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Sample records for intravascular ultrasound ivus

  1. Multi-Frequency Intravascular Ultrasound (IVUS) Imaging

    PubMed Central

    Ma, Teng; Yu, Mingyue; Chen, Zeyu; Fei, Chunlong; Shung, K. Kirk; Zhou, Qifa

    2015-01-01

    Acute coronary syndrome (ACS) is frequently associated with the sudden rupture of a vulnerable atherosclerotic plaque within the coronary artery. Several unique physiological features, including a thin fibrous cap accompanied by a necrotic lipid core, are the targeted indicators for identifying the vulnerable plaques. Intravascular ultrasound (IVUS), a catheter-based imaging technology, has been routinely performed in clinics for more than 20 years to describe the morphology of the coronary artery and guide percutaneous coronary interventions. However, conventional IVUS cannot facilitate the risk assessment of ACS because of its intrinsic limitations, such as insufficient resolution. Renovation of the IVUS technology is essentially needed to overcome the limitations and enhance the coronary artery characterization. In this paper, a multi-frequency intravascular ultrasound (IVUS) imaging system was developed by incorporating a higher frequency IVUS transducer (80 to 150 MHz) with the conventional IVUS (30–50 MHz) system. The newly developed system maintains the advantage of deeply penetrating imaging with the conventional IVUS, while offering an improved higher resolution image with IVUS at a higher frequency. The prototyped multi-frequency catheter has a clinically compatible size of 0.95 mm and a favorable capability of automated image co-registration. In vitro human coronary artery imaging has demonstrated the feasibility and superiority of the multi-frequency IVUS imaging system to deliver a more comprehensive visualization of the coronary artery. This ultrasonic-only intravascular imaging technique, based on a moderate refinement of the conventional IVUS system, is not only cost-effective from the perspective of manufacturing and clinical practice, but also holds the promise of future translation into clinical benefits. PMID:25585394

  2. Intravascular ultrasound

    MedlinePlus

    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 ...

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

    PubMed Central

    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

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

    PubMed

    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. PMID:24960706

  5. Diagnostic accuracy of integrated intravascular ultrasound and optical coherence tomography (IVUS-OCT) system for coronary plaque characterization

    NASA Astrophysics Data System (ADS)

    Li, Jiawen; Ma, Teng; Mohar, Dilbahar; Correa, Adrian; Minami, Hataka; Jing, Joseph; Zhou, Qifa; Patel, Pranav M.; Chen, Zhongping

    2014-03-01

    Intravascular ultrasound (IVUS) imaging and optical coherence tomography (OCT), two commonly used intracoronary imaging modalities, play important roles in plaque evaluation. The combined use of IVUS (to visualize the entire plaque volume) and OCT (to quantify the thickness of the plaque cap, if any) is hypothesized to increase plaque diagnostic accuracy. Our group has developed a fully-integrated dual-modality IVUS-OCT imaging system and 3.6F catheter for simultaneous IVUS-OCT imaging with a high resolution and deep penetration depth. However, the diagnostic accuracy of an integrated IVUS-OCT system has not been investigated. In this study, we imaged 175 coronary artery sites (241 regions of interest) from 20 cadavers using our previous reported integrated IVUS-OCT system. IVUS-OCT images were read by two skilled interventional cardiologists. Each region of interest was classified as either calcification, lipid pool or fibrosis. Comparing the diagnosis by cardiologists using IVUSOCT images with the diagnosis by the pathologist, we calculated the sensitivity and specificity for characterization of calcification, lipid pool or fibrosis with this integrated system. In vitro imaging of cadaver coronary specimens demonstrated the complementary nature of these two modalities for plaques classification. A higher accuracy was shown than using a single modality alone.

  6. Using ChromaFlo intra-vascular ultrasound (IVUS) to analyze adventitial vasa vasorum distribution: considerations and recommendations

    NASA Astrophysics Data System (ADS)

    Redwood, Abena; Holmes, David R., III; Robb, Richard

    2006-03-01

    The adventitia and outer media of large blood vessels are supplied with nutrients by microscopic blood vessels called vasa vasorum. While vasa vasorum have been implicated in a number of diseases including atherosclerosis, knowledge of their functional anatomy and specific role in these diseases has been hindered due to the small size of the vasa vasorum, and difficulty in accessing them. Micro-CT and histological methods have been used in ex-vivo animal studies of the vasa vasorum, but these techniques are limited by their inability to be used for in-vivo investigation. As such, there is very little in-vivo human data available. Intra-vascular ultrasound can acquire high-resolution anatomic images of coronary vessels. ChromaFlo IVUS has been used to identify blood flow in vessel lumens and has exciting prospect for in-vivo studies of vasa vasorum functional anatomy. In this study, ChromaFlo IVUS images of the human mid-left anterior descending coronary artery (LAD) were segmented to analyze the distribution of adventitial vasa vasorum proximal to intimal plaque. Previous animal studies suggest that formation of intimal plaque is accompanied by increased density of adventitial vasa vasorum. The data collected with ChromaFlo ultrasound is inconsistent with the current literature. While IVUS has the fidelity to acquire high-resolution US images of the coronary arteries, ChromaFlo lacks the necessary resolving power to differentiate the vasa vasorum. Further study of IVUS and other imaging methods on a large cohort will provide the basis for future in-vivo analysis of coronary disease.

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

    PubMed

    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

  8. Intravascular Ultrasound

    MedlinePlus

    ... and a procedure called cardiac catheterization . IVUS uses sound waves to produce an image of the coronary arteries and to see their condition. The sound waves travel through a tube called a catheter. The ...

  9. Intravascular Ultrasound and Virtual Histology of Basilar Artery Atherosclerotic Lesion

    PubMed Central

    López-Rueda, A.; González García, A.; Aguilar Pérez, M.; Gutiérrez Jarrín, R.K.; Mayol Deyá, A.

    2011-01-01

    Summary To our knowledge, this paper presents the first intravascular ultrasound and virtual histology (IVUS-VH) study in the basilar artery. IVUS-VH serves to characterize and determine the extension of the plaque and we also to check stent placement. PMID:22192552

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

    PubMed

    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.

  11. 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

    NASA Astrophysics Data System (ADS)

    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.

  12. An Open System for Intravascular Ultrasound Imaging

    PubMed Central

    Qiu, Weibao; Chen, Yan; Li, Xiang; Yu, Yanyan; Cheng, Wang Fai; Tsang, Fu Keung; Zhou, Qifa; Shung, K. Kirk; Dai, Jiyan; Sun, Lei

    2013-01-01

    Visualization of the blood vessels can provide valuable morphological information for diagnosis and therapy strategies for cardiovascular disease. Intravascular ultrasound (IVUS) is able to delineate internal structures of vessel wall with fine spatial resolution. However, the developed IVUS is insufficient to identify the fibrous cap thickness and tissue composition of atherosclerotic lesions. Novel imaging strategies have been proposed, such as increasing the center frequency of ultrasound or using a modulated excitation technique to improve the accuracy of diagnosis. Dual-mode tomography combining IVUS with optical tomography has also been developed to determine tissue morphology and characteristics. The implementation of these new imaging methods requires an open system that allows users to customize the system for various studies. This paper presents the development of an IVUS system that has open structures to support various imaging strategies. The system design is based on electronic components and printed circuit board, and provides reconfigurable hardware implementation, programmable image processing algorithms, flexible imaging control, and raw RF data acquisition. In addition, the proposed IVUS system utilized a miniaturized ultrasound transducer constructed using PMN-PT single crystal for better piezoelectric constant and electromechanical coupling coefficient than traditional lead zirconate titanate (PZT) ceramics. Testing results showed that the IVUS system could offer a minimum detectable signal of 25 μV, allowing a 51 dB dynamic range at 47 dB gain, with a frequency range from 20 to 80 MHz. Finally, phantom imaging, in vitro IVUS vessel imaging, and multimodality imaging with photoacoustics were conducted to demonstrate the performance of the open system. PMID:23143570

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Design, construction, and validation of a multimodal intravascular diagnostic catheter combining IVUS and fluorescence lifetime spectroscopy detection channels

    NASA Astrophysics Data System (ADS)

    Bec, Julien; Xie, Hongtao; Yankelevich, Diego; Zhou, Feifei; Sun, Yang; Ghata, Narugopal; Aldredge, Ralph; Marcu, Laura

    2011-03-01

    We report the development and validation of an intravascular rotary catheter that enables bi-modal interrogation of arterial pathologies based on fast-frame time-resolved fluorescence spectroscopy (TRFS) and intravascular ultrasound (IVUS). The catheter is based on a parallel design that allows for independent rotation of the ultrasonic and optical channels within an 8 Fr outer diameter catheter sheath and integrates a low volume flushing channel for blood removal in the optical pathways. In current configuration, the two channels consist of a) a standard 8 Fr IVUS catheter with single element transducer (15 MHz) and b) a side-viewing UV-grade silica/silica fiber optic (400 μm core). The catheter is terminated by a small (0.82 mm internal diameter) polyimide tube to keep the fiber stable within the sheath. To clear the field of view from blood, a saline solution can be flushed in a sheath channel, concentric with the fiber optic, through the tube and in a radial opening aligned with the fiber's optical beam. The flushing function was optimized with a computational fluid dynamics (CFD) model pursued in a parallel study. The ability of the catheter to operate in intraluminal setting in blood flow, the effect of probe-to-tissue distance on optical signal and ability to generate co-registered TRFS and IVUS data were demonstrated in blood vessel phantoms. Current results demonstrate the feasibility of the described catheter for parallel interrogation of vessel walls based on TRFS and IVUS and to generate robust TRFS data. These results facilitate further development of a bi-modal TRFS-IVUS technique for intravascular diagnosis of atherosclerotic cardiovascular diseases including vulnerable plaques.

  15. Cardiac phase detection in intravascular ultrasound images

    NASA Astrophysics Data System (ADS)

    Matsumoto, Monica M. S.; Lemos, Pedro Alves; Yoneyama, Takashi; Furuie, Sergio Shiguemi

    2008-03-01

    Image gating is related to image modalities that involve quasi-periodic moving organs. Therefore, during intravascular ultrasound (IVUS) examination, there is cardiac movement interference. In this paper, we aim to obtain IVUS gated images based on the images themselves. This would allow the reconstruction of 3D coronaries with temporal accuracy for any cardiac phase, which is an advantage over the ECG-gated acquisition that shows a single one. It is also important for retrospective studies, as in existing IVUS databases there are no additional reference signals (ECG). From the images, we calculated signals based on average intensity (AI), and, from consecutive frames, average intensity difference (AID), cross-correlation coefficient (CC) and mutual information (MI). The process includes a wavelet-based filter step and ascendant zero-cross detection in order to obtain the phase information. Firstly, we tested 90 simulated sequences with 1025 frames each. Our method was able to achieve more than 95.0% of true positives and less than 2.3% of false positives ratio, for all signals. Afterwards, we tested in a real examination, with 897 frames and ECG as gold-standard. We achieved 97.4% of true positives (CC and MI), and 2.5% of false positives. For future works, methodology should be tested in wider range of IVUS examinations.

  16. Integrated intravascular optical coherence tomography (OCT) - ultrasound (US) imaging system

    NASA Astrophysics Data System (ADS)

    Yin, Jiechen; Yang, Hao-Chung; Li, Xiang; Zhou, Qifa; Hu, Changhong; Zhang, Jun; Shung, K. Kirk; Chen, Zhongping

    2010-02-01

    Optical coherence tomography (OCT) and intravascular ultrasound (IVUS) are considered two complementary imaging techniques in the detection and diagnosis of atherosclerosis. OCT permits visualization of micron-scale features of atherosclerosis plaque, and IVUS offers full imaging depth of vessel wall. Under the guidance of IVUS, minimal amount of flushing agent will be needed to obtain OCT imaging of the interested area. We report on a dual-modality optical coherence tomography (OCT) - ultrasound (US) system for intravascular imaging. To the best of our knowledge, we have developed the first integrated OCT-US probe that combines OCT optical components with an ultrasound transducer. The OCT optical components mainly consist of a single mode fiber, a gradient index (GRIN) lens for light beam focusing, and a right-angled prism for reflecting light into biological tissue. A 40MHz PZT-5H side-viewing ultrasound transducer was fabricated to obtain the ultrasound image. These components were integrated into a single probe, enabling both OCT and ultrasound imaging at the same time. In vitro OCT and ultrasound images of a rabbit aorta were obtained using this dual-modality imaging system. This study demonstrates the feasibility of an OCT-US system for intravascular imaging which is expected to have a prominent impact on early detection and characterization of atherosclerosis.

  17. Successful Intravascular Ultrasound-Guided Transradial Coronary Intervention with a 4Fr Guiding Catheter

    PubMed Central

    Sadamatsu, Kenji

    2016-01-01

    Minimizing the catheter size can reduce vascular access complications and contrast dye usage in coronary angiography. The small diameter of the 4Fr guiding catheter has limited the use of several angioplasty devices such as intravascular ultrasound (IVUS) in the past. However, the combination of a novel IVUS catheter and a 0.010 guidewire makes it possible to perform IVUS-guided percutaneous coronary intervention (PCI) with a 4Fr guiding catheter. We herein report the case of a 51-year-old man with silent myocardial ischemia who underwent IVUS-guided transradial PCI with a 4Fr guiding catheter. PMID:27672455

  18. Successful Intravascular Ultrasound-Guided Transradial Coronary Intervention with a 4Fr Guiding Catheter.

    PubMed

    Nakano, Yasuhiro; Sadamatsu, Kenji

    2016-01-01

    Minimizing the catheter size can reduce vascular access complications and contrast dye usage in coronary angiography. The small diameter of the 4Fr guiding catheter has limited the use of several angioplasty devices such as intravascular ultrasound (IVUS) in the past. However, the combination of a novel IVUS catheter and a 0.010 guidewire makes it possible to perform IVUS-guided percutaneous coronary intervention (PCI) with a 4Fr guiding catheter. We herein report the case of a 51-year-old man with silent myocardial ischemia who underwent IVUS-guided transradial PCI with a 4Fr guiding catheter. PMID:27672455

  19. Zero Contrast Coronary Intervention Using Intravascular Ultrasound Guidance in a Patient with Allergy to Contrast Medium.

