Lilly, Simon J.; Bacon, Roland; Richard, Johan; Conseil, Simon

    2016-05-01

    We introduce Zurich Atmosphere Purge (ZAP), an approach to sky subtraction based on principal component analysis (PCA) that we have developed for the Multi Unit Spectrographic Explorer (MUSE) integral field spectrograph. ZAP employs filtering and data segmentation to enhance the inherent capabilities of PCA for sky subtraction. Extensive testing shows that ZAP reduces sky emission residuals while robustly preserving the flux and line shapes of astronomical sources. The method works in a variety of observational situations from sparse fields with a low density of sources to filled fields in which the target source fills the field of view. With the inclusion of both of these situations, the method is generally applicable to many different science cases and should also be useful for other instrumentation. ZAP is available for download at http://muse-vlt.eu/science/tools.

  16. Self-mixing differential vibrometer based on electronic channel subtraction.

    PubMed

    Donati, Silvano; Norgia, Michele; Giuliani, Guido

    2006-10-01

    An instrument for noncontact measurement of differential vibrations is developed, based on the self-mixing interferometer. As no reference arm is available in the self-mixing configuration, the differential mode is obtained by electronic subtraction of signals from two (nominally equal) vibrometer channels, taking advantage that channels are servo stabilized and thus insensitive to speckle and other sources of amplitude fluctuation. We show that electronic subtraction is nearly as effective as field superposition. Common-mode suppression is 25-30 dB, the dynamic range (amplitude) is in excess of 100 microm, and the minimum measurable (differential) amplitude is 20 nm on a B = 10 kHz bandwidth. The instrument has been used to measure vibrations of two metal samples kept in contact, revealing the hysteresis cycle in the microslip and gross-slip regimes, which are of interest in the study of friction induced vibration damping of gas turbine blades for aircraft applications. PMID:16983412

  17. Noise Reduction using Frequency Sub-Band Adaptive Spectral Subtraction

    NASA Technical Reports Server (NTRS)

    Kozel, David

    2000-01-01

    A frequency sub-band based adaptive spectral subtraction algorithm is developed to remove noise from noise-corrupted speech signals. A single microphone is used to obtain both the noise-corrupted speech and the estimate of the statistics of the noise. The statistics of the noise are estimated during time frames that do not contain speech. These statistics are used to determine if future time frames contain speech. During speech time frames, the algorithm determines which frequency sub-bands contain useful speech information and which frequency sub-bands contain only noise. The frequency sub-bands, which contain only noise, are subtracted off at a larger proportion so the noise does not compete with the speech information. Simulation results are presented.

  18. Multivariate spatial condition mapping using subtractive fuzzy cluster means.

    PubMed

    Sabit, Hakilo; Al-Anbuky, Adnan

    2014-01-01

    Wireless sensor networks are usually deployed for monitoring given physical phenomena taking place in a specific space and over a specific duration of time. The spatio-temporal distribution of these phenomena often correlates to certain physical events. To appropriately characterise these events-phenomena relationships over a given space for a given time frame, we require continuous monitoring of the conditions. WSNs are perfectly suited for these tasks, due to their inherent robustness. This paper presents a subtractive fuzzy cluster means algorithm and its application in data stream mining for wireless sensor systems over a cloud-computing-like architecture, which we call sensor cloud data stream mining. Benchmarking on standard mining algorithms, the k-means and the FCM algorithms, we have demonstrated that the subtractive fuzzy cluster means model can perform high quality distributed data stream mining tasks comparable to centralised data stream mining. PMID:25313495

  19. Disposition of intravenous radioactive acyclovir

    SciTech Connect

    de Miranda, P.; Good, S.S.; Laskin, O.L.; Krasny, H.C.; Connor, J.D.; Lietman, P.S.

    1981-11-01

    The kinetic and metabolic disposition of (8-14C)acyclovir (ACV) was investigated in five subjects with advanced malignancy. The drug was administered by 1-hr intravenous infusion at doses of 0.5 and 2.5 mg/kg. Plasma and blood radioactivity-time, and plasma concentration-time data were defined by a two-compartment open kinetic model. There was nearly equivalent distribution of radioactivity in blood and plasma. The overall mean plasma half-life and total body clearance +/- SD of ACV were 2.1 +/- 0.5 hr and 297 +/- 53 ml/min/1.73 m2. Binding of ACV to plasma proteins was 15.4 +/- 4.4%. Most of the radioactive dose excreted was recovered in the urine (71% to 99%) with less than 2% excretion in the feces and only trace amounts in the expired Co2. Analyses by reverse-phase high-performance liquid chromatography indicated that 9-(carboxymethoxymethyl)guanine was the only significant urinary metabolite of ACV, accounting for 8.5% to 14.1% of the dose. A minor metabolite (less than 0.2% of dose) had the retention time of 8-hydroxy-9-((2-hydroxyethoxy)methyl)guanine. Unchanged urinary ACV ranged from 62% to 91% of the dose. There was no indication of ACV cleavage to guanine. Renal clearance of ACV was approximately three times the corresponding creatinine clearances.

  20. Intravenous thrombolytics for ischemic stroke.

    PubMed

    Barreto, Andrew D

    2011-07-01

    For many decades, intravenous (IV) thrombolytics have been delivered to treat acute thrombosis. Although these medications were originally effective for coronary thrombosis, their mechanisms have proven beneficial for many other disease processes, including ischemic stroke. Treatment paradigms for acute ischemic stroke have largely followed those of cardiology. Specifically, the aim has been to recanalize the occluded artery and to restore perfusion to the brain that remains salvageable. To that end, rapid clot lysis was sought using thrombolytic medicines already proven effective in the coronary arteries. IV-thrombolysis for ischemic stroke began its widespread adoption in the late 1990s after the publication of the National Institute of Neurological Disorders and Stroke study. Since that time, other promising IV-thrombolytics have been developed and tested in human trials, but as of yet, none have been proven better than a placebo. Adjunctive treatments are also being evaluated. The challenge remains balancing reperfusion and salvaging brain tissue with the potential risks of brain hemorrhage. PMID:21638138

  1. Number Words in Young Children's Conceptual and Procedural Knowledge of Addition, Subtraction and Inversion

    ERIC Educational Resources Information Center

    Canobi, Katherine H.; Bethune, Narelle E.

    2008-01-01

    Three studies addressed children's arithmetic. First, 50 3- to 5-year-olds judged physical demonstrations of addition, subtraction and inversion, with and without number words. Second, 20 3- to 4-year-olds made equivalence judgments of additions and subtractions. Third, 60 4- to 6-year-olds solved addition, subtraction and inversion problems that…

  2. Subtraction of Positive and Negative Numbers: The Difference and Completion Approaches with Chips

    ERIC Educational Resources Information Center

    Flores, Alfinio

    2008-01-01

    Diverse contexts such as "take away," comparison," and "completion" give rise to subtraction problems. The take-away interpretation of subtraction has been explored using two-colored chips to help students understand addition and subtraction of integers. This article illustrates how the difference and completion (or missing addend) interpretations…

  3. Subtractive Renormalization Group Invariance: Pionless EFT at NLO

    SciTech Connect

    Timoteo, Varese S.; Szpigel, Sergio; Duraes, Francisco O.

    2010-11-12

    We show some results concerning the renormalization group (RG) invariance of the nucleon-nucleon (NN) interaction in pionless effective field theory at next-to-leading order (NLO), using a non-relativistic Callan-Symanzik equation (NRCS) for the driving term of the Lippmann-Schwinger (LS) equation with three recursive subtractions. The phase-shifts obtained for the RG evolved potential are same as those for the original potential, apart from relative differences of order 10{sup -15}.

  4. Application of spectral subtraction method on enhancement of electrolarynx speech.

    PubMed

    Liu, Hanjun; Zhao, Qin; Wan, Mingxi; Wang, Supin

    2006-07-01

    Although electrolarynx (EL) serves as an important method of phonation for the laryngectomees, the resulting speech is of poor intelligibility due to the presence of a steady background noise caused by the instrument, even worse in the case of additive noise. This paper investigates the problem of EL speech enhancement by taking into account the frequency-domain masking properties of the human auditory system. One approach is incorporating an auditory masking threshold (AMT) for parametric adaptation in a subtractive-type enhancement process. The other is the supplementary AMT (SAMT) algorithm, which applies a cross-correlation spectral subtraction (CCSS) approach as a post-processing scheme to enhancing EL speech dealt with the AMT method. The performance of these two algorithms was evaluated as compared to the power spectral subtraction (PSS) algorithm. The best performance of EL speech enhancement was associated with the SAMT algorithm, followed by the AMT algorithm and the PSS algorithm. Acoustic and perceptual analyses indicated that the AMT and SAMT algorithms achieved the better performances of noise reduction and the enhanced EL speech was more pleasant to human listeners as compared to the PSS algorithm. PMID:16875235

  5. ROBUST TECHNIQUES FOR BACKGROUND SUBTRACTION IN URBAN TRAFFIC VIDEO

    SciTech Connect

    Kamath, C; Cheung, S S

    2003-10-28

    Identifying moving objects from a video sequence is a fundamental and critical task in many computer-vision applications. A common approach is to perform background subtraction, which identifies moving objects from the portion of a video frame that differs significantly from a background model. There are many challenges in developing a good background subtraction algorithm. First, it must be robust against changes in illumination. Second, it should avoid detecting non-stationary background objects such as swinging leaves, rain, snow, and shadow cast by moving objects. Finally, its internal background model should react quickly to changes in background such as starting and stopping of vehicles. In this paper, we compare various background subtraction algorithms for detecting moving vehicles and pedestrians in urban traffic video sequences. We consider approaches varying from simple techniques such as frame differencing and adaptive median filtering, to more sophisticated probabilistic modeling techniques. While complicated techniques often produce superior performance, our experiments show that simple techniques such as adaptive median filtering can produce good results with much lower computational complexity.

  6. Temporal subtraction contrast-enhanced dedicated breast CT

    NASA Astrophysics Data System (ADS)

    Gazi, Peymon M.; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M.

    2016-09-01

    The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0–16%), NCC (0–6%), NMI (0–13%) and TRE (0–34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was

  7. Temporal subtraction contrast-enhanced dedicated breast CT.

    PubMed

    Gazi, Peymon M; Aminololama-Shakeri, Shadi; Yang, Kai; Boone, John M

    2016-09-01

    The development of a framework of deformable image registration and segmentation for the purpose of temporal subtraction contrast-enhanced breast CT is described. An iterative histogram-based two-means clustering method was used for the segmentation. Dedicated breast CT images were segmented into background (air), adipose, fibroglandular and skin components. Fibroglandular tissue was classified as either normal or contrast-enhanced then divided into tiers for the purpose of categorizing degrees of contrast enhancement. A variant of the Demons deformable registration algorithm, intensity difference adaptive Demons (IDAD), was developed to correct for the large deformation forces that stemmed from contrast enhancement. In this application, the accuracy of the proposed method was evaluated in both mathematically-simulated and physically-acquired phantom images. Clinical usage and accuracy of the temporal subtraction framework was demonstrated using contrast-enhanced breast CT datasets from five patients. Registration performance was quantified using normalized cross correlation (NCC), symmetric uncertainty coefficient, normalized mutual information (NMI), mean square error (MSE) and target registration error (TRE). The proposed method outperformed conventional affine and other Demons variations in contrast enhanced breast CT image registration. In simulation studies, IDAD exhibited improvement in MSE (0-16%), NCC (0-6%), NMI (0-13%) and TRE (0-34%) compared to the conventional Demons approaches, depending on the size and intensity of the enhancing lesion. As lesion size and contrast enhancement levels increased, so did the improvement. The drop in the correlation between the pre- and post-contrast images for the largest enhancement levels in phantom studies is less than 1.2% (150 Hounsfield units). Registration error, measured by TRE, shows only submillimeter mismatches between the concordant anatomical target points in all patient studies. The algorithm was

  8. An improved dark-object subtraction technique for atmospheric scattering correction of multispectral data

    USGS Publications Warehouse

    Chavez, P.S., Jr.

    1988-01-01

    Digital analysis of remotely sensed data has become an important component of many earth-science studies. These data are often processed through a set of preprocessing or "clean-up" routines that includes a correction for atmospheric scattering, often called haze. Various methods to correct or remove the additive haze component have been developed, including the widely used dark-object subtraction technique. A problem with most of these methods is that the haze values for each spectral band are selected independently. This can create problems because atmospheric scattering is highly wavelength-dependent in the visible part of the electromagnetic spectrum and the scattering values are correlated with each other. Therefore, multispectral data such as from the Landsat Thematic Mapper and Multispectral Scanner must be corrected with haze values that are spectral band dependent. An improved dark-object subtraction technique is demonstrated that allows the user to select a relative atmospheric scattering model to predict the haze values for all the spectral bands from a selected starting band haze value. The improved method normalizes the predicted haze values for the different gain and offset parameters used by the imaging system. Examples of haze value differences between the old and improved methods for Thematic Mapper Bands 1, 2, 3, 4, 5, and 7 are 40.0, 13.0, 12.0, 8.0, 5.0, and 2.0 vs. 40.0, 13.2, 8.9, 4.9, 16.7, and 3.3, respectively, using a relative scattering model of a clear atmosphere. In one Landsat multispectral scanner image the haze value differences for Bands 4, 5, 6, and 7 were 30.0, 50.0, 50.0, and 40.0 for the old method vs. 30.0, 34.4, 43.6, and 6.4 for the new method using a relative scattering model of a hazy atmosphere. ?? 1988.

  9. Improvement of detection in computed radiography by new single-exposure dual-energy subtraction

    NASA Astrophysics Data System (ADS)

    Itoh, Wataru; Shimura, Kazuo; Nakajima, Nobuyoshi; Ishida, Masamitsu; Kato, Hisatoyo

    1992-06-01

    It is reported that the use of the dual-energy subtraction method enhances the abnormal shadow detection capability. However, as the subtracted image is significantly inferior to the original in signal-to-noise ratio (SNR), the x ray dosage normally used for chest x rays has not yielded subtracted images with adequate SNRs. Under these circumstances, we have concentrated on the fact that there is a correlation between the noise contents of bone and soft- tissue subtracted images although there is no correlation between the signal contents of these images. We now propose an algorithm that improves SNRs of subtraction images by reducing the noise only.

  10. Anatomical noise in contrast-enhanced digital mammography. Part I. Single-energy imaging

    SciTech Connect

    Hill, Melissa L.; Yaffe, Martin J.; Mainprize, James G.; Carton, Ann-Katherine; Muller, Serge; Ebrahimi, Mehran; Jong, Roberta A.; Dromain, Clarisse

    2013-05-15

    Purpose: The use of an intravenously injected iodinated contrast agent could help increase the sensitivity of digital mammography by adding information on tumor angiogenesis. Two approaches have been made for clinical implementation of contrast-enhanced digital mammography (CEDM), namely, single-energy (SE) and dual-energy (DE) imaging. In each technique, pairs of mammograms are acquired, which are then subtracted with the intent to cancel the appearance of healthy breast tissue to permit sensitive detection and specific characterization of lesions. Patterns of contrast agent uptake in the healthy parenchyma, and uncanceled signal from background tissue create a 'clutter' that can mask or mimic an enhancing lesion. This type of 'anatomical noise' is often the limiting factor in lesion detection tasks, and thus, noise quantification may be useful for cascaded systems analysis of CEDM and for phantom development. In this work, the authors characterize the anatomical noise in CEDM clinical images and the authors evaluate the influence of the x-ray energy used for acquisition, the presence of iodine in the breast, and the timing of imaging postcontrast administration on anatomical noise. The results are presented in a two-part report, with SE CEDM described here, and DE CEDM in Part II. Methods: A power law is used to model anatomical noise in CEDM images. The exponent, {beta}, which describes the anatomical structure, and the constant {alpha}, which represents the magnitude of the noise, are determined from Wiener spectra (WS) measurements on images. A total of 42 SE CEDM cases from two previous clinical pilot studies are assessed. The parameters {alpha} and {beta} are measured both from unprocessed images and from subtracted images. Results: Consistent results were found between the two SE CEDM pilot studies, where a significant decrease in {beta} from a value of approximately 3.1 in the unprocessed images to between about 1.1 and 1.8 in the subtracted images was

  11. Intravenous iron-containing products: EMA procrastination.

    PubMed

    2014-07-01

    A European reassessment has led to identical changes in the summaries of product characteristics (SPCs) for all intravenous iron-containing products: the risk of serious adverse effects is now highlighted, underlining the fact that intravenous iron-containing products should only be used when the benefits clearly outweigh the harms. Unfortunately, iron dextran still remains on the market despite a higher risk of hypersensitivity reactions than with iron sucrose. PMID:25162093

  12. Artifacts in digital coincidence timing.

    PubMed

    Moses, W W; Peng, Q

    2014-11-01

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator.All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the 'optimal' method. The purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization. PMID:25321885

  13. Artifacts in Digital Coincidence Timing

    PubMed Central

    Moses, W. W.; Peng, Q.

    2014-01-01

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator. All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e., the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the “optimal” method. The purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization. PMID:25321885

  14. Artifacts in digital coincidence timing

    NASA Astrophysics Data System (ADS)

    Moses, W. W.; Peng, Q.

    2014-11-01

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator. All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the ‘optimal’ method. The purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization.

  15. Artifacts in digital coincidence timing

    SciTech Connect

    Moses, W. W.; Peng, Q.

    2014-10-16

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into a time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator.All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the 'optimal' method. In conclusion, the purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization.

  16. Adding and subtracting vectors: The problem with the arrow representation

    NASA Astrophysics Data System (ADS)

    Heckler, Andrew F.; Scaife, Thomas M.

    2015-06-01

    A small number of studies have investigated student understanding of vector addition and subtraction in generic or introductory physics contexts, but in almost all cases the questions posed were in the vector arrow representation. In a series of experiments involving over 1000 students and several semesters, we investigated student understanding of vector addition and subtraction in both the arrow and algebraic notation (using i ^, j ^, k ^) in generic mathematical and physics contexts. First, we replicated a number of previous findings of student difficulties in the arrow format and discovered several additional difficulties, including the finding that different relative arrow orientations can prompt different solution paths and different kinds of mistakes, which suggests that students need to practice with a variety of relative orientations. Most importantly, we found that average performance in the i j k format was typically excellent and often much better than performance in the arrow format in either the generic or physics contexts. Further, while we find that the arrow format tends to prompt students to a more physically intuitive solution path, we also find that, when prompted, student solutions in the i j k format also display significant physical insights into the problem. We also find a hierarchy in correct answering between the two formats, with correct answering in the i j k format being more fundamental than for the arrow format. Overall, the results suggest that many student difficulties with these simple vector problems lie with the arrow representation itself. For instruction, these results imply that introducing the i j k notation (or some equivalent) with the arrow notation concurrently may be a very useful way to improve student performance as well as help students to learn physics concepts involving vector addition and subtraction.

  17. Skycorr: A general tool for spectroscopic sky subtraction

    NASA Astrophysics Data System (ADS)

    Noll, S.; Kausch, W.; Kimeswenger, S.; Barden, M.; Jones, A. M.; Modigliani, A.; Szyszka, C.; Taylor, J.

    2014-07-01

    Context. Airglow emission lines, which dominate the optical-to-near-infrared sky radiation, show strong, line-dependent variability on time scales from minutes to decades. Therefore, the subtraction of the sky background in the affected wavelength regime becomes a problem if plain-sky spectra have to be taken at a different time from the astronomical data. Aims: A solution of this problem is the physically motivated scaling of the airglow lines in the plain-sky data to fit the sky lines in the object spectrum. We have developed a corresponding instrument-independent approach based on one-dimensional spectra. Methods: Our code skycorr separates sky lines and sky/object continuum by an iterative approach involving a line finder and airglow line data. The sky lines, which mainly belong to OH and O2 bands, are grouped according to their expected variability. The line groups in the sky data are then scaled to fit the sky in the science data. Required pixel-specific weights for overlapping groups are taken from a comprehensive airglow model. Deviations in the wavelength calibration are corrected for by fitting Chebyshev polynomials and rebinning via asymmetric damped sinc kernels. The scaled sky lines and the sky continuum are subtracted separately. Results: ESO-VLT X-shooter data covering 2.5 h with a good time resolution were selected to illustrate the performance. Data taken six nights and about one year before were also used as reference sky data. The variation of the sky-subtraction quality as a function of time difference between the object and sky data depends on changes in the airglow intensity, atmospheric transparency, and instrument calibration. Except for short time intervals of a few minutes, the sky line residuals were between 2.1 and 5.5 times weaker than for sky subtraction without fitting. Additional tests showed that skycorr performs consistently better than the method of Davies (2007, MNRAS, 375, 1099) developed for ESO-VLT SINFONI data.

  18. Peripheral NN scattering from subtractive renormalization of chiral interactions

    SciTech Connect

    Batista, E. F.; Szpigel, S.; Timóteo, V. S.

    2014-11-11

    We apply five subtractions in the Lippman-Schwinger (LS) equation in order to perform a non-perturbative renormalization of chiral N3LO nucleon-nucleon interactions. Here we compute the phase shifts for the uncoupled peripheral waves at renormalization scales between 0.1 fm{sup −1} and 1 fm{sup −1}. In this range, the results are scale invariant and provide an overall good agreement with the Nijmegen partial wave analysis up to at least E{sub lab} = 150 MeV, with a cutoff at Λ = 30 fm{sup −1}.

  19. Background subtraction system for pulsed neutron logging of earth boreholes

    SciTech Connect

    Hertzog, R.C.

    1980-11-04

    The composition of an earth formation is investigated by repetitively irradiating the formation with bursts of fast neutrons and generating an inelastic energy spectrum from gamma ray counts detected during first time intervals which are contemporaneous with the bursts. A second energy spectrum is generated from gamma ray counts detected during second time intervals which immediately follow respective first time intervals. Gamma ray counts comprising the second spectrum are thereafter subtracted from the gamma ray counts comprising the inelastic spectrum to provide an inelastic energy spectrum with reduced background.

  20. WFPC2 photometry from subtraction of TinyTim PSFs

    NASA Technical Reports Server (NTRS)

    Remy, M.; Surdej, J.; Baggett, S.; Wiggs, M.

    1997-01-01

    Based upon the subtraction of TinyTim Point Spread Function (PSFs) from Principle Component Image (PC1) point-like objects, a method has been developed to determine the optimal values for the telescope jitter and the Z4 relative focus during calibration or science observations. Using these jitter and focus values, an optimal TinyTim PSF, computed over a resampled grid, is then iteratively fitted to the object, yielding an improvement in the PSF centering, more accurate photometric results and a better detection of underlying structures. Preliminary results seem to indicate that appropriate synthetic TinyTim PSFs perform as well as observed PSFs.

  1. Addition and subtraction by students with Down syndrome

    NASA Astrophysics Data System (ADS)

    Noda Herrera, Aurelia; Bruno, Alicia; González, Carina; Moreno, Lorenzo; Sanabria, Hilda

    2011-01-01

    We present a research report on addition and subtraction conducted with Down syndrome students between the ages of 12 and 31. We interviewed a group of students with Down syndrome who executed algorithms and solved problems using specific materials and paper and pencil. The results show that students with Down syndrome progress through the same procedural levels as those without disabilities though they have difficulties in reaching the most abstract level (numerical facts). The use of fingers or concrete representations (balls) appears as a fundamental process among these students. As for errors, these vary widely depending on the students, and can be attributed mostly to an incomplete knowledge of the decimal number system.

  2. Walking boosts your performance in making additions and subtractions

    PubMed Central

    Anelli, Filomena; Lugli, Luisa; Baroni, Giulia; Borghi, Anna M.; Nicoletti, Roberto

    2014-01-01

    Previous research demonstrates that the processing of spatial information and numerical magnitude are strictly interwoven. Recent studies also provide converging evidence that number processing is influenced by body movements. In the present study we further investigate this issue by focusing on whether and how motions experienced with the whole body can influence arithmetical calculations. We asked participants to make additions or subtractions while experiencing leftward and rightward motions. Data revealed the emergence of a congruency effect between the orientation inferred by the type of arithmetical calculations and the type of motions experienced along an horizontal axis. PMID:25566137

  3. Digital demodulator-correlator

    NASA Technical Reports Server (NTRS)

    Layland, J. W.; Martin, W. L.; Zygielbaum, A. I.; Goldstein, R. M.; Hubbard, W. P. (Inventor)

    1978-01-01

    An apparatus for demodulation and correlation of a code modulated 10 MHz signal is presented. The apparatus is comprised of a sample and hold analog-to-digital converter synchronized by a frequency coherent 40 MHz pulse to obtain four evenly spaced samples of each of the signal. Each sample is added or subtracted to or from one of four accumulators to or from the separate sums. The correlation functions are then computed. As a further feature of the invention, multipliers are each multiplied by a squarewave chopper signal having a period that is long relative to the period of the received signal to foreclose contamination of the received signal by leakage from either of the other two terms of the multipliers.

  4. Digital Libraries.

    ERIC Educational Resources Information Center

    Fox, Edward A.; Urs, Shalini R.

    2002-01-01

    Provides an overview of digital libraries research, practice, and literature. Highlights include new technologies; redefining roles; historical background; trends; creating digital content, including conversion; metadata; organizing digital resources; services; access; information retrieval; searching; natural language processing; visualization;…

  5. Ultra low radiation dose digital subtraction angiography (DSA) imaging using low rank constraint

    NASA Astrophysics Data System (ADS)

    Niu, Kai; Li, Yinsheng; Schafer, Sebastian; Royalty, Kevin; Wu, Yijing; Strother, Charles; Chen, Guang-Hong

    2015-03-01

    In this work we developed a novel denoising algorithm for DSA image series. This algorithm takes advantage of the low rank nature of the DSA image sequences to enable a dramatic reduction in radiation and/or contrast doses in DSA imaging. Both spatial and temporal regularizers were introduced in the optimization algorithm to further reduce noise. To validate the method, in vivo animal studies were conducted with a Siemens Artis Zee biplane system using different radiation dose levels and contrast concentrations. Both conventionally processed DSA images and the DSA images generated using the novel denoising method were compared using absolute noise standard deviation and the contrast to noise ratio (CNR). With the application of the novel denoising algorithm for DSA, image quality can be maintained with a radiation dose reduction by a factor of 20 and/or a factor of 2 reduction in contrast dose. Image processing is completed on a GPU within a second for a 10s DSA data acquisition.

  6. Carbon dioxide (CO2) digital subtraction angiography: 26-year experience at the University of Florida.

    PubMed

    Hawkins, I F; Caridi, J G

    1998-01-01

    Although the vascular system is presently being imaged by multiple high technology modalities, contrast angiography continues to be the gold standard; however, severe complications rarely occur. During the last 25 years (in over 1400 patients), CO2 has proven to be extremely safe (no allergy or renal failure). However, it is imperative to understand CO2's physical properties and potential dangers. Recently, CO2 is being routinely utilized not only because of safety, but for detection of minute amounts of bleeding, better collateral filling, and for most interventional procedures since unlimited volumes of CO2 can be injected between the catheter and guidewire. Presently, safe, reliable and "user-friendly" delivery systems are now commercially available. CO2 DSA images are now nearly comparable to iodinated contrast, and improvement in DSA images are evolving, including "stacking" software. PMID:9510571

  7. Iodine filter imaging system for subtraction angiography using synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Umetani, K.; Ueda, K.; Takeda, T.; Itai, Y.; Akisada, M.; Nakajima, T.

    1993-11-01

    A new type of real-time imaging system was developed for transvenous coronary angiography. A combination of an iodine filter and a single energy broad-bandwidth X-ray produces two-energy images for the iodine K-edge subtraction technique. X-ray images are sequentially converted to visible images by an X-ray image intensifier. By synchronizing the timing of the movement of the iodine filter into and out of the X-ray beam, two output images of the image intensifier are focused side by side on the photoconductive layer of a camera tube by an oscillating mirror. Both images are read out by electron beam scanning of a 1050-scanning-line video camera within a camera frame time of 66.7 ms. One hundred ninety two pairs of iodine-filtered and non-iodine-filtered images are stored in the frame memory at a rate of 15 pairs/s. In vivo subtracted images of coronary arteries in dogs were obtained in the form of motion pictures.

  8. Background Subtraction Based on Three-Dimensional Discrete Wavelet Transform

    PubMed Central

    Han, Guang; Wang, Jinkuan; Cai, Xi

    2016-01-01

    Background subtraction without a separate training phase has become a critical task, because a sufficiently long and clean training sequence is usually unavailable, and people generally thirst for immediate detection results from the first frame of a video. Without a training phase, we propose a background subtraction method based on three-dimensional (3D) discrete wavelet transform (DWT). Static backgrounds with few variations along the time axis are characterized by intensity temporal consistency in the 3D space-time domain and, hence, correspond to low-frequency components in the 3D frequency domain. Enlightened by this, we eliminate low-frequency components that correspond to static backgrounds using the 3D DWT in order to extract moving objects. Owing to the multiscale analysis property of the 3D DWT, the elimination of low-frequency components in sub-bands of the 3D DWT is equivalent to performing a pyramidal 3D filter. This 3D filter brings advantages to our method in reserving the inner parts of detected objects and reducing the ringing around object boundaries. Moreover, we make use of wavelet shrinkage to remove disturbance of intensity temporal consistency and introduce an adaptive threshold based on the entropy of the histogram to obtain optimal detection results. Experimental results show that our method works effectively in situations lacking training opportunities and outperforms several popular techniques. PMID:27043570

  9. Fast Image Subtraction Using Multi-cores and GPUs

    NASA Astrophysics Data System (ADS)

    Hartung, Steven; Shukla, H.

    2013-01-01

    Many important image processing techniques in astronomy require a massive number of computations per pixel. Among them is an image differencing technique known as Optimal Image Subtraction (OIS), which is very useful for detecting and characterizing transient phenomena. Like many image processing routines, OIS computations increase proportionally with the number of pixels being processed, and the number of pixels in need of processing is increasing rapidly. Utilizing many-core graphical processing unit (GPU) technology in a hybrid conjunction with multi-core CPU and computer clustering technologies, this work presents a new astronomy image processing pipeline architecture. The chosen OIS implementation focuses on the 2nd order spatially-varying kernel with the Dirac delta function basis, a powerful image differencing method that has seen limited deployment in part because of the heavy computational burden. This tool can process standard image calibration and OIS differencing in a fashion that is scalable with the increasing data volume. It employs several parallel processing technologies in a hierarchical fashion in order to best utilize each of their strengths. The Linux/Unix based application can operate on a single computer, or on an MPI configured cluster, with or without GPU hardware. With GPU hardware available, even low-cost commercial video cards, the OIS convolution and subtraction times for large images can be accelerated by up to three orders of magnitude.

  10. Quasinormal modes for subtracted rotating and magnetized geometries

    NASA Astrophysics Data System (ADS)

    Cvetič, M.; Gibbons, G. W.; Saleem, Z. H.

    2014-12-01

    We obtain explicit separable solutions of the wave equation of massless minimally coupled scalar fields in the subtracted geometry of four-dimensional rotating and Melvin (magnetised) four-charge black holes of the STU model, a consistent truncation of maximally supersymmetric supergravity with four types of electromagnetic fields. These backgrounds possess a hidden SL (2 ,R )×SL (2 ,R )×SO (3 ) symmetry and faithfully model the near-horizon geometry of these black holes, but locate them in a confining asymptotically conical box. For each subtracted geometry we obtain two branches of quasinormal modes, given in terms of hypergeometric functions and spherical harmonics. One branch is over-damped and the other under-damped and they exhibit rotational splitting. No black hole bomb is possible because the Killing field which corotates with the horizon is everywhere timelike outside the black hole. A five-dimensional lift of these geometries is given locally by the product of a Bañados-Teitelboim-Zanelli black hole with a two-sphere. This allows an explicit analysis of the minimally coupled massive five-dimensional scalar field. Again, there are two branches, both damped; however, now their oscillatory parts are shifted by the quantized wave number k along the fifth circle direction.

  11. Background Subtraction Based on Three-Dimensional Discrete Wavelet Transform.

    PubMed

    Han, Guang; Wang, Jinkuan; Cai, Xi

    2016-01-01

    Background subtraction without a separate training phase has become a critical task, because a sufficiently long and clean training sequence is usually unavailable, and people generally thirst for immediate detection results from the first frame of a video. Without a training phase, we propose a background subtraction method based on three-dimensional (3D) discrete wavelet transform (DWT). Static backgrounds with few variations along the time axis are characterized by intensity temporal consistency in the 3D space-time domain and, hence, correspond to low-frequency components in the 3D frequency domain. Enlightened by this, we eliminate low-frequency components that correspond to static backgrounds using the 3D DWT in order to extract moving objects. Owing to the multiscale analysis property of the 3D DWT, the elimination of low-frequency components in sub-bands of the 3D DWT is equivalent to performing a pyramidal 3D filter. This 3D filter brings advantages to our method in reserving the inner parts of detected objects and reducing the ringing around object boundaries. Moreover, we make use of wavelet shrinkage to remove disturbance of intensity temporal consistency and introduce an adaptive threshold based on the entropy of the histogram to obtain optimal detection results. Experimental results show that our method works effectively in situations lacking training opportunities and outperforms several popular techniques. PMID:27043570

  12. Photon-subtracted squeezed thermal state: Nonclassicality and decoherence

    SciTech Connect

    Hu Liyun; Xu Xuexiang; Wang Zisheng; Xu Xuefen

    2010-10-15

    We investigate nonclassical properties of the field states generated by subtracting any number of photons from the squeezed thermal state (STS). It is found that the normalization factor of photon-subtracted STS (PSSTS) is a Legendre polynomial of squeezing parameter r and average photon number n-bar of the thermal state. Expressions of several quasiprobability distributions of PSSTS are derived analytically. Furthermore, the nonclassicality is discussed in terms of the negativity of the Wigner function (WF). It is shown that the WF of single PSSTS always has negative values if n-bar

  13. Treatment of serious infections with intravenous ciprofloxacin.

    PubMed

    Scully, B E; Neu, H C

    1987-04-27

    Thirty-four patients were treated with intravenous ciprofloxacin. Thirty infections occurring in 28 patients were assessable for the efficacy analysis. The drug dosage was 300 mg every 12 hours in 19 patients and 200 mg intravenously every 12 hours in nine patients. Twelve patients were also given ciprofloxacin orally after initial intravenous therapy. The mean duration of total therapy was 31 days. The overall clinical response rate was 87 percent, and the bacteriologic response rate was 70 percent. Favorable responses were observed in 10 of 12 patients with osteomyelitis/septic arthritis; seven of eight with soft tissue infection; four of four with pneumonitis; one of two with cystic fibrosis; and four of four with urinary tract infections. Resistance to ciprofloxacin developed in three Pseudomonas aeruginosa isolates. Toxicity was minor: phlebitis occurred in six patients, nausea in six, and rash in one. Intravenously administered ciprofloxacin or intravenous ciprofloxacin followed by oral ciprofloxacin is a safe and effective therapy for serious infections. PMID:3555062

  14. Contrast-Medium-Enhanced Digital Mammography: Contrast vs. Iodine Concentration Phantom Calibration

    SciTech Connect

    Rosado-Mendez, I.; Brandan, M. E.; Villasenor, Y.; Benitez-Bribiesca, L.

