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Sample records for intravascular ultrasound measurements

  1. Intravascular ultrasound

    Science.gov (United States)

    IVUS; Ultrasound - coronary artery; Endovascular ultrasound; Intravascular echocardiography ... A tiny ultrasound wand is attached to the top of a thin tube. This tube is called a catheter. The catheter ...

  2. Harmonic Intravascular Ultrasound

    NARCIS (Netherlands)

    M.E. Frijlink (Martijn)

    2006-01-01

    textabstractMedical ultrasound is a popular imaging modality in cardiology. Harmonic Imaging is a technique that has been shown to increase the image quality of diagnostic ultrasound at frequencies below 10 MHz. However, Intravascular Ultrasound, which is a technique to acoustically investigate arte

  3. Harmonic Intravascular Ultrasound

    NARCIS (Netherlands)

    M.E. Frijlink (Martijn)

    2006-01-01

    textabstractMedical ultrasound is a popular imaging modality in cardiology. Harmonic Imaging is a technique that has been shown to increase the image quality of diagnostic ultrasound at frequencies below 10 MHz. However, Intravascular Ultrasound, which is a technique to acoustically investigate arte

  4. Accuracy of electrocardiographic-gated versus nongated volumetric intravascular ultrasound measurements of coronary arterial narrowing

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per

    2007-01-01

    Intravascular ultrasound (IVUS) allows precise measurements of plaque plus media (P+M) volume and neointimal hyperplasia after coronary artery stenting. Conventional IVUS volumetric analysis is performed mostly without electrocardiographically gated acquisition, and the IVUS images are selected...... in changes between 2 electrocardiographically gated and 2 nongated pullbacks (lumen: 0.37 +/- 1.76 vs -0.23 +/- 2.32 mm(3), p = NS; EEM: 0.25 +/- 3.22 vs -0.94 +/- 4.27 mm(3), p = NS; P+M: -0.18 +/- 3.42 vs -0.74 +/- 3.88 mm(3), p = NS). In conclusion, in moderate atherosclerotic or stented coronary arteries...

  5. Mapping intravascular ultrasound controversies in interventional cardiology practice.

    Directory of Open Access Journals (Sweden)

    David Maresca

    Full Text Available Intravascular ultrasound is a catheter-based imaging modality that was developed to investigate the condition of coronary arteries and assess the vulnerability of coronary atherosclerotic plaques in particular. Since its introduction in the clinic 20 years ago, use of intravascular ultrasound innovation has been relatively limited. Intravascular ultrasound remains a niche technology; its clinical practice did not vastly expand, except in Japan, where intravascular ultrasound is an appraised tool for guiding percutaneous coronary interventions. In this qualitative research study, we follow scholarship on the sociology of innovation in exploring both the current adoption practices and perspectives on the future of intravascular ultrasound. We conducted a survey of biomedical experts with experience in the technology, the practice, and the commercialization of intravascular ultrasound. The collected information enabled us to map intravascular ultrasound controversies as well as to outline the dynamics of the international network of experts that generates intravascular ultrasound innovations and uses intravascular ultrasound technologies. While the technology is praised for its capacity to measure coronary atherosclerotic plaque morphology and is steadily used in clinical research, the lack of demonstrated benefits of intravascular ultrasound guided coronary interventions emerges as the strongest factor that prevents its expansion. Furthermore, most of the controversies identified were external to intravascular ultrasound technology itself, meaning that decision making at the industrial, financial and regulatory levels are likely to determine the future of intravascular ultrasound. In light of opinions from the responding experts', a wider adoption of intravascular ultrasound as a stand-alone imaging modality seems rather uncertain, but the appeal for this technology may be renewed by improving image quality and through combination with

  6. Nonlinear intravascular ultrasound contrast imaging

    NARCIS (Netherlands)

    Goertz, David E.; Frijlink, Martijn E.; de Jong, N.; van der Steen, Antonius F.W.

    2006-01-01

    Nonlinear contrast agent imaging with intravascular ultrasound (IVUS) is investigated using a prototype IVUS system and an experimental small bubble contrast agent. The IVUS system employed a mechanically scanned single element transducer and was operated at a 20 MHz transmit frequency (F20) for

  7. Multicenter assessment of the reproducibility of volumetric radiofrequency-based intravascular ultrasound measurements in coronary lesions that were consecutively stented

    DEFF Research Database (Denmark)

    Huisman, Jennifer; Egede, Rasmus; Rdzanek, Adam

    2012-01-01

    To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibili...... on average the highest measurement reproducibility. A central analysis for VH-IVUS multicenter studies of lesions prior to PCI should be pursued. Moreover, it may be problematical to pool VH-IVUS data of individual trials analyzed by independent centers.......To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility...... of volumetric VH-IVUS measurements, experienced analysts of 4 European IVUS centers performed independent analyses (in total 8,052 cross-sectional analyses) to obtain volumetric data of 40 coronary segments (length 20.0 ± 0.3 mm) from target lesions prior to percutaneous intervention that were performed...

  8. Intravascular ultrasound tissue harmonic imaging in vivo.

    Science.gov (United States)

    Frijlink, Martijn E; Goertz, David E; van Damme, Luc C A; Krams, Rob; van der Steen, Antonius F W

    2006-10-01

    Tissue harmonic imaging (THI) has been shown to increase image quality of medical ultrasound in the frequency range from 2 to 10 MHz and might, therefore, also be used to improve image quality in intravascular ultrasound (IVUS). In this study we constructed a prototype IVUS system that could operate in both fundamental frequency and second harmonic imaging modes. This system uses a conventional, continuously rotating, single-element IVUS catheter and was operated in fundamental 20 MHz, fundamental 40 MHz, and harmonic 40 MHz modes (transmit 20 MHz, receive 40 MHz). Hydrophone beam characterization measurements demonstrated the build-up of a second harmonic signal as a function of increasing pressure. Imaging experiments were conducted in both a tissue-mimicking phantom and in an atherosclerotic animal model in vivo. Acquisitions of fundamental 20 and 40 MHz and second harmonic acquisitions resulted in cross sections of the phantom and a rabbit aorta. The harmonic results of the imaging experiments showed the feasibility of intravascular THI with a conventional IVUS catheter both in a phantom and in vivo. The harmonic acquisitions also showed the potential of THI to reduce image artifacts compared to fundamental imaging.

  9. Image and Signal Processing in Intravascular Ultrasound

    NARCIS (Netherlands)

    W. Li (Wenguang)

    1997-01-01

    textabstractIntravascular ultrasound (rvUS) is a new imaging mOdality providing real-time, crosssectional, high-resolution images of the arterial lumen and vessel wall. In contrast to conventional x-ray angiography that only displays silhouette views of the vessel lumen, IVUS imaging permits visuali

  10. Transducer for harmonic intravascular ultrasound imaging

    NARCIS (Netherlands)

    Vos, Hendrik J.; Frijlink, Martijn E.; Droog, E.J.; Goertz, David E.; Blacquiere, Gerrit; Gisolf, Anton; de Jong, N.; van der Steen, Antonius F.W.

    2005-01-01

    A recent study has shown the feasibility of tissue harmonic imaging (THI) using an intravascular ultrasound (IVUS) transducer. This correspondence describes the design, fabrication, and characterization of a THI-optimized piezoelectric transducer with oval aperture of 0.75 mm by 1 mm. The transducer

  11. Intravascular ultrasound in the endovascular management of atherosclerotic peripheral occlusive disease.

    Science.gov (United States)

    Colli, Rosa; Di Stasi, Carmine; Modugno, Pietro; Orlando, Giuseppe; Cavallaro, Antonio

    2004-01-01

    This study is a retrospective analysis of the impact of intravascular ultrasound in addiction to conventional angiography in 36 patients with 55 stenotic peripheral arterial lesions treated with angioplasty and/or stenting. Before treatment, intravascular ultrasound imaging showed that the vessel diameter was underestimated with angiography in 6 cases. The correlation index between angiography and intravascular ultrasound measurements, however, was significant in 27 arterial lesions. After endovascular treatment, angiography showed 3 vessel dissections and no incomplete stent deployment, whereas intravascular ultrasound showed 15 dissections and 5 instances of stent underdeployment. If we consider the intravascular ultrasound data as the gold standard, the specificity of angiography is 100%, while its sensitivity is 56% for vessel dissection and 75% for stent deployment. In the follow up of the 16 patients treated for iliac lesions with intravascular ultrasound control, re-stenosis occurred in 5% (primary patency 94.7%); in a control group of 15 patients treated in the same period without intravascular ultrasound control, re-stenosis occurred in 15.8% (primary patency 83.4%, difference not statistically significant). In conclusion, in the peripheral arteries intravascular ultrasound is more accurate than arteriography in evaluating dissection and stent deployment, but the routine use of intravascular ultrasound in every case of iliac PTA or stenting would not appear justified.

  12. Micromachined capacitive transducer arrays for intravascular ultrasound

    Science.gov (United States)

    Degertekin, F. Levent; Guldiken, R. Oytun; Karaman, Mustafa

    2005-01-01

    Intravascular ultrasound (IVUS) imaging has become an essential imaging modality for the effective diagnosis and treatment of cardiovascular diseases during the past decade enabled by innovative applications of piezoelectric transducer technology. The limitations in the manufacture and performance of the same piezoelectric transducers have also impeded the improvement of IVUS for emerging clinically important applications such as forward viewing arrays for guiding interventions and high resolution imaging of arterial structure such as vulnerable plaque and fibrous cap, and also implementation of techniques such as harmonic imaging of the tissue and of the contrast agents. Capacitive micromachined ultrasonic transducer (CMUT) technology shows great potential for transforming IVUS not only to satisfy these clinical needs but also to open up possibilities for low-cost imaging devices integrated to therapeutic tools. We have developed manufacturing processes with a maximum process temperature of 250°C to build CMUTs on the same silicon chip with integrated electronics. Using these processes we fabricated CMUT arrays suitable for forward viewing IVUS in the 10-20MHz range. We characterized these array elements in terms of pulse-echo response, radiation pattern measurements and demonstrated its volumetric imaging capabilities on various imaging targets.

  13. Mapping Intravascular Ultrasound Controversies in Interventional Cardiology Practice

    NARCIS (Netherlands)

    Maresca, D.; Adams, S.; Maresca, B.; Van der Steen, A.F.W.

    2014-01-01

    Intravascular ultrasound is a catheter-based imaging modality that was developed to investigate the condition of coronary arteries and assess the vulnerability of coronary atherosclerotic plaques in particular. Since its introduction in the clinic 20 years ago, use of intravascular ultrasound innova

  14. Fast integrated intravascular photoacoustic/ultrasound catheter

    Science.gov (United States)

    Choi, Changhoon; Cho, Seunghee; Kim, Taehoon; Park, Sungjo; Park, Hyoeun; Kim, Jinmoo; Lee, Seunghoon; Kang, Yeonsu; Jang, Kiyuk; Kim, Chulhong

    2016-03-01

    In cardiology, a vulnerable plaque is considered to be a key subject because it is strongly related to atherosclerosis and acute myocardial infarction. Because conventional intravascular imaging devices exhibit several limitations with regard to vulnerable plaque detection, the need for an effective lipid imaging modality has been continuously suggested. Photoacoustic (PA) imaging is a medical imaging technique with a high level of ultrasound (US) resolution and strong optical contrast. In this study, we successfully developed an integrated intravascular photoacoustic/ultrasound (IV-PAUS) imaging system with a catheter diameter of 1.2 mm for lipid-rich atherosclerosis imaging. An Nd:YAG pulsed laser with an excitation wavelength of 1064 nm was utilized. IV-PAUS offers 5-mm depth penetration and axial and lateral PA imaging resolutions of 94 μm and 203 μm, respectively, as determined by imaging a 6-μm carbon fiber. We initially obtained 3-dimensional (3D) co-registered PA/US images of metal stents. Subsequently, we successfully obtained 3D coregistered PA/US ex vivo images using an iliac artery from a rabbit atherosclerosis model. Accordingly, lipid-rich plaques were sufficiently differentiated from normal tissue in the ex vivo experiment. We validated these findings histologically to confirm the lipid content.

  15. Intravascular Ultrasound Image Segmentation Using Morphological Snakes

    Directory of Open Access Journals (Sweden)

    Hamdi Mohamed Ali

    2012-06-01

    Full Text Available From the first use of the technics of intravascular ultrasound (IVUS as an imaging technique for the coronary artery system at the 70th century until now , the segmentation of the arterial wall boundaries still an important problem . Much research has been done to give better segmentation result for better diagnostics , evaluation and therapy planning. In this paper we present a new segmentation technics based on Morphological Snakes which developed by Luis Álvarez used for the first time for IVUS segmentation. It is a simple , fast and stable approach of snakes evolution algorithm. Results are presented and discussed in order to demonstrate the effectiveness of this approach in IVUS segmentation.

  16. Experience With Intravascular Ultrasound Imaging Of Human Atherosclerotic Arteries

    Science.gov (United States)

    Mallery, John A.; Gessert, James M.; Maciel, Mario; Tobis, John M.; Griffith, James M.; Berns, Michael W.; Henry, Walter L.

    1989-08-01

    Normal human arteries have a well-defined structure on intravascular images. The intima appears very thin and is most likely represented by a bright reflection arising from the internal elastic lamina. The smooth muscle tunica media is echo-lucent on the ultrasound image and appears as a dark band separating the intima from the adventitia. The adventitia is a brightly reflective layer of variable thickness. The thickness of the intima, and therefore of the atherosclerotic plaque can be accurately measured from the ultrasound images and correlates well with histology. Calcification within the wall of arteries is seen as bright echo reflection with shadowing of the peripheral wall. Fibrotic regions are highly reflective but do not shadow. Necrotic liquid regions within advanced atherosclerotic plaques are seen on ultrasound images as large lucent zones surrounded by echogenic tissue. Imaging can be performed before and after interventional procedures, such as laser angioplasty, balloon angioplasty and atherectomy. Intravascular ultrasound appears to provide an imaging modality for identifying the histologic characteristics of diseased arteries and for quantifying plaque thickness. It might be possible to perform such quantification to evaluate the results of interventional procedures.

  17. Subharmonic Contrast Intravascular Ultrasound for Vasa Vasorum Imaging

    NARCIS (Netherlands)

    Goertz, David E.; Frijlink, Martijn E.; Tempel, Dennie; Bhagwandas, Vijay; Gisolf, Andries; Krams, Robert; Jong, de Nico; Steen, van der Antonius F.W.

    2007-01-01

    The feasibility of subharmonic contrast intravascular ultrasound (IVUS) imaging was investigated using a prototype nonlinear IVUS system and the commercial contrast agent Definity™. The system employed a mechanically scanned commercial catheter with a custom transducer element fabricated to have sen

  18. Accuracy of Intravascular Ultrasound Evaluation for the Assessment of Native Valve Measures in Patients Undergoing TAVI: Preliminary Results.

    Science.gov (United States)

    de Cillis, Emanuela; Dachille, Annamaria; Giardinelli, Francesco; Acquaviva, Tommaso; Bortone, Alessandro Santo

    2016-10-26

    Transcatheter aortic valve implantation (TAVI) technique represents a real revolution in the field of interventional cardiology and medicine, in particular for the treatment of severe aortic valve stenosis in elderly patients or in patients when the periprocedural risk for the traditional surgical option is considered too high, as an alternative to the traditional aortic valve replacement. Although experience on the valves of the last generation is still limited in terms of time, the data currently available are definitely moving in the direction of a minimum hospital mortality (1%) as well as a drastic reduction in the incidence of complications when compared to the devices of the previous generation. Finally, the evolution of specified materials of the newest generation have greatly enhanced safety and efficacy of TAVI procedures in the last years. In order to ensure the selection of the most appropriate valve and the success of the procedure, the role of cardiac imaging (computed tomography scan evaluation and angiography) is crucial. These examinations require the use of contrast medium in patients suffering from renal dysfunction at the baseline. The need for fluoroscopy and angiography using contrast agents to aid positioning of the valve may lead to contrast-induced nephropathy (CIN) as one form or one etiology of acute kidney injury (AKI), which is associated with increased morbidity and mortality. The aim of our study is to investigate the accuracy of intravascular ultrasound (IVUS-a technique which does not need contrast) for the assessment of native valve measures in patients undergoing TAVI by comparing values obtained with IVUS to those ones previously obtained in the same patients with computed tomography (CT) scans. We enrolled 25 consecutive patients (10 males, average age 81.3±5,1 years) who underwent TAVI with femoral access in our Cardiac Surgery Cath-Lab (University of Bari) from January to October 2015 (Logistic EuroSCORE 21.6±15.4%; STS

  19. Intravascular ultrasound for angiographically indeterminant left main coronary artery disease.

    Science.gov (United States)

    Parashara, D K; Jacobs, L E; Ledley, G S; Yazdanfar, S; Oline, J; Kotler, M N

    1994-01-01

    The precise diagnosis of the presence of significant left main coronary artery disease has profound prognostic and therapeutic implications. Coronary cineangiography has shown to be imprecise and inaccurate to determine the percent stenosis of the left main coronary artery. We report a case with significant left main coronary artery disease in whom coronary cineangiography was in discordance with the clinical data and intravascular ultrasonography. Based on the intravascular ultrasound findings, the patient underwent coronary artery bypass graft surgery. Therefore, the intravascular ultrasonography may be the procedure of choice for assessing indeterminant left main coronary artery lesions by coronary angiography.

  20. Assessment of culprit lesions by intravascular ultrasound in patients with acute myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    LIU Jian; LIU Chuan-fen; LU Ming-yu; MA Yu-liang; WANG Long; CHEN Hong; WANG Wei-min

    2009-01-01

    Background Intravascular ultrasound has become the standard invasive method for diagnosing coronary artery disease. The aim of the present study was to evaluate the ability of intravascular ultrasound for assessment of culprit lesion morphology during primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI).Methods We performed 18 intravascular ultrasound assessments preintervention during the primary PCI for AMI. intravascular ultrasound analysis included qualitative and quantitative measurements of reference and lesion extemal elastic membrane (EEM), lumen, and plaque plus media (P&M) area. Positive remodeling was defined as lesion/mean reference EEM >1.0. Culprit lesions were identified by a combination of electrocardiogram (ECG) and coronary angiography.Results There was an average of 1.44 infarct-related artery (IRA) plaques per patient. The incidences of thrombus and plaque ruptures were 28% (5) and 33% (6), respectively. Hypoechoic plaque was observed in 72% (13) of AMI patients. Calcified lesions could be found in 33% (6) of culprit lesions. Sixty percent of the culprit lesion sites presented with positive remodeling.Conclusions Intravascular ultrasound is a safe and feasible imaging modality in patients with AMI and can help identify plaque rupture, intracoronary thrombus or calcification. The culprit lesion site in AMI cases often presents with positive remodeling.

  1. Application of tissue characterization in intravascular ultrasound imaging

    Science.gov (United States)

    Mullen, William L.; Fitzgerald, Peter J.; Yock, Paul G.

    1994-05-01

    Current intravascular ultrasound imaging technology is able to determine the extent and distribution of pathologic processes within the vessel wall, but is not highly sensitive in discriminating between certain types of tissue. `Tissue characterization' refers to a set of computer-based techniques that utilize features of the ultrasound signal beyond basic amplitude to help define the composition of the tissue of interest. This technique involves quantitative analysis of the ultrasound signals reflected from tissue before these signals pass through the processing steps in the ultrasound instrument.

  2. Mechanical scanning in intravascular ultrasound imaging: Artifacts and driving mechanisms

    NARCIS (Netherlands)

    H. ten Hoff (H.); E.J. Gussenhoven (Elma); C.M. Korbijn (Carin); F. Mastik (Frits); C.T. Lancée (Charles); N. Bom (Klaas)

    1995-01-01

    textabstractObjective: Currently, intravascular ultrasound (US) imaging catheters are developed and produced to provide a complementary diagnostic method in the treatment of blood vessel obstructive disease. Typical catheter dimensions are a diameter of 1–2.5 mm and a length of 1–1.5 m. A real-time

  3. Subharmonic contrast intravascular ultrasound for vasa vasorum imaging.

    Science.gov (United States)

    Goertz, David E; Frijlink, Martijn E; Tempel, Dennie; Bhagwandas, Vijay; Gisolf, Andries; Krams, Robert; de Jong, Nico; van der Steen, Antonius F W

    2007-12-01

    The feasibility of subharmonic contrast intravascular ultrasound (IVUS) imaging was investigated using a prototype nonlinear IVUS system and the commercial contrast agent Definity . The system employed a mechanically scanned commercial catheter with a custom transducer element fabricated to have sensitivity at both 15 and 30 MHz. Experiments were conducted at a fundamental frequency of 30 MHz (F30; 25% bandwidth), with on-axis pressures ranging from 0.12 to 0.79 MPa, as measured with a needle hydrophone. In vitro characterization experiments demonstrated the detection of 15 MHz subharmonic signals (SH15) when pressure levels reached 360 kPa. The formation of SH15 images was shown, with tissue signals suppressed to near the noise floor and contrast to tissue ratios were improved by up to 30 dB relative to F30. In vivo experiments were performed using the atherosclerotic rabbit aorta model. Following the bolus injection of contrast agent upstream of the imaging catheter, agent was detected within the aorta, vena cava and within the perivascular space. These results provide a first in vivo demonstration of subharmonic contrast IVUS and suggest its potential as a new technique for imaging vasa vasorum.

  4. Regression of coronary atherosclerosis by simvastatin: a serial intravascular ultrasound study

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Pedersen, Knud Erik;

    2004-01-01

    BACKGROUND: Angiography of the coronary arteries reflects only changes in luminal dimensions. With intravascular ultrasound, cross-sectional images can be obtained and area measurements can be added to calculate volumes of the external elastic membrane (EEM), plaque plus media (P+M), and lumen...... in a not previously revascularized coronary artery, serial intravascular ultrasound studies with an ECG-triggered pullback were performed at baseline, after 3 months on a lipid-lowering diet, and after another 12 months on simvastatin 40 mg/d. Mean length of the analyzed atherosclerotic segments was 5.9+/-3.3 mm.......2+/-0.7 mmol/L, Ptherapy with simvastatin for 12 months is associated with a significant P+M regression in coronary arteries measured as reduction in P+M and EEM volumes without any...

  5. Development of catheters for combined intravascular ultrasound and photoacoustic imaging

    Science.gov (United States)

    Karpiouk, Andrei B.; Wang, Bo; Emelianov, Stanislav Y.

    2009-02-01

    Coronary atherosclerosis is a complex disease accompanied by the development of plaques in the arterial wall. Since the vulnerability of the plaques depends on their composition, the appropriate treatment of the arteriosclerosis requires a reliable characterization of the plaques' geometry and content. The intravascular ultrasound (IVUS) imaging is capable of providing structural details of the plaques as well as some functional information. In turn, more functional information about the same plaques can be obtained from intravascular photoacoustic (IVPA) images since the optical properties of the plaque's components differ from that of their environment. The combined IVUS/IVPA imaging is capable of simultaneously detecting and differentiating the plaques, thus determining their vulnerability. The potential of combined IVUS/IVPA imaging has already been demonstrated in phantoms and ex-vivo experiments. However, for in-vivo or clinical imaging, an integrated IVUS/IVPA catheter is required. In this paper, we introduce two prototypes of integrated IVUS/IVPA catheters for in-vivo imaging based on a commercially available single-element IVUS imaging catheter. The light delivery systems are developed using multimode optical fibers with custom-designed distal tips. Both prototypes were tested and compared using an arterial mimicking phantom. The advantages and limitations of both designs are discussed. Overall, the results of our studies suggest that both designs of integrated IVUS/IVPA catheter have a potential for in-vivo IVPA/IVUS imaging of atherosclerotic plaques.

  6. Intravascular Ultrasound in Percutaneous Coronary Intervention for Chronic Total Occlusion

    Directory of Open Access Journals (Sweden)

    M Mohandes

    2010-09-01

    Full Text Available Background: Percutaneous coronary intervention (PCI of chronic total occlusion (CTO is one of the most challenging procedures in interventional cardiology. New techniques and devices have made possible to face these complex procedures. Intravascular ultrasound (IVUS reveals special features and contributes greatly to procedural success.Method: We analysed retrospectively IVUS contribution and findings in 23 cases of a total 46 CTOs PCI from February 2009 to August 2010 in our cath lab. Both true and functional CTO were included in this study. The procedure was considered successful when a TIMI III flow was reached in the occluded vessel after stent implantation with a residual stenosis less than 30%. IVUS features and contribution in CTO-PCI were analysed. All data were introduced in SPSS version 15 (SPSS Inc. Chicago, Illinois, USA. Continuous variables were described by mean ± SD and categorical variables were expressed as percentage. A P<0.05 was considered statistically significant.Results: 46 PCIs in 34 patients were performed during 19 months in our centre. The procedure was successful in 28 cases (60.9%.. IVUS was performed in 23 (82.1% of successful procedures. IVUS revealed calcium somewhere in 17 (73.9%. Despite wire angiographic verification in true lumen distally IVUS showed subintimal wire position in part of CTO segment in 6(26.1%. In 22(95.7% of cases IVUS allowed both the wire position verification in true lumen and the vessel measurement before stent implantation. In 1(4.3% case a second wire was introduced into true lumen guided by IVUS after realising that the first wire was in false lumen. We could not find significant relation between calcium presence and subintimal wire penetration in CTO segment (p: 0.14 Conclusions: IVUS showed calcium in CTO segment in a high percentage of cases. It is not unusual to find wire penetration in subintimal space in part of CTO segment. IVUS has a key contribution in the step by step

  7. Characterization of plaque components with intravascular ultrasound elastography in human femoral and coronary arteries in vitro

    NARCIS (Netherlands)

    C.L. de Korte (Chris); G. Pasterkamp (Gerard); H.A. Woutman; N. Bom (Klaas); A.F.W. van der Steen (Ton)

    2000-01-01

    textabstractBACKGROUND: The composition of plaque is a major determinant of coronary-related clinical syndromes. Intravascular ultrasound (IVUS) elastography has proven to be a technique capable of reflecting the mechanical properties of phantom material and the femoral arterial

  8. Automated Contour Detection for Intravascular Ultrasound Image Sequences Based on Fast Active Contour Algorithm

    Institute of Scientific and Technical Information of China (English)

    DONG Hai-yan; WANG Hui-nan

    2006-01-01

    Intravascular ultrasound can provide high-resolution real-time crosssectional images about lumen, plaque and tissue. Traditionally, the luminal border and medial-adventitial border are traced manually. This process is extremely timeconsuming and the subjective difference would be large. In this paper, a new automated contour detection method is introduced based on fast active contour model.Experimental results found that lumen and vessel area measurements after automated detection showed good agreement with manual tracings with high correlation coefficients (0.94 and 0.95, respectively) and small system difference ( -0.32 and 0.56, respectively). So it can be a reliable and accurate diagnostic tool.

  9. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    OpenAIRE

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2014-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at ...

  10. Application of Near Infrared Spectroscopy, Intravascular Ultrasound and the Coronary Calcium Score to Predict Adverse Coronary Events

    Science.gov (United States)

    2015-10-01

    Award Number: W81XWH-11-1-0831 TITLE: Application of Near Infrared Spectroscopy, Intravascular Ultrasound and the Coronary Calcium Score to...3. DATES COVERED 26-SEP-2014 to 25-SEP-2015 4. TITLE AND SUBTITLE Application of Near Infrared Spectroscopy, Intravascular Ultrasound and the...planned. 15. SUBJECT TERMS coronary artery disease, near infrared spectroscopy, calcium scoring, intravascular ultrasound 16. SECURIY CLASSIFICATION OF

  11. 血管内超声测量血流动力学参数的研究进展%Progresses of intravascular ultrasound in measurement of hemodynamic parameters

    Institute of Scientific and Technical Information of China (English)

    孙正

    2013-01-01

    Intravascular ultrasound (IVUS) can record the morphology of vessel wall,lumen and plaque,composition of plaques and even wall functional features in vivo.Detecting hemodynamic parameters of coronary arteries,including elastic modulus of vessel wall and wall shear stress and strain,etc.,from intracoronary ultrasound images is important for diagnosing coronary heart diseases and planning the treatment.The progresses of quantitative measurement of hemodynamic parameters of coronary arteries from IVUS images were reviewed in this article.%血管内超声显像可在活体中观察血管壁、管腔及斑块形态、性质,甚至斑块成分和管壁功能状态,由此获得的冠状动脉的血流动力学参数(包括管壁的弹性模量和血管壁应力-应变分布等)对于正确诊断冠心病、制定最佳诊疗方案具有重要意义.本文就近年来血管内超声在冠状动脉血流动力学参数测量中的应用进行综述.

  12. Intravascular ultrasound assessed incomplete stent apposition and stent fracture in stent thrombosis after bare metal versus drug-eluting stent treatment the Nordic Intravascular Ultrasound Study (NIVUS)

    DEFF Research Database (Denmark)

    Kosonen, Petteri; Vikman, Saila; Jensen, Lisette Okkels;

    2013-01-01

    This prospective multicenter registry used intravascular ultrasound (IVUS) in patients with definite stent thrombosis (ST) to compare rates of incomplete stent apposition (ISA), stent fracture and stent expansion in patients treated with drug-eluting (DES) versus bare metal (BMS) stents. ST...... is a rare, but potential life threatening event after coronary stent implantation. The etiology seems to be multifactorial....

  13. Development of a Mechanical Scanning-type Intravascular Ultrasound System Using a Miniature Ultrasound Motor

    Science.gov (United States)

    Tanabe, Masayuki; Xie, Shangping; Tagawa, Norio; Moriya, Tadashi; Furukawa, Yuji

    2007-07-01

    Intravascular ultrasound (IVUS) plays an important role for the detection of arteriosclerosis, which causes the ischemic heart disease. In mechanical scanning-type IVUS, it is necessary to rotate a transducer or a reflecting mirror. A method that involves rotating the transducer using a torque wire causes image distortion (NURD: non uniform rotation distortion). For a method that involves placing an electromagnetic motor on the tip of an IVUS probe is difficult to miniaturize the probe. Our objectives are to miniaturize the probe (1 mm in diameter, 5 mm in length) and to remove NURD. Therefore, we conducted a study to assess the feasibility of attaining these objectives by constructing a prototype IVUS system, in which an ultrasound motor using a stator in the form of a helical coil (abbreviated as CS-USM: coiled stator-ultrasonic motor) is incorporated, and to clarify problems that need to be solved in constructing the probe.

  14. Oblong-Shaped-Focused Transducers for Intravascular Ultrasound Imaging.

    Science.gov (United States)

    Lee, Junsu; Jang, Jihun; Chang, Jin Ho

    2017-03-01

    In intravascular ultrasound (IVUS) imaging, a transducer is inserted into a blood vessel and rotated to obtain image data. For this purpose, the transducer aperture is typically less than 0.5 mm in diameter, which causes natural focusing to occur in the imaging depth ranging from 1 to 5 mm. Due to the small aperture, however, it is not viable to conduct geometric focusing in order to enhance the spatial resolution of IVUS images. Furthermore, this hampers narrowing the slice thickness of a cross-sectional scan plane in the imaging depth, which leads to lowering spatial and contrast resolutions of IVUS images. To solve this problem, we propose an oblong-shaped-focused transducer for IVUS imaging. Unlike the conventional IVUS transducers with either a circular or a square flat aperture, the proposed transducer has an oblong aperture of which long side is positioned along a blood vessel. This unique configuration makes it possible to conduct geometric focusing at a desired depth in the elevation direction. In this study, furthermore, it is demonstrated that a spherically shaped aperture in both lateral and elevation directions also improves lateral resolution, compared to the conventional flat aperture. To ascertain this, the conventional and the proposed IVUS transducers were designed and fabricated to evaluate and to compare their imaging performances through wire phantom and tissue-mimicking phantom experiments. For the proposed 50-MHz IVUS transducer, a PZT piece of 0.5 × 1.0 mm(2) was spherically shaped for elevation focus at 3 mm by using the conventional press-focusing technique whereas the conventional one has a flat aperture of 0.5 × 0.5 mm(2). The experimental results demonstrated that the proposed IVUS transducer is capable of improving spatial and contrast resolutions of IVUS images.

  15. Intravascular ultrasound predictors of CD163 positive macrophage infiltration.

    Science.gov (United States)

    Sato, Takao; Kameyama, Tomoki; Ueno, Hiroshi; Inoue, Hiroshi

    2014-06-01

    The present study aimed to determine characteristics of macrophage accumulation and predictors of CD163 positive macrophages by ultrasonic tissue characterization. Intraplaque hemorrhage is associated with plaque instability and induces macrophage accumulation with a scavenger receptor, CD163. These CD163 positive macrophages have anti-atherogenic property. In 50 patients with acute coronary syndrome, lumen, vessel and plaque area, and plaque components (% fibrous, % fibro fatty, % dense calcium, and % necrotic core) of the culprit lesion were determined by virtual histology (VH) intravascular ultrasound (IVUS). Remodeling index (RI) was also determined. Atherothrombotic debris of the culprit lesion was collected during percutaneous coronary intervention using a distal protection device. CD163 positive macrophages and glycophorin A (a protein specific to erythrocytes) were determined immunohistochemically. Percentage of CD163 positive macrophages to the whole cells (% CD163) correlated positively with lumen, vessel and plaque area, and RI. Further, % CD163 had significant positive correlation with % necrotic core and negative correlation with % dense calcium. Immunopositive areas of glycophorin A (% glycophorin A), expressed as the ratio of positively stained areas per total tissue, had a significant positive correlation with % CD163. On multivariate analysis, % necrotic core, % dense calcium, and RI were independent determinants of % CD163. Positive remodeling and large necrotic core without calcification on VH-IVUS were likely to indicate coronary intraplaque hemorrhage with CD163 positive macrophages infiltration. © 2014, Wiley Periodicals, Inc.

  16. Intravascular ultrasound-guided stenting of left main stem dissection after Medtronic Corevalve implantation.

    Science.gov (United States)

    Van Mieghem, N M; de Jaegere, P P

    2013-08-01

    Transcatheter aortic valve implantation (TAVI) implies the introduction, positioning, and deployment of a stented bioprosthesis in the (calcified) native aortic valve. We report an at first glance uneventful TAVI with the Medtronic Corevalve System, which was followed by transient electrocardiographic changes suggesting acute left main stem disease. The diagnosis of acute left main stem dissection extending from the left coronary cusp was firmly established by intravascular ultrasound. The ostium of the left main stem was successfully treated with intravascular ultrasound-guided placement of a drug eluting stent. © 2013 Wiley Periodicals, Inc.

  17. All-optical pulse-echo ultrasound probe for intravascular imaging (Conference Presentation)

    Science.gov (United States)

    Colchester, Richard J.; Noimark, Sacha; Mosse, Charles A.; Zhang, Edward Z.; Beard, Paul C.; Parkin, Ivan P.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

    2016-02-01

    High frequency ultrasound probes such as intravascular ultrasound (IVUS) and intracardiac echocardiography (ICE) catheters can be invaluable for guiding minimally invasive medical procedures in cardiology such as coronary stent placement and ablation. With current-generation ultrasound probes, ultrasound is generated and received electrically. The complexities involved with fabricating these electrical probes can result in high costs that limit their clinical applicability. Additionally, it can be challenging to achieve wide transmission bandwidths and adequate wideband reception sensitivity with small piezoelectric elements. Optical methods for transmitting and receiving ultrasound are emerging as alternatives to their electrical counterparts. They offer several distinguishing advantages, including the potential to generate and detect the broadband ultrasound fields (tens of MHz) required for high resolution imaging. In this study, we developed a miniature, side-looking, pulse-echo ultrasound probe for intravascular imaging, with fibre-optic transmission and reception. The axial resolution was better than 70 microns, and the imaging depth in tissue was greater than 1 cm. Ultrasound transmission was performed by photoacoustic excitation of a carbon nanotube/polydimethylsiloxane composite material; ultrasound reception, with a fibre-optic Fabry-Perot cavity. Ex vivo tissue studies, which included healthy swine tissue and diseased human tissue, demonstrated the strong potential of this technique. To our knowledge, this is the first study to achieve an all-optical pulse-echo ultrasound probe for intravascular imaging. The potential for performing all-optical B-mode imaging (2D and 3D) with virtual arrays of transmit/receive elements, and hybrid imaging with pulse-echo ultrasound and photoacoustic sensing are discussed.

  18. Orbital Atherectomy Plaque Modification Assessment of the Femoropopliteal Artery Via Intravascular Ultrasound (TRUTH Study)

    OpenAIRE

    Babaev, Anvar; Zavlunova, Susanna; Attubato, Michael J.; Martinsen, Brad J.; Mintz,Gary S.; Maehara, Akiko

    2015-01-01

    Objective: The Tissue Removal Assessment with Ultrasound of the SFA and Popliteal (TRUTH) study assessed the performance of the orbital atherectomy system (OAS) to treat femoropopliteal arteries, including determining its effect on plaque removal. Methods: Patients with symptomatic femoropopliteal peripheral arterial disease were treated with the OAS followed by adjunctive balloon angioplasty (BA). Intravascular ultrasound (IVUS) images were collected pre- and post-OAS and post-OAS BA. Patien...

  19. Identification of atherosclerotic plaque components with intravascular ultrasound elastography in vivo: a Yucatan pig study.

    NARCIS (Netherlands)

    Korte, C.L. de; Sierevogel, M.J.; Mastik, F.; Strijder, C.; Schaar, J.A.; Velema, E.; Pasterkamp, G.; Serruys, P.W.; Steen, A.F.W. van der

    2002-01-01

    BACKGROUND: Intravascular ultrasound elastography assesses the local strain of the atherosclerotic vessel wall. In the present study, the potential to identify different plaque components in vivo was investigated. METHODS AND RESULTS: Atherosclerotic external iliac and femoral arteries (n=24) of 6 Y

  20. Serial intravascular ultrasound assessment of changes in coronary atherosclerotic plaque dimensions and composition: an update

    DEFF Research Database (Denmark)

    Hartmann, Marc; Huisman, Jennifer; Böse, Dirk;

    2011-01-01

    This manuscript reviews the use of serial intravascular ultrasound (IVUS) examination of coronary atherosclerosis in recent observational studies and randomized trials that revealed the effects of cholesterol-lowering and lipid-modifying therapies and offered novel insight into plaque progression...

  1. Three-dimensional quantitative coronary angiography and the registration with intravascular ultrasound and optical coherence tomography

    NARCIS (Netherlands)

    Tu, Shengxian

    2012-01-01

    This thesis proposes several new algorithms including X-ray angiographic image enhancement, three-dimensional (3D) angiographic reconstruction, angiographic overlap prediction, and the co-registration of X-ray angiography with intracoronary imaging devices, such as intravascular ultrasound (IVUS) an

  2. Coronary plaque composition as assessed by greyscale intravascular ultrasound and radiofrequency spectral data analysis

    NARCIS (Netherlands)

    N. Gonzalo (Nieves); H.M. Garcia-Garcia (Hector); J.M.R. Ligthart (Jürgen); G.A. Rodriguez-Granillo (Gaston); E. Meliga (Emanuele); Y. Onuma (Yoshinobu); J.C.H. Schuurbiers (Johan); N. Bruining (Nico); P.W.J.C. Serruys (Patrick)

    2008-01-01

    textabstractObjectives: (i) To explore the relation between greyscale intravascular ultrasound (IVUS) plaque qualitative classification and IVUS radiofrequency data (RFD) analysis tissue types; (ii) to evaluate if plaque composition as assessed by RFD analysis can be predicted by visual assessment o

  3. Recanalized chronic coronary thrombus: unraveling a hazy coronary lesion by intravascular ultrasound.

    Science.gov (United States)

    Karamasis, Grigoris V; Chotai, Shayna; Khokhar, Azhar A; Kelly, Paul A

    2016-04-01

    Hazy lesions in coronary angiography can often be a puzzle for the interventional cardiologist. Recanalized chronic coronary thrombus, although rare, is one of the potential diagnoses. Intracoronary imaging with intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are tools that can guide to the correct diagnosis. We present the images of a case where IVUS was used to unravel such a lesion.

  4. Monolithic CMUT-on-CMOS integration for intravascular ultrasound applications.

    Science.gov (United States)

    Zahorian, Jaime; Hochman, Michael; Xu, Toby; Satir, Sarp; Gurun, Gokce; Karaman, Mustafa; Degertekin, F Levent

    2011-12-01

    One of the most important promises of capacitive micromachined ultrasonic transducer (CMUT) technology is integration with electronics. This approach is required to minimize the parasitic capacitances in the receive mode, especially in catheter-based volumetric imaging arrays, for which the elements must be small. Furthermore, optimization of the available silicon area and minimized number of connections occurs when the CMUTs are fabricated directly above the associated electronics. Here, we describe successful fabrication and performance evaluation of CMUT arrays for intravascular imaging on custom-designed CMOS receiver electronics from a commercial IC foundry. The CMUT-on-CMOS process starts with surface isolation and mechanical planarization of the CMOS electronics to reduce topography. The rest of the CMUT fabrication is achieved by modifying a low-temperature micromachining process through the addition of a single mask and developing a dry etching step to produce sloped sidewalls for simple and reliable CMUT-to-CMOS interconnection. This CMUT-to-CMOS interconnect method reduced the parasitic capacitance by a factor of 200 when compared with a standard wire-bonding method. Characterization experiments indicate that the CMUT-on-CMOS elements are uniform in frequency response and are similar to CMUTs simultaneously fabricated on standard silicon wafers without electronics integration. Ex- periments on a 1.6-mm-diameter dual-ring CMUT array with a center frequency of 15 MHz show that both the CMUTs and the integrated CMOS electronics are fully functional. The SNR measurements indicate that the performance is adequate for imaging chronic total occlusions located 1 cm from the CMUT array.

  5. Transbiliary intravascular ultrasound-guided diagnostic biopsy of an inaccessible pancreatic head mass

    Directory of Open Access Journals (Sweden)

    Jeffrey Forris Beecham Chick, MD, MPH, DABR

    2017-06-01

    Full Text Available Percutaneous image-guided biopsies of pancreatic malignancies may prove challenging and nondiagnostic due to a variety of anatomic considerations. For patients with complex post-surgical anatomy, such as a Roux-en-Y gastric bypass, diagnosis via endoscopic ultrasound with fine-needle aspiration may not be possible because of an inability to reach the proximal duodenum. This report describes the first diagnostic case of transbiliary intravascular ultrasound-guided biopsy of a pancreatic head mass in a patient with prior Roux-en-Y gastric bypass for which a diagnosis could not be achieved via percutaneous and endoscopic approaches. Transbiliary intravascular ultrasound-guided biopsy resulted in a diagnosis of pancreatic adenocarcinoma, allowing the initiation of chemotherapy.

  6. Design of low noise transimpedance amplifier for intravascular ultrasound

    KAUST Repository

    Reda, Dina

    2009-11-01

    In this paper, we study transimpedance amplifiers for capacitive sensing applications with a focus on Intravascular Ultra Sound (IVUS). We employ RF noise cancellation technique on capacitive feedback based transimpedance amplifiers. This technique eliminates the input-referred noise of TIAs completely and enhances the dynamic range of front-end electronics. Simulation results verify the proposed technique used in two different TIA topologies employing shunt-shunt feedback. ©2009 IEEE.

  7. The effect of vascular curvature on three-dimensional reconstruction of intravascular ultrasound images.

    Science.gov (United States)

    Wiet, S P; Vonesh, M J; Waligora, M J; Kane, B J; McPherson, D D

    1996-01-01

    To characterize the effect of vessel curvature on the geometric accuracy of conventional three-dimensional reconstruction (3DR) algorithms for intravascular ultrasound image data. A common method of 3DR for intravascular ultrasound image data involves geometric reassembly and volumetric interpolation of a spatially related sequence of tomographic cross sections generated by an ultrasound catheter withdrawn at a constant rate through a vascular segment of interest. The resulting 3DR is displayed as a straight segment, with inherent vascular curvature neglected. Most vascular structures, however, are not straight but curved to some degree. For this reason, vascular curvature may influence the accuracy of computer-generated 3DR. We collected image data using three different intravascular ultrasound catheters (2.9 Fr, 4.3 Fr, 8.0 Fr) during a constant-rate pullback of 1 mm/sec through tubing of known diameter with imposed radii of curvature ranging from 2 to 10 cm. Image data were also collected from straight tubing. Image data were digitized at 1.0-mm intervals through a length of 25 mm. Two passes through each radius of curvature were performed with each intravascular ultrasound catheter. 3DR lumen volume for each radius of curvature was compared to that theoretically expected from a straight cylindrical segment. Differences between 3DR lumen volume of theoretical versus curved (actual) tubes were quantified as absolute percentage error and categorized as a function of curvature. Tubing deformation error was quantified by quantitative coronary angiography (QCA). Volumetric errors ranged from 1% to 35%, with an inverse relationship demonstrated between 3DR lumen volume and segmental radius of curvature. Higher curvatures (r curvatures (r > 6.0 cm). This trend was exhibited for all three catheters and was shown to be independent of tubing deformation artifacts. QCA-determined percentage diameter stenosis indicated no deformation error as a function of curvature. Total

  8. Study of restenosis in drug eluting stents: new insights from greyscale intravascular ultrasound and virtual histology.

    Science.gov (United States)

    Garcia-Garcia, Hector M; Shen, Zhujun; Piazza, Nicolo

    2009-05-01

    In current cardiology practice, many patients undergo secondary revascularisation due to reduced long-term vein graft patency or in-stent restenosis. In this report, we describe causes of drug-eluting stent restenosis identifiable by intravascular ultrasound imaging (IVUS) and variables related to restenosis used for reporting greyscale IVUS. In addition, IVUS findings in bypass grafts and the long-term results after stent implantation are provided. Finally, the usefulness of IVUS virtual histology for the study of restenosis is described.

  9. Detection of coronary plaques using MR coronary vessel wall imaging: validation of findings with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Gerretsen, Suzanne; Engelshoven, Jos M.A. van; Kooi, M.E. [Maastricht University Medical Centre, Department of Radiology, Maastricht (Netherlands); Maastricht University, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); Kessels, Alfons G. [Maastricht University Medical Centre, Department of Clinical Epidemiology and Medical Technical Assessment, Maastricht (Netherlands); Nelemans, Patty J. [Maastricht University, Department of Epidemiology, Maastricht (Netherlands); Dijkstra, Jouke; Reiber, Johan H.C.; Geest, Rob J. van der [Leiden University Medical Centre, Department of Radiology, Division of image processing (LKEB), Leiden (Netherlands); Katoh, Marcus [HELIOS Clinic, Department of Diagnostic and Interventional Radiology, Krefeld (Germany); Waltenberger, Johannes [University of Muenster, Department of Cardiology and Angiology, Muenster (Germany); Botnar, Rene M. [King' s College, Imaging Sciences Division, London (United Kingdom); Leiner, Tim [Maastricht University Medical Centre, Department of Radiology, Maastricht (Netherlands); Maastricht University, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); Utrecht University Medical Centre, Department of Radiology, Utrecht (Netherlands)

    2013-01-15

    Compared with X-ray coronary angiography (CAG), magnetic resonance imaging of the coronary vessel wall (MR-CVW) may provide more information about plaque burden and coronary remodelling. We compared MR-CVW with intravascular ultrasound (IVUS), the standard of reference for coronary vessel wall imaging, with regard to plaque detection and wall thickness measurements. In this study 17 patients with chest pain, who had been referred for CAG, were included. Patients underwent IVUS and MR-CVW imaging of the right coronary artery (RCA). Subsequently, the coronary vessel wall was analysed for the presence and location of coronary plaques. Fifty-two matching RCA regions of interest were available for comparison. There was good agreement between IVUS and MR-CVW for qualitative assessment of presence of disease, with a sensitivity of 94% and specificity of 76%. Wall thickness measurements demonstrated a significant difference between mean wall thickness on IVUS and MR-CVW (0.48 vs 1.24 mm, P < 0.001), but great heterogeneity between wall thickness measurements, resulting in a low correlation between IVUS and MR-CVW. MR-CVW has high sensitivity for the detection of coronary vessel wall thickening in the RCA compared with IVUS. However, the use of MRI for accurate absolute wall thickness measurements is not supported when a longitudinal acquisition orientation is used. (orig.)

  10. Fixed Coronary Artery Stenosis in Tunneled Coronary Artery Identified by Intravascular Ultrasound: A Case Report

    Directory of Open Access Journals (Sweden)

    Yuxiang Dai

    2014-10-01

    Full Text Available Myocardial bridging is characterized as the compression of a segment of the coronary artery during systole. Significant atherosclerosis within the bridge is almost never seen at pathologic examination because of the absence of synthetic type smooth muscle cells in the intima of the tunneled artery. To date, there have been no reports of significant atherosclerosis at the site of myocardial bridging documented by angiography or intravenous ultrasound. We report a rare case of fixed coronary artery stenosis at the site of myocardial bridging identified by intravascular ultrasound.

  11. Potential for tissue characterization of plaque and arterial wall using intravascular ultrasound

    Science.gov (United States)

    Sudhir, Krishnakutty; Fitzgerald, Peter J.; Yock, Paul G.

    1993-09-01

    Current intravascular ultrasound imaging technology is able to determine the extent and distribution of pathologic processes within the vessel wall, but is not highly sensitive in discriminating between different types of pathologic tissue. `Tissue characterization' refers to a set of computer-based techniques that utilize features of the ultrasound signal beyond basic amplitude to help define the structure of the tissue of interest. Although preliminary results with this approach are encouraging, additional work is needed to define its clinical application in vascular disease.

  12. In vitro atherosclerotic plaque and calcium quantitation by intravascular ultrasound and electron-beam computed tomography.

    Science.gov (United States)

    Gutfinger, D E; Leung, C Y; Hiro, T; Maheswaran, B; Nakamura, S; Detrano, R; Kang, X; Tang, W; Tobis, J M

    1996-05-01

    The purpose of this investigation was to compare the accuracy of intravascular ultrasound (IVUS) and electron-beam computed tomography (EBCT) in quantitating human atherosclerotic plaque and calcium. In experiment 1, 12 human atherosclerotic arterial segments were obtained at autopsy and imaged by using IVUS and EBCT. The plaque from each arterial segment was dissected and a volume measurement of the dissected plaque was obtained by water displacement. The plaque from each arterial segment was ashed at 700 degrees F, and the weight of the remaining ashes was used as an estimate of the calcium mass. In experiment II, 11 calcified arterial segments were obtained at autopsy and imaged by using IVUS at one site along the artery. A corresponding histologic cross section stained with Masson's trichrome was prepared. In experiment I, the mean plaque volume measured by water displacement was 165.3 +/- 118.4 microliters. The mean plaque volume calculated by IVUS was 166.1 +/- 114.4 microliters and correlated closely with that by water displacement (r = 0.98, p volume by IVUS was 18.6 +/- 11.2 microliters and correlated linearly with the calcium mass by ashing (r = 0.87, p volume as well as the cross-sectional area and volume of intralesional calcium, especially if the calcium is localized at the base of the plaque. IVUS underestimates the amount of calcium present because of signal drop-off when the calcium is too thick for the ultrasound to completely penetrate. In comparison, EBCT accurately quantitates calcium mass regardless of the intralesional calcium morphologic characteristics; however, EBCT does not accurately quantitate plaque volume and will miss noncalcified atherosclerotic lesions.

  13. Comparison of Segmental Versus Longitudinal Intravascular Ultrasound Analysis for Pediatric Cardiac Allograft Vasculopathy.

    Science.gov (United States)

    Kuhn, M A; Burch, M; Chinnock, R E; Fenton, M J

    2017-10-01

    Intravascular ultrasound (IVUS) has been routinely used in some centers to investigate cardiac allograft vasculopathy in pediatric heart transplant recipients. We present an alternative method using more sophisticated imaging software. This study presents a comparison of this method with an established standard method. All patients who had IVUS performed in 2014 were retrospectively evaluated. The standard technique consisted of analysis of 10 operator-selected segments along the vessel. Each study was re-evaluated using a longitudinal technique, taken at every third cardiac cycle, along the entire vessel. Semiautomatic edge detection software was used to detect vessel imaging planes. Measurements included outer and inner diameter, total and luminal area, maximal intimal thickness (MIT), and intimal index. Each IVUS was graded for severity using the Stanford classification. All results were given as mean ± standard deviation (SD). Groups were compared using Student t test. A P value grading severity of cardiac allograft vasculopathy in pediatric heart transplant recipients. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

    Science.gov (United States)

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

    2014-07-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT.

  15. Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging.

    Science.gov (United States)

    Yoon, Sangpil; Williams, Jay; Kang, Bong Jin; Yoon, Changhan; Cabrera-Munoz, Nestor; Jeong, Jong Seob; Lee, Sang Goo; Shung, K Kirk; Kim, Hyung Ham

    2015-06-01

    A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast.

  16. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    Science.gov (United States)

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  17. Relationship between coronary angioscopic and intravascular ultrasound imaging and restenosis.

    Science.gov (United States)

    Xu, S; Nomura, M; Kurokawa, H; Ando, T; Kimura, M; Ishii, J; Hasegawa, H; Kondo, T; Tadiki, S; Qi, P

    1995-10-01

    In order to investigate the relationship between restenosis and the morphology detected by coronary angioscopy (CASC) and introvascular ultrasound imaging (IVUS), 17 patients were detected by CASC and IVUS immediately and 3 months after percutaneous transluminal coronary angioscopy (PTCA). The results showed that the dilation index by IVUS (DIu) was significantly lower in restenosis patients than in non-restenosis patients (0.42 +/- 0.08 versus 0.78 +/- 0.16, P < 0.01) and that the elastic recoil (ER) was higher in restenosis patients than in non-restenosis patients (4.51 +/- 1.42 mm2 versus 1.63 +/- 1.20 mm2, P < 0.01), and that the elastic recoil rate (ERR) was also higher in restenosis patients than in non-restenosis patients (57.3 +/- 8.07% versus 21.80 +/- 16.84% P < 0.01), and that coronary dissection, atheromatous plaque and calcification as well as the colour of inner coronary artery had no relation with chronic restenosis. In conclusion, the elastic recoil is one of the important factors of chronic restenosis after PTCA.

  18. Offline fusion of co-registered intravascular ultrasound and frequency domain optical coherence tomography images for the analysis of human atherosclerotic plaques

    DEFF Research Database (Denmark)

    Räber, Lorenz; Heo, Jung Ho; Radu, Maria D

    2012-01-01

    To demonstrate the feasibility and potential usefulness of an offline fusion of matched optical coherence tomography (OCT) and intravascular ultrasound (IVUS)/virtual histology (IVUS-VH) images.......To demonstrate the feasibility and potential usefulness of an offline fusion of matched optical coherence tomography (OCT) and intravascular ultrasound (IVUS)/virtual histology (IVUS-VH) images....

  19. Lead-Free Intravascular Ultrasound Transducer Using BZT-50BCT Ceramics

    Science.gov (United States)

    Yan, Xingwei; Lam, Kwok Ho; Li, Xiang; Chen, Ruimin; Ren, Wei; Ren, Xiaobing; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    This paper reports the fabrication and evaluation of a high-frequency ultrasonic transducer based on a new lead-free piezoelectric material for intravascular imaging application. Lead-free 0.5Ba(Zr0.2Ti0.8)O3−0.5(Ba0.7Ca0.3)TiO3 (BZT-50BCT) ceramic with a high dielectric constant (~2800) was employed to develop a high-frequency (~30 MHz) needle-type ultrasonic transducer. With superior piezoelectric performance (piezoelectric coefficient d33 ~ 600 pC/N), the lead-free transducer was found to exhibit a −6-dB bandwidth of 53% with an insertion loss of 18.7 dB. In vitro intravascular ultrasound (IVUS) imaging of a human cadaver coronary artery was performed to demonstrate the potential of the lead-free transducer for biomedical imaging applications. This is the first time that a lead-free transducer has been used for IVUS imaging application. The experimental results suggest that the BZT-50BCT ceramic is a promising lead-free piezoelectric material for high-frequency intravascular imaging applications. PMID:25004492

  20. Abnormal pulmonary artery stiffness in pulmonary arterial hypertension: in vivo study with intravascular ultrasound.

    Directory of Open Access Journals (Sweden)

    Edmund M T Lau

    Full Text Available BACKGROUND: There is increasing recognition that pulmonary artery stiffness is an important determinant of right ventricular (RV afterload in pulmonary arterial hypertension (PAH. We used intravascular ultrasound (IVUS to evaluate the mechanical properties of the elastic pulmonary arteries (PA in subjects with PAH, and assessed the effects of PAH-specific therapy on indices of arterial stiffness. METHOD: Using IVUS and simultaneous right heart catheterisation, 20 pulmonary segments in 8 PAH subjects and 12 pulmonary segments in 8 controls were studied to determine their compliance, distensibility, elastic modulus and stiffness index β. PAH subjects underwent repeat IVUS examinations after 6-months of bosentan therapy. RESULTS: AT BASELINE, PAH SUBJECTS DEMONSTRATED GREATER STIFFNESS IN ALL MEASURED INDICES COMPARED TO CONTROLS: compliance (1.50±0.11×10(-2 mm(2/mmHg vs 4.49±0.43×10(-2 mm(2/mmHg, p<0.0001, distensibility (0.32±0.03%/mmHg vs 1.18±0.13%/mmHg, p<0.0001, elastic modulus (720±64 mmHg vs 198±19 mmHg, p<0.0001, and stiffness index β (15.0±1.4 vs 11.0±0.7, p = 0.046. Strong inverse exponential associations existed between mean pulmonary artery pressure and compliance (r(2 = 0.82, p<0.0001, and also between mean PAP and distensibility (r(2 = 0.79, p = 0.002. Bosentan therapy, for 6-months, was not associated with any significant changes in all indices of PA stiffness. CONCLUSION: Increased stiffness occurs in the proximal elastic PA in patients with PAH and contributes to the pathogenesis RV failure. Bosentan therapy may not be effective at improving PA stiffness.

  1. Intravascular ultrasound for iliac artery imaging. Clinical review

    DEFF Research Database (Denmark)

    Vogt, K G; Schroeder, T V

    2001-01-01

    PTA. Structures such as rupture, intimal flaps and dissection are better visualized with IVUS. In stenotic iliac arteries IVUS has been able to evaluate the effect of PTA and stenting and relating the effect to the morphology of the plaque. IVUS measurements seem to be important predictors...... of the patency of iliac PTA. The ability of IVUS to evaluate the adaptation of stents to the arterial wall makes it particularly suited as a control procedure for the deployment of endovascular stented grafts. Finally IVUS has the ability to disclose insufficiency of endarterecomy, by visualizing remaining...

  2. Fully integrated optical coherence tomography, ultrasound, and indocyanine green-based fluorescence tri-modality system for intravascular imaging.

    Science.gov (United States)

    Li, Yan; Jing, Joseph; Qu, Yueqiao; Miao, Yusi; Zhang, Buyun; Ma, Teng; Yu, Mingyue; Zhou, Qifa; Chen, Zhongping

    2017-02-01

    We present a tri-modality imaging system and fully integrated tri-modality probe for intravascular imaging. The tri-modality imaging system is able to simultaneously acquire optical coherence tomography (OCT), ultrasound (US), and fluorescence imaging. Moreover, for fluorescence imaging, we used the FDA-approved indocyanine green (ICG) dye as the contrast agent to target lipid-loaded macrophages. We conducted imaging from a male New Zealand white rabbit to evaluate the performance of the tri-modality system. In addition, tri-modality images of rabbit aortas were correlated with hematoxylin and eosin (H&E) histology to check the measurement accuracy. The fully integrated miniature tri-modality probe, together with the use of ICG dye suggest that the system is of great potential for providing a more accurate assessment of vulnerable plaques in clinical applications.

  3. Intravascular ultrasound radiofrequency analysis after optimal coronary stenting with initial quantitative coronary angiography guidance: An ATHEROREMO sub-study

    NARCIS (Netherlands)

    G. Sarno (Giovanna); S.A. Garg (Scot); J. Gomez-Lara (Josep); H.M. Garcia-Garcia (Hector); J.M.R. Ligthart (Jürgen); N. Bruining (Nico); Y. Onuma (Yoshinobu); K. Witberg (Karen); R.J.M. van Geuns (Robert Jan); S.P.M. de Boer (Sanneke); J.J. Wykrzykowska (Joanna); C.J. Schultz (Carl); H.J. Duckers (Henricus); E.S. Regar (Eveline); P.P.T. de Jaegere (Peter); P.J. de Feyter (Pim); G.A. van Es (Gerrit Anne); H. Boersma (Eric); W.J. van der Giessen (Wim); P.W.J.C. Serruys (Patrick)

    2011-01-01

    textabstractAims: To investigate whether the use of intravascular ultrasound virtual histology (IVUS-VH) leads to any improvements in stent deployment, when performed in patients considered to have had an optimal percutaneous coronary intervention (PCI) by quantitative coronary angiography (QCA). Me

  4. Successful percutaneous transluminal angioplasty and stenting for symptomatic intracranial vertebral artery stenosis using intravascular ultrasound virtual histology.

    Science.gov (United States)

    Takayama, Katsutoshi; Taoka, Toshiaki; Nakagawa, Hiroyuki; Myouchin, Kaoru; Wada, Takeshi; Sakamoto, Masahiko; Fukusumi, Akio; Iwasaki, Satoru; Kurokawa, Shinichiro; Kichikawa, Kimihiko

    2007-06-01

    This is the first report of percutaneous transluminal angioplasty (PTA) of an intracranial artery applying intravascular ultrasound virtual histology (IVUS-VH), which has been recently developed for tissue characterization of coronary artery plaque. We report a case of successful PTA and stenting for symptomatic intracranial vertebral artery stenosis using IVUS-VH.

  5. The expanding indications for virtual histology intravascular ultrasound for plaque analysis prior to carotid stenting.

    Science.gov (United States)

    Schiro, B J; Wholey, M H

    2008-12-01

    Complications of carotid artery stenting (CAS), including stroke, remain relatively high when compared with carotid endarterectomy (CEA). Current selection criteria for patients undergoing CAS are based predominately on surgical risk related to other comorbidities. Little attention is given to the morphology of the atherosclerotic plaque, although studies have shown that extensive variability exists which confers certain risks for plaque vulnerability. Virtual Histology intravascular ultrasound (VH IVUS) offers a unique method of assessing plaque morphology prior to CAS. Herein, the authors review the concepts of atherosclerotic plaque morphology and discuss the background of VH IVUS and illustrate its use in the carotid system. With selection of the appropriate patient and the appropriate plaque, more favorable outcomes of CAS may be achieved which will solidify its place as a frontline treatment of carotid vascular disease.

  6. A state-of-the-art review on segmentation algorithms in intravascular ultrasound (IVUS) images.

    Science.gov (United States)

    Katouzian, Amin; Angelini, Elsa D; Carlier, Stéphane G; Suri, Jasjit S; Navab, Nassir; Laine, Andrew F

    2012-09-01

    Over the past two decades, intravascular ultrasound (IVUS) image segmentation has remained a challenge for researchers while the use of this imaging modality is rapidly growing in catheterization procedures and in research studies. IVUS provides cross-sectional grayscale images of the arterial wall and the extent of atherosclerotic plaques with high spatial resolution in real time. In this paper, we review recently developed image processing methods for the detection of media-adventitia and luminal borders in IVUS images acquired with different transducers operating at frequencies ranging from 20 to 45 MHz. We discuss methodological challenges, lack of diversity in reported datasets, and weaknesses of quantification metrics that make IVUS segmentation still an open problem despite all efforts. In conclusion, we call for a common reference database, validation metrics, and ground-truth definition with which new and existing algorithms could be benchmarked.

  7. Intravascular ultrasound assessment of remodelling and reference segment plaque burden in type-2 diabetic patients

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Mintz, Gary S;

    2007-01-01

    with type-2 diabetes mellitus. METHODS AND RESULTS: We used pre-intervention IVUS to study 62 de novo lesions in 43 patients with type-2 diabetes mellitus. The lesion site was the image slice with the smallest lumen cross-sectional area (CSA). The proximal and distal reference segments were the most normal...... size [slope = -0.12 (95% CI -0.17 to -0.07); P type-2 diabetes mellitus. CONCLUSION: Lesions in type-2 diabetic patients are different from previous reports in non-diabetics. Lesions in type-2 diabetics are characterized by a large reference segment plaque burden......AIMS: Intravascular ultrasound (IVUS) assesses arterial remodelling by comparing the lesion external elastic membrane (EEM) with the reference segments; however, reference segments are rarely disease-free. The aim was to assess lesion and reference segment remodelling and plaque burden in patients...

  8. Intravascular ultrasound assessment of very late bare-metal stent thrombosis: a case report

    Institute of Scientific and Technical Information of China (English)

    Ji Hyun Lee; Kyung Min Kim; Jun Won Lee; Sung Gyun Ahn; Young Jin Youn

    2012-01-01

    Very late stent thrombosis (VLST) is increasingly being regarded as a complication of drug-eluting stents (DES),and delayed endothelization,local hypersensitivity reactions,and late stent malapposition due to excessive positive remodeling have been postulated as mechanisms.Considering that stent endothelialization seems to be completed within 4 weeks following bare-metal stent (BMS) placement and that BMS do not possess antiproliferative coating,the mechanism of VLST may differ between patients with DES and those with BMS.We report a case of VLST 9 years after BMS implantation,in which thrombus from the ruptured neointima was confirmed by intravascular ultrasound.This finding suggests that de novo plaque rupture at the neointimal layer within the stent may be one of the explanations for VLST.

  9. (100)-Textured KNN-based thick film with enhanced piezoelectric property for intravascular ultrasound imaging

    Science.gov (United States)

    Zhu, Benpeng; Zhang, Zhiqiang; Ma, Teng; Yang, Xiaofei; Li, Yongxiang; Shung, K. Kirk; Zhou, Qifa

    2015-04-01

    Using tape-casting technology, 35 μm free-standing (100)-textured Li doped KNN (KNLN) thick film was prepared by employing NaNbO3 (NN) as template. It exhibited similar piezoelectric behavior to lead containing materials: a longitudinal piezoelectric coefficient (d33) of ˜150 pm/V and an electromechanical coupling coefficient (kt) of 0.44. Based on this thick film, a 52 MHz side-looking miniature transducer with a bandwidth of 61.5% at -6 dB was built for Intravascular ultrasound (IVUS) imaging. In comparison with 40 MHz PMN-PT single crystal transducer, the rabbit aorta image had better resolution and higher noise-to-signal ratio, indicating that lead-free (100)-textured KNLN thick film may be suitable for IVUS (>50 MHz) imaging.

  10. Assessment of the absorption process following bioabsorbable everolimus-eluting stent implantation: Temporal changes in strain values and tissue composition using intravascular ultrasound radiofrequency data analysis A substudy of the ABSORB clinical trial

    NARCIS (Netherlands)

    H.M. Garcia-Garcia (Hector); N. Gonzalo (Nieves); R. Pawar (Ravindra); N. Kukreja (Neville); D. Dudek (Dariusz); L. Thuesen (Leif); J.A. Ormiston (John); E.S. Regar (Eveline); P.W.J.C. Serruys (Patrick)

    2009-01-01

    textabstractAims: The main objective was to use IVUS-backscatter radiofrequency (IVUS-RF) to assess the degradation of a bioabsorbable stent by measuring serial changes in dense calcium (DC) and necrotic core (NC) as assessed by intravascular ultrasound-Virtual Histology™ (IVUS-VH) and in the strain

  11. Infrainguinal CTO Recanalization Assessed by Intravascular Ultrasound: Results of the CENTRAL Study.

    Science.gov (United States)

    Torey, James; Zaitoun, Anwar; Lalonde, Thomas; Runyon, John; Mustapha, Jihad; Davis, Thomas

    2016-11-01

    CENTRAL was a prospective, multicenter, 100 patient study designed to evaluate the ability of a recanalization catheter system to cross chronic total occlusions (CTOs) of the superficial femoral artery while staying within the central vessel lumen. The primary endpoint was the successful crossing of a CTO (≥90% of the length) with the recanalization catheter in the central lumen of the superficial femoral artery in at least one-half of the studied patient population, confirmed by intravascular ultrasound. Secondary endpoints included standardized anatomic damage assessment (the TAPE method) and an assessment of the relationship between the percent of CTO crossing and TAPE scores to the rate of target-lesion revascularization (TLR) at 30 days and 6 months. The mean age of the occlusions was 16.6 ± 22.28 months (range, 1-120 months), the average occlusion length reported by the sites was 132.1 ± 87.69 mm (range, 4-300 mm), and a majority of lesions were moderately (42.0%) or severely (32.0%) calcified. In 43/85 (50.6%) of the evaluable intravascular ultrasound images, the recanalization catheter successfully navigated the central lumen of the CTO (ie, ≥90% luminal crossing) with >50% luminal crossing in 64/85 (75.3%) of cases. The 6-month TLR rate was significantly lower in patients where the CTO was crossed ≥90% in the central vessel lumen (4.7%) compared with crossings CTO crossings achieved intraluminal crossings in >50% of cases and decreased anatomic damage, which appeared to offer a significant advantage in 6-month TLR rates.

  12. Effect of Intravascular Ultrasound-assisted Thoracic Endovascular Aortic Repair for "Complicated" Type B Aortic Dissection

    Institute of Scientific and Technical Information of China (English)

    Bao-Lei Guo; Zhen-Yu Shi; Da-Qiao Guo; Li-Xin Wang; Xiao Tang; Wei-Miao Li; Wei-Guo Fu

    2015-01-01

    Background:Intravascular ultrasound (IVUS) examination can provide useful information during endovascular stent graft repair.However,its actual clinical utility in thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (type B-AD) remains unclear,especially in complicated aortic dissection.We evaluated the effect of IVUS as a complementary tool during TEVAR.Methods:From September 2011 to April 2012,we conducted a prospective cohort study of 47 consecutive patients with "complicated" type B-AD diagnosed.We divided the patients into two groups:IVUS-assisted TEVAR group and TEVAR using angiography alone group.The general procedure of TEVAR was performed.We evaluated the perioperative and follow-up events.Patient demographics,comorbidities,preoperative images,dissection morphology,details of operative strategy,intraoperative events,and postoperative course were recorded.Results:A total of 47 patients receiving TEVAR were enrolled.Among them (females,8.51%;mean age,57.38 ± 13.02 years),13 cases (27.66%) were selected in the IVUS-assisted TEVAR group,and 34 were selected in the TEVAR group.All patients were symptomatic.The average diameter values of IVUS measurements in the landing zone were greater than those estimated by computed tomography angiography (31.82 ± 4.21 mm vs.30.64 ± 4.13 mm,P < 0.001).The technique success rate was 100%.Among the postoperative outcomes,statistical differences were only observed between the IVUS-assisted TEVAR group and TEVAR group for total operative time and the amount of contrast used (P =0.013 and P < 0.001,respectively).The follow-up ranged from 15 to 36 months for the IVUS-assisted TEVAR group and from 10 to 35 months for the TEVAR group (P =0.646).The primary endpoints were no statistical difference in the two groups.Conclusions:Intraoperative IVUS-assisted TEVAR is clinically feasible and safe.For the endovascular repair of"complicated" type B-AD,IVUS may be helpful for understanding dissection

  13. Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro

    NARCIS (Netherlands)

    T.P.M. Goderie; G. van Soest (Gijs); H.M. Garcia-Garcia (Hector); N. Gonzalo (Nieves); S. Koljenovic (Senada); G.J.H.L. Leenders (Geert); F. Mastik (Frits); E.S. Regar (Eveline); J.W. Oosterhuis (Wolter); P.W.J.C. Serruys (Patrick); A.F.W. van der Steen (Ton)

    2010-01-01

    textabstractThis study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods h

  14. Intravascular ultrasound-guided angioplasty of hemodialysis loop graft in a patient with contrast allergy.

    Science.gov (United States)

    Casey, Patrick E; Miranda, Charles J; Al-Khaffaf, Haytham; Woodhead, Peter M

    2014-01-01

    A surveillance duplex scan detected a stenosis within a left groin hemodialysis loop graft in a 57-year-old woman who was allergic to both iohexol and gadolinium contrast agents. This precluded the use of standard angioplasty treatment techniques. Intravascular ultrasound (IVUS) uses a catheter mounted with a miniaturized ultrasound probe to produce detailed cross-sectional vessel images. Clinically, it has been used in the assessment of coronary artery disease but has also supplemented standard angiography techniques in the assessment of peripheral vascular and hemodialysis access lesions. IVUS was utilized as the solitary imaging modality to identify the graft stenosis and guide the placement of a 6 mm diameter angioplasty balloon. Two areas of stenosis were successfully dilated and subsequent IVUS re-examination showed abolition of the stenosis. Twelve-month follow-up surveillance scan showed that the graft remained functional with good flow rates. In the setting of contrast allergy, IVUS may provide a valid and safe tool in the localization and treatment of peripheral vessel stenosis, including arteriovenous fistula angioplasty. To our knowledge this is the first reported use of IVUS for hemodialysis graft salvage adopting a completely 'contrast-free' technique. More studies are required to establish the true role of IVUS in the management of hemodialysis access angioplasty, but this successful case contributes valuable information to the literature on its clinical application.

  15. A random walk-based method for segmentation of intravascular ultrasound images

    Science.gov (United States)

    Yan, Jiayong; Liu, Hong; Cui, Yaoyao

    2014-04-01

    Intravascular ultrasound (IVUS) is an important imaging technique that is used to study vascular wall architecture for diagnosis and assessment of the vascular diseases. Segmentation of lumen and media-adventitia boundaries from IVUS images is a basic and necessary step for quantitative assessment of the vascular walls. Due to ultrasound speckles, artifacts and individual differences, automated segmentation of IVUS images represents a challenging task. In this paper, a random walk based method is proposed for fully automated segmentation of IVUS images. Robust and accurate determination of the seed points for different regions is the key to successful use of the random walk algorithm in segmentation of IVUS images and is the focus of our work. The presented method mainly comprises five steps: firstly, the seed points inside the lumen and outside the adventitia are roughly estimated with intensity information, respectively; secondly, the seed points outside the adventitia are refined, and those of the media are determined through the results of applying random walk to the IVUS image with the roughly estimated seed points; thirdly, the media-adventitia boundary is detected by using random walk with the seed points obtained in the second step and the image gradient; fourthly, the seed points for media and lumen are refined; finally, the lumen boundary is extracted by using random walk again with the seed points obtained in the fourth step and the image gradient. The tests of the proposed algorithm on the in vivo dataset demonstrate the effectiveness of the presented IVUS image segmentation approach.

  16. Angiographically borderline left main coronary artery lesions: correlation of transthoracic doppler echocardiography and intravascular ultrasound: a pilot study

    Directory of Open Access Journals (Sweden)

    Varga Albert

    2011-06-01

    Full Text Available Abstract Background the clinical decision making could be difficult in patients with borderline lesions (visually assessed stenosis severity of 30 to 50% of the left main coronary artery (LM. The aim of the study was to evaluate the relationship between transthoracic Doppler (TTDE peak diastolic flow velocity (PDV and intravascular ultrasound (IVUS measurements in the assessment of angiographically borderline LM lesions. Methods 27 patients (mean age 64 ± 8 years, 21 males with borderline LM stenosis referred for IVUS examination were included in the study. We performed standard IVUS with minimal lumen area (MLA and plaque burden (PB measurement and routine quantitative coronary angiography (QCA with diameter stenosis (%DS and area stenosis (%AS assessment in all. During TTDE, resting PDV was measured in the LM. Results interpretable Doppler signal could be obtained in 24 patients (88% feasibility; therefore these patients entered the final analysis. MLA was 7.1 ± 2.7 mm2. TTDE measured PDV correlated significantly with IVUS-derived MLA (r = -0.46, p 2 LM stenosis. Conclusion In angiographically borderline LM disease, resting PDV from transthoracic echocardiography is increased in presence of increased plaque burden by IVUS. TTDE evaluation might be a useful adjunct to other invasive and non-invasive methods in the assessment of borderline LM lesions. Further, large scale studies are needed to establish the exact cut-off value of PDV for routine clinical application.

  17. Introducing nuclei scatterer patterns into histology based intravascular ultrasound simulation framework

    Science.gov (United States)

    Kraft, Silvan; Karamalis, Athanasios; Sheet, Debdoot; Drecoll, Enken; Rummeny, Ernst J.; Navab, Nassir; Noël, Peter B.; Katouzian, Amin

    2013-03-01

    Medical ultrasonic grayscale images are formed from acoustic waves following their interactions with distributed scatterers within tissues media. For accurate simulation of acoustic wave propagation, a reliable model describing unknown parameters associated with tissues scatterers such as distribution, size and acoustic properties is essential. In this work, we introduce a novel approach defining ultrasonic scatterers by incorporating a distribution of cellular nuclei patterns in biological tissues to simulate ultrasonic response of atherosclerotic tissues in intravascular ultrasound (IVUS). For this reason, a virtual phantom is generated through manual labeling of different tissue types (fibrotic, lipidic and calcified) on histology sections. Acoustic properties of each tissue type are defined by assuming that the ultrasound signal is primarily backscattered by the nuclei of the organic cells within the intima and media of the vessel wall. This resulting virtual phantom is subsequently used to simulate ultrasonic wave propagation through the tissue medium computed using finite difference estimation. Subsequently B-mode images for a specific histological section are processed from the simulated radiofrequency (RF) data and compared with the original IVUS of the same tissue section. Real IVUS RF signals for these histological sections were obtained using a single-element mechanically rotating 40MHz transducer. Evaluation is performed by trained reviewers subjectively assessing both simulated and real B-mode IVUS images. Our simulation platform provides a high image quality with a very promising correlation to the original IVUS images. This will facilitate to better understand progression of such a chronic disease from micro-level and its integration into cardiovascular disease-specific models.

  18. Delineation of atherosclerotic plaque using subharmonic imaging filtering techniques and a commercial intravascular ultrasound system.

    Science.gov (United States)

    Sridharan, Anush; Eisenbrey, John R; Machado, Priscilla; deMuinck, Ebo D; Doyley, Marvin M; Forsberg, Flemming

    2013-01-01

    The ability to delineate atherosclerotic plaque from the surrounding tissue using custom-developed subharmonic imaging (SHI) digital filtering techniques was investigated in vivo using a commercially available system. Atherosclerosis was induced in the aorta of two Watanabe Heritable Hyperlipidemic rabbits following which injections of an ultrasound contrast agent (UCA) Definity (Lantheus Medical Imaging, N Billerica, Massachusetts) were administered. Imaging was performed using a Galaxy intravascular ultrasound (IVUS) scanner (Boston Scientific, Natick, Massachusetts) equipped with an Atlantis® SR Pro Imaging Catheter (Boston Scientific). Four preliminary band-pass filters were designed to isolate the subharmonic signal (from surrounding tissue) and applied to the radio-frequency (RF) data. Preliminary filter performances were compared in terms of vessel-tissue contrast-to-tissue ratio (CTR) and visual examination. Based on preliminary results, a subharmonic adaptive filter and a stopband (SB) filter were designed and applied to the RF data. Images were classified as fundamental, SHI, and SB. Four readers performed qualitative analysis of 168 randomly selected images (across all three imaging modes). The images were scored for overall image quality, image noise, plaque visualization, and vessel lumen visualization. A Wilcoxon signed-rank test was used to compare the scores followed by intraclass correlation (ICC) evaluation. Quantitative analysis was performed by calculating the CTRs for the vessel-to-plaque and vessel-to-tissue (compared using a paired student's t test). Qualitative analysis showed SHI and SB to have significantly less image noise relative to the fundamental mode (p < 0.001). Fundamental mode scored significantly higher than SHI and SB for the remaining three categories. ICC showed mixed results among reader evaluation for delineation of plaque. However, quantitatively, SHI produced the best vessel-plaque CTR.

  19. Percutaneous transradial coronary Palmaz-Schatz stent implantation, guided by intravascular ultrasound.

    Science.gov (United States)

    Kiemeneij, F; Laarman, G J; Slagboom, T

    1995-02-01

    Intravascular ultrasound (IVUS) allows accurate assessment of stent deployment, its use being confined to the use of 8 French (F) guiding catheters. We evaluated the feasibility of combining transradial artery Palmaz-Schatz stent implantation through 6F guiding catheters with IVUS for assessment of stent diameter after delivery at moderate inflation pressures (10-12 atmospheres [atm]) with compliant balloons and after high pressure dilatations with balloons of intermediate compliance. In 8 consecutive patients, 12 stents were delivered with Scimed Express balloon catheters at 10-12 atm followed by IVUS (EndoSonics CathScanner; Visions FX 3.5F 20 MHz transducer). An ultrasound study was repeated after high pressure dilatations (16-20 atm) with Schneider Magical Speedy balloon catheters. The balloon diameters were derived from manufacturer provided specifications. In all patients the transducer could easily be advanced through the guiding catheters. Reference diameter of the stented segment was 3.7 +/- 0.5 mm (2.7-4.5) and the diameter of Scimed Express balloons during inflation was 4.0 +/- 0.3 mm (3.6-4.7). Stent diameter was 3.0 +/- 0.1 mm (2.8-3.2) (P < 0.001 compared to the reference and the balloon diameter). The diameter of the Schneider Magical Speedy balloons at secondary dilatations with 16 +/- 3 atm (14-20) was 4.1 +/- 0.4 mm (3.3-4.5) (P = 0.50 compared to the initial balloon diameter). Final stent diameter was 3.3 +/- 0.4 mm (2.9-4.1) (P = 0.02 compared to the initial stent diameter). All stents were symmetrically deployed and well apposed. No damage to vessel or stents was detected after passage of the transducer.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. The virtual histology intravascular ultrasound appearance of newly placed drug-eluting stents.

    Science.gov (United States)

    Kim, Sang-Wook; Mintz, Gary S; Hong, Young-Joon; Pakala, Rajbabu; Park, Kyung-Sook; Pichard, Augusto D; Satler, Lowell F; Kent, Kenneth M; Suddath, William O; Waksman, Ron; Weissman, Neil J

    2008-11-01

    Intravascular ultrasound (IVUS) is used before and after intervention and at follow-up to assess the quality of the acute result as well as the long-term effects of stent implantation. Virtual histology (VH) IVUS classifies tissue into fibrous and fibrofatty plaque, dense calcium, and necrotic core. Although most interventional procedures include stent implantation, VH IVUS classification of stent metal has not been validated. In this study, the VH IVUS appearance of acutely implanted stents was assessed in 27 patients (30 lesions). Most stent struts (80%) appeared white (misclassified as "calcium") surrounded by red (misclassified as "necrotic core"); 2% appeared just white, and 17% were not detectable (compared with grayscale IVUS because of the software-imposed gray medial stripe). The rate of "white surrounded by red" was similar over the lengths of the stents; however, undetectable struts were mostly at the distal edges (31%). Quantitatively, including the struts within the regions of interest increased the amount of "calcium" from 0.23 +/- 0.35 to 1.07 +/- 0.66 mm(2) (p stents have an appearance that can be misclassified by VH IVUS as "calcium with or without necrotic core." It is important not to overinterpret VH IVUS studies of chronically implanted stents when this appearance is observed at follow-up. A separate classification for stent struts is necessary to avoid these misconceptions and misclassifications.

  1. Fast retrieval of calcification from sequential intravascular ultrasound gray-scale images.

    Science.gov (United States)

    Zheng, Sun; Bing-Ru, Liu

    2016-08-12

    Intravascular ultrasound (IVUS)-based tissue characterization is invaluable for the computer-aided diagnosis and interventional treatment of cardiac vessel diseases. Although the analysis of raw backscattered signals allows more accurate plaque characterization than gray-scale images, its applications are limited due to its nature of electrocardiogram-gated acquisition. Images acquired by IVUS devices that do not allow the acquisition of raw signals cannot be characterized. To address these limitations, we developed a method for fast frame-by-frame retrieval and location of calcification according to the jump features of radial gray-level variation curves from sequential IVUS gray-scale images. The proposed method consists of three main steps: (1) radial gray-level variation curves are extracted from each filtered polar view, (2) sequential images are preliminarily queried according to the maximal slopes of radial gray-level variation curves, and finally, (3) key frames that include calcification are selected through checking the gray-level features of successive pixel columns in the preliminary results. Experimental results with clinically acquired in vivo data sets indicate key frames that include calcification can be retrieved with the advantages of simplicity, high efficiency, and accuracy. Recognition results correlate well with manual characterization results obtained by experienced physicians and through virtual histology.

  2. The potential value of intravascular ultrasound imaging in diagnosis of aortic intramural hematoma

    Institute of Scientific and Technical Information of China (English)

    Wei Hu; Francois Schiele; Nicolas Meneveau; Marie-France Seronde; Pierre Legalery; Jean-Francois Bonneville; Sidney Chocron; Jean-Pierre Bassand

    2011-01-01

    Objective To evaluate the potential value of intravascular ultrasound (IVUS) imaging in the diagnosis of aortic intramural hematoma (AIH).Methods From September 2002 to May 2005,a consecutive series of 15 patients with suspected aortic dissection (AD) underwent both IVUS imaging and spiral computed tomography (CT).Six patients diagnosed as acute type B AIH by CT or IVUS composed the present study group.Results The study group consisted of five males and one female with mean age of 66 years old.All of them had chest or back pain.In one patient,CT omitted a localized AIH and an associated penetrating atherosclerotic ulcer (PAU),which were detected by IVUS.In another patient,CT mistaken a partly thrombosed false lumen as an AIH,whereas IVUS detected a subtle intimal tear and slow moving blood in the false lumen.In the four rest patients,both CT and IVUS made the diagnosis of AIH,however,IVUS detected three PAUs in three of them,only one of them was also detected by CT,and two of them escaped initial CT and were confirmed by follow up CT or magnetic resonance imaging.Conclusions IVUS imaging is a safe examination and has high accuracy in the diagnosis of AIH,particularly for diagnosing localized AIH,distinguishing AIH with thrombosed classic AD and detecting accompanied small PAUs.

  3. The potential value of intravascular ultrasound imaging in diagnosis of aortic intramural hematoma

    Science.gov (United States)

    Hu, Wei; Schiele, Francois; Meneveau, Nicolas; Seronde, Marie-France; Legalery, Pierre; Bonneville, Jean-Francois; Chocron, Sidney; Bassand, Jean-Pierre

    2011-01-01

    Objective To evaluate the potential value of intravascular ultrasound (IVUS) imaging in the diagnosis of aortic intramural hematoma (AIH). Methods From September 2002 to May 2005, a consecutive series of 15 patients with suspected aortic dissection (AD) underwent both IVUS imaging and spiral computed tomography (CT). Six patients diagnosed as acute type B AIH by CT or IVUS composed the present study group. Results The study group consisted of five males and one female with mean age of 66 years old. All of them had chest or back pain. In one patient, CT omitted a localized AIH and an associated penetrating atherosclerotic ulcer (PAU), which were detected by IVUS. In another patient, CT mistaken a partly thrombosed false lumen as an AIH, whereas IVUS detected a subtle intimal tear and slow moving blood in the false lumen. In the four rest patients, both CT and IVUS made the diagnosis of AIH, however, IVUS detected three PAUs in three of them, only one of them was also detected by CT, and two of them escaped initial CT and were confirmed by follow up CT or magnetic resonance imaging. Conclusions IVUS imaging is a safe examination and has high accuracy in the diagnosis of AIH, particularly for diagnosing localized AIH, distinguishing AIH with thrombosed classic AD and detecting accompanied small PAUs. PMID:22783309

  4. The Imaging Modulography Technique Revisited for High-Definition Intravascular Ultrasound: Theoretical Framework.

    Science.gov (United States)

    Tacheau, Antoine; Le Floc'h, Simon; Finet, Gérard; Doyley, Marvin M; Pettigrew, Roderic I; Cloutier, Guy; Ohayon, Jacques

    2016-03-01

    Mechanical characterization of atherosclerotic lesions remains an essential step for the detection of vulnerable plaques (VPs). Recently, an intravascular ultrasound (IVUS) elasticity reconstruction method (iMOD) has been tested in vivo by our group. The major limitation of iMOD is the need to estimate the strain field in the entire VP despite attenuated depth penetration signals when using high-definition (HD) IVUS systems. Therefore, an extended iMOD approach (E-iMOD) was designed and applied to coronary lesions of patients imaged in vivo with IVUS. The E-iMOD method (i) quantified necrotic core areas with a mean absolute relative error of 3.5 ± 3.5% and (ii) identified Young's moduli of the necrotic cores and fibrous regions with mean values of 5.7 ± 0.8 kPa and 794.5 ± 22.0 kPa instead of 5 kPa and 800 kPa, respectively. This study demonstrates the potential of the improved HD-IVUS modulography technique E-iMOD to characterize coronary VPs.

  5. Relation between baseline plaque features and subsequent coronary artery remodeling determined by optical coherence tomography and intravascular ultrasound.

    Science.gov (United States)

    Xie, Zulong; Dong, Nana; Sun, Rong; Liu, Xinxin; Gu, Xia; Sun, Yong; Du, Hongwei; Dai, Jiannan; Liu, Youbin; Hou, Jingbo; Tian, Jinwei; Yu, Bo

    2017-01-17

    Atherosclerosis often leads to myocardial infarction and stroke. We examined the influence of baseline plaque characteristics on subsequent vascular remodeling in response to changes in plaque size. Using optical coherence tomography (OCT) and intravascular ultrasound (IVUS), we examined 213 plaques from 138 patients with acute coronary syndrome at baseline and repeated IVUS at the 12-month follow-up. The change in external elastic membrane (EEM) area for each 1 mm2 change in plaque area (i.e., the slope of the regression line) was calculated as a measure of vascular remodeling capacity. In plaques with static positive remodeling, the slope was smaller than in plaques without static positive remodeling. In addition, the slope of the regression line for lesions with a large plaque burden was much smaller than that for lesions with a small plaque burden. Multivariate linear regression analysis showed that diabetes, calcification and static positive remodeling were inversely and independently associated with the level of change in EEM area/change in plaque area. Lesions with a large plaque burden, calcifications or static positive remodeling had less remodeling capacity, and calcification and static positive remodeling were independent predictors of reduced subsequent remodeling. Therefore, calcifications and static positive remodeling could be used as morphological biomarkers to predict decreased subsequent arterial remodeling.

  6. Clinical feasibility of 3D automated coronary atherosclerotic plaque quantification algorithm on coronary computed tomography angiography: Comparison with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung-Bok [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Myongji Hospital, Division of Cardiology, Cardiovascular Center, Goyang (Korea, Republic of); Lee, Byoung Kwon [Yonsei University College of Medicine, Division of Cardiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Shin, Sanghoon [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); National Health Insurance Corporation Ilsan Hospital, Division of Cardiology, Goyang (Korea, Republic of); Heo, Ran; Chang, Hyuk-Jae; Chung, Namsik [Yonsei University Health System, Yonsei-Cedar Sinai Integrative Cardiovascular Imaging Research Center, Seoul (Korea, Republic of); Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of); Arsanjani, Reza [Cedars-Sinai Medical Center, Departments of Imaging and Medicine, Cedars-Sinai Heart Institute, Los Angeles, CA (United States); Kitslaar, Pieter H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical Imaging Systems B.V., Leiden (Netherlands); Broersen, Alexander; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Ahn, Sung Gyun [Yonsei University Wonju Severance Christian Hospital, Division of Cardiology, Wonju (Korea, Republic of); Min, James K. [New York-Presbyterian Hospital, Institute for Cardiovascular Imaging, Weill-Cornell Medical College, New York, NY (United States); Hong, Myeong-Ki; Jang, Yangsoo [Yonsei University Health System, Division of Cardiology, Severance Cardiovascular Hospital, Seoul (Korea, Republic of)

    2015-10-15

    To evaluate the diagnostic performance of automated coronary atherosclerotic plaque quantification (QCT) by different users (expert/non-expert/automatic). One hundred fifty coronary artery segments from 142 patients who underwent coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS) were analyzed. Minimal lumen area (MLA), maximal lumen area stenosis percentage (%AS), mean plaque burden percentage (%PB), and plaque volume were measured semi-automatically by expert, non-expert, and fully automatic QCT analyses, and then compared to IVUS. Between IVUS and expert QCT analysis, the correlation coefficients (r) for the MLA, %AS, %PB, and plaque volume were excellent: 0.89 (p < 0.001), 0.84 (p < 0.001), 0.91 (p < 0.001), and 0.94 (p < 0.001), respectively. There were no significant differences in the mean parameters (all p values >0.05) except %AS (p = 0.01). The automatic QCT analysis showed comparable performance to non-expert QCT analysis, showing correlation coefficients (r) of the MLA (0.80 vs. 0.82), %AS (0.82 vs. 0.80), %PB (0.84 vs. 0.73), and plaque volume (0.84 vs. 0.79) when they were compared to IVUS, respectively. Fully automatic QCT analysis showed clinical utility compared with IVUS, as well as a compelling performance when compared with semiautomatic analyses. (orig.)

  7. Impact of Indoxyl Sulfate, a Uremic Toxin, on Non-Culprit Coronary Plaque Composition Assessed on Integrated Backscatter Intravascular Ultrasound.

    Science.gov (United States)

    Yamazaki, Hiromu; Yamaguchi, Koji; Soeki, Takeshi; Wakatsuki, Tetsuzo; Niki, Toshiyuki; Taketani, Yoshio; Kitaoka, Atsunori; Kusunose, Kenya; Ise, Takayuki; Tobiume, Takeshi; Yagi, Shusuke; Iwase, Takashi; Yamada, Hirotsugu; Sata, Masataka

    2015-01-01

    Uremic toxin has emerged as an important determinant of cardiovascular risk. The aim of this study was to examine the relationship between serum uremic toxin and coronary plaque composition on integrated backscatter intravascular ultrasound (IB-IVUS). IB-IVUS was performed in 47 patients with planned treatment for angina pectoris. Non-culprit intermediate plaque analyzed in this study had to be >5 mm apart from the intervention site. 3-D IB-IVUS analysis was performed to determine percent lipid volume (LV) and fibrous volume (FV). We also measured serum uremic toxins (indoxyl sulfate [IS], asymmetric dimethylarginine [ADMA], and p-cresol [PC]). Glomerular filtration rate correlated with IS (r=-0.329, P=0.04), but did not correlate with ADMA or PC. Percent LV correlated with IS (r=0.365, P=0.02), but did not correlate with ADMA or PC. Percent FV also correlated with IS (r=-0.356, P=0.03), but did not correlate with ADMA or PC. On multivariate regression, only IS was associated with percent LV (r=0.359, P=0.04) and percent FV (r=-0.305, P=0.04) independently of potentially confounding coronary risk factors. Among the uremic toxins, serum IS might be a novel useful biomarker to detect and monitor lipid-rich coronary plaque on IB imaging.

  8. Continued improvement of clinical outcome and cost effectiveness following intravascular ultrasound guided PCI: insights from a prospective, randomised study

    Science.gov (United States)

    Gaster, A L; Slothuus Skjoldborg, U; Larsen, J; Korsholm, L; von Birgelen, C; Jensen, S; Thayssen, P; Pedersen, K E; Haghfelt, T H

    2003-01-01

    Objective: To investigate in a prospective randomised study both long term clinical effects and cost effectiveness of percutaneous coronary interventions (PCI) with or without intravascular ultrasound (IVUS) guidance. Methods: 108 male patients with stable angina referred for PCI of a significant coronary lesion were randomly assigned to IVUS guided PCI or conventional PCI. Individual accumulated costs of the entire follow up period were calculated and compared in the randomisation groups. Effectiveness of treatment was measured by freedom from major adverse cardiac events. Results: Cost effectiveness of IVUS guided PCI that was noted at six months was maintained and even accentuated at long term follow up (median 2.5 years). The cumulated cost level was found to be lower for the IVUS guided group, with a cumulated cost of &163 672 in the IVUS guided group versus &313 706 in the coronary angiography group (p = 0.01). Throughout the study, mean cost per day was lower in the IVUS guided PCI group (&2.7 v &5.2; p = 0.01). In the IVUS group, 78% were free from major adverse cardiac events versus 59% in the coronary angiography group (p = 0.04) with an odds ratio of 2.5 in favour of IVUS guidance. Conclusion: IVUS guidance results in continued improvement of long term clinical outcome and cost effectiveness. The results of this study suggest that IVUS guidance may be used more liberally in PCI. PMID:12923023

  9. Characterization of coronary plaques with combined use of intravascular ultrasound, virtual histology and optical coherence tomography

    Directory of Open Access Journals (Sweden)

    José Calabuig

    2010-09-01

    Full Text Available According to post-mortem studies, luminal thrombosis occurs from plaque rupture, erosion and calcified nodules. In vivo studies have found thin cap fibroatheroma (TCFA as the main vulnerable lesion, prone to rupture. Few data about other post-mortem lesions have been reported in vivo. Our main objective is to characterize in vivo the coronary plaques with intravascular ultrasound-virtual histology (IVUS-VH and optical coherence tomography (OCT, in order to detect not only thin cap fibroatheroma (TCFA, but also other possible vulnerable lesions. The secondary objective is to correlate these findings with clinical and analytical data. Twenty-five patients (18 stable submitted to coronary angiography were included in this pilot study. After angiography, the three vessels were studied (when possible with IVUS-VH and OCT. Plaque characteristics were correlated with clinical and analytical data. Forty-six lesions were analyzed. IVUS-VH detected significant necrotic core in 15 (3 were definite TCFA. OCT detected TCFA in 10 lesions, erosion in 6, thrombus in 5 and calcified nodule in 8. Possible vulnerable lesion was found in 61% of stable and 57% of unstable patients. Erosions and calcified nodules were only found in stable patients. Those with significant necrotic core had higher body mass index (P=0.016, higher levels of hs-CRP (P=0.019 and triglycerides (P=0.040. The higher the levels of hs-CRP, the larger the size of the necrotic core (r=0.69, P=0.003. Lesions with characteristics of vulnerability were detected by IVUS-VH and OCT in more than 50% of stable and unstable coronary patients. A significant necrotic core was mainly correlated with

  10. Effect of probucol on vascular remodeling due to atherosclerosis in rabbits: an intravascular ultrasound study

    Institute of Scientific and Technical Information of China (English)

    LI Ting-ting; XIE Yi; GUO Yuan; TIAN Hong-bo; ZHANG Jian-ning; PENG Jie; ZHANG Yun

    2011-01-01

    Background Probucol is known to reduce the development of atherosclerotic lesions, but its impact on vascular remodeling associated with de novo atherosclerosis is incompletely understood. We therefore examined the effect of probucol on vascular remodeling in a rabbit model of established atherosclerosis.Methods Aortic atherosclerosis was induced by a combination of endothelial injury and 10 weeks' atherogenic diet. Animals were then randomized to receive the foregoing diet without or with 1% (wt/wt) probucol for 16 weeks. At the end of week 26, in vivo intravascular ultrasound, pathological, immunohistochemical and gene expression studies were performed.Results Probucol significantly decreased vessel cross-sectional area, plaque area and plaque burden without effect on lumen area. More negative remodeling and less positive remodeling occurred in the abdominal aortas of probucol group than the control group (56% vs. 21%, 18% vs. 54%, respectively, both P<0.01). In addition, the probucol group showed a smaller mean remodeling index relative to the control group (0.93 ± 0.13 vs. 1.05 ±0.16, P<0.01). Furthermore, probucol treatment decreased macrophage infiltration, inhibited apoptosis of cells within plaques, and reduced the production of matrix metalloproteinases-2, -9, cathepsin K and cathepsin S (all P<0.01).Conclusions These findings suggest that probucol may attenuate the enlargement of atherosclerotic vessel walls and be associated with a negative remodeling pattern without affecting the lumen size. This effect may involve inhibition of extracellular matrix degradation and prevention of apoptosis in atherosclerotic plaques.

  11. Angioplasty Guided by Intravascular Ultrasound: Meta-Analysis of Randomized Clinical Trials

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, José Albuquerque Neto de, E-mail: jafneto@cardiol.br; Nogueira, Iara Antonia Lustosa [Universidade Federal do Maranhão, São Luiz, MA (Brazil); Figueiro, Mabel Fernandes; Buehler, Anna Maria; Berwanger, Otavio [Instituto de Ensino e Pesquisa do Hospital do Coração, São Paulo, SP (Brazil)

    2013-08-15

    The impact of intravascular ultrasound (IVUS) use on stenting has shown inconclusive results. Systematic review and meta-analysis of the impact of IVUS on stenting regarding the clinical and angiographic evolution. A search was performed in Medline/Pubmed, CENTRAL, Embase, Lilacs, Scopus and Web of Science databases. It included randomized clinical trials (RCTs) that evaluated the implantation of stents guided by IVUS, compared with those using angiography alone (ANGIO). The minimum follow-up duration was six months and the following outcomes were assessed: thrombosis, mortality, myocardial infarction, percutaneous and surgical revascularization, major adverse cardiovascular events (MACE) and restenosis. The binary outcomes were presented considering the number of events in each group; the estimates were generated by a random effects model, considering Mantel-Haenszel statistics as weighting agent and magnitude of effect for the relative risk (RR) with its respective 95% confidence interval (95%CI). Higgins I{sup 2} test was used to quantify the consistency between the results of each study. A total of 2,689 articles were evaluated, including 8 RCTs. There was a 27% reduction in angiographic restenosis (RR: 0.73, 95% CI: 0.54-0.97, I{sup 2} = 51%) and statistically significant reduction in the rates of percutaneous revascularization and overall (RR: 0.88; 95% CI: 0.51 to 1.53, I{sup 2} = 61%, RR: 0.73, 95% CI: 0.54 to 0.99, I{sup 2} = 55%), with no statistical difference in surgical revascularization (RR: 0.95, 95% CI: 0.52-1.74, I{sup 2} = 0%) in favor of IVUS vs. ANGIO. There were no differences regarding the other outcomes in the comparison between the two strategies. Angioplasty with stenting guided by IVUS decreases the rates of restenosis and revascularization, with no impact on MACE, acute myocardial infarction, mortality or thrombosis outcomes.

  12. Compensatory enlargement in transplant coronary artery disease: an intravascular ultrasound study

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Background It is unclear to what extent the "Glagov phenomenon" occurs in transplant coronary artery disease (TCAD). The objective of this study was to evaluate the relationship between intimal hyperplasia and compensatory enlargement in TCAD. Methods Intravascular ultrasound imaging was performed on 190 cardiac transplant recipients at (1.4±0.6) months and again (12.1±0.7) months after cardiac transplantation. Studies 1 year apart were matched at 625 sites. There were 345 coronary artery sites that had an increase in intimal area >10% from baseline to one year, and this comprised the data set of the present study. Results At the first year, 91% of coronary artery sites with intimal growth had a total cross-sectional area stenosis ≤40%, but 38% of the sites showed a decrease of >10% in lumen area. Receiver operating characteristic curve demonstrated that the change in cross-sectional area stenosis cut-off level at year 1 was 8% with a sensitivity of 75% and a specificity of 82% in predicting lumen loss. At a total cross-sectional area stenosis of 20%, sensitivity was 65% with a specificity of 81% in predicting lumen loss. Conclusions In TCAD, vessel enlargement as a compensatory mechanism for plaque growth is generally inadequate. Instead of continued vessel expansion, luminal narrowing develops when there is more than 8% cross-sectional area filled with intimal hyperplasia. In distinction to native coronary artery atherosclerotic disease, the transition point in transplant vasculopathy where the lumen is diminished by increasing intimal growth, occurs at a lower threshold, 20% vs 40% of vessel cross-sectional area.

  13. Myocardial bridging detection by non-invasive multislice spiral computed tomography: comparison with intravascular ultrasound

    Institute of Scientific and Technical Information of China (English)

    WANG Ming-hui; ZHANG Feng; Raimund Erbel; GE Jun-bo; SUN Ai-jun; QIAN Ju-ying; LING Qing-zhi; ZENG Meng-su; GE Lei; WANG Ke-qiang; FAN Bing; YAN Wei

    2008-01-01

    Background Invasive intravascular ultrasound (IVUS) is current dlagnostic Standard for myocardial bridging (MB).Non-invasive multislice computerized tomography coronary angiography (MSCT) technique has provided a good anatomical view of the tunnel arten/ now.Methods A total of 51 consecutive patients with atypical or typical angina scheduled for IVUS were enrolled in this study and MSCT was performed 7 days before IVUS. Coronary imaging was quantified using IVUS and MSCT. Four main vessels (left main artery (LMA), left anterior descending (LAD), left circumflex (LCX), right coronary artery (RCA)) were examined.Results Forty-one out of 51 (80%) patients received metaprolol (25 mg) before the MSCT scan and 25 of them were current beta-blocker users. The mean heart rate was (64±3) beats per minute. A total of 51 patients underwent IVUS examination (30 with MB and 21 without MB) were chosen for this study. Twenty-eight out of 30 MB cases were correctly diagnosed by MSCT and 2 patients with MB were not detected. Comparison with IVUS, the sensitivity of detection by MSCT was 93%, specificity was 100%. The lumen diameter of the tunnel artery derived from MSCT and IVUS significantly decreased from (2.9±0.3) mm to (2.4±0.4) mm (P<0.001) and from (3.3±0.3) mm to (2.6±0.5) mm (P<0.001),respectively. Minimal and maximal diameters of MB derived from MSCT were significantly smaller than those from IVUS ((2.4±0.4) mm vs (2.6±0.5) mm, P<0.05 and (2.9±0.3) mm vs (3.3±0.3) mm, P<0.05), respectively.Conclusions MSCT offers a reliable non-invasive method for MB in LAD and atherosclerosis diagnosis with diagnostic accuracy comparable with invasive IVUS.

  14. Towards a Reduced-Wire Interface for CMUT-Based Intravascular Ultrasound Imaging Systems.

    Science.gov (United States)

    Lim, Jaemyung; Tekes, Coskun; Degertekin, F Levent; Ghovanloo, Maysam

    2017-04-01

    Having intravascular ultrasound (IVUS) imaging capability on guide wires used in cardiovascular interventions may eliminate the need for separate IVUS catheters and expand the use of IVUS in a larger portion of the vasculature. High frequency capacitive micro machined ultrasonic transducer (CMUT) arrays should be integrated with interface electronics and placed on the guide wire for this purpose. Besides small size, this system-on-a-chip (SoC) front-end should connect to the back-end imaging system with a minimum number of wires to preserve the critical mechanical properties of the guide wire. We present a 40 MHz CMUT array interface SoC, which will eventually use only two wires for power delivery and transmits image data using a combination of analog-to-time conversion (ATC) and an impulse radio ultra-wideband (IR-UWB) wireless link. The proof-of-concept prototype ASIC consumes only 52.8 mW and occupies 4.07 [Formula: see text] in a 0.35- [Formula: see text] standard CMOS process. A rectifier and regulator power the rest of the SoC at 3.3 V from a 10 MHz power carrier that is supplied through a 2.4 m micro-coax cable with an overall efficiency of 49.1%. Echo signals from an 8-element CMUT array are amplified by a transimpedance amplifier (TIA) array and down-converted to baseband by quadrature sampling using a 40 MHz clock, derived from the power carrier. The ATC generates pulse-width-modulated (PWM) samples at 2 × 10 MS/s with 6 bit resolution, while the entire system achieved 5.1 ENOB. Preliminary images from the prototype system are presented, and alternative data transmission and possible future directions towards practical implementation are discussed.

  15. Coronary venous lead implantation after an evaluation by virtual histology intravascular ultrasound and stenting of a stenosis.

    Science.gov (United States)

    Yamasaki, Hiro; Tada, Hiroshi; Arimoto, Takanori; Sekiguchi, Yukio; Sato, Akira; Aonuma, Kazutaka

    2013-02-01

    We describe a patient who developed coronary vein (CV) stenosis shortly (virtual histological intravascular ultrasound analysis was useful for characterizing the plaque component of the stenotic lesion and formulating the strategy. A summarized review of the CV angioplasty for LV lead implantations disclosed that CV stenosis was often found in patients who had a previous history of cardiac surgery or an LV lead implantation and that a stent implantation was required to deploy the LV lead in the targeted CV in some (9.3%) patients.

  16. [Comparison of Atherosclerotic Lesions in Patients With Acute Myocardial Infarction and Stable Angina Pectoris Using Intravascular Ultrasound].

    Science.gov (United States)

    Tagieva, N R; Shakhnovich, R M; Mironov, V M; Yezhov, M V; Matchin, Yu G; Mitroshkin, M G; Safarova, M S; Shitov, V N; Ruda, M Ya

    2015-07-01

    to compare noninfarct-related lesions in patients with acute myocardial infarction (MI) with culprit and non-culprit lesions in patients with stable angina pectoris (SAP) using intravascular ultrasound virtual histology (VH-IVUS). Overall 70 patients were enrolled: 38 with ST elevation (STE) MI and 32 with stable angina pectoris (SAP). All patients underwent three-vessel coronary angiography and gray-scale and VH-IVUS after percutaneous coronary intervention (PCI) of infarct-related lesion in STEMI or culprit lesion in SAP.

  17. 80-MHz intravascular ultrasound transducer using PMN-PT free-standing film.

    Science.gov (United States)

    Li, Xiang; Wu, Wei; Chung, Youngsoo; Shih, Wan Y; Shih, Wei-Heng; Zhou, Qifa; Shung, K Kirk

    2011-11-01

    [Pb(Mg(1/3)Nb(2/3))O(3)](0.63)[PbTiO(3)](0.37) (PMN-PT) free-standing film of comparable piezoelectric properties to bulk material with thickness of 30 μm has been fabricated using a modified precursor coating approach. At 1 kHz, the dielectric permittivity and loss were 4364 and 0.033, respectively. The remnant polarization and coercive field were 28 μC/cm(2) and 18.43 kV/cm. The electromechanical coupling coefficient k(t) was measured to be 0.55, which was close to that of bulk PMN-PT single-crystal material. Based on this film, high-frequency (82 MHz) miniature ultrasonic transducers were fabricated with 65% bandwidth and 23 dB insertion loss. Axial and lateral resolutions were determined to be as high as 35 and 176 μm. In vitro intravascular imaging on healthy rabbit aorta was performed using the thin film transducers. In comparison with a 35-MHz IVUS transducer, the 80-MHz transducer showed superior resolution and contrast with satisfactory penetration depth. The imaging results suggest that PMN-PT free-standing thin film technology is a feasible and efficient way to fabricate very-high-frequency ultrasonic transducers.

  18. ECG-Gated Three-dimensional Intravascular Ultrasound : Feasibility and Reproducibility of the Automated Analysis of Coronary Lumen and Atherosclerotic Plaque Dimensions in Humans

    NARCIS (Netherlands)

    C. von Birgelen (Clemens); E.A. de Vrey (Evelyn); G.S. Mintz (Gary); A. Nicosia; N. Bruining (Nico); W. Li (Wenguang); P.W.J.C. Serruys (Patrick); P.J. de Feyter (Pim); J.R.T.C. Roelandt (Jos); C.J. Slager (Cornelis)

    1997-01-01

    textabstractBackground Automated systems for the quantitative analysis of three-dimensional (3D) sets of intravascular ultrasound (IVUS) images have been developed to reduce the time required to perform volumetric analyses; however, 3D image reconstruction by these nongated systems is frequently

  19. The Impact of the Acute Results on the Long - Term Outcome after the Treatment of In- stent Restenosis: A Serial Intravascular Ultrasound Study

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Stenting reduces acute complications and restenosis compared to balloon angioplasty and other devices. However, in- stent restenosis (ISR) is an important clinical problem. The current serial intravascular ultrasound (IVUS)analysis was undertaken to determine whether the acute results obtained during the treatment of ISR influence the long term results and whether this is true for patients treated with and without adjunct brachytherapy.

  20. Evaluating the intensity of the acoustic radiation force impulse (ARFI) in intravascular ultrasound (IVUS) imaging: Preliminary in vitro results.

    Science.gov (United States)

    Shih, Cho-Chiang; Lai, Ting-Yu; Huang, Chih-Chung

    2016-08-01

    The ability to measure the elastic properties of plaques and vessels is significant in clinical diagnosis, particularly for detecting a vulnerable plaque. A novel concept of combining intravascular ultrasound (IVUS) imaging and acoustic radiation force impulse (ARFI) imaging has recently been proposed. This method has potential in elastography for distinguishing between the stiffness of plaques and arterial vessel walls. However, the intensity of the acoustic radiation force requires calibration as a standard for the further development of an ARFI-IVUS imaging device that could be used in clinical applications. In this study, a dual-frequency transducer with 11MHz and 48MHz was used to measure the association between the biological tissue displacement and the applied acoustic radiation force. The output intensity of the acoustic radiation force generated by the pushing element ranged from 1.8 to 57.9mW/cm(2), as measured using a calibrated hydrophone. The results reveal that all of the acoustic intensities produced by the transducer in the experiments were within the limits specified by FDA regulations and could still displace the biological tissues. Furthermore, blood clots with different hematocrits, which have elastic properties similar to the lipid pool of plaques, with stiffness ranging from 0.5 to 1.9kPa could be displaced from 1 to 4μm, whereas the porcine arteries with stiffness ranging from 120 to 291kPa were displaced from 0.4 to 1.3μm when an acoustic intensity of 57.9mW/cm(2) was used. The in vitro ARFI images of the artery with a blood clot and artificial arteriosclerosis showed a clear distinction of the stiffness distributions of the vessel wall. All the results reveal that ARFI-IVUS imaging has the potential to distinguish the elastic properties of plaques and vessels. Moreover, the acoustic intensity used in ARFI imaging has been experimentally quantified. Although the size of this two-element transducer is unsuitable for IVUS imaging, the

  1. Quantitative Ultrasound Measurements at the Heel

    DEFF Research Database (Denmark)

    Daugschies, M.; Brixen, K.; Hermann, P.

    2015-01-01

    Calcaneal quantitative ultrasound can be used to predict osteoporotic fracture risk, but its ability to monitor therapy is unclear possibly because of its limited precision. We developed a quantitative ultrasound device (foot ultrasound scanner) that measures the speed of sound at the heel...... with the foot ultrasound scanner reduced precision errors by half (p quantitative ultrasound measurements is feasible. (E-mail: m.daugschies@rad.uni-kiel.de) (C) 2015 World Federation for Ultrasound in Medicine & Biology....

  2. Intravascular ultrasound as a novel tool for the diagnosis and targeted treatment of functional popliteal artery entrapment syndrome

    Directory of Open Access Journals (Sweden)

    Anna E. Boniakowski, MD

    2017-06-01

    Full Text Available Functional popliteal artery entrapment syndrome can be difficult to diagnose, as the imaging modalities presently employed are designed to detect anatomic entrapment. We describe a novel imaging technique to aid in diagnosis in this cohort. A 22-year-old cyclist presented with exercise-limiting claudication. Magnetic resonance angiography with provocative maneuvers was nondiagnostic. Digital subtraction angiography revealed long-segment occlusion of the popliteal artery with plantar flexion; however, the specific site of compression remained unclear. Intravascular ultrasound allowed specific localization of compression and further confirmed the diagnosis. Thus, we report this as an adjunctive imaging modality to definitively diagnose functional popliteal artery entrapment syndrome and to assist in operative planning.

  3. Head to head comparison of optical coherence tomography, intravascular ultrasound echogenicity and virtual histology for the detection of changes in polymeric struts over time

    DEFF Research Database (Denmark)

    Brugaletta, Salvatore; Gomez-Lara, Josep; Bruining, Nico

    2012-01-01

    To analyse and to compare the changes in the various optical coherence tomography (OCT), echogenicity and intravascular ultrasound virtual histology (VH) of the everolimus-eluting bioresorbable scaffold (ABSORB) degradation parameters during the first 12 months after ABSORB implantation. In the A......To analyse and to compare the changes in the various optical coherence tomography (OCT), echogenicity and intravascular ultrasound virtual histology (VH) of the everolimus-eluting bioresorbable scaffold (ABSORB) degradation parameters during the first 12 months after ABSORB implantation....... In the ABSORB study, changes in the appearance of the ABSORB scaffold were monitored over time using various intracoronary imaging modalities. The scaffold struts exhibited a progressive change in their black core area by OCT, in their ultrasound derived grey level intensity quantified by echogenicity...

  4. Mode of deployment of coronary Palmaz-Schatz stents after implantation with the stent delivery system: an intravascular ultrasound study.

    Science.gov (United States)

    Kiemeneij, F; Laarman, G; Slagboom, T

    1995-04-01

    The stent delivery system (SDS) is a sheath-covered Palmaz-Schatz stent mounted on a 3.0, 3.5, or 4.0 mm compliant polyethylene balloon catheter; the balloon resists maximal inflation pressures of 5.7, 6.2, or 6.0 atm, respectively. It is postulated that these pressures are too low to obtain optimal stent deployment. Because optimal stent deployment is a prerequisite for optimal short- and long-term outcome, we performed an intravascular ultrasound study to the mode of stent deployment after delivery with the SDS and after high-pressure dilatations with low-compliant, oversized balloon catheters. In 23 patients an intravascular ultrasound study (30 MHz, 4.3F transducer) was performed to the geometry of 29 stents immediately after delivery with the SDS and after successive high-pressure inflations with low-compliant balloons. After delivery with the SDS (3.3 +/- 0.4 mm), stent diameter was 3.0 +/- 0.4 mm. After high-pressure dilatations (12.4 +/- 1.4 atm) with low-compliant balloons (3.9 +/- 0.5 mm), stent diameter increased to 3.4 +/- 0.4 mm (p < 0.001). Only 8 (28%) stents were completely and symmetrically expanded to the corresponding reference diameter with good apposition after delivery with the SDS. Diameter of incomplete deployed stents (n = 16) was 2.8 +/- 0.3 mm. After high-pressure dilatations with low-compliant balloons (3.9 +/- 0.5 mm), diameter increased to 3.4 +/- 0.4 mm (p < 0.001). Now 20 (69%) stents (p = 0.004) became completely and symmetrically expanded to a diameter corresponding to the reference diameter. In conclusion, most stents are suboptimally deployed after delivery with the stent delivery system.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Discrepant findings of computed tomography quantification of minimal lumen area of coronary artery stenosis: Correlation with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuehua, E-mail: andrewradiologist@hotmail.com [Department of Radiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University, No. 600, Yishan Rd, Shanghai 200233 (China); Zhang, Jiayin, E-mail: andrewssmu@msn.com [Department of Radiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University, No. 600, Yishan Rd, Shanghai 200233 (China); Lu, Zhigang, E-mail: andrewradiologist@gmail.com [Department of Cardiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University (China); Pan, Jingwei, E-mail: andrewssmu@gmail.com [Department of Cardiology, Shanghai No. 6 People' s Hospital, School of Medicine, Shanghai Jiaotong University (China)

    2012-11-15

    Objectives: To study the diagnostic performance of computed tomography (CT) quantification of minimal lumen area (MLA) based on multiple factors (image quality, calcification and lesion locations), with reference to intravascular ultrasound (IVUS). Methods: Consecutive clinically ordered patients were prospectively enrolled in our study. CT quantification of MLA was manually measured on cross-sectional view and further compared with IVUS findings. A significant lesion was defined as {<=}6 mm{sup 2} MLA for the left main (LM) coronary artery and a {<=}4 mm{sup 2} MLA for other epicardial vessels. Results: Non-calcified lesions had good correlation between CT and IVUS (r = 0.96) and the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 85% (51/60), 93.94% (31/33), 96.23% (51/53) and 77.5% (31/40) respectively. Decreased correlation (r = 0.814) lower specificity (23.81% (5/21)) and positive predictive value (60.98% (25/41)) were observed in calcified subgroup. Artifact-absent lesions demonstrated excellent correlation (r = 0.967) and the sensitivity, specificity, PPV and NPV were 96% (48/50), 93.94% (31/33), 96% (48/50) and 93.94% (31/33) respectively. Impaired correlation (r = 0.584) was noted in artifact-present lesions and the sensitivity, specificity, PPV and NPV were 80% (28/35), 23.81% (5/21), 63.64% (28/44) and 41.67% (5/12) respectively. Excellent correlation between CT and IVUS was noted in proximal epicardial vessels (r = 0.908) and the sensitivity, specificity, PPV and NPV were 92.31% (36/39), 78.13% (25/32), 83.72% (36/43) and 89.29% (25/28) respectively. Middle right coronary artery lesions showed non-significant correlation (r = 0.54, p = 0.055). Conclusions: CT quantification of MLA can only be accurately achieved in non-calcified lesions with absence of artifact. Diagnostic performance is impaired in calcified lesions.

  6. Relationship between hs-CRP, proMMP-1, TIMP-1 and coronary plaque morphology: intravascular ultrasound study

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xing-wei; ZHOU Liang; YE Xian-hua; XU Jian; GE Jun-bo; YANG Jian-min; GE Lei; WANG Ning-fu; GAO Yan; LI Pei-zhang; PAN Hao; TONG Guo-xin

    2006-01-01

    Background Rupture of unstable plaque with subsequent thrombus formation is the common pathophysiological substrate of the acute coronary syndrome (ACS). It is of potential significance to explore the blood indexes predicting plaque characteristics. Little studies have focused on this field. Therefore we investigated the relationship between hypersensitive C-reactive protein (hs-CRP), pro-matrix metalloproteinase-1 (proMMP-1),tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) and coronary plaque morphology.Methods Intravascular ultrasound (IVUS) examination was done in 152 patients with confirmed coronary heart disease before percutaneous coronary intervention from February 2003 to July 2005. Plasma samples of arterial blood were collected prior to the procedure. The level of hs-CRP, proMMP-1 and TIMP-1 were respectively measured by enzyme-linked immunosorbent assay (ELISA).Results Unstable and ruptured plaque were found more frequently in patients with acute myocardial infarction and unstable angina. External elastic membrane cross-sectional area (EEM CSA), plaque area, lipid pool area and plaque burden were significantly larger in ruptured and unstable plaque group. Positive remolding, thinner frequent in ruptured and unstable plaque group. The levels of plasma hs-CRP, proMMP-1 and TIMP-1 were higher in ruptured plaque group. hs-CRP>8.94 mg/L was used to predict ruptured plaque with a ROC curve area of 0.76 [95% confidence interval (CI), 67.0%-85.8%], sensitivity of 71.8%, specificity of 77.0% and accuracy of 69.2% (P<0.01), similarly for proMMP-1>0.12 ng/ml with a ROC curve area of 0.69 [95% CI, 58.2%-80.2%], sensitivity of 69.2%, specificity of 75.2% and accuracy of 66.2% (P<0.01), and TIMP-1>83.45 ng/ml with a ROC curve area of 0.67 [95% CI, 56.2%-78.3%], sensitivity of 66.7%, specificity of 61.9% and accuracy of 66.2% (P<0.01).Conclusion The plaque characteristics correlate with the clinical presentation. The elevation of hs-CRP,proMMP-1 and

  7. Virtual histology-intravascular ultrasound assessment of lesion coverage after angiographically-guided stent implantation in patients with ST Elevation myocardial infarction undergoing primary percutaneous coronary intervention.

    Science.gov (United States)

    Legutko, Jacek; Jakala, Jacek; Mintz, Gary S; Wizimirski, Marcin; Rzeszutko, Lukasz; Partyka, Lukasz; Mrevlje, Blaz; Richter, Angela; Margolis, Pauliina; Kaluza, Grzegorz L; Dudek, Dariusz

    2012-05-15

    An occlusion or severe stenosis (angiographic culprit lesion) of the infarct-related artery is frequently located at the site of the maximum thrombus burden, whereas the origin of the plaque rupture (the true culprit) can be situated proximal or distal to it. The aim of this study was to examine stent coverage of true culprit lesions in 20 patients who underwent primary percutaneous coronary intervention and had Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow restored in the infarct-related artery by angiographically guided direct stenting. Images of lesions were obtained using virtual histology-intravascular ultrasound before and after intervention (blinded to the operator). Plaque rupture sites were identified by intravascular ultrasound in 12 lesions (60%), 11 proximal and 1 distal to the minimum luminal area (MLA). Maximum necrotic core sites were found proximal to the MLA in 16 lesions, at the MLA in 3 lesions, and distal to the MLA in 1 lesion. Plaque rupture sites were fully covered by stents in 11 lesions. Virtual histology-intravascular ultrasound-derived thin-cap fibroatheroma longitudinal geographic misses were found in 10 lesions, 7 in the proximal reference segment and in 3 patients in the proximal and distal reference segments. In conclusion, in about 50% of patients who undergo primary percutaneous coronary intervention for ST-segment elevation myocardial infarction with optimal angiographic results, the stent does not fully cover the maximum necrotic core site related to the culprit lesion.

  8. Antiatherosclerotic effects of long-term maximally intensive statin therapy after acute coronary syndrome: insights from Study of Coronary Atheroma by Intravascular Ultrasound: Effect of Rosuvastatin Versus Atorvastatin.

    Science.gov (United States)

    Puri, Rishi; Nissen, Steven E; Shao, Mingyuan; Ballantyne, Christie M; Barter, Philip J; Chapman, M John; Erbel, Raimund; Libby, Peter; Raichlen, Joel S; Uno, Kiyoko; Kataoka, Yu; Nicholls, Stephen J

    2014-11-01

    Patients with acute coronary syndromes (ACS) display diffuse coronary atheroma instability and heightened risk of early and late recurrent coronary events. We compared the long-term antiatherosclerotic efficacy of high-intensity statins in patients with ACS when compared with stable disease. Study of Coronary Atheroma by Intravascular Ultrasound: Effect of Rosuvastatin Versus Atorvastatin (SATURN) used serial intravascular ultrasound measures of coronary atheroma volume in patients treated with rosuvastatin 40 mg or atorvastatin 80 mg for 24 months. The overall effect of high-intensity statins on the change in coronary percent atheroma volume and major adverse cardiovascular events (death/nonfatal myocardial infarction/coronary revascularization) were evaluated in this post hoc analysis. When compared with non-ACS patients (n=678), patients with ACS (n=361) were younger, actively smoking, and have had a previous myocardial infarction (all P<0.001). At baseline, patients with ACS exhibited lower high-density lipoprotein cholesterol (43.5±11 versus 45.8±11 mg/dL; P=0.002), a higher apolipoprotein B: apolipoprotein A-1 ratio (0.90±0.24 versus 0.83±0.24; P<0.001) and greater percent atheroma volume (37.3±8.5% versus 35.9±8.1%; P=0.01) when compared with non-ACS patients. Despite similar achieved levels of lipid and inflammatory markers after high-intensity statin therapy, patients with ACS demonstrated greater percent atheroma volume regression than non-ACS patients (-1.46±0.14 versus -0.89±0.13; P=0.003). After propensity-weighted multivariable adjustment, baseline percent atheroma volume (P<0.001) and an ACS clinical presentation (P=0.02) independently associated with plaque regression. The 24-month major adverse cardiovascular events-free survival was similar between patients with ACS and non-ACS (90.6 versus 92.9%; P=0.25). Long-term high-intensity statin therapy caused greater plaque regression and comparable major adverse cardiovascular events rates in

  9. INTRAVASCULAR ULTRASOUND EVALUATING CORONARY STENTS FOR PATIENTS WITH CORONARY ARTERY DISEASE: COMPARED OLD WITH NEW MULTILINK STENTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective.It was suggested that coronary stent design and coating may affect stent performance and hence induce varying degrees of thrombogenesis and neointimal hyperplasia.The purpose of this study is to compare the 6 month follow up results between old and new Multilink stents with the method of intravascular ultrasound (IVUS) imaging.Methods.We have performed old (n=40) and new (n=35) Multilink stent implantations on 75 patients with coronary artery disease.Coronary angiography was performed before,immediately after,and 6 months after the in stent procedure respectively.Six month follow up IVUS imaging was performed and analyzed off line.Results.Minimal lumen cross sectional area (CSA) of new Multilink stents was significantly larger than that of old Multilink stents (P=0.0053).Mean stent lumen area of new Multilink stents was significantly larger than that of old Multilink stents (P=0.040).Similarly,minimal lumen diameter (MLD) of new Multilink stents was larger than that of old Multilink stents (P= 0.011).Old Multilink stents had a higher percentage of plaque area than new Multilink stents.Conclusion.The new Multilink stent is obviously superior to old Multilink stents,in particular,in the stent MLD and lumen CSA- - major determinants of the restenosis.

  10. Supervised domain adaptation of decision forests: Transfer of models trained in vitro for in vivo intravascular ultrasound tissue characterization.

    Science.gov (United States)

    Conjeti, Sailesh; Katouzian, Amin; Roy, Abhijit Guha; Peter, Loïc; Sheet, Debdoot; Carlier, Stéphane; Laine, Andrew; Navab, Nassir

    2016-08-01

    In this paper, we propose a supervised domain adaptation (DA) framework for adapting decision forests in the presence of distribution shift between training (source) and testing (target) domains, given few labeled examples. We introduce a novel method for DA through an error-correcting hierarchical transfer relaxation scheme with domain alignment, feature normalization, and leaf posterior reweighting to correct for the distribution shift between the domains. For the first time we apply DA to the challenging problem of extending in vitro trained forests (source domain) for in vivo applications (target domain). The proof-of-concept is provided for in vivo characterization of atherosclerotic tissues using intravascular ultrasound signals, where presence of flowing blood is a source of distribution shift between the two domains. This potentially leads to misclassification upon direct deployment of in vitro trained classifier, thus motivating the need for DA as obtaining reliable in vivo training labels is often challenging if not infeasible. Exhaustive validations and parameter sensitivity analysis substantiate the reliability of the proposed DA framework and demonstrates improved tissue characterization performance for scenarios where adaptation is conducted in presence of only a few examples. The proposed method can thus be leveraged to reduce annotation costs and improve computational efficiency over conventional retraining approaches.

  11. Early characterization of atherosclerotic coronary plaques with multidetector computed tomography in patients with acute coronary syndrome. A comparative study with intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Iriart, Xavier; Dos-Santos, Pierre [Universite Bordeaux 2, Inserm U. 441 Atherosclerose, Bordeaux (France); Brunot, Sebastien [CHU de Bordeaux, Hopital du Haut-Leveque, Unite d' Imagerie Thoracique et Cardiovasculaire, Pessac (France); Unite de Soins Intensifs Cardiologiques, Pessac (France); Unite d' Imagerie Thoracique et Cardiovasculaire, Hopital Cardiologique, Pessac (France); Coste, Pierre; Leroux, Lionel [Universite Bordeaux 2, Inserm U. 441 Atherosclerose, Bordeaux (France); Unite de Soins Intensifs Cardiologiques, Pessac (France); Montaudon, Michel [Universite Bordeaux 2, Inserm U. 885 F 33076, Bordeaux (France); CHU de Bordeaux, Hopital du Haut-Leveque, Unite d' Imagerie Thoracique et Cardiovasculaire, Pessac (France); Labeque, Jean-Noel; Jais, Catherine [Unite de Soins Intensifs Cardiologiques, Pessac (France); Laurent, Francois [Universite Bordeaux 2, Inserm U. 885 F 33076, Bordeaux (France); CHU de Bordeaux, Hopital du Haut-Leveque, Unite d' Imagerie Thoracique et Cardiovasculaire, Pessac (France); Unite d' Imagerie Thoracique et Cardiovasculaire, Hopital Cardiologique, Pessac (France)

    2007-10-15

    We compared 16-slice computed tomography (CT) with intravascular ultrasound (IVUS) in their ability to identify the culprit lesion, and to assess plaque characterization and vascular remodelling in acute coronary syndrome (ACS). Twenty patients were prospectively studied. Coronary plaque identification and characterization were compared using 16-slice CT and 40-MHz catheter-based IVUS. Minimum lumen area (MLA), cross-sectional vessel area (CVA) and vessel remodelling were determined for each comparable lesion. One hundred and sixty-nine segments were compared and 84 plaques analysed. Sixteen-slice CT detected 95% of culprit lesions (19/20). No feature suggestive of plaque rupture was detected by 16-slice CT. Attenuation measurements within all lesions revealed different values for hypoechoic (38 {+-} 33 HU), hyperechoic (94 {+-} 44 HU), and calcified plaques (561 {+-} 216 HU), (P < 0.001). Agreement between 16-slice CT and IVUS on measuring MLA and CVA was evaluated using Bland-Altman analysis. Pearson and intra-class coefficient (ICC) were 0.81 and 0.70 for MLA, and 0.81 and 0.36 for CVA, for 16-slice CT and IVUS, respectively. Agreement between both techniques for vessel positive remodelling was moderate (kappa = 0.54, P < 0.001). Sixteen-slice CT has shown moderate accuracy in quantifying and characterizing coronary plaques compared with IVUS. Spatial resolution of 16-slice CT remains a major limitation, however, to accurately assess the complex lesions involved in ACS. (orig.)

  12. Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20-60 MHz phantom and ex vivo results.

    Science.gov (United States)

    Park, Jinhyoung; Li, Xiang; Zhou, Qifa; Shung, K Kirk

    2013-02-01

    The application of chirp coded excitation to pulse inversion tissue harmonic imaging can increase signal to noise ratio. On the other hand, the elevation of range side lobe level, caused by leakages of the fundamental signal, has been problematic in mechanical scanners which are still the most prevalent in high frequency intravascular ultrasound imaging. Fundamental chirp coded excitation imaging can achieve range side lobe levels lower than -60dB with Hanning window, but it yields higher side lobes level than pulse inversion chirp coded tissue harmonic imaging (PI-CTHI). Therefore, in this paper a combined pulse inversion chirp coded tissue harmonic and fundamental imaging mode (CPI-CTHI) is proposed to retain the advantages of both chirp coded harmonic and fundamental imaging modes by demonstrating 20-60MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50μm when two beamlines of pulse inversion pair are acquired. CPI-CTHI is implemented for a proto-typed intravascular ultrasound scanner capable of combined data acquisition in real-time. A wire phantom study shows that CPI-CTHI has a 12dB lower range side lobe level and a 7dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50μm finer and -3dB less than fundamental chirp coded excitation imaging respectively. Ex vivo scanning of a rabbit trachea demonstrates that CPI-CTHI is capable of visualizing blood vessels as small as 200μm in diameter with 6dB better tissue contrast than either PI-CTHI or fundamental chirp coded excitation imaging. These results clearly indicate that CPI-CTHI may enhance tissue contrast with less range side lobe level than PI-CTHI. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Real-time intravascular ultrasound/photoacoustic imaging system with omni-directional light excitation

    Science.gov (United States)

    Hsieh, Bao-Yu; Li, Pai-Chi

    2012-02-01

    Photoacoustic (PA) imaging has been investigated for intravascular applications. One of the main challenges is that the imaging frame rate is limited by the pulse repetition frequency (PRF), thus making real-time imaging difficult with most high-power solid-state pulse lasers. The goal of this study is to combine omni-directional optical excitation with a ring array transducer for high-frame-rate imaging, so that the image frame rate is the same as the laser PRF. In the preliminary study, we developed a real-time integrated IVUS/IVPA imaging system by modifying an IVUS system in combination with a high-speed Nd:YLF pulsed laser. In addition, an optical fiber with axicon-like distal tip is designed for omni-directional excitation. In this design, a PA image is acquired without rotating the laser light. The imaging frame rate of this integrated imaging system is 19 fps. Both US and PA images are recorded at the same time and co-registered in the fusion image. The US/PA images of tungsten wire, black tube and rabbit's atherosclerotic aorta were acquired with this integrated system to evaluate its imaging performance. The lateral/axial -6 dB resolution of US image is 2.56°/62.4μm. Resolution of PA imaging is 3.76°/91.5μm. The imaging system was also utilized to acquire IVUS/IVPA images of atherosclerotic rabbit's aorta in ex vivo study.

  14. Invasive evaluation of plaque morphology of symptomatic superficial femoral artery stenoses using combined near-infrared spectroscopy and intravascular ultrasound.

    Science.gov (United States)

    Zacharias, Sibin K; Safian, Robert D; Madder, Ryan D; Hanson, Ivan D; Pica, Mark C; Smith, James L; Goldstein, James A; Abbas, Amr E

    2016-08-01

    The purpose of this study is to characterize the plaque morphology of severe stenoses in the superficial femoral artery (SFA) employing combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS). Atherosclerosis is the most common cause of symptomatic peripheral arterial disease. Plaque composition of SFA stenoses has been characterized as primarily fibrous or fibrocalcific by non-invasive and autopsy studies. NIRS has been validated to detect lipid-core plaque (LCP) in the coronary circulation. We imaged severe SFA stenoses with NIRS-IVUS prior to revascularization in 31 patients (46 stenoses) with Rutherford claudication ⩾ class 3. Angiographic parameters included lesion location and stenosis severity. IVUS parameters included plaque burden and presence of calcium. NIRS images were analyzed for LCP and maximum lipid-core burden index in a 4-mm length of artery (maxLCBI4mm). By angiography, 38 (82.6%) lesions were calcified and 9 (19.6%) were chronic total occlusions. Baseline stenosis severity and lesion length were 86.0 ± 11.0% and 36.5 ± 46.5 mm, respectively. NIRS-IVUS identified calcium in 45 (97.8%) lesions and LCP in 17 (37.0%) lesions. MaxLCBI4mm was 433 ± 244. All lesions with LCP also contained calcium; there were no non-calcified lesions with LCP. In conclusion, this is the first study of combined NIRS-IVUS in patients with PAD. NIRS-IVUS demonstrates that nearly all patients with symptomatic severe SFA disease have fibrocalcific plaque, and one-third of such lesions contain LCP. These findings contrast with those in patients with acute coronary syndromes, and may have implications regarding the pathophysiology of atherosclerosis in different vascular beds.

  15. Impact of intravascular ultrasound on the long-term clinical outcomes in the treatment of coronary ostial lesions.

    Science.gov (United States)

    Patel, Yogesh; Depta, Jeremiah P; Patel, Jayendrakumar S; Masrani, Shriti K; Novak, Eric; Zajarias, Alan; Kurz, Howard I; Lasala, John M; Bach, Richard G; Singh, Jasvindar

    2016-02-01

    To evaluate the long-term outcomes of patients with ostial lesions who underwent percutaneous coronary intervention (PCI) with and without the use of intravascular ultrasound (IVUS). A higher rate of adverse cardiac events is associated with PCI of ostial lesions as compared with nonostial disease. From 7/2002 to 8/2010, 225 patients with 233 coronary ostial lesions underwent PCI with (n = 82) and without (n = 143) IVUS guidance. Ostial lesions included both native aorto-ostial or major coronary vessel (left anterior descending, left circumflex, and ramus intermedius) lesions. Clinical outcomes [cardiovascular death, myocardial infarction (MI), and target lesion revascularization (TLR)] at a mean follow-up of 4.2 ± 2.5 years were compared between patients undergoing PCI of an ostial lesion with and without use of IVUS using univariate and propensity score adjusted analyses. Aorto-ostial lesions (n = 109) comprised 47% of lesions, whereas the remaining lesions (53%) involved major coronary vessels. After propensity score adjustment, IVUS use was associated with lower rates of the composite of cardiovascular death, MI, or TLR (HR 0.54, 95% CI 0.29-0.99; P = 0.04), composite MI or TLR (HR 0.39, 95% CI 0.18-0.83; P = 0.01), and MI (HR 0.31, 95% CI 0.11-0.85; P = 0.02) as compared with no IVUS. The use of IVUS was also associated with a trend towards a lower rate of TLR (HR 0.42, 95% CI 0.17-1.02; P = 0.06). PCI of coronary ostial lesions with the use of IVUS was associated with significantly lower rates of adverse cardiac events. © 2015 Wiley Periodicals, Inc.

  16. Coronary bifurcation lesions treated with double kissing crush technique compared to classical crush technique: serial intravascular ultrasound analysis.

    Science.gov (United States)

    Shan, Shou-Jie; Ye, Fei; Liu, Zhi-Zhong; Tian, Nai-Liang; Zhang, Jun-Jie; Chen, Shao-Liang

    2013-04-01

    The double kissing (DK) crush technique is a modified version of the crush technique. It is specifically designed to increase the success rate of the final kissing balloon post-dilatation, but its efficacy and safety remain unclear. Data were obtained from the DKCRUSH-I trial, a prospective, randomized, multi-center study to evaluate safety and efficacy. Post-procedural and eight-month follow-up intravascular ultrasound (IVUS) analysis was available in 61 cases. Volumetric analysis using Simpson's method within the Taxus stent, and cross-sectional analysis at the five sites of the main vessel (MV) and three sites of the side branch (SB) were performed. Impact of the bifurcation angle on stent expansion at the carina was also evaluated. Stent expansion in the SB ostium was significantly less in the classical crush group ((53.81 ± 13.51)%) than in the DK crush group ((72.27 ± 11.46)%) (P = 0.04). For the MV, the incidence of incomplete crush was 41.9% in the DK group and 70.0% in the classical group (P = 0.03). The percentage of neointimal area at the ostium had a tendency to be smaller in the DK group compared with the classical group ((16.4 ± 19.2)% vs. (22.8 ± 27.1)%, P = 0.06). The optimal threshold of post-procedural minimum stent area (MSA) to predict follow-up minimum lumen area (MLA) kissing balloon inflation (FKBI) and had smaller optimal cutoff value of post-procedural MSA at the SB ostium.

  17. A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, Stéphane, E-mail: sgcarlier@hotmail.com [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium); Department of Cardiology, Erasme University Hospital, Université Libre de Bruxelles (ULB), Brussels (Belgium); Didday, Rich [INDEC Medical Systems Inc., Santa Clara, CA (United States); Slots, Tristan [Pie Medical Imaging BV, Maastricht (Netherlands); Kayaert, Peter; Sonck, Jeroen [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium); El-Mourad, Mike; Preumont, Nicolas [Department of Cardiology, Erasme University Hospital, Université Libre de Bruxelles (ULB), Brussels (Belgium); Schoors, Dany; Van Camp, Guy [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium)

    2014-06-15

    We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator’s identification of landmarks to establish the image synchronization.

  18. Capacitação de enfermeiros para uso da ultrassonografia na punção intravascular periférica Capacitación de enfermeros en el uso de la ultrasonografía en la punción intravascular periférica Training of nurses in the use of intravascular ultrasound in peripheral puncture

    Directory of Open Access Journals (Sweden)

    Ariane Ferreira Machado Avelar

    2010-06-01

    Full Text Available Este artigo relata a estratégia de capacitação de enfermeiros para uso da ultrassonografia vascular na obtenção do acesso vascular periférico. O programa foi composto por intervenções educacionais teóricas e práticas desenvolvidas em um período de seis meses. As estratégias foram elaboradas e implementadas por dois enfermeiros especialistas em terapia intravascular, um médico especialista em ultrassonografia vascular e um engenheiro biomédico. Oito enfermeiros participaram da capacitação e, ao final, os conhecimentos, as competências e habilidades adquiridas na identificação de artérias, veias, fluxo sanguíneo e posicionamento de cateteres foram avaliados. A estratégia possibilitou que enfermeiros pediatras adquirissem competências capazes de promover intervenções inovadoras na punção intravascular periférica.Este artículo relata la estrategia de capacitación de enfermeros en el uso de la ultrasonografía vascular en la obtención del acceso vascular periférico. El programa estuvo compuesto por intervenciones educacionales teóricas y prácticas desarrolladas en un período de seis meses. Las estrategias fueron elaboradas e implementadas por dos enfermeros especialistas en terapia intravascular, un médico especialista en ultrasonografía vascular y, un ingeniero biomédico. Ocho enfermeros participaron de la capacitación. Al final, los conocimientos, las competencias y habilidades adquiridas en la identificación de arterias, venas, flujo sanguíneo y posición de catéteres, fueron evaluados. La estrategia posibilitó que los enfermeros pediatras adquiriesen competencias capaces de promover intervenciones innovadoras en la punción intravascular periférica.The objective was to explain, to the nurses training, procedures using vascular ultrasound for obtaining peripheral vascular access. The program consisted of theoretical and practical educational interventions developed over a period of six months. The

  19. Prediction of Outcome after Femoropopliteal Balloon Angioplasty by Intervascular Ultrasound

    DEFF Research Database (Denmark)

    Schroeder, Torben Veith; Vogt, Katja; Just, S.;

    1997-01-01

    original, intravascular ultrasound, percutaneous transluminal angioplasty, peripheral arteries, plaquemorphology, prediction of outcome......original, intravascular ultrasound, percutaneous transluminal angioplasty, peripheral arteries, plaquemorphology, prediction of outcome...

  20. Relationship among coronary plaque compliance, coronary risk factors and tissue characteristics evaluated by integrated backscatter intravascular ultrasound

    Directory of Open Access Journals (Sweden)

    Ishihara Yoshiyuki

    2012-07-01

    Full Text Available Abstract Background The purpose of the present study was to evaluate the mechanical properties of coronary plaques and plaque behavior, and to elucidate the relationship among tissue characteristics of coronary plaques, mechanical properties and coronary risk factors using integrated backscatter intravascular ultrasound (IB-IVUS. Methods Non-targeted plaques with moderate stenosis (plaque burden at the minimal lumen site: 50-70% located proximal to the site of the percutaneous coronary intervention target lesions were evaluated by IB-IVUS. Thirty-six plaques (less calcified group: an arc of calcification ≤10° in 36 patients and 22 plaques (moderately calcified group: 10°  Results In the less calcified group, there was a significant correlation between EEMV compliance and the relative lipid volume (r = 0.456, p = 0.005. There was a significant inverse correlation between EEM area stiffness index and the relative lipid volume (p = 0.032, r = −0.358. The LV compliance and EEM area stiffness index were significantly different in the diabetes mellitus (DM group than in the non-DM group (1.32 ± 1.49 vs. 2.47 ± 1.79%/10 mmHg, p =0.014 and 28.3 ± 26.0 vs. 15.7 ± 17.2, p =0.020. The EEMV compliance and EEM area stiffness index were significantly different in the hypertension (HTN group than in the non-HTN group (0.77 ± 0.68 vs. 1.57 ± 0.95%/10 mmHg, p =0.012 and 26.5 ± 24.3 vs. 13.0 ± 16.7, p =0.020. These relationships were not seen in the moderately calcified group. Conclusion The present study provided new findings that there was a significant correlation between mechanical properties and tissue characteristics of coronary arteries. In addition, our results suggested that the EEMV compliance and the LV compliance were independent and the compliance was significantly impaired in the patients with DM and/or HTN. Assessment of coronary mechanical properties during PCI may provide us with

  1. Coronary bifurcation lesions treated with double kissing crush technique compared to classical crush technique: serial intravascular ultrasound analysis

    Institute of Scientific and Technical Information of China (English)

    SHAN Shou-jie; YE Fei; LIU Zhi-zhong; TIAN Nai-liang; ZHANG Jun-jie; HEN Shao-liang

    2013-01-01

    Background The double kissing (DK) crush technique is a modified version of the crush technique.It is specifically designed to increase the success rate of the final kissing balloon post-dilatation,but its efficacy and safety remain unclear.Methods Data were obtained from the DKCRUSH-I trial,a prospective,randomized,multi-center study to evaluate safety and efficacy.Post-procedural and eight-month follow-up intravascular ultrasound (IVUS) analysis was available in 61 cases.Volumetric analysis using Simpson's method within the Taxus stent,and cross-sectional analysis at the five sites of the main vessel (MV) and three sites of the side branch (SB) were performed.Impact of the bifurcation angle on stent expansion at the carina was also evaluated.Results Stent expansion in the SB ostium was significantly less in the classical crush group ((53.81±13.51)%) than in the DK crush group ((72.27±11.46)%) (P=-0.04).For the MV,the incidence of incomplete crush was 41.9% in the DK group and 70.0% in the classical group (P=-0.03).The percentage of neointimal area at the ostium had a tendency to be smaller in the DK group compared with the classical group ((16.4±19.2)% vs.(22.8±27.1)%,P=-0.06).The optimal threshold of post-procedural minimum stent area (MSA) to predict follow-up minimum lumen area (MLA) <4.0 mm2 at the SB ostium was 4.55 mm2,yielding an area under the curve of 0.80 (95% confidence interval:0.61 to 0.92).Conclusion Our data suggest that the DK crush technique is associated with improved quality of the final kissing balloon inflation (FKBI) and had smaller optimal cutoff value of post-procedural MSA at the SB ostium.

  2. The use of intravascular ultrasound for intraoperative assessment during semiclosed thromboendarterectomy

    DEFF Research Database (Denmark)

    Vogt, K C; Sillesen, H; Schroeder, T V

    1998-01-01

    in the artery proximal to the endarterectomized area were measured and, along with any remaining material, related to patency. Patency was evaluated at clinical controls after 3, 6, 12 and 24 months with duplex scanning and ankle-brachial index. In 10 cases (50%), material left behind from the endarterectomy...

  3. Low variation and high reproducibility in plaque volume with intravascular ultrasound

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Pedersen, Knud Erik;

    2004-01-01

    by electrocardiographic-gated three-dimensional (3D) IVUS in 20 male patients with ischaemic heart disease (IHD). RESULTS: The study lesions were angiographically insignificant, with a length of the analysed segment on 11.4+/-5.9 mm. At baseline the mean minimal lumen diameter was 2.41+/-0.59 mm, minimal lumen area 4.......82+/-2.38 mm2, and maximal plaque burden 65.61+/-9.57%. Mean reference diameter was 3.1+/-0.6 mm. No significant changes were observed in volumes of total vessel, lumen or plaque. The coefficient of variation (CV) for two volume measurements at baseline was: vessel 0.8%, plaque 1.3%, and lumen 1.......4%. For measurements recorded at baseline and after 12.6+/-1.5 weeks, CV was respectively 3.5%, 3.3% and 6.6%. Reproducibility and interobserver and intraobserver variation showed very high correlations. A linear correlation was present in percent changes over 12.6+/-1.5 weeks between vessel volume and lumen volume (r...

  4. Late lumen loss and intima hyperplasia after sirolimus-eluting and zotarolimus-eluting stent implantation in diabetic patients: the diabetes and drug-eluting stent (DiabeDES III) angiography and intravascular ultrasound trial

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Mæng, Michael; Thayssen, Per;

    2011-01-01

    Patients with diabetes mellitus have increased risk of in-stent restenosis after coronary stent implantation due to neointimal hyperplasia (NIH). The aim of this study was to use quantitative coronary angiography (QCA) and volumetric intravascular ultrasound (IVUS) to evaluate the effects of the ...

  5. Intravascular ultrasound findings in the multicenter, randomized, double-blind RAVEL (RAndomized study with the sirolimus-eluting VElocity balloon- expandable stent in the treatment of patients with de novo native coronary artery Lesions) trial

    NARCIS (Netherlands)

    J.M.R. Ligthart (Jürgen); M-C. Morice (Marie-Claude); P.J. de Feyter (Pim); M. Degertekin (Muzaffer); K. Tanabe (Kengo); J.E. Sousa (Eduardo); A. Colombo (Antonio); G. Guagliumi (Giulio); W. Wijns (William); W.K. Lindeboom (Wietze); P.W.J.C. Serruys (Patrick); A.C. Abizaid (Alexandre)

    2002-01-01

    textabstractBACKGROUND: The goal of this intravascular ultrasound investigation was to provide a more detailed morphological analysis of the local biological effects of the implantation of a sirolimus-eluting stent compared with an uncoated stent. METHODS AND RESULTS: In the RAVEL trial, 238 patient

  6. Effect of Folic Acid Supplementation on Levels of Circulating Monocyte Chemoattractant Protein-1 and the Presence of Intravascular Ultrasound Derived Virtual Histology Thin-Cap Fibroatheromas in Patients with Stable Angina Pectoris

    NARCIS (Netherlands)

    K.H. Løland (Kjetil); O. Bleie (Oyvind); E. Strand (Elin); P.M. Ueland (Per); J. Nordrehaug (Jan); H.M. Garcia-Garcia (Hector); P.W.J.C. Serruys (Patrick); O. Nygård (Ottar)

    2013-01-01

    textabstractBackground:Virtual Histology Intravascular Ultrasound (VH-IVUS) may be used to detect early signs of unstable coronary artery disease. Monocyte Chemoattractant Protein-1 (MCP-1) is linked with coronary atherosclerosis and plaque instability and could potentially be modified by folic acid

  7. Spinal curvature measurement by tracked ultrasound snapshots.

    Science.gov (United States)

    Ungi, Tamas; King, Franklin; Kempston, Michael; Keri, Zsuzsanna; Lasso, Andras; Mousavi, Parvin; Rudan, John; Borschneck, Daniel P; Fichtinger, Gabor

    2014-02-01

    Monitoring spinal curvature in adolescent kyphoscoliosis requires regular radiographic examinations; however, the applied ionizing radiation increases the risk of cancer. Ultrasound imaging is favored over radiography because it does not emit ionizing radiation. Therefore, we tested an ultrasound system for spinal curvature measurement, with the help of spatial tracking of the ultrasound transducer. Tracked ultrasound was used to localize vertebral transverse processes as landmarks along the spine to measure curvature angles. The method was tested in two scoliotic spine models by localizing the same landmarks using both ultrasound and radiographic imaging and comparing the angles obtained. A close correlation was found between tracked ultrasound and radiographic curvature measurements. Differences between results of the two methods were 1.27 ± 0.84° (average ± SD) in an adult model and 0.96 ± 0.87° in a pediatric model. Our results suggest that tracked ultrasound may become a more tolerable and more accessible alternative to radiographic spine monitoring in adolescent kyphoscoliosis.

  8. Comparison of two- and three-dimensional quantitative coronary angiography to intravascular ultrasound in the assessment of intermediate left main stenosis.

    Science.gov (United States)

    Porto, Italo; Dato, Ilaria; Todaro, Daniel; Calabrese, Michele; Rigattieri, Stefano; Leone, Antonio Maria; Niccoli, Giampaolo; Burzotta, Francesco; Trani, Carlo; Crea, Filippo

    2012-06-01

    Angiographic evaluation of intermediate left main coronary artery stenosis (LMS) is often limited. Three-dimensional (3D) quantitative coronary angiography has recently developed to overcome 2-dimensional (2D) quantitative coronary angiographic (QCA) limitations. In patients with angiographically intermediate LMS, we investigated whether 3D quantitative coronary angiography was superior to 2D quantitative coronary angiography in predicting the presence of a significant LMS, defined as a minimum luminal area <6 mm(2) at intravascular ultrasound (IVUS). 2D and 3D quantitative coronary angiography were compared in their measurements of minimum luminal area, percent area stenosis, minimum luminal diameter, and percent diameter stenosis and in their prediction of an IVUS minimum luminal area <6 mm(2). In total 58 target lesions were interrogated, 25 (43%) of which had an IVUS minimum luminal area <6 mm(2). Correlation between 3D-QCA minimum luminal area and IVUS minimum luminal area was stronger than the correlation between 2D-QCA minimum luminal area (or minimum luminal diameter) and IVUS minimum luminal area (R = 0.67, p = 0.0001, and R = 0.40, p = 0.001, respectively, p = 0.04 for comparison). To predict IVUS minimum luminal area <6 mm(2), the most accurate 2D-QCA measurement was minimum luminal diameter (area under curve 0.81, cutoff 2.2 mm, p = 0.0001), and the most accurate 3D-QCA measurement was minimum luminal area (area under curve 0.86, cutoff 5.6 mm(2), p = 0.0001). 2D-QCA percent diameter stenosis did not significantly predict IVUS minimum luminal area <6 mm(2) (area under curve 0.56, cutoff 38%, p = 0.45). In conclusion, the accuracy of quantitative coronary angiography in predicting LM IVUS minimum luminal area <6 mm(2) is limited. When IVUS is not available or contraindicated, 3D quantitative coronary angiography may assist in the evaluation of intermediate LMS. Among 2D-QCA parameters, minimum luminal diameter is more accurate than percent diameter

  9. Comparison of neointimal morphology of in-stent restenosis with sirolimus-eluting stents versus bare metal stents: virtual histology-intravascular ultrasound analysis.

    Science.gov (United States)

    Yamamoto, Yoshihiro; Otani, Hajime; Iwasaka, Junji; Park, Haengnam; Sakuma, Takao; Kamihata, Hiroshi; Iwasaka, Toshiji

    2011-09-01

    Sirolimus-eluting stents (SES) have reduced the incidence of restenosis and target lesion revascularization compared to bare metal stents (BMS). However, inhibition of endothelialization and neointimal formation after SES implantation may produce vulnerable plaques. The present study compared the neointimal morphology of in-stent restenosis (ISR) between SES and BMS using virtual histology-intravascular ultrasound (VH-IVUS). Thirty ISR lesions (SES n = 15, BMS n = 15) demonstrated by coronary angiography in 30 patients with stable angina pectoris were analyzed with VH-IVUS between 6 months to 3 years after stent implantation. Tissue maps were reconstructed from radiofrequency data using VH-IVUS software. ISR lesions after SES implantation consisted of a significantly increased necrotic core (NC) compared to BMS (12.9 vs. 5.6% of neointimal volume, p stent thrombosis after SES implantation.

  10. Back-to-back optical coherence tomography-ultrasound probe for co-registered three-dimensional intravascular imaging with real-time display

    Science.gov (United States)

    Li, Jiawen; Ma, Teng; Jing, Joseph; Zhang, Jun; Patel, Pranav M.; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping

    2014-03-01

    We have developed a novel integrated optical coherence tomography (OCT)-intravascular ultrasound (IVUS) probe, with a 1.5 mm-long rigid-part and 0.9 mm outer diameter, for real-time intracoronary imaging of atherosclerotic plaques and guiding interventional procedures. By placing the OCT ball lens and IVUS 45MHz single element transducer back-to-back at the same axial position, this probe can provide automatically co-registered, co-axial OCT-IVUS imaging. To demonstrate its capability, 3D OCT-IVUS imaging of a pig's coronary artery in real-time displayed in polar coordinates, as well as images of two major types of advanced plaques in human cadaver coronary segments, was obtained using this probe and our upgraded system. Histology validation is also presented.

  11. Simultaneous occlusion of left anterior descending and left circumflex arteries by very late stent thrombosis: vascular response to drug-eluting stents assessed by intravascular ultrasound.

    Science.gov (United States)

    Yamawaki, Masahiro; Onuma, Yoshinobu; Nakano, Masatsugu; Muramatsu, Takashi; Nakatani, Shimpei; Ishibashi, Yuki; Ishimori, Hiroshi; Hirano, Keisuke; Ito, Yoshiaki; Tsukahara, Reiko; Muramatsu, Toshiya

    2015-11-01

    Very late stent thrombosis (VLST) is a catastrophic complication after implantation of a drug-eluting stent (DES). It has been reported that VLST is associated with pathological changes, which often include late acquired incomplete stent apposition (LAISA) with thrombus formation. In addition, the vascular response to the stent (evaginations, neointimal growth, and thrombosis) and the incidence of LAISA are reported to vary among the different types of DES. We experienced a patient with cardiogenic shock induced by simultaneous VLST of both the left anterior descending artery (LAD) and the left circumflex artery (LCX) at 3 years after implantation of two sirolimus-eluting stents. Intravascular ultrasound (IVUS) showed LAISA of both arteries. A paclitaxel-eluting stent, which had been implanted in the right coronary artery 3 years earlier, did not show such a finding. IVUS revealed "different vascular reactions" to "different types of DES" in this patient.

  12. Measurement of tissue viscoelasticity with ultrasound

    Science.gov (United States)

    Greenleaf, J. F.; Alizad, A.

    2017-02-01

    Tissue properties such as elasticity and viscosity have been shown to be related to such tissue conditions as contraction, edema, fibrosis, and fat content among others. Magnetic Resonance Elastography has shown outstanding ability to measure the elasticity and in some cases the viscosity of tissues, especially in the liver, providing the ability to stage fibrotic liver disease similarly to biopsy. We discuss ultrasound methods of measuring elasticity and viscosity in tissues. Many of these methods are becoming widely available in the extant ultrasound machines distributed throughout the world. Some of the methods to be discussed are in the developmental stage. The advantages of the ultrasound methods are that the imaging instruments are widely available and that many of the viscoelastic measurements can be made during a short addition to the normal ultrasound examination time. In addition, the measurements can be made by ultrasound repetitively and quickly allowing evaluation of dynamic physiologic function in circumstances such as muscle contraction or artery relaxation. Measurement of viscoelastic tissue mechanical properties will become a consistent part of clinical ultrasound examinations in our opinion.

  13. Atherosclerotic plaque components characterization and macrophage infiltration identification by intravascular ultrasound elastography based on b-mode analysis: validation in vivo.

    Science.gov (United States)

    Zhang, Peng-Fei; Su, Hai-Jun; Zhang, Mei; Li, Ji-Fu; Liu, Chun-Xi; Ding, Shi-Fang; Miao, Ya; Chen, Liang; Li, Xiao-Nan; Yi, Xin; Zhang, Yun

    2011-01-01

    Intravascular ultrasound elastography (IVUSE) is a promising imaging technique for early investigation of vulnerable plaques. Compared to radiofrequency signal processing, digital B-mode analysis is simple and of higher portability. However, rare studies have been reported validating the latter technique in vivo. In this study, we developed an IVUSE computer software system involving semi-automatic border delineation and block-matching algorithm and validated the system in vivo. Seven minipigs were fed with atherogenic diet for 40 weeks. For each pig, the endothelium of one side of the renal arteries was denuded at the fifth week. With cross-correlation analysis, Lagrangian strain was calculated from two intravascular ultrasound images acquired in situ. Sixty regions of interests were selected from 35 elastograms matched well with the corresponding histological slices. Plaque types within these regions were classified as fibrous, fibro-fatty or fatty on Masson's trichrome and Oil-red O staining. Macrophage infiltration was also evaluated with immunohistology. Comparison between the mean strain value of the region of interest and the histological results revealed significant differences in strain values among different plaque types and non-diseased artery walls. The extent of macrophage infiltration was found to be correlated positively with strain values. For identification of fibro-fatty and fibrous plaques and macrophage infiltration, the system showed high sensitivity (93, 96 and 92%, respectively) and specificity (89, 76 and 66%, respectively), as revealed by receiver operating characteristic analysis. Our IVUSE system based on B-mode analysis is capable of characterizing fibrous and fibro-fatty plaques and macrophage intensity, thus holds potential for identifying vulnerable plaque.

  14. The qualitative assessment of biodegradable coronary stents with the use of intravascular ultrasound, optical coherence tomography and histology

    OpenAIRE

    Burcu GÜL

    2014-01-01

    Percutaneous coronary intervention (PCI) is the most common treatment for coronary artery disease (CAD). The first form of PCI introduced was balloon angioplasty. After that, the advent of coronary stents (tubular wire mesh for intravascular mechanical support) led to a new era in interventional cardiology. Through the implantation of bare metal stents (BMS), all three limitations of balloon angioplasty – coronary artery dissection, elastic recoil and negative remodelling – are prevented. Unf...

  15. Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

    DEFF Research Database (Denmark)

    Tearney, Guillermo J; Regar, Evelyn; Akasaka, Takashi

    2012-01-01

    The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the di...

  16. Assessment of carotid plaque composition using fast-kV switching dual-energy CT with gemstone detector: comparison with extracorporeal and virtual histology-intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Shinohara, Yuki; Kuya, Keita; Ohta, Yasutoshi; Fujii, Shinya; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Yonago (Japan); Sakamoto, Makoto; Watanabe, Takashi [Tottori University, Division of Neurosurgery, Department of Neurological Sciences, Faculty of Medicine, Yonago (Japan); Kishimoto, Junichi; Iwata, Naoki [Tottori University Hospital, Division of Clinical Radiology, Yonago (Japan)

    2015-09-15

    The present study compares the applicability of CT carotid plaque imaging using effective Z maps using gemstone spectral imaging (GSI) with that of conventional extracorporeal carotid ultrasound (US) and virtual histology-intravascular ultrasound (VH-IVUS). We assessed stenosis in 31 carotid arteries of 30 patients. All patients underwent carotid CTA using GSI (Discovery CT750 HD, GE Healthcare). US and IVUS were examined with 25 and 8 vessels, respectively. We compared the effective Z values at noncalcified carotid plaque with the plaque components identified by US. We defined the plaque with low or low to iso intensity on US as vulnerable plaque and the plaque with iso, iso to high, and high intensity on US as stable plaque. We also performed visual assessment of color-coded effective Z maps in comparison with VH-IVUS and compared effective Z values with plaque components generated by VH-IVUS. The effective Z values at noncalcified carotid plaque were significantly lower for a group with vulnerable plaque, than with stable plaque on US (p < 0.05). Receiver operating curve analysis showed that AUC of effective Z values was 0.882 concerning the differentiation of these two groups on US. The interpretation of color-coded effective Z maps was essentially compatible with that of VH-IVUS for carotid plaque in all vessels. Effective Z values at noncalcified plaque showed significant negative correlation with the areas of fibro-fatty components generated by VH-IVUS (ρ = -0.874, p < 0.05). Effective Z maps generated by GSI can detect vulnerable carotid plaque materials. (orig.)

  17. Evaluation of Variable Thin-Cap Fibroatheroma Definitions and Association of Virtual Histology-Intravascular Ultrasound Findings With Cavity Rupture Size.

    Science.gov (United States)

    Hirai, Taishi; Chen, Zhi; Zhang, Ling; Baaj, Shamsa; Kovarnik, Tomas; Porcaro, Katie; Kaminski, John; Hawn, Stephen; Agrawal, Anoop; Makki, Nader; Downe, Richard; Wahle, Andreas; Sonka, Milan; Lopez, John J

    2016-07-15

    The accepted definition of virtual histology intravascular ultrasound (IVUS-VH) thin-cap fibroatheroma (TCFA) is only a modest predictor of plaque rupture (PR). We sought to determine the relation between IVUS-VH findings and culprit lesions with PR using computational analysis. A total of 80 culprit lesions from 80 patients with stable angina (n = 37), unstable angina (n = 20), and myocardial infarction (n = 23) were divided into those with (n = 15) and without PR (n = 65). By use of automated computational analysis, the standard IVUS-VH TCFA criterion and 124 additional criteria were compared. The standard TCFA definition demonstrated modest ability to discriminate lesions with and without PR (sensitivity 87%, specificity 37%, PPV 0.24, and NPV 0.92). Of 124 additional IVUS-VH TCFA definitions, only 2 improved the discriminative ability even modestly. However, a positive correlation was demonstrated between cavity size and necrotic core percentage (r = 0.78, p VH criteria were only modestly associated with PR, without significant improvement by varying IVUS-VH TCFA features, but IVUS-VH features of ruptured plaques were strongly correlated with cavity size.

  18. Enhanced characterization of calcified areas in intravascular ultrasound virtual histology images by quantification of the acoustic shadow: validation against computed tomography coronary angiography.

    Science.gov (United States)

    Broersen, Alexander; de Graaf, Michiel A; Eggermont, Jeroen; Wolterbeek, Ron; Kitslaar, Pieter H; Dijkstra, Jouke; Bax, Jeroen J; Reiber, Johan H C; Scholte, Arthur J

    2016-04-01

    We enhance intravascular ultrasound virtual histology (VH) tissue characterization by fully automatic quantification of the acoustic shadow behind calcified plaque. VH is unable to characterize atherosclerosis located behind calcifications. In this study, the quantified acoustic shadows are considered calcified to approximate the real dense calcium (DC) plaque volume. In total, 57 patients with 108 coronary lesions were included. A novel post-processing step is applied on the VH images to quantify the acoustic shadow and enhance the VH results. The VH and enhanced VH results are compared to quantitative computed tomography angiography (QTA) plaque characterization as reference standard. The correlation of the plaque types between enhanced VH and QTA differs significantly from the correlation with unenhanced VH. For DC, the correlation improved from 0.733 to 0.818. Instead of an underestimation of DC in VH with a bias of 8.5 mm(3), there was a smaller overestimation of 1.1 mm(3) in the enhanced VH. Although tissue characterization within the acoustic shadow in VH is difficult, the novel algorithm improved the DC tissue characterization. This algorithm contributes to accurate assessment of calcium on VH and could be applied in clinical studies.

  19. Ultrasound transducer assembly and method for manufacturing an ultrasound transducer assembly

    NARCIS (Netherlands)

    Dekker, R.; Henneken, V.A.; Louwerse, M.C.; Raganato, M.F.

    2015-01-01

    The present invention relates to an ultrasound transducer assembly (10), in particular for intravascular ultrasound systems. The ultrasound transducer assembly comprises at least one silicon substrate element (30) including an ultrasound transducer element (14) for emitting and receiving ultrasound

  20. Ultrasound transducer assembly and method for manufacturing an ultrasound transducer assembly

    NARCIS (Netherlands)

    Dekker, R.; Henneken, V.A.; Louwerse, M.C.; Raganato, M.F.

    2015-01-01

    The present invention relates to an ultrasound transducer assembly (10), in particular for intravascular ultrasound systems. The ultrasound transducer assembly comprises at least one silicon substrate element (30) including an ultrasound transducer element (14) for emitting and receiving ultrasound

  1. Automated Retrieval of Key Frames from Intravascular Ultrasound Image Sequences%血管内超声图像序列关键帧的自动检索

    Institute of Scientific and Technical Information of China (English)

    王立欣; 孙正

    2015-01-01

    Manual retrieval of key frames from an Intravascular Ultrasound (IVUS) pullback sequence is a tedious and time-consuming task. The retrieval results are subjective and highly depend on clinical experiences and professional knowledge of the operator. In this paper, two methods for automatically retrieving key frames in an IVUS image sequence are proposed. One is based on the description of the vascular morphology. First, the morphological profiles of vessel are extracted. Then, the sequences of cross-sectional areas in each frame are coded with the symbolic aggregate approximation (SAX) algorithm. Finally, key frames are selected through comparing the Euclidean distances between the coded area sequences of successive frames with a properly selected threshold. The other is based on the histograms of IVUS images. The key frames are retrieved through comparing the Bhattacharyya distances between histograms of successive frames with a properly selected threshold. The validity of both methods has been validated in vivo image data and the accuracy was quantitatively evaluated. The results show that a higher compression ratio, lower redundancy and higher precision can be obtained with the morphological description method than the histogram method. However, its efficiency is relatively lower than the histogram method.%针对临床采集的血管内超声(Intravascular Ultrasound, IVUS)图像序列数据量巨大,由人工逐帧检查和分析非常繁琐且客观性差的问题,本文提出两种自动检索IVUS图像序列中关键帧的方法.其一是基于血管形态的方法:首先提取图像中的血管壁轮廓,并使用符号聚集近似(SAX)算法对轮廓包围区域的面积序列进行量化编码,进而计算出相邻两帧的血管横截面积序列之间的欧氏距离,提取出关键帧;其二是基于图像灰度直方图的方法,即通过计算图像灰度直方图之间的巴氏距离提取关键帧.利用临床采集的图像数据分别验证了两

  2. Value of intravascular ultrasound imaging in following up patients with replacement of the ascending aorta for acute type A aortic dissection

    Institute of Scientific and Technical Information of China (English)

    HU Wei; Francois Schiele; Nicolas Meneveau; Made-France Seronde; Pierre Legalery; Fiona Caulfield; Jean-Francois Bonneville; Sidney Chocron; Jean-Pierre Bassand

    2008-01-01

    Background The value of intravascular ultrasound (IVUS) imaging in patients with replacement of the ascending aorta for acute type A aortic dissection (AD) is unknown.The purpose of this study was to assess the potential use of IVUS imaging in this setting.Methods From September 2002 to July 2005,IVUS imaging with a 9 MHz probe was performed in a series of 16 consecutive patients with suspected or established AD.This study focused on 5 of them with replacement of the ascending aorta for acute type A AD.Among these 5 patients,other imaging modalities including aortography,spiral computed tomography,magnetic resonance imaging and transesophageal echocardiography were performed in 5,3,3 and 1 patients,respectively.Results There were no complications related to IVUS imaging.For the replaced graft,as other imaging modalities,IVUS could identify all 5 grafts,the proximal and the distal anastomoses,and the ostia of the reimplanted coronary arteries.In 2 cases,IVUS detected 2 peri-graft pseudo-aneurysms (1 per case),which were also detected by magnetic resonance imaging but omitted by aortography.For the residual dissection,IVUS had similar findings as other imaging modalities in detecting the patency (5/5),the longitudinal and the circumferential extent,the thrombus (4/5),the recurrent dissection (1/5) and an aneurysm distal to the graft (5 in 4 patients).However,it detected more intimal tears and side branch involvements than other imaging modalities (15 vs 10 and 3 vs 1,respectively).Conclusions In following-up patients with replacement of the ascending aorta for acute type A AD,IVUS imaging can provide complete information of the replaced graft and the residual dissection.So,IVUS imaging may be considered when the four current frequently used imaging modalities can not supply sufficient information or there are some discrepancies between them.

  3. Mechanisms and Patterns of Intravascular Ultrasound In-Stent Restenosis Among Bare Metal Stents and First- and Second-Generation Drug-Eluting Stents.

    Science.gov (United States)

    Goto, Kosaku; Zhao, Zhijing; Matsumura, Mitsuaki; Dohi, Tomotaka; Kobayashi, Nobuaki; Kirtane, Ajay J; Rabbani, LeRoy E; Collins, Michael B; Parikh, Manish A; Kodali, Susheel K; Leon, Martin B; Moses, Jeffrey W; Mintz, Gary S; Maehara, Akiko

    2015-11-01

    The most common causes of in-stent restenosis (ISR) are intimal hyperplasia and stent under expansion. The purpose of this study was to use intravascular ultrasound (IVUS) to compare the ISR mechanisms of bare metal stents (BMS), first-generation drug-eluting stents (DES), and second-generation DES. There were 298 ISR lesions including 52 BMS, 73 sirolimus-eluting stents, 52 paclitaxel-eluting stents, 16 zotarolimus-eluting stents, and 105 everolimus-eluting stent. Mean patient age was 66.6 ± 1.1 years, 74.2% were men, and 48.3% had diabetes mellitus. BMS restenosis presented later (70.0 ± 66.7 months) with more intimal hyperplasia compared with DES (BMS 58.6 ± 15.5%, first-generation DES 52.6 ± 20.9%, second-generation DES 48.2 ± 22.2%, p = 0.02). Although reference lumen areas were similar in BMS and first- and second-generation DES, restenotic DES were longer (BMS 21.8 ± 13.5 mm, first-generation DES 29.4 ± 16.1 mm, second-generation DES 32.1 ± 18.7 mm, p = 0.003), and stent areas were smaller (BMS 7.2 ± 2.4 mm(2), first-generation DES 6.1 ± 2.1 mm(2), second-generation DES 5.7 ± 2.0 mm(2), p Stent fracture was seen only in DES (first-generation DES 7 [5.0%], second-generation DES 8 [7.4%], p = 0.13). In conclusion, restenotic first- and second-generation DES were characterized by less neointimal hyperplasia, smaller stent areas, longer stent lengths, and more stent fractures than restenotic BMS.

  4. Does intravascular ultrasound provide clinical benefits for percutaneous coronary intervention with bare-metal stent implantation? A meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Lodi-Junqueira Lucas

    2012-09-01

    Full Text Available Abstract Background The role of intravascular ultrasound (IVUS in percutaneous coronary interventions (PCI is still controversial despite several previously published meta-analyses. A meta-analysis to evaluate the controversial role of IVUS-guided PCI with bare-metal stenting was performed and a previous published meta-analysis was re-evaluated in order to clarify the discrepancy between results of these studies. Methods A systematic review was performed by an electronic search of the PubMed, Embase and Web of Knowledge databases and by a manual search of reference lists for randomized controlled trials published until April 2011, with clinical outcomes and, at least, six months of clinical follow-up. A meta-analysis based on the intention to treat was performed with the selected studies. Results Five studies and 1,754 patients were included. There were no differences in death (OR = 1.86; 95% CI = 0.88-3.95; p = 0.10, non-fatal myocardial infarction (OR = 0.65; 95% CI = 0.27-1.58; p = 0.35 and major adverse cardiac events (OR = 0.74; 95% CI = 0.49-1.13; p = 0.16. An analysis of the previous published meta-analysis strongly suggested the presence of publication bias. Conclusions There is no evidence to recommend routine IVUS-guided PCI with bare-metal stent implantation. This may be explained by the paucity and heterogeneity of the studies published so far.

  5. Different edge effects of paclitaxel-and sirolimus-eluting stents on proximal and distal edges in patients with unstable angina:serial intravascular ultrasound analysis

    Institute of Scientific and Technical Information of China (English)

    CHEN Shao-liang; YE Fei; ZHANG Jun-jie; LIU Zhi-zhong; SHAN Shou-jie; SUN Xue-wen; ZHANG Ai-ping; CHEN Jing-guo; XU Ya-wei; YANG Song; CHEN Feng; LUO Weng-ping

    2009-01-01

    Background It is unclear whether edge segments have different responses to paclitaxel eluting stent (PES) and sirolimus eluting stent (SES) implantation in patients with unstable angina. This study aimed to compare the different vascular edge responses in patients with unstable angina and single de novo coronary lesion treated with SES and PES. Methods Two hundred and fifty-five patients with unstable angina and single de novo lesion were randomly assigned to PES and SES groups. Serial volumetric intravascular ultrasound (IVUS) images were taken immediately after stenting and at an eight-month follow-up. Five-mm edge segments proximal and distal to the stents were analyzed. Results Baseline characteristics were comparable between the two groups. At proximal-edge segment, the vessel area decreased and the plaque area increased significantly in the PES group as compared with the SES group. A significant net loss of lumen area was found in the PES group (from (11.10±3.12) mm2 at baseline to (9.92+3.59) mm2 at the follow-up, P <0.001). At the distal-edge segment, the net loss of lumen area in the PES group (from (7.71±2.81) mm2 at baseline to (6.66±2.29) mm2 at the follow-up, P <0.001) was attributed to a significant increase of plaque area. Proximal-edge stenosis was commonly seen in the PES group (20.0%) as compared with the SES group (5.0%, P=0.001). This correlated with the higher incidence of target lesion revascularization in the PES group (P=-0.03). Subsegmentally, the smallest A lumen area was located at 2 mm proximally in both groups, at 0 mm distally in the PES group, and at 1 mm distally in the SES group. Conclusions The two groups demonstrated negative remodeling of edge segments. PES was less effective than SES in inhibiting the growth of plaque within the first 1-mm length proximal to the stent.

  6. PCA-based polling strategy in machine learning framework for coronary artery disease risk assessment in intravascular ultrasound: A link between carotid and coronary grayscale plaque morphology.

    Science.gov (United States)

    Araki, Tadashi; Ikeda, Nobutaka; Shukla, Devarshi; Jain, Pankaj K; Londhe, Narendra D; Shrivastava, Vimal K; Banchhor, Sumit K; Saba, Luca; Nicolaides, Andrew; Shafique, Shoaib; Laird, John R; Suri, Jasjit S

    2016-05-01

    Percutaneous coronary interventional procedures need advance planning prior to stenting or an endarterectomy. Cardiologists use intravascular ultrasound (IVUS) for screening, risk assessment and stratification of coronary artery disease (CAD). We hypothesize that plaque components are vulnerable to rupture due to plaque progression. Currently, there are no standard grayscale IVUS tools for risk assessment of plaque rupture. This paper presents a novel strategy for risk stratification based on plaque morphology embedded with principal component analysis (PCA) for plaque feature dimensionality reduction and dominant feature selection technique. The risk assessment utilizes 56 grayscale coronary features in a machine learning framework while linking information from carotid and coronary plaque burdens due to their common genetic makeup. This system consists of a machine learning paradigm which uses a support vector machine (SVM) combined with PCA for optimal and dominant coronary artery morphological feature extraction. Carotid artery proven intima-media thickness (cIMT) biomarker is adapted as a gold standard during the training phase of the machine learning system. For the performance evaluation, K-fold cross validation protocol is adapted with 20 trials per fold. For choosing the dominant features out of the 56 grayscale features, a polling strategy of PCA is adapted where the original value of the features is unaltered. Different protocols are designed for establishing the stability and reliability criteria of the coronary risk assessment system (cRAS). Using the PCA-based machine learning paradigm and cross-validation protocol, a classification accuracy of 98.43% (AUC 0.98) with K=10 folds using an SVM radial basis function (RBF) kernel was achieved. A reliability index of 97.32% and machine learning stability criteria of 5% were met for the cRAS. This is the first Computer aided design (CADx) system of its kind that is able to demonstrate the ability of coronary

  7. Long-term effects of biodegradable versus durable polymer-coated sirolimus-eluting stents on coronary arterial wall morphology assessed by virtual histology intravascular ultrasound

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-liang; ZHANG Jiao; JIN Zhi-geng; LUO Jian-ping; MA Dong-xing; YANG Sheng-li; LIU Ying; HAN Wei; JING Li-min; MENG Rong-ying

    2011-01-01

    Background The durable presence of polymer coating on drug-eluting stent (DES) surface may be one of the principal reasons for stent thrombosis. The long-term coronary arterial response to biodegradable polymer-coated sirolimus-eluting stent (BSES) in vivo remained unclear.Methods Forty-one patients were enrolled in this study and virtual histology intravascular ultrasound (VH-IVUS) was performed to assess the native artery vascular responses to BSES compared with durable polymer-coated SES (DSES) during long-term follow-up (median: 8 months). The incidence of necrotic core abutting to the lumen was evaluated at follow-up.Results With similar in-stent late luminal loss (0.15 mm (0.06-0.30 mm) vs. 0.19 mm (0.03-0.30 mm), P=0.772), the overall incidence of necrotic core abutting to the lumen was significantly less in BSES group than in DSES group (44% vs.63%, P <0.05) (proximal 18%, stented site 14% and distal 12% in BSES group, proximal 19%, stented site 28% and distal 16% in DSES group). The DSES-treated segments had a significant higher incidence of necrotic core abutting to the lumen through the stent struts (73% vs. 36%, P <0.01). In addition, more multiple necrotic core abutting to the lumen was observed in DSES group (overall: 63% vs. 36%, P <0.05). Furthermore, when the stented segments with necrotic core abutting to the lumen had been taken into account only, DSES-treated lesions tended to contain more multiple necrotic core abutting to the lumen through the stent struts than BSES-treated lesions (74% vs. 33%), although there was no statistically significant difference between them (P=0.06).Conclusions By VH-IVUS analysis at follow-up, a greater frequency of stable lesion morphometry was shown in lesions treated with BSESs compared with lesions treated with DSESs. The major reason was BSES produced less toxicity to the arterial wall and facilitated neointimal healing as a result of polymer coating on DES surface biodegraded as time went by.

  8. Ultrasound image velocimetry for rheological measurements

    Science.gov (United States)

    Gurung, A.; Haverkort, J. W.; Drost, S.; Norder, B.; Westerweel, J.; Poelma, C.

    2016-09-01

    Ultrasound image velocimetry (UIV) allows for the non-intrusive measurement of a wide range of flows without the need for optical transparency. In this study, we used UIV to measure the local velocity field of a model drilling fluid that exhibits yield stress flow behavior. The radial velocity profile was used to determine the yield stress and the Herschel-Bulkley model flow index n and the consistency index k. Reference data were obtained using the conventional offline Couette rheometry. A comparison showed reasonable agreement between the two methods. The discrepancy in model parameters could be attributed to inherent differences between the methods, which cannot be captured by the three-parameter model used. Overall, with a whole flow field measurement technique such as UIV, we were able to quantify the complex rheology of a model drilling fluid. These preliminary results show that UIV can be used as a non-intrusive diagnostic for in situ, real-time measurement of complex opaque flow rheology.

  9. Relationship among soluble CD105,hypersensitive C-reactive protein and coronary plaque morphology:an intravascular ultrasound study

    Institute of Scientific and Technical Information of China (English)

    CUI Song; GE Chang-jiang; LIU Hong; L(U) Shu-zheng; CHEN Yun-dai; HE Guo-xiang; MENG Li-jun; LIU Jian-ping; SONG Zhi-yuan; LIU Xian-liang; SONG Xian-tao

    2008-01-01

    Background Rupture of unstable plaque with subsequent thrombus formation is the common pathophysiological substrate of acute coronary syndrome(ACS).It is of potential significance to explore the blood indexes predicting plaque characteristics.We investigated the relationship among soluble CD105,hypersensitive C-reactive protein(hs-CRP),and coronary plaque morphology.Methods A clinical study from April 2004 to December 2006 was conducted in 130 patients who were divided into 3 groups:56 patients(43.1%)in stable angina(SA)group,52 patients(40.0%)in unstable angina(UA)group and 22 patients(16.9%)in acute myocardial infarction group.The concentrations of soluble CD105 and hs-CRP were measured ln all of the patients by cardioangiography(CAG).Plasma samples of arterial blood were collected prior to the procedure.The levels of soluble CD105 and hs-CRP were measured by enzyme-linked immunosorbent assay (ELISA).Results Unstable and ruptured plaque was found more frequently in patients with acute myocardial infarction and UA.External elastic membrane cross-sectional area(EEM CSA),plaque area,lipid pool area and plaque burden were significantly larger in the ruptured and unstable plaque group.Positive remodeling,thinner fabric-cap,smaller minimal lumen cross-sectional area(MLA),dissection and thrombus were significantly more frequent in the ruptured and unstable plaque group.Remodeling index(RI)was positively correlated with the levels of soluble CD105 in the UA group (r=0.628,P<0.01)and the acute myocardial infarction group(r=0.639,P<0.01).The Ievels of soluble CD105 and hs-CRP were higher in the ruptu red plaque group.Soluble CD105>4.3 ng/ml was used to predict ruptured plaque with a receiver operating characteristic(ROC)curve area of 0.77(95%confidence interval(Cl),66.8%-87.2%),a sensitivity of 72.8%,a specificity of 78.0%and an accuracy of 70.2%(P<0.01),similarly for hs-CRP>5.0 mg/ml with a ROC curve area of 0.70 (95%Cl,59.2%-80.2%),a sensitivity of 70.2%,a

  10. Ultrasound imaging for quantitative measurement of immersed plastic waste particles

    NARCIS (Netherlands)

    Sanaee, S.A.; Bakker, M.C.M.

    2012-01-01

    Ultrasound imaging techniques are proposed for measuring the shape and thickness of immersed waste particles (10-20 mm size) using a linear sensor array from a fixed position. For these purposes both the front and back surface of a particle needs to be reconstructed. Raw ultrasound pulse-echo and pl

  11. Ultrasound field measurement using a binary lens

    CERN Document Server

    Clement, Gregory T; Kamakura, Tomoo

    2014-01-01

    Field characterization methods using a scattering target in the absence of a point-like receiver have been well described in which scattering is recorded by a relatively large receiver located outside the field of measurement. Unfortunately, such methods are prone to artifacts due to averaging across the receiver surface. To avoid this problem while simultaneously increasing the gain of a received signal, the present study introduces a binary plate lens designed to focus spherically-spreading waves onto a planar region having a nearly-uniform phase proportional to that of the target location. The lens is similar to a zone plate, but modified to produce a bi-convex-like behavior, such that it focuses both planar and spherically spreading waves. A measurement device suitable for characterizing narrowband ultrasound signals in air is designed around this lens by coupling it to a target and planar receiver. A prototype device is constructed and used to characterize the field of a highly-focused 400 kHz air transd...

  12. Ultrasound biomicroscopy measurement of skin thickness change induced by cosmetic treatment with ultrasound stimulation.

    Science.gov (United States)

    Mak, Tak-Man; Huang, Yan-Ping; Wang, Li-Ke; Zheng, Yong-Ping

    2014-07-01

    Moisturizing creams and lotions are commonly used in daily life for beauty and treatment of different skin conditions such as dryness and wrinkling, and ultrasound stimulation has been used to enhance the delivery of ingredients into skin. However, there is a lack of convenient methods to study the effect of ultrasound stimulation on lotion absorption by skin in vivo. Ultrasound biomicroscopy was adopted as a viable tool in this study to investigate the effectiveness of ultrasound stimulation on the enhancement of lotion delivery into skin. The forearm skin of 10 male and 10 female young subjects was tested at three different sites, including two lotion treatment sites with (Ultrasound Equipment - UE ON) and without (UE OFF) ultrasound stimulation and a control site without any lotion treatment. 1 MHz ultrasound with a duty cycle of 1.7%, a spatial peak temporal peak pressure of 195 kPa and an average power of 0.43 W was used for the stimulation. The skin thickness before, immediately after (0 min), and 15 and 30 min after the treatment was measured by an ultrasound biomicroscopic system (55 MHz). It was found that the skin thickness significantly increased immediately after the lotion treatment for both UE ON (from 1.379 ± 0.187 mm to 1.466 ± 0.182 mm, pultrasound stimulation was more effective for the female subjects than the male subjects (7.6 ± 2.3% vs. 5.4 ± 2.0% immediately after treatment, p=0.017). In conclusion, this study demonstrated that ultrasound biomicroscopy was a feasible method for studying the effectiveness of lotion treatment in vivo, and ultrasound stimulation was effective to enhance the rate of lotion absorption into skin.

  13. Ultrasound specific similarity measures for three-dimensional mosaicing

    Science.gov (United States)

    Wachinger, Christian; Navab, Nassir

    2008-03-01

    The introduction of 2D array ultrasound transducers enables the instantaneous acquisition of ultrasound volumes in the clinical practice. The next step coming along is the combination of several scans to create compounded volumes that provide an extended field-of-view, so called mosaics. The correct alignment of multiple images, which is a complex task, forms the basis of mosaicing. Especially the simultaneous intensity-based registration has many properties making it a good choice for ultrasound mosaicing in comparison to the pairwise one. Fundamental for each registration approach is a suitable similarity measure. So far, only standard measures like SSD, NNC, CR, and MI were used for mosaicing, which implicitly assume an additive Gaussian distributed noise. For ultrasound images, which are degraded by speckle patterns, alternative noise models based on multiplicative Rayleigh distributed noise were proposed in the field of motion estimation. Setting these models into the maximum likelihood estimation framework, which enables the mathematical modeling of the registration process, led us to ultrasound specific bivariate similarity measures. Subsequently, we used an extension of the maximum likelihood estimation framework, which we developed in a previous work, to also derive multivariate measures. They allow us to perform ultrasound specific simultaneous registration for mosaicing. These measures have a higher potential than afore mentioned standard measures since they are specifically designed to cope with problems arising from the inherent contamination of ultrasound images by speckle patterns. The results of the experiments that we conducted on a typical mosaicing scenario with only partly overlapping images confirm this assumption.

  14. 心肌梗死相关冠状动脉的腔内超声研究%Intravascular ultrasound study of arteries related myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    陈绍良; 徐玲; 段宝祥; 常芸; 刘玲玲

    2000-01-01

    Objective To characterize the lesion in acute myocardial infarction(AMI)-related artery (IRA)by the intravascular ultrasound(IVUS)and angiography image at the culprit site. Methods twenty-five patients with AMI undenwent IVUS study of the IRA immediately following PTCA to the culprit lesion. The IVUS images were analyzed quantitatively and qualitatively and were compared with the angiography. Results ①At the PTCA site, mean area was narrowed down 50%-70% and mean cross-sectional area(CSA) of the plaque was(50±18)% of the arterial CSA;②The atherosclerosis was found in 70% of the proximal and distal segments by IVUS and 30% of these segments by the angiogram(P=0.001);③All the plaques were defined as 69% "Soft" and 31% "hard".The hard plaques were larger than the soft plaques [(50±16)% VS (37±19)% CSA.P=0.01]:④With the increase in plaque area there was a significant increase in arterial ross-sectional area in an the injured segments(r=0.49,P=0.003)as well as in distal and proximal control segments to culprit site.Conclusion IVUS revealed a significant plaque burden at the culprit lesion Of IRA and atherosclerosis in the proximal and distal control segments to the lesion.%目的 比较心肌梗死相关冠状动脉造影和血管内超声下粥样斑块的特征.方法 25例急性心肌梗死患者的梗死相关动脉(IRA)在成功经皮冠状动脉腔内成形术(PTCA)后即刻行冠状动脉内超声检查,结果与冠状动脉造影进行定量和定性比较.结果 ①在PTCA部位,平均面积狭窄50%-70%,斑块横截面积是血管横截面积的(50±18)%;②冠状动脉内超声下病变的近端和远端粥样硬化发生率为70%,而冠状动脉造影下上述部位的病变率仅30%(P=0.001);③69%斑块属于软斑块,硬斑块占31%,但是其斑块面积却大于前者[(50±16)% vs (39±19)%,P=0.01;④PTCA部位所有近端与远端参考段血管腔内斑块面积与血管横截面积之间相关良好(r-0.49,P=0.0001),病变段血管

  15. Accurate monitoring of intravascular fluid volume: A novel application of intrathoracic impedance measures for the guidance of volume reduction therapy

    Directory of Open Access Journals (Sweden)

    Barbara A. Lara

    2015-09-01

    Conclusion: Impedance vectors derived from a multivector monitoring system reflect changes in intravascular plasma volume. Two of these vectors most closely track changes in plasma volume and may be used to more accurately guide and optimize volume reduction therapy.

  16. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    Science.gov (United States)

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  17. Mechanical impedance measurement and damage detection using noncontact laser ultrasound.

    Science.gov (United States)

    Lee, Hyeonseok; Lim, Hyeong Uk; Hong, Jung-Wuk; Sohn, Hoon

    2014-06-01

    This Letter proposes a mechanical impedance (MI) measurement technique using noncontact laser ultrasound. The ultrasound is generated by shooting a pulse laser beam onto a target structure, and its response is measured using a laser vibrometer. Once ultrasound propagation converges to structural vibration, MI is formed over the entire structure. Because noncontact lasers are utilized, this technique is applicable in harsh environments, free of electromagnetic interference, and able to perform wide-range scanning. The formation of MI and its feasibility for damage detection are verified through thermo-mechanical finite element analysis and lab-scale experiments.

  18. Neointimal hyperplasia after sirolimus-eluting and paclitaxel-eluting stent implantation in diabetic patients: the Randomized Diabetes and Drug-Eluting Stent (DiabeDES) Intravascular Ultrasound Trial

    DEFF Research Database (Denmark)

    Jensen, L.O.; Maeng, M.; Thayssen, P.;

    2008-01-01

    AIMS: Patients with diabetes have increased risk of in-stent restenosis after coronary stent implantation owing to neointimal hyperplasia (NIH). The aim of the study was to evaluate the extent and distribution of NIH with intravascular ultrasound (IVUS) after coronary artery stenting with sirolimus......-eluting (Cypher) or paclitaxel-eluting (Taxus) stents in diabetic patients. METHODS AND RESULTS: One hundred and thirty diabetic patients were randomized to Cypher or Taxus stent implantation. IVUS was performed at 8 month follow-up. NIH volume was significantly reduced in the Cypher group when compared...... with the Taxus group: median (inter-quartile range) 0.0 (0.0-0.0) vs. 8.0 mm(3) (0.1-33.0), P stents compared with Taxus stents: median (inter-quartile range) 0.0 (0.0-0.0) vs. 7.5% (0.1-27.0), P stent...

  19. Intimal hyperplasia and vascular remodeling after everolimus-eluting and sirolimus-eluting stent implantation in diabetic patients the randomized diabetes and drug-eluting stent (DiabeDES) IV intravascular ultrasound trial

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Maeng, Michael; Thayssen, Per;

    2013-01-01

    OBJECTIVE: To evaluate the effects of the everolimus-eluting Xience™/Promus™ stent (EES) and the sirolimus-eluting Cypher™ stent (SES) on intimal hyperplasia (IH) in diabetic patients. BACKGROUND: Patients with diabetes mellitus have increased risk of in-stent restenosis after coronary stent...... implantation due to intimal hyperplasia (IH). METHODS: In a sub study of the Randomized Comparison of Everolimus-Eluting and Sirolimus-Eluting Stents in Patients Treated with Percutaneous Coronary Intervention (SORT OUT IV trial), serial intravascular ultrasound (IVUS) 10-month follow-up data were available...... in 88 patients, including 48 EES and 40 SES treated patients. IVUS endpoints included IH volume, in-stent % volume obstruction and changes in external elastic membrane (EEM) volume. RESULTS: Compared with the SES group, IH volume was increased in the EES group [median (interquartile range): 2.8 mm(3) (0...

  20. Two-dimensional ultrasound measurement of thyroid gland volume: a new equation with higher correlation with 3-D ultrasound measurement.

    Science.gov (United States)

    Ying, Michael; Yung, Dennis M C; Ho, Karen K L

    2008-01-01

    This study aimed to develop a new two-dimensional (2-D) ultrasound thyroid volume estimation equation using three-dimensional (3-D) ultrasound as the standard of reference, and to compare the thyroid volume estimation accuracy of the new equation with three previously reported equations. 2-D and 3-D ultrasound examinations of the thyroid gland were performed in 150 subjects with normal serum thyrotropin (TSH, thyroid-stimulating hormone) and free thyroxine (fT4) levels (63 men and 87 women, age range: 17 to 71 y). In each subject, the volume of both thyroid lobes was measured by 3-D ultrasound. On 2-D ultrasound, the craniocaudal (CC), lateromedial (LM) and anteroposterior (AP) dimensions of the thyroid lobes were measured. The equation was derived by correlating the volume of the thyroid lobes measured with 3-D ultrasound and the product of the three dimensions measured with 2-D ultrasound using linear regression analysis, in 75 subjects without thyroid nodule. The accuracy of thyroid volume estimation of the new equation and the three previously reported equations was evaluated and compared in another 75 subjects (without thyroid nodule, n = 30; with thyroid nodule, n = 45). It is suggested that volume of thyroid lobe may be estimated as: volume of thyroid lobe = 0.38.(CC.LM.AP) + 1.76. Result showed that the new equation (16.9% to 36.1%) had a significantly smaller thyroid volume estimation error than the previously reported equations (20.8% to 54.9%) (p thyroid volume estimation error when thyroid glands with nodules were examined (p thyroid volume equation, 2-D ultrasound can be a useful alternative in thyroid volume measurement when 3-D ultrasound is not available.

  1. An intravascular protein osmometer.

    Science.gov (United States)

    Henson, J W; Brace, R A

    1983-05-01

    Our purpose was to develop an intravascular osmometer for measuring the colloid (i.e., protein) osmotic pressure (COP) of circulating blood. A semipermeable hollow fiber from a Cordis Dow artificial kidney (C-DAK 4000) was attached to polyethylene tubing on one end, filled with saline, and sealed at the other end. This was small enough to be inserted into the vasculature of research animals. Protein osmotic pressure plus hydrostatic pressure was measured by a Statham pressure transducer attached to the hollow fiber. Simultaneously, a second catheter and transducer was used to measure hydrostatic pressure, which was subtracted from the pressure measured from the fiber with an on-line computer. The system was documented by a variety of tests. The colloid osmotic pressure vs. albumin concentration curve determined with the fiber is identical to the curve determined by standard membrane osmometry. The time constant for 2- and 8-cm fibers was 2.6 +/- 0.6 and 1.5 +/- 0.5 (+/- SD) min, respectively. The reflection coefficient (+/- SD) of the fiber for NaCl is 0.042 +/- 0.019 (n = 38); COP measured at varying temperatures (absolute scale) changed linearly as expected from COP = nCRT (i.e., van't Hoff's law). Finally, hollow-fiber osmometers were inserted into femoral veins of dogs and sheep, and blood COP was continuously recorded during osmotic manipulations. In conclusion, we attempted to develop and document a simple method for continuous measurement of intravascular colloid osmotic pressure.

  2. Effect of folic acid supplementation on levels of circulating Monocyte Chemoattractant Protein-1 and the presence of intravascular ultrasound derived virtual histology thin-cap fibroatheromas in patients with stable angina pectoris.

    Directory of Open Access Journals (Sweden)

    Kjetil H Løland

    Full Text Available BACKGROUND: Virtual Histology Intravascular Ultrasound (VH-IVUS may be used to detect early signs of unstable coronary artery disease. Monocyte Chemoattractant Protein-1 (MCP-1 is linked with coronary atherosclerosis and plaque instability and could potentially be modified by folic acid treatment. METHODS: In a randomized, prospective study, 102 patients with stable angina pectoris (SAP received percutaneous coronary intervention and established medical treatment as well as either homocysteine-lowering folic acid/vitamin B12 (± B6 or placebo (± B6 for 1 year before VH-IVUS was performed. The presence of VH-Thin-Cap Fibroatheroma (VH-TCFA in non-intervened coronary vessels was registered and serum levels of MCP-1 were measured. The patients were subsequently followed for incident myocardial infarction (MI. RESULTS: Patients treated with folic acid/vitamin B12 had a geometric mean (SD MCP-1 level of 79.95 (1.49 versus 86.00 (1.43 pg/mL for patients receiving placebo (p-value 0.34. VH-TCFA lesions were present in 7.8% of patients and did not differ between intervention arms (p-value 0.47. Serum levels of MCP-1 were 1.46 (95% CI 1.12 to 1.92 times higher in patients with VH-TCFA lesions than in those without (p-value 0.005. Afterwards, patients were followed for median 2.1 years and 3.8% experienced a myocardial infarction (MI, which in post-hoc Cox regression analyses was independently predicted by both MCP-1 (P-value 0.006 and VH-TCFA (p-value 0.01. CONCLUSIONS: In patients with SAP receiving established medical treatment, folic acid supplementation is not associated with either presence of VH-TCFA or levels of MCP-1. MCP-1 is however associated with VH-TCFA, a finding corroborated by increased risk for future MI. ClinicalTrials.gov Identifier: NCT00354081.

  3. Impact of kissing balloon inflation on the main vessel stent volume, area, and symmetry after side-branch dilation in patients with coronary bifurcation lesions: a serial volumetric intravascular ultrasound study.

    Science.gov (United States)

    Rahman, Shahid; Leesar, Tara; Cilingiroglu, Mehmet; Effat, Mohamed; Arif, Imran; Helmy, Tarek; Leesar, Massoud A

    2013-09-01

    Intravascular ultrasound (IVUS) was performed to investigate the impact of kissing balloon inflation (KBI) on the main vessel (MV) stent volume, area, and symmetry after side-branch (SB) dilation in patients with coronary bifurcation lesions (CBL). It remains controversial whether KBI would restore the MV stent area and symmetry loss after SB dilation. A total of 88 serial IVUS examinations of the MV were performed after MV angioplasty, MV stenting, SB dilation, and KBI in 22 patients with CBL. The MV stent was divided into proximal, bifurcation, and distal segments; the stent volume index (SVI), minimal stent area (MSA), stent symmetry index (SSI), and external elastic membrane (EEM) volume index were measured in 198 stent segments and compared after MV stenting, SB dilation, and KBI. In the bifurcation segment, SVI, MSA, and SSI were significantly smaller after SB dilation than after MV stenting and KBI (SVI was 6.10 ± 1.50 mm(3)/mm vs. 6.68 ± 1.60 mm(3)/mm and 6.57 ± 1.60 mm(3)/mm, respectively, p < 0.05; MSA was 5.15 ± 1.30 mm(2) vs. 6.08 ± 1.40 mm(2) and 5.86 ± 1.50 mm(2), respectively, p < 0.05; and SSI was 0.78 ± 0.02 mm(2) vs. 0.87 ± 0.03 mm(2) and 0.84 ± 0.03 mm(2), respectively, p < 0.05). KBI restored the MV SVI, MSA, and SSI after SB dilation. In the proximal segment, SVI, MSA, and EEM volume index were significantly larger, but SSI was smaller after KBI than after MV stenting and SB dilation. In the distal segment, neither SB dilation nor KBI had a significant impact on the MV stent volume or symmetry. This is the first comprehensive volumetric IVUS analysis of CBL, to our knowledge, demonstrating that KBI restores the MV stent volume, area, and symmetry loss after SB dilation in the bifurcation segment, and induces asymmetric stent expansion in the proximal segment. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. Ultrasound

    Science.gov (United States)

    Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and ... liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound ...

  5. Ultrasound as an Outcome Measure in Gout. A Validation Process by the OMERACT Ultrasound Working Group

    DEFF Research Database (Denmark)

    Terslev, Lene; Gutierrez, Marwin; Schmidt, Wolfgang A

    2015-01-01

    OBJECTIVE: To summarize the work performed by the Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Working Group on the validation of US as a potential outcome measure in gout. METHODS: Based on the lack of definitions, highlighted in a recent literature review on US as an outcome tool...

  6. Usefulness of ultrasonographic measurement of the diameter of the inferior vena cava to predict responsiveness to intravascular fluid administration in patients with cancer

    Science.gov (United States)

    Arredondo-Armenta, Juan M.; Guevara-García, Humberto; Barragán-Dessavre, Mireya; García-Guillén, Francisco J.; Sánchez-Hurtado, Luis A.; Córdova-Sánchez, Bertha; Bautista-Ocampo, Andoreni R.; Herrera-Gómez, Angel; Meneses-García, Abelardo

    2016-01-01

    We conducted an observational, longitudinal prospective study in which we measured the diameters of the inferior vena cava (IVC) of 47 patients using ultrasonography. The aim of our study was to assess the state of blood volume and to determine the percentage of patients who responded to intravascular volume expansion. Only 17 patients (36%) responded to fluid management. A higher number of responding patients had cardiovascular failure compared with nonresponders (82% vs. 50%, P = 0.03). Among the patients with cardiovascular failure, the probability of finding responders was 4.6 times higher than that of not finding responders (odds ratio, 4.66; 95% confidence interval, 1.10–19.6; P = 0.04). No significant difference was observed in the mortality rate between the two groups (11% vs. 23%, P = 0.46). In conclusion, responding to intravascular volume expansion had no impact on patient survival in the intensive care unit. PMID:27695165

  7. Clinical workflow for spinal curvature measurement with portable ultrasound

    Science.gov (United States)

    Tabanfar, Reza; Yan, Christina; Kempston, Michael; Borschneck, Daniel; Ungi, Tamas; Fichtinger, Gabor

    2016-03-01

    PURPOSE: Spinal curvature monitoring is essential in making treatment decisions in scoliosis. Monitoring entails radiographic examinations, however repeated ionizing radiation exposure has been shown to increase cancer risk. Ultrasound does not emit ionizing radiation and is safer for spinal curvature monitoring. We investigated a clinical sonography protocol and challenges associated with position-tracked ultrasound in spinal curvature measurement in scoliosis. METHODS: Transverse processes were landmarked along each vertebra using tracked ultrasound snapshots. The transverse process angle was used to determine the orientation of each vertebra. We tested our methodology on five patients in a local pediatric scoliosis clinic, comparing ultrasound to radiographic curvature measurements. RESULTS: Despite strong correlation between radiographic and ultrasound curvature angles in phantom studies, we encountered new challenges in the clinical setting. Our main challenge was differentiating transverse processes from ribs and other structures during landmarking. We observed up to 13° angle variability for a single vertebra and a 9.85° +/- 10.81° difference between ultrasound and radiographic Cobb angles for thoracic curvatures. Additionally, we were unable to visualize anatomical landmarks in the lumbar region where soft tissue depth was 25-35mm. In volunteers with large Cobb angles (greater than 40° thoracic and 60° lumbar), we observed spinal protrusions resulting in incomplete probe-skin contact and partial ultrasound images not suitable for landmarking. CONCLUSION: Spinal curvature measurement using tracked ultrasound is viable on phantom spine models. In the clinic, new challenges were encountered which must be resolved before a universal sonography protocol can be developed.

  8. Comparison of Simulated and Measured Non-linear Ultrasound Fields

    DEFF Research Database (Denmark)

    Du, Yigang; Jensen, Henrik; Jensen, Jørgen Arendt

    2011-01-01

    In this paper results from a non-linear AS (angular spectrum) based ultrasound simulation program are compared to water-tank measurements. A circular concave transducer with a diameter of 1 inch (25.4 mm) is used as the emitting source. The measured pulses are rst compared with the linear...... simulation program Field II, which will be used to generate the source for the AS simulation. The generated non-linear ultrasound eld is measured by a hydrophone in the focal plane. The second harmonic component from the measurement is compared with the AS simulation, which is used to calculate both...

  9. Noninvasive measurement of local thermal diffusivity using backscattered ultrasound and focused ultrasound heating.

    Science.gov (United States)

    Anand, Ajay; Kaczkowski, Peter J

    2008-09-01

    Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create a brief local temperature rise of no more than 10 degrees C. Beamformed radio-frequency (RF) data are collected during heating and cooling using a clinical ultrasound scanner. Measurements of the time-varying "acoustic strain", that is, spatiotemporal variations in the RF echo shifts induced by the temperature related sound speed changes, are related to a solution of the heat transfer equation to estimate the thermal diffusivity in the heated zone. Numerical simulations and experiments performed in vitro in tissue mimicking phantoms and excised turkey breast muscle tissue demonstrate agreement between the ultrasound derived thermal diffusivity estimates and independent estimates made by a traditional hot-wire technique. The new noninvasive ultrasonic method has potential applications in thermal therapy planning and monitoring, physiological monitoring and as a means of noninvasive tissue characterization.

  10. Is the inferior vena cava diameter measured by bedside ultrasonography valuable in estimating the intravascular volume in patients with septic shock?

    Directory of Open Access Journals (Sweden)

    Mortaza Talebi Doluie

    2016-07-01

    Full Text Available Introduction:Resuscitation should be initiated immediately in shock. Early goal-directed therapy is an established algorithm for the resuscitation in septic shock. The first step is to maintain cardiac preload. Central venous pressure (CVP plays an important role in goal-directed therapy. Central venous catheterization is invasive and time-consuming in emergency conditions. There are some alternative and noninvasive methods for estimating the intravascular volume such as measuring the inferior vena cava (IVC diameter by ultrasonography. Methods: We searched PubMed, Google scholar, and Scopus databases with keywords (central venous pressure OR venous pressure OR CVP AND (ultrasonography OR sonography AND (sepsis OR septic shock AND (inferior vena cava OR IVC.Result: The search resulted in 2550 articles. The articles were appraised regarding the relevance, type of article, and statistical methods. Finally, 12 articles were selected. The number of patients was between 30 and 83 cases (mean age=57-67 years, intubated and non-intubated in each study. The IVC diameter was measured in respiratory cycle by bedside ultrasonography in longitudinal subxiphoid view and caval index was calculated, then they were compared with the CVP measured by central venous catheter.Discussion: CVP is an indicator of intravascular fluid status and right heart function. CVP measurement is an invasive method and of course with some complications. The IVC is the biggest vein of venous system with low-pressure; expansion of the vein reflects intravascular volume.Conclusion: It seems that IVC diameter measured by ultrasonography could be used as an alternative method for the determination of CVP in the emergency or critical patients.

  11. Denoising and enhancement in intravascular ultrasound images via multiscale analysis%基于多尺度分析的血管内超声图像去噪和增强

    Institute of Scientific and Technical Information of China (English)

    李虹; 王惠南; 章哓国

    2008-01-01

    提出基于二进小波变换的血管内超声图像血液斑点噪声抑制和对比度增强算法.血液红细胞散射引起的斑点噪声属于乘性噪声,在对数域进行二进小波变换后,结合软阈值滤波法和硬阈值滤波法对不同尺度的小波系数进行萎缩处理,并提出了一种局部阈值估计方法.同时采用了基于多尺度边缘表示的,利用小波系数极值拉伸和Hermite多项式插值实现的快速增强算法.实验结果表明,与现有单独进行去噪处理的方法相比,该方法在抑制血液斑点噪声的同时增强了图像对比度,具有更好的实用性.%An algorithm based on dyadic wavelet transform for speckle reduction and contrast enhancement in intravascular ultrasound images was presented. Wavelet shrinkage techniques which combined soft and hard thresholding were applied to coefficients of logarithmically transformed images since scattering from red blood cells (blood speckle noise) was multiplicative noise and a method to estimate local threshold was proposed. In addition, a fast contrast enhancement algorithm based on multi-scale edges representation of images through stretching the local extrema and interpolating them with Hermite interpolation polynomials was carried out. Experiments with clinical images showed that this algorithm was capable of not only reducing the speckle noise of blood but also enhancing features of diagnostic importance of intravascular ultrasound images and produced superior results qualitatively when compared to results obtained from existing denoising methods alone.

  12. A Novel Model of Atherosclerosis in Rabbits Using Injury to Arterial Walls Induced by Ferric Chloride as Evaluated by Optical Coherence Tomography as well as Intravascular Ultrasound and Histology

    Directory of Open Access Journals (Sweden)

    Jinwei Tian

    2012-01-01

    Full Text Available This study aim was to develop a new model of atherosclerosis by FeCl3-induced injury to right common carotid arteries (CCAs of rabbits. Right CCAs were induced in male New Zealand White rabbits (=15 by combination of a cholesterol-rich diet and FeCl3-induced injury to arterial walls. The right and left CCAs were evaluated by histology and in vivo intravascular ultrasound (IVUS and optical coherence tomography (OCT examinations of 24 hours (=3, 8 weeks (=6, and 12 weeks (=6 after injury. Each right CCA of the rabbits showed extensive white-yellow plaques. At eight and 12 weeks after injury, IVUS, OCT, and histological findings demonstrated that the right CCAs had evident eccentric plaques. Six plaques (50% with evident positive remodeling were observed. Marked progression was clearly observed in the same plaque at 12 weeks after injury when it underwent repeat OCT and IVUS. We demonstrated, for the first time, a novel model of atherosclerosis induced by FeCl3. The model is simple, fast, inexpensive, and reproducible and has a high success rate. The eccentric plaques and remodeling of plaques were common in this model. We successfully carried out IVUS and OCT examinations twice in the same lesion within a relatively long period of time.

  13. Serial intravascular ultrasound analysis of peri-stent remodeling and proximal and distal edge effects after sirolimus-eluting or paclitaxel-eluting stent implantation in patients with diabetes mellitus

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Maeng, Michael; Mintz, Gary S;

    2009-01-01

    Scientific, Maple Grove, Minnesota) stents in diabetic patients. Seventy-four diabetic patients were randomly assigned to Cypher or Taxus stent implantation. Intravascular ultrasound of 5-mm long segments immediately proximal and distal to the stent was performed after the procedure and at the 8-month follow.......1 +/- 85.1 mm(3)), but was unchanged in the Cypher group (153.5 +/- 75.5 to 151.5 +/- 75.8 mm(3); p = 0.002). In proximal and distal reference segments, mean lumen area decreased within the entire 5-mm edge segment (proximal and distal) because of plaque progression (distal, 5.5 +/- 3.6 to 5.8 +/- 3.7 mm(2......); p = 0.097; proximal, 8.1 +/- 2.7 to 8.7 +/- 2.9 mm(2); p = 0.006) without remodeling (change in EEM) in the Taxus group. Conversely, there were no significant changes in reference-segment EEM or plaque areas in the Cypher group. In conclusion, in diabetic patients, Taxus stent implantation...

  14. Intravascular ultrasound guidance to minimize the use of iodine contrast in percutaneous coronary intervention: the MOZART (Minimizing cOntrast utiliZation With IVUS Guidance in coRonary angioplasTy) randomized controlled trial.

    Science.gov (United States)

    Mariani, José; Guedes, Cristiano; Soares, Paulo; Zalc, Silvio; Campos, Carlos M; Lopes, Augusto C; Spadaro, André G; Perin, Marco A; Filho, Antonio Esteves; Takimura, Celso K; Ribeiro, Expedito; Kalil-Filho, Roberto; Edelman, Elazer R; Serruys, Patrick W; Lemos, Pedro A

    2014-11-01

    The aim of this study was to evaluate the impact of intravascular ultrasound (IVUS) guidance on the final volume of contrast agent used in patients undergoing percutaneous coronary intervention (PCI). To date, few approaches have been described to reduce the final dose of contrast agent in PCIs. We hypothesized that IVUS might serve as an alternative imaging tool to angiography in many steps during PCI, thereby reducing the use of iodine contrast. A total of 83 patients were randomized to angiography-guided PCI or IVUS-guided PCI; both groups were treated according to a pre-defined meticulous procedural strategy. The primary endpoint was the total volume contrast agent used during PCI. Patients were followed clinically for an average of 4 months. The median total volume of contrast was 64.5 ml (interquartile range [IQR]: 42.8 to 97.0 ml; minimum, 19 ml; maximum, 170 ml) in the angiography-guided group versus 20.0 ml (IQR: 12.5 to 30.0 ml; minimum, 3 ml; maximum, 54 ml) in the IVUS-guided group (p MOZART]; NCT01947335). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  15. Locally adaptive Nakagami-based ultrasound similarity measures.

    Science.gov (United States)

    Wachinger, Christian; Klein, Tassilo; Navab, Nassir

    2012-04-01

    The derivation of statistically optimal similarity measures for intensity-based registration is possible by modeling the underlying image noise distribution. The parameters of these distributions are, however, commonly set heuristically across all images. In this article, we show that the estimation of the parameters on the present images largely improves the registration, which is a consequence of the more accurate characterization of the image noise. More precisely, instead of having constant parameters over the entire image domain, we estimate them on patches, leading to a local adaptation of the similarity measure. While this basic idea of creating locally adaptive metrics is interesting for various fields of application, we present the derivation for ultrasound imaging. The domain of ultrasound is particularly appealing for this approach, due to the inherent contamination with speckle noise. Furthermore, there exist detailed analyses of suitable noise distributions in the literature. We present experiments for applying a bivariate Nakagami distribution that facilitates modeling of several scattering scenarios prominent in medical ultrasound. Depending on the number of scatterers per resolution cell and the presence of coherent structures, different Nakagami parameters are required to obtain a valid approximation of the intensity statistics and to account for distributional locality. Our registration results on radio-frequency ultrasound data confirm the theoretical necessity for a spatial adaptation of similarity metrics.

  16. Ultrasound settings significantly alter arterial lumen and wall thickness measurements

    Directory of Open Access Journals (Sweden)

    Green Daniel J

    2008-01-01

    Full Text Available Abstract Background Flow-mediated dilation (FMD and carotid intima-medial thickness (CIMT, measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR and gain set at five decibel (dB increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p Conclusion DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects.

  17. Using Ultrasound to Measure Mud Rheological Properties

    Science.gov (United States)

    Maa, P. Y. P. Y.; Kwon, J. I.; Park, K. S.

    2015-12-01

    In order to predict the dynamic responses of newly consolidated cohesive sediment beds, a better understanding of the material rheological properties (bulk density, ρ, kinematic viscosity, ν, and shear modulus, G, assuming mud is a simple Voigt viscoelastic model) of these sediment beds is needed. An acoustic approach that uses a commercially available 250 kHz shear wave transducer and tone-burst waves has been developed to measure those properties. This approach uses a 86.3 mm long delay-line (DL) to separate the generated pressure and shear waves, and measures the reflected shear waves as well as the reflected pressure waves caused at the interface between the delay line and the mud to interpret these properties. By using materials (i.e., air, water, olive oil, and honey) with available rheological properties to establish a calibration relationship between the information carried by the measured reflected waves and those given material properties, the mud properties as well as thνe change of these properties during consolidation can be interpreted. Using jelly pudding as a check, a value of G ≈ 12310 N/m2 and ν ≈ 5 x 10-5 m2/s were estimated. For the consolidating kaolinite bed (with zero salinity and initial suspended sediment concentration about 420 g/cm3), the measurements show that the shear modulus developed after about 40 hours and approached a value on the order of 15000 N/m2 after about 100 hours. The initial kinematic viscosity was about 5 x 10-4 m2/s, and it decreased slowly with time and approached a low plateau between 10-6 and 10-7 m2/s after 300 hours. The measured bulk density showed a small increasing rate during the entire consolidation period, except at a short period between 80 and 90 hours after consolidation. Results from this study suggest a promising approach for developing an in-situ instrument to measure mud properties, as well as many other materials in other industries.

  18. Ultrasound Tomography in Circular Measurement Configuration using Nonlinear Reconstruction Method

    Directory of Open Access Journals (Sweden)

    Tran Quang-Huy

    2015-12-01

    Full Text Available Ultrasound tomography offers the potential for detecting of very small tumors whose sizes are smaller than the wavelength of the incident pressure wave without ionizing radiation. Based on inverse scattering technique, this imaging modality uses some material properties such as sound contrast and attenuation in order to detect small objects. One of the most commonly used methods in ultrasound tomography is the Distorted Born Iterative Method (DBIM. The compressed sensing technique was applied in the DBIM as a promising approach for the image reconstruction quality improvement. Nevertheless, the random measurement configuration of transducers in this method is very difficult to set up in practice. Therefore, in this paper, we take advantages of simpler sparse uniform measurement configuration set-up of transducers and high-quality image reconstruction of 1 non-linear regularization in sparse scattering domain. The simulation results demonstrate the high performance of the proposed approach in terms of tremendously reduced total runtime and normalized error.

  19. Cintilografia do miocárdio com tecnécio 99m-MIBI e administração de adenosina em portadores de doença arterial coronária: correlação dos resultados com a angiografia coronária e o ultra-som intracoronário Adenosine myocardial perfusion SPECT with Tc-99m-MIBI in patients with obstructive coronary artery disease: correlation between quantitative coronary angiography and intravascular ultrasound measurements

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Mastrocolla

    2006-01-01

    Full Text Available OBJETIVO: Estabelecer a correlação da cintilografia de perfusão do miocárdio (CPM com Tecnécio 99m-MIBI (MIBI e injeção de adenosina, empregando a angiografia coronária quantitativa (ACQ e o ultra-som intracoronário (UIC como comparação. MÉTODOS: Estudo de 70 pacientes com doença arterial coronária (DAC, encaminhados à CPM com MIBI e adenosina. As manifestações clínicas, do eletrocardiograma (ECG e os resultados das imagens foram correlacionadas às variáveis da análise visual e quantitativa da angiografia, bem como ao UIC. RESULTADOS: A média de idades foi de 60,6 anos, com 39 pacientes do sexo masculino. A angiografia coronária evidenciou estenose do diâmetro da luz (E% de 49,94% em 105 artérias, com reavaliação à ACQ em 83 artérias (79% e média de 44,20%, pOBJECTIVE: To correlate myocardial perfusion scintigraphy (MPS with Tc-99m-MIBI and adenosine infusion using quantitative coronary angiography (QCA and intravascular ultrasound (IVUS. METHODS: Seventy patients with coronary artery disease (CAD referred for myocardial perfusion scintigraphy (MPS with MIBI and adenosine were studied. Clinical, electrocardiographic (ECG, and scintigraphic findings were correlated with variables of visual and quantitative angiographic analysis, as well as to those of IVUS. RESULTS: The mean age of patients was 60.6 years, and 39 were male. Coronary angiography showed percentage of diameter stenosis (% DS of 49.94% in 105 arteries, 83 of which were re-evaluated by QCA (79%, mean of 44.20%, p<0.05. ST-segment depression during adenosine infusion was associated with higher degrees of % DS (55.0% vs. 47.8%, p<0.05. Scintigraphic ischemia was correlated with greater cross-sectional area of lumen obstruction by IVUS (% CSA. Clinical, ECG, and IVUS findings were considered together and expressed as global ischemic versus non-ischemic responses. Ischemia was associated with lower values of minimal lumen diameter (MLD and minimal lumen area

  20. Quantitative Measurements using Ultrasound Vector Flow Imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2016-01-01

    Duplex Vector Flow Imaging (VFI) imaging is introduced as a replacement for spectral Doppler, as it automatically can yield fully quantitative flow estimates without angle correction. Continuous VFI data over 9 s for 10 pulse cycles were acquired by a 3 MHz convex probe connected to the SARUS......L/stroke (true: 1.15 mL/stroke, bias: 12.2%). Measurements down to 160 mm were obtained with a relative standard deviation and bias of less than 10% for the lateral component for stationary, parabolic flow. The method can, thus, find quantitative velocities, angles, and volume flows at sites currently...

  1. Disseminated intravascular coagulation (DIC)

    Science.gov (United States)

    ... Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 141. Thachil J, Toh CH. Current concepts in the management of disseminated intravascular coagulation. Thromb Res . 2012;129 ...

  2. Methods for blood flow measurements using ultrasound contrast agents

    Science.gov (United States)

    Fowlkes, J. Brian

    2003-10-01

    Blood flow measurements using ultrasound contrast agents are being investigated for myocardial perfusion and more recently in other organ systems. The methods are based largely on the relative increase in echogenicity due to the concentration of bubbles present in the ultrasound beam. In the simplest form, regional differences in blood volume can be inferred but the possibility exists to extract perfusion from the transit of contrast agent through tissue. Perfusion measurements rely on determining the flux of blood through a tissue volume and as such require knowledge of the fractional blood volume (FBV), i.e., ml blood/g tissue and the rate of exchange, commonly measured as the mean transit time (MTT). This presentation will discuss methods of determining each of these values and their combination to estimate tissue perfusion. Underlying principles of indicator-dilution theory will be provided in the context of ultrasound contrast agents. Current methods for determining MTT will include imaging of the intravenous bolus, in-plane contrast disruption with interval and real-time contrast recovery imaging, and control of contrast agent flow using arterial disruption (contrast interruption). The advantages and limitations of the methods will be examined along with current applications. [Work supported in part by NIH.

  3. Intravascular malignant lymphomatosis

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Duverneuil, N.; Lafitte, F.; Chiras, J. [Service de Neuroradiologie Charcot, Batiment Babinski, Hopital de la Salpetriere, 75013 Paris (France); Mokhtari, K. [Service de Neuropathologie, Hopital de la Salpetriere, 75013 Paris (France); Behin, A.; Hoang-Xuan, K. [Departement de Neurologie, Hopital de la Salpetriere, 75013 Paris (France)

    2002-09-01

    Intravascular malignant lymphomatosis is a rare and probably often overlooked disease characterised by massive intravascular proliferation of lymphoid cells, usually with a poor prognosis. CT and MRI appearances are nonspecific; the most suggestive finding being both asymmetrical, bilateral, contrast enhancing high-signal areas on T2 weighting and infarct-like lesions of the cortex and basal ganglia. We report two patients with previously unreported dural and spinal cord involvement. (orig.)

  4. Blood flow measurements during hemodialysis vascular access interventions - Catheter-based thermodilution or Doppler ultrasound?

    DEFF Research Database (Denmark)

    Heerwagen, Søren T; Hansen, Marc A; Schroeder, Torben V

    2012-01-01

    Purpose: To test the clinical performance of catheter-based thermodilution and Doppler ultrasound of the feeding brachial artery for blood flow measurements during hemodialysis vascular access interventions.Methods: Thirty patients with arteriovenous fistulas who underwent 46 interventions had...... access blood flow measured before and after every procedure. Two methods, catheter-based thermodilution and Doppler ultrasound, were compared to the reference method of ultrasound dilution. Catheter-based thermodilution and Doppler ultrasound were performed during the endovascular procedures while flow...

  5. The use of gel dosimetry to measure the 3D dose distribution of a 90Sr/90Y intravascular brachytherapy seed.

    Science.gov (United States)

    Massillon-Jl, G; Minniti, R; Mitch, M G; Maryanski, M J; Soares, C G

    2009-03-21

    Absorbed dose distributions in 3D imparted by a single (90)Sr/(90)Y beta particle seed source of the type used for intravascular brachytherapy were investigated. A polymer gel dosimetry medium was used as a dosemeter and phantom, while a special high-resolution laser CT scanner with a spatial resolution of 100 microm in all dimensions was used to quantify the data. We have measured the radial dose function, g(L)(r), observing that g(L)(r) increases to a maximum value and then decreases as the distance from the seed increases. This is in good agreement with previous data obtained with radiochromic film and thermoluminescent dosemeters (TLDs), even if the TLDs underestimate the dose at distances very close to the seed. Contrary to the measurements, g(L)(r) calculated through Monte Carlo simulations and reported previously steadily decreases without a local maximum as a function of the distance from the seed. At distances less than 1.5 mm, differences of more than 20% are observed between the measurements and the Monte Carlo calculations. This difference could be due to a possible underestimation of the energy absorbed into the seed core and encapsulation in the Monte Carlo simulation, as a consequence of the unknown precise chemical composition of the core and its respective density for this seed. The results suggest that g(L)(r) can be measured very close to the seed with a relative uncertainty of about 1% to 2%. The dose distribution is isotropic only at distances greater than or equal to 2 mm from the seed and is almost symmetric, independent of the depth. This study indicates that polymer gel coupled with the special small format laser CT scanner are valid and accurate methods for measuring the dose distribution at distances close to an intravascular brachytherapy seed.

  6. The use of gel dosimetry to measure the 3D dose distribution of a {sup 90}Sr/{sup 90}Y intravascular brachytherapy seed

    Energy Technology Data Exchange (ETDEWEB)

    Massillon-JL, G; Minniti, R; Mitch, M G; Soares, C G [Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Maryanski, M J [MGS Research, Inc., Madison, CT 06443 (United States)], E-mail: massillon@fisica.unam.mx

    2009-03-21

    Absorbed dose distributions in 3D imparted by a single {sup 90}Sr/{sup 90}Y beta particle seed source of the type used for intravascular brachytherapy were investigated. A polymer gel dosimetry medium was used as a dosemeter and phantom, while a special high-resolution laser CT scanner with a spatial resolution of 100 {mu}m in all dimensions was used to quantify the data. We have measured the radial dose function, g{sub L}(r), observing that g{sub L}(r) increases to a maximum value and then decreases as the distance from the seed increases. This is in good agreement with previous data obtained with radiochromic film and thermoluminescent dosemeters (TLDs), even if the TLDs underestimate the dose at distances very close to the seed. Contrary to the measurements, g{sub L}(r) calculated through Monte Carlo simulations and reported previously steadily decreases without a local maximum as a function of the distance from the seed. At distances less than 1.5 mm, differences of more than 20% are observed between the measurements and the Monte Carlo calculations. This difference could be due to a possible underestimation of the energy absorbed into the seed core and encapsulation in the Monte Carlo simulation, as a consequence of the unknown precise chemical composition of the core and its respective density for this seed. The results suggest that g{sub L}(r) can be measured very close to the seed with a relative uncertainty of about 1% to 2%. The dose distribution is isotropic only at distances greater than or equal to 2 mm from the seed and is almost symmetric, independent of the depth. This study indicates that polymer gel coupled with the special small format laser CT scanner are valid and accurate methods for measuring the dose distribution at distances close to an intravascular brachytherapy seed.

  7. Ultrasound measurements of the masseter muscle as predictors of cephalometric indices in orthodontics: a pilot study.

    Science.gov (United States)

    Naser-Ud-Din, S; Sampson, W J; Dreyer, C W; Thoirs, K

    2010-09-01

    This study investigated the potential of ultrasound measurements of the masseter muscle to accurately predict indices normally derived from cephalograms. Masseter muscle measurements on 11 adults (22 to 30 y) were made using lateral cephalometrics and extended field-of-view ultrasound. The ultrasound technique was validated in a simulation pilot study using 12 dry skulls and raw chicken breasts. Twenty cephalometric variables were analyzed against four ultrasound measurements of the masseter muscle. Highly significant correlations (r = 0.81-0.85, p = 0.001-0.002) between ultrasound measurements of the masseter muscle and cephalometric measurements representing the length of the superficial masseter muscle, the length and shape of the mandible and vertical facial proportions were demonstrated. Predictive equations from regression analyses were constructed to deduce ramus length and shape from the ultrasound measurements. The results provide pilot data suggesting that ultrasound is a potential clinical tool for sequential evaluation of masseter muscle length in orthodontics and facial muscle growth studies.

  8. Three Dimensional Segmentation of Intravascular Ultrasound Image Sequence Based on Fast Marching%基于快速推进法的血管内超声图像序列的三维分割

    Institute of Scientific and Technical Information of China (English)

    杨宇

    2011-01-01

    目的 血管内超声(intravascular ultrasound,IVUS)是近年来临床诊断血管病变的一项新技术.对IVUS图像进行分割,提取出图像中血管壁的内膜和中-外膜轮廓,是IVUS图像序列定量分析和三维重建的重要步骤.方法 本文提出一种基于快速推进法的IVUS图像序列三维并行分割方法.在完成对原始图像的滤波去噪、抑制导管伪影等预处理后,获取IVUS序列纵向视图,并从中提取出血管壁的内膜和中 -外膜轮廓,然后将该轮廓映射到每帧IVUS横向视图中,得到各IVUS帧中血管壁的内膜和中-外膜轮廓,最后采用快速推进法对初始轮廓进行演化变形,最终提取出目标轮廓.结果 对临床IVUS图像数据进行实验,与逐帧处理的串行分割方法相比,本文方法明显提高了处理效率,克服了传统串行处理方法运算效率低的缺点.结论 该方法对血管疾病的临床诊治具有重要意义.%Objective Intravascular ultrasound (IV US) is used in clinical diagnosis of vascular disease as a new technology in recent years. The detection of vascular wall from IV US image to get the intima contour and the media - adventitia contour of vessel wall is an important step in quantitative analysis and three -dimensional reconstruction of IVUS image sequence. Methods We proposed a three dimensional parallel segmentation of IVUS image sequence based on fast marching method. After the pretreatments of original images, such as filtering, smoothing and suppression of ring - down artifacts, IVUS longitudinal cut was obtained and its detected vessel wall contours were mapped into each cross - sectional slice to obtain initial vessel wall contours in each IVUS frame. Finally, with the fast marching algorithm, initial contours deformed until stopping at the actual contours. Results The data of the experiment on clinical IV US image showed that this method greatly improved the efficiency and overcame the shortcomings of the traditional

  9. Ultrasound

    Science.gov (United States)

    ... Saunders; 2014:chap 66. Cosgrove DO, Eckersley RJ, Harvey CJ, Lim A. Ultrasound. In: Adam A, Dixon AK, Gillard ... Northside Radiology Associates, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  10. Angiographic and clinical comparisons of intravascular ultrasound- versus angiography-guided drug-eluting stent implantation for patients with chronic total occlusion lesions: two-year results from a randomised AIR-CTO study.

    Science.gov (United States)

    Tian, Nai-Liang; Gami, Sandeep-Kumar; Ye, Fei; Zhang, Jun-Jie; Liu, Zhi-Zhong; Lin, Song; Ge, Zhen; Shan, Shou-Jie; You, Wei; Chen, Liang; Zhang, Yao-Jun; Mintz, Gary; Chen, Shao-Liang

    2015-04-01

    This study sought to compare angiographic endpoints at one-year follow-up after a drug-eluting stent implantation guided by either intravascular ultrasound (IVUS) or angiography in patients with chronic total occlusion (CTO) lesions. Patients with at least one CTO lesion recanalised successfully were randomly assigned to the IVUS-guided or the angiography-guided group. The use of IVUS for penetration of the true lumen and optimisation of stent expansion was only done in the IVUS-guided group. The primary endpoint was in-stent late lumen loss (LLL) at one-year follow-up. A total of 230 patients with CTO lesions after successful recanalisation were enrolled and followed with office visits or telephone contact up to 24 months. In-stent LLL in the IVUS-guided group was significantly lower compared to the angiography-guided group at one-year follow-up (0.28±0.48 mm vs. 0.46±0.68 mm, p=0.025), with a significant difference in restenosis of the "in-true-lumen" stent between the two groups (3.9% vs.13.7%, p=0.021). The minimal lumen diameter and minimal stent cross-section area significantly and negatively correlated with LLL (all pCTO lesion was associated with less LLL and a lower incidence of "in-true-lumen" stent restenosis. Additional study is required to identify the clinical benefit of the IVUS-guided procedure for CTO lesions. [ChiCTR-TRC-10000996].

  11. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, E F; Strandberg, C; Bendtsen, F

    1999-01-01

    BACKGROUND: Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler with that of tran......BACKGROUND: Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler...... with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated. METHODS: Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA...... echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug...

  12. Validation of a novel ultrasound measurement of achilles tendon length

    DEFF Research Database (Denmark)

    Barfod, Kristoffer Weisskirchner; Riecke, Anja Falk; Boesen, Anders

    2014-01-01

    PURPOSE: A clinically applicable and accurate method for measuring Achilles tendon length is needed to investigate the influence of elongation of the Achilles tendon after acute rupture. The purpose of this study was to develop and validate an ultrasonographic (US) length measurement...... of the Achilles tendon-aponeurosis complex. METHODS: Both legs of 19 non-injured subjects were examined by magnetic resonance imaging (MRI) and US. The length from calcaneus to the medial head of m. Gastrocnemius was measured by three independent US examiners. Repeated US measurements were performed and compared...... to be further assessed in the setting of acute Achilles tendon rupture. CLINICAL RELEVANCE: This new ultrasound measurement might allow for length measurement of ruptured Achilles tendons in the acute and chronic state after rupture. LEVEL OF EVIDENCE: II....

  13. Ultrasound attenuation as a quantitative measure of fracture healing

    Science.gov (United States)

    Gheduzzi, Sabina; Humphrey, Victor F.; Dodd, Simon P.; Cunningham, James L.; Miles, Anthony W.

    2004-10-01

    The monitoring of fracture healing still relies upon the judgment of callus formation and on the manual assessment of the stiffness of the fracture. A diagnostic tool capable of quantitatively measuring healing progression of a fracture would allow the fine-tuning of the treatment regime. Ultrasound attenuation measurements were adopted as a possible method of assessing the healing process in human long bones. The method involves exciting ultrasonic waves at 200 kHz in the bone and measuring the reradiation along the bone and across the fracture zone. Seven cadaveric femora were tested in vitro in intact form and after creating a transverse fracture by sawing through the cortex. The effects of five different fracture types were investigated. A partial fracture, corresponding to a 50% cut through the cortex, a closed fracture, and fractures of widths varying between 1, 2, and 4 mm were investigated. The introduction of a fracture was found to produce a dramatic effect on the amplitude of the signal. Ultrasound attenuation was found to be sensitive to the presence of a fracture, even when the fracture was well reduced. It would therefore appear feasible to adopt attenuation across a fracture as a quantitative measurement of fracture healing.

  14. Brachytherapy optimal planning with application to intravascular radiation therapy

    DEFF Research Database (Denmark)

    Sadegh, Payman; Mourtada, Firas A.; Taylor, Russell H.;

    1999-01-01

    . Dose rate calculations are based on the sosimetry formulation of the American Association of Physicists in Medicine, Task Group 43. We apply the technique to optimal planning for intravascular brachytherapy of intimal hyperplasia using ultrasound data and 192Ir seeds. The planning includes...

  15. Concentration measurement of yeast suspensions using high frequency ultrasound backscattering.

    Science.gov (United States)

    Elvira, Luis; Vera, Pedro; Cañadas, Francisco Jesús; Shukla, Shiva Kant; Montero, Francisco

    2016-01-01

    This work proposes the use of an ultrasound based technique to measure the concentration of yeasts in liquid suspension. This measurement was achieved by the detection and quantification of ultrasonic echoes backscattered by the cells. More specifically, the technique was applied to the detection and quantification of Saccharomyces cerevisiae. A theoretical approach was proposed to get the average density and sound speed of the yeasts, which were found to be 1116 kg/m(3) and 1679 m/s, respectively. These parameters were needed to model the waves backscattered by each single cell. A pulse-echo arrangement working around 50 MHz, being able to detect echoes from single yeasts was used to characterize experimentally yeast solutions from 10(2) to 10(7)cells/ml. The Non-negative Matrix Factorization denoising technique was applied for data analysis. This technique required a previous learning of the spectral patterns of the echoes reflected from yeasts in solution and the base noise from the liquid medium. Comparison between pulse correlation (without denoising) and theoretical and experimental pattern learning was made to select the best signal processing. A linear relation between ultrasound output and concentration was obtained with correlation coefficient R(2)=0.996 for the experimental learning. Concentrations from 10(4) to 10(7)cells/ml were detected above the base noise. These results show the viability of using the ultrasound backscattering technique to detect yeasts and measure their concentration in liquid cultures, improving the sensitivity obtained using spectrophotometric methods by one order of magnitude.

  16. Equipment, measurement and dose—a survey for therapeutic ultrasound

    OpenAIRE

    2016-01-01

    Background Dosimetry for Ultrasound Therapy (DUTy) is a large international project which addresses the development of a metrological infrastructure for the determination of ultrasound exposure and dose to tissue. Methods In order to seek the views of the wider therapy ultrasound community and to review dose and in situ exposure quantities that have been suggested or used previously, a web-based questionnaire containing a range of questions covering the type of ultrasound equipment that is us...

  17. Assessment of performance measures and learning curves for use of a virtual-reality ultrasound simulator in transvaginal ultrasound examination

    DEFF Research Database (Denmark)

    Madsen, M E; Konge, L; Nørgaard, L N

    2014-01-01

    OBJECTIVE: To assess the validity and reliability of performance measures, develop credible performance standards and explore learning curves for a virtual-reality simulator designed for transvaginal gynecological ultrasound examination. METHODS: A group of 16 ultrasound novices, along with a group......-6), corresponding to an average of 219 min (range, 150-251 min) of training. The test/retest reliability was high, with an intraclass correlation coefficient of 0.93. CONCLUSIONS: Competence in the performance of gynecological ultrasound examination can be assessed in a valid and reliable way using virtual-reality...... of 12 obstetrics/gynecology (Ob/Gyn) consultants, were included in this experimental study. The first two performances of the two groups on seven selected modules on a high-fidelity ultrasound simulator were used to identify valid and reliable metrics. Performance standards were determined and novices...

  18. NONINVASIVE MEASUREMENT OF LOCAL THERMAL DIFFUSIVITY USING BACKSCATTERED ULTRASOUND AND FOCUSED ULTRASOUND HEATING

    OpenAIRE

    2008-01-01

    Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create...

  19. Agreement between anatomic and ultrasound measurements of femoral trochlear depth

    DEFF Research Database (Denmark)

    Miles, James Edward; Westrup, Ulrik; Eriksen, Thomas

    over the five regions examined. Measurement reliability for the ultrasonographic examinations was markedly less that for the skyline views (repeatability coefficient of 0.5mm vs 0.25mm), but still adequate for clinical use. A likely reason is the relative amount of detail recorded in the respective...... and ultrasonographic measurements of trochlear depth using the red fox hind limb as a canine surrogate, dividing the trochlea into five regions from the origin of the caudal cruciate ligament to the proximal aspect of the trochlea. We found reasonable agreement between anatomic and ultrasonographic measurements...... as assessed by Bland-Altman difference charting and limits of agreement (approximately ±0.7mm). Differences may be accounted for by ultrasound probe positioning errors, which should be taken into consideration during clinical investigations. Skyline views were difficult to standardise to a distinct position...

  20. Clinical expert consensus document on standards for acquisition, measurement and reporting of intravascular ultrasound regression/progression studies

    NARCIS (Netherlands)

    G.S. Mintz (Gary); H.M. Garcia-Garcia (Hector); S.J. Nicholls (Stephen); N.J. Weissman (Neil); N. Bruining (Nico); S. Crowe (Suzanne); J.-C. Tardif (Jean-Claude); P.W.J.C. Serruys (Patrick)

    2011-01-01

    textabstractAtherosclerotic cardiovascular disease is a leading cause of morbidity and mortality despite the widespread use of established medical therapies. This has prompted the search to identify new therapeutic approaches to achieve more effective prevention of cardiovascular events. Considerabl

  1. Clinical expert consensus document on standards for acquisition, measurement and reporting of intravascular ultrasound regression/progression studies

    NARCIS (Netherlands)

    G.S. Mintz (Gary); H.M. Garcia-Garcia (Hector); S.J. Nicholls (Stephen); N.J. Weissman (Neil); N. Bruining (Nico); S. Crowe (Suzanne); J.-C. Tardif (Jean-Claude); P.W.J.C. Serruys (Patrick)

    2011-01-01

    textabstractAtherosclerotic cardiovascular disease is a leading cause of morbidity and mortality despite the widespread use of established medical therapies. This has prompted the search to identify new therapeutic approaches to achieve more effective prevention of cardiovascular events. Considerabl

  2. Intravascular lymphoma mimicking vasculitis.

    Science.gov (United States)

    Prayson, Richard A

    2016-12-01

    Intravascular lymphoma is a rare malignancy which is characterized by a proliferation of atypical appearing B cells, generally confined to vascular lumina. A tissue biopsy demonstrating the pathology is required to make a diagnosis. The tumor is often disseminated at the time of diagnosis and prognosis is poor, even with aggressive chemotherapy. Neurologic presentations of this neoplasm can be quite varied. This report documents the presence of intravascular lymphoma diagnosed on a brain biopsy in a 60-year-old man. He initially presented 6months before brain biopsy with chest pain and hypotension, warranting coronary artery bypass graft surgery. Four months later, he presented with signs attributed to a stroke (diaphoresis, slumped over in a chair and left hand weakness). He subsequently developed a sudden onset wide-based gait, left leg numbness, word finding difficulties and worsening confusion. A MRI study showed multiple infarcts in the brain, including cerebellum. Invasive angiogram suggested vasculitis. He was started on a course of treatment for presumed central nervous system vasculitis. He continued to develop signs suggestive of ongoing infarct development and a biopsy from the right parietal was taken. The biopsy showed atypical intravascular CD20 positive staining B cells, consistent with intravascular lymphoma. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Intra-stent tissue evaluation within bare metal and drug-eluting stents > 3 years since implantation in patients with mild to moderate neointimal proliferation using optical coherence tomography and virtual histology intravascular ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Kitabata, Hironori; Loh, Joshua P.; Pendyala, Lakshmana K.; Omar, Alfazir; Ota, Hideaki; Minha, Sa’ar; Magalhaes, Marco A.; Torguson, Rebecca; Chen, Fang; Satler, Lowell F.; Pichard, Augusto D.; Waksman, Ron, E-mail: ron.waksman@medstar.net

    2014-04-15

    Objective: We aimed to compare neointimal tissue characteristics between bare-metal stents (BMS) and drug-eluting stents (DES) at long-term follow-up using optical coherence tomography (OCT) and virtual histology intravascular ultrasound (VH-IVUS). Background: Neoatherosclerosis in neointima has been reported in BMS and in DES. Methods: Thirty patients with 36 stented lesions [BMS (n = 17) or DES (n = 19)] > 3 years after implantation were prospectively enrolled. OCT and VH-IVUS were performed and analyzed independently. Stents with ≥ 70% diameter stenosis were excluded. Results: The median duration from implantation was 126.0 months in the BMS group and 60.0 months in the DES group (p < 0.001). Lipid-laden intima (58.8% vs. 42.1%, p = 0.317), thrombus (17.6% vs. 5.3%, p = 0.326), and calcification (35.3% vs. 26.3%, p = 0.559) did not show significant differences between BMS and DES. When divided into 3 time periods, the cumulative incidence of lipid-laden neointima from > 3 years to < 9 years was similar between BMS and DES (42.9% vs. 42.1%, p = 1.000). Furthermore, it continued to gradually increase over time in both groups. OCT-derived thin-cap fibroatheroma (TCFA) was observed in 17.6% of BMS- and 5.3% of DES-treated lesions (p = 0.326). No stents had evidence of intimal disruption. The percentage volume of necrotic core (16.1% [9.7, 20.3] vs. 9.7% [7.0, 16.5], p = 0.062) and dense calcium (9.5% [3.8, 13.6] vs. 2.7% [0.4, 4.9], p = 0.080) in neointima tended to be greater in BMS-treated lesions. Intra-stent VH-TCFA (BMS vs. DES 45.5% vs. 18.2%, p = 0.361) did not differ significantly. Conclusion: At long-term follow-up beyond 3 years after implantation, the intra-stent neointimal tissue characteristics appeared similar for both BMS and DES.

  4. Ultrasound measurements of intraabdominal fat estimate the metabolic syndrome better than do measurements of waist circumference

    NARCIS (Netherlands)

    Stolk, RP; Meijer, Rudy; Mali, WPTM; Grobbee, DE; van der Graaf, Y

    2003-01-01

    Background: We recently developed an ultrasound technique to estimate intraabdominal fat (IAF). This method is more accurate than measurement of waist and hip circumferences and is simpler and less expensive than computed tomography or magnetic resonance imaging. Objective: We compared the associati

  5. Non-Invasive Measurement of Pulsatile Intracranial Pressures Using Ultrasound

    Science.gov (United States)

    Ueno, Toshiaki; Ballard, Richard E.; Shuer, Lawrence M.; Cantrell, John H.; Cantrell, John H.; Hargens, Alan R.

    1997-01-01

    Early detection of elevated intracranial pressure (ICP) will aid clinical decision-making for head trauma, brain tumor and other cerebrovascular diseases. Conventional methods, however, require surgical procedures which take time and are accompanied by increased risk of infection. Accordingly we have developed and refined a new ultrasound device to measure skull movements which are known to occur in conjunction with altered ICP. The principle of this device is based upon pulse phase locked loop (PPLL), which enables us to detect changes in distance on the order of microns between an ultrasound transducer on one side of the skull and the opposite inner surface of the cranium. The present study was designed to verify this measurement technique in cadavera. Transcranial distance was increased in steps of 10 mmHg from zero to 50 mmHg by saline infusion into the lateral ventricle of two cadavera. In separate experiments, pulsations of ICP with the amplitudes of zero to 2 mmHg were generated by rhythmic injections of saline using a syringe. When the ICP was stepwise increased from zero to 50 mmHg, transcranial distance increased in proportion with the ICP increase (y=12 x - 76, r=0.938), where y is changes in transcranial distance in microns and x is ICP in mmHg. In the data recorded while ICP pulsations were generated, fast Fourier transform analysis demonstrated that cranial pulsations were clearly associated with ICP pulsations. The results indicate that changes in transcranial distance is linearly correlated with those in ICP, and also that the PPLL device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. By analyzing the magnitude of cranial pulsations, we may be able to estimate the pressure-volume index in the cranium. As a result, estimates of intracranial compliance may be possible by using the PPLL device. Further studies are necessary in normal subjects and patients.

  6. Non-Invasive Measurement of Pulsatile Intracranial Pressures Using Ultrasound

    Science.gov (United States)

    Ueno, Toshiaki; Ballard, Richard E.; Shuer, Lawrence M.; Cantrell, John H.; Cantrell, John H.; Hargens, Alan R.

    1997-01-01

    Early detection of elevated intracranial pressure (ICP) will aid clinical decision-making for head trauma, brain tumor and other cerebrovascular diseases. Conventional methods, however, require surgical procedures which take time and are accompanied by increased risk of infection. Accordingly we have developed and refined a new ultrasound device to measure skull movements which are known to occur in conjunction with altered ICP. The principle of this device is based upon pulse phase locked loop (PPLL), which enables us to detect changes in distance on the order of microns between an ultrasound transducer on one side of the skull and the opposite inner surface of the cranium. The present study was designed to verify this measurement technique in cadavera. Transcranial distance was increased in steps of 10 mmHg from zero to 50 mmHg by saline infusion into the lateral ventricle of two cadavera. In separate experiments, pulsations of ICP with the amplitudes of zero to 2 mmHg were generated by rhythmic injections of saline using a syringe. When the ICP was stepwise increased from zero to 50 mmHg, transcranial distance increased in proportion with the ICP increase (y=12 x - 76, r=0.938), where y is changes in transcranial distance in microns and x is ICP in mmHg. In the data recorded while ICP pulsations were generated, fast Fourier transform analysis demonstrated that cranial pulsations were clearly associated with ICP pulsations. The results indicate that changes in transcranial distance is linearly correlated with those in ICP, and also that the PPLL device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. By analyzing the magnitude of cranial pulsations, we may be able to estimate the pressure-volume index in the cranium. As a result, estimates of intracranial compliance may be possible by using the PPLL device. Further studies are necessary in normal subjects and patients.

  7. Ability of combined Near-Infrared Spectroscopy-Intravascular Ultrasound (NIRS-IVUS) imaging to detect lipid core plaques and estimate cap thickness in human autopsy coronary arteries

    Science.gov (United States)

    Grainger, S. J.; Su, J. L.; Greiner, C. A.; Saybolt, M. D.; Wilensky, R. L.; Raichlen, J. S.; Madden, S. P.; Muller, J. E.

    2016-03-01

    The ability to determine plaque cap thickness during catheterization is thought to be of clinical importance for plaque vulnerability assessment. While methods to compositionally assess cap integrity are in development, a method utilizing currently available tools to measure cap thickness is highly desirable. NIRS-IVUS is a commercially available dual imaging method in current clinical use that may provide cap thickness information to the skilled reader; however, this is as yet unproven. Ten autopsy hearts (n=15 arterial segments) were scanned with the multimodality NIRS-IVUS catheter (TVC Imaging System, Infraredx, Inc.) to identify lipid core plaques (LCPs). Skilled readers made predictions of cap thickness over regions of chemogram LCP, using NIRS-IVUS. Artery segments were perfusion fixed and cut into 2 mm serial blocks. Thin sections stained with Movat's pentachrome were analyzed for cap thickness at LCP regions. Block level predictions were compared to histology, as classified by a blinded pathologist. Within 15 arterial segments, 117 chemogram blocks were found by NIRS to contain LCP. Utilizing NIRSIVUS, chemogram blocks were divided into 4 categories: thin capped fibroatheromas (TCFA), thick capped fibroatheromas (ThCFA), pathological intimal thickening (PIT)/lipid pool (no defined cap), and calcified/unable to determine cap thickness. Sensitivities/specificities for thin cap fibroatheromas, thick cap fibroatheromas, and PIT/lipid pools were 0.54/0.99, 0.68/0.88, and 0.80/0.97, respectively. The overall accuracy rate was 70.1% (including 22 blocks unable to predict, p = 0.075). In the absence of calcium, NIRS-IVUS imaging provided predictions of cap thickness over LCP with moderate accuracy. The ability of this multimodality imaging method to identify vulnerable coronary plaques requires further assessment in both larger autopsy studies, and clinical studies in patients undergoing NIRS-IVUS imaging.

  8. Quantitative measurement of ultrasound pressure field by optical phase contrast method and acoustic holography

    Science.gov (United States)

    Oyama, Seiji; Yasuda, Jun; Hanayama, Hiroki; Yoshizawa, Shin; Umemura, Shin-ichiro

    2016-07-01

    A fast and accurate measurement of an ultrasound field with various exposure sequences is necessary to ensure the efficacy and safety of various ultrasound applications in medicine. The most common method used to measure an ultrasound pressure field, that is, hydrophone scanning, requires a long scanning time and potentially disturbs the field. This may limit the efficiency of developing applications of ultrasound. In this study, an optical phase contrast method enabling fast and noninterfering measurements is proposed. In this method, the modulated phase of light caused by the focused ultrasound pressure field is measured. Then, a computed tomography (CT) algorithm used to quantitatively reconstruct a three-dimensional (3D) pressure field is applied. For a high-intensity focused ultrasound field, a new approach that combines the optical phase contrast method and acoustic holography was attempted. First, the optical measurement of focused ultrasound was rapidly performed over the field near a transducer. Second, the nonlinear propagation of the measured ultrasound was simulated. The result of the new approach agreed well with that of the measurement using a hydrophone and was improved from that of the phase contrast method alone with phase unwrapping.

  9. Learning evaluation of ultrasound image segmentation using combined measures

    Science.gov (United States)

    Fang, Mengjie; Luo, Yongkang; Ding, Mingyue

    2016-03-01

    Objective evaluation of medical image segmentation is one of the important steps for proving its validity and clinical applicability. Although there are many researches presenting segmentation methods on medical image, while with few studying the evaluation methods on their results, this paper presents a learning evaluation method with combined measures to make it as close as possible to the clinicians' judgment. This evaluation method is more quantitative and precise for the clinical diagnose. In our experiment, the same data sets include 120 segmentation results of lumen-intima boundary (LIB) and media-adventitia boundary (MAB) of carotid ultrasound images respectively. And the 15 measures of goodness method and discrepancy method are used to evaluate the different segmentation results alone. Furthermore, the experimental results showed that compared with the discrepancy method, the accuracy with the measures of goodness method is poor. Then, by combining with the measures of two methods, the average accuracy and the area under the receiver operating characteristic (ROC) curve of 2 segmentation groups are higher than 93% and 0.9 respectively. And the results of MAB are better than LIB, which proved that this novel method can effectively evaluate the segmentation results. Moreover, it lays the foundation for the non-supervised segmentation evaluation system.

  10. Femoral anteversion measured by ultrasound and CT: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Aamodt, A. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Terjesen, T. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Eine, J. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Kvistad, K.A. [Dept. of Radiology, Trondheim Univ. Hospital (Norway)

    1995-02-01

    Both computed tomography (CT) and ultrasonography have been used successfully to estimate the femoral anteversion (AV) angle. In this study, AV angles in 20 human adult femurs were determined by ultrasonography and CT and the measurements compared. On CT the real AV angle was measured as the angle between the head-neck centreline and the posterior condylar plane. In addition, the angle between the anterior head-trochanter (HT) tangent and the posterior condylar plane was determined. The latter angle was also measured by ultrasonography using the tilted transducer technique. The mean interobserver variation in the ultrasound measurements was 1.9 . We found ultrasonography to correlate very well with CT, both when comparing with the HT angle (r=0.95) and with the AV angle (r=0.93). The HT angle was on average 4 greater than the AV angle. In this study the accuracy of ultrasonography was {+-}5 and the method is recommended for screening in patients with rotational disorders of the femur. (orig.)

  11. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, E F; Strandberg, C; Bendtsen, F;

    1999-01-01

    with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated. METHODS: Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA...

  12. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, Erik Feldager; Strandberg, C; Bendtsen, F;

    1999-01-01

    echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug...

  13. Imaging of coronary atherosclerosis: Intravascular ultrasound

    NARCIS (Netherlands)

    H.M. Garcia-Garcia (Hector); M.A. Costa (Marco); P.W.J.C. Serruys (Patrick)

    2010-01-01

    textabstractAtherosclerosis is the main cause of coronary heart disease, which is today the leading cause of death worldwide and will continue to be the first in the world in 2030. In the formation of atherosclerotic coronary lesions, a critical primary step is the accumulation and oxidation of low-

  14. Intravascular "mulberry-like" bodies

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt; Klebe, J G; Henriques, U V

    1988-01-01

    Intravascular "mulberry-like" bodies in a stillborn female infant with moderate maceration are reported. The histogenesis of these structures is discussed based on light-microscopic, immunohistochemical and ultrastructural findings. No demonstrable causal relation between the intravascular lesions...... and fetal death was found, the cause of death being attributed to intrauterine asphyxia. It is concluded, that intravascular "mulberry-bodies" most likely represent artifacts due to red blood cell autolysis....

  15. Disseminated intravascular coagulation in cancer patients

    NARCIS (Netherlands)

    M. Levi

    2009-01-01

    Disseminated intravascular coagulation (DIC) is a syndrome that may complicate a variety of diseases, including malignant disease. DIC is characterized by widespread, intravascular activation of coagulation (leading to intravascular fibrin deposition) and simultaneous consumption of coagulation fact

  16. How Is Disseminated Intravascular Coagulation Treated?

    Science.gov (United States)

    ... the NHLBI on Twitter. How Is Disseminated Intravascular Coagulation Treated? Treatment for disseminated intravascular coagulation (DIC) depends ... and treat the underlying cause. Acute Disseminated Intravascular Coagulation People who have acute DIC may have severe ...

  17. Validation of Doppler ultrasound and magnetic resonance imaging velocity measurements by means of a test object

    NARCIS (Netherlands)

    Oostayen, J.A. van; Bezemer, R.A.; Wasser, M.N.J.M.; Teirlinck, C.J.P.M.

    1996-01-01

    Objective: To validate Doppler ultrasound and MRI mean velocity measurements in a test object in which mean velocities are known and can be chosen within a range of 10-100 cm/s in tubes of 4 and 8 mm. This validation was carried out to check the performance of a duplex Doppler ultrasound system that

  18. Correlation between self-reported gestational age and ultrasound measurements

    DEFF Research Database (Denmark)

    Olesen, Annette Wind; Westergaard, Jes Grabow; Thomsen, Sten Grove;

    2004-01-01

    Hospital Discharge Register. METHODS: The ultrasound-estimated gestational length was based on the size of the biparietal diameter. The ultrasound-estimated gestational length was related to corrected and uncorrected last menstrual period estimates in the Danish National Cohort Study......, and to the gestational length recorded in the Danish National Discharge Register. Non-parametric statistics were used in the analysis. RESULTS: The gestational ages estimated by ultrasound were 2-3 days shorter than gestational ages estimated by the other methods. The gestational ages recorded by the Discharge Register...

  19. Measurement of a PAGAT gel dosimeter by ultrasound computed tomography

    Science.gov (United States)

    Khoei, S.; Trapp, J. V.; Langton, C. M.

    2013-06-01

    In this work we used a 3D quantitative CT ultrasound imaging system to characterise polymer gel dosimeters. The system comprised of two identical 5 MHz 128 element phased-array ultrasound transducers co-axially aligned and submerged in water as a coupling agent. Rotational and translational movement of the gel dosimeter sample between the transducers were performed using a robotic arm. Ultrasound signals were generated and received using an Olympus Omniscan unit. Dose sensitivity of attenuation and time of flight ultrasonic parameters were assessed using this system.

  20. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network.

    Science.gov (United States)

    Xing, Jida; Chen, Jie

    2015-06-23

    In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared to our previous

  1. Comparative study of the intravascular ultrasound and optical coherence tomography in stenting strategy selection and its prognostic impact in coronary bifurcation lesions%血管内超声与光学相干断层显像对冠状动脉分叉病变手术策略及预后影响的对照研究

    Institute of Scientific and Technical Information of China (English)

    殷拥军; 孔令秋; 张宏才; 伍洲; 赵珏; 黄大军; 许勇; 聂谦

    2016-01-01

    Objective To investigate the reliability of the intravascular ultrasound(IVUS)and optical coherence tomography(OCT)in stenting strategy selection and its prognostic impact in coronary bifurcation lesions.Methods A total of 157 patients with coronary artery disease were prospectively studied by using angiography,OCT,and IVUS. Quantitative image analyses of the coronary bifurcation lesions were performed.The stenting strategy selection and its prognostic impact were evaluated.Results In the clinical study,the mean minimum lumen diameter(MLD)and the minimum lumen area(MLA) measured by QCA were significantly smaller than those measured by IVUS and OCT (P 0.05),although the OCT seems better in the follow-up.Conclusions IVUS and OCT provide accurate and reproducible quantitative measurements of coronary artery,all of them were reliable in stenting strategy selection.%目的:对比血管内超声(IVUS)及光学相干断层显像(OCT)对冠状动脉分叉病变经皮冠状动脉介入治疗(PCI)手术策略选择及预后的影响。方法冠状动脉造影明确为分叉病变的患者157例,使用冠状动脉定量分析(QCA)测量最小管腔直径(MLD)、最小管腔横截面积(MLA)、参照管腔直径(RLD),其后随机进行 IVUS (84例)和 OCT检查(73例),测量并比较上述参数与 QCA测值的差异;比较不同方法所指导的支架植入方案心血管事件发生率。结果通过 IVUS 及 OCT 所测冠状动脉 MLD、MLA、RLD 均高于 QCA 法,其中 MLD、MLA 差异有统计学意义(P 0.05)。结论IVUS 和OCT 均可用于指导分叉病变患者PCI 策略选择。

  2. Comparison of portable and conventional ultrasound imaging in spinal curvature measurement

    Science.gov (United States)

    Yan, Christina; Tabanfar, Reza; Kempston, Michael; Borschneck, Daniel; Ungi, Tamas; Fichtinger, Gabor

    2016-03-01

    PURPOSE: In scoliosis monitoring, tracked ultrasound has been explored as a safer imaging alternative to traditional radiography. The use of ultrasound in spinal curvature measurement requires identification of vertebral landmarks, but bones have reduced visibility in ultrasound imaging and high quality ultrasound machines are often expensive and not portable. In this work, we investigate the image quality and measurement accuracy of a low cost and portable ultrasound machine in comparison to a standard ultrasound machine in scoliosis monitoring. METHODS: Two different kinds of ultrasound machines were tested on three human subjects, using the same position tracker and software. Spinal curves were measured in the same reference coordinate system using both ultrasound machines. Lines were defined by connecting two symmetric landmarks identified on the left and right transverse process of the same vertebrae, and spinal curvature was defined as the transverse process angle between two such lines, projected on the coronal plane. RESULTS: Three healthy volunteers were scanned by both ultrasound configurations. Three experienced observers localized transverse processes as skeletal landmarks and obtained transverse process angles in images obtained from both ultrasounds. The mean difference per transverse process angle measured was 3.00 +/-2.1°. 94% of transverse processes visualized in the Sonix Touch were also visible in the Telemed. Inter-observer error in the Telemed was 4.5° and 4.3° in the Sonix Touch. CONCLUSION: Price, convenience and accessibility suggest the Telemed to be a viable alternative in scoliosis monitoring, however further improvements in measurement protocol and image noise reduction must be completed before implementing the Telemed in the clinical setting.

  3. Damage Detection in Concrete Using Diffuse Ultrasound Measurements

    Science.gov (United States)

    Deroo, Frederik; Jacobs, Laurence J.; Kim, Jin-Yeon; Qu, Jianmin; Sabra, Karim

    2010-02-01

    Heterogeneities in concrete caused by the random distribution of aggregate in the cement-paste matrix lead to strong scattering of ultrasonic waves at wavelengths on the order of the aggregate. Use of these high frequencies is necessary to detect damage at an early stage, something that is not possible with conventional ultrasonic methods. The ultrasound energy density in that regime can be described by the diffusion equation. The objective of this research is to develop a quantitative understanding of the effects of additional scattering sources, such as small cracks in the cement-paste matrix, on the parameters of the diffusion equation; these parameters are the diffusion and the dissipation coefficients. Applying diffusion theory, the diffusivity and dissipation coefficients are experimentally determined as functions of frequency using ultrasonic waves. The cuboid shaped samples employed are made of a Portland cement-paste matrix and regular aggregate, such as gravel and sand. The results provide a basic understanding of repeatability and consistency of diffusion measurements, with an emphasis on the nondestructive evaluation of concrete.

  4. Measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography.

    Science.gov (United States)

    Chino, Kentaro; Akagi, Ryota; Dohi, Michiko; Takahashi, Hideyuki

    2014-09-01

    The B-mode ultrasound image that can measure muscle architecture is displayed side by side with the ultrasound strain elastogram that can assess muscle hardness. Consequently, muscle architecture can be measured concurrently with muscle hardness using ultrasound strain elastography. To demonstrate the measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography. Concurrent measurements of muscle architectural parameters (muscle thickness, pennation angle, and fascicle length) and muscle hardness of the medial gastrocnemius were performed with ultrasound strain elastography. Separate measurements of the muscle architectural parameters were also performed for use as reference values for the concurrent measurements. Both types of measurements were performed twice at 20° dorsiflexion, neutral position, and 30° plantar flexion. Coefficients of variance of the muscle architectural parameters obtained from the concurrent measurements (≤7.6%) were significantly higher than those obtained from the separate measurements (≤2.4%) (all P muscle architectural parameters between the concurrent and separate measurements (all P > 0.05). The use of ultrasound strain elastography for the concurrent measurement of muscle architecture and muscle hardness is feasible. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  5. Reliability of period of gestation determined by ultrasound scan measurements

    Directory of Open Access Journals (Sweden)

    Chrishantha Abeysena

    2011-05-01

    Full Text Available Methods: One hundred and eighty pregnant women were divided into three equal groups. Each group was assigned a rater to perform ultrasound scan to measure bi-parietal diameter, femur length, abdominal circumference and head circumference and to compute the respective periods of gestation using these four measurements. Reliability between periods of gestation derived by each rater from above four measurements were analysed using repeated measure ANOVA. Results were expressed as intra-class correlation coefficients (ICCs and coefficients of variation (CsOV.Results: For Raters I (F= 6.47; p=0.001 and II, (F= 4.80; p= 0.003, computations using abdominal circumferences resulted in the lowest mean periods of gestation (PsOG. For Rater III, computations using both femur length and abdominal circumference resulted in the lowest mean periods of gestation (F= 7.5; p=0.001. ICCs were 0.73 (95%CI 0.64–0.81 for Rater I, 0.78 (95% CI 0.70–0.85 for Rater II and 0.87 (95% CI 0.81– 0.91 for Rater IIIWhen comparing CsOV, the highest variation for Raters I and III was observed for femur length. For Rater II it was bi-parietal diameter. The lowest variation for Rater I was observed for head circumference and for Raters II and III for abdominal circumference. The highest CsOV of all the PsOG were demonstrated by Rater III.When comparing the differences between the highest and the lowest values for each period of gestation determined, the difference was more than two weeks for 38% (n=23, 24% (n=14 and 22% (n=13 of observations made by Raters I, II and III respectively. Conclusions: Reliability of period of gestation depends on the type of measurement taken, method of assessment and the rater who performs the measurements. Our findings are not conclusive enough to recommend any PsOG based on specific measurement more reliable than others. In-service training of the obstetricians is likely to improve the reliability of PsOG determined using ultra sound scan

  6. Treatment of Disseminated Intravascular Coagulation.

    Science.gov (United States)

    Makruasi, Nisa

    2015-11-01

    Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic activation of blood coagulation, generation of thrombin, and leading to disturbance of the microvasculature. In this article, definition and diagnostic criteria of DIC depend on the International Society of Thrombosis and Haemostasis (ISTH). There is no gold standard for diagnosis of DIC, only low quality evidence is used in general practice. Many diagnostic tests and repeated measurement are required. For the treatment of DIC, there is no good quality evidence. The most important treatment for DIC is the specific treatment of the conditions associated DIC. Platelets and/or plasma transfusion may be also necessary if indicated. Nevertheless, there is no gold standard for diagnosis and treatment of DIC, we use only low quality evidence in general practice.

  7. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    Directory of Open Access Journals (Sweden)

    Jorge J

    2013-02-01

    Full Text Available J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry, School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT and anterior chamber depth (ACD with that of CCT measurements obtained by ultrasound pachymetry and ACD measurements obtained by ultrasound biometry, respectively.Methods: CCT and ACD was measured in 50 right eyes from 50 healthy subjects using a Sirius Scheimpflug camera, SP100 ultrasound pachymetry, and US800 ultrasound biometry.Results: CCT measured with the Sirius was 546 ± 39 µm and 541 ± 35 µm with SP100 ultrasound pachymetry (P = 0.003. The difference was statistically significant (mean difference 4.68 ± 10.5 µm; limits of agreement −15.8 to 25.20 µm. ACD measured with the Sirius was 2.96 ± 0.3 mm compared with 3.36 ± 0.29 mm using US800 ultrasound biometry (P < 0.001. The difference was statistically significant (mean difference −0.40 ± 0.16 mm; limits of agreement −0.72 to 0.07 mm. When the ACD values obtained using ultrasound biometry were corrected according to the values for CCT measured by ultrasound, the agreement increased significantly between both technologies for ACD measurements (mean difference 0.15 ± 0.16 mm; limits of agreement −0.16 to 0.45 mm.Conclusion: CCT and ACD measured by Sirius and ultrasound methods showing good agreement between repeated measurements obtained in the same subjects (repeatability with either instrument. However, CCT and ACD values, even after correcting ultrasound ACD by subtracting the CCT value obtained with either technology should not be used interchangeably.Keywords: Scheimpflug corneal tomography, ultrasound biometry, ultrasound pachymetry, limits of agreement

  8. Measuring Femoral Torsion In Vivo Using Freehand 3-D Ultrasound Imaging.

    Science.gov (United States)

    Passmore, Elyse; Pandy, Marcus G; Graham, H Kerr; Sangeux, Morgan

    2016-02-01

    Despite variation in bone geometry, muscle and joint function is often investigated using generic musculoskeletal models. Patient-specific bone geometry can be obtained from computerised tomography, which involves ionising radiation, or magnetic resonance imaging (MRI), which is costly and time consuming. Freehand 3-D ultrasound provides an alternative to obtain bony geometry. The purpose of this study was to determine the accuracy and repeatability of 3-D ultrasound in measuring femoral torsion. Measurements of femoral torsion were performed on 10 healthy adults using MRI and 3-D ultrasound. Measurements of femoral torsion from 3-D ultrasound were, on average, smaller than those from MRI (mean difference = 1.8°; 95% confidence interval: -3.9°, 7.5°). MRI and 3-D ultrasound had Bland and Altman repeatability coefficients of 3.1° and 3.7°, respectively. Accurate measurements of femoral torsion were obtained with 3-D ultrasound offering the potential to acquire patient-specific bone geometry for musculoskeletal modelling. Three-dimensional ultrasound is non-invasive and relatively inexpensive and can be integrated into gait analysis.

  9. Measurement of the absorbed dose distribution near an 192Ir intravascular brachytherapy seed using a high-spatial-resolution gel dosimetry system

    Science.gov (United States)

    Massillon-JL, G.; Minniti, R.; Mitch, M. G.; Soares, C. G.

    2012-06-01

    The absorbed dose distribution at sub-millimeter distances from the Best single 192Ir intravascular brachytherapy seed was measured using a high-spatial-resolution gel dosimetry system. Two gel phantoms from the same batch were used; one for the seed irradiation and one for calibration. Since the response of this gel is energy independent for photons between 20 and 1250 keV, the gel was calibrated using a narrowly collimated 60Co gamma-ray beam (cross-sectional area ˜1 cm2). A small format laser computed tomography scanner was used to acquire the data. The measurements were carried out with a spatial resolution of 100 µm in all dimensions. The seed was calibrated at NIST in terms of air-kerma strength. The absorbed dose rate as well as the radial dose function, gL(r), was measured for radial distances between 0.6 and 12.6 mm from the seed center. The dose rate constant was measured, yielding a value of Λ = (1.122 ± 0.032) cGy h-1 U-1, which agrees with published data within the measurement uncertainty. For distances between 0.6 and 1.5 mm, gL(r) decreases from a maximum value of 1.06 down to 1.00; between 1.5 and 6.7 mm, an enhancement is clearly observed with a maximum value around 1.24 and beyond 6.7 mm, gL(r) has an approximately constant value around 1.0, which suggests that this seed can be considered as a point source only at distances larger than 6.7 mm. This latter observation agrees with data for the same seed reported previously using Gafchromic film MD-55-2. Additionally, published Monte Carlo (MC) calculations have predicted the observed behavior of the radial dose function resulting from the absorbed dose contributions of beta particles and electrons emitted by the 192Ir seed. Nonetheless, in the enhancement region, MC underestimates the dose by approximately 20%. This work suggests that beta particles and electrons emitted from the seed make a significant contribution to the total absorbed dose delivered at distances near the seed center (less

  10. An automated in vitro model for the evaluation of ultrasound modalities measuring myocardial deformation

    Directory of Open Access Journals (Sweden)

    Stigö Albin

    2010-09-01

    Full Text Available Abstract Background Echocardiography is the method of choice when one wishes to examine myocardial function. Qualitative assessment of the 2D grey scale images obtained is subjective, and objective methods are required. Speckle Tracking Ultrasound is an emerging technology, offering an objective mean of quantifying left ventricular wall motion. However, before a new ultrasound technology can be adopted in the clinic, accuracy and reproducibility needs to be investigated. Aim It was hypothesized that the collection of ultrasound sample data from an in vitro model could be automated. The aim was to optimize an in vitro model to allow for efficient collection of sample data. Material & Methods A tissue-mimicking phantom was made from water, gelatin powder, psyllium fibers and a preservative. Sonomicrometry crystals were molded into the phantom. The solid phantom was mounted in a stable stand and cyclically compressed. Peak strain was then measured by Speckle Tracking Ultrasound and sonomicrometry. Results We succeeded in automating the acquisition and analysis of sample data. Sample data was collected at a rate of 200 measurement pairs in 30 minutes. We found good agreement between Speckle Tracking Ultrasound and sonomicrometry in the in vitro model. Best agreement was 0.83 ± 0.70%. Worst agreement was -1.13 ± 6.46%. Conclusions It has been shown possible to automate a model that can be used for evaluating the in vitro accuracy and precision of ultrasound modalities measuring deformation. Sonomicrometry and Speckle Tracking Ultrasound had acceptable agreement.

  11. Intravascular ultrasound and virtual histology study on nonculprit lesion in acute coronary syndrome patients with type 2 diabetes mellitus%急性冠状动脉综合征及合并2型糖尿病患者非罪犯病变的血管内超声-虚拟组织学特点的研究

    Institute of Scientific and Technical Information of China (English)

    郑婕舒; 张元春; 贺迅; 戴磊; 罗常有; 刘祖恒; 尹庆; 王善花; 苏伟平

    2013-01-01

    目的 急性冠状动脉综合征(ACS)及合并T2DM患者非罪犯病变的血管内超声-虚拟组织学(IVUS-VH)特点与罪犯病变进行比较,为临床处理非罪犯病变提供参考. 方法 选取ACS患者60例,其中合并T2DM 17例,入选者分别行3条血管IVUS-VH检查,测量病变的IVUS-VH指标,检出薄纤维帽粥样斑块(VH-TCFA),确定罪犯病变后分为罪犯病变组(A组)与非罪犯病变组(B组)进行比较.结果 两组VH-TCFA检出率一致(66.7%vs66.7%,P=1.000). 结论 ACS患者(包括合并T2DM)非罪犯病变同样具有易损性.%Objective To compare the characteristics of non-culprit lesion with culprit lesion in acute coronary syndrome (ACS) patients with T2DM to provide the references for the clinical management of non-culprit lesion.Methods The 3-vessel intravascular ultrasound and virtual history (IVUS-VH) analysis was performed for 60 ACS patients,17 of them with T2DM.The parameters of IVUS-VH were measured for all the lesions.The thin-cap fibroatheromas (VH-TCFA) were detected.After the culprit lesion was diagnosed first,the culprit and nonculprit lesion groups were compared to observe the characteristics between them.Results The detectable rate of IVUS-VH derived thin-cap fibroatheroma (VH-TCFA) was the same (66.7% vs 66.7%,P=1.000) in the nonculprit versus culprit lesion groups.Conclusion Nonculprit.lesion is vulnerable in ACS patients (some of them with T2DM).

  12. Cardiac In-vivo Measurements Using Synthetic Transmit Aperture Ultrasound

    DEFF Research Database (Denmark)

    Andresen, Henrik; Nikolov, Svetoslav; Hassager, Christian

    2006-01-01

    This paper investigates the feasibility of acquiring cardiac images using synthetic transmit aperture (STA) ultrasound. Focusing in STA is done by beamforming all points in the image for every emission, creating a low-resolution image. The low-resolution images for each emission are summed......, together with the RASMUS experimental ultrasound scanner. Both transducers have a pitch of half a wavelength. To ensure an adequate signal-to-noise ratio, a 20 mus non-linear frequency modulated chirp and a 7-element de-focused virtual source were used for transmission. The number of virtual sources used...

  13. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... kidneys. There are three types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements ...

  14. Factors Affecting Estimated Fetal Weight Measured by Ultrasound

    Directory of Open Access Journals (Sweden)

    Hasan Energin

    2016-06-01

    Full Text Available Objective: In this study, we aimed to evaluate the fac­tors that affect the accuracy of estimated fetal weight in ultrasound. Methods: This study was conducted in 3rd degree hospi­tal antenatal outpatient clinic and perinatology inpatient clinic between June 2011 and January 2012. The data were obtained from 165 pregnant women. Inclusion cri­teria were; no additional diseases, giving birth within 48 hours after ultrasound. The same physician executed all ultrasound process. Age, height, weight, obstetric history and obstetric follow –up findings were recorded. Results: Fetal gender, fetal presentation, presence of meconium in amniotic fluid, maternal parity, did not sig­nificantly affect the accuracy of fetal weight estimation by ultrasound. The mean difference between estimated fetal weight and birth weight was 104.48±84 gr in nullipars and 94.2±81 gr in multipars (p=0.44; mean difference was 98.22±79 gr in male babies and 98.15±86 gr in female babies (p=0.99. Mean difference between estimated fetal weight and birth weight was 96.92±81 gr in babies with cephalic presentation and 110.9±90 gr in babies with breech presentation (p=0.53; this difference was 95.36±79 gr in babies with amniotic fluid with meconium and 98.82± 83 gr in babies with amniotic fluid without me­conium (p=0.83. Conclusion: Fetal weight is estimation is one of key points in the obstetrician’s intrapartum managament. And it is important to make fetal weight estimation accurately. In our study, consistent with literature, we observed that fetal gender; meconium presence in amniotic fluid, fetal presentation, maternal parity does not significantly effect the accuracy of fetal weight estimation by ultrasound.

  15. Measurement of Thermal Effects of Doppler Ultrasound: An In Vitro Study.

    Directory of Open Access Journals (Sweden)

    Samir Helmy

    Full Text Available Ultrasound is considered a safe imaging modality and is routinely applied during early pregnancy. However, reservations are expressed concerning the application of Doppler ultrasound in early pregnancy due to energy emission of the ultrasound probe and its conversion to heat. The objective of this study was to evaluate the thermal effects of emitted Doppler ultrasound of different ultrasound machines and probes by means of temperature increase of in-vitro test-media.We investigated the energy-output of 5 vaginal and abdominal probes of 3 ultrasound machines (GE Healthcare, Siemens, Aloka. Two in-vitro test objects were developed at the Center for Medical Physics and Biomedical Engineering, Medical University Vienna (water bath and hydrogel bath. Temperature increase during Doppler ultrasound emission was measured via thermal sensors, which were placed inside the test objects or on the probes' surface. Each probe was emitting for 5 minutes into the absorbing test object with 3 different TI/MI settings in Spectral Doppler mode.During water bath test, temperature increase varied between 0.1 and 1.0°C, depending on probe, setting and focus, and was found highest for spectral Doppler mode alone. Maximum temperature increase was found during the surface heating test, where values up to 2.4°C could be measured within 5 minutes of emission.Activation of Doppler ultrasound in the waterbath model causes a significant increase of temperature within one minute. Thermally induced effects on the embryo cannot be excluded when using Doppler ultrasound in early pregnancy.

  16. Measurement of neonatal heart rate using handheld Doppler ultrasound.

    Science.gov (United States)

    Dyson, Amanda; Jeffrey, Michele; Kluckow, Martin

    2017-03-01

    This pilot study aimed to determine whether handheld Doppler ultrasound is feasible and reliable for measuring neonatal heart rate (HR) when compared with ECG. Stable newborns were recruited from the neonatal intensive care unit and postnatal ward between July 2014 and January 2015 at Royal North Shore Hospital, Sydney, Australia. Each newborn had their HR recorded every 15 s over 145 s using four different modalities: ECG, counted audible Doppler (AD) over 10 s, pulse oximetry (PO) and the Doppler display (DD). The correlation and variation between each modality and ECG. 51 newborns with a median gestational age of 38 weeks (27-41) and a mean weight of 2.78 kg (0.82 to 4.76) with a median postnatal age of 3 days (0-87) were studied. There was a mean difference of 0.69 bpm (95% CI -2.9 to +1.5) between AD-HR and ECG-HR with good correlation between modalities (r=0.94, p<0.01). The median time to achieve AD-HR was 3 s (1-45). The mean difference between DD-HR and ECG-HR was 5.37 bpm (95% CI -12.8 to +2.1) with moderate correlation (r=0.37, p=0.04). The mean difference between PO-HR and ECG-HR was 0.49 bpm (95% CI -1.5 to +0.51) with good correlation (r=0.99, p<0.01). The variability between AD-HR and ECG-HR decreased with decreasing weight. AD-HR correlates well with ECG-HR. Further research in the delivery room is recommended before using AD-HR in this area. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Non-invasive measurement of pressure gradients using ultrasound

    DEFF Research Database (Denmark)

    Olesen, Jacob Bjerring; Traberg, Marie Sand; Pihl, Michael Johannes

    2013-01-01

    A non-invasive method for estimating 2-D pressure gradients from ultrasound vector velocity data is presented. The method relies on in-plane vector velocity fields acquired using the Transverse Oscillation method. The pressure gradients are estimated by applying the Navier-Stokes equations...... Medical 2202 UltraView Pro Focus scanner. The results are validated through finite element simulations of the carotid flow model where the geometry is determined from MR images. This proof of concept study was conducted at nine ultrasound frames per second. Estimated pressure gradients along...... the longitudinal direction of the constriction varied from 0 kPa/m to 10 kPa/m with a normalized bias of -9.1% for the axial component and -7.9% for the lateral component. The relative standard deviation of the estimator, given in reference to the peak gradient, was 28.4% in the axial direction and 64...

  18. Intravascular large B cell lymphoma

    Directory of Open Access Journals (Sweden)

    Ricardo García-Muñoz

    2014-01-01

    Full Text Available Intravascular large B cell lymphoma (IVBCL is a rare type of extranodal large B cell lymphoma characterized by selective growth of lymphoma cells within the microvasculature. We present an illustrative case of intravascular B cell lymphoma suspected by the presence of a very small monoclonal B cell population identified by immunophenotype and polymerase chain reaction in bone marrow. The diagnosis was confirmed by skin biopsy.

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  20. Ultrasound -- Pelvis

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    Full Text Available ... transducer into the body. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  1. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  2. Measuring wheel/rail contact stresses using ultrasound

    OpenAIRE

    Marhsall, M.B.; Lewis, R.; Dwyer-Joyce, R.S.; Olofsson, O.; Bjorklund, S

    2004-01-01

    The investigation of contact area and pressure distribution in a wheel/rail contact is essential information required in fatigue and wear calculations to determine design life, regrinding requirements, and maintenance schedules. The aim of this work was to use ultrasound to non-destructively determine wheel/rail contact pressures. Three different contacts were investigated those resulting from; un-used, sand damaged, and worn wheel/rail specimens. \\ud \\ud A wheel/rail interface behaves like a...

  3. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Jida Xing

    2015-06-01

    Full Text Available In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared

  4. Submental ultrasound measurement of dynamic tongue base thickness in patients with obstructive sleep apnea.

    Science.gov (United States)

    Chen, Jeng-Wen; Chang, Chun-Hsiang; Wang, Shou-Jen; Chang, Yen-Teh; Huang, Chih-Chung

    2014-11-01

    Dynamic tongue base thickness (TBT) may be an important anatomic factor in airway narrowing in patients with obstructive sleep apnea (OSA). The development of an accurate clinical assessment of the retroglossal airway in patients with OSA is still evolving. Submental ultrasound was used to investigate the association between measurements of TBT in response to negative airway pressure and the existence of OSA. Twenty OSA patients and 20 control participants underwent ultrasound measurement of TBT on eupneic breathing and with the Mueller maneuver, as well as clinical and polysomnographic assessments. Logistic regression analyses indicated that after adjustment for confounding factors, independent predictors of OSA included TBT in response to negative airway pressure, as measured by submental ultrasound with the Mueller maneuver (odds ratio: 2.11, 95% confidence interval: 1.15-3.87, p measurement of TBT during the Mueller maneuver provides a quantitative assessment of the retroglossal airway in OSA patients with minimal invasiveness and easy accessibility.

  5. Ultrasound pregnancy

    Science.gov (United States)

    Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; ...

  6. The influence of cortical end-plate on broadband ultrasound attenuation measurements at the human calcaneus using scanning confocal ultrasound

    Science.gov (United States)

    Xia, Yi; Lin, Wei; Qin, Yi-Xian

    2005-09-01

    Quantitative ultrasound (QUS) assessment, including broadband ultrasound attenuation (BUA), is an efficient technique for assessing bone quality in various statuses, e.g., osteoporosis. While assessing trabecular bone loss is essential to bone quality, the existence of cortical bone can substantially reduce the accuracy of BUA measurement. In this study, we developed an approach to quantify the influence of the cortical end-plate in the QUS on 18 cadaver calcanei using both analytical and experimental analyses. A simplified cortical-trabecular-cortical sandwich model has been developed for simulation of wave propagations. Results show that the cortical end-plate has a significant effect on BUA (yielding 8.5+/-3.6 dB/MHz in cortical bone alone), approximately 15% of the BUA value over the whole bone BUA measurement (54.1+/-20.1 dB/MHz). The phenomenon has been predicted by the developed analytical model with a high correlation (r2=0.63,pdiagnosis of bone diseases.

  7. The Use of B-Mode Ultrasound for Measuring Subcutaneous Fat Thickness on the Upper Arms.

    Science.gov (United States)

    Weiss, Lawrence W.; Clark, Frank C.

    1985-01-01

    A study was carried out to investigate the potential use of B-mode ultrasound for measuring subcutaneous fat thickness at two arm sites. B-mode sonograms and skinfold measurements were found to be highly correlated for both men and women. (Author/MT)

  8. Measuring Bubble, Drop and Particle Sizes in Multiphase Systems with Ultrasound

    NARCIS (Netherlands)

    Cents, A.H.G.; Brilman, D.W.F.; Versteeg, G.F.; Wijnstra, P.J.; Regtien, P.P.L.

    2004-01-01

    A technique is developed for measurement of bubble, droplet and particle-size distributions in multiphase systems, based on the propagation speed and attenuation of ultrasound. The measurement of the size distribution of the dispersed phase in multiphase systems was desired to analyze the mass-trans

  9. The Use of B-Mode Ultrasound for Measuring Subcutaneous Fat Thickness on the Upper Arms.

    Science.gov (United States)

    Weiss, Lawrence W.; Clark, Frank C.

    1985-01-01

    A study was carried out to investigate the potential use of B-mode ultrasound for measuring subcutaneous fat thickness at two arm sites. B-mode sonograms and skinfold measurements were found to be highly correlated for both men and women. (Author/MT)

  10. Mechanism modeling for phase fraction measurement with ultrasound attenuation in oil–water two-phase flow

    Science.gov (United States)

    Su, Qian; Tan, Chao; Dong, Feng

    2017-03-01

    When measuring the phase fraction of oil–water two-phase flow with the ultrasound attenuation, the phase distribution and fraction have direct influence on the attenuation coefficient. Therefore, the ultrasound propagation at various phase fractions and distributions were investigated. Mechanism models describing phase fraction with the ultrasound attenuation coefficient were established by analyzing the interaction between ultrasound and two-phase flow by considering the scattering, absorption and diffusion effect. Experiments were performed to verify the theoretical analysis, and the test results gave good agreement with the theoretical analysis. When the dispersed phase fraction is low, the relationship between ultrasound attenuation coefficient and phase fraction is of monotonic linearity; at higher dispersed phase fraction, ultrasound attenuation coefficient presents an irregular response to the dispersed phase fraction. The presented mechanism models give reasonable explanations about the trend of ultrasound attenuation.

  11. 虚拟组织学成像血管内超声在冠心病临床治疗中的应用进展%Progress of the Use of Virtual Histology Intravascular Ultrasound in the Study of Treatment of Coronary Artery Disease

    Institute of Scientific and Technical Information of China (English)

    胡晓辉

    2011-01-01

    The virtual histology intravascular ultrasound is characterized by the real-time histological analysis f coronary artery plaque.The use of such technique in coronary heart disease patients suggest that on the virtual histology intravascular ultrasound acute coronary syndrome patients are more frequently complicated with large necrotic core in close contact with the lumen in the absence of fibrous cap.Such plaques also frequently occur in nonculprit arteries with a stenosis less than 50% in diameter for acute coronary syndrome patients, showing a larger necrotic core in proximal arterial plaque.The drug-eluting stent fails to reduce the lipid core and impairs the neogeneration of endothelia in a relative long period.The large necrotic core is associated with the absence of repetfusion during the interventional therapy.The series of studies show that statins decrease the lipid content in plaque but increase that of fibrous tissues.%虚拟组织学成像血管内超声的特点是可以对冠状动脉的斑块进行实时组织学分析.利用这一技术对冠心病患者的研究提示:虚拟组织学成像血管内超声显示的坏死核大、坏死核和管腔直接接触、没有纤维帽的斑块多见于急性冠状动脉综合征患者,也多见于急性冠状动脉综合征患者的直径狭窄<50%的非罪犯血管段,而且冠状动脉的近段斑块坏死核较大;药物洗脱支架没能减少斑块的脂核,且在较长的时间内影响着内皮新生;斑块中大的坏死核与介入治疗时的无复流有关;系列研究显示,他汀治疗可以减少斑块脂质成分,增加纤维组织.

  12. Blood flow measurements during hemodialysis vascular access interventions - Catheter-based thermodilution or Doppler ultrasound?

    DEFF Research Database (Denmark)

    Heerwagen, Søren T; Hansen, Marc A; Schroeder, Torben V

    2012-01-01

    Purpose: To test the clinical performance of catheter-based thermodilution and Doppler ultrasound of the feeding brachial artery for blood flow measurements during hemodialysis vascular access interventions.Methods: Thirty patients with arteriovenous fistulas who underwent 46 interventions had...... by ultrasound dilution was determined within three days of the procedure. The methods were compared using regression analysis and tested for systematic bias. Results: Failure to position the thermodilutional catheter correctly was observed in 8 out of 46 (17%) pre-intervention measurements. Post...

  13. Proopiomelanocortin gene polymorphisms and its association with meat quality traits by ultrasound measurement in Chinese cattle.

    Science.gov (United States)

    Liu, Yongfeng; Zan, Linsen; Li, Linqiang; Xin, Yaping

    2013-10-15

    Ultrasound technology was used to measure live animal meat traits instead of true carcass meat traits for beef production and cattle breeding by an increasing number of institutions. In this study, we analyzed the association between genetic polymorphisms of proopiomelanocortin (POMC) and ultrasound measurement traits in Chinese cattle. Using direct DNA sequencing in 322 individuals of 7 different cattle subpopulation, 7 SNPs were identified for genotyping within 790bp region of intron 2 and exon 3 of POMC. 6586 T>G in intron 2 and 6769 C>T and 7216 C>T in exon 3 were significantly associated with ultrasound backfat thickness (UBF) (PT, 6706 T>C, 6796 C>T and 6810 C>T in exon 3 were significantly associated with ULMA (Pmeat in Chinese cattle breeding program. Following validation in other populations and breeds, these markers could be incorporated into breeding programs to increase the rate of improvement in carcass and meat quality traits.

  14. Force-controlled ultrasound to measure passive mechanical properties of muscle in Duchenne muscular dystrophy.

    Science.gov (United States)

    Pigula, Anne J; Wu, Jim S; Gilbertson, Matthew W; Darras, Basil T; Rutkove, Seward B; Anthony, Brian W

    2016-08-01

    The purpose of this study is to assess differences in skeletal muscle compressibility between patients with Duchenne muscular dystrophy (DMD) and normal subjects. The transverse passive mechanical properties of muscle, particularly those related to stiffness and elasticity, can be measured using force-controlled ultrasound. We acquired ultrasound videos of muscle compression under known pressures in the biceps and quadriceps in 23 boys with DMD and 20 age-matched healthy controls. We calculated the bulk linear spring constant, nonlinear stress-strain response, and average Young's modulus for each. Young's modulus was found to be significantly higher in the DMD population in both the biceps (normal: 33 ± 6 kPa, DMD: 45 ± 14, p Muscle compressibility measured by force-controlled ultrasound is an objective and robust technique to quantitatively monitor the effects of DMD and distinguish from normal subjects.

  15. The cardiac cycle is a major contributor to variability in size measurements of abdominal aortic aneurysms by ultrasound

    DEFF Research Database (Denmark)

    Grøndal, Nikolaj Fibiger; Bramsen, Morten; Thomsen, Marie Dahl

    2012-01-01

    The objective of the study was to evaluate the impact of the cardiac cycle on ultrasound measurements of abdominal aortic aneurysm (AAA) diameters.......The objective of the study was to evaluate the impact of the cardiac cycle on ultrasound measurements of abdominal aortic aneurysm (AAA) diameters....

  16. Preterm neonatal lateral ventricle volume from three-dimensional ultrasound is not strongly correlated to two-dimensional ultrasound measurements.

    Science.gov (United States)

    Kishimoto, Jessica; de Ribaupierre, Sandrine; Salehi, Fateme; Romano, Walter; Lee, David S C; Fenster, Aaron

    2016-10-01

    The aim of this study is to compare longitudinal two-dimensional (2-D) and three-dimensional (3-D) ultrasound (US) estimates of ventricle size in preterm neonates with posthemorrhagic ventricular dilatation (PHVD) using quantitative measurements of the lateral ventricles. Cranial 2-D US and 3-D US images were acquired from neonatal patients with diagnosed PHVD within 10 min of each other one to two times per week and analyzed offline. Ventricle index, anterior horn width, third ventricle width, and thalamo-occipital distance were measured on the 2-D images and ventricle volume (VV) was measured from 3-D US images. Changes in the measurements between successive image sets were also recorded. No strong correlations were found between VV and 2-D US measurements ([Formula: see text] between 0.69 and 0.36). Additionally, weak correlations were found between changes in 2-D US measurements and 3-D US VV ([Formula: see text] between 0.13 and 0.02). A trend was found between increasing 2-D US measurements and 3-D US-based VV, but this was not the case when comparing changes between 3-D US VV and 2-D US measurements. If 3-D US-based VV provides a more accurate estimate of ventricle size than 2-D US measurements, moderate-weak correlations with 3-D US suggest that monitoring preterm patients with PHVD using 2-D US measurements alone might not accurately represent whether the ventricles are progressively dilating. A volumetric measure (3-D US or MRI) could be used instead to more accurately represent changes.

  17. STEREOCHEMICAL ASPECTS OF HYDRATION OF CARBOHYDRATES IN AQUEOUS-SOLUTIONS .3. DENSITY AND ULTRASOUND MEASUREMENTS

    NARCIS (Netherlands)

    GALEMA, SA; HOILAND, H

    1991-01-01

    Density and ultrasound measurements have been performed in aqueous solutions of pentoses, hexoses, methylpyranosides, and disaccharides as a function of molality of carbohydrate (0-0.3 mol kg-1). Partial molar volumes, partial molar isentropic compressibilities, and hydration numbers have been calcu

  18. Measurement of central corneal thickness using ultrasound pachymetry and Orbscan II in normal eyes

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Sadoughi

    2015-01-01

    Conclusion: Orbscan II has good correlation with ultrasound pachymetry for measurement of CCT in normal eyes; however Orbscan II should not be used to evaluate corneal thickness before keratorefractive surgeries, as it tends to overestimate corneal thickness and may result in undesirable, low residual stromal thickness.

  19. A Multidimensional Investigation of Children's /r/ Productions: Perceptual, Ultrasound, and Acoustic Measures

    Science.gov (United States)

    Klein, Harriet B.; McAllister Byun, Tara; Davidson, Lisa; Grigos, Maria I.

    2013-01-01

    Purpose: This study explored relationships among perceptual, ultrasound, and acoustic measurements of children's correct and misarticulated /r/ sounds. Longitudinal data documenting changes across these parameters were collected from 2 children who acquired /r/ over a period of intervention and were compared with data from children with typical…

  20. STEREOCHEMICAL ASPECTS OF HYDRATION OF CARBOHYDRATES IN AQUEOUS-SOLUTIONS .3. DENSITY AND ULTRASOUND MEASUREMENTS

    NARCIS (Netherlands)

    GALEMA, SA; HOILAND, H

    1991-01-01

    Density and ultrasound measurements have been performed in aqueous solutions of pentoses, hexoses, methylpyranosides, and disaccharides as a function of molality of carbohydrate (0-0.3 mol kg-1). Partial molar volumes, partial molar isentropic compressibilities, and hydration numbers have been

  1. Validation of Navigation Ultrasound for Clavicular Length Measurement

    DEFF Research Database (Denmark)

    Høj, Anders Thorsmark; Villa, Chiara; Christensen, Ole M

    2017-01-01

    Accurate clavicular length measurement is considered important for the selection of patients requiring surgical treatment after a midclavicular fracture. As radiographic length measurements can be inaccurate to varying degrees, new measurement methods are needed. Use of novel technology, navigati...

  2. Exploration Analysis of Carbon Dioxide Levels and Ultrasound Measures of the Eye During ISS Missions

    Science.gov (United States)

    Young, M.; Mason, S.; Schaefer, C.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Coble, C.; Gruschkus, S.; Law, J.; Alexander, D.; hide

    2016-01-01

    Enhanced screening for the Visual Impairment/Intracranial Pressure (VIIP) Syndrome, including in-flight ultrasound, was implemented in 2010 to better characterize the changes in vision observed in some long-duration crewmembers. Suggested possible risk factors for VIIP include cardiovascular changes, diet, anatomical and genetic factors, and environmental conditions. As a potent vasodilator, carbon dioxide (CO (sub 2)), which is chronically elevated on the International Space Station (ISS) relative to typical indoor and outdoor ambient levels on Earth, seems a plausible contributor to VIIP. In an effort to understand the possible associations between CO (sub 2) and VIIP, this study analyzes the relationship between ambient CO (sub 2) levels on ISS and ultrasound measures of the eye obtained from ISS fliers. CO (sub 2) measurements will be pulled directly from Operational Data Reduction Complex for the Lab and Node 3 major constituent analyzers (MCAs) on ISS or from sensors located in the European Columbus module, as available. CO (sub 2) measures between ultrasound sessions will be summarized using standard time series class metrics in MATLAB including time-weighted means and variances. Cumulative CO (sub 2) exposure metrics will also be developed. Regression analyses will be used to quantify the relationships between the CO (sub 2) metrics and specific ultrasound measures. Generalized estimating equations will adjust for the repeated measures within individuals. Multiple imputation techniques will be used to adjust for any possible biases in missing data for either CO (sub 2) or ultrasound measures. These analyses will elucidate the possible relationship between CO (sub 2) and changes in vision and also inform future analysis of inflight VIIP data.

  3. A comparison of portable ultrasound and fully-equipped clinical ultrasound unit in the thyroid size measurement of the Indo-Pacific bottlenose dolphin.

    Directory of Open Access Journals (Sweden)

    Brian C W Kot

    Full Text Available Measurement of thyroid size and volume is a useful clinical parameter in both human and veterinary medicine, particularly for diagnosing thyroid diseases and guiding corrective therapy. Procuring a fully-equipped clinical ultrasound unit (FCUS may be difficult in most veterinary settings. The present study evaluated the inter-equipment variability in dolphin thyroid ultrasound measurements between a portable ultrasound unit (PUS and a FCUS; for both units, repeatability was also assessed. Thyroid ultrasound examinations were performed on 15 apparently healthy bottlenose dolphins with both PUS and FCUS under identical scanning conditions. There was a high level of agreement between the two ultrasound units in dolphin thyroid measurements (ICC = 0.859-0.976. A high intra-operator repeatability in thyroid measurements was found (PUS: ICC = 0.854-0.984, FCUS: ICC = 0.709-0.954. As a conclusion, no substantial inter-equipment variability was found between PUS and FCUS in dolphin thyroid size measurements under identical scanning conditions, supporting further application of PUS for quantitative analyses of dolphin thyroid gland in both research and clinical practices at aquarium settings.

  4. A comparison of portable ultrasound and fully-equipped clinical ultrasound unit in the thyroid size measurement of the Indo-Pacific bottlenose dolphin.

    Science.gov (United States)

    Kot, Brian C W; Ying, Michael T C; Brook, Fiona M

    2012-01-01

    Measurement of thyroid size and volume is a useful clinical parameter in both human and veterinary medicine, particularly for diagnosing thyroid diseases and guiding corrective therapy. Procuring a fully-equipped clinical ultrasound unit (FCUS) may be difficult in most veterinary settings. The present study evaluated the inter-equipment variability in dolphin thyroid ultrasound measurements between a portable ultrasound unit (PUS) and a FCUS; for both units, repeatability was also assessed. Thyroid ultrasound examinations were performed on 15 apparently healthy bottlenose dolphins with both PUS and FCUS under identical scanning conditions. There was a high level of agreement between the two ultrasound units in dolphin thyroid measurements (ICC = 0.859-0.976). A high intra-operator repeatability in thyroid measurements was found (PUS: ICC = 0.854-0.984, FCUS: ICC = 0.709-0.954). As a conclusion, no substantial inter-equipment variability was found between PUS and FCUS in dolphin thyroid size measurements under identical scanning conditions, supporting further application of PUS for quantitative analyses of dolphin thyroid gland in both research and clinical practices at aquarium settings.

  5. Protection against high intravascular pressure in giraffe legs

    DEFF Research Database (Denmark)

    Petersen, Karin K; Hørlyck, Arne; Østergaard, Kristine Hovkjær

    2013-01-01

    The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination....... All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure....... revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along...

  6. Current concepts in the management of disseminated intravascular coagulation.

    Science.gov (United States)

    Thachil, Jecko; Toh, Cheng Hock

    2012-04-01

    Disseminated Intravascular Coagulation is a clinicopathological syndrome where widespread intravascular coagulation occurs in response to an inciting process. The pathophysiology for this disorder is complex with an important role for thrombin, the central regulator of the coagulation process. Since the clinical spectrum of DIC is variable due to its dynamic nature, the laboratory diagnosis should ideally be not based on a single marker or an isolated set of results. The treatment should primary focus on the management of the underlying triggering condition with blood products used as resuscitative measures. Newer therapeutic modalities have been recently tried with success although the management of DIC still remains a major challenge.

  7. Non-invasive Measurement of Pressure Gradients in Pulsatile Flow using Ultrasound

    DEFF Research Database (Denmark)

    Olesen, Jacob Bjerring; Traberg, Marie Sand; Pihl, Michael Johannes

    2013-01-01

    approach. Pressure gradients are calculated from the measured velocity fields using the Navier-Stokes equation. Velocity fields are measured during constant and pulsating flow on a carotid bifurcation phantom and on a common carotid artery in-vivo. Scanning is performed with a 5 MHz BK8670 linear......This paper demonstrates how pressure gradients in a pulsatile flow environment can be measured non-invasively using ultrasound. The proposed method relies on vector velocity fields acquired from ultrasound data. 2-D flow data are acquired at 18-23 frames/sec using the Transverse Oscillation...... transducer using a BK Medical 2202 UltraView Pro Focus scanner. The calculated pressure gradients are validated through a finite element simulation of the constant flow model. The geometry of the flow simulation model is reproduced using MRI data, thereby providing identical flow domains in measurement...

  8. 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.

  9. Measurement of Central Corneal Thickness Using Ultrasound Pachymetry and Orbscan II in Normal Eyes

    Science.gov (United States)

    Sadoughi, Mohammad Mehdi; Einollahi, Bahram; Einollahi, Neda; Rezaei, Javad; Roshandel, Danial; Feizi, Sepehr

    2015-01-01

    Purpose: To compare ultrasound pachymetry and Orbscan II for measurement of central corneal thickness (CCT) in normal eyes. Methods: The current study was performed at Labbafinejad Medical Center (LMC), Tehran, Iran. Three hundred eyes from 150 healthy individuals referred for keratorefractive surgery were assessed first by Orbscan II and then by ultrasound pachymetry, and CCT values were recorded and compared. Results: Overall, Orbscan II overestimated CCT as compared to ultrasound pachymetry by about 2.4% (mean values 547.6 ± 34.7 versus 534.8 ± 34.7, respectively, P < 0.001). The difference was more significant when CCT was less than 500 microns (mean values 493.2 ± 16.9 versus 479.9 ± 15.6, mean overestimation: 2.6%, P < 0.001). There was good linear correlation between the two methods (Pearson's correlation r = 0.968, P < 0.0001). Conclusion: Orbscan II has good correlation with ultrasound pachymetry for measurement of CCT in normal eyes; however Orbscan II should not be used to evaluate corneal thickness before keratorefractive surgeries, as it tends to overestimate corneal thickness and may result in undesirable, low residual stromal thickness. PMID:26005545

  10. Time-resolved measurement of bubble cavitation by using power Doppler ultrasound image

    Science.gov (United States)

    Koda, Ren; Izumi, Yosuke; Nagai, Hayato; Yamakoshi, Yoshiki

    2017-04-01

    In this study, a novel measurement method for a secondary ultrasound wave irradiated by microbubble cavitation is proposed. High-intensity ultrasound (h-US, 1.0–1.5 MPa), which produces bubble cavitation, is irradiated with a fixed time delay after introducing imaging US, whose frequency is different from that of the h-US. The bubble cavitation signal (BCS) is detected by the signal-processing unit of an ultrasound power Doppler imaging instrument. By this method, both a spatially resolved bubble image (S-image) and the temporal transition of the BCS (T-image) are monitored simultaneously. A feature of the method is that the BCS is observed in situ with sub-µs time resolution. The accuracy of the method is evaluated and it is found that the maximum deviation of the amplitude of the simulated BCS is 4.80%. This method is applied to measure the BCS of ultrasound contrast agent microbubbles. As a result, the dependence of the inherent temporal transition of the BCS on the sound pressure of the h-US (0.6–1.2 MPa) is observed.

  11. Ultrasound contrast agents for ultrasound molecular imaging.

    Science.gov (United States)

    Tranquart, F; Arditi, M; Bettinger, T; Frinking, P; Hyvelin, J M; Nunn, A; Pochon, S; Tardy, I

    2014-11-01

    Ultrasound is a real-time imaging technique which is widely used in many clinical applications for its capacity to provide anatomic information with high spatial and temporal resolution. The advent of ultrasound contrast agents in combination with contrast-specific imaging modes has given access to perfusion assessments at an organ level, leading to an improved diagnostic accuracy. More recently, the development of biologically-targeted ultrasound contrast agents has expanded the role of ultrasound even further into molecular imaging applications. Ultrasound molecular imaging can be used to visualize the expression of intravascular markers, and to assess their local presence over time and/or during therapeutic treatment. Major applications are in the field of inflammation and neoangiogenesis due to the strictly intravascular presence of microbubbles. Various technologies have been investigated for attaching the targeting moiety to the shell from simple biotin-avidin constructs to more elaborated insertion within the shell through attachment to PEG residues. This important improvement has allowed a clinical translation of initial pre-clinical investigations, opening the way for an early detection and an accurate characterization of lesions in patients. The combination of anatomic, functional and molecular information/data provided by contrast ultrasound is a powerful tool which is still in its infancy due to the lack of agents suitable for clinical use. The advantages of ultrasound techniques combined with the molecular signature of lesions will represent a significant advance in imaging in the field of personalized medicine. © Georg Thieme Verlag KG Stuttgart · New York.

  12. 产科急性弥漫性血管内凝血的临床表现及治疗措施分析%Acute Disseminated Intravascular Coagulation in Obstetrics Clinical Manifestations and Treatment Measures

    Institute of Scientific and Technical Information of China (English)

    黄意锋

    2013-01-01

    目的:分析产科急诊弥漫性血管内凝血的临床表现及治疗措施。方法:抽取本院治疗的18例急性弥漫性血管内凝血孕妇的临床资料进行回顾性分析。结果:经分析,这些患者的临床中表现主要为:大出血,并且血液不凝。经过积极治疗,其中包括治疗原发病、补充血液以及手术等,15例成功抢救,3例死亡,其中12例切除子宫,其抢救成功率高达83.3%。结论:产科患者一旦发现出血症状,应立即采取措施进行治疗。%Objective:Analysis of emergency obstetric disseminated intravascular coagulation in the clinical presentation and treatment measures.Methods: Collected from this hospital treatment of 18 cases of acute disseminated intravascular coagulation in pregnant women were retrospectively reviewed the clinical data analysis.Results:Through analysis, these patients in the clinical manifestations are mainly:bleeding, and blood coagulation.After active treatment, including treatment of primary disease, supplement blood as well as operation, 15 cases of successful rescue, 3 patients died, including 12 cases of hysterectomy, rescue success rate as high as 83.3%.Conclusion: Obstetric patients once found bleeding symptoms, immediate measures should be taken for treatment.

  13. Comparison of sound speed measurements on two different ultrasound tomography devices

    OpenAIRE

    Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Sherman, Mark; Gierach, Gretchen; Malyarenko, Antonina

    2014-01-01

    Ultrasound tomography (UST) employs sound waves to produce three-dimensional images of breast tissue and precisely measures the sound speed of breast tissue composition. High breast density is a strong breast cancer risk factor and sound speed is directly proportional to breast density. UST provides a quantitative measure of breast density based on three-dimensional imaging without compression, thereby overcoming the shortcomings of many other imaging modalities. The quantitative nature of th...

  14. The age-related advancement of arterial disease measured by Doppler ultrasound diastolic flow analysis.

    Science.gov (United States)

    Terenzi, T; Gallagher, D; DeMeersman, R; Beadle, E; Muller, D

    1993-10-01

    To quantify by A-mode Doppler sonography the age-related progression of arterial disease so that age dependent normal values may be established for the screening Doppler peripheral arterial exam. Arterial distensibility was assessed by A-mode Doppler diastolic flow analysis as a measure of atherogenesis. These values will increase the sensitivity and decrease the incidence of false-positive results when the Doppler exam is utilized to differentially diagnosis vascular and sciatic neurogenic claudication. The relationship between age and results from the standard ankle/arm index ultrasound pneumatic cuff examination was also analyzed. A two by three analysis of variance with orthogonal Helmert contrast codes and simple linear regression analysis was utilized for this cross-sectionally designed investigation. The dependent measures of diastolic flow analysis and ankle/arm pressure index were obtained within three nested successively increasing age groups. Chiropractic office. Studied were a total of 90 sedentary nonsmoking subjects, aged 23-79 yr, all of whom had normally accepted levels of serum glucose, cholesterol and blood pressure. Subjects were screened for evidence of aortic coarctation, myocardial infarction, tachyarrhythmia, aortic valve stenosis, mitral prolapse, hypertension, hypercholesterolemia, diabetes and peripheral occlusive arterial disease. Anthropometric measurements and percent body fat were obtained. A predictive oxygen consumption bike ergometer test was performed to obtain aerobic capacity. The commonly utilized standard ankle/arm index ultrasound pneumatic cuff examination and arterial diastolic flow analysis were performed with A-mode Doppler ultrasound on all subjects. These results demonstrate that a significant inverse linear relationship exists between aging and arterial compliance (p < .0001) in our population. Diastolic flow analysis had a greater sensitivity to arterial disease than the standard ankle/arm index ultrasound pneumatic

  15. Ultrasound Estimated Bladder Weight and Measurement of Bladder Wall Thickness-Useful Noninvasive Methods for Assessing the Lower Urinary Tract?

    NARCIS (Netherlands)

    E. Bright; M. Oelke; A. Tubaro; P. Abrams

    2010-01-01

    Purpose: In the last decade interest has arisen in the use of ultrasound derived measurements of bladder wall thickness, detrusor wall thickness and ultrasound estimated bladder weight as potential diagnostic tools for conditions known to induce detrusor hypertrophy. However, to date such measuremen

  16. Central Venous Catheter Intravascular Malpositioning: Causes, Prevention, Diagnosis, and Correction.

    Science.gov (United States)

    Roldan, Carlos J; Paniagua, Linda

    2015-09-01

    Despite the level of skill of the operator and the use of ultrasound guidance, central venous catheter (CVC) placement can result in CVC malpositioning, an unintended placement of the catheter tip in an inadequate vessel. CVC malpositioning is not a complication of central line insertion; however, undiagnosed CVC malpositioning can be associated with significant morbidity and mortality. The objectives of this review were to describe factors associated with intravascular malpositioning of CVCs inserted via the neck and chest and to offer ways of preventing, identifying, and correcting such malpositioning. A literature search of PubMed, Cochrane Library, and MD Consult was performed in June 2014. By searching for "Central line malposition" and then for "Central venous catheters intravascular malposition," we found 178 articles written in English. Of those, we found that 39 were relevant to our objectives and included them in our review. According to those articles, intravascular CVC malpositioning is associated with the presence of congenital and acquired anatomical variants, catheter insertion in left thoracic venous system, inappropriate bevel orientation upon needle insertion, and patient's body habitus variants. Although plain chest radiography is the standard imaging modality for confirming catheter tip location, signs and symptoms of CVC malpositioning even in presence of normal or inconclusive conventional radiography findings should prompt the use of additional diagnostic methods to confirm or rule out CVC malpositioning. With very few exceptions, the recommendation in cases of intravascular CVC malpositioning is to remove and relocate the catheter. Knowing the mechanisms of CVC malpositioning and how to prevent, identify, and correct CVC malpositioning could decrease harm to patients with this condition.

  17. Central Venous Catheter Intravascular Malpositioning: Causes, Prevention, Diagnosis, and Correction

    Directory of Open Access Journals (Sweden)

    Carlos J. Roldan

    2015-10-01

    Full Text Available Despite the level of skill of the operator and the use of ultrasound guidance, central venous catheter (CVC placement can result in CVC malpositioning, an unintended placement of the catheter tip in an inadequate vessel. CVC malpositioning is not a complication of central line insertion; however, undiagnosed CVC malpositioning can be associated with significant morbidity and mortality. The objectives of this review were to describe factors associated with intravascular malpositioning of CVCs inserted via the neck and chest and to offer ways of preventing, identifying, and correcting such malpositioning. A literature search of PubMed, Cochrane Library, and MD Consult was performed in June 2014. By searching for “Central line malposition” and then for “Central venous catheters intravascular malposition,” we found 178 articles written in English. Of those, we found that 39 were relevant to our objectives and included them in our review. According to those articles, intravascular CVC malpositioning is associated with the presence of congenital and acquired anatomical variants, catheter insertion in left thoracic venous system, inappropriate bevel orientation upon needle insertion, and patient’s body habitus variants. Although plain chest radiography is the standard imaging modality for confirming catheter tip location, signs and symptoms of CVC malpositioning even in presence of normal or inconclusive conventional radiography findings should prompt the use of additional diagnostic methods to confirm or rule out CVC malpositioning. With very few exceptions, the recommendation in cases of intravascular CVC malpositioning is to remove and relocate the catheter. Knowing the mechanisms of CVC malpositioning and how to prevent, identify, and correct CVC malpositioning could decrease harm to patients with this condition.

  18. The influence of dairy consumption and physical activity on ultrasound bone measurements in Flemish children.

    Science.gov (United States)

    De Smet, Stephanie; Michels, Nathalie; Polfliet, Carolien; D'Haese, Sara; Roggen, Inge; De Henauw, Stefaan; Sioen, Isabelle

    2015-03-01

    The study's aim was to analyse whether children's bone status, assessed by calcaneal ultrasound measurements, is influenced by dairy consumption and objectively measured physical activity (PA). Moreover, the interaction between dairy consumption and PA on bone mass was studied. Participants of this cross-sectional study were 306 Flemish children (6-12 years). Body composition was measured with air displacement plethysmography (BodPod), dairy consumption with a Food Frequency Questionnaire, PA with an accelerometer (only in 234 of the 306 children) and bone mass with quantitative ultrasound, quantifying speed of sound (SOS), broadband ultrasound attenuation (BUA) and Stiffness Index (SI). Regression analyses were used to study the associations between dairy consumption, PA, SOS, BUA and SI. Total dairy consumption and non-cheese dairy consumption were positively associated with SOS and SI, but no significant association could be demonstrated with BUA. In contrast, milk consumption, disregarding other dairy products, had no significant effect on calcaneal bone measurements. PA [vigorous PA, moderate to vigorous physical activity (MVPA) and counts per minute] was positively associated and sedentary time was negatively associated with BUA and SI, but no significant influence on SOS could be detected. Dairy consumption and PA (sedentary time and MVPA) did not show any interaction influencing bone measurements. In conclusion, even at young age, PA and dairy consumption positively influence bone mass. Promoting PA and dairy consumption in young children may, therefore, maximize peak bone mass, an important protective factor against osteoporosis later in life.

  19. Third trimester ultrasound soft-tissue measurements accurately predicts macrosomia.

    Science.gov (United States)

    Maruotti, Giuseppe Maria; Saccone, Gabriele; Martinelli, Pasquale

    2017-04-01

    To evaluate the accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia. Electronic databases were searched from their inception until September 2015 with no limit for language. We included only studies assessing the accuracy of sonographic measurements of fetal soft tissue in the abdomen or thigh in the prediction of macrosomia  ≥34 weeks of gestation. The primary outcome was the accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia. We generated the forest plot for the pooled sensitivity and specificity with 95% confidence interval (CI). Additionally, summary receiver-operating characteristics (ROC) curves were plotted and the area under the curve (AUC) was also computed to evaluate the overall performance of the diagnostic test accuracy. Three studies, including 287 singleton gestations, were analyzed. The pooled sensitivity of sonographic measurements of abdominal or thigh fetal soft tissue in the prediction of macrosomia was 80% (95% CI: 66-89%) and the pooled specificity was 95% (95% CI: 91-97%). The AUC for diagnostic accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia was 0.92 and suggested high diagnostic accuracy. Third-trimester sonographic measurements of fetal soft tissue after 34 weeks may help to detect macrosomia with a high degree of accuracy. The pooled detection rate was 80%. A standardization of measurements criteria, reproducibility, building reference charts of fetal subcutaneous tissue and large studies to assess the optimal cutoff of fetal adipose thickness are necessary before the introduction of fetal soft-tissue markers in the clinical practice.

  20. Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound

    Science.gov (United States)

    Hargens, A. R.

    1998-01-01

    Prevention of secondary brain injuries following head can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop (PPLL) devise, which was developed and patented, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year one studies involved instrument improvements and measurement of altered intracranial distance with altered ICP in fresh cadavera. Our software was improved to facilitate future studies of normal subjects and trauma patients. Our bench studies proved that PPLL output correlated highly with changes in path length across a model cranium. Cadaveric studies demonstrated excellent compact, noninvasive devise for monitoring changes in intracranial distance may aid in the early detection of elevated ICP, decreasing risk of secondary brain injury and infection, and returning head-injured patients to duty.

  1. Hybrid Segmentation of Vessels and Automated Flow Measures in In-Vivo Ultrasound Imaging

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Martins, Bo; Hansen, Kristoffer Lindskov

    2016-01-01

    expert segmentations. The flowrig results also demonstrated that the PSVs measured from VFI had a mean relative error of 14.5% in comparison with the actual PSVs. The error for the PSVs measured from spectral Doppler was 29.5%, indicating that VFI is 15% more precise than spectral Doppler in PSV...... method implements automated VFI flow measures such as peak systolic velocity (PSV) and volume flow. An evaluation of the performance of the segmentation algorithm relative to expert manual segmentation of 60 frames randomly chosen from 6 ultrasound sequences (10 frame randomly chosen from each sequence...... measurement....

  2. Limited Accuracy of Colour Doppler Ultrasound Dynamic Tissue Perfusion Measurement in Diabetic Adults

    Science.gov (United States)

    Stoperka, Felix; Karger, Claudia

    2016-01-01

    Dynamic tissue perfusion measurement (DTPM) is a pre-described and available method in pediatric ultrasound to quantify tissue perfusion in renal Doppler ultrasound by particular video analysis software. This study evaluates DTPM during single and between repeated visits after 6 months, calibrates repeated DTPM within different region of interest (ROI) and compares DTPM with kidney function markers in adult patients with early diabetic nephropathy (n = 17). During repeated measurements, no association of readings at the same patients in the same (n = 3 readings) as well as repeated visit (n = 2 visits) could be retrieved. No association between DTPM, MDRD-GFR, albuminuria, age and duration of diabetes was observed. These negative results are presumably related to inconsistency of DTPM due to non-fixed ROI position as could be shown in calibrating series. Further development of the method should be performed to enable reproducible DTPM readings in adults. PMID:28033403

  3. Carotid Artery Segmentation in Ultrasound Images and Measurement of Intima-Media Thickness

    Directory of Open Access Journals (Sweden)

    Vaishali Naik

    2013-01-01

    Full Text Available Background. The segmentation of the common carotid artery (CCA wall is imperative for the determination of the intima-media thickness (IMT on B-mode ultrasound (US images. The IMT is considered an important indicator in the evaluation of the risk for the development of atherosclerosis. In this paper, authors have discussed the relevance of measurements in clinical practices and the challenges that one has to face while approaching the segmentation of carotid artery on ultrasound images. The paper presents an overall review of commonly used methods for the CCA segmentation and IMT measurement along with the different performance metrics that have been proposed and used for performance validation. Summary and future directions are given in the conclusion.

  4. Accurate acoustic power measurement for low-intensity focused ultrasound using focal axial vibration velocity

    Science.gov (United States)

    Tao, Chenyang; Guo, Gepu; Ma, Qingyu; Tu, Juan; Zhang, Dong; Hu, Jimin

    2017-07-01

    Low-intensity focused ultrasound is a form of therapy that can have reversible acoustothermal effects on biological tissue, depending on the exposure parameters. The acoustic power (AP) should be chosen with caution for the sake of safety. To recover the energy of counteracted radial vibrations at the focal point, an accurate AP measurement method using the focal axial vibration velocity (FAVV) is proposed in explicit formulae and is demonstrated experimentally using a laser vibrometer. The experimental APs for two transducers agree well with theoretical calculations and numerical simulations, showing that AP is proportional to the square of the FAVV, with a fixed power gain determined by the physical parameters of the transducers. The favorable results suggest that the FAVV can be used as a valuable parameter for non-contact AP measurement, providing a new strategy for accurate power control for low-intensity focused ultrasound in biomedical engineering.

  5. Cranial Ultrasound/Head Ultrasound

    Science.gov (United States)

    ... sickle cell disease. It is also used to measure conditions affecting blood flow to and within the brain, such as: Stenosis : ... saved. Doppler ultrasound, a special application of ultrasound, measures ... represent the flow of blood through the blood vessels. top of ...

  6. Colonic wall thickness measured by ultrasound: striking differences in patients with cystic fibrosis versus healthy controls.

    OpenAIRE

    1997-01-01

    BACKGROUND: Colonic strictures represent an advanced stage of fibrosing colonopathy in patients with cystic fibrosis. AIMS: To clarify whether ultrasonography can identify patients with an early stage of fibrosing colonopathy and to determine clinical factors that influence bowel wall thickening. PATIENTS: Ninety patients with cystic fibrosis, median age 10 years, and 46 healthy controls, median age 13 years, were investigated. METHODS: Bowel wall thickness was measured by ultrasound in a pro...

  7. Exploratory Analysis of Carbon Dioxide Levels and Ultrasound Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Young, M.; Mason, S.; Coble, C.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Law. J.; Alexander, D.; Ryder, V. Myers; hide

    2016-01-01

    Carbon dioxide (CO2) levels on ISS have typically averaged 2.3 to 5.3mm Hg, with large fluctuations occurring over periods of hours and days. CO2 has effects on cerebral vascular tone, resulting in vasodilation and alteration of cerebral blood flow(CBF). Increased CBF leads to elevated intracranial pressure(ICP), which is a factor leading to visual disturbance, headaches, and other central nervous system symptoms. Ultrasound of the optic nerve provides a surrogate measurement of ICP. Inflight ultrasounds were implemented as an enhanced screening tool for the Visual Impairment/Intracranial Pressure (VIIP) Syndrome. This analysis examines the relationships between ambient CO2 levels on ISS and ultrasound measures of the eye in an effort to understand how CO2 may be associated with VIIP and to inform future analysis of inflight VIIP data. Results as shown in Figure2, there was a large timeframe where CO2 readings were removed due to sensor fault errors(see Limitations), from June 2011 to January 2012. After extensive cleaning of the CO2 data, metrics for all of the data were calculated (Table2). Preliminary analyses showed possible associations between variability measures of CO2 and AP diameter (Figure3),and average CO2 exposure and ONSD(Figure4). Adjustments for multiple comparisons were not made due to the exploratory nature of the analysis.

  8. Duplex ultrasound

    Science.gov (United States)

    Vascular ultrasound; Peripheral vascular ultrasound ... A duplex ultrasound combines: Traditional ultrasound: This uses sound waves that bounce off blood vessels to create pictures. Doppler ultrasound: This ...

  9. Quantification of ultrasound correlation-based flow velocity mapping and edge velocity gradient measurement.

    Science.gov (United States)

    Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F

    2013-10-01

    This study investigated the use of ultrasound speckle decorrelation- and correlation-based lateral speckle-tracking methods for transverse and longitudinal blood velocity profile measurement, respectively. By studying the blood velocity gradient at the vessel wall, vascular wall shear stress, which is important in vascular physiology as well as the pathophysiologic mechanisms of vascular diseases, can be obtained. Decorrelation-based blood velocity profile measurement transverse to the flow direction is a novel approach, which provides advantages for vascular wall shear stress measurement over longitudinal blood velocity measurement methods. Blood flow velocity profiles are obtained from measurements of frame-to-frame decorrelation. In this research, both decorrelation and lateral speckle-tracking flow estimation methods were compared with Poiseuille theory over physiologic flows ranging from 50 to 1000 mm/s. The decorrelation flow velocity measurement method demonstrated more accurate prediction of the flow velocity gradient at the wall edge than the correlation-based lateral speckle-tracking method. The novelty of this study is that speckle decorrelation-based flow velocity measurements determine the blood velocity across a vessel. In addition, speckle decorrelation-based flow velocity measurements have higher axial spatial resolution than Doppler ultrasound measurements to enable more accurate measurement of blood velocity near a vessel wall and determine the physiologically important wall shear.

  10. Central Corneal Thickness Measurement by Ultrasound versus Orbscan II

    Directory of Open Access Journals (Sweden)

    Amir Faramarzi

    2008-12-01

    Full Text Available

    PURPOSE: To compare Orbscan II and ultrasonic pachymetry for measurement of central corneal thickness (CCT in eyes scheduled for keratorefractive surgery. METHODS: CCT was measured using Orbscan II (Bausch & Lomb, USA and then by ultrasonic pachymetry (Tomey SP-3000, Tomey Ltd, Japan in 100 eyes of 100 patients with no history of ocular surgery scheduled for excimer laser refractive surgery. RESULTS: Mean CCT was 544.7±35.5 (range 453-637 µm by ultrasonic pachymetry versus 546.9±41.6 (range 435-648 µm measured by Orbscan II applying an acoustic factor of 0.92 (P=0.14. The standard deviation of measurements was greater with Orbscan pachymetry but the difference was not statistically significant. CONCLUSION: CCT measurements by Orbscan II (applying an acoustic factor and by ultrasonic pachymetry are not significantly different; however, when CCT readings by Orbscan II are in the lower range, it is advisable to recheck the measurements using ultrasonic pachymetry.

  1. Toward predicting tensile strength of pharmaceutical tablets by ultrasound measurement in continuous manufacturing.

    Science.gov (United States)

    Razavi, Sonia M; Callegari, Gerardo; Drazer, German; Cuitiño, Alberto M

    2016-06-30

    An ultrasound measurement system was employed as a non-destructive method to evaluate its reliability in predicting the tensile strength of tablets and investigate the benefits of incorporating it in a continuous line, manufacturing solid dosage forms. Tablets containing lactose, acetaminophen, and magnesium stearate were manufactured continuously and in batches. The effect of two processing parameters, compaction force and level of shear strain were examined. Young's modulus and tensile strength of tablets were obtained by ultrasound and diametrical mechanical testing, respectively. It was found that as the blend was exposed to increasing levels of shear strain, the speed of sound in the tablets decreased and the tablets became both softer and mechanically weaker. Moreover, the results indicate that two separate tablet material properties (e.g., relative density and Young's modulus) are necessary in order to predict tensile strength. A strategy for hardness prediction is proposed that uses the existing models for Young's modulus and tensile strength of porous materials. Ultrasound testing was found to be very sensitive in differentiating tablets with similar formulation but produced under different processing conditions (e.g., different level of shear strain), thus, providing a fast, and non-destructive method for hardness prediction that could be incorporated to a continuous manufacturing process.

  2. Quantitative muscle ultrasound measures rapid declines over time in children with SMA type 1.

    Science.gov (United States)

    Ng, Kay W; Connolly, Anne M; Zaidman, Craig M

    2015-11-15

    Muscles are small in spinal muscular atrophy (SMA). It is not known if muscle size changes over time in SMA type 1. We quantified changes over time in muscle size and echointensity during two repeated ultrasound examinations of unilateral proximal (biceps brachii/brachialis and quadriceps) and distal (anterior forearm flexors and tibialis anterior) muscles in three children with SMA type 1. We compared muscle thickness (MT) to body weight-dependent normal reference values. Children were 1, 6, and 11months old at baseline and had 2, 2 and 4 months between ultrasound examinations, respectively. At baseline, MT was normal for weight in all muscles except an atrophic quadriceps in the oldest child. MT decreased and echointensity increased (worsened) over time. At follow up, MT was below normal for weight in the quadriceps in all three children, in the biceps/brachioradialis in two, and in the anterior forearm in one. Tibialis anterior MT remained normal for weight in all three children. Muscle echointensity increased over time in all muscles and, on average, more than doubled in two children. In children with SMA type 1, muscle atrophies and becomes hyperechoic over time. Quantitative muscle ultrasound measures disease progression in SMA type 1 that warrants additional study in more children. Copyright © 2015. Published by Elsevier B.V.

  3. Ultrasound Velocity Measurements in High-Chromium Steel Under Plastic Deformation

    Science.gov (United States)

    Lunev, Aleksey; Bochkareva, Anna; Barannikova, Svetlana; Zuev, Lev

    2016-04-01

    In the present study, the variation of the propagation velocity of ultrasound in the plastic deformation of corrosion-resistant high-chromium steel 40X13 with ferrite-carbide (delivery status), martensitic (quenched) and sorbitol (after high-temperature tempering) structures have beem studied/ It is found that each state shows its view of the loading curve. In the delivery state diagram loading is substantially parabolic throughout, while in the martensitic state contains only linear strain hardening step and in the sorbitol state the plastic flow curve is three-step. The velocity of ultrasonic surface waves (Rayleigh waves) was measured simultaneously with the registration of the loading curve in the investigated steel in tension. It is shown that the dependence of the velocity of ultrasound in active loading is determined by the law of plastic flow, that is, the staging of the corresponding diagram of loading. Structural state of the investigated steel is not only changing the type of the deformation curve under uniaxial tension, but also changes the nature of ultrasound speed of deformation.

  4. [Precision of arthroscopic surgeons using ultrasound for the first time to measure tendon structures].

    Science.gov (United States)

    Erquicia, J I; Tey, M; Doreste, J L; Monllau, J C; Centenera, J M; Altisench, J M

    2016-01-01

    The precision of a group of arthroscopic surgeons using ultrasound for the first time was assessed when measuring shoulder and hip tendon structures. Twenty-two students and 3 professors participated in a one-day theoretical-practical course. Two measurement rounds were conducted, during which each student identified the greater and lesser axes and the cross-sectional area of the biceps tendon, the supraspinous depth, as well as the lesser and greater axes and the cross-sectional area of the iliac psoas. The mean of the two measurements made by each of the course professors was considered as the reference value. When the 2 measurements made by each of the students of each of the structures were assessed, no significant correlation was found in any of the cases, with a p 0.05. With the exception of the cross-sectional area of the biceps, where there was a significant undersizing of the structure, in the remaining 7 measurements a marked trend to oversize the structures was seen in both the first and second measurements, with a high statistical significance (p 0.05). Ultrasound is a useful method through which arthroscopic surgeons can identify structures. However, the marked trend to oversize structures compared to the reference values leads to think that the training courses and the daily practice are essential to improve the method.

  5. Pulse-echo ultrasound transit time spectroscopy: A comparison of experimental measurement and simulation prediction.

    Science.gov (United States)

    Wille, Marie-Luise; Almualimi, Majdi A; Langton, Christian M

    2016-01-01

    Considering ultrasound propagation through complex composite media as an array of parallel sonic rays, a comparison of computer-simulated prediction with experimental data has previously been reported for transmission mode (where one transducer serves as transmitter, the other as receiver) in a series of 10 acrylic step-wedge samples, immersed in water, exhibiting varying degrees of transit time inhomogeneity. In this study, the same samples were used but in pulse-echo mode, where the same ultrasound transducer served as both transmitter and receiver, detecting both 'primary' (internal sample interface) and 'secondary' (external sample interface) echoes. A transit time spectrum was derived, describing the proportion of sonic rays with a particular transit time. A computer simulation was performed to predict the transit time and amplitude of various echoes created, and compared with experimental data. Applying an amplitude-tolerance analysis, 91.7% ± 3.7% of the simulated data were within ±1 standard deviation of the experimentally measured amplitude-time data. Correlation of predicted and experimental transit time spectra provided coefficients of determination (R(2)%) ranging from 100.0% to 96.8% for the various samples tested. The results acquired from this study provide good evidence for the concept of parallel sonic rays. Furthermore, deconvolution of experimental input and output signals has been shown to provide an effective method to identify echoes otherwise lost due to phase cancellation. Potential applications of pulse-echo ultrasound transit time spectroscopy include improvement of ultrasound image fidelity by improving spatial resolution and reducing phase interference artefacts.

  6. Design and implementation of a smartphone-based portable ultrasound pulsed-wave Doppler device for blood flow measurement.

    Science.gov (United States)

    Huang, Chih-Chung; Lee, Po-Yang; Chen, Pay-Yu; Liu, Ting-Yu

    2012-01-01

    Blood flow measurement using Doppler ultrasound has become a useful tool for diagnosing cardiovascular diseases and as a physiological monitor. Recently, pocket-sized ultrasound scanners have been introduced for portable diagnosis. The present paper reports the implementation of a portable ultrasound pulsed-wave (PW) Doppler flowmeter using a smartphone. A 10-MHz ultrasonic surface transducer was designed for the dynamic monitoring of blood flow velocity. The directional baseband Doppler shift signals were obtained using a portable analog circuit system. After hardware processing, the Doppler signals were fed directly to a smartphone for Doppler spectrogram analysis and display in real time. To the best of our knowledge, this is the first report of the use of this system for medical ultrasound Doppler signal processing. A Couette flow phantom, consisting of two parallel disks with a 2-mm gap, was used to evaluate and calibrate the device. Doppler spectrograms of porcine blood flow were measured using this stand-alone portable device under the pulsatile condition. Subsequently, in vivo portable system verification was performed by measuring the arterial blood flow of a rat and comparing the results with the measurement from a commercial ultrasound duplex scanner. All of the results demonstrated the potential for using a smartphone as a novel embedded system for portable medical ultrasound applications. © 2012 IEEE

  7. Automatic segmentation and measurements of gestational sac using static B-mode ultrasound images

    Science.gov (United States)

    Ibrahim, Dheyaa Ahmed; Al-Assam, Hisham; Du, Hongbo; Farren, Jessica; Al-karawi, Dhurgham; Bourne, Tom; Jassim, Sabah

    2016-05-01

    Ultrasound imagery has been widely used for medical diagnoses. Ultrasound scanning is safe and non-invasive, and hence used throughout pregnancy for monitoring growth. In the first trimester, an important measurement is that of the Gestation Sac (GS). The task of measuring the GS size from an ultrasound image is done manually by a Gynecologist. This paper presents a new approach to automatically segment a GS from a static B-mode image by exploiting its geometric features for early identification of miscarriage cases. To accurately locate the GS in the image, the proposed solution uses wavelet transform to suppress the speckle noise by eliminating the high-frequency sub-bands and prepare an enhanced image. This is followed by a segmentation step that isolates the GS through the several stages. First, the mean value is used as a threshold to binarise the image, followed by filtering unwanted objects based on their circularity, size and mean of greyscale. The mean value of each object is then used to further select candidate objects. A Region Growing technique is applied as a post-processing to finally identify the GS. We evaluated the effectiveness of the proposed solution by firstly comparing the automatic size measurements of the segmented GS against the manual measurements, and then integrating the proposed segmentation solution into a classification framework for identifying miscarriage cases and pregnancy of unknown viability (PUV). Both test results demonstrate that the proposed method is effective in segmentation the GS and classifying the outcomes with high level accuracy (sensitivity (miscarriage) of 100% and specificity (PUV) of 99.87%).

  8. Attenuation measuring ultrasound shearwave elastography and in vivo application in post-transplant liver patients

    Science.gov (United States)

    Nenadic, Ivan Z.; Qiang, Bo; Urban, Matthew W.; Zhao, Heng; Sanchez, William; Greenleaf, James F.; Chen, Shigao

    2017-01-01

    Ultrasound and magnetic resonance elastography techniques are used to assess mechanical properties of soft tissues. Tissue stiffness is related to various pathologies such as fibrosis, loss of compliance, and cancer. One way to perform elastography is measuring shear wave velocity of propagating waves in tissue induced by intrinsic motion or an external source of vibration, and relating the shear wave velocity to tissue elasticity. All tissues are inherently viscoelastic and ignoring viscosity biases the velocity-based estimates of elasticity and ignores a potentially important parameter of tissue health. We present attenuation measuring ultrasound shearwave elastography (AMUSE), a technique that independently measures both shear wave velocity and attenuation in tissue and therefore allows characterization of viscoelasticity without using a rheological model. The theoretical basis for AMUSE is first derived and validated in finite element simulations. AMUSE is validated against the traditional methods for assessing shear wave velocity (phase gradient) and attenuation (amplitude decay) in tissue mimicking phantoms and excised tissue. The results agreed within one standard deviation. AMUSE was used to measure shear wave velocity and attenuation in 15 transplanted livers in patients with potential acute rejection, and the results were compared with the biopsy findings in a preliminary study. The comparison showed excellent agreement and suggests that AMUSE can be used to separate transplanted livers with acute rejection from livers with no rejection.

  9. Automated kidney morphology measurements from ultrasound images using texture and edge analysis

    Science.gov (United States)

    Ravishankar, Hariharan; Annangi, Pavan; Washburn, Michael; Lanning, Justin

    2016-04-01

    In a typical ultrasound scan, a sonographer measures Kidney morphology to assess renal abnormalities. Kidney morphology can also help to discriminate between chronic and acute kidney failure. The caliper placements and volume measurements are often time consuming and an automated solution will help to improve accuracy, repeatability and throughput. In this work, we developed an automated Kidney morphology measurement solution from long axis Ultrasound scans. Automated kidney segmentation is challenging due to wide variability in kidney shape, size, weak contrast of the kidney boundaries and presence of strong edges like diaphragm, fat layers. To address the challenges and be able to accurately localize and detect kidney regions, we present a two-step algorithm that makes use of edge and texture information in combination with anatomical cues. First, we use an edge analysis technique to localize kidney region by matching the edge map with predefined templates. To accurately estimate the kidney morphology, we use textural information in a machine learning algorithm framework using Haar features and Gradient boosting classifier. We have tested the algorithm on 45 unseen cases and the performance against ground truth is measured by computing Dice overlap, % error in major and minor axis of kidney. The algorithm shows successful performance on 80% cases.

  10. Fetal growth and air pollution - A study on ultrasound and birth measures.

    Science.gov (United States)

    Malmqvist, Ebba; Liew, Zeyan; Källén, Karin; Rignell-Hydbom, Anna; Rittner, Ralf; Rylander, Lars; Ritz, Beate

    2017-01-01

    Air pollution has been suggested to affect fetal growth, but more data is needed to assess the timing of exposure effects by using ultrasound measures. It is also important to study effects in low exposure areas to assess eventual thresholds of effects. The MAPSS (Maternal Air Pollution in Southern Sweden) cohort consists of linked registry data for around 48,000 pregnancies from an ultrasound database, birth registry and exposure data based on residential addresses. Measures of air pollution exposure were obtained through dispersion modelling with input data from an emissions database (NOx) with high resolution (100-500m grids). Air pollution effects were assessed with linear regressions for the following endpoints; biparietal diameter, femur length, abdominal diameter and estimated fetal weight measured in late pregnancy and birth weight and head circumference measured at birth. We estimated negative effects for NOx; in the adjusted analyses the decrease of abdominal diameter and femur length were -0.10 (-0.17, -0.03) and -0.13 (-0.17, -0.01)mm, respectively, per 10µg/m(3) increment of NOx. We also estimated an effect of NOx-exposures on birth weight by reducing birth weight by 9g per 10µg/m(3) increment of NOx. We estimated small but statistically significant effects of air pollution on late fetal and birth size and reduced fetal growth late in pregnancy in a geographic area with levels below current WHO air quality guidelines.

  11. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the prostate is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any ... size with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate ...

  12. Prostate Ultrasound

    Medline Plus

    Full Text Available ... prostate is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any ... with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate ...

  13. Validation of ultrasound as a noninvasive tool to measure subcutaneous fat depth in leatherback sea turtles (Dermochelys coriacea)

    Science.gov (United States)

    Harris, Heather S.; Benson, Scott R.; James, Michael C.; Martin, Kelly J.; Stacy, Brian A.; Daoust, Pierre-Yves; Rist, Paul M.; Work, Thierry M.; Balazs, George H.; Seminoff, Jeffrey A.

    2016-01-01

    Leatherback turtles (Dermochelys coriacea) undergo substantial cyclical changes in body condition between foraging and nesting. Ultrasonography has been used to measure subcutaneous fat as an indicator of body condition in many species but has not been applied in sea turtles. To validate this technique in leatherback turtles, ultrasound images were obtained from 36 live-captured and dead-stranded immature and adult turtles from foraging and nesting areas in the Pacific and Atlantic oceans. Ultrasound measurements were compared with direct measurements from surgical biopsy or necropsy. Tissue architecture was confirmed histologically in a subset of turtles. The dorsal shoulder region provided the best site for differentiation of tissues. Maximum fat depth values with the front flipper in a neutral (45–90°) position demonstrated good correlation with direct measurements. Ultrasound-derived fat measurements may be used in the future for quantitative assessment of body condition as an index of health in this critically endangered species.

  14. VALIDATION OF ULTRASOUND AS A NONINVASIVE TOOL TO MEASURE SUBCUTANEOUS FAT DEPTH IN LEATHERBACK SEA TURTLES (DERMOCHELYS CORIACEA).

    Science.gov (United States)

    Harris, Heather S; Benson, Scott R; James, Michael C; Martin, Kelly J; Stacy, Brian A; Daoust, Pierre-Yves; Rist, Paul M; Work, Thierry M; Balazs, George H; Seminoff, Jeffrey A

    2016-03-01

    Leatherback turtles (Dermochelys coriacea) undergo substantial cyclical changes in body condition between foraging and nesting. Ultrasonography has been used to measure subcutaneous fat as an indicator of body condition in many species but has not been applied in sea turtles. To validate this technique in leatherback turtles, ultrasound images were obtained from 36 live-captured and dead-stranded immature and adult turtles from foraging and nesting areas in the Pacific and Atlantic oceans. Ultrasound measurements were compared with direct measurements from surgical biopsy or necropsy. Tissue architecture was confirmed histologically in a subset of turtles. The dorsal shoulder region provided the best site for differentiation of tissues. Maximum fat depth values with the front flipper in a neutral (45-90°) position demonstrated good correlation with direct measurements. Ultrasound-derived fat measurements may be used in the future for quantitative assessment of body condition as an index of health in this critically endangered species.

  15. Bone QUS measurement performed under loading condition, a more accuracy ultrasound method for osteoporosis diagnosis.

    Science.gov (United States)

    Liu, Chengrui; Niu, Haijun; Fan, Yubo; Li, Deyu

    2012-10-01

    Osteoporosis is a worldwide health problem with enormous social and economic impact. Quantitative ultrasound (QUS) method provides comprehensive information on bone mass, microstructure and mechanical properties of the bone. And the cheap, safe and portable ultrasound equipment is more suitable for public health monitoring. QUS measurement was normally performed on bone specimens without mechanical loading. But human bones are subjected to loading during routine daily activities, and physical loading leads to the changes of bone microstructure and mechanical properties. We hypothesized that bone QUS parameters measured under loading condition differ from those measured without loading because the microstructure of bone was changed when loading subjected to bone. Furthermore, when loading was subjected on bone, the loading-lead microstructure change of osteoporosis bone may larger than that of health bone. By considering the high relationship between bone microstructure and QUS parameters, the QUS parameters of osteoporosis bone may changed larger than that of health bone. So osteoporosis may be detected more effectively by the combination of QUS method and mechanical loading.

  16. Properties of Ultrasound Probes

    OpenAIRE

    Rusina, M.

    2015-01-01

    This work deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. In this work there are described the possibility of measuring the spatial resolution, sensitivity of the probe and measuring the length of the dead zone. Ultrasound phantom ATS Multi Purpose Phantom Type 539 was used for measurements.

  17. Theoretical model of intravascular paramagnetic tracers effect on tissue relaxation

    DEFF Research Database (Denmark)

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

    2006-01-01

    that the relaxivity of intravascular contrast agents depends significantly on the host tissue. This agrees with experimental data by Johnson et al. (Magn Reson Med 2000;44:909). In particular, the present results suggest a several-fold increase in the relaxivity of Gd-based contrast agents in brain tissue compared...... with bulk blood. The enhancement of relaxation in tissue is due to the contrast in magnetic susceptibility between blood vessels and parenchyma induced by the presence of paramagnetic tracer. Beyond the perfusion measurements, the results can be applied to quantitation of functional MRI and to vessel size......The concentration of MRI tracers cannot be measured directly by MRI and is commonly evaluated indirectly using their relaxation effect. This study develops a comprehensive theoretical model to describe the transverse relaxation in perfused tissue caused by intravascular tracers. The model takes...

  18. Comparison of sound speed measurements on two different ultrasound tomography devices

    Science.gov (United States)

    Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Sherman, Mark; Gierach, Gretchen; Malyarenko, Antonina

    2014-03-01

    Ultrasound tomography (UST) employs sound waves to produce three-dimensional images of breast tissue and precisely measures the attenuation of sound speed secondary to breast tissue composition. High breast density is a strong breast cancer risk factor and sound speed is directly proportional to breast density. UST provides a quantitative measure of breast density based on three-dimensional imaging without compression, thereby overcoming the shortcomings of many other imaging modalities. The quantitative nature of the UST breast density measures are tied to an external standard, so sound speed measurement in breast tissue should be independent of specific hardware. The work presented here compares breast sound speed measurement obtained with two different UST devices. The Computerized Ultrasound Risk Evaluation (CURE) system located at the Karmanos Cancer Institute in Detroit, Michigan was recently replaced with the SoftVue ultrasound tomographic device. Ongoing clinical trials have used images generated from both sets of hardware, so maintaining consistency in sound speed measurements is important. During an overlap period when both systems were in the same exam room, a total of 12 patients had one or both of their breasts imaged on both systems on the same day. There were 22 sound speed scans analyzed from each system and the average breast sound speeds were compared. Images were either reconstructed using saved raw data (for both CURE and SoftVue) or were created during the image acquisition (saved in DICOM format for SoftVue scans only). The sound speed measurements from each system were strongly and positively correlated with each other. The average difference in sound speed between the two sets of data was on the order of 1-2 m/s and this result was not statistically significant. The only sets of images that showed a statistical difference were the DICOM images created during the SoftVue scan compared to the SoftVue images reconstructed from the raw data

  19. MR guided focused ultrasound: technical acceptance measures for a clinical system

    Energy Technology Data Exchange (ETDEWEB)

    Gorny, K R; Hangiandreou, N J; Hesley, G K; Gostout, B S; McGee, K P; Felmlee, J P [Department of Radiology, Mayo Clinic, Rochester, MN 55905 (United States)

    2006-06-21

    Magnetic resonance (MR) guided focused ultrasound (MRgFUS) is a hybrid technique which offers efficient and safe focused ultrasound (FUS) treatments of uterine fibroids under MR guidance and monitoring. As a therapy device, MRgFUS requires systematic testing over a wide range of operational parameters prior to use in the clinical environment. We present technical acceptance tests and data for the first clinical MRgFUS system, ExAblate (registered) 2000 (InSightec Inc., Haifa, Israel), that has been FDA approved for treating uterine fibroids. These tests characterize MRgFUS by employing MR temperature measurements in tissue mimicking phantoms. The coronal scan plane is empirically demonstrated to be most reliable for measuring temperature elevations resulting from high intensity ultrasound (US) pulses ('sonications') and shows high sensitivity to changes in sonication parameters. Temperatures measured in the coronal plane were used as a measure of US energy deposited within the focal spot for a range of sonication parameters used in clinical treatments: spot type, spot length, output power, sonication duration, US frequency, and depth of sonication. In addition, MR images acquired during sonications were used to measure effective diameters and lengths of available sonication spot types and lengths. At a constant 60 W output power, the effective spot type diameters were measured to vary between 4.7 {+-} 0.3 mm and 6.6 {+-} 0.4 mm; treatment temperatures were found to decrease with increasing spot diameter. Prescribing different spot lengths was found to have no effect on the measured length or on measured temperatures. Tests of MRgFUS positioning accuracy determined errors in the direction parallel to the propagation of the US beam to be significantly greater than those in the perpendicular direction; most sonication spots were erroneously positioned towards the FUS transducer. The tests reported here have been demonstrated to be sufficiently sensitive to

  20. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... specific content. Related Articles and Media Sonohysterography Ultrasound - Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and ...

  1. Focused intravascular ultrasonic probe using dimpled transducer elements.

    Science.gov (United States)

    Chen, Y; Qiu, W B; Lam, K H; Liu, B Q; Jiang, X P; Zheng, H R; Luo, H S; Chan, H L W; Dai, J Y

    2015-02-01

    High-frequency focused intravascular ultrasonic probes were fabricated in this study using dimple technique based on PMN-PT single crystal and lead-free KNN-KBT-Mn ceramic. The center frequency, bandwidth, and insertion loss of the PMN-PT transducer were 34 MHz, 75%, and 22.9 dB, respectively. For the lead-free probe, the center frequency, bandwidth, and insertion loss were found to be 40 MHz, 72%, and 28.8 dB, respectively. The ultrasonic images of wire phantom and vessels with good resolution were obtained to evaluate the transducer performance. The -6 dB axial and lateral resolutions of the PMN-PT probe were determined to be 58 μm and 131 μm, respectively. For the lead-free probe, the axial and lateral resolutions were found to be 44 μm and 125 μm, respectively. These results suggest that the mechanical dimpling technique has good potential in preparing focused transducers for intravascular ultrasound applications.

  2. High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

    Science.gov (United States)

    Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2016-02-01

    Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

  3. Iatrogenic intravascular pneumocephalus secondary to intravenous catheterization

    Energy Technology Data Exchange (ETDEWEB)

    Yildiz, Altan; Oezer, Caner; Egilmez, Hulusi; Duce, Meltem Nass; Apaydin, Demir F.; Yalcinoglu, Orhan [Department of Radiology, Faculty of Medicine, Mersin University (Turkey)

    2002-03-01

    The presence of pneumocephalus without a history of intracranial or intrathecal procedures is a significant radiographic finding. Although pneumocephalus means a violation of the dural barrier or the presence of infection, intravascular pneumocephalus is different from intraparenchymal pneumocephalus and its benign nature must be known in the presence of intravenous catheterization. Herein, we present a case of iatrogenic intravascular pneumocephalus with CT findings. To our knowledge, there are only a few reported cases of iatrogenic intravascular pneumocephalus in the literature. Careful intravenous catheterization and diagnosis of the condition on imaging helps to prevent unnecessary treatment procedures. (orig.)

  4. Estimation of multipath transmission parameters for quantitative ultrasound measurements of bone.

    Science.gov (United States)

    Dencks, Stefanie; Schmitz, Georg

    2013-09-01

    When applying quantitative ultrasound (QUS) measurements to bone for predicting osteoporotic fracture risk, the multipath transmission of sound waves frequently occurs. In the last 10 years, the interest in separating multipath QUS signals for their analysis awoke, and led to the introduction of several approaches. Here, we compare the performances of the two fastest algorithms proposed for QUS measurements of bone: the modified least-squares Prony method (MLSP), and the space alternating generalized expectation maximization algorithm (SAGE) applied in the frequency domain. In both approaches, the parameters of the transfer functions of the sound propagation paths are estimated. To provide an objective measure, we also analytically derive the Cramér-Rao lower bound of variances for any estimator and arbitrary transmit signals. In comparison with results of Monte Carlo simulations, this measure is used to evaluate both approaches regarding their accuracy and precision. Additionally, with simulations using typical QUS measurement settings, we illustrate the limitations of separating two superimposed waves for varying parameters with focus on their temporal separation. It is shown that for good SNRs around 100 dB, MLSP yields better results when two waves are very close. Additionally, the parameters of the smaller wave are more reliably estimated. If the SNR decreases, the parameter estimation with MLSP becomes biased and inefficient. Then, the robustness to noise of the SAGE clearly prevails. Because a clear influence of the interrelation between the wavelength of the ultrasound signals and their temporal separation is observable on the results, these findings can be transferred to QUS measurements at other sites. The choice of the suitable algorithm thus depends on the measurement conditions.

  5. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  6. Obstetrical disseminated intravascular coagulation score.

    Science.gov (United States)

    Kobayashi, Takao

    2014-06-01

    Obstetrical disseminated intravascular coagulation (DIC) is usually a very acute, serious complication of pregnancy. The obstetrical DIC score helps with making a prompt diagnosis and starting treatment early. This DIC score, in which higher scores are given for clinical parameters rather than for laboratory parameters, has three components: (i) the underlying diseases; (ii) the clinical symptoms; and (iii) the laboratory findings (coagulation tests). It is justifiably appropriate to initiate therapy for DIC when the obstetrical DIC score reaches 8 points or more before obtaining the results of coagulation tests. Improvement of blood coagulation tests and clinical symptoms are essential to the efficacy evaluation for treatment after a diagnosis of obstetrical DIC. Therefore, the efficacy evaluation criteria for obstetrical DIC are also defined to enable follow-up of the clinical efficacy of DIC therapy.

  7. Experience with intravascular lead extraction

    Institute of Scientific and Technical Information of China (English)

    MA Jian; TANG Kai; WANG Fang-zheng; ZHANG Shu; HUANG Cong-xin

    2005-01-01

    @@ With the increase of clinical use of cardiac pacemaker, a certain kinds of severe leads-related complications (especially infection) have presented in a few patients who underwent pacemaker implantation. The best way to manage this problem is to remove the transvenous leads.1,2 The technique for percutaneous removal of transvenous leads have undergone considerable development in western countries over the past 2 decades. However, there was scarce data on the application of this technique in China. This article reports the results of transvenous extraction of 171 permanent pacemaker leads with the standard lead extraction devices and intravascular countertraction technique during the period from January 1996 to May 2005 in the Center of Arrhythmia Diagnosis and Treatment, Fu Wai Hospital, Beijing, China.

  8. Intravascular Stenting in Microvascular Anastomoses

    DEFF Research Database (Denmark)

    Assersen, Kristine; Sørensen, Jens

    2015-01-01

    Background The effect of intravascular stenting (IVaS) on microvascular anastomoses has given adverse results. For experienced microsurgeons the benefit of IVaS is doubtful. We have investigated the potential benefit of the IVaS technique for two groups of inexperienced microsurgeons with different...... surgical levels of experience (medical students and young residents). Experienced microsurgeons acted as a control group. Materials and Methods In an experimental crossover study, 139 microsurgical anastomoses were performed on the femoral artery in 70 rats by 10 surgeons. On one side of the rat, the IVaS...... spent on the anastomosis. Results No significant difference in patency rates was seen between the stenting and conventional technique in all three groups. The experienced microsurgeons had 100% patency rate with both techniques. The medical students had 20/28 in the IVaS and 19/28 conventional group...

  9. Imminent Cardiac Risk Assessment via Optical Intravascular Biochemical Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, D.; Wetzel, L; Wetzel, M; Lodder, R

    2009-01-01

    still the first line of defense. However, with the fidelity of 64-slice CT imaging, this technique has recently become an option when the patient presents with symptoms of reduced arterial flow. Single photon emission computerized tomography (SPECT) treadmill exercise testing is a standard non-invasive test for decreased perfusion of heart muscle, but is time consuming and not suited for emergent evaluation. Once the invasive clinical option of catherization is chosen, this provides the opportunity for intravascular ultrasound (IVUS) imaging. As the probe is pulled through the artery, the diameter at different parts is measurable, and monochrome contrast in the constricted area reveals the presence of tissue with a different ultrasonic response. Also, via an optical catheter with a fiber-optic conductor, the possibly of spectroscopic analysis of arterial walls is now a reality. In this case, the optical transducer is coupled to a near-infrared spectrometer. Revealing the arterial chemical health means that plaque vulnerability and imminent risk could be assessed by the physician. The classical emergency use of catherization involves a contrast agent and dynamic X-ray imaging to locate the constriction, determine its severity, and possibly perform angioplasty, and stent placement.

  10. Intravascular ultrasound in guiding endovascular aortic aneurysm repair-a case report of interventional therapy without contrast media%血管内超声介导下主动脉夹层腔内修复术无造影剂介入治疗1例报道

    Institute of Scientific and Technical Information of China (English)

    罗建方; 黄文晖; 谢年谨; 胡孜阳; 刘媛; 杨峻青; 范瑞新; 陈纪言

    2011-01-01

    Objectives To investigate the feasibility and clinical value of intravascular ultrasound (IVUS) in guiding endovascular aortic aneurysm repair (EVAR). Methods With EVAR procedure for a patient suffered from Standford type B aortic dissection and renal insufficiency, we utilized IVUV to guide the lumen tracking, rupture site localization, stent delivery and intra-procedure examination of anatomic result. We attempted to avoid any dose of iodic contrast. Results Zero milliliter iodic contrast was consumed in the procedure and this procedure lasted for 12S minutes. The operation was smoothly performed and anatomic result was satisfactory. No complication occurred after operation. The patient's concentration of serum creatinine did not increase within a week monitor. Conclusions IVUS guided EVAR is feasible in this patients. Iodic contrast may be avoided with the utilization of this technique and sequentially renal function be protected.%目的 探讨血管内超声代替基于造影剂的血管显影指引主动脉腔内修复术的可行性和价值.方法 我们对1例Standford B型主动脉夹层合并肾功能不全患者行主动脉腔内修复术,术中使用血管内超声指引寻腔、定位、支架释放和进行解剖学检查,全程避免使用造影剂.结果 手术使用造影剂0 mL,手术时间125 min,寻腔、定位及支架释放过程顺利.支架到位准确,扩张及贴壁良好.术后无内漏或新发夹层,无其他并发症.术后1周患者血清肌酐浓度无增高.结论在本例患者中,血管内超声代替基于造影剂的血管显影指引主动脉腔内修复术可行,该技术可能避免肾功能不全患者肾功能恶化.

  11. Ultrasound in trauma.

    Science.gov (United States)

    Rippey, James C R; Royse, Alistair G

    2009-09-01

    Point-of-care ultrasound is well suited for use in the emergency setting for assessment of the trauma patient. Currently, portable ultrasound machines with high-resolution imaging capability allow trauma patients to be imaged in the pre-hospital setting, emergency departments and operating theatres. In major trauma, ultrasound is used to diagnose life-threatening conditions and to prioritise and guide appropriate interventions. Assessment of the basic haemodynamic state is a very important part of ultrasound use in trauma, but is discussed in more detail elsewhere. Focussed assessment with sonography for Trauma (FAST) rapidly assesses for haemoperitoneum and haemopericardium, and the Extended FAST examination (EFAST) explores for haemothorax, pneumothorax and intravascular filling status. In regional trauma, ultrasound can be used to detect fractures, many vascular injuries, musculoskeletal injuries, testicular injuries and can assess foetal viability in pregnant trauma patients. Ultrasound can also be used at the bedside to guide procedures in trauma, including nerve blocks and vascular access. Importantly, these examinations are being performed by the treating physician in real time, allowing for immediate changes to management of the patient. Controversy remains in determining the best training to ensure competence in this user-dependent imaging modality.

  12. Measurement of blood flow volume and its characteristic in the shunt after TIPS with intravascular Doppler guidewire%多普勒导丝评价TIPS术门腔分流道血流特点

    Institute of Scientific and Technical Information of China (English)

    徐晤; 祖茂衡; 王志荣; 李国均

    2012-01-01

    Objective Via the measurement of blood flow volume after TIPS (transjugular intrahepatic portosystemic shunt) with intravascular Doppler guidewire, a novel, reliable method to investigate the hemodynamical parameters of TIPS was tested. Methods With Doppler guidewire. blood flow velocity in the TIPS of 10 patients with portal hypertension were measured, and with the aid of DSA, blood flow volume was obtained. 10 normal hepatic veins were taken as contral. Results After TIPS,some parameters in the TIPS were gained: Average Peak Velocity (APV) was (18. 51± 7. 32) cm/s, Maximum Peak Velocity (MPV) was (25. 93±9. 54) cm/s, blood flow volumes were (557. 95 + 94. 57) ml/ min; and blood flow spectrum was acquired. The wave was nomo-phase in pattern and dischanged with the heart cycle. At the same time, the parameters in hepatic veins were as follows; APV was (15. 73±4. 52) cm/s;MPV was (26. 01±8. 33) cm/s;blood flow volume was (654. 64± 108. 56) ml/min. The wave was three-phase in pattern and changed with the heart cycle. Conclusion Accurately and conveniently, blood flow velocity in the TIPS was measured by intravascular Doppler guidewire. The present work on the TIPS in patients illustrated that the novel method is practicable and reliable for measuring the blood flow,%目的 应用血管内多普勒导丝测定TIPS术后门腔分流量及血流特点,提出一种新的、更可靠的检测静脉血流动力学指标的方法.方法 10例门静脉高压患者TIPS术后即刻,使用血管内多普勒导丝测定分流通道内血流速度,结合DSA技术,测出血流量;并予10例正常肝静脉血流作为对照.结果 测得TIPS术后分流通道内的平均峰值流速(APV)为(18.51±7.32)cm/s,最大峰值流速(MPV)为(25.93±9,54)cm/s,分流道的直径为(0.80±0.26)cm,门腔分流量为(557.96±94.57)ml/min,并且获得血流频谱特点为波形呈单相,不随心动周期而变化.而肝静脉APV为(15.73±4.52)cm/s;MPV为(26.01±8.33)cm

  13. 3-D Ultrasound Imaging Performance of a Row-Column Addressed 2-D Array Transducer: A Measurement Study

    DEFF Research Database (Denmark)

    Rasmussen, Morten Fischer; Jensen, Jørgen Arendt

    2013-01-01

    A real-time 3-D ultrasound measurement using only 32 elements and 32 emissions is presented. The imaging quality is compared to a conventionally fully addressed array using 1024 elements and 256 emissions. The main-lobe of the measured line spread function is almost identical, but the side-lobe l...... ultrasound probe made by Vermon S.A....... is 510% larger than when row-column addressing the array. The cyst radius needed to achieve -20 dB intensity in the cyst is 396% larger for the fully addressed array compared to the row-column addressed array. The measurements were made using the experimental ultrasound scanner SARUS and a 32x32 element...

  14. Influence of lung injury on cardiac output measurement using transpulmonary ultrasound dilution: a validation study in neonatal lambs

    NARCIS (Netherlands)

    Vrancken, S.L.A.G.; Boode, W.P. de; Hopman, J.C.W.; Looijen-Salamon, M.G.; Liem, K.D.; Heijst, A.F. van

    2012-01-01

    BACKGROUND: /st> Transpulmonary ultrasound dilution (TPUD) is a promising method for cardiac output (CO) measurement in severely ill neonates. The incidence of lung injury in this population is high, which might influence CO measurement using TPUD because of altered lung perfusion. We evaluated t

  15. Characterization of fetal growth by repeated ultrasound measurements in the wild guinea pig (Cavia aperea).

    Science.gov (United States)

    Schumann, K; Guenther, A; Göritz, F; Jewgenow, K

    2014-08-01

    Fetal growth during pregnancy has previously been studied in the domesticated guinea pig (Cavia aperea f. porcellus) after dissecting pregnant females, but there are no studies describing the fetal growth in their wild progenitor, the wild guinea pig (C aperea). In this study, 50 pregnancies of wild guinea pig sows were investigated using modern ultrasound technique. The two most common fetal growth parameters (biparietal diameter [BPD] and crown-rump-length [CRL]) and uterine position were measured. Data revealed similar fetal growth patterns in the wild guinea pig and domesticated guinea pig in the investigated gestation period, although they differ in reproductive milestones such as gestation length (average duration of pregnancy 68 days), average birth weight, and litter mass. In this study, pregnancy lasted on average 60.2 days with a variance of less than a day (0.96 days). The measured fetal growth parameters are strongly correlated with each (R = 0.91; P guinea pig.

  16. Photoacoustic clutter reduction by inversion of a linear scatter model using plane wave ultrasound measurements.

    Science.gov (United States)

    Schwab, Hans-Martin; Beckmann, Martin F; Schmitz, Georg

    2016-04-01

    Photoacoustic imaging aims to visualize light absorption properties of biological tissue by receiving a sound wave that is generated inside the observed object as a result of the photoacoustic effect. In clinical applications, the strong light absorption in human skin is a major problem. When high amplitude photoacoustic waves that originate from skin absorption propagate into the tissue, they are reflected back by acoustical scatterers and the reflections contribute to the received signal. The artifacts associated with these reflected waves are referred to as clutter or skin echo and limit the applicability of photoacoustic imaging for medical applications severely. This study seeks to exploit the acoustic tissue information gained by plane wave ultrasound measurements with a linear array in order to correct for reflections in the photoacoustic image. By deriving a theory for clutter waves in k-space and a matching inversion approach, photoacoustic measurements compensated for clutter are shown to be recovered.

  17. MODELLING OF EXTRINSIC FIBER OPTIC SAGNAC ULTRASOUND INTERFEROMETER USED FOR DISPLACEMENT MEASUREMENTS

    Directory of Open Access Journals (Sweden)

    S. BENHAMIDA

    2012-06-01

    Full Text Available Ultrasonic waves are used extensively in nondestructive testing both for characterization of material properties, in this paper, we describe a fiber optic sensor suitable for detection of ultrasonic waves. This sensor is based on an extrinsic fiber optic sagnac interferometer. The proposed sensor model can act as a conventional in-phase detector or as a narrowband detector. In this study we use methods interference of ultrasonic waves between the source of ultrasonic waves and the object under investigation is exploited. The main advantages of the proposed sensor are the ability to detect ultrasonic waves on the surface; this sensor possesses higher sensitivity and accuracy than the pulse method. The cavity resonator was very successfully used for measurement of small ultrasound velocity changes. The ultrasonic interferometric technique based on phase-locked loop is the most suitable for measurements of small displacements. This method ensures the highest sensitivity and accuracy.

  18. What is the value of ultrasound soft tissue measurements in the prediction of abnormal fetal growth?

    LENUS (Irish Health Repository)

    Farah, N

    2012-02-01

    Abnormal fetal growth increases the complications of pregnancy not only for the baby but also for the mother. Growth abnormalities also have lifelong consequences. These babies are at increased risk of insulin resistance, diabetes and hypertension later in life. It is important to identify these babies antenatally to optimise their clinical care. Although used extensively antenatally to monitor fetal growth, ultrasound has its limitations. Despite the use of more than 50 different formulae to estimate fetal weight, their performance has been poor at the extremes of fetal weight. Over the past 20 years there has been emerging interest in studying fetal soft tissue measurements to improve detection of growth abnormalities. This review paper outlines the value of soft tissue measurements in identifying fetal growth abnormalities, in estimating fetal weight and in managing diabetes mellitus in pregnancy.

  19. Ultrasound measurements in the spinel compound GeCo{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Sasame, H [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Yoshimoto, H [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Takahashi, Y [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Watanabe, T [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Takase, K [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Takano, Y [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Hara, S [AIST, Tsukuba, 305-8568 Ibaraki (Japan); Ikeda, Si [AIST, Tsukuba, 305-8568 Ibaraki (Japan)

    2007-12-15

    Elastic properties of the spinel compound GeCo{sub 2}O{sub 4} were investigated by the ultrasound velocity measurements in the single crystal. Absence of the elastic softening in (C{sub 11}- C{sub 12})/2 in the paramagnetic state suggests the Jahn-Teller inactive character of Co{sup 2+}, despite the presence of the orbital degree of freedom. The pronounced C{sub 44} anomaly in the paramagnetic state near T{sub N} alternatively suggests that the ultrasound dominantly couple to the exchange interactions among Co{sup 2+} ions by the exchange striction effect. The present results conclude that Co{sup 2+} adopts the high spin state in this substance. In the antiferromagnetic phase, new elastic anomalies were observed only in (C{sub 11}- C{sub 12})/2 implying the occurrence of the magnetic transitions triggered by the exchange interactions within the Co{sup 2+} bonds along [110] directions.

  20. Development of a thermal test object for the measurement of ultrasound intracavity transducer self-heating.

    Science.gov (United States)

    Killingback, Alban L T; Newey, Valentine R; El-Brawany, Mohamed A; Nassiri, Dariush K

    2008-12-01

    The elevated surface temperature of diagnostic ultrasound transducers imposes an important limitation to their safe use in clinical situations. Moreover, particular care should be taken if transvaginal transducers are to be used during routine scans in the first few weeks of pregnancy as the transducer surface can be very close to embryonic/fetal tissues. Published results have shown that the heating of tissue due to transducer self-heating can equal and often exceed the acoustic heating contribution. In this article, we report the development of a portable self contained thermal test object (TTO) capable of assessing the self-heating of intracavity diagnostic ultrasound transducers. The thermal conductivity and volumetric heat capacity of the tissue mimicking material (TMM) used in the TTO were measured, yielding values of (0.56 +/- 0.01) W m(-1) K(-1) and (3.5 +/- 0.8) MJ m(-3) K(-1). The speed of sound of the TMM was measured as 1540 m s(-1) and the attenuation over a frequency range of 2 to 10 MHz was found to be (0.50 +/- 0.01) dB cm(-1) MHz(-1). These results are in excellent agreement with the International Electrotechnical Commission (IEC 60601-2-37) requirements and the previously published properties of biological soft tissue. The temperature stability and uniformity, and suitability of the TTO for the measurement of transducer self-heating were tested and found to be satisfactory. The TTO reached a stable temperature of 37 degrees C in 3 h and the spatial variation in temperature was less than +/- 0.2 degrees C. Lastly, transducer self-heating measurements from a transvaginal transducer exceeded the IEC temperature limit of 43 degrees C in less than 5 min and the temperature reached after 30 min was 47.3 degrees C.

  1. Intravascular probe for detection of vulnerable plaque

    Science.gov (United States)

    Patt, Bradley E.; Iwanczyk, Jan S.; MacDonald, Lawrence R.; Yamaguchi, Yuko; Tull, Carolyn R.; Janecek, Martin; Hoffman, Edward J.; Strauss, H. William; Tsugita, Ross; Ghazarossian, Vartan

    2001-12-01

    Coronary angiography is unable to define the status of the atheroma, and only measures the luminal dimensions of the blood vessel, without providing information about plaque content. Up to 70% of heart attacks are caused by minimally obstructive vulnerable plaques, which are too small to be detected adequately by angiography. We have developed an intravascular imaging detector to identify vulnerable coronary artery plaques. The detector works by sensing beta or conversion electron radiotracer emissions from plaque-binding radiotracers. The device overcomes the technical constraints of size, sensitivity and conformance to the intravascular environment. The detector at the distal end of the catheter uses six 7mm long by 0.5mm diameter scintillation fibers coupled to 1.5m long plastic fibers. The fibers are offset from each other longitudinally by 6mm and arranged spirally around a guide wire in the catheter. At the proximal end of the catheter the optical fibers are coupled to an interface box with a snap on connector. The interface box contains a position sensitive photomultiplier tube (PSPMT) to decode the individual fibers. The whole detector assembly fits into an 8-French (2.7 mm in diameter) catheter. The PSPMT image is further decoded with software to give a linear image, the total instantaneous count rate and an audio output whose tone corresponds to the count rate. The device was tested with F-18 and Tl-204 sources. Spectrometric response, spatial resolution, sensitivity and beta to background ratio were measured. System resolution is 6 mm and the sensitivity is >500 cps / micrometers Ci when the source is 1 mm from the detector. The beta to background ratio was 11.2 for F-18 measured on a single fiber. The current device will lead to a system allowing imaging of labeled vulnerable plaque in coronary arteries. This type of signature is expected to enable targeted and cost effective therapies to prevent acute coronary artery diseases such as: unstable angina

  2. Reliability of ultrasound thickness measurement of the abdominal muscles during clinical isometric endurance tests.

    Science.gov (United States)

    ShahAli, Shabnam; Arab, Amir Massoud; Talebian, Saeed; Ebrahimi, Esmaeil; Bahmani, Andia; Karimi, Noureddin; Nabavi, Hoda

    2015-07-01

    The study was designed to evaluate the intra-examiner reliability of ultrasound (US) thickness measurement of abdominal muscles activity when supine lying and during two isometric endurance tests in subjects with and without Low back pain (LBP). A total of 19 women (9 with LBP, 10 without LBP) participated in the study. Within-day reliability of the US thickness measurements at supine lying and the two isometric endurance tests were assessed in all subjects. The intra-class correlation coefficient (ICC) was used to assess the relative reliability of thickness measurement. The standard error of measurement (SEM), minimal detectable change (MDC) and the coefficient of variation (CV) were used to evaluate the absolute reliability. Results indicated high ICC scores (0.73-0.99) and also small SEM and MDC scores for within-day reliability assessment. The Bland-Altman plots of agreement in US measurement of the abdominal muscles during the two isometric endurance tests demonstrated that 95% of the observations fall between the limits of agreement for test and retest measurements. Together the results indicate high intra-tester reliability for the US measurement of the thickness of abdominal muscles in all the positions tested. According to the study's findings, US imaging can be used as a reliable method for assessment of abdominal muscles activity in supine lying and the two isometric endurance tests employed, in participants with and without LBP.

  3. Obstetrical Ultrasound

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Obstetric Ultrasound Obstetric ultrasound uses sound waves to produce pictures ... limitations of Obstetrical Ultrasound Imaging? What is Obstetrical Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  4. Prostate Ultrasound

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves ... the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and ...

  5. Musculoskeletal Ultrasound

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Musculoskeletal Ultrasound imaging uses sound waves to produce ... Ultrasound Imaging of the Musculoskeletal System? What is Ultrasound Imaging of the Musculoskeletal System? Ultrasound is safe ...

  6. Ultrasound - Scrotum

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Scrotum Ultrasound imaging of the scrotum uses sound ... of Ultrasound Imaging of the Scrotum? What is Ultrasound Imaging of the Scrotum? Ultrasound imaging of the ...

  7. Ultrasound -- Vascular

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate ... the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces pictures ...

  8. Hip Ultrasound

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Hip Ultrasound Hip ultrasound uses sound waves to produce pictures ... of Ultrasound Imaging of the Hip? What is Ultrasound Imaging of the Hip? Ultrasound images of the ...

  9. Ultrasound -- Vascular

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate the ... are the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces ...

  10. Feasibility of coded vibration in a vibro-ultrasound system for tissue elasticity measurement.

    Science.gov (United States)

    Zhao, Jinxin; Wang, Yuanyuan; Yu, Jinhua; Li, Tianjie; Zheng, Yong-Ping

    2016-07-01

    The ability of various methods for elasticity measurement and imaging is hampered by the vibration amplitude on biological tissues. Based on the inference that coded excitation will improve the performance of the cross-correlation function of the tissue displacement waves, the idea of exerting encoded external vibration on tested samples for measuring its elasticity is proposed. It was implemented by integrating a programmable vibration generation function into a customized vibro-ultrasound system to generate Barker coded vibration for elasticity measurement. Experiments were conducted on silicone phantoms and porcine muscles. The results showed that coded excitation of the vibration enhanced the accuracy and robustness of the elasticity measurement especially in low signal-to-noise ratio scenarios. In the phantom study, the measured shear modulus values with coded vibration had an R(2 )= 0.993 linear correlation to that of referenced indentation, while for single-cycle pulse the R(2) decreased to 0.987. In porcine muscle study, the coded vibration also obtained a shear modulus value which is more accurate than the single-cycle pulse by 0.16 kPa and 0.33 kPa at two different depths. These results demonstrated the feasibility and potentiality of the coded vibration for enhancing the quality of elasticity measurement and imaging.

  11. Ultrasound measurement of the corpus callosum and neural development of premature infants.

    Science.gov (United States)

    Liu, Fang; Cao, Shikao; Liu, Jiaoran; Du, Zhifang; Guo, Zhimei; Ren, Changjun

    2013-09-15

    Length and thickness of 152 corpus callosa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus callosum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus callosum length as well as thickness of the genu and splenium increased with tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus callosum velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus callosum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose gestational age was 34 weeks or less. Corpus callosum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus callosum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus callosum growth in premature infants is associated with neurobehavioral development during the early extrauterine stage.

  12. Ultrasound measures of supraspinatus tendon thickness and acromiohumeral distance in rotator cuff tendinopathy are reliable.

    Science.gov (United States)

    McCreesh, Karen M; Anjum, Shakeel; Crotty, James M; Lewis, Jeremy S

    2016-01-01

    Rotator cuff (RC) tendinopathy has been widely ascribed to impingement of the supraspinatus tendon (SsT) in the subacromial space, measured as the acromiohumeral distance (AHD). Ultrasound (US) is suitable for measuring AHD and SsT thickness, but few reliability studies have been carried out in symptomatic populations, and interrater reliability is unconfirmed. This study aimed to examine the intrarater and interrater reliability of US measurements of AHD and SsT thickness in asymptomatic control subjects and patients with RC tendinopathy. Seventy participants were recruited and grouped as healthy controls (n = 25) and RC tendinopathy (n = 45). Repeated US measurements of AHD and SsT thickness were obtained by one rater in both groups and by two raters in the RC tendinopathy group. Intrarater and interrater reliability coefficients were excellent for both measurements (intraclass correlation > 0.92), but the intrarater reliability was superior. The minimal detectable change values in the symptomatic group were 0.7 mm for AHD and 0.6 mm for SsT thickness for a single experienced examiner; the values rose to 1.2 mm and 1.3 mm, respectively, for the pair of examiners. The results support the reliability of US for the measurement of AHD and SsT thickness in patients with symptomatic RC tendinopathy and provide minimal detectable change values for use in future research studies. © 2015 Wiley Periodicals, Inc.

  13. Ultrasound-based measurement of liquid-layer thickness: A novel time-domain approach

    Science.gov (United States)

    Praher, Bernhard; Steinbichler, Georg

    2017-01-01

    Measuring the thickness of a thin liquid layer between two solid materials is important when the adequate separation of metallic parts by a lubricant film (e.g., in bearings or mechanical seals) is to be assessed. The challenge in using ultrasound-based systems for such measurements is that the signal from the liquid layer is a superposition of multiple reflections. We have developed an algorithm for reconstructing this superimposed signal in the time domain. By comparing simulated and measured signals, the time-of-flight of the ultrasonic pulse in a layer can be estimated. With the longitudinal sound velocity known, the layer thickness can then be calculated. In laboratory measurements, we validate successfully (maximum relative error 4.9%) our algorithm for layer thicknesses ranging from 30 μm to 200 μm. Furthermore, we tested our method in the high-temperature environment of polymer processing by measuring the clearance between screw and barrel in the plasticisation unit of an injection moulding machine. The results of such measurements can indicate (i) the wear status of the tribo-mechanical screw-barrel system and (ii) unsuitable process conditions.

  14. Medical Ultrasound Imaging.

    Science.gov (United States)

    Hughes, Stephen

    2001-01-01

    Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

  15. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... may also be saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  16. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as ... tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure ...

  17. Dynamic contrast enhanced ultrasound assessment of the vascular effects of novel therapeutics in early stage trials.

    Science.gov (United States)

    Leen, Edward; Averkiou, Michalakis; Arditi, Marcel; Burns, Peter; Bokor, Daniela; Gauthier, Thomas; Kono, Yuko; Lucidarme, Olivier

    2012-07-01

    Imaging is key in the accurate monitoring of response to cancer therapies targeting tumour vascularity to inhibit its growth and dissemination. Dynamic contrast enhanced ultrasound (DCE ultrasound) is a quantitative method with the advantage of being non-invasive, widely available, portable, cost effective, highly sensitive and reproducible using agents that are truly intravascular. Under the auspices of the initiative of the Experimental Cancer Medicine Centre Imaging Network, bringing together experts from the UK, Europe and North America for a 2-day workshop in May 2010, this consensus paper aims to provide guidance on the use of DCE ultrasound in the measurement of tumour vascular support in clinical trials. Key Points • DCE ultrasound can quantify and extract specific blood flow parameters, such as flow velocity, relative vascular volume and relative blood flow rate. • DCE ultrasound can be performed repeatedly and is therefore ideally suited for pharmacokinetic and pharmacodynamic studies evaluating vascular-targeted drugs. • DCE ultrasound provides a reproducible method of assessing the vascular effects of therapy in pre-clinical and early clinical trials, which is easily translatable into routine clinical practice.

  18. Reliability and Validity of Ultrasound Cross Sectional Area Measurements for Long-Duration Spaceflight

    Science.gov (United States)

    Scott, Jessica M.; Martin, David S.; Cunningham, David; Matz, Timothy; Caine, Timothy; Hackney, Kyle J.; Arzeno, Natalia; Ploutz-Snyder, Lori

    2010-01-01

    Limb muscle atrophy and the accompanying decline in function can adversely affect the performance of astronauts during mission-related activities and upon re-ambulation in a gravitational environment. Previous characterization of space flight-induced muscle atrophy has been performed using pre and post flight magnetic resonance imaging (MRI). In addition to being costly and time consuming, MRI is an impractical methodology for assessing in-flight changes in muscle size. Given the mobility of ultrasound (US) equipment, it may be more feasible to evaluate changes in muscle size using this technique. PURPOSE: To examine the reliability and validity of using a customized template to acquire panoramic ultrasound (US) images for determining quadriceps and gastrocnemius anatomical cross sectional area (CSA). METHODS: Vastus lateralis (VL), rectus femoris (RF), medial gastrocnemius (MG), and lateral gastrocnemius (LG) CSA were assessed in 10 healthy individuals (36+/-2 yrs) using US and MRI. Panoramic US images were acquired by 2 sonographers using a customized template placed on the thigh and calf and analyzed by the same 2 sonographers (CX50 Philips). MRI images of the leg were acquired while subjects were supine in a 1.5T scanner (Signa Horizon LX, General Electric) and were analyzed by 3 trained investigators. The average of the 2 US and 3 MRI values were used for validity analysis. RESULTS: High inter-experimenter reliability was found for both the US template and MRI analysis as coefficients of variation across muscles ranged from 2.4 to 4.1% and 2.8 to 3.8%, respectively. Significant correlations were found between US and MRI CSA measures (VL, r = 0.85; RF, r = 0.60; MG, r = 0.86; LG, r = 0.73; p muscles. CONCLUSION: The present results indicate that utilizing a customized US template provides reliable measures of leg muscle CSA, and thus could be used to characterize changes in muscle CSA both in flight and on the ground.

  19. Prediction of outcome after femoropopliteal balloon angioplasty by intravascular ultrasound

    DEFF Research Database (Denmark)

    Vogt, K C; Just, S; Rasmussen, John Bøje Grønvall

    1997-01-01

    arteries remained patent. Two occlusions and two stenoses developed during the first 3 months after the intervention and one occlusion occurred after 1 year. The following IVUS parameters were related to a favourable patency: presence of calcification; dissection or plaque rupture and residual stenosis...

  20. Combinatorial and probabilistic fusion of noisy correlation measurements for untracked freehand 3-D ultrasound.

    Science.gov (United States)

    Laporte, Catherine; Arbel, Tal

    2008-01-01

    In freehand 3-D ultrasound (US), the relative positions of US images are usually measured using a position tracking device despite its cumbersome nature. The probe trajectory can instead be estimated from image data, using registration techniques to recover in-plane motion and speckle decorrelation to recover out-of-plane transformations. The relationship between speckle decorrelation and elevational separation is typically represented by a single curve, estimated from calibration data. Distances read off such a curve are corrupted by bias and uncertainty, and only provide an absolute estimate of elevational displacement. This paper presents a probabilistic model of the relationship between correlation measurements and elevational separation. This representation captures the skewed distribution of distance estimates based on high correlations and the uncertainties attached to each measurement. Multiple redundant correlation measurements can then be integrated within a maximum likelihood estimation framework. This paper also introduces a new method based on the traveling salesman problem for resolving sign ambiguities in data sets resulting from nonmonotonic probe motion and frame intersections. Experiments with real and synthetic US data show that by combining these new methods, out-of-plane US probe motion is recovered with improved accuracy over baseline methods using a deterministic model and fewer measurements.

  1. Coagulación intravascular diseminada = Disseminated intravascular coagulation

    Directory of Open Access Journals (Sweden)

    Arango Barrientos, Marcos

    2010-12-01

    Full Text Available La coagulación intravascular diseminada (CID es una entidad clínica frecuente que se presenta como fenómeno secundario a diversas enfermedades entre las cuales se destacan las infecciones graves, las neoplasias y las catástrofes obstétricas. Se caracteriza por una activación difusa y simultánea de los sistemas endógenos de la coagulación y la fibrinólisis. El depósito de pequeños trombos en la circulación conduce finalmente a disfunción orgánica múltiple y en algunos casos a la muerte. Las manifestaciones clínicas pueden incluir fenómenos trombóticos y hemorrágicos. Se ha propuesto un puntaje de fácil aplicación para simplificar el diagnóstico de la entidad. El tratamiento incluye el control específico de la causa subyacente que favorece la aparición de la CID, el soporte con hemoderivados en pacientes con manifestaciones de sangrado y la anticoagulación terapéutica en pacientes con trombosis mayores. El desarrollo de CID es un factor pronóstico adverso que aumenta significativamente la tasa de mortalidad. En este artículo de revisión se incluyen los siguientes aspectos de la CID: historia, epidemiología, clasificación, entidades asociadas, fisiopatología, clínica, diagnóstico, tratamiento y pronóstico.

  2. Dosimetry in intravascular brachytherapy; Calculos dosimetricos em braquiterapia intravascular

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Laelia Pumilla Botelho

    2000-03-01

    Among the cardiovascular diseases responsible for deaths in the adult population in almost all countries of the world, the most common is acute myocardial infarction, which generally occurs because of the occlusion of one or more coronary arteries. Several diagnostic techniques and therapies are being tested for the treatment of coronary artery disease. Balloon angioplasty has been a popular treatment which is less invasive than traditional surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment).Recently, the idea of delivering high radiation doses to coronary arteries to avoid or delay restenosis has been suggested. Known as intravascular brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis in some patient populations. In order to study the radiation dosimetry in the patient and radiological protection for the attending staff for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, o,30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several candidate radionuclides as well. Two s tent sources (metallic prosthesis that put inside of patient's artery through angioplasty) employing {sup 32} P are also simulated. Advantages and disadvantages of the various radionuclides and source geometries are discussed. The dosimetry developed here will aid in the realization of the benefits obtained in patients for this promising new technology. (author)

  3. Ultrasound transducer shape has no effect on measurements of lumbar multifidus muscle size.

    Science.gov (United States)

    Worsley, Peter R; Smith, Nicholas; Warner, Martin B; Stokes, Maria

    2012-04-01

    Evidence is currently lacking for guidance on ultrasound transducer configuration (shape) when imaging muscle to measure its size. This study compared measurements made of lumbar multifidus on images obtained using curvilinear and linear transducers. Fifteen asymptomatic males (aged 21-32 years) had their right lumbar multifidus imaged at L3. Two transverse images were taken with two transducers (5 MHz curvilinear and 6 MHz linear), and linear and cross-sectional area (CSA) measurements were made off-line. Reliability of image interpretation was shown using intra-class correlation coefficients (0.78-0.99). Muscle measurements were compared between transducers using Bland and Altman plots and paired t-tests. Relationships between CSA and linear measurements were examined using Pearson's Correlation Coefficients. There were no significant differences (p > 0.05) in the measurements of the two transducers. Thickness and CSA measurements had small differences between transducers, with mean differences of 0.01 cm (SDdiff = 0.21 cm) and 0.03 cm(2) (SDdiff = 0.58 cm(2)) respectively. Width measures had a mean difference of 0.14 cm, with the linear transducer giving larger measures. Significant correlations (p transducers (r = 0.78-0.89). Measurements of multifidus at L3 were not influenced by the configuration of transducers of similar frequency. For the purposes of image interpretation, the curvilinear transducer produced better definition of the lateral muscle border, suggesting it as the preferable transducer for imaging lumbar multifidus. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Diagnosis of Parathyroid Adenoma Detected during Thyroid Ultrasound: The Role of Parathormone Measurement in Fine-Needle Aspiration Washout

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sung Soo; Kim, Eun Kyung; Kwak, Jin Young; Kim, Min Jung [Severance Hospital, Yonsei University, College of Medicine, Seoul (Korea, Republic of)

    2009-03-15

    With the widespread use of thyroid ultrasound, the detection rate of parathyroid incidentalomas as well as thyroid nodules has been on the increase. The differentiation between thyroid nodules and parathyroid nodules is occasionally difficult due to considerable overlap in terms of the sonographic findings. A case of parathyroid adenoma diagnosed with a measured parathyroid hormone level after fine needle aspiration washout is presented

  5. Validation of the Measurement of Intra-abdominal Fat Between Ultrasound and CT Scan in Women with Obesity and Infertility

    NARCIS (Netherlands)

    Kuchenbecker, Walter K. H.; Groen, Henk; Pel, Heleen; Bolster, Johanna H. T.; Wolffenbuttel, Bruce H. R.; Land, Jolande A.; Hoek, Annemieke; Corpeleijn, Eva

    2014-01-01

    Objective: To compare the means and changes over time of intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured by abdominal ultrasound (US) and computerized tomography (CT). Design and Methods: Prospective cohort study of 53 women with obesity and infertility undergoing a lifestyle

  6. Measurement of tibial nerve excursion during ankle joint dorsiflexion in a weight-bearing position with ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Carroll Matthew

    2012-03-01

    Full Text Available Abstract Background The ability of peripheral nerves to stretch and slide is thought to be of paramount importance to maintain ideal neural function. Excursion in peripheral nerves such as the tibial can be measured by analysis of ultrasound images. The aim of this study was to assess the degree of longitudinal tibial nerve excursion as the ankle moved from plantar flexion to dorsiflexion in a standardised weight-bearing position. The reliability of ultrasound imaging to measure tibial nerve excursion was also quantified. Methods The tibial nerve was imaged over two separate sessions in sixteen asymptomatic participants in a weight-bearing position. Longitudinal nerve excursion was calculated from a three-second video loop captured by ultrasound imaging using frame-by-frame cross-correlation analysis. Intraclass correlation coefficients (ICC with 95% confidence intervals (CI were used to assess the intra-rater reliability. Standard error of the measurement (SEM and smallest real difference (SRD were calculated to assess measurement error. Results Mean nerve excursion was 2.99 mm SEM ± 0.22 mm. The SRD was 0.84 mm for session 1 and 0.66 mm for session 2. Intra-rater reliability was excellent with an ICC = 0.93. Conclusions Assessment of real-time ultrasound images of the tibial nerve via frame-by-frame cross-correlation analysis is a reliable non-invasive technique to assess longitudinal nerve excursion. The relationship between foot posture and nerve excursion can be further investigated.

  7. Validation of the Measurement of Intra-abdominal Fat Between Ultrasound and CT Scan in Women with Obesity and Infertility

    NARCIS (Netherlands)

    Kuchenbecker, Walter K. H.; Groen, Henk; Pel, Heleen; Bolster, Johanna H. T.; Wolffenbuttel, Bruce H. R.; Land, Jolande A.; Hoek, Annemieke; Corpeleijn, Eva

    Objective: To compare the means and changes over time of intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured by abdominal ultrasound (US) and computerized tomography (CT). Design and Methods: Prospective cohort study of 53 women with obesity and infertility undergoing a lifestyle

  8. Three-dimensional ultrasound improves the accuracy of diameter measurement of the residual sac in EVAR patients

    DEFF Research Database (Denmark)

    Bredahl, Kim; Taudorf, M; Long, A

    2013-01-01

    Discrepancy between maximum diameters obtained with two-dimensional ultrasound and computed tomography (CT) after endovascular aneurysm repair (EVAR) is well known. The maximal diameter is ideally measured perpendicular to the centerline, a methodology so far only feasible with three-dimensional ...

  9. Evaluation of the ultrasound reproducibility as a method to measure the subcutaneous tissue of the nasal tip

    Directory of Open Access Journals (Sweden)

    Naves, Marcell de Melo

    2011-07-01

    Full Text Available Introduction: The previous evaluation of the patient's anatomy is crucial to achieve a sharp nasal tip in a rhinoplasty. The thickness of the subcutaneous tissue is indispensable for the esthetical harmony of the area. Techniques to measure such structures on the patient 'in vivo' are not found in literature. Objective: Evaluate the inter-observer inconsistency of the ultrasound method to measure the thickness of the subcutaneous tissue of the nasal tip by way of an ultrasound. Method: 47 volunteers were submitted to a nasal tip ultrasound performed by two radiology specialists, who used the same exam technique with a linear electronic transducer at a frequency between 5 and 9 MHz. The thickness of the subcutaneous tissue was evaluated by measuring the point with the highest protrusion of the largest alar cartilage dome towards skin. Prospective study. Results: The measurement averages of the subcutaneous tissue of the nasal tip achieved by the examiners did not show statistically significant differences (p = 0.5303. When analyzing the reproducibility between examiners, an interclass 'r'correlation coefficient (Pearson 0.9333, i.e., an excellent inter-observer reproducibility was found. Conclusion: The ultrasound proved to be reproducible and examiners satisfactorily agree about evaluating the thickness of the subcutaneous tissue of the skin, thus helping the surgeon perform the pre-surgical analysis and find the best surgical technique for each case.

  10. Laboratory testing in disseminated intravascular coagulation.

    Science.gov (United States)

    Favaloro, Emmanuel J

    2010-06-01

    The diagnosis of disseminated intravascular coagulation (DIC) relies on clinical signs and symptoms, identification of the underlying disease, the results of laboratory testing, and differentiation from other pathologies. The clinical features mainly depend on the underlying cause of the DIC. The laboratory diagnosis of DIC uses a combination of tests because no single test result alone can firmly establish or rule out the diagnosis. Global tests of hemostasis may initially provide evidence of coagulation activation and later in the process provide evidence of consumption of coagulation factors, but their individual diagnostic efficiency is limited. Fibrinolytic markers, in particular D-dimer, are reflective of activation of both coagulation and fibrinolysis, so that a normal finding can be useful for ruling-out DIC. Decreased levels of the natural anticoagulants (in particular, antithrombin and protein C) are frequently observed in patients with DIC, but their measurement is not normally incorporated into standard diagnostic algorithms. New tests are being explored for utility in DIC, and some additional tests may be useful on a case-by-case basis, depending on the proposed cause of the DIC or their local availability. For example, clot waveform analysis is useful but currently limited to a single instrument. Also, procalcitonin is an inflammatory biomarker that may be useful within the context of septic DIC, and activated factor X clotting time is an emerging test of procoagulant phospholipids that also seems to hold promise in DIC.

  11. Pulmonary intravascular blood volume changes through the cardiac cycle in healthy volunteers studied by cardiovascular magnetic resonance measurements of arterial and venous flow

    Directory of Open Access Journals (Sweden)

    Arheden Hakan

    2009-10-01

    Full Text Available Abstract Background This study aims to present a novel method for using cardiovascular magnetic resonance (CMR to non-invasively quantify the variation in pulmonary blood volume throughout the cardiac cycle in humans. Methods 10 healthy volunteers (7 males, 3 female, age range 21-32 years were studied. The blood flow in the pulmonary artery and all pulmonary veins was quantified during free breathing using phase contrast velocity encoded CMR. The difference in flow between the pulmonary artery and the pulmonary veins was integrated to calculate the change in pulmonary blood volume throughout the cardiac cycle. Results The stroke volumes in the pulmonary artery and the sum of the pulmonary veins were (mean ± SEM 103 ± 6 ml and 95 ± 6 ml, respectively. The pulmonary blood volume variation (PBVV was 48 ± 5 ml, and the PBVV expressed as percent of the pulmonary artery stroke volume was 46 ± 3%. The maximum increase in pulmonary blood volume occurred 310 ± 12 ms after the R-wave from the ECG (32 ± 2% of the cardiac cycle. PBVV did not correlate to change in cross-sectional area in the pulmonary artery (R2 = 0.03, p = 0.66. Conclusion It is feasible to non-invasively quantify the change in pulmonary blood volume during the cardiac cycle in humans using CMR. The average pulmonary blood volume variation in healthy volunteers was approximately 50 ml and this was approximately 50% of the stroke volume. Further studies are needed to assess the utility of the pulmonary blood volume variation as a measure for identifying cardiac and pulmonary vascular disease.

  12. A feasibility study of an intravascular imaging antenna to image atherosclerotic plaques in Swine using 3.0 T MRI.

    Directory of Open Access Journals (Sweden)

    Chen Zhang

    Full Text Available To investigate the feasibility of an intravascular imaging antenna to image abdominal aorta atherosclerotic plaque in swine using 3.0T magnetic resonance imaging (MRI.Atherosclerotic model was established in 6 swine. After 8 months, swine underwent an MR examination, which was performed using an intravascular imaging guide-wire, and images of the common iliac artery and the abdominal aorta were acquired. Intravascular ultrasound (IVUS was performed in the right femoral artery; images at the same position as for the MR examination were obtained. The luminal border and external elastic membrane of the targeted arteries were individually drawn in the MR and IVUS images. After co-registering these images, the vessel, lumen, and vessel wall areas and the plaque burden in the same lesions imaged using different modalities were calculated and compared. The diagnostic accuracy of intravascular MR examination in delineating the vessel wall and detecting plaques were analyzed and compared using IVUS.Compared with IVUS, good agreement was found between MRI and IVUS for delineating vessel, lumen, and vessel wall areas and plaque burden (r value: 0.98, 0.95, 0.96 and 0.91, respectively; P<0.001.Compared with IVUS, using an intravascular imaging guide-wire to image deep seated arteries allowed determination of the vessel, lumen and vessel wall areas and plaque size and burden. This may provide an alternative method for detecting atherosclerotic plaques in the future.

  13. Exploratory Analysis of Carbon Dioxide Levels, Ultrasound and Optical Coherence Tomography Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Young, M.; Mason, S.; Coble, C.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Patel, N.; Gibson, C.; Alexander, D.; Van Baalen, M.

    2017-01-01

    Enhanced screening for the Visual Impairment/Intracranial Pressure (VIIP) syndrome has been implemented to better characterize the ocular and vision changes observed in some long-duration crewmembers. This includes implementation of in-flight ultrasound in 2010 and optical coherence tomography (OCT) in 2013. Potential risk factors for VIIP include cardiovascular health, diet, anatomical and genetic factors, and environmental conditions. Carbon dioxide (CO2), a potent vasodilator, is chronically elevated on the International Space Station (ISS) relative to ambient levels on Earth, and is a plausible risk factor for VIIP. In an effort to understand the possible associations between CO2 and VIIP, this study explores the relationship of ambient CO2 levels on ISS compared to inflight ultrasound and OCT measures of the eye obtained from ISS crewmembers. CO2 measurements were aggregated from Operational Data Reduction Complex and Node 3 major constituent analyzers (MCAs) on ISS or from sensors located in the European Columbus module, as available. CO2 levels in the periods between each ultrasound and OCT session are summarized using timeseries metrics, including time-weighted means and variances. Partial least squares regression analyses are used to quantify the complex relationship between specific ultrasound and OCT measures and the CO2 metrics simulataneously. These analyses will enhance our understanding of the possible associations between CO2 levels and structural changes to the eye which will in turn inform future analysis of inflight VIIP data.

  14. Registration-based segmentation of three-dimensional ultrasound images for quantitative measurement of fetal craniofacial structure.

    Science.gov (United States)

    Chen, Hsin-Chen; Tsai, Pei-Yin; Huang, Hsiao-Han; Shih, Hui-Hsuan; Wang, Yi-Ying; Chang, Chiung-Hsin; Sun, Yung-Nien

    2012-05-01

    Segmentation of a fetal head from three-dimensional (3-D) ultrasound images is a critical step in the quantitative measurement of fetal craniofacial structure. However, two main issues complicate segmentation, including fuzzy boundaries and large variations in pose and shape among different ultrasound images. In this article, we propose a new registration-based method for automatically segmenting the fetal head from 3-D ultrasound images. The proposed method first detects the eyes based on Gabor features to identify the pose of the fetus image. Then, a reference model, which is constructed from a fetal phantom and contains prior knowledge of head shape, is aligned to the image via feature-based registration. Finally, 3-D snake deformation is utilized to improve the boundary fitness between the model and image. Four clinically useful parameters including inter-orbital diameter (IOD), bilateral orbital diameter (BOD), occipital frontal diameter (OFD) and bilateral parietal diameter (BPD) are measured based on the results of the eye detection and head segmentation. Ultrasound volumes from 11 subjects were used for validation of the method accuracy. Experimental results showed that the proposed method was able to overcome the aforementioned difficulties and achieve good agreement between automatic and manual measurements.

  15. A real-time measure of cavitation induced tissue disruption by ultrasound imaging backscatter reduction.

    Science.gov (United States)

    Hall, Timothy L; Fowlkes, J Brian; Cain, Charles A

    2007-03-01

    A feedback method for obtaining real-time information on the mechanical disruption of tissue through ultrasound cavitation is presented. This method is based on a substantial reduction in ultrasound imaging backscatter from the target volume as the tissue structure is broken down. Ex-vivo samples of porcine liver were exposed to successive high-intensity ultrasound pulses at a low duty cycle to induce mechanical disruption of tissue parenchyma through cavitation (referred to as histotripsy). At the conclusion of treatment, B-scan imaging backscatter was observed to have decreased by 22.4 +/- 2.3 dB in the target location. Treated samples of tissue were found to contain disrupted tissue corresponding to the imaged hypoechoic volume with no remaining discernable structure and a sharp boundary. The observed, substantial backscatter reduction may be an effective feedback mechanism for assessing treatment efficacy in ultrasound surgery using pulsed ultrasound to create cavitation.

  16. Body composition in sport: a comparison of a novel ultrasound imaging technique to measure subcutaneous fat tissue compared with skinfold measurement.

    Science.gov (United States)

    Müller, Wolfram; Horn, Martin; Fürhapter-Rieger, Alfred; Kainz, Philipp; Kröpfl, Julia M; Maughan, Ronald J; Ahammer, Helmut

    2013-11-01

    Extremely low weight and rapid changes in weight and body composition have become major concerns in many sports, but sufficiently accurate field methods for body composition assessment in athletes are missing. This study aimed to explore the use of ultrasound methods for assessment of body fat content in athletes. 19 female athletes (stature: 1.67(± 0.06) m, weight: 59.6(± 7.6) kg; age: 19.5(± 3.3) years) were investigated by three observers using a novel ultrasound method for thickness measurement of uncompressed subcutaneous adipose tissue and of embedded structures. Two observers also measured skinfold thickness at eight International Society for the Advancement of Kinanthrometry (ISAK) sites; mean skinfold values were compared to mean subcutaneous adipose tissue thicknesses measured by ultrasound. Interobserver reliability of imaging and evaluation obtained by this ultrasound technique: intraclass correlation coefficient ICC=0.968 (95% CI 0.957 to 0.977); evaluation of given images: ICC=0.997 (0.993 to 0.999). Skinfold compared to ultrasound thickness showed that compressibility of subcutaneous adipose tissue depends largely on the site and the person: regression slopes ranged from 0.61 (biceps) to 1.59 (thigh) and CIs were large. Limits of agreement ranged from 2.6 to 8.6 mm. Regression lines did not intercept the skinfold axis at zero because of the skin thickness being included in the skinfold. The four ISAK trunk sites caused ultrasound imaging problems in 13 of 152 sites (8 ISAK sites, 19 athletes). The ultrasound method allows measurement of uncompressed subcutaneous adipose tissue thickness with an accuracy of 0.1-0.5 mm, depending on the probe frequency. Compressibility of the skinfold depends on the anatomical site, and skin thickness varies by a factor of two. This inevitably limits the skinfold methods for body fat estimation. Ultrasound accuracy for subcutaneous adipose tissue measurement is limited by the plasticity of fat and furrowed tissue

  17. Common fetal measurements: A comparison between ultrasound and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Parkar, Anagha P. (Dept. of Radiology, Haukeland Univ. Hospital, Bergen (Norway)); Olsen, Oeystein E.; Rosendahl, Karen (Diagnostic Radiology, Great Ormond Street Hospital for Children, London (United Kingdom)), e-mail: rosenk@gosh.nhs.uk; Gjelland, Knut; Kiserud, Torvid (Fetal Medicine Unit, Dept. of Obstetrics and Gynecology, Haukeland Univ. Hospital, Bergen (Norway))

    2010-01-15

    Background: Ultrasound has been the method of choice for antenatal fetal assessment for the past three decades; however, problems may arise in cases of oligohydramnion, unfavorable position of the fetus, and maternal obesity. Purpose: To compare ultrasound (US) and magnetic resonance imaging (MRI) for common fetal measurements at 19-30 weeks' gestation, and to assess the effect of high maternal body-mass index (BMI). Material and Methods: 59 low-risk singleton pregnancies were enrolled in a prospective blinded cross-sectional study. In a first session, an experienced obstetrician used a high-resolution US technique and in a second session on the same day MRI was used to measure biparietal diameter (BPD), head circumference (HC), mean abdominal diameter (MAD), abdominal circumference (AC), and femur length (FL). Inter- and intraobserver and intermodality variability was determined using Bland-Altman plots. The effect of maternal BMI was assessed using Spearman's statistics. Results: A total of 45 women aged 19-43 years (median 29 years) attended both US and MRI at median 22 weeks' gestation. The mean differences between US and MRI were 1.6 mm for HC (95% confidence interval [CI] -1.0, 4.3 mm), 1 mm for AC (95% CI -0.2, 4.0 mm), 0.2 mm for MAD (95% CI -0.7, 1.2 mm), 2.2 mm for BPD (95% CI 1.7, 2.7 mm), and 4.6 mm for FL (95% CI 2.9, 6.4 mm). Maternal BMI did not affect the results (Spearman' rho 0.054-0.277; P=NS). The intraobserver agreement for all MRI measurements was acceptable, except for FL, while the interobserver agreement was poor. Conclusion: There was good agreement between US and MRI for common fetal measurements, but not for all (i.e., BPD and particularly FL). MRI had a poor interobserver agreement, underscoring the need for technical refinement and reference ranges specifically established for MRI

  18. Serial Measurements of Splanchnic Vein Diameters in RatsUsing High-Frequency Ultrasound

    Directory of Open Access Journals (Sweden)

    Bridget M Seitz

    2016-05-01

    Full Text Available The purpose of this study was to investigate serial ultrasound imaging in rats as a fully non-invasive method to 1 quantify the diameters of splanchnic veins in real time as an indirect surrogate for the capacitance function of those veins, and 2 assess the effects of drugs on venous dimensions. A 21 MHz probe was used on anesthetized male Sprague-Dawley rats to collect images containing the portal vein (PV, superior mesenteric vein (SMV, abdominal inferior vena cava (IVC, and splenic vein (SpV; used as a landmark in timed studies and the abdominal aorta (AA. Stable landmarks were established that allowed reproducible quantification of cross-sectional diameters within an animal. The average diameters of vessels measured every 5 minutes over 45 minutes remained within 0.75±0.15% (PV, 0.2±0.09% (SMV, 0.5±0.12% (IVC and 0.38±0.06% (AA of baseline (PV: 2.0±0.12 mm; SMV: 1.7±0.04 mm; IVC: 3.2±0.1 mm; AA: 2.3±0.14 mm. The maximal effects of the vasodilator sodium nitroprusside (SNP; 2 mg/kg, i.v. bolus on venous diameters were determined 5 minutes post SNP bolus; the diameters of all noted veins were significantly increased by sodium nitroprusside, while mean arterial pressure decreased 29±4 mmHg. By contrast, administration of the venoconstrictor sarafotoxin (S6c; 5 ng/kg, i.v. bolus significantly decreased PV and SpV, but not IVC, SMV or AA, diameters 5 minutes post S6c bolus; mean arterial pressure increased by 6±2 mmHg. In order to determine if resting splanchnic vein diameters were stable over much longer periods of time, vessel diameters were measured every two weeks for 8 weeks. Measurements were found to be highly reproducible within animals over this time period. Finally, to evaluate the utility of vein imaging in a chronic condition, images were acquired from 4-week deoxycorticosterone acetate salt (DOCA-salt hypertensive and normotensive (SHAM control rats. All vessel diameters increased from baseline while mean arterial pressure

  19. Application of intravascular ultrasound in analysis on influencing factors of prognosis in patients with different coronary artery in-stent restenosis%血管内超声在冠状动脉支架术后再狭窄患者预后影响因素分析中的应用

    Institute of Scientific and Technical Information of China (English)

    崔燕; 史永锋; 郭子源; 刘斌; 王金鹏; 赵雷; 王珺楠; 朴金花

    2016-01-01

    目的:收集应用血管内超声技术(IVUS)检测发生冠状动脉支架术后支架内再狭窄(ISR)患者的影像学数据及相关资料,分析 ISR 的危险因素,提出合理的干预策略。方法:将50例 ISR 患者随机分为 ISR≤50%组(药物组)14例和 ISR>50%组36例(根据患者意愿及经济情况分为药物球囊治疗组16例和支架治疗组20例)。应用 IVUS 虚拟组织学技术,比较各组患者采用不同治疗方法治疗前后斑块面积、病变位置、组织构成和血栓等影响预后的因素,并随访6个月后的数据变化。结果:IVUS 检测,与术前比较,行介入干预治疗的ISR 患者斑块面积和斑块负荷均明显减少(P <0.05),但药物球囊治疗组患者斑块缩减程度小于支架治疗组(P <0.05),纤维组织成分无明显变化(P >0.05),钙化组织所占比例升高,但差异无统计学意义(P >0.05)。结论:病变狭窄程度高且纤维成分多,斑块成分不均一且分布弥漫伴迂曲钙化的患者 ISR 发生率均较高。ISR发生与斑块壁厚薄、脂质成分含量、斑块不稳定程度和坏死组织多少无明显关联。%Objective:To collect the imaging data and related materials of the patients with in-stent restenosis (ISR)after coronary artery stent operation with intravascular ultrasound (IVUS),and to analyze the risk factors of ISR,and to propose the reasonable intervention strategies.Methods:Fifty patients with ISR were divided into ISR ≤ 50% drug group (n = 14 )and ISR > 50% drug group (n = 36),including drug-coated balloon therapy group (n=16)and stent treatment group (n=20);IVUS virtual organization technology was used to compare the plaque area,location,tissue composition,thrombus and other factors of the patients in various groups after treatment;the data changes after 6 months of follow-up were analyzed.Results:The IVUS results showed the plaque areas and plaque loads of the

  20. Effects of fluvastatin extended release tablets on the intermediate lesions of patients with coronary artery disease evaluated by virtual histology-intravascular ultrasound%虚拟组织学-血管内超声观察氟伐他汀缓释片对冠状动脉临界病变的影响

    Institute of Scientific and Technical Information of China (English)

    杨海波; 赵晓燕; 赵荫涛; 张金盈; 李凌

    2012-01-01

    Objective To obserrve the effect of fluvastatin extended release tablets on the intermediate lesions of patients with coronmy artery disease evaluated by virtual histology-intravascular ultrasound(VH-IVUS).Methods Forty-three patients with intermediate lesions of acute coronary syndrome (ACS) were examined by coronary angiography (CAG) and VH-IVUS,the target vessel diameter stenosis (DS) were analyzed using quantitative coronary angiography (QCA).The plaque burden,minimal luman area(MLA) and composition variation were analyzed using VH-IVUS.All selected patients were treated with 80 mg fluvastatin extended release tablets for 6 months.The serum lipid levels of patients before and after the treatment were compared.After 6 months the reexamination of the vessel by CAG and VH-IVUS were performed.Results After 6 months,the TC,LDL-C and TG levels were significantly decreased,while the HDL-C level was significantly increased (P < 0.05).The VH-IVUS analysis showed that the proportion of necrosis core was decreased from (22.6 ± 7.5) % to (15.1 ± 7.1) %(P < 0.05) and the proportion of fibrous tissue was increased from (44.4 ± 9.7) % to (51.2 ± 9.9) %(P < 0.05).There has no significant change in DS,the plaque burden,MLA,the proportion of dense calcium or fibro-fatty tissue.Conclusions The treatment of fluvastatin for 6 months might stable plaque and prevent the progression of atherosclerosis in patients with intermediate coronary artery lesions.%目的 应用虚拟组织学-血管内超声(VH-IVUS)观察氟伐他汀缓释片对冠状动脉临界病变患者斑块进展及其成分的影响.方法 选择经冠状动脉造影(CAG)和VH-IVUS检查无需介入治疗的冠状动脉临界病变患者43例,给予氟伐他汀缓释片(80 mg)治疗6个月后复查CAG及VH-IVUS,比较治疗前后血脂、定量冠状动脉造影(QCA)分析目标血管段直径狭窄率(DS)变化,VH-IVUS分析斑块负荷、最小管腔面积(MLA)、斑块成分变化.结果

  1. 血脂与血管内超声-虚拟组织学评价冠状动脉粥样硬化斑块性质%Correlation between blood lipid and intravascular ultrasound-virtual histology in assessing characteristics of coronary atherosclerotic plaques

    Institute of Scientific and Technical Information of China (English)

    武丽娜; 李新华; 赵晓燕

    2012-01-01

    目的:探讨血脂和血管内超声-虚拟组织(IVUS-VH)学评价急性冠脉综合征(ACS)和稳定性心绞痛(SA)患者冠状动脉粥样硬化斑块性质.方法:对44例ACS患者及22例SA患者行IVUS-VH分析,并对其血清高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、脂蛋白a [LP(a)]进行测定,计算LDL-C/HDL-C比值,分析冠状动脉粥样硬化斑块坏死核心(NC)所占的比例与LP(a)、LDL-C/HDL-C的相关关系.结果:ACS组斑块中NC和钙化组织比例明显高于SA组(t=4.669、9.894,P<0.001),而纤维组织及纤维脂肪组织则明显低于SA组(t=7.184、5.290,P<0.001).ACS组患者血清LDL-C/HDL-C、LP(a)水平高于SA组患者(t=3.512、19.139,P<0.001).ACS组患者冠状动脉粥样硬化斑块中NC比例与血清LP(a)水平有显著的相关性(r=0.549,P<0.001).结论:LP(a)可能代替IVUS-VH帮助了解冠状动脉粥样硬化斑块的性质.%Aim: To investigate the correlation between blood lipid and intravascular ultrasound-virtual histology(IVUS-VH) in assessing characteristics of the coronary atherosclerotic plaques in patients with acute coronary syndrome(ACS) and stable angina(SA).Methods:The coronary atherosclerotic plaques in 44 patients with ACS and 22 patients with SA were tested by IVUS-VH,and the serum levels of HDL-C,LDL-C and LP(a) were detected. The ratio of LDL-C/HDL-C was calculated.The correlation of the percentage of necrotic core and LP(a),LDL-C/HDL-C was analyzed,respectively.Results:The percentages of necrotic core and dense calcium tissue in ACS were significantly higher than those in SA group (t=4.669,9.894,P<0.001),but the percentages of fibrous tissue and fibro-fatty tissue in ACS were significantly lower than those in SA group(t=7.184,5.290,P<0.001).There were obvious differences in serum level of LP(a) and the ratio of LDL-C/HDL-C between ACS group and SA group (t=3.512,19.139,P<0.001). There was a significant positive correlation between the percentage of necrotic core

  2. Measurement of viscoelastic properties of in vivo swine myocardium using lamb wave dispersion ultrasound vibrometry (LDUV).

    Science.gov (United States)

    Urban, Matthew W; Pislaru, Cristina; Nenadic, Ivan Z; Kinnick, Randall R; Greenleaf, James F

    2013-02-01

    Viscoelastic properties of the myocardium are important for normal cardiac function and may be altered by disease. Thus, quantification of these properties may aid with evaluation of the health of the heart. Lamb wave dispersion ultrasound vibrometry (LDUV) is a shear wave-based method that uses wave velocity dispersion to measure the underlying viscoelastic material properties of soft tissue with plate-like geometries. We tested this method in eight pigs in an open-chest preparation. A mechanical actuator was used to create harmonic, propagating mechanical waves in the myocardial wall. The motion was tracked using a high frame rate acquisition sequence, typically 2500 Hz. The velocities of wave propagation were measured over the 50-400 Hz frequency range in 50 Hz increments. Data were acquired over several cardiac cycles. Dispersion curves were fit with a viscoelastic, anti-symmetric Lamb wave model to obtain estimates of the shear elasticity, μ(1), and viscosity, μ(2) as defined by the Kelvin-Voigt rheological model. The sensitivity of the Lamb wave model was also studied using simulated data. We demonstrated that wave velocity measurements and Lamb wave theory allow one to estimate the variation of viscoelastic moduli of the myocardial walls in vivo throughout the course of the cardiac cycle.

  3. Acoustic power measurement of high-intensity focused ultrasound transducer using a pressure sensor.

    Science.gov (United States)

    Zhou, Yufeng

    2015-03-01

    The acoustic power of high-intensity focused ultrasound (HIFU) is an important parameter that should be measured prior to each treatment to guarantee effective and safe outcomes. A new calibration technique was developed that involves estimating the pressure distribution, calculating the acoustic power using an underwater pressure blast sensor, and compensating the contribution of harmonics to the acoustic power. The output of a clinical extracorporeal HIFU system (center frequency of ~1 MHz, p+ = 2.5-57.2 MPa, p(-) = -1.8 to -13.9 MPa, I(SPPA) = 513-22,940 W/cm(2), -6 dB size of 1.6 × 10 mm: lateral × axial) was measured using this approach and then compared with that obtained using a radiation force balance. Similarities were found between each method at acoustic power ranging from 18.2 W to 912 W with an electrical-to-acoustic conversion efficiency of ~42%. The proposed method has advantages of low weight, smaller size, high sensitivity, quick response, high signal-to-noise ratio (especially at low power output), robust performance, and easy operation of HIFU exposimetry measurement.

  4. Prostate Ultrasound

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, also called transrectal ultrasound, provides ...

  5. Ultrasound measurement of the corpus callosum and neural development of premature infants*

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Shikao Cao; Jiaoran Liu; Zhifang Du; Zhimei Guo; Changjun Ren

    2013-01-01

    Length and thickness of 152 corpus cal osa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus cal osum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus cal osum length as wel as thickness of the genu and splenium increased with gesta-tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus cal osum de-velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus cal osum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose ges-tational age was 34 weeks or less. Corpus cal osum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus cal osum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus cal osum growth in premature infants is associated with neurobehavioral de-velopment during the early extrauterine stage.

  6. [A method for studying intravascular platelet aggregation in vitro].

    Science.gov (United States)

    Ikonnikova, E I; Chernousova, L A; Moshkina, I R

    1999-06-01

    A simple available method for evaluating intravascular platelet aggregation is proposed. It consists in graphic recording of disaggregation of platelet-rich citrate plasma, which indicates the degree of intravascular aggregation. Intravascular aggregation is notably increased in coronary patients and negligible in normal subjects. The method may be used for the diagnosis of diseases with a high thrombogenic risk.

  7. Quantitative head ultrasound measurements to determine thresholds for preterm neonates requiring interventional therapies following intraventricular hemorrhage

    Science.gov (United States)

    Kishimoto, Jessica; Fenster, Aaron; Salehi, Fateme; Romano, Walter; Lee, David S. C.; de Ribaupierre, Sandrine

    2016-04-01

    Dilation of the cerebral ventricles is a common condition in preterm neonates with intraventricular hemorrhage (IVH). This post hemorrhagic ventricle dilation (PHVD) can lead to lifelong neurological impairment through ischemic injury due to increased intracranial pressure and without treatment, can lead to death. Clinically, 2D ultrasound (US) through the fontanelles ('soft spots') of the patients are serially acquired to monitor the progression of the ventricle dilation. These images are used to determine when interventional therapies such as needle aspiration of the built up cerebrospinal fluid (CSF) ('ventricle tap', VT) might be indicated for a patient; however, quantitative measurements of the growth of the ventricles are often not performed. There is no consensus on when a neonate with PHVD should have an intervention and often interventions are performed after the potential for brain damage is quite high. Previously we have developed and validated a 3D US system to monitor the progression of ventricle volumes (VV) in IVH patients. We will describe the potential utility of quantitative 2D and 3D US to monitor and manage PHVD in neonates. Specifically, we will look to determine image-based measurement thresholds for patients who will require VT in comparison to patients with PHVD who resolve without intervention. Additionally, since many patients who have an initial VT will require subsequent interventions, we look at the potential for US to determine which PHVD patients will require additional VT after the initial one has been performed.

  8. The skin-to-calyx distance measured by renal ct scan and ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Chen Jen; Mazzucchi, Eduardo; Payão, Fabio; Gomes, Andrea Cavalanti; Baroni, Ronaldo Hueb; Torricelli, Fabio Cesar; Vicentini, Fabio Carvalho; Srougi, Miguel [Hospital das Clínicas, University of Sao Paulo Medical School, Sao Paulo, SP (Brazil)

    2014-03-15

    Purpose: We developed a stereotactic device to guide the puncture for percutaneous nephrolithotripsy, which uses the distance from the target calyx to its perpendicular point on skin (SCD) to calculate the needle´s entry angle. This study seeks to validate the use of measurements obtained by ultrasound (US) and computerized tomography (CT) for needle´s entry angle calculation and to study factors that may interfere in this procedure. Materials and Methods: Height, weight, abdominal circumference, CT of the urinary tract in dorsal decubitus (DD) and ventral decubitus (VD), and US of the kidneys in VD were obtained from thirty-five renal calculi patients. SCD obtained were compared and correlated with body-mass index (BMI). Results: BMI was 28.66 ± 4.6 Kg/m2. SCD on CT in DD was 8.40 ± 2.06cm, in VD was 8.32 ± 1.95cm, in US was 6.74 ± 1.68cm. SCD measured by US and CT were statistically different (p < 0.001), whereas between CT in DD and VD were not. SCD of the lower calyx presented moderate correlation with BMI. Conclusion: SCD obtained by CT in ventral and dorsal decubitus may be used for calculation of the needle´s entry angle. SCD obtained by US cannot be used. A rule for the correlation between BMI and the SCD could not be determined. (author)

  9. Individually customised fetal weight charts derived from ultrasound measurements: the Generation R Study.

    Science.gov (United States)

    Gaillard, Romy; de Ridder, Maria A J; Verburg, Bero O; Witteman, Jacqueline C M; Mackenbach, Johan P; Moll, Henriëtte A; Hofman, Albert; Steegers, Eric A P; Jaddoe, Vincent W V

    2011-12-01

    Maternal and fetal characteristics are important determinants of fetal growth potential, and should ideally be taken into consideration when evaluating fetal growth variation. We developed a model for individually customised growth charts for estimated fetal weight, which takes into account physiological maternal and fetal characteristics known at the start of pregnancy. We used fetal ultrasound data of 8,162 pregnant women participating in the Generation R Study, a prospective, population-based cohort study from early pregnancy onwards. A repeated measurements regression model was constructed, using backward selection procedures for identifying relevant maternal and fetal characteristics. The final model for estimating expected fetal weight included gestational age, fetal sex, parity, ethnicity, maternal age, height and weight. Using this model, we developed individually customised growth charts, and their corresponding standard deviations, for fetal weight from 18 weeks onwards. Of the total of 495 fetuses who were classified as small size for gestational age (measurements in a large population-based study to fit a model to construct individually customised growth charts, taking into account physiological maternal and fetal characteristics. These charts might be useful for use in epidemiological studies and in clinical practice.

  10. Transabdominal ultrasound measurement of rectal diameter is dependent on time to defecation in constipated children

    DEFF Research Database (Denmark)

    Modin, Line; Dalby, Kasper; Walsted, Anne-Mette;

    2015-01-01

    AIM: To study whether diurnal variations and time in relation to defecation has to be taken into account when measurements of rectal diameter are used to determine faecal impaction in constipated children. METHODS: Repeated ultrasound measures of rectal diameter were performed in 28 children (14...... constipated/14 healthy, aged between 4 and 12 years) every third hour during 24 h. After defecation, three additional scans were performed at 1-h intervals. RESULTS: No diurnal variation in rectal diameter was found in the healthy group. In the constipated group, mean rectal diameter was significantly larger...... at 2 pm (P = 0.038) and 5 pm (P = 0.006). There were significant differences between rectal diameter in the healthy group and the constipated group at 2 pm (P = 0.016) and 5 pm (P = 0.027). When we omitted the rectal diameter of five constipated children who had their first bowel movement after 5 pm...

  11. Utilization of an ultrasound beam steering angle for measurements of tissue displacement vector and lateral displacement

    Directory of Open Access Journals (Sweden)

    Chikayoshi Sumi

    2010-09-01

    Full Text Available Chikayoshi SumiDepartment of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Tokyo, JapanAbstract: A number of ultrasonic displacement/velocity measurement methods have been extensively developed for measurements of blood flow, tissue motion, and strain. Lateral modulation (LM methods have also been reported using steered, crossed beams, and these methods permit measurements of displacement vectors. In this report, a new beam steering method for the transmission and reception of ultrasound is proposed, which can enable measurements of lateral displacements and of arbitrary displacement vectors with a very high degree of accuracy. Because this beam steering method uses only a steering angle, this method is referred to as ASTA. With ASTA, the number of available methods to obtain a displacement vector measurement is limited to previously developed block-matching methods, such as the multidimensional cross-spectrum phase gradient method, and the multidimensional autocorrelation method (MAM and the multidimensional Doppler method (MDM using a block-matching method (the methods using block matching are referred to as MAMb and MDMb, respectively. Being dependent on the measurement method, only a lateral displacement measurement can be made even if the methods are multidimensional, ie, previously developed MAM and MDM using a moving average and a mirror setting of the obtained steered beams, and one-dimensional (1D, such as an autocorrelation method. Considerations of beamforming schemes using LM and ASTA show that the simple ASTA beamforming method increases capabilities for real-time measurements and requires a small physical aperture when compared with LM. For lateral displacement measurements (eg, blood flow in a carotid artery, a lateral coordinate must correspond to the direction of the target’s lateral motion, and the steering angle used is as large as possible to increase the measurement accuracy

  12. Reliability of ultrasound imaging for the measurement of abdominal muscle thickness in typically developing children

    Directory of Open Access Journals (Sweden)

    M. Unger

    2010-02-01

    Full Text Available Introduction: A bdominal muscles are key to both posture andgait in both children with typical development (TD and with disabilities.Ultrasound (US imaging is a potential non-invasive method for investigatingactivity in these muscles. This study therefore aimed to determine the inter-tester and intra-tester reliability of B-mode US for investigating transverseabdominus (TrA , rectus abdominus (RA and external- (EO and internaloblique (IO muscle activity in children with TD. Design: A  prospective cor-relational descriptive study.  Participants:  Eighty six, 6-13year old children from one private and one public mainstream school. Outcome measures: Two sets of B-mode US images where captured per subject during rest and during head-up, resisted head-up and resisted sling activities. Intra-class Correlation Coefficients (ICC and standard error of measurement (SEM were used to analyse the data. Results: Good correlation was found for both test - retest condi-tions for all four muscles tested during rest: 0.91(TrA ; 0.90(IO; 0.91(EO; 0.94(RA for intra-tester reliability and0.74(TrA ; 0.88(IO; 0.74(EO; 0.83(RA for inter-tester reliability. Repeatability of thickness measures during activity however showed variation in recruitment patterns. A  significant correlation was found between age and BMI andresting abdominal muscle thickness (p<0.001. Conclusion: The study supports the reliability of US measurement of resting abdominal muscles and of the RA  under active conditions in children aged six to 13. However the stability o measurement of the other muscles under active conditions still needs to be established.

  13. Correlation Between Transperineal 3-Dimensional Ultrasound Measurements of Levator Hiatus and Female Sexual Function.

    Science.gov (United States)

    Aydin, Serdar; Bakar, Rabia Zehra; Arioğlu Aydin, Çağri; Ateş, Seda

    2017-03-09

    The aim of this study is to investigate the association of sexual functions with levator hiatus biometry measurements and levator ani muscle defect. In 62 heterosexual, sexually active premenopausal women without pelvic floor disorders or urinary incontinence, 3-dimensional transperineal ultrasound imaging was used. Two 3-dimensional volumes were recorded, one at rest and one on Valsalva maneuver. Levator biometry measurements and levator defect were evaluated in an axial plane. Sexual function was assessed by a validated questionnaire, Female Sexual Function Index (FSFI). The primary outcome measure was correlation of sexual functions with the levator hiatus area, transverse and anteroposterior diameters, levator ani muscle thickness, vaginal length, and changes in measurements with Valsalva and levator defect. Forty-two women (67.7%) had low total FSFI scores (<26.55). Levator defect rates were similar in female sexual dysfunction (7/42, 16.7%) and women without female sexual dysfunction (5/20, 25%). The FSFI was negatively and weakly correlated with Δhiatal anteroposterior diameter (r = -0.33, P < 0.009) in the study population. There was a weak and inverse correlation between Δhiatal anteroposterior diameter and arousal (r = -0.35, P < 0.002), desire (r = -0.38, P < 0.001), and orgasm (r = -0.33, P < 0.007). Pain and lubrication did not correlate with any measurement. Hiatal area and diameters at rest are not related to sexual functions. Changes in anteroposterior diameter of the levator hiatus during Valsalva, which may be a sign of pelvic floor laxity or levator muscle weakness, are weakly associated with sexual functions, particularly desire, arousal, and orgasm domains.

  14. In vivo measurement of rotator cuff tendon strain with ultrasound elastography: an investigation using a porcine model.

    Science.gov (United States)

    Hatta, Taku; Yamamoto, Nobuyuki; Sano, Hirotaka; Itoi, Eiji

    2014-09-01

    To clarify the relationship between the strain ratio measured by ultrasound elastography and the mechanical properties of the tendon measured by a universal testing machine. We also attempted to determine the effect of the type and depth of soft tissue overlying the tendon on the elastographic measurement. Twelve fresh porcine shoulders were prepared. Elastographic measurement was performed on the infraspinatus tendon by manually applying repetitive compressions from an ultrasound probe with an acoustic coupler consisting of an elastomer with definite elasticity as a reference material. The strain ratio, defined as tendon/reference strain, was obtained by 4 different approaches: with the probe placed on the skin, on the subcutaneous fat after removing the skin, on the muscle after removing the subcutaneous fat, and directly on the tendon. The strain ratios measured by these approaches were compared statistically. The relationship between the depth of the tendon measured on elastography and the strain ratio was also investigated. We also attempted to clarify the relationship between the strain ratio of the tendon and its elastic property. The tendon was mounted on a testing machine, and compressive force was applied. Tendon compliance was calculated as the reciprocal of the Young modulus in the range of 5% to 10% strain, which was compared to its strain ratio. The tendon/reference strain ratio significantly correlated with the tendon compliance (r = 0.73; P tendon level (P = .8). Our results indicated that the strain ratio of the rotator cuff tendon could be measured with minimal influence by overlying soft tissues if its depth from the skin was less than 22 mm. We believe that ultrasound elastography would be a useful tool for assessment of tendon elasticity in clinical practice. © 2014 by the American Institute of Ultrasound in Medicine.

  15. Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares.

    Science.gov (United States)

    Östling, Gerd; Persson, Margaretha; Hedblad, Bo; Gonçalves, Isabel

    2013-11-01

    Grey scale median (GSM) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut-off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with Adobe Photoshop(®) and with Artery Measurement System (AMS) on duplex ultrasound images of 100 consecutive medium- to large-sized carotid plaques of the Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for Adobe Photoshop(®) and AMS, respectively. Mean difference was 20·45 (95% CI: 19·17-21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi-square test revealed a kappa value of 0·68 when studying quartiles of GSM. The intra-observer variability was 1·9% for AMS and 2·5% for Adobe Photoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries.

  16. Confiabilidade da medida de espessuras musculares pela ultrassonografia Reliability of muscle thickness measurements using ultrasound

    Directory of Open Access Journals (Sweden)

    Paulo Sergio Chagas Gomes

    2010-02-01

    Full Text Available OBJETIVO: Determinar a confiabilidade das medidas de espessuras dos músculos flexores e extensores do cotovelo e joelho pela ultrassonografia (US, quantificando o erro típico associado a essas medidas (ETM. MÉTODOS: A confiabilidade (duas medidas interdias foi determinada em 15 voluntários aparentemente saudáveis (oito mulheres, 33,9 ± 11,4 anos, 76 ± 21kg, 170 ± 10cm. As imagens da musculatura flexora (FC e extensora do cotovelo (EC e flexora (FJ e extensora do joelho (EJ foram obtidas pela US bidimensional no modo B, utilizando transdutor de 7,5MHz. As espessuras do tecido muscular compreendidas entre as interfaces com o osso e com o tecido adiposo foram medidas em sítios anatômicos identificados e registrados para ser repetidos na segunda medida. RESULTADOS: A ANOVA não identificou diferenças significativas entre as medidas repetidas. Os coeficientes de correlação intraclasse foram FC = 0,970, EC = 0,971, FJ = 0,555 e EJ = 0,929 (P PURPOSE: To determine the reliability of muscle thickness measurements of elbow and knee flexors and extensors using ultrasound, and to quantify the typical error associated to the measurements (TEM. METHODS: The test-retest reliability was determined in 15 apparently healthy volunteers (8 women, 34 ± 11 years, 76 ± 21 kg, 170 ± 10 cm. The images of elbow flexors (EF and extensors (EE and knee flexors (KF and extensors (KE were obtained using a two dimensional mode B ultrasound instrument with a 7.5 MHz transducer. Muscle thickness between the adipose tissue and bone interfaces were measured at anatomical landmarks previously identified and recorded to assure the exact site for the retest. RESULTS: ANOVA did not identify any significant differences between the repeated measurements. Intraclass correlation coefficients (ICC of each pair of measure were EF = 0.970, EE = 0.971, KF = 0.555 e KE = 0.929 (P < 0.05 for all. The coefficients of variation were 3.9 %, 6.1 %, 6.6 % e 4.6 %, and TEM 1.3 mm, 1

  17. Exploratory Analysis of Carbon Dioxide Levels, Ultrasound and Optical Coherence Tomography Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Coble, C.; Mason, S.; Young, M.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Patel, N.; Gibson, C.; Alexander, D.; Van Baalen, M.

    2017-01-01

    Carbon dioxide (CO2) levels on board the International Space Station (ISS) have typically averaged 2.3 to 5.3 mmHg, with large fluctuations occurring over periods of hours and days. CO2 has effects on cerebral vascular tone, resulting in vasodilation and alteration of cerebral blood flow (CBF). Increased CBF leads to elevated intracranial pressure (ICP), a factor leading to visual disturbances, headaches, and other central nervous system symptoms. Ultrasound of the optic nerve and optical coherence tomography (OCT) provide surrogate measurements of ICP; in-flight measurements of both were implemented as enhanced screening tools for the Visual Impairment/Intracranial Pressure (VIIP) syndrome. This analysis examines the relationships between ambient CO2 levels on ISS, ultrasound and OCT measures of the eye in an effort to understand how CO2 may possibly be associated with VIIP and to inform future analysis of in-flight VIIP data.

  18. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces ... of page What are some common uses of the procedure? A transrectal ultrasound of the prostate gland ...

  19. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... are the limitations of Pelvic Ultrasound Imaging? What is Pelvic Ultrasound Imaging? Ultrasound is safe and painless, ... through the blood vessels. top of page How is the procedure performed? Transabdominal: For most ultrasound exams, ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate gland ... of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography , ...

  1. Ultrasound - Breast

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Breast Ultrasound imaging of the breast uses sound waves ... the Breast? What is Ultrasound Imaging of the Breast? Ultrasound is safe and painless, and produces pictures ...

  2. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  3. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  4. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces ... of page What are some common uses of the procedure? A transrectal ultrasound of the prostate gland ...

  5. Ultrasound measurement of the size of the anterior tibial muscle group: the effect of exercise and leg dominance

    LENUS (Irish Health Repository)

    McCreesh, Karen

    2011-09-13

    Abstract Background Knowledge of normal muscle characteristics is crucial in planning rehabilitation programmes for injured athletes. There is a high incidence of ankle and anterior tibial symptoms in football players, however little is known about the effect of limb dominance on the anterior tibial muscle group (ATMG). The purpose of this study was to assess the effect of limb dominance and sports-specific activity on ATMG thickness in Gaelic footballers and non-football playing controls using ultrasound measurements, and to compare results from transverse and longitudinal scans. Methods Bilateral ultrasound scans were taken to assess the ATMG size in 10 Gaelic footballers and 10 sedentary controls (age range 18-25 yrs), using a previously published protocol. Both transverse and longitudinal images were taken. Muscle thickness measurements were carried out blind to group and side of dominance, using the Image-J programme. Results Muscle thickness on the dominant leg was significantly greater than the non-dominant leg in the footballers with a mean difference of 7.3%, while there was no significant dominance effect in the controls (p < 0.05). There was no significant difference between the measurements from transverse or longitudinal scans. Conclusions A significant dominance effect exists in ATMG size in this group of Gaelic footballers, likely attributable to the kicking action involved in the sport. This should be taken into account when rehabilitating footballers with anterior tibial pathology. Ultrasound is a reliable tool to measure ATMG thickness, and measurement may be taken in transverse or longitudinal section.

  6. Measurement of cervical range of motion pattern during cyclic neck movement by an ultrasound-based motion system.

    Science.gov (United States)

    Wang, Shwu-Fen; Teng, Chin-Chih; Lin, Kwan-Hwa

    2005-02-01

    Goniometers and radiographic imaging have been used to measure active or passive cervical range of motion (ROM) in asymptomatic adults. However, the ultrasound-based coordinate measuring system (CMS) can measure continuous neck motion in three dimensions. The aims of this investigation are to evaluate the reliability and validity of ultrasound-based CMS (Zebris, CMS 70P), and to compare the cervical ROM patterns of asymptomatic young and middle-aged adults during continuous neck motions in the three cardinal planes. The ROM reciprocal ratio was defined as the ratio of the ROM from neutral position in one direction versus that in the opposite direction at the same cardinal plane. This study demonstrated the high test-retest reliability and validity of CMS during cervical motion in Chinese participants. Middle-aged adults exhibit reduced ROM ratios in the sagittal and frontal planes. The advantages and limitations of the CMS measurement tool and the potential future applications are documented. The measurement of neck motion pattern by ultrasound-based CMS may provide information on the management of neck dysfunction during functional movements.

  7. Correlation of preoperative MRI and intraoperative 3D ultrasound to measure brain tissue shift

    Science.gov (United States)

    Gobbi, David G.; Lee, Belinda K. H.; Peters, Terence M.

    2001-05-01

    B-Mode ultrasound is often used during neurosurgery to provide intra-operative images of the brain though a craniotomy, but the use of 3D ultrasound during surgery is still in its infancy. We have developed a system that provides real-time freehand 3D ultrasound reconstruction at a reduced resolution. The reconstruction proceeds incrementally and the 3D image is overlayed, via a computer, on a pre-operative 3D MRI scan. This provides the operator with the necessary feedback to maintain a constant freehand sweep-rate, and also ensures that the sweep covers the desired anatomical volume. All of the ultrasound video frames are buffered, and a full-resolution, compounded reconstruction proceeds once the manual sweep is complete. We have also developed tools for manual tagging of homologous landmarks in the 3D MRI and 3D ultrasound volumes that use a piecewise cubic approximation of thin-plate spline interpolation to achieve interactive nonlinear registration and warping of the MRI volume to the ultrasound volume: Each time a homologous point-pair is identified by the use, the image of the warped MRI is updated on the computer screen after less than 0.5 s.

  8. Spectral energy measurements of simulated microemboli of various sizes using a diffraction grating ultrasound probe

    Science.gov (United States)

    Weiss, William J.; Ballakur, Sowmya G.; Tran, Hoang; Hazard, Sprague W.; Blebea, John

    2003-05-01

    This study characterizes the Doppler signal from simulated microemboli of various sizes in blood mimicking fluid using spectral energy parameters. The goal of this research is to detect microemboli as a non-invasive diagnostic tool, or intra-operatively as a surgical aid. A dual beam diffraction-grating ultrasound probe operating at 10 MHz (Model Echoflow BVM-1, EchoCath, Inc., Princeton, NJ) was used with a flow phantom. Microemboli were polystyrene microspheres in 200 to 1000 micron diameters, in concentrations of 0.1, 0.5, and 1.0 per ml. Average flow velocities were 25, 50, 75, and 100 cm/sec. The distribution of peak values of the power spectrum at 2.5 msec windows was plotted over 15 seconds. The means of the distributions corresponding to the microspheres and background fluid were averaged for the four velocity conditions. Embolic peak spectral power ranged from approximately 12 to 25 dB relative to the background. A detection method based on these measurements is currently being developed.

  9. Reliability of ultrasound texture measures of Biceps Brachialis and Gastrocnemius Lateralis muscles' images.

    Science.gov (United States)

    da Silva Pereira Júnior, Newton; da Matta, Thiago Torres; Alvarenga, André Victor; de Albuquerque Pereira, Wagner Coelho; de Oliveira, Liliam Fernandes

    2017-01-01

    Ultrasound (US) is an important tool for diagnosing of many musculoskeletal tissue conditions. Image texture analysis can be used to characterize this tissue. The complexity curve (CC) is a technique commonly used to characterize the number of grey-level transitions in an image. Variability and reliability of US texture measures in the muscle tissue are unavailable in the literature. The aim of this study was to determine the variability and reliability of five CC texture parameters from US images of healthy Biceps Brachialis and Gastrocnemius Lateralis (GL) muscles, with longitudinal and transversal orientations of the probe. Eight images per subject were obtained for 30 men in 2 days. Mean, standard deviation, coefficient of variation and intraclass correlation coefficient for the five parameters were calculated for regions of interest. Results showed that the variability was similar for both muscles and most of the parameters showed satisfactory reliability (r > 0·7) for the Biceps Brachialis with the transverse scan and for the GL with the longitudinal scan. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  10. Doppler ultrasound measurement of resistance index in the diagnosis of prostate cancer.

    Science.gov (United States)

    Huang, Wei; Cen, Son; Kang, Xin-Li; Wang, Wei Fu; Wang, Yang; Chen, Xiang

    2015-01-01

    Prostate cancer (PCa) remains the second leading cause of cancer diagnosis worldwide. Early diagnosis and treatment of PCa is critical since the long-term prognosis is excellent in patients with tumors confined to the prostate gland. The current meta-analysis investigates the diagnostic value of resistive index (RI) measurement using color Doppler ultrasound in patients with PCa. Electronic literature databases were exhaustively searched for relevant studies published prior to May 31, 2014. Nine studies met our predetermined inclusion criteria for the present meta-analysis. The methodologic quality of the selected studies was independently assessed by 2 reviewers based on Quality Assessment of Diagnostic Accuracy Studies tool. Our meta-analysis results showed that RI values were significantly higher in malignant prostate tissues compared to normal prostate tissues (standardized mean difference [SMD] 0.42, 95% confidence interval [CI] 0.12~0.73, p = 0.007) and benign prostate tissues (SMD 0.41, 95% CI 0.26~0.56, p<0.001). Subgroup analysis based on the diagnostic instruments used revealed that RI values were accurate in diagnosis of PCa when compared between malignant tissue vs normal tissue and malignant tissue vs benign tissue (all p<0.05). Taken together, our findings support the potential clinical applications of RI values in diagnosis of PCa.

  11. Frustration effects in spinel compound GeCo2O4 studied by ultrasound velocity measurements

    Science.gov (United States)

    Watanabe, Tadataka; Hara, Shigeo; Ikeda, Shin-Ichi

    2009-03-01

    Ultrasound velocity measurements of the cubic spinel GeCo2O4 in the single crystal have been performed for the investigations of shear and compression moduli. The shear moduli reveal the absence of Jahn-Teller activity despite the presence of the orbital degeneracy in the Co2+ ions. This Jahn-Teller inactivity indicates that the intersite orbital-orbital interaction is much stronger than the Jahn-Teller coupling. The compression moduli reveal that the dominant path of the exchange interactions for the antiferromagnetic transition lies in the [111] direction. This exchange-path anisotropy is consistent with the antiferromagnetic structure with the wave vector q parallel [111], suggesting the presence of bond frustration among several ferromagnetic and antiferromagientic interactions. In the JT-inactive condition, the bond frustration can be induced by geometrical orbital frustration of t2g-t2g interaction between the Co2+ ions which can be realized in the pyrochlore lattice of the high spin Co2+ with t2g -orbital degeneracy. In GeCo2O4, the tetragonal elongation below TN releases the orbital frustration by quenching the orbital degeneracy.

  12. Ultrasound Velocity Measurements in the Orbital-Degenerate Frustrated Spinel MgV2O4

    Science.gov (United States)

    Watanabe, Tadataka; Ishikawa, Takashi; Hara, Shigeo; Islam, A. T. M. Nazmul; Wheeler, Elisa M.; Lake, Bella

    2014-03-01

    Magnesium vanadate spinel MgV2O4 is a geometrically frustrated magnet with t2 g-orbital degeneracy of V3+ (3d2), which undergoes a cubic-to-tetragonal structural transition at Ts = 65 K and an antiferromagnetic (AF) transition at TN = 42 K. For MgV2O4, it is considered that the occurrence of t2 g-orbital order at Ts causes the release of frustration by the AF ordering at TN lower than Ts. We performed ultrasound velocity measurements in high-purity single crystal of MgV2O4. Temperature dependence of the tetragonal shear modulus (C11 -C12)/2 exhibits huge Curie-type softening in the cubic paramagnetic (PM) phase (T >Ts), which should be a precursor to the cubic-to-tetragonal lattice distortion at Ts. The trigonal shear modulus C44(T) exhibits softening with an upturn curvature in the cubic PM phase, indicating a coupling of the lattice to magnetic excitations. These softenings suggest the coexistence of the dynamical Jahn-Teller effect and the dynamical magnetic state in the cubic PM phase.

  13. Ultrasound Velocity Measurements in the Geometrically Frustrated Spinel MgCr2O4

    Science.gov (United States)

    Watanabe, Tadataka; Kousaka, Yusuke; Tomiyasu, Keisuke

    2012-02-01

    Magnesium chromite spinel MgCr2O4 is a geometrically frustrated magnet with the Néel temperature TN˜13 K, and the Weiss temperature θW= -390 K. Recent inelastic neutron scattering experiments provided a compelling evidence for the spin molecular ground states in not only the paramagnetic phase but also the antiferromagnetic phase. We performed ultrasound velocity measurements of MgCr2O4 in all the symmetrically independent elastic moduli of C11, (C11-C12)/2, and C44. Temperature dependence of all of these elastic moduli exhibits a remarkable softening in the paramagnetic phase. Taking into account the absence of orbital degrees of freedom in Cr^3+ (3d^3) in MgCr2O4, the spin degrees of freedom should play a significant role for the elastic softening. The most probable origin for the elastic softening in the paramagnetic phase is the strong coupling of the acoustic phonons to the molecular spin fluctuations.

  14. Comparison of Colour Duplex Ultrasound with Computed Tomography to Measure the Maximum Abdominal Aortic Aneurysmal Diameter

    Directory of Open Access Journals (Sweden)

    C. Gray

    2014-01-01

    Full Text Available Introduction. Maximum diameter of an abdominal aortic aneurysm (AAA is the main indication for surgery. This study compared colour duplex ultrasound (CDU and computed tomography (CT in assessing AAA diameter. Patients and Methods. Patients were included if they had both scans performed within 90 days. Pearson’s correlation coefficient, paired t-test, and limits of agreement (LOA were calculated for the whole group. Subgroup analysis of small (6.5 cm aneurysms was performed. A P value of <0.05 was considered statistically significant. Results. 389 patients were included, giving 130 pairs of tests for comparison. Excellent correlation was in the whole group (r = 0.95 and in the subgroups (r = 0.94; 0.69; 0.96, resp.. Small LOA between the two imaging modalities was found in all subgroups. Conclusion. Small aneurysms can be accurately measured using CDU. CDU is preferable for small AAAs, but cannot supplant CT for planning aortic intervention.

  15. Comparison of medical of volume measurement of the prostate by transrectal ultrasound: Experiment with jelly models

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jeong Yeon; Lee, Hak Jong; Kim, Sung Hyun [Samsung Seoul Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Seung Hyup [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2002-03-15

    To evaluate the accuracy of measuring the volume of the prostate using the prolate ellipsoid volume calculation method (antero-posterior (AP) diameter X length X width X {pi}6) when the antero-posterior diameter of the prostate was measured on midsagittal (sagittal volume) and axial plane (axial volume).The devil's tongue jelly was used for the creation of ultrasound model of the prostate (volume: 15-40 cc) by cutting and shaping the surface. The volume in 10 prostatic models and 30 patients was measured and calculated. First, the AP diameter and length of the prostate models in midsagittal plane, and the height and width of the models in axial plane were measured for 3 times. The volume was calculated in two ways, one using the AP diameter an midsagittal plane and the other using the AP diameter in axial plane. The true volume of the model was measured using mess cylinder. The calculated volume and true volume were compared, and the accuracy of two method of measuring the prostatic volume was evaluated by Friedman test. The intraobserver variation was evaluated by General Linear Model, Repeated Measure. The reproducibility was evaluated by Cronbach's {alpha}. In vivo study was also performed in 30 patients. The prostate volume was calculated in the same manner. These volume data were analyzed by statistical method, and the intraobeserver variation was evaluated. While there was a statistically significant difference between the sagittal and true volume of the models, there was no statistical significant difference between the axial and true volumes. There was no significant intraobserver variation between both methods. The reproducibility was high in both methods with Cronbach's {alpha} of 0.977 and 0.942. The sagittal volume was larger than the axial volume in 30 patients with a statistically significant difference. There was no significant intraobserver variation in both methods. The reproducibility was high in both methods Cronbach's {alpha

  16. Comparison of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeters in glaucoma patients.

    Science.gov (United States)

    Salim, Sarwat; Du, Haiming; Wan, Jim

    2015-07-01

    The purpose of this study was to compare the accuracy and reproducibility of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeter in glaucoma patients under treatment. Prospective study of 65 glaucoma patients. Central corneal thickness was measured by two ultrasound pachymeters: the hand-held, portable PachPen (Accutome, Lynwood, WA), and the desk-mounted PacScan 300 (Sonomed, Lake Success, NY). The mean ± SD central corneal thickness was 526.5 ± 44.8 µm and 530.0 ± 44.7 µm for the hand-held and desk-mounted pachymeters, respectively (p = 0.15). Linear regression analysis revealed a slope of 0.97 with Pearson correlation coefficient of 0.96. Bland-Altman analysis showed a mean difference of measurements by both pachymeters of 3.22 µm with two standard deviations = 9.51. Both instruments showed high intraobserver correlation: 0.972 for the hand-held pachymeter and 0.993 for the desk-mounted pachymeter. Central corneal thickness measurements were comparable with the use of hand-held and desk-mounted ultrasound units in glaucoma patients with good intraobserver reproducibility.

  17. Effect of genotype, sex and slaughter weight on veal Longissimus muscle area measured by ultrasound and planimeter

    Directory of Open Access Journals (Sweden)

    Zoran Luković

    2010-01-01

    Full Text Available The aim of this research was to determine effect of genotype (Holstein, Simmental and their crossbreeds, sex and slaughter weight groups (SW1=150-160kg and SW2=190-200kg on veal Longissimus muscle area (LMA. Between the12th and the13th rib, two ultrasound LMA (ULMA images were taken from each animal and carcass LMA (CLMA traced on transparent foil was measured by planimeter. For both measures, Simmental calves had larger LMA than Holstein (P<0.001 and crossbreeds (P<0.05. Male and female calves did not differ significantly in ULMA and CLMA. Calves of SW2 group had larger LMA (P<0.0001 than SW1 group. High correlation coefficient between ULMA and CLMA was determined in this research. Veal LMA was significantly affected by genotype and slaughter weight. According to high correlation coefficients, ultrasound can be useful in estimating carcass traits of cattle at early age.

  18. Joseph F. Keithley Award For Advances in Measurement Science: Resonant Ultrasound Spectroscopy: An Odyssey in Measurement Science

    Science.gov (United States)

    Migliori, Albert

    Perhaps the speeds of sound, or, equivalently, the elastic moduli are some of the most fundamental attributes of a solid, connecting to fundamental physics, metallurgy, non-destructive testing, and more. Unlike most of the quantities used to characterize condensed matter, the elastic moduli are fourth-rank tensors containing a wealth of detail, directional information, and consistency constraints that provide some of the most revealing probes of solids. We describe here the current state of the art in one method, Resonant Ultrasound Spectroscopy, where the mechanical resonances of a specimen of regular shape (easy to measure) are analyzed (difficult computational problem) to obtain the full elastic tensor. With modern advances in electronics and analysis, fractions of a part per million changes in elastic moduli are detectable providing new and important insight into grand challenges in condensed matter physics. This work was supported as part of the Materials Science of Actinides, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0001089.

  19. 产科弥散性血管内凝血的急救措施及效果分析%Obstetric disseminated intravascular coagulation aid measures and effect analysis

    Institute of Scientific and Technical Information of China (English)

    江红

    2014-01-01

    目的:探讨产科弥散性血管内凝血(DIC)的急救措施并对其治疗效果进行分析,以提高本院产科对DIC的认识。方法选取本院产科2010年5月至2012年5月收治的49例DIC患者,对其病历及临床资料进行回顾性分析。结果通过分析发现产科DIC发病原因主要包括胎盘早剥、前置胎盘、胎儿宫内死亡和羊水栓塞等,对患者采取适当的急救措施后其各项凝血指标均显著优于急救前(P<0.01)。急救后,无1例患者死亡,其中10例患者由于急救后不能有效止血改行子宫切除术,46例围生儿得以存活,3例围生儿宫内死亡。结论临床治疗产科DIC患者时,首先必须找出其发病原因,采取适当的急救措施,阻止凝血过程,维持微循环平衡和畅通,从而达到降低死亡率和提高患者生存质量的目的。%Objective To evaluate the obstetric disseminated intravascular coagulation (DIC) first aid measures and its clinical outcomes were analyzed in order to improve our hospital obstetric DIC to unders-tanding. Method Obstetric hospital in May 2010 to May 2012 were treated 49 cases of patients with DIC, their medical history and clinical data were retrospectively analyzed. Result The analysis showed that the main causes of DIC placental abruption, and pre-implantation and fetal death and amniotic lfuid embolism, etc., for patients to take appropriate emergency measures of its coagulation parameters were signiifcantly better than before resuscitation (P<0.01). After ifrst aid, no patients died, including 10 cases of bleeding because aid can not be effectively diverted after hysterectomy, 46 cases of perinatal child survived, only three cases of perinatal child fetal death. Conclusion Clinically in the treatment of DIC patients, you must ifrst identify its causes, the use of appropriate emergency measures to prevent the clotting process, to maintain balance and smooth micro-circulation, which can

  20. A step towards measuring the fetal head circumference with the use of obstetric ultrasound in a low resource setting

    Science.gov (United States)

    van den Heuvel, Thomas L. A.; Petros, Hezkiel; Santini, Stefano; de Korte, Chris L.; van Ginneken, Bram

    2017-03-01

    Worldwide, 99% of all maternal deaths occur in low-resource countries. Ultrasound imaging can be used to detect maternal risk factors, but requires a well-trained sonographer to obtain the biometric parameters of the fetus. One of the most important biometric parameters is the fetal Head Circumference (HC). The HC can be used to estimate the Gestational Age (GA) and assess the growth of the fetus. In this paper we propose a method to estimate the fetal HC with the use of the Obstetric Sweep Protocol (OSP). With the OSP the abdomen of pregnant women is imaged with the use of sweeps. These sweeps can be taught to somebody without any prior knowledge of ultrasound within a day. Both the OSP and the standard two-dimensional ultrasound image for HC assessment were acquired by an experienced gynecologist from fifty pregnant women in St. Luke's Hospital in Wolisso, Ethiopia. The reference HC from the standard two-dimensional ultrasound image was compared to both the manually measured HC and the automatically measured HC from the OSP data. The median difference between the estimated GA from the manual measured HC using the OSP and the reference standard was -1.1 days (Median Absolute Deviation (MAD) 7.7 days). The median difference between the estimated GA from the automatically measured HC using the OSP and the reference standard was -6.2 days (MAD 8.6 days). Therefore, it can be concluded that it is possible to estimate the fetal GA with simple obstetric sweeps with a deviation of only one week.

  1. Predicting outcome in very low birthweight infants using an objective measure of illness severity and cranial ultrasound scanning

    OpenAIRE

    Fowlie, P; Tarnow-Mordi, W; Gould, C.; Strang, D

    1998-01-01

    AIM—To investigate the feasibility of developing an objective tool for predicting death and severe disability using routinely available data, including an objective measure of illness severity, in very low birthweight babies.
METHOD—A cohort study of 297 premature babies surviving the first three days of life was made. Predictive variables considered included birthweight, gestation, 3 day cranial ultrasound appearances and 3 day CRIB (clinical risk index for babies) score. ...

  2. Imaging of In-Vivo Pressure using Ultrasound

    DEFF Research Database (Denmark)

    Olesen, Jacob Bjerring

    . The developed technique showed a standard deviation and bias across constricted flow domains of 9 % and 8 %, respectively. Finally, the first in-vivo examples of deriving pressure changes from 2-D vector velocity ultrasound data is presented. Based on the presented results it is concluded that non......The main purpose of this PhD project was to develop an ultrasonic method capable of determining intravascular pressure changes non-invasively. Measuring pressure variations is used clinically as a diagnostic marker for the physiological state of a cardiovascular region. Current clinical procedures...... for assessing pressure changes are by means of invasive devices such as pressure sensing catheters. Such devices suffer severe limitations as they are invasive and require the use of ionizing radiation for guidance and positioning. To overcome the concerns related to the use of invasive pressure catheters...

  3. Epidemiological survey of the feasibility of broadband ultrasound attenuation measured using calcaneal quantitative ultrasound to predict the incidence of falls in the middle aged and elderly

    Science.gov (United States)

    Ou, Ling-Chun; Chang, Yin-Fan; Chang, Chin-Sung; Chiu, Ching-Ju; Chao, Ting-Hsing; Sun, Zih-Jie; Lin, Ruey-Mo; Wu, Chih-Hsing

    2017-01-01

    Objectives We investigated whether calcaneal quantitative ultrasound (QUS-C) is a feasible tool for predicting the incidence of falls. Design Prospective epidemiological cohort study. Setting Community-dwelling people sampled in central western Taiwan. Participants A cohort of community-dwelling people who were ≥40 years old (men: 524; women: 676) in 2009–2010. Follow-up questionnaires were completed by 186 men and 257 women in 2012. Methods Structured questionnaires and broadband ultrasound attenuation (BUA) data were obtained in 2009–2010 using QUS-C, and follow-up surveys were done in a telephone interview in 2012. Using a binary logistic regression model, the risk factors associated with a new fall during follow-up were analysed with all significant variables from the bivariate comparisons and theoretically important variables. Primary outcome measures The incidence of falls was determined when the first new fall occurred during the follow-up period. The mean follow-up time was 2.83 years. Results The total incidence of falls was 28.0 per 1000 person-years for the ≥40 year old group (all participants), 23.3 per 1000 person-years for the 40–70 year old group, and 45.6 per 1000 person-years for the ≥70 year old group. Using multiple logistic regression models, the independent factors were current smoking, living alone, psychiatric drug usage and lower BUA (OR 0.93; 95% CI 0.88 to 0.99, p<0.05) in the ≥70 year old group. Conclusions The incidence of falls was highest in the ≥70 year old group. Using QUS-C-derived BUA is feasible for predicting the incidence of falls in community-dwelling elderly people aged ≥70 years. PMID:28069623

  4. Measuring of Gastric Emptying in Egyptian Pediatric Patients with Portal Hypertension by Using Real-time Ultrasound

    Science.gov (United States)

    Fahmy, Mona E.; Osman, Mahmoud A.; Mahmoud, Rehab A.; Mohamed, Lamiaa K.; Seif-elnasr, Khaled I.; Eskander, Ayman E.

    2012-01-01

    Background/Aim: Among the various methods for evaluating gastric emptying, the real-time ultrasound is safe, does not require intubation, or rely on either radiologic or radionuclide technique. The aim of our work was to measure the gastric emptying in pediatric patients with portal hypertension by using the real-time ultrasound. Patients and Methods: Forty patients with portal hypertension with mean age 7 ± 2.8 years and 20 healthy children as a control group underwent gastric emptying study by using real-time ultrasound. The cross-sectional area of the gastric antrum was measured in the fasting state and then each subject was allowed to drink tap water then calculated by using formula area (π longitudinal × anteroposterior diameter/4). The intragastric volume was assumed to be directly proportional to the cross-sectional area of the antrum. Results: The mean gastric emptying half-time volume was significantly delayed in portal hypertension patients (40 ± 6.8 min) compared with the control subjects (27.1 ± 3.6) min (P<0.05). Patients with extrahepatic portal vein obstruction had significant delayed gastric emptying in comparison to patients with portal hypertension due to other etiologies (36.14 ± 4.9 vs 44.41 ± 6.04 min; P<0.01). Conclusion: Ultrasound is a noninvasive and a reliable method for measuring gastric emptying in pediatric patients. Gastric emptying was significantly delayed in patients with portal hypertension. Etiology of portal hypertension may influence gastric emptying time in patients with chronic liver disease. PMID:22249091

  5. Comparison of the POP-Q examination, transvaginal ultrasound, and direct anatomic measurement of cervical length.

    Science.gov (United States)

    Dancz, Christina E; Werth, Lisa; Sun, Vanessa; Lee, Sandy; Walker, Daphne; Özel, Begüm

    2014-04-01

    Our objective was to determine the relationship between the Pelvic Organ Prolapse Quantification (POP-Q) examination for determining cervical length (CL) and CL at hysterectomy. Secondary objectives were to define cervical elongation using both measures in a urogynecologic population, determine the relationship between POP-Q estimate and CL on ultrasound (US) and examine the interobserver reliability of each mode of measurement. This was a prospective cohort study of women scheduled for hysterectomy at the Los Angeles County + University of Southern California (LAC + USC) medical center. CLs were measured by POP-Q and at the time of hysterectomy. Transvaginal US CLs were determined when available. Exam CL (eCL) was compared with anatomic (aCL) and US (uCL) CL. Repeat measures of eCL, uCL, and aCL were all compared for interobserver reliability. The study enrolled 151 women. Median eCL was 3.0 cm (0.5-9.0) (n = 149); average uCL was 2.3 cm ± 0.7 (n = 108), average aCL 2.8 cm ± 1.1 (n = 87); eCL correlated fairly with aCL (r = 0.3, p = 0.005, n = 88) but poorly with uCL (r = -0.13, p = 0.18, n = 105); uCL correlated poorly with aCL (r = 0.19, p = 0.14, n = 64). Interobserver reliability for eCL and aCL were good to excellent (eCL α=0.881; aCL α=0.889) but for uCL adequate (α=0.699). The 97.5 percentile cutoff for aCL was 5.0 cm and for eCL 8.0 cm. The POP-Q examination estimate of CL correlates fairly with aCL at the time of hysterectomy; uCL does not appear to correlate with aCL or eCL. Cervical elongation may be defined as an anatomic length of 5.0 cm or a POP-Q estimate of 8.0 cm.

  6. A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force.

    Science.gov (United States)

    Yoon, Sangpil; Aglyamov, Salavat; Karpiouk, Andrei; Emelianov, Stanislav

    2012-08-07

    A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young's moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young's moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed.

  7. The investigation of ultrasound technology to measure breast muscle depth as a correlated trait to breast meat yield in turkey (Meleagris gallopavo).

    Science.gov (United States)

    Case, L A; Wood, B J; Miller, S P

    2012-10-01

    Ultrasound measurements of muscle depth were analyzed to determine if these traits could be used to increase the rate of genetic gain in breast meat yield (BMY). Two measurements of breast depth, one taken horizontally across both breast lobes and one parallel to the keel, were captured using ultrasound. Heritabilities of muscle depth traits ranged from 0.35 to 0.70. These values were greater than heritabilities of conformation scores, which ranged from 0.25 to 0.47 within sex and line. The ultrasound traits also showed strong genetic correlations to BMY, ranging from 0.43 to 0.75, indicating that selection, using ultrasound depth as a correlated information source, could result in improved BMY. Including each ultrasound trait in a linear regression model predicting BMY increased the proportion of variation explained by the models by 0.08 to 0.17, relative to using conformation score as the only in vivo estimate. Based on results from a simulated turkey breeding program with selection pressure only on BMY, the ultrasound measures could increase the accuracy of a selection index for BMY by 0.02 to 0.16. As a result, ultrasound technology has the potential to improve the rate of genetic gain in BMY in a breeding program.

  8. The thickness of the retrobulbar portion of the optic nerve in Graves ophthalmopathy measured by ultrasound

    Directory of Open Access Journals (Sweden)

    Stefanović Ivan

    2009-01-01

    Full Text Available Introduction. The clinical diagnostic of Graves ophthalmopathy is based on the association of ocular signs and the disease of the thyroid gland. The evolution of the disease involves the development of eye globe protrusion, extraocular muscle thickening pressuring the optic nerve, which can result in its thickness. Objective. The aim of the paper is to find whether the retrobulbar optic nerve thickened and if there was a correlation between its possible thickening and the thickness of the muscles in Graves ophthalmopathy. We also wished to test the theory of compressive aetiology of such thickening using a 30-degree test. Methods. We examined 28 patients with Graves ophthalmopathy. The thickness of the retrobulbar optic nerve was measured by ultrasound on a B-scan using the Schraeder's method and by the largest thickness of the internal muscle. Results. The thickness of the retrobulbar portion of the optic nerve in the 52 analyzed eyes with signs of the disease ranged between 3.24 mm to 6.30 mm, with median of 5.13 mm, indicating that the majority of the patients had optic nerve thickening rating at this value. Forty-eight eyes had a marked retrobulbar optic nerve thickening, with the thickening over 4 mm, while in 4 eyes with signs of Graves ophthalmopathy the thickness of the optic nerve was within normal limits. We detected that 92.3% of the patients with muscular thickening also had a directly proportional thickening of the retrobulbar optic nerve. By using the 30-degree test we confirmed the diagnosis of compressive neuropathy. Conclusion. Patients with Graves ophthalmopathy and thickened muscles, also have a thickening of the retrobulbar optic nerve; the rate of the thickness directly depends on the degree of the muscular thickness. The word is of compressive neuropathy, i.e. the thickness of the optic nerve is the result of subarachnoid fluid stasis caused by the compression on the optic nerve.

  9. Membrane design of an all-optical ultrasound receiver

    NARCIS (Netherlands)

    Leinders, S.M.; Dongen, K.W.A. van; Jong, N. de; Verweij, M.D.; Westerveld, W.J.; Urbach, H.P.; Neer, P.L.M.J. van; Pozo Torres, J.M.

    2013-01-01

    Ultrasound sensors such as piezoelectric transducers and CMUTs are successfully used for medical imaging. However, especially wiring of individual elements is difficult in the fabrication of small piezoelectric arrays, used in, e.g. the field of intravascular imaging. As an alternative, we designed

  10. High frequency measurements of the contact between machine elements using ultrasound

    Science.gov (United States)

    Quinn, A. M.; Drinkwater, B. W.; Dwyer-Joyce, R. S.

    2002-05-01

    This paper describes a study of the experimental interaction of ultrasound with real rough surfaces, and the modeled interaction of ultrasound with an infinite array of holes, using Finite Element Analysis, in an attempt to discover the limit of applicability of the quasi-static spring model. The relationship between reflected amplitude of the scattered wave, and the size of the hole acting as reflector, was found and used to create a finite element independent scatter model. This was compared to the quasi-static model and it was found that the two models diverge at a ka value of approximately 0.6.

  11. Introducing intravascular microdialysis for continuous lactate monitoring in patients undergoing cardiac surgery : a prospective observational study

    NARCIS (Netherlands)

    Schierenbeck, Fanny; Nijsten, Maarten W. N.; Franco-Cereceda, Anders; Liska, Jan

    2014-01-01

    Introduction: Lactate is a marker of hypoperfusion and may be used for risk assessment in critically ill patients. Although evidence suggests that repeated lactate measurements are of clinical interest, how and when lactate should be analyzed is controversial. Intravascular microdialysis provides a

  12. Introducing intravascular microdialysis for continuous lactate monitoring in patients undergoing cardiac surgery : a prospective observational study

    NARCIS (Netherlands)

    Schierenbeck, Fanny; Nijsten, Maarten W. N.; Franco-Cereceda, Anders; Liska, Jan

    2014-01-01

    Introduction: Lactate is a marker of hypoperfusion and may be used for risk assessment in critically ill patients. Although evidence suggests that repeated lactate measurements are of clinical interest, how and when lactate should be analyzed is controversial. Intravascular microdialysis provides a

  13. 血管内超声评价国产瑞舒伐他汀对冠状动脉轻中度狭窄病变的影响%Effects of domestic rosuvastatin on coronary plaque in patients with mild-to-moderate coronary artery stenosis as evaluated by virtual histology-intravascular ultrasound

    Institute of Scientific and Technical Information of China (English)

    杨海波; 赵晓燕; 赵荫涛; 张金盈; 李凌

    2012-01-01

    目的 应用虚拟组织学-血管内超声(VH-IVUS)评价国产瑞舒伐他汀对急性冠脉综合征患者冠状动脉轻中度狭窄病变斑块进展及成分的影响.方法 选择经冠状动脉造影(CAG)和VHIVUS检查无需介入治疗的冠脉轻中度狭窄病变患者83例,分为试验组42例和对照组41例,试验组给予国产瑞舒伐他汀(瑞旨10 mg,每晚1次),对照组给予进口瑞舒伐他汀(可定10 mg,每晚1次),治疗6个月后复查血脂、CAG及VH-IVUS,比较两组间血脂变化、定量冠脉造影分析靶病变处直径狭窄(DS)变化,VH-IVUS分析靶病变处斑块负荷、最小管腔面积(MLA)和斑块成分变化.结果 瑞舒伐他汀干预6个月后,VH-IVUS分析显示,两组患者斑块坏死核心比例比治疗前明显减少(试验组:14.8%±7.0%比22.6%±7.5%,P<0.05,对照组:14.9%±7.1%比23.1% ±7.7%,P<0.05)、纤维组织比例明显增加(试验组:51.5%±9.9%比44.5%±9.7%,P< 0.05,对照组:51.4%±10.1%比44.3%±9.8%,P<0.05),两组患者血脂水平明显改善(P<0.05),而DS、斑块负荷、MLA、纤维脂质组织比例、钙化组织比例无明显变化(P>0.05).结论 国产瑞舒伐他汀治疗冠脉轻中度狭窄病变可稳定斑块,并延缓斑块进一步发展.%Objective To evaluate the effects of domestic rosuvastatin tablets on coronary plaque in the patients with mild-to-moderate coronary artery stenosis through virtual histology-intravascular ultrasound (VH-IVUS).Methods Eighty-three patients with mild-to-moderate coronary artery stenosis of acute coronary syndrome( ACS)were enrolled and randomized into test group (domestic rosuvastatin,10 mg/day,n =42) or control group ( CRESTOR,10 mg/day,n =41 ).The serum lipid levels,diameter stenosis (DS)on quantitative coronary angiography (QCA),MLA (minimal lumen area),plaque burden and component of target lesion on VH-IVUS were evaluated at baseline and at 6-month follow-up.Results After 6 months,the levels of

  14. Combined use of optical coherence tomography and intravascular ultrasound during percutaneous coronary intervention in patients with coronary artery disease%光学相干断层成像和血管内超声在冠状动脉介入手术中的应用

    Institute of Scientific and Technical Information of China (English)

    侯静波; 孟令波; 景慎鸿; 韩志刚; 于淮; 于波

    2008-01-01

    目的 应用光学相干断层成像(OCT)及血管内超声(IVUS)检测技术评价冠状动脉内粥样硬化斑块的稳定性,并指导支架置入,检测血管对置入支架后即刻和中远期的反应.方法 选择2008年2-7月间的27例患者,进行冠状动脉造影、OCT及IVUS检查,共检查了30支血管,其中8处为药物支架植入术后血管,并对19处病变进行了支架置入.结果 除外支架置入的8例(置入6个月~4年)外,其余22例病变行OCT及IVUS检查,发现稳定性斑块5例,不稳定斑块17例,其中OCT检出内膜小撕裂4例(IVUS未检出,P>0.05),冠状动脉撕裂伴夹层病变5例(IVUS检出1例,P>0.05),血栓形成5例(IVUS检出1例,P>0.05),偏心斑块伴薄纤维帽12例(IVUS检出2例,P<0.01).8例曾经进行支架治疗的患者,造影、OCT和IVUS发现2例再狭窄;OCT显示支架内膜覆盖良好,IVUS小能精确看到内膜;OCT检测出1例患者有支架后瘤样扩张.对17例不稳定性斑块及2例支架再狭窄病例行支架置入术,术后支架膨胀不良发生率26.0%,OCT及IVUS检出率相同;支架贴壁不良发生率63.2%,IVUS榆出率低于OCT(10.5%比63.2%,P<0.01);支架近远端撕裂10.5%,IVUS均不能检出;内膜脱垂发生率52.6%,IVUS检出率低于OCT(10.5%比52.6%,P<0.05).结论 OCT与IVUS相比,在不稳定性斑块检测准确度方面明显优于IVUS,更能精确指导冠状动脉支架置人.IVUS在操作简便性及反映斑块负荷方面要优于OCT.%Objective To evaluate the value of combined optical coherence tomography (OCT) and intravascular ultrasound (IVUS) examinations in detecting coronary artery plaque during percutaneous transluminal coronary intervention (PCI).Methods CICT and IVUS examinations were performed on 30 diseased coronary vessels from 27 patients underwent PCI from Feb.2008 to Jul.2008.Results Seventeen vulnerable plaques (4 intima tearing which were not detected by IVUS),5 plaque rupture (1 out of 5 was detected by IVUS),5 thrombus

  15. Reproducibility of 3-Dimensional Ultrasound Measurements of Placental Volume at Gestational Ages 11 - 14 Weeks

    DEFF Research Database (Denmark)

    Larsen, M L; Naver, K V; Kjaer, M M;

    2015-01-01

    OBJECTIVE: To evaluate the reproducibility of placental volume using three-dimensional ultrasound. METHODS: The VOCAL (Virtual Organ Computer-aided AnaLysis) technique involves rotating an image of an object along an established axis using predefined angles. This provides a number of sections to ...

  16. Reproducibility of 3-Dimensional Ultrasound Measurements of Placental Volume at Gestational Ages 11 - 14 Weeks

    DEFF Research Database (Denmark)

    Larsen, M L; Naver, K V; Kjaer, M M

    2015-01-01

    OBJECTIVE: To evaluate the reproducibility of placental volume using three-dimensional ultrasound. METHODS: The VOCAL (Virtual Organ Computer-aided AnaLysis) technique involves rotating an image of an object along an established axis using predefined angles. This provides a number of sections to ...

  17. Visualizing and Measuring the Temperature Field Produced by Medical Diagnostic Ultrasound Using Thermography

    Science.gov (United States)

    Vachutka, J.; Grec, P.; Mornstein, V.; Caruana, C. J.

    2008-01-01

    The heating of tissues by diagnostic ultrasound can pose a significant hazard particularly in the imaging of the unborn child. The demonstration of the temperature field in tissue is therefore an important objective in the teaching of biomedical physics to healthcare professionals. The temperature field in a soft tissue model was made visible and…

  18. First measurements on a novel type of optical micro-machined ultrasound transducer (OMUT)

    NARCIS (Netherlands)

    Leinders, S.M.; Dongen, K.W.A. van; Jong, N. de; Verweij, M.D.; Westerveld, W.J.; Urbach, H.P.; Neer, P.L.M.J. van; Pozo Torres, J.M.

    2014-01-01

    Several types of ultrasound sensors have been developed and are used in the field of medical imaging. Conventional transducers are made of piezo-electric material and show good practical performance. However, when the piezo-electric elements need to be small (below 100 μm × 100 μm), these transducer

  19. First measurements on a novel type of optical micro-machined ultrasound transducer (OMUT)

    NARCIS (Netherlands)

    Leinders, S.M.; Dongen, K.W.A. van; Jong, N. de; Verweij, M.D.; Westerveld, W.J.; Urbach, H.P.; Neer, P.L.M.J. van; Pozo Torres, J.M.

    2014-01-01

    Several types of ultrasound sensors have been developed and are used in the field of medical imaging. Conventional transducers are made of piezo-electric material and show good practical performance. However, when the piezo-electric elements need to be small (below 100 μm × 100 μm), these transducer

  20. Doppler Ultrasound: What Is It Used for?

    Science.gov (United States)

    ... in your neck (carotid artery stenosis) A Doppler ultrasound can estimate how fast blood flows by measuring the rate of change in its pitch (frequency). During a Doppler ultrasound, a technician trained in ultrasound imaging (sonographer) presses ...

  1. Techniques for Intravascular Foreign Body Retrieval

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, Joe B.; Uberoi, Raman, E-mail: raman.uberoi@orh.nhs.uk [Oxford University Hospitals (United Kingdom)

    2013-08-01

    As endovascular therapies increase in frequency, the incidence of lost or embolized foreign bodies is increasing. The presence of an intravascular foreign body (IFB) is well recognized to have the potential to cause serious complications. IFB can embolize and impact critical sites such as the heart, with subsequent significant morbidity or mortality. Intravascular foreign bodies most commonly result from embolized central line fragments, but they can originate from many sources, both iatrogenic and noniatrogenic. The percutaneous approach in removing an IFB is widely perceived as the best way to retrieve endovascular foreign bodies. This minimally invasive approach has a high success rate with a low associated morbidity, and it avoids the complications related to open surgical approaches. We examined the characteristics, causes, and incidence of endovascular embolizations and reviewed the various described techniques that have been used to facilitate subsequent explantation of such materials.

  2. Influence of coupling substances in the measurement of ultrasound velocity in stone materials

    Science.gov (United States)

    Giuzio, Beatrice; Alvarez de Buergo, Monica; Fort, Rafael; Masini, Nicola

    2015-04-01

    Ultrasonic (US) testing is widely applied in many fields (i.e. aviation, petrochemical, power engineering, construction and metallurgical industries). In the field of built cultural heritage and science conservation, US testing can provide the quality of the historic building materials (physic-mechanical properties), their heterogeneity/homogeinity and anisotropy, in terms of materials characterization, but also how deterioration processes can affect their quality (either after natural decay or simulation ageing tests in the laboratory). Moreover, US testing is a useful technique in evaluating the effectiveness of conservation and restoration techniques such as assessing the compatibility among original and restoration materials, identification of original quarries, and the success or not in the increase of a material cohesion when applying consolidating products. In order to obtain precise, real and reliable measurements, coupling substances between the material surface and the ultrasonic sensors are frequently used, to provide a proper contact between the transducer and the material, to assure the perfect transmission of the ultrasonic wave. Various coupling agents can be applied for this purpose. According to Wesolowski (2012), the choice of the coupling agent significantly affects the measurement of propagation velocity in material samples and, as a consequence, the US test results. In this paper, the effect of six coupling agents (medical gel used for ultrasonography, gel + parafilm, plasticine, honey, glicerine and a plastic material provided for ultrasound measurement by Panametrics) on ultrasonic measurements conducted on specific building materials is investigated on two different types of building stones (granite and dolostone from the area of Madrid, traditionally used in the construction of the built heritage, 4 stone specimens for each rock variety, 20 x 6 x 8 cm). Direct and indirect modes measuring were performed, the first one with the transducers

  3. [Disseminated intravascular coagulation in solid tumours].

    Science.gov (United States)

    Ferrand, François Régis; Garcia-Hejl, Carine; Moussaid, Yassine; Schernberg, Antoine; Bidard, François-Clément; Pavic, Michel; Khenifer, Safia; Stoclin, Annabelle

    2014-06-01

    Disseminated intravascular coagulation (DIC) is a complex abnormality of hemostasis with dramatic consequences and long described as associated with tumors. Yet the diagnosis and management of paraneoplastic DIC are poorly defined. The purpose of this paper is to review DIC associated with solid tumors, at the pathophysiological and therapeutic levels in particular. We also report data from a recent retrospective series of patients with DIC in the context of a solid tumor, to illustrate the epidemiological, clinical and prognostic.

  4. Temporary intravascular shunts for peripheral vascular trauma.

    Directory of Open Access Journals (Sweden)

    Husain A

    1992-04-01

    Full Text Available Polyvinylchloride (PVC disposable endotracheal suction catheters were successfully used as temporary intravascular shunts in 5 patients of popliteal artery trauma. These simple shunts should be used routinely in such conditions to immediately re-establish blood supply to the ischaemic limb particularly in patients of polytrauma where systemic anticoagulation is contraindicated. This avoids the inherent delay prior to vascular repair and reduces the incidence of irreversible ischemia.

  5. Measurement of Cervical Length Changes During Normal Pregnancy by Endovaginal Ultrasound Device

    Directory of Open Access Journals (Sweden)

    Morteza Tahmasebi

    2009-01-01

    Full Text Available "nIntroduction: Cervical disability for preservation of pregnancy is called cervical insufficiency. On time diagnosis of cervical insufficiency is important for preventing actions. Endovaginal sonography is one of the most important methods. The importance of cervical length measurement is to diagnose cervical insufficiency and to decide on cerclage. In this study, we evaluated endovaginal sonography assessment of the cervical length changes during a normal pregnancy. "nMaterials and Methods: In a prospective cross-sectional study, endovaginal sonography was performed to measure the cervical length and the mean of the cervical lengths on 150 pregnant women (50 in every trimester. They were  compared together by the one way Anova test. The patients were followed until labor. Twin pregnancies and cases with a history of uterus curettage, cervical anomaly, preterm labor and cerclage were eliminated from the study. "nResults: The mean of the cervical length in the first, second and third trimesters of pregnancy were 39 mm, 40.7mm and 39.3mm, respectively. Also, the minimum and the maximum length of the cervix in the same trimesters were: 28 and 56 mm, 26 and 52 mm, 27 and 52mm, respectively. It was noted to history of normal vaginal delivery (NVD, past cesarean and the first pregnancy. The minimum cervical length was seen in the first pregnancy and the maximum cervical length was seen in past NVD. Between the means of cervical length in three trimesters of pregnancy there was no significant statistical difference, but there was a significant statistical difference between the mean cervical length and the maternal parity. On the other hand between maternal age and cervical length there was no significant statistical difference. "nConclusion: By comparing the mean cervical length in three trimesters, 39 mm was accepted for mean cervical length in different trimesters. There was a significant statistical correlation between the mean cervical lengths

  6. Diagnosis and treatment of disseminated intravascular coagulation.

    Science.gov (United States)

    Levi, M

    2014-06-01

    Disseminated intravascular coagulation (DIC) is a condition in which systemic activation of coagulation without a specific localization occurs, resulting in extensive formation of intravascular fibrin, particularly in small and midsize vessels. Disseminated intravascular coagulation may lead to several altered coagulation parameters, including a low platelet count, abnormal global clotting assays, low levels of physiological anticoagulant proteases, or increased fibrin degradation products. Also, more complex assays for activation of coagulation factors or pathways may indicate involvement of these molecules in DIC. None of these tests alone, however, can accurately ascertain or rebuff a diagnosis of DIC. Nonetheless, a combination of readily available routine assays may be instrumental in establishing a diagnosis of DIC and can also be useful to point to a subset of patients with DIC that may need definite, often costly, interventions in the hemostatic system. Current insights on relevant etiological pathways that may contribute to the occurrence of DIC have led to innovative therapeutic and adjunctive approaches to patient with DIC. Management options directed at the amelioration of hemostatic activation may tentatively be indicated and were found to be advantageous in experimental and clinical investigations. These treatments encompass elimination of tissue factor-mediated thrombin generation or restitution of normal anticoagulant function.

  7. An Implantable Intravascular Pressure Sensor for a Ventricular Assist Device

    Directory of Open Access Journals (Sweden)

    Luigi Brancato

    2016-08-01

    Full Text Available The aim of this study is to investigate the intravascular application of a micro-electro-mechanical system (MEMS pressure sensor to directly measure the hemodynamic characteristics of a ventricular assist device (VAD. A bio- and hemo-compatible packaging strategy is implemented, based on a ceramic thick film process. A commercial sub-millimeter piezoresistive sensor is attached to an alumina substrate, and a double coating of polydimethylsiloxane (PDMS and parylene-C is applied. The final size of the packaged device is 2.6 mm by 3.6 mm by 1.8 mm. A prototype electronic circuit for conditioning and read-out of the pressure signal is developed, satisfying the VAD-specific requirements of low power consumption (less than 14.5 mW in continuous mode and small form factor. The packaged sensor has been submitted to extensive in vitro tests. The device displayed a temperature-independent sensitivity (12 μ V/V/mmHg and good in vitro stability when exposed to the continuous flow of saline solution (less than 0.05 mmHg/day drift after 50 h. During in vivo validation, the transducer has been successfully used to record the arterial pressure waveform of a female sheep. A small, intravascular sensor to continuously register the blood pressure at the inflow and the outflow of a VAD is developed and successfully validated in vivo.

  8. High-resolution intravascular magnetic resonance quantification of atherosclerotic plaque at 3T

    Directory of Open Access Journals (Sweden)

    Qian Di

    2012-03-01

    Full Text Available Abstract Background The thickness of fibrous caps (FCT of atherosclerotic lesions is a critical factor affecting plaque vulnerability to rupture. This study tests whether 3 Tesla high-resolution intravascular cardiovascular magnetic resonance (CMR employing tiny loopless detectors can identify lesions and accurately measure FCT in human arterial specimens, and whether such an approach is feasible in vivo using animal models. Methods Receive-only 2.2 mm and 0.8 mm diameter intravascular loopless CMR detectors were fabricated for a clinical 3 Tesla MR scanner, and the absolute signal-to-noise ratio determined. The detectors were applied in a two-step protocol comprised of CMR angiography to identify atherosclerotic lesions, followed by high-resolution CMR to characterize FCT, lesion size, and/or vessel wall thickness. The protocol was applied in fresh human iliac and carotid artery specimens in a human-equivalent saline bath. Mean FCT measured by 80 μm intravascular CMR was compared with histology of the same sections. In vivo studies compared aortic wall thickness and plaque size in healthy and hyperlipidemic rabbit models, with post-mortem histology. Results Histology confirmed plaques in human specimens, with calcifications appearing as signal voids. Mean FCT agreed with histological measurements within 13% on average (correlation coefficient, R = 0.98; Bland-Altman analysis, -1.3 ± 68.9 μm. In vivo aortic wall and plaque size measured by 80 μm intravascular CMR agreed with histology. Conclusion Intravascular 3T CMR with loopless detectors can both locate atherosclerotic lesions, and accurately measure FCT at high-resolution in a strategy that appears feasible in vivo. The approach shows promise for quantifying vulnerable plaque for evaluating experimental therapies.

  9. Precision of Corneal Thickness Measurements Obtained Using the Scheimpflug-Placido Imaging and Agreement with Ultrasound Pachymetry

    Directory of Open Access Journals (Sweden)

    Jinhai Huang

    2015-01-01

    Full Text Available Purpose. To assess the reliability and comparability of measuring central corneal thickness (CCT and thinnest corneal thickness (TCT using a new Scheimpflug-Placido analyzer (TMS-5, Japan and ultrasound (US pachymetry. Methods. Seventy-six healthy subjects were prospectively measured 3 times by 1 operator using the TMS-5, 3 additional consecutive scans were performed by a second operator, and ultrasound (US pachymetry measurements were taken. The test-retest repeatability (TRT, coefficient of variation (CoV, and intraclass correlation coefficient (ICC were calculated to evaluate intraoperator repeatability and interoperator reproducibility. Agreement among the devices was assessed using Bland-Altman plots and 95% limits of agreement (LoA. Results. The intraoperators TRT and CoV were 0.90. The mean CCT and TCT measurements using the TMS-5 were 15.97 μm (95% LoA from −26.42 to −5.52 μm and 20.32 μm (95% LoA from −30.67 to −9.97 μm smaller, respectively, than those using US pachymetry. Conclusions. The TMS-5 shows good repeatability and reproducibility for measuring CCT and TCT in normal subjects but only moderate agreement with US pachymetry results. Caution is warranted before using these techniques interchangeably.

  10. Precision of Corneal Thickness Measurements Obtained Using the Scheimpflug-Placido Imaging and Agreement with Ultrasound Pachymetry

    Science.gov (United States)

    Huang, Jinhai; Wang, Chengfang; Lu, Weicong; Gao, Rongrong; Li, Yuanguang; Wang, Qinmei; Zhao, Yune

    2015-01-01

    Purpose. To assess the reliability and comparability of measuring central corneal thickness (CCT) and thinnest corneal thickness (TCT) using a new Scheimpflug-Placido analyzer (TMS-5, Japan) and ultrasound (US) pachymetry. Methods. Seventy-six healthy subjects were prospectively measured 3 times by 1 operator using the TMS-5, 3 additional consecutive scans were performed by a second operator, and ultrasound (US) pachymetry measurements were taken. The test-retest repeatability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability and interoperator reproducibility. Agreement among the devices was assessed using Bland-Altman plots and 95% limits of agreement (LoA). Results. The intraoperators TRT and CoV were 0.90. The mean CCT and TCT measurements using the TMS-5 were 15.97 μm (95% LoA from −26.42 to −5.52 μm) and 20.32 μm (95% LoA from −30.67 to −9.97 μm) smaller, respectively, than those using US pachymetry. Conclusions. The TMS-5 shows good repeatability and reproducibility for measuring CCT and TCT in normal subjects but only moderate agreement with US pachymetry results. Caution is warranted before using these techniques interchangeably. PMID:25810919

  11. Prostate Ultrasound

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    Full Text Available ... are the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe ... transducer into the body. top of page How is the procedure performed? In men, the prostate gland ...

  12. Ultrasound -- Pelvis

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    Full Text Available ... Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and organs ... of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography , ...

  13. Prostate Ultrasound

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    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... to-use and less expensive than other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning ...

  14. Ultrasound -- Pelvis

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    Full Text Available ... a pelvic ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... and processes the sounds and creates graphs or color pictures that represent the flow of blood through ...

  15. Ultrasound -- Pelvis

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    Full Text Available ... three types of pelvic ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently ... pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam ...

  16. Ultrasound -- Pelvis

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    Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: ...

  17. Sonographic evaluation of intravascular volume status: Can internal jugular or femoral vein collapsibility be used in the absence of IVC visualization?

    Directory of Open Access Journals (Sweden)

    Alistair Kent

    2015-01-01

    Full Text Available Introduction: Inferior vena cava collapsibility index (IVC-CI has been shown to correlate with both clinical and invasive assessment of intravascular volume status, but has important limitations such as the requirement for advanced sonographic skills, the degree of difficulty in obtaining those skills, and often challenging visualization of the IVC in the postoperative patient. The current study aims to explore the potential for using femoral (FV or internal jugular (IJV vein collapsibility as alternative sonographic options in the absence of adequate IVC visualization. Methods: A prospective, observational study comparing IVC-CI and Fem- and/or IJV-CI was performed in two intensive care units (ICU between January 2012 and April 2014. Concurrent M-mode measurements of IVC-CI and FV- and/or IJV-CI were collected during each sonographic session. Measurements of IVC were obtained using standard technique. IJV-CI and FV-CI were measured using high-frequency, linear array ultrasound probe placed in the corresponding anatomic areas. Paired data were analyzed using coefficient of correlation/determination and Bland-Altman determination of measurement bias. Results: We performed paired ultrasound examination of IVC-IJV (n = 39 and IVC-FV (n = 22, in 40 patients (mean age 54.1; 40% women. Both FV-CI and IJV-CI scans took less time to complete than IVC-CI scans (both, P < 0.02. Correlations between IVC-CI/FV-CI (R 2 = 0.41 and IVC-CI/IJV-CI (R 2 = 0.38 were weak. There was a mean -3.5% measurement bias between IVC-CI and IJV-CI, with trend toward overestimation for IJV-CI with increasing collapsibility. In contrast, FV-CI underestimated collapsibility by approximately 3.8% across the measured collapsibility range. Conclusion: Despite small measurement biases, correlations between IVC-CI and FV-/IJV-CI are weak. These results indicate that IJ-CI and FV-CI should not be used as a primary intravascular volume assessment tool for clinical decision support in

  18. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: ...

  19. Non-contact, ultrasound-based indentation method for measuring elastic properties of biological tissues using harmonic motion imaging (HMI).

    Science.gov (United States)

    Vappou, Jonathan; Hou, Gary Y; Marquet, Fabrice; Shahmirzadi, Danial; Grondin, Julien; Konofagou, Elisa E

    2015-04-07

    Noninvasive measurement of mechanical properties of biological tissues in vivo could play a significant role in improving the current understanding of tissue biomechanics. In this study, we propose a method for measuring elastic properties non-invasively by using internal indentation as generated by harmonic motion imaging (HMI). In HMI, an oscillating acoustic radiation force is produced by a focused ultrasound transducer at the focal region, and the resulting displacements are estimated by tracking radiofrequency signals acquired by an imaging transducer. In this study, the focal spot region was modeled as a rigid cylindrical piston that exerts an oscillatory, uniform internal force to the underlying tissue. The HMI elastic modulus EHMI was defined as the ratio of the applied force to the axial strain measured by 1D ultrasound imaging. The accuracy and the precision of the EHMI estimate were assessed both numerically and experimentally in polyacrylamide tissue-mimicking phantoms. Initial feasibility of this method in soft tissues was also shown in canine liver specimens in vitro. Very good correlation and agreement was found between the measured Young's modulus and the HMI modulus in the numerical study (r(2) > 0.99, relative error tissues at a submillimeter scale using an internal indentation-like approach. Ongoing studies include in vitro experiments in a larger number of samples and feasibility testing in in vivo models as well as pathological human specimens.

  20. Measurement of compartment elasticity using pressure related ultrasound: a method to identify patients with potential compartment syndrome.

    Science.gov (United States)

    Sellei, R M; Hingmann, S J; Kobbe, P; Weber, C; Grice, J E; Zimmerman, F; Jeromin, S; Gansslen, A; Hildebrand, F; Pape, H C

    2015-01-01

    PURPOSE OF THE STUDY Decision-making in treatment of an acute compartment syndrome is based on clinical assessment, supported by invasive monitoring. Thus, evolving compartment syndrome may require repeated pressure measurements. In suspected cases of potential compartment syndromes clinical assessment alone seems to be unreliable. The objective of this study was to investigate the feasibility of a non-invasive application estimating whole compartmental elasticity by ultrasound, which may improve accuracy of diagnostics. MATERIAL AND METHODS In an in-vitro model, using an artificial container simulating dimensions of the human anterior tibial compartment, intracompartmental pressures (p) were raised subsequently up to 80 mm Hg by infusion of saline solution. The compartmental depth (mm) in the cross-section view was measured before and after manual probe compression (100 mm Hg) upon the surface resulting in a linear compartmental displacement (Δd). This was repeated at rising compartmental pressures. The resulting displacements were related to the corresponding intra-compartmental pressures simulated in our model. A hypothesized relationship between pressures related compartmental displacement and the elasticity at elevated compartment pressures was investigated. RESULTS With rising compartmental pressures, a non-linear, reciprocal proportional relation between the displacement (mm) and the intra-compartmental pressure (mm Hg) occurred. The Pearson's coefficient showed a high correlation (r2 = -0.960). The intraobserver reliability value kappa resulted in a statistically high reliability (κ = 0.840). The inter-observer value indicated a fair reliability (κ = 0.640). CONCLUSIONS Our model reveals that a strong correlation between compartmental strain displacements assessed by ultrasound and the intra-compartmental pressure changes occurs. Further studies are required to prove whether this assessment is transferable to human muscle tissue. Determining the complete

  1. The effect of the sample size and location on contrast ultrasound measurement of perfusion parameters.

    Science.gov (United States)

    Leinonen, Merja R; Raekallio, Marja R; Vainio, Outi M; Ruohoniemi, Mirja O; O'Brien, Robert T

    2011-01-01

    Contrast-enhanced ultrasound can be used to quantify tissue perfusion based on region of interest (ROI) analysis. The effect of the location and size of the ROI on the obtained perfusion parameters has been described in phantom, ex vivo and in vivo studies. We assessed the effects of location and size of the ROI on perfusion parameters in the renal cortex of 10 healthy, anesthetized cats using Definity contrast-enhanced ultrasound to estimate the importance of the ROI on quantification of tissue perfusion with contrast-enhanced ultrasound. Three separate sets of ROIs were placed in the renal cortex, varying in location, size or depth. There was a significant inverse association between increased depth or increased size of the ROI and peak intensity (P < 0.05). There was no statistically significant difference in the peak intensity between the ROIs placed in a row in the near field cortex. There was no significant difference in the ROIs with regard to arrival time, time to peak intensity and wash-in rate. When comparing two different ROIs in a patient with focal lesions, such as suspected neoplasia or infarction, the ROIs should always be placed at same depth and be as similar in size as possible.

  2. A tissue phantom for visualization and measurement of ultrasound-induced cavitation damage.

    Science.gov (United States)

    Maxwell, Adam D; Wang, Tzu-Yin; Yuan, Lingqian; Duryea, Alexander P; Xu, Zhen; Cain, Charles A

    2010-12-01

    Many ultrasound studies involve the use of tissue-mimicking materials to research phenomena in vitro and predict in vivo bioeffects. We have developed a tissue phantom to study cavitation-induced damage to tissue. The phantom consists of red blood cells suspended in an agarose hydrogel. The acoustic and mechanical properties of the gel phantom were found to be similar to soft tissue properties. The phantom's response to cavitation was evaluated using histotripsy. Histotripsy causes breakdown of tissue structures by the generation of controlled cavitation using short, focused, high-intensity ultrasound pulses. Histotripsy lesions were generated in the phantom and kidney tissue using a spherically focused 1-MHz transducer generating 15 cycle pulses, at a pulse repetition frequency of 100 Hz with a peak negative pressure of 14 MPa. Damage appeared clearly as increased optical transparency of the phantom due to rupture of individual red blood cells. The morphology of lesions generated in the phantom was very similar to that generated in kidney tissue at both macroscopic and cellular levels. Additionally, lesions in the phantom could be visualized as hypoechoic regions on a B-mode ultrasound image, similar to histotripsy lesions in tissue. High-speed imaging of the optically transparent phantom was used to show that damage coincides with the presence of cavitation. These results indicate that the phantom can accurately mimic the response of soft tissue to cavitation and provide a useful tool for studying damage induced by acoustic cavitation.

  3. Children's (Pediatric) Abdominal Ultrasound Imaging

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    Full Text Available ... may also be saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  4. Hypothesis: Disseminated Intravascular Inflammation as the Inflammatory Counterpart to Disseminated Intravascular Coagulation

    Science.gov (United States)

    Bull, Brian S.; Bull, Maureen H.

    1994-08-01

    We have identified a leukocyte activation syndrome that is occasionally associated with the transfusion of intraoperatively recovered erythrocytes. This syndrome appears to result from intravascular damage caused by leukocytes activated during the erythrocyte salvage process. We hypothesize that this syndrome is part of a larger disease grouping: disseminated intravascular inflammation (DII). DII is the analog of the coagulation disorder disseminated intravascular coagulation. In disseminated intravascular coagulation, the organ damage results from uncontrolled activation of the clotting pathway; in DII the damage is caused by leukocytes that have become activated by direct contact with bacteria or in rare instances-such as erythrocyte salvage-in the absence of bacteria and bacterial products. Recent studies of the hazards associated with intraoperative blood salvage indicate that activation of leukocytes can be achieved by exposure to activated platelets alone. If such activated leukocytes are reinfused along with the washed erythrocytes, widespread organ damage may result. The lung is the organ most severely affected by activated leukocytes. Adult respiratory distress syndrome is one outcome. It is likely that DII is a presently unrecognized pathophysiological process that complicates a variety of primary disease states and increases their lethality.

  5. The World Health Organization Fetal Growth Charts: A Multinational Longitudinal Study of Ultrasound Biometric Measurements and Estimated Fetal Weight

    Science.gov (United States)

    Carroli, Guillermo; Widmer, Mariana; Neerup Jensen, Lisa; Giordano, Daniel; Abdel Aleem, Hany; Talegawkar, Sameera A.; Benachi, Alexandra; Diemert, Anke; Tshefu Kitoto, Antoinette; Thinkhamrop, Jadsada; Lumbiganon, Pisake; Tabor, Ann; Kriplani, Alka; Gonzalez Perez, Rogelio; Hecher, Kurt; Hanson, Mark A.; Gülmezoglu, A. Metin; Platt, Lawrence D.

    2017-01-01

    Background Perinatal mortality and morbidity continue to be major global health challenges strongly associated with prematurity and reduced fetal growth, an issue of further interest given the mounting evidence that fetal growth in general is linked to degrees of risk of common noncommunicable diseases in adulthood. Against this background, WHO made it a high priority to provide the present fetal growth charts for estimated fetal weight (EFW) and common ultrasound biometric measurements intended for worldwide use. Methods and Findings We conducted a multinational prospective observational longitudinal study of fetal growth in low-risk singleton pregnancies of women of high or middle socioeconomic status and without known environmental constraints on fetal growth. Centers in ten countries (Argentina, Brazil, Democratic Republic of the Congo, Denmark, Egypt, France, Germany, India, Norway, and Thailand) recruited participants who had reliable information on last menstrual period and gestational age confirmed by crown–rump length measured at 8–13 wk of gestation. Participants had anthropometric and nutritional assessments and seven scheduled ultrasound examinations during pregnancy. Fifty-two participants withdrew consent, and 1,387 participated in the study. At study entry, median maternal age was 28 y (interquartile range [IQR] 25–31), median height was 162 cm (IQR 157–168), median weight was 61 kg (IQR 55–68), 58% of the women were nulliparous, and median daily caloric intake was 1,840 cal (IQR 1,487–2,222). The median pregnancy duration was 39 wk (IQR 38–40) although there were significant differences between countries, the largest difference being 12 d (95% CI 8–16). The median birthweight was 3,300 g (IQR 2,980–3,615). There were differences in birthweight between countries, e.g., India had significantly smaller neonates than the other countries, even after adjusting for gestational age. Thirty-one women had a miscarriage, and three fetuses had

  6. The World Health Organization Fetal Growth Charts: A Multinational Longitudinal Study of Ultrasound Biometric Measurements and Estimated Fetal Weight.

    Directory of Open Access Journals (Sweden)

    Torvid Kiserud

    2017-01-01

    Full Text Available Perinatal mortality and morbidity continue to be major global health challenges strongly associated with prematurity and reduced fetal growth, an issue of further interest given the mounting evidence that fetal growth in general is linked to degrees of risk of common noncommunicable diseases in adulthood. Against this background, WHO made it a high priority to provide the present fetal growth charts for estimated fetal weight (EFW and common ultrasound biometric measurements intended for worldwide use.We conducted a multinational prospective observational longitudinal study of fetal growth in low-risk singleton pregnancies of women of high or middle socioeconomic status and without known environmental constraints on fetal growth. Centers in ten countries (Argentina, Brazil, Democratic Republic of the Congo, Denmark, Egypt, France, Germany, India, Norway, and Thailand recruited participants who had reliable information on last menstrual period and gestational age confirmed by crown-rump length measured at 8-13 wk of gestation. Participants had anthropometric and nutritional assessments and seven scheduled ultrasound examinations during pregnancy. Fifty-two participants withdrew consent, and 1,387 participated in the study. At study entry, median maternal age was 28 y (interquartile range [IQR] 25-31, median height was 162 cm (IQR 157-168, median weight was 61 kg (IQR 55-68, 58% of the women were nulliparous, and median daily caloric intake was 1,840 cal (IQR 1,487-2,222. The median pregnancy duration was 39 wk (IQR 38-40 although there were significant differences between countries, the largest difference being 12 d (95% CI 8-16. The median birthweight was 3,300 g (IQR 2,980-3,615. There were differences in birthweight between countries, e.g., India had significantly smaller neonates than the other countries, even after adjusting for gestational age. Thirty-one women had a miscarriage, and three fetuses had intrauterine death. The 8,203 sets of

  7. The World Health Organization Fetal Growth Charts: A Multinational Longitudinal Study of Ultrasound Biometric Measurements and Estimated Fetal Weight.

    Science.gov (United States)

    Kiserud, Torvid; Piaggio, Gilda; Carroli, Guillermo; Widmer, Mariana; Carvalho, José; Neerup Jensen, Lisa; Giordano, Daniel; Cecatti, José Guilherme; Abdel Aleem, Hany; Talegawkar, Sameera A; Benachi, Alexandra; Diemert, Anke; Tshefu Kitoto, Antoinette; Thinkhamrop, Jadsada; Lumbiganon, Pisake; Tabor, Ann; Kriplani, Alka; Gonzalez Perez, Rogelio; Hecher, Kurt; Hanson, Mark A; Gülmezoglu, A Metin; Platt, Lawrence D

    2017-01-01

    Perinatal mortality and morbidity continue to be major global health challenges strongly associated with prematurity and reduced fetal growth, an issue of further interest given the mounting evidence that fetal growth in general is linked to degrees of risk of common noncommunicable diseases in adulthood. Against this background, WHO made it a high priority to provide the present fetal growth charts for estimated fetal weight (EFW) and common ultrasound biometric measurements intended for worldwide use. We conducted a multinational prospective observational longitudinal study of fetal growth in low-risk singleton pregnancies of women of high or middle socioeconomic status and without known environmental constraints on fetal growth. Centers in ten countries (Argentina, Brazil, Democratic Republic of the Congo, Denmark, Egypt, France, Germany, India, Norway, and Thailand) recruited participants who had reliable information on last menstrual period and gestational age confirmed by crown-rump length measured at 8-13 wk of gestation. Participants had anthropometric and nutritional assessments and seven scheduled ultrasound examinations during pregnancy. Fifty-two participants withdrew consent, and 1,387 participated in the study. At study entry, median maternal age was 28 y (interquartile range [IQR] 25-31), median height was 162 cm (IQR 157-168), median weight was 61 kg (IQR 55-68), 58% of the women were nulliparous, and median daily caloric intake was 1,840 cal (IQR 1,487-2,222). The median pregnancy duration was 39 wk (IQR 38-40) although there were significant differences between countries, the largest difference being 12 d (95% CI 8-16). The median birthweight was 3,300 g (IQR 2,980-3,615). There were differences in birthweight between countries, e.g., India had significantly smaller neonates than the other countries, even after adjusting for gestational age. Thirty-one women had a miscarriage, and three fetuses had intrauterine death. The 8,203 sets of ultrasound

  8. Automatic Ultrasound Scanning

    DEFF Research Database (Denmark)

    Moshavegh, Ramin

    Medical ultrasound has been a widely used imaging modality in healthcare platforms for examination, diagnostic purposes, and for real-time guidance during surgery. However, despite the recent advances, medical ultrasound remains the most operator-dependent imaging modality, as it heavily relies...... on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

  9. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound

    Directory of Open Access Journals (Sweden)

    John R. Eisenbrey

    2015-01-01

    Full Text Available Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency, subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  10. Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound.

    Science.gov (United States)

    Eisenbrey, John R; Sridharan, Anush; Liu, Ji-Bin; Forsberg, Flemming

    2015-01-01

    Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency), subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imaging in vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

  11. The Diagnosis and Man Disseminated Intravascular Coagulation

    Institute of Scientific and Technical Information of China (English)

    Flelcher B.; Taylor.Jr

    2003-01-01

    @@ This review describes disseminated intravascular coagulation(DIC) as a syndrome in which hemostatic factors are activated and products are generated. This syndrome ranges in severity from an obvious decompensated coagulopathy (overt-DIC) to the subclinical compensated activation of hemostatic factors(non-overt DIC). Ths first part of this review emphasizes two points: First, activation of the hemostatic system is controlled by a vast network of capillaries and venules through anticoagulant and antiinflammatory regulatory factors that operate from the endothelium( e. G. , protein C and thrombomodulin, tissue factor pathway inhibitor).

  12. Delivery efficiency of periadventitial approach in comparison of intravascular delivery: an assessment of pharmacokinetics in porcine arteries

    Institute of Scientific and Technical Information of China (English)

    Yong-hua Xu; Gordon McLennan

    2005-01-01

    Objective To investigate the delivery efficacy of periadventitial delivery of 125I-iododeoxyuridine (125I-IUdR) in comparison of intravascular delivery to determine the optimal delivery method for inhibiting post-angioplasty restenosis. Methods In 8 pigs, one side carotid, subclavian and iliac arteries of each pig were injured by balloon angioplasty with a 20% overstretches. Then, 4 mCi of 125I-IUdR was delivered at each targeted vessel with periadventitial method in 4 pigs (periadventitial group) and with intravascular method via a porous balloon catheter in other 4 pigs (intravascular group). The animals survived for 5 hours and the blood radioactivity was investigated prior to and hourly after procedure until sacrifice. The targeted vessels and renal arteries (for control) were harvested for gamma-counting and histological observation. Meanwhile, the radioactivity in thyroid, liver, bladder, small bowel and each kidney also were measured to determine the biodistribution of 125I. The activities of 125I presented in arterial and tissue specimens were compared between the two delivery groups. The targeted arteries were histologically observed and the ratio of intima to media (I∶M ratio) was calculated. Results The target arterial walls in the periadventitial group had 3.4 times as much of 125I radioactivity as in the intravascular group, respectively (P=0.038); the blood activity in intravascular group was significantly higher than periadventitial group immediate after procedure (P0.05). The mean I: M ratios in both groups were 0.05 without additional injury at the vessel wall. Conclusion The periadventitial delivery offered substantial advantage over intravascular approach with high local delivery efficacy. The apparent redistribution rate is more rapid following intravascular delivery.

  13. Associations between Handgrip Strength and Ultrasound-Measured Muscle Thickness of the Hand and Forearm in Young Men and Women.

    Science.gov (United States)

    Abe, Takashi; Counts, Brittany R; Barnett, Brian E; Dankel, Scott J; Lee, Kofan; Loenneke, Jeremy P

    2015-08-01

    It is unknown whether muscle size of intrinsic hand muscles is associated with handgrip strength. To investigate the relationships between handgrip strength and flexor muscle size of the hand and forearm, muscle thickness (MT) of 86 young adults (43 men and 43 women) between the ages of 18 and 34 y was measured by ultrasound. Two MTs (forearm radius and forearm ulna MT) in the anterior forearm, two MTs (lumbrical and dorsal interosseous MT) in the anterior hand and handgrip strength were measured on the right side. Linear regression with part (also referred to as semipartial) correlation coefficients revealed that forearm ulna MT positively correlated with handgrip strength in both men (part = 0.379, p = 0.001) and women (part = 0.268, p = 0.002). Dorsal interosseous MT correlated with handgrip strength in women only (part = 0.289, p = 0.001). Our results suggest that the forearm ulna and dorsal interosseous MTs for women and forearm ulna MTs for men are factors contributing to prediction of handgrip strength in young adults. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  14. Effect of oral contraceptive with and without associated estriol on ultrasound measurements of breast fibroadenoma: randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Rodrigo Augusto Fernandes Estevão

    Full Text Available CONTEXT AND OBJECTIVE: Fibroadenomas are the most common benign tumors of the female breast. The aim of this study was to evaluate the proliferative activity of breast fibroadenoma as shown by ultrasound measurements, following administration of oral contraceptives with and without associated estriol. DESIGN AND SETTING: This was a randomized, double-blind, placebo-controlled clinical trial carried out in the Mastology Sector, Department of Gynecology, Universidade Federal de São Paulo. METHODS: We studied 33 women with fibroadenomas. Ten were placed in group 1 and took an oral contraceptive consisting of levonorgestrel and ethinyl estradiol together with placebo material in the same capsule, for four consecutive cycles with a seven-day interval between them. The other 23 patients constituted group 2 and took the oral contraceptive as above together with estriol in the same capsule, in the same way as done by the group 1 patients. We took ultrasound measurements of their tumors (in three dimensions before and after the intake of medication. At the end of the study, all the patients had their tumors removed by surgery. RESULTS: We observed decreased fibroadenoma width among the users of oral contraceptives with placebo, and this decrease was statistically significant. In the other group, we did not observe any changes (in width, length or height. CONCLUSION: The results confirm that estriol may block the protective effect of oral contraceptives on fibroadenomas, since we observed decreased fibroadenoma width among the group 1 patients but not the group 2 patients.

  15. Development of a body condition scoring index for female African elephants validated by ultrasound measurements of subcutaneous fat.

    Science.gov (United States)

    Morfeld, Kari A; Lehnhardt, John; Alligood, Christina; Bolling, Jeff; Brown, Janine L

    2014-01-01

    Obesity-related health and reproductive problems may be contributing to non-sustainability of zoo African elephant (Loxodonta africana) populations. However, a major constraint in screening for obesity in elephants is lack of a practical method to accurately assess body fat. Body condition scoring (BCS) is the assessment of subcutaneous fat stores based on visual evaluation and provides an immediate appraisal of the degree of obesity of an individual. The objective of this study was to develop a visual BCS index for female African elephants and validate it using ultrasound measures of subcutaneous fat. To develop the index, standardized photographs were collected from zoo (n = 50) and free-ranging (n = 57) female African elephants for identifying key body regions and skeletal features, which were then used to visually determine body fat deposition patterns. This information was used to develop a visual BCS method consisting of a list of body regions and the physical criteria for assigning an overall score on a 5-point scale, with 1 representing the lowest and 5 representing the highest levels of body fat. Results showed that as BCS increased, ultrasound measures of subcutaneous fat thickness also increased (Pelephants, the median BCS in the free-ranging individuals (BCS = 3, range 1-5) was lower (Pelephants. This tool can be used to examine which factors impact body condition in zoo and free-ranging elephants, providing valuable information on how it affects health and reproductive potential of individual elephants.

  16. Exploiting Ultrasound Harmonics

    NARCIS (Netherlands)

    G.M. Matte (Guillaume)

    2010-01-01

    textabstractUltrasound imaging is an inexpensive method which provides an accurate diagnosis tool. This thesis provides elements to characterise the acoustic pressure generated by ultrasound transducers as well as signal processing method that could improve modern echography. The first measurement

  17. Exploiting Ultrasound Harmonics

    NARCIS (Netherlands)

    G.M. Matte (Guillaume)

    2010-01-01

    textabstractUltrasound imaging is an inexpensive method which provides an accurate diagnosis tool. This thesis provides elements to characterise the acoustic pressure generated by ultrasound transducers as well as signal processing method that could improve modern echography. The first measurement

  18. Pulsed liquid microjet for intravascular injection

    Science.gov (United States)

    Palanker, Daniel V.; Fletcher, Daniel A.; Miller, Jason; Huie, Philip; Marmor, Michael; Blumenkranz, Mark S.

    2002-06-01

    Occlusions of the retinal veins and arteries are associated with common diseases such as hypertension and arteriosclerosis and usually cause severe and irreversible loss of vision. Treatments for these vascular diseases have been unsatisfactory to date in part because of the difficulty of delivering thrombolytic drugs locally within the eye. In this article we describe a pulsed liquid microjet for minimally invasive intra-vascular drug delivery. The microjet is driven by a vapor bubble following an explosive evaporation of saline, produced by a microsecond-long electric discharge in front of the 25 micrometers electrode inside the micronozzle. Expansion of the transient vapor bubble produces a water jet with a diameter equal to the diameter of the nozzle, and with a velocity and duration that are controlled by the pulse energy. We found that fluid could be injected through the wall of a 60-micrometers -diameter artery in choriallantoic membrane using a 15-micrometers diameter liquid jet traveling at more than 60 m/s. Histological analysis of these arteries showed that the width of the perforation is limited to the diameter of the micronozzle, and the penetration depth of the jet is controlled by the discharge energy. The pulsed liquid microjet offers a promising technique for precise and needle-free intravascular delivery of thrombolytic drugs for localized treatment of retinal vascular occlusions.

  19. Value of intravascular ultrasound in the assessment of pulmonary vascular properties and mortality in patients with pulmonary artery hypertension associated with connective tissue diseases%血管内超声评估结缔组织病相关性肺动脉高压患者肺血管性能和病死率

    Institute of Scientific and Technical Information of China (English)

    蔡宗烨; 李剑; 孙灵跃; 杨程德; 沈节艳; 何奔

    2015-01-01

    血管性能恶化,而其中PAH-CTD患者较其他类型的PAH患者好.PAH-CTD患者与其他类型的PAH患者的生存曲线未见明显差异,而在PAH患者中肺血管远端重塑型病死率较近端重塑型高.%Objective To investigate the value of intravascular ultrasound (IVUS) on assessing pulmonary vascular properties (PVPs) and its relationship with hemodynamics,and mortality rate in patients with pulmonary arterial hypertension associated with connective tissue disease (PAH-CTD).Methods Patients (n =51) with highly suspected PAH-CTD were prospectively enrolled in our department between July 2011 and March 2014.All patients underwent right heart catheterization (RHC) and IVUS,and were divided into 3 groups:PAH-CTD (n =25),PAH due to other reasons (n =15),and non-PAH control group (n=11).Based on IVUS,PAH patients were divided into distal (n =22) and proximal (n =18) remodeling subtypes.A total of 408 pulmonary segments were detected by IVUS,and all patients were followed up to (19 ± 10) months.Results IVUS evidenced higher mean wall thickness (MWT) ((0.30 ± 0.02) mm and (0.33 ± 0.02) mm vs.(0.21 ± 0.02) rmm) and percentage of MWT (WTP) ((13.62 ± 0.59)% and (14.39 0.77)% vs.(9.57 ±0.97)%) values in PAH patients compared to control patients (all P < 0.01).Pulmonary vascular mechanical properties (PVMPs) including compliance ((8.85 ± 0.82) × 10 2-mm2/mmHg(1 mmHg =0.133 kPa) and (6.28 ± 0.65) × 10--2 mm2/mmHg vs.(41.59 ± 5.02) × 10-2 mm2-/mmHg,all P < 0.01),distensibility ((0.83 ± 0.09)%/mmHg and (0.55 ±0.06)%/mmHg vs.(3.16 ±0.38) %/mmHg,all P <0.01),elastic modulus ((169.25 ± 15.10) mmHg and (253.00 ± 22.11) mmHg vs.(43.78 ± 4.27) mmHg,all P < 0.01) and stiffness index 3 (4.19 ±0.41 and 5.18 ±0.34 vs.2.39 ±0.27,P <0.05 or 0.01) in PAH groups were all significantly worse than in control group (all P <0.01).An inverse exponential association was found between PVMPs and hemodynamics with R2 ranging from 0.544 to 0

  20. Dynamic Limb Bioimpedance and Inferior Vena Cava Ultrasound in Patients Undergoing Hemodialysis.

    Science.gov (United States)

    Tiba, Mohamad H; Belmont, Barry; Heung, Michael; Theyyunni, Nik; Huang, Robert D; Fung, Christopher M; Pennington, Amanda J; Cummings, Brandon C; Draucker, Gerard T; Shih, Albert J; Ward, Kevin R

    2016-01-01

    Assessment of volume status in critically ill patients poses a challenge to clinicians. Measuring changes in the inferior vena cava (IVC) diameter using ultrasound is becoming a standard tool to assess volume status. Ultrasound requires physicians with significant training and specialized expensive equipment. It would be of significant value to be able to obtain this measurement continuously without physician presence. We hypothesize that dynamic changes in limb's bioimpedance in response to respiration could be used to predict changes in IVC. Forty-six subjects were tested a hemodialysis session. Impedance was measured via electrodes placed on the arm. Simultaneously, the IVC diameter was assessed by ultrasound. Subjects were asked to breathe spontaneously and perform respiratory maneuvers using a respiratory training device. Impedance (dz) was determined and compared with change in IVC diameter (dIVC; r = 0.76, p < 0.0001). There was significant relationship between dz and dIVC (p< 0.0001). Receiver-operator curves for dz at thresholds of dIVC (20% to70%) demonstrated high predictive power with areas under the curves (0.87-0.99, p < 0.0001). This evaluation suggests that real-time dynamic changes in limb impedance are capable of tracking a wide range of dynamic dIVC. This technique might be a suitable surrogate for monitoring real-time changes in dIVC to assess intravascular volume status.

  1. Measurement of anterior and posterior circulation flow contributions to cerebral blood flow. An ultrasound-derived volumetric flow analysis.

    Science.gov (United States)

    Boyajian, R A; Schwend, R B; Wolfe, M M; Bickerton, R E; Otis, S M

    1995-01-01

    Ultrasound-derived volumetric flow analysis may be useful in answering questions of basic physiological interest in the cerebrovascular circulation. Using this technique, the authors have sought to describe quantitatively the complete concurrent flow relations among all four arteries supplying the brain. The aim of this study of normal subjects was to determine the relative flow contributions of the anterior (internal carotid arteries) and posterior (vertebral arteries) cerebral circulation. Comparisons between the observed and theoretically expected anterior and posterior flow distribution would provide an opportunity to assess traditional rheological conceptions in vivo. Pulsed color Doppler ultrasonography was used to measure mean flow rates in the internal carotid and vertebral arteries in 21 normal adults. The anterior circulation (internal carotid arteries bilaterally) carried 82% of the brain's blood supply and comprised 67% of the total vascular cross-sectional area. These values demonstrate precise concordance between observations in vivo and the theoretically derived (Hagen-Poiseuille) expected flow distribution. These cerebrovascular findings support the traditional conception of macroscopic blood flow. Further studies using ultrasound-derived volumetric analysis of the brain's arterial flow relations may illuminate the vascular pathophysiology underlying aging, cerebral ischemia, and dementias.

  2. Bayesian genome-wide association analysis of growth and yearling ultrasound measures of carcass traits in Brangus heifers.

    Science.gov (United States)

    Peters, S O; Kizilkaya, K; Garrick, D J; Fernando, R L; Reecy, J M; Weaber, R L; Silver, G A; Thomas, M G

    2012-10-01

    Data from developing Brangus heifers (3/8 Brahman-Bos indicus × 5/8 Angus-Bos taurus; n ≈ 802 from 67 sires) registered with International Brangus Breeders Association were analyzed to detect QTL associated with growth traits and ultrasound measures of carcass traits. Genotypes were from BovineSNP50 (Infinium BeadChip, Illumina, San Diego, CA; 53,692 SNP). Phenotypes included BW collected at birth and ∼205 and 365 d of age, and yearling ultrasound assessment of LM area, percent intramuscular fat, and depth of rib fat. Simultaneous association of SNP windows with phenotype were undertaken with Bayes C analyses, using GenSel software. The SNP windows were ≈ 5 SNP in length. Analyses fitted a mixture model that treated SNP effects as random, with an assumed fraction pi = 0.999 having no effect on phenotype. Bootstrap analyses were used to obtain significance values for the SNP windows with the greatest contribution to observed variation. The SNP windows with P carcass traits in developing Brangus heifers confirmed several published QTL and detected several new QTL.

  3. The relation between tongue shape and pitch in clarinet playing using ultrasound measurements.

    Science.gov (United States)

    Lulich, Steven M; Charles, Sherman; Lulich, Benjamin

    2017-03-01

    Tongue shapes during clarinet performances of chromatic scale, portamento and pitch bending exercises were imaged using an ultrasound machine while audio and video were recorded synchronously. Analysis of the data from four participants revealed that tongue position varies non-monotically with note frequency in the lowest register (up to ≈ 440 Hz) and then descends monotonically as note frequencies rise through the upper registers. The descent of the tongue results in an expansion of the vocal tract's posterior oral cavity, resulting in a vocal tract input impedance maximum tuned to high frequency. Portamento and pitch bending were found to involve a raising of the tongue and concomitant contraction of the posterior oral cavity. The degree of contraction was similar in both portamento and pitch bending, suggesting a common acoustic mechanism.

  4. Intravascular ultrasonic-photoacoustic (IVUP) endoscope with 2.2-mm diameter catheter for medical imaging.

    Science.gov (United States)

    Bui, Nhat Quang; Hlaing, Kyu Kyu; Nguyen, Van Phuc; Nguyen, Trung Hau; Oh, Yun-Ok; Fan, Xiao Feng; Lee, Yong Wook; Nam, Seung Yun; Kang, Hyun Wook; Oh, Junghwan

    2015-10-01

    Intravascular ultrasound (IVUS) imaging is extremely important for detection and characterization of high-risk atherosclerotic plaques as well as gastrointestinal diseases. Recently, intravascular photoacoustic (IVPA) imaging has been used to differentiate the composition of biological tissues with high optical contrast and ultrasonic resolution. The combination of these imaging techniques could provide morphological information and molecular screening to characterize abnormal tissues, which would help physicians to ensure vital therapeutic value and prognostic significance for patients before commencing therapy. In this study, integration of a high-frequency IVUS imaging catheter (45MHz, single-element, unfocused, 0.7mm in diameter) with a multi-mode optical fiber (0.6mm in core diameter, 0.22 NA), an integrated intravascular ultrasonic-photoacoustic (IVUP) imaging catheter, was developed to provide spatial and functional information on light distribution in a turbid sample. Simultaneously, IVUS imaging was co-registered to IVPA imaging to construct 3D volumetric sample images. In a phantom study, a polyvinyl alcohol (PVA) tissue-mimicking arterial vessel phantom with indocyanine green (ICG) and methylene blue (MB) inclusion was used to demonstrate the feasibility of mapping the biological dyes, which are used in cardiovascular and cancer diagnostics. For the ex vivo study, an excised sample of pig intestine with ICG was utilized to target the biomarkers present in the gastrointestinal tumors or the atherosclerotic plaques with the proposed hybrid technique. The results indicated that IVUP endoscope with the 2.2-mm diameter catheter could be a useful tool for medical imaging. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. A comparison of ultrasound measurements to assess carotid atherosclerosis development in subjects with and without type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Zinman Bernard

    2005-06-01

    Full Text Available Abstract Background Subjects with type 2 diabetes are at an increased risk of vascular complications. The use of carotid ultrasound remains an attractive, non-invasive method to monitor atherosclerotic disease progression and/or response to treatment in patients with type 2 diabetes, with intima-media thickness routinely used as the gold standard to detect pathology. However, alternative measurements, such as plaque area or volume, may represent a potentially more powerful approach. Thus, the objective of this study was to compare the traditional intima-media thickness measurement against the novel total plaque volume measurement in analyzing carotid atherosclerosis development in individuals with type 2 diabetes. Methods The case-control study included 49 Oji-Cree adults with diabetes or impaired glucose tolerance, aged 21–69, and 49 sex- and age-matched normoglycemic subjects. At baseline, metabolic variables were measured, including body mass index, waist circumference, total cholesterol:high density lipoprotein ratio, plasma triglycerides, plasma glucose, and serum insulin. Carotid ultrasound measurements, 7 years later, assessed carotid arterial intima-media thickness and total plaque volume. Results At baseline, the two groups were well matched for smoking habits, hypertension, body mass index, and waist circumference. Differences were noted in baseline measurements of total cholesterol:high density lipoprotein (P = 0.0006, plasma triglycerides (P P P = 0.037, but not intima-media thickness measurements, were higher in subjects with diabetes/impaired glucose tolerance compared to the normoglycemic controls. Correlation between intima-media thickness and total plaque volume was moderate. Based on our study findings, to achieve power levels >0.70 when comparing intima-media thickness measurements for diabetics versus non-diabetics, thousands of study subjects are required. For comparing total plaque volume measurements, only hundreds of

  6. Central corneal thickness measurements using Orbscan II, Visante, ultrasound, and Pentacam pachymetry after laser in situ keratomileusis for myopia.

    Science.gov (United States)

    Ho, Thomas; Cheng, Arthur C K; Rao, Srinivas K; Lau, Silvania; Leung, Chris K S; Lam, Dennis S C

    2007-07-01

    To compare corneal pachymetry assessment using 4 measurement methods in eyes after laser in situ keratomileusis (LASIK) for myopia. Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Hong Kong SAR. Fifty-two consecutive patients (103 eyes) who had LASIK for the correction of myopia had Orbscan II (Bausch & Lomb), Visante (Carl Zeiss Meditec), Pentacam (Oculus, Inc.), and ultrasound (US) pachymetry (Sonomed, 200P) 6 months after surgery. Data were analyzed using the paired sample t test, Bland-Altman plots, and linear regression. The mean postoperative pachymetry measured by US, Orbscan (0.89 acoustic factor), Pentacam, and Visante pachymetry were 438.2 microm+/-41.18 (SD), 435.17+/-49.63 microm, 430.66+/-40.23 microm, and 426.56+/-41.6 microm, respectively. Compared with the US measurement, Pentacam and Visante measurements significantly underestimated corneal thickness by a mean of 7.54+/-15.06 microm (P<.01) and 11.64+/-12.87 microm (P<.01), respectively. There was no statistically significant difference between US and Orbscan measurements. Pentacam and Visante measurements of corneal thickness 6 months after LASIK were significantly less than those obtained using Orbscan and US pachymetry, although all 4 measurement methods showed a high correlation with each other.

  7. Accurate lumen diameter measurement in curved vessels in carotid ultrasound: an iterative scale-space and spatial transformation approach.

    Science.gov (United States)

    Krishna Kumar, P; Araki, Tadashi; Rajan, Jeny; Saba, Luca; Lavra, Francesco; Ikeda, Nobutaka; Sharma, Aditya M; Shafique, Shoaib; Nicolaides, Andrew; Laird, John R; Gupta, Ajay; Suri, Jasjit S

    2016-12-10

    Monitoring of cerebrovascular diseases via carotid ultrasound has started to become a routine. The measurement of image-based lumen diameter (LD) or inter-adventitial diameter (IAD) is a promising approach for quantification of the degree of stenosis. The manual measurements of LD/IAD are not reliable, subjective and slow. The curvature associated with the vessels along with non-uniformity in the plaque growth poses further challenges. This study uses a novel and generalized approach for automated LD and IAD measurement based on a combination of spatial transformation and scale-space. In this iterative procedure, the scale-space is first used to get the lumen axis which is then used with spatial image transformation paradigm to get a transformed image. The scale-space is then reapplied to retrieve the lumen region and boundary in the transformed framework. Then, inverse transformation is applied to display the results in original image framework. Two hundred and two patients' left and right common carotid artery (404 carotid images) B-mode ultrasound images were retrospectively analyzed. The validation of our algorithm has done against the two manual expert tracings. The coefficient of correlation between the two manual tracings for LD was 0.98 (p < 0.0001) and 0.99 (p < 0.0001), respectively. The precision of merit between the manual expert tracings and the automated system was 97.7 and 98.7%, respectively. The experimental analysis demonstrated superior performance of the proposed method over conventional approaches. Several statistical tests demonstrated the stability and reliability of the automated system.

  8. Development of a body condition scoring index for female African elephants validated by ultrasound measurements of subcutaneous fat.

    Directory of Open Access Journals (Sweden)

    Kari A Morfeld

    Full Text Available Obesity-related health and reproductive problems may be contributing to non-sustainability of zoo African elephant (Loxodonta africana populations. However, a major constraint in screening for obesity in elephants is lack of a practical method to accurately assess body fat. Body condition scoring (BCS is the assessment of subcutaneous fat stores based on visual evaluation and provides an immediate appraisal of the degree of obesity of an individual. The objective of this study was to develop a visual BCS index for female African elephants and validate it using ultrasound measures of subcutaneous fat. To develop the index, standardized photographs were collected from zoo (n = 50 and free-ranging (n = 57 female African elephants for identifying key body regions and skeletal features, which were then used to visually determine body fat deposition patterns. This information was used to develop a visual BCS method consisting of a list of body regions and the physical criteria for assigning an overall score on a 5-point scale, with 1 representing the lowest and 5 representing the highest levels of body fat. Results showed that as BCS increased, ultrasound measures of subcutaneous fat thickness also increased (P<0.01, indicating the scores closely coincide with physical measures of fat reserves. The BCS index proved to be reliable and repeatable based on high intra- and inter-assessor agreement across three assessors. In comparing photographs of wild vs. captive African elephants, the median BCS in the free-ranging individuals (BCS = 3, range 1-5 was lower (P<0.001 than that of the zoo population (BCS = 4, range 2-5. In sum, we have developed the first validated BCS index for African elephants. This tool can be used to examine which factors impact body condition in zoo and free-ranging elephants, providing valuable information on how it affects health and reproductive potential of individual elephants.

  9. Automatic Measurement of Thalamic Diameter in 2-D Fetal Ultrasound Brain Images Using Shape Prior Constrained Regularized Level Sets.

    Science.gov (United States)

    Sridar, Pradeeba; Kumar, Ashnil; Li, Changyang; Woo, Joyce; Quinton, Ann; Benzie, Ron; Peek, Michael J; Feng, Dagan; Kumar, R Krishna; Nanan, Ralph; Kim, Jinman

    2017-07-01

    We derived an automated algorithm for accurately measuring the thalamic diameter from 2-D fetal ultrasound (US) brain images. The algorithm overcomes the inherent limitations of the US image modality: nonuniform density; missing boundaries; and strong speckle noise. We introduced a "guitar" structure that represents the negative space surrounding the thalamic regions. The guitar acts as a landmark for deriving the widest points of the thalamus even when its boundaries are not identifiable. We augmented a generalized level-set framework with a shape prior and constraints derived from statistical shape models of the guitars; this framework was used to segment US images and measure the thalamic diameter. Our segmentation method achieved a higher mean Dice similarity coefficient, Hausdorff distance, specificity, and reduced contour leakage when compared to other well-established methods. The automatic thalamic diameter measurement had an interobserver variability of -0.56 ± 2.29 mm compared to manual measurement by an expert sonographer. Our method was capable of automatically estimating the thalamic diameter, with the measurement accuracy on par with clinical assessment. Our method can be used as part of computer-assisted screening tools that automatically measure the biometrics of the fetal thalamus; these biometrics are linked to neurodevelopmental outcomes.

  10. Serial measurements of serum human placental lactogen (hPL) and serial ultrasound examinations in the evaluation of fetal growth

    DEFF Research Database (Denmark)

    Sørensen, Steen; von Tabouillot, D; Schioler, V;

    2000-01-01

    weakly to intrauterine growth velocity (r=0.08). hPL-slope and intrauterine growth velocity independently predicted birth weight deviation. Heavy smoking which was stopped before the third trimester was not associated with low intrauterine growth velocity, but with a low hPL-slope. Preeclampsia...... and to the deviation in birth weight, but hPL seems to have a separate physiological significance, since it did not pick up when smoking was stopped and growth velocity was normalised and it did not at all detect the increased growth associated with preeclampsia.......Serial serum hPL measurements and serial ultrasound fetometry were compared in the evaluation of fetal growth by relating these two parameters to size at birth and to clinical factors known to influence size at birth. The data were from a prospective study of 1000 consecutive pregnant women...

  11. Design factors of intravascular dual frequency transducers for super-harmonic contrast imaging and acoustic angiography

    Science.gov (United States)

    Ma, Jianguo; Martin, K. Heath; Li, Yang; Dayton, Paul A.; Shung, K. Kirk; Zhou, Qifa; Jiang, Xiaoning

    2015-01-01

    Imaging of coronary vasa vasorum may lead to assessment of the vulnerable plaque development in diagnosis of atherosclerosis diseases. Dual frequency transducers capable of detection of microbubble super-harmonics have shown promise as a new contrast-enhanced intravascular ultrasound (CE-IVUS) platform with the capability of vasa vasorum imaging. Contrast-to-tissue ratio (CTR) in CE-IVUS imaging can be closely associated with the low frequency transmitter performance. In this paper, transducer designs encompassing different transducer layouts, transmitting frequencies, and transducer materials are compared for optimization of imaging performance. In the layout selection, the stacked configuration showed superior super-harmonic imaging compared with the interleaved configuration. In the transmitter frequency selection, a decrease in frequency from 6.5 MHz to 5 MHz resulted in an increase of CTR from 15 dB to 22 dB when receiving frequency was kept constant at 30 MHz. In the material selection, the dual frequency transducer with the lead magnesium niobate-lead titanate (PMN-PT) 1-3 composite transmitter yielded higher axial resolution compared to single crystal transmitters (70 μm compared to 150 μm pulse length). These comparisons provide guidelines for design of intravascular acoustic angiography transducers. PMID:25856384

  12. A Broadband Polyvinylidene Difluoride-Based Hydrophone with Integrated Readout Circuit for Intravascular Photoacoustic Imaging.

    Science.gov (United States)

    Daeichin, Verya; Chen, Chao; Ding, Qing; Wu, Min; Beurskens, Robert; Springeling, Geert; Noothout, Emile; Verweij, Martin D; van Dongen, Koen W A; Bosch, Johan G; van der Steen, Antonius F W; de Jong, Nico; Pertijs, Michiel; van Soest, Gijs

    2016-05-01

    Intravascular photoacoustic (IVPA) imaging can visualize the coronary atherosclerotic plaque composition on the basis of the optical absorption contrast. Most of the photoacoustic (PA) energy of human coronary plaque lipids was found to lie in the frequency band between 2 and 15 MHz requiring a very broadband transducer, especially if a combination with intravascular ultrasound is desired. We have developed a broadband polyvinylidene difluoride (PVDF) transducer (0.6 × 0.6 mm, 52 μm thick) with integrated electronics to match the low capacitance of such a small polyvinylidene difluoride element (<5 pF/mm(2)) with the high capacitive load of the long cable (∼100 pF/m). The new readout circuit provides an output voltage with a sensitivity of about 3.8 μV/Pa at 2.25 MHz. Its response is flat within 10 dB in the range 2 to 15 MHz. The root mean square (rms) output noise level is 259 μV over the entire bandwidth (1-20 MHz), resulting in a minimum detectable pressure of 30 Pa at 2.25 MHz.

  13. Lipid detection by intravascular photoacoustic imaging with flexible catheter at 20 fps (Conference Presentation)

    Science.gov (United States)

    Wu, Min; Daeichin, Verya; Springeling, Geert; van der Steen, Antonius F. W.; van Soest, Gijs

    2016-02-01

    Intravascular Photoacoustic (IVPA) imaging is a promising new technology to assess lipid content of coronary atherosclerotic plaque, an important determinant of the risk associated with the plaque triggering a heart attack. Clinical translation of IVPA imaging requires real-time image acquisition, which has been a technological challenge. In this work, we demonstrate a high-speed, dual-wavelength IVPA imaging system at 1.7 µm wavelength, operating with a flexible catheter of 1.2 mm outer diameter (including outer sheath). The catheter was custom designed and fabricated, and used a 40 MHz transducer for intravascular ultrasound (IVUS) and IVPA imaging. The optical excitation is provided by a dual OPO system, pumped by CW diode-pumped Q-switched Nd:YAG lasers, with a repetition rate of 5 kHz. Each OPO can be tuned to a custom wavelength between 1690 and 1750 nm; two wavelengths only are needed to discriminate between plaque lipids and adipose tissue. The pulse energy is about 80 µJ. We tested the imaging performance of the presented system in a polyvinyl-alcohol (PVA) vessel mimicking phantom and human coronary arteries ex vivo. IVPA identified lipid deposits inside atherosclerotic plaque, while IVUS showed tissue structure. We demonstrated IVPA imaging at a speed of 20 frames per second, with 250 A-scans per frame. This is significantly faster than previous IVPA imaging systems, and will enable the translation of IVPA imaging into clinical practice.

  14. [Disseminated intravascular coagulation: clinical and biological diagnosis].

    Science.gov (United States)

    Touaoussa, Aziz; El Youssi, Hind; El Hassani, Imane; Hanouf, Daham; El Bergui, Imane; Zoulati, Ghizlane; Amrani Hassani, Moncef

    2015-01-01

    Disseminated intravascular coagulation (DIC) is a syndrome characterized by the systemic activation of blood coagulation. Its pathophysiological mechanisms are complex and dependent on the underlying pathology, making the clinical and biological expression of quite variable DIC. Among the various biological parameters disrupted, most are not specific, and none of them allows in itself to make the diagnosis. All this does not facilitate the task of the practitioner for diagnosis of overt DIC, much less that of the non-overt DIC, early stage whose treatment would improve the prognosis. These considerations have led to develop scores, combining several parameters depending on their availability in daily practice, as well as their diagnostic relevance. Of all the scores, the ISTH (International society of thrombosis and hemostasis) remains the most used.

  15. Quinine-Induced Disseminated Intravascular Coagulation

    Directory of Open Access Journals (Sweden)

    Firas Abed

    2016-01-01

    Full Text Available Every drug comes with some side effect. It is the benefit/risk ratio that determines the medical use of the drug. Quinine, a known antimalarial drug, has been used for nocturnal leg cramps since the 1930s; it is associated with severe life-threatening hematological and cardiovascular side effects. Disseminated intravascular coagulation (DIC, albeit rare, is a known coagulopathy associated with Quinine. It is imperative to inquire about the Quinine intake in medication history in patients with coagulopathy, as most patients still consider it a harmless home remedy for nocturnal leg cramps. In this report, we present a case of coagulopathy in a middle-aged woman, who gave a history of taking Quinine for nocturnal leg cramps, as her home remedy. Early identification of the offending agent led to the diagnosis, prompt discontinuation of the medication, and complete recovery and prevented the future possibility of recurrence.

  16. Electromagnetic actuation methods for intravascular locomotive microrobot.

    Science.gov (United States)

    Cha, Kyoungrae; Jeong, Semi; Choi, Jongho; Qin, Lulu; Li, Jie; Park, Jongoh; Park, Sukho

    2010-01-01

    Heart diseases such as angina pectoris and myocardial infarction have been becoming the leading causes of death all over the world in recent years. The pharmacotherapy and the surgical operations have been executed for treating heart problems. The percutaneous coronary intervention (PCI) with catheter is frequently used for the treatment of coronary artery diseases, but the treatment of chronic total occlusion (CTO) is very difficult and challenging operation, since there is no efficient alternative therapy until now. For this reason, the microrobot to improve the intravascular treatment is one of the growing research areas. In this paper, various electromagnetic actuation (EMA) systems to supply driving power for the microrobot were proposed. The performance of the locomotion of microrobot in the 2D and 3D space were validated with in-vitro experiments and also the in-vivo tests were performed for demonstrating the movement of microrobot in the living rabbit.

  17. Ventricular metastasis resulting in disseminated intravascular coagulation

    Directory of Open Access Journals (Sweden)

    Davis Ian D

    2005-05-01

    Full Text Available Abstract Background Disseminated Intravascular Coagulation (DIC complicates up to 7% of malignancies, the commonest solid organ association being adenocarcinoma. Transitional Cell Carcinoma (TCC has rarely been associated with DIC. Case presentation A 74-year-old woman with TCC bladder and DIC was found to have a cardiac lesion suspicious for metastatic disease. The DIC improved with infusion of plasma and administration of Vitamin K, however the cardiac lesion was deemed inoperable and chemotherapy inappropriate; given the patients functional status. We postulate that direct activation of the coagulation cascade by the intraventricular metastasis probably triggered the coagulopathy in this patient. Conclusion Cardiac metastases should be considered in cancer patients with otherwise unexplained DIC. This may influence treatment choices.

  18. Elasticity-density and viscoelasticity-density relationships at the tibia mid-diaphysis assessed from resonant ultrasound spectroscopy measurements.

    Science.gov (United States)

    Bernard, Simon; Schneider, Joannes; Varga, Peter; Laugier, Pascal; Raum, Kay; Grimal, Quentin

    2016-02-01

    Cortical bone tissue is an anisotropic material characterized by typically five independent elastic coefficients (for transverse isotropy) governing shear and longitudinal deformations in the different anatomical directions. It is well established that the Young's modulus in the direction of the bone axis of long bones has a strong relationship with mass density. It is not clear, however, whether relationships of similar strength exist for the other elastic coefficients, for they have seldom been investigated, and the results available in the literature are contradictory. The objectives of the present work were to document the anisotropic elastic properties of cortical bone at the tibia mid-diaphysis and to elucidate their relationships with mass density. Resonant ultrasound spectroscopy (RUS) was used to measure the transverse isotropic stiffness tensor of 55 specimens from 19 donors. Except for Poisson's ratios and the non-diagonal stiffness coefficient, strong linear correlations between the different elastic coefficients (0.7 tibia. RUS also measures the viscous part of the stiffness tensor. An anisotropy ratio close to two was found for damping coefficients. Damping increased as the mass density decreased. The data suggest that a relatively accurate estimation of all the mid-tibia elastic coefficients can be derived from mass density. This is of particular interest (1) to design organ-scale bone models in which elastic coefficients are mapped according to Hounsfield values from computed tomography scans as a surrogate for mass density and (2) to model ultrasound propagation at the mid-tibia, which is an important site for the in vivo assessment of bone status with axial transmission techniques.

  19. Prostate Ultrasound

    Medline Plus

    Full Text Available ... as detailed as with the transrectal probe. An MRI of the pelvis may be obtained as an ... Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate Biopsy Images related to Ultrasound - Prostate ...

  20. Prostate Ultrasound

    Medline Plus

    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning may be able to give a ...