    PubMed

    Nagaoka, Masakazu; Tsumuraya, Naoko; Nie, Masaki; Ikari, Yuji

    2016-01-01

    The occurrence of allergy to iodinated contrast in certain patients may prevent the use of percutaneous coronary intervention (PCI) in such cases. We present a 53-year-old male with a history of allergic reaction to iodinated contrast who successfully underwent intravascular ultrasound (IVUS) guided PCI. Stent size was determined based on IVUS. After PCI, stent expansion and a lack of edge dissection or incomplete apposition were confirmed by IVUS. Thus, PCI without contrast injection under IVUS may be feasible in selected patients with allergy to iodinated contrast. PMID:27628609

  20. Successful Intravascular Ultrasound-Guided Transradial Coronary Intervention with a 4Fr Guiding Catheter

    PubMed Central

    Sadamatsu, Kenji

    2016-01-01

    Minimizing the catheter size can reduce vascular access complications and contrast dye usage in coronary angiography. The small diameter of the 4Fr guiding catheter has limited the use of several angioplasty devices such as intravascular ultrasound (IVUS) in the past. However, the combination of a novel IVUS catheter and a 0.010 guidewire makes it possible to perform IVUS-guided percutaneous coronary intervention (PCI) with a 4Fr guiding catheter. We herein report the case of a 51-year-old man with silent myocardial ischemia who underwent IVUS-guided transradial PCI with a 4Fr guiding catheter.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  3. Rotational multispectral fluorescence lifetime imaging and intravascular ultrasound: bimodal system for intravascular applications

    PubMed Central

    Ma, Dinglong; Bec, Julien; Yankelevich, Diego R.; Gorpas, Dimitris; Fatakdawala, Hussain; Marcu, Laura

    2014-01-01

    Abstract. We report the development and validation of a hybrid intravascular diagnostic system combining multispectral fluorescence lifetime imaging (FLIm) and intravascular ultrasound (IVUS) for cardiovascular imaging applications. A prototype FLIm system based on fluorescence pulse sampling technique providing information on artery biochemical composition was integrated with a commercial IVUS system providing information on artery morphology. A customized 3-Fr bimodal catheter combining a rotational side-view fiberoptic and a 40-MHz IVUS transducer was constructed for sequential helical scanning (rotation and pullback) of tubular structures. Validation of this bimodal approach was conducted in pig heart coronary arteries. Spatial resolution, fluorescence detection efficiency, pulse broadening effect, and lifetime measurement variability of the FLIm system were systematically evaluated. Current results show that this system is capable of temporarily resolving the fluorescence emission simultaneously in multiple spectral channels in a single pullback sequence. Accurate measurements of fluorescence decay characteristics from arterial segments can be obtained rapidly (e.g., 20 mm in 5 s), and accurate co-registration of fluorescence and ultrasound features can be achieved. The current finding demonstrates the compatibility of FLIm instrumentation with in vivo clinical investigations and its potential to complement conventional IVUS during catheterization procedures. PMID:24898604

  4. Intravascular ultrasound and optical coherence tomography imaging of coronary atherosclerosis.

    PubMed

    Costopoulos, Charis; Brown, Adam J; Teng, Zhongzhao; Hoole, Stephen P; West, Nick E J; Samady, Habib; Bennett, Martin R

    2016-01-01

    Invasive imaging modalities, in particular intravascular ultrasound (IVUS) and optical coherence tomography (OCT), have become established tools for the in vivo study of coronary atherosclerosis. Their use in clinical studies has confirmed histopathological observations that certain important plaque features, such as thin fibrous caps and large lipid cores, are associated with plaque rupture, the precipitating event for the majority of myocardial infarctions. Serial imaging studies have also successfully been used for the evaluation of potential disease modifying pharmacological agents. Recent prospective IVUS studies have confirmed specific baseline imaging features associated with subsequent adverse clinical outcomes, although absolute event rates were too low for clinical utility. Development of hybrid IVUS-OCT imaging or integration of novel techniques, including near-infrared spectroscopy, plaque structural and endothelial shear stress, have great potential to improve our current ability to identify and stratify atheromatous plaques at risk of rupture.

  5. Integrated intravascular ultrasound and optical-resolution photoacoustic microscopy with a 1-mm-diameter catheter

    NASA Astrophysics Data System (ADS)

    Bai, Xiaosong; Gong, Xiaojing; Lin, Riqiang; Hau, William; Song, Liang

    2014-03-01

    Intravascular ultrasound (IVUS) plays a vital role in assessing the severity of atherosclerosis and has greatly enriched our knowledge on atherosclerotic plaques. However, it mainly reveals the structural information of plaques. In contrast, spectroscopic and molecular photoacoustic imaging can potentially improve plaque composition identification, inflammation detection, and ultimately the stratification of plaque vulnerability and risk. In this work, we developed an integrated intravascular ultrasound and optical-resolution photoacoustic microscopy (IVUS-PAM) system with a single catheter as small as 1 mm in diameter, comparable to that of existing clinical IVUS catheters. In addition, by using a GRIN lens to focus the excitation laser pulse, the system provides an optical-diffraction limited photoacoustic lateral resolution as fine as 19.6 micrometers, ~10-fold finer than that of conventional intravascular photoacoustic imaging and existing IVUS technology. The system employs a custom-made miniaturized single-element ultrasonic transducer with a dimension of ~0.5 mm, a centre frequency of ~40 MHz, and a fractional bandwidth of ~60%. The IVUS-PAM can simultaneously acquire co-registered IVUS images with an axial resolution of ~40 micrometers and a lateral resolution of ~200 micrometers. In the future, IVUS-PAM may open up new opportunities for improved high-resolution vulnerable plaque imaging and image-guided stent deployment.

  6. A novel method of coronary stent sizing using intravascular ultrasound: Safety and clinical outcomes

    PubMed Central

    Wong, Christopher B; Hansen, Norman D

    2009-01-01

    OBJECTIVES The use of intravascular ultrasound (IVUS) in guiding coronary stenting has increased in recent years. The feasibility, safety and clinical outcomes of a novel method of sizing coronary stents using IVUS have not been established. The main end points of the current study are the incidence of acute and short-term complications, and the need for target vessel revascularization at six months. METHODS Eighty-six patients underwent coronary stenting using IVUS imaging during the procedure. The optimal size of the stents was determined by using a novel method (the ‘aggressive IVUS method’), ie, measuring the media-to-media dimensions of the coronary vessels at the site of the lesions using IVUS. A six-month follow-up chart review was performed following the initial stenting. RESULTS At six months, there were two noncardiac deaths in the group. There were no acute, subacute or late stent thromboses. Target vessel revascularization and major adverse cardiac event rates remained low – at 5.8% and 9.3%, respectively. The mean (± SD) IVUS-derived coronary stent size (3.89±0.98 mm) using the aggressive IVUS method was significantly different from the mean IVUS-derived coronary stent size (3.46±0.96 mm) using the ‘traditional IVUS method’. CONCLUSION Aggressive sizing of the coronary stents by IVUS guidance is feasible and safe, and is associated with a favourable clinical outcome. PMID:22477471

  7. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement

    PubMed Central

    Hussain, Ahmad S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates. PMID:27672529

  8. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement

    PubMed Central

    Hussain, Ahmad S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates.

  9. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement.

    PubMed

    Hussain, Ahmad S; Hussain, Namath S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates. PMID:27672529

  10. [Current status of intravascular ultrasound in interventional cardiology].

    PubMed

    Kovárník, Tomáš

    2014-12-01

    Although intravascular ultrasound has been used for decades, its common application in catheterization centres during coronary interventions is very rare and merely reaches few percents. The reason is the lack of randomized trials of its use and often few experiences in evaluation of ultrasound findings. Data based on meta-analysis of observational studies clearly demonstrated the positive effect on the most important parameters for the treatment of patients with ischemic heart disease, such as mortality and incidence of myocardial infarction after coronary interventions. Therefore, according to the latest guidelines for myocardial revascularization of the European Society of Cardiology is level of recommendation in category IIa for the use of intravascular ultrasound. IVUS continues to be an important part of new investigation methods which try to better describe coronary atherosclerosis. Particularly, it is the method NIRS (near-infrared spectroscopy) and other new methods of evaluating the composition and mechanical properties of plaque. These facts suggest that IVUS maintains its contribution in time of optical coherence tomography (OCT) and the emphasis put on the functional assessment of coronary stenoses.Key words: coronary atherosclerosis - intravascular ultrasound - percutaneous coronary intervention. PMID:25692833

  11. Design, construction, and validation of a rotary multifunctional intravascular diagnostic catheter combining multispectral fluorescence lifetime imaging and intravascular ultrasound.

    PubMed

    Bec, Julien; Xie, Hongtao; Yankelevich, Diego R; Zhou, Feifei; Sun, Yang; Ghata, Narugopal; Aldredge, Ralph; Marcu, Laura

    2012-10-01

    We report the development and validation of an intravascular rotary catheter for bimodal interrogation of arterial pathologies. This is based on a point-spectroscopy scanning time-resolved fluorescence spectroscopy technique enabling reconstruction of fluorescence lifetime images (FLIm) and providing information on arterial intima composition and intravascular ultrasound (IVUS) providing information on arterial wall morphology. The catheter design allows for independent rotation of the ultrasonic and optical channels within an 8 Fr outer diameter catheter sheath and integrates a low volume flushing channel for blood removal in the optical pathways. In the current configuration, the two channels consist of (a) a standard 3 Fr IVUS catheter with single element transducer (40 MHz) and (b) a side-viewing fiber optic (400 μm core). Experiments conducted in tissue phantoms showed the ability of the catheter to operate in an intraluminal setting and to generate coregistered FLIm and IVUS in one pull-back scan. Current results demonstrate the feasibility of the catheter for simultaneous bimodal interrogation of arterial lumen and for generation of robust fluorescence lifetime data under IVUS guidance. These results facilitate further development of a FLIm-IVUS technique for intravascular diagnosis of atherosclerotic cardiovascular diseases including vulnerable plaques.

  12. Design, construction, and validation of a rotary multifunctional intravascular diagnostic catheter combining multispectral fluorescence lifetime imaging and intravascular ultrasound

    NASA Astrophysics Data System (ADS)

    Bec, Julien; Xie, Hongtao; Yankelevich, Diego R.; Zhou, Feifei; Sun, Yang; Ghata, Narugopal; Aldredge, Ralph; Marcu, Laura

    2012-10-01

    We report the development and validation of an intravascular rotary catheter for bimodal interrogation of arterial pathologies. This is based on a point-spectroscopy scanning time-resolved fluorescence spectroscopy technique enabling reconstruction of fluorescence lifetime images (FLIm) and providing information on arterial intima composition and intravascular ultrasound (IVUS) providing information on arterial wall morphology. The catheter design allows for independent rotation of the ultrasonic and optical channels within an 8 Fr outer diameter catheter sheath and integrates a low volume flushing channel for blood removal in the optical pathways. In the current configuration, the two channels consist of (a) a standard 3 Fr IVUS catheter with single element transducer (40 MHz) and (b) a side-viewing fiber optic (400 μm core). Experiments conducted in tissue phantoms showed the ability of the catheter to operate in an intraluminal setting and to generate coregistered FLIm and IVUS in one pull-back scan. Current results demonstrate the feasibility of the catheter for simultaneous bimodal interrogation of arterial lumen and for generation of robust fluorescence lifetime data under IVUS guidance. These results facilitate further development of a FLIm-IVUS technique for intravascular diagnosis of atherosclerotic cardiovascular diseases including vulnerable plaques.

  13. Determination of Stent Stenosis: An In Vivo Experimental Comparison of Intravascular Ultrasound and Angiography with Histology

    SciTech Connect

    Schuermann, Karl; Vorwerk, Dierk; Uppenkamp, Robert; Klosterhalfen, Bernd; Buecker, Arno; Guenther, Rolf W.

    1998-05-15

    Purpose: To compare intravascular ultrasound (IVUS) and angiography with histology in determining the degree of stent stenosis in an in vivo experiment. Methods: In 16 sheep, a total of 64 stents were implanted into the external iliac arteries. Two stents were inserted on either side. Patency was followed by angiography and IVUS. Four types of stent were used: two Dacron-covered (Cragg Endopro and heparinized Cragg Endopro) and two non-covered (Cragg and Memotherm stents). Eight animals were killed after 1 month, eight others after 6 months. Histological sections were prepared from the stented vessels. Measurements of the patent and total stent diameters determined by IVUS, angiography, and histology were compared. Results: Correlation between IVUS and angiography was 0.75, between IVUS and histology 0.77, and between angiography and histology 0.85. A mean stent stenosis of 17 {+-} 11% (range 0-51%) was found on angiography, of 10 {+-} 11% (0-46%) on IVUS, and of 20 {+-} 11% (4%-49%) on histology. In comparison with histology, IVUS underestimated the degree of stenosis by 10 {+-} 8%, and angiography underestimated it by 3 {+-} 6%. Resolution of IVUS was calculated to be about 0.35 mm and that of angiography to be about 0.15 mm. Conclusion: Under experimental conditions, IVUS was not superior to angiography in determining the degree of stent stenosis in long-segment stenoses of iliac artery stents, when measurements were correlated with histology. Angiography is sufficient for following the patency of iliac artery stents.