    2008-08-11

    This work deals with the application of the contrast-medium-enhanced digital subtraction mammography technique in order to calibrate the contrast level in subtracted phantom images as function of iodine concentration to perform dynamic studies of the contrast-medium uptake in the breast. Previously optimized dual-energy temporal subtraction modalities were used (a) to determine radiological parameters for a dynamic clinical study composed of 1 mask+3 post-contrast images limiting the total mean glandular dose to 2.5 mGy, and (b) to perform a contrast vs iodine concentration calibration using a custom-made phantom. Calculated exposure values were applied using a commercial full-field digital mammography unit. Contrast in subtracted phantom images (one mask and one post-CM) is linear as function of iodine concentration, although the sensitivity (contrast per iodine concentration) decreases beyond 8 mg/mL. This calibration seems to apply only to thin and normal thickness breasts.

  15. Particulate contaminants of intravenous medications and infusions.

    PubMed

    Backhouse, C M; Ball, P R; Booth, S; Kelshaw, M A; Potter, S R; McCollum, C N

    1987-04-01

    Particulate contamination in small volume parenteral medications has been studied and compared with that found in a selection of large volume infusions. Particle counts in 39 commonly used small volume medications and 7 large volume infusions were performed by an automated light blockage method (HIAC) or by optical microscopy. Based on these results and a random survey of drug therapy of intensive care patients, it is concluded that the contribution of intravenous medications to the total particle load received by such patients is likely to be many times greater than from infusion fluids. Until firm evidence regarding the harmful systemic effects of drug particles is available and the manufacturing regulations adjusted appropriately, final in-line filtration of infusions immediately proximal to the intravenous cannula should be considered when drugs are being given intravenously. PMID:2884285

  16. Clinical and economic evidence for intravenous acetaminophen.

    PubMed

    Yeh, Yu-Chen; Reddy, Prabashni

    2012-06-01

    Intravenous acetaminophen received United States Food and Drug Administration approval in November 2010 for the management of mild-to-moderate pain, management of moderate-to-severe pain with adjunctive opioid analgesics, and reduction of fever. Although intravenous acetaminophen generally improved pain relief and demonstrated opioid-sparing effects compared with placebo, it did not consistently reduce the frequency of opioid-related adverse events (e.g., postoperative nausea and vomiting). The safety and efficacy of intravenous acetaminophen as an antipyretic agent have been documented in adults and children; however, its cost is several-fold higher than that of the oral and rectal formulations. Although use of intravenous acetaminophen has reduced other postoperative resource utilization (e.g., hospital length of stay) in some studies outside the United States in patients undergoing abdominal surgery, a full economic evaluation in the United States has yet to be undertaken. In addition, its administration time (15-min infusion) and packaging (glass, single-use vial) have the potential to adversely affect patient flow in the postanesthesia care unit, create burden on patient care units, and lead to drug waste. Furthermore, 1 g of intravenous acetaminophen is formulated in 100 ml of solution, which may be an issue for patients with fluid restrictions. Given the clinical and economic evidence currently available, intravenous acetaminophen should not replace oral or rectal acetaminophen, but its use may be considered in a limited number of patients who cannot receive drugs orally and rectally and who cannot tolerate other parenteral nonopioid analgesic or antipyretic agents. PMID:22570116

  17. Precocious emphysema in intravenous drug abusers.

    PubMed

    Weisbrod, G L; Rahman, M; Chamberlain, D; Herman, S J

    1993-01-01

    It is becoming increasingly clear that obstructive airway disease and early emphysema occur in some drug addicts who intravenously abuse drugs intended for oral use. We report four patients with such a history who had clinical, pathophysiologic, and radiologic evidence of severe obstructive airway disease with hyperinflation. Three patients had bullae. All had radiologic changes of intravenous talc granulomatosis. One patient had moderately severe emphysema at autopsy. The pathogenesis of this disease is uncertain but may involve synergism with cigarette smoke, direct toxic effects of the drug, or induced intravascular leukocyte sequestration causing proteolytic pulmonary injury. PMID:8320766

  18. Evaluation of the dark-object subtraction technique for adjustment of multispectral remote-sensing data

    NASA Astrophysics Data System (ADS)

    Campbell, James B.

    1993-03-01

    The well-known dark-object subtraction method has formed one of the oldest and widely used procedures for adjusting digital remote sensing data for effects of atmospheric scattering. The method's limited capabilities, relative to more sophisticated methods, are at least partially offset by its wide applicability, due its requirement for little information beyond the image itself. This study examines alternative applications of the procedure to evaluate its effectiveness, using a SPOT HRV XS image of irregular terrain in southwestern Virginia and a sequence of Landsat MSS data depicting a region in south central Virginia. Assessment of the success of the adjustment is conducted using chromaticity co-ordinates (using the method of Alfoldi and Munday (1978)), from corrected values, and comparing corrections to the original data. A successful correction shifts chromaticity co-ordinates away from the equal radiance point towards the purer regions near edges of the diagram. Further, some categories, when corrected successfully, will occupy known positions within chromaticity space. Assessment of the modification proposed by Chavez (1988) was conducted by examining the effects of choosing alternative starting haze values, and effects of alternative choices for atmospheric models. One difficulty in applying the 1988 modification is that it appears to be difficult to make accurate assessments of atmospheric conditions.

  19. The association between symbolic and nonsymbolic numerical magnitude processing and mental versus algorithmic subtraction in adults.

    PubMed

    Linsen, Sarah; Torbeyns, Joke; Verschaffel, Lieven; Reynvoet, Bert; De Smedt, Bert

    2016-03-01

    There are two well-known computation methods for solving multi-digit subtraction items, namely mental and algorithmic computation. It has been contended that mental and algorithmic computation differentially rely on numerical magnitude processing, an assumption that has already been examined in children, but not yet in adults. Therefore, in this study, we examined how numerical magnitude processing was associated with mental and algorithmic computation, and whether this association with numerical magnitude processing was different for mental versus algorithmic computation. We also investigated whether the association between numerical magnitude processing and mental and algorithmic computation differed for measures of symbolic versus nonsymbolic numerical magnitude processing. Results showed that symbolic, and not nonsymbolic, numerical magnitude processing was associated with mental computation, but not with algorithmic computation. Additional analyses showed, however, that the size of this association with symbolic numerical magnitude processing was not significantly different for mental and algorithmic computation. We also tried to further clarify the association between numerical magnitude processing and complex calculation by also including relevant arithmetical subskills, i.e. arithmetic facts, needed for complex calculation that are also known to be dependent on numerical magnitude processing. Results showed that the associations between symbolic numerical magnitude processing and mental and algorithmic computation were fully explained by individual differences in elementary arithmetic fact knowledge. PMID:26914586

  20. Digital Preservation.

    ERIC Educational Resources Information Center

    Yakel, Elizabeth

    2001-01-01

    Reviews research on digital preservation issues, including born-digital and digitally recreated documents. Discusses electronic records research; metadata and other standards; electronic mail; Web-based documents; moving images media; selection of materials for digitization, including primary sources; administrative issues; media stability…

  1. Cadmium Subtraction Method for the Active Albedo Neutron Interrogation of Uranium

    SciTech Connect

    Worrall, Louise G.; Croft, Stephen

    2015-02-01

    This report describes work performed under the Next Generation Safeguards Initiative (NGSI) Cadmium Subtraction Project. The project objective was to explore the difference between the traditional cadmium (Cd) ratio signature and a proposed alternative Cd subtraction (or Cd difference) approach. The thinking behind the project was that a Cd subtraction method would provide a more direct measure of multiplication than the existing Cd ratio method. At the same time, it would be relatively insensitive to changes in neutron detection efficiency when properly calibrated. This is the first published experimental comparison and evaluation of the Cd ratio and Cd subtraction methods.

  2. A posteriori registration and subtraction of periapical radiographs for the evaluation of external apical root resorption after orthodontic treatment

    PubMed Central

    Chibinski, Ana Cláudia; Coelho, Ulisses; Wambier, Letícia Stadler; Zedebski, Rosário de Arruda Moura; de Moraes, Mari Eli Leonelli; de Moraes, Luiz Cesar

    2016-01-01

    Purpose This study employed a posteriori registration and subtraction of radiographic images to quantify the apical root resorption in maxillary permanent central incisors after orthodontic treatment, and assessed whether the external apical root resorption (EARR) was related to a range of parameters involved in the treatment. Materials and Methods A sample of 79 patients (mean age, 13.5±2.2 years) with no history of trauma or endodontic treatment of the maxillary permanent central incisors was selected. Periapical radiographs taken before and after orthodontic treatment were digitized and imported to the Regeemy software. Based on an analysis of the posttreatment radiographs, the length of the incisors was measured using Image J software. The mean EARR was described in pixels and relative root resorption (%). The patient's age and gender, tooth extraction, use of elastics, and treatment duration were evaluated to identify possible correlations with EARR. Results The mean EARR observed was 15.44±12.1 pixels (5.1% resorption). No differences in the mean EARR were observed according to patient characteristics (gender, age) or treatment parameters (use of elastics, treatment duration). The only parameter that influenced the mean EARR of a patient was the need for tooth extraction. Conclusion A posteriori registration and subtraction of periapical radiographs was a suitable method to quantify EARR after orthodontic treatment, and the need for tooth extraction increased the extent of root resorption after orthodontic treatment. PMID:27051635

  3. Ultrathin Nanostructured Metals for Highly Transmissive Plasmonic Subtractive Color Filters

    PubMed Central

    Zeng, Beibei; Gao, Yongkang; Bartoli, Filbert J.

    2013-01-01

    Plasmonic color filters employing a single optically-thick nanostructured metal layer have recently generated considerable interest as an alternative to colorant-based color filtering technologies, due to their reliability, ease of fabrication, and high color tunability. However, their relatively low transmission efficiency (~30%) needs to be significantly improved for practical applications. The present work reports, for the first time, a novel plasmonic subtractive color filtering scheme that exploits the counter-intuitive phenomenon of extraordinary low transmission (ELT) through an ultrathin nanostructured metal film. This approach relies on a fundamentally different color filtering mechanism than that of existing plasmonic additive color filters, and achieves unusually high transmission efficiencies of 60 ~ 70% for simple architectures. Furthermore, owing to short-range interactions of surface plasmon polaritons at ELT resonances, our design offers high spatial resolution color filtering with compact pixel size close to the optical diffraction limit (~λ/2), creating solid applications ranging from imaging sensors to color displays. PMID:24100869

  4. Background Subtraction Based on Color and Depth Using Active Sensors

    PubMed Central

    Fernandez-Sanchez, Enrique J.; Diaz, Javier; Ros, Eduardo

    2013-01-01

    Depth information has been used in computer vision for a wide variety of tasks. Since active range sensors are currently available at low cost, high-quality depth maps can be used as relevant input for many applications. Background subtraction and video segmentation algorithms can be improved by fusing depth and color inputs, which are complementary and allow one to solve many classic color segmentation issues. In this paper, we describe one fusion method to combine color and depth based on an advanced color-based algorithm. This technique has been evaluated by means of a complete dataset recorded with Microsoft Kinect, which enables comparison with the original method. The proposed method outperforms the others in almost every test, showing more robustness to illumination changes, shadows, reflections and camouflage. PMID:23857259

  5. AutoDipole - Automated generation of dipole subtraction terms -

    NASA Astrophysics Data System (ADS)

    Hasegawa, K.; Moch, S.; Uwer, P.

    2010-10-01

    We present an automated generation of the subtraction terms for next-to-leading order QCD calculations in the Catani-Seymour dipole formalism. For a given scattering process with n external particles our Mathematica package generates all dipole terms, allowing for both massless and massive dipoles. The numerical evaluation of the subtraction terms proceeds with MadGraph, which provides Fortran code for the necessary scattering amplitudes. Checks of the numerical stability are discussed. Program summaryProgram title: AutoDipole Catalogue identifier: AEGO_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGO_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 138 042 No. of bytes in distributed program, including test data, etc.: 1 117 665 Distribution format: tar.gz Programming language: Mathematica and Fortran Computer: Computers running Mathematica (version 7.0) Operating system: The package should work on every Linux system supported by Mathematica. Detailed tests have been performed on Scientific Linux as supported by DESY and CERN and on openSUSE and Debian. RAM: Depending on the complexity of the problem, recommended at least 128 MB RAM Classification: 11.5 External routines: MadGraph (including HELAS library) available under http://madgraph.hep.uiuc.edu/ or http://madgraph.phys.ucl.ac.be/ or http://madgraph.roma2.infn.it/. A copy of the tar file, MG_ME_SA_V4.4.30, is included in the AutoDipole distribution package. Nature of problem: Computation of next-to-leading order QCD corrections to scattering cross sections, regularization of real emission contributions. Solution method: Catani-Seymour subtraction method for massless and massive partons [1,2]; Numerical evaluation of subtracted matrix elements interfaced to MadGraph [3-5] (stand-alone version) using

  6. Plasma tomographic reconstruction from tangentially viewing camera with background subtraction

    SciTech Connect

    Odstrčil, M.; Mlynář, J.; Weinzettl, V.; Háček, P.; Verdoolaege, G.; Berta, M.

    2014-01-15

    Light reflections are one of the main and often underestimated issues of plasma emissivity reconstruction in visible light spectral range. Metallic and other specular components of tokamak generate systematic errors in the optical measurements that could lead to wrong interpretation of data. Our analysis is performed at data from the tokamak COMPASS. It is a D-shaped tokamak with specular metallic vessel and possibility of the H-mode plasma. Data from fast visible light camera were used for tomographic reconstruction with background reflections subtraction to study plasma boundary. In this article, we show that despite highly specular tokamak wall, it is possible to obtain a realistic reconstruction. The developed algorithm shows robust results despite of systematic errors in the optical measurements and calibration. The motivation is to obtain an independent estimate of the plasma boundary shape.

  7. Plasma tomographic reconstruction from tangentially viewing camera with background subtraction.

    PubMed

    Odstrčil, M; Mlynář, J; Weinzettl, V; Háček, P; Odstrčil, T; Verdoolaege, G; Berta, M; Szabolics, T; Bencze, A

    2014-01-01

    Light reflections are one of the main and often underestimated issues of plasma emissivity reconstruction in visible light spectral range. Metallic and other specular components of tokamak generate systematic errors in the optical measurements that could lead to wrong interpretation of data. Our analysis is performed at data from the tokamak COMPASS. It is a D-shaped tokamak with specular metallic vessel and possibility of the H-mode plasma. Data from fast visible light camera were used for tomographic reconstruction with background reflections subtraction to study plasma boundary. In this article, we show that despite highly specular tokamak wall, it is possible to obtain a realistic reconstruction. The developed algorithm shows robust results despite of systematic errors in the optical measurements and calibration. The motivation is to obtain an independent estimate of the plasma boundary shape. PMID:24517767

  8. Unique-sample selection via near-infrared spectral subtraction

    SciTech Connect

    Honigs, D.E.; Hieftje, G.M.; Mark, H.L.; Hirschfeld, T.B.

    1985-10-01

    A method is described and tested for improving the training sample set in near-infrared diffuse-reflectance analysis (NIRA). Utilizing linear algebra techniques similar to spectral subtraction, this method selects the most spectrally unique samples from those in a larger pool. Upon being analyzed, these spectrally unique samples are found to have a significantly larger variation in their chemical compositions than the pool of samples from which they were selected. When the spectrally unique samples are incorporated into a NIRA training set, the resulting calibration is improved in two ways: first, the larger variations in sample composition help to make a NIRA calibration more robust and less subject to unexpected variations in the sample matrix; second, use of the spectrally unique samples reduces the time and effort involved in developing a NIRA method of analysis. 13 references, 2 figures, 7 tables.

  9. PSF subtraction to search for distant Jupiters with SPITZER

    NASA Astrophysics Data System (ADS)

    Rameau, Julien; Artigau, Etienne; Baron, Frédérique; Lafrenière, David; Doyon, Rene; Malo, Lison; Naud, Marie-Eve; Delorme, Philippe; Janson, Markus; Albert, Loic; Gagné, Jonathan; Beichman, Charles

    2015-12-01

    In the course of the search for extrasolar planets, a focus has been made towards rocky planets very close (within few AUs) to their parent stars. However, planetary systems might host gas giants as well, possibly at larger separation from the central star. Direct imaging is the only technique able to probe the outer part of planetary systems. With the advent of the new generation of planet finders like GPI and SPHERE, extrasolar systems are now studied at the solar system scale. Nevertheless, very extended planetary systems do exist and have been found (Gu Ps, AB Pic b, etc.). They are easier to detect and characterize. They are also excellent proxy for close-in gas giants that are detected from the ground. These planets have no equivalent in our solar system and their origin remain a matter of speculation. In this sense, studying planetary systems from its innermost to its outermost part is therefore mandatory to have a clear understanding of its architecture, hence hints of its formation and evolution. We are carrying out a space-based survey using SPITZER to search for distant companions around a well-characterized sample of 120 young and nearby stars. We designed an observing strategy that allows building a very homogeneous PSF library. With this library, we perform a PSF subtraction to search for planets from 10’’ down to 1’’. In this poster, I will present the library, the different algorithms used to subtract the PSF, and the promising detection sensitivity that we are able to reach with this survey. This project to search for the most extreme planetary systems is unique in the exoplanet community. It is also the only realistic mean of directly imaging and subsequently obtaining spectroscopy of young Saturn or Jupiter mass planets in the JWST-era.

  10. Eastern Equine Encephalitis Treated With Intravenous Immunoglobulins

    PubMed Central

    Mukerji, Shibani S.; Lam, Alice D.

    2016-01-01

    We report the case of a 68-year-old man from southeastern Massachusetts presenting with encephalitis due to eastern equine encephalitis (EEE) virus. Despite the high morbidity and mortality rate of EEE, the patient made a near complete recovery in the setting of receiving early intravenous immunoglobulins. PMID:26740855

  11. Health Instruction Packages: Venipuncture and Intravenous Therapy.

    ERIC Educational Resources Information Center

    Gray, P. Allen, Jr.; And Others

    Text, illustrations, and exercises are utilized in these five learning modules to instruct nursing students in techniques for initiating intravenous (I.V.) therapy. The first module, "Selection of a Venipuncture Site: Arm" by P. Allen Gray, Jr., describes the utilization of a tourniquet in locating filled veins in the arm. The second module,…

  12. Intravenous/oral ciprofloxacin therapy versus intravenous ceftazidime therapy for selected bacterial infections.

    PubMed

    Gaut, P L; Carron, W C; Ching, W T; Meyer, R D

    1989-11-30

    The efficacy and toxicity of sequential intravenous and oral ciprofloxacin therapy was compared with intravenously administered ceftazidime in a prospective, randomized, controlled, non-blinded trial. Thirty-two patients (16 patients receiving ciprofloxacin and 16 patients receiving ceftazidime) with 38 infections caused by susceptible Pseudomonas aeruginosa, enteric gram-negative rods, Salmonella group B, Serratia marcescens, Pseudomonas cepacia, and Xanthomonas maltophilia at various sites were evaluable for determination of efficacy. Length of therapy varied from seven to 25 days. Concomitant antimicrobials included intravenously administered beta-lactams for gram-positive organisms, intravenous/oral metronidazole and clindamycin for anaerobes, and intravenous/local amphotericin B for Candida albicans. Intravenous administration of 200 mg ciprofloxacin every 12 hours to 11 patients produced peak serum levels between 1.15 and 3.12 micrograms/ml; trough levels ranged between 0.08 and 0.86 micrograms/ml. Overall response rates were similar for patients receiving ciprofloxacin and ceftazidime. Emergence of resistance was similar in both groups--one Enterobacter cloacae and two P. aeruginosa became resistant after ciprofloxacin therapy and two P. aeruginosa became resistant after ceftazidime therapy. The frequency of superinfection with a variety of organisms was also similar in both groups. Adverse events related to ciprofloxacin included transient pruritus at the infusion site and generalized rash leading to drug discontinuation (one patient each), and with ceftazidime adverse effects included pain at the site of infusion and the development of allergic interstitial nephritis (one patient each). Overall, intravenous/oral ciprofloxin therapy appears to be as safe and effective as intravenous ceftazidime therapy in the treatment of a variety of infections due to susceptible aerobic gram-negative organisms. PMID:2686417

  13. Computer enhanced digital angiography.

    PubMed

    Vas, R; Diamond, G A; Levisman, J A; Nakano, F H; Neidorf, B S; Rose, R M; Whiting, J S; Forrester, J S

    1982-05-01

    A new computer image enhancement technique was employed on cardiac images of 10 dogs and 7 patients to demonstrate the feasibility of an on-line automatic delineation of the left ventricular endocardial silhouette with a peripheral venous injection of contrast material while simultaneously reducing the x-ray dosage. This technique employs a very fast analog-to-digital conversion system capable of digitizing on-line video frames. By storing and continuously updating the first 30 video frames and then subtracting each incoming frame from this memory, most of the background is eliminated leaving only the contrast filled ventricle. Using calibrated densitometric measurements, we found that iodine concentrations in the human left ventricle following venous injection of 40 ml Renografin-76 (25 ml/s), peaked at 4.3 +/- 0.3 mg/ml (mean +/- SD) compared to 14.8 +/- 0.8 mg/ml following direct injection of 40 ml at 13 ml/s (p less than 0.001). The computer enhanced venous-injected images had an optical contrast 14 times greater than that of the unenhanced direct left ventriculogram. This increase in optical contrast provided unambiguous subjective definition of the endocardial borders. This technique is applicable to both central and peripheral contrast injection whereby high quality images can be obtained at approximately 98% reduction in radiation (5 mA, 65-85 kV), allowing performance of serial studies. PMID:7094444

  14. Efficacy of Intravenous Paracetamol Versus Intravenous Morphine in Acute Limb Trauma

    PubMed Central

    Jalili, Mohammad; Mozaffarpour Noori, Ali; Sedaghat, Mojtaba; Safaie, Arash

    2016-01-01

    Background: Efficient pain management is one of the most important components of care in the field of emergency medicine. Objectives: This study was conducted to compare intravenous paracetamol and intravenous morphine sulfate for acute pain reduction in patients with limb trauma. Patients and Methods: In a randomized double-blinded clinical trial, all patients (aged 18 years and older) with acute limb trauma and a pain score of greater than 3/10 in the emergency department were recruited; they received either 1 g intravenous paracetamol or 0.1 mg/kg intravenous morphine sulfate over 15 minutes. The primary outcome was the pain score measured on a numerical rating scale at 0, 15 and 30 minutes after commencing drug administration. The requirement for rescue analgesia and the frequency of adverse reactions were also recorded. Results: Sixty patients randomly received either IV paracetamol (n = 30) or IV morphine (n = 30). The mean reduction in numerical rating scale pain intensity scores at 30 minutes was 3.86 (± 1.61) for paracetamol, and 2.16 (± 1.39) for morphine. However, pain relief was significantly higher in the paracetamol group compared to the morphine group (P < 0.001). Four patients in the paracetamol group and 15 patients in the morphine group needed rescue analgesia and the difference was significant (P = 0.05). Conclusions: Intravenous paracetamol appears to provide better analgesia than intravenous morphine in acute limb trauma. Further larger studies are required. PMID:27218042

  15. Hydrothorax, hydromediastinum and pericardial effusion: a complication of intravenous alimentation.

    PubMed

    Damtew, B; Lewandowski, B

    1984-06-15

    Complications secondary to intravenous alimentation are rare but potentially lethal. Massive bilateral pleural effusions and a pericardial effusion developed in a patient receiving prolonged intravenous alimentation. Severe respiratory distress and renal failure ensued. He recovered with appropriate treatment. PMID:6428731

  16. Model Evaluation and Multiple Strategies in Cognitive Diagnosis: An Analysis of Fraction Subtraction Data

    ERIC Educational Resources Information Center

    de la Torre, Jimmy; Douglas, Jeffrey A.

    2008-01-01

    This paper studies three models for cognitive diagnosis, each illustrated with an application to fraction subtraction data. The objective of each of these models is to classify examinees according to their mastery of skills assumed to be required for fraction subtraction. We consider the DINA model, the NIDA model, and a new model that extends the…

  17. Curricular Approaches to Connecting Subtraction to Addition and Fostering Fluency with Basic Differences in Grade 1

    ERIC Educational Resources Information Center

    Baroody, Arthur J.

    2016-01-01

    Six widely used US Grade 1 curricula do not adequately address the following three developmental prerequisites identified by a proposed learning trajectory for the meaningful learning of the subtraction-as-addition strategy (e.g., for 13-8 think "what + 8 = 13?"): (a) reverse operations (adding 8 is undone by subtracting 8); (b) common…

  18. Toddler Subtraction with Large Sets: Further Evidence for an Analog-Magnitude Representation of Number

    ERIC Educational Resources Information Center

    Slaughter, Virginia; Kamppi, Dorian; Paynter, Jessica

    2006-01-01

    Two experiments were conducted to test the hypothesis that toddlers have access to an analog-magnitude number representation that supports numerical reasoning about relatively large numbers. Three-year-olds were presented with subtraction problems in which initial set size and proportions subtracted were systematically varied. Two sets of cookies…

  19. Putting Essential Understanding of Addition and Subtraction into Practice: Pre-K-2

    ERIC Educational Resources Information Center

    Caldwell, Janet H.; Kobett, Beth; Karp, Karen

    2014-01-01

    Do your students have the incorrect idea that addition "makes numbers bigger" and subtraction "makes numbers smaller"? Do they believe that subtraction is always "taking away"? What tasks can you offer--what questions can you ask--to determine what your students know or don't know--and move them forward in their…

  20. Can Research Inform Classroom Practice?: The Particular Case of Buggy Algorithms and Subtraction Errors.

    ERIC Educational Resources Information Center

    McNamara, David; Pettitt, Deirdre

    1991-01-01

    Reviews a body of psychological research which investigated children's errors in subtraction computations to assess whether the literature offers valuable, relevant information for those teaching subtraction and remedying student errors. It concludes that the research offers teachers little, so they must fall back on their knowledge and…

  1. Changes in transmural distribution of myocardial perfusion assessed by quantitative intravenous myocardial contrast echocardiography in humans

    PubMed Central

    Fukuda, S; Muro, T; Hozumi, T; Watanabe, H; Shimada, K; Yoshiyama, M; Takeuchi, K; Yoshikawa, J

    2002-01-01

    Objective: To clarify whether changes in transmural distribution of myocardial perfusion under significant coronary artery stenosis can be assessed by quantitative intravenous myocardial contrast echocardiography (MCE) in humans. Methods: 31 patients underwent dipyridamole stress MCE and quantitative coronary angiography. Intravenous MCE was performed by continuous infusion of Levovist. Images were obtained from the apical four chamber view with alternating pulsing intervals both at rest and after dipyridamole infusion. Images were analysed offline by placing regions of interest over both endocardial and epicardial sides of the mid-septum. The background subtracted intensity versus pulsing interval plots were fitted to an exponential function, y = A (1 − e−βt), where A is plateau level and β is rate of rise. Results: Of the 31 patients, 16 had significant stenosis (> 70%) in the left anterior descending artery (group A) and 15 did not (group B). At rest, there were no differences in the A endocardial to epicardial ratio (A-EER) and β-EER between the two groups (mean (SD) 1.2 (0.6) v 1.2 (0.8) and 1.2 (0.7) v 1.1 (0.6), respectively, NS). During hyperaemia, β-EER in group A was significantly lower than that in group B (1.0 (0.5) v 1.4 (0.5), p < 0.05) and A-EER did not differ between the two groups (1.0 (0.5) v 1.2 (0.4), NS). Conclusions: Changes in transmural distribution of myocardial perfusion under significant coronary artery stenosis can be assessed by quantitative intravenous MCE in humans. PMID:12231594

  2. Canonical quaternary signed-digit arithmetic using optoelectronics symbolic substitution

    NASA Astrophysics Data System (ADS)

    Cherri, A. K.; Khachab, N. I.

    1996-07-01

    A higher radix based signed-digit number system, such as the quaternary signed-digit (QSD) number system, allows higher information storage density, less complexity, fewer system components, and fewer cascaded gates and operations. An optoelectronics symbolic substitution scheme to handle the parallel quaternary signed-digit (QSD) arithmetic operations is proposed. A conversion algorithm is employed on the QSD numbers to simplify the addition process and reduce the number of the optical symbolic substitution rules. The optical addition operation of two QSD numbers is performed in one-step. An efficient shared content-addressable memory (SCAM)-based optical implementation of the QSD addition/subtraction operations employs a fixed number of minterms for any operand length. The canonical QSD number addition/subtraction scheme requires a significantly reduced number of minterms when compared with a similar previously reported technique.

  3. Early detection of postoperative residual tumor using image subtraction

    NASA Astrophysics Data System (ADS)

    Narayan, Suresh B.; Dhawan, Atam P.; Taha, Jamal M.; Gaskill-Shipley, Mary; Lamba, Michael; Sarwal, Alok; Chitre, Yateen S.

    1995-05-01

    The detection after surgery of residual tumor from magnetic resonance (MR) images is difficult due to the low contrast level of the images. Gadolinium-enhanced MR imaging has been found valuable in detecting residual enhancing tumor when performed within 72 hours after surgery. The patient is scanned by the MR scanner with and without infusion of gadolinium, a contrast agent. Usually, the estimation of post-operative tumor volume is done by visual comparison of the T1 MR images obtained with and without gadolinium infusion. The T1 MR images, in most cases, without contrast demonstrates areas of hyper intensities (high brightness levels), consistent with hemorrhage. These hyper intense areas often make it difficult to detect residual tumor in post contrast images. This is due to the presence of both acute hemorrhage and gadolinium enhancement which have high brightness levels in T1 MR images. Even in MR images taken within 72 hours after surgery, detection of tumor enhancement in areas of increased T1 signal produced by blood products or by postoperative changes can be difficult when performed by the naked eye. Due to these problems, the quantification of residual tumor becomes a subjective issue among neuro-radiologists. Thus to reduce errors produced by the human factor, an automated procedure to detect residual tumor is required. We have developed a technique to differentiate tumor enhancement from postoperative changes and blood products on MR imaging. The technique involves fusion of pre- and post-gadolinium MR images performed in the immediate postoperative period. Computerized slice based substraction is then done on the corresponding fused images of the two sets. The subtraction process results in a composite slice, which is examined for differences between pre- and post-gadolinium studies. The presented technique was tested on 14 cases in which MR images were obtained from brain tumor patients within 72 hours after surgery. The subtraction technique easily

  4. Visualization of Coronary Arteries from Intravenous Angiograms

    NASA Technical Reports Server (NTRS)

    Selzer, Robert H.

    1985-01-01

    Under most circumstances, the coronary arteries are not satisfactorily visualized in intravenous angiograms. The objective of this study is to develop computer image enhancement methods that will improve the quality of the latent coronary images to a degree sufficient to detect an obstructive lesion. Such a technique, if successful, could be used as a first step alternative to conventional coronary angiography for individuals with ambiguous noninvasive cardiac tests. The determination of no lesion from the intravenous procedure would relieve the need for the conventional angiogram, while verification of an obstructive lesion could be followed by a conventional angiogram. The nature of the imaging problem and a description of the methods and initial processing results are described in this paper.

  5. Intravenous immunoglobulin in pediatrics: A review

    PubMed Central

    Prasad, A.N.; Chaudhary, Sanjay

    2013-01-01

    There has been a rapid expansion of the use of intravenous immunoglobulin (IVIG) for an ever-growing number of conditions. IVIG is used at a ‘replacement dose’ (400–600 mg/kg/month) in antibody deficiencies and is used at a high dose (2 g/kg) as an ‘immunomodulatory’ agent in an increasing number of immune and inflammatory disorders.1 The limitations for IVIG are the cost of the preparation and the need for intravenous infusions. Due to the cost, shortages and growing use of IVIG there have been attempts to develop evidence-based guidelines for the use of IVIG in a wide variety of immune disorders in children and neonates. This commentary provides the recommendations and recent publication regarding the use of IVIG in various conditions in children. PMID:25378784

  6. [High-dose intravenous immunoglobulin treatment].

    PubMed

    Taneichi, Hiromichi; Miyawaki, Toshio

    2011-03-01

    Intravenous immunoglobulin treatment was introduced as replacement therapy for patients with congenital agammaglobulinemia. For the last three decades, high-dose intravenous immunoglobulin (HD-IVIg) has been used for autoimmune diseases and systemic inflammatory diseases, such as idiopathic thrombocytopenic purpura, Kawasaki disease, myasthenia gravis and Guillain-Barré/syndrome. Although the immunomodulatory mechanisms of HD-IVIg remains unclear. Its use in many other diseases have been expected. Acute encephalitis/encephalopathy is a complex neurological syndrome associated with significant morbidity and mortality. The pathogenicity of brain dysfunction is still unknown. This review provides an overview and discussion of mechanisms that may be responsible for HD-IVIg effects in acute encephalitis/encephalopathy. PMID:21400848

  7. [How to control postoperative pain: intravenous route].

    PubMed

    Occella, P; Vivaldi, F

    2003-12-01

    Intravenous administration of analgesic drugs is one of the most common ways to control post-operative pain. It can be used in almost all kinds of surgical interventions and particularly those of medium and high complexity. Besides, when other techniques are contraindicated because of clinical and/or managing problems, intravenous way finds its best application. Among analgesic drugs NSAID (ketorolac) and opioids (tramadol, morphine, buprenorphine) are most frequently used. As to administration techniques, elastomeric pump is, according to personal experience, a simple-to-manage, practical and precise device with lower cost respect to other administration set. Elastomeric pump is a single use reservoir that allows continuous administration of drugs with a uniform pre-set infusion speed. Finally, guide-lines, showing pre-load and infusion doses of analgesic drugs, based on pain intensity, are presented. PMID:14663417

  8. Intravenous Lipid Emulsions in Parenteral Nutrition.

    PubMed

    Fell, Gillian L; Nandivada, Prathima; Gura, Kathleen M; Puder, Mark

    2015-09-01

    Fat is an important macronutrient in the human diet. For patients with intestinal failure who are unable to absorb nutrients via the enteral route, intravenous lipid emulsions play a critical role in providing an energy-dense source of calories and supplying the essential fatty acids that cannot be endogenously synthesized. Over the last 50 y, lipid emulsions have been an important component of parenteral nutrition (PN), and over the last 10-15 y many new lipid emulsions have been manufactured with the goal of improving safety and efficacy profiles and achieving physiologically optimal formulations. The purpose of this review is to provide a background on the components of lipid emulsions, their role in PN, and to discuss the lipid emulsions available for intravenous use. Finally, the role of parenteral fat emulsions in the pathogenesis and management of PN-associated liver disease in PN-dependent pediatric patients is reviewed. PMID:26374182

  9. Diurnal Variation in Response to Intravenous Glucose*

    PubMed Central

    Whichelow, Margaret J.; Sturge, R. A.; Keen, H.; Jarrett, R. J.; Stimmler, L.; Grainger, Susan

    1974-01-01

    Intravenous glucose tolerance tests (25 g) were performed in the morning and afternoon on 13 apparently normal persons. The individual K values (rate of decline of blood sugar) were all higher in the morning tests, and the mean values were significantly higher in the morning. Fasting blood sugar levels were slightly lower in the afternoon. There was no difference between the fasting morning and afternoon plasma insulin levels, but the levels after glucose were lower in the afternoon. Growth hormone levels were low at all times in non-apprehensive subjects and unaffected by glucose. The results suggest that the impaired afternoon intravenous glucose tolerance, like oral glucose tolerance, is associated with impaired insulin release and insulin resistance. PMID:4817160

  10. Digital Citizenship

    ERIC Educational Resources Information Center

    Isman, Aytekin; Canan Gungoren, Ozlem

    2014-01-01

    Era in which we live is known and referred as digital age.In this age technology is rapidly changed and developed. In light of these technological advances in 21st century, schools have the responsibility of training "digital citizen" as well as a good citizen. Digital citizens must have extensive skills, knowledge, Internet and …

  11. Intravenous access: a comparison of two methods.

    PubMed

    Duffy, B L; Lee, J S

    1983-05-01

    The reliability in providing a continued venous route to the circulation is compared between a winged needle (Abbott "Butterfly--23 INT") and a plastic catheter (Jelco Teflon "Catheter Placement Unit", 22 gauge). The catheter remained within the vein in all cases and had a much lower incidence of total obstruction during the study period. Where an intravenous infusion is not in place, a plastic catheter provides a more reliable access route to the circulation than does a winged needle. PMID:6869776

  12. Disinfection practices in intravenous drug administration.

    PubMed

    Helder, Onno K; Kornelisse, René F; Reiss, Irwin K M; Ista, Erwin

    2016-06-01

    The aim of the study was to determine the effectiveness of a feedback intervention on adherence to disinfection procedures during intravenous medication preparation and administration. We found that full adherence to the protocols significantly improved from 7.3% to 21.5% (P < .001) regarding medication preparation and from 7.9% to 15.5% (P = .012) regarding medication administration. However, disinfection practices still need improvement. PMID:26899528

  13. Artifacts in digital coincidence timing

    DOE PAGESBeta

    Moses, W. W.; Peng, Q.

    2014-10-16

    Digital methods are becoming increasingly popular for measuring time differences, and are the de facto standard in PET cameras. These methods usually include a master system clock and a (digital) arrival time estimate for each detector that is obtained by comparing the detector output signal to some reference portion of this clock (such as the rising edge). Time differences between detector signals are then obtained by subtracting the digitized estimates from a detector pair. A number of different methods can be used to generate the digitized arrival time of the detector output, such as sending a discriminator output into amore » time to digital converter (TDC) or digitizing the waveform and applying a more sophisticated algorithm to extract a timing estimator.All measurement methods are subject to error, and one generally wants to minimize these errors and so optimize the timing resolution. A common method for optimizing timing methods is to measure the coincidence timing resolution between two timing signals whose time difference should be constant (such as detecting gammas from positron annihilation) and selecting the method that minimizes the width of the distribution (i.e. the timing resolution). Unfortunately, a common form of error (a nonlinear transfer function) leads to artifacts that artificially narrow this resolution, which can lead to erroneous selection of the 'optimal' method. In conclusion, the purpose of this note is to demonstrate the origin of this artifact and suggest that caution should be used when optimizing time digitization systems solely on timing resolution minimization.« less

  14. Intravenous Lipids for Preterm Infants: A Review

    PubMed Central

    Salama, Ghassan SA; Kaabneh, Mahmmoud AF; Almasaeed, Mai N; Alquran, Mohammad IA

    2015-01-01

    Extremely low birth weight infants (ELBW) are born at a time when the fetus is undergoing rapid intrauterine brain and body growth. Continuation of this growth in the first several weeks postnatally during the time these infants are on ventilator support and receiving critical care is often a challenge. These infants are usually highly stressed and at risk for catabolism. Parenteral nutrition is needed in these infants because most cannot meet the majority of their nutritional needs using the enteral route. Despite adoption of a more aggressive approach with amino acid infusions, there still appears to be a reluctance to use early intravenous lipids. This is based on several dogmas that suggest that lipid infusions may be associated with the development or exacerbation of lung disease, displace bilirubin from albumin, exacerbate sepsis, and cause CNS injury and thrombocytopena. Several recent reviews have focused on intravenous nutrition for premature neonate, but very little exists that provides a comprehensive review of intravenous lipid for very low birth and other critically ill neonates. Here, we would like to provide a brief basic overview, of lipid biochemistry and metabolism of lipids, especially as they pertain to the preterm infant, discuss the origin of some of the current clinical practices, and provide a review of the literature, that can be used as a basis for revising clinical care, and provide some clarity in this controversial area, where clinical care is often based more on tradition and dogma than science. PMID:25698888

  15. The Variable Rate Intravenous Insulin Infusion Protocol.

    PubMed

    Collard, Benjamin; Sturgeon, Jonathan; Patel, Natasha; Asharia, Shabbar

    2014-01-01

    Insulin use among inpatients is high and associated with severe and regular medication errors. An initial baseline audit showed a wide variation in the prescription of intravenous insulin within the trust. These included variation in the choice of fluid prescribed, electrolyte levels not consistently checked, handwritten illegible prescriptions, and varying parameters set for adjustment of the prescription. A Variable Rate Intravenous Insulin Infusion protocol (VRIII)) was introduced to standardize intravenous insulin prescription throughout the trust by all members of the clinical team. We looked at and measured uptake and effects of the VRIII protocol in improving standardization of insulin prescription for inpatients on insulin at St George's NHS trust. The protocol was uploaded to the intranet to allow access 24 hours a day and the staff educated about it. The VRIII protocol was routinely used successfully throughout the trust. Any initial problems were addressed through education of clinical staff. The protocol has shown decreased prescribing and administrative errors, whilst demonstrating good glucose and electrolyte control. Use of a standardized protocol helps reduce medication errors and demonstrates good glycaemic control. Regular and continued education of clinical staff is necessary to maintain its efficacy. PMID:26734228

  16. Contrast agent choice for intravenous coronary angiography

    SciTech Connect

    Zeman, H.D.; Siddons, D.P.

    1989-01-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation x-rays and an iodine containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic x-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the x-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation x-rays is visualizing a coronary artery through the left ventricle or aorta which also contains a contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth.

  17. Fast background subtraction for moving cameras based on nonparametric models

    NASA Astrophysics Data System (ADS)

    Sun, Feng; Qin, Kaihuai; Sun, Wei; Guo, Huayuan

    2016-05-01

    In this paper, a fast background subtraction algorithm for freely moving cameras is presented. A nonparametric sample consensus model is employed as the appearance background model. The as-similar-as-possible warping technique, which obtains multiple homographies for different regions of the frame, is introduced to robustly estimate and compensate the camera motion between the consecutive frames. Unlike previous methods, our algorithm does not need any preprocess step for computing the dense optical flow or point trajectories. Instead, a superpixel-based seeded region growing scheme is proposed to extend the motion cue based on the sparse optical flow to the entire image. Then, a superpixel-based temporal coherent Markov random field optimization framework is built on the raw segmentations from the background model and the motion cue, and the final background/foreground labels are obtained using the graph-cut algorithm. Extensive experimental evaluations show that our algorithm achieves satisfactory accuracy, while being much faster than the state-of-the-art competing methods.

  18. Subtractive transcriptomics : establishing polarity drives human endothelial morphogenesis

    SciTech Connect

    Glesne, D. A.; Zhang, W.; Mandava, S.; Ursos, L.; Buell, M. E.; Makowski, L.; Rodi, D. J.; Biosciences Division

    2006-04-15

    Although investigations of mature normal and tumor-derived capillaries have resulted in characterization of these structures at the phenotypic level, less is known regarding the initial molecular cues for cellular assembly of endothelial cells into human capillaries. Here, we employ a novel combination of microenvironmental manipulation and microarray data filtration over narrowly delineated temporal data series to identify the morphogenesis component apart from the proliferation component, as pooled human microvascular-derived endothelial cells are induced to form capillary-like structures in vitro in a murine tumor-derived matrix. The 217 morphogenesis-specific genes identified using this subtractive transcriptomics approach are mostly independent of the angiogenic proteins currently used as therapeutic targets for aberrant angiogenesis. Quantitative real-time PCR was used to validate 20% of these transcripts. Immunofluorescent analysis of proliferating and tube-forming cells validates at the protein level the morphogenesis-specific expression pattern of 16 of the 217 gene products identified. The transcripts that are selectively up-regulated in tube-forming endothelial cells reveal a temporal expression pattern of genes primarily associated with intracellular trafficking, guided migration, cytoskeletal reorganization, cellular adhesion, and proliferation inhibition. These data show that a sequential upregulation of genes that establish and maintain polarity occurs during migration and morphogenesis of in vitro human endothelial cells undergoing tubulogenesis; some of which may well be effective as novel antiangiogenic drug targets.

  19. Subtractive fuzzy classifier based driver distraction levels classification using EEG.

    PubMed

    Wali, Mousa Kadhim; Murugappan, Murugappan; Ahmad, Badlishah

    2013-09-01

    [Purpose] In earlier studies of driver distraction, researchers classified distraction into two levels (not distracted, and distracted). This study classified four levels of distraction (neutral, low, medium, high). [Subjects and Methods] Fifty Asian subjects (n=50, 43 males, 7 females), age range 20-35 years, who were free from any disease, participated in this study. Wireless EEG signals were recorded by 14 electrodes during four types of distraction stimuli (Global Position Systems (GPS), music player, short message service (SMS), and mental tasks). We derived the amplitude spectrum of three different frequency bands, theta, alpha, and beta of EEG. Then, based on fusion of discrete wavelet packet transforms and fast fourier transform yield, we extracted two features (power spectral density, spectral centroid frequency) of different wavelets (db4, db8, sym8, and coif5). Mean ± SD was calculated and analysis of variance (ANOVA) was performed. A fuzzy inference system classifier was applied to different wavelets using the two extracted features. [Results] The results indicate that the two features of sym8 posses highly significant discrimination across the four levels of distraction, and the best average accuracy achieved by the subtractive fuzzy classifier was 79.21% using the power spectral density feature extracted using the sym8 wavelet. [Conclusion] These findings suggest that EEG signals can be used to monitor distraction level intensity in order to alert drivers to high levels of distraction. PMID:24259914

  20. PSF subtraction for the WFIRST-AFTA coronagraph

    NASA Astrophysics Data System (ADS)

    Ygouf, Marie; Pueyo, Laurent; Zimmerman, Neil T.; Soummer, Remi; Perrin, Marshall D.; Mennesson, Bertrand; Krist, John E.; Vasisht, Gautam; Nemati, Bijan; Macintosh, Bruce

    2016-01-01

    Direct detection and characterization of mature giant or sub-Neptunes exoplanets in the visible require space-based instruments optimized for high-contrast imaging with contrasts of 1e-9. In this context, the Wide-Field Infrared Survey Telescope - Astrophysics Focused Telescope Assets (WFIRST-AFTA) will reach raw contrasts of about 1e-9 to 8e-9 using state-of-the-art starlight suppression and wavefront control techniques. A ten-fold contrast improvement is therefore expected using post-processing techniques to reduce the speckle noise level to a factor of at least 10 lower in order to distinguish 1e-9 planets from speckles. Point spread function (PSF) subtractions on both ground-based and space-based instruments have not yet been demonstrated at such high-contrast levels and we explore new ways of implementing these techniques on AFTA-like simulated images in the presence of deformable mirrors, coronagraph and integral field spectrograph (IFS). In this communication, we cover both the problems of planet detection (investigating new metrics such as the False Positive Probability), and planet characterization (demonstrating accurate spectrum extraction even in the presence of speckles).

  1. Multiplicative and subtractive focal volume engineering in coherent Raman microscopy

    PubMed Central

    Raghunathan, Varun; Potma, Eric Olaf

    2012-01-01

    Rigorous calculations are performed to study the effective reduction of the nonlinear excitation volumes when using phase-only masks to condition the pump and Stokes driving fields. Focal volume reduction was achieved using both a multiplicative operation of the excitation fields as well as a subtractive operation. Using a tunable optical bottle beam for the Stokes field, an effective reduction of the width of the excitation volume by a factor of 1.5 can be achieved in the focal plane. Further reduction of the focal volume introduces a rapid growth of sidelobes, which renders such volumes unsuitable for imaging applications. In addition, phase sensitive detection was found to provide information from selective sub-divisions of the engineered coherent anti-Stokes Raman scattering excitation volume. In the case of isolated nanoparticles, an apparent resolution improvement by a factor of 3 is demonstrated, and it is shown that the size of sub-diffraction-limited particles can be accurately determined using phase sensitive detection. PMID:21045900

  2. SPECKLE NOISE SUBTRACTION AND SUPPRESSION WITH ADAPTIVE OPTICS CORONAGRAPHIC IMAGING

    SciTech Connect

    Ren Deqing; Dou Jiangpei; Zhang Xi; Zhu Yongtian

    2012-07-10

    Future ground-based direct imaging of exoplanets depends critically on high-contrast coronagraph and wave-front manipulation. A coronagraph is designed to remove most of the unaberrated starlight. Because of the wave-front error, which is inherit from the atmospheric turbulence from ground observations, a coronagraph cannot deliver its theoretical performance, and speckle noise will limit the high-contrast imaging performance. Recently, extreme adaptive optics, which can deliver an extremely high Strehl ratio, is being developed for such a challenging mission. In this publication, we show that barely taking a long-exposure image does not provide much gain for coronagraphic imaging with adaptive optics. We further discuss a speckle subtraction and suppression technique that fully takes advantage of the high contrast provided by the coronagraph, as well as the wave front corrected by the adaptive optics. This technique works well for coronagraphic imaging with conventional adaptive optics with a moderate Strehl ratio, as well as for extreme adaptive optics with a high Strehl ratio. We show how to substrate and suppress speckle noise efficiently up to the third order, which is critical for future ground-based high-contrast imaging. Numerical simulations are conducted to fully demonstrate this technique.

  3. Temporal subtraction in chest radiography: Mutual information as a measure of image quality

    SciTech Connect

    Armato, Samuel G. III; Sensakovic, William F.; Passen, Samantha J.; Engelmann, Roger; MacMahon, Heber

    2009-12-15

    Purpose: Temporal subtraction is used to detect the interval change in chest radiographs and aid radiologists in patient diagnosis. This method registers two temporally different images by geometrically warping the lung region, or ''lung mask,'' of a previous radiographic image to align with the current image. The gray levels of every pixel in the current image are subtracted from the gray levels of the corresponding pixels in the warped previous image to form a temporal subtraction image. While temporal subtraction images effectively enhance areas of pathologic change, misregistration of the images can mislead radiologists by obscuring the interval change or by creating artifacts that mimic change. The purpose of this study was to investigate the utility of mutual information computed between two registered radiographic chest images as a metric for distinguishing between clinically acceptable and clinically unacceptable temporal subtraction images.Methods: A radiologist subjectively rated the image quality of 138 temporal subtraction images using a 1 (poor) to 5 (excellent) scale. To objectively assess the registration accuracy depicted in the temporal subtraction images, which is the main factor that affects the quality of these images, mutual information was computed on the two constituent registered images prior to their subtraction to generate a temporal subtraction image. Mutual information measures the joint entropy of the current image and the warped previous image, yielding a higher value when the gray levels of spatially matched pixels in each image are consistent. Mutual information values were correlated with the radiologist's subjective ratings. To improve this correlation, mutual information was computed from a spatially limited lung mask, which was cropped from the bottom by 10%-60%. Additionally, the number of gray-level values used in the joint entropy histogram was varied. The ability of mutual information to predict the clinical acceptability of

  4. Insect Wing Displacement Measurement Using Digital Holography

    SciTech Connect

    Aguayo, Daniel D.; Mendoza Santoyo, Fernando; Torre I, Manuel H. de la; Caloca Mendez, Cristian I.

    2008-04-15

    Insects in flight have been studied with optical non destructive techniques with the purpose of using meaningful results in aerodynamics. With the availability of high resolution and large dynamic range CCD sensors the so called interferometric digital holographic technique was used to measure the surface displacement of in flight insect wings, such as butterflies. The wings were illuminated with a continuous wave Verdi laser at 532 nm, and observed with a CCD Pixelfly camera that acquire images at a rate of 11.5 frames per second at a resolution of 1392x1024 pixels and 12 Bit dynamic range. At this frame rate digital holograms of the wings were captured and processed in the usual manner, namely, each individual hologram is Fourier processed in order to find the amplitude and phase corresponding to the digital hologram. The wings displacement is obtained when subtraction between two digital holograms is performed for two different wings position, a feature applied to all consecutive frames recorded. The result of subtracting is seen as a wrapped phase fringe pattern directly related to the wing displacement. The experimental data for different butterfly flying conditions and exposure times are shown as wire mesh plots in a movie of the wings displacement.

  5. Comparing the Efficacy of Intravenous Acetaminophen and Intravenous Meperidine in Pain Relief After Outpatient Urological Surgery

    PubMed Central

    Kolahdouzan, Khosro; Eydi, Mahmood; Mohammadipour Anvari, Hassan; Golzari, Samad EJ; Abri, Reyhaneh; Ghojazadeh, Morteza; Ojaghihaghighi, Seyed Hossein

    2014-01-01

    Background: Pain relief after surgery is an essential component of postoperative care. Objectives: The purpose of this study was to compare the efficacy of intravenous acetaminophen and intravenous meperidine in pain relief after outpatient urological surgery. Patients and Methods: In a prospective, randomized, double-blind clinical trial, 100 outpatients of urological surgery were studied in two groups of acetaminophen (A) and meperidine (M). Patients in group A received 1g of acetaminophen in 100 mL saline within 15 minutes and patients in group M received a single intravenous injection of meperidine 0.5 mg/kg, 15 minutes prior to the end of operation. Postoperative pain was recorded using visual analog scale (VAS). Vital signs, nausea, vomiting, dizziness and respiratory depressions were compared between the two groups. Results: Pain severity in patients treated with intravenous acetaminophen six hours after the operation within one-hour interval was significantly lower than meperidine group (P < 0.0001). Ninety patients in the meperidine group and five patients in the acetaminophen group required additional doses of analgesics. Nausea was significantly lower in acetaminophen group than meperidine group. Conclusions: Intravenous acetaminophen reduced pain following outpatient urological surgery more significantly than meperidine. PMID:25798377

  6. Digital Natives or Digital Tribes?

    ERIC Educational Resources Information Center

    Watson, Ian Robert

    2013-01-01

    This research builds upon the discourse surrounding digital natives. A literature review into the digital native phenomena was undertaken and found that researchers are beginning to identify the digital native as not one cohesive group but of individuals influenced by other factors. Primary research by means of questionnaire survey of technologies…

  7. Contrast-Enhanced Digital Mammography and Angiogenesis

    SciTech Connect

    Rosado-Mendez, I.; Palma, B. A.; Villasenor, Y.; Benitez-Bribiesca, L.; Brandan, M. E.

    2007-11-26

    Angiogenesis could be a means for pouring contrast media around tumors. In this work, optimization of radiological parameters for contrast-enhanced subtraction techniques in mammography has been performed. A modification of Lemacks' analytical formalism was implemented to model the X-ray absorption in the breast with contrast medium and detection by a digital image receptor. Preliminary results of signal-to-noise ratio analysis show the advantage of subtracting two images taken at different energies, one prior and one posterior to the injection of contrast medium. Preliminary experimental results using a custom-made phantom have shown good agreement with calculations. A proposal is presented for the clinical application of the optimized technique, which aims at finding correlations between angiogenesis indicators and dynamic variables of contrast medium uptake.

  8. The "ups" and "downs" in Using Subtractive Cloning Techniques to Isolate Regulated Genes in Fish.

    PubMed

    Goetz, Frederick William

    2003-12-01

    Over the last decade, subtractive cloning approaches have been used extensively to isolate genes that are up- or down-regulated under various conditions. These techniques have provided the foundation for many subsequent studies concerning gene function and regulation and, as such, have been valuable tools for many biological fields. Over the past 10 years, we have used different subtractive cloning approaches to isolate genes in fish that are regulated in relation to hormonal stimulation or the stage of ovarian maturation. These include conventional cDNA subtraction followed by library screening, differential display PCR, suppression subtraction hybridization, and more recently, iterative PCR subtraction. We continue to use these techniques for the isolation of new genes involved in physiological processes in fish and bivalve molluscs. Examples that illustrate the use of these different subtractive cloning techniques are described, including where possible the advantages and disadvantages of each. In addition, the use of ancillary methods (e.g., "Reverse Northerns") to facilitate the use of these subtractive approaches are discussed. PMID:21680477

  9. Voxel significance mapping using local image variances in subtraction ictal SPET.

    PubMed

    Brinkmann, B H; O'Brien, T J; Webster, D B; Mullan, B P; Robins, P D; Robb, R A

    2000-06-01

    Subtraction ictal SPET co-registered to MRI (SISCOM) has been shown to aid epileptogenic localization and improve surgical outcome in partial epilepsy patients. This paper reports a method of identifying significant areas of epileptogenic activation in the SISCOM subtraction image, taking into account normal variation between sequential 99Tcm-ethyl cysteinate diethylester SPET scans of single individuals, and attempts to assess the clinical value of statistical mapping in subtraction SPET. Non-linear inter-subject registration is used to combine a group of subtraction images into a common anatomical framework. A map of the pixel intensity standard deviation values in the subtraction images is created, and this map is non-linearly registered to a patient's SISCOM subtraction image. Pixels in the patient subtraction image were then evaluated based upon the statistical characteristics of corresponding pixels in the atlas. SISCOM images created with the voxel variance method were rated higher in quality than the conventional image variance method in 15 patients. No difference in localization rate was observed between the voxel variance mapping and image variance methods. The voxel significance mapping method was shown to improve the quality of clinical SISCOM images. PMID:10894564

  10. A Wireless FSCV Monitoring IC With Analog Background Subtraction and UWB Telemetry.

    PubMed

    Dorta-Quiñones, Carlos I; Wang, Xiao Y; Dokania, Rajeev K; Gailey, Alycia; Lindau, Manfred; Apsel, Alyssa B

    2016-04-01

    A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5- mm(2) chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pA(rms) and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm(2), weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV. PMID:26057983

  11. Enhanced angular domain optical imaging by background scattered light subtraction from a deviated laser source

    NASA Astrophysics Data System (ADS)

    Vasefi, Fartash; Chapman, Glenn H.; Chan, Paulman; Kaminska, Bozena; Pfeiffer, Nick

    2008-02-01

    Imaging structures within a turbid medium using Angular Domain Imaging (ADI) employs angular filter array aligned to a laser source to separate ballistic and quasi-ballistic photons from the highly scattered light by means of angular filtration. The angular filter consists of a high aspect ratio linear array of silicon micromachined tunnels, 51 micron wide by 10mm long with a 0.29 degree acceptance angle. At heavy scattering ratios of >1E7 image detectability declines due to the non-uniform scattered background light fraction still within the acceptance angle. This scattered signal can be separated out by introducing a wedge prism to deviate the laser source where it enters the medium by an angle slightly larger than the acceptance angle. This creates a second image consisting of pure scattering photons with the filtration characteristics of the angular filter, and a pixel by pixel correspondence to the fully scattered illumination emitted from the medium. Experiments used an 808 nm laser diode, collimated to an 8×1 mm line of light, entering a 5cm thick medium with a scattering ratio of > 1E6, with a wedge prism creating a 0.44 degree deviation. Digitally subtracting the deviated scattered signal from the original image significantly reduced the scattered background and enhanced image contrast. We can have about images at least 40 times more of our previous scattering limits. Depending on test phantom object location, the contrast level can be increased from 4% of the total dynamic range to over 50% which results in higher definition and visibility of our micro-scale test structures in the turbid medium.

  12. A Wireless FSCV Monitoring IC with Analog Background Subtraction and UWB Telemetry

    PubMed Central

    Dorta-Quiñones, Carlos I.; Wang, Xiao Y.; Dokania, Rajeev K.; Gailey, Alycia; Lindau, Manfred; Apsel, Alyssa B.

    2015-01-01

    A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5-mm2 chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pArms and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm2, weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV. PMID:26057983

  13. Redefining the Whole: Common Errors in Elementary Preservice Teachers' Self-Authored Word Problems for Fraction Subtraction

    ERIC Educational Resources Information Center

    Dixon, Juli K.; Andreasen, Janet B.; Avila, Cheryl L.; Bawatneh, Zyad; Deichert, Deana L.; Howse, Tashana D.; Turner, Mercedes Sotillo

    2014-01-01

    A goal of this study was to examine elementary preservice teachers' (PSTs) ability to contextualize and decontextualize fraction subtraction by asking them to write word problems to represent fraction subtraction expressions and to choose prewritten word problems to support given fraction subtraction expressions. Three themes emerged from the…

  14. Ending up with Less: The Role of Working Memory in Solving Simple Subtraction Problems with Positive and Negative Answers

    ERIC Educational Resources Information Center

    Robert, Nicole D.; LeFevre, Jo-Anne

    2013-01-01

    Does solving subtraction problems with negative answers (e.g., 5-14) require different cognitive processes than solving problems with positive answers (e.g., 14-5)? In a dual-task experiment, young adults (N=39) combined subtraction with two working memory tasks, verbal memory and visual-spatial memory. All of the subtraction problems required…

  15. Discovery of estrogen-responsive genes using an improved method which combines subtractive hybridization and PCR.

    PubMed Central

    Liu, W; Su, W; Roberts, T M

    1998-01-01

    Here we describe a reliable method for isolating genes that are differentially expressed in two cell populations. The method is a combination of subtractive hybridization and PCR. Among many improvements to previously described methods is the incorporation of a new technology into the procedure which sterilizes(inactivates) PCR amplicons, and thereby overcomes the limitation of similar procedures. To test this improved method, we conducted a search for estrogen-responsive genes. Estrogen-regulated genes dominated the subtracted libraries after four rounds of subtractive hybridizations. Four estrogen-regulated genes were identified from the initial screening. PMID:9671829

  16. On the subtraction method for in-situ reflection and diffusion coefficient measurements.

    PubMed

    Robinson, Philip; Xiang, Ning

    2010-03-01

    The subtraction method is a technique critical to several important acoustic measurements. It involves subtracting a reference measurement including only direct sound from one with direct sound and a reflection, to isolate the reflection. The process is very sensitive to environmental conditions, such as changes in temperature, air movement, and microphone positioning. These variations cause small time differences between the reference and reflection measurements, which prevent complete subtraction of the direct sound; the residual direct sound then pollutes analysis of the isolated reflection. This work evaluates methods to compensate for differences to achieve minimal interference from the residual direct sound. PMID:20329814

  17. A clinical audit of thallium-technetium subtraction parathyroid scans.

    PubMed Central

    Samanta, A.; Wilson, B.; Iqbal, J.; Burden, A. C.; Walls, J.; Cosgriff, P.

    1990-01-01

    Eighty six consecutive thallium-technetium subtraction parathyroid scans performed over a three year period for hypercalcaemia have been evaluated. Twelve had chronic renal failure, 11 had hypercalcaemia due to non-hyperparathyroid causes and in 10 the imaging study was technically inadequate. The remaining 53 technically adequate studies performed for hypercalcaemia clinically thought to be possibly due to hyperparathyroidism have been analysed. Of 20 (38%) positive scans, 13 came to surgery (10 correctly localized parathyroid adenomas, 2 with multiple gland hyperplasia, and 1 papillary carcinoma of the thyroid). Of 33 (62%) negative scans, 9 had surgical exploration on the basis of strong clinical grounds and all had parathyroid adenomas. Multiple biochemical parameters have been assessed in relation to a positive outcome on scan. The adjusted calcium-phosphate product and the ratio of the adjusted calcium-phosphate product to creatinine (Ca x P/Cr) were both significantly lower in the scan positive group (P less than 0.01). The scan positive group had a significantly higher mean level of PTH (P less than 0.001) and lower mean level of phosphate (P less than 0.001). The present experience shows that parathyroid imaging is useful in localizing parathyroid adenomas in 50% of cases (10 out of 19). This figure is at the lower end of the range of previously published results. It is less effective in demonstrating multiple gland hyperplasia. The decision as to whether to undertake surgical exploration when the scan is negative has been based successfully on clinical judgement. We feel that an analysis of this nature is important, as it gives insights into the practical relevance of parathyroid imaging in the context of routine clinical work. PMID:2170959

  18. Post-radiation memory correction using differential subtraction for Phenix

    SciTech Connect

    Britton, C.L. Jr.; Wintenberg, A.L.; Womac, M.; Kennedy, E.J.; Smith, R.S.; Young, G.R.; Awes, T.C.

    1995-06-01

    In colliders such as RHIC, the radiation levels are well below those of colliders such as LHC. The problem is that there can be enough radiation at the inner detector (Multiplicity-Vertex Detector or MVD) to significantly affect a low-priced, nonradiation-hard CMOS process. If the radiation affects the entire analog memory in a uniform fashion, then a real-time correction should be able to be performed to correct any changes seen in the memory and also the induced correlated noise from detector pickup thus precluding the need for a more expensive rad-hard process. This paper will present testing on memories fabricated in a `soft` process and exposed to ionizing radiation. We used a single pipeline as a reference to be subtracted in a cell-by-cell basis from each pipe during read out and investigated the spatial effects of using different pipes for the reference. Use of this method reduced the noise which was common to all pipes (common-mode noise) and thus reduced both common-mode input noise and pattern noise generated from address lines being exercised on the AMU. The correlation across the memories (6-, 8-, and 16-channel AMUs fabricated in the Orbit 1.2{mu} CMOS process) vs. radiation dose was found to be quite good. Both pre-and post-radiation results are presented on systems designed for PHENIX and WA98 at CERN as well as measured results on the minimization of the effects of injected systematic noise.

  19. WAXS fat subtraction model to estimate differential linear scattering coefficients of fatless breast tissue: Phantom materials evaluation

    SciTech Connect

    Tang, Robert Y.; Laamanen, Curtis McDonald, Nancy; LeClair, Robert J.

    2014-05-15

    measure μ{sub s} of homogeneous samples was quantitatively accurate. Simple WAXS models predicted the probabilities for specific x-ray scattering to occur from heterogeneous biopsies. The fat subtraction model can allow μ{sub s} signals of breast cancer and fibroglandular tissue to be compared without the effects of fat provided there is an independent measurement of the fat volume fraction ν{sub f}. Future work will consist of devising a quantitative x-ray digital imaging method to estimate ν{sub f} in ex vivo breast samples.

  20. In vivo comparison of tantalum, tungsten, and bismuth enteric contrast agents to complement intravenous iodine for double-contrast dual-energy CT of the bowel.

    PubMed

    Rathnayake, Samira; Mongan, John; Torres, Andrew S; Colborn, Robert; Gao, Dong-Wei; Yeh, Benjamin M; Fu, Yanjun

    2016-07-01

    To assess the ability of dual-energy CT (DECT) to separate intravenous contrast of bowel wall from intraluminal contrast, we scanned 16 rabbits on a clinical DECT scanner: n = 3 using only iodinated intravenous contrast, and n = 13 double-contrast enhanced scans using iodinated intravenous contrast and experimental enteric non-iodinated contrast agents in the bowel lumen (five bismuth, four tungsten, and four tantalum based). Representative image pairs from conventional CT images and DECT iodine density maps of small bowel (116 pairs from 232 images) were viewed by four abdominal imaging attending radiologists to independently score each comparison pair on a visual analog scale (-100 to +100%) for (1) preference in small bowel wall visualization and (2) preference in completeness of intraluminal enteric contrast subtraction. Median small bowel wall visualization was scored 39 and 42 percentage points (95% CI 30-44% and 36-45%, both p < 0.001) higher for double-contrast DECT than for conventional CT with enteric tungsten and tantalum contrast, respectively. Median small bowel wall visualization for double-contrast DECT was scored 29 and 35 percentage points (95% CI 20-35% and 33-39%, both p < 0.001) higher with enteric tungsten and tantalum, respectively, than with bismuth contrast. Median completeness of intraluminal enteric contrast subtraction in double-contrast DECT iodine density maps was scored 28 and 29 percentage points (95% CI 15-31% and 28-33%, both p < 0.001) higher with enteric tungsten and tantalum, respectively, than with bismuth contrast. Results suggest that in vivo double-contrast DECT with iodinated intravenous and either tantalum- or tungsten-based enteric contrast provides better visualization of small bowel than conventional CT. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26892945

  1. Scalable computer architecture for digital vascular systems

    NASA Astrophysics Data System (ADS)

    Goddard, Iain; Chao, Hui; Skalabrin, Mark

    1998-06-01

    Digital vascular computer systems are used for radiology and fluoroscopy (R/F), angiography, and cardiac applications. In the United States alone, about 26 million procedures of these types are performed annually: about 81% R/F, 11% cardiac, and 8% angiography. Digital vascular systems have a very wide range of performance requirements, especially in terms of data rates. In addition, new features are added over time as they are shown to be clinically efficacious. Application-specific processing modes such as roadmapping, peak opacification, and bolus chasing are particular to some vascular systems. New algorithms continue to be developed and proven, such as Cox and deJager's precise registration methods for masks and live images in digital subtraction angiography. A computer architecture must have high scalability and reconfigurability to meet the needs of this modality. Ideally, the architecture could also serve as the basis for a nonvascular R/F system.

  2. Intravenous infusions in chronic pain management.

    PubMed

    Kosharskyy, Boleslav; Almonte, Wilson; Shaparin, Naum; Pappagallo, Marco; Smith, Howard

    2013-01-01

    In the United States, millions of Americans are affected by chronic pain, which adds heavily to national rates of morbidity, mortality, and disability, with an ever-increasing prevalence. According to a 2011 report titled Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, and Research by the Institute of Medicine of the National Academies, pain not only exacts its toll on people's lives but also on the economy with an estimated annual economic cost of at least $560 - 635 billion in health care costs and the cost of lost productivity attributed to chronic pain. Intravenous infusions of certain pharmacologic agents have been known to provide substantial pain relief in patients with various chronic painful conditions. Some of these infusions are better, and although not necessarily the first therapeutic choice, have been widely used and extensively studied. The others show promise, however are in need of further investigations. This article will focus on non-opiate intravenous infusions that have been utilized for chronic painful disorders such as fibromyalgia, neuropathic pain, phantom limb pain, post-herpetic neuralgia, complex regional pain syndromes (CRPS), diabetic neuropathy, and central pain related to stroke or spinal cord injuries. The management of patients with chronic pain conditions is challenging and continues to evolve as new treatment modalities are explored and tested. The following intravenous infusions used to treat the aforementioned chronic pain conditions will be reviewed: lidocaine, ketamine, phentolamine, dexmedetomidine, and bisphosphonates. This overview is intended to familiarize the practitioner with the variety of infusions for patients with chronic pain. It will not, however, be able to provide guidelines for their use due to the lack of sufficient evidence. PMID:23703410

  3. Intravenous immune globulin in chronic lymphocytic leukaemia.

    PubMed Central

    Gamm, H; Huber, C; Chapel, H; Lee, M; Ries, F; Dicato, M A

    1994-01-01

    The most common complication of chronic lymphocytic leukaemia (CLL) is infection, which occurs mainly in advanced stages of disease or in those patients with hypogammaglobulinaemia. Intravenous immune globulin (IVIG) has been shown to be a useful prophylactic therapy against infections in such patients. A randomized, double-blind study on 36 patients receiving either 500 mg/kg or 250 mg/kg IVIG every 4 weeks was undertaken to determine the dose regimen required. There was no significant difference in the two treatment groups and we found that CLL patients were equally protected with low-dose IVIG. PMID:8033428

  4. Cystic fibrosis, intravenous antibiotics, and home therapy.

    PubMed

    Hammond, L J; Caldwell, S; Campbell, P W

    1991-01-01

    The survival rate of patients with cystic fibrosis has improved considerably in the last 20 years. Although not all of the factors accounting for this change are understood, aggressive nutritional management and treatment of pulmonary exacerbations certainly play a role. Home intravenous (IV) antibiotic delivery for pulmonary exacerbation has proved to be as effective as hospital treatment and offers significant advantages to the patient and family. This article examines the microbiology of pulmonary infections in patients with cystic fibrosis, as well as antimicrobial therapy, methods of IV administration, home IV therapy, and the nurse practitioner's role in this home program in the future. PMID:1990112

  5. Advances in Pediatric Intravenous Iron Therapy.

    PubMed

    Mantadakis, Elpis

    2016-01-01

    Iron deficiency anemia (IDA) continues to be very common worldwide. Intravenous (IV) iron is an infrequently used therapeutic option in children with IDA despite numerous studies in adults and several small but notable pediatric studies showing efficacy and safety. Presently, the availability of newer IV iron products allows for replacement of the total iron deficit at a single setting. These products appear safer compared to the high molecular weight iron dextrans of the past. Herein, we review the medical literature and suggest that front line use of IV iron should be strongly considered in diseases associated with IDA in children. PMID:26376214

  6. Intravenous paracetamol in patients with renal colic.

    PubMed

    Morgan, Sara

    2011-02-01

    Non-steroidal anti-inflammatory drugs and opioids have been the mainstay of pain relief in patients with renal colic, but both have side effects. Research on the efficacy of intravenous (IV) paracetamol shows that it is comparable to morphine, diclofenac and ketoralac. This article discusses the role of IV paracetamol for patients with this condition. It examines the effectiveness, mechanism of action and pharmacokinetics of IV paracetamol, and suggests that non-clinical prescribers can use the method to relieve patients' pain quickly. PMID:21384782

  7. A theoretical comparison of x-ray angiographic image quality using energy-dependent and conventional subtraction methods

    SciTech Connect

    Tanguay, Jesse; Kim, Ho Kyung; Cunningham, Ian A.

    2012-01-15

    Purpose: X-ray digital subtraction angiography (DSA) is widely used for vascular imaging. However, the need to subtract a mask image can result in motion artifacts and compromised image quality. The current interest in energy-resolving photon-counting (EPC) detectors offers the promise of eliminating motion artifacts and other advanced applications using a single exposure. The authors describe a method of assessing the iodine signal-to-noise ratio (SNR) that may be achieved with energy-resolved angiography (ERA) to enable a direct comparison with other approaches including DSA and dual-energy angiography for the same patient exposure. Methods: A linearized noise-propagation approach, combined with linear expressions of dual-energy and energy-resolved imaging, is used to describe the iodine SNR. The results were validated by a Monte Carlo calculation for all three approaches and compared visually for dual-energy and DSA imaging using a simple angiographic phantom with a CsI-based flat-panel detector. Results: The linearized SNR calculations show excellent agreement with Monte Carlo results. While dual-energy methods require an increased tube heat load of 2x to 4x compared to DSA, and photon-counting detectors are not yet ready for angiographic imaging, the available iodine SNR for both methods as tested is within 10% of that of conventional DSA for the same patient exposure over a wide range of patient thicknesses and iodine concentrations. Conclusions: While the energy-based methods are not necessarily optimized and further improvements are likely, the linearized noise-propagation analysis provides the theoretical framework of a level playing field for optimization studies and comparison with conventional DSA. It is concluded that both dual-energy and photon-counting approaches have the potential to provide similar angiographic image quality to DSA.

  8. Spectral subtraction-based speech enhancement for cochlear implant patients in background noise

    NASA Astrophysics Data System (ADS)

    Yang, Li-Ping; Fu, Qian-Jie

    2005-03-01

    A single-channel speech enhancement algorithm utilizing speech pause detection and nonlinear spectral subtraction is proposed for cochlear implant patients in the present study. The spectral subtraction algorithm estimates the short-time spectral magnitude of speech by subtracting the estimated noise spectral magnitude from the noisy speech spectral magnitude. The artifacts produced by spectral subtraction (such as ``musical noise'') were significantly reduced by combining variance-reduced gain function and spectral flooring. Sentence recognition by seven cochlear implant subjects was tested under different noisy listening conditions (speech-shaped noise and 6-talker speech babble at +9, +6, +3, and 0 dB SNR) with and without the speech enhancement algorithm. For speech-shaped noise, performance for all subjects at all SNRs was significantly improved by the speech enhancement algorithm; for speech babble, performance was only modestly improved. The results suggest that the proposed speech enhancement algorithm may be beneficial for implant users in noisy listening. .

  9. Number words in young children's conceptual and procedural knowledge of addition, subtraction and inversion.

    PubMed

    Canobi, Katherine H; Bethune, Narelle E

    2008-09-01

    Three studies addressed children's arithmetic. First, 50 3- to 5-year-olds judged physical demonstrations of addition, subtraction and inversion, with and without number words. Second, 20 3- to 4-year-olds made equivalence judgments of additions and subtractions. Third, 60 4- to 6-year-olds solved addition, subtraction and inversion problems that varied according to the inclusion of concrete referents and number words. The results indicate that number words play a different role in conceptual and procedural development. Children have strong addition and subtraction concepts before they can translate the physical effects of these operations into number words. However, using number words does not detract from their calculation procedures. Moreover, consistent with iterative relations between conceptual and procedural development, the results suggest that inversion acquisition depends on children's calculation procedures and that inversion understanding influences these procedures. PMID:18621361

  10. Digital metamaterials

    NASA Astrophysics Data System (ADS)

    Della Giovampaola, Cristian; Engheta, Nader

    2014-12-01

    Balancing complexity and simplicity has played an important role in the development of many fields in science and engineering. One of the well-known and powerful examples of such balance can be found in Boolean algebra and its impact on the birth of digital electronics and the digital information age. The simplicity of using only two numbers, ‘0’ and ‘1’, in a binary system for describing an arbitrary quantity made the fields of digital electronics and digital signal processing powerful and ubiquitous. Here, inspired by the binary concept, we propose to develop the notion of digital metamaterials. Specifically, we investigate how one can synthesize an electromagnetic metamaterial with a desired permittivity, using as building blocks only two elemental materials, which we call ‘metamaterial bits’, with two distinct permittivity functions. We demonstrate, analytically and numerically, how proper spatial mixtures of such metamaterial bits lead to elemental ‘metamaterial bytes’ with effective material parameters that are different from the parameters of the metamaterial bits. We then apply this methodology to several design examples of optical elements, such as digital convex lenses, flat graded-index digital lenses, digital constructs for epsilon-near-zero (ENZ) supercoupling and digital hyperlenses, thus highlighting the power and simplicity of the methodology.

  11. Digital metamaterials.

    PubMed

    Della Giovampaola, Cristian; Engheta, Nader

    2014-12-01

    Balancing complexity and simplicity has played an important role in the development of many fields in science and engineering. One of the well-known and powerful examples of such balance can be found in Boolean algebra and its impact on the birth of digital electronics and the digital information age. The simplicity of using only two numbers, '0' and '1', in a binary system for describing an arbitrary quantity made the fields of digital electronics and digital signal processing powerful and ubiquitous. Here, inspired by the binary concept, we propose to develop the notion of digital metamaterials. Specifically, we investigate how one can synthesize an electromagnetic metamaterial with a desired permittivity, using as building blocks only two elemental materials, which we call 'metamaterial bits', with two distinct permittivity functions. We demonstrate, analytically and numerically, how proper spatial mixtures of such metamaterial bits lead to elemental 'metamaterial bytes' with effective material parameters that are different from the parameters of the metamaterial bits. We then apply this methodology to several design examples of optical elements, such as digital convex lenses, flat graded-index digital lenses, digital constructs for epsilon-near-zero (ENZ) supercoupling and digital hyperlenses, thus highlighting the power and simplicity of the methodology. PMID:25218061

  12. Behavioural evidence for sex differences in the overlap between subtraction and multiplication.

    PubMed

    Pletzer, Belinda; Moeller, Korbinian; Scheuringer, Andrea; Domahs, Frank; Kerschbaum, Hubert H; Nuerk, Hans-Christoph

    2016-05-01

    The present study aims to identify factors that may influence the dissociability of number magnitude processing and arithmetic fact retrieval at the behavioural level. To that end, we assessed both subtraction and multiplication performance in a within-subject approach and evaluated the interdependence of unit-decade integration measures on the one hand as well as sex differences in the interdependence of performance measures on the other hand. We found that subtraction items requiring borrowing (e.g. 53-29 = 24, 3 < 9) are more error prone than subtraction items not requiring borrowing (e.g. 59-23 = 34, 9 > 3), thereby demonstrating a borrowing effect, which has been suggested as a measure of unit-decade integration in subtraction. Furthermore, we observed that multiplication items with decade-consistent distractors (e.g. 6 × 4 = 28 instead of 24) are more error prone that multiplication items with decade-inconsistent distractors (e.g. 6 × 4 = 30 instead of 24), thereby demonstrating a decade-consistency effect, which has been suggested as a measure of unit-decade integration in simple multiplication. However, the borrowing effect in subtraction was not correlated with the effect of decade consistency in simple multiplication in either men or women. This indicates that unit-decade integration arises from different systems in subtraction and multiplication. Nevertheless, men outperformed women not only in subtraction, but also in multiplication. Furthermore, subtraction and multiplication performance on correct solution probes were correlated in women, but unrelated in men. Thus, the view of differential systems for number magnitude processing and arithmetic fact retrieval may not be universal across sexes. PMID:26861245

  13. Photon-number-resolved detection of photon-subtracted thermal light.

    PubMed

    Zhai, Yanhua; Becerra, Francisco E; Glebov, Boris L; Wen, Jianming; Lita, Adriana E; Calkins, Brice; Gerrits, Thomas; Fan, Jingyun; Nam, Sae Woo; Migdall, Alan

    2013-07-01

    We examine the photon statistics of photon-subtracted thermal light using photon-number-resolved detection. We demonstrate experimentally that the photon number distribution transforms from a Bose-Einstein distribution to a Poisson distribution as the number of subtracted photons increases. We also show that second- and higher-order photon correlation functions can be directly determined from the photon-number-resolved detection measurements of a single optical beam. PMID:23811867

  14. The Human Experience with Intravenous Levodopa

    PubMed Central

    Siddiqi, Shan H.; Abraham, Natalia K.; Geiger, Christopher L.; Karimi, Morvarid; Perlmutter, Joel S.; Black, Kevin J.

    2016-01-01

    Objective: To compile a comprehensive summary of published human experience with levodopa given intravenously, with a focus on information required by regulatory agencies. Background: While safe intravenous (IV) use of levodopa has been documented for over 50 years, regulatory supervision for pharmaceuticals given by a route other than that approved by the U.S. Food and Drug Administration (FDA) has become increasingly cautious. If delivering a drug by an alternate route raises the risk of adverse events, an investigational new drug (IND) application is required, including a comprehensive review of toxicity data. Methods: Over 200 articles referring to IV levodopa were examined for details of administration, pharmacokinetics, benefit, and side effects. Results: We identified 142 original reports describing IVLD use in humans, beginning with psychiatric research in 1959–1960 before the development of peripheral decarboxylase inhibitors. At least 2760 subjects have received IV levodopa, and reported outcomes include parkinsonian signs, sleep variables, hormone levels, hemodynamics, CSF amino acid composition, regional cerebral blood flow, cognition, perception and complex behavior. Mean pharmacokinetic variables were summarized for 49 healthy subjects and 190 with Parkinson's disease. Side effects were those expected from clinical experience with oral levodopa and dopamine agonists. No articles reported deaths or induction of psychosis. Conclusion: At least 2760 patients have received IV levodopa with a safety profile comparable to that seen with oral administration. PMID:26779024

  15. Panlobular emphysema in young intravenous Ritalin abusers

    SciTech Connect

    Schmidt, R.A.; Glenny, R.W.; Godwin, J.D.; Hampson, N.B.; Cantino, M.E.; Reichenbach, D.D. )

    1991-03-01

    We studied a distinctive group of young intravenous Ritalin abusers with profound obstructive lung disease. Clinically, they seemed to have severe emphysema, but the pathologic basis of their symptoms had not been investigated previously. Seven patients have died and been autopsied: in four, the lungs were fixed, inflated, dried, and examined in detail radiologically, grossly, microscopically, and by electron probe X-ray microanalysis. All seven patients had severe panlobular (panacinar) emphysema that tended to be more severe in the lower lung zones and that was associated with microscopic talc granulomas. Vascular involvement by talc granulomas was variable, but significant interstitial fibrosis was not present. Five patients were tested for alpha-1-antitrypsin deficiency and found to be normal, as were six similar living patients. These findings indicate that some intravenous drug abusers develop emphysema that clinically, radiologically, and pathologically resembles that caused by alpha-1-antitrypsin deficiency but which must have a different pathogenesis. Talc from the Ritalin tablets may be important, but the mechanism remains to be elucidated.

  16. Methylprednisolone pharmacokinetics after intravenous and oral administration.

    PubMed Central

    Al-Habet, S M; Rogers, H J

    1989-01-01

    1. The pharmacokinetics of methylprednisolone (MP) were studied in five normal subjects following intravenous doses of 20, 40 and 80 mg methylprednisolone sodium succinate (MPSS) and an oral dose of 20 mg methylprednisolone as 4 x 5 mg tablets. Plasma concentrations of MP and MPSS were measured by both high performance thin layer (h.p.t.l.c.) and high pressure liquid chromatography (h.p.l.c.). 2. The mean values (+/- s.d.) of half-life, mean residence time (MRT), systemic clearance (CL) and volume of distribution at steady state (Vss) of MP following intravenous administration were 1.93 +/- 0.35 h, 3.50 +/- 1.01 h, 0.45 +/- 0.12 lh-1 kg-1 and 1.5 +/- 0.63 1 kg-1, respectively. There was no evidence of dose-related changes in these values. The plasma MP concentration-time curves were superimposable when normalized for dose. 3. The bioavailability of methylprednisolone from the 20 mg tablet was 0.82 +/- 0.11 (s.d.). 4. In vivo hydrolysis of MPSS was rapid with a half-life of 4.14 +/- 1.62 (s.d.) min, and was independent of dose. In contrast, in vitro hydrolysis in plasma, whole blood and red blood cells was slow; the process continuing for more than 7 days. Sodium fluoride did not prevent the hydrolysis of MPSS. PMID:2655680

  17. Efficacy of Intravenous Immunoglobulin in Neurological Diseases.

    PubMed

    Lünemann, Jan D; Quast, Isaak; Dalakas, Marinos C

    2016-01-01

    Owing to its anti-inflammatory efficacy in various autoimmune disease conditions, intravenous immunoglobulin (IVIG)-pooled IgG obtained from the plasma of several thousands individuals-has been used for nearly three decades and is proving to be efficient in a growing number of neurological diseases. IVIG therapy has been firmly established for the treatment of Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, and multifocal motor neuropathy, either as first-line therapy or adjunctive treatment. IVIG is also recommended as rescue therapy in patients with worsening myasthenia gravis and is beneficial as a second-line therapy for dermatomyositis and stiff-person syndrome. Subcutaneous rather than intravenous administration of IgG is gaining momentum because of its effectiveness in patients with primary immunodeficiency and the ease with which it can be administered independently from hospital-based infusions. The demand for IVIG therapy is growing, resulting in rising costs and supply shortages. Strategies to replace IVIG with recombinant products have been developed based on proposed mechanisms that confer the anti-inflammatory activity of IVIG, but their efficacy has not been tested in clinical trials. This review covers new developments in the immunobiology and clinical applications of IVIG in neurological diseases. PMID:26400261

  18. Young children's use of derived fact strategies for addition and subtraction

    PubMed Central

    Dowker, Ann

    2014-01-01

    Forty-four children between 6;0 and 7;11 took part in a study of derived fact strategy use. They were assigned to addition and subtraction levels on the basis of calculation pretests. They were then given Dowker's (1998) test of derived fact strategies in addition, involving strategies based on the Identity, Commutativity, Addend +1, Addend −1, and addition/subtraction Inverse principles; and test of derived fact strategies in subtraction, involving strategies based on the Identity, Minuend +1, Minuend −1, Subtrahend +1, Subtrahend −1, Complement and addition/subtraction Inverse principles. The exact arithmetic problems given varied according to the child's previously assessed calculation level and were selected to be just a little too difficult for the child to solve unaided. Children were given the answer to a problem and then asked to solve another problem that could be solved quickly by using this answer, together with the principle being assessed. The children also took the WISC Arithmetic subtest. Strategies differed greatly in difficulty, with Identity being the easiest, and the Inverse and Complement principles being most difficult. The Subtrahend +1 and Subtrahend −1 problems often elicited incorrect strategies based on an overextension of the principles of addition to subtraction. It was concluded that children may have difficulty with understanding and applying the relationships between addition and subtraction. Derived fact strategy use was significantly related to both calculation level and to WISC Arithmetic scaled score. PMID:24431996

  19. On the usefulness of portal monitor unit subtraction in radiation therapy

    NASA Astrophysics Data System (ADS)

    Kuperman, Vadim Y.; Lubich, Leslie M.

    2003-08-01

    In order to avoid additional dose to patients caused by portal imaging with megavoltage x-rays, portal monitor units (MUs) are frequently subtracted from the actual treatment MUs. This study examines the usefulness of portal MU subtraction in radiation therapy. For 11 prostate cancer patients treated with 23 MV photons, dose to prostate due to portal filming with 6 MV photons was determined. In all 11 patients subtraction of portal MU values from the actual treatment MUs resulted in a small underdosing of the prostate with an average treatment error of -0.5%. Portal filming without MU subtraction would cause small overdosing of the prostate with an average treatment error of 1.2%. The results of this study indicate that the benefits of portal MU subtraction are in doubt if (a) the energy of treatment x-rays is much higher than that of the portal x-rays and/or (b) when radiotherapy is performed with physical wedges. Based on the obtained results, we argue against unconditional use of the portal MU subtraction method to eliminate the dose from portal imaging.

  20. Intravenous radionuclide cystography for the detection of vesicorenal reflux

    SciTech Connect

    Pollet, J.E.; Sharp, P.F.; Smith, F.W.; Davidson, A.I.; Miller, S.S.

    1981-01-01

    Intravenous radionuclide cystography using a single intravenous injection of 99mtechnetium diethylenetriaminepentaacetic acid, provides information on individual kidney function, coarse anatomy and vesicorenal reflux. This study investigates the effectiveness of intravenous radionuclide cystography in detecting reflux. In 58 children intravenous radionuclide cystography detected 53 ureters with reflux compared to 32 detected by voiding cystography. This difference was investigated further with patients in whom other test suggested reflux. While there was no statistically significant difference for patients having pyelonephritis or hydronephrosis, intravenous radionuclide cystography detected significantly more ureters with reflux in patients with abnormal ureteral orifices or infected urine and, therefore, predisposed to reflux. Intravenous radionuclide cystography is a more comprehensive and sensitive test for vesicorenal reflux than voiding cystography.

  1. FPGA-specific decimal sign-magnitude addition and subtraction

    NASA Astrophysics Data System (ADS)

    Vázquez, Martín; Todorovich, Elías

    2016-07-01

    The interest in sign-magnitude (SM) representation in decimal numbers lies in the IEEE 754-2008 standard, where the significand in floating-point numbers is coded as SM. However, software implementations do not meet performance constraints in some applications and more development is required in programmable logic, a key technology for hardware acceleration. Thus, in this work, two strategies for SM decimal adder/subtractors are studied and six new Field Programmable Gate Array (FPGA)-specific circuits are derived from these strategies. The first strategy is based on ten's complement (C10) adder/subtractors and the second one is based on parallel computation of an unsigned adder and an unsigned subtractor. Four of these alternative circuits are useful for at least one area-time-trade-off and specific operand size. For example, the fastest SM adder/subtractor for operand sizes of 7 and 16 decimal digits is based on the second proposed strategy with delays of 3.43 and 4.33 ns, respectively, but the fastest circuit for 34-digit operands is one of the three specific implementations based on C10 adder/subtractors with a delay of 4.65 ns.

  2. Digital hum filtering

    USGS Publications Warehouse

    Knapp, R.W.; Anderson, N.L.

    1994-01-01

    Data may be overprinted by a steady-state cyclical noise (hum). Steady-state indicates that the noise is invariant with time; its attributes, frequency, amplitude, and phase, do not change with time. Hum recorded on seismic data usually is powerline noise and associated higher harmonics; leakage from full-waveform rectified cathodic protection devices that contain the odd higher harmonics of powerline frequencies; or vibrational noise from mechanical devices. The fundamental frequency of powerline hum may be removed during data acquisition with the use of notch filters. Unfortunately, notch filters do not discriminate signal and noise, attenuating both. They also distort adjacent frequencies by phase shifting. Finally, they attenuate only the fundamental mode of the powerline noise; higher harmonics and frequencies other than that of powerlines are not removed. Digital notch filters, applied during processing, have many of the same problems as analog filters applied in the field. The method described here removes hum of a particular frequency. Hum attributes are measured by discrete Fourier analysis, and the hum is canceled from the data by subtraction. Errors are slight and the result of the presence of (random) noise in the window or asynchrony of the hum and data sampling. Error is minimized by increasing window size or by resampling to a finer interval. Errors affect the degree of hum attenuation, not the signal. The residual is steady-state hum of the same frequency. ?? 1994.

  3. Digital Opportunity

    ERIC Educational Resources Information Center

    Azzam, Amy M.

    2006-01-01

    This article details the content of a recently released report from the Children's Partnership titled "Measuring Digital Opportunity for America's Children: Where We Stand and Where We Go From Here". On the basis of 40 indicators, the report's Digital Opportunity Measuring Stick showed how U.S. children and young adults use information and…

  4. Digital TMI

    NASA Technical Reports Server (NTRS)

    Rios, Joseph

    2012-01-01

    Presenting the current status of the Digital TMI project to visiting members of the FAA Command Center. Digital TMI is an effort to store national-level traffic management initiatives in a standards-compliant manner. Work is funded by the FAA.

  5. Digital Discrimination

    ERIC Educational Resources Information Center

    Blansett, Jim

    2008-01-01

    In recent years, the Internet has become a digital commons of commerce and education. However, accessibility standards have often been overlooked online, and the digital equivalents to curb-cuts and other physical accommodations have only rarely been implemented to serve those with print disabilities. (A print disability can be a learning…

  6. Digital Roundup

    ERIC Educational Resources Information Center

    Horn, Michael B.

    2013-01-01

    State policy is crucial to the spread of digital-learning opportunities at the elementary and secondary level. A review of recent legislative action reveals policies that are constantly in flux and differ quite markedly from one state to another. Some have hoped for model digital-learning legislation that could handle all the various issues…

  7. Why Digitize?

    ERIC Educational Resources Information Center

    Smith, Abby

    This paper is a response to discussions of digitization at meetings of the National Humanities Alliance (NHA). NHA asked the Council on Library and Information Resources (CLIR) to evaluate the experiences of cultural institutions with digitization projects to date and to summarize what has been learned about the advantages and disadvantages of…

  8. Analog/Digital System for Germanium Thermometer

    NASA Technical Reports Server (NTRS)

    Woodhouse, Christopher

    1988-01-01

    Electronic system containing analog and digital circuits makes high-precision, four-wire measurements of resistance of each germanium resistance thermometer (GRT) in array of devices, using alternating current (ac) of 1 micro-A. At end measurement interval, contents of negative register subtracted from positive one, resulting in very-narrow-band synchronous demodulation of carrier wave and suppression of out-of-band noise. Microprocessor free to perform other duties after measurement complete. Useful in noisy terrestrial environments encountered in factories.

  9. Covariates of intravenous paracetamol pharmacokinetics in adults

    PubMed Central

    2014-01-01

    Background Pharmacokinetic estimates for intravenous paracetamol in individual adult cohorts are different to a certain extent, and understanding the covariates of these differences may guide dose individualization. In order to assess covariate effects of intravenous paracetamol disposition in adults, pharmacokinetic data on discrete studies were pooled. Methods This pooled analysis was based on 7 studies, resulting in 2755 time-concentration observations in 189 adults (mean age 46 SD 23 years; weight 73 SD 13 kg) given intravenous paracetamol. The effects of size, age, pregnancy and other clinical settings (intensive care, high dependency, orthopaedic or abdominal surgery) on clearance and volume of distribution were explored using non-linear mixed effects models. Results Paracetamol disposition was best described using normal fat mass (NFM) with allometric scaling as a size descriptor. A three-compartment linear disposition model revealed that the population parameter estimates (between subject variability,%) were central volume (V1) 24.6 (55.5%) L/70 kg with peripheral volumes of distribution V2 23.1 (49.6%) L/70 kg and V3 30.6 (78.9%) L/70 kg. Clearance (CL) was 16.7 (24.6%) L/h/70 kg and inter-compartment clearances were Q2 67.3 (25.7%) L/h/70 kg and Q3 2.04 (71.3%) L/h/70 kg. Clearance and V2 decreased only slightly with age. Sex differences in clearance were minor and of no significance. Clearance, relative to median values, was increased during pregnancy (FPREG = 1.14) and decreased during abdominal surgery (FABDCL = 0.715). Patients undergoing orthopaedic surgery had a reduced V2 (FORTHOV = 0.649), while those in intensive care had increased V2 (FICV = 1.51). Conclusions Size and age are important covariates for paracetamol pharmacokinetics explaining approximately 40% of clearance and V2 variability. Dose individualization in adult subpopulations would achieve little benefit in the scenarios explored. PMID:25342929

  10. Contrast agent choice for intravenous coronary angiography

    NASA Astrophysics Data System (ADS)

    Zeman, H. D.; Siddons, D. P.

    1990-05-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation X-rays and an iodine-containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic X-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron radiation source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the X-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation X-rays is visualizing a coronary artery through the left ventricle or aorta which also contain contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth. The X-ray energy spectrum of the X-17 superconduction wiggler beam line at the National Synchrotron Light Source at Brookhaven National Laboratory has been used for these calculations. Both perfect Si crystals and Si crystals with a small mosaic spread are considered as monochromators. Contrast agents containing Gd or Yb seem to have about the optimal calculated signal to noise ratio. Gd-DTPA is already approved for use as a contrast agent for

  11. Clinical Outcomes of Wulingsan Subtraction Decoction Treatment of Postoperative Brain Edema and Fever as a Complication of Glioma Neurosurgery

    PubMed Central

    Jin, Wei-rong; Zhang, Feng-e; Diao, Bao-zhong; Zhang, Yue-ying

    2016-01-01

    Objective. To evaluate the efficacy of Wulingsan subtraction (五苓散加减 WLSS) decoction in the treatment of postoperative brain edema and fever as a complication of glioma neurosurgery. Methods. This retrospective study was conducted at the Department of Neurosurgery of Liaocheng People's Hospital. Patients hospitalized between March 2011 and December 2014 were divided into three groups: Group A received WLSS oral liquid (50 mL), twice a day; Group B received an intravenous infusion of mannitol; and Group C received WLSS combined with mannitol (n = 30 patients per group). All patients were treated for 10 days continuously. Therapeutic efficacy was evaluated by measuring body temperature and indicators of renal function before and 3, 5, and 10 days after treatment. Results. Compared to the other two groups, significantly greater clinical efficacy was observed in the patients treated with mannitol (Group B; P < 0.05), although marked clinical efficacy was also observed over time in patients treated with WLSS (Group A). After 5 days, the quantifiable effects of the WLSS and mannitol combination group (Group C) were substantial (P < 0.05). The renal damage in Group B was more obvious after 5 days and 10 days. Conclusion. Compared with mannitol treatment alone, WLSS combined with mannitol induced a more rapid reduction in body temperature. Our findings suggest that patients should be started on mannitol for 3 days and then switched to WLSS to achieve obvious antipyretic effects and protect renal function. This method of treatment should be considered for clinical applications. PMID:27019661

  12. Managing leg ulceration in intravenous drug users.

    PubMed

    Geraghty, Jemell

    2015-09-01

    Chronic venous leg ulceration is a long-term condition commonly associated with lower-limb injecting and chronic venous hypertension caused by collapsed veins, incompetent valves, deep vein thrombosis and reflux. It is not usually a medical emergency, but intravenous (IV) drug users with leg ulcers can attend emergency departments (EDs) with a different primary complaint such as pain or because they cannot access local primary care or voluntary services. Leg ulceration might then be identified during history taking, so it is important that ED nurses know how to assess and manage these wounds. This article explains how to assess and manage chronic venous leg ulcers in patients with a history of IV drug use, and highlights the importance of referral to specialist services when required, and to local primary care or voluntary services, before discharge to prevent admission and re-attendance. PMID:26344539

  13. Emergency intravenous access through the femoral vein.

    PubMed

    Swanson, R S; Uhlig, P N; Gross, P L; McCabe, C J

    1984-04-01

    A study was undertaken to assess the efficacy and safety of femoral venous catheterization for resuscitation of critically ill patients in the emergency department setting. From May 1982 to April 1983, 100 attempts were made at percutaneous insertion of a large-bore catheter into the femoral veins of patients presenting to our emergency department in cardiac arrest or requiring rapid fluid resuscitation. Eighty-nine attempts were successful. Insertion was generally considered easy, and flow rates were excellent. The only noted complications were four arterial punctures and one minor groin hematoma. This study suggests that short-term percutaneous catheterization of the femoral vein provides rapid, safe, and effective intravenous access. PMID:6703430

  14. Neuromyelitis optica: potential roles for intravenous immunoglobulin.

    PubMed

    Wingerchuk, Dean M

    2013-01-01

    Neuromyelitis optica (NMO) is an idiopathic central nervous system inflammatory demyelinating disease that causes optic neuritis, transverse myelitis, and other CNS syndromes. It is distinct from multiple sclerosis and is associated with autoantibodies that target aquaporin-4 (AQP4), an astrocyte water channel. Evidence indicating antibody-mediated immune injury in NMO includes its association with other autoimmune diseases, lesional pathology that reveals prominent complement activation and immunoglobulin deposition, pathogenic potential of AQP4 autoantibodies based on in vitro studies, and reports of putative animal models of the disease. The rationale and potential role for intravenous immunoglobulin in NMO will be discussed in the context of both relapse treatment and relapse prevention. PMID:22976554

  15. Fatal kavalactone intoxication by suicidal intravenous injection.

    PubMed

    Ketola, Raimo A; Viinamäki, Jenni; Rasanen, Ilpo; Pelander, Anna; Goebeler, Sirkka

    2015-04-01

    Kavalactones are a group of compounds found in kava, a beverage or extract prepared from the rhizome of the kava plant (Piper methysticum). Traditionally kava extracts have been used for their anxiolytic and sedative properties. Sales of kava extracts were severely restricted or prohibited in European countries in 2002 following several cases of serious hepatotoxicity. Here we report a case where high concentrations of kavalactones and ethanol were detected in post mortem femoral blood. An injection needle with a 10-mL syringe containing 7.5 mL of slightly yellowish liquid was found next to the victim, and there were numerous needle prints on both lower arms following the venous tracks. No evidence of other cause of death was found in the medico-legal investigation. The case was therefore classified as suicide using an injection of kavalactones intravenously together with alcohol poisoning. PMID:25684328

  16. Ferrous iron content of intravenous iron formulations.

    PubMed

    Gupta, Ajay; Pratt, Raymond D; Crumbliss, Alvin L

    2016-06-01

    The observed biological differences in safety and efficacy of intravenous (IV) iron formulations are attributable to physicochemical differences. In addition to differences in carbohydrate shell, polarographic signatures due to ferric iron [Fe(III)] and ferrous iron [Fe(II)] differ among IV iron formulations. Intravenous iron contains Fe(II) and releases labile iron in the circulation. Fe(II) generates toxic free radicals and reactive oxygen species and binds to bacterial siderophores and other in vivo sequestering agents. To evaluate whether differences in Fe(II) content may account for some observed biological differences between IV iron formulations, samples from multiple lots of various IV iron formulations were dissolved in 12 M concentrated HCl to dissociate and release all iron and then diluted with water to achieve 0.1 M HCl concentration. Fe(II) was then directly measured using ferrozine reagent and ultraviolet spectroscopy at 562 nm. Total iron content was measured by adding an excess of ascorbic acid to reduce Fe(III) to Fe(II), and Fe(II) was then measured by ferrozine assay. The Fe(II) concentration as a proportion of total iron content [Fe(III) + Fe(II)] in different lots of IV iron formulations was as follows: iron gluconate, 1.4 and 1.8 %; ferumoxytol, 0.26 %; ferric carboxymaltose, 1.4 %; iron dextran, 0.8 %; and iron sucrose, 10.2, 15.5, and 11.0 % (average, 12.2 %). The average Fe(II) content in iron sucrose was, therefore, ≥7.5-fold higher than in the other IV iron formulations. Further studies are needed to investigate the relationship between Fe(II) content and increased risk of oxidative stress and infections with iron sucrose. PMID:26956439

  17. Safety of rapid intravenous of infusion acetaminophen

    PubMed Central

    2013-01-01

    Intravenous acetaminophen, Ofirmev®, is approved for management of mild to moderate pain, management of moderate to severe pain with adjunctive opioids, and reduction of fever. The product is supplied as a 100 mL glass vial. As stated in the prescribing information, it is recommended to be infused over 15 minutes. This recommendation is related to the formulation propacetamol, the prodrug to acetaminophen, approved in Europe, which caused pain on infusion, and data from the clinical development of acetaminophen. The objective of this retrospective chart review study was to show the lack of side effects of rapidly infusing intravenous acetaminophen. Charts of American Society of Anesthesiology (ASA) Class I–III ambulatory surgical patients who received only acetaminophen in the preoperative setting were reviewed for any infusion-related side effects. Using standard binomial proportion analyses and employing SAS/JMP software, all vital signs were analyzed for statistically significant changes between pre- and postinfusion values. One hundred charts were reviewed. Only one patient had pain on infusion, which lasted 10 seconds. No reported side effects or erythema was seen at the injection site. No infusions had to be slowed or discontinued. The median infusion time was 3:41 minutes. Of the vital signs monitored, only the systolic (P < 0.0001) and diastolic (P < 0.0099) blood pressures had statistically significant changes from pre- to postinfusion; however, they were of no clinical relevance. Acetaminophen can be administered as a rapid infusion with no significant infusion-related side effects or complications. PMID:23814378

  18. Safety of rapid intravenous of infusion acetaminophen.

    PubMed

    Needleman, Steven M

    2013-07-01

    Intravenous acetaminophen, Ofirmev®, is approved for management of mild to moderate pain, management of moderate to severe pain with adjunctive opioids, and reduction of fever. The product is supplied as a 100 mL glass vial. As stated in the prescribing information, it is recommended to be infused over 15 minutes. This recommendation is related to the formulation propacetamol, the prodrug to acetaminophen, approved in Europe, which caused pain on infusion, and data from the clinical development of acetaminophen. The objective of this retrospective chart review study was to show the lack of side effects of rapidly infusing intravenous acetaminophen. Charts of American Society of Anesthesiology (ASA) Class I-III ambulatory surgical patients who received only acetaminophen in the preoperative setting were reviewed for any infusion-related side effects. Using standard binomial proportion analyses and employing SAS/JMP software, all vital signs were analyzed for statistically significant changes between pre- and postinfusion values. One hundred charts were reviewed. Only one patient had pain on infusion, which lasted 10 seconds. No reported side effects or erythema was seen at the injection site. No infusions had to be slowed or discontinued. The median infusion time was 3:41 minutes. Of the vital signs monitored, only the systolic (P < 0.0001) and diastolic (P < 0.0099) blood pressures had statistically significant changes from pre- to postinfusion; however, they were of no clinical relevance. Acetaminophen can be administered as a rapid infusion with no significant infusion-related side effects or complications. PMID:23814378

  19. Feature Extraction of PDV Challenge Data Set A with Digital Down Shift (DDS)

    SciTech Connect

    Tunnell, T. W.

    2012-10-18

    This slide-show is about data analysis in photonic Doppler velocimetry. The digital down shift subtracts a specified velocity (frequency) from all components in the Fourier frequency domain and generates both the down shifted in-phase and out-of-phase waveforms so that phase and displacement can be extracted through a continuous unfold of the arctangent.

  20. Efficient and Flexible Strategy Use on Multi-Digit Sums: A Choice/No-Choice Study

    ERIC Educational Resources Information Center

    Torbeyns, Joke; Verschaffel, Lieven

    2013-01-01

    This study analysed children's use of mental computation strategies and standard written algorithms in the domain of multi-digit addition and subtraction, using the choice/no-choice method. Twenty-one Flemish fourth-graders (M[subscript Age] =9y10m) solved problem-items that either stimulated the use of mental computation strategies or a standard…

  1. Dynamic measurement by digital holographic interferometry based on complex phasor method

    NASA Astrophysics Data System (ADS)

    Tay, C. J.; Quan, C.; Chen, W.

    2009-03-01

    In this paper, complex phasor (CP) method is employed in digital holographic interferometry. Unlike commonly used digital phase subtraction (DPS), the proposed technique processes a CP instead of phase. It is shown that the results obtained by directly filtering the phase produce large errors. It is demonstrated that the phase is not a signal but rather a property of a signal. In addition, the results obtained by the CP method are also compared with those obtained by conventional sine/cosine transformation method.

  2. Minimum intravenous infectious dose of ovine progressive pneumonia virus (OPPV)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The minimum intravenous infectious dose for ovine progressive pneumonia virus (OPPV) WLC1 was determined using twenty-four 6 month-old lambs. Twelve groups of two 6 month-old lambs were inoculated intravenously with tissue culture fluid containing ovine progressive pneumonia virus (OPPV) WLC1 titer...

  3. Hydrothorax, hydromediastinum and pericardial effusion: a complication of intravenous alimentation.

    PubMed Central

    Damtew, B; Lewandowski, B

    1984-01-01

    Complications secondary to intravenous alimentation are rare but potentially lethal. Massive bilateral pleural effusions and a pericardial effusion developed in a patient receiving prolonged intravenous alimentation. Severe respiratory distress and renal failure ensued. He recovered with appropriate treatment. Images Fig. 1 Fig. 2 Fig. 3 PMID:6428731

  4. An investigation of self-subtraction holography in LiNbO3

    NASA Technical Reports Server (NTRS)

    Vahey, D. W.; Kenan, R. P.; Hartman, N. F.; Sherman, R. C.

    1981-01-01

    A sample having self subtraction characteristics that were very promising was tested in depth: hologram formation times were on the order of 150 sec, the null signal was less than 2.5% of the peak signal, and no fatigue nor instability was detected over the span of the experiments. Another sample, fabricated with, at most, slight modifications did not perform nearly as well. In all samples, attempts to improve self subtraction characteristics by various thermal treatments had no effects or adverse effects, with one exception in which improvement was noted after a time delay of several days. A theory developed to describe self subtraction showed the observed decrease in beam intensity with time, but the shape of the predicted decay curve was oscillatory in contrast to the exponential like decay observed. The theory was also inadequate to account for the experimental sensitivity of self subtraction to the Bragg angle of the hologram. It is concluded that self subtraction is a viable method for optical processing systems requiring background discrimination.

  5. Superiority of photon subtraction to addition for entanglement in a multimode squeezed vacuum

    NASA Astrophysics Data System (ADS)

    Das, Tamoghna; Prabhu, R.; SenDe, Aditi; Sen, Ujjwal

    2016-05-01

    We investigate the entanglement patterns of photon-added and photon-subtracted four-mode squeezed vacuum states. Entanglements in different scenarios are analyzed by varying the number of photons added or subtracted in certain modes, which are referred to as the "player" modes, the others being "spectators." We find that the photon-subtracted state can give us higher entanglement than the photon-added state which is in contrast to the two-mode situation. We also study the logarithmic negativity of the two-mode reduced density matrix obtained from the four-mode state which again shows that the state after photon subtraction can possess higher entanglement than that of the photon-added state, and we then compare it to that of the two-mode squeezed vacuum state. Moreover, we examine the non-Gaussianity of the photon-added and photon-subtracted states to find that the rich features provided by entanglement cannot be captured by the measure of nonclassicality.

  6. Automated contralateral subtraction of dental panoramic radiographs for detecting abnormalities in paranasal sinus

    NASA Astrophysics Data System (ADS)

    Hara, Takeshi; Mori, Shintaro; Kaneda, Takashi; Hayashi, Tatsuro; Katsumata, Akitoshi; Fujita, Hiroshi

    2011-03-01

    Inflammation in the paranasal sinus is often observed in seasonal allergic rhinitis or with colds, but is also an indication for odontogenic tumors, carcinoma of the maxillary sinus or a maxillary cyst. The detection of those findings in dental panoramic radiographs is not difficult for radiologists, but general dentists may miss the findings since they focus on treatments of teeth. The purpose of this work is to develop a contralateral subtraction method for detecting the odontogenic sinusitis region on dental panoramic radiographs. We developed a contralateral subtraction technique in paranasal sinus region, consisting of 1) image filtering of the smoothing and sobel operation for noise reduction and edge extraction, 2) image registration of mirrored image by using mutual information, and 3) image display method of subtracted pixel data. We employed 56 cases (24 normal and 32 abnormal). The abnormal regions and the normal cases were verified by a board-certified radiologist using CT scans. Observer studies with and without subtraction images were performed for 9 readers. The true-positive rate at a 50% confidence level in 7 out of 9 readers was improved, but there was no statistical significance in the difference of area-under-curve (AUC) in each radiologist. In conclusion, the contralateral subtraction images of dental panoramic radiographs may improve the detection rate of abnormal regions in paranasal sinus.

  7. New perspectives for diagnosis of nodular goiter by technetium-thallium subtraction scanning

    SciTech Connect

    Katagiri, M.; Harada, T.; Fukunaga, M.; Furukawa, J.; Yamane, Y.; Yasuda, K.; Yanagimoto, S.; Tomomitsu, T.; Otsuka, N.; Morita, R. )

    1989-12-01

    To improve the scintigraphic differential diagnosis of thyroid nodules, Tc-99m pertechnetate-Tl-201 Cl subtraction scintigraphy (Tc-Tl subtraction scanning) was performed in 106 patients with various histologically proven thyroid nodules. Results were evaluated by comparison with surgical findings and preoperative ultrasonographic results. Thyroid nodules were more successfully detected by Tc-Tl subtraction scanning than by either Tc-99m pertechnetate or Tl-201 Cl scintigraphy alone. Detection of nodules was further improved when images recorded by the three methods were integrally observed (sensitivity 83%, accuracy 89%), with detectability approaching that of ultrasonography. False-positive or -negative Tc-Tl subtraction scans were obtained principally when multiple nodules were present (7 cases) or when no discrepancy existed between the accumulations of Tc-99m pertechnetate and Tl-201 Cl (18 cases). Most colloid nodules exhibited irregular margins, heterogeneous internal accumulations of Tl-201 Cl, and distorted shapes on Tc-Tl subtraction scans, while the majority of adenoma were oval-shaped with smooth margins. Carcinoma were characterized by homogeneous internal accumulation of Tl-201 Cl and distorted shapes.

  8. Speech enhancement using parametric spectral subtraction combined with generalized sidelobe canceller

    NASA Astrophysics Data System (ADS)

    Cho, Jaeyoun; Krishnamurthy, Ashok

    2003-10-01

    Speech enhancement is an important problem with applications in hearing aid design, speech recognition, speech coding, etc. Parametric spectral subtraction is a common method for speech enhancement when only a single channel of data is available. On the other hand, beamforming methods can be used when multiple channels of spatially separated data are available, such as from a microphone array. In previous work, we have shown that spectral subtraction combined with spatial averaging from multiple microphones leads to improvements in speech SNR and reduction of musical noise compared with either method used alone. In this talk, we extend the previous work to combine parametric spectral subtraction with adaptive beamforming, specifically the generalized sidelobe canceller. The proposed parametric spectral subtraction method determines the parameters adaptively so as to minimize speech distortion. In addition, it is shown that the major drawback of spectral subtraction, so-called musical noise, can be diminished by adaptive beamforming process. We show that the method leads to a reduction of musical noise and results in the enhanced speech having better quality and intelligibility.

  9. Digital clubbing

    PubMed Central

    Sarkar, Malay; Mahesh, D. M.; Madabhavi, Irappa

    2012-01-01

    Digital clubbing is an ancient and important clinical signs in medicine. Although clubbed fingers are mostly asymptomatic, it often predicts the presence of some dreaded underlying diseases. Its exact pathogenesis is not known, but platelet-derived growth factor and vascular endothelial growth factor are recently incriminated in its causation. The association of digital clubbing with various disease processes and its clinical implications are discussed in this review. PMID:23243350

  10. Digital Epidemiology

    PubMed Central

    Salathé, Marcel; Bengtsson, Linus; Bodnar, Todd J.; Brewer, Devon D.; Brownstein, John S.; Buckee, Caroline; Campbell, Ellsworth M.; Cattuto, Ciro; Khandelwal, Shashank; Mabry, Patricia L.; Vespignani, Alessandro

    2012-01-01

    Mobile, social, real-time: the ongoing revolution in the way people communicate has given rise to a new kind of epidemiology. Digital data sources, when harnessed appropriately, can provide local and timely information about disease and health dynamics in populations around the world. The rapid, unprecedented increase in the availability of relevant data from various digital sources creates considerable technical and computational challenges. PMID:22844241

  11. A high sensitive two-line detector with large dynamic range for intravenous coronary angiography

    NASA Astrophysics Data System (ADS)

    Lohmann, M.; Besch, H. J.; Dix, W.-R.; Dünger, O.; Jung, M.; Menk, R. H.; Reime, B.; Schildwächter, L.

    1998-12-01

    The medical community is highly interested in methods for non-invasive imaging of coronary arteries. One method under development is dichromography. This method allows imaging of small fast moving objects like the coronary arteries including distal parts and sidebranches after intravenous injection of contrast material. Two images with monochromatic X-rays at energies just below and above the K-edge of iodine at 33.17 keV are simultaneously taken. After logarithmic subtraction coronary arteries down to 0.7 mm diameter with extremely low iodine concentrations of 10 mg/ml become visible. At the Hamburger Synchrotronstrahlungslabor HASYLAB at DESY in Hamburg, Germany the system NIKOS was developed for dichromography. In this system the detector is one of the main components. This two-line detector is an ionization chamber for the two energies. The two gaps are separated by the drift cathode. A Frisch-grid for shielding the ions in a distance of 3 mm defines the conversion room. The 336 anode strips per line with a length of 56 mm in the direction of the beam are connected to the frontend electronics. The parameters of the current version of the detector in one setting are: noise equivalent of 7.6 photons, dynamic range of 300 000 : 1, readout time for the two lines (672 pixels) 0.18 ms.

  12. Digital photography

    PubMed Central

    Windsor, J S; Rodway, G W; Middleton, P M; McCarthy, S

    2006-01-01

    Objective The emergence of a new generation of “point‐and‐shoot” digital cameras offers doctors a compact, portable and user‐friendly solution to the recording of highly detailed digital photographs and video images. This work highlights the use of such technology, and provides information for those who wish to record, store and display their own medical images. Methods Over a 3‐month period, a digital camera was carried by a doctor in a busy, adult emergency department and used to record a range of clinical images that were subsequently transferred to a computer database. Results In total, 493 digital images were recorded, of which 428 were photographs and 65 were video clips. These were successfully used for teaching purposes, publications and patient records. Conclusions This study highlights the importance of informed consent, the selection of a suitable package of digital technology and the role of basic photographic technique in developing a successful digital database in a busy clinical environment. PMID:17068281

  13. Digital radiography.

    PubMed

    Mattoon, J S

    2006-01-01

    Digital radiography has been used in human medical imaging since the 1980s with recent and rapid acceptance into the veterinary profession. Using advanced image capture and computer technology, radiographic images are viewed on a computer monitor. This is advantageous because radiographic images can be adjusted using dedicated computer software to maximize diagnostic image quality. Digital images can be accessed at computer workstations throughout the hospital, instantly retrieved from computer archives, and transmitted via the internet for consultation or case referral. Digital radiographic data can also be incorporated into a hospital information system, making record keeping an entirely paperless process. Digital image acquisition is faster when compared to conventional screen-film radiography, improving workflow and patient throughput. Digital radiography greatly reduces the need for 'retake' radiographs because of wide latitude in exposure factors. Also eliminated are costs associated with radiographic film and x-ray film development. Computed radiography, charged coupled devices, and flat panel detectors are types of digital radiography systems currently available. PMID:16971994

  14. Digital Collections, Digital Libraries & the Digitization of Cultural Heritage Information.

    ERIC Educational Resources Information Center

    Lynch, Clifford

    2002-01-01

    Discusses digital collections and digital libraries. Topics include broadband availability; digital rights protection; content, both non-profit and commercial; digitization of cultural content; sustainability; metadata harvesting protocol; infrastructure; authorship; linking multiple resources; data mining; digitization of reference works;…

  15. Non-Gaussian postselection and virtual photon subtraction in continuous-variable quantum key distribution

    NASA Astrophysics Data System (ADS)

    Li, Zhengyu; Zhang, Yichen; Wang, Xiangyu; Xu, Bingjie; Peng, Xiang; Guo, Hong

    2016-01-01

    Photon subtraction can enhance the performance of continuous-variable quantum key distribution (CV QKD). However, the enhancement effect will be reduced by the imperfections of practical devices, especially the limited efficiency of a single-photon detector. In this paper, we propose a non-Gaussian postselection method to emulate the photon substraction used in coherent-state CV QKD protocols. The virtual photon subtraction not only can avoid the complexity and imperfections of a practical photon-subtraction operation, which extends the secure transmission distance as the ideal case does, but also can be adjusted flexibly according to the channel parameters to optimize the performance. Furthermore, our preliminary tests on the information reconciliation suggest that in the low signal-to-noise ratio regime, the performance of reconciliating the postselected non-Gaussian data is better than that of the Gaussian data, which implies the feasibility of implementing this method practically.

  16. Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition

    SciTech Connect

    Lee, Su-Yong; Kim, Ho-Joon; Ji, Se-Wan; Nha, Hyunchul

    2011-07-15

    We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation ta+ra{sup {dagger}} of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the Einstein-Podolsky-Rosen-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction a and the addition a{sup {dagger}} particularly in the small-squeezing regime, whereas the optimal operation becomes the photon subtraction (case of r=0) in the large-squeezing regime.

  17. A novel background subtraction technique based on grayscale morphology for weld defect detection

    NASA Astrophysics Data System (ADS)

    Aminzadeh, Masoumeh; Kurfess, Thomas

    2016-04-01

    Optical inspection is a non-destructive quality monitoring technique to detect defects in manufactured parts. Automating the defect detection, by application of image processing, prevents the presence of human operators making the inspection more reliable, reproducible and faster. In this paper, a background subtraction technique, based on morphological operations, is proposed. The low-computational load associated with the used morphological operations makes this technique more computationally effective than background subtraction techniques such as spline approximation and surface-fitting. The performance of the technique is tested by applying to detect defects in a weld seam with non-uniform intensity distribution where the defects are precisely segmented. The proposed background subtraction technique is generalizable to sheet, surface, or part defect detection in various applications of manufacturing.

  18. Demonstration of the Equivalence of Soft and Zero-Bin Subtractions

    SciTech Connect

    Ahmad Idilbi; Thomas Mehen

    2007-11-01

    Calculations of collinear correlation functions in perturbative QCD and Soft-Collinear Effective Theory (SCET) require a prescription for subtracting soft or zero-bin contributions in order to avoid double counting the contributions from soft modes. At leading order in $\\lambda$, where $\\lambda$ is the SCET expansion parameter, the zero-bin subtractions have been argued to be equivalent to convolution with soft Wilson lines. We give a proof of the factorization of naive collinear Wilson lines that is crucial for the derivation of the equivalence. We then check the equivalence by computing the non-Abelian two-loop mixed collinear-soft contribution to the jet function in the quark form factor. These results provide strong support for the equivalence, which can be used to give a nonperturbative definition of the zero-bin subtraction at lowest order in $\\lambda$.

  19. Remark on the subtractive renormalization of the quadratically divergent scalar mass

    SciTech Connect

    Fujikawa, Kazuo

    2011-05-15

    The quadratically divergent scalar mass is subtractively renormalized unlike other divergences which are multiplicatively renormalized. We reexamine some technical aspects of the subtractive renormalization, in particular, the mass-independent renormalization of massive {lambda}{phi}{sup 4} theory with higher derivative regularization. We then discuss an unconventional scheme to introduce the notion of renormalization point {mu} to the subtractive renormalization in a theory defined by a large fixed cutoff M. The resulting renormalization group equation generally becomes inhomogeneous, but it is transformed to be homogeneous. The renormalized scalar mass consists of two components in this scheme, one with the ordinary anomalous dimension and the other which is proportional to the renormalization scale {mu}. This scheme interpolates between the theory defined by dimensional regularization and the theory with unsubtracted quadratic divergences.

  20. Modeling self-subtraction in angular differential imaging: Application to the HD 32297 debris disk

    SciTech Connect

    Esposito, Thomas M.; Fitzgerald, Michael P.; Graham, James R.; Kalas, Paul

    2014-01-01

    We present a new technique for forward-modeling self-subtraction of spatially extended emission in observations processed with angular differential imaging (ADI) algorithms. High-contrast direct imaging of circumstellar disks is limited by quasi-static speckle noise, and ADI is commonly used to suppress those speckles. However, the application of ADI can result in self-subtraction of the disk signal due to the disk's finite spatial extent. This signal attenuation varies with radial separation and biases measurements of the disk's surface brightness, thereby compromising inferences regarding the physical processes responsible for the dust distribution. To compensate for this attenuation, we forward model the disk structure and compute the form of the self-subtraction function at each separation. As a proof of concept, we apply our method to 1.6 and 2.2 μm Keck adaptive optics NIRC2 scattered-light observations of the HD 32297 debris disk reduced using a variant of the 'locally optimized combination of images' algorithm. We are able to recover disk surface brightness that was otherwise lost to self-subtraction and produce simplified models of the brightness distribution as it appears with and without self-subtraction. From the latter models, we extract radial profiles for the disk's brightness, width, midplane position, and color that are unbiased by self-subtraction. Our analysis of these measurements indicates a break in the brightness profile power law at r ≈ 110 AU and a disk width that increases with separation from the star. We also verify disk curvature that displaces the midplane by up to 30 AU toward the northwest relative to a straight fiducial midplane.

  1. Comparison of subtracted venography and phase contrast in cerebral regions by utilizing 3DT1TFE

    NASA Astrophysics Data System (ADS)

    Heo, Yeong-Cheol; Cho, Jae-Hwan; Jang, Hyon-Chol; Lee, Chang-Hee; Kim, Jung-Su; Lee, Hae-Kag

    2013-06-01

    In this study, we evaluated the 3D venography images and the phase contrast images that were subtracted by using the images that had been obtained before and after utilizing the contrast medium with a 3D, segmented, T1-weighted gradient echo sequence (3DT1TFE) when performing a cerebral magnetic resonance imaging (MRI) examination with contrast medium. The study was carried out in 10 patients who under went a brain examination with a contrast medium by using the 3.0T MR System and 8-channel sensitivity encoding (SENSE) head coil. The 3DT1TFE images after the contrast medium had been used was subtracted from the 3DT1TFE images before the utilization. The subtracted images were re-formed to venography images by using maximum intensity projection (MIP) techniques; then, the re-formed images and 3D phase contrast (PC) venography were evaluated qualitative analysis. The qualitative analysis was done to confirm the reliability of the ratings of the observers via the ICC (intraclass correlation coefficient) and then to evaluate of the statistical significance via an independent T-test. The ICC test showed that 3D PC venography images and subtracted venography images had reliabilities of 0.677 and 0.734 on average, respectively, indicating good reliability of the ratings by the observers. Because the proximal superior sagittal sinus (SSS), the middle SSS, the confluence SSS, the vein of labbe, the internal cerebral vein, and the Vein of Galen represented p > 0.05 a the independent T-test, no statistically significant difference was observed between the two images. However, a significant difference was observed between the images regarding the straight sinus (p < 0.05). As such, the venography images subtracted from the straight sinus would be better, because the average of the straight sinus was higher in subtracted venography.

  2. Modeling Self-subtraction in Angular Differential Imaging: Application to the HD 32297 Debris Disk

    NASA Astrophysics Data System (ADS)

    Esposito, Thomas M.; Fitzgerald, Michael P.; Graham, James R.; Kalas, Paul

    2014-01-01

    We present a new technique for forward-modeling self-subtraction of spatially extended emission in observations processed with angular differential imaging (ADI) algorithms. High-contrast direct imaging of circumstellar disks is limited by quasi-static speckle noise, and ADI is commonly used to suppress those speckles. However, the application of ADI can result in self-subtraction of the disk signal due to the disk's finite spatial extent. This signal attenuation varies with radial separation and biases measurements of the disk's surface brightness, thereby compromising inferences regarding the physical processes responsible for the dust distribution. To compensate for this attenuation, we forward model the disk structure and compute the form of the self-subtraction function at each separation. As a proof of concept, we apply our method to 1.6 and 2.2 μm Keck adaptive optics NIRC2 scattered-light observations of the HD 32297 debris disk reduced using a variant of the "locally optimized combination of images" algorithm. We are able to recover disk surface brightness that was otherwise lost to self-subtraction and produce simplified models of the brightness distribution as it appears with and without self-subtraction. From the latter models, we extract radial profiles for the disk's brightness, width, midplane position, and color that are unbiased by self-subtraction. Our analysis of these measurements indicates a break in the brightness profile power law at r ≈ 110 AU and a disk width that increases with separation from the star. We also verify disk curvature that displaces the midplane by up to 30 AU toward the northwest relative to a straight fiducial midplane.

  3. Resolution and contrast enhancement of subtractive second harmonic generation microscopy with a circularly polarized vortex beam

    PubMed Central

    Tian, Nian; Fu, Ling; Gu, Min

    2015-01-01

    We extend the subtractive imaging method to label-free second harmonic generation (SHG) microscopy to enhance the spatial resolution and contrast. This method is based on the intensity difference between two images obtained with circularly polarized Gaussian and doughnut-shaped beams, respectively. By characterizing the intensity and polarization distributions of the two focused beams, we verify the feasibility of the subtractive imaging method in polarization dependent SHG microscopy. The resolution and contrast enhancement in different biological samples is demonstrated. This work will open a new avenue for the applications of SHG microscopy in biomedical research. PMID:26364733

  4. Silicon-organic hybrid slot waveguide based three-input multicasted optical hexadecimal addition/subtraction

    PubMed Central

    Gui, Chengcheng; Wang, Jian

    2014-01-01

    By exploiting multiple non-degenerate four-wave mixing in a silicon-organic hybrid slot waveguide and 16-ary phase-shift keying signals, we propose and simulate three-input (A, B, C) multicasted 40-Gbaud (160-Gbit/s) optical hexadecimal addition/subtraction (A + B − C, A + C − B, B + C − A, A + B + C, A − B − C, B − A − C). The error vector magnitude (EVM) and dynamic range of signal power are analyzed to evaluate the performance of optical hexadecimal addition/subtraction. PMID:25502618

  5. Intensity Weighted Subtraction Microscopy Approach for Image Contrast and Resolution Enhancement

    PubMed Central

    Korobchevskaya, Kseniya; Peres, Chiara; Li, Zhibin; Antipov, Alexei; Sheppard, Colin J. R.; Diaspro, Alberto; Bianchini, Paolo

    2016-01-01

    We propose and demonstrate a novel subtraction microscopy algorithm, exploiting fluorescence emission difference or switching laser mode and their derivatives for image enhancement. The key novelty of the proposed approach lies in the weighted subtraction coefficient, adjusted pixel-by-pixel with respect to the intensity distributions of initial images. This method produces significant resolution enhancement and minimizes image distortions. Our theoretical and experimental studies demonstrate that this approach can be applied to any optical microscopy techniques, including label free and non-linear methods, where common super-resolution techniques cannot be used. PMID:27174367

  6. Higgs boson production in association with a jet using jettiness subtraction

    NASA Astrophysics Data System (ADS)

    Boughezal, Radja; Focke, Christfried; Giele, Walter; Liu, Xiaohui; Petriello, Frank

    2015-09-01

    We use the recently proposed jettiness-subtraction scheme to provide the complete calculation of Higgs boson production in association with a jet in hadronic collisions through next-to-next-to-leading order in perturbative QCD. This method exploits the observation that the N-jettiness event-shape variable completely describes the singularity structure of QCD when final-state colored particles are present. Our results are in agreement with a recent computation of the gg and qg partonic initial states based on sector-improved residue subtraction. We present phenomenological results for both fiducial cross sections and distributions at the LHC.

  7. Intensity Weighted Subtraction Microscopy Approach for Image Contrast and Resolution Enhancement

    NASA Astrophysics Data System (ADS)

    Korobchevskaya, Kseniya; Peres, Chiara; Li, Zhibin; Antipov, Alexei; Sheppard, Colin J. R.; Diaspro, Alberto; Bianchini, Paolo

    2016-05-01

    We propose and demonstrate a novel subtraction microscopy algorithm, exploiting fluorescence emission difference or switching laser mode and their derivatives for image enhancement. The key novelty of the proposed approach lies in the weighted subtraction coefficient, adjusted pixel-by-pixel with respect to the intensity distributions of initial images. This method produces significant resolution enhancement and minimizes image distortions. Our theoretical and experimental studies demonstrate that this approach can be applied to any optical microscopy techniques, including label free and non-linear methods, where common super-resolution techniques cannot be used.

  8. Addition and subtraction operation of optical orbital angular momentum with dielectric metasurfaces

    NASA Astrophysics Data System (ADS)

    Yi, Xunong; Li, Ying; Ling, Xiaohui; Liu, Yachao; Ke, Yougang; Fan, Dianyuan

    2015-12-01

    In this work, we propose a simple approach to realize addition and subtraction operation of optical orbital angular momentum (OAM) based on dielectric metasurfaces. The spin-orbit interaction of light in spatially inhomogeneous and anisotropic metasurfaces results in the spin-to-orbital angular momentum conversion. The subtraction system of OAM consists of two cascaded metasurfaces, while the addition system of OAM is constituted by inserting a half waveplate (HWP) between the two metasurfaces. Our experimental results are in good agreement with the theoretical calculation. These results could be useful for OAM-carrying beams applied in optical communication, information processing, etc.

  9. Intensity Weighted Subtraction Microscopy Approach for Image Contrast and Resolution Enhancement.

    PubMed

    Korobchevskaya, Kseniya; Peres, Chiara; Li, Zhibin; Antipov, Alexei; Sheppard, Colin J R; Diaspro, Alberto; Bianchini, Paolo

    2016-01-01

    We propose and demonstrate a novel subtraction microscopy algorithm, exploiting fluorescence emission difference or switching laser mode and their derivatives for image enhancement. The key novelty of the proposed approach lies in the weighted subtraction coefficient, adjusted pixel-by-pixel with respect to the intensity distributions of initial images. This method produces significant resolution enhancement and minimizes image distortions. Our theoretical and experimental studies demonstrate that this approach can be applied to any optical microscopy techniques, including label free and non-linear methods, where common super-resolution techniques cannot be used. PMID:27174367

  10. Pharmacokinetic interaction of intravenous fentanyl with ketoconazole.

    PubMed

    Ziesenitz, Victoria C; König, Sonja K; Mahlke, Nina S; Skopp, Gisela; Haefeli, Walter E; Mikus, Gerd

    2015-06-01

    Fentanyl is primarily metabolized by CYP3A, but has also been suggested to act as a weak inhibitor of CYP3A. We investigated the influence of CYP3A inhibition by ketoconazole on the pharmacokinetics of intravenously administered fentanyl and the effect of fentanyl on CYP3A activity. A prospective, open-label, randomized, monocentre, crossover study was conducted in 16 healthy volunteers. They received fentanyl alone (5 microgram per kilogram) or fentanyl plus ketoconazole (200 milligram orally B.I.D. over 2 days). Naloxone (2 × 0.2 milligram i.v.) was given simultaneously with fentanyl to mitigate any opioid effect. Midazolam was administered as a CYP3A probe drug. Fentanyl and its metabolites were quantified by LC/MS/MS in blood and urine samples obtained over 24 hour. Exposure of fentanyl (AUC0- ∞ ) was significantly increased to 133% and systemic clearance was reduced to 78% by ketoconazole, norfentanyl formation was significantly delayed and partial metabolic clearance decreased to 18%. Fentanyl had no influence on midazolam exposure and CYP3A activity whereas ketoconazole decreased CYP3A activity to 13%. Although fentanyl N-dealkylation is substantially inhibited by ketoconazole, exposure of fentanyl itself increased by one third only. Clinically fentanyl dosage adjustments may become necessary when ketoconazole or other strong CYP3A inhibitors are given simultaneously. Fentanyl itself does not influence CYP3A activity. PMID:25651378

  11. Multiple Intravenous Infusions Phase 1b

    PubMed Central

    Cassano-Piché, A; Fan, M; Sabovitch, S; Masino, C; Easty, AC

    2012-01-01

    Background Minimal research has been conducted into the potential patient safety issues related to administering multiple intravenous (IV) infusions to a single patient. Previous research has highlighted that there are a number of related safety risks. In Phase 1a of this study, an analysis of 2 national incident-reporting databases (Institute for Safe Medical Practices Canada and United States Food and Drug Administration MAUDE) found that a high percentage of incidents associated with the administration of multiple IV infusions resulted in patient harm. Objectives The primary objectives of Phase 1b of this study were to identify safety issues with the potential to cause patient harm stemming from the administration of multiple IV infusions; and to identify how nurses are being educated on key principles required to safely administer multiple IV infusions. Data Sources and Review Methods A field study was conducted at 12 hospital clinical units (sites) across Ontario, and telephone interviews were conducted with program coordinators or instructors from both the Ontario baccalaureate nursing degree programs and the Ontario postgraduate Critical Care Nursing Certificate programs. Data were analyzed using Rasmussen’s 1997 Risk Management Framework and a Health Care Failure Modes and Effects Analysis. Results Twenty-two primary patient safety issues were identified with the potential to directly cause patient harm. Seventeen of these (critical issues) were categorized into 6 themes. A cause-consequence tree was established to outline all possible contributing factors for each critical issue. Clinical recommendations were identified for immediate distribution to, and implementation by, Ontario hospitals. Future investigation efforts were planned for Phase 2 of the study. Limitations This exploratory field study identifies the potential for errors, but does not describe the direct observation of such errors, except in a few cases where errors were observed. Not all

  12. Intravenous buprenorphine and norbuprenorphine pharmacokinetics in humans

    PubMed Central

    Huestis, M.A.; Cone, E.J.; Pirnay, S.O.; Umbricht, A.; Preston, K.L.

    2013-01-01

    Background Prescribed sublingual (SL) buprenorphine is sometimes diverted for intravenous (IV) abuse, but no human pharmacokinetic data are available following high-dose IV buprenorphine. Methods Plasma was collected for 72 h after administration of placebo or 2, 4, 8, 12, or 16 mg IV buprenorphine in escalating order (single-blind, double-dummy) in 5 healthy male non-dependent opioid users. Buprenorphine and its primary active metabolite, norbuprenorphine, were quantified by liquid chromatography tandem mass spectrometry with limits of quantitation of 0.1 μg/L. Results Maximum buprenorphine concentrations (mean ± SE) were detected 10 min after 2, 4, 8, 12, 16 mg IV: 19.3±1.0, 44.5±4.8, 85.2±7.7, 124.6±16.6, and 137.7±18.8 μg/L, respectively. Maximum norbuprenorphine concentrations occurred 10–15 min (3.7±0.7 μg/L) after 16 mg IV administration. Conclusions Buprenorphine concentrations increased in a significantly linear dose-dependent manner up to 12 mg IV buprenorphine. Thus, previously demonstrated pharmacodynamic ceiling effects (over 2–16 mg) are not due to pharmacokinetic adaptations within this range, although they may play a role at doses higher than 12 mg. PMID:23246635

  13. Influence of Intravenous Immunoglobulin Treatment on Thrombopoiesis.

    PubMed

    Meyer, Oliver; Winter, Oliver; Salama, Abdulgabar

    2012-06-01

    AIM: The mechanisms by which intravenous immunoglobulins (IVIg) result in an increase in platelet counts in most patients with autoimmune thrombocytopenia (ITP) have not yet been fully explained. One of these mechanisms may be related to stimulation of thrombopoiesis. METHODS: A total of 13 adult patients who received IVIg were studied: 11 patients with primary ITP, 1 patient with ITP related to common variable immunodeficiency (CVID), and 1 patient with uncharacterized thrombocytopenia. IVIg (0.5-1.5 g/kg body weight) was administered on consecutive days (days 1-3). Endogenous thrombopoietin (eTPO) was measured prior to and at least 1 day following treatment. In addition, IL-6 was measured in 5 of the treated patients. RESULTS: In 10 of 13 patients, IVIg treatment resulted in an increase in platelet counts. eTPO remained unchanged or elevated in almost all cases where the platelet count remained low (<100 × 10(3)/μ0. In all cases with normal or increased platelet counts (>100 × 10(3)/μ0, the eTPO concentration decreased. Furthermore, IVIg induced IL-6 synthesis in all 5 examined patients. CONCLUSION: Our data indicate that the induction of eTPO synthesis by IL-6 may be a potential mechanism in which IVIg may stimulate thrombopoiesis. Further studies are required to characterize this mechanism. PMID:22851938

  14. Repeated intravenous doxapram induces phrenic motor facilitation

    PubMed Central

    Sandhu, MS; Lee, KZ; Gonzalez-Rothi, EJ; Fuller, DD

    2013-01-01

    Doxapram is a respiratory stimulant used to treat hypoventilation. Here we investigated whether doxapram could also trigger respiratory neuroplasticity. Specifically, we hypothesized that intermittent delivery of doxapram at low doses would lead to long-lasting increases (i.e., facilitation) of phrenic motor output in anesthetized, vagotomized, and mechanically-ventilated rats. Doxapram was delivered intravenously in a single bolus (2 or 6 mg/kg) or as a series of 3 injections (2 mg/kg) at 5 min intervals. Control groups received pH-matched saline injections (vehicle) or no treatment (anesthesia time control). Doxapram evoked an immediate increase in phrenic output in all groups, but a persistent increase in burst amplitude only occurred after repeated dosing with 2 mg/kg. At 60 min following the last injection, phrenic burst amplitude was 168±24% of baseline (%BL) in the group receiving 3 injections (P < 0.05 vs. controls), but was 103±8%BL and 112±4%BL in the groups receiving a single dose of 2 or 6 mg/kg, respectively. Following bilateral section of the carotid sinus nerves, the acute phrenic response to doxapram (2 mg/kg) was reduced by 68% suggesting that at low doses the drug was acting primarily via the carotid chemoreceptors. We conclude that intermittent application of doxapram can trigger phrenic neuroplasticity, and this approach might be of use in the context of respiratory rehabilitation following neurologic injury. PMID:24013015

  15. Clinical applications of intravenous immunoglobulins in neurology.

    PubMed

    Hughes, R A C; Dalakas, M C; Cornblath, D R; Latov, N; Weksler, M E; Relkin, N

    2009-12-01

    Intravenous immunoglobulin (IVIg) is used increasingly in the management of patients with neurological conditions. The efficacy and safety of IVIg treatment in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and Guillain-Barré syndrome (GBS) have been established clearly in randomized controlled trials and summarized in Cochrane systematic reviews. However, questions remain regarding the dose, timing and duration of IVIg treatment in both disorders. Reports about successful IVIg treatment in other neurological conditions exist, but its use remains investigational. IVIg has been shown to be efficacious as second-line therapy in patients with dermatomyositis and suggested to be of benefit in some patients with polymyositis. In patients with inclusion body myositis, IVIg was not shown to be effective. IVIg is also a treatment option in exacerbations of myasthenia gravis. Studies with IVIg in patients with Alzheimer's disease have reported increased plasma anti-Abeta antibody titres associated with decreased Abeta peptide levels in the cerebrospinal fluid following IVIg treatment. These changes at the molecular level were accompanied by improved cognitive function, and large-scale randomized trials are under way. PMID:19883422

  16. [Treatment of renal colic with intravenous ketoprofen].

    PubMed

    Pourrat, J P; Dueymes, J M; Conte, J J

    1984-10-01

    In view of the part played by renal prostaglandins in the mechanisms responsible for pain in renal colic, it was worth trying to find out whether nonsteroidal anti-inflammatory agents, which inhibit prostaglandin synthesis, have an analgesic effect of their own. In a double-blind trial the effects of ketoprofen 100 mg administered intravenously alone or associated with noramidopyrine were investigated in 62 patients divided at random into two equal groups. A rapid analgesic effect was observed with no significant difference between the groups. No severe side-effects were recorded. The double-blind method made it possible to confirm that ketoprofen administered alone relieved pain in 97% of the patients (with complete sedation in 45%) and acted within 5 minutes. Owing to their effectiveness and safety nonsteroidal anti-inflammatory drugs (especially ketoprofen) may be proposed as an alternative to conventional treatments of renal colic. But because of their activity they should not be prescribed until a firm diagnosis has been made. The cause of the colic should also be rapidly determined in order to treat it as well as the pain it produces. PMID:6238315

  17. Intravenous pamidronate: infusion rate and safety.

    PubMed

    Tyrrell, C J; Collinson, M; Madsen, E L; Ford, J M; Coleman, T

    1994-01-01

    In view of previous animal studies showing that pamidronate (Aredia) can cause renal damage, and human data indicating that pamidronate in doses of 60-90 mg is more effective in the control of tumor-induced hypercalcemia than when given at lower doses, we decided to investigate whether pamidronate 90 mg infused over 60 minutes at weekly intervals had any adverse effects on renal function in patients with bone metastases. Twelve patients, 7 female (all with breast cancer) and 5 male (4 with prostate cancer, 1 with bladder cancer) were entered into the trial. Each patient received weekly intravenous infusions of pamidronate 90 mg in 250 ml normal saline over 60 minutes for 4 weeks. 51Cr-EDTA clearances showed no significant changes in renal function. Urinary N-acetyl-B-D-glucosaminidase/creatinine ratios fluctuated considerably, but no consistent changes were found. No patient with a normal level of urinary beta 2-microglobulin had elevated levels at the end of the trial. Serum creatinine levels did not change significantly, though 1 patient had a corrected serum calcium level of < 2 mmol/L on a single occasion on day 8. No evidence of renal toxicity was detected. However, the possibility that neprohtoxicity would ultimately appear cannot be excluded, and these favourable short-term results cannot be extrapolated to patients with impaired renal function. PMID:7873459

  18. Plasma atropine concentrations via intravenous, endotracheal, and intraosseous administration.

    PubMed

    Prete, M R; Hannan, C J; Burkle, F M

    1987-03-01

    To date, there have been limited studies on the pharmacokinetics of intravenous atropine and no pharmacokinetic studies on the endotracheal or intraosseous administration of atropine. This study examines the time to peak plasma concentration of atropine following intravenous, endotracheal, and intraosseous administration in anesthetized monkeys using a triple crossover design. Plasma atropine was assayed by a radioreceptor method. The time to peak plasma concentration of atropine was shortest with intravenous administration; and longest with endotracheal administration. The mean plasma concentration of atropine was significantly higher in intravenous administrations than in endotracheal administrations at 0.75 and 2 minutes; compared to that noted in intraosseous administrations, the concentration was significantly higher only at 0.75 minutes. The mean plasma concentration of atropine administered intraosseously was significantly higher than that of endotracheal administrations at 5 minutes and was greater than that of intravenous and endotracheal administrations for the samples collected from 5 to 30 minutes. The endotracheal and intraosseous routes provide alternatives to the intravenous administration of atropine when intravenous access is limited or not available. PMID:3828010

  19. Perceiving fingers in single-digit arithmetic problems.

    PubMed

    Berteletti, Ilaria; Booth, James R

    2015-01-01

    In this study, we investigate in children the neural underpinnings of finger representation and finger movement involved in single-digit arithmetic problems. Evidence suggests that finger representation and finger-based strategies play an important role in learning and understanding arithmetic. Because different operations rely on different networks, we compared activation for subtraction and multiplication problems in independently localized finger somatosensory and motor areas and tested whether activation was related to skill. Brain activations from children between 8 and 13 years of age revealed that only subtraction problems significantly activated finger motor areas, suggesting reliance on finger-based strategies. In addition, larger subtraction problems yielded greater somatosensory activation than smaller problems, suggesting a greater reliance on finger representation for larger numerical values. Interestingly, better performance in subtraction problems was associated with lower activation in the finger somatosensory area. Our results support the importance of fine-grained finger representation in arithmetical skill and are the first neurological evidence for a functional role of the somatosensory finger area in proficient arithmetical problem solving, in particular for those problems requiring quantity manipulation. From an educational perspective, these results encourage investigating whether different finger-based strategies facilitate arithmetical understanding and encourage educational practices aiming at integrating finger representation and finger-based strategies as a tool for instilling stronger numerical sense. PMID:25852582

  20. Comparison of analgesic efficacy of intravenous Paracetamol and intravenous dexketoprofen trometamol in multimodal analgesia after hysterectomy

    PubMed Central

    Ünal, Çiğdem; Çakan, Türkay; Baltaci, Bülent; Başar, Hülya

    2013-01-01

    Backround: We aimed to evaluate analgesic efficacy, opioid-sparing, and opioid-related adverse effects of intravenous paracetamol and intravenous dexketoprofen trometamol in combination with iv morphine after total abdominal hysterectomy. Materials and Methods: Sixty American Society of Anesthesiologist Physical Status Classification I-II patients scheduled for total abdominal hysterectomy were enrolled to this double-blinded, randomized, placebo controlled, and prospective study. Patients were divided into three groups as paracetamol, dexketoprofen trometamol, and placebo (0.9% NaCl) due to their post-operative analgesic usage. Intravenous patient controlled analgesia morphine was used as a rescue analgesic in all groups. Pain scores, hemodynamic parameters, morphine consumption, patient satisfaction, and side-effects were evaluated. Results: Visual Analog Scale (VAS) scores were not statistically significantly different among the groups in all evaluation times, but decrease in VAS scores was statistically significant after the evaluation at 12th h in all groups. Total morphine consumption (morphine concentration = 0.2 mg/ml) in group paracetamol (72.3 ± 38.0 ml) and dexketoprofen trometamol (69.3 ± 24.1 ml) was significantly lower than group placebo (129.3 ± 22.6 ml) (P < 0.001). Global satisfaction scores of the patients in group placebo was significantly lower than group dexketoprofen trometamol after surgery and the increase in global satisfaction score was significant only in group placebo. Conclusion: Dexketoprofen trometamol and Paracetamol didn’t cause significant change on pain scores, but increased patients’ comfort. Although total morphine consumption was significantly decreased by both drugs, the incidence of nausea and vomiting were similar among the groups. According to results of the present study routine addition of dexketoprofen trometamol and paracetamol to patient controlled analgesia morphine after hysterectomies is not recommended. PMID

  1. Digital caliper

    USGS Publications Warehouse

    Cable, Louella E.

    1967-01-01

    The large number of measurements needed to describe fully the characteristics of biological specimens and other objects has always been tedious and time consuming. The work can be done much more rapidly and with greater accuracy with a digital caliper recently developed by us. The digital caliper is a new electronic instrument built to measure objects precisely throughout the range of 0.1 mm to 1.0 m. Calipers of several different discrete sizes make it possible to select the most convenient unit for the particular range of length and degree of accuracy desired.

  2. Digital Radiography

    NASA Technical Reports Server (NTRS)

    1986-01-01

    System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

  3. Intravenous versus oral rehydration in athletes.

    PubMed

    van Rosendal, Simon Piet; Osborne, Mark Andrew; Fassett, Robert Gordon; Lancashire, Bill; Coombes, Jeff Scott

    2010-04-01

    Fluid is typically administered via intravenous (IV) infusion to athletes who develop clinical symptoms of heat illness, based on the perception that dehydration is a primary factor contributing to the condition. However, other athletes also voluntarily rehydrate with IV fluid as opposed to, or in conjunction with, oral rehydration. The voluntary use of IV fluids to accelerate rehydration in dehydrated, though otherwise healthy athletes, has recently been banned by the World Anti-Doping Agency. However, the technique remains appealing to many athletes. Given that it now violates the Anti-Doping Code, it is important to determine whether potential benefits of using this technique outweigh the risks involved. Several studies have shown that rehydration is more rapid with IV fluid. However, the benefits are generally transient and only small differences to markers of hydration status are seen when comparing IV and oral rehydration. Furthermore, several studies have shown improvements in cardiovascular function and thermoregulation with IV fluid, while others have indicated that oral fluid is superior. Subsequent exercise performance has not been improved to a greater extent with one technique over the other. The paucity of definitive findings is probably related to the small number of studies investigating these variables and the vast differences in the designs of studies that have been conducted. The major limitation of IV rehydration is that it bypasses oropharyngeal stimulation, which has an influence on factors such as thirst sensation, antidiuretic hormone (arginine vasopressin) release, cutaneous vasodilation and mean arterial pressure. Further research is necessary to determine the relative benefits of oral and IV rehydration for athletes. PMID:20364876

  4. Application of subtractive suppression hybridization in studying differentially expressed genes between pathotypes of Ascochyta rabiei.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ascochyta rabiei causes ascochyta blight of chickpea. Two pathotypes have been identified. The two pathotypes are inter-mating, and no neutral molecular markers were found specific for either pathotype. Here we report using subtractive suppressive hybridization in an attempt to identify pathotype-...

  5. An Analysis of Word Problems in School Mathematics Texts: Operation of Addition and Subtraction

    ERIC Educational Resources Information Center

    Singh, Parmjit

    2006-01-01

    This paper discusses the types of word problems represented in Malaysia's primary one, primary two and primary three mathematics texts based on Van De Walle's model (1998) in the operations of addition and subtraction. A test was constructed to measure students' success based on this model. The data from this study indicates that the Malaysian…

  6. Computer-Aided Diagnostic (CAD) Scheme by Use of Contralateral Subtraction Technique

    NASA Astrophysics Data System (ADS)

    Nagashima, Hiroyuki; Harakawa, Tetsumi

    We developed a computer-aided diagnostic (CAD) scheme for detection of subtle image findings of acute cerebral infarction in brain computed tomography (CT) by using a contralateral subtraction technique. In our computerized scheme, the lateral inclination of image was first corrected automatically by rotating and shifting. The contralateral subtraction image was then derived by subtraction of reversed image from original image. Initial candidates for acute cerebral infarctions were identified using the multiple-thresholding and image filtering techniques. As the 1st step for removing false positive candidates, fourteen image features were extracted in each of the initial candidates. Halfway candidates were detected by applying the rule-based test with these image features. At the 2nd step, five image features were extracted using the overlapping scale with halfway candidates in interest slice and upper/lower slice image. Finally, acute cerebral infarction candidates were detected by applying the rule-based test with five image features. The sensitivity in the detection for 74 training cases was 97.4% with 3.7 false positives per image. The performance of CAD scheme for 44 testing cases had an approximate result to training cases. Our CAD scheme using the contralateral subtraction technique can reveal suspected image findings of acute cerebral infarctions in CT images.

  7. Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

    ERIC Educational Resources Information Center

    Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

    2011-01-01

    Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

  8. Limb Looking: The effects of background subtraction on the temperature of SXT loops.

    NASA Astrophysics Data System (ADS)

    Medlin, D. A.; Blevins, H. T.; Schmelz, J. T.

    2003-05-01

    Knowing the temperature distribution along a loop is one possible test for the coronal heating models. The matter of how background subtraction may or may not affect the temperature distribution of loops could also play a crucial role in this analysis. Several instruments are currently available for loop studies, and numerous techniques are used to determine the temperature distributions along the loops. This has lead to many different, and mostly conflicting temperature results. We have chosen the Soft X-ray Telescope (SXT), aboard the Japanese satellite Yohkoh, for this study. The SXT data archives were searched for possible loop candidates. A set of loops on the limb, as well as a set of loops on the disk, were chosen for analysis. Temperature maps were generated for each loop with and without background subtraction. For each loop, we used both a uniform background subtraction as well as a pixel-by-pixel background subtraction. Once the temperature as a function of arc length has been found, it is then compared to the predictions made by different models. The Solar physics research at the University of Memphis is supported by NASA grants NAG5-9783 and NAG5-12096.

  9. Detecting small anatomical change with 3D serial MR subtraction images

    NASA Astrophysics Data System (ADS)

    Holden, Mark; Denton, Erica R. E.; Jarosz, J. M.; Cox, T. C.; Studholme, Colin; Hawkes, David J.; Hill, Derek L.

    1999-05-01

    Spoiled gradient echo volume MR scans were obtained from 5 growth hormone (GH) patients and 6 normal controls. The patients were scanned before treatment and after 3 and 6 months of GH therapy. The controls were scanned at similar intervals. A calibration phantom was scanned on the same day as each subject. The phantom images were registered with a 9 degree of freedom algorithm to measure scaling errors due to changes in scanner calibration. The second and third images were each registered with a 6 degree of freedom algorithm to the first (baseline) image by maximizing normalized mutual information, and transformed, with and without scaling error correction, using sinc interpolation. Each registered and transformed image had the baseline image subtracted to generate a difference image. Two neuro-radiologists were trained to detect structural change with difference images containing synthetic misregistration and scale changes. They carried out a blinded assessment of anatomical change for the unregistered; aligned and subtracted; and scale corrected, aligned and subtracted images. The results show a significant improvement in the detection of structural change and inter-observer agreement when aligned and subtracted images were used instead of unregistered ones. The structural change corresponded to an increase in brain: CSF ratio.

  10. Dipole splitting algorithm: A practical algorithm to use the dipole subtraction procedure

    NASA Astrophysics Data System (ADS)

    Hasegawa, K.

    2015-11-01

    The Catani-Seymour dipole subtraction is a general and powerful procedure to calculate the QCD next-to-leading order corrections for collider observables. We clearly define a practical algorithm to use the dipole subtraction. The algorithm is called the dipole splitting algorithm (DSA). The DSA is applied to an arbitrary process by following well defined steps. The subtraction terms created by the DSA can be summarized in a compact form by tables. We present a template for the summary tables. One advantage of the DSA is to allow a straightforward algorithm to prove the consistency relation of all the subtraction terms. The proof algorithm is presented in the following paper [K. Hasegawa, arXiv:1409.4174]. We demonstrate the DSA in two collider processes, pp to μ -μ + and 2 jets. Further, as a confirmation of the DSA, it is shown that the analytical results obtained by the DSA in the Drell-Yan process exactly agree with the well known results obtained by the traditional method.

  11. Assessment of Subtraction Scene Understanding Using a Story-Generation Task

    ERIC Educational Resources Information Center

    Kinda, Shigehiro

    2010-01-01

    The present study used a new assessment technique, the story-generation task, to examine students' understanding of subtraction scenes. The students from four grade levels (110 first-, 107 third-, 110 fourth- and 119 sixth-graders) generated stories under the constraints provided by a picture (representing Change, Combine or Compare scene) and a…

  12. Generating Scenarios of Addition and Subtraction: A Study of Japanese University Students

    ERIC Educational Resources Information Center

    Kinda, Shigehiro

    2013-01-01

    Students are presented with problems involving three scenario types of addition and subtraction in elementary mathematics: one dynamic ("Change") and two static ("Combine, Compare"). Previous studies have indicated that the dynamic type is easier for school children, whereas the static types are more difficult and comprehended only gradually…

  13. Standardization and adult norms for the sequential subtracting tasks of serial 3's and 7's.

    PubMed

    Bristow, Thomas; Jih, Chwan-Shyang; Slabich, Artrina; Gunn, Jamie

    2016-01-01

    The Serial 3's and 7's subtraction tasks are traditionally used in mental status examinations. The usefulness of these tasks is based upon the assumption that they measure attention and mental concentration. However, there is no uniform method of administration, and there are no recognized norms for these subtraction tasks, which has led some in the field of psychiatry and neuropsychology to conclude that the tests are not useful. The purpose of this research had three goals: (a) to create a standardization of the administration, (b) to provide a structured and consistent framework for the data evaluation, and (c) to create adult norms as a frame of reference for interpretation. The study investigated normal control subjects (N = 204) and specific variables of interest included both efficiency and accuracy of performance. The results demonstrated that when used conjointly, Serial 3's and Serial 7's are an efficient and accurate measure of sequential subtracting, but even more importantly, the study revealed the hierarchical increase in cognitive demand when the performances between 3's and 7's were compared. With standardization and norms, serial subtraction becomes a more effective screening technique within the context of a mental status examination. Similarly, the conjoint administration of these tasks yields synergistic data that can be useful in determining deficits in the cognitive domains of attention and working memory. PMID:27218700

  14. Preschoolers' Nonsymbolic Arithmetic with Large Sets: Is Addition More Accurate than Subtraction?

    ERIC Educational Resources Information Center

    Shinskey, Jeanne L.; Chan, Cindy Ho-man; Coleman, Rhea; Moxom, Lauren; Yamamoto, Eri

    2009-01-01

    Adult and developing humans share with other animals analog magnitude representations of number that support nonsymbolic arithmetic with large sets. This experiment tested the hypothesis that such representations may be more accurate for addition than for subtraction in children as young as 3 1/2 years of age. In these tasks, the experimenter hid…

  15. Operational Momentum in Large-Number Addition and Subtraction by 9-Month-Olds

    ERIC Educational Resources Information Center

    McCrink, Koleen; Wynn, Karen

    2009-01-01

    Recent studies on nonsymbolic arithmetic have illustrated that under conditions that prevent exact calculation, adults display a systematic tendency to overestimate the answers to addition problems and underestimate the answers to subtraction problems. It has been suggested that this "operational momentum" results from exposure to a…

  16. Correlated noise in networks of gravitational-wave detectors: Subtraction and mitigation

    NASA Astrophysics Data System (ADS)

    Thrane, E.; Christensen, N.; Schofield, R. M. S.; Effler, A.

    2014-07-01

    One of the key science goals of advanced gravitational-wave detectors is to observe a stochastic gravitational-wave background. However, recent work demonstrates that correlated magnetic fields from Schumann resonances can produce correlated strain noise over global distances, potentially limiting the sensitivity of stochastic background searches with advanced detectors. In this paper, we estimate the correlated noise budget for the worldwide advanced detector network and conclude that correlated noise may affect upcoming measurements. We investigate the possibility of a Wiener filtering scheme to subtract correlated noise from Advanced LIGO searches, and estimate the required specifications. We also consider the possibility that residual correlated noise remains following subtraction, and we devise an optimal strategy for measuring astronomical parameters in the presence of correlated noise. Using this new formalism, we estimate the loss of sensitivity for a broadband, isotropic stochastic background search using 1 yr of LIGO data at design sensitivity. Given our current noise budget, the uncertainty with which LIGO can estimate energy density will likely increase by a factor of ≈12—if it is impossible to achieve significant subtraction. Additionally, narrow band cross-correlation searches may be severely affected at low frequencies f ≲70 Hz without effective subtraction.

  17. Addition Table of Colours: Additive and Subtractive Mixtures Described Using a Single Reasoning Model

    ERIC Educational Resources Information Center

    Mota, A. R.; Lopes dos Santos, J. M. B.

    2014-01-01

    Students' misconceptions concerning colour phenomena and the apparent complexity of the underlying concepts--due to the different domains of knowledge involved--make its teaching very difficult. We have developed and tested a teaching device, the addition table of colours (ATC), that encompasses additive and subtractive mixtures in a single…

  18. Fostering Taiwanese Preschoolers' Understanding of the Addition-Subtraction Inverse Principle

    ERIC Educational Resources Information Center

    Lai, Meng-Lung; Baroody, Arthur J.; Johnson, Amanda R.

    2008-01-01

    The present research involved gauging preschoolers' learning potential for a key arithmetic concept, the addition-subtraction inverse principle (e.g., 2+1-1=2). Sixty 4- and 5-year-old Taiwanese children from two public preschools serving low- and middle-income families participated in the training experiment. Half were randomly assigned to an…

  19. Isolation of Diapause-Regulated Genes from the Flesh Fly, Sarcophaga crassipalpis by Suppressive Subtractive Hybridization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subtractive suppressive hybridization (SSH) was used to characterize the diapause transcriptome of the flesh fly Sarcophaga crassipalpis. Through these efforts, we isolated 97 unique clones which were used as probes in northern hybridization to assess their expression during diapause. Of these, 17...

  20. Spectral Dark Subtraction: A MODTRAN-Based Algorithm for Estimating Ground Reflectance without Atmospheric Information

    NASA Technical Reports Server (NTRS)

    Freedman, Ellis; Ryan, Robert; Pagnutti, Mary; Holekamp, Kara; Gasser, Gerald; Carver, David; Greer, Randy

    2007-01-01

    Spectral Dark Subtraction (SDS) provides good ground reflectance estimates across a variety of atmospheric conditions with no knowledge of those conditions. The algorithm may be sensitive to errors from stray light, calibration, and excessive haze/water vapor. SDS seems to provide better estimates than traditional algorithms using on-site atmospheric measurements much of the time.

  1. Brief Report: Additive and Subtractive Counterfactual Reasoning of Children with High-Functioning Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Begeer, Sander; Terwogt, Mark Meerum; Lunenburg, Patty; Stegge, Hedy

    2009-01-01

    The development of additive ("If only I had done...") and subtractive ("If only I had not done....") counterfactual reasoning was examined in children with High Functioning Autism Spectrum Disorders (HFASD) (n = 72) and typically developing controls (n = 71), aged 6-12 years. Children were presented four stories where they could generate…

  2. Developing Prospective Teachers' Understanding of Addition and Subtraction with Whole Numbers

    ERIC Educational Resources Information Center

    Roy, George J.

    2014-01-01

    This study was situated in a semester-long classroom teaching experiment examining prospective teachers' understanding of number concepts and operations. The purpose of this paper is to describe the learning goals, tasks, and tools used to cultivate prospective teachers' understanding of addition and subtraction with whole numbers.…

  3. Wavelength self-calibration and sky subtraction for Fabry-Pérot interferometers: applications to OSIRIS

    NASA Astrophysics Data System (ADS)

    Weinzirl, T.; Aragón-Salamanca, A.; Bamford, S. P.; Rodríguez del Pino, B.; Gray, M. E.; Chies-Santos, A. L.

    2015-12-01

    We describe techniques concerning wavelength calibration and sky subtraction to maximize the scientific utility of data from tunable filter instruments. While we specifically address data from the Optical System for Imaging and low Resolution Integrated Spectroscopy instrument (OSIRIS) on the 10.4-m Gran Telescopio Canarias telescope, our discussion is generalizable to data from other tunable filter instruments. A key aspect of our methodology is a coordinate transformation to polar coordinates, which simplifies matters when the tunable filter data are circularly symmetric around the optical centre. First, we present a method for rectifying inaccuracies in the wavelength calibration using OH sky emission rings. Using this technique, we improve the absolute wavelength calibration from an accuracy of ˜5 to 1 Å, equivalent to ˜7 per cent of our instrumental resolution, for 95 per cent of our data. Then, we discuss a new way to estimate the background sky emission by median filtering in polar coordinates. This method suppresses contributions to the sky background from the outer envelopes of distant galaxies, maximizing the fluxes of sources measured in the corresponding sky-subtracted images. We demonstrate for data tuned to a central wavelength of 7615 Å that galaxy fluxes in the new sky-subtracted image are ˜37 per cent higher, versus a sky-subtracted image from existing methods for OSIRIS tunable filter data.

  4. Digital Tidbits

    ERIC Educational Resources Information Center

    Kumaran, Maha; Geary, Joe

    2011-01-01

    Technology has transformed libraries. There are digital libraries, electronic collections, online databases and catalogs, ebooks, downloadable books, and much more. With free technology such as social websites, newspaper collections, downloadable online calendars, clocks and sticky notes, online scheduling, online document sharing, and online…

  5. Digital Batteries

    NASA Astrophysics Data System (ADS)

    Hubler, Alfred

    2009-03-01

    The energy density in conventional capacitors is limited by sparking. We present nano-capacitor arrays, where - like in laser diodes and quantum wells [1] - quantization prevents dielectric breakthrough. We show that the energy density and the power/weight ratio are very high, possibly larger than in hydrogen [2]. Digital batteries are a potential clean energy source for cars, laptops, and mobile devices. The technology is related to flash drives. However, because of the high energy density, safety is a concern. Digital batteries can be easily and safely charged and discharged. In the discharged state they pose no danger. Even if a charged digital battery were to explode, it would produce no radioactive waste, no long-term radiation, and probably could be designed to produce no noxious chemicals. We discuss methodologies to prevent shorts and other measures to make digital batteries safe. [1] H. Higuraskh, A. Toriumi, F. Yamaguchi, K. Kawamura, A. Hubler, Correlation Tunnel Device, U. S. Patent No. 5,679,961 (1997) [2] Alfred Hubler, http://server10.how-why.com/blog/

  6. Digital books.

    PubMed

    Wink, Diane M

    2011-01-01

    In this bimonthly series, the author examines how nurse educators can use the Internet and Web-based computer technologies such as search, communication, and collaborative writing tools; social networking and social bookmarking sites; virtual worlds; and Web-based teaching and learning programs. This article describes digital books. PMID:22024672

  7. Digital Badges

    ERIC Educational Resources Information Center

    Frederiksen, Linda

    2013-01-01

    Unlike so much of the current vocabulary in education and technology that seems to stir more confusion than clarity, most public service librarians may already have a general idea about digital badges. As visual representations of individual accomplishments, competencies or skills that are awarded by groups, institutions, or organizations, they…

  8. Establishment of intravenous lines for long-term intravenous therapy and monitoring.

    PubMed

    Parsa, M H; Tabora, F

    1985-08-01

    Our experience at this institution indicates that the greater the individual and the institutional experience, the lower the complications of central venous lines. The techniques of double catheter insertions in one vein or region, as described, are safe, cost-effective, and useful. These catheters can remain in place for up to 8 weeks. Insertion of double catheters is ideal for intravenous feeding to avoid premixing amino acids and glucose, thus minimizing the hazards of contamination as well as saving time and cost for mixing. Special unconventional techniques for vascular access when indicated in patients who have limited accessible sites may be lifesaving. Except for fibrinous clots around the catheters, the complications in our series have diminished as our experience has grown. Vascular access techniques and long-term care should be formally taught to committed individuals. Well-trained, concerned, experienced personnel available 24 hours a day, 7 days a week is the most important factor in the reduction of complications of vascular access technique and the long-term maintenance of intravenous lines. PMID:3931265

  9. No space left for intravenous thrombolysis in acute stroke: CONS.

    PubMed

    Muir, Keith

    2016-08-01

    Recent successful clinical trials of endovascular thrombectomy for large artery ischaemic stroke have established the value of this treatment modality as an adjunct to intravenous thrombolysis, not as an alternative: thrombectomy delivery was undertaken in the context of highly efficient networks for acute thrombolysis delivery and the great majority of patients received IV thrombolytic drug treatment. Even for the minority of acute stroke patients for whom thrombectomy is potentially relevant, access will be limited by geography and service infrastructure. Developments in intravenous thrombolysis in the near future will likely produce safer and more effective intravenous treatments. Intravenous thrombolysis will remain the first line of treatment for the great majority of acute stroke patients. PMID:27084182

  10. Gender Differences in Elementary School Children's Strategy Use and Strategy Preferences on Multidigit Addition and Subtraction Story Problems

    ERIC Educational Resources Information Center

    Edwards-Omolewa, Nicola D.

    2011-01-01

    Gender differences in the strategies elementary school children use to solve multidigit addition and subtraction story problems that require regrouping are investigated in two studies. Study 1 replicates the Fennema and colleagues (1998) study by reexamining previously published data on 72 children's addition and subtraction solution strategies.…

  11. Unit-Dose Bags For Formulating Intravenous Solutions

    NASA Technical Reports Server (NTRS)

    Finley, Mike; Kipp, Jim; Scharf, Mike; Packard, Jeff; Owens, Jim

    1993-01-01

    Smaller unit-dose flowthrough bags devised for use with large-volume parenteral (LVP) bags in preparing sterile intravenous solutions. Premeasured amount of solute stored in such unit-dose bag flushed by predetermined amount of water into LVP bag. Relatively small number of LVP bags used in conjunction with smaller unit-dose bags to formulate large number of LVP intravenous solutions in nonsterile environment.

  12. Monitoring of propofol and its metabolite during total intravenous anesthesia

    NASA Astrophysics Data System (ADS)

    Elizarov, A. Yu.; Ershov, T. D.; Levshankov, A. I.

    2011-12-01

    Intravenous hypnotic propofol and its metabolite are detected in real time during total intravenous anesthesia by an electron ionization mass spectrometer. The mass spectrometer is connected directly to the breathing circuit of an apparatus for inhalational anesthesia. Ratios between the propofol concentrations in expired air and blood serum are measured. It is concluded that real-time noninvasive monitoring of the propofol concentration in blood using electron ionization mass spectrometry is feasible.

  13. Computed tomography lung iodine contrast mapping by image registration and subtraction

    NASA Astrophysics Data System (ADS)

    Goatman, Keith; Plakas, Costas; Schuijf, Joanne; Beveridge, Erin; Prokop, Mathias

    2014-03-01

    Pulmonary embolism (PE) is a relatively common and potentially life threatening disease, affecting around 600,000 people annually in the United States alone. Prompt treatment using anticoagulants is effective and saves lives, but unnecessary treatment risks life threatening haemorrhage. The specificity of any diagnostic test for PE is therefore as important as its sensitivity. Computed tomography (CT) angiography is routinely used to diagnose PE. However, there are concerns it may over-report the condition. Additional information about the severity of an occlusion can be obtained from an iodine contrast map that represents tissue perfusion. Such maps tend to be derived from dual-energy CT acquisitions. However, they may also be calculated by subtracting pre- and post-contrast CT scans. Indeed, there are technical advantages to such a subtraction approach, including better contrast-to-noise ratio for the same radiation dose, and bone suppression. However, subtraction relies on accurate image registration. This paper presents a framework for the automatic alignment of pre- and post-contrast lung volumes prior to subtraction. The registration accuracy is evaluated for seven subjects for whom pre- and post-contrast helical CT scans were acquired using a Toshiba Aquilion ONE scanner. One hundred corresponding points were annotated on the pre- and post-contrast scans, distributed throughout the lung volume. Surface-to-surface error distances were also calculated from lung segmentations. Prior to registration the mean Euclidean landmark alignment error was 2.57mm (range 1.43-4.34 mm), and following registration the mean error was 0.54mm (range 0.44-0.64 mm). The mean surface error distance was 1.89mm before registration and 0.47mm after registration. There was a commensurate reduction in visual artefacts following registration. In conclusion, a framework for pre- and post-contrast lung registration has been developed that is sufficiently accurate for lung subtraction

  14. Intravenous lidocaine as a suppressant of coughing during tracheal intubation.

    PubMed

    Yukioka, H; Yoshimoto, N; Nishimura, K; Fujimori, M

    1985-12-01

    Effects of intravenously administered lidocaine on cough suppression during tracheal intubation under general anesthesia were evaluated in two studies. In study 1, 100 patients received either a placebo or 0.5, 1.0, 1.5, or 2.0 mg/kg lidocaine intravenously 1 min before tracheal intubation. All visible coughs were classified as coughing. The incidence of coughing decreased as the dose of lidocaine increased. A dose of 1 mg/kg or more of intravenous lidocaine suppressed the cough reflex significantly (P less than 0.01). Coughing was suppressed completely by 2 mg/kg of intravenous lidocaine. In study 2, 108 patients received 2 mg/kg lidocaine intravenously or a placebo 1, 3, 5, 7, 10, or 15 min before intubation. The same criteria for determining whether a patient did or did not cough during tracheal intubation were used as in study 1. The incidence of coughing decreased significantly (P less than 0.01) when 2 mg/kg of lidocaine was injected intravenously between 1 and 5 min before our attempting intubation. Cough reflex was suppressed completely by plasma concentrations of lidocaine in excess of 3 micrograms/ml. PMID:4061901

  15. Maintenance Intravenous Fluid Prescribing Practices Among Paediatric Residents

    PubMed Central

    Freeman, Michael A; Ayus, Juan C; Moritz, Michael L

    2014-01-01

    Aim To investigate the sodium composition of maintenance intravenous fluids used by paediatric residents throughout the United States in common clinical scenarios of arginine vasopressin excess. Methods We distributed an online survey to paediatric residency programs asking what type of maintenance intravenous fluids (0.2%, 0.45%, 0.9% NaCl or Lactated Ringers) they would administer in four common clinical scenarios of arginine vasopressin excess (gastroenteritis, pneumonia, meningitis and post-operative) in both a 6-month-old (mo) and a 13-year-old (yo) child. Results We had 472 responses, representing 5% of the total paediatric residency population in the US. Hypotonic maintenance intravenous fluids were selected in 78% of children (88.2% of 6 mo and 68.5% of 13 yo). Isotonic maintenance intravenous fluids were selected approximately twice as often for patients with meningitis as for those without (21.4% vs 8.7% 6 mo and 42.8% vs 27.7% 13 yo; p <.0.001). Conclusions The majority of US paediatric residents would prescribe hypotonic maintenance intravenous fluids in disease states associated with arginine vasopressin excess. However, a significant number of residents are using isotonic maintenance intravenous fluids. Isotonic fluids are more likely to be prescribed in older children and children with meningitis. PMID:22765308

  16. Antenna subtraction at NNLO with hadronic initial states : double real radiation for initial-initial configurations with two quark flavours.

    SciTech Connect

    Boughezal, R.; Gehrmann-De Ridder, A.; Ritzmann, M.

    2011-02-01

    The antenna subtraction formalism allows to calculate QCD corrections to jet observables. Within this formalism, the subtraction terms are constructed using antenna functions describing all unresolved radiation between a pair of hard radiator partons. In this paper, we focus on the subtraction terms for double real radiation contributions to jet observables in hadron-hadron collisions evaluated at NNLO. An essential ingredient to these subtraction terms are the four-parton antenna functions with both radiators in the initial state. We outline the construction of the double real subtraction terms, classify all relevant antenna functions and describe their integration over the relevant antenna phase space. For the initial-initial antenna functions with two quark flavours, we derive the phase space master integrals and obtain the integrated antennae.

  17. Intravenous to oral antibiotic switch therapy.

    PubMed

    Cunha, Burke A.

    2001-05-01

    I.v.-to-p.o. switch therapy has become the mainstay of antibiotic therapy for the majority of patients. I.v.-to-p.o. switch therapy is inappropriate for critically ill patients who require i.v. antibiotic therapy and should not be considered in patients who have the inability to absorb drugs. These exceptions constitute a very small percentage of hospitalized patients for which i.v.-to-p.o. switch therapy is ideal. I.v.-to-p.o. switch therapy is best achieved with antibiotics that have high bioavailability that result in the same blood and tissue concentrations of antibiotic as their intravenous counterpart and have few gastrointestinal side effects. Antibiotics ideal for i.v.-to-p.o. switch programs include chloramphenicol, clindamycin, metronidazole, TMP-SMX, fluconazole, itraconazole, voriconazole, doxycycline, minocycline, levofloxacin, gatifloxacin, moxifloxacin and linezolid. Antibiotics that may be used in i.v.-to-p.o. switch programs that have lower bioavailability but are effective include beta-lactams and macrolides. For antibiotics with no oral formulation, e.g., carbapenems, equivalent coverage must be provided with an oral antibiotic from an unrelated class. Excluding gastrointestinal malabsorptive disorders, disease state is not a determinant of suitability for i.v.-to-p.o. switch programs. I.v.-to-p.o. switch programs should be used in patients with any infectious disease disorder for which there is effective oral therapy and is not limited to certain infectious diseases. Oral absorption of antibiotics is near normal in all but the most critically ill patients. Therefore, even in sick, hospitalized individuals, p.o. therapy is appropriate. I.v-to-p.o. switch therapy has several important advantages including decreasing drug cost (i.v. vs. p.o.), decreasing length of stay permitting earlier discharge and optimal reimbursement and decreasing or eliminating i.v. line phlebitis and sepsis with its cost implications. Clinicians should consider all

  18. Total intravenous anesthesia for major burn surgery

    PubMed Central

    Cancio, Leopoldo C; Cuenca, Phillip B; Walker, Stephen C; Shepherd, John M

    2013-01-01

    Total intravenous anesthesia (TIVA) is frequently used for major operations requiring general anesthesia in critically ill burn patients. We reviewed our experience with this approach. Methods: During a 22-month period, 547 major burn surgeries were performed in this center’s operating room and were staffed by full-time burn anesthesiologists. The records of all 123 TIVA cases were reviewed; 112 records were complete and were included. For comparison, 75 cases were selected at random from a total of 414 non-TIVA general anesthetics. Some patients had more than one operation during the study: as appropriate for the analysis in question, each operation or each patient was entered as an individual case. For inter-patient analysis, exposure to 1 or more TIVAs was used to categorize a patient as member of the TIVA group. Results: Excision and grafting comprised 78.2% of the operations. 14 TIVA regimens were used, employing combinations of 4 i.v. drugs: ketamine (K, 91 cases); i.v. methadone (M, 62); fentanyl (F, 58); and propofol (P, 21). The most common regimens were KM (34 cases); KF (26); KMF (16); and K alone (8). Doses used often exceeded those used in non-burn patients. TIVA was preferred for those patients who were more critically ill prior to surgery, with a higher ASA score (3.87 vs. 3.11). Consistent with this, inhalation injury (26.7 vs. 1.6%), burn size (TBSA, 36.3 vs. 15.8%), and full-thickness burn size (FULL, 19.8 vs. 6.5%) were higher in TIVA than in non-TIVA patients. Despite this, intraoperative pressor use was as common in TIVA as in non-TIVA cases (23.9 vs. 22.7%). Conclusions: TIVA was used in patients whose inhalation injury rate and TBSA were greater than those of non-TIVA patients. TIVA cases were not associated with increased hemodynamic instability. TIVA is a viable approach to general anesthesia in critically ill burn patients. PMID:23638329

  19. Closed-Cell Stent-Assisted Coiling of Intracranial Aneurysms: Evaluation of Changes in Vascular Geometry Using Digital Subtraction Angiography

    PubMed Central

    Beller, Ebba; Klopp, David; Göttler, Jens; Kaesmacher, Johannes; Zimmer, Claus; Kirschke, Jan S.; Prothmann, Sascha

    2016-01-01

    Background Stent-assisted coil embolization (SACE) plays an important role in the treatment of intracranial aneurysms. The purpose of this study was to investigate geometrical changes caused by closed-cell design stents in bifurcation and sidewall aneurysms. Methods 31 patients with 34 aneurysms underwent SACE with closed-cell design stents. Inflow angle α, determined by aneurysm neck and afferent vessel, and angle between afferent and efferent vessel close to (δ1), respectively, more remote from the aneurysm neck (δ2) were graphically determined in 2D angiography projections. Results Stent assisted coiling resulted in a significant increase of all three angles from a mean value (±SEM) of α = 119° (±6.5°) pretreatment to 130° (±6.6°) posttreatment (P ≤ .001), δ1 = 129° (±6.4°) to 139° (±6.1°), (P ≤ .001) and δ2 = 115° (±8.4°) to 126° (±7.5°), (P ≤ .01). Angular change of δ1 in AcomA aneurysms was significant greater compared to sidewall aneurysms (26°±4.9° versus 8°± 2.3°, P ≤ .05). The initial angle of δ1 and δ2 revealed a significantly inverse relationship to the angle increase (δ1: r = -0.41, P ≤ .05 and δ2: r = -0.47, P ≤ .01). Moreover, angle δ1 was significantly higher in unruptured compared to ruptured aneurysms (135°±7.1° versus 103°±10.8°, P ≤ .05). Conclusion Stent deployment modulates the geometry of the aneurysm-vessel complex, which may lead to favorable hemodynamic changes more similar to unruptured than to ruptured aneurysms. Our findings also suggest that the more acute-angled aneurysm-vessel anatomy, the larger the angular change. Further studies are needed to investigate whether these changes improve the clinical outcome. PMID:27073908

  20. Grade 3 Students' Mathematization through Modeling: Situation Models and Solution Models with Mutli-Digit Subtraction Problem Solving

    ERIC Educational Resources Information Center

    Murata, Aki; Kattubadi, Sailaja

    2012-01-01

    In considering mathematics problem solving as a model-eliciting activity (Lesh & Doerr, 2003; Lesh & Harel, 2003; Lesh & Zawojewski, 2008), it is important to know "what" students are modeling for the problems: situations or solutions. This study investigated Grade 3 students' mathematization process by examining how they modeled different…

  1. Digital optical processor based on symbolic substitution using holographic matched filtering.

    PubMed

    Jeon, H I; Abushagur, M A; Sawchuk, A A; Jenkins, B K

    1990-05-10

    We propose a digital optical arithmetic processor design based on symbolic substitution using holographic matched and space-invariant filters. The proposed system performs Boolean logic, binary addition, and subtraction in a highly parallel manner; i.e., the processing time depends on word size but not array size. Algorithms for performing binary addition and subtraction in parallel are presented. A skew problem occurring when symbolic substitution is applied to binary addition and subtraction with space-invariant systems is addressed, and its solution is suggested. Crosstalk in symbolic substitution is described, and new symbols which can prevent the crosstalk are introduced. System analysis and fundamental limitations of the proposed system are also presented in terms of processing time, overall light efficiency, and the maximum array size of the input data plane. The performance of the proposed system with that of the current electronic supercomputers has been compared by combining information about the processing time and maximum array size. PMID:20563140

  2. Glucagon-Induced Vasospasm of Hepatic Artery Branches During Visceral Angiography

    SciTech Connect

    Dziedzic, T. Scott; Smith, Tony P.

    2008-07-15

    Glucagon is often used in radiology to decrease bowel motility for enhanced imaging, including visceral digital subtraction angiography. We present a case in which branch hepatic artery vasospasm followed the intravenous administration of glucagon during visceral angiography.

  3. Digital psychiatry.

    PubMed

    Tang, S; Helmeste, D

    2000-02-01

    The American managed care movement has been viewed as a big experiment and is being watched closely by the rest of the world. In the meanwhile, computer-based information technology (IT) is changing the practice of medicine, much more rapidly than managed care. A New World of digitized knowledge and information has been created. Although literature on IT in psychiatry is largely absent in peer-reviewed psychiatric journals, IT is finding its way into all aspects of medicine, particularly psychiatry. Telepsychiatry programs are becoming very popular. At the same time, medical information sites are flourishing and evolving into a new health-care industry. Patient-physician information asymmetry is decreasing as patients are gaining easy access to medical information hitherto only available to professionals. Thus, psychiatry is facing another paradigm shift, at a time when most attention has been focused on managed care. In this new digital world, knowledge and information are no longer the sole property of professionals. Value will migrate from traditional in-person office-based therapy to digital clinical products, from in-person library search and classroom didactic instruction to interactive on-line searches and distance learning. In this time of value migration, psychiatrists have to determine what their 'distinctive competence' is and where best to add value in the health-care delivery value chain. The authors assess the impact of IT on clinical psychiatry and review how clinical practice, education and research in psychiatry are expected to change in this emerging digital world. PMID:15558872

  4. Outcomes and costs of positron emission tomography: comparison of intravenous adenosine and intravenous dipyridamole.

    PubMed

    Holmberg, M J; Mohiuddin, S M; Hilleman, D E; Lucas, B D; Wadibia, E C

    1997-01-01

    The objective of this study was to compare the cost of intravenous adenosine and intravenous dipyridamole in positron emission tomography (PET) in patients with coronary artery disease. A retrospective, open-label, case-control, cost-effectiveness analysis was performed in the out-patient nuclear medicine department of a university hospital. Thirty-six patients underwent dipyridamole PET, and 72 matched patients underwent adenosine PET. A cost-effectiveness analysis was conducted using a direct cost accounting approach to estimate institutional costs. Key costs evaluated included acquisition cost, administration cost, monitoring cost, cost of management of side effects, and cost of follow-up care. The total cost of adenosine PET and dipyridamole PET was divided by their respective predictive accuracies to provide a total cost adjusted for efficacy. Adenosine increased heart rate and lowered systolic blood pressure to a significantly greater extent than dipyridamole. The number of patients experiencing adverse drug reactions was significantly greater for adenosine (82%) than for dipyridamole (67%), but the frequency of prolonged (> 5 minutes) and late-onset side effects was significantly greater for dipyridamole than for adenosine. The frequency of side effects requiring medical intervention was also significantly greater for dipyridamole (53%) than for adenosine (6%). Although adenosine had a significantly greater acquisition cost than dipyridamole, costs of monitoring, management of side effects, and follow-up care were significantly less for adenosine than for dipyridamole. As a result, the total cost of using dipyridamole is significantly greater ($928.00 per patient) than the total cost of using adenosine ($672.00 per patient). Based on these results, adenosine may be the drug of choice for pharmacologic vasodilation for PET. PMID:9220220

  5. [Advantages of digitalization and analysis of roentgenograms of bones by microcomputer.].

    PubMed

    Tkácik, J; Makai, F; Keppert, M; Valko, B

    1994-01-01

    The creation of an experimental group for digitalization of two-dimensional X-ray pictures of bones was the starting point for the application of selected procedures for their computer-assisted analysis. During processing of the picture first the primary digitalized picture was corrected (e. g. subtraction of the background, correction of the non-homogenity of the scanning element and light source) and subsequently the picture was prepared by spot or local transformations (e. g. semithresholding, equalization, Sobel's operator and subtraction of two differently prepared pictures) while preserving the geometry of the original objects on the picture. On treated pictures of bony structures then graphic procedures of identification of important spots, lines, angles and derived indices and of mutual relations of bones were verified. For creation of prerequisites of the long-term development of osseous changes, in particular in patients with non-cemented implants of the hip joints, possibilities of and quantitative requirements of filing of digitalized two-dimensional X-ray pictures of the bones in information media were tested as well as the possibility to transmit them in the local computer network. Finally the authors draw attention to the advantages of digitalization and analysis of two-dimensional X-ray pictures of bones by a microcomputer from the aspect of impact on information, economic aspects and in particular preserving of information in digital form. Key words: digitalization of X-ray pictures, digital processing of X-ray pictures, filing of X-ray pictures. PMID:20444385

  6. THE APPLICATION OF CONTINUOUS WAVELET TRANSFORM BASED FOREGROUND SUBTRACTION METHOD IN 21 cm SKY SURVEYS

    SciTech Connect

    Gu Junhua; Xu Haiguang; Wang Jingying; Chen Wen; An Tao

    2013-08-10

    We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time.

  7. Addition and subtraction of single phonons in a trapped ion system

    NASA Astrophysics Data System (ADS)

    Lv, Dingshun; An, Shuoming; Um, Mark; Lu, Yao; Zhang, Jingning; Kim, Kihwan

    2014-05-01

    We introduce an addition and subtraction of single phonons in a trapped ion system. The creation ↠and annihilation â operation have been realized with photons and used for the complete engineering of quantum states of light and the probe of fundamental quantum phenomena. The mathematical description of photon is identical to that of phonon. However, phonon is a particle of quantized matter wave, which should be interpreted differently from photon. We implement the addition and the subtraction of phonon by applying an anti-Jaynes-Cummings type of operation on our trapped ion and performing projective measurements. Our realization can be used for the accurate measurement of position and momentum as well as their relation. This work was supported by the National Basic Research Program of China Grant 2011CBA00300, 2011CBA00301, 2011CBA00302, the National Natural Science Foundation of China Grant 61073174, 61033001, 61061130540.

  8. An improved dark-object subtraction technique for atmospheric correction of Landsat 8

    NASA Astrophysics Data System (ADS)

    Ding, Huimei; Shi, Junsheng; Wang, Yuanfangzhou; Wei, Li

    2015-12-01

    An improved Dark Object Subtraction (DOS) method was introduced for Landsat 8 multispectral satellite image in this paper. The main factors including Rayleigh scattering, Mie scattering in path radiance, as well as the other satellite image parameters (such as height modification, slope distance and azimuth), ware considered in the algorithm. The algorithm consists of three steps. First, starting band haze values are selected using histogram of a single image. Then predicted haze values were calculated using a known scattering model and the multispectral normalized gains and offset values. Finally, final predicted haze values are obtained by the predicted haze values and haze values. Compared with other improved Dark Object Subtraction methods, the result of this algorithm is more realistic on geographical object recognition on NDVI (Normalized Difference Vegetation Index) and NDWI (Normalized Difference Water Index) data.

  9. The Application of Continuous Wavelet Transform Based Foreground Subtraction Method in 21 cm Sky Surveys

    NASA Astrophysics Data System (ADS)

    Gu, Junhua; Xu, Haiguang; Wang, Jingying; An, Tao; Chen, Wen

    2013-08-01

    We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time.

  10. Intravenously administered vitamin C as cancer therapy: three cases.

    PubMed

    Padayatty, Sebastian J; Riordan, Hugh D; Hewitt, Stephen M; Katz, Arie; Hoffer, L John; Levine, Mark

    2006-03-28

    Early clinical studies showed that high-dose vitamin C, given by intravenous and oral routes, may improve symptoms and prolong life in patients with terminal cancer. Double-blind placebo-controlled studies of oral vitamin C therapy showed no benefit. Recent evidence shows that oral administration of the maximum tolerated dose of vitamin C (18 g/d) produces peak plasma concentrations of only 220 micromol/L, whereas intravenous administration of the same dose produces plasma concentrations about 25-fold higher. Larger doses (50-100 g) given intravenously may result in plasma concentrations of about 14,000 micromol/L. At concentrations above 1000 micromol/L, vitamin C is toxic to some cancer cells but not to normal cells in vitro. We found 3 well-documented cases of advanced cancers, confirmed by histopathologic review, where patients had unexpectedly long survival times after receiving high-dose intravenous vitamin C therapy. We examined clinical details of each case in accordance with National Cancer Institute (NCI) Best Case Series guidelines. Tumour pathology was verified by pathologists at the NCI who were unaware of diagnosis or treatment. In light of recent clinical pharmacokinetic findings and in vitro evidence of anti-tumour mechanisms, these case reports indicate that the role of high-dose intravenous vitamin C therapy in cancer treatment should be reassessed. PMID:16567755

  11. Intravenously administered vitamin C as cancer therapy: three cases

    PubMed Central

    Padayatty, Sebastian J.; Riordan, Hugh D.; Hewitt, Stephen M.; Katz, Arie; Hoffer, L. John; Levine, Mark

    2006-01-01

    Early clinical studies showed that high-dose vitamin C, given by intravenous and oral routes, may improve symptoms and prolong life in patients with terminal cancer. Double-blind placebo-controlled studies of oral vitamin C therapy showed no benefit. Recent evidence shows that oral administration of the maximum tolerated dose of vitamin C (18 g/d) produces peak plasma concentrations of only 220 μmol/L, whereas intravenous administration of the same dose produces plasma concentrations about 25-fold higher. Larger doses (50–100 g) given intravenously may result in plasma concentrations of about 14 000 μmol/L. At concentrations above 1000 μmol/L, vitamin C is toxic to some cancer cells but not to normal cells in vitro. We found 3 well-documented cases of advanced cancers, confirmed by histopathologic review, where patients had unexpectedly long survival times after receiving high-dose intravenous vitamin C therapy. We examined clinical details of each case in accordance with National Cancer Institute (NCI) Best Case Series guidelines. Tumour pathology was verified by pathologists at the NCI who were unaware of diagnosis or treatment. In light of recent clinical pharmacokinetic findings and in vitro evidence of anti-tumour mechanisms, these case reports indicate that the role of high-dose intravenous vitamin C therapy in cancer treatment should be reassessed. PMID:16567755

  12. Long-Term Efficacy of Postpartum Intravenous Iron Therapy

    PubMed Central

    Zimmermann, Roland

    2014-01-01

    Background. The potential benefits of administering a dose of intravenous iron in patients with moderate postpartum anaemia rather than oral iron alone remains unproven. Aims. To determine whether a single injection of intravenous iron followed by a 6-week course of oral iron is as effective over 6 months in restoring normal haemoglobin levels and replenishing iron stores in women with moderate postpartum anaemia as a course of oral iron alone in women with mild postpartum anaemia. Materials and Methods. Retrospective two-arm cohort study in women with mild postpartum anaemia (haemoglobin 9.6–10.5 g/dL) prescribed iron daily for 6 weeks (N = 150) and women with moderate postpartum anaemia (haemoglobin 8.5–9.5 g/dL), given a single 500 mg injection of intravenous iron followed by iron daily for 6 weeks (N = 75). Haemoglobin and ferritin were measured 6 months postpartum. Results. Haemoglobin returned to similar mean levels in both groups. Ferritin levels were statistically significantly higher in the intravenous + oral group (57.7 ± 49.3 μg/L versus 32.9 ± 20.1 μg/L). Conclusions. Despite lower baseline haemoglobin, intravenous iron carboxymaltose was superior to oral iron alone in replenishing iron stores in moderate postpartum anaemia and may prove similarly beneficial in mild postpartum anaemia. PMID:25431768

  13. Intravenous ferric carboxymaltose for the treatment of iron deficiency anemia

    PubMed Central

    Friedrisch, João Ricardo; Cançado, Rodolfo Delfini

    2015-01-01

    Nutritional iron deficiency anemia is the most common deficiency disorder, affecting more than two billion people worldwide. Oral iron supplementation is usually the first choice for the treatment of iron deficiency anemia, but in many conditions, oral iron is less than ideal mainly because of gastrointestinal adverse events and the long course needed to treat the disease and replenish body iron stores. Intravenous iron compounds consist of an iron oxyhydroxide core, which is surrounded by a carbohydrate shell made of polymers such as dextran, sucrose or gluconate. The first iron product for intravenous use was the high molecular weight iron dextran. However, dextran-containing intravenous iron preparations are associated with an elevated risk of anaphylactic reactions, which made physicians reluctant to use intravenous iron for the treatment of iron deficiency anemia over many years. Intravenous ferric carboxymaltose is a stable complex with the advantage of being non-dextran-containing and a very low immunogenic potential and therefore not predisposed to anaphylactic reactions. Its properties permit the administration of large doses (15 mg/kg; maximum of 1000 mg/infusion) in a single and rapid session (15-minute infusion) without the requirement of a test dose. The purpose of this review is to discuss some pertinent issues in relation to the history, pharmacology, administration, efficacy, and safety profile of ferric carboxymaltose in the treatment of patients with iron deficiency anemia. PMID:26670403

  14. Intravenous ferric carboxymaltose for the treatment of iron deficiency anemia.

    PubMed

    Friedrisch, João Ricardo; Cançado, Rodolfo Delfini

    2015-01-01

    Nutritional iron deficiency anemia is the most common deficiency disorder, affecting more than two billion people worldwide. Oral iron supplementation is usually the first choice for the treatment of iron deficiency anemia, but in many conditions, oral iron is less than ideal mainly because of gastrointestinal adverse events and the long course needed to treat the disease and replenish body iron stores. Intravenous iron compounds consist of an iron oxyhydroxide core, which is surrounded by a carbohydrate shell made of polymers such as dextran, sucrose or gluconate. The first iron product for intravenous use was the high molecular weight iron dextran. However, dextran-containing intravenous iron preparations are associated with an elevated risk of anaphylactic reactions, which made physicians reluctant to use intravenous iron for the treatment of iron deficiency anemia over many years. Intravenous ferric carboxymaltose is a stable complex with the advantage of being non-dextran-containing and a very low immunogenic potential and therefore not predisposed to anaphylactic reactions. Its properties permit the administration of large doses (15mg/kg; maximum of 1000mg/infusion) in a single and rapid session (15-minute infusion) without the requirement of a test dose. The purpose of this review is to discuss some pertinent issues in relation to the history, pharmacology, administration, efficacy, and safety profile of ferric carboxymaltose in the treatment of patients with iron deficiency anemia. PMID:26670403

  15. THE IMPACT OF POINT-SOURCE SUBTRACTION RESIDUALS ON 21 cm EPOCH OF REIONIZATION ESTIMATION

    SciTech Connect

    Trott, Cathryn M.; Wayth, Randall B.; Tingay, Steven J.

    2012-09-20

    Precise subtraction of foreground sources is crucial for detecting and estimating 21 cm H I signals from the Epoch of Reionization (EoR). We quantify how imperfect point-source subtraction due to limitations of the measurement data set yields structured residual signal in the data set. We use the Cramer-Rao lower bound, as a metric for quantifying the precision with which a parameter may be measured, to estimate the residual signal in a visibility data set due to imperfect point-source subtraction. We then propagate these residuals into two metrics of interest for 21 cm EoR experiments-the angular power spectrum and two-dimensional power spectrum-using a combination of full analytic covariant derivation, analytic variant derivation, and covariant Monte Carlo simulations. This methodology differs from previous work in two ways: (1) it uses information theory to set the point-source position error, rather than assuming a global rms error, and (2) it describes a method for propagating the errors analytically, thereby obtaining the full correlation structure of the power spectra. The methods are applied to two upcoming low-frequency instruments that are proposing to perform statistical EoR experiments: the Murchison Widefield Array and the Precision Array for Probing the Epoch of Reionization. In addition to the actual antenna configurations, we apply the methods to minimally redundant and maximally redundant configurations. We find that for peeling sources above 1 Jy, the amplitude of the residual signal, and its variance, will be smaller than the contribution from thermal noise for the observing parameters proposed for upcoming EoR experiments, and that optimal subtraction of bright point sources will not be a limiting factor for EoR parameter estimation. We then use the formalism to provide an ab initio analytic derivation motivating the 'wedge' feature in the two-dimensional power spectrum, complementing previous discussion in the literature.

  16. Maximal Abelian and Curci-Ferrari gauges in momentum subtraction at three loops

    NASA Astrophysics Data System (ADS)

    Bell, J. M.; Gracey, J. A.

    2015-12-01

    The vertex structure of QCD fixed in the maximal Abelian gauge (MAG) and Curci-Ferrari gauge is analyzed at two loops at the fully symmetric point for the 3-point functions corresponding to the three momentum subtraction (MOM) renormalization schemes. Consequently, the three-loop renormalization group functions are determined for each of these three schemes in each gauge using properties of the renormalization group equation.

  17. Fingerprinting the Asterid Species Using Subtracted Diversity Array Reveals Novel Species-Specific Sequences

    PubMed Central

    Mantri, Nitin; Olarte, Alexandra; Li, Chun Guang; Xue, Charlie; Pang, Edwin C. K.

    2012-01-01

    Background Asterids is one of the major plant clades comprising of many commercially important medicinal species. One of the major concerns in medicinal plant industry is adulteration/contamination resulting from misidentification of herbal plants. This study reports the construction and validation of a microarray capable of fingerprinting medicinally important species from the Asterids clade. Methodology/Principal Findings Pooled genomic DNA of 104 non-asterid angiosperm and non-angiosperm species was subtracted from pooled genomic DNA of 67 asterid species. Subsequently, 283 subtracted DNA fragments were used to construct an Asterid-specific array. The validation of Asterid-specific array revealed a high (99.5%) subtraction efficiency. Twenty-five Asterid species (mostly medicinal) representing 20 families and 9 orders within the clade were hybridized onto the array to reveal its level of species discrimination. All these species could be successfully differentiated using their hybridization patterns. A number of species-specific probes were identified for commercially important species like tea, coffee, dandelion, yarrow, motherwort, Japanese honeysuckle, valerian, wild celery, and yerba mate. Thirty-seven polymorphic probes were characterized by sequencing. A large number of probes were novel species-specific probes whilst some of them were from chloroplast region including genes like atpB, rpoB, and ndh that have extensively been used for fingerprinting and phylogenetic analysis of plants. Conclusions/Significance Subtracted Diversity Array technique is highly efficient in fingerprinting species with little or no genomic information. The Asterid-specific array could fingerprint all 25 species assessed including three species that were not used in constructing the array. This study validates the use of chloroplast genes for bar-coding (fingerprinting) plant species. In addition, this method allowed detection of several new loci that can be explored to solve

  18. Engineering of Schroedinger cat states by a sequence of displacements and photon additions or subtractions

    SciTech Connect

    Podoshvedov, S. A.

    2011-04-15

    A method to generate Schroedinger cat states in free propagating optical fields based on the use of displaced states (or displacement operators) is developed. Some optical schemes with photon-added coherent states are studied. The schemes are modifications of the general method based on a sequence of displacements and photon additions or subtractions adjusted to generate Schroedinger cat states of a larger size. The effects of detection inefficiency are taken into account.

  19. Temporal subtraction system on torso FDG-PET scans based on statistical image analysis

    NASA Astrophysics Data System (ADS)

    Shimizu, Yusuke; Hara, Takeshi; Fukuoka, Daisuke; Zhou, Xiangrong; Muramatsu, Chisako; Ito, Satoshi; Hakozaki, Kenta; Kumita, Shin-ichiro; Ishihara, Kei-ichi; Katafuchi, Tetsuro; Fujita, Hiroshi

    2013-02-01

    Diagnostic imaging on FDG-PET scans was often used to evaluate chemotherapy results of cancer patients. Radiologists compare the changes of lesions' activities between previous and current examinations for the evaluation. The purpose of this study was to develop a new computer-aided detection (CAD) system with temporal subtraction technique for FDGPET scans and to show the fundamental usefulness based on an observer performance study. Z-score mapping based on statistical image analysis was newly applied to the temporal subtraction technique. The subtraction images can be obtained based on the anatomical standardization results because all of the patients' scans were deformed into standard body shape. An observer study was performed without and with computer outputs to evaluate the usefulness of the scheme by ROC (receiver operating characteristics) analysis. Readers responded as confidence levels on a continuous scale from absolutely no change to definitely change between two examinations. The recognition performance of the computer outputs for the 43 pairs was 96% sensitivity with 31.1 false-positive marks per scan. The average of area-under-the-ROC-curve (AUC) from 4 readers in the observer performance study was increased from 0.85 without computer outputs to 0.90 with computer outputs (p=0.0389, DBM-MRMC). The average of interpretation time was slightly decreased from 42.11 to 40.04 seconds per case (p=0.625, Wilcoxon test). We concluded that the CAD system for torso FDG-PET scans with temporal subtraction technique might improve the diagnostic accuracy of radiologist in cancer therapy evaluation.

  20. At near-infrared wavelengths, following the subtraction of zodiacal light

    NASA Technical Reports Server (NTRS)

    2002-01-01

    At near-infrared wavelengths, following the subtraction of zodiacal light (see Slide 16), map pixels containing discrete bright sources are masked and the DIRBE Faint Source Model is used to subtract residual Galactic starlight in order to detect or place an upper limit on the brightness of the cosmic infrared (extragalactic) background emission (Arendt et al. 1998, ApJ, in press). Here the upper map shows the residual sky brightness at 2.2 Aum after zodiacal light subtraction and bright source masking (dark spots in maps). In this projection, the Galactic plane runs horizontally through the map. Ideally, if the zodiacal model were perfect, only the collective emissions of (faint) stars in the Milky Way and the sought-after extragalactic light (cosmic infrared background) would remain in this map. The lower map shows the DIRBE Faint Source Model. To facilitate comparison, both maps are shown on the same brightness scale and with the same pixels masked. Clearly, most of the residual 2.2 Aum emission in the upper map is attributable to stars in the Milky Way.

  1. Fast washout of thallium-201 from area of myocardial infarction: possible artifact of background subtraction

    SciTech Connect

    Brown, K.A.; Benoit, L.; Clements, J.P.; Wackers, F.J.

    1987-06-01

    A recent report described a pattern of reverse redistribution on poststreptokinase /sup 201/Tl studies which was believed to be due to rapid washout of /sup 201/Tl from the infarct area related to reperfusion of the infarct vessel. We have also observed the phenomenon of rapid washout of /sup 201/Tl from the area of infarction in the absence of thrombolytic therapy. This study was undertaken to test the hypothesis that rapid washout of /sup 201/Tl from an area of infarction is an artifact of background subtraction usually employed in analysis of washout. A total of 61 patients with previous myocardial infarction who underwent cardiac catheterization and exercise /sup 201/Tl imaging were examined. Thallium-201 images were analyzed using a validated quantitative method employing interpolative background correction. Abnormally increased /sup 201/Tl washout was noted in 11 infarct segments in 10 (18%) patients. Infarct segments with rapid washout had significantly less initial uptake, and more severe associated wall motion abnormalities than infarct segments with normal washout. When quantitative analysis was repeated without background subtraction, no segments with rapid washout were observed. A phantom model was constructed to further test our hypothesis. The frequency of observed rapid washout was directly related to the severity of the initial defect and was entirely dependent upon utilizing background correction during the quantitative analysis. Our study suggests that rapid washout of /sup 201/Tl in an area of previous infarction reflects an artifact of background subtraction involved with standard quantitative analysis.

  2. Removing ECG Artifact from the Surface EMG Signal Using Adaptive Subtraction Technique

    PubMed Central

    Abbaspour, S; Fallah, A

    2014-01-01

    Background: The electrocardiogram artifact is a major contamination in the electromyogram signals when electromyogram signal is recorded from upper trunk muscles and because of that the contaminated electromyogram is not useful. Objective: Removing electrocardiogram contamination from electromyogram signals. Methods: In this paper, the clean electromyogram signal, electrocardiogram artifact and electrocardiogram signal were recorded from leg muscles, the pectoralis major muscle of the left side and V4, respectively. After the pre-processing, contaminated electromyogram signal is simulated with a combination of clean electromyogram and electrocardiogram artifact. Then, contaminated electromyogram is cleaned using adaptive subtraction method. This method contains some steps; (1) QRS detection, (2) formation of electrocardiogram template by averaging the electrocardiogram complexes, (3) using low pass filter to remove undesirable artifacts, (4) subtraction. Results: Performance of our method is evaluated using qualitative criteria, power spectrum density and coherence and quantitative criteria signal to noise ratio, relative error and cross correlation. The result of signal to noise ratio, relative error and cross correlation is equal to 10.493, 0.04 and %97 respectively. Finally, there is a comparison between proposed method and some existing methods. Conclusion: The result indicates that adaptive subtraction method is somewhat effective to remove electrocardiogram artifact from contaminated electromyogram signal and has an acceptable result. PMID:25505766

  3. Optimization of thermal ghost imaging: high-order correlations vs. background subtraction.

    PubMed

    Chan, Kam Wai C; O'Sullivan, Malcolm N; Boyd, Robert W

    2010-03-15

    We compare the performance of high-order thermal ghost imaging with that of conventional (that is, lowest-order) thermal ghost imaging for different data processing methods. Particular attention is given to high-order thermal ghost imaging with background normalization and conventional ghost imaging with background subtraction. The contrast-to-noise ratio (CNR) of the ghost image is used as the figure of merit for the comparison.We find analytically that the CNR of the normalized high-order ghost image is inversely proportional to the square root of the number of transmitting pixels of the object. This scaling law is independent of the exponents used in calculating the high-order correlation and is the same as that of conventional ghost imaging with background subtraction. We find that no data processing procedure performs better than lowest-order ghost imaging with background subtraction. Our results are found to be able to explain the observations of a recent experiment [Chen et al., arXiv:0902.3713v3 [quant-ph

  4. Clustered breast microcalcifications: Evaluation by dynamic contrast-enhanced subtraction MRI

    SciTech Connect

    Gilles, R.; Tardivon, A.A.; Vanel, D.; Guinebretiere, J.M.; Arriagada, R.

    1996-01-01

    Our goal was to evaluate dynamic contrast-enhanced subtraction MRI in the diagnosis of isolated clustered calcifications of the breast. One hundred seventy-two patients underwent surgical biopsy for isolated clustered breast calcifications. Their mammograms showed round (n = 88) or linear/irregular (n = 84) microcalcifications. All patients had a preoperative Gd-DOTA-enhanced subtraction dynamic study. Any early contrast enhancement in the breast parenchyma concomitant with early enhancement of normal vessels was considered positive. Fifty-eight in situ carcinomas, 22 invasive carcinomas, and 92 benign lesions were found at histological analysis. Dynamic MR sequences showed early contrast enhancement in 76 of 80 malignant lesions (sensitivity 95%) and in 45 of 92 benign lesions (specificity 51%). Two invasive and two intraductal carcinomas did not show early contrast enhancement. Three independent observers agreed in rating early contrast enhancement in 143 of 172 lesions. Poor specificity limits the diagnostic accuracy of dynamic contrast-enhanced subtraction MRI in distinguishing benign from malignant microcalcifications on mammography. 8 refs., 2 figs., 2 tabs.

  5. [Utility of noise addition image made by using water phantom and image addition and subtraction software].

    PubMed

    Watanabe, Ryo; Ogawa, Masato; Mituzono, Hiroki; Aoki, Takahiro; Hayano, Mizuho; Watanabe, Yuka

    2010-08-20

    In optimizing exposures, it is very important to evaluate the impact of image noise on image quality. To realize this, there is a need to evaluate how much image noise will make the subject disease invisible. But generally it is very difficult to shoot images of different quality in a clinical examination. Thus, a method to create a noise addition image by adding the image noise to raw data has been reported. However, this approach requires a special system, so it is difficult to implement in many facilities. We have invented a method to easily create a noise addition image by using the water phantom and image add-subtract software that accompanies the device. To create a noise addition image, first we made a noise image by subtracting the water phantom with different SD. A noise addition image was then created by adding the noise image to the original image. By using this method, a simulation image with intergraded SD can be created from the original. Moreover, the noise frequency component of the created noise addition image is as same as the real image. Thus, the relationship of image quality to SD in the clinical image can be evaluated. Although this method is an easy method of LDSI creation on image data, a noise addition image can be easily created by using image addition and subtraction software and water phantom, and this can be implemented in many facilities. PMID:20953102

  6. Mysterious Subtractions

    ERIC Educational Resources Information Center

    Hillen, Amy F.; Watanabe, Tad

    2013-01-01

    Recent documents suggest that all students, even young children, should have opportunities to engage in reasoning and proof (CCSSI 2010; NCTM 2000, 2006, 2009). One mathematical practice that is central to reasoning and proof is making conjectures (CCSSI 2010; NCTM 2000; Stylianides 2008). In the elementary grades, "formulating conjectures…

  7. Asymmetric generalization and interaction profiles in rhesus monkeys discriminating intravenous cocaine or intravenous heroin from vehicle.

    PubMed

    Platt, Donna M; Rowlett, James K; Spealman, Roger D

    2010-03-01

    Many polydrug abusers combine cocaine with heroin in the form of a "speedball." This study investigated the discriminative stimulus (DS) effects of speedballs in rhesus monkeys trained to discriminate either intravenous cocaine or intravenous heroin from vehicle. Initial substitution tests revealed an asymmetry in the generalization profile of dopamine and opioid agonists such that mu agonists partially substituted for cocaine, but direct and indirect dopamine agonists did not substitute for heroin. Subsequent speedball tests in which drug mixtures were administered by coinjecting the component drugs while keeping the dose-ratio constant revealed an additional asymmetry. In cocaine-trained monkeys, coadministration of cocaine and heroin produced leftward shifts in the cocaine dose-response function. Heroin's cocaine-enhancing effects were mimicked by the mu agonists fentanyl and methadone and less consistently by the delta agonist (+)-4-[(alphaR)-alpha-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide (SNC 80) and reversed by the mu antagonist naltrexone and the delta antagonist naltrindole. In heroin-trained monkeys, coadministration of cocaine and heroin attenuated the DS effects of heroin. Cocaine's heroin-attenuating effects were mimicked by the D1-like agonist 6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine (SKF 81297) and the D2-like agonist R-(-)-propylnorapomorphine and reversed by the D1-like antagonist (6aS-trans)-11-chloro-6,6a,7,8,9,13b-hexahydro-7-methyl-5H- benzo[d] aphtha[2,1-b]azepin-12-ol hydrobromide (SCH 39166) and the D2-like antagonist raclopride. Attenuation of the effects of heroin was accompanied by decreases in response rate. These results suggest that heroin enhances the DS effects of cocaine via mu, and to a lesser extent delta, receptor mechanisms; whereas cocaine-induced inhibition of the DS effects of heroin probably was due at least in part to masking of the heroin DS presumably

  8. Heparin is not required for peripheral intravenous locks in neonates

    PubMed Central

    Brown, Krista; Tay-Uyboco, Jean S; McMillan, Douglas D

    1999-01-01

    OBJECTIVE: To determine the relative efficacy and safety of peripheral intravenous locks maintained with heparin saline solutions compared with those maintained with normal saline. DESIGN: Randomized, controlled trial comparing the two methods of maintaining peripheral intravenous locks. SETTING: Infants in the neonatal intensive care unit (NICU) at Foothills Hospital, Calgary, Alberta. PATIENTS: Neonates requiring the maintenance of intravenous locks for medications, primarily antibiotics, were randomly placed in either a heparin saline (n=93) or normal saline (n=93) group. INTERVENTIONS: Patients were chosen to receive either heparinized saline (5 units/mL) or normal saline, 0.3 mL in the intravenous catheter every 6 h, administered by nursing staff in a blinded manner. RESULTS: There was no difference in catheter lifespan (39±24 h for the heparinized saline group; 34±22 h for the normal saline group) and no difference in the number of intravenous catheters per patient (1.9 heparinized group, 1.6 normal saline group). There were no differences in the reasons for catheter removal, complications at the skin site or systemic bleeding including intracranial hemorrhage between the two groups. The risk of catheter occlusion was inversely correlated with gestational age and the administration of vancomycin and cefotaxime versus ampicillin and gentamicin. CONCLUSIONS: Heparin is not required for the maintenance of peripheral intravenous locks in neonates regardless of the solution used. Catheter occlusion is more likely to be associated with a low gestational age and the administration of vancomycin and cefotaxime versus ampicillin and gentamicin. PMID:20212988

  9. Scanning for Digitization Projects

    ERIC Educational Resources Information Center

    Wentzel, Larry

    2007-01-01

    Librarians and archivists find themselves facing the prospect of digitization. Everyone is doing it, everyone needs it. Discussions rage nationally and internationally concerning what to digitize and the best means to present and retain digital objects. Digitization is the act of making something digital, expressing a physical object "in numerical…

  10. Suicide by injecting lispro insulin with an intravenous cannula.

    PubMed

    Behera, C; Swain, Rajanikanta; Mridha, Asit Ranjan; Pooniya, Shashank

    2015-09-01

    Suicide by injecting insulin is not uncommon both in diabetic and non-diabetic people. The victim usually uses an insulin syringe or a traditional syringe attached to a needle for the injection of insulin, of either animal or synthetic origin. We report a case of suicide by a non-diabetic physician by injecting lispro insulin through an intravenous cannula. To the best of our knowledge, the use of an intravenous cannula for the injection of insulin for suicide is unusual and is rarely reported in the medico-legal literature. PMID:25748289

  11. Safe intravenous thrombolysis in acute stroke despite treatment with rivaroxaban.

    PubMed

    Bornkamm, Katharina; Harloff, Andreas

    2014-11-01

    Data regarding intravenous thrombolysis in stroke patients receiving new oral anticoagulant drugs (nOAC) is sparse. In the near future, however, an increasing number of patients with atrial fibrillation will suffer recurrent stroke despite treatment with nOAC. This will cause a significant therapeutic dilemma as thrombolysis is contraindicated under such circumstances. We describe an 81-year-old patient presenting with acute ischemic stroke who was successfully treated with intravenous thrombolysis despite ongoing treatment with rivaroxaban. Our case report indicates that thrombolysis under nOAC may be safe under certain conditions and emphasizes the importance of establishing and performing specific anticoagulation tests for nOAC. PMID:24938385

  12. Intramuscular versus Intravenous Therapy for Prehospital Status Epilepticus

    PubMed Central

    Silbergleit, Robert; Durkalski, Valerie; Lowenstein, Daniel; Conwit, Robin; Pancioli, Arthur; Palesch, Yuko; Barsan, William

    2012-01-01

    BACKGROUND Early termination of prolonged seizures with intravenous administration of benzodiazepines improves outcomes. For faster and more reliable administration, paramedics increasingly use an intramuscular route. METHODS This double-blind, randomized, noninferiority trial compared the efficacy of intramuscular midazolam with that of intravenous lorazepam for children and adults in status epilepticus treated by paramedics. Subjects whose convulsions had persisted for more than 5 minutes and who were still convulsing after paramedics arrived were given the study medication by either intramuscular autoinjector or intravenous infusion. The primary outcome was absence of seizures at the time of arrival in the emergency department without the need for rescue therapy. Secondary outcomes included endotracheal intubation, recurrent seizures, and timing of treatment relative to the cessation of convulsive seizures. This trial tested the hypothesis that intramuscular midazolam was noninferior to intravenous lorazepam by a margin of 10 percentage points. RESULTS At the time of arrival in the emergency department, seizures were absent without rescue therapy in 329 of 448 subjects (73.4%) in the intramuscular-midazolam group and in 282 of 445 (63.4%) in the intravenous-lorazepam group (absolute difference, 10 percentage points; 95% confidence interval, 4.0 to 16.1; P<0.001 for both noninferiority and superiority). The two treatment groups were similar with respect to need for endotracheal intubation (14.1% of subjects with intramuscular midazolam and 14.4% with intravenous lorazepam) and recurrence of seizures (11.4% and 10.6%, respectively). Among subjects whose seizures ceased before arrival in the emergency department, the median times to active treatment were 1.2 minutes in the intramuscular-midazolam group and 4.8 minutes in the intravenous-lorazepam group, with corresponding median times from active treatment to cessation of convulsions of 3.3 minutes and 1.6 minutes

  13. Anaphylaxis following intravenous paracetamol: the problem is the solution.

    PubMed

    Jain, S S; Green, S; Rose, M

    2015-11-01

    Paracetamol is a ubiquitous analgesic and antipyretic that is widely administered, including by anaesthetists. Immediate hypersensitivity reactions to intravenous paracetamol are particularly rare. We report two cases involving four separate episodes of anaphylaxis to intravenous paracetamol in different perioperative settings without a past history of intolerance to the oral form. The allergological investigations are described, during which it became evident that both patients were allergic to an excipient (mannitol) present in the formulation and that neither was allergic to the principal agent (paracetamol). The importance of referral and investigation of perioperative drug reactions is underscored by these two cases. PMID:26603804

  14. [The development of multifunction intravenous infusion quantitative packaging device].

    PubMed

    Zhao, Shufang; Li, Ruihua; Shen, Lianhong

    2012-11-01

    Aimed at tackling the compatibility issues arising from the drug reaction in intravenous infusion tube, we developed a simple, suitable and multi-function intravenous infusion tube for the special use for rescuing critical patients, the elderly, children etc. Each drug in a transfusion process can be filtered to realize quantitative packet and packet delivery. Thus, the drugs in the infusion tube are prevented from meeting with each other. No overlap, no particle pollution occurred. Stable performance and accurate dosage are maintained. As a result safety is ensured during drug delivery. PMID:23461118

  15. A comparative study of intravenous paracetamol and intravenous tramadol for postoperative analgesia in laparotomies

    PubMed Central

    Shahid, Mohammed; Manjula, B. P.; Sunil, B. V.

    2015-01-01

    Background: Pain in the perioperative setting or thereafter plays a significant role in delaying an otherwise successful recovery. Hence, mitigation of such postoperative pain assumes importance. Among the various agents employed for such mitigation, opioids and non-steroidal anti-inflammatory drugs have for some time taken center stage. However, alas they are not without their share of adverse effects. This study was undertaken with the purpose of elucidating the efficacy of intravenous (IV) paracetamol as compared to IV tramadol in mitigating postoperative pain while observing its effect on hemodynamic stability and the presence of adverse drug reactions, if any. Materials and Methods: A total of 60 randomized cases aged ranges from 20 to 60 years of both sexes divided into two groups (each for paracetamol and tramadol) scheduled for laparotomies were administered IV paracetamol and tramadol for postoperative pain relief and assessed with visual analog scale (VAS) score and variations in vital parameters to ascertain extent of pain relief and post-operative nausea vomiting (PONV). Results: Data so collected was statistically interpreted, and observations extrapolated. Save for a perceptible decline in PONV with paracetamol group compared with tramadol group with a statistically significant P < 0.001, nothing statistically significant was observed in any other parameter, including VAS scores between either group. Conclusion: IV paracetamol is a safer alternative to tramadol with lesser PONV in the postoperative period translates into the lesser duration of hospitalization and hence earlier discharge. PMID:26712966

  16. Generation of optical coherent-state superpositions by number-resolved photon subtraction from the squeezed vacuum

    SciTech Connect

    Gerrits, Thomas; Glancy, Scott; Clement, Tracy S.; Calkins, Brice; Lita, Adriana E.; Nam, Sae Woo; Mirin, Richard P.; Knill, Emanuel; Miller, Aaron J.; Migdall, Alan L.

    2010-09-15

    We have created heralded coherent-state superpositions (CSSs) by subtracting up to three photons from a pulse of squeezed vacuum light. To produce such CSSs at a sufficient rate, we used our high-efficiency photon-number-resolving transition edge sensor to detect the subtracted photons. This experiment is enabled by and utilizes the full photon-number-resolving capabilities of this detector. The CSS produced by three-photon subtraction had a mean-photon number of 2.75{sub -0.24}{sup +0.06} and a fidelity of 0.59{sub -0.14}{sup +0.04} with an ideal CSS. This confirms that subtracting more photons results in higher-amplitude CSSs.

  17. Correction of Atmospheric Haze in RESOURCESAT-1 LISS-4 MX Data for Urban Analysis: AN Improved Dark Object Subtraction Approach

    NASA Astrophysics Data System (ADS)

    Mustak, S.

    2013-09-01

    The correction of atmospheric effects is very essential because visible bands of shorter wavelength are highly affected by atmospheric scattering especially of Rayleigh scattering. The objectives of the paper is to find out the haze values present in the all spectral bands and to correct the haze values for urban analysis. In this paper, Improved Dark Object Subtraction method of P. Chavez (1988) is applied for the correction of atmospheric haze in the Resoucesat-1 LISS-4 multispectral satellite image. Dark object Subtraction is a very simple image-based method of atmospheric haze which assumes that there are at least a few pixels within an image which should be black (% reflectance) and such black reflectance termed as dark object which are clear water body and shadows whose DN values zero (0) or Close to zero in the image. Simple Dark Object Subtraction method is a first order atmospheric correction but Improved Dark Object Subtraction method which tends to correct the Haze in terms of atmospheric scattering and path radiance based on the power law of relative scattering effect of atmosphere. The haze values extracted using Simple Dark Object Subtraction method for Green band (Band2), Red band (Band3) and NIR band (band4) are 40, 34 and 18 but the haze values extracted using Improved Dark Object Subtraction method are 40, 18.02 and 11.80 for aforesaid bands. Here it is concluded that the haze values extracted by Improved Dark Object Subtraction method provides more realistic results than Simple Dark Object Subtraction method.

  18. Visualized measurement of the acoustic levitation field based on digital holography with phase multiplication

    NASA Astrophysics Data System (ADS)

    Zheng, Puchao; Li, Enpu; Zhao, Jianlin; Di, Jianglei; Zhou, Wangmin; Wang, Hao; Zhang, Ruifeng

    2009-11-01

    By using digital holographic interferometory with phase multiplication, the visualized measurement of the acoustic levitation field (ALF) with single axis is carried out. The digital holograms of the ALF under different conditions are recorded by use of CCD. The corresponding digital holographic interferograms reflecting the sound pressure distribution and the interference phase distribution are obtained by numerical reconstruction and phase subtraction, which are consistent with the theoretical results. It indicates that the proposed digital holographic interferometory with phase multiplication can successfully double the fringe number of the interference phase patterns of the ALF and improve the measurement precision. Compared with the conventional optical holographic interferometory, digital holographic interferometory has the merits of quasi real-time, more exactitude and convenient operation, and it provides an effective way for studying the sound pressure distribution of the ALF.

  19. Digital demodulator

    NASA Technical Reports Server (NTRS)

    Shull, T. A. (Inventor)

    1982-01-01

    A digital demodulator for converting pulse code modulated data from phase shift key (PSK) to non return to zero (NRZ) and to biphase data is described. The demodulator is composed of standard integrated logic circuits. The key to the demodulation function is a pair of cross coupled one shot multivibrators and which with a flip-flop produce the NRZ-L is all that is required, the circuitry is greatly simplified and the 2(v) times bit rate contraint can be removed from the carrier. A flip-flop, an OR gate, and AND gate and a binary counter generate the bit rate clock (BTCK) for the NRZ-L. The remainder of the circuitry is for converting the NRZ-L and BTCK into biphase data. The device was designed for use in the space shuttle bay environment measurements.

  20. Digital Avionics

    NASA Technical Reports Server (NTRS)

    Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

    2002-01-01

    The field of digital avionics experienced another year of important advances in civil aviation, military systems, and space applications. As a result of the events of 9/11/2001, NASA has pursued activities to apply its aerospace technologies toward improved aviation security. Both NASA Glenn Research Center and Langley Research Center have performed flight research demonstrations using advanced datalink concepts to transmit live pictures from inside a jetliner, and to downlink the contents of the plane's 'black box' recorder in real time. The U.S. Navy and General Electric demonstrated survivable engine control (SEC) algorithms during engine ground tests at the Weapons Survivability Laboratory at China Lake. The scientists at Boeing Satellite Systems advanced the field of stellar inertial technology with the development of a new method for positioning optical star trackers on satellites.

  1. Digital Avionics

    NASA Technical Reports Server (NTRS)

    Koelbl, Terry G.; Ponchak, Denise; Lamarche, Teresa

    2003-01-01

    Digital Avionics activities played an important role in the advancements made in civil aviation, military systems, and space applications. This document profiles advances made in each of these areas by the aerospace industry, NASA centers, and the U.S. military. Emerging communication technologies covered in this document include Internet connectivity onboard aircraft, wireless broadband communication for aircraft, and a mobile router for aircraft to communicate in multiple communication networks over the course of a flight. Military technologies covered in this document include avionics for unmanned combat air vehicles and microsatellites, and head-up displays. Other technologies covered in this document include an electronic flight bag for the Boeing 777, and surveillance systems for managing airport operations.

  2. Digital structural

    USGS Publications Warehouse

    Dohm, J.M.; Anderson, R.C.; Tanaka, K.L.

    1998-01-01

    Magmatic and tectonic activity have both contributed significantly to the surface geology of Mars. Digital structural mapping techniques have now been used to classify and date centers of tectonic activity in the western equatorial region. For example, our results show a center of tectonic activity at Valles Marineris, which may be associated with uplift caused by intrusion. Such evidence may help explain, in part, the development of the large troughs and associated outflow channels and chaotic terrain. We also find a local centre of tectonic activity near the source region of Warrego Valles. Here, we suggest that the valley system may have resulted largely from intrusive-related hydrothermal activity. We hope that this work, together with the current Mars Global Surveyor mission, will lead to a better understanding of the geological processes that shaped the Martian surface.

  3. Single-digit arithmetic processing—anatomical evidence from statistical voxel-based lesion analysis

    PubMed Central

    Mihulowicz, Urszula; Willmes, Klaus; Karnath, Hans-Otto; Klein, Elise

    2014-01-01

    Different specific mechanisms have been suggested for solving single-digit arithmetic operations. However, the neural correlates underlying basic arithmetic (multiplication, addition, subtraction) are still under debate. In the present study, we systematically assessed single-digit arithmetic in a group of acute stroke patients (n = 45) with circumscribed left- or right-hemispheric brain lesions. Lesion sites significantly related to impaired performance were found only in the left-hemisphere damaged (LHD) group. Deficits in multiplication and addition were related to subcortical/white matter brain regions differing from those for subtraction tasks, corroborating the notion of distinct processing pathways for different arithmetic tasks. Additionally, our results further point to the importance of investigating fiber pathways in numerical cognition. PMID:24847238

  4. DNA Subtraction of In Vivo Selected Phage Repertoires for Efficient Peptide Pathology Biomarker Identification in Neuroinflammation Multiple Sclerosis Model

    PubMed Central

    Vargas-Sanchez, Karina; Vekris, Antonios; Petry, Klaus G.

    2016-01-01

    To streamline in vivo biomarker discovery, we developed a suppression subtractive DNA hybridization technique adapted for phage-displayed combinatorial libraries of 12 amino acid peptides (PhiSSH). Physical DNA subtraction is performed in a one-tube-all-reactions format by sequential addition of reagents, producing the enrichment of specific clones of one repertoire. High-complexity phage repertoires produced by in vivo selections in the multiple sclerosis rat model (experimental autoimmune encephalomyelitis, EAE) and matched healthy control rats were used to evaluate the technique. The healthy repertoire served as a physical DNA subtractor from the EAE repertoire to produce the subtraction repertoire. Full next-generation sequencing (NGS) of the three repertoires was performed to evaluate the efficiency of the subtraction technique. More than 96% of the clones common to the EAE and healthy repertoires were absent from the subtraction repertoire, increasing the probability of randomly selecting various specific peptides for EAE pathology to about 70%. Histopathology experiments were performed to confirm the quality of the subtraction repertoire clones, producing distinct labeling of the blood–brain barrier (BBB) affected by inflammation among healthy nervous tissue or the preferential binding to IL1-challenged vs. resting human BBB model. Combining PhiSSH with NGS will be useful for controlled in vivo screening of small peptide combinatorial libraries to discover biomarkers of specific molecular alterations interspersed within healthy tissues. PMID:26917946

  5. A system for digital reconstruction of gypsum dental casts.

    PubMed

    Goshtasby, A A; Nambala, S; deRijk, W G; Campbell, S D

    1997-10-01

    A range scanner is developed that can scan a gypsum dental cast and reconstruct the cast digitally for display and storage purposes. The scanner is based on subtractive light and computes the range values using optical triangulation. A fiducial marker is introduced that, when attached to a dental cast at the time of image acquisition, makes it possible to integrate multiview range images of the cast without image registration. A method for calibrating the scanner is described and experimental results showing the accuracy of the scanner are presented. PMID:9368122

  6. Digital tomosynthesis: technique modifications and clinical applications for neurovascular anatomy

    SciTech Connect

    Maravilla, K.R.; Murry, R.C. Jr.; Diehl, J.; Suss, R.; Allen, L.; Chang, K.; Crawford, J.; McCoy, R.

    1984-09-01

    Digital tomosynthesis studies (DTS) using a linear tomographic motion can provide good quality clinical images when combined with subtraction angiotomography. By modifying their hardware system and the computer software algorithms, the authors were able to reconstruct tomosynthesis images using an isocentric rotation (IR) motion. Applying a combination of linear tomographic and IR techniques in clinical cases, they performed DTS studies in six patients, five with aneurysms and one with a hypervascular tumor. The results showed detailed definitions of the pathologic entities and the regional neurovascular anatomy. Based on this early experience, DTS would seem to be a useful technique for the preoperative surgical planning of vascular abnormalities.

  7. Digital communication systems

    NASA Astrophysics Data System (ADS)

    Peebles, Peyton Z., Jr.

    The fundamental principles of digital communication and the design of practical digital communication systems are explored in an introductory textbook for senior and graduate students of electrical engineering. Chapters are devoted to sampling principles, baseband digital waveforms, baseband digital systems, bandpass binary digital systems, and M-ary digital systems. Deterministic signals, networks, and random-signal theory are reviewed in extensive appendices, and graphs, flow charts, diagrams, and problems are provided.

  8. Intravenous Sedation for Dental Patients with Intellectual Disability

    ERIC Educational Resources Information Center

    Miyawaki, T.; Kohjitani, A.; Maeda, S.; Egusa, M.; Mori, T.; Higuchi, H.; Kita, F.; Shimada, M.

    2004-01-01

    The poor quality of oral health care for people with intellectual disability (ID) has been recognized, and the strong fears about dental treatment suggested as a major reason for disturbances of visits to dentists by such patients. Intravenous sedation is a useful method for relieving the anxiety and fear of such patients about dental treatment,…

  9. Intravenous Cocaine Priming Reinstates Cocaine-Induced Conditioned Place Preference

    ERIC Educational Resources Information Center

    Lombas, Andres S.; Freeman, Kevin B.; Roma, Peter G.; Riley, Anthony L.

    2007-01-01

    Separate groups of rats underwent an unbiased conditioned place preference (CPP) procedure involving alternate pairings of distinct environments with intravenous (IV) injections of cocaine (0.75 mg/kg) or saline immediately or 15 min after injection. A subsequent extinction phase consisted of exposure to both conditioning environments preceded by…

  10. Purple glove syndrome: a dreadful complication of intravenous phenytoin administration

    PubMed Central

    Lalla, Rakesh; Malhotra, Hardeep Singh; Garg, Ravindra Kumar; Sahu, Ritesh

    2012-01-01

    Purple glove syndrome is an uncommon but dreaded complication of intravenous phenytoin administration characterised by pain, oedema and purple-blue discolouration of the limb distal to the site of injection. We describe a 37-year-old gentleman having the characteristic purple glove appearance after phenytoin loading, and discuss the salient features of this syndrome highlighting the pathophysiological and preventive aspects. PMID:22922927

  11. Intravenous Therapy Instruction for Licensed Practical Nurses. Instructor's Guide.

    ERIC Educational Resources Information Center

    Springer, Pam; Carey, Jean

    This Idaho instructor's guide lists tasks and enabling objectives, outlines instruction, and provides handout masters, overhead masters, and tests for intravenous therapy (IV) instruction for licensed practical nurses. Following an introduction and a list of criteria for successful completion of IV therapy courses, the document lists tasks and…

  12. Solute-Filled Syringe For Formulating Intravenous Solution

    NASA Technical Reports Server (NTRS)

    Owens, Jim; Bindokas, AL; Dudar, Tom; Finley, Mike; Scharf, Mike

    1993-01-01

    Prefilled syringe contains premeasured amount of solute in powder or concentrate form used to deliver solute to sterile interior of large-volume parenteral (LVP) bag. Predetermined amount of sterile water also added to LVP bag through sterilizing filter, and mixed with contents of syringe, yielding sterile intravenous solution of specified concentration.

  13. Candida costochondritis associated with recent intravenous drug use

    PubMed Central

    Crawford, Simeon J.; Swan, Christopher D.; Boutlis, Craig S.; Reid, Alistair B.

    2016-01-01

    Candida osteoarticular infections are being reported with increasing frequency, possibly due to an expanding population at risk. However, Candida costochondritis is uncommon. We report two cases of Candida costochondritis in patients who presented with subacute-onset chest wall swelling and whose only identifiable risk factor was a history of recent intravenous drug use. PMID:27182491

  14. Stability of Ceftiofur Sodium and Cefquinome Sulphate in Intravenous Solutions

    PubMed Central

    Jelińska, Anna; Bębenek, Marcelina

    2014-01-01

    Stability of ceftiofur sodium and cefquinome sulphate in intravenous solutions was studied. Chromatographic separation and quantitative determination were performed by using a high-performance liquid chromatography with UV-DAD detection. During the stability study, poly(vinylchloride) minibags were filled with a solution containing 5 mg of ceftiofur sodium or cefquinome sulphate and diluted to 0.2 mg/mL with suitable intravenous solution depending on the test conditions. The solutions for the study were protected from light and stored at room temperature (22°C), refrigerated (6°C), frozen (−20°C) for 30 days, and then thawed at room temperature. A comparison of results obtained at 22°C and 6°C for the same intravenous solutions showed that temperature as well as components of solutions and their concentration had an influence on the stability of ceftiofur sodium and cefquinome sulphate. It was found that ceftiofur sodium and cefquinome sulphate dissolved in intravenous solutions used in this study may be stored at room temperature and at 6°C for up to 48 h. PMID:25025091

  15. In-Use Contamination of Intravenous Infusion Fluid

    PubMed Central

    Maki, Dennis G.; Anderson, Roger L.; Shulman, Jonas A.

    1974-01-01

    During the 1970 to 1971 nationwide epidemic of septicemias caused by Enterobacter cloacae and Enterobacter agglomerans traced to intrinsic contamination of Abbott intravenous infusion products, 94 infusion systems manufactured by Baxter Laboratories were studied microbiologically and epidemiologically during hospital use. Intravenous fluid from 10 systems (11%) contained microorganisms, usually Staphylococcus or Bacillus species; one infusion was heavily contaminated with Klebsiella pneumoniae. No national epidemic organisms, E. cloacae or E. agglomerans (formerly Erwinia), were recovered, suggesting that during this period frequent contamination with these organisms was unique to Abbott's infusion products. Contamination in this study appeared to be extrinsic in origin (introduced during clinical use) and related to the duration of continuous intravenous therapy. Nine of 61 systems (15%) that had been used longer than 48 h were contaminated, whereas only 1 of 33 used less than 48 h (3%) contained microorganisms. This study and the recent national outbreak indicate that contamination of infusion fluid, both from intrinsic and extrinsic sources, must be recognized as an additional risk of intravenous therapy; however, a once-daily replacement of the delivery apparatus can significantly diminish this hazard. PMID:4613269

  16. Saccharomyces cerevisiae boulardii transient fungemia after intravenous self-inoculation.

    PubMed

    Cohen, Lola; Ranque, Stéphane; Raoult, Didier

    2013-02-14

    We report the case of a young psychotic intravenous drug user injecting herself with Saccharomyces cervisiae (boulardii). She experienced a 24 h fever, resolving spontaneously confirming, quasi experimentally, the inocuity of this yeast in a non-immunocompromised host. PMID:24432219

  17. Candida costochondritis associated with recent intravenous drug use.

    PubMed

    Crawford, Simeon J; Swan, Christopher D; Boutlis, Craig S; Reid, Alistair B

    2016-01-01

    Candida osteoarticular infections are being reported with increasing frequency, possibly due to an expanding population at risk. However, Candida costochondritis is uncommon. We report two cases of Candida costochondritis in patients who presented with subacute-onset chest wall swelling and whose only identifiable risk factor was a history of recent intravenous drug use. PMID:27182491

  18. [Hypocomplementemic urticarial vasculitis syndrome. Successful therapy with intravenous immunoglobulins].

    PubMed

    Staubach-Renz, P; von Stebut, E; Bräuninger, W; Maurer, M; Steinbrink, K

    2007-08-01

    Autoimmune diseases can initially present as chronic urticaria. We describe the course of a patient with hypocomplementemic urticarial vasculitis syndrome (HUVS) as well as his successful treatment with high-dose intravenous immunoglobulins (IVIG). HUVS was diagnosed clinically and confirmed by histology and laboratory studies. After only one cycle with IVIG (2 g/kg) all HUVS symptoms were significantly decreased. PMID:17453168

  19. Can We Teach Digital Natives Digital Literacy?

    ERIC Educational Resources Information Center

    Ng, Wan

    2012-01-01

    In recent years, there has been much debate about the concept of digital natives, in particular the differences between the digital natives' knowledge and adoption of digital technologies in informal versus formal educational contexts. This paper investigates the knowledge about educational technologies of a group of undergraduate students…

  20. CAMAC interface for digitally recording infrared camera images

    NASA Astrophysics Data System (ADS)

    Dyer, G. R.

    1986-06-01

    An instrument has been built to store the digital signals from a modified imaging infrared scanner directly in a digital memory. This procedure avoids the signal-to-noise degradation and dynamic range limitations associated with successive analog-to-digital and digital-to-analog conversions and the analog recording method normally used to store data from the scanner. This technique also allows digital data processing methods to be applied directly to recorded data and permits processing and image reconstruction to be done using either a mainframe or a microcomputer. If a suitable computer and CAMAC-based data collection system are already available, digital storage of up to 12 scanner images can be implemented for less than 1750 in materials cost. Each image is stored as a frame of 60×80 eight-bit pixels, with an acquisition rate of one frame every 16.7 ms. The number of frames stored is limited only by the available memory. Initially, data processing for this equipment was done on a VAX 11-780, but images may also be displayed on the screen of a microcomputer. Software for setting the displayed gray scale, generating contour plots and false-color displays, and subtracting one image from another (e.g., background suppression) has been developed for IBM-compatible personal computers.