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Sample records for vitro aorta phantom

  1. PIV and MRV Measurements in Human Thoracic Aorta Phantoms

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    Iyengar, Ananth; Elkins, Christopher; Draney, Mary; Medina, Francisco; Wicker, Ryan

    2004-11-01

    Aortic dissection is a non-traumatic injury to the aorta in which a flap is created inside the aorta by the separation of the inner lining of the vessel wall from its outer layers. It is hypothesized that dissections start as tears in vessels' inner lining and propagate as blood impinges through the tear into the separated part of the vessel wall. No two dissections are alike, but many share common characteristics, one of which is that tear sites occur in similar places in the aorta. In an effort to understand the origins of these tear sites and the propagation of dissections, we are studying blood flow in human aortas. To begin, we are using rigid aorta phantoms based on anatomies of healthy adults extracted from computed tomography (CT) and magnetic resonance imaging (MRI) medical scans. Clear polyurethane phantoms are created by casting around water-soluble positive molds manufactured using rapid prototyping. We study steady flows with Reynolds numbers comparable to those present in the aorta during the systolic pulse and physiologically pulsatile flows. The entire three-dimensional flow is measured using magnetic resonance velocimetry (MRV), a technique based on MRI principles capable of measuring three-component mean velocities. MRV results are compared to the instantaneous and average two-component velocity fields measured in a few 2D planes with particle image velocimetry (PIV). The PIV results provide validation for the MRV and insight into the instantaneous flow structures that may possibly lead to aortic dissection through fluid structure wall interaction.

  2. Pulse-wave propagation in straight-geometry vessels for stiffness estimation: theory, simulations, phantoms and in vitro findings.

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    Shahmirzadi, Danial; Li, Ronny X; Konofagou, Elisa E

    2012-11-01

    Pulse wave imaging (PWI) is an ultrasound-based method for noninvasive characterization of arterial stiffness based on pulse wave propagation. Reliable numerical models of pulse wave propagation in normal and pathological aortas could serve as powerful tools for local pulse wave analysis and a guideline for PWI measurements in vivo. The objectives of this paper are to (1) apply a fluid-structure interaction (FSI) simulation of a straight-geometry aorta to confirm the Moens-Korteweg relationship between the pulse wave velocity (PWV) and the wall modulus, and (2) validate the simulation findings against phantom and in vitro results. PWI depicted and tracked the pulse wave propagation along the abdominal wall of canine aorta in vitro in sequential Radio-Frequency (RF) ultrasound frames and estimates the PWV in the imaged wall. The same system was also used to image multiple polyacrylamide phantoms, mimicking the canine measurements as well as modeling softer and stiffer walls. Finally, the model parameters from the canine and phantom studies were used to perform 3D two-way coupled FSI simulations of pulse wave propagation and estimate the PWV. The simulation results were found to correlate well with the corresponding Moens-Korteweg equation. A high linear correlation was also established between PWV² and E measurements using the combined simulation and experimental findings (R² =  0.98) confirming the relationship established by the aforementioned equation.

  3. Rapid prototyping compliant arterial phantoms for in-vitro studies and device testing

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    Biglino Giovanni

    2013-01-01

    Full Text Available Abstract Background Compliant vascular phantoms are desirable for in-vitro patient-specific experiments and device testing. TangoPlus FullCure 930® is a commercially available rubber-like material that can be used for PolyJet rapid prototyping. This work aims to gather preliminary data on the distensibility of this material, in order to assess the feasibility of its use in the context of experimental cardiovascular modelling. Methods The descending aorta anatomy of a volunteer was modelled in 3D from cardiovascular magnetic resonance (CMR images and rapid prototyped using TangoPlus. The model was printed with a range of increasing wall thicknesses (0.6, 0.7, 0.8, 1.0 and 1.5 mm, keeping the lumen of the vessel constant. Models were also printed in both vertical and horizontal orientations, thus resulting in a total of ten specimens. Compliance tests were performed by monitoring pressure variations while gradually increasing and decreasing internal volume. Knowledge of distensibility was thus derived and then implemented with CMR data to test two applications. Firstly, a patient-specific compliant model of hypoplastic aorta suitable for connection in a mock circulatory loop for in-vitro tests was manufactured. Secondly, the right ventricular outflow tract (RVOT of a patient necessitating pulmonary valve replacement was printed in order to physically test device insertion and assess patient’s suitability for percutaneous pulmonary valve intervention. Results The distensibility of the material was identified in a range from 6.5 × 10-3 mmHg-1 for the 0.6 mm case, to 3.0 × 10-3 mmHg-1 for the 1.5 mm case. The models printed in the vertical orientation were always more compliant than their horizontal counterpart. Rapid prototyping of a compliant hypoplastic aorta and of a RVOT anatomical model were both feasible. Device insertion in the RVOT model was successful. Conclusion Values of distensibility, compared with literature data, show that Tango

  4. Fluid dynamics of coarctation of the aorta: analytical solution, in vitro validation and in vivo evaluation

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    Keshavarz-Motamed, Zahra

    2015-11-01

    Coarctation of the aorta (COA) is a congenital heart disease corresponding to a narrowing in the aorta. Cardiac catheterization is considered to be the reference standard for definitive evaluation of COA severity, based on the peak-to-peak trans-coarctation pressure gradient (PtoP TCPG) and instantaneous systolic value of trans-COA pressure gradient (TCPG). However, invasive cardiac catheterization may carry high risks given that undergoing multiple follow-up cardiac catheterizations in patients with COA is common. The objective of this study is to present an analytical description of the COA that estimates PtoP TCPG and TCPG without a need for high risk invasive data collection. Coupled Navier-Stokes and elastic deformation equations were solved analytically to estimate TCPG and PtoP TCPG. The results were validated against data measured in vitro (e.g., 90% COA: TCPG: root mean squared error (RMSE) = 3.93 mmHg; PtoP TCPG: RMSE = 7.9 mmHg). Moreover, the estimated PtoP TCPG resulted from the suggested analytical description was validated using clinical data in twenty patients with COA (maximum RMSE: 8.3 mmHg). Very good correlation and concordance were found between TCPG and PtoP TCPG obtained from the analytical formulation and in vitro and in vivo data. The suggested methodology can be considered as an alternative to cardiac catheterization and can help preventing its risks.

  5. Gadobenate dimeglumine (MultiHance) in MR angiography: an in-vitro phantom comparison with gadopentetate dimeglumine (Magnevist) at different concentrations.

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    Johansson, Lars; Kirchin, Miles A; Ahlström, Håkan

    2012-12-01

    Numerous clinical studies suggest that gadobenate dimeglumine is diagnostically superior to other gadolinium chelates for MR imaging applications, including contrast-enhanced MR angiography (CE-MRA). However, confirmatory in-vitro phantom studies have thus far been lacking. To evaluate the difference in signal intensity achieved with the high-relaxivity MR contrast agent gadobenate dimeglumine (MultiHance) relative to that achieved with the standard-relaxivity non-specific agent gadopentetate dimeglumine (Magnevist) at different concentrations using an in-vitro phantom study design. Test tubes with whole human blood were prepared with concentrations of gadobenate dimeglumine or gadopentetate dimeglumine ranging from 0 to 12 mM. A three-dimensional (3D) T1-weighted gradient echo sequence normally used for CE-MRA of the renal arteries was performed at flip angles of 25° and 35°. The signal-to-noise ratio (SNR) was calculated for all concentrations of both contrast agents. Furthermore a Look-Locker sequence was used and quantitative T1 mapping was performed for all the test tubes. The contrast agent concentration in the aorta was simulated using previously published data on T1 in the aorta during the first pass of a contrast agent. The differences between gadobenate dimeglumine and gadopentetate dimeglumine were compared at the simulated concentrations. The SNR achieved with gadobenate dimeglumine was consistently greater than that achieved with gadopentetate dimeglumine at all concentrations. An improvement of 15-25% in SNR was obtained when increasing the flip angle from 25° to 35°. The relative improvement in SNR with gadobenate dimeglumine relative to gadopentetate dimeglumine ranged from 25-72% and was markedly greater at lower concentrations with a flip angle of 35°. Our findings suggest that the relative benefit of gadobenate dimeglumine over gadopentetate dimeglumine for CE-MRA applications is greater at lower concentrations.

  6. Comparison of in vitro flows past a mechanical heart valve in anatomical and axisymmetric aorta models

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    Haya, Laura; Tavoularis, Stavros

    2017-06-01

    Flow characteristics past a bileaflet mechanical heart valve were measured under physiological flow conditions in a straight tube with an axisymmetric expansion, similar to vessels used in previous studies, and in an anatomical model of the aorta. We found that anatomical features, including the three-lobed sinus and the aorta's curvature affected significantly the flow characteristics. The turbulent and viscous stresses were presented and discussed as indicators for potential blood damage and thrombosis. Both types of stresses, averaged over the two axial measurement planes, were significantly lower in the anatomical model than in the axisymmetric one. This difference was attributed to the lower height-to-width ratio and more gradual contraction of the anatomical aortic sinus. The curvature of the aorta caused asymmetries in the velocity and stress distributions during forward flow. Secondary flows resulting from the aorta's curvature are thought to have redistributed the fluid stresses transversely, resulting in a more homogeneous stress distribution in the anatomical aortic root than in the axisymmetric root. The results of this study demonstrate the importance of modelling accurately the aortic geometry in experimental and computational studies of prosthetic devices. Moreover, our findings suggest that grafts used for aortic root replacement should approximate as closely as possible the shape of the natural sinuses.

  7. Matrix production of smooth muscle cells from rat aorta in vitro.

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    Stiemer, B; Springmeier, G; el-Jarad, L; Schröter-Kermani, C

    1993-01-01

    Immunofluorescence microscopic methods served to demonstrate the production of the following matrix components in cultures of vascular smooth muscle cells from rat aorta: fibronectin; nidogen; heparan sulphate-proteoglycan (HS-PG); laminin; and collagen types I, III, IV, V, and VI. A time-dependence of synthesis and secretion could be shown for a number of components of the extracellular matrix (ECM), such as laminin. The results revealed the following estimated quantitative differences of the collagen types: type I > type III > types V and VI. A filamentous/fibrillar matrix and also occasionally a typical basal lamina could be demonstrated electron microscopically around the smooth muscle cells.

  8. Novel tissue-engineered vascular patches based on decellularized canine aortas and their recellularization in vitro

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    Tu, Qiufen; Zhang, Yi; Ge, Dongxia; Wu, Jiang; Chen, Huaiqing

    2008-11-01

    Decellularized allo- or xenogeneic vascular grafts have been found to give more promising results than some biodegradable synthetic polymers. However, owing to absence of well-organized cells, especially confluent endothelial cells, their long-term patency is limited. Seeding vessel-originated cells on these grafts may overcome the deficiency. In this study, canine aortas were decellularized and cross-linked. 4',6-Diamidino-2-phenylindole (DAPI) and Masson' trichrome staining showed complete removal of cell debris, while structure integrity of extracellular matrix (ECM) was remained. Human umbilical vein endothelial cells (HUVECs) and human umbilical artery smooth muscle cells (HUASMCs) were seeded on these decellularized aorta patches in three manners, ECs alone (EC/O), SMCs alone (SMC/O) and ECs on SMCs layer (EC/SMC). In EC/O and SMC/O, scanning electron microscopy (SEM) examination indicated both cells could form confluent layers on the decellularized patches when seeded at high density, but their morphology and alignment changed with seeding density. In EC/SMC, ECs could grow well on SMCs layer, but their morphology, alignment, and confluence degree were deeply influenced by the density of SMCs beneath.

  9. In vitro vasorelaxation mechanisms of bioactive compounds extracted from Hibiscus sabdariffa on rat thoracic aorta

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    Gueye Lamine

    2009-11-01

    Full Text Available Abstract Background In this study, we suggested characterizing the vasodilator effects and the phytochemical characteristics of a plant with food usage also used in traditional treatment of arterial high blood pressure in Senegal. Methods Vascular effects of crude extract of dried and powdered calyces of Hibiscus sabdariffa were evaluated on isolated thoracic aorta of male Wistar rats on organ chambers. The crude extract was also enriched by liquid-liquid extraction. The various cyclohexane, dichloromethane, ethyl acetate, butanol extracts obtained as well as the residual marc were subjected to Sephadex LH-20 column chromatography. The different methanolic eluate fractions were then analyzed by Thin Layer (TLC and High Performance Liquid Chromatography (HPLC and their vascular effects also evaluated. Results The H. Sabdariffa crude extract induced mainly endothelium-dependent relaxant effects. The endothelium-dependent relaxations result from NOS activation and those who not dependent to endothelium from activation of smooth muscle potassium channels. The phytochemical analysis revealed the presence of phenolic acids in the ethyl acetate extract and anthocyans in the butanolic extract. The biological efficiency of the various studied extracts, in term of vasorelaxant capacity, showed that: Butanol extract > Crude extract > Residual marc > Ethyl acetate extract. These results suggest that the strong activity of the butanolic extract is essentially due to the presence of anthocyans found in its fractions 43-67. Conclusion These results demonstrate the vasodilator potential of hibiscus sabdariffa and contribute to his valuation as therapeutic alternative.

  10. In vitro vasorelaxation mechanisms of bioactive compounds extracted from Hibiscus sabdariffa on rat thoracic aorta

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    Sarr, Mamadou; Ngom, Saliou; Kane, Modou O; Wele, Alassane; Diop, Doudou; Sarr, Bocar; Gueye, Lamine; Andriantsitohaina, Ramaroson; Diallo, Aminata S

    2009-01-01

    Background In this study, we suggested characterizing the vasodilator effects and the phytochemical characteristics of a plant with food usage also used in traditional treatment of arterial high blood pressure in Senegal. Methods Vascular effects of crude extract of dried and powdered calyces of Hibiscus sabdariffa were evaluated on isolated thoracic aorta of male Wistar rats on organ chambers. The crude extract was also enriched by liquid-liquid extraction. The various cyclohexane, dichloromethane, ethyl acetate, butanol extracts obtained as well as the residual marc were subjected to Sephadex LH-20 column chromatography. The different methanolic eluate fractions were then analyzed by Thin Layer (TLC) and High Performance Liquid Chromatography (HPLC) and their vascular effects also evaluated. Results The H. Sabdariffa crude extract induced mainly endothelium-dependent relaxant effects. The endothelium-dependent relaxations result from NOS activation and those who not dependent to endothelium from activation of smooth muscle potassium channels. The phytochemical analysis revealed the presence of phenolic acids in the ethyl acetate extract and anthocyans in the butanolic extract. The biological efficiency of the various studied extracts, in term of vasorelaxant capacity, showed that: Butanol extract > Crude extract > Residual marc > Ethyl acetate extract. These results suggest that the strong activity of the butanolic extract is essentially due to the presence of anthocyans found in its fractions 43-67. Conclusion These results demonstrate the vasodilator potential of hibiscus sabdariffa and contribute to his valuation as therapeutic alternative. PMID:19883513

  11. Rice Germosprout Extract Protects Erythrocytes from Hemolysis and the Aorta, Brain, Heart, and Liver Tissues from Oxidative Stress In Vitro

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    Shahdat Hossain

    2016-01-01

    Full Text Available Identifying dietary alternatives for artificial antioxidants capable of boosting antihemolytic and antioxidative defense has been an important endeavor in improving human health. In the present study, we studied antihemolytic and antioxidative effects of germosprout (i.e., the germ part along with sprouted stems plus roots extract prepared from the pregerminated rice. The extract contained considerable amounts of antioxidant β-carotene (414±12 ng/g of extract and phytochemicals such as total polyphenols (12.0±1.1 mg gallic acid equivalent/g of extract and flavonoids (11.0±1.4 mg catechin equivalent/g of extract. The antioxidant potential of the extract was assessed by its DPPH- (2,2-diphenyl-1-picrylhydrazyl- free radical scavenging activity where we observed that germosprout extract had considerable antioxidative potentials. To evaluate antihemolytic effect of the extract, freshly prepared erythrocytes were incubated with either peroxynitrite or Fenton’s reagent in the absence or presence of the extract. We observed that erythrocytes pretreated with the extract exhibited reduced degree of in vitro hemolysis. To support the proposition that germosprout extract could act as a good antioxidative agent, we also induced in vitro oxidative stress in erythrocyte membranes and in the aorta, brain, heart, and liver tissue homogenates in the presence of the extract. As expected, germosprout extract decreased oxidative stress almost to the same extent as that of vitamin E, as measured by lipid peroxide levels, in all the mentioned tissues. We conclude that rice germosprout extract could be a good natural source of antioxidants to reduce oxidative stress-induced hemolysis and damage of blood vessels and other tissues.

  12. Sesquiterpene lactones from Hedyosmum brasiliense induce in vitro relaxation of rat aorta and corpus cavernosum

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    Amanda Leitolis

    Full Text Available Abstract Hedyosmum brasiliense Miq., Chloranthaceae, has been used in Southern Brazil as a sedative, anti-inflammatory, and aphrodisiac. In this study, endothelium-intact and endothelium-denuded rat aortic rings and strips of corpus cavernosum were used to investigate the relaxant effects of an hexane fraction of leaves of H. brasiliense and its sesquiterpene lactones 13-hydroxy-8,9-dehydroshizukanolide, podoandin, and elemanolide 15-acetoxy-isogermafurenolide. The incubation of hexane fraction of leaves of H. brasiliense resulted in significant relaxation of endothelium-intact aortic rings previously contracted by phenylephrine. In addition, 13-hydroxy-8,9-dehydroshizukanolide and podoandin displayed a clear concentration-dependent ability to relax endothelium-intact (∼85 to 90% and endothelium-denuded (∼45 to 55% rat aortic rings. A less pronounced vascular relaxation was recorded when 15-hydroxy-isogermafurenolide was tested. Interestingly, in tissues previously incubated with the nitric oxide synthase inhibitor L-NAME (100 µM, both 13-hydroxy-8,9-dehydroshizukanolide and podoandin had their effects in endothelium-intact vessels reduced to the same degree of relaxation observed in endothelium-denuded aortic rings. Podoandin, 13-hydroxy-8,9-dehydroshizukanolide, and 15-acetoxy-isogermafurenolide (100 µM were also able to relax precontracted corpus cavernosum strips by 49.5 ± 3.9%, 65.9 ± 7.3% and 57.9 ± 5.5%, respectively. Our results demonstrated that 13-hydroxy-8,9-dehydroshizukanolide, podoandin and 15-acetoxy-isogermafurenolide, isolated from H. brasiliense, generate both endothelium-dependent and -independent relaxation of rat aortic rings, as well as being able to induce in vitro relaxation of rat corpus cavernosum. Importantly, the endothelium-dependent effect is fully dependent on nitric oxide production. Considering that penile erection depends on both relaxation of cavernosal smooth muscle and inflow of blood for the

  13. Evaluation of factors influencing arterial Doppler waveforms in an in vitro flow phantom

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    Sung, Chang Kyu [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Kyoung Ho [Dept. of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Kim, Seung Hyup [Dept. of Radiology and the Institute of Radiation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2017-01-15

    The aim of this study was to investigate factors that influence arterial Doppler waveforms in an in vitro phantom to provide a more accurate and comprehensive explanation of the Doppler signal. A flow model was created using a pulsatile artificial heart, rubber or polyethylene tubes, a water tank, and a glass tube. Spectral Doppler tracings were obtained in multiple combinations of compliance, resistance, and pulse rate. Peak systolic velocity, minimum diastolic velocity, resistive index (RI), pulsatility index, early systolic acceleration time, and acceleration index were measured. On the basis of these measurements, the influences of the variables on the Doppler waveforms were analyzed. With increasing distal resistance, the RI increased in a relatively linear relationship. With increasing proximal resistance, the RI decreased. The pulsus tardus and parvus phenomenon was observed with a small acceleration index in the model with a higher grade of stenosis. An increase in the distal resistance masked the pulsus tardus and parvus phenomenon by increasing the acceleration index. Although this phenomenon occurred independently of compliance, changes in the compliance of proximal or distal tubes caused significant changes in the Doppler waveform. There was a reverse relationship between the RI and the pulse rate. Resistance and compliance can alter the Doppler waveforms independently. The pulse rate is an extrinsic factor that also influences the RI. The compliance and distal resistance, as well as proximal resistance, influence the pulsus tardus and parvus phenomenon.

  14. Optimal Scanning Protocols for Dual-Energy CT Angiography in Peripheral Arterial Stents: An in Vitro Phantom Study

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    Abdulrahman Almutairi

    2015-05-01

    Full Text Available Objective: To identify the optimal dual-energy computed tomography (DECT scanning protocol for peripheral arterial stents while achieving a low radiation dose, while still maintaining diagnostic image quality, as determined by an in vitro phantom study. Methods: Dual-energy scans in monochromatic spectral imaging mode were performed on a peripheral arterial phantom with use of three gemstone spectral imaging (GSI protocols, three pitch values, and four kiloelectron volts (keV ranges. A total of 15 stents of different sizes, materials, and designs were deployed in the phantom. Image noise, the signal-to-noise ratio (SNR, different levels of adaptive statistical iterative reconstruction (ASIR, and the four levels of monochromatic energy for DECT imaging of peripheral arterial stents were measured and compared to determine the optimal protocols. Results: A total of 36 scans with 180 datasets were reconstructed from a combination of different protocols. There was a significant reduction of image noise with a higher SNR from monochromatic energy images between 65 and 70 keV in all investigated preset GSI protocols (p < 0.05. In addition, significant effects were found from the main effect analysis for these factors: GSI, pitch, and keV (p = 0.001. In contrast, there was significant interaction on the unstented area between GSI and ASIR (p = 0.015 and a very high significant difference between keV and ASIR (p < 0.001. A radiation dose reduction of 50% was achieved. Conclusions: The optimal scanning protocol and energy level in the phantom study were GSI-48, pitch value 0.984, and 65 keV, which resulted in lower image noise and a lower radiation dose, but with acceptable diagnostic images.

  15. Methanol fractionations of Catha edulis Frosk (Celastraceae) contracted Lewis rat aorta in vitro: a comparison between crimson and green leaves.

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    Mahmood, Samira Abdulla; Pavlovic, Dragan; Hoffmann, Ulrich

    2009-05-07

    The study investigated the effect of methanol extract and its fractionations obtained from Yemeni khat on the smooth muscle isometric tension in Lewis rat aortal ring preparations and compared the effects of the crimson and green leaves. Khat leaves were sorted into green (khat Light; KL) and crimson (khat Dark; KD) leaves, extracted with methanol, followed with solvent-solvent extraction (benzene, chloroform and ethylacetate). The contractile activity of the fractions was tested using aortal ring preparations. The control (phenylepherine contraction) methanol extracts contracted aortas at concentrations 250, 125 and 67.5 microg/ml buffer by 80.2%, 57.3%, 26.4% and 81.5%, 65.6%, 24.6% for KL and KD, respectively. Fractions of benzene (BF) and ethylacetate (EaF) contracted the aorta with 2 microgm, whereas, chloroform (ChF) with 1 microgm/1 ml buffer was less potent. The shape of contraction curve produced by EaF differed from that of ChF and BF of both (KL and KD). The EaF induced-contraction peaked after 3.3 +/- 0.94 mins, whereas those of BF and CHF peaked after 18.0 +/- 2.2, 19.7 +/- 0.94 mins, respectively. Pre-incubation with nifedipine (10(-6) M) insignificantly reduced the contraction induced by all fractionations, but prazosin (10(-6) M) reduced the contraction by 81.9%, 63.1%, 71.8% with p = 0.23, 0.09, 0.15 for BF, ChF and EaF of KL, respectively. It significantly reduced contraction of ChF, 64.1%; p = 0.02, and of EaF, 73.5%; p = 0.04 of KD, while the reduction in contraction of BF was 63.1%; p = 0.06. In conclusion, fractions of green and crimson Yemeni khat leaves contracted aortas of Lewis rats. Both leaves behave almost similarly. Contraction induced by chloroform fraction produced alpha-sympathetic activity.

  16. Effects of clinico-pathological risk factors on in-vitro mechanical properties of human dilated ascending aorta.

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    Ferrara, Anna; Totaro, Pasquale; Morganti, Simone; Auricchio, Ferdinando

    2018-01-01

    Ascending aorta aneurysms (AsAA) are associated with a degeneration of the aortic wall tissue, which leads to changes in tissue mechanical properties. Risk factors for the development of the AsAA disease are recognized in patient age and gender, valve type, hypertension, diabetes mellitus, smoking history, and a prior diagnosis of Marfan syndrome. The present study aims to assess how such clinico-pathological factors can affect the mechanical properties of human dilated ascending aorta. Specimens of AsAA are excised from 68 patients who underwent elective AsAA surgical repair and stretched until rupture during the execution of uniaxial tensile tests. Experimental stress-stretch curves are used to determine tissue mechanical properties (stress and stretch at failure point and at transition point, low and high elastic modulus). Data are divided into groups according to region (anterior vs posterior), direction (circumferential vs longitudinal), and then according to age (young vs old), gender (male vs female), valve type (tricuspid aortic valve, TAV, vs bicuspid aortic valve, BAV), and presence of hypertension, diabetes mellitus, and/or Marfan syndrome (yes/no). Moreover, data are grouped according to the critical value of body mass index (BMI), maximum AsAA diameter, and aortic stiffness index (ASI), respectively. Finally, a non-parametric statistical analysis is performed to find possible significant differences and correlations between mechanical properties and clinico-pathological data. Our results confirm the anisotropy and heterogeneity of the AsAA tissue and highlight that ageing and hypertension make the AsAA tissue weaker and less extensible, whereas the valve type affects the tissue strength with higher values in BAV than in TAV patients. No effects of gender, critical BMI, critical maximum AsAA diameter, critical ASI, smoking status, and presence of diabetes mellitus, and Marfan syndrome are evidenced. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Fabrication of a compliant phantom of the human aortic arch for use in Particle Image Velocimetry (PIV experimentation

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    Hütter Larissa

    2016-09-01

    Full Text Available Compliant phantoms of the human aortic arch can mimic patient specific cardiovascular dysfunctions in vitro. Hence, phantoms may enable elucidation of haemodynamic disturbances caused by aortic dysfunction. This paper describes the fabrication of a thin-walled silicone phantom of the human ascending aorta and brachiocephalic artery. The model geometry was determined via a meta-analysis and modelled in SolidWorks before 3D printing. The solid model surface was smoothed and scanned with a 3D scanner. An offset outer mould was milled from Ebalta S-Model board. The final phantom indicated that ABS was a suitable material for the internal model, the Ebalta S-Model board yielded a rough external surface. Co-location of the moulds during silicone pour was insufficient to enable consistent wall thickness. The resulting phantom was free of air bubbles but did not have the desired wall thickness consistency.

  18. Axial transmission method for long bone fracture evaluation by ultrasonic guided waves: simulation, phantom and in vitro experiments.

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    Xu, Kailiang; Ta, Dean; He, Runxin; Qin, Yi-Xian; Wang, Weiqi

    2014-04-01

    Mode conversion occurs when the ultrasonic guided waves encounter fractures. The aim of this study was to investigate the feasibility of fracture assessment in long cortical bone using guided-mode conversion. Mode conversion behavior between the fundamental modes S0 and A0 was analyzed. The expressions proposed for modal velocity were used to identify the original and converted modes. Simulations and phantom experiments were performed using 1.0-mm-thick steel plates with a notch width of 0.5 mm and notch depths of 0.2, 0.4, 0.6 and 0.8 mm. Furthermore, in vitro experiments were carried out on nine ovine tibias with 1.0-mm-wide partial transverse gap break and cortical thickness varying from 2.10 to 3.88 mm. The study confirmed that mode conversion gradually becomes observable as fracture depth increases. Energy percentages of the converted modes correlated strongly with fracture depth, as illustrated by the frequency-sweeping experiments on steel phantoms (100-1100 kHz, r(2) = 0.97, p < 0.0069) and the fixed-frequency experiments on nine ovine tibias (250 kHz, r(2) = 0.97, p < 0.0056). The approaches described, including mode excitation, velocity expressions and energy percentage criteria, may also contribute to ultrasonic monitoring of long bone fracture healing. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. In vitro vasodilatory activity and possible mechanisms of the crude extracts and fractions of Moringa stenopetala (Baker f.) Cufod. leaves in isolated thoracic aorta of guinea pigs.

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    Geleta, Bekesho; Makonnen, Eyasu; Debella, Asfaw; Abebe, Abiy; Fekadu, Netsanet

    2016-01-01

    Moringa stenopetala, a plant belonging to the family of Moringaceae, is traditionally used for the treatment of hypertension and diabetes in Ethiopia. This study evaluates the in vitro vasodilatory effect of the extract of M. stenopetala leaves and the possible mechanisms in precontracted isolated thoracic aorta of guinea pigs. A guinea pig was sacrificed by gentle cervical dislocation, and the thoracic aortic ring was removed, cut spirally, and mounted in an organ bath containing Krebs-Henseleit physiological solution maintained at 37°C, and then the solution was aerated with carbogen (95% O2 and 5% CO2). The vasodilatory activity of cumulative doses of M. stenopetala extracts and fractions was evaluated on intact and denuded endothelium of isolated whole, spirally cut thoracic aortic strips of guinea pigs precontracted with potassium chloride (80 mM), epinephrine (1 μM), methylene blue (10 μM), and glibenclamide (10 μM) using polygraph. All extracts showed a relaxant effect in precontracted isolated whole, spirally cut thoracic aortic strips of guinea pigs in a dose-dependent manner, whereas the greater percentage of relaxant effect was shown with the addition of crude extracts in 80 mM of potassium chloride (99.10% and 95.56% for ethanol and aqueous crude extracts, respectively), and 1 μM of epinephrine (82.85% and 90.16% for ethanol and aqueous crude extracts, respectively) in precontracted isolated whole, spirally cut thoracic aortic strips of guinea pigs. Hence, the possible mechanism of relaxation might be mediated through the blockade of receptor-operated calcium influx and L-type voltage-dependent calcium channels. The aqueous extract showed more significant in vitro vasodilatory effect than its fractions and 70% ethanol extract.

  20. Aorta and liver changes in rats fed cholesterol-containing and raw vegetable-supplemented diets: experiments in vitro and in vivo.

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    Gorinstein, Shela; Leontowicz, Hanna; Leontowicz, Maria; Najman, Katarzyna; Bielecki, Wojciech; Ham, Kyung-Sik; Kang, Seong-Gook; Paredes-Lopez, Octavio; Martinez-Ayala, Alma Leticia; Trakhtenberg, Simon

    2011-07-13

    The aim of this investigation was to compare the liver and aorta changes in rats fed cholesterol-containing diets and the possible improvement when diets would be supplemented with frequently used raw vegetables. The phenolic compounds of three vegetables in methanol-water (1:1) fraction were characterized using electrospray ionization mass spectra (ESI-MS). Results showed that the content of polyphenols, flavonoids, quercetin, flavanols, tannins, and ascorbic acid varied for garlic and white and red onions ranging from 6.68 to 18.08 mg GAE/g DW, 490.4-701.0 μg CE/g DW, 281.2-1100.0 μg, 32.40-41.30 μg CE/g DW, 2.88-3.12 mg CE/g DW, 1.87-2.33 mg AA/g DW, 1388.2-1442.3 μg CGE/g DW, respectively. The radical scavenging capacities (μM TE/g DW) for the same investigated vegetables for ABTS, FRAP, CUPRAC, and DPPH assays ranged from 48.78 to 92.42, 9.41-28.56, 3.06-10.41, and 6.49-23.42, respectively. Good correlations were observed between the phenolic contents and the radical scavenging capacities of the vegetables. The interaction between BSA and quercetin, BSA and garlic and onions extracts was measured by 3-dimensional fluorescence (3D-FL) and Fourier transform infrared (FT-IR) spectroscopy. The highest polyphenol content was found in methanol/water fraction of onions and garlic; therefore, for the investigation of in vitro interactions with BSA only polyphenols of this fraction were used. For in vivo studies, 30 male Wistar rats were divided into 5 groups each of 6 and named Control, Chol, Chol/Garlic, Chol/OnionRed, and Chol/OnionWhite. During 6 weeks, the rats of all 5 groups were fed a basal diet (BD). The rats of the Control group were fed the BD only. The BD of the Chol group was supplemented with 10 g/kg of nonoxidized cholesterol (NOC). Each of the other three groups was supplemented with 10 g/kg of NOC and 500 mg of raw fresh garlic, 500 mg of raw fresh red onion, and 500 mg of raw fresh white onion on 1 kg of body weight for Chol/Garlic, Chol

  1. Human Aorta Is a Passive Pump

    Science.gov (United States)

    Pahlevan, Niema; Gharib, Morteza

    2012-11-01

    Impedance pump is a simple valveless pumping mechanism that operates based on the principles of wave propagation and reflection. It has been shown in a zebrafish that a similar mechanism is responsible for the pumping action in the embryonic heart during early stages before valve formation. Recent studies suggest that the cardiovascular system is designed to take advantage of wave propagation and reflection phenomena in the arterial network. Our aim in this study was to examine if the human aorta is a passive pump working like an impedance pump. A hydraulic model with different compliant models of artificial aorta was used for series of in-vitro experiments. The hydraulic model includes a piston pump that generates the waves. Our result indicates that wave propagation and reflection can create pumping mechanism in a compliant aorta. Similar to an impedance pump, the net flow and the flow direction depends on the frequency of the waves, compliance of the aorta, and the piston stroke.

  2. [Curriculum vitae aortae].

    Science.gov (United States)

    Solberg, S

    1998-12-10

    The Greek word aorta means lifter. The vessel was so termed because Aristotle, who first described it, assumed that the heart was lifted by/hanging in aorta. Leonardo da Vinci described the detailed anatomy of aorta. During the 17th century our present understanding of the aorta and the circulation of blood took form due to the descriptions given by William Harvey. The first known operation for abdominal aortic aneurysm was performed in London in 1817 by Sir Astley Cooper who ligated the infrarenal aorta above the aneurysm. Puncture with needles and application of electricity were later tried in order to induce thromboses in the aneurysm. In 1948 Albert Einstein was operated with wrapping of his abdominal aneurysm with cellophane. In 1955 he suffered rupture and died after having refused operation. In 1951 the first successful operation for abdominal aortic aneurysm was performed in Paris by Charles Dubost. With slight modifications, the same operative technique is used today.

  3. Micro-organismos efectivos (EM-X: acción in-vivo sobre aorta de conejos hipercolesterolémicos Effective microorganisms (EM-X: in-vitro action on aorta of hypercholesterolemic rabbits

    Directory of Open Access Journals (Sweden)

    Darío Echeverri

    Full Text Available Antecedentes y objetivos: EM-X es una bebida antioxidante derivada del salvado de arroz y extractos de algas marinas fermentadas con micro-organismos efectivos. El objetivo de este estudio fue determinar si el EM-X previene la formación de placa aterosclerótica y favorece la relajación vascular in-vitro en un modelo de aterosclerosis temprana en conejos hipercolesterolémicos. Métodos: la población se dividió en cuatro grupos: 1: conejos ateroscleróticos con administración de EM-X; 2: conejos ateroscleróticos sin administración de EM-X; 3: conejos sanos sin administración de EM-X; y 4: conejos sanos con administración de EM-X. A cada conejo se le midió el colesterol sérico y se le extrajeron anillos aórticos para análisis in-vitro de la relajación vascular dependiente e independiente de endotelio. Se realizaron análisis histomorfométricos y cuantificación de la endotelización arterial. Resultados: la cifra de colesterol total fue mayor en los grupos 1 vs. 2 y 3 vs. 4 (p>0,05. La RDE inducida por acetilcolina, mostró disfunción en los grupos con hipercolesterolemia y aterosclerosis. No se observaron diferencias entre los grupos 1 y 2 (p = 0,181, ni entre los grupos 3 y 4 (p= 0,349. Las características histomorfométricas no presentaron diferencias entre los grupos 1 y 2 ( p = 0,85 ni entre los grupos 3 y 4 (p = 0,95. El análisis de inmunohistoquímica no mostró diferencias significativas entre los cuatro grupos (p = 0,85. Conclusión: los resultados encontrados no demuestran beneficio del EM-X como terapia antioxidante en la prevención de placa aterosclerótica y en la relajación vascular dependiente de endotelio in-vitro en animales sanos o enfermos con disfunción endotelial y aterosclerosis.Background: EM-X is an antioxidant beverage obtained from rice bran and seaweed extracts fermented with Effective Microorganisms. The purpose of this study was to determine if EM-X prevents atherosclerotic plaque formation and

  4. In-vitro investigation of the hemodynamic responses of the cerebral, coronary and renal circulations with a rotary blood pump installed in the descending aorta.

    Science.gov (United States)

    Rezaienia, M A; Paul, G; Avital, E J; Mozafari, S; Rothman, M; Korakianitis, T

    2017-02-01

    This study investigates the hemodynamic responses of the cardiovascular system when a rotary blood pump is operating in the descending aorta, with a focus on the cerebral, coronary and renal autoregulation, using our in-house cardiovascular emulator. Several improvements have been made from our previous studies. A novel coronary system was developed to replicate the native coronary perfusion. Three pinch valves actuated by stepper motors were used to simulate the regional autoregulation systems of the native cerebral, coronary and renal circulations. A rotary pump was installed in the descending aorta, in series with the heart, and the hemodynamic responses of the cardiovascular system were investigated with a focus on cerebral, coronary and renal circulation over a wide range of pump rotor speeds. Experiments were performed twice, once with the autoregulation systems active and once with the autoregulation systems inactive, to reflect that there will be some impairment of autoregulatory systems in a patient with heart failure. It was shown that by increasing the rotor speed to 3000 rpm, the cardiac output was improved from 2.9 to 4.1 L/min as a result of an afterload reduction induced by the pressure drop upstream of the pump. The magnitudes of changes in perfusion in the cerebral, coronary and renal circulations were recorded with regional autoregulation systems active and inactive. Copyright © 2016. Published by Elsevier Ltd.

  5. Radiation-force-based estimation of acoustic attenuation using harmonic motion imaging (HMI) in phantoms and in vitro livers before and after HIFU ablation.

    Science.gov (United States)

    Chen, Jiangang; Hou, Gary Y; Marquet, Fabrice; Han, Yang; Camarena, Francisco; Konofagou, Elisa

    2015-10-07

    Acoustic attenuation represents the energy loss of the propagating wave through biological tissues and plays a significant role in both therapeutic and diagnostic ultrasound applications. Estimation of acoustic attenuation remains challenging but critical for tissue characterization. In this study, an attenuation estimation approach was developed using the radiation-force-based method of harmonic motion imaging (HMI). 2D tissue displacement maps were acquired by moving the transducer in a raster-scan format. A linear regression model was applied on the logarithm of the HMI displacements at different depths in order to estimate the acoustic attenuation. Commercially available phantoms with known attenuations (n = 5) and in vitro canine livers (n = 3) were tested, as well as HIFU lesions in in vitro canine livers (n = 5). Results demonstrated that attenuations obtained from the phantoms showed a good correlation (R² = 0.976) with the independently obtained values reported by the manufacturer with an estimation error (compared to the values independently measured) varying within the range of 15-35%. The estimated attenuation in the in vitro canine livers was equal to 0.32   ±   0.03 dB cm(-1) MHz(-1), which is in good agreement with the existing literature. The attenuation in HIFU lesions was found to be higher (0.58   ±   0.06 dB cm(-1) MHz(-1)) than that in normal tissues, also in agreement with the results from previous publications. Future potential applications of the proposed method include estimation of attenuation in pathological tissues before and after thermal ablation.

  6. Radiation-force-based estimation of acoustic attenuation using harmonic motion imaging (HMI) in phantoms and in vitro livers before and after HIFU ablation

    Science.gov (United States)

    Chen, Jiangang; Hou, Gary Y.; Marquet, Fabrice; Han, Yang; Camarena, Francisco; Konofagou, Elisa

    2015-10-01

    Acoustic attenuation represents the energy loss of the propagating wave through biological tissues and plays a significant role in both therapeutic and diagnostic ultrasound applications. Estimation of acoustic attenuation remains challenging but critical for tissue characterization. In this study, an attenuation estimation approach was developed using the radiation-force-based method of harmonic motion imaging (HMI). 2D tissue displacement maps were acquired by moving the transducer in a raster-scan format. A linear regression model was applied on the logarithm of the HMI displacements at different depths in order to estimate the acoustic attenuation. Commercially available phantoms with known attenuations (n=5 ) and in vitro canine livers (n=3 ) were tested, as well as HIFU lesions in in vitro canine livers (n=5 ). Results demonstrated that attenuations obtained from the phantoms showed a good correlation ({{R}2}=0.976 ) with the independently obtained values reported by the manufacturer with an estimation error (compared to the values independently measured) varying within the range of 15-35%. The estimated attenuation in the in vitro canine livers was equal to 0.32   ±   0.03 dB cm-1 MHz-1, which is in good agreement with the existing literature. The attenuation in HIFU lesions was found to be higher (0.58   ±   0.06 dB cm-1 MHz-1) than that in normal tissues, also in agreement with the results from previous publications. Future potential applications of the proposed method include estimation of attenuation in pathological tissues before and after thermal ablation.

  7. Human phantom

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    This human phantom has been received by CERN on loan from the State Committee of the USSR for the Utilization of Atomic Energy. It is used by the Health Physics Group to study personel radiation doses near the accelerators.

  8. Phantom Pain

    Science.gov (United States)

    ... 16, 2014. Phantom pain Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  9. Phantom thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Diaz, Pedro F. [Colina de los Chopos, Centro de Fisica ' Miguel A. Catalan' , Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)]. E-mail: p.gonzalezdiaz@imaff.cfmac.csic.es; Sigueenza, Carmen L. [Colina de los Chopos, Centro de Fisica ' Miguel A. Catalan' , Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)

    2004-10-04

    This paper deals with the thermodynamic properties of a phantom field in a flat Friedmann-Robertson-Walker universe. General expressions for the temperature and entropy of a general dark-energy field with equation of state p={omega}{rho} are derived from which we have deduced that, whereas the temperature of a cosmic phantom fluid ({omega}-1) is definite negative, its entropy is always positive. We interpret that result in terms of the intrinsic quantum nature of the phantom field and apply it to (i) attain a consistent explanation for some recent results concerning the evolution of black holes which,induced by accreting phantom energy, gradually loss their mass to finally vanish exactly at the big rip, and (ii) introduce the concept of cosmological information and its relation with life and the anthropic principle. Some quantum statistical-thermodynamic properties of the quantum field are also considered that include a generalized Wien law and the prediction of some novel phenomena such as the stimulated absorption of phantom energy and the anti-laser effect.

  10. In vitro dual perfusion of human placental lobules as a flow phantom to investigate the relationship between fetoplacental flow and quantitative 3D power doppler angiography.

    Science.gov (United States)

    Jones, N W; Hutchinson, E S; Brownbill, P; Crocker, I P; Eccles, D; Bugg, G J; Raine-Fenning, N J

    2009-02-01

    Flow phantoms have been used to investigate and quantify three-dimensional power Doppler data but this is the first study to use the in vitro, dual perfused, placental perfusion model. We used this model to investigate and quantify the effect of variation in fetal-side flow rates and attenuation on 3D power Doppler angiography. Perfusion of a placental lobule was commenced within 30 min of delivery and experimentation was successful in 8 of the 18 placenta obtained. Fetal and maternal perfusate was modified Earle's bicarbonate buffer which, following equilibration, was supplemented on the fetal side with whole heparinised cord blood. Imaging was performed with a Voluson-i ultrasound machine. A 'vascular biopsy' the thickness of the placental lobule was defined and signal quantified within using VOCAL (GE Medical Systems, Zipf, Austria). Three vascular indices are generated: vascularisation index (VI) defined as the percentage of power Doppler data within a volume of interest; flow index (FI), the mean signal intensity of the power Doppler information; and vascularisation flow index (VFI), a combination of both factors derived through their multiplication. Attenuation was investigated in this model with the addition of tissue mimic blocks. Our results showed a predictable relationship between flow rates and the vascular indices VI and VFI. However the FI was a less reliable predictor of flow; thus it should be interpreted with caution. The power Doppler signal was markedly affected by attenuation leading to a complete loss of information at a depth of 6 cm in the model used. In conclusion this model can be adapted to provide a phantom to analyse and quantify 3D power Doppler signals and demonstrates that vascular indices within a tissue remain related to volume flow. This model provides further evidence that depth dependent attenuation of signal needs to be accounted for in any in vivo work where the probe is not in direct contact with the tissue of interest.

  11. The response of MRI contrast parameters in in vitro tissues and tissue mimicking phantoms to fractionation by histotripsy

    Science.gov (United States)

    Allen, Steven P.; Vlaisavljevich, Eli; Shi, Jiaqi; Hernandez-Garcia, Luis; Cain, Charles A.; Xu, Zhen; Hall, Timothy L.

    2017-09-01

    Histotripsy is a non-invasive, focused ultrasound lesioning technique that can ablate precise volumes of soft tissue using a novel mechanical fractionation mechanism. Previous research suggests that magnetic resonance imaging (MRI) may be a sensitive image-based feedback mechanism for histotripsy. However, there are insufficient data to form some unified understanding of the response of the MR contrast mechanisms in tissues to histotripsy. In this paper, we investigate the response of the MR contrast parameters R1, R2, and the apparent diffusion coefficient (ADC) to various treatment levels of histotripsy in in vitro porcine liver, kidney, muscle, and blood clot as well in formulations of bovine red blood cells suspended in agar gel. We also make a histological analysis of histotripsy lesions in porcine liver. We find that R2 and the ADC are both sensitive to ablation in all materials tested here, and the degree of response varies with tissue type. Correspondingly, under histologic analysis, the porcine liver exhibited various levels of mechanical disruption and necrotic debris that are characteristic of histotripsy. While the area of intact red blood cells and nuclei found within these lesions both decreased with increasing amounts of treatment, the area of red blood cells decreased much more rapidly than the area of intact nuclei. Additionally, the decrease in area of intact red blood cells saturated at the same treatment levels at which the response of the R2 saturated while the area of intact nuclei appeared to vary linearly with the response of the ADC.

  12. On the potential of a new IVUS elasticity modulus imaging approach for detecting vulnerable atherosclerotic coronary plaques: in vitro vessel phantom study.

    Science.gov (United States)

    Le Floc'h, Simon; Cloutier, Guy; Finet, Gérard; Tracqui, Philippe; Pettigrew, Roderic I; Ohayon, Jacques

    2010-10-07

    Peak cap stress amplitude is recognized as a good indicator of vulnerable plaque (VP) rupture. However, such stress evaluation strongly relies on a precise, but still lacking, knowledge of the mechanical properties exhibited by the plaque components. As a first response to this limitation, our group recently developed, in a previous theoretical study, an original approach, called iMOD (imaging modulography), which reconstructs elasticity maps (or modulograms) of atheroma plaques from the estimation of strain fields. In the present in vitro experimental study, conducted on polyvinyl alcohol cryogel arterial phantoms, we investigate the benefit of coupling the iMOD procedure with the acquisition of intravascular ultrasound (IVUS) measurements for detection of VP. Our results show that the combined iMOD-IVUS strategy: (1) successfully detected and quantified soft inclusion contours with high positive predictive and sensitivity values of 89.7 ± 3.9% and 81.5 ± 8.8%, respectively, (2) estimated reasonably cap thicknesses larger than ∼300 µm, but underestimated thinner caps, and (3) quantified satisfactorily Young's modulus of hard medium (mean value of 109.7 ± 23.7 kPa instead of 145.4 ± 31.8 kPa), but overestimated the stiffness of soft inclusions (mean Young`s moduli of 31.4 ± 9.7 kPa instead of 17.6 ± 3.4 kPa). All together, these results demonstrate a promising benefit of the new iMOD-IVUS clinical imaging method for in vivo VP detection.

  13. On the potential of a new IVUS elasticity modulus imaging approach for detecting vulnerable atherosclerotic coronary plaques: in vitro vessel phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Floc' h, Simon Le; Tracqui, Philippe; Ohayon, Jacques [Laboratory TIMC-DynaCell, UJF, CNRS UMR 5525, In3S, Grenoble (France); Cloutier, Guy [Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Montreal, Quebec (Canada); Finet, Gerard [Department of Hemodynamics and Interventional Cardiology, Hospices Civils de Lyon and Claude Bernard University Lyon 1, INSERM Unit 886, Lyon (France); Pettigrew, Roderic I, E-mail: Guy.Cloutier@umontreal.c, E-mail: Jacques.Ohayon@imag.f [Laboratory of Integrative Cardiovascular Imaging Science, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (United States)

    2010-10-07

    Peak cap stress amplitude is recognized as a good indicator of vulnerable plaque (VP) rupture. However, such stress evaluation strongly relies on a precise, but still lacking, knowledge of the mechanical properties exhibited by the plaque components. As a first response to this limitation, our group recently developed, in a previous theoretical study, an original approach, called iMOD (imaging modulography), which reconstructs elasticity maps (or modulograms) of atheroma plaques from the estimation of strain fields. In the present in vitro experimental study, conducted on polyvinyl alcohol cryogel arterial phantoms, we investigate the benefit of coupling the iMOD procedure with the acquisition of intravascular ultrasound (IVUS) measurements for detection of VP. Our results show that the combined iMOD-IVUS strategy: (1) successfully detected and quantified soft inclusion contours with high positive predictive and sensitivity values of 89.7 {+-} 3.9% and 81.5 {+-} 8.8%, respectively, (2) estimated reasonably cap thicknesses larger than {approx}300 {mu}m, but underestimated thinner caps, and (3) quantified satisfactorily Young's modulus of hard medium (mean value of 109.7 {+-} 23.7 kPa instead of 145.4 {+-} 31.8 kPa), but overestimated the stiffness of soft inclusions (mean Young's moduli of 31.4 {+-} 9.7 kPa instead of 17.6 {+-} 3.4 kPa). All together, these results demonstrate a promising benefit of the new iMOD-IVUS clinical imaging method for in vivo VP detection.

  14. In vitro validation and comparison of different software packages or algorithms for coronary bifurcation analysis using calibrated phantoms: implications for clinical practice and research of bifurcation stenting.

    Science.gov (United States)

    Ishibashi, Yuki; Grundeken, Maik J; Nakatani, Shimpei; Iqbal, Javaid; Morel, Marie-Angele; Généreux, Philippe; Girasis, Chrysafios; Wentzel, Jolanda J; Garcia-Garcia, Hector M; Onuma, Yoshinobu; Serruys, Patrick W

    2015-03-01

    The accuracy and precision of quantitative coronary angiography (QCA) software dedicated for bifurcation lesions compared with conventional single-vessel analysis remains unknown. Furthermore, comparison of different bifurcation analysis algorithms has not been performed. Six plexiglas phantoms with 18 bifurcations were manufactured with a tolerance Analysis System (CAAS; Version 5.10, Pie Medical Imaging, Maastricht, The Netherlands) and QAngio XA (Version 7.3, Medis Medical Imaging System BV, Leiden, The Netherlands) software packages. Conventional single-vessel analysis underestimated the reference vessel diameter and percent diameter stenosis in the proximal main vessel while it overestimated these parameters in the distal main vessel and side branch. CAAS software showed better overall accuracy and precision than QAngio XA (with automatic Y- or T-shape bifurcation algorithm selection) for various phantom diameters including minimum lumen diameter (0.012 ± 0.103 mm vs. 0.041 ± 0.322 mm, P = 0.003), reference vessel diameter (-0.050 ± 0.043 mm vs. 0.116 ± 0.610 mm, P = 0.026), and % diameter stenosis (-0.94 ± 4.07 % vs. 1.74 ± 7.49 %, P = 0.041). QAngio XA demonstrated higher minimal lumen diameter, reference vessel diameter, and % diameter stenosis when compared to the actual phantom diameters; however, the accuracy of these parameters improved to a similar level as CAAS when the sole T-shape algorithm in the QAnxio XA was used. The use of the single-vessel QCA method is inaccurate in bifurcation lesions. Both CAAS and QAngio XA (when the T shape is systematically used) bifurcation software packages are suitable for quantitative assessment of bifurcations. © 2014 Wiley Periodicals, Inc.

  15. Image based cardiac acceleration map using statistical shape and 3D+t myocardial tracking models; in-vitro study on heart phantom

    Science.gov (United States)

    Pashaei, Ali; Piella, Gemma; Planes, Xavier; Duchateau, Nicolas; de Caralt, Teresa M.; Sitges, Marta; Frangi, Alejandro F.

    2013-03-01

    It has been demonstrated that the acceleration signal has potential to monitor heart function and adaptively optimize Cardiac Resynchronization Therapy (CRT) systems. In this paper, we propose a non-invasive method for computing myocardial acceleration from 3D echocardiographic sequences. Displacement of the myocardium was estimated using a two-step approach: (1) 3D automatic segmentation of the myocardium at end-diastole using 3D Active Shape Models (ASM); (2) propagation of this segmentation along the sequence using non-rigid 3D+t image registration (temporal di eomorphic free-form-deformation, TDFFD). Acceleration was obtained locally at each point of the myocardium from local displacement. The framework has been tested on images from a realistic physical heart phantom (DHP-01, Shelley Medical Imaging Technologies, London, ON, CA) in which the displacement of some control regions was known. Good correlation has been demonstrated between the estimated displacement function from the algorithms and the phantom setup. Due to the limited temporal resolution, the acceleration signals are sparse and highly noisy. The study suggests a non-invasive technique to measure the cardiac acceleration that may be used to improve the monitoring of cardiac mechanics and optimization of CRT.

  16. An In Vitro Study of a New Device: Evaluation of Novel Wide-Angle Lens Flexible Cystoscope Using Phantom Bladder Model.

    Science.gov (United States)

    Yamaguchi, Kunihisa; Inoue, Takamitsu; Habuchi, Tomonori; Inokuchi, Junichi; Yokomizo, Akira; Eto, Masatoshi; Kanayama, Hiro-Omi

    2017-10-01

    The features and usefulness of a novel wide-angle lens flexible cystoscope were assessed with a view to its practical application. A phantom bladder model, on which a total of 12 markers that resemble lesions were arranged, was created for this study. Twenty-six urologists at three institutions observed this phantom bladder model using a conventional flexible cystoscope and a novel wide-angle lens flexible cystoscope, and they compared the observation time, marker detection rate, number of misidentified marker locations, overlooked locations, and misidentified location sites of both devices. Specific observation procedures that make use of the features of a wide-angle lens flexible cystoscope were also investigated. The observation time tended to be shorter with the wide-angle lens cystoscope than with a conventional cystoscope (104.9 seconds vs 113.6 seconds, p = 0.123). The marker detection rate was higher with the wide-angle lens cystoscope (90.2% vs 85.1%, p = 0.005). The number of marker location misidentifications did not differ between the two devices. Using a specifically designed observation procedure with the wide-angle lens cystoscope tended to further improve the marker detection rate (91.4% vs 88.1%, p = 0.157). Compared with a conventional cystoscope, a wide-angle lens cystoscope improved the lesion detection rate and has the potential to reduce observation time. The novel wide-angle lens flexible cystoscope is regarded as a useful device that offers advantages not available with a conventional cystoscope.

  17. Inositol uptake in rat aorta

    Energy Technology Data Exchange (ETDEWEB)

    Rapoport, R.M.; Van Gorp, C.; Chang, Ki-Churl (Univ. of Cincinnati College of Medicine, OH (USA))

    1990-01-01

    {sup 3}H-inositol uptake into deendothelialized aorta was linear for at least 2 h and was composed of both a saturable, Na{sup +}-dependent, and a nonsaturable, Na{sup +}-independent component. The Na{sup +}-dependent component of inositol uptake had a K{sub m} of 50 {mu}M and a V{sub max} of 289 pmol/mg prot/h. Exposure to LiCl, ouabain, or Ca{sup 2+} - free Krebs-Ringer bicarbonate solution inhibited uptake. Metabolic poisoning with dinitrophenol, as well as incubation with phloretin, an inhibitor of carrier-mediated hexose transport, also inhibited uptake. Exposure to norepinephrine decreased inositol uptake, while phorbol myristate acetate was without effect. Isobutylmethylxanthine significantly increased inositol uptake, while the increased uptake due to dibutyryl cyclic AMP and forskolin were not statistically significant. Sodium nitroprusside, and activator of guanylate cyclase, and 8-bromo cyclic GMP, were without effect on uptake, as was methylene blue, an inhibitor of guanylate cyclase. Inositol uptake into the aorta was increased when the endothelium was allowed to remain intact, although this effect was likely due to uptake in both the endothelial and smooth muscle cells.

  18. 21. Phantom pain.

    NARCIS (Netherlands)

    Wolff, A.P.; Vanduynhoven, E.; Kleef, M. van; Huygen, F.; Pope, J.E.; Mekhail, N.

    2011-01-01

    Phantom pain is pain caused by elimination or interruption of sensory nerve impulses by destroying or injuring the sensory nerve fibers after amputation or deafferentation. The reported incidence of phantom limb pain after trauma, injury or peripheral vascular diseases is 60% to 80%. Over half the

  19. Realistic computerized human phantoms

    Science.gov (United States)

    Zankl, M.; Veit, R.; Petoussi, N.; Mannweiler, E.; Wittmann, A.; Drexler, G.

    1994-10-01

    To estimate the risk resulting from exposures to ionizing radiation, the organ and tissue doses should be assessed. A convenient method is the calculation of these doses using representations of the human body, called models or phantoms, together with computer codes simulating the transport of radiation in the body. Most commonly used are mathematical phantoms whose external and internal volumes are defined by simple geometric bodies. More recently, phantoms constructed from computed tomographic data of real persons were introduced as an improvement. These phantoms present advantages concerning the location and shape of the organs, in particular the hard bone and bone marrow, whose distribution can be assessed with high resolution. So far, three of these phantoms were constructed at the GSF, a fourth is under process. The construction technique is described, and some calculational results of organ doses due to external photon irradiation are presented.

  20. Acute spontaneous isolated dissection of abdominal aorta

    Directory of Open Access Journals (Sweden)

    Ali Akbar beigi

    2009-09-01

    Full Text Available

    • Aortic dissection occurs when the layers of the aorta separate as a result of extra luminal cavity of blood through an intimal tear. Dissection limited to the abdominal aorta is rare. Unfortunately, the appropriate management of dissecting aneurysm of abdominal aorta is not documented yet. A 43 years old man was admitted to Al-zahra hospital in Isfahan with sudden onset of periumbilical abdominal pain. CT scan confirmed infrarenal dissection of abdominal aorta. Performing laparotomy, aorta was repaired using bifurcate collagen-coated Dacron graft. Surgical intervention with synthetic graft is recommended in patients with dissecting aortic aneurysm of infrarenal segments where the extent of dissection is limited and accessible.
    • Keywords: Aneurysm, Aortic dissection, Aortic aneurysm abdominal surgery.

  1. In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Tetsuya; Matsumura, Akira; Nose, Tadao [Tsukuba Univ., Tsukuba, Ibaraki (Japan); Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Hori, Naohiko; Torii, Yoshiya; Horiguchi, Yoji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-05-01

    The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without {sup 10}B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of {sup 10}B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99{+-}0.24, 3.04{+-}0.19 and 1.43{+-}0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50{+-}0.32, 2.34{+-}0.30 and 2.17{+-}0.28 for ENB, TNB-1 and TNB-2, respectively. The biological effectiveness factor values of the neutron and photon components were 1.22{+-}0.16, 1.23{+-}0.16 and 1.21{+-}0.16, respectively. The depth function of biological effectiveness factor in water phantom and the difference in biological effectiveness factor among boron compounds were also determined. The experimental determination of biological effectiveness factor outlined in this paper is applicable to the dose calculation for each dose component of the neutron beams and contribute to an accurate biological effectiveness factor as comparison with a neutron beam at a different facility employed in ongoing and planned BNCT clinical trials. (author)

  2. Optimization of reduced-dose MDCT of thoracic aorta using iterative reconstruction.

    Science.gov (United States)

    Töre, Hüseyin Gürkan; Entezari, Pegah; Chalian, Hamid; Gonzalez-Guindalini, Fernanda Dias; Botelho, Marcos Paulo Ferreira; Yaghmai, Vahid

    2014-01-01

    To evaluate the contribution of iterative reconstruction on image quality of reduced-dose multidetector computed tomography of the thoracic aorta. A torso phantom was scanned using two tube potentials (80 and 120 kVp) and five different tube currents (110, 75, 40, 20, and 10 mAs). All images were reconstructed with both filtered back projection (FBP) and iterative reconstruction. Aortic attenuation, image noise within the thoracic aorta, signal-to-noise ratio, and sharpness of the aortic wall were quantified in the phantom for the two reconstruction algorithms. Data were analyzed using paired t test. A value of P iterative reconstruction (P > 0.05). Image noise level was lower (P iterative reconstruction. Signal-to-noise ratios were higher with iterative reconstruction compared with those with FBP (P iterative reconstruction (9.8 ± 4.4) was similar to the signal-to-noise ratio at 120 kVp with FBP (8.4 ± 3.3) (P = 0.196). Less image noise and higher image sharpness may be achieved with iterative reconstruction in reduced-dose multidetector computed tomography of the thoracic aorta.

  3. Evaluation of the effect of machine settings on quantitative three-dimensional power Doppler angiography: an in-vitro flow phantom experiment.

    Science.gov (United States)

    Raine-Fenning, N J; Nordin, N M; Ramnarine, K V; Campbell, B K; Clewes, J S; Perkins, A; Johnson, I R

    2008-09-01

    Three-dimensional (3D) ultrasound is being used increasingly to acquire and subsequently quantify power Doppler data within the clinical setting. One proprietary software package calculates three 3D vascular indices: the vascularization index (VI), the flow index (FI), and the vascularization flow index (VFI). Our aim was to evaluate how different settings affect the Doppler signal in terms of its quantification by these three indices within a 3D dataset. A computer-driven 'flow phantom' was used to continuously pump a nylon particle-based blood mimic (Orgasol(trade mark)) around a closed system through a C-flex(trade mark) tube embedded in an agar-based tissue mimic. The test tanks were insonated with a modified 3D transvaginal 4-8-MHz ultrasound transducer (V530D) and power Doppler data were acquired over a series of different settings. Each experiment involved the manipulation of just one Doppler setting in order to study it in isolation. As expected, all of the power Doppler settings, when altered, were found to effect significant changes (P effect, producing no Doppler signals at the lowest settings and the highest recordable indices at the maximum settings. The pulse repetition frequency (PRF) was the next most influential setting but a Doppler signal was seen and measurable at all of the different settings. The other Doppler settings had a much less profound effect on the vascular indices, with subtle but significantly different measures across the full range of settings. The speed of data acquisition was also found to affect the vascular indices, all of which were reduced when the fast mode was used although the only significant effect was on the VFI. The VI, FI and VFI are all affected significantly by variations in power Doppler settings and by the speed of acquisition. The gain and signal power have the greatest effect on the power Doppler signal, followed closely by the PRF. The other settings and speed of acquisition also influence the signal, but to a

  4. 6-Gingerol alleviates exaggerated vasoconstriction in diabetic rat aorta through direct vasodilation and nitric oxide generation.

    Science.gov (United States)

    Ghareib, Salah A; El-Bassossy, Hany M; Elberry, Ahmed A; Azhar, Ahmad; Watson, Malcolm L; Banjar, Zainy Mohammed

    2015-01-01

    The aim of the present study is to investigate the effect and potential mechanism of action of 6-gingerol on alterations of vascular reactivity in the isolated aorta from diabetic rats. Male Wistar rats were divided into two experimental groups, control and diabetics. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg kg(-1)), and the rats were left for 10 weeks to develop vascular complications. The effect of in vitro incubation with 6-gingerol (0.3-3 μM) on the vasoconstrictor response of the isolated diabetic aortae to phenylephrine and the vasodilator response to acetylcholine was examined. Effect of 6-gingerol was also examined on aortae incubated with methylglyoxal as an advanced glycation end product (AGE). To investigate the mechanism of action of 6-gingerol, the nitric oxide synthase inhibitor Nω-nitro-l-arginine methyl ester hydrochloride (100 μM), guanylate cyclase inhibitor methylene blue (5 μM), calcium-activated potassium channel blocker tetraethylammonium chloride (10 mM), and cyclooxygenase inhibitor indomethacin (5 μM) were added 30 minutes before assessing the direct vasorelaxant effect of 6-gingerol. Moreover, in vitro effects of 6-gingerol on NO release and the effect of 6-gingerol on AGE production were examined. Results showed that incubation of aortae with 6-gingerol (0.3-10 μM) alleviated the exaggerated vasoconstriction of diabetic aortae to phenylephrine in a concentration-dependent manner with no significant effect on the impaired relaxatory response to acetylcholine. Similar results were seen in the aortae exposed to methylglyoxal. In addition, 6-gingerol induced a direct vasodilation effect that was significantly inhibited by Nω-nitro-l-arginine methyl ester hydrochloride and methylene blue. Furthermore, 6-gingerol stimulated aortic NO generation but had no effect on AGE formation. In conclusion, 6-gingerol ameliorates enhanced vascular contraction in diabetic aortae, which may be partially

  5. A methodology for developing anisotropic AAA phantoms via additive manufacturing.

    Science.gov (United States)

    Ruiz de Galarreta, Sergio; Antón, Raúl; Cazón, Aitor; Finol, Ender A

    2017-05-24

    An Abdominal Aortic Aneurysm (AAA) is a permanent focal dilatation of the abdominal aorta at least 1.5 times its normal diameter. The criterion of maximum diameter is still used in clinical practice, although numerical studies have demonstrated the importance of biomechanical factors for rupture risk assessment. AAA phantoms could be used for experimental validation of the numerical studies and for pre-intervention testing of endovascular grafts. We have applied multi-material 3D printing technology to manufacture idealized AAA phantoms with anisotropic mechanical behavior. Different composites were fabricated and the phantom specimens were characterized by biaxial tensile tests while using a constitutive model to fit the experimental data. One composite was chosen to manufacture the phantom based on having the same mechanical properties as those reported in the literature for human AAA tissue; the strain energy and anisotropic index were compared to make this choice. The materials for the matrix and fibers of the selected composite are, respectively, the digital materials FLX9940 and FLX9960 developed by Stratasys. The fiber proportion for the composite is equal to 0.15. The differences between the composite behavior and the AAA tissue are small, with a small difference in the strain energy (0.4%) and a maximum difference of 12.4% in the peak Green strain ratio. This work represents a step forward in the application of 3D printing technology for the manufacturing of AAA phantoms with anisotropic mechanical behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. An in vitro phantom study on the influence of tear size and configuration on the hemodynamics of the lumina in chronic type B aortic dissections.

    Science.gov (United States)

    Rudenick, Paula A; Bijnens, Bart H; García-Dorado, David; Evangelista, Arturo

    2013-02-01

    Management and follow-up of chronic aortic dissections continue to be a clinical challenge due to progressive dilatation and subsequent rupture. To predict complications, guidelines suggest follow-up of aortic diameter. However, dilatation is triggered by hemodynamic parameters (pressures/wall shear stresses) and geometry of false (FL) and true lumen (TL), information not captured by diameter alone. Therefore, we aimed at better understanding the influence of dissection anatomy on TL and FL hemodynamics. In vitro studies were performed using pulsatile flow in realistic dissected latex/silicone geometries with varying tear number, size, and location. We assessed three different conformations: (1) proximal tear only; (2) distal tear only; (3) both proximal and distal tears. All possible combinations (n = 8) of small (10% of aortic diameter) and large (25% of aortic diameter) tears were considered. Pressure, velocity, and flow patterns were analyzed within the lumina (at proximal and distal sections) and at the tears. We also computed the FL mean pressure index (FPI(mean)%) as a percentage of the TL mean pressure, to compare pressures among models. The presence of large tears equalized FL/TL pressures compared with models with only small tears (proximal FPI(mean)% 99.85 ± 0.45 vs 92.73 ± 3.63; distal FPI(mean)% 99.51 ± 0.80 vs 96.35 ± 1.96; P 290 cm/s), and a well-defined flow. Additionally, both proximal and distal tears act as entry and exit. During systole, flow enters the FL through all tears simultaneously, while during diastole, flow leaves through all communications. Flow through the FL, from proximal to distal tears or vice versa, is minimal. Our results suggest that FL hemodynamics heavily depends on cumulative tear size, and thus, it is an important parameter to take into account when clinically assessing chronic aortic dissections. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  7. Jamitons: Phantom Traffic Jams

    Science.gov (United States)

    Kowszun, Jorj

    2013-01-01

    Traffic on motorways can slow down for no apparent reason. Sudden changes in speed by one or two drivers can create a chain reaction that causes a traffic jam for the vehicles that are following. This kind of phantom traffic jam is called a "jamiton" and the article discusses some of the ways in which traffic engineers produce…

  8. The Phantom Menace

    DEFF Research Database (Denmark)

    Vium, Christian

    2013-01-01

    as a phantom menace, which asserts itself through a form of omnipresent fear, nurtured by an inherent opaqueness. As this fundamental fear progressively permeates the nomadic landscape, it engenders a recasting of mobile strategies among the nomadic pastoralist groups who inhabit the interstitial desert spaces....

  9. Phantom pain after eye amputation

    DEFF Research Database (Denmark)

    Rasmussen, Marie L R; Prause, Jan U; Toft, Peter B

    2011-01-01

    Purpose: To characterize the quality of phantom pain, its intensity and frequency following eye amputation. Possible triggers and relievers of phantom pain are investigated. Methods: The hospital database was searched using surgery codes for patients who received ocular evisceration, enucleation,...... appears to be similar to the phantom pain suffered by limb amputees. Patients should be informed about this potential complication before surgery....

  10. Pseudoprominent aorta: Radiographic findings and CT correlation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.T.; Shepard, J.A.O.; Stewart, W.J.

    1985-05-01

    The presence of a persistent left-sided superior vena cava (LSVC) in the absence of a right-sided superior vena cava (RSVC) may be suspected on a posteroanterior (PA) chest radiograph because of a prominent-appearing ascending aorta, which results from the absence of the RSVC. In the absence of an RSVC, the right upper lobe abuts and outlines the course of the ascending aorta, allowing better demonstration of its profile. This report describes a patient with this finding on a PA chest radiograph. Computed tomographic correlation is presented.

  11. Tissue-like phantoms

    Science.gov (United States)

    Frangioni, John V.; De Grand, Alec M.

    2007-10-30

    The invention is based, in part, on the discovery that by combining certain components one can generate a tissue-like phantom that mimics any desired tissue, is simple and inexpensive to prepare, and is stable over many weeks or months. In addition, new multi-modal imaging objects (e.g., beads) can be inserted into the phantoms to mimic tissue pathologies, such as cancer, or merely to serve as calibration standards. These objects can be imaged using one, two, or more (e.g., four) different imaging modalities (e.g., x-ray computed tomography (CT), positron emission tomography (PET), single photon emission computed tomography (SPECT), and near-infrared (NIR) fluorescence) simultaneously.

  12. Spiral CT-angiography of the aorta

    NARCIS (Netherlands)

    Balm, R.; Eikelboom, B. C.; van Leeuwen, M. S.; Noordzij, J.

    1994-01-01

    AIMS: To determine whether the new technique of CT-angiography was accurate in displaying the complex anatomy of the aorta and its major branches. METHODS: Seventeen patients with a variety of aortic pathology were examined. Using a spiral CT-scanner a volumetric scan was made during injection of

  13. AORTA: Adding Organizational Reasoning to Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia

    2014-01-01

    the expected behavior of the agents. Agents need to be able to reason about the regulations, so that they can act within the expected boundaries and work towards the objectives of the organization. This extended abstract introduces AORTA, a component that can be integrated into agents’ reasoning mechanism...

  14. Platelet affinity for burro aorta collagen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.D.

    1977-10-01

    Despite ingenious concepts, there are no unequivocal clues as to what, when, and how some undefined biochemical factor(s) or constituent(s) that localizes in the arterial wall can precipitate a thromboatheromatous lesion or arterial disease. The present study focused on the extraction, partial purification, and characterization of a collagen-active platelet stimulator from the aortas of aged burros. The aggregator moiety in the aorta extracts invariably had a higher affinity for platelets in citrated platelet-rich plasma of human beings than for platelets of homologous burros. The platelet-aggregating factor(s) in the aorta extract was retained by incubation with ..cap alpha..-chymotrypsin. Platelet-aggregating activity was rapidly abolished after incubation with collagenase, as determined by platelet-aggregometry tests. Evidence based on light microscope and polysaccharide histochemical reactions indicates a probability that the intracellular amorphous matrix (PAS-positive) and filamentous components (PTAH-positive) expelled from smooth muscle cells disrupted during homogenization of the aorta may be a principal source of a precursor collagen species which is a potent inducer of platelet aggregation.

  15. [Ascending aorta-supraceliac++ aorta bypass. Correction of a case of atypical coarctation in the adult].

    Science.gov (United States)

    Vaquero, F; Zorita, A; Samos, R F; Vázquez, J G; Ortega, J M; Morán, C F

    1993-01-01

    A case of atypic coarctation at the aortic arch in an adult patient is described. Coarctation was surgically treated by a retrosternal bypass from the ascendant aorta to the supra-celiac aorta. After a short prelude the clinical case is summarized. Furthermore, the etiopathogenic features of the disease, the different diagnostic methods and the multiple surgical procedures are discussed. Finally, we briefly review the literature.

  16. Infrarenal abdominal aorta approach through median minilaparotomy.

    Science.gov (United States)

    Pătruţ, G V; Jiga, L P; Tăranu, G P; Rata, A; Neamtu, C; Ionac, M

    2012-01-01

    Classically, infrarenal aortic exposure is achieved by xyphopubic or xypho-infraumbilical laparotomy, in transperitoneal approach, or through a left abdominal incision, in retroperitoneal approach. The transperitoneal approach is associated with longer intestinal activity resumption time and incisional hernias on long term, due to intestinal extracavitary mobilization and long incision. These disadvantages disappear in laparoscopic approach, but this method is extremely laborious, requires an extended period for dissection, and elicits increased difficulty in performing the anastomosis on the aorta. The purpose of the study is to evaluate the infrarenal abdominal aorta approach through median minilaparotomy, a method that combines the excellent exposure of xypho-pubic incision with the low morbidity of laparoscopic approach. Between 07.01.2010 - 07.01.2011, we performed 37 revascularization surgeries in 36 patients with aorto-iliac occlusive disease (one patient required reintervention due to graft thrombosis), approaching the infrarenal aorta through median minilaparotomy. The sex distribution was 35 men and one woman. The average age was 61.1 years. There have been 25 aorto-bifemoral bypasses, 11 aorto-unifemoral bypasses, and one aorto-biiliac bypass. The mean aorta clamping time was 15 minutes. Average operating time was 150 minutes. We used 26 bifurcated Dacron prostheses and 11 linear ePTFEprostheses. The average intestinal activity resumption time was 32 hours. All patients included in the study were mobilized 24 hours after surgery. The average length of hospitalization was 7.7 days. 5 patients experienced complications during hospitalization and 3 patients suffered long term complications. Infrarenal abdominal aorta approach through median minilaparotomy is a viable alternative to conventional surgical techniques used in aortoiliac occlusive disease. Celsius.

  17. MR imaging and MR angiography of the aorta; Magnetresonanztomographie und -angiographie der Aorta

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, G.; Massmann, A.; Altmeyer, K.; Katoh, M.; Buecker, A. [Universitaetsklinikum des Saarlandes,Medizinische Fakultaet der Universitaet des Saarlandes, Klinik fuer Diagnostische und Interventionelle Radiologie, Homburg/Saar (Germany)

    2007-11-15

    When a diseased aorta is to be imaged, the clinical picture and the urgency determine which of the various procedures available is or are used. One of the more recent techniques applied is conventional MR -imaging, and especially contrast-enhanced MR angiography (CE-MRA), which is a noninvasive technique and allows for the combination of conventional imaging, acquisition of physiological parameters and 3D-angiography. In this article technical and clinical aspects of the use of CE-MRA in different diseases affecting the aorta are discussed. Topics covered include congenital malformations of the aorta, acquired disease, and inflammatory conditions. (orig.) [German] Bei der Bildgebung von Erkrankungen der Aorta koennen heute je nach Krankheitsbild und Dringlichkeit unterschiedliche Verfahren zur Anwendung kommen. Neuere Verfahren stellen die konventionelle MR-Tomographie und speziell die kontrastverstaerkte MR-Angiographie dar, die nichtinvasiv die Kombination von Anatomie, Akquisition physiologischer Parameter und 3D-Angiographie kombiniert. In diesem Artikel werden sowohl technische als auch klinische Aspekte bei der Anwendung der MR-Tomographie bei Erkrankungen der Aorta diskutiert. Inhaltlich werden sowohl angeborene Fehlbildungen, erworbene Erkrankungen wie auch entzuendliche Veraenderungen der Aorta dargestellt. (orig.)

  18. Indigo carmine enhances phenylephrine-induced contractions in an isolated rat aorta

    OpenAIRE

    Choi, Yun Suk; Ok, Seong-Ho; Lee, Seung Min; Park, Sang-Seung; Ha, Yu Mi; Chang, Ki Churl; Kim, Hye Jung; Shin, Il-Woo; Sohn, Ju-Tae

    2011-01-01

    Background The intravenous administration of indigo carmine has been reported to produce transiently increased blood pressure in patients. The goal of this in vitro study was to examine the effect of indigo carmine on phenylephrine-induced contractions in an isolated rat aorta and to determine the associated cellular mechanism with particular focus on the endothelium-derived vasodilators. Methods The concentration-response curves for phenylephrine were generated in the presence or absence of ...

  19. Phantom breast syndrome

    Directory of Open Access Journals (Sweden)

    Ramesh

    2009-01-01

    Full Text Available Phantom breast syndrome is a type of condition in which patients have a sensation of residual breast tissue and can include both non-painful sensations as well as phantom breast pain. The incidence varies in different studies, ranging from approximately 30% to as high as 80% of patients after mastectomy. It seriously affects quality of life through the combined impact of physical disability and emotional distress. The breast cancer incidence rate in India as well as Western countries has risen in recent years while survival rates have improved; this has effectively increased the number of women for whom post-treatment quality of life is important. In this context, chronic pain following treatment for breast cancer surgery is a significantly under-recognized and under-treated problem. Various types of chronic neuropathic pain may arise following breast cancer surgery due to surgical trauma. The cause of these syndromes is damage to various nerves during surgery. There are a number of assumed factors causing or perpetuating persistent neuropathic pain after breast cancer surgery. Most well-established risk factors for developing phantom breast pain and other related neuropathic pain syndromes are severe acute postoperative pain and greater postoperative use of analgesics. Based upon current evidence, the goals of prophylactic strategies could first target optimal peri-operative pain control and minimizing damage to nerves during surgery. There is some evidence that chronic pain and sensory abnormalities do decrease over time. The main group of oral medications studied includes anti-depressants, anticonvulsants, opioids, N-methyl-D-asparate receptor antagonists, mexilitine, topical lidocaine, cannabinoids, topical capsaicin and glysine antagonists. Neuromodulation techniques such as motor cortex stimulation, spinal cord stimulation, and intrathecal drug therapies have been used to treat various neuropathic pain syndromes.

  20. The Phantom of Liberty

    DEFF Research Database (Denmark)

    One of the few things we have in common in contemporary society is the future of our children. But it seems that even the “we” of childhood, of learning and free play, has turned into a common ground for instrumentalization and competition. Today, the pedagogical paradox—Kant’s meditation on the ......? These are some of the questions addressed by The Phantom of Liberty, which sets out to reestablish a social and aesthetic dialogue between visual art and psychology, philosophy, pedagogy, and critical journalism....

  1. Multi-Modality Phantom Development

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Jennifer S.; Peng, Qiyu; Moses, William W.

    2009-03-20

    Multi-modality imaging has an increasing role in the diagnosis and treatment of a large number of diseases, particularly if both functional and anatomical information are acquired and accurately co-registered. Hence, there is a resulting need for multi modality phantoms in order to validate image co-registration and calibrate the imaging systems. We present our PET-ultrasound phantom development, including PET and ultrasound images of a simple prostate phantom. We use agar and gelatin mixed with a radioactive solution. We also present our development of custom multi-modality phantoms that are compatible with PET, transrectal ultrasound (TRUS), MRI and CT imaging. We describe both our selection of tissue mimicking materials and phantom construction procedures. These custom PET-TRUS-CT-MRI prostate phantoms use agargelatin radioactive mixtures with additional contrast agents and preservatives. We show multi-modality images of these custom prostate phantoms, as well as discuss phantom construction alternatives. Although we are currently focused on prostate imaging, this phantom development is applicable to many multi-modality imaging applications.

  2. Persistent double dorsal aorta: A systematic review of the literature.

    Science.gov (United States)

    Mills, Brandy; Gest, Thomas

    2017-05-01

    Our discovery of a case of persistent double dorsal aorta prompted us to systematically review the literature of all previously reported cases of this anomaly. For our case, we present a completely separated double dorsal aorta, with the right accessory aorta arising from the abdominal aorta and ascending through the aortic hiatus to supply posterior intercostal arteries (PIAs) to the 9th-3rd spaces bilaterally. We examined and compiled data from the 10 previously reported cases, along with our observations from our cadaver, into a systematic review of all known cases of persistent double dorsal aorta. In addition to our case report and systematic review, we investigated the literature focusing on formation of the dorsal aorta in the embryo in order to postulate potential mechanisms for formation of this anomaly. Two variants of persistent double dorsal aorta have been reported in the literature. The first type is characterized by a double-lumen descending aorta with a central dividing septum, and the second features complete separation of the two dorsal aortae. The completely separated variant shows further heterogeneity in the origins of the PIAs and the iliac arteries, and the majority of the reported cases also demonstrate additional anatomical anomalies. We outline the events in embryonic dorsal aorta formation as well as discuss several potential mechanisms that could underlie persistent double dorsal aorta formation. Clin. Anat. 30:517-524, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  3. Heterogeneous Breast Phantom Development for Microwave Imaging Using Regression Models

    Directory of Open Access Journals (Sweden)

    Camerin Hahn

    2012-01-01

    Full Text Available As new algorithms for microwave imaging emerge, it is important to have standard accurate benchmarking tests. Currently, most researchers use homogeneous phantoms for testing new algorithms. These simple structures lack the heterogeneity of the dielectric properties of human tissue and are inadequate for testing these algorithms for medical imaging. To adequately test breast microwave imaging algorithms, the phantom has to resemble different breast tissues physically and in terms of dielectric properties. We propose a systematic approach in designing phantoms that not only have dielectric properties close to breast tissues but also can be easily shaped to realistic physical models. The approach is based on regression model to match phantom's dielectric properties with the breast tissue dielectric properties found in Lazebnik et al. (2007. However, the methodology proposed here can be used to create phantoms for any tissue type as long as ex vivo, in vitro, or in vivo tissue dielectric properties are measured and available. Therefore, using this method, accurate benchmarking phantoms for testing emerging microwave imaging algorithms can be developed.

  4. Heterogeneous Breast Phantom Development for Microwave Imaging Using Regression Models

    Science.gov (United States)

    Hahn, Camerin; Noghanian, Sima

    2012-01-01

    As new algorithms for microwave imaging emerge, it is important to have standard accurate benchmarking tests. Currently, most researchers use homogeneous phantoms for testing new algorithms. These simple structures lack the heterogeneity of the dielectric properties of human tissue and are inadequate for testing these algorithms for medical imaging. To adequately test breast microwave imaging algorithms, the phantom has to resemble different breast tissues physically and in terms of dielectric properties. We propose a systematic approach in designing phantoms that not only have dielectric properties close to breast tissues but also can be easily shaped to realistic physical models. The approach is based on regression model to match phantom's dielectric properties with the breast tissue dielectric properties found in Lazebnik et al. (2007). However, the methodology proposed here can be used to create phantoms for any tissue type as long as ex vivo, in vitro, or in vivo tissue dielectric properties are measured and available. Therefore, using this method, accurate benchmarking phantoms for testing emerging microwave imaging algorithms can be developed. PMID:22550473

  5. Multimodal phantom of liver tissue.

    Directory of Open Access Journals (Sweden)

    Magdalena K Chmarra

    Full Text Available Medical imaging plays an important role in patients' care and is continuously being used in managing health and disease. To obtain the maximum benefit from this rapidly developing technology, further research is needed. Ideally, this research should be done in a patient-safe and environment-friendly manner; for example, on phantoms. The goal of this work was to develop a protocol and manufacture a multimodal liver phantom that is suitable for ultrasound, computed tomography, and magnetic resonance imaging modalities. The proposed phantom consists of three types of mimicked soft tissues: liver parenchyma, tumors, and portal veins, that are made of six ingredients: candle gel, sephadex®, agarose, glycerol, distilled water, and silicone string. The entire procedure is advantageous, since preparation of the phantom is simple, rather cost-effective, and reasonably quick - it takes around 2 days. Besides, most of the phantom's parts can be reused to manufacture a new phantom. Comparison of ultrasound images of real patient's liver and the developed phantom shows that the phantom's liver tissue and its structures are well simulated.

  6. Supernumerary phantom limb after stroke

    Science.gov (United States)

    Bakheit, A; Roundhill, S

    2005-01-01

    The perception of a phantom limb is commonly reported after amputations. However, only a few cases have been described after a stroke. This article presents a patient who reported a supernumerary phantom limb (pseudopolymelia) after spontaneous intracerebral haemorrhage and discusses the possible underlying mechanisms for this rare phenomenon. PMID:15749787

  7. A successful case of ascending aorta--abdominal aorta bypass for middle aortic syndrome.

    Science.gov (United States)

    Matsuno, Yukihiro; Mori, Yoshio; Umeda, Yukio; Imaizumi, Matsuhisa; Takiya, Hiroshi

    2009-01-01

    The middle aortic syndrome (MAS) is a rare disease affecting children and young adults, and it occurs in about 0.5% to 2.0% of all aortic coarctation cases. Congenital, acquired, inflammatory, and infectious etiologies have been described. In the majority of cases, there is a short, isolated or diffuse tubular narrowing of the descending thoracic and abdominal aorta, often accompanied by ostial stenosis or occlusion of the renal and visceral branches, which leads to renovascular hypertension and visceral ischemia. Surgical treatment should be considered in cases of uncontrollable hypertension, evidence of end-organ damage such as cardiac failure, progressive renal insufficiency, or severe intermittent claudication. Several surgical treatments for this condition have been reported, including bypass grafting, graft replacement, or patch angioplasty. We report a successful case of ascending aorta-abdominal aorta bypass for MAS in a 11-year-old boy.

  8. Coil embolization of an anastomotic leak after ascending aorta replacement

    DEFF Research Database (Denmark)

    Nørgaard, Anders; Andersen, Lars Ib; Haahr, P.E.

    2008-01-01

    treated aneurysm in the ascending thoracic aorta complicated with an anastomotic leak. If a short prosthesis (6 cm) had been available, the anastomotic leak would have been treated with endovascular repair. In lack of this prosthesis, we were forced to treat the patient with a method not generally......Surgical treatment of diseases of the thoracic aorta (aneurysms, dissections, and ruptures) may be associated with serious postoperative complications. Endovascular repair of thoracic aorta pathology is less invasive and offers a therapeutic alternative in high-surgical-risk patients, particularly...... in the presence of previous surgical repair of the thoracic aorta. The endovascular procedure, however, is almost only possible in the descending thoracic aorta, although advances have also been made in the aortic arch as well as in the ascending aorta with branched stent grafts. We report a case of a surgically...

  9. Data of the natural and pharmaceutical angiotensin-converting enzyme inhibitor isoleucine-tryptophan as a potent blocker of matrix metalloproteinase-2 expression in rat aorta

    Directory of Open Access Journals (Sweden)

    Irakli Kopaliani

    2016-09-01

    Full Text Available The present data are related to the research article entitled “Whey peptide isoleucine–tryptophan inhibits expression and activity of matrix metalloproteinase-2 in rat aorta” [1]. Here we present data on removal of endothelium from aorta, endothelium dependent aortic relaxation and inhibition of expression of pro-MMP2 by di-peptide isoleucine–tryptophan (IW. Experiments were performed in rat aortic endothelial cells (EC and smooth muscle cells (SMC in vitro, along with isolated rat aorta ex vivo. The cells and isolated aorta were stimulated with angiotensin II (ANGII or angiotensin I (ANGI. ACE activity was inhibited by treatment with either IW or captopril (CA. Losartan was used as a blocker of angiotensin type-1 receptor. IW inhibited MMP2 protein expression induced with ANGI in a dose-dependent manner. IW was effective both in ECs and SMCs, as well as in isolated aorta. Similarly, captopril (CA inhibited ANGI-induced MMP2 protein expression in both in vitro and ex vivo. Neither IW nor CA inhibited ANGII-induced MMP2 protein expression in contrast to losartan. The data also displays that removal of endothelium in isolated rat aorta abolished the endothelium-dependent relaxation induced with acetylcholine. However, SMC-dependent relaxation induced with sodium nitroprusside remained intact. Finally, the data provides histological evidence of selective removal of endothelial cells from aorta.

  10. Phantom limbs and neural plasticity.

    Science.gov (United States)

    Ramachandran, V S; Rogers-Ramachandran, D

    2000-03-01

    The study of phantom limbs has received tremendous impetus from recent studies linking changes in cortical topography with perceptual experience. Systematic psychophysical testing and functional imaging studies on patients with phantom limbs provide 2 unique opportunities. First, they allow us to demonstrate neural plasticity in the adult human brain. Second, by tracking perceptual changes (such as referred sensations) and changes in cortical topography in individual patients, we can begin to explore how the activity of sensory maps gives rise to conscious experience. Finally, phantom limbs also allow us to explore intersensory effects and the manner in which the brain constructs and updates a "body image" throughout life.

  11. Fetal Isolated Anomalous Origin of Right Pulmonary Artery from Aorta

    Directory of Open Access Journals (Sweden)

    Shi Zeng

    2015-04-01

    Full Text Available The anomalous origin of a branch pulmonary artery from the aorta (AOPA is characterized by the anomalous origin of one of the branch pulmonary arteries (PA from the ascending aorta and a normal origin of the other PA from main PA. AOPA is an extremely rare cardiac malformation. Few studies have reported fetal anomalous origin of PA from aorta with other malformation. We report a case of isolated distal anomalous origin of the right PA from the aorta that was diagnosed by fetal echocardiography at 25 weeks' of gestation. Tracing the course of PA branches is important to make diagnosis.

  12. Fetal Isolated Anomalous Origin of Right Pulmonary Artery from Aorta.

    Science.gov (United States)

    Zeng, Shi; Zhou, Qichang; Zhou, Jiawei; Peng, Qinghai

    2015-04-01

    The anomalous origin of a branch pulmonary artery from the aorta (AOPA) is characterized by the anomalous origin of one of the branch pulmonary arteries (PA) from the ascending aorta and a normal origin of the other PA from main PA. AOPA is an extremely rare cardiac malformation. Few studies have reported fetal anomalous origin of PA from aorta with other malformation. We report a case of isolated distal anomalous origin of the right PA from the aorta that was diagnosed by fetal echocardiography at 25 weeks' of gestation. Tracing the course of PA branches is important to make diagnosis.

  13. Aneurisma adquirido de aorta ascendente em criança Acquired neurysm of the ascending aorta in children

    Directory of Open Access Journals (Sweden)

    Danton R. da Rocha Loures

    1989-04-01

    Full Text Available O aneurisma adquirido da aorta ascendente é uma rara condição na faixa pediátrica. Os autores apresentam 2 casos de crianças de 6 e 12 anos de idade com aneurisma sacular da aorta ascendente e estenose aórtica, os quais foram submetidos a correção cirúrgica, com sucesso.Acquired aneurysm of the ascending aorta is a rare condition in the pediatric age group. The authors present two cases of 6 and 12 year old boys with saccular aneurysm of the ascending aorta and aortic stenosis, which underwent successful surgical correction.

  14. Realistic analytical polyhedral MRI phantoms.

    Science.gov (United States)

    Ngo, Tri M; Fung, George S K; Han, Shuo; Chen, Min; Prince, Jerry L; Tsui, Benjamin M W; McVeigh, Elliot R; Herzka, Daniel A

    2016-08-01

    Analytical phantoms have closed form Fourier transform expressions and are used to simulate MRI acquisitions. Existing three-dimensional (3D) analytical phantoms are unable to accurately model shapes of biomedical interest. The goal of this study was to demonstrate that polyhedral analytical phantoms have closed form Fourier transform expressions and can accurately represent 3D biomedical shapes. The Fourier transform of a polyhedron was implemented and its accuracy in representing faceted and smooth surfaces was characterized. Realistic anthropomorphic polyhedral brain and torso phantoms were constructed and their use in simulated 3D and two-dimensional (2D) MRI acquisitions was described. Using polyhedra, the Fourier transform of faceted shapes can be computed to within machine precision. Smooth surfaces can be approximated with increasing accuracy by increasing the number of facets in the polyhedron; the additional accumulated numerical imprecision of the Fourier transform of polyhedra with many faces remained small. Simulations of 3D and 2D brain and 2D torso cine acquisitions produced realistic reconstructions free of high frequency edge aliasing compared with equivalent voxelized/rasterized phantoms. Analytical polyhedral phantoms are easy to construct and can accurately simulate shapes of biomedical interest. Magn Reson Med 76:663-678, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  15. [Pulmonary and pleural complications of the descending aorta surgery].

    Science.gov (United States)

    Belov, Iu V; Komarov, R N; Stepanenko, A B; Gasanov, A F

    2013-01-01

    The experience of surgical treatment of 84 patients with diseases of the descending thoracic aorta was analyzed. Frequency and structure of pleura-pulmonary complications after reconstructive surgery of the descending aorta were thoroughly registered. 58.3% of the operated patints developed complications. The most frequent complication was the acute respiratory insufficiency in early postoperative period (29.76% of patients).

  16. Role of endothelin in thrombolysis in rat abdominal aorta.

    Science.gov (United States)

    Tang, Y; Yao, X; Tang, C

    1998-01-01

    The endothelium of blood vessels is of great importance in maintaining blood fluidity and modulating thrombogenesis. Endothelin (ET) participates in thrombogenesis and its role in the pathogenesis of heart diseases such as acute myocardinal infarction has been proved, but little is known about the effect of ET on thrombolysis. Using a model of thrombosis in rat abdominal aorta induced by direct current-ferric trichloride, we found that the plasma ET level was 3.7 times the baseline after lysing the thrombus with urokinase (250,000 U/kg) while 5 micrograms/kg of exogenous ET prolonged the time of thrombolysis to 115% of baseline control. Plasma ET level was six times the baseline level. Incubation of a rat aortic strip in vitro with taurine (20 mmol/L) had no effect on baseline ET release, but taurine prohibited the stimulation of thrombin and A23187 of ET release in a dose-dependent way. Plasma ET decreased between 17 and 40% after injection of taurine, which also decreased by 45% the time of lysis of thrombus. From the above data it might be concluded that ET inhibits thrombolysis and that the abnormally increasing plasma ET can be attenuated by taurine, which is beneficial to thrombolysis.

  17. Pharmacological Studies of Tentacle Extract from the Jellyfish Cyanea capillata in Isolated Rat Aorta

    Directory of Open Access Journals (Sweden)

    Liming Zhang

    2013-08-01

    Full Text Available Our previous studies demonstrated that tentacle extract (TE from the jellyfish, Cyanea capillata, could cause a dose-dependent increase of systolic blood pressure, which seemed to be the result of direct constriction of vascular smooth muscle (VSM. The aim of this study is to investigate whether TE could induce vasoconstriction in vitro and to explore its potential mechanism. Using isolated aorta rings, a direct contractile response of TE was verified, which showed that TE could induce concentration-dependent contractile responses in both endothelium-intact and -denuded aortas. Interestingly, the amplitude of contraction in the endothelium-denuded aorta was much stronger than that in the endothelium-intact one, implying that TE might also bring a weak functional relaxation in addition to vasoconstriction. Further drug intervention experiments indicated that the functional vasodilation might be mediated by nitric oxide, and that TE-induced vasoconstriction could be attributed to calcium influx via voltage-operated calcium channels (VOCCs from the extracellular space, as well as sarcoplasmic reticulum (SR Ca2+ release via the inositol 1,4,5-trisphosphate receptor (IP3R, leading to an increase in [Ca2+]c, instead of activation of the PLC/DAG/PKC pathway or the sympathetic nerve system.

  18. Pharmacological studies of tentacle extract from the jellyfish Cyanea capillata in isolated rat aorta.

    Science.gov (United States)

    Wang, Beilei; Zhang, Bo; Wang, Qianqian; Zhang, Zhi; Nie, Fei; Liu, Guoyan; Zheng, Jiemin; Xiao, Liang; Zhang, Liming

    2013-08-30

    Our previous studies demonstrated that tentacle extract (TE) from the jellyfish, Cyanea capillata, could cause a dose-dependent increase of systolic blood pressure, which seemed to be the result of direct constriction of vascular smooth muscle (VSM). The aim of this study is to investigate whether TE could induce vasoconstriction in vitro and to explore its potential mechanism. Using isolated aorta rings, a direct contractile response of TE was verified, which showed that TE could induce concentration-dependent contractile responses in both endothelium-intact and -denuded aortas. Interestingly, the amplitude of contraction in the endothelium-denuded aorta was much stronger than that in the endothelium-intact one, implying that TE might also bring a weak functional relaxation in addition to vasoconstriction. Further drug intervention experiments indicated that the functional vasodilation might be mediated by nitric oxide, and that TE-induced vasoconstriction could be attributed to calcium influx via voltage-operated calcium channels (VOCCs) from the extracellular space, as well as sarcoplasmic reticulum (SR) Ca²⁺ release via the inositol 1,4,5-trisphosphate receptor (IP₃R), leading to an increase in [Ca²⁺](c), instead of activation of the PLC/DAG/PKC pathway or the sympathetic nerve system.

  19. AORTA: Adding Organizational Reasoning to Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia

    2014-01-01

    the expected behavior of the agents. Agents need to be able to reason about the regulations, so that they can act within the expected boundaries and work towards the objectives of the organization. This extended abstract introduces AORTA, a component that can be integrated into agents’ reasoning mechanism......Open systems are characterized by a diversity of heterogeneous and autonomous agents that act according to private goals, and with a behavior that is hard to predict. They can be regulated through organizations similar to human organizations, which regulate the agents’ behavior space and describe......, allowing them to reason about (and act upon) regulations specified by an organizational model using simple reasoning rules. The added value is that the organizational model is independent of that of the agents, and that the approach is not tied to a specific organizational model....

  20. The Effect of Chlorpyrifos on Isolated Thoracic Aorta in Rats

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    Ebru Yıldırım

    2013-01-01

    Full Text Available This study investigated the effect of chlorpyrifos on thoracic aorta and on the level of NO in plasma and aorta. The effect of chlorpyrifos on thoracic aorta in organ bath was determined in 10 rats. Another 45 rats were assigned to 3 groups with 15 rats each: control group 1 received distilled water, control group 2 was given corn oil, and the last group was given 13.5 mg/kg chlorpyrifos dissolved in corn oil every other day for 8 weeks orally. Chlorpyrifos (10−10 M–10−5 M showed no effect on isolated thoracic aorta. Plasma AChE activity was decreased, while LDH, ALT, GGT, and AST activities were increased in chlorpyrifos group compared to control groups. Plasma NO level was increased in chlorpyrifos group compared to control groups. iNOS expression was present in all groups in the cytoplasm of the endothelia and in the smooth muscle cells of aorta. According to semiquantitative histomorphological analysis, iNOS immunopositive reactions were seen in the decreasing order in chlorpyrifos, control 2, and control 1 groups. eNOS immunopositive reactions were observed in the endothelial cell cytoplasm, rarely in the subintimal layer, and the smooth muscle cells of aorta. There were no differences among the groups in terms of eNOS immunostaining. In conclusion, chlorpyrifos induced NO production in aorta following an increase in NOS expression.

  1. Anatomically correct deformable colon phantom

    Science.gov (United States)

    Norris, James A.; Barton, Michael D.; Davis, Brynmor J.; Bieszczad, Jerry; Meunier, Norm L.; Brown, Nathan W.; Kynor, David B.

    2011-03-01

    We describe a technique to build a soft-walled colon phantom that provides realistic lumen anatomy in computed tomography (CT) images. The technique begins with the geometry of a human colon measured during CT colonography (CTC). The three-dimensional air-filled colonic lumen is segmented and then replicated using stereolithography (SLA). The rigid SLA model includes large-scale features (e.g., haustral folds and tenia coli bands) down to small-scale features (e.g., a small pedunculated polyp). Since the rigid model represents the internal air-filled volume, a highly-pliable silicone polymer is painted onto the rigid model. This thin layer of silicone, when removed, becomes the colon wall. Small 3 mm diameter glass beads are affixed to the outer wall. These glass beads show up with high intensity in CT scans and provide a ground truth for evaluating performance of algorithms designed to register prone and supine CTC data sets. After curing, the silicone colon wall is peeled off the rigid model. The resulting colon phantom is filled with air and submerged in a water bath. CT images and intraluminal fly-through reconstructions from CTC scans of the colon phantom are compared against patient data to demonstrate the ability of the phantom to simulate a human colon.

  2. Phantom pain : A sensitivity analysis

    NARCIS (Netherlands)

    Borsje, Susanne; Bosmans, JC; Van der Schans, CP; Geertzen, JHB; Dijkstra, PU

    2004-01-01

    Purpose : To analyse how decisions to dichotomise the frequency and impediment of phantom pain into absent and present influence the outcome of studies by performing a sensitivity analysis on an existing database. Method : Five hundred and thirty-six subjects were recruited from the database of an

  3. Tachyonic field interacting with scalar (phantom) field

    OpenAIRE

    Chattopadhyay, Surajit; Debnath, Ujjal

    2009-01-01

    In this letter, we have considered the universe is filled with the mixture of tachyonic field and scalar or phantom field. If the tachyonic field interacts with scalar or phantom field, the interaction term decays with time and the energy for scalar field is transferred to tachyonic field or the energy for phantom field is transferred to tachyonic field. The tachyonic field and scalar field potentials always decrease, but phantom field potential always increases.

  4. 6-Gingerol alleviates exaggerated vasoconstriction in diabetic rat aorta through direct vasodilation and nitric oxide generation

    Directory of Open Access Journals (Sweden)

    Ghareib SA

    2015-11-01

    Full Text Available Salah A Ghareib,1 Hany M El-Bassossy,1,2 Ahmed A Elberry,3,4 Ahmad Azhar,5 Malcolm L Watson,6 Zainy Mohammed Banjar7 1Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 2Department of Pharmacology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt; 3Department of Clinical Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 4Department of Pharmacology, Faculty of Medicine, Beni Suef University, Beni Suef, Egypt; 5Department of Pediatric Cardiology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia; 6Department of Pharmacy and Pharmacology, University of Bath, Bath, UK; 7Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia Abstract: The aim of the present study is to investigate the effect and potential mechanism of action of 6-gingerol on alterations of vascular reactivity in the isolated aorta from diabetic rats. Male Wistar rats were divided into two experimental groups, control and diabetics. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg kg-1, and the rats were left for 10 weeks to develop vascular complications. The effect of in vitro incubation with 6-gingerol (0.3–3 µM on the vasoconstrictor response of the isolated diabetic aortae to phenylephrine and the vasodilator response to acetylcholine was examined. Effect of 6-gingerol was also examined on aortae incubated with methylglyoxal as an advanced glycation end product (AGE. To investigate the mechanism of action of 6-gingerol, the nitric oxide synthase inhibitor Nω-nitro-L-arginine methyl ester hydrochloride (100 µM, guanylate cyclase inhibitor methylene blue (5 µM, calcium-activated potassium channel blocker tetraethylammonium chloride (10 mM, and cyclooxygenase inhibitor indomethacin (5 µM were added 30 minutes before assessing the direct vasorelaxant effect of 6

  5. A comparative study on patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2015-01-01

    Full Text Available Purpose: To compare the results of patient specific absolute dosimetry using slab phantom, acrylic body phantom and goat head phantom. Methods: Fifteen intensity modulated radiotherapy (IMRT plans already planned on treatment planning system (TPS for head-and-neck cancer patients were exported on all three kinds of phantoms viz. slab phantom, acrylic body phantom and goat head phantom, and dose was calculated using anisotropic analytic algorithm (AAA. All the gantry angles were set to zero in case of slab phantom while set to as it is in actual plan in case of other two phantoms. All the plans were delivered by linear accelerator (LA and dose for each plan was measured by 0.13 cc ion chamber. The percentage (% variations between planned and measured doses were calculated and analyzed. Results: The mean % variations between planned and measured doses of all IMRT quality assurance (QA plans were as 0.65 (Standard deviation (SD: 0.38 with confidence limit (CL 1.39, 1.16 (SD: 0.61 with CL 2.36 and 2.40 (SD: 0.86 with CL 4.09 for slab phantom, acrylic head phantom and goat head phantom respectively. Conclusion: Higher dose variations found in case of real tissue phantom compare to results in case of slab and acrylic body phantoms. The algorithm AAA does not calculate doses in heterogeneous medium as accurate as it calculates in homogeneous medium. Therefore the patient specific absolute dosimetry should be done using heterogeneous phantom mimicking density wise as well as design wise to the actual human body.  

  6. Anomalous Posterior Intercostal Arterial Trunk Arising From the Abdominal Aorta

    Energy Technology Data Exchange (ETDEWEB)

    Jie, Bing, E-mail: jbshh@163.com; Yu, Dong, E-mail: yudong-mail@126.com; Jiang, Sen, E-mail: jasfly77@vip.163.com [Tongji University School of Medicine, Department of Radiology, Shanghai Pulmonary Hospital (China)

    2016-04-15

    A common trunk of the ipsilateral posterior intercostal artery (PIA) arising from the thoracic aorta is usually an anatomical variation. However, a common trunk of bilateral posterior intercostal arterial trunk (PIAT) arising from the abdominal aorta is rare. It is important to recognize this anatomical variation of PIA when performing interventional radiological procedures. We present a rare case of an anomalous PIAT that originated from the abdominal aorta in a patient with hemoptysis caused by tuberculosis sequelae. Bilateral 4th to 11th PIAs arose from a common trunk and the trunk arising from the posterior aspect of the abdominal aorta at the level of T12/L1 intervertebral space. The pathological right 4th and 5th PIAs and bronchial arteries were embolized. Hemoptysis has been controlled for 3 months.

  7. Phantom model of physiologic intracranial pressure and cerebrospinal fluid dynamics.

    Science.gov (United States)

    Bottan, Simone; Poulikakos, Dimos; Kurtcuoglu, Vartan

    2012-06-01

    We describe herein a novel life-size phantom model of the intracranial cavity and its validation. The cerebrospinal fluid (CSF) domains including ventricular, cysternal, and subarachnoid spaces were derived via magnetic resonance imaging. Brain mechanical properties and cranio-spinal compliance were set based on published data. Both bulk and pulsatile physiologic CSF flow were modeled. Model validation was carried out by comparisons of flow and pressure measurements in the phantom with published in vivo data of healthy subjects. Physiologic intracranial pressure with 10 mmHg mean and 0.4 mmHg peak pulse amplitude was recorded in the ventricles. Peak CSF flow rates of 0.2 and 2 ml/s were measured in the cerebral aqueduct and subarachnoid space, respectively. The phantom constitutes a first-of-its-kind approach to modeling physiologic intracranial dynamics in vitro. Herein, we describe the phantom design and manufacturing, definition and implementation of its operating parameters, as well as the validation of the modeled dynamics.

  8. Phantom Recollection of Bridging and Elaborative Inferences

    Science.gov (United States)

    Singer, Murray; Spear, Jackie

    2015-01-01

    The phantom recollection model is a multiprocess analysis according to which memory judgments are collaboratively supported by one's recollection of an item in its context, a vaguer sense of stimulus familiarity, and the phantom recollection of the substance and even perceptual details of unstudied but related lures. Phantom recollection has…

  9. Phantom pain in bilateral upper limb amputation.

    Science.gov (United States)

    Modirian, Ehsan; Shojaei, Hadi; Soroush, Mohammad Reza; Masoumi, Mahdi

    2009-01-01

    To alert health professionals on presence and extent of phantom pain and sensation following bilateral upper limb amputation. Of a total of 140 war-related bilateral upper limb amputees in Iran, 103 subjects were thoroughly examined in this cross-sectional study by a physical medicine specialist. The patients were questioned for the presence of phantom pain and sensations, and frequency and intensity of the feeling were recorded. At 17.1 +/- 6.1 years after injury, 82.0% of the 103 amputees suffered from phantom sensation, including varying degrees of phantom limb pain in 53.9% of stumps. Phantom phenomena had a higher frequency in the right extremities, but this was not statistically significant (p > 0.01). Of those amputees who had phantom pain or sensation, 51.2% reported that they 'always' had phantom limb sensation; and approximately one-fourth of the subjects (24.6%) 'always' had phantom pain. Among the stumps who reported phantom pain (N=112), the pain was excruciating (38.5%), distressing (34.9%) or discomforting (25.6%). A significant statistical relation between phantom limb sensation and level of amputation was observed (p phantom pain; medical and surgical modalities only bring temporary relief, and less than 1% of the respondents achieve permanent relief through different treatment methods.

  10. Neural correlates of evoked phantom limb sensations.

    Science.gov (United States)

    Andoh, J; Diers, M; Milde, C; Frobel, C; Kleinböhl, D; Flor, H

    2017-05-01

    Previous work showed the existence of changes in the topographic organization within the somatosensory cortex (SI) in amputees with phantom limb pain, however, the link between nonpainful phantom sensations such as cramping or tingling or the percept of the limb and cortical changes is less clear. We used functional magnetic resonance imaging (fMRI) in a highly selective group of limb amputees who experienced inducible and reproducible nonpainful phantom sensations. A standardized procedure was used to locate body sites eliciting phantom sensations in each amputee. Selected body sites that could systematically evoke phantom sensations were stimulated using electrical pulses in order to induce phasic phantom sensations. Homologous body parts were also stimulated in a group of matched controls. Activations related to evoked phantom sensations were found bilaterally in SI and the intraparietal sulci (IPS), which significantly correlated with the intensity of evoked phantom sensations. In addition, we found differences in intra- and interhemispheric interaction between amputees and controls during evoked phantom sensations. We assume that phantom sensations might be associated with a functional decoupling between bilateral SI and IPS, possibly resulting from transcallosal reorganization mechanisms following amputation. Copyright © 2017. Published by Elsevier B.V.

  11. Psychophysical correlates of phantom limb experience.

    Science.gov (United States)

    Katz, J

    1992-01-01

    Phantom limb phenomena were correlated with psychophysiological measures of peripheral sympathetic nervous system activity measured at the amputation stump and contralateral limb. Amputees were assigned to one of three groups depending on whether they reported phantom limb pain, non-painful phantom limb sensations, or no phantom limb at all. Skin conductance and skin temperature were recorded continuously during two 30 minute sessions while subjects continuously monitored and rated the intensity of any phantom limb sensation or pain they experienced. The results from both sessions showed that mean skin temperature was significantly lower at the stump than the contralateral limb in the groups with phantom limb pain and non-painful phantom limb sensations, but not among subjects with no phantom limb at all. In addition, stump skin conductance responses correlated significantly with the intensity of non-painful phantom limb paresthesiae but not other qualities of sensation or pain. Between-limb measures of pressure sensitivity were not significantly different in any group. The results suggest that the presence of a phantom limb, whether painful or painless, is related to the sympathetic-efferent outflow of cutaneous vasoconstrictor fibres in the stump and stump neuromas. The hypothesis of a sympathetic-efferent somatic-afferent mechanism involving both sudomotor and vasoconstrictor fibres is proposed to explain the relationship between stump skin conductance responses and non-painful phantom limb paresthesiae. It is suggested that increases in the intensity of phantom limb paresthesiae follow bursts of sympathetic activity due to neurotransmitter release onto apposing sprouts of large diameter primary afferents located in stump neuromas, and decreases correspond to periods of relative sympathetic inactivity. The results of the study agree with recent suggestions that phantom limb pain is not a unitary syndrome, but a symptom class with each class subserved by

  12. Aorta Ascending Aneurysm Analysis Using CFD Models towards Possible Anomalies

    Directory of Open Access Journals (Sweden)

    Mariana Simão

    2017-06-01

    Full Text Available Computational fluid dynamics (CFD can be seen as complementary tool alongside the visualization capabilities of cardiovascular magnetic resonance (CMR and computed tomography (CT imaging for decision-making. In this research CT images of three cases (i.e., a healthy heart pilot project and two patients with complex aortic disease are used to validate and analyse the corresponding computational results. Three 3D domains of the thoracic aorta were tested under hemodynamic conditions. Under normal conditions, the flow inside the thoracic aorta is more streamlined. In the presence of ascending aortic aneurysm, large areas of blue separation zones (i.e., low velocities are identified, as well as an internal geometry deformation of the aortic wall, respectively. This flow separation is characterized by the reversal of flow and sudden drop of the wall shear stress (WSS in the aorta. Moreover, the aortic aneurysm simulations adversely affect the flow by increasing the pressure drop and flow inefficiency, due to the anatomical configuration of the ascending aorta. Altered hemodynamics led to a vortex formation and locally reversed the flow that eventually induced a low flow velocity and oscillating WSS in the thoracic aorta. Significant changes in the hemodynamic characteristics affect the normal blood circulation with strong turbulence occurrence, damaging the aortic wall, leading ultimately to the need of surgical intervention to avoid fatal events.

  13. Cysteine-674 oxidation and degradation of sarcoplasmic reticulum Ca(2+) ATPase in diabetic pig aorta.

    Science.gov (United States)

    Ying, Jia; Sharov, Victor; Xu, Shanqin; Jiang, Bingbing; Gerrity, Ross; Schöneich, Christian; Cohen, Richard A

    2008-09-15

    The sarcoplasmic reticulum Ca2+ ATPase (SERCA) is redox-regulated by posttranslational thiol modifications of cysteine-674 to regulate smooth muscle relaxation and migration. To detect oxidation of cysteine-674 that irreversibly prevents redox regulation, a polyclonal, sequence-specific antibody was developed toward a peptide containing cysteine-674 sulfonic acid. The antibody stained intact 110-kDa SERCA in pig cardiac SR that was oxidized in vitro by peroxynitrite in a sequence-specific manner, and histochemically stained atherosclerotic pig and rabbit aorta. Surprisingly, immunoblots of the pig aorta failed to stain intact 110-kDa SERCA protein, but rather, higher molecular mass aggregates and lower molecular mass bands. Of the latter bands at 70 and 60 kDa, the largest were observed in diabetic, hyperlipidemic pigs, and coincided with the most positive histochemical staining. The 70- and 60-kDa molecular mass bands also coincided with the majority of the protein detected by a monoclonal total anti-SERCA antibody, which detected the intact 110-kDa protein in normal pigs. Mass spectrometry identified SERCA in all the major bands detected by the sulfonic acid antibody as well as the oxidation of cysteine-674 in the 70-kDa band. These studies demonstrate a sequence-specific antibody that detects partial degradation products of SERCA, which represent the majority of the protein in some diabetic hypercholesterolemic pig aortae. In addition, the results suggest an association between irreversible oxidation of SERCA and its degradation, and that an important portion of the oxidized protein in tissue samples may be partially degraded.

  14. Dissecção espontânea da aorta abdominal infrarrenal Spontaneous dissection of the infrarenal aorta

    Directory of Open Access Journals (Sweden)

    Otacílio de Camargo Junior

    2012-09-01

    Full Text Available A rotura da camada íntima que marca o início da dissecção aórtica se origina na maioria dos casos na aorta torácica, sendo rara a dissecção espontânea da aorta abdominal infra-renal. As três principais causas são: iatrogênica, traumática ou espontânea. A dor abdominal e a isquemia de membros são os sintomas mais comuns e um número significativo de pacientes e´ assintomatico. O diagnóstico tem sido feito através de métodos de imagem como ultrassonografia, tomografia computadorizada, ressonância nuclear magnética e angiografia aliados ao alto índice de suspeição. Relatamos os casos de duas pacientes que apresentaram dissecção de aorta abdominal infrarrenal com quadro de dor abdominal súbita, sem sinais de irritação peritoneal com pulsos presentes e simétricos ao exame físico que deram entrada no pronto socorro do Hospital e Maternidade Celso Pierro da PUC Campinas e que foram tratadas pela equipe de Cirurgia Vascular. As duas pacientes no momento do exame apresentavam-se hipertensas e ao ultrassom apresentavam alteração da conformidade da aorta abdominal que foram tratada s cirurgicamente. Uma paciente foi tratada cirurgicamente submetida a endarterectomia da placa dissecada da aorta abdominal infrarrenal de 2,2 cm de diâmetro e 2,0 cm de extensão. A outra paciente foi submetida a revascularização da aorta abdominal bi-iliaca com prótese de Dacron 16 × 8 mm por apresentar disseccao da aorta abdominal distal. As duas pacientes apresentaram boa evolução pos-operatoria tendo alta hospitalar em bom estado geral.The rupture of the intimal layer marks the beginning of the aortic dissection, which usually happens in the thoracic aorta. The spontaneous dissection of the infrarenal aorta is rare. The main causes are: iatrogenic, traumatic and spontaneous. Abdominal pain and limb ischemia are the commonest symptoms, and some patients are asymptomatics. The diagnosis is made by ultrasound, computed tomography

  15. Plural large floating thrombi in the ascending aorta.

    Science.gov (United States)

    Harada, Hisao; Soeda, Takeshi; Saitoh, Yuhei; Nakahara, Takahiro

    2016-08-01

    Floating thrombi in the ascending aorta are a very rare finding in non-aneurysmal, mildly atherosclerotic or normal aortas. We report a case of floating thrombi in a 66-year-old man who was admitted to the hospital with acute chest pain and dyspnea. Enhanced computed tomography showed two large floating thrombi in the ascending aorta, type B aortic dissection, deep venous thrombosis, and pulmonary embolism. A temporary inferior vena cava filter was inserted and the subject underwent an emergency surgical intervention to remove both masses. His postoperative course was uneventful; the etiology of the thrombi is unknown. Lifelong anticoagulation therapy was started and the subject has been stable without recurrence for the last 2 years.

  16. Congenital Saccular Aneurysm of Coarctation of Aorta: A Case Report

    Directory of Open Access Journals (Sweden)

    Hassan Teimouri

    2015-10-01

    Full Text Available True saccular aneurysm is exceptional in coarctation of aorta in children. A 6-year-old girl with headache and systemic arterial hypertension referred to our center for cardiovascular evaluation. Physical examination revealed high blood pressure and weak lower extremity pulses. Two-dimensional and Doppler echocardiography and angiography demonstrated a saccular aneurysm of the descending aorta, 5×4 cm in size, associated with aortic coarctation. Aneurysmectomy was performed without cardiopulmonary bypass. The section of the aorta containing the coarctation and the aneurysm was resected and replaced with a 15-mm woven polyester graft. Histological examination revealed a thin walled aneurysm with hyalinosis changes and decreased elastic fibers. One-year echocardiographic follow-up revealed no gradient across of Dacron tube and hypertension decreased to normal level.

  17. [Phantom limb pain: from physiopathology to prevention].

    Science.gov (United States)

    Roullet, S; Nouette-Gaulain, K; Brochet, B; Sztark, F

    2009-05-01

    First described in 1545, phantom limb pain is a frequent complication after limb amputation, described by 60 to 85% of amputees. Stump pain, phantom limb sensation and phantom limb pain are often combined. Physiopathology is complex and peripheral, medullar and cortical mechanisms are combined. Pharmacological preventive treatments as well as regional anaesthesia techniques have equivalent results. Such treatments must be investigated more precisely as postoperative rehabilitation of amputees mostly depends on pain relief.

  18. Neutron dosimetry in solid water phantom

    Energy Technology Data Exchange (ETDEWEB)

    Benites-Rengifo, Jorge Luis, E-mail: jlbenitesr@prodigy.net.mx [Centro Estatal de Cancerologia de Nayarit, Calzada de la Cruz 118 Sur, Tepic Nayarit, Mexico and Instituto Tecnico Superior de Radiologia, ITEC, Calle Leon 129, Tepic Nayarit (Mexico); Vega-Carrillo, Hector Rene, E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Apdo. postal 336, 98000, Zacatecas, Zac. (Mexico)

    2014-11-07

    The neutron spectra, the Kerma and the absorbed dose due to neutrons were estimated along the incoming beam in a solid water phantom. Calculations were carried out with the MCNP5 code, where the bunker, the phantom and the model of the15 MV LINAC head were modeled. As the incoming beam goes into the phantom the neutron spectrum is modified and the dosimetric values are reduced.

  19. Motor correlates of phantom limb pain.

    Science.gov (United States)

    Kikkert, Sanne; Mezue, Melvin; Henderson Slater, David; Johansen-Berg, Heidi; Tracey, Irene; Makin, Tamar R

    2017-10-01

    Following amputation, individuals ubiquitously report experiencing lingering sensations of their missing limb. While phantom sensations can be innocuous, they are often manifested as painful. Phantom limb pain (PLP) is notorious for being difficult to monitor and treat. A major challenge in PLP management is the difficulty in assessing PLP symptoms, given the physical absence of the affected body part. Here, we offer a means of quantifying chronic PLP by harnessing the known ability of amputees to voluntarily move their phantom limbs. Upper-limb amputees suffering from chronic PLP performed a simple finger-tapping task with their phantom hand. We confirm that amputees suffering from worse chronic PLP had worse motor control over their phantom hand. We further demonstrate that task performance was consistent over weeks and did not relate to transient PLP or non-painful phantom sensations. Finally, we explore the neural basis of these behavioural correlates of PLP. Using neuroimaging, we reveal that slower phantom hand movements were coupled with stronger activity in the primary sensorimotor phantom hand cortex, previously shown to associate with chronic PLP. By demonstrating a specific link between phantom hand motor control and chronic PLP, our findings open up new avenues for PLP management and improvement of existing PLP treatments. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  20. Giant Candida mycetoma in an ascending aorta tubular graft.

    Science.gov (United States)

    Di Benedetto, Giuseppe; Citro, Rodolfo; Longobardi, Antonio; Mastrogiovanni, Generoso; Panza, Antonio; Iesu, Severino; Bossone, Eduardo

    2013-09-01

    We report the case of a 46-year-old male hospitalized for abdominal pain and fever with history of a David procedure followed by an aortic valve replacement due to severe aortic regurgitation. Transesophageal echocardiography (TEE) and computed tomography showed a large mass floating in the aorta. After surgical excision of the vegetation, attached to the Dacron prosthesis, histological examination revealed Candida hyphae and spores confirming the diagnosis of a mycetoma in an ascending aorta tubular graft. At six-month follow-up, the patient was in good clinical condition without recurrence of the fungal mass on TEE. © 2013 Wiley Periodicals, Inc.

  1. Surgery for pseudoaneurysm of the ascending aorta under moderate hypothermia

    Directory of Open Access Journals (Sweden)

    Lee Dong-Hyup

    2011-09-01

    Full Text Available Abstract Pseudoaneurysm of the ascending aorta is a rare complication after cardiac surgery. Particularly, pseudoaneurysm due to postoperative infection in the ascending aorta requires surgical treatment with antibiotics. If a large sized pseudoaneurysm is located at the retrosternal space, then there is a very high risk of massive bleeding from rupture during performance of resternotomy. To avoid this risk, we performed femoro-femoral bypass under moderate hypothermia with transient circulatory arrest, and we report here on the successful result of this case.

  2. Dynamic eye phantom for retinal oximetry measurements

    Science.gov (United States)

    Lemaillet, Paul; Ramella-Roman, Jessica C.

    2009-11-01

    Measurements of oxygen saturation and flow in the retina can yield information about eye health and the onset of eye pathologies such as diabetic retinopathy. Recently, we developed a multiaperture camera that uses the division of the retinal image into several wavelength-sensitive subimages to compute retinal oxygen saturation. The calibration of such instruments is particularly difficult due to the layered structure of the eye and the lack of alternative measurement techniques. For this purpose, we realize an in vitro model of the human eye composed of a lens, the retina vessel, and three layers: the choroid, the retinal pigmented epithelium, and the sclera. The retinal vessel is modeled with a microtube connected to a micropump and a hemoglobin reservoir in a closed circulatory system. Hemoglobin oxygenation in the vessel could be altered using a reversible fuel cell. The sclera is represented by a Spectralon slab. The optical properties of the other layers are mimicked using titanium dioxide as a scatterer, ink as an absorber, and epoxy as a supporting structure. The optical thickness of each layer of the eye phantom is matched to each respective eye layer.

  3. Phantom pain and risk factors : A multivariate analysis

    NARCIS (Netherlands)

    Dijkstra, PU; Geertzen, JHB; Stewart, R; van der Schans, CP

    2002-01-01

    Phantom pain has been given considerable attention in literature. Phantom Pain reduces quality of life, and patients suffering from phantom pain make heavy use of the medical system. Many risk factors have been identified for phantom Pain in univariate analyses, including phantom sensations, stump

  4. Phantom pain and phantom sensations in upper limb amputees : an epidemiological study

    NARCIS (Netherlands)

    Kooijman, CM; Dijkstra, PU; Geertzen, JHB; Elzinga, A; van der Schans, CP

    Phantom pain in subjects with an amputated limb is a well-known problem. However, estimates of the prevalence of phantom pain differ considerably in the literature. Various factors associated with phantom pain have been described including pain before the amputation, gender, dominance, and time

  5. Do you believe in phantoms?

    CERN Multimedia

    Rosaria Marraffino

    2015-01-01

    “Phantoms” are tools that simulate a therapy’s response by mimicking the conditions of the human body. They are required in hadron therapy in order to optimise and verify the therapy before performing it on the patient. The better the phantom, the more accurate the treatment plan and the more effective the therapy. In the framework of the EU-funded project ENTERVISION*, a team of CERN researchers has designed an innovative piece of equipment able to evaluate radiobiology-related parameters in a very accurate way.   The ENTERVISION phantom being tested at HIT. A key challenge in hadron therapy – i.e. the medical use of hadrons to treat cancer – is to evaluate the biological effect of the delivered radiation. This can be achieved by using accurate dosimetry techniques to study the biological response in terms of the dose deposited and other physical parameters of the beam, such as the Linear Energy Transfer (LET). The job of the “phan...

  6. The phantom limb in dreams.

    Science.gov (United States)

    Brugger, Peter

    2008-12-01

    Mulder and colleagues [Mulder, T., Hochstenbach, J., Dijkstra, P. U., Geertzen, J. H. B. (2008). Born to adapt, but not in your dreams. Consciousness and Cognition, 17, 1266-1271.] report that a majority of amputees continue to experience a normally-limbed body during their night dreams. They interprete this observation as a failure of the body schema to adapt to the new body shape. The present note does not question this interpretation, but points to the already existing literature on the phenomenology of the phantom limb in dreams. A summary of published investigations is complemented by a note on phantom phenomena in the dreams of paraplegic patients and persons born without a limb. Integration of the available data allows the recommendation for prospective studies to consider dream content in more detail. For instance, "adaptation" to the loss of a limb can also manifest itself by seeing oneself surrounded by amputees. Such projective types of anosognosia ("transitivism") in nocturnal dreams should also be experimentally induced in normally-limbed individuals, and some relevant techniques are mentioned.

  7. Physical phantom of craniospinal hydrodynamics.

    Science.gov (United States)

    Bouzerar, R; Czosnyka, M; Czosnyka, Z; Balédent, Olivier

    2012-01-01

    Inside the craniospinal system, blood, and cerebrospinal fluid (CSF) interactions occurring through volume exchanges are still not well understood. We built a physical model of this global hydrodynamic system. The main objective was to study, in controlled conditions, CSF-blood interactions to better understand the phenomenon underlying pathogenesis of hydrocephalus. A structure representing the cranium is connected to the spinal channel. The cranium is divided into compartments mimicking anatomical regions such as ventricles or aqueduct cerebri. Resistive and compliant characteristics of blood and CSF compartments can be assessed or measured using pressure and flow sensors incorporated in the model. An arterial blood flow input is generated by a programmable pump. Flows and pressures inside the system are simultaneously recorded. Preliminary results show that the model can mimic venous and CSF flows in response to arterial pressure input. Pulse waveforms and volume flows were measured and confirmed that they partially replicated the data previously obtained with phase-contrast magnetic resonance imaging. The phantom shows that CSF oscillations directly result from arteriovenous flow, and intracranial pressure measurements show that the model obeys an exponential relationship between pressure and intracranial volume expansion. The phantom will be useful to investigate the hydrodynamic hypotheses underlying development of hydrocephalus.

  8. Synaesthesia in phantom limbs induced with mirrors.

    Science.gov (United States)

    Ramachandran, V S; Rogers-Ramachandran, D

    1996-04-22

    Although there is a vast clinical literature on phantom limbs, there have been no experimental studies on the effects of visual input on phantom sensations. We introduce an inexpensive new device--a 'virtual reality box'--to resurrect the phantom visually to study inter-sensory effects. A mirror is placed vertically on the table so that the mirror reflection of the patient's intact had is 'superimposed' on the felt position of the phantom. We used this procedure on ten patients and found the following results. 1. In six patients, when the normal hand was moved, so that the phantom was perceived to move in the mirror, it was also felt to move; i.e. kinesthetic sensations emerged in the phantom. In D.S. this effect occurred even though he had never experienced any movements in the phantom for ten years before we tested him. He found the return of sensations very enjoyable. 2. Repeated practice led to a permanent 'disappearance' of the phantom arm in patient D.S. and the hand became telescoped into the stump near the shoulder. 3. Using an optical trick, impossible postures--e.g. extreme hyperextension of the fingers--could be induced visually in the phantom. In one case this was felt as a transient 'painful tug' in the phantom. 4. Five patients experienced involuntary painful 'clenching spasms' in the phantom hand and in four of them the spasms were relieved when the mirror was used to facilitate 'opening' of the phantom hand; opening was not possible without the mirror. 5. In three patients, touching the normal hand evoked precisely localized touch sensations in the phantom. Interestingly, the referral was especially pronounced when the patients actually 'saw' their phantom being touched in the mirror. Indeed, in a fourth patient (R.L.) the referral occurred only if he saw his phantom being touched: a curious form of synaesthesia. These experiments lend themselves readily to imaging studies using PET and fMRI. Taken collectively, they suggest that there is a

  9. Synthetic breast phantoms from patient based eigenbreasts.

    Science.gov (United States)

    Sturgeon, Gregory M; Park, Subok; Segars, William Paul; Lo, Joseph Y

    2017-12-01

    The limited number of 3D patient-based breast phantoms available could be augmented by synthetic breast phantoms in order to facilitate virtual clinical trials (VCTs) using model observers for breast imaging optimization and evaluation. These synthetic breast phantoms were developed using Principal Component Analysis (PCA) to reduce the number of dimensions needed to describe a training set of images. PCA decomposed a training set of M breast CT volumes (with millions of voxels each) into an M-1-dimensional space of eigenvectors, which we call eigenbreasts. Each of the training breast phantoms was compactly represented by the mean image plus a weighted sum of eigenbreasts. The distribution of weights observed from training was then sampled to create new synthesized breast phantoms. The resulting synthesized breast phantoms demonstrated a high degree of realism, as supported by an observer study. Two out of three experienced physicist observers were unable to distinguish between the synthesized breast phantoms and the patient-based phantoms. The fibroglandular density and noise power law exponent of the synthesized breast phantoms agreed well with the training data. Our method extends our series of digital breast phantoms based on breast CT data, providing the capability to generate new, statistically varying ensembles consisting of tens of thousands of virtual subjects. This work represents an important step toward conducting future virtual trials for task-based assessment of breast imaging, where it is vital to have a large ensemble of realistic phantoms for statistical power as well as clinical relevance. © 2017 American Association of Physicists in Medicine.

  10. Alterations in Caveolin-1 Expression and Receptor-Operated Ca2+ Entry in the Aortas of Rats with Pulmonary Hypertension

    Directory of Open Access Journals (Sweden)

    Yun-Ping Mu

    2016-07-01

    Full Text Available Background/Aims: Alterations in intracellular Ca2+ concentration ([Ca2+]i underlie the pathogenesis of various cardiovascular diseases. Caveolin-1 (Cav-1 is the primary functional protein associated with caveolae, which are invaginations in the plasma membrane, and is a regulator of [Ca2+]i signaling. Caveolae and Cav-1 increase the activity of store-operated Ca2+ channels (SOCC in rat pulmonary arterial smooth muscle cells (PASMCs, and these enhancing effects were more pronounced in rats with pulmonary hypertension (PH. Classical transient receptor potential (TRPC proteins are highly expressed in vascular smooth muscle cells, and these proteins form functional receptor-operated Ca2+ channels (ROCC and SOCC in PASMCs. Previous studies suggested that functional and structural changes in aortas might occur during the pathological process of PH. Our data demonstrated that Cav-1 and TRPC were also abundant in the aorta smooth muscle cells (AoSMCs of PH rats. However, previous PH research primarily focused on Ca2+ channels in pulmonary arteries, but not functional changes in Ca2+ channels in aortas. The contribution of Cav-1 of AoSMCs to alterations of Ca2+ signaling in aortic functions during the pathological process of PH has not been fully characterized. Therefore, this study investigated alterations in Cav-1 expression and the relationship of these changes to Ca2+ channels in AoSMCs of PH rats. Methods: The present study examined physiological caveolae and Cav-1 expression and characterized the function of altered Cav-1 expression in rat aortas with PH. Results: The appearance of caveolae with Cav-1 expression increased significantly in the aortas of rats with PH, but TRPC1 and TRPC6 expression was not altered. In vitro experiments demonstrated that caveolae contributed to phenylephrine, endothelin-1, and 1-oleoyl-2-acetyl-sn-glycerol (OAG-induced aortic vasoreactivity, but KCl and cyclopiazonic acid had no effect, which suggests the vital

  11. MRI thermometry in phantoms by use of the proton resonance frequency shift method: application to interstitial laser thermotherapy

    OpenAIRE

    Olsrud, Johan; Wirestam, Ronnie; Brockstedt, Sara; Nilsson, Annika M K; Tranberg, Karl-Göran; Ståhlberg, Freddy; Persson, Bertil R

    1998-01-01

    In this work the temperature dependence of the proton resonance frequency was assessed in agarose gel with a high melting temperature (95 degrees C) and in porcine liver in vitro at temperatures relevant to thermotherapy (25-80 degrees C). Furthermore, an optically tissue-like agarose gel phantom was developed and evaluated for use in MRI. The phantom was used to visualize temperature distributions from a diffusing laser fibre by means of the proton resonance frequency shift method. An approx...

  12. Ischemic colitis complicating reconstruction of the abdominal aorta

    DEFF Research Database (Denmark)

    Schroeder, T V; Christoffersen, J K; Andersen, J

    1985-01-01

    A review of 23 patients with ischemic colitis after surgical treatment of the abdominal aorta disclosed a pathogenetic heterogeneous finding. Ligation of the inferior mesenteric artery, abolished collateral blood supply or nonocclusive low flow state, or both, was a common feature. An incidence...

  13. Coarctation of the Aorta, Known Yet Can Be Missed

    Directory of Open Access Journals (Sweden)

    Asim Al Balushi

    2013-05-01

    Full Text Available The clinical presentation of coarctation of aorta (CoA is well known; however, it is the most common congenital heart disease in the newborn period to be missed, with significant mortality and morbidity associated with missing the diagnosis. We report a 20-day-old newborn boy who presented with congestive heart failure and weak femoral pulses. Chest X-ray (CXR showed cardiomegaly and pulmonary edema and electrocardiography (ECG showed extreme right axis deviation and absent left ventricular forces in the left precordial leads. Based on these, clinical suspicion of coarctation of aorta was made and confirmed by echocardiography. After initial stabilization with prostaglandin E2 infusion, child underwent urgent coarctation of aorta repair with uneventful post-operative course. High index of suspicion for coarctation of aorta in a newborn with such presentation is required and urgent referral to Pediatric Cardiology and cardiac surgery center is mandatory to reduce the morbidity and mortality associated with missing the diagnosis.

  14. Classification and Functional Characterization of Vasa Vasorum-Associated Perivascular Progenitor Cells in Human Aorta

    Directory of Open Access Journals (Sweden)

    Marie Billaud

    2017-07-01

    Full Text Available In the microcirculation, pericytes are believed to function as mesenchymal stromal cells (MSCs. We hypothesized that the vasa vasorum harbor progenitor cells within the adventitia of human aorta. Pericytes, endothelial progenitor cells, and other cell subpopulations were detected among freshly isolated adventitial cells using flow cytometry. Purified cultured pericytes were enriched for the MSC markers CD105 and CD73 and depleted of the endothelial markers von Willebrand factor and CD31. Cultured pericytes were capable of smooth muscle lineage progression including inducible expression of smooth muscle myosin heavy chain, calponin, and α-smooth muscle actin, and adopted a spindle shape. Pericytes formed spheroids when cultured on Matrigel substrates and peripherally localized with branching endothelial cells in vitro. Our results indicate that the vasa vasorum form a progenitor cell niche distinct from other previously described progenitor populations in human adventitia. These findings could have important implications for understanding the complex pathophysiology of human aortic disease.

  15. Calcified aneurysm of the abdominal aorta 12 years after umbilical artery catheterization

    Energy Technology Data Exchange (ETDEWEB)

    Blondiaux, Eleonore; Miquel, Julie [Rouen University Hospital Charles Nicolle, Department of Radiology, Rouen (France); Thomas, Pascale; Watelet, Jacques [Rouen University Hospital Charles Nicolle, Department of Vascular Surgery, Rouen (France); Laloum, Denis [Caen University Hospital, Pediatric Intensive Care Unit, Department of Neonatal Medicine, Caen (France); Dacher, Jean-Nicolas [Rouen University Hospital Charles Nicolle, Department of Radiology, Rouen (France); UFR Medecine et Pharmacie, Laboratoire Quant-If, Rouen Cedex 01 (France)

    2008-02-15

    We report a 12-year-old boy who presented with abdominal pain and who was found to have an aneurysm of the abdominal aorta (AAA). The patient was born from a quadruplet pregnancy induced by in vitro fertilization. Postnatal transient respiratory distress required assisted ventilation that had been monitored by two consecutive umbilical arterial catheters (UAC). AAA is a rare condition in childhood. Infection and/or trauma are known to be the most frequent causes. Most of the reported cases have occurred in children in whom a UAC had been placed during the neonatal period. In this patient the delay between UAC placement and diagnosis was considerable. At the time of this report the patient had remained well during a follow-up of 8 years after treatment. (orig.)

  16. The neural basis of phantom limb pain.

    Science.gov (United States)

    Flor, Herta; Diers, Martin; Andoh, Jamila

    2013-07-01

    A recent study suggests that brain changes in amputees may be pain-induced, questioning maladaptive plasticity as a neural basis of phantom pain. These findings add valuable information on cortical reorganization after amputation. We suggest further lines of research to clarify the mechanisms that underlie phantom pain. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Resin phantoms as skin simulating layers

    CSIR Research Space (South Africa)

    Karsten, AE

    2011-07-01

    Full Text Available on the efficiency of Photodynamic Therapy (PDT) treatment. Two resin based solid phantoms were prepared to simulate two different skin types. Cells were prepared and PDT treatment were done on cells with and without the phantoms, by keeping the total dose delivered...

  18. File list: NoD.CDV.20.AllAg.Aorta [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.CDV.20.AllAg.Aorta hg19 No description Cardiovascular Aorta SRX134730,SRX134748...,SRX190787,SRX136957,SRX347265,SRX213926,SRX136951,SRX342280,SRX347269,SRX347278,SRX213918 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.CDV.20.AllAg.Aorta.bed ...

  19. File list: NoD.CDV.10.AllAg.Aorta [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.CDV.10.AllAg.Aorta hg19 No description Cardiovascular Aorta SRX134730,SRX347278...,SRX347265,SRX136957,SRX134748,SRX190787,SRX342280,SRX213926,SRX136951,SRX347269,SRX213918 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.CDV.10.AllAg.Aorta.bed ...

  20. A computational model unifies apparently contradictory findings concerning phantom pain

    National Research Council Canada - National Science Library

    Boström, Kim J; de Lussanet, Marc H E; Weiss, Thomas; Puta, Christian; Wagner, Heiko

    2014-01-01

    ...) as a cause of phantom pain. However, it was recently found that BOLD activity during voluntary movements of the phantom positively correlates with phantom pain rating, giving rise to a model of persistent representation...

  1. [A dynamic phantom for computer tomography].

    Science.gov (United States)

    Nüsslin, F

    1981-06-01

    A phantom is described which has been developed for investigating factors depending on the scanner itself and on the scanned object which potentially influence the kind and the extent of motion artefacts on the CT-image. Additionally, the phantom may be applied to qualify assurance measurements in computer tomography. A cylindrical insert mounted on a motor driven axis is fitted centrally in a cylindrical block machined from lucite. Two interchangeable inserts are available, one containing test objects made of various materials, and another one containing small vessels which can be filled with test solutions. The insert positioned in the phantom can rotate either continuously or with the direction of motion being altered periodically. Speed, frequency and arc can be varied within wide limits. Examples demonstrating the static and the dynamic mode of the phantom are shown. By means of the dynamic phantom it is quite easy to directly determine the scan-time of a Computer tomograph.

  2. The risks of aorta impingement from pedicle screw may increase due to aorta movement during posterior instrumentation in Lenke 5C curve: a computed tomography study.

    Science.gov (United States)

    Chen, Ling; Xu, Leilei; Qiu, Yong; Qiao, Jun; Wang, Fei; Liu, Zhen; Shi, Benglong; Qian, Bang-ping; Zhu, Zezhang

    2015-07-01

    To investigate the aorta movement following correction surgery for patients with thoracolumbar/lumbar scoliosis and to determine the subsequent risk of the aorta impingement for pedicle screw (PS) misplacement. Thirty-six AIS patients with a main thoracolumbar or lumbar curve were included in this study. According to the direction of the main curve, the patients were divided into Group R and Group L, with Group R comprising 16 patients with a right-sided curve and Group L comprising 20 patients with a left-sided curve. All patients underwent CT scans of the lower thoracic and lumbar spine before and after surgery. To identify the relative positions of the aorta to vertebral body, several parameters were measured from the CT images of the middle transverse planes of vertebrae from T11 to L4, including aorta-vertebra angle (α), vertebral rotation angle (β), left safety distance (LSD) and right safety distance (RSD). The risk of the aorta impingement from T11 to L4 was calculated. An intragroup comparison regarding the position of the aorta relative to the vertebral body before and after correction surgery was performed accordingly. After surgery, the aorta moved toward the vertebral body among all levels in both groups. Compared with that in Group L, the aorta in Group R was significantly closer to the entry point at all levels, especially at T11. Before surgery, the aorta in Group R was at a high risk of impingement from left PS placement regardless of the diameters of the simulated screws. While in Group L, the risk of aorta impingement was mainly caused by the right placement of 45 mm PS. After surgery, both groups had an increased risk of aorta impingement from PS insertion, especially at T11. The risk of aorta impingement from PS placement was significantly higher in Group R than in Group L. The risk of aorta impingement increased as the aorta shifted leftward after correction surgery, especially in right-sided Lenke 5C curve. Thus, preoperative risk

  3. Intravascular enhancement with identical iodine delivery rate using different iodine contrast media in a circulation phantom.

    Science.gov (United States)

    Mihl, Casper; Wildberger, Joachim E; Jurencak, Tomas; Yanniello, Michael J; Nijssen, Estelle C; Kalafut, John F; Nalbantov, Georgi; Mühlenbruch, Georg; Behrendt, Florian F; Das, Marco

    2013-11-01

    Both iodine delivery rate (IDR) and iodine concentration are decisive factors for vascular enhancement in computed tomographic angiography. It is unclear, however, whether the use of high-iodine concentration contrast media is beneficial to lower iodine concentrations when IDR is kept identical. This study evaluates the effect of using different iodine concentrations on intravascular attenuation in a circulation phantom while maintaining a constant IDR. A circulation phantom with a low-pressure venous compartment and a high-pressure arterial compartment simulating physiological circulation parameters was used (heart rate, 60 beats per minute; stroke volume, 60 mL; blood pressure, 120/80 mm Hg). Maintaining a constant IDR (2.0 g/s) and a constant total iodine load (20 g), prewarmed (37°C) contrast media with differing iodine concentrations (240-400 mg/mL) were injected into the phantom using a double-headed power injector. Serial computed tomographic scans at the level of the ascending aorta (AA), the descending aorta (DA), and the left main coronary artery (LM) were obtained. Total amount of contrast volume (milliliters), iodine delivery (grams of iodine), peak flow rate (milliliter per second), and intravascular pressure (pounds per square inch) were monitored using a dedicated data acquisition program. Attenuation values in the AA, the DA, and the LM were constantly measured (Hounsfield unit [HU]). In addition, time-enhancement curves, aortic peak enhancement, and time to peak were determined. All contrast injection protocols resulted in similar attenuation values: the AA (516 [11] to 531 [37] HU), the DA (514 [17] to 531 [32] HU), and the LM (490 [10] to 507 [17] HU). No significant differences were found between the AA, the DA, and the LM for either peak enhancement (all P > 0.05) or mean time to peak (AA, 19.4 [0.58] to 20.1 [1.05] seconds; DA, 21.1 [1.0] to 21.4 [1.15] seconds; LM, 19.8 [0.58] to 20.1 [1.05] seconds). This phantom study demonstrates that

  4. Galactic dark matter in the phantom field

    Science.gov (United States)

    Li, Ming-Hsun; Yang, Kwei-Chou

    2012-12-01

    We investigate the possibility that the galactic dark matter exists in a scenario where the phantom field is responsible for the dark energy. We obtain the statically and spherically approximate solution for this kind of galaxy system with a supermassive black hole at its center. The solution of the metric functions is satisfied with gtt=-grr-1. Constrained by the observation of the rotational stars moving in circular orbits with nearly constant tangential speed in a spiral galaxy, the background of the phantom field which is spatially inhomogeneous has an exponential potential. To avoid the well-known quantum instability of the vacuum at high frequencies, the phantom field defined in an effective theory is valid only at low energies. Under this assumption, we further investigate the following properties. The absorption cross section of the low-energy S-wave excitations of the phantom field into the central black hole is shown to be the horizontal area of the central black hole. Because the infalling phantom particles have a total negative energy, the accretion of the phantom energy is related to the decrease of the black hole mass, which is estimated to be much less than a solar mass in the lifetime of the Universe. Using a simple model with the cold dark matter very weakly coupled to the “low-frequency” phantom particles that are generated from the background, we show that these two densities can be quasistable in the galaxy.

  5. A phantom design for validating colonoscopy tracking

    Science.gov (United States)

    Liu, Jianfei; Subramanian, Kalpathi R.; Yoo, Terry S.

    2012-03-01

    Phantom experiments are useful and frequently used in validating algorithms or techniques in applications where it is difficult or impossible to generate accurate ground-truth. In this work we present a phantom design and experiments to validate our colonoscopy tracking algorithms, that serve to keep both virtual colonoscopy and optical colonoscopy images aligned (in location and orientation). We describe the construction of two phantoms, capable of respectively moving along a straight and a curved path. The phantoms are motorized so as to be able to move at a near constant speed. Experiments were performed at three speeds: 10, 15 and 20mm/sec, to simulate motion velocities during colonoscopy procedures. The average velocity error was within 3mm/sec in both straight and curved phantoms. Displacement error was within 7mm over a total distance of 288mm in the straight phantom, and less than 7mm over 287mm in the curved phantom. Multiple trials were performed of each experiment(and their errors averaged) to ensure repeatability.

  6. The reference phantoms: voxel vs polygon.

    Science.gov (United States)

    Kim, C H; Yeom, Y S; Nguyen, T T; Wang, Z J; Kim, H S; Han, M C; Lee, J K; Zankl, M; Petoussi-Henss, N; Bolch, W E; Lee, C; Chung, B S

    2016-06-01

    The International Commission on Radiological Protection (ICRP) reference male and female adult phantoms, described in Publication 110, are voxel phantoms based on whole-body computed tomography scans of a male and a female patient, respectively. The voxel in-plane resolution and the slice thickness, of the order of a few millimetres, are insufficient for proper segmentation of smaller tissues such as the lens of the eye, the skin, and the walls of some organs. The calculated doses for these tissues therefore present some limitations, particularly for weakly penetrating radiation. Similarly, the Publication 110 phantoms cannot represent 8-40-µm-thick target regions in respiratory or alimentary tract organs. Separate stylised models have been used to represent these tissues for calculation of the ICRP reference dose coefficients (DCs). ICRP Committee 2 recently initiated a research project, the ultimate goal of which is to convert the Publication 110 phantoms to a high-quality polygon-mesh (PM) format, including all source and target regions, even those of the 8-40-µm-thick alimentary and respiratory tract organs. It is expected that the converted phantoms would lead to the same or very similar DCs as the Publication 110 reference phantoms for penetrating radiation and, at the same time, provide more accurate DCs for weakly penetrating radiation and small tissues. Additionally, the reference phantoms in the PM format would be easily deformable and, as such, could serve as a starting point to create phantoms of various postures for use, for example, in accidental dose calculations. This paper will discuss the current progress of the phantom conversion project and its significance for ICRP DC calculations. © The International Society for Prosthetics and Orthotics.

  7. Ang II enhances noradrenaline release from sympathetic nerve endings thus contributing to the up-regulation of metalloprotease-2 in aortic dissection patients' aorta wall.

    Directory of Open Access Journals (Sweden)

    Zhipeng Hu

    Full Text Available OBJECT: To test the hypothesis that angiotensin II (Ang II could enhance noradrenaline (NA release from sympathetic nerve endings of the aorta thus contributing to the up-regulation of matrix metalloproteinase 2 (MMP-2 during the formation of aortic dissection (AD. METHODS: Ang II, NA, MMP-2, MMP-9 of the aorta sample obtained during operation from aortic dissection patients were detected by High Performance Liquid Chromatography and ELISA and compared with controls. Isotope labelling method was used to test the impact of exogenous Ang II and noradrenaline on the NA release and MMP-2, MMP-9 expression on Sprague Dawley (SD rat aorta rings in vitro. Two kidneys, one clip, models were replicated for further check of that impact in SD rats in vivo. RESULTS: The concentration of Ang II, MMP-2, 9 was increased and NA concentration was decreased in aorta samples from AD patients. Exogenous Ang II enhanced while exogenous NA restrained NA release from aortic sympathetic endings. The Ang II stimulated NA release and the following MMP-2 up-regulation could be weakened by Losartan and chemical sympathectomy. Beta blocker did not influence NA release but down-regulated MMP-2. Long term in vivo experiments confirmed that Ang II could enhance NA release and up-regulate MMP-2. CONCLUSIONS: AD is initiated by MMP-2 overexpression as a result of increased NA release from sympathetic nervous endings in response to Ang II. This indicates an interaction of RAS and SAS during the formation of AD.

  8. Mechanics, Mechanobiology, and Modeling of Human Abdominal Aorta and Aneurysms

    Science.gov (United States)

    Humphrey, J.D.; Holzapfel, G.A.

    2011-01-01

    Biomechanical factors play fundamental roles in the natural history of abdominal aortic aneurysms (AAAs) and their responses to treatment. Advances during the past two decades have increased our understanding of the mechanics and biology of the human abdominal aorta and AAAs, yet there remains a pressing need for considerable new data and resulting patient-specific computational models that can better describe the current status of a lesion and better predict the evolution of lesion geometry, composition, and material properties and thereby improve interventional planning. In this paper, we briefly review data on the structure and function of the human abdominal aorta and aneurysmal wall, past models of the mechanics, and recent growth and remodeling models. We conclude by identifying open problems that we hope will motivate studies to improve our computational modeling and thus general understanding of AAAs. PMID:22189249

  9. Coarctation of the aorta associated with Dandy–Walker variant

    Science.gov (United States)

    Zhou, Li; Lui, George K.; Shenoy, Rajesh; Taub, Cynthia C.

    2013-01-01

    This article reports a rare case of coarctation of the aorta associated with Dandy–Walker variant in a 17-year-old girl. Differential diagnoses of coarctation of the aorta and Dandy–Walker variant are extensively discussed. In addition, standard surgical treatment of coarctation as well as new approaches such as endovascular stenting are described in detail to provide therapeutic insights into her management. Although surgical or endovascular repair of coarctation results in significant improvement of systemic hypertension and is associated with better survival, cardiovascular complications are still very common. Thus, long-term follow-up after repair is required, and high-quality imaging studies such as echocardiography, CT and MRI are warranted. PMID:24396258

  10. Coarctation of the aorta associated with Dandy-Walker variant.

    Science.gov (United States)

    Zhou, Li; Lui, George K; Shenoy, Rajesh; Taub, Cynthia C

    2013-09-01

    This article reports a rare case of coarctation of the aorta associated with Dandy-Walker variant in a 17-year-old girl. Differential diagnoses of coarctation of the aorta and Dandy-Walker variant are extensively discussed. In addition, standard surgical treatment of coarctation as well as new approaches such as endovascular stenting are described in detail to provide therapeutic insights into her management. Although surgical or endovascular repair of coarctation results in significant improvement of systemic hypertension and is associated with better survival, cardiovascular complications are still very common. Thus, long-term follow-up after repair is required, and high-quality imaging studies such as echocardiography, CT and MRI are warranted.

  11. Descending thoracic aorta dissection associated with esophageal carcinoma

    Directory of Open Access Journals (Sweden)

    Kaushik Saha

    2013-01-01

    Full Text Available The association of aortic dissection with a malignancy is a rare finding and previous reports are usually those of primary aortic sarcomas. A 45-year-old male presented to us with chest pain and dysphagia for 1 month with a background history of obstructive airway disease and uncontrolled hypertension. In this report we present a case of typical descending aorta dissection with associated esophageal carcinoma.

  12. Panel Discussion: Session IV—Descending and Thoracoabdominal Aorta

    National Research Council Canada - National Science Library

    Spielvogel, David; Cambria, Richard P; Coselli, Joseph S; Griepp, Randall B; Khoynezhad, Ali; Mitchell, R. Scott; Plestis, Konstadinos A; Schepens, Marc; Schurink, Geert Willem; Svensson, Lars G; Wheatley, Grayson H

    2007-01-01

    ... the aortic arch. In other words, you do what we call a slash and grab: open the aorta, grab the graft, and clamp it. So that is what you want to have enough length for. On the other hand, for a second stage elephant trunk stent with an endograft, you don’t want it too long, because, as I pointed out, if it is too long you have got much more risk of it ...

  13. Toward Improving the Fetal Diagnosis of Coarctation of the Aorta.

    Science.gov (United States)

    Beattie, Meaghan; Peyvandi, Shabnam; Ganesan, Suguna; Moon-Grady, Anita

    2017-02-01

    Coarctation of the aorta (CoA) is the most common ductal-dependent lesion missed on neonatal exam screening. Prenatal diagnosis of CoA improves outcomes through early initiation of prostaglandin. Fetal echocardiographic parameters including 2D and Doppler findings have been studied as predictive measures for fetal diagnosis of CoA, but diagnosis rates remain variable. A comprehensive set of predictor variables was applied to fetuses suspected of CoA to analyze which parameters were associated with postnatal CoA. UCSF Fetal Cardiovascular Program databases were queried for fetuses suspected of CoA (2008-2014). Retrospective measurements of aorta/pulmonary artery ratio (AoPA), LV/RV ratio, ascending aorta Z-score (AscAo), isthmus Z-score, isthmus/duct ratio (I/D), posterior "shelf" of descending aorta, and diastolic flow persistence at the isthmus were recorded. ROC analysis identified the parameters most predictive of postnatal CoA. Among 97 fetuses with probable CoA, 62 had complete follow-up. Of these fetuses, 45 (72.5%) had postnatal confirmation of CoA and 17 did not have CoA. The parameters most predictive of postnatal CoA included AscAo, isthmus Z-score, and I/D, with respective AUC of 0.80, 0.89, and 0.90. Diastolic flow persistence was seen more often in fetuses with postnatal CoA, but did not reach statistical significance. Combining 2D and Doppler criteria (AoPA AoPA ratio are useful predictors of CoA. Doppler information was most helpful when 2D imaging was equivocal; its addition resulted in high sensitivity in an enriched cohort referred for fetal echocardiography.

  14. CT and MR imaging of the thoracic aorta

    Directory of Open Access Journals (Sweden)

    Di Cesare Ernesto

    2016-01-01

    Full Text Available At present time, both CT and MRI are valuable techniques in the study of the thoracic aorta. Nowadays, CT represents the most widely employed technique for the study of the thoracic aorta. The new generation CTs show sensitivities up to 100% and specificities of 98-99%. Sixteen and wider row detectors provide isotropic pixels, mandatory for the ineludible longitudinal reconstruction. The main limits are related to the X-ray dose expoure and the use of iodinated contrast media. MRI has great potential in the study of the thoracic aorta. Nevertheless, if compared to CT, acquisition times remain longer and movement artifact susceptibility higher. The main MRI disadvantages are claustrophobia, presence of ferromagnetic implants, pacemakers, longer acquisition times with respect to CT, inability to use contrast media in cases of renal insufficiency, lower spatial resolution and less availability than CT. CT is preferred in the acute aortic disease. Nevertheless, since it requires iodinated contrast media and X-ray exposure, it may be adequately replaced by MRI in the follow up of aortic diseases. The main limitation of MRI, however, is related to the scarce visibility of stents and calcifications.

  15. Medical image of the week: coral reef aorta

    Directory of Open Access Journals (Sweden)

    Eberson L

    2017-07-01

    Full Text Available No abstract available. Article truncated at 150 words. A 52-year-old woman with no past medical history presented to the emergency department with signs and symptoms concerning for pneumonia. Chest x-ray showed incidental findings of a calcified aortic mass. Subsequently, a follow up computed tomography scan (CT was obtained which showed coral reef aorta (Figure 1. On physical examination, vital signs were only significant for mildly elevated blood pressure to 146/62 mmHg. She also had normal and equal pulses and pressures throughout all 4 extremities. In retrospect, patient had complaints of bilateral lower extremity claudication on strenuous exercise. Coral reef aorta, a rare condition that was first described in 1984 by Qvarfordt et al. (1 is characterized by an eccentric, heavily calcified polypoid lesion and stenosis of the juxtarenal and suprarenal aorta. The rock-hard, irregular, gritty, whitish surface of the calcification strongly resembled a coral reef. The most common presentation is severe hypertension and intermittent claudication. Magnetic resonance angiogram …

  16. Can neural blocks prevent phantom limb pain?

    Science.gov (United States)

    Borghi, Battista; D'Addabbo, Marco; Borghi, Raffaele

    2014-07-01

    Phantom limb syndrome (PLS) is a syndrome including stump pain, phantom limb pain and not-painful phantom sensations, which involves a large part of amputee patients and often has devastating effects on their quality of life. The efficacy of standard therapies is very poor. Nerve blocks have been investigated for the treatment and prevention of PLS. Epidural and peripheral blocks limited to the first three postamputation days can only reduce acute pain but cannot prevent the later development of PLS. Recent studies have shown that ambulatory prolonged peripheral nerve block (up to 30 days postamputation) may represent a new possible option to treat phantom pain and prevent the development of PLS and chronic pain.

  17. Phantom perception: voluntary and involuntary nonretinal vision.

    Science.gov (United States)

    Pearson, Joel; Westbrook, Fred

    2015-05-01

    Hallucinations, mental imagery, synesthesia, perceptual filling-in, and many illusions are conscious visual experiences without a corresponding retinal stimulus: what we call 'phantom perception'. Such percepts show that our experience of the world is not solely determined by direct sensory input. Some phantom percepts are voluntary, whereas others are involuntarily, occurring automatically. Here, by way of review, we compare and contrast these two types of phantom perception and their neural representations. We propose a dichotomous framework for phantom vision, analogous to the subtypes of attention: endogenous and exogenous. This framework unifies findings from different fields and species, providing a guide to study the constructive nature of conscious sensory perception. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The effect of phantom parent groups on genetic trend estimation ...

    African Journals Online (AJOL)

    Bias in the estimation of trend was reduced when phantom parent groups were taken into account. The 109 385 base animals were replaced by 64 phantom parent groups. Phantom parent groups were constructed by combining year of birth, country of birth and selection intensity of the phantom parents. In recent years ...

  19. Development of realistic physical breast phantoms matched to virtual breast phantoms based on human subject data.

    Science.gov (United States)

    Kiarashi, Nooshin; Nolte, Adam C; Sturgeon, Gregory M; Segars, William P; Ghate, Sujata V; Nolte, Loren W; Samei, Ehsan; Lo, Joseph Y

    2015-07-01

    Physical phantoms are essential for the development, optimization, and evaluation of x-ray breast imaging systems. Recognizing the major effect of anatomy on image quality and clinical performance, such phantoms should ideally reflect the three-dimensional structure of the human breast. Currently, there is no commercially available three-dimensional physical breast phantom that is anthropomorphic. The authors present the development of a new suite of physical breast phantoms based on human data. The phantoms were designed to match the extended cardiac-torso virtual breast phantoms that were based on dedicated breast computed tomography images of human subjects. The phantoms were fabricated by high-resolution multimaterial additive manufacturing (3D printing) technology. The glandular equivalency of the photopolymer materials was measured relative to breast tissue-equivalent plastic materials. Based on the current state-of-the-art in the technology and available materials, two variations were fabricated. The first was a dual-material phantom, the Doublet. Fibroglandular tissue and skin were represented by the most radiographically dense material available; adipose tissue was represented by the least radiographically dense material. The second variation, the Singlet, was fabricated with a single material to represent fibroglandular tissue and skin. It was subsequently filled with adipose-equivalent materials including oil, beeswax, and permanent urethane-based polymer. Simulated microcalcification clusters were further included in the phantoms via crushed eggshells. The phantoms were imaged and characterized visually and quantitatively. The mammographic projections and tomosynthesis reconstructed images of the fabricated phantoms yielded realistic breast background. The mammograms of the phantoms demonstrated close correlation with simulated mammographic projection images of the corresponding virtual phantoms. Furthermore, power-law descriptions of the phantom images

  20. Acupuncture treatment of phantom limb pain and phantom limb sensation in a primary care setting.

    Science.gov (United States)

    Davies, Arwel

    2013-03-01

    A 45-year-old man presented with phantom limb pain and phantom limb sensation 12 weeks after an above-elbow amputation of his right arm. He underwent seven sessions of acupuncture at weekly intervals carried out by his general practitioner on his intact left arm, with complete relief of the phantom limb pain and considerable improvement of the phantom limb sensation of his right arm. This case demonstrates the possible benefits from the use of short acupuncture sessions for a potentially chronic condition undertaken within the constraints of a busy general medical practice.

  1. Development of realistic physical breast phantoms matched to virtual breast phantoms based on human subject data

    Energy Technology Data Exchange (ETDEWEB)

    Kiarashi, Nooshin [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Nolte, Adam C. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Sturgeon, Gregory M.; Ghate, Sujata V. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Segars, William P. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27708 (United States); Nolte, Loren W. [Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27708 (United States); Department of Physics, Duke University, Durham, North Carolina 27708 (United States); and others

    2015-07-15

    Purpose: Physical phantoms are essential for the development, optimization, and evaluation of x-ray breast imaging systems. Recognizing the major effect of anatomy on image quality and clinical performance, such phantoms should ideally reflect the three-dimensional structure of the human breast. Currently, there is no commercially available three-dimensional physical breast phantom that is anthropomorphic. The authors present the development of a new suite of physical breast phantoms based on human data. Methods: The phantoms were designed to match the extended cardiac-torso virtual breast phantoms that were based on dedicated breast computed tomography images of human subjects. The phantoms were fabricated by high-resolution multimaterial additive manufacturing (3D printing) technology. The glandular equivalency of the photopolymer materials was measured relative to breast tissue-equivalent plastic materials. Based on the current state-of-the-art in the technology and available materials, two variations were fabricated. The first was a dual-material phantom, the Doublet. Fibroglandular tissue and skin were represented by the most radiographically dense material available; adipose tissue was represented by the least radiographically dense material. The second variation, the Singlet, was fabricated with a single material to represent fibroglandular tissue and skin. It was subsequently filled with adipose-equivalent materials including oil, beeswax, and permanent urethane-based polymer. Simulated microcalcification clusters were further included in the phantoms via crushed eggshells. The phantoms were imaged and characterized visually and quantitatively. Results: The mammographic projections and tomosynthesis reconstructed images of the fabricated phantoms yielded realistic breast background. The mammograms of the phantoms demonstrated close correlation with simulated mammographic projection images of the corresponding virtual phantoms. Furthermore, power

  2. Conversion of ICRP male reference phantom to polygon-surface phantom.

    Science.gov (United States)

    Yeom, Yeon Soo; Han, Min Cheol; Kim, Chan Hyeong; Jeong, Jong Hwi

    2013-10-07

    The International Commission on Radiological Protection (ICRP) reference phantoms, developed based on computed tomography images of human bodies, provide much more realism of human anatomy than the previously used MIRD5 (Medical Internal Radiation Dose) mathematical phantoms. It has been, however, realized that the ICRP reference phantoms have some critical limitations showing a considerable amount of holes for the skin and wall organs mainly due to the nature of voxels of which the phantoms are made, especially due to their low voxel resolutions. To address this problem, we are planning to develop the polygon-surface version of ICRP reference phantoms by directly converting the ICRP reference phantoms (voxel phantoms) to polygon-surface phantoms. The objective of this preliminary study is to see if it is indeed possible to construct the high-quality polygon-surface phantoms based on the ICRP reference phantoms maintaining identical organ morphology and also to identify any potential issues, and technologies to address these issues, in advance. For this purpose, in the present study, the ICRP reference male phantom was roughly converted to a polygon-surface phantom. Then, the constructed phantom was implemented in Geant4, Monte Carlo particle transport code, for dose calculations, and the calculated dose values were compared with those of the original ICRP reference phantom to see how much the calculated dose values are sensitive to the accuracy of the conversion process. The results of the present study show that it is certainly possible to convert the ICRP reference phantoms to surface phantoms with enough accuracy. In spite of using relatively less resources (polygon-surface phantom with the organ masses perfectly matching the ICRP reference values. The analysis of the calculated dose values also implies that the dose values are indeed not very sensitive to the detailed morphology of the organ models in the phantom for highly penetrating radiations such as

  3. Conversion of ICRP male reference phantom to polygon-surface phantom

    Science.gov (United States)

    Yeom, Yeon Soo; Han, Min Cheol; Kim, Chan Hyeong; Jeong, Jong Hwi

    2013-10-01

    The International Commission on Radiological Protection (ICRP) reference phantoms, developed based on computed tomography images of human bodies, provide much more realism of human anatomy than the previously used MIRD5 (Medical Internal Radiation Dose) mathematical phantoms. It has been, however, realized that the ICRP reference phantoms have some critical limitations showing a considerable amount of holes for the skin and wall organs mainly due to the nature of voxels of which the phantoms are made, especially due to their low voxel resolutions. To address this problem, we are planning to develop the polygon-surface version of ICRP reference phantoms by directly converting the ICRP reference phantoms (voxel phantoms) to polygon-surface phantoms. The objective of this preliminary study is to see if it is indeed possible to construct the high-quality polygon-surface phantoms based on the ICRP reference phantoms maintaining identical organ morphology and also to identify any potential issues, and technologies to address these issues, in advance. For this purpose, in the present study, the ICRP reference male phantom was roughly converted to a polygon-surface phantom. Then, the constructed phantom was implemented in Geant4, Monte Carlo particle transport code, for dose calculations, and the calculated dose values were compared with those of the original ICRP reference phantom to see how much the calculated dose values are sensitive to the accuracy of the conversion process. The results of the present study show that it is certainly possible to convert the ICRP reference phantoms to surface phantoms with enough accuracy. In spite of using relatively less resources (<2 man-months), we were able to construct the polygon-surface phantom with the organ masses perfectly matching the ICRP reference values. The analysis of the calculated dose values also implies that the dose values are indeed not very sensitive to the detailed morphology of the organ models in the phantom

  4. Mirror Therapy for Phantom Limb Pain

    OpenAIRE

    Kim, Sae Young; Kim, Yun Young

    2012-01-01

    Phantom limb pain is a painful sensation that is perceived in a body part that no longer exists. To control this pain, many methods have been used such as medication, physical treatment, nerve block, neuromodulation, surgical treatment and mirror therapy. However, until now, there effects have been uncertain. We report the successful reduction of phantom limb pain using mirror therapy when other treatments initially failed to control the pain.

  5. Cyclic universe due to phantom and quintessence

    OpenAIRE

    Gao, Changjun; Lu, Youjun; Shen, You-Gen

    2014-01-01

    We explore a cyclic universe due to phantom and quintessence fields. We find that, in every cycle of the evolution of the universe, the phantom dominates the cosmic early history and quintessence dominates the cosmic far future. In this model of universe, there are infinite cycles of expansion and contraction. Different from the inflationary universe, the corresponding cosmic space-time is geodesically complete and quantum stable. But similar to the Cyclic Model, the flatness problem, the hor...

  6. The menacing phantom: what pulls the trigger?

    Science.gov (United States)

    Giummarra, Melita J; Georgiou-Karistianis, Nellie; Nicholls, Michael E R; Gibson, Stephen J; Chou, Michael; Bradshaw, John L

    2011-08-01

    Phantom phenomena are frequent following amputation, but how this often painful experience is modified or triggered by spontaneous events or sensations often puzzles amputees and clinicians alike. We explored triggers of phantom phenomena in a heterogeneous sample of 264 upper and lower limb adult amputees with phantom sensations. Participants completed a structured questionnaire to determine the prevalence and nature of the triggers of phantom phenomena. The four categories of triggers identified include: (a) a quarter of participants experiencing psychological, emotional or autonomic triggers; (b) half experiencing behavioral triggers, "forgetting" the limb's absence and attempting to use the phantom; (c) one-fifth experiencing weather-induced triggers; and (d) one-third experiencing sensations referred from parts of the body. Upper limb amputees; and were more likely to experience weather-induced phantom phenomena than lower limb amputees; and upper and lower limb amputees were equally likely to experience referred sensations from the genitals, contradicting the homuncular remapping hypothesis. Traumatic amputees were more likely to report emotional triggers. Further, while those with emotional triggers exhibited poorer acceptance of the limitations of amputation, they were more likely to employ adaptive coping mechanisms. Finally, habitual "forgetting" behaviors were most common soon after amputation, whereas other more adaptive schemata (e.g., self-defense) were equally likely to be performed at any time following amputation. Various likely inter-related mechanisms are discussed in relation to phantom triggers. Ultimately, optimizing stump and neuroma management, as well as restoring function of central networks for pain, limb movement, and amputation-related memories, should help manage spontaneously triggered phantom phenomena. Copyright © 2011 European Federation of International Association for the Study of Pain Chapters. All rights reserved.

  7. Phantom Limb Pain: Mechanisms and Treatment Approaches

    Science.gov (United States)

    Subedi, Bishnu; Grossberg, George T.

    2011-01-01

    The vast amount of research over the past decades has significantly added to our knowledge of phantom limb pain. Multiple factors including site of amputation or presence of preamputation pain have been found to have a positive correlation with the development of phantom limb pain. The paradigms of proposed mechanisms have shifted over the past years from the psychogenic theory to peripheral and central neural changes involving cortical reorganization. More recently, the role of mirror neurons in the brain has been proposed in the generation of phantom pain. A wide variety of treatment approaches have been employed, but mechanism-based specific treatment guidelines are yet to evolve. Phantom limb pain is considered a neuropathic pain, and most treatment recommendations are based on recommendations for neuropathic pain syndromes. Mirror therapy, a relatively recently proposed therapy for phantom limb pain, has mixed results in randomized controlled trials. Most successful treatment outcomes include multidisciplinary measures. This paper attempts to review and summarize recent research relative to the proposed mechanisms of and treatments for phantom limb pain. PMID:22110933

  8. Phantom Limb Pain: Mechanisms and Treatment Approaches

    Directory of Open Access Journals (Sweden)

    Bishnu Subedi

    2011-01-01

    Full Text Available The vast amount of research over the past decades has significantly added to our knowledge of phantom limb pain. Multiple factors including site of amputation or presence of preamputation pain have been found to have a positive correlation with the development of phantom limb pain. The paradigms of proposed mechanisms have shifted over the past years from the psychogenic theory to peripheral and central neural changes involving cortical reorganization. More recently, the role of mirror neurons in the brain has been proposed in the generation of phantom pain. A wide variety of treatment approaches have been employed, but mechanism-based specific treatment guidelines are yet to evolve. Phantom limb pain is considered a neuropathic pain, and most treatment recommendations are based on recommendations for neuropathic pain syndromes. Mirror therapy, a relatively recently proposed therapy for phantom limb pain, has mixed results in randomized controlled trials. Most successful treatment outcomes include multidisciplinary measures. This paper attempts to review and summarize recent research relative to the proposed mechanisms of and treatments for phantom limb pain.

  9. The GSF family of voxel phantoms.

    Science.gov (United States)

    Petoussi-Henss, Nina; Zanki, Maria; Fill, Ute; Regulla, Dieter

    2002-01-07

    Voxel phantoms are human models based on computed tomographic or magnetic resonance images obtained from high-resolution scans of a single individual. They consist of a huge number of volume elements (voxels) and are at the moment the most precise representation of the human anatomy. The purpose of this paper is to introduce the GSF voxel phantoms, with emphasis on the new ones and highlight their characteristics and limitations. The GSF voxel family includes at the moment two paediatric and five adult phantoms of both sexes, different ages and stature and several others are under construction. Two phantoms made of physical calibration phantoms are also available to be used for validation purposes. The GSF voxel phantoms tend to cover persons of individual anatomy and were developed to be used for numerical dosimetry of radiation transport but other applications are also possible. Examples of applications in patient dosimetry in diagnostic radiology and in nuclear medicine as well as for whole-body irradiations from idealized external exposures are given and discussed.

  10. The GSF family of voxel phantoms

    Science.gov (United States)

    Petoussi-Henss, Nina; Zankl, Maria; Fill, Ute; Regulla, Dieter

    2002-01-01

    Voxel phantoms are human models based on computed tomographic or magnetic resonance images obtained from high-resolution scans of a single individual. They consist of a huge number of volume elements (voxels) and are at the moment the most precise representation of the human anatomy. The purpose of this paper is to introduce the GSF voxel phantoms, with emphasis on the new ones and highlight their characteristics and limitations. The GSF voxel family includes at the moment two paediatric and five adult phantoms of both sexes, different ages and stature and several others are under construction. Two phantoms made of physical calibration phantoms are also available to be used for validation purposes. The GSF voxel phantoms tend to cover persons of individual anatomy and were developed to be used for numerical dosimetry of radiation transport but other applications are also possible. Examples of applications in patient dosimetry in diagnostic radiology and in nuclear medicine as well as for whole-body irradiations from idealized external exposures are given and discussed.

  11. A nonlinear elasticity phantom containing spherical inclusions

    Science.gov (United States)

    Pavan, Theo Z.; Madsen, Ernest L.; Frank, Gary R.; Jiang, Jingfeng; Carneiro, Antonio A. O.; Hall, Timothy J.

    2012-08-01

    The strain image contrast of some in vivo breast lesions changes with increasing applied load. This change is attributed to differences in the nonlinear elastic properties of the constituent tissues suggesting some potential to help classify breast diseases by their nonlinear elastic properties. A phantom with inclusions and long-term stability is desired to serve as a test bed for nonlinear elasticity imaging method development, testing, etc. This study reports a phantom designed to investigate nonlinear elastic properties with ultrasound elastographic techniques. The phantom contains four spherical inclusions and was manufactured from a mixture of gelatin, agar and oil. The phantom background and each of the inclusions have distinct Young's modulus and nonlinear mechanical behavior. This phantom was subjected to large deformations (up to 20%) while scanning with ultrasound, and changes in strain image contrast and contrast-to-noise ratio between inclusion and background, as a function of applied deformation, were investigated. The changes in contrast over a large deformation range predicted by the finite element analysis (FEA) were consistent with those experimentally observed. Therefore, the paper reports a procedure for making phantoms with predictable nonlinear behavior, based on independent measurements of the constituent materials, and shows that the resulting strain images (e.g., strain contrast) agree with that predicted with nonlinear FEA.

  12. Silicone breast phantoms for elastographic imaging evaluation.

    Science.gov (United States)

    Kashif, Amer S; Lotz, Thomas F; McGarry, Matthew D; Pattison, Adam J; Chase, James G

    2013-06-01

    Breast cancer is a major public health issue for women, and early detection significantly increases survival rate. Currently, there is increased research interest in elastographic soft-tissue imaging techniques based on the correlation between pathology and mechanical stiffness. Anthropomorphic breast phantoms are critical for ex vivo validation of emerging elastographic technologies. This research develops heterogeneous breast phantoms for use in testing elastographic imaging modalities. Mechanical property estimation of eight different elastomers is performed to determine storage moduli (E') and damping ratios (ζ) using a dynamic mechanical analyzer. Dynamic compression testing was carried out isothermally at room temperature over a range of 4-50 Hz. Silicone compositions with physiologically realistic storage modulus were chosen for mimicking skin adipose, cancerous tumors, and pectoral muscles and 13 anthropomorphic breast phantoms were constructed for ex vivo trials of digital image elastotomography (DIET) breast cancer screening system. A simpler fabrication was used to assess the possibility of multiple tumor detection using magnetic resonance elastography (MRE). Silicone materials with ranges of storage moduli (E') from 2 to 570 kPa and damping ratios (ζ) from 0.03 to 0.56 were identified. The resulting phantoms were tested in two different elastographic breast cancer diagnostic modalities. A significant contrast was successfully identified between healthy tissues and cancerous tumors both in MRE and DIET. The phantoms presented promise aid to researchers in elastographic imaging modalities for breast cancer detection and provide a foundation for silicone based phantom materials for mimicking soft tissues of other human organs.

  13. Production of a faithful realistic phantom to human head and thermal neutron flux measurement on the brain surface. Cooperative research

    CERN Document Server

    Yamamoto, K; Kishi, T; Kumada, H; Matsumura, A; Nose, T; Torii, Y; Uchiyama, J; Yamamoto, T

    2002-01-01

    Thermal neutron flux is determined using the gold wires in current BNCT irradiation, so evaluation of arbitrary points after the irradiation is limited in the quantity of these detectors. In order to make up for the weakness, dose estimation of a patient is simulated by a computational dose calculation supporting system. In another way without computer simulation, a medical irradiation condition can be replicate experimentally using of realistic phantom which was produced from CT images by rapid prototyping technique. This phantom was irradiated at a same JRR-4 neutron beam as clinical irradiation condition of the patient and the thermal neutron distribution on the brain surface was measured in detail. This experimental evaluation technique using a realistic phantom is applicable to in vitro cell irradiation experiments for radiation biological effects as well as in-phantom experiments for dosimetry under the nearly medical irradiation condition of patient.

  14. Production of a faithful realistic phantom to human head and thermal neutron flux measurement on the brain surface. Cooperative research

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Uchiyama, Junzo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Endo, Kiyoshi; Yamamoto, Tetsuya; Matsumura, Akira; Nose, Tadao [Tsukuba Univ., Tsukuba, Ibaraki (Japan)

    2002-12-01

    Thermal neutron flux is determined using the gold wires in current BNCT irradiation, so evaluation of arbitrary points after the irradiation is limited in the quantity of these detectors. In order to make up for the weakness, dose estimation of a patient is simulated by a computational dose calculation supporting system. In another way without computer simulation, a medical irradiation condition can be replicate experimentally using of realistic phantom which was produced from CT images by rapid prototyping technique. This phantom was irradiated at a same JRR-4 neutron beam as clinical irradiation condition of the patient and the thermal neutron distribution on the brain surface was measured in detail. This experimental evaluation technique using a realistic phantom is applicable to in vitro cell irradiation experiments for radiation biological effects as well as in-phantom experiments for dosimetry under the nearly medical irradiation condition of patient. (author)

  15. Lipid Emulsion Inhibits Vasodilation Induced by a Toxic Dose of Bupivacaine via Attenuated Dephosphorylation of Myosin Phosphatase Target Subunit 1 in Isolated Rat Aorta

    Science.gov (United States)

    Ok, Seong-Ho; Byon, Hyo-Jin; Kwon, Seong-Chun; Park, Jungchul; Lee, Youngju; Hwang, Yeran; Baik, Jiseok; Choi, Mun-Jeoung; Sohn, Ju-Tae

    2015-01-01

    Lipid emulsions are widely used for the treatment of systemic toxicity that arises from local anesthetics. The goal of this in vitro study was to examine the cellular mechanism associated with the lipid emulsion-mediated attenuation of vasodilation induced by a toxic dose of bupivacaine in isolated endothelium-denuded rat aorta. The effects of lipid emulsion on vasodilation induced by bupivacaine, mepivacaine, and verapamil were assessed in isolated aorta precontracted with phenylephrine, the Rho kinase stimulant NaF, and the protein kinase C activator phorbol 12,13-dibutyrate (PDBu). The effects of Rho kinase inhibitor Y-27632 on contraction induced by phenylephrine or NaF were assessed. The effects of bupivacaine on intracellular calcium concentrations ([Ca2+]i) and tension induced by NaF were simultaneously measured. The effects of bupivacaine alone and lipid emulsion plus bupivacaine on myosin phosphatase target subunit 1 (MYPT1) phosphorylation induced by NaF were examined in rat aortic vascular smooth muscle cells. In precontracted aorta, the lipid emulsion attenuated bupivacaine-induced vasodilation but had no effect on mepivacaine-induced vasodilation. Y-27632 attenuated contraction induced by either phenylephrine or NaF. The lipid emulsion attenuated verapamil-induced vasodilation. Compared with phenylephrine-induced precontracted aorta, bupivacaine-induced vasodilation was slightly attenuated in NaF-induced precontracted aorta. The magnitude of the bupivacaine-induced vasodilation was higher than that of a bupivacaine-induced decrease in [Ca2+]i. Bupivacaine attenuated NaF-induced MYPT1 phosphorylation, whereas lipid emulsion pretreatment attenuated the bupivacaine-induced inhibition of MYPT1 phosphorylation induced by NaF. Taken together, these results suggest that lipid emulsions attenuate bupivacaine-induced vasodilation via the attenuation of inhibition of MYPT1 phosphorylation evoked by NaF. PMID:26664257

  16. Toward a reference standard for tissue phantoms

    Science.gov (United States)

    Di Ninni, Paola; Martelli, Fabrizio; Zaccanti, Giovanni

    2011-03-01

    A reference standard for tissue-simulating phantoms, i.e., a phantom with well known and stable optical properties, reproducible, and easy to be found, would be very useful for many applications based on measurements of diffused light. Although many tissue-equivalent phantoms have been proposed, to our knowledge none of them has been characterized sufficiently well to be suggested as a reference standard. Based on the results of measurements of optical properties we carried out at visible and NIR wavelengths, the use of Intralipid 20% diluted in water as diffusive medium, and of India ink as absorber, is here suggested as a first step towards a diffusive reference standard for tissue-simulating phantoms. As for Intralipid 20%, measurements carried out on samples from nine different batches with expiry dates spreading over ten years showed surprisingly small batch-to-batch variations. For the reduced scattering coefficient the maximum deviation from the value averaged over the nine batches was of about 2%, and the results for the absorption coefficient were very close to those for pure water. As for India ink measurements on samples from different batches and from five different brands showed large inter-brand and inter-batch variations for both the absorption and the extinction coefficient. On the contrary, small variations have been observed for the ratio between the absorption and the extinction coefficient. Intralipid 20% and Indian ink can be therefore easily mixed to obtain liquid phantoms with well known optical properties. This phantom can be a first step towards a reference standard for optical tissue phantoms.

  17. Mechanical Characterization and Material Modeling of Diabetic Aortas in a Rabbit Model.

    Science.gov (United States)

    Tong, Jianhua; Yang, F; Li, X; Xu, X; Wang, G X

    2018-03-01

    Diabetes has been recognized as a major risk factor to cause macrovascular diseases and plays a key role in aortic wall remodeling. However, the effects of diabetes on elastic properties of aortas remain largely unknown and quantitative mechanical data are lacking. Thirty adult rabbits (1.6-2.2 kg) were collected and the type 1 diabetic rabbit model was induced by injection of alloxan. A total of 15 control and 15 diabetic rabbit (abdominal) aortas were harvested. Uniaxial and biaxial tensile tests were performed to measure ultimate tensile strength and to characterize biaxial mechanical behaviors of the aortas. A material model was fitted to the biaxial experimental data to obtain constitutive parameters. Histological and mass fraction analyses were performed to investigate the underlying microstructure and dry weight percentages of elastin and collagen in the control and the diabetic aortas. No statistically significant difference was found in ultimate tensile strength between the control and the diabetic aortas. Regarding biaxial mechanical responses, the diabetic aortas exhibited significantly lower extensibility and significantly higher tissue stiffness than the control aortas. Notably, tissue stiffening occurred in both circumferential and axial directions for the diabetic aortas; however, mechanical anisotropy does not change significantly. The material model was able to fit biaxial experimental data very well. Histology showed that a number of isolated foam cells were embedded in the diabetic aortas and hyperplasia of collagen was identified. The dry weight percentages of collagen within the diabetic aortas increased significantly as compared to the control aortas, whereas no significant change was found for that of elastin. Our data suggest that the diabetes impairs elastic properties and alters microstructure of the aortas and consequently, these changes may further contribute to complex aortic wall remodeling.

  18. Early Results of Ascending Aorta and Aortic Arch Surgery in Albania

    OpenAIRE

    Likaj E; Kacani A; Dumani S; Refatllari A

    2014-01-01

    Background: Treatment of aneurysms of the ascending aorta, arch aorta, or both are surgically challenging and has traditionally carried a high hospital mortality rate. The use of refined operative techniques has resulted in reduced hospital mortality rates. Patients and Methods: We conducted a prospective analysis of consecutive patients who underwent 74 surgical procedures between January 2011 and January 2014, for graft replacement of the ascending aorta or transverse aortic arch. There ...

  19. Pharmacological interventions for phantom limb pain.

    Science.gov (United States)

    Fang, Jun; Lian, Yan-hong; Xie, Kang-jie; Cai, Shu-nü

    2013-02-01

    To review the mechanisms and current clinical application of pharmacological interventions for phantom limb pain. Both Chinese and English language literatures were searched using MEDLINE (1982 - 2011), Pubmed (1982 - 2011) and the Index of Chinese Language Literature (1982 - 2011). Data from published articles about pharmacological management of phantom limb pain in recent domestic and foreign literature were selected. Data extraction Data were mainly extracted from 96 articles which are listed in the reference section of this review. By reviewing the mechanisms and current clinical application of pharmacological interventions for phantom limb pain, including anticonvulsants, antidepressants, local anaesthetics, N-methyl-D-aspartate receptor antagonists, non-steroidal anti-inflammatory drugs, tramadol, opioids, calcitonin, capsaicin, beta-adrenergic blockers, clonidine, muscle relaxants, and emerging drugs, we examined the efficacy and safety of these medications, outlined the limitations and future directions. Although there is lack of evidence-based consensus guidelines for the pharmacological management of phantom limb pain, we recommend tricyclic antidepressants, gabapentin, tramadol, opioids, local anaesthetics and N-methyl-D-aspartate receptor antagonists as the rational options for the treatment of phantom limb pain.

  20. Left Ventricular Myxoma Occluding the Suprarenal Abdominal Aorta in an Infant.

    Science.gov (United States)

    Kawabata, Takuya; Kasahara, Shingo; Ohtsuki, Shin-ichi; Kuroko, Yosuke; Kotani, Yasuhiro; Fujii, Yasuhiro; Yoshizumi, Ko; Arai, Sadahiko; Sano, Shunji

    2015-07-01

    Myxoma is the most common primary cardiac tumor in adults; however, it is extremely rare in infants. Acute occlusion of the abdominal aorta by a cardiac myxoma is also rare. We report the case of an infant with acute occlusion of the suprarenal abdominal aorta by a left ventricular myxoma. The patient underwent successful catheter embolectomy of the abdominal aorta and surgical resection of the cardiac myxoma. This is a very rare case report of the combination of infantile left ventricular myxoma and acute occlusion of the abdominal aorta. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Innovative anisotropic phantoms for calibration of diffusion tensor imaging sequences.

    Science.gov (United States)

    Kłodowski, Krzysztof; Krzyżak, Artur Tadeusz

    2016-05-01

    The paper describes a novel type of anisotropic phantoms designed for b-matrix spatial distribution diffusion tensor imaging (BSD-DTI). Cubic plate anisotropic phantom, cylinder capillary phantom and water reference phantom are described as a complete set necessary for calibration, validation and normalization of BSD-DTI. An innovative design of the phantoms basing on enclosing the anisotropic cores in glass balls filled with liquid made for the first time possible BSD calibration with usage of echo planar imaging (EPI) sequence. Susceptibility artifacts prone to occur in EPI sequences were visibly reduced in the central region of the phantoms. The phantoms were designed for usage in a clinical scanner's head coil, but can be scaled for other coil or scanner types. The phantoms can be also used for a pre-calibration of imaging of other types of phantoms having more specific applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Treatment of traumatic rupture of the thoracic aorta

    Directory of Open Access Journals (Sweden)

    Davidović Lazar

    2008-01-01

    Full Text Available INTRODUCTION Interest for traumatic thoracic aorta rupture stems from the fact that its number continually increases, and it can be rapidly lethal. OBJECTIVE The aim of this study is to present early and long term results as well as experiences of our team in surgical treatment of traumatic thoracic aorta rupture. METHOD Our retrospective study includes 12 patients with traumatic thoracic aorta rupture treated between 1985 and 2007. There were 10 male and two female patients of average age 30.75 years (18-74. RESULTS In six cases, primary diagnosis was established during the first seven days days after trauma, while in 6 more than one month later. In 11 cases, classical open surgical procedure was performed, while endovascular treatment was used in one patient. Three (25% patients died, while two (16.6% had paraplegia. Nine patients (75% were treated without complications, and are in good condition after a mean follow-up period of 9.7 years (from one month to 22 years. CONCLUSION Surgical treatment requires spinal cord protection to prevent paraplegia, using cardiopulmonary by-pass (three of our cases or external heparin-bonded shunts (five of our cases. Cardiopulmonary by-pass is followed with lower incidence of paraplegia, however it is not such a good solution for patients with polytrauma because of hemorrhage. The endovascular repair is a safe and feasible procedure in the acute phase, especially because of traumatic shock and polytrauma which contributes to higher mortality rate after open surgery. On the other hand, in chronic postrauamatic aortic rupture, open surgical treatment is connected with a lower mortality rate and good long-term results. There have been no published data about long-term results of endovascular treatment in the chronic phase.

  3. Real-time phase contrast magnetic resonance imaging for assessment of haemodynamics: from phantom to patients

    Energy Technology Data Exchange (ETDEWEB)

    Traber, Julius; Wurche, Lennart; Dieringer, Matthias A.; Utz, Wolfgang; Knobelsdorff-Brenkenhoff, Florian von; Schulz-Menger, Jeanette [Max-Delbrueck-Centrum and Charite -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Berlin (Germany); Greiser, Andreas [Siemens AG Healthcare Sector, Erlangen (Germany); Jin, Ning [Siemens Medical Solutions USA, Inc., Columbus, OH (United States)

    2016-04-15

    Assessment of haemodynamics is crucial in many cardiac diseases. Phase contrast MRI (PC-MRI) can accurately access it. Arrhythmia is a major limitation in conventional segmented PC-MRI (SEG). A real-time PC-MRI sequence (RT) could overcome this. We validated RT by comparing to SEG. A prototype RT using shared velocity encoding was tested against SEG at 1.5 T in a flow phantom and consecutively included patients with (n = 55) or without (n = 59) aortic valve disease. In patients with atrial fibrillation (Afib, n = 15), only RT was applied. Phantom: PC images were acquired in front of and behind an interchangeable aortic-stenosis-like inlay. Mean velocity and flow were quantified. Patients: PC images were acquired in the ascending aorta, pulmonary trunk and superior caval vein. Peak velocity, stroke volume and regurgitant fraction were quantified. Phantom: Mean velocities (11 ± 1 to 207 ± 10 cm/s) and flow correlated closely between SEG and RT (r ≥ 0.99, ICC ≥ 0.98, p < 0.0005). Patients without AVD or with aortic regurgitation: Concordance of SEG and RT was excellent regarding peak velocities, stroke volumes (r ≥ 0.91, ICC ≥ 0.94, p < 0.0005) and regurgitant fractions (r = 0.95, ICC = 0.95, p < 0.0005). RT was feasible in all patients with Afib. The real-time sequence is accurate compared to conventional segmented PC-MRI. Its applicability in Afib was shown. Real-time PC-MRI might become a valuable tool in arrhythmia. (orig.)

  4. Spiral CT angiography of the abdominal aorta and its branches

    Energy Technology Data Exchange (ETDEWEB)

    Costello, P. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States); Gaa, J. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States)

    1993-08-01

    Spiral CT angiography (CTA) was performed on 19 patients for the pre-operative assessment of abdominal aortic aneurysms and in 3 post-operative renal artery bypass patients. Spiral CTA performed during intravenous contrast infusion provided a volume of data that was reconstructed at thin increments. Images were edited and reformatted either as surface rendered three-dimensional or maximum intensity projection (MIP) displays. Final images were viewed in a cine-loop presentation of quality comparable to conventional angiograms. The entire aorta can be examined from the coeliac axis to mid-pelvis with only 107 ml of 60% contrast. (orig.)

  5. Pseudo-dissection of ascending aorta in inferior myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Grahame K. Goode

    2011-06-01

    Full Text Available Acute aortic dissection is a cardiac emergency which can present as inferior myocardial infarction. It has high morbidity and mortality requiring prompt diagnosis and treatment. Rapid advances in noninvasive imaging modalities have facilitated the early diagnosis of this condition and in ruling out this potentially catastrophic illness. We report an interesting case of a 57 year- old -man who presented with inferior myocardial infarction requiring thrombolysis and temporary pacing wire for complete heart block. An echocardiogram was highly suspicious of aortic dissection. CT scan confirmed that the malposition of the temporary pacing wire through the aorta mimicked aortic dissection.

  6. The challenge in diagnosing coarctation of the aorta.

    Science.gov (United States)

    Hoffman, Julien I

    2017-12-11

    Critical coarctation of the aorta in neonates is a common cause of shock and death. It may be the most difficult of all forms of critical congenital heart disease to diagnose because the obstruction from the coarctation does not appear until several days after birth (and after discharge from the hospital), and because there are no characteristic murmurs. Some of these patients may be detected by neonatal screening by pulse oximetry, but only a minority is so diagnosed. Older patients are usually asymptomatic but, although clinical diagnosis is easy, they are frequently undiagnosed.

  7. Medical image of the week: coral reef aorta

    OpenAIRE

    Eberson L; Ghazala S

    2017-01-01

    No abstract available. Article truncated at 150 words. A 52-year-old woman with no past medical history presented to the emergency department with signs and symptoms concerning for pneumonia. Chest x-ray showed incidental findings of a calcified aortic mass. Subsequently, a follow up computed tomography scan (CT) was obtained which showed coral reef aorta (Figure 1). On physical examination, vital signs were only significant for mildly elevated blood pressure to 146/62 mmHg. She also had norm...

  8. [Partial k-space sampling with zero filling used with phase-contrast flow measurements: in vivo and in vitro validation].

    Science.gov (United States)

    Pertschy, S; Meyer, G P; Waalkes, S; Doeker, R; Koshedub, R; Noeske, R; Galanski, M; Lotz, J

    2006-07-01

    To validate the technique of partial k-space sampling and zero filling with phase-contrast flow measurements as compared to measurements with full k-space sampling. In vitro: A laminar flow phantom was utilized to evaluate the effect of partial k-space sampling on the accuracy, precision and signal-to-noise ratio of phase-contrast flow measurements. In vivo: The effect of partial k-space sampling on the quantification of cardiac output (n = 40 patients) and the duration of the scan were evaluated in the ascending aorta (n = 37) and pulmonary trunk (n = 34) in a prospective study. Partial k-space sampling resulted in an increase in the SNR by 2 % in vitro. The precision was altered by less than 1 %. Flow volumes were systematically overestimated by 3.5 %. No significant differences were found in the in vivo measurements of cardiac output. The scan duration was reduced by 34 % by utilizing partial k-space sampling. Partial k-space sampling can be used to reduce scan time without a significant decrease in the accuracy or precision of phase-contrast flow measurements in large arteries.

  9. Application of semiconductor and upconversion nanomaterials in cosmetics, coatings, and phantoms

    Science.gov (United States)

    Popov, Alexey; Bykov, Alexander; Khaydukov, Eugeny; Semchishen, Vladimir; Kordas, Krisztian; Tuchin, Valery

    2014-10-01

    In this paper, an overview of selected applications of semiconductor (TiO2 and ZnO) and upconversion nanoparticles is presented. Depending on the size, the former are used as scattering and absorbing compounds in sunscreens and tissuemimicking phantoms; and in combination with gypsum - also as an antibacterial coating for indoor premises, while the latter, especially in combination with optical clearing - as a promising component for deep-biotissue imaging both in vitro and in vivo.

  10. Cosmological perturbations in transient phantom inflation scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Richarte, Martin G. [Universidade Federal do Parana, Departamento de Fisica, Caixa Postal 19044, Curitiba (Brazil); Universidad de Buenos Aires, Ciudad Universitaria 1428, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Kremer, Gilberto M. [Universidade Federal do Parana, Departamento de Fisica, Caixa Postal 19044, Curitiba (Brazil)

    2017-01-15

    We present a model of inflation where the inflaton is accommodated as a phantom field which exhibits an initial transient pole behavior and then decays into a quintessence field which is responsible for a radiation era. We must stress that the present unified model only deals with a single field and that the transition between the two eras is achieved in a smooth way, so the model does not suffer from the eternal inflation issue. We explore the conditions for the crossing of the phantom divide line within the inflationary era along with the structural stability of several critical points. We study the behavior of the phantom field within the slow-climb approximation along with the necessary conditions to have sufficient inflation. We also examine the model at the level of classical perturbations within the Newtonian gauge and determine the behavior of the gravitational potential, contrast density and perturbed field near the inflation stage and the subsequent radiation era. (orig.)

  11. Photoacoustic investigation of a neonatal skull phantom

    Science.gov (United States)

    Volinski, Bridget; Hariri, Ali; Fatima, Afreen; Xu, Qiuyun; Nasiriavanaki, Mohammadreza

    2017-03-01

    There is a need for continued research into the diagnosis, prevention and cure of neonatal brain disease and disorders. These disorders lead to fatalities and developmental disorders in infants. Non-invasive imaging techniques are being researched for this purpose. However, the availability of neonatal skull samples for this work is very low. A phantom can be used to simulate the neonatal skull and brain to improve imaging techniques. This study selects a phantom of polyurethane and titanium dioxide and proves its value as a replacement for neonatal skull in research. The methods used for this proof are validation of choice against the literature, transmissivity and acoustic experimentation compared to existing literature, and finally photoacoustic evaluation of the final choice to show its usefulness as a neonatal skull phantom.

  12. MRI phantoms - are there alternatives to agar?

    Directory of Open Access Journals (Sweden)

    Alexandra Hellerbach

    Full Text Available The suitability of different gelling agents as MRI phantoms was evaluated in terms of homogeneity, gel stability and reproducibility. Time and effort for preparation were also taken into account. The relaxation times of various gel compositions were estimated. Carbomer-980 and Carbopol-974P were determined to be promising novel phantom materials. These gelling agents are readily available, inexpensive and easy to handle given that thermal treatment is not required. Furthermore, the viscoelasticity of their polymer network is pH-dependent. With such characteristics, it was even possible to embed sensitive objects and retrieve them after testing. This was demonstrated with a fiber phantom for Diffusion Weighted MRI applications. Since Carbomer-980 and Carbopol-974P are non-hazardous, they are also suitable for multimodal setups (e.g., MRI as well as ultrasonic imaging.

  13. New polymer-based phantom for photoacoustic imaging

    Science.gov (United States)

    Kawaguchi, Yasushi; Iwazaki, Hideaki; Ida, Taiichiro; Nishi, Taiji; Tanikawa, Yukari; Nitta, Naotaka

    2014-03-01

    We will report newly developed polymer-based phantom for photoacoustic (PA) imaging systems. Phantoms are important for performance evaluation and calibration of new modalities; however, there is no established method for making phantoms with no long-term change. We have developed skin mimicking phantoms simulating both optical and acoustic properties (i.e. optical scattering and absorption coefficients, and sound velocity). Furthermore, the phantoms are able to give accurate simulation of blood vessels by Inkjet-printing. Newly developed phantoms are consisted of castor oil included acrylic block copolymer and we can fabricate 0.8mm or less thick sheets and pile them using their self-adhesiveness.

  14. Structured movement representations of a phantom limb associated with phantom limb pain.

    Science.gov (United States)

    Osumi, Michihiro; Sumitani, Masahiko; Wake, Naoki; Sano, Yuko; Ichinose, Akimichi; Kumagaya, Shin-Ichiro; Kuniyoshi, Yasuo; Morioka, Shu

    2015-09-25

    The relation between phantom limb pain (PLP) and the movement representation of a phantom limb remains controversial in several areas of neurorehabilitation, although there are a few studies in which the representation of phantom limb movement was precisely evaluated. We evaluated the structured movement representation of a phantom limb objectively using a bimanual circle-line coordination task. We then investigated the relation between PLP and the structured movement representation. Nine patients with a brachial plexus avulsion injury were enrolled who perceived a phantom limb and had neuropathic pain. While blindfolded, the participants repeatedly drew vertical lines using the intact hand and intended to draw circles using the phantom limb simultaneously. "Drawing of circles" by the phantom limb resulted in an oval transfiguration of the vertical lines ("bimanual coupling" effect). We used an arbitrary ovalization index (OI) to quantify the oval transfiguration. When the OI neared 100%, the trajectory changed toward becoming more circular. A significant negative correlation was observed between the intensity of PLP and the OI (r=-0.66, pphantom limb are necessary for alleviating PLP. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. [Phantom limb pain. Psychological treatment strategies].

    Science.gov (United States)

    Diers, M; Flor, H

    2013-04-01

    Similar to other pain syndromes phantom limb pain is characterized by learning and memory processes that maintain the pain and increase maladaptive plastic changes of the brain: therefore, psychological interventions that change maladaptive memory processes are useful. In addition to traditional psychological interventions, such as pain management training and biofeedback, more recent developments that involve sensory discrimination training, mirror treatment, graded motor imagery, prosthesis training and training in virtual reality are interesting. These interventions not only reduce phantom limb pain but also reverse the associated maladaptive brain changes.

  16. Successful peripheral neuromodulation for phantom limb pain.

    Science.gov (United States)

    Cornish, Philip; Wall, Cindy

    2015-04-01

    For decades, the heterogeneity of the amputee population and the complex interaction of biopsychosocial factors have confounded researchers' attempts to develop an effective treatment for phantom limb pain. Therefore, it remains difficult to treat, and affected patients often experience decreased quality of life, increased psychological distress, and poorer health outcomes. In the case study, we report a novel strategy for the peripheral placement of neuromodulation leads for the treatment of phantom limb pain in a patient who subsequently described complete and consistent pain relief independent of significant variations in psychosocial stress. Wiley Periodicals, Inc.

  17. Static phantom wormholes of finite size

    Science.gov (United States)

    Cataldo, Mauricio; Orellana, Fabian

    2017-09-01

    In this paper we derive new static phantom traversable wormholes by assuming a shape function with a quadratic dependence on the radial coordinate r . We mainly focus our study on wormholes sustained by exotic matter with positive energy density (as seen by any static observer) and a variable equation of state pr/ρ wormhole spacetimes extending to infinity, we show that a quadratic shape function allows us to construct static spacetimes of finite size, composed of a phantom wormhole connected to an anisotropic spherically symmetric distribution of dark energy. The wormhole part of the full spacetime does not fulfill the dominant energy condition, while the dark energy part does.

  18. Development of an Arm Phantom for Testing Non-Invasive Blood Pressure Monitors

    Science.gov (United States)

    Anderson-Jackson, LaTecia D.

    Approximately one in every three adults age 20 older are diagnosed with high blood pressure or hypertension. It is estimated that hypertension affects 78 million people in the United States, is equally prevalent in both men and woman (Crabtree, Stuart-Shor, & McAllister, 2013). In the United States, around 78% of people suffering from hypertension are aware of their condition, with only 68% using hypertensive medications to control their blood pressure (Writing Group et al., 2010). Clinically, blood pressure measurements may lack accuracy, which can be attributed to various factors, including device limitations, cuff mis-sizing and misplacement, white-coat effect, masked hypertension, and lifestyle factors. The development of an arm phantom to simulate physiologic properties of a human arm and arterial BP waveforms may allow us to better assess the accuracy of non-invasive blood pressure (NIBP) monitors. The objective of this study are to: (1) Develop an arm phantom to replicate physiological properties of the human arm, and (2) Incorporate the arm phantom into a mock circulatory flow loop to simulate different physiological blood pressure readings on the bench. A tissue mimicking material, styrene-ethylene-butylene-styrene (SEBS), a co-block polymer was used to develop the arm phantom for in-vitro testing. To determine the optimal mechanical properties for the arm phantom, individual arm components were isolated and tested. A protocol was developed to evaluate various components for optimal arm phantom development. Mechanical testing was conducted on 10%, 15%, and 20% SEBS gel samples for modulus of elasticity measurements in order to simulate physiological properties of the human arm. As a result of the SEBS polymer being a new material for this application, this investigation will contribute to resolving the limitations that occurred during experimentation. In this study, we demonstrated that although SEBS polymer may be an ideal material to use for simulating

  19. DETECTION OF MODIFIED LIPOPROTEINS IN ATHEROSCLEROTIC LESIONS OF HUMAN AORTA

    Directory of Open Access Journals (Sweden)

    P. V. Pigarevsky

    2006-01-01

    Full Text Available Abstract. Specific autoantibodies against acetylated, maleylated and malonic dialdehyde-(MDA-modified lipoproteins are detectable in human plasma. Immunization of rabbits with autologous, correspondingly modified low-density lipoproteins (LDLs did induce autoantibodies against acetylated, maleylated and MDA-modified lipoproteins. In atherosclerotic lesions from hyman aorta, the epitopes have been detected that were recognized by the antibodies to acetylated, maleylated, and MDA-modified LDLs. Such antigens were detected at all atherogenesis stages, beginning with the earliest lesions (lipid spots, and their deposition pattern was quite variable.Rabbit and human autoantibodies against acetylated, maleylated and MDA-modified lipoproteins recognized antigens in human atherosclerotic aorta. Modified proteins were localized both intra- and extracellular in tectum, superficial and deep layers of the atherosclerotic lesions. The most typical mode of depositions for all modified proteins si represented by extracellular deposits in the cap of lipid streaks and fibrous plaques, especially in transitional “shoulder” area.The intimal deposits of modified proteins shared similar features with distribution of apo-B-containing lipoproteins, like as of lipids detectable by Oil Red staining. The areas where modified proteins and apo-B-containing lipoproteins were revealed did often coincide with foci of IgG deposits. Modified proteins were not detectable in the non-affected segments of aortic intima.

  20. Impaired distensibility of ascending aorta in patients with HIV infection

    Directory of Open Access Journals (Sweden)

    Zormpala Alexandra

    2012-07-01

    Full Text Available Abstract Background Our aim was to investigate the aortic distensibility (AD of the ascending aorta and carotid artery intima-media thickness (c-IMT in HIV-infected patients compared to healthy controls. Methods One hundred and five HIV-infected patients (86 males [82%], mean age 41 ± 0.92 years, and 124 age and sex matched HIV-1 uninfected controls (104 males [84%], mean age 39.2 ± 1.03 years were evaluated by high-resolution ultrasonography to determine AD and c-IMT. For all patients and controls clinical and laboratory factors associated with atherosclerosis were recorded. Results HIV- infected patients had reduced AD compared to controls: 2.2 ± 0.01 vs. 2.62 ± 0.01 10-6 cm2 dyn-1, respectively (p -6 cm2 dyn-1, p = 0.01]. In multiadjusted analysis, increasing age and exposure to HAART were independently associated with decreased AD. Conclusion HIV infection is independently associated with decreased distensibility of the ascending aorta, a marker of subclinical atherosclerosis. Increasing age and duration of exposure to HAART are factors further contributing to decreased AD.

  1. Volumetric lattice Boltzmann simulation for blood flow in aorta arteries

    Science.gov (United States)

    Deep, Debanjan; Yu, Huidan (Whitney); Teague, Shawn

    2012-11-01

    Complicated moving boundaries pose a major challenge in computational fluid dynamics for complex flows, especially in the biomechanics of both blood flow in the cardiovascular system and air flow in the respiratory system where the compliant nature of the vessels can have significant effects on the flow rate and wall shear stress. We develop a computation approach to treat arbitrarily moving boundaries using a volumetric representation of lattice Boltzmann method, which distributes fluid particles inside lattice cells. A volumetric bounce-back procedure is applied in the streaming step while momentum exchange between the fluid and moving solid boundary are accounted for in the collision sub-step. Additional boundary-induced migration is introduced to conserve fluid mass as the boundary moves across fluid cells. The volumetric LBM (VLBM) is used to simulate blood flow in both normal and dilated aorta arteries. We first compare flow structure and pressure distribution in steady state with results from Navier-Stokes based solver and good agreements are achieved. Then we focus on wall stress within the aorta for different heart pumping condition and present quantitative measurement of wall shear and normal stress.

  2. Elastin aging and lipid oxidation products in human aorta

    Directory of Open Access Journals (Sweden)

    Kamelija Zarkovic

    2015-04-01

    Full Text Available Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA, (4-hydroxynonenal, malondialdehyde, acrolein, form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development.

  3. The phantom and the supernumerary phantom limb: historical review and new case.

    Science.gov (United States)

    Cipriani, Gabriele; Picchi, Lucia; Vedovello, Marcella; Nuti, Angelo; Fiorino, Mario Di

    2011-12-01

    The way we experience the world is determined by the way our brain works. The phantom limb phenomenon, which is a delusional belief of the presence of a non-existent limb, has a particular fascination in neurology. This positive phenomenon of the phantom limb raises theoretical questions about its nature. After a stroke, some patients experience the perception of an extra limb in addition to the regular set of two arms and two legs. This complex cognitive and perceptual distortion is called supernumerary phantom limb. Here, we review the pathogenesis and historical aspects, and report a new case.

  4. Differential effects of isoproterenol on the activity of angiotensin-converting enzyme in the rat heart and aorta

    Directory of Open Access Journals (Sweden)

    Busatto V.C.W.

    1999-01-01

    Full Text Available The excessive stimulation of beta-adrenergic receptors in the heart induces myocardial hypertrophy. There are several experimental data suggesting that this hypertrophy may also depend, at least partially, on the increase of local production of angiotensin II secondary to the activation of the cardiac renin-angiotensin system. In this study we investigated the effects of isoproterenol on the activity of angiotensin-converting enzyme (ACE in the heart and also in the aorta and plasma. Male Wistar rats weighing 250 to 305 g were treated with a dose of (±-isoproterenol (0.3 mg kg-1 day-1, N = 8 sufficient to produce cardiac hypertrophy without deleterious effects on the pumping capacity of the heart. Control rats (N = 7 were treated with vehicle (corn oil. The animals were killed one week later. ACE activity was determined in vitro in the four cardiac chambers, aorta and plasma by a fluorimetric assay. A significant hypertrophy was observed in both ventricular chambers. ACE activity in the atria remained constant after isoproterenol treatment. There was a significant increase (P<0.05 of ACE activity in the right ventricle (6.9 ± 0.9 to 8.2 ± 0.6 nmol His-Leu g-1 min-1 and in the left ventricle (6.4 ± 1.1 to 8.9 ± 0.8 nmol His-Leu g-1 min-1. In the aorta, however, ACE activity decreased (P<0.01 after isoproterenol (41 ± 3 to 27 ± 2 nmol His-Leu g-1 min-1 while it remained unchanged in the plasma. These data suggest that ACE expression in the heart can be increased by stimulation of beta-adrenoceptors. However, this effect is not observed on other local renin-angiotensin systems, such as the aorta. Our data also suggest that the increased sympathetic discharge and the elevated plasma concentration of catecholamines may contribute to the upregulation of ACE expression in the heart after myocardial infarction and heart failure.

  5. Support for Conference Entitled The Fifth PHANTOM Users Group Workshop

    National Research Council Canada - National Science Library

    Reinig, Karl

    2001-01-01

    The Fifth PHANToM Users Group (PUG2000) brought together, in an intimate setting, participants who are actively engaged in making computer haptics practical and useful through the use of the PHANTOM Haptic Interface...

  6. A computational model unifies apparently contradictory findings concerning phantom pain

    Science.gov (United States)

    Boström, Kim J.; de Lussanet, Marc H. E.; Weiss, Thomas; Puta, Christian; Wagner, Heiko

    2014-06-01

    Amputation often leads to painful phantom sensations, whose pathogenesis is still unclear. Supported by experimental findings, an explanatory model has been proposed that identifies maladaptive reorganization of the primary somatosensory cortex (S1) as a cause of phantom pain. However, it was recently found that BOLD activity during voluntary movements of the phantom positively correlates with phantom pain rating, giving rise to a model of persistent representation. In the present study, we develop a physiologically realistic, computational model to resolve the conflicting findings. Simulations yielded that both the amount of reorganization and the level of cortical activity during phantom movements were enhanced in a scenario with strong phantom pain as compared to a scenario with weak phantom pain. These results suggest that phantom pain, maladaptive reorganization, and persistent representation may all be caused by the same underlying mechanism, which is driven by an abnormally enhanced spontaneous activity of deafferented nociceptive channels.

  7. [Endovascular treatment of 4 patients with a traumatic rupture of the thoracic aorta

    NARCIS (Netherlands)

    Dinkelman, M.K.; Leenen, L.P.H.; Verhagen, H.; Blankensteijn, J.D.

    2003-01-01

    OBJECTIVE: To present our initial results with the endovascular treatment of traumatic rupture of the thoracic aorta. DESIGN: Retrospective. METHOD: Between April and October, 2002, 4 men between the ages of 22 and 46 were treated endovascularly for a traumatic rupture of the thoracic aorta. The

  8. Aortography delays surgery of CT proven acute traumatic rupture of the thoracic aorta; Case report

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, A.; Moreno, R.; Martin, V.; Iniguez, A.; Alvarez, J. (Hospital Universitario de San Carlos, Madrid (Spain). Dept. de Radiodiagnostico, Servicio de Cirurgia Vascular, Servicio de Exploracion Cardiopulmonar, and Unidad de Cuidados Intensivos)

    1991-09-01

    A case of acute traumatic rupture of the thoracic aorta was diagnosed by dynamic CT. Angiographic confirmation was required, delaying surgical repair and contribution to the fatal outcome. If reliable findings of acute traumatic rupture of the thoracic aorta are shown by CT, we question the usefulness of angiographic confirmation in such cases. (orig.).

  9. Impaired Collagen Biosynthesis and Cross-linking in Aorta of Patients With Bicuspid Aortic Valve

    NARCIS (Netherlands)

    Wagsater, Dick; Paloschi, Valentina; Hanemaaijer, Roeland; Hultenby, Kjell; Bank, Ruud A.; Franco-Cereceda, Anders; Lindeman, Jan H. N.; Eriksson, Per

    Background-Patients with bicuspid aortic valve (BAV) have an increased risk of developing ascending aortic aneurysm. In the present study, collagen homeostasis in nondilated and dilated aorta segments from patients with BAV was studied, with normal and dilated aortas from tricuspid aortic valve

  10. Phantom breast sensations are frequent after mastectomy

    DEFF Research Database (Denmark)

    Hansen, Dorthe Marie Helbo; Kehlet, Henrik; Gärtner, Rune

    2011-01-01

    Phantom breast sensation (PBS) following mastectomy has been recognized for many years. PBS is a feeling that the removed breast is still there. The reported prevalence and risk factors have not been established in large well-defined patient series. The purpose of this study was to examine...... the prevalence of PBS following mastectomy and associated risk factors....

  11. Phantoms for Radiation Measurements of Mobile Phones

    DEFF Research Database (Denmark)

    Pedersen, Gert Frølund

    2001-01-01

    Measurements of radiation efficiency for a handheld phone equipped with a patch and a helical antenna operated near the human user have been performed. Both measurements include a simple head plus hand phantom and live persons are considered. The position of the hand on the phone is found...

  12. Phantom breast sensations are frequent after mastectomy

    DEFF Research Database (Denmark)

    Hansen, Dorthe Marie Helbo; Kehlet, Henrik; Gærtner, Rune

    2011-01-01

    Phantom breast sensation (PBS) following mastectomy has been recognized for many years. PBS is a feeling that the removed breast is still there. The reported prevalence and risk factors have not been established in large well-defined patient series. The purpose of this study was to examine...

  13. Anisotropic diffusion phantoms based on microcapillaries

    Science.gov (United States)

    Vellmer, Sebastian; Edelhoff, Daniel; Suter, Dieter; Maximov, Ivan I.

    2017-06-01

    Diffusion MRI is an efficient and widely used technique for the investigation of tissue structure and organisation in vivo. Multiple phenomenological and biophysical diffusion models are intensively exploited for the analysis of the diffusion experiments. However, the verification of the applied diffusion models remains challenging. In order to provide a ;gold standard; and to assess the accuracy of the derived parameters and the limitations of the diffusion models, anisotropic diffusion phantoms with well known architecture are demanded. In the present work we built four anisotropic diffusion phantoms consisting of hollow microcapillaries with very small inner diameters of 5, 10 and 20 μ m and outer diameters of 90 and 150 μ m. For testing the suitability of these phantoms, we performed diffusion measurements on all of them and evaluated the resulting data with a set of popular diffusion models, such as diffusion tensor and diffusion kurtosis imaging, a two compartment model with intra- and extra-capillary water spaces using bi-exponential fitting, and time-dependent diffusion coefficients in Mitra's limit. The perspectives and limitations of these diffusion phantoms are presented and discussed.

  14. New eye phantom for ophthalmic surgery

    Science.gov (United States)

    Fogli, Gessica; Orsi, Gianni; De Maria, Carmelo; Montemurro, Francesca; Palla, Michele; Rizzo, Stanislao; Vozzi, Giovanni

    2014-06-01

    In this work, we designed and realized a new phantom able to mimic the principal mechanical, rheological, and physical cues of the human eye and that can be used as a common benchmark to validate new surgical procedures, innovative vitrectomes, and as a training system for surgeons. This phantom, in particular its synthetic humor vitreous, had the aim of reproducing diffusion properties of the natural eye and can be used as a system to evaluate the pharmacokinetics of drugs and optimization of their dose, limiting animal experiments. The eye phantom was built layer-by-layer starting from the sclera up to the retina, using low cost and easy to process polymers. The validation of the phantom was carried out by mechanical characterization of each layer, by diffusion test with commercial drugs into a purposely developed apparatus, and finally by a team of ophthalmic surgeons. Experiments demonstrated that polycaprolactone, polydimethylsiloxane, and gelatin, properly prepared, are the best materials to mimic the mechanical properties of sclera, choroid, and retina, respectively. A polyvinyl alcohol-gelatin polymeric system is the best for mimicking the viscosity of the human humor vitreous, even if the bevacizumab half-life is lower than in the human eye.

  15. A Rat Body Phantom for Radiation Analysis

    Science.gov (United States)

    Qualls, Garry D.; Clowdsley, Martha S.; Slaba, Tony C.; Walker, Steven A.

    2010-01-01

    To reduce the uncertainties associated with estimating the biological effects of ionizing radiation in tissue, researchers rely on laboratory experiments in which mono-energetic, single specie beams are applied to cell cultures, insects, and small animals. To estimate the radiation effects on astronauts in deep space or low Earth orbit, who are exposed to mixed field broad spectrum radiation, these experimental results are extrapolated and combined with other data to produce radiation quality factors, radiation weighting factors, and other risk related quantities for humans. One way to reduce the uncertainty associated with such extrapolations is to utilize analysis tools that are applicable to both laboratory and space environments. The use of physical and computational body phantoms to predict radiation exposure and its effects is well established and a wide range of human and non-human phantoms are in use today. In this paper, a computational rat phantom is presented, as well as a description of the process through which that phantom has been coupled to existing radiation analysis tools. Sample results are presented for two space radiation environments.

  16. Cortical Depression and Potentiation: Basic Mechanisms for Phantom Pain

    OpenAIRE

    Zhuo, Min

    2012-01-01

    People experience the feeling of the missing body part long after it has been removed after amputation are known as phantom limb sensations. These sensations can be painful, sometimes becoming chronic and lasting for several years (or called phantom pain). Medical treatment for these individuals is limited. Recent neurobiological investigations of brain plasticity after amputation have revealed new insights into the changes in the brain that may cause phantom limb sensations and phantom pain....

  17. Atypical supernumerary phantom limb and phantom limb pain in two patients with pontine hemorrhage.

    Science.gov (United States)

    Yoo, Seung Don; Kim, Dong Hwan; Jeong, Yong Seol; Chon, Jinmann; Bark, Jihea

    2011-06-01

    Phantom limbs are usually observed after amputation of extremities. In patients after a stroke, a similar but rarely occurring phenomenon consisting of the patient experiencing the presence of an additional limb has been described. This phenomenon, generally called supernumerary phantom limb (SPL), may be caused by lesions in the right or left cerebral hemisphere, but has been predominantly reported in patients who have had a right hemispheric stroke. We report two cases of atypical SPL and phantom limb pain (PLP) after pontine hemorrhage. The patients were treated conservatively and their symptoms lasted more than 1 month. This is the first report of SPLs after left pontine hemorrhage, and phantom perception and pain lasted longer than those in previously observed cases. Our results indicate that SPL may be more common than reported; therefore, thorough examinations are essential for the care of stroke patients.

  18. Pharmacology of Endothelium-Dependent and Independent Relaxation of Rabbit Aorta

    DEFF Research Database (Denmark)

    Larsen, Kirsten Vendelbo

    2001-01-01

    adrenergic drugs was studied with regard to the possible dependence on endothelium and possible release of nitric oxide (NO). Isolated rabbit thoracis aorta was used for isometric tension measurements; measurements of NO metabolites (Griess Reaction); and eNOS activity measurements (L-citrulline assay......). The acetylcholine-evoked relaxation of rabbit thoracic aorta was: independent of EDTA and ascorbic acid; the same whether the physiological salt solution (PSS) was oxygenated with 95% or 21 % O2; independent of the phenylephrine-evoked precontractile tension; and did not differ in unstored or cold strored aorta...... that phenylephrine-evoked precontraction of rabbit aorta causes a basal release of NO. The amount of basally released NO is the same independent of gender and it is inactivated by oxygen radicals and divalent metal ions. The acetylcholine-evoked relaxation was uniform along the length of rabbit thoracic aorta...

  19. Computerized scheme for evaluating mammographic phantom images.

    Science.gov (United States)

    Asahara, Masaki; Kodera, Yoshie

    2012-03-01

    The authors developed a computer algorithm to automatically evaluate images of the American College of Radiology (ACR) mammography accreditation phantom. The developed algorithm consist of the edge detection of wax insert, nonuniformity correction of background, and correction for magnification and also calculate the cross-correlation coefficient by image matching technique. The algorithm additionally evaluates target shape for fibers, target contrast for speck groups, and target circularity for masses. To obtain an ideal template image without noise and spatial resolution loss, the wax insert containing the embedded test pattern was extracted from the phantom and radiographed. Two template images and ten test phantom images were prepared for this study. The results of evaluation using the algorithm outputs were compared with the averaged results of observer studies by six skilled observers. In comparing the results from the algorithm outputs with the results of observers, the authors found that the computer outputs were well correlated with the evaluations by observers, and they indicate the quality of the phantom image. The correlation coefficients between results of observer studies and two outputs of computer algorithm, i.e., the cross-correlation coefficient by template matching and indices of target shape for fibers, were 0.89 (95% confidence interval, 0.82-0.93; hereinafter the same) and 0.85 (0.76-0.91). The correlation coefficients between observer's results and two outputs: the cross-correlation coefficient and indices of target contrast for speck groups, were 0.83 (0.79-0.86) and 0.85 (0.81-0.88) and between observer's results and two outputs: the cross-correlation coefficient and indices of target circularity for masses, were 0.90 (0.84-0.94) and 0.87 (0.77-0.92). Image evaluation using the ACR phantom is indispensable in quality control of a mammography system. The proposed algorithm is useful for quality control and image evaluation of mammography

  20. 21 CFR 892.1380 - Nuclear flood source phantom.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear flood source phantom. 892.1380 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1380 Nuclear flood source phantom. (a) Identification. A nuclear flood source phantom is a device that consists of a radiolucent container filled with a...

  1. 21 CFR 892.1420 - Radionuclide test pattern phantom.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide test pattern phantom. 892.1420... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1420 Radionuclide test pattern phantom. (a) Identification. A radionuclide test pattern phantom is a device that consists of an arrangement...

  2. 21 CFR 892.1370 - Nuclear anthropomorphic phantom.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear anthropomorphic phantom. 892.1370 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1370 Nuclear anthropomorphic phantom. (a) Identification. A nuclear anthropomorphic phantom is a human tissue facsimile that contains a...

  3. Revealing the invisible: the paradox of picturing a phantom limb.

    Science.gov (United States)

    Schott, G D

    2014-03-01

    Illustrations of phantom limbs are intriguing as they depict an invisible perception. But such illustrations are also important: they provide a form of objectivity to phenomena, which particularly in the past, have often stretched credulity. Acknowledging the paradox of using images to reveal an absent though sensate body part, depictions of phantom limbs are discussed from the neurological perspective, starting with medieval pictures that showed the miraculous restoration of limbs, and which possibly represented pictorial metaphors for a phantom limb. Centuries later, phantom limbs-whether resulting from amputation or deafferentation-became illustrated, and some reasons for their illustration are considered. Although often depicted by others, the most precise and perhaps revealing illustrations of these phantoms have been those made when patients guide the artist, or draw the phantom themselves. In the case of phantom pains, the painful component too is sometimes illustrated, again, as with the miraculous, in metaphorical terms. More recently, depictions of phantoms have also been revealing in studies of some underlying mechanisms of phantom phenomena, notably in demonstrating novel patterns of referred sensations after amputation and attributable to cortical plasticity. Mention is made of photographs of phantom hands visualized using a mirror box, such visualization recalling full circle the miraculous restoration of limbs pictured in the past. The nature of the outline of the phantom is included in a discussion of demarcation of an invisible body part, before concluding that images of phantom limbs provide an invaluable background to understanding and studying these remarkable sensory phenomena.

  4. Survey of phantom limb pain, phantom sensation and stump pain in Cambodian and New Zealand amputees.

    Science.gov (United States)

    Byrne, Kelly Patrick Anthony

    2011-05-01

    The primary objective of this study is to compare the prevalence of phantom limb pain in New Zealand and Cambodian amputees and to assess the demographics of a sample of amputees from these two countries. All participants were interviewed using a 12-question survey that covered demographic data and reason for amputation and assessed the presence of phantom limb sensation, phantom limb pain, and stump pain. Amputees attending an artificial limb center in Cambodia were approached and interviewed in person. New Zealand amputees attending the Waikato artificial limb center were randomly selected and interviewed by phone. There was no statistically significant difference in phantom limb sensation, phantom limb pain, or stump pain between the two groups. There was a much higher unemployment rate in the Cambodian amputees. There were no other statistically significant differences between the groups Despite very different environments, there was no difference in the phantom limb pain between the groups. One possible explanation is that the severity of neurological injury associated with amputation overrides all the other risk factors that influence the development of other chronic pain syndromes. Wiley Periodicals, Inc.

  5. Appropriateness of internal digital phantoms for monitoring the stability of the UBIS 5000 quantitative ultrasound device in clinical trials.

    Science.gov (United States)

    Hans, D; Alekxandrova, I; Njeh, C; Le-Floch, C; Conicella, G; Laugier, P; Slosman, D O

    2005-04-01

    In bone status assessment, proper quality assurance/quality control is crucial since changes due to disease or therapeutic treatment are very small, in the order of 2-5%. Unlike for dual X-ray absorptiometry, quality control procedures have not been extensively developed and validated for quantitative ultrasound technology, limiting its use in longitudinal monitoring. While the challenge of developing an ideal anthropometric phantom is still open, some manufacturers use the concept of the internal digital phantom mimicking human characteristics to check the stability of their device. The objective of the study was to develop a sensitive model of quality control suitable for the correction of QUS patient data. In order to achieve this goal, we simulated a longitudinal device lifetime with both correct and malfunctioning behaviors. Then, we verified the efficiency of digital phantoms in detecting those changes and subsequently established the in vitro/in vivo relationship. This is the first time that an attempt to validate an internal digital phantom has made, and that this type of validation approach is used. The digital phantom (DP) was designed to mimic normal bone (BUAP2) and osteoporotic bone (BUAP1) properties. The DP was studied using the UBIS 5000 ultrasound device (DMS, France). Diverse malfunctions of the UBIS-5000 were simulated. Several series of measurements were performed on both BUAP1 and 2 and on 12 volunteers at each grade of malfunction. The effect of each simulated malfunction on in vivo and in vitro results was presented graphically by plotting the average BUA values against the percentage change from baseline. The change from baseline in BUA was modeled using linear regression, and the in vivo/in vitro ratio was obtained from the model. All experimentations influenced the measure of BUAP1 and 2 as well as the measure of our 12 volunteers. However, the degree of significance varied as a function of the severity of the malfunction, and the results

  6. Motor control over the phantom limb in above-elbow amputees and its relationship with phantom limb pain.

    Science.gov (United States)

    Gagné, M; Reilly, K T; Hétu, S; Mercier, C

    2009-08-04

    Recent evidence shows that the primary motor cortex continues to send motor commands when amputees execute phantom movements. These commands are retargeted toward the remaining stump muscles as a result of motor system reorganization. As amputation-induced reorganization in the primary motor cortex has been associated with phantom limb pain we hypothesized that the motor control of the phantom limb would differ between amputees with and without phantom limb pain. Eight above-elbow amputees with or without pain were included in the study. They were asked to produce cyclic movements with their phantom limb (hand, wrist, and elbow movements) while simultaneously reproducing the same movement with the intact limb. The time needed to complete a movement cycle and its amplitude were derived from the kinematics of the intact limb. Electromyographic (EMG) activity from different stump muscles and from the homologous muscles on the intact side was recorded. Different EMG patterns were recorded in the stump muscles depending on the movement produced, showing that different phantom movements are associated with distinct motor commands. Phantom limb pain was associated with some aspects of phantom limb motor control. The time needed to complete a full cycle of a phantom movement was systematically shorter in subjects without phantom limb pain. Also, the amount of EMG modulation recorded in a stump muscle during a phantom hand movement was positively correlated with the intensity of phantom limb pain. Since phantom hand movement-related EMG patterns in above-elbow stump muscles can be considered as a marker of motor system reorganization, this result indirectly supports the hypothesis that amputation-induced plasticity is associated with phantom limb pain severity. The discordance between the (amputated) hand motor command and the feedback from above-elbow muscles might partially explain why subjects exhibiting large EMG modulation during phantom hand movement have more phantom

  7. Effects of thapsigargin in isolated rat thoracic aorta

    DEFF Research Database (Denmark)

    Mikkelsen, E O; Thastrup, Ole; Christensen, S B

    1988-01-01

    a concentration related relaxation and shifted the K+-concentration response curve to the right and depressed the maximal response to K+. Removal of vascular endothelium abolished the relaxant response to Tg and increased the sensitivity of the preparations to the contractile effect of Tg. The contractile......, but had no effect on the Tg or on the calcium ionophore A 23187 evoked relaxation. Ultraviolet radiation decreased the relaxant effect of Tg and A 23187 without affecting the carbachol induced relaxations. The results showed that vascular endothelium depressed the contractile effect of Tg and that Tg like...... A 23187 had an endothelium dependent relaxant effect on rat aorta different from that of carbachol. The results indicate that Tg in vascular smooth muscle acts by stimulating the transmembranal influx of extracellular calcium....

  8. Ayahuasca Alters Structural Parameters of the Rat Aorta.

    Science.gov (United States)

    Pitol, Dimitrius L; Siéssere, Selma; Dos Santos, Rafael G; Rosa, Maria L N M; Hallak, Jaime E C; Scalize, Priscilla H; Pereira, Bruno F; Iyomasa, Melina M; Semprini, Marisa; Riba, Jordi; Regalo, Simone C H

    2015-07-01

    Ayahuasca is a hallucinogenic brew traditionally used by Northwestern Amazonian indigenous groups for therapeutic purposes. It is prepared by the decoction of Banisteriopsis caapi with the leaves of Psychotria viridis. Banisteriopsis caapi contains β-carbolines that are inhibitors of monoamine oxidase and P. viris is rich in dimethyltryptamine, a 5-HT(1A/2A/2C) agonist. Acute ayahuasca administration produces moderate cardiovascular effects in healthy volunteers, but information regarding long-term use is lacking. This study investigated the effects of ayahuasca (2-4 mL/kg) in the rat aorta after acute and chronic (14 days) administration. Ayahuasca caused flattening and stretching of vascular smooth muscle cells and changes in the arrangement and distribution of collagen and elastic fibers. Chronic treatment with the higher dose significantly increased media thickness and the ratio of media thickness to lumen diameter. More research is needed on the cardiovascular function of long-term ayahuasca consumers.

  9. Aneurisma de aorta abdominal infectado por Salmonella species

    Directory of Open Access Journals (Sweden)

    Marina Helena Fernandes de Aguiar Alioti

    2016-03-01

    Full Text Available Resumo Os aneurismas de aorta abdominal infecciosos (AAAIs são raros e apresentam uma alta mortalidade devido à septicemia e ao risco de ruptura. A opção terapêutica consagrada consiste na correção aberta com ressecção do aneurisma, debridamento e reconstrução com veia autóloga. Mais recentemente, alguns grupos vêm relatando séries de casos nas quais se realizou tratamento endovascular. Em ambas as opções, a antibioticoterapia adjuvante é imperativa. Relatamos um caso ilustrativo em que o tratamento de escolha foi a cirurgia aberta com reconstrução utilizando-se veia autóloga.

  10. The AORTA Reasoning Framework - Adding Organizational Reasoning to Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt

    -aware and autonomous. The reasoning component makes them organization-aware, and their autonomy is intact because the component does not change the existing reasoning mechanisms. As such, it allows the agents to decide whether to adhere to the system’s expectations. The ability to reason about organizations has......Intelligent agents are entities defined by, among other things, autonomy. In systems of many agents, the agents’ individual autonomy can lead to uncertainty since their behavior cannot always be predicted. Usually, this kind of uncertainty is accommodated by imposing an organization upon the system......; an organization that defines expected behavior of the agents and attempts to restrict the agents’ behavior to let it match the expectations. Restrictions can lead to a decrease in autonomy, contradicting one of the pillars of intelligent agents. This thesis presents the AORTA reasoning framework, which...

  11. Elastin aging and lipid oxidation products in human aorta.

    Science.gov (United States)

    Zarkovic, Kamelija; Larroque-Cardoso, Pauline; Pucelle, Mélanie; Salvayre, Robert; Waeg, Georg; Nègre-Salvayre, Anne; Zarkovic, Neven

    2015-01-01

    Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM) components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs) are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA), (4-hydroxynonenal, malondialdehyde, acrolein), form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Phantom Remodeling Effect of Dorsal Root Entry Zone Lesioning in Phantom Limb Pain Caused by Brachial Plexus Avulsion.

    Science.gov (United States)

    Son, Byung-Chul; Ha, Sang-Woo

    2015-01-01

    Dorsal root entry zone (DREZ) lesioning has been reported to be effective for phantom limb pain caused by brachial plexus avulsion pain. Most reports on DREZ lesioning for brachial plexus avulsion pain have focused on the results of pain relief without a detailed description of phantom sensations following DREZ lesioning. Two patients (1 with amputation and the other nonamputated) with chronic intractable phantom limb pain caused by brachial plexus avulsion underwent DREZ lesioning on the avulsed segments of the cervical spinal cords. Changes of the phantom limb were observed. Immediately following DREZ lesioning, the phantom limb pain disappeared in the amputee, the phantom arm was shortened and the phantom hand disappeared. The other patient with the nonamputated arm reported an immediate 50% reduction in the size of the phantom hand, and pain relief was up to 70% of the preoperative phantom limb pain. There was no further change in the phantom arm and hand during the follow-up of 1.5-2 years. The phantom arms and hands showed a prompt shortening and reduction in size, rather than a disappearance, following successful DREZ lesioning in patients with chronic phantom limb pain caused by brachial plexus avulsion. © 2015 S. Karger AG, Basel.

  13. Fabrication of Two Flow Phantoms for Doppler Ultrasound Imaging.

    Science.gov (United States)

    Zhou, Xiaowei; Kenwright, David A; Wang, Shiying; Hossack, John A; Hoskins, Peter R

    2017-01-01

    Flow phantoms are widely used in studies associated with Doppler ultrasound measurements, acting as an effective experimental validation system in cardiovascular-related research and in new algorithm/instrumentation development. The development of materials that match the acoustic and mechanical properties of the vascular system is of great interest while designing flow phantoms. Although recipes that meet the flow phantom standard defined by the International Electrotechnical Commission 61685 are already available in the literature, the standard procedure for material preparations and phantom fabrications has not been well established. In this paper, two types of flow phantoms, with and without blood vessel mimic, are described in detail in terms of the material preparation and phantom fabrication. The phantom materials chosen for the two phantoms are from published phantom studies, and their physical properties have been investigated previously. Both the flow phantoms have been scanned by ultrasound scanners and images from different modes are presented. These phantoms may be used in the validation and characterization of Doppler ultrasound measurements in blood vessels with a diameter above 1 mm.

  14. Pipe Phantoms With Applications in Molecular Imaging and System Characterization.

    Science.gov (United States)

    Wang, Shiying; Herbst, Elizabeth B; Pye, Stephen D; Moran, Carmel M; Hossack, John A

    2017-01-01

    Pipe (vessel) phantoms mimicking human tissue and blood flow are widely used for cardiovascular related research in medical ultrasound. Pipe phantom studies require the development of materials and liquids that match the acoustic properties of soft tissue, blood vessel wall, and blood. Over recent years, pipe phantoms have been developed to mimic the molecular properties of the simulated blood vessels. In this paper, the design, construction, and functionalization of pipe phantoms are introduced and validated for applications in molecular imaging and ultrasound imaging system characterization. There are three major types of pipe phantoms introduced: 1) a gelatin-based pipe phantom; 2) a polydimethylsiloxane-based pipe phantom; and 3) the "Edinburgh pipe phantom." These phantoms may be used in the validation and assessment of the dynamics of microbubble-based contrast agents and, in the case of a small diameter tube phantom, for assessing imaging system spatial resolution/contrast performance. The materials and procedures required to address each of the phantoms are described.

  15. Toxicology Analysis of Tissue-Mimicking Phantom Made From Gelatin

    Science.gov (United States)

    Dolbashid, A. S.; Hamzah, N.; Zaman, W. S. W. K.; Mokhtar, M. S.

    2017-06-01

    Skin phantom mimics the biological skin tissues as it have the ability to respond to changes in its environment. The development of tissue-mimicking phantom could contributes towards the reduce usage of animal in cosmetics and pharmacokinetics. In this study, the skin phantoms made from gelatin were tested with four different commonly available cosmetic products to determine the toxicity of each substance. The four substances used were; mercury-based whitening face cream, carcinogenic liquid make-up foundation, paraben-based acne cleanser, and organic lip balm. Toxicity test were performed on all of the phantoms. For toxicity testing, topographical and electrophysiological changes of the phantoms were evaluated. The ability of each respective phantom to react with mild toxic substances and its electrical resistance were analysed in to determine the toxicity of all the phantom models. Four-electrode method along with custom made electrical impedance analyser was used to differentiate electrical resistance between intoxicated phantom and non-intoxicated phantom in this study. Electrical resistance values obtained from the phantom models were significantly higher than the control group. The result obtained suggests the phantom as a promising candidate to be used as alternative for toxicology testing in the future.

  16. Usefulness of milnacipran in treating phantom limb pain.

    Science.gov (United States)

    Nagoshi, Yasuhide; Watanabe, Akira; Inoue, Saiko; Kuroda, Tomoki; Nakamura, Mitsuo; Matsumoto, Yoshitake; Fukui, Kenji

    2012-01-01

    Amputation of an extremity often results in the sensation of a "phantom limb" where the patient feels that the limb that has been amputated is still present. This is frequently accompanied by "phantom limb pain". We report here the use of milnacipran, a serotonin and norepinephrine reuptake inhibitor, to treat phantom limb pain after amputation of injured or diseased limbs in three patients. The severity of phantom pain before and during treatment was quantified using a visual analog scale. In one case, phantom limb pain responded partially to treatment with high doses of paroxetine, and then replacement with milnacipran further improved the pain relief and long-term full pain relief was achieved. In the two other cases, milnacipran was used as first-line treatment and phantom limb pain responded rapidly. These results suggest that milnacipran administration may be useful in phantom limb pain, possibly as a first-line treatment.

  17. Phantom limb pain after lower limb trauma: origins and treatments.

    Science.gov (United States)

    Foell, Jens; Bekrater-Bodmann, Robin; Flor, Herta; Cole, Jonathan

    2011-12-01

    Phantom sensations, that is, sensations perceived in a body part that has been lost, are a common consequence of accidental or clinical extremity amputations. Most amputation patients report a continuing presence of the limb, with some describing additional sensations such as numbness, tickling, or cramping of the phantom limb. The type, frequency, and stability of these phantom sensations can vary immensely. The phenomenon of painful phantom sensations, that is, phantom limb pain, presents a challenge for practitioners and researchers and is often detrimental to the patient's quality of life. In addition to the use of conventional therapies for chronic pain disorders, recent years have seen the development of novel treatments for phantom limb pain, based on an increasing body of research on neurophysiological changes after amputation. This article describes the current state of research in regard to the demographics, causal factors, and treatments of phantom limb pain.

  18. Usefulness of milnacipran in treating phantom limb pain

    Science.gov (United States)

    Nagoshi, Yasuhide; Watanabe, Akira; Inoue, Saiko; Kuroda, Tomoki; Nakamura, Mitsuo; Matsumoto, Yoshitake; Fukui, Kenji

    2012-01-01

    Background Amputation of an extremity often results in the sensation of a “phantom limb” where the patient feels that the limb that has been amputated is still present. This is frequently accompanied by “phantom limb pain”. We report here the use of milnacipran, a serotonin and norepinephrine reuptake inhibitor, to treat phantom limb pain after amputation of injured or diseased limbs in three patients. Methods and results The severity of phantom pain before and during treatment was quantified using a visual analog scale. In one case, phantom limb pain responded partially to treatment with high doses of paroxetine, and then replacement with milnacipran further improved the pain relief and long-term full pain relief was achieved. In the two other cases, milnacipran was used as first-line treatment and phantom limb pain responded rapidly. Conclusion These results suggest that milnacipran administration may be useful in phantom limb pain, possibly as a first-line treatment. PMID:23185119

  19. A novel breast software phantom for biomechanical modeling of elastography.

    Science.gov (United States)

    Bhatti, Syeda Naema; Sridhar-Keralapura, Mallika

    2012-04-01

    In developing breast imaging technologies, testing is done with phantoms. Physical phantoms are normally used but their size, shape, composition, and detail cannot be modified readily. These difficulties can be avoided by creating a software breast phantom. Researchers have created software breast phantoms using geometric and/or mathematical methods for applications like image fusion. The authors report a 3D software breast phantom that was built using a mechanical design tool, to investigate the biomechanics of elastography using finite element modeling (FEM). The authors propose this phantom as an intermediate assessment tool for elastography simulation; for use after testing with commonly used phantoms and before clinical testing. The authors design the phantom to be flexible in both, the breast geometry and biomechanical parameters, to make it a useful tool for elastography simulation. The authors develop the 3D software phantom using a mechanical design tool based on illustrations of normal breast anatomy. The software phantom does not use geometric primitives or imaging data. The authors discuss how to create this phantom and how to modify it. The authors demonstrate a typical elastography experiment of applying a static stress to the top surface of the breast just above a simulated tumor and calculate normal strains in 3D and in 2D with plane strain approximations with linear solvers. In particular, they investigate contrast transfer efficiency (CTE) by designing a parametric study based on location, shape, and stiffness of simulated tumors. The authors also compare their findings to a commonly used elastography phantom. The 3D breast software phantom is flexible in shape, size, and location of tumors, glandular to fatty content, and the ductal structure. Residual modulus, maps, and profiles, served as a guide to optimize meshing of this geometrically nonlinear phantom for biomechanical modeling of elastography. At best, low residues (around 1-5 KPa) were

  20. Arterial wall metabolism in experimental hypertension of coarctation of the aorta of short duration

    Science.gov (United States)

    Hollander, William; Kramsch, Dieter M.; Farmelant, Melvin; Madoff, Irving M.

    1968-01-01

    Coarctation of the mid-thoracic aorata was surgically produced in mongrel dogs which were sacrificed from 4-12 wk after the operation. As compared to the findings in control animals, the sodium, chloride, and water content of the hypetensive portion of the coarcted thoracic aorta was significantly elevated, whereas the electrolyte and water content of the relatively normotensive portion of the coarcted aorta was normal. The sodium, potassium, and water content of the pulmonary artery, skeletal muscle, and cardiac muscle of the coarcted dog was not altered. These observations suggest that an elevated arterial pressure may influence the electrolyte and water composition of the arteries. The arterial pressure also may influence the content and synthesis of acid mucopolysaccharides (MPS) in the arteries since the content of sulfated MPS and the incorporation of injected radiosulfate into sulfated MPS were significantly increased in the hypertensive portion of the coarcted thoracic aorta but were significantly reduced in the relatively normotensive (“hypotensive”) portion of the coarcted aorta. The observed increase in MPS may have been a factor directly responsible for the increase in the sodium content of the hypertensive aorta since MPS can act as polyelectrolytes and bind cations. Although the arterial pressure may influence certain metabolic functions in the arteries, it did not appear to have a direct effect on the arterial lipids since the lipid content of the hypertensive and of the relatively normotensive portions of the coarcted aorta were comparable to the values found in the normal aorta. Images PMID:5645864

  1. Optical phantoms with adjustable subdiffusive scattering parameters

    Science.gov (United States)

    Krauter, Philipp; Nothelfer, Steffen; Bodenschatz, Nico; Simon, Emanuel; Stocker, Sabrina; Foschum, Florian; Kienle, Alwin

    2015-10-01

    A new epoxy-resin-based optical phantom system with adjustable subdiffusive scattering parameters is presented along with measurements of the intrinsic absorption, scattering, fluorescence, and refractive index of the matrix material. Both an aluminium oxide powder and a titanium dioxide dispersion were used as scattering agents and we present measurements of their scattering and reduced scattering coefficients. A method is theoretically described for a mixture of both scattering agents to obtain continuously adjustable anisotropy values g between 0.65 and 0.9 and values of the phase function parameter γ in the range of 1.4 to 2.2. Furthermore, we show absorption spectra for a set of pigments that can be added to achieve particular absorption characteristics. By additional analysis of the aging, a fully characterized phantom system is obtained with the novelty of g and γ parameter adjustment.

  2. Characterization of atherosclerotic disease in thoracic aorta: A 3D, multicontrast vessel wall imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Changwu [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Department of Radiology, The Second Clinical Medical College, Yangzhou University, Yangzhou (China); Qiao, Huiyu; He, Le [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Yuan, Chun [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Department of Radiology, University of Washington, Seattle, WA (United States); Chen, Huijun; Zhang, Qiang; Li, Rui [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China); Wang, Wei; Du, Fang [Department of Radiology, The Second Clinical Medical College, Yangzhou University, Yangzhou (China); Li, Cheng, E-mail: cjr.licheng@vip.163.com [Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing (China); Zhao, Xihai, E-mail: xihaizhao@tsinghua.edu.cn [Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing (China)

    2016-11-15

    Purpose: To investigate the characteristics of plaque in the thoracic aorta using three dimensional multicontrast magnetic resonance imaging. Materials and methods: Elderly subjects (≥60 years) were recruited in this study. Thoracic aorta was imaged on a 3.0T MR scanner by acquiring multicontrast sequences. The plaque burden was evaluated by measuring lumen area, wall area, wall thickness, and normalized wall index. The presence or absence of plaque and intraplaque hemorrhage (IPH)/mural thrombus (MT) were identified. The characteristics of atherosclerosis among different thoracic aorta segments (AAO: ascending aorta; AOA: aortic arch, and DOA: descending aorta) were determined. Results: Of 66 recruited subjects (mean age 72.3 ± 6.2 years, 30 males), 55 (83.3%) had plaques in the thoracic aorta. The prevalence of plaque in AAO, AOA, and DAO was 5.4%, 72.7%, and 71.2%, respectively. In addition, 21.2% of subjects were found to have lesions with IPH/MT in the thoracic aorta. The prevalence of IPH/MT in segment of AAO, AOA and DAO was 0%, 13.6%, and 12.1%, respectively. The aortic wall showed the highest NWI in DAO (34.1% ± 4.8%), followed by AOA (31.2% ± 5%), and AAO (26.8% ± 3.3%) (p < 0.001). Conclusion: Three dimensional multicontrast MR imaging is capable of characterizing atherosclerotic plaques in the thoracic aorta. The findings of high prevalence of plaques and the presence of high risk plaques in the thoracic aorta suggest early screening for aortic vulnerable lesions in the elderly.

  3. Phantom Space-times in Fake Supergravity

    OpenAIRE

    Taam, Maryam Bu; Sabra, Wafic A.

    2015-01-01

    We discuss phantom metrics admitting Killing spinors in fake N=2 , D=4 supergravity coupled to vector multiplets. The Abelian U(1) gauge fields in the fake theory have kinetic terms with the wrong sign. We solve the Killing spinor equations for the standard and fake theories in a unified fashion by introducing a parameter which distinguishes between the two theories. The solutions found are fully determined in terms of algebraic conditions, the so-called stabilisation equations, in which the ...

  4. Freehand ultrasound calibration: phantom versus tracked pointer

    Science.gov (United States)

    Welch, Mattea; Andrea, Jennifer; Ungi, Tamas; Fichtinger, Gabor

    2013-03-01

    PURPOSE: Ultrasound-guided tracked navigation requires spatial calibration between the ultrasound beam and the tracker. We examined the reproducibility and accuracy of two popular open source calibration methods1 with a handheld linear ultrasound transducer. METHODS: A total of 10 calibrations were performed using (1) a double N-wire phantom with automatic image segmentation and registration; (2) and registration of landmark points collected with a tracked pointer. Reproducibility and accuracy were characterized by comparing the resulting transformation matrices, and by comparing ground truth landmark points. RESULTS: Transformation matrices calculated with an N-wire phantom showed a variance of X: 0.02 mm (in the direction of sound propagation), Y: 0.03 mm (in the direction of transducer elements) and Z: 0.21 mm (in the elevation direction). Transformation matrices obtained with tracked pointer showed a variance of X: 0.1 mm, Y: 0.10 mm and Z: 0.43 mm. Calibration accuracy was tested with ground truth cross wire points. The N-wire phantom provided a calibration with a distance from ground truth of X: 2.44 +/- 1.44 mm, Y: 1.21 +/- 0.88 mm, and Z: 1.12 +/- 0.82 mm. Tracked pointer calibration had a distance from the ground truth of X: 0.23 +/- 0.16 mm, Y: 0.62 +/- 0.31 mm, and Z: 0.45 +/- 0.33 mm. Distance from ground truth was significantly less (ptracked pointer method in all directions. CONCLUSION: Calibration using a tracked pointer had a slightly greater variance; however it showed better accuracy over calibrations calculated with N-wire phantoms.

  5. Automatic Synthesis of Anthropomorphic Pulmonary CT Phantoms

    Science.gov (United States)

    Jimenez-Carretero, Daniel; San Jose Estepar, Raul; Diaz Cacio, Mario; Ledesma-Carbayo, Maria J.

    2016-01-01

    The great density and structural complexity of pulmonary vessels and airways impose limitations on the generation of accurate reference standards, which are critical in training and in the validation of image processing methods for features such as pulmonary vessel segmentation or artery–vein (AV) separations. The design of synthetic computed tomography (CT) images of the lung could overcome these difficulties by providing a database of pseudorealistic cases in a constrained and controlled scenario where each part of the image is differentiated unequivocally. This work demonstrates a complete framework to generate computational anthropomorphic CT phantoms of the human lung automatically. Starting from biological and image-based knowledge about the topology and relationships between structures, the system is able to generate synthetic pulmonary arteries, veins, and airways using iterative growth methods that can be merged into a final simulated lung with realistic features. A dataset of 24 labeled anthropomorphic pulmonary CT phantoms were synthesized with the proposed system. Visual examination and quantitative measurements of intensity distributions, dispersion of structures and relationships between pulmonary air and blood flow systems show good correspondence between real and synthetic lungs (p > 0.05 with low Cohen’s d effect size and AUC values), supporting the potentiality of the tool and the usefulness of the generated phantoms in the biomedical image processing field. PMID:26731653

  6. Materials for phantoms for terahertz pulsed imaging

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Gillian C [Academic Unit of Medical Physics, University of Leeds, Wellcome Wing, Leeds General Infirmary, Great George Street, Leeds, LS1 3EX (United Kingdom); Berry, Elizabeth [Academic Unit of Medical Physics, University of Leeds, Wellcome Wing, Leeds General Infirmary, Great George Street, Leeds, LS1 3EX (United Kingdom); Smye, Stephen W [Department of Medical Physics and Engineering, Leeds Teaching Hospitals NHS Trust, St James University Hospital, Leeds, LS9 7TF (United Kingdom); Brettle, David S [Department of Medical Physics and Engineering, Leeds Teaching Hospitals NHS Trust, St James University Hospital, Leeds, LS9 7TF (United Kingdom)

    2004-11-07

    Phantoms are commonly used in medical imaging for quality assurance, calibration, research and teaching. They may include test patterns or simulations of organs, but in either case a tissue substitute medium is an important component of the phantom. The aim of this work was to identify materials suitable for use as tissue substitutes for the relatively new medical imaging modality terahertz pulsed imaging. Samples of different concentrations of the candidate materials TX151 and napthol green dye were prepared, and measurements made of the frequency-dependent absorption coefficient (0.5 to 1.5 THz) and refractive index (0.5 to 1.0 THz). These results were compared qualitatively with measurements made in a similar way on samples of excised human tissue (skin, adipose tissue and striated muscle). Both materials would be suitable for phantoms where the dominant mechanism to be simulated is absorption ({approx}100 cm{sup -1} at 1 THz) and where simulation of the strength of reflections from boundaries is not important; for example, test patterns for spatial resolution measurements. Only TX151 had a frequency-dependent refractive index close to that of tissue, and could therefore be used to simulate the layered structure of skin, the complexity of microvasculature or to investigate frequency-dependent interference effects that have been noted in terahertz images. (note)

  7. Automatic Synthesis of Anthropomorphic Pulmonary CT Phantoms.

    Directory of Open Access Journals (Sweden)

    Daniel Jimenez-Carretero

    Full Text Available The great density and structural complexity of pulmonary vessels and airways impose limitations on the generation of accurate reference standards, which are critical in training and in the validation of image processing methods for features such as pulmonary vessel segmentation or artery-vein (AV separations. The design of synthetic computed tomography (CT images of the lung could overcome these difficulties by providing a database of pseudorealistic cases in a constrained and controlled scenario where each part of the image is differentiated unequivocally. This work demonstrates a complete framework to generate computational anthropomorphic CT phantoms of the human lung automatically. Starting from biological and image-based knowledge about the topology and relationships between structures, the system is able to generate synthetic pulmonary arteries, veins, and airways using iterative growth methods that can be merged into a final simulated lung with realistic features. A dataset of 24 labeled anthropomorphic pulmonary CT phantoms were synthesized with the proposed system. Visual examination and quantitative measurements of intensity distributions, dispersion of structures and relationships between pulmonary air and blood flow systems show good correspondence between real and synthetic lungs (p > 0.05 with low Cohen's d effect size and AUC values, supporting the potentiality of the tool and the usefulness of the generated phantoms in the biomedical image processing field.

  8. Klebsiella pneumoniae Pseudoaneurysm of the Ascending Aorta after Coronary Artery Bypass Graft

    Directory of Open Access Journals (Sweden)

    Seyed Khalil Forouzannia

    2010-05-01

    Full Text Available "nMycotic pseudoaneurysm of the ascending aorta is rare in patients undergoing coronary artery bypass graft (CABG and usually caused by staphylococcus aureus. We describe a patient with a mycotic pseudoaneurysm of the ascending aorta at the proximal vein graft anastomosis site after CABG. Culture from the sinus tract of the sternum and from the aneurysm sac was Klebsiella pneumoniae. Surgical technique was patch repair of aorta under hypothermic circulatory arrest. He is asymptomatic at 24 months follow-up.

  9. [Somatognosis, body schema and the phenomena of somatic and visceral phantoms and phantom pain].

    Science.gov (United States)

    Tichý, J

    2003-01-01

    The body scheme is a complex of memory patterns secured in the structures of the brain, where the parietal lobes play the most important role. Basic principles are given by the genetic programming of the structure and function along with the synthesis of information brought by means of sensory activity. The unitary perception of the body scheme is a dynamic image, enabling conscious and unconscious representation of our body, its parts, their functions, position, shape and/or movements. The recognition of the body scheme in humans is named somatognosia. Disorders of somatognosia include visceral and somatic phantom, phantom pain and other disorders related to the capability of communication by means of language: autotopoagnosia, hemiasomatognosia, pain asymboly, anosognosia of hemiplegia, anosognosia of blindness, deafness, neglect and other defects appearing at the neurologist's and psychiatrist's borderline of interest. Interest in the visceral phantom is usually much smaller than that in the phantom limb. The aim of this paper was to draw the to phantom phenomena in patients following rectum amputation and colostomy. A survey of contemporary knowledge about the body scheme and its disorders, cortical plasticity and the problem of cortical maladaptation are presented.

  10. A study of partial volume effect on SPECT imaging using myocardial phantom. With HCM (ASH) model myocardial phantom

    Energy Technology Data Exchange (ETDEWEB)

    Onoguchi, Masahisa [Kanazawa Univ. (Japan). School of Medicine

    1997-05-01

    In order to evaluate simultaneously both myocardial perfusion and regional wall motion using ECG-gated myocardial SPECT imaging, correction for the partial volume effect (PVE) should be performed. For the quantitative analysis of myocardial SPECT imaging in patients with hypertrophic cardiomyopathy (HCM), we formed a new phantom simulating HCM with various septal wall thicknesses and estimated PVE using the recovery coefficient (RC). The value of RC in all phantoms increased with increasing thickness of the septal wall reaching a plateau at 25 mm for the cylindrical phantom and 25 mm for the Ep-phantom. Compared with the RC value, the PMMA-phantom had little influence on PVE. Therefore, our results suggested that the count in the septal wall could be underestimated if PVE was corrected by the value obtained for the cylindrical phantom. In conclusion, our new phantom simulating HCM was useful in assessing PVE in the hypertrophic septal wall. (author)

  11. Computerized scheme for evaluating mammographic phantom images

    Energy Technology Data Exchange (ETDEWEB)

    Asahara, Masaki; Kodera, Yoshie [Graduate School of Medical Sciences, Nagoya University, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan) and Department of Radiology, Kagawa University Hospital, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793 (Japan); Graduate School of Medical Sciences, Nagoya University, 1-1-20 Daiko-minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan)

    2012-03-15

    Purpose: The authors developed a computer algorithm to automatically evaluate images of the American College of Radiology (ACR) mammography accreditation phantom. Methods: The developed algorithm consist of the edge detection of wax insert, nonuniformity correction of background, and correction for magnification and also calculate the cross-correlation coefficient by image matching technique. The algorithm additionally evaluates target shape for fibers, target contrast for speck groups, and target circularity for masses. To obtain an ideal template image without noise and spatial resolution loss, the wax insert containing the embedded test pattern was extracted from the phantom and radiographed. Two template images and ten test phantom images were prepared for this study. The results of evaluation using the algorithm outputs were compared with the averaged results of observer studies by six skilled observers. Results: In comparing the results from the algorithm outputs with the results of observers, the authors found that the computer outputs were well correlated with the evaluations by observers, and they indicate the quality of the phantom image. The correlation coefficients between results of observer studies and two outputs of computer algorithm, i.e., the cross-correlation coefficient by template matching and indices of target shape for fibers, were 0.89 (95% confidence interval, 0.82-0.93; hereinafter the same) and 0.85 (0.76-0.91). The correlation coefficients between observer's results and two outputs: the cross-correlation coefficient and indices of target contrast for speck groups, were 0.83 (0.79-0.86) and 0.85 (0.81-0.88) and between observer's results and two outputs: the cross-correlation coefficient and indices of target circularity for masses, were 0.90 (0.84-0.94) and 0.87 (0.77-0.92). Conclusions: Image evaluation using the ACR phantom is indispensable in quality control of a mammography system. The proposed algorithm is useful for

  12. Design and characterization of a device to quantify the magnetic drug targeting efficiency of magnetic nanoparticles in a tube flow phantom by magnetic particle spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Radon, Patricia, E-mail: patricia.radon@ptb.de; Löwa, Norbert; Gutkelch, Dirk; Wiekhorst, Frank

    2017-04-01

    The aim of magnetic drug targeting (MDT) is to transfer a therapeutic drug coupled to magnetic nanoparticles (MNP) to desired disease locations (e.g. tumor region) with the help of magnetic field gradients. To transfer the MDT approach into clinical practice a number of important issues remain to be solved. We developed and characterized an in-vitro flow phantom to provide a defined and reproducible MDT environment. The tube system of the flow phantom is directed through the detection coil of a magnetic particle spectroscopy (MPS) device to determine the targeting efficiency. MPS offers an excellent temporal resolution of seconds and an outstanding specific sensitivity of some nanograms of iron. In the flow phantom different MNP types, magnet geometries and tube materials can be employed to vary physical parameters like diameter, flow rate, magnetic targeting gradient, and MNP properties. - Highlights: • Flow phantom for magnetic targeting. • MPS for quantitative MNP detection. • ng detection limit for MNP.

  13. A multimodality vascular imaging phantom of an abdominal aortic aneurysm with a visible thrombus

    Energy Technology Data Exchange (ETDEWEB)

    Allard, Louise; Chayer, Boris; Qin Zhao [Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Quebec H2L 2W5 (Canada); Soulez, Gilles [Department of Radiology, University of Montreal Hospital (CHUM), Quebec H2L 2M1 (Canada); Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Quebec H3T 1J4 (Canada); Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada); Roy, David [Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada); Cloutier, Guy [Laboratory of Biorheology and Medical Ultrasonics, Research Center, University of Montreal Hospital (CRCHUM), Quebec H2L 2W5 (Canada); Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal, Quebec H3T 1J4 (Canada); Institute of Biomedical Engineering, University of Montreal, Quebec H3T 1J4 (Canada)

    2013-06-15

    Purpose: With the continuous development of new stent grafts and implantation techniques, it has now become technically feasible to treat abdominal aortic aneurysms (AAA) with challenging anatomy using endovascular repair with standard, fenestrated, or branched stent-grafts. In vitro experimentations are very useful to improve stent-graft design and conformability or imaging guidance for stent-graft delivery or follow-up. Vascular replicas also help to better understand the limitation of endovascular approaches in challenging anatomy and possibly improve surgical planning or training by practicing high risk clinical procedures in the laboratory to improve outcomes in the operating room. Most AAA phantoms available have a very basic anatomy, which is not representative of the clinical reality. This paper presents a method of fabrication of a realistic AAA phantom with a visible thrombus, as well as some mechanical properties characterizing such phantom. Methods: A realistic AAA geometry replica of a real patient anatomy taken from a multidetector computed tomography (CT) scan was manufactured. To demonstrate the multimodality imaging capability of this new phantom with a thrombus visible in magnetic resonance (MR) angiography, CT angiography (CTA), digital subtraction angiography (DSA), and ultrasound, image acquisitions with all these modalities were performed by using standard clinical protocols. Potential use of this phantom for stent deployment was also tested. A rheometer allowed defining hyperelastic and viscoelastic properties of phantom materials. Results: MR imaging measurements of SNR and CNR values on T1 and T2-weighted sequences and MR angiography indicated reasonable agreement with published values of AAA thrombus and abdominal components in vivo. X-ray absorption also lay within normal ranges of AAA patients and was representative of findings observed on CTA, fluoroscopy, and DSA. Ultrasound propagation speeds for developed materials were also in

  14. Decellularized aortic homografts for aortic valve and aorta ascendens replacement.

    Science.gov (United States)

    Tudorache, Igor; Horke, Alexander; Cebotari, Serghei; Sarikouch, Samir; Boethig, Dietmar; Breymann, Thomas; Beerbaum, Philipp; Bertram, Harald; Westhoff-Bleck, Mechthild; Theodoridis, Karolina; Bobylev, Dmitry; Cheptanaru, Eduard; Ciubotaru, Anatol; Haverich, Axel

    2016-07-01

    The choice of valve prosthesis for aortic valve replacement (AVR) in young patients is challenging. Decellularized pulmonary homografts (DPHs) have shown excellent results in pulmonary position. Here, we report our early clinical results using decellularized aortic valve homografts (DAHs) for AVR in children and mainly young adults. This prospective observational study included all 69 patients (44 males) operated from February 2008 to September 2015, with a mean age of 19.7 ± 14.6 years (range 0.2-65.3 years). In 18 patients, a long DAH was used for simultaneous replacement of a dilated ascending aorta as an extended aortic root replacement (EARR). Four patients received simultaneous pulmonary valve replacement with DPH. Thirty-nine patients (57%) had a total of 62 previous operations. The mean aortic cross-clamp time in isolated cases was 129 ± 41 min. There was 1 conduit-unrelated death. The mean DAH diameter was 22.4 ± 3.7 mm (range, 10-29 mm), the average peak gradient was 14 ± 15 mmHg and the mean aortic regurgitation grade (0.5 = trace, 1 = mild) was 0.6 ± 0.5. The mean effective orifice area (EOA) of 25 mm diameter DAH was 3.07 ± 0.7 cm(2). DAH annulus z-values were 1.1 ± 1.1 at implantation and 0.7 ± 1.3 at the last follow-up. The last mean left ventricle ejection fraction and left ventricle end diastolic volume index was 63 ± 7% and 78 ± 16 ml/m(2) body surface area, respectively. To date, no dilatation has been observed at any level of the graft during follow-up; however, the observational time is short (140.4 years in total, mean 2.0 ± 1.8 years, maximum 7.6 years). One small DAH (10 mm at implantation) had to be explanted due to subvalvular stenosis and developing regurgitation after 4.5 years and was replaced with a 17 mm DAH without complication. No calcification of the explanted graft was noticed intraoperatively and after histological analysis, which revealed extensive recellularization without inflammation. DAHs withstand systemic

  15. Brachial plexus block in phantom limb pain: a case report.

    Science.gov (United States)

    Preissler, Sandra; Dietrich, Caroline; Meissner, Winfried; Huonker, Ralph; Hofmann, Gunther O; Miltner, Wolfgang H R; Weiss, Thomas

    2011-11-01

    The purpose of this case report is twofold: first, to present evidence of long-lasting relief in a patient suffering from phantom limb pain after pharmacologically blocking his plexus brachialis and, second, to replicate results from a previous study focusing on cortical reorganization and phantom limb pain. Before regional anesthesia, the patient suffered from a phantom hand that cramped and was immovable. We performed a diagnostic axillary blockade of the brachial plexus to differentiate peripheral from more central contributions to phantom limb pain. During blockade of the brachial plexus, the patient reported a reduction of phantom limb pain for the first time following years of suffering and a complete loss of cramping together with muscle relaxation of the phantom hand. Additionally, we found cortical reorganization in the primary somatosensory cortex (re-reorganization). Strikingly, the relaxed phantom limb together with the reduction of phantom limb pain remained preserved even 6 months after blockade of the brachial plexus. A single temporary blockade of the brachial plexus may relieve phantom limb pain and unpleasant phantom feelings (cramping) for an extended period. Wiley Periodicals, Inc.

  16. A realistic pelvic phantom for electrical impedance measurement.

    Science.gov (United States)

    Dunne, Eoghan; McGinley, Brian; O'Halloran, Martin; Porter, Emily

    2017-12-22

    To design and fabricate an anatomically and conductively accurate phantom for electrical impedance studies of non-invasive bladder volume monitoring. Approach: A modular pelvic phantom was designed and fabricated, consisting of a mechanically and conductively stable boundary wall, a background medium, and bladder phantoms. The wall and bladders are made of conductive polyurethane. The background material is an ultrasound gel-based mixture, with conductivity matched to a weighted average of the pelvic cavity organs, bone, muscle and fat. The phantom boundary is developed using a computer tomography model of a male human pelvis. The bladder phantoms were designed to correlate with human bladder dimensions. Electrical impedance measurements of the phantom were recorded, and images produced using six different bladder phantoms and a realistic finite element model. Main results: Five different bladder volumes were successfully imaged using an empty bladder as a reference. The average conductivity index from the reconstructed images showed a strong positive correlation with the bladder phantom volumes. Significance: A conductively and anatomically accurate pelvic phantom was developed for non-invasive bladder volume monitoring using electrical impedance measurements. Several bladders were designed to correlate with actual human bladder volumes, allowing for accurate volume estimation. The conductivity of the phantom is accurate over 50-250 kHz. This phantom can allow: changeable electrode location, contact and size; multi-layer electrodes configurations; increased complexity by addition of other organ or bone phantoms; and electrode movement and deformation. Overall, the pelvic phantom enables greater scope for experimentation and system refinement as a precursor to in-man clinical studies. © 2017 Institute of Physics and Engineering in Medicine.

  17. Giant coronary cameral fistula with coarctation of aorta in a neonate

    Directory of Open Access Journals (Sweden)

    Neeraj Awasthy

    2015-01-01

    Full Text Available A coronary cameral fistula (CCF involves a sizable communication between a coronary artery and a cardiac chamber. We present a case of giant coronary cameral fistula associated with coarctation of aorta in a 13 days old neonate.

  18. Effect of chronic uremia on the transcriptional profile of the calcified aorta analyzed by RNA sequencing

    DEFF Research Database (Denmark)

    Rukov, Jakob Lewin; Gravesen, Eva; Mace, Maria L.

    2016-01-01

    The development of vascular calcification (VC) in chronic uremia (CU) is a tightly regulated process controlled by factors promoting and inhibiting mineralization. Next-generation high-throughput RNA sequencing (RNA-seq) is a powerful and sensitive tool for quantitative gene expression profiling...... and the detection of differentially expressed genes. In the present study, we, for the first time, used RNA-seq to examine rat aorta transcriptomes from CU rats compared with control rats. Severe VC was induced in CU rats, which lead to extensive changes in the transcriptional profile. Among the 10,153 genes...... by circulating Klotho only or if Klotho is produced locally in the vasculature. We found that Klotho was neither expressed in the normal aorta nor calcified aorta by RNA-seq. In conclusion, we demonstrated extensive changes in the transcriptional profile of the uremic calcified aorta, which were consistent...

  19. Effect of camelina oil on the structure of aortas in rats

    DEFF Research Database (Denmark)

    Pawlowska, Marta; Harrison, Adrian Paul; Piersiak, Tomasz

    2016-01-01

    The aim of the present study was to determine whether a disturbance of hormonal homeostasis caused by ovariectomy influences the elasticity and wall structure of the abdominal aorta and whether camelina oil administration has an effect on the properties of the abdominal aorta in rats after...... the treated rats received camelina oil at doses of 5 g/kg/b.w. (OVX2) or 9 g/kg/b.w. (OVX3) once a day. The rats were euthanized 7 weeks after the surgery, and the aorta, before the right and left common iliac arteries, was removed, cut into 5 mm pieces and exposed to a series of step-wise increases...... in tension. Aortic wall elasticity was measured in duplicate. Samples of the aorta were also prepared for histology (total aortic wall thickness, thickness of tunica intima and media, thickness of adventitia) and immunohistochemistry (volume and mean fluorescence intensity of collagens I and III and elastin...

  20. Minimum Variance Signal Selection for Aorta Radius Estimation Using Radar

    Directory of Open Access Journals (Sweden)

    Hamran Svein-Erik

    2010-01-01

    Full Text Available Abstract This paper studies the optimum signal choice for the estimation of the aortic blood pressure via aorta radius, using a monostatic radar configuration. The method involves developing the Cramér-Rao lower bound (CRLB for a simplified model. The CRLB for model parameters are compared with simulation results using a grid-based approach for estimation. The CRLBs are within the 99% confidence intervals for all chosen parameter values. The CRLBs show an optimal region within an ellipsoid centered at 1 GHz center frequency and 1.25 GHz bandwidth with axes of 0.5 GHz and 1 GHz, respectively. Calculations show that emitted signal energy to received noise spectral density should exceed for a precision of approximately 0.1 mm for a large range of model parameters. This implies a minimum average power of 0.4  . These values are based on optimistic assumptions. Reflections, improved propagation model, true receiver noise, and parameter ranges should be considered in a practical implementation.

  1. Minimum Variance Signal Selection for Aorta Radius Estimation Using Radar

    Science.gov (United States)

    Solberg, LarsErik; Hamran, Svein-Erik; Berger, Tor; Balasingham, Ilangko

    2010-12-01

    This paper studies the optimum signal choice for the estimation of the aortic blood pressure via aorta radius, using a monostatic radar configuration. The method involves developing the Cramér-Rao lower bound (CRLB) for a simplified model. The CRLB for model parameters are compared with simulation results using a grid-based approach for estimation. The CRLBs are within the 99% confidence intervals for all chosen parameter values. The CRLBs show an optimal region within an ellipsoid centered at 1 GHz center frequency and 1.25 GHz bandwidth with axes of 0.5 GHz and 1 GHz, respectively. Calculations show that emitted signal energy to received noise spectral density should exceed [InlineEquation not available: see fulltext.] for a precision of approximately 0.1 mm for a large range of model parameters. This implies a minimum average power of 0.4 [InlineEquation not available: see fulltext.]. These values are based on optimistic assumptions. Reflections, improved propagation model, true receiver noise, and parameter ranges should be considered in a practical implementation.

  2. Ruptured Sinus of Valsalva Aneurysm and Coarctation of Aorta in a Woman at Early Postpartum Period

    Directory of Open Access Journals (Sweden)

    Erol Sener

    2014-01-01

    Full Text Available Coarctation of aorta and sinus of Valsalva aneurysm are frequently missed congenital cardiac defects that their diagnosis might be delayed. To our knowledge, coincidence of these cardiac defects is unusual and has not been reported in the literature before. Here, we present a patient with coarctation of aorta and ruptured noncoronary sinus of Valsalva aneurysm leading to aorto-right atrial fistula in the early postpartum period and our management of this unusual case.

  3. Migration of thoracic aorta after the anterior correction of thoracic idiopathic scoliosis without parietal pleura closure.

    Science.gov (United States)

    Zhu, Feng; Chen, Wen-jun; Wang, Wei-jun; Wang, Bing; Zhu, Ze-zhang; Zhu, Bin; Qiu, Yong

    2011-08-01

    To compare the preoperative and postoperative relative position of the thoracic aorta to the vertebrae in patients with idiopathic scoliosis (IS) after anterior corrective surgery without parietal pleura closure. To investigate the impact of unrepaired parietal pleura on thoracic aorta migration after anterior correction of right thoracic IS. Vascular injuries caused by vertebral screws have been reported in several studies. Recent studies showed an anteromedial shift of thoracic aorta after anterior curve correction with closure of the parietal pleura in thoracic IS. Migration of the aorta in patients with nonclosed parietal pleura has not been studied before, although it has been speculated in benefiting the transposition of the aorta and thus reduces the risk of vascular injury. Fifteen IS patients with predominant right thoracic scoliosis who underwent anterior instrumentation without parietal pleura closure were recruited for the study. There were 10 female and 5 male patients with an average age of 15.9 years. The following parameters were measured on preoperative and postoperative computed tomographic scans: angle α: aorta-vertebral angle; distance a: distance between the aorta and the left rib head; distance b: distance from aorta to vertebral body cortex. From computed tomographic measurements, the angle α from T5 to T12 ranged from 28.9 to 68.3 degrees before surgery and 18.8 to 63.2 degrees after surgery. The distance a ranged from 5.6 mm to 28.1 mm before surgery and 2.3 mm to 24.3 mm after surgery. The distance b ranged from 1.7 mm to 4.3 mm before surgery and 2.3 mm to 8.0 mm after surgery. These changes in all the parameters reached statistically significant difference at all the levels except in upper and lower end vertebrae (Ppleura closure.

  4. The anomalous origin of the branch pulmonary artery from the ascending aorta

    OpenAIRE

    Garg, Pankaj; Talwar, Sachin; Kothari, Shyam Sunder; Saxena, Anita; Juneja, Rajnish; Choudhary, Shiv Kumar; Airan, Balram

    2012-01-01

    The anomalous origin of one pulmonary artery branch from the aorta (AOPA) is rare. We report our single-institution surgical experience with this condition. Between January 1994 and February 2011, 17 patients (age: 1 month–25 years) with AOPA underwent surgery at our institute. Thirteen patients had an anomalous origin of the right pulmonary artery (RPA) while four had an anomalous origin of the left pulmonary artery (LPA) from the aorta. In patients with anomalous RPA, 11 patients had the pr...

  5. Tratamiento endovascular de la aorta torácica descendente. Tratamiento endovascular de la aorta torácica descendente.

    Directory of Open Access Journals (Sweden)

    Hernán G. Bertoni

    2007-01-01

    Full Text Available ObjetivoEl propósito de esta publicación es comunicar nuestros resultados inmediatos y a mediano plazo del tratamiento endovascular de la aorta torácica descendente mediante implante de endoprótesis.Material y métodosEntre agosto de 1999 y agosto de 2006, 74 pacientes consecutivos, 53 hombres y 21 mujeres, fueron tratados por vía endovascular con implante de una prótesis autoexpandible. La edad media fue de 60 ± 14,8 años. Las indicaciones para tratamiento fueron disección aguda (n = 8; 11%, disección crónica (n = 31; 42%, hematoma intramural (n = 5; 7%, aneurisma verdadero (n = 17; 23%, úlcerapenetrante (n = 4; 5% y seudoaneurisma traumático (n = 9; 12%.ResultadosEl implante del dispositivo fue exitoso en 73 (98,6% pacientes; no se requirió conversión quirúrgica en ninguno de ellos. Ningún paciente presentó paraplejía o déficit neurológico. La mortalidad a los 30 días fue del 8,1% (n = 6. La mediana de seguimiento fue de 33,5 meses (rango 1-79 y la sobrevida global fue del 84% (IC 69-92% y del 91% (IC 77-97%, según se incluyese o no la mortalidad temprana. El 93% (IC 84-97% de los pacientes estaban libres de complicaciones relacionadas con el procedimiento. La mayoría de las complicaciones ocurrieron durante el primer año de seguimiento.ConclusionesEl tratamiento endovascular de la aorta torácica descendente con implante de endoprótesis autoexpandible es factible y seguro. La baja incidencia de eventos en relación con las series quirúrgicas publicadas hace que este procedimiento sea de elección en pacientes seleccionados.

  6. Phantom limb pain from spinal sarcoma: a case report.

    Science.gov (United States)

    Cruz, Ernesto; Dangaria, Harsh T

    2013-07-01

    Phantom limb pain is a frequent sequela of amputation. A high prevalence of residual limb pain and back pain also exists among amputees. We present a case of a new-onset severe phantom limb pain resulting from a metastatic spinal mass in an 81-year-old patient with a history of malignant sarcoma and an old hip disarticulation amputation. The metastatic lesion, upon imaging, was found to involve the L3 vertebra and caused moderate compression of the thecal sac on the right and severe right lateral recess stenosis. After the mass was resected, the patient's phantom limb pain resolved. Our case report demonstrates that spinal metastatic pathologies may be a cause of phantom limb pain and should be included in the differential diagnosis of new-onset phantom limb pain or a change in phantom limb pain. Copyright © 2013 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  7. Development of thyroid anthropomorphic phantoms for use in nuclear medicine

    Science.gov (United States)

    Cerqueira, R. A. D.; Maia, A. F.

    2014-02-01

    The objective of this study was to develop thyroid anthropomorphic phantoms to be used in control tests of medical images in scintillation cameras. The main difference among the phantoms was the neck shape: in the first, called OSCT, it was geometrically shaped, while in the second, called OSAP, it was anthropomorphically shaped. In both phantoms, thyroid gland prototypes, which were made of acrylic and anthropomorphically shaped, were constructed to allow the simulation of a healthy thyroid and of thyroids with hyperthyroidism and hypothyroidism. Images of these thyroid anthropomorphic phantoms were obtained using iodine 131 with an activity of 8.695 MBq. The iodine 131 was chosen because it is widely used in studies of thyroid scintigraphy. The images obtained proved the effectiveness of the phantoms to simulate normal or abnormal thyroids function. These phantoms can be used in medical imaging quality control programs and, also in the training of professionals involved in the analysis of images in nuclear medicine centers.

  8. The value of anterior displacement of the abdominal aorta in diagnosing neuroblastoma in children

    Energy Technology Data Exchange (ETDEWEB)

    Schiavon, Jose Luiz de Oliveira; Caran, Eliana Maria Monteiro; Lederman, Henrique Manoel, E-mail: schiavon00@gmail.com [Universidade Federal de Sao Paulo (EPM/UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina; Odone Filho, Vicente [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina

    2016-11-15

    Objective: To determine the value of anterior displacement of the abdominal aorta, when present at any level or only at the level of the adrenal gland, contralateral to the mass, in diagnosing neuroblastoma on computed tomography or magnetic resonance imaging in children up to 7 years of age. Materials and Methods: Imaging examinations of 66 patients were classified by consensus as for the presence of anterior aorta displacement and were compared with the pathology report. Results: We found anterior abdominal aorta displacement in 26 (39.39%) of the 66 patients evaluated. Among those 26 patients, we identified neuroblastoma in 22 (84.62%), nephroblastoma in 3 (11.54%), and Burkitt lymphoma in 1 (3.85%). The positive predictive value was 84.62%, and the specificity was 88.24%. The displacement of the aorta was at the adrenal level, contralateral to the mass, in 14 cases, all of which were attributed to neuroblastoma. Conclusion: When the abdominal aorta is displaced at the level of the adrenal gland, contralateral to the mass, it can be said that the diagnosis is neuroblastoma, whereas abdominal aorta displacement occurring at other abdominal levels has a positive predictive value for neuroblastoma of approximately 85%. (author)

  9. The value of anterior displacement of the abdominal aorta in diagnosing neuroblastoma in children

    Directory of Open Access Journals (Sweden)

    Jose Luiz de Oliveira Schiavon

    Full Text Available Abstract Objective: To determine the value of anterior displacement of the abdominal aorta, when present at any level or only at the level of the adrenal gland, contralateral to the mass, in diagnosing neuroblastoma on computed tomography or magnetic resonance imaging in children up to 7 years of age. Materials and Methods: Imaging examinations of 66 patients were classified by consensus as for the presence of anterior aorta displacement and were compared with the pathology report. Results: We found anterior abdominal aorta displacement in 26 (39.39% of the 66 patients evaluated. Among those 26 patients, we identified neuroblastoma in 22 (84.62%, nephroblastoma in 3 (11.54%, and Burkitt lymphoma in 1 (3.85%. The positive predictive value was 84.62%, and the specificity was 88.24%. The displacement of the aorta was at the adrenal level, contralateral to the mass, in 14 cases, all of which were attributed to neuroblastoma. Conclusion: When the abdominal aorta is displaced at the level of the adrenal gland, contralateral to the mass, it can be said that the diagnosis is neuroblastoma, whereas abdominal aorta displacement occurring at other abdominal levels has a positive predictive value for neuroblastoma of approximately 85%.

  10. Evaluation of reconstruction parameters of electrical impedance tomography on aorta detection during saline bolus injection

    Directory of Open Access Journals (Sweden)

    Thürk Florian

    2016-09-01

    Full Text Available An accurate detection of anatomical structures in electrical impedance tomography (EIT is still at an early stage. Aorta detection in EIT is of special interest, since it would favor non-invasive assessment of hemodynamic processes in the body. Here, diverse EIT reconstruction parameters of the GREIT algorithm were systematically evaluated to detect the aorta after saline bolus injection in apnea. True aorta position and size were taken from computed tomography (CT. A comparison with CT showed that the smallest error for aorta displacement was attained for noise figure nf = 0.7, weighting radius rw = 0.15, and target size ts = 0.01. The spatial extension of the aorta was most precise for nf = 0.7, rw = 0.25, and ts = 0.07. Detection accuracy (F1-score was highest with nf = 0.6, rw = 0.15, and ts = 0.04. This work provides algorithm-related evidence for potentially accurate aorta detection in EIT after injection of a saline bolus.

  11. [Diagnostic value of transesophageal echocardiography in traumatic rupture of the thoracic aorta].

    Science.gov (United States)

    Vignon, P; Guéret, P; Lagrange, P; Laskar, M

    1994-06-01

    Traumatic rupture of the aorta (TRA) usually occurs at the isthmus. It is rapidly lethal without early surgery and, therefore, diagnosis must not be delayed. The reference diagnostic investigation is aortography but it is invasive in a patient with multiple trauma whose haemodynamic status is often precarious. Transoesophageal echocardiography, a non-invasive investigation which can be undertaken rapidly at the bedside has been proposed recently for the diagnosis of this condition because it gives excellent views of the aortic isthmus. The authors report their experience of transoesophageal echocardiography in 3 victims of severe road traffic accidents with thoracic trauma and who were operated for traumatic rupture of the aorta. Echocardiographic diagnosis of TRA is based on the recording of the association of a thick and mobile intraluminal echo corresponding to the torn intima and media and localised dilatation of the aorta, the wall of which is reduced to the adventitia under tension. On Doppler colour flow mapping the velocities are similar on both sides of the tear but turbulence at the site of rupture may give rise to aliasing. It is important to recognise the echocardiographic features of TRA to differentiate it from dissection of the aorta. Transoesophageal echocardiography also allows diagnosis of any associated traumatic cardiovascular lesions. Its limitations are due to the inability to visualise the proximal portion of the transverse aorta and the supra aortic vessels. Aortography remains essential when a lesion of these vessels is suspected and when the echocardiographic features of the aorta are atypical.

  12. Vanadyl sulfate protects against streptozotocin-induced morphological and biochemical changes in rat aorta.

    Science.gov (United States)

    Akgün-Dar, Kadriye; Bolkent, Sehnaz; Yanardag, Refiye; Tunali, Sevim

    2007-01-01

    The aim of this study was to investigate the protective effects of vanadyl sulfate on aorta tissue of normal and streptozotocin (STZ)-induced diabetic rats, morphologically and biochemically. The animals were made diabetic by an intraperitoneal injection of streptozotocin (65 mg/kg) and vanadyl sulfate (100 mg/kg) that was given every day for 60 days by gavage technique to rats. Under the light and transmission electron microscopes, hypertrophy of the vessel wall, focal disruption in the elastic lamellae, an increase in thickness of total aortic wall, tunica intima, subendothelial space and adventitial layer, and a disorganization in smooth muscular cells of the tunica media were observed in diabetic animals. The aorta lipid peroxidation (LPO) levels were significantly increased and the aorta glutathione (GSH) levels were significantly reduced in STZ diabetic rats. In diabetic rats administered vanadyl sulfate for 60 days, aorta LPO levels significantly decreased and the aorta GSH level significantly increased. In conclusion, in vivo treatment with vanadyl sulfate of diabetic rats prevented the morphological and biochemical changes observed in thoracic aorta of diabetic animals. Copyright (c) 2006 John Wiley & Sons, Ltd.

  13. Detection of histidine decarboxylase in rat aorta and cultured rat aortic smooth muscle cells.

    Science.gov (United States)

    Tippens, A S; Davis, S V; Hayes, J R; Bryda, E C; Green, T L; Gruetter, C A

    2004-08-01

    Having previously demonstrated release of histamine from mast-cell-deficient rat aorta, the objective of this study was to determine and localize histamine synthesis capability in the aorta by detecting histidine decarboxylase (HDC), the enzyme that catalyzes histamine formation. Experiments were conducted with nested reverse transcription-polymerase chain reaction (nRT-PCR) to detect HDC mRNA and with immunofluorescence and western blot analysis to detect HDC protein in rat aorta, cultured rat aortic smooth muscle (RASMC) and endothelial cells (RAEC). Gel electrophoresis of nRT-PCR products indicated HDC mRNA in liver, aorta and RASMC but not in RAEC or kidney. Sequence analysis confirmed that the band observed in RASMC was the target HDC amplicon. Immunofluorescence indicated the presence of HDC protein in RASMC and not in RAEC. Western Blot analysis revealed HDC protein (55 kDa) in liver, aorta, RASMC but not in RAEC or kidney. The results of this study are the first to demonstrate the presence of HDC mRNA and protein in rat aorta and more specifically in RASMC, indicative of their capability to synthesize histamine. Copyright 2004 Birkhäuser Verlag, Basel

  14. Calibrating pen dosimeters with and without a phantom

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda B.C.; Cescon, Claudinei T.; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: ctcescon@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Thirty one direct reading dosimeters (pen dosimeters) were calibrated and tested in standard beams of gamma radiation, with and without the use of a phantom. The calibration was performed with a Co-60 source and tested with a Cs-137 source. The dose-response curves of the pen dosimeters and their calibration factors for a Co-60 source, with and without the use of a phantom were obtained. The results show the need to calibrate the pen dosimeters with a phantom. (author)

  15. Creating 3D gelatin phantoms for experimental evaluation in biomedicine

    Directory of Open Access Journals (Sweden)

    Stein Nils

    2015-09-01

    Full Text Available We describe and evaluate a setup to create gelatin phantoms by robotic 3D printing. Key aspects are the large workspace, reproducibility and resolution of the created phantoms. Given its soft tissue nature, the gelatin is kept fluid during inside the system and we present parameters for additive printing of homogeneous, solid objects. The results indicate that 3D printing of gelatin can be an alternative for quickly creating larger soft tissue phantoms without the need for casting a mold.

  16. Ramos colaterais parietais e terminais da aorta abdominal em Myocastor coypus (nutria Terminal and parietal colateral branches of the abdominal aorta in Myocastor coypus (nutria

    Directory of Open Access Journals (Sweden)

    Paulete de Oliveira Vargas Culau

    2008-08-01

    Full Text Available Neste estudo, utilizaram-se 30 nutrias, 15 fêmeas e 15 machos, com o sistema arterial aórtico-abdominal preenchido com látex 603, pigmentado em vermelho, e fixado em uma solução aquosa de formaldeído a 20%. A aorta abdominal emitiu de sua superfície dorsal de 6 a 8 artérias lombares únicas. Das artérias renais, direita e esquerda, originaram-se as artérias frênico-abdominal para irrigar parte do diafragma e da parede abdominal lateral cranial. A aorta abdominal lançou dorsalmente, a artéria sacral mediana, cranialmente a sua bifurcação em artérias ilíacas comuns. As artérias ilíacas comuns, ramos terminais da aorta abdominal, originaram as artérias ilíacas interna e externa. A artéria ilíaca interna distribuiu-se nas vísceras da cavidade pélvica. A artéria ilíaca externa emitiu uma artéria umbilical e, antes de alcançar o anel femoral, lançou a artéria circunflexa ilíaca profunda para a parede abdominal lateral, em seus dois terços caudais. A artéria ilíaca externa lançou o tronco pudendo-epigástrico, que originou a artéria epigástrica caudal, para a parede abdominal ventral e a artéria pudenda externa, que saiu pelo canal inguinal, para irrigar a genitália externa. Os ramos parietais diretos da aorta abdominal foram as artérias lombares e a artéria sacral mediana, enquanto as artérias frênico-abdominal, circunflexa ilíaca profunda e epigástrica caudal, foram ramos colaterais parietais indiretos. Os ramos terminais da artéria aorta abdominal foram as artérias ilíacas comuns com seus ramos, as artérias ilíacas interna e externa.For this study it was used 30 nutria, 15 females and 15 males, with its abdominal aorta system full filled with latex 603, stained in red, and fixed in an aqueous solution of formaldehyde 20%. The abdominal aorta emitted from its dorsal surface 6 to 8 single lumbar arteries. From the renal arteries, left and right, it has been originated the phrenicoabdominal arteries

  17. Indigo carmine enhances phenylephrine-induced contractions in an isolated rat aorta.

    Science.gov (United States)

    Choi, Yun Suk; Ok, Seong-Ho; Lee, Seung Min; Park, Sang-Seung; Ha, Yu Mi; Chang, Ki Churl; Kim, Hye Jung; Shin, Il-Woo; Sohn, Ju-Tae

    2011-07-01

    The intravenous administration of indigo carmine has been reported to produce transiently increased blood pressure in patients. The goal of this in vitro study was to examine the effect of indigo carmine on phenylephrine-induced contractions in an isolated rat aorta and to determine the associated cellular mechanism with particular focus on the endothelium-derived vasodilators. The concentration-response curves for phenylephrine were generated in the presence or absence of indigo carmine. Phenylephrine concentration-response curves were generated for the endothelium-intact rings pretreated independently with a nitric oxide synthase inhibitor, N(ω)-nitro-L-arginine methyl ester (L-NAME), a cyclooxygenase inhibitor, indomethacin, and a low-molecular-weight superoxide anion scavenger, tiron, in the presence or absence of indigo carmine. The fluorescence of oxidized dichlorofluorescein was measured in rat aortic vascular smooth muscle cells cultured in the control, indigo carmine alone and tiron plus indigo carmine. Indigo carmine (10(-5) M) increased the phenylephrine-induced maximum contraction in the endothelium-intact rings with or without indomethacin, whereas indigo carmine produced a slight leftward shift in the phenylephrine concentration-response curves in the endothelium-denuded rings and L-NAME-pretreated endothelium-intact rings. In the endothelium-intact rings pretreated with tiron (10(-2) M), indigo carmine did not alter phenylephrine concentration-response curves significantly. Indigo carmine (10(-5) M) increased the fluorescence of oxidized dichlorofluorescein in the vascular smooth muscle cells, whereas tiron abolished the indigo carmine-induced increase in oxidized dichlorofluorescein fluorescence. Indigo carmine increases the phenylephrine-induced contraction mainly through an endothelium-dependent mechanism involving the inactivation of nitric oxide caused by the increased production of reactive oxygen species.

  18. Dynamics of coupled phantom and tachyon fields

    Energy Technology Data Exchange (ETDEWEB)

    Shahalam, M. [Zhejiang University of Technology, Institute for Advanced Physics and Mathematics, Hangzhou (China); Pathak, S.D.; Li, Shiyuan [Shandong University, School of Physics, Jinan (China); Myrzakulov, R. [Eurasian National University, Department of General and Theoretical Physics, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Wang, Anzhong [Zhejiang University of Technology, Institute for Advanced Physics and Mathematics, Hangzhou (China); Baylor University, Department of Physics, GCAP-CASPER, Waco, TX (United States)

    2017-10-15

    In this paper, we apply the dynamical analysis to a coupled phantom field with scaling potential taking particular forms of the coupling (linear and combination of linear), and present phase space analysis. We investigate if there exists a late time accelerated scaling attractor that has the ratio of dark energy and dark matter densities of the order one. We observe that the scrutinized couplings cannot alleviate the coincidence problem, however, they acquire stable late time accelerated solutions. We also discuss a coupled tachyon field with inverse square potential assuming linear coupling. (orig.)

  19. Getting started with PhantomJS

    CERN Document Server

    Beltran, Aries

    2013-01-01

    The book will follow aA standard tutorial approach, and will beas a complete guide detailing the major aspects of PhantomJS with particular focus on Website website Testingtesting.This book is written forIf you are a JavaScript developers who are is interested in developing applications that interact with various web services, and doing that using a headless browser, then this book is ideal for you. This book iswill also be good for you if you are planning to create a headless browser testing for your web application. Basic understanding of JavaScript is assumed.

  20. [Residual limb and phantom pain : Causes and therapeutic approaches].

    Science.gov (United States)

    Dwornik, G; Weiß, T; Hofmann, G O; Brückner, L

    2015-06-01

    Residual limb pain and phantom pain are severe complications following an amputation. Various reasons are responsible for these complaints. It must be distinguished between amputation stump pain, phantom sensations and phantom pain. In this paper we describe the most common reasons for stump pain and propose some non-operative therapeutic approaches. Furthermore path physiology and phantom pain therapy will be discussed. The recommendations offered in this paper are based on practical experience over three decades in a specialized out-patient department for patients with amputation injuries.

  1. [Phantom limb after amputation--overview and new knowledge].

    Science.gov (United States)

    Schmid, H J

    2000-01-13

    Almost all patients who have an extremity amputated will experience a phantom limb. Amputations of other parts of the body can also cause phantom sensations. One fourth of all women who undergo mastectomy relates phantom breast sensations. Phantoms are common following rectum amputation and may be significant as indicators of rectal tumor relapse. Visual phantoms can appear in patients who undergo eye amputation. Phantom phenomena occur after tooth extraction, ureterocystectomy, penectomy, plexus avulsion or spinal cord injury. The causes underlying phantom sensations are unknown. Sensory deprivation in animals causes reorganization of the cortical and subcortical maps: the areas representing the deprived input shrink and the neighbouring areas expand. The mapping allocates areas to represent the most used peripheral inputs. Every level of the nervous system seems to exhibit plasticity. The primary site seems to be the cortex. The cellular basis of plasticity is unclear. Significant sensory and motor reorganization was found in humans suffering phantom pain. There was a strong relationship between the amount of cortical reorganization and the intensity of phantom pain. These findings may influence the rehabilitation of the amputee. It was shown that pain and cortical reorganization can be reduced or even prevented by the active use of prostheses.

  2. Phantom Extremity Pain Responding to Stellate Ganglion Blockage: Case Report

    Directory of Open Access Journals (Sweden)

    Edip Gonullu

    2013-04-01

    Full Text Available Phantom extremity pain is that which continues to be felt in a non-existent extremity after amputation. The pathophysiological mechanism and etiology of phantom extremity pain are not exactly known, Phantom extremity pain affects the patients in physical and psycho-social aspects. This paper presents a patient with phantom extremity pain that had not responded to medical treatment. A stellate ganglion blockage was performed using lidocaine, bupivacaine and fentanyl and the patient%u2019s pain was observed to be reduced.

  3. Phantom Eye Syndrome: A Review of the Literature

    Directory of Open Access Journals (Sweden)

    Agda M. Andreotti

    2014-01-01

    Full Text Available The purpose of this literature review was to describe the main features of phantom eye syndrome in relation to their possible causes, symptoms, treatments, and influence of eye amputation on quality of life of anophthalmic patients. For this, a bibliographical research was performed in Pubmed database using the following terms: “eye amputation,” “eye trauma,” “phantom eye syndrome,” “phantom pain,” and “quality of life,” associated or not. Thirteen studies were selected, besides some relevant references contained in the selected manuscripts and other studies hallowed in the literature. Thus, 56 articles were included in this review. The phantom eye syndrome is defined as any sensation reported by the patient with anophthalmia, originated anophthalmic cavity. In phantom eye syndrome, at least one of these three symptoms has to be present: phantom vision, phantom pain, and phantom sensations. This syndrome has a direct influence on the quality of life of the patients, and psychological support is recommended before and after the amputation of the eyeball as well as aid in the treatment of the syndrome. Therefore, it is suggested that, for more effective treatment of phantom eye syndrome, drug therapy should be associated with psychological approach.

  4. Multi-layered tissue head phantoms for noninvasive optical diagnostics

    Directory of Open Access Journals (Sweden)

    M. S. Wróbel

    2015-05-01

    Full Text Available Extensive research in the area of optical sensing for medical diagnostics requires development of tissue phantoms with optical properties similar to those of living human tissues. Development and improvement of in vivo optical measurement systems requires the use of stable tissue phantoms with known characteristics, which are mainly used for calibration of such systems and testing their performance over time. Optical and mechanical properties of phantoms depend on their purpose. Nevertheless, they must accurately simulate specific tissues they are supposed to mimic. Many tissues and organs including head possess a multi-layered structure, with specific optical properties of each layer. However, such a structure is not always addressed in the present-day phantoms. In this paper, we focus on the development of a plain-parallel multi-layered phantom with optical properties (reduced scattering coefficient $\\mu_{s}^{\\prime}$ and absorption coefficient μa corresponding to the human head layers, such as skin, skull, and gray and white matter of the brain tissue. The phantom is intended for use in noninvasive diffuse near-infrared spectroscopy (NIRS of human brain. Optical parameters of the fabricated phantoms are reconstructed using spectrophotometry and inverse adding-doubling calculation method. The results show that polyvinyl chloride-plastisol (PVCP and zinc oxide (ZnO nanoparticles are suitable materials for fabrication of tissue mimicking phantoms with controlled scattering properties. Good matching was found between optical properties of phantoms and the corresponding values found in the literature.

  5. [Gelatine phantom for training of ultrasound guided vascular access].

    Science.gov (United States)

    Clemmesen, Louise; Bendtsen, Thomas F; Sloth, Erik; Oveland, Nils Petter; Knudsen, Lars

    2013-02-25

    This article describes the production of a low-cost training phantom for ultrasound guided invasive procedures of peripheral and central veins and presents a video of the process. The phantom can be adapted for use with other ultrasound techniques. It is a universal useful skill training tool for ultrasound guided invasive procedures. The phantom is easily made of concentrated gelatine. It is cheap and recyclable. The shelf life is prolonged by cold storage in a freezer. The gelatine phantom is a useful tool for practice of probe handling techniques and needle dexterity when placing peripheral and central venous catheters.

  6. [Development of a software for 3D virtual phantom design].

    Science.gov (United States)

    Zou, Lian; Xie, Zhao; Wu, Qi

    2014-02-01

    In this paper, we present a 3D virtual phantom design software, which was developed based on object-oriented programming methodology and dedicated to medical physics research. This software was named Magical Phan tom (MPhantom), which is composed of 3D visual builder module and virtual CT scanner. The users can conveniently construct any complex 3D phantom, and then export the phantom as DICOM 3.0 CT images. MPhantom is a user-friendly and powerful software for 3D phantom configuration, and has passed the real scene's application test. MPhantom will accelerate the Monte Carlo simulation for dose calculation in radiation therapy and X ray imaging reconstruction algorithm research.

  7. Phantom Limb Sensation (PLS) and Phantom Limb Pain (PLP) among Young Landmine Amputees.

    Science.gov (United States)

    Poor Zamany Nejatkermany, Mahtab; Modirian, Ehsan; Soroush, Mohammadreza; Masoumi, Mehdi; Hosseini, Maryam

    2016-01-01

    To determine the frequency of phantom limb sensation (PLS) and phantom limb pain (PLP) in children and young adults suffering landmine-related amputation. All youths with amputation due to landmine explosions participated in this study. The proportions of patients with phantom limb sensation/pain, intensity and frequency of pain were reported. Chi square test was used to examine the relationship between variables. Comparison of PLP and PLS between upper and lower amputation was done by unpaired t-test. There were 38 male and 3 female with the mean age of 15.8±2.4yr. The mean interval between injury and follow-up was 90.7±39.6 months. Twelve (44.4%) upper limb amputees and 11 (26.8%) lower limb amputees had PLS. Nine (33.3%) upper limb amputees and 7 (17.1%) lower limb amputees experienced PLP. Of 27 upper limb amputees, 6 (14.6%) and among 15 lower limb amputees, 6 (14.6%) had both PLS and PLP. One case suffered amputation of upper and lower limbs and was experiencing PLS and PLP in both parts. PLS had a significant difference between the upper and lower amputated groups. Significant relationship was observed between age of casualty and duration of injury with PLP. Phantom limb sensation and pain in young survivors of landmine explosions appear to be common, even years after amputation.

  8. Stenosis of the thoracic aorta in Williams syndrome.

    Science.gov (United States)

    Collins, R Thomas; Kaplan, Paige; Rome, Jonathan J

    2010-08-01

    Williams syndrome (WS) is a multisystem congenital disorder affecting 1/8000 live births. Our objective was to review our experience with stenosis of the thoracic aorta (STA) in these patients. A retrospective review was undertaken of consecutive WS patients at The Children's Hospital of Philadelphia from January 1, 1980, through December 31, 2007. WS was diagnosed by an experienced medical geneticist and/or by fluorescence in situ hybridization. Stenosis was diagnosed with either echocardiography or cardiac catheterization. Freedom from intervention was determined using Kaplan-Meier analysis. From a total cohort of 270 patients, 37 (14%) patients with STA were identified and comprised the study group. Age at presentation was 2.1 + or - 4.0 years, and follow-up was 11.8 + or - 12.6 years (range 0-51). Long-segment STA was more common (89%) than discrete STA. Severity of STA was mild in 18, moderate in 10, and severe in 9 patients. Branch pulmonary artery stenosis was seen in 62% (23 of 37) of STA patients, and supravalvar aortic stenosis was seen in 54% (20 of 37) STA patients. Nine (24%) patients underwent intervention for STA: 8 cases were severe, and 1 case was moderate. Restenosis resulting in reintervention occurred in 5 of 9 (56%) patients, with 4 of 5 (80%) patients undergoing multiple reinterventions. Freedom from intervention was 89, 82, and 73% at 1, 5, and 20 years, respectively. One patient died. STA is common in WS and is generally the long-segment type. In patients with STA, interventions are common and usually occur by 5 years of age. Reintervention for STA occurs frequently.

  9. Dual Energy Tomosynthesis breast phantom imaging

    Science.gov (United States)

    Koukou, V.; Martini, N.; Fountos, G.; Messaris, G.; Michail, C.; Kandarakis, I.; Nikiforidis, G.

    2017-12-01

    Dual energy (DE) imaging technique has been applied to many theoretical and experimental studies. The aim of the current study is to evaluate dual energy in breast tomosynthesis using commercial tomosynthesis system in terms of its potential to better visualize microcalcifications (μCs). The system uses a tungsten target X-ray tube and a selenium direct conversion detector. Low-energy (LE) images were acquired at different tube voltages (28, 30, 32 kV), while high-energy images at 49 kV. Fifteen projections, for the low- and high-energy respectively, were acquired without grid while tube scanned continuously. Log-subtraction algorithm was used in order to obtain the DE images with the weighting factor, w, derived empirically. The subtraction was applied to each pair of LE and HE slices after reconstruction. The TORMAM phantom was imaged with the different settings. Four regions-of-interest including μCs were identified in the inhomogeneous part of the phantom. The μCs in DE images were more clearly visible compared to the low-energy images. Initial results showed that DE tomosynthesis imaging is a promising modality, however more work is required.

  10. Phantom black holes and critical phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Azreg-Aïnou, Mustapha [Engineering Faculty, Başkent University, Bağlıca Campus, Ankara (Turkey); Marques, Glauber T. [Universidade Federal Rural da Amazônia ICIBE-LASIC, Av. Presidente Tancredo Neves 2501, CEP 66077-901—Belém/PA (Brazil); Rodrigues, Manuel E., E-mail: azreg@baskent.edu.tr, E-mail: gtadaiesky@hotmail.com, E-mail: esialg@gmail.com [Faculdade de Ciências Exatas e Tecnologia, Universidade Federal do Pará, Campus Universitário de Abaetetuba, CEP 68440-000, Abaetetuba, Pará (Brazil)

    2014-07-01

    We consider the two classes cosh and sinh of normal and phantom black holes of Einstein-Maxwell-dilaton theory. The thermodynamics of these holes is characterized by heat capacities that may have both signs depending on the parameters of the theory. Leaving aside the normal Reissner-Nordström black hole, it is shown that only some phantom black holes of both classes exhibit critical phenomena. The two classes share a nonextremality, but special, critical point where the transition is continuous and the heat capacity, at constant charge, changes sign with an infinite discontinuity. This point yields a classification scheme for critical points. It is concluded that the two unstable and stable phases coexist on one side of the criticality state and disappear on the other side, that is, there is no configuration where only one phase exists. The sinh class has an extremality critical point where the entropy diverges. The transition from extremality to nonextremality with the charge held constant is accompanied by a loss of mass and an increase in the temperature. A special case of this transition is when the hole is isolated (microcanonical ensemble), it will evolve by emission of energy, which results in a decrease of its mass, to the final state of minimum mass and vanishing heat capacity. The Ehrenfest scheme of classification is inaccurate in this case but the generalized one due to Hilfer leads to conclude that the transition is of order less than unity. Fluctuations near criticality are also investigated.

  11. MRI compatible head phantom for ultrasound surgery.

    Science.gov (United States)

    Menikou, Georgios; Dadakova, Tetiana; Pavlina, Matt; Bock, Michael; Damianou, Christakis

    2015-03-01

    Develop a magnetic resonance imaging (MRI) compatible head phantom with acoustic attenuation closely matched to the human attenuation, and suitable for testing focused ultrasound surgery protocols. Images from an adult brain CT scan were used to segment the skull bone from adjacent cerebral tissue. The segmented model was manufactured in a 3-D printer using (Acrylonitrile Butadiene Styrene) ABS plastic. The cerebral tissue was mimicked by an agar-evaporated milk-silica gel (2% w/v-25% v/v-1.2% w/v) which was molded inside a skull model. The measured attenuation of the ABS skull was 16 dB/cm MHz. The estimated attenuation coefficient of the gel replicating brain tissue was 0.6 dB/cm MHz. The estimated agar-silica gel's T1 and T2 relaxation times in a 1.5 Tesla magnetic field were 852 ms and 66 ms respectively. The effectiveness of the skull to reduce ultrasonic heating was demonstrated using MRI thermometry. Due to growing interest in using MRI guided focused ultrasound (MRgFUS) for treating brain cancer and its application in sonothrombolysis, the proposed head phantom can be utilized as a very useful tool for evaluating ultrasonic protocols, thus minimizing the need for animal models and cadavers. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. [Atypical odontalgia - a little known phantom pain].

    Science.gov (United States)

    Türp, J C

    2001-02-01

    Atypical odontalgia (AO) was described in the dental literature more than 200 years ago, and it is included in most taxonomies and textbooks of pain. Nonetheless, it remains one of the most frequently misdiagnosed intraoral pain conditions. Due to similarities with phantom pain, AO is also referred to as "phantom tooth pain". AO is characterized by persistent throbbing pain in or around a former or present permanent tooth (preferably molars and premolars). Clinical and radiographic examination, however, does not reveal any organic cause of the pain. The complaints associated with AO usually begin after deafferentiation of primary afferent trigeminal nerve fibers, e. g., after pulp extirpation, apicectomy, or extraction of a tooth. AO is a diagnosis by exclusion. Patients and dentists must be aware of the fact that the therapeutic options are limited. AO is primarily managed with topically or systemically administered pharmacological agents. Unnecessary and harmful procedures around teeth and jaws must be avoided by all means. A concept was recently proposed which aims to unify a group of four types of orofacial pain under the term "idiopathic orofacial pain" (Woda & Pionchon 1999, 2000). These pain conditions - AO, atypical facial pain, burning mouth syndrome ("stomatodynia"), and subgroups of temporomandibular disorders ("idiopathic facial arthromyalgia") - are characterized by unknown etiology, but common clinical characteristics. It is to be hoped that the suggested classification will stimulate reflection on these enigmatic orofacial pain disorders.

  13. Generation of voxelized breast phantoms from surgical mastectomy specimens.

    Science.gov (United States)

    O'Connor, J Michael; Das, Mini; Dider, Clay S; Mahd, Mufeed; Glick, Stephen J

    2013-04-01

    In the research and development of dedicated tomographic breast imaging systems, digital breast object models, also known as digital phantoms, are useful tools. While various digital breast phantoms do exist, the purpose of this study was to develop a realistic high-resolution model suitable for simulating three-dimensional (3D) breast imaging modalities. The primary goal was to design a model capable of producing simulations with realistic breast tissue structure. The methodology for generating an ensemble of digital breast phantoms was based on imaging surgical mastectomy specimens using a benchtop, cone-beam computed tomography system. This approach allowed low-noise, high-resolution projection views of the mastectomy specimens at each angular position. Reconstructions of these projection sets were processed using correction techniques and diffusion filtering prior to segmentation into breast tissue types in order to generate phantoms. Eight compressed digital phantoms and 20 uncompressed phantoms from which an additional 96 pseudocompressed digital phantoms with voxel dimensions of 0.2 mm(3) were generated. Two distinct tissue classification models were used in forming breast phantoms. The binary model classified each tissue voxel as either adipose or fibroglandular. A multivalue scaled model classified each tissue voxel as percentage of adipose tissue (range 1%-99%). Power spectral analysis was performed to compare simulated reconstructions using the breast phantoms to the original breast specimen reconstruction, and fits were observed to be similar. The digital breast phantoms developed herein provide a high-resolution anthropomorphic model of the 3D uncompressed and compressed breast that are suitable for use in evaluating and optimizing tomographic breast imaging modalities. The authors believe that other research groups might find the phantoms useful, and therefore they offer to make them available for wider use.

  14. Evaluation of the normal thoracic and abdominal aorta diameters by computerized tomography; Avaliacao dos diametros normais da aorta toracica e abdominal pela tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Lucarelli, Claudio Luiz

    1995-07-01

    The study was undertaken to evaluate, through computerized tomography, the diameters of the normal thoracic and abdominal aorta, as well as they are connected to gender, age and body surface area; and the ratio between measurements obtained at the ascending and descending limbs of the thoracic aorta, and between the abdominal aortic diameters. For that reason, we measured the widest anteroposterior diameters of the thoracic aortas at the levels of the arch, the root, the pulmonary artery, and the thoracic-abdominal transition, as well as the level of the emergence of the superior mesenteric artery, of the renal hila and just cephalad to the bifurcation of the abdominal aortas of 350 patients without cardiovascular diseases who had undergone computerized tomography of the thorax and/or abdomen for any other reasons. Observation and statistic analyses led us to conclude that: 1) both the thoracic and abdominal aortic diameters are reduced from their proximal to their distal portions; 2) the body surface influences the size of the aorta, although only extreme variations alter the vessel's caliber; 3) vessel diameter was observed to gradually increase with age; 4) men were found to have larger diameters than age matched women; 5) the ratio between the ascending and descending aortic diameters varies according to gender and age; 6) the relations between abdominal aortic diameters measured at the level of renal hila and cephalad to the bifurcation are independent from gender and age. But the relation between those measured at the level of the superior mesenteric artery and cephalad to the bifurcation are linked to gender, but not to age. (author)

  15. Abdominal aorta coarctation: The first three case reports in our literature

    Directory of Open Access Journals (Sweden)

    Gajin Predrag

    2010-01-01

    Full Text Available Introduction. Congenital coarctation of the thoracic aorta at the ligamentum arteriosum or the aortic arch is well recognized. But a much less common variety (0.5-2.0% of aortic coarctation is located in the distal thoracic aorta or abdominal aorta or both and is often called 'middle aortic syndrome' or 'midaortic dysplastic syndrome'. This represents serious pathological condition and indicates multidisciplinary therapy approach. Outline of Cases. From 1996 to 2007, at the Vascular Surgery Clinic of the Institute for Cardiovascular Diseases 'Dedinje', Belgrade, three patients were treated due to abdominal aorta coarctation, two females aged 55 and 50 and a 4-year-old child. The patients were treated surgically (by-pass with a prosthetic graft and patch angioplasty and endovascular-percutaneous transluminal angioplasty (PTA with and without a stent. The follow-up period was 3-70 months. In the 50-year-old patient, angiography showed severe narrowing of the suprarenal segment of the abdominal aorta. Thoraco-abdominal bypass with a 16 mm dacronic tubular graft was performed. In the 4-year-old patient angiography also showed a suprarenal aorta narrowing. In the first act patch angioplasty was performed and after PTA of the visceral arteries was done on several occasions. In the 55-year-old patient, after diagnostic angiography, infrarenal aorta coarctation was registered. PTA was performed with stent placement. All patients were asymptomatic on control check-ups. Conclusion. Abdominal coarctation is a pathological disease which is seldom found in vascular surgery. Angiography is of major importance for setting the diagnosis and for the control of the results of surgical and nonsurgical treatment. The combination of surgical and endovascular treatment in our patients showed very good results in the studied period.

  16. Effects of nesfatin-1 on atrial contractility and thoracic aorta reactivity in male rats.

    Science.gov (United States)

    Barutcigil, Ayşe; Tasatargil, Arda

    2017-10-13

    This study aimed to examine the effects of nesfatin-1 on thoracic aorta vasoreactivity and to investigate the inotropic and chronotropic effects of nesfatin-1 on the spontaneous contractions of the isolated rat atria. Isolated right atria and thoracic aorta were used in organ baths. The reactivity of the thoracic aorta was evaluated by potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP). The effects of nesfatin-1 on the spontaneous contractions of the rat atria were also examined. Nesfatin-1 (0.1-100 ng/ml) produced a concentration-dependent relaxation response in rat thoracic aorta. The relaxant responses to nesfatin-1 were inhibited by the removal of endothelium, NO synthase blocker N-nitro-L-arginine methyl ester (L-NAME, 10-4 M), and soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10-5 M). Nesfatin-1 (10 ng/ml, 30 min) increased the relaxation responses to either ACh or SNP, and the contractile response to both Phe and KCl did not significantly change in the arteries that were incubated with nesfatin-1 compared with the controls. The thoracic aorta contractions induced by the stepwise addition of Ca2+ to a high KCl solution with no Ca2+ were not significantly changed by nesfatin-1. Under calcium-free conditions, the contractions of the thoracic aorta rings incubated with nesfatin-1 in response to Phe were not significantly lower than those of the rings from the control rats. Nesfatin-1 showed positive inotropic and chronotropic effects on rat atria. Nesfatin-1 significantly changed the vascular responsiveness in rat thoracic aorta and produced positive inotropic and chronotropic effects on rat atria.

  17. Ruptura traumática de la aorta descendente torácica Traumatic ruptura of the descending thoracic aorta

    Directory of Open Access Journals (Sweden)

    Gabriel González Sosa

    2013-03-01

    Full Text Available Los traumatismos torácicos graves (TT, ya sean abiertos o cerrados, pueden ocurrir secundarios a lesiones por arma de fuego, arma blanca, accidentes de tránsito, caídas de altura o compresiones torácicas por aplastamientos, entre otros y se han transformado en una causa importante de morbilidad y mortalidad, pero son las lesiones vasculares directamente responsables de un 20 a un 25 % del total de las muertes, causadas por estos traumatismos. La mayoría de los afectados por estas lesiones son personas jóvenes previamente sanas, fundamentalmente del sexo masculino. Se presenta un caso clínico de un paciente de 38 años de edad, con antecedentes de salud previos, que durante una riña, sufrió una herida en la región posterior del hemitórax derecho, por debajo del borde inferior de la escápula, penetrante en la cavidad torácica, ocasionada por un objeto corto punzante de fabricación artesanal, cuyo pedazo quedó dentro de esta cavidad, lo cual provocó una lesión de alrededor de 3 cm de longitud, aproximadamente a nivel de la aorta descendente torácica. El paciente fue intervenido quirúrgicamente de manera urgente, y se logró suturar la lesión vascular con éxito, proceder que casi nunca es posible debido al alto índice de mortalidad de este tipo de lesiones, pues la mayoría de las personas fallecen antes de su llegada a un centro especializado de salud.Severe thoracic traumatisms, either open or close, may occur secondary to injuries caused by firearms, knifes, traffic accidents, falls from height or thoracic compression due to crushing, among others. They have become an important cause of mortality and morbidity but they are vascular injuries directly responsible for 20 to 25 % of the total number of deaths caused by this type of traumatism. Most of the injuries occurred in healthy young people, mainly men. This is the case of a 38 years-old patient with a history of health problems, who in a street fight, suffered an injury

  18. 21 CFR 892.1950 - Radiographic anthropomorphic phantom.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1950 Radiographic anthropomorphic phantom. (a) Identification. A radiographic anthropomorphic phantom is a device intended for medical... (general controls). The device is exempt from the premarket notification procedures in subpart E of part...

  19. Mapping phantom movement representations in the motor cortex of amputees.

    Science.gov (United States)

    Mercier, Catherine; Reilly, Karen T; Vargas, Claudia D; Aballea, Antoine; Sirigu, Angela

    2006-08-01

    Limb amputation results in plasticity of connections between the brain and muscles, with the cortical motor representation of the missing limb seemingly shrinking, to the presumed benefit of remaining body parts that have cortical representations adjacent to the now-missing limb. Surprisingly, the corresponding perceptual representation does not suffer a similar fate but instead persists as a phantom limb endowed with sensory and motor qualities. How can cortical reorganization after amputation be reconciled with the maintenance of a motor representation of the phantom limb in the brain? In an attempt to answer this question we explored the relationship between the cortical representation of the remaining arm muscles and that of phantom movements. Using transcranial magnetic stimulation (TMS) we systematically mapped phantom movement perceptions while simultaneously recording stump muscle activity in three above-elbow amputees. TMS elicited sensations of movement in the phantom hand when applied over the presumed hand area of the motor cortex. In one subject the amplitude of the perceived movement was positively correlated with the intensity of stimulation. Interestingly, phantom limb movements that the patient could not produce voluntarily were easily triggered by TMS, suggesting that the inability to voluntarily move the phantom is not equivalent to a loss of the corresponding movement representation. We suggest that hand movement representations survive in the reorganized motor area of amputees even when these cannot be directly accessed. The activation of these representations is probably necessary for the experience of phantom movement.

  20. Anisotropic Bianchi-I universe with phantom field and cosmological ...

    Indian Academy of Sciences (India)

    We study an anisotropic Bianchi-I universe in the presence of a phantom field and a cosmological constant. Cosmological solutions are obtained when the kinetic energy of the phantom field is of the order of anisotropy and dominates over the potential energy of the field. The anisotropy of the universe decreases and the ...

  1. Cosmological model of interacting phantom and Yang–Mills fields

    Indian Academy of Sciences (India)

    interacting with a phantom field in FRW cosmology. Using the specific solution of YM equation previously considered in FRW cosmology [30–34], we generalize the model investigated in [30] in the case of interacting phantom and YM fields. This allows us to obtain some exact solutions for the accelerated expansion of FRW ...

  2. Computational hybrid anthropometric paediatric phantom library for internal radiation dosimetry

    NARCIS (Netherlands)

    Xie, Tianwu; Kuster, Niels; Zaidi, Habib

    2017-01-01

    Hybrid computational phantoms combine voxel-based and simplified equation-based modelling approaches to provide unique advantages and more realism for the construction of anthropomorphic models. In this work, a methodology and C++ code are developed to generate hybrid computational phantoms covering

  3. Building and assessing anatomically relevant phantoms for neonatal transcranial ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Memoli, G; Sadhoo, N; Gelat, P; Shaw, A [Acoustics and Ionising Radiation Division, National Physical Laboratory, Teddington (United Kingdom); Gatto, M; Harris, R A, E-mail: gianluca.memoli@npl.co.uk [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough (United Kingdom)

    2011-02-01

    This study describes the design and construction of a clinically relevant phantom to survey the temperature increase caused by ultrasound equipment, as currently used in neonatal head-scanning in the UK. The phantom is an ellipsoid of bone-mimic material, filled with brain-mimic; a circular hole in the external surface mimicks the fontanel, through which most clinically relevant scans are made. Finite-element simulations were used to identify possible hot spots and decide the most effective thermocouple positions within the phantom to investigate temperature rise during a typical scan. Novel materials were purposively designed to simulate key acoustic and thermal properties. Three Dimensional Printing (3DP) was employed for the fabrication of the skull phantom, and a specific strategy was successfully pursued to embed a thermocouple within the 3DP skull phantom during the manufacturing process. An in-process Non-Destructive Analysis (NDA) was used to assess the correct position of the deposited thermocouple inside the fabricated skull phantom. The temperature increase in the phantom for a typical trans-fontanellar scan is also presented here. The current phantom will be used in a hospital survey in the UK and, in its final design, will allow for a more reliable evaluation of ultrasound heating than is currently possible.

  4. Evaluation of DQA for tomography using 3D volumetric phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Uk [Dept. of Radiation Oncology, Catholic University of Incheon St. Mary' s Hospital, Incheon (Korea, Republic of); Kim, Jeong Koo [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of)

    2016-12-15

    The study investigates the necessity of 3 dimensional dose distribution evaluation instead of point dose and 2 dimensional dose distribution evaluation. Treatment plans were generated on the RANDO phantom to measure the precise dose distribution of the treatment site 0.5, 1, 1.5, 2, 2.5, 3 cm with the prescribed dose; 1,200 cGy, 5 fractions. Gamma analysis (3%/3 mm, 2%/2 mm) of dose distribution was evaluated with gafchromic EBT2 film and ArcCHECK phantom. The average error of absolute dose was measured at 0.76±0.59% and 1.37±0.76% in cheese phantom and ArcCHECK phantom respectively. The average passing ratio for 3%/3 mm were 97.72±0.02% and 99.26±0.01% in gafchromic EBT2 film and ArcCHECK phantom respectively. The average passing ratio for 2%/2 mm were 94.21±0.02% and 93.02±0.01% in gafchromic EBT2 film and ArcCHECK phantom respectively. There was a more accurate dose distribution of 3D volume phantom than cheese phantom in patients DQA using tomotherapy. Therefor it should be evaluated simultaneously 3 dimensional dose evaluation on target and peripheral area in rotational radiotherapy such as tomotherapy.

  5. Phantom limb phenomenon as an example of body image distortion

    Directory of Open Access Journals (Sweden)

    Razmus Magdalena

    2017-06-01

    Full Text Available Introduction: The perception of one’s own body, its mental representation, and emotional attitude to it are the components of so-called “body image” [1]. The aim of the research was to analyse phantom pain and non-painful phantom sensations as results of limb loss and to explain them in terms of body image distortion.

  6. Usefulness of milnacipran in treating phantom limb pain

    Directory of Open Access Journals (Sweden)

    Matsumoto Y

    2012-11-01

    Full Text Available Yasuhide Nagoshi,1 Akira Watanabe,1 Saiko Inoue,1 Tomoki Kuroda,2 Mitsuo Nakamura,3 Yoshitake Matsumoto,4 Kenji Fukui31Department of Psychiatry (Psychosomatic Medicine, Kyoto First Red Cross Hospital, Kyoto, Japan; 2Gojouyama Hospital, Nara, Japan; 3Department of Psychiatry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan; 4Matsumoto Clinic, Kyoto, JapanBackground: Amputation of an extremity often results in the sensation of a “phantom limb” where the patient feels that the limb that has been amputated is still present. This is frequently accompanied by “phantom limb pain”. We report here the use of milnacipran, a serotonin and norepinephrine reuptake inhibitor, to treat phantom limb pain after amputation of injured or diseased limbs in three patients.Methods and results: The severity of phantom pain before and during treatment was quantified using a visual analog scale. In one case, phantom limb pain responded partially to treatment with high doses of paroxetine, and then replacement with milnacipran further improved the pain relief and long-term full pain relief was achieved. In the two other cases, milnacipran was used as first-line treatment and phantom limb pain responded rapidly.Conclusion: These results suggest that milnacipran administration may be useful in phantom limb pain, possibly as a first-line treatment.Keywords: milnacipran, paroxetine, phantom limb pain, selective serotonin reuptake inhibitor (SSRI, serotonin and norepinephrine reuptake inhibitor (SNRI

  7. An MRI digital brain phantom for validation of segmentation methods.

    Science.gov (United States)

    Alfano, Bruno; Comerci, Marco; Larobina, Michele; Prinster, Anna; Hornak, Joseph P; Selvan, S Easter; Amato, Umberto; Quarantelli, Mario; Tedeschi, Gioacchino; Brunetti, Arturo; Salvatore, Marco

    2011-06-01

    Knowledge of the exact spatial distribution of brain tissues in images acquired by magnetic resonance imaging (MRI) is necessary to measure and compare the performance of segmentation algorithms. Currently available physical phantoms do not satisfy this requirement. State-of-the-art digital brain phantoms also fall short because they do not handle separately anatomical structures (e.g. basal ganglia) and provide relatively rough simulations of tissue fine structure and inhomogeneity. We present a software procedure for the construction of a realistic MRI digital brain phantom. The phantom consists of hydrogen nuclear magnetic resonance spin-lattice relaxation rate (R1), spin-spin relaxation rate (R2), and proton density (PD) values for a 24 × 19 × 15.5 cm volume of a "normal" head. The phantom includes 17 normal tissues, each characterized by both mean value and variations in R1, R2, and PD. In addition, an optional tissue class for multiple sclerosis (MS) lesions is simulated. The phantom was used to create realistic magnetic resonance (MR) images of the brain using simulated conventional spin-echo (CSE) and fast field-echo (FFE) sequences. Results of mono-parametric segmentation of simulations of sequences with different noise and slice thickness are presented as an example of possible applications of the phantom. The phantom data and simulated images are available online at http://lab.ibb.cnr.it/. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Phantom limb pain: a case of maladaptive CNS plasticity?

    DEFF Research Database (Denmark)

    Flor, Herta; Nikolajsen, Lone; Jensen, Troels Staehelin

    2006-01-01

    Phantom pain refers to pain in a body part that has been amputated or deafferented. It has often been viewed as a type of mental disorder or has been assumed to stem from pathological alterations in the region of the amputation stump. In the past decade, evidence has accumulated that phantom pain...

  9. Phantom jam avoidance through in-car speed advice

    NARCIS (Netherlands)

    Suijs, L.C.W.; Wismans, Luc Johannes Josephus; Krol, L.; van Berkum, Eric C.

    2015-01-01

    The existence of phantom jams can be explained following the definition of Kerner & Konhäuser (1993) who state that a phantom jam occurs without the existence of a physical bottleneck and is caused by the imperfect driving style of road users under metastable traffic conditions. In order to prevent

  10. THE EFFECT OF PHANTOM GROUPS ON GENETIC TREND

    African Journals Online (AJOL)

    Helena Theron

    North America was a combination between the United States of. America (USA) and Canada ... then be assigned to the following phantom parent group: North America x (1981-1985) x Sire-of-sire. Note ..... animals with phantom parent groups in the analysis, the genetic level of migrant animals is separated from that of base ...

  11. The impact of anthropometric patient-phantom matching on organ dose: A hybrid phantom study for fluoroscopy guided interventions

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Perry B.; Geyer, Amy; Borrego, David; Ficarrotta, Kayla; Johnson, Kevin; Bolch, Wesley E. [Nuclear and Radiological Engineering, University of Florida, Gainesville, Florida 32611 (United States); Radiology, University of Florida, Jacksonville, Florida 32209 (United States); Department of Nuclear and Radiological/Biomedical Engineering, University of Florida, Gainesville, Florida 32611-8300 (United States)

    2011-02-15

    Purpose: To investigate the benefits and limitations of patient-phantom matching for determining organ dose during fluoroscopy guided interventions. Methods: In this study, 27 CT datasets representing patients of different sizes and genders were contoured and converted into patient-specific computational models. Each model was matched, based on height and weight, to computational phantoms selected from the UF hybrid patient-dependent series. In order to investigate the influence of phantom type on patient organ dose, Monte Carlo methods were used to simulate two cardiac projections (PA/left lateral) and two abdominal projections (RAO/LPO). Organ dose conversion coefficients were then calculated for each patient-specific and patient-dependent phantom and also for a reference stylized and reference hybrid phantom. The coefficients were subsequently analyzed for any correlation between patient-specificity and the accuracy of the dose estimate. Accuracy was quantified by calculating an absolute percent difference using the patient-specific dose conversion coefficients as the reference. Results: Patient-phantom matching was shown most beneficial for estimating the dose to heavy patients. In these cases, the improvement over using a reference stylized phantom ranged from approximately 50% to 120% for abdominal projections and for a reference hybrid phantom from 20% to 60% for all projections. For lighter individuals, patient-phantom matching was clearly superior to using a reference stylized phantom, but not significantly better than using a reference hybrid phantom for certain fields and projections. Conclusions: The results indicate two sources of error when patients are matched with phantoms: Anatomical error, which is inherent due to differences in organ size and location, and error attributed to differences in the total soft tissue attenuation. For small patients, differences in soft tissue attenuation are minimal and are exceeded by inherent anatomical differences

  12. Spontaneous aortic thrombosis in a neonate with multiple thrombi in the main branches of the abdominal aorta.

    Science.gov (United States)

    Kawahira, Y; Kishimoto, H; Lio, M; Ikawa, S; Kume, Y; Inamura, N; Matushita, T; Maeno, T; Nakada, T

    1995-04-01

    Spontaneous aortic thrombosis in the neonate is a rare entity with a high mortality rate. The present patient, who was diagnosed after showing haematuria and cyanosis, underwent aortic thrombectomy with a Fogarty catheter through a left thoracotomy, but died of sepsis, disseminated intravascular coagulation and multiple organ failure. Autopsy revealed multiple residual thrombi in the main branches of the abdominal aorta and necrosis of the abdominal organs despite a patent thoracoabdominal aorta. In patients with no blood flow in the main branches of the abdominal aorta on preoperative examination, removal of thrombi, including those in the main branches of the abdominal aorta, might be performed in a single, early and aggressive procedure.

  13. Tratamiento endovascular de las patologías de aorta -Estado del arte-: Parte 1 - Aneurismas de aorta abdominal Endovascular treatment of aortic pathologies -State of the art-: Part 1 - Aneurysms of abdominal aorta

    Directory of Open Access Journals (Sweden)

    Carlos E Uribe

    2007-12-01

    Full Text Available En la actualidad, el tratamiento endovascular de las patologías de aorta es una alternativa a la cirugía abierta. Éste ha demostrado ser seguro ya que arroja resultados iguales o superiores que el grupo quirúrgico. En este artículo se presenta el estado actual del tratamiento con endoprótesis de las patologías de aorta, así como las indicaciones, las contraindicaciones y el futuro del tratamiento con este tipo de dispositivos.Endovascular treatment of aortic pathologies is actually an alternative to open surgery. It has proven to be safe, showing similar or better results to those achieved by surgery. In this article, treatment of aortic pathologies by means of endoprosthesis is presented, as well as its indications, contraindications and future treatment with this kind of devices.

  14. Validation of phantom-based harmonization for patient harmonization.

    Science.gov (United States)

    Panetta, Joseph V; Daube-Witherspoon, Margaret E; Karp, Joel S

    2017-07-01

    To improve the precision of multicenter clinical trials, several efforts are underway to determine scanner-specific parameters for harmonization using standardized phantom measurements. The goal of this study was to test the correspondence between quantification in phantom and patient images and validate the use of phantoms for harmonization of patient images. The National Electrical Manufacturers' Association image quality phantom with hot spheres was scanned on two time-of-flight PET scanners. Whole-body [18 F]-fluorodeoxyglucose (FDG)-PET scans were acquired of subjects on the same systems. List-mode events from spheres (diam.: 10-28 mm) measured in air on each scanner were embedded into the phantom and subject list-mode data from each scanner to create lesions with known uptake with respect to the local background in the phantom and each subject's liver and lung regions, as a proxy to characterize true lesion quantification. Images were analyzed using the contrast recovery coefficient (CRC) typically used in phantom studies and serving as a surrogate for the standardized uptake value used clinically. Postreconstruction filtering (resolution recovery and Gaussian smoothing) was applied to determine if the effect on the phantom images translates equivalently to subject images. Three postfiltering strategies were selected to harmonize the CRCmean or CRCmax values between the two scanners based on the phantom measurements and then applied to the subject images. Both the average CRCmean and CRCmax values for lesions embedded in the lung and liver in four subjects (BMI range 25-38) agreed to within 5% with the CRC values for lesions embedded in the phantom for all lesion sizes. In addition, the relative changes in CRCmean and CRCmax resulting from the application of the postfilters on the subject and phantom images were consistent within measurement uncertainty. Further, the root mean squared percent difference (RMSpd ) between CRC values on the two scanners

  15. Differences in the Thoracic Aorta by Region and Sex in a Murine Model of Marfan Syndrome.

    Science.gov (United States)

    Jiménez-Altayó, Francesc; Siegert, Anna-Maria; Bonorino, Fabio; Meirelles, Thayna; Barberà, Laura; Dantas, Ana P; Vila, Elisabet; Egea, Gustavo

    2017-01-01

    Marfan syndrome (MFS) is a hereditary disorder of the connective tissue that causes life-threatening aortic aneurysm, which initiates at the aortic root and can progress into the ascending portion. However, analysis of ascending aorta reactivity in animal models of MFS has remained elusive. Epidemiologic evidence suggests that although MFS is equally prevalent in men and women, men are at a higher risk of aortic complications than non-pregnant women. Nevertheless, there is no experimental evidence to support this hypothesis. The aim of this study was to explore whether there are regional and sex differences in the thoracic aorta function of mice heterozygous for the fibrillin 1 ( Fbn1 ) allele encoding a missense mutation ( Fbn1 C1039G/+ ), the most common class of mutation in MFS. Ascending and descending thoracic aorta reactivity was evaluated by wire myography. Ascending aorta mRNA and protein levels, and elastic fiber integrity were assessed by qRT-PCR, Western blotting, and Verhoeff-Van Gieson histological staining, respectively. MFS differently altered reactivity in the ascending and descending thoracic aorta by either increasing or decreasing phenylephrine contractions, respectively. When mice were separated by sex, contractions to phenylephrine increased progressively from 3 to 6 months of age in MFS ascending aortas of males, whereas contractions in females were unchanged. Endothelium-dependent relaxation was unaltered in the MFS ascending aorta of either sex; an effect related to augmented endothelium-dependent hyperpolarization-type dilations. In MFS males, the non-selective cyclooxygenase (COX) inhibitor indomethacin prevented the MFS-induced enhancement of phenylephrine contractions linked to increased COX-2 expression. In MFS mice of both sexes, the non-selective nitric oxide synthase inhibitor L-NAME revealed negative feedback of nitric oxide on phenylephrine contractions, which was associated with upregulation of eNOS in females. Finally, MFS

  16. Differences in the Thoracic Aorta by Region and Sex in a Murine Model of Marfan Syndrome

    Directory of Open Access Journals (Sweden)

    Francesc Jiménez-Altayó

    2017-11-01

    Full Text Available Marfan syndrome (MFS is a hereditary disorder of the connective tissue that causes life-threatening aortic aneurysm, which initiates at the aortic root and can progress into the ascending portion. However, analysis of ascending aorta reactivity in animal models of MFS has remained elusive. Epidemiologic evidence suggests that although MFS is equally prevalent in men and women, men are at a higher risk of aortic complications than non-pregnant women. Nevertheless, there is no experimental evidence to support this hypothesis. The aim of this study was to explore whether there are regional and sex differences in the thoracic aorta function of mice heterozygous for the fibrillin 1 (Fbn1 allele encoding a missense mutation (Fbn1C1039G/+, the most common class of mutation in MFS. Ascending and descending thoracic aorta reactivity was evaluated by wire myography. Ascending aorta mRNA and protein levels, and elastic fiber integrity were assessed by qRT-PCR, Western blotting, and Verhoeff-Van Gieson histological staining, respectively. MFS differently altered reactivity in the ascending and descending thoracic aorta by either increasing or decreasing phenylephrine contractions, respectively. When mice were separated by sex, contractions to phenylephrine increased progressively from 3 to 6 months of age in MFS ascending aortas of males, whereas contractions in females were unchanged. Endothelium-dependent relaxation was unaltered in the MFS ascending aorta of either sex; an effect related to augmented endothelium-dependent hyperpolarization-type dilations. In MFS males, the non-selective cyclooxygenase (COX inhibitor indomethacin prevented the MFS-induced enhancement of phenylephrine contractions linked to increased COX-2 expression. In MFS mice of both sexes, the non-selective nitric oxide synthase inhibitor L-NAME revealed negative feedback of nitric oxide on phenylephrine contractions, which was associated with upregulation of eNOS in females. Finally

  17. Cortical depression and potentiation: basic mechanisms for phantom pain.

    Science.gov (United States)

    Zhuo, Min

    2012-12-01

    People experience the feeling of the missing body part long after it has been removed after amputation are known as phantom limb sensations. These sensations can be painful, sometimes becoming chronic and lasting for several years (or called phantom pain). Medical treatment for these individuals is limited. Recent neurobiological investigations of brain plasticity after amputation have revealed new insights into the changes in the brain that may cause phantom limb sensations and phantom pain. In this article, I review recent progresses of the cortical plasticity in the anterior cingulate cortex (ACC), a critical cortical area for pain sensation, and explore how they are related to abnormal sensory sensations such as phantom pain. An understanding of these alterations may guide future research into medical treatment for these disorders.

  18. Tissue-like phantoms for quantitative birefringence imaging.

    Science.gov (United States)

    Liu, Xinyu; Beaudette, Kathy; Wang, Xianghong; Liu, Linbo; Bouma, Brett E; Villiger, Martin

    2017-10-01

    Birefringence imaging, including polarization sensitive optical coherence tomography (PS-OCT), can provide valuable insight into the microscopic structure and organization of many biological tissues. In this paper, we report on a method to fabricate tissue-like birefringence phantoms for such imaging modalities. We utilize the photo-elastic effect, wherein birefringence is induced by stretching a polymer sample after heating it above its glass-transition temperature. The cooled samples stably exhibit homogeneous birefringence, and were assembled into phantoms containing multiple well-defined regions of distinct birefringence. We present planar slab phantoms for microscopy applications and cylindrical phantoms for catheter-based imaging and demonstrate quantitative analysis of the birefringence within individual regions of interest. Birefringence phantoms enable testing, validating, calibrating, and improving PS-OCT acquisition systems and reconstruction strategies.

  19. Surgical phantom for off-pump mitral valve replacement

    Science.gov (United States)

    McLeod, A. Jonathan; Moore, John; Guiraudon, Gerard M.; Jones, Doug L.; Campbell, Gordon; Peters, Terry M.

    2011-03-01

    Off-pump, intracardiac, beating heart surgery has the potential to improve patient outcomes by eliminating the need for cardiopulmonary bypass and aortic cross clamping but it requires extensive image guidance as well as the development of specialized instrumentation. Previously, developments in image guidance and instrumentation were validated on either a static phantom or in vivo through porcine models. This paper describes the design and development of a surgical phantom for simulating off-pump mitral valve replacement inside the closed beating heart. The phantom allows surgical access to the mitral annulus while mimicking the pressure inside the beating heart. An image guidance system using tracked ultrasound, magnetic instrument tracking and preoperative models previously developed for off-pump mitral valve replacement is applied to the phantom. Pressure measurements and ultrasound images confirm the phantom closely mimics conditions inside the beating heart.

  20. Tensile characterisation of the aorta across quasi-static to blast loading strain rates

    Science.gov (United States)

    Magnus, Danyal; Proud, William; Haller, Antoine; Jouffroy, Apolline

    2017-06-01

    The dynamic tensile failure mechanisms of the aorta during Traumatic Aortic Injury (TAI) are poorly understood. In automotive incidents, where the aorta may be under strains of the order of 100/s, TAI is the second largest cause of mortality. In these studies, the proximal descending aorta is the most common site where rupture is observed. In particular, the transverse direction is most commonly affected due to the circumferential orientation of elastin, and hence the literature generally concentrates upon axial samples. This project extends these dynamic studies to the blast loading regime where strain-rates are of the order of 1000/s. A campaign of uniaxial tensile experiments are conducted at quasi-static, intermediate (drop-weight) and high (tensile Split-Hopkinson Pressure Bar) strain rates. In each case, murine and porcine aorta models are considered and the extent of damage assessed post-loading using histology. Experimental data will be compared against current viscoelastic models of the aorta under axial stress. Their applicability across strain rates will be discussed. Using a multi-disciplinary approach, the conditions applied to the samples replicate in vivo conditions, employing a blood simulant-filled tubular specimen surrounded by a physiological solution.

  1. Reduced expression of perlecan in the aorta of secondary hyperparathyroidism model rats with medial calcification.

    Science.gov (United States)

    Shibata, Maki; Shigematsu, Takashi; Hatamura, Ikuji; Saji, Fumie; Mune, Sachiko; Kunimoto, Ken; Hanba, Yoshiyuki; Shiizaki, Kazuhiro; Sakaguchi, Toshifumi; Negi, Shigeo

    2010-01-01

    Vascular calcification is an important complication that worsens the prognosis for dialysis patients, although its detailed molecular mechanisms are still unknown. We produced a rat model for vascular calcification with hyperphosphatasemia and hyperparathyroidism, performing a 5/6 nephrectomy and providing a high-phosphorus, low-calcium diet for eight weeks. We examined mRNA obtained from the calcified aortae using microarray analysis, and searched for alterations in gene expression specifically in the calcified lesions. Medial calcification was demonstrated in the abdominal aorta of 12 out of 42 hyperparathyroidism rats. In the aortae of hyperparathyroid rats with vascular calcification, the genes for heparan sulfate proteoglycans, including perlecan, were found to be down-regulated using microarray analysis and real time PCR. Immunohistochemistry also demonstrated reduced production of perlecan in the aortae of hyperparathyroid rats. Perlecan is a major component of the vascular wall basement membrane and may play a role in protecting vascular smooth muscle cells from inflammatory cells and various toxins. It has also been reported that heparan sulfate chains may inhibit osteogenesis. Our findings indicate that perlecan may protect vascular smooth muscle cells from various factors that promote vascular calcification. It may be that reduced expression of perlecan in the calcified aortae of hyperparathyroid rats is a risk factor for vascular calcification.

  2. Safe wrapping of the borderline dilated ascending aorta during aortic valve replacement.

    Science.gov (United States)

    Tappainer, Ernesto; Fiorani, Vinicio; Nocchi, Andrea; Likaj, Ermal; Memishaj, Sabjan; Zogno, Mario

    2007-02-22

    Techniques of reduction aortoplasty are widely published in the literature with conflicting results. External support seems to be an important factor in preventing recurrence but, in some cases, this technique caused erosion of the aorta because of the wrinkles the prosthesis creates in the rear side of the aorta. A 73 year old patient with aortic valve stenosis and borderline dilated ascending aorta had aortic valve replacement and simple wrapping without aortoplasty. To avoid the formation of wrinkles, the dacron external support was tailored appropriately to obtain a curved, custom-made prosthesis. This custom-made prosthesis had the same diameter as the dilated aorta and, after valve replacement, fitted it properly. After 18 months neither computerized axial tomography nor ecocardiography detected wrinkles or dilatation recurrence. A safe, simple and probably new way to prepare an external wrapping is presented, which in this patient respected the shape of the aorta and prevented the formation of wrinkles in the prosthesis and possible complications such as wall erosion.

  3. Safe wrapping of the borderline dilated ascending aorta during aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Tappainer Ernesto

    2007-02-01

    Full Text Available Abstract Background Techniques of reduction aortoplasty are widely published in the literature with conflicting results. External support seems to be an important factor in preventing recurrence but, in some cases, this technique caused erosion of the aorta because of the wrinkles the prosthesis creates in the rear side of the aorta. Case presentation A 73 year old patient with aortic valve stenosis and borderline dilated ascending aorta had aortic valve replacement and simple wrapping without aortoplasty. To avoid the formation of wrinkles, the dacron external support was tailored appropriately to obtain a curved, custom-made prosthesis. This custom-made prosthesis had the same diameter as the dilated aorta and, after valve replacement, fitted it properly. After 18 months neither computerized axial tomography nor ecocardiography detected wrinkles or dilatation recurrence. Conclusion A safe, simple and probably new way to prepare an external wrapping is presented, which in this patient respected the shape of the aorta and prevented the formation of wrinkles in the prosthesis and possible complications such as wall erosion.

  4. Anestesia en la coartación de la aorta

    Directory of Open Access Journals (Sweden)

    Lincoln de la Parte Pérez

    2001-12-01

    Full Text Available Se presenta un estudio retrospectivo de 200 pacientes operados de coartación de la aorta, en el Cardiocentro del Hospital Pediátrico Universitario "William Soler", en el período de 1990 a 1995. La ketamina fue el agente más utilizado en la premedicación anestésica de nuestros pacientes (190 pacientes, 95 %. En 150 pacientes se utilizó asociada con la atropina y en 40 se le adicionó además midazolam. En los 10 enfermos restantes se empleó sólo atropina. El fentanyl fue el agente más utilizado en la inducción de la anestesia (123 pacientes, 61,5 % y en el mantenimiento (186 enfermos, 92 % y aportó gran estabilidad hemodinámica. Se empleó vasodilatador en la mayoría de los pacientes (176 pacientes, 88 %, para el control de la presión arterial y dentro de éstos, los más utilizados fueron la nitroglicerina mezclada con regitina en 135 pacientes (67,5 %. Las complicaciones más frecuentes fueron la hipertensión arterial (76 pacientes, 38 % la acidosis metabólica (24 pacientes, 12 % y las arritmias cardíacas (14 pacientes, 7 %.A retrospective study of 200 patients operated on of aortic coarctation at the Cardiology Center of "William Soler" Pediatric Teaching Hospital from 1990 to 1995 was conducted. Ketamine was the most used agent in the anesthetic premedication of our patients (190 patients, 95 %. It was associated with atropine in 150 patients and midazolan was also added in 40 patients. In the other 10 patients atropine was only used. Fentanyl was the most administered agent in the induction of anesthesia (123 patients, 61.5 % and in the maintenance (186 patients, 92 %. It provided a great hemodynamic stability. Vasodilators were used in most of the patients (176 patients, 88 % to control arterial pressure. The most used were nitroglycerin mixed with regitine (135 patients, 67.5 %. The most frequent complications were arterial hypertension (76 patients, 38 %, metabolic acidosis (24 patients, 12 %, and cardiac arrhytmias (14

  5. Enfermedad ectasiante de la aorta abdominal: Morbilidad y mortalidad

    Directory of Open Access Journals (Sweden)

    Lilia E Chércoles Cazate

    1996-06-01

    Full Text Available Se presentó la experiencia de 10 años de trabajo (1983 a 1992, durante los cuales se atendieron 388 pacientes en el Hospital Provincial Docente "Saturnino Lora" de Santiago de Cuba, con el diagnóstico principal o asociado de aneurisma de la aorta abdominal. En el período analizado ingresaron en angiología y cirugía vascular 98 pacientes, 176 en medicina y 8 en otros servicios. Fallecieron a su llegada al cuerpo de guardia 106 por rotura del aneurisma o disección aórtica. Predominó el sexo masculino y la procedencia urbana. La hipertensión arterial fue la afección asociada más frecuente en los operados y la cardiopatía isquémica en los no operados. En los operados electivos, la complicación inmediata que más ocurrencia tuvo fue la trombosis de una rama de la prótesis y en los urgentes el sangramiento; mientras que en las mediatas, los operados electivos presentaron bronconeumonía y en los urgentes, anemia e íleo paralíticoThe experience of ten years of work (1983-1992 was presented. During that period, 388 patients with the main of associated diagnosis of abdominal aortic aneurysm were managed at the "Saturnino Lora" Provincial Educational Hospital, at Santiago de Cuba. In the decade analyzed, 98 patients entered in angiology and vascular surgery, 176 patients entered in medicine, and 8 in other services. In arriving to the emergency room, 106 subjects deceased due to aneurystic rupture or aortic dissection. Masculine sex and urban origin were prevailing. Arterial hypertension was the disease most frequently associated in the operated patients, and ischemic cardiac disease, among the non operated. In the elective operated patients, the immediate complication with the highest occurrence was the thrombosis of a branch of the prosthesis, and bleeding in the urgent cases, while in the mediate complications, the elective operated patients presented bronchopneumonia, and the urgent cases had anemia and paralytic ileus

  6. CD45{sup low}c-Kit{sup high} cells have hematopoietic properties in the mouse aorta-gonad-mesonephros region

    Energy Technology Data Exchange (ETDEWEB)

    Nobuhisa, Ikuo, E-mail: nobuhisa.scr@mri.tmd.ac.jp [Department of Stem Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan); Department of Cell Fate Modulation, Institute of Molecular Embryology and Genetics/Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, 860-0811 (Japan); Yamasaki, Shoutarou [Department of Cell Fate Modulation, Institute of Molecular Embryology and Genetics/Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, 860-0811 (Japan); Ramadan, Ahmed [Department of Stem Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan); Department of Cell Fate Modulation, Institute of Molecular Embryology and Genetics/Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, 860-0811 (Japan); Taga, Tetsuya, E-mail: taga.scr@mri.tmd.ac.jp [Department of Stem Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan); Department of Cell Fate Modulation, Institute of Molecular Embryology and Genetics/Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, 860-0811 (Japan)

    2012-04-01

    Long-term reconstituting hematopoietic stem cells first arise from the aorta of the aorta-gonad-mesonephros (AGM) region in a mouse embryo. We have previously reported that in cultures of the dispersed AGM region, CD45{sup low}c-Kit{sup +} cells possess the ability to reconstitute multilineage hematopoietic cells, but investigations are needed to show that this is not a cultured artifact and to clarify when and how this population is present. Based on the expression profile of CD45 and c-Kit in freshly dissociated AGM cells from embryonic day 9.5 (E9.5) to E12.5 and aorta cells in the AGM from E13.5 to E15.5, we defined six cell populations (CD45{sup -}c-Kit{sup -}, CD45{sup -}c-Kit{sup low}, CD45{sup -}c-Kit{sup high}, CD45{sup low}c-Kit{sup high}, CD45{sup high}c-Kit{sup high}, and CD45{sup high}c-Kit{sup very} {sup low}). Among these six populations, CD45{sup low}c-Kit{sup high} cells were most able to form hematopoietic cell colonies, but their ability decreased after E11.5 and was undetectable at E13.5 and later. The CD45{sup low}c-Kit{sup high} cells showed multipotency in vitro. We demonstrated further enrichment of hematopoietic activity in the Hoechst dye-effluxing side population among the CD45{sup low}c-Kit{sup high} cells. Here, we determined that CD45{sup low}c-Kit{sup high} cells arise from the lateral plate mesoderm using embryonic stem cell-derived differentiation system. In conclusion, CD45{sup low}c-Kit{sup high} cells are the major hematopoietic cells of mouse AGM.

  7. Phantom space-times in fake supergravity

    Science.gov (United States)

    Bu Taam, Maryam; Sabra, Wafic A.

    2015-12-01

    We discuss phantom metrics admitting Killing spinors in fake N = 2, D = 4 supergravity coupled to vector multiplets. The Abelian U (1) gauge fields in the fake theory have kinetic terms with the wrong sign. We solve the Killing spinor equations for the standard and fake theories in a unified fashion by introducing a parameter which distinguishes between the two theories. The solutions found are fully determined in terms of algebraic conditions, the so-called stabilisation equations, in which the symplectic sections are related to a set of functions. These functions are harmonic in the case of the standard supergravity theory and satisfy the wave-equation in flat (2 + 1)-space-time in the fake theory. Explicit examples are given for the minimal models with quadratic prepotentials.

  8. Phantom space–times in fake supergravity

    Directory of Open Access Journals (Sweden)

    Maryam Bu Taam

    2015-12-01

    Full Text Available We discuss phantom metrics admitting Killing spinors in fake N=2, D=4 supergravity coupled to vector multiplets. The Abelian U(1 gauge fields in the fake theory have kinetic terms with the wrong sign. We solve the Killing spinor equations for the standard and fake theories in a unified fashion by introducing a parameter which distinguishes between the two theories. The solutions found are fully determined in terms of algebraic conditions, the so-called stabilisation equations, in which the symplectic sections are related to a set of functions. These functions are harmonic in the case of the standard supergravity theory and satisfy the wave-equation in flat (2+1-space–time in the fake theory. Explicit examples are given for the minimal models with quadratic prepotentials.

  9. Phantom limb pain: a nursing perspective.

    Science.gov (United States)

    Virani, Anila; Green, Theresa; Turin, Tanvir C

    2014-09-09

    Phantom limb pain (PLP) is a neuropathic pain condition occurring after amputation of a limb. PLP affects amputees' quality of life and results in loss of productivity and psychological distress. The origin of pain from a non-existing limb creates a challenging situation for both patients and nurses. It is imperative to provide patients and nurses with the knowledge that PLP is a real phenomenon that requires care and treatment. This knowledge will lead to reduced problems for patients by allowing them to talk about PLP and ask for help when needed. Understanding of this phenomenon will enable nurses to appreciate the unique features of this form of neuropathic pain and apply appropriate techniques to promote effective pain management. Performing accurate and frequent assessments to understand the unique characteristics of PLP, displaying a non-judgemental attitude towards patients and teaching throughout the peri-operative process are significant nursing interventions.

  10. Validation study of the thorax phantom Lungman for optimization purposes

    Science.gov (United States)

    Rodríguez Pérez, Sunay; Marshall, Nicholas W.; Struelens, Lara; Bosmans, Hilde

    2017-03-01

    This work aims to investigate the advantages and limitations of the Kyoto Kagaku thorax phantom Lungman for use in chest radiography optimization studies. First, patient survey data were gathered for chest posterior anterior (PA) and lateral (LAT) examinations in a standard chest X-ray room over a period of one year, using a Caesium Iodide (CsI) based flat panel detector with automatic exposure control (AEC). Parameters surveyed included exposure index (EI), dose area product (DAP) and AEC exposure time. PA and LAT projections of the phantom were then compared to these values. Additionally, the equivalence in millimetres of poly (methyl methacrylate) (PMMA) was established for the different regions of the Lungman phantom (lungs and mediastinum). Finally, a voxel model of the Lungman phantom was developed by the segmentation of a volumetric dataset of the phantom acquired using CT scanning. Subsequently, the model was used in Monte Carlo simulations with PENELOPE/penEasy code to calculate the energy deposited in the organs of the phantom. This enabled comparison of the phantom tissue-equivalent materials with materials defined by ICRP 89 in terms of energy deposition. For the survey data, close agreement was found between phantom and the median values for the patient data (deviations ranged from 4% to 31%, one outlier). The phantom lung region is equivalent to 89 mm to 106 mm of PMMA, depending on tube voltage. Energy deposited in the phantom material compared to those for ICRP defined material differed by at most 36% in AP irradiations and 49% in PA irradiations.

  11. Phantom breast sensations and phantom breast pain : A 2-year prospective study and a methodological analysis of literature

    NARCIS (Netherlands)

    Dijkstra, P.U.; Rietman, J.S.; Geertzen, J.H.B.

    The first aim of this study was to assess prospectively the incidence of phantom breast sensations (PB sensations) and phantom breast pain (PB pain) in a sample of patients treated for breast cancer (n = 204) by means of a modified radical mastectomy (n = 82). Patients were assessed 6 weeks, 6, 12

  12. Phantom breast sensations and phantom breast pain: A 2-year prospective study and a methodological analysis of literature

    NARCIS (Netherlands)

    Dijkstra, P.U.; Rietman, Johan Swanik; Geertzen, J.H.B.

    The first aim of this study was to assess prospectively the incidence of phantom breast sensations (PB sensations) and phantom breast pain (PB pain) in a sample of patients treated for breast cancer (n = 204) by means of a modified radical mastectomy (n = 82). Patients were assessed 6 weeks, 6, 12

  13. Quantitative magnetic resonance imaging phantoms: A review and the need for a system phantom.

    Science.gov (United States)

    Keenan, Kathryn E; Ainslie, Maureen; Barker, Alex J; Boss, Michael A; Cecil, Kim M; Charles, Cecil; Chenevert, Thomas L; Clarke, Larry; Evelhoch, Jeffrey L; Finn, Paul; Gembris, Daniel; Gunter, Jeffrey L; Hill, Derek L G; Jack, Clifford R; Jackson, Edward F; Liu, Guoying; Russek, Stephen E; Sharma, Samir D; Steckner, Michael; Stupic, Karl F; Trzasko, Joshua D; Yuan, Chun; Zheng, Jie

    2018-01-01

    The MRI community is using quantitative mapping techniques to complement qualitative imaging. For quantitative imaging to reach its full potential, it is necessary to analyze measurements across systems and longitudinally. Clinical use of quantitative imaging can be facilitated through adoption and use of a standard system phantom, a calibration/standard reference object, to assess the performance of an MRI machine. The International Society of Magnetic Resonance in Medicine AdHoc Committee on Standards for Quantitative Magnetic Resonance was established in February 2007 to facilitate the expansion of MRI as a mainstream modality for multi-institutional measurements, including, among other things, multicenter trials. The goal of the Standards for Quantitative Magnetic Resonance committee was to provide a framework to ensure that quantitative measures derived from MR data are comparable over time, between subjects, between sites, and between vendors. This paper, written by members of the Standards for Quantitative Magnetic Resonance committee, reviews standardization attempts and then details the need, requirements, and implementation plan for a standard system phantom for quantitative MRI. In addition, application-specific phantoms and implementation of quantitative MRI are reviewed. Magn Reson Med 79:48-61, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  14. Thrombosis of abdominal aorta during cisplatin-based chemotherapy of testicular seminoma - a case report

    Directory of Open Access Journals (Sweden)

    Gehrckens Ralf

    2009-12-01

    Full Text Available Abstract Background Vascular complications occurring during cisplatin-based chemotherapy of germ cell tumours are inadequately recognized to date. Case Presentation A 49 year old man with advanced seminoma underwent two courses of chemotherapy according to the PEB regimen. Upon restaging, two thrombotic deposits were noted in the descending part of the thoracic aorta and in the infrarenal abdominal aorta, respectively. Although thrombotic plaques caused aortic occlusion of about 30%, no clinical signs of malperfusion of limbs were registered. The patient was placed on anticoagulant therapy. Six months after completion of chemotherapy, thrombotic deposits had completely resolved. In the absence of other predisposing factors, it must be assumed that cisplatin-based chemotherapy represented a strong stimulus for arterial thrombosis in the aorta. Conclusions This is the first case of endo-aortic thrombosis during chemotherapy for testicular germ cell cancer. Providers of chemotherapy must be aware of arterial thrombosis even in young patients with testicular cancer.

  15. Thoracic and abdominal aortas stiffen through unique extracellular matrix changes in intrauterine growth restricted fetal sheep.

    Science.gov (United States)

    Dodson, R Blair; Rozance, Paul J; Petrash, Carson C; Hunter, Kendall S; Ferguson, Virginia L

    2014-02-01

    Intrauterine growth restriction (IUGR) is a fetal complication of pregnancy epidemiologically linked to cardiovascular disease in the newborn later in life. However, the mechanism is poorly understood with very little research on the vascular structure and function during development in healthy and IUGR neonates. Previously, we found vascular remodeling and increased stiffness in the carotid and umbilical arteries, but here we examine the remodeling and biomechanics in the larger vessels more proximal to the heart. To study this question, thoracic and abdominal aortas were collected from a sheep model of placental insufficiency IUGR (PI-IUGR) due to exposure to elevated ambient temperatures. Aortas from control (n = 12) and PI-IUGR fetuses (n = 10) were analyzed for functional biomechanics and structural remodeling. PI-IUGR aortas had a significant increase in stiffness (P IUGR may set the stage for possible altered growth and development and help to explain the pathophysiology of adult cardiovascular disease in previously IUGR individuals.

  16. THE ROLE OF THE HEREDITARY PREDISPOSITION IN THE DEVELOPMENT OF AORTA COARCTATION

    Directory of Open Access Journals (Sweden)

    T. N. Tatarinova

    2012-01-01

    Full Text Available As a result of examination of the families of patients with aorta coarctation the factors predisposing to this condition were established. Sixty eight patients with different localization, stenosis degree and extent of aorta coarctation were included into this study. All the patients were performed echocardiography, indirect and direct. Typical coarctation was found in 95,6% of the cases, in 55,9% it was associated with bicuspid aortic valve. The most significant predisposing factors to this anomaly development were compromised hereditary (33,8% and complications during pregnancy (57,4%. According to the received data, during the family planning it is important to examine both parents, as father’s disorders may have more marked impact on aorta coarctation development, than mother’s ones. Children with compromised heredity on congenital heart defects are recommended to be carried out echocardiographic investigation at the early period of time after birth, despite the absence of disorders on intrauterine ultrasound.

  17. Coartación de la aorta: una revisión sistemática

    OpenAIRE

    O Ruíz Pérez; LR Méndez Duran

    2015-01-01

    La coartación de la aorta es una patología caracterizada por el estrechamiento de la arteria aorta, con la consecuente obstrucción de su flujo; localizada con mayor frecuencia a nivel de aorta torácica descendente distal al origen de la subclavia izquierda, y en la pared posterior de la arteria. Supone aproximadamente el 5,1% (3-10%) de las cardiopatías congénitas y constituye la octava malformación cardiaca por orden de frecuencia. La presentación clínica de la coartación aórtica es muy vari...

  18. Percutaneous Closure of an Iatrogenic Aorta to Right Ventricle Fistula Acquired Following Intracardiac Repair.

    Science.gov (United States)

    Rajasekhar, Durgaprasad; Vanajakshamma, Velam; Ranganayakulu, Kummaraganti Paramathma

    2016-05-01

    Iatrogenic aortocardiac fistulae have been described rarely following intracardiac repair. This 28 year-old-male presented to our facility with dyspnea going on 20 days after closure of ventricular septal defect (VSD) and resection of subaortic membrane. A communication was noticed between the aorta and the right ventricle (RV) upon transthoracic echocardiography. Cardiac catheterisation revealed a significant shunt and an aortogram revealed a 6 mm communication between aorta and right ventricle. Percutaneous closure of this defect was attempted under local anaesthesia through right femoral access. An alpha arteriovenous loop was formed despite repeated attempts, hence a retrograde approach for device delivery was considered. An 8 mm Amplatzer muscular VSD occluder device was deployed across the defect achieving a complete closure through an 8F delivery sheath. To the best of our knowledge this is the first report of an iatrogenic aorta to RV fistula occurring in a patient following an intracardiac repair which has been successfully treated percutaneously.

  19. Beat Pressure and Comparing it with Ascending Aorta Pressure in Normal and Abnormal Conditions

    CERN Document Server

    Ghasemalizadeh, Omid; Firoozabadi, Bahar; Sajadi, Behrang; Zolfonoon, Ali

    2014-01-01

    Lumped method (Electrical analogy) is a quick and easy way to model human cardiovascular system. In this paper Lumped method is used for simulating a complete model. It describes a 36-vessel model and cardiac system of human body with details that could show hydrodynamic parameters of cardiovascular system. Also this paper includes modeling of pulmonary, atrium, left and right ventricles with their equivalent circuits. Exact modeling of right and left ventricles pressure with division of ascending aorta into 27 segments increases the accuracy of our simulation. In this paper we show that a calculated pressure for aorta from our complex circuit is near to measured pressure by using advanced medical instruments. Also it is shown that pressure graph from brachial is so near to aortic pressure because of this its pressure signal is usable instead of aortic pressure. Furthermore, obstruction in ascending aorta, brachial and its effects has been showed in different figures.

  20. Ovariectomy increases the participation of hyperpolarizing mechanisms in the relaxation of rat aorta.

    Directory of Open Access Journals (Sweden)

    Ana Sagredo

    Full Text Available This study examines the downstream NO release pathway and the contribution of different vasodilator mediators in the acetylcholine-induced response in rat aorta 5-months after the loss of ovarian function. Aortic segments from ovariectomized and control female Sprague-Dawley rats were used to measure: the levels of superoxide anion, the superoxide dismutases (SODs activity, the cGMP formation, the cGMP-dependent protein kinase (PKG activity and the involvement of NO, cGMP, hydrogen peroxide and hyperpolarizing mechanisms in the ACh-induced relaxation. The results showed that ovariectomy did not alter ACh-induced relaxation; incubation with L-NAME, a NO synthase inhibitor, decreased the ACh-induced response to a lesser extent in aorta from ovariectomized than from control rats, while ODQ, a guanylate cyclase inhibitor, decreased that response to a similar extent; the blockade of hyperpolarizing mechanisms, by precontracting arteries with KCl, decreased the ACh-induced response to a greater extent in aortas from ovariectomized than those from control rats; catalase, that decomposes hydrogen peroxide, decreased the ACh-induced response only in aorta from ovariectomized rats. In addition, ovariectomy increased superoxide anion levels and SODs activity, decreased cGMP formation and increased PKG activity. Despite the increased superoxide anion and decreased cGMP in aorta from ovariectomized rats, ACh-induced relaxation is maintained by the existence of hyperpolarizing mechanisms in which hydrogen peroxide participates. The greater contribution of hydrogen peroxide in ACh-induced relaxation is due to increased SOD activity, in an attempt to compensate for increased superoxide anion formation. Increased PKG activity could represent a redundant mechanism to ensure vasodilator function in the aorta of ovariectomized rats.

  1. Hubungan Phantom Vibration Syndrome Terhadap Sleep Disorder dan Kondisi Stress

    Directory of Open Access Journals (Sweden)

    Ajeng Yeni Setianingrum

    2017-10-01

    Full Text Available Phantom vibration syndrome is a condition where a person would feel the sensation of vibration of a cell phone as if there were incoming notification but the fact is not. This research investigated the relationship between phantom vibration syndromes, sleep disorder and stress condition. Questionnaires were distributed to 120 participants with age range 18 to 23 years old. Data of participants showed that all of participants using a smart mobile phone and 24% of them have more than one cell phone. Time usage of cell phone is at least 1 hour. 23% of participants using a cell phone for social media activity, followed by 21% related to entertainment (music, video and games. The results showed a positive relationship between phantom vibration syndrome, sleep disorder and stress condition. Insomnia contributed a greater influence on stress condition. However, the phantom vibration syndrome is more directly affecting the sleep apnea compared to insomnia and stress condition. Therefore, the phantom vibration syndrome more affects stress condition indirectly, through sleep disorder (sleep apnea and insomnia. Consequently, phantom vibration syndrome has a strong relationship with stress condition at the time of the phantom vibration syndrome can cause sleep disorder.

  2. Studies on Phantom Vibration and Ringing Syndrome among Postgraduate Students

    Directory of Open Access Journals (Sweden)

    Atul Kumar Goyal

    2015-03-01

    Full Text Available Phantom vibrations and ringing of mobile phones are prevalent hallucinations in the general population. They might be considered as a normal brain mechanism. The aim of this study was to establish the prevalence of Phantom vibrations and ringing syndrome among students and to assess factors associated it. The survey of 300 postgraduate students belonging to different field of specialization was conducted at Kurukshetra University. 74% of students were found to have both Phantom vibrations and ringing syndrome. Whereas 17% of students felt Phantom vibration exclusively and 4% students face only Phantom ringing syndrome. Both the syndrome occurs more fervent in students who kept their mobile phone in shirt or jean pocket than to who kept mobile in handbag. 75% of students felt vibration or ringing even when the phone is switched off or phone was not in their pocket. Also the frequency of both the syndrome is directly proportional to the duration of mobile phone use and person emotional behavior. Although most of students agree that the Phantom syndrome did not bother them but some students deals with anxiety when they feel symptoms associated with Phantom syndrome. By using mobile phones in proper way, one can avoid these syndromes, or at least can ameliorate the symptoms.

  3. Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging.

    Science.gov (United States)

    Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J; Ramella-Roman, Jessica C; Mathews, Scott A; Coburn, James C; Sorg, Brian S; Chen, Yu; Pfefer, T Joshua

    2015-01-01

    The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements—including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth—were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light–tissue interactions and characterizing biophotonic system performance.

  4. Individual differences in response to phantom limb movement therapy.

    Science.gov (United States)

    McAvinue, Laura P; Robertson, Ian H

    2011-01-01

    Phantom limb pain (PLP) is a distressing condition experienced by many amputees. The purpose of this study was to investigate whether motor imagery could be used to treat PLP. Four single case studies were conducted. The participants kept a pain diary in which they recorded the intensity of their PLP during a baseline period, general motor imagery training, phantom limb movement therapy and a follow-up period. Qualitative and quantitative (i.e. interrupted time series) analyses were employed to determine whether phantom limb movement therapy had a significant effect on PLP intensity. Phantom limb movement therapy significantly reduced intensity of PLP in one participant. One participant gained occasional relief by doing phantom limb movement therapy exercises but did not experience an overall reduction in PLP intensity. The third participant did not experience any relief and the fourth participant reported experiencing the re-emergence of an old pain. The results display individual differences in response to phantom limb movement therapy. Individual differences are discussed in the context of motor imagery ability and the phantom limb phenomenon as a multi-dimensional disorder.

  5. Neuroprotective effects of diltiazem in rabbits with occluded aorta Efeitos neuroprotetores do diltiazem em coelhos com oclusão da aorta

    Directory of Open Access Journals (Sweden)

    Tonguc Saba

    2007-12-01

    Full Text Available OBJECTIVE: In the present study, we aimed to determine the protective effect of the perfusion of the distal aorta with diltiazem and ringer lactate solution on the spinal cord. METHODS: Twenty-seven New Zealand rabbits were used in which spinal cord ischemia was provided by occlusion of the aorta for thirty minutes. Experimental animals were divided into four groups: group A (n=4, the sham operation group; group B (n=8 in which intraaortic balloon occlusion alone was applied; group C (n=7, ringer lactate group in which ringer lactate was perfused into distal aorta at a rate of 40 ml/kg, hr, following intraaortic balloon occlusion; group D (n=8 diltiazem group in which diltiazem 40 mg/kg, hr, in Ringer lactate was perfused into distal aorta following intraaortic balloon occlusion. Motor function of hind limbs was evaluated by Tarlov's scoring system. After observation, spinal cords were removed for histopathological evaluation. RESULTS: The degree of histopathological injury was well correlated with neurological function. The most severe histopathological injury and neurological dysfunction occurred in group B, followed by group C, D and A respectively. No injury or neurological dysfunction occurred in the sham group. CONCLUSIONS: The protective effect of diltiazem on both histopathological injury and neurological function was significant in comparison with control groups.OBJETIVO: O objetivo do presente trabalho é determinar o efeito protetor da perfusão na aorta distal com diltiazem e solução de Ringer lactato na medula espinal. MÉTODOS: Foram usados 27 coelhos da raça New-Zeland, nos quais se provocou isquemia da medula espinal por meio de oclusão da aorta durante 30 minutos. Os animais experimentais foram divididos em quatro grupos: grupo A (n=4, o grupo de cirurgia simulada (pseudocirurgia; o grupo B (n=8 no qual se aplicou somente a oclusão do balão intraaórtico; grupo C (n=7, o grupo do Ringer lactato, no qual a solução de

  6. Pharmacologic interventions for treating phantom limb pain.

    Science.gov (United States)

    Alviar, Maria Jenelyn M; Hale, Tom; Dungca, Monalisa

    2016-10-14

    This is an updated version of the original Cochrane review published in Issue 12, 2011. Phantom limb pain (PLP) is pain that arises in the missing limb after amputation and can be severe, intractable, and disabling. Various medications have been studied in the treatment of phantom pain. There is currently uncertainty in the optimal pharmacologic management of PLP. This review aimed to summarise the evidence of effectiveness of pharmacologic interventions in treating PLP. For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library), MEDLINE, and Embase for relevant studies. We ran the searches for the original review in September 2011 and subsequent searches for this update up to April 2016. We sought additional studies from clinical trials databases and reference lists of retrieved papers. We included randomised and quasi-randomised trials studying the effectiveness of pharmacologic interventions compared with placebo, another active treatment, or no treatment, in established PLP. We considered the following outcomes: change in pain intensity, function, sleep, depression or mood, quality of life, adverse events, treatment satisfaction, and withdrawals from the study. We independently assessed issues of study quality and extracted efficacy and adverse event data. Due to the wide variability in the studies, we did not perform a meta-analysis for all the interventions and outcomes, but attempted to pool the results of some studies where possible. We prepared a qualitative description and narrative summary of results. We assessed clinical heterogeneity by making qualitative comparisons of the populations, interventions, outcomes/outcome measures, and methods. We added only one new study with 14 participants to this updated review. We included a 14 studies (10 with low risk of bias and 4 with unclear risk of bias overall) with a total of 269 participants. We added another drug class, botulinum neurotoxins (BoNTs), in

  7. Endovascular Repair of Descending Thoracic Aorta in Loeys-Dietz II Syndrome.

    Science.gov (United States)

    Kalra, Ankur; Harris, Kevin M; Kische, Stephan; Alden, Peter; Schumacher, Clark; Nienaber, Christoph A

    2015-10-01

    Loeys-Dietz syndrome (LDS) is an autosomal dominant disorder that is predominantly characterized by involvement of the aorta, manifesting as aneurysmal dilatation or aortic dissection. Patients with LDS manifest with spontaneous aneurysms and dissections of central and peripheral arterial beds. We present 2 cases of young male patients with Loeys-Dietz II aortopathy, who manifested with spontaneous intimal tear of descending thoracic aorta and contained aortic rupture. Both patients were managed by endovascular repair, with collaborative efforts of teams comprising interventional cardiologists and radiologists, and a vascular surgeon. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Rupture of vasa vasorum and intramural hematoma of the aorta: a changing paradigm

    OpenAIRE

    Adamastor Humberto Pereira

    2010-01-01

    A ruptura dos vasa vasorum tem sido reconhecida como uma das causas do hematoma intramural da aorta há 90 anos. Esta breve revisão apresenta sistematicamente a fisiologia desses vasos e o seu papel na fisiopatologia das alterações parietais da aorta que ocorrem na hipertensão arterial, na arteriosclerose e na síndrome aórtica aguda. A hipótese defendida aqui é a de que a ruptura dos vasa vasorum ocorre como um fenômeno secundário e não como um dos fatores causais na fisiopatologia do hematoma...

  9. Unexpected death caused by rupture of a dilated aorta in an adult male with aortic coarctation

    DEFF Research Database (Denmark)

    Leth, Peter Mygind; Knudsen, Peter Juel Thiis

    2015-01-01

    haematoma (1000 ml) in the pericardial sac. Cardiac hypertrophy (556 g) was observed in the patient, though no other cardiovascular abnormalities were found. Histological analysis showed cystic medial necrosis of the ascending aortic wall. A ruptured aneurysmal dilatation of the ascending aorta......Aortic coarctation (AC) is a congenital aortic narrowing. We describe for the first time the findings obtained by unenhanced post mortem computed tomography (PMCT) in a case where the death was caused by cardiac tamponade from a ruptured aneurysmal dilatation of the ascending aorta and the aortic...

  10. Ruptured penetrating ulcer of the ascending aorta with pulmonary artery compression.

    Science.gov (United States)

    Okiwelu, Ngozichukwuka; Finn, Chris; Vanden Driesen, Rohan; Sanders, Lucas; Joshi, Pragnesh

    2016-03-01

    Pulmonary artery involvement has been reported in various degrees of complicated dissection of the ascending aorta. The prognosis remains poor without high-risk surgical intervention, but conservative management can be considered in high-risk cases. We report a case of nonoperative management of an octogenarian who presented with a contained rupture of his proximal ascending aorta, likely from a penetrating atherosclerotic ulcer. It was complicated by extrinsic compression of the pulmonary trunk and transient pulmonary hypertension without features of acute right heart failure. He remained alive at the one-year follow-up. © The Author(s) 2014.

  11. Flow visualisation study of spiral flow in the aorta-renal bifurcation.

    Science.gov (United States)

    Fulker, David; Javadzadegan, Ashkan; Li, Zuming; Barber, Tracie

    2017-10-01

    The aim of this study was to analyse the flow dynamics in an idealised model of the aorta-renal bifurcation using flow visualisation, with a particular focus on the effect of aorta-to-renal flow ratio and flow spirality. The recirculation length was longest when there was low flow in the renal artery and smaller in the presence of spiral flow. The results also indicate that patients without spiral flow or who have low flow in the renal artery due to the presence of stenosis may be susceptible to heightened development of atherosclerotic lesions.

  12. A dosimetric study on slab-pinewood-slab phantom for developing the heterogeneous chest phantom mimicking actual human chest

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2017-01-01

    Full Text Available The aim is to study the density, isodose depths, and doses at different points in slab-pinewood-slab (SPS phantom, solid phantom SP34 (made up of polystyrene, and chest level of actual patient for developing heterogeneous chest phantom mimicking thoracic region of human body. A 6 MV photon beam of field size of 10 cm×10 cm was directed perpendicular to the surface of computed tomography (CT images of chest level of patient, SPS phantom, and SP34 phantom. Dose was calculated using anisotropic analytical algorithm. Hounsfield units were used to calculate the density of each medium. Isodose depths in all the three sets of CT images were measured. Variations between planned doses on treatment planning system (TPS and measured on linear accelerator (LA were calculated for three points, namely, near slab-pinewood interfaces (6 and 18 cm depths and 10 cm depth in SPS phantom and at the same depths in SP34 phantom. Density of pinewood, SP34 slabs, chest wall, lung, and soft tissue behind lung was measured as 0.329 ± 0.08, 0.999 ± 0.02, 0.898 ± 0.02, 0.291 ± 0.12, and 1.002 ± 0.03 g/cc, respectively. Depths of 100% and 90% isodose curves in all the three sets of CT images were found to be similar. Depths of 80%, 70%, 60%, 50%, and 40% isodose lines in SPS phantom images were found to be equivalent to that in chest images, while it was least in SP34 phantom images. Variations in doses calculated at 6, 10, and 18 cm depths on TPS and measured on LA were found to be 0.36%, 1.65%, and 2.23%, respectively, in case of SPS phantom, while 0.24%, 0.90%, and 0.93%, respectively, in case of SP34 slab phantom. SPS phantom seemed equivalent to the chest level of human body. Dosimetric results of this study indicate that patient-specific quality assurance can be done using chest phantom mimicking thoracic region of human body, which has been fabricated using polystyrene and pinewood.

  13. Phantom limb pain: a case of maladaptive CNS plasticity?

    Science.gov (United States)

    Flor, Herta; Nikolajsen, Lone; Staehelin Jensen, Troels

    2006-11-01

    Phantom pain refers to pain in a body part that has been amputated or deafferented. It has often been viewed as a type of mental disorder or has been assumed to stem from pathological alterations in the region of the amputation stump. In the past decade, evidence has accumulated that phantom pain might be a phenomenon of the CNS that is related to plastic changes at several levels of the neuraxis and especially the cortex. Here, we discuss the evidence for putative pathophysiological mechanisms with an emphasis on central, and in particular cortical, changes. We cite both animal and human studies and derive suggestions for innovative interventions aimed at alleviating phantom pain.

  14. Diagnosis of a perforating aneurysm of the aorta as late complication of patch aortoplasty by central venous DSA

    Energy Technology Data Exchange (ETDEWEB)

    Zitzmann, A.; Kreuzer, E.; Huber, R.M.; Kenn, R.W.; Pfeifer, K.J.

    1988-06-01

    11 years after patch aortoplasty due to coarctation of the aorta a 33 year-old-patient experienced two spontaneous haemoptyses. A centralvenous digital subtraction angiography demonstrated a large aneurysm of the proximal descending aorta penetrating the left upper lobe of the lung. The successful emergency surgical treatment consisted of implantation of a dacron-prothesis.

  15. CA-45(2+) MOVEMENTS INDUCED BY CA2+ CHLORIDE IN ISOLATED RAT AORTA UNDER K+-FREE CONDITIONS

    NARCIS (Netherlands)

    WERMELSKIRCHEN, D; NEBEL, U; WIRTH, A; WILFFERT, B

    1991-01-01

    Increasing the extracellular Ca2+ concentration induced a dihydropyridine-insensitive contraction in the isolated rat aorta bathed in K+-free solution. To obtain further insight into the mechanism of this contraction Ca-45(2+) uptake measurements were carried out with isolated rat aorta. Increasing

  16. 45Ca2+movements induced by Ca2+chloride in isolated rat aorta under K+-free conditions

    NARCIS (Netherlands)

    Wermelskirchen, D.; Nebel, U.; Wirth, A.; Wilffert, B.

    1991-01-01

    Increasing the extracellular Ca2+concentration induced a dihydropyridine-insensitive contraction in the isolated rat aorta bathed in K+-free solution. To obtained further insight into the mechanisms of this contraction45Ca2+uptake measurements were carried out with isolated rat aorta. Increasing the

  17. Efficacy of progressive muscle relaxation, mental imagery, and phantom exercise training on phantom limb: a randomized controlled trial.

    Science.gov (United States)

    Brunelli, Stefano; Morone, Giovanni; Iosa, Marco; Ciotti, Cristina; De Giorgi, Roberto; Foti, Calogero; Traballesi, Marco

    2015-02-01

    To evaluate the reduction in phantom pain and sensation with combined training of progressive muscle relaxation, mental imagery, and phantom exercises. Randomized controlled prospective trial with 2 parallel groups. Amputee unit of a rehabilitation hospital. Subjects with unilateral lower limb amputation (N=51) with phantom limb pain (PLP) and/or phantom limb sensation (PLS). The experimental group performed combined training of progressive muscle relaxation, mental imagery, and phantom exercises 2 times/wk for 4 weeks, whereas the control group had the same amount of physical therapy dedicated to the residual limb. No pharmacological intervention was initiated during the trial period. The Prosthesis Evaluation Questionnaire and the Brief Pain Inventory were used to evaluate changes over time in different aspects (intensity, rate, duration, and bother) of PLS and PLP. Blind evaluations were performed before and after treatment and after 1-month follow-up. The experimental group showed a significant decrease over time in all the Prosthesis Evaluation Questionnaire domains (in terms of both PLS and PLP; Pprogressive muscle relaxation, mental imagery, and modified phantom exercises should be taken into account as a valuable technique to reduce phantom limb pain and sensation. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  18. Design and characterization of a device to quantify the magnetic drug targeting efficiency of magnetic nanoparticles in a tube flow phantom by magnetic particle spectroscopy

    Science.gov (United States)

    Radon, Patricia; Löwa, Norbert; Gutkelch, Dirk; Wiekhorst, Frank

    2017-04-01

    The aim of magnetic drug targeting (MDT) is to transfer a therapeutic drug coupled to magnetic nanoparticles (MNP) to desired disease locations (e.g. tumor region) with the help of magnetic field gradients. To transfer the MDT approach into clinical practice a number of important issues remain to be solved. We developed and characterized an in-vitro flow phantom to provide a defined and reproducible MDT environment. The tube system of the flow phantom is directed through the detection coil of a magnetic particle spectroscopy (MPS) device to determine the targeting efficiency. MPS offers an excellent temporal resolution of seconds and an outstanding specific sensitivity of some nanograms of iron. In the flow phantom different MNP types, magnet geometries and tube materials can be employed to vary physical parameters like diameter, flow rate, magnetic targeting gradient, and MNP properties.

  19. Cosmological perturbations on the Phantom brane

    CERN Document Server

    Bag, Satadru; Shtanov, Yuri; Sahni, Varun

    2016-01-01

    We obtain a closed system of equations for scalar perturbations in a multi-component braneworld. Our braneworld possesses a phantom-like equation of state at late times, $w_{\\rm eff} < -1$, but no big-rip future singularity. In addition to matter and radiation, the braneworld possesses a new effective degree of freedom - the 'Weyl fluid' or 'dark radiation'. Setting initial conditions on super-Hubble spatial scales at the epoch of radiation domination, we evolve perturbations of radiation, pressureless matter and the Weyl fluid until the present epoch. We observe a gradual decrease in the amplitude of the Weyl-fluid perturbations after Hubble-radius crossing, which results in a negligible effect of the Weyl fluid on the evolution of matter perturbations on spatial scales relevant for structure formation. Consequently, the quasi-static approximation of Koyama and Maartens provides a good fit to the exact results during the matter-dominated epoch. We find that the late-time growth of density perturbations on...

  20. Protective effect of soybeans as protein source in the diet against cadmium-aorta redox and morphological alteration

    Energy Technology Data Exchange (ETDEWEB)

    Pérez Díaz, Matías F.F.; Acosta, Mariano; Mohamed, Fabián H.; Ferramola, Mariana L.; Oliveros, Liliana B.; Gimenez, María S., E-mail: marisofigime44@gmail.com

    2013-11-01

    We investigated the effects of cadmium exposition on thoracic aorta redox status and morphology, and the putative protective effect of soybeans in the diet. Male Wistar rats were separated into 6 groups: 3 fed with a diet containing casein and 3 containing soybeans, as protein source. Within each protein group, one was given tap water (control) and the other two tap water containing 15 and 100 ppm of Cd{sup 2+}, respectively, for two months. In rats fed with casein diet, 15 ppm of Cd induced an increase of thiobarbituric acid-reactive substances (TBARS), and of the catalase (CAT) and glutathione peroxidase (GPx) activities, which were even higher with 100 ppm of Cd{sup 2+}, in aorta. Also, 100 ppm Cd{sup 2+} exposure increased superoxide dismutase (CuZnSOD) activity; CAT, GPX, SOD, Nrf2 and metallothioneine II mRNA expressions and CAT, GPx and NOX-2 protein levels, compared with control. Aorta endothelial and cytoplasmic alterations were observed. However, with the soybeans diet, 15 and 100 ppm of Cd{sup 2+} did not modify TBARS levels; CAT, GPX and Nrf2 mRNA expressions; CAT, GPx and NOX-2 protein; and the aorta morphology, compared with control. The soybean diet attenuates the redox changes and protects against morphological alterations induced, in a dose-dependent way, by Cd in aorta. - Highlights: • Under casein diet, 100 ppm Cd{sup 2+} in drinking water induces oxidative stress in aorta. • Under casein diet, 100 ppm Cd{sup 2+} increases Nrf2, MT II and NOX2 expressions in aorta. • Under casein diet, 100 ppm Cd{sup 2+} induces morphological changes in rat aorta. • The soybean diet attenuates the redox changes induced by Cd in rat aorta. • The soybean diet attenuates morphological alterations induced by Cd in rat aorta.

  1. Bioassay Phantoms Using Medical Images and Computer Aided Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Dr. X. Geroge Xu

    2011-01-28

    A radiation bioassay program relies on a set of standard human phantoms to calibrate and assess radioactivity levels inside a human body for radiation protection and nuclear medicine imaging purposes. However, the methodologies in the development and application of anthropomorphic phantoms, both physical and computational, had mostly remained the same for the past 40 years. We herein propose a 3-year research project to develop medical image-based physical and computational phantoms specifically for radiation bioassay applications involving internally deposited radionuclides. The broad, long-term objective of this research was to set the foundation for a systematic paradigm shift away from the anatomically crude phantoms in existence today to realistic and ultimately individual-specific bioassay methodologies. This long-term objective is expected to impact all areas of radiation bioassay involving nuclear power plants, U.S. DOE laboratories, and nuclear medicine clinics.

  2. A solid tissue phantom for photon migration studies

    Energy Technology Data Exchange (ETDEWEB)

    Cubeddu, Rinaldo; Pifferi, Antonio; Taroni, Paola; Torricelli, Alessandro; Valentini, Gianluca [CEQSE-CNR and Dipartimento di Fisica, Politecnico di Milano, Piazza L da Vinci 32, 20133 Milano (Italy)

    1997-10-01

    A solid tissue phantom made of agar, Intralipid and black ink is described and characterized. The preparation procedure is fast and easily implemented with standard laboratory equipment. An instrumentation for time-resolved transmittance measurements was used to determine the optical properties of the phantom. The absorption and the reduced scattering coefficients are linear with the ink and Intralipid concentrations, respectively. A systematic decrease of the reduced scattering coefficient dependent on the agar content is observed, but can easily be managed. The phantom is highly homogeneous and shows good repeatability among different preparations. Moreover, agar inclusions can be easily embedded in either solid or liquid matrixes, and no artefacts are caused by the solid - solid or solid - liquid interfaces. This allows one to produce reliable and realistic inhomogeneous phantoms with known optical properties, particularly interesting for studies on optical imaging through turbid media. (author)

  3. Prototype phantoms for characterization of ultralow field magnetic resonance imaging.

    Science.gov (United States)

    Boss, Michael A; Mates, John A B; Busch, Sarah E; SanGiorgio, Paul; Russek, Stephen E; Buckenmaier, Kai; Irwin, Kent D; Cho, Hsiao-Mei; Hilton, Gene C; Clarke, John

    2014-12-01

    Prototype phantoms were designed, constructed, and characterized for the purpose of calibrating ultralow field magnetic resonance imaging (ULF MRI) systems. The phantoms were designed to measure spatial resolution and to quantify sensitivity to systematic variation of proton density and relaxation time, T1 . The phantoms were characterized first with conventional magnetic resonance scanners at 1.5 and 3 T, and subsequently with a prototype ULF MRI scanner between 107 and 128 μT . The ULF system demonstrated a 2-mm spatial resolution and, using T1 measurements, distinguished aqueous solutions of MnCl2 differing by 20 μM  [Mn(2+) ]. The prototype phantoms proved well-matched to ULF MRI applications, and allowed direct comparison of the performance of ULF and clinical systems. © 2013 Wiley Periodicals, Inc.

  4. Phantom dark ghost in Einstein-Cartan gravity

    Science.gov (United States)

    Chang, Yu-Chiao; Bouhmadi-López, Mariam; Chen, Pisin

    2017-05-01

    A class of dynamical dark energy models is constructed through an extended version of fermion fields corresponding to phantom dark ghost spinors, which are spin 1/2 with mass dimension 1. We find that if these spinors interact with torsion fields in a homogeneous and isotropic universe, then it does not imply any future dark energy singularity or any abrupt event, though the fermion has a negative kinetic energy. In fact, the equation of state of this dark energy model will asymptotically approach the value w=-1 from above without crossing the phantom divide and inducing therefore a de Sitter state. Consequently, we expect the model to be stable because no real phantom fields will be created. At late time, the torsion fields will vanish as the corresponding phantom dark ghost spinors dilute. As would be expected, intuitively, this result is unaffected by the presence of cold dark matter although the proof is not as straightforward as in general relativity.

  5. Suggested guidelines for treatment of phantom limb pain.

    Science.gov (United States)

    Sherman, R A; Tippens, J K

    1982-12-01

    Eighty to ninety percent of amputees have been shown to suffer significant amounts of phantom limb pain in contrast to the widely accepted level of about 5%. Surveys of the literature, of physicians actively treating phantom pain, and of over 3,000 American veteran amputees have shown that most of the usual treatments are not efficacious when followups of a year or more are done. A diagnostic and therapeutic schemata is presented, which incorporates the above surveys, research, and clinical experience into a unified approach optimizing the few treatments showing a reasonable hope of long term success. Every effort is made to identify the source of pain being referred into the phantom. Stump, back, prosthetic, and other physical problems are corrected prior to initiation of other treatments, including EMG or temperature feedback from the stump, sympathetic system alteration, modulation of anxiety and depression, TENS, and ultrasound. Key indexing terms: phantom pain, treatment, amputees, referred pain. Copyright 2013, SLACK Incorporated.

  6. Fabrication and characterization of biological tissue phantoms with embedded nanoparticles

    Science.gov (United States)

    Skaptsov, A. A.; Ustalkov, S. O.; Mohammed, A. H. M.; Savenko, O. A.; Novikova, A. S.; Kozlova, E. A.; Kochubey, V. I.

    2017-11-01

    Phantoms are imitations of biological tissue, which are used for modelling of the light propagation in biological tissues. Carrying out any biophysical experiments requires an indispensable constancy of the initial experiment conditions. The use of solid undegradable phantoms is the basis to obtain reliable reproducible experimental results. The fabrication of biological tissues phantoms containing high absorbance or fluorescence nanoparticles and corresponding to specific mechanical, optical properties is an actual task. This work describes development, fabrication and characterization of such solid tissue phantoms with embedded CdSe/ZnS quantum dots, gold and upconversion nanoparticles. Luminescence of samples with CdSe/ZnS quantum dots and upconversion nanoparticles were recorded. A sample of gold nanorods was analyzed using thermal gravimetric analysis. It can be concluded that the samples are well suited for experiments on laser thermolysis.

  7. Phantom dark ghost in Einstein-Cartan gravity

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yu-Chiao [National Taiwan University, Department of Physics, Taipei (China); National Taiwan University, LeCosPA, Taipei (China); Bouhmadi-Lopez, Mariam [University of the Basque Country UPV/EHU, Department of Theoretical Physics, P.O. Box 644, Bilbao (Spain); Basque Foundation for Science, IKERBASQUE, Bilbao (Spain); Chen, Pisin [National Taiwan University, Department of Physics, Taipei (China); National Taiwan University, LeCosPA, Taipei (China); National Taiwan University, Graduate Institute of Astrophysics, Taipei (China); SLAC National Accelerator Laboratory, Stanford University, Kavli Institute for Particle Astrophysics and Cosmology, Stanford, CA (United States)

    2017-05-15

    A class of dynamical dark energy models is constructed through an extended version of fermion fields corresponding to phantom dark ghost spinors, which are spin 1/2 with mass dimension 1. We find that if these spinors interact with torsion fields in a homogeneous and isotropic universe, then it does not imply any future dark energy singularity or any abrupt event, though the fermion has a negative kinetic energy. In fact, the equation of state of this dark energy model will asymptotically approach the value w = -1 from above without crossing the phantom divide and inducing therefore a de Sitter state. Consequently, we expect the model to be stable because no real phantom fields will be created. At late time, the torsion fields will vanish as the corresponding phantom dark ghost spinors dilute. As would be expected, intuitively, this result is unaffected by the presence of cold dark matter although the proof is not as straightforward as in general relativity. (orig.)

  8. Experiencia en el manejo endovascular para el tratamiento de la aorta torácica Experience in endovascular management for thoracic aorta treatment

    Directory of Open Access Journals (Sweden)

    Juan G Barrera

    2007-12-01

    Full Text Available Antecedentes: el tratamiento endovascular ofrece la posibilidad de cubrir el origen de la disección y evitar que progrese hasta aneurisma de la aorta, y con ello demuestra una reducción en la mortalidad hasta del 16%. Objetivo: evaluar los resultados quirúrgicos en términos de morbi-mortalidad de los pacientes sometidos a manejo endovascular de las lesiones de la aorta torácica en la Fundación Cardiovascular de Colombia desde 2003 hasta 2005. Diseño-método: estudio longitudinal tipo descriptivo retrospectivo, en el que se evaluaron las historias clínicas de todos los pacientes sometidos a manejo endovascular de patología toracoabdominal; en éste sólo se incluyeron los pacientes con procedimientos de la aorta torácica, desde 2003 hasta 2005. El análisis de los datos se realizó en Stata/SE 8,0. Resultados: se realizaron procedimientos de aorta torácica en 16 pacientes. El 75% de los pacientes eran hombres con edad promedio de 55,9 ± 12,6 años. El 87,5% (14 pacientes presentaban disección aórtica tipo A o B; un paciente transección traumática de la aorta y un paciente aneurisma de aorta torácica descendente. Las disecciones agudas se presentaron en 78,6% (11 pacientes y las crónicas en 21,4% (3 pacientes. El promedio de endoprótesis usadas fue de 2,8 ± 1. La estancia en la unidad de cuidados intensivos fue de 3 ± 2,7 días. El 81,3% de los pacientes no presentaron complicaciones mayores. La mortalidad fue del 18,7% (3 pacientes. A todos se les realizó control post-operatorio con tomografía axial computarizada, con evolución satisfactoria. Conclusión: de acuerdo con los reportes de la literatura con mayor casuística, se considera que el manejo endovascular para el tratamiento de la disección, aneurisma o trauma aórtico es un procedimiento confiable que disminuye la morbi-mortalidad.Antecedents: endovascular treatment has the possibility of covering the dissection origin and to avoid its progression to aortic

  9. Motor cortex changes after amputation are modulated by phantom limb motor control rather than pain

    DEFF Research Database (Denmark)

    Raffin, Estelle E.; Pascal, Giraux,; Karen, Reilly,

    retains a residual M1-c activity when amputees perform phantom limb movements (4-5). Except a correlation between phantom limb pain and M1-c expansion of the face (2-3), the relationship between the ability to voluntary move the phantom hand, the level of phantom limb pain, the degree of M1-c...

  10. Nitric oxide transport in normal human thoracic aorta: effects of hemodynamics and nitric oxide scavengers.

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    Full Text Available Despite the crucial role of nitric oxide (NO in the homeostasis of the vasculature, little quantitative information exists concerning NO transport and distribution in medium and large-sized arteries where atherosclerosis and aneurysm occur and hemodynamics is complex. We hypothesized that local hemodynamics in arteries may govern NO transport and affect the distribution of NO in the arteries, hence playing an important role in the localization of vascular diseases. To substantiate this hypothesis, we presented a lumen/wall model of the human aorta based on its MRI images to simulate the production, transport and consumption of NO in the arterial lumen and within the aortic wall. The results demonstrated that the distribution of NO in the aorta was quite uneven with remarkably reduced NO bioavailability in regions of disturbed flow, and local hemodynamics could affect NO distribution mainly via flow dependent NO production rate of endothelium. In addition, erythrocytes in the blood could moderately modulate NO concentration in the aorta, especially at the endothelial surface. However, the reaction of NO within the wall could only slightly affect NO concentration on the luminal surface, but strongly reduce NO concentration within the aortic wall. A strong positive correlation was revealed between wall shear stress and NO concentration, which was affected by local hemodynamics and NO reaction rate. In conclusion, the distribution of NO in the aorta may be determined by local hemodynamics and modulated differently by NO scavengers in the lumen and within the wall.

  11. Identification of 2 novel genes developmentally regulated in the mouse aorta-gonad-mesonephros region

    NARCIS (Netherlands)

    C. Orelio; E.A. Dzierzak (Elaine)

    2003-01-01

    textabstractThe first adult-repopulating hematopoietic stem cells (HSCs) emerge in the mouse aorta-gonad-mesonephros (AGM) region at embryonic day 10.5 prior to their appearance in the yolk sac and fetal liver. Although several genes are implicated in the regulation of HSCs, there

  12. Large mobile thrombus in non-atherosclerotic thoracic aorta as the source of peripheral arterial embolism

    Directory of Open Access Journals (Sweden)

    Brkovic Zoran

    2005-11-01

    Full Text Available Abstract The presence of thrombi in the atherosclerotic and/or aneurysmatic aorta with peripheral arterial embolism is a common scenario. Thrombus formation in a morphologically normal aorta, however, is a rare event. A 50 years old woman was admitted to the mergency department for pain, coldness, and anesthesia in the the left foot. She had a 25 years history of cigarette smoking, a history of postmenopausal hormone replacement therapy (HRT, hypercholesterolemia and hyperfibrinogenemia. An extensive serologic survey for hypercoagulability, including antiphospholipid antibodies, and vasculitis disorders was negative. Transesophageal echocardiography revealed a large, pedunculated and hypermobile thrombus attached to the aortic wall 5 cm distal of the left subclavian artery. The patient was admitted to the surgery department, where a 15 cm long fresh, parietal thrombus could be removed from the aorta showing no macroscopic wall lesions or any other morphologic abnormalities. This case report demonstrates the possibility of evolving a large, pedunculated thrombus in a morphologically intact aorta in a postmenopausal woman with thrombogenic conditions such as hyperfibrinogenemia, hypercholesterolemia, smoking and HRT. For these patients, profiling the individual risk and weighing the benefits against the potential risks is warranted before prescribing HRT.

  13. Layer-specific residual deformations and uniaxial and biaxial mechanical properties of thoracic porcine aorta.

    Science.gov (United States)

    Peña, Juan A; Martínez, Miguel A; Peña, Estefanía

    2015-10-01

    In this paper we hypothesize that the layer-separated residual stresses and mechanical properties of layer-separated thoracic aorta arteries may be dependent on arterial location of the vessel. To demonstrate any possible position differences, we measured the axial pre-stretch and opening angle and performed uniaxial and biaxial tests under physiological loads to study the mechanical behavior of both intact and layer-separated porcine aortic samples taken from thoracic region. In addition, we also provided constitutive parameters for each layer that can be used by biomedical engineers for investigating better therapies and developing artery-specific devices. We found that the opening angle for whole artery and adventitia layer are smaller and intima greater for proximal segments than for the distal thoracic ones. For the axial pre-stretch, our results showed significant increased values of the stretch ratios with location. We found that lower thoracic samples are stiffer than upper ones with the most important differences corresponding to those between the proximal and distal behaviors in the circumferential direction. The anisotropy represented by the different circumferential and longitudinal response is more remarkable in lower thoracic aorta. Finally, adventitia and intima samples present a tendency to be stiffer and more isotropic than the corresponding media samples in both directions for upper thoracic aorta and to be more anisotropic for lower thoracic aorta. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Imaging of the distal ascending aorta using modified transesophageal echocardiography in cardiac surgery

    NARCIS (Netherlands)

    van Zaane, B.|info:eu-repo/dai/nl/311475361

    2009-01-01

    Epiaortic ultrasound scanning of the ascending aorta is a safe and useful method to detect atherosclerosis in patients undergoing cardiac surgery. The use of epiaortic ultrasound can lead to modifications of the surgical technique, which effectively reduces the post-operative incidence of stroke in

  15. Medical image of the week: atherosclerotic aneurysm of aortic arch and descecnding thoracic aorta

    Directory of Open Access Journals (Sweden)

    Parasram M

    2016-02-01

    Full Text Available No abstract available. Article truncated after 150 words. A 94-year-old Spanish-speaking woman presented to the hospital with intermittent episodes of dyspnea and abdominal pain for one week. Her past medical history was notable for 30 pack-year smoking history and hypertension, which was reportedly controlled with medical therapy. Physical exam showed trace peripheral edema bilaterally, intact peripheral pulses, and a mild abdominal bruit. Work up at the emergency department revealed a non-ST elevation myocardial infarction with troponin T of 0.34 ng/mL but no ST-wave abnormality on electrocardiography. Chest x-ray displayed an incidental thoracic aneurysm (Figure 1. Chest computed tomography with contrast demonstrated a continuous aneurysm of the aortic arch and descending thoracic aorta with diameters measuring 6.8 cm and 6 cm, respectively (Figure 2A and 2B. Eccentric thrombi are noted in the aortic arch and the descending aorta. Interestingly, the distal descending thoracic aorta curves as it transitions to the abdominal aorta, which is evidence of a tortuous descending ...

  16. 198. Extubación inmediata tras cirugía de aorta ascendente

    Directory of Open Access Journals (Sweden)

    J.A. Arnaldo

    2010-01-01

    Conclusiones: La extubación inmediata en pacientes sometidos a cirugía de aorta ascendente es viable y segura, incluso en pacientes intervenidos con parada cardiocirculatoria. La necesidad de reintubación es rara, y está relacionada con el sangrado. Facilita la deambulación precoz y disminuye el tiempo de estancia en UCI.

  17. Mycotic aneurysm of the aorta as an unusual complication of coronary angiography

    NARCIS (Netherlands)

    van der Wal, H.; van Geel, P. P.; de Boer, R. A.

    Introduction: Mycotic aneurysm of the aorta is a rare diagnosis with high mortality. Report: Percutaneous coronary intervention was complicated by bacteraemia with Staphylococcus aureus and a mycotic aortic aneurysm, an unusual complication of coronary angiography. Combining CT and PET scan showed a

  18. Effect of calmodulin antagonists on contraction and45Ca movements in rat aorta

    NARCIS (Netherlands)

    Wermelskirchen, D.; Koch, P.; Wilhelm, D.; Nebel, U.; Leidig, A.; Wilffert, B.; Peters, Thies

    1989-01-01

    To study the selectivity of calmodulin antagonists it was assumed that they should inhibit noradrenaline (NA)- and K+-induced contractions similarly without an accompanying inhibition of45Ca uptake. Therefore, in isolated rat aorta the effects of W-7, calmidazolium and trifluoperazine on contraction

  19. Coarctatio aortae: 40 års opfølgning efter kirurgisk korrektion - sekundaerpublikation

    DEFF Research Database (Denmark)

    Høimyr, Hilde; Pedersen, Thais A L; Christensen, Thomas D

    2009-01-01

    Coarctation of the aorta (CoA) was previously considered cured after surgical repair. Among 229 patients operated for CoA in Aarhus between 1965 and 1985, 14 died at surgery and 35 died during 20-40 years of follow-up, mainly due to cardiovascular disease. The mortality among CoA patients was 4...

  20. Effect of camelina oil on the structure of aortas in rats

    DEFF Research Database (Denmark)

    Pawlowska, Marta; Harrison, Adrian Paul; Piersiak, Tomasz

    2016-01-01

    in tension. Aortic wall elasticity was measured in duplicate. Samples of the aorta were also prepared for histology (total aortic wall thickness, thickness of tunica intima and media, thickness of adventitia) and immunohistochemistry (volume and mean fluorescence intensity of collagens I and III and elastin...

  1. Cholesterol uptake in the mouse aorta increases during Chlamydia pneumoniae infection.

    Science.gov (United States)

    Edvinsson, Marie; Tallkvist, Jonas; Nyström-Rosander, Christina; Ilbäck, Nils-Gunnar

    2017-01-01

    Chlamydia pneumoniae has been suggested as a stimulator of the atherosclerotic process. Mice fed a normal diet were infected intranasally with C. pneumoniae and given one intraperitoneal injection of 14C-cholesterol tracer per day for 12 days. Bacteria were demonstrated in the aorta in the early phase of infection and in lungs and liver throughout the study period of 20 days. 14C-cholesterol was not affected in the heart but increased in the blood, liver and aorta on day 4 when the infection was clinically most severe. Furthermore, on day 20 14C-cholesterol tended to be increased in the aorta. Accordingly, copper- and zinc levels and expressions of the infection biomarkers Cxcl2 and Ifng increased in the liver on day 4 with a tendency of increased of copper, zinc and Ifng on day 20. In mice where bacteria could be cultivated from the lungs, expressions of cholesterol transporters Abca1 and Idol were both increased in the liver on day 4. The increased levels of 14C-cholesterol in blood and aorta together with increased Abca1 and Idol in the liver during C. pneumoniae infection in mice fed a normal diet suggest that this pathogen may have a role in the initiation of the atherosclerotic process. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Relationship between aneurism of ascending part of aorta and syndrome of connective tissue dysplasia

    Directory of Open Access Journals (Sweden)

    Osovska N.Yu.

    2014-11-01

    Full Text Available The paper identifies the main reasons for the development of an aneurysm of the ascending aorta and predictors of its complications in patients of all ages. To determine the cause and age-associated risk factors for aneurysms there were examined 154 patients with the presence of the expansion of the root and / or ascending aorta of more than 40 mm, according to echocardiographic examination. Patients were divided into 4 categories by age: 18-29 years, 30-44 years 45-59 years 60-74 years. Instrumental methods of examination: echocardiography, ECG, ECG monitoring and blood pressure, heart rate variability, ultrasound of internal organs were used. Syndrome of connective tissue dysplasia was established according to the criteria of the working group of the British Society of Rheumatology. Joint hypermobility syndrome was determined according to the Brayton criteria. Statistical processing was carried out by methods of variation statistic program StatSoft "Statistica" v.10.0. It was established that in young and middle aged patients the cause of aneurysm of ascending aorta more often is connective tissue dysplasia syndrome. In older patients the main cause of aneurysm of ascending aorta is associated with left ventricular hypertrophy and decreased contractile function of the heart.

  3. Vascular dysfunctions in the isolated aorta of double-transgenic hypertensive mice developing aortic aneurysm

    DEFF Research Database (Denmark)

    Waeckel, L.; Badier-Commander, C.; Damery, T.

    2015-01-01

    not affected in BLSL and AR. However, in ARSL, endothelium-dependent relaxations (acetylcholine, UK-14304) were significantly reduced, and this dysfunction was similar in aortae without or with aneurysms. The endothelial impairment was unaffected by catalase, superoxide-dismutase mimetic, radical scavengers...

  4. High level cross of the esophagus with the descending aorta in scoliosis: CT study

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Koji; Kikuno, Motoyuki; Hyodoh, Hideki [Jichi Medical School Hospital, Minamikawachi-machi, Tochigi-ken (Japan)] [and others

    1996-05-01

    The esophagus occasionally crosses the descending aorta at an unusually high level (3-5 cm inferior to the carina) in right-sided scoliosis. The purpose of this study was to analyze the mechanism of this finding. We prospectively evaluated thoracic CT scans in 30 patients with right-sided scoliosis. We assessed the alterations in the positions of the esophagus and the descending aorta by the thoracic deformity. The descending aorta followed the scoliotic curve of the spine in 26 (87%) patients. The esophagus followed the scoliotic curve of the spine in 14 (47%) patients and did not in 16 (53%). The anteroposterior diameter of the thorax in the former group was significantly smaller than that in the latter (p < 0.01). High level cross of both structures was identified in 14 (47%) patients, and all of them belonged to the group in which the esophagus did not follow the scoliotic curve of the spine. The unusual high level cross of the esophagus with the descending aorta occasionally seen in scoliosis is due to a difference in the positional alterations of the two structures resulting from the scoliosis. 6 refs., 3 figs.

  5. Non muscle cells in the tunica media of the aorta | Ogeng'o ...

    African Journals Online (AJOL)

    Knowledge of cellular composition of aortic tunica media is important to improve understanding of aortic pathology. The aorta of 6 healthy male goats was studied by electron microscopy to elucidate cell types within the tunica media. Glutaraldehyde fixed specimens were processed for durcupan embedding and sectioning, ...

  6. Blunt traumatic aortic rupture of the proximal ascending aorta repaired by resection and direct anastomosis.

    Science.gov (United States)

    Harmouche, Majid; Slimani, Eric Karim; Heraudeau, Adeline; Verhoye, Jean-Philippe

    2013-10-01

    Traumatic aortic injury represents 15% of motor vehicle related deaths with death occurring at the scene in 85% of the cases. Aortic disruptions usually occur at the isthmus in a transverse fashion with all three of the aortic layers being involved. Herein, we report the case of a 68-year old man with no prior medical history who was struck by a vehicle while riding his bicycle. The ruptured segment of aorta was resected circumferentially and interrupted horizontal mattress pledgeted prolene sutures were used to ensure full thickness aortic integrity of the proximal and distal aortic segments. The aorta was closed with a single-layer technique using 4/0 prolene suture. There were no postoperative complications and patient was discharged on Day 44. The case here discussed demonstrates a rare presentation of blunt aortic injury. The proximal ascending aorta is an unusual site of transection following blunt trauma with few reports in the literature. We were able to repair the aorta with direct suture, thus avoiding the use of artificial material.

  7. Ultrasonographic measurement of canine aorta and aortic inlet before and after administration of Propofol

    Directory of Open Access Journals (Sweden)

    Gh Assadnassab

    2008-11-01

    Full Text Available Induction of safe anesthesia is an important task in veterinary medicine. One of the drugs used for anesthesia is Propofol. In this study, five healthy German shepherd dogs were selected and standard echocardiographic procedure from the right parasternal axis view conducted to observe the aorta and aortic inlet in B-mode and M-mode display formats before and after anesthesia with 6 mg/kg of Propofol. In the short axis view, the dorso-ventral and transverse diameter of the aorta in B-mode display and in the long axis view, the systolic and diastolic diameter of the aortic inlet in M-mode display were measured. The average dorso-ventral and transverse diameter of aorta in normal dogs was 22.77±1.49 mm and 20.75± 1.34 mm respectively while in anesthetized dogs these figures were 22.02±0.87 mm and 20.64±1.19 mm respectively which were not significantly different from normal dogs. However, the mean diameter of aorta inlet in M-mode display during systole and diastole was 15.62±0.84 mm and 15.31±0.68 mm respectively in normal dogs and for anesthetized animals these figures were 21.60±1.23 mm during systole and 19.70±0.68 mm during diastole which were significantly different compared with the normal dogs.

  8. Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via α2-Adrenoceptor

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Rafaela de Fátima Ferreira [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil); Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Taipeiro, Elane de Fátima [Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Queiroz, Regina Helena Costa [Departamento de Análise Clínica - Toxicológica e Ciência de Alimentos - Faculdade de Ciências Farmacêuticas - USP, São Paulo, SP (Brazil); Chies, Agnaldo Bruno [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil); Laboratório de Farmacologia - Faculdade de Medicina de Marília - FAMEMA, SP (Brazil); Cordellini, Sandra, E-mail: cordelli@ibb.unesp.br [Departamento de Farmacologia - Instituto de Biociências - Universidade Estadual Paulista - UNESP - São Paulo, SP (Brazil)

    2014-03-15

    Stress and ethanol are both, independently, important cardiovascular risk factors. To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure.

  9. Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via α2-Adrenoceptor

    Science.gov (United States)

    Baptista, Rafaela de Fátima Ferreira; Taipeiro, Elane de Fátima; Queiroz, Regina Helena Costa; Chies, Agnaldo Bruno; Cordellini, Sandra

    2014-01-01

    Background Stress and ethanol are both, independently, important cardiovascular risk factors. Objective To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Methods Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Results Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Conclusion Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure. PMID:24676223

  10. Morphometric Properties of the Thoracic Aorta of Warmblood and Friesian Horses with and without Aortic Rupture

    NARCIS (Netherlands)

    Saey, V; Ploeg, M; Delesalle, C; van Loon, G; Gröne, A; Ducatelle, R; Duchateau, L; Chiers, K

    2016-01-01

    Rupture of the aorta is much more common in Friesians compared with other breeds of horse. Rupture always occurs adjacent to the scar of the ligamentum arteriosum. Previous histological examination of ruptured aortic walls suggested the presence of an underlying connective tissue disorder.

  11. [The diagnosis of traumatic rupture of the aorta. 36 cases (author's transl)].

    Science.gov (United States)

    Motin, J; Latarjet, J; Cognet, J B; Clermont, C; Mazoyer, B; Tran, M V; Juillard, F; Neidhardt, J H

    1980-10-18

    Thirty six cases of traumatic rupture of the thoracic aorta (TRA) were diagnosed during the hours following the accident responsible. Rupture was situated at the aortic isthmus in 32 cases, the ascending aortic in 2 cases, the arch of the aorta in 1 case and the descending sub-isthmic aorta in 1 case. Ten patients had no rib fractures. In 16 patients not undergoing surgery before 20th hour after the trauma, 10 died of secondary rupture. The course of a TRA is thus unpredictable and it is of fundamental importance to make the diagnosis and undertake appropriate surgical treatment immediately. The essential clinical sign is a difference in blood pressure between the upper and lower limbs (6 6%). Radiological signs suggestive of TRA are, in a plain PA chest film : widening of the mediastinum (92 %), poor visibility of the knuckle of the aorta (89 %), left haemothorax (67 %), deviation of the trachea to the right (55 %) and lowering of the left main bronchus (47 %). The slightest suspicion of a TRA should lead to aortic angiography preferably via an arterial approach (humeral or femoral), or intravenously. Surgical treatment should not be delayed.

  12. Vector flow imaging of the ascending aorta. Are systolic backflow and atherosclerosis related?

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Møller-Sørensen, Hasse; Kjaergaard, Jesper

    2015-01-01

    understand the aortic flow and especially the complex flow patterns, the ascending aorta was scanned intraoperatively in patients undergoing heart surgery using the angle-independent vector velocity ultrasound method Transverse Oscillation (TO). The primary aim of the study was to analyze systolic backflow...... systolic velocities (pindicates that vector flow...

  13. Heterogeneous Breast Phantom Development for Microwave Imaging Using Regression Models

    OpenAIRE

    Camerin Hahn; Sima Noghanian

    2012-01-01

    As new algorithms for microwave imaging emerge, it is important to have standard accurate benchmarking tests. Currently, most researchers use homogeneous phantoms for testing new algorithms. These simple structures lack the heterogeneity of the dielectric properties of human tissue and are inadequate for testing these algorithms for medical imaging. To adequately test breast microwave imaging algorithms, the phantom has to resemble different breast tissues physically and in terms of dielectri...

  14. Dedicated phantom materials for spectral radiography and CT.

    Science.gov (United States)

    Shikhaliev, Polad M

    2012-03-21

    As x-ray imaging technology moves from conventional radiography and computed tomography (CT) to spectral radiography and CT, dedicated phantom materials are needed for spectral imaging. The spectral phantom materials should accurately represent the energy-dependent mass-attenuation coefficients of different types of tissues. Although tissue-equivalent phantom materials were previously developed for CT and radiation therapy applications, these materials are suboptimal for spectral radiography and CT; they are not compatible with contrast agents, do not represent many of the tissue types and do not provide accurate values of attenuation characteristics of tissue. This work provides theoretical framework and a practical method for developing tissue-equivalent spectral phantom materials with a required set of parameters. The samples of the tissue-equivalent spectral phantom materials were developed, tested and characterized. The spectral phantom materials were mixed with iodine, gold and calcium contrast agents and evaluated. The materials were characterized by CT imaging and x-ray transmission experiments. The fabricated materials had nearly identical densities, mass attenuation coefficients, effective atomic numbers and electron densities as compared to corresponding tissue materials presented in the ICRU-44 report. The experimental results have shown good volume uniformity and inter-sample uniformity (repeatability of sample fabrication) of the fabricated materials. The spectral phantom materials were fabricated under laboratory conditions from readily available and inexpensive components. It was concluded that the presented theoretical framework and fabrication method of dedicated spectral phantom materials could be useful for researchers and developers working in the new area of spectral radiography and CT. Independently, the results could also be useful for other applications, such as radiation therapy. © 2012 Institute of Physics and Engineering in Medicine

  15. Hubungan Phantom Vibration Syndrome Terhadap Sleep Disorder dan Kondisi Stress

    OpenAIRE

    Ajeng Yeni Setianingrum

    2017-01-01

    Phantom vibration syndrome is a condition where a person would feel the sensation of vibration of a cell phone as if there were incoming notification but the fact is not. This research investigated the relationship between phantom vibration syndromes, sleep disorder and stress condition. Questionnaires were distributed to 120 participants with age range 18 to 23 years old. Data of participants showed that all of participants using a smart mobile phone and 24% of them have more than one cell p...

  16. Caracterización de Phantoms por ultrasonidos

    OpenAIRE

    ORTÍ ANGLÉS, CARLOS

    2012-01-01

    El principal objetivo es el desarrollo de sistemas ultrasónicos que permitan medir con precisión distribuciones de los principales parámetros acústicos que caracterizan el comportamiento de los "Tejidos equivalentes" (Phantoms), empleados en laboratorio con el fin de identificar entre tejidos sano y enfermo mediante los ultrasonidos Ortí Anglés, C. (2012). Caracterización de Phantoms por ultrasonidos. http://hdl.handle.net/10251/17787. Archivo delegado

  17. Computational hybrid anthropometric paediatric phantom library for internal radiation dosimetry

    Science.gov (United States)

    Xie, Tianwu; Kuster, Niels; Zaidi, Habib

    2017-04-01

    Hybrid computational phantoms combine voxel-based and simplified equation-based modelling approaches to provide unique advantages and more realism for the construction of anthropomorphic models. In this work, a methodology and C++ code are developed to generate hybrid computational phantoms covering statistical distributions of body morphometry in the paediatric population. The paediatric phantoms of the Virtual Population Series (IT’IS Foundation, Switzerland) were modified to match target anthropometric parameters, including body mass, body length, standing height and sitting height/stature ratio, determined from reference databases of the National Centre for Health Statistics and the National Health and Nutrition Examination Survey. The phantoms were selected as representative anchor phantoms for the newborn, 1, 2, 5, 10 and 15 years-old children, and were subsequently remodelled to create 1100 female and male phantoms with 10th, 25th, 50th, 75th and 90th body morphometries. Evaluation was performed qualitatively using 3D visualization and quantitatively by analysing internal organ masses. Overall, the newly generated phantoms appear very reasonable and representative of the main characteristics of the paediatric population at various ages and for different genders, body sizes and sitting stature ratios. The mass of internal organs increases with height and body mass. The comparison of organ masses of the heart, kidney, liver, lung and spleen with published autopsy and ICRP reference data for children demonstrated that they follow the same trend when correlated with age. The constructed hybrid computational phantom library opens up the prospect of comprehensive radiation dosimetry calculations and risk assessment for the paediatric population of different age groups and diverse anthropometric parameters.

  18. Prevalent hallucinations during medical internships: phantom vibration and ringing syndromes.

    Directory of Open Access Journals (Sweden)

    Yu-Hsuan Lin

    Full Text Available BACKGROUND: Phantom vibration syndrome is a type of hallucination reported among mobile phone users in the general population. Another similar perception, phantom ringing syndrome, has not been previously described in the medical literature. METHODS: A prospective longitudinal study of 74 medical interns (46 males, 28 females; mean age, 24.8±1.2 years was conducted using repeated investigations of the prevalence and associated factors of phantom vibration and ringing. The accompanying symptoms of anxiety and depression were evaluated with the Beck Anxiety and Depression Inventories before the internship began, and again at the third, sixth, and twelfth internship months, and two weeks after the internship ended. RESULTS: The baseline prevalence of phantom vibration was 78.1%, which increased to 95.9% and 93.2% in the third and sixth internship months. The prevalence returned to 80.8% at the twelfth month and decreased to 50.0% 2 weeks after the internship ended. The baseline prevalence of phantom ringing was 27.4%, which increased to 84.9%, 87.7%, and 86.3% in the third, sixth, and twelfth internship months, respectively. This returned to 54.2% two weeks after the internship ended. The anxiety and depression scores also increased during the internship, and returned to baseline two weeks after the internship. There was no significant correlation between phantom vibration/ringing and symptoms of anxiety or depression. The incidence of both phantom vibration and ringing syndromes significantly increased during the internship, and subsequent recovery. CONCLUSION: This study suggests that phantom vibration and ringing might be entities that are independent of anxiety or depression during evaluation of stress-associated experiences during medical internships.

  19. [Psychotherapies for the Treatment of Phantom Limb Pain].

    Science.gov (United States)

    Cárdenas, Katherine; Aranda, Mariana

    The phantom limb pain has been described as a condition in which patients experience a feeling of itching, spasm or pain in a limb or body part that has been previously amputated. Such pain can be induced by a conflict between the representation of the visual and proprioceptive feedback of the previously healthy limb. The phantom limb pain occurs in at least 42 to 90% of amputees. Regular drug treatment of phantom limb pain is almost never effective. A systematic review of the literature was conducted in Medline and Cochrane using the MESH terms "phantom limb pain" and "psychotherapy", published in the last 10 years, in English and Spanish, finding 49 items. After reviewing the abstracts, 25 articles were excluded for not being related to the objective of the research. Additionally cross references of included articles and literature were reviewed. To describe the psychotherapies used in the management of phantom limb pain, their effectiveness and clinical application reported in the literature. The mechanisms underlying phantom limb pain were initially explained, as were the published studies on the usefulness of some psychotherapies such as mirror visual feedback and immersive virtual reality, visual imagery, desensitization and reprocessing eye movements and hypnosis. The phantom limb pain is a complex syndrome that requires pharmacological and psychotherapeutic intervention. The psychotherapies that have been used the most as adjuvants in the treatment of phantom limb pain are mirror visual feedback, desensitization and reprocessing eye movements, imagery and hypnosis. Studies with more representative samples, specifically randomized trials are required. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  20. Pulse wave imaging of normal and aneurysmal abdominal aortas in vivo.

    Science.gov (United States)

    Luo, Jianwen; Fujikura, Kana; Tyrie, Leslie S; Tilson, M David; Konofagou, Elisa E

    2009-04-01

    The abdominal aortic aneurysm (AAA) is a common vascular disease. The current clinical criterion for treating AAAs is an increased diameter above a critical value. However, the maximum diameter does not correlate well with aortic rupture, the main cause of death from AAA disease. AAA disease leads to changes in the aortic wall mechanical properties. The pulse-wave velocity (PWV) may indicate such a change. Because of limitations in temporal and spatial resolution, the widely used foot-to-foot method measures the global, instead of regional, PWV between two points at a certain distance in the circulation. However, mechanical properties are nonuniform along the normal and pathological (e.g., the AAA and atherosclerosis) arteries; thus, such changes are typically regional. Pulse-wave imaging (PWI) has been developed by our group to map the pulse-wave propagation along the abdominal aorta in mice in vivo. By using a retrospective electrocardiogram (ECG) gating technique, the radio-frequency (RF) signals over one cardiac cycle were obtained in murine aortas at the extremely high frame rate of 8 kHz and with a field-of-view (FOV) of 12 x 12 mm(2). The velocities of the aortic wall were estimated using an RF-based speckle tracking method. An Angiotensin II (AngII) infusion-based AAA model was used to simulate the human AAA case. Sequences of wall velocity images can noninvasively and quantitatively map the propagation of the pulse wave along the aortic wall. In the normal and sham aortas, the propagation of the pulse wave was relatively uniform along the wall, while in the AngII-treated aortas, the propagation was shown to be nonuniform. There was no significant difference ( p > 0.05) in the PWV between sham (4.67 +/- 1.15 m/s, n=5) and AngII-treated (4.34 +/- 1.48 m/s, n=17) aortas. The correlation coefficient of the linear regression was significantly higher ( p wave were lower and the pulse wave moved nonuniformly along the AngII-treated aorta ( p wave propagation

  1. Two-layer heterogeneous breast phantom for photoacoustic imaging

    Science.gov (United States)

    Jia, Congxian; Vogt, William C.; Wear, Keith A.; Pfefer, T. Joshua; Garra, Brian S.

    2017-10-01

    Photoacoustic tomography (PAT) is emerging as a potentially important aid for breast cancer detection. Well-validated tissue-simulating phantoms are needed for objective, quantitative, and physically realistic testing for system development. Prior reported PAT phantoms with homogenous structures do not incorporate the irregular layered structure of breast tissue. To assess the impact of this simplification, we design and construct two-layer breast phantoms incorporating vessel-simulating inclusions and realistic undulations at the fat/fibroglandular tissue interface. The phantoms are composed of custom poly(vinyl chloride) plastisol formulations mimicking the acoustic properties of two breast tissue types and tissue-relevant similar optical properties. Resulting PAT images demonstrate that in tissue with acoustic heterogeneity, lateral size of imaging targets is sensitive to the choice of sound speed in image reconstruction. The undulating boundary can further degrade a target's lateral size due to sound speed variation in tissue and refraction of sound waves at the interface. The extent of this degradation is also influenced by the geometric relationship between an absorber and the boundary. Results indicate that homogeneous phantom matrixes may underestimate the degradation of PAT image quality in breast tissue, whereas heterogeneous phantoms can provide more realistic testing through improved reproduction of spatial variations in physical properties.

  2. A software assistant for the design of realistic software phantoms

    Science.gov (United States)

    Rexilius, Jan; Konrad, Olaf; Peitgen, Heinz-Otto

    2008-03-01

    Segmentation and quantification of medical image data are difficult problems in image analysis. Especially, an accurate and robust assessment of quantitative parameters is a key issue in many fields, and can have a direct impact on diagnosis and treatment planning. To this end, physical and software phantom data sets have become an integral tool during the design, implementation, and optimization of new algorithms. Unfortunately, a common research resource has not been established until now for many applications. In this work we propose a software assistant for the development of realistic software phantoms. Our aim is an easy-to-use tool with an intuitive user interface. Furthermore, we provide a software for researchers including a common basis of reference data, which facilitates a standardized and objective validation of performance and limitations of own developments, as well as the comparison of different methods. The fundamental phantom design focuses on objects that can be incorporated into a given background. This can either be a homogeneous artificial background, or a volunteer or patient data set. For each phantom the exact ground truth of the investigated object is available, which provides us with an excellent tool for the generation of realistic data sets. Several experiments are carried out for a number of different applications including software phantoms of small, hyperintense brain lesions, as well as software phantoms of liver metastases.

  3. Liver phantom for quality control and training in nuclear medicine

    Science.gov (United States)

    Lima Ferreira, Fernanda Carla; Souza, Divanizia do Nascimento

    2011-10-01

    In nuclear medicine, liver scintigraphy aims to verify organ function based on the radionuclide concentration in the liver and bile flow and is also used to detect tumors. Therefore it is necessary to perform quality control tests in the gamma camera before running the exam to prevent false results. Quality control tests of the gamma camera should thus be performed before running the exam to prevent false results. Such tests generally use radioactive material inside phantoms for evaluation of gamma camera parameters in quality control procedures. Phantoms can also be useful for training doctors and technicians in nuclear medicine procedures. The phantom proposed here has artifacts that simulate nodules; it may take on different quantities, locations and sizes and it may also be mounted without the introduction of nodules. Thus, its images may show hot or cold nodules or no nodules. The phantom consists of acrylic plates hollowed out in the centre, with the geometry of an adult liver. Images for analyses of simulated liver scintigraphy were obtained with the detector device at 5 cm from the anterior surface of the phantom. These simulations showed that this object is suitable for quality control in nuclear medicine because it was possible to visualize artifacts larger than 7.9 mm using a 256×256 matrix and 1000 kcpm. The phantom constructed in this work will also be useful for training practitioners and technicians in order to prevent patients from repeat testing caused by error during examinations.

  4. Early Cellular Changes in the Ascending Aorta and Myocardium in a Swine Model of Metabolic Syndrome.

    Science.gov (United States)

    Saraf, Rabya; Huang, Thomas; Mahmood, Feroze; Owais, Khurram; Bardia, Amit; Khabbaz, Kamal R; Liu, David; Senthilnathan, Venkatachalam; Lassaletta, Antonio D; Sellke, Frank; Matyal, Robina

    2016-01-01

    Metabolic syndrome is associated with pathological remodeling of the heart and adjacent vessels. The early biochemical and cellular changes underlying the vascular damage are not fully understood. In this study, we sought to establish the nature, extent, and initial timeline of cytochemical derangements underlying reduced ventriculo-arterial compliance in a swine model of metabolic syndrome. Yorkshire swine (n = 8 per group) were fed a normal diet (ND) or a high-cholesterol (HCD) for 12 weeks. Myocardial function and blood flow was assessed before harvesting the heart. Immuno-blotting and immuno-histochemical staining were used to assess the cellular changes in the myocardium, ascending aorta and left anterior descending artery (LAD). There was significant increase in body mass index, blood glucose and mean arterial pressures (p = 0.002, p = 0.001 and p = 0.024 respectively) in HCD group. At the cellular level there was significant increase in anti-apoptotic factors p-Akt (p = 0.007 and p = 0.002) and Bcl-xL (p = 0.05 and p = 0.01) in the HCD aorta and myocardium, respectively. Pro-fibrotic markers TGF-β (p = 0.01), pSmad1/5 (p = 0.03) and MMP-9 (p = 0.005) were significantly increased in the HCD aorta. The levels of pro-apoptotic p38MAPK, Apaf-1 and cleaved Caspase3 were significantly increased in aorta of HCD (p = 0.03, p = 0.04 and p = 0.007 respectively). Similar changes in coronary arteries were not observed in either group. Functionally, the high cholesterol diet resulted in significant increase in ventricular end systolic pressure and-dp/dt (p = 0.05 and p = 0.007 respectively) in the HCD group. Preclinical metabolic syndrome initiates pro-apoptosis and pro-fibrosis pathways in the heart and ascending aorta, while sparing coronary arteries at this early stage of dietary modification.

  5. DOMINANCE OF CORONARY ARTERY DISEASE AMONG PATIENTS WITH ANEURYSM OF ABDOMINAL AORTA

    Directory of Open Access Journals (Sweden)

    Maja Zdravkovic

    2007-12-01

    Full Text Available Persons with aneurysm of the abdominal aorta have high prevalence of risk factors of cardiovascular disease. It cannot be stated with certainty whether these persons die in a large number due to the existence of risk factors or the genesis and complications of aneurysm itself. In patients with aneurysm of the abdominal aorta, there is a high correlation with the coronary artery disease; therefore, the aim of the study was to prove whether or not this is the case. The patients in preparation for the resection of the abdominal aorta aneurysm at the Institute of Cardiovascular Disease underwent the examination. The study included 377 examinees, of whom 341 males and 36 females, aged 45 to 83 years, during the three-year interval (from 2004 to 2006. The aim of the study was to determine the dominance of the coronary artery disease among the patients with aneurysm of the abdominal aorta. In the process of analyzing the data obtained from patients and medical evidence, it was found out that a large number of the abdominal aortic aneurysm patients were at the same time the coronary artery disease patients (55,2%; Hi=15,04; p80 kg was larger, as well as the percentage of patients with hypertension (89% and increased levels of cholesterol and triglycerides (67%. There was a great number of those with the inherited factor (40%. It has been proven that the risk factors for the development of coronary artery disease are in direct association with the risk factors for the abdominal aortic aneurysm. Also, there is a great predominance of the coronary artery disease among the patients with aneurysm of the abdominal aorta. The coronary artery disease is one of the main risk factors. If we managed to prevent the appearance of this disease or achieve the timely diagnosing of it and eventual curing, we would be able to decrease the development of the abdominal aortic aneurysm well as the consequences and further complications.

  6. 1,4-Anhydro-4-seleno-d-talitol (SeTal) protects endothelial function in the mouse aorta by scavenging superoxide radicals under conditions of acute oxidative stress

    DEFF Research Database (Denmark)

    Ng, Hooi Hooi; Leo, Chen Huei; O'Sullivan, Kelly

    2017-01-01

    Hyperglycaemia increases the generation of reactive oxidants in blood vessels and is a major cause of endothelial dysfunction. A water-soluble selenium-containing sugar (1,4-Anhydro-4-seleno-d-talitol, SeTal) has potent antioxidant activity in vitro and is a promising treatment to accelerate wound...... healing in diabetic mice. One possible mechanism of SeTal action is a direct effect on blood vessels. Therefore, we tested the hypothesis that SeTal prevents endothelial dysfunction by scavenging reactive oxidants in isolated mouse aorta under conditions of acute oxidative stress induced by hyperglycaemia...

  7. Motorized fusion guided prostate biopsy: phantom study

    Science.gov (United States)

    Seifabadi, Reza; Xu, Sheng; Aalamifar, Fereshteh; Pinto, Peter; Wood, Bradford J.

    2017-03-01

    Purpose: Fusion of Magnetic Resonance Imaging (MRI) with intraoperative real-time Ultrasound (US) during prostate biopsy has significantly improved the sensitivity of transrectal ultrasound (TRUS) guided cancer detection. Currently, sweeping of the TRUS probe to build a 3D volume as part of the fusion process and the TRUS probe manipulation for needle guidance are both done manually. A motorized, joystick controlled, probe holder was custom fabricated that can potentially reduce inter-operator variability, provide standardization of needle placement, improve repeatability and uniformity of needle placement, which may have impacts upon the learning curve after clinical deployment of this emerging approach. Method: a 2DOF motorized probe holder was designed to provide translation and rotation of a triplane TRUS end firing probe for prostate biopsy. The probe holder was joystick controlled and can assist manipulation of the probe during needle insertion as well as in acquiring a smoother US 2D to 3D sweep in which the 3D US volume for fusion is built. A commercial MRI-US fusion platform was used. Three targets were specified on MR image of a commercial prostate phantom. After performing the registration, two operators performed targeting, once manually and once with the assistance of the motorized probe holder. They repeated these tasks 5 times resulting in a total of 30 targeting events. Time of completion and mechanical error i.e. distance of the target from the needle trajectory in the software user interface were measured. Repeatability in reaching a given target in a systematic and consistent way was measured using a scatter plot showing all targets in the US coordinate system. Pearson product-moment correlation coefficient (PPMCC) was used to demonstrate the probe steadiness during targeting. Results: the completion time was 25+/-17 sec, 25+/-24 sec, and 27+/-15 sec for free hand and 24+/-10 sec, 22.5+/-10 sec, and 37+/-10 sec for motorized insertion, for target

  8. In Vitro demonstration of an SpO2-Camera

    NARCIS (Netherlands)

    Wieringa, F.P.; Mastik, F.; Boks, R.H.; Visscher, A.; Bogers, A.; Steen, A.F.W. van der

    2007-01-01

    Feasibility of pulse oxigraphy is examined using an in- vitro phantom, perfused with human blood by a heart- lung machine. 29 different oxygen saturation levels, measured with our experimental camera and a clinical pulse oximeter, were matched against laboratory blood gas analysis. Discrete transfer

  9. Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xueqian [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen, The Netherlands and Center for Medical Imaging – North East Netherlands, Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Greuter, Marcel J. W. [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Groen, Jaap M. [Department of Radiology, Zaans Medical Center, 1500EE Zaandam (Netherlands); Bock, Geertruida H. de [Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Oudkerk, Matthijs [Center for Medical Imaging – North East Netherlands, Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands); Jong, Pim A. de [Department of Radiology, University Medical Center Utrecht, University of Utrecht, 3584CX Utrecht (Netherlands); Vliegenthart, Rozemarijn [Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700RB Groningen, The Netherlands and Center for Medical Imaging – North East Netherlands, Department of Radiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9700RB Groningen (Netherlands)

    2013-08-15

    Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontriggered thoracic CT and ECG-triggered cardiac CT.Methods: Three artificial coronary arteries containing calcifications of different densities (high, medium, and low), and sizes (large, medium, and small), were studied in a moving cardiac phantom. Two 64-detector CT systems were used. The phantom moved at 0–90 mm/s in nontriggered low-dose CT as index test, and at 0–30 mm/s in ECG-triggered CT as reference. Differences in calcium scores between nontriggered and ECG-triggered CT were analyzed by t-test and 95% confidence interval. The sensitivity to detect calcification was calculated as the percentage of positive calcium scores.Results: Overall, calcium scores in nontriggered CT were not significantly different to those in ECG-triggered CT (p > 0.05). Calcium scores in nontriggered CT were within the 95% confidence interval of calcium scores in ECG-triggered CT, except predominantly at higher velocities (≥50 mm/s) for the high-density and large-size calcifications. The sensitivity for a nonzero calcium score was 100% for large calcifications, but 46%± 11% for small calcifications in nontriggered CT.Conclusions: When performing multiple measurements, good agreement in positive calcium scores is found between nontriggered thoracic and ECG-triggered cardiac CT. Agreement decreases with increasing coronary velocity. From this phantom study, it can be concluded that a high calcium score can be detected by nontriggered CT, and thus, that nontriggered CT likely can identify individuals at high risk of cardiovascular disease. On the other hand, a zero calcium score in nontriggered CT does not reliably exclude coronary calcification.

  10. [Mirror, mirror of the wall: mirror therapy in the treatment of phantom limbs and phantom limb pain].

    Science.gov (United States)

    Casale, Roberto; Furnari, Anna; Lamberti, Raul Coelho; Kouloulas, Efthimios; Hagenberg, Annegret; Mallik, Maryam

    2015-01-01

    Phantom limb and phantom limb pain control are pivotal points in the sequence of intervention to bring the amputee to functional autonomy. The alterations of perception and sensation, the pain of the residual limb and the phantom limb are therefore aspects of amputation that should be taken into account in the "prise en charge" of these patients. Within the more advanced physical therapies to control phantom and phantom limb pain there is the use of mirrors (mirror therapy). This article willfocus on its use and on the possible side effects induced by the lack of patient selection and a conflict of body schema restoration through mirror therapy with concurrent prosthetic training and trauma acceptance. Advice on the need to select patients before treatment decisions, with regard to their psychological as well as clinical profile (including time since amputation and clinical setting), and the need to be aware of the possible adverse effects matching different and somehow conflicting therapeutic approaches, are put forward. Thus a coordinated sequence of diagnostic, prognostic and therapeutic procedures carried out by an interdisciplinary rehabilitation team that works globally on all patients' problems is fundamental in the management of amputees and phantom limb pain. Further studies and the development of a multidisciplinary network to study this and other applications of mirror therapy are needed.

  11. Energy Efficient Resource Allocation for Phantom Cellular Networks

    KAUST Repository

    Abdelhady, Amr

    2016-04-01

    Multi-tier heterogeneous networks have become an essential constituent for next generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-tier network architecture known as phantom cellular networks. The optimization framework includes both EE and SE. First, we consider sparsely deployed cells experiencing negligible interference and assume perfect channel state information (CSI). For this setting, we propose an algorithm that finds the SE and EE resource allocation strategies. Then, we compare the performance of both design strategies versus number of users, and phantom cells share of the total available resource units (RUs). We aim to investigate the effect of some system parameters to achieve improved SE performance at a non-significant loss in EE performance, or vice versa. It is found that increasing phantom cells share of RUs decreases the SE performance loss due to EE optimization when compared with the optimized SE performance. Second, we consider the densely deployed phantom cellular networks and model the EE optimization problem having into consideration the inevitable interference and imperfect channel estimation. To this end, we propose three resource allocation strategies aiming at optimizing the EE performance metric of this network. Furthermore, we investigate the effect of changing some of the system parameters on the performance of the proposed strategies, such as phantom cells share of RUs, number of deployed phantom cells within a macro cell coverage, number of pilots and the maximum power available for transmission by the phantom cells BSs. It is found that increasing the number of pilots deteriorates the EE performance of the whole setup, while increasing maximum power available for phantom cells transmissions reduces the EE of the whole setup in a

  12. Follow-up of aortic dissection: contribution of MR angiography for evaluation of the abdominal aorta and its branches

    Energy Technology Data Exchange (ETDEWEB)

    Bogaert, J. [Department of Radiology, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium); Meyns, B. [Department of Cardiac Surgery, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium); Rademakers, F.E. [Department of Internal Medicine, Division of Cardiology, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium); Bosmans, H. [Department of Radiology, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium); Verschakelen, J. [Department of Radiology, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium); Flameng, W. [Department of Cardiac Surgery, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium); Marchal, G. [Department of Radiology, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium); Baert, A.L. [Department of Radiology, Catholic University Hospitals, Herestraat 49, B-3000 Leuven (Belgium)

    1997-06-01

    Spin-echo MR is an established method to evaluate thoracic aortic dissections, but is not well suited to study the abdominal aorta. In this study we evaluated whether MR angiography could provide a complete examination of the abdominal aorta. In 28 patients (40 MR studies) with suspected (n = 6) or known (n = 34) aortic dissection, MR studies were performed. Thoracic aorta was evaluated with spin-echo and gradient-recalled-echo MR imaging. Axial two-dimensional time-of-flight MR angiography with thin overlapping slices was used to study the abdominal aorta. Intermediate and high signal intensity on MR angiography was interpreted as patent flow, and low signal was interpreted as thrombus. The presence of an intima flap and the re-entry site could be depicted in all MR studies. Thrombus in the false channel was seen in 8 studies. The origin of the abdominal visceral branches and their relation to the false-true channel could be depicted, except in 4 of 80 renal arteries studied. Extension of the dissection into the coeliac trunk was seen in 2 and in the superior mesenteric artery in 10 studies. Dilatation of the suprarenal abdominal aorta was seen in 20 studies, and of the infrarenal aorta in 9 studies. MR angiography provides valuable information about the abdominal aorta and its branches in patients with aortic dissection. This makes MR imaging appealing as the preferred imaging modality for the diagnosis and follow-up of aortic dissection. (orig.). With 6 figs., 6 tabs.

  13. Ultra-sonografia da aorta abdominal e de seus ramos em cães Ultrasonography of abdominal aorta and its branches in dogs

    Directory of Open Access Journals (Sweden)

    Lilian Kamikawa

    2007-04-01

    Full Text Available O ultra-som bidimensional e o ultra-som Doppler foram utilizados para avaliar a biometria e a hemodinâmica da aorta abdominal e artérias ilíacas externas de 131cães clinicamente normais. Os resultados da avaliação biométrica da aorta abdominal indicaram um diâmetro médio de 0,80cm para o seu segmento diafragmático (AOD; 0,74cm para o seu segmento caudal às artérias renais (AOR e 0,69cm para o segmento cranial à sua bifurcação (AOT. A artéria ilíaca externa direita (AIED apresentou o diâmetro médio de 0,42cm e a artéria ilíaca externa esquerda (AIEE o diâmetro médio de 0,39. O estudo hemodinâmico da aorta abdominal apresentou velocidade de pico sistólico médio de 104,00cm/s para AOR; 99,61cm/s para AOT; 85,47cm/s para AIED e 99,51cm/s para AIEE. Verificaram-se correlações de diferentes intensidades entre os diâmetros vasculares em diferentes pontos de tomadas e os fatores biométricos corpóreos (CRL. Correlações baixas foram observadas quando esses diâmetros foram confrontados com a idade.A duplex ultrasound system incorporating a pulsed wave Doppler ultrasound probe with conventional B-mode real-time imaging was used to evaluate the biometric and the hemodynamic of abdominal aorta and external iliac arteries of a hundred and thirty one normal dogs. Results of biometrics of abdominal aorta, presented a mean diameter of 0.80cm in its diaphragmatic segment (AOD; 0.74cm in its segment caudal to the renal arteries (AOR and 0.69cm in the segment cranial to its termination (AOT. The right-external-iliac artery (AIED presented a mean diameter of 0.42cm and the left-external iliac artery (AIEE a mean diameter of 0.39cm. The hemodynamic study of the abdominal aorta presented a medium systolic peak velocity to AOR of 104cm per sec.; to AOT of 99.61cm per sec.; to AIED of 85.47cm per sec. and to AIEE of 99.51cm per sec. Correlations of different intensities between the vascular diameters have been verified between the

  14. Reconstrução da aorta com conduto de pericárdio bovino corrugado

    Directory of Open Access Journals (Sweden)

    Claudio A. Salles

    1998-04-01

    Full Text Available No período de outubro de 1989 a maio de 1997, 40 pacientes portadores de dissecção aórtica, aneurisma da aorta, coarctação da aorta ou doença oclusiva aorto-ilíaca foram submetidos a reconstrução da aorta utilizando-se conduto de pericárdio bovino corrugado processado em glutaraldeído. A reconstrução total da aorta ascendente com substituição da valva aórtica e reimplante das artérias coronárias foi realizada em 9 pacientes, a simples substituição da aorta ascendente em 6, aorta torácica descendente em 2, arco aórtico em 1, aorta toracoabdominal em 1 e a aorta abdominal foi reconstruída em 21, incluindo pacientes submetidos a reconstrução aorto-ilíaca ou aorto-femoral. A mortalidade hospitalar foi de 8 (20% pacientes e as causas de óbito foram baixo débito cardíaco, recidiva da dissecção aórtica, falência de múltiplos órgãos e sangramento. O seguimento total foi de 128,4 pacientes-anos, com um seguimento médio de 4 anos por paciente. Complicações tardias relacionadas ao conduto vascular foram observadas em 4 pacientes, incluindo obstrução de um dos ramos do tubo bifurcado utilizado para reconstrução aorto-femoral e infecção em 3, resultando em degeneração secundária do conduto e formação de pseudo-aneurisma. Os 4 pacientes foram submetidos a reoperações, correspondendo a uma incidência de 3,1% ± 1,6% por paciente/ano. Ocorreram 5 óbitos tardios e as causas foram morte súbita, doença coronariana, pneumonia, septicemia e complicações metabólicas resultantes de diabetes e insuficiência renal crônica, correspondendo a uma incidência de 3,9% ± 1,7% por paciente/ano. A sobrevida atuarial em 9 anos foi 61,5% ± 9,2%, incluindo a mortalidade cirúrgica e a sobrevida atuarial livre de degeneração tissular estrutural primária do conduto biológico foi de 100%. O corrugamento do pericárdio, resultante da incorporação do princípio crimping utilizado nas próteses vasculares sint

  15. WE-D-303-00: Computational Phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, John [Duke University Medical Center, Durham, NC (United States); Brigham and Women’s Hospital and Dana-Farber Cancer Institute, Boston, MA (United States)

    2015-06-15

    Modern medical physics deals with complex problems such as 4D radiation therapy and imaging quality optimization. Such problems involve a large number of radiological parameters, and anatomical and physiological breathing patterns. A major challenge is how to develop, test, evaluate and compare various new imaging and treatment techniques, which often involves testing over a large range of radiological parameters as well as varying patient anatomies and motions. It would be extremely challenging, if not impossible, both ethically and practically, to test every combination of parameters and every task on every type of patient under clinical conditions. Computer-based simulation using computational phantoms offers a practical technique with which to evaluate, optimize, and compare imaging technologies and methods. Within simulation, the computerized phantom provides a virtual model of the patient’s anatomy and physiology. Imaging data can be generated from it as if it was a live patient using accurate models of the physics of the imaging and treatment process. With sophisticated simulation algorithms, it is possible to perform virtual experiments entirely on the computer. By serving as virtual patients, computational phantoms hold great promise in solving some of the most complex problems in modern medical physics. In this proposed symposium, we will present the history and recent developments of computational phantom models, share experiences in their application to advanced imaging and radiation applications, and discuss their promises and limitations. Learning Objectives: Understand the need and requirements of computational phantoms in medical physics research Discuss the developments and applications of computational phantoms Know the promises and limitations of computational phantoms in solving complex problems.

  16. CREATION OF FEMALE COMPUTATIONAL PHANTOMS FOR CALIBRATION OF LUNG COUNTERS.

    Science.gov (United States)

    Lombardo, Pasquale Alessandro; Lebacq, Anne Laure; Vanhavere, Filip

    2016-09-01

    Plutonium isotopes are of high concern because they lead to high doses. In case of contamination, the activity burden inside the lungs should be assessed accurately. Many studies showed that the presence of breasts has a substantial influence on lung counting efficiencies. Currently, the calibration of most lung counting systems is done by means of physical phantoms representing only male chests. A set of female computational phantoms has been developed in order to provide gender-specific efficiency calibrations for the (241)Am gamma emission (59.54 keV). The phantoms were created starting from a library of female chest phantoms provided by Institut de radioprotection et de sûreté nucléaire (IRSN) (Farah, J. Amélioration des mesures anthroporadiamétriques personnalisées assistées par calcul Monte Carlo: optimisation des temps de calculs et méthodologie de mesure pour l'établissement de la répartition d'activite. PhD Thesis, 2011). While the IRSN phantoms represent a supine measurement position, the SCK•CEN lung counter set-up requires the persons to be sitting in a chair. Using open-source software, the breast shapes of the original phantoms have been recreated to simulate the drooping of breasts in vertical sitting position. A Monte Carlo approach was chosen for calculating calibration coefficients for female lung counting. The results obtained with MCNPx 2.7 simulations showed a significant decrease in the detection efficiency. For bigger bust and breast sizes, the detection efficiency showed to be up to 10 times lower than the ones measured with the Livermore male torso phantom. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Development of breast phantom for quality assessment of mammographic images

    Energy Technology Data Exchange (ETDEWEB)

    Arvelos, Jeniffer Miranda; Flores, Mabel Bustos; Amaral, Fernando; Rio, Margarita Chevalier del; Mourao, Arnaldo Prata, E-mail: jenifferarvelos00@gmail.com [Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Centro de Engenharia Biomedica; Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Universidad Complutense de Madrid (UCM), Madrid (Spain). Faculdad de Medicina. Departmento de Radiologia

    2017-11-01

    Diagnosis of breast cancer in young women may be impaired by the tissue composition of breast in this age group, as fibroglandular tissue is present in greater amount in young women and it has higher density than fibrous and fatty tissues which predominate in women older than 40 years old. The higher density of breast tissue makes it difficult to identify nodules in two-dimensional techniques, due to the overlapping of dense layers. Breast phantoms are used in evaluation and quality control of clinical images, and therefore, it is important to develop non-homogeneous phantoms that may better simulate a real breast. Grouped microcalcifications are often the earliest changes associated with malignant neoplasm of breast. In this work, a phantom was developed in the form of a compressed breast using acrylic resin blend. The resin blend used to fulfill the interior of the phantom has similar mammographic density to the one in fibroglandular tissue, representing a dense breast. The lesions were made of acrylic resin blend and calcium compounds that might simulate breast abnormalities, representing nodules, macrocalcifications and microcalcifications of different dimensions and densities. They were distributed into the ma-terial representing fibroglandular tissue. The developed phantom has a thickness of 1 cm, and it may be matched with other plates to represent a dense breast of thickness between 5 and 6 cm. The main goal of the project is to evaluate the sensitivity of detection of these calcifications in relation to their density and location in the breast in two-dimensional images generated in mammography equipment. Mammographic images allow the visualization of the changes implemented in the phantom. The developed phantom may be used in evaluation of diagnostic images generated through two-dimensional and three-dimensional images. (author)

  18. Characterization of transverse isotropy in compressed tissue-mimicking phantoms.

    Science.gov (United States)

    Urban, Matthew W; Lopera, Manuela; Aristizabal, Sara; Amador, Carolina; Nenadic, Ivan; Kinnick, Randall R; Weston, Alexander D; Qiang, Bo; Zhang, Xiaoming; Greenleaf, James F

    2015-06-01

    Tissues such as skeletal muscle and kidneys have well-defined structure that affects the measurements of mechanical properties. As an approach to characterize the material properties of these tissues, different groups have assumed that they are transversely isotropic (TI) and measure the shear wave velocity as it varies with angle with respect to the structural architecture of the organ. To refine measurements in these organs, it is desirable to have tissue-mimicking phantoms that exhibit similar anisotropic characteristics. Some approaches involve embedding fibers into a material matrix. However, if a homogeneous solid is under compression due to a static stress, an acoustoelastic effect can manifest that makes the measured wave velocities change with the compression stress. We propose to exploit this characteristic to demonstrate that stressed tissue mimicking phantoms can be characterized as a TI material. We tested six phantoms made with different concentrations of gelatin and agar. Stress was applied by the weight of a water container centered on top of a plate on top of the phantom. A linear array transducer and a V-1 Verasonics system were used to induce and measure shear waves in the phantoms. The shear wave motion was measured using a compound plane wave imaging technique. Autocorrelation was applied to the received in-phase/quadrature data. The shear wave velocity, c, was estimated using a Radon transform method. The transducer was mounted on a rotating stage so measurements were made every 10° over a range of 0° to 360°, where the stress is applied along 0° to 180° direction. The shear moduli were estimated. A TI model was fit to the data and the fractional anisotropy was evaluated. This approach can be used to explore many configurations of transverse isotropy with the same phantom, simply by applying stress to the tissue-mimicking phantom.

  19. Characterization of Transverse Isotropy in Compressed Tissue Mimicking Phantoms

    Science.gov (United States)

    Urban, Matthew W.; Lopera, Manuela; Aristizabal, Sara; Amador, Carolina; Nenadic, Ivan; Kinnick, Randall R.; Weston, Alexander D.; Qiang, Bo; Zhang, Xiaoming; Greenleaf, James F.

    2015-01-01

    Tissues such as skeletal muscle and kidneys have well-defined structure that affects the measurements of mechanical properties. As an approach to characterize the material properties of these tissues, different groups have assumed that they are transversely isotropic (TI) and measure the shear wave velocity as it varies with angle with respect to the structural architecture of the organ. To refine measurements in these organs, it is desirable to have tissue mimicking phantoms that exhibit similar anisotropic characteristics. Some approaches involve embedding fibers into a material matrix. However, if a homogeneous solid is under compression due to a static stress, an acoustoelastic effect can manifest which makes the measured wave velocities change with the compression stress. We propose to exploit this characteristic to demonstrate that stressed tissue mimicking phantoms can be characterized as a TI material. We tested six phantoms made with different concentrations of gelatin and agar. Stress was applied by the weight of a water container centered on top of a plate on top of the phantom. A linear array transducer and a V-1 Verasonics system were used to induce and measure shear waves in the phantoms. The shear wave motion was measured using a compound plane wave imaging technique. Autocorrelation was applied to the received in-phase/quadrature data. The shear wave velocity, c, was estimated using a Radon transform method. The transducer was mounted on a rotating stage so measurements were made every 10° over a range of 0–360°, where the stress is applied along 0–180° direction. The shear moduli were estimated. A TI model was fit to the data and the fractional anisotropy was evaluated. This approach can be used to explore many configurations of transverse isotropy with the same phantom, simply by applying stress to the tissue mimicking phantom. PMID:26067038

  20. Fuzzy classification of phantom parent groups in an animal model

    Directory of Open Access Journals (Sweden)

    Fikse Freddy

    2009-09-01

    Full Text Available Abstract Background Genetic evaluation models often include genetic groups to account for unequal genetic level of animals with unknown parentage. The definition of phantom parent groups usually includes a time component (e.g. years. Combining several time periods to ensure sufficiently large groups may create problems since all phantom parents in a group are considered contemporaries. Methods To avoid the downside of such distinct classification, a fuzzy logic approach is suggested. A phantom parent can be assigned to several genetic groups, with proportions between zero and one that sum to one. Rules were presented for assigning coefficients to the inverse of the relationship matrix for fuzzy-classified genetic groups. This approach was illustrated with simulated data from ten generations of mass selection. Observations and pedigree records were randomly deleted. Phantom parent groups were defined on the basis of gender and generation number. In one scenario, uncertainty about generation of birth was simulated for some animals with unknown parents. In the distinct classification, one of the two possible generations of birth was randomly chosen to assign phantom parents to genetic groups for animals with simulated uncertainty, whereas the phantom parents were assigned to both possible genetic groups in the fuzzy classification. Results The empirical prediction error variance (PEV was somewhat lower for fuzzy-classified genetic groups. The ranking of animals with unknown parents was more correct and less variable across replicates in comparison with distinct genetic groups. In another scenario, each phantom parent was assigned to three groups, one pertaining to its gender, and two pertaining to the first and last generation, with proportion depending on the (true generation of birth. Due to the lower number of groups, the empirical PEV of breeding values was smaller when genetic groups were fuzzy-classified. Conclusion Fuzzy

  1. Skin Dosimetry in Breast Teletherapy on a Phantom Anthropomorphic and Anthropometric Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Batista Nogueira, Luciana [Anatomy and Imaging Department, Federal University of Minas Gerais, Belo Horizonte (Brazil); Lemos Silva, Hugo Leonardo [Santa Casa Hospital, Belo Horizonte (Brazil); Donato da Silva, Sabrina; Passos Ribeiro Campos, Tarcisio [Nuclear Engineering Department, Federal University of Minas Gerais, Belo Horizonte (Brazil)

    2015-07-01

    This paper addresses the breast teletherapy dosimetry. The goal is to evaluate and compare absorbed doses in equivalent skin tissue, TE-skin, of an anthropomorphic and anthropometric breast phantom submitted to breast radiotherapy. The methodology involved the reproduction of a set of tomographic images of the phantom; the elaboration of conformational radiotherapy planning in the SOMAVISION and CadPlan (TPS) software; and the synthetic breast irradiation by parallel opposed fields in 3D conformal teletherapy at 6 MV linear accelerator Clinac-2100 C from VARIAN with prescribed dose (PD) of 180 cGy to the target volume (PTV), referent to the glandular tissue. Radiochromic films EBT2 were selected as dosimeters. Two independent calibration processes of films with solid water Gammex 457 plates and water filled box were produced. Curves of optical density (OD) versus absorbed dose were produced. Dosimeters were positioned in the external region of the breast phantom in contact with TE-skin, area of 4.0 cm{sup 2} each. The irradiation process was prepared in duplicate to check the reproducibility of the technique. The radiochromic films were scanned and their response in RGB (Red, Green, Blue) analyzed by the ImageJ software. The optical density was obtained and converted to dose based on the calibration curves. Thus, the spatial dose distribution in the skin was reproduced. The absorbed doses measured on the radiochromic films in TE-skin showed values between upper and lower quadrants at 9 o'clock in the range of 54% of PD, between the upper and lower quadrants 3 o'clock in the range of 72% and 6 o'clock at the lower quadrant in the range of 68 % of PD. The values are ±64% (p <0.05) according to the TPS. It is concluded that the depth dose measured in solid water plates or water box reproduce equivalent dose values for both calibration processes of the radiochromic films. It was observed that the skin received doses ranging from 50% to 78% of the

  2. Cartesian positioning system for localization of blast and ballistic fragments: a phantom-based pilot study.

    Science.gov (United States)

    Folio, Les; Fischer, Tatjana; Shogan, Paul J; Frew, Michael; Bunger, Rolf; Provenzale, James M

    2011-11-01

    Our purpose was to demonstrate the consistency of radiologists' three-dimensional measurements of simulated blast fragment locations in vitro in an effort to objectively localize retained fragments and wound paths. We designed a phantom consisting of 10 nail heads (simulating blast fragments) glued to wooden pegs that were randomly situated at distances from a reference point within a plastic tub. The x, y, and z coordinates of simulated fragments were recorded in Cartesian 3-space relative to the reference point. Computed tomography images of the phantom were acquired. Differences in x, y, and z positions as determined by three observers were summed for each fragment. Agreement between recordings of coordinates across readers was assessed using the intraclass correlation coefficient. Summed differences in coordinate positions as determined by readers ranged between 0.00 and 1.204 cm (mean: 0.732 cm). Across readers, the intraclass correlation coefficient for each dimension was >0.99. We found excellent agreement among readers with minimal discrepancy of measured locations of simulated fragments. Our results provide a foundation for trajectory analysis necessary to lead to automated organ damage reporting for immediate assessment in the emergency department and for forensic investigation and long-term epidemiological analysis.

  3. Computed Tomography Angiography With High Flow Rates: An In Vitro and In Vivo Feasibility Study.

    Science.gov (United States)

    Mihl, Casper; Kok, Madeleine; Wildberger, Joachim E; Turek, Jakub; Muehlenbruch, Georg; Das, Marco

    2015-07-01

    The aims of this study were to test high-flow application of contrast media (CM) using novel high-flow needles and to assess injection- and flow-related parameters in a circulation phantom and in an in vivo population. A circulation phantom simulating physiological parameters was used. Preheated CM (300 mg/mL) was injected at flow rates varying between 5 and 15 mL/s through a novel 18-gauge high-flow intravenous injection needle. In addition, feasibility of these high-flow needles was tested with administration of flow rates of 9 mL/s in 20 patients referred for pre-transcatheter aortic valve implantation assessment. Injection parameters (eg, peak pressures, peak flow rates) in both phantom and in vivo setup were continuously monitored by a data acquisition program. Attenuation at predefined levels of the aorta (eg, aortic root to common femoral arteries) was measured in all patients to determine clinical applicability. In the phantom setup, injection rates up to 15 mL/s were feasible. An enhancement plateau was reached at 11 mL/s (464 [20] HU). In patients, no pressure- or flow-related complications (eg, extravasation) were recorded (mean [SD] peak pressure, 154 [8] psi; mean [SD] peak flow rate, 9.2 [0.1 mL/s; range, 9.1-9.6]). Diagnostic attenuation values were reached at all predefined levels of the aorta (330.8 [113.1] HU to 622.9 [81.5] HU). These results indicate that injections with 9 mL/s using high-flow injection needles are safe. The pressure limit of 325 psi was not reached, and the injections resulted in diagnostic attenuation values. Using this dedicated needle, high flow rates should not be considered a drawback for CM application in routine CT angiography examinations.

  4. Disentangling motor execution from motor imagery with the phantom limb.

    Science.gov (United States)

    Raffin, Estelle; Mattout, Jérémie; Reilly, Karen T; Giraux, Pascal

    2012-02-01

    Amputees can move their phantom limb at will. These 'movements without movements' have generally been considered as motor imagery rather than motor execution, but amputees can in fact perform both executed and imagined movements with their phantom and they report distinct perceptions during each task. Behavioural evidence for this dual ability comes from the fact that executed movements are associated with stump muscle contractions whereas imagined movements are not, and that phantom executed movements are slower than intact hand executed movements whereas the speed of imagined movements is identical for both hands. Since neither execution nor imagination produces any visible movement, we hypothesized that the perceptual difference between these two motor tasks relies on the activation of distinct cerebral networks. Using functional magnetic resonance imaging and changes in functional connectivity (dynamic causal modelling), we examined the activity associated with imagined and executed movements of the intact and phantom hands of 14 upper-limb amputees. Distinct but partially overlapping cerebral networks were active during both executed and imagined phantom limb movements (both performed at the same speed). A region of interest analysis revealed a 'switch' between execution and imagination; during execution there was more activity in the primary somatosensory cortex, the primary motor cortex and the anterior lobe of the cerebellum, while during imagination there was more activity in the parietal and occipital lobes, and the posterior lobe of the cerebellum. In overlapping areas, task-related differences were detected in the location of activation peaks. The dynamic causal modelling analysis further confirmed the presence of a clear neurophysiological distinction between imagination and execution, as motor imagery and motor execution had opposite effects on the supplementary motor area-primary motor cortex network. This is the first imaging evidence that the

  5. In vitro and in vivo comparison of a tailored magnetic particle imaging blood pool tracer with Resovist

    Science.gov (United States)

    Kaul, Michael Gerhard; Mummert, Tobias; Jung, Caroline; Salamon, Johannes; Khandhar, Amit P.; Ferguson, R. Matthew; Kemp, Scott J.; Ittrich, Harald; Krishnan, Kannan M.; Adam, Gerhard; Knopp, Tobias

    2017-05-01

    Optimizing tracers for individual imaging techniques is an active field of research. The purpose of this study was to perform in vitro and in vivo magnetic particle imaging (MPI) measurements using a new monodisperse and size-optimized tracer, LS-008, and to compare it with the performance of Resovist, the standard MPI tracer. Magnetic particle spectroscopy (MPS) and in vitro MPI measurements were performed in concerns of concentration and amount of tracer in a phantom. In vivo studies were carried out in healthy FVB mice. The first group (n  =  3) received 60 µl LS-008 (87 mM) and the second (n  =  3) diluted Resovist of the same concentration and volume. Tracer injections were performed with a syringe pump during a dynamic MPI scan. For anatomic referencing MRI was applied beforehand of the MPI measurements. Summing up MPS examinations and in vitro MPI experiments, LS-008 showed better sensitivity and spatial resolution than Resovist. In vivo both tracers can visualize the propagation of the bolus through the inferior vena cava. MPI with LS-008 did show less temporal fluctuation artifacts and the pulsation of blood due to respiratory and cardiac cycle was detectable. With LS-008 the aorta was distinguishable from the caval vein while with Resovist this failed. A liver vessel and a vessel structure leading cranially could only be observed with LS-008 and not with Resovist. Beside these structural advantages both tracers showed very different blood half-life. For LS-008 we found 88 min. Resovist did show a fast liver accumulation and a half-life of 13 min. Only with LS-008 the perfusion fraction in liver and kidney was measureable. MPI for angiography can be significantly improved by applying more effective tracers. LS-008 shows a clear improvement concerning the delineation while resolving a larger number of vessels in comparison to Resovist. Therefore, in aspects of quality and quantity LS-008 is clearly favorable for angiographic and

  6. "Pulling telescoped phantoms out of the stump": manipulating the perceived position of phantom limbs using a full-body illusion.

    Science.gov (United States)

    Schmalzl, Laura; Thomke, Erik; Ragnö, Christina; Nilseryd, Maria; Stockselius, Anita; Ehrsson, H Henrik

    2011-01-01

    Most amputees experience phantom limbs, or the sensation that their amputated limb is still attached to the body. Phantom limbs can be perceived in the location previously occupied by the intact limb, or they can gradually retract inside the stump, a phenomenon referred to as "telescoping".  Telescoping is relevant from a clinical point of view, as it tends to be related to increased levels of phantom pain. In the current study we demonstrate how a full-body illusion can be used to temporarily revoke telescoping sensations in upper limb amputees. During this illusion participants view the body of a mannequin from a first person perspective while being subjected to synchronized visuo-tactile stimulation through stroking, which makes them experience the mannequin's body as their own. In Experiment 1 we used an intact mannequin, and showed that amputees can experience ownership of an intact body as well as referral of touch from both hands of the mannequin. In Experiment 2 and 3 we used an amputated mannequin, and demonstrated that depending on the spatial location of the strokes applied to the mannequin, participants experienced their phantom hand to either remain telescoped, or to actually be located below the stump. The effects were supported by subjective data from questionnaires, as well as verbal reports of the perceived location of the phantom hand in a visual judgment task. These findings are of particular interest, as they show that the temporary revoking of telescoping sensations does not necessarily have to involve the visualization of an intact hand or illusory movement of the phantom (as in the rubber hand illusion or mirror visual feedback therapy), but that it can also be obtained through mere referral of touch from the stump to the spatial location corresponding to that previously occupied by the intact hand. Moreover, our study also provides preliminary evidence for the fact that these manipulations can have an effect on phantom pain sensations.

  7. Pulling telescoped phantoms out of the stump: Manipulating the perceived position of phantom limbs using a full-body illusion

    Directory of Open Access Journals (Sweden)

    Laura eSchmalzl

    2011-11-01

    Full Text Available Most amputees experience phantom limbs, or the sensation that their amputated limb is still attached to the body. Phantom limbs can be perceived in the location previously occupied by the intact limb, or they can gradually retract inside the stump, a phenomenon referred to as telescoping. Telescoping is relevant from a clinical point of view, as it tends to be related to increased levels of phantom pain. In the current study we demonstrate how a full-body illusion can be used to temporarily revoke telescoping sensations in upper limb amputees. During this illusion participants view the body of a mannequin from a first person perspective while being subjected to synchronized visuo-tactile stimulation through stroking, which makes them experience the mannequin’s body as their own. In Experiment 1 we used an intact mannequin, and showed that amputees can experience ownership of an intact body as well as referral of touch from both hands of the mannequin. In Experiment 2 and 3 we used an amputated mannequin, and demonstrated that depending on the spatial location of the strokes applied to the mannequin, participants experienced their phantom hand to either remain telescoped, or to actually be located below the stump. The effects were supported by subjective data from questionnaires, as well as verbal reports of the perceived location of the phantom hand in a visual judgment task. These findings are of particular interest, as they show that the temporary revoking of telescoping sensations does not necessarily have to involve the visualization of an intact hand or illusory movement of the phantom (as in the rubber hand illusion or mirror visual feedback therapy, but that it can also be obtained through mere referral of touch from the stump to the spatial location corresponding to that previously occupied by the intact hand. Moreover, our study also provides preliminary evidence for the fact that these manipulations can have an effect on phantom pain

  8. Phantom limb pain: a report of two cases.

    Science.gov (United States)

    Töpfner, S; Wiech, K; Kiefer, R T; Unertl, K; Birbaumer, N

    2001-01-01

    The efficacy of pre-emptive analgesia for phantom limb pain is still unclear. It is generally accepted that pre hyphen;amputation pain increases the incidence of phantom and stump pain, even if pre-emptive analgesia is performed before and during surgery and in the postoperative period. Two cases of traumatic upper limb amputations are described here with no pre-existing pain. Both received similar antinociceptive treatment by continuous block of the brachial plexus through infusion of ropivacaine 0.375% at 5 ml/h for 10 days. Treatment of case 1 was initiated immediately after surgery; however, this amputee developed intensive phantom limb pain which persisted at 6 months. Early use of the prosthesis after surgery was not possible for this patient. The intensity of phantom limb pain in case 2 decreased significantly after 6 months, even though brachial plexus blockade was not started until 5 weeks post-trauma. This patient used a functional prosthesis intensively beginning early after amputation. Serial magnetoencephalographic recordings were performed in both patients. Only case 2 showed significant changes of cortical reorganization. In case 1 markedly less cortical plasticity was found. A combination of relevant risk factors such as a painful neuroma, behavioural and cognitive coping strategies and the early functional use of prostheses are discussed as important mechanisms contributing to the development of phantom pain and cortical reorganization. Copyright 2001 European Federation of Chapters of the International Association for the Study of Pain.

  9. Tissue-mimicking phantoms for photoacoustic and ultrasonic imaging

    Science.gov (United States)

    Cook, Jason R.; Bouchard, Richard R.; Emelianov, Stanislav Y.

    2011-01-01

    In both photoacoustic (PA) and ultrasonic (US) imaging, overall image quality is influenced by the optical and acoustical properties of the medium. Consequently, with the increased use of combined PA and US (PAUS) imaging in preclinical and clinical applications, the ability to provide phantoms that are capable of mimicking desired properties of soft tissues is critical. To this end, gelatin-based phantoms were constructed with various additives to provide realistic acoustic and optical properties. Forty-micron, spherical silica particles were used to induce acoustic scattering, Intralipid® 20% IV fat emulsion was employed to enhance optical scattering and ultrasonic attenuation, while India Ink, Direct Red 81, and Evans blue dyes were utilized to achieve optical absorption typical of soft tissues. The following parameters were then measured in each phantom formulation: speed of sound, acoustic attenuation (from 6 to 22 MHz), acoustic backscatter coefficient (from 6 to 22 MHz), optical absorption (from 400 nm to 1300 nm), and optical scattering (from 400 nm to 1300 nm). Results from these measurements were then compared to similar measurements, which are offered by the literature, for various soft tissue types. Based on these comparisons, it was shown that a reasonably accurate tissue-mimicking phantom could be constructed using a gelatin base with the aforementioned additives. Thus, it is possible to construct a phantom that mimics specific tissue acoustical and/or optical properties for the purpose of PAUS imaging studies. PMID:22076278

  10. Optimized generation of high resolution breast anthropomorphic software phantoms

    Science.gov (United States)

    Pokrajac, David D.; Maidment, Andrew D. A.; Bakic, Predrag R.

    2012-01-01

    Purpose: The authors present an efficient method for generating anthropomorphic software breast phantoms with high spatial resolution. Employing the same region growing principles as in their previous algorithm for breast anatomy simulation, the present method has been optimized for computational complexity to allow for fast generation of the large number of phantoms required in virtual clinical trials of breast imaging. Methods: The new breast anatomy simulation method performs a direct calculation of the Cooper’s ligaments (i.e., the borders between simulated adipose compartments). The calculation corresponds to quadratic decision boundaries of a maximum a posteriori classifier. The method is multiscale due to the use of octree-based recursive partitioning of the phantom volume. The method also provides user-control of the thickness of the simulated Cooper’s ligaments and skin. Results: Using the proposed method, the authors have generated phantoms with voxel size in the range of (25–1000 μm)3/voxel. The power regression of the simulation time as a function of the reciprocal voxel size yielded a log-log slope of 1.95 (compared to a slope of 4.53 of our previous region growing algorithm). Conclusions: A new algorithm for computer simulation of breast anatomy has been proposed that allows for fast generation of high resolution anthropomorphic software phantoms. PMID:22482649

  11. OSL Based Anthropomorphic Phantom and Real-Time Organ Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    David E. Hintenlang, Ph.D

    2009-02-10

    The overall objective of this project was the development of a dosimetry system that provides the direct measurement of organ does in real-time with a sensitivity that makes it an effective tool for applications in a wide variety of health physics applications. The system included the development of a real-time readout system for fiber optic coupled (FOC) dosimeters that is integrated with a state-of-art anthropomorphic phantom to provide instantaneous measures of organ doses throughout the phantom. The small size of the FOC detectors and optical fibers allow the sensitive volume of the detector to be located at organ centroids (or multiple locations distributed through the organ) within a tissue equivalent, anthropomorphic phantom without perturbing the tissue equivalent features of the phantom. The developed phantom/dosimetry system can be used in any environment where personnel may be exposed to gamma or x-ray radiations to provide the most accurate determinations of organ and effective doses possible to date.

  12. Capturing the Perceived Phantom Limb through Virtual Reality

    Directory of Open Access Journals (Sweden)

    Christian Rogers

    2016-01-01

    Full Text Available Phantom limb is the sensation amputees may feel when the missing limb is still attached to the body and is still moving as it would if it still existed. Despite there being between 50 and 80% of amputees who report neuropathic pain, also known as phantom limb pain (PLP, there is still little understanding of why PLP occurs. There are no fully effective long-term treatments available. One of the struggles with PLP is the difficulty for amputees to describe the sensations of their phantom limbs. The sensations may be of a limb that is in a position that is impossible for a normal limb to attain. The goal of this project was to treat those with PLP by developing a system to communicate the sensations those with PLP were experiencing accurately and easily through various hand positions using a model arm with a user friendly interface. The system was developed with Maya 3D animation software, the Leap Motion input device, and the Unity game engine. The 3D modeled arm was designed to mimic the phantom sensation being able to go beyond normal joint extensions of regular arms. The purpose in doing so was to obtain a true 3D visualization of the phantom limb.

  13. High resolution, MRI-based, segmented, computerized head phantom

    Energy Technology Data Exchange (ETDEWEB)

    Zubal, I.G.; Harrell, C.R.; Smith, E.O.; Smith, A.L.; Krischlunas, P. [Yale Univ., New Haven, CT (United States). Dept. of Diagnostic Radiology

    1999-01-01

    The authors have created a high-resolution software phantom of the human brain which is applicable to voxel-based radiation transport calculations yielding nuclear medicine simulated images and/or internal dose estimates. A software head phantom was created from 124 transverse MRI images of a healthy normal individual. The transverse T2 slices, recorded in a 256x256 matrix from a GE Signa 2 scanner, have isotropic voxel dimensions of 1.5 mm and were manually segmented by the clinical staff. Each voxel of the phantom contains one of 62 index numbers designating anatomical, neurological, and taxonomical structures. The result is stored as a 256x256x128 byte array. Internal volumes compare favorably to those described in the ICRP Reference Man. The computerized array represents a high resolution model of a typical human brain and serves as a voxel-based anthropomorphic head phantom suitable for computer-based modeling and simulation calculations. It offers an improved realism over previous mathematically described software brain phantoms, and creates a reference standard for comparing results of newly emerging voxel-based computations. Such voxel-based computations lead the way to developing diagnostic and dosimetry calculations which can utilize patient-specific diagnostic images. However, such individualized approaches lack fast, automatic segmentation schemes for routine use; therefore, the high resolution, typical head geometry gives the most realistic patient model currently available.

  14. Construction tool and suitability of voxel phantom for skin dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Paula C.G.; Siqueira, Paulo T.D.; Fonseca, Gabriel P.; Yoriyaz, Helio, E-mail: ptsiquei@ipen.b, E-mail: hyoriyaz@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    This paper describes a new software tool called 'SkinVop' which was developed to enable accurate voxel phantom skin dosimetry. A voxel phantom is a model used to describe human anatomy in a realistic way in radiation transport codes. This model is a three-dimensional representation of the human body in the form of an array of identification numbers that are arranged in a 3D matrix. Each entry in this array represents a voxel (volume element) directly associated to the units of picture resolution (pixel) of medical images. Currently, these voxel phantoms, in association with the transport code MCNP (Monte Carlo N-Particle), have provided subsidies to the planning systems used on the hospital routine, once they afford accurate and personalized estimative of dose distribution. However, these assessments are limited to geometric representations of organs and tissues in the voxel phantom, which do not discriminates some thin body structure, such as the skin. In this context, to enable accurate dosimetric skin dose assessment by the MCNP code, it was developed this new software tool that discriminates this region with thickness and localization in the voxel phantoms similar to the real. This methodology consists in manipulating the skin volume elements by segmenting and subdividing them in different thicknesses. A graphical user interface was designed to fulfill display the modified voxel model. This methodology is extremely useful once the skin dose is inaccurately assessed of current hospital system planning, justified justly by its small thickness. (author)

  15. Radiological equipment analyzed by specific developed phantoms and software

    Energy Technology Data Exchange (ETDEWEB)

    Soto, M.; Campayo, J. M. [Logistica y Acondicionamientos Industriales SAU, Sorolla Center, Local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Mayo, P. [TITANIA Servicios Tecnologicos SL, Sorolla Center, Local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Verdu, G.; Rodenas, F., E-mail: m.soto@lainsa.co [ISIRYIM Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia (Spain)

    2010-10-15

    The use of radiographic phantoms specifically designed to evaluate the operation of the radiographic equipment lets the study of the image quality obtained by this equipment in an objective way. In digital radiographic equipment, the analysis of the image quality can be computerized because the acquisition of the image is possible in different technologies that are, computerized radiography or phosphor plate and direct radiography or detector. In case of film-screen equipment s this analysis could be applied digitalising the image in a professional scanner. In this work we have shown an application to assess automatically the constancy quality image in the image chain of the radiographic equipment s. This application is integrated by designed radiographic phantoms which are adapted to conventional, dental equipment s and specific developed software for the automatic evaluation of the phantom image quality. The software is based on digital image processing techniques that let the automatic detection of the different phantom tests by edge detector, morphological operators, threshold histogram techniques... etc. The utility developed is enough sensitive to the radiographic equipment of operating conditions of voltage (kV) and charge (m As). It is a friendly user programme connected with a data base of the hospital or clinic where it has been used. After the phantom image processing the user can obtain an inform with a resume of the imaging system state with accepting and constancy results. (Author)

  16. Quadrature Slotted Surface Coil Pair for Magnetic Resonance Imaging at 4 Tesla: Phantom Study

    Directory of Open Access Journals (Sweden)

    Solis S.E.

    2012-01-01

    Full Text Available A coil array was composed of two slotted surface coils forming a structure with two plates at 900, each one having 6 circular slots and is introduced in this paper. Numerical simulations of the magnetic field of this coil array were performed at 170 MHz using the finite element method to study its behaviour. This coil array was developed for brain magnetic resonance imaging to be operated at the resonant frequency of 170 MHz in the transceiver mode and quadrature driven. Numerical simulations demonstrated that electromagnetic interaction between the coil elements is negligible, and that the magnetic field showed a good uniformity. Phantom images were acquired with our coil array and standard pulse sequences on a research-dedicated 4 Tesla scanner. In vitro images showed the feasibility of this coil array for standard pulses and high field magnetic resonance imaging.

  17. [Ulcerated plaque in the terminal aorta as a source of recurrent embolism in the young patient].

    Science.gov (United States)

    Barba, A; Escribano, J V; García-Alfageme, A

    1990-01-01

    In the last years, some case reports about peripheral arterial embolism originated from ulcerative disorders in the wall of aorta and main vascular structures, have been published. Patients affected by this disease are usually aged and arteriosclerotic injuries at divers levels are common. The current case report presents a patient, 37 years old, with a history of 3 surgical procedures because of recurrent arterial embolism in the left femoro-popliteal area with unknown embolic origin. Further, a complete angiographic exploration was realized because a new occlusion in the left ileo-femoral area occurred and suspicious images of an ulcerative atheroma plaque in final aorta were found. This conjecture was confirmed during surgical procedure. It should be noted that some histories of peripheral embolism, with unknown origin, in young patients could be caused by this type of disorders.

  18. Dissecção espontânea da aorta abdominal infrarrenal

    OpenAIRE

    Camargo Junior,Otacílio de; Chrispim,Antonio Cláudio Guedes; Simões,Claudio Roberto Cabrini; Marcondes,Márcia Fayad; Abreu,Guilherme Camargo Gonçalves de; Meirelles,Guilherme Vieira; Moraes,Kelly Cristina de; Freitas,Marcio Villar de; Araújo,Marivan Pedra; Murta,Gustavo Braga

    2012-01-01

    A rotura da camada íntima que marca o início da dissecção aórtica se origina na maioria dos casos na aorta torácica, sendo rara a dissecção espontânea da aorta abdominal infra-renal. As três principais causas são: iatrogênica, traumática ou espontânea. A dor abdominal e a isquemia de membros são os sintomas mais comuns e um número significativo de pacientes e´ assintomatico. O diagnóstico tem sido feito através de métodos de imagem como ultrassonografia, tomografia computadorizada, ressonânci...

  19. Explantation of infected aortic aneurysm and endograft with ascending aorta to mesenteric bypass for mesenteric ischemia.

    Science.gov (United States)

    Gates, Lindsay; Chin, Jason A; Bonde, Pramod N; Ochoa Chaar, Cassius I; Sumpio, Bauer E; Sarac, Timur P

    2017-01-01

    A 65-year-old man presented with an infected perivisceral aortic aneurysm after previous treatment of an abdominal aortic aneurysm with an endograft. On presentation, he was septic and had occlusion of the celiac, superior mesenteric, inferior mesenteric, and bilateral renal arteries. He underwent a three-stage procedure: first, axillobifemoral bypass; then resection of the thoracoabdominal aorta; and finally bypass from the ascending aorta to the celiac and superior mesenteric arteries with a rifampin-soaked Gelsoft graft (Vascutek, Renfrewshire, Scotland). The abdominal pain resolved, and the patient remains symptom free 10 months postoperatively. This rare surgical revascularization technique offered a nontraditional solution to a difficult surgical issue. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  20. Fluid structure interaction (FSI) simulation of bileaflet mechanical heart valve in an anatomic aorta geometry

    Science.gov (United States)

    Ge, Liang; Borazjani, Iman; Dasi, Lakshmi; Sotiropoulos, Fotis; Yoganathan, Ajit

    2007-11-01

    FSI simulation of a medical quality BMHV implanted in the aortic position is studied. The valve is implanted in an anatomic non-compliant aorta geometry, which is reconstructed from MRI data acquired from a healthy volunteer. A physiological incoming flow waveform is specified at the inlet with the peak systolic Reynolds number equal to 6000. The flow solver is based on the CURVIB (curvilinear immersed boundary method) of Ge and Sotiropoulos, 2007 (JCP) and the FSI problem is solved with strong coupling partitioned approach. Direct numerical simulation is carried out on a grid system consisting of 10M grid nodes. The impact on hemodynamics by valve implantation is studied by considering different valve implantation angles. The calculated numerical results are analyzed in terms of leaflet kinematics and flow physics, and compared with data from our previous work, where the same valve is implanted in a simplified straight aorta geometry.

  1. Plaque of atherosclerosis in aorta: review on atherogenesis, formation of plaque, clinical significance, methods of imaging and treatment; Placa de aterosclerose em aorta: revisao sobre aterogenese, formacao de placa, significado clinco, metodos de imagens e tratamento

    Energy Technology Data Exchange (ETDEWEB)

    Furtado, Rogerio Gomes; Nunes, Colandy G. de Oliveira; Rassi Junior, Luis; Melato, Luciano Henrique; Turco, Fabio de Paula; Borges, Moises Marcos, E-mail: rogerinhofurtado@gmail.com [Centro de Diagnostico por Imagem (CDI), Goiania, GO (Brazil); Sara, Leonardo [Instituto do Coracao (InCor/FM/USP), Sao Paulo, SP (Brazil)

    2009-04-15

    There is a certain consensus in the literature that the earliest stage of atherogenesis is characterized by the accumulation of spongy cells in the region of the intimal artery. Risk factors such as arterial hypertension, smoking, diabetes mellitus, hypercholesterolemia, male gender and advanced age predispose a person to the formation of plaques in the coronaries and aorta. A greater number of acute coronary events as well as strokes have been observed in people with these risk factors. Strokes are the third cause of death in the USA, with about 40% of the cases being of cryptogenic origin. Since 1989 the atheroma plaques which develop in the thoracic aorta have been considered to be responsible for cerebral and peripheral strokes which were previously considered cryptogenic because imaging techniques such as electrocardiogram transesophageal, computerized tomogram, nuclear magnetic angio-resonance have visualized and characterized the lesions with plaques of arteriosclerosis in the thoracic aorta. The authors of this article made a systematic review in the PUBMED about arteriosclerosis in the aorta and its diagnostic methods. This review includes the physiopathology of the formation of atheroma to the aorta and its consequences, diagnostic methods such as echo transesophageal, computerized tomogram and angio resonance, as well as the advantages and disadvantages of each method of identification of the lesions. An analysis of the clinical significance of the size, form and location of the atheroma plaques in the thoracic aorta were made based on clinical studies, as well as their treatment with anticoagulants, antiplatelet and drugs to reduce cholesterol. (author)

  2. 18F-FDG PET/CT for Detection Sarcoma of the Aorta in a Patient with Takayasu Arteritis

    Energy Technology Data Exchange (ETDEWEB)

    Yakahashi, Tomoko; Watanabe, Naoto; Wakasa Minoru; Kajinami, Kouji; Tonami, Hisao [Kazazawa Medical Univ., Ishikawa (Japan)

    2016-06-15

    Sarcoma of the aorta is extremely rare; however, 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging is a useful modality for detecting malignant tumors, including various sarcomas. We report on a case of sarcoma of the aorta associated concomitantly with Takayasu arteritis. The 18F-FDG PET/CT detected an abnormal increased up take in an aortic mass of the descending thoracic aorta, thoracic vertebra, and ilium. The standardized uptake value (SUV) of 18F-FDG in the aortic mass was 21.7, suggesting that 18F-FDG PET/CT imaging may be useful for detecting sarcoma of the aorta associated with Takayasu arteritis and bone metatases during treatment.

  3. Expression of p-PPARγ in the aging thoracic aorta of spontaneously hypertensive rat and inhibitory effect of rosiglitazone

    Directory of Open Access Journals (Sweden)

    Hai-Feng Yuan

    2014-12-01

    Conclusions: The PPARγ phosphorylation was observed in the thoracic aorta of SHR and its expression was increased by the increase of age. Furthermore, rosiglitazone inhibited the PPARγ phosphorylation and suppressed vascular aging in SHR.

  4. Aneurysms in Aorta and Bilateral Carotid Arteries in a Patient with Takayasu%u2019s Arteritis

    Directory of Open Access Journals (Sweden)

    Onur Ergun

    2014-03-01

    Full Text Available We aimed to present pre and postoperative angiographies for aneurysms in ascending and toracoabdominal aorta and bilateral common carotid arteries in a patient with Takayasu’ s arteritis

  5. Induced sensorimotor brain plasticity controls pain in phantom limb patients

    Science.gov (United States)

    Yanagisawa, Takufumi; Fukuma, Ryohei; Seymour, Ben; Hosomi, Koichi; Kishima, Haruhiko; Shimizu, Takeshi; Yokoi, Hiroshi; Hirata, Masayuki; Yoshimine, Toshiki; Kamitani, Yukiyasu; Saitoh, Youichi

    2016-01-01

    The cause of pain in a phantom limb after partial or complete deafferentation is an important problem. A popular but increasingly controversial theory is that it results from maladaptive reorganization of the sensorimotor cortex, suggesting that experimental induction of further reorganization should affect the pain, especially if it results in functional restoration. Here we use a brain–machine interface (BMI) based on real-time magnetoencephalography signals to reconstruct affected hand movements with a robotic hand. BMI training induces significant plasticity in the sensorimotor cortex, manifested as improved discriminability of movement information and enhanced prosthetic control. Contrary to our expectation that functional restoration would reduce pain, the BMI training with the phantom hand intensifies the pain. In contrast, BMI training designed to dissociate the prosthetic and phantom hands actually reduces pain. These results reveal a functional relevance between sensorimotor cortical plasticity and pain, and may provide a novel treatment with BMI neurofeedback. PMID:27807349

  6. Induced sensorimotor brain plasticity controls pain in phantom limb patients.

    Science.gov (United States)

    Yanagisawa, Takufumi; Fukuma, Ryohei; Seymour, Ben; Hosomi, Koichi; Kishima, Haruhiko; Shimizu, Takeshi; Yokoi, Hiroshi; Hirata, Masayuki; Yoshimine, Toshiki; Kamitani, Yukiyasu; Saitoh, Youichi

    2016-10-27

    The cause of pain in a phantom limb after partial or complete deafferentation is an important problem. A popular but increasingly controversial theory is that it results from maladaptive reorganization of the sensorimotor cortex, suggesting that experimental induction of further reorganization should affect the pain, especially if it results in functional restoration. Here we use a brain-machine interface (BMI) based on real-time magnetoencephalography signals to reconstruct affected hand movements with a robotic hand. BMI training induces significant plasticity in the sensorimotor cortex, manifested as improved discriminability of movement information and enhanced prosthetic control. Contrary to our expectation that functional restoration would reduce pain, the BMI training with the phantom hand intensifies the pain. In contrast, BMI training designed to dissociate the prosthetic and phantom hands actually reduces pain. These results reveal a functional relevance between sensorimotor cortical plasticity and pain, and may provide a novel treatment with BMI neurofeedback.

  7. Three-dimensional printing of tissue phantoms for biophotonic imaging.

    Science.gov (United States)

    Wang, Jianting; Coburn, James; Liang, Chia-Pin; Woolsey, Nicholas; Ramella-Roman, Jessica C; Chen, Yu; Pfefer, T Joshua

    2014-05-15

    We have investigated the potential of tissue phantoms fabricated with thermosoftening- and photopolymerization-based three-dimensional (3D) printers for use in evaluation of biophotonic imaging systems. The optical properties of printed polymer samples were measured and compared to biological tissues. Phantoms with subsurface channels as small as 0.2 mm in diameter were fabricated and imaged with microscopy, x-ray microtomography, and optical coherence tomography to characterize morphology. These phantoms were then implemented to evaluate the penetration depth of a hyperspectral reflectance imaging system used in conjunction with a near-infrared contrast agent. Results indicated that 3D printing may provide a suitable platform for performance testing in biophotonics, although subsurface imaging is critical to mitigate printer-to-printer variability in matrix homogeneity and feature microstructure.

  8. Computational hybrid anthropometric paediatric phantom library for internal radiation dosimetry

    DEFF Research Database (Denmark)

    Xie, Tianwu; Kuster, Niels; Zaidi, Habib

    2017-01-01

    covering statistical distributions of body morphometry in the paediatric population. The paediatric phantoms of the Virtual Population Series (IT'IS Foundation, Switzerland) were modified to match target anthropometric parameters, including body mass, body length, standing height and sitting height...... to create 1100 female and male phantoms with 10th, 25th, 50th, 75th and 90th body morphometries. Evaluation was performed qualitatively using 3D visualization and quantitatively by analysing internal organ masses. Overall, the newly generated phantoms appear very reasonable and representative of the main...... characteristics of the paediatric population at various ages and for different genders, body sizes and sitting stature ratios. The mass of internal organs increases with height and body mass. The comparison of organ masses of the heart, kidney, liver, lung and spleen with published autopsy and ICRP reference data...

  9. Study of digital mammographic equipments by phantom image quality.

    Science.gov (United States)

    Mayo, P; Rodenas, F; Verdú, G; Campayo, J M; Villaescusa, J I

    2006-01-01

    Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast-detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is CDMAM 3.4. One of the most extended indexes to measure the image quality in an objective way is the image quality figure (IQF). The aim of this work is to study the image quality of different images contrast-detail phantom CDMAM 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments that facilitates the evaluation of image contrast and detail resolution.

  10. Vasorelaxant action of aqueous extract of the leaves of Persea americana on isolated thoracic rat aorta.

    Science.gov (United States)

    Owolabi, Mbang A; Jaja, Smith I; Coker, Herbert A B

    2005-09-01

    The present study investigated the vasorelaxant action of the aqueous leaves extract of Persea americana on isolated rat aorta. The results showed that the extract produced significant vasorelaxation and that the effect is dependent on the synthesis or release of endothelium-derived relaxing factors (EDRFs) as well as the release of prostanoid. The extract also reduced vasoconstriction probably by inhibiting Ca2+ influx through calcium channels.

  11. Effect of Levodropropizine on isolated rabbit aorta contracted with phenylephrine and its Relationship with calcium

    OpenAIRE

    cankara, fatma nihan; çiçek, ekrem

    2014-01-01

    Objective: The aim of this study was to investigate the relationship between calcium (Ca+2) channels and levodropropizine, also to compare the potency of diltiazem and levodropropizine on phenylephrine pre-contracted rabbit aortic rings. Mateial-Method: 2-3 mm width rings of thoracic aorta were removed and suspended in 25 ml organ baths containing Krebs-Henseleit solution to reach baseline tension. To investigate contraction inhibiting effect of levodropropizine, Ca+2 free Krebs solution was ...

  12. Effects of Mistletoe on the lipid profile and aorta of Triton WR-1339 ...

    African Journals Online (AJOL)

    The effect of mistletoe on the lipid profile and aorta of triton wr-1339 treated Wistar rats was investigated in this study. 30 male Wistar rats (150g to 200g final weight) were divided into 6 groups of 5 rats each and were fed on normal rat chows, treated with triton and/or mistletoe extract for 6 weeks. The group treated with triton ...

  13. Pigtail catheter fracture and embolization into the abdominal aorta: an extremely rare angiographic complication.

    Science.gov (United States)

    Akpinar, Ibrahim; Dogan, Sait M; Karabag, Turgut; Sayin, Muhammet R; Kucuk, Emrah; Buyukates, Mustafa; Turan, Sitki A; Aydin, Mustafa

    2012-10-01

    Coronary angiography is a widely used diagnostic method for coronary artery disease. In clinical practice, although complications of the procedure often involve the vascular access point, there is no previous report of the fracture and embolization of the distal tip of a pigtail catheter. Herein, we present the case of a 51-year-old woman whose left ventriculography was interrupted by fracture of the curved tip of a pigtail catheter, which remained at the renal artery level in the abdominal aorta.

  14. Computer-aided patch planning for treatment of complex coarctation of the aorta

    Science.gov (United States)

    Rietdorf, Urte; Riesenkampff, Eugénie; Kuehne, Titus; Huebler, Michael; Meinzer, Hans-Peter; Wolf, Ivo

    2009-02-01

    Between five and eight percent of all children born with congenitally malformed hearts suffer from coarctations of the aorta. Some severe coarctations can only be treated by surgical repair. Untreated, this defect can cause serious damage to organ development or even lead to death. Patch repair requires open surgery. It can affect patients of any age: newborns with severe coarctation and/or hypoplastic aortic arch as well as older patients with late diagnosis of coarctation of the aorta. Another patient group are patients of varying age with re-coarctation of the aorta or hypoplastic aortic arch after surgical and/or interventional repair. If anatomy is complex and interventional treatment by catheterization, balloon angioplasty or stent placement is not possible, surgery is indicated. The choice of type of surgery depends not only on the given anatomy but also on the experience the surgical team has with each method. One surgical approach is patch repair. A patch of a suitable shape and size is sewed into the aorta to expand the aortic lumen at the site of coarctation. At present, the shape and size of the patch are estimated intra-operatively by the surgeon. We have developed a software application that allows planning of the patch pre-operatively on the basis of magnetic resonance angiographic data. The application determines the diameter of the coarctation and/or hypoplastic segment and constructs a patch proposal by calculating the difference to the normal vessel diameter pre-operatively. Evaluation of MR angiographic datasets from 12 test patients with different kinds of aortic arch stenosis shows a divergence of only (1.5+/-1.2) mm in coarctation diameters between manual segmentations and our approach, with comparable time expenditure. Following this proposal the patch can be prepared and adapted to the patient's anatomy pre-operatively. Ideally, this leads to shorter operation times and a better long-term outcome with a reduced rate of residual stenosis and

  15. Anatomy of the bovine ascending aorta and brachiocephalic artery found unfavorable for total artificial heart implant.

    Science.gov (United States)

    Karimov, Jamshid H; Sunagawa, Gengo; Such, Kimberly A; Sale, Shiva; Golding, Leonard A R; Moazami, Nader; Fukamachi, Kiyotaka

    2015-12-01

    The biocompatibility assessment of the Cleveland Clinic continuous-flow total artificial heart is an important part of the device developmental program. Surgical and postoperative management are key factors in achieving optimal outcomes. However, the presence of vascular anatomical abnormalities in experimental animal models is often unpredictable and may worsen the expected outcomes. We report a technical impediment encountered during total artificial heart implantation complicated by unfavorable bovine anatomy of the ascending aorta and brachiocephalic arterial trunk.

  16. Cloning of rat aorta lysyl oxidase cDNA: Complete codons and predicted amino acid sequence

    Energy Technology Data Exchange (ETDEWEB)

    Trackman, P.C.; Pratt, A.M.; Wolanski, A.; Tang, Shiowshih; Offner, G.D.; Troxler, R.F.; Kagan, H.M. (Boston Univ. School of Medicine, MA (USA))

    1990-05-22

    Lysyl oxidase cDNA clones were identified by their reactivity with anti-bovine lysyl oxidase in a neonatal rat aorta cDNA {lambda}gt11 expression library. A 500-bp cDNA sequence encoding four of six peptides derived from proteolytic digests of bovine aorta lysyl oxidase was found from the overlapping cDNA sequences of two positive clones. The library was rescreened with a radiolabeled cDNA probe made from one of these clones, thus identifying an additional 13 positive clones. Sequencing of the largest two of these overlapping clones resulted in 2,672 bp of cDNA sequence containing partial 5{prime}- and 3{prime}-untranslated sequences of 286 and 1,159 nucleotides, respectively, and a complete open reading frame of 1,227 bp encoding a polypeptide of 409 amino acids (46 kDa), consistent with the 48 {plus minus} 3 kDa cell-free translation product of rat smooth muscle cell RNA that was immunoprecipitated by anti-bovine lysyl oxidase. The rat aorta cDNA-derived amino acid sequence contains the sequence of each of the six peptides isolated and sequenced from the 32-kDa bovine aorta enzyme, including the C-terminal peptide with sequence identity of 96%. Southern blotting of rat genomic DNA with lysyl oxidase cDNA probes indicated that the lysyl oxidase gene is located at a single locus and does not appear to be a member of a multigene family. A potential stem-loop structure was found in the 3{prime}-untranslated region of the cDNA. The deduced amino acid sequence contains a putative signal peptide, in addition to sequences that are similar to those of other known copper proteins.

  17. The effect of oxidation on the mechanical response and microstructure of porcine aortas.

    Science.gov (United States)

    Stephen, Elizabeth A; Venkatasubramaniam, Arundhathi; Good, Theresa A; Topoleski, L D Timmie

    2014-09-01

    Reactive oxygen species (ROS), a product of many cellular functions, has been implicated in many age-related pathophysiological processes, including cardiovascular disease. The arterial proteins collagen and elastin may also undergo structural and functional changes due to damage caused by ROS. This study examined the effect of oxidation on the mechanical response of porcine aortas and aorta elastin and the associated changes in structural protein ultrastructure as a step in exploring the role of molecular changes in structural proteins with aging on elastic artery function. We examined the change in mechanical properties of aorta samples after various oxidation times as a first step in understanding how the oxidative environment associated with aging could impact mechanical properties of arterial structural proteins. We used confocal microscopy to visualize how the microstructure of isolated elastin changed with oxidation. We find that short term oxidation of elastin isolated from aortas leads to an increase in material stiffness, but also an increase in the fiber diameter, increase in void space in the matrix, and a decrease in the fiber orientation, possibly due to fiber cross-linking. The short term effects of oxidation on arterial collagen is more complex, with increase in material stiffness seen in the collagen region of the stress stretch curve at low extents of oxidation, but not at high levels of oxidation. These results may provide insight into the relationship between oxidative damage to tissue associated with aging and disease, structure of the arterial proteins elastin and collagen, and arterial mechanical properties and function. © 2013 Wiley Periodicals, Inc.

  18. Circumferential variations of mechanical behavior of the porcine thoracic aorta during the inflation test.

    Science.gov (United States)

    Kim, Jungsil; Baek, Seungik

    2011-07-07

    We developed an extension-inflation experimental apparatus with a stereo vision system and a stress-strain analysis method to determine the regional mechanical properties of a blood vessel. Seven proximal descending thoracic aortas were investigated during the inflation test at a fixed longitudinal stretch ratio of 1.35 over a transmural pressure range from 1.33 to 21.33 kPa. Four circumferential regions of each aorta were designated as the anterior (A), left lateral (L), posterior (P), and right lateral (R) regions, and the inflation test was repeated for each region of the aortas. We used continuous functions to approximate the surfaces of the regional aortic wall in the reference configuration and the deformed configuration. Circumferential stretch and stress at the four circumferential regions of the aorta were computed. Circumferential stiffness, defined as the tangent of the stress-stretch curve, and physiological aortic stiffness, named pressure-strain elastic modulus, were also computed for each region. In the low pressure range, the stress increased linearly with increased stretch, but the mechanical response became progressively stiffer in the high-pressure range above a transition point. At a transmural pressure of 12.00 kPa, mean values of stiffness were 416±104 kPa (A), 523±99 kPa (L), 634±91 kPa (P), and 489±82 kPa (R). The stiffness of the posterior region was significantly higher than that of the anterior region, but no significant difference was found in pressure-strain elastic modulus. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Levosimendan in a neonate with severe coarctation of aorta and low cardiac output syndrome

    Directory of Open Access Journals (Sweden)

    Yann Olivier Boegli

    2013-01-01

    Full Text Available We report successful use of levosimendan after failed balloon angioplasty in a critically ill neonate with coarctation of aorta (CoA and severe low cardiac output syndrome (LCOS. Treatment with levosimendan improved left heart function, and decreased lactate and brain natriuretic peptide levels. To our knowledge, this is the first report on the safe and successful use of levosimendan in the management of LCOS due to severe CoA in a neonate awaiting surgical repair.

  20. Treatment Strategies for Paradoxical Hypertension Following Surgical Correction of Coarctation of the Aorta in Children

    OpenAIRE

    Roeleveld, Peter P.; Zwijsen, Eline G.

    2017-01-01

    Background: Paradoxical hypertension after repair of coarctation of the aorta is a well-known phenomenon. The pathogenesis involves the activation of the sympathetic nervous system (first phase) and renin?angiotensin system (second phase). Only a limited number of different treatment strategies have been published in the literature, without any comparative studies. Methods: Our aim was to describe the current international practice variation surrounding pharmacological treatment currently bei...

  1. Primary motor cortex changes after amputation correlate with phantom limb pain and the ability to move the phantom limb

    DEFF Research Database (Denmark)

    Raffin, Estelle; Richard, Nathalie; Giraux, Pascal

    2016-01-01

    A substantial body of evidence documents massive reorganization of primary sensory and motor cortices following hand amputation, the extent of which is correlated with phantom limb pain. Many therapies for phantom limb pain are based upon the idea that plastic changes after amputation are maladap......A substantial body of evidence documents massive reorganization of primary sensory and motor cortices following hand amputation, the extent of which is correlated with phantom limb pain. Many therapies for phantom limb pain are based upon the idea that plastic changes after amputation...... are maladaptive and attempt to normalize representations of cortical areas adjacent to the hand area. Recent data suggest, however, that higher levels of phantom pain are associated with stronger local activity and more structural integrity in the missing hand area rather than with reorganization of neighbouring...... body parts. While these models appear to be mutually exclusive they could co-exist, and one reason for the apparent discrepancy between them might be that no single study has examined the organisation of lip, elbow, and hand movements in the same participants. In this study we thoroughly examined the 3...

  2. Design and development of an ultrasound calibration phantom and system

    Science.gov (United States)

    Cheng, Alexis; Ackerman, Martin K.; Chirikjian, Gregory S.; Boctor, Emad M.

    2014-03-01

    Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the ultrasound transducer and the ultrasound image. A phantom or model with known geometry is also required. In this work, we design and test an ultrasound calibration phantom and software. The two main considerations in this work are utilizing our knowledge of ultrasound physics to design the phantom and delivering an easy to use calibration process to the user. We explore the use of a three-dimensional printer to create the phantom in its entirety without need for user assembly. We have also developed software to automatically segment the three-dimensional printed rods from the ultrasound image by leveraging knowledge about the shape and scale of the phantom. In this work, we present preliminary results from using this phantom to perform ultrasound calibration. To test the efficacy of our method, we match the projection of the points segmented from the image to the known model and calculate a sum squared difference between each point for several combinations of motion generation and filtering methods. The best performing combination of motion and filtering techniques had an error of 1.56 mm and a standard deviation of 1.02 mm.

  3. Realistic deformable 3D numeric phantom for transcutaneous ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Fernando Mitsuyama; Moraes, Matheus Cardoso; Furuie, Sergio Shiguemi, E-mail: fernando.okara@gmail.com [Universidade de Sao Paulo (USP), SP (Brazil). Escola de Engenharia

    2017-01-15

    Introduction: Numerical phantoms are important tools to design, calibrate and evaluate several methods in various image-processing applications, such as echocardiography and mammography. We present a framework for creating ultrasound numerical deformable phantoms based on Finite Element Method (FEM), Linear Isomorphism and Field II. The proposed method considers that the scatterers map is a property of the tissue; therefore, the scatterers should move according to the tissue strain. Methods: First, a volume representing the target tissue is loaded. Second, parameter values, such as Young's Modulus, scatterers density, attenuation and scattering amplitudes are inserted for each different regions of the phantom. Then, other parameters related to the ultrasound equipment, such as ultrasound frequency and number of transducer elements, are also defined in order to perform the ultrasound acquisition using Field II. Third, the size and position of the transducer and the pressures that are applied against the tissue are defined. Subsequently, FEM is executed and deformation is computed. Next, 3D linear isomorphism is performed to displace the scatterers according to the deformation. Finally, Field II is carried out to generate the non-deformed and deformed ultrasound data. Results: The framework is evaluated by comparing strain values obtained the numerical simulation and from the physical phantom from CIRS. The mean difference between both phantoms is lesser than 10%. Conclusion: The acoustic and deformation outcomes are similar to those obtained using a physical phantom. This framework led to a tool, which is available online and free of charges for educational and research purposes. (author)

  4. Polyvinyl chloride plastisol breast phantoms for ultrasound imaging.

    Science.gov (United States)

    de Carvalho, Isabela Miller; De Matheo, Lucas Lobianco; Costa Júnior, José Francisco Silva; Borba, Cecília de Melo; von Krüger, Marco Antonio; Infantosi, Antonio Fernando Catelli; Pereira, Wagner Coelho de Albuquerque

    2016-08-01

    Ultrasonic phantoms are objects that mimic some features of biological tissues, allowing the study of their interactions with ultrasound (US). In the diagnostic-imaging field, breast phantoms are an important tool for testing performance and optimizing US systems, as well as for training medical professionals. This paper describes the design and manufacture of breast lesions by using polyvinyl chloride plastisol (PVCP) as the base material. Among the materials available for this study, PVCP was shown to be stable, durable, and easy to handle. Furthermore, it is a nontoxic, nonpolluting, and low-cost material. The breast's glandular tissue (image background) was simulated by adding graphite powder with a concentration of 1% to the base material. Mixing PVCP and graphite powder in differing concentrations allows one to simulate lesions with different echogenicity patterns (anechoic, hypoechoic, and hyperechoic). From this mixture, phantom materials were obtained with speed of sound varying from 1379.3 to 1397.9ms(-1) and an attenuation coefficient having values between 0.29 and 0.94dBcm(-1) for a frequency of 1MHz at 24°C. A single layer of carnauba wax was added to the lesion surface in order to evaluate its applicability for imaging. The images of the phantoms were acquired using commercial ultrasound equipment; a specialist rated the images, elaborating diagnoses representative of both benign and malignant lesions. The results indicated that it was possible to easily create a phantom by using low-cost materials, readily available in the market and stable at room temperature, as the basis of ultrasonic phantoms that reproduce the image characteristics of fatty breast tissue and typical lesions of the breast. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. [Morphologic and morphometric analysis of atheromatous changes in the aorta in silibinin-treated cholesterin-fed rabbits].

    Science.gov (United States)

    Schneider, F; Hídvégi, J; Bártfai, Z; Somogyi, A; Blázovics, A

    1990-07-01

    Authors studied the effect of Silibinin of antioxidative effect on cholesterin sclerosis of rabbits. Qualitative analysis of aorta sections, macroscopic and microscopic morphometric examination of aorta were the applied methods. Their results seem to show that Silibinin has a favourable influence on cholesterin sclerosis. According to their opinion only joint use of qualitative and quantitative macroscopic and microscopic methods can provide basis for really accurate judgment of any atheromatose change.

  6. Disección crónica de la aorta torácica.tratamiento abierto y endovascular

    Directory of Open Access Journals (Sweden)

    Juan Carlos Llosa

    2009-09-01

    El tratamiento de la disección crónica de la aorta descendente es discutido. La cirugía abierta, al permitir resecar amplias porciones de aorta patológica, tiene una buena supervivencia a largo plazo, aunque se trata de intervenciones muy agresivas. Por otra parte, el tratamiento endovascular podría reservarse para aquellos pacientes con alto riesgo para cirugía abierta.

  7. Transcriptional and phenotypic changes in aorta and aortic valve with aging and MnSOD deficiency in mice.

    Science.gov (United States)

    Roos, Carolyn M; Hagler, Michael; Zhang, Bin; Oehler, Elise A; Arghami, Arman; Miller, Jordan D

    2013-11-15

    The purpose of this study was to characterize changes in antioxidant and age-related gene expression in aorta and aortic valve with aging, and test the hypothesis that increased mitochondrial oxidative stress accelerates age-related endothelial and aortic valve dysfunction. Wild-type (MnSOD(+/+)) and manganese SOD heterozygous haploinsufficient (MnSOD(+/-)) mice were studied at 3 and 18 mo of age. In aorta from wild-type mice, antioxidant expression was preserved, although there were age-associated increases in Nox2 expression. Haploinsufficiency of MnSOD did not alter antioxidant expression in aorta, but increased expression of Nox2. When compared with that of aorta, age-associated reductions in antioxidant expression were larger in aortic valves from wild-type and MnSOD haploinsufficient mice, although Nox2 expression was unchanged. Similarly, sirtuin expression was relatively well-preserved in aorta from both genotypes, whereas expression of SIRT1, SIRT2, SIRT3, SIRT4, and SIRT6 were significantly reduced in the aortic valve. Expression of p16(ink4a), a marker of cellular senescence, was profoundly increased in both aorta and aortic valve from MnSOD(+/+) and MnSOD(+/-) mice. Functionally, we observed comparable age-associated reductions in endothelial function in aorta from both MnSOD(+/+) and MnSOD(+/-) mice. Interestingly, inhibition of NAD(P)H oxidase with apocynin or gp91ds-tat improved endothelial function in MnSOD(+/+) mice but significantly impaired endothelial function in MnSOD(+/-) mice at both ages. Aortic valve function was not impaired by aging or MnSOD haploinsufficiency. Changes in antioxidant and sirtuin gene expression with aging differ dramatically between aorta and aortic valve. Furthermore, although MnSOD does not result in overt cardiovascular dysfunction with aging, compensatory transcriptional responses to MnSOD deficiency appear to be tissue specific.

  8. Aorta Structural Alterations in Term Neonates: The Role of Birth and Maternal Characteristics

    Directory of Open Access Journals (Sweden)

    Marco Matteo Ciccone

    2013-01-01

    Full Text Available Aim. To evaluate the influence of selected maternal and neonatal characteristics on aorta walls in term, appropriately grown-for-gestational age newborns. Methods. Age, parity, previous abortions, weight, height, body mass index before and after delivery, smoking, and history of hypertension, of diabetes, of cardiovascular diseases, and of dyslipidemia were all assessed in seventy mothers. They delivered 34 males and 36 females healthy term newborns who underwent ultrasound evaluation of the anteroposterior infrarenal abdominal aorta diameter (APAO, biochemical profile (glucose, insulin, total cholesterol, HDL and LDL cholesterol, triglycerides, fibrinogen, and D-dimers homeostasis model assessment [HOMAIR]index, and biometric parameters. Results. APAO was related to newborn length (r=+0.36; P=0.001, head circumference (r=+0.37; P=0.001, gestational age (r=+0.40, P=0.0005, HOMA index (r=+0.24; P=0.04, and D-dimers (r=+0.33, P=0.004. Smoke influenced APAO values (odds ratio: 1.80; confidence interval 95%: 1.05–3.30, as well as diabetes during pregnancy (r=+0.42, P=0.0002. Maternal height influenced neonatal APAO (r=+0.47, P=0.00003. Multiple regression analysis outlined neonatal D-dimers as still significantly related to neonatal APAO values. Conclusions. Many maternal and neonatal characteristics could influence aorta structures. Neonatal D-dimers are independently related to APAO.

  9. Neurofibromatosis Type 1 Complicated by Atypical Coarctation of the Thoracic Aorta

    Directory of Open Access Journals (Sweden)

    Masato Kimura

    2013-01-01

    Full Text Available Neurofibromatosis type 1 (NF1 is a relatively common autosomal dominant genetic disorder with a prevalence of 1 in 3,000 (0.03% at birth. Clinical features are café-au-lait macules, intertriginous freckling, dermal neurofibroma, iris hamartoma (Lisch nodules, and learning disability. NF1 vasculopathy is a serious but underrecognized complication involving the cerebrovascular and cardiovascular systems. The incidence of hypertension in patients with NF1 is around 1% and is associated mainly with renal artery stenosis in children. Only a few cases of thoracic aortic coarctation in association with hypertension and neurofibromatosis have been reported. Here we describe the case of a 4-year-old girl who presented with NF1 and hypertension due to atypical coarctation of the thoracic aorta. The diagnosis of coarctation of the thoracic aorta at the Th5-to-Th6 level was made following catheterization with a pressure gradient of 40 mmHg. The patient underwent surgery comprising resection of the coarctation of the thoracic aorta and graft interposition. On the basis of our findings, annual assessment of blood pressure is advised for patients with NF1.

  10. Comparative effects of endothelin and phorbol 12-13 dibutyrate in rat aorta

    Energy Technology Data Exchange (ETDEWEB)

    Auguet, M.; Delaflotte, S.; Chabrier, P.E.; Braquet, P. (Institut Henri Beaufour Research Labs., Cedex (France))

    1989-01-01

    The vasoconstrictive properties of endothelin (ET-1) and the protein kinase C activator, phorbol 12-13 dibutyrate (PDB) were comparatively investigated in isolated rat aorta. ET-1 and PDB induced a slowly developing sustained contraction in endothelium denuded aorta. Maximal contractions induced by ET-1 and PDB were unaffected by diltiazem. Substantial contraction to ET-1 and PDB remained in calcium-free medium. Contractions of ET-1 and PDB in calcium-free medium were unaffected by intracellular calcium depletion induced by phenylephrine. Following the response to ET-1 and PDB in a calcium-free medium, an additional sustained was observed after calcium was added to the bath. The protein kinase C inhibitor, H7 was more potent in inhibiting contractions induced by phenylephrine and KCl than the ones elicited by ET-1 and PDB. The other protein kinase C inhibitors i.e. staurosporine and phloretin inhibited to a similar extent all the agonists tested. These results suggest that protein kinase C may play an important role in mediating the contraction to ET-1 in rat aorta.

  11. Copper and mineral deficiency effects on porcine aortae and lung elastin crosslinks

    Energy Technology Data Exchange (ETDEWEB)

    Richmond, V.L.; Hansen, K. (Pacific Northwest Research Foundation, Seattle, WA (United States))

    1991-03-15

    Dietary copper was studied in mineral-deficient and -sufficient piglets. Three groups of newborn Yorkshire piglets were fed evaporated bovine milk-based copper-deficient mineral deficient diets as follows: Group A: copper-supplemented mineral-deficient; Group B: no additions, copper-deficient mineral-deficient; Group C: copper-deficient mineral-supplemented at mg/Kg/day: Mn 0.0994; Al 0.0097; Zn 0.082; Ni 0.132. Sacular dissecting aneurysms were 50% in Group C at days 87 and 108, whereas, none occurred in Groups A or B by day 168 to 180. Histological derangement of aortic elastic fibers occurred in Groups B and C. Lysyl-derived crosslinks of lysinonorleucine (LNL) in hot alkali-extracted elastin samples were 40% in Groups B and C compared with A for both lung and aortae elastic fibers. Desmosines were also decreased. Unmodified aortae lysyl residues were increased 64% in C compared to A, suggesting additional minerals decreased lysyl oxidase activity. Elastolysis of incompletely cross-linked elastic fibers may have contributed to decreased recoveries of insoluble elastin samples in aortae and especially in lung. Effects of minerals on copper metabolism when copper is limiting may be responsible for decreased strength of extracellular matrix.

  12. Gingival fibroblast inhibits MMP-7: evaluation in an ex vivo aorta model.

    Science.gov (United States)

    Gogly, Bruno; Fournier, Benjamin; Couty, Ludovic; Naveau, Adrien; Brasselet, Camille; Durand, Eric; Coulomb, Bernard; Lafont, Antoine

    2009-08-01

    Matrix metalloproteinases (MMP) play a deleterious role in numerous vascular diseases. In contrast, gingival matrix remodelling is adequately regulated by the gingival fibroblast (GF). Here, we aimed to evaluate the GF activity on MMP-7 expression and secretion in coculture with aorta rings. We evaluated MMP-7 transcription and secretion in rabbit aorta rings cultured or not with gingival fibroblasts in collagen gels. GF induced an increase of TIMP-1 transcription and secretion, followed, similarly to other MMPs, by the formation of TIMP-1/MMP-7 complexes. There was also a decrease of MMP-7 mRNA by RT-PCR in aorta rings cocultured with gingival fibroblasts. Interestingly, in contrast with other MMPs (which were not influenced at a transcription level), GF stimulated the release of TGF-beta1, which in turn inhibited the transcription and synthesis of MMP-7, as shown by neutralizing MMP-7 inhibition due to gingival fibroblast by overexpressing decorin (a TGF beta 1 inhibitor) or by silencing TGF beta 1 using siRNA. We showed that healing properties of the GF could be transposed to another organ, i.e., ex vivo aneurism model, implicating a down-regulation of MMP-7.

  13. Cardiovascular effects of Urtica dioica L. in isolated rat heart and aorta.

    Science.gov (United States)

    Legssyer, Abdelkhaleq; Ziyyat, Abderrahim; Mekhfi, Hassane; Bnouham, Mohamed; Tahri, Abdelhafid; Serhrouchni, Mohamed; Hoerter, Jacqueline; Fischmeister, Rodolphe

    2002-09-01

    Urtica dioica L. or Nettle (Urticaceae) is widely used in oriental Morocco to treat hypertension. Aqueous extract of Nettle (AEN) also exerts a hypotensive action in the rat in vivo. The aim of this work was to characterize the specific cardiac and vascular effects of AEN. In the isolated Langendorff perfused rat heart, AEN (1 and 2 g/l) markedly decreased heart rate and increased left ventricular pressure. Higher concentration (5 g/l) even led to cardiac arrest. Although carbachol mimicked the bradycardiac effect of AEN, atropine (a muscarinic receptor antagonist, 1 micro M) did not modify the response. Beside its action on myocardium, AEN also affected vascular contractility. Indeed, AEN (0.1-5 g/l) produced a dose-dependent increase in basal tone of isolated rat aorta. This effect was endothelium independent and was abolished by 1 micro M prazosin (an alpha1-adrenergic antagonist). AEN had little additional effects when the aorta was precontracted by noradrenaline (1 micro M) or KCl (40 mM). Our data indicate that AEN produces a vasoconstriction of the aorta which is due to activation of alpha1-adrenergic receptors. However, AEN also induces a strong bradycardia through non-cholinergic and non-adrenergic pathways which might compensate for its vascular effect and account for the hypotensive action of Urtica dioica L described in vivo. Copyright 2002 John Wiley & Sons, Ltd.

  14. Aneurisma de aorta com ruptura para esôfago Aortic aneurysm rupture into the esophagus

    Directory of Open Access Journals (Sweden)

    Christiano da Silveira de Barcellos

    2008-12-01

    Full Text Available Apresentamos o caso de uma paciente portadora de aneurisma de aorta descendente com ruptura para o esôfago que, após aortoplastia com interposição de tubo de dacron e rafia da laceração esofágica, evoluiu com fístula esôfago pleural no terceiro dia pós-operatório. A paciente necessitou de reintervenção e cuidados intensivos, reabilitando-se adequadamente. A propósito deste caso incomum e do aprendizado adquirido no seu manejo, revisamos a literatura a fim de discutir a melhor alternativa de correção desta rara e, freqüentemente, fatal forma de apresentação das doenças da aorta.We present the case of a patient with a descending aorta aneurysm rupture into the esophagus, which, after aortoplasty with Dacron tube interposition and suture of esophageal laceration, developed a pleural-esophagus fistula on the 3rd postoperative day. She needed re-intervention and intensive care, followed by adequate recovery. Considering this unusual case and the knowledge acquired through its management, we reviewed the literature in order to discuss the best alternative for the correction of this rare and often fatal form of presentation of aortic diseases.

  15. The anomalous origin of the branch pulmonary artery from the ascending aorta.

    Science.gov (United States)

    Garg, Pankaj; Talwar, Sachin; Kothari, Shyam Sunder; Saxena, Anita; Juneja, Rajnish; Choudhary, Shiv Kumar; Airan, Balram

    2012-07-01

    The anomalous origin of one pulmonary artery branch from the aorta (AOPA) is rare. We report our single-institution surgical experience with this condition. Between January 1994 and February 2011, 17 patients (age: 1 month-25 years) with AOPA underwent surgery at our institute. Thirteen patients had an anomalous origin of the right pulmonary artery (RPA) while four had an anomalous origin of the left pulmonary artery (LPA) from the aorta. In patients with anomalous RPA, 11 patients had the proximal type and two patients had the distal type of AOPA. Four patients had associated Tetralogy of Fallot (TOF). In 14 patients, direct implantation into the main pulmonary artery was performed, while three patients required interpositon of a graft. There was one operative death due to persistent hypoxia in a 7-month old child with TOF and an anomalous LPA from the aorta. At a median follow-up of 36.5 months (range: 2-192 months), all 16 survivors were asymptomatic. On echocardiography, two patients showed a gradient of 25 and 30 mmHg across the anastomosis and are being followed up. In our experience, early repair of AOPA results in acceptable haemodynamic and anatomic results. Long-term survival can be expected with a low incidence of re-operation or re-intervention.

  16. Anomalous origin of the right pulmonary artery from the ascending aorta.

    Science.gov (United States)

    Prifti, Edvin; Bonacchi, Massimo; Murzi, Bruno; Crucean, Adrian; Leacche, Marzia; Bernabei, Massimo; Bartolozzi, Fabio; Nathan, Nadia S; Vanini, Vittorio

    2004-01-01

    The aim was to review our experience with the surgical repair of the anomalous origin of the right pulmonary artery (AORPA) from the aorta. Between January 1991 and March 2001, five patients with AORPA underwent surgical correction. One patient presented isolated AOPA from the aorta. Implantation of the anomalous PA to the main PA trunk was performed by (1). direct anatomosis employing an autologous pericardial patch in two patients; (2). using an aortic flap in two patients with AORPA; and (3). using an aortic and pulmonary flaps in another patient. The mean follow-up time was 27 months. One patient died due to progressive heart failure unresponsive to inotropic support. Early postoperative pulmonary hypertension crisis was identified in patient 4, that was managed by intravenous prostacyclin. The same patient necessitated mechanical ventilation for 11 days. The mean residual gradient for all survivors was 9.5 +/- 4 mmHg. The postoperative Tc-99 m scintigraphy demonstrated 72 +/- 4.5(%) lung perfusion. At follow-up the survival was 100%. None of the followed patients required reoperation. The AORPA from the aorta is a rare but important entity, necessitating a scrupulous preoperative and intraoperative evaluation. The techniques employing autologous tissues for enlarging and lengthening the AORPA seem to be associated with better results in terms of postoperative restenosis.

  17. Reconstruction of a Damaged Lower Polar Artery for Kidney Transplantation Using Tubularised Donor Aorta

    Directory of Open Access Journals (Sweden)

    A. J. Vicéns-Morton

    2017-01-01

    Full Text Available Introduction. Live donors, extended donor criteria, and the maximum usage of organs with anatomical variants are some of the mechanisms used to increase the number of organs available. Case. We present the case of a kidney transplant, in which the organ had an iatrogenic injury to a lower pole arterial branch during retrieval. The donor was a 35-year-old male (DCD, Maastricht III. The right kidney was accepted; it had three veins in a single cava patch and three renal arteries, the main artery with aorta patch that is 8 cm long. A small lower pole artery was sectioned during retrieval surgery at approximately 1 cm from its origin as well as a third small mid-lower pole artery. The lower pole damaged artery was reconstructed using tubularised aorta patch to a total length of 5 cm. No additional donor vessels had been sent. After construction of the tubulised aorta, E-E anastomosis to the damaged polar artery was done with interrupted 7-0 Prolene sutures. Conclusion. While the waiting list for a kidney continues to rise and we continue to have organ shortness, vascular retrieval injury should not be an absolute contraindication for transplant.

  18. Conjugated equine estrogen treatment corrected the exacerbated aorta oxidative stress in ovariectomized spontaneously hypertensive rats.

    Science.gov (United States)

    Ceravolo, Graziela S; Filgueira, Fernando P; Costa, Tiago J; Lobato, Nubia S; Chignalia, Andréia Z; Araujo, Priscila X; Tostes, Rita C; Dantas, Ana P; Fortes, Zuleica B; Carvalho, Maria Helena C

    2013-03-01

    The increased risk of cardiovascular diseases in postmenopausal women has been linked to the decrease in plasma estrogen levels. Preparation of conjugate equine estrogens (CEE) is one of the most routinely used hormone therapy in postmenopausal women. However, studies on the vascular effects of CEE are still sparse and the mechanism of action is not completely elucidated. In this context, we have determined the effects of CEE in the vascular oxidative stress observed in ovariectomyzed (OVX) spontaneously hypertensive rats (SHR). Mechanisms by which CEE interferes with redox-sensitive pathways and endothelial function were also determined. Aortas from OVX rats exhibited increased generation of reactive oxygen species (ROS), NADPH oxidase activity and reduced catalase protein expression, compared to aortas from sham SHR. Endothelium-intact aortic rings from OVX were hyperreactive to NE when compared to Sham aortas. This hyperreactivity was corrected by superoxide dismutase (SOD), catalase, and endothelium removal. Treatment of OVX-SHR with CEE reduced vascular ROS generation, NADPH oxidase activity, enhanced SOD and catalase expression and also corrected the NE-hyperreactivity in aortic rings from OVX-SHR. Our study indicates a potential benefit of CEE therapy through a mechanism that involves reduction in oxidative stress, improving endothelial function in OVX hypertensive rats. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. CT images of an anthropomorphic and anthropometric male pelvis phantom

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Andrea S.D. de; Campos, Tarcisio P.R. de, E-mail: campos@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares

    2009-07-01

    Actually, among of the most often neoplasm types are the cancer of prostate, bladder and intestine. The incidence of the intestine neoplasm in Brazil is at fourth among the most frequent tumors of the male sex, barely close to the stomach, lung and prostate incidences. Phantoms are objects used as simulators for investigating ionizing radiation transport on humans, especially during radiation therapy or radiological diagnostic. The purpose of this work is the achievement of a set of computerized tomography (CT) images of a male pelvis phantom, with anthropomorphic and anthropometric features. It investigates and analyses the set of phantom CT images in according to a correspondent human pelvis one. The reason to develop a pelvis phantom is the needs of reproducing well established spatial dose distribution in radiation therapy, especially during calibration and protocol setup for various pelvis neoplasms. It aims to produce dose optimization on radiation therapy, improving health tissue protection and keeping control tumor dose. A male pelvis phantom with similar shape made of equivalent tissues was built for simulating the ionizing radiation transport to the human body. At the phantom, pelvis organs were reproduced including the bladder, the intestine, the prostate, the muscular and greasy tissue, as well as the bone tissue and the skin. A set of CT images was carried out in axial thin sections of 2mm thickness. As results, the constituent tissues had a tomography response on Hounsfield scale similar to values found on the human pelvis. Each tissue has its respective Hounsfield value, demonstrated here. The CT images also show that the organs have equivalent anthropometric measures and anthropomorphic features of the radiological human anatomy. The anatomical physical arrangement of the organs is also similar to of the pelvis human male, having the scales of gray and numerical scale of Hounsfield compatible with the scale of the human tissue. The phantom presents

  20. Viscosity-Induced Crossing of the Phantom Barrier

    Directory of Open Access Journals (Sweden)

    Iver Brevik

    2015-09-01

    Full Text Available We show explicitly, by using astrophysical data plus reasonable assumptions for the bulk viscosity in the cosmic fluid, how the magnitude of this viscosity may be high enough to drive the fluid from its position in the quintessence region at present time t = 0 across the barrier w = −1 into the phantom region in the late universe. The phantom barrier is accordingly not a sharp mathematical divide, but rather a fuzzy concept. We also calculate the limiting forms of various thermodynamical quantities, including the rate of entropy production, for a dark energy fluid near the future Big Rip singularity.

  1. Development of PIMAL: Mathematical Phantom with Moving Arms and Legs

    Energy Technology Data Exchange (ETDEWEB)

    Akkurt, Hatice [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eckerman, Keith F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2007-05-01

    The computational model of the human anatomy (phantom) has gone through many revisions since its initial development in the 1970s. The computational phantom model currently used by the Nuclear Regulatory Commission (NRC) is based on a model published in 1974. Hence, the phantom model used by the NRC staff was missing some organs (e.g., neck, esophagus) and tissues. Further, locations of some organs were inappropriate (e.g., thyroid).Moreover, all the computational phantoms were assumed to be in the vertical-upright position. However, many occupational radiation exposures occur with the worker in other positions. In the first phase of this work, updates on the computational phantom models were reviewed and a revised phantom model, which includes the updates for the relevant organs and compositions, was identified. This revised model was adopted as the starting point for this development work, and hence a series of radiation transport computations, using the Monte Carlo code MCNP5, was performed. The computational results were compared against values reported by the International Commission on Radiation Protection (ICRP) in Publication 74. For some of the organs (e.g., thyroid), there were discrepancies between the computed values and the results reported in ICRP-74. The reasons behind these discrepancies have been investigated and are discussed in this report.Additionally, sensitivity computations were performed to determine the sensitivity of the organ doses for certain parameters, including composition and cross sections used in the simulations. To assess the dose for more realistic exposure configurations, the phantom model was revised to enable flexible positioning of the arms and legs. Furthermore, to reduce the user time for analyses, a graphical user interface (GUI) was developed. The GUI can be used to visualize the positioning of the arms and legs as desired posture is achieved to generate the input file, invoke the computations, and extract the organ dose

  2. Genetics of Tinnitus: Time to Biobank Phantom Sounds

    Directory of Open Access Journals (Sweden)

    Christopher R. Cederroth

    2017-09-01

    Full Text Available Tinnitus is a common phantom sensation resulting most often from sensory deprivation, and for which little knowledge on the molecular mechanisms exists. While the existing evidence for a genetic influence on the condition has been until now sparse and underpowered, recent data suggest that specific forms of tinnitus have a strong genetic component revealing that not all tinnitus percepts are alike, at least in how they are genetically driven. These new findings pave the way for a better understanding on how phantom sensations are molecularly driven and call for international biobanking efforts.

  3. Avaliação do posicionamento da aorta em pacientes com escoliose idiopática do adolescente

    Directory of Open Access Journals (Sweden)

    Guilherme Augusto Foizer

    2013-01-01

    Full Text Available OBJETIVO: Avaliar o posicionamento da aorta em pacientes com escoliose. MÉTODOS: Foram realizados exames de imagem em pacientes ambulatoriais com escoliose idiopática do adolescente e em um grupo formado por pacientes hígidos, sendo analisados seis parâmetros: comprimento do corpo vertebral, largura, distância aorta-corpo, diâmetro da aorta, distância aorta-canal e ângulo corpo-aorta. RESULTADOS: As curvas variaram entre T3 e L2 com ângulos de Cobb de 46° e 114°. Pela classificação de Lenke os tipos 1AN e 1BN ocorreram em 20% dos casos, além de 1CN, 3BN, 3C+ com 13,3 % e 1B+, 3C- com 6,7 %. As vértebras próximas ao ápice da curva no grupo escoliose apresentam valores superiores às do grupo controle (em T8 com média de 86,93° no grupo escoliose e média 49,07 no grupo controle (p < 0,0001. CONCLUSÃO: Quanto mais próximo do ápice da deformidade, maior a póstero-lateralização da aorta.

  4. Estimation of prenatal aorta intima-media thickness from ultrasound examination

    Science.gov (United States)

    Veronese, E.; Tarroni, G.; Visentin, S.; Cosmi, E.; Linguraru, M. G.; Grisan, E.

    2014-10-01

    Prenatal events such as intrauterine growth restriction and increased cardiovascular risk in later life have been shown to be associated with an increased intima-media thickness (aIMT) of the abdominal aorta in the fetus. In order to assess and manage atherosclerosis and cardiovascular disease risk in adults and children, in recent years the measurement of abdominal and carotid artery thickness has gained a growing appeal. Nevertheless, no computer aided method has been proposed for the analysis of prenatal vessels from ultrasound data, yet. To date, these measurements are being performed manually on ultrasound fetal images by skilled practitioners. The aim of the presented study is to introduce an automatic algorithm that identifies abdominal aorta and estimates its diameter and aIMT from routine third trimester ultrasonographic fetal data. The algorithm locates the aorta, then segments it and, by modeling the arterial wall longitudinal sections by means of a gaussian mixture, derives a set of measures of the aorta diameter (aDiam) and of the intima-media thickness (aIMT). After estimating the cardiac cycle, the mean diameter and the aIMT at the end-diastole phase are computed. Considering the aIMT value for each subject, the correlation between automatic and manual end-diastolic aIMT measurements is 0.91 in a range of values 0.44-1.10 mm, corresponding to both normal and pathological conditions. The automatic system yields a mean relative error of 19%, that is similar to the intra-observer variability (14%) and much lower that the inter-observer variability (42%). The correlation between manual and automatic measurements and the small error confirm the ability of the proposed system to reliably estimate aIMT values in prenatal ultrasound sequences, reducing measurement variability and suggesting that it can be used for an automatic assessment of aIMT. Preliminary results have been presented in E Veronese, E Cosmi, S Visentin, E Grisan: 'Semiautomatic estimation

  5. Thrombopoietin contributes to the formation and the maintenance of hematopoietic progenitor-containing cell clusters in the aorta-gonad-mesonephros region.

    Science.gov (United States)

    Harada, Kaho; Nobuhisa, Ikuo; Anani, Maha; Saito, Kiyoka; Taga, Tetsuya

    2017-07-01

    In the midgestation mouse embryo, hematopoietic cell clusters containing hematopoietic stem/progenitor cells arise in the aorta-gonad-mesonephros (AGM) region. We have previously reported that forced expression of the Sox17 transcription factor in CD45lowc-Kithigh AGM cells, which are the hematopoietic cellular component of the cell clusters, and subsequent coculture with OP9 stromal cells in the presence of three cytokines, stem cell factor (SCF), interleukin-3 (IL-3), and thrombopoietin (TPO), led to the formation and the maintenance of cell clusters with cells at an undifferentiated state in vitro. In this study, we investigated the role of each cytokine in the formation of hematopoietic cell clusters. We cultured Sox17-transduced AGM cells with each of the 7 possible combinations of the three cytokines. The size and the number of Sox17-transduced cell clusters in the presence of TPO, either alone or in combination, were comparable to that observed with the complete set of the three cytokines. Expression of TPO receptor, c-Mpl was almost ubiquitously expressed and maintained in Sox17-transduced hematopoietic cell clusters. In addition, the expression level of c-Mpl was highest in the CD45lowc-Kithigh cells among the Sox17-transduced cell clusters. Moreover, c-Mpl protein was highly expressed in the intra-aortic hematopoietic cell clusters in comparison with endothelial cells of dorsal aorta. Finally, stimulation of the endothelial cells prepared from the AGM region by TPO induced the production of hematopoietic cells. These results suggest that TPO contributes to the formation and the maintenance of hematopoietic cell clusters in the AGM region. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Tratamento cirúrgico dos aneurismas toracoabdominais da aorta Surgical treatment of thoracoabdominal aortic aneurysms

    Directory of Open Access Journals (Sweden)

    Januário M Souza

    1991-04-01

    Full Text Available Foram operados, em nosso Serviço, 161 aneurismas da aorta, sendo 99 por dissecção e 62 por outras causas. Em cinco pacientes, os aneurismas eram de localização toracoabdominal, sendo três por degeneração aterosclerótica e dois por dissecção; três pacientes eram do sexo feminino e a idade variou de 31 a 71 anos. Dois pacientes submeteram-se a aneurismectomia previamente (um da aorta ascendente e outro da porção proximal da aorta torácica. Revascularização miocárdica foi feita em um paciente, 40 dias antes da aneurismectomia. A indicação em todos os pacientes foi dor, causada por compressão do aneurisma, sendo que, em dois, havia insuficiência respiratória associada. Todos os pacientes foram operados através de incisão toracoabdominal e abertura do diafragma. A aorta foi substituída por tubo de Dacron, desde sua porção proximal até sua bifurcação, e as artérias viscerais foram implantadas no tubo. Quatro pacientes foram operados com pinçamento da aorta; um paciente necessitou emprego de circulação extracorpórea e parada circulatória, por impossibilidade de pinçamento da aorta junto à artéria subclávia. Todos os pacientes sobreviveram ao ato cirúrgico, ocorrendo dois óbitos no pós-operatório, um subitamente no 12º dia e outro por coma neurológico secundário a parada cardíaca causada por hipoxia.Five patients have been operated on of thoracoabdominal aortic aneurysms. The mean age was 53 years (range 31-71 and three were women. All the patients were symptomatic, three of them had arteriosclerotic aneurysms, and the other two had dissecting aneurysms. Three patients had been operated on previously. The exposure of aneurysm was made through a thoracoabdominal incision, in four patients clamps were placed above and below the aneurysm and it was incised longitudinally. Bypass between left atrium and left femoral artery with hypothermia and circulatory arrest was used in the other patients, since the

  7. Monte Carlo Evaluation of Gamma Knife Dose Profile in Real Brain Phantom

    Directory of Open Access Journals (Sweden)

    Ali Aghaebrahimian

    2016-03-01

    The calculation of the real phantom showed that water and polystyrene could function similarly, while evaluating dosimetry parameters in the Gamma Knife system; thus, water and polystyrene are not appropriate phantom matters for this purpose.

  8. Design and development of a telerehabilitation platform for patients with phantom limb pain

    NARCIS (Netherlands)

    Andreas Rothgangel; Susy Braun; Rob Smeets; Anna Beurskens

    2017-01-01

    Background: Phantom limb pain is a frequent and persistent problem following amputation. Achieving sustainable favorable effects on phantom limb pain requires therapeutic interventions such as mirror therapy that target maladaptive neuroplastic changes in the central nervous system. Unfortunately,

  9. Human torso phantom for imaging of heart with realistic modes of cardiac and respiratory motion

    Science.gov (United States)

    Boutchko, Rostyslav; Balakrishnan, Karthikayan; Gullberg, Grant T; O& #x27; Neil, James P

    2013-09-17

    A human torso phantom and its construction, wherein the phantom mimics respiratory and cardiac cycles in a human allowing acquisition of medical imaging data under conditions simulating patient cardiac and respiratory motion.

  10. Computerized quantitative evaluation of mammographic accreditation phantom images

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yongbum; Tsai, Du-Yih; Shinohara, Norimitsu [Department of Radiological Technology, School of Health Sciences, Niigata University, 2-746 Asahimachidori, Chuouku, Niigata 951-8518 (Japan); Department of Radiological Technology, Gifu Univesity of Medical Science, 1-795 Hiraga-aza-nagamine, Seki, Gifu 501-3892 (Japan)

    2010-12-15

    Purpose: The objective was to develop and investigate an automated scoring scheme of the American College of Radiology (ACR) mammographic accreditation phantom (RMI 156, Middleton, WI) images. Methods: The developed method consisted of background subtraction, determination of region of interest, classification of fiber and mass objects by Mahalanobis distance, detection of specks by template matching, and rule-based scoring. Fifty-one phantom images were collected from 51 facilities for this study (one facility provided one image). A medical physicist and two radiologic technologists also scored the images. The human and computerized scores were compared. Results: In terms of meeting the ACR's criteria, the accuracies of the developed method for computerized evaluation of fiber, mass, and speck were 90%, 80%, and 98%, respectively. Contingency table analysis revealed significant association between observer and computer scores for microcalcifications (p<5%) but not for masses and fibers. Conclusions: The developed method may achieve a stable assessment of visibility for test objects in mammographic accreditation phantom image in whether the phantom image meets the ACR's criteria in the evaluation test, although there is room left for improvement in the approach for fiber and mass objects.

  11. The perception of phantom limbs. The D. O. Hebb lecture.

    Science.gov (United States)

    Ramachandran, V S; Hirstein, W

    1998-09-01

    Almost everyone who has a limb amputated will experience a phantom limb--the vivid impression that the limb is not only still present, but in some cases, painful. There is now a wealth of empirical evidence demonstrating changes in cortical topography in primates following deafferentation or amputation, and this review will attempt to relate these in a systematic way to the clinical phenomenology of phantom limbs. With the advent of non-invasive imaging techniques such as MEG (magnetoencephalogram) and functional MRI, topographical reorganization can also be demonstrated in humans, so that it is now possible to track perceptual changes and changes in cortical topography in individual patients. We suggest, therefore, that these patients provide a valuable opportunity not only for exploring neural plasticity in the adult human brain but also for understanding the relationship between the activity of sensory neurons and conscious experience. We conclude with a theory of phantom limbs, some striking demonstrations of phantoms induced in normal subjects, and some remarks about the relevance of these phenomena to the question of how the brain constructs a 'body image.'

  12. [Evaluation of ultrasound hyperthermia system with a phantom model].

    Science.gov (United States)

    Ono, S; Hirose, T; Shiba, T; Kuriya, K; Watanabe, K

    1996-03-01

    Ultrasound (US) hyperthermia is a local heating method that has recently been introduced into clinical practice. A prototype and modified version of this system using a phantom model (agar with bone inserted) were evaluated. The prototype system consists of a power delivery unit (0.5 MHz frequency) with a circulating cooled water bolus. This system heats a shallow area irrespective of power output, but has a tendency to overheat the phantom surface. We incorporated three modifications into the prototype. The modified type has three frequency applicators (0.5, 1.0, 1.5MHz) and a secondary bolus. Aluminum-urethane shields were used to cover the phantom surface located over bone preventing overheating of bone. By changing the applicator's US frequency, we could change the depth of the heating area. Overheating of the phantom surface and bone thus was avoided. These results suggest that our modified US hyperthermia system with multiple frequency applicators, a secondary bolus and aluminum-urethane shields provided a good heating pattern.

  13. Anisotropic Bianchi-I universe with phantom field and cosmological ...

    Indian Academy of Sciences (India)

    of the cosmological solutions. Keywords. Anisotropic cosmology; phantom field; accelerating universe. PACS Nos 04.20.Jb; 98.80.Cq. 1. Introduction. Recent astrophysical data obtained from high redshift surveys of Supernovae,. COBE to WMAP predict that the present universe is passing through an accel- erating phase of ...

  14. Measuring Phantom Recollection in the Simplified Conjoint Recognition Paradigm

    Science.gov (United States)

    Stahl, Christoph; Klauer, Karl Christoph

    2009-01-01

    False memories are sometimes strong enough to elicit recollective experiences. This phenomenon has been termed Phantom Recollection (PR). The Conjoint Recognition (CR) paradigm has been used to empirically separate PR from other memory processes. Recently, a simplification of the CR procedure has been proposed. We herein extend the simplified CR…

  15. Comparative attenuation spectra of liquid skin-like phantoms

    CSIR Research Space (South Africa)

    Singh, A

    2010-09-01

    Full Text Available This study aims to extract and compare attenuation coefficients of different liquid skin-like phantoms representing Skin Types 1 to V1 with two methods, Spectrophotometric and Integrating Sphere methods. The correlation between the results of the 2...

  16. Cosmological model of interacting phantom and Yang–Mills fields

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... In this paper, we consider a model of interacting phantom and Yang–Mills (YM) fields by assuming dilaton-type coupling. Using the specific solution for YM equation previously found by the author, we obtain simple exact solutions for the accelerated expansion of the Friedmann–Robertson–Walker (FRW) ...

  17. Home based Tactile Discrimination Training (TDT) reduces phantom limb pain.

    Science.gov (United States)

    Wakolbinger, Robert; Diers, Martin; Hruby, Laura A; Sturma, Agnes; Aszmann, Oskar C

    2017-11-06

    Phantom limb pain (PLP) affects a high percentage of amputees. Since treatment options are limited, low quality of life and addiction to pain medication is frequent. New attempts, such as mirror therapy or electrical sensory discrimination training, make use of the brain's plasticity to alleviate this centrally derived pain. This pilot study assessed the question, whether home-based tactile discrimination training (TDT) leads to a stronger decrease in phantom limb pain levels, compared to a standard massage treatment. Controlled study. Outpatient. Amputees (upper/lower extremity) with PLP of VAS 4/10 or higher. Eight patients participated in the study. The treatment phase comprised two weeks (15min daily). Subjects were examined at baseline, after treatment, two weeks after and four weeks after completing the treatment. Pain was assessed with the West Haven Multidimensional Pain Inventory. There was a significantly stronger reduction in phantom limb pain in the treatment group receiving TDT. Phantom limb pain intensity ratings were significantly reduced at the end of therapy, two weeks after as well as four weeks after compared to pre-treatment. TDT seems to be an easy, cheap, time-effective and safe method to achieve sustained alleviation in PLP and also brings about a positive change in body image. Home-based TDT could achieve sustained reduction in PLP and should be considered as possible alternative to established treatment methods. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  18. Uniqueness of higher-dimensional phantom field wormholes

    Science.gov (United States)

    Rogatko, Marek

    2018-01-01

    Based on the rigid positive energy theorem we proved the uniqueness of static spherically symmetric traversable wormholes with two asymptotically flat ends, being the higher-dimensional solutions of Einstein scalar phantom field. The proof is valid under the auxiliary condition imposed on wormhole mass and scalar charge.

  19. Temperature distributions obtained with diathermy electrodes implanted into a phantom.

    Science.gov (United States)

    Wasserman, H J; Levin, W

    1979-11-01

    Uniform patterns of heating in a homogeneous phantom were obtained by implanting shortwave diathermy electrodes in a particular configuration. The methods of heating and measurement are described. The technique can be considered for applying localized hyperthermia in the treatment of cancer.

  20. THE EFFECT OF PHANTOM GROUPS ON GENETIC TREND

    African Journals Online (AJOL)

    Helena Theron

    the South African Holstein population. EBV – estimated breeding value. The DYD test of Boichard et al. (1995) indicated a significant underestimation in the genetic trend when phantom parent groups were not included in the model. The values of 01*σg for milk, butterfat and protein were 5.97, 0.20 and 0.17 respectively.

  1. AdS Black Hole with Phantom Scalar Field

    Directory of Open Access Journals (Sweden)

    Limei Zhang

    2017-01-01

    Full Text Available We present an AdS black hole solution with Ricci flat horizon in Einstein-phantom scalar theory. The phantom scalar fields just depend on the transverse coordinates x and y, which are parameterized by the parameter α. We study the thermodynamics of the AdS phantom black hole. Although its horizon is a Ricci flat Euclidean space, we find that the thermodynamical properties of the black hole solution are qualitatively the same as those of AdS Schwarzschild black hole. Namely, there exists a minimal temperature and the large black hole is thermodynamically stable, while the smaller one is unstable, so there is a so-called Hawking-Page phase transition between the large black hole and the thermal gas solution in the AdS space-time in Poincare coordinates. We also calculate the entanglement entropy for a strip geometry dual to the AdS phantom black holes and find that the behavior of the entanglement entropy is qualitatively the same as that of the black hole thermodynamical entropy.

  2. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited

    NARCIS (Netherlands)

    Xia, W.; Piras, D.; Heijblom, M.; Steenbergen, Wiendelt; van Leeuwen, Ton; Manohar, Srirang

    2011-01-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F–T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where

  3. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited.

    Science.gov (United States)

    Xia, Wenfeng; Piras, Daniele; Heijblom, Michelle; Steenbergen, Wiendelt; van Leeuwen, Ton G; Manohar, Srirang

    2011-07-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where temperature distributions during F-T are relatively homogeneous. In this work, in breast-sized samples we observed substantial temperature differences between the shallow regions and the interior during the F-T procedure. We investigated whether spatial variations were also present in the acoustic and optical properties. The speed of sound, acoustic attenuation, and optical reduced scattering coefficients were measured on specimens sampled at various locations in a large phantom. In general, the properties matched values quoted for breast tissue. But while acoustic properties were relatively homogeneous, the reduced scattering was substantially different at the surface compared with the interior. We correlated these variations with gel microstructure inspected using scanning electron microscopy. Interestingly, the phantom's reduced scattering spatial distribution matches the optical properties of the standard two-layer breast model used in x ray dosimetry. We conclude that large PVA samples prepared using the standard recipe make excellent breast tissue phantoms.

  4. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited

    Science.gov (United States)

    Xia, Wenfeng; Piras, Daniele; Heijblom, Michelle; Steenbergen, Wiendelt; van Leeuwen, Ton G.; Manohar, Srirang

    2011-07-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where temperature distributions during F-T are relatively homogeneous. In this work, in breast-sized samples we observed substantial temperature differences between the shallow regions and the interior during the F-T procedure. We investigated whether spatial variations were also present in the acoustic and optical properties. The speed of sound, acoustic attenuation, and optical reduced scattering coefficients were measured on specimens sampled at various locations in a large phantom. In general, the properties matched values quoted for breast tissue. But while acoustic properties were relatively homogeneous, the reduced scattering was substantially different at the surface compared with the interior. We correlated these variations with gel microstructure inspected using scanning electron microscopy. Interestingly, the phantom's reduced scattering spatial distribution matches the optical properties of the standard two-layer breast model used in x ray dosimetry. We conclude that large PVA samples prepared using the standard recipe make excellent breast tissue phantoms.

  5. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited

    NARCIS (Netherlands)

    Xia, Wenfeng; Piras, Daniele; Heijblom, Michelle; Steenbergen, Wiendelt; van Leeuwen, Ton G.; Manohar, Srirang

    2011-01-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where

  6. Accurately characterized optical tissue phantoms: how, why and when?

    Science.gov (United States)

    Bouchard, Jean-Pierre; Veilleux, Isra"l.; Noiseux, Isabelle; Mermut, Ozzy

    2011-03-01

    Optical tissue phantoms are very important tools for the development of biomedical imaging applications. Optical phantoms are often used as ground truth against which instruments results can be compared. It is therefore important that the optical properties of reference phantoms be measured in a manner that is traceable to the international system of units. SI traceability insures long term consistency of results and will therefore improve the effectiveness of diffuse optics research effort more effective by reducing unwanted variability in the data produced and shared by the community. The ultimate benefit of rigorous SI traceability is the reduction of variability in the data produced by novel diagnostic devices, which will in turn increase the statistical power of clinical trials aiming at validating their clinical usefulness. SI traceability, and therefore uncertainty analysis, is also relevant to traceability aspects mandated by FDA regulations. SI traceability is achieved through a thorough analysis of the measurement principle and its potential error sources. The uncertainty analysis should be ultimately validated by inter-laboratory comparison until a consensus is attained on the best practices for measuring the optical properties of tissue phantoms.

  7. A computational phantom of head and neck - SISCODES

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Trindade, Bruno Machado; Campos, Tarcisio Passos Ribeiro [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares]. E-mail: larissa.thompson@ig.com.br; bmtrindade@yahoo.com; campos@nuclear.ufmg.br

    2007-07-01

    A computational voxel model of a head and neck adult male was built through the SISCODES code, in order to complement and to optimize the radiotherapic treatment in head and neck cancer, in terms of dosimetric evaluation and prediction. This computational simulator object, namely computational phantom, is a useful tool for the elaboration and simulation of the three-dimensional radiation planning. The present phantom was assembled based on information generated by photographic images of the visible human project. The images were digitalized and converted one by one to a matrix of voxel, in which tissues and its respective chemical composition were identified, with the helping of a biomedical and nuclear data bank including in SISCODES. A computational simulation of an external beam mimicking a Co-60 irradiator was prepared, reproducing a radiation window equivalent to one found in a lateral irradiation of a nasopharyngeal tumour in situ. Absorbed dose evaluation in the internal regions of the phantom are presented and demonstrated through spatial dose distribution, superimposed with the 2D phantom sections. The present article illustrates the possibility of generating information of the spatial dose distribution including all adjacent tissues, far from tumour, improving the radiodosimetry and creating the possibility of investigating neurological deficits, dysphagia, and speaking and hearing alterations, non evaluated in the present stage of radiation therapy of head and neck. (author)

  8. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Luxemburgo Hospital, Mario Penna Institute, Belo Horizonte, MG (Brazil)

    2015-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  9. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Minas Gerais, MG (Brazil). Dept. de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Instituto Mario Penna, Minas Gerais, MG (Brazil). Hospital Luxemburgo

    2013-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  10. Gravitational Quasinormal Modes of Regular Phantom Black Hole

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    Jin Li

    2017-01-01

    Full Text Available We investigate the gravitational quasinormal modes (QNMs for a type of regular black hole (BH known as phantom BH, which is a static self-gravitating solution of a minimally coupled phantom scalar field with a potential. The studies are carried out for three different spacetimes: asymptotically flat, de Sitter (dS, and anti-de Sitter (AdS. In order to consider the standard odd parity and even parity of gravitational perturbations, the corresponding master equations are derived. The QNMs are discussed by evaluating the temporal evolution of the perturbation field which, in turn, provides direct information on the stability of BH spacetime. It is found that in asymptotically flat, dS, and AdS spacetimes the gravitational perturbations have similar characteristics for both odd and even parities. The decay rate of perturbation is strongly dependent on the scale parameter b, which measures the coupling strength between phantom scalar field and the gravity. Furthermore, through the analysis of Hawking radiation, it is shown that the thermodynamics of such regular phantom BH is also influenced by b. The obtained results might shed some light on the quantum interpretation of QNM perturbation.

  11. Tratamento cirúrgico da coarctação de aorta pela aortoplastia trapezoidal Surgical treatment of coarctation of the aorta using trapezoidal aortoplasty

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    Jarbas Jakson Dinkhuysen

    2004-01-01

    Full Text Available OBJETIVO: A aortoplastia trapezoidal é uma variante técnica da anastomose término-terminal que, amparada em elementos da geometria, objetiva aumentar o diâmetro da aorta ao nível da sutura reduzida e, consequentemente, a manutenção de gradientes pressóricos residuais ou recorrentes indesejáveis a curto e a longo prazo. MÉTODOS: Após a ressecção da área coarctada e tecido ductal, são confeccionados em cada coto aórtico 3 trapezóides que, ao serem confrontados, criam linha de sutura com aspecto sinusoidal (zigue-zague. Foram operados por esta técnica 33 pacientes, a maioria homens, com idades variando de 3 meses a 36 anos (m 9,5 ± 9,7. RESULTADOS: Não ocorreu mortalidade imediata ou tardia e o tempo de evolução a longo prazo foi de 1,1 a 7,6 anos (m 3,6 ± 3,4. A maioria dos pacientes ficou assintomática com níveis normais de pressão arterial, possibilitando a descontinuação da terapêutica antihipertensiva (pOBJECTIVE: Trapezoidal aortoplasty is a technical variant of end-to-end anastomosis, which, based on elements of geometry, aims at increasing the diameter of the aorta at the level of the suture, therefore reducing the occurrence of residual or recurrent pressure gradients in the short and long run. METHODS: After resecting the coarcted area and ductal tissue, 3 trapezoids are confected in each aortic stump, which, when confronted, create a suture line with a sinusoidal aspect (zigzag. Thirty-three patients underwent surgery with this technique, 22 (66.7% males, with ages ranging from 3 months to 36 years (mean of 9.84 ± 9.69. RESULTS: No immediate or late deaths occurred. Follow-up ranged from 1.1 to 7.6 years (mean of 3.6 ± 3.4. Most patients became asymptomatic with normal blood pressure levels, enabling the discontinuation of antihypertensive therapy (P<0.0001. A significant reduction in the pressure gradients was observed on Doppler echocardiography and during cardiac catheterization (P<0.001. The analysis of

  12. Aortoscopia no tratamento das dissecções agudas da aorta Aortoscopy in the treatment of acute dissecting aneurysms of the aorta

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    Gladyston SOUTO

    1999-07-01

    Full Text Available No período de janeiro a dezembro de 1998 , foram operados 10 pacientes portadores de dissecção aguda da aorta (DA Ao 4 do tipo A e 6 do tipo B. O sexo masculino predominou e a idade dos pacientes variou de 34 a 78 anos. Em todos foram realizadas aortoscopias usando hipotermia profunda com parada circulatória total. Usou-se um gastroscópio, obtendo visão do lume da Ao, sendo que todos os pacientes tinham menos que 15 dias da doença. No tipo A, havia re-entrada abaixo da subclávia esquerda em 2 pacientes e, nos outros 2, na bifurcação das ilíacas. No tipo B, havia re-entrada ao nível das renais em 2 pacientes e, ao nível da bifurcação da Ao e das ilíacas, em 4. Em 2 pacientes do tipo A, a aortoscopia orientou na colocação de uma "Tromba de Elefante" como complemento. Nos outros 2, orientou na inversão do sentido da linha arterial. No tipo B, orientou na perfeita colocação da "Tromba de Elefante" e, em 4 pacientes, utilizamos a aortoscopia como complemento diagnóstico. O tempo utilizado na aortoscopia não alterou a morbimortalidade. Podemos concluir que a aortoscopia é um método de diagnóstico rápido, com boa definição das alterações anatômicas da Ao, permitindo um tratamento efetivo. Nos casos agudos instáveis podemos dispensar alguns exames pré-operatórios para não retardarmos a operação. O diagnóstico da re-entrada nos seguimentos inferiores da Ao ajuda a evitar a dissecção retrógrada. Acreditamos que a aortoscopia poderá, no futuro, ser de grande ajuda no diagnóstico e tratamento das DA Ao, bem como de outras lesões da Ao.From January to December 1998, ten patients with dissecting aneurysms of the Aorta (ADA Ao were operated on, 4 type A and 6 type B. Males predominated and ages ranged from 34 to 78 years. In all of them aortoscopy was performed with deep hypothermia and circulatory arrest. A gastroscope was used with visualization of the aortic lumen and all patients had less than 15 days of disease

  13. Tissue-Like Phantoms as a Platform for Inserted Fluorescence Nano-Probes

    OpenAIRE

    Nayhoz, Tsviya; Barnoy, Eran A.; Fixler, Dror

    2016-01-01

    Tissue-like phantoms are widely used as a model for mimicking the optical properties of live tissue. This paper presents the results of a diffusion reflection method and fluorescence lifetime imaging microscopy measurements of fluorescein-conjugated gold nanorods in solution, as well as inserted in solid tissue-imitating phantoms. A lack of consistency between the fluorescence lifetime results of the solutions and the phantoms raises a question about the ability of tissue-like phantoms to mai...

  14. NEMA image quality phantom measurements and attenuation correction in integrated PET/MR hybrid imaging.

    Science.gov (United States)

    Ziegler, Susanne; Jakoby, Bjoern W; Braun, Harald; Paulus, Daniel H; Quick, Harald H

    2015-12-01

    In integrated PET/MR hybrid imaging the evaluation of PET performance characteristics according to the NEMA standard NU 2-2007 is challenging because of incomplete MR-based attenuation correction (AC) for phantom imaging. In this study, a strategy for CT-based AC of the NEMA image quality (IQ) phantom is assessed. The method is systematically evaluated in NEMA IQ phantom measurements on an integrated PET/MR system. NEMA IQ measurements were performed on the integrated 3.0 Tesla PET/MR hybrid system (Biograph mMR, Siemens Healthcare). AC of the NEMA IQ phantom was realized by an MR-based and by a CT-based method. The suggested CT-based AC uses a template μ-map of the NEMA IQ phantom and a phantom holder for exact repositioning of the phantom on the systems patient table. The PET image quality parameters contrast recovery, background variability, and signal-to-noise ratio (SNR) were determined and compared for both phantom AC methods. Reconstruction parameters of an iterative 3D OP-OSEM reconstruction were optimized for highest lesion SNR in NEMA IQ phantom imaging. Using a CT-based NEMA IQ phantom μ-map on the PET/MR system is straightforward and allowed performing accurate NEMA IQ measurements on the hybrid system. MR-based AC was determined to be insufficient for PET quantification in the tested NEMA IQ phantom because only photon attenuation caused by the MR-visible phantom filling but not the phantom housing is considered. Using the suggested CT-based AC, the highest SNR in this phantom experiment for small lesions (PET/MR hybrid system. The superiority of CT-based AC for this phantom is demonstrated by comparison to measurements using MR-based AC. Furthermore, optimized PET image reconstruction parameters are provided for the highest lesion SNR in NEMA IQ phantom measurements.

  15. Use of Calcitonin in Recalcitrant Phantom Limb Pain Complicated by Heterotopic Ossification

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    Ricardo Viana

    2015-01-01

    Full Text Available A common complication following amputation is phantom sensation, which may include experiencing pain in the phantom limb. This study details the management of phantom limb pain in a 72-year-old man, in whom comorbid heterotopic ossification was present. In addition, the authors provide a review of the literature regarding phantom limb pain management, and summarize the current understanding of heterotopic ossification and its possible link to peripheral nerve injury.

  16. Glass-Fiber-based MR-safe Guidewire for MR Imaging-guided Endovascular Interventions: In Vitro and Preclinical in Vivo Feasibility Study.

    Science.gov (United States)

    Massmann, Alexander; Buecker, Arno; Schneider, Guenther K

    2017-08-01

    Purpose To evaluate glass-fiber-based guidewires that are safe for magnetic resonance (MR) imaging-guided endovascular interventions by using a phantom and an in vivo swine model. Materials and Methods MR imaging-safe guidewires were made from micropultruded glass and/or aramid fibers and epoxy resin with diameters of 0.89 mm (0.035 inch) for standard and stiff guidewires and 0.36 mm (0.014 inch) for micro guidewires. MR imaging visibility and mechanical properties were assessed in a pulsatile flow model. After approval was obtained from the institutional animal care and use committee, MR imaging guidewires were evaluated for standard endovascular procedures in nine pigs. Real-time steady-state free-precession sequences were used for MR imaging-guided catheterization, balloon dilation, and stent implantation into aorto-iliac/visceral arteries and the vena cava (temporal resolution, five images per second; and spatial resolution, 150-mm field of view, and 128 × 128 matrix) with a 1.5-T clinical imager. Visualization with the guidewires was rated on a four-point scale, handling was rated on a three-point scale, and catheterization times for different vessel regions were determined by two interventional radiologists. Afterward, handling ratings and catheterization times were obtained for standard nitinol guidewires during x-ray-based fluoroscopy. Cannulation times, signal intensity in each vessel region, and visualization and handling ratings were measured for the MR imaging guidewires. Bland-Altman analysis was performed for inter- and intraobserver variability of cannulation time. Spearman rank correlation was used to compare handling of MR imaging guidewires and standard nitinol guidewires. Results MR imaging guidewires were characterized by good to excellent visibility, with a continuous artifact of 2 mm in diameter and 4 × 8-mm ball-shaped tip marker. Stiffness, flexibility, and guidance reflected comparable times for all in vitro and in vivo procedures with

  17. "Imprisoned" in pain: analyzing personal experiences of phantom pain.

    Science.gov (United States)

    Nortvedt, Finn; Engelsrud, Gunn

    2014-11-01

    This article explores the phenomenon of "phantom pain." The analysis is based on personal experiences elicited from individuals who have lost a limb or live with a paralyzed body part. Our study reveals that the ways in which these individuals express their pain experience is an integral aspect of that experience. The material consists of interviews undertaken with men who are living with phantom pain resulting from a traumatic injury. The phenomenological analysis is inspired by Zahavi (J Conscious Stud 8(5-7):151-167, 2001) and Merleau-Ponty (Phenomenology of perception. Routledge and Kegan Paul, London, 1962/2000). On a descriptive level the metaphors these patients invoke to describe their condition reveal immense suffering, such as a feeling of being invaded by insects or of their skin being scorched and stripped from their body. Such metaphors express a dimension of experience concerning the self that is in pain and others whom the sufferer relates to through this pain, as well as the agony that this pain inflicts in the world of lived experience. This pain has had a profound impact on their lives and altered their relationship with self (body), others and the world. Their phantom pain has become a reminder of their formerly intact and functioning body; they describe the contrast between their past and present body as an ambiguous and disturbing experience. We conclude that these sensitive and personalized experiences of phantom pain illuminates how acts of expression--spoken pain--constitute a fundamental dimension of a first-person perspective which contribute to the field of knowledge about "phantom pain".

  18. MRI characteristics for "phantom" scratching in canine syringomyelia.

    Science.gov (United States)

    Nalborczyk, Zoe R; McFadyen, Angus K; Jovanovik, Jelena; Tauro, Anna; Driver, Colin J; Fitzpatrick, Noel; Knower, Susan P; Rusbridge, Clare

    2017-11-16

    A classic sign of canine syringomyelia (SM) is scratching towards one shoulder. Using magnetic resonance imaging (MRI) we investigate the spinal cord lesion relating to this phenomenon which has characteristics similar to fictive scratch secondary to spinal cord transection. Medical records were searched for Cavalier King Charles spaniels with a clinical and MRI diagnosis of symptomatic SM associated with Chiari-like malformation (CM). The cohort was divided into SM with phantom scratching (19 dogs) and SM but no phantom scratching (18 dogs). MRI files were anonymised, randomised and viewed in EFILM ™. For each transverse image, the maximum perpendicular dimensions of the syrinx in the dorsal spinal cord quadrants were determined. Visual assessment was made as to whether the syrinx extended to the superficial dorsal horn (SDH). We showed that phantom scratching appears associated with a large dorsolateral syrinx that extends to the SDH in the C3-C6 spinal cord segments (corresponding to C2-C5 vertebrae). Estimated dorsal quadrant syrinx sizes based on the perpendicular diameters were between 2.5 and 9.5 times larger in dogs with phantom scratching, with the largest mean difference p-value being 0.009. SM associated phantom scratching appears associated with MRI findings of a large syrinx extending into the mid cervical SDH. We hypothesise that damage in this region might influence the lumbosacral scratching central pattern generator (CPG). If a scratching SM affected dog does not have a large dorsolateral cervical syrinx with SDH involvement then alternative explanations for scratching should be investigated.

  19. Posttraumatic syringomyelia: volumetric phantom and patient studies using MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Michael; Habicht, Dirk; Kalvine, Kira; Sartor, Klaus [Department of Neuroradiology, Medical School, University of Heidelberg (Germany); Aschoff, Alfred [Department of Neurosurgery, Medical School, University of Heidelberg (Germany)

    2002-12-01

    The purpose of this study was to determine the volume of posttraumatic syringomyelia (PTS) based on standard MRI data acquisitions, and to compare the volumes with the neurological deficits of the patients. Firstly, phantom studies were performed using routine T1- (T1W; TR 500 ms, TE 13 ms) spin-echo (SE) images, 3D gradient-echo (GE) images and T2-weighted (T2W) turbo spin-echo (TSE) images (TR 3000 ms, TE 130 ms), in the sagittal plane. The slices were interleaved so that there was no gap. Twelve phantoms simulating a PTS were constructed and filled with fluid. Each volume was exactly measured immediately prior to filling (volumes: 3600-74,000 mm{sup 3}, mean 27,500 mm{sup 3}). In the clinical study 32 patients with PTS were examined using the same protocol. Patients were supine and a phased-array coil was used. The phantom studies revealed measurement errors of within 35%. There were problems defining the boundaries in the small and irregular phantoms as well as in small and irregular PTS, and due to the partial-volume averaging effect. The two small irregular phantoms could only be measured on the axial images. The T2W images in the axial plane showed the best results: measurement accuracy 92%. In the clinical study all examinations were technically successful. The volumes of the PTS ranged between 200 and 19,800 mm{sup 3}; the mean volume was 4075 mm{sup 3}. Our initial results show that the volume measurement of a PTS using standard MRI sequences can help generate more objective and accurate measures of spinal cord lesions, and this may enhance the sensitivity of MRI in detecting disease progression or regression after treatment. (orig.)

  20. Internal dosimetry estimates using voxelized reference phantoms for thyroid agents.

    Science.gov (United States)

    Hoseinian-Azghadi, E; Rafat-Motavalli, L; Miri-Hakimabad, H

    2014-05-01

    This work presents internal dosimetry estimates for diagnostic procedures performed for thyroid disorders by relevant radiopharmaceuticals. The organ doses for (131)Iodine, (123)Iodine and (99m)Tc incorporated into the body were calculated for the International Commission on Radiological Protection (ICRP) reference voxel phantoms using the Monte Carlo transport method. A comparison between different thyroid uptakes of iodine in the range of 0-55% was made, and the effect of various techniques for administration of (99m)Tc on organ doses was studied. To investigate the necessity of calculating organ dose from all source regions, the major source organ and its contribution to total dose were specified for each target organ. Moreover, we compared effective dose in ICRP voxel phantoms with that in stylized phantoms. In our method, we directly calculated the organ dose without using the S values or SAFs, as is commonly done. Hence, a distribution of the absorbed dose to entire tissues was obtained. The chord length distributions (CLDs) were also computed for the selected source-target pairs to make comparison across the genders. The results showed that the S values for radionuclides in the thyroid are not sufficient for calculating the organ doses, especially for (123)I and (99m)Tc. The thyroid and its neighboring organs receive a greater dose as thyroid uptake increases. Our comparisons also revealed an underestimation of organ doses reported for the stylized phantoms compared with the values based on the ICRP voxel phantoms in the uptake range of 5-55%, and an overestimation of absorbed dose by up to 2-fold for Iodine administration using blocking agent and for (99m)Tc incorporation.