  14. Quantitative blood speed imaging with intravascular ultrasound.

    PubMed

    Crowe, J R; O'Donnell, M

    2001-03-01

    Previously, we presented a method of real-time arterial color flow imaging using an intravascular ultrasound (IVUS) imaging system, where real-time RF A-scans were processed with an FIR (finite-impulse response) filter bank to estimate relative blood speed. Although qualitative flow measurements are clinically valuable, realizing the full potential of blood flow imaging requires quantitative flow speed and volume measurements in real time. Unfortunately, the rate of RF echo-to-echo decorrelation is not directly related to scatterer speed in a side-looking IVUS system because the elevational extent of the imaging slice varies with range. Consequently, flow imaging methods using any type of decorrelation processing to estimate blood speed without accounting for spatial variation of the radiation pattern will have estimation errors that prohibit accurate comparison of speed estimates from different depths. The FIR filter bank approach measures the rate of change of the ultrasound signal by estimating the slow-time spectrum of RF echoes. A filter bank of M bandpass filters is applied in parallel to estimate M components of the slow-time DFT (discrete Fourier transform). The relationship between the slow-time spectrum, aperture diffraction pattern, and scatterer speed is derived for a simplified target. Because the ultimate goal of this work is to make quantitative speed measurements, we present a method to map slow time spectral characteristics to a quantitative estimate. Results of the speed estimator are shown for a simulated circumferential catheter array insonifying blood moving uniformly past the array (i.e., plug flow) and blood moving with a parabolic profile (i.e., laminar flow). PMID:11370361

  15. A physics-based intravascular ultrasound image reconstruction method for lumen segmentation.

    PubMed

    Mendizabal-Ruiz, Gerardo; Kakadiaris, Ioannis A

    2016-08-01

    Intravascular ultrasound (IVUS) refers to the medical imaging technique consisting of a miniaturized ultrasound transducer located at the tip of a catheter that can be introduced in the blood vessels providing high-resolution, cross-sectional images of their interior. Current methods for the generation of an IVUS image reconstruction from radio frequency (RF) data do not account for the physics involved in the interaction between the IVUS ultrasound signal and the tissues of the vessel. In this paper, we present a novel method to generate an IVUS image reconstruction based on the use of a scattering model that considers the tissues of the vessel as a distribution of three-dimensional point scatterers. We evaluated the impact of employing the proposed IVUS image reconstruction method in the segmentation of the lumen/wall interface on 40MHz IVUS data using an existing automatic lumen segmentation method. We compared the results with those obtained using the B-mode reconstruction on 600 randomly selected frames from twelve pullback sequences acquired from rabbit aortas and different arteries of swine. Our results indicate the feasibility of employing the proposed IVUS image reconstruction for the segmentation of the lumen.

  16. A physics-based intravascular ultrasound image reconstruction method for lumen segmentation.

    PubMed

    Mendizabal-Ruiz, Gerardo; Kakadiaris, Ioannis A

    2016-08-01

    Intravascular ultrasound (IVUS) refers to the medical imaging technique consisting of a miniaturized ultrasound transducer located at the tip of a catheter that can be introduced in the blood vessels providing high-resolution, cross-sectional images of their interior. Current methods for the generation of an IVUS image reconstruction from radio frequency (RF) data do not account for the physics involved in the interaction between the IVUS ultrasound signal and the tissues of the vessel. In this paper, we present a novel method to generate an IVUS image reconstruction based on the use of a scattering model that considers the tissues of the vessel as a distribution of three-dimensional point scatterers. We evaluated the impact of employing the proposed IVUS image reconstruction method in the segmentation of the lumen/wall interface on 40MHz IVUS data using an existing automatic lumen segmentation method. We compared the results with those obtained using the B-mode reconstruction on 600 randomly selected frames from twelve pullback sequences acquired from rabbit aortas and different arteries of swine. Our results indicate the feasibility of employing the proposed IVUS image reconstruction for the segmentation of the lumen. PMID:27235803

  17. Functional assessment of coronary artery disease by intravascular ultrasound and computational fluid dynamics simulation.

    PubMed

    Carrizo, Sebastián; Xie, Xinzhou; Peinado-Peinado, Rafael; Sánchez-Recalde, Angel; Jiménez-Valero, Santiago; Galeote-Garcia, Guillermo; Moreno, Raúl

    2014-10-01

    Clinical trials have shown that functional assessment of coronary stenosis by fractional flow reserve (FFR) improves clinical outcomes. Intravascular ultrasound (IVUS) complements conventional angiography, and is a powerful tool to assess atherosclerotic plaques and to guide percutaneous coronary intervention (PCI). Computational fluid dynamics (CFD) simulation represents a novel method for the functional assessment of coronary flow. A CFD simulation can be calculated from the data normally acquired by IVUS images. A case of coronary heart disease studied with FFR and IVUS, before and after PCI, is presented. A three-dimensional model was constructed based on IVUS images, to which CFD was applied. A discussion of the literature concerning the clinical utility of CFD simulation is provided. PMID:25441999

  18. Functional assessment of coronary artery disease by intravascular ultrasound and computational fluid dynamics simulation.

    PubMed

    Carrizo, Sebastián; Xie, Xinzhou; Peinado-Peinado, Rafael; Sánchez-Recalde, Angel; Jiménez-Valero, Santiago; Galeote-Garcia, Guillermo; Moreno, Raúl

    2014-10-01

    Clinical trials have shown that functional assessment of coronary stenosis by fractional flow reserve (FFR) improves clinical outcomes. Intravascular ultrasound (IVUS) complements conventional angiography, and is a powerful tool to assess atherosclerotic plaques and to guide percutaneous coronary intervention (PCI). Computational fluid dynamics (CFD) simulation represents a novel method for the functional assessment of coronary flow. A CFD simulation can be calculated from the data normally acquired by IVUS images. A case of coronary heart disease studied with FFR and IVUS, before and after PCI, is presented. A three-dimensional model was constructed based on IVUS images, to which CFD was applied. A discussion of the literature concerning the clinical utility of CFD simulation is provided.

  19. Fluorescence Lifetime Imaging and Intravascular Ultrasound: Co-Registration Study Using Ex Vivo Human Coronaries

    PubMed Central

    Gorpas, Dimitris; Fatakdawala, Hussain; Bec, Julien; Ma, Dinglong; Yankelevich, Diego R.; Qi, Jinyi

    2015-01-01

    Fluorescence lifetime imaging (FLIM) has demonstrated potential for robust assessment of atherosclerotic plaques biochemical composition and for complementing conventional intravascular ultrasound (IVUS), which provides information on plaque morphology. The success of such a bi-modal imaging modality depends on accurate segmentation of the IVUS images and proper angular registration between these two modalities. This paper reports a novel IVUS segmentation methodology addressing this issue. The image preprocessing consisted of denoising, using the Wiener filter, followed by image smoothing, implemented through the application of the alternating sequential filter on the edge separability metric images. Extraction of the lumen/intima and media/adventitia boundaries was achieved by tracing the gray-scale peaks over the A-lines of the IVUS preprocessed images. Cubic spline interpolation, in both cross-sectional and longitudinal directions, ensured boundary smoothness and continuity. The detection of the guide-wire artifact in both modalities is used for angular registration. Intraluminal studies were conducted in 13 ex vivo segments of human coronaries. The IVUS segmentation accuracy was assessed against independent manual tracings, providing 91.82% sensitivity and 97.55% specificity. The proposed methodology makes the bi-modal FLIM and IVUS approach feasible for comprehensive intravascular diagnosis by providing co-registered biochemical and morphological information of atherosclerotic plaques. PMID:25163056

  20. Integrated IVUS-OCT Imaging for Atherosclerotic Plaque Characterization

    PubMed Central

    Li, Xiang; Li, Jiawen; Jing, Joe; Ma, Teng; Liang, Shanshan; Zhang, Jun; Mohar, Dilbahar; Raney, Aidan; Mahon, Sari; Brenner, Matthew; Patel, Pranav; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping

    2014-01-01

    For the diagnosis of atherosclerosis, biomedical imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed. The combined use of IVUS and OCT is hypothesized to remarkably increase diagnostic accuracy of vulnerable plaques. We have developed an integrated IVUS-OCT imaging apparatus, which includes the integrated catheter, motor drive unit, and imaging system. The dual-function imaging catheter has the same diameter of current clinical standard. The imaging system is capable for simultaneous IVUS and OCT imaging in real time. Ex vivo and in vivo experiments on rabbits with atherosclerosis were conducted to demonstrate the feasibility and superiority of the integrated intravascular imaging modality. PMID:24771992

  1. Integrated IVUS-OCT Imaging for Atherosclerotic Plaque Characterization.

    PubMed

    Li, Xiang; Li, Jiawen; Jing, Joe; Ma, Teng; Liang, Shanshan; Zhang, Jun; Mohar, Dilbahar; Raney, Aidan; Mahon, Sari; Brenner, Matthew; Patel, Pranav; Shung, K Kirk; Zhou, Qifa; Chen, Zhongping

    2014-03-01

    For the diagnosis of atherosclerosis, biomedical imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed. The combined use of IVUS and OCT is hypothesized to remarkably increase diagnostic accuracy of vulnerable plaques. We have developed an integrated IVUS-OCT imaging apparatus, which includes the integrated catheter, motor drive unit, and imaging system. The dual-function imaging catheter has the same diameter of current clinical standard. The imaging system is capable for simultaneous IVUS and OCT imaging in real time. Ex vivo and in vivo experiments on rabbits with atherosclerosis were conducted to demonstrate the feasibility and superiority of the integrated intravascular imaging modality.

  2. Successful stent implantation guided by intravascular ultrasound and a Doppler guidewire without contrast injection in a patient with allergy to iodinated contrast media.

    PubMed

    Okura, Hiroyuki; Nezuo, Shintaro; Yoshida, Kiyoshi

    2011-07-01

    Presence of allergy to iodinated contrast may prevent percutaneous coronary intervention (PCI) to be performed. We present a 76-year-old male with a history of allergic reaction to iodinated contrast who successfully underwent intravascular ultrasound (IVUS) and a Doppler guidewire-guided PCI. Stent size was determined based on IVUS. After PCI, stent expansion and a lack of edge dissection or incomplete apposition were confirmed by IVUS and a good antegrade coronary flow was confirmed by a Doppler guidewire. Thus, PCI without contrast injection under IVUS and a Doppler guidewire-guidance may be feasible in selected patients with allergy to iodinated contrast. PMID:21725127

  3. A Case of Cystic Adventitial Degeneration of the Left Popliteal Artery Diagnosed by Intravascular Ultrasound

    PubMed Central

    Niizeki, Takeshi; Ishino, Mitsunori; Kitahara, Tatsuro; Yamauchi, So; Ikeno, Eiichiro; Kubota, Isao

    2016-01-01

    An 87-year-old male was admitted with intermittent claudication of the left calf. We performed lower extremity angiography, which revealed stenosis of the left popliteal artery. Intravascular ultrasound (IVUS) image correctly identified the cystic appearance of visualized extravascular hypodensity, causing extrinsic compression of the lumen. We diagnosed the condition as cystic adventitial degeneration (CAD) of the popliteal artery. We operated a resection of a cyst with the artery and replaced the autovein graft (saphenous vein). After surgery, the patient was free of symptoms. CAD is a rare disease; thus, our IVUS findings may provide unique diagnostic clues in patients with CAD. PMID:26949345

  4. Role of Intravascular Ultrasound in Patients with Acute Myocardial Infarction

    PubMed Central

    Hong, Young Joon; Ahn, Youngkeun

    2015-01-01

    Rupture of a vulnerable plaque and subsequent thrombus formation are important mechanisms leading to the development of an acute myocardial infarction (AMI). Typical intravascular ultrasound (IVUS) features of AMI include plaque rupture, thrombus, positive remodeling, attenuated plaque, spotty calcification, and thin-cap fibroatheroma. No-reflow phenomenon was attributable to the embolization of thrombus and plaque debris that results from mechanical fragmentation of the vulnerable plaque by percutaneous coronary intervention (PCI). Several grayscale IVUS features including plaque rupture, thrombus, positive remodeling, greater plaque burden, decreased post-PCI plaque volume, and tissue prolapse, and virtual histology-IVUS features such as large necrotic corecontaining lesion and thin-cap fibroatheroma were the independent predictors of no-reflow phenomenon in AMI patients. Non-culprit lesions associated with recurrent events were more likely than those not associated with recurrent events to be characterized by a plaque burden of ≥70%, a minimal luminal area of ≤4.0 mm2, or to be classified as thin-cap fibroatheromas. PMID:26240578

  5. A new method for IVUS-based coronary artery disease risk stratification: A link between coronary & carotid ultrasound plaque burdens.

    PubMed

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

    2016-02-01

    Interventional cardiologists have a deep interest in risk stratification prior to stenting and percutaneous coronary intervention (PCI) procedures. Intravascular ultrasound (IVUS) is most commonly adapted for screening, but current tools lack the ability for risk stratification based on grayscale plaque morphology. Our hypothesis is based on the genetic makeup of the atherosclerosis disease, that there is evidence of a link between coronary atherosclerosis disease and carotid plaque built up. This novel idea is explored in this study for coronary risk assessment and its classification of patients between high risk and low risk. This paper presents a strategy for coronary risk assessment by combining the IVUS grayscale plaque morphology and carotid B-mode ultrasound carotid intima-media thickness (cIMT) - a marker of subclinical atherosclerosis. Support vector machine (SVM) learning paradigm is adapted for risk stratification, where both the learning and testing phases use tissue characteristics derived from six feature combinational spaces, which are then used by the SVM classifier with five different kernels sets. These six feature combinational spaces are designed using 56 novel feature sets. K-fold cross validation protocol with 10 trials per fold is used for optimization of best SVM-kernel and best feature combination set. IRB approved coronary IVUS and carotid B-mode ultrasound were jointly collected on 15 patients (2 days apart) via: (a) 40MHz catheter utilizing iMap (Boston Scientific, Marlborough, MA, USA) with 2865 frames per patient (42,975 frames) and (b) linear probe B-mode carotid ultrasound (Toshiba scanner, Japan). Using the above protocol, the system shows the classification accuracy of 94.95% and AUC of 0.95 using optimized feature combination. This is the first system of its kind for risk stratification as a screening tool to prevent excessive cost burden and better patients' cardiovascular disease management, while validating our two hypotheses.

  6. Image-based device tracking for the co-registration of angiography and intravascular ultrasound images.

    PubMed

    Wang, Peng; Chen, Terrence; Ecabert, Olivier; Prummer, Simone; Ostermeier, Martin; Comaniciu, Dorin

    2011-01-01

    The accurate and robust tracking of catheters and transducers employed during image-guided coronary intervention is critical to improve the clinical workflow and procedure outcome. Image-based device detection and tracking methods are preferred due to the straightforward integration into existing medical equipments. In this paper, we present a novel computational framework for image-based device detection and tracking applied to the co-registration of angiography and intravascular ultrasound (IVUS), two modalities commonly used in interventional cardiology. The proposed system includes learning-based detections, model-based tracking, and registration using the geodesic distance. The system receives as input the selection of the coronary branch under investigation in a reference angiography image. During the subsequent pullback of the IVUS transducers, the system automatically tracks the position of the medical devices, including the IVUS transducers and guiding catheter tips, under fluoroscopy imaging. The localization of IVUS transducers and guiding catheter tips is used to continuously associate an IVUS imaging plane to the vessel branch under investigation. We validated the system on a set of 65 clinical cases, with high accuracy (mean errors less than 1.5mm) and robustness (98.46% success rate). To our knowledge, this is the first reported system able to automatically establish a robust correspondence between the angiography and IVUS images, thus providing clinicians with a comprehensive view of the coronaries.

  7. A novel dual-frequency imaging method for intravascular ultrasound applications.

    PubMed

    Qiu, Weibao; Chen, Yan; Wong, Chi-Man; Liu, Baoqiang; Dai, Jiyan; Zheng, Hairong

    2015-03-01

    Intravascular ultrasound (IVUS), which is able to delineate internal structures of vessel wall with fine spatial resolution, has greatly enriched the knowledge of coronary atherosclerosis. A novel dual-frequency imaging method is proposed in this paper for intravascular imaging applications. A probe combined two ultrasonic transducer elements with different center frequencies (36 MHz and 78 MHz) is designed and fabricated with PMN-PT single crystal material. It has the ability to balance both imaging depth and resolution, which are important imaging parameters for clinical test. A dual-channel imaging platform is also proposed for real-time imaging, and this platform has been proven to support programmable processing algorithms, flexible imaging control, and raw RF data acquisition for IVUS applications. Testing results show that the -6 dB axial and lateral imaging resolutions of low-frequency ultrasound are 78 and 132 μm, respectively. In terms of high-frequency ultrasound, axial and lateral resolutions are determined to be as high as 34 and 106 μm. In vitro intravascular imaging on healthy swine aorta is conducted to demonstrate the performance of the dual-frequency imaging method for IVUS applications. PMID:25454093

  8. Three-dimensional segmentation of luminal and adventitial borders in serial intravascular ultrasound images

    NASA Technical Reports Server (NTRS)

    Shekhar, R.; Cothren, R. M.; Vince, D. G.; Chandra, S.; Thomas, J. D.; Cornhill, J. F.

    1999-01-01

    Intravascular ultrasound (IVUS) provides exact anatomy of arteries, allowing accurate quantitative analysis. Automated segmentation of IVUS images is a prerequisite for routine quantitative analyses. We present a new three-dimensional (3D) segmentation technique, called active surface segmentation, which detects luminal and adventitial borders in IVUS pullback examinations of coronary arteries. The technique was validated against expert tracings by computing correlation coefficients (range 0.83-0.97) and William's index values (range 0.37-0.66). The technique was statistically accurate, robust to image artifacts, and capable of segmenting a large number of images rapidly. Active surface segmentation enabled geometrically accurate 3D reconstruction and visualization of coronary arteries and volumetric measurements.

  9. IVUS coronary volume alignment for distinct phases

    NASA Astrophysics Data System (ADS)

    Matsumoto, Monica Mitiko Soares; Lemos, Pedro Alves; Furuie, Sergio Shiguemi

    2009-02-01

    Image-based intravascular ultrasound (IVUS) cardiac phase detection allows coronary volume reconstruction in different phases. Consecutive volumes are not necessarily spatially aligned due to longitudinal movement of the catheter. Besides ordinary pullback velocity, there is a relative longitudinal movement of the heart vessel walls and the transducer, due to myocardial contraction. In this manuscript, we aim to spatially align cardiac phase coronary IVUS volumes. In addition, we want to investigate this non-linear longitudinal catheter movement. With this purpose, we have analyzed 120 simulated IVUS images and 10 real IVUS pullbacks. We implemented the following methodology. Firstly, we built IVUS volume for each distinct phase. Secondly, each IVUS volume was transformed into a parametric signal of average frame intensity. We have used these signals to make correlation in space with a reference one. Then we estimated the spatial distance between the distinct IVUS volumes and the reference. We have tested in simulated images and real examinations. We have also observed similar pattern in real IVUS examinations. This spatial alignment method is feasible and useful as a step towards dynamic studies of IVUS examination.

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

    PubMed

    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 <0.0001) and the amount of "necrotic core" from 0.59 +/- 0.65 to 1.31 +/- 0.87 mm(2) (p <0.0001). Most important, because this appearance occurs acutely, it is an artifact, and the red appearance should not be interpreted as peristrut inflammation or necrotic core when it is seen at follow-up. In conclusion, acutely implanted 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.

  11. A method for 3D reconstruction of coronary arteries using biplane angiography and intravascular ultrasound images.

    PubMed

    Bourantas, Christos V; Kourtis, Iraklis C; Plissiti, Marina E; Fotiadis, Dimitrios I; Katsouras, Christos S; Papafaklis, Michail I; Michalis, Lampros K

    2005-12-01

    The aim of this study is to describe a new method for the three-dimensional reconstruction of coronary arteries and its quantitative validation. Our approach is based on the fusion of the data provided by intravascular ultrasound images (IVUS) and biplane angiographies. A specific segmentation algorithm is used for the detection of the regions of interest in intravascular ultrasound images. A new methodology is also introduced for the accurate extraction of the catheter path. In detail, a cubic B-spline is used for approximating the catheter path in each biplane projection. Each B-spline curve is swept along the normal direction of its X-ray angiographic plane forming a surface. The intersection of the two surfaces is a 3D curve, which represents the reconstructed path. The detected regions of interest in the IVUS images are placed perpendicularly onto the path and their relative axial twist is computed using the sequential triangulation algorithm. Then, an efficient algorithm is applied to estimate the absolute orientation of the first IVUS frame. In order to obtain 3D visualization the commercial package Geomagic Studio 4.0 is used. The performance of the proposed method is assessed using a validation methodology which addresses the separate validation of each step followed for obtaining the coronary reconstruction. The performance of the segmentation algorithm was examined in 80 IVUS images. The reliability of the path extraction method was studied in vitro using a metal wire model and in vivo in a dataset of 11 patients. The performance of the sequential triangulation algorithm was tested in two gutter models and in the coronary arteries (marked with metal clips) of six cadaveric sheep hearts. Finally, the accuracy in the estimation of the first IVUS frame absolute orientation was examined in the same set of cadaveric sheep hearts. The obtained results demonstrate that the proposed reconstruction method is reliable and capable of depicting the morphology of

  12. A Four-Criterion Selection Procedure for Atherosclerotic Plaque Elasticity Reconstruction based on in Vivo Coronary Intravascular Ultrasound Radial Strain Sequences

    PubMed Central

    Le Floc’h, Simon; Cloutier, Guy; Saijo, Yoshifumi; Finet, Gérard; Yazdani, Saami K.; Deleaval, Flavien; Rioufol, Gilles; Pettigrew, Roderic I.; Ohayon, Jacques

    2016-01-01

    Plaque elasticity (i.e. modulogram) and morphology are good predictors of plaque vulnerability. Recently, our group developed an intravascular ultrasound (IVUS) elasticity reconstruction method which was successfully implemented in vitro using vessel phantoms. In vivo IVUS modulography, however, remains a major challenge as the motion of the heart prevents accurate strain field estimation. We therefore designed a technique to extract accurate strain fields and modulograms from recorded IVUS sequences. We identified a set of four criteria based on tissue overlapping, RF-correlation coefficient between two successive frames, performance of the elasticity reconstruction method to recover the measured radial strain, and reproducibility of the computed modulograms over the cardiac cycle. This 4-CSP was successfully tested on IVUS sequences obtained in twelve patients referred for a directional coronary atherectomy intervention. This study demonstrates the potential of the IVUS modulography technique based on the proposed 4-CSP to detect vulnerable plaques in vivo. PMID:23196202

  13. An IVUS Transducer for Microbubble Therapies

    PubMed Central

    Kilroy, Joseph P.; Patil, Abhay V.; Rychak, Joshua J.; Hossack, John A.

    2014-01-01

    There is interest in examining the potential of modified intravascular ultrasound (IVUS) catheters to facilitate dual diagnostic and therapeutic roles using ultrasound plus microbubbles for localized drug delivery to the vessel wall. The goal of this study was to design, prototype, and validate an IVUS transducer for microbubble-based drug delivery. A 1-D acoustic radiation force model and finite element analysis guided the design of a 1.5-MHz IVUS transducer. Using the IVUS transducer, biotinylated microbubbles were displaced in water and bovine whole blood to the streptavidin-coated wall of a flow phantom by a 1.5-MHz center frequency, peak negative pressure = 70 kPa pulse with varying pulse repetition frequency (PRF) while monitoring microbubble adhesion with ultrasound. A fit was applied to the RF data to extract a time constant (τ). As PRF was increased in water, the time constant decreased (τ = 32.6 s, 1 kHz vs. τ = 8.2 s, 6 kHz), whereas in bovine whole blood an adhesion–no adhesion transition was found for PRFs ≥ 8 kHz. Finally, a fluorophore was delivered to an ex vivo swine artery using microbubbles and the IVUS transducer, resulting in a 6.6-fold increase in fluorescence. These results indicate the importance of PRF (or duty factor) for IVUS acoustic radiation force microbubble displacement and the potential for IVUS and microbubbles to provide localized drug delivery. PMID:24569249

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

    PubMed Central

    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. Patients were followed through 12 months post-procedure. Results: Twenty-nine lesions were treated with OAS-BA in 25 patients. The mean maximum balloon inflation pressure was 5.2 ± 1.2 atm. Virtual histology IVUS (VH-IVUS) analysis revealed at the maximum calcium ablation site that calcium reduction was responsible for 86% of the lumen area increase. The minimum lumen area increased from 4.0 mm2 to 9.1 mm2 (<.0001), and the percentage of area stenosis decreased from 76.9% to 43.0% (<.0001) after OAS-BA. At 12 months, the target lesion revascularization rate was 8.2%, and ankle–brachial index and Rutherford classification improved significantly from baseline through follow-up. Conclusion: The VH-IVUS analysis reveals that OAS modifies the calcified component of the plaque burden. It is hypothesized that calcium modification by OAS changes the lesion compliance, allowing for low pressure adjunctive BA. The clinical outcomes were favorable through 12-month follow-up. PMID:26490645

  15. Intravascular Ultrasound Guidance for Transjugular Intrahepatic Portosystemic Shunt Procedure in a Swine Model

    SciTech Connect

    Kew, Jacqueline; Davies, Roger P.

    2004-01-15

    A new method is described for guiding hepato-portalvenous puncture using a longitudinal side-view intravascular ultrasound(L-IVUS) transducer to assist in the performance of transjugularintrahepatic portosystemic shunt (TIPS) in three Australian swine.Simultaneous L-IVUS with an AcuNav (registered) 5-10 MHz 10 Fr transducer(Acuson Corporation, Mountain View, CA, USA) and fluoroscopy guidance was used to image and monitor the hepatic to portal venous puncture,dilatation of the tract, and deployment of the TIPS stent. Flow through the shunt could be demonstrated with both L-IVUS and angiography. TIPS was successful in all swine. The time for portal vein puncture once the target portal vein was identified was reduced at each attempt. The number of portal vein puncture attempts was 2, 1, and 1. No post-procedural complication was evident. L-IVUS-guided TIPS is practical and has the potential to improve safety by permitting simultaneous ultrasound and fluoroscopic imaging of the needle and target vascular structures. This technique allows for a more streamlined approach to TIPS, decreasing the fluoroscopic time (hence,decreasing the radiation exposure to the staff and patient) and anesthetic time. In addition, there are improved safety benefits obviating the need for wedged portography, facilitating avoidance of bile duct and hepatic arterial puncture, and minimizing hepatic injury by decreasing liver capsular puncture and the attendant risks.

  16. Intravascular Photoacoustic Imaging

    PubMed Central

    Wang, Bo; Su, Jimmy L.; Karpiouk, Andrei B.; Sokolov, Konstantin V.; Smalling, Richard W.; Emelianov, Stanislav Y.

    2011-01-01

    Intravascular photoacoustic (IVPA) imaging is a catheter-based, minimally invasive, imaging modality capable of providing high-resolution optical absorption map of the arterial wall. Integrated with intravascular ultrasound (IVUS) imaging, combined IVPA and IVUS imaging can be used to detect and characterize atherosclerotic plaques building up in the inner lining of an artery. In this paper, we present and discuss various representative applications of combined IVPA/IVUS imaging of atherosclerosis, including assessment of the composition of atherosclerotic plaques, imaging of macrophages within the plaques, and molecular imaging of biomarkers associated with formation and development of plaques. In addition, imaging of coronary artery stents using IVPA and IVUS imaging is demonstrated. Furthermore, the design of an integrated IVUS/IVPA imaging catheter needed for in vivo clinical applications is discussed. PMID:21359138

  17. Utility of intravascular ultrasound in peripheral interventions.

    PubMed Central

    White, R A; Donayre, C E; Kopchok, G E; Walot, I; Mehringer, C M

    1997-01-01

    Endovascular imaging techniques encompass a variety of methods, including angiography, computed tomography, magnetic resonance imaging, angioscopy, and intravascular ultrasound. Each method provides unique information regarding the continuity of vascular structures and the morphology and distribution of lesions. Although arteriography has been the "gold standard" for imaging arterial anatomy, recent data have confirmed that even sophisticated arteriographic imaging substantially underestimates the degree of residual lesions, and that future observations and end-points for treatment will most likely be determined by data accumulated by computed tomography, magnetic resonance imaging, angioscopy, and intravascular ultrasound. Successful therapeutic applications of endovascular devices have developed because of improved patient selection using computed tomography, spiral computed tomography, magnetic resonance imaging, and computerized high-resolution angiography. Procedural success has been enhanced by improved mobile cinefluoroscopy, angioscopy, intraluminal ultrasound monitoring of angioplasty procedures, and the use of intravascular ultrasound for stent and stent-graft sizing and deployment. Newly developed methods and low-profile delivery systems enabling deployment and fixation of vascular prostheses by an endoluminal approach have heightened the interest of many interventionalists, particularly surgeons, in the use of endovascular surgical techniques. The evolution of this method promises to add a new dimension to the treatment of vascular lesions and relies heavily on the incorporation of miniaturized imaging systems, such as intravascular ultrasound, as a means to provide precise placement of devices. Images PMID:9068136

  18. Comparison of intravascular optical frequency domain imaging versus intravascular ultrasound during balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

    PubMed Central

    Kubota, Shuji; Okazaki, Toru; Hara, Hisao; Hiroi, Yukio

    2016-01-01

    Objectives The aims of this study are (1) to evaluate the safety and feasibility of using optical frequency domain imaging (OFDI) during balloon pulmonary angioplasty (BPA) procedures, (2) to assess the correlations between the vessel area (VA) and luminal area (LA) obtained by OFDI and intravascular ultrasound (IVUS), and (3) to compare inter‐ and intra‐observer variability among measurements taken from OFDI and IVUS images. Background The BPA in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is an evolving procedure. Methods Twenty‐three consecutive attempts of pair of OFDI and IVUS during BPA were evaluated. All complications that occurred during‐BPA and up to 48 hr post‐BPA were recorded. Using side branches as landmarks, 48 pairs of regions were chosen to compare measurements of VA and LA. Results OFDI images can be obtained without any procedurally related complications. Although the VA and LA measurements obtained by OFDI were smaller than those obtained by IVUS, high correlations were found (VA: r = 0.78, P < 0.0001 and LA: r = 0.75, P < 0.0001). Less inter‐ and intra‐observer variability was found when using measurements taken from OFDI versus IVUS images. Conclusions OFDI during BPA was safe and feasible. The reproducibility of OFDI imaging was excellent and offered a favorable addition to the BPA procedures. © 2016 The Authors Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc. PMID:26991798

  19. Intravascular ultrasound image segmentation: a three-dimensional fast-marching method based on gray level distributions.

    PubMed

    Cardinal, Marie-Hélène Roy; Meunier, Jean; Soulez, Gilles; Maurice, Roch L; Therasse, Eric; Cloutier, Guy

    2006-05-01

    Intravascular ultrasound (IVUS) is a catheter based medical imaging technique particularly useful for studying atherosclerotic disease. It produces cross-sectional images of blood vessels that provide quantitative assessment of the vascular wall, information about the nature of atherosclerotic lesions as well as plaque shape and size. Automatic processing of large IVUS data sets represents an important challenge due to ultrasound speckle, catheter artifacts or calcification shadows. A new three-dimensional (3-D) IVUS segmentation model, that is based on the fast-marching method and uses gray level probability density functions (PDFs) of the vessel wall structures, was developed. The gray level distribution of the whole IVUS pullback was modeled with a mixture of Rayleigh PDFs. With multiple interface fast-marching segmentation, the lumen, intima plus plaque structure, and media layers of the vessel wall were computed simultaneously. The PDF-based fast-marching was applied to 9 in vivo IVUS pullbacks of superficial femoral arteries and to a simulated IVUS pullback. Accurate results were obtained on simulated data with average point to point distances between detected vessel wall borders and ground truth <0.072 mm. On in vivo IVUS, a good overall performance was obtained with average distance between segmentation results and manually traced contours <0.16 mm. Moreover, the worst point to point variation between detected and manually traced contours stayed low with Hausdorff distances <0.40 mm, indicating a good performance in regions lacking information or containing artifacts. In conclusion, segmentation results demonstrated the potential of gray level PDF and fast-marching methods in 3-D IVUS image processing.

  20. Initial experience with a steerable intravascular ultrasound catheter in the aorta and pulmonary artery.

    PubMed

    Görge, G; Ge, J; Haude, M; Baumgart, D; Buck, T; Erbel, R

    1995-07-01

    The aim of this protocol was to test the feasibility and safety of a prototype steerable intravascular ultrasound (IVUS) catheter (Boston Scientific, Waterton, MA) in comparison with standard IVUS catheters. A 3.5F, 20-MHz mechanical echo transducer was incorporated into a bendable sheath with a blunt tip. The flexible IVUS catheter was compared with a standard IVUS catheter in 13 patients. Seven patients underwent catheterization of the left side of the heart, and six patients had catheterization of the right side of the heart for suspected recurrent pulmonary embolism. In the aorta, three lumen area measurements were made: (1) midway between the aortic arch and the aortic root, (2) at the most cranial part of the aorta, and (3) in the descending aorta at the level of the diaphragm. Evaluation of the accuracy of luminal dimension measurements by both types of catheters in perpendicular positions to the vessel wall was evaluated in a hollow rubber cast of an human aorta and its side branches, representing luminal diameters from 3 to 26 mm. We performed 20 measurements with each type of catheter. The results were compared with ruler measurements, after the cast had been cut in slices. The equation for the standard 3.5F IVUS catheter was: y = 0.89x + 0.15; SE = 0.17; r = .97; for the 4.8F 20-MHz standard IVUS catheter: y = 0.97x + 0.05; SE = 0.18; r = .98; and for the steerable catheter, y = 0.94x + 0.09; SE = 0.12; r = 0.97.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7549358

  1. Parametric Subharmonic Imaging Using a Commercial Intravascular Ultrasound Scanner An In Vivo Feasibility Study

    PubMed Central

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

    2013-01-01

    Objectives The feasibility of visualizing atherosclerotic plaque using parametric subharmonic intravascular ultrasound (IVUS) was investigated in vivo. Methods Atherosclerosis was induced in the aorta of 2 rabbits. Following injection of Definity (Lantheus Medical Imaging, North Billerica, MA), radiofrequency IVUS signals were acquired at 40 MHz with a Galaxy IVUS scanner (Boston Scientific/Scimed, Natick, MA). Subharmonic imaging (SHI; receiving at 20 MHz) was performed offline by applying an 8-order equalization filter. Contrast-to-tissue ratios (CTRs) were computed for the vessel relative to the plaque area over 4 time points. Contrast-to-tissue ratios were also calculated for the plaque-tissue and vessel-tissue from 4 tissue regions of interest at 4 time points. Finally, parametric images showing the cumulative maximum intensity (CMI), time to peak, perfusion (PER), and time-integrated intensity (TII) were generated for the fundamental and subharmonic data sets, and CTR measurements were repeated. Results Injection of the contrast agent resulted in improved delineation between plaque and the vessel lumen. Subharmonic imaging resulted in noticeable tissue suppression, although the intensity from the contrast agent was reduced. No significant improvement in the plaque to vessel lumen CTR was observed between the subharmonic and fundamental IVUS (2.1 ± 3.64 versus 2.2 ± 4.20; P = .5). However, the CTR for plaque-tissue was improved (11.8 ± 7.32 versus 9.9 ± 7.06; P < .0001) for SHI relative to fundamental imaging. Cumulative-maximum-intensity and TII maps of both fundamental and subharmonic data provided increased CTRs relative to nonparametric data sets (P< .002). Additionally, the CMI, PER, and TII of SHI IVUS showed significantly improved vessel-plaque CTRs for SHI relative to the fundamental (P < .04). Conclusions Parametric SHI IVUS of atherosclerotic plaque is feasible and improves the visualization of the plaque. PMID:22368126

  2. Distortion of intravascular ultrasound images because of nonuniform angular velocity of mechanical-type transducers.

    PubMed

    Kimura, B J; Bhargava, V; Palinski, W; Russo, R J; DeMaria, A N

    1996-08-01

    The purpose of this study was to quantify nonuniform rotation in a current mechanical intravascular ultrasound (IVUS) instrument and its effect on arc, area, and diameter measurements. The accurate reconstruction of IVUS two-dimensional images is dependent on uniform rotation of the catheter tip. Prior investigations suggested that bends in the catheter driveshaft may be responsible for poor torque transmission, nonuniform rotation, and consequent errors in IVUS measurements. Eight 30 MHz mechanically driven IVUS catheters were evaluated in a model simulating the catheter course through the aorta and coronary ostium in a clinical study. Angular velocity and posi-ion profiles of the transducer, image angle, and diameter and area measurement errors were obtained from each catheter by imaging a vascular phantom with eight equispaced echogenic markers from concentric and eccentric positions. Six catheters also were tested for comparison in a simple curvature model. Rotational error was found in all catheters tested and worsened in the aortic model. Maximal angular error, defined as the largest angle between actual and presumed transducer direction, increased when measured in the aortic model as compared with the simple curvature model (17 +/- 12 degrees to 45 +/- 25 degrees; p < 0.05). Angles of 45 degrees were misrepresented with a mean range of values of 26 to 63 degrees. With eccentric catheter placement, area and diameters had average maximal absolute errors of 26% +/- 7.8% and 23% +/- 10%, respectively. In conclusion, nonuniform rotation of mechanical IVUS transducers constitutes a significant potential source of error in IVUS measurement of arcs of calcification, and lumen shape, area, and diameter.

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

    PubMed

    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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:25991874

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  7. TWO NOVEL ACM (ACTIVE CONTOUR MODEL) METHODS FOR INTRAVASCULAR ULTRASOUND IMAGE SEGMENTATION

    SciTech Connect

    Chen, Chi Hau; Potdat, Labhesh; Chittineni, Rakesh

    2010-02-22

    One of the attractive image segmentation methods is the Active Contour Model (ACM) which has been widely used in medical imaging as it always produces sub-regions with continuous boundaries. Intravascular ultrasound (IVUS) is a catheter based medical imaging technique which is used for quantitative assessment of atherosclerotic disease. Two methods of ACM realizations are presented in this paper. The gradient descent flow based on minimizing energy functional can be used for segmentation of IVUS images. However this local operation alone may not be adequate to work with the complex IVUS images. The first method presented consists of basically combining the local geodesic active contours and global region-based active contours. The advantage of combining the local and global operations is to allow curves deforming under the energy to find only significant local minima and delineate object borders despite noise, poor edge information and heterogeneous intensity profiles. Results for this algorithm are compared to standard techniques to demonstrate the method's robustness and accuracy. In the second method, the energy function is appropriately modified and minimized using a Hopfield neural network. Proper modifications in the definition of the bias of the neurons have been introduced to incorporate image characteristics. The method overcomes distortions in the expected image pattern, such as due to the presence of calcium, and employs a specialized structure of the neural network and boundary correction schemes which are based on a priori knowledge about the vessel geometry. The presented method is very fast and has been evaluated using sequences of IVUS frames.

  8. Advances in a fully integrated intravascular OCT-ultrasound system for cardiovascular imaging

    NASA Astrophysics Data System (ADS)

    Jing, Joe; Li, Jiawen; Li, Xiang; Yin, Jiechen; Zhang, Jun; Hoang, Khiet; Patel, Pranav; Zhou, Qifa; Chen, Zhongping

    2012-01-01

    Intracoronary optical coherence tomography (OCT) and intravascular ultrasound (IVUS) are two popular techniques for the detection and determination of atherosclerosis. IVUS allows visualization of plaques while also providing a large penetration depth to determine plaque volume. Intracoronary OCT provides the ability to capture microscopic features associated with high risk plaque. Traditionally to utilize the benefits of both modalities, separate probes and systems had to be used one at a time to image a vessel. We present work required to create a combined OCT IVUS system capable of simultaneous imaging to detect atherosclerotic plaques. A novel integrated probe of size 0.69 mm OD featuring sequential placement of components was created to acquire co-registered images within small coronary vessels. By utilizing commercial graphics processing units (GPUs) real time visualization of acquired data is possible up to a maximum 48 frames per second per channel. In vitro studies on human coronary artery samples as well as in vivo studies in rabbits and pigs show various plaque buildups in both OCT and IVUS images which match histology results, demonstrating the capabilities of the system.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. X-IVUS: integrated x-ray and IVUS system for the Cathlab

    NASA Astrophysics Data System (ADS)

    Martin-Leung, Barbara; Eck, Kai; Bredno, Joerg; Aach, Til

    2005-04-01

    Percutaneous Transluminal Coronary Angioplasty is currently the preferred method for coronary artery disease treatment. Angiograms depict residual lumen, but lack information about plaque characteristics and exact geometry. During instrument positioning, intracoronary characterization at the current instrument location is desirable. By pulling back an intravascular ultrasound (IVUS) probe through a stenosis, cross-sections of the artery are acquired. These images can provide the desired characterization if they are properly registered to diagnostic angiograms or interventional fluoroscopies. The method we propose acquires fluoroscopy frames at the beginning, end, and optionally during a constant speed pullback. The IVUS probe is localized and registered to previously acquired angiograms using a compensation algorithm for heartbeat and respiration. Then, for each heart phase, the pullback path is interpolated and the corresponding IVUS frames are positioned. During the intervention the instrument is localized and registered onto the pullback path. Thus, each IVUS frame can be registered with a position on an angiogram or to an instrument location and during subsequent steps of the intervention the appropriate IVUS frames can be displayed as if an IVUS probe were present at the instrument position. The method was tested using a phantom featuring respiratory and contraction movement and an automatic pullback with constant speed. The IVUS acquisition was replaced by fibre optics and the phantom was imaged in angiographic and fluoroscopic modes. The study showed that for the phantom case it is indeed possible to register the IVUS cross-section to the interventional instrument positions to an accuracy of less than 2mm.

  11. Accurate 3D reconstruction of complex blood vessel geometries from intravascular ultrasound images: in vitro study.

    PubMed

    Subramanian, K R; Thubrikar, M J; Fowler, B; Mostafavi, M T; Funk, M W

    2000-01-01

    We present a technique that accurately reconstructs complex three dimensional blood vessel geometry from 2D intravascular ultrasound (IVUS) images. Biplane x-ray fluoroscopy is used to image the ultrasound catheter tip at a few key points along its path as the catheter is pulled through the blood vessel. An interpolating spline describes the continuous catheter path. The IVUS images are located orthogonal to the path, resulting in a non-uniform structured scalar volume of echo densities. Isocontour surfaces are used to view the vessel geometry, while transparency and clipping enable interactive exploration of interior structures. The two geometries studied are a bovine artery vascular graft having U-shape and a constriction, and a canine carotid artery having multiple branches and a constriction. Accuracy of the reconstructions is established by comparing the reconstructions to (1) silicone moulds of the vessel interior, (2) biplane x-ray images, and (3) the original echo images. Excellent shape and geometry correspondence was observed in both geometries. Quantitative measurements made at key locations of the 3D reconstructions also were in good agreement with those made in silicone moulds. The proposed technique is easily adoptable in clinical practice, since it uses x-rays with minimal exposure and existing IVUS technology. PMID:11105284

  12. Lead-free intravascular ultrasound transducer using BZT-50BCT ceramics.

    PubMed

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

    2013-06-01

    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)TiO4(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.

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

    PubMed Central

    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

  14. Lead-free intravascular ultrasound transducer using BZT-50BCT ceramics.

    PubMed

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

    2013-06-01

    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)TiO4(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

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

    NASA Astrophysics Data System (ADS)

    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.

  16. An algorithm to correct 2D near-infrared fluorescence signals using 3D intravascular ultrasound architectural information

    NASA Astrophysics Data System (ADS)

    Mallas, Georgios; Brooks, Dana H.; Rosenthal, Amir; Vinegoni, Claudio; Calfon, Marcella A.; Razansky, R. Nika; Jaffer, Farouc A.; Ntziachristos, Vasilis

    2011-03-01

    Intravascular Near-Infrared Fluorescence (NIRF) imaging is a promising imaging modality to image vessel biology and high-risk plaques in vivo. We have developed a NIRF fiber optic catheter and have presented the ability to image atherosclerotic plaques in vivo, using appropriate NIR fluorescent probes. Our catheter consists of a 100/140 μm core/clad diameter housed in polyethylene tubing, emitting NIR laser light at a 90 degree angle compared to the fiber's axis. The system utilizes a rotational and a translational motor for true 2D imaging and operates in conjunction with a coaxial intravascular ultrasound (IVUS) device. IVUS datasets provide 3D images of the internal structure of arteries and are used in our system for anatomical mapping. Using the IVUS images, we are building an accurate hybrid fluorescence-IVUS data inversion scheme that takes into account photon propagation through the blood filled lumen. This hybrid imaging approach can then correct for the non-linear dependence of light intensity on the distance of the fluorescence region from the fiber tip, leading to quantitative imaging. The experimental and algorithmic developments will be presented and the effectiveness of the algorithm showcased with experimental results in both saline and blood-like preparations. The combined structural and molecular information obtained from these two imaging modalities are positioned to enable the accurate diagnosis of biologically high-risk atherosclerotic plaques in the coronary arteries that are responsible for heart attacks.

  17. Intravascular imaging in Kounis syndrome: role of IVUS and OCT in achieving an etiopathogenic diagnosis

    PubMed Central

    Domínguez, Fernando; Santos, Susana Mingo; Escudier-Villa, Juan Manuel; Jiménez-Sánchez, Diego; Artaza, Josebe Goirigolzarri; Alonso-Pulpón, Luis; Goicolea, Javier

    2015-01-01

    We report a case of a 60-year-old male patient presenting with anaphylactic response to anchovies associated with an acute coronary syndrome. His history was remarkable for coronary artery disease treated with a drug eluting stent to the right coronary artery six years before and stent fracture documented by coronary angiography four years prior to the event. Coronary angiography on admission revealed a very late stent thrombosis (VLST) in the right coronary artery. Intracoronary imaging techniques (IVUS and OCT) were used and were key to discard main causes of VLST. We described the characteristics of intracoronary images, along with the advantages and disadvantages of these techniques. The findings described in this case could explain a new physiopathological mechanism of stent thrombosis occurring in stent fractures. PMID:25774348

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

    PubMed

    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 <0.01) and a negative correlation with percentage of fibrous tissue (r = -0.81, p <0.01). In conclusion, IVUS-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.

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

    PubMed

    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 <0.01) and a negative correlation with percentage of fibrous tissue (r = -0.81, p <0.01). In conclusion, IVUS-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. PMID:27289292

  20. Insights into the pathogenesis of vein graft disease: lessons from intravascular ultrasound

    PubMed Central

    Murphy, Gavin J; Angelini, Gianni D

    2004-01-01

    The success of coronary artery bypass grafting (CABG) is limited by poor long-term graft patency. Saphenous vein is used in the vast majority of CABG operations, although 15% are occluded at one year with as many as 50% occluded at 10 years due to progressive graft atherosclerosis. Intravascular ultrasound (IVUS) has greatly increased our understanding of this process. IVUS studies have shown that early wall thickening and adaptive remodeling of vein grafts occurs within the first few weeks post implantation, with these changes stabilising in angiographically normal vein grafts after six months. Early changes predispose to later atherosclerosis with occlusive plaque detectable in vein grafts within the first year. Both expansive and constrictive remodelling is present in diseased vein grafts, where the latter contributes significantly to occlusive disease. These findings correlate closely with experimental and clinicopathological studies and help define the windows for prevention, intervention or plaque stabilisation strategies. IVUS is also the natural tool for evaluating the effectiveness of pharmacological and other treatments that may prevent or slow the progression of vein graft disease in clinical trials. PMID:15268762

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

    PubMed

    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. PMID:27567774

  2. Fast integrated intravascular photoacoustic/ultrasound catheter

    NASA Astrophysics Data System (ADS)

    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.

  3. Radiographic and Intravascular (IVUS) Evaluation of Venous Morphology During CCSVI Treatment

    ClinicalTrials.gov

    2012-05-06

    To Determine the Safety and Validity of Venous Angioplasty and; Valvuloplasty in the Treatment of CCSVI. In Addition, it Will; Allow Researchers to Sub-classify Valve Morphology in Relation; to Treatment Success. This Will be Evidenced by Venous Patency; Forty-eight Hours by Doppler Ultrasound as Well as Clinical; Symptom Improvement.

  4. Intravascular OCT

    NASA Astrophysics Data System (ADS)

    Schmitt, Joseph M.; Adler, Desmond; Xu, Chenyang

    Since the first coronary angioplasty was performed in the late 1970s, imaging has played a central role in percutaneous coronary intervention (PCI). Today more than three million PCI procedures are performed worldwide to expand narrowed arteries and to clear blood clots that can cause debilitating symptoms of myocardial ischemia or fatal heart attacks. Although X-ray angiography is still the workhorse imaging modality in the field of interventional cardiology, intravascular imaging has become an indispensable tool for guiding complex PCI procedures. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are the two most commonly used catheter-based imaging technologies in coronary procedures. Since the first commercial intravascular OCT systems were introduced in Japan and the European Union in 2004 and in the United States in 2009, the application of intravascular OCT has grown rapidly [3, 15, 16].

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

    PubMed

    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.

  6. Effect of Intravascular Ultrasound-assisted Thoracic Endovascular Aortic Repair for “Complicated” Type B Aortic Dissection

    PubMed Central

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

    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

  7. NON-RIGID IMAGE REGISTRATION BASED STRAIN ESTIMATOR FOR INTRAVASCULAR ULTRASOUND ELASTOGRAPHY

    PubMed Central

    Richards, Michael S.; Doyley, Marvin M.

    2013-01-01

    Intravascular ultrasound elastography (IVUSe) could improve the diagnosis of cardiovascular disease by revealing vulnerable plaques through their mechanical tissue properties. To improve the performance of IVUSe, we developed and implemented a non-rigid image-registration method to visualize the radial and circumferential component of strain within vascular tissues. We evaluated the algorithm’s performance with four initialization schemes using simulated and experimentally acquired ultrasound images. Applying the registration method to radio-frequency (RF) echo frames improved the accuracy of displacements compared to when B-mode images were employed. However, strain elastograms measured from RF echo frames produce erroneous results when both the zero-initialization method and the mesh-refinement scheme were employed. For most strain levels, the cross-correlation-initialization method produced the best performance. The simulation study predicted that elastograms obtained from vessels with average strains in the range of 3%–5% should have high elastographic signal-to-noise ratio (SNRe)–on the order of 4.5 and 7.5 for the radial and circumferential components of strain, respectively. The preliminary in vivo validation study (phantom and an atherosclerotic rabbit) demonstrated that the non-rigid registration method could produce useful radial and circumferential strain elastograms under realistic physiologic conditions. The results of this investigation were sufficiently encouraging to warrant a more comprehensive in vivo validation. PMID:23245827

  8. VISUALIZING THE STRESS DISTRIBUTION WITHIN VASCULAR TISSUES USING INTRAVASCULAR ULTRASOUND ELASTOGRAPHY: A PRELIMINARY INVESTIGATION

    PubMed Central

    Richards, Michael S.; Perucchio, Renato; Doyley, Marvin M.

    2015-01-01

    A methodology for computing the stress distribution of vascular tissue using finite element-based, intravascular ultrasound (IVUS) reconstruction elastography is described. This information could help cardiologists detect life-threatening atherosclerotic plaques and predict their propensity to rupture. The calculation of vessel stresses requires the measurement of strain from the ultrasound images, a calibrating pressure measurement and additional model assumptions. In this work, we conducted simulation studies to investigate the effect of varying the model assumptions, specifically Poisson’s ratio and the outer boundary conditions, on the resulting stress fields. In both simulation and phantom studies, we created vessel geometries with two fibrous cap thicknesses to determine if we could detect a difference in peak stress (spatially) between the two. The results revealed that (i) Poisson’s ratios had negligible impact on the accuracy of stress elastograms, (ii) the outer boundary condition assumption had the greatest effect on the resulting modulus and stress distributions and (iii) in simulation and in phantom experiments, our stress imaging technique was able to detect an increased peak stress for the vessel geometry with the smaller cap thickness. This work is a first step toward understanding and creating a robust stress measurement technique for evaluating atherosclerotic plaques using IVUS elastography. PMID:25837424

  9. Neointimal tissue healing patterns after paclitaxel-eluting balloon treatment of in-stent restenosis: optical coherence tomography and intravascular ultrasound insights.

    PubMed

    Sandoval, Jorge; Medina, Miguel; Alfonso, Fernando

    2012-10-01

    An 80-year-old patient presented with severe in-stent restenosis of an everolimus-eluting stent implanted in the left anterior descending coronary artery 3 years previously. We obtained good angiographic result after paclitaxel-eluting balloon dilation. However, on optical coherence tomography (OCT), multiple, angiographically silent, in-stent, and edge-related dissections were readily recognized. Intravascular ultrasound (IVUS) revealed residual neointima with minor disruptions. At 9-month follow-up, an excellent angiographic result was demonstrated with complete resolution of the stent-related dissections on OCT. IVUS and OCT confirmed complete neointimal healing with a larger lumen. This case illustrates the value of OCT and IVUS to provide unique insights on the pathophysiological mechanisms and healing patterns of paclitaxel-eluting balloon treatment of in-stent restenosis.

  10. CONTRAST-ENHANCED INTRAVASCULAR ULTRASOUND PULSE SEQUENCES FOR BANDWIDTH-LIMITED TRANSDUCERS

    PubMed Central

    Maresca, David; Renaud, Guillaume; van Soest, Gijs; Li, Xiang; Zhou, Qifa; Shung, K. Kirk; de Jong, Nico; van der Steen, Antonius F. W.

    2013-01-01

    We demonstrate two methods for vasa vasorum imaging using contrast-enhanced intravascular ultrasound, which can be performed using commercial catheters. Plaque neovascularization was recognized as an independent marker of coronary artery plaque vulnerability. IVUS-based methods to image the microvessels available to date require high bandwidth (−6 dB relative frequency bandwidth >70%), which are not routinely available commercially. We explored the potential of ultraharmonic imaging and chirp reversal imaging for vasa vasorum imaging. In vitro recordings were performed on a tissue-mimicking phantom using a commercial ultrasound contrast agent and a transducer with a center frequency of 34 MHz and a −6 dB relative bandwidth of 56%. Acoustic peak pressures <500 kPa were used. A tissue-mimicking phantom with channels down to 200 μm in diameter was successfully imaged by the two contrast detection sequences while the smallest channel stayed invisible in conventional intravascular ultrasound images. Ultraharmonic imaging provided the best contrast agent detection. PMID:23384459

  11. Intravascular Ultrasound Catheter to Enhance Microbubble-Based Drug Delivery via Acoustic Radiation Force

    PubMed Central

    Kilroy, Joseph P.; Klibanov, Alexander L.; Wamhoff, Brian R.; Hossack, John A.

    2015-01-01

    Previous research has demonstrated that acoustic radiation force enhances intravascular microbubble adhesion to blood vessels in the presence of flow for molecular-targeted ultrasound imaging and drug delivery. A prototype acoustic radiation force intravascular ultrasound (ARFIVUS) catheter was designed and fabricated to displace a microbubble contrast agent in flow representative of conditions encountered in the human carotid artery. The prototype ARFIVUS transducer was designed to match the resonance frequency of 1.4- to 2.6-μm-diameter microbubbles modeled by an experimentally verified 1-D microbubble acoustic radiation force translation model. The transducer element was an elongated Navy Type I (hard) lead zirconate titanate (PZT) ceramic designed to operate at 3 MHz. Fabricated devices operated with center frequencies of 3.3 and 3.6 MHz with −6-dB fractional bandwidths of 55% and 50%, respectively. Microbubble translation velocities as high as 0.86 m/s were measured using a high-speed streak camera when insonating with the ARFIVUS transducer. Finally, the prototype was used to displace microbubbles in a flow phantom while imaging with a commercial 45-MHz imaging IVUS transducer. A sustained increase of 31 dB in average video intensity was measured following insonation with the ARFIVUS, indicating microbubble accumulation resulting from the application of acoustic radiation force. PMID:23143566

  12. Intravascular Ultrasound Classification of Plaque in Angiographic True Bifurcation Lesions of the Left Main Coronary Artery

    PubMed Central

    Li, Li; Dash, Debabrata; Gai, Lu-Yue; Cao, Yun-Shan; Zhao, Qiang; Wang, Ya-Rong; Zhang, Yao-Jun; Zhang, Jun-Xia

    2016-01-01

    Background: Accurately, characterizing plaques is critical for selecting the optimal intervention strategy for the left main coronary artery (LMCA) bifurcation. Coronary angiography cannot precisely assess the location or nature of plaques in bifurcation lesions. Few intravascular ultrasound (IVUS) classification scheme has been reported for angiographic imaging of true bifurcation lesions of the unprotected LMCA thus far. In addition, the plaque composition at the bifurcation has not been elucidated. This study aimed to detect plaque composition at LMCA bifurcation lesions by IVUS. Methods: Fifty-eight patients were recruited. The location, concentricity or eccentricity, site of maximum thickness, and composition of plaques of the distal LMCA, ostial left anterior descending (LAD) coronary artery and, left circumflex (LCX) coronary artery were assessed using IVUS and described using illustrative diagrams. Results: True bifurcation lesions of the unprotected LMCA were classified into four types: Type A, with continuous involvement from the distal LMCA to the ostial LAD and the ostial LCX with eccentric plaques; Type B, with concentric plaques at the distal LMCA, eccentric plaques at the ostial LAD, and no plaques at the LCX; Type C, with continuous involvement from the distal LMCA to the ostial LCX, with eccentric plaques, and to the ostial LAD, with eccentric plaques; and Type D, with continuous involvement from the distal LMCA to the ostial LAD, with eccentric plaques, and to the ostial LCX, with concentric plaques. The carina was involved in only 3.5% of the plaques. A total of 51.7% of the plaques at the ostium of the LAD were soft, while 44.8% and 44.6% were fibrous in the distal LMCA and in the ostial LCX, respectively. Conclusions: We classified LMCA true bifurcation lesions into four types. The carina was always free from disease. Plaques at the ostial LAD tended to be soft, whereas those at the ostial LCX and the distal LMCA tended to be fibrous. PMID

  13. Usefulness of Intravascular Ultrasound for Predicting Risk of Intraprocedural Stent Thrombosis.

    PubMed

    Morofuji, Toru; Inaba, Shinji; Hitsumoto, Tatsuro; Takahashi, Kayo; Aisu, Hiroe; Higashi, Haruhiko; Saito, Makoto; Ohshima, Kiyotaka; Ikeda, Shuntaro; Hamada, Mareomi; Sumimoto, Takumi

    2016-03-15

    Intraprocedural stent thrombosis (IPST) is a rare complication of percutaneous coronary intervention that leads to poor outcomes; however, the factors contributing to IPST remain largely unknown. Accordingly, we used intravascular ultrasound (IVUS) to examine the lesion characteristics in patients with IPST. We retrospectively analyzed 1,504 consecutive stent-implanted lesions in 1,324 patients (326 with ST-segment elevation myocardial infarction [STEMI], 403 patients with non-ST-segment elevation acute coronary syndrome [NSTE-ACS], and 595 patients with stable angina). Of these, IPST occurred in 5 patients during percutaneous coronary intervention (0.4% per patient; 3 with STEMI, 2 with NSTE-ACS). The IVUS characteristics of plaques that developed IPST were compared with those of controls without the evidence of IPST (non-IPST; n = 15) who were matched by age, gender, lesion location, and clinical presentation (STEMI, NSTE-ACS, or stable angina). All 5 lesions that led to IPST had ruptured plaques with positive remodeling and attenuation. Plaque rupture was also observed in 40% of the non-IPST group. Multiple plaque ruptures in the culprit lesion were more common in the IPST group (80% vs 7%; p <0.01). The maximum cavity area was larger in the IPST group than in the non-IPST group having plaque rupture (4.6 mm(2) [interquartile range, 4.3 to 6.5] vs 2.4 mm(2) [1.8 to 2.9]; p <0.01). In conclusion, we found using IVUS that multiple plaque ruptures with larger cavities more often evolved into IPST. PMID:26822168

  14. Side-Branch and Coaxial Intravascular Ultrasound Guided Wire Re-Entry after Failed Retrograde Approach of Chronic Total Occlusion Intervention

    PubMed Central

    Chou, Ruey-Hsing; Lai, Chih-Hung; Lu, Tse-Min

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information during the intervention of difficult chronic total occlusion (CTO) lesion. Stumpless CTO lesions with an adjacent side branch are associated with a significantly lower success rate because the proper entry point is not always clearly identified and the guidewires easily slip into the side branch. Herein we presented a case of a stumpless middle left circumflex (LCX) artery CTO lesion with auto-collateral from obtuse marginal branch. Initially, we positioned the IVUS into the side-branch to find the entry point of LCX-CTO lesion. However, the punctured wire went into the false lumen. A retrograde approach was tried but later failed. Therefore, we used IVUS to find the entry point where the true lumen transited to the false lumen, and used a stiff guidewire to puncture the entry point. After we confirmed with IVUS that the whole guidewire was in the true lumen, we deployed 3 drug-eluting stents. The final angiogram showed TIMI 3 flow with preservation of all side branches. The patient was angina-free during the 6-month follow-up. By presenting this case, we have demonstrated the application of both side-branch and coaxial IVUS-guided recanalization technique in the stumpless CTO lesion. PMID:27274179

  15. Coronary plaque progression of non-culprit lesions after culprit percutaneous coronary intervention in patients with moderate to advanced chronic kidney disease: intravascular ultrasound and integrated backscatter intravascular ultrasound study.

    PubMed

    Kashiyama, Kuninobu; Sonoda, Shinjo; Muraoka, Yoshitaka; Suzuki, Yoshiyuki; Kamezaki, Fumihiko; Tsuda, Yuki; Araki, Masaru; Tamura, Masahito; Takeuchi, Masaaki; Abe, Haruhiko; Okazaki, Masahiro; Fujino, Yoshihisa; Otsuji, Yutaka

    2015-06-01

    Previous studies have suggested that the deterioration of renal function increases the risk of major adverse clinical events not only in culprit lesions but also in non-culprit lesions (NCLs) after percutaneous coronary intervention (PCI). This study evaluated serial coronary plaque change of NCL in patients with different stages of chronic kidney disease (CKD) using intravascular ultrasound (IVUS) and integrated backscatter IVUS (IB-IVUS). In 113 patients (113 NCLs) underwent both IVUS-guided PCI and follow-up IVUS, volumetric IVUS analyses were performed at proximal reference NCLs in de novo target vessels post PCI and at 8-month follow-up. NCLs were divided into 4 groups based on baseline CKD stage: CKD-1, n = 18; CKD-2, n = 42; CKD-3, n = 29; and CKD4-5, n = 24. We compared serial changes of plaque burden and composition among groups under statin treatment. Plaque progression occurred in CKD-3 (+4.6 mm(3), p < 0.001) and CKD4-5 (+9.8 mm(3), p < 0.001) despite anti-atherosclerotic treatment, whereas plaque regression occurred in CKD-1 (-5.4 mm(3), p = 0.002) and CKD-2 (-3.2 mm(3), p = 0.001) mainly due to initiate statin treatment after PCI. Plaque volume change was correlated with eGFR (p < 0.0001). Multivariate analysis showed CKD stage 3-5 was an independent predictor of plaque progression. Regarding IB-IVUS analyses, lipid plaque increased in CKD-3 (+4.6 mm(3), p < 0.001) and CKD4-5 (+5.4 mm(3), p < 0.001), but decreased in CKD-2 (-2.7 mm(3), p < 0.05). Fibrotic plaque also increased in CKD4-5 (+3.4 mm(3), p < 0.001). Moderate to advanced CKD was associated with coronary plaque progression characterized by greater lipid and fibrotic plaque volumes in NCL under statin treatment after culprit PCI. PMID:25724567

  16. Direct Comparison of Virtual-Histology Intravascular Ultrasound and Optical Coherence Tomography Imaging for Identification of Thin-Cap Fibroatheroma

    PubMed Central

    Brown, Adam J.; Obaid, Daniel R.; Costopoulos, Charis; Parker, Richard A.; Calvert, Patrick A.; Teng, Zhongzhao; Hoole, Stephen P.; West, Nick E.J.; Goddard, Martin

    2015-01-01

    Background— Although rupture of thin-cap fibroatheroma (TCFA) underlies most myocardial infarctions, reliable TCFA identification remains challenging. Virtual-histology intravascular ultrasound (VH-IVUS) and optical coherence tomography (OCT) can assess tissue composition and classify plaques. However, direct comparisons between VH-IVUS and OCT are lacking and it remains unknown whether combining these modalities improves TCFA identification. Methods and Results— Two hundred fifty-eight regions-of-interest were obtained from autopsied human hearts, with plaque composition and classification assessed by histology and compared with coregistered ex vivo VH-IVUS and OCT. Sixty-seven regions-of-interest were classified as fibroatheroma on histology, with 22 meeting criteria for TCFA. On VH-IVUS, plaque (10.91±4.82 versus 8.42±4.57 mm2; P=0.01) and necrotic core areas (1.59±0.99 versus 1.03±0.85 mm2; P=0.02) were increased in TCFA versus other fibroatheroma. On OCT, although minimal fibrous cap thickness was similar (71.8±44.1 μm versus 72.6±32.4; P=0.30), the number of continuous frames with fibrous cap thickness ≤85 μm was higher in TCFA (6.5 [1.75–11.0] versus 2.0 [0.0–7.0]; P=0.03). Maximum lipid arc on OCT was an excellent discriminator of fibroatheroma (area under the curve, 0.92; 95% confidence interval, 0.87–0.97) and TCFA (area under the curve, 0.86; 95% confidence interval, 0.81–0.92), with lipid arc ≥80° the optimal cut-off value. Using existing criteria, the sensitivity, specificity, and diagnostic accuracy for TCFA identification was 63.6%, 78.1%, and 76.5% for VH-IVUS and 72.7%, 79.8%, and 79.0% for OCT. Combining VH-defined fibroatheroma and fibrous cap thickness ≤85 μm over 3 continuous frames improved TCFA identification, with diagnostic accuracy of 89.0%. Conclusions— Both VH-IVUS and OCT can reliably identify TCFA, although OCT accuracy may be improved using lipid arc ≥80° and fibrous cap thickness ≤85 μm over 3

  17. Plaque Composition and No-Reflow Phenomenon During Percutaneous Coronary Intervention of Low-Echoic Structures in Grayscale Intravascular Ultrasound.

    PubMed

    Amano, Hideo; Ikeda, Takanori; Toda, Mikihito; Okubo, Ryo; Yabe, Takayuki; Watanabe, Ippei; Saito, Daiga

    2016-05-25

    It has been reported that coronary vasa vasorum is associated with plaque vulnerability, and low-echoic structures in grayscale intravascular ultrasound (IVUS) are consistent pathologically with vasa vasorum. However, the association of low-echoic structures with plaque composition and no-reflow phenomenon during percutaneous coronary intervention (PCI) is unclear. We investigated plaque composition in virtual histology IVUS (VH-IVUS) and no-reflow phenomenon during PCI of low-echoic structures.A total of 106 lesions being treated by VH-IVUS before PCI were included in this study. Low-echoic structure was defined as a small tubular structure exterior to media without a connection to the vessel lumen in ≥ 3 consecutive crosssectional IVUS images. Lesions with low-echoic structures were found in 42% (45/106).Lesions with low-echoic structures were more prevalent in acute coronary syndrome (ACS) patients (53% [24/45] versus 20% [12/61], P < 0.001), had more positive remodeling (49% [22/45] versus 21% [13/61], P = 0.003), a larger number of VH-IVUS derived thin-cap fibroatheromas (VH-TCFAs) (0.64 ± 0.53 versus 0.05 ± 0.22, P < 0.001), more VH-TCFAs with a baseline plaque burden of 70% or more and minimal luminal area of 4.0 mm(2) or less (29% [13/45] versus 2% [1/61], P < 0.001), and more frequent no-reflow phenomenon after stent implantation and more final TIMI flow grade 0/1/2 (38% [17/45] versus 5% [3/61], P < 0.001; 9% [4/45] versus 0% [0/61], P = 0.03) than lesions without low-echo structures.Lesions with low-echoic structures in grayscale IVUS had high plaque vulnerability and were more prevalent in ACS patients, positive remolding, and VH-TCFAs, and they had more frequent no-reflow phenomenon during PCI than lesions without low-echoic structures.

  18. Subacute stent thrombosis and the anticoagulation controversy: changes in drug therapy, operator technique, and the impact of intravascular ultrasound.

    PubMed

    Moussa, I; Di Mario, C; Di Francesco, L; Reimers, B; Blengino, S; Colombo, A

    1996-08-14

    Clinical trials have shown that stents are superior to other catheter-based coronary interventions in terms of reduced complications and improved long-term efficacy. With utilization of high-pressure balloon inflation and intravascular ultrasound (IVUS) guidance, stent implantation can now be performed safely without anticoagulation (i.e., with lower rates of stent thrombosis and vascular complications). In 2 recent prospective clinical trials, stent thrombosis occurred in 3.5% of cases despite anticoagulant therapy, which resulted in an average of 7% vascular and bleeding complications. Initial use of IVUS during traditional stent deployment showed that 80% of stents were underexpanded and led to the hypothesis that stent thrombosis might be decreased as a result of optimal stent placement under IVUS guidance without the need for anticoagulation. In a prospective clinical trial to test this hypothesis, three factors were found to reduce stent thrombosis: full stent expansion, complete apposition to the vessel wall, and full lesion coverage. Predictors of thrombotic risk in this era of high-pressure stent deployment without anticoagulation include low ejection fraction, residual dissections, slow flow, multiple stents per lesion, and smaller postprocedure stent luminal diameter. To optimize stent expansion, stent dilation should be performed using a mean inflation pressure of 18 atm with a noncompliant or minimally compliant balloon sized to the vessel being treated (B/V ratio = 1.1). Controversy still remains about the best poststent antiplatelet regimen, and results of a recent trial should indicate whether heparin coating provides additional protection from stent thrombosis.

  19. Application of tissue characterization in intravascular ultrasound imaging

    NASA Astrophysics Data System (ADS)

    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.

  20. Does the specific intravascular ultrasound criterion used to optimize stent expansion have an impact on the probability of stent restenosis?

    PubMed

    Moussa, I; Moses, J; Di Mario, C; Albiero, R; De Gregorio, J; Adamian, M; Di Francesco, L; Colombo, A

    1999-04-01

    Intravascular ultrasound (IVUS) imaging has been used to optimize stent implantation in coronary arteries, but the criteria used were chosen on an empiric basis. The aim of this study was to determine whether any of these criteria have an independent role in predicting the probability of freedom from restenosis. The study population consisted of 425 patients (496 lesions) who underwent angiographically successful IVUS-guided stenting. Five IVUS criteria were studied: (1) intrastent minimal lumen cross-sectional area (ISMLCSA) > or =9 mm2; (2) ISMLCSA (> or =9 mm2 and > or =80% of average reference lumen cross-sectional area [CSA]); (3) ISMLCSA > or =90% of average reference lumen CSA; (4) ISMLCSA > or =90% of distal reference lumen CSA; and (5) ISMLCSA > or =55% of average reference vessel CSA. These criteria were met in 33%, 29%, 68%, 82%, and 69% of lesions, respectively. Angiographic follow-up was performed in 335 of 421 eligible patients (80%) at 5.3 +/- 2.7 months. An absolute ISMLCSA > or =9 mm2 was associated with the lowest restenosis, but this criterion was primarily achieved in large vessels. The only criterion that was associated with higher probability of freedom from restenosis independently from vessel size was an ISMLCSA > or =55% of average reference vessel CSA. Therefore, when IVUS is used to guide stent implantation an effort should be made to achieve the largest lumen safely possible. An ISMLCSA > or =55% of the average reference vessel CSA seems to be the most appropriate criterion in terms of frequency of achievement and in terms of increasing the probability of freedom from restenosis.

  1. Renal denervation by intravascular ultrasound: Preliminary in vivo study

    NASA Astrophysics Data System (ADS)

    Sinelnikov, Yegor; McClain, Steve; Zou, Yong; Smith, David; Warnking, Reinhard

    2012-10-01

    Ultrasound denervation has recently become a subject of intense research in connection with the treatment of complex medical conditions including neurological conditions, development of pain management, reproduction of skin sensation, neuropathic pain and spasticity. The objective of this study is to investigate the use of intravascular ultrasound to produce nerve damage in renal sympathetic nerves without significant injury to the renal artery. This technique may potentially be used to treat various medical conditions, such as hypertension. The study was approved by the Institutional Animal Care and Use Committee. Ultrasound was applied to renal nerves of the swine model for histopathological evaluation. Therapeutic ultrasound energy was delivered circumferentially by an intravascular catheter maneuvered into the renal arteries. Fluoroscopic imaging was conducted pre-and post-ultrasound treatment. Animals were recovered and euthanized up to 30 hours post procedure, followed by necropsy and tissue sample collection. Histopathological examination showed evidence of extensive damage to renal nerves, characterized by nuclear pyknosis, hyalinization of stroma and multifocal hemorrhages, with little or no damage to renal arteries. This study demonstrates the feasibility of intravascular ultrasound as a minimally invasive renal denervation technique. Further studies are necessary to evaluate the long-term safety and efficacy of this technique and its related clinical significance.

  2. 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.

    PubMed

    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.

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

    PubMed

    Carlier, Stéphane; Didday, Rich; Slots, Tristan; Kayaert, Peter; Sonck, Jeroen; El-Mourad, Mike; Preumont, Nicolas; Schoors, Dany; Van Camp, Guy

    2014-06-01

    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.

  4. Automatic quantification and characterization of coronary atherosclerosis with computed tomography coronary angiography: cross-correlation with intravascular ultrasound virtual histology.

    PubMed

    de Graaf, Michiel A; Broersen, Alexander; Kitslaar, Pieter H; Roos, Cornelis J; Dijkstra, Jouke; Lelieveldt, Boudewijn P F; Jukema, J Wouter; Schalij, Martin J; Delgado, Victoria; Bax, Jeroen J; Reiber, Johan H C; Scholte, Arthur J

    2013-06-01

    Plaque constitution on computed tomography coronary angiography (CTA) is associated with prognosis. At present only visual assessment of plaque constitution is possible. An accurate automatic, quantitative approach for CTA plaque constitution assessment would improve reproducibility and allows higher accuracy. The present study assessed the feasibility of a fully automatic and quantitative analysis of atherosclerosis on CTA. Clinically derived CTA and intravascular ultrasound virtual histology (IVUS VH) datasets were used to investigate the correlation between quantitatively automatically derived CTA parameters and IVUS VH. A total of 57 patients underwent CTA prior to IVUS VH. First, quantitative CTA quantitative computed tomography (QCT) was performed. Per lesion stenosis parameters and plaque volumes were assessed. Using predefined HU thresholds, CTA plaque volume was differentiated in 4 different plaque types necrotic core (NC), dense calcium (DC), fibrotic (FI) and fibro-fatty tissue (FF). At the identical level of the coronary, the same parameters were derived from IVUS VH. Bland-Altman analyses were performed to assess the agreement between QCT and IVUS VH. Assessment of plaque volume using QCT in 108 lesions showed excellent correlation with IVUS VH (r = 0.928, p < 0.001) (Fig. 1). The correlation of both FF and FI volume on IVUS VH and QCT was good (r = 0.714, p < 0.001 and r = 0.695, p < 0.001 respectively) with corresponding bias and 95 % limits of agreement of 24 mm(3) (-42; 90) and 7.7 mm(3) (-54; 70). Furthermore, NC and DC were well-correlated in both modalities (r = 0.523, p < 0.001) and (r = 0.736, p < 0.001). Automatic, quantitative CTA tissue characterization is feasible using a dedicated software tool. Fig. 1 Schematic illustration of the characterization of coronary plaque on CTA: cross-correlation with IVUS VH. First, the 3-dimensional centerline was generated from the CTA data set using an automatic tree extraction algorithm (Panel I). Using

  5. Automatic quantification and characterization of coronary atherosclerosis with computed tomography coronary angiography: cross-correlation with intravascular ultrasound virtual histology.

    PubMed

    de Graaf, Michiel A; Broersen, Alexander; Kitslaar, Pieter H; Roos, Cornelis J; Dijkstra, Jouke; Lelieveldt, Boudewijn P F; Jukema, J Wouter; Schalij, Martin J; Delgado, Victoria; Bax, Jeroen J; Reiber, Johan H C; Scholte, Arthur J

    2013-06-01

    Plaque constitution on computed tomography coronary angiography (CTA) is associated with prognosis. At present only visual assessment of plaque constitution is possible. An accurate automatic, quantitative approach for CTA plaque constitution assessment would improve reproducibility and allows higher accuracy. The present study assessed the feasibility of a fully automatic and quantitative analysis of atherosclerosis on CTA. Clinically derived CTA and intravascular ultrasound virtual histology (IVUS VH) datasets were used to investigate the correlation between quantitatively automatically derived CTA parameters and IVUS VH. A total of 57 patients underwent CTA prior to IVUS VH. First, quantitative CTA quantitative computed tomography (QCT) was performed. Per lesion stenosis parameters and plaque volumes were assessed. Using predefined HU thresholds, CTA plaque volume was differentiated in 4 different plaque types necrotic core (NC), dense calcium (DC), fibrotic (FI) and fibro-fatty tissue (FF). At the identical level of the coronary, the same parameters were derived from IVUS VH. Bland-Altman analyses were performed to assess the agreement between QCT and IVUS VH. Assessment of plaque volume using QCT in 108 lesions showed excellent correlation with IVUS VH (r = 0.928, p < 0.001) (Fig. 1). The correlation of both FF and FI volume on IVUS VH and QCT was good (r = 0.714, p < 0.001 and r = 0.695, p < 0.001 respectively) with corresponding bias and 95 % limits of agreement of 24 mm(3) (-42; 90) and 7.7 mm(3) (-54; 70). Furthermore, NC and DC were well-correlated in both modalities (r = 0.523, p < 0.001) and (r = 0.736, p < 0.001). Automatic, quantitative CTA tissue characterization is feasible using a dedicated software tool. Fig. 1 Schematic illustration of the characterization of coronary plaque on CTA: cross-correlation with IVUS VH. First, the 3-dimensional centerline was generated from the CTA data set using an automatic tree extraction algorithm (Panel I). Using

  6. Intravascular Ultrasound and Angiographic Predictors of In-Stent Restenosis of Chronic Total Occlusion Lesions

    PubMed Central

    Kang, Jeehoon; Cho, Young-Seok; Kim, Seong-Wook; Park, Jin Joo; Yoon, Yeonyee E.; Oh, Il-Young; Yoon, Chang-Hwan; Suh, Jung-Won; Youn, Tae-Jin; Chae, In-Ho; Choi, Dong-Ju

    2015-01-01

    Despite the benefits of successful percutaneous coronary interventions (PCIs) for chronic total occlusion (CTO) lesions, PCIs of CTO lesions still carry a high rate of adverse events, including in-stent restenosis (ISR). Because previous reports have not specifically investigated the intravascular ultrasound (IVUS) predictors of ISR in CTO lesions, we focused on these predictors. We included 126 patients who underwent successful PCIs, using drug-eluting stents, and post-PCI IVUS of CTO lesions. Patient and lesion characteristics were analyzed to elucidate the ISR predictors. In each lesion, an average of 1.7 ± 0.7 (mean length, 46.4 ± 20.3 mm) stents were used. At 9 months follow-up, 14 (11%) patients demonstrated ISR, and 8 (6.3%) underwent target lesion revascularization. Multivariate logistic regression analysis showed that the independent predictors of ISR were the post-PCI minimal luminal diameter (MLD) and the stent expansion ratio (SER; minimal stent cross-sectional area (CSA) over the nominal CSA of the implanted stent), measured using quantitative coronary angiography (QCA) and IVUS, respectively. A receiver operating characteristic analysis indicated that the best post-PCI MLD and SER cut-off values for predicting ISR were 2.4 mm (area under the curve [AUC], 0.762; 95% confidence interval (CI), 0.639–0.885) and 70% (AUC, 0.714; 95% CI, 0.577–0.852), respectively. Lesions with post-PCI MLD and SER values less than these threshold values were at a higher risk of ISR, with an odds ratio of 23.3 (95% CI, 2.74–198.08), compared with lesions having larger MLD and SER values. Thus, the potential predictors of ISR, after PCI of CTO lesions, are the post-PCI MLD and SER values. The ISR rate was highest in lesions with a post-PCI MLD ≤2.4 mm and an SER ≤70%. PMID:26465755

  7. Integrated intravascular optical coherence tomography ultrasound imaging system

    NASA Astrophysics Data System (ADS)

    Yin, Jiechen; Yang, Hao-Chung; Li, Xiang; Zhang, Jun; Zhou, Qifa; Hu, Changhong; Shung, K. Kirk; Chen, Zhongping

    2010-01-01

    We report on a dual-modality optical coherence tomography (OCT) ultrasound (US) system for intravascular imaging. To the best of our knowledge, we have developed the first integrated OCT-US probe that combines OCT optical components with an US transducer. The OCT optical components mainly consist of a single-mode fiber, a gradient index lens for light-beam focusing, and a right-angled prism for reflecting light into biological tissue. A 40-MHz piezoelectric transducer (PZT-5H) side-viewing US transducer was fabricated to obtain the US image. These components were integrated into a single probe, enabling both OCT and US imaging at the same time. In vitro OCT and ultrasound images of a rabbit aorta were obtained using this dual-modality imaging system. This study demonstrates the feasibility of an OCT-US system for intravascular imaging, which is expected to have a prominent impact on early detection and characterization of atherosclerosis.

  8. Better Diagnosis of Functionally Significant Intermediate Sized Narrowings Using Intravascular Ultrasound-Minimal Lumen Area and Coronary Computed Tomographic Angiography-Based Myocardial Segmentation.

    PubMed

    Kang, Soo-Jin; Yang, Dong Hyun; Kweon, Jihoon; Kim, Young-Hak; Lee, June-Goo; Jung, Joonho; Kim, Namkug; Mintz, Gary S; Kang, Joon-Won; Lim, Tae-Hwan; Park, Seong-Wook

    2016-04-15

    Lesion morphology poorly predicts functional significance of intermediate coronary artery stenosis. The aim of this study was to determine whether a coronary artery-based myocardial segmentation method that quantifies subtended myocardium can improve the diagnostic accuracy of intravascular ultrasound (IVUS)-derived parameters for detecting ischemia-producing lesions. Coronary computed tomography angiography, IVUS, and fractional flow reserve (FFR) data were analyzed in 101 non-left main lesions (20% to 80% angiographic stenosis). Using the coronary artery-based myocardial segmentation method, total left ventricular myocardial volume (Vtotal), myocardial volume subtended by the stenotic coronary segment (Vsub), and Vratio (the ratio of the Vsub to the Vtotal) were assessed. Both Vsub >30.7 cm(3) and Vratio >25.4% were determinants of FFR ≤0.75 (area under the curve = 0.696 and 0.744). Overall, an IVUS-measured minimum lumen area (IVUS-MLA) ≤2.83 mm(2) predicted FFR ≤0.75 with a sensitivity 88% and specificity 73%. Among lesions with IVUS-MLA ≤2.83 mm(2) and FFR >0.75, 89% showed Vsub <30.7 cm(3). In 50 lesions with Vsub >30.7 cm(3), an IVUS-MLA ≤2.85 mm(2) predicted FFR ≤0.75 with sensitivity 85%, specificity 92%, positive predictive value 92%, and negative predictive value 85%. Conversely, in 51 lesions with a Vsub ≤30.7 cm(3), IVUS-MLA ≤2.67 mm(2) showed sensitivity 100%, specificity 69%, positive predictive value 38%, and negative predictive value 100% for predicting FFR ≤0.75. Body surface area, reference lumen diameter, and vessel area had modest correlations with Vsub. In those lesion subsets, IVUS-MLA ≈2.8 mm(2) accurately predicted an FFR ≤0.75, whereas the clinical relevance of assessing and treating lesions with a smaller myocardial territory may be limited (ClinicalTrials.gov number NCT1696006).

  9. Image-based dosimetry of an implanted radioactive stent using intravascular ultrasound

    NASA Astrophysics Data System (ADS)

    Peterson, Stephen W.

    Angioplasty has become an increasingly popular and effective treatment for heart disease. Unfortunately, restenosis, a cellular and biological reaction to the procedure, has hindered its effectiveness. Two of the most successful methods of inhibiting restenosis are radