Understanding the heterogeneity in volume overload and fluid distribution in decompensated heart failure is key to optimal volume management: role for blood volume quantitation.

Science.gov (United States)

Miller, Wayne L; Mullan, Brian P

2014-06-01

This study sought to quantitate total blood volume (TBV) in patients hospitalized for decompensated chronic heart failure (DCHF) and to determine the extent of volume overload, and the magnitude and distribution of blood volume and body water changes following diuretic therapy. The accurate assessment and management of volume overload in patients with DCHF remains problematic. TBV was measured by a radiolabeled-albumin dilution technique with intravascular volume, pre-to-post-diuretic therapy, evaluated at hospital admission and at discharge. Change in body weight in relation to quantitated TBV was used to determine interstitial volume contribution to total fluid loss. Twenty-six patients were prospectively evaluated. Two patients had normal TBV at admission. Twenty-four patients were hypervolemic with TBV (7.4 ± 1.6 liters) increased by +39 ± 22% (range, +9.5% to +107%) above the expected normal volume. With diuresis, TBV decreased marginally (+30 ± 16%). Body weight declined by 6.9 ± 5.2 kg, and fluid intake/fluid output was a net negative 8.4 ± 5.2 liters. Interstitial compartment fluid loss was calculated at 6.2 ± 4.0 liters, accounting for 85 ± 15% of the total fluid reduction. TBV analysis demonstrated a wide range in the extent of intravascular overload. Dismissal measurements revealed marginally reduced intravascular volume post-diuretic therapy despite large reductions in body weight. Mobilization of interstitial fluid to the intravascular compartment with diuresis accounted for this disparity. Intravascular volume, however, remained increased at dismissal. The extent, composition, and distribution of volume overload are highly variable in DCHF, and this variability needs to be taken into account in the approach to individualized therapy. TBV quantitation, particularly serial measurements, can facilitate informed volume management with respect to a goal of treating to euvolemia. Copyright © 2014 American College of Cardiology Foundation. Published

Model for the radionuclide measurement of ascitic fluid volumes

International Nuclear Information System (INIS)

Kaplan, W.D.; Davis, M.A.; Uren, R.F.; Wisotsky, T.; LaTegola, M.

1978-01-01

Technetium-99m phytate colloids formed in vitro and in vivo were examined as radioindicators for estimation of the volume of third-space fluid in an ovarian ascites model using C3HeB/FeJ mice. In double-label experiments, the accuracy of the colloids for dilution analysis was found to be equal or superior to that of I-125 HSA. Sampling times 3 to 5 min after intraperitoneal administration were found to produce the best volume estimates. Four needle-stopcock assemblies inserted sequentially into the quadrants of the peritoneal cavity were used for administration and sampling of the radioindicators. The stopcocks could be closed to prevent leakage of ascitic fluid during the procedure. In contrast to radiolabeled albumin, Tc-99m phytate colloids have clinical use for simultaneous imaging of radiotracer migration to assess potential occlusion of diaphragmatic lymphatics by neoplastic cells, and for dilution analysis to estimate volume of ascitic fluid

Variant of a volume-of-fluid method for surface tension-dominant two ...

Indian Academy of Sciences (India)

2013-12-27

Dec 27, 2013 ... face tension-dominant two-phase flows are explained. ... for one particular fluid inside a cell as its material volume divided by the total ... the reconstructed interface and the velocity field, and the final part ..... Welch S W J and Wilson J 2000 A volume of fluid based method for fluid flows with phase change. J.

Volume measurement of multiple sclerosis lesions with magnetic resonance images

International Nuclear Information System (INIS)

Wicks, D.A.G.; Tofts, P.S.; Miller, D.H.; Du Boulay, G.H.; Feinstein, A.; Harvey, I.; Brenner, R.; McDonald, W.I.; Sacares, R.P.

1992-01-01

The ability to visualise multiple sclerosis lesions in vivo with magnetic resonance imaging suggests an important role in monitoring the course of the disease. In order to help the long-term assessment of prospective treatments, a semi-automated technique for measuring lesion volume has been developed to provide a quantitative index of disease progression. Results are presented from a preliminary study with a single patient and compared to measurements taken from lesion outlines traced by a neuroradiologist, two neurologists and a technician. The semi-automated technique achieved a precision of 6% compared to a range of 12-33% for the manual tracing method. It also reduced the human interaction time from at least 60 min to 15 min. (orig.)

Mechanisms controlling the volume of pleural fluid and extravascular lung water

Directory of Open Access Journals (Sweden)

G. Miserocchi

2009-12-01

Full Text Available Pleural and interstitial lung fluid volumes are strictly controlled and maintained at the minimum thanks to the ability of lymphatics to match the increase in filtration rate. In the pleural cavity, fluid accumulation is easily accommodated by retraction of lung and chest wall (high compliance of the pleural space; the increase of lymph flow per unit increase in pleural fluid volume is high due to the great extension of the parietal lymphatic. However, for the lung interstitium, the increase in lymph flow to match increased filtration does not need to be so great. In fact, increased filtration only causes a minor increase in extravascular water volume (<10% due to a marked increase in interstitial pulmonary pressure (low compliance of the extracellular matrix which, in turn, buffers further filtration. Accordingly, a less extended lymphatic network is needed. The efficiency of lymphatic control is achieved through a high lymphatic conductance in the pleural fluid and through a low interstitial compliance for the lung interstitium. Fluid volume in both compartments is so strictly controlled that it is difficult to detect initial deviations from the physiological state; thus, a great physiological advantage turns to be a disadvantage on a clinical basis as it prevents an early diagnosis of developing disease.

Age dependent white matter lesions and brain volume changes in healthy volunteers

DEFF Research Database (Denmark)

Christiansen, P; Larsson, H B; Thomsen, C

1994-01-01

The brain of 142 healthy volunteers aged 21 to 80 years were investigated using MR imaging. The number and size of the white matter hyperintensity lesions (WMHL) in the cerebral hemispheres were determined. Furthermore, the volume of the cerebral hemispheres and of the lateral ventricles was meas......The brain of 142 healthy volunteers aged 21 to 80 years were investigated using MR imaging. The number and size of the white matter hyperintensity lesions (WMHL) in the cerebral hemispheres were determined. Furthermore, the volume of the cerebral hemispheres and of the lateral ventricles...... was measured. An almost linear increase in the number of volunteers with WMHL was seen with aging for males and females. With aging a significant decrease in the volume of the cerebral hemispheres was found for males, and a significant increase in the volume of the lateral ventricles was seen for both males...... and females. Our results suggest that with aging central atrophy increases more (relatively) than cortical atrophy. No correlation was found between the decreasing volume of the cerebral hemispheres and the increasing number and size of WMHL, nor between the increasing volume of the lateral ventricles...

Higher vs. lower fluid volume for septic shock

DEFF Research Database (Denmark)

Smith, Søren H; Perner, Anders

2012-01-01

.4 (2.2-5.5) vs. 2.0 (1.6-3.0) mmol l-1, P vs. 54 (45-67), P = 0.73), sequential organ failure assessment (SOFA) score (11 (9-13) vs. 11 (9-13), P = 0.78) and 90-day mortality (48 vs...... volumes. Characteristics between these groups were compared using non-parametric and Chi-square statistics. RESULTS: The 164 included patients received median 4.0 l (IQR 2.3-6.3) of fluid during the first day of septic shock. Patients receiving higher volumes (> 4.0 l) on day 1 had higher p-lactate (3....... 53%, P = 0.27) did not differ between groups. The 95 patients who still had shock on day 3 had received 7.5 l (4.3 - 10.8) of fluid by the end of day 3. Patients receiving higher volumes (> 7.5 l) had higher p-lactate (2.6 (1.7-3.4) vs. 1.9 (1.6-2.4) mmol l-1, P

Second-order accurate volume-of-fluid algorithms for tracking material interfaces

International Nuclear Information System (INIS)

Pilliod, James Edward; Puckett, Elbridge Gerry

2004-01-01

We introduce two new volume-of-fluid interface reconstruction algorithms and compare the accuracy of these algorithms to four other widely used volume-of-fluid interface reconstruction algorithms. We find that when the interface is smooth (e.g., continuous with two continuous derivatives) the new methods are second-order accurate and the other algorithms are first-order accurate. We propose a design criteria for a volume-of-fluid interface reconstruction algorithm to be second-order accurate. Namely, that it reproduce lines in two space dimensions or planes in three space dimensions exactly. We also introduce a second-order, unsplit, volume-of-fluid advection algorithm that is based on a second-order, finite difference method for scalar conservation laws due to Bell, Dawson and Shubin. We test this advection algorithm by modeling several different interface shapes propagating in two simple incompressible flows and compare the results with the standard second-order, operator-split advection algorithm. Although both methods are second-order accurate when the interface is smooth, we find that the unsplit algorithm exhibits noticeably better resolution in regions where the interface has discontinuous derivatives, such as at corners

Osseous lesions of the pelvis and long tubular bones containing both fat and fluid-like signal intensity: an analysis of 28 patients

International Nuclear Information System (INIS)

Chung, Christine B.; Murphey, Mark; Cho, Gina; Schweitzer, Mark; Hodler, Jeurg; Haghihi, Parvis; Resnick, Donald

2005-01-01

Purpose: The purpose of this study was to explore the nature of lesions in the pelvis and the long tubular bones that, with MR imaging, were found to contain both fat and fluid-like signal intensity and to correlate these findings with those of radiography, histologic analysis, and clinical and radiographic follow-up. Materials and methods: A retrospective review of the radiologic, clinical and histologic parameters of 28 patients with lesions in the pelvis and long tubular bones comprised of elements that demonstrated both fat and fluid signal intensity characteristics by MR imaging was performed. Several parameters were analyzed. Histologic analysis was available in 12 patients. Clinical and, or imaging follow-up was available in 13 patients. Results: Imaging and histologic findings suggested the presence of fat and fluid and fluid components in all lesions with which could be divided into distinct MR imaging patterns. Histologic analysis suggested the possibility of a shared pathogenesis among several different lesions. Conclusion: All lesions of the long tubular bones in our series revealing both fat and fluid-like signal intensities with MR imaging were nonaggressive on the basis of other imaging findings, follow-up assessment, histologic analysis, or combinations of the three. Histologic findings suggest a relationship among lipomas, fat necrosis and cystic infarct of bone

Residual limb fluid volume change and volume accommodation: Relationships to activity and self-report outcomes in people with trans-tibial amputation.

Science.gov (United States)

Sanders, Joan E; Youngblood, Robert T; Hafner, Brian J; Ciol, Marcia A; Allyn, Katheryn J; Gardner, David; Cagle, John C; Redd, Christian B; Dietrich, Colin R

2018-02-01

Fluctuations in limb volume degrade prosthesis fit and require users to accommodate changes using management strategies, such as donning and doffing prosthetic socks. To examine how activities and self-report outcomes relate to daily changes in residual limb fluid volume and volume accommodation. Standardized, two-part laboratory protocol with an interim observational period. Participants were classified as "accommodators" or "non-accommodators," based on self-report prosthetic sock use. Participants' residual limb fluid volume change was measured using a custom bioimpedance analyzer and a standardized in-laboratory activity protocol. Self-report health outcomes were assessed with the Socket Comfort Score and Prosthesis Evaluation Questionnaire. Activity was monitored while participants left the laboratory for at least 3 h. They then returned to repeat the bioimpedance test protocol. Twenty-nine people were enrolled. Morning-to-afternoon percent limb fluid volume change per hour was not strongly correlated to percent time weight-bearing or to self-report outcomes. As a group, non-accommodators ( n = 15) spent more time with their prosthesis doffed and reported better outcomes than accommodators. Factors other than time weight-bearing may contribute to morning-to-afternoon limb fluid volume changes and reported satisfaction with the prosthesis among trans-tibial prosthesis users. Temporary doffing may be a more effective and satisfying accommodation method than sock addition. Clinical relevance Practitioners should be mindful that daily limb fluid volume change and prosthesis satisfaction are not dictated exclusively by activity. Temporarily doffing the prosthesis may slow daily limb fluid volume loss and should be investigated as an alternative strategy to sock addition.

Epicardial fat volume is correlated with coronary lesion and its severity.

Science.gov (United States)

Bo, Xiaohong; Ma, Likun; Fan, Jili; Jiang, Zhe; Zhou, Yuansong; Zhang, Lei; Li, Wanjun

2015-01-01

To evaluate the correlation of epicardial adipose tissue volume (EATV) with the coronary artery lesion and its severity. Inpatients with suspicious stable angina of coronary heart lesion were recruited. For patients with coronary artery lesions in CTA, further coronary angiography (CAG) was performed to evaluate the coronary artery lesion. Gensini scoring system was employed to assess the severity of coronary artery lesions. Patients were classified as coronary heart disease (CHD) group (n = 160). Results showed the mean EATV was 192.57 ± 30.32 cm(3) in CHD group, which was significantly larger than that in control group (138.56 ± 23.18 cm(3); P EATV among patients with different severities of coronary artery stenosis (P EATV (r = 0.285, P = 0.000). The EATV increased with the increase in the number of affected coronary arteries. Multivariate Logistic regression analysis showed EATV was an independent risk factor of CHD after adjusting other confounding factors (OR = 1.023, P = 0.013). EATV is closely related to the severity of coronary artery lesions: the larger the EATV, the more severe the coronary artery lesions. Moreover, EATV is an independent risk factor of CHD.

Determination of gas volume trapped in a closed fluid system

Science.gov (United States)

Hunter, W. F.; Jolley, J. E.

1971-01-01

Technique involves extracting known volume of fluid and measuring system before and after extraction, volume of entrapped gas is then computed. Formula derived from ideal gas laws is basis of this method. Technique is applicable to thermodynamic cycles and hydraulic systems.

Computer simulation of preflight blood volume reduction as a countermeasure to fluid shifts in space flight

Science.gov (United States)

Simanonok, K. E.; Srinivasan, R.; Charles, J. B.

1992-01-01

Fluid shifts in weightlessness may cause a central volume expansion, activating reflexes to reduce the blood volume. Computer simulation was used to test the hypothesis that preadaptation of the blood volume prior to exposure to weightlessness could counteract the central volume expansion due to fluid shifts and thereby attenuate the circulatory and renal responses resulting in large losses of fluid from body water compartments. The Guyton Model of Fluid, Electrolyte, and Circulatory Regulation was modified to simulate the six degree head down tilt that is frequently use as an experimental analog of weightlessness in bedrest studies. Simulation results show that preadaptation of the blood volume by a procedure resembling a blood donation immediately before head down bedrest is beneficial in damping the physiologic responses to fluid shifts and reducing body fluid losses. After ten hours of head down tilt, blood volume after preadaptation is higher than control for 20 to 30 days of bedrest. Preadaptation also produces potentially beneficial higher extracellular volume and total body water for 20 to 30 days of bedrest.

The effect of intraocular gas and fluid volumes on intraocular pressure.

Science.gov (United States)

Simone, J N; Whitacre, M M

1990-02-01

Large increases in the intraocular pressure (IOP) of postoperative gas-containing eyes may require the removal of gas or fluid to reduce the IOP to the normal range. Application of the ideal gas law to Friedenwald's equation provides a mathematical model of the relationship between IOP, intraocular gas and fluid volumes, and the coefficient of scleral rigidity. This mathematic model shows that removal of a given volume of gas or fluid produces an identical decrease in IOP and that the more gas an eye contains, the greater the volume reduction necessary to reduce the pressure. Application of the model shows that the effective coefficient of scleral rigidity is low (mean K, 0.0021) in eyes with elevated IOP that have undergone vitrectomy and retinal cryopexy and very low (mean K, 0.0013) in eyes with elevated IOP that have undergone placement of a scleral buckle and band. By using the appropriate mean coefficient of rigidity, the volume of material to be aspirated to produce a given decrease in IOP can be predicted with clinically useful accuracy.

Initial 12-h operative fluid volume is an independent risk factor for pleural effusion after hepatectomy.

Science.gov (United States)

Cheng, Xiang; Wu, Jia-Wei; Sun, Ping; Song, Zi-Fang; Zheng, Qi-Chang

2016-12-01

Pleural effusion after hepatectomy is associated with significant morbidity and prolonged hospital stays. Several studies have addressed the risk factors for postoperative pleural effusion. However, there are no researches concerning the role of the initial 12-h operative fluid volume. The aim of this study was to evaluate whether the initial 12-h operative fluid volume during liver resection is an independent risk factor for pleural effusion after hepatectomy. In this study, we retrospectively analyzed clinical data of 470 patients consecutively undergoing elective hepatectomy between January 2011 and December 2012. We prospectively collected and retrospectively analyzed baseline and clinical data, including preoperative, intraoperative, and postoperative variables. Univariate and multivariate analyses were carried out to identify whether the initial 12-h operative fluid volume was an independent risk factor for pleural effusion after hepatectomy. The multivariate analysis identified 2 independent risk factors for pleural effusion: operative time [odds ratio (OR)=10.2] and initial 12-h operative fluid volume (OR=1.0003). Threshold effect analyses revealed that the initial 12 h operative fluid volume was positively correlated with the incidence of pleural effusion when the initial 12-h operative fluid volume exceeded 4636 mL. We conclude that the initial 12-h operative fluid volume during liver resection and operative time are independent risk factors for pleural effusion after hepatectomy. Perioperative intravenous fluids should be restricted properly.

SOLA-VOF, 2-D Transient Hydrodynamic Using Fractional Volume of Fluid Method

International Nuclear Information System (INIS)

Nichols, B.D.; Hirt, C.W.; Hotchkiss, R.S.

1991-01-01

1 - Description of problem or function: SOLA-VOF is a program for the solution of two-dimensional transient fluid flow with free boundaries, based on the concept of a fractional volume of fluid (VOF). Its basic mode of operation is for single fluid calculations having multiple free surfaces. However, SOLA-VOF can also be used for calculations involving two fluids separated by a sharp interface. In either case, the fluids may be treated as incompressible or as having limited compressibility. Surface tension forces with wall adhesion are permitted in both cases. Internal obstacles may be defined by blocking out any desired combination of cells in the mesh, which is composed of rectangular cells of variable size. 2 - Method of solution: The basis of the SOLA-VOF method is the fractional volume of fluid scheme for tracking free boundaries. In this technique, a function F(x,y,t) is defined whose value is unity at any point occupied by fluid and zero elsewhere. When averaged over the cells of a computational mesh, the average value of F in a cell is equal to the fractional volume of the cell occupied by fluid. In particular, a unit value of F corresponds to a cell full of fluid, whereas a zero value indicates that the cell contains no fluid. Cells with F values between zero and one contain a free surface. SOLA-VOF uses an Eulerian mesh of rectangular cells having variable sizes. The fluid equations solved are the finite difference approximations of the Navier-Stokes equations. 3 - Restrictions on the complexity of the problem: The setting of array dimensions is controlled through PARAMETER statements

Cardiovascular and fluid volume control in humans in space

DEFF Research Database (Denmark)

Norsk, Peter

2005-01-01

on this complex interaction, because it is the only way to completely abolish the effects of gravity over longer periods. Results from space have been unexpected, because astronauts exhibit a fluid and sodium retaining state with activation of the sympathetic nervous system, which subjects during simulations...... by head-down bed rest do not. Therefore, the concept as to how weightlessness affects the cardiovascular system and modulates regulation of body fluids should be revised and new simulation models developed. Knowledge as to how gravity and weightlessness modulate integrated fluid volume control...

Associations of Hospital and Patient Characteristics with Fluid Resuscitation Volumes in Patients with Severe Sepsis

DEFF Research Database (Denmark)

Hjortrup, Peter Buhl; Haase, Nicolai; Wetterslev, Jørn

2016-01-01

PURPOSE: Fluid resuscitation is a key intervention in patients with sepsis and circulatory impairment. The recommendations for continued fluid therapy in sepsis are vague, which may result in differences in clinical practice. We aimed to evaluate associations between hospital and patient characte....... The data indicate variations in clinical practice not explained by patient characteristics emphasizing the need for RCTs assessing fluid resuscitation volumes fluid in patients with sepsis.......PURPOSE: Fluid resuscitation is a key intervention in patients with sepsis and circulatory impairment. The recommendations for continued fluid therapy in sepsis are vague, which may result in differences in clinical practice. We aimed to evaluate associations between hospital and patient...... characteristics and fluid resuscitation volumes in ICU patients with severe sepsis. METHODS: We explored the 6S trial database of ICU patients with severe sepsis needing fluid resuscitation randomised to hydroxyethyl starch 130/0.42 vs. Ringer's acetate. Our primary outcome measure was fluid resuscitation volume...

Effects of fluid communications between fluid volumes on the seismic behaviour of nuclear breeder reactor internals

International Nuclear Information System (INIS)

Durandet, E.; Gibert, R.J.

1987-01-01

The internal structures of a breeder reactor as SUPERPHENIX are mainly axisymmetrial shells separated by fluid volumes which are connected by small communications holes. These communications can destroy the axisymmetry of the problem and their effects on the inertial terms due to the fluid are important. An equivalent axisymmetrical element based on a local tridimensional solution in the vicinity of the fluid communication is defined. An axisymmetrical modelization using this type of element is built in order to calculate the horizontal seismic behaviour of the reactor internals. The effect due to three typical fluid communications are studied and compared. (orig.)

The yield of different pleural fluid volumes for Mycobacterium tuberculosis culture.

Science.gov (United States)

von Groote-Bidlingmaier, Florian; Koegelenberg, Coenraad Frederik; Bolliger, Chris T; Chung, Pui Khi; Rautenbach, Cornelia; Wasserman, Elizabeth; Bernasconi, Maurizio; Friedrich, Sven Olaf; Diacon, Andreas Henri

2013-03-01

We prospectively compared the culture yields of two pleural fluid volumes (5 and 100 ml) inoculated in liquid culture medium in 77 patients of whom 58 (75.3%) were diagnosed with pleural tuberculosis. The overall fluid culture yield was high (60.3% of cases with pleural tuberculosis). The larger volume had a faster time to positivity (329 vs 376 h, p=0.055) but its yield was not significantly higher (53.5% vs 50%; p=0.75). HIV-positive patients were more likely to have positive cultures (78.9% vs 51.5%; p=0.002).

Sonographic Findings of Morel-Lavalle'e Lesions

International Nuclear Information System (INIS)

Oh, Yu Jin; Yang, Ik; Lee, Yul; Woo, Ji Young; Hong, Hye Suk; Jung, Ah Young; Jeh, Su Kyung

2011-01-01

We reviewed the sonographic features of Morel-Lavalle'e lesions by correlating the US image findings with a lesion's age. We obtained the sonography reports of 20 Morel-Lavalle'e lesions of the hip and extremities from 18 patients with a history of trauma. The US images were reviewed to characterize the echogenicity, shape, homogeneity, margins, location and size of the lesions. The results were correlated with the age of the lesions and the clinical histories. All the Morel-Lavalle'e lesions were hypoechoic or anechoic fluid collections located between the subcutaneous fat and the underlying fascia. Regarding the shape of the fluid collections, the lobular shaped lesions were all less than 21 days for the lesion's age, and the flat fluid collections were all greater than 1 month of age. Regarding the homogeneity, the heterogeneous fluid collections were all less than 25 days of age, and the homogeneous fluid collections were all greater than 1 month of age. A Morel-Lavalle'e lesion is seen as a posttraumatic fluid collection in the potential space between the subcutaneous fat and the underlying fascia on an ultrasound examination. Acute Morel-Lavalle'e lesions tended to be heterogeneous and lobular, and they became more homogeneous and flat in shape as the lesions evolved. Awareness of these imaging findings will help us to properly diagnose Morel- Lavalle'e lesions

The volume of fluid method in spherical coordinates

NARCIS (Netherlands)

Janse, A.M.C.; Janse, A.M.C.; Dijk, P.E.; Kuipers, J.A.M.

2000-01-01

The volume of fluid (VOF) method is a numerical technique to track the developing free surfaces of liquids in motion. This method can, for example, be applied to compute the liquid flow patterns in a rotating cone reactor. For this application a spherical coordinate system is most suited. The novel

The effect of ethanol infusion on the size of the ablated lesion in radiofrequency thermal ablation: A pilot study

International Nuclear Information System (INIS)

Kim, Young Sun; Rhim, Hyun Chul; Koh, Byung Hee; Cho, On Koo; Seo, Heung Suk; Kim, Yong Soo; Joo, Kyoung Bin

2001-01-01

To assess the effect of ethanol infusion on the size of ablated lesion during radiofrequency (RF) thermal ablation. We performed an ex vivo experimental study using a total of 15 pig livers. Three groups were designed: 1)normal control (n=10), 2) saline infusion (n=10) 3) ethanol infusion (n=10). Two radiofrequency ablations were done using a 50 watt RF generator and a 15 guage expandable elections with four prongs in each liver. During ablation for 8 minutes, continuous infusion of fluid at a rate of 0.5 ml/min through the side arm of electrode was performed. We checked the frequency of the 'impeded-out' phenomenon due to abrupt increase of impedance during ablation. Size of ablated lesion was measured according to length, width, height, and subsequently volume after the ablations. The sizes of the ablated lesions were compared between the three groups. 'Impeded-out' phenomenon during ablation was noted 4 times in control group, although that never happened in saline or ethanol infusion groups. There were significant differences in the volumes of ablated lesions between control group (10.62 ± 1.45 cm 3 ) and saline infusion group (15.33 ± 2.47 cm 3 ), and saline infusion group and ethanol infusion group (18.78 ± 3.58 cm 3 ) (p<0.05). Fluid infusion during radiofrequency thermal ablation decrease a chance of charming and increase the volume of the ablated lesion. Ethanol infusion during ablation may induce larger volume of ablated lesion than saline infusion.

Percutaneous Image-Guided Cryoablation of Challenging Mediastinal Lesions Using Large-Volume Hydrodissection: Technical Considerations and Outcomes

Energy Technology Data Exchange (ETDEWEB)

Garnon, Julien, E-mail: juliengarnon@gmail.com; Koch, Guillaume, E-mail: Guillaume.koch@gmail.com; Caudrelier, Jean, E-mail: caudjean@yahoo.fr [University Hospital of Strasbourg, Department of Interventional Radiology (France); Ramamurthy, Nitin, E-mail: Nitin-ramamurthy@hotmail.com [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Rao, Pramod, E-mail: pramodrao@me.com [University of Strasbourg, ICube (France); Tsoumakidou, Georgia, E-mail: Georgia.tsoumakidou@chru-strasbourg.fr; Cazzato, Roberto Luigi, E-mail: cazzatorobertoluigi@gmail.com; Gangi, Afshin, E-mail: Afshin.gangi@chru-strasbourg.fr [University Hospital of Strasbourg, Department of Interventional Radiology (France)

2016-11-15

ObjectiveThis study was designed to describe the technique of percutaneous image-guided cryoablation with large-volume hydrodissection for the treatment of challenging mediastinal lesions.MethodsBetween March 2014 and June 2015, three patients (mean age 62.7 years) with four neoplastic anterior mediastinal lesions underwent five cryoablation procedures using large-volume hydrodissection. Procedures were performed under general anaesthesia using CT guidance. Lesion characteristics, hydrodissection and cryoablation data, technical success, complications, and clinical outcomes were assessed using retrospective chart review.ResultsLesions (mean size 2.7 cm; range 2–4.3 cm) were in contact with great vessels (n = 13), trachea (n = 3), and mediastinal nerves (n = 6). Hydrodissection was performed intercostally (n = 4), suprasternally (n = 2), transsternally (n = 1), or via the sternoclavicular joint (n = 1) using 1–3 spinal needles over 13.4 (range 7–26) minutes; 450 ml of dilute contrast was injected (range 300–600 ml) and increased mean lesion-collateral structure distance from 1.9 to 7.7 mm. Vulnerable mediastinal nerves were identified in four of five procedures. Technical success was 100 %, with one immediate complication (recurrent laryngeal nerve injury). Mean follow-up period was 15 months. One lesion demonstrated residual disease on restaging PET-CT and was retreated to achieve complete ablation. At last follow-up, two patients remained disease-free, and one patient developed distant disease after 1 year without local recurrence.ConclusionsCryoablation using large-volume hydrodissection is a feasible technique, enabling safe and effective treatment of challenging mediastinal lesions.

Serial assessment of pulmonary lesion volume by computed tomography allows survival prediction in invasive pulmonary aspergillosis

Energy Technology Data Exchange (ETDEWEB)

Vehreschild, J.J.; Vehreschild, M.J.G.T. [University Hospital of Cologne, Department I of Internal Medicine, Cologne (Germany); German Centre for Infection Research, Partner Site Bonn-Cologne, Cologne (Germany); Heussel, C.P. [Chest Clinic at University Hospital Heidelberg, Diagnostic and Interventional Radiology with Nuclear Medicine, Heidelberg (Germany); University Hospital of Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (DZL), Heidelberg (Germany); Groll, A.H. [University Children' s Hospital, Infectious Disease Research Program, Department of Paediatric Haematology/Oncology, Muenster (Germany); Silling, G. [University of Muenster, Department of Medicine A, Haematology/Oncology, Muenster (Germany); Wuerthwein, G. [University Hospital Muenster, Centre for Clinical Trials, ZKS Muenster (Germany); Brecht, M. [Chest Clinic at University Hospital Heidelberg, Diagnostic and Interventional Radiology with Nuclear Medicine, Heidelberg (Germany); Cornely, O.A. [University Hospital of Cologne, Department I of Internal Medicine, Cologne (Germany); University of Cologne, Clinical Trials Center Cologne, ZKS Koeln (BMBF 01KN1106), Cologne (Germany); Center for Integrated Oncology CIO Koeln Bonn, Cologne (Germany); University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne (Germany)

2017-08-15

Serial chest CT is the standard of care to establish treatment success in invasive pulmonary aspergillosis (IPA). Data are lacking how response should be defined. Digital CT images from a clinical trial on treatment of IPA were re-evaluated and compared with available biomarkers. Total volume of pneumonia was added up after manual measurement of each lesion, followed by statistical analysis. One-hundred and ninety CT scans and 309 follow-up datasets from 40 patients were available for analysis. Thirty-one were neutropenic. Baseline galactomannan (OR 4.06, 95%CI: 1.08-15.31) and lesion volume (OR 3.14, 95%CI: 0.73-13.52) were predictive of death. Lesion volume at d7 and trend between d7 and d14 were strong predictors of death (OR 20.01, 95%CI: 1.42-282.00 and OR 15.97, 95%CI: 1.62-157.32) and treatment being rated as unsuccessful (OR 4.75, 95%CI: 0.94-24.05 and OR 40.69, 95%CI: 2.55-649.03), which was confirmed by a Cox proportional hazards model using time-dependent covariates. Any increase in CT lesion volume between day 7 and day 14 was a sensitive marker of a lethal outcome (>50%), supporting a CT rescan each one and 2 weeks after initial detection of IPA. The predictive value exceeded all other biomarkers. Further CT follow-up after response at day 14 was of low additional value. (orig.)

A volume of fluid method based on multidimensional advection and spline interface reconstruction

International Nuclear Information System (INIS)

Lopez, J.; Hernandez, J.; Gomez, P.; Faura, F.

2004-01-01

A new volume of fluid method for tracking two-dimensional interfaces is presented. The method involves a multidimensional advection algorithm based on the use of edge-matched flux polygons to integrate the volume fraction evolution equation, and a spline-based reconstruction algorithm. The accuracy and efficiency of the proposed method are analyzed using different tests, and the results are compared with those obtained recently by other authors. Despite its simplicity, the proposed method represents a significant improvement, and compares favorably with other volume of fluid methods as regards the accuracy and efficiency of both the advection and reconstruction steps

Automatic segmentation and volumetry of multiple sclerosis brain lesions from MR images

Directory of Open Access Journals (Sweden)

Saurabh Jain

2015-01-01

Full Text Available The location and extent of white matter lesions on magnetic resonance imaging (MRI are important criteria for diagnosis, follow-up and prognosis of multiple sclerosis (MS. Clinical trials have shown that quantitative values, such as lesion volumes, are meaningful in MS prognosis. Manual lesion delineation for the segmentation of lesions is, however, time-consuming and suffers from observer variability. In this paper, we propose MSmetrix, an accurate and reliable automatic method for lesion segmentation based on MRI, independent of scanner or acquisition protocol and without requiring any training data. In MSmetrix, 3D T1-weighted and FLAIR MR images are used in a probabilistic model to detect white matter (WM lesions as an outlier to normal brain while segmenting the brain tissue into grey matter, WM and cerebrospinal fluid. The actual lesion segmentation is performed based on prior knowledge about the location (within WM and the appearance (hyperintense on FLAIR of lesions. The accuracy of MSmetrix is evaluated by comparing its output with expert reference segmentations of 20 MRI datasets of MS patients. Spatial overlap (Dice between the MSmetrix and the expert lesion segmentation is 0.67 ± 0.11. The intraclass correlation coefficient (ICC equals 0.8 indicating a good volumetric agreement between the MSmetrix and expert labelling. The reproducibility of MSmetrix' lesion volumes is evaluated based on 10 MS patients, scanned twice with a short interval on three different scanners. The agreement between the first and the second scan on each scanner is evaluated through the spatial overlap and absolute lesion volume difference between them. The spatial overlap was 0.69 ± 0.14 and absolute total lesion volume difference between the two scans was 0.54 ± 0.58 ml. Finally, the accuracy and reproducibility of MSmetrix compare favourably with other publicly available MS lesion segmentation algorithms, applied on the same data using default

A SUB-GRID VOLUME-OF-FLUIDS (VOF) MODEL FOR MIXING IN RESOLVED SCALE AND IN UNRESOLVED SCALE COMPUTATIONS

International Nuclear Information System (INIS)

Vold, Erik L.; Scannapieco, Tony J.

2007-01-01

A sub-grid mix model based on a volume-of-fluids (VOF) representation is described for computational simulations of the transient mixing between reactive fluids, in which the atomically mixed components enter into the reactivity. The multi-fluid model allows each fluid species to have independent values for density, energy, pressure and temperature, as well as independent velocities and volume fractions. Fluid volume fractions are further divided into mix components to represent their 'mixedness' for more accurate prediction of reactivity. Time dependent conversion from unmixed volume fractions (denoted cf) to atomically mixed (af) fluids by diffusive processes is represented in resolved scale simulations with the volume fractions (cf, af mix). In unresolved scale simulations, the transition to atomically mixed materials begins with a conversion from unmixed material to a sub-grid volume fraction (pf). This fraction represents the unresolved small scales in the fluids, heterogeneously mixed by turbulent or multi-phase mixing processes, and this fraction then proceeds in a second step to the atomically mixed fraction by diffusion (cf, pf, af mix). Species velocities are evaluated with a species drift flux, ρ i u di = ρ i (u i -u), used to describe the fluid mixing sources in several closure options. A simple example of mixing fluids during 'interfacial deceleration mixing with a small amount of diffusion illustrates the generation of atomically mixed fluids in two cases, for resolved scale simulations and for unresolved scale simulations. Application to reactive mixing, including Inertial Confinement Fusion (ICF), is planned for future work.

Dysglycemia, brain volume and vascular lesions on MRI in a memory clinic population

NARCIS (Netherlands)

Exalto, L.G.; van der Flier, W.M.; Scheltens, P.; Vrenken, H.; Biessels, G.J.

2014-01-01

Objective It is unclear, if the association between abnormalities in glucose metabolism (dysglycemia) and impaired cognitive functioning is primarily driven by degenerative or vascular brain damage. We therefore examined the relation between dysglycemia and brain volume and vascular lesions on MRI

Sonographic Findings of Morel-Lavalle'e Lesions

Energy Technology Data Exchange (ETDEWEB)

Oh, Yu Jin; Yang, Ik; Lee, Yul; Woo, Ji Young; Hong, Hye Suk; Jung, Ah Young; Jeh, Su Kyung [Kangnam Sacred Heart Hospital, College of Medicine, Hallym University, Seoul (Korea, Republic of)

2011-09-15

We reviewed the sonographic features of Morel-Lavalle'e lesions by correlating the US image findings with a lesion's age. We obtained the sonography reports of 20 Morel-Lavalle'e lesions of the hip and extremities from 18 patients with a history of trauma. The US images were reviewed to characterize the echogenicity, shape, homogeneity, margins, location and size of the lesions. The results were correlated with the age of the lesions and the clinical histories. All the Morel-Lavalle'e lesions were hypoechoic or anechoic fluid collections located between the subcutaneous fat and the underlying fascia. Regarding the shape of the fluid collections, the lobular shaped lesions were all less than 21 days for the lesion's age, and the flat fluid collections were all greater than 1 month of age. Regarding the homogeneity, the heterogeneous fluid collections were all less than 25 days of age, and the homogeneous fluid collections were all greater than 1 month of age. A Morel-Lavalle'e lesion is seen as a posttraumatic fluid collection in the potential space between the subcutaneous fat and the underlying fascia on an ultrasound examination. Acute Morel-Lavalle'e lesions tended to be heterogeneous and lobular, and they became more homogeneous and flat in shape as the lesions evolved. Awareness of these imaging findings will help us to properly diagnose Morel- Lavalle'e lesions

Spinal level of myelomeningocele lesion as a contributing factor in posterior fossa volume, intracranial cerebellar volume, and cerebellar ectopia.

LENUS (Irish Health Repository)

Sweeney, Kieron J

2013-02-01

McLone and Knepper\\'s unified theory of Chiari malformation Type II (CM-II) describes how the loss of CSF via the open posterior neuropore fails to create adequate distending pressure for the developing rhomboencephalic vesicle. The authors of the present article describe the relationship between the posterior fossa volume and intracranial cerebellar volume as being related to the distance from the obex of the fourth ventricle to the myelomeningocele lesion using a common mathematical model, the Hagen-Poiseuille law.

Is There Volume Transmission Along Extracellular Fluid Pathways Corresponding to the Acupuncture Meridians?

Directory of Open Access Journals (Sweden)

Weibo Zhang

2017-02-01

Full Text Available Volume transmission is a new major communication signaling via extracellular fluid (interstitial fluid pathways. It was proposed by the current authors that such pathways can explain the meridian phenomena and acupuncture effects. To investigate whether meridian-like structures exist in fish body and operate via volume transmission in extracellular fluid pathways, we injected alcian blue (AB under anesthesia into Gephyrocharax melanocheir, which has a translucent body. The migration of AB could be seen directly and was recorded by a digital camera. The fish was then embedded and cut transversely to observe the position of tracks in three dimensions. Eight longitudinal threadlike blue tracks were recognized on the fish. The positions of these threadlike tracks were similar to meridians on the human body. Transverse sections showed that these tracks distributed to different layers of distinct subcutaneous loose connective tissues and intermuscular septa. Lymphatic vessels were sometimes associated with the extracellular blue tracks where the migration of AB occurred. Extracellular fluid pathways were found on fish through their transport of AB. These pathways operating via volume transmission appeared to be similar in positions and functions to the acupuncture meridians in Chinese medicine.

Amylase, lipase, and volume of drainage fluid in gastrectomy for the early detection of complications caused by pancreatic leakage.

Science.gov (United States)

Seo, Kyung Won; Yoon, Ki Young; Lee, Sang Ho; Shin, Yeon Myung; Choi, Kyung Hyun; Hwang, Hyun Yong

2011-12-01

Pancreatic leakage is a serious complication of gastrectomy due to stomach cancer. Therefore, we analyzed amylase and lipase concentrations in blood and drainage fluid, and evaluated the volume of drainage fluid to discern their usefulness as markers for the early detection of serious pancreatic leakage requiring reoperation after gastrectomy. From January 2001 to December 2007, we retrospectively analyzed data from 24,072 patient samples. We divided patients into two groups; 1) complications with pancreatic leakage (CG), and 2) no complications associated with pancreatic leakage (NCG). Values of amylase and lipase in the blood and drainage fluid, volume of the drainage fluid, and relationships among the volumes, amylase values, and lipase values in the drainage fluid were evaluated, respectively in the two groups. The mean amylase values of CG were significantly higher than those of NCG in blood and drainage fluid (P < 0.05). For lipase, statistically significant differences were observed in drainage fluid (P < 0.05). The mean volume (standard deviation) of the drained fluid through the tube between CG (n = 22) and NCG (n = 236) on postoperative day 1 were 368.41 (266.25) and 299.26 (300.28), respectively. There were no statistically significant differences between the groups (P = 0.298). There was a correlation between the amylase and lipase values in the drainage fluid (r = 0.812, P = 0.000). Among postoperative amylase and lipase values in blood and drainage fluid, and the volume of drainage fluid, the amylase in drainage fluid was better differentiated between CG and NCG than other markers. The volume of the drainage fluid did not differ significantly between groups.

Balance point characterization of interstitial fluid volume regulation.

Science.gov (United States)

Dongaonkar, R M; Laine, G A; Stewart, R H; Quick, C M

2009-07-01

The individual processes involved in interstitial fluid volume and protein regulation (microvascular filtration, lymphatic return, and interstitial storage) are relatively simple, yet their interaction is exceedingly complex. There is a notable lack of a first-order, algebraic formula that relates interstitial fluid pressure and protein to critical parameters commonly used to characterize the movement of interstitial fluid and protein. Therefore, the purpose of the present study is to develop a simple, transparent, and general algebraic approach that predicts interstitial fluid pressure (P(i)) and protein concentrations (C(i)) that takes into consideration all three processes. Eight standard equations characterizing fluid and protein flux were solved simultaneously to yield algebraic equations for P(i) and C(i) as functions of parameters characterizing microvascular, interstitial, and lymphatic function. Equilibrium values of P(i) and C(i) arise as balance points from the graphical intersection of transmicrovascular and lymph flows (analogous to Guyton's classical cardiac output-venous return curves). This approach goes beyond describing interstitial fluid balance in terms of conservation of mass by introducing the concept of inflow and outflow resistances. Algebraic solutions demonstrate that P(i) and C(i) result from a ratio of the microvascular filtration coefficient (1/inflow resistance) and effective lymphatic resistance (outflow resistance), and P(i) is unaffected by interstitial compliance. These simple algebraic solutions predict P(i) and C(i) that are consistent with reported measurements. The present work therefore presents a simple, transparent, and general balance point characterization of interstitial fluid balance resulting from the interaction of microvascular, interstitial, and lymphatic function.

Lesion segmentation from multimodal MRI using random forest following ischemic stroke.

Science.gov (United States)

Mitra, Jhimli; Bourgeat, Pierrick; Fripp, Jurgen; Ghose, Soumya; Rose, Stephen; Salvado, Olivier; Connelly, Alan; Campbell, Bruce; Palmer, Susan; Sharma, Gagan; Christensen, Soren; Carey, Leeanne

2014-09-01

Understanding structure-function relationships in the brain after stroke is reliant not only on the accurate anatomical delineation of the focal ischemic lesion, but also on previous infarcts, remote changes and the presence of white matter hyperintensities. The robust definition of primary stroke boundaries and secondary brain lesions will have significant impact on investigation of brain-behavior relationships and lesion volume correlations with clinical measures after stroke. Here we present an automated approach to identify chronic ischemic infarcts in addition to other white matter pathologies, that may be used to aid the development of post-stroke management strategies. Our approach uses Bayesian-Markov Random Field (MRF) classification to segment probable lesion volumes present on fluid attenuated inversion recovery (FLAIR) MRI. Thereafter, a random forest classification of the information from multimodal (T1-weighted, T2-weighted, FLAIR, and apparent diffusion coefficient (ADC)) MRI images and other context-aware features (within the probable lesion areas) was used to extract areas with high likelihood of being classified as lesions. The final segmentation of the lesion was obtained by thresholding the random forest probabilistic maps. The accuracy of the automated lesion delineation method was assessed in a total of 36 patients (24 male, 12 female, mean age: 64.57±14.23yrs) at 3months after stroke onset and compared with manually segmented lesion volumes by an expert. Accuracy assessment of the automated lesion identification method was performed using the commonly used evaluation metrics. The mean sensitivity of segmentation was measured to be 0.53±0.13 with a mean positive predictive value of 0.75±0.18. The mean lesion volume difference was observed to be 32.32%±21.643% with a high Pearson's correlation of r=0.76 (p<0.0001). The lesion overlap accuracy was measured in terms of Dice similarity coefficient with a mean of 0.60±0.12, while the contour

ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

International Nuclear Information System (INIS)

Nagai, Katsuaki; Ushijima, Satoru

2010-01-01

A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

Science.gov (United States)

Nagai, Katsuaki; Ushijima, Satoru

2010-06-01

A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

Measurement of synovial fluid volume using urea.

Science.gov (United States)

Kraus, V B; Stabler, T V; Kong, S Y; Varju, G; McDaniel, G

2007-10-01

To examine the utility of using urea concentrations for determining Synovial Fluid (SF) joint volume in effused and non-effused joints. Knee joint SF was aspirated from 159 human study participants with symptomatic osteoarthritis of at least one knee either directly (165 knees) or by lavage (110 knees). Serum was obtained immediately prior to SF aspiration. Participants were asked to rate individual knee pain, aching or stiffness. SF and serum urea levels were determined using a specific enzymatic method run on an automated CMA600 analyzer. Cell counts were performed on direct SF aspirates when volume permitted. The formula for calculating SF joint volume was as follows: V(j)=C(D)(V(I))/(C-C(D)) with V(j)=volume of SF in entire joint, C(D)=concentration of urea in diluted (lavage) SF, V(I)=volume of saline injected into joint, and C=concentration of urea in undiluted (neat) SF derived below where C=0.897(C(S)) and C(s)=concentration of urea in serum. There was an excellent correlation (r(2)=0.8588) between SF and serum urea in the direct aspirates with a ratio of 0.897 (SF/serum). Neither urea levels nor the SF/serum ratio showed any correlation with Kellgren Lawrence (KL) grade, or cell count. While urea levels increased with age there was no change in the ratio. Intraarticular SF volumes calculated for the lavaged knees ranged from 0.555 to 71.71ml with a median volume of 3.048ml. There was no correlation of SF volume to KL grade but there was a positive correlation (P=0.001) between SF volume and self-reported individual knee pain. Our urea results for direct aspirates indicate an equilibrium state between serum and SF with regard to the water fraction. This equilibrium exists regardless of disease status (KL grade), inflammation (cell count), or age, making it possible to calculate intraarticular volume of lavaged joints based upon this urea method. Most of the joint volumes we calculated fell within the previously reported range for normal knees of 0.5-4.0ml

Volume Modulated Arc Therapy (VMAT for pulmonary Stereotactic Body Radiotherapy (SBRT in patients with lesions in close approximation to the chest wall

Directory of Open Access Journals (Sweden)

Thomas J. FitzGerald

2013-02-01

Full Text Available Chest wall pain and discomfort has been recognized as a significant late effect of radiation therapy in historical and modern treatment models. Stereotactic Body Radiotherapy (SBRT is becoming an important treatment tool in oncology care for patients with intrathoracic lesions. For lesions in close approximation to the chest wall including lesions requiring motion management, SBRT techniques can deliver high dose to the chest wall. As an unintended target of consequence, there is possibility of generating significant chest wall pain and discomfort as a late effect of therapy. The purpose of this paper is to evaluate the potential role of Volume Modulated Arc Therapy (VMAT technologies in decreasing chest wall dose in SBRT treatment of pulmonary lesions in close approximation to the chest wall.Ten patients with pulmonary lesions of various sizes and topography in close approximation to the chest wall were selected for retrospective review. All volumes including target, chest wall, ribs, and lung were contoured with maximal intensity projection maps and four-dimensional computer tomography planning. Radiation therapy planning consisted of static techniques including Intensity Modulated Radiation Therapy compared to VMAT therapy to a dose of 60Gy in 12Gy fractions. Dose volume histogram to rib, chest wall, and lung were compared between plans with statistical analysis.In all patients dose and volume were improved to ribs and chest wall using VMAT technologies compared to static field techniques. On average, volume receiving 30Gy to the chest wall was improved by 72%;the ribs by 60%. In only one patient did the VMAT treatment technique increase pulmonary volume receiving 20Gy (V20.VMAT technology has potential of limiting radiation dose to sensitive chest wall regions in patients with lesions in close approximation to this structure. This would also have potential value to lesions treated with SBRT in other body regions where targets abut critical

[State of the art in fluid and volume therapy : A user-friendly staged concept].

Science.gov (United States)

Rehm, M; Hulde, N; Kammerer, T; Meidert, A S; Hofmann-Kiefer, K

2017-03-01

Adequate fluid therapy is highly important for the perioperative outcome of our patients. Both, hypovolemia and hypervolemia can lead to an increase in perioperative complications and can impair the outcome. Therefore, perioperative infusion therapy should be target-oriented. The main target is to maintain the patient's preoperative normovolemia by using a sophisticated, rational infusion strategy.Perioperative fluid losses should be discriminated from volume losses (surgical blood loss or interstitial volume losses containing protein). Fluid losses as urine or perspiratio insensibilis (0.5-1.0 ml/kg/h) should be replaced by balanced crystalloids in a ratio of 1:1. Volume therapy step 1: Blood loss up to a maximum value of 20% of the patient's blood volume should be replaced by balanced crystalloids in a ratio of 4(-5):1. Volume therapy step 2: Higher blood losses should be treated by using iso-oncotic, preferential balanced colloids in a ratio of 1:1. For this purpose hydroxyethyl starch can also be used perioperatively if there is no respective contraindication, such as sepsis, burn injuries, critically ill patients, renal impairment or renal replacement therapy, and severe coagulopathy. Volume therapy step 3: If there is an indication for red cell concentrates or coagulation factors, a differentiated application of blood and blood products should be performed.

Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Correlation with Clinical Severity and Old Brain Lesions

OpenAIRE

Seo, Kwon-Duk; Suh, Sang Hyun; Kim, Yong Bae; Kim, Ji Hwa; Ahn, Sung Jun; Kim, Dong-Seok; Lee, Kyung-Yul

2015-01-01

Purpose Leptomeningeal collateral, in moyamoya disease (MMD), appears as an ivy sign on fluid-attenuated inversion-recovery (FLAIR) images. There has been little investigation into the relationship between presentation of ivy signs and old brain lesions. We aimed to evaluate clinical significance of ivy signs and whether they correlate with old brain lesions and the severity of clinical symptoms in patients with MMD. Materials and Methods FLAIR images of 83 patients were reviewed. Each cerebr...

Topology as fluid geometry two-dimensional spaces, volume 2

CERN Document Server

Cannon, James W

2017-01-01

This is the second of a three volume collection devoted to the geometry, topology, and curvature of 2-dimensional spaces. The collection provides a guided tour through a wide range of topics by one of the twentieth century's masters of geometric topology. The books are accessible to college and graduate students and provide perspective and insight to mathematicians at all levels who are interested in geometry and topology. The second volume deals with the topology of 2-dimensional spaces. The attempts encountered in Volume 1 to understand length and area in the plane lead to examples most easily described by the methods of topology (fluid geometry): finite curves of infinite length, 1-dimensional curves of positive area, space-filling curves (Peano curves), 0-dimensional subsets of the plane through which no straight path can pass (Cantor sets), etc. Volume 2 describes such sets. All of the standard topological results about 2-dimensional spaces are then proved, such as the Fundamental Theorem of Algebra (two...

Morel-Lavallee lesion.

Science.gov (United States)

Li, Hui; Zhang, Fangjie; Lei, Guanghua

2014-01-01

To review current knowledge of the Morel-Lavallee lesion (MLL) to help clinicians become familiar with this entity. Familiarization may decrease missed diagnoses and misdiagnoses. It could also help steer the clinician to the proper treatment choice. A search was performed via PubMed and EMBASE from 1966 to July 2013 using the following keywords: Morel-Lavallee lesion, closed degloving injury, concealed degloving injury, Morel-Lavallee effusion, Morel-Lavallee hematoma, posttraumatic pseudocyst, posttraumatic soft tissue cyst. Chinese and English language literatures relevant to the subject were collected. Their references were also reviewed. Morel-Lavallee lesion is a relatively rare condition involving a closed degloving injury. It is characterized by a filled cystic cavity created by separation of the subcutaneous tissue from the underlying fascia. Apart from the classic location over the region of the greater trochanter, MLLs have been described in other parts of the body. The natural history of MLL has not yet been established. The lesion may decrease in volume, remain stable, enlarge progressively or show a recurrent pattern. Diagnosis of MLL was often missed or delayed. Ultrasonography, computed tomography, and magnetic resonance imaging have great value in the diagnosis of MLL. Treatment of MLL has included compression, local aspiration, open debridement, and sclerodesis. No standard treatment has been established. A diagnosis of MLL should be suspected when a soft, fluctuant area of skin or chronic recurrent fluid collection is found in a region exposed to a previous shear injury. Clinicians and radiologists should be aware of both the acute and chronic appearances to make the correct diagnosis. Treatment decisions should base on association with fractures, the condition of the lesion, symptom and desire of the patient.

Inter-algorithm lesion volumetry comparison of real and 3D simulated lung lesions in CT

Science.gov (United States)

Robins, Marthony; Solomon, Justin; Hoye, Jocelyn; Smith, Taylor; Ebner, Lukas; Samei, Ehsan

2017-03-01

The purpose of this study was to establish volumetric exchangeability between real and computational lung lesions in CT. We compared the overall relative volume estimation performance of segmentation tools when used to measure real lesions in actual patient CT images and computational lesions virtually inserted into the same patient images (i.e., hybrid datasets). Pathologically confirmed malignancies from 30 thoracic patient cases from Reference Image Database to Evaluate Therapy Response (RIDER) were modeled and used as the basis for the comparison. Lesions included isolated nodules as well as those attached to the pleura or other lung structures. Patient images were acquired using a 16 detector row or 64 detector row CT scanner (Lightspeed 16 or VCT; GE Healthcare). Scans were acquired using standard chest protocols during a single breath-hold. Virtual 3D lesion models based on real lesions were developed in Duke Lesion Tool (Duke University), and inserted using a validated image-domain insertion program. Nodule volumes were estimated using multiple commercial segmentation tools (iNtuition, TeraRecon, Inc., Syngo.via, Siemens Healthcare, and IntelliSpace, Philips Healthcare). Consensus based volume comparison showed consistent trends in volume measurement between real and virtual lesions across all software. The average percent bias (+/- standard error) shows -9.2+/-3.2% for real lesions versus -6.7+/-1.2% for virtual lesions with tool A, 3.9+/-2.5% and 5.0+/-0.9% for tool B, and 5.3+/-2.3% and 1.8+/-0.8% for tool C, respectively. Virtual lesion volumes were statistically similar to those of real lesions (.05 in most cases. Results suggest that hybrid datasets had similar inter-algorithm variability compared to real datasets.

Cellwise conservative unsplit advection for the volume of fluid method

DEFF Research Database (Denmark)

Comminal, Raphaël; Spangenberg, Jon; Hattel, Jesper Henri

2015-01-01

We present a cellwise conservative unsplit (CCU) advection scheme for the volume of fluid method (VOF) in 2D. Contrary to other schemes based on explicit calculations of the flux balances, the CCU advection adopts a cellwise approach where the pre-images of the control volumes are traced......-overlapping donating regions and pre-images with conforming edges to their neighbors, resulting in the conservativeness and the boundedness (liquid volume fraction inside the interval [0, 1]) of the CCU advection scheme. Finally, the update of the liquid volume fractions is computed from the intersections of the pre......-image polygons with the reconstructed interfaces. The CCU scheme is tested on several benchmark tests for the VOF advection, together with the standard piecewise linear interface calculation (PLIC). The geometrical errors of the CCU compare favorably with other unsplit VOF-PLIC schemes. Finally, potential...

Influence of fluid-attenuated inversion-recovery on stroke apparent diffusion coefficient measurements and its clinical application

Energy Technology Data Exchange (ETDEWEB)

Ni Jianming [Medical Imaging Department, Wuxi Second Hospital Affiliated Nanjing Medical University, 68 Zhong Shan Road, Wuxi, Jiangsu Province 214002 (China); Radiology Department, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Urumqi Middle Road, Shanghai 200040 (China); Nuclear Medicine Department, Renji Hospital, Medical School of Jiaotong University, Dongfang Road 1630, Shanghai 200127 (China); Mogensen, Monique A. [Department of Radiology, Division of Neuroradiology, University of Southern California, Los Angeles, CA (United States); Chen Zengai [Radiology Department, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Urumqi Middle Road, Shanghai 200040 (China); Nuclear Medicine Department, Renji Hospital, Medical School of Jiaotong University, Dongfang Road 1630, Shanghai 200127 (China); Shuang Chen; Shen Tianzhen [Radiology Department, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Urumqi Middle Road, Shanghai 200040 (China); Huang Gang, E-mail: huang2802@163.co [Nuclear Medicine Department, Renji Hospital, Medical School of Jiaotong University, Dongfang Road 1630, Shanghai 200127 (China)

2010-08-15

Background and purpose: The application of a fluid-attenuated inversion-recovery pulse with a conventional diffusion-weighted MRI sequence (FLAIR DWI) decreases the partial volume effects from cerebrospinal fluid on apparent diffusion coefficient (ADC) measurements. For this reason, FLAIR DWI may be more useful in the evaluation of ischemic stroke, but few studies have looked at the effect of FLAIR on ADC measurements in this setting. This study quantitatively compares FLAIR DWI and conventional DWI in ischemic stroke of varying ages to assess the potential advantages of this technique. Methods: We respectively analyzed 139 DWI studies in patients with ischemic stroke with and without FLAIR at varying time points ranging from hyperacute to chronic. ADC values were measured in each lesion, as well as in the contralateral normal side. Comparisons were made between the ADC values obtained from the DWI sequences with and without FLAIR for both the lesion and the normal contralateral side. Results: The ADC measurements within the ischemic lesion were very similar on FLAIR DWI and conventional DWI for lesions less than 14 days old (p > 0.05), but were significantly decreased on FLAIR DWI for lesions between 15 and 30 days old and in lesions >31 days old (chronic stage) (p < 0.01). The contralateral ADC values were all significantly decreased on the FLAIR DWI sequence compared with conventional DWI (p < 0.01). Conclusions: The application of an inversion pulse does not significantly affect the ADC values for early stage ischemic stroke (less than 14 days from symptom onset), but results in a more accurate relative ADC measurement by reducing the cerebrospinal fluid partial volume effects of the normal contralateral side. In addition, combined with the conventional DWI, FLAIR DWI may be helpful in determining the age of ischemic lesions.

Fluid Volume Expansion and Depletion in Hemodialysis Patients Lack Association with Clinical Parameters

Directory of Open Access Journals (Sweden)

Sylvia Kalainy

2015-12-01

Full Text Available Background: Achievement of normal volume status is crucial in hemodialysis (HD, since both volume expansion and volume contraction have been associated with adverse outcome and events. Objectives: The objectives of this study are to assess the prevalence of fluid volume expansion and depletion and to identify the best clinical parameter or set of parameters that can predict fluid volume expansion in HD patients. Design: This study is cross-sectional. Setting: This study was conducted in three hemodialysis units. Patients: In this study, there are 194 HD patients. Methods: Volume status was assessed by multifrequency bio-impedance spectroscopy (The Body Composition Monitor, Fresenius prior to the mid-week HD session. Results: Of all patients, 48 % ( n = 94 were volume-expanded and 9 % of patients were volume-depleted ( n = 17. Interdialytic weight gain was not different between hypovolemic, normovolemic, and hypervolemic patients. Fifty percent of the volume-expanded patients were hypertensive. Paradoxical hypertension was very common (31 % of all patients; its incidence was not different between patient groups. Intradialytic hypotension was relatively common and was more frequent among hypovolemic patients. Multivariate regression analysis identified only four predictors for volume expansion (edema, lower BMI, higher SBP, and smoking. None of these parameters displayed both a good sensitivity and specificity. Limitations: The volume assessment was performed once. Conclusions: The study indicates that volume expansion is highly prevalent in HD population and could not be identified using clinical parameters alone. No clinical parameters were identified that could reliably predict volume status. This study shows that bio-impedance can assist to determine volume status. Volume status, in turn, is not related to intradialytic weight gain and is unable to explain the high incidence of paradoxical hypertension.

Fluid mechanics experiments in oscillatory flow. Volume 1

International Nuclear Information System (INIS)

Seume, J.; Friedman, G.; Simon, T.W.

1992-03-01

Results of a fluid mechanics measurement program is oscillating flow within a circular duct are present. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re max , Re W , and A R , embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA's Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radical components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and in reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. The following is presented in two-volumes. Volume I contains the text of the report including figures and supporting appendices. Volume II contains data reduction program listings and tabulated data (including its graphical presentation)

Systems and methods for the detection of low-level harmful substances in a large volume of fluid

Science.gov (United States)

Carpenter, Michael V.; Roybal, Lyle G.; Lindquist, Alan; Gallardo, Vincente

2016-03-15

A method and device for the detection of low-level harmful substances in a large volume of fluid comprising using a concentrator system to produce a retentate and analyzing the retentate for the presence of at least one harmful substance. The concentrator system performs a method comprising pumping at least 10 liters of fluid from a sample source through a filter. While pumping, the concentrator system diverts retentate from the filter into a container. The concentrator system also recirculates at least part of the retentate in the container again through the filter. The concentrator system controls the speed of the pump with a control system thereby maintaining a fluid pressure less than 25 psi during the pumping of the fluid; monitors the quantity of retentate within the container with a control system, and maintains a reduced volume level of retentate and a target volume of retentate.

Dehydration and fluid volume kinetics before major open abdominal surgery.

Science.gov (United States)

Hahn, R G; Bahlmann, H; Nilsson, L

2014-11-01

Assessment of dehydration in the preoperative setting is of potential clinical value. The present study uses urine analysis and plasma volume kinetics, which have both been validated against induced changes in body water in volunteers, to study the incidence and severity of dehydration before open abdominal surgery begins. Thirty patients (mean age 64 years) had their urine analysed before major elective open abdominal surgery for colour, specific weight, osmolality and creatinine. The results were scored and the mean taken to represent a 'dehydration index'. Thereafter, the patients received an infusion of 5 ml/kg of Ringer's acetate intravenously for over 15 min. Blood was sampled for 70 min and the blood haemoglobin concentration used to estimate the plasma volume kinetics. Distribution of fluid occurred more slowly (P dehydrated as compared with euhydrated patients. The dehydration index indicated that the fluid deficit in these patients corresponded to 2.5% of the body weight, whereas the deficit in the others was 1%. In contrast, the 11 patients who later developed postoperative nausea and vomiting had a very short elimination half-life, only 9 min (median, P dehydration before major surgery was modest as evidenced both by urine sampling and volume kinetic analysis. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Association of Cortical Lesion Burden on 7-T Magnetic Resonance Imaging With Cognition and Disability in Multiple Sclerosis.

Science.gov (United States)

Harrison, Daniel M; Roy, Snehashis; Oh, Jiwon; Izbudak, Izlem; Pham, Dzung; Courtney, Susan; Caffo, Brian; Jones, Craig K; van Zijl, Peter; Calabresi, Peter A

2015-09-01

Cortical lesions (CLs) contribute to physical and cognitive disability in multiple sclerosis (MS). Accurate methods for visualization of CLs are necessary for future clinical studies and therapeutic trials in MS. To evaluate the clinical relevance of measures of CL burden derived from high-field magnetic resonance imaging (MRI) in MS. An observational clinical imaging study was conducted at an academic MS center. Participants included 36 individuals with MS (30 relapsing-remitting, 6 secondary or primary progressive) and 15 healthy individuals serving as controls. The study was conducted from March 10, 2010, to November 23, 2012, and analysis was performed from June 1, 2011, to September 30, 2014. Seven-Tesla MRI of the brain was performed with 0.5-mm isotropic resolution magnetization-prepared rapid acquisition gradient echo (MPRAGE) and whole-brain, 3-dimensional, 1.0-mm isotropic resolution magnetization-prepared, fluid-attenuated inversion recovery (MPFLAIR). Cortical lesions, seen as hypointensities on MPRAGE, were manually segmented. Lesions were classified as leukocortical, intracortical, or subpial. Images were segmented using the Lesion-TOADS (Topology-Preserving Anatomical Segmentation) algorithm, and brain structure volumes and white matter (WM) lesion volume were reported. Volumes were normalized to intracranial volume. Physical disability was measured by the Expanded Disability Status Scale (EDSS). Cognitive disability was measured with the Minimal Assessment of Cognitive Function in MS battery. Cortical lesions were noted in 35 of 36 participants (97%), with a median of 16 lesions per participant (range, 0-99). Leukocortical lesion volume correlated with WM lesion volume (ρ = 0.50; P = .003) but not with cortical volume; subpial lesion volume inversely correlated with cortical volume (ρ = -0.36; P = .04) but not with WM lesion volume. Total CL count and volume, measured as median (range), were significantly increased in participants

OK-432 sclerotherapy for benign cystic head and neck lesions

International Nuclear Information System (INIS)

Kim, Chang Hyun; Rho, Myung Ho; Lee, Sang Wook

2003-01-01

To evaluate the efficacy of OK-432 solution for slerotheraphy of cystic lesions of the head and neck. Nineteen cystic lesions comprising ten plunging ranulas, three simple ranulas, three cystic lymphangiomas, one first branchial cleft cyst and two unknown supraclavicular cysts considered to be lymphangiomas were treated by sucking out as much liquid content as possible and then injecting the same volume of OK-432 solution under ultrasound guidance. Patients were followed up clinically and radiologically. Follow-up sonography or CT- performed after a mean interval of nine months showed total or near-total shrinkage of four plunging ranulas. However, six such lesions recurred in spite of more than one (mean, two) sclerotherapy sessions. In cases involving two simple ranulas at the floor of the mouth, failure resulted from extracystic leakage of OK-432 solution via the puncture site. Two unilocular cystic lymphangiomas completely regressed during the follow-up period (mean, seven months), but the multiocular type showed a 65% volume reduction after 12 months. A first branchial cleft cyst was markedly reduced in size, with only a small cystic portion remaining after eight months, follow-up. Two supraclavicular cysts with straw-color fluid did not respond to sclerotherapy. OK-432 sclerotherapy of macrocystic lymphangiomas is an effective and promising alternative to surgery. For other cysts, however, including plunging ranula, efficacy, varied, and 64% of such lesions recurred

OK-432 sclerotherapy for benign cystic head and neck lesions

Energy Technology Data Exchange (ETDEWEB)

Kim, Chang Hyun; Rho, Myung Ho; Lee, Sang Wook [Masan Samsung Hospital, Masan (Korea, Republic of)

2003-12-01

To evaluate the efficacy of OK-432 solution for slerotheraphy of cystic lesions of the head and neck. Nineteen cystic lesions comprising ten plunging ranulas, three simple ranulas, three cystic lymphangiomas, one first branchial cleft cyst and two unknown supraclavicular cysts considered to be lymphangiomas were treated by sucking out as much liquid content as possible and then injecting the same volume of OK-432 solution under ultrasound guidance. Patients were followed up clinically and radiologically. Follow-up sonography or CT- performed after a mean interval of nine months showed total or near-total shrinkage of four plunging ranulas. However, six such lesions recurred in spite of more than one (mean, two) sclerotherapy sessions. In cases involving two simple ranulas at the floor of the mouth, failure resulted from extracystic leakage of OK-432 solution via the puncture site. Two unilocular cystic lymphangiomas completely regressed during the follow-up period (mean, seven months), but the multiocular type showed a 65% volume reduction after 12 months. A first branchial cleft cyst was markedly reduced in size, with only a small cystic portion remaining after eight months, follow-up. Two supraclavicular cysts with straw-color fluid did not respond to sclerotherapy. OK-432 sclerotherapy of macrocystic lymphangiomas is an effective and promising alternative to surgery. For other cysts, however, including plunging ranula, efficacy, varied, and 64% of such lesions recurred.

Bubble formation in shear-thinning fluids: Laser image measurement and a novel correlation for detached volume

Directory of Open Access Journals (Sweden)

Fan Wenyuan

2017-01-01

Full Text Available A laser image system has been established to quantify the characteristics of growing bubbles in quiescent shear-thinning fluids. Bubble formation mechanism was investigated by comparing the evolutions of bubble instantaneous shape, volume and surface area in two shear-thinning liquids with those in Newtonian liquid. The effects of solution mass concentration, gas chamber volume and orifice diameter on bubble detachment volume are discussed. By dimensional analysis, a single bubble volume detached within a moderate gas flowrate range was developed as a function of Reynolds number ,Re, Weber number, We, and gas chamber number, Vc, based on the orifice diameter. The results reveal that the generated bubble presents a slim shape due to the shear-thinning effect of the fluid. Bubble detachment volume increases with the solution mass concentration, gas chamber volume and orifice diameter. The results predicted by the present correlation agree better with the experimental data than the previous ones within the range of this paper.

Elevated interstitial fluid volume in rat soleus muscles by hindlimb unweighting

DEFF Research Database (Denmark)

Kandarian, S C; Boushel, Robert Christopher; Schulte, Lars

1991-01-01

) by tail suspension. Soleus muscles were studied after 28 days and compared with those from five age-matched control (C) rats. Interstitial fluid volume ([3H]inulin space) and maximum tetanic tension (Po) were measured in vitro at 25 degrees C. Soleus muscles atrophied 58% because of unweighting (C = 147...

Modelling dynamic liquid-gas systems: Extensions to the volume-of-fluid solver

CSIR Research Space (South Africa)

Heyns, Johan A

2013-06-01

Full Text Available This study presents the extension of the volume-of-fluid solver, interFoam, for improved accuracy and efficiency when modelling dynamic liquid-gas systems. Examples of these include the transportation of liquids, such as in the case of fuel carried...

Effect of fluid loading with normal saline and 6% hydroxyethyl starch on stroke volume variability and left ventricular volume

Directory of Open Access Journals (Sweden)

Kanda H

2015-09-01

Full Text Available Hirotsugu Kanda,1 Yuji Hirasaki,2 Takafumi Iida,1 Megumi Kanao,1 Yuki Toyama,1 Takayuki Kunisawa,1 Hiroshi Iwasaki,11Department of Anesthesiology and Critical Care Medicine, Asahikawa Medical University, Asahikawa, 2Department of Anatomy, The Jikei University Graduate School of Medicine, Tokyo, JapanPurpose: The aim of this clinical trial was to investigate changes in stroke volume variability (SVV and left ventricular end-diastolic volume (LVEDV after a fluid bolus of crystalloid or colloid using real-time three-dimensional transesophageal echocardiography (3D-TEE and the Vigileo-FloTrac™ system.Materials and methods: After obtaining Institutional Review Board approval, and informed consent from the research participants, 22 patients undergoing scheduled peripheral vascular bypass surgery were enrolled in the study. The patients were randomly assigned to receive 500 mL of hydroxyethyl starch (HES; HES group, n=11 or normal saline (Saline group, n=11 for fluid replacement therapy. SVV was measured using the Vigileo-FloTrac system. LVEDV, stroke volume, and cardiac output were measured by 3D-TEE. The measurements were performed over 30 minutes before and after the fluid bolus in both groups.Results: SVV significantly decreased after fluid bolus in both groups (HES group, 14.7%±2.6% to 6.9%±2.7%, P<0.001; Saline group, 14.3%±3.9% to 8.8%±3.1%, P<0.001. LVEDV significantly increased after fluid loading in the HES group (87.1±24.0 mL to 99.9±27.2 mL, P<0.001, whereas no significant change was detected in the Saline group (88.8±17.3 mL to 91.4±17.6 mL, P>0.05. Stroke volume significantly increased after infusion in the HES group (50.6±12.5 mL to 61.6±19.1 mL, P<0.01 but not in the Saline group (51.6±13.4 mL to 54.1±12.8 mL, P>0.05. Cardiac output measured by 3D-TEE significantly increased in the HES group (3.5±1.1 L/min to 3.9±1.3 L/min, P<0.05, whereas no significant change was seen in the Saline group (3.4±1.1 L/min to 3.3±1.0 L

Extravascular Lung Water Does Not Increase in Hypovolemic Patients after a Fluid-Loading Protocol Guided by the Stroke Volume Variation

Directory of Open Access Journals (Sweden)

Carlos Ferrando

2012-01-01

Full Text Available Introduction. Circulatory failure secondary to hypovolemia is a common situation in critical care patients. Volume replacement is the first option for the treatment of hypovolemia. A possible complication of volume loading is pulmonary edema, quantified at the bedside by the measurement of extravascular lung water index (ELWI. ELWI predicts progression to acute lung injury (ALI in patients with risk factors for developing it. The aim of this study was to assess whether fluid loading guided by the stroke volume variation (SVV, in patients presumed to be hypovolemic, increased ELWI or not. Methods. Prospective study of 17 consecutive postoperative, fully mechanically ventilated patients diagnosed with circulatory failure secondary to presumed hypovolemia were included. Cardiac index (CI, ELWI, SVV, and global end-diastolic volume index (GEDI were determined using the transpulmonary thermodilution technique during the first 12 hours after fluid loading. Volume replacement was done with a strict hemodynamic protocol. Results. Fluid loading produced a significant increase in CI and a decrease in SVV. ELWI did not increase. No correlation was found between the amount of fluids administered and the change in ELWI. Conclusion. Fluid loading guided by SVV in hypovolemic and fully mechanically ventilated patients in sinus rhythm does not increase ELWI.

Numerical simulation of bubble deformation in magnetic fluids by finite volume method

International Nuclear Information System (INIS)

Yamasaki, Haruhiko; Yamaguchi, Hiroshi

2017-01-01

Bubble deformation in magnetic fluids under magnetic field is investigated numerically by an interface capturing method. The numerical method consists of a coupled level-set and VOF (Volume of Fluid) method, combined with conservation CIP (Constrained Interpolation Profile) method with the self-correcting procedure. In the present study considering actual physical properties of magnetic fluid, bubble deformation under given uniform magnetic field is analyzed for internal magnetic field passing through a magnetic gaseous and liquid phase interface. The numerical results explain the mechanism of bubble deformation under presence of given magnetic field. - Highlights: • A magnetic field analysis is developed to simulate the bubble dynamics in magnetic fluid with two-phase interface. • The elongation of bubble increased with increasing magnetic flux intensities due to strong magnetic normal force. • Proposed technique explains the bubble dynamics, taking into account of the continuity of the magnetic flux density.

FLAIR lesion segmentation: Application in patients with brain tumors and acute ischemic stroke

International Nuclear Information System (INIS)

Artzi, Moran; Aizenstein, Orna; Jonas-Kimchi, Tali; Myers, Vicki; Hallevi, Hen; Ben Bashat, Dafna

2013-01-01

Background: Lesion size in fluid attenuation inversion recovery (FLAIR) images is an important clinical parameter for patient assessment and follow-up. Although manual delineation of lesion areas considered as ground truth, it is time-consuming, highly user-dependent and difficult to perform in areas of indistinct borders. In this study, an automatic methodology for FLAIR lesion segmentation is proposed, and its application in patients with brain tumors undergoing therapy; and in patients following stroke is demonstrated. Materials and methods: FLAIR lesion segmentation was performed in 57 magnetic resonance imaging (MRI) data sets obtained from 44 patients: 28 patients with primary brain tumors; 5 patients with recurrent-progressive glioblastoma (rGB) who were scanned longitudinally during anti-angiogenic therapy (18 MRI scans); and 11 patients following ischemic stroke. Results: FLAIR lesion segmentation was obtained in all patients. When compared to manual delineation, a high visual similarity was observed, with an absolute relative volume difference of 16.80% and 20.96% and a volumetric overlap error of 24.87% and 27.50% obtained for two raters: accepted values for automatic methods. Quantitative measurements of the segmented lesion volumes were in line with qualitative radiological assessment in four patients who received anti-anogiogenic drugs. In stroke patients the proposed methodology enabled identification of the ischemic lesion and differentiation from other FLAIR hyperintense areas, such as pre-existing disease. Conclusion: This study proposed a replicable methodology for FLAIR lesion detection and quantification and for discrimination between lesion of interest and pre-existing disease. Results from this study show the wide clinical applications of this methodology in research and clinical practice

FLAIR lesion segmentation: Application in patients with brain tumors and acute ischemic stroke

Energy Technology Data Exchange (ETDEWEB)

Artzi, Moran, E-mail: artzimy@gmail.com [The Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Aizenstein, Orna, E-mail: ornaaize@gmail.com [The Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Jonas-Kimchi, Tali, E-mail: talijk@tlvmc.gov.il [Radiology Department, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Myers, Vicki, E-mail: vicki_myers@hotmail.com [The Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Hallevi, Hen, E-mail: hen.hallevi@gmail.com [Neurology Department, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Ben Bashat, Dafna, E-mail: dafnab@tlvmc.gov.il [The Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel)

2013-09-15

Background: Lesion size in fluid attenuation inversion recovery (FLAIR) images is an important clinical parameter for patient assessment and follow-up. Although manual delineation of lesion areas considered as ground truth, it is time-consuming, highly user-dependent and difficult to perform in areas of indistinct borders. In this study, an automatic methodology for FLAIR lesion segmentation is proposed, and its application in patients with brain tumors undergoing therapy; and in patients following stroke is demonstrated. Materials and methods: FLAIR lesion segmentation was performed in 57 magnetic resonance imaging (MRI) data sets obtained from 44 patients: 28 patients with primary brain tumors; 5 patients with recurrent-progressive glioblastoma (rGB) who were scanned longitudinally during anti-angiogenic therapy (18 MRI scans); and 11 patients following ischemic stroke. Results: FLAIR lesion segmentation was obtained in all patients. When compared to manual delineation, a high visual similarity was observed, with an absolute relative volume difference of 16.80% and 20.96% and a volumetric overlap error of 24.87% and 27.50% obtained for two raters: accepted values for automatic methods. Quantitative measurements of the segmented lesion volumes were in line with qualitative radiological assessment in four patients who received anti-anogiogenic drugs. In stroke patients the proposed methodology enabled identification of the ischemic lesion and differentiation from other FLAIR hyperintense areas, such as pre-existing disease. Conclusion: This study proposed a replicable methodology for FLAIR lesion detection and quantification and for discrimination between lesion of interest and pre-existing disease. Results from this study show the wide clinical applications of this methodology in research and clinical practice.

Unmasking a sustained negative effect of SGLT2 inhibition on body fluid volume in the rat.

Science.gov (United States)

Masuda, Takahiro; Watanabe, Yuko; Fukuda, Keiko; Watanabe, Minami; Onishi, Akira; Ohara, Ken; Imai, Toshimi; Koepsell, Hermann; Muto, Shigeaki; Vallon, Volker; Nagata, Daisuke

2018-05-23

The chronic intrinsic diuretic and natriuretic tone of sodium-glucose cotransporter 2 (SGLT2) inhibitors is incompletely understood, because their effect on body fluid volume (BFV) has not been fully evaluated and because they often increase food and fluid intake at the same time. Here we first compared the effect of the SGLT2 inhibitor ipragliflozin (Ipra, 0.01% in diet for 8 weeks) and vehicle (Veh) in Spontaneously Diabetic Torii rat, a non-obese type 2 diabetic model, and non-diabetic Sprague-Dawley rats. In non-diabetic rats, Ipra increased urinary excretion of Na+ (UNaV) and fluid (UV) associated with increased food and fluid intake. Diabetes increased these 4 parameters, but Ipra had no further effect; probably due to its antihyperglycemic effect, such that glucosuria and as a consequence food and fluid intake were unchanged. Fluid balance and BFV, determined by bioimpedance spectroscopy, were similar among the 4 groups. To study the impact of food and fluid intake, non-diabetic rats were treated for 7 days with Veh, Ipra or Ipra+pair-feeding+pair-drinking (Pair-Ipra). Pair-Ipra maintained a small increase in UV and UNaV versus Veh despite similar food and fluid intake. Pair-Ipra induced a negative fluid balance and decreased BFV, while Ipra or Veh had no significant effect compared with basal values. In conclusion, SGLT2 inhibition induces a sustained diuretic and natriuretic tone. Homeostatic mechanisms are activated to stabilize body fluid volume, including compensatory increases in fluid and food intake.

Viscosity Prediction for Petroleum Fluids Using Free Volume Theory and PC-SAFT

Science.gov (United States)

Khoshnamvand, Younes; Assareh, Mehdi

2018-04-01

In this study, free volume theory ( FVT) in combination with perturbed-chain statistical associating fluid theory is implemented for viscosity prediction of petroleum reservoir fluids containing ill-defined components such as cuts and plus fractions. FVT has three adjustable parameters for each component to calculate viscosity. These three parameters for petroleum cuts (especially plus fractions) are not available. In this work, these parameters are determined for different petroleum fractions. A model as a function of molecular weight and specific gravity is developed using 22 real reservoir fluid samples with API grades in the range of 22 to 45. Afterward, the proposed model accuracy in comparison with the accuracy of De la Porte et al. with reference to experimental data is presented. The presented model is used for six real samples in an evaluation step, and the results are compared with available experimental data and the method of De la Porte et al. Finally, the method of Lohrenz et al. and the method of Pedersen et al. as two common industrial methods for viscosity calculation are compared with the proposed approach. The absolute average deviation was 9.7 % for free volume theory method, 15.4 % for Lohrenz et al., and 22.16 for Pedersen et al.

Special issue: Terrestrial fluids, earthquakes and volcanoes: The Hiroshi Wakita volume I

Science.gov (United States)

Perez, Nemesio M.; King, Chi-Yu; Gurrieri, Sergio; McGee, Kenneth A.

2006-01-01

Terrestrial Fluids, Earthquakes and Volcanoes: The Hiroshi Wakita Volume I is a special publication to honor Professor Hiroshi Wakita for his scientific contributions. This volume consists of 17 original papers dealing with various aspects of the role of terrestrial fluids in earthquake and volcanic processes, which reflect Prof. Wakita’s wide scope of research interests.Professor Wakita co-founded the Laboratory for Earthquake Chemistry in 1978 and served as its director from 1988 until his retirement from the university in 1997. He has made the laboratory a leading world center for studying earthquakes and volcanic activities by means of geochemical and hydrological methods. Together with his research team and a number of foreign guest researchers that he attracted, he has made many significant contributions in the above-mentioned scientific fields of interest. This achievement is a testimony to not only his scientific talent, but also his enthusiasm, his open mindedness, and his drive in obtaining both human and financial support.

Diagnostic accuracy of the defining characteristics of the excessive fluid volume diagnosis in hemodialysis patients

Directory of Open Access Journals (Sweden)

Maria Isabel da Conceição Dias Fernandes

2015-12-01

Full Text Available Objective: to evaluate the accuracy of the defining characteristics of the excess fluid volume nursing diagnosis of NANDA International, in patients undergoing hemodialysis. Method: this was a study of diagnostic accuracy, with a cross-sectional design, performed in two stages. The first, involving 100 patients from a dialysis clinic and a university hospital in northeastern Brazil, investigated the presence and absence of the defining characteristics of excess fluid volume. In the second step, these characteristics were evaluated by diagnostic nurses, who judged the presence or absence of the diagnosis. To analyze the measures of accuracy, sensitivity, specificity, and positive and negative predictive values were calculated. Approval was given by the Research Ethics Committee under authorization No. 148.428. Results: the most sensitive indicator was edema and most specific were pulmonary congestion, adventitious breath sounds and restlessness. Conclusion: the more accurate defining characteristics, considered valid for the diagnostic inference of excess fluid volume in patients undergoing hemodialysis were edema, pulmonary congestion, adventitious breath sounds and restlessness. Thus, in the presence of these, the nurse may safely assume the presence of the diagnosis studied.

Magnetic fluid axisymmetric volume on a horizontal plane near a vertical line conductor in case of non-wetting

Energy Technology Data Exchange (ETDEWEB)

Vinogradova, A.S., E-mail: vinogradova.msu@gmail.com; Turkov, V.A.; Naletova, V.A.

2017-06-01

Static shapes of a magnetic fluid axisymmetric volume on a horizontal plane in the magnetic field of a vertical line conductor are studied theoretically in case of non-wetting while the current is slowly changing in a quasi-static manner. The possibility of the fluid shape hysteresis for a cyclic increase and decrease of the current and of spasmodic changes at certain values of the current is investigated. - Highlights: • Magnetic fluid on a horizontal plane near a line conductor is studied theoretically. • For fixed current and volume various static shapes are obtained. • Spasmodic and hysteresis phenomena are found.

Effect of Volume of Fluid Resuscitation on Metabolic Normalization in Children Presenting in Diabetic Ketoacidosis: A Randomized Controlled Trial.

Science.gov (United States)

Bakes, Katherine; Haukoos, Jason S; Deakyne, Sara J; Hopkins, Emily; Easter, Josh; McFann, Kim; Brent, Alison; Rewers, Arleta

2016-04-01

The optimal rate of fluid administration in pediatric diabetic ketoacidosis (DKA) is unknown. Our aim was to determine whether the volume of fluid administration in children with DKA influences the rate of metabolic normalization. We performed a randomized controlled trial conducted in a tertiary pediatric emergency department from December 2007 until June 2010. The primary outcome was time to metabolic normalization; secondary outcomes were time to bicarbonate normalization, pH normalization, overall length of hospital treatment, and adverse outcomes. Children between 0 and 18 years of age were eligible if they had type 1 diabetes mellitus and DKA. Patients were randomized to receive intravenous (IV) fluid at low volume (10 mL/kg bolus + 1.25 × maintenance rate) or high volume (20 mL/kg bolus + 1.5 × maintenance rate) (n = 25 in each). After adjusting for initial differences in bicarbonate levels, time to metabolic normalization was significantly faster in the higher-volume infusion group compared to the low-volume infusion group (hazard ratio [HR] = 2.0; 95% confidence interval [CI] 1.0-3.9; p = 0.04). Higher-volume IV fluid infusion appeared to hasten, to a greater extent, normalization of pH (HR = 2.5; 95% CI 1.2-5.0; p = 0.01) than normalization of serum bicarbonate (HR = 1.2; 95% CI 0.6-2.3; p = 0.6). The length of hospital treatment HR (0.8; 95% CI 0.4-1.5; p = 0.5) and time to discharge HR (0.8; 95% CI 0.4-1.5; p = 0.5) did not differ between treatment groups. Higher-volume fluid infusion in the treatment of pediatric DKA patients significantly shortened metabolic normalization time, but did not change overall length of hospital treatment. ClinicalTrials.gov ID NCT01701557. Copyright © 2016 Elsevier Inc. All rights reserved.

Measurement of average density and relative volumes in a dispersed two-phase fluid

Science.gov (United States)

Sreepada, Sastry R.; Rippel, Robert R.

1992-01-01

An apparatus and a method are disclosed for measuring the average density and relative volumes in an essentially transparent, dispersed two-phase fluid. A laser beam with a diameter no greater than 1% of the diameter of the bubbles, droplets, or particles of the dispersed phase is directed onto a diffraction grating. A single-order component of the diffracted beam is directed through the two-phase fluid and its refraction is measured. Preferably, the refracted beam exiting the fluid is incident upon a optical filter with linearly varing optical density and the intensity of the filtered beam is measured. The invention can be combined with other laser-based measurement systems, e.g., laser doppler anemometry.

A Finite-Volume computational mechanics framework for multi-physics coupled fluid-stress problems

International Nuclear Information System (INIS)

Bailey, C; Cross, M.; Pericleous, K.

1998-01-01

Where there is a strong interaction between fluid flow, heat transfer and stress induced deformation, it may not be sufficient to solve each problem separately (i.e. fluid vs. stress, using different techniques or even different computer codes). This may be acceptable where the interaction is static, but less so, if it is dynamic. It is desirable for this reason to develop software that can accommodate both requirements (i.e. that of fluid flow and that of solid mechanics) in a seamless environment. This is accomplished in the University of Greenwich code PHYSICA, which solves both the fluid flow problem and the stress-strain equations in a unified Finite-Volume environment, using an unstructured computational mesh that can deform dynamically. Example applications are given of the work of the group in the metals casting process (where thermal stresses cause elasto- visco-plastic distortion)

Numerical solution of viscous and viscoelastic fluids flow through the branching channel by finite volume scheme

Science.gov (United States)

Keslerová, Radka; Trdlička, David

2015-09-01

This work deals with the numerical modelling of steady flows of incompressible viscous and viscoelastic fluids through the three dimensional channel with T-junction. The fundamental system of equations is the system of generalized Navier-Stokes equations for incompressible fluids. This system is based on the system of balance laws of mass and momentum for incompressible fluids. Two different mathematical models for the stress tensor are used for simulation of Newtonian and Oldroyd-B fluids flow. Numerical solution of the described models is based on cetral finite volume method using explicit Runge-Kutta time integration.

Maintenance fluid therapy and fluid creep impose more significant fluid, sodium, and chloride burdens than resuscitation fluids in critically ill patients: a retrospective study in a tertiary mixed ICU population.

Science.gov (United States)

Van Regenmortel, Niels; Verbrugghe, Walter; Roelant, Ella; Van den Wyngaert, Tim; Jorens, Philippe G

2018-04-01

Research on intravenous fluid therapy and its side effects, volume, sodium, and chloride overload, has focused almost exclusively on the resuscitation setting. We aimed to quantify all fluid sources in the ICU and assess fluid creep, the hidden and unintentional volume administered as a vehicle for medication or electrolytes. We precisely recorded the volume, sodium, and chloride burdens imposed by every fluid source administered to 14,654 patients during the cumulative 103,098 days they resided in our 45-bed tertiary ICU and simulated the impact of important strategic fluid choices on patients' chloride burdens. In septic patients, we assessed the impact of the different fluid sources on cumulative fluid balance, an established marker of morbidity. Maintenance and replacement fluids accounted for 24.7% of the mean daily total fluid volume, thereby far exceeding resuscitation fluids (6.5%) and were the most important sources of sodium and chloride. Fluid creep represented a striking 32.6% of the mean daily total fluid volume [median 645 mL (IQR 308-1039 mL)]. Chloride levels can be more effectively reduced by adopting a hypotonic maintenance strategy [a daily difference in chloride burden of 30.8 mmol (95% CI 30.5-31.1)] than a balanced resuscitation strategy [daily difference 3.0 mmol (95% CI 2.9-3.1)]. In septic patients, non-resuscitation fluids had a larger absolute impact on cumulative fluid balance than did resuscitation fluids. Inadvertent daily volume, sodium, and chloride loading should be avoided when prescribing maintenance fluids in view of the vast amounts of fluid creep. This is especially important when adopting an isotonic maintenance strategy.

Amniotic fluid volume: Rapid MR-based assessment at 28-32 weeks gestation

Energy Technology Data Exchange (ETDEWEB)

Hilliard, N.J.; Hawkes, R.; Patterson, A.J.; Graves, M.J.; Priest, A.N.; Hunter, S.; Set, P.A.; Lomas, D.J. [Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Cambridge (United Kingdom); Lees, C. [Imperial College Healthcare NHS Trust, Department of Obstetrics and Fetal Medicine, London (United Kingdom)

2016-10-15

This work evaluates rapid magnetic resonance projection hydrography (PH) based amniotic fluid volume (AFV) estimates against established routine ultrasound single deepest vertical pocket (SDVP) and amniotic fluid index (AFI) measurements, in utero at 28-32 weeks gestation. Manual multi-section planimetry (MSP) based measurement of AFV is used as a proxy reference standard. Thirty-five women with a healthy singleton pregnancy (20-41 years) attending routine antenatal ultrasound were recruited. SDVP and AFI were measured using ultrasound, with same day MRI assessing AFV with PH and MSP. The relationships between the respective techniques were assessed using linear regression analysis and Bland-Altman method comparison statistics. When comparing estimated AFV, a highly significant relationship was observed between PH and the reference standard MSP (R{sup 2} = 0.802, p < 0.001). For the US measurements, SDVP measurement related most closely to amniotic fluid volume, (R{sup 2} = 0.470, p < 0.001), with AFI demonstrating a weaker relationship (R{sup 2} = 0.208, p = 0.007). This study shows that rapid MRI based PH measurement is a better predictor of AFV, relating more closely to our proxy standard than established US techniques. Although larger validation studies across a range of gestational ages are required this approach could form part of MR fetal assessment, particularly where poly- or oligohydramnios is suspected. (orig.)

Amniotic fluid volume: Rapid MR-based assessment at 28-32 weeks gestation

International Nuclear Information System (INIS)

Hilliard, N.J.; Hawkes, R.; Patterson, A.J.; Graves, M.J.; Priest, A.N.; Hunter, S.; Set, P.A.; Lomas, D.J.; Lees, C.

2016-01-01

This work evaluates rapid magnetic resonance projection hydrography (PH) based amniotic fluid volume (AFV) estimates against established routine ultrasound single deepest vertical pocket (SDVP) and amniotic fluid index (AFI) measurements, in utero at 28-32 weeks gestation. Manual multi-section planimetry (MSP) based measurement of AFV is used as a proxy reference standard. Thirty-five women with a healthy singleton pregnancy (20-41 years) attending routine antenatal ultrasound were recruited. SDVP and AFI were measured using ultrasound, with same day MRI assessing AFV with PH and MSP. The relationships between the respective techniques were assessed using linear regression analysis and Bland-Altman method comparison statistics. When comparing estimated AFV, a highly significant relationship was observed between PH and the reference standard MSP (R"2 = 0.802, p < 0.001). For the US measurements, SDVP measurement related most closely to amniotic fluid volume, (R"2 = 0.470, p < 0.001), with AFI demonstrating a weaker relationship (R"2 = 0.208, p = 0.007). This study shows that rapid MRI based PH measurement is a better predictor of AFV, relating more closely to our proxy standard than established US techniques. Although larger validation studies across a range of gestational ages are required this approach could form part of MR fetal assessment, particularly where poly- or oligohydramnios is suspected. (orig.)

Difficulty of MRI based identification of lesion age by acute infra-tentorial ischemic stroke.

Directory of Open Access Journals (Sweden)

Florian Grosse-Dresselhaus

Full Text Available Systemic thrombolysis in acute ischemic stroke is restricted to the 4.5 h time window. Many patients are excluded from this treatment because symptom onset is unknown. Magnetic resonance imaging (MRI studies have shown that stroke patients presenting with acute supra-tentorial diffusion-weighted imaging (DWI lesions that do not have matching lesions on fluid attenuated inversion recovery (FLAIR are likely to be within a 4.5 hour time window. This study examines the DWI-FLAIR mismatch in infra-tentorial stroke.This was a retrospectively conducted substudy of the "1000+" study; a prospective, single-center observational study (http://clinicaltrials.gov; NCT00715533. Fifty-six patients with infra-tentorial stroke confirmed by MRI and known symptom onset who underwent the scan within 24 h after symptom onset were analysed. Two neurologists blinded to clinical information separately rated the DWI lesion visibility on FLAIR. Lesion volume, relative signal intensities of DWI and relative apparent diffusion coefficient values were determined.Regarding baseline characteristics our study population had a median age of 66 years, a median time from symptom onset to MRI of 616.5 minutes, a median NIHSS of 3 and a median DWI lesion volume of 0.26 ml. A negative FLAIR allocated patients to a time window under 4.5 h correctly with a sensitivity of 55% and a specificity of 61%, a positive predictive value of 44% and a negative predictive value of 71%. FLAIR positivity decreased with age (p = 0.018, and showed no significant correlation to lesion volume (p = 0.145.In our study the DWI-FLAIR-Mismatch does not help to reliably identify patients within 4.5 h of symptom onset in acute ischemic infra-tentorial stroke. Thus therapeutical decisions based on the DWI-FLAIR mismatch estimation of time from onset cannot be recommended in patients with infra-tentorial stroke.

Mechanisms underlying the volume regulation of interstitial fluid by capillaries: a simulation study

Directory of Open Access Journals (Sweden)

Yukiko Himeno

2016-03-01

Conclusion: Mathematical analyses revealed that the system of the capillary is stable near the equilibrium point at steady state and normal physiological capillary pressure. The time course of the tissue-volume change was determined by two kinetic mechanisms: rapid fluid exchange and slow protein fluxes.

T1-weighted fluid-attenuated inversion recovery and T1-weighted fast spin-echo contrast-enhanced imaging: a comparison in 20 patients with brain lesions

International Nuclear Information System (INIS)

Al-Saeed, O.; Athyal, R. P.; Ismail, M.; Rudwan, M.; Khafajee, S.

2009-01-01

Full text: Tl-weighted fluid-attenuated inversion recovery (FLAIR) sequence is a relatively new pulse sequence for intracranial MR imaging. This study was performed to compare the image quality of Tl-weighted FLAIR with the Tl-weighted FSE sequence. Twenty patients with brain lesions underwent Tl-weighted fast spin-echo (FSE) and Tl-weighted FLAIR during the same imaging session. Four quantitative and three qualitative criteria were used to compare the two sequences after contrast. Two of four quantitative criteria pertained to lesion characteristics: lesion to white matter (WM) contrast-to-noise ratio (CNR) and lesion to cerebrospinal fluid (CSF) CNR, and two related to signals from normal tissue: grey matter to WM CNR and WM to CSF CNR. The three qualitative criteria were conspicuousness of the lesion, the presence of image artefacts and the overall image contrast. Both Tl-weighted FSE and FLAIR images were effective in demonstrating lesions. Image contrast was superior in Tl-weighted FLAIR images with significantly improved grey matter-WM CNRs and CSF-WM CNRs. The overall image contrast was judged to be superior on Tl-weighted FLAIR images compared with Tl-weighted FSE images by all neuroradiologists. Two of three reviewers considered that the FLAIR images had slightly increased imaging artefacts that, however, did not interfere with image interpretation. Tl-weighted FLAIR imaging provides improved lesion-to-background and grey to WM contrast-to-noise ratios. Superior conspicuity of lesions and overall image contrast is obtained in comparable acquisition times. These indicate an important role for Tl-weighted FLAIR in intracranial imaging and highlight its advantage over the more widely practiced Tl-weighted FSE sequence

Gastric pH and residual volume after 1 and 2 h fasting time for clear fluids in children†.

Science.gov (United States)

Schmidt, A R; Buehler, P; Seglias, L; Stark, T; Brotschi, B; Renner, T; Sabandal, C; Klaghofer, R; Weiss, M; Schmitz, A

2015-03-01

Current guidelines suggest a fasting time of 2 h for clear fluids, which is often exceeded in clinical practice, leading to discomfort, dehydration and stressful anaesthesia induction to patients, especially in the paediatric population. Shorter fluid fasting might be a strategy to improve patient comfort but has not been investigated yet. This prospective clinical trial compares gastric pH and residual volume after 1 vs 2 h of preoperative clear fluid fasting. Children (1-16 yr, ASA I or II) undergoing elective procedures in general anaesthesia requiring tracheal intubation were randomized into group A with 60 min or B with 120 min preoperative clear fluid fasting. To determine gastric pH and residual volume, the gastric content was sampled in supine, left and right lateral patient position using an oro-gastric tube after intubation. Data are median (interquartile range) for group A or B (PPatient characteristic data were similar between the two groups, except for gender (46/33 males in group A/B; P=0.02). Despite significantly shorter fasting times for clear fluids in group A compared with group B (76/136 min; P<0.001), no significant difference was observed regarding gastric pH [1.43 (1.30-1.56)/1.44 (1.29-1.68), P=0.66] or residual volume [0.43 (0.21-0.84)/0.46 (0.19-0.78) ml kg(-1), P=0.47]. One hour clear fluid fasting does not alter gastric pH or residual volume significantly compared with 2 h fasting. The study was approved by the local ethics committee (KEK-ZH-Nr. 2011-0034) and registered with ClinicalTrials.gov (NCT01516775). © The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A numerical model of two-phase flow at the micro-scale using the volume-of-fluid method

Science.gov (United States)

Shams, Mosayeb; Raeini, Ali Q.; Blunt, Martin J.; Bijeljic, Branko

2018-03-01

This study presents a simple and robust numerical scheme to model two-phase flow in porous media where capillary forces dominate over viscous effects. The volume-of-fluid method is employed to capture the fluid-fluid interface whose dynamics is explicitly described based on a finite volume discretization of the Navier-Stokes equations. Interfacial forces are calculated directly on reconstructed interface elements such that the total curvature is preserved. The computed interfacial forces are explicitly added to the Navier-Stokes equations using a sharp formulation which effectively eliminates spurious currents. The stability and accuracy of the implemented scheme is validated on several two- and three-dimensional test cases, which indicate the capability of the method to model two-phase flow processes at the micro-scale. In particular we show how the co-current flow of two viscous fluids leads to greatly enhanced flow conductance for the wetting phase in corners of the pore space, compared to a case where the non-wetting phase is an inviscid gas.

An algorithm to estimate the volume of the thyroid lesions using SPECT

International Nuclear Information System (INIS)

Pina, Jorge Luiz Soares de; Mello, Rossana Corbo de; Rebelo, Ana Maria

2000-01-01

An algorithm was developed to estimate the volume of the thyroid and its functioning lesions, that is, those which capture iodine. This estimate is achieved by the use of SPECT, Single Photon Emission Computed Tomography. The algorithm was written in an extended PASCAL language subset and was accomplished to run on Siemens ICON System, a special Macintosh environment that controls the tomographic image acquisition and processing. In spite of be developed for the Siemens DIACAN gamma camera, the algorithm can be easily adapted for the ECAN camera. These two Cameras models are among the most common ones used in Nuclear Medicine in Brazil Nowadays. A phantom study was used to validate the algorithm that have shown that a threshold of 42% of maximum pixel intensity of the images it is possible to estimate the volume of the phantoms with an error of 10% in the range of 30 to 70 ml. (author)

A finite volume procedure for fluid flow, heat transfer and solid-body stress analysis

KAUST Repository

Jagad, P. I.; Puranik, B. P.; Date, A. W.

2018-01-01

A unified cell-centered unstructured mesh finite volume procedure is presented for fluid flow, heat transfer and solid-body stress analysis. An in-house procedure (A. W. Date, Solution of Transport Equations on Unstructured Meshes with Cell

Fluid Vessel Quantity using Non-Invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

Science.gov (United States)

Garofalo, Anthony A.

2013-01-01

The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

Preferential effects of low volume versus high volume replacement with crystalloid fluid in a hemorrhagic shock model in pigs.

Science.gov (United States)

Ponschab, Martin; Schöchl, Herbert; Keibl, Claudia; Fischer, Henrik; Redl, Heinz; Schlimp, Christoph J

2015-10-06

Fluid resuscitation is a core stone of hemorrhagic shock therapy, and crystalloid fluids seem to be associated with lower mortality compared to colloids. However, as redistribution starts within minutes, it has been suggested to replace blood loss with a minimum of a three-fold amount of crystalloids. The hypothesis was that in comparison to high volume (HV), a lower crystalloid volume (LV) achieves a favorable coagulation profile and exerts sufficient haemodynamics in the acute phase of resuscitation. In 24 anaesthetized pigs, controlled arterial blood loss of 50 % of the estimated blood volume was either (n = 12) replaced with a LV (one-fold) or a HV (three-fold) volume of a balanced, acetated crystalloid solution at room temperature. Hemodynamic parameters, dilution effects and coagulation profile by standard coagulation tests and thromboelastometry at baseline and after resuscitation were determined in both groups. LV resuscitation increased MAP significantly less compared to the HV, 61 ± 7 vs. 82 ± 14 mmHg (p controlled blood loss, a one fold LV crystalloid replacement strategy is sufficient to adequately raise blood pressure up to a mean arterial pressure >50 mm Hg. The concept of damage control resuscitation (DCR) with permissive hypotension may be better met by using LV as compared to a three fold HV resuscitation strategy. High volume administration of an acetated balanced crystalloid does not lead to hyperchloraemic acidosis, but may negatively influence clinical parameters, such as higher blood pressure, lower body temperature and impaired coagulation parameters, which could potentially increase bleeding after trauma. Replacement of acute blood loss with just an equal amount of an acetated balanced crystalloid appears to be the preferential treatment strategy in the acute phase after controlled bleeding.

MRI detection of hypointense brain lesions in patients with multiple sclerosis: T1 spin-echo vs. gradient-echo

Energy Technology Data Exchange (ETDEWEB)

Dupuy, Sheena L.; Tauhid, Shahamat; Kim, Gloria; Chu, Renxin; Tummala, Subhash [Departments of Neurology, Brigham and Women' s Hospital, Laboratory for Neuroimaging Research, Partners MS Center, Harvard Medical School, Boston, MA (United States); Hurwitz, Shelley [Departments of Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Bakshi, Rohit, E-mail: rbakshi@bwh.harvard.edu [Departments of Neurology, Brigham and Women' s Hospital, Laboratory for Neuroimaging Research, Partners MS Center, Harvard Medical School, Boston, MA (United States); Departments of Radiology, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

2015-08-15

Highlights: • Compared T1SE and T1GE in detecting hypointense brain lesions in MS patients. • T1GE detected a higher cerebral lesion volume and number than T1SE. • T1SE correlated significantly with disability, while T1GE did not. • Hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. - Abstract: Objective: Compare T1 spin-echo (T1SE) and T1 gradient-echo (T1GE) sequences in detecting hypointense brain lesions in multiple sclerosis (MS). Background: Chronic hypointense lesions on T1SE MRI scans are a surrogate of severe demyelination and axonal loss in MS. The role of T1GE images in the detection of such lesions has not been clarified. Design/methods: In 45 patients with MS [Expanded Disability Status Scale (EDSS) score (mean ± SD) 3.5 ± 2.0; 37 relapsing-remitting (RR); 8 secondary progressive (SP)], cerebral T1SE, T1GE, and T2-weighted fluid-attenuated inversion-recovery (FLAIR) images were acquired on a 1.5 T MRI scanner. Images were re-sampled to axial 5 mm slices before directly comparing lesion detectability using Jim (v.7, Xinapse Systems). Statistical methods included Wilcoxon signed rank tests to compare sequences and Spearman correlations to test associations. Results: Considering the entire cohort, T1GE detected a higher lesion volume (5.90 ± 6.21 vs. 4.17 ± 4.84 ml, p < 0.0001) and higher lesion number (27.82 ± 20.66 vs. 25.20 ± 20.43, p < 0.05) than T1SE. Lesion volume differences persisted when considering RR and SP patients separately (both p < 0.01). A higher lesion number by T1GE was seen only in the RR group (p < 0.05). When comparing correlations between lesion volume and overall neurologic disability (EDSS score), T1SE correlated with EDSS (Spearman r = 0.29, p < 0.05) while T1GE (r = 0.23, p = 0.13) and FLAIR (r = 0.24, p = 0.12) did not. Conclusion: Our data suggest that hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. Based on these results, we hypothesize that T1GE

MRI detection of hypointense brain lesions in patients with multiple sclerosis: T1 spin-echo vs. gradient-echo

International Nuclear Information System (INIS)

Dupuy, Sheena L.; Tauhid, Shahamat; Kim, Gloria; Chu, Renxin; Tummala, Subhash; Hurwitz, Shelley; Bakshi, Rohit

2015-01-01

Highlights: • Compared T1SE and T1GE in detecting hypointense brain lesions in MS patients. • T1GE detected a higher cerebral lesion volume and number than T1SE. • T1SE correlated significantly with disability, while T1GE did not. • Hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. - Abstract: Objective: Compare T1 spin-echo (T1SE) and T1 gradient-echo (T1GE) sequences in detecting hypointense brain lesions in multiple sclerosis (MS). Background: Chronic hypointense lesions on T1SE MRI scans are a surrogate of severe demyelination and axonal loss in MS. The role of T1GE images in the detection of such lesions has not been clarified. Design/methods: In 45 patients with MS [Expanded Disability Status Scale (EDSS) score (mean ± SD) 3.5 ± 2.0; 37 relapsing-remitting (RR); 8 secondary progressive (SP)], cerebral T1SE, T1GE, and T2-weighted fluid-attenuated inversion-recovery (FLAIR) images were acquired on a 1.5 T MRI scanner. Images were re-sampled to axial 5 mm slices before directly comparing lesion detectability using Jim (v.7, Xinapse Systems). Statistical methods included Wilcoxon signed rank tests to compare sequences and Spearman correlations to test associations. Results: Considering the entire cohort, T1GE detected a higher lesion volume (5.90 ± 6.21 vs. 4.17 ± 4.84 ml, p < 0.0001) and higher lesion number (27.82 ± 20.66 vs. 25.20 ± 20.43, p < 0.05) than T1SE. Lesion volume differences persisted when considering RR and SP patients separately (both p < 0.01). A higher lesion number by T1GE was seen only in the RR group (p < 0.05). When comparing correlations between lesion volume and overall neurologic disability (EDSS score), T1SE correlated with EDSS (Spearman r = 0.29, p < 0.05) while T1GE (r = 0.23, p = 0.13) and FLAIR (r = 0.24, p = 0.12) did not. Conclusion: Our data suggest that hypointense lesions on T1SE and T1GE are not interchangeable in patients with MS. Based on these results, we hypothesize that T1GE

Juxtacortical Lesions and Cortical Thinning in Multiple Sclerosis.

Science.gov (United States)

Pareto, D; Sastre-Garriga, J; Auger, C; Vives-Gilabert, Y; Delgado, J; Tintoré, M; Montalban, X; Rovira, A

2015-12-01

The role of juxtacortical lesions in brain volume loss in multiple sclerosis has not been fully clarified. The aim of this study was to explore the role of juxtacortical lesions on cortical atrophy and to investigate whether the presence of juxtacortical lesions is related to local cortical thinning in the early stages of MS. A total of 131 patients with clinically isolated syndrome or with relapsing-remitting MS were scanned on a 3T system. Patients with clinically isolated syndrome were classified into 3 groups based on the presence and topography of brain lesions: no lesions (n = 24), only non-juxtacortical lesions (n = 33), and juxtacortical lesions and non-juxtacortical lesions (n = 34). Patients with relapsing-remitting MS were classified into 2 groups: only non-juxtacortical lesions (n = 10) and with non-juxtacortical lesions and juxtacortical lesions (n = 30). A juxtacortical lesion probability map was generated, and cortical thickness was measured by using FreeSurfer. Juxtacortical lesion volume in relapsing-remitting MS was double that of patients with clinically isolated syndrome. The insula showed the highest density of juxtacortical lesions, followed by the temporal, parietal, frontal, and occipital lobes. Patients with relapsing-remitting MS with juxtacortical lesions showed significantly thinner cortices overall and in the parietal and temporal lobes compared with those with clinically isolated syndrome with normal brain MR imaging. The volume of subcortical structures (thalamus, pallidum, putamen, and accumbens) was significantly decreased in relapsing-remitting MS with juxtacortical lesions compared with clinically isolated syndrome with normal brain MR imaging. The spatial distribution of juxtacortical lesions was not found to overlap with areas of cortical thinning. Cortical thinning and subcortical gray matter volume loss in patients with a clinically isolated syndrome or relapsing-remitting MS was related to the presence of juxtacortical

Squeeze behavior of magnetorheological fluids under constant volume and uniform magnetic field

International Nuclear Information System (INIS)

Guo, Chaoyang; Gong, Xinglong; Xuan, Shouhu; Yan, Qifan; Ruan, Xiaohui

2013-01-01

In this work the experimental investigation of magnetorheological fluids in squeeze mode has been carried out under constant volume with a self-developed device. The magnetorheological fluids were forced to move in all directions in a horizontal plane as the two flat surfaces came together. A pair of Helmholtz coils was used to generate a uniform magnetic field in the compression gap. The normal forces within the gap were systematically studied for different magnetic field, squeeze velocity, particle concentration, viscosity of carrier fluid and initial gap distance. Two regions of behavior were obtained from the normal force versus gap distance curve: elastic deformation and plastic flow. A power law fitting was appropriate for the relation between the normal force and the gap in the plastic flow. The index of the power law was smaller than that predicted by the continuum theory, possibly due to the squeeze strengthening effect and the sealing effect. (paper)

Pro-oxidant status and matrix metalloproteinases in apical lesions and gingival crevicular fluid as potential biomarkers for asymptomatic apical periodontitis and endodontic treatment response

Directory of Open Access Journals (Sweden)

Dezerega Andrea

2012-03-01

Full Text Available Abstract Background Oxidative stress and matrix metalloproteinases -9 and -2 are involved in periodontal breakdown, whereas gingival crevicular fluid has been reported to reflect apical status. The aim of this study was to characterize oxidant balance and activity levels of MMP -2 and -9 in apical lesions and healthy periodontal ligament; and second, to determine whether potential changes in oxidant balance were reflected in gingival crevicular fluid from asymptomatic apical periodontitis (AAP-affected teeth at baseline and after endodontic treatment. Methods Patients with clinical diagnosis of AAP and healthy volunteers having indication of tooth extraction were recruited. Apical lesions and healthy periodontal ligaments, respectively, were homogenized or processed to obtain histological tissue sections. Matrix metalloproteinase -9 and -2 levels and/or activity were analyzed by Immunowestern blot, zymography and consecutive densitometric analysis, and their tissue localization was confirmed by immunohistochemistry. A second group of patients with AAP and indication of endodontic treatment was recruited. Gingival crevicular fluid was extracted from AAP-affected teeth at baseline, after endodontic treatment and healthy contralateral teeth. Total oxidant and antioxidant status were determined in homogenized tissue and GCF samples. Statistical analysis was performed using STATA v10 software with unpaired t test, Mann-Whitney test and Spearman's correlation. Results Activity of MMP-2 and MMP-9 along with oxidant status were higher in apical lesions (p Conclusions Apical lesions display an oxidant imbalance along with increased activity of matrix metalloproteinase-2 and -9 and might contribute to AAP progression. Oxidant imbalance can also be reflected in GCF from AAP-affected teeth and was restored to normal levels after conservative endodontic treatment. These mediators might be useful as potential biomarkers for chair-side complementary diagnostic

Pro-oxidant status and matrix metalloproteinases in apical lesions and gingival crevicular fluid as potential biomarkers for asymptomatic apical periodontitis and endodontic treatment response.

Science.gov (United States)

Dezerega, Andrea; Madrid, Sonia; Mundi, Verónica; Valenzuela, María A; Garrido, Mauricio; Paredes, Rodolfo; García-Sesnich, Jocelyn; Ortega, Ana V; Gamonal, Jorge; Hernández, Marcela

2012-03-21

Oxidative stress and matrix metalloproteinases -9 and -2 are involved in periodontal breakdown, whereas gingival crevicular fluid has been reported to reflect apical status. The aim of this study was to characterize oxidant balance and activity levels of MMP -2 and -9 in apical lesions and healthy periodontal ligament; and second, to determine whether potential changes in oxidant balance were reflected in gingival crevicular fluid from asymptomatic apical periodontitis (AAP)-affected teeth at baseline and after endodontic treatment. Patients with clinical diagnosis of AAP and healthy volunteers having indication of tooth extraction were recruited. Apical lesions and healthy periodontal ligaments, respectively, were homogenized or processed to obtain histological tissue sections. Matrix metalloproteinase -9 and -2 levels and/or activity were analyzed by Immunowestern blot, zymography and consecutive densitometric analysis, and their tissue localization was confirmed by immunohistochemistry. A second group of patients with AAP and indication of endodontic treatment was recruited. Gingival crevicular fluid was extracted from AAP-affected teeth at baseline, after endodontic treatment and healthy contralateral teeth. Total oxidant and antioxidant status were determined in homogenized tissue and GCF samples. Statistical analysis was performed using STATA v10 software with unpaired t test, Mann-Whitney test and Spearman's correlation. Activity of MMP-2 and MMP-9 along with oxidant status were higher in apical lesions (p Apical lesions display an oxidant imbalance along with increased activity of matrix metalloproteinase-2 and -9 and might contribute to AAP progression. Oxidant imbalance can also be reflected in GCF from AAP-affected teeth and was restored to normal levels after conservative endodontic treatment. These mediators might be useful as potential biomarkers for chair-side complementary diagnostic of apical status in GCF.

The volume of fluid injected into the tissue expander and the tissue expansion

Directory of Open Access Journals (Sweden)

Mahmood Omranifard

2014-01-01

Full Text Available Background: Replacement of the lost tissue is the major concerns of the plastic surgeons. Expanded area should be coherent with the surrounding tissue. Tissue expansion technique is the reforming methods the skin tissue scarcities. Several methods for tissue expansion are available; including usage of silicon balloon and injecting fluid into the tissue expander. Materials and Methods: In a clinical trial study, 35 patients, with burn scars, in the face, skull and neck area were studied. We provided a tissue expander device with capacities of 125, 250 and 350cc. Fluid was injected inside the device, 3 consecutive weeks with 1-week interval. After 3 months the device was set out and the tissue expansion was measured using a transparent board and the results were analyzed. Multiple regression was done by SPSS 20 to analyze the data. Results: Regression model showed Skin expansion was positively correlated with the volume of the injected fluid. For each centimeter square of skin expansion, about 6-8 ml of fluid must be injected. Conclusion: Correction of skin defects resulting from burning scar is possible using tissue expanders. The tissue expansion is correlated with the amount of the injected fluid.

Acute extracellular fluid volume changes increase ileocolonic resistance to saline flow in anesthetized dogs

Directory of Open Access Journals (Sweden)

Santiago Jr. A.T.

1997-01-01

Full Text Available We determined the effect of acute extracellular fluid volume changes on saline flow through 4 gut segments (ileocolonic, ileal, ileocolonic sphincter and proximal colon, perfused at constant pressure in anesthetized dogs. Two different experimental protocols were used: hypervolemia (iv saline infusion, 0.9% NaCl, 20 ml/min, volume up to 5% body weight and controlled hemorrhage (up to a 50% drop in mean arterial pressure. Mean ileocolonic flow (N = 6 was gradually and significantly decreased during the expansion (17.1%, P<0.05 and expanded (44.9%, P<0.05 periods while mean ileal flow (N = 7 was significantly decreased only during the expanded period (38%, P<0.05. Mean colonic flow (N = 7 was decreased during expansion (12%, P<0.05 but returned to control levels during the expanded period. Mean ileocolonic sphincter flow (N = 6 was not significantly modified. Mean ileocolonic flow (N = 10 was also decreased after hemorrhage (retracted period by 17% (P<0.05, but saline flow was not modified in the other separate circuits (N = 6, 5 and 4 for ileal, ileocolonic sphincter and colonic groups, respectively. The expansion effect was blocked by atropine (0.5 mg/kg, iv both on the ileocolonic (N = 6 and ileal (N = 5 circuits. Acute extracellular fluid volume retraction and expansion increased the lower gastrointestinal resistances to saline flow. These effects, which could physiologically decrease the liquid volume being supplied to the colon, are possible mechanisms activated to acutely balance liquid volume deficit and excess.

EFFECT OF THE VOLUME OF FLUID INGESTED ON URINE CONCENTRATING ABILITY DURING PROLONGED HEAVY EXERCISE IN A HOT ENVIRONMENT

Directory of Open Access Journals (Sweden)

Hidenori Otani

2013-03-01

Full Text Available This study examined the effect of the volume of fluid ingested on urine concentrating ability during prolonged heavy exercise in a hot environment at low levels of dehydration. Seven healthy males performed 105 min of intermittent cycle exercise at 70% maximum oxygen uptake (32°C, 60% relative humidity while receiving no fluid ingestion (NF, voluntary fluid ingestion (VF, partial fluid ingestion equivalent to one-half of body mass loss (PF, and full fluid ingestion equivalent to body mass loss (FF. Fluid (5°C, 3.4% carbohydrate, 10.5 mmol·L-1 sodium was ingested just before commencing exercise and at 15, 33, 51, 69, and 87 min of exercise, and the total amount of fluid ingested in PF and FF was divided into six equal volumes. During exercise, body mass loss was 2.2 ± 0.2, 1.1 ± 0.5, 1.1 ± 0.2, and 0.1 ± 0.2% in NF, VF, PF, and FF, respectively, whereas total sweat loss was about 2% of body mass in each trial. Subjects in VF ingested 719 ± 240 ml of fluid during exercise; the volume of fluid ingested was 1.1 ± 0.4% of body mass. Creatinine clearance was significantly higher and free water clearance was significantly lower in FF than in NF during exercise. Urine flow rate during exercise decreased significantly in NF. There were significant decreases in creatinine and osmolar clearance and was a significant increase in free water clearance during exercise in NF and VF. Creatinine clearance decreased significantly and free water clearance increased significantly during exercise in PF. There was no statistical change in urinary indices of renal function during exercise in FF. The findings suggest that full fluid ingestion equivalent to body mass loss has attenuated the decline in urine concentrating ability during prolonged heavy exercise in a hot environment at low levels of dehydration.

Technology for Space Station Evolution. Volume 3: EVA/Manned Systems/Fluid Management System

Science.gov (United States)

1990-01-01

NASA's Office of Aeronautics and Space Technology (OAST) conducted a workshop on technology for space station evolution 16-19 Jan. 1990 in Dallas, Texas. The purpose of this workshop was to collect and clarify Space Station Freedom technology requirements for evolution and to describe technologies that can potentially fill those requirements. These proceedings are organized into an Executive Summary and Overview and five volumes containing the Technology Discipline Presentations. Volume 3 consists of the technology discipline sections for Extravehicular Activity/Manned Systems and the Fluid Management System. For each technology discipline, there is a Level 3 subsystem description, along with the papers.

Stroke infarct volume estimation in fixed tissue

DEFF Research Database (Denmark)

Bay, Vibeke; Kjølby, Birgitte F; Iversen, Nina K

2018-01-01

be investigated in fixed tissue and therefore allows a more direct comparison between lesion volumes from MRI and histology. Additionally, the larger MKT infarct lesion indicates that MKT do provide increased sensitivity to microstructural changes in the lesion area compared to MD....... and prepared. The infarct was clearly visible in both MD and MKT maps. The MKT lesion volume was roughly 31% larger than the MD lesion volume. Subsequent histological analysis (hematoxylin) revealed similar lesion volumes to MD. Our study shows that structural components underlying the MD/MKT mismatch can...

Classification of multiple sclerosis lesions using adaptive dictionary learning.

Science.gov (United States)

Deshpande, Hrishikesh; Maurel, Pierre; Barillot, Christian

2015-12-01

This paper presents a sparse representation and an adaptive dictionary learning based method for automated classification of multiple sclerosis (MS) lesions in magnetic resonance (MR) images. Manual delineation of MS lesions is a time-consuming task, requiring neuroradiology experts to analyze huge volume of MR data. This, in addition to the high intra- and inter-observer variability necessitates the requirement of automated MS lesion classification methods. Among many image representation models and classification methods that can be used for such purpose, we investigate the use of sparse modeling. In the recent years, sparse representation has evolved as a tool in modeling data using a few basis elements of an over-complete dictionary and has found applications in many image processing tasks including classification. We propose a supervised classification approach by learning dictionaries specific to the lesions and individual healthy brain tissues, which include white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF). The size of the dictionaries learned for each class plays a major role in data representation but it is an even more crucial element in the case of competitive classification. Our approach adapts the size of the dictionary for each class, depending on the complexity of the underlying data. The algorithm is validated using 52 multi-sequence MR images acquired from 13 MS patients. The results demonstrate the effectiveness of our approach in MS lesion classification. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fluid mechanics experiments in oscillatory flow. Volume 1: Report

Science.gov (United States)

Seume, J.; Friedman, G.; Simon, T. W.

1992-01-01

Results of a fluid mechanics measurement program in oscillating flow within a circular duct are presented. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re(sub max), Re(sub w), and A(sub R), embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA's Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radial components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and its reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. Volume 1 contains the text of the report including figures and supporting appendices. Volume 2 contains data reduction program listings and tabulated data (including its graphical presentation).

[Effect of different volumes of fluid resuscitation on hemorrhagic shock with pulmonary edema at high altitude in the unacclimated rat].

Science.gov (United States)

Liu, Liang-ming; Hu, De-yao; Liu, Jian-cang; Li, Ping; Liu, Hou-dong; Xiao, Nan; Zhou, Xue-wu; Tian, Kun-lun; Huo, Xiao-ping; Shi, Quan-gui; He, Yan-mei; Yin, Zuo-ming

2003-05-01

To study the effects of different volumes of fluid resuscitation on hemorrhagic shock with pulmonary edema at high altitude in the unacclimated rat. One hundred and twenty-six SD rats transported to Lasa, Tibet, 3 760 meters above the sea level, were anesthetized one week later with sodium pentobarbital (30 mg/kg, intraperitoneal). Hemorrhagic shock with pulmonary edema model was induced by hemorrhage (50 mm Hg for 1 hour, 1 mmHg=0.133 kPa) plus intravenous injection of oleic acid (50 microl/kg). Experiments were then conducted in two parts. Sixty-three rats in part I were equally divided into nine groups (n=7): normal control, hemorrhagic shock control, hemorrhagic shock with pulmonary edema (HSPE) without fluid infusion, HSPE plus infusing lactated Ringer's solution (LR) with 0.5-, 1-, 1.5-, 2- or 3- fold volume shed blood, and 1 volume of LR plus mannitol (10 ml/kg). Hemodynamic parameters including mean arterial blood pressure (MAP), left intraventricular systolic pressure (LVSP) and the maximal change rate of intraventricular pressure rise or decline (+/- dp/dt max) were observed at 15, 30, 60 and 120 minutes after infusion, blood gases were measured at 30 and 120 minutes after infusion and the water content of lung and brain was determined at 120 minutes after infusion. In part II, additional 63 rats were used to observe the effect of different volumes of fluid resuscitation on survival time of HSPE rats. 0.5 volume of LR infusion significantly improved MAP, LVSP and +/- dp/dt max, prolonged the survival time of HSPE animals (all P<0.01), while it did not increase the water content of lung and brain and had no marked influence on blood gases. One volume of LR infusion slightly improved hemodynamic parameters, prolonged the survival time and increased the water content of lung. More than 1 volume of LR infusion including 1.5-, 2- and 3- fold volume LR deteriorated the hemodynamic parameters and decreased the survival time of shocked animal, meanwhile they

Acoustic radiation force impulse (ARFI) ultrasound imaging of pancreatic cystic lesions

Energy Technology Data Exchange (ETDEWEB)

D' Onofrio, M., E-mail: mirko.donofrio@univr.it [Department of Radiology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Gallotti, A. [Department of Radiology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Salvia, R. [Department of Surgery, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Capelli, P. [Department of Pathology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Mucelli, R. Pozzi [Department of Radiology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy)

2011-11-15

Purpose: To evaluate the ARFI ultrasound imaging with Virtual Touch tissue quantification in studying pancreatic cystic lesions, compared with phantom fluid models. Materials and methods: Different phantom fluids at different viscosity or density (water, iodinate contrast agent, and oil) were evaluated by two independent operators. From September to December 2008, 23 pancreatic cystic lesions were prospectively studied. All lesions were pathologically confirmed. Results: Non-numerical values on water and numerical values on other phantoms were obtained. Inter-observer evaluation revealed a perfect correlation (rs = 1.00; p < 0.0001) between all measurements achieved by both operators per each balloon and fluid. Among the pancreatic cystic lesions, 14 mucinous cystadenomas, 4 pseudocysts, 3 intraductal papillary-mucinous neoplasms and 2 serous cystadenomas were studied. The values obtained ranged from XXXX/0-4,85 m/s in mucinous cystadenomas, from XXXX/0-3,11 m/s in pseudocysts, from XXXX/0-4,57 m/s in intraductal papillary-mucinous neoplasms. In serous cystadenomas all values measured were XXXX/0 m/s. Diagnostic accuracy in benign and non-benign differentiation of pancreatic cystic lesions was 78%. Conclusions: Virtual Touch tissue quantification can be applied in the analysis of fluids and is potentially able to differentiate more complex (mucinous) from simple (serous) content in studying pancreatic cystic lesions.

Acoustic radiation force impulse (ARFI) ultrasound imaging of pancreatic cystic lesions

International Nuclear Information System (INIS)

D'Onofrio, M.; Gallotti, A.; Salvia, R.; Capelli, P.; Mucelli, R. Pozzi

2011-01-01

Purpose: To evaluate the ARFI ultrasound imaging with Virtual Touch tissue quantification in studying pancreatic cystic lesions, compared with phantom fluid models. Materials and methods: Different phantom fluids at different viscosity or density (water, iodinate contrast agent, and oil) were evaluated by two independent operators. From September to December 2008, 23 pancreatic cystic lesions were prospectively studied. All lesions were pathologically confirmed. Results: Non-numerical values on water and numerical values on other phantoms were obtained. Inter-observer evaluation revealed a perfect correlation (rs = 1.00; p < 0.0001) between all measurements achieved by both operators per each balloon and fluid. Among the pancreatic cystic lesions, 14 mucinous cystadenomas, 4 pseudocysts, 3 intraductal papillary-mucinous neoplasms and 2 serous cystadenomas were studied. The values obtained ranged from XXXX/0-4,85 m/s in mucinous cystadenomas, from XXXX/0-3,11 m/s in pseudocysts, from XXXX/0-4,57 m/s in intraductal papillary-mucinous neoplasms. In serous cystadenomas all values measured were XXXX/0 m/s. Diagnostic accuracy in benign and non-benign differentiation of pancreatic cystic lesions was 78%. Conclusions: Virtual Touch tissue quantification can be applied in the analysis of fluids and is potentially able to differentiate more complex (mucinous) from simple (serous) content in studying pancreatic cystic lesions.

Fluid Statics and Archimedes

Indian Academy of Sciences (India)

librium of a vertical slice fluid (Figure Id) of height H and again using the fact .... same fluid having the same shape and same volume as the body. This fluid volume .... example, can be caused by the heating of air near the ground by the sun ...

Can a Morel-Lavallée lesion be misdiagnosed as a mass like lesion?

Science.gov (United States)

Lee, Yoon Jae; Kim, Jun Hyeok; Kim, Ji Young; Han, Hyun Ho

2017-12-01

The Morel-Lavallée lesion (MLL) is a post-traumatic closed soft tissue degloving injury. Common complaints of MLL patients are a haematoma or fluid collection on the trunk or the lower extremity. However, the authors introduce unique cases of MLL that present an atypical appearance. The fluid collection was not apparent, and the capsule formation was not detected on preoperative image study. The main complaint of patients was the uncomfortable mass-like lesion that was regarded as a simple benign lump. The purpose of this case study is to introduce the atypical cases of MLL and to help other physicians make accurate diagnosis based on trial and error of our cases. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Effect of pre-donation fluid intake on fluid shift from interstitial to intravascular compartment in blood donors.

Science.gov (United States)

Deepika, Chenna; Murugesan, Mohandoss; Shastry, Shamee

2018-02-01

Fluid shifts from interstitial to intravascular space during blood donation helps in compensating the lost blood volume. We aimed to determine the volume of fluid shift following donation in donors with and without pre-donation fluid intake. We studied the fluid shift in 325 blood donors prospectively. Donors were divided in groups- with no fluid intake (GI) and either water (GII) or oral rehydrating fluids (GIII) before donation. Fluid shift following donation was calculated based on the difference between the pre and post donation blood volume. The influence of oral fluid intake, age, gender and body mass index (BMI) on volume of fluid shift was analyzed. The fluid shift was significant between donors without fluids (GI: 127 ± 81 ml) and donors with fluid intake (GII & III: 96 ± 45 ml) (p donation. As per our observation, the oral fluids before donation might not contribute to increase in fluid shift in blood donors after donation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stroke volume variation compared with pulse pressure variation and cardiac index changes for prediction of fluid responsiveness in mechanically ventilated patients

Directory of Open Access Journals (Sweden)

Randa Aly Soliman

2015-04-01

Conclusions: Baseline stroke volume variation ⩾8.15% predicted fluid responsiveness in mechanically ventilated patients with acute circulatory failure. The study also confirmed the ability of pulse pressure variation to predict fluid responsiveness.

Interobserver agreement for sonograms of breast lesions obtained by an automated breast volume scanner

International Nuclear Information System (INIS)

Zhang, Jing; Lai, Xing-Jian; Zhu, Qing-Li; Wang, Hong-Yan; Jiang, Yu-Xin; Liu, He; Dai, Qing; You, Shan-Shan; Xiao, Meng-Su

2012-01-01

Objective: To evaluate the interobserver agreement of radiologists in the description and final assessment of breast sonograms obtained using an automated breast volume scanner (ABVS) using a unique descriptor of three-dimensional ultrasound (3D US) and the Breast Imaging Reporting and Data System (BI-RADS) US lexicon. Methods: From October to December 2010, 208 patients were subjected to an ABVS examination in the supine position, and data were automatically sent to the ABVS workstation. Two radiologists independently evaluated 234 breast masses (148 benign and 86 malignant masses) using a unique descriptor from the 3D US and the BI-RADS US lexicon. The reviewers were blinded to the patient's mammographic images, medical history, and pathologic findings. The interobserver agreement was measured using kappa statistics. Results: Substantial agreement was obtained for lesion shape, orientation, margin, echo pattern, posterior acoustic features, calcification and final assessment (κ = 0.79, 0.74, 0.76, 0.69, 0.68, 0.71 and 0.70, respectively). Fair agreement was obtained for retraction phenomenon and lesion boundary (κ = 0.54 and 0.42, respectively). Conclusions: The interobserver agreement for breast sonograms obtained by ABVS is good, especially for lesion shape and margin; however, the interobserver agreement for the retraction phenomenon, which is a unique descriptor of coronal-plane 3D US, needs to be improved

Molecular representation of molar domain (volume), evolution equations, and linear constitutive relations for volume transport.

Science.gov (United States)

Eu, Byung Chan

2008-09-07

In the traditional theories of irreversible thermodynamics and fluid mechanics, the specific volume and molar volume have been interchangeably used for pure fluids, but in this work we show that they should be distinguished from each other and given distinctive statistical mechanical representations. In this paper, we present a general formula for the statistical mechanical representation of molecular domain (volume or space) by using the Voronoi volume and its mean value that may be regarded as molar domain (volume) and also the statistical mechanical representation of volume flux. By using their statistical mechanical formulas, the evolution equations of volume transport are derived from the generalized Boltzmann equation of fluids. Approximate solutions of the evolution equations of volume transport provides kinetic theory formulas for the molecular domain, the constitutive equations for molar domain (volume) and volume flux, and the dissipation of energy associated with volume transport. Together with the constitutive equation for the mean velocity of the fluid obtained in a previous paper, the evolution equations for volume transport not only shed a fresh light on, and insight into, irreversible phenomena in fluids but also can be applied to study fluid flow problems in a manner hitherto unavailable in fluid dynamics and irreversible thermodynamics. Their roles in the generalized hydrodynamics will be considered in the sequel.

Simulation of biological flow and transport in complex geometries using embedded boundary/volume-of-fluid methods

International Nuclear Information System (INIS)

Trebotich, David

2007-01-01

We have developed a simulation capability to model multiscale flow and transport in complex biological systems based on algorithms and software infrastructure developed under the SciDAC APDEC CET. The foundation of this work is a new hybrid fluid-particle method for modeling polymer fluids in irregular microscale geometries that enables long-time simulation of validation experiments. Both continuum viscoelastic and discrete particle representations have been used to model the constitutive behavior of polymer fluids. Complex flow environment geometries are represented on Cartesian grids using an implicit function. Direct simulation of flow in the irregular geometry is then possible using embedded boundary/volume-of-fluid methods without loss of geometric detail. This capability has been used to simulate biological flows in a variety of application geometries including biomedical microdevices, anatomical structures and porous media

Evaluation of stroke volume variation obtained by arterial pulse contour analysis to predict fluid responsiveness intraoperatively.

Science.gov (United States)

Lahner, D; Kabon, B; Marschalek, C; Chiari, A; Pestel, G; Kaider, A; Fleischmann, E; Hetz, H

2009-09-01

Fluid management guided by oesophageal Doppler monitor has been reported to improve perioperative outcome. Stroke volume variation (SVV) is considered a reliable clinical predictor of fluid responsiveness. Consequently, the aim of the present trial was to evaluate the accuracy of SVV determined by arterial pulse contour (APCO) analysis, using the FloTrac/Vigileo system, to predict fluid responsiveness as measured by the oesophageal Doppler. Patients undergoing major abdominal surgery received intraoperative fluid management guided by oesophageal Doppler monitoring. Fluid boluses of 250 ml each were administered in case of a decrease in corrected flow time (FTc) to 10%. The ability of SVV to predict fluid responsiveness was assessed by calculation of the area under the receiver operating characteristic (ROC) curve. Twenty patients received 67 fluid boluses. Fifty-two of the 67 fluid boluses administered resulted in fluid responsiveness. SVV achieved an area under the ROC curve of 0.512 [confidence interval (CI) 0.32-0.70]. A cut-off point for fluid responsiveness was found for SVV > or =8.5% (sensitivity: 77%; specificity: 43%; positive predictive value: 84%; and negative predictive value: 33%). This prospective, interventional observer-blinded study demonstrates that SVV obtained by APCO, using the FloTrac/Vigileo system, is not a reliable predictor of fluid responsiveness in the setting of major abdominal surgery.

Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma.

Science.gov (United States)

Göttler, Jens; Lukas, Mathias; Kluge, Anne; Kaczmarz, Stephan; Gempt, Jens; Ringel, Florian; Mustafa, Mona; Meyer, Bernhard; Zimmer, Claus; Schwaiger, Markus; Förster, Stefan; Preibisch, Christine; Pyka, Thomas

2017-03-01

18 F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology.

Quantitative estimation of a ratio of intracranial cerebrospinal fluid volume to brain volume based on segmentation of CT images in patients with extra-axial hematoma.

Science.gov (United States)

Nguyen, Ha Son; Patel, Mohit; Li, Luyuan; Kurpad, Shekar; Mueller, Wade

2017-02-01

Background Diminishing volume of intracranial cerebrospinal fluid (CSF) in patients with space-occupying masses have been attributed to unfavorable outcome associated with reduction of cerebral perfusion pressure and subsequent brain ischemia. Objective The objective of this article is to employ a ratio of CSF volume to brain volume for longitudinal assessment of space-volume relationships in patients with extra-axial hematoma and to determine variability of the ratio among patients with different types and stages of hematoma. Patients and methods In our retrospective study, we reviewed 113 patients with surgical extra-axial hematomas. We included 28 patients (age 61.7 +/- 17.7 years; 19 males, nine females) with an acute epidural hematoma (EDH) ( n = 5) and subacute/chronic subdural hematoma (SDH) ( n = 23). We excluded 85 patients, in order, due to acute SDH ( n = 76), concurrent intraparenchymal pathology ( n = 6), and bilateral pathology ( n = 3). Noncontrast CT images of the head were obtained using a CT scanner (2004 GE LightSpeed VCT CT system, tube voltage 140 kVp, tube current 310 mA, 5 mm section thickness) preoperatively, postoperatively (3.8 ± 5.8 hours from surgery), and at follow-up clinic visit (48.2 ± 27.7 days after surgery). Each CT scan was loaded into an OsiriX (Pixmeo, Switzerland) workstation to segment pixels based on radiodensity properties measured in Hounsfield units (HU). Based on HU values from -30 to 100, brain, CSF spaces, vascular structures, hematoma, and/or postsurgical fluid were segregated from bony structures, and subsequently hematoma and/or postsurgical fluid were manually selected and removed from the images. The remaining images represented overall brain volume-containing only CSF spaces, vascular structures, and brain parenchyma. Thereafter, the ratio between the total number of voxels representing CSF volume (based on values between 0 and 15 HU) to the total number of voxels

State of the art in fluid and volume therapy : A user-friendly staged concept. English version.

Science.gov (United States)

Rehm, M; Hulde, N; Kammerer, T; Meidert, A S; Hofmann-Kiefer, K

2017-04-10

Adequate intraoperative infusion therapy is essential for the perioperative outcome of a patient. Both hypo- and hypervolemia can lead to an increased rate of perioperative complications and to a worse outcome. Perioperative infusion therapy should therefore be needs-based. The primary objective is the maintenance of preoperative normovolemia using a rational infusion strategy. Perioperative fluid losses should be differentiated from volume losses due to surgical bleeding or protein losses into the interstitial space. Fluid loss via urine excretion or insensible perspiration (0.5-1.0 ml/kg/h) should be replaced with balanced, isooncotic, crystalloid infusion solutions in a ratio of 1:1. Volume therapy stage 1: intraoperative volume losses up to a blood loss corresponding to 20% of the patient's total blood volume are compensated for by balanced crystalloids in a ratio of 4-5:1. Stage 2: blood losses exceeding this level are to be treated with isooncotic colloids (preferably balanced) in a 1:1 ratio. In this regard taking into consideration the contraindications, e. g., sepsis, burns, critical illness (usually patients in the intensive care unit), impaired renal function or renal replacement therapy, intracranial hemorrhage, or severe coagulopathy, artificial colloids such as hydroxyethyl starch (HES) can be used perioperatively for volume replacement. Stage 3: if an allogeneic blood transfusion is indicated, blood and blood products are applied in a differentiated manner.

Effect of fluid loading on left ventricular volume and stroke volume variability in patients with end-stage renal disease: a pilot study

Science.gov (United States)

Kanda, Hirotsugu; Hirasaki, Yuji; Iida, Takafumi; Kanao-Kanda, Megumi; Toyama, Yuki; Kunisawa, Takayuki; Iwasaki, Hiroshi

2015-01-01

Purpose The aim of this study was to investigate fluid loading-induced changes in left ventricular end-diastolic volume (LVEDV) and stroke volume variability (SVV) in patients with end-stage renal disease (ESRD) using real-time three-dimensional transesophageal echocardiography and the Vigileo-FloTrac system. Patients and methods After obtaining ethics committee approval and informed consent, 28 patients undergoing peripheral vascular procedures were studied. Fourteen patients with ESRD on hemodialysis (HD) were assigned to the HD group and 14 patients without ESRD were assigned to the control group. Institutional standardized general anesthesia was provided in both groups. SVV was measured using the Vigileo-FloTrac system. Simultaneously, a full-volume three-dimensional transesophageal echocardiography dataset was acquired to measure LVEDV, left ventricular end-systolic volume, and left ventricular ejection fraction. Measurements were obtained before and after loading 500 mL hydroxyethyl starch over 30 minutes in both groups. Results In the control group, intravenous colloid infusion was associated with a significant decrease in SVV (13.8%±2.6% to 6.5%±2.6%, P<0.001) and a significant increase in LVEDV (83.6±23.4 mL to 96.1±28.8 mL, P<0.001). While SVV significantly decreased after infusion in the HD group (16.2%±6.0% to 6.2%±2.8%, P<0.001), there was no significant change in LVEDV. Conclusion Our preliminary data suggest that fluid responsiveness can be assessed not by LVEDV but also by SVV due to underlying cardiovascular pathophysiology in patients with ESRD. PMID:26527879

Spaceflight-Induced Visual Impairment and Globe Deformations in Astronauts Are Linked to Orbital Cerebrospinal Fluid Volume Increase.

Science.gov (United States)

Alperin, Noam; Bagci, Ahmet M

2018-01-01

Most of the astronauts onboard the International Space Station (ISS) develop visual impairment and ocular structural changes that are not fully reversible upon return to earth. Current understanding assumes that the so-called visual impairments/intracranial pressure (VIIP) syndrome is caused by cephalad vascular fluid shift. This study assesses the roles of cerebrospinal fluid (CSF) and intracranial pressure (ICP) in VIIP. Seventeen astronauts, 9 who flew a short-duration mission on the space shuttle (14.1 days [SD 1.6]) and 7 who flew a long-duration mission on the ISS (188 days [SD 22]) underwent MRI of the brain and orbits to assess the pre-to-post spaceflight changes in four categories: VIIP severity measures: globe flattening and nerve protrusion; orbital and ventricular CSF volumes; cortical gray and white matter volumes; and MR-derived ICP (MRICP). Significant pre-to-post-flight increase in globe flattening and optic nerve protrusion occurred only in the long-duration cohort (0.031 [SD 0.019] vs -0.001 [SD 0.006], and 0.025 [SD 0.013] vs 0.001 [SD 0.006]; p < 0.00002 respectively). The increased globe deformations were associated with significant increases in orbital and ventricular CSF volumes, but not with increased tissue vascular fluid content. Additionally, a moderate increase in MRICP of 6 mmHg was observed in only two ISS astronauts with large ocular structure changes. These findings are evidence for the primary role of CSF and a lesser role for intracranial cephalad fluid-shift in the formation of VIIP. VIIP is caused by a prolonged increase in orbital CSF spaces that compress the globes' posterior pole, even without a large increase in ICP.

Stroke Lesions in a Large Upper Limb Rehabilitation Trial Cohort Rarely Match Lesions in Common Preclinical Models

Science.gov (United States)

Edwardson, Matthew A.; Wang, Ximing; Liu, Brent; Ding, Li; Lane, Christianne J.; Park, Caron; Nelsen, Monica A.; Jones, Theresa A; Wolf, Steven L; Winstein, Carolee J; Dromerick, Alexander W.

2017-01-01

Background Stroke patients with mild-moderate upper extremity (UE) motor impairments and minimal sensory and cognitive deficits provide a useful model to study recovery and improve rehabilitation. Laboratory-based investigators use lesioning techniques for similar goals. Objective Determine whether stroke lesions in an UE rehabilitation trial cohort match lesions from the preclinical stroke recovery models used to drive translational research. Methods Clinical neuroimages from 297 participants enrolled in the Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) study were reviewed. Images were characterized based on lesion type (ischemic or hemorrhagic), volume, vascular territory, depth (cortical gray matter, cortical white matter, subcortical), old strokes, and leukoaraiosis. Lesions were compared with those of preclinical stroke models commonly used to study upper limb recovery. Results Among the ischemic stroke participants, median infarct volume was 1.8 mL, with most lesions confined to subcortical structures (61%) including the anterior choroidal artery territory (30%) and the pons (23%). Of ICARE participants, stroke patients, but they represent a clinically and scientifically important subgroup. Compared to lesions in general stroke populations and widely-studied animal models of recovery, ICARE participants had smaller, more subcortically-based strokes. Improved preclinical-clinical translational efforts may require better alignment of lesions between preclinical and human stroke recovery models. PMID:28337932

Conservative and bounded volume-of-fluid advection on unstructured grids

Science.gov (United States)

Ivey, Christopher B.; Moin, Parviz

2017-12-01

This paper presents a novel Eulerian-Lagrangian piecewise-linear interface calculation (PLIC) volume-of-fluid (VOF) advection method, which is three-dimensional, unsplit, and discretely conservative and bounded. The approach is developed with reference to a collocated node-based finite-volume two-phase flow solver that utilizes the median-dual mesh constructed from non-convex polyhedra. The proposed advection algorithm satisfies conservation and boundedness of the liquid volume fraction irrespective of the underlying flux polyhedron geometry, which differs from contemporary unsplit VOF schemes that prescribe topologically complicated flux polyhedron geometries in efforts to satisfy conservation. Instead of prescribing complicated flux-polyhedron geometries, which are prone to topological failures, our VOF advection scheme, the non-intersecting flux polyhedron advection (NIFPA) method, builds the flux polyhedron iteratively such that its intersection with neighboring flux polyhedra, and any other unavailable volume, is empty and its total volume matches the calculated flux volume. During each iteration, a candidate nominal flux polyhedron is extruded using an iteration dependent scalar. The candidate is subsequently intersected with the volume guaranteed available to it at the time of the flux calculation to generate the candidate flux polyhedron. The difference in the volume of the candidate flux polyhedron and the actual flux volume is used to calculate extrusion during the next iteration. The choice in nominal flux polyhedron impacts the cost and accuracy of the scheme; however, it does not impact the methods underlying conservation and boundedness. As such, various robust nominal flux polyhedron are proposed and tested using canonical periodic kinematic test cases: Zalesak's disk and two- and three-dimensional deformation. The tests are conducted on the median duals of a quadrilateral and triangular primal mesh, in two-dimensions, and on the median duals of a

Fluid mechanics experiments in oscillatory flow. Volume 2: Tabulated data

Science.gov (United States)

Seume, J.; Friedman, G.; Simon, T. W.

1992-01-01

Results of a fluid mechanics measurement program in oscillating flow within a circular duct are presented. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re sub max, Re sub w, and A sub R, embody the velocity amplitude, frequency of oscillation, and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters that are representative of the heat exchanger tubes in the heater section of NASA's Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radial components of ensemble-averaged velocity and rms velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and its reverse, were identified and sufficient data was gathered to propose the transition mechanism. Volume 2 contains data reduction program listings and tabulated data (including its graphics).

The coupled effect of fiber volume fraction and void fraction on hydraulic fluid absorption of quartz/BMI laminates

Science.gov (United States)

Hurdelbrink, Keith R.; Anderson, Jacob P.; Siddique, Zahed; Altan, M. Cengiz

2016-03-01

Bismaleimide (BMI) resin with quartz (AQ581) fiber reinforcement is a composite material frequently used in aerospace applications, such as engine cowlings and radomes. Various composite components used in aircrafts are exposed to different types of hydraulic fluids, which may lead to anomalous absorption behavior over the service life of the composite. Accurate predictive models for absorption of liquid penetrants are particularly important as the composite components are often exposed to long-term degradation due to absorbed moisture, hydraulic fluids, or similar liquid penetrants. Microstructural features such as fiber volume fraction and void fraction can have a significant effect on the absorption behavior of fiber-reinforced composites. In this paper, hydraulic fluid absorption characteristics of quartz/BMI laminates fabricated from prepregs preconditioned at different relative humidity and subsequently cured at different pressures are presented. The composite samples are immersed into hydraulic fluid at room temperature, and were not subjected to any prior degradation. To generate process-induced microvoids, prepregs were conditioned in an environmental chamber at 2% or 99% relative humidity at room temperature for a period of 24 hours prior to laminate fabrication. To alter the fiber volume fraction, the laminates were fabricated at cure pressures of 68.9 kPa (10 psi) or 482.6 kPa (70 psi) via a hot-press. The laminates are shown to have different levels of microvoids and fiber volume fractions, which were observed to affect the absorption dynamics considerably and exhibited clear non-Fickian behavior. A one-dimensional hindered diffusion model (HDM) was shown to be successful in predicting the hydraulic fluid absorption. Model prediction indicates that as the fabrication pressure increased from 68.9 kPa to 482.6 kPa, the maximum fluid content (M∞) decreased from 8.0% wt. to 1.0% wt. The degree of non-Fickian behavior, measured by hindrance coefficient (�

Fluid dynamics theoretical and computational approaches

CERN Document Server

Warsi, ZUA

2005-01-01

Important Nomenclature Kinematics of Fluid Motion Introduction to Continuum Motion Fluid Particles Inertial Coordinate Frames Motion of a Continuum The Time Derivatives Velocity and Acceleration Steady and Nonsteady Flow Trajectories of Fluid Particles and Streamlines Material Volume and Surface Relation between Elemental Volumes Kinematic Formulas of Euler and Reynolds Control Volume and Surface Kinematics of Deformation Kinematics of Vorticity and Circulation References Problems The Conservation Laws and the Kinetics of Flow Fluid Density and the Conservation of Mass Prin

Fluid mechanics in fluids at rest.

Science.gov (United States)

Brenner, Howard

2012-07-01

Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

Rapid increase in cystic volume of an anaplastic astrocytoma misdiagnosed as neurocysticercosis: A case report

Science.gov (United States)

Li, Hong-Jiang; Han, Hong-Xiu; Feng, Dong-Fu

2016-01-01

Reports describing a rapid increase in the cystic volume of anaplastic astrocytoma (AA) in a short time frame are rare. The present study reports the case of a 68-year-old male who was admitted to the No. 9 People's Hospital, Shanghai Jiaotong University School of Medicine (Shanghai, China), with a small cystic brain lesion and positive immunological testing for cysticercosis. Head magnetic resonance imaging (MRI) showed a cystic lesion, 6 mm in diameter, in the left frontal lobe. Neurocysticercosis was suspected and the patient was treated with a clinical trial of albendazole and steroids. A period of 25 days later, the patient's condition had deteriorated, and MRI revealed a cystic lesion in the left frontal lobe; thereafter, the cystic lesion was removed and a diagnosis of AA was established. The tumor was soft, ivory white and gelatinous due to myxoid degeneration. In this case, tumor-related angiogenesis and microvascular extravasation (blood-brain barrier disruption) may have been the main cause of the rapid increase in the cystic volume in such a short time frame. The similarity of the glioma and cysticercus antigens may have been the cause of the positive reactions in the cystic fluid. The present study reports the rare occurrence of a rapid increase of cystic volume and potential diagnostic difficulties. PMID:27698865

Morel-Lavallee lesion in the knee: a case report

Energy Technology Data Exchange (ETDEWEB)

Pitrez, Eduardo Hennemann, E-mail: epitrez@terra.com.b [Clinica Radiologica Osorio Lopes, Porto Alegre, RS (Brazil); Pellanda, Roberto Campos; Silva, Mariana Eltz; Holz, Gustavo Garcia; Hertz, Felipe Teixeira [Pontificia Univ. Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil). Hospital Sao Lucas; Hoefel Filho, Joao Rubiao [Pontificia Univ. Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil). Center of Imaging Diagnosis

2010-09-15

Morel-Lavallee lesion is a degloving injury of the interface between the subcutaneous fat and the underlying fascia. This lesion is characterized by the development of a fluid collection that, although originally described in the thigh, it has also been described in other anatomical sites. The authors report the case of a patient with Morel-Lavallee lesion in the knee after trauma and describe the main characteristics of the lesion. (author)

Morel-Lavallee lesion in the knee: a case report

International Nuclear Information System (INIS)

Pitrez, Eduardo Hennemann; Pellanda, Roberto Campos; Silva, Mariana Eltz; Holz, Gustavo Garcia; Hertz, Felipe Teixeira; Hoefel Filho, Joao Rubiao

2010-01-01

Morel-Lavallee lesion is a degloving injury of the interface between the subcutaneous fat and the underlying fascia. This lesion is characterized by the development of a fluid collection that, although originally described in the thigh, it has also been described in other anatomical sites. The authors report the case of a patient with Morel-Lavallee lesion in the knee after trauma and describe the main characteristics of the lesion. (author)

Ivy Sign on Fluid-Attenuated Inversion Recovery Images in Moyamoya Disease: Correlation with Clinical Severity and Old Brain Lesions.

Science.gov (United States)

Seo, Kwon-Duk; Suh, Sang Hyun; Kim, Yong Bae; Kim, Ji Hwa; Ahn, Sung Jun; Kim, Dong-Seok; Lee, Kyung-Yul

2015-09-01

Leptomeningeal collateral, in moyamoya disease (MMD), appears as an ivy sign on fluid-attenuated inversion-recovery (FLAIR) images. There has been little investigation into the relationship between presentation of ivy signs and old brain lesions. We aimed to evaluate clinical significance of ivy signs and whether they correlate with old brain lesions and the severity of clinical symptoms in patients with MMD. FLAIR images of 83 patients were reviewed. Each cerebral hemisphere was divided into 4 regions and each region was scored based on the prominence of the ivy sign. Total ivy score (TIS) was defined as the sum of the scores from the eight regions and dominant hemispheric ivy sign (DHI) was determined by comparing the ivy scores from each hemisphere. According to the degree of ischemic symptoms, patients were classified into four subgroups: 1) nonspecific symptoms without motor weakness, 2) single transient ischemic attack (TIA), 3) recurrent TIA, or 4) complete stroke. TIS was significantly different as follows: 4.86±2.55 in patients with nonspecific symptoms, 5.89±3.10 in patients with single TIA, 9.60±3.98 in patients with recurrent TIA and 8.37±3.39 in patients with complete stroke (p=0.003). TIS associated with old lesions was significantly higher than those not associated with old lesions (9.35±4.22 vs. 7.49±3.37, p=0.032). We found a significant correlation between DHI and motor symptoms (p=0.001). Because TIS has a strong tendency with severity of ischemic motor symptom and the presence of old lesions, the ivy sign may be useful in predicting severity of disease progression.

Goal-directed fluid therapy: stroke volume optimisation and cardiac dimensions in supine healthy humans

DEFF Research Database (Denmark)

Jans, O.; Tollund, C.; Bundgaard-Nielsen, M.

2008-01-01

BACKGROUND: Based on maximisation of cardiac stroke volume (SV), peri-operative individualised goal-directed fluid therapy improves patient outcome. It remains, however, unknown how fluid therapy by this strategy relates to filling of the heart during supine rest as reference for the anaesthetised...... by thoracic electrical admittance, central venous oxygenation and pressure, and arterial plasma atrial natriuretic peptide. Also, muscle and brain oxygenation were assessed by near infrared spectroscopy (n=7). RESULTS: The HUT reduced the mentioned indices of CBV, the end-diastolic dimensions of the heart...... therapy is that when a maximal SV is established for patients, cardiac pre-load is comparable to that of supine healthy subjects Udgivelsesdato: 2008/4...

Annual review of fluid mechanics. Volume 23

International Nuclear Information System (INIS)

Lumley, J.L.; Van Dyke, M.; Reed, H.L.

1991-01-01

Recent advances in theoretical, experimental, and computational fluid mechanics are discussed in a collection of annual review essays. Topics addressed include Lagrangian ocean studies, drag reduction in nature, the hydraulics of rotating strait and sill flow, analytical methods for the development of Reynolds-stress closures in turbulence, and exact solutions of the Navier-Stokes equations. Consideration is given to the theory of hurricanes, flow phenomena in CVD of thin films, particle-imaging techniques for experimental fluid mechanics, symmetry and symmetry-breaking bifurcations in fluid dynamics, turbulent mixing in stratified fluids, numerical simulation of transition in wall-bounded shear flows, fractals and multifractals in fluid turbulence, and coherent motions in the turbulent boundary layer

Curvature computation in volume-of-fluid method based on point-cloud sampling

Science.gov (United States)

Kassar, Bruno B. M.; Carneiro, João N. E.; Nieckele, Angela O.

2018-01-01

This work proposes a novel approach to compute interface curvature in multiphase flow simulation based on Volume of Fluid (VOF) method. It is well documented in the literature that curvature and normal vector computation in VOF may lack accuracy mainly due to abrupt changes in the volume fraction field across the interfaces. This may cause deterioration on the interface tension forces estimates, often resulting in inaccurate results for interface tension dominated flows. Many techniques have been presented over the last years in order to enhance accuracy in normal vectors and curvature estimates including height functions, parabolic fitting of the volume fraction, reconstructing distance functions, coupling Level Set method with VOF, convolving the volume fraction field with smoothing kernels among others. We propose a novel technique based on a representation of the interface by a cloud of points. The curvatures and the interface normal vectors are computed geometrically at each point of the cloud and projected onto the Eulerian grid in a Front-Tracking manner. Results are compared to benchmark data and significant reduction on spurious currents as well as improvement in the pressure jump are observed. The method was developed in the open source suite OpenFOAM® extending its standard VOF implementation, the interFoam solver.

Blood volume-monitored regulation of ultrafiltration in fluid-overloaded hemodialysis patients: study protocol for a randomized controlled trial

Directory of Open Access Journals (Sweden)

Hecking Manfred

2012-06-01

Full Text Available Abstract Background Data generated with the body composition monitor (BCM, Fresenius show, based on bioimpedance technology, that chronic fluid overload in hemodialysis patients is associated with poor survival. However, removing excess fluid by lowering dry weight can be accompanied by intradialytic and postdialytic complications. Here, we aim at testing the hypothesis that, in comparison to conventional hemodialysis, blood volume-monitored regulation of ultrafiltration and dialysate conductivity (UCR and/or regulation of ultrafiltration and temperature (UTR will decrease complications when ultrafiltration volumes are systematically increased in fluid-overloaded hemodialysis patients. Methods/design BCM measurements yield results on fluid overload (in liters, relative to extracellular water (ECW. In this prospective, multicenter, triple-arm, parallel-group, crossover, randomized, controlled clinical trial, we use BCM measurements, routinely introduced in our three maintenance hemodialysis centers shortly prior to the start of the study, to recruit sixty hemodialysis patients with fluid overload (defined as ≥15% ECW. Patients are randomized 1:1:1 into UCR, UTR and conventional hemodialysis groups. BCM-determined, ‘final’ dry weight is set to normohydration weight −7% of ECW postdialysis, and reached by reducing the previous dry weight, in steps of 0.1 kg per 10 kg body weight, during 12 hemodialysis sessions (one study phase. In case of intradialytic complications, dry weight reduction is decreased, according to a prespecified algorithm. A comparison of intra- and post-dialytic complications among study groups constitutes the primary endpoint. In addition, we will assess relative weight reduction, changes in residual renal function, quality of life measures, and predialysis levels of various laboratory parameters including C-reactive protein, troponin T, and N-terminal pro-B-type natriuretic peptide, before and after the first study

Fluid Mechanics.

Science.gov (United States)

Drazin, Philip

1987-01-01

Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

The finite volume method in computational fluid dynamics an advanced introduction with OpenFOAM and Matlab

CERN Document Server

Moukalled, F; Darwish, M

2016-01-01

This textbook explores both the theoretical foundation of the Finite Volume Method (FVM) and its applications in Computational Fluid Dynamics (CFD). Readers will discover a thorough explanation of the FVM numerics and algorithms used for the simulation of incompressible and compressible fluid flows, along with a detailed examination of the components needed for the development of a collocated unstructured pressure-based CFD solver. Two particular CFD codes are explored. The first is uFVM, a three-dimensional unstructured pressure-based finite volume academic CFD code, implemented within Matlab. The second is OpenFOAM®, an open source framework used in the development of a range of CFD programs for the simulation of industrial scale flow problems. With over 220 figures, numerous examples and more than one hundred exercise on FVM numerics, programming, and applications, this textbook is suitable for use in an introductory course on the FVM, in an advanced course on numerics, and as a reference for CFD programm...

CISM Course on Rotating Fluids

CERN Document Server

1992-01-01

The volume presents a comprehensive overview of rotation effects on fluid behavior, emphasizing non-linear processes. The subject is introduced by giving a range of examples of rotating fluids encountered in geophysics and engineering. This is then followed by a discussion of the relevant scales and parameters of rotating flow, and an introduction to geostrophic balance and vorticity concepts. There are few books on rotating fluids and this volume is, therefore, a welcome addition. It is the first volume which contains a unified view of turbulence in rotating fluids, instability and vortex dynamics. Some aspects of wave motions covered here are not found elsewhere.

Water volume quantitation using nuclear magnetic resonance imaging: application to cerebrospinal fluid

International Nuclear Information System (INIS)

Lecouffe, P.; Huglo, D.; Dubois, P.; Rousseau, J.; Marchandise, X.

1990-01-01

Quantitation in proton NMR imaging is applied to cerebrospinal fluid (CSF). Total intracranial CSF volume was measured from Condon's method: CSF signal was compared with distilled water standard signal in a single sagittal thick slice. Brain signal was reduced to minimum using a 5000/360/400 sequence. Software constraints did not permit easy implementing on imager and uniformity correction was performed on a microcomputer. Accuracy was better than 4%. Total intracranial CSF was found between 91 and 164 ml in 5 healthy volunteers. Extraventricular CSF quantitation appears very improved by this method, but planimetric methods seem better in order to quantify ventricular CSF. This technique is compared to total lung water measurement from proton density according to Mac Lennan's method. Water volume quantitation confirms ability of NMR imaging to quantify biologic parameters but image defects have to be known by strict quality control [fr

Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma

Energy Technology Data Exchange (ETDEWEB)

Goettler, Jens; Preibisch, Christine [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); Lukas, Mathias; Mustafa, Mona; Schwaiger, Markus; Pyka, Thomas [TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kluge, Anne; Kaczmarz, Stephan; Zimmer, Claus [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [TU Muenchen, Department of Neurosurgery, Klinikum rechts der Isar, Munich (Germany); Foerster, Stefan [TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Klinikum Bayreuth, Department of Nuclear Medicine, Bayreuth (Germany)

2017-03-15

{sup 18}F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p < 0.0001). Similarly, significant inter- and intra-individual correlations were observed between FET-slope and rCBV. However, rCBV explained only 12% of the static and 5% of the dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology. (orig.)

Indian Hedgehog in Synovial Fluid Is a Novel Marker for Early Cartilage Lesions in Human Knee Joint

Science.gov (United States)

Zhang, Congming; Wei, Xiaochun; Chen, Chongwei; Cao, Kun; Li, Yongping; Jiao, Qiang; Ding, Juan; Zhou, Jingming; Fleming, Braden C.; Chen, Qian; Shang, Xianwen; Wei, Lei

2014-01-01

To determine whether there is a correlation between the concentration of Indian hedgehog (Ihh) in synovial fluid (SF) and the severity of cartilage damage in the human knee joints, the knee cartilages from patients were classified using the Outer-bridge scoring system and graded using the Modified Mankin score. Expression of Ihh in cartilage and SF samples were analyzed with immunohistochemistry (IHC), western blot, and enzyme-linked immunosorbent assay (ELISA). Furthermore, we detected and compared Ihh protein levels in rat and mice cartilages between normal control and surgery-induced osteoarthritis (OA) group by IHC and fluorescence molecular tomography in vivo respectively. Ihh expression was increased 5.2-fold in OA cartilage, 3.1-fold in relative normal OA cartilage, and 1.71-fold in OA SF compared to normal control samples. The concentrations of Ihh in cartilage and SF samples was significantly increased in early-stage OA samples when compared to normal samples (r = 0.556; p Ihh protein was also an early event in the surgery-induced OA models. Increased Ihh is associated with the severity of OA cartilage damage. Elevated Ihh content in human knee joint synovial fluid correlates with early cartilage lesions. PMID:24786088

Corticospinal tract integrity and lesion volume play different roles in chronic hemiparesis and its improvement through motor practice.

Science.gov (United States)

Sterr, Annette; Dean, Phil J A; Szameitat, Andre J; Conforto, Adriana Bastos; Shen, Shan

2014-05-01

Initial evidence suggests that the integrity of the ipsilesional corticospinal tract (CST) after stroke is strongly related to motor function in the chronic state but not the treatment gain induced by motor rehabilitation. We examined the association of motor status and treatment benefit by testing patients with a wide range of severity of hemiparesis of the left and right upper extremity. Diffusion tensor imaging was performed in 22 patients beyond 12 months after onset of stroke with severe to moderate hemiparesis. Motor function was tested before and after 2 weeks of modified constraint-induced movement therapy. CST integrity, but not lesion volume, correlated with the motor ability measures of the Wolf Motor Function Test and the Motor Activity Log. No differences were found between left and right hemiparesis. Motor performance improved significantly with the treatment regime, and did so equally for patients with left and right arm paresis. However, treatment benefit was not associated with either CST integrity or lesion volume. CST integrity correlated best in this small trial with chronic long-term status but not treatment-induced improvements. The CST may play a different role in the mechanisms mediating long-term outcome compared to those underlying practice-induced gains after a chronic plateau in motor function.

Multiple sclerosis patients lacking oligoclonal bands in the cerebrospinal fluid have less global and regional brain atrophy.

Science.gov (United States)

Ferreira, Daniel; Voevodskaya, Olga; Imrell, Kerstin; Stawiarz, Leszek; Spulber, Gabriela; Wahlund, Lars-Olof; Hillert, Jan; Westman, Eric; Karrenbauer, Virginija Danylaité

2014-09-15

To investigate whether multiple sclerosis (MS) patients with and without cerebrospinal fluid (CSF) oligoclonal immunoglobulin G bands (OCB) differ in brain atrophy. Twenty-eight OCB-negative and thirty-five OCB-positive patients were included. Larger volumes of total CSF and white matter (WM) lesions; smaller gray matter (GM) volume in the basal ganglia, diencephalon, cerebellum, and hippocampus; and smaller WM volume in corpus callosum, periventricular-deep WM, brainstem, and cerebellum, were observed in OCB-positives. OCB-negative patients, known to differ genetically from OCB-positives, are characterized by less global and regional brain atrophy. This finding supports the notion that OCB-negative MS patients may represent a clinically relevant MS subgroup. Copyright © 2014 Elsevier B.V. All rights reserved.

Studies on improvement of diagnosis of neurosurgical lesions by computed tomography, 2

International Nuclear Information System (INIS)

Hirata, Toshifumi

1980-01-01

CT findings of low-density in brain tumor cases were classified into the following 2 groups. (a) low-density lesions within brain tumor, masses. (b) low-density lesions surrounding brain tumors. Group (a) represented either fluid-containing cysts, necrotic masses or low-density tumor parenchyme, as confirmed by operative findings. it was impossible to diagnose pathological nature of low-density lesions merely by analyzing their Hounsfield No. (H-No.), excepting epidermoid, teratoma and arachnoid cyst, in which H-No. was essential for diagnosis. Group (b) was classified into 4 subgroups (grade 0 to III) by modifying Kazner's CT classification of brain edema. In most of malignant tumors (such as glioblastomas, metastatic tumors), wide peritumoral low-density lesions were observed. For example, peritumoral low-density lesions of grade III or II were observed in 87% of glioblastoma cases. But, peritumoral low-density lesions of grade II or III were observed also in benign tumor cases, i.e. in 50% of meningioma cases. In a case of astrocytoma, it was impossible to detect the border of the tumor and perifocal edema, even by means of contrast enhancement. It was confirmed by operative findings, that peritumoral low-density lesions could be caused not only brain edema, but also by enlarged peritumoral subarachnoid space or brain demyelinization due to compression by the tumor. In clinical cases, showing brain edema by CT, and in dogs, in which brain edema was produced by cold injury, the author observed that mean values of H-No. in the region of interest on the lesion side significantly increased after intravenous administration of 10% glycerol solution. It was considered that the observed increase in H-No. was caused by dehydration of the edematous brain and increase in regional cerebral blood volume. (author)

Apparatus and Methods for Fluid Storage and Delivery

Science.gov (United States)

Parazynski, Scott E. (Inventor); Bue, Grant C. (Inventor); Schaefbauer, Mark E. (Inventor); Urban, Kase C. (Inventor)

2014-01-01

An apparatus and method for storing and delivering fluid to a person comprises, in at least one specific embodiment, a fluid reservoir having an internal volume therein with an opening disposed through a first wall or a second wall of the fluid reservoir and located toward a first end of the fluid reservoir. A first portion of a tube can be exterior to the fluid reservoir and a second portion of the tube can be disposed through the opening and within the internal volume. At least one insulation layer can be disposed about the exterior of the first wall of the fluid reservoir. The second wall of the fluid reservoir can be configured for transferring heat from or to the internal volume or from the person. At least one baffle is disposed within the internal volume and connected to the first wall and the second wall of the fluid reservoir.

Prevalence and prognosis of low-volume, oligorecurrent, hormone-sensitive prostate cancer amenable to lesion ablative therapy.

Science.gov (United States)

De Bruycker, Aurélie; Lambert, Bieke; Claeys, Tom; Delrue, Louke; Mbah, Chamberlain; De Meerleer, Gert; Villeirs, Geert; De Vos, Filip; De Man, Kathia; Decaestecker, Karel; Fonteyne, Valérie; Lumen, Nicolaas; Ameye, Filip; Billiet, Ignace; Joniau, Steven; Vanhaverbeke, Friedl; Duthoy, Wim; Ost, Piet

2017-12-01

To describe the anatomical patterns of prostate cancer (PCa) recurrence after primary therapy and to investigate if patients with low-volume disease have a better prognosis as compared with their counterparts. Patients eligible for an 18-F choline positron-emission tomography (PET)-computed tomography (CT) were enrolled in a prospective cohort study. Eligible patients had asymptomatic biochemical recurrence after primary PCa treatment and testosterone levels >50 ng/mL. The number of lesions was counted per scan. Patients with isolated local recurrence (LR) or with ≤3 metastases (with or without LR) were considered to have low-volume disease and patients with >3 metastases to have high-volume disease. Descriptive statistics were used to report recurrences. Cox regression analysis was used to investigate the influence of prognostic variables on the time to developing castration-resistant PCa (CRPC). In 208 patients, 625 sites of recurrence were detected in the lymph nodes (N1/M1a: 30%), the bone (18%), the prostate (bed; 11%), viscera (4%), or a combination of any of the previous (37%). In total, 153 patients (74%) had low-volume recurrence and 55 patients (26%) had high-volume recurrence. The 3-year CRPC-free survival rate for the whole cohort was 79% (95% confidence interval 43-55), 88% for low-volume recurrences and 50% for high-volume recurrences (P < 0.001). Longer PSA doubling time at time of recurrence and low-volume disease were associated with a longer time to CRPC. Three out of four patients with PCa with a 18-F choline PET-CT-detected recurrence have low-volume disease, potentially amenable to local therapy. Patients with low-volume disease have a better prognosis as compared with their counterparts. Lymph node recurrence was the most dominant failure pattern. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Workflow-centred evaluation of an automatic lesion tracking software for chemotherapy monitoring by CT

Energy Technology Data Exchange (ETDEWEB)

Moltz, Jan Hendrik; Peitgen, Heinz-Otto [Fraunhofer MEVIS - Institute for Medical Image Computing, Bremen (Germany); D' Anastasi, Melvin [University Hospital Munich-Grosshadern, Department of Clinical Radiology, Muenchen (Germany); Kiessling, Andreas [University Hospital Giessen and Marburg, Department of Diagnostic Radiology, Marburg (Germany); Pinto dos Santos, Daniel [University Hospital Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany); Schuelke, Christoph [University Hospital Muenster, Institute of Clinical Radiology, Muenster (Germany)

2012-12-15

In chemotherapy monitoring, an estimation of the change in tumour size is an important criterion for the assessment of treatment success. This requires a comparison between corresponding lesions in the baseline and follow-up computed tomography (CT) examinations. We evaluate the clinical benefits of an automatic lesion tracking tool that identifies the target lesions in the follow-up CT study and pre-computes the lesion volumes. Four radiologists performed volumetric follow-up examinations for 52 patients with and without lesion tracking. In total, 139 lung nodules, liver metastases and lymph nodes were given as target lesions. We measured reading time, inter-reader variability in lesion identification and volume measurements, and the amount of manual adjustments of the segmentation results. With lesion tracking, target lesion assessment time decreased by 38 % or 22 s per lesion. Relative volume difference between readers was reduced from 0.171 to 0.1. Segmentation quality was comparable with and without lesion tracking. Our automatic lesion tracking tool can make interpretation of follow-up CT examinations quicker and provide results that are less reader-dependent. (orig.)

Brain atrophy and lesion load predict long term disability in multiple sclerosis

DEFF Research Database (Denmark)

Popescu, Veronica; Agosta, Federica; Hulst, Hanneke E

2013-01-01

To determine whether brain atrophy and lesion volumes predict subsequent 10 year clinical evolution in multiple sclerosis (MS).......To determine whether brain atrophy and lesion volumes predict subsequent 10 year clinical evolution in multiple sclerosis (MS)....

Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation.

Science.gov (United States)

Dostál, P; Senkeřík, M; Pařízková, R; Bareš, D; Zivný, P; Zivná, H; Cerný, V

2010-01-01

Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated groups of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min(-1), tidal volume 10 ml x kg(-1), positive end-expiratory pressure (PEEP) 2 cm H2O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin-6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor-alpha was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury.

Ramses-GPU: Second order MUSCL-Handcock finite volume fluid solver

Science.gov (United States)

Kestener, Pierre

2017-10-01

RamsesGPU is a reimplementation of RAMSES (ascl:1011.007) which drops the adaptive mesh refinement (AMR) features to optimize 3D uniform grid algorithms for modern graphics processor units (GPU) to provide an efficient software package for astrophysics applications that do not need AMR features but do require a very large number of integration time steps. RamsesGPU provides an very efficient C++/CUDA/MPI software implementation of a second order MUSCL-Handcock finite volume fluid solver for compressible hydrodynamics as a magnetohydrodynamics solver based on the constraint transport technique. Other useful modules includes static gravity, dissipative terms (viscosity, resistivity), and forcing source term for turbulence studies, and special care was taken to enhance parallel input/output performance by using state-of-the-art libraries such as HDF5 and parallel-netcdf.

A Finite-Volume approach for compressible single- and two-phase flows in flexible pipelines with fluid-structure interaction

Science.gov (United States)

Daude, F.; Galon, P.

2018-06-01

A Finite-Volume scheme for the numerical computations of compressible single- and two-phase flows in flexible pipelines is proposed based on an approximate Godunov-type approach. The spatial discretization is here obtained using the HLLC scheme. In addition, the numerical treatment of abrupt changes in area and network including several pipelines connected at junctions is also considered. The proposed approach is based on the integral form of the governing equations making it possible to tackle general equations of state. A coupled approach for the resolution of fluid-structure interaction of compressible fluid flowing in flexible pipes is considered. The structural problem is solved using Euler-Bernoulli beam finite elements. The present Finite-Volume method is applied to ideal gas and two-phase steam-water based on the Homogeneous Equilibrium Model (HEM) in conjunction with a tabulated equation of state in order to demonstrate its ability to tackle general equations of state. The extensive application of the scheme for both shock tube and other transient flow problems demonstrates its capability to resolve such problems accurately and robustly. Finally, the proposed 1-D fluid-structure interaction model appears to be computationally efficient.

Impairments in proverb interpretation following focal frontal lobe lesions.

Science.gov (United States)

Murphy, Patrick; Shallice, Tim; Robinson, Gail; MacPherson, Sarah E; Turner, Martha; Woollett, Katherine; Bozzali, Marco; Cipolotti, Lisa

2013-09-01

The proverb interpretation task (PIT) is often used in clinical settings to evaluate frontal "executive" dysfunction. However, only a relatively small number of studies have investigated the relationship between frontal lobe lesions and performance on the PIT. We compared 52 patients with unselected focal frontal lobe lesions with 52 closely matched healthy controls on a proverb interpretation task. Participants also completed a battery of neuropsychological tests, including a fluid intelligence task (Raven's Advanced Progressive Matrices). Lesions were firstly analysed according to a standard left/right sub-division. Secondly, a finer-grained analysis compared the performance of patients with medial, left lateral and right lateral lesions with healthy controls. Thirdly, a contrast of specific frontal subgroups compared the performance of patients with medial lesions with patients with lateral frontal lesions. The results showed that patients with left frontal lesions were significantly impaired on the PIT, while in patients with right frontal lesions the impairments approached significance. Medial frontal patients were the only frontal subgroup impaired on the PIT, relative to healthy controls and lateral frontal patients. Interestingly, an error analysis indicated that a significantly higher number of concrete responses were found in the left lateral subgroup compared to healthy controls. We found no correlation between scores on the PIT and on the fluid intelligence task. Overall our results suggest that specific regions of the frontal lobes contribute to the performance on the PIT. © 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

Gray-white matter and cerebrospinal fluid volume differences in children with Specific Language Impairment and/or Reading Disability.

Science.gov (United States)

Girbau-Massana, Dolors; Garcia-Marti, Gracian; Marti-Bonmati, Luis; Schwartz, Richard G

2014-04-01

We studied gray-white matter and cerebrospinal fluid (CSF) alterations that may be critical for language, through an optimized voxel-based morphometry evaluation in children with Specific Language Impairment (SLI), compared to Typical Language Development (TLD). Ten children with SLI (8;5-10;9) and 14 children with TLD (8;2-11;8) participated. They received a comprehensive language and reading test battery. We also analyzed a subgroup of six children with SLI+RD (Reading Disability). Brain images from 3-Tesla MRIs were analyzed with intelligence, age, gender, and total intracranial volume as covariates. Children with SLI or SLI+RD exhibited a significant lower overall gray matter volume than children with TLD. Particularly, children with SLI showed a significantly lower volume of gray matter compared to children with TLD in the right postcentral parietal gyrus (BA4), and left and right medial occipital gyri (BA19). The group with SLI also exhibited a significantly greater volume of gray matter in the right superior occipital gyrus (BA19), which may reflect a brain reorganization to compensate for their lower volumes at medial occipital gyri. Children with SLI+RD, compared to children with TLD, showed a significantly lower volume of: (a) gray matter in the right postcentral parietal gyrus; and (b) white matter in the right inferior longitudinal fasciculus (RILF), which interconnects the temporal and occipital lobes. Children with TLD exhibited a significantly lower CSF volume than children with SLI and children with SLI+RD respectively, who had somewhat smaller volumes of gray matter allowing for more CSF volume. The significant lower gray matter volume at the right postcentral parietal gyrus and greater cerebrospinal fluid volume may prove to be unique markers for SLI. We discuss the association of poor knowledge/visual representations and language input to brain development. Our comorbid study showed that a significant lower volume of white matter in the right

Percutaneous ethanol injection treatment in benign thyroid lesions: role and efficacy.

Science.gov (United States)

Guglielmi, Rinaldo; Pacella, Claudio Maurizio; Bianchini, Antonio; Bizzarri, Giancarlo; Rinaldi, Roberta; Graziano, Filomena Maria; Petrucci, Lucilla; Toscano, Vincenzo; Palma, Enzo; Poggi, Maurizio; Papini, Enrico

2004-02-01

To establish the role of percutaneous ethanol injection (PEI) treatment in benign thyroid lesions by evaluating: (1) the long-term efficacy and side effects of the treatment, (2) the factors predictive of efficacy of PEI, and (3) the cost effectiveness of the procedure. Fifty-eight recurrent cystic nodules, 95 autonomously functioning nodules (AFTN), and 17 hyperfunctioning nodules causing thyrotoxicosis (toxic nodules) were treated by PEI from 1990 to 1996 in our center. Ultrasound (US) and color flow doppler (CFD) examinations were carried out before and after each treatment. In patients with AFTN, serum thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb) levels were tested before and after PEI. All patients were independently reexamined by two external reviewers after a minimum follow-up of 5 years (median, 6.9 years). The median number of treatments was 2.0 (range, 1.0-4.0) for cystic nodules, 4 (range, 2.0-6.0) for AFTN, and 5 (range, 3.0-7.0) for toxic nodules. At the 5-year evaluation cystic nodules showed a volume reduction greater than 75% versus baseline in 86.2% of cases and an improvement of local symptoms in 91.4% of cases. AFTN presented serum TSH within normal limits in 60.0% of patients. Toxic nodules showed a detectable serum TSH and normal FT3 and FT4 values in 35.3% of cases. Two cases of transient dysphonia were observed. In cystic lesions no significant correlation was found between the baseline and the final volume (r2 = 0.17) and no significant predictor of treatment efficacy was found. However, unilocularity was associated with a lower number of treatments than multilocularity (median, 2.0 vs. 3.0). Independent predictors of clinical efficacy in both AFTN and toxic nodules were a baseline volume less than 5.0 mL and a fluid component greater than 30% (odds ratio [OR] = 6.1 and 3.3, respectively). Most recurrent cystic lesions of the thyroid can be cured by PEI, which should become the

Cavitation and gas-liquid flow in fluid machinery and devices. FED-Volume 190

International Nuclear Information System (INIS)

O'Hern, T.J.; Kim, J.H.; Morgan, W.B.; Furuya, O.

1994-01-01

Cavitation and gas-liquid two-phase flow have remained important areas in many industrial applications and constantly provided challenges for academic researchers and industrial practitioners alike. Cavitation and two-phase flow commonly occur in fluid machinery such as pumps, propellers, and fluid devices such as orifices, valves, and diffusers. Cavitation not only degrades the performance of these machines and devices but deteriorates the materials. Gas-liquid two-phase flow has also been known to degrade the performance of pumps and propellers and can often induce an instability. The industrial applications of cavitation and two-phase flow can be found in power plants, ship propellers, hydrofoils, and aerospace equipment, to name but a few. The papers presented in this volume reflect the variety and richness of cavitation and gas-liquid two-phase flow in various flow transporting components and the increasing role they play in modern and conventional technologies. Separate abstracts were prepared for 35 papers in this book

Fluid overload in the ICU: evaluation and management.

Science.gov (United States)

Claure-Del Granado, Rolando; Mehta, Ravindra L

2016-08-02

Fluid overload is frequently found in acute kidney injury patients in critical care units. Recent studies have shown the relationship of fluid overload with adverse outcomes; hence, manage and optimization of fluid balance becomes a central component of the management of critically ill patients. In critically ill patients, in order to restore cardiac output, systemic blood pressure and renal perfusion an adequate fluid resuscitation is essential. Achieving an appropriate level of volume management requires knowledge of the underlying pathophysiology, evaluation of volume status, and selection of appropriate solution for volume repletion, and maintenance and modulation of the tissue perfusion. Numerous recent studies have established a correlation between fluid overload and mortality in critically ill patients. Fluid overload recognition and assessment requires an accurate documentation of intakes and outputs; yet, there is a wide difference in how it is evaluated, reviewed and utilized. Accurate volume status evaluation is essential for appropriate therapy since errors of volume evaluation can result in either in lack of essential treatment or unnecessary fluid administration, and both scenarios are associated with increased mortality. There are several methods to evaluate fluid status; however, most of the tests currently used are fairly inaccurate. Diuretics, especially loop diuretics, remain a valid therapeutic alternative. Fluid overload refractory to medical therapy requires the application of extracorporeal therapies. In critically ill patients, fluid overload is related to increased mortality and also lead to several complications like pulmonary edema, cardiac failure, delayed wound healing, tissue breakdown, and impaired bowel function. Therefore, the evaluation of volume status is crucial in the early management of critically ill patients. Diuretics are frequently used as an initial therapy; however, due to their limited effectiveness the use of continuous

Volume transmission of beta-endorphin via the cerebrospinal fluid; a review

Directory of Open Access Journals (Sweden)

Veening Jan G

2012-08-01

Full Text Available Abstract There is increasing evidence that non-synaptic communication by volume transmission in the flowing CSF plays an important role in neural mechanisms, especially for extending the duration of behavioral effects. In the present review, we explore the mechanisms involved in the behavioral and physiological effects of β-endorphin (β-END, especially those involving the cerebrospinal fluid (CSF, as a message transport system to reach distant brain areas. The major source of β-END are the pro-opio-melano-cortin (POMC neurons, located in the arcuate hypothalamic nucleus (ARH, bordering the 3rd ventricle. In addition, numerous varicose β-END-immunoreactive fibers are situated close to the ventricular surfaces. In the present paper we surveyed the evidence that volume transmission via the CSF can be considered as an option for messages to reach remote brain areas. Some of the points discussed in the present review are: release mechanisms of β-END, independence of peripheral versus central levels, central β-END migration over considerable distances, behavioral effects of β-END depend on location of ventricular administration, and abundance of mu and delta opioid receptors in the periventricular regions of the brain.

A toolbox for multiple sclerosis lesion segmentation

International Nuclear Information System (INIS)

Roura, Eloy; Oliver, Arnau; Valverde, Sergi; Llado, Xavier; Cabezas, Mariano; Pareto, Deborah; Rovira, Alex; Vilanova, Joan C.; Ramio-Torrenta, Lluis

2015-01-01

Lesion segmentation plays an important role in the diagnosis and follow-up of multiple sclerosis (MS). This task is very time-consuming and subject to intra- and inter-rater variability. In this paper, we present a new tool for automated MS lesion segmentation using T1w and fluid-attenuated inversion recovery (FLAIR) images. Our approach is based on two main steps, initial brain tissue segmentation according to the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) performed in T1w images, followed by a second step where the lesions are segmented as outliers to the normal apparent GM brain tissue on the FLAIR image. The tool has been validated using data from more than 100 MS patients acquired with different scanners and at different magnetic field strengths. Quantitative evaluation provided a better performance in terms of precision while maintaining similar results on sensitivity and Dice similarity measures compared with those of other approaches. Our tool is implemented as a publicly available SPM8/12 extension that can be used by both the medical and research communities. (orig.)

A toolbox for multiple sclerosis lesion segmentation

Energy Technology Data Exchange (ETDEWEB)

Roura, Eloy; Oliver, Arnau; Valverde, Sergi; Llado, Xavier [University of Girona, Computer Vision and Robotics Group, Girona (Spain); Cabezas, Mariano; Pareto, Deborah; Rovira, Alex [Vall d' Hebron University Hospital, Magnetic Resonance Unit, Dept. of Radiology, Barcelona (Spain); Vilanova, Joan C. [Girona Magnetic Resonance Center, Girona (Spain); Ramio-Torrenta, Lluis [Dr. Josep Trueta University Hospital, Institut d' Investigacio Biomedica de Girona, Multiple Sclerosis and Neuroimmunology Unit, Girona (Spain)

2015-10-15

Lesion segmentation plays an important role in the diagnosis and follow-up of multiple sclerosis (MS). This task is very time-consuming and subject to intra- and inter-rater variability. In this paper, we present a new tool for automated MS lesion segmentation using T1w and fluid-attenuated inversion recovery (FLAIR) images. Our approach is based on two main steps, initial brain tissue segmentation according to the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) performed in T1w images, followed by a second step where the lesions are segmented as outliers to the normal apparent GM brain tissue on the FLAIR image. The tool has been validated using data from more than 100 MS patients acquired with different scanners and at different magnetic field strengths. Quantitative evaluation provided a better performance in terms of precision while maintaining similar results on sensitivity and Dice similarity measures compared with those of other approaches. Our tool is implemented as a publicly available SPM8/12 extension that can be used by both the medical and research communities. (orig.)

The effect of magnetisation transfer contrast on cerebrospinal fluid on motion artefacts on fluid-attenuated inversion-recovery images

International Nuclear Information System (INIS)

Aprile, I.; Principi, M.; Ottaviano, P.; Scapeccia, M.

2003-01-01

We assessed possible advantages of the use of fluid-attenuated inversion-recovery (FLAIR) sequences with magnetisation-transfer contrast (MTC) over conventional FLAIR images. We carried out cranial MRI at 1 tesla on 50 patients with both sequences. In nine patients with multiple sclerosis (MS) we performed a quantitative comparison of the two sequences, looking at the contrast-to-noise ratio between lesions and normal white matter and counting the number of lesions shown using each method. A qualitative comparison on all patients consisted of the analysis of the appearance of the normal parenchyma, of any lesions, and of artefacts, with particular reference to cerebrospinal fluid (CSF) motion artefacts. The quantitative analysis showed no meaningful difference between the two sequences. The cerebral parenchyma and lesions appeared substantially the same with both techniques. With FLAIR MTC there was a clear, and consistent reduction in CSF motion artefacts. FLAIR MTC sequences can usefully be used in place of the conventional sequence at 1 tesla. (orig.)

The effect of type and volume of fluid hydration on labor duration of nulliparous women: a randomized controlled trial.

Science.gov (United States)

Garmi, Gali; Zuarez-Easton, Sivan; Zafran, Noah; Ohel, Iris; Berkovich, Ilanit; Salim, Raed

2017-06-01

Type and volume of fluid administered for intrapartum maintenance had been reported to differently affect labor length, delivery mode, and cord artery pH and glucose level. We aimed to compare the effect of three different fluid regimens on labor duration. In a randomized trial, healthy nulliparous in labor were randomized into one of three intravenous fluid regimens: group 1, the reference group, lactated Ringer's solution infused at a rate of 125 mL/h; group 2, lactated Ringer's solution infused at a rate of 250 mL/h; group 3, 0.9% saline solution boosted with 5% glucose, infused at a rate of 125 mL/h. The primary outcome was labor length from enrollment until delivery. Between December 2010 and July 2015, 300 women were randomized to one of the three groups. Demographic and baseline obstetric characteristics were comparable between the groups. There was no significant difference in the time from enrollment to delivery (p = 0.62). Furthermore, there were no significant differences in second stage duration (p = 0.73), mode of delivery (p = 0.21), cord artery pH and glucose level between the groups. Increasing the intravenous volume of lactated Ringer's solution or substituting to fluid containing 5% glucose solution does not affect labor length. ClinicalTrials.gov, http://www.clinicaltrials.gov , NCT01242293.

The fluid dynamics of climate

CERN Document Server

Palazzi, Elisa; Fraedrich, Klaus

2016-01-01

This volume provides an overview of the fluid aspects of the climate system, focusing on basic aspects as well as recent research developments. It will bring together contributions from diverse fields of the physical, mathematical and engineering sciences. The volume will be useful to doctorate students, postdocs and researchers working on different aspects of atmospheric, oceanic and environmental fluid dynamics. It will also be of interest to researchers interested in quantitatively understanding how fluid dynamics can be applied to the climate system, and to climate scientists willing to gain a deeper insight into the fluid mechanics underlying climate processes.

Quantification of osteolytic bone lesions in a preclinical rat trial

Science.gov (United States)

Fränzle, Andrea; Bretschi, Maren; Bäuerle, Tobias; Giske, Kristina; Hillengass, Jens; Bendl, Rolf

2013-10-01

In breast cancer, most of the patients who died, have developed bone metastasis as disease progression. Bone metastases in case of breast cancer are mainly bone destructive (osteolytic). To understand pathogenesis and to analyse response to different treatments, animal models, in our case rats, are examined. For assessment of treatment response to bone remodelling therapies exact segmentations of osteolytic lesions are needed. Manual segmentations are not only time-consuming but lack in reproducibility. Computerized segmentation tools are essential. In this paper we present an approach for the computerized quantification of osteolytic lesion volumes using a comparison to a healthy reference model. The presented qualitative and quantitative evaluation of the reconstructed bone volumes show, that the automatically segmented lesion volumes complete missing bone in a reasonable way.

Stroke subtype classification by geometrical descriptors of lesion shape.

Directory of Open Access Journals (Sweden)

Bastian Cheng

Full Text Available Inference of etiology from lesion pattern in acute magnetic resonance imaging is valuable for management and prognosis of acute stroke patients. This study aims to assess the value of three-dimensional geometrical lesion-shape descriptors for stroke-subtype classification, specifically regarding stroke of cardioembolic origin.Stroke Etiology was classified according to ASCOD in retrospectively selected patients with acute stroke. Lesions were segmented on diffusion-weighed datasets, and descriptors of lesion shape quantified: surface area, sphericity, bounding box volume, and ratio between bounding box and lesion volume. Morphological measures were compared between stroke subtypes classified by ASCOD and between patients with embolic stroke of cardiac and non-cardiac source.150 patients (mean age 77 years; 95% CI, 65-80 years; median NIHSS 6, range 0-22 were included. Group comparison of lesion shape measures demonstrated that lesions caused by small-vessel disease were smaller and more spherical compared to other stroke subtypes. No significant differences of morphological measures were detected between patients with cardioembolic and non-cardioembolic stroke.Stroke lesions caused by small vessel disease can be distinguished from other stroke lesions based on distinctive morphological properties. However, within the group of embolic strokes, etiology could not be inferred from the morphology measures studied in our analysis.

Development of a compressive surface capturing formulation for modelling free-surface flow by using the volume-of-fluid approach

CSIR Research Space (South Africa)

Heyns, Johan A

2012-06-01

Full Text Available combines a blended higher resolution scheme with the addition of an artificial compressive term to the volume-of-fluid equation. This reduces the numerical smearing of the interface associated with explicit higher resolution schemes while limiting...

Automated detection of Lupus white matter lesions in MRI

Directory of Open Access Journals (Sweden)

Eloy Roura Perez

2016-08-01

Full Text Available Brain magnetic resonance imaging provides detailed information which can be used to detect and segment white matter lesions (WML. In this work we propose an approach to automatically segment WML in Lupus patients by using T1w and fluid-attenuated inversion recovery (FLAIR images. Lupus WML appear as small focal abnormal tissue observed as hyperintensities in the FLAIR images. The quantification of these WML is a key factor for the stratification of lupus patients and therefore both lesion detection and segmentation play an important role. In our approach, the T1w image is first used to classify the three main tissues of the brain, white matter (WM, gray matter (GM and cerebrospinal fluid (CSF, while the FLAIR image is then used to detect focal WML as outliers of its GM intensity distribution. A set of post-processing steps based on lesion size, tissue neighborhood, and location are used to refine the lesion candidates. The proposal is evaluated on 20 patients, presenting qualitative and quantitative results in terms of precision and sensitivity of lesion detection (True Positive Rate (62% and Positive Prediction Value (80% respectively as well as segmentation accuracy (Dice Similarity Coefficient (72%. Obtained results illustrate the validity of the approach to automatically detect and segment lupus lesions. Besides, our approach is publicly available as a SPM8/12 toolbox extension with a simple parameter configuration.

Differences in prefrontal, limbic, and white matter lesion volumes according to cognitive status in elderly patients with first-onset subsyndromal depression.

Directory of Open Access Journals (Sweden)

Jun-Young Lee

Full Text Available The purpose of this preliminary study was to test the hypothesis that subsyndromal depression is associated with the volume of medial prefrontal regional gray matter and that of white matter lesions (WMLs in the brains of cognitively normal older people. We also explored the relationships between subsyndromal depression and medial prefrontal regional gray matter volume, limbic regional gray matter volume, and lobar WMLs in the brains of patients with mild cognitive impairment (MCI and Alzheimer's disease (AD. We performed a cross-sectional study comparing patients with subsyndromal depression and nondepressed controls with normal cognition (n = 59, MCI (n = 27, and AD (n = 27, adjusting for sex, age, years of education, and results of the Mini-Mental State Examination. Frontal WML volume was greater, and right medial orbitofrontal cortical volume was smaller in cognitively normal participants with subsyndromal depression than in those without subsyndromal depression. No volume differences were observed in medial prefrontal, limbic, or WML volumes according to the presence of subsyndromal depression in cognitively impaired patients. The absence of these changes in patients with MCI and AD suggests that brain changes associated with AD pathology may override the changes associated with subsyndromal depression.

Volume-of-fluid simulations in microfluidic T-junction devices: Influence of viscosity ratio on droplet size

Science.gov (United States)

Nekouei, Mehdi; Vanapalli, Siva A.

2017-03-01

We used volume-of-fluid (VOF) method to perform three-dimensional numerical simulations of droplet formation of Newtonian fluids in microfluidic T-junction devices. To evaluate the performance of the VOF method we examined the regimes of drop formation and determined droplet size as a function of system parameters. Comparison of the simulation results with four sets of experimental data from the literature showed good agreement, validating the VOF method. Motivated by the lack of adequate studies investigating the influence of viscosity ratio (λ) on the generated droplet size, we mapped the dependence of drop volume on capillary number (0.001 1. In addition, we find that at a given capillary number, the size of droplets does not vary appreciably when λ 1. We develop an analytical model for predicting the droplet size that includes a viscosity-dependent breakup time for the dispersed phase. This improved model successfully predicts the effects of the viscosity ratio observed in simulations. Results from this study are useful for the design of lab-on-chip technologies and manufacture of microfluidic emulsions, where there is a need to know how system parameters influence the droplet size.

Effect of Rehydration Fluid Osmolality on Plasma Volume and Vasopressin in Resting Dehydrated Men

Science.gov (United States)

Geelen, Ghislaine; Greenleaf, J. E.; Keil, L. C.; Wade, Charles E. (Technical Monitor)

1994-01-01

Elevated plasma vasopressin concentration [PVP], which may act as a dipsogen, decreases promptly following the ingestion of fluids in many mammals including humans. The purpose for this study was to determine whether fluids of varied electrolyte and carbohydrate composition and osmolality (Osm] would modify post-drinking decreases in [PVP] which could be attributed to interaction with plasma volume (PV)- or fluid-electrolyte interactive hormones. Five men (23-41 yr, 78.0 +/- SD 8.2 kg), water deprived for 24 h, drank six fluids (12 ml/kg, at 16.5C in 4.0-6.2 min): water (30 m0sm/kg), NaCl (70 mOsm/kg), NaCl + NaCitrate (270 mOsm/kg), NaCl + 9.7% glucose (650 mOsm/kg), and two commercial drinks containing various ionic and carbohydrate contents (380 and 390 mOsm/kg). Blood (20 ml/sample) was drawn at -5 min before and at +3, +9, +15, +30, and +70 min after drinking. Heart rate, blood pressures, and plasma renin activity, {Na+], [K+], [Osm], aldosterone, atrial natriuretic peptide, and epinephrine concentrations were unchanged after drinking. Post-drinking [PVP] decreased from 1.7 - 3.7 pg/ml within 3 min with all fluids independently of their composition, [Osm], or delta PV; with maximal depression to 0.1-0.7 pg/ml (p<0.05) by 15 min. The continued [PVP] depression with all fluids from 15 to 70 min was accompanied by unchanged plasma (Osm] but 1.8-7.6% increases (p<0.05) in PV with 3) fluids (2 commercial and NaCitrate) and no change with the others. Percent changes in mean [PVP] and plasma norepinephrine concentrations [PNE] at 15 min correlated -0.70 (P<0.10) suggesting that about half the variability in [PVP I I depression was associated with [PNE]. Thus, part of the mechanism for post-drinking [PVP] depression may involve a drinking stimulated norepinephrine (neural) factor.

Numerical investigation on lateral migration and lift force of single bubble in simple shear flow in low viscosity fluid using volume of fluid method

International Nuclear Information System (INIS)

Zhongchun, Li; Xiaoming, Song; Shengyao, Jiang; Jiyang, Yu

2014-01-01

Highlights: • A VOF simulation of bubble in low viscosity fluid was conducted. • Lift force in different viscosity fluid had different lateral migration characteristics. • Bubble with different size migrated to different direction. • Shear stress triggered the bubble deformation process and the bubble deformation came along with the oscillation behaviors. - Abstract: Two phase flow systems have been widely used in industrial engineering. Phase distribution characteristics are vital to the safety operation and optimization design of two phase flow systems. Lift force has been known as perpendicular to the bubbles’ moving direction, which is one of the mechanisms of interfacial momentum transfer. While most widely used lift force correlations, such as the correlation of Tomiyama et al. (2002), were obtained by experimentally tracking single bubble trajectories in high viscosity glycerol–water mixture, the applicability of these models into low viscosity fluid, such as water in nuclear engineering system, needs to be further evaluated. In the present paper, bubble in low viscosity fluid in shear flow was investigated in a full 3D numerical simulation and the volume of fluid (VOF) method was applied to capture the interface. The fluid parameter: fluid viscosity, bubble parameter: diameter and external flow parameters: shear stress magnitude and liquid velocity were examined. Comparing with bubble in high viscosity shear flow and bubble in low viscosity still flow, relative large bubble in low viscosity shear flow keep an oscillation way towards the moving wall and experienced a shape deformation process. The oscillation amplitude increased as the viscosity of fluid decreased. Small bubble migrated to the static wall in a line with larger migration velocity than that in high viscosity fluid and no deformation occurred. The shear stress triggered the oscillation behaviors while it had no direct influence with the behavior. The liquid velocity had no effect on

Noninvasive pulse pressure variation and stroke volume variation to predict fluid responsiveness at multiple thresholds : a prospective observational study

NARCIS (Netherlands)

Vos, Jaap Jan; Poterman, Marieke; Papineau Salm, Pieternel; Van Amsterdam, Kai; Struys, Michel M. R. F.; Scheeren, Thomas W. L.; Kalmar, Alain F.

2015-01-01

Pulse pressure variation (PPV) and stroke volume variation (SVV) are dynamic preload variables that can be measured noninvasively to assess fluid responsiveness (FR) in anesthetized patients with mechanical ventilation. Few studies have examined the effectiveness of predicting FR according to the

The Automated Breast Volume Scanner (ABVS: initial experiences in lesion detection compared with conventional handheld B-mode ultrasound: a pilot study of 50 cases

Directory of Open Access Journals (Sweden)

Wojcinski S

2011-10-01

Full Text Available Sebastian Wojcinski1, Andre Farrokh1, Ursula Hille2, Jakub Wiskirchen3, Samuel Gyapong1, Amr A Soliman1,4, Friedrich Degenhardt1, Peter Hillemanns21Department of OB/GYN, Franziskus Hospital, Bielefeld, Germany; 2Department of OB/GYN, Hannover Medical School, Hannover, Germany; 3Department of Radiology, Franziskus Hospital, Bielefeld, Germany; 4Department of OB/GYN, Faculty of Medicine, University of Alexandria, Alexandria, EgyptAbstract: The idea of an automated whole breast ultrasound was developed three decades ago. We present our initial experiences with the latest technical advance in this technique, the automated breast volume scanner (ABVS ACUSON S2000TM. Volume data sets were collected from 50 patients and a database containing 23 women with no detectable lesions in conventional ultrasound (BI-RADS®-US 1, 13 women with clearly benign lesions (BI-RADS®-US 2, and 14 women with known breast cancer (BI-RADS®-US 5 was created. An independent examiner evaluated the ABVS data on a separate workstation without any prior knowledge of the patients’ histories. The diagnostic accuracy for the experimental ABVS was 66.0% (95% confidence interval [CI]: 52.9–79.1. The independent examiner detected all breast cancers in the volume data resulting in a calculated sensitivity of 100% in the described setting (95% CI: 73.2%–100%. After the ABVS examination, there were a high number of requests for second-look ultrasounds in 47% (95% CI: 30.9–63.5 of the healthy women (with either a clearly benign lesion or no breast lesions at all in conventional handheld ultrasound. Therefore, the specificity remained at 52.8% (95% CI: 35.7–69.2. When comparing the concordance of the ABVS with the gold standard (conventional handheld ultrasound, Cohen’s Kappa value as an estimation of the inter-rater reliability was κ = 0.37, indicating fair agreement. In conclusion, the ABVS must still be regarded as an experimental technique for breast ultrasound, which

Numerical study of shear thickening fluid with discrete particles embedded in a base fluid

Directory of Open Access Journals (Sweden)

W Zhu

2016-09-01

Full Text Available The Shear Thickening Fluid (STF is a dilatant material, which displays non-Newtonian characteristics in its unique ability to transit from a low viscosity fluid to a high viscosity fluid. The research performed investigates the STF behavior by modeling and simulation of the interaction between the base flow and embedded rigid particles when subjected to shear stress. The model considered the Lagrangian description of the rigid particles and the Eulerian description of fluid flow. The numerical analysis investigated key parameters such as applied flow acceleration, particle distribution and arrangement, volume concentration of particles, particle size, shape and their behavior in a Newtonian and non-Newtonian fluid base. The fluid-particle interaction model showed that the arrangement, size, shape and volume concentration of the particles had a significant effect on the behavior of the STF. Although non-conclusive, the addition of particles in non-Newtonian fluids showed a promising trend of improved shear thickening effects at high shear strain rates.

Effect of dependency versus nondependency on lung lesion visualization

International Nuclear Information System (INIS)

Pechman, R.D. Jr.

1987-01-01

Paraffin blocks and mineral oil were used as a model to determine the effect of dependency versus nondependency on radiographic visualization of lung lesions in lateral thoracic radiographs. It was concluded that the increased opacity of the material surrounding the lesion, not contact between the heart and the lesion, was responsible for the inability to detect lung disease in the dependent lung. The results were tested in dogs with pneumonia in the right middle lung lobe. When the dog was in right lateral recumbency, the dependent right lung was increased in opacity and decreased in volume and the pulmonary lesion was difficult to detect. When the dog was in left lateral recumbency, the non dependent right lung was increased in volume and decreased in opacity and the pulmonary disease was clearly visible. A single recumbent lateral radiograph must not be used to assess a dog with suspected lung disease because lesions in the dependent lung lobes may not be detected

Detection of Treponema pallidum subsp. pallidum from Skin Lesions, Serum, and Cerebrospinal Fluid in an Infant with Congenital Syphilis after Clindamycin Treatment of the Mother during Pregnancy▿

Science.gov (United States)

Woznicová, Vladana; Šmajs, David; Wechsler, Dan; Matějková, Petra; Flasarová, Magdalena

2007-01-01

We report here a case of congenital syphilis in a newborn after clindamycin treatment in pregnancy. Using PCR detection of tmpC (TP0319) and DNA sequencing of the genes TP0136 and TP0548, DNA sequences identical to Treponema pallidum subsp. pallidum strain SS14 were detected in the infant's skin lesions, serum, and cerebrospinal fluid. PMID:17151205

Computational Fluid Dynamics

International Nuclear Information System (INIS)

Myeong, Hyeon Guk

1999-06-01

This book deals with computational fluid dynamics with basic and history of numerical fluid dynamics, introduction of finite volume method using one-dimensional heat conduction equation, solution of two-dimensional heat conduction equation, solution of Navier-Stokes equation, fluid with heat transport, turbulent flow and turbulent model, Navier-Stokes solution by generalized coordinate system such as coordinate conversion, conversion of basic equation, program and example of calculation, application of abnormal problem and high speed solution of numerical fluid dynamics.

Oral Administration of Pentoxifylline Reduces Endometriosis-Like Lesions in a Nude Mouse Model.

Science.gov (United States)

Perelló, Maria; González-Foruria, Iñaki; Castillo, Paola; Martínez-Florensa, Mario; Lozano, Francisco; Balasch, Juan; Carmona, Francisco

2017-06-01

Recent reports consider endometriosis to be an immunological disorder, thus suggesting potential efficacy of immunomodulators for its treatment. The aim of this study was to assess the effects of oral administration of pentoxifylline on endometriosis-like lesions in a heterologous mice model. Human endometrial tissue obtained from women (n = 5) undergoing surgery for benign conditions was implanted in nude female mice (n = 30). The animals were distributed into 3 experimental groups receiving: saline 0.1 mL/d (control, group 1); pentoxifylline 100 mg/kg/d (group 2), and pentoxifylline 200 mg/kg/d (group 3). After 28 days, the number of implants and the total volume of surgically extracted tissue were recorded. Immunohistochemical analysis was performed to assess the area of endometriosis and vascularization of endometriosis-like lesions. Cytokine levels in peritoneal fluid samples were measured. Macroscopic quantification showed a trend to dose-dependent reduction in the number of the endometriosis-like lesions after 28 days. The volume was significantly reduced in group 3 versus group 2 and controls (399.10 ± 120.68 mm 3 vs 276.75 ± 94.30 mm 3 and 145.33 ± 38.20 mm 3 , respectively; P = .04). Similarly, the mean area of endometriosis was significantly lower in group 3 (0.12 ± 0.08 mm 2 ) versus group 2 (1.35 ± 0.43 mm 2 ) and control (2.84 ± 0.60 mm 2 ; P = .001). Vascularization and cytokine levels were also reduced posttreatment. Our results suggest that the oral administration of pentoxifylline may be an alternative to current therapies for endometriosis. Nonetheless, further studies are required.

Strategic lesions in the anterior thalamic radiation and apathy in early Alzheimer's disease.

Directory of Open Access Journals (Sweden)

Mario Torso

Full Text Available Behavioural disorders and psychological symptoms of Dementia (BPSD are commonly observed in Alzheimer's disease (AD, and strongly contribute to increasing patients' disability. Using voxel-lesion-symptom mapping (VLSM, we investigated the impact of white matter lesions (WMLs on the severity of BPSD in patients with amnestic mild cognitive impairment (a-MCI.Thirty-one a-MCI patients (with a conversion rate to AD of 32% at 2 year follow-up and 26 healthy controls underwent magnetic resonance imaging (MRI examination at 3T, including T2-weighted and fluid-attenuated-inversion-recovery images, and T1-weighted volumes. In the patient group, BPSD was assessed using the Neuropsychiatric Inventory-12. After quantitative definition of WMLs, their distribution was investigated, without an a priori anatomical hypothesis, against patients' behavioural symptoms. Unbiased regional grey matter volumetrics was also used to assess the contribution of grey matter atrophy to BPSD.Apathy, irritability, depression/dysphoria, anxiety and agitation were shown to be the most common symptoms in the patient sample. Despite a more widespread anatomical distribution, a-MCI patients did not differ from controls in WML volumes. VLSM revealed a strict association between the presence of lesions in the anterior thalamic radiations (ATRs and the severity of apathy. Regional grey matter atrophy did not account for any BPSD.This study indicates that damage to the ATRs is strategic for the occurrence of apathy in patients with a-MCI. Disconnection between the prefrontal cortex and the mediodorsal and anterior thalamic nuclei might represent the pathophysiological substrate for apathy, which is one of the most common psychopathological symptoms observed in dementia.

Diagnosis of drowning using post-mortem computed tomography based on the volume and density of fluid accumulation in the maxillary and sphenoid sinuses.

Science.gov (United States)

Kawasumi, Yusuke; Kawabata, Tomoyoshi; Sugai, Yusuke; Usui, Akihito; Hosokai, Yoshiyuki; Sato, Miho; Saito, Haruo; Ishibashi, Tadashi; Hayashizaki, Yoshie; Funayama, Masato

2013-10-01

Recent studies have reported that drowning victims frequently have fluid accumulation in the paranasal sinuses, most notably the maxillary and sphenoid sinuses. However, in our previous study, many non-drowning victims also had fluid accumulation in the sinuses. Therefore, we evaluated the qualitative difference in fluid accumulation between drowning and non-drowning cases in the present study. Thirty-eight drowning and 73 non-drowning cases were investigated retrospectively. The fluid volume and density of each case were calculated using a DICOM workstation. The drowning cases were compared with the non-drowning cases using the Mann-Whitney U-test because the data showed non-normal distribution. The median fluid volume was 1.82 (range 0.02-11.7) ml in the drowning cases and 0.49 (0.03-8.7) ml in the non-drowning cases, and the median fluid density was 22 (-14 to 66) and 39 (-65 to 77) HU, respectively. Both volume and density differed significantly between the drowning and non-drowning cases (p=0.001, p=0.0007). Regarding cut-off levels in the ROC analysis, the points on the ROC curve closest (0, 1) were 1.03ml (sensitivity 68%, specificity 68%, PPV 53%, NPV 81%) and 27.5 HU (61%, 70%, 51%, 77%). The Youden indices were 1.03ml and 37.8 HU (84%, 51%, 47%, 86%). When the cut-off level was set at 1.03ml and 27.5HU, the sensitivity was 42%, specificity 45%, PPV 29% and NPV 60%. When the cut-off level was set at 1.03ml and 37.8HU, sensitivity was 58%, specificity 32%, PPV 31% and NPV 59%. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Total volume and composition of fluid intake and mortality in older women: a cohort study

Science.gov (United States)

Lim, Wai H; Wong, Germaine; Lewis, Joshua R; Lok, Charmaine E; Polkinghorne, Kevan R; Hodgson, Jonathan; Lim, Ee M; Prince, Richard L

2017-01-01

Objectives The health benefits of ‘drinking at least 8 glasses of water a day” in healthy individuals are largely unproven. We aimed to examine the relationship between total fluid and the sources of fluid consumption, risk of rapid renal decline, cardiovascular disease (CVD) mortality and all-cause mortality in elderly women. Design, setting and participants We conducted a longitudinal analysis of a population-based cohort study of 1055 women aged ≥70 years residing in Australia. Main outcome measures The associations between total daily fluid intake (defined as total volume of beverage excluding alcohol and milk) and the types of fluid (water, black tea, coffee, milk and other fluids) measured as cups per day and rapid renal decline, CVD and all-cause mortality were assessed using adjusted logistic and Cox regression analyses. Results Over a follow-up period of 10 years, 70 (6.6%) experienced rapid renal decline and 362 (34.4%) died, of which 142 (13.5%) deaths were attributed to CVD. The median (IQR) intake of total fluid was 10.4 (8.5–12.5) cups per day, with water (median (IQR) 4 (2–6) cups per day) and black tea (median (IQR) 3 (1–4) cups per day) being the most frequent type of fluid consumed. Every cup per day higher intake of black tea was associated with adjusted HRs of 0.90 (95% CI 0.81 to 0.99) and 0.92 (95% CI 0.86 to 0.98) for CVD mortality and all-cause mortality, respectively. There were no associations between black tea intake and rapid renal decline, or between the quantity or type of other fluids, including water intake, and any clinical outcomes. Conclusions Habitual higher intake of black tea may potentially improve long-term health outcomes, independent of treating traditional CVD risk factors, but validation of our study findings is essential. PMID:28341683

Finite volume multigrid method of the planar contraction flow of a viscoelastic fluid

Science.gov (United States)

Moatssime, H. Al; Esselaoui, D.; Hakim, A.; Raghay, S.

2001-08-01

This paper reports on a numerical algorithm for the steady flow of viscoelastic fluid. The conservative and constitutive equations are solved using the finite volume method (FVM) with a hybrid scheme for the velocities and first-order upwind approximation for the viscoelastic stress. A non-uniform staggered grid system is used. The iterative SIMPLE algorithm is employed to relax the coupled momentum and continuity equations. The non-linear algebraic equations over the flow domain are solved iteratively by the symmetrical coupled Gauss-Seidel (SCGS) method. In both, the full approximation storage (FAS) multigrid algorithm is used. An Oldroyd-B fluid model was selected for the calculation. Results are reported for planar 4:1 abrupt contraction at various Weissenberg numbers. The solutions are found to be stable and smooth. The solutions show that at high Weissenberg number the domain must be long enough. The convergence of the method has been verified with grid refinement. All the calculations have been performed on a PC equipped with a Pentium III processor at 550 MHz. Copyright

Infected Atopic Dermatitis Lesions Contain Pharmacologic Amounts of Lipoteichoic Acid

Science.gov (United States)

Travers, Jeffrey B.; Kozman, Amal; Mousdicas, Nico; Saha, Chandan; Landis, Megan; Al-Hassani, Mohammed; Yao, Weiguo; Yao, Yongxue; Hyatt, Ann-Marie; Sheehan, Michael P.; Haggstrom, Anita N.; Kaplan, Mark H.

2009-01-01

Background Bacterial infection with Staphylococcus aureus is a known trigger for worsening of atopic dermatitis (AD); the exact mechanisms by which bacterial infection worsens dermatitis are unknown. Objective We sought to characterize the amounts of the biologically active bacterial lipoprotein lipoteichoic acid (LTA) in infected AD lesions. Methods Eighty-nine children with clinically impetiginized lesions of AD were enrolled in this study. A lesion was graded clinically using the Eczema Area and Severity Index (EASI), and then wash fluid obtained from the lesion for quantitative bacterial culture, and measurement of LTA and cytokines. The staphylococcal isolate was tested for antibiotic susceptibilities. The patients were treated with a regimen that included topical corticosteroids and systemic antibiotics and the lesion was re-analyzed after two weeks. Results S. aureus was identified in 79 of 89 children enrolled in the study. The bacterial CFU correlated with the EASI lesional score (p = 0.04). LTA levels up to 9.8 μg/ml were measured in the wash fluid samples and the amounts correlated with the lesional EASI scores (p = 0.01) and S. aureus CFU (p < 0.001). Approximately 30% of clinically impetiginized AD lesions contained greater than 1 μg/ml LTA, amounts that exert effects on various cell types in vitro. Moreover, injection of skin tissue ex vivo with amounts of LTA found in AD lesions resulted in epidermal cytokine gene expression. Conclusions Pharmacologic levels of LTA are found in many infected atopic dermatitis lesions. Clinical Implications These findings suggest that staphylococcal LTA could be an important mediator of the increased skin inflammation associated with infected AD. Capsule Summary These studies demonstrate high levels of staphylococcal LTA are found on impetiginized AD lesions. Moreover, subjects harboring MRSA exhibited greater total body involvement of AD. PMID:19962742

Simple Bone Cyst of Metacarpal: Rare Lesion with Unique Treatment

Science.gov (United States)

Patwardhan, Sandeep; Shah, Kunal; Shyam, Ashok; Sancheti, Parag

2014-01-01

Introduction: Simple bone cyst or unicameral bone cyst (UBC) are benign cystic lesions commonly found in femur and humerus. However hand is a very rare site of occurrence. Treatment described for UBC of hand commonly involves curettage and bone grafting. Case Report: A 7 year old right hand dominant girl presented to us with chief complaints of pain and swelling in right 4th metacarpal since 2 month. On imaging, plain radiographs of right hand showed expansile lytic lesion on Metaphyseal-diaphyseal region of 4th metacarpal with pathological fracture. MRI showed cystic lesions with internal loculations and fluid-fluid levels (Fig 2). There was minimal soft tissue extension. We performed aspiration which showed serosanguinous fluid with haemorrhagic tinge. With the diagnosis of unicameral bone cyst in mind we performed and closed intramedullary nail with k wire. The cyst healed up completely within 2 months. There was no recurrence at 18 month follow up. Conclusion: In conclusion simple bone cyst is very rare in metacarpal bone. However it should be considered as important differential since it warrants simple treatment and extensive procedures should be avoided. PMID:27298987

Thalamic lesions in multiple sclerosis by 7T MRI: Clinical implications and relationship to cortical pathology.

Science.gov (United States)

Harrison, Daniel M; Oh, Jiwon; Roy, Snehashis; Wood, Emily T; Whetstone, Anna; Seigo, Michaela A; Jones, Craig K; Pham, Dzung; van Zijl, Peter; Reich, Daniel S; Calabresi, Peter A

2015-08-01

Pathology in both cortex and deep gray matter contribute to disability in multiple sclerosis (MS). We used the increased signal-to-noise ratio of 7-tesla (7T) MRI to visualize small lesions within the thalamus and to relate this to clinical information and cortical lesions. We obtained 7T MRI scans on 34 MS cases and 15 healthy volunteers. Thalamic lesion number and volume were related to demographic data, clinical disability measures, and lesions in cortical gray matter. Thalamic lesions were found in 24/34 of MS cases. Two lesion subtypes were noted: discrete, ovoid lesions, and more diffuse lesional areas lining the periventricular surface. The number of thalamic lesions was greater in progressive MS compared to relapsing-remitting (mean ±SD, 10.7 ±0.7 vs. 3.0 ±0.7, respectively, p < 0.001). Thalamic lesion burden (count and volume) correlated with EDSS score and measures of cortical lesion burden, but not with white matter lesion burden or white matter volume. Using 7T MRI allows identification of thalamic lesions in MS, which are associated with disability, progressive disease, and cortical lesions. Thalamic lesion analysis may be a simpler, more rapid estimate of overall gray matter lesion burden in MS. © The Author(s), 2015.

Application of volume of fluid method for simulation of a droplet impacting a fiber

Directory of Open Access Journals (Sweden)

M. Khalili

2016-06-01

Full Text Available In the present work, impact of a Newtonian drop on horizontal thin fibers with circular cross section is simulated in 2D views. The numerical simulations of the phenomena are carried out using volume of fluid (VOF method for tracking the free surface motion. Impacting of a Newtonian droplet on a circular thin fiber (350μm radius investigated numerically. The main focus of this simulation is to acquire threshold radius and velocity of a drop which is entirely captured by the fiber. The model agrees well with the experiments and demonstrates the threshold radius decreased generally with the increase of impact velocity. In other words, for velocity larger than threshold velocity of capture perhaps only a small portion of fluid is stuck on the solid and the rest of the drop is ejected for impact velocity smaller than critical velocity the drop is totally captured. This threshold velocity has been determined when the impact is centered.

Indian Hedgehog in Synovial Fluid Is a Novel Marker for Early Cartilage Lesions in Human Knee Joint

Directory of Open Access Journals (Sweden)

Congming Zhang

2014-04-01

Full Text Available To determine whether there is a correlation between the concentration of Indian hedgehog (Ihh in synovial fluid (SF and the severity of cartilage damage in the human knee joints, the knee cartilages from patients were classified using the Outer-bridge scoring system and graded using the Modified Mankin score. Expression of Ihh in cartilage and SF samples were analyzed with immunohistochemistry (IHC, western blot, and enzyme-linked immunosorbent assay (ELISA. Furthermore, we detected and compared Ihh protein levels in rat and mice cartilages between normal control and surgery-induced osteoarthritis (OA group by IHC and fluorescence molecular tomography in vivo respectively. Ihh expression was increased 5.2-fold in OA cartilage, 3.1-fold in relative normal OA cartilage, and 1.71-fold in OA SF compared to normal control samples. The concentrations of Ihh in cartilage and SF samples was significantly increased in early-stage OA samples when compared to normal samples (r = 0.556; p < 0.001; however, there were no significant differences between normal samples and late-stage OA samples. Up-regulation of Ihh protein was also an early event in the surgery-induced OA models. Increased Ihh is associated with the severity of OA cartilage damage. Elevated Ihh content in human knee joint synovial fluid correlates with early cartilage lesions.

Goal-directed fluid optimization based on stroke volume variation and cardiac index during one-lung ventilation in patients undergoing thoracoscopy lobectomy operations: a pilot study

Directory of Open Access Journals (Sweden)

Jian Zhang

2013-07-01

Full Text Available OBJECTIVES: This pilot study was designed to utilize stroke volume variation and cardiac index to ensure fluid optimization during one-lung ventilation in patients undergoing thoracoscopic lobectomies. METHODS: Eighty patients undergoing thoracoscopic lobectomy were randomized into either a goal-directed therapy group or a control group. In the goal-directed therapy group, the stroke volume variation was controlled at 10%±1%, and the cardiac index was controlled at a minimum of 2.5 L.min-1.m-2. In the control group, the MAP was maintained at between 65 mm Hg and 90 mm Hg, heart rate was maintained at between 60 BPM and 100 BPM, and urinary output was greater than 0.5 mL/kg-1/h-1. The hemodynamic variables, arterial blood gas analyses, total administered fluid volume and side effects were recorded. RESULTS: The PaO2/FiO2-ratio before the end of one-lung ventilation in the goal-directed therapy group was significantly higher than that of the control group, but there were no differences between the goal-directed therapy group and the control group for the PaO2/FiO2-ratio or other arterial blood gas analysis indices prior to anesthesia. The extubation time was significantly earlier in the goal-directed therapy group, but there was no difference in the length of hospital stay. Patients in the control group had greater urine volumes, and they were given greater colloid and overall fluid volumes. Nausea and vomiting were significantly reduced in the goal-directed therapy group. CONCLUSION: The results of this study demonstrated that an optimization protocol, based on stroke volume variation and cardiac index obtained with a FloTrac/Vigileo device, increased the PaO2/FiO2-ratio and reduced the overall fluid volume, intubation time and postoperative complications (nausea and vomiting in thoracic surgery patients requiring one-lung ventilation.

A prospective study of endoscopic ultrasonography features, cyst fluid carcinoembryonic antigen, and fluid cytology for the differentiation of small pancreatic cystic neoplasms.

Science.gov (United States)

Wang, Ying; Chai, Ningli; Feng, Jia; Linghu, Enqiang

2017-08-24

With improvements in imaging technologies, pancreatic cystic lesions (PCLs) have been increasingly identified in recent years. However, the imaging modalities used to differentiate the categories of pancreatic cysts remain limited, which may cause confusion when planning treatment. Due to progress in endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) technology, auxiliary diagnosis by the detection of cystic fluid has become a recent trend. From March 2015 to April 2016, 120 patients with PCLs were enrolled in this study. According to the results of EUS, cyst fluid carcinoembryonic antigen (CEA) analysis, and cystic fluid cytology, the patients were divided into two groups: a nonmucinous and a mucinous group. Of those, 61 patients who had undergone surgical resection were included in the analysis. The clinical features, biochemical and tumor markers of cyst fluid as well as the cytological test results of the patients were compared with histopathology results. A cyst size of 4.0 cm was used as the boundary value; a cyst ≤4.0 cm was defined as a small PCL. 87 (72.5%) lesions were ≤4.0 cm, and 33 (27.5%) lesions were >4.0 cm. Regarding the analysis of CEA and carbohydrate antigens 19-9 (CA19-9), significant differences were found between the nonmucinous and mucinous groups (P < 0.05) according to nonparametric independent samples tests. The EUS, cystic fluid CEA, and cystic fluid cytology results were compared with the tissue pathology findings using McNemar's test (P < 0.05) and showed a sensitivity of 90% and a specificity of 84%. A diagnostic combination of EUS, cyst fluid CEA, and cystic fluid cytology could be used to differentiate small pancreatic cystic neoplasms. Cystic fluid cytology analysis is helpful for planning treatment for pancreatic cystic tumors that pose a surgical risk.

A two-phase debris-flow model that includes coupled evolution of volume fractions, granular dilatancy, and pore-fluid pressure

Science.gov (United States)

George, David L.; Iverson, Richard M.

2011-01-01

Pore-fluid pressure plays a crucial role in debris flows because it counteracts normal stresses at grain contacts and thereby reduces intergranular friction. Pore-pressure feedback accompanying debris deformation is particularly important during the onset of debrisflow motion, when it can dramatically influence the balance of forces governing downslope acceleration. We consider further effects of this feedback by formulating a new, depth-averaged mathematical model that simulates coupled evolution of granular dilatancy, solid and fluid volume fractions, pore-fluid pressure, and flow depth and velocity during all stages of debris-flow motion. To illustrate implications of the model, we use a finite-volume method to compute one-dimensional motion of a debris flow descending a rigid, uniformly inclined slope, and we compare model predictions with data obtained in large-scale experiments at the USGS debris-flow flume. Predictions for the first 1 s of motion show that increasing pore pressures (due to debris contraction) cause liquefaction that enhances flow acceleration. As acceleration continues, however, debris dilation causes dissipation of pore pressures, and this dissipation helps stabilize debris-flow motion. Our numerical predictions of this process match experimental data reasonably well, but predictions might be improved by accounting for the effects of grain-size segregation.

Fast semi-automated lesion demarcation in stroke

Directory of Open Access Journals (Sweden)

Bianca de Haan

2015-01-01

Full Text Available Lesion–behaviour mapping analyses require the demarcation of the brain lesion on each (usually transverse slice of the individual stroke patient's brain image. To date, this is generally thought to be most precise when done manually, which is, however, both time-consuming and potentially observer-dependent. Fully automated lesion demarcation methods have been developed to address these issues, but these are often not practicable in acute stroke research where for each patient only a single image modality is available and the available image modality differs over patients. In the current study, we evaluated a semi-automated lesion demarcation approach, the so-called Clusterize algorithm, in acute stroke patients scanned in a range of common image modalities. Our results suggest that, compared to the standard of manual lesion demarcation, the semi-automated Clusterize algorithm is capable of significantly speeding up lesion demarcation in the most commonly used image modalities, without loss of either lesion demarcation precision or lesion demarcation reproducibility. For the three investigated acute datasets (CT, DWI, T2FLAIR, containing a total of 44 patient images obtained in a regular clinical setting at patient admission, the reduction in processing time was on average 17.8 min per patient and this advantage increased with increasing lesion volume (up to 60 min per patient for the largest lesion volumes in our datasets. Additionally, our results suggest that performance of the Clusterize algorithm in a chronic dataset with 11 T1 images was comparable to its performance in the acute datasets. We thus advocate the use of the Clusterize algorithm, integrated into a simple, freely available SPM toolbox, for the precise, reliable and fast preparation of imaging data for lesion–behaviour mapping analyses.

An energy stable evolution method for simulating two-phase equilibria of multi-component fluids at constant moles, volume and temperature

KAUST Repository

Kou, Jisheng; Sun, Shuyu; Wang, Xiuhua

2016-01-01

In this paper, we propose an energy-stable evolution method for the calculation of the phase equilibria under given volume, temperature, and moles (VT-flash). An evolution model for describing the dynamics of two-phase fluid system is based on Fick

T2 black lesions on routine knee MRI: differential considerations

International Nuclear Information System (INIS)

Wadhwa, Vibhor; Cho, Gina; Moore, Daniel; Pezeshk, Parham; Coyner, Katherine; Chhabra, Avneesh

2016-01-01

The majority of abnormal findings or lesions on T2-weighted fast spin-echo (FSE) magnetic resonance imaging (MRI) are hyperintense due to increased perfusion or fluid content, such as infections, tumours or synovitis. Hypointense lesions on T2-weighted images (both fat-suppressed and non-fat-suppressed) are less common and can sometimes be overlooked. Such lesions have limited differential diagnostic possibilities, and include vacuum phenomenon, loose body, tenosynovial giant cell tumour, rheumatoid arthritis, haemochromatosis, gout, amyloid, chondrocalcinosis, hydroxyapetite deposition disease, lipoma arborescens, arthrofibrosis and iatrogenic lesions. These lesions often show characteristic appearances and predilections in the knee. In this article, the authors describe the MRI features of hypointense T2 lesions on routine knee MRI and outline a systematic diagnostic approach towards their evaluation. (orig.)

Lesion dehydration rate changes with the surface layer thickness during enamel remineralization

Science.gov (United States)

Chang, Nai-Yuan N.; Jew, Jamison M.; Fried, Daniel

2018-02-01

A transparent highly mineralized outer surface zone is formed on caries lesions during remineralization that reduces the permeability to water and plaque generated acids. However, it has not been established how thick the surface zone should be to inhibit the penetration of these fluids. Near-IR (NIR) reflectance coupled with dehydration can be used to measure changes in the fluid permeability of lesions in enamel and dentin. Based on our previous studies, we postulate that there is a strong correlation between the surface layer thickness and the rate of dehydration. In this study, the rates of dehydration for simulated lesions in enamel with varying remineralization durations were measured. Reflectance imaging at NIR wavelengths from 1400-2300 nm, which coincides with higher water absorption and manifests the greatest sensitivity to contrast changes during dehydration measurements, was used to image simulated enamel lesions. The results suggest that the relationship between surface zone thickness and lesion permeability is highly non-linear, and that a small increase in the surface layer thickness may lead to a significant decrease in permeability.

Application of volume-weighted skew-upwind differencing to thermal and fluid mixing in the cold leg and downcomer of a PWR

International Nuclear Information System (INIS)

Chen, F.F.; Miao, C.C.; Chen, B.C.J.; Domanus, H.M.; Lyczkowski, R.W.; Sha, W.T.

1983-01-01

Upwind differencing has been the most common numerical scheme used in computational fluid flow and heat transfer in past years. However, the numerical diffusion induced by the use of upwind differencing can be significant in problems involving thermal mixing. Thermal and fluid mixing in a pressurized water reactor during high pressurized coolant injection is a typical example where numerical diffusion is significant. An improved volume-weighted skew-upwind differencing is used here to reduce numerical diffusion without overshooting or undershooting which is the major defect of original skew-upwind differencing proposed by Raithby. The basic concept of volume-weighted skew-upwind differencing is shown. Computations were performed using COMMIX-1B, an extended version of the COMMIX-1A. The experiment analyzed here is test No. 1 of the SAI experiment

Small Lesion Size Is Associated with Sleep-Related Epilepsy in Focal Cortical Dysplasia Type II

Directory of Open Access Journals (Sweden)

Bo Jin

2018-02-01

Full Text Available ObjectiveTo investigate the neuroimaging and clinical features associated with sleep-related epilepsy (SRE in patients with focal cortical dysplasia (FCD type II.MethodsPatients with histopathologically proven FCD type II were included from three epilepsy centers. SRE was defined according to the video EEG findings and seizure history. Cortical surface reconstruction and volume calculation were performed using FreeSurfer. The lesions were manually delineated on T1 volumetric MRI using the ITK-SNAP software. The lesion volumes were normalized by the intracranial volume of each patient. The lesions were classified as small or large by placing a threshold based on quantitative (whether the lesion was detected on MRI report and qualitative (volume criteria.ResultsA total of 77 consecutive patients were included. Of them, 36 had SRE and 41 had non-SRE. An earlier age of epilepsy onset, high seizure frequency, regional interictal EEG findings, and favorable surgical outcome were characteristic in both groups. Small lesions were defined as those having a volume <3,217 mm3. In total, 60.9% of the patients with SRE (25/41 had small FCD lesion, which was significantly higher than the non-SRE group (9/34, 26.5%, p = 0.005. Small lesion size was the only predictor significantly associated with SRE in the overall type II group by multivariate analyses (p = 0.016. Although the proportion of patients who had frontal FCD and SRE was higher than non-frontal FCD (54.5 vs. 27.3%, p = 0.043, the relationship between SRE and lesion location was not confirmed by multivariate analysis. Thalamic volume and seizure semiology were not statistically different between the SRE and non-SRE group. The significant association between lesion size and SRE was reproducible in type IIb and IIa subgroups.SignificanceSRE is common in patients with FCD type II. Small FCD type II lesions are significantly associated with SRE. Although our findings cannot be applied to

Computational fluid dynamics study of viscous fingering in supercritical fluid chromatography.

Science.gov (United States)

Subraveti, Sai Gokul; Nikrityuk, Petr; Rajendran, Arvind

2018-01-26

Axi-symmetric numerical simulations are carried out to study the dynamics of a plug introduced through a mixed-stream injection in supercritical fluid chromatographic columns. The computational fluid dynamics model developed in this work takes into account both the hydrodynamics and adsorption equilibria to describe the phenomena of viscous fingering and plug effect that contribute to peak distortions in mixed-stream injections. The model was implemented into commercial computational fluid dynamics software using user-defined functions. The simulations describe the propagation of both the solute and modifier highlighting the interplay between the hydrodynamics and plug effect. The simulated peaks showed good agreement with experimental data published in the literature involving different injection volumes (5 μL, 50 μL, 1 mL and 2 mL) of flurbiprofen on Chiralpak AD-H column using a mobile phase of CO 2 and methanol. The study demonstrates that while viscous fingering is the main source of peak distortions for large-volume injections (1 mL and 2 mL) it has negligible impact on small-volume injections (5 μL and 50 μL). Band broadening in small-volume injections arise mainly due to the plug effect. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

The effect of the volume fraction and viscosity on the compression and tension behavior of the cobalt-ferrite magneto-rheological fluids

Directory of Open Access Journals (Sweden)

H. Shokrollahi

2016-03-01

Full Text Available The purpose of this work is to investigate the effects of the volume fraction and bimodal distribution of solid particles on the compression and tension behavior of the Co-ferrite-based magneto-rheological fluids (MRFs containing silicon oil as a carrier. Hence, Co-ferrite particles (CoFe2O4 with two various sizes were synthesized by the chemical co-precipitation method and mixed so as to prepare the bimodal MRF. The X-Ray Diffraction (XRD analysis, Fourier Transform Infrared Spectroscopy (FTIR, Laser Particle Size Analysis (LPSA and Vibrating Sample Magnetometer (VSM were conducted to examine the structural and magnetic properties, respectively. The results indicated that the increase of the volume fraction has a direct increasing influence on the values of the compression and tension strengths of fluids. In addition, the compression and tension strengths of the mixed MRF sample (1.274 and 0.647 MPa containing 60 and 550 nm samples were higher than those of the MRF sample with the same volume fraction and uniform particle size of 550 nm.

Improved differentiation between MS and vascular brain lesions using FLAIR* at 7 Tesla

Energy Technology Data Exchange (ETDEWEB)

Kilsdonk, Iris D.; Wattjes, Mike P.; Lopez-Soriano, Alexandra; Jong, Marcus C. de; Graaf, Wolter L. de; Conijn, Mandy M.A.; Barkhof, Frederik [VU University Medical Center, Department of Radiology, De Boelelaan 1118, HZ, Amsterdam (Netherlands); Kuijer, Joost P.A. [VU University Medical Center, Department of Physics and Medical Technology, Amsterdam (Netherlands); Polman, Chris H. [VU University Medical Center, Department of Neurology, Amsterdam (Netherlands); Luijten, Peter R. [University Medical Center, Department of Radiology, Utrecht (Netherlands); Geurts, Jeroen J.G. [VU University, Department of Anatomy and Neurosciences, Amsterdam (Netherlands); Geerlings, Mirjam I. [University Medical Center, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands)

2014-04-15

To investigate whether a new magnetic resonance image (MRI) technique called T2*-weighted fluid attenuation inversion recovery (FLAIR*) can differentiate between multiple sclerosis (MS) and vascular brain lesions, at 7 Tesla (T). We examined 16 MS patients and 16 age-matched patients with (risk factors for) vascular disease. 3D-FLAIR and T2*-weighted images were combined into FLAIR* images. Lesion type and intensity, perivascular orientation and presence of a hypointense rim were analysed. In total, 433 cerebral lesions were detected in MS patients versus 86 lesions in vascular patients. Lesions in MS patients were significantly more often orientated in a perivascular manner: 74 % vs. 47 % (P < 0.001). Ten MS lesions (2.3 %) were surrounded by a hypointense rim on FLAIR*, and 24 MS lesions (5.5 %) were hypointense on T2*. No lesions in vascular patients showed any rim or hypointensity. Specificity of differentiating MS from vascular lesions on 7-T FLAIR* increased when the presence of a central vessel was taken into account (from 63 % to 88 %), most obviously for deep white matter lesions (from 69 % to 94 %). High sensitivity remained (81 %). 7-T FLAIR* improves differentiation between MS and vascular lesions based on lesion location, perivascular orientation and presence of hypointense (rims around) lesions. circle A new MRI technique T2*-weighted fluid attenuation inversion recovery (FLAIR*) was investigated. circle FLAIR* at 7-T MRI combines FLAIR and T2* images into a single image. circle FLAIR* at 7 T does not require enhancement with contrast agents. (orig.)

3D mapping of cerebrospinal fluid local volume changes in patients with hydrocephalus treated by surgery: preliminary study

International Nuclear Information System (INIS)

Hodel, Jerome; Besson, Pierre; Pruvo, Jean-Pierre; Leclerc, Xavier; Rahmouni, Alain; Grandjacques, Benedicte; Luciani, Alain; Petit, Eric; Lebret, Alain; Outteryck, Olivier; Benadjaoud, Mohamed Amine; Maraval, Anne; Decq, Philippe

2014-01-01

To develop automated deformation modelling for the assessment of cerebrospinal fluid (CSF) local volume changes in patients with hydrocephalus treated by surgery. Ventricular and subarachnoid CSF volume changes were mapped by calculating the Jacobian determinant of the deformation fields obtained after non-linear registration of pre- and postoperative images. A total of 31 consecutive patients, 15 with communicating hydrocephalus (CH) and 16 with non-communicating hydrocephalus (NCH), were investigated before and after surgery using a 3D SPACE (sampling perfection with application optimised contrast using different flip-angle evolution) sequence. Two readers assessed CSF volume changes using 3D colour-encoded maps. The Evans index and postoperative volume changes of the lateral ventricles and sylvian fissures were quantified and statistically compared. Before surgery, sylvian fissure and brain ventricle volume differed significantly between CH and NCH (P = 0.001 and P = 0.025, respectively). After surgery, 3D colour-encoded maps allowed for the visual recognition of the CSF volume changes in all patients. The amounts of ventricle volume loss of CH and NCH patients were not significantly different (P = 0.30), whereas readjustment of the sylvian fissure volume was conflicting in CH and NCH patients (P < 0.001). The Evans index correlated with ventricle volume in NCH patients. 3D mapping of CSF volume changes is feasible providing a quantitative follow-up of patients with hydrocephalus. (orig.)

3D mapping of cerebrospinal fluid local volume changes in patients with hydrocephalus treated by surgery: preliminary study

Energy Technology Data Exchange (ETDEWEB)

Hodel, Jerome [Hopital Roger Salengro, Department of Neuroradiology, Lille (France); Hopital Roger Salengro, Service de Neuroradiologie, Lille (France); Besson, Pierre; Pruvo, Jean-Pierre; Leclerc, Xavier [Hopital Roger Salengro, Department of Neuroradiology, Lille (France); Rahmouni, Alain; Grandjacques, Benedicte; Luciani, Alain [Hopital Henri Mondor, Department of Radiology, Creteil (France); Petit, Eric; Lebret, Alain [Signals Images and Intelligent Systems Laboratory, Creteil (France); Outteryck, Olivier [Hopital Roger Salengro, Department of Neurology, Lille (France); Benadjaoud, Mohamed Amine [Radiation Epidemiology Team, CESP, Centre for Research in Epidemiology and Population Health U1018, Villejuif (France); Maraval, Anne [Hopital Henri Mondor, Department of Neuroradiology, Creteil (France); Decq, Philippe [Hopital Henri Mondor, Department of Neurosurgery, Creteil (France)

2014-01-15

To develop automated deformation modelling for the assessment of cerebrospinal fluid (CSF) local volume changes in patients with hydrocephalus treated by surgery. Ventricular and subarachnoid CSF volume changes were mapped by calculating the Jacobian determinant of the deformation fields obtained after non-linear registration of pre- and postoperative images. A total of 31 consecutive patients, 15 with communicating hydrocephalus (CH) and 16 with non-communicating hydrocephalus (NCH), were investigated before and after surgery using a 3D SPACE (sampling perfection with application optimised contrast using different flip-angle evolution) sequence. Two readers assessed CSF volume changes using 3D colour-encoded maps. The Evans index and postoperative volume changes of the lateral ventricles and sylvian fissures were quantified and statistically compared. Before surgery, sylvian fissure and brain ventricle volume differed significantly between CH and NCH (P = 0.001 and P = 0.025, respectively). After surgery, 3D colour-encoded maps allowed for the visual recognition of the CSF volume changes in all patients. The amounts of ventricle volume loss of CH and NCH patients were not significantly different (P = 0.30), whereas readjustment of the sylvian fissure volume was conflicting in CH and NCH patients (P < 0.001). The Evans index correlated with ventricle volume in NCH patients. 3D mapping of CSF volume changes is feasible providing a quantitative follow-up of patients with hydrocephalus. (orig.)

Regulation of extracellular fluid volume and renal function

DEFF Research Database (Denmark)

Henriksen, Jens Henrik Sahl

2011-01-01

Normal fluid homoeostasis includes dynamic shifts in water, crystalloids, and proteins between the various compartments of the body (1–3). The fluid dynamics are controlled by refined mechanisms that include water and solute intake, renal handling, haemodynamic/oncotic forces, and neurohumoral...

Fluid dynamics transactions

CERN Document Server

Fiszdon, W

1965-01-01

Fluid Dynamics Transactions, Volume 2 compiles 46 papers on fluid dynamics, a subdiscipline of fluid mechanics that deals with fluid flow. The topics discussed in this book include developments in interference theory for aeronautical applications; diffusion from sources in a turbulent boundary layer; unsteady motion of a finite wing span in a compressible medium; and wall pressure covariance and comparison with experiment. The certain classes of non-stationary axially symmetric flows in magneto-gas-dynamics; description of the phenomenon of secondary flows in curved channels by means of co

Numerical Cerebrospinal System Modeling in Fluid-Structure Interaction.

Science.gov (United States)

Garnotel, Simon; Salmon, Stéphanie; Balédent, Olivier

2018-01-01

Cerebrospinal fluid (CSF) stroke volume in the aqueduct is widely used to evaluate CSF dynamics disorders. In a healthy population, aqueduct stroke volume represents around 10% of the spinal stroke volume while intracranial subarachnoid space stroke volume represents 90%. The amplitude of the CSF oscillations through the different compartments of the cerebrospinal system is a function of the geometry and the compliances of each compartment, but we suspect that it could also be impacted be the cardiac cycle frequency. To study this CSF distribution, we have developed a numerical model of the cerebrospinal system taking into account cerebral ventricles, intracranial subarachnoid spaces, spinal canal and brain tissue in fluid-structure interactions. A numerical fluid-structure interaction model is implemented using a finite-element method library to model the cerebrospinal system and its interaction with the brain based on fluid mechanics equations and linear elasticity equations coupled in a monolithic formulation. The model geometry, simplified in a first approach, is designed in accordance with realistic volume ratios of the different compartments: a thin tube is used to mimic the high flow resistance of the aqueduct. CSF velocity and pressure and brain displacements are obtained as simulation results, and CSF flow and stroke volume are calculated from these results. Simulation results show a significant variability of aqueduct stroke volume and intracranial subarachnoid space stroke volume in the physiological range of cardiac frequencies. Fluid-structure interactions are numerous in the cerebrospinal system and difficult to understand in the rigid skull. The presented model highlights significant variations of stroke volumes under cardiac frequency variations only.

Lower vs. higher fluid volumes in sepsis-protocol for a systematic review with meta-analysis

DEFF Research Database (Denmark)

Meyhoff, T S; Møller, M H; Hjortrup, P B

2017-01-01

sequential analysis of randomised clinical trials comparing different strategies to obtain separation in fluid volumes or balances during resuscitation of adult patients with sepsis. We will systematically search the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, BIOSIS and Epistemonikos...... for relevant literature. We will follow the recommendations by the Cochrane Collaboration and the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. The risk of systematic errors (bias) and random errors will be assessed, and the overall quality of evidence will be evaluated...

A numerical investigation of the functionality of coronary bifurcation lesions with respect to lesion configuration and stenosis severity.

Science.gov (United States)

Pagiatakis, Catherine; Tardif, Jean-Claude; L'Allier, Philippe L; Mongrain, Rosaire

2015-09-18

The intervention of coronary bifurcation lesions is associated with higher rates of peri- and post-procedural clinical events compared to the treatment of isolated lesions. Overall, the factors that influence the dynamics of these types of configurations are still not well understood. A geometric multiscale model, consisting of a 3D representation of the left main coronary artery bifurcation and a 0D representation of the rest of the cardiovascular system, was developed. Computational fluid dynamics simulations of the 3D domain were executed by implementing the multiscale algorithm, in order to characterize the functionality of different multilesional configurations as a function of stenosis severity. The investigation found that coronary branch steal has a significant impact on the functionality of the disease and can render a two-lesion configuration more severe compared to a three-lesion configuration. As a result of the complexity of this phenomenon, it was also suggested that certain lesion configurations could result in false negatives in diagnosis when employing a pullback pressure recording across the tandem lesions. In conclusion, this study showed that coronary bifurcation lesions are subject to intricate haemodynamic interactions which render the characterization of their functionality complex and could have significant clinical implications with regards to their diagnosis and prognosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Revised Starling equation and the glycocalyx model of transvascular fluid exchange: an improved paradigm for prescribing intravenous fluid therapy.

Science.gov (United States)

Woodcock, T E; Woodcock, T M

2012-03-01

I.V. fluid therapy does not result in the extracellular volume distribution expected from Starling's original model of semi-permeable capillaries subject to hydrostatic and oncotic pressure gradients within the extracellular fluid. Fluid therapy to support the circulation relies on applying a physiological paradigm that better explains clinical and research observations. The revised Starling equation based on recent research considers the contributions of the endothelial glycocalyx layer (EGL), the endothelial basement membrane, and the extracellular matrix. The characteristics of capillaries in various tissues are reviewed and some clinical corollaries considered. The oncotic pressure difference across the EGL opposes, but does not reverse, the filtration rate (the 'no absorption' rule) and is an important feature of the revised paradigm and highlights the limitations of attempting to prevent or treat oedema by transfusing colloids. Filtered fluid returns to the circulation as lymph. The EGL excludes larger molecules and occupies a substantial volume of the intravascular space and therefore requires a new interpretation of dilution studies of blood volume and the speculation that protection or restoration of the EGL might be an important therapeutic goal. An explanation for the phenomenon of context sensitivity of fluid volume kinetics is offered, and the proposal that crystalloid resuscitation from low capillary pressures is rational. Any potential advantage of plasma or plasma substitutes over crystalloids for volume expansion only manifests itself at higher capillary pressures.

Theoretical investigation of the extinction coefficient of magnetic fluid

Energy Technology Data Exchange (ETDEWEB)

Fang Xiaopeng; Xuan Yimin, E-mail: ymxuan@mail.njust.edu.cn; Li Qiang [Nanjing University of Science and Technology, School of Energy and Power Engineering (China)

2013-05-15

A new theoretical approach for calculating the extinction coefficient of magnetic fluid is proposed, which is based on molecular dynamics (MD) simulation and T-matrix method. By means of this approach, the influence of particle diameter, particle volume fraction, and external magnetic filed on the extinction coefficient of magnetic fluid is investigated. The results show that the extinction coefficient of the magnetic fluid linearly increases with increase in the particle volume fraction. For a given particle volume fraction, the extinction coefficient increases with increase in the particle diameter which varies from 5 to 20 nm. When a uniform external magnetic filed is applied to the magnetic fluid, the extinction coefficient of the magnetic fluid presents an anisotropic feature. These results agree well with the reported experimental results. The proposed approach is applicable to investigating the optical properties of magnetic fluids.

Ureteritis cystica: A rare benign lesion

Directory of Open Access Journals (Sweden)

F. Ibrahim

2014-09-01

Full Text Available Ureteritis cystica is an uncommon benign pathology of the ureter. The etiology is unclear but the diagnosis has become much easier to make with the routine use of ureteroscopy for diagnosis of ureteric lesions. We present a case of a 63 year old Sudanese woman with a history of repeated attacks of right loin pain in whom magnetic resonance urography (MRU showed multiple filling defects in the right ureter. These were initially thought to be malignant urothelial lesions. Ureteroscopy revealed cystic smooth walled masses which discharged tiny turbid fluid on biopsy. An intraoperative diagnosis of ureteritis cystica was confirmed. The patient was managed conservatively.

Computed tomographic localization of Rt. Juxtadiaphragmatic lesions

International Nuclear Information System (INIS)

Lee, Jong Doo; Choe, Kyu Ok; Kim, Ki Whang; Hong, In Soo

1989-01-01

Since several reports were published about CT differentiation of peridiaphragmatic fluid collection using 4 useful signs-diaphragm, displaced crus, bare area and interface signs. Transverse CT scans of 20 patients with abnormal diaphragmatic position due to large intrathoracic or intraabdominal lesion were analysed on the basis of those signs. Difficulties were encounted with differentiation when laterally located lesions did not extend to as far medially as crus, and when diaphragmatic stripe could not be distinguished from thickened pleura or adjacent wall of lesions. As a result, limited cases can be adequately assessed by diaphragm or displaced crus sign. Furthermore, bare area and interface signs seemed to be not useful at all. However relationship between caudal tip of lesions and thoracoabdominal wall was always constant in each thoracic or abdominal lesions. All of intrathoracic masses or empyemas were attached to thoracic wall displacing properitoneal and perirenal fat medially or inferiorly. By contraries, all of intraabdominal masses were separated from abdominal wall displacing properitoneal fat or peritoneum laterally. The key to accurate localization seemed to be identification of such relationship

Cerebrospinal fluid volume measurements in hydrocephalic rats.

Science.gov (United States)

Basati, Sukhraaj; Desai, Bhargav; Alaraj, Ali; Charbel, Fady; Linninger, Andreas

2012-10-01

Object Experimental data about the evolution of intracranial volume and pressure in cases of hydrocephalus are limited due to the lack of available monitoring techniques. In this study, the authors validate intracranial CSF volume measurements within the lateral ventricle, while simultaneously using impedance sensors and pressure transducers in hydrocephalic animals. Methods A volume sensor was fabricated and connected to a catheter that was used as a shunt to withdraw CSF. In vitro bench-top calibration experiments were created to provide data for the animal experiments and to validate the sensors. To validate the measurement technique in a physiological system, hydrocephalus was induced in weanling rats by kaolin injection into the cisterna magna. At 28 days after induction, the sensor was implanted into the lateral ventricles. After sealing the skull using dental cement, an acute CSF drainage/infusion protocol consisting of 4 sequential phases was performed with a pump. Implant location was confirmed via radiography using intraventricular iohexol contrast administration. Results Controlled CSF shunting in vivo with hydrocephalic rats resulted in precise and accurate sensor measurements (r = 0.98). Shunting resulted in a 17.3% maximum measurement error between measured volume and actual volume as assessed by a Bland-Altman plot. A secondary outcome confirmed that both ventricular volume and intracranial pressure decreased during CSF shunting and increased during infusion. Ventricular enlargement consistent with successful hydrocephalus induction was confirmed using imaging, as well as postmortem. These results indicate that volume monitoring is feasible for clinical cases of hydrocephalus. Conclusions This work marks a departure from traditional shunting systems currently used to treat hydrocephalus. The overall clinical application is to provide alternative monitoring and treatment options for patients. Future work includes development and testing of a chronic

Extrapleural Inner Thoracic Wall Lesions: Multidetector CT Findings

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Soo; Kim, Young Tong; Jou, Sung Shik [Soonchunhyang University, Cheonan Hospital, Cheonan (Korea, Republic of)

2010-06-15

The extrapleural space is external to the parietal pleura in the thorax. The structures within and adjacent to this region include the fat pad, endothoracic fascia, intercostal muscles, connective tissue, nerves, vessels, and ribs. Further, the space is divided into the inner and outer thoracic wall by the innermost intercostal muscle. Extrapleural lesions in the inner thoracic wall are classified as air-containing lesions, fat-containing lesions, and soft tissue-containing lesions according on their main component. Air-containing lesions include extrapleural air from direct chest trauma and extrapleural extension from pneumomediastinum. Prominent extrapleural fat is seen in decreased lung volume conditions, and can also be seen in normal individuals. Soft tissue-containing lesions include extrapleural extensions from a pleural or chest wall infection as well as tumors and extrapleural hematoma. We classify extrapleural lesions in the inner thoracic wall and illustrate their imaging findings

Clinical Usefulness of Ultrasonography-Guided Aspiration Cytology for Nonpalpable Breast Lesions

International Nuclear Information System (INIS)

Park, Jeong Mi; Kim, Jun Hyoung; Choi, Yong Baik; Gong, Gyung Yub

1996-01-01

To evaluate the clinical utility of the ultrasonography (US)-guided aspiration cytology for nonpalpable breast lesions. US-guided aspiration cytology was performed in 50 lesions in 37 patients who underwent US of the breasts and axillary area. Adequacy for the pathologic diagnosis was correlated with the size, volume, depth of the lesions and type of needles. The causes of inadequacy and complications were assessed. Available mammographic findings were correlated with US findings. Final diagnoses on surgical biopsy were correlated with the diagnoses on aspiration cytology. Thirty four of the 50 lesions were adequate for pathologic diagnosis (68%). The size and volume of the lesions were not significantly related with adequacy.Shallow depth was significantly better. Cutting needles were better than plain needles. Causes of inadequacy were low cell number and bleeding. Complications were small amount of bleeding and pain. Mammographic findings were nonspecific in 61% of the cases. Pathologic diagnoses were ductal hyperplasia and fibrocystic changes in 62%.Surgical biopsy was done in 5 cases. None of the lesions showed malignancy. US-guidance is necessary and effective for the cytologic diagnoses of the nonpalpable lesions. However, invasive procedure could be deferred for several months for these nonpalpable small lesions which are mostly benign

Clinical Usefulness of Ultrasonography-Guided Aspiration Cytology for Nonpalpable Breast Lesions

Energy Technology Data Exchange (ETDEWEB)

Park, Jeong Mi; Kim, Jun Hyoung; Choi, Yong Baik; Gong, Gyung Yub [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

1996-06-15

To evaluate the clinical utility of the ultrasonography (US)-guided aspiration cytology for nonpalpable breast lesions. US-guided aspiration cytology was performed in 50 lesions in 37 patients who underwent US of the breasts and axillary area. Adequacy for the pathologic diagnosis was correlated with the size, volume, depth of the lesions and type of needles. The causes of inadequacy and complications were assessed. Available mammographic findings were correlated with US findings. Final diagnoses on surgical biopsy were correlated with the diagnoses on aspiration cytology. Thirty four of the 50 lesions were adequate for pathologic diagnosis (68%). The size and volume of the lesions were not significantly related with adequacy.Shallow depth was significantly better. Cutting needles were better than plain needles. Causes of inadequacy were low cell number and bleeding. Complications were small amount of bleeding and pain. Mammographic findings were nonspecific in 61% of the cases. Pathologic diagnoses were ductal hyperplasia and fibrocystic changes in 62%.Surgical biopsy was done in 5 cases. None of the lesions showed malignancy. US-guidance is necessary and effective for the cytologic diagnoses of the nonpalpable lesions. However, invasive procedure could be deferred for several months for these nonpalpable small lesions which are mostly benign

Collagen sheet dressings for cutaneous lesions of toxic epidermal necrolysis

Directory of Open Access Journals (Sweden)

S Bhattacharya

2011-01-01

Full Text Available Toxic epidermal necrolysis (TEN is associated with a significant mortality of 30-50% and long-term sequelae. Treatment includes early admission to a burn unit, where management with precise fluid, electrolyte, protein, and energy supplementation, moderate mechanical ventilation, and expert wound care can be provided. Specific treatment with immunosuppressive drugs or immunoglobulins did not show an improved outcome in most studies and remains controversial. We have treated the cutaneous lesions of seven patients of TEN with collagen sheet dressings and have found a significant reduction in morbidity. The sheets are a one-time dressing, easy to apply and they reduce fluid loss, prevent infection, reduce pain, avoid repeated dressings and gradually peal off as the underlying lesions heal.

A mixed Fourier–Galerkin–finite-volume method to solve the fluid dynamics equations in cylindrical geometries

International Nuclear Information System (INIS)

Núñez, Jóse; Ramos, Eduardo; Lopez, Juan M

2012-01-01

We describe a hybrid method based on the combined use of the Fourier Galerkin and finite-volume techniques to solve the fluid dynamics equations in cylindrical geometries. A Fourier expansion is used in the angular direction, partially translating the problem to the Fourier space and then solving the resulting equations using a finite-volume technique. We also describe an algorithm required to solve the coupled mass and momentum conservation equations similar to a pressure-correction SIMPLE method that is adapted for the present formulation. Using the Fourier–Galerkin method for the azimuthal direction has two advantages. Firstly, it has a high-order approximation of the partial derivatives in the angular direction, and secondly, it naturally satisfies the azimuthal periodic boundary conditions. Also, using the finite-volume method in the r and z directions allows one to handle boundary conditions with discontinuities in those directions. It is important to remark that with this method, the resulting linear system of equations are band-diagonal, leading to fast and efficient solvers. The benefits of the mixed method are illustrated with example problems. (paper)

Determination of lesion size by ultrasound during radiofrequency catheter ablation.

Science.gov (United States)

Awad, S; Eick, O

2003-01-01

The catheter tip temperature that is used to control the radiofrequency generator output poorly correlates to lesion size. We, therefore, evaluated lesions created in vitro using a B-mode ultrasound imaging device as a potential means to assess lesion generation during RF applications non-invasively. Porcine ventricular tissue was immersed in saline solution at 37 degrees C. The catheter was fixed in a holder and positioned in a parallel orientation to the tissue with an array transducer (7.5 MHz) app. 3 cm above the tissue. Lesions were produced either in a temperature controlled mode with a 4-mm tip catheter with different target temperatures (50, 60, 70 and 80 degrees C, 80 W maximum output) or in a power controlled mode (25, 50 and 75 W, 20 ml/min irrigation flow) using an irrigated tip catheter. Different contact forces (0.5 N, 1.0 N) were tested, and RF was delivered for 60 s. A total of 138 lesions was produced. Out of these, 128 could be identified on the ultrasound image. The lesion depth and volume was on average 4.1 +/- 1.6 mm and 52 +/- 53 mm3 as determined by ultrasound and 3.9 +/- 1.7 mm and 52 +/- 55 mm3 as measured thereafter, respectively. A linear correlation between the lesion size determined by ultrasound and that measured thereafter was demonstrated with a correlation coefficient of r = 0.87 for lesion depth and r = 0.93 for lesion volume. We conclude that lesions can be assessed by B-mode ultrasound imaging.

Individual Assessment of Brain Tissue Changes in MS and the Effect of Focal Lesions on Short-Term Focal Atrophy Development in MS: A Voxel-Guided Morphometry Study

Directory of Open Access Journals (Sweden)

Jan Fox

2016-04-01

Full Text Available We performed voxel-guided morphometry (VGM investigating the mechanisms of brain atrophy in multiple sclerosis (MS related to focal lesions. VGM maps detect regional brain changes when comparing 2 time points on high resolution T1-weighted (T1w magnetic resonace imaging (MRI. Two T1w MR datasets from 92 relapsing-remitting MS patients obtained 12 months apart were analysed with VGM. New lesions and volume changes of focal MS lesions as well as in the surrounding tissue were identified by visual inspection on colour coded VGM maps. Lesions were dichotomized in active and inactive lesions. Active lesions, defined by either new lesions (NL (volume increase > 5% in VGM, chronic enlarging lesions (CEL (pre-existent T1w lesions with volume increase > 5%, or chronic shrinking lesions (CSL (pre-existent T1w lesions with volume reduction > 5% in VGM, were accompanied by tissue shrinkage in surrounding and/or functionally related regions. Volume loss within the corpus callosum was highly correlated with the number of lesions in its close proximity. Volume loss in the lateral geniculate nucleus was correlated with lesions along the optic radiation. VGM analysis provides strong evidence that all active lesion types (NL, CEL, and CSL contribute to brain volume reduction in the vicinity of lesions and/or in anatomically and functionally related areas of the brain.

Correlating lesion size and location to deficits after ischemic stroke: the influence of accounting for altered peri-necrotic tissue and incidental silent infarcts

Directory of Open Access Journals (Sweden)

Black Sandra E

2010-01-01

Full Text Available Abstract Background Investigators frequently quantify and evaluate the location and size of stroke lesions to help uncover cerebral anatomical correlates of deficits observed after first-ever stroke. However, it is common to discover silent infarcts such as lacunes in patients identified clinically as 'first-ever' stroke, and it is unclear if including these incidental findings may impact lesion-based investigations of brain-behaviour relationships. There is also debate concerning how to best define the boundaries of necrotic stroke lesions that blend in an ill-defined way into surrounding tissue, as it is unclear whether including this altered peri-necrotic tissue region may influence studies of brain-behaviour relationships. Therefore, for patients with clinically overt stroke, we examined whether including altered peri-necrotic tissue and incidental silent strokes influenced either lesion volume correlations with a measure of sensorimotor impairment or the anatomical localization of this impairment established using subtraction lesion analysis. Methods Chronic stroke lesions of 41 patients were manually traced from digital T1-MRI to sequentially include the: necrotic lesion core, altered peri-necrotic tissue, silent lesions in the same hemisphere as the index lesion, and silent lesions in the opposite hemisphere. Lesion volumes for each region were examined for correlation with motor impairment scores, and subtraction analysis was used to highlight anatomical lesion loci associated with this deficit. Results For subtraction lesion analysis, including peri-necrotic tissue resulted in a larger region of more frequent damage being seen in the basal ganglia. For correlational analysis, only the volume of the lesion core was significantly associated with motor impairment scores (r = -0.35, p = 0.025. In a sub-analysis of patients with small subcortical index lesions, adding silent lesions in the opposite hemisphere to the volume of the index

Conspicuity of diffuse axonal injury lesions on diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Kinoshita, Toshibumi; Moritani, Toshio; Hiwatashi, Akio; Wang, Henry Z.; Shrier, David A.; Numaguchi, Yuji; Westesson, Per-Lennart A.

2005-01-01

Objective: (1) To detect diffuse axonal injury (DAI) lesions by diffusion-weighted imaging (DWI), as compared with fluid-attenuated inversion recovery (FLAIR) imaging and (2) to evaluate hemorrhagic DAI lesions by b 0 images obtained from DWI, as compared with gradient-echo (GRE) imaging. Methods: We reviewed MR images of 36 patients with a diagnosis of DAI. MR imaging was performed 20 h to 14 days (mean, 3.7 days) after traumatic brain injury. We evaluated: (1) conspicuity of lesions on DWI and FLAIR and (2) conspicuity of hemorrhage in DAI lesions on b 0 images and GRE imaging. Results: DWI clearly depicted high-signal DAI lesions. The sensitivity of DWI to lesional conspicuity in DAI lesions was almost equal to that of FLAIR. The sensitivity of b 0 images to identification of hemorrhagic DAI lesions was inferior to that of GRE. Conclusion: DWI is as useful as FLAIR in detecting DAI lesions. GRE imaging is still the superior tool for the evaluation of hemorrhagic DAI

On the effect of standard PFEM remeshing on volume conservation in free-surface fluid flow problems

Science.gov (United States)

Franci, Alessandro; Cremonesi, Massimiliano

2017-07-01

The aim of this work is to analyze the remeshing procedure used in the particle finite element method (PFEM) and to investigate how this operation may affect the numerical results. The PFEM remeshing algorithm combines the Delaunay triangulation and the Alpha Shape method to guarantee a good quality of the Lagrangian mesh also in large deformation processes. However, this strategy may lead to local variations of the topology that may cause an artificial change of the global volume. The issue of volume conservation is here studied in detail. An accurate description of all the situations that may induce a volume variation during the PFEM regeneration of the mesh is provided. Moreover, the crucial role of the parameter α used in the Alpha Shape method is highlighted and a range of values of α for which the differences between the numerical results are negligible, is found. Furthermore, it is shown that the variation of volume induced by the remeshing reduces by refining the mesh. This check of convergence is of paramount importance for the reliability of the PFEM. The study is carried out for 2D free-surface fluid dynamics problems, however the conclusions can be extended to 3D and to all those problems characterized by significant variations of internal and external boundaries.

Thallium pulmonary scintigraphy. Relationship to pulmonary fluid volumes during left atrial hypertension and the acute release of pressure

International Nuclear Information System (INIS)

Slutsky, R.A.

1984-01-01

To evaluate the relationship between thallium-201 lung activity and pulmonary fluid volumes, we compared thallium pulmonary scintigrams with measures of intravascular (PBV), extravascular (EVLW) and total lung water (TLW) during gradual left atrial (LA) hypertension and then serially after the acute release of pressure. The study group was composed of nine mongrel dogs who were each studied at seven levels of elevated LA pressure, and then every 15 minutes for 2 hours after the acute release of pressure. During LA pressure (congestion phase) elevation, lung counts (normalized for myocardial activity), correlated best with TLW (r . .91), rather than PBV (r . .84) or EVLW (r . .81). After the release of pressure (recovery phase), lung counts correlated well with EVLW (r . .92) and TLW (r . .82), but not with PBV (r . .28). Postmortem lung counts from 197 separate lung sections correlated well with the corresponding wet weight/dry weight ratio from that section (r . .81). Thus, we conclude that changes in pulmonary thallium emissions during cardiogenic pulmonary edema relate to corresponding changes in pulmonary fluid volumes. During congestion, the confounding effects of nonlinear increases in EVLW and PBV make thallium emissions more a marker of TLW than either the intravascular or extravascular pulmonary fluid compartment. After pressure release, PBV immediately returns to normal, at which time EVLW and pulmonary emissions correlate closely. These latter data, more applicable to postexercise stress thallium data, lend support to the hypothesis that elevated pulmonary emissions during postexercise thallium scintigrams reflect elevations in EVLW that develop during exercise

Smart fast blood counting of trace volumes of body fluids from various mammalian species using a compact custom-built microscope cytometer (Conference Presentation)

Science.gov (United States)

Smith, Zachary J.; Gao, Tingjuan; Lin, Tzu-Yin; Carrade-Holt, Danielle; Lane, Stephen M.; Matthews, Dennis L.; Dwyre, Denis M.; Wachsmann-Hogiu, Sebastian

2016-03-01

Cell counting in human body fluids such as blood, urine, and CSF is a critical step in the diagnostic process for many diseases. Current automated methods for cell counting are based on flow cytometry systems. However, these automated methods are bulky, costly, require significant user expertise, and are not well suited to counting cells in fluids other than blood. Therefore, their use is limited to large central laboratories that process enough volume of blood to recoup the significant capital investment these instruments require. We present in this talk a combination of a (1) low-cost microscope system, (2) simple sample preparation method, and (3) fully automated analysis designed for providing cell counts in blood and body fluids. We show results on both humans and companion and farm animals, showing that accurate red cell, white cell, and platelet counts, as well as hemoglobin concentration, can be accurately obtained in blood, as well as a 3-part white cell differential in human samples. We can also accurately count red and white cells in body fluids with a limit of detection ~3 orders of magnitude smaller than current automated instruments. This method uses less than 1 microliter of blood, and less than 5 microliters of body fluids to make its measurements, making it highly compatible with finger-stick style collections, as well as appropriate for small animals such as laboratory mice where larger volume blood collections are dangerous to the animal's health.

Annual review of fluid mechanics. Volume 22

International Nuclear Information System (INIS)

Lumley, J.L.; Van Dyke, M.; Reed, H.L.

1990-01-01

Topics presented include rapid granular flows, issues in viscoelastic fluid mechanics, wave loads on offshore structures, boundary layers in the general ocean circulation, parametrically forced surface waves, wave-mean flow interactions in the equatorial ocean, and local and global instabilities in spatially developing flows. Also presented are aerodynamics of human-powered flight, aerothermodynamics and transition in high-speed wind tunnels at NASA-Langley, wakes behind blunt bodies, and mixing, chaotic advection, and turbulence. Also addressed are the history of the Reynolds number, panel methods in computational fluid dynamics, numerical multipole and boundary integral equation techniques in Stokes flow, plasma turbulence, optical rheometry, and viscous-flow paradoxes

Diagnostic importance of 18F-FDG PET/CT parameters and total lesion glycolysis in differentiating between benign and malignant adrenal lesions.

Science.gov (United States)

Ciftci, Esra; Turgut, Bulent; Cakmakcilar, Ali; Erturk, Seyit A

2017-09-01

Benign adrenal lesions are prevalent in oncologic imaging and make metastatic disease diagnoses difficult. This study evaluates the diagnostic importance of metabolic, volumetric, and metabolovolumetric parameters measured by fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT in differentiating between benign and malignant adrenal lesions in cancer patients. In this retrospective study, we evaluated F-FDG PET/CT parameters of adrenal lesions of follow-up cancer patients referred to our clinic between January 2012 and November 2016. The diagnosis of adrenal malignant lesions was made on the basis of interval growth or reduction after chemotherapy. Patient demographics, analysis of metabolic parameters such as maximum standard uptake value (SUVmax), tumor SUVmax/liver SUVmean ratio (T/LR), morphologic parameters such as size, Hounsfield Units, and computed tomography (CT) volume, and metabolovolumetric parameters such as metabolic tumor volume and total lesion glycolysis (TLG) of adrenal lesions were calculated. PET/CT parameters were assessed using the Mann-Whitney U-test and receiving operating characteristic analysis. In total, 186 adrenal lesions in 163 cancer patients (108 men/54 women; mean±SD age: 64±10.9 years) were subjected to F-FDG PET/CT for tumor evaluation. SUVmax values (mean±SD) were 2.8±0.8 and 10.6±6; TLG were 10.8±9.2 and 124.4±347.9; and T/LR were 1±0.3 and 4.1±2.6 in benign and malignant adrenal lesions, respectively. On the basis of the area under the curve, adrenal lesion SUVmax and T/LR had similar highest diagnostic performance for predicting malignant lesions (area under the curve: 0.993 and 0.991, respectively, P<0.001). Multivariate logistic regression analysis showed that T/LR, adrenal lesion SUVmax, and Hounsfield Units were independent predictive factors for malignancy rather than TLG. Irrespective of whether TLG was statistically highly significant for differentiating benign from malignant adrenal lesions, it did not reach the

Flow rate measurement in a volume

Energy Technology Data Exchange (ETDEWEB)

Galvez, Cristhian

2018-04-17

A system for measuring flow rate within a volume includes one or more transmission devices that transmit one or more signals through fluid contained within the volume. The volume may be bounded, at least in part, by an outer structure and by an object at least partially contained within the outer structure. A transmission device located at a first location of the outer structure transmits a first signal to a second location of the outer structure. A second signal is transmitted through the fluid from the second location to a third location of the outer structure. The flow rate of the fluid within the volume may be determined based, at least in part, on the time of flight of both the first signal and the second signal.

Viable tumor volume: Volume of interest within segmented metastatic lesions, a pilot study of proposed computed tomography response criteria for urothelial cancer

International Nuclear Information System (INIS)

Folio, Les Roger; Turkbey, Evrim B.; Steinberg, Seth M.; Apolo, Andrea B.

2015-01-01

Highlights: • It is clear that 2D axial measurements are incomplete assessments in metastatic disease; especially in light of evolving antiangiogenic therapies that can result in tumor necrosis. • Our pilot study demonstrates that taking volumetric density into account can better predict overall survival when compared to RECIST, volumetric size, MASS and Choi. • Although volumetric segmentation and further density analysis may not yet be feasible within routine workflows, the authors believe that technology advances may soon make this possible. - Abstract: Objectives: To evaluate the ability of new computed tomography (CT) response criteria for solid tumors such as urothelial cancer (VTV; viable tumor volume) to predict overall survival (OS) in patients with metastatic bladder cancer treated with cabozantinib. Materials and methods: We compared the relative capabilities of VTV, RECIST, MASS (morphology, attenuation, size, and structure), and Choi criteria, as well as volume measurements, to predict OS using serial follow-up contrast-enhanced CT exams in patients with metastatic urothelial carcinoma. Kaplan–Meier curves and 2-tailed log-rank tests compared OS based on early RECIST 1.1 response against each of the other criteria. A Cox proportional hazards model assessed response at follow-up exams as a time-varying covariate for OS. Results: We assessed 141 lesions in 55CT scans from 17 patients with urothelial metastasis, comparing VTV, RECIST, MASS, and Choi criteria, and volumetric measurements, for response assessment. Median follow-up was 4.5 months, range was 2–14 months. Only the VTV criteria demonstrated a statistical association with OS (p = 0.019; median OS 9.7 vs. 3.5 months). Conclusion: This pilot study suggests that VTV is a promising tool for assessing tumor response and predicting OS, using criteria that incorporate tumor volume and density in patients receiving antiangiogenic therapy for urothelial cancer. Larger studies are warranted to

Extended two-fluid model for simulating magneto-rheological fluid flows

International Nuclear Information System (INIS)

Shivaram, A C

2011-01-01

The current practice of designing magneto-rheological (MR) fluid-based devices is, to a large extent, based on simple phenomenological models like the Bingham model. Though useful for initial force or torque estimation and sizing, these models lack the capability to predict performance degradation due to changes in the particle volume fraction distribution. The present work demonstrates the use of the two-fluid model for predicting the particle volume fraction distribution inside a device in the absence of a field and proposes a novel modeling scheme which can simulate the fluid flow in the presence of a field. This modeling scheme can be used to (a) visualize flow patterns inside a device under various operating conditions, (b) predict the spatial distribution of particles inside a device after multiple operating cycles, (c) assist in estimating the extent of performance degradation due to non-uniform particle distribution and (d) enable testing of various design strategies to mitigate such performance issues using simulations. This is illustrated through numerical examples of a few case studies of typical MR device configurations

An energy stable evolution method for simulating two-phase equilibria of multi-component fluids at constant moles, volume and temperature

KAUST Repository

Kou, Jisheng

2016-02-25

In this paper, we propose an energy-stable evolution method for the calculation of the phase equilibria under given volume, temperature, and moles (VT-flash). An evolution model for describing the dynamics of two-phase fluid system is based on Fick’s law of diffusion for multi-component fluids and the Peng-Robinson equation of state. The mobility is obtained from diffusion coefficients by relating the gradient of chemical potential to the gradient of molar density. The evolution equation for moles of each component is derived using the discretization of diffusion equations, while the volume evolution equation is constructed based on the mechanical mechanism and the Peng-Robinson equation of state. It is proven that the proposed evolution system can well model the VT-flash problem, and moreover, it possesses the property of total energy decay. By using the Euler time scheme to discretize this evolution system, we develop an energy stable algorithm with an adaptive choice strategy of time steps, which allows us to calculate the suitable time step size to guarantee the physical properties of moles and volumes, including positivity, maximum limits, and correct definition of the Helmhotz free energy function. The proposed evolution method is also proven to be energy-stable under the proposed time step choice. Numerical examples are tested to demonstrate efficiency and robustness of the proposed method.

A finite volume procedure for fluid flow, heat transfer and solid-body stress analysis

KAUST Repository

Jagad, P. I.

2018-04-12

A unified cell-centered unstructured mesh finite volume procedure is presented for fluid flow, heat transfer and solid-body stress analysis. An in-house procedure (A. W. Date, Solution of Transport Equations on Unstructured Meshes with Cell-Centered Colocated Variables. Part I: Discretization, International Journal of Heat and Mass Transfer, vol. 48 (6), 1117-1127, 2005) is extended to include the solid-body stress analysis. The transport terms for a cell-face are evaluated in a structured grid-like manner. The Cartesian gradients at the center of each cell-face are evaluated using the coordinate transformation relations. The accuracy of the procedure is demonstrated by solving several benchmark problems involving different boundary conditions, source terms, and types of loading.

OASIS is Automated Statistical Inference for Segmentation, with applications to multiple sclerosis lesion segmentation in MRI.

Science.gov (United States)

Sweeney, Elizabeth M; Shinohara, Russell T; Shiee, Navid; Mateen, Farrah J; Chudgar, Avni A; Cuzzocreo, Jennifer L; Calabresi, Peter A; Pham, Dzung L; Reich, Daniel S; Crainiceanu, Ciprian M

2013-01-01

Magnetic resonance imaging (MRI) can be used to detect lesions in the brains of multiple sclerosis (MS) patients and is essential for diagnosing the disease and monitoring its progression. In practice, lesion load is often quantified by either manual or semi-automated segmentation of MRI, which is time-consuming, costly, and associated with large inter- and intra-observer variability. We propose OASIS is Automated Statistical Inference for Segmentation (OASIS), an automated statistical method for segmenting MS lesions in MRI studies. We use logistic regression models incorporating multiple MRI modalities to estimate voxel-level probabilities of lesion presence. Intensity-normalized T1-weighted, T2-weighted, fluid-attenuated inversion recovery and proton density volumes from 131 MRI studies (98 MS subjects, 33 healthy subjects) with manual lesion segmentations were used to train and validate our model. Within this set, OASIS detected lesions with a partial area under the receiver operating characteristic curve for clinically relevant false positive rates of 1% and below of 0.59% (95% CI; [0.50%, 0.67%]) at the voxel level. An experienced MS neuroradiologist compared these segmentations to those produced by LesionTOADS, an image segmentation software that provides segmentation of both lesions and normal brain structures. For lesions, OASIS out-performed LesionTOADS in 74% (95% CI: [65%, 82%]) of cases for the 98 MS subjects. To further validate the method, we applied OASIS to 169 MRI studies acquired at a separate center. The neuroradiologist again compared the OASIS segmentations to those from LesionTOADS. For lesions, OASIS ranked higher than LesionTOADS in 77% (95% CI: [71%, 83%]) of cases. For a randomly selected subset of 50 of these studies, one additional radiologist and one neurologist also scored the images. Within this set, the neuroradiologist ranked OASIS higher than LesionTOADS in 76% (95% CI: [64%, 88%]) of cases, the neurologist 66% (95% CI: [52%, 78

A combined volume-of-fluid method and low-Mach-number approach for DNS of evaporating droplets in turbulence

Science.gov (United States)

Dodd, Michael; Ferrante, Antonino

2017-11-01

Our objective is to perform DNS of finite-size droplets that are evaporating in isotropic turbulence. This requires fully resolving the process of momentum, heat, and mass transfer between the droplets and surrounding gas. We developed a combined volume-of-fluid (VOF) method and low-Mach-number approach to simulate this flow. The two main novelties of the method are: (i) the VOF algorithm captures the motion of the liquid gas interface in the presence of mass transfer due to evaporation and condensation without requiring a projection step for the liquid velocity, and (ii) the low-Mach-number approach allows for local volume changes caused by phase change while the total volume of the liquid-gas system is constant. The method is verified against an analytical solution for a Stefan flow problem, and the D2 law is verified for a single droplet in quiescent gas. We also demonstrate the schemes robustness when performing DNS of an evaporating droplet in forced isotropic turbulence.

Conspicuity of diffuse axonal injury lesions on diffusion-weighted MR imaging

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, Toshibumi [Department of Radiology, Division of Neuroradiology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 648, Rochester, NY 14642 (United States)]. E-mail: kino@grape.med.tottori-u.ac.jp; Moritani, Toshio [Department of Radiology, Division of Neuroradiology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 648, Rochester, NY 14642 (United States); Hiwatashi, Akio [Department of Radiology, Division of Neuroradiology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 648, Rochester, NY 14642 (United States); Wang, Henry Z. [Department of Radiology, Division of Neuroradiology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 648, Rochester, NY 14642 (United States); Shrier, David A. [Department of Radiology, Division of Neuroradiology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 648, Rochester, NY 14642 (United States); Numaguchi, Yuji [Department of Radiology, Division of Neuroradiology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 648, Rochester, NY 14642 (United States); Westesson, Per-Lennart A. [Department of Radiology, Division of Neuroradiology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 648, Rochester, NY 14642 (United States)

2005-10-01

Objective: (1) To detect diffuse axonal injury (DAI) lesions by diffusion-weighted imaging (DWI), as compared with fluid-attenuated inversion recovery (FLAIR) imaging and (2) to evaluate hemorrhagic DAI lesions by b{sub 0} images obtained from DWI, as compared with gradient-echo (GRE) imaging. Methods: We reviewed MR images of 36 patients with a diagnosis of DAI. MR imaging was performed 20 h to 14 days (mean, 3.7 days) after traumatic brain injury. We evaluated: (1) conspicuity of lesions on DWI and FLAIR and (2) conspicuity of hemorrhage in DAI lesions on b{sub 0} images and GRE imaging. Results: DWI clearly depicted high-signal DAI lesions. The sensitivity of DWI to lesional conspicuity in DAI lesions was almost equal to that of FLAIR. The sensitivity of b{sub 0} images to identification of hemorrhagic DAI lesions was inferior to that of GRE. Conclusion: DWI is as useful as FLAIR in detecting DAI lesions. GRE imaging is still the superior tool for the evaluation of hemorrhagic DAI.

Gingival crevicular fluid volume and periodontal parameters alterations after use of conventional and self-ligating brackets.

Science.gov (United States)

Bergamo, Ana Zn; Nelson-Filho, Paulo; Romano, Fábio L; da Silva, Raquel Ab; Saraiva, Maria Cp; da Silva, Lea Ab; Matsumoto, Mirian An

2016-12-01

The aim of this study was to evaluate the alterations on plaque index (PI), gingival index (GI), gingival bleeding index (GBI), and gingival crevicular fluid (GCF) volume after use of three different brackets types for 60 days. Setting Participants: The sample comprised 20 patients of both sexes aged 11-15 years (mean age: 13.3 years), with permanent dentition, adequate oral hygiene, and mild tooth crowding, overjet, and overbite. A conventional metallic bracket Gemini™, and two different brands of self-ligating brackets - In-Ovation ® R and SmartClip™ - were bonded to the maxillary incisors and canines. PI, GI, GBI scores, and GCF volume were measured before and 30 and 60 days after bonding of the brackets. Data were analysed statistically using non-parametric tests coefficient at a 5% significance level. There was no statistically significant correlation (P > 0.05) between tooth crowding, overjet, and overbite and the PI, GI, GBI scores, and GCF volume before bonding, indicating no influence of malocclusion on the clinical parameters. Regardless of the bracket design, no statistically significant difference (P > 0.05) was found for GI, GBI scores. PI and GCF volume showed a significant difference among the brackets in different periods. In pairwise comparisons a significant difference was observed when compared before with 60 days after bonding, for the teeth bonded with SmartClip™ self-ligating bracket, (PI P = 0.009; GCF volume P = 0.001). There was an increase in PI score and GCF volume 60 days after bonding of SmartClip™ self-ligating brackets, indicating the influence of bracket design on these clinical parameters.

Changes in the peritoneal fluid of horses with abdominal discomfort and its relations to the kind and evolution of the lesion after medical or surgical treatment: study of 74 cases

Directory of Open Access Journals (Sweden)

Raquel Yvonne Arantes Baccarin

1995-12-01

Full Text Available The purpose of this paper is to view the interrelation between the peritoneal fluid analysis from horses with abdominal discomfort, regarding the pathology site, the occurrence or not of strangulating obstruction, the treatment performed and the presence of peritoneal fluid, classified either as modified transudate or exsudate. In order to achieve that, 373 clinical records of colicky horses referred to the Veterinary Hospital between 1985 and 1991 were studied, and 98 of these, were selected, in which peritoneal fluid sampling and analysis had been carried out in a routine manner. Greater amount of exsudate than that of modified transudate was observed. Horses with wide spread intestinal disease showed the best recovery rates. Regardless of the site of the lesion, those exhibiting strangulating obstruction had the lowest rates of survival, and this kind of obstruction was more frequently observed in the small intestine. Among the parameters considered in the peritoneal fluid analysis, fluid color was the most reliable indicator od strangulating obstruction and/or intestinal ischemia. Finally, peritoneal fluid analysis and citology alone were not sufficient to diagnose the cause of the colic, due to the great variation observed in each pathology group: associated to the clinical evaluation of the patient, however, they can bring up the need for surgical intervention.

Epidural anesthesia, hypotension, and changes in intravascular volume

DEFF Research Database (Denmark)

Holte, Kathrine; Foss, Nicolai B; Svensén, Christer

2004-01-01

receiving hydroxyethyl starch. RESULTS: Plasma volume did not change per se after thoracic epidural anesthesia despite a decrease in blood pressure. Plasma volume increased with fluid administration but remained unchanged with vasopressors despite that both treatments had similar hemodynamic effects...... constant was 56 ml/min. CONCLUSIONS: Thoracic epidural anesthesia per se does not lead to changes in blood volumes despite a reduction in blood pressure. When fluid is infused, there is a dilution, and the fluid initially seems to be located centrally. Because administration of hydroxyethyl starch......BACKGROUND: The most common side effect of epidural or spinal anesthesia is hypotension with functional hypovolemia prompting fluid infusions or administration of vasopressors. Short-term studies (20 min) in patients undergoing lumbar epidural anesthesia suggest that plasma volume may increase when...

Fluid balance concepts in medicine: Principles and practice

Science.gov (United States)

Roumelioti, Maria-Eleni; Glew, Robert H; Khitan, Zeid J; Rondon-Berrios, Helbert; Argyropoulos, Christos P; Malhotra, Deepak; Raj, Dominic S; Agaba, Emmanuel I; Rohrscheib, Mark; Murata, Glen H; Shapiro, Joseph I; Tzamaloukas, Antonios H

2018-01-01

The regulation of body fluid balance is a key concern in health and disease and comprises three concepts. The first concept pertains to the relationship between total body water (TBW) and total effective solute and is expressed in terms of the tonicity of the body fluids. Disturbances in tonicity are the main factor responsible for changes in cell volume, which can critically affect brain cell function and survival. Solutes distributed almost exclusively in the extracellular compartment (mainly sodium salts) and in the intracellular compartment (mainly potassium salts) contribute to tonicity, while solutes distributed in TBW have no effect on tonicity. The second body fluid balance concept relates to the regulation and measurement of abnormalities of sodium salt balance and extracellular volume. Estimation of extracellular volume is more complex and error prone than measurement of TBW. A key function of extracellular volume, which is defined as the effective arterial blood volume (EABV), is to ensure adequate perfusion of cells and organs. Other factors, including cardiac output, total and regional capacity of both arteries and veins, Starling forces in the capillaries, and gravity also affect the EABV. Collectively, these factors interact closely with extracellular volume and some of them undergo substantial changes in certain acute and chronic severe illnesses. Their changes result not only in extracellular volume expansion, but in the need for a larger extracellular volume compared with that of healthy individuals. Assessing extracellular volume in severe illness is challenging because the estimates of this volume by commonly used methods are prone to large errors in many illnesses. In addition, the optimal extracellular volume may vary from illness to illness, is only partially based on volume measurements by traditional methods, and has not been determined for each illness. Further research is needed to determine optimal extracellular volume levels in several

Development, Verification and Validation of Parallel, Scalable Volume of Fluid CFD Program for Propulsion Applications

Science.gov (United States)

West, Jeff; Yang, H. Q.

2014-01-01

There are many instances involving liquid/gas interfaces and their dynamics in the design of liquid engine powered rockets such as the Space Launch System (SLS). Some examples of these applications are: Propellant tank draining and slosh, subcritical condition injector analysis for gas generators, preburners and thrust chambers, water deluge mitigation for launch induced environments and even solid rocket motor liquid slag dynamics. Commercially available CFD programs simulating gas/liquid interfaces using the Volume of Fluid approach are currently limited in their parallel scalability. In 2010 for instance, an internal NASA/MSFC review of three commercial tools revealed that parallel scalability was seriously compromised at 8 cpus and no additional speedup was possible after 32 cpus. Other non-interface CFD applications at the time were demonstrating useful parallel scalability up to 4,096 processors or more. Based on this review, NASA/MSFC initiated an effort to implement a Volume of Fluid implementation within the unstructured mesh, pressure-based algorithm CFD program, Loci-STREAM. After verification was achieved by comparing results to the commercial CFD program CFD-Ace+, and validation by direct comparison with data, Loci-STREAM-VoF is now the production CFD tool for propellant slosh force and slosh damping rate simulations at NASA/MSFC. On these applications, good parallel scalability has been demonstrated for problems sizes of tens of millions of cells and thousands of cpu cores. Ongoing efforts are focused on the application of Loci-STREAM-VoF to predict the transient flow patterns of water on the SLS Mobile Launch Platform in order to support the phasing of water for launch environment mitigation so that vehicle determinantal effects are not realized.

Fluid Mechanics of Fish Swimming

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 1. Fluid Mechanics of Fish Swimming - Lift-based Propulsion. Jaywant H Arakeri. General Article Volume 14 Issue 1 January 2009 pp 32-46. Fulltext. Click here to view fulltext PDF. Permanent link:

Development of a theoretical framework for analyzing cerebrospinal fluid dynamics

Directory of Open Access Journals (Sweden)

Vedel Søren

2009-09-01

Full Text Available Abstract Background To date hydrocephalus researchers acknowledge the need for rigorous but utilitarian fluid mechanics understanding and methodologies in studying normal and hydrocephalic intracranial dynamics. Pressure volume models and electric circuit analogs introduced pressure into volume conservation; but control volume analysis enforces independent conditions on pressure and volume. Previously, utilization of clinical measurements has been limited to understanding of the relative amplitude and timing of flow, volume and pressure waveforms; qualitative approaches without a clear framework for meaningful quantitative comparison. Methods Control volume analysis is presented to introduce the reader to the theoretical background of this foundational fluid mechanics technique for application to general control volumes. This approach is able to directly incorporate the diverse measurements obtained by clinicians to better elucidate intracranial dynamics and progression to disorder. Results Several examples of meaningful intracranial control volumes and the particular measurement sets needed for the analysis are discussed. Conclusion Control volume analysis provides a framework to guide the type and location of measurements and also a way to interpret the resulting data within a fundamental fluid physics analysis.

A matrix-free implicit unstructured multigrid finite volume method for simulating structural dynamics and fluid structure interaction

Science.gov (United States)

Lv, X.; Zhao, Y.; Huang, X. Y.; Xia, G. H.; Su, X. H.

2007-07-01

A new three-dimensional (3D) matrix-free implicit unstructured multigrid finite volume (FV) solver for structural dynamics is presented in this paper. The solver is first validated using classical 2D and 3D cantilever problems. It is shown that very accurate predictions of the fundamental natural frequencies of the problems can be obtained by the solver with fast convergence rates. This method has been integrated into our existing FV compressible solver [X. Lv, Y. Zhao, et al., An efficient parallel/unstructured-multigrid preconditioned implicit method for simulating 3d unsteady compressible flows with moving objects, Journal of Computational Physics 215(2) (2006) 661-690] based on the immersed membrane method (IMM) [X. Lv, Y. Zhao, et al., as mentioned above]. Results for the interaction between the fluid and an immersed fixed-free cantilever are also presented to demonstrate the potential of this integrated fluid-structure interaction approach.

Radiation planning in small complex lesions and experimental verification

International Nuclear Information System (INIS)

Jess-Hempen, A.; Wowra, B.; Mack, A.; Kreiner, H.J.; Heck, B.

2003-01-01

The Gamma Knife is used as a sterotactic tool for the conformal treatment of very small, complex-shape cranial lesions. The combination of planning software and treatment equipment enables a highly-precise conformal dose distribution and positioning. The purpose of the present study was to experimentally verify the precision actually achievable in case of extremely irregular, small target volumes. For this purpose, a complete treatment procedure was performed using a standard head phantom complemented with a specially developed insert that simulates an L-shaped lesion. The spatial precision of the irradiation was recorded by means of high-resolution film dosimetry using GafChromic TM films. The analysis of the films showed for the film in the center plane an excellent conformity of the 75% isodose line used to circumscribe the lesion. A very good agreement between planning and measurement resulted also for isodose lines residing outside of the target volume. (orig.) [de

Influence of Bleeding Pattern on Ischemic Lesions After Spontaneous Hypertensive Intracerebral Hemorrhage with Intraventricular Hemorrhage.

Science.gov (United States)

Rivera-Lara, Lucia; Murthy, Santosh B; Nekoovaght-Tak, Saman; Ali, Hasan; McBee, Nichol; Dlugash, Rachel; Ram, Malathi; Thompson, Richard; Awad, Issam A; Hanley, Daniel F; Ziai, Wendy C

2018-03-27

Concomitant acute ischemic lesions are detected in up to a quarter of patients with spontaneous intracerebral hemorrhage (ICH). Influence of bleeding pattern and intraventricular hemorrhage (IVH) on risk of ischemic lesions has not been investigated. Retrospective study of all 500 patients enrolled in the CLEAR III randomized controlled trial of thrombolytic removal of obstructive IVH using external ventricular drainage. The primary outcome measure was radiologically confirmed ischemic lesions, as reported by the Safety Event Committee and confirmed by two neurologists. We assessed predictors of ischemic lesions including analysis of bleeding patterns (ICH, IVH and subarachnoid hemorrhage) on computed tomography scans (CT). Secondary outcomes were blinded assessment of mortality and modified Rankin scale (mRS) at 30 and 180 days. Ischemic lesions occurred in 23 (4.6%) during first 30 days after ICH. Independent risk factors associated with ischemic lesions in logistic regression models adjusted for confounders were higher IVH volume (p = 0.004) and persistent subarachnoid hemorrhage on CT scan (p = 0.03). Patients with initial IVH volume ≥ 15 ml had five times the odds of concomitant ischemic lesions compared to IVH volume < 15 ml. Patients with ischemic lesions had significantly higher odds of death at 1 and 6 months (but not poor outcome; mRS 4-6) compared to patients without concurrent ischemic lesions. Occurrence of ischemic lesions in the acute phase of IVH is not uncommon and is significantly associated with increased early and late mortality. Extra-parenchymal blood (larger IVH and visible subarachnoid hemorrhage) is a strong predictor for development of concomitant ischemic lesions after ICH.

Intraoperative Fluids and Fluid Management for Ambulatory Dental Sedation and General Anesthesia.

Science.gov (United States)

Saraghi, Mana

2015-01-01

Intravenous fluids are administered in virtually every parenteral sedation and general anesthetic. The purpose of this article is to review the physiology of body-water distribution and fluid dynamics at the vascular endothelium, evaluation of fluid status, calculation of fluid requirements, and the clinical rationale for the use of various crystalloid and colloid solutions. In the setting of elective dental outpatient procedures with minor blood loss, isotonic balanced crystalloid solutions are the fluids of choice. Colloids, on the other hand, have no use in outpatient sedation or general anesthesia for dental or minor oral surgery procedures but may have several desirable properties in long and invasive maxillofacial surgical procedures where advanced hemodynamic monitoring may assess the adequacy of intravascular volume.

Flat-Panel Detector—Based Volume Computed Tomography: A Novel 3D Imaging Technique to Monitor Osteolytic Bone Lesions in a Mouse Tumor Metastasis Model

Directory of Open Access Journals (Sweden)

Jeannine Missbach-Guentner

2007-09-01

Full Text Available Skeletal metastasis is an important cause of mortality in patients with breast cancer. Hence, animal models, in combination with various imaging techniques, are in high demand for preclinical assessment of novel therapies. We evaluated the applicability of flat-panel volume computed tomography (fpVCT to noninvasive detection of osteolytic bone metastases that develop in severe immunodeficient mice after intracardial injection of MDA-MB-231 breast cancer cells. A single fpVCT scan at 200-wm isotropic resolution was employed to detect osteolysis within the entire skeleton. Osteolytic lesions identified by fpVCT correlated with Faxitron X-ray analysis and were subsequently confirmed by histopathological examination. Isotropic three-dimensional image data sets obtained by fpVCT were the basis for the precise visualization of the extent of the lesion within the cortical bone and for the measurement of bone loss. Furthermore, fpVCT imaging allows continuous monitoring of growth kinetics for each metastatic site and visualization of lesions in more complex regions of the skeleton, such as the skull. Our findings suggest that fpVCT is a powerful tool that can be used to monitor the occurrence and progression of osteolytic lesions in vivo and can be further developed to monitor responses to antimetastatic therapies over the course of the disease.

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1

International Nuclear Information System (INIS)

1992-06-01

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3

International Nuclear Information System (INIS)

1992-06-01

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2

International Nuclear Information System (INIS)

1992-06-01

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems

Bioimpedance Spectroscopy for Assessment of Volume Status in Patients before and after General Anaesthesia

Science.gov (United States)

Ernstbrunner, Matthäus; Kostner, Lisa; Kimberger, Oliver; Wabel, Peter; Säemann, Marcus; Markstaller, Klaus; Fleischmann, Edith; Kabon, Barbara; Hecking, Manfred

2014-01-01

Background Technically assisted assessment of volume status before surgery may be useful to direct intraoperative fluid administration. We therefore tested a recently developed whole-body bioimpedance spectroscopy device to determine pre- to postoperative fluid distribution. Methods Using a three-compartment physiologic tissue model, the body composition monitor (BCM, Fresenius Medical Care, Germany) measures total body fluid volume, extracellular volume, intracellular volume and fluid overload as surplus or deficit of ‘normal’ extracellular volume. BCM-measurements were performed before and after standardized general anaesthesia for gynaecological procedures (laparotomies, laparoscopies and vaginal surgeries). BCM results were blinded to the attending anaesthesiologist and data analysed using the 2-sided, paired Student’s t-test and multiple linear regression. Results In 71 females aged 45±15 years with body weight 67±13 kg and duration of anaesthesia 154±68 min, pre- to postoperative fluid overload increased from −0.7±1.1 L to 0.1±1.0 L, corresponding to −5.1±7.5% and 0.8±6.7% of normal extracellular volume, respectively (both p<0.001), after patients had received 1.9±0.9 L intravenous crystalloid fluid. Perioperative urinary excretion was 0.4±0.3 L. The increase in extracellular volume was paralleled by an increase in total body fluid volume, while intracellular volume increased only slightly and without reaching statistical significance (p = 0.15). Net perioperative fluid balance (administered fluid volume minus urinary excretion) was significantly associated with change in extracellular volume (r2 = 0.65), but was not associated with change in intracellular volume (r2 = 0.01). Conclusions Routine intraoperative fluid administration results in a significant, and clinically meaningful increase in the extracellular compartment. BCM-measurements yielded plausible results and may become useful to guide intraoperative fluid therapy in

Application of whole-lesion histogram analysis of pharmacokinetic parameters in dynamic contrast-enhanced MRI of breast lesions with the CAIPIRINHA-Dixon-TWIST-VIBE technique.

Science.gov (United States)

Li, Zhiwei; Ai, Tao; Hu, Yiqi; Yan, Xu; Nickel, Marcel Dominik; Xu, Xiao; Xia, Liming

2018-01-01

To investigate the application of whole-lesion histogram analysis of pharmacokinetic parameters for differentiating malignant from benign breast lesions on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). In all, 92 women with 97 breast lesions (26 benign and 71 malignant lesions) were enrolled in this study. Patients underwent dynamic breast MRI at 3T using a prototypical CAIPIRINHA-Dixon-TWIST-VIBE (CDT-VIBE) sequence and a subsequent surgery or biopsy. Inflow rate of the agent between plasma and interstitium (K trans ), outflow rate of agent between interstitium and plasma (K ep ), extravascular space volume per unit volume of tissue (v e ) including mean value, 25th/50th/75th/90th percentiles, skewness, and kurtosis were then calculated based on the whole lesion. A single-sample Kolmogorov-Smirnov test, paired t-test, and receiver operating characteristic curve (ROC) analysis were used for statistical analysis. Malignant breast lesions had significantly higher K trans , K ep , and lower v e in mean values, 25th/50th/75th/90th percentiles, and significantly higher skewness of v e than benign breast lesions (all P 0.05). The 90th percentile of K trans , the 90th percentile of K ep , and the 50th percentile of v e showed the greatest areas under the ROC curve (AUC) for each pharmacokinetic parameter derived from DCE-MRI. The 90th percentile of K ep achieved the highest AUC value (0.927) among all histogram-derived values. The whole-lesion histogram analysis of pharmacokinetic parameters can improve the diagnostic accuracy of breast DCE-MRI with the CDT-VIBE technique. The 90th percentile of K ep may be the best indicator in differentiation between malignant and benign breast lesions. 4 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2018;47:91-96. © 2017 International Society for Magnetic Resonance in Medicine.

MRI of the cystic mass lesions of the pancreas

International Nuclear Information System (INIS)

Ohtomo, Kuni; Itai, Yuji; Yoshikawa, Koki; Kokubo, Takashi; Yashiro, Naofumi; Iio, Masahiro

1987-01-01

Five cystic mass lesions of the pancreas were exemined by MRI. Multiplocular fluid components were demonstrated as areas of various signal intensity in mucinous cystadenoma and cystadenocarcinoma. Gas within the cystic mass was noted in ductectatic mucinous cystadenocarcinoma. Honeycomb pattern and classification were not depicted in serous cystadenoma. Necrotic matter was demonstrated as area of lower signal than liver in pseudocyst. These results were then compared with CT and ultrasound and at present enhanced CT combined with ultrasound is more diagnostic than MRI for cystic mass lesions of the pancreas. (author)

Introduction to thermal and fluid engineering

CERN Document Server

Kraus, Allan D; Aziz, Abdul; Ghajar, Afshin J

2011-01-01

The Thermal/Fluid Sciences: Introductory ConceptsThermodynamicsFluid MechanicsHeat TransferEngineered Systems and ProductsHistorical DevelopmentThe Thermal/Fluid Sciences and the EnvironmentThermodynamics: Preliminary Concepts and DefinitionsThe Study of ThermodynamicsSome DefinitionsDimensions and UnitsDensity and Related PropertiesPressureTemperature and the Zeroth Law of ThermodynamicsProblem-Solving MethodologyEnergy and the First Law of ThermodynamicsKinetic, Potential, and Internal EnergyWorkHeatThe First Law of ThermodynamicsThe Energy Balance for Closed SystemsThe Ideal Gas ModelIdeal Gas Enthalpy and Specific HeatsProcesses of an Ideal GasProperties of Pure, Simple Compressible SubstancesThe State PostulateP-v-T RelationshipsThermodynamic Property DataThe T-s and h-s DiagramsReal Gas BehaviorEquations of StateThe Polytropic Process for an Ideal GasControl Volume Mass and Energy Analysis The Control VolumeConservation of MassConservation of Energy for a Control VolumeSpecific Heats of Incompressible S...

Plasma Volume Expansion Resulting from Intravenous Glucose Tolerance Test

Directory of Open Access Journals (Sweden)

Robert G. Hahn

2011-01-01

Full Text Available Objective. To quantify the degree of plasma volume expansion that occurs during an intravenous glucose tolerance test (IVGTT. Methods. Twenty healthy volunteers (mean age, 28 years underwent IVGTTs in which 0.3 g/kg of glucose 30% was injected as a bolus over 1 min. Twelve blood samples were collected over 75 min. The plasma glucose and blood hemoglobin concentrations were used to calculate the volume distribution (Vd and the clearance (CL of both the exogenous glucose and the injected fluid volume. Results. The IVGTT caused a virtually instant plasma volume expansion of 10%. The half-life of the glucose averaged 15 min and the plasma volume expansion 16 min. Correction of the fluid kinetic model for osmotic effects after injection reduced CL for the infused volume by 85%, which illustrates the strength of osmosis in allocating fluid back to the intracellular fluid space. Simulations indicated that plasma volume expansion can be reduced to 60% by increasing the injection time from 1 to 5 min and reducing the glucose load from 0.3 to 0.2 g/kg. Conclusion. A regular IVGTT induced an acute plasma volume expansion that peaked at 10% despite the fact that only 50–80 mL of fluid were administered.

Combination of cyst fluid CEA and CA 125 is an accurate diagnostic tool for differentiating mucinous cystic neoplasms from intraductal papillary mucinous neoplasms.

Science.gov (United States)

Nagashio, Yoshikuni; Hijioka, Susumu; Mizuno, Nobumasa; Hara, Kazuo; Imaoka, Hiroshi; Bhatia, Vikram; Niwa, Yasumasa; Tajika, Masahiro; Tanaka, Tsutomu; Ishihara, Makoto; Shimizu, Yasuhiro; Hosoda, Waki; Yatabe, Yasushi; Yamao, Kenji

2014-01-01

Despite advances in imaging techniques, diagnosis and management of pancreatic cystic lesions still remains challenging. The objective of this study was to determine the utility of cyst fluid analysis (CEA, CA 19-9, CA 125, amylase, and cytology) in categorizing pancreatic cystic lesions, and in differentiating malignant from benign cystic lesions. A retrospective analysis of 68 patients with histologically and clinically confirmed cystic lesions was performed. Cyst fluid was obtained by surgical resection (n = 45) or endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) (n = 23). Cyst fluid tumor markers and amylase were measured and compared between the cyst types. Receiver operating characteristic (ROC) curve analysis of the tumor markers demonstrated that cyst fluid CEA provided the greatest area under ROC curve (AUC) (0.884) for differentiating mucinous versus non-mucinous cystic lesions. When a CEA cutoff value was set at 67.3 ng/ml, the sensitivity, specificity and accuracy for diagnosing mucinous cysts were 89.2%, 77.8%, and 84.4%, respectively. The combination of cyst fluid CEA content >67.3 ng/ml and cyst fluid CA 125 content >10.0 U/ml segregated 77.8% (14/18) of mucinous cystic neoplasms (MCNs) from other cyst subtypes. On the other hand, no fluid marker was useful for differentiating malignant versus benign cystic lesions. Although cytology (accuracy 83.3%) more accurately diagnosed malignant cysts than CEA (accuracy 65.6%), it lacked sensitivity (35.3%). Our results demonstrate that cyst fluid CEA can be a helpful marker in differentiating mucinous from non-mucinous, but not malignant from benign cystic lesions. A combined CEA and CA 125 approach may help segregate MCNs from IPMNs. Copyright © 2014 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Introduction to mathematical fluid dynamics

CERN Document Server

Meyer, Richard E

2010-01-01

An introduction to the behavior of liquids and gases, this volume provides excellent coverage of kinematics, momentum principle, Newtonian fluid, rotating fluids, compressibility, and more. It is geared toward advanced undergraduate and graduate students of mathematics and general science, and it requires a background in calculus and vector analysis. 1971 edition.

Annual review of fluid mechanics. Volume 15

International Nuclear Information System (INIS)

Van Dyke, M.; Wehausen, J.V.; Lumley, J.L.

1983-01-01

A survey of experimental results and analytical techniques for modelling various flows and the behavior of flows around flown-driven machinery is presented. Attention is given to analytical models for wind flows and power extraction by horizontal axis wind turbines. The phenomena occurring in the impact of compressible fluids with a solid body are described, as are the instabilities, pattern formation, and turbulence in flames. Homogeneous turbulence is explored, theories for autorotation by falling bodies are discussed, and attention is devoted to theoretical models for magneto-atmospheric waves and their presence in solar activity. The design characteristics of low Reynolds number airfoils are explored, and numerical and fluid mechanics formulations for integrable, chaotic, and turbulent vortex motion in two-dimensional flows are reviewed. Finally, measurements and models of turbulent wall jets for engineering purposes are examined

Continuous infusion of small-volume fluid resuscitation in the treatment of combined uncontrolled hemorrhagic shock and head injury

International Nuclear Information System (INIS)

Hayrettin, O.; Yagmur, Y.; Tas, A.; Topcu, S.; Orak, M.

2007-01-01

To determine the effect of continuous limited fluid resuscitation on the hemodynamic response and survival in rats in a model of uncontrolled hemorrhage shock due to Massive Splenic Injury (MSI) and Head Injury (HI). Seventy Sprague-Dawley rats were used in this study. Group 1 rats (n=10) was sham-operated. In group 2 (n=10), only Massive Splenic Injury (MSI) was performed and untreated. In group 3 (n=10), only head injury (HI) was performed and untreated. In group 4 (n=10), HI and MSI were performed and were untreated. In group 5 (n=10), HI and MSI were performed and 15 minutes later treated with 7.5% NaCl. In group 6 (n=10), HI and MSI were performed, and rats were treated with Ringer's Lactate (RL) solution. In group 7 (n=10), HI and MSI were performed, rats were treated with 0.9 % NaCl. In groups 2,4,5,6 and 7 midline incision was reopened and splenectomy was performed at 45 minutes. In group 4 rats, Mean Arterial Pressure (MAP) was decreased from 104 +- 6.1 mmHg to 75 +- 19.5 mmHg at 15 minutes; heart rate decreased from 357+- 24.9 beats/min to 321 +- 62.1 beats/min and hematocrit decreased from 46 +- 1.3 % to 43 +- 2.5 % (p<0.01). Similar early changes in MAP, heart rate and hematocrit were observed in groups 5, 6, and 7, at 15 minutes. At 45,60 and 120 minutes, in fluid resuscitated rats (group 5,6,7) MAP, heart rate and hematocrit values were measured higher than group 2 and 4 (p<0.01 for all). At 120 min. in group 6, hematocrit was higher than group 4, 5 and 7, in group 6, total blood loss after splenectomy was calculated at 20 +- 2.4% of blood volume and was the best value compared to other fluid resuscitated group 5 and 7 (28% and 27% of blood volume) (p<0.01). Mortality was lower in all fluid resuscitated groups when compared to group 3 and 4 (p< 0.05). The median survival time was again higher in fluid resuscitated groups. Continuous infusion of 7.5% NaCl, RL and 0.9 % NaCl following uncontrolled hemorrhagic shock with massive splenic injury and

MR in phenylketonuria-related brain lesions

International Nuclear Information System (INIS)

Dezortova, M.; Hajek, M.; Tintra, J.; Hejcmanova, L.; Sykova, E.

2001-01-01

Purpose: Phenylketonuria (PKU) patients were examined by different MR techniques to explain the pathological changes observed in periventricular white brain matter using conventional MR imaging. Material and Methods: Fifteen patients with treated classical PKU were examined by 1 H spectroscopy, relaxometry and diffusion imaging on a whole-body 1.5-T MR imager. Results: Known PKU lesions characterized by T2 enhancement in periventricular white matter were observed in all patients. The MR spectra from the lesioned areas showed a significant decrease in choline concentration. The mean ADC of water decreased and tortuosity increased in PKU lesions compared to control data. Conclusion: The results support the following hypothesis: The T2 increase in the PKU lesion reflects a raised concentration of free water molecules (about 15%) that have an increased trajectory between collisions compared to the same region in controls. The increase in water mobility might be explained by changes in extracellular space volume and myelin sheaths, which, presumably, have a different geometry with more hydrophobic sites in PKU patients. The changes result in increased tortuosity and may be confirmed by the loss of anisotropy in PKU lesions

MR in phenylketonuria-related brain lesions

Energy Technology Data Exchange (ETDEWEB)

Dezortova, M.; Hajek, M.; Tintra, J. [Inst. for Clinical and Experimental Medicine, Prague (Czech Republic); Hejcmanova, L. [Charles University, Prague (Czech Republic). 3rd Medical Faculty; Sykova, E. [Charles University, Prague (Czech Republic). 2nd Medical Faculty

2001-09-01

Purpose: Phenylketonuria (PKU) patients were examined by different MR techniques to explain the pathological changes observed in periventricular white brain matter using conventional MR imaging. Material and Methods: Fifteen patients with treated classical PKU were examined by {sup 1}H spectroscopy, relaxometry and diffusion imaging on a whole-body 1.5-T MR imager. Results: Known PKU lesions characterized by T2 enhancement in periventricular white matter were observed in all patients. The MR spectra from the lesioned areas showed a significant decrease in choline concentration. The mean ADC of water decreased and tortuosity increased in PKU lesions compared to control data. Conclusion: The results support the following hypothesis: The T2 increase in the PKU lesion reflects a raised concentration of free water molecules (about 15%) that have an increased trajectory between collisions compared to the same region in controls. The increase in water mobility might be explained by changes in extracellular space volume and myelin sheaths, which, presumably, have a different geometry with more hydrophobic sites in PKU patients. The changes result in increased tortuosity and may be confirmed by the loss of anisotropy in PKU lesions.

Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

Science.gov (United States)

Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

2017-10-01

In the perioperative period, anesthesiologists and postanesthesia care unit (PACU) nurses routinely prepare and administer small-volume IV injections, yet the accuracy of delivered medication volumes in this setting has not been described. In this ex vivo study, we sought to characterize the degree to which small-volume injections (≤0.5 mL) deviated from the intended injection volumes among a group of pediatric anesthesiologists and pediatric postanesthesia care unit (PACU) nurses. We hypothesized that as the intended injection volumes decreased, the deviation from those intended injection volumes would increase. Ten attending pediatric anesthesiologists and 10 pediatric PACU nurses each performed a series of 10 injections into a simulated patient IV setup. Practitioners used separate 1-mL tuberculin syringes with removable 18-gauge needles (Becton-Dickinson & Company, Franklin Lakes, NJ) to aspirate 5 different volumes (0.025, 0.05, 0.1, 0.25, and 0.5 mL) of 0.25 mM Lucifer Yellow (LY) fluorescent dye constituted in saline (Sigma Aldrich, St. Louis, MO) from a rubber-stoppered vial. Each participant then injected the specified volume of LY fluorescent dye via a 3-way stopcock into IV tubing with free-flowing 0.9% sodium chloride (10 mL/min). The injected volume of LY fluorescent dye and 0.9% sodium chloride then drained into a collection vial for laboratory analysis. Microplate fluorescence wavelength detection (Infinite M1000; Tecan, Mannedorf, Switzerland) was used to measure the fluorescence of the collected fluid. Administered injection volumes were calculated based on the fluorescence of the collected fluid using a calibration curve of known LY volumes and associated fluorescence.To determine whether deviation of the administered volumes from the intended injection volumes increased at lower injection volumes, we compared the proportional injection volume error (loge [administered volume/intended volume]) for each of the 5 injection volumes using a linear

Volume and density changes of biological fluids with temperature

Science.gov (United States)

Hinghofer-Szalkay, H.

1985-01-01

The thermal expansion of human blood, plasma, ultrafiltrate, and erythrocycte concentration at temperatures in the range of 4-48 C is studied. The mechanical oscillator technique which has an accuracy of 1 x 10 to the -5 th g/ml is utilized to measure fluid density. The relationship between thermal expansion, density, and temperature is analyzed. The study reveals that: (1) thermal expansion increases with increasing temperature; (2) the magnitude of the increase declines with increasing temperature; (3) thermal expansion increases with density at temperatures below 40 C; and (4) the thermal expansion of intracellular fluid is greater than that of extracellular fluid in the temperature range of 4-10 C, but it is equal at temperatures greater than or equal to 40 C.

Postoperative volume balance

DEFF Research Database (Denmark)

Frost, H; Mortensen, C.R.; Secher, Niels H.

2017-01-01

In healthy humans, stroke volume (SV) and cardiac output (CO) do not increase with expansion of the central blood volume by head-down tilt or administration of fluid. Here, we exposed 85 patients to Trendelenburg's position about one hour after surgery while cardiovascular variables were determin...

Chronic Use of Aspirin and Total White Matter Lesion Volume: Results from the Women's Health Initiative Memory Study of Magnetic Resonance Imaging Study.

Science.gov (United States)

Holcombe, Andrea; Ammann, Eric; Espeland, Mark A; Kelley, Brendan J; Manson, JoAnn E; Wallace, Robert; Robinson, Jennifer

2017-10-01

To investigate the relationship between aspirin and subclinical cerebrovascular heath, we evaluated the effect of chronic aspirin use on white matter lesions (WML) volume among women. Chronic aspirin use was assessed in 1365 women who participated in the Women's Health Initiative Memory Study of Magnetic Resonance Imaging. Differences in WML volumes between aspirin users and nonusers were assessed with linear mixed models. A number of secondary analyses were performed, including lobe-specific analyses, subgroup analyses based on participants' overall risk of cerebrovascular disease, and a dose-response relationship analysis. The mean age of the women at magnetic resonance imaging examination was 77.6 years. Sixty-one percent of participants were chronic aspirin users. After adjusting for demographic variables and comorbidities, chronic aspirin use was nonsignificantly associated with 4.8% (95% CI: -6.8%, 17.9%) larger WML volumes. These null findings were confirmed in secondary and sensitivity analyses, including an active comparator evaluation where aspirin users were compared to users of nonaspirin nonsteroidal anti-inflammatory drugs or acetaminophen. There was a nonsignificant difference in WML volumes between aspirin users and nonusers. Further, our results suggest that chronic aspirin use may not have a clinically significant effect on WML volumes in women. Published by Elsevier Inc.

Diffusion-weighted MR imaging of cystic lesions of neurocysticercosis: a preliminary study

International Nuclear Information System (INIS)

Raffin, Luciana S.; Bacheschi, Luiz A.; Machado, Luis R.; Nobrega, Jose P.S.; Coelho, Christina; Leite, Claudia C.

2001-01-01

Neurocysticercosis is an endemic disease in some developing countries. It has pleomorfic clinical and imaging findings, which are variable from patient to patient. In this preliminary note, we studied the magnetic resonance diffusion-weighted images of sixteen patients presenting with cystic lesions of this disease diagnosed by clinical and laboratorial findings. All the lesions had hypointense signal and the similar apparent diffusion coefficient values as the cerebrospinal fluid. (author)

Dynamic computed tomography scanning of benign bone lesions: Preliminary results

International Nuclear Information System (INIS)

Levine, E.; Neff, J.R.

1983-01-01

The majority of benign bone lesions can be evaluated adequately using conventional radiologic techniques. However, it is not always possible to differentiate reliably between different types of benign bone lesions on the basis of plain film appearances alone. Dynamic computed tomography (CT) scanning provides a means for further characterizing such lesions by assessing their degree of vascularity. Thus, it may help in distinguishing an osteoid osteoma, which has a hypervascular nidus, from a Brodie's abscess, which is avascular. Dynamic CT scanning may also help in the differentiation between a fluid-containing simple bone cyst, which is avascular, and other solid or semi-solid benign bone lesions which slow varying degrees of vascularity. However, because of the additional irradiation involved, dynamic CT scanning should be reserved for evaluation of selected patients with benign bone lesions in whom the plain film findings are not definitive and in whom the CT findings may have a significant influence on management. (orig.)

Computed Tomography-Based Imaging of Voxel-Wise Lesion Water Uptake in Ischemic Brain: Relationship Between Density and Direct Volumetry.

Science.gov (United States)

Broocks, Gabriel; Flottmann, Fabian; Ernst, Marielle; Faizy, Tobias Djamsched; Minnerup, Jens; Siemonsen, Susanne; Fiehler, Jens; Kemmling, Andre

2018-04-01

Net water uptake per volume of brain tissue may be calculated by computed tomography (CT) density, and this imaging biomarker has recently been investigated as a predictor of lesion age in acute stroke. However, the hypothesis that measurements of CT density may be used to quantify net water uptake per volume of infarct lesion has not been validated by direct volumetric measurements so far. The purpose of this study was to (1) develop a theoretical relationship between CT density reduction and net water uptake per volume of ischemic lesions and (2) confirm this relationship by quantitative in vitro and in vivo CT image analysis using direct volumetric measurements. We developed a theoretical rationale for a linear relationship between net water uptake per volume of ischemic lesions and CT attenuation. The derived relationship between water uptake and CT density was tested in vitro in a set of increasingly diluted iodine solutions with successive CT measurements. Furthermore, the consistency of this relationship was evaluated using human in vivo CT images in a retrospective multicentric cohort. In 50 edematous infarct lesions, net water uptake was determined by direct measurement of the volumetric difference between the ischemic and normal hemisphere and was correlated with net water uptake calculated by ischemic density measurements. With regard to in vitro data, water uptake by density measurement was equivalent to direct volumetric measurement (r = 0.99, P volumetry was 44.7 ± 26.8 mL and the mean percent water uptake per lesion volume was 22.7% ± 7.4%. This was equivalent to percent water uptake obtained from density measurements: 21.4% ± 6.4%. The mean difference between percent water uptake by direct volumetry and percent water uptake by CT density was -1.79% ± 3.40%, which was not significantly different from 0 (P < 0.0001). Volume of water uptake in infarct lesions can be calculated quantitatively by relative CT density measurements. Voxel-wise imaging

Fluid control structures in microfluidic devices

Science.gov (United States)

Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

2017-05-09

Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

Spinal focal lesion detection in multiple myeloma using multimodal image features

Science.gov (United States)

Fränzle, Andrea; Hillengass, Jens; Bendl, Rolf

2015-03-01

Multiple myeloma is a tumor disease in the bone marrow that affects the skeleton systemically, i.e. multiple lesions can occur in different sites in the skeleton. To quantify overall tumor mass for determining degree of disease and for analysis of therapy response, volumetry of all lesions is needed. Since the large amount of lesions in one patient impedes manual segmentation of all lesions, quantification of overall tumor volume is not possible until now. Therefore development of automatic lesion detection and segmentation methods is necessary. Since focal tumors in multiple myeloma show different characteristics in different modalities (changes in bone structure in CT images, hypointensity in T1 weighted MR images and hyperintensity in T2 weighted MR images), multimodal image analysis is necessary for the detection of focal tumors. In this paper a pattern recognition approach is presented that identifies focal lesions in lumbar vertebrae based on features from T1 and T2 weighted MR images. Image voxels within bone are classified using random forests based on plain intensities and intensity value derived features (maximum, minimum, mean, median) in a 5 x 5 neighborhood around a voxel from both T1 and T2 weighted MR images. A test data sample of lesions in 8 lumbar vertebrae from 4 multiple myeloma patients can be classified at an accuracy of 95% (using a leave-one-patient-out test). The approach provides a reasonable delineation of the example lesions. This is an important step towards automatic tumor volume quantification in multiple myeloma.

Pulmonary tissue volume, cardiac output, and diffusing capacity in sustained microgravity

Science.gov (United States)

Verbanck, S.; Larsson, H.; Linnarsson, D.; Prisk, G. K.; West, J. B.; Paiva, M.

1997-01-01

In microgravity (microG) humans have marked changes in body fluids, with a combination of an overall fluid loss and a redistribution of fluids in the cranial direction. We investigated whether interstitial pulmonary edema develops as a result of a headward fluid shift or whether pulmonary tissue fluid volume is reduced as a result of the overall loss of body fluid. We measured pulmonary tissue volume (Vti), capillary blood flow, and diffusing capacity in four subjects before, during, and after 10 days of exposure to microG during spaceflight. Measurements were made by rebreathing a gas mixture containing small amounts of acetylene, carbon monoxide, and argon. Measurements made early in flight in two subjects showed no change in Vti despite large increases in stroke volume (40%) and diffusing capacity (13%) consistent with increased pulmonary capillary blood volume. Late in-flight measurements in four subjects showed a 25% reduction in Vti compared with preflight controls (P volume, to the extent that it was no longer significantly different from preflight control. Diffusing capacity remained elevated (11%; P pulmonary perfusion and pulmonary capillary blood volume, interstitial pulmonary edema does not result from exposure to microG.

Bioimpedance spectroscopy for assessment of volume status in patients before and after general anaesthesia.

Directory of Open Access Journals (Sweden)

Matthäus Ernstbrunner

Full Text Available BACKGROUND: Technically assisted assessment of volume status before surgery may be useful to direct intraoperative fluid administration. We therefore tested a recently developed whole-body bioimpedance spectroscopy device to determine pre- to postoperative fluid distribution. METHODS: Using a three-compartment physiologic tissue model, the body composition monitor (BCM, Fresenius Medical Care, Germany measures total body fluid volume, extracellular volume, intracellular volume and fluid overload as surplus or deficit of 'normal' extracellular volume. BCM-measurements were performed before and after standardized general anaesthesia for gynaecological procedures (laparotomies, laparoscopies and vaginal surgeries. BCM results were blinded to the attending anaesthesiologist and data analysed using the 2-sided, paired Student's t-test and multiple linear regression. RESULTS: In 71 females aged 45 ± 15 years with body weight 67 ± 13 kg and Duration of anesthesia 154 ± 69 minutes [corrected] duration of anaesthesia 154 ± 68 min, pre- to postoperative fluid overload increased from -0.7 ± 1.1 L to 0.1 ± 1.0 L, corresponding to -5.1 ± 7.5% and 0.8 ± 6.7% of normal extracellular volume, respectively (both p<0.001, after patients had received 1.9 ± 0.9 L intravenous crystalloid fluid. Perioperative urinary excretion was 0.3 ± 0.2 L [corrected]. The increase in extracellular volume was paralleled by an increase in total body fluid volume, while intracellular volume increased only slightly and without reaching statistical significance (p = 0.15. Net perioperative fluid balance (administered fluid volume minus urinary excretion was significantly associated with change in extracellular volume (r(2 = 0.65, but was not associated with change in intracellular volume (r(2 = 0.01. CONCLUSIONS: Routine intraoperative fluid administration results in a significant, and clinically meaningful increase in the extracellular compartment. BCM-measurements yielded

[Extracellular fluid, plasma and interstitial volume in cirrhotic patients without clinical edema or ascites].

Science.gov (United States)

Noguera Viñas, E C; Hames, W; Mothe, G; Barrionuevo, M P

1989-01-01

Extracellular fluid volume (E.C.F.) and plasma volume (P.V.), were measured with sodium sulfate labeled with 35I and 131I human serum albumin, respectively, by the dilution technique in control subjects and in cirrhotic patients without clinical ascites or edema, renal or hepatic failure, gastrointestinal bleeding or diuretics. Results are expressed as mean +/- DS in both ml/m2 and ml/kg. In normal subjects E.C.F. (n = 8) was 7,533 +/- 817 ml/m2 (201.3 +/- 182 ml/kg), P.V. (n = 11) 1,767 +/- 337 ml/m2 (47.2 +/- 9.3 ml/kg), and interstitial fluid (I.S.F.) (n = 7) 5,758 +/- 851 ml/m2 (Table 2). In cirrhotic patients E.C.F. (n = 11) was 10,318 +/- 2,980 ml/m2 (261.7 +/- 76.8 ml/kg), P.V. (n = 12) 2,649 +/- 558 ml/m2 (67.7 +/- 15.6 ml/kg) and I.S.F. (n = 11) 7,866 +/- 2,987 ml/m2 (Table 3). Cirrhotic patients compared with normal subjects have hypervolemia due to a significant E.C.F. and P.V. expansion (p less than 0.02 and less than 0.001 respectively) (Fig. 1). Reasons for E.C.F. and P.V. abnormalities in cirrhotic patients may reflect urinary sodium retention related to portal hipertension which stimulates aldosterone release or enhanced renal tubular sensitivity to the hormone. However, it is also possible that these patients, in the presence of hypoalbuminemia (Table 1), have no clinical edema or ascites due to increased glomerular filtration, suppressed release of vasopressin, increased natriuretic factor, and urinary prostaglandin excretion, in response to the intravascular expansion, all of which increased solute and water delivery to the distal nephron and improved renal water excretion. We conclude that in our clinical experience cirrhotic patients without ascites or edema have hypervolemia because of a disturbance in E.C.F.

The effects of iterative reconstruction in CT on low-contrast liver lesion volumetry: a phantom study

Science.gov (United States)

Li, Qin; Berman, Benjamin P.; Schumacher, Justin; Liang, Yongguang; Gavrielides, Marios A.; Yang, Hao; Zhao, Binsheng; Petrick, Nicholas

2017-03-01

Tumor volume measured from computed tomography images is considered a biomarker for disease progression or treatment response. The estimation of the tumor volume depends on the imaging system parameters selected, as well as lesion characteristics. In this study, we examined how different image reconstruction methods affect the measurement of lesions in an anthropomorphic liver phantom with a non-uniform background. Iterative statistics-based and model-based reconstructions, as well as filtered back-projection, were evaluated and compared in this study. Statistics-based and filtered back-projection yielded similar estimation performance, while model-based yielded higher precision but lower accuracy in the case of small lesions. Iterative reconstructions exhibited higher signal-to-noise ratio but slightly lower contrast of the lesion relative to the background. A better understanding of lesion volumetry performance as a function of acquisition parameters and lesion characteristics can lead to its incorporation as a routine sizing tool.

Whole-lesion histogram analysis metrics of the apparent diffusion coefficient as a marker of breast lesions characterization at 1.5 T.

Science.gov (United States)

Bougias, H; Ghiatas, A; Priovolos, D; Veliou, K; Christou, A

2017-05-01

To retrospectively assess the role of whole-lesion apparent diffusion coefficient (ADC) in the characterization of breast tumors by comparing different histogram metrics. 49 patients with 53 breast lesions underwent magnetic resonance imaging (MRI). ADC histogram parameters, including the mean, mode, 10th/50th/90th percentile, skewness, kurtosis, and entropy ADCs, were derived for the whole-lesion volume in each patient. Mann-Whitney U-test, area under the receiver-operating characteristic curve (AUC) were used for statistical analysis. The mean, mode and 10th/50th/90th percentile ADC values were significantly lower in malignant lesions compared with benign ones (all P histogram analysis could be a helpful index in the characterization and differentiation between benign and malignant breast lesions with the 10th and 50th percentile ADC be the most accurate discriminators. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

Cyclops lesions detected by MRI are frequent findings after ACL surgical reconstruction but do not impact clinical outcome over 2 years

Energy Technology Data Exchange (ETDEWEB)

Facchetti, Luca [University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); University of Brescia, Department of Radiology, Brescia (Italy); Schwaiger, Benedikt J.; Gersing, Alexandra S.; Nardo, Lorenzo; Majumdar, Sharmila; Link, Thomas M.; Li, Xiaojuan [University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Guimaraes, Julio Brandao [University of California, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Federal University of Sao Paulo (UNIFESP), Department of Radiology, Sao Paulo (Brazil); Ma, Benjamin C. [University of California, Department of Orthopedic Surgery, San Francisco, CA (United States); Collaboration: UCSF-P50-ACL Consortium; AF-ACL Consortium

2017-08-15

To assess the impact of cyclops lesions with MRI in patients treated for anterior cruciate ligament (ACL) tears on clinical outcome. In 113 patients (age 29.8 ± 10.5y; 55 females; BMI 24.8 ± 3.7 kg/m{sup 2}) with complete ACL tear, 3 T-MRI scans were obtained before, 6-months, 1-year (n = 75) and 2-years (n = 33) after ACL reconstruction. Presence and volume of cyclops lesions were assessed. Clinical outcomes were measured using the Knee injury and Osteoarthritis Outcome Score (KOOS) and differences between time points (∇KOOS) were calculated. Changes of KOOS subscales were compared between patients with and without cyclops lesion. KOOS was also correlated with lesion volume. Cyclops lesions were found in 25% (28/113), 27% (20/75) and 33% (11/33) of patients after 6-months, 1- and 2-years, respectively. The lesion volume did not change significantly (P > 0.05) between time points, measuring 0.65 ± 0.59, 0.81 ± 0.70 and 0.72.9 ± 0.96 cm{sup 3}, respectively. Clinical outcomes based on KOOS subscales were not significantly different in patients with cyclops lesions compared to those without cyclops lesions (each comparison P > 0.05), and no significant associations of clinical outcomes with lesion volume were found (P > 0.05). Neither presence nor size of cyclops lesions within the first 2-years after ACL surgery were associated with inferior clinical outcome. (orig.)

2013 AAHA/AAFP fluid therapy guidelines for dogs and cats.

Science.gov (United States)

Davis, Harold; Jensen, Tracey; Johnson, Anthony; Knowles, Pamela; Meyer, Robert; Rucinsky, Renee; Shafford, Heidi

2013-01-01

Fluid therapy is important for many medical conditions in veterinary patients. The assessment of patient history, chief complaint, physical exam findings, and indicated additional testing will determine the need for fluid therapy. Fluid selection is dictated by the patient's needs, including volume, rate, fluid composition required, and location the fluid is needed (e.g., interstitial versus intravascular). Therapy must be individualized, tailored to each patient, and constantly re-evaluated and reformulated according to changes in status. Needs may vary according to the existence of either acute or chronic conditions, patient pathology (e.g., acid-base, oncotic, electrolyte abnormalities), and comorbid conditions. All patients should be assessed for three types of fluid disturbances: changes in volume, changes in content, and/or changes in distribution. The goals of these guidelines are to assist the clinician in prioritizing goals, selecting appropriate fluids and rates of administration, and assessing patient response to therapy. These guidelines provide recommendations for fluid administration for anesthetized patients and patients with fluid disturbances.

Natural convection in nano-fluids: Are the thermophoresis and Brownian motion effects significant in nano-fluid heat transfer enhancement?

International Nuclear Information System (INIS)

Haddad, Zoubida; Abu-Nada, Eiyad; Oztop, Hakan F.; Mataoui, Amina

2012-01-01

Natural convection heat transfer and fluid flow of CuO-Water nano-fluids is studied using the Rayleigh-Benard problem. A two component non-homogenous equilibrium model is used for the nano-fluid that incorporates the effects of Brownian motion and thermophoresis. Variable thermal conductivity and variable viscosity are taken into account in this work. Finite volume method is used to solve governing equations. Results are presented by streamlines, isotherms, nano-particle distribution, local and mean Nusselt numbers and nano-particle profiles at top and bottom side. Comparison of two cases as absence of Brownian and thermophoresis effects and presence of Brownian and thermophoresis effects showed that higher heat transfer is formed with the presence of Brownian and thermophoresis effect. In general, by considering the role of thermophoresis and Brownian motion, an enhancement in heat transfer is observed at any volume fraction of nano-particles. However, the enhancement is more pronounced at low volume fraction of nano-particles and the heat transfer decreases by increasing nano-particle volume fraction. On the other hand, by neglecting the role of thermophoresis and Brownian motion, deterioration in heat transfer is observed and this deterioration elevates by increasing the volume fraction of nano-particles. (authors)

Morel-Lavallee Lesion: Case Report with Review of Literature.

Science.gov (United States)

Padmanabhan, Elamparidhi; Rudrappa, Ramesh Kumar; Bhavishya, Talluri; Rajakumar, Sibhithran; Selvakkalanjiyam, Sivaranjinie

2017-07-01

Morel-Lavallee lesions are closed degloving soft tissue injuries which occur because of trauma and in which the skin and subcutaneous tissue are separated from superficial fascia. This shear trauma results in creation of a potential space filled with serosanguinous fluid, blood and necrotic fat. We discuss a case of 52-year-old female with history of trauma one week back, who presented with a boggy swelling over the postero-lateral aspect of proximal forearm and distal arm. Local examination showed fluctuating fluid collection. MRI showed variable intensity fluid collection in a potential space between the subcutaneous tissue and deep fascia in arm and forearm. Percutaneous decompression and evacuation of the collection with systemic antibiotic therapy resulted in rapid improvement.

Fluid transport in reaction induced fractures

Science.gov (United States)

Ulven, Ole Ivar; Sun, WaiChing; Malthe-Sørenssen, Anders

2015-04-01

The process of fracture formation due to a volume increasing chemical reaction has been studied in a variety of different settings, e.g. weathering of dolerites by Røyne et al. te{royne}, serpentinization and carbonation of peridotite by Rudge et al. te{rudge} and replacement reactions in silica-poor igneous rocks by Jamtveit et al. te{jamtveit}. It is generally assumed that fracture formation will increase the net permeability of the rock, and thus increase the reactant transport rate and subsequently the total rate of material conversion, as summarised by Kelemen et al. te{kelemen}. Ulven et al. te{ulven_1} have shown that for fluid-mediated processes the ratio between chemical reaction rate and fluid transport rate in bulk rock controls the fracture pattern formed, and Ulven et al. te{ulven_2} have shown that instantaneous fluid transport in fractures lead to a significant increase in the total rate of the volume expanding process. However, instantaneous fluid transport in fractures is clearly an overestimate, and achievable fluid transport rates in fractures have apparently not been studied in any detail. Fractures cutting through an entire domain might experience relatively fast advective reactant transport, whereas dead-end fractures will be limited to diffusion of reactants in the fluid, internal fluid mixing in the fracture or capillary flow into newly formed fractures. Understanding the feedback process between fracture formation and permeability changes is essential in assessing industrial scale CO2 sequestration in ultramafic rock, but little is seemingly known about how large the permeability change will be in reaction-induced fracturing. In this work, we study the feedback between fracture formation during volume expansion and fluid transport in different fracture settings. We combine a discrete element model (DEM) describing a volume expanding process and the related fracture formation with different models that describe the fluid transport in the

The Mayo Clinic experience with Morel-Lavallée lesions: establishment of a practice management guideline.

Science.gov (United States)

Nickerson, Terry P; Zielinski, Martin D; Jenkins, Donald H; Schiller, Henry J

2014-02-01

Although uncommon, Morel-Lavallée lesions (also called closed degloving injuries) are associated with considerable morbidity in trauma patients. There is lack of consensus regarding proper management of these lesions. Management options include nonoperative therapies, along with percutaneous and operative techniques. We sought to define the factors associated with failure of percutaneous aspiration to better identify patients requiring immediate operative management. We retrospectively searched our prospectively collected database for patient records containing the terms Morel-Lavallée, closed degloving injury, or posttraumatic seroma from February 2, 2004, through December 23, 2011. Treatment methods included compression wraps or observation (nonoperative management), percutaneous aspiration, or operative management with incision/drainage or formal debridement of skin and soft tissues that resulted in wound vacuum-assisted closure placement and/or split-thickness skin graft (operative management). The treatment groups were compared using univariate analysis and χ testing. We identified 79 patients with 87 Morel-Lavallée lesions in the setting of trauma. Most were caused by motor vehicle collisions (25%). No difference was observed between the treatment groups in sex, body mass index, anticoagulation treatment, diabetes mellitus, smoking history, or alcohol use. The percutaneous aspiration group had higher rates of recurrence (56% vs. 19% and 15% in nonoperative and operative groups, respectively). The percentage of patients who had aspiration of more than 50 mL of fluid was higher for lesions that recurred than for lesions that resolved (83% vs. 33%, p = 0.02). Aspiration of more than 50 mL of fluid from Morel-Lavallée lesions was much more common among lesions that recurred (83%) than among those that resolved (33%). We therefore recommend that aspiration of more than 50 mL of fluid from a Morel-Lavallée lesion prompts operative intervention. We have now

AqSo_NaCl: Computer program to calculate p-T-V-x properties in the H2O-NaCl fluid system applied to fluid inclusion research and pore fluid calculation

Science.gov (United States)

Bakker, Ronald J.

2018-06-01

The program AqSo_NaCl has been developed to calculate pressure - molar volume - temperature - composition (p-V-T-x) properties, enthalpy, and heat capacity of the binary H2O-NaCl system. The algorithms are designed in BASIC within the Xojo programming environment, and can be operated as stand-alone project with Macintosh-, Windows-, and Unix-based operating systems. A series of ten self-instructive interfaces (modules) are developed to calculate fluid inclusion properties and pore fluid properties. The modules may be used to calculate properties of pure NaCl, the halite-liquidus, the halite-vapourus, dew-point and bubble-point curves (liquid-vapour), critical point, and SLV solid-liquid-vapour curves at temperatures above 0.1 °C (with halite) and below 0.1 °C (with ice or hydrohalite). Isochores of homogeneous fluids and unmixed fluids in a closed system can be calculated and exported to a.txt file. Isochores calculated for fluid inclusions can be corrected according to the volumetric properties of quartz. Microthermometric data, i.e. dissolution temperatures and homogenization temperatures, can be used to calculated bulk fluid properties of fluid inclusions. Alternatively, in the absence of total homogenization temperature the volume fraction of the liquid phase in fluid inclusions can be used to obtain bulk properties.

Non-Invasive Electromagnetic Skin Patch Sensor to Measure Intracranial Fluid–Volume Shifts

Directory of Open Access Journals (Sweden)

Jacob Griffith

2018-03-01

Full Text Available Elevated intracranial fluid volume can drive intracranial pressure increases, which can potentially result in numerous neurological complications or death. This study’s focus was to develop a passive skin patch sensor for the head that would non-invasively measure cranial fluid volume shifts. The sensor consists of a single baseline component configured into a rectangular planar spiral with a self-resonant frequency response when impinged upon by external radio frequency sweeps. Fluid volume changes (10 mL increments were detected through cranial bone using the sensor on a dry human skull model. Preliminary human tests utilized two sensors to determine feasibility of detecting fluid volume shifts in the complex environment of the human body. The correlation between fluid volume changes and shifts in the first resonance frequency using the dry human skull was classified as a second order polynomial with R2 = 0.97. During preliminary and secondary human tests, a ≈24 MHz and an average of ≈45.07 MHz shifts in the principal resonant frequency were measured respectively, corresponding to the induced cephalad bio-fluid shifts. This electromagnetic resonant sensor may provide a non-invasive method to monitor shifts in fluid volume and assist with medical scenarios including stroke, cerebral hemorrhage, concussion, or monitoring intracranial pressure.

Impact of irrigation flow rate and intrapericardial fluid on cooled-tip epicardial radiofrequency ablation.

Science.gov (United States)

Aryana, Arash; O'Neill, Padraig Gearoid; Pujara, Deep K; Singh, Steve K; Bowers, Mark R; Allen, Shelley L; d'Avila, André

2016-08-01

The optimal irrigation flow rate (IFR) during epicardial radiofrequency (RF) ablation has not been established. This study specifically examined the impact of IFR and intrapericardial fluid (IPF) accumulation during epicardial RF ablation. Altogether, 452 ex vivo RF applications (10 g for 60 seconds) delivered to the epicardial surface of bovine myocardium using 3 open-irrigated ablation catheters (ThermoCool SmartTouch, ThermoCool SmartTouch-SF, and FlexAbility) and 50 in vivo RF applications delivered (ThermoCool SmartTouch-SF) in 4 healthy adult swine in the presence or absence of IPF were examined. Ex vivo, RF was delivered at low (≤3 mL/min), reduced (5-7 mL/min), and high (≥10 mL/min) IFRs using intermediate (25-35 W) and high (35-45 W) power. In vivo, applications were delivered (at 9.3 ± 2.2 g for 60 seconds at 39 W) using reduced (5 mL/min) and high (15 mL/min) IFRs. Ex vivo, surface lesion diameter inversely correlated with IFR, whereas maximum lesion diameter and depth did not differ. While steam pops occurred more frequently at low IFR using high power (ThermoCool SmartTouch and ThermoCool SmartTouch-SF), tissue disruption was rare and did not vary with IFR. In vivo, charring/steam pop was not detected. Although there were no discernible differences in lesion size with IFR, surface lesion diameter, maximum diameter, depth, and volume were all smaller in the presence of IPF at both IFRs. Cooled-tip epicardial RF ablation created using reduced IFRs (5-7 mL/min) yields lesion sizes similar to those created using high IFRs (≥10 mL/min) without an increase in steam pop/tissue disruption, whereas the presence of IPF significantly reduces the lesion size. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Brain volumes predict neurodevelopment in adolescents after surgery for congenital heart disease.

Science.gov (United States)

von Rhein, Michael; Buchmann, Andreas; Hagmann, Cornelia; Huber, Reto; Klaver, Peter; Knirsch, Walter; Latal, Beatrice

2014-01-01

Patients with complex congenital heart disease are at risk for neurodevelopmental impairments. Evidence suggests that brain maturation can be delayed and pre- and postoperative brain injury may occur, and there is limited information on the long-term effect of congenital heart disease on brain development and function in adolescent patients. At a mean age of 13.8 years, 39 adolescent survivors of childhood cardiopulmonary bypass surgery with no structural brain lesions evident through conventional cerebral magnetic resonance imaging and 32 healthy control subjects underwent extensive neurodevelopmental assessment and cerebral magnetic resonance imaging. Cerebral scans were analysed quantitatively using surface-based and voxel-based morphometry. Compared with control subjects, patients had lower total brain (P = 0.003), white matter (P = 0.004) and cortical grey matter (P = 0.005) volumes, whereas cerebrospinal fluid volumes were not different. Regional brain volume reduction ranged from 5.3% (cortical grey matter) to 11% (corpus callosum). Adolescents with cyanotic heart disease showed more brain volume loss than those with acyanotic heart disease, particularly in the white matter, thalami, hippocampi and corpus callosum (all P-values Brain volume reduction correlated significantly with cognitive, motor and executive functions (grey matter: P < 0.05, white matter: P < 0.01). Our findings suggest that there are long-lasting cerebral changes in adolescent survivors of cardiopulmonary bypass surgery for congenital heart disease and that these changes are associated with functional outcome.

Fluid Shifts

Science.gov (United States)

Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.;

Method and apparatus for preventing agglomeration within fluid hydrocarbons

International Nuclear Information System (INIS)

Woodbridge, D.D.

1979-01-01

This invention relates to a process for treating a fluid hydrocarbon fuel for retarding the agglomeration between particles thereof and for retarding the growth of bacteria and fungi therein. The process includes that steps of transporting a plurality of unit volumes of said fluid hydrocarbon fuel through an irradiating location and irradiating each unit of the plurality of unit volumes at the irradiating location with either neutron or gamma radiation. An apparatus for treating the fluid hydrocarbon fuels with the nuclear radiation also is provided. The apparatus includes a generally conical central irradiating cavity which is surrounded by a spiral outer irradiating cavity. The fluid hydrocarbon fuel is transported through the cavities while being irradiated by the nuclear radiation

Significance of localization of nonpalpable breast lesions

Energy Technology Data Exchange (ETDEWEB)

Oh, Ki Keun; Choi, Hyun Ju [Yongdong Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

1990-12-15

As mammography has become more popular for the evaluation of breast symptoms and for the screening of asymptomatic women, the smaller lesions are being detected before they become palpable, therefore preoperative localization became necessary. This has led to the development of several methods for preoperative localization of nonpalpable lesions. Authors analyzed 50 cases with preoperative localization in 45 patients which had abnormal findings on film mammogram or ultrasonomammogram since October 1985 through March 1990 at Yongdong Severance Hospital, College of Medicine, Yonsei University. The results were as follows: 1. Techniques of localization were spot method in 8 cases, conventional needle localization method in 38 cases and Kopan's needle localization method in 4 cases. 2. The most common mammographic indication for localization was focal calcifications in 29 cases(58%), which was followed by a newly developed mass in 25 cases(50%). 3. Outcome of pathologically confirmed diagnosis put into benign lesions in 37 cases(74%) and malignant lesions in 13 cases(26%). 4. Among the cases with localization of lesions which has suggested as benign lesions in film and ultrasonomammogram,all cases(100%) were confirmed in benign lesions pathologically. Among the cases with localization of lesions which has suggested as malignant lesions in film and ultrasonomammogram, pathologic malignant has been proved of 44% and possible histopathologic precursor of malignant was resulted in 25% such as atypical hyperplasia and adenosis. Conclusively, authors consider that the abnormal areas should be removed in their entirety with the sacrifice of minimum volume of contiguous normal breast tissue through the preoperative localization, hence our preoperative localization has contributed favorable prognosis based on material lesions in early stage breast cancer.

Significance of localization of nonpalpable breast lesions

International Nuclear Information System (INIS)

Oh, Ki Keun; Choi, Hyun Ju

1990-01-01

As mammography has become more popular for the evaluation of breast symptoms and for the screening of asymptomatic women, the smaller lesions are being detected before they become palpable, therefore preoperative localization became necessary. This has led to the development of several methods for preoperative localization of nonpalpable lesions. Authors analyzed 50 cases with preoperative localization in 45 patients which had abnormal findings on film mammogram or ultrasonomammogram since October 1985 through March 1990 at Yongdong Severance Hospital, College of Medicine, Yonsei University. The results were as follows: 1. Techniques of localization were spot method in 8 cases, conventional needle localization method in 38 cases and Kopan's needle localization method in 4 cases. 2. The most common mammographic indication for localization was focal calcifications in 29 cases(58%), which was followed by a newly developed mass in 25 cases(50%). 3. Outcome of pathologically confirmed diagnosis put into benign lesions in 37 cases(74%) and malignant lesions in 13 cases(26%). 4. Among the cases with localization of lesions which has suggested as benign lesions in film and ultrasonomammogram,all cases(100%) were confirmed in benign lesions pathologically. Among the cases with localization of lesions which has suggested as malignant lesions in film and ultrasonomammogram, pathologic malignant has been proved of 44% and possible histopathologic precursor of malignant was resulted in 25% such as atypical hyperplasia and adenosis. Conclusively, authors consider that the abnormal areas should be removed in their entirety with the sacrifice of minimum volume of contiguous normal breast tissue through the preoperative localization, hence our preoperative localization has contributed favorable prognosis based on material lesions in early stage breast cancer

The loss-of-function disease-mutation G301R in the Na+/K+-ATPase α2 isoform decreases lesion volume and improves functional outcome after acute spinal cord injury in mice

DEFF Research Database (Denmark)

Ellman, Ditte; Isaksen, Toke Jost; Lund, Minna

2017-01-01

BACKGROUND: The Na(+)/K(+)-ATPases are transmembrane ion pumps important for maintenance of ion gradients across the plasma membrane that serve to support multiple cellular functions, such as membrane potentials, regulation of cellular volume and pH, and co-transport of signaling transmitters...... lesion volume compared to littermate controls (α 2(+/+) ) 7 days after SCI. The protein level of the α1 isoform was significantly increased, in contrast to the α3 isoform that significantly decreased 3 days after SCI in both α 2(+/G301R) and α 2(+/+) mice. The level of the α2 isoform was significantly...... as no apparent differences were observed in location and activation of CD45 and F4/80 positive microglia and infiltrating leukocytes. CONCLUSION: Our proof of concept study demonstrates that reduced expression of the α2 isoform in the spinal cord is protective following SCI. Importantly, the BMS and lesion...

Multiphasic perfusion CT in acute middle cerebral artery ischemic stroke: prediction of final infarct volume and correlation with clinical outcome

International Nuclear Information System (INIS)

Yi, Chin A; Na, Dong Gyu; Ryoo, Jae Wook; Moon, Chan Hong; Byun, Hong Sik; Roh, Hong Gee; Moon, Won Jin; Lee, Kwang Ho; Lee, Soo Joo

2002-01-01

To assess the utility of multiphasic perfusion CT in the prediction of final infarct volume, and the relationship between lesion volume revealed by CT imaging and clinical outcome in acute ischemic stroke patients who have not undergone thrombolytic therapy. Thirty-five patients underwent multiphasic perfusion CT within six hours of stroke onset. After baseline unenhanced helical CT scanning, contrast-enhanced CT scans were obtained 20, 34, 48, and 62 secs after the injection of 90 mL contrast medium at a rate of 3 mL/sec. CT peak and total perfusion maps were obtained from serial CT images, and the initial lesion volumes revealed by CT were compared with final infarct volumes and clinical scores. Overall, the lesion volumes seen on CT peak perfusion maps correlated most strongly with final infarct volumes (R2=0.819, p<0.001, slope of regression line=1.016), but individual data showed that they were less than final infarct volume in 31.4% of patients. In those who showed early clinical improvement (n=6), final infarct volume tended to be overestimated by CT peak perfusion mapping and only on total perfusion maps was there significant correlation between lesion volume and final infarct volume (R2=0.854, p=0.008). The lesion volumes depicted by CT maps showed moderate correlation with baseline clinical scores and clinical outcomes (R=0.445-0.706, p≤0.007). CT peak perfusion maps demonstrate strong correlation between lesion volume and final infarct volume, and accurately predict final infarct volume in about two-thirds of the 35 patients. The lesion volume seen on CT maps shows moderate correlation with clinical outcome

Endoscopic surgical management of a large Morel-Lavallée lesion.

Science.gov (United States)

Walls, Andrew; McMahon, Samuel E; MacDonald, Jonathan; Bunn, Jonathan

2017-09-23

The Morel-Lavallée lesion is a closed degloving injury that usually occurs following high-energy trauma. We present a case demonstrating endoscopic management of this lesion. A 44-year-old man fell from scaffolding. Initial assessment demonstrated no significant injury. An ultrasound scan 2 days post injury revealed a large fluid collection along the lateral right thigh. This subsequently became infected and did not respond to antibiotic therapy.Due to the extent of the lesion, we were reluctant to perform a traditional open drainage. An endoscopic probe was inserted at the proximal and distal poles of the lesion and the wound debrided.This resulted in a rapid improvement in symptoms and a complete resolution of the lesion at 1 year postsurgery, with no wound-associated morbidity.This is only the second description of endoscopic debridement of a large, acute Morel-Lavallée lesion, with an excellent outcome. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Conceptual elaboration versus direct lexical access in WAIS-similarities: differential effects of white-matter lesions and gray matter volumes.

Science.gov (United States)

Fernaeus, Sven-Erik; Hellström, Åke

2017-09-18

Wechsler Adult Intelligence Scale (WAIS) subscale Similarities have been classified as a test of either verbal comprehension or of inductive reasoning. The reason may be that items divide into two categories. We tested the hypothesis of heterogeneity of items in WAIS-Similarities. Consecutive patients at a memory clinic and healthy controls participated in the study. White-matter hyperintensities (WMHs) and normalized temporal lobe volumes were measured based on Magnetic resonance Imaging (MRI), and tests of verbal memory and attention were used in addition to WAIS-Similarities to collect behavioural data. Factor analysis supported the hypothesis that two factors are involved in the performance of WAIS-similarities: (1) semiautomatic lexical access and (2) conceptual elaboration. These factors were highly correlated but provided discriminative diagnostic information: In logistic regression analyses, scores of the lexical access factor and of the conceptual elaboration factor discriminated patients with mild cognitive impairment from Alzheimer's disease patients and from healthy controls, respectively. High scores of WMH, indicating periventricular white-matter lesions, predicted factor scores of direct lexical access but not those of conceptual elaboration, which were predicted only by medial and lateral temporal lobe volumes.

Hydroxyethyl starch 130/0.4 versus modified fluid gelatin for volume expansion in cardiac surgery patients: the effects on perioperative bleeding and transfusion needs

NARCIS (Netherlands)

van der Linden, Philippe J.; de Hert, Stefan G.; Deraedt, Dirk; Cromheecke, Stefanie; de Decker, Koen; de Paep, Rudi; Rodrigus, Inez; Daper, Anne; Trenchant, Anne

2005-01-01

In this prospective, randomized, open controlled study we compared the effects on net red blood cell loss of 6% hydroxyethyl starch 130/0.4 (HES: n = 64) and 3% modified fluid gelatin (GEL: n = 68) administered for intravascular volume management in patients undergoing coronary surgery. Blood losses

Optimization of MR fluid Yield stress using Taguchi Method and Response Surface Methodology Techniques

Science.gov (United States)

Mangal, S. K.; Sharma, Vivek

2018-02-01

Magneto rheological fluids belong to a class of smart materials whose rheological characteristics such as yield stress, viscosity etc. changes in the presence of applied magnetic field. In this paper, optimization of MR fluid constituents is obtained with on-state yield stress as response parameter. For this, 18 samples of MR fluids are prepared using L-18 Orthogonal Array. These samples are experimentally tested on a developed & fabricated electromagnet setup. It has been found that the yield stress of MR fluid mainly depends on the volume fraction of the iron particles and type of carrier fluid used in it. The optimal combination of the input parameters for the fluid are found to be as Mineral oil with a volume percentage of 67%, iron powder of 300 mesh size with a volume percentage of 32%, oleic acid with a volume percentage of 0.5% and tetra-methyl-ammonium-hydroxide with a volume percentage of 0.7%. This optimal combination of input parameters has given the on-state yield stress as 48.197 kPa numerically. An experimental confirmation test on the optimized MR fluid sample has been then carried out and the response parameter thus obtained has found matching quite well (less than 1% error) with the numerically obtained values.

Large deep neural networks for MS lesion segmentation

Science.gov (United States)

Prieto, Juan C.; Cavallari, Michele; Palotai, Miklos; Morales Pinzon, Alfredo; Egorova, Svetlana; Styner, Martin; Guttmann, Charles R. G.

2017-02-01

Multiple sclerosis (MS) is a multi-factorial autoimmune disorder, characterized by spatial and temporal dissemination of brain lesions that are visible in T2-weighted and Proton Density (PD) MRI. Assessment of lesion burden and is useful for monitoring the course of the disease, and assessing correlates of clinical outcomes. Although there are established semi-automated methods to measure lesion volume, most of them require human interaction and editing, which are time consuming and limits the ability to analyze large sets of data with high accuracy. The primary objective of this work is to improve existing segmentation algorithms and accelerate the time consuming operation of identifying and validating MS lesions. In this paper, a Deep Neural Network for MS Lesion Segmentation is implemented. The MS lesion samples are extracted from the Partners Comprehensive Longitudinal Investigation of Multiple Sclerosis (CLIMB) study. A set of 900 subjects with T2, PD and a manually corrected label map images were used to train a Deep Neural Network and identify MS lesions. Initial tests using this network achieved a 90% accuracy rate. A secondary goal was to enable this data repository for big data analysis by using this algorithm to segment the remaining cases available in the CLIMB repository.

Unsteady force estimation using a Lagrangian drift-volume approach

Science.gov (United States)

McPhaden, Cameron J.; Rival, David E.

2018-04-01

A novel Lagrangian force estimation technique for unsteady fluid flows has been developed, using the concept of a Darwinian drift volume to measure unsteady forces on accelerating bodies. The construct of added mass in viscous flows, calculated from a series of drift volumes, is used to calculate the reaction force on an accelerating circular flat plate, containing highly-separated, vortical flow. The net displacement of fluid contained within the drift volumes is, through Darwin's drift-volume added-mass proposition, equal to the added mass of the plate and provides the reaction force of the fluid on the body. The resultant unsteady force estimates from the proposed technique are shown to align with the measured drag force associated with a rapid acceleration. The critical aspects of understanding unsteady flows, relating to peak and time-resolved forces, often lie within the acceleration phase of the motions, which are well-captured by the drift-volume approach. Therefore, this Lagrangian added-mass estimation technique opens the door to fluid-dynamic analyses in areas that, until now, were inaccessible by conventional means.

Review of a fluid resuscitation protocol: "fluid creep" is not due to nursing error.

Science.gov (United States)

Faraklas, Iris; Cochran, Amalia; Saffle, Jeffrey

2012-01-01

Recent reviews of burn resuscitation have included the suggestion that "fluid creep" may be influenced by practitioner error. Our center uses a nursing-driven resuscitation protocol that permits titration of fluid based on hourly urine output, including the addition of colloid when patients fail to respond appropriately. The purpose of this study was to examine protocol compliance. We reviewed 140 patients (26 children) with burns of ≥20% TBSA who received protocol-directed resuscitation from 2005 to 2010. We compared each patient's actual hourly fluid infusion with that predicted by the protocol. Sixty-seven patients (48%) completed resuscitation using crystalloid alone, whereas 73 patients required colloid supplementation. Groups did not differ in age, gender, weight, or time from injury to admission. Patients requiring colloid had larger median total burns (33.0 vs 23.5% TBSA) and full-thickness burns (15.5 vs 4.5% TBSA) and more inhalation injuries (60.3 vs 28.4%; P patients had median predicted requirements of 5.4 ml/kg/%TBSA. Crystalloid-only patients required fluid volumes close to Parkland predictions (4.7 ml/kg/%TBSA), whereas patients who received colloid required more fluid than the predicted volume (7.5 ml/kg/%TBSA). However, the hourly difference between the predicted and received fluids was a median of only 1.0% (interquartile range: -6.1 to 11.1%) and did not differ between groups. Pediatric patients had greater calculated differences than adults. Crystalloid patients exhibited higher urine outputs than colloid patients until colloid was started, suggesting that early over-resuscitation did not contribute to fluid creep. Adherence to our protocol for burn shock resuscitation was excellent overall. Fluid creep exhibited by more seriously injured patients was not due to nurses' failure to follow the protocol. This review has illuminated some opportunities for practice improvement, possibly using a computerized decision support system.

Neonatal deep white matter venous infarction and liquefaction: a pseudo-abscess lesion

International Nuclear Information System (INIS)

Ruess, Lynne; Rusin, Jerome A.; Dent, Carly M.; Tiarks, Hailey J.; Yoshida, Michelle A.

2014-01-01

Deep white matter hemorrhagic venous infarction with subsequent cavitation due to necrosis and liquefaction has been described in neonates and may be associated with infection and meningitis. In our experience, the MRI pattern of these lesions is confused with the pattern seen with cerebral abscesses. The purpose of our study was to characterize the MRI findings of post infarction necrosis and liquefaction after hemorrhagic deep white matter venous infarction in infants and to distinguish these lesions from cerebral abscesses. An institutional review board approved a retrospective review of imaging records to identify all patients with cerebral venous infarction at a children's hospital during a 10-year period. Nine infants had deep white matter hemorrhagic venous infarction with white matter fluid signal cavitary lesions. A diagnosis of cerebral abscess was considered in all. The imaging and laboratory findings in these patients are reviewed and compared to descriptions of abscesses found in the literature. There were six female and three male infants. The mean age at presentation was 20 days (range: 0-90 days), while the corrected age at presentation was less than 30 days for all patients. Seven patients presented with seizures and signs of infection; one infant presented with lethargy and later proved to have protein C deficiency. MRI was performed 0-12 days from presentation in these eight patients. Another patient with known protein C deficiency underwent MRI at 30 days for follow-up of screening US abnormalities. There were a total of 38 deep cerebral white matter fluid signal cavitary lesions: 25 frontal, 9 parietal, 2 temporal, 2 occipital. Larger lesions had dependent debris. All lesions had associated hemorrhage and many lesions had evidence of adjacent small vessel venous thrombosis. Lesions imaged after gadolinium showed peripheral enhancement. Three lesions increased in size on follow-up imaging. Three patients, two with meningitis confirmed via

Neonatal deep white matter venous infarction and liquefaction: a pseudo-abscess lesion

Energy Technology Data Exchange (ETDEWEB)

Ruess, Lynne; Rusin, Jerome A. [Nationwide Children' s Hospital, Department of Radiology, Columbus, OH (United States); The Ohio State University College of Medicine and Public Health, Columbus, OH (United States); Dent, Carly M.; Tiarks, Hailey J.; Yoshida, Michelle A. [Nationwide Children' s Hospital, Department of Radiology, Columbus, OH (United States)

2014-11-15

Deep white matter hemorrhagic venous infarction with subsequent cavitation due to necrosis and liquefaction has been described in neonates and may be associated with infection and meningitis. In our experience, the MRI pattern of these lesions is confused with the pattern seen with cerebral abscesses. The purpose of our study was to characterize the MRI findings of post infarction necrosis and liquefaction after hemorrhagic deep white matter venous infarction in infants and to distinguish these lesions from cerebral abscesses. An institutional review board approved a retrospective review of imaging records to identify all patients with cerebral venous infarction at a children's hospital during a 10-year period. Nine infants had deep white matter hemorrhagic venous infarction with white matter fluid signal cavitary lesions. A diagnosis of cerebral abscess was considered in all. The imaging and laboratory findings in these patients are reviewed and compared to descriptions of abscesses found in the literature. There were six female and three male infants. The mean age at presentation was 20 days (range: 0-90 days), while the corrected age at presentation was less than 30 days for all patients. Seven patients presented with seizures and signs of infection; one infant presented with lethargy and later proved to have protein C deficiency. MRI was performed 0-12 days from presentation in these eight patients. Another patient with known protein C deficiency underwent MRI at 30 days for follow-up of screening US abnormalities. There were a total of 38 deep cerebral white matter fluid signal cavitary lesions: 25 frontal, 9 parietal, 2 temporal, 2 occipital. Larger lesions had dependent debris. All lesions had associated hemorrhage and many lesions had evidence of adjacent small vessel venous thrombosis. Lesions imaged after gadolinium showed peripheral enhancement. Three lesions increased in size on follow-up imaging. Three patients, two with meningitis confirmed via

Analysis and Testing of Chain Characteristics and Rheological Properties for Magnetorheological Fluid

Directory of Open Access Journals (Sweden)

Song Chen

2013-01-01

Full Text Available Digital holographic microscopy is presented in this study, which can measure the magnetorheological (MR fluid in different volume fractions of particles and different magnetic field strengths. Based on the chain structure of magnetic particle under applied magnetic field, the relationships between shear yield stress, magnetic field, size, and volume fraction of MR fluid in two parallel discs are established. In this experiment, we choose three MR fluid samples to check the rheological properties of MR fluid and to obtain the material parameters with the test equipment of MR fluid; the conclusion is effective.

CT evaluation of cavitary lung lesions: focused on lung cancer, tuberculosis and abscess

International Nuclear Information System (INIS)

Lee, Young Rahn; Kim, Myung Gyu; Kang, Eun Young; Suh, Won Hyuck

1992-01-01

Differential diagnosis of cavitary lung lesions is frequently problematic. We studied 35 patients with cavitary lung lesions, consisting of lung cancer (17 patients), pulmonary tuberculosis (11 patients), and lung abscess (7 patients). We analysed CT scans in terms of irregularities of the cavity wall, maximum wall thickness, the presence of air-fluid level, location of the cavity within the mass, number of cavities within the mass, size of the cavity and the presence of calcification within the mass. Cancer cavity showed irregular inner (100%) and outer margins (100%), and thick wall (mean, 1.94 cm), eccentrical location (94%) and multiplicity within a mass (38%). Tuberculous cavity showed smooth inner (56%) and irregular outer margins (75%), thin wall (mean 0.96 cm), central location (62%), and multiplicity in one patient (36%). Abscess cavity showed irregular inner (57%) and outer margins (91%), relatively thin wall (mean 1.0 cm), central location (57%), and air-fluid level (86%). CT scan could differentiate malignant lesions from benign condition such as tuberculosis and lung abscess by observing characteristics of the cavities

CT evaluation of cavitary lung lesions: focused on lung cancer, tuberculosis and abscess

Energy Technology Data Exchange (ETDEWEB)

Lee, Young Rahn; Kim, Myung Gyu; Kang, Eun Young; Suh, Won Hyuck [College of Medicine, Korea University, Seoul (Korea, Republic of)

1992-11-15

Differential diagnosis of cavitary lung lesions is frequently problematic. We studied 35 patients with cavitary lung lesions, consisting of lung cancer (17 patients), pulmonary tuberculosis (11 patients), and lung abscess (7 patients). We analysed CT scans in terms of irregularities of the cavity wall, maximum wall thickness, the presence of air-fluid level, location of the cavity within the mass, number of cavities within the mass, size of the cavity and the presence of calcification within the mass. Cancer cavity showed irregular inner (100%) and outer margins (100%), and thick wall (mean, 1.94 cm), eccentrical location (94%) and multiplicity within a mass (38%). Tuberculous cavity showed smooth inner (56%) and irregular outer margins (75%), thin wall (mean 0.96 cm), central location (62%), and multiplicity in one patient (36%). Abscess cavity showed irregular inner (57%) and outer margins (91%), relatively thin wall (mean 1.0 cm), central location (57%), and air-fluid level (86%). CT scan could differentiate malignant lesions from benign condition such as tuberculosis and lung abscess by observing characteristics of the cavities.

Resistance exercise-induced fluid shifts: change in active muscle size and plasma volume

Science.gov (United States)

Ploutz-Snyder, L. L.; Convertino, V. A.; Dudley, G. A.

1995-01-01

The purpose of this study was to test the hypothesis that the reduction in plasma volume (PV) induced by resistance exercise reflects fluid loss to the extravascular space and subsequently selective increase in cross-sectional area (CSA) of active but not inactive skeletal muscle. We compared changes in active and inactive muscle CSA and PV after barbell squat exercise. Magnetic resonance imaging (MRI) was used to quantify muscle involvement in exercise and to determine CSA of muscle groups or individual muscles [vasti (VS), adductor (Add), hamstring (Ham), and rectus femoris (RF)]. Muscle involvement in exercise was determined using exercise-induced contrast shift in spin-spin relaxation time (T2)-weighted MR images immediately postexercise. Alterations in muscle size were based on the mean CSA of individual slices. Hematocrit, hemoglobin, and Evans blue dye were used to estimate changes in PV. Muscle CSA and PV data were obtained preexercise and immediately postexercise and 15 and 45 min thereafter. A hierarchy of muscle involvement in exercise was found such that VS > Add > Ham > RF, with the Ham and RF showing essentially no involvement. CSA of the VS and Add muscle groups were increased 10 and 5%, respectively, immediately after exercise in each thigh with no changes in Ham and RF CSA. PV was decreased 22% immediately following exercise. The absolute loss of PV was correlated (r2 = 0.75) with absolute increase in muscle CSA immediately postexercise, supporting the notion that increased muscle size after resistance exercise reflects primarily fluid movement from the vascular space into active but not inactive muscle.

Physics through the 1990s: Plasmas and fluids

International Nuclear Information System (INIS)

1986-01-01

This survey of plasma physics and fluid physics briefly describes present activities and recent major accomplishments. It also identifies research areas that are likely to lead to advances during the next decade. Plasma physics is divided into three major areas: general plasma physics, fusion plasma confinement and heating, and space and astrophysical plasmas. Fluid physics is treated as one topic, although it is an extremely diverse research field ranging from biological fluid dynamics to ship and aircraft performance to geological fluid dynamics. Subpanels, chosen for their technical expertise and scientific breadth, reviewed each of the four areas. The entire survey was coordinated and supervised by an Executive Committee, which is also responsible for the Executive Summary of this volume. Wherever possible, input from recent Advisory Committees was used, e.g., from the Magnetic Fusion Advisory Committee, the Space Science Board, and the Astronomy Survey Committee. This volume is organized as follows: An Introduction and Executive Summary that outlines (1) major findings and recommendations; (2) significant research accomplishments during the past decade and likely areas of future research emphasis; and (3) a brief summary of present funding levels, manpower resources, and institutional involvement; and the subpanel reports constitute Fluid Physics, General Plasma Physics, Fusion Plasma Confinement and Heating, and Space and Astrophysical Plasmas. An important conclusion of this survey is that both plasma physics and fluid physics are scientifically and intellectually well developed, and both ares are broad subdisciplines of physics. We therefore recommend that future physics surveys have separate volumes on the physics of plasmas and the physics of fluids

Brain lesion correlates of fatigue in individuals with traumatic brain injury.

Science.gov (United States)

Schönberger, Michael; Reutens, David; Beare, Richard; O'Sullivan, Richard; Rajaratnam, Shantha M W; Ponsford, Jennie

2017-10-01

The purpose of this study was to investigate the neurological correlates of both subjective fatigue as well as objective fatigability in individuals with traumatic brain injury (TBI). The study has a cross-sectional design. Participants (N = 53) with TBI (77% male, mean age at injury 38 years, mean time since injury 1.8 years) underwent a structural magnetic resonance imaging (MRI) scan and completed the Fatigue Severity Scale (FSS), while a subsample (N = 36) was also tested with a vigilance task. While subjective fatigue (FSS) was not related to measures of brain lesions, multilevel analyses showed that a change in the participants' decision time was significantly predicted by grey matter (GM) lesions in the right frontal lobe. The time-dependent development of the participants' error rate was predicted by total brain white matter (WM) lesion volumes, as well as right temporal GM and WM lesion volumes. These findings could be explained by decreased functional connectivity of attentional networks, which results in accelerated exhaustion during cognitive task performance. The disparate nature of objectively measurable fatigability on the one hand and the subjective experience of fatigue on the other needs further investigation.

Postmortem verification of MS cortical lesion detection with 3D DIR

NARCIS (Netherlands)

Seewann, A.M.; Kooi, E.J.; Roosendaal, S.D.; Pouwels, P.J.W.; Wattjes, M.P.; van der Valk, P.; Barkhof, F.; Polman, C.H.; Geurts, J.J.G.

2012-01-01

Objective: To assess the sensitivity and specificity of 3D double inversion recovery (DIR) MRI for detecting multiple sclerosis (MS) cortical lesions (CLs) using a direct postmortem MRI to histopathology comparison. Methods: Single-slab 3D DIR and 3D fluid-attenuated inversion recovery (FLAIR)

The development of an MRI lesion quantifying system for multiple sclerosis patients undergoing treatment

Science.gov (United States)

Moin, Paymann; Ma, Kevin; Amezcua, Lilyana; Gertych, Arkadiusz; Liu, Brent

2009-02-01

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that affects approximately 2.5 million people worldwide. Magnetic resonance imaging (MRI) is an established tool for the assessment of disease activity, progression and response to treatment. The progression of the disease is variable and requires routine follow-up imaging studies. Currently, MRI quantification of multiple sclerosis requires a manual approach to lesion measurement and yields an estimate of lesion volume and interval change. In the setting of several prior studies and a long treatment history, trends related to treatment change quickly become difficult to extrapolate. Our efforts seek to develop an imaging informatics based MS lesion computer aided detection (CAD) package to quantify and track MS lesions including lesion load, volume, and location. Together, with select clinical parameters, this data will be incorporated into an MS specific e- Folder to provide decision support to evaluate and assess treatment options for MS in a manner tailored specifically to an individual based on trends in MS presentation and progression.

Acute stroke: automatic perfusion lesion outlining using level sets.

Science.gov (United States)

Mouridsen, Kim; Nagenthiraja, Kartheeban; Jónsdóttir, Kristjana Ýr; Ribe, Lars R; Neumann, Anders B; Hjort, Niels; Østergaard, Leif

2013-11-01

To develop a user-independent algorithm for the delineation of hypoperfused tissue on perfusion-weighted images and evaluate its performance relative to a standard threshold method in simulated data, as well as in acute stroke patients. The study was approved by the local ethics committee, and patients gave written informed consent prior to their inclusion in the study. The algorithm identifies hypoperfused tissue in mean transit time maps by simultaneously minimizing the mean square error between individual and mean perfusion values inside and outside a smooth boundary. In 14 acute stroke patients, volumetric agreement between automated outlines and manual outlines determined in consensus among four neuroradiologists was assessed with Bland-Altman analysis, while spatial agreement was quantified by using lesion overlap relative to mean lesion volume (Dice coefficient). Performance improvement relative to a standard threshold approach was tested with the Wilcoxon signed rank test. The mean difference in lesion volume between automated outlines and manual outlines was -9.0 mL ± 44.5 (standard deviation). The lowest mean volume difference for the threshold approach was -25.8 mL ± 88.2. A significantly higher Dice coefficient was observed with the algorithm (0.71; interquartile range [IQR], 0.42-0.75) compared with the threshold approach (0.50; IQR, 0.27- 0.57; P , .001). The corresponding agreement among experts was 0.79 (IQR, 0.69-0.83). The perfusion lesions outlined by the automated algorithm agreed well with those defined manually in consensus by four experts and were superior to those obtained by using the standard threshold approach. This user-independent algorithm may improve the assessment of perfusion images as part of acute stroke treatment. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121622/-/DC1. RSNA, 2013

The Effects of Intravenous Hydration on Amniotic Fluid Volume and Pregnancy Outcomes in Women with Term Pregnancy and Oligohydramnios: A Randomized Clinical Trial

Directory of Open Access Journals (Sweden)

Mahnaz Shahnazi

2012-08-01

Full Text Available Introduction: Amniotic fluid is an important factor in the prediction of fetal survival. The aim of this research was to evaluate the effects of intravenous hydration of mothers on amniotic fluid volume and in turn on pregnancy outcomes. Methods: The current single blind controlled clinical trial was conducted on 20 pregnant mothers with amniot-ic fluid index of lower or equal to 5 cm and gestational age of 37-41 weeks. The subjects were divided into two groups of case and control through simple random sampling. Am-niotic fluid index was measured in all participants. The case group received one liter of isotonic saline during 30 minutes by the bolus method. Reevaluations of amniotic fluid index in both groups were made 90 minutes after baseline measurement. Independent t-test and paired t-test were used to compare the two groups and mean amniotic fluid in-dex before and after treatment, respectively. Results: Hydration of mothers significantly increased the amniotic fluid index in the case group (mean change: 1.5 cm; 95%CI: 0.46 - 2.64; P = 0.01. The mean change of amniotic fluid index in the control group did not significantly increase (P = 0.06. The elevation of amniotic fluid index in the hydra-tion group (32% was significantly higher than the control group (1% (P = 0.03. Conclusion: In this study intravenous hydration increased amniotic fluid index of mothers with term pregnancy and oligohydramnios. Since it caused no complications for the moth-er and the fetus, it can be used as an effective method in management of oligohydramnios.

Scanning electron microscopy of cells from periapical lesions.

Science.gov (United States)

Farber, P A

1975-09-01

Examination of lymphocytes from peripheral blood with the scanning electron microscope (SEM) has shown differences between B cells and T cells on the basis of their surface architecture. This study was initiated to determine whether the cellular components of periapical lesions could be identified with the use of similar criteria. Cells were dispersed from lesions by aspiration of fragments of tissue through syringe needles of decreasing diameters. The liberated cells were filtered on silver-coated Flotronic membranes and examined under the SEM. Lymphocytes, macrophages, epithelial cells, and mast cells were observed in granulomas and cysts. Most of the lymphocytes had smooth surfaces similar to that of T cells; others had villous projections similar to that of B cells. Epithelial nests were seen in the cyst linings while the cyst fluid was rich in lymphocytes. These findings suggest that SEM examination of periapical lesions can be a useful adjunct in studying cellular composition and possible immunological reactions in these tissues.

AFDM: An Advanced Fluid-Dynamics Model

International Nuclear Information System (INIS)

Wilhelm, D.

1990-09-01

This volume describes the Advanced Fluid-Dynamics Model (AFDM) for topologies, flow regimes, and interfacial areas. The objective of these models is to provide values for the interfacial areas between all components existing in a computational cell. The interfacial areas are then used to evaluate the mass, energy, and momentum transfer between the components. A new approach has been undertaken in the development of a model to convect the interfacial areas of the discontinuous velocity fields in the three-velocity-field environment of AFDM. These interfacial areas are called convectible surface areas. The continuous and discontinuous components are chosen using volume fraction and levitation criteria. This establishes so-called topologies for which the convectible surface areas can be determined. These areas are functions of space and time. Solid particulates that are limited to being discontinuous within the bulk fluid are assumed to have a constant size. The convectible surface areas are subdivided to model contacts between two discontinuous components or discontinuous components and the structure. The models have been written for the flow inside of large pools. Therefore, the structure is tracked only as a boundary to the fluid volume without having a direct influence on velocity or volume fraction distribution by means of flow regimes or boundary layer models. 17 refs., 7 tabs., 18 figs

Morel-Lavallee Lesion in the Upper Extremity.

Science.gov (United States)

Cochran, Grant K; Hanna, Kathryn H

2017-01-01

Background: The Morel-Lavallee lesion (MLL) is a closed internal degloving injury that results from shearing of the skin and subcutaneous tissue from the underlying fascia. Disruption of the perforating blood vessels and lymphatics results in a lesion filled with serosanguinous fluid and necrotized fat. MLLs are most commonly described in association with pelvic and lower extremity trauma, and there are limited reports of these lesions in other locations. Methods: This case report describes a 58-year-old male referred from his primary care physician with a soft tissue mass in the upper arm. Careful history discovered prior trauma with extensive bruising and MRI revealed a large encapsulated mass consistent with MLL. Results: An open debridement with excision of pseudocapsule was performed. Meticulous closure over a drain was performed and the patient healed without complication or recurrence. Intra-operative cultures were negative and pathology was consistent with MLL. Conclusion: MLL should always be considered in the setting of previous trauma regardless the location. In the chronic setting an open approach with excision of pseudocapsule can have an acceptable result.

Preintervention lesion remodelling affects operative mechanisms of balloon optimised directional coronary atherectomy procedures: a volumetric study with three dimensional intravascular ultrasound

Science.gov (United States)

von Birgelen, C; Mintz, G; de Vrey, E A; Serruys, P; Kimura, T; Nobuyoshi, M; Popma, J; Leon, M; Erbel, R; de Feyter, P J

2000-01-01

AIMS—To classify atherosclerotic coronary lesions on the basis of adequate or inadequate compensatory vascular enlargement, and to examine changes in lumen, plaque, and vessel volumes during balloon optimised directional coronary atherectomy procedures in relation to the state of adaptive remodelling before the intervention.
DESIGN—29 lesion segments in 29 patients were examined with intravascular ultrasound before and after successful balloon optimised directional coronary atherectomy procedures, and a validated volumetric intravascular ultrasound analysis was performed off-line to assess the atherosclerotic lesion remodelling and changes in plaque and vessel volumes that occurred during the intervention. Based on the intravascular ultrasound data, lesions were classified according to whether there was inadequate (group I) or adequate (group II) compensatory enlargement.
RESULTS—There was no significant difference in patient and lesion characteristics between groups I and II (n = 10 and 19), including lesion length and details of the intervention. Quantitative coronary angiographic data were similar for both groups. However, plaque and vessel volumes were significantly smaller in group I than in II. In group I, 9 (4)% (mean (SD)) of the plaque volume was ablated, while in group II 16 (11)% was ablated (p = 0.01). This difference was reflected in a lower lumen volume gain in group I than in group II (46 (18) mm3 v 80 (49) mm3 (p atherectomy procedures. Plaque ablation was found to be particularly low in lesions with inadequate compensatory vascular enlargement.


Keywords: intravascular ultrasound; ultrasonics; remodelling; coronary artery disease; atherectomy PMID:10648496

Thalamus lesions in chronic and acute seizure disorders

Energy Technology Data Exchange (ETDEWEB)

Tschampa, Henriette J; Greschus, Susanne; Urbach, Horst [University of Bonn, Department of Radiology (Neuroradiology), Bonn (Germany); Sassen, Robert; Bien, Christian G [University of Bonn, Department of Epileptology, Bonn (Germany)

2011-04-15

Transient signal changes in the pulvinar have been described following status epilepticus. However, we observed persistent thalamus changes after seizures. The purpose of this study was to characterize thalamus changes in patients with seizure disorders and to correlate imaging findings with clinical features. We searched among 5,500 magnetic resonance imaging (MRI) exams performed in patients with seizures and identified 43 patients. The MRI scans of these patients were reviewed and correlated with clinical data. We identified four patterns of thalamus lesions: (a) fluid attenuated inversion recovery-hyperintense pulvinar lesions (20 patients), as known from status epilepticus. Ten patients in this group had a status epilepticus. Among the remaining patients, three had frequent seizures and seven had sporadic seizures. Twelve patients had follow-up exams for a median of 11 months. The lesions had persisted in 11/12 cases in the last available exam and were reversible in one case only. In seven cases, cone-shaped thalamus atrophy resulted, (b) linear defects in the medial and anterior thalamus (five patients), accompanied by atrophy of the mamillary body and the fornix in patients with chronic epilepsy, (c) extensive bilateral thalamus lesions in two patients with a syndrome caused by mutation in the mitochondrial polymerase gamma, and (d) other thalamus lesions not associated with the seizure disorder (16 patients). The spectrum of thalamus lesions in patients with seizure disorders is wider than previously reported. Postictal pulvinar lesions can persist and may result in thalamic atrophy. Linear defects in the anterior thalamus are associated with limbic system atrophy. (orig.)

Thalamus lesions in chronic and acute seizure disorders

International Nuclear Information System (INIS)

Tschampa, Henriette J.; Greschus, Susanne; Urbach, Horst; Sassen, Robert; Bien, Christian G.

2011-01-01

Transient signal changes in the pulvinar have been described following status epilepticus. However, we observed persistent thalamus changes after seizures. The purpose of this study was to characterize thalamus changes in patients with seizure disorders and to correlate imaging findings with clinical features. We searched among 5,500 magnetic resonance imaging (MRI) exams performed in patients with seizures and identified 43 patients. The MRI scans of these patients were reviewed and correlated with clinical data. We identified four patterns of thalamus lesions: (a) fluid attenuated inversion recovery-hyperintense pulvinar lesions (20 patients), as known from status epilepticus. Ten patients in this group had a status epilepticus. Among the remaining patients, three had frequent seizures and seven had sporadic seizures. Twelve patients had follow-up exams for a median of 11 months. The lesions had persisted in 11/12 cases in the last available exam and were reversible in one case only. In seven cases, cone-shaped thalamus atrophy resulted, (b) linear defects in the medial and anterior thalamus (five patients), accompanied by atrophy of the mamillary body and the fornix in patients with chronic epilepsy, (c) extensive bilateral thalamus lesions in two patients with a syndrome caused by mutation in the mitochondrial polymerase gamma, and (d) other thalamus lesions not associated with the seizure disorder (16 patients). The spectrum of thalamus lesions in patients with seizure disorders is wider than previously reported. Postictal pulvinar lesions can persist and may result in thalamic atrophy. Linear defects in the anterior thalamus are associated with limbic system atrophy. (orig.)

Longitudinal in vivo magnetic resonance imaging studies in experimental allergic encephalomyelitis: effect of a neurotrophic treatment on cortical lesion development

International Nuclear Information System (INIS)

Gispen, W.H.; Nicolay, K.; Verhaagen, J.; Muller, H.J.; Duckers, H.J.

1997-01-01

Proton magnetic resonance imaging enables non-invasive monitoring of lesion formation in multiple sclerosis and has an important role in assessing the potential effects of therapy. T2-weighted and short τ inversion recovery magnetic resonance imaging were used to assess the effect of a neurotrophic adrenocorticotrophic hormone 4-9 analogue [H-Met(O 2 )-Glu-His-Phe-d-Lys-Phe-OH] on the volume of lesions in the brains of rats suffering from chronic experimental allergic encephalomyelitis, an animal equivalent of multiple sclerosis. Lesion volume was monitored during a five-month period. Magnetic resonance imaging indicated that treatment with the adrenocorticotrophic hormone 4-9 analogue significantly reduced the lesion volume by 84 and 85% 10 and 20 weeks after lesion induction, respectively. Furthermore, peptide treatment significantly reduced chronic experimental allergic encephalomyelitis-related neurological symptoms during the chronic phase of the disease (week 3 until week 20 after lesion induction). Both functional and morphological recovery were considerably advanced by peptide treatment. Twenty weeks after lesion induction rats with chronic experimental allergic encephalomyelitis were killed for histological analysis, to correlate magnetic resonance imaging findings with morphological changes. The regions of abnormally high signal intensities on T2-weighted magnetic resonance images coincided with areas of demyelination and concomitant widespread inflammatory infiltration, oedema formation and enlarged ventricles.The improved neurological status and the 84% reduction in the lesion volume in the cerebrum of rats chronic experimental allergic encephalomyelitis point to the potential value of trophic peptides in the development of strategies for limiting the damage caused by central demyelinating lesions in syndromes such as multiple sclerosis. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

Longitudinal in vivo magnetic resonance imaging studies in experimental allergic encephalomyelitis: effect of a neurotrophic treatment on cortical lesion development

Energy Technology Data Exchange (ETDEWEB)

Gispen, W.H. [Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Medical Faculty, Utrecht University Utrecht (Netherlands); Nicolay, K. [Department of in vivo NMR, Bijvoet Center, Utrecht University Utrecht (Netherlands); Verhaagen, J. [Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Medical Faculty, Utrecht University Utrecht (Netherlands); Muller, H.J. [Department of in vivo NMR, Bijvoet Center, Utrecht University Utrecht (Netherlands); Duckers, H.J. [Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Medical Faculty, Utrecht University Utrecht (Netherlands)

1997-02-14

Proton magnetic resonance imaging enables non-invasive monitoring of lesion formation in multiple sclerosis and has an important role in assessing the potential effects of therapy. T2-weighted and short {tau} inversion recovery magnetic resonance imaging were used to assess the effect of a neurotrophic adrenocorticotrophic hormone{sub 4-9} analogue [H-Met(O{sub 2})-Glu-His-Phe-d-Lys-Phe-OH] on the volume of lesions in the brains of rats suffering from chronic experimental allergic encephalomyelitis, an animal equivalent of multiple sclerosis. Lesion volume was monitored during a five-month period. Magnetic resonance imaging indicated that treatment with the adrenocorticotrophic hormone{sub 4-9} analogue significantly reduced the lesion volume by 84 and 85% 10 and 20 weeks after lesion induction, respectively. Furthermore, peptide treatment significantly reduced chronic experimental allergic encephalomyelitis-related neurological symptoms during the chronic phase of the disease (week 3 until week 20 after lesion induction). Both functional and morphological recovery were considerably advanced by peptide treatment. Twenty weeks after lesion induction rats with chronic experimental allergic encephalomyelitis were killed for histological analysis, to correlate magnetic resonance imaging findings with morphological changes. The regions of abnormally high signal intensities on T2-weighted magnetic resonance images coincided with areas of demyelination and concomitant widespread inflammatory infiltration, oedema formation and enlarged ventricles.The improved neurological status and the 84% reduction in the lesion volume in the cerebrum of rats chronic experimental allergic encephalomyelitis point to the potential value of trophic peptides in the development of strategies for limiting the damage caused by central demyelinating lesions in syndromes such as multiple sclerosis. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

PULSE RADIOLYSIS IN SUPERCRITICAL RARE GAS FLUIDS

International Nuclear Information System (INIS)

HOLROYD, R.

2007-01-01

Recently, supercritical fluids have become quite popular in chemical and semiconductor industries for applications in chemical synthesis, extraction, separation processes, and surface cleaning. These applications are based on: the high dissolving power due to density build-up around solute molecules, and the ability to tune the conditions of a supercritical fluid, such as density and temperature, that are most suitable for a particular reaction. The rare gases also possess these properties and have the added advantage of being supercritical at room temperature. Information about the density buildup around both charged and neutral species can be obtained from fundamental studies of volume changes in the reactions of charged species in supercritical fluids. Volume changes are much larger in supercritical fluids than in ordinary solvents because of their higher compressibility. Hopefully basic studies, such as discussed here, of the behavior of charged species in supercritical gases will provide information useful for the utilization of these solvents in industrial applications

Simulation based engineering in fluid flow design

CERN Document Server

Rao, J S

2017-01-01

This volume offers a tool for High Performance Computing (HPC). A brief historical background on the subject is first given. Fluid Statics dealing with Pressure in fluids at rest, Buoyancy and Basics of Thermodynamics are next presented. The Finite Volume Method, the most convenient process for HPC, is explained in one-dimensional approach to diffusion with convection and pressure velocity coupling. Adiabatic, isentropic and supersonic flows in quasi-one dimensional flows in axisymmetric nozzles is considered before applying CFD solutions. Though the theory is restricted to one-dimensional cases, three-dimensional CFD examples are also given. Lastly, nozzle flows with normal shocks are presented using turbulence models. Worked examples and exercises are given in each chapter. Fluids transport thermal energy for its conversion to kinetic energy, thus playing a major role that is central to all heat engines. With the advent of rotating machinery in the 20th century, Fluid Engineering was developed in the form o...

Development of a multiplex real-time PCR for the simultaneous detection of herpes simplex and varicella zoster viruses in cerebrospinal fluid and lesion swab specimens.

Science.gov (United States)

Wong, Anita A; Pabbaraju, Kanti; Wong, Sallene; Tellier, Raymond

2016-03-01

Herpes simplex viruses (HSV) and varicella zoster virus (VZV) can have very similar and wide-ranging clinical presentations. Rapid identification is necessary for timely antiviral therapy, especially with infections involving the central nervous system, neonates, and immunocompromised individuals. Detection of HSV-1, HSV-2 and VZV was combined into one real-time PCR reaction utilizing hydrolysis probes. The assay was validated on the LightCycler(®) (Roche) and Applied Biosystems 7500 Real-Time PCR System (Thermo Fisher Scientific Inc.) to detect alphaherpesviruses in cerebral spinal fluid (CSF) and lesion swab specimens, respectively. Validation data on blood and tissue samples are also presented. The multiplex assay showed excellent sensitivity, specificity and reproducibility when compared to two singleplex real-time PCR assays for CSF samples and direct fluorescent antigen/culture for lesion swab samples. Implementation of the multiplex assay has facilitated improved sensitivity and accuracy as well as reduced turn-around-times and costs. The results from a large data set of 16,622 prospective samples tested between August 16, 2012 to February 1, 2014 at the Provincial Laboratory for Public Health (Alberta, Canada) are presented here. Copyright © 2015 Elsevier B.V. All rights reserved.

Impact of perfusion lesion in corticospinal tract on response to reperfusion

Energy Technology Data Exchange (ETDEWEB)

Zhou, Ying; Zhang, Ruiting; Zhang, Sheng; Yan, Shenqiang; Lou, Min [Second Affiliated Hospital of Zhejiang University, School of Medicine, Department of Neurology, Hangzhou (China); Wang, Ze [Hangzhou Normal University, Center for Cognition and Brain Disorders, Institutes of Neurological Science, Hangzhou (China); Affiliated Hospital of Hangzhou Normal University, Hangzhou (China); Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou (China); Campbell, Bruce C.V. [University of Melbourne, Department of Medicine and Neurology, Royal Melbourne Hospital, Parkville (Australia); Liebeskind, David S. [Los Angeles Stroke Center, University of California, Los Angeles, CA (United States)

2017-12-15

We aimed to examine the impact of corticospinal tract (CST) involvement in acute ischaemic stroke (AIS) patients on functional outcome and the interaction with reperfusion. We retrospectively examined data in consecutive anterior circulation AIS patients undergoing thrombolysis. MR perfusion (time to maximum of tissue residue function, Tmax) and apparent diffusion coefficient (ADC) images were transformed into standard space and the volumes of CST involvement by Tmax > 6 s (CST-Tmax) and ADC < 620 x 10{sup -6} mm{sup 2}/s (CST-ADC) lesions were calculated. Good outcome was defined as modified Rankin scale ≤ 2 at 3 months. Reperfusion was defined as a reduction in Tmax > 6 s lesion volume of ≥70% between baseline and 24 h. 82 patients were included. Binary logistic regression revealed that both CST-Tmax and CST-ADC volume at baseline were significantly associated with poor outcome (p < 0.05). The 24-h CST-ADC volume was correlated with baseline CST-ADC volume in patients with reperfusion (r = 0.79, p < 0.001) and baseline CST-Tmax volume in patients without reperfusion (r = 0.67, p < 0.001). In patients with CST-Tmax volume > 0 mL and CST-ADC volume < 3 mL, the rate of good outcome was higher in patients with reperfusion than those without (70.4% vs 38.1%, p = 0.04). The use of CST-Tmax in combination with CST-ADC provides prognostic information in patients considered for reperfusion therapies. (orig.)

The value of whole lesion ADC histogram profiling to differentiate between morphologically indistinguishable ring enhancing lesions-comparison of glioblastomas and brain abscesses.

Science.gov (United States)

Horvath-Rizea, Diana; Surov, Alexey; Hoffmann, Karl-Titus; Garnov, Nikita; Vörkel, Cathrin; Kohlhof-Meinecke, Patricia; Ganslandt, Oliver; Bäzner, Hansjörg; Gihr, Georg Alexander; Kalman, Marcell; Henkes, Elina; Henkes, Hans; Schob, Stefan

2018-04-06

Morphologically similar appearing ring enhancing lesions in the brain parenchyma can be caused by a number of distinct pathologies, however, they consistently represent life-threatening conditions. The two most frequently encountered diseases manifesting as such are glioblastoma multiforme (GBM) and brain abscess (BA), each requiring disparate therapeutical approaches. As a result of their morphological resemblance, essential treatment might be significantly delayed or even ommited, in case results of conventional imaging remain inconclusive. Therefore, our study aimed to investigate, whether ADC histogram profiling reliably can distinguish between both entities, thus enhancing the differential diagnostic process and preventing treatment failure in this highly critical context. 103 patients (51 BA, 52 GBM) with histopathologically confirmed diagnosis were enrolled. Pretreatment diffusion weighted imaging (DWI) was obtained in a 1.5T system using b values of 0, 500, and 1000 s/mm 2 . Whole lesion ADC volumes were analyzed using a histogram-based approach. Statistical analysis was performed using SPSS version 23. All investigated parameters were statistically different in comparison of both groups. Most importantly, ADCp10 was able to differentiate reliably between BA and GBM with excellent accuracy (0.948) using a cutpoint value of 70 × 10 -5 mm 2 × s -1 . ADC whole lesion histogram profiling provides a valuable tool to differentiate between morphologically indistinguishable mass lesions. Among the investigated parameters, the 10th percentile of the ADC volume distinguished best between GBM and BA.

Three-dimensional blade coating of complex fluid

Science.gov (United States)

Singh, Vachitar; Grimaldi, Emma; Sauret, Alban; Dressaire, Emilie

2015-11-01

The application of a layer of non-newtonian fluid on a solid substrate is an important industrial problem involved in polymer or paint coatings, and an everyday life challenge when it comes to spreading peanut butter on a toast. Most experimental and theoretical work has focused on the two-dimensional situation, i.e. the scraping of a fixed blade on a moving substrate to turn a thick layer of liquid into a thin coat. However the spreading of a finite volume of non-newtonian fluid using a blade has received less attention, despite significant practical and fundamental implications. In this study, we investigate experimentally the spreading of a finite volume of a model non-newtonian fluid, carbopol, initially deposited against the fixed blade. As the substrate is translated at constant speed, we characterize the dynamics of spreading and the final shape of the coated layer. We measure and rationalize the influence of the liquid volume, the height and orientation of the blade, and the speed of the substrate on the spreading.

Fluid resuscitation practices in cardiac surgery patients in the USA: a survey of health care providers

Directory of Open Access Journals (Sweden)

Solomon Aronson

2017-10-01

Full Text Available Abstract Background Fluid resuscitation during cardiac surgery is common with significant variability in clinical practice. Our goal was to investigate current practice patterns of fluid volume expansion in patients undergoing cardiac surgeries in the USA. Methods We conducted a cross-sectional online survey of 124 cardiothoracic surgeons, cardiovascular anesthesiologists, and perfusionists. Survey questions were designed to assess clinical decision-making patterns of intravenous (IV fluid utilization in cardiovascular surgery for five types of patients who need volume expansion: (1 patients undergoing cardiopulmonary bypass (CPB without bleeding, (2 patients undergoing CPB with bleeding, (3 patients undergoing acute normovolemic hemodilution (ANH, (4 patients requiring extracorporeal membrane oxygenation (ECMO or use of a ventricular assist device (VAD, and (5 patients undergoing either off-pump coronary artery bypass graft (OPCABG surgery or transcatheter aortic valve replacement (TAVR. First-choice fluid used in fluid boluses for these five patient types was requested. Descriptive statistics were performed using Kruskal-Wallis test and follow-up tests, including t tests, to evaluate differences among respondent groups. Results The most commonly preferred indicators of volume status were blood pressure, urine output, cardiac output, central venous pressure, and heart rate. The first choice of fluid for patients needing volume expansion during CPB without bleeding was crystalloids, whereas 5% albumin was the most preferred first choice of fluid for bleeding patients. For volume expansion during ECMO or VAD, the respondents were equally likely to prefer 5% albumin or crystalloids as a first choice of IV fluid, with 5% albumin being the most frequently used adjunct fluid to crystalloids. Surgeons, as a group, more often chose starches as an adjunct fluid to crystalloids for patients needing volume expansion during CPB without bleeding. Surgeons

Orthostatic leg blood volume changes assessed by near-infrared spectroscopy

DEFF Research Database (Denmark)

Truijen, J; Kim, Y S; Krediet, C T P

2012-01-01

posture, volume accumulation in small blood vessels contributes significantly to the total fluid volume accumulated in the legs. Considering that near-infrared spectroscopy (NIRS) tracks postural blood volume changes within the small blood vessels of the lower leg, we evaluated the NIRS-determined changes......-linear accumulation of blood volume in the small vessels of the leg, with an initial fast phase followed by a more gradual increase at least partly contributing to the relocation of fluid during orthostatic stress....

Anti-N-methyl-D-aspartate receptor encephalitis concomitant with multifocal subcortical white matter lesions on magnetic resonance imaging: a case report and review of the literature.

Science.gov (United States)

Wang, Rui-Jin; Chen, Bu-Dong; Qi, Dong

2015-07-08

Anti-N-methyl-D-aspartate receptor encephalitis is a severe autoimmune disorder characterized by severe psychiatric symptoms, seizures, decreased consciousness, autonomic dysregulation, and dyskinesias. Multifocal subcortical white matter lesions on fluid-attenuated inversion recovery and diffuse weighted images have rarely been reported in previous literature, and serial magnetic resonance imaging changes after plasma exchange have not been presented before. A previously healthy 24-year-old Chinese woman presented with acute psychiatric symptoms characterized by fear and agitation followed by decreased consciousness, dyskinesias, and seizures. Magnetic resonance imaging revealed hyperintense lesions on fluid-attenuated inversion recovery and diffuse weighted images in bilateral subcortical white matter. Cerebrospinal fluid analysis revealed a mild pleocytosis with lymphocytic predominance. Protein and glucose levels were normal. Aquaporin-4 antibodies in serum and cerebrospinal fluid were negative. Identification of anti-N-methyl-D-aspartate receptor antibodies in serum and cerebrospinal fluid confirmed the diagnosis of anti-N-methyl-D-aspartate receptor encephalitis. She was initially treated with combined intravenous immunoglobulin and methylprednisolone without improvement. Plasma exchange was then initiated with good response; the patient made a full recovery after several cycles of plasma exchange. Repeat magnetic resonance imaging performed 1 month after plasma exchange showed partial resolution of the hyperintense lesions in bilateral subcortical white matter, and follow-up magnetic resonance imaging 2 months after plasma exchange showed complete resolution. Anti-N-methyl-D-aspartate receptor encephalitis may be concomitant with multifocal subcortical white matter lesions. Such lesions may resolve after appropriate immunotherapy.

Extracellular fluid volume expansion and third space sequestration at the site of small bowel anastomoses.

Science.gov (United States)

Chan, S T; Kapadia, C R; Johnson, A W; Radcliffe, A G; Dudley, H A

1983-01-01

Intestinal surgery is usually associated with the parenteral administration of sodium and water, sometimes in amounts considerably in excess of excretory capacity. We have studied the effect of this situation on the water content of the gut at and 5 cm from a single-layer end-to-end anastomosis in the rabbit. Water content was measured by desiccation. One group of animals (group 1) did not receive intravenous therapy. The second group (group 2) received 5 ml kg-1 h-1 of Hartmann's solution during the operative period and thereafter to a total volume of 200 ml by 48 h. In group 1 there was a 5-10 per cent increase in tissue weight both at the anastomotic site and at 5 cm (P less than 0.01, Mann-Whitney U test) on the first 3 days. Thereafter, water content at the anastomosis persisted, but resolved in normal gut. In group 2 a further 5 per cent increase in weight over group 1 occurred (P less than 0.01), persistent at the anastomotic site over 5 days, though resolving elsewhere after 2 days. Extracellular fluid volume expansion exaggerates an anatomical third space present in the region of an anastomosis. At the suture line, oedema so induced is persistent and could be deleterious.

The relationship between nocturnal polyuria and the distribution of body fluid: assessment by bioelectric impedance analysis.

Science.gov (United States)

Torimoto, Kazumasa; Hirayama, Akihide; Samma, Shoji; Yoshida, Katsunori; Fujimoto, Kiyohide; Hirao, Yoshihiko

2009-01-01

Increased nocturnal urinary volume is closely associated with nocturia. We investigated the relationship between nocturnal polyuria and the variation of body fluid distribution during the daytime using bioelectric impedance analysis. A total of 34 men older than 60 years were enrolled in this study. A frequency volume chart was recorded. Nocturnal polyuria was defined as a nocturnal urine volume per 24-hour production of greater than 0.35 (the nocturnal polyuria index). Bioelectric impedance analysis was performed 4 times daily at 8 and 11 a.m., and 5 and 9 p.m. using an InBody S20 body composition analyzer (BioSpace, Seoul, Korea). A significant difference was found in mean +/- SEM 24-hour urine production per fat-free mass between the groups with and without nocturnal polyuria (17.8 +/- 1.4 vs 7.7 +/- 0.9 ml/kg). The increase in fluid in the legs compared with the volume at 8 a.m. was significantly larger at 5 p.m., while there was no difference in the arms or trunk. Nocturnal urine volume significantly correlated with the difference in fluid volume in the legs (r = 0.527, p = 0.0019) and extracellular fluid volume (r = 0.3844, p = 0.0248) between the volumes at 8 a.m. and 9 p.m. Overproduction of urine per fat-free mass leads to nocturnal polyuria. Extracellular fluid accumulates as edema in the legs during the day in patients with nocturnal polyuria. The volume of accumulated extracellular fluid correlates with nocturnal urine volume. We suggest that leg edema is the source of nocturnal urine volume and decreasing edema may cure nocturnal polyuria.

Topological characteristics of brainstem lesions in clinically definite and clinically probable cases of multiple sclerosis: An MRI-study

International Nuclear Information System (INIS)

Brainin, M.; Omasits, M.; Reisner, T.; Neuhold, A.; Wicke, L.

1987-01-01

Disseminated lesions in the white matter of the cerebral hemispheres and confluent lesions at the borders of the lateral ventricles as seen on MRI are both considered acceptable paraclinical evidence for the diagnosis of multiple sclerosis. Similar changes are, however, also found in vascular diseases of the brain. We therefore aimed at identifying those additional traits in the infratentorial region, which in our experience are not frequently found in cerebrovascular pathology. We evaluated MR brain scans of 68 patients and found pontine lesions in 71% of cases with a clinically definite diagnosis (17 out of 24) and in 33% of cases with a probable diagnosis (14 out of 43). Lesions in the medulla oblongata were present in 50% and 16%, respectively, and in the midbrain in 25% and 7%, respectively. With rare exceptions all brainstem lesions were contiguous with the cisternal or ventricular cerebrospinal fluid spaces. In keeping with post-mortem reports the morphological spectrum ranged from large confluent patches to solitary, well delineated paramedian lesions or discrete linings of the cerebrospinal fluid border zones and were most clearly depicted from horizontal and sagittal T2 weighted SE-sequences. If there is a predilection for the outer or inner surfaces of the brainstem, such lesions can be considered an additional typical feature of multiple sclerosis and can be more reliably weighted as paraclinical evidence for a definite diagnosis. (orig.)

Agarwood Waste as A New Fluid Loss Control Agent in Water-based Drilling Fluid

Directory of Open Access Journals (Sweden)

Azlinda Azizi

2013-10-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Agarwood has been used widely in various ways, including traditional medicine and art. The usage of agarwood has grown broader in modern times include in therapeutic medicines and perfumery. In this paper the agarwood waste has been explored to be used as a fluid loss control agent to control fluid loss without affecting the drilling fluid rheological properties which are density, pH, viscosity, yield point and gel strength. Agarwood waste was used as an additive in the drilling fluid system due to its unique characteristic. Rheological and filtration measurements were performed on the formulated water-based drilling fluid. Formulations of a base solution of fresh water, sodium hydroxide, bentonite, barite, and xanthan gum were presented. The performance of the agarwood waste as the fluid loss control agent was compared with based fluid formulation and water-based drilling fluid with treating with conventional fluid loss control agent (starch. The filtrate volume of drilling fluid with agarwood waste was about 13 ml while for drilling fluid with conventional fluid loss control agent, starch gave 12 ml of filtrate volume after undergoing filtration test by using LPLT filter press. The performance of drilling fluid with agarwood was efficient as drilling fluid with starch. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso

Toward Prostate Cancer Contouring Guidelines on Magnetic Resonance Imaging: Dominant Lesion Gross and Clinical Target Volume Coverage Via Accurate Histology Fusion

International Nuclear Information System (INIS)

Gibson, Eli; Bauman, Glenn S.; Romagnoli, Cesare; Cool, Derek W.; Bastian-Jordan, Matthew; Kassam, Zahra; Gaed, Mena; Moussa, Madeleine; Gómez, José A.; Pautler, Stephen E.; Chin, Joseph L.; Crukley, Cathie; Haider, Masoom A.

2016-01-01

Purpose: Defining prostate cancer (PCa) lesion clinical target volumes (CTVs) for multiparametric magnetic resonance imaging (mpMRI) could support focal boosting or treatment to improve outcomes or lower morbidity, necessitating appropriate CTV margins for mpMRI-defined gross tumor volumes (GTVs). This study aimed to identify CTV margins yielding 95% coverage of PCa tumors for prospective cases with high likelihood. Methods and Materials: Twenty-five men with biopsy-confirmed clinical stage T1 or T2 PCa underwent pre-prostatectomy mpMRI, yielding T2-weighted, dynamic contrast-enhanced, and apparent diffusion coefficient images. Digitized whole-mount histology was contoured and registered to mpMRI scans (error ≤2 mm). Four observers contoured lesion GTVs on each mpMRI scan. CTVs were defined by isotropic and anisotropic expansion from these GTVs and from multiparametric (unioned) GTVs from 2 to 3 scans. Histologic coverage (proportions of tumor area on co-registered histology inside the CTV, measured for Gleason scores [GSs] ≥6 and ≥7) and prostate sparing (proportions of prostate volume outside the CTV) were measured. Nonparametric histologic-coverage prediction intervals defined minimal margins yielding 95% coverage for prospective cases with 78% to 92% likelihood. Results: On analysis of 72 true-positive tumor detections, 95% coverage margins were 9 to 11 mm (GS ≥ 6) and 8 to 10 mm (GS ≥ 7) for single-sequence GTVs and were 8 mm (GS ≥ 6) and 6 mm (GS ≥ 7) for 3-sequence GTVs, yielding CTVs that spared 47% to 81% of prostate tissue for the majority of tumors. Inclusion of T2-weighted contours increased sparing for multiparametric CTVs with 95% coverage margins for GS ≥6, and inclusion of dynamic contrast-enhanced contours increased sparing for GS ≥7. Anisotropic 95% coverage margins increased the sparing proportions to 71% to 86%. Conclusions: Multiparametric magnetic resonance imaging–defined GTVs expanded by appropriate margins

Toward Prostate Cancer Contouring Guidelines on Magnetic Resonance Imaging: Dominant Lesion Gross and Clinical Target Volume Coverage Via Accurate Histology Fusion

Energy Technology Data Exchange (ETDEWEB)

Gibson, Eli [Robarts Research Institute, University of Western Ontario, London, Ontario (Canada); Biomedical Engineering, University of Western Ontario, London, Ontario (Canada); Centre for Medical Image Computing, University College London, London (United Kingdom); Department of Radiology, Radboud University Medical Centre, Nijmegen (Netherlands); Bauman, Glenn S., E-mail: glenn.bauman@lhsc.on.ca [Lawson Health Research Institute, London, Ontario (Canada); Department of Oncology, University of Western Ontario, London, Ontario (Canada); Romagnoli, Cesare; Cool, Derek W. [Department of Medical Imaging, University of Western Ontario, London, Ontario (Canada); Bastian-Jordan, Matthew [Department of Medical Imaging, University of Western Ontario, London, Ontario (Canada); Queensland Health, Brisbane, Queensland (Australia); Kassam, Zahra [Department of Medical Imaging, University of Western Ontario, London, Ontario (Canada); Gaed, Mena [Robarts Research Institute, University of Western Ontario, London, Ontario (Canada); Department of Pathology, University of Western Ontario, London, Ontario (Canada); Moussa, Madeleine; Gómez, José A. [Department of Pathology, University of Western Ontario, London, Ontario (Canada); Pautler, Stephen E.; Chin, Joseph L. [Lawson Health Research Institute, London, Ontario (Canada); Department of Urology, University of Western Ontario, London, Ontario (Canada); Crukley, Cathie [Robarts Research Institute, University of Western Ontario, London, Ontario (Canada); Lawson Health Research Institute, London, Ontario (Canada); Haider, Masoom A. [Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); and others

2016-09-01

Purpose: Defining prostate cancer (PCa) lesion clinical target volumes (CTVs) for multiparametric magnetic resonance imaging (mpMRI) could support focal boosting or treatment to improve outcomes or lower morbidity, necessitating appropriate CTV margins for mpMRI-defined gross tumor volumes (GTVs). This study aimed to identify CTV margins yielding 95% coverage of PCa tumors for prospective cases with high likelihood. Methods and Materials: Twenty-five men with biopsy-confirmed clinical stage T1 or T2 PCa underwent pre-prostatectomy mpMRI, yielding T2-weighted, dynamic contrast-enhanced, and apparent diffusion coefficient images. Digitized whole-mount histology was contoured and registered to mpMRI scans (error ≤2 mm). Four observers contoured lesion GTVs on each mpMRI scan. CTVs were defined by isotropic and anisotropic expansion from these GTVs and from multiparametric (unioned) GTVs from 2 to 3 scans. Histologic coverage (proportions of tumor area on co-registered histology inside the CTV, measured for Gleason scores [GSs] ≥6 and ≥7) and prostate sparing (proportions of prostate volume outside the CTV) were measured. Nonparametric histologic-coverage prediction intervals defined minimal margins yielding 95% coverage for prospective cases with 78% to 92% likelihood. Results: On analysis of 72 true-positive tumor detections, 95% coverage margins were 9 to 11 mm (GS ≥ 6) and 8 to 10 mm (GS ≥ 7) for single-sequence GTVs and were 8 mm (GS ≥ 6) and 6 mm (GS ≥ 7) for 3-sequence GTVs, yielding CTVs that spared 47% to 81% of prostate tissue for the majority of tumors. Inclusion of T2-weighted contours increased sparing for multiparametric CTVs with 95% coverage margins for GS ≥6, and inclusion of dynamic contrast-enhanced contours increased sparing for GS ≥7. Anisotropic 95% coverage margins increased the sparing proportions to 71% to 86%. Conclusions: Multiparametric magnetic resonance imaging–defined GTVs expanded by appropriate margins

Pediatric Acute Respiratory Distress Sydnrome : Fluid Management in the PICU

NARCIS (Netherlands)

Ingelse, SA; Wösten-van Asperen, RM; Lemson, J; Daams, JG; Bem, R.A.; van Woensel, JB

2016-01-01

The administration of an appropriate volume of intravenous fluids, while avoiding fluid overload, is a major challenge in the pediatric intensive care unit. Despite our efforts, fluid overload is a very common clinical observation in critically ill children, in particular in those with pediatric

Pediatric Acute Respiratory Distress Syndrome: Fluid Management in the PICU

NARCIS (Netherlands)

Ingelse, Sarah A.; Wösten-van Asperen, Roelie M.; Lemson, Joris; Daams, Joost G.; Bem, Reinout A.; van Woensel, Job B.

2016-01-01

The administration of an appropriate volume of intravenous fluids, while avoiding fluid overload, is a major challenge in the pediatric intensive care unit. Despite our efforts, fluid overload is a very common clinical observation in critically ill children, in particular in those with pediatric

Spinal cord constraints in the era of high-precision radiotherapy. Retrospective analysis of 62 spinal/paraspinal lesions with possible infringements of spinal cord constraints within a minimal volume

Energy Technology Data Exchange (ETDEWEB)

Zschaeck, Sebastian; Wust, Peter; Graf, Reinhold; Wlodarczyk, Waldemar; Schild, Reinhard; Thieme, Alexander Henry; Weihrauch, Mirko; Budach, Volker; Ghadjar, Pirus [Charite Centrum Tumormedizin CC14, Klinik fuer Radioonkologie und Strahlentherapie, Berlin (Germany)

2017-07-15

Current constraints aim to minimize the risk of radiation myelitis by the use of restrictive maximal spinal cord doses, commonly 50 Gy. However, several studies suggested that a dose-volume effect could exist. Based on these observations, we evaluated patients receiving potentially excessive doses to the spinal cord within minimal volumes. Patients receiving radiotherapy between June 2010 and May 2015 using the Novalis trademark (Varian, Palo Alto, CA, USA; Brainlab, Heimstetten, Germany) radiosurgery system were retrospectively analyzed. A total of 56 patients with 62 treated lesions that had been prescribed radiation doses close to the spinal cord potentially higher than the common 50 Gy 2-Gy equivalent-dose (EQD2) constraint were selected for further analysis. Of these patients, 26 with 31 lesions had no history of previous irradiation, while 30 patients with 31 lesions had been previously irradiated within the treatment field. According to different dose evaluation approaches (spinal canal, spinal cord contour), 16 and 10 out of 31 primary irradiated lesions infringed constraints. For the 16 lesions violating spinal canal doses, the maximum doses ranged from 50.5 to 61.9 Gy EQD2. Reirradiated lesions had an average and median cumulative dose of 70.5 and 69 Gy, respectively. Dose drop-off was steep in both groups. Median overall survival was 17 months. No radiation myelitis or radiomorphological alterations were observed during follow-up. This study adds to the increasing body of evidence indicating that excessive spinal cord doses within a minimal volume, especially in a reirradiation setting with topographically distinct high-point doses, may be given to patients after careful evaluation of treatment- and tumor-associated risks. (orig.) [German] Um das Risiko einer radiogenen Myelitis zu minimieren, sind klinisch gebraeuchliche Dosisobergrenzen fuer das Rueckenmark mit 50-Gy-Maximaldosis sehr restriktiv. Einige Veroeffentlichungen deuten jedoch darauf hin

CFDLIB05, Computational Fluid Dynamics Library

International Nuclear Information System (INIS)

Kashiwa, B.A.; Padial, N.T.; Rauenzahn, R.M.; VanderHeyden, W.B.

2007-01-01

1 - Description of program or function: CFDLib05 is the Los Alamos Computational Fluid Dynamics Library. This is a collection of hydro-codes using a common data structure and a common numerical method, for problems ranging from single-field, incompressible flow, to multi-species, multi-field, compressible flow. The data structure is multi-block, with a so-called structured grid in each block. The numerical method is a Finite-Volume scheme employing a state vector that is fully cell-centered. This means that the integral form of the conversation laws is solved on the physical domain that is represented by a mesh of control volumes. The typical control volume is an arbitrary quadrilateral in 2D and an arbitrary hexahedron in 3D. The Finite-Volume scheme is for time-unsteady flow and remains well coupled by means of time and space centered fluxes; if a steady state solution is required, the problem is integrated forward in time until the user is satisfied that the state is stationary. 2 - Methods: Cells-centered Implicit Continuous-fluid Eulerian (ICE) method

CRITICALITY CURVES FOR PLUTONIUM HYDRAULIC FLUID MIXTURES

International Nuclear Information System (INIS)

WITTEKIND WD

2007-01-01

This Calculation Note performs and documents MCNP criticality calculations for plutonium (100% 239 Pu) hydraulic fluid mixtures. Spherical geometry was used for these generalized criticality safety calculations and three geometries of neutron reflection are: (sm b ullet)bare, (sm b ullet)1 inch of hydraulic fluid, or (sm b ullet)12 inches of hydraulic fluid. This document shows the critical volume and critical mass for various concentrations of plutonium in hydraulic fluid. Between 1 and 2 gallons of hydraulic fluid were discovered in the bottom of HA-23S. This HA-23S hydraulic fluid was reported by engineering to be Fyrquel 220. The hydraulic fluid in GLovebox HA-23S is Fyrquel 220 which contains phosphorus. Critical spherical geometry in air is calculated with 0 in., 1 in., or 12 inches hydraulic fluid reflection

Quantitative performance evaluation of 124I PET/MRI lesion dosimetry in differentiated thyroid cancer

Science.gov (United States)

Wierts, R.; Jentzen, W.; Quick, H. H.; Wisselink, H. J.; Pooters, I. N. A.; Wildberger, J. E.; Herrmann, K.; Kemerink, G. J.; Backes, W. H.; Mottaghy, F. M.

2018-01-01

The aim was to investigate the quantitative performance of 124I PET/MRI for pre-therapy lesion dosimetry in differentiated thyroid cancer (DTC). Phantom measurements were performed on a PET/MRI system (Biograph mMR, Siemens Healthcare) using 124I and 18F. The PET calibration factor and the influence of radiofrequency coil attenuation were determined using a cylindrical phantom homogeneously filled with radioactivity. The calibration factor was 1.00  ±  0.02 for 18F and 0.88  ±  0.02 for 124I. Near the radiofrequency surface coil an underestimation of less than 5% in radioactivity concentration was observed. Soft-tissue sphere recovery coefficients were determined using the NEMA IEC body phantom. Recovery coefficients were systematically higher for 18F than for 124I. In addition, the six spheres of the phantom were segmented using a PET-based iterative segmentation algorithm. For all 124I measurements, the deviations in segmented lesion volume and mean radioactivity concentration relative to the actual values were smaller than 15% and 25%, respectively. The effect of MR-based attenuation correction (three- and four-segment µ-maps) on bone lesion quantification was assessed using radioactive spheres filled with a K2HPO4 solution mimicking bone lesions. The four-segment µ-map resulted in an underestimation of the imaged radioactivity concentration of up to 15%, whereas the three-segment µ-map resulted in an overestimation of up to 10%. For twenty lesions identified in six patients, a comparison of 124I PET/MRI to PET/CT was performed with respect to segmented lesion volume and radioactivity concentration. The interclass correlation coefficients showed excellent agreement in segmented lesion volume and radioactivity concentration (0.999 and 0.95, respectively). In conclusion, it is feasible that accurate quantitative 124I PET/MRI could be used to perform radioiodine pre-therapy lesion dosimetry in DTC.

Infusion volume control and calculation using metronome and drop counter based intravenous infusion therapy helper.

Science.gov (United States)

Park, Kyungnam; Lee, Jangyoung; Kim, Soo-Young; Kim, Jinwoo; Kim, Insoo; Choi, Seung Pill; Jeong, Sikyung; Hong, Sungyoup

2013-06-01

This study assessed the method of fluid infusion control using an IntraVenous Infusion Controller (IVIC). Four methods of infusion control (dial flow controller, IV set without correction, IV set with correction and IVIC correction) were used to measure the volume of each technique at two infusion rates. The infused fluid volume with a dial flow controller was significantly larger than other methods. The infused fluid volume was significantly smaller with an IV set without correction over time. Regarding the concordance correlation coefficient (CCC) of infused fluid volume in relation to a target volume, IVIC correction was shown to have the highest level of agreement. The flow rate measured in check mode showed a good agreement with the volume of collected fluid after passing through the IV system. Thus, an IVIC could assist in providing an accurate infusion control. © 2013 Wiley Publishing Asia Pty Ltd.

Structural studies of fluid mercury using synchrotron radiation at SPring-8

International Nuclear Information System (INIS)

Hong Xinguo; Tamura, K.

2003-01-01

With the volume expansion by heating up toward the critical point, typical liquid metal mercury undergoes metal-nonmetal transition (M-NM) at a density around 9 g/cm 3 . To study the structure changes of fluid Hg during volume expansion, we have carried out X-ray diffraction measurements for expanded fluid mercury in a wide density region from liquid to dense vapour region using synchrotron radiation at SPring-8. We have succeeded in developing a new high-pressure vessel, up to 1700 degree C under 2000 bar and with 7 scattering windows for energy-dispersive X-ray diffraction (EDXD) measurements under high temperature and high pressure. It was found that the reliability of the structure factors, S(k), and the accuracy of the pair distribution functions, g(r), are much better. Reliable relations of the coordination number and the correlation distance with the density of fluid Hg were obtained. Structural model of volume expansion of fluid Hg is proposed based on our new results. Structural changes with decreasing density are discussed in relation to the M-NM transition in fluid Hg

Cerebellar Lesions of Uremic Encephalopathy on MRI in Hemodialyzed Diabetic Patient: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Kil, Min Chul; Lee, Seung Young; Cha, Sang Hoon; Cho, Bum Sang; Kang, Min Ho [Dept. of Radiology, Chungbuk National Universty Hospital, Cheongju (Korea, Republic of)

2012-01-15

Uremic encephalopathy (UE) is a well-known complication of uremia, but its pathophysiology remains unknown. It is widely reported that in UE, the bilateral basal ganglia (BG) shows hyperintensities on T2/fluid attenuated inversion recovery magnetic resonance imaging (MRI), but cerebellar lesions are extremely rare, with to the best of our knowledge, only one case reported to date. We describe the findings from computed tomography and MRI for typical BG and cerebellar vermis lesions.

Cerebellar Lesions of Uremic Encephalopathy on MRI in Hemodialyzed Diabetic Patient: A Case Report

International Nuclear Information System (INIS)

Kil, Min Chul; Lee, Seung Young; Cha, Sang Hoon; Cho, Bum Sang; Kang, Min Ho

2012-01-01

Uremic encephalopathy (UE) is a well-known complication of uremia, but its pathophysiology remains unknown. It is widely reported that in UE, the bilateral basal ganglia (BG) shows hyperintensities on T2/fluid attenuated inversion recovery magnetic resonance imaging (MRI), but cerebellar lesions are extremely rare, with to the best of our knowledge, only one case reported to date. We describe the findings from computed tomography and MRI for typical BG and cerebellar vermis lesions.

Recovery after exercise in the heat--factors influencing fluid intake

Science.gov (United States)

Mack, G. W.

1998-01-01

The restoration of body fluid balance following dehydration induced by exercise will occur through regulatory responses which stimulate ingestion of water and sodium ions. A number of different afferent signalling systems are necessary to generate appropriate thirst or sodium appetite. The primary sensory information of naturally occurring thirst is derived from receptors sensing cell volume and the volume of the extracellular fluid compartment. Sensory information from the oropharyngeal region is also an important determinant of thirst. The interaction of these various afferent signalling systems within the central nervous system determines the extent of fluid replacement following dehydration.

The reliability of magnetic resonance imaging in traumatic brain injury lesion detection

NARCIS (Netherlands)

Geurts, B.H.J.; Andriessen, T.M.J.C.; Goraj, B.M.; Vos, P.E.

2012-01-01

Objective: This study compares inter-rater-reliability, lesion detection and clinical relevance of T2-weighted imaging (T2WI), Fluid Attenuated Inversion Recovery (FLAIR), T2*-gradient recalled echo (T2*-GRE) and Susceptibility Weighted Imaging (SWI) in Traumatic Brain Injury (TBI). Methods: Three

The Morel-Lavallée lesion revisited: management in spinopelvic dissociation.

Science.gov (United States)

Dodwad, Shah Nawaz M; Niedermeier, Steven R; Yu, Elizabeth; Ferguson, Tania A; Klineberg, Eric O; Khan, Safdar N

2015-06-01

The Morel-Lavallée lesion occurs from a compression and shear force that usually separates the skin and subcutaneous tissue from the underlying muscular fascia. A dead space is created that becomes filled with blood, liquefied fat, and lymphatic fluid from the shearing of vasculature and lymphatics. If not treated appropriately, these lesions can become infected, cause tissue necrosis, or form chronic seromas. To review appropriate identification and treatment of Morel-Lavallée lesions in spinopelvic dissociation patients. Uncontrolled case series. Retrospective review of medical records. No funding was received in support of this study. The authors report no conflicts of interest. We present four cases of patients with traumatic spinopelvic dissociation. All had concomitant lumbosacral Morel-Lavallée lesions. All four trauma patients suffered traumatic spinopelvic dissociation with concomitant lumbosacral Morel-Lavallée lesions. Appropriate treatment included irrigation and debridement, drainage, antibiotics, and vacuum-assisted wound closure. Our series reflects an association of Morel-Lavallée lesion in spinopelvic dissociation trauma patients. Possibly, the rotatory injury that occurs at the spinopelvic junction creates a shear force to form the Morel-Lavallée lesion. When presented with a spinopelvic dissociation patient, one should be prepared to treat a Morel-Lavallée lesion. Copyright © 2015 Elsevier Inc. All rights reserved.

Multi-output decision trees for lesion segmentation in multiple sclerosis

Science.gov (United States)

Jog, Amod; Carass, Aaron; Pham, Dzung L.; Prince, Jerry L.

2015-03-01

Multiple Sclerosis (MS) is a disease of the central nervous system in which the protective myelin sheath of the neurons is damaged. MS leads to the formation of lesions, predominantly in the white matter of the brain and the spinal cord. The number and volume of lesions visible in magnetic resonance (MR) imaging (MRI) are important criteria for diagnosing and tracking the progression of MS. Locating and delineating lesions manually requires the tedious and expensive efforts of highly trained raters. In this paper, we propose an automated algorithm to segment lesions in MR images using multi-output decision trees. We evaluated our algorithm on the publicly available MICCAI 2008 MS Lesion Segmentation Challenge training dataset of 20 subjects, and showed improved results in comparison to state-of-the-art methods. We also evaluated our algorithm on an in-house dataset of 49 subjects with a true positive rate of 0.41 and a positive predictive value 0.36.

A mixed markers and volume-of-fluid method for the reconstruction and advection of interfaces in two-phase and free-boundary flows

International Nuclear Information System (INIS)

Aulisa, Eugenio; Manservisi, Sandro; Scardovelli, Ruben

2003-01-01

In this work we present a new mixed markers and volume-of-fluid (VOF) algorithm for the reconstruction and advection of interfaces in the two-dimensional space. The interface is described by using both the volume fraction function C, as in VOF methods, and surface markers, which locate the interface within the computational cells. The C field and the markers are advected by following the streamlines. New markers are determined by computing the intersections of the advected interface with the grid lines, then other markers are added inside each cut cell to conserve the volume fraction C. A smooth motion of the interface is obtained, typical of the marker approach, with a good volume conservation, as in standard VOF methods. In this article we consider a few typical two-dimensional tests and compare the results of the mixed algorithm with those obtained with VOF methods. Translations, rotations and vortex tests are performed showing that many problems of the VOF technique can be solved and a good accuracy in the geometrical motion and mass conservation can be achieved

Lesion volume predicts prostate cancer risk and aggressiveness: validation of its value alone and matched with prostate imaging reporting and data system score.

Science.gov (United States)

Martorana, Eugenio; Pirola, Giacomo Maria; Scialpi, Michele; Micali, Salvatore; Iseppi, Andrea; Bonetti, Luca Reggiani; Kaleci, Shaniko; Torricelli, Pietro; Bianchi, Giampaolo

2017-07-01

To demonstrate the association between magnetic resonance imaging (MRI) estimated lesion volume (LV), prostate cancer detection and tumour clinical significance, evaluating this variable alone and matched with Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) score. We retrospectively analysed 157 consecutive patients, with at least one prior negative systematic prostatic biopsy, who underwent transperineal prostate MRI/ultrasonography fusion-targeted biopsy between January 2014 and February 2016. Suspicious lesions were delineated using a 'region of interest' and the system calculated prostate volume and LV. Patients were divided in groups considering LV (≤0.5, 0.5-1, ≥1 mL) and PI-RADS score (1-5). We considered clinically significant prostate cancer as all cancers with a Gleason score of ≥3 + 4 as suggested by PI-RADS v2. A direct comparison between MRI estimated LV (MRI LV) and histological tumour volume (HTV) was done in 23 patients who underwent radical prostatectomy during the study period. Differences between MRI LV and HTV were assessed using the paired sample t-test. MRI LV and HTV concordance was verified using a Bland-Altman plot. The chi-squared test and logistic and ordinal regression models were used to evaluate difference in frequencies. The MRI LV and PI-RADS score were associated both with prostate cancer detection (both P prostate cancer detection (P Prostate cancer detection was 1.4-times higher for LVs of 0.5-1 mL and 1.8-times higher for LVs of ≥1 mL; significant prostate cancer detection was 2.6-times for LVs of 0.5-1 mL and 4-times for LVs of ≥1 mL. There was a positive correlation between MRI LV and HTV (r = 0.9876, P prostate cancer detection and with tumour clinical significance. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.

Clinics in diagnostic imaging (164). Morel-Lavallée lesion.

Science.gov (United States)

Cheong, Sook Chuei Wendy; Wong, Bak Siew Steven

2016-01-01

A 31-year-old male motorcyclist presented with prepatellar swelling of the left knee after a collision with a car. Magnetic resonance imaging of the knee showed no bony or ligamentous injury to the knee. Instead, a well-defined, thin-walled, T2-weighted hyperintense fluid collection with internal septations was identified in a prefascial location overlying the left patella and patellar tendon. The findings were in keeping with those of a Morel-Lavallée lesion, a closed internal degloving injury. Morel-Lavallée lesions are occasionally encountered after a blunt soft-tissue trauma. The presentation and imaging features are discussed. Copyright © Singapore Medical Association.

Microfluidic device and method for focusing, segmenting, and dispensing of a fluid stream

Science.gov (United States)

Jacobson, Stephen C [Knoxville, TN; Ramsey, J Michael [Knoxville, TN

2008-09-09

A microfluidic device and method for forming and dispensing minute volume segments of a material are described. In accordance with the present invention, a microfluidic device and method are provided for spatially confining the material in a focusing element. The device is also adapted for segmenting the confined material into minute volume segments, and dispensing a volume segment to a waste or collection channel. The device further includes means for driving the respective streams of sample and focusing fluids through respective channels into a chamber, such that the focusing fluid streams spatially confine the sample material. The device may also include additional means for driving a minute volume segment of the spatially confined sample material into a collection channel in fluid communication with the waste reservoir.

Studies on improvement of diagnosis of neurosurgical lesions by computed tomography, 2. On low-density findings in brain tumors and those in brain edema particularly

Energy Technology Data Exchange (ETDEWEB)

Hirata, T [Gifu Univ. (Japan). Faculty of Medicine

1980-09-01

CT findings of low-density in brain tumor cases were classified into the following 2 groups. (a) low-density lesions within brain tumor, masses. (b) low-density lesions surrounding brain tumors. Group (a) represented either fluid-containing cysts, necrotic masses or low-density tumor parenchyme, as confirmed by operative findings. it was impossible to diagnose pathological nature of low-density lesions merely by analyzing their Hounsfield No. (H-No.), excepting epidermoid, teratoma and arachnoid cyst, in which H-No. was essential for diagnosis. Group (b) was classified into 4 subgroups (grade 0 to III) by modifying Kazner's CT classification of brain edema. In most of malignant tumors (such as glioblastomas, metastatic tumors), wide peritumoral low-density lesions were observed. For example, peritumoral low-density lesions of grade III or II were observed in 87% of glioblastoma cases. But, peritumoral low-density lesions of grade II or III were observed also in benign tumor cases, i.e. in 50% of meningioma cases. In a case of astrocytoma, it was impossible to detect the border of the tumor and perifocal edema, even by means of contrast enhancement. It was confirmed by operative findings, that peritumoral low-density lesions could be caused not only brain edema, but also by enlarged peritumoral subarachnoid space or brain demyelinization due to compression by the tumor. In clinical cases, showing brain edema by CT, and in dogs, in which brain edema was produced by cold injury, the author observed that mean values of H-No. in the region of interest on the lesion side significantly increased after intravenous administration of 10% glycerol solution. It was considered that the observed increase in H-No. was caused by dehydration of the edematous brain and increase in regional cerebral blood volume.

Volume comparison of radiofrequency ablation at 3- and 5-cm target volumes for four different radiofrequency generators: MR volumetry in an open 1-T MRI system versus macroscopic measurement.

Science.gov (United States)

Rathke, Hendrik; Hamm, Bernd; Guettler, Felix; Lohneis, Philipp; Stroux, Andrea; Suttmeyer, Britta; Jonczyk, Martin; Teichgräber, Ulf; de Bucourt, Maximilian

2015-12-01

In a patient, it is usually not macroscopically possible to estimate the non-viable volume induced by radiofrequency ablation (RFA) after the procedure. The purpose of this study was to use an ex vivo bovine liver model to perform magnetic resonance (MR) volumetry of the visible tissue signal change induced by RFA and to correlate the MR measurement with the actual macroscopic volume measured in the dissected specimens. Sixty-four liver specimens cut from 16 bovine livers were ablated under constant simulated, close physiological conditions with target volumes set to 14.14 ml (3-cm lesion) and 65.45 ml (5-cm lesion). Four commercially available radiofrequency (RF) systems were tested (n=16 for each system; n=8 for 3 cm and n=8 for 5 cm). A T1-weighted turbo spin echo (TSE) sequence with inversion recovery and a proton-density (PD)-weighted TSE sequence were acquired in a 1.0-T open magnetic resonance imaging (MRI) system. After manual dissection, actual macroscopic ablation diameters were measured and volumes calculated. MR volumetry was performed using a semiautomatic software tool. To validate the correctness and feasibility of the volume formula in macroscopic measurements, MR multiplanar reformation diameter measurements with subsequent volume calculation and semiautomatic MR volumes were correlated. Semiautomatic MR volumetry yielded smaller volumes than manual measurement after dissection, irrespective of RF system used, target lesion size, and MR sequence. For the 3-cm lesion, only 43.3% (T1) and 41.5% (PD) of the entire necrosis are detectable. For the 5-cm lesion, only 40.8% (T1) and 37.2% (PD) are visualized in MRI directly after intervention. The correlation between semiautomatic MR volumes and calculated MR volumes was 0.888 for the T1-weighted sequence and 0.875 for the PD sequence. After correlation of semiautomatic MR volumes and calculated MR volumes, it seems reasonable to use the respective volume formula for macroscopic volume calculation

Prediction of quantitative intrathoracic fluid volume to diagnose pulmonary oedema using LabVIEW.

Science.gov (United States)

Urooj, Shabana; Khan, M; Ansari, A Q; Lay-Ekuakille, Aimé; Salhan, Ashok K

2012-01-01

Pulmonary oedema is a life-threatening disease that requires special attention in the area of research and clinical diagnosis. Computer-based techniques are rarely used to quantify the intrathoracic fluid volume (IFV) for diagnostic purposes. This paper discusses a software program developed to detect and diagnose pulmonary oedema using LabVIEW. The software runs on anthropometric dimensions and physiological parameters, mainly transthoracic electrical impedance (TEI). This technique is accurate and faster than existing manual techniques. The LabVIEW software was used to compute the parameters required to quantify IFV. An equation relating per cent control and IFV was obtained. The results of predicted TEI and measured TEI were compared with previously reported data to validate the developed program. It was found that the predicted values of TEI obtained from the computer-based technique were much closer to the measured values of TEI. Six new subjects were enrolled to measure and predict transthoracic impedance and hence to quantify IFV. A similar difference was also observed in the measured and predicted values of TEI for the new subjects.

Background based Gaussian mixture model lesion segmentation in PET

Energy Technology Data Exchange (ETDEWEB)

Soffientini, Chiara Dolores, E-mail: chiaradolores.soffientini@polimi.it; Baselli, Giuseppe [DEIB, Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133 (Italy); De Bernardi, Elisabetta [Department of Medicine and Surgery, Tecnomed Foundation, University of Milano—Bicocca, Monza 20900 (Italy); Zito, Felicia; Castellani, Massimo [Nuclear Medicine Department, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, via Francesco Sforza 35, Milan 20122 (Italy)

2016-05-15

Purpose: Quantitative {sup 18}F-fluorodeoxyglucose positron emission tomography is limited by the uncertainty in lesion delineation due to poor SNR, low resolution, and partial volume effects, subsequently impacting oncological assessment, treatment planning, and follow-up. The present work develops and validates a segmentation algorithm based on statistical clustering. The introduction of constraints based on background features and contiguity priors is expected to improve robustness vs clinical image characteristics such as lesion dimension, noise, and contrast level. Methods: An eight-class Gaussian mixture model (GMM) clustering algorithm was modified by constraining the mean and variance parameters of four background classes according to the previous analysis of a lesion-free background volume of interest (background modeling). Hence, expectation maximization operated only on the four classes dedicated to lesion detection. To favor the segmentation of connected objects, a further variant was introduced by inserting priors relevant to the classification of neighbors. The algorithm was applied to simulated datasets and acquired phantom data. Feasibility and robustness toward initialization were assessed on a clinical dataset manually contoured by two expert clinicians. Comparisons were performed with respect to a standard eight-class GMM algorithm and to four different state-of-the-art methods in terms of volume error (VE), Dice index, classification error (CE), and Hausdorff distance (HD). Results: The proposed GMM segmentation with background modeling outperformed standard GMM and all the other tested methods. Medians of accuracy indexes were VE <3%, Dice >0.88, CE <0.25, and HD <1.2 in simulations; VE <23%, Dice >0.74, CE <0.43, and HD <1.77 in phantom data. Robustness toward image statistic changes (±15%) was shown by the low index changes: <26% for VE, <17% for Dice, and <15% for CE. Finally, robustness toward the user-dependent volume initialization was

Nonpancreatic pseudocyst with fat-fluid level: a case report

International Nuclear Information System (INIS)

La, Youn Jong; Choi, Gyo Chang; Koh, Eun Suk

2000-01-01

Nonpancreatic pseudocyst is a rare lesion, with a specific fat-fluid level in the cyst. It is found among all age groups. The condition has been previously reported in foreign but not in domestic journals; we now describe one such case. (author)

A simple method of injecting tumescent fluid for liposuction

Directory of Open Access Journals (Sweden)

Arindam Sarkar

2011-01-01

Full Text Available Injection of tumescent fluid is essential to obtain a painless and relatively bloodless liposuction. There are many methods of injecting the tumescent fluid like power pumps, syringes and pressure cuffs. Our method consists of applying air pressure within the plastic transfusion fluid bottle by pricking with a wide bore needle and connecting it to a sphygmomanometer balloon pump. By inflation of the balloon pump and thus increasing pressure inside the plastic bottle, the rate and volume of infusion can be controlled. By applying the cuff outside the bottle the visibility inside is impaired and the bottle gets collapsed preventing a continued pressure and thereby impairing both the quantity as well as the rate of infusion. Power pumps are expensive. This method is inexpensive, infused volume of fluid being visible and the rate of infusion controllable.

Radioguided breast surgery for occult lesion localization – correlation between two methods

Directory of Open Access Journals (Sweden)

Gutfilen Bianca

2008-08-01

Full Text Available Abstract Background The detection of sub-clinical breast lesions has increased with screening mammography. Biopsy techniques can offer precision and agility in its execution, as well as patient comfort. This trial compares radioguided occult lesion localization (ROLL and wire-guided localization (WL of breast lesions. We investigate if a procedure at the ambulatorial level (ROLL could lead to a better aesthetic result and less postoperative pain. In addition, we intend to demonstrate the efficacy of radioguided localization and removal of occult breast lesions using radiopharmaceuticals injected directly into the lesions and correlate radiological and histopathological findings. Methods One hundred and twenty patients were randomized into two groups (59 WL and 61 ROLL. The patients were requested to score the cosmetic appearance of their breast after surgery, and a numerical rating scale was used to measure pain on the first postoperative day. Clearance margins were considered at ≥ 10 mm for invasive cancer, ≥ 5 mm for ductal carcinoma in situ, and ≥ 1 mm for benign disease. Patients were subsequently treated according to the definitive histological result. When appropriate, different statistical tests were used in order to test the significance between the two groups, considering a P value Results WL and ROLL located all the occult breast lesions successfully. In the ROLL group, the specimen volume was smaller and there were more cases with clear margins (P Conclusion ROLL is an effective method for the excision of non-palpable breast lesions. It enables more careful planning of the cutaneous incision, leading to better aesthetic results, less postoperative symptoms, and smaller volumes of excised tissue.

Essentials of fluid dynamics with applications to hydraulics, aeronautics, meteorology and other subjets

CERN Document Server

Prandtl, Ludwig

1953-01-01

Equilibrium of liquids and gases ; kinematics : dynamics of frictionless fluids ; motion of viscous fluids : turbulence : fluid resistance : practical applications ; flow with appreciable volume changes (dynamics of gases) ; miscellaneous topics.

Properties of forced convection experimental with silicon carbide based nano-fluids

Science.gov (United States)

Soanker, Abhinay

With the advent of nanotechnology, many fields of Engineering and Science took a leap to the next level of advancements. The broad scope of nanotechnology initiated many studies of heat transfer and thermal engineering. Nano-fluids are one such technology and can be thought of as engineered colloidal fluids with nano-sized colloidal particles. There are different types of nano-fluids based on the colloidal particle and base fluids. Nano-fluids can primarily be categorized into metallic, ceramics, oxide, magnetic and carbon based. The present work is a part of investigation of the thermal and rheological properties of ceramic based nano-fluids. alpha-Silicon Carbide based nano-fluid with Ethylene Glycol and water mixture 50-50% volume concentration was used as the base fluid here. This work is divided into three parts; Theoretical modelling of effective thermal conductivity (ETC) of colloidal fluids, study of Thermal and Rheological properties of alpha-SiC nano-fluids, and determining the Heat Transfer properties of alpha-SiC nano-fluids. In the first part of this work, a theoretical model for effective thermal conductivity (ETC) of static based colloidal fluids was formulated based on the particle size, shape (spherical), thermal conductivity of base fluid and that of the colloidal particle, along with the particle distribution pattern in the fluid. A MATLAB program is generated to calculate the details of this model. The model is specifically derived for least and maximum ETC enhancement possible and thereby the lower and upper bounds was determined. In addition, ETC is also calculated for uniform colloidal distribution pattern. Effect of volume concentration on ETC was studied. No effect of particle size was observed for particle sizes below a certain value. Results of this model were compared with Wiener bounds and Hashin- Shtrikman bounds. The second part of this work is a study of thermal and rheological properties of alpha-Silicon Carbide based nano-fluids

Oligoclonal bands in the cerebrospinal fluid and increased brain atrophy in early stages of relapsing-remitting multiple sclerosis

Directory of Open Access Journals (Sweden)

Juan Ignacio Rojas

2012-08-01

Full Text Available OBJECTIVE: To determine if the presence of oligoclonal bands (OB at early stages of multiple sclerosis was associated with higher brain atrophy, when compared with patients without OB. METHODS: Relapsing-remitting multiple sclerosis (RRMS patients with less than two years of disease onset and OB detection in cerebrospinal fluid (CSF were included. SIENAX was used for total brain volume (TBV, gray matter volume (GMV, and white matter volume (WMV. RESULTS: Forty patients were included, 29 had positive IgG-OB. No differences were found between positive and negative patients in gender, expanded disability status scale (EDSS, treatment received, and T2/T1 lesion load. TBV in positive IgG-OB patients was 1.5 mm³ x 10(6 compared with 1.64 mm³ x 10(6 in the negative ones (p=0.02. GMV was 0.51 mm³ x 10(6 in positive IgG-OB compared with 0.62 mm³ x 10(6 in negative ones (p=0.002. No differences in WMV (p=0.09 were seen. CONCLUSIONS: IgG-OB in the CSF was related to neurodegeneration magnetic resonance (MR markers in early RRMS.

The spectrum of benign esophageal lesions: imaging findings

International Nuclear Information System (INIS)

Jang, Kyung Mi; Lee, Kyung Soo; Lee, Soon Jin; Kim, Eun A; Kim, Tae Sung; Han, Dae Hee; Shim, Young Mog

2002-01-01

Benign esophageal lesions occur in various diseases. Barium studies are useful for the evaluation of mucosal surface lesions but provide little information about the extramucosal extent of disease. Computed tomography and magnetic resonance imaging, on the other hand, permit the assessment of wall thickness, mediastinal involvement, adjacent lymphadenopathy, and distant spread. In diseases such as fibrovascular polyps, duplication cysts, scleroderma, trauma, caustic esophagitis, hiatal hernia, esophageal diverticulum, achalasia, and paraesophageal varices, the findings of imaging studies are specific, obviating the need for further invasive diagnostic work-up. The advent of helical computed tomography and its volume data set allows the acquisition of multiplanar images, and magnetic resonance imaging is useful both for this and for tissue characterization. Thus, multiplanar cross-sectional imaging further extends the role of imaging modalities to the evaluation of benign esophageal lesions. Through an awareness of the multiplanar cross-sectional appearances of various benign esophageal lesions, the radiologist can play an important role in the detection, diagnosis, further diagnostic planning, and treatment of the diseases in which they occur

The spectrum of benign esophageal lesions: imaging findings

Energy Technology Data Exchange (ETDEWEB)

Jang, Kyung Mi; Lee, Kyung Soo; Lee, Soon Jin; Kim, Eun A; Kim, Tae Sung; Han, Dae Hee; Shim, Young Mog [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2002-09-01

Benign esophageal lesions occur in various diseases. Barium studies are useful for the evaluation of mucosal surface lesions but provide little information about the extramucosal extent of disease. Computed tomography and magnetic resonance imaging, on the other hand, permit the assessment of wall thickness, mediastinal involvement, adjacent lymphadenopathy, and distant spread. In diseases such as fibrovascular polyps, duplication cysts, scleroderma, trauma, caustic esophagitis, hiatal hernia, esophageal diverticulum, achalasia, and paraesophageal varices, the findings of imaging studies are specific, obviating the need for further invasive diagnostic work-up. The advent of helical computed tomography and its volume data set allows the acquisition of multiplanar images, and magnetic resonance imaging is useful both for this and for tissue characterization. Thus, multiplanar cross-sectional imaging further extends the role of imaging modalities to the evaluation of benign esophageal lesions. Through an awareness of the multiplanar cross-sectional appearances of various benign esophageal lesions, the radiologist can play an important role in the detection, diagnosis, further diagnostic planning, and treatment of the diseases in which they occur.

Deficit-Lesion Correlations in Syntactic Comprehension in Aphasia

Science.gov (United States)

Caplan, David; Michaud, Jennifer; Hufford, Rebecca; Makris, Nikos

2015-01-01

The effects of lesions on syntactic comprehension were studied in thirty one people with aphasia (PWA). Participants were tested for the ability to parse and interpret four types of syntactic structures and elements -- passives, object extracted relative clauses, reflexives and pronouns – in three tasks – object manipulation, sentence picture matching with full sentence presentation and sentence picture matching with self-paced listening presentation. Accuracy, end-of-sentence RT and self-paced listening times for each word were measured. MR scans were obtained and analyzed for total lesion volume and for lesion size in 48 cortical areas. Lesion size in several areas of the left hemisphere was related to accuracy in particular sentence types in particular tasks and to self-paced listening times for critical words in particular sentence types. The results support a model of brain organization that includes areas that are specialized for the combination of particular syntactic and interpretive operations and the use of the meanings produced by those operations to accomplish task-related operations. PMID:26688433

Deficit-lesion correlations in syntactic comprehension in aphasia.

Science.gov (United States)

Caplan, David; Michaud, Jennifer; Hufford, Rebecca; Makris, Nikos

2016-01-01

The effects of lesions on syntactic comprehension were studied in thirty-one people with aphasia (PWA). Participants were tested for the ability to parse and interpret four types of syntactic structures and elements - passives, object extracted relative clauses, reflexives and pronouns - in three tasks - object manipulation, sentence picture matching with full sentence presentation and sentence picture matching with self-paced listening presentation. Accuracy, end-of-sentence RT and self-paced listening times for each word were measured. MR scans were obtained and analyzed for total lesion volume and for lesion size in 48 cortical areas. Lesion size in several areas of the left hemisphere was related to accuracy in particular sentence types in particular tasks and to self-paced listening times for critical words in particular sentence types. The results support a model of brain organization that includes areas that are specialized for the combination of particular syntactic and interpretive operations and the use of the meanings produced by those operations to accomplish task-related operations. Copyright © 2015 Elsevier Inc. All rights reserved.

Brain washing : Transport of cerebral extracellular fluids and solutes

NARCIS (Netherlands)

Bedussi, B.

2017-01-01

Regulation of extracellular volume and fluid composition provides a robust microenvironment for brain cells. In peripheral tissue, fluid surplus and solutes are removed from the interstitium via drainage into lymphatic channels. Since the central nervous system lacks a proper lymphatic vasculature,

Flow dynamics of volume-heated boiling pools

International Nuclear Information System (INIS)

Ginsberg, T.; Jones, O.C.; Chen, J.C.

1979-01-01

Safety analyses of fast breeder reactors require understanding of the two-phase fluid dynamic and heat transfer characteristics of volume-heated boiling pool systems. Design of direct contact three-phase boilers, of practical interest in the chemical industries also requires understanding of the fundamental two-phase flow and heat transfer behavior of volume boiling systems. Several experiments have been recently reported relevant to the boundary heat-loss mechanisms of boiling pool systems. Considerably less is known about the two-phase fluid dynamic behavior of such systems. This paper describes an experimental investigation of the steady-state flow dynamics of volume-heated boiling pool systems

Fluid distribution kinetics during cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Mattias Törnudd

2014-08-01

Full Text Available OBJECTIVE: The purpose of this study was to examine the isovolumetric distribution kinetics of crystalloid fluid during cardiopulmonary bypass. METHODS: Ten patients undergoing coronary artery bypass grafting participated in this prospective observational study. The blood hemoglobin and the serum albumin and sodium concentrations were measured repeatedly during the distribution of priming solution (Ringer's acetate 1470 ml and mannitol 15% 200 ml and initial cardioplegia. The rate of crystalloid fluid distribution was calculated based on 3-min Hb changes. The preoperative blood volume was extrapolated from the marked hemodilution occurring during the onset of cardiopulmonary bypass. Clinicaltrials.gov: NCT01115166. RESULTS: The distribution half-time of Ringer's acetate averaged 8 minutes, corresponding to a transcapillary escape rate of 0.38 ml/kg/min. The intravascular albumin mass increased by 5.4% according to mass balance calculations. The preoperative blood volume, as extrapolated from the drop in hemoglobin concentration by 32% (mean at the beginning of cardiopulmonary bypass, was 0.6-1.2 L less than that estimated by anthropometric methods (p<0.02. The mass balance of sodium indicated a translocation from the intracellular to the extracellular fluid space in 8 of the 10 patients, with a median volume of 236 ml. CONCLUSIONS: The distribution half-time of Ringer's solution during isovolumetric cardiopulmonary bypass was 8 minutes, which is the same as for crystalloid fluid infusions in healthy subjects. The intravascular albumin mass increased. Most patients were hypovolemic prior to the start of anesthesia. Intracellular edema did not occur.

Towards a sharp-interface volume-of-fluid methodology for modeling evaporation

Science.gov (United States)

Pathak, Ashish; Raessi, Mehdi

2017-11-01

In modeling evaporation, the diffuse-interface (one-domain) formulation yields inaccurate results. Recent efforts approaching the problem via a sharp-interface (two-domain) formulation have shown significant improvements. The reasons behind their better performance are discussed in the present work. All available sharp-interface methods, however, exclusively employ the level-set. In the present work, we develop a sharp-interface evaporation model in a volume-of-fluid (VOF) framework in order to leverage its mass-conserving property as well as its ability to handle large topographical changes. We start with a critical review of the assumptions underlying the mathematical equations governing evaporation. For example, it is shown that the assumption of incompressibility can only be applied in special circumstances. The famous D2 law used for benchmarking is valid exclusively to steady-state test problems. Transient is present over significant lifetime of a micron-size droplet. Therefore, a 1D spherical fully transient model is developed to provide a benchmark transient solution. Finally, a 3D Cartesian Navier-Stokes evaporation solver is developed. Some preliminary validation test-cases are presented for static and moving drop evaporation. This material is based upon work supported by the Department of Energy, Office of Energy Efficiency and Renewable Energy and the Department of Defense, Tank and Automotive Research, Development, and Engineering Center, under Award Number DEEE0007292.

Spinning fluids in general relativity: a variational formulation

International Nuclear Information System (INIS)

Oliveira, H.P. de; Salim, J.M.

1990-01-01

In this paper we present a variational formulation for spinning fluids in General Relativity. In our model each volume element of the fluid has rigid microstructure. We deduce a symmetrical energy-moment tensor where there is an explicit contribution of kinetic spin energy to the total energy. (author)

Fluid therapy in neurotrauma: basic and clinical concepts

Directory of Open Access Journals (Sweden)

Hernando Raphael Alvis-Miranda

2014-01-01

Full Text Available The patient with head trauma is a challenge for the emergency physician and for the neurosurgeon. Currently traumatic brain injury constitutes a public health problem. Knowledge of the various therapeutic strategies to provide support in the prehospital and perioperative are essential for optimal care. Rapid infusion of large volumes of crystalloids to restore blood volume and blood pressure quickly is now the standard treatment for patients with combined TBI and HS The fluid in patients with brain and especially in the carrier of brain injury is a critical topic; we present a review of the literature about the history, physiology of current fluid preparations, and a discussion regard the use of fluid therapy in traumatic brain injury and decompressive craniectomy.http://dx.doi.org/10.7175/rhc.v5i1.636

Research into the Physiology of Cerebrospinal Fluid Reaches a New Horizon: Intimate Exchange between Cerebrospinal Fluid and Interstitial Fluid May Contribute to Maintenance of Homeostasis in the Central Nervous System.

Science.gov (United States)

Matsumae, Mitsunori; Sato, Osamu; Hirayama, Akihiro; Hayashi, Naokazu; Takizawa, Ken; Atsumi, Hideki; Sorimachi, Takatoshi

2016-07-15

Cerebrospinal fluid (CSF) plays an essential role in maintaining the homeostasis of the central nervous system. The functions of CSF include: (1) buoyancy of the brain, spinal cord, and nerves; (2) volume adjustment in the cranial cavity; (3) nutrient transport; (4) protein or peptide transport; (5) brain volume regulation through osmoregulation; (6) buffering effect against external forces; (7) signal transduction; (8) drug transport; (9) immune system control; (10) elimination of metabolites and unnecessary substances; and finally (11) cooling of heat generated by neural activity. For CSF to fully mediate these functions, fluid-like movement in the ventricles and subarachnoid space is necessary. Furthermore, the relationship between the behaviors of CSF and interstitial fluid in the brain and spinal cord is important. In this review, we will present classical studies on CSF circulation from its discovery over 2,000 years ago, and will subsequently introduce functions that were recently discovered such as CSF production and absorption, water molecule movement in the interstitial space, exchange between interstitial fluid and CSF, and drainage of CSF and interstitial fluid into both the venous and the lymphatic systems. Finally, we will summarize future challenges in research. This review includes articles published up to February 2016.

Role of Acute Lesion Topography in Initial Ischemic Stroke Severity and Long-Term Functional Outcomes.

Science.gov (United States)

Wu, Ona; Cloonan, Lisa; Mocking, Steven J T; Bouts, Mark J R J; Copen, William A; Cougo-Pinto, Pedro T; Fitzpatrick, Kaitlin; Kanakis, Allison; Schaefer, Pamela W; Rosand, Jonathan; Furie, Karen L; Rost, Natalia S

2015-09-01

Acute infarct volume, often proposed as a biomarker for evaluating novel interventions for acute ischemic stroke, correlates only moderately with traditional clinical end points, such as the modified Rankin Scale. We hypothesized that the topography of acute stroke lesions on diffusion-weighted magnetic resonance imaging may provide further information with regard to presenting stroke severity and long-term functional outcomes. Data from a prospective stroke repository were limited to acute ischemic stroke subjects with magnetic resonance imaging completed within 48 hours from last known well, admission NIH Stroke Scale (NIHSS), and 3-to-6 months modified Rankin Scale scores. Using voxel-based lesion symptom mapping techniques, including age, sex, and diffusion-weighted magnetic resonance imaging lesion volume as covariates, statistical maps were calculated to determine the significance of lesion location for clinical outcome and admission stroke severity. Four hundred ninety subjects were analyzed. Acute stroke lesions in the left hemisphere were associated with more severe NIHSS at admission and poor modified Rankin Scale at 3 to 6 months. Specifically, injury to white matter (corona radiata, internal and external capsules, superior longitudinal fasciculus, and uncinate fasciculus), postcentral gyrus, putamen, and operculum were implicated in poor modified Rankin Scale. More severe NIHSS involved these regions, as well as the amygdala, caudate, pallidum, inferior frontal gyrus, insula, and precentral gyrus. Acute lesion topography provides important insights into anatomic correlates of admission stroke severity and poststroke outcomes. Future models that account for infarct location in addition to diffusion-weighted magnetic resonance imaging volume may improve stroke outcome prediction and identify patients likely to benefit from aggressive acute intervention and personalized rehabilitation strategies. © 2015 American Heart Association, Inc.

The accuracy of MRI-determined synovial membrane and joint effusion volumes in arthritis. A comparison of pre- and post-aspiration volumes

DEFF Research Database (Denmark)

Østergaard, Mikkel; Stoltenberg, M; Henriksen, O

1995-01-01

Magnetic resonance imaging (MRI) of 18 knees of patients with arthritis was performed before and immediately after arthrocentesis. Pre- and post-aspiration volumes were calculated by adding the outlined areas of synovium/effusion from a continuous series of gadolinium-DTPA-enhanced 5 mm transversal...... T1-weighted MR-images. The difference between MRI-determined and syringe-determined volumes of aspirated joint fluid was 0-7 ml, median 2 ml, corresponding to 0-18%, median 7%, of the pre-aspiration effusion volume. Synovial membrane volumes, determined before and after arthrocentesis varied 0-10 ml......, median 3 ml (0-17%, median 7%). No significant systematic misinterpretation of the borderline between joint fluid and synovium was found. We conclude that effusion volumes and in all probability also synovial membrane volumes, can be determined by MRI with a maximal analytical error of approximately 20...

Volumes Learned: It Takes More Than Size to "Size Up" Pulmonary Lesions.

Science.gov (United States)

Ma, Xiaonan; Siegelman, Jenifer; Paik, David S; Mulshine, James L; St Pierre, Samantha; Buckler, Andrew J

2016-09-01

This study aimed to review the current understanding and capabilities regarding use of imaging for noninvasive lesion characterization and its relationship to lung cancer screening and treatment. Our review of the state of the art was broken down into questions about the different lung cancer image phenotypes being characterized, the role of imaging and requirements for increasing its value with respect to increasing diagnostic confidence and quantitative assessment, and a review of the current capabilities with respect to those needs. The preponderance of the literature has so far been focused on the measurement of lesion size, with increasing contributions being made to determine the formal performance of scanners, measurement tools, and human operators in terms of bias and variability. Concurrently, an increasing number of investigators are reporting utility and predictive value of measures other than size, and sensitivity and specificity is being reported. Relatively little has been documented on quantitative measurement of non-size features with corresponding estimation of measurement performance and reproducibility. The weight of the evidence suggests characterization of pulmonary lesions built on quantitative measures adds value to the screening for, and treatment of, lung cancer. Advanced image analysis techniques may identify patterns or biomarkers not readily assessed by eye and may also facilitate management of multidimensional imaging data in such a way as to efficiently integrate it into the clinical workflow. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors.

Directory of Open Access Journals (Sweden)

Gillian E Cooke

Full Text Available Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

International Conference on Mathematical Fluid Dynamics

CERN Document Server

Suzuki, Yukihito

2016-01-01

This volume presents original papers ranging from an experimental study on cavitation jets to an up-to-date mathematical analysis of the Navier-Stokes equations for free boundary problems, reflecting topics featured at the International Conference on Mathematical Fluid Dynamics, Present and Future, held 11–14 November 2014 at Waseda University in Tokyo. The contributions address subjects in one- and two-phase fluid flows, including cavitation, liquid crystal flows, plasma flows, and blood flows. Written by internationally respected experts, these papers highlight the connections between mathematical, experimental, and computational fluid dynamics. The book is aimed at a wide readership in mathematics and engineering, including researchers and graduate students interested in mathematical fluid dynamics.

Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting: Comparison of several anti-embolic protection devices.

Science.gov (United States)

Taha, Mahmoud M; Maeda, Masayuki; Sakaida, Hiroshi; Kawaguchi, Kenji; Toma, Naoki; Yamamoto, Akitaka; Hirose, Tomofumi; Miura, Youichi; Fujimoto, Masashi; Matsushima, Satoshi; Taki, Waro

2009-09-01

Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm(3) vs. 86.9 mm(3), respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm(3)) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm(3) and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions.

Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting. Comparison of several anti-embolic protection devices

International Nuclear Information System (INIS)

Taha, M.M.; Maeda, Masayuki; Sakaida, Hiroshi

2009-01-01

Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm 3 vs. 86.9 mm 3 , respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm 3 ) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm 3 and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions. (author)

Quantifying normal ankle joint volume: An anatomic study

Directory of Open Access Journals (Sweden)

Draeger Reid

2009-01-01

Full Text Available Background: Many therapeutic and diagnostic modalities such as intraarticular injections, arthrography and ankle arthroscopy require introduction of fluid into the ankle joint. Little data are currently available in the literature regarding the maximal volume of normal, nonpathologic, human ankle joints. The purpose of this study was to measure the volume of normal human ankle joints. Materials and Methods: A fluoroscopic guided needle was passed into nine cadaveric adult ankle joints. The needle was connected to an intracompartmental pressure measurement device. A radiopaque dye was introduced into the joint in 2 mL boluses, while pressure measurements were recorded. Fluid was injected into the joint until three consecutive pressure measurements were similar, signifying a maximal joint volume. Results: The mean maximum ankle joint volume was 20.9 ± 4.9 mL (range, 16-30 mL. The mean ankle joint pressure at maximum volume was 142.2 ± 13.8 mm Hg (range, 122-166 mm Hg. Two of the nine samples showed evidence of fluid tracking into the synovial sheath of the flexor hallucis longus tendon. Conclusion: Maximal normal ankle joint volume was found to vary between 16-30 mL. This study ascertains the communication between the ankle joint and the flexor hallucis longus tendon sheath. Exceeding maximal ankle joint volume suggested by this study during therapeutic injections, arthrography, or arthroscopy could potentially damage the joint.

Fluid responsiveness predicted by transcutaneous partial pressure of oxygen in patients with circulatory failure: a prospective study.