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Sample records for blood pool imaging

  1. Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

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    Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V. (Mt. Sinai Medical Center, New York, NY (USA))

    1989-09-01

    Blood-pool subtraction has been proposed to enhance {sup 111}In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging.

  2. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

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    Johnson, Joyce T. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Robinson, Joshua D. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Deng, Jie [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Rigsby, Cynthia K. [Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

    2016-12-15

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  3. Dynamic circular buffering: a technique for equilibrium gated blood pool imaging

    OpenAIRE

    1996-01-01

    We have devised a software technique called “dynamic circular buffering” (DCB) with which we create a gated blood pool image sequence of the heart in real time using the best features of LIST and FRAME mode methods of acquisition/processing. The routine is based on the concept of independent “agents” acting on the timing and position data continuously written into the DCB. This approach allows efficient asynchronous operation on PC-type machines and enhanced capability on systems capable of t...

  4. Morphology of drying blood pools

    Science.gov (United States)

    Laan, Nick; Smith, Fiona; Nicloux, Celine; Brutin, David; D-Blood project Collaboration

    2016-11-01

    Often blood pools are found on crime scenes providing information concerning the events and sequence of events that took place on the scene. However, there is a lack of knowledge concerning the drying dynamics of blood pools. This study focuses on the drying process of blood pools to determine what relevant information can be obtained for the forensic application. We recorded the drying process of blood pools with a camera and measured the weight. We found that the drying process can be separated into five different: coagulation, gelation, rim desiccation, centre desiccation, and final desiccation. Moreover, we found that the weight of the blood pool diminishes similarly and in a reproducible way for blood pools created in various conditions. In addition, we verify that the size of the blood pools is directly related to its volume and the wettability of the surface. Our study clearly shows that blood pools dry in a reproducible fashion. This preliminary work highlights the difficult task that represents blood pool analysis in forensic investigations, and how internal and external parameters influence its dynamics. We conclude that understanding the drying process dynamics would be advancement in timeline reconstitution of events. ANR funded project: D-Blood Project.

  5. Synthesis and characterization of PEGylated polyethylenimine-entrapped gold nanoparticles for blood pool and tumor CT imaging.

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    Zhou, Benqing; Zheng, Linfeng; Peng, Chen; Li, Du; Li, Jingchao; Wen, Shihui; Shen, Mingwu; Zhang, Guixiang; Shi, Xiangyang

    2014-10-08

    The synthesis and characterization of gold nanoparticles (AuNPs) entrapped within polyethylene glycol (PEG)-modified polyethylenimine (PEI) for blood pool and tumor computed tomography (CT) imaging are reported. In this approach, partially PEGylated PEI was used as a template for AuNP synthesis, followed by acetylating the PEI remaining surface amines. The synthesized PEGylated PEI-entrapped AuNPs (Au PENPs) were characterized via different methods. Our results reveal that the synthesized Au PENPs can be tuned to have an Au core size in a range of 1.9-4.6 nm and to be water-soluble, stable, and noncytotoxic in a studied concentration range. With a demonstrated better X-ray attenuation property than that of clinically used iodinated small molecular contrast agent (e.g., Omnipaque) and the prolonged half-decay time (11.2 h in rat) confirmed by pharmacokinetics studies, the developed PEGylated Au PENPs enabled efficient and enhanced blood pool CT imaging with imaging time up to 75 min. Likewise, thanks to the enhanced permeability and retention effect, the PEGylated Au PENPs were also able to be used as a contrast agent for effective CT imaging of a tumor model. With the proven organ biocompatibility by histological studies, the designed PEGylated Au PENPs may hold great promise to be used as contrast agents for CT imaging of a variety of biological systems. The significance of this study is that rather than the use of dendrimers as templates, cost-effective branched polymers (e.g., PEI) can be used as templates to generate functionalized AuNPs for CT imaging applications.

  6. Multimodality evaluation of ventricular function: comparison of cardiac magnetic resonance imaging, echocardiography, and planar and SPECT blood pool imaging

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    Feiglin, David H.; Krol, Andrzej; Tillapaugh-Fay, Gwen M.; Szeverenyi, Nikolaus M.; Thomas, Frank D.

    2001-05-01

    Fifteen patients underwent resting echocardiography (EC), ECG gated cardiac MR ventriculography (MRV) and blood pool planar and SPECT ventriculography (SPV) sequentially on the same day. In addition, 36 patients had sequential ECG gated blood pool and SPV and 20 normal volunteers, age > 18 years, had sequential ECG gated cardiac MRI performed on both Siemens closed, 1.5T, and open, 0.2T, magnets. Echocardiography was performed using a HP 5500 system equipped with an S4 transducer in 2D mode. MRV at 0.2T and 1.5T used a circular polarized body coil. Nuclear Medicine studies used 25 mCi Tc- 99m labeled red blood cells. Gated planar and SPV were acquired on a dual head Siemens E-Cam system. We have found that MRV affords the most accurate measurement of ventricular function. SPV and MRV provide similar estimations of left ventricular function (LVEF). Further, SPV consistently provides higher LVEF, as compared to the planar data simultaneously acquired. Observed significant differences in intermodality measurements indicate that follow up studies in patients, especially in patients whose management is critically dependent on functional measurement changes, should be monitored by one modality only.

  7. Detection of occult endoleaks after endovascular treatment of abdominal aortic aneurysm using magnetic resonance imaging with a blood pool contrast agent: preliminary observations.

    NARCIS (Netherlands)

    Cornelissen, Sandra; Prokop, M.; Verhagen, H.J.; Adriaensen, M.E.; Moll, F.L.; Bartels, L.W.

    2010-01-01

    OBJECTIVE: To determine whether blood pool contrast agent-enhanced magnetic resonance imaging (MRI) can visualize endoleaks that are occult on computed tomography (CT) in patients with nonshrinking aneurysms after endovascular aneurysm repair. MATERIALS AND METHODS: Written informed consent was obta

  8. Magnetic Particle / Magnetic Resonance Imaging: In-Vitro MPI-Guided Real Time Catheter Tracking and 4D Angioplasty Using a Road Map and Blood Pool Tracer Approach.

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    Johannes Salamon

    Full Text Available In-vitro evaluation of the feasibility of 4D real time tracking of endovascular devices and stenosis treatment with a magnetic particle imaging (MPI / magnetic resonance imaging (MRI road map approach and an MPI-guided approach using a blood pool tracer.A guide wire and angioplasty-catheter were labeled with a thin layer of magnetic lacquer. For real time MPI a custom made software framework was developed. A stenotic vessel phantom filled with saline or superparamagnetic iron oxide nanoparticles (MM4 was equipped with bimodal fiducial markers for co-registration in preclinical 7T MRI and MPI. In-vitro angioplasty was performed inflating the balloon with saline or MM4. MPI data were acquired using a field of view of 37.3×37.3×18.6 mm3 and a frame rate of 46 volumes/sec. Analysis of the magnetic lacquer-marks on the devices were performed with electron microscopy, atomic absorption spectrometry and micro-computed tomography.Magnetic marks allowed for MPI/MRI guidance of interventional devices. Bimodal fiducial markers enable MPI/MRI image fusion for MRI based roadmapping. MRI roadmapping and the blood pool tracer approach facilitate MPI real time monitoring of in-vitro angioplasty. Successful angioplasty was verified with MPI and MRI. Magnetic marks consist of micrometer sized ferromagnetic plates mainly composed of iron and iron oxide.4D real time MP imaging, tracking and guiding of endovascular instruments and in-vitro angioplasty is feasible. In addition to an approach that requires a blood pool tracer, MRI based roadmapping might emerge as a promising tool for radiation free 4D MPI-guided interventions.

  9. Polyphosphoric acid capping radioactive/upconverting NaLuF4:Yb,Tm,153Sm nanoparticles for blood pool imaging in vivo.

    Science.gov (United States)

    Peng, Juanjuan; Sun, Yun; Zhao, Lingzhi; Wu, Yongquan; Feng, Wei; Gao, Yanhong; Li, Fuyou

    2013-12-01

    Nanoparticles that circulate in the bloodstream for a prolonged period of time have important biomedicine applications. However, no example of lanthanide-based nanoparticles having a long-term circulation bloodstream has been reported to date. Herein, we report on difunctional radioactive and upconversion nanoparticles (UCNP) coated with polyphosphoric acid ligand, that is ethylenediamine tetramethylenephosphonic acid (EDTMP), for an application in single-photon emission computed tomography (SPECT) blood pool imaging. The structure, size and zeta-potential of the EDTMP-coated nanoparticles (EDTMP-UCNP) are verified using transmission electron microscopy and dynamic light scattering. Injection of radioisotope samarium-153-labeled EDTMP-UCNP (EDTMP-UCNP:(153)Sm) into mice reveal superior circulation time compared to control nanoparticles coated with citric acid (cit-UCNP:(153)Sm) and (153)Sm complex of EDTMP (EDTMP-(153)Sm). The mechanism for the extended circulation time may be attributed to the adhesion of EDTMP-UCNP on the membrane of red blood cells (RBCs). In vivo toxicity results show no toxicity of EDTMP-UCNP at the dose of 100 mg/kg, validating its safety as an agent for blood pool imaging. Our results provide a new strategy of nanoprobe for a long-term circulation bloodstream by introducing polyphosphoric acid as surface ligand.

  10. Ultra High-Resolution In vivo Computed Tomography Imaging of Mouse Cerebrovasculature Using a Long Circulating Blood Pool Contrast Agent.

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    Starosolski, Zbigniew; Villamizar, Carlos A; Rendon, David; Paldino, Michael J; Milewicz, Dianna M; Ghaghada, Ketan B; Annapragada, Ananth V

    2015-05-18

    Abnormalities in the cerebrovascular system play a central role in many neurologic diseases. The on-going expansion of rodent models of human cerebrovascular diseases and the need to use these models to understand disease progression and treatment has amplified the need for reproducible non-invasive imaging methods for high-resolution visualization of the complete cerebral vasculature. In this study, we present methods for in vivo high-resolution (19 μm isotropic) computed tomography imaging of complete mouse brain vasculature. This technique enabled 3D visualization of large cerebrovascular networks, including the Circle of Willis. Blood vessels as small as 40 μm were clearly delineated. ACTA2 mutations in humans cause cerebrovascular defects, including abnormally straightened arteries and a moyamoya-like arteriopathy characterized by bilateral narrowing of the internal carotid artery and stenosis of many large arteries. In vivo imaging studies performed in a mouse model of Acta2 mutations demonstrated the utility of this method for studying vascular morphometric changes that are practically impossible to identify using current histological methods. Specifically, the technique demonstrated changes in the width of the Circle of Willis, straightening of cerebral arteries and arterial stenoses. We believe the use of imaging methods described here will contribute substantially to the study of rodent cerebrovasculature.

  11. Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of cine Loop , Phase Analysis and Paradox Image -

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    Lee, Jae Tae; Kim, Gwang Weon; Lee, Kyu Bo; Chung, Byung Chun; Whang, Kee Suk; Chae, Sung Chul; Paek, Wee Hyun; Cheon, Jae Eun [Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, Hyong Woo; Chung, Jin Hong [Yeongnam National University College of Medicine, Daegu (Korea, Republic of)

    1990-07-15

    Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows:1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were is chemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5), pericardial effusion(5), post cardiac surgery(3), corpulmonale (2), endocarditis (l) and right ventricular tumor(l). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion (p <0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipulation respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical motions in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

  12. Validation of Perfusion Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent in Skeletal Swine Muscle.

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    Hindel, Stefan; Sauerbrey, Anika; Maaß, Marc; Maderwald, Stefan; Schlamann, Marc; Lüdemann, Lutz

    2015-01-01

    The purpose of our study was to validate perfusion quantification in a low-perfused tissue by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with shared k-space sampling using a blood pool contrast agent. Perfusion measurements were performed in a total of seven female pigs. An ultrasonic Doppler probe was attached to the right femoral artery to determine total flow in the hind leg musculature. The femoral artery was catheterized for continuous local administration of adenosine to increase blood flow up to four times the baseline level. Three different stable perfusion levels were induced. The MR protocol included a 3D gradient-echo sequence with a temporal resolution of approximately 1.5 seconds. Before each dynamic sequence, static MR images were acquired with flip angles of 5°, 10°, 20°, and 30°. Both static and dynamic images were used to generate relaxation rate and baseline magnetization maps with a flip angle method. 0.1 mL/kg body weight of blood pool contrast medium was injected via a central venous catheter at a flow rate of 5 mL/s. The right hind leg was segmented in 3D into medial, cranial, lateral, and pelvic thigh muscles, lower leg, bones, skin, and fat. The arterial input function (AIF) was measured in the aorta. Perfusion of the different anatomic regions was calculated using a one- and a two-compartment model with delay- and dispersion-corrected AIFs. The F-test for model comparison was used to decide whether to use the results of the one- or two-compartment model fit. Total flow was calculated by integrating volume-weighted perfusion values over the whole measured region. The resulting values of delay, dispersion, blood volume, mean transit time, and flow were all in physiologically and physically reasonable ranges. In 107 of 160 ROIs, the blood signal was separated, using a two-compartment model, into a capillary and an arteriolar signal contribution, decided by the F-test. Overall flow in hind leg muscles, as measured by the

  13. Validation of Perfusion Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent in Skeletal Swine Muscle.

    Directory of Open Access Journals (Sweden)

    Stefan Hindel

    Full Text Available The purpose of our study was to validate perfusion quantification in a low-perfused tissue by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI with shared k-space sampling using a blood pool contrast agent. Perfusion measurements were performed in a total of seven female pigs. An ultrasonic Doppler probe was attached to the right femoral artery to determine total flow in the hind leg musculature. The femoral artery was catheterized for continuous local administration of adenosine to increase blood flow up to four times the baseline level. Three different stable perfusion levels were induced. The MR protocol included a 3D gradient-echo sequence with a temporal resolution of approximately 1.5 seconds. Before each dynamic sequence, static MR images were acquired with flip angles of 5°, 10°, 20°, and 30°. Both static and dynamic images were used to generate relaxation rate and baseline magnetization maps with a flip angle method. 0.1 mL/kg body weight of blood pool contrast medium was injected via a central venous catheter at a flow rate of 5 mL/s. The right hind leg was segmented in 3D into medial, cranial, lateral, and pelvic thigh muscles, lower leg, bones, skin, and fat. The arterial input function (AIF was measured in the aorta. Perfusion of the different anatomic regions was calculated using a one- and a two-compartment model with delay- and dispersion-corrected AIFs. The F-test for model comparison was used to decide whether to use the results of the one- or two-compartment model fit. Total flow was calculated by integrating volume-weighted perfusion values over the whole measured region. The resulting values of delay, dispersion, blood volume, mean transit time, and flow were all in physiologically and physically reasonable ranges. In 107 of 160 ROIs, the blood signal was separated, using a two-compartment model, into a capillary and an arteriolar signal contribution, decided by the F-test. Overall flow in hind leg muscles

  14. Quantitative evaluation of MR perfusion imaging using blood pool contrast agent in subjects without pulmonary diseases and in patients with pulmonary embolism

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    Hansch, Andreas; Hinneburg, Uta [University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Jena (Germany); University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Gera (Germany); Kohlmann, Peter; Laue, Hendrik [Fraunhofer MEVIS - Institute for Medical Image Computing, Bremen (Germany); Boettcher, Joachim [SRH Klinikum Gera, Institute of Diagnostic and Interventional Radiology, Gera (Germany); Malich, Ansgar [Suedharzkrankenhaus Nordhausen, Institute of Diagnostic and Interventional Radiology, Nordhausen (Germany); Wolf, Gunter [University Hospital Jena, Department of Internal Medicine III, Jena (Germany); Pfeil, Alexander [University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Jena (Germany); University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Gera (Germany); University Hospital Jena, Department of Internal Medicine III, Jena (Germany)

    2012-08-15

    To assess the feasibility of time-resolved parallel three-dimensional magnetic resonance imaging (MRI) for quantitative analysis of pulmonary perfusion using a blood pool contrast agent. Quantitative perfusion analysis was performed using novel software to assess pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) in a quantitative manner. The evaluation of lung perfusion in the normal subjects showed an increase of PBF, PBV ventrally to dorsally (gravitational direction), and the highest values at the upper lobe, with a decrease to the middle and lower lobe (isogravitational direction). MTT showed no relevant changes in either the gravitational or isogravitational directions. In comparison with normally perfused lung areas (in diseased patients), the pulmonary embolism (PE) regions showed a significantly lower mean PBF (20 {+-} 0.6 ml/100 ml/min, normal region 94 {+-} 1 ml/100 ml/min; P < 0.001), mean PBV (2 {+-} 0.1 ml/100 ml, normal region 9.8 {+-} 0.1 ml/100 ml; P < 0.001) and mean MTT (3.8 {+-} 0.1 s; normal region 6.3 {+-} 0.1; P < 0.001). Our results demonstrate the feasibility of using time-resolved dynamic contrast-enhanced MRI to determine normal range and regional variation of pulmonary perfusion and perfusion deficits in patients with PE. (orig.)

  15. Gated blood-pool SPECT automated versus manual left ventricular function calculations

    NARCIS (Netherlands)

    Slart, RHJA; Poot, L; Piers, DA; van Veldhuisen, DJ; Nichols, K; Jager, PL

    2004-01-01

    Planar gated blood-pool imaging (GBPI) is a standard method for non-invasive assessment of left ventricular (LV) function. Gated blood-pool single photon emission computed tomographic (GBPS) data acquisition can be accomplished in the same time as GBPI, with the benefit of enabling visualization of

  16. Pictorial estimation of blood loss in a birthing pool--an aide memoire.

    Science.gov (United States)

    Goodman, Anushia

    2015-04-01

    The aim of this article is to share some photographic images to help midwives visually estimate blood loss at water births. PubMed, CINAHL and MEDLINE databases were searched for relevant research. There is little evidence to inform the practice of visually estimating blood loss in water, as discussed further on in the article. This article outlines a simulation where varying amounts of blood were poured into a birthing pool, captured by photo images. Photo images of key amounts like 150mls, 300mls and 450mls can be useful visual markers when estimating blood loss at water births. The speed of spread across the pool may be a significant factor in assessing blood loss. The author recommends that midwives and educators embark on similar simulations to inform their skill in estimating blood loss at water births.

  17. Level-Set Based Artery-Vein Separation in Blood Pool Agent CE-MR Angiograms

    NARCIS (Netherlands)

    Bemmel, van C.M.; Spreeuwers, L.J.; Viergever, M.A.; Niessen, W.J.

    2003-01-01

    Blood pool agents (BPAs) for contrast-enhanced (CE) magnetic-resonance angiography (MRA) allow prolonged imaging times for higher contrast and resolution. Imaging is performed during the steady state when the contrast agent is distributed through the complete vascular system. However, simultaneous v

  18. Magnetic resonance angiography with blood-pool contrast agents: future applications

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    Fink, C. [Univ. Hospitals, Grosshadern, Munich (Germany); Goyen, M. [Univ. Medical Center, Hamburg-Eppendorf, Hamburg (Germany); Lotz, J. [Hannover Medical School, Hannover (Germany)

    2007-03-15

    Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

  19. Weld pool vision sensing and image processing for GMAW

    Institute of Scientific and Technical Information of China (English)

    YUE Jianfeng; LI Liangyu; FAN Fanglei; WU Baolin

    2009-01-01

    It is difficult to acquire satisfied weld pool image by CCD sensor during gas metal arc welding(GMAW), for arc disturbs violently, welding current is great and working frequeacy is high. By using CMOS vision sensor to GMA W process, the vivid weld pool image is collected at any time, furthermore, whose gray compression ratio is controllable by sensor hardware circuit developed. Acquired weld pool image is firstly pre-processed by using Wiener filter and Ostu threshold segmentation algorithm. Subsequently separation between weld pool intage and cathode mist region is conducted by means of mathematical morphological algorithm, and the edge of weld pool image is extracted by using Prewitt algorithm.

  20. AMINO ACID BLOOD POOL OF CHILDREN WITH ALLERGIC DISEASES

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    Shmulich O. V.

    2014-01-01

    Full Text Available The amino acid blood pool of children with atopic dermatitis, bronchial asthma, urticaria, angioedema was investigated. The variability of blood plasma amino acid content (tryptophan, histidine, tyrosine, cysteine, methionine was observed. The changes of histidine and tryptophan levels might be connected with the formation of biogenic amines, such as histamine, serotonine, with take part in the development of allergic reactions and inflammatory processes in organism.

  1. Combined magnetic resonance imaging of deep venous thrombosis and pulmonary arteries after a single injection of a blood pool contrast agent

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    Hansch, Andreas; Neumann, Steffi; Baltzer, Pascal; Waginger, Matthias; Kaiser, Werner A.; Mentzel, Hans-Joachim [Friedrich-Schiller-University Jena, Institute of Diagnostic and Interventional Radiology, Jena (Germany); Betge, Stefan; Poehlmann, Gunther [Friedrich-Schiller-University Jena, Department of Internal Medicine I, Jena (Germany); Pfeil, Alexander; Wolf, Gunter [Friedrich-Schiller-University Jena, Department of Internal Medicine III, Jena (Germany); Boettcher, Joachim [SRH Klinikum Gera, Institute of Diagnostic and Interventional Radiology, Gera (Germany)

    2011-02-15

    Agreement rate between magnetic resonance imaging (MRI) and Doppler ultrasound (DUS) for the detection of deep vein thrombosis (DVT) in the lower extremities was attempted by using the intravascular MRI contrast agent gadofosveset trisodium. The potential of this method to detect pulmonary embolism (PE) was also evaluated. Forty-three consecutive inpatients with ultrasound-confirmed DVT but no clinical signs of PE were prospectively enrolled in this feasibility study. MRI was performed after a single injection of gadofosveset trisodium. The pulmonary arteries were imaged using a 3D Fast Low Angle Shot (FLASH) gradient recalled echo sequence. Additionally, pulmonary arteries, abdominal veins, pelvic and leg veins were imaged using a fat-suppressed 3D gradient echo Volume Interpolated Breath-hold Examination (VIBE FS). Gadofosveset trisodium-enhanced MRI detected more thrombi in the pelvic region, upper leg and lower leg than the initial DUS. In addition, PE was detected in 16 of the 43 DVT patients (37%). This study shows the feasibility of a combined protocol for the MRI diagnosis of DVT and PE using gadofosveset trisodium. This procedure is not only more sensitive in detecting DVT compared to standard DUS, but is also able to detect PE in asymptomatic patients. (orig.)

  2. Gated blood pool scintigraphy in patients with valvular heart disease

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    Breuel, H.P.; Heusinger, J.H.; Hanisch, K.

    1984-10-01

    In 58 patients suffering from either stenosis or insufficiency of a single heart valve, gated blood pool scintigraphy was performed to determine the ejection fraction as well as the peak filling and peak ejection rates. It could be demonstrated that in patients with valvular disorders the ejection fraction was only moderately decreased, generally remaining in the lower reference range. The peak filling and ejection rates showed no pathologic changes with the exception of patients with aortic regurgitation where these rates were significantly decreased. Thus, the estimation of left ventricular peak filling and ejection rates may permit diagnosis of myocardial impairment in patients with valvular disease even under resting conditions.

  3. Two-phase whole-body skeletal scintigraphy in children--revisiting the usefulness of the early blood pool phase.

    Science.gov (United States)

    Kwatra, Neha; Shalaby-Rana, Eglal; Majd, Massoud

    2013-10-01

    The usefulness of whole-body blood pool imaging as part of Tc-99m methylene diphosphonate (MDP) skeletal scintigraphy in detection of marrow infiltrative processes and unexpected soft-tissue and visceral abnormalities is demonstrated via illustrative case examples. Technical aspects of this simple and fast scanning technique are also highlighted.

  4. NEW VISUAL PERCEPTUAL POOLING STRATEGY FOR IMAGE QUALITY ASSESSMENT

    Institute of Scientific and Technical Information of China (English)

    Zhou Wujie; Jiang Gangyi; Yu Mei

    2012-01-01

    Most of Image Quality Assessment (IQA) metrics consist of two processes.In the first process,quality map of image is measured locally.In the second process,the last quality score is converted from the quality map by using the pooling strategy.The first process had been made effective and significant progresses,while the second process was always done in simple ways.In the second process of the pooling strategy,the optimal perceptual pooling weights should be determined and computed according to Human Visual System (HVS).Thus,a reliable spatial pooling mathematical model based on HVS is an important issue worthy of study.In this paper,a new Visual Perceptual Pooling Strategy (VPPS) for IQA is presented based on contrast sensitivity and luminance sensitivity of HVS.Experimental results with the LIVE database show that the visual perceptual weights,obtained by the proposed pooling strategy,can effectively and significantly improve the performances of the IQA metrics with Mean Structural SIMilarity (MSSIM) or Phase Quantization Code (PQC).It is confirmed that the proposed VPPS demonstrates promising results for improving the performances of existing IQA metrics.

  5. Gated blood-pool studies of cardiac function in the rat and marmoset

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    McIntosh, G.H.; Barnden, L.R.; Buttfield, I.H.; Charnock, J.S.

    1983-08-01

    To develop a sensitive, relatively noninvasive method for monitoring cardiac function in small laboratory animals, equilibrium gated blood-pool imaging (with Tc-99m RBC) was adapted for use in an inbred strain of laboratory rats of 400-470 g body weight and in marmosets of 320-400 g body weight. A 2-mm pinhole collimator was fitted to the gamma camera to produce a distinct image of the left ventricle following intravenous injection of 5 mCi of pertechnetate. Reproducible and consistent data for heart rate, left-ventricular ejection fraction, and peak ejection rate were obtained from studies on 13 male rats and five marmosets maintained on constant diets. An intravenous injection of 0.4 microgram of isoprenaline led to predictable increases in heart rate, left-ventricular ejection fraction, and peak ejection rate, and provided evidence of the sensitivity of the method in monitoring heart function in small laboratory animals.

  6. Gated blood-pool studies of cardiac function in the rat and marmoset

    Energy Technology Data Exchange (ETDEWEB)

    McIntosh, G.H. (CSIRO, Adelaide, South Australia); Barnden, L.R.; Buttfield, I.H.; Charnock, J.S.

    1983-08-01

    To develop a sensitive, relatively noninvasive method for monitoring cardiac function in small laboratory animals, equilibrium gated blood-pool imaging (with Tc-99m RBC) was adapted for use in an inbred strain of laboratory rats of 400 to 470 g body weight and in marmosets of 320 to 400 g body weight. A 2-mm pinhole collimator was fitted to the gamma camera to produce a distinct image of the left ventricle following intravenous injection of 5 mCi of pertechnetate. Reproducible and consistent data for heart rate, left-ventricular ejection fraction, and peak ejection rate were obtained from studies on 13 male rats and five marmosets maintained on constant diets. An intravenous injection of 0.4 ..mu..g of isoprenaline led to predictable increases in heart rate, left-ventricular ejection fraction, and peak ejection rate, and provided evidence of the sensitivity of the method in monitoring heart function in small laboratory animals.

  7. Measurement of Chloroform in Swimming Pools' Waters and Swimmers’ Blood

    Directory of Open Access Journals (Sweden)

    S Shegefti

    2009-12-01

    Full Text Available "nBackground: A new microextraction method named dispersive liquid-liquid microextraction (DLLME for determination of chloroform in pool water and blood of swimmers after swimming is described."nMethods: This method was performed based on coupling dispersive liquid-liquid microextraction (DLLME with gas chromatog­raphy-mass spectrometry (GC-MS. Methanol and trichloroethylenes were used as the disperser solvent and the extrac­tion solvents, respectively. The volumes of these solvents were optimized for pool water by central composite design. The study involved three indoor swimming pools and nine swimmers."nResults: Chloroform concentration of pool water was 118-135 µg L-1 and of blood ranged from 1.26 to 1.66 µg L-1."nConclusion: Indoor swimming pools are closed environments presenting detectable levels of trihalomethanes (THMs. Chloro­form (CHCl3 is the most represented THMs. Therefore, the presence of CHCl3 may be considered representative of the THMs. The new method DLLME was applied for determination of CHCl3 in pool water and blood of swimmers after swim­ming inside the indoor swimming pool. The method was optimized by experimental design. Chloroform concentra­tions in the specified pool waters were 135, 124, 118 µg L-1.

  8. Desiccation of a pool of blood: from fluid mechanics to forensic investigations

    Science.gov (United States)

    Nicloux, Celine; Brutin, David

    2012-11-01

    The evaporation of biological fluids (with droplet configuration) has been studied since a few years due to several applications in medical fields such as medical tests, drug screening, biostabilization... The evaporation of a drop of whole blood leads to the formation of final typical pattern of cracks. Flow motion, adhesion, gelation and fracturation all occur during the evaporation of this complex matter. During the drying, a sol-gel transition develops. The evaporation of a pool of blood is studied in order to link the pattern formation and the evaporation dynamics. We intend to transfer the knowledge acquired for drops on pool to improve the forensic investigations. In this study, we focus on both pool of blood and pure water to determine the transition region from drop to pool and then to characterize the evaporation rate in the pool configuration. The spreading of blood which can be seen as a complex fluid is strongly influenced the substrate nature. The initial contact angle of blood on different substrate nature will influence the maximum thickness of the layer and then will influence the evaporation mass flux. The authors gratefully acknowledge the help and the fruitful discussions raised with A. Boccoz.

  9. Prolonged in vivo circulation time by zwitterionic modification of magnetite nanoparticles for blood pool contrast agents.

    Science.gov (United States)

    Xiao, Wangchuan; Lin, Jiang; Li, Mingli; Ma, Yongjie; Chen, Yuxin; Zhang, Chunfu; Li, Dan; Gu, Hongchen

    2012-01-01

    Long circulation time is critical for blood pool contrast agents used in high-resolution magnetic resonance angiography. For iron oxide particle contrast agents, size and surface properties significantly influence their in vivo performance. We developed a novel long-circulating blood pool contrast agent by introducing zwitterionic structure onto the particle surface. Zwitterionic structure was fabricated by 3-(diethylamino)propylamine (DEAPA) grafted onto the surface of ployacrylic acid coated magnetite nanoparticles via EDC/NHS [N-(3-dimethylaminopropyl)-N'-ethylcarbo-diimide hydrochloride/N-hydroxysuccinimide] coupling chemistry. Zwitterionic particles demonstrated five times lower macrophage cell uptake than the original particles and low cell toxicity. Magnetic resonance angiography indicated that zwitterionic nanoparticles had much longer in vivo circulation time than the original particles and were an ideal candidate for blood pool contrast agent. We suppose that zwitterionic modification by DEAPA and EDC/NHS can be used generally for coating nanoparticles with carboxyl surface and to prolong their circulating time.

  10. Blood pooling in extrathoracic veins after glossopharyngeal insufflation

    DEFF Research Database (Denmark)

    Mijacika, Tanja; Frestad, Daria; Kyhl, Kasper

    2017-01-01

    PURPOSE: Trained breath-hold divers hyperinflate their lungs by glossopharyngeal insufflation (GPI) to prolong submersion time and withstand lung collapse at depths. Pulmonary hyperinflation leads to profound hemodynamic changes. METHODS: Thirteen divers performed preparatory breath-holds followed...... divers in a sub-study. RESULTS: After GPI, pulmonary volume increased by 0.8 ± 0.6 L above total lung capacity. The diameter of the superior caval (by 36 ± 17%) and intrathoracic part of the inferior caval vein decreased (by 21 ± 16%), while the diameters of the internal jugular (by 53 ± 34%), hepatic...... (by 28 ± 40%), abdominal part of the inferior caval (by 28 ± 28%), and femoral veins (by 65 ± 50%) all increased (P Blood volume of the internal jugular, the hepatic, the abdominal part of the inferior caval vein, and the combined common iliac and femoral veins increased by 145 ± 115, 80 ± 88...

  11. Evaluation of right ventricular function by NuSMUGA software : gated blood-pool SPECT vs. first-pass radionuclide angiography

    NARCIS (Netherlands)

    Slart, RHJA; Poot, L; Piers, DA; van Veldhuisen, DJ; Jager, PL

    2003-01-01

    Background: In comparison with planar imaging gated blood-pool single photon emission computed tomography (GBPS) has the advantage of separating left and right ventricle. The purpose of this investigation was to evaluate the right ventricular ejection fraction (RVEF) calculations by GBPS software ('

  12. Detection of bladder hemangioma in a child by blood-pool scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Ken; Saitoh, Masahiko; Chida, Shoichi [Department of Pediatrics, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka (Japan)

    2003-06-01

    Bladder hemangioma is a rare cause of gross hematuria. A 5-year-old boy was investigated for recurrent episodes of asymptomatic gross hematuria, but no abnormalities were found. Blood-pool scintigraphy using {sup 99m}technetium-human serum albumin combined with diethylene triamine penta-acetic acid (DTPA) revealed an area of increased activity in the right side of the bladder, which was confirmed by cystoscopy as a bladder hemangioma. Endoscopic laser therapy was used to remove two lesions successfully that were diagnosed histologically as cavernous hemangioma. The patient had no further episodes of hematuria in the 2-year period after this treatment. This case study indicates blood-pool scintigraphy may be a useful technique for detecting bladder hemangiomas. (orig.)

  13. Ventricular function during the acute rejection of heterotopic transplanted heart: Gated blood pool studies

    Energy Technology Data Exchange (ETDEWEB)

    Valette, H.; Bourguignon, M.H.; Desruennes, M.; Merlet, P.; Le Guludec, D. (Hopital de Bicetre, 94 - Le Kremlin-Bicetre (France). Lab. d' Explorations Cardiovasculaires CEA, 91 - Orsay (France). Service Hospitalier Frederic Joliot); Gregoire, M.C.; Agostini, D.; Rigaud, M.; Gandjbakhch, I.; Cabrol, A.; Cabrol, C. (Hopital La Pitie, 75 - Paris (France)); Syrota, A. (Hopital A. Pare, 92 - Boulogne (France))

    1991-11-01

    Twenty patients who had undergone a heterotopic heart transplant were studied prospectively to determine the relationship between rejection and ventricular dysfunction assessed from gated blood pool studies. A fully automated method for detecting ventricular edges was implemented; its success rate for the grafted left and right ventricles was 94% and 77%, respectively. The parameters, peak ejection and filling rates, were calculated pixel per pixel using a two-harmonic Fourier algorithm and then averaged over the ventricular region of interest. Peak filling and ejection rates were closely related with the severity of the rejection, while the left ventricular ejection fraction was not. Peak filling rates of both ventricles were the indices closely related to the presence of moderate rejection. Despite the low number of patients, these data suggested that gated blood pool derived indices of ventricular function are associated with ventricular dysfunction resulting from myocarditis rejection. Radionuclide ventriculography provides parametric data which are accurate and reliable for the diagnosis of rejection. (orig.).

  14. Right ventricular function in patients with mitral valve disease; Evaluation by radionuclide blood pool scan

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, Yoshio; Shimizu, Mitsuharu; Noriyasu, Toshiaki; Nakagawa, Tomio; Aono, Kaname; Yanagi, Hidekiyo; Seno, Yoshimasa; Teramoto, Shigeru; Nagaya, Isao (Okayama Univ. (Japan). School of Medicine)

    1989-10-01

    Right ventricular function was studied in 13 patients with mitral valve stenosis (MS), 10 patients with mitral valve regurgitation (MR) and 10 patients after mitral valve replacement (MVR) with radionuclide blood pool scan. In MS, right ventricular end-diastolic and end-systolic volumes were larger than MVR. In MR, right ventricular ejection fraction (RVEF) was smaller and right ventricular end-systolic volume was larger than MVR. In both MS and MR, there was no significant linear correlation between RVEF and mean pulmonary arterial pressure (mPAP) at rest, but during exercise RVEF of patients with elevated mPAP decreased more than that of patients with normal mPAP. RVEF in patients with MS and MR was significantly decreased during exercise, while that in patients after MVR showed no significant change. Radionuclide blood pool scan seems to be useful for the evaluation of right ventricular function in mitral valve disease. (author).

  15. Manage your blood sugar (image)

    Science.gov (United States)

    Checking your blood sugar levels often and writing down the results will tell you how well you are managing your diabetes so you ... possible. The best times to check your blood sugar are before meals and at bedtime. Your blood ...

  16. Is the gated blood pool scan useful for optimization of programmable cardiac pacemakers

    Energy Technology Data Exchange (ETDEWEB)

    Gunkel, H.; Otto, H.J.; Pundrich, R.; Mann, D.

    1986-08-01

    The significance of the ECG-triggered cardiac blood pool scan for optimization of physiological parameters of multiprogrammable cardiac pacemakers was investigated. Six patients were investigated, and two case reports are demonstrated in detail. By use of the quantitative evaluation of the parametric scans and other function parameters it is possible to evaluate cardiac function objectively in relation to the stimulation frequency and AV-delay using demand/delay pacemakers. These first results encourage the further use of this technique for evaluation of cardiac function in patients with programmable pacemakers.

  17. Genetic algorithm based image binarization approach and its quantitative evaluation via pooling

    Science.gov (United States)

    Hu, Huijun; Liu, Ya; Liu, Maofu

    2015-12-01

    The binarized image is very critical to image visual feature extraction, especially shape feature, and the image binarization approaches have been attracted more attentions in the past decades. In this paper, the genetic algorithm is applied to optimizing the binarization threshold of the strip steel defect image. In order to evaluate our genetic algorithm based image binarization approach in terms of quantity, we propose the novel pooling based evaluation metric, motivated by information retrieval community, to avoid the lack of ground-truth binary image. Experimental results show that our genetic algorithm based binarization approach is effective and efficiency in the strip steel defect images and our quantitative evaluation metric on image binarization via pooling is also feasible and practical.

  18. Comparison of blood pool and extracellular gadolinium chelate for functional MR evaluation of vascular thoracic outlet syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Ruth P., E-mail: ruthplim74@gmail.com [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Austin Health, Department of Radiology, Heidelberg, Victoria 3084 (Australia); The University of Melbourne, School of Medicine, Parkville, Victoria 3010 (Australia); Bruno, Mary, E-mail: mary.bruno@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Rosenkrantz, Andrew B., E-mail: Andrew.rosenkrantz@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Kim, Danny C., E-mail: danny.kim@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Mulholland, Thomas, E-mail: Thomas.mulholland@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Kwon, Jane, E-mail: jane.kwon@nyumc.org [New York University School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, 660 1st Avenue, New York, NY 10016 (United States); Palfrey, Amy P., E-mail: amy.pastva10@stjohns.edu [St John' s University, Department of Psychology, 8000 Utopia Parkway, Jamaica-Queens, NY 11439 (United States); Ogedegbe, Olugbenga, E-mail: Olugbenga.Ogedegbe@nyumc.org [New York University School of Medicine, Clinical and Translational Science Institute, 227 E30th St, 8th Floor, New York, NY 10016 (United States)

    2014-07-15

    Objective: To compare performance of single-injection blood pool agent (gadofosveset trisodium, BPA) against dual-injection extracellular contrast (gadopentetate dimeglumine, ECA) for MRA/MRV in assessment of suspected vascular TOS. Materials and methods: Thirty-one patients referred for vascular TOS evaluation were assessed with BPA (n = 18) or ECA (n = 13) MRA/MRV in arm abduction and adduction. Images were retrospectively assessed for: image quality (1 = non-diagnostic, 5 = excellent), vessel contrast (1 = same signal as muscle, 4 = much brighter than muscle) and vascular pathology by two independent readers, with a separate experienced reader providing reference assessment of vascular pathology. Results: Median image quality was diagnostic or better (score ≥3) for ECA and BPA at all time points, with BPA image quality superior at abduction late (BPA 4.5, ECA 4, p = 0.042) and ECA image quality superior at adduction-early (BPA 4.5; ECA 4.0, p = 0.018). High qualitative vessel contrast (mean score ≥3) was observed at all time points with both BPA and ECA, with superior BPA vessel contrast at abduction-late (BPA 3.97 ± 0.12; ECA 3.73 ± 0.26, p = 0.007) and ECA at adduction-early (BPA 3.42 ± 0.52; ECA 3.96 ± 0.14, p < 0.001). Readers readily identified arterial and venous pathology with BPA, similar to ECA examinations. Conclusion: Single-injection BPA MRA/MRV for TOS evaluation demonstrated diagnostic image quality and high vessel contrast, similar to dual-injection ECA imaging, enabling identification of fixed and functional arterial and venous pathology.

  19. Blood Pool Segmentation Results in Superior Virtual Cardiac Models than Myocardial Segmentation for 3D Printing.

    Science.gov (United States)

    Farooqi, Kanwal M; Lengua, Carlos Gonzalez; Weinberg, Alan D; Nielsen, James C; Sanz, Javier

    2016-08-01

    The method of cardiac magnetic resonance (CMR) three-dimensional (3D) image acquisition and post-processing which should be used to create optimal virtual models for 3D printing has not been studied systematically. Patients (n = 19) who had undergone CMR including both 3D balanced steady-state free precession (bSSFP) imaging and contrast-enhanced magnetic resonance angiography (MRA) were retrospectively identified. Post-processing for the creation of virtual 3D models involved using both myocardial (MS) and blood pool (BP) segmentation, resulting in four groups: Group 1-bSSFP/MS, Group 2-bSSFP/BP, Group 3-MRA/MS and Group 4-MRA/BP. The models created were assessed by two raters for overall quality (1-poor; 2-good; 3-excellent) and ability to identify predefined vessels (1-5: superior vena cava, inferior vena cava, main pulmonary artery, ascending aorta and at least one pulmonary vein). A total of 76 virtual models were created from 19 patient CMR datasets. The mean overall quality scores for Raters 1/2 were 1.63 ± 0.50/1.26 ± 0.45 for Group 1, 2.12 ± 0.50/2.26 ± 0.73 for Group 2, 1.74 ± 0.56/1.53 ± 0.61 for Group 3 and 2.26 ± 0.65/2.68 ± 0.48 for Group 4. The numbers of identified vessels for Raters 1/2 were 4.11 ± 1.32/4.05 ± 1.31 for Group 1, 4.90 ± 0.46/4.95 ± 0.23 for Group 2, 4.32 ± 1.00/4.47 ± 0.84 for Group 3 and 4.74 ± 0.56/4.63 ± 0.49 for Group 4. Models created using BP segmentation (Groups 2 and 4) received significantly higher ratings than those created using MS for both overall quality and number of vessels visualized (p printed on desktop 3D printers with good quality and accurate representation of the virtual 3D models. We recommend using BP segmentation with either MRA or bSSFP source datasets to create virtual 3D models for 3D printing. Desktop 3D printers can offer good quality printed models with accurate representation of anatomic detail.

  20. Diabetes and blood pressure (image)

    Science.gov (United States)

    People with diabetes have a higher risk for heart attacks and strokes. Your doctor or nurse should check your blood pressure ... People with diabetes have a higher risk for heart attacks and strokes. Your doctor or nurse should check your blood pressure ...

  1. Relaxivity of blood pool contrast agent depends on the host tissue as suggested by semianalytical simulations

    DEFF Research Database (Denmark)

    Jensen, Birgitte Fuglsang; Østergaard, Leif; Kiselev, Valerij G

    Concentration of MRI contrast agents (CA) is commonly determined indirectly using their relaxation effect. In quantitative perfusion studies, the change in the relaxation following a bolus passage is converted into concentrations assuming identical relaxivities for tissue and blood. Simulations...... can be applied to quantitation of perfusion, functional MRI and vessel size imaging...

  2. Red blood cells, spherocytosis (image)

    Science.gov (United States)

    Spherocytosis is a hereditary disorder of the red blood cells (RBCs), which may be associated with a mild anemia. Typically, the affected RBCs are small, spherically shaped, and lack the light centers seen ...

  3. Study on image acquisition in 3-D sensor system of arc welding pool surface shape using grating projection

    Science.gov (United States)

    Ai, Xiaopu; Liu, Nansheng; Wei, Yiqing; Hu, Xian; Wei, Sheng; Liu, Xiaorui

    2009-11-01

    Detecting 3-D information on welding pool surface shape is difficult due to the arc light interference, high temperature radiation and pool surface specular reflection. The characteristics of mirror like reflection on pool of liquid surface are studied. Besides the way to obtain clear information-rich image of the pool area is discussed under the strong arc light. Because of the strong arc light above the pool will affect the imaging of the relatively weaker laser stripes seriously, we need to choose a suitable shooting angle and shooting distance to achieve well image. According to all these factors, the optimal combination of the sensing structure parameters in theory is deduced. Based on this work, a vision detecting of arc welding pool surface topography system was putted up in our laboratory, also actual measurement was carried out to obtain more clear images of deformation laser stripes in welding pool. This will provide the three-dimensional reconstruction a strong support.

  4. Gd-AAZTA-MADEC, an improved blood pool agent for DCE-MRI studies on mice on 1 T scanners.

    Science.gov (United States)

    Longo, Dario Livio; Arena, Francesca; Consolino, Lorena; Minazzi, Paolo; Geninatti-Crich, Simonetta; Giovenzana, Giovanni Battista; Aime, Silvio

    2016-01-01

    A novel MRI blood-pool contrast agent (Gd-AAZTA-MADEC) has been compared with established blood pool agents for tumor contrast enhanced images and angiography. Synthesis, relaxometric properties, albumin binding affinity and pharmacokinetic profiles are reported. For in vivo studies, angiographic images and tumor contrast enhanced images were acquired on mice with benchtop 1T-MRI scanners and compared with MS-325, B22956/1 and B25716/1. The design of this contrast agent involved the elongation of the spacer between the targeting deoxycholic acid moiety and the Gd-AAZTA imaging reporting unit that drastically changed either the binding affinity to albumin (KA(HSA) = 8.3 × 10(5) M(-1)) and the hydration state of the Gd ion (q = 2) in comparison to the recently reported B25716/1. The very markedly high binding affinity towards mouse and human serum albumins resulted in peculiar pharmacokinetics and relaxometric properties. The NMRD profiles clearly indicated that maximum efficiency is attainable at magnetic field strength of 1 T. In vivo studies showed high enhancement of the vasculature and a prolonged accumulation inside tumor. The herein reported pre-clinical imaging studies show that a great benefit arises from the combination of a benchtop MRI scanner operating at 1 T and the albumin-binding Gd-AAZTA-MADEC complex, for pursuing enhanced angiography and improved characterization of tumor vascular microenvironment.

  5. Images of Blood in American Cinema

    DEFF Research Database (Denmark)

    Rødje, Kjetil

    Through studying images of blood in film from the mid-1950s to the end of the 1960s, this path-breaking book explores how blood as an (audio)visual cinematic element went from predominately operating as a signifier, providing audiences with information about a film’s plot and characters, to incre...

  6. Blood Pool Contrast-enhanced Magnetic Resonance Angiography with Correlation to Digital Subtraction Angiography: A Pictorial Review

    Directory of Open Access Journals (Sweden)

    Martha-Grace Knuttinen

    2014-01-01

    Full Text Available Magnetic resonance angiography (MRA provides noninvasive visualization of the vascular supply of soft tissue masses and vascular pathology, without harmful radiation. This is important for planning an endovascular intervention, and helps to evaluate the efficiency and effectiveness of the treatment. MRA with conventional extracellular contrast agents relies on accurate contrast bolus timing, limiting the imaging window to first-pass arterial phase. The recently introduced blood pool contrast agent (BPCA, gadofosveset trisodium, reversibly binds to human serum albumin, resulting in increased T1 relaxivity and prolonged intravascular retention time, permitting both first-pass and steady-state phase high-resolution imaging. In our practice, high-quality MRA serves as a detailed "roadmap" for the needed endovascular intervention. Cases of aortoiliac occlusive disease, inferior vena cava thrombus, pelvic congestion syndrome, and lower extremity arteriovenous malformation are discussed in this article. MRA was acquired at 1.5 T with an 8-channel phased array coil after intravenous administration of gadofosveset (0.03 mmol/kg body weight, at the first-pass phase. In the steady-state, serial T1-weighted 3D spoiled gradient echo images were obtained with high resolution. All patients underwent digital subtraction angiography (DSA and endovascular treatment. MRA and DSA findings of vascular anatomy and pathology are discussed and correlated. BPCA-enhanced MRA provides high-quality first-pass and steady-state vascular imaging. This could increase the diagnostic accuracy and create a detailed map for pre-intervention planning. Understanding the pharmacokinetics of BPCA and being familiar with the indications and technique of MRA are important for diagnosis and endovascular intervention.

  7. Identification of cytoskeletal elements enclosing the ATP pools that fuel human red blood cell membrane cation pumps.

    Science.gov (United States)

    Chu, Haiyan; Puchulu-Campanella, Estela; Galan, Jacob A; Tao, W Andy; Low, Philip S; Hoffman, Joseph F

    2012-07-31

    The type of metabolic compartmentalization that occurs in red blood cells differs from the types that exist in most eukaryotic cells, such as intracellular organelles. In red blood cells (ghosts), ATP is sequestered within the cytoskeletal-membrane complex. These pools of ATP are known to directly fuel both the Na(+)/K(+) and Ca(2+) pumps. ATP can be entrapped within these pools either by incubation with bulk ATP or by operation of the phosphoglycerate kinase and pyruvate kinase reactions to enzymatically generate ATP. When the pool is filled with nascent ATP, metabolic labeling of the Na(+)/K(+) or Ca(2+) pump phosphoproteins (E(Na)-P and E(Ca)-P, respectively) from bulk [γ-(32)P]-ATP is prevented until the pool is emptied by various means. Importantly, the pool also can be filled with the fluorescent ATP analog trinitrophenol ATP, as well as with a photoactivatable ATP analog, 8-azido-ATP (N(3)-ATP). Using the fluorescent ATP, we show that ATP accumulates and then disappears from the membrane as the ATP pools are filled and subsequently emptied, respectively. By loading N(3)-ATP into the membrane pool, we demonstrate that membrane proteins that contribute to the pool's architecture can be photolabeled. With the aid of an antibody to N(3)-ATP, we identify these labeled proteins by immunoblotting and characterize their derived peptides by mass spectrometry. These analyses show that the specific peptides that corral the entrapped ATP derive from sequences within β-spectrin, ankyrin, band 3, and GAPDH.

  8. Spatially pooled contrast responses predict neural and perceptual similarity of naturalistic image categories.

    Directory of Open Access Journals (Sweden)

    Iris I A Groen

    Full Text Available The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis. Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task.

  9. Acquisition and processing of coaxial image of molten pool and keyhole in Nd:YAG laser welding with high power

    Institute of Scientific and Technical Information of China (English)

    秦国梁; 齐秀滨; 杨永波; 王旭友; 林尚扬

    2004-01-01

    An experimental setup of acquiring the coaxial visual image of the molten pool and keyhole in high power Nd:YAG laser welding is introduced in this paper. It is one of the most difficult problems in acquiring coaxial image that the coaxial imaging signal of molten pool and keyhole must be separated from the laser beam with high power. This problem was resolved by designing a dichroitic spectroscope. The characteristics of imaging signal were analyzed and the coaxial image of molten pool and keyhole was acquired. A smoothing filter and a homomorphic filter were designed to remove the low frequency noise and to enhance the image according to the characteristics of imaging signal. At last, edges of molten pool and keyhole were detected and extracted based on image segmentation with threshold.

  10. Magnetic particle imaging of blood coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Murase, Kenya, E-mail: murase@sahs.med.osaka-u.ac.jp; Song, Ruixiao; Hiratsuka, Samu [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka 565-0871 (Japan)

    2014-06-23

    We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl{sub 2} to whole sheep blood mixed with magnetic nanoparticles (MNPs). The “MPI value” was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

  11. Magnetic particle imaging of blood coagulation

    Science.gov (United States)

    Murase, Kenya; Song, Ruixiao; Hiratsuka, Samu

    2014-06-01

    We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl2 to whole sheep blood mixed with magnetic nanoparticles (MNPs). The "MPI value" was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

  12. Generation of a pool of variable size symmetric keys through Image

    Directory of Open Access Journals (Sweden)

    Prerna Garg

    2011-10-01

    Full Text Available This paper introduces a new concept of the generation of a unending pool of keys through an image leaving behind the idea of sending keys every time for encryption and decryption. This can help in avoiding the problem of frequent key exchanges and the after affects associated with it. In this a single image is used to generate the various keys. Thus say ,if the image is of 2n bytes, taking n from 0 to any valid integer value gives a big pool of keys making it useful for any symmetric encryption technique,DES, AES, RC4, CAST, twofish, blowfish etc. This adds the advantage of one time usage of key andavoids the disadvantage of securing and sending it on the network.

  13. Relaxivity of blood pool contrast agent depends on the host tissue as suggested by semianalytical simulations

    DEFF Research Database (Denmark)

    Kjølby, Birgitte Fuglsang; Østergaard, Leif; Kiselev, Valerij

    Concentration of magnetic resonance imaging (MRI) contrast agents (CA) cannot be measured directly and is commonly determined indirectly using their relaxation effect. This requires knowledge of the relaxivity of the used CA. Quantitative perfusion studies involve measurement of CA concentration...... studies (3,4) as demonstrated in (5). It was previously found (6) that the perfusion measurements using dynamic susceptibility contrast inherently overestimate cerebral blood flow and volume. In view of the present result, this is attributed to the significant difference in the relaxivity of the CA...

  14. Image analysis of blood platelets adhesion.

    Science.gov (United States)

    Krízová, P; Rysavá, J; Vanícková, M; Cieslar, P; Dyr, J E

    2003-01-01

    Adhesion of blood platelets is one of the major events in haemostatic and thrombotic processes. We studied adhesion of blood platelets on fibrinogen and fibrin dimer sorbed on solid support material (glass, polystyrene). Adhesion was carried on under static and dynamic conditions and measured as percentage of the surface covered with platelets. Within a range of platelet counts in normal and in thrombocytopenic blood we observed a very significant decrease in platelet adhesion on fibrin dimer with bounded active thrombin with decreasing platelet count. Our results show the imperative use of platelet poor blood preparations as control samples in experiments with thrombocytopenic blood. Experiments carried on adhesive surfaces sorbed on polystyrene showed lower relative inaccuracy than on glass. Markedly different behaviour of platelets adhered on the same adhesive surface, which differed only in support material (glass or polystyrene) suggest that adhesion and mainly spreading of platelets depends on physical quality of the surface. While on polystyrene there were no significant differences between fibrin dimer and fibrinogen, adhesion measured on glass support material markedly differed between fibrin dimer and fibrinogen. We compared two methods of thresholding in image analysis of adhered platelets. Results obtained by image analysis of spreaded platelets showed higher relative inaccuracy than results obtained by image analysis of platelets centres and aggregates.

  15. Intraoperative cerebral blood flow imaging of rodents

    Science.gov (United States)

    Li, Hangdao; Li, Yao; Yuan, Lu; Wu, Caihong; Lu, Hongyang; Tong, Shanbao

    2014-09-01

    Intraoperative monitoring of cerebral blood flow (CBF) is of interest to neuroscience researchers, which offers the assessment of hemodynamic responses throughout the process of neurosurgery and provides an early biomarker for surgical guidance. However, intraoperative CBF imaging has been challenging due to animal's motion and position change during the surgery. In this paper, we presented a design of an operation bench integrated with laser speckle contrast imager which enables monitoring of the CBF intraoperatively. With a specially designed stereotaxic frame and imager, we were able to monitor the CBF changes in both hemispheres during the rodent surgery. The rotatable design of the operation plate and implementation of online image registration allow the technician to move the animal without disturbing the CBF imaging during surgery. The performance of the system was tested by middle cerebral artery occlusion model of rats.

  16. Hyperspectral Image Kernel Sparse Subspace Clustering with Spatial Max Pooling Operation

    Science.gov (United States)

    Zhang, Hongyan; Zhai, Han; Liao, Wenzhi; Cao, Liqin; Zhang, Liangpei; Pižurica, Aleksandra

    2016-06-01

    In this paper, we present a kernel sparse subspace clustering with spatial max pooling operation (KSSC-SMP) algorithm for hyperspectral remote sensing imagery. Firstly, the feature points are mapped from the original space into a higher dimensional space with a kernel strategy. In particular, the sparse subspace clustering (SSC) model is extended to nonlinear manifolds, which can better explore the complex nonlinear structure of hyperspectral images (HSIs) and obtain a much more accurate representation coefficient matrix. Secondly, through the spatial max pooling operation, the spatial contextual information is integrated to obtain a smoother clustering result. Through experiments, it is verified that the KSSC-SMP algorithm is a competitive clustering method for HSIs and outperforms the state-of-the-art clustering methods.

  17. Worldwide trends in blood pressure from 1975 to 2015 : a pooled analysis of 1479 population-based measurement studies with 19.1 million participants

    OpenAIRE

    Zhou, Bin; Bentham, James; Di Cesare, Mariachiara; Bixby, Honor; Danaei, Goodarz; Cowan, Melanie J.; Paciorek, Christopher J.; Singh, Gitanjali; Hajifathalian, Kaveh; James E Bennett; Taddei, Cristina; Bilano, Ver; Carrillo-Larco, Rodrigo M.; Djalalinia, Shirin; Khatibzadeh, Shahab

    2017-01-01

    Background Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher. Methods For this analysis, we pooled national, subnational, or community population-based studies that had measured ...

  18. Worldwide trends in blood pressure from 1975 to 2015: a pooled analysis of 1479 population-based measurement studies with 19.1 million participants

    OpenAIRE

    Zhou, Bin; Bentham, James; Di Cesare, Mariachiara; Bixby, Honor; Cowan, Melanie J.; Paciorek, Christopher J.; Singh, Gitanjali; Hajifathalian, Kaveh; James E Bennett; Taddei, Cristina; Bilano, Ver; Carrillo-Larco, Rodrigo M.; Khatibzadeh, Shahab; Lugero, Charles; Zhang, Wan Zhu

    2017-01-01

    Background Raised blood pressure is an important risk factor for cardiovascular diseases and chronic kidney disease. We estimated worldwide trends in mean systolic and mean diastolic blood pressure, and the prevalence of, and number of people with, raised blood pressure, defined as systolic blood pressure of 140 mm Hg or higher or diastolic blood pressure of 90 mm Hg or higher. Methods For this analysis, we pooled national, subnational, or community population-based studies that had measured ...

  19. Research for the method of image acquisition of the molten pool in the TIG welding of aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    王建军; 林涛; 陈善本; 王伟

    2004-01-01

    Obtaining the image of molten pool aluminum alloy's tungsten inert gas(TIG)welding becomes a challenging problem in the welding field. In this paper, a bran-new optical sensor based analyzing the light spectrum was designed, and the clear image of the molten pool during the aluminum alloy's welding using the common industrial CCD camera was obtained. And with the new algorithm provided by myself, the desirable characteristic parameters of the molten pool of aluminum alloy's welding were obtained, and it provides a good base for advanced monitor welding quality.

  20. Measurement of the left ventricular regurgitation by gated cardiac blood pool scan: Before and after valvular replacement surgery

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sung Hae; Chung, June Key; Lee, Myung Chul; Cho, Bo Youn; Seo, Jung Don; Lee, Young Woo; Koh, Chang Soon; Suh, Kyung Phill; Lee, Yung Kyoon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1982-09-15

    Quantification of the regurgitation amount is important before and after valvular replacement surgery. Until now cardiac catheterization with cine ventriculography, echocardiography have been used to measure the regurgitation amount, but also have many limitations EKG gated cardiac blood pool scan provides a simple, non-invasive method for quantify the regurgitation amount. By calculating the ratio of left ventricular to right ventricular stroke counts (stroke volume ratio) in gated blood pool scan, we measured the left ventricular regurgitation amount in 28 cases of valvular regurgitation and 25 cases of normal group. 1) Stroke volume ratio was higher in cases of valvular regurgitation(2.11+-0.58) than in cases of normal control(l.15+-0.31). (p<0.01). 2) Stroke volume ratio was classified by regurgitation grade using X-ray cine ventriculography. In grades of mild regurgitation(Grade I-II), stroke volume ratio was 2.02+-0.29, and in grades of severe regurgitation(Grade III-IV), stroke volume ratio was 2.55+-0.34, so stroke volume ratio was well correlated with the grade of X-ray cine ventriculography. 3) Stroke volume ratio was classified by functional class made in New York Heart Association. In classes of mild regurgitation (class I-II), stroke volume ratio was 2.08+-0.26, and in classes of severe regurgitation (class III-IV), stroke volume ratio was 2.55+-0.38, Stroke volume ratio well represented the functional class. 4) After aortic and mitral valve replacement in 28 patients, the stroke volume ratio decreased from 2.11+-0.58 to 1.06+-0.26. Gated blood pool scan provides a noninvasive method of quantifying valvular regurgitation and assessing the result of surgical interventions.

  1. Half a decade of mini-pool nucleic acid testing: Cost-effective way for improving blood safety in India

    Directory of Open Access Journals (Sweden)

    Shivaram Chandrashekar

    2014-01-01

    Full Text Available Background and Objectives: It is well established that Nucleic acid testing (NAT reduces window phase of transfusion transmissible infections (TTI and helps improve blood safety. NAT testing can be done individually or in pools. The objectives of this study were to determine the utility, feasibility and cost effectiveness of an in-house minipool-NAT(MP-NAT. Materials and Methods: Blood donors were screened by history, tested by ELISA and sero-negative samples were subjected to an in-house NAT by using reverse transcriptase-polymerase chain reaction (RT-PCR. Testing was done in mini-pools of size eight (8. Positive pools were repeated with individual samples. Results: During the study period of Oct 2005-Sept 2010 (5 years all blood donors (n=53729 were screened by ELISA. Of which 469 (0.87% were positive for HIV-1, HBV or HCV. Sero-negative samples (n=53260 were screened by in-house MP-NAT. HIV-NAT yield was 1/53260 (n=1 and HBV NAT yield (n=2 was 1/26630. Conclusion: NAT yield was lower than other India studies possibly due to the lower sero-reactivity amongst our donors. Nevertheless it intercepted 9 lives including the components prepared. The in-house assay met our objective of improving blood safety at nominal cost and showed that it is feasible to set up small molecular biology units in medium-large sized blood banks and deliver blood within 24-48 hours. The utility of NAT (NAT yield will vary based on the donor population, the type of serological test used, the nature of kit employed and the sensitivity of NAT test used. The limitations of our in-house MP-NAT consisted of stringent sample preparation requirements, with labor and time involved. The benefits of our MP-NAT were that it acted as a second level of check for ELISA tests, was relatively inexpensive compared to ID-NAT and did not need sophisticated equipment.

  2. [Single-donor (apheresis) platelets and pooled whole-blood-derived platelets--significance and assessment of both blood products].

    Science.gov (United States)

    Hitzler, Walter E

    2014-01-01

    The transfusion efficacy of ATK, which contain fully functional platelets, is beyond all doubt. The equivalence of ATK and PTK has been subject of many studies. Some of those studies show the superiority of ATK's, while others do not, but there have been no studies that demonstrated a superiority of PTK's. The superiority of platelets stored in plasma and in third generation additive solution was demonstrated in clinical studies; therefore, it cannot be said that all the platelet concentrates on the German market are equivalent in efficacy. Of decisive importance, above all, is the risk of transfusion-transmitted infections with known pathogens, or those not yet discovered. This risk is different for ATK compared to PTK. Taking this difference in risk and the difference in donor exposure of transfused patients into account, it can definitely be said that ATK and PTK are not equivalent. In 2012, the Robert-Koch-Institute (RKI) published a mathematical risk model for different platelet concentrates and assessed the risk of transmitting known pathogens such as HIV, HCV, and HBV. The risk was higher for PTK compared to ATK. The relative risks for PTK derived from 4BCs were 2.2 (95%--CI: 2.1-2.4) for HIV, 2.7 (95%--CI: 2.5-3.0) for HCV, and 2.2 (95%--CI: 2.8-3.7) for HBV. At the present time, these are the relative risks of transfusion-transmitted infections with the traditional pathogens for PTK compared to ATK. In addition to the RKI assessed risks, there is the theoretical risk of a new, unknown agent, transmitted through blood exposure. The magnitude of this risk is hardly predictable for PTK. The experience gathered so far, especially in the last three decades, with the emergence of HIV, prions, and West Nil virus, shows that the biological nature of a next transfusion-transmissible infectious agent cannot be predictable. This agent, if we think at a conventional sexually transmissible agent with nucleic acid and long latent period, would spread first in areas with

  3. Telomere length in white blood cell DNA and lung cancer: a pooled analysis of three prospective cohorts.

    Science.gov (United States)

    Seow, Wei Jie; Cawthon, Richard M; Purdue, Mark P; Hu, Wei; Gao, Yu-Tang; Huang, Wen-Yi; Weinstein, Stephanie J; Ji, Bu-Tian; Virtamo, Jarmo; Hosgood, H Dean; Bassig, Bryan A; Shu, Xiao-Ou; Cai, Qiuyin; Xiang, Yong-Bing; Min, Shen; Chow, Wong-Ho; Berndt, Sonja I; Kim, Christopher; Lim, Unhee; Albanes, Demetrius; Caporaso, Neil E; Chanock, Stephen; Zheng, Wei; Rothman, Nathaniel; Lan, Qing

    2014-08-01

    We investigated the relationship between telomere length and lung cancer in a pooled analysis from three prospective cohort studies: the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, conducted among men and women in the United States, and previously published data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Trial conducted among male smokers in Finland, and the Shanghai Women's Health Study (SWHS), which is comprised primarily of never-smokers. The pooled population included 847 cases and 847 controls matched by study, age, and sex. Leukocyte telomere length was measured by a monochrome multiplex qPCR assay. We used conditional logistic regression models to calculate ORs and their 95% confidence intervals (CI) for the association between telomere length and lung cancer risk, adjusted for age and pack-years of smoking. Longer telomere length was associated with increased lung cancer risk in the pooled analysis [OR (95% CI) by quartile: 1.00; 1.24 (0.90-1.71); 1.27 (0.91-1.78); and 1.86 (1.33-2.62); P trend = 0.000022]. Findings were consistent across the three cohorts and strongest for subjects with very long telomere length, i.e., lung cancer risks for telomere length [OR (95% CI)] in the upper half of the fourth quartile were 2.41 (1.28-4.52), 2.16 (1.11-4.23), and 3.02(1.39-6.58) for the PLCO trial, the ATBC trial, and the SWHS, respectively. In addition, the association persisted among cases diagnosed more than 6 years after blood collection and was particularly evident for female adenocarcinoma cases. Telomere length in white blood cell DNA may be a biomarker of future increased risk of lung cancer in diverse populations.

  4. Namibia's transition from whole blood-derived pooled platelets to single-donor apheresis platelet collections

    NARCIS (Netherlands)

    Pitman, John P.; Basavaraju, Sridhar V.; Shiraishi, Ray W.; Wilkinson, Robert; von Finckenstein, Bjorn; Lowrance, David W.; Marfin, Anthony A.; Postma, Maarten; Mataranyika, Mary; Smit Sibinga, Cees Th.

    2015-01-01

    BACKGROUNDFew African countries separate blood donations into components; however, demand for platelets (PLTs) is increasing as regional capacity to treat causes of thrombocytopenia, including chemotherapy, increases. Namibia introduced single-donor apheresis PLT collections in 2007 to increase PLT

  5. Red blood cells, sickle cell (image)

    Science.gov (United States)

    Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). ... abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.

  6. MR angiography of collateral arteries in a hind limb ischemia model: comparison between blood pool agent Gadomer and small contrast agent Gd-DTPA.

    Directory of Open Access Journals (Sweden)

    Karolien Jaspers

    Full Text Available The objective of this study was to compare the blood pool agent Gadomer with a small contrast agent for the visualization of ultra-small, collateral arteries (diameter0.10. Inter-observer variation was 24% and 18% for Gadomer and Gd-DTPA, respectively. In conclusion, blood pool agent Gadomer improved vessel conspicuity compared to Gd-DTPA. Steady-state MRA can be considered as an excellent non-invasive alternative to intra-arterial XRA for the visualization of ultra-small collateral arteries.

  7. Jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe

    DEFF Research Database (Denmark)

    Brøndum, E.; Hasenkam, John Michael; Secher, Niels H.;

    2009-01-01

    in the upright position so that we could lower the head. In the upright position, mean arterial pressure (MAP) was 193 +/- 11 mmHg (mean +/- SE), carotid flow was 0.7 +/- 0.2 l/min, and carotid cross-sectional area was 0.85 +/- 0.04 cm(2). Central venous pressure (CVP) was 4 +/- 2 mmHg, jugular flow was 0...... veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head.......7 +/- 0.2 l/min, and jugular cross-sectional area was 0.14 +/- 0.04 cm(2) (n = 4). Carotid arterial and jugular venous pressures at head level were 118 +/- 9 and -7 +/- 4 mmHg, respectively. When the head was lowered, MAP decreased to 131 +/- 13 mmHg, while carotid cross-sectional area and flow remained...

  8. Red blood cells, multiple sickle cells (image)

    Science.gov (United States)

    Sickle cell anemia is an inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.

  9. Comprehensive model for simultaneous MRI determination of perfusion and permeability using a blood-pool agent in rats rhabdomyosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Bazelaire, Cedric de [Saint Louis Hospital, Radiology Department, Paris (France); Siauve, Nathalie; Fournier, Laure; Clement, Olivier; Kerviler, Eric de; Cuenod, Charles Andre [George Pompidou European Hospital, Radiology Department, Paris (France); Frouin, Frederique [INSERM U494, Faculte de Medecine Pitie-Salpetriere, Paris (France); Robert, Philippe [Guerbet Laboratoire Guerbet, Recherche et Developpement, Paris (France)

    2005-12-01

    To present a new compartmental analysis model developed to simultaneously measure tissue perfusion and capillary permeability in a tumor using MRI and a macromolecular contrast medium. Rhadomyosarcomas were implanted subcutaneously in 20 rats and studied by 1.5-T MRI using a fast gradient echo sequence (2D fast SPGR TR/TE/{alpha} 13 ms/1.2 ms/60 ) after injection of a macromolecular contrast medium. The left ventricle and tumor signal intensities were converted into concentrations and modeled using compartmental analysis, yielding tumor perfusion F, distribution volume V{sub distribution}, volume transfer constant K{sup trans}, rate constant of influx k{sub pe}, and initial extraction (fraction) E. Tumor perfusion was F=43{+-}29 ml.min{sup -1}.100 g{sup -1}. The permeability study allowed the measurement of k{sub pe}=0.37{+-}0.12 min{sup -1} and K{sup trans}=0.01{+-}0.0031 min{sup -1}. The blood volume could be assimilated to the distribution volume (V{sub distribution}=2.9{+-}1.01%) since the capillary leakage was small. The simultaneous assessment of perfusion and permeability allowed quantification of the initial extraction (fraction) E=2.34{+-}1.05%. Quantification of both tumor perfusion and capillary leakage is feasible using MRI using a macromolecular blood pool agent. The method should improve tumor characterization. (orig.)

  10. [Risk Assessment of Single-Donor (Apheresis) Platelet Concentrates and Pooled Whole-Blood-Derived Platelet Concentrates].

    Science.gov (United States)

    Hitzler, Walter; Hutschenreuter, Gabriele; Wartensleben, Herbert

    2015-01-01

    According to the risk estimates of the Robert-Koch-Institute (RKI) and the Paul Ehrlich-Institute (PEI) an equivalence cannot be assumed to exist between the two different platelet preparations. Differences between single-donor (apheresis) platelet concentrates (ATK) and pooled whole-blood-derived platelet concentrates (PTK) result from donor populations, donation intervals, and preparation techniques. There are no prospective randomized studies with regard to the clinical efficacy, which would unambiguously demonstrate equivalence of the therapeutic efficacy of PTK (buffy coat method) in comparison to ATK. The German Association of Blood Transfusion Services (StKB) points out that, due to the non-equivalence of PTK and ATK, it is incumbent on the transfusion physician to select the platelet concentrate, make the appropriate disclosures, and assume treatment responsibility. Proper compensation for ATK and PTK must be ensured by the health insurance companies, whereby a special indication for the selection of either PTK or ATK is not given. Exceptions are patients with known HLA antibodies in which only selected platelet concentrates may be administered. Otherwise, no indication exists in the selection of the different platelet concentrates (Article is in German).

  11. Automated blood vessel extraction using local features on retinal images

    Science.gov (United States)

    Hatanaka, Yuji; Samo, Kazuki; Tajima, Mikiya; Ogohara, Kazunori; Muramatsu, Chisako; Okumura, Susumu; Fujita, Hiroshi

    2016-03-01

    An automated blood vessel extraction using high-order local autocorrelation (HLAC) on retinal images is presented. Although many blood vessel extraction methods based on contrast have been proposed, a technique based on the relation of neighbor pixels has not been published. HLAC features are shift-invariant; therefore, we applied HLAC features to retinal images. However, HLAC features are weak to turned image, thus a method was improved by the addition of HLAC features to a polar transformed image. The blood vessels were classified using an artificial neural network (ANN) with HLAC features using 105 mask patterns as input. To improve performance, the second ANN (ANN2) was constructed by using the green component of the color retinal image and the four output values of ANN, Gabor filter, double-ring filter and black-top-hat transformation. The retinal images used in this study were obtained from the "Digital Retinal Images for Vessel Extraction" (DRIVE) database. The ANN using HLAC output apparent white values in the blood vessel regions and could also extract blood vessels with low contrast. The outputs were evaluated using the area under the curve (AUC) based on receiver operating characteristics (ROC) analysis. The AUC of ANN2 was 0.960 as a result of our study. The result can be used for the quantitative analysis of the blood vessels.

  12. Effect of telmisartan vs. ramipril on 'dipping' status and blood pressure variability: pooled analysis of the PRISMA studies.

    Science.gov (United States)

    Gosse, Philippe; Schumacher, Helmut

    2014-02-01

    A retrospective pooled analysis of the 'Prospective, Randomized Investigation of the Safety and Efficacy of MICARDIS vs. Ramipril Using ABPM' studies conducted in Europe and South Africa (PRISMA I) and in the United States of America and Canada (PRISMA II) was carried out to investigate the effects of telmisartan and ramipril on dipper status (extreme dippers, dippers, non-dippers, risers/reverse dippers), and blood pressure (BP) variability in 1279 patients (with normal sleeping patterns and valid 24-h ambulatory BP monitoring recordings at baseline and end point). After 14 weeks' treatment, telmisartan had a greater systolic BP (SBP) reduction and higher smoothness index in all four dipper groups compared with ramipril. In addition, the tendency toward dipping was significantly higher in patients treated with) telmisartan than ramipril (P=0.032; odds ratio for telmisartan vs. ramipril: 1.27 (95% confidence interval: 1.102-1.58)). In patients with an early morning SBP surge 35 mm Hg, telmisartan treatment was associated with significantly greater reductions from baseline in the night-time low mean, early morning mean and early morning SBP surge compared with ramipril (P=0.026, P<0.0001 and P=0.0006, respectively). In this retrospective analysis, telmisartan was shown to normalize the circadian BP pattern to a dipper profile in a larger proportion of patients than ramipril, and reduce early-morning SBP surge in high-risk patients, indicative of a cardioprotective effect. These findings need to be confirmed in long-term prospective trials and observational studies.

  13. Photoacoustic imaging of blood vessels in tissues

    Science.gov (United States)

    de Mul, Frits F. M.; Pilatou, Magdalena C.; Kolkman, Roy G. M.; Hondebrink, Erwin; Steenbergen, Wiendelt

    2002-10-01

    To localize and monitor the blood content in tissue we developed very sensitive photoacoustical detectors. In these detectors a PVdF-layer has been used as piezo-electric material and also fibers for the illumination of the sample are integrated. The resolution is about 20 im in depth and about 50-100 im laterally. The wavelengths ofthe laser light were 532and 1064 nm. With these colors we can measure at different depths in tissue. We will report measurements on real tissue: vessels in chicken breast, in the human arm, and in test animals at various positions.

  14. The challenges of analysing blood stains with hyperspectral imaging

    Science.gov (United States)

    Kuula, J.; Puupponen, H.-H.; Rinta, H.; Pölönen, I.

    2014-06-01

    Hyperspectral imaging is a potential noninvasive technology for detecting, separating and identifying various substances. In the forensic and military medicine and other CBRNE related use it could be a potential method for analyzing blood and for scanning other human based fluids. For example, it would be valuable to easily detect whether some traces of blood are from one or more persons or if there are some irrelevant substances or anomalies in the blood. This article represents an experiment of separating four persons' blood stains on a white cotton fabric with a SWIR hyperspectral camera and FT-NIR spectrometer. Each tested sample includes standardized 75 _l of 100 % blood. The results suggest that on the basis of the amount of erythrocytes in the blood, different people's blood might be separable by hyperspectral analysis. And, referring to the indication given by erythrocytes, there might be a possibility to find some other traces in the blood as well. However, these assumptions need to be verified with wider tests, as the number of samples in the study was small. According to the study there also seems to be several biological, chemical and physical factors which affect alone and together on the hyperspectral analyzing results of blood on fabric textures, and these factors need to be considered before making any further conclusions on the analysis of blood on various materials.

  15. Ultrafast Ultrasound Imaging of Ocular Anatomy and Blood Flow

    Science.gov (United States)

    Urs, Raksha; Ketterling, Jeffrey A.; Silverman, Ronald H.

    2016-01-01

    Purpose Ophthalmic ultrasound imaging is currently performed with mechanically scanned single-element probes. These probes have limited capabilities overall and lack the ability to image blood flow. Linear-array systems are able to detect blood flow, but these systems exceed ophthalmic acoustic intensity safety guidelines. Our aim was to implement and evaluate a new linear-array–based technology, compound coherent plane-wave ultrasound, which offers ultrafast imaging and depiction of blood flow at safe acoustic intensity levels. Methods We compared acoustic intensity generated by a 128-element, 18-MHz linear array operated in conventionally focused and plane-wave modes and characterized signal-to-noise ratio (SNR) and lateral resolution. We developed plane-wave B-mode, real-time color-flow, and high-resolution depiction of slow flow in postprocessed data collected continuously at a rate of 20,000 frames/s. We acquired in vivo images of the posterior pole of the eye by compounding plane-wave images acquired over ±10° and produced images depicting orbital and choroidal blood flow. Results With the array operated conventionally, Doppler modes exceeded Food and Drug Administration safety guidelines, but plane-wave modalities were well within guidelines. Plane-wave data allowed generation of high-quality compound B-mode images, with SNR increasing with the number of compounded frames. Real-time color-flow Doppler readily visualized orbital blood flow. Postprocessing of continuously acquired data blocks of 1.6-second duration allowed high-resolution depiction of orbital and choroidal flow over the cardiac cycle. Conclusions Newly developed high-frequency linear arrays in combination with plane-wave techniques present opportunities for the evaluation of ocular anatomy and blood flow, as well as visualization and analysis of other transient phenomena such as vessel wall motion over the cardiac cycle and saccade-induced vitreous motion. PMID:27428169

  16. Functional Doppler optical coherence tomography for cortical blood flow imaging

    Science.gov (United States)

    Yu, Lingfeng; Liu, Gangjun; Nguyen, Elaine; Choi, Bernard; Chen, Zhongping

    2010-02-01

    Optical methods have been widely used in basic neuroscience research to study the cerebral blood flow dynamics in order to overcome the low spatial resolution associated with magnetic resonance imaging and positron emission tomography. Although laser Doppler imaging and laser speckle imaging can map out en face cortical hemodynamics and columns, depth resolution is not available. Two-photon microscopy has been used for mapping cortical activity. However, flow measurement requires fluorescent dye injection, which can be problematic. The noninvasive and high resolution tomographic capabilities of optical coherence tomography make it a promising technique for mapping depth resolved cortical blood flow. Here, we present a functional Doppler optical coherence tomography (OCT) imaging modality for quantitative evaluation of cortical blood flow in a mouse model. Fast, repeated, Doppler OCT scans across a vessel of interest were performed to record flow dynamic information with a high temporal resolution of the cardiac cycles. Spectral Doppler analysis of continuous Doppler images demonstrates how the velocity components and longitudinally projected flow-volume-rate change over time, thereby providing complementary temporal flow information to the spatially distributed flow information of Doppler OCT. The proposed functional Doppler OCT imaging modality can be used to diagnose vessel stenosis/blockage or monitor blood flow changes due to pharmacological agents/neuronal activities. Non-invasive in-vivo mice experiments were performed to verify the capabilities of function Doppler OCT.

  17. Quantitative imaging of coronary blood flow

    Directory of Open Access Journals (Sweden)

    Adam M. Alessio

    2010-04-01

    Full Text Available Adam M. Alessio received his PhD in Electrical Engineering from the University of Notre Dame in 2003. During his graduate studies he developed tomographic reconstruction methods for correlated data and helped construct a high-resolution PET system. He is currently a Research Assistant Professor in Radiology at the University of Washington. His research interests focus on improved data processing and reconstruction algorithms for PET/CT systems with an emphasis on quantitative imaging. Erik Butterworth recieved the BA degree in Mathematics from the University of Chicago in 1977. Between 1977 and 1987 he worked as a computer programmer/analyst for several small commercial software firms. Since 1988, he has worked as a software engineer on various research projects at the University of Washington. Between 1988 and 1993 he developed a real-time data aquisition for the analysis of estuarine sediment transport in the department of Geophysics. Between 1988 and 2002 he developed I4, a system for the display and analysis of cardic PET images in the department of Cardiology. Since 1993 he has worked on physiological simulation systems (XSIM from 1993 to 1999, JSim since 1999 at the National Simulation Resource Facility in Cirulatory Mass Transport and Exchange, in the Department of Bioengineering. His research interests include simulation systems and medical imaging. James H. Caldwell, MD, University of Missouri-Columbia 1970, is Professor of Medicine (Cardiology and Radiology and Adjunct Professor of Bioengineering at the University of Washington School of Medicine and Acting Head, Division of Cardiology and Director of Nuclear Cardiology for the University of Washington Hospitals, Seattle WA, USA. James B. Bassingthwaighte, MD, Toronto 1955, PhD Mayo Grad Sch Med 1964, was Professor of Physiology and of Medicine at Mayo Clinic until 1975 when he moved to the University of Washington to chair Bioengineering. He is Professor of Bioengineering and

  18. Holographic laser Doppler imaging of pulsatile blood flow

    CERN Document Server

    Bencteux, Jeffrey; Kostas, Thomas; Bayat, Sam; Atlan, Michael

    2015-01-01

    We report on wide-field imaging of pulsatile motion induced by blood flow using heterodyne holographic interferometry on the thumb of a healthy volunteer, in real-time. Optical Doppler images were measured with green laser light by a frequency-shifted Mach-Zehnder interferometer in off-axis configuration. The recorded optical signal was linked to local instantaneous out-of-plane motion of the skin at velocities of a few hundreds of microns per second, and compared to blood pulse monitored by plethysmoraphy during an occlusion-reperfusion experiment.

  19. Wavelet-analysis for Laser Images of Blood Plasma

    Directory of Open Access Journals (Sweden)

    ANGELSKY, A.-P.

    2011-05-01

    Full Text Available The possibilities of the local wavelet-analysis of polarization-inhomogeneous laser image of human blood plasma were considered. The set of statistics, correlation and fractal parameters of the distributions of wavelet-coefficients that are characterize different scales of the polarization maps of polycrystalline networks of amino acids of blood plasma were defined. The criteria for the differentiation of the transformation of birefringence optical-anisotropic structures of blood plasma at different scales of their geometric dimensions were determined.

  20. Ultrasonic Imaging of Hemodynamic Force in Carotid Blood Flow

    Science.gov (United States)

    Nitta, N.; Homma, K.

    Hemodynamic forces including blood pressure and shear stress affect vulnerable plaque rupture in arteriosclerosis and biochemical activation of endothelium such as NO production. In this study, a method for estimating and imaging shear stress and pressure gradient distributions in blood vessel as the hemodynamic force based on viscosity estimation is presented. Feasibility of this method was investigated by applying to human carotid blood flow. Estimated results of shear stress and pressure gradient distributions coincide with the ideal distributions obtained by numerical simulation and flow-phantom experiment.

  1. Imaging of blood cells based on snapshot Hyper-Spectral Imaging systems

    Science.gov (United States)

    Robison, Christopher J.; Kolanko, Christopher; Bourlai, Thirimachos; Dawson, Jeremy M.

    2015-05-01

    Snapshot Hyper-Spectral imaging systems are capable of capturing several spectral bands simultaneously, offering coregistered images of a target. With appropriate optics, these systems are potentially able to image blood cells in vivo as they flow through a vessel, eliminating the need for a blood draw and sample staining. Our group has evaluated the capability of a commercial Snapshot Hyper-Spectral imaging system, the Arrow system from Rebellion Photonics, in differentiating between white and red blood cells on unstained blood smear slides. We evaluated the imaging capabilities of this hyperspectral camera; attached to a microscope at varying objective powers and illumination intensity. Hyperspectral data consisting of 25, 443x313 hyperspectral bands with ~3nm spacing were captured over the range of 419 to 494nm. Open-source hyper-spectral data cube analysis tools, used primarily in Geographic Information Systems (GIS) applications, indicate that white blood cells features are most prominent in the 428-442nm band for blood samples viewed under 20x and 50x magnification over a varying range of illumination intensities. These images could potentially be used in subsequent automated white blood cell segmentation and counting algorithms for performing in vivo white blood cell counting.

  2. High-resolution imaging of selenium in kidneys: a localized selenium pool associated with glutathione peroxidase 3

    Energy Technology Data Exchange (ETDEWEB)

    Malinouski, M.; Kehr, S.; Finney, L.; Vogt, S.; Carlson, B.A.; Seravalli, J.; Jin, R.; Handy, D.E.; Park, T.J.; Loscalzo, J.; Hatfield, D.L.; Gladyshev, V.N. (Harvard-Med)

    2012-04-17

    Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA{sup [Ser]Sec} and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution.

  3. High-speed imaging of blood splatter patterns

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, T.E.; Albright, K.A.; King, N.S.P.; Yates, G.J. [Los Alamos National Lab., NM (United States); Levine, G.F. [California Dept. of Justice, Sacramento, CA (United States). Bureau of Forensic Services

    1993-05-01

    The interpretation of blood splatter patterns is an important element in reconstructing the events and circumstances of an accident or crime scene. Unfortunately, the interpretation of patterns and stains formed by blood droplets is not necessarily intuitive and study and analysis are required to arrive at a correct conclusion. A very useful tool in the study of blood splatter patterns is high-speed photography. Scientists at the Los Alamos National Laboratory, Department of Energy (DOE), and Bureau of Forensic Services, State of California, have assembled a high-speed imaging system designed to image blood splatter patterns. The camera employs technology developed by Los Alamos for the underground nuclear testing program and has also been used in a military mine detection program. The camera uses a solid-state CCD sensor operating at approximately 650 frames per second (75 MPixels per second) with a microchannel plate image intensifier that can provide shuttering as short as 5 ns. The images are captured with a laboratory high-speed digitizer and transferred to an IBM compatible PC for display and hard copy output for analysis. The imaging system is described in this paper.

  4. Real time blood testing using quantitative phase imaging.

    Directory of Open Access Journals (Sweden)

    Hoa V Pham

    Full Text Available We demonstrate a real-time blood testing system that can provide remote diagnosis with minimal human intervention in economically challenged areas. Our instrument combines novel advances in label-free optical imaging with parallel computing. Specifically, we use quantitative phase imaging for extracting red blood cell morphology with nanoscale sensitivity and NVIDIA's CUDA programming language to perform real time cellular-level analysis. While the blood smear is translated through focus, our system is able to segment and analyze all the cells in the one megapixel field of view, at a rate of 40 frames/s. The variety of diagnostic parameters measured from each cell (e.g., surface area, sphericity, and minimum cylindrical diameter are currently not available with current state of the art clinical instruments. In addition, we show that our instrument correctly recovers the red blood cell volume distribution, as evidenced by the excellent agreement with the cell counter results obtained on normal patients and those with microcytic and macrocytic anemia. The final data outputted by our instrument represent arrays of numbers associated with these morphological parameters and not images. Thus, the memory necessary to store these data is of the order of kilobytes, which allows for their remote transmission via, for example, the cellular network. We envision that such a system will dramatically increase access for blood testing and furthermore, may pave the way to digital hematology.

  5. Proposta do uso de pool de sangue total como controle interno de qualidade em hematologia Proposal for the use of a pool of whole blood as internal quality control in hematology

    Directory of Open Access Journals (Sweden)

    Carina Daniele Schons

    2010-06-01

    Full Text Available INTRODUÇÃO: A confiabilidade dos resultados do laboratório é garantida pela realização do controle de qualidade, que tem como funções básicas análise, pesquisa e prevenção da ocorrência de erros laboratoriais por meio de programas que abrangem tanto o controle interno quanto o externo. OBJETIVO: Propor a padronização de utilização de pool de sangue total como controle interno de qualidade no setor de hematologia. MÉTODO: Foram selecionadas amostras de sangue total, colhidas com ácido etilenodiaminotetracético (EDTA, de mesmos grupo sanguíneo e fator Rh, livres de interferentes, como hemólise, lipemia e icterícia. De um total de 30 ml de sangue total, obtiveram-se três alíquotas de 10 ml cada, às quais foram adicionados, respectivamente, 0 ml (sem adição, 1 ml e 5 ml de glicerol (conservante. As amostras foram avaliadas em contador automático ADVIA® 60. Após determinação dos valores de média e DP, todas as amostras foram avaliadas por um período de 45 dias úteis para confecção do gráfico de Levey-Jennings e verificação da estabilidade da amostra. RESULTADO E CONCLUSÃO: Podemos verificar que o pool de sangue total, preparado de acordo com a metodologia proposta, não apresenta estabilidade necessária para sua utilização, como controle interno alternativo no setor de hematologia.INTRODUCTION: The reliability of laboratory results is ensured by the implementation of quality control, which has basic functions, such as analysis, research and prevention of laboratory errors through programs that encompass both internal and external control. OBJECTIVE: To propose a standard method to use pooled whole blood as internal quality control in the Hematology division. METHOD: The selected whole blood samples were collected with EDTA, belonged to the same blood group and Rh factor and did not present interfering factors, such as hemolysis, lipemia and icterus. From a total of 30 ml of whole blood it was obtained 3

  6. Increased cerebral blood flow in preeclampsia with magnetic resonance imaging

    NARCIS (Netherlands)

    Zeeman, GG; Hatab, MR; Twickler, DM

    2004-01-01

    Objective: The purpose of this study was to compare third trimester and nonpregnant cerebral blood flow of women with preeclampsia to normotensive control subjects with the use of magnetic resonance imaging techniques. Study design: Nine normotensive pregnant women and 12 untreated women with preecl

  7. Peripheral blood smear image analysis: A comprehensive review.

    Science.gov (United States)

    Mohammed, Emad A; Mohamed, Mostafa M A; Far, Behrouz H; Naugler, Christopher

    2014-01-01

    Peripheral blood smear image examination is a part of the routine work of every laboratory. The manual examination of these images is tedious, time-consuming and suffers from interobserver variation. This has motivated researchers to develop different algorithms and methods to automate peripheral blood smear image analysis. Image analysis itself consists of a sequence of steps consisting of image segmentation, features extraction and selection and pattern classification. The image segmentation step addresses the problem of extraction of the object or region of interest from the complicated peripheral blood smear image. Support vector machine (SVM) and artificial neural networks (ANNs) are two common approaches to image segmentation. Features extraction and selection aims to derive descriptive characteristics of the extracted object, which are similar within the same object class and different between different objects. This will facilitate the last step of the image analysis process: pattern classification. The goal of pattern classification is to assign a class to the selected features from a group of known classes. There are two types of classifier learning algorithms: supervised and unsupervised. Supervised learning algorithms predict the class of the object under test using training data of known classes. The training data have a predefined label for every class and the learning algorithm can utilize this data to predict the class of a test object. Unsupervised learning algorithms use unlabeled training data and divide them into groups using similarity measurements. Unsupervised learning algorithms predict the group to which a new test object belong to, based on the training data without giving an explicit class to that object. ANN, SVM, decision tree and K-nearest neighbor are possible approaches to classification algorithms. Increased discrimination may be obtained by combining several classifiers together.

  8. Peripheral blood smear image analysis: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Emad A Mohammed

    2014-01-01

    Full Text Available Peripheral blood smear image examination is a part of the routine work of every laboratory. The manual examination of these images is tedious, time-consuming and suffers from interobserver variation. This has motivated researchers to develop different algorithms and methods to automate peripheral blood smear image analysis. Image analysis itself consists of a sequence of steps consisting of image segmentation, features extraction and selection and pattern classification. The image segmentation step addresses the problem of extraction of the object or region of interest from the complicated peripheral blood smear image. Support vector machine (SVM and artificial neural networks (ANNs are two common approaches to image segmentation. Features extraction and selection aims to derive descriptive characteristics of the extracted object, which are similar within the same object class and different between different objects. This will facilitate the last step of the image analysis process: pattern classification. The goal of pattern classification is to assign a class to the selected features from a group of known classes. There are two types of classifier learning algorithms: supervised and unsupervised. Supervised learning algorithms predict the class of the object under test using training data of known classes. The training data have a predefined label for every class and the learning algorithm can utilize this data to predict the class of a test object. Unsupervised learning algorithms use unlabeled training data and divide them into groups using similarity measurements. Unsupervised learning algorithms predict the group to which a new test object belong to, based on the training data without giving an explicit class to that object. ANN, SVM, decision tree and K-nearest neighbor are possible approaches to classification algorithms. Increased discrimination may be obtained by combining several classifiers together.

  9. High-resolution ultrasound imaging and noninvasive optoacoustic monitoring of blood variables in peripheral blood vessels

    Science.gov (United States)

    Petrov, Irene Y.; Petrov, Yuriy; Prough, Donald S.; Esenaliev, Rinat O.

    2011-03-01

    Ultrasound imaging is being widely used in clinics to obtain diagnostic information non-invasively and in real time. A high-resolution ultrasound imaging platform, Vevo (VisualSonics, Inc.) provides in vivo, real-time images with exceptional resolution (up to 30 microns) using high-frequency transducers (up to 80 MHz). Recently, we built optoacoustic systems for probing radial artery and peripheral veins that can be used for noninvasive monitoring of total hemoglobin concentration, oxyhemoglobin saturation, and concentration of important endogenous and exogenous chromophores (such as ICG). In this work we used the high-resolution ultrasound imaging system Vevo 770 for visualization of the radial artery and peripheral veins and acquired corresponding optoacoustic signals from them using the optoacoustic systems. Analysis of the optoacoustic data with a specially developed algorithm allowed for measurement of blood oxygenation in the blood vessels as well as for continuous, real-time monitoring of arterial and venous blood oxygenation. Our results indicate that: 1) the optoacoustic technique (unlike pure optical approaches and other noninvasive techniques) is capable of accurate peripheral venous oxygenation measurement; and 2) peripheral venous oxygenation is dependent on skin temperature and local hemodynamics. Moreover, we performed for the first time (to the best of our knowledge) a comparative study of optoacoustic arterial oximetry and a standard pulse oximeter in humans and demonstrated superior performance of the optoacoustic arterial oximeter, in particular at low blood flow.

  10. Road traffic noise, blood pressure and heart rate : Pooled analyses of harmonized data from 88,336 participants

    NARCIS (Netherlands)

    Zijlema, Wilma; Cai, Yutong; Doiron, Dany; Mbatchou, Stephan; Fortier, Isabel; Gulliver, John; de Hoogh, Kees; Morley, David; Hodgson, Susan; Elliott, Paul; Key, Timothy; Kongsgard, Havard; Hveem, Kristian; Gaye, Amadou; Burton, Paul; Hansell, Anna; Stolk, Ronald; Rosmalen, Judith

    2016-01-01

    Introduction: Exposure to road traffic noise may increase blood pressure and heart rate. It is unclear to what extent exposure to air pollution may influence this relationship. We investigated associations between noise, blood pressure and heart rate, with harmonized data from three European cohorts

  11. Quantitative blood flow velocity imaging using laser speckle flowmetry

    Science.gov (United States)

    Nadort, Annemarie; Kalkman, Koen; van Leeuwen, Ton G.; Faber, Dirk J.

    2016-04-01

    Laser speckle flowmetry suffers from a debated quantification of the inverse relation between decorrelation time (τc) and blood flow velocity (V), i.e. 1/τc = αV. Using a modified microcirculation imager (integrated sidestream dark field - laser speckle contrast imaging [SDF-LSCI]), we experimentally investigate on the influence of the optical properties of scatterers on α in vitro and in vivo. We found a good agreement to theoretical predictions within certain limits for scatterer size and multiple scattering. We present a practical model-based scaling factor to correct for multiple scattering in microcirculatory vessels. Our results show that SDF-LSCI offers a quantitative measure of flow velocity in addition to vessel morphology, enabling the quantification of the clinically relevant blood flow, velocity and tissue perfusion.

  12. Image Problems Deplete the Number of Women in Academic Applicant Pools

    Science.gov (United States)

    Sears, Anna L. W.

    Despite near numeric parity in graduate schools, women and men in science and mathematics may not perceive the same opportunities for career success. Instead, female doctoral students' career ambitions may often be influenced by perceptions of irreconcilable conflicts between personal and academic goals. This article reports the results of a career goals survey of math and science doctoral students at the University of California, Davis. Fewer women than men began their doctoral programs seeking academic research careers. Of those who initially favored academic research, twice as many women as men downgraded these ambitions during graduate school. Women were more likely to feel geographically constrained by family ties and to express concern about balancing work and family, long work hours, and tenure clock inflexibility. These results partially explain why the percentage of women in academic applicant pools is often well below the number of Ph.D. recipients. The current barriers to gender equity thus cannot be completely ameliorated by increasing the number of women in the pipeline or by altered hiring practices, but changes must be undertaken to make academic research careers more flexible, family friendly, and attractive to women.

  13. Influence of a hyperlipidic diet on the composition of the non-membrane lipid pool of red blood cells of male and female rats

    Directory of Open Access Journals (Sweden)

    Xavier Remesar

    2015-07-01

    Full Text Available Background and objectives. Red blood cells (RBC are continuously exposed to oxidative agents, affecting their membrane lipid function. However, the amount of lipid in RBCs is higher than the lipids of the cell membrane, and includes triacylglycerols, which are no membrane components. We assumed that the extra lipids originated from lipoproteins attached to the cell surface, and we intended to analyse whether the size and composition of this lipid pool were affected by sex or diet.Experimental design. Adult male and female Wistar rats were fed control or cafeteria diets. Packed blood cells and plasma lipids were extracted and analysed for fatty acids by methylation and GC-MS, taking care of not extracting membrane lipids.Results. The absence of ω3-PUFA in RBC extracts (but not in plasma suggest that the lipids extracted were essentially those in the postulated lipid surface pool and not those in cell membrane. In cells’ extracts, there was a marked depletion of PUFA (and, in general, of insaturation. Fatty acid patterns were similar for all groups studied, with limited effects of sex and no effects of diet in RBC (but not in plasma fatty acids. Presence of trans fatty acids was small but higher in RBC lipids, and could not be justified by dietary sources.Conclusions. The presence of a small layer of lipid on the RBC surface may limit oxidative damage to the cell outer structures, and help explain its role in the transport of lipophilic compounds. However, there may be other, so far uncovered, additional functions for this lipid pool.

  14. Intraoperative multi-exposure speckle imaging of cerebral blood flow.

    Science.gov (United States)

    Richards, Lisa M; Kazmi, Sm Shams; Olin, Katherine E; Waldron, James S; Fox, Douglas J; Dunn, Andrew K

    2017-01-01

    Multiple studies have demonstrated that laser speckle contrast imaging (LSCI) has high potential to be a valuable cerebral blood flow monitoring technique during neurosurgery. However, the quantitative accuracy and sensitivity of LSCI is limited, and highly dependent on the exposure time. An extension to LSCI called multi-exposure speckle imaging (MESI) overcomes these limitations, and was evaluated intraoperatively in patients undergoing brain tumor resection. This clinical study ( n = 8) recorded multiple exposure times from the same cortical tissue area spanning 0.5-20 ms, and evaluated images individually as single-exposure LSCI and jointly using the MESI model. This study demonstrated that the MESI estimates provided the broadest flow sensitivity for sampling the flow magnitude in the human brain, closely followed by the shorter exposure times. Conservation of flow analysis on vascular bifurcations was used to validate physiological accuracy, with highly conserved flow estimates (blood flow changes after tissue cautery. Results from this study demonstrate that intraoperative MESI can be performed with high quantitative accuracy and sensitivity for cerebral blood flow monitoring.

  15. An approach to automatic blood vessel image registration of microcirculation for blood flow analysis on nude mice.

    Science.gov (United States)

    Lin, Wen-Chen; Wu, Chih-Chieh; Zhang, Geoffrey; Wu, Tung-Hsin; Lin, Yang-Hsien; Huang, Tzung-Chi; Liu, Ren-Shyan; Lin, Kang-Ping

    2011-04-01

    Image registration is often a required and a time-consuming step in blood flow analysis of large microscopic video sequences in vivo. In order to obtain stable images for blood flow analysis, frame-to-frame image matching as a preprocessing step is a solution to the problem of movement during image acquisition. In this paper, microscopic system analysis without fluorescent labelling is performed to provide precise and continuous quantitative data of blood flow rate in individual microvessels of nude mice. The performance properties of several matching metrics are evaluated through simulated image registrations. An automatic image registration programme based on Powell's optimisation search method with low calculation redundancy was implemented. The matching method by variance of ratio is computationally efficient and improves the registration robustness and accuracy in practical application of microcirculation registration. The presented registration method shows acceptable results in close requisition to analyse red blood cell velocities, confirming the scientific potential of the system in blood flow analysis.

  16. Development of inexpensive blood imaging systems: where are we now?

    Science.gov (United States)

    Chu, Kaiqin; Smith, Zachary J; Wachsmann-Hogiu, Sebastian

    2015-01-01

    Clinical applications in the developing world, such as malaria and anemia diagnosis, demand a change in the medical paradigm of expensive care given in central locations by highly trained professionals. There has been a recent explosion in optical technologies entering the consumer market through the widespread adoption of smartphones and LEDs. This technology commoditization has enabled the development of small, portable optical imaging systems at an unprecedentedly low cost. Here, we review the state-of-the-field of the application of these systems for low-cost blood imaging with an emphasis on cellular imaging systems. In addition to some promising results addressing specific clinical issues, an overview of the technology landscape is provided. We also discuss several key issues that need to be addressed before these technologies can be commercialized.

  17. Holographic laser Doppler imaging of microvascular blood flow

    CERN Document Server

    Magnain, C; Boucneau, T; Simonutti, M; Ferezou, I; Rancillac, A; Vitalis, T; Sahel, J A; Paques, M; Atlan, M

    2014-01-01

    We report on local superficial blood flow monitoring in biological tissue from laser Doppler holographic imaging. In time averaging recording conditions, holography acts as a narrowband bandpass filter, which, combined with a frequency shifted reference beam, permits frequency selective imaging in the radiofrequency range. These Doppler images are acquired with an off axis Mach Zehnder interferometer. Microvascular hemodynamic components mapping is performed in the cerebral cortex of the mouse and the eye fundus of the rat with near-infrared laser light without any exogenous marker. These measures are made from a basic inverse method analysis of local first order optical fluctuation spectra at low radiofrequencies, from 0 Hz to 100 kHz. Local quadratic velocity is derived from Doppler broadenings induced by fluid flows, with elementary diffusing wave spectroscopy formalism in backscattering configuration. We demonstrate quadratic mean velocity assessment in the 0.1 to 10 millimeters per second range in vitro ...

  18. Predictive value of T2-weighted imaging and contrast-enhanced MR imaging in assessing myometrial invasion in endometrial cancer: a pooled analysis of prospective studies

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lian-Ming [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Renji Hospital, Shanghai (China); Wayne State University, Department of Radiology, Detroit, MI (United States); Xu, Jian-Rong; Gu, Hai-Yan; Hua, Jia [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Renji Hospital, Shanghai (China); Haacke, E.M.; Hu, Jiani [Wayne State University, Department of Radiology, Detroit, MI (United States)

    2013-02-15

    To obtain diagnostic performance values of T2-weighted imaging (T2WI) and contrast-enhanced magnetic resonance imaging (CE-MRI) in the prediction of myometrial invasion in patients with endometrial cancer. Databases including MEDLINE and EMBASE were searched for relevant original articles published from January1995 to March 2012. Pooled estimation data were obtained by statistical analysis. Eleven articles (548 patients) were included. For assessing any myometrial involvement, the pooled sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for CE-MRI were 0.81 (95% CI, 0.72, 0.88), 0.72 (95% CI, 0.64, 0.79), 0.65 (95% CI, 0.56, 0.73) and 0.85 (95% CI, 0.78, 0.91); for T2WI, they were 0.87 (95% CI, 0.78, 0.94), 0.58 (95% CI, 0.47, 0.69), 0.64 (95% CI, 0.54, 0.73), 0.84 (95% CI, 0.73, 0.92) respectively. The pooled specificity of CE-MRI (0.72) was significantly higher than T2WI (0.58) (P < 0.05). For assessing deep myometrial involvement, there was no statistically significant difference between CE-MRI and T2WI, (P > 0.05). CE-MRI has a good diagnostic performance in the prediction of any myometrial invasion and is superior to T2WI. But its PPV is somewhat suboptimal. For assessing deep myometrial involvement, its NPV appears relative high and negative findings strongly suggest an absence of deep myometrial involvement, which can guide therapeutic decision-making. (orig.)

  19. T Lymphocytes and Inflammatory Mediators in the Interplay between Brain and Blood in Alzheimer's Disease: Potential Pools of New Biomarkers

    Science.gov (United States)

    Mietelska-Porowska, Anna

    2017-01-01

    Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the main cause of dementia. The disease is among the leading medical concerns of the modern world, because only symptomatic therapies are available, and no reliable, easily accessible biomarkers exist for AD detection and monitoring. Therefore extensive research is conducted to elucidate the mechanisms of AD pathogenesis, which seems to be heterogeneous and multifactorial. Recently much attention has been given to the neuroinflammation and activation of glial cells in the AD brain. Reports also highlighted the proinflammatory role of T lymphocytes infiltrating the AD brain. However, in AD molecular and cellular alterations involving T cells and immune mediators occur not only in the brain, but also in the blood and the cerebrospinal fluid (CSF). Here we review alterations concerning T lymphocytes and related immune mediators in the AD brain, CSF, and blood and the mechanisms by which peripheral T cells cross the blood brain barrier and the blood-CSF barrier. This knowledge is relevant for better AD therapies and for identification of novel biomarkers for improved AD diagnostics in the blood and the CSF. The data will be reviewed with the special emphasis on possibilities for development of AD biomarkers.

  20. Laser speckle contrast imaging to measure changes in cerebral blood flow.

    Science.gov (United States)

    Winship, Ian R

    2014-01-01

    Laser speckle contrast imaging (LSCI) is a powerful tool capable of acquiring detailed maps of blood flow in arteries and veins on the cortical surface. Based on the blurring of laser speckle patterns by the motion of blood cells, LSCI can be combined with a variety of optical imaging preparations to acquire high-spatiotemporal resolution images of blood flow, and track changes in blood flow over time, using relatively simple instrumentation. Here, we describe methods for LSCI of cerebral blood flow via a thin skull imaging preparation in mice or rats. This preparation allows precise semiquantitative mapping of changes in blood flow over time using straightforward surgical protocols and equipment.

  1. Laser speckle imaging of blood flow in microcirculation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Haiying; Luo Qingming; Liu Qian; Lu Qiang; Gong Hui; Zeng Shaoqun [Key Laboratory of Biomedical Photonics of Ministry of Education of China, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2004-04-07

    Monitoring the spatio-temporal characteristics of microcirculation is crucial for studying the functional activities of biotissue and the mechanism of disease. However, conventional methods used to measure blood flow suffer from limited spatial resolution or the injection of exogenous substances or the need of scanning to obtain the dynamic of regional blood flow. Laser speckle imaging (LSI) technique makes up these disadvantages by obtaining the regional blood flow distribution with high spatio-temporal resolution without the need to scan. In this paper, LSI was introduced to investigate the dynamic responses of the rat mesenteric microcirculation to an incremental dose of phentolamine. The results showed that when the dose of phentolamine was less than 4 {mu}g ml{sup -1}, local application of phentolamine on the mesentery would increase the blood perfusion as the concentration increased. When the dose increased further, the improvement decreased. At a dose of 200 {mu}g ml{sup -1}, a microcirculation impediment was caused. At the same time, different responses between veinules and arterioles were manifested. These suggested that LSI is promising to be a useful contribution to drug development and testing.

  2. Bright fluorescent chemosensor platforms for imaging endogenous pools of neuronal zinc.

    Science.gov (United States)

    Chang, Christopher J; Nolan, Elizabeth M; Jaworski, Jacek; Burdette, Shawn C; Sheng, Morgan; Lippard, Stephen J

    2004-02-01

    A series of new fluorescent Zinpyr (ZP) chemosensors based on the fluorescein platform have been prepared and evaluated for imaging neuronal Zn(2+). A systematic synthetic survey of electronegative substitution patterns on a homologous ZP scaffold provides a basis for tuning the fluorescence responses of "off-on" photoinduced electron transfer (PET) probes by controlling fluorophore pK(a) values and attendant proton-induced interfering fluorescence of the metal-free (apo) probes at physiological pH. We further establish the value of these improved optical tools for interrogating the metalloneurochemistry of Zn(2+); the novel ZP3 fluorophore images endogenous stores of Zn(2+) in live hippocampal neurons and slices, including the first fluorescence detection of Zn(2+) in isolated dentate gyrus cultures. Our findings reveal that careful control of fluorophore pK(a) can minimize proton-induced fluorescence of the apo probes and that electronegative substitution offers a general strategy for tuning PET chemosensors for cellular studies. In addition to providing improved optical tools for Zn(2+) in the neurosciences, these results afford a rational starting point for creating superior fluorescent probes for biological applications.

  3. RBCs and Parasites Segmentation from Thin Smear Blood Cell Images

    Directory of Open Access Journals (Sweden)

    Vishal V. Panchbhai

    2012-09-01

    Full Text Available Manually examine the blood smear for the detection of malaria parasite consumes lot of time for trend pathologists. As the computational power increases, the role of automatic visual inspection becomes more important. An automated system is therefore needed to complete as much work as possible for the identification of malaria parasites. The given scheme based on used of RGB color space, G layer processing, and segmentation of Red Blood Cells (RBC as well as cell parasites by auto-thresholding with offset value and use of morphological processing. The work compare with the manual results obtained from the pathology lab, based on total RBC count and cells parasite count. The designed system successfully detects malaria parasites and RBC cells in thin smear image.

  4. In vivo interactions between cobalt or ferric compounds and the pools of sulphide in the blood during and after H2S poisoning.

    Science.gov (United States)

    Haouzi, Philippe; Sonobe, Takashi; Torsell-Tubbs, Nicole; Prokopczyk, Bogdan; Chenuel, Bruno; Klingerman, Candice M

    2014-10-01

    Hydrogen sulphide (H2S), a chemical hazard in oil and gas production, has recently become a dreadful method of suicide, posing specific risks and challenges for the first responders. Currently, there is no proven effective treatment against H2S poisoning and its severe neurological, respiratory or cardiac after-effects. We have recently described that H2S is present in various compartments, or pools, in the body during sulphide exposure, which have different levels of toxicity. The general goals of our study were to (1) determine the concentrations and kinetics of the various pools of hydrogen sulphide in the blood, i.e., gaseous (CgH2S) versus total sulphide, i.e., reacting with monobromobimane (CMBBH2S), during and following H2S exposure in a small and large mammal and (2) establish the interaction between the pools of H2S and a methemoglobin (MetHb) solution or a high dose of hydroxocobalamin (HyCo). We found that CgH2S during and following H2S infusion was similar in sedated sheep and rats at any given rate of infusion/kg and provoked symptoms, i.e., hyperpnea and apnea, at the same CgH2S. After H2S administration was stopped, CgH2S disappeared within 1 min. CMBBH2S also dropped to 2-3μM, but remained above baseline levels for at least 30 min. Infusion of a MetHb solution during H2S infusion produced an immediate reduction in the free/soluble pool of H2S only, whereas CMBBH2S increased by severalfold. HyCo (70 mg/kg) also decreased the concentrations of free/soluble H2S to almost zero; CgH2S returned to pre-HyCo levels within a maximum of 20 min, if H2S infusion is maintained. These results are discussed in the context of a relevant scenario, wherein antidotes can only be administered after H2S exposure.

  5. Nonlinear chemical imaging microscopy: near-field third harmonic generation imaging of human red blood cells.

    Science.gov (United States)

    Schaller, R D; Johnson, J C; Saykally, R J

    2000-11-01

    Third harmonic generation (THG) imaging using a near-field scanning optical microscope (NSOM) is demonstrated for the first time. A femtosecond, tunable near-infrared laser was used to generate both nonresonant and resonantly enhanced third harmonic radiation in human red blood cells. We show that resonantly enhanced THG is a chemically specific bulk probe in NSOM imaging by tuning the excitation source onto and off of resonance with the Soret transition of oxyhemoglobin. Additionally, we provide evidence that tightly focused, nonresonant, far-field THG imaging experiments do not produce contrast that is truly surface specific.

  6. Laser Doppler perfusion monitoring and imaging of blood microcirculation

    Science.gov (United States)

    Nilsson, Gert E.; Wardell, Karin

    1994-07-01

    Laser Doppler perfusion monitoring is a method of assessing tissue perfusion based on measurements performed using Doppler broadening of monochromatic light scattered in moving blood cells. Ever since laser Doppler perfusion monitors became available about 15 years ago they have been used in numerous applications in both clinical and laboratory settings. The high spatial resolution has in practice manifested itself as one of the main limitations of the method. The reason for this is the difficulty in attaining reproducible values at successive measurement sites because most skin tissue possesses a substantial variation in blood flow even at adjacent measurement sites. In order to overcome this difficulty the laser Doppler perfusion imager was developed. In this camera-like device, the laser beam successively scans the tissue and the Doppler components of the backscattered light are detected by a remote photodiode. After a scanning procedure is complete, a color-coded perfusion map showing the spatial variation of skin blood flow is displayed on a monitor. The operating principle and early applications of this emerging technology are addressed in further detail.

  7. Blood Vessels Extraction in Retinal Image Using New Generation Curvelet Transform and Adaptive Weighted Morphology Operators

    Directory of Open Access Journals (Sweden)

    Saleh Shahbeig

    2013-02-01

    Full Text Available According to many medical and biometric applications of retinal images, the automatic and accurate extraction of the retinal blood vessels is very important. In this paper, an effective method is introduced to extract the blood vessels from the background of colored images of retina. In this algorithm, by applying the equalizer function on the retinal images, the brightness of the images is considerably uniformed. Because of high ability of Curvelet transform in introducing image borders in various scale and directions, borders and, consequently the contrast of retinal images can be enhanced. Therefore, the enhanced retinal image can be prepared for the extraction of blood vessels by improving Curvelet coefficients of the retinal images, adaptively and locally. Since the blood vessels in retinal images are distributed in various directions, we use the adaptive weighted morphology operators to extract the blood vessels from retinal images. Morphology operators based on reconstruction are used to refine the appeared frills with the size of smaller than arterioles in images properly. Finally, by analyzing the connected component in the images and applying adaptive filter on the components locally, all residual frills are refined from the images. The proposed algorithm in this paper has been evaluated by the images in the DRIVE database. The results how that the blood vessels are extracted from background of the retinal images of DRIVE database with the high accuracy of 96.15%, which in turn shows the high ability of the proposed algorithm in extracting the retinal blood vessels.

  8. Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

    Directory of Open Access Journals (Sweden)

    Cally Gill

    2013-09-01

    Full Text Available The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  9. Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

    Science.gov (United States)

    He, Diwei; Nguyen, Hoang C.; Hayes-Gill, Barrie R.; Zhu, Yiqun; Crowe, John A.; Gill, Cally; Clough, Geraldine F.; Morgan, Stephen P.

    2013-01-01

    The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue. PMID:24051525

  10. Laser doppler blood flow imaging using a CMOS imaging sensor with on-chip signal processing.

    Science.gov (United States)

    He, Diwei; Nguyen, Hoang C; Hayes-Gill, Barrie R; Zhu, Yiqun; Crowe, John A; Gill, Cally; Clough, Geraldine F; Morgan, Stephen P

    2013-09-18

    The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  11. Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Marlies, E-mail: marlies.wagner@kgu.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Kyriakou, Yiannis, E-mail: yiannis.kyriakou@siemens.com [Siemens AG, Health Care Sector (Germany); Mesnil de Rochemont, Richard du, E-mail: mesnil@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Singer, Oliver C., E-mail: o.singer@em.uni-frankfurt.de [Hospital of Goethe University, Department of Neurology (Germany); Berkefeld, Joachim, E-mail: berkefeld@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany)

    2013-08-01

    PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.

  12. Automatic segmentation of blood vessels from retinal fundus images through image processing and data mining techniques

    Indian Academy of Sciences (India)

    R Geetharamani; Lakshmi Balasubramanian

    2015-09-01

    Machine Learning techniques have been useful in almost every field of concern. Data Mining, a branch of Machine Learning is one of the most extensively used techniques. The ever-increasing demands in the field of medicine are being addressed by computational approaches in which Big Data analysis, image processing and data mining are on top priority. These techniques have been exploited in the domain of ophthalmology for better retinal fundus image analysis. Blood vessels, one of the most significant retinal anatomical structures are analysed for diagnosis of many diseases like retinopathy, occlusion and many other vision threatening diseases. Vessel segmentation can also be a pre-processing step for segmentation of other retinal structures like optic disc, fovea, microneurysms, etc. In this paper, blood vessel segmentation is attempted through image processing and data mining techniques. The retinal blood vessels were segmented through color space conversion and color channel extraction, image pre-processing, Gabor filtering, image postprocessing, feature construction through application of principal component analysis, k-means clustering and first level classification using Naïve–Bayes classification algorithm and second level classification using C4.5 enhanced with bagging techniques. Association of every pixel against the feature vector necessitates Big Data analysis. The proposed methodology was evaluated on a publicly available database, STARE. The results reported 95.05% accuracy on entire dataset; however the accuracy was 95.20% on normal images and 94.89% on pathological images. A comparison of these results with the existing methodologies is also reported. This methodology can help ophthalmologists in better and faster analysis and hence early treatment to the patients.

  13. Fourier analysis of multi-gated blood-pool data in patients with congenital heart disease, (1). Assessment of disease with left to right shunt, especially ventricular septal defect

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kan; Maeda, Hisato; Yamaguchi, Nobuo; Nakamura, Kazuyoshi; Nakagawa, Tsuyoshi (Mie Univ., Tsu (Japan). School of Medicine)

    1983-07-01

    The ventricular emptying performance in patients with congenital heart disease with left to right (L-to-R) shunt was investigated by temporal Fourier analysis of multi-gated cardiac blood-pool data. Functional images are constructed with parameters of each pixel's phase angle and amplitude at fundamental frequency. Using global time-activity curves of both ventricles, phase angle and amplitude of left and right ventricles (LV and RV) were computed. Values of interventricular phase difference (D (phase)) and amplitude ratio of RV to LV (R (amp)) were calculated in individual cases. In 18 subjects with normal cardiac function, mean ( +- standard deviation) values of D (phase) was 1.7 +- 5.8 degree and that of R (amp) was 0.54 +- 0.20, respectively regardless of heart rate. In 22 patients of ventricular septal defect (VSD) with L-to-R shunt, D (phase) became larger in proportion to the ratio of pulmonary to systemic blood flow (Qp/Qs) (r = 0.899, p < 0.001). Especially, in those with large L-to-R shunt (Qp/ Qs < 2.0), significant RV phase lag over 18 degrees was recognized and types of VSD might be possible to be differentiated by phase images. In 9 patients with patent ductus arteriosus (PDA), no RV phase delay was seen. Mean value of R (amp) was considerably smaller in patients with PDA and significantly larger in 11 patients with atrial septal defect (ASD), as compared with that of subjects with normal cardiac functions. However, cases with VSD took the values within normal range. This method is highly valuable for pathophysiologic investigation and differential diagnosis of congenital heart disease with L-to-R shunt.

  14. Ventricular performance in congential left-to-right shunt: temporal Fourier analysis of gated blood-pool data

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, K.

    1983-09-01

    Using global time-activity curves, the phase and amplitude at fundamental frequency were calculated, and emptying patterns of the right and left ventricles (RV, LV) were evaluated by phase difference and RV/LV amplitude ratio. In 21 subjects with normal cardiac function, D(phase) was minimal (mean 2.2 +- 6.1/sup 0/), regardless of heart rate, and R(amp) was distributed from 0.31 to 0.92 (mean 0.57 +- 0.20). In 19 patients of ventricular septal defect (VSD), R(amp) remained within the normal range, whereas D(phase) became larger in proportion to the ratio of pulmonary-to-systemic blood flow, Qp/Qs (p < 0.001). Especially, cases with Qp/Qs over 2.0 showed a significant RV phase lag. By contrast, nine patients with patent ductus arteriosus (PDA), showed no RV phase lag, but - particularly in cases with Qp/Qs > 2.0 - R(amp) was smaller than normal (p < 0.001). Thus this method is valuable for pathophysiologic investigation of diseases with L-to-R shunt, and can help in the noninvasive differential diagnosis between VSD and PDA.

  15. Vernal Pools

    Data.gov (United States)

    California Department of Resources — This is a polygon layer representing existing vernal pool complexes in California's Central Valley, as identified and mapped by Dr. Robert F. Holland. The purpose of...

  16. Fast Blood Vector Velocity Imaging using ultrasound: In-vivo examples of complex blood flow in the vascular system

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Udesen, Jesper; Gran, Fredrik;

    2008-01-01

    speckle tracking between segments in consecutive speckle images. The flow patterns of six bifurcations and two veins were investigated in-vivo. It was shown: 1) that a stable vortex in the carotid bulb was present opposed to other examined bifurcations, 2) that retrograde flow was present......Conventional ultrasound methods for acquiring color flow images of the blood motion are restricted by a relatively low frame rate and angle dependent velocity estimates. The Plane Wave Excitation (PWE) method has been proposed to solve these limitations. The frame rate can be increased, and the 2-D...... vector velocity of the blood motion can be estimated. The transmitted pulse is not focused, and a full speckle image of the blood can be acquired for each emission. A 13 bit Barker code is transmitted simultaneously from each transducer element. The 2-D vector velocity of the blood is found using 2-D...

  17. Espacio Pool

    OpenAIRE

    2013-01-01

    Espacio Pool es un grupo abierto de usuarios vinculados a la Facultad de Bellas Artes UCM que actúa sobre los márgenes que la circundan. Toma su nombre de los estanques vacíos ubicados en los jardines de la cafetería, y elige el término anglosajón por sus connotaciones relativas a lo participativo y autogestionado. Su objetivo es habitar los espacios de “vacuidad” para que sean efectivos y permutadores. Espacio Pool organiza la celebración de encuentros a partir de la construcción de disposit...

  18. Determining tumor blood flow parameters from dynamic image measurements

    Science.gov (United States)

    Libertini, Jessica M.

    2008-11-01

    Many recent cancer treatments focus on preventing angiogenesis, the process by which a tumor promotes the growth of large and efficient capillary beds for the increased nourishment required to support the tumor's rapid growth[l]. To measure the efficacy of these treatments in a timely fashion, there is an interest in using data from dynamic sequences of contrast-enhanced medical imaging, such as MRI and CT, to measure blood flow parameters such as perfusion, permeability-surface-area product, and the relative volumes of the plasma and extracellular-extravascular space. Starting with a two compartment model presented by the radiology community[2], this work challenges the application of a simplification to this problem, which was originally developed to model capillary reuptake[3]. While the primary result of this work is the demonstration of the inaccuracy of this simplification, the remainder of the paper is dedicated to presenting alternative methods for calculating the perfusion and plasma volume coefficients. These methods are applied to model data sets based on real patient data, and preliminary results are presented.

  19. Determining tumor blood flow parameters from dynamic image measurements

    Energy Technology Data Exchange (ETDEWEB)

    Libertini, Jessica M [Division of Applied Mathematics, Brown University, Providence, Rhode Island 02906 (United States)], E-mail: Jessica_Libertini@brown.edu

    2008-11-01

    Many recent cancer treatments focus on preventing angiogenesis, the process by which a tumor promotes the growth of large and efficient capillary beds for the increased nourishment required to support the tumor's rapid growth. To measure the efficacy of these treatments in a timely fashion, there is an interest in using data from dynamic sequences of contrast-enhanced medical imaging, such as MRI and CT, to measure blood flow parameters such as perfusion, permeability-surface-area product, and the relative volumes of the plasma and extracellular-extravascular space. Starting with a two compartment model presented by the radiology community, this work challenges the application of a simplification to this problem, which was originally developed to model capillary reuptake. While the primary result of this work is the demonstration of the inaccuracy of this simplification, the remainder of the paper is dedicated to presenting alternative methods for calculating the perfusion and plasma volume coefficients. These methods are applied to model data sets based on real patient data, and preliminary results are presented.

  20. Blood vessel classification into arteries and veins in retinal images

    Science.gov (United States)

    Kondermann, Claudia; Kondermann, Daniel; Yan, Michelle

    2007-03-01

    The prevalence of diabetes is expected to increase dramatically in coming years; already today it accounts for a major proportion of the health care budget in many countries. Diabetic Retinopathy (DR), a micro vascular complication very often seen in diabetes patients, is the most common cause of visual loss in working age population of developed countries today. Since the possibility of slowing or even stopping the progress of this disease depends on the early detection of DR, an automatic analysis of fundus images would be of great help to the ophthalmologist due to the small size of the symptoms and the large number of patients. An important symptom for DR are abnormally wide veins leading to an unusually low ratio of the average diameter of arteries to veins (AVR). There are also other diseases like high blood pressure or diseases of the pancreas with one symptom being an abnormal AVR value. To determine it, a classification of vessels as arteries or veins is indispensable. As to our knowledge despite the importance there have only been two approaches to vessel classification yet. Therefore we propose an improved method. We compare two feature extraction methods and two classification methods based on support vector machines and neural networks. Given a hand-segmentation of vessels our approach achieves 95.32% correctly classified vessel pixels. This value decreases by 10% on average, if the result of a segmentation algorithm is used as basis for the classification.

  1. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...... masking of a vessel position and measurements of it's diameter from laser speckle images. This approach demonstrates high reliability and stability....

  2. High-resolution blood-pool-contrast-enhanced MR angiography in glioblastoma: tumor-associated neovascularization as a biomarker for patient survival. A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Josep; Blasco, Gerard; Remollo, Sebastian; Hernandez, David; Pedraza, Salvador [Hospital Universitari Dr Josep Trueta, Research Unit of Diagnostic Imaging Institute (IDI), Department of Radiology [Girona Biomedical Research Institute] IDIBGI, Girona (Spain); Daunis-i-Estadella, Josep; Mateu, Gloria [University of Girona, Department of Computer Science, Applied Mathematics and Statistics, Girona (Spain); Alberich-Bayarri, Angel [La Fe Polytechnics and University Hospital, Biomedical Imaging Research Group (GIBI230), La Fe Health Research Institute, Valencia (Spain); Essig, Marco [University of Manitoba, Department of Radiology, Winnipeg (Canada); Jain, Rajan [NYU School of Medicine, Division of Neuroradiology, Department of Radiology, New York, NY (United States); Puigdemont, Montserrat [Hospital Universitari Dr Josep Trueta, Catalan Institute of Oncology (ICO), Hospital Cancer Registry, Girona (Spain); Sanchez-Gonzalez, Javier [Philips Healthcare Iberica, Madrid (Spain); Wintermark, Max [Stanford University, Department of Radiology, Neuroradiology Division, Palo Alto, CA (United States)

    2016-01-15

    The objective of the study was to determine whether tumor-associated neovascularization on high-resolution gadofosveset-enhanced magnetic resonance angiography (MRA) is a useful biomarker for predicting survival in patients with newly diagnosed glioblastomas. Before treatment, 35 patients (25 men; mean age, 64 ± 14 years) with glioblastoma underwent MRI including first-pass dynamic susceptibility contrast (DSC) perfusion and post-contrast T1WI sequences with gadobutrol (0.1 mmol/kg) and, 48 h later, high-resolution MRA with gadofosveset (0.03 mmol/kg). Volumes of interest for contrast-enhancing lesion (CEL), non-CEL, and contralateral normal-appearing white matter were obtained, and DSC perfusion and DWI parameters were evaluated. Prognostic factors were assessed by Kaplan-Meier survival and Cox proportional hazards model. Eighteen (51.42 %) glioblastomas were hypervascular on high-resolution MRA. Hypervascular glioblastomas were associated with higher CEL volume and lower Karnofsky score. Median survival rates for patients with hypovascular and hypervascular glioblastomas treated with surgery, radiotherapy, and chemotherapy were 15 and 9.75 months, respectively (P < 0.001). Tumor-associated neovascularization was the best predictor of survival at 5.25 months (AUC = 0.794, 81.2 % sensitivity, 77.8 % specificity, 76.5 % positive predictive value, 82.4 % negative predictive value) and yielded the highest hazard ratio (P < 0.001). Tumor-associated neovascularization detected on high-resolution blood-pool-contrast-enhanced MRA of newly diagnosed glioblastoma seems to be a useful biomarker that correlates with worse survival. (orig.)

  3. Malaria diagnosis from pooled blood samples: comparative analysis of real-time PCR, nested PCR and immunoassay as a platform for the molecular and serological diagnosis of malaria on a large-scale

    Directory of Open Access Journals (Sweden)

    Giselle FMC Lima

    2011-09-01

    Full Text Available Malaria diagnoses has traditionally been made using thick blood smears, but more sensitive and faster techniques are required to process large numbers of samples in clinical and epidemiological studies and in blood donor screening. Here, we evaluated molecular and serological tools to build a screening platform for pooled samples aimed at reducing both the time and the cost of these diagnoses. Positive and negative samples were analysed in individual and pooled experiments using real-time polymerase chain reaction (PCR, nested PCR and an immunochromatographic test. For the individual tests, 46/49 samples were positive by real-time PCR, 46/49 were positive by nested PCR and 32/46 were positive by immunochromatographic test. For the assays performed using pooled samples, 13/15 samples were positive by real-time PCR and nested PCR and 11/15 were positive by immunochromatographic test. These molecular methods demonstrated sensitivity and specificity for both the individual and pooled samples. Due to the advantages of the real-time PCR, such as the fast processing and the closed system, this method should be indicated as the first choice for use in large-scale diagnosis and the nested PCR should be used for species differentiation. However, additional field isolates should be tested to confirm the results achieved using cultured parasites and the serological test should only be adopted as a complementary method for malaria diagnosis.

  4. Blood-brain barrier permeability imaging using perfusion computed tomography

    Directory of Open Access Journals (Sweden)

    Avsenik Jernej

    2015-06-01

    Full Text Available Background. The blood-brain barrier represents the selective diffusion barrier at the level of the cerebral microvascular endothelium. Other functions of blood-brain barrier include transport, signaling and osmoregulation. Endothelial cells interact with surrounding astrocytes, pericytes and neurons. These interactions are crucial to the development, structural integrity and function of the cerebral microvascular endothelium. Dysfunctional blood-brain barrier has been associated with pathologies such as acute stroke, tumors, inflammatory and neurodegenerative diseases.

  5. Blood-brain barrier permeability imaging using perfusion computed tomography

    OpenAIRE

    Avsenik Jernej; Bisdas Sotirios; Popovic Katarina Surlan

    2015-01-01

    Background. The blood-brain barrier represents the selective diffusion barrier at the level of the cerebral microvascular endothelium. Other functions of blood-brain barrier include transport, signaling and osmoregulation. Endothelial cells interact with surrounding astrocytes, pericytes and neurons. These interactions are crucial to the development, structural integrity and function of the cerebral microvascular endothelium. Dysfunctional blood-brain barrier has been associated with patholog...

  6. Image resizing using saliency strength map and seam carving for white blood cell analysis

    Directory of Open Access Journals (Sweden)

    Nam JaeYeal

    2010-09-01

    Full Text Available Abstract Background A new image-resizing method using seam carving and a Saliency Strength Map (SSM is proposed to preserve important contents, such as white blood cells included in blood cell images. Methods To apply seam carving to cell images, a SSM is initially generated using a visual attention model and the structural properties of white blood cells are then used to create an energy map for seam carving. As a result, the energy map maximizes the energies of the white blood cells, while minimizing the energies of the red blood cells and background. Thus, the use of a SSM allows the proposed method to reduce the image size efficiently, while preserving the important white blood cells. Results Experimental results using the PSNR (Peak Signal-to-Noise Ratio and ROD (Ratio of Distortion of blood cell images confirm that the proposed method is able to produce better resizing results than conventional methods, as the seam carving is performed based on an SSM and energy map. Conclusions For further improvement, a faster medical image resizing method is currently being investigated to reduce the computation time, while maintaining the same image quality.

  7. Nephron blood flow dynamics measured by laser speckle contrast imaging

    DEFF Research Database (Denmark)

    von Holstein-Rathlou, Niels-Henrik; Sosnovtseva, Olga V; Pavlov, Alexey N

    2011-01-01

    Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubula...

  8. Imaging polarimetry and retinal blood vessel quantification at the epiretinal membrane

    Science.gov (United States)

    Miura, Masahiro; Elsner, Ann E.; Cheney, Michael C.; Usui, Masahiko; Iwasaki, Takuya

    2007-05-01

    We evaluated a polarimetry method to enhance retinal blood vessels masked by the epiretinal membrane. Depolarized light images were computed by removing the polarization retaining light reaching the instrument and were compared with parallel polarized light images, average reflectance images, and the corresponding images at 514 nm. Contrasts were computed for retinal vessel profiles for arteries and veins. Contrasts were higher in the 514 nm images in normal eyes but higher in the depolarized light image in the eyes with epiretinal membranes. Depolarized light images were useful for examining the retinal vasculature in the presence of retinal disease.

  9. Delayed sodium (18)F-fluoride PET/CT imaging does not improve quantification of vascular calcification metabolism

    DEFF Research Database (Denmark)

    Blomberg, Björn Alexander; Thomassen, Anders; Takx, Richard A P;

    2014-01-01

    This study aimed to determine if delayed sodium (18)F-fluoride (Na(18)F) PET/CT imaging improves quantification of vascular calcification metabolism. Blood-pool activity can disturb the arterial Na(18)F signal. With time, blood-pool activity declines. Therefore, delayed imaging can potentially...... improve quantification of vascular calcification metabolism....

  10. Current Imaging Modalities for assessing Ocular Blood Flow in Glaucoma

    OpenAIRE

    Mohindroo, Chirayu; Ichhpujani, Parul; Kumar, Suresh

    2016-01-01

    Glaucoma may be caused by an interplay of elevated intraocular pressure (IOP), vascular, genetic, anatomical, brain, and immune factors. The direct assessment of ocular hemodynam-ics offers promise for glaucoma detection, differentiation, and possibly new treatment modalities. All the methods currently in use to measure ocular blood flow have inherent limitations and measure different aspects of ocular blood flow. This review article attempts to provide detailed information on ocular perfu-si...

  11. Extraction of the magnetohydrodynamic blood flow potential from the surface electrocardiogram in magnetic resonance imaging.

    Science.gov (United States)

    Nijm, Grace M; Swiryn, Steven; Larson, Andrew C; Sahakian, Alan V

    2008-07-01

    The magnetohydrodynamic effect generates voltages related to blood flow, which are superimposed on the electrocardiogram (ECG) used for gating during cardiac magnetic resonance imaging (MRI). A method is presented for extracting the magnetohydrodynamic signal from the ECG. The extracted magnetohydrodynamic blood flow potential may be physiologically meaningful due to its relationship to blood flow. Removal of the magnetohydrodynamic voltages from the ECG can potentially lead to improved gating and diagnostically useful ECGs.

  12. Evaluation of Influence of Acupuncture and Electro-Acupuncture for Blood Perfusion of Stomach by Laser Doppler Blood Perfusion Imaging

    OpenAIRE

    Zhang Dong; Li Shun-Yue; Wang Shu-You; Ma Hui-Min

    2011-01-01

    The objective of this study is to observe effects of acupuncture and electro-acupuncture (EA) on blood perfusion in the stomach, and probe into the application of laser Doppler blood perfusion imaging technique in the study of the effect of acupuncture and moxibustion on the entrails. In the acupuncture group of 20 rats, acupuncture was given at “Zusanli” (ST 36) and in EA group of 18 rats, EA was applied at “Zusanli” (ST 36), with 18 rats without acupuncture used as control group. Changes of...

  13. Segmentation of leukocytes and erythrocytes in blood smear images.

    Science.gov (United States)

    Bergen, Tobias; Steckhan, Dirk; Wittenberg, Thomas; Zerfass, Thorsten

    2008-01-01

    Differential blood count is a standard method in hematological laboratory diagnosis. In the course of developing a computer-assisted microscopy system for the generation of differential blood counts, the detection and segmentation of white and red blood cells forms an essential step and its exactness is a fundamental prerequisite for the effectiveness of the subsequent classification step. We propose a method for the exact segmentation of leukocytes and erythrocytes in a simultaneous and cooperative way. We combine pixel-wise classification with template matching to locate erythrocytes and use a level-set approach in order to get the exact cell contours of leukocyte nucleus and plasma regions as well as erythrocyte regions. An evaluation comparing the performance of the algorithm to the manual segmentation performed by several persons yielded good results.

  14. Photoacoustic monitoring and imaging of blood vessels in tissue

    Science.gov (United States)

    Kolkman, Roy G. M.; Pilatou, Magdalena C.; Steenbergen, Wiendelt; de Mul, Frits F. M.

    2002-06-01

    Using very sensitive photoacoustical detectors we localized and monitored the blood content in tissue. In these detectors a PVdF-layer has been used as piezo-electric material and also fibers for the illumination of the sample are integrated. The resolution is about 20micrometers in depth and about 50-100micrometers laterally. The wavelengths of the laser light were 532 and 1064 nm. With these colors we can measure at different depths in tissue. The measurements concerned blood perfusion in real tissue: vessels in chicken breast, in test animals at various positions and in the human arm.

  15. Blood Flow Imaging in Maternal and Fetal Arteries and Veins

    Science.gov (United States)

    Ricci, S.; Urban, G.; Vergani, P.; Paidas, M. J.; Tortoli, P.

    Maternal and fetal blood circulation has been investigated for nearly a decade through ultrasound (US) techniques. Evaluation of the spectrogram related to a single sample volume has been proven valuable for the assessment of fetal well-being and for prediction of pregnancy complications. In this work, an alternative technique, called Multigate Spectral Doppler Analysis (MSDA), is proposed. In this approach, 128 sample volumes aligned along the same scan line are simultaneously investigated to detect the blood velocity profile with high resolution. Profiles obtained through MSDA reveal features not detectable with the standard US technique, thus representing a more accurate flow signature. Some preliminary illustrative results are reported here.

  16. Absolute cerebral blood flow and blood volume measured by magnetic resonance imaging bolus tracking: comparison with positron emission tomography values

    DEFF Research Database (Denmark)

    Østergaard, Leif; Smith, D F; Vestergaard-Poulsen, Peter;

    1998-01-01

    The authors determined cerebral blood flow (CBF) with magnetic resonance imaging (MRI) of contrast agent bolus passage and compared the results with those obtained by O-15 labeled water (H215O) and positron emission tomography (PET). Six pigs were examined by MRI and PET under normo......- and hypercapnic conditions. After dose normalization and introduction of an empirical constant phi Gd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral...... blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small...

  17. Ontology-based Malaria Parasite Stage and Species Identification from Peripheral Blood Smear Images

    NARCIS (Netherlands)

    Makkapati, V.; Rao, R.

    2011-01-01

    The diagnosis and treatment of malaria infection requires detectingthe presence of malaria parasite in the patient as well as identification of the parasite species. We present an image processing-basedapproach to detect parasites in microscope images of blood smear andan ontology-based classificati

  18. Red blood cell cluster separation from digital images for use in sickle cell disease.

    Science.gov (United States)

    González-Hidalgo, Manuel; Guerrero-Peña, F A; Herold-García, S; Jaume-I-Capó, Antoni; Marrero-Fernández, P D

    2015-07-01

    The study of cell morphology is an important aspect of the diagnosis of some diseases, such as sickle cell disease, because red blood cell deformation is caused by these diseases. Due to the elongated shape of the erythrocyte, ellipse adjustment and concave point detection are applied widely to images of peripheral blood samples, including during the detection of cells that are partially occluded in the clusters generated by the sample preparation process. In the present study, we propose a method for the analysis of the shape of erythrocytes in peripheral blood smear samples of sickle cell disease, which uses ellipse adjustments and a new algorithm for detecting notable points. Furthermore, we apply a set of constraints that allow the elimination of significant image preprocessing steps proposed in previous studies. We used three types of images to validate our method: artificial images, which were automatically generated in a random manner using a computer code; real images from peripheral blood smear sample images that contained normal and elongated erythrocytes; and synthetic images generated from real isolated cells. Using the proposed method, the efficiency of detecting the two types of objects in the three image types exceeded 99.00%, 98.00%, and 99.35%, respectively. These efficiency levels were superior to the results obtained with previously proposed methods using the same database, which is available at http://erythrocytesidb.uib.es/. This method can be extended to clusters of several cells and it requires no user inputs.

  19. Fast Blood Vector Velocity Imaging: Simulations and Preliminary In Vivo Results

    DEFF Research Database (Denmark)

    Udesen, Jesper; Gran, Fredrik; Hansen, Kristoffer Lindskov;

    2007-01-01

    I Background: Conventional ultrasound methods for acquiring color flow images of the blood velocity are limited by a relatively low frame rate and are restricted to only give velocity estimates along the ultrasound beam direction. To circumvent these limitations, we propose a method where the frame...... rate can be significantly increased, and the full 2-D vector velocity of the blood can be estimated. II Method: The method presented in this paper uses three techniques: 1) The ultrasound is not focused during the transmit of the ultrasound signals, and a full speckle image of the blood can be acquired...... for each pulse emission. 2) The transmitted pulse consists of a 13 bit Barker code which is transmitted simultaneously from each transducer element. 3) The 2-D vector velocity of the blood is found using 2-D speckle tracking between segments in consecutive speckle images. III Results: The method was tested...

  20. Blood-Brain Barrier Imaging in Human Neuropathologies

    Science.gov (United States)

    Veksler, Ronel; Shelef, Ilan; Friedman, Alon

    2014-01-01

    The blood–brain barrier (BBB) is essential for normal function of the brain, and its role in many brain pathologies has been the focus of numerous studies during the last decades. Dysfunction of the BBB is not only being shown in numerous brain diseases, but animal studies have indicated that it plays a direct key role in the genesis of neurovascular dysfunction and associated neurodegeneration. As such evidence accumulates, the need for robust and clinically applicable methods for minimally invasive assessment of BBB integrity is becoming urgent. This review provides an introduction to BBB imaging methods in the clinical scenario. First, imaging modalities are reviewed, with a focus on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). We then proceed to review image analysis methods, including quantitative and semi-quantitative methods. The advantages and limitations of each approach are discussed, and future directions and questions are highlighted. PMID:25453223

  1. Measurement of temperature decrease caused by blood flow in focused ultrasound irradiation by thermal imaging method

    Science.gov (United States)

    Tsuchiya, Takenobu; Hatano, Yuichi; Mori, Yashunori; Shen, Rakushin; Endoh, Nobuyuki

    2016-07-01

    In this study, to estimate the local temperature changes caused by a thick blood vessel, the temperature distribution in a tissue phantom with a thick blood vessel during focused ultrasound irradiation was measured by a thermal imaging method. The blood flow rate in the simulated blood vessel was varied and the relationship between flow rate and temperature decrease was examined. The phantom using the thermal imaging method is divided into two parts, and the increases in temperature distribution as a function of blood flow rate are measured using a thermocamera under constant ultrasound irradiation. The irradiation conditions of ultrasound waves were a central frequency of 1 MHz, a wave number length of 200 cycles, and a duty ratio of 0.2. The irradiation duration was 5 min, and the ultrasound intensity I SPTA was 36 W/cm2. The amount of temperature decrease caused by the cooling effect of blood flow increased with the blood flow rate and it became constant at a certain threshold of blood flow rate. The threshold of blood flow rate is about 250 ml/min.

  2. Photoacoustic imaging of blood perfusion in tissue and phantoms

    Science.gov (United States)

    Pilatou, Magdalena C.; Kolkman, Roy G. M.; Hondebrink, Erwin; Bolt, Rene A.; de Mul, Frits F. M.

    2001-06-01

    To localize and monitor the blood content in tissue we developed a very sensitive photo-acoustical detector. PVDF has been used as piezo-electric material. In this detector also fibers for the illumination of the sample are integrated. Resolution is about 20 (m in depth and about 50-100 m laterally). We use 532 nm light. We will show how photoacoustics can be used for measuring the thickness of tissue above bone. We will also report measurements on tissue phantoms: e.g. a vessel delta from the epigastric artery branching of a Wistar rat, filled with an artificial blood-resembling absorber. The measurements have been carried out on phantoms containing vessels at several depths. Signal processing was enhanced by Fourier processing of the data.

  3. Recent advances in blood flow vector velocity imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Nikolov, Svetoslav; Udesen, Jesper;

    2011-01-01

    investigated using both simulations, flow rig measurements, and in-vivo validation against MR scans. The TO method obtains a relative accuracy of 10% for a fully transverse flow in both simulations and flow rig experiments. In-vivo studies performed on 11 healthy volunteers comparing the TO method...... been acquired using a commercial implementation of the method (BK Medical ProFocus Ultraview scanner). A range of other methods are also presented. This includes synthetic aperture imaging using either spherical or plane waves with velocity estimation performed with directional beamforming or speckle...... Medical 8804 transducer. This resulted in a relative standard deviation of 1.2% for a fully transverse flow. Plane wave imaging was also implemented on the RASMUS scanner and a 100 Hz frame rate was attained. Several vector velocity image sequences of complex flow were acquired, which demonstrates...

  4. Clinical features and imaging findings in pulmonary capillary hemangiomatosis: report of two cases and a pooled analysis

    Institute of Scientific and Technical Information of China (English)

    XIE Wan-mu; DAI Hua-ping; JIN Mu-lan; WANG Zhen; YANG Yuan-hua; ZHAI Zhen-guo; WANG Chen

    2012-01-01

    Background Pulmonary capillary hemangiomatosis (PCH) is a rare disease and no Chinese case has been reported yet.The disease is often misdiagnosed and its clinical characteristics are incompletely described.The aim of this study was to describe two Chinese cases and to clarify the clinical and radiographic parameters of patients with PCH.Methods Two PCH cases were presented and other cases were searched from the English literature.All available clinical and radiographic data were collected from 62 literature reported PCH cases.A pooled analysis of total 64 cases was made.Results Dyspnea and hemoptysis were the most common clinical symptoms of PCH.Pulmonary hypertension (PH)was found in 78% of the reported cases.PCH typically showed characteristic diffuse or patchy ground-glass opacities (GGOs) and/or multiple ill-defined centrilobular nodules in the computed tomography.Conclusions The diagnosis of PCH requires a high clinical suspicion.However,both clinical presentations and radiographic studies often provide clues to the diagnosis,which may prompt early lung biopsy for a definite diagnosis.

  5. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogami, M; Kulkarni, R; Wang, H; Reif, R; Wang, R K [University of Washington, Department of Bioengineering, Seattle, Washington 98195 (United States)

    2014-08-31

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing. (laser biophotonics)

  6. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Science.gov (United States)

    Ogami, M.; Kulkarni, R.; Wang, H.; Reif, R.; Wang, R. K.

    2014-08-01

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing.

  7. Vision-based detection of MAG weld pool

    Institute of Scientific and Technical Information of China (English)

    Gao Jinqiang; Wu Chuansong; Zhang Min; Zhao Yanhua

    2007-01-01

    Weld pool contains significant information about the welding process. The weld pool images of MAG welding are detected by LaserStrobe system. An algorithm for extracting weld pool edge is proposed according to the characteristics of MAG weld pool images. The maximum weld pool length and width are calculated. The measurement data can be used to verify the results of welding process simulation and to provide a good foundation for automatic control of MAG welding process.

  8. RT-PCR em pools de soros sangüíneos para o diagnóstico da infecção aguda e de animais persistentemente infectados pelo vírus da diarréia viral bovina RT-PCR in pools of bovine blood serum to detect acute infection and persistently infected animals with bovine viral diarrhea virus

    Directory of Open Access Journals (Sweden)

    D. Pilz

    2007-02-01

    Full Text Available Utilizou-se a técnica da RT-PCR para a detecção da região 5' UTR do genoma do vírus da diarréia viral bovina (BVDV em pools de soros sangüíneos provenientes de um rebanho, constituído por 226 animais, que apresentava distúrbios da reprodução. A partir das amostras individuais de soro e de acordo com a categoria dos animais e o número de animais por categoria foram formados 10 pools (A a J de soros. A primeira avaliação revelou a amplificação de um produto com 290pb nas reações referentes aos grupos D (35 vacas e H (25 bezerros lactentes que, após o desmembramento em amostras individuais, resultou na identificação de 11 vacas lactantes e 12 bezerros em amamentação positivos. Para a identificação de animais persistentemente infectados (PI entre os 23 positivos na primeira avaliação, realizou-se a segunda colheita de soros sangüíneos, três meses após. A RT-PCR das amostras individuais de soro revelou resultado positivo em cinco bezerros. Em dois, foi possível isolar o BVDV em cultivo de células MDBK. A especificidade das reações da RT-PCR foi confirmada pelo seqüenciamento dos produtos amplificados a partir do soro de uma vaca com infecção aguda, de um bezerro PI e das duas amostras do BVDV isoladas em cultivo celular. A utilização da RT-PCR em pools de soros sangüíneos demonstrou ser uma estratégia rápida de diagnóstico etiológico e de baixo custo tanto para a detecção de infecção aguda quanto de animais PI.The 5' untranslated region of the bovine viral diarrhea virus (BVDV genome was detected by RT-PCR assay in pools of blood sera samples collected from a cattle herd (n=226 animals with reproductive failures. Based on the classes of animal and the number of animals per class, the individual blood serum samples were distributed in 10 sera pools (A to J. During the first evaluation a 290bp amplicon was amplified in reactions from groups D (35 cows and H (25 sucking calves. The individual analysis

  9. Evaluation of RI images of hepatic blood flow using Tc-99m PMT

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Hiromichi; Iwasaki, Naoya; Ichikawa, Kesato

    1988-03-01

    To evaluate the clinical significance of RI images of hepatic blood flow using Tc-99m-PMT, analysis of the RI images and estimation of hepatic blood flow were carried out in patients with various liver diseases (37 cases). After intravenous injection of Tc-99m-PMT, hepatic accumulation curve of ROI positioned at whole liver area and time activity curve of ROI positioned at celiac artery were obtained through scintillation camera images with the computer-analysed system. Hepatic blood flow coefficient (K) was calculated from the hepatic accumulation curve. Based on the differential curve calculated from the time activity curve, chronological images of arterial, portal, parenchymal and saturated parenchymal phases were obtained. Results ; 1) K was 0.50 + 0.04, 0.35 + 0.02 and 0.26 + 0.04/min in normal type, CH type and LC type respectively. These coefficients well correlated with clinical severity of hepatic diseases. 2) Perfusional phase images of the liver became poorer in accordance with progression of liver disease, while images of spleen, portal venous system and collateral channels were more clearly obtained in liver cirrhosis. This method was shown to have a potential to understanding of severity of liver disease and hepatic blood flow dynamics.

  10. Hawaii ESI: POOLS (Anchialine Pool Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for anchialine pools in Hawaii. Anchialine pools are small, relatively shallow coastal ponds that occur...

  11. Micro-particle image velocimetry for velocity profile measurements of micro blood flows.

    Science.gov (United States)

    Pitts, Katie L; Fenech, Marianne

    2013-04-25

    Micro-particle image velocimetry (μPIV) is used to visualize paired images of micro particles seeded in blood flows. The images are cross-correlated to give an accurate velocity profile. A protocol is presented for μPIV measurements of blood flows in microchannels. At the scale of the microcirculation, blood cannot be considered a homogeneous fluid, as it is a suspension of flexible particles suspended in plasma, a Newtonian fluid. Shear rate, maximum velocity, velocity profile shape, and flow rate can be derived from these measurements. Several key parameters such as focal depth, particle concentration, and system compliance, are presented in order to ensure accurate, useful data along with examples and representative results for various hematocrits and flow conditions.

  12. Fast blood flow visualization of high-resolution laser speckle imaging data using graphics processing unit.

    Science.gov (United States)

    Liu, Shusen; Li, Pengcheng; Luo, Qingming

    2008-09-15

    Laser speckle contrast analysis (LASCA) is a non-invasive, full-field optical technique that produces two-dimensional map of blood flow in biological tissue by analyzing speckle images captured by CCD camera. Due to the heavy computation required for speckle contrast analysis, video frame rate visualization of blood flow which is essentially important for medical usage is hardly achieved for the high-resolution image data by using the CPU (Central Processing Unit) of an ordinary PC (Personal Computer). In this paper, we introduced GPU (Graphics Processing Unit) into our data processing framework of laser speckle contrast imaging to achieve fast and high-resolution blood flow visualization on PCs by exploiting the high floating-point processing power of commodity graphics hardware. By using GPU, a 12-60 fold performance enhancement is obtained in comparison to the optimized CPU implementations.

  13. Single photon emission CT perfusion imaging of cerebral blood flow of early syphilis patients

    Institute of Scientific and Technical Information of China (English)

    施辛; 吴锦昌; 刘增礼; 唐军; 苏玉华

    2003-01-01

    Objective To injvestigate the cerebral blood flow of patients with early syphilis. Methods 99Tcm-ECD as brain perfusion imaging agent was used in single photon emission computed tomography (SPECT) for 32 patients with early syphilis and 15 controls. Visual analyses were made on every BSPECT image. Results The 32 patients with early syphilis had general, patchy hypoperfusion of cerebral blood flow. Fourteen of the 32 patients had 48 episodes of marked patchy hypoperfusion of rCBF. The responsible areas of hypoperfusion in a patchy distribution involved the left frontal lobe (6 episodes), right frontal lobe (3), left parietal lobe (7), right parietal lobe (6), left temporal lobe (11), right temporal lobe (5), left occipital lobe (3), left basal ganglia (3), cerebellum (1), and nerve nuceus (1). No abnormality was found in the control group.Conclusions Cerebral blood flow abnormalities exist in patients with early syphilis. General patchy hypoperfusion on SPECT imaging is common.

  14. Multifunctional polyelectrolyte microcapsules as a contrast agent for photoacoustic imaging in blood.

    Science.gov (United States)

    Yashchenok, Alexey M; Jose, Jithin; Trochet, Philippe; Sukhorukov, Gleb B; Gorin, Dmitry A

    2016-08-01

    The polyelectrolyte microcapsules that can be accurate either visualized in biological media or in tissue would enhance their further in vivo application both as a carrier of active payloads and as a specific sensor. The immobilization of active species, for instance fluorescent dyes, quantum dots, metal nanoparticles, in polymeric shell enables visualization of capsules by optical imaging techniques in aqueous solution. However, for visualization of capsules in complex media an instrument with high contrast modality requires. Herein, we show for the first time photoacoustic imaging (PAI) of multifunctional microcapsules in water and in blood. The microcapsules exhibit greater photoacoustic intensity compare to microparticles with the same composition of polymeric shell presumably their higher thermal expansion. Photoacoustic intensity form microcapsules dispersed in blood displays an enhancement (2-fold) of signal compare to blood. Photoacoustic imaging of microcapsules might contribute to non-invasive carrier visualization and further their in vivo distribution.

  15. Optimizing {sup 18}F-FDG PET/CT imaging of vessel wall inflammation: the impact of {sup 18}F-FDG circulation time, injected dose, uptake parameters, and fasting blood glucose levels

    Energy Technology Data Exchange (ETDEWEB)

    Bucerius, Jan [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); University Hospital, RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany); Mani, Venkatesh; Fayad, Zahi A. [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Moncrieff, Colin [Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P.O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Machac, Josef [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Farkouh, Michael E. [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Cardiovascular Imaging Clinical Trials Unit, New York, NY (United States); Tawakol, Ahmed [Massachusetts General Hospital, Harvard University, Cardiac MR PET CT Program, Boston, MA (United States); Rudd, James H.F. [Cambridge University, Division of Cardiovascular Medicine, Cambridge (United Kingdom)

    2014-02-15

    {sup 18}F-FDG PET is increasingly used for imaging of vessel wall inflammation. However, limited data are available on the impact of methodological variables, i.e. prescan fasting glucose, FDG circulation time and injected FDG dose, and of different FDG uptake parameters, in vascular FDG PET imaging. Included in the study were 195 patients who underwent vascular FDG PET/CT of the aorta and the carotids. Arterial standardized uptake values ({sub mean}SUV{sub max}), target-to-background ratios ({sub mean}TBR{sub max}) and FDG blood-pool activity in the superior vena cava (SVC) and the jugular veins (JV) were quantified. Vascular FDG uptake values classified according to the tertiles of prescan fasting glucose levels, the FDG circulation time, and the injected FDG dose were compared using ANOVA. Multivariate regression analyses were performed to identify the potential impact of all variables described on the arterial and blood-pool FDG uptake. Tertile analyses revealed FDG circulation times of about 2.5 h and prescan glucose levels of less than 7.0 mmol/l, showing a favorable relationship between arterial and blood-pool FDG uptake. FDG circulation times showed negative associations with aortic{sub mean}SUV{sub max} values as well as SVC and JV FDG blood-pool activity, but positive correlations with aortic and carotid{sub mean}TBR{sub max} values. Prescan glucose levels were negatively associated with aortic and carotid{sub mean}TBR{sub max} and carotid{sub mean}SUV{sub max} values, but were positively correlated with SVC blood-pool uptake. The injected FDG dose failed to show any significant association with vascular FDG uptake. FDG circulation times and prescan blood glucose levels significantly affect FDG uptake in the aortic and carotid walls and may bias the results of image interpretation in patients undergoing vascular FDG PET/CT. The injected FDG dose was less critical. Therefore, circulation times of about 2.5 h and prescan glucose levels less than 7.0 mmol

  16. Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Handa H

    1999-02-01

    Full Text Available The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels were studied with percent flow volume (the ratio of actual flow volume to measured flow volume. The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries.

  17. Changes of renal blood flow after ESWL: Assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index

    Energy Technology Data Exchange (ETDEWEB)

    Abd Ellah, Mohamed, E-mail: dr_m_hamdy2006@hotmail.co [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Kremser, Christian, E-mail: christian.kremser@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pallwein, Leo, E-mail: leo.pallwein-prettner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Aigner, Friedrich, E-mail: friedrich.Aigner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Schocke, Michael, E-mail: michael.schocke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Peschel, Reinhard, E-mail: reinhard.peschel@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pedross, Florian, E-mail: florian.pedross@i-med.ac.a [Innsbruck Medical University, Medical Statistics Dept., Anich St. 35, 6020 Innsbruck (Austria); Pinggera, Germar-Michael, E-mail: germar.pinggera@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Wolf, Christian, E-mail: christian.wolf@bkh-reutte.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Alsharkawy, Mostafa A.M., E-mail: drmostafamri@yahoo.co [Assiut University, Radiology Dept., Assiut (Egypt); Jaschke, Werner, E-mail: werner.jaschke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Frauscher, Ferdinand, E-mail: ferdinand.frauscher@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria)

    2010-10-15

    The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12 h before and 12 h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p < 0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p < 0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

  18. Blood

    Science.gov (United States)

    ... Also, blood is either Rh-positive or Rh-negative. So if you have type A blood, it's either A positive or A negative. Which type you are is important if you need a blood transfusion. And your Rh factor could be important ...

  19. Radionuclide Tracers for Myocardial Perfusion Imaging and Blood Flow Quantification.

    Science.gov (United States)

    deKemp, Robert A; Renaud, Jennifer M; Klein, Ran; Beanlands, Rob S B

    2016-02-01

    Myocardial perfusion imaging is performed most commonly using Tc-99m-sestamibi or tetrofosmin SPECT as well as Rb-82-rubidium or N-13-ammonia PET. Diseased-to-normal tissue contrast is determined by the tracer retention fraction, which decreases nonlinearly with flow. Reduced tissue perfusion results in reduced tracer retention, but the severity of perfusion defects is typically underestimated by 20% to 40%. Compared to SPECT, retention of the PET tracers is more linearly related to flow, and therefore, the perfusion defects are measured more accurately using N-13-ammonia or Rb-82.

  20. Statistical analysis of polarizing maps of blood plasma laser images for the diagnostics of malignant formations

    Science.gov (United States)

    Ungurian, V. P.; Ivashchuk, O. I.; Ushenko, V. O.

    2012-01-01

    This work is aimed at searching the interconnections between the statistic structure of blood plasma microscopic images and manifestations of optical anisotropy of liquid crystal protein network. The model of linear birefringence of albumin and globulin crystals underlies in the ground of this work. The results of investigating the interrelation between statistical moments of the 1st-4th order are presented that characterize the coordinate distributions of polarization ellipticity of laser images of blood plasma smears and pathological changes in human organism. The diagnostic criteria of breast cancer nascency and its severity degree differentiation are determined.

  1. The singular approach for processing polarization-inhomogeneous laser images of blood plasma layers

    Science.gov (United States)

    Angelsky, P. O.; Ushenko, A. G.; Dubolazov, A. V.; Sidor, M. I.; Bodnar, G. B.; Koval, G.; Trifonyuk, L.

    2013-04-01

    We present in this work the results of an investigation to analyse the coordinate distributions of azimuths and ellipticity of polarization (polarization maps) in laser images of blood plasma layers for three groups of patients: healthy (group 1), mastopathy (group 2) and breast cancer (group 3). To characterize polarization maps for all groups of samples we use three groups of parameters: statistical moments of the first to fourth orders, autocorrelation functions and logarithmic dependences for power spectra related to distributions of azimuths and ellipticity of polarization inherent to laser images of blood plasma. We ascertain the criteria for diagnosis and differentiation of pathological changes of the breast.

  2. Semiquantitative imaging measurement of baseline and vasomodulated normal prostatic blood flow using sildenafil

    Science.gov (United States)

    Haaga, JR; Exner, A; Fei, B; Seftel, AD

    2013-01-01

    The physiologic variability of blood flow to the prostate has not been studied until this time. We report the vasoactive effects of sildenafil and phenylephrine on blood flow of the normal prostate. Sildenafil increases prostate blood flow by approximately 75% and phenylephrine reduces the flow incrementally. Administration of these drugs with dynamic contrast-enhanced magnetic resonance imaging may improve the diagnosis of cancerous tissue because according to the literature, tumor angiogenic vessels lack the vasoactive physiologic response of the normal tissue. PMID:16728965

  3. ABO Blood-Typing Using an Antibody Array Technique Based on Surface Plasmon Resonance Imaging

    Science.gov (United States)

    Houngkamhang, Nongluck; Vongsakulyanon, Apirom; Peungthum, Patjaree; Sudprasert, Krisda; Kitpoka, Pimpun; Kunakorn, Mongkol; Sutapun, Boonsong; Amarit, Ratthasart; Somboonkaew, Armote; Srikhirin, Toemsak

    2013-01-01

    In this study, readily available antibodies that are used in standard agglutination tests were evaluated for their use in ABO blood typing by a surface plasmon resonance imaging (SPR imaging) technique. Five groups of antibodies, including mixed clones of anti-A, anti-B, and anti-AB, and single clones of anti-A and anti-B, were used to construct the five-line detection arrays using a multichannel flow cell in the SPR imager. The red blood cell (RBC) samples were applied to a multichannel flow cell that was orthogonal to the detection line arrays for blood group typing. We found that the blood samples were correctly grouped in less than 12 min by the SPR imaging technique, and the results were consistent with those of the standard agglutination technique for all 60 samples. We found that mixed clones of antibodies provided 33%–68% greater change in the SPR signal than the single-clone antibodies. Applying the SPR imaging technique using readily available antibodies may reduce the costs of the antibodies, shorten the measurement time, and increase the throughput. PMID:24021965

  4. Investigation of atypical molten pool dynamics in tungsten carbide-cobalt during laser deposition using in-situ thermal imaging

    Science.gov (United States)

    Xiong, Yuhong; Hofmeister, William H.; Smugeresky, John E.; Delplanque, Jean-Pierre; Schoenung, Julie M.

    2012-01-01

    An atypical "swirling" phenomenon observed during the laser deposition of tungsten carbide-cobalt cermets by laser engineered net shaping (LENS®) was studied using in-situ high-speed thermal imaging. To provide fundamental insight into this phenomenon, the thermal behavior of pure cobalt during LENS was also investigated for comparison. Several factors were considered as the possible source of the observed differences. Of those, phase difference, material emissivity, momentum transfer, and free surface disruption from the powder jets, and, to a lesser extent, Marangoni convection were identified as the relevant mechanisms.

  5. Investigation of atypical molten pool dynamics in tungsten carbide-cobalt during laser deposition using in-situ thermal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Xiong Yuhong; Schoenung, Julie M. [Department of Chemical Engineering and Materials Science, University of California, Davis, California 95616 (United States); Hofmeister, William H. [Center for Laser Applications, University of Tennessee Space Institute, Tullahoma, Tennessee 37388 (United States); Smugeresky, John E. [Sandia National Laboratories, Livermore, California 94551 (United States); Delplanque, Jean-Pierre [Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616 (United States)

    2012-01-16

    An atypical ''swirling'' phenomenon observed during the laser deposition of tungsten carbide-cobalt cermets by laser engineered net shaping (LENS) was studied using in-situ high-speed thermal imaging. To provide fundamental insight into this phenomenon, the thermal behavior of pure cobalt during LENS was also investigated for comparison. Several factors were considered as the possible source of the observed differences. Of those, phase difference, material emissivity, momentum transfer, and free surface disruption from the powder jets, and, to a lesser extent, Marangoni convection were identified as the relevant mechanisms.

  6. High frame-rate blood vector velocity imaging using plane waves: simulations and preliminary experiments

    DEFF Research Database (Denmark)

    Udesen, J.; Gran, F.; Hansen, K.L.

    2008-01-01

    Conventional ultrasound methods for acquiring color images of blood velocity are limited by a relatively low frame-rate and are restricted to give velocity estimates along the ultrasound beam direction only. To circumvent these limitations, the method presented in this paper uses 3 techniques: 1...... carotid artery of a healthy male was scanned with a scan sequence that satisfies the limits set by the Food and Drug Administration. Vector velocity images were obtained with a frame-rate of 100 Hz where 40 speckle images are used for each vector velocity image. It was found that the blood flow...... approximately followed the vessel wall, and that maximum velocity was approximately 1 m/s, which is a normal value for a healthy person. To further evaluate the method, the test person was scanned with magnetic resonance (MR) angiography. The volume flow derived from the MR scanning was compared with that from...

  7. Indocyanine green fluorescence imaging for evaluation of uterine blood flow in cynomolgus macaque.

    Directory of Open Access Journals (Sweden)

    Iori Kisu

    Full Text Available BACKGROUND: Uterine blood flow is an important factor in uterine viability, but the number of blood vessels required to maintain viability is uncertain. In this study, indocyanine green (ICG fluorescence imaging was used to examine uterine hemodynamics and vessels associated with uterine blood flow in cynomolgus macaque. METHODS: The uterus of a female cynomolgus macaque was cut from the vaginal canal to mimic a situation during trachelectomy or uterine transplantation surgery in which uterine perfusion is maintained only with uterine and ovarian vessels. Intraoperative uterine hemodynamics was observed using ICG fluorescence imaging under conditions in which various nutrient vessels were selected by clamping of blood vessels. A time-intensity curve was plotted using imaging analysis software to measure the T(max of uterine perfusion for selected blood vessel patterns. Open surgery was performed with the uterus receiving nutritional support only from uterine vessels on one side. The size of the uterus after surgery was monitored using transabdominal ultrasonography. RESULTS: The resulting time-intensity curves displayed the average intensity in the regions of the uterine corpus and uterine cervix, and in the entire uterus. Analyses of the uterine hemodynamics in the cynomolgus macaque showed that uterine vessels were significantly related to uterine perfusion (P=0.008, whereas ovarian vessels did not have a significant relationship (P=0.588. When uterine vessels were clamped, ovarian vessels prolonged the time needed to reach perfusion maximum. Postoperative transabdominal ultrasonography showed that the size of the uterus was not changed 2 months after surgery, with recovery of periodic menstruation. The cynomolgus macaque has got pregnant with favorable fetus well-being. CONCLUSION: Uterine vessels may be responsible for uterine blood flow, and even one uterine vessel may be sufficient to maintain uterine viability in cynomolgus macaque. Our

  8. Relation of blood pressure and all-cause mortality in 180,000 Japanese participants: pooled analysis of 13 cohort studies.

    Science.gov (United States)

    Murakami, Yoshitaka; Hozawa, Atsushi; Okamura, Tomonori; Ueshima, Hirotsugu

    2008-06-01

    Hypertension is a leading cause of death because of cardiovascular disease and predominantly affects total mortality. To reduce avoidable deaths from hypertension, we need to collect blood pressure data and assess their impact on total mortality. To examine this issue, a meta-analysis of 13 cohort studies was conducted in Japan. Poisson regression was used for estimating all-cause mortality rates and ratios. In the model, blood pressure data were treated as continuous (10-mm Hg increase) and categorical (every 10 mm Hg) according to recommendations of the Seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension. Potential confounders included body mass index, smoking, drinking, and cohort. The impact of hypertension was measured by the population-attributable fraction. After excluding participants with cardiovascular disease history, 176 389 participants were examined in the analysis. Adjusted mortality rates became larger as the blood pressure increased, and these were more distinct in younger men and women. Hazard ratios also showed the same trends, and these trends were more apparent in younger men (hazard ratio [unit: 10-mm Hg increase] aged 40 to 49 years: systolic blood pressure 1.37 (range: 1.15 to 1.62); diastolic blood pressure 1.46 [range: 1.05 to 2.03]) than older ones (hazard ratio: aged 80 to 89 years: systolic blood pressure 1.09 [range: 1.05 to 1.13]and diastolic blood pressure 1.12 [range: 1.03 to 1.22]). Population-attributable fraction of hypertension was approximately 20% when the normal category was used as a reference level and was 10% when we included the prehypertension group in the reference level. In conclusion, high blood pressure raised the risk of total mortality, and this trend was higher in the younger Japanese population.

  9. Measuring cell surface area and deformability of individual human red blood cells over blood storage using quantitative phase imaging

    Science.gov (United States)

    Park, Hyunjoo; Lee, Sangyun; Ji, Misuk; Kim, Kyoohyun; Son, Yonghak; Jang, Seongsoo; Park, Yongkeun

    2016-10-01

    The functionality and viability of stored human red blood cells (RBCs) is an important clinical issue in transfusions. To systematically investigate changes in stored whole blood, the hematological properties of individual RBCs were quantified in blood samples stored for various periods with and without a preservation solution called citrate phosphate dextrose adenine-1 (CPDA-1). With 3-D quantitative phase imaging techniques, the optical measurements for 3-D refractive index (RI) distributions and membrane fluctuations were done at the individual cell level. From the optical measurements, the morphological (volume, surface area and sphericity), biochemical (hemoglobin content and concentration), and mechanical parameters (dynamic membrane fluctuation) were simultaneously quantified to investigate the functionalities and progressive alterations of stored RBCs. Our results show that stored RBCs without CPDA-1 had a dramatic morphological transformation from discocytes to spherocytes within two weeks which was accompanied by significant decreases in cell deformability and cell surface area, and increases in sphericity. However, the stored RBCs with CPDA-1 maintained their morphology and deformability for up to 6 weeks.

  10. Measuring blood delivery to solitary pulmonary nodules using perfusion magnetic resonance imaging

    Science.gov (United States)

    Zheng, Wei; Wang, Zhifeng; Shen, Li; Gao, Ling; Ford, James C.; Makedon, Fillia S.; Pearlman, Justin D.

    2006-03-01

    With perfusion magnetic resonance imaging (pMRI), perfusion describes the amount of blood passing through a block of tissue in a certain period of time. In pMRI, the tissue having more blood passing through will show higher intensity value as more contrast-labeled blood arrives. Perfusion reflects the delivery of essential nutrients to a block of tissue, and is an important parameter for the tissue status. Considering solitary pulmonary nodules (SPN), perfusion differences between malignant and benign nodules have been studied by different techniques. Much effort has been put into its characterization. In this paper, we proposed and implemented extraction of the SPN time intensity profile to measure blood delivery to solitary pulmonary nodules, describing their perfusion effects. In this method, a SPN time intensity profile is created based on intensity values of the solitary pulmonary nodule in lung pMRI images over time. This method has two steps: nodule tracking and profile clustering. Nodule tracking aligns the solitary pulmonary nodule in pMRI images taken at different time points, dealing with nodule movement resulted from breathing and body movement. Profile clustering implements segmentation of the nodule region and extraction of the time intensity profile of a solitary pulmonary nodule. SPN time intensity profiles reflect patterns of blood delivery to solitary pulmonary nodules, giving us a description of perfusion effect and indirect evidence of tumor angiogenesis. Analysis on SPN time intensity profiles will help the diagnosis of malignant nodules for early lung cancer detection.

  11. Improved tunable filter-based multispectral imaging system for detection of blood stains on construction material substrates

    Science.gov (United States)

    Janchaysang, Suwatwong; Sumriddetchkajorn, Sarun; Buranasiri, Prathan

    2013-06-01

    We present the improved tunable filter based multispectral imaging system for detecting blood stains on construction materials. Based upon the reflectance and Kubelka Munk absorbance spectra stocked from our previous work, we modify the blood discrimination criteria to make the system more efficient by replacing the old criteria which make use of polynomial fitting with new criteria associated with a few wavelengths images. The newly established criteria are tested to be able to detect blood against other stains almost as efficient as the old criteria, while the number of spectral images required for detecting blood stains are reduced significantly from 64 to 9 spectral images. The reduction of required spectral images will reduce the time needed for image capturing and blood detection criteria application with little sacrificing of the specificity and sensitivity of the system.

  12. Erythrocyte Features for Malaria Parasite Detection in Microscopic Images of Thin Blood Smear: A Review

    Directory of Open Access Journals (Sweden)

    Salam Shuleenda Devi

    2016-12-01

    Full Text Available Microscopic image analysis of blood smear plays a very important role in characterization of erythrocytes in screening of malaria parasites. The characteristics feature of erythrocyte changes due to malaria parasite infection. The microscopic features of the erythrocyte include morphology, intensity and texture. In this paper, the different features used to differentiate the non- infected and malaria infected erythrocyte have been reviewed.

  13. Ultrasonic imaging of foreign inclusions and blood vessels through thick skull bones.

    Science.gov (United States)

    Shapoori, Kiyanoosh; Sadler, Jeffrey; Ahmed, Zaki; Wydra, Adrian; Maeva, Elena; Malyarenko, Eugene; Maev, Roman

    2015-03-01

    We report a new progress in the development of a portable ultrasonic transcranial imaging system, which is expected to significantly improve the clinical utility of transcranial diagnostic ultrasound. When conventional ultrasonic phased array and Doppler techniques are applied through thick skull bones, the ultrasound field is attenuated, deflected, and defocused, leading to image distortion. To address these deficiencies, the ultrasonic transcranial imaging system implements two alternative ultrasonic methods. The first method improves detection of small foreign objects, such as bone fragments, pieces of shrapnel, or bullets, lodged in the brain tissue. Using adaptive beamforming, the method compensates for phase aberration induced by the skull and refocuses the distorted ultrasonic field at the desired location. The second method visualizes the blood flow through intact human skull using ultrasonic speckle reflections from the blood cells, platelets, or contrast agents. By analyzing these random temporal changes, it is possible to obtain 2D or 3D blood flow images, despite the adverse influence of the skull. Both methods were implemented on an advanced open platform phased array controller driving linear and matrix array probes. They were tested on realistic skull bone and head phantoms with foreign inclusions and blood vessel models.

  14. Photoacoustic imaging of blood vessels with a double-ring sensor featuring a narrow angular aperture

    NARCIS (Netherlands)

    Kolkman, Roy G.M.; Hondebrink, Erwin; Steenbergen, Wiendelt; Leeuwen, van Ton G.; Mul, de Frits F.M.

    2004-01-01

    A photoacoustic double-ring sensor, featuring a narrow angular aperture, is developed for laser-induced photoacoustic imaging of blood vessels. An integrated optical fiber enables reflection-mode detection of ultrasonic waves. By using the cross-correlation between the signals detected by the two ri

  15. Contrast enhancement of subcutaneous blood vessel images by means of visible and near-infrared hyper-spectral imaging

    Science.gov (United States)

    Katrašnik, Jaka; Bürmen, Miran; Pernuš, Franjo; Likar, Boštjan

    2009-02-01

    Visualization of subcutaneous veins is very difficult with the naked eye, but important for diagnosis of medical conditions and different medical procedures such as catheter insertion and blood withdrawal. Moreover, recent studies showed that the images of subcutaneous veins could be used for biometric identification. The majority of methods used for enhancing the contrast between the subcutaneous veins and surrounding tissue are based on simple imaging systems utilizing CMOS or CCD cameras with LED illumination capable of acquiring images from the near infrared spectral region, usually near 900 nm. However, such simplified imaging methods cannot exploit the full potential of the spectral information. In this paper, a new highly versatile method for enhancing the contrast of subcutaneous veins based on state-of-the-art high-resolution hyper-spectral imaging system utilizing the spectral region from 550 to 1700 nm is presented. First, a detailed analysis of the contrast between the subcutaneous veins and the surrounding tissue as a function of wavelength, for several different positions on the human arm, was performed in order to extract the spectral regions with the highest contrast. The highest contrast images were acquired at 1100 nm, however, combining the individual images from the extracted spectral regions by the proposed contrast enhancement method resulted in a single image with up to ten-fold better contrast. Therefore, the proposed method has proved to be a useful tool for visualization of subcutaneous veins.

  16. Doppler standard deviation imaging for clinical monitoring of in vivo human skin blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yonghua; Chen, Zhongping; Saxer, Christopher; Shen, Qimin; Xiang, Shaohua; Boer, Johannes F. de; Nelson, J. Stuart

    2000-09-15

    We used a novel phase-resolved optical Doppler tomographic (ODT) technique with very high flow-velocity sensitivity (10 {mu}m/s) and high spatial resolution (10 {mu}m) to image blood flow in port-wine stain (PWS) birthmarks in human skin. In addition to the regular ODT velocity and structural images, we use the variance of blood flow velocity to map the PWS vessels. Our device combines ODT and therapeutic systems such that PWS blood flow can be monitored in situ before and after laser treatment. To the authors' knowledge this is the first clinical application of ODT to provide a fast semiquantitative evaluation of the efficacy of PWS laser therapy in situ and in real time. (c) 2000 Optical Society of America.

  17. Defective mitochondrial respiration, altered dNTP pools and reduced AP endonuclease 1 activity in peripheral blood mononuclear cells of Alzheimer's disease patients

    DEFF Research Database (Denmark)

    Maynard, Scott; Hejl, Anne-Mette; Dinh, Tran Thuan Son;

    2015-01-01

    AIMS: Accurate biomarkers for early diagnosis of Alzheimer's disease (AD) are badly needed. Recent reports suggest that dysfunctional mitochondria and DNA damage are associated with AD development. In this report, we measured various cellular parameters, related to mitochondrial bioenergetics...... as possible. We measured glycolysis and mitochondrial respiration fluxes using the Seahorse Bioscience flux analyzer, mitochondrial ROS production using flow cytometry, dNTP levels by way of a DNA polymerization assay, DNA strand breaks using the Fluorometric detection of Alkaline DNA Unwinding (FADU) assay...... on adjustments for gender and/or age. CONCLUSIONS: This study reveals impaired mitochondrial respiration, altered dNTP pools and reduced DNA repair activity in PBMCs of AD patients, thus suggesting that these biochemical activities may be useful as biomarkers for AD....

  18. Preanalytical considerations in detection of colorectal cancer in blood serum using Raman molecular imaging (Conference Presentation)

    Science.gov (United States)

    Treado, Patrick J.; Stewart, Shona D.; Smith, Aaron; Kirschner, Heather; Post, Christopher; Overholt, Bergein F.

    2016-03-01

    Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. Raman Molecular Imaging (RMI) is an effective technique to evaluate human tissue, cells and bodily fluids, including blood serum for disease diagnosis. ChemImage Corporation, in collaboration with clinicians, has been engaged in development of an in vitro diagnostic Raman assay focused on CRC detection. The Raman Assay for Colorectal Cancer (RACC) exploits the high specificity of Raman imaging to distinguish diseased from normal dried blood serum droplets without additional reagents. Pilot Study results from testing of hundreds of biobank patient samples have demonstrated that RACC detects CRC with high sensitivity and specificity. However, expanded clinical trials, which are ongoing, are revealing a host of important preanalytical considerations associated with sample collection, sample storage and stability, sample shipping, sample preparation and sample interferents, which impact detection performance. Results from recent clinical studies will be presented.

  19. Laser speckle-imaging of blood microcirculation in the brain cortex of laboratory rats in stress

    Energy Technology Data Exchange (ETDEWEB)

    Vilensky, M A; Semyachkina-Glushkovskaya, Oxana V; Timoshina, P A; Kuznetsova, Jana V; Semyachkin-Glushkovskii, I A; Agafonov, Dmitry N; Tuchin, Valerii V

    2012-06-30

    The results of experimental approbation of the method of laser full-field speckle-imaging for monitoring the changes in blood microcirculation state of the brain cortex of laboratory rats under the conditions of developing stroke and administration of vasodilating and vasoconstrictive agents are presented. The studies aimed at the choice of the optimal conditions of speckle-image formation and recording were performed and the software implementing an adaptive algorithm for processing the data of measurements was created. The transfer of laser radiation to the probed region of the biotissue was implemented by means of a silica-polymer optical fibre. The problems and prospects of speckle-imaging of cerebral microcirculation of blood in laboratory and clinical conditions are discussed.

  20. Quantitative photothermal phase imaging of red blood cells using digital holographic photothermal microscope.

    Science.gov (United States)

    Vasudevan, Srivathsan; Chen, George C K; Lin, Zhiping; Ng, Beng Koon

    2015-05-10

    Photothermal microscopy (PTM), a noninvasive pump-probe high-resolution microscopy, has been applied as a bioimaging tool in many biomedical studies. PTM utilizes a conventional phase contrast microscope to obtain highly resolved photothermal images. However, phase information cannot be extracted from these photothermal images, as they are not quantitative. Moreover, the problem of halos inherent in conventional phase contrast microscopy needs to be tackled. Hence, a digital holographic photothermal microscopy technique is proposed as a solution to obtain quantitative phase images. The proposed technique is demonstrated by extracting phase values of red blood cells from their photothermal images. These phase values can potentially be used to determine the temperature distribution of the photothermal images, which is an important study in live cell monitoring applications.

  1. RECONSTRUCTION OF WELD POOL SURFACE BASED ON SHAPE FROM SHADING

    Institute of Scientific and Technical Information of China (English)

    DU Quanying; CHEN Shanben; LIN Tao

    2006-01-01

    A valid image-processing algorithm of weld pool surface reconstruction according to an input image of weld pool based on shape from shading (SFS) in computer vision is presented. The weld pool surface information is related to the backside weld width, which is crucial to the quality of weldjoint. The image of weld pool is recorded with an optical sensing method. Firstly, the reflectance map model, which specifies the imaging process, is estimated. Then, the algorithm of weld pool surface reconstruction based on SFS is implemented by iteration scheme and speeded by hierarchical structure. The results indicate the accuracy and effectiveness of the approach.

  2. A method to identify early ventricular dysfunction using resting gated blood pool scans (GBPS) in patients with coronary artery disease (CAD)

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzberg, R.J.; Seldin, D.W.; Johnson, L.L.; Alderson, P.O.

    1984-01-01

    To determine the sensitivity of regional 1st and 2nd time derivative (1DV, 2DV) images to assess ventricular function (VF) in CAD, the resting GBPS of 8 normal patients (pts) and 20 pts with CAD who had coronary angiography and contrast ventriculography (CV) were analyzed. The 1DV and 2DV of the systolic time-activity curve were determined for each left ventricular pixel in the GBPS. These values were displayed as functional images that were reviewed by three readers to determine the presence of regional abnormalities. No regional abnormalities were seen in the conventional GBPS or 1DV or 2DV images of the 8 normal pts. Regional GBPS and DV image abnormalities were seen in all 10 pts with CAD and abnormal wall motion by CV. The DV image abnormalities were in the distribution of 18/22 coronary arteries (CA) with greater than or equal to50% stenoses; 2 of these regions showed normal wall motion by CV and conventional GBPS. DV images were abnormal in 2/8 CAs without significant stenoses. In addition, regional DV image abnormalities were present in 9 of 10 pts with CAD who had normal wall motion and global ejection fraction by both CV and resting GBPS. These 10 pts showed regional abnormalities in the distribution of 13/15 CAs with significant stenoses and 2/15 CAs without such stenoses. The results suggest that time derivative functional images derived from resting GBPS provide a more sensitive means for detecting regional left ventricular dysfunction than several other current methods, especially in pts with mild CAD.

  3. Image-based red blood cell counter for multiple species of wild and domestic animals

    Directory of Open Access Journals (Sweden)

    C.R.M. Mauricio

    Full Text Available ABSTRACT RBC count plays an important role in animal diagnosis. Despite the many technologies available in different automated hematology analyzers, when it comes to the blood of wild animals it is still difficult to find an easy and affordable solution for multiple species. This study aims to evaluate the proposed automatic red blood cell counter. Blood samples (1 ocelot - Leopardus pardalis, 1 monkey - Cebus apella, 1 coati - Nasua nasua, 62 dogs - Canis familiaris, and 5 horses - Equus caballus were analyzed using three methods: 1-manual count, 2-automatic count by image, and 3-semi-automatic count by image; blood from dogs and horses were also analyzed by a fourth method: 4-automatic count by impedance. The counts in methods 2 and 3 were produced by the proposed red blood cell counter. Results were compared using Pearson's correlation and plots with different methods as the criterion standard. RBC counts in methods 1, 2, and 3 correlated very well with those in the method 4 (r ≥ 0.94. RBC counts produced by method 2 were highly correlated with method 3 (r = 0.998. The results indicate that the proposed method can be used as an automatic or semi-automatic counting method in clinics that are currently using the manual method for RBC assessment.

  4. Correlation between left ventricular diastolic function before and after valve replacement surgery and myocardial ultrastructural changes in patients with left ventricular volume-overloaded valvular heart diseases; Evaluation with gated blood pool scintigraphy using [sup 99m]Tc

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Tomiro (Okayama Univ. (Japan). School of Medicine)

    1993-06-01

    Left ventricular (LV) diastolic functions in 23 patients with aortic regurgitation (AR) and 22 patients with mitral regurgitation (MR) were evaluated by gated blood pool scintigraphy. LV myocardial biopsy was performed during open heart surgery, and LV myocardial ultrastructural changes were evaluated by electron microscope. Correlation between LV diastolic function and myocardial ultrastructural changes was examined. It was suggested that preoperative LV diastolic dysfunction occurred earlier than LV systolic dysfunction in patients with AR and MR. LV early diastolic dysfunction was especially significant in patients with AR. LV systolic function was significantly improved postoperatively compared with LV diastolic function in patients with AR and MR. It was suggested that LV interstitial fibrosis caused LV diastolic dysfunction in patients with AR and MR, and insufficiency of myocardial thickening as compensation in patients with MR. It was presumed that LV diastolic dysfunction was irreversible in patients with AR and MR in the distant postoperative period due to persistence of the preoperative myocardial ultrastructural change, e.g., interstitial fibrosis. These LV diastolic indices measured by gated pool scintigraphy were useful in predicting LV ultrastructural changes and postoperative LV dysfunction in patients with LV volume-overloaded valvular heart disease. (author).

  5. Measurement of cerebral blood flow using phase contrast magnetic resonance imaging and duplex ultrasonography.

    Science.gov (United States)

    Khan, Muhammad Ayaz; Liu, Jie; Tarumi, Takashi; Lawley, Justin Stevan; Liu, Peiying; Zhu, David C; Lu, Hanzhang; Zhang, Rong

    2017-02-01

    Phase contrast magnetic resonance imaging (PC-MRI) and color-coded duplex ultrasonography (CDUS) are commonly used for measuring cerebral blood flow in the internal carotid (ICA) and vertebral arteries. However, agreement between the two methods has been controversial. Recent development of high spatial and temporal resolution blood vessel wall edge-detection and wall-tracking methods with CDUS increased the accuracy and reliability of blood vessel diameter, hence cerebral blood flow measurement. The aim of this study was to compare the improved CDUS method with 3 T PC-MRI for cerebral blood flow measurements. We found that cerebral blood flow velocity measured in the ICA was lower using PC-MRI than CDUS (left ICA: PC-MRI, 18.0 ± 4.2 vs. CDUS, 25.6 ± 8.6 cm/s; right ICA: PC-MRI, 18.5 ± 4.8 vs. CDUS, 26.6 ± 6.7 cm/s, both p blood flow velocity measured in the left vertebral artery with PC-MRI was also lower than CDUS, but no differences in vertebral artery diameter were observed between the methods. Dynamic changes and/or intrinsic physiological fluctuations may have caused these differences in vessel diameter and velocity measurements between the methods. However, estimation of volumetric cerebral blood flow was similar and correlated between the methods despite the presence of large individual differences. These findings support the use of CDUS for cerebral blood flow measurements in the ICA and vertebral artery.

  6. Optical dynamic imaging of the regional blood flow in the rat mesentery under the effect of noradrenalin

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The regional blood flow in the rat mesentery under the effect of noradrenalin is monitored using the laser speckle imaging method. The results show that at the third minute of application of noradrenalin, the blood flow begins to decrease, and the venule blood flow decreases more rapidly than that in the arteriole. Five minutes later blood flow in part of blood vessels begins to resume and the blood flow in the arteriole recovers more quickly than that in the venule. These suggest that laser speckle imaging can obtain the temporal-spatial characteristic of blood flow in mesentery without the need of scanning. It provides a new approach for investigating the change of regional blood flow in the mesentery in microcirculation studies.

  7. Feasibility of the optical imaging of thrombus formation in a rotary blood pump by near-infrared light.

    Science.gov (United States)

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Nishida, Masahiro; Maruyama, Osamu

    2014-09-01

    Blood coagulation is one of the primary concerns when using mechanical circulatory support devices such as blood pumps. Noninvasive detection and imaging of thrombus formation is useful not only for the development of more hemocompatible devices but also for the management of blood coagulation to avoid risk of infarction. The objective of this study is to investigate the use of near-infrared light for imaging of thrombus formation in a rotary blood pump. The optical properties of a thrombus at wavelengths ranging from 600 to 750 nm were analyzed using a hyperspectral imaging (HSI) system. A specially designed hydrodynamically levitated centrifugal blood pump with a visible bottom area was used. In vitro antithrombogenic testing was conducted five times with the pump using bovine whole blood in which the activated blood clotting time was adjusted to 200 s prior to the experiment. Two halogen lights were used for the light sources. The forward scattering through the pump and backward scattering on the pump bottom area were imaged using the HSI system. HSI showed an increase in forward scattering at wavelengths ranging from 670 to 750 nm in the location of thrombus formation. The time at which the thrombus began to form in the impeller rotating at 2780 rpm could be detected. The spectral difference between the whole blood and the thrombus was utilized to image thrombus formation. The results indicate the feasibility of dynamically detecting and imaging thrombus formation in a rotary blood pump.

  8. Ghost Cell Suspensions as Blood Analogue Fluid for Macroscopic Particle Image Velocimetry Measurements.

    Science.gov (United States)

    Jansen, Sebastian V; Müller, Indra; Nachtsheim, Max; Schmitz-Rode, Thomas; Steinseifer, Ulrich

    2016-02-01

    Spatially resolved measurement of blood flow is of great interest in the development of artificial blood-carrying devices such as blood pumps, heart valve prostheses, and oxygenators. Particle image velocimetry (PIV) is able to measure instantaneous velocity fields in a plane with high accuracy and is being used more frequently for the development of such devices. However, as this measurement technique is based on optical access, blood flow at physiological hematocrit values is difficult to measure due to its low transparency and multiscattering properties. So far, only very small dimensions (in the range of 400 μm) can be measured using PIV. A suspension of ghost cells (GCs) offers a higher optical transparency than blood while having a similar rheological behavior. In this study, a procedure for the production of GC suspensions containing a very low intracellular hemoglobin concentration is presented. With the help of multiple rounds of controlled cell lysis, the intracellular hemoglobin concentration could be decreased to a point where a standard macroscopic PIV measurement was possible. A velocity profile of a 44% GC suspension in a circular channel with a diameter of 9.5 mm was measured with high spatial resolution. Meanwhile, the rheological behavior was found to be comparable with blood.

  9. Understanding Blood Counts

    Science.gov (United States)

    ... Lab and Imaging Tests Understanding Blood Counts Understanding Blood Counts Understanding Blood Counts SHARE: Print Glossary Blood cell counts give ... your blood that's occupied by red cells. Normal Blood Counts Normal blood counts fall within a range ...

  10. Full-field laser-Doppler imaging and its physiological significance for tissue blood perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Binzoni, T [Departement des Neurosciences Fondamentales, University of Geneva (Switzerland); Ville, D van de [Biomedical Imaging Group, Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland)], E-mail: Tiziano.Binzoni@medecine.unige.ch

    2008-12-07

    Using Monte Carlo simulations for a semi-infinite medium representing a skeletal muscle tissue, it is demonstrated that the zero- and first-order moments of the power spectrum for a representative pixel of a full-field laser-Doppler imager behave differently from classical laser-Doppler flowmetry. In particular, the zero-order moment has a very low sensitivity to tissue blood volume changes, and it becomes completely insensitive if the probability for a photon to interact with a moving red blood cell is above 0.05. It is shown that the loss in sensitivity is due to the strong forward scatter of the propagating photons in biological tissues (i.e., anisotropy factor g = 0.9). The first-order moment is linearly related to the root mean square of the red blood cell velocity (the Brownian component), and there is also a positive relationship with tissue blood volume. The most common physiological interpretation of the first-order moment is as tissue blood volume times expectation of the blood velocity (in probabilistic terms). In this sense, the use of the first-order moment appears to be a reasonable approach for qualitative real-time blood flow monitoring, but it does not allow us to obtain information on blood velocity or volume independently. Finally, it is shown that the spatial and temporal resolution trade-off imposed by the CMOS detectors, used in full-field laser-Doppler hardware, may lead to measurements that vary oppositely with the underlying physiological quantities. Further improvements on detectors' sampling rate will overcome this limitation.

  11. Full-field laser Doppler imaging and its physiological significance for tissue blood perfusion

    Science.gov (United States)

    Binzoni, T.; Van DeVille, D.

    2008-12-01

    Using Monte Carlo simulations for a semi-infinite medium representing a skeletal muscle tissue, it is demonstrated that the zero- and first-order moments of the power spectrum for a representative pixel of a full-field laser-Doppler imager behave differently from classical laser-Doppler flowmetry. In particular, the zero-order moment has a very low sensitivity to tissue blood volume changes, and it becomes completely insensitive if the probability for a photon to interact with a moving red blood cell is above 0.05. It is shown that the loss in sensitivity is due to the strong forward scatter of the propagating photons in biological tissues (i.e., anisotropy factor g = 0.9). The first-order moment is linearly related to the root mean square of the red blood cell velocity (the Brownian component), and there is also a positive relationship with tissue blood volume. The most common physiological interpretation of the first-order moment is as tissue blood volume times expectation of the blood velocity (in probabilistic terms). In this sense, the use of the first-order moment appears to be a reasonable approach for qualitative real-time blood flow monitoring, but it does not allow us to obtain information on blood velocity or volume independently. Finally, it is shown that the spatial and temporal resolution trade-off imposed by the CMOS detectors, used in full-field laser-Doppler hardware, may lead to measurements that vary oppositely with the underlying physiological quantities. Further improvements on detectors' sampling rate will overcome this limitation.

  12. A Pulsatile Flow Phantom for Image-Guided HIFU Hemostasis of Blood Vessels

    Science.gov (United States)

    Greaby, Robyn; Vaezy, Shahram

    2005-03-01

    A pulsatile flow phantom for studying ultrasound image-guided acoustic hemostasis in a controlled environment has been developed. An ex vivo porcine carotid artery was attached to the phantom and embedded in a visually and ultrasonically transparent gel. Heparinized porcine blood was pumped through the phantom. Power-Doppler and B-mode ultrasound were used to remotely target the HIFU focus to the site of a needle puncture. In nine trials, complete hemostasis was achieved after an average HIFU application of 55 +/- 34 seconds. The vessels remained patent after treatment. With this phantom, it will be possible to do controlled studies of ultrasound image-guided acoustic hemostasis.

  13. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    Science.gov (United States)

    Tzoumas, Stratis; Nunes, Antonio; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2016-06-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation, an effect that causes spectral corruption. Spectral corruption has limited the quantification accuracy of optical and optoacoustic spectroscopic methods, and impeded the goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical goal for the assessment of oxygenation in physiological processes and disease. Here we describe light fluence in the spectral domain and introduce eigenspectra multispectral optoacoustic tomography (eMSOT) to account for wavelength-dependent light attenuation, and estimate blood sO2 within deep tissue. We validate eMSOT in simulations, phantoms and animal measurements and spatially resolve sO2 in muscle and tumours, validating our measurements with histology data. eMSOT shows substantial sO2 accuracy enhancement over previous optoacoustic methods, potentially serving as a valuable tool for imaging tissue pathophysiology.

  14. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    Science.gov (United States)

    Tzoumas, Stratis; Nunes, Antonio; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2016-01-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation, an effect that causes spectral corruption. Spectral corruption has limited the quantification accuracy of optical and optoacoustic spectroscopic methods, and impeded the goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical goal for the assessment of oxygenation in physiological processes and disease. Here we describe light fluence in the spectral domain and introduce eigenspectra multispectral optoacoustic tomography (eMSOT) to account for wavelength-dependent light attenuation, and estimate blood sO2 within deep tissue. We validate eMSOT in simulations, phantoms and animal measurements and spatially resolve sO2 in muscle and tumours, validating our measurements with histology data. eMSOT shows substantial sO2 accuracy enhancement over previous optoacoustic methods, potentially serving as a valuable tool for imaging tissue pathophysiology. PMID:27358000

  15. Blood flow activation in rat somatosensory cortex under sciatic nerve stimulation revealed by laser speckle imaging

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In many functional neuroimaging research the change of local cerebral blood flow (CBF) induced by sensory stimulation is regarded as an indicator of the change in cortical neuronal activity although a precise and full spatio-temporal description of local CBF response coupled to neural activity has still not been laid out. Using the laser speckle imaging technique a relatively large exposed area in somatosensory cortex of rat was imaged for the observation of the variations of CBF during sciatic nerve stimulation. The results showed that cerebral blood flow activation was spatially localized and discretely distributed in the targeted microvasculature. Individual arteries, veins and capillaries in different diameters were activated with the time going. The response pattern of CBF related to the function of brain activity and energy metabolism is delineated exactly.

  16. A rapid method for counting nucleated erythrocytes on stained blood smears by digital image analysis

    Science.gov (United States)

    Gering, E.; Atkinson, C.T.

    2004-01-01

    Measures of parasitemia by intraerythrocytic hematozoan parasites are normally expressed as the number of infected erythrocytes per n erythrocytes and are notoriously tedious and time consuming to measure. We describe a protocol for generating rapid counts of nucleated erythrocytes from digital micrographs of thin blood smears that can be used to estimate intensity of hematozoan infections in nonmammalian vertebrate hosts. This method takes advantage of the bold contrast and relatively uniform size and morphology of erythrocyte nuclei on Giemsa-stained blood smears and uses ImageJ, a java-based image analysis program developed at the U.S. National Institutes of Health and available on the internet, to recognize and count these nuclei. This technique makes feasible rapid and accurate counts of total erythrocytes in large numbers of microscope fields, which can be used in the calculation of peripheral parasitemias in low-intensity infections.

  17. High Frame-Rate Blood Vector Velocity Imaging Using Plane Waves: Simulations and Preliminary Experiments

    DEFF Research Database (Denmark)

    Udesen, Jesper; Gran, Fredrik; Hansen, Kristoffer Lindskov;

    2008-01-01

    Conventional ultrasound methods for acquiring color images of blood velocity are limited by a relatively low frame-rate and are restricted to give velocity estimates along the ultrasound beam direction only. To circumvent these limitations, the method presented in this paper uses 3 techniques: 1......) The ultrasound is not focused during the transmissions of the ultrasound signals; 2) A 13-bit Barker code is transmitted simultaneously from each transducer element; and 3) The 2-D vector velocity of the blood is estimated using 2-D cross-correlation. A parameter study was performed using the Field II program......, and performance of the method was investigated when a virtual blood vessel was scanned by a linear array transducer. An improved parameter set for the method was identified from the parameter study, and a flow rig measurement was performed using the same improved setup as in the simulations. Finally, the common...

  18. Laser speckle contrast imaging for monitoring changes in microvascular blood flow

    DEFF Research Database (Denmark)

    Ambrus, Rikard; Strandby, Rune B.; Svendsen, Lars Bo;

    2016-01-01

    BACKGROUND/AIMS: Microvascular blood flow is essential for healing and predicts surgical outcome. The aim of the current study was to investigate the relation between fluxes measured with the laser speckle contrast imaging (LSCI) technique and changes in absolute blood flow. In addition, we studied...... the reproducibility of the LSCI technique when assessing the intra-abdominal microcirculation of the pig. METHODS: During trial 1, a fish gill arch was mechanically perfused with heparinized fish blood under controlled stepwise-altered flow rates alongside mechanically induced movement artefacts. The microcirculation...... = 6.0, 3.2, and 6.4%, respectively). CONCLUSION: Due to the non-contact and real-time assessment over large areas, LSCI is a promising technique for the intraoperative assessment of intra-abdominal microcirculation. A linear correlation between flux and volumetric flow was found, in accordance...

  19. Swimming pool cleaner poisoning

    Science.gov (United States)

    Swimming pool cleaner poisoning occurs when someone swallows this type of cleaner, touches it, or breathes in ... The harmful substances in swimming pool cleaner are: Bromine ... copper Chlorine Soda ash Sodium bicarbonate Various mild acids

  20. Evaluation of blood pressure reduction response and responder characteristics to fixed-dose combination treatment of amlodipine and losartan: a post hoc analysis of pooled clinical trials.

    Science.gov (United States)

    Unniachan, Sreevalsa; Wu, David; Rajagopalan, Srinivasan; Hanson, Mary E; Fujita, Kenji P

    2014-09-01

    Data from four clinical trials compared reductions in systolic blood pressure (SBP) and diastolic blood pressure (DBP) among patients treated with amlodipine/losartan 5/50 mg vs 5/100 mg and amlodipine/losartan 5/50 mg vs amlodipine 5 mg and 10 mg. Response rate was assessed as reduction in SBP or DBP (>20/10 mm Hg) and proportion of patients achieving SBP SBP and DBP. Mean SBP and DBP were reduced in amlodipine/losartan 5/50 mg (n=182) and amlodipine/losartan 5/100 mg (n=95) users across all baseline quartiles. Patients using amlodipine/losartan 5/50 mg had significantly greater SBP and DBP reductions vs amlodipine 5 mg (P=.001 and P=.02, respectively). Amlodipine/losartan 5/50 mg users had significantly greater SBP reduction vs amlodipine 10 mg (SBP P=.02; DBP P=not significant). The odds of responding to therapy were significantly greater with amlodipine/losartan 5/50 mg vs amlodipine 5 mg (odds ratio, 5.33; 95% confidence interval, 1.42-25.5) and were similar vs amlodipine 10 mg (odds ratio, 0.67; 95% confidence interval, 0.017-9.51). These results support the use of combination therapy early in the treatment of hypertension.

  1. Complete blood cell count in psittaciformes by using high-throughput image cytometry: a pilot study.

    Science.gov (United States)

    Beaufrère, Hugues; Ammersbach, Mélanie; Tully, Thomas N

    2013-09-01

    The avian hemogram is usually performed in veterinary diagnostic laboratories by using manual cell counting techniques and differential counts determined by light microscopy. There is no standard automated technique for avian blood cell count and differentiation to date. These shortcomings in birds are primarily because erythrocytes and thrombocytes are nucleated, which precludes the use of automated analyzers programmed to perform mammal complete blood cell counts. In addition, there is no standard avian antibody panel, which would allow cell differentiation by immunophenotyping across all commonly seen bird species. We report an alternative hematologic approach for quantification and differentiation of avian blood cells by using high-throughput image cytometry on blood smears in psittacine bird species. A pilot study was designed with 70 blood smears of different psittacine bird species stained with a Wright-Giemsa stain. The slides were scanned at 0.23 microm/pixel. The open-source softwares CellProfiler and CellProfiler Analyst were used for analyzing and sorting each cell by image cytometry. A "pipeline" was constructed in the CellProfiler by using different modules to identify and export hundreds of measures per cell for shape, intensity, and texture. Rules for classifying the different blood cell phenotypes were then determined based on these measurements by iterative feedback and machine learning by using CellProfiler Analyst. Although this approach shows promises, avian Leukopet results could not be duplicated when using this technique as is. Further studies and more standardized prospective investigations may be needed to refine the "pipeline" strategy and the machine learning algorithm.

  2. Laser Doppler blood flow complementary metal oxide semiconductor imaging sensor with analog on-chip processing.

    Science.gov (United States)

    Gu, Quan; Hayes-Gill, Barrie R; Morgan, Stephen P

    2008-04-20

    A 4 x 4 pixel array with analog on-chip processing has been fabricated within a 0.35 mum complementary metal oxide semiconductor process as a prototype sensor for laser Doppler blood flow imaging. At each pixel the bandpass and frequency weighted filters necessary for processing laser Doppler blood flow signals have been designed and fabricated. Because of the space constraints of implementing an accurate omega(0.5) filter at the pixel level, this has been approximated using the "roll off" of a high-pass filter with a cutoff frequency set at 10 kHz. The sensor has been characterized using a modulated laser source. Fixed pattern noise is present that is demonstrated to be repeatable across the array and can be calibrated. Preliminary blood flow results on a finger before and after occlusion demonstrate that the sensor array provides the potential for a system that can be scaled to a larger number of pixels for blood flow imaging.

  3. C-arm flat detector computed tomography parenchymal blood volume imaging: the nature of parenchymal blood volume parameter and the feasibility of parenchymal blood volume imaging in aneurysmal subarachnoid haemorrhage patients

    Energy Technology Data Exchange (ETDEWEB)

    Kamran, Mudassar; Byrne, James V. [University of Oxford, Nuffield Department of Surgical Sciences, Oxford (United Kingdom)

    2015-09-15

    C-arm flat detector computed tomography (FDCT) parenchymal blood volume (PBV) measurements allow assessment of cerebral haemodynamics in the neurointerventional suite. This paper explores the feasibility of C-arm computed tomography (CT) PBV imaging and the relationship between the C-arm CT PBV and the MR-PWI-derived cerebral blood volume (CBV) and cerebral blood flow (CBF) parameters in aneurysmal subarachnoid haemorrhage (SAH) patients developing delayed cerebral ischemia (DCI). Twenty-six patients with DCI following aneurysmal SAH underwent a research C-arm CT PBV scan using a biplane angiography system and contemporaneous MR-PWI scan as part of a prospective study. Quantitative whole-brain atlas-based volume-of-interest analysis in conjunction with Pearson correlation and Bland-Altman tests was performed to explore the agreement between C-arm CT PBV and MR-derived CBV and CBF measurements. All patients received medical management, while eight patients (31 %) underwent selective intra-arterial chemical angioplasty. Colour-coded C-arm CT PBV maps were 91 % sensitive and 100 % specific in detecting the perfusion abnormalities. C-arm CT rPBV demonstrated good agreement and strong correlation with both MR-rCBV and MR-rCBF measurements; the agreement and correlation were stronger for MR-rCBF relative to MR-rCBV and improved for C-arm CT PBV versus the geometric mean of MR-rCBV and MR-rCBF. Analysis of weighted means showed that the C-arm CT PBV has a preferential blood flow weighting (∼60 % blood flow and ∼40 % blood volume weighting). C-arm CT PBV imaging is feasible in DCI following aneurysmal SAH. PBV is a composite perfusion parameter incorporating both blood flow and blood volume weightings. That PBV has preferential (∼60 %) blood flow weighting is an important finding, which is of clinical significance when interpreting the C-arm CT PBV maps, particularly in the setting of acute brain ischemia. (orig.)

  4. The science of pooling

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, E.

    1995-10-01

    The pooling of data from radon studies is described. Pooling refers to the analysis of original data from several studies, not meta-analysis in which summary measures from published data are analyzed. A main objective for pooling is to reduce uncertainty and to obtain more precise estimates of risk than would be available from any single study.

  5. Skeletonization algorithm-based blood vessel quantification using in vivo 3D photoacoustic imaging

    Science.gov (United States)

    Meiburger, K. M.; Nam, S. Y.; Chung, E.; Suggs, L. J.; Emelianov, S. Y.; Molinari, F.

    2016-11-01

    Blood vessels are the only system to provide nutrients and oxygen to every part of the body. Many diseases can have significant effects on blood vessel formation, so that the vascular network can be a cue to assess malicious tumor and ischemic tissues. Various imaging techniques can visualize blood vessel structure, but their applications are often constrained by either expensive costs, contrast agents, ionizing radiations, or a combination of the above. Photoacoustic imaging combines the high-contrast and spectroscopic-based specificity of optical imaging with the high spatial resolution of ultrasound imaging, and image contrast depends on optical absorption. This enables the detection of light absorbing chromophores such as hemoglobin with a greater penetration depth compared to purely optical techniques. We present here a skeletonization algorithm for vessel architectural analysis using non-invasive photoacoustic 3D images acquired without the administration of any exogenous contrast agents. 3D photoacoustic images were acquired on rats (n  =  4) in two different time points: before and after a burn surgery. A skeletonization technique based on the application of a vesselness filter and medial axis extraction is proposed to extract the vessel structure from the image data and six vascular parameters (number of vascular trees (NT), vascular density (VD), number of branches (NB), 2D distance metric (DM), inflection count metric (ICM), and sum of angles metric (SOAM)) were calculated from the skeleton. The parameters were compared (1) in locations with and without the burn wound on the same day and (2) in the same anatomic location before (control) and after the burn surgery. Four out of the six descriptors were statistically different (VD, NB, DM, ICM, p  <  0.05) when comparing two anatomic locations on the same day and when considering the same anatomic location at two separate times (i.e. before and after burn surgery). The study demonstrates an

  6. Preliminary evaluation of magnetic resonance fresh blood imaging for diagnosis of Budd-Chiari syndrome

    Institute of Scientific and Technical Information of China (English)

    REN Ke; XU Ke; SUN Wen-ge; CHEN Yu-shuai; QI Xi-xun; LI Ran-liang; JIN An-yu

    2007-01-01

    Background Budd-Chiari syndrome (BCS) is a rare disease with portal hypertension caused by the blockage of the hepatic vein and/or the inferior vena cava (IVC). Angiography is the "golden standard" for diagnosis, but it is an invasive examination. To assess the diagnostic value of a fresh blood imaging (FBI) relative to BCS, we used a magnetic resonance angiography (MRA) with an FBI sequence for a preoperative evaluation of the BCS patients in this study. Methods Fifty patients who were suspected of having BCS after they had been checked by a B-ultrasound were studied. 2D and 3D FBI were performed on a 1.5T superconductive MR scanner. Original images were rebuilt using a maximal intensity projection (MIP) method on the console. Two doctors reviewed all images before they learned of the angiography results. We then compared the diagnoses obtained from the FBI and angiography results to evaluate the diagnostic value of the FBI.Results Forty-one patients were diagnosed as BCS and 9 as non-BCS based on an angiography. The FBI correctly diagnosed 38 patients, incorrectly diagnosed 1 patient, and missed diagnosis in 3 patients. Thus, the diagnostic sensitivity of the FBI is 93% (38/41), the specificity is 89% (8/9) and the accuracy is 92% (46/50). The FBI images of the 13 membranous stenoses of the IVC showed a sudden stenosis of the post-liver segment of the IVC. The Images of the 5 patients with a membranous obstruction of the IVC showed IVC thickening and an absence of blood signals in the post-hepatic segment of the IVC. The images of the 4 patients with the segmental thrombosis of the IVC showed abnormal and intermittent signals in the IVC. The images of the 6 patients with a simple hepatic vein obstruction showed obstructive hepatic veins. The images of the 6 patients with the stenosis of both the IVC and the hepatic veins showed the stenosis of the IVC, the thickening of the hepatic veins and the formation of a compensatory circulation within the liver. Lastly

  7. Evaluation of tumor blood flow after feeder embolization in meningiomas by arterial spin-labeling perfusion magnetic resonance imaging.

    Science.gov (United States)

    Kawaji, Hiroshi; Koizumi, Shinichiro; Sakai, Naoto; Yamasaki, Tomohiro; Hiramatsu, Hisaya; Kanoko, Yusuke; Kamiya, Mika; Yamashita, Shuhei; Takehara, Yasuo; Sakahara, Harumi; Namba, Hiroki

    2013-10-01

    Preoperative embolization changes the amount of blood flow and pattern of flow distribution in meningioma. Tumor blood flow was investigated in eight meningioma patients before and after embolization using arterial spin-labeling (ASL) perfusion imaging. Although blood flow was significantly reduced in the whole tumor after embolization, changes in flow distribution patterns varied from one case to another. The findings suggest that evaluation of post-embolization tumor blood flow by ASL perfusion imaging would be useful in the surgical planning of meningioma.

  8. Non invasive blood flow assessment in diabetic foot ulcer using laser speckle contrast imaging technique

    Science.gov (United States)

    Jayanthy, A. K.; Sujatha, N.; Reddy, M. Ramasubba; Narayanamoorthy, V. B.

    2014-03-01

    Measuring microcirculatory tissue blood perfusion is of interest for both clinicians and researchers in a wide range of applications and can provide essential information of the progress of treatment of certain diseases which causes either an increased or decreased blood flow. Diabetic ulcer associated with alterations in tissue blood flow is the most common cause of non-traumatic lower extremity amputations. A technique which can detect the onset of ulcer and provide essential information on the progress of the treatment of ulcer would be of great help to the clinicians. A noninvasive, noncontact and whole field laser speckle contrast imaging (LSCI) technique has been described in this paper which is used to assess the changes in blood flow in diabetic ulcer affected areas of the foot. The blood flow assessment at the wound site can provide critical information on the efficiency and progress of the treatment given to the diabetic ulcer subjects. The technique may also potentially fulfill a significant need in diabetic foot ulcer screening and management.

  9. Inter-Slice Blood Flow and Magnetization Transfer Effects as A New Simultaneous Imaging Strategy.

    Directory of Open Access Journals (Sweden)

    Paul Kyu Han

    Full Text Available The recent blood flow and magnetization transfer (MT technique termed alternate ascending/descending directional navigation (ALADDIN achieves the contrast using interslice blood flow and MT effects with no separate preparation RF pulse, thereby potentially overcoming limitations of conventional methods. In this study, we examined the signal characteristics of ALADDIN as a simultaneous blood flow and MT imaging strategy, by comparing it with pseudo-continuous ASL (pCASL and conventional MT asymmetry (MTA methods, all of which had the same bSSFP readout. Bloch-equation simulations and experiments showed ALADDIN perfusion signals increased with flip angle, whereas MTA signals peaked at flip angle around 45°-60°. ALADDIN provided signals comparable to those of pCASL and conventional MTA methods emulating the first, second, and third prior slices of ALADDIN under the same scan conditions, suggesting ALADDIN signals to be superposition of signals from multiple labeling planes. The quantitative cerebral blood flow signals from a modified continuous ASL model overestimated the perfusion signals compared to those measured with a pulsed ASL method. Simultaneous mapping of blood flow, MTA, and MT ratio in the whole brain is feasible with ALADDIN within a clinically reasonable time, which can potentially help diagnosis of various diseases.

  10. Advanced contrast nanoagents for photoacoustic molecular imaging, cytometry, blood test and photothermal theranostics.

    Science.gov (United States)

    de la Zerda, Adam; Kim, Jin-Woo; Galanzha, Ekaterina I; Gambhir, Sanjiv S; Zharov, Vladimir P

    2011-01-01

    Various nanoparticles have raised significant interest over the past decades for their unique physical and optical properties and biological utilities. Here we summarize the vast applications of advanced nanoparticles with a focus on carbon nanotube (CNT)-based or CNT-catalyzed contrast agents for photoacoustic (PA) imaging, cytometry and theranostics applications based on the photothermal (PT) effect. We briefly review the safety and potential toxicity of the PA/PT contrast nanoagents, while showing how the physical properties as well as multiple biological coatings change their toxicity profiles and contrasts. We provide general guidelines needed for the validation of a new molecular imaging agent in living subjects, and exemplify these guidelines with single-walled CNTs targeted to α(v) β(3) , an integrin associated with tumor angiogenesis, and golden carbon nanotubes targeted to LYVE-1, endothelial lymphatic receptors. An extensive review of the potential applications of advanced contrast agents is provided, including imaging of static targets such as tumor angiogenesis receptors, in vivo cytometry of dynamic targets such as circulating tumor cells and nanoparticles in blood, lymph, bones and plants, methods to enhance the PA and PT effects with transient and stationary bubble conjugates, PT/PA Raman imaging and multispectral histology. Finally, theranostic applications are reviewed, including the nanophotothermolysis of individual tumor cells and bacteria with clustered nanoparticles, nanothrombolysis of blood clots, detection and purging metastasis in sentinel lymph nodes, spectral hole burning and multiplex therapy with ultrasharp rainbow nanoparticles.

  11. Frequency-domain photothermoacoustic and ultrasonic imaging of blood and opto-thermal effects of plasmonic nanoparticle concentrations

    Science.gov (United States)

    Khosroshahi, Mohammad E.; Mandelis, Andreas; Lashkari, Bahman

    2015-07-01

    We describe the use of combined ultrasonic imaging (USI) and photoacoustic radar imaging (PARI) with linear chirp laser modulation to provide visualization of blood with and without the use of gold nanoparticles. A blood vessel simulating sample (S1) containing pure sheep blood was shown to be an optically weak absorbing medium which satisfies thermal but not acoustic confinement. On the contrary, the blood-gold combinations (S2) using 10% and S3 (20%) Au concentrations behaved as optically strongly absorbing media. A heating efficiency of 0.54 to 8.60×103 K cm2 J-1 was determined for Au NPs. The optimal optical power modulation spectral density was determined to be in the range of 0.5 to 0.8 MHz and 0.3 to 1.0 MHz for USI and PARI, respectively. USI produced a better structural image while PARI produced a better functional image of the simulated blood vessel in the order of S2>S3>S1 due to enhanced signal-to-noise ratio. Two-dimensional images of the simulated blood vessel were also obtained. In summary, the PA signal does not increase linearly with Au NP concentration and the change of blood osmolarity due to temperature increase can cause thermo-hemolysis of red blood cells which in turn degrades the PA signal and thus the blood imaging quality. On the other hand, USI produced the best structural image, S4, due to the strong US reflection response from Au NPs and its insensitivity to the presence of blood.

  12. Mobile phone based laser speckle contrast imager for assessment of skin blood flow

    Science.gov (United States)

    Jakovels, Dainis; Saknite, Inga; Krievina, Gita; Zaharans, Janis; Spigulis, Janis

    2014-10-01

    Assessment of skin blood flow is of interest for evaluation of skin viability as well as for reflection of the overall condition of the circulatory system. Laser Doppler perfusion imaging (LDPI) and laser speckle contrast imaging (LASCI) are optical techniques used for assessment of skin perfusion. However, these systems are still too expensive and bulky to be widely available. Implementation of such techniques as connection kits for mobile phones have a potential for primary diagnostics. In this work we demonstrate simple and low cost LASCI connection kit for mobile phone and its comparison to laser Doppler perfusion imager. Post-occlusive hyperemia and local thermal hyperemia tests are used to compare both techniques and to demonstrate the potential of LASCI device.

  13. Integrated quantitative phase and birefringence microscopy for imaging malaria-infected red blood cells

    Science.gov (United States)

    Li, Chengshuai; Chen, Shichao; Klemba, Michael; Zhu, Yizheng

    2016-09-01

    A dual-modality birefringence/phase imaging system is presented. The system features a crystal retarder that provides polarization mixing and generates two interferometric carrier waves in a single signal spectrum. The retardation and orientation of sample birefringence can then be measured simultaneously based on spectral multiplexing interferometry. Further, with the addition of a Nomarski prism, the same setup can be used for quantitative differential interference contrast (DIC) imaging. Sample phase can then be obtained with two-dimensional integration. In addition, birefringence-induced phase error can be corrected using the birefringence data. This dual-modality approach is analyzed theoretically with Jones calculus and validated experimentally with malaria-infected red blood cells. The system generates not only corrected DIC and phase images, but a birefringence map that highlights the distribution of hemozoin crystals.

  14. Total 3D imaging of phase objects using defocusing microscopy: application to red blood cells

    CERN Document Server

    Roma, P M S; Amaral, F T; Agero, U; Mesquita, O N

    2014-01-01

    We present Defocusing Microscopy (DM), a bright-field optical microscopy technique able to perform total 3D imaging of transparent objects. By total 3D imaging we mean the determination of the actual shapes of the upper and lower surfaces of a phase object. We propose a new methodology using DM and apply it to red blood cells subject to different osmolality conditions: hypotonic, isotonic and hypertonic solutions. For each situation the shape of the upper and lower cell surface-membranes (lipid bilayer/cytoskeleton) are completely recovered, displaying the deformation of RBCs surfaces due to adhesion on the glass-substrate. The axial resolution of our technique allowed us to image surface-membranes separated by distances as small as 300 nm. Finally, we determine volume, superficial area, sphericity index and RBCs refractive index for each osmotic condition.

  15. Multiscale imaging and computational modeling of blood flow in the tumor vasculature.

    Science.gov (United States)

    Kim, Eugene; Stamatelos, Spyros; Cebulla, Jana; Bhujwalla, Zaver M; Popel, Aleksander S; Pathak, Arvind P

    2012-11-01

    The evolution in our understanding of tumor angiogenesis has been the result of pioneering imaging and computational modeling studies spanning the endothelial cell, microvasculature and tissue levels. Many of these primary data on the tumor vasculature are in the form of images from pre-clinical tumor models that provide a wealth of qualitative and quantitative information in many dimensions and across different spatial scales. However, until recently, the visualization of changes in the tumor vasculature across spatial scales remained a challenge due to a lack of techniques for integrating micro- and macroscopic imaging data. Furthermore, the paucity of three-dimensional (3-D) tumor vascular data in conjunction with the challenges in obtaining such data from patients presents a serious hurdle for the development and validation of predictive, multiscale computational models of tumor angiogenesis. In this review, we discuss the development of multiscale models of tumor angiogenesis, new imaging techniques capable of reproducing the 3-D tumor vascular architecture with high fidelity, and the emergence of "image-based models" of tumor blood flow and molecular transport. Collectively, these developments are helping us gain a fundamental understanding of the cellular and molecular regulation of tumor angiogenesis that will benefit the development of new cancer therapies. Eventually, we expect this exciting integration of multiscale imaging and mathematical modeling to have widespread application beyond the tumor vasculature to other diseases involving a pathological vasculature, such as stroke and spinal cord injury.

  16. Blood pressure and fasting lipid changes after 24 weeks’ treatment with vildagliptin: a pooled analysis in >2,000 previously drug-naïve patients with type 2 diabetes mellitus

    Science.gov (United States)

    Evans, Marc; Schweizer, Anja; Foley, James E

    2016-01-01

    Introduction We have previously shown modest weight loss with vildagliptin treatment. Since body weight balance is associated with changes in blood pressure (BP) and fasting lipids, we have assessed these parameters following vildagliptin treatment. Methods Data were pooled from all double-blind, randomized, controlled, vildagliptin mono-therapy trials on previously drug-naïve patients with type 2 diabetes mellitus who received vildagliptin 50 mg once daily (qd) or twice daily (bid; n=2,108) and wherein BP and fasting lipid data were obtained. Results Data from patients receiving vildagliptin 50 mg qd or bid showed reductions from baseline to week 24 in systolic BP (from 132.5±0.32 to 129.8±0.34 mmHg; P<0.0001), diastolic BP (from 81.2±0.18 to 79.6±0.19 mmHg; P<0.0001), fasting triglycerides (from 2.00±0.02 to 1.80±0.02 mmol/L; P<0.0001), very low density lipoprotein cholesterol (from 0.90±0.01 to 0.83±0.01 mmol/L; P<0.0001), and low density lipoprotein cholesterol (from 3.17±0.02 to 3.04±0.02 mmol/L; P<0.0001), whereas high density lipoprotein cholesterol increased (from 1.19±0.01 to 1.22±0.01 mmol/L; P<0.001). Weight decreased by 0.48±0.08 kg (P<0.001). Conclusion This large pooled analysis demonstrated that vildagliptin shows a significant reduction in BP and a favorable fasting lipid profile that are associated with modest weight loss. PMID:27574437

  17. Improved Perfusion MR Imaging Assessment of Intracerebral Tumor Blood Volume and Antiangiogenic Therapy Efficacy in a Rat Model with Ferumoxytol

    OpenAIRE

    Gahramanov, Seymur; Muldoon, Leslie L; Li, Xin; Neuwelt, Edward A.

    2011-01-01

    Our findings suggest that, at perfusion MR imaging, more consistent estimations of relative cerebral blood volume are provided with ferumoxytol than with gadolinium-based contrast agents regardless of the permeability of the tumor vasculature.

  18. The Diagnostic Value of Superb Microvascular Imaging (SMI) in Detecting Blood Flow Signals of Breast Lesions

    Science.gov (United States)

    Ma, Yan; Li, Gang; Li, Jing; Ren, Wei-dong

    2015-01-01

    Abstract The correlation between color Doppler flow imaging (CDFI) and Superb Microvascular Imaging (SMI) for detecting blood flow in breast lesions was investigated, as was the diagnostic value of SMI in differentiating benign from malignant breast lesions. These lesions were evaluated using both CDFI and SMI according to Adler's method. Pathologic examination showed 57 malignant lesions and 66 benign lesions. The number of blood vessels in a single mass was detected by 2 techniques (SMI and CDFI), and the difference between the 2 values (SMI-CDFI) was calculated. The optimal threshold for the diagnosis of malignant neoplasms and the diagnostic performances of SMI, CDFI, and SMI-CDFI were calculated. For the total lesions and malignant lesions alone, the difference between SMI and CDFI for detecting blood flow was significant (P < 0.01), but the difference was not significant for benign lesions (P = 0.15). The area under the receiver operating characteristic curve was 0.73 (95% confidence interval [CI]: 0.64–0.82) for CDFI; 0.81 (95% CI: 0.74–0.89) for SMI; and 0.89 (95% CI: 0.82–0.95) for SMI-CDFI. Furthermore, the modality of “SMI-CDFI” showed the best diagnostic performance. SMI provides further microvessel information in breast lesions. The diagnostic modality of “SMI-CDFI” can improve the diagnostic performance of ultrasound in the differentiation between benign and malignant masses. PMID:26356718

  19. Inverse Problem for Color Doppler Ultrasound-Assisted Intracardiac Blood Flow Imaging

    Directory of Open Access Journals (Sweden)

    Jaeseong Jang

    2016-01-01

    Full Text Available For the assessment of the left ventricle (LV, echocardiography has been widely used to visualize and quantify geometrical variations of LV. However, echocardiographic image itself is not sufficient to describe a swirling pattern which is a characteristic blood flow pattern inside LV without any treatment on the image. We propose a mathematical framework based on an inverse problem for three-dimensional (3D LV blood flow reconstruction. The reconstruction model combines the incompressible Navier-Stokes equations with one-direction velocity component of the synthetic flow data (or color Doppler data from the forward simulation (or measurement. Moreover, time-varying LV boundaries are extracted from the intensity data to determine boundary conditions of the reconstruction model. Forward simulations of intracardiac blood flow are performed using a fluid-structure interaction model in order to obtain synthetic flow data. The proposed model significantly reduces the local and global errors of the reconstructed flow fields. We demonstrate the feasibility and potential usefulness of the proposed reconstruction model in predicting dynamic swirling patterns inside the LV over a cardiac cycle.

  20. Thermography-based blood flow imaging in human skin of the hands and feet: a spectral filtering approach.

    Science.gov (United States)

    Sagaidachnyi, A A; Fomin, A V; Usanov, D A; Skripal, A V

    2017-02-01

    The determination of the relationship between skin blood flow and skin temperature dynamics is the main problem in thermography-based blood flow imaging. Oscillations in skin blood flow are the source of thermal waves propagating from micro-vessels toward the skin's surface, as assumed in this study. This hypothesis allows us to use equations for the attenuation and dispersion of thermal waves for converting the temperature signal into the blood flow signal, and vice versa. We developed a spectral filtering approach (SFA), which is a new technique for thermography-based blood flow imaging. In contrast to other processing techniques, the SFA implies calculations in the spectral domain rather than in the time domain. Therefore, it eliminates the need to solve differential equations. The developed technique was verified within 0.005-0.1 Hz, including the endothelial, neurogenic and myogenic frequency bands of blood flow oscillations. The algorithm for an inverse conversion of the blood flow signal into the skin temperature signal is addressed. The examples of blood flow imaging of hands during cuff occlusion and feet during heating of the back are illustrated. The processing of infrared (IR) thermograms using the SFA allowed us to restore the blood flow signals and achieve correlations of about 0.8 with a waveform of a photoplethysmographic signal. The prospective applications of the thermography-based blood flow imaging technique include non-contact monitoring of the blood supply during engraftment of skin flaps and burns healing, as well the use of contact temperature sensors to monitor low-frequency oscillations of peripheral blood flow.

  1. Deriving a blood-mimicking fluid for particle image velocimetry in Sylgard-184 vascular models.

    Science.gov (United States)

    Yousif, Majid Y; Holdsworth, David W; Poepping, Tamie L

    2009-01-01

    A new blood-mimicking fluid (BMF) has been developed for particle image velocimetry (PIV), which enables flow studies in vascular models (phantoms). A major difficulty in PIV that affects measurement accuracy is the refraction and distortion of light passing through the interface between the model and the fluid, due to the difference in refractive index (n) between the two materials. The problem can be eliminated by using a fluid with a refractive index matching that of the model. Such fluids are not commonly available, especially for vascular research where the fluid should also have a viscosity similar to human blood. In this work, a blood-mimicking fluid, composed of water (47.38% by weight), glycerol (36.94% by weight) and sodium iodide salt (15.68% by weight), was developed for compatibility with our silicone (Sylgard 184; n = 1.414) phantoms. The fluid exhibits a dynamic viscosity of 4.31+/-0.03 cP which lies within the range of human blood viscosity (4.4+/-0.6 cP). Both refractive index and viscosity were attained at 22.2+/-0.2 degrees C, which is a feasible room temperature, thus eliminating the need for a temperature-control system. The fluid will be used to study hemodynamics in vascular flow models fabricated from Sylgard 184.

  2. Imaging transient blood vessel fusion events in zebrafish by correlative volume electron microscopy.

    Directory of Open Access Journals (Sweden)

    Hannah E J Armer

    Full Text Available The study of biological processes has become increasingly reliant on obtaining high-resolution spatial and temporal data through imaging techniques. As researchers demand molecular resolution of cellular events in the context of whole organisms, correlation of non-invasive live-organism imaging with electron microscopy in complex three-dimensional samples becomes critical. The developing blood vessels of vertebrates form a highly complex network which cannot be imaged at high resolution using traditional methods. Here we show that the point of fusion between growing blood vessels of transgenic zebrafish, identified in live confocal microscopy, can subsequently be traced through the structure of the organism using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM and Serial Block Face/Scanning Electron Microscopy (SBF/SEM. The resulting data give unprecedented microanatomical detail of the zebrafish and, for the first time, allow visualization of the ultrastructure of a time-limited biological event within the context of a whole organism.

  3. The system spatial-frequency filtering of birefringence images of human blood layers

    Science.gov (United States)

    Ushenko, A. G.; Boychuk, T. M.; Mincer, O. P.; Angelsky, P. O.; Bodnar, N. B.; Oleinichenko, B. P.; Bizer, L. I.

    2013-09-01

    Among various opticophysical methods [1 - 3] of diagnosing the structure and properties of the optical anisotropic component of various biological objects a specific trend has been singled out - multidimensional laser polarimetry of microscopic images of the biological tissues with the following statistic, correlative and fractal analysis of the coordinate distributions of the azimuths and ellipticity of polarization in approximating of linear birefringence polycrystalline protein networks [4 - 10]. At the same time, in most cases, experimental obtaining of tissue sample is a traumatic biopsy operation. In addition, the mechanisms of transformation of the state of polarization of laser radiation by means of the opticoanisotropic biological structures are more varied (optical dichroism, circular birefringence). Hereat, real polycrystalline networks can be formed by different types, both in size and optical properties of biological crystals. Finally, much more accessible for an experimental investigation are biological fluids such as blood, bile, urine, and others. Thus, further progress of laser polarimetry can be associated with the development of new methods of analysis and processing (selection) of polarization- heterogeneous images of biological tissues and fluids, taking into account a wider set of mechanisms anisotropic mechanisms. Our research is aimed at developing experimental method of the Fourier polarimetry and a spatialfrequency selection for distributions of the azimuth and the ellipticity polarization of blood plasma laser images with a view of diagnosing prostate cancer.

  4. A spectral-spatial fusion model for robust blood pulse waveform extraction in photoplethysmographic imaging

    CERN Document Server

    Amelard, Robert; Wong, Alexander

    2016-01-01

    Photoplethysmographic imaging is a camera-based solution for non-contact cardiovascular monitoring from a distance. This technology enables monitoring in situations where contact-based devices may be problematic or infeasible, such as ambulatory, sleep, and multi-individual monitoring. However, extracting the blood pulse waveform signal is challenging due to the unknown mixture of relevant (pulsatile) and irrelevant pixels in the scene. Here, we design and implement a signal fusion framework, FusionPPG, for extracting a blood pulse waveform signal with strong temporal fidelity from a scene without requiring anatomical priors (e.g., facial tracking). The extraction problem is posed as a Bayesian least squares fusion problem, and solved using a novel probabilistic pulsatility model that incorporates both physiologically derived spectral and spatial waveform priors to identify pulsatility characteristics in the scene. Experimental results show statistically significantly improvements compared to the FaceMeanPPG ...

  5. Holographic intravital microscopy for 2-D and 3-D imaging intact circulating blood cells in microcapillaries of live mice

    Science.gov (United States)

    Kim, Kyoohyun; Choe, Kibaek; Park, Inwon; Kim, Pilhan; Park, Yongkeun

    2016-09-01

    Intravital microscopy is an essential tool that reveals behaviours of live cells under conditions close to natural physiological states. So far, although various approaches for imaging cells in vivo have been proposed, most require the use of labelling and also provide only qualitative imaging information. Holographic imaging approach based on measuring the refractive index distributions of cells, however, circumvent these problems and offer quantitative and label-free imaging capability. Here, we demonstrate in vivo two- and three-dimensional holographic imaging of circulating blood cells in intact microcapillaries of live mice. The measured refractive index distributions of blood cells provide morphological and biochemical properties including three-dimensional cell shape, haemoglobin concentration, and haemoglobin contents at the individual cell level. With the present method, alterations in blood flow dynamics in live healthy and sepsis-model mice were also investigated.

  6. Holographic intravital microscopy for 2-D and 3-D imaging intact circulating blood cells in microcapillaries of live mice

    CERN Document Server

    Kim, Kyoohyun; Park, Inwon; Kim, Pilhan; Park, YongKeun

    2016-01-01

    Intravital microscopy is an essential tool that reveals behaviours of live cells under conditions close to natural physiological states. So far, although various approaches for imaging cells in vivo have been proposed, most require the use of labelling and also provide only qualitative imaging information. Holographic imaging approach based on measuring the refractive index distributions of cells, however, circumvent these problems and offer quantitative and label-free imaging capability. Here, we demonstrate in vivo two- and three-dimensional holographic imaging of circulating blood cells in intact microcapillaries of live mice. The measured refractive index distributions of blood cells provide morphological and biochemical properties including three-dimensional cell shape, haemoglobin concentration, and haemoglobin contents at the individual cell level. With the present method, alterations in blood flow dynamics in live healthy and sepsis-model mouse were also investigated.

  7. PET imaging of blood flow and glucose metabolism in localized musculoskeletal tumors of the extremities

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Paula, E-mail: paula.lindholm@tyks.f [Department of Oncology and Radiotherapy, Turku University Hospital, Turku FI-20521 (Finland); Turku PET Centre, Turku (Finland); Sutinen, Eija [Department of Oncology and Radiotherapy, Turku University Hospital, Turku FI-20521 (Finland); Turku PET Centre, Turku (Finland); Oikonen, Vesa [Turku PET Centre, Turku (Finland); Mattila, Kimmo [Department of Radiology, Turku University Hospital, Turku FI-20521 (Finland); Tarkkanen, Maija [Department of Oncology, Helsinki University Central Hospital, Helsinki (Finland); Kallajoki, Markku [Department of Pathology, Turku University Hospital, Turku FI-20521 (Finland); Aro, Hannu [Department of Orthopaedic Surgery, Turku University Hospital, Turku FI-20521 (Finland); Boehling, Tom [Department of Pathology, Helsinki University Central Hospital, Helsinki (Finland); Kivioja, Aarne [Department of Orthopaedic Surgery, Helsinki University Central Hospital, Helsinki, FI-00029 (Finland); Elomaa, Inkeri [Department of Oncology, Helsinki University Central Hospital, Helsinki (Finland); Minn, Heikki [Department of Oncology and Radiotherapy, Turku University Hospital, Turku FI-20521 (Finland); Turku PET Centre, Turku (Finland)

    2011-02-15

    Introduction: Little is known about blood flow in sarcomas. Our purpose was to study glucose metabolism and blood flow in untreated localized musculoskeletal tumors of the extremities using [{sup 18}F]fluorodeoxyglucose (FDG), oxygen-15 labeled water ([15O]H{sub 2}O) and positron emission tomography (PET). Methods: Six patients with high-grade osteosarcoma (OS), two with soft-tissue sarcoma (STS) and one with aneurysmal bone cyst had PET studies with [15O]H{sub 2}O and FDG. Arterial blood sampling and autoradiography calculation method were used to define blood flow as milliliters per 100 g times minutes. Tumor FDG uptake was measured as standardized uptake values (SUVs) and regional metabolic rates for FDG (rMRFDG). Two patients also had FDG PET studies during (one patient) and after (two patients) preoperative chemotherapy. All patients underwent dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The PET findings were compared with the clinical follow-up data and results of DCE-MRI. Results: Blood flow in bone tumors was 31.7-75.2 ml/(100 gxmin) and in STS 9.0-45.9 ml/(100 gxmin). [{sup 18}F]-Fluorodeoxyglucose uptake and rMRFDG in untreated bone tumors were 5.4-18.4 and 10.9-57.4 {mu}mol/100 g/min, respectively. [{sup 18}F]-Fluorodeoxyglucose uptake and rMRFDG in STS were 2.6-11.5 and 5.6-32.2 {mu}mol/100 g/min, respectively. Four of five sarcomas with SUV>9.0 have already relapsed. High blood flow in untreated OS was related to long overall survival, while the predictive power of glucose metabolism was less apparent. Good histopathological response to therapy was not associated with long survival. Conclusions: Measurement of blood flow in musculoskeletal tumors appears to be feasible by PET and [{sup 15}O]H{sub 2}O. The influence of tumor blood flow and glucose metabolism on the final outcome in sarcoma is variable and needs further research.

  8. Pulsatile microvascular blood flow imaging by short-time Fourier transform analysis of ultrafast laser holographic interferometry

    CERN Document Server

    Puyo, L; Rancillac, A; Simonutti, M; Paques, M; Sahel, J A; Fink, M; Atlan, M

    2015-01-01

    We report on wide-field imaging of pulsatile microvascular blood flow in the exposed cerebral cortex of a mouse by holographic interferometry. We recorded interferograms of laser light backscattered by the tissue, beating against an off-axis reference beam with a 50 kHz framerate camera. Videos of local Doppler contrasts were rendered numerically by Fresnel transformation and short-time Fourier transform analysis. This approach enabled instantaneous imaging of pulsatile blood flow contrasts in superficial blood vessels over 256 x 256 pixels with a spatial resolution of 10 microns and a temporal resolution of 20 ms.

  9. Retinal blood flow velocity in patients with active uveitis using the retinal function imager

    Institute of Scientific and Technical Information of China (English)

    FENG Xing; Kedhar Sanjay; Bhoomibunchoo Chavakij

    2013-01-01

    Background Previous studies suggest a link between macular edema and retinal blood flow velocity (RBFV).The effects of inflammation in the retinal blood vessels are not clearly understood.We want to evaluate the differences in retinal blood flow velocities of patients with active uveitis and healthy controls using the retinal function imager (RFI)and determine the correlation between retinal blood flow veiocity and central macular thickness in uveitis patients.Methods Twenty-eight eyes of 24 patients with active anterior uveitis and 51 eyes of 51 normal control subjects were enrolled.Retinal blood flow velocities evaluated by RFI and central macular thickness evaluated by optical coherence tomography (SLO-OCT) were obtained.Differences among the groups were assessed using Stata statistical software.Results Ten eyes had uveitic cystoid macular edema (CME).Median (first quartile,third quartile) venous velocity for uveitic eyes with CME,uveitic eyes without CME,and controls were 2.09 (1.92,2.44),2.64 (2.32,2.86),and 2.82 (2.39,3.53) mm/s respectively.Median (first and quartile) arterial velocity for uveitic eyes with CME,uveitic eyes without CME,and controls were 3.79 (3.61,4.09),3.46 (2.86,4.12),and 3.93 (3.35,4.65) mm/s.Uveitic eyes with CME had significantly lower venous velocity than controls (P=0.044).There was a strong linear relationship between venous velocity and central retinal thickness (P=-0.007).Conclusions Retinal venous velocities were significantly decreased in eyes with uveitic CME relative to controls.Decreased venous velocity was correlated with increased central retinal thickness in uveitic eyes.

  10. Quantification of myocardial blood flow with {sup 82}Rb dynamic PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lortie, Mireille; Beanlands, Rob S.B.; Yoshinaga, Keiichiro; Klein, Ran; DaSilva, Jean N.; DeKemp, Robert A. [University of Ottawa Heart Institute, Cardiac PET Centre, Ottawa, ON (Canada)

    2007-11-15

    The PET tracer {sup 82}Rb is commonly used to evaluate regional perfusion defects for the diagnosis of coronary artery disease. There is limited information on the quantification of myocardial blood flow and flow reserve with this tracer. The goal of this study was to investigate the use of a one-compartment model of {sup 82}Rb kinetics for the quantification of myocardial blood flow. Fourteen healthy volunteers underwent rest and dipyridamole stress imaging with both {sup 13}N-ammonia and {sup 82}Rb within a 2-week interval. Myocardial blood flow was estimated from the time-activity curves measured with {sup 13}N-ammonia using a standard two-compartment model. The uptake parameter of the one-compartment model was estimated from the time-activity curves measured with {sup 82}Rb. To describe the relationship between myocardial blood flow and the uptake parameter, a nonlinear extraction function was fitted to the data. This function was then used to convert estimates of the uptake parameter to flow estimates. The extraction function was validated with an independent data set obtained from 13 subjects with documented evidence of coronary artery disease (CAD). The one-compartment model described {sup 82}Rb kinetics very well (median R-square = 0.98). The flow estimates obtained with {sup 82}Rb were well correlated with those obtained with {sup 13}N-ammonia (r = 0.85), and the best-fit line did not differ significantly from the identity line. Data obtained from the subjects with CAD confirmed the validity of the estimated extraction function. It is possible to obtain accurate estimates of myocardial blood flow and flow reserve with a one-compartment model of {sup 82}Rb kinetics and a nonlinear extraction function. (orig.)

  11. Fluorescence endoscopic imaging for evaluation of gastric mucosal blood flow: a preliminary study

    Science.gov (United States)

    Bocquillon, Nicolas; Mordon, Serge R.; Mathieu, D.; Maunoury, Vincent; Marechal, Xavier-Marie; Neviere, Remi; Wattel, Francis; Chopin, Claude

    1999-02-01

    Microcirculatory disorders of the gastrointestinal tract appear to be a major compound of the multiple organ dysfunction syndrome secondary to sepsis or septic shock. A better analysis of mucosal hypoperfusion in critically ill patients with sepsis may be helpful for the comprehension of this high mortality-associated syndrome. Fluorescence endoscopy has been recognized as a non-invasive method for both spatial and temporal evaluation of gastrointestinal mucosal perfusion. We performed this imaging technique during routine gastric endoscopy in patients with sepsis criteria. The study included gastric observation and appearance time of gastric fluorescence after an intravenous 10% sodium - fluorescein bolus. Qualitative analysis of high fluorescence areas was compared with mucosal blood flow measurements by laser - Doppler flowmetry. We concluded that the fluorescence endoscopic imaging in critically ill patients with sepsis may reveal spacial and temporal differences in the mucosal microcirculation distribution.

  12. Comparative imaging of differential pulmonary blood flow in patients with congenital heart disease: magnetic resonance imaging versus lung perfusion scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Roman, Kevin S. [Hospital for Sick Children, Department of Cardiology, Toronto, ON (Canada); Kellenberger, Christian J.; Farooq, Saqba; MacGowan, Christopher K.; Gilday, David L.; Yoo, Shi-Joon [Hospital for Sick Children, Diagnostic Imaging and Radiology, Toronto, ON (Canada)

    2005-03-01

    Lung perfusion scintigraphy is considered the gold standard to assess differential pulmonary blood flow while magnetic resonance (MR) has been shown to be an accurate alternative in some studies. The purpose of the study was to assess the accuracy of phase contrast magnetic resonance (PC-MR) in measuring pulmonary blood flow ratio compared with lung perfusion scintigraphy in patients with complex pulmonary artery anatomy or pulmonary hypertension and to document reasons for discrepant results. We identified 25 cases of congenital heart disease between January 2000 and 2003, in whom both techniques of assessing pulmonary blood flow were performed within a 6-month period without an interim surgical or transcatheter intervention. The study group included cases with branch pulmonary artery stenosis, intracardiac shunts, single ventricle circulation, pulmonary venous anomalies and conotruncal defects. The mean age at study was 5.7 years (range 0.33-12) with a mean weight of 20.3 kg (range 6.5-53.6). The two methods were compared using a Bland-Altman analysis, and the Pearson correlation coefficient was calculated using the lung scan as the gold standard. Discrepant results were examined by reviewing the source images to elucidate reasons for error by MR. Bland-Altman analysis comparing right pulmonary artery (RPA) blood flow percentage, as measured by each modality, showed a mean difference of 1.43{+-}9.8 (95% limits of agreement: -17.8, 20.6) with a correlation coefficient of r=0.84, P<0.0001. In six (24%) cases a large difference (>10%) was found with a mean difference between techniques of 17.9%. The reasons for discrepant results included MR artifacts, dephasing owing to turbulent flow, site of data acquisition and lobar lung collapse. When using PC-MR to assess pulmonary blood flow ratio, important technical errors occur in a significant proportion of patients who have abnormal pulmonary artery anatomy or pulmonary hypertension. If these technical errors are

  13. Reliable enumeration of malaria parasites in thick blood films using digital image analysis

    Directory of Open Access Journals (Sweden)

    Frean John A

    2009-09-01

    Full Text Available Abstract Background Quantitation of malaria parasite density is an important component of laboratory diagnosis of malaria. Microscopy of Giemsa-stained thick blood films is the conventional method for parasite enumeration. Accurate and reproducible parasite counts are difficult to achieve, because of inherent technical limitations and human inconsistency. Inaccurate parasite density estimation may have adverse clinical and therapeutic implications for patients, and for endpoints of clinical trials of anti-malarial vaccines or drugs. Digital image analysis provides an opportunity to improve performance of parasite density quantitation. Methods Accurate manual parasite counts were done on 497 images of a range of thick blood films with varying densities of malaria parasites, to establish a uniformly reliable standard against which to assess the digital technique. By utilizing descriptive statistical parameters of parasite size frequency distributions, particle counting algorithms of the digital image analysis programme were semi-automatically adapted to variations in parasite size, shape and staining characteristics, to produce optimum signal/noise ratios. Results A reliable counting process was developed that requires no operator decisions that might bias the outcome. Digital counts were highly correlated with manual counts for medium to high parasite densities, and slightly less well correlated with conventional counts. At low densities (fewer than 6 parasites per analysed image signal/noise ratios were compromised and correlation between digital and manual counts was poor. Conventional counts were consistently lower than both digital and manual counts. Conclusion Using open-access software and avoiding custom programming or any special operator intervention, accurate digital counts were obtained, particularly at high parasite densities that are difficult to count conventionally. The technique is potentially useful for laboratories that

  14. Brain oxygen saturation assessment in neonates using T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy.

    Science.gov (United States)

    Alderliesten, Thomas; De Vis, Jill B; Lemmers, Petra Ma; Hendrikse, Jeroen; Groenendaal, Floris; van Bel, Frank; Benders, Manon Jnl; Petersen, Esben T

    2017-03-01

    Although near-infrared spectroscopy is increasingly being used to monitor cerebral oxygenation in neonates, it has a limited penetration depth. The T2-prepared Blood Imaging of Oxygen Saturation (T2-BIOS) magnetic resonance sequence provides an oxygen saturation estimate on a voxel-by-voxel basis, without needing a respiratory calibration experiment. In 15 neonates, oxygen saturation measured by T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy were compared. In addition, these measures were compared to cerebral blood flow and venous oxygen saturation in the sagittal sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy ( R(2 )= 0.64, p infrared spectroscopy oxygen saturation, and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus ( R(2 )= 0.71, 0.50, 0.65; p infrared spectroscopy and T2-prepared blood imaging of oxygen saturation, confirming the validity of using of these techniques for determining cerebral oxygenation.

  15. Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

    Directory of Open Access Journals (Sweden)

    Xu Zhiliang

    2010-01-01

    Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

  16. Infrared tomography for diagnostic imaging of port wine stain blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The objective of this work is the development of Infrared Tomography (IRT) for detecting and characterizing subsurface chromophores in human skin. Characterization of cutaneous chromophores is crucial for advances in the laser treatment of pigmented lesions (e.g., port wine stain birthmarks and tatoos). Infrared tomography (IRT) uses a fast infrared focal plane array (IR-FPA) to detect temperature rises in a substrate induced by pulsed radiation. A pulsed laser is used to produce transient heating of an object. The temperature rise, due to the optical absorption of the pulsed laser light, creates an increase in infrared emission which is measured by the IR-FPA. Although the application of IRT to image subsurface cracks due to metal fatigue is a topic of great interest in the aircraft industry, the application to image subsurface chromophores in biological materials is novel. We present an image recovery method based on a constrained conjugate gradient algorithm that has obtained the first ever high quality images of port wine blood vessels.

  17. Automated characterization of blood vessels as arteries and veins in retinal images.

    Science.gov (United States)

    Mirsharif, Qazaleh; Tajeripour, Farshad; Pourreza, Hamidreza

    2013-01-01

    In recent years researchers have found that alternations in arterial or venular tree of the retinal vasculature are associated with several public health problems such as diabetic retinopathy which is also the leading cause of blindness in the world. A prerequisite for automated assessment of subtle changes in arteries and veins, is to accurately separate those vessels from each other. This is a difficult task due to high similarity between arteries and veins in addition to variation of color and non-uniform illumination inter and intra retinal images. In this paper a novel structural and automated method is presented for artery/vein classification of blood vessels in retinal images. The proposed method consists of three main steps. In the first step, several image enhancement techniques are employed to improve the images. Then a specific feature extraction process is applied to separate major arteries from veins. Indeed, vessels are divided to smaller segments and feature extraction and vessel classification are applied to each small vessel segment instead of each vessel point. Finally, a post processing step is added to improve the results obtained from the previous step using structural characteristics of the retinal vascular network. In the last stage, vessel features at intersection and bifurcation points are processed for detection of arterial and venular sub trees. Ultimately vessel labels are revised by publishing the dominant label through each identified connected tree of arteries or veins. Evaluation of the proposed approach against two different datasets of retinal images including DRIVE database demonstrates the good performance and robustness of the method. The proposed method may be used for determination of arteriolar to venular diameter ratio in retinal images. Also the proposed method potentially allows for further investigation of labels of thinner arteries and veins which might be found by tracing them back to the major vessels.

  18. An upgraded camera-based imaging system for mapping venous blood oxygenation in human skin tissue

    Science.gov (United States)

    Li, Jun; Zhang, Xiao; Qiu, Lina; Leotta, Daniel F.

    2016-07-01

    A camera-based imaging system was previously developed for mapping venous blood oxygenation in human skin. However, several limitations were realized in later applications, which could lead to either significant bias in the estimated oxygen saturation value or poor spatial resolution in the map of the oxygen saturation. To overcome these issues, an upgraded system was developed using improved modeling and image processing algorithms. In the modeling, Monte Carlo (MC) simulation was used to verify the effectiveness of the ratio-to-ratio method for semi-infinite and two-layer skin models, and then the relationship between the venous oxygen saturation and the ratio-to-ratio was determined. The improved image processing algorithms included surface curvature correction and motion compensation. The curvature correction is necessary when the imaged skin surface is uneven. The motion compensation is critical for the imaging system because surface motion is inevitable when the venous volume alteration is induced by cuff inflation. In addition to the modeling and image processing algorithms in the upgraded system, a ring light guide was used to achieve perpendicular and uniform incidence of light. Cross-polarization detection was also adopted to suppress surface specular reflection. The upgraded system was applied to mapping of venous oxygen saturation in the palm, opisthenar and forearm of human subjects. The spatial resolution of the oxygenation map achieved is much better than that of the original system. In addition, the mean values of the venous oxygen saturation for the three locations were verified with a commercial near-infrared spectroscopy system and were consistent with previously published data.

  19. Validation of an axial flow blood pump: computational fluid dynamics results using particle image velocimetry.

    Science.gov (United States)

    Su, Boyang; Chua, Leok Poh; Wang, Xikun

    2012-04-01

    A magnetically suspended axial flow blood pump is studied experimentally in this article. The pump casing enclosed a three-blade straightener, a two-blade impeller shrouded by a permanent magnet-embedded cylinder, and a three-blade diffuser. The internal flow fields were simulated earlier using computational fluid dynamics (CFD), and the pump characteristic curves were determined. The simulation results showed that the internal flow field was basically streamlined, except the diffuser region. Particle image velocimetry (PIV) measurement of the 1:1 pump model was conducted to validate the CFD result. In order to ensure the optical access, an acrylic prototype was fabricated with the impeller driven by a servomotor instead, as the magnet is opaque. In addition to the transparent model, the blood analog fluid with the refractive index close to that of acrylic was used to avoid refraction. According to the CFD results, the axial flow blood pump could generate adequate pressure head at the rotating speed of 9500rpm and flow rate of 5L/min, and the same flow condition was applied during the PIV measurement. Through the comparisons, it was found that the experimental results were close to those obtained by CFD and had thus validated the CFD model, which could complement the limitation of the measurement in assessing the more detailed flow fields of the axial flow pump.

  20. Spectral-spatial fusion model for robust blood pulse waveform extraction in photoplethysmographic imaging.

    Science.gov (United States)

    Amelard, Robert; Clausi, David A; Wong, Alexander

    2016-12-01

    Photoplethysmographic imaging is an optical solution for non-contact cardiovascular monitoring from a distance. This camera-based technology enables physiological monitoring in situations where contact-based devices may be problematic or infeasible, such as ambulatory, sleep, and multi-individual monitoring. However, automatically extracting the blood pulse waveform signal is challenging due to the unknown mixture of relevant (pulsatile) and irrelevant pixels in the scene. Here, we propose a signal fusion framework, FusionPPG, for extracting a blood pulse waveform signal with strong temporal fidelity from a scene without requiring anatomical priors. The extraction problem is posed as a Bayesian least squares fusion problem, and solved using a novel probabilistic pulsatility model that incorporates both physiologically derived spectral and spatial waveform priors to identify pulsatility characteristics in the scene. Evaluation was performed on a 24-participant sample with various ages (9-60 years) and body compositions (fat% 30.0 ± 7.9, muscle% 40.4 ± 5.3, BMI 25.5 ± 5.2 kg·m(-2)). Experimental results show stronger matching to the ground-truth blood pulse waveform signal compared to the FaceMeanPPG (p waveform via temporal analysis.

  1. A blood-mimicking fluid for particle image velocimetry with silicone vascular models

    Science.gov (United States)

    Yousif, Majid Y.; Holdsworth, David W.; Poepping, Tamie L.

    2011-03-01

    For accurate particle image velocimetry measurements in hemodynamics studies, it is important to use a fluid with a refractive index ( n) matching that of the vascular models (phantoms) and ideally a dynamic viscosity matching human blood. In this work, a blood-mimicking fluid (BMF) composed of water, glycerol, and sodium iodide was formulated for a range of refractive indices to match most common silicone elastomers ( n = 1.40-1.43) and with corresponding dynamic viscosity within the average cited range of healthy human blood (4.4 ± 0.5 cP). Both refractive index and viscosity were attained at room temperature (22.2 ± 0.2°C), which eliminates the need for a temperature-control system. An optimally matched BMF, suitable for use in a vascular phantom ( n = 1.4140 ± 0.0008, Sylgard 184), was demonstrated with composition (by weight) of 47.38% water, 36.94% glycerol (44:56 glycerol-water ratio), and 15.68% sodium iodide salt, resulting in a dynamic viscosity of 4 .31 ± 0 .03 cP.

  2. Blood pressure and fasting lipid changes after 24 weeks’ treatment with vildagliptin: a pooled analysis in >2,000 previously drug-naïve patients with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Evans M

    2016-08-01

    Full Text Available Marc Evans,1 Anja Schweizer,2 James E Foley3 1Diabetes Resource Centre, Llandough Hospital, Cardiff, UK; 2Medical Affairs Cardio Metabolic, Novartis Pharma AG, Basel, Switzerland; 3Medical Affairs Cardio-Metabolic, Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA Introduction: We have previously shown modest weight loss with vildagliptin treatment. Since body weight balance is associated with changes in blood pressure (BP and fasting lipids, we have assessed these parameters following vildagliptin treatment. Methods: Data were pooled from all double-blind, randomized, controlled, vildagliptin monotherapy trials on previously drug-naïve patients with type 2 diabetes mellitus who received vildagliptin 50 mg once daily (qd or twice daily (bid; n=2,108 and wherein BP and fasting lipid data were obtained. Results: Data from patients receiving vildagliptin 50 mg qd or bid showed reductions from baseline to week 24 in systolic BP (from 132.5±0.32 to 129.8±0.34 mmHg; P<0.0001, diastolic BP (from 81.2±0.18 to 79.6±0.19 mmHg; P<0.0001, fasting triglycerides (from 2.00±0.02 to 1.80±0.02 mmol/L; P<0.0001, very low density lipoprotein cholesterol (from 0.90±0.01 to 0.83±0.01 mmol/L; P<0.0001, and low density lipoprotein cholesterol (from 3.17±0.02 to 3.04±0.02 mmol/L; P<0.0001, whereas high density lipoprotein cholesterol increased (from 1.19±0.01 to 1.22±0.01 mmol/L; P<0.001. Weight decreased by 0.48±0.08 kg (P<0.001. Conclusion: This large pooled analysis demonstrated that vildagliptin shows a significant reduction in BP and a favorable fasting lipid profile that are associated with modest weight loss. Keywords: TG, HDL, LDL, body weight DPP-4 inhibitor, GLP-1 

  3. Perfusion-weighted imaging and dynamic 4D angiograms for the estimation of collateral blood flow in lacunar infarction.

    Science.gov (United States)

    Förster, Alex; Mürle, Bettina; Böhme, Johannes; Al-Zghloul, Mansour; Kerl, Hans U; Wenz, Holger; Groden, Christoph

    2016-10-01

    Although lacunar infarction accounts for approximately 25% of ischemic strokes, collateral blood flow through anastomoses is not well evaluated in lacunar infarction. In 111 lacunar infarction patients, we analyzed diffusion-weighted images, perfusion-weighted images, and blood flow on dynamic four-dimensional angiograms generated by use of Signal Processing In NMR-Software. Blood flow was classified as absent (type 1), from periphery to center (type 2), from center to periphery (type 3), and combination of type 2 and 3 (type 4). On diffusion-weighted images, lacunar infarction was found in the basal ganglia (11.7%), internal capsule (24.3%), corona radiata (30.6%), thalamus (24.3%), and brainstem (9.0%). In 58 (52.2%) patients, perfusion-weighted image showed a circumscribed hypoperfusion, in one (0.9%) a circumscribed hyperperfusion, whereas the remainder was normal. In 36 (62.1%) patients, a larger perfusion deficit (>7 mm) was observed. In these, blood flow was classified type 1 in four (11.1%), 2 in 17 (47.2%), 3 in 9 (25.0%), and 4 in six (16.7%) patients. Patients with lacunar infarction in the posterior circulation more often demonstrated blood flow type 2 and less often type 3 (p = 0.01). Detailed examination and graduation of blood flow in lacunar infarction by use of dynamic four-dimensional angiograms is feasible and may serve for a better characterization of this stroke subtype.

  4. Velocity field measurements of valvular blood flow in a human superficial vein using high-frequency ultrasound speckle image velocimetry.

    Science.gov (United States)

    Nam, Kweon-Ho; Yeom, Eunseop; Ha, Hojin; Lee, Sang-Joon

    2012-01-01

    This study aims to investigate the blood flow around the perivalvular area in a human superficial vein using high-frequency ultrasound (HFUS) speckle image velocimetry. HFUS B-mode images were captured from the superficial veins of human lower extremity with a 35-MHz transducer. To measure the instantaneous velocity fields of blood flow, a cross-correlation particle image velocimetry (PIV) algorithm was applied to two B-mode images that were captured consecutively. The echo speckles of red blood cells (RBCs) were used as flow tracers. In the vicinity of the venous valve, the opening and closing motions of valve cusps were simultaneously visualized with the phasic variation of velocity fields. Large-scale vortices were observed behind the sinus pockets while the main bloodstream was directed proximally. This measurement technique combining PIV algorithm and HFUS B-mode imaging was found to be unique and useful for investigating the hemodynamic characteristics of blood flow in the perivalvular area and for diagnosing venous insufficiency and valve abnormality in superficial blood vessels.

  5. Color functional images of the cerebral blood flow. [/sup 133/Xe

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, H.; Iio, M.; Iisaka, J.; Chiba, K.; Yamada, H.; Matsui, K.; Hoshi, Y.; Fuse, M.

    1976-11-01

    Functional gamma imaging, in color, was established for regional cerebral blood flow (rCBF) using /sup 133/Xe. During 10 min after intracarotid injection of /sup 133/Xe in saline, 60 picture frames of the /sup 133/Xe clearance curve for the entire hemisphere were obtained. After nine-point smoothing, the rCBF for each of the 4,096 picture elements was calculated by two methods: the half-time method and the height-over-area method. Both the /sup 133/Xe clearance half-times and the calculated CBF values were displayed, using 13 steps of color, as functional CBF images of the brain. Images of peak count and total count were also displayed on the same frame of the color television. Forty-six studies, performed on 37 patients with various cerebral disorders, were divided into two types: diffuse and focal. In the diffuse type, a decrease in CBF was noted in cases of normal-pressure hydrocephalus; successful ventriculoperitoneal shunt operations were followed by recovery of CBF. Occlusion of the middle cerebral artery showed up as a wedge-shaped area of decreased CBF, even when the conventional brain scan looked normal. Increased perfusion to a tumor was frequently associated with decreased CBF in the rest of the lateral hemisphere; such a decrease could be improved by surgical removal of the tumor.

  6. Non-contrast enhanced MR venography using 3D fresh blood imaging (FBI). Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Kenichi; Nitatori, Toshiaki; Inaoka, Sayuki; Takahara, Taro; Hachiya, Junichi [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    2001-10-01

    This study examined the efficacy of 3D-fresh blood imaging (FBI) in patients with venous disease in the iliac region to lower extremity. Fourteen patients with venous disease were examined [8 deep venous thrombosis (DVT) and 6 varix] by 3D-FBI and 2D-TOF MRA. ALL FBI images and 2D-TOF images were evaluated in terms of visualization of the disease and compared with conventional X-ray venography (CV). The total scan time of 3D-FBI ranged from 3 min 24 sec to 4 min 52 sec. 3D-FBI was positive in all 23 anatomical levels in which DVT was diagnosed by CV (100% sensitivity) as well as 2D-TOF. The delineation of collateral veins was superior or equal to that of 2D-TOF. 3D-FBI allowed depiction of varices in five of six cases; however, in one case, the evaluation was limited because the separation of arteries from veins was difficult. The 3D-FBI technique, which allows iliac to peripheral MR venography without contrast medium within a short acquisition time, is considered clinically useful. (author)

  7. Blood group typing based on recording the elastic scattering of laser radiation using the method of digital imaging

    Energy Technology Data Exchange (ETDEWEB)

    Dolmashkin, A A; Dubrovskii, V A; Zabenkov, I V [V.I.Razumovsky Saratov State Medical University, Saratov (Russian Federation)

    2012-05-31

    The possibility is demonstrated to determine the human blood group by recording the scattering of laser radiation with the help of the digital imaging method. It is experimentally shown that the action of a standing ultrasound wave leads to acceleration of the agglutination reaction of red blood cells, to formation of larger immune complexes of red blood cells, and, as a consequence, to acceleration of their sedimentation. In the absence of agglutination of red blood cells the ultrasound does not enhance the relevant processes. This difference in the results of ultrasound action on the mixture of blood and serum allows a method of blood typing to be offered. Theoretical modelling of the technique of the practical blood typing, carried out on the basis of the elastic light scattering theory, agrees well with the experimental results, which made it possible to plan further improvement of the proposed method. The studies of specific features of sedimentation of red blood cells and their immune complexes were aimed at the optimisation of the sample preparation, i.e., at the search for such experimental conditions that provide the maximal resolution of the method and the device for registering the reaction of red blood cells agglutination. The results of the study may be used in designing the instrumentation for blood group assessment in humans.

  8. Quantitative assessment of brain perfusion with magnetic resonance imaging

    NARCIS (Netherlands)

    Bleeker, Egbert Jan Willem

    2011-01-01

    This thesis focuses on assessing blood supply to brain tissue using MRI. For Dynamic Susceptibility Contrast-MRI a series of images is acquired during the passage of a bolus contrast agent through the brain up to the point that the contrast agent is equally mixed within the total blood pool. The tis

  9. PDA: Pooled DNA analyzer

    Directory of Open Access Journals (Sweden)

    Lin Chin-Yu

    2006-04-01

    Full Text Available Abstract Background Association mapping using abundant single nucleotide polymorphisms is a powerful tool for identifying disease susceptibility genes for complex traits and exploring possible genetic diversity. Genotyping large numbers of SNPs individually is performed routinely but is cost prohibitive for large-scale genetic studies. DNA pooling is a reliable and cost-saving alternative genotyping method. However, no software has been developed for complete pooled-DNA analyses, including data standardization, allele frequency estimation, and single/multipoint DNA pooling association tests. This motivated the development of the software, 'PDA' (Pooled DNA Analyzer, to analyze pooled DNA data. Results We develop the software, PDA, for the analysis of pooled-DNA data. PDA is originally implemented with the MATLAB® language, but it can also be executed on a Windows system without installing the MATLAB®. PDA provides estimates of the coefficient of preferential amplification and allele frequency. PDA considers an extended single-point association test, which can compare allele frequencies between two DNA pools constructed under different experimental conditions. Moreover, PDA also provides novel chromosome-wide multipoint association tests based on p-value combinations and a sliding-window concept. This new multipoint testing procedure overcomes a computational bottleneck of conventional haplotype-oriented multipoint methods in DNA pooling analyses and can handle data sets having a large pool size and/or large numbers of polymorphic markers. All of the PDA functions are illustrated in the four bona fide examples. Conclusion PDA is simple to operate and does not require that users have a strong statistical background. The software is available at http://www.ibms.sinica.edu.tw/%7Ecsjfann/first%20flow/pda.htm.

  10. Advantage in Bright-blood and Black-blood Magnetic Resonance Imaging with High-resolution for Analysis of Carotid Atherosclerotic Plaques

    Directory of Open Access Journals (Sweden)

    Mei Li

    2015-01-01

    Full Text Available Background: About 50% of the cerebral ischemia events are induced by intracranial and extracranial atherosclerosis. This study aimed to evaluate the feasibility and accuracy for displaying atherosclerotic plaques in carotid arteries and analyzing their ingredients by using high-resolution new magnetic resonance imaging (MRI techniques. Methods: Totally, 49 patients suspected of extracranial carotid artery stenosis were subjected to cranial MRI scan and magnetic resonance angiography (MRA examination on carotid arteries, and high-resolution bright-blood and black-blood MRI analysis was carried out within 1 week. Digital subtraction angiography (DSA examination was carried out for 16 patients within 1 month. Results: Totally, 103 plaques were detected in the 49 patients, which were characterized by localized or diffusive thickening of the vessel wall, with the intrusion of crescent-shaped abnormal signal into lumens. Fibrous cap was displayed as isointensity in T1-weighted image (T1WI and hyperintensities in proton density weighted image (PDWI and T2-weighted image (T2WI, lipid core was displayed as isointensity or slight hyperintensities in T1WI, isointensity, hyperintensities or hypointensity in PDWI, and hypointensity in T2WI. Calcification in plaques was detected in 11 patients. Eight patients were detected with irregular plaque surface or ulcerative plaques, which were characterized by irregular intravascular space surface in the black-blood sequences, black hypointensity band was not detected in three-dimensional time-of-flight, or the hypointensity band was not continuous, and intrusion of hyperintensities into plaques can be detected. Bright-blood and black-blood techniques were highly correlated with the diagnosis of contrast-enhanced MRA in angiostenosis degree, Rs = 0.97, P < 0.001. In comparison to DSA, the sensitivity, specificity, and accuracy of MRI diagnosis of stenosis for ≥50% were 88.9%, 100%, and 97.9%, respectively

  11. Eigenspectra optoacoustic tomography achieves quantitative blood oxygenation imaging deep in tissues

    CERN Document Server

    Tzoumas, Stratis; Olefir, Ivan; Stangl, Stefan; Symvoulidis, Panagiotis; Glasl, Sarah; Bayer, Christine; Multhoff, Gabriele; Ntziachristos, Vasilis

    2015-01-01

    Light propagating in tissue attains a spectrum that varies with location due to wavelength-dependent fluence attenuation by tissue optical properties, an effect that causes spectral corruption. Predictions of the spectral variations of light fluence in tissue are challenging since the spatial distribution of optical properties in tissue cannot be resolved in high resolution or with high accuracy by current methods. Spectral corruption has fundamentally limited the quantification accuracy of optical and optoacoustic methods and impeded the long sought-after goal of imaging blood oxygen saturation (sO2) deep in tissues; a critical but still unattainable target for the assessment of oxygenation in physiological processes and disease. We discover a new principle underlying light fluence in tissues, which describes the wavelength dependence of light fluence as an affine function of a few reference base spectra, independently of the specific distribution of tissue optical properties. This finding enables the introd...

  12. Vitamin D Pooling Project

    Science.gov (United States)

    The Vitamin D Pooling Project of Rarer Cancers brought together investigators from 10 cohorts to conduct a large prospective epidemiologic study of the association between vitamin D status and seven rarer cancers.

  13. Trans-illuminated laser speckle imaging of collateral artery blood flow in ischemic mouse hindlimb.

    Science.gov (United States)

    Meisner, Joshua K; Niu, Jacqueline; Sumer, Suna; Price, Richard J

    2013-09-01

    The mouse ischemic hindlimb model is used widely for studying collateral artery growth (i.e., arteriogenesis) in response to increased shear stress. Nonetheless, precise measurements of regional shear stress changes along individual collateral arteries are lacking. Our goal is to develop and verify trans-illumination laser speckle flowmetry (LSF) for this purpose. Studies of defibrinated bovine blood flow through tubes embedded in tissue-mimicking phantoms indicate that trans-illumination LSF better maintains sensitivity with an increasing tissue depth when compared to epi-illumination, with an ∼50% reduction in the exponential decay of the speckle velocity signal. Applying trans-illuminated LSF to the gracilis muscle collateral artery network in vivo yields both improved sensitivity and reduced noise when compared to epi-illumination. Trans-illuminated LSF images reveal regional differences in collateral artery blood velocity after femoral artery ligation and are used to measure an ∼2-fold increase in the shear stress at the entrance regions to the muscle. We believe these represent the first direct measurements of regional shear stress changes in individual mouse collateral arteries. The ability to capture deeper vascular signals using a trans-illumination configuration for LSF may expand the current applications for LSF, which could have bearing on determining how shear stress magnitude and direction regulate arteriogenesis.

  14. A quantitative MRI method for imaging blood-brain barrier leakage in experimental traumatic brain injury.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Blood-brain barrier (BBB disruption is common following traumatic brain injury (TBI. Dynamic contrast enhanced (DCE MRI can longitudinally measure the transport coefficient Ktrans which reflects BBB permeability. Ktrans measurements however are not widely used in TBI research because it is generally considered to be noisy and possesses low spatial resolution. We improved spatiotemporal resolution and signal sensitivity of Ktrans MRI in rats by using a high-sensitivity surface transceiver coil. To overcome the signal drop off profile of the surface coil, a pre-scan module was used to map the flip angle (B1 field and magnetization (M0 distributions. A series of T1-weighted gradient echo images were acquired and fitted to the extended Kety model with reversible or irreversible leakage, and the best model was selected using F-statistics. We applied this method to study the rat brain one hour following controlled cortical impact (mild to moderate TBI, and observed clear depiction of the BBB damage around the impact regions, which matched that outlined by Evans Blue extravasation. Unlike the relatively uniform T2 contrast showing cerebral edema, Ktrans shows a pronounced heterogeneous spatial profile in and around the impact regions, displaying a nonlinear relationship with T2. This improved Ktrans MRI method is also compatible with the use of high-sensitivity surface coil and the high-contrast two-coil arterial spin-labeling method for cerebral blood flow measurement, enabling more comprehensive investigation of the pathophysiology in TBI.

  15. Transport of nanoparticles through the blood-brain barrier for imaging and therapeutic applications

    Science.gov (United States)

    Shilo, Malka; Motiei, Menachem; Hana, Panet; Popovtzer, Rachela

    2014-01-01

    A critical problem in the treatment of neurodegenerative disorders and diseases, such as Alzheimer's and Parkinson's, is the incapability to overcome the restrictive mechanism of the blood-brain barrier (BBB) and to deliver important therapeutic agents to the brain. During the last decade, nanoparticles have gained attention as promising drug delivery agents that can transport across the BBB and increase the uptake of appropriate drugs in the brain. In this study we have developed insulin-targeted gold nanoparticles (INS-GNPs) and investigated quantitatively the amount of INS-GNPs that cross the BBB by the receptor-mediated endocytosis process. For this purpose, INS-GNPs and control GNPs were injected into the tail vein of male BALB/c mice. Major organs were then extracted and a blood sample was taken from the mice, and thereafter analyzed for gold content by flame atomic absorption spectroscopy. Results show that two hours post-intravenous injection, the amount of INS-GNPs found in mouse brains is over 5 times greater than that of the control, untargeted GNPs. Results of further experimentation on a rat model show that INS-GNPs can also serve as CT contrast agents to highlight specific brain regions in which they accumulate. Due to the fact that they can overcome the restrictive mechanism of the BBB, this approach could be a potentially valuable tool, helping to confront the great challenge of delivering important imaging and therapeutic agents to the brain for detection and treatment of neurodegenerative disorders and diseases.

  16. Use of myocardial imaging in the evaluation of patients with cardiovascular disease

    Energy Technology Data Exchange (ETDEWEB)

    Pitt, B.; Strauss, H.W.; Trhall, J.H.

    1980-01-01

    The role of radioisotope tracer techniques in the evaluation of patients with congenital heart disease, valvular heart disease, suspected myocardial infarction, ischemia or suspected ventricular dysfunction is reviewed. Thallium-201 myocardial imaging and exercise blood pool imaging and Technetium-88m pyrophosphate imaging of myocardial infarction are most commonly used.

  17. Advances in PET imaging of P-glycoprotein function at the blood-brain barrier.

    Science.gov (United States)

    Syvänen, Stina; Eriksson, Jonas

    2013-02-20

    Efflux transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) restricts substrate compounds from entering the brain and may thus contribute to pharmacoresistance observed in patient groups with refractory epilepsy and HIV. Altered P-gp function has also been implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Positron emission tomography (PET), a molecular imaging modality, has become a promising method to study the role of P-gp at the BBB. The first PET study of P-gp function was conducted in 1998, and during the past 15 years two main categories of P-gp PET tracers have been investigated: tracers that are substrates of P-gp efflux and tracers that are inhibitors of P-gp function. PET, as a noninvasive imaging technique, allows translational research. Examples of this are preclinical investigations of P-gp function before and after administering P-gp modulating drugs, investigations in various animal and disease models, and clinical investigations regarding disease and aging. The objective of the present review is to give an overview of available PET radiotracers for studies of P-gp and to discuss how such studies can be designed. Further, the review summarizes results from PET studies of P-gp function in different central nervous system disorders.

  18. Quantitative measurements of cerebral blood flow in volume imaging PET scanners

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.J.; Shao, L.; Freifelder, R.; Karp, J.S.; Ragland, J.D. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-08-01

    Quantitative measurements of Cerebral Blood Flow (CBF) are performed in a volume imaging PET Scanner by means of moderate activity infusions. In equilibrium infusions, activations are measured by scanning over 10 minutes with 16 minute activations. Typical measured whole brain CBF values are 37{+-}8 ml/min/100g, close to the value of 42 ml/min/100g reported by other groups using this method. For ramped infusions, scanning over 4 minutes with 5 minute activations results in whole brain CBFs of 49 {+-} 9 ml/min/100g, close to the Kety and Schmidt value of 50 ml/min/100g. Both equilibrium and ramped infusion methods have been used to study face and word memory in human subjects. Both methods were able to detect significant activations in regions implicated in human memory. The authors conclude that precise quantitation of regional CBF is achieved using both methods, and that ramped infusions also provide accurate measures of CBF. In addition a simplified protocol for ramped infusion studies has been developed. In this method the whole brain tissue time activity curve generated from dynamic scanning is replaced by an appropriately scaled camera coincidence countrate curve. The resulting whole brain CBF values are only 7% different from the dynamic scan and fit results. Regional CBFs (rCBF) may then be generated from the summed image (4.25 minutes) using a count density vs flow lookup table.

  19. Correlation analysis of high precision blood flow imaging in secondary parathyroid function in maintenance hemodialysis patients

    Institute of Scientific and Technical Information of China (English)

    Wen-Ze Du; Le Chen; Xiao-Yun Wu

    2016-01-01

    Objective:To investigate the value of high precision blood flow imaging (Fine-Flow) in secondary parathyroid function (SHPT) in patients with maintenance hemodialysis (MHD). Methods: A total of 95 MHD patients with SHPT in our hospital from January 2015 to June 2016 were selected as the research object. According to the Fine-Flow examination of parathyroid gland, 73 cases were divided into display group, 22 cases were not shown; Display group according to the hyperplasia of parathyroid diameter were divided into 1.5 cm group of 17 cases; display group according to the blood flow into the rich group of 41 cases, not rich group of 32 cases; according to whether calcification were divided into calcification group of 43 cases, non calcified group of 30 cases. CDFI was used for the anterior region of neck transverse and longitudinal scanning, check the thyroid and around the dorsal lobes.The size, echo, lesion number and blood flow were measured, parathyroid hormone (PTH), serum calcium (Ca), phosphorus (P), and calculate the Ca and P product (Ca×P) were measured.Results: PTH and Ca of the display group were significantly higher than that of the non display group, and differences in P and Ca×P were not statistically significant; Parathyroid diameter >1.5 cm PTH levels were significantly higher than the other three groups, diameter 1-1.5 cm group and >1.5 cm group Ca, diameter Ca×P was higher than that in group <5 cm and 0.5-1.0 cm group, difference in P of four groups was not statistical significant; group PTH, P, abundant blood flow Ca×P were not significantly higher than the rich group, difference in P of two groups was no statistical significance; group Ca was significantly higher than that of calcification calcification group, differences in PTH, P, Ca×P of the two groups were not statistically significant.Conclusions:MHD patients with SHPT, parathyroid Fine-Flow display rate is high, and has the characteristic performance. Its operation is simple, non

  20. Dark blood versus bright blood T2* acquisition in cardiovascular magnetic resonance (CMR) for thalassaemia major (TM) patients: Evaluation of feasibility, reproducibility and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Liguori, Carlo, E-mail: c.liguori@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Di Giampietro, Ilenia; Pitocco, Francesca; De Vivo, Aldo Eros [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Schena, Emiliano [Unit of Measurements and Biomedical Instrumentation, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Mortato, Luca [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Pirro, Federica [Department of Biomaging and Radiological Sciences, Catholic University of Sacred Herart, Largo A. Gemelli 1, 00135 Rome (Italy); Cianciulli, Paolo [Thalassemia Unit, Ospedale Sant Eugenio, Piazzale dell’Umanesimo 10, 00143 Rome (Italy); Zobel, Bruno Beomonte [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy)

    2014-01-15

    Objectives: To compare the effectiveness of dark blood (DB) versus bright blood (BB) sequences. To assess the intra and inter-observer variability and inter-study reproducibility between BB versus DB. To evaluate image quality level in the two sequences. Methods: In a setting of 138 patients we performed CMR using cardiac gated Gradient-multiecho single breath-hold BB and DB sequences in the middle ventricular septum. Each acquisition was repeated during the same exam. Truncation method was used to account for background noise. Image quality (IQ) was assessed using a 5 point grading scale and image analysis was conducted by 2 experienced observers. Results: Compared with the conventional BB acquisition, the coefficient of correlation and significance of the DB technique was superior for intra-observer reproducibility (p < 0.001), inter-observer reproducibility (p < 0.001) and inter-study reproducibility (p < 0.001). The variability is also lower for DB sequences for T2* values <14 ms. Assessment of artifacts showed a superior score for DB versus BB scans (4 versus 3, p < 0.001). Conclusions: Improvement in terms of inter observer and inter study variability using DB sequences was obtained. The greatest disparity between them was seen in inter-study reproducibility and higher IQ in DB was seen. Study demonstrates better performance of DB imaging compared to BB in presence of comparable effectiveness.

  1. Flow measurements in a blood-perfused collagen vessel using x-ray micro-particle image velocimetry.

    Science.gov (United States)

    Antoine, Elizabeth; Buchanan, Cara; Fezzaa, Kamel; Lee, Wah-Keat; Rylander, M Nichole; Vlachos, Pavlos

    2013-01-01

    Blood-perfused tissue models are joining the emerging field of tumor engineering because they provide new avenues for modulation of the tumor microenvironment and preclinical evaluation of the therapeutic potential of new treatments. The characterization of fluid flow parameters in such in-vitro perfused tissue models is a critical step towards better understanding and manipulating the tumor microenvironment. However, traditional optical flow measurement methods are inapplicable because of the opacity of blood and the thickness of the tissue sample. In order to overcome the limitations of optical method we demonstrate the feasibility of using phase-contrast x-ray imaging to perform microscale particle image velocimetry (PIV) measurements of flow in blood perfused hydrated tissue-representative microvessels. However, phase contrast x-ray images significantly depart from the traditional PIV image paradigm, as they have high intensity background, very low signal-to-noise ratio, and volume integration effects. Hence, in order to achieve accurate measurements special attention must be paid to the image processing and PIV cross-correlation methodologies. Therefore we develop and demonstrate a methodology that incorporates image preprocessing as well as advanced PIV cross-correlation methods to result in measured velocities within experimental uncertainty.

  2. Flow measurements in a blood-perfused collagen vessel using x-ray micro-particle image velocimetry.

    Directory of Open Access Journals (Sweden)

    Elizabeth Antoine

    Full Text Available Blood-perfused tissue models are joining the emerging field of tumor engineering because they provide new avenues for modulation of the tumor microenvironment and preclinical evaluation of the therapeutic potential of new treatments. The characterization of fluid flow parameters in such in-vitro perfused tissue models is a critical step towards better understanding and manipulating the tumor microenvironment. However, traditional optical flow measurement methods are inapplicable because of the opacity of blood and the thickness of the tissue sample. In order to overcome the limitations of optical method we demonstrate the feasibility of using phase-contrast x-ray imaging to perform microscale particle image velocimetry (PIV measurements of flow in blood perfused hydrated tissue-representative microvessels. However, phase contrast x-ray images significantly depart from the traditional PIV image paradigm, as they have high intensity background, very low signal-to-noise ratio, and volume integration effects. Hence, in order to achieve accurate measurements special attention must be paid to the image processing and PIV cross-correlation methodologies. Therefore we develop and demonstrate a methodology that incorporates image preprocessing as well as advanced PIV cross-correlation methods to result in measured velocities within experimental uncertainty.

  3. The non-contact detection and identification of blood stained fingerprints using visible wavelength reflectance hyperspectral imaging: Part 1.

    Science.gov (United States)

    Cadd, Samuel; Li, Bo; Beveridge, Peter; O'Hare, William T; Campbell, Andrew; Islam, Meez

    2016-05-01

    Blood is one of the most commonly encountered types of biological evidence found at scenes of violent crime and one of the most commonly observed fingerprint contaminants. Current visualisation methods rely on presumptive tests or chemical enhancement methods. Although these can successfully visualise ridge detail, they are destructive, do not confirm the presence of blood and can have a negative impact on DNA sampling. A novel application of visible wavelength reflectance hyperspectral imaging (HSI) has been used for the detection and positive identification of blood stained fingerprints in a non-contact and non-destructive manner on white ceramic tiles. The identification of blood was based on the unique visible absorption spectrum of haemoglobin between 400 and 500 nm. HSI has been used to successfully visualise ridge detail in blood stained fingerprints to the ninth depletion. Ridge detail was still detectable with diluted blood to 20-fold dilutions. Latent blood stains were detectable to 15,000-fold dilutions. Ridge detail was detectable for fingerprints up to 6 months old. HSI was also able to conclusively distinguish blood stained fingerprints from fingerprints in six paints and eleven other red/brown media with zero false positives.

  4. Absolute Versus Relative Myocardial Blood Flow by Dynamic CT Myocardial Perfusion Imaging in Patients With Anatomic Coronary Artery Disease

    NARCIS (Netherlands)

    Wichmann, Julian L.; Meinel, Felix G.; Schoepf, U. Joseph; Lo, Gladys G.; Choe, Yeon Hyeon; Wang, Yining; Vliegenthart, Rozemarijn; Varga-Szemes, Akos; Muscogiuri, Giuseppe; Cannao, Paola M.; De Cecco, Carlo N.

    2015-01-01

    OBJECTIVE. The purpose of this study was to evaluate differences in the diagnostic accuracy of absolute and relative territorial myocardial blood flow (MBF) derived from stress dynamic CT myocardial perfusion imaging (MPI) for the detection of significant coronary artery stenosis. MATERIALS AND METH

  5. A gel-based skin and blood flow model for a Doppler optical coherence tomography (DOCT) imaging system

    Science.gov (United States)

    Lawlor, Kate; O'Connell, Marie-Louise; Jonathan, Enock; Leahy, Martin J.

    2010-02-01

    Since its discovery in 1842 by Christian Johann Doppler, the Doppler Effect has had many applications in the scientific world. In recent years, the phenomenon has been integrated with Optical Coherence Tomography (OCT) yielding Doppler Optical Coherence Tomography (DOCT), a technique that is useful for high-resolution imaging of the skin microcirculation. However, interpretation of DOCT images is rather challenging. Thus, our study aims to aid understanding of DOCT images with respect to parameters of microcirculation components such as blood vessel size, depth and angular position. To this end, we have constructed a gel-based tissue and blood-flow model for performing DOCT studies under well controlled conditions. We present results from a pilot study using a gel-based tissue and blood flow model. Human blood was pumped through the model at various velocities from a commercial calibrated syringe pump, serving as a standard reference point for all velocity measurements. The range of velocity values was chosen to coincide with that found in the human vasculature. Simultaneous DOCT imaging at different flow rates contributed to establishing the capabilities and limitations of the DOCT system under investigation. We present preliminary results as first step to developing a robust validation protocol with which to aid future research in this area.

  6. Marginal granilocytic pool in the treatment of malignant tumors

    Energy Technology Data Exchange (ETDEWEB)

    Angelova, I.; Bakalov, M.; Zografov, D. (Meditsinska Akademiya, Sofia (Bulgaria). Nauchen Inst. po Rentgenologiya i Radiobiologiya)

    1982-01-01

    Using the adrenaline test in 57 patients with malignant tumors, the authors examined the marginal granulocytic pool at different time in the course of treatment. The state of the pool was correlated with that of the neutrophilic cells in the circulating blood and with its state before treatment was started. It is concluded that in the course of treatment the neutrophilic cell counts in the marginal cells pool undergo changes similar to those in the circulation pool. It is therefore unjustifiable to include the adrenaline test in the control examination of patients with leucopenia.

  7. In-vivo imaging of blood flow in human retinal vessels using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    1999-04-01

    Quantification of retinal blood flow may lead to a better understanding of the progression and treatment of several ocular disorders, including diabetic retinopathy, age- related macular degeneration, and glaucoma. Current techniques, such as fluorescein angiography and laser Doppler velocimetry are limited, failing to provide sufficient information to the clinician. Color Doppler optical coherence tomography (CDOCT) is a novel technique using coherent heterodyne detection for simultaneous cross- sectional imaging of tissue microstructure and blood flow. This technique is capable of high spatial and velocity resolution imaging in highly scattering media. We implemented CDOCT for retinal blood flow mapping in human subjects. No dilation of the pupil was necessary. CDOCT is demonstrated for determining bidirectional flow in sub- 100micrometers diameter vessels in the retina. Additionally, we calculated Doppler broadening using the variance of depth- resolved spectra to identify regions with large velocity gradients within the Xenopus heart. This technique may be useful in quantifying local tissue perfusion in highly vascular retinal tissue.

  8. High speed versus pulsed images for micro-particle image velocimetry: a direct comparison of red blood cells versus fluorescing tracers as tracking particles.

    Science.gov (United States)

    Pitts, Katie L; Fenech, Marianne

    2013-10-01

    High speed photography in micro-particle image velocimetry (μPIV) using red blood cells as tracer particles and the use of fluorescing tracer particles (in conjunction with pulsed images) are directly compared by using both methods simultaneously. Measurements are taken on the same blood sample in the same microchip using both methods. This work directly and statistically compares the two methods of μPIV measurement in a controlled in vitro environment for the first time in literature. The pulsed method using fluorescing tracer particles is found to decrease the depth of correlation as expected, and to better represent the shape of the velocity profile. Two methods of velocity characterization are used (single and double parameter) and the pulsed images provide better shape representation in both cases.

  9. The effect of aging on aortic atherosclerotic plaque inflammation and molecular calcification: A FDG and NaF PET CT imaging study

    DEFF Research Database (Denmark)

    Blomberg, Björn; Thomassen, Anders; Hildebrandt, Malene;

    2013-01-01

    prospectively assessed by 18-FDG (inflammation) and Sodium 18-Fluoride (Na-18F) (calcification metabolism) PET CT imaging. Global aortic uptake of 18-FDG and Na-18F was quantified by subtracting the blood pool SUVmean from the aortic SUVmax (cSUV) [maximum SUVaorta - mean SUVblood pool]. Calculating regression...

  10. Blood perfusion values of laser speckle contrast imaging and laser Doppler flowmetry: is a direct comparison possible?

    Science.gov (United States)

    Binzoni, Tiziano; Humeau-Heurtier, Anne; Abraham, Pierre; Mahe, Guillaume

    2013-05-01

    Laser Doppler flowmetry (LDF) and laser speckle contrast imaging (LSCI) allow the monitoring of microvascular blood perfusion. The relationship between the measurements obtained by these two techniques remains unclear. In the present contribution, we demonstrate, experimentally and theoretically, that skin blood flow measurements obtained by LDF and LSCI techniques cannot be compared directly even after "classical" normalization procedure. This technical problem is generated by the nonlinear relationship existing between LDF and LSCI flow data. The experiments have been performed on five healthy voluntary subjects (forearm) by using repeated ischemia/reperfusion cycles to induce the necessary skin blood flow changes. LDF and LSCI data were simultaneously acquired on the same region of interest. Considering the importance of this problem from the clinical point of view, it is concluded that the definition of new corrected algorithms for LSCI is probably a mandatory step that must be taken into account if LDF and LSCI blood flow have to be compared.

  11. High resolution carotid black-blood 3T MR with parallel imaging and dedicated 4-channel surface coils

    Directory of Open Access Journals (Sweden)

    Frey Ute

    2009-10-01

    Full Text Available Abstract Background Most of the carotid plaque MR studies have been performed using black-blood protocols at 1.5 T without parallel imaging techniques. The purpose of this study was to evaluate a multi-sequence, black-blood MR protocol using parallel imaging and a dedicated 4-channel surface coil for vessel wall imaging of the carotid arteries at 3 T. Materials and methods 14 healthy volunteers and 14 patients with intimal thickening as proven by duplex ultrasound had their carotid arteries imaged at 3 T using a multi-sequence protocol (time-of-flight MR angiography, pre-contrast T1w-, PDw- and T2w sequences in the volunteers, additional post-contrast T1w- and dynamic contrast enhanced sequences in patients. To assess intrascan reproducibility, 10 volunteers were scanned twice within 2 weeks. Results Intrascan reproducibility for quantitative measurements of lumen, wall and outer wall areas was excellent with Intraclass Correlation Coefficients >0.98 and measurement errors of 1.5%, 4.5% and 1.9%, respectively. Patients had larger wall areas than volunteers in both common carotid and internal carotid arteries and smaller lumen areas in internal carotid arteries (p Conclusion The findings of this study indicate that high resolution carotid black-blood 3 T MR with parallel imaging is a fast, reproducible and robust method to assess carotid atherosclerotic plaque in vivo and this method is ready to be used in clinical practice.

  12. In vivo bioluminescence imaging of neurogenesis - the role of the blood brain barrier in an experimental model of Parkinson's disease.

    Science.gov (United States)

    Fricke, Inga B; Schelhaas, Sonja; Zinnhardt, Bastian; Viel, Thomas; Hermann, Sven; Couillard-Després, Sébastien; Jacobs, Andreas H

    2017-02-13

    Bioluminescence imaging in transgenic mice expressing firefly luciferase in Doublecortin(+) (Dcx) neuroblasts might serve as a powerful tool to study the role of neurogenesis in models of brain injury and neurodegeneration using non-invasive, longitudinal in vivo imaging. Therefore, we aimed to use BLI in B6(Cg)-Tyrc-2J/J Dcx-Luc (Doublecortin-Luciferase, Dcx-Luc) mice to investigate its suitability to assess neurogenesis in a unilateral injection model of Parkinson's disease. We further aimed to assess the blood brain barrier leakage associated with the intranigral 6-OHDA injection to evaluate its impact on substrate delivery and bioluminescence signal intensity. Two weeks after lesion, we observed an increase in bioluminescence signal in the ipsilateral hippocampal region in both, 6-OHDA and vehicle injected Dcx-Luc mice. At the same time, no corresponding increase in Dcx(+) neuroblast numbers could be observed in the dentate gyrus of C57Bl6 mice. Blood brain barrier leakage was observed in the hippocampal region and in the degenerating substantia nigra of C57Bl6 mice in vivo using T1 weighted Magnetic Resonance Imaging with Gadovist(®) and ex vivo using Evans Blue Fluorescence Reflectance Imaging and mouse Immunoglobulin G staining. Our data suggests a BLI signal dependency on blood brain barrier permeability, underlining a major pitfall of substrate/tracer dependent imaging in invasive disease models.

  13. Imaging changes in blood volume and oxygenation in the newborn infant brain using three-dimensional optical tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hebden, Jeremy C [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London WC1E 6JA (United Kingdom); Gibson, Adam [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London WC1E 6JA (United Kingdom); Austin, Topun [Department of Paediatrics and Child Health, University College London, 5 University Street, London WC1E 6JJ (United Kingdom); Yusof, Rozarina Md [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London WC1E 6JA (United Kingdom); Everdell, Nick [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London WC1E 6JA (United Kingdom); Delpy, David T [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London WC1E 6JA (United Kingdom); Arridge, Simon R [Department of Computer Science, University College London, Gower Street, London WC1E 6BT (United Kingdom); Meek, Judith H [Department of Paediatrics and Child Health, University College London, 5 University Street, London WC1E 6JJ (United Kingdom); Wyatt, John S [Department of Paediatrics and Child Health, University College London, 5 University Street, London WC1E 6JJ (United Kingdom)

    2004-04-07

    Induced haemodynamic and blood oxygenation changes occurring within the brain of a ventilated newborn infant have been imaged in three dimensions using optical tomography. Noninvasive measurements of the flight times of transmitted light were acquired during illumination of the brain by laser pulses at wavelengths of 780 nm and 815 nm. The oxygen and carbon dioxide partial pressures were adjusted through alterations to the ventilator settings, resulting in changes to the cerebral blood volume and oxygenation. Three-dimensional images were generated using the physiologically associated differences in the measured data, obviating the need for data calibration using a separate reference measurement. The results exhibit large changes in absorption coefficient at both wavelengths. Images corresponding to differences in concentrations of oxy- and deoxyhaemoglobin are in qualitative agreement with known physiological data.

  14. Welding pool measurement using thermal array sensor

    Science.gov (United States)

    Cho, Chia-Hung; Hsieh, Yi-Chen; Chen, Hsin-Yi

    2015-08-01

    Selective laser melting (SLM) is an additive manufacturing (AM) technology that uses a high-power laser beam to melt metal powder in chamber of inert gas. The process starts by slicing the 3D CAD data as a digital information source into layers to create a 2D image of each layer. Melting pool was formed by using laser irradiation on metal powders which then solidified to consolidated structure. In a selective laser melting process, the variation of melt pool affects the yield of a printed three-dimensional product. For three dimensional parts, the border conditions of the conductive heat transport have a very large influence on the melt pool dimensions. Therefore, melting pool is an important behavior that affects the final quality of the 3D object. To meet the temperature and geometry of the melting pool for monitoring in additive manufacturing technology. In this paper, we proposed the temperature sensing system which is composed of infrared photodiode, high speed camera, band-pass filter, dichroic beam splitter and focus lens. Since the infrared photodiode and high speed camera look at the process through the 2D galvanometer scanner and f-theta lens, the temperature sensing system can be used to observe the melting pool at any time, regardless of the movement of the laser spot. In order to obtain a wide temperature detecting range, 500 °C to 2500 °C, the radiation from the melting pool to be measured is filtered into a plurality of radiation portions, and since the intensity ratio distribution of the radiation portions is calculated by using black-body radiation. The experimental result shows that the system is suitable for melting pool to measure temperature.

  15. Automatic Recognition of Acute Myelogenous Leukemia in Blood Microscopic Images Using K-means Clustering and Support Vector Machine.

    Science.gov (United States)

    Kazemi, Fatemeh; Najafabadi, Tooraj Abbasian; Araabi, Babak Nadjar

    2016-01-01

    Acute myelogenous leukemia (AML) is a subtype of acute leukemia, which is characterized by the accumulation of myeloid blasts in the bone marrow. Careful microscopic examination of stained blood smear or bone marrow aspirate is still the most significant diagnostic methodology for initial AML screening and considered as the first step toward diagnosis. It is time-consuming and due to the elusive nature of the signs and symptoms of AML; wrong diagnosis may occur by pathologists. Therefore, the need for automation of leukemia detection has arisen. In this paper, an automatic technique for identification and detection of AML and its prevalent subtypes, i.e., M2-M5 is presented. At first, microscopic images are acquired from blood smears of patients with AML and normal cases. After applying image preprocessing, color segmentation strategy is applied for segmenting white blood cells from other blood components and then discriminative features, i.e., irregularity, nucleus-cytoplasm ratio, Hausdorff dimension, shape, color, and texture features are extracted from the entire nucleus in the whole images containing multiple nuclei. Images are classified to cancerous and noncancerous images by binary support vector machine (SVM) classifier with 10-fold cross validation technique. Classifier performance is evaluated by three parameters, i.e., sensitivity, specificity, and accuracy. Cancerous images are also classified into their prevalent subtypes by multi-SVM classifier. The results show that the proposed algorithm has achieved an acceptable performance for diagnosis of AML and its common subtypes. Therefore, it can be used as an assistant diagnostic tool for pathologists.

  16. Attempts to Improve Absolute Quantification of Cerebral Blood Flow in Dynamic Susceptibility Contrast Magnetic Resonance Imaging: A Simplified T1-Weighted Steady-State Cerebral Blood Volume Approach

    Energy Technology Data Exchange (ETDEWEB)

    Wirestam, R.; Knutsson, L.; Risberg, J.; Boerjesson, S.; Larsson, E.M.; Gustafson, L.; Passant, U.; Staahlberg, F. [Depts. of Medical Radiation Physics, Diagnostic Radiology, Psychiatry, and Psychogeriatrics, Lund Univ, Lund (Sweden)

    2007-07-15

    Background: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations. Purpose: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate. Material and Methods: 17 volunteers were investigated by DSC-MRI and 133Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = KxCBF(DSC). Results: Average whole-brain SPECT CBF was 40.1{+-}6.9 ml/min 100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2{+-}13.8 ml/mi 100 g. After correction with the calibration factor, a CBF(ss) of 42.7{+-}14.0 ml/min 100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality (R = 0.52). Conclusion: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference 133Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects.

  17. The Future of Pooling.

    Science.gov (United States)

    Young, Peter C.; Fone, Martin

    1997-01-01

    Discusses seven propositions underlying the strategies that insurance pools can, will, and must pursue: (1) risk management versus risk financing; (2) elimination of windfall advantages; (3) the maintenance of market-dominant status; (4) cost leadership; (5) client focus; (6) innovation and diversification; and (7) leadership challenges. A sidebar…

  18. An Automatic Cognitive Graph-Based Segmentation for Detection of Blood Vessels in Retinal Images

    Directory of Open Access Journals (Sweden)

    Rasha Al Shehhi

    2016-01-01

    Full Text Available This paper presents a hierarchical graph-based segmentation for blood vessel detection in digital retinal images. This segmentation employs some of perceptual Gestalt principles: similarity, closure, continuity, and proximity to merge segments into coherent connected vessel-like patterns. The integration of Gestalt principles is based on object-based features (e.g., color and black top-hat (BTH morphology and context and graph-analysis algorithms (e.g., Dijkstra path. The segmentation framework consists of two main steps: preprocessing and multiscale graph-based segmentation. Preprocessing is to enhance lighting condition, due to low illumination contrast, and to construct necessary features to enhance vessel structure due to sensitivity of vessel patterns to multiscale/multiorientation structure. Graph-based segmentation is to decrease computational processing required for region of interest into most semantic objects. The segmentation was evaluated on three publicly available datasets. Experimental results show that preprocessing stage achieves better results compared to state-of-the-art enhancement methods. The performance of the proposed graph-based segmentation is found to be consistent and comparable to other existing methods, with improved capability of detecting small/thin vessels.

  19. Radiolabeling human peripheral blood stem cells for positron emission tomography (PET imaging in young rhesus monkeys.

    Directory of Open Access Journals (Sweden)

    Alice F Tarantal

    Full Text Available These studies focused on a new radiolabeling technique with copper ((64Cu and zirconium ((89Zr for positron emission tomography (PET imaging using a CD45 antibody. Synthesis of (64Cu-CD45 and (89Zr-CD45 immunoconjugates was performed and the evaluation of the potential toxicity of radiolabeling human peripheral blood stem cells (hPBSC was assessed in vitro (viability, population doubling times, colony forming units. hPBSC viability was maintained as the dose of (64Cu-TETA-CD45 increased from 0 (92% to 160 µCi/mL (76%, p>0.05. Radiolabeling efficiency was not significantly increased with concentrations of (64Cu-TETA-CD45 >20 µCi/mL (p>0.50. Toxicity affecting both growth and colony formation was observed with hPBSC radiolabeled with ≥40 µCi/mL (p0.05, and a trend towards increased radiolabeling efficiency was noted as the dose of (89Zr-Df-CD45 increased, with a greater level of radiolabeling with 160 µCi/mL compared to 0-40 µCi/mL (p<0.05. A greater than 2,000 fold-increase in the level of (89Zr-Df-CD45 labeling efficiency was observed when compared to (64Cu-TETA-CD45. Similar to (64Cu-TETA-CD45, toxicity was noted when hPBSC were radiolabeled with ≥40 µCi/mL (p<0.05 (growth, colony formation. Taken together, 20 µCi/mL resulted in the highest level of radiolabeling efficiency without altering cell function. Young rhesus monkeys that had been transplanted prenatally with 25×10(6 hPBSC expressing firefly luciferase were assessed with bioluminescence imaging (BLI, then 0.3 mCi of (89Zr-Df-CD45, which showed the best radiolabeling efficiency, was injected intravenously for PET imaging. Results suggest that (89Zr-Df-CD45 was able to identify engrafted hPBSC in the same locations identified by BLI, although the background was high.

  20. Modeling of cerebral oxygen transport based on in vivo microscopic imaging of microvascular network structure, blood flow and oxygenation

    Directory of Open Access Journals (Sweden)

    Louis Gagnon

    2016-08-01

    Full Text Available Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1 interpretation of functional Magnetic Resonance Imaging (fMRI signals, and (2 investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These bottom-up models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.

  1. In vivo photoacoustic imaging of transverse blood flow using Doppler broadening of bandwidth

    OpenAIRE

    Yao, Junjie; Maslov, Konstantin I.; Shi, Yunfei; Taber, Larry A.; Lihong V. Wang

    2010-01-01

    A new method is proposed to measure transverse blood flow using photoacoustic Doppler broadening of bandwidth. By measuring bovine blood flowing through a plastic tube, the linear dependence of the broadening on the flow speed was validated. The blood flow of the microvasculature in a mouse ear and a chicken embryo (stage 16) was also studied.

  2. In vivo photoacoustic imaging of transverse blood flow by using Doppler broadening of bandwidth

    OpenAIRE

    Yao, Junjie; Maslov, Konstantin I.; Shi, Yunfei; Taber, Larry A.; Lihong V. Wang

    2010-01-01

    A method is proposed to measure transverse blood flow by using photoacoustic Doppler broadening of bandwidth. By measuring bovine blood flowing through a plastic tube, the linear dependence of the broadening on the flow speed was validated. The blood flow of the microvasculature in a mouse ear and a chicken embryo (stage 16) was also studied.

  3. Clinical application of /sup 99m/Tc-HM-PAO for cerebral blood flow imaging by SPECT. Comparison with cerebral blood flow study by PET

    Energy Technology Data Exchange (ETDEWEB)

    Inugami, Atsushi; Uemura, Kazuo; Shishido, Fumio; Tomura, Noriaki; Higano, Shuichi; Fujita, Hideaki; Kanno, Iwao

    1988-02-01

    Recently, a new tracer for cerebral blood flow (CBF) study; /sup 99m/Tc-labelled-hexamethyl-propyleneamine-oxime (/sup 99m/Tc-HM-PAO) was developed by Amersham international institute. In this paper, we reported the initial experience of tomographic CBF imaging with /sup 99m/Tc-HM-PAO in the comparison of CBF study using positron CT (PET) and 0 approx. 15 labelled CO/sub 2/. Thirty-nine patients with cerebro-vascular disease were examined mainly in the acute phase. All the subjects showed verious disturbances of CBF, which corresponded well to the PET study. However, the image-contrast with /sup 99m/Tc-HM-PAO were inferior to those of the PET study. /sup 99m/Tc-HM-PAO is considered to a good radiopharmaceutical which is readily applicable to eaven an emergency cases.

  4. What's Blood?

    Science.gov (United States)

    ... Rh" because scientists found it while studying Rhesus monkeys. If your blood is positive, you have this ... doctor. © 1995- The Nemours Foundation. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, ...

  5. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Directory of Open Access Journals (Sweden)

    Aaron B Simon

    Full Text Available Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL and Blood Oxygenation Level Dependent (BOLD imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF and cerebral oxygen metabolism (CMRO(2 that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

  6. A novel method of combining blood oxygenation and blood flow sensitive magnetic resonance imaging techniques to measure the cerebral blood flow and oxygen metabolism responses to an unknown neural stimulus.

    Science.gov (United States)

    Simon, Aaron B; Griffeth, Valerie E M; Wong, Eric C; Buxton, Richard B

    2013-01-01

    Simultaneous implementation of magnetic resonance imaging methods for Arterial Spin Labeling (ASL) and Blood Oxygenation Level Dependent (BOLD) imaging makes it possible to quantitatively measure the changes in cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO(2)) that occur in response to neural stimuli. To date, however, the range of neural stimuli amenable to quantitative analysis is limited to those that may be presented in a simple block or event related design such that measurements may be repeated and averaged to improve precision. Here we examined the feasibility of using the relationship between cerebral blood flow and the BOLD signal to improve dynamic estimates of blood flow fluctuations as well as to estimate metabolic-hemodynamic coupling under conditions where a stimulus pattern is unknown. We found that by combining the information contained in simultaneously acquired BOLD and ASL signals through a method we term BOLD Constrained Perfusion (BCP) estimation, we could significantly improve the precision of our estimates of the hemodynamic response to a visual stimulus and, under the conditions of a calibrated BOLD experiment, accurately determine the ratio of the oxygen metabolic response to the hemodynamic response. Importantly we were able to accomplish this without utilizing a priori knowledge of the temporal nature of the neural stimulus, suggesting that BOLD Constrained Perfusion estimation may make it feasible to quantitatively study the cerebral metabolic and hemodynamic responses to more natural stimuli that cannot be easily repeated or averaged.

  7. Label-free in vivo optical micro-angiography imaging of cerebral capillary blood flow within meninges and cortex in mice with the skull left intact

    Science.gov (United States)

    Jia, Yali; Wang, Ruikang K.

    2011-03-01

    Abnormal microcirculation within meninges is common in many neurological diseases. There is a need for an imaging method that is capable of visualizing functional meningeal microcirculations alone, preferably decoupled from the cortical blood flow. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing 3D images of dynamic blood perfusion within micro-circulatory tissue beds at an imaging depth up to ~2 mm, with an unprecedented imaging sensitivity to the blood flow at ~4 μm/s. In this study, we demonstrate the utility of ultra-high sensitive OMAG in imaging the detailed blood flow distributions, at a capillary level resolution, within meninges and cortex in mice with the cranium left intact. The results indicate that OMAG can be a valuable tool for the study of meningeal circulations.

  8. Reflection-mode photoacoustic microscopy using a hollow focused ultrasound transducer for in vivo imaging of blood vessels

    Institute of Scientific and Technical Information of China (English)

    Yuan Yi; Yang Si-Hua

    2012-01-01

    A reflection-mode photoacoustic microscope using a hollow focused ultrasound transducer is developed for highresolution in vivo imaging.A confocal structure of the laser and the ultrasound is used to improve the system resolution.The axial and lateral resolutions of the system are measured to be~32 μm and~58 μm,respectively.Ex vivo and in vivo modes are tested to validate the imaging capability of the photoacoustic microscope.The adjacent vein and artery can be seen clearly from the reconstructed photoacoustic images.The results demonstrate that the reflectionmode photoacoustic microscope can be used for high-resolution imaging of micro-blood vessels,which would be of great benefit for monitoring the neovascularization in tumor angiogenesis.

  9. Parametric renal blood flow imaging using [{sup 15}O]H{sub 2}O and PET

    Energy Technology Data Exchange (ETDEWEB)

    Kudomi, Nobuyuki; Liukko, Kaisa E.; Oikonen, Vesa J.; Tolvanen, Tuula [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); Koivuviita, Niina; Tertti, Risto; Metsaerinne, Kaj [University of Turku, Department of Medicine, Turku (Finland); Iida, Hidehiro [National Cardiovascular Center-Research Institute, Department of Investigative Radiology, Advanced Medical-Engineering Center, Suita, Osaka (Japan); Iozzo, Patricia [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); National Research Council, Institute of Clinical Physiology, Pisa (Italy); Nuutila, Pirjo [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); University of Turku, Department of Medicine, Turku (Finland)

    2009-04-15

    The quantitative assessment of renal blood flow (RBF) may help to understand the physiological basis of kidney function and allow an evaluation of pathophysiological events leading to vascular damage, such as renal arterial stenosis and chronic allograft nephropathy. The RBF may be quantified using PET with H{sub 2} {sup 15}O, although RBF studies that have been performed without theoretical evaluation have assumed the partition coefficient of water (p, ml/g) to be uniform over the whole region of renal tissue, and/or radioactivity from the vascular space (V{sub A}. ml/ml) to be negligible. The aim of this study was to develop a method for calculating parametric images of RBF (K{sub 1}, k{sub 2}) as well as V{sub A} without fixing the partition coefficient by the basis function method (BFM). The feasibility was tested in healthy subjects. A simulation study was performed to evaluate error sensitivities for possible error sources. The experimental study showed that the quantitative accuracy of the present method was consistent with nonlinear least-squares fitting, i.e. K{sub 1,BFM}=0.93K{sub 1,NLF}-0.11 ml/min/g (r=0.80, p<0.001), k{sub 2,BFM}=0.96k{sub 2,NLF}-0.13 ml/min/g (r=0.77, p<0.001), and V{sub A,BFM}=0.92V{sub A,NLF}-0.00 ml/ml (r=0.97, p<0.001). Values of the Akaike information criterion from this fitting were the smallest for all subjects except two. The quality of parametric images obtained was acceptable. The simulation study suggested that delay and dispersion time constants should be estimated within an accuracy of 2 s. V{sub A} and p cannot be neglected or fixed, and reliable measurement of even relative RBF values requires that V{sub A} is fitted. This study showed the feasibility of measurement of RBF using PET with H{sub 2} {sup 15}O. (orig.)

  10. CERN Electronics Pool presentations

    CERN Multimedia

    2011-01-01

    The CERN Electronics Pool has organised a series of presentations in collaboration with oscilloscope manufacturers. The last one will take place according to the schedule below.   Time will be available at the end of the presentation to discuss your personal needs. The Agilent presentation had to be postponed and will be organised later. -     Lecroy: Thursday, 24 November 2011, in 530-R-030, 14:00 to 16:30.

  11. Functional neuroanatomy in depressed patients with sexual dysfunction: blood oxygenation level dependent functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jong Chul [Chonnam National Univ. Hospital, Kwangju (Korea, Republic of)

    2004-06-15

    To demonstrate the functional neuroanatomy associated with sexual arousal visually evoked in depressed males who have underlying sexual dysfunction using Blood Oxygenation Level Dependent-based fMRI. Ten healthy volunteers (age range 21-55: mean 32.5 years), and 10 depressed subjects (age range 23-51: mean 34.4 years, mean Beck Depression Inventory score of 39.6 {+-} 5.9, mean Hamilton Rating Scale Depression (HAMD)-17 score of 33.5 {+-} 6.0) with sexual arousal dysfunction viewed erotic and neutral video films during functional magnetic resonance imaging (fMRI) with 1.5 T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 oblique planes using gradient-echo EPI (flip angle/TR/TE=90 .deg. /6000 ms/50 ms). The visual stimulation paradigm began with 60 sec of black screen, 150 sec of neutral stimulation with a documentary video film, 30 sec of black screen, 150 sec of sexual stimulation with an erotic video film followed by 30 sec of black screen. The brain activation maps and their quantification were analyzed by SPM99 program. There was a significant difference of brain activation between two groups during visual sexual stimulation. In depressed subjects, the level of activation during the visually evoked sexual arousal was significantly less than that of healthy volunteers, especially in the cerebrocortical areas of the hypothalamus, thalamus, caudate nucleus, and inferior and superior temporal gyri. On the other hand, the cerebral activation patterns during the neutral condition in both groups showed no significant differences ({rho} < 0.01). This study is the first demonstration of the functional neuroanatomy of the brain associated with sexual dysfunction in depressed patients using fMRI. In order to validate our physiological neuroscience results, further studies that would include patients with other disorders and sexual dysfunction, and depressed patients without sexual dysfunction and their treatment response are needed.

  12. Cerebral blood flow and cerebrovascular reserve capacity: estimation by dynamic magnetic resonance imaging.

    Science.gov (United States)

    Schreiber, W G; Gückel, F; Stritzke, P; Schmiedek, P; Schwartz, A; Brix, G

    1998-10-01

    We have developed a new method for estimation of regional CBF (rCBF) and cerebrovascular reserve capacity on a pixel-by-pixel basis by means of dynamic magnetic resonance imaging (MRI). Thirteen healthy volunteers, 8 patients with occlusion and/or high grade stenosis of the internal carotid artery (ICA), and 2 patients with acute stroke underwent dynamic susceptibility-weighted contrast enhanced MRI. Using principles of indicator dilution theory and deconvolution analysis, maps of rCBF, regional cerebral blood volume, and of the mean transit time (MTT) were calculated. In patients with ICA occlusion/stenosis, cerebrovascular reserve capacity was assessed by the rCBF increase after acetazolamide stimulation. Mean gray and white matter rCBF values in normals were 67.1 and 23.7 mL x 100 g(-1) x min(-1), respectively. Before acetazolamide stimulation, six of eight patients with ICA occlusions showed decreased rCBF values; and in seven patients increased MTT values were observed in tissue ipsilateral to the occlusion. After acetazolamide stimulation, decreased cerebrovascular reserve capacity was observed in five of eight patients with ICA occlusion. In acute stroke, rCBF in the central core of ischemia was less than 8 mL x 100 g(-1) x min(-1). In peri-infarct tissue, rCBF and MTT were higher than in unaffected tissue but rCBF was normal. Dynamic MRI provides important clinical information on the hemodynamic state of brain tissue in patients with occlusive cerebrovascular disease or acute stroke.

  13. Application of radionuclide imaging to hepatic impact injury in rabbits

    Institute of Scientific and Technical Information of China (English)

    金榕兵; 麻晓林; 温建良; 唐维佳

    2004-01-01

    Objective: To investigate the role and clinical value of radionuclide imaging in hepatic impact injuries in rabbits.Methods: Rabbits were experimentally impacted on the liver with BIM-IV bio-impact machine. Liver imaging was performed with 99mTc labeled sodium phytate. Liver blood pool imaging was performed with 99mTc -stannous pyrophosphate labeled red blood cells. The results of radionuclide imaging were compared with the anatomic results.Results: There was significant difference between the images of the injured liver and the control. Radio diminution and defect were shown in the injured liver areas. Various sorts of abnormal radioactivity distribution were observed with hepatic blood pool imaging. The results of the liver imaging and liver blood pool imaging were accorded with the results of the anatomic findings.Conclusions: Radionuclide imaging may well display the changes of hepatocellular structures and functions after injury, which is valuable in locating the concrete injured position and differentiating the injured degrees of liver.

  14. Fiber array based hyperspectral Raman imaging for chemical selective analysis of malaria-infected red blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Brückner, Michael [Leibniz Institute of Photonic Technology, 07745 Jena (Germany); Becker, Katja [Justus Liebig University Giessen, Biochemistry and Molecular Biology, 35392 Giessen (Germany); Popp, Jürgen [Leibniz Institute of Photonic Technology, 07745 Jena (Germany); Friedrich Schiller University Jena, Institute for Physical Chemistry, 07745 Jena (Germany); Friedrich Schiller University Jena, Abbe Centre of Photonics, 07745 Jena (Germany); Frosch, Torsten, E-mail: torsten.frosch@uni-jena.de [Leibniz Institute of Photonic Technology, 07745 Jena (Germany); Friedrich Schiller University Jena, Institute for Physical Chemistry, 07745 Jena (Germany); Friedrich Schiller University Jena, Abbe Centre of Photonics, 07745 Jena (Germany)

    2015-09-24

    A new setup for Raman spectroscopic wide-field imaging is presented. It combines the advantages of a fiber array based spectral translator with a tailor-made laser illumination system for high-quality Raman chemical imaging of sensitive biological samples. The Gaussian-like intensity distribution of the illuminating laser beam is shaped by a square-core optical multimode fiber to a top-hat profile with very homogeneous intensity distribution to fulfill the conditions of Koehler. The 30 m long optical fiber and an additional vibrator efficiently destroy the polarization and coherence of the illuminating light. This homogeneous, incoherent illumination is an essential prerequisite for stable quantitative imaging of complex biological samples. The fiber array translates the two-dimensional lateral information of the Raman stray light into separated spectral channels with very high contrast. The Raman image can be correlated with a corresponding white light microscopic image of the sample. The new setup enables simultaneous quantification of all Raman spectra across the whole spatial area with very good spectral resolution and thus outperforms other Raman imaging approaches based on scanning and tunable filters. The unique capabilities of the setup for fast, gentle, sensitive, and selective chemical imaging of biological samples were applied for automated hemozoin analysis. A special algorithm was developed to generate Raman images based on the hemozoin distribution in red blood cells without any influence from other Raman scattering. The new imaging setup in combination with the robust algorithm provides a novel, elegant way for chemical selective analysis of the malaria pigment hemozoin in early ring stages of Plasmodium falciparum infected erythrocytes. - Highlights: • Raman hyperspectral imaging allows for chemical selective analysis of biological samples with spatial heterogeneity. • A homogeneous, incoherent illumination is essential for reliable

  15. A reduced gastric corpus microvascular blood flow during Ivor-Lewis esophagectomy detected by laser speckle contrast imaging technique

    DEFF Research Database (Denmark)

    Ambrus, Rikard; Svendsen, Lars B; Secher, Niels H;

    2017-01-01

    BACKGROUND: Reduced microvascular blood flow is related to anastomotic insufficiency following esophagectomy, emphasizing a need for intraoperative monitoring of the microcirculation. This study evaluated if laser speckle contrast imaging (LSCI) was able to detect intraoperative changes in gastric......). The decrease in corpus microcirculation took place unrelated to central cardiovascular variables. CONCLUSION: Using LSCI technique, we identified a reduced microcirculation at the corpus area during open Ivor-Lewis esophagectomy. LSCI provides an option for real-time assessment of gastric microcirculation...

  16. Visualization of tumor-related blood vessels in human breast by photoacoustic imaging system with a hemispherical detector array

    Science.gov (United States)

    Toi, M.; Asao, Y.; Matsumoto, Y.; Sekiguchi, H.; Yoshikawa, A.; Takada, M.; Kataoka, M.; Endo, T.; Kawaguchi-Sakita, N.; Kawashima, M.; Fakhrejahani, E.; Kanao, S.; Yamaga, I.; Nakayama, Y.; Tokiwa, M.; Torii, M.; Yagi, T.; Sakurai, T.; Togashi, K.; Shiina, T.

    2017-01-01

    Noninvasive measurement of the distribution and oxygenation state of hemoglobin (Hb) inside the tissue is strongly required to analyze the tumor-associated vasculatures. We developed a photoacoustic imaging (PAI) system with a hemispherical-shaped detector array (HDA). Here, we show that PAI system with HDA revealed finer vasculature, more detailed blood-vessel branching structures, and more detailed morphological vessel characteristics compared with MRI by the use of breast shape deformation of MRI to PAI and their fused image. Morphologically abnormal peritumoral blood vessel features, including centripetal photoacoustic signals and disruption or narrowing of vessel signals, were observed and intratumoral signals were detected by PAI in breast cancer tissues as a result of the clinical study of 22 malignant cases. Interestingly, it was also possible to analyze anticancer treatment-driven changes in vascular morphological features and function, such as improvement of intratumoral blood perfusion and relevant changes in intravascular hemoglobin saturation of oxygen. This clinical study indicated that PAI appears to be a promising tool for noninvasive analysis of human blood vessels and may contribute to improve cancer diagnosis. PMID:28169313

  17. 3D real-time visualization of blood flow in cerebral aneurysms by light field particle image velocimetry

    Science.gov (United States)

    Carlsohn, Matthias F.; Kemmling, André; Petersen, Arne; Wietzke, Lennart

    2016-04-01

    Cerebral aneurysms require endovascular treatment to eliminate potentially lethal hemorrhagic rupture by hemostasis of blood flow within the aneurysm. Devices (e.g. coils and flow diverters) promote homeostasis, however, measurement of blood flow within an aneurysm or cerebral vessel before and after device placement on a microscopic level has not been possible so far. This would allow better individualized treatment planning and improve manufacture design of devices. For experimental analysis, direct measurement of real-time microscopic cerebrovascular flow in micro-structures may be an alternative to computed flow simulations. An application of microscopic aneurysm flow measurement on a regular basis to empirically assess a high number of different anatomic shapes and the corresponding effect of different devices would require a fast and reliable method at low cost with high throughout assessment. Transparent three dimensional 3D models of brain vessels and aneurysms may be used for microscopic flow measurements by particle image velocimetry (PIV), however, up to now the size of structures has set the limits for conventional 3D-imaging camera set-ups. On line flow assessment requires additional computational power to cope with the processing large amounts of data generated by sequences of multi-view stereo images, e.g. generated by a light field camera capturing the 3D information by plenoptic imaging of complex flow processes. Recently, a fast and low cost workflow for producing patient specific three dimensional models of cerebral arteries has been established by stereo-lithographic (SLA) 3D printing. These 3D arterial models are transparent an exhibit a replication precision within a submillimeter range required for accurate flow measurements under physiological conditions. We therefore test the feasibility of microscopic flow measurements by PIV analysis using a plenoptic camera system capturing light field image sequences. Averaging across a sequence of

  18. Image segmentation and classification of white blood cells with the extreme learning machine and the fast relevance vector machine.

    Science.gov (United States)

    Ravikumar, S

    2016-05-01

    White blood cells (WBCs) or leukocytes are an important part of the body's defense against infectious organisms and foreign substances. WBC segmentation is a challenging issue because of the morphological diversity of WBCs and the complex and uncertain background of blood smear images. The standard ELM classification techniques are used for WBC segmentation. The generalization performance of the ELM classifier has not achieved the maximum nearest accuracy of image segmentation. This paper gives a novel technique for WBC detection based on the fast relevance vector machine (Fast-RVM). Firstly, astonishingly sparse relevance vectors (RVs) are obtained while fitting the histogram by RVM. Next, the relevant required threshold value is directly sifted from these limited RVs. Finally, the entire connective WBC regions are segmented from the original image. The proposed method successfully works for WBC detection, and effectively reduces the effects brought about by illumination and staining. To achieve the maximum accuracy of the RVM classifier, we design a search for the best value of the parameters that tune its discriminant function, and upstream by looking for the best subset of features that feed the classifier. Therefore, this proposed RVM method effectively works for WBC detection, and effectively reduces the computational time and preserves the images.

  19. Integration of acoustic radiation force and optical imaging for blood plasma clot stiffness measurement.

    Science.gov (United States)

    Wang, Caroline W; Perez, Matthew J; Helmke, Brian P; Viola, Francesco; Lawrence, Michael B

    2015-01-01

    Despite the life-preserving function blood clotting serves in the body, inadequate or excessive blood clot stiffness has been associated with life-threatening diseases such as stroke, hemorrhage, and heart attack. The relationship between blood clot stiffness and vascular diseases underscores the importance of quantifying the magnitude and kinetics of blood's transformation from a fluid to a viscoelastic solid. To measure blood plasma clot stiffness, we have developed a method that uses ultrasound acoustic radiation force (ARF) to induce micron-scaled displacements (1-500 μm) on microbeads suspended in blood plasma. The displacements were detected by optical microscopy and took place within a micro-liter sized clot region formed within a larger volume (2 mL sample) to minimize container surface effects. Modulation of the ultrasound generated acoustic radiation force allowed stiffness measurements to be made in blood plasma from before its gel point to the stage where it was a fully developed viscoelastic solid. A 0.5 wt % agarose hydrogel was 9.8-fold stiffer than the plasma (platelet-rich) clot at 1 h post-kaolin stimulus. The acoustic radiation force microbead method was sensitive to the presence of platelets and strength of coagulation stimulus. Platelet depletion reduced clot stiffness 6.9 fold relative to platelet rich plasma. The sensitivity of acoustic radiation force based stiffness assessment may allow for studying platelet regulation of both incipient and mature clot mechanical properties.

  20. Magnetic resonance imaging of post-ischemic blood-brain barrier damage with PEGylated iron oxide nanoparticles

    Science.gov (United States)

    Liu, Dong-Fang; Qian, Cheng; An, Yan-Li; Chang, Di; Ju, Sheng-Hong; Teng, Gao-Jun

    2014-11-01

    Blood-brain barrier (BBB) damage during ischemia may induce devastating consequences like cerebral edema and hemorrhagic transformation. This study presents a novel strategy for dynamically imaging of BBB damage with PEGylated supermagnetic iron oxide nanoparticles (SPIONs) as contrast agents. The employment of SPIONs as contrast agents made it possible to dynamically image the BBB permeability alterations and ischemic lesions simultaneously with T2-weighted MRI, and the monitoring could last up to 24 h with a single administration of PEGylated SPIONs in vivo. The ability of the PEGylated SPIONs to highlight BBB damage by MRI was demonstrated by the colocalization of PEGylated SPIONs with Gd-DTPA after intravenous injection of SPION-PEG/Gd-DTPA into a mouse. The immunohistochemical staining also confirmed the leakage of SPION-PEG from cerebral vessels into parenchyma. This study provides a novel and convenient route for imaging BBB alteration in the experimental ischemic stroke model.

  1. Fiber array based hyperspectral Raman imaging for chemical selective analysis of malaria-infected red blood cells.

    Science.gov (United States)

    Brückner, Michael; Becker, Katja; Popp, Jürgen; Frosch, Torsten

    2015-09-24

    A new setup for Raman spectroscopic wide-field imaging is presented. It combines the advantages of a fiber array based spectral translator with a tailor-made laser illumination system for high-quality Raman chemical imaging of sensitive biological samples. The Gaussian-like intensity distribution of the illuminating laser beam is shaped by a square-core optical multimode fiber to a top-hat profile with very homogeneous intensity distribution to fulfill the conditions of Koehler. The 30 m long optical fiber and an additional vibrator efficiently destroy the polarization and coherence of the illuminating light. This homogeneous, incoherent illumination is an essential prerequisite for stable quantitative imaging of complex biological samples. The fiber array translates the two-dimensional lateral information of the Raman stray light into separated spectral channels with very high contrast. The Raman image can be correlated with a corresponding white light microscopic image of the sample. The new setup enables simultaneous quantification of all Raman spectra across the whole spatial area with very good spectral resolution and thus outperforms other Raman imaging approaches based on scanning and tunable filters. The unique capabilities of the setup for fast, gentle, sensitive, and selective chemical imaging of biological samples were applied for automated hemozoin analysis. A special algorithm was developed to generate Raman images based on the hemozoin distribution in red blood cells without any influence from other Raman scattering. The new imaging setup in combination with the robust algorithm provides a novel, elegant way for chemical selective analysis of the malaria pigment hemozoin in early ring stages of Plasmodium falciparum infected erythrocytes.

  2. The Diagnostic Value of Superb Microvascular Imaging (SMI) in Detecting Blood Flow Signals of Breast Lesions: A Preliminary Study Comparing SMI to Color Doppler Flow Imaging.

    Science.gov (United States)

    Ma, Yan; Li, Gang; Li, Jing; Ren, Wei-dong

    2015-09-01

    The correlation between color Doppler flow imaging (CDFI) and Superb Microvascular Imaging (SMI) for detecting blood flow in breast lesions was investigated, as was the diagnostic value of SMI in differentiating benign from malignant breast lesions.These lesions were evaluated using both CDFI and SMI according to Adler's method. Pathologic examination showed 57 malignant lesions and 66 benign lesions. The number of blood vessels in a single mass was detected by 2 techniques (SMI and CDFI), and the difference between the 2 values (SMI-CDFI) was calculated. The optimal threshold for the diagnosis of malignant neoplasms and the diagnostic performances of SMI, CDFI, and SMI-CDFI were calculated.For the total lesions and malignant lesions alone, the difference between SMI and CDFI for detecting blood flow was significant (P < 0.01), but the difference was not significant for benign lesions (P = 0.15). The area under the receiver operating characteristic curve was 0.73 (95% confidence interval [CI]: 0.64-0.82) for CDFI; 0.81 (95% CI: 0.74-0.89) for SMI; and 0.89 (95% CI: 0.82-0.95) for SMI-CDFI. Furthermore, the modality of "SMI-CDFI" showed the best diagnostic performance.SMI provides further microvessel information in breast lesions. The diagnostic modality of "SMI-CDFI" can improve the diagnostic performance of ultrasound in the differentiation between benign and malignant masses.

  3. Delayed 18F-fluorodeoxyglucose PET/CT imaging improves quantitation of atherosclerotic plaque inflammation

    DEFF Research Database (Denmark)

    Blomberg, Björn Alexander; Thomassen, Anders; Takx, Richard A P

    2014-01-01

    BACKGROUND: This study aimed to determine if delayed (18)F-fluorodeoxyglucose ((18)FDG) PET/CT imaging improves quantitation of atherosclerotic plaque inflammation. Blood-pool activity can disturb the arterial (18)FDG signal. With time, blood-pool activity declines. Therefore, delayed imaging can...... potentially improve quantitation of vascular inflammation. METHODS AND RESULTS: 40 subjects were prospectively assessed by dual-time-point PET/CT imaging at approximately 90 and 180 minutes after (18)FDG administration. For both time-points, global uptake of (18)FDG was determined in the carotid arteries...... and thoracic aorta by calculating the blood-pool corrected maximum standardized uptake value (cSUVMAX). A target-to-background ratio (TBR) was calculated to determine the contrast resolution at 90 and 180 minutes. Furthermore, we assessed whether the acquisition time-point affected the relation between c...

  4. Cardiac MRI. T2-mapping versus T2-weighted dark-blood TSE imaging for myocardial edema visualization in acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Nassenstein, K.; Nensa, F.; Schlosser, T.; Umutlu, L.; Lauenstein, T. [University Hospital Essen (Germany). Dept. of Diagnostic and Interventional Radiology and Neuroradiology; Bruder, O. [Elisabeth Hospital, Essen (Germany). Dept. of Cardiology and Angiology; Maderwald, S.; Ladd, M.E. [Duisburg-Essen Univ., Essen (Germany). Erwin L. Hahn Institute for Magnetic Resonance Imaging

    2014-02-15

    Purpose: To assess the diagnostic accuracy of T2 mapping for the detection of myocardial edema in acute myocardial infarction (AMI), and to compare this diagnostic accuracy with that of the current standard for myocardial edema imaging, which is T2w dark-blood TSE imaging. Materials and Methods: 29 patients with AMI were examined at 1.5 T. For the visualization of myocardial edema, T2 maps, calculated from three T2w SSFP images, and T2w dark-blood TSE images were acquired in standard short- and long-axis views. Cine SSFP images were acquired for the analysis of left ventricular (LV) function and late gadolinium enhancement images (LGE) for the visualization of myocardial necrosis. The T2 maps as well as the T2w dark-blood TSE images were evaluated twice independently from the cine SSFP and LGE images. The presence or absence of myocardial edema was rated visually for each LV segment. As the standard of reference, the infarct zone was defined based on the cine SSFP and the LGE images. Results: In this segment-based analysis, T2 mapping showed a sensitivity of 82 % and a specificity of 94 % for the detection of edema in the infarct zone. T2w dark-blood TSE imaging revealed a sensitivity of 50 % and a specificity of 98 %. T2 mapping showed a higher intra-rater agreement compared to T2w dark-blood TSE imaging ({kappa}: 0.87 vs. 0.76). Conclusions: T2 mapping allows for the visualization of myocardial edema in AMI with a high sensitivity and specificity, and features better diagnostic accuracy in terms of a higher sensitivity compared to T2w dark-blood TSE imaging. (orig.)

  5. The Productive Ligurian Pool

    CERN Document Server

    Casella, E; Couvelard, X; Caldeira, R M A

    2011-01-01

    In contrast with the behavior of the eddies in the open-ocean, the sub-mesoscale eddies generated in the constricted Ligurian Basin (NW Mediterranean), are unproductive but their combined effect, arranged in a rim-like fashion, contributes to the containment of a Productive Ligurian Pool (PLP). Data de- rived from MODIS satellite sensor showed persistent higher chlorophyll con- centrations in the centre of the basin, concurrent with high EKE values in its surroundings, derived from AVISO altimetry merged products. This sug- gested that this 'productive pool' is maintained by the intense (sub)mesoscale eddy activity in the rim. Numerical realistic experiments, using a Regional Ocean Model System, forced by MERCATOR and by a high-resolution COSMO- l7 atmospheric model, also showed that most of the sub-mesoscale eddies, during 2009 and 2010, are concentrated in the rim surrounding the basin, contributing to the formation of a basin-scale cyclonic gyre. We hypothesized that the interaction between eddies in the r...

  6. Quantitative assessment of the impact of blood pulsation on images of the pupil in infrared light.

    Science.gov (United States)

    Koprowski, Robert; Szmigiel, Marta; Kasprzak, Henryk; Wróbel, Zygmunt; Wilczyński, Sławomir

    2015-08-01

    Pulsation in the blood vessels of the eye has a big impact on the dynamics of the entire eyeball and its individual elements. Blood pulsation in the retina can be recorded by the pupil, whose size is also subject to dynamic changes. The study involved synchronous measurements of pupil size using a high-speed camera, and blood pulsation using a pulse oximeter placed on the ear lobe. In addition, there were no metrologically significant differences in the phase shift between the average brightness of the individual pupil quadrants. Blood pulsation in other ocular tissues can affect the dynamics of the optical properties of the eye. As demonstrated in this paper, it affects the pupil behavior and its parameters to a considerable extent.

  7. Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, H. (Den Sundhedsfaglige Kandidatuddannelse, Aarhus Universitet Bygning 1264, Aarhus (Denmark); University College Nordjylland, Aalborg (Denmark)), Email: hnt@ucn.dk; Steffensen, E. (Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark)); Larsson, E. M. (Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark); Uppsala University Hospital, Department of Radiology, Uppsala (Sweden))

    2012-02-15

    Background. Perfusion magnetic resonance imaging (MRI) is increasingly used in the evaluation of brain tumors. Relative cerebral blood volume (rCBV) is usually obtained by dynamic susceptibility contrast (DSC) MRI using normal appearing white matter as reference region. The emerging perfusion technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies. Purpose. To assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC-MRI using two different regions for normalization and two different measurement approaches. Material and Methods. Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and rCBV maps, with contralateral normal appearing white matter and cerebellum as reference regions. Larger ROIs were drawn for histogram analyses. The type and grade of the gliomas were obtained by histopathology. Statistical comparison was made between diffuse astrocytomas, anaplastic astrocytomas, and glioblastomas. Results. rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r = 0.60) and to the cerebellum (r = 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated (0.61 < r < 0.93), whereas for kurtosis and peak height, the correlation coefficient was about 0.3 when comparing rCBF and rCBV values for the same reference region. Neither rCBF nor rCBV quantification provided a statistically significant difference between the three types of gliomas. However, both rCBF and rCBV tended to increase with tumor grade and to be lower in patients who had undergone resection/treatment. Conclusion. rCBF measurements normalized to white matter

  8. Double-echo perfusion-weighted MR imaging: basic concepts and application in brain tumors for the assessment of tumor blood volume and vascular permeability

    OpenAIRE

    Uematsu, Hidemasa; Maeda, Masayuki

    2006-01-01

    Perfusion-weighted magnetic resonance (MR) imaging using contrast agents plays a key role in characterizing tumors of the brain. We have shown that double-echo perfusion-weighted MR imaging (DEPWI) is potentially useful in assessing brain tumors. Quantitative indices, such as tumor blood volume, are obtained using DEPWI, which allows correction of underestimation of tumor blood volume due to leakage of contrast agents from tumor vessels, in addition to simultaneous acquisition of tumor vessel...

  9. Synaptic vesicle pools: an update

    Directory of Open Access Journals (Sweden)

    Annette Denker

    2010-10-01

    Full Text Available During the last few decades synaptic vesicles have been assigned to a variety of functional and morphological classes or pools. We have argued in the past (Rizzoli SO and Betz WJ, 2005, Synaptic vesicle pools, Nat. Rev. Neurosci. 6, 57-69 that synaptic activity in several preparations is accounted for by the function of three vesicle pools: the readily releasable pool (docked at active zones and ready to go upon stimulation, the recycling pool (scattered throughout the nerve terminals and recycling upon moderate stimulation, and finally the reserve pool (occupying most of the vesicle clusters and only recycling upon strong stimulation. We discuss here the advancements in the vesicle pool field which took place in the ensuing years, focusing on the behavior of different pools under both strong stimulation and physiological activity. Several new findings have enhanced the three-pool model, with, for example, the disparity between recycling and reserve vesicles being underlined by the observation that the former are mobile, while the latter are fixed. Finally, a number of altogether new concepts have also evolved such as the current controversy on the identity of the spontaneously recycling vesicle pool.

  10. MRA Images Identification of the Artery Blood Vessel of the Knee with SOM LVQ Neural Networks as Auxiliary.

    Science.gov (United States)

    Huang, Hung-Chun; Chien, Chia-Hung; Shih, Ting-Fang; Chong, Fok-Ching

    2005-01-01

    The ways of angiography are divided into two kinds at present: the invasive type and the non invasive type. Because the magnetic resonance angiography (MRA) has advantages of the non invasive type, thus people can accept MRA more easily. Presently, to diagnoses for the initial stage triage of the blood vessel on clinic by MRA mostly. We to be allowed to see clearly that the shape of lower limb artery which like the dendrite and the blood vessel is thick from the trunk to the thin branch, also we can see the narrow embolism and the blocked place through MRA. This study is aiming at the image of artery of blood vessel by MRA assay, and is attempting to use two-dimensional structure of SOM and LVQ to make out topologies for the shape of artery of blood vessel. We expect that MRA could be useful tools for earlier on the quick triage and auxiliary diagnosis of doctors. By actual examples truly prove that patients after peripheral arterial occlusive disease (PAOD) treatment can diagnose effectively, shorten the time of patients waiting for reports and improve the whole efficiency of the medical treatment system.

  11. Specular reflection based sensing surface deformation of gas tungsten arc weld pool

    Institute of Scientific and Technical Information of China (English)

    Zhang Shiliang; Gao Jinqiang; Wu Chuansong; Zhang Yuming

    2007-01-01

    A sensing system is developed to measure the weld pool boundary and pool surface deformation in gas tungsten arc welding. LaserStrobe technique is used to eliminate the strong arc light interference, and specular reflection from the pool surface is sensed to describe the relation between the deformed stripes and pool surface depression. Clear images of both the pool boundary and the deformed stripes edges are obtained during gas tungsten arc welding process, which lays foundation for real-time monitoring the pool surface depression and weld penetration.

  12. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  13. Voxel-wise relationships between distribution volume ratio and cerebral blood flow: implications for analysis of β-amyloid images

    Science.gov (United States)

    Sojkova, Jitka; Goh, Joshua; Bilgel, Murat; Landman, Bennett; Yang, Xue; Zhou, Yun; An, Yang; Beason-Held, Lori L.; Kraut, Michael A.; Wong, Dean F.; Resnick, Susan M.

    2017-01-01

    Quantification of β-amyloid (Aβ) in vivo is often accomplished using the distribution volume ratio (DVR), based on a simplified reference tissue model. We investigated the local relationships between DVR and cerebral blood flow (CBF), as well as relative blood flow (R1), in nondemented older adults. Methods Fifty-five nondemented participants (mean age 78.5 years) in the Baltimore Longitudinal Study of Aging underwent 15O-H2O PET CBF and dynamic 11C-PiB-PET. 15O-H2O PET images were normalized and smoothed using SPM. A simplified reference tissue model with linear regression and spatial constraints was used to generate parametric DVR images. The DVR images were regressed on CBF images on a voxel-by-voxel basis using robust Biological Parametric Mapping, adjusting for age and sex (FDR p=0.05, k=50). DVR images were also regressed on R1 images, a measure of the transport rate constant from vascular space to tissue. All analyses were performed in the entire sample, and in high and low tertiles of mean cortical DVR. Results Voxel-based analyses showed that increased DVR is associated with increased CBF in frontal, parietal, temporal, and occipital cortices. However, this association appears to spare regions that typically show early β-amyloid (Aβ) deposition. A more robust relationship between DVR and CBF was observed in the lowest tertile of DVR, i.e., negligible cortical Aβ load, compared to the highest tertile of cortical DVR and Aβ load. Spatial distributions of the DVR-CBF and DVR-R1 correlations showed similar patterns. No reliable negative voxel-wise relationships between DVR and CBF or R1 were observed. Conclusion Robust associations between DVR and CBF at negligible Aβ levels, together with similar spatial distributions of DVR-CBF and DVR-R1 correlations, suggest that regional distribution of DVR reflects blood flow and tracer influx rather than pattern of Aβ deposition in those with minimal Aβ load. DVR-CBF associations in individuals with higher DVR

  14. Relative indexes of cutaneous blood perfusion measured by real-time laser Doppler imaging (LDI) in healthy volunteers.

    Science.gov (United States)

    Seyed Jafari, S Morteza; Schawkat, Megir; Van De Ville, Dimitri; Shafighi, Maziar

    2014-07-01

    We used real-time LDI to study regional variations in microcirculatory perfusion in healthy candidates to establish a new methodology for global perfusion body mapping that is based on intra-individual perfusion index ratios. Our study included 74 (37 female) healthy volunteers aged between 22 and 30 years (mean 24.49). Imaging was performed using a recent microcirculation-imaging camera (EasyLDI) for different body regions of each volunteer. The perfusion values were reported in Arbitrary Perfusion Units (APU). The relative perfusion indexes for each candidate's body region were then obtained by normalization with the perfusion value of the forehead. Basic parameters such as weight, height, and blood pressure were also measured and analyzed. The highest mean perfusion value was reported in the forehead area (259.21APU). Mean perfusion in the measured parts of the body correlated positively with mean forehead value, while there was no significant correlation between forehead blood perfusion values and room temperature, BMI, systolic blood pressure and diastolic blood pressure (p=0.420, 0.623, 0.488, 0.099, respectively). Analysis of the data showed that perfusion indexes were not significantly different between male and female volunteers except for the ventral upper arm area (p=.001). LDI is a non-invasive, fast technique that opens several avenues for clinical applications. The mean perfusion indexes are useful in clinical practice for monitoring patients before and after surgical interventions. Perfusion values can be predicted for different body parts for patients only by taking the forehead perfusion value and using the perfusion index ratios to obtain expected normative perfusion values.

  15. DETECTION AND ANALYSIS OF WELD POOL SHAPE FOR CO2 SHORT CIRCUITING ARC WELDING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A general industrial CCD(ICCD) camera is redesigned to detect the weld pool without arc at the period of short circuiting,so that the interference of arc and spatter during CO2 short circuiting arc welding is eliminated. Through the analysis of weld pool image, both size parameters (such as weld pool area A, weld pool length L1, L2 and weld pool breadth b) and contour parameters (bi which describe the curves of weld pool boundany) ,which could indicate the shape features of weld pool, had been defined to express weld pool information quantitatively. The investigation of the relationships between weld pool shape parameters and welding process parameters may be beneficial to the quality control of CO2 welding.

  16. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez D, J.; Cordova F, T. [Universidad de Guanajuato, Campus Leon, Departamento de Ingenieria Fisica, Loma del Bosque No. 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Cruz A, I., E-mail: hernandezdj.gto@gmail.com [CONACYT, Centro de Investigacion en Matematicas, A. C., Jalisco s/n, Col. Valenciana, 36000 Guanajuato, Gto. (Mexico)

    2015-10-15

    This paper presents a novel presents an approach based on differences of intensities for the identification of vascular structures in medical images from MRI studies of type time of flight method (TOF). The plating method hypothesis gave high intensities belonging to the vascular system image type TOF can be segmented by thresholding of the histogram. The enhanced vascular structures is performed using the filter Vesselness, upon completion of a decision based on fuzzy thresholding minimizes error in the selection of vascular structures. It will give a brief introduction to the vascular system problems and how the images have helped diagnosis, is summarized the physical history of the different imaging modalities and the evolution of digital images with computers. Segmentation and 3-D reconstruction became image type time of flight; these images are typically used in medical diagnosis of cerebrovascular diseases. The proposed method has less error in segmentation and reconstruction of volumes related to the vascular system, clear images and less noise compared with edge detection methods. (Author)

  17. Detection of rheumatoid arthritis in humans by fluorescence imaging

    Science.gov (United States)

    Ebert, Bernd; Dziekan, Thomas; Weissbach, Carmen; Mahler, Marianne; Schirner, Michael; Berliner, Birgitt; Bauer, Daniel; Voigt, Jan; Berliner, Michael; Bahner, Malte L.; Macdonald, Rainer

    2010-02-01

    The blood pool agent indo-cyanine green (ICG) has been investigated in a prospective clinical study for detection of rheumatoid arthritis using fluorescence imaging. Temporal behavior as well as spatial distribution of fluorescence intensity are suited to differentiate healthy and inflamed finger joints after i.v. injection of an ICG bolus.

  18. Effect of Post-Reconstruction Gaussian Filtering on Image Quality and Myocardial Blood Flow Measurement with N-13 Ammonia PET

    Directory of Open Access Journals (Sweden)

    Hyeon Sik Kim

    2014-10-01

    Full Text Available Objective(s: In order to evaluate the effect of post-reconstruction Gaussian filtering on image quality and myocardial blood flow (MBF measurement by dynamic N-13 ammonia positron emission tomography (PET, we compared various reconstruction and filtering methods with image characteristics. Methods: Dynamic PET images of three patients with coronary artery disease (male-female ratio of 2:1; age: 57, 53, and 76 years were reconstructed, using filtered back projection (FBP and ordered subset expectation maximization (OSEM methods. OSEM reconstruction consisted of OSEM_2I, OSEM_4I, and OSEM_6I with 2, 4, and 6 iterations, respectively. The images, reconstructed and filtered by Gaussian filters of 5, 10, and 15 mm, were obtained, as well as non-filtered images. Visual analysis of image quality (IQ was performed using a 3-grade scoring system by 2 independent readers, blinded to the reconstruction and filtering methods of stress images. Then, signal-to-noise ratio (SNR was calculated by noise and contrast recovery (CR. Stress and rest MBF and coronary flow reserve (CFR were obtained for each method. IQ scores, stress and rest MBF, and CFR were compared between the methods, using Chi-square and Kruskal-Wallis tests. Results: In the visual analysis, IQ was significantly higher by 10 mm Gaussian filtering, compared to other sizes of filter (PP=0.923 and 0.855 for readers 1 and 2, respectively. SNR was significantly higher in 10 mm Gaussian filter. There was a significant difference in stress and rest MBF between several vascular territories. However CFR was not significantly different according to various filtering methods. Conclusion: Post-reconstruction Gaussian filtering with a filter size of 10 mm significantly enhances the IQ of N-13 ammonia PET-CT, without changing the results of CFR calculation. .

  19. Medical image of the week: pneumatosis intestinalis secondary to massive acute blood loss

    Directory of Open Access Journals (Sweden)

    Assar S

    2013-10-01

    Full Text Available The patient was a 32 year-old male with a past medical history significant for end stage liver disease secondary to severe alcoholism who was found with an altered mental status. In the emergency department, the patient divulged he had been throwing up blood clots in the preceding days. Shortly into his presentation he began throwing up voluminous bright red blood. Initial hemoglobin concentration was 2.8 mg/dL. CT scan of the abdomen revealed pneumatosis within the ascending colon, small bowel, and mesenteric veins. Despite massive transfusion efforts and two episodes of successful cardiac resuscitation the patient expired.

  20. Optical characterization of red blood cells from individuals with sickle cell trait and disease in Tanzania using quantitative phase imaging

    Science.gov (United States)

    Jung, Jaehwang; Matemba, Lucas E.; Lee, Kyeoreh; Kazyoba, Paul E.; Yoon, Jonghee; Massaga, Julius J.; Kim, Kyoohyun; Kim, Dong-Jin; Park, Yongkeun

    2016-08-01

    Sickle cell disease (SCD) is common across Sub-Saharan Africa. However, the investigation of SCD in this area has been significantly limited mainly due to the lack of research facilities and skilled personnel. Here, we present optical measurements of individual red blood cells from healthy individuals and individuals with SCD and sickle cell trait in Tanzania using the quantitative phase imaging technique. By employing a quantitative phase imaging unit, an existing microscope in a clinic is transformed into a powerful quantitative phase microscope providing measurements on the morphological, biochemical, and biomechanical properties of individual cells. The present approach will open up new opportunities for cost-effective investigation and diagnosis of several diseases in low resource environments.

  1. Optical characterization of red blood cells from individuals with sickle cell trait and disease in Tanzania using quantitative phase imaging

    CERN Document Server

    Jung, JaeHwang; Lee, KyeoReh; Kazyoba, Paul E; Yoon, Jonghee; Massaga, Julius J; Kim, Kyoohyun; Kim, Dong-Jin; Park, YongKeun

    2016-01-01

    Sickle cell disease (SCD) is common across Sub-Saharan Africa. However, the investigation of SCD in this area has been significantly limited mainly due to the lack of research facilities and skilled personnel. Here, we present optical measurements of individual red blood cells (RBCs) from healthy individuals and individuals with SCD and sickle cell trait in Tanzania using the quantitative phase imaging technique. By employing a quantitative phase imaging unit (QPIU), an existing microscope in a clinic is transformed into a powerful quantitative phase microscope providing measurements on the morphological, biochemical, and biomechanical properties of individual cells. The present approach will open up new opportunities for cost-effective investigation and diagnosis of several diseases in low resource environments.

  2. Image-based modeling of blood flow and oxygen transfer in feto-placental capillaries

    Science.gov (United States)

    Pearce, Philip; Jensen, Oliver

    2016-11-01

    During pregnancy, oxygen diffuses from maternal to fetal blood through the placenta. At the smallest scale of the feto-placental vasculature are the "terminal villi", bulbous structures that are thought to be the main sites for oxygen transfer in the final trimester of pregnancy. The objective of this study is to investigate blood flow and oxygen transfer in the terminal villi of the placenta. Three-dimensional representations of villous and capillary surfaces, obtained from confocal laser scanning microscopy, are converted to finite-element meshes. Simulations of blood flow and oxygen transfer are performed to calculate the vascular flow resistance of the capillaries and the total oxygen transfer rate from the maternal blood. Scaling arguments, which predict the oxygen transfer across a range of Peclet numbers, are shown to be an efficient tool for quantifying the effect of statistical variability and experimental uncertainty. The effect of commonly observed localised dilations in the fetal vasculature on oxygen transfer is quantified using an idealised model in a simplified geometry. The model predicts how, for a fixed pressure drop through a capillary, oxygen transfer is maximised by an optimal shape of the dilation, leading to an increase in oxygen transfer of up to 15%.

  3. PET tracers for imaging of ABC transporters at the blood-brain barrier : Principles and Strategies

    NARCIS (Netherlands)

    Luurtsema, Gert; Elsinga, Philip; Dierckx, Rudi; Boellaard, Ronald; van Waarde, Aren

    2016-01-01

    ABC transporters at the human blood-brain barrier protect the brain against the entry of harmful compounds but may also limit (or prevent) the cerebral entry of therapeutic drugs (e.g. anti-epileptics, antidepressants and antipsychotics). The efflux function of these transporters may be impaired in

  4. Image-derived and arterial blood sampled input functions for quantitative PET imaging of the angiotensin II subtype 1 receptor in the kidney

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Tao; Tsui, Benjamin M. W.; Li, Xin; Vranesic, Melin; Lodge, Martin A.; Gulaldi, Nedim C. M.; Szabo, Zsolt, E-mail: zszabo@jhmi.edu [Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287 (United States)

    2015-11-15

    Purpose: The radioligand {sup 11}C-KR31173 has been introduced for positron emission tomography (PET) imaging of the angiotensin II subtype 1 receptor in the kidney in vivo. To study the biokinetics of {sup 11}C-KR31173 with a compartmental model, the input function is needed. Collection and analysis of arterial blood samples are the established approach to obtain the input function but they are not feasible in patients with renal diseases. The goal of this study was to develop a quantitative technique that can provide an accurate image-derived input function (ID-IF) to replace the conventional invasive arterial sampling and test the method in pigs with the goal of translation into human studies. Methods: The experimental animals were injected with [{sup 11}C]KR31173 and scanned up to 90 min with dynamic PET. Arterial blood samples were collected for the artery derived input function (AD-IF) and used as a gold standard for ID-IF. Before PET, magnetic resonance angiography of the kidneys was obtained to provide the anatomical information required for derivation of the recovery coefficients in the abdominal aorta, a requirement for partial volume correction of the ID-IF. Different image reconstruction methods, filtered back projection (FBP) and ordered subset expectation maximization (OS-EM), were investigated for the best trade-off between bias and variance of the ID-IF. The effects of kidney uptakes on the quantitative accuracy of ID-IF were also studied. Biological variables such as red blood cell binding and radioligand metabolism were also taken into consideration. A single blood sample was used for calibration in the later phase of the input function. Results: In the first 2 min after injection, the OS-EM based ID-IF was found to be biased, and the bias was found to be induced by the kidney uptake. No such bias was found with the FBP based image reconstruction method. However, the OS-EM based image reconstruction was found to reduce variance in the subsequent

  5. Longitudinal Monitoring of Hepatic Blood Flow before and after TIPS by Using 4D-Flow MR Imaging

    Science.gov (United States)

    Bannas, Peter; Roldán-Alzate, Alejandro; Johnson, Kevin M.; Woods, Michael A.; Ozkan, Orhan; Motosugi, Utaroh; Wieben, Oliver; Reeder, Scott B.; Kramer, Harald

    2016-01-01

    Purpose To demonstrate the feasibility of four-dimensional (4D)– flow magnetic resonance (MR) imaging for noninvasive longitudinal hemodynamic monitoring of hepatic blood flow before and after transjugular intrahepatic portosystemic shunt (TIPS) placement. Materials and Methods The institutional review board approved this prospective Health Insurance Portability and Accountability Act compliant study with written informed consent. Four-dimensional–flow MR imaging was performed in seven patients with portal hypertension and refractory ascites before and 2 and 12 weeks after TIPS placement by using a time-resolved three-dimensional radial phase-contrast acquisition. Flow and peak velocity measurements were obtained in the superior mesenteric vein (SMV), splenic vein (SV), portal vein (PV), and the TIPS. Flow volumes and peak velocities in each vessel, as well as the ratio of in-stent to PV flow, were compared before and after TIPS placement by using analysis of variance. Results Flow volumes significantly increased in the SMV (0.24 L/ min; 95% confidence interval [CI]: 0.07, 0.41), SV (0.31 L/min; 95% CI: 0.07, 0.54), and PV (0.88 L/min; 95% CI: 0.06, 1.70) after TIPS placement (all P .11). Ascites resolved in six of seven patients. In those with resolved ascites, the TIPS-to-PV flow ratio was 0.8 ± 6 0.2 and 0.9 ± 0.2 at the two post-TIPS time points, respectively, while the observed ratios were 4.6 and 4.3 in the patient with refractory ascites at the two post-TIPS time points, respectively. In this patient, 4D-flow MR imaging demonstrated arterio-portal-venous shunting, with draining into the TIPS. Conclusion Four-dimensional–flow MR imaging is feasible for noninvasive longitudinal hemodynamic monitoring of hepatic blood flow before and after TIPS placement. PMID:27171019

  6. In vivo functional imaging of blood flow and wall strain rate in outflow tract of embryonic chick heart using ultrafast spectral domain optical coherence tomography

    Science.gov (United States)

    Li, Peng; Yin, Xin; Shi, Liang; Rugonyi, Sandra; Wang, Ruikang K.

    2012-09-01

    During cardiac development, the cardiac wall and flowing blood are two important cardiac tissues that constantly interact with each other. This dynamic interaction defines appropriate biomechanical environment to which the embryonic heart is exposed. Quantitative assessment of the dynamic parameters of wall tissues and blood flow is required to further our understanding of cardiac development. We report the use of an ultrafast 1310-nm dual-camera spectral domain optical coherence tomography (SDOCT) system to characterize/image, in parallel, the dynamic radial strain rate of the myocardial wall and the Doppler velocity of the underlying flowing blood within an in vivo beating chick embryo. The OCT system operates at 184-kHz line scan rate, providing the flexibility of imaging the fast blood flow and the slow tissue deformation within one scan. The ability to simultaneously characterize tissue motion and blood flow provides a useful approach to better understand cardiac dynamics during early developmental stages.

  7. Renal Blood Oxygenation Level-dependent Imaging in Longitudinal Follow-up of Donated and Remaining Kidneys.

    Science.gov (United States)

    Seif, Maryam; Eisenberger, Ute; Binser, Tobias; Thoeny, Harriet C; Krauer, Fabienne; Rusch, Aurelia; Boesch, Chris; Vogt, Bruno; Vermathen, Peter

    2016-06-01

    Purpose To determine renal oxygenation changes associated with uninephrectomy and transplantation in both native donor kidneys and transplanted kidneys by using blood oxygenation level-dependent (BOLD) MR imaging. Materials and Methods The study protocol was approved by the local ethics committee. Thirteen healthy kidney donors and their corresponding recipients underwent kidney BOLD MR imaging with a 3-T imager. Written informed consent was obtained from each subject. BOLD MR imaging was performed in donors before uninephrectomy and in donors and recipients 8 days, 3 months, and 12 months after transplantation. R2* values, which are inversely related to tissue partial pressure of oxygen, were determined in the cortex and medulla. Longitudinal R2* changes were statistically analyzed by using repeated measures one-way analysis of variance with post hoc pair-wise comparisons. Results R2* values in the remaining kidneys significantly decreased early after uninephrectomy in both the medulla and cortex (P kidneys, R2* remained stable during the first year after transplantation, with no significant change. Among donors, cortical R2* was found to be negatively correlated with estimated glomerular filtration rate (R = -0.47, P kidneys. (©) RSNA, 2016.

  8. Comparison of cerebral blood flow velocity estimation with cranial ultrasound imaging for early prediction of outcome in preterm infants.

    Science.gov (United States)

    Rennie, J M; Coughtrey, H; Morley, R; Evans, D H

    1995-01-01

    Seventy-four low birth weight infants underwent serial measurements of cerebral blood flow velocity (CBFV) using Doppler ultrasound together with ultrasound imaging of the brain. Surviving infants were examined and assessed using the Bayley scales of mental and motor development at 18 months post-term. There were no significant differences in mean CBFV between normal and impaired infants. Infants with abnormal neurological signs (n = 6) or developmental delay (n = 3) did not show the usual steady rise in CBFV during the first few days of life. Four of nine had a rise, then a fall in CBFV compared with 4 of 31 with complete data in the normal group. This difference is significant (chi 2 = 4.3, p = 0.03). The magnitude of the percentage increase between day 1 and day 3 was also smaller in the abnormal group (median 0% vs. 39%, Mann-Whitney p = 0.03). A structural abnormality seen on the cranial ultrasound image was a better predictor of adverse outcome than an abnormal CBFV pattern, with a better sensitivity and specificity (66% and 97% for imaging compared to 44% and 87% for CBFV). The addition of serial ultrasound Doppler measurements of CBFV did not improve the prediction of outcome obtained using ultrasound imaging alone.

  9. Measurement of meningeal blood vessel diameter in vivo with a plug-in for ImageJ.

    Science.gov (United States)

    Fischer, Michael J M; Uchida, Sae; Messlinger, Karl

    2010-09-01

    Changes in blood vessel diameter can be measured manually, but this is time-consuming and often impractical. For automatic measurement commercial solutions are available, but the proprietary algorithms and their potential shortcomings are not known to the user. We present an approach with a CCD camera for image acquisition combined with free and open source ImageJ software for offline analysis. A subtraction image allows for the evaluation of the diameter changes throughout the field of view. A full width at half-maximum algorithm plug-in was written to measure the vessel diameter. For a given line across a vessel, the results of five measurements with parallel shifts throughout an image stack are copied to the clipboard. For validation of this method an established in vivo model was used, namely vascular changes in the rat dura mater, reflecting the activity of the afferent neurons. Vasoconstriction of the meningeal arterioles induced by local electrical stimulation of the dura was inhibited by intravenous administration of the adrenoceptor antagonist phentolamine and amplified by the CGRP receptor antagonist olcegepant. The described methods allow the user to quickly evaluate vessel diameter changes in the whole acquired field at any selected position.

  10. Segmentation of left atrial intracardiac ultrasound images for image guided cardiac ablation therapy

    Science.gov (United States)

    Rettmann, M. E.; Stephens, T.; Holmes, D. R.; Linte, C.; Packer, D. L.; Robb, R. A.

    2013-03-01

    Intracardiac echocardiography (ICE), a technique in which structures of the heart are imaged using a catheter navigated inside the cardiac chambers, is an important imaging technique for guidance in cardiac ablation therapy. Automatic segmentation of these images is valuable for guidance and targeting of treatment sites. In this paper, we describe an approach to segment ICE images by generating an empirical model of blood pool and tissue intensities. Normal, Weibull, Gamma, and Generalized Extreme Value (GEV) distributions are fit to histograms of tissue and blood pool pixels from a series of ICE scans. A total of 40 images from 4 separate studies were evaluated. The model was trained and tested using two approaches. In the first approach, the model was trained on all images from 3 studies and subsequently tested on the 40 images from the 4th study. This procedure was repeated 4 times using a leave-one-out strategy. This is termed the between-subjects approach. In the second approach, the model was trained on 10 randomly selected images from a single study and tested on the remaining 30 images in that study. This is termed the within-subjects approach. For both approaches, the model was used to automatically segment ICE images into blood and tissue regions. Each pixel is classified using the Generalized Liklihood Ratio Test across neighborhood sizes ranging from 1 to 49. Automatic segmentation results were compared against manual segmentations for all images. In the between-subjects approach, the GEV distribution using a neighborhood size of 17 was found to be the most accurate with a misclassification rate of approximately 17%. In the within-subjects approach, the GEV distribution using a neighborhood size of 19 was found to be the most accurate with a misclassification rate of approximately 15%. As expected, the majority of misclassified pixels were located near the boundaries between tissue and blood pool regions for both methods.

  11. Magnetic resonance imaging of blood brain/nerve barrier dysfunction and leukocyte infiltration: closely related or discordant?

    Directory of Open Access Journals (Sweden)

    Gesa eWeise

    2012-12-01

    Full Text Available Unlike other organs the nervous system is secluded from the rest of the organism by the blood brain (BBB or blood nerve barrier (BNB preventing passive influx of fluids from the circulation. Similarly, leukocyte entry to the nervous system is tightly controlled. Breakdown of these barriers and cellular inflammation are hallmarks of inflammatory as well as ischemic neurological diseases and thus represent potential therapeutic targets. The spatiotemporal relationship between BBB/BNB disruption and leukocyte infiltration has been a matter of debate. We here review contrast-enhanced magnetic resonance imaging (MRI as a non-invasive tool to depict barrier dysfunction and its relation to macrophage infiltration in the central and peripheral nervous system under pathological conditions. Novel experimental contrast agents like Gadofluorine M (Gf allow more sensitive assessment of BBB dysfunction than conventional Gadolinium (Gd-DTPA-enhanced MRI. In addition, Gf facilitates visualization of functional and transient alterations of the BBB remote from lesions. Cellular contrast agents such as superparamagnetic iron oxide particles (SPIO and perfluorocarbons (PFC enable assessment of leukocyte (mainly macrophage infiltration by MR technology. Combined use of these MR contrast agents disclosed that leukocytes can enter the nervous system independent from a disturbance of the BBB, and vice versa, a dysfunctional BBB/BNB by itself is not sufficient to attract inflammatory cells from the circulation. We will illustrate these basic imaging findings in animal models of multiple sclerosis (MS, cerebral ischemia and traumatic nerve injury and review corresponding findings in patients.

  12. Magnetic resonance imaging of blood brain/nerve barrier dysfunction and leukocyte infiltration: closely related or discordant?

    Science.gov (United States)

    Weise, Gesa; Stoll, Guido

    2012-01-01

    Unlike other organs the nervous system is secluded from the rest of the organism by the blood brain barrier (BBB) or blood nerve barrier (BNB) preventing passive influx of fluids from the circulation. Similarly, leukocyte entry to the nervous system is tightly controlled. Breakdown of these barriers and cellular inflammation are hallmarks of inflammatory as well as ischemic neurological diseases and thus represent potential therapeutic targets. The spatiotemporal relationship between BBB/BNB disruption and leukocyte infiltration has been a matter of debate. We here review contrast-enhanced magnetic resonance imaging (MRI) as a non-invasive tool to depict barrier dysfunction and its relation to macrophage infiltration in the central and peripheral nervous system under pathological conditions. Novel experimental contrast agents like Gadofluorine M (Gf) allow more sensitive assessment of BBB dysfunction than conventional Gadolinium (Gd)-DTPA enhanced MRI. In addition, Gf facilitates visualization of functional and transient alterations of the BBB remote from lesions. Cellular contrast agents such as superparamagnetic iron oxide particles (SPIO) and perfluorocarbons enable assessment of leukocyte (mainly macrophage) infiltration by MR technology. Combined use of these MR contrast agents disclosed that leukocytes can enter the nervous system independent from a disturbance of the BBB, and vice versa, a dysfunctional BBB/BNB by itself is not sufficient to attract inflammatory cells from the circulation. We will illustrate these basic imaging findings in animal models of multiple sclerosis, cerebral ischemia, and traumatic nerve injury and review corresponding findings in patients.

  13. Comparison of two flow-based imaging methods to measure individual red blood cell area and volume.

    Science.gov (United States)

    Tomaiuolo, Giovanna; Rossi, Domenico; Caserta, Sergio; Cesarelli, Mario; Guido, Stefano

    2012-12-01

    The red blood cells (RBCs) population is characterized by a high heterogeneity in membrane area, cellular volume, and mechanical properties, mainly due to the variety of mechanical and chemical stresses that a red cell undergoes in its entire life span. Here, we provide the first simultaneous area and volume measurements of RBCs flowing in microcapillaries, by using high-speed video microscopy imaging and quantitative data processing based on image analysis techniques. Both confined and unbounded flow conditions (depending on the relative size of RBCs and microcapillary diameter) are investigated. The results are compared with micropipette experiments from the literature and data from Coulter counter routine clinical blood tests. Good agreement is found for RBC volume, especially in the case of confined flow conditions. Surface area measurements, which are lacking in the routine clinical test, are of special interest being a potential diagnostic parameter of altered cell deformability and aggregability. Overall, our results provide a novel flow methodology suitable for high-throughput measurements of RBC geometrical parameters, allowing one to overcome the limits of classical static methods, such as micropipette aspiration, which are not suitable for handling a large number of cells.

  14. Trans-illuminated laser speckle imaging of collateral artery blood flow in ischemic mouse hindlimb

    OpenAIRE

    Meisner, Joshua K.; Niu, Jacqueline; Sumer, Suna; Price, Richard J.

    2013-01-01

    Abstract. The mouse ischemic hindlimb model is used widely for studying collateral artery growth (i.e., arteriogenesis) in response to increased shear stress. Nonetheless, precise measurements of regional shear stress changes along individual collateral arteries are lacking. Our goal is to develop and verify trans-illumination laser speckle flowmetry (LSF) for this purpose. Studies of defibrinated bovine blood flow through tubes embedded in tissue-mimicking phantoms indicate that trans-illumi...

  15. Pooling Ideas on Art and Imaging.

    Science.gov (United States)

    Nicholls, David

    Art works created with conventional materials reflect the hand of the artist. Artists with physical disabilities such as muscular spasms, weakness, or limitations of mobility impedes efforts to produce works of art. An experimental program uses computers to introduce art curricula into two British schools: (1) Thurlow Park (a school for children…

  16. Analyzing the blood-brain barrier: the benefits of medical imaging in research and clinical practice.

    Science.gov (United States)

    Chassidim, Yoash; Vazana, Udi; Prager, Ofer; Veksler, Ronel; Bar-Klein, Guy; Schoknecht, Karl; Fassler, Michael; Lublinsky, Svetlana; Shelef, Ilan

    2015-02-01

    A dysfunctional BBB is a common feature in a variety of brain disorders, a fact stressing the need for diagnostic tools designed to assess brain vessels' permeability in space and time. Biological research has benefited over the years various means to analyze BBB integrity. The use of biomarkers for improper BBB functionality is abundant. Systemic administration of BBB impermeable tracers can both visualize brain regions characterized by BBB impairment, as well as lead to its quantification. Additionally, locating molecular, physiological content in regions from which it is restricted under normal BBB functionality undoubtedly indicates brain pathology-related BBB disruption. However, in-depth research into the BBB's phenotype demands higher analytical complexity than functional vs. pathological BBB; criteria which biomarker based BBB permeability analyses do not meet. The involvement of accurate and engineering sciences in recent brain research, has led to improvements in the field, in the form of more accurate, sensitive imaging-based methods. Improvements in the spatiotemporal resolution of many imaging modalities and in image processing techniques, make up for the inadequacies of biomarker based analyses. In pre-clinical research, imaging approaches involving invasive procedures, enable microscopic evaluation of BBB integrity, and benefit high levels of sensitivity and accuracy. However, invasive techniques may alter normal physiological function, thus generating a modality-based impact on vessel's permeability, which needs to be corrected for. Non-invasive approaches do not affect proper functionality of the inspected system, but lack in spatiotemporal resolution. Nevertheless, the benefit of medical imaging, even in pre-clinical phases, outweighs its disadvantages. The innovations in pre-clinical imaging and the development of novel processing techniques, have led to their implementation in clinical use as well. Specialized analyses of vessels' permeability

  17. Effects of permanent magnets on resting skin blood perfusion in healthy persons assessed by laser Doppler flowmetry and imaging.

    Science.gov (United States)

    Mayrovitz, H N; Groseclose, E E; Markov, M; Pilla, A A

    2001-10-01

    Effects on skin blood perfusion of permanent ceramic magnets [0.1 T (1000 G) surface field], individually (disk shaped, 4 cm diameter x 1 cm thick) or in the form of a 11 x 7 in pad ( approximately 28 x 17.8 cm) with an array of 16 rectangular magnets (4.5 x 2.2 cm), were investigated in 16 female volunteers (27.4 +/- 1.7 years, range 21-48 years) using three separate protocols. In protocol A, a disk magnet was placed on the palmar surface of the hand in contact with the thenar eminence (n = 5). In protocol B, the magnet was placed on the hand dorsum overlying the thenar eminence (n = 5). In protocol C, the entire palm and fingers rested on the magnetic pad (n = 6). Magnets were in place for 36 min on one hand, and a sham was in place on the other hand. Blood perfusion was measured on the middle finger dorsum by laser Doppler flowmetry (LDF) and on the index finger by laser Doppler imaging (LDI). Perfusion measurements were simultaneously taken in sham and magnet exposed hands, before and during the entire magnet exposure interval. Magnetic field effects were tested by comparing skin blood perfusion sequences in magnet and sham exposed regions. Results showed no significant changes in either LDF or LDI perfusion at magnet or sham sites during exposure, nor were there any significant differences between sham and magnet sites for any protocol. Measurements of skin temperature at the LDF measurement sites also showed no significant change. It is concluded that in the healthy subjects studied with normal, unstressed circulation, magnets of the type and for the duration used, showed no detectible effect on skin blood perfusion in the anatomical area studied.

  18. [(18)F](2S,4R)4-Fluoroglutamine PET Detects Glutamine Pool Size Changes in Triple-Negative Breast Cancer in Response to Glutaminase Inhibition.

    Science.gov (United States)

    Zhou, Rong; Pantel, Austin R; Li, Shihong; Lieberman, Brian P; Ploessl, Karl; Choi, Hoon; Blankemeyer, Eric; Lee, Hsiaoju; Kung, Hank F; Mach, Robert H; Mankoff, David A

    2017-03-15

    Glutaminolysis is a metabolic pathway adapted by many aggressive cancers, including triple-negative breast cancers (TNBC), to utilize glutamine for survival and growth. In this study, we examined the utility of [(18)F](2S,4R)4-fluoroglutamine ([(18)F]4F-Gln) PET to measure tumor cellular glutamine pool size, whose change might reveal the pharmacodynamic (PD) effect of drugs targeting this cancer-specific metabolic pathway. High glutaminase (GLS) activity in TNBC tumors resulted in low cellular glutamine pool size assayed via high-resolution (1)H magnetic resonance spectroscopy (MRS). GLS inhibition significantly increased glutamine pool size in TNBC tumors. MCF-7 tumors, with inherently low GLS activity compared with TNBC, displayed a larger baseline glutamine pool size that did not change as much in response to GLS inhibition. The tumor-to-blood-activity ratios (T/B) obtained from [(18)F]4F-Gln PET images matched the distinct glutamine pool sizes of both tumor models at baseline. After a short course of GLS inhibitor treatment, the T/B values increased significantly in TNBC, but did not change in MCF-7 tumors. Across both tumor types and after GLS inhibitor or vehicle treatment, we observed a strong positive correlation between T/B values and tumor glutamine pool size measured using MRS (r(2) = 0.71). In conclusion, [(18)F]4F-Gln PET tracked cellular glutamine pool size in breast cancers with differential GLS activity and detected increases in cellular glutamine pool size induced by GLS inhibitors. This study accomplished the first necessary step toward validating [(18)F]4F-Gln PET as a PD marker for GLS-targeting drugs. Cancer Res; 77(6); 1476-84. ©2017 AACR.

  19. Added value of lung perfused blood volume images using dual-energy CT for assessment of acute pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Kunihiro, Yoshie [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru [Department of Radiology, Yamaguchi Grand Medical Center, Oosaki 77, Hofu, Yamaguchi 747-8511 (Japan); Nomura, Takafumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Kudomi, Shohei; Yonezawa, Teppei [Department of Radiology, Yamaguchi University Hospital, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Suga, Kazuyoshi [Department of Radiology, St. Hills Hospital, Imamurakita 3-7-18, Ube, Yamaguchi 755-0155 (Japan); Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan)

    2015-01-15

    Purpose: To investigate the added value of lung perfused blood volume (LPBV) using dual-energy CT for the evaluation of intrapulmonary clot (IPC) in patients suspected of having acute pulmonary embolism (PE). Materials and methods: Institutional review board approval was obtained for this retrospective study. Eighty-three patients suspected of having PE who underwent CT pulmonary angiography (CTPA) using a dual-energy technique were enrolled in this study. Two radiologists who were blinded retrospectively and independently reviewed CTPA images alone and the combined images with color-coded LPBV over a 4-week interval, and two separate sessions were performed with a one-month interval. Inter- and intraobserver variability and diagnostic accuracy were evaluated for each reviewer with receiver operating characteristic (ROC) curve analysis. Results: Values for inter- and intraobserver agreement, respectively, were better for CTPA combined with LPBV (ICC = 0.847 and 0.937) than CTPA alone (ICC = 0.748 and 0.861). For both readers, diagnostic accuracy (area under the ROC curve [A{sub z}]) were also superior, when CTPA alone (A{sub z} = 0.888 [reader 1] and 0.912 [reader 2]) was compared with that after the combination with LPBV images (A{sub z} = 0.966 [reader 1] and 0.959 [reader 2]) (p < 0.001). However, A{sub z} values of both images might not have significant difference in statistics, because A{sub z} value of CTPA alone was high and 95% confidence intervals overlapped in both images. Conclusion: Addition of dual-energy perfusion CT to CTPA improves detection of peripheral IPCs with better interobserver agreement.

  20. Validation of Blood Volume Fraction Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Porcine Skeletal Muscle

    Science.gov (United States)

    Söhner, Anika; Maaß, Marc; Sauerwein, Wolfgang; Möllmann, Dorothe; Baba, Hideo Andreas; Kramer, Martin; Lüdemann, Lutz

    2017-01-01

    The purpose of this study was to assess the accuracy of fractional blood volume (vb) estimates in low-perfused and low-vascularized tissue using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The results of different MRI methods were compared with histology to evaluate the accuracy of these methods under clinical conditions. vb was estimated by DCE-MRI using a 3D gradient echo sequence with k-space undersampling in five muscle groups in the hind leg of 9 female pigs. Two gadolinium-based contrast agents (CA) were used: a rapidly extravasating, extracellular, gadolinium-based, low-molecular-weight contrast agent (LMCA, gadoterate meglumine) and an extracellular, gadolinium-based, albumin-binding, slowly extravasating blood pool contrast agent (BPCA, gadofosveset trisodium). LMCA data were evaluated using the extended Tofts model (ETM) and the two-compartment exchange model (2CXM). The images acquired with administration of the BPCA were used to evaluate the accuracy of vb estimation with a bolus deconvolution technique (BD) and a method we call equilibrium MRI (EqMRI). The latter calculates the ratio of the magnitude of the relaxation rate change in the tissue curve at an approximate equilibrium state to the height of the same area of the arterial input function (AIF). Immunohistochemical staining with isolectin was used to label endothelium. A light microscope was used to estimate the fractional vascular area by relating the vascular region to the total tissue region (immunohistochemical vessel staining, IHVS). In addition, the percentage fraction of vascular volume was determined by multiplying the microvascular density (MVD) with the average estimated capillary lumen, π(d2)2, where d = 8μm is the assumed capillary diameter (microvascular density estimation, MVDE). Except for ETM values, highly significant correlations were found between most of the MRI methods investigated. In the cranial thigh, for example, the vb medians (interquartile range

  1. Human parvovirus PARV4 in plasma pools of Chinese origin.

    Science.gov (United States)

    Ma, Y-Y; Guo, Y; Zhao, X; Wang, Z; Lv, M-M; Yan, Q-P; Zhang, J-G

    2012-10-01

    Human parvovirus 4 (PARV4) is present in blood and blood products. As the presence and levels of PARV4 in Chinese source plasma pools have never been determined, we implemented real-time quantitative PCR to investigate the presence of PARV4 in source plasma pools in China. Results showed that 26·15% (51/195) of lots tested positive for PARV4. The amounts of DNA ranged from 2·83 × 10(3) copies/ml to 2·35×10(7) copies/ml plasma. The high level of PARV4 in plasma pools may pose a potential risk to recipients. Further studies on the pathogenesis of PARV4 are urgently required.

  2. Accurate segmentation of leukocyte in blood cell images using Atanassov's intuitionistic fuzzy and interval Type II fuzzy set theory.

    Science.gov (United States)

    Chaira, Tamalika

    2014-06-01

    In this paper automatic leukocyte segmentation in pathological blood cell images is proposed using intuitionistic fuzzy and interval Type II fuzzy set theory. This is done to count different types of leukocytes for disease detection. Also, the segmentation should be accurate so that the shape of the leukocytes is preserved. So, intuitionistic fuzzy set and interval Type II fuzzy set that consider either more number of uncertainties or a different type of uncertainty as compared to fuzzy set theory are used in this work. As the images are considered fuzzy due to imprecise gray levels, advanced fuzzy set theories may be expected to give better result. A modified Cauchy distribution is used to find the membership function. In intuitionistic fuzzy method, non-membership values are obtained using Yager's intuitionistic fuzzy generator. Optimal threshold is obtained by minimizing intuitionistic fuzzy divergence. In interval type II fuzzy set, a new membership function is generated that takes into account the two levels in Type II fuzzy set using probabilistic T co norm. Optimal threshold is selected by minimizing a proposed Type II fuzzy divergence. Though fuzzy techniques were applied earlier but these methods failed to threshold multiple leukocytes in images. Experimental results show that both interval Type II fuzzy and intuitionistic fuzzy methods perform better than the existing non-fuzzy/fuzzy methods but interval Type II fuzzy thresholding method performs little bit better than intuitionistic fuzzy method. Segmented leukocytes in the proposed interval Type II fuzzy method are observed to be distinct and clear.

  3. The effect of whitening transformation on pooling operations in convolutional autoencoders

    Science.gov (United States)

    Li, Zuhe; Fan, Yangyu; Liu, Weihua

    2015-12-01

    Convolutional autoencoders (CAEs) are unsupervised feature extractors for high-resolution images. In the pre-processing step, whitening transformation has widely been adopted to remove redundancy by making adjacent pixels less correlated. Pooling is a biologically inspired operation to reduce the resolution of feature maps and achieve spatial invariance in convolutional neural networks. Conventionally, pooling methods are mainly determined empirically in most previous work. Therefore, our main purpose is to study the relationship between whitening processing and pooling operations in convolutional autoencoders for image classification. We propose an adaptive pooling approach based on the concepts of information entropy to test the effect of whitening on pooling in different conditions. Experimental results on benchmark datasets indicate that the performance of pooling strategies is associated with the distribution of feature activations, which can be affected by whitening processing. This provides guidance for the selection of pooling methods in convolutional autoencoders and other convolutional neural networks.

  4. Rank Pooling for Action Recognition.

    Science.gov (United States)

    Fernando, Basura; Gavves, Efstratios; Oramas M, Jose Oramas; Ghodrati, Amir; Tuytelaars, Tinne

    2017-04-01

    We propose a function-based temporal pooling method that captures the latent structure of the video sequence data - e.g., how frame-level features evolve over time in a video. We show how the parameters of a function that has been fit to the video data can serve as a robust new video representation. As a specific example, we learn a pooling function via ranking machines. By learning to rank the frame-level features of a video in chronological order, we obtain a new representation that captures the video-wide temporal dynamics of a video, suitable for action recognition. Other than ranking functions, we explore different parametric models that could also explain the temporal changes in videos. The proposed functional pooling methods, and rank pooling in particular, is easy to interpret and implement, fast to compute and effective in recognizing a wide variety of actions. We evaluate our method on various benchmarks for generic action, fine-grained action and gesture recognition. Results show that rank pooling brings an absolute improvement of 7-10 average pooling baseline. At the same time, rank pooling is compatible with and complementary to several appearance and local motion based methods and features, such as improved trajectories and deep learning features.

  5. Phase-resolved functional optical coherence tomography: simultaneous imaging of in situ tissue structure, blood flow velocity, standard deviation, birefringence, and Stokes vectors in human skin

    Science.gov (United States)

    Ren, Hongwu; Ding, Zhihua; Zhao, Yonghua; Miao, Jianjun; Nelson, J. Stuart; Chen, Zhongping

    2002-10-01

    We describe a phase-resolved functional optical coherence tomography system that can simultaneously yield in situ images of tissue structure, blood flow velocity, standard deviation, birefringence, and the Stokes vectors in human skin. Multifunctional images were obtained by processing of analytical interference fringe signals derived from two perpendicular polarization-detection channels. The blood flow velocity and standard deviation images were obtained by comparison of the phases from pairs of analytical signals in neighboring A-lines in the same polarization state. The analytical signals from two polarization-diversity detection channels were used to determine the four Stokes vectors for four reference polarization states. From the four Stokes vectors, the birefringence image, which is not sensitive to the orientation of the optical axis in the sample, was obtained. Multifunctional in situ images of a port wine stain birthmark in human skin are presented.

  6. Image-Based Modeling of Blood Flow and Oxygen Transfer in Feto-Placental Capillaries

    Science.gov (United States)

    Brownbill, Paul; Janáček, Jiří; Jirkovská, Marie; Kubínová, Lucie; Chernyavsky, Igor L.; Jensen, Oliver E.

    2016-01-01

    During pregnancy, oxygen diffuses from maternal to fetal blood through villous trees in the placenta. In this paper, we simulate blood flow and oxygen transfer in feto-placental capillaries by converting three-dimensional representations of villous and capillary surfaces, reconstructed from confocal laser scanning microscopy, to finite-element meshes, and calculating values of vascular flow resistance and total oxygen transfer. The relationship between the total oxygen transfer rate and the pressure drop through the capillary is shown to be captured across a wide range of pressure drops by physical scaling laws and an upper bound on the oxygen transfer rate. A regression equation is introduced that can be used to estimate the oxygen transfer in a capillary using the vascular resistance. Two techniques for quantifying the effects of statistical variability, experimental uncertainty and pathological placental structure on the calculated properties are then introduced. First, scaling arguments are used to quantify the sensitivity of the model to uncertainties in the geometry and the parameters. Second, the effects of localized dilations in fetal capillaries are investigated using an idealized axisymmetric model, to quantify the possible effect of pathological placental structure on oxygen transfer. The model predicts how, for a fixed pressure drop through a capillary, oxygen transfer is maximized by an optimal width of the dilation. The results could explain the prevalence of fetal hypoxia in cases of delayed villous maturation, a pathology characterized by a lack of the vasculo-syncytial membranes often seen in conjunction with localized capillary dilations. PMID:27788214

  7. Characteristic prefrontal blood volume patterns when imaging body type, high-calorie food, and mother-child attachment in childhood anorexia nervosa: A near infrared spectroscopy study.

    Science.gov (United States)

    Nagamitsu, Shinichiro; Yamashita, Fumiko; Araki, Yuko; Iizuka, Chiho; Ozono, Shuichi; Komatsu, Hiroko; Ohya, Takashi; Yamashita, Yushiro; Kakuma, Tatsuyuki; Tsuda, Akira; Matsuishi, Toyojiro

    2010-02-01

    The aim of this study was to investigate the prefrontal activation in childhood anorexia nervosa (AN) patients when imaging symptom-provocative factors such as body type, high-calorie food, and attachment between mother and child. The prefrontal activations during each task, in terms of blood volume changes, were measured by near infrared spectroscopy. Twelve females with childhood AN (mean age, 14.4 years old) and 13 age-matched healthy female controls (mean age, 14.3 years old) participated in this study. Both groups showed increased prefrontal blood volume when viewing images of each symptom-provocative factor. Unexpectedly, there was no significant difference in the prefrontal blood volume increases between the control group and the childhood AN group when viewing images of slender and obese body types and high-calorie food. On the other hand, images of mother-child attachment resulted in significantly greater increases in prefrontal blood volume in the childhood AN group than in the control group. These results indicated that prefrontal activation in AN might be associated with imaging attachment between mother and child, but not associated with imaging body type or high-calorie food.

  8. Blood Types

    Science.gov (United States)

    ... maternity. Learn About Blood Blood Facts and Statistics Blood Components Whole Blood and Red Blood Cells Platelets Plasma ... About Blood Blood Facts and Statistics Blood Types Blood Components What Happens to Donated Blood Blood and Diversity ...

  9. Label free imaging system for measuring blood flow speeds using a single multi-mode optical fiber (Conference Presentation)

    Science.gov (United States)

    Sigal, Iliya; Caravaca Aguirre, Antonio M.; Gad, Raanan; Piestun, Rafael; Levi, Ofer

    2016-03-01

    We demonstrate a single multi-mode fiber-based micro-endoscope for measuring blood flow speeds. We use the transmission-matrix wavefront shaping approach to calibrate the multi-mode fiber and raster-scan a focal spot across the distal fiber facet, imaging the cross-polarized back-reflected light at the proximal facet using a camera. This setup allows assessment of the backscattered photon statistics: by computing the mean speckle contrast values across the proximal fiber facet we show that spatially-resolved flow speed maps can be inferred by selecting an appropriate camera integration time. The proposed system is promising for minimally-invasive studies of neurovascular coupling in deep brain structures.

  10. A new method to study changes in microvascular blood volume in muscle and adipose tissue: Real time imaging in humans and rat

    DEFF Research Database (Denmark)

    Sjøberg, Kim Anker; Rattigan, Stephen; Hiscock, Natalie J;

    2011-01-01

    We employed and evaluated a new application of contrast enhanced ultrasound for real time imaging of changes in microvascular blood volume (MVB) in tissues in females, males and rat. Continuous real time imaging was performed using contrast enhanced ultrasound to quantify infused gas filled...... have demonstrated that real time imaging of changes in MBV is possible in human and rat muscle and in subcutaneous adipose tissue and that the method is sensitive enough to pick up relatively small changes in MBV when performed with due consideration of steady state microbubble concentration. Due...... to real time imaging the method has wide applications for determining MBV in different organs during various physiological or pathophysiological conditions....

  11. Spatial Pyramid Pooling in Deep Convolutional Networks for Visual Recognition.

    Science.gov (United States)

    He, Kaiming; Zhang, Xiangyu; Ren, Shaoqing; Sun, Jian

    2015-09-01

    Existing deep convolutional neural networks (CNNs) require a fixed-size (e.g., 224 × 224) input image. This requirement is "artificial" and may reduce the recognition accuracy for the images or sub-images of an arbitrary size/scale. In this work, we equip the networks with another pooling strategy, "spatial pyramid pooling", to eliminate the above requirement. The new network structure, called SPP-net, can generate a fixed-length representation regardless of image size/scale. Pyramid pooling is also robust to object deformations. With these advantages, SPP-net should in general improve all CNN-based image classification methods. On the ImageNet 2012 dataset, we demonstrate that SPP-net boosts the accuracy of a variety of CNN architectures despite their different designs. On the Pascal VOC 2007 and Caltech101 datasets, SPP-net achieves state-of-the-art classification results using a single full-image representation and no fine-tuning. The power of SPP-net is also significant in object detection. Using SPP-net, we compute the feature maps from the entire image only once, and then pool features in arbitrary regions (sub-images) to generate fixed-length representations for training the detectors. This method avoids repeatedly computing the convolutional features. In processing test images, our method is 24-102 × faster than the R-CNN method, while achieving better or comparable accuracy on Pascal VOC 2007. In ImageNet Large Scale Visual Recognition Challenge (ILSVRC) 2014, our methods rank #2 in object detection and #3 in image classification among all 38 teams. This manuscript also introduces the improvement made for this competition.

  12. Autoradiographic imaging of cerebral ischaemia using a combination of blood flow and hypoxic markers in an animal model

    Energy Technology Data Exchange (ETDEWEB)

    Lythgoe, M.F. [Royal College of Surgeons Unit of Biophysics, Institute of Child Health, London (United Kingdom)]|[Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom); Williams, S.R. [Royal College of Surgeons Unit of Biophysics, Institute of Child Health, London (United Kingdom); Wiebe, L.I. [University of Alberta, Edmonton, AB (Canada); McEwan, A.J.B. [University of Alberta, Edmonton, AB (Canada); Gordon, I. [Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom)

    1997-01-01

    Current routine clinical techniques, including angiography and perfusional single-photon emission tomography, can be used to indicate problems in cerebral vascular supply and areas of cerebral hypoperfusion following a stroke, but cannot distinguish between ischaemic core and penumbra. In order to image specifically the penumbra, a method or indicator should be able to define areas with reduced blood flow, and a degree of metabolic compromise. In this context, the tissue could be regarded as hypoxic rather than ischaemic, and we have therefore chosen to investigate the potential of radio-labelled hypoxic markers in the study of ischaemia. In order to combine a hypoxic marker with a blood flow marker we used technetium-99m hexamethylpropylene amine oxime ({sup 99m}Tc-HMPAO) and iodine-125 iodoazomycin arabinoside ({sup 125}I-IAZA), during cerebral ischaemia in the rat middle cerebral artery occlusion model. {sup 99m}Tc-HMPAO and {sup 125}I-IAZA were injected simultaneously 2 h following occlusion of the middle cerebral artery, and 5 h before decapitation. Paired autoradiograms were produced and compared. Three distinct patterns emerged from the autoradiograms: slightly decreased perfusion with no uptake of the hypoxic marker indicating an area of misery perfusion; moderately decreased perfusion with concomitant uptake of iodoazomycin arabinoside, a region of hypoxia; and severely decreased perfusion with no retention of the hypoxic tracer. In conclusion, we present a new use for an imaging agent in the investigation of cerebral hypoxia. This agent, IAZA together with HMPAO, provides a means of separating the penumbra into regions of misery perfusion and hypoxia. The potential impact of this may be important in the clinical investigation of stroke. (orig.). With 3 figs.

  13. Three-dimensional whole-brain perfused blood volume imaging with multimodal CT for evaluation of acute ischaemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Lu, J.; Zhang, M.; Cao, Y. [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing (China); Ma, Q. [Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing (China); Chen, J. [Healthcare, Siemens Ltd. China, Beijing (China); Ji, X. [Department of Neurosurgery Xuanwu Hospital, Capital Medical University, Beijing (China); Li, K., E-mail: imaging@yeah.ne [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing (China)

    2011-06-15

    Aim: To determine the diagnostic value of integrating three-dimensional perfused blood volume (3D PBV) with multimodal computed tomography (CT) [non-enhanced CT (NECT), CT perfusion (CTP), and CT angiography (CTA)] in acute ischaemic stroke. Materials and methods: NECT, CTP, and CTA were performed in 25 acute ischaemic stroke patients. The ischaemia detection rate of 3D PBV was compared with the results of baseline NECT and CTP. The correlation of ischaemic lesion volume between 3D PBV, CTP images, and follow-up NECT were analysed. Results: NECT demonstrated ischaemic signs in 12 of 25 patients with proven infarction. CTP maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and time to peak (TTP) all demonstrated perfusion deficits in 21 of 25 patients. However, 3D PBV demonstrated perfusion deficits in all of the 25 patients. Among the 25 patients, a strong correlation was found between PBV and the follow-up NECT infarct (r = 0.858). The correlation between CTP and the follow-up NECT infarct as following: CBF (r = 0.718), CBV (r = 0.785), and TTP (r = 0.569). In 14 thrombolytic patients, strong correlation was found between the ischaemic volume on 3D PBV and follow-up NECT (r = 0.798). Conclusion: In acute stroke patients, the combination of 3D PBV and multimodal CT (NECT, CTP, and CTA) can improve the detection rate of ischaemia and enable assessment of the full extent of ischaemia, which correlates well with follow-up NECT.

  14. Investigation of Hepatic Blood Perfusion by Laser Speckle Imaging and Changes of Hepatic Vasoactive Substances in Mice after Electroacupuncture

    Directory of Open Access Journals (Sweden)

    Xiao-jing Song

    2014-01-01

    Full Text Available The study was conducted to observe the effect of electroacupuncture (EA on hepatic blood perfusion (HBP and vascular regulation. We investigated 60 male anesthetized mice under the following 3 conditions: without EA stimulation (control group; EA stimulation at Zusanli (ST36 group; EA stimulation at nonacupoint (NA group during 30 min. The HBP was measured using the laser speckle perfusion imaging (LSPI. The level of nitric oxide (NO, endothelin-1 (ET-1, and noradrenaline (NE in liver tissue was detected by biochemical methods. Results were as follows. At each time point, HBP increase in ST36 group was higher than that in the NA group in anesthetized mice. HBP gradually decreased during 30 min in control group. The level of NO in ST36 group was higher than that in NA group. The level of both ET-1 and NE was the highest in control group, followed by NA group and ST36 group. It is concluded that EA at ST36 could increase HBP possibly by increasing the blood flow velocity (BFV, changing vascular activity, increasing the level of NO, and inhibiting the level of ET-1 in liver tissue.

  15. Investigation of hepatic blood perfusion by laser speckle imaging and changes of hepatic vasoactive substances in mice after electroacupuncture.

    Science.gov (United States)

    Song, Xiao-Jing; Zhang, Dong; Wang, Shu-You; Li, Shun-Yue

    2014-01-01

    The study was conducted to observe the effect of electroacupuncture (EA) on hepatic blood perfusion (HBP) and vascular regulation. We investigated 60 male anesthetized mice under the following 3 conditions: without EA stimulation (control group); EA stimulation at Zusanli (ST36 group); EA stimulation at nonacupoint (NA group) during 30 min. The HBP was measured using the laser speckle perfusion imaging (LSPI). The level of nitric oxide (NO), endothelin-1 (ET-1), and noradrenaline (NE) in liver tissue was detected by biochemical methods. Results were as follows. At each time point, HBP increase in ST36 group was higher than that in the NA group in anesthetized mice. HBP gradually decreased during 30 min in control group. The level of NO in ST36 group was higher than that in NA group. The level of both ET-1 and NE was the highest in control group, followed by NA group and ST36 group. It is concluded that EA at ST36 could increase HBP possibly by increasing the blood flow velocity (BFV), changing vascular activity, increasing the level of NO, and inhibiting the level of ET-1 in liver tissue.

  16. Grundfoss: Chlorination of Swimming Pools

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Hogan, John; Andreassen, Viggo

    1998-01-01

    Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools.......Grundfos asked for a model, describing the problem of mixing chemicals, being dosed into water systems, to be developed. The application of the model should be dedicated to dosing aqueous solution of chlorine into swimming pools....

  17. Double-echo perfusion-weighted MR imaging: basic concepts and application in brain tumors for the assessment of tumor blood volume and vascular permeability

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, Hidemasa [University of Fukui, Department of Radiology, Faculty of Medical Sciences, Fukui (Japan); Maeda, Masayuki [Mie University School of Medicine, Department of Radiology, Mie (Japan)

    2006-01-01

    Perfusion-weighted magnetic resonance (MR) imaging using contrast agents plays a key role in characterizing tumors of the brain. We have shown that double-echo perfusion-weighted MR imaging (DEPWI) is potentially useful in assessing brain tumors. Quantitative indices, such as tumor blood volume, are obtained using DEPWI, which allows correction of underestimation of tumor blood volume due to leakage of contrast agents from tumor vessels, in addition to simultaneous acquisition of tumor vessel permeability. This article describes basic concepts of DEPWI and demonstrates clinical applications in brain tumors. (orig.)

  18. Comparison of cerebral blood flow measurement with [15O]-water positron emission tomography and arterial spin labeling magnetic resonance imaging: A systematic review.

    Science.gov (United States)

    Fan, Audrey P; Jahanian, Hesamoddin; Holdsworth, Samantha J; Zaharchuk, Greg

    2016-05-01

    Noninvasive imaging of cerebral blood flow provides critical information to understand normal brain physiology as well as to identify and manage patients with neurological disorders. To date, the reference standard for cerebral blood flow measurements is considered to be positron emission tomography using injection of the [(15)O]-water radiotracer. Although [(15)O]-water has been used to study brain perfusion under normal and pathological conditions, it is not widely used in clinical settings due to the need for an on-site cyclotron, the invasive nature of arterial blood sampling, and experimental complexity. As an alternative, arterial spin labeling is a promising magnetic resonance imaging technique that magnetically labels arterial blood as it flows into the brain to map cerebral blood flow. As arterial spin labeling becomes more widely adopted in research and clinical settings, efforts have sought to standardize the method and validate its cerebral blood flow values against positron emission tomography-based cerebral blood flow measurements. The purpose of this work is to critically review studies that performed both [(15)O]-water positron emission tomography and arterial spin labeling to measure brain perfusion, with the aim of better understanding the accuracy and reproducibility of arterial spin labeling relative to the positron emission tomography reference standard.

  19. 13 CFR 120.1706 - Pool Originator's retained interest in Pool.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Pool Originator's retained interest in Pool. 120.1706 Section 120.1706 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION... Pools § 120.1706 Pool Originator's retained interest in Pool. The Pool Originator must retain...

  20. Quantitative versus semiquantitative MR imaging of cartilage in blood-induced arthritic ankles: preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Doria, Andrea S. [The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto, ON (Canada); University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); Zhang, Ningning [Children' s Hospital, Department of Radiology, Beijing (China); Lundin, Bjorn [Skaane University Hospital and Lund University, University Hospital of Lund, Center for Medical Imaging and Physiology, Lund (Sweden); Hilliard, Pamela [The Hospital for Sick Children, Department of Rehabilitation Services, Toronto, ON (Canada); Man, Carina; Weiss, Ruth; Detzler, Garry [The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto, ON (Canada); Blanchette, Victor [The Hospital for Sick Children, Department of Hematology, Toronto, ON (Canada); Moineddin, Rahim [Family and Community Medicine, Department of Public Health, Toronto, ON (Canada); Eckstein, Felix [Paracelsus Medical University, Institute of Anatomy and Musculoskeletal Research, Salzburg (Austria); Chondrometrics GmbH, Ainring (Germany); Sussman, Marshall S. [University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); University Health Network, Department of Medical Imaging, Toronto, ON (Canada)

    2014-05-15

    Recent advances in hemophilia prophylaxis have raised the need for accurate noninvasive methods for assessment of early cartilage damage in maturing joints to guide initiation of prophylaxis. Such methods can either be semiquantitative or quantitative. Whereas semiquantitative scores are less time-consuming to be performed than quantitative methods, they are prone to subjective interpretation. To test the feasibility of a manual segmentation and a quantitative methodology for cross-sectional evaluation of articular cartilage status in growing ankles of children with blood-induced arthritis, as compared with a semiquantitative scoring system and clinical-radiographic constructs. Twelve boys, 11 with hemophilia (A, n = 9; B, n = 2) and 1 with von Willebrand disease (median age: 13; range: 6-17), underwent physical examination and MRI at 1.5 T. Two radiologists semiquantitatively scored the MRIs for cartilage pathology (surface erosions, cartilage loss) with blinding to clinical information. An experienced operator applied a validated quantitative 3-D MRI method to determine the percentage area of denuded bone (dAB) and the cartilage thickness (ThCtAB) in the joints' MRIs. Quantitative and semiquantitative MRI methods and clinical-radiographic constructs (Hemophilia Joint Health Score [HJHS], Pettersson radiograph scores) were compared. Moderate correlations were noted between erosions and dAB (r = 0.62, P = 0.03) in the talus but not in the distal tibia (P > 0.05). Whereas substantial to high correlations (r range: 0.70-0.94, P < 0.05) were observed between erosions, cartilage loss, HJHS and Pettersson scores both at the distal tibia and talus levels, moderate/borderline substantial (r range: 0.55-0.61, P < 0.05) correlations were noted between dAB/ThCtAB and clinical-radiographic constructs. Whereas the semiquantitative method of assessing cartilage status is closely associated with clinical-radiographic scores in cross-sectional studies of blood

  1. Myocardial blood flow assessment with {sup 82}rubidium-PET imaging in patients with left bundle branch block

    Energy Technology Data Exchange (ETDEWEB)

    Falcao, Andrea; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares Junior, Jose; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Kalil Filho, Roberto; Meneghetti, Jose C., E-mail: andrea.falcao@incor.usp.br [Universidade de Sao Paulo (InCor/USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Instituto do Coracao

    2015-11-15

    Objectives: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. Objective: we sought to investigate rubidium-82 ({sup 82}Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. Methods: thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress {sup 82}Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal {sup 82}Rb-positron emission tomography studies and without left bundle branch block (GII). Results: stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p>0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). Conclusion: the data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by {sup 82}Rb-positron emission tomography imaging may be useful in identifying coronary artery

  2. Enhanced visuomotor processing of phobic images in blood-injury-injection fear.

    Science.gov (United States)

    Haberkamp, Anke; Schmidt, Thomas

    2014-04-01

    Numerous studies have identified attentional biases and processing enhancements for fear-relevant stimuli in individuals with specific phobias. However, this has not been conclusively shown in blood-injury-injection (BII) phobia, which has rarely been investigated even though it has features distinct from all other specific phobias. The present study aims to fill that gap and compares the time-course of visuomotor processing of phobic stimuli (i.e., pictures of small injuries) in BII-fearful (n=19) and non-anxious control participants (n=23) by using a response priming paradigm. In BII-fearful participants, phobic stimuli produced larger priming effects and lower response times compared to neutral stimuli, whereas non-anxious control participants showed no such differences. Because these effects are fully present in the fastest responses, they indicate an enhancement in early visuomotor processing of injury pictures in BII-fearful participants. These results are comparable to the enhanced processing of phobic stimuli in other specific phobias (i.e., spider phobia).

  3. A dual functional fluorescent probe for glioma imaging mediated by blood-brain barrier penetration and glioma cell targeting.

    Science.gov (United States)

    Ma, Hongwei; Gao, Zhiyong; Yu, Panfeng; Shen, Shun; Liu, Yongmei; Xu, Bainan

    2014-06-20

    Glioma is a huge threat for human being because it was hard to be completely removed owing to both the infiltrating growth of glioma cells and integrity of blood brain barrier. Thus effectively imaging the glioma cells may pave a way for surgical removing of glioma. In this study, a fluorescent probe, Cy3, was anchored onto the terminal of AS1411, a glioma cell targeting aptamer, and then TGN, a BBB targeting peptide, was conjugated with Cy3-AS1411 through a PEG linker. The production, named AsT, was characterized by gel electrophoresis, (1)H NMR and FTIR. In vitro cellular uptake and glioma spheroid uptake demonstrated the AsT could not only be uptaken by both glioma and endothelial cells, but also penetrate through endothelial cell monolayer and uptake by glioma spheroids. In vivo, AsT could effectively target to glioma with high intensity. In conclusion, AsT could be used as an effective glioma imaging probe.

  4. Comparison of cerebral blood volume and permeability in preoperative grading of intracranial glioma using CT perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Bei; Ling, Hua Wei; Chen, Ke Min [Shanghai Jiaotong University, Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai (China); Jiang, Hong [Shanghai Jiaotong University, Department of Pathology, Ruijin Hospital, School of Medicine, Shanghai (China); Zhu, Yan Bo [Shanghai Jiaotong University, Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai (China)

    2006-10-15

    Regional cerebral blood volume (rCBV) and permeability surfaces (rPS) permit in vivo assessment of glioma microvasculature, which provides quite important pathophysiological information in grading gliomas. The aim of our study was to simultaneously examine rCBV and rPS in glioma patients to determine their correlation with histological grade using CT perfusion imaging. A total of 22 patients with gliomas underwent multislice CT perfusion imaging preoperatively. Low-grade and high-grade groups were categorized corresponding to WHO grade II gliomas and WHO grade III or IV gliomas, respectively, as determined by histopathological examination. rCBVs and rPSs were obtained from regions of maximal abnormality in tumor parenchyma on CBV and PS color perfusion maps. Perfusion parameters were compared using the Kruskal-Wallis test in order to evaluate the differences in relation to tumor grade. The Pearson coefficients of rCBV and rPS for each tumor grade were assessed using SPSS 13.0 software. (orig.)

  5. Assessment of Blood Flow in Hepatocellular Carcinoma: Correlations of Computed Tomography Perfusion Imaging and Circulating Angiogenic Factors

    Directory of Open Access Journals (Sweden)

    Chen-Pin Chou

    2013-08-01

    Full Text Available Hepatocellular carcinoma (HCC is a highly vascular tumor through the process of angiogenesis. To evaluate more non-invasive techniques for assessment of blood flow (BF in HCC, this study examined the relationships between BF of HCC measured by computer tomography (CT perfusion imaging and four circulating angiogenic factors in HCC patients. Interleukin 6 (IL-6, interleukin 8 (IL-8, vascular endothelial growth factor (VEGF, and platelet derived growth factor (PDGF in plasma were measured using Bio-Plex multiplex immunoassay in 21 HCC patients and eight healthy controls. Circulating IL-6, IL-8 and VEGF showed higher concentrations in HCC patients than in controls (p < 0.05, and predicted HCC occurrence better than chance (p < 0.01. Twenty-one patients with HCC received 21-phase liver imaging using a 64-slice CT. Total BF, arterial BF, portal BF, arterial fraction (arterial BF/total BF of the HCC and surrounding liver parenchyma, and HCC-parenchyma ratio were measured using a dual-vessel model. After analyzing the correlations between BF in HCC and four circulating angiogenic factors, we found that the HCC-parenchyma ratio of arterial BF showed a significantly positive correlation with the level of circulating IL-8 (p < 0.05. This circulating biomarker, IL-8, provides a non-invasive tool for assessment of BF in HCC.

  6. Monitoring dynamic reactions of red blood cells to UHF electromagnetic waves radiation using a novel micro-imaging technology.

    Science.gov (United States)

    Ruan, Ping; Yong, Junguang; Shen, Hongtao; Zheng, Xianrong

    2012-12-01

    Multiple state-of-the-art techniques, such as multi-dimensional micro-imaging, fast multi-channel micro-spetrophotometry, and dynamic micro-imaging analysis, were used to dynamically investigate various effects of cell under the 900 MHz electromagnetic radiation. Cell changes in shape, size, and parameters of Hb absorption spectrum under different power density electromagnetic waves radiation were presented in this article. Experimental results indicated that the isolated human red blood cells (RBCs) do not have obviously real-time responses to the ultra-low density (15 μW/cm(2), 31 μW/cm(2)) electromagnetic wave radiation when the radiation time is not more than 30 min; however, the cells do have significant reactions in shape, size, and the like, to the electromagnetic waves radiation with power densities of 1 mW/cm(2) and 5 mW/cm(2). The data also reveal the possible influences and statistical relationships among living human cell functions, radiation amount, and exposure time with high-frequency electromagnetic waves. The results of this study may be significant on protection of human being and other living organisms against possible radiation affections of the high-frequency electromagnetic waves.

  7. Real-Time Observation of Thrombus Growth Process in an Impeller of a Hydrodynamically Levitated Centrifugal Blood Pump by Near-Infrared Hyperspectral Imaging.

    Science.gov (United States)

    Sakota, Daisuke; Murashige, Tomotaka; Kosaka, Ryo; Fujiwara, Tatsuki; Nishida, Masahiro; Maruyama, Osamu

    2015-08-01

    Understanding the thrombus formation in cardiovascular devices such as rotary blood pumps is the most important issue in developing more hemocompatible devices. The objective of this study was to develop a hyperspectral imaging (HSI) method to visualize the thrombus growth process within a rotary blood pump and investigate the optical properties of the thrombus. An in vitro thrombogenic test was conducted using fresh porcine blood and a specially designed hydrodynamically levitated centrifugal blood pump with a transparent bottom. The pump rotating at 3000 rpm circulated the blood at 1.0 L/min. The bottom surface of the pump was illuminated with white light pulsed at the same frequency as the pump rotation, and the backward-scattered light was imaged using the HSI system. Using stroboscopic HSI and an image construction algorithm, dynamic spectral imaging at wavelengths ranging from 608 to 752 nm within the rotating pump was achieved. After completing the experiment, we collected the red thrombus formed in the pump impeller and quantified the thrombus hemoglobin concentration (Hbthrombus ). The spectrum changed around the center of the impeller, and the area of change expanded toward the impeller flow path. The shape corresponded approximately to the shape of the thrombus. The spectrum change indicated that the light scattering derived from red blood cells decreased. The Hbthrombus was 4.7 ± 1.3 g/dL versus a total hemoglobin of 13 ± 0.87 g/dL. The study revealed that Hbthrombus was reduced by the surrounding blood flow.

  8. Simultaneous PET/MR imaging of the brain: feasibility of cerebral blood flow measurements with FAIR-TrueFISP arterial spin labeling MRI

    Energy Technology Data Exchange (ETDEWEB)

    Stegger, Lars [Dept. of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls Univ. Tuebingen, Tuebingen (Germany); Dept. of Nuclear Medicine and European Inst. for Molecular Imaging, Univ. of Munster, Munster (Germany)], E-mail: stegger@uni-muenster.de; Martirosian, Petros; Schick, Fritz [Dept. of Radiology, Section of Experimental Radiology, Eberhard Karls Univ. Tuebingen, Tuebingen (Germany); Schwenzer, Nina; Pfannenberg, Christina; Claussen, Claus D. [Dept. of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls Univ. Tuebingen, Tuebingen (Germany); Bisdas, Sotirios [Dept. of Radiology, Diagnostic and Interventional Neuroradiology, Eberhard Karls Univ. Tuebingen, Tuebingen (Germany); Kolb, Armin; Pichler, Bernd [Dept. of Preclinical Imaging and Radiopharmacy, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Eberhard Karls Univ. Tuebingen, Tuebingen (Germany); Boss, Andreas [Dept. of Radiology, Diagnostic and Interventional Radiology, Eberhard Karls Univ. Tuebingen, Tuebingen (Germany); Inst. of Diagnostic and Interventional Radiology, Univ. Hospital Zurich, Zurich (Switzerland)

    2012-11-15

    Background Hybrid positron emission tomography/magnetic resonance imaging (PET/MRI) with simultaneous data acquisition promises a comprehensive evaluation of cerebral pathophysiology on a molecular, anatomical, and functional level. Considering the necessary changes to the MR scanner design the feasibility of arterial spin labeling (ASL) is unclear. Purpose To evaluate whether cerebral blood flow imaging with ASL is feasible using a prototype PET/MRI device. Material and Methods ASL imaging of the brain with Flow-sensitive Alternating Inversion Recovery (FAIR) spin preparation and true fast imaging in steady precession (TrueFISP) data readout was performed in eight healthy volunteers sequentially on a prototype PET/MRI and a stand-alone MR scanner with 128 x 128 and 192 x 192 matrix sizes. Cerebral blood flow values for gray matter, signal-to-noise and contrast-to-noise ratios, and relative signal change were compared. Additionally, the feasibility of ASL as part of a clinical hybrid PET/MRI protocol was demonstrated in five patients with intracerebral tumors. Results Blood flow maps showed good delineation of gray and white matter with no discernible artifacts. The mean blood flow values of the eight volunteers on the PET/MR system were 51 {+-} 9 and 51 {+-} 7 mL/100 g/min for the 128 x 128 and 192 x 192 matrices (stand-alone MR, 57 {+-} 2 and 55 {+-} 5, not significant). The value for signal-to-noise (SNR) was significantly higher for the PET/MRI system using the 192 x 192 matrix size (P < 0.01), the relative signal change (dS) was significantly lower for the 192 x 192 matrix size (P = 0.02). ASL imaging as part of a clinical hybrid PET/MRI protocol could successfully be accomplished in all patients in diagnostic image quality. Conclusion ASL brain imaging is feasible with a prototype hybrid PET/MRI scanner, thus adding to the value of this novel imaging technique.

  9. Imaging of Blood Flow in Cerebral Arteries with Dynamic Helical Computed Tomography Angiography (DHCTA) Using a 64-Row CT Scanner

    Energy Technology Data Exchange (ETDEWEB)

    Pekkola, J.; Kangasniemi, M. (Helsinki Medical Imaging Center, Helsinki Univ. Central Hospital, Helsinki (Finland))

    2009-08-15

    Background: Cerebral computed tomography angiography (CTA) depicts a structural image of intracranial arteries without providing much time-resolved information on blood flow dynamics. Current CT technology allows obtaining of rapidly repeated helical scans during the arterial contrast filling phase after an intravenous contrast injection. Purpose: To report our experience on dynamic CT imaging in determining the direction of contrast filling within proximal intracranial arteries of operated cerebral artery aneurysm patients. Such dynamic information can help detect vascular occlusion or severe spasm. The method is here referred to as dynamic helical CT angiography (DHCTA). Material and Methods: We retrospectively collected image and related technical data for 23 patients who underwent DHCTA and CTA during their first postoperative day after cerebral artery aneurysm surgery. For DHCTA, we had helically scanned a 4-cm tissue volume three times in succession with a 64-row CT scanner at intervals of 2.6 s during arterial contrast filling after an intravenous contrast injection. We assessed how well DHCTA succeeded in demonstrating the direction of contrast filling in the proximal intracranial arteries, evaluated clinically relevant structural information provided by DHCTA and CTA, and compared radiation doses for the two methods. Results: For 21 patients, DHCTA outlined the direction of contrast filling in proximal intracranial arteries. As to arterial spasm and residual filling of the operated aneurysm, CTA and DHCTA gave similar information. Radiation doses were higher (P<0.000001) for DHCTA than for CTA at 120 kV tube voltage. At 100 kV, the difference was smaller, but doses for DHCTA still exceeded (P<0.05) those for CTA. Conclusion: DHCTA gave dynamic information unobtainable with CTA and could prove useful in selected clinical settings

  10. Characterization of extracellular vesicles in whole blood: Influence of pre-analytical parameters and visualization of vesicle-cell interactions using imaging flow cytometry.

    Science.gov (United States)

    Fendl, Birgit; Weiss, René; Fischer, Michael B; Spittler, Andreas; Weber, Viktoria

    2016-09-09

    Extracellular vesicles are central players in intercellular communication and are released from the plasma membrane under tightly regulated conditions, depending on the physiological and pathophysiological state of the producing cell. Their heterogeneity requires a spectrum of methods for isolation and characterization, where pre-analytical parameters have profound impact on vesicle analysis, particularly in blood, since sampling, addition of anticoagulants, as well as post-sampling vesicle generation may influence the outcome. Here, we characterized microvesicles directly in whole blood using a combination of flow cytometry and imaging flow cytometry. We assessed the influence of sample agitation, anticoagulation, and temperature on post-sampling vesicle generation, and show that vesicle counts remained stable over time in samples stored without agitation. Storage with gentle rolling mimicking agitation, in contrast, resulted in strong release of platelet-derived vesicles in blood anticoagulated with citrate or heparin, whereas vesicle counts remained stable upon anticoagulation with EDTA. Using imaging flow cytometry, we could visualize microvesicles adhering to blood cells and revealed an anticoagulant-dependent increase in vesicle-cell aggregates over time. We demonstrate that vesicles adhere preferentially to monocytes and granulocytes in whole blood, while no microvesicles could be visualized on lymphocytes. Our data underscore the relevance of pre-analytical parameters in vesicle analysis and demonstrate that imaging flow cytometry is a suitable tool to study the interaction of extracellular vesicles with their target cells.

  11. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

    2015-06-15

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  12. Remote non-invasive stereoscopic imaging of blood vessels: first in-vivo results of a new multispectral contrast enhancement technology

    NARCIS (Netherlands)

    Wieringa, F.P.; Mastik, F.; Cate, F.J. ten; Neumann, H.A.M.; Steen, A.F.W. van der

    2006-01-01

    We describe a contactless optical technique selectively enhancing superficial blood vessels below variously pigmented intact human skin by combining images in different spectral bands. Two CMOS-cameras, with apochromatic lenses and dual-band LED-arrays, simultaneously streamed Left (L) and Right (R)

  13. Synaptic vesicle pools and dynamics.

    Science.gov (United States)

    Alabi, AbdulRasheed A; Tsien, Richard W

    2012-08-01

    Synaptic vesicles release neurotransmitter at chemical synapses, thus initiating the flow of information in neural networks. To achieve this, vesicles undergo a dynamic cycle of fusion and retrieval to maintain the structural and functional integrity of the presynaptic terminals in which they reside. Moreover, compelling evidence indicates these vesicles differ in their availability for release and mobilization in response to stimuli, prompting classification into at least three different functional pools. Ongoing studies of the molecular and cellular bases for this heterogeneity attempt to link structure to physiology and clarify how regulation of vesicle pools influences synaptic strength and presynaptic plasticity. We discuss prevailing perspectives on vesicle pools, the role they play in shaping synaptic transmission, and the open questions that challenge current understanding.

  14. Laser speckle contrast imaging of blood flow from anesthetized mice: correcting drifts in measurements due to breathing movements

    Science.gov (United States)

    Nogueira, Gesse E. C.; Ribeiro, Márcio A. C.; Campos, Juliane C.; Ferreira, Julio C. B.

    2015-06-01

    Background: Laser speckle contrast imaging allows non-invasive assessment of cutaneous blood flow. Although the technique is attractive to measure a quantity related to the skin blood flow (SBF) in anesthetized animal models, movements from breathing can mask the SBF signal. As a consequence, the measurement is overestimated because a variable amount of a DC component due to the breathing movements is added to the SBF signal. Objective: To evaluate a method for estimating the background level of the SBF signal, rejecting artefacts from breathing. Methods: A baseline correction method used for accurate DNA sequencing was evaluated, based on estimating the background level of a signal in small temporal sliding-windows. The method was applied to evaluate a mouse model of hindlimb ischemia. SBF signals from hindlimbs of anesthetized C57BL/6 mice (n=13) were registered. The mean SBF (Fi and Fc from ischemic and control hindlimbs) were computed from the registers and from the corresponding estimated background levels (Fib and Fcb from ischemic and control hindlimbs). Results: The mean values of the percentages (a measure of ischemia) MI = (Fi/Fc).100 and MIb = (Fib/Fcb).100 were computed to be 30+/-4% and 23+/-3% respectively (mean +/- SE). Evidences of statistical differences between both, ischemic and control hindlimbs, were obtained (p<0.05, paired student-t). The mean error [(MI-MIb)/MIb].100 obtained was 45+/-14% (mean+/-SE). Conclusion: The recovery of a corrupted SBF signal by breathing artefacts is feasible, allowing more accurate measurements.

  15. Cerebral blood volume calculated by dynamic susceptibility contrast-enhanced perfusion MR imaging: preliminary correlation study with glioblastoma genetic profiles.

    Directory of Open Access Journals (Sweden)

    Inseon Ryoo

    Full Text Available PURPOSE: To evaluate the usefulness of dynamic susceptibility contrast (DSC enhanced perfusion MR imaging in predicting major genetic alterations in glioblastomas. MATERIALS AND METHODS: Twenty-five patients (M:F = 13∶12, mean age: 52.1±15.2 years with pathologically proven glioblastoma who underwent DSC MR imaging before surgery were included. On DSC MR imaging, the normalized relative tumor blood volume (nTBV of the enhancing solid portion of each tumor was calculated by using dedicated software (Nordic TumorEX, NordicNeuroLab, Bergen, Norway that enabled semi-automatic segmentation for each tumor. Five major glioblastoma genetic alterations (epidermal growth factor receptor (EGFR, phosphatase and tensin homologue (PTEN, Ki-67, O6-methylguanine-DNA methyltransferase (MGMT and p53 were confirmed by immunohistochemistry and analyzed for correlation with the nTBV of each tumor. Statistical analysis was performed using the unpaired Student t test, ROC (receiver operating characteristic curve analysis and Pearson correlation analysis. RESULTS: The nTBVs of the MGMT methylation-negative group (mean 9.5±7.5 were significantly higher than those of the MGMT methylation-positive group (mean 5.4±1.8 (p = .046. In the analysis of EGFR expression-positive group, the nTBVs of the subgroup with loss of PTEN gene expression (mean: 10.3±8.1 were also significantly higher than those of the subgroup without loss of PTEN gene expression (mean: 5.6±2.3 (p = .046. Ki-67 labeling index indicated significant positive correlation with the nTBV of the tumor (p = .01. CONCLUSION: We found that glioblastomas with aggressive genetic alterations tended to have a high nTBV in the present study. Thus, we believe that DSC-enhanced perfusion MR imaging could be helpful in predicting genetic alterations that are crucial in predicting the prognosis of and selecting tailored treatment for glioblastoma patients.

  16. Patent pools: Intellectual property rights and competition

    NARCIS (Netherlands)

    Rodriguez, V.

    2010-01-01

    Patent pools do not correct all problems associated with patent thickets. In this respect, patent pools might not stop the outsider problem from striking pools. Moreover, patent pools can be expensive to negotiate, can exclude patent holders with smaller numbers of patents or enable a group of major

  17. Hard X-ray in-line outline imaging for blood vessels: first generation synchrotron radiation without contrast agents in vitro

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: Phase-contrast X-ray imaging which reduces radiation exposure, is a promising technique for observing the inner structures of biological soft tissues without the aid of contrast agents.The present study intends to depict blood vessels of rabbits and human livers with hard X-ray in-line out line imaging without contrast agents using synchrotron radiation. Methods: All samples were fixed with formalin and sliced into 6 mm sections. The imaging experiments were performed with Fuji-IX80 films on the 4W1A light beam of the first generation synchrotron radiation in Beijing, China. The device of the ex periment, which supplies a maximum light spot size of 20× 10 mm was similar to that of in-line holography. The photon energy was set at 8 KeV and high quality imagines were obtained by altering the distance between the sample and the film. Results: The trees of rabbit-liver blood vessels and the curved vessels of the cirrhotic human liver were revealed on the images, where vessels < 20 μm in diameter were differentiated. Conclusion: These results show that the blood vessels of liver samples can be revealed by using hard X-ray in-line outline imaging with the first generation synchrotron radiation without contrast agents.

  18. Domain-Size Pooling in Local Descriptors: DSP-SIFT

    OpenAIRE

    Dong, Jingming; Soatto, Stefano

    2014-01-01

    We introduce a simple modification of local image descriptors, such as SIFT, based on pooling gradient orientations across different domain sizes, in addition to spatial locations. The resulting descriptor, which we call DSP-SIFT, outperforms other methods in wide-baseline matching benchmarks, including those based on convolutional neural networks, despite having the same dimension of SIFT and requiring no training.

  19. Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas

    DEFF Research Database (Denmark)

    Thomsen, H; Steffensen, E; Larsson, Elna-Marie

    2012-01-01

    technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies. Purpose: To assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC......, and glioblastomas. Results: rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r ¼ 0.60) and to the cerebellum (r ¼ 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated......-MRI using two different regions for normalization and two different measurement approaches. Material and Methods: Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and r...

  20. Preoperative 3T high field blood oxygen level dependent functional magnetic resonance imaging for glioma involving sensory cortical areas

    Institute of Scientific and Technical Information of China (English)

    LI Shao-wu; WANG Jiang-fei; JIANG Tao; LI Shou-wei; ZHANG Wen-bo; LI Zi-xiao; ZHANG Zhong; DAI Jian-ping; WANG Zhong-cheng

    2010-01-01

    Background Localization of sensory cortical areas during the operation is essential to preserve the sensory function.Intraoperative direct electrostimulation under awake anesthesia is the golden standard but time-consuming. We applied 3T high field blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to identify the relationship between glioma and cortical sensory areas preoperatively and to guide intraoperative direct electrostimulation for quick and precise localization.Methods Five glioma patients with sensory cortex involvement by or next to the lesion had preoperative BOLD fMRI to determine the spatial relationship of cortical sensory areas to the tumours. Bilateral hand opposite movement was performed by these patients for fMRI. Precentral and postcentral gyri were identified by electrical stimulation during the operation. Karnofsky Performance Status scores of the patients' pre- and postoperative and the role of BOLD fMRI were evaluated.Results The cortical sensory areas were all activated in five glioma patients involving postcentral gyrus areas by BOLDf MRI with bilateral hand opposite movement. The detected activation areas corresponded with the results from cortical electrical stimulation.Conclusions The relationship between cortical sensory areas and tumour can be accurately shown by BOLD fMRI before operation. And the information used to make the tumour resection could obtain good clinical results.

  1. Technetium-99m d,l-HM-PAO: a new radiopharmaceutical for SPECT imaging of regional cerebral blood perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Neirinckx, R.D.; Canning, L.R.; Piper, I.M.; Nowotnik, D.P.; Pickett, R.D.; Holmes, R.A.; Volkert, W.A.; Forster, A.M.; Weisner, P.S.; Marriott, J.A.

    1987-02-01

    Following investigation of a large number of new ligands based upon propylene amine oxime (PnAO) the d,l-diastereoisomer of hexamethyl propyleneamine oxime (HM-PAO) was selected as the preferred ligand for 99mTc as a tracer for cerebral perfusion imaging. The neutral, lipophilic 99mTc complex of d,l-HM-PAO was formed in high yield by stannous reduction of 99Mo/99mTc generator eluate using a kit formulation of the ligand. Two minutes following i.v. administration of this complex in rats, 2.25% of the injected dose appears in the brain. Little washout of the tracer is observed up to 24 hr postinjection. By qualitative autoradiographic comparison with iodoantipyrine this new radiopharmaceutical displays blood flow dependent brain uptake with little redistribution of the tracer over time. The lipophilic 99mTc complex converts slowly in vitro to a secondary complex. This conversion process may account for the ability of (99mTc)d,l-HM-PAO to be retained within the brain without redistribution.

  2. EP BICYCLE POOL - VIGNETTES 2002

    CERN Multimedia

    EP-SMI Help Desk

    2002-01-01

    The vignettes (insurance certificates) for 2002 become obligatory from 1 June. If you have a bicycle from the EP Pool, please bring it to the EP-SMI Help Desk (Building 124) on any working day up to 31 May between 8h.30 - 12h.00 or 13h.30 - 17h.30. EP-SMI Help Desk

  3. Weld pool boundary and weld bead shape reconstruction based on passive vision in P-GMAW

    Institute of Scientific and Technical Information of China (English)

    Yan Zhihong; Zhang Guangjun; Gao Hongming; Wu Lin

    2006-01-01

    A passive visual sensing system is established in this research, and clear weld pool images in pulsed gas metal arc welding ( P-GMA W) can be captured with this system. The three-dimensional weld pool geometry, especially the weld height,is not only a crucial factor in determining workpiece mechanical properties, but also an important parameter for reflecting the penetration. A new three-dimensional (3D) model is established to describe the weld pool geometry in P-GMAW. Then, a series of algorithms are developed to extract the model geometrical parameters from the weld pool images. Furthermore, the method to reconstruct the 3D shape of weld pool boundary and weld bead from the two-dimensional images is investigated.

  4. Line-scanning particle image velocimetry: an optical approach for quantifying a wide range of blood flow speeds in live animals.

    Directory of Open Access Journals (Sweden)

    Tyson N Kim

    Full Text Available BACKGROUND: The ability to measure blood velocities is critical for studying vascular development, physiology, and pathology. A key challenge is to quantify a wide range of blood velocities in vessels deep within living specimens with concurrent diffraction-limited resolution imaging of vascular cells. Two-photon laser scanning microscopy (TPLSM has shown tremendous promise in analyzing blood velocities hundreds of micrometers deep in animals with cellular resolution. However, current analysis of TPLSM-based data is limited to the lower range of blood velocities and is not adequate to study faster velocities in many normal or disease conditions. METHODOLOGY/PRINCIPAL FINDINGS: We developed line-scanning particle image velocimetry (LS-PIV, which used TPLSM data to quantify peak blood velocities up to 84 mm/s in live mice harboring brain arteriovenous malformation, a disease characterized by high flow. With this method, we were able to accurately detect the elevated blood velocities and exaggerated pulsatility along the abnormal vascular network in these animals. LS-PIV robustly analyzed noisy data from vessels as deep as 850 µm below the brain surface. In addition to analyzing in vivo data, we validated the accuracy of LS-PIV up to 800 mm/s using simulations with known velocity and noise parameters. CONCLUSIONS/SIGNIFICANCE: To our knowledge, these blood velocity measurements are the fastest recorded with TPLSM. Partnered with transgenic mice carrying cell-specific fluorescent reporters, LS-PIV will also enable the direct in vivo correlation of cellular, biochemical, and hemodynamic parameters in high flow vascular development and diseases such as atherogenesis, arteriogenesis, and vascular anomalies.

  5. Molten pool and temperature field in CO2 laser welding

    Institute of Scientific and Technical Information of China (English)

    Duan Aiqin; Chen Li; Wang Yajun; Hu Lunji

    2006-01-01

    Two measuring methods, high-speed camera and optical monitoring system, were used to study processes of laser welding. Molten pool, cooling time and temperature field were analyzed based on real measured images and optical signal data. The results show that the width of molten pool is almost equal to the width of weld, and length is about 7.8 mm. The solidification time is about 0. 5 s and the temperature gradient is great, so HAZ is very small. The method and results will be of benefit to build the relationship between welding parameters and microstructure.

  6. Dynamic changes in the distribution and time course of blood-brain barrier-permeative nitroxides in the mouse head with EPR imaging: visualization of blood flow in a mouse model of ischemia.

    Science.gov (United States)

    Emoto, Miho C; Sato-Akaba, Hideo; Hirata, Hiroshi; Fujii, Hirotada G

    2014-09-01

    Electron paramagnetic resonance (EPR) imaging using nitroxides as redox-sensitive probes is a powerful, noninvasive method that can be used under various physiological conditions to visualize changes in redox status that result from oxidative damage. Two blood-brain barrier-permeative nitroxides, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (HMP) and 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy (MCP), have been widely used as redox-sensitive probes in the brains of small animals, but their in vivo distribution and properties have not yet been analyzed in detail. In this study, a custom-made continuous-wave three-dimensional (3D) EPR imager was used to obtain 3D EPR images of mouse heads using MCP or HMP. This EPR imager made it possible to take 3D EPR images reconstructed from data from 181 projections acquired every 60s. Using this improved EPR imager and magnetic resonance imaging, the distribution and reduction time courses of HMP and MCP were examined in mouse heads. EPR images of living mice revealed that HMP and MCP have different distributions and different time courses for entering the brain. Based on the pharmacokinetics of the reduction reactions of HMP and MCP in the mouse head, the half-lives of HMP and MCP were clearly and accurately mapped pixel by pixel. An ischemic mouse model was prepared, and the half-life of MCP was mapped in the mouse head. Compared to the half-life in control mice, the half-life of MCP in the ischemic model mouse brain was significantly increased, suggesting a shift in the redox balance. This in vivo EPR imaging method using BBB-permeative MCP is a useful noninvasive method for assessing changes in the redox status in mouse brains under oxidative stress.

  7. [Infections transmitted in swimming pools].

    Science.gov (United States)

    von Suzani, C; Hazeghi, P

    1976-01-01

    Public swimmingpools can be the source of infections due to micro-organism such as mycobacterium balnei, adeno and enteroviruses, the virus of plantar warts and molluscum contagiosum, the TRIC-Agent of swimmingpool-conjonctivitis and pathogenic fungi. The transmission of trichomonas vaginalis is considered unlikely-Water of pools, supposed to present satisfactory qualities by standard controls, was found to contain pathogenic staphylococci and pseudomonas aeruginosa. Effective preventive measures include the continuous recording of the redox-potential of the water, limiting the number of visitors to pool design specifications, better desinfection of sanitary installations, regular maintenance of technical equipment including frequent backwashing of filters and exclusion of visitors with communicable disease.

  8. A Consensual Linear Opinion Pool

    CERN Document Server

    Carvalho, Arthur

    2012-01-01

    We propose a pooling method to aggregate expert opinions. Intuitively, it works as if the experts were continuously updating their opinions in order to accommodate the expertise of others. Each updated opinion takes the form of a linear opinion pool, where the weight that an expert assigns to a peer's opinion is inversely related to the distance between their opinions. In other words, experts are assumed to prefer opinions that are close to their own opinions. We prove that such an updating process leads to consensus, i.e., the experts all converge towards the same opinion. Further, we show that if experts are rewarded using the quadratic scoring rule, then the above mentioned assumption follows naturally. We empirically demonstrate the efficacy of our method using real-world data.

  9. Assessment of early renal allograft dysfunction with blood oxygenation level-dependent MRI and diffusion-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Yoon [Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Chan Kyo, E-mail: chankyokim@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, Byung Kwan [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Sung Ju; Lee, Sanghoon [Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Huh, Wooseong [Department of Nephrology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2014-12-15

    Highlights: • R2* and ADC in renal allografts are moderately correlated with eGFR. • R2* and ADC are lower in early allograft dysfunction than normal allograft function. • No significant difference between AR and ATN was found in both R2* and ADC. - Abstract: Purpose: To investigate blood oxygenation level-dependent (BOLD) MRI and diffusion-weighted imaging (DWI) at 3 T for assessment of early renal allograft dysfunction. Materials and methods: 34 patients with a renal allograft (early dysfunction, 24; normal, 10) were prospectively enrolled. BOLD MRI and DWI were performed at 3 T. R2* and apparent diffusion coefficient (ADC) values were measured in cortex and medulla of the allografts. Correlation between R2* or ADC values and estimated glomerular filtration rate (eGFR) was investigated. R2* or ADC values were compared among acute rejection (AR), acute tubular necrosis (ATN) and normal function. Results: In all renal allografts, cortical or medullary R2* and ADC values were moderately correlated with eGFR (P < 0.05). Early dysfunction group showed lower R2* and ADC values than normal function group (P < 0.05). AR or ATN had lower R2* values than normal allografts (P < 0.05), and ARs had lower cortical ADC values than normal allografts (P < 0.05). No significant difference of R2* or ADC values was found between AR and ATN (P > 0.05). Conclusion: BOLD MRI and DWI at 3 T may demonstrate early functional state of renal allografts, but may be limited in characterizing a cause of early renal allograft dysfunction. Further studies are needed.

  10. Effects of Ginkgo biloba on cerebral blood flow assessed by quantitative MR perfusion imaging: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Mashayekh, Ameneh; Pham, Dzung L.; Yousem, David M.; Dizon, Mercedes; Barker, Peter B.; Lin, Doris D.M. [Johns Hopkins University School of Medicine, Department of Radiology, Division of Neuroradiology, Baltimore, MD (United States)

    2011-03-15

    Extract of Ginkgo biloba (EGb), a dietary supplement used for a number of conditions including dementia, has been suggested to increase cerebral blood flow (CBF). The purpose of this study was to determine if changes in CBF could be detected by dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) in elderly human subjects taking EGb. DSC-MRI was performed in nine healthy men (mean age 61 {+-} 10 years) before and after 4 weeks of 60 mg EGb taken twice daily. One subject underwent six consecutive scans to evaluate intrasubject reproducibility. CBF values were computed before and after EGb, and analyzed at three different levels of spatial resolution, using voxel-based statistical parametric mapping (SPM), and regions of interest in different lobes, and all regions combined. Normalized intrasubject CBF (nCBF) measurements had a standard deviation of 7% and 4% in gray and white matter (WM) regions, respectively. SPM using an uncorrected, voxel-level threshold of P {<=} 0.001 showed a small CBF increase in the left parietal-occipital region. CBF in individual lobar regions did not show any significant change post-EGb, but all regions combined showed a significant increase of non-normalized CBF after EGb (15% in white and 13% in gray matter, respectively, P {<=} 0.0001). nCBF measured by DSC-MRI has good intrasubject reproducibility. In this small cohort of normal elderly individuals, a mild increase in CBF is found in the left parietal-occipital WM after EGb, as well as a small but statistically significant increase in global CBF. (orig.)

  11. Computational imaging analysis of fibrin matrices with the inclusion of erythrocytes from homozygous SS blood reveals agglomerated and amorphous structures.

    Science.gov (United States)

    Averett, Rodney D; Norton, David G; Fan, Natalie K; Platt, Manu O

    2017-01-01

    Sickle cell disease is a single point mutation disease that is known to alter the coagulation system, leading to hypercoagulable plasma conditions. These hypercoagulable conditions can lead to complications in the vasculature, caused by fibrin clots that form undesirably. There is a need to understand the morphology and structure of fibrin clots from patients with sickle cell disease, as this could lead to further discovery of treatments and life-saving therapies. In this work, a computational imaging analysis method is presented to evaluate fibrin agglomeration in the presence of erythrocytes (RBCs) homozygous for the sickle cell mutation (SS). Numerical algorithms were used to determine agglomeration of fibrin fibers within a matrix with SS RBCs to test the hypothesis that fibrin matrices with the inclusion of SS RBCs possess a more agglomerated structure than native fibrin matrices with AA RBCs. The numerical results showed that fibrin structures with SS RBCs displayed an overall higher degree of agglomeration as compared to native fibrin structures. The computational algorithm was also used to evaluate fibrin fiber overlap (aggregation) and anisotropy (orientation) in normal fibrin matrices compared to fibrin matrices polymerized around SS RBCs; however, there was no statistical difference. Ultrasound measurements of stiffness revealed rigid RBCs in the case of samples derived from homozygous SS blood, and densely evolving matrices, when compared to normal fibrin with the inclusion of AA RBCs. An agglomeration model is suggested to quantify the fibrin aggregation/clustering near RBCs for both normal fibrin matrices and for the altered structures. The results of this work are important in the sense that the understanding of aggregation and morphology in fibrin clots with incorporation of RBCs from persons living with sickle cell anemia may elucidate the complexities of comorbidities and other disease complications.

  12. 7.0-T magnetic resonance imaging characterization of acute blood-brain-barrier disruption achieved with intracranial irreversible electroporation.

    Directory of Open Access Journals (Sweden)

    Paulo A Garcia

    Full Text Available The blood-brain-barrier (BBB presents a significant obstacle to the delivery of systemically administered chemotherapeutics for the treatment of brain cancer. Irreversible electroporation (IRE is an emerging technology that uses pulsed electric fields for the non-thermal ablation of tumors. We hypothesized that there is a minimal electric field at which BBB disruption occurs surrounding an IRE-induced zone of ablation and that this transient response can be measured using gadolinium (Gd uptake as a surrogate marker for BBB disruption. The study was performed in a Good Laboratory Practices (GLP compliant facility and had Institutional Animal Care and Use Committee (IACUC approval. IRE ablations were performed in vivo in normal rat brain (n = 21 with 1-mm electrodes (0.45 mm diameter separated by an edge-to-edge distance of 4 mm. We used an ECM830 pulse generator to deliver ninety 50-μs pulse treatments (0, 200, 400, 600, 800, and 1000 V/cm at 1 Hz. The effects of applied electric fields and timing of Gd administration (-5, +5, +15, and +30 min was assessed by systematically characterizing IRE-induced regions of cell death and BBB disruption with 7.0-T magnetic resonance imaging (MRI and histopathologic evaluations. Statistical analysis on the effect of applied electric field and Gd timing was conducted via Fit of Least Squares with α = 0.05 and linear regression analysis. The focal nature of IRE treatment was confirmed with 3D MRI reconstructions with linear correlations between volume of ablation and electric field. Our results also demonstrated that IRE is an ablation technique that kills brain tissue in a focal manner depicted by MRI (n = 16 and transiently disrupts the BBB adjacent to the ablated area in a voltage-dependent manner as seen with Evan's Blue (n = 5 and Gd administration.

  13. Coronary wall MR imaging in patients with rapid heart rates: a feasibility study of black-blood steady-state free precession (SSFP).

    Science.gov (United States)

    Lin, Kai; Bi, Xiaoming; Taimen, Kirsi; Zuehlsdorff, Sven; Lu, Biao; Carr, James; Li, Debiao

    2012-03-01

    We assessed the hypothesis that black-blood steady-state free precession (SSFP) would provide coronary wall images comparable to images from TSE and have better performance than TSE under conditions of fast heart rate. With IRB approval, thirty participants without a history of coronary artery disease (19 men, 11 women, 26-83 y/o) were scanned with a 1.5 T MR scanner. Cross-sectional black-blood images of the proximal portions of coronary arteries were acquired with a two-dimensional (2D), double inversion recovery (DIR) prepared TSE sequence and a 2D DIR SSFP sequence on the same planes. Image quality (ranked with a 4-point system, scored from 0 to 3), vessel wall area and thickness, signal-to-noise ratio (SNR) of the wall and contrast-to-noise ratio (CNR, wall to lumen) were compared between SSFP and TSE with SPSS software (v 13.0). Totally 28 scans were completed. For SSFP and TSE, there was no difference in image quality. SSFP had a higher SNR (23.7 ± 10.1 vs. 14.4 ± 5.2, P < 0.001) and wall-lumen CNR (8.8 ± 4.5 vs. 6.7 ± 3.2, P = 0.001). Good agreements between measured wall area (r = 0.701, P < 0.001) and thickness (r = 0.560, P < 0.001) were found. For 10 participants with heart rate more than 80 beats/min, the image quality of SSFP was higher than TSE (P = 0.016). SSFP provided image quality and measurement accuracy that was comparable to TSE. With its higher performance under fast heart rate conditions, SSFP may break through the existing thresholds for heart rate and extend clinical applicability of coronary wall MR imaging to a larger population.

  14. Characterisation of contrast agent microbubbles for ultrasound imaging and therapy research

    OpenAIRE

    2016-01-01

    The high efficiency with which gas microbubbles can scatter ultrasound compared to the surrounding blood pool or tissues has led to their widespread employment as contrast agents in ultrasound imaging. In recent years their applications have been extended to include super-resolution imaging and the stimulation of localized bio-effects for therapy. The growing exploitation of contrast agents in ultrasound, and in particular these recent developments, have amplified the need to characterize and...

  15. Sustainability of common pool resources

    Science.gov (United States)

    Timilsina, Raja Rajendra; Kamijo, Yoshio

    2017-01-01

    Sustainability has become a key issue in managing natural resources together with growing concerns for capitalism, environmental and resource problems. We hypothesize that the ongoing modernization of competitive societies, which we refer to as “capitalism,” affects human nature for utilizing common pool resources, thus compromising sustainability. To test this hypothesis, we design and implement a set of dynamic common pool resource games and experiments in the following two types of Nepalese areas: (i) rural (non-capitalistic) and (ii) urban (capitalistic) areas. We find that a proportion of prosocial individuals in urban areas is lower than that in rural areas, and urban residents deplete resources more quickly than rural residents. The composition of proself and prosocial individuals in a group and the degree of capitalism are crucial in that an increase in prosocial members in a group and the rural dummy positively affect resource sustainability by 65% and 63%, respectively. Overall, this paper shows that when societies move toward more capitalistic environments, the sustainability of common pool resources tends to decrease with the changes in individual preferences, social norms, customs and views to others through human interactions. This result implies that individuals may be losing their coordination abilities for social dilemmas of resource sustainability in capitalistic societies. PMID:28212426

  16. Complex polarization-phase and spatial-frequency selections of laser images of blood-plasma films in diagnostics of changes in their polycrystalline structure

    Science.gov (United States)

    Ushenko, Yu. A.; Angelskii, P. O.; Dubolazov, A. V.; Karachevtsev, A. O.; Sidor, M. I.; Mintser, O. P.; Oleinichenko, B. P.; Bizer, L. I.

    2013-10-01

    We present a theoretical formalism of correlation phase analysis of laser images of human blood plasma with spatial-frequency selection of manifestations of mechanisms of linear and circular birefringence of albumin and globulin polycrystalline networks. Comparative results of the measurement of coordinate distributions of the correlation parameter—the modulus of the degree of local correlation of amplitudes—of laser images of blood plasma taken from patients of three groups—healthy patients (donors), rheumatoid-arthritis patients, and breast-cancer patients—are presented. We investigate values and ranges of change of statistical (the first to fourth statistical moments), correlation (excess of autocorrelation functions), and fractal (slopes of approximating curves and dispersion of extrema of logarithmic dependences of power spectra) parameters of coordinate distributions of the degree of local correlation of amplitudes. Objective criteria for diagnostics of occurrence and differentiation of inflammatory and oncological states are determined.

  17. Bone, blood vessels, and muscle detection algorithm and creating database based on dynamic and non-dynamic multi-slice CT image of head and neck

    Science.gov (United States)

    Shabbir Ahamed, Mohammed; Kubo, Mitsuru; Kawata, Yoshiki; Niki, Noboru; Iwasaki, Hirokazu

    2007-03-01

    Nowadays, dental CT images play more and more important roles in oral clinical applications. Our research is important particularly in the field of dentistry. We are using non-dynamic and dynamic CT image for our research. We are creating our database of bone, blood vessels and muscles of head and neck. This database contains easy case and difficult case of head and neck's bone, blood vessels and muscle. There are lots of difficult cases in our database. Teeth separation and condylar process separation is difficult case. External carotid artery has many branches and they are attached with vain so it is difficult to separate. All muscle threshold value is same and they are attaching with each other so muscle separation is very difficult. These databases also contain different age's patients. For this reason our database becomes an important tool for dental students and also important assets for diagnosis. After completion our database we can link it with other dental application.

  18. Pool power control in remelting systems

    Science.gov (United States)

    Williamson, Rodney L.; Melgaard, David K.; Beaman, Joseph J.

    2011-12-13

    An apparatus for and method of controlling a remelting furnace comprising adjusting current supplied to an electrode based upon a predetermined pool power reference value and adjusting the electrode drive speed based upon the predetermined pool power reference value.

  19. The warm pool in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Vinayachandran, P.N.; Shetye, S.R.

    The structure of the warm pool (region with temperature greater than 28 degrees C) in the equatorial Indian Ocean is examined and compared with its counterpart in the Pacific Ocean using the climatology of Levitus. Though the Pacific warm pool...

  20. Angioplasty and stenting for severe vertebral artery oriifce stenosis:effects on cerebellar function remodeling veriifed by blood oxygen level-dependent functional magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Bo Liu; Zhiwei Li; Peng Xie

    2014-01-01

    Vertebral artery oriifce stenting may improve blood supply of the posterior circulation of the brain to regions such as the cerebellum and brainstem. However, previous studies have mainly focused on recovery of cerebral blood lfow and perfusion in the posterior circulation after inter-ventional therapy. This study examined the effects of functional recovery of local brain tissue on cerebellar function remodeling using blood oxygen level-dependent functional magnetic reso-nance imaging before and after interventional therapy. A total of 40 Chinese patients with severe unilateral vertebral artery oriifce stenosis were enrolled in this study. Patients were equally and randomly assigned to intervention and control groups. The control group received drug treat-ment only. The intervention group received vertebral artery oriifce angioplasty and stenting+identical drug treatment to the control group. At 13 days after treatment, the Dizziness Handicap Inventory score was compared between the intervention and control groups. Cerebellar function remodeling was observed between the two groups using blood oxygen level-dependent function-al magnetic resonance imaging. The improvement in dizziness handicap and cerebellar function was more obvious in the intervention group than in the control group. Interventional therapy for severe vertebral artery oriifce stenosis may effectively promote cerebellar function remodeling and exert neuroprotective effects.

  1. Images

    Data.gov (United States)

    National Aeronautics and Space Administration — Images for the website main pages and all configurations. The upload and access points for the other images are: Website Template RSW images BSCW Images HIRENASD...

  2. Blood sugar test - blood

    Science.gov (United States)

    ... blood glucose level ( hypoglycemia ) may be due to: Hypopituitarism (a pituitary gland disorder) Underactive thyroid gland or ... tonic-clonic seizure Glucagon blood test Glucagonoma Hyperthyroidism Hypopituitarism Hypothyroidism Insulinoma Low blood sugar Multiple endocrine neoplasia ( ...

  3. 7 CFR 1032.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1032.7 Section 1032.7 Agriculture... Handling Definitions § 1032.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (i) of...

  4. 7 CFR 1033.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1033.7 Section 1033.7 Agriculture... Handling Definitions § 1033.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, or a plant specified in paragraph (j) of...

  5. 7 CFR 1124.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1124.7 Section 1124.7 Agriculture... Regulating Handling Definitions § 1124.7 Pool plant. Pool plant means a plant, unit of plants, or a system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified...

  6. 7 CFR 1126.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1126.7 Section 1126.7 Agriculture... Handling Definitions § 1126.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant...

  7. 7 CFR 1131.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1131.7 Section 1131.7 Agriculture... Handling Definitions § 1131.7 Pool plant. Pool Plant means a plant or unit of plants specified in paragraphs (a) through (e) of this section, but excluding a plant specified in paragraph (g) of this...

  8. 7 CFR 1007.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1007.7 Section 1007.7 Agriculture... Handling Definitions § 1007.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant...

  9. 7 CFR 1005.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1005.7 Section 1005.7 Agriculture... Handling Definitions § 1005.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant...

  10. 7 CFR 1001.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1001.7 Section 1001.7 Agriculture... Handling Definitions § 1001.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant described in paragraph (h)...

  11. 7 CFR 1006.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1006.7 Section 1006.7 Agriculture... Handling Definitions § 1006.7 Pool plant. Pool plant means a plant specified in paragraphs (a) through (d) of this section, a unit of plants as specified in paragraph (e) of this section, or a plant...

  12. 7 CFR 1030.7 - Pool plant.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Pool plant. 1030.7 Section 1030.7 Agriculture... Handling Definitions § 1030.7 Pool plant. Pool plant means a plant, unit of plants, or system of plants as specified in paragraphs (a) through (f) of this section, but excluding a plant specified in paragraph (h)...

  13. 28 CFR 540.64 - Press pools.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Press pools. 540.64 Section 540.64... PERSONS IN THE COMMUNITY Contact With News Media § 540.64 Press pools. (a) The Warden may establish a press pool whenever he or she determines that the frequency of requests for interviews and...

  14. A Multicenter study on preparation of Leukodepleted Platelet Concentrates from Pooled whole blood-derived platelets%全血制备浓缩血小板的汇集及滤除白细胞的多中心研究

    Institute of Scientific and Technical Information of China (English)

    王红; 吴瑕; 钟锐; 贺曾; 曹晔; 何语良; 陈洁; 刘嘉馨

    2012-01-01

    Objective To cooperate with a number of blood centers and evaluate the quality of pooled platelet and leukocyte depletion, which aims to supply basis for establishing operating procedures and quality standard of pooled platelet and leukocyte depletion. Methods PCs was prepared from 400 ml fresh whole blood by platelet-rich plasma (PRP) or buffy-coat (BC) method. 10 to 16 units of ABO-matched PCs were pooled, and then filtered with two types of domestic filters (namely group A and B) randomly. The conventional and functional indicators of platelet were evaluated before and after filtering, and the total samples were 202. Results The total of cases that number of platelet was more than 2. 4 × 1011 was 147, including 77 cases in group A and 70 cases in group B. In group A the number of platelet and leukocyte before and after filtering were (2. 90 ±0.45) xlO" 75(2.60±0.43) × 1011 ,(176.45 ±135.67) × 106 VS( 1.00 ±2.29) ×106 respectively ,and in group B the number of platelet and leukocyte before and after filtering were(2. 80 ±0. 36) × 1011 VS(2. 40 ± 0.37) × 1011, (175. 76 ±147. 84) × 106 VS(0. 30 ±0. 72) × 106 respectively. While the total of cases that number of platelet was less than 2. 4 × 1011 was 55, including 29 cases in group A and 26 cases in group B. In group A the number of platelet and leukocyte before and after filtering were (1. 71 ±0.39)×1011 VS( 1.43 ±0.42) × 1011 ,(65. 85 ±110. 97) ×106 VS (3. 7 ±3. 98) × 106 respectively,and in group B the number of platelet and leukocyte before and after filtering were(l. 79 ±0.48) ×1011 VS(1.42±0.46) × 1011 ,(70. 63 ±145. 55) × 106 VS(1. 45 ±2. 66) × 106 respectively. There were no significant difference(P>0. 05) of these indicators such as pH value,hypotonic shock response (HSR) ,CD62p expression ( % ) and platelet aggregation after filtering in group A and B. Conclusion Pooling and filtering platelet concentrates prepared by PRP and BC method can remove leukocyte effectively and

  15. Simultaneous assessment of cerebral blood volume and diffusion heterogeneity using hybrid IVIM and DK MR imaging: initial experience with brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wen-Chau [National Taiwan University, Graduate Institute of Oncology, Taipei (China); National Taiwan University, Graduate Institute of Clinical Medicine, Taipei (China); National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, Taipei (China); National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); Yang, Shun-Chung; Chen, Ya-Fang; My, Pei-Chi [National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); Tseng, Han-Min [National Taiwan University Hospital, Department of Neurology, Taipei (China)

    2017-01-15

    To investigate the feasibility of simultaneously assessing cerebral blood volume and diffusion heterogeneity using hybrid diffusion-kurtosis (DK) and intravoxel-incoherent-motion (IVIM) MR imaging. Fifteen healthy volunteers and 30 patients with histologically proven brain tumours (25 WHO grade II-IV gliomas and five metastases) were recruited. On a 3-T system, diffusion-weighted imaging was performed with six b-values ranging from 0 to 1,700 s/mm{sup 2}. Nonlinear least-squares fitting was employed to extract diffusion coefficient (D), diffusion kurtosis coefficient (K, a measure of the degree of non-Gaussian and heterogeneous diffusion) and intravascular volume fraction (f, a measure proportional to cerebral blood volume). Repeated-measures multivariate analysis of variance and receiver operating characteristic analysis were performed to assess the ability of D/K/f in differentiating contrast-enhanced tumour from peritumoral oedema and normal-appearing white matter. Based on our imaging setting (baseline signal-to-noise ratio = 32-128), coefficient of variation was 14-20 % for K, ∝6 % for D and 26-44 % for f. The indexes were able to differentiate contrast-enhanced tumour (Wilks' λ = 0.026, p < 10{sup -3}), and performance was greatest with K, followed by f and D. Hybrid DK IVIM imaging is capable of simultaneously measuring cerebral perfusion and diffusion indexes that together may improve brain tumour diagnosis. (orig.)

  16. POOL development status and production experience

    CERN Document Server

    Chytracek, R; Frank, M; Girone, M; Govi, G; Moscicki, J T; Papadopoulos, I; Schmücker, H; Karr, K; Malon, D; Vaniachine, A; Tanenbaum, W; Xie, Z; Barrass, T; Cioffi, C; IT

    2005-01-01

    The pool of persistent objects for LHC (POOL) project, part of the large Hadron collider (LHC) computing grid (LCG), is now entering its third year of active development. POOL provides the baseline persistency framework for three LHC experiments. It is based on a strict component model, insulating experiment software from a variety of storage technologies. This paper gives a brief overview of the POOL architecture, its main design principles and the experience gained with integration into LHC experiment frameworks. It also presents recent developments in the POOL works areas of relational database abstraction and object storage into relational database management systems (RDBMS) systems.

  17. Development of hedge operator based fuzzy divergence measure and its application in segmentation of chronic myelogenous leukocytes from microscopic image of peripheral blood smear.

    Science.gov (United States)

    Ghosh, Madhumala; Chakraborty, Chandan; Konar, Amit; Ray, Ajoy K

    2014-02-01

    This paper introduces a hedge operator based fuzzy divergence measure and its application in segmentation of leukocytes in case of chronic myelogenous leukemia using light microscopic images of peripheral blood smears. The concept of modified discrimination measure is applied to develop the measure of divergence based on Shannon exponential entropy and Yager's measure of entropy. These two measures of divergence are compared with the existing literatures and validated by ground truth images. Finally, it is found that hedge operator based divergence measure using Yager's entropy achieves better segmentation accuracy i.e., 98.29% for normal and 98.15% for chronic myelogenous leukocytes. Furthermore, Jaccard index has been performed to compare the segmented image with ground truth ones where it is found that that the proposed scheme leads to higher Jaccard index (0.39 for normal, 0.24 for chronic myelogenous leukemia).

  18. Can echocardiographic particle image velocimetry correctly detect motion patterns as they occur in blood inside heart chambers? A validation study using moving phantoms

    Directory of Open Access Journals (Sweden)

    Prinz Christian

    2012-06-01

    Full Text Available Abstract Aims To validate Echo Particle Image Velocimetry (PIV Methods High fidelity string and rotating phantoms moving with different speed patterns were imaged with different high-end ultrasound systems at varying insonation angles and frame rates. Images were analyzed for velocity and direction and for complex motion patterns of blood flow with dedicated software. Post-processing was done with MATLAB-based tools (Dflow, JUV, University Leuven. Results Velocity estimation was accurate up to a velocity of 42 cm/s (r = 0.99, p  Conclusion Echo-PIV appears feasible. Velocity estimates are accurate, but the maximal detectable velocity depends strongly on acquisition parameters. Direction estimation works sufficiently, even at higher velocities. Echo-PIV appears to be a promising technical approach to investigate flow patterns by echocardiography.

  19. Experimental investigation of particulate debris spreading in a pool

    Energy Technology Data Exchange (ETDEWEB)

    Konovalenko, A., E-mail: kono@kth.se [Division of Nuclear Power Safety, Royal Institute of Technology (KTH) , Roslagstullsbacken 21, Stockholm 106 91 (Sweden); Basso, S., E-mail: simoneb@kth.se [Division of Nuclear Power Safety, Royal Institute of Technology (KTH) , Roslagstullsbacken 21, Stockholm 106 91 (Sweden); Kudinov, P., E-mail: pkudinov@kth.se [Division of Nuclear Power Safety, Royal Institute of Technology (KTH) , Roslagstullsbacken 21, Stockholm 106 91 (Sweden); Yakush, S.E., E-mail: yakush@ipmnet.ru [Institute for Problems in Mechanics of the Russian Academy of Sciences, Ave. Vernadskogo 101 Bldg 1, Moscow 119526 (Russian Federation)

    2016-02-15

    Termination of severe accident progression by core debris cooling in a deep pool of water under reactor vessel is considered in several designs of light water reactors. However, success of this accident mitigation strategy is contingent upon the effectiveness of heat removal by natural circulation from the debris bed. It is assumed that a porous bed will be formed in the pool in the process of core melt fragmentation and quenching. Debris bed coolability depends on its properties and system conditions. The properties of the bed, including its geometry are the outcomes of the debris bed formation process. Spreading of the debris particles in the pool by two-phase turbulent flows induced by the heat generated in the bed can affect the shape of the bed and thus influence its coolability. The goal of this work is to provide experimental data on spreading of solid particles in the pool by large-scale two-phase flow. The aim is to provide data necessary for understanding of separate effects and for development and validation of models and codes. Validated codes can be then used for prediction of debris bed formation under prototypic severe accident conditions. In PDS-P (Particulate Debris Spreading in the Pool) experiments, air injection at the bottom of the test section is employed as a means to create large-scale flow in the pool in isothermal conditions. The test section is a rectangular tank with a 2D slice geometry, it has fixed width (72 mm), adjustable length (up to 1.5 m) and allows water filling to the depth of up to 1 m. Variable pool length and depth allows studying two-phase circulating flows of different characteristic sizes and patterns. The average void fraction in the pool is determined by video recording and subsequent image processing. Particles are supplied from the top of the facility above the water surface. Results of several series of PDS-P experiments are reported in this paper. The influence of the gas flow rate, pool dimensions, particle density

  20. Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Server, Andres; Nakstad, Per H. [Oslo University Hospital-Ullevaal, Section of Neuroradiology, Department of Radiology and Nuclear Medicine, Oslo (Norway); University of Oslo, Oslo (Norway); Orheim, Tone E.D. [Oslo University Hospital, Interventional Centre, Oslo (Norway); Graff, Bjoern A. [Oslo University Hospital-Ullevaal, Department of Radiology and Nuclear Medicine, Oslo (Norway); Josefsen, Roger [Oslo University Hospital-Ullevaal, Department of Neurosurgery, Oslo (Norway); Kumar, Theresa [Oslo University Hospital-Ullevaal, Department of Pathology, Oslo (Norway)

    2011-05-15

    Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging. A prospective study of 61 patients (40 GBMs and 21 metastases) was performed at 3 T using DSC-MRI. Normalized rCBV and rCBF from tumoral (rCBVt, rCBFt), peri-enhancing region (rCBVe, rCBFe), and by dividing the value in the tumor by the value in the peri-enhancing region (rCBVt/e, rCBFt/e), as well as MVL were calculated. Hemodynamic and histopathologic variables were analyzed statistically and Spearman/Pearson correlations. Receiver operating characteristic curve analysis was performed for each of the variables. The rCBVe, rCBFe, and MVL were significantly greater in GBMs compared with those of metastases. The optimal cutoff value for differentiating GBM from metastasis was 0.80 which implies a sensitivity of 95%, a specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 97% for rCBVe ratio. We found a modest correlation between rCBVt and rCBFt ratios. MVL measurements in GBMs are significantly higher than those in metastases. Statistically, both rCBVe, rCBVt/e and rCBFe, rCBFt/e were useful in differentiating between GBMs and metastases, supporting the hypothesis that perfusion MR imaging can detect infiltration of tumor cells in the peri-enhancing region. (orig.)

  1. Brain imaging and blood biomarker abnormalities in children with autosomal-dominant Alzheimer's disease: A cross-sectional Study

    Science.gov (United States)

    Quiroz, Y.T.; Schultz, A.; Chen, K.; Protas, H.; Brickhouse, M.; Fleisher, A.S.; Langbaum, J.B.; Thiyyagura, P.; Fagan, A.M.; Shah, A.R.; Muniz, M.; Arboleda-Velasquez, JF; Munoz, C.; Garcia, G.; Acosta-Baena, N.; Giraldo, M.; Tirado, V.; Ramirez, D.; Tariot, PN; Dickerson, B.C.; Sperling, R.A.; Lopera, F.; Reiman, E.M.

    2015-01-01

    IMPORTANCE Brain imaging and fluid biomarkers are characterized in children at risk for autosomal dominant Alzheimer disease (ADAD). OBJECTIVE To characterize and compare structural magnetic resonance imaging (MRI), resting-state and task-dependent functional MRI, and plasma amyloid-β (Aβ) measurements in presenilin 1 (PSEN1) E280A mutation–carrying and noncarrying children with ADAD. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional measures of structural and functional MRI and plasma Aβ assays were assessed in 18 PSEN1 E280A carriers and 19 noncarriers aged 9 to 17 years from a Colombian kindred with ADAD. Recruitment and data collection for this study were conducted at the University of Antioquia and the Hospital Pablo Tobon Uribe in Medellin, Colombia, between August 2011 and June 2012. MAIN OUTCOMES AND MEASURES All participants had blood sampling, structural MRI, and functional MRI during associative memory encoding and resting-state and cognitive assessments. Outcome measures included plasma Aβ1-42 concentrations and Aβ1-42:Aβ1-40 ratios, memory encoding–dependent activation changes, resting-state connectivity, and regional gray matter volumes. Structural and functional MRI data were compared using automated brain mapping algorithms and search regions related to AD. RESULTS Similar to findings in adult mutation carriers, in the later preclinical and clinical stages of ADAD, mutation-carrying children were distinguished from control individuals by significantly higher plasma Aβ1-42 levels (mean [SD]: carriers, 18.8 [5.1] pg/mL and noncarriers, 13.1 [3.2] pg/mL; P < .001) and Aβ1-42:Aβ1-40 ratios (mean [SD]: carriers, 0.32 [0.06] and noncarriers, 0.21 [0.03]; P < .001), as well as less memory encoding task–related deactivation in parietal regions (eg, mean [SD] parameter estimates for the right precuneus were −0.590 [0.50] for noncarriers and −0.087 [0.38] for carriers; P < .005 uncorrected). Unlike carriers in the later stages, mutation

  2. Regional cerebral blood flow imaging assessment of brain function reconstruction in elderly hemiplegia patients by body weight support treadmill training

    Institute of Scientific and Technical Information of China (English)

    Wenqing Wang; Yongping Liu; Diqing Wang; Yanshuang Li; Jinglai Hao; Hongwei Zhang; Sheng Bi; Changshui Weng

    2011-01-01

    The mechanism underlying body weight support treadmill training in elderly hemiplegic stroke patients is largely unknown. This study aimed to elucidate the changes of cortical blood flow in seven elderly patients with post-stroke hemiplegia before and after body weight support treadmill training by semi-quantitative analysis of regional cerebral blood flow assessed by single photon emission computed tomography. Body weight support treadmill training for 6 months was effective in improving cerebral blood flow and promoting the walking speed and balance recovery in elderly patients with post-stroke hemiplegia.

  3. Influence of temporal noise on the skin blood flow measurements performed by cooled thermal imaging camera: limit possibilities within each physiological frequency range

    Science.gov (United States)

    Sagaidachnyi, A. A.; Volkov, I. U.; Fomin, A. V.

    2016-04-01

    This paper describes limit possibilities of modern cooled thermal imaging cameras as a tool for estimation of blood flow oscillations at the surface of living body. Skin temperature oscillations, as we assumed, are a consequence of the blood flow oscillations. We considered the temperature sensitivity 0.01-0.02 °C as a typical for the most of modern cooled long wave thermal imaging cameras. Fourier filter used to investigate the temperature signal separately within endothelial, neurogenic, myogenic, respiratory and cardiac frequency ranges. The level of temporal noise has been estimated during measurements of no living body with stabilized temperature ~ 24°C. The level of temperature oscillations has been calculated for the group of healthy subjects within each frequency range. Thus, we were able to determine signal-to-noise ratio within frequency band [0.001, 1] Hz. As a result, we determine that skin temperature oscillations measured by thermal imaging camera with sensitivity 0.02°C have the upper frequency limit ~ 0.2 Hz. In other words, within the respiratory and cardiac frequency ranges of blood flow oscillations the noise level exceeds signal one, and temperature measurements at the skin surface are practically useless. The endothelial, neurogenic and myogenic components of the temperature oscillations contain ~98% of the total spectral power of the signal. We have plot the empirical extrapolated curve of sensitivity of thermal imaging camera vs. frequency of the temperature oscillations. The data analysis shows that measurements of skin temperature oscillations within respiratory and cardiac ranges require the temperature sensitivity at least ~ 0.01°C and 0.001°C, respectively.

  4. Comparison of different protocols for the bovine viral diarrhea virus detection by RT-PCR in pools of whole blood and blood serum artificially contaminated/ Comparação de diferentes protocolos para a detecção do vírus da diarréia viral bovina por RT-PCR em grupos de sangue total e de soro sangüíneo, artificialmente contaminados

    Directory of Open Access Journals (Sweden)

    Amauri A. Alfieri

    2005-06-01

    Full Text Available The RT-PCR technique was optimized and evaluated to detect the 5’ untranslated region of bovine viral diarrhea virus (BVDV from clinical samples that consisted of blood serum and whole blood artificially contaminated with the NADL strain of BVDV. To optimization of technique, the following conditions were evaluated: i two pairs of primers, 103 / 372 (WEINSTOCK et al., 2001 and 324 / 326 (VILCEK et al., 1994, ii four methods of nucleic acid extraction (phenol/chloroform/isoamyl alcohol; silica/guanidine isothiocyanate; a combination of the two previous methods; and TRIzol™ and iii different concentrations and compositions of reagents and time/temperature of the reactions. Between the alternatives tested that resulted in the amplification of the 290 bp product that was easily visualized in ethidium bromide stained 2% agarose gel was that presented the following conditions: i primers 103 and 372; ii initial volume and clinical sample: 50 mL of blood serum; iii extraction of nucleic acid: silica/guanidine isothiocyanate method; iv reverse transcription: 9 mL extracted nucleic acid, 1xPCR buffer (20 mM Tris-HCl pH 8.4 and 50 mM KCl, 1.5 mM MgCl2; 60 units of reverse transcriptase enzyme M-MLV, RNA denaturation at 97°C / 4 min, and reverse transcription at 42°C / 30 min; v PCR: primers 103 / 372 with anneling temperature at 59°C. The utilization of RT-PCR within these optimized conditions allowed the amplification of the BVDV NADL strain (103,56 TCID50 from pools of artificially contaminated blood serum until the dilution 1:160.A técnica da RT-PCR foi otimizada e avaliada para a detecção da região 5’ terminal não-traduzida do genoma do vírus da diarréia viral bovina (BVDV em amostras clínicas de bovinos, constituídas por soro sangüíneo e sangue total, artificialmente contaminadas com a estirpe NADL do BVDV. Para a otimização da técnica foram avaliados: i dois pares de primers, 103 / 372 (WEINSTOCK et al., 2001 e 324 / 326

  5. The impact of high-dose vitamin C on blood glucose testing in ¹⁸F-FDG PET imaging.

    Science.gov (United States)

    Bahr, Rebekah L; Wilson, Don C

    2015-03-01

    Complementary and alternative therapies in addition to standard oncology protocols are commonly sought by cancer patients; however, few patients disclose their complementary treatments to their cancer care team. A lack of communication may result in unforeseen side effects and the potential for some alternative therapies to interfere with or inhibit conventional treatment. High-dose vitamin C therapy, in particular, may lead to an inability to measure a patient's blood glucose level before (18)F-FDG injection for PET/CT scanning. We report a case of a 52-y-old woman referred for (18)F-FDG PET/CT to evaluate the extent of recurrent colorectal cancer. The PET/CT scan immediately followed a single intravenous dose of 25 g of ascorbic acid from her naturopath. A glucometer that applies the glucose oxidase method for measuring fasting blood glucose was used, for which high doses of vitamin C are listed as a contraindication. The high concentration of ascorbic acid in the patient's blood sample interfered with the chemical reaction on the glucose strip, and therefore no blood glucose measurement could be attained. With more patients receiving alternative and complementary cancer therapies, it is important to know what the implications of orthomolecular therapy might be on routine blood glucose testing for (18)F-FDG PET scans. (18)F-FDG is in direct competition with glucose; therefore, elevated blood glucose levels will cause a decrease in (18)F-FDG absorption and may lead to a false-negative scan.

  6. Pooled platelet concentrates: an alternative to single donor apheresis platelets?

    Science.gov (United States)

    Pietersz, R N I

    2009-10-01

    Three types of platelet concentrates (PC) are compared: PC either processed with the platelet-rich plasma (PRP) or the Buffy coat (BC) method from whole blood units and PC obtained by apheresis. Leuko-reduction (LR) pre-storage is advocated to improve quality of the PC during storage and reduce adverse reactions in recipients. Standardization of methods allow preparation of PC with comparable yields of approximately 400 x 10(9) platelets in pooled non-LR-PRP, approximately 370 x 10(9) in pooled LR-BC-PC and in LR apheresis PC the number of platelets can be targeted on 350 x 10(9) or more with devices of various manufacturers. While viral transmission can be prevented by outstanding laboratory tests, the risk of bacterial contamination should be reduced by improved arm disinfection, deviation of the first 20-30 ml of blood and culture or rapid detection assays of the PC pre-issue. In a large prospective multicenter trial no significant difference was observed between cultures of apheresis PC (n = 15,198): 0.09% confirmed positive units versus 0.06% in pooled BC-PC (n = 37,045), respectively. Though platelet activation as measured by CD62 expression may differ in vitro in PC obtained with various apheresis equipment, and also between PC processed with the two whole blood methods there is scarce literature about the clinical impact of these findings. In conclusion the final products of LR-PC derived from whole blood or obtained by apheresis can be comparable, provided the critical steps of the processing method are identified and covered and the process is in control.

  7. [The comparative role of computed tomography and magnetic resonance imaging in the diagnosis of extracapsular spread of malignant lymphomatous masses invading blood vessels].

    Science.gov (United States)

    Dobrovolskiene, Laima; Griniûtë, Rasa

    2003-01-01

    Aim of the study was to search for an optimal method an of investigation in diagnosis of extracapsular spread of the malignant lymphomas and invading the blood vessels. In the period of 1998 to 2002, 81 patients with malignant lymphomas with coverage of neck and body areas were examined in the Department of Tomography of Kaunas University of Medicine Hospital. It was performed by computed tomography (CT) and magnetic resonance imaging (MRI), with or without iv. application of contrast media. The data were processed with SPSS 10.1 (Statistical package for Social Sciences 10.1 for Windows), including application of chi(2), t-test. Specificity, sensitivity and diagnostic accuracy of CT and MRI methods were calculated and compared according to recommendations by Gefland D. W. and Ott D. J., 1985. Diagnosis of extracapsular spread of the lymphomatous tissue and invading the blood vessels was best performed by MR method (specificity, sensitivity, accuracy in this case 91-95%). Bolus CT angiography because of low resolution in the range of soft tissues, insufficient opacification of blood vessels with contrast medium and differences in blood flow was not informative enough (specificity, sensitivity, accuracy in this case 80-85%).

  8. In vivo two-photon imaging of axonal dieback, blood flow, and calcium influx with methylprednisolone therapy after spinal cord injury.

    Science.gov (United States)

    Tang, Peifu; Zhang, Yiling; Chen, Chao; Ji, Xinran; Ju, Furong; Liu, Xingyu; Gan, Wen-Biao; He, Zhigang; Zhang, Shengxiang; Li, Wei; Zhang, Lihai

    2015-05-19

    Severe spinal cord injury (SCI) can cause neurological dysfunction and paralysis. However, the early dynamic changes of neurons and their surrounding environment after SCI are poorly understood. Although methylprednisolone (MP) is currently the standard therapeutic agent for treating SCI, its efficacy remains controversial. The purpose of this project was to investigate the early dynamic changes and MP's efficacy on axonal damage, blood flow, and calcium influx into axons in a mouse SCI model. YFP H-line and Thy1-GCaMP transgenic mice were used in this study. Two-photon microscopy was used for imaging of axonal dieback, blood flow, and calcium influx post-injury. We found that MP treatment attenuated progressive damage of axons, increased blood flow, and reduced calcium influx post-injury. Furthermore, microglia/macrophages accumulated in the lesion site after SCI and expressed the proinflammatory mediators iNOS, MCP-1 and IL-1β. MP treatment markedly inhibited the accumulation of microglia/macrophages and reduced the expression of the proinflammatory mediators. MP treatment also improved the recovery of behavioral function post-injury. These findings suggest that MP exerts a neuroprotective effect on SCI treatment by attenuating progressive damage of axons, increasing blood flow, reducing calcium influx, and inhibiting the accumulation of microglia/macrophages after SCI.

  9. Improved swimming pool achieves higher reproducibility and sensitivity to effect of food components as ergogenic AIDS.

    Science.gov (United States)

    Ishihara, Kengo; Yamada, Ayumi; Mita, Yukiko; Goto, Ayako; Ishimi, Tomoe; Mabuchi, Haruko; Inoue, Kazuo; Fushiki, Tohru; Yasumoto, Kyoden

    2009-06-01

    A previously developed current swimming pool for mice has been used to evaluate many food components that enhance endurance exercise performance. In this article, to improve reproducibility, reliability and sensitivity of this assay system, we improved the spout part to generate a uniform current and divided the pool into six lanes to avoid physical interference between swimming mice. The stability of the current flow was assessed by measuring the surface current speed and water volume from the spout part. Maximum swimming times of ddY and BALB/c mice were measured to assess the reproducibility of the maximum swimming time. The improvement in sensitivity compared to the original equipment was estimated under three physiological conditions: low carbohydrate diet feeding, low blood hemoglobin level, and carbohydrate supplementation during exercise. The new spout part improved uniformity and quick adjustment of surface current, yielding an increase of workload in a stepwise manner during swimming. Exercise workload was increased in proportion to surface current speed, as evidenced by cadence of kicks and serum lactic acid levels. The improved swimming pool showed higher reproducibility of swimming time until fatigue (pswimming time was improved in the swimming pool. The improved swimming pool yielded higher sensitivity for low carbohydrate diet feeding (pswimming pool. The improvement of the swimming pool achieved higher sensitivity and reproducibility in assessing various diet and food components compared to the original swimming pool.

  10. Measurements of diagnostic examination performance and correlation analysis using microvascular leakage, cerebral blood volume, and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

    Energy Technology Data Exchange (ETDEWEB)

    Server, Andres; Nakstad, Per H. [Oslo University Hospital-Ullevaal, Section of Neuroradiology, Department of Radiology and Nuclear Medicine, Oslo (Norway); University of Oslo, Oslo (Norway); Graff, Bjoern A. [Oslo University Hospital-Ullevaal, Department of Radiology and Nuclear Medicine, Oslo (Norway); Orheim, Tone E.D.; Gadmar, Oeystein B. [Oslo University Hospital, Interventional Centre, Oslo (Norway); Schellhorn, Till [Oslo University Hospital-Ullevaal, Section of Neuroradiology, Department of Radiology and Nuclear Medicine, Oslo (Norway); Josefsen, Roger [Oslo University Hospital-Ullevaal, Department of Neurosurgery, Oslo (Norway)

    2011-06-15

    To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades. A prospective study of 79 patients with cerebral glial tumors underwent DSC-MR imaging. Normalized relative CBV (rCBV) and relative CBF (rCBF) from tumoral (rCBVt and rCBFt), peri-enhancing region (rCBVe and rCBFe), and the value in the tumor divided by the value in the peri-enhancing region (rCBVt/e and rCBFt/e), as well as MVL, expressed as the leakage coefficient K{sub 2} were calculated. Hemodynamic variables and tumor grades were analyzed statistically and with Pearson correlations. Receiver operating characteristic (ROC) curve analyses were also performed for each of the variables. The differences in rCBVt and the maximum MVL (MVL{sub max}) values were statistically significant among all tumor grades. Correlation analysis using Pearson was as follows: rCBVt and tumor grade, r = 0.774; rCBFt and tumor grade, r = 0.417; MVL{sub max} and tumor grade, r = 0.559; MVL{sub max} and rCBVt, r = 0.440; MVL{sub max} and rCBFt, r = 0.192; and rCBVt and rCBFt, r = 0.605. According to ROC analyses for distinguishing tumor grade, rCBVt showed the largest areas under ROC curve (AUC), except for grade III from IV. Both rCBVt and MVL{sub max} showed good discriminative power in distinguishing all tumor grades. rCBVt correlated strongly with tumor grade; the correlation between MVL{sub max} and tumor grade was moderate. (orig.)

  11. Optical coherence tomography angiography offers comprehensive evaluation of skin optical clearing in vivo by quantifying optical properties and blood flow imaging simultaneously

    Science.gov (United States)

    Guo, Li; Shi, Rui; Zhang, Chao; Zhu, Dan; Ding, Zhihua; Li, Peng

    2016-08-01

    Tissue optical clearing (TOC) is helpful for reducing scattering and enhancing the penetration depth of light, and shows promising potential in optimizing optical imaging performances. A mixture of fructose with PEG-400 and thiazone (FPT) is used as an optical clearing agent in mouse dorsal skin and evaluated with OCT angiography (Angio-OCT) by quantifying optical properties and blood flow imaging simultaneously. It is observed that FPT leads to an improved imaging performance for the deeper tissues. The imaging performance improvement is most likely caused by the FPT-induced dehydration of skin, and the reduction of scattering coefficient (more than ˜40.5%) and refractive-index mismatching (more than ˜25.3%) in the superficial (epidermal, dermal, and hypodermal) layers. A high correlation (up to ˜90%) between the relative changes in refractive-index mismatching and Angio-OCT signal strength is measured. The optical clearing rate is ˜5.83×10-5 cm/s. In addition, Angio-OCT demonstrates enhanced performance in imaging cutaneous hemodynamics with satisfactory spatiotemporal resolution and contrast when combined with TOC, which exhibits a powerful practical application in studying microcirculation.

  12. Image acquisition and interpretation criteria for {sup 99m}Tc-HMPAO-labelled white blood cell scintigraphy: results of a multicentre study

    Energy Technology Data Exchange (ETDEWEB)

    Erba, Paola A. [University of Pisa Medical School (Italy). Regional Center of Nuclear Medicine; Glaudemans, Andor W.J.M.; Dierckx, Rudi A.J.O. [University Medical Center Groningen (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Veltman, Niels C. [Jeroen Bosch Hospital, ' s-Hertogenbosch (Netherlands). Dept. of Nuclear Medicine; Sollini, Martina [Arcisprdale S. Maria Nuova - IRCCS, Reggio Emilia (Italy). Nuclear Medicine Unit; Pacilio, Marta; Galli, Filippo [Sapienza Univ., Rome (Italy). Nuclear Medicine Unit; Signore, Alberto [University Medical Center Groningen (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Sapienza Univ., Rome (Italy). Nuclear Medicine Unit; Sapienza Univ., Rome (Italy). Ospedale S. Andrea Medicina Nucleare

    2014-04-15

    There is no consensus yet on the best protocol for planar image acquisition and interpretation of radiolabelled white blood cell (WBC) scintigraphy. This may account for differences in reported diagnostic accuracy amongst different centres. This was a multicentre retrospective study analysing 235 WBC scans divided into two groups. The first group of scans (105 patients) were acquired with a fixed-time acquisition protocol and the second group (130 patients) were acquired with a decay time-corrected acquisition protocol. Planar images were interpreted both qualitatively and semiquantitatively. Three blinded readers analysed the images. The most accurate imaging acquisition protocol comprised image acquisition at 3 - 4 h and at 20 - 24 h in time mode with acquisition times corrected for isotope decay. Using this protocol, visual analysis had high sensitivity and specificity in the diagnosis of infection. Semiquantitative analysis could be used in doubtful cases, with no cut-off for the percentage increase in radiolabelled WBC over time, as a criterion to define a positive scan. (orig.)

  13. Radioisotope Power System Pool Concept

    Science.gov (United States)

    Rusick, Jeffrey J.; Bolotin, Gary S.

    2015-01-01

    Advanced Radioisotope Power Systems (RPS) for NASA deep space science missions have historically used static thermoelectric-based designs because they are highly reliable, and their radioisotope heat sources can be passively cooled throughout the mission life cycle. Recently, a significant effort to develop a dynamic RPS, the Advanced Stirling Radioisotope Generator (ASRG), was conducted by NASA and the Department of Energy, because Stirling based designs offer energy conversion efficiencies four times higher than heritage thermoelectric designs; and the efficiency would proportionately reduce the amount of radioisotope fuel needed for the same power output. However, the long term reliability of a Stirling based design is a concern compared to thermoelectric designs, because for certain Stirling system architectures the radioisotope heat sources must be actively cooled via the dynamic operation of Stirling converters throughout the mission life cycle. To address this reliability concern, a new dynamic Stirling cycle RPS architecture is proposed called the RPS Pool Concept.

  14. Paramagnetic perfluorocarbon-filled albumin-(Gd-DTPA) microbubbles for the induction of focused-ultrasound-induced blood-brain barrier opening and concurrent MR and ultrasound imaging

    Science.gov (United States)

    Liao, Ai-Ho; Liu, Hao-Li; Su, Chia-Hao; Hua, Mu-Yi; Yang, Hung-Wei; Weng, Yu-Ting; Hsu, Po-Hung; Huang, Sheng-Min; Wu, Shih-Yen; Wang, Hsin-Ell; Yen, Tzu-Chen; Li, Pai-Chi

    2012-05-01

    This paper presents new albumin-shelled Gd-DTPA microbubbles (MBs) that can concurrently serve as a dual-modality contrast agent for ultrasound (US) imaging and magnetic resonance (MR) imaging to assist blood-brain barrier (BBB) opening and detect intracerebral hemorrhage (ICH) during focused ultrasound brain drug delivery. Perfluorocarbon-filled albumin-(Gd-DTPA) MBs were prepared with a mean diameter of 2320 nm and concentration of 2.903×109 MBs ml-1 using albumin-(Gd-DTPA) and by sonication with perfluorocarbon (C3F8) gas. The albumin-(Gd-DTPA) MBs were then centrifuged and the procedure was repeated until the free Gd3+ ions were eliminated (which were detected by the xylenol orange sodium salt solution). The albumin-(Gd-DTPA) MBs were also characterized and evaluated both in vitro and in vivo by US and MR imaging. Focused US was used with the albumin-(Gd-DTPA) MBs to induce disruption of the BBB in 18 rats. BBB disruption was confirmed with contrast-enhanced T1-weighted turbo-spin-echo sequence MR imaging. Heavy T2*-weighted 3D fast low-angle shot sequence MR imaging was used to detect ICH. In vitro US imaging experiments showed that albumin-(Gd-DTPA) MBs can significantly enhance the US contrast in T1-, T2- and T2*-weighted MR images. The r1 and r2 relaxivities for Gd-DTPA were 7.69 and 21.35 s-1mM-1, respectively, indicating that the MBs represent a positive contrast agent in T1-weighted images. In vivo MR imaging experiments on 18 rats showed that focused US combined with albumin-(Gd-DTPA) MBs can be used to both induce disruption of the BBB and detect ICH. To compare the signal intensity change between pure BBB opening and BBB opening accompanying ICH, albumin-(Gd-DTPA) MB imaging can provide a ratio of 5.14 with significant difference (p = 0.026), whereas Gd-DTPA imaging only provides a ratio of 2.13 and without significant difference (p = 0.108). The results indicate that albumin-(Gd-DTPA) MBs have potential as a US/MR dual-modality contrast agent for

  15. Complementary tumor vascularity imaging in a single PET-CT routine using FDG early dynamic blood flow and contrast-enhanced CT texture analysis

    Science.gov (United States)

    Carmi, Raz; Yefremov, Nikolay; Bernstine, Hanna; Groshar, David

    2014-03-01

    A feasibility study of improved PET-CT tumor imaging approach is presented. A single PET-CT routine includes three different techniques: 18F-FDG early dynamic blood flow intended for perfusion assessment; standard late 18F-FDG uptake; and high-resolution contrast-enhanced CT enabling tissue texture analysis. Both PET protocols utilize the same single standard radiotracer dose administration. Quantitative volumetric arterial perfusion maps are derived from the reconstructed dynamic PET images corresponding to successive acquisition time intervals of 3 seconds only. For achieving high accuracy, the analysis algorithm differentiates the first-pass arterial flow from other interfering dynamic effects, and a noise reduction scheme based on adaptive total-variation minimization aims to provide appreciable quantitative map in physical conditions of high noise and low spatial resolution. The CT texture analysis comprises a practical and robust method for generating volumetric tissue irregularity maps. A local map value is represented by the entropy function which is derived from a weighted co-occurrence matrix histogram of the corresponding image voxel three-dimensional vicinity. Unique entropy scaling scheme and parameter optimization process, as well as appropriate scaling for varying image noise levels and contrast agent concentrations, improve the results toward quantitative absolute measure with respect to diverse scanning conditions and key analysis parameters. Representative imaging results are demonstrated on several clinical cases involving different organs and cancer types. In these cases, significant tumor characterization relative to the normal surrounding tissues is seen on the quantitative maps of all three imaging techniques. This proof of concept can lead the way to a new practical diagnostic imaging application.

  16. Correlation between single-trial visual evoked potentials and the blood oxygenation level dependent response in simultaneously recorded electroencephalography-functional magnetic resonance imaging

    DEFF Research Database (Denmark)

    Fuglø, Dan; Pedersen, Henrik; Rostrup, Egill;

    2012-01-01

    To compare different electroencephalography (EEG)-based regressors and their ability to predict the simultaneously recorded blood oxygenation level dependent response during blocked visual stimulation, simultaneous EEG-functional magnetic resonance imaging in 10 healthy volunteers was performed...... in different occipital and extraoccipital cortical areas not explained by the boxcar regressor. The results suggest that the P1-N2 regressor is the best EEG-based regressor to model the visual paradigm, but when looking for additional effects like habituation or attention modulation that cannot be modeled...

  17. Smartphone-Imaged HIV-1 Reverse-Transcription Loop-Mediated Isothermal Amplification (RT-LAMP on a Chip from Whole Blood

    Directory of Open Access Journals (Sweden)

    Gregory L. Damhorst

    2015-09-01

    Full Text Available Viral load measurements are an essential tool for the long-term clinical care of human immunodeficiency virus (HIV-positive individuals. The gold standards in viral load instrumentation, however, are still too limited by their size, cost, and sophisticated operation for these measurements to be ubiquitous in remote settings with poor healthcare infrastructure, including parts of the world that are disproportionately affected by HIV infection. The challenge of developing a point-of-care platform capable of making viral load more accessible has been frequently approached but no solution has yet emerged that meets the practical requirements of low cost, portability, and ease-of-use. In this paper, we perform reverse-transcription loop-mediated isothermal amplification (RT-LAMP on minimally processed HIV-spiked whole blood samples with a microfluidic and silicon microchip platform, and perform fluorescence measurements with a consumer smartphone. Our integrated assay shows amplification from as few as three viruses in a ~ 60 nL RT-LAMP droplet, corresponding to a whole blood concentration of 670 viruses per μL of whole blood. The technology contains greater power in a digital RT-LAMP approach that could be scaled up for the determination of viral load from a finger prick of blood in the clinical care of HIV-positive individuals. We demonstrate that all aspects of this viral load approach, from a drop of blood to imaging the RT-LAMP reaction, are compatible with lab-on-a-chip components and mobile instrumentation.

  18. The effect of aging on atherosclerotic plaque inflammation and molecular calcification: A PET CT imaging study

    DEFF Research Database (Denmark)

    Blomberg, Björn; Thomassen, Anders; Simonsen, Jane Angel;

    cardiovascular risk factors were prospectively assessed by 18F-FDG (inflammation) and sodium 18F-fluoride (18F-NaF) (molecular calcification) PET CT imaging. Global aortic uptake of 18F-FDG and 18F-NaF was determined semi-quantitatively by calculating the average blood pool corrected standardized uptake value (cSUV......) [Mean SUVAORTA - Mean SUVBLOOD POOL]. Furthermore, the average maximum 18F-NaF cSUV was determined in the coronary arteries. Calculating regression and correlation coefficients summarized the data. Results: A quadratic relationship was observed between aging and aortic 18F-FDG avidity. A second order...

  19. New Technique for Automatic Segmentation of Blood Vessels in CT Scan Images of Liver Based on Optimized Fuzzy C-Means Method

    Directory of Open Access Journals (Sweden)

    Katayoon Ahmadi

    2016-01-01

    Full Text Available Automatic segmentation of medical CT scan images is one of the most challenging fields in digital image processing. The goal of this paper is to discuss the automatic segmentation of CT scan images to detect and separate vessels in the liver. The segmentation of liver vessels is very important in the liver surgery planning and identifying the structure of vessels and their relationship to tumors. Fuzzy C-means (FCM method has already been proposed for segmentation of liver vessels. Due to classical optimization process, this method suffers lack of sensitivity to the initial values of ​​class centers and segmentation of local minima. In this article, a method based on FCM in conjunction with genetic algorithms (GA is applied for segmentation of liver’s blood vessels. This method was simulated and validated using 20 CT scan images of the liver. The results showed that the accuracy, sensitivity, specificity, and CPU time of new method in comparison with FCM algorithm reaching up to 91%, 83.62, 94.11%, and 27.17 were achieved, respectively. Moreover, selection of optimal and robust parameters in the initial step led to rapid convergence of the proposed method. The outcome of this research assists medical teams in estimating disease progress and selecting proper treatments.

  20. Steady State Vapor Bubble in Pool Boiling

    Science.gov (United States)

    Zou, An; Chanana, Ashish; Agrawal, Amit; Wayner, Peter C.; Maroo, Shalabh C.

    2016-02-01

    Boiling, a dynamic and multiscale process, has been studied for several decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which occurs over millisecond time-span, makes it extremely challenging to study near-surface interfacial characteristics of a single bubble. Here, we create a steady-state vapor bubble that can remain stable for hours in a pool of sub-cooled water using a femtosecond laser source. The stability of the bubble allows us to measure the contact-angle and perform in-situ imaging of the contact-line region and the microlayer, on hydrophilic and hydrophobic surfaces and in both degassed and regular (with dissolved air) water. The early growth stage of vapor bubble in degassed water shows a completely wetted bubble base with the microlayer, and the bubble does not depart from the surface due to reduced liquid pressure in the microlayer. Using experimental data and numerical simulations, we obtain permissible range of maximum heat transfer coefficient possible in nucleate boiling and the width of the evaporating layer in the contact-line region. This technique of creating and measuring fundamental characteristics of a stable vapor bubble will facilitate rational design of nanostructures for boiling enhancement and advance thermal management in electronics.

  1. Free-breathing black-blood CINE fast-spin echo imaging for measuring abdominal aortic wall distensibility: A feasibility study.

    Science.gov (United States)

    Lin, Jyh-Miin; Patterson, Andrew; Chao, Tzu-Cheng; Zhu, Chengcheng; Chang, Hing-Chiu; Mendes, Jason; Chung, Hsiao-Wen; Gillard, Jonathan; Graves, Martin

    2017-03-22

    The paper reports a free-breathing black-blood CINE fast-spin echo (FSE) technique for measuring abdominal aortic wall motion. The free-breathing CINE FSE includes the following MR techniques: 1) variable-density sampling with fast iterative reconstruction; 2) inner-volume imaging; and 3) a blood-suppression preparation pulse. The proposed technique was evaluated in eight healthy subjects. The inner-volume imaging significantly reduced the intraluminal artifacts of respiratory motion (p = 0.015). The quantitative measurements were a diameter of 16.3 ± 2.8 mm and wall distensibility of 2.0 ± 0.4 mm (12.5 ± 3.4%) and 0.7 ± 0.3 mm (4.1 ± 1.0%) for the anterior and posterior walls, respectively. The cyclic cross-sectional distensibility was 35 ± 15% greater in the systolic phase than in the diastolic phase. In conclusion, we developed a feasible CINE FSE method to measure the motion of the abdominal aortic wall, which will enable clinical scientists to study the elasticity of the abdominal aorta.

  2. Monitoring stroke progression: in vivo imaging of cortical perfusion, blood-brain barrier permeability and cellular damage in the rat photothrombosis model.

    Science.gov (United States)

    Schoknecht, Karl; Prager, Ofer; Vazana, Udi; Kamintsky, Lyn; Harhausen, Denise; Zille, Marietta; Figge, Lena; Chassidim, Yoash; Schellenberger, Eyk; Kovács, Richard; Heinemann, Uwe; Friedman, Alon

    2014-11-01

    Focal cerebral ischemia is among the main causes of death and disability worldwide. The ischemic core often progresses, invading the peri-ischemic brain; however, assessing the propensity of the peri-ischemic brain to undergo secondary damage, understanding the underlying mechanisms, and adjusting treatment accordingly remain clinically unmet challenges. A significant hallmark of the peri-ischemic brain is dysfunction of the blood-brain barrier (BBB), yet the role of disturbed vascular permeability in stroke progression is unclear. Here we describe a longitudinal in vivo fluorescence imaging approach for the evaluation of cortical perfusion, BBB dysfunction, free radical formation and cellular injury using the photothrombosis vascular occlusion model in male Sprague Dawley rats. Blood-brain barrier dysfunction propagated within the peri-ischemic brain in the first hours after photothrombosis and was associated with free radical formation and cellular injury. Inhibiting free radical signaling significantly reduced progressive cellular damage after photothrombosis, with no significant effect on blood flow and BBB permeability. Our approach allows a dynamic follow-up of cellular events and their response to therapeutics in the acutely injured cerebral cortex.

  3. Monitoring hypoxia induced changes in cochlear blood flow and hemoglobin concentration using a combined dual-wavelength laser speckle contrast imaging and Doppler optical microangiography system.

    Directory of Open Access Journals (Sweden)

    Roberto Reif

    Full Text Available A synchronized dual-wavelength laser speckle contrast imaging (DWLSCI system and a Doppler optical microangiography (DOMAG system was developed to determine several ischemic parameters in the cochlea due to a systemic hypoxic challenge. DWLSCI can obtain two-dimensional data, and was used to determine the relative changes in cochlear blood flow, and change in the concentrations of oxyhemoglobin (HbO, deoxyhemoglobin (Hb and total hemoglobin (HbT in mice. DOMAG can obtain three-dimensional data, and was used to determine the changes in cochlear blood flow with single vessel resolution. It was demonstrated that during a hypoxic challenge there was an increase in the concentrations of Hb, a decrease in the concentrations of HbO and cochlear blood flow, and a slight decrease in the concentration of HbT. Also, the rate of change in the concentrations of Hb and HbO was quantified during and after the hypoxic challenge. The ability to simultaneously measure these ischemic parameters with high spatio-temporal resolution will allow the detailed quantitative analysis of several hearing disorders, and will be useful for diagnosing and developing treatments.

  4. Fragment structure from vapor explosions during the impact of molten metal droplets into a liquid pool

    Science.gov (United States)

    Kouraytem, Nadia; Li, Er Qiang; Vakarelski, Ivan Uriev; Thoroddsen, Sigurdur

    2015-11-01

    High-speed video imaging is used in order to look at the impact of a molten metal drop falling into a liquid pool. The interaction regimes are three: film boiling, nucleate boiling or vapor explosion. Following the vapor explosion, the metal fragments and different textures are observed. It was seen that, using a tin alloy, a porous structure results whereas using a distinctive eutectic metal, Field's metal, micro beads are formed. Different parameters such as the metal type, molten metal temperature, pool surface tension and pool boiling temperature have been altered in order to assess the role they play on the explosion dynamics and the molten metal's by product.

  5. Sulfur cycling in two Dutch moorland pools.

    NARCIS (Netherlands)

    Marnette, E.C.L.

    1993-01-01

    Due to atmospheric acid deposition, the chemistry of many moorland pools has changed, resulting in changes in their fauna and flora. Most moorland pools are sensitive to acid loading because underlying and surrounding soils are low in chemical buffering capacity. Biological processes in the sediment

  6. Analysis of Systolic Backflow and Secondary Helical Blood Flow in the Ascending Aorta Using Vector Flow Imaging

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Møller-Sørensen, Hasse; Kjaergaard, Jesper

    2016-01-01

    Secondary rotational flow and systolic backflow are seen in the ascending aorta and, in this study, were analyzed with the vector velocity method transverse oscillation. Twenty-five patients were scanned intra-operatively, and the vector velocities were related to estimates of transesophageal...... that backflow is injurious and that secondary flow is a normal flow phenomenon. The study also shows that transverse oscillation can provide new information on blood flow in the ascending aorta....

  7. Diagnostic imaging of musculoskeletal infection. Roentgenography; Gallium, indium-labeled white blood cell, gammaglobulin, bone scintigraphy; and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, W.A.; Alavi, A. (Hospital of the University of Pennsylvania, Philadelphia (USA))

    1991-07-01

    A great deal of effort has been made to evaluate and define the role of various diagnostic imaging techniques in various clinical settings that complicate the diagnosis of osteomyelitis. Except possibly in neonates, bone scintigraphy remains generally recommended when there has been no previous osseous involvement. In other cases of chronic disease, previous fracture or trauma, prosthesis, and diabetic foot, In-WBC scintigraphy is generally accepted as an appropriate imaging technique. MRI will play an increasingly important role in diagnosing osteomyelitis and may prove to be an important adjunct in these cases. Research continues to improve our current diagnostic armamentarium. In-IgG appears to avoid practical deficiencies encountered with 67Ga and In-WBC; it remains to be seen what role this agent will play in routine clinical practice. All agents to date image inflammation, not infection, and most require delayed imaging sessions, usually at 24 hours. These shortcomings necessitate further research to develop new radiotracers that can provide useful images within several hours and that are specific for infection, perhaps ultimately delineating the particular microorganism involved.84 references.

  8. Oblique drop impact onto a deep liquid pool

    CERN Document Server

    Gielen, Marise V; Benschop, Jos; Riepen, Michel; Voronina, Victoria; Lohse, Detlef; Snoeijer, Jacco H; Versluis, Michel; Gelderblom, Hanneke

    2016-01-01

    Oblique impact of drops on a solid or liquid surface is frequently observed in nature. Most studies on drop impact and splashing, however, focus on perpendicular impact. Here, we study oblique impact onto a deep liquid pool, where we quantify the splashing threshold, maximal cavity dimensions and cavity collapse by high-speed imaging above and below the water surface. Three different impact regimes are identified: smooth deposition onto the pool, splashing in the direction of impact only, and splashing in all directions. We provide scaling arguments that delineate these regimes by accounting for drop impact angle and Weber number. The angle of the axis of the cavity created below the water surface follows the impact angle of the drop independent of the Weber number, while cavity depth and its displacement with respect to the impact position depend on the Weber number. Weber number dependency of both the cavity depth and displacement is modeled using an energy argument.

  9. Pool scrubbing models for iodine components

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, K. [Battelle Ingenieurtechnik GmbH, Eschborn (Germany)

    1996-12-01

    Pool scrubbing is an important mechanism to retain radioactive fission products from being carried into the containment atmosphere or into the secondary piping system. A number of models and computer codes has been developed to predict the retention of aerosols and fission product vapours that are released from the core and injected into water pools of BWR and PWR type reactors during severe accidents. Important codes in this field are BUSCA, SPARC and SUPRA. The present paper summarizes the models for scrubbing of gaseous Iodine components in these codes, discusses the experimental validation, and gives an assessment of the state of knowledge reached and the open questions which persist. The retention of gaseous Iodine components is modelled by the various codes in a very heterogeneous manner. Differences show up in the chemical species considered, the treatment of mass transfer boundary layers on the gaseous and liquid sides, the gas-liquid interface geometry, calculation of equilibrium concentrations and numerical procedures. Especially important is the determination of the pool water pH value. This value is affected by basic aerosols deposited in the water, e.g. Cesium and Rubidium compounds. A consistent model requires a mass balance of these compounds in the pool, thus effectively coupling the pool scrubbing phenomena of aerosols and gaseous Iodine species. Since the water pool conditions are also affected by drainage flow of condensate water from different regions in the containment, and desorption of dissolved gases on the pool surface is determined by the gas concentrations above the pool, some basic limitations of specialized pool scrubbing codes are given. The paper draws conclusions about the necessity of coupling between containment thermal-hydraulics and pool scrubbing models, and proposes ways of further simulation model development in order to improve source term predictions. (author) 2 tabs., refs.

  10. Corrections of arterial input function for dynamic H215O PET to assess perfusion of pelvic tumours: arterial blood sampling versus image extraction

    Science.gov (United States)

    Lüdemann, L.; Sreenivasa, G.; Michel, R.; Rosner, C.; Plotkin, M.; Felix, R.; Wust, P.; Amthauer, H.

    2006-06-01

    Assessment of perfusion with 15O-labelled water (H215O) requires measurement of the arterial input function (AIF). The arterial time activity curve (TAC) measured using the peripheral sampling scheme requires corrections for delay and dispersion. In this study, parametrizations with and without arterial spillover correction for fitting of the tissue curve are evaluated. Additionally, a completely noninvasive method for generation of the AIF from a dynamic positron emission tomography (PET) acquisition is applied to assess perfusion of pelvic tumours. This method uses a volume of interest (VOI) to extract the TAC from the femoral artery. The VOI TAC is corrected for spillover using a separate tissue TAC and for recovery by determining the recovery coefficient on a coregistered CT data set. The techniques were applied in five patients with pelvic tumours who underwent a total of 11 examinations. Delay and dispersion correction of the blood TAC without arterial spillover correction yielded in seven examinations solutions inconsistent with physiology. Correction of arterial spillover increased the fitting accuracy and yielded consistent results in all patients. Generation of an AIF from PET image data was investigated as an alternative to arterial blood sampling and was shown to have an intrinsic potential to determine the AIF noninvasively and reproducibly. The AIF extracted from a VOI in a dynamic PET scan was similar in shape to the blood AIF but yielded significantly higher tissue perfusion values (mean of 104.0 ± 52.0%) and lower partition coefficients (-31.6 ± 24.2%). The perfusion values and partition coefficients determined with the VOI technique have to be corrected in order to compare the results with those of studies using a blood AIF.

  11. Clinical Value of Radionuclide Cardiac Blood-pool Imaging in Coronary Heart Disease%放射性核素心血池显像测定冠心病患者左室功能的价值

    Institute of Scientific and Technical Information of China (English)

    韩学斌; 李海英; 冯贵生

    2005-01-01

    目的:探讨放射性核素心血池显像测定冠心病(CHD)患者左室功能的临床价值.方法:使用Elscint公司SP-6型SPECT,采用体内法标记红细胞平衡法测定,应用Elscint公司心功能处理程序对数据处理,产生如下的心功能参数:LVEF(左室射血分数)、PER(高峰射血率)、PFR(高峰充盈率).结果:对照组各项指标与文献报道结果相近,AP组PER、PFR与对照组比较差异有显著性(P<0.05);LVEF与对照组比较差异无显著性(P>0.05).MI组LVEF、PER、PFR与对照组AP组比较差异均有显著性(P<0.01);CHD患者中有18例(37.5%)EF值下降,而PFR为28例(58.33%),后者检出率高于前者,差异有显著性(P<0.05),LVEF正常患者,PFR降低者12例(40%).结论:PFR对于反映CHD患者左心功能损害较LVEF更灵敏,且可反映患者心肌缺血的严重程度,对于临床上疑为CHD的患者,如果左室收缩功能正常,而舒张功能降低,有助于CHD的诊断.

  12. Evaluation of tumour hypoxia during radiotherapy using [{sup 18}F]HX4 PET imaging and blood biomarkers in patients with head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zegers, Catharina M.L.; Hoebers, Frank J.P.; Elmpt, Wouter van; Oellers, Michel C.; Eekers, Danielle; Balmaekers, Leo; Arts-Pechtold, Marlies; Lambin, Philippe [Maastricht University Medical Centre, Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Bons, Judith A. [Maastricht University Medical Centre, Central Diagnostic Laboratory, Maastricht (Netherlands); Troost, Esther G.C. [Maastricht University Medical Centre, Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Helmholtz Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, OncoRay, Department of Radiation Oncology, Medical Faculty and University Hospital Carl Gustav Carus, Dresden (Germany); Mottaghy, Felix M. [Maastricht University Medical Centre, Department of Nuclear Medicine, Maastricht (Netherlands); RWTH Aachen University, University Hospital, Department of Nuclear Medicine, Aachen (Germany)

    2016-11-15

    Increased tumour hypoxia is associated with a worse overall survival in patients with head and neck squamous cell carcinoma (HNSCC). The aims of this study were to evaluate treatment-associated changes in [{sup 18}F]HX4-PET, hypoxia-related blood biomarkers, and their interdependence. [{sup 18}F]HX4-PET/CT scans of 20 patients with HNSCC were acquired at baseline and after ±20 Gy of radiotherapy. Within the gross-tumour-volumes (GTV; primary and lymph nodes), mean and maximum standardized uptake values, the hypoxic fraction (HF) and volume (HV) were calculated. Also, the changes in spatial uptake pattern were evaluated using [{sup 18}F]HX4-PET/CT imaging. For all patients, the plasma concentration of CAIX, osteopontin and VEGF was assessed. At baseline, tumour hypoxia was detected in 69 % (22/32) of the GTVs. During therapy, we observed a significant decrease in all image parameters. The HF decreased from 21.7 ± 19.8 % (baseline) to 3.6 ± 10.0 % (during treatment; P < 0.001). Only two patients had a HV > 1 cm{sup 3} during treatment, which was located for >98 % within the baseline HV. During treatment, no significant changes in plasma CAIX or VEGF were observed, while osteopontin was increased. [{sup 18}F]HX4-PET/CT imaging allows monitoring changes in hypoxia during (chemo)radiotherapy whereas the blood biomarkers were not able to detect a treatment-associated decrease in hypoxia. (orig.)

  13. Laser speckle imaging identification of increases in cortical microcirculatory blood flow induced by motor activity during awake craniotomy ; Clinical article

    NARCIS (Netherlands)

    E. Klijn (Elko); M.E.J.L. Hulscher (Marlies); R.K. Balvers (Rutger); W.P.J. Holland (Wim); J. Bakker (Jan); A.J.P.E. Vincent (Arnoud); C.M.F. Dirven (Clemens); C. Ince (Can)

    2013-01-01

    textabstractObject. The goal of awake neurosurgery is to maximize resection of brain lesions with minimal injury to functional brain areas. Laser speckle imaging (LSI) is a noninvasive macroscopic technique with high spatial and temporal resolution used to monitor changes in capillary perfusion. In

  14. Functional Magnetic Resonance Imaging Measures of Blood Flow Patterns in the Human Auditory Cortex in Response to Sound.

    Science.gov (United States)

    Huckins, Sean C.; Turner, Christopher W.; Doherty, Karen A.; Fonte, Michael M.; Szeverenyi, Nikolaus M.

    1998-01-01

    This study examined the feasibility of using functional magnetic resonance imaging (fMRI) in auditory research by testing the reliability of scanning parameters using high resolution and high signal-to-noise ratios. Findings indicated reproducibility within and across listeners for consonant-vowel speech stimuli and reproducible results within and…

  15. poolMC: Smart pooling of mRNA samples in microarray experiments

    Directory of Open Access Journals (Sweden)

    Schiefelbein John

    2010-06-01

    Full Text Available Abstract Background Typically, pooling of mRNA samples in microarray experiments implies mixing mRNA from several biological-replicate samples before hybridization onto a microarray chip. Here we describe an alternative smart pooling strategy in which different samples, not necessarily biological replicates, are pooled in an information theoretic efficient way. Further, each sample is tested on multiple chips, but always in pools made up of different samples. The end goal is to exploit the compressibility of microarray data to reduce the number of chips used and increase the robustness to noise in measurements. Results A theoretical framework to perform smart pooling of mRNA samples in microarray experiments was established and the software implementation of the pooling and decoding algorithms was developed in MATLAB. A proof-of-concept smart pooled experiment was performed using validated biological samples on commercially available gene chips. Differential-expression analysis of the smart pooled data was performed and compared against the unpooled control experiment. Conclusions The theoretical developments and experimental demonstration in this paper provide a useful starting point to investigate smart pooling of mRNA samples in microarray experiments. Although the smart pooled experiment did not compare favorably with the control, the experiment highlighted important conditions for the successful implementation of smart pooling - linearity of measurements, sparsity in data, and large experiment size.

  16. Regional and voxel-wise comparisons of blood flow measurements between dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and arterial spin labeling (ASL) in brain tumors.

    Science.gov (United States)

    White, Carissa M; Pope, Whitney B; Zaw, Taryar; Qiao, Joe; Naeini, Kourosh M; Lai, Albert; Nghiemphu, Phioanh L; Wang, J J; Cloughesy, Timothy F; Ellingson, Benjamin M

    2014-01-01

    The objective of the current study was to evaluate the regional and voxel-wise correlation between dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) measurement of cerebral blood flow (CBF) in patients with brain tumors. Thirty patients with histologically verified brain tumors were evaluated in the current study. DSC-MRI was performed by first using a preload dose of gadolinium contrast, then collecting a dynamic image acquisition during a bolus of contrast, followed by posthoc contrast agent leakage correction. Pseudocontinuous ASL was collected using 30 pairs of tag and control acquisition using a 3-dimensional gradient-echo spin-echo (GRASE) acquisition. All images were registered to a high-resolution anatomical atlas. Average CBF measurements within regions of contrast-enhancement and T2 hyperintensity were evaluated between the two modalities. Additionally, voxel-wise correlation between CBF measurements obtained with DSC and ASL were assessed. Results demonstrated a positive linear correlation between DSC and ASL measurements of CBF when regional average values were compared; however, a statistically significant voxel-wise correlation was only observed in around 30-40% of patients. These results suggest DSC and ASL may provide regionally similar, but spatially different measurements of CBF.

  17. Test-retest repeatability of myocardial blood flow and infarct size using {sup 11}C-acetate micro-PET imaging in mice

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, Etienne; Renaud, Jennifer M.; McDonald, Matthew; Klein, Ran; DaSilva, Jean N.; Beanlands, Rob S.B.; DeKemp, Robert A. [University of Ottawa Heart Institute, National Cardiac PET Centre, Ottawa, Ontario (Canada)

    2015-09-15

    Global and regional responses of absolute myocardial blood flow index (iMBF) are used as surrogate markers to assess response to therapies in coronary artery disease. In this study, we assessed the test-retest repeatability of iMBF imaging, and the accuracy of infarct sizing in mice using {sup 11}C-acetate PET. {sup 11}C-Acetate cardiac PET images were acquired in healthy controls, endothelial nitric oxide synthase (eNOS) knockout transgenic mice, and mice after myocardial infarction (MI) to estimate global and regional iMBF, and myocardial infarct size compared to {sup 18}F-FDG PET and ex-vivo histology results. Global test-retest iMBF values had good coefficients of repeatability (CR) in healthy mice, eNOS knockout mice and normally perfused regions in MI mice (CR = 1.6, 2.0 and 1.5 mL/min/g, respectively). Infarct size measured on {sup 11}C-acetate iMBF images was also repeatable (CR = 17 %) and showed a good correlation with the infarct sizes found on {sup 18}F-FDG PET and histopathology (r{sup 2} > 0.77; p < 0.05). {sup 11}C-Acetate micro-PET assessment of iMBF and infarct size is repeatable and suitable for serial investigation of coronary artery disease progression and therapy. (orig.)

  18. Color-coded perfused blood volume imaging using multidetector CT: initial results of whole-brain perfusion analysis in acute cerebral ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Kloska, Stephan P.; Fischer, Tobias; Fischbach, Roman; Heindel, Walter [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Nabavi, Darius G.; Dittrich, Ralf; Ringelstein, E.B. [University of Muenster, Department of Neurology, Muenster (Germany); Ditt, Hendrik; Klotz, Ernst [Siemens AG, Medical Solutions, Forchheim (Germany)

    2007-09-15

    Computed tomography (CT) is still the primary imaging modality following acute stroke. To evaluate a prototype of software for the calculation of color-coded whole-brain perfused blood volume (PBV) images from CT angiography (CTA) and nonenhanced CT (NECT) scans, we studied 14 patients with suspected acute ischemia of the anterior cerebral circulation. PBV calculations were performed retrospectively. The detection rate of ischemic changes in the PBV images was compared with NECT. The volume of ischemic changes in PBV was correlated with the infarct volume on follow-up examination taking potential vessel recanalization into account. PBV demonstrated ischemic changes in 12/12 patients with proven infarction and was superior to NECT (8/12) in the detection of early ischemia. Moreover, PBV demonstrated the best correlation coefficient with the follow-up infarct volume (Pearson's R = 0.957; P = 0.003) for patients with proven recanalization of initially occluded cerebral arteries. In summary, PBV appears to be more accurate in the detection of early infarction compared to NECT and mainly visualizes the irreversibly damaged ischemic tissue. (orig.)

  19. The role of red blood cell scintigraphy in the multiple-modality imaging diagnosis of a rare case of diffuse hepatic hemangiomatosis in an adult

    Directory of Open Access Journals (Sweden)

    Ernesto Cason

    2013-03-01

    Full Text Available Introduction: Angiomas are one of the most common primary tumors of the liver. Diffuse hepatic angiomatosis, however, is quite rare and usually observed in pediatric patients. We report a rare case of diffuse hepatic hemangiomatosis in a 33-year-old woman. Case report: The patient presented with abdominal pain and a palpable upper abdominal mass. Abdominal CT and magnetic resonance imaging (MRI findings suggested diffuse hepatic hemangiomatosis, but this finding was not confirmed by subsequent contrast-enhanced abdominal ultrasonography (US. The patient then underwent single photon emission computed tomography (SPECT/CT scintigraphy with Tc-99m-labeling of red blood cells (RBC. This examination revealed increased uptake of labeled erythrocytes in several of the hepatic lesions corresponding to CT and RM findings, thereby confirming the clinical hypothesis of diffuse hepatic hemangiomatosis. Discussion: RBC scintigraphy with SPECT/CT can facilitate the comparison of other crosssectional imaging methods such as CT and MRI. This case highlights the importance of a multiple-modality approach in the imaging diagnosis of this condition.

  20. 77 FR 68133 - Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From Donors of...

    Science.gov (United States)

    2012-11-15

    ...The Food and Drug Administration (FDA) is announcing the availability of a document entitled ``Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples from Donors of Whole Blood and Blood Components, including Source Plasma, to Reduce the Risk of Transmission of Hepatitis B Virus,'' dated October 2012. The guidance document provides recommendations on the use of FDA-......

  1. 76 FR 72950 - Draft Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From...

    Science.gov (United States)

    2011-11-28

    ...The Food and Drug Administration (FDA) is announcing the availability of a draft document entitled ``Guidance for Industry: Use of Nucleic Acid Tests (NAT) on Pooled and Individual Samples from Donors of Whole Blood and Blood Components (including Recovered Plasma, Source Plasma and Source Leukocytes) to Adequately and Appropriately Reduce the Risk of Transmission of Hepatitis B Virus (HBV),......

  2. 10 CFR 36.63 - Pool water purity.

    Science.gov (United States)

    2010-01-01

    ... § 36.63 Pool water purity. (a) Pool water purification system must be run sufficiently to maintain the conductivity of the pool water below 20 microsiemens per centimeter under normal circumstances. If pool water... 10 Energy 1 2010-01-01 2010-01-01 false Pool water purity. 36.63 Section 36.63 Energy...

  3. SAFETY AND MANAGEMENT OF SWIMING POOLS

    Directory of Open Access Journals (Sweden)

    Cemal GÜNDOĞDU

    2008-04-01

    Full Text Available In this study,it was investigated the situation related to the safety and management of swimming pools belongs to municipality This study was planned to determine the present situation related to the safety and management of open,half-olympic and closed swimming pools which are especially used for sports activities,to find out the deficiencies in practise and to overcome these.Our study included totally 80 open,closed,olympic, half-olympic public swimming pools(the pools that belongs to municipality,private administration and university,the colleges connected to the ministry of education, Military schools and police college.In our research,search,natural observation and meeting methods were used.In accordance with this aim the checklist questions,which were prepared for health and safety controls in swimming pools, were tested on the people by face-to-face meeting method. While the statistical evaluation of the available results were being done,frequency and percentage dispersion obtained from checklist was found.It was found that the 52 % of the training and lifeguard choise of the pools in Turkey,64 % of the emergency action equipment,71 % of the signs and signboards for the safety of the pool,75 % of the pool edge and its surroundings are not suitable for the standards and that these threaten the swimmers health importantly.Consequently,we are in the opinion that the pool staff should receive the periodical training about the first aid and using emergency situation equipment.And it is necessary that the Ministry Responsible for sports,Ministry of Interior,Ministry of Health,Ministry of Tourism be cooperate with water sports federations and the related civil society organizationsKey Words: .

  4. Vision-based detection of weld pool width in TIG welding of copper-clad aluminum cable

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In order to realize automatic control of the width of weld pool, a visual sensor system for the width of weld pool detection is developed. By initiative arc light, the image of copper plate weld pool is taken back of the torch through the process of weakening and filtering arc light. In order to decrease the time of processing video signals, analog circuit is applied in the processing where video signals is magnified, trimmed and processed into binary on the datum of dynamic average value, therefore the waveform of video signals of weld pool is obtained. The method that is used for detecting the width of weld pool is established. Results show that the vision sensing method for real-time detecting weld pool width to copper-clad aluminum wire TIG welding is feasible. The response cycle of this system is no more than 50ms, and the testing precision is less than0.1mm.

  5. LCG POOL development status and production experience

    CERN Document Server

    Chytracek, Radovan; Cioffi, Carmine; Düllmann, Dirk; Frank, Markus; Girone, Maria; Govi, Giacomo; Karr, Kristo; Malon, David; Moscicki, Jakub T; Papadopoulos, Ioannis M; Schmücker, H; Tanenbaum, William; Vaniachine, A; Xie Zhen

    2004-01-01

    The POOL project, as a part of the LHC Computing Grid (LCG), is now entering its third year of active development POOL provides the baseline persistency framework for three LHC experiment and is based on a strict component model, insulating experiment software from a variety of storage technology choices. This paper gives a brief overview of the POOL architecture, its main design principles and the experience gained with integration into LHC experiment frameworks. In also presents recent developments in the area of relational database abstraction and object storage into RDBMS systems.

  6. Weld pool visual sensing without external illumination

    DEFF Research Database (Denmark)

    Liu, Jinchao; Fan, Zhun; Olsen, Soren Ingvor

    2011-01-01

    Visual sensing in arc welding has become more and more important, but still remains challenging because of the harsh environment with extremely strong illumination from the arc. This paper presents a low-cost camera-based sensor system, without using external Illumination, but nevertheless able...... to sense and model the weld pool. Central is a carefully selected optical filtering as well as an active contour-based tracking of the weld pool boundary. The system is able to extract the 2D shape of the weld pool in real time. The reported experiments show the feasibility of this approach....

  7. Use of Caval Subtraction 2D Phase-Contrast MR Imaging to Measure Total Liver and Hepatic Arterial Blood Flow: Preclinical Validation and Initial Clinical Translation.

    Science.gov (United States)

    Chouhan, Manil D; Mookerjee, Rajeshwar P; Bainbridge, Alan; Walker-Samuel, Simon; Davies, Nathan; Halligan, Steve; Lythgoe, Mark F; Taylor, Stuart A

    2016-09-01

    Purpose To validate caval subtraction two-dimensional (2D) phase-contrast magnetic resonance (MR) imaging measurements of total liver blood flow (TLBF) and hepatic arterial fraction in an animal model and evaluate consistency and reproducibility in humans. Materials and Methods Approval from the institutional ethical committee for animal care and research ethics was obtained. Fifteen Sprague-Dawley rats underwent 2D phase-contrast MR imaging of the portal vein (PV) and infrahepatic and suprahepatic inferior vena cava (IVC). TLBF and hepatic arterial flow were estimated by subtracting infrahepatic from suprahepatic IVC flow and PV flow from estimated TLBF, respectively. Direct PV transit-time ultrasonography (US) and fluorescent microsphere measurements of hepatic arterial fraction were the standards of reference. Thereafter, consistency of caval subtraction phase-contrast MR imaging-derived TLBF and hepatic arterial flow was assessed in 13 volunteers (mean age, 28.3 years ± 1.4) against directly measured phase-contrast MR imaging PV and proper hepatic arterial inflow; reproducibility was measured after 7 days. Bland-Altman analysis of agreement and coefficient of variation comparisons were undertaken. Results There was good agreement between PV flow measured with phase-contrast MR imaging and that measured with transit-time US (mean difference, -3.5 mL/min/100 g; 95% limits of agreement [LOA], ±61.3 mL/min/100 g). Hepatic arterial fraction obtained with caval subtraction agreed well with those with fluorescent microspheres (mean difference, 4.2%; 95% LOA, ±20.5%). Good consistency was demonstrated between TLBF in humans measured with caval subtraction and direct inflow phase-contrast MR imaging (mean difference, -1.3 mL/min/100 g; 95% LOA, ±23.1 mL/min/100 g). TLBF reproducibility at 7 days was similar between the two methods (95% LOA, ±31.6 mL/min/100 g vs ±29.6 mL/min/100 g). Conclusion Caval subtraction phase-contrast MR imaging is a simple and clinically

  8. Reproducibility of the capsaicin-induced dermal blood flow response as assessed by laser Doppler perfusion imaging

    OpenAIRE

    Van der Schueren, B. J.; Hoon, J.N.; Vanmolkot, F H; Van Hecken, A; Depre, M; Kane, S A; De Lepeleire, I.; Sinclair, S R

    2007-01-01

    What is already known about this subjectCapsaicin rapidly produces local neurogenic inflammation (characterized by oedema and erythema) when locally administered to the human skin by binding to the TRPV1 receptor present on dermal sensory nerve endings.In nonhuman primates, a pharmacodynamic assay has been described and validated using capsaicin-induced dermal vasodilation measured by laser Doppler perfusion imaging to assess calcitonin gene-related peptide antagonist activity.Laser Doppler p...

  9. Fully automated quantification of regional cerebral blood flow with three-dimensional stereotaxic region of interest template. Validation using magnetic resonance imaging. Technical note

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Ryo; Katayama, Shigenori; Takeda, Naoya; Fujita, Katsuzo [Nishi-Kobe Medical Center (Japan); Yonekura, Yoshiharu [Fukui Medical Univ., Matsuoka (Japan); Konishi, Junji [Kyoto Univ. (Japan). Graduate School of Medicine

    2003-03-01

    The previously reported three-dimensional stereotaxic region of interest (ROI) template (3DSRT-t) for the analysis of anatomically standardized technetium-99m-L,L-ethyl cysteinate dimer ({sup 99m}Tc-ECD) single photon emission computed tomography (SPECT) images was modified for use in a fully automated regional cerebral blood flow (rCBF) quantification software, 3DSRT, incorporating an anatomical standardization engine transplanted from statistical parametric mapping 99 and ROIs for quantification based on 3DSRT-t. Three-dimensional T{sub 2}-weighted magnetic resonance images of 10 patients with localized infarcted areas were compared with the ROI contour of 3DSRT, and the positions of the central sulcus in the primary sensorimotor area were also estimated. All positions of the 20 lesions were in strict accordance with the ROI delineation of 3DSRT. The central sulcus was identified on at least one side of 210 paired ROIs and in the middle of 192 (91.4%) of these 210 paired ROIs among the 273 paired ROIs of the primary sensorimotor area. The central sulcus was recognized in the middle of more than 71.4% of the ROIs in which the central sulcus was identifiable in the respective 28 slices of the primary sensorimotor area. Fully automated accurate ROI delineation on anatomically standardized images is possible with 3DSRT, which enables objective quantification of rCBF and vascular reserve in only a few minutes using {sup 99m}Tc-ECD SPECT images obtained by the resting and vascular reserve (RVR) method. (author)

  10. Pelvic magnetic resonance imaging angioanatomy of the arterial blood supply to the penis in suspected prostate cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Cao Tan, E-mail: bstanhatinh@gmail.com [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Karam, Ibrahim Michel [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); Department of Anatomy, Faculty of Medicine Nancy, 9 Avenue de la Foret de haye BP, 54505 Vandoeuvre Lès Nancy Cedex (France); Nguyen-Thi, Phi Linh [Clinical Epidemiology and Evaluation Department, University Hospital of Nancy (France); INSERM, CIC-EC CIE6, 92 Avenue du Maréchal de Lattre de Tassigny, 54000 Nancy (France); Lefèvre, Frédéric [Department of Radiology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); Hubert, Jacques [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France); IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Felblinger, Jacques [IADI Laboratory, INSERM-U947, Brabois Hospital, University Hospital of Nancy, Tour Drouet, rue du Morvan, 54511 Vandoeuvre Lès Nancy Cedex (France); Eschwège, Pascal [Department of Urology, Brabois Hospital, University Hospital of Nancy, Rue du Morvan, 54500 Vandoeuvre Lès Nancy Cedex (France)

    2015-05-15

    Highlights: • Three patterns of penile arterial supply (according to the classification of Stéphane Droupy). • Our classification about accessory pudendal artery. • Origin of accessory pudendal artery. - Abstract: Purpose: To describe the internal pudendal artery (IPA) and accessory pudendal artery (APA) detected by magnetic resonance (MR) angiography to help surgeons to find and preserve them during radical prostatectomy (RP). Materials and methods: Constrast-enhanced MR 3.0 T angiography of the pelvis were performed in 111 male patients suspected diagnosis of prostate cancer (PCa), and describe the penile arterial blood supply. Results: There are three patterns of the arterial blood supply to the penis (IPA and/or APA) accounting for 51.4%, 46.8% and 1.8% of cases, respectively. About the accessory pudendal artery (APA): 54/111 (48.6%) patients had APA with five different branching patterns, they were type I (APA bilateral symmetry): 17 (31.5%); type II (APA bilateral asymmetry): 1 (1.9%); type III (APA unilateral lateral): 13 (24%); type IV (APA unilateral apical): 21 (38.9%); type V (APA unilateral mix): 2 (3.7%). APA origin were from inferior epigastric artery (IEA): 7 (9.5%); from inferior vesical artery (IVA): 32 (43.2%); from obturator artery (OA): 35 (47.3%). Conclusion: A precise angioanatomic evalutation of arteries destined to the penis by MR angiography pre-operation for male pelvic organs will help surgeons to preserve them and contributes to reduce the erectile dysfunction after these procedures.

  11. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Elżbieta Pociask

    2016-01-01

    Full Text Available Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement, segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects.

  12. Robotic cleaning of a spent fuel pool

    Energy Technology Data Exchange (ETDEWEB)

    Roman, H.T.; Marian, F.A. (PSE and G Research Corp., Newark, NJ (US)); Silverman, E.B.; Barkley, V.P. (ARD Corp., Columbia, MD (US))

    1987-05-01

    Spent fuel pools at nuclear power plants are not cleaned routinely, other than by purifying the water that they contain. Yet, debris can collect on the bottom of a pool and should be removed prior to fuel transfer. At Public Service Electric and Gas Company's Hope Creek Nuclear Power Plant, a submersible mobile robot - ARD Corporation's SCAVENGER - was used to clean the bottom of the spent fuel pool prior to initial fuel loading. The robotic device was operated remotely (as opposed to autonomously) with a simple forward/reverse control, and it cleaned 70-80% of the pool bottom. This paper reports that a simple cost-benefit analysis shows that the robotic device would be less expensive, on a per mission basis, than other cleaning alternatives, especially if it were used for other similar cleaning operations throughout the plant.

  13. Analysis of Bitcoin Pooled Mining Reward Systems

    CERN Document Server

    Rosenfeld, Meni

    2011-01-01

    In this paper we describe the various scoring systems used to calculate rewards of participants in Bitcoin pooled mining, explain the problems each were designed to solve and analyze their respective advantages and disadvantages.

  14. Tehas teisel pool Kuud / Gert Kiiler

    Index Scriptorium Estoniae

    Kiiler, Gert

    2009-01-01

    Tartu Ülikooli Viljandi kultuuriakadeemia teatrikunsti tudengite seitsmendast lennust kõneleva saate "Tehas teisel pool Kuud" tegemisest. Saade Eesti Televisioonis 3. juunil. Produtsent Kadi Katarina Priske, režissöör Elo Selirand

  15. Effect of hinge gap width of a St. Jude medical bileaflet mechanical heart valve on blood damage potential--an in vitro micro particle image velocimetry study.

    Science.gov (United States)

    Jun, Brian H; Saikrishnan, Neelakantan; Arjunon, Sivakkumar; Yun, B Min; Yoganathan, Ajit P

    2014-09-01

    The hinge regions of the bileaflet mechanical heart valve (BMHV) can cause blood element damage due to nonphysiological shear stress levels and regions of flow stasis. Recently, a micro particle image velocimetry (μPIV) system was developed to study whole flow fields within BMHV hinge regions with enhanced spatial resolution under steady leakage flow conditions. However, global velocity maps under pulsatile conditions are still necessary to fully understand the blood damage potential of these valves. The current study hypothesized that the hinge gap width will affect flow fields in the hinge region. Accordingly, the blood damage potential of three St. Jude Medical (SJM) BMHVs with different hinge gap widths was investigated under pulsatile flow conditions, using a μPIV system. The results demonstrated that the hinge gap width had a significant influence during the leakage flow phase in terms of washout and shear stress characteristics. During the leakage flow, the largest hinge gap generated the highest Reynolds shear stress (RSS) magnitudes (~1000 N/m²) among the three valves at the ventricular side of the hinge. At this location, all three valves indicated viscous shear stresses (VSS) greater than 30 N/m². The smallest hinge gap exhibited the lowest level of shear stress values, but had the poorest washout flow characteristics among the three valves, demonstrating propensity for flow stasis and associated activated platelet accumulation potential. The results from this study indicate that the hinge is a critical component of the BMHV design, which needs to be optimized to find the appropriate balance between reduction in fluid shear stresses and enhanced washout during leakage flow, to ensure minimal thrombotic complications.

  16. Blood smear

    Science.gov (United States)

    ... some red blood cells shaped like spheres ( hereditary spherocytosis ) Increased breakdown of RBCs Presence of RBCs with ... normal Red blood cells, elliptocytosis Red blood cells, spherocytosis Acute lymphocytic leukemia - photomicrograph Red blood cells, multiple ...

  17. Blood culture

    Science.gov (United States)

    Culture - blood ... A blood sample is needed . The site where blood will be drawn is first cleaned with an antiseptic such ... organism from the skin getting into (contaminating) the blood sample and causing a false-positive result (see ...

  18. Blood Thinners

    Science.gov (United States)

    If you have some kinds of heart or blood vessel disease, or if you have poor blood flow to your brain, your doctor may recommend that you take a blood thinner. Blood thinners reduce the risk of heart ...

  19. Blood transfusions

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000431.htm Blood transfusions To use the sharing features on this ... several sources of blood which are described below. Blood From the Public (Volunteer Blood Donation) The most ...

  20. Sequential technetium-99m sulfur colloid/indium-111 white blood cell imaging in macroglobulinemia of Waldenstrom

    Energy Technology Data Exchange (ETDEWEB)

    Fink-Bennett, D.; Balon, H.R.; Irwin, R. (William Beaumont Hospital, Royal Oak, MI (USA))

    1990-06-01

    Technetium-99m sulfur colloid (SC) and indium-111 labeled leukocyte (In-111 WBC) scintigraphy was performed on a 77-year-old female patient to rule out a left periprosthetic infection. Anterior Tc-99m SC and In-111 WBC images of the pelvis and femurs revealed no abnormal deposition of radiotracer about the Austin-Moore prosthesis. Absent radiotracer uptake, however, was demonstrated within the left hemipelvis. A left iliac bone marrow aspirate and biopsy revealed a lymphoplasmacytic infiltrate consistent with Waldenstrom's macroglobulinemia.

  1. Live cell imaging techniques to study T cell trafficking across the blood-brain barrier in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Coisne Caroline

    2013-01-01

    Full Text Available Abstract Background The central nervous system (CNS is an immunologically privileged site to which access for circulating immune cells is tightly controlled by the endothelial blood–brain barrier (BBB located in CNS microvessels. Under physiological conditions immune cell migration across the BBB is low. However, in neuroinflammatory diseases such as multiple sclerosis, many immune cells can cross the BBB and cause neurological symptoms. Extravasation of circulating immune cells is a multi-step process that is regulated by the sequential interaction of different adhesion and signaling molecules on the immune cells and on the endothelium. The specialized barrier characteristics of the BBB, therefore, imply the existence of unique mechanisms for immune cell migration across the BBB. Methods and design An in vitro mouse BBB model maintaining physiological barrier characteristics in a flow chamber and combined with high magnification live cell imaging, has been established. This model enables the molecular mechanisms involved in the multi-step extravasation of T cells across the in vitro BBB, to be defined with high-throughput analyses. Subsequently these mechanisms have been verified in vivo using a limited number of experimental animals and a spinal cord window surgical technique. The window enables live observation of the dynamic interaction between T cells and spinal cord microvessels under physiological and pathological conditions using real time epifluorescence intravital imaging. These in vitro and in vivo live cell imaging methods have shown that the BBB endothelium possesses unique and specialized mechanisms involved in the multi-step T cell migration across this endothelial barrier under physiological flow. The initial T cell interaction with the endothelium is either mediated by T cell capture or by T cell rolling. Arrest follows, and then T cells polarize and especially CD4+ T cells crawl over long distances against the direction of

  2. Profit pools: a fresh look at strategy.

    Science.gov (United States)

    Gadiesh, O; Gilbert, J L

    1998-01-01

    In charting strategy, many managers focus on revenue growth, assuming that profits will follow. But that approach is dangerous: today's deep revenue pool may become tomorrow's dry hole. To create strategies that result in profitable growth, managers need to look beyond revenues to see the shape of their industry's profit pool. The authors define an industry's profit pool as the total profits earned at all points along the industry's value chain. Although the concept is simple, the structure of a profit pool is usually quite complex. The pool will be deeper in some segments of the value chain than in others, and depths will vary within an individual segment as well. Segment profitability may, for example, vary widely by customer group, product category, geographic market, and distribution channel. Moreover, the pattern of profit concentration in an industry will often be very different from the pattern of revenue concentration. The authors describe how successful companies have gained competitive advantage by developing sophisticated profit-pool strategies. They explain how U-Haul identified new sources of profit in the consumer-truck-rental industry; how Merck reached beyond its traditional value-chain role to protect its profits in the pharmaceuticals industry; how Dell rebounded from a misguided channel decision by refocusing on its traditional source of profit; and how Anheuser-Busch made a series of astute product, pricing, and operating decisions to dominate the beer industry's profit pool. The companies with the best understanding of their industry's profit pool, the authors argue, will be in the best position to thrive over the long term.

  3. Pooling strategies for St Petersburg gamblers

    OpenAIRE

    Csörgö, Sandor; Simons, Gordon

    2006-01-01

    Peter offers to play exactly one St Petersburg game with each of [math] players, Paul [math] , [math] , Paul [math] , whose conceivable pooling strategies are described by all possible probability distributions [math] . Comparing infinite expectations, we characterize among all [math] those admissible strategies for which the pooled winnings, each distributed as [math] , yield a finite added value for each and every one of Paul [math] , [math] , Paul [math] in comparison with their individual...

  4. How to map your industry's profit pool.

    Science.gov (United States)

    Gadiesh, O; Gilbert, J L

    1998-01-01

    Many managers chart strategy without a full understanding of the sources and distribution of profits in their industry. Sometimes they focus their sights on revenues instead of profits, mistakenly assuming that revenue growth will eventually translate into profit growth. In other cases, they simply lack the data or the analytical tools required to isolate and measure variations in profitability. In this Manager's Tool Kit, the authors present a way to think clearly about where the money's being made in any industry. They describe a framework for analyzing how profits are distributed among the activities that form an industry's value chain. Such an analysis can provide a company's managers with a rich understanding of their industry's profit structure--what the authors call its profit pool--enabling them to identify which activities are generating disproportionately large or small shares of profits. Even more important, a profit-pool map opens a window onto the underlying structure of the industry, helping managers see the various forces that are determining the distribution of profits. As such, a profit-pool map provides a solid basis for strategic thinking. Mapping a profit pool involves four steps: defining the boundaries of the pool, estimating the pool's overall size, estimating the size of each value-chain activity in the pool, and checking and reconciling the calculations. The authors briefly describe each step and then apply the process by providing a detailed example of a hypothetical retail bank. They conclude by looking at ways of organizing the data in chart form as a first step toward plotting a profit-pool strategy.

  5. Gene transcript analysis blood values correlate with {sup 68}Ga-DOTA-somatostatin analog (SSA) PET/CT imaging in neuroendocrine tumors and can define disease status

    Energy Technology Data Exchange (ETDEWEB)

    Bodei, L. [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Kidd, M.; Modlin, I.M.; Drozdov, I. [Wren Laboratories, Branford, CT (United States); Prasad, V. [Charite University Hospital, Department of Nuclear Medicine, Berlin (Germany); Severi, S.; Paganelli, G. [Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST) IRCCS, Nuclear Medicine and Radiometabolic Units, Meldola (Italy); Ambrosini, V. [S. Orsola-Malpighi University Hospital, Nuclear Medicine, Bologna (Italy); Kwekkeboom, D.J.; Krenning, E.P. [Erasmus Medical Center Rotterdam, Nuclear Medicine Department, Rotterdam (Netherlands); Baum, R.P. [Zentralklinik Bad Berka, THERANOSTICS Center for Molecular Radiotherapy and Imaging, Bad Berka (Germany)

    2015-08-15

    Precise determination of neuroendocrine tumor (NET) disease status and response to therapy remains a rate-limiting concern for disease management. This reflects limitations in biomarker specificity and resolution capacity of imaging. In order to evaluate biomarker precision and identify if combinatorial blood molecular markers and imaging could provide added diagnostic value, we assessed the concordance between {sup 68}Ga-somatostatin analog (SSA) positron emission tomography (PET), circulating NET gene transcripts (NETest), chromogranin A (CgA), and Ki-67 in NETs. We utilized two independent patient groups with positive {sup 68}Ga-SSA PET: data set 1 ({sup 68}Ga-SSA PETs undertaken for peptide receptor radionuclide therapy (PRRT), as primary or salvage treatment, n = 27) and data set 2 ({sup 68}Ga-SSA PETs performed in patients referred for initial disease staging or restaging after various therapies, n = 22). We examined the maximum standardized uptake value (SUV{sub max}), circulating gene transcripts, CgA levels, and baseline Ki-67. Regression analyses, generalized linear modeling, and receiver-operating characteristic (ROC) analyses were undertaken to determine the strength of the relationships. SUV{sub max} measured in two centers were mathematically evaluated (regression modeling) and determined to be comparable. Of 49 patients, 47 (96 %) exhibited a positive NETest. Twenty-six (54 %) had elevated CgA (χ{sup 2} = 20.1, p < 2.5 x 10{sup -6}). The majority (78 %) had Ki-67 < 20 %. Gene transcript scores were predictive of imaging with >95 % concordance and significantly correlated with SUV{sub max} (R {sup 2} = 0.31, root-mean-square error = 9.4). The genes MORF4L2 and somatostatin receptors SSTR1, 3, and 5 exhibited the highest correlation with SUV{sub max}. Progressive disease was identified by elevated levels of a quotient of MORF4L2 expression and SUV{sub max} [ROC-derived AUC (R {sup 2} = 0.7, p < 0.05)]. No statistical relationship was identified

  6. Magnitude of shift of tumor position as a function of moderated deep inspiration breath-hold: An analysis of pooled data of lung patients with active breath control in image-guided radiotherapy

    Directory of Open Access Journals (Sweden)

    Muralidhar K

    2008-01-01

    Full Text Available The purpose of this study was to evaluate the reproducibility and magnitude of shift of tumor position by using active breathing control and iView-GT for patients with lung cancer with moderate deep-inspiration breath-hold (mDIBH technique. Eight patients with 10 lung tumors were studied. CT scans were performed in the breath-holding phase. Moderate deep-inspiration breath-hold under spirometer-based monitoring system was used. Few important bony anatomic details were delineated by the radiation oncologist. To evaluate the interbreath-hold reproducibility of the tumor position, we compared the digital reconstruction radiographs (DRRs from planning system with the DRRs from the iView-GT in the machine room. We measured the shift in x, y, and z directions. The reproducibility was defined as the difference between the bony landmarks from the DRR of the planning system and those from the DRR of the iView-GT. The maximum shift of the tumor position was 3.2 mm, 3.0 mm, and 2.9 mm in the longitudinal, lateral, and vertical directions. In conclusion, the moderated deep-inspiration breath-hold method using a spirometer is feasible, with relatively good reproducibility of the tumor position for image-guided radiotherapy in lung cancers.

  7. Recent advances in probabilistic species pool delineations

    Directory of Open Access Journals (Sweden)

    Dirk Nikolaus Karger

    2016-07-01

    Full Text Available A species pool is the set of species that could potentially colonize and establish within a community. It has been a commonly used concept in biogeography since the early days of MacArthur and Wilson’s work on Island Biogeography. Despite their simple and appealing definition, an operational application of species pools is bundled with a multitude of problems, which have often resulted in arbitrary decisions and workarounds when defining species pools. Two recently published papers address the operational problems of species pool delineations, and show ways of delineating them in a probabilistic fashion. In both papers, species pools were delineated using a process-based, mechanistical approach, which opens the door for a multitude of new applications in biogeography. Such applications include detecting the hidden signature of biotic interactions, disentangling the geographical structure of community assembly processes, and incorporating a temporal extent into species pools. Although similar in their conclusions, both ‘probabilistic approaches’ differ in their implementation and definitions. Here I give a brief overview of the differences and similarities of both approaches, and identify the challenges and advantages in their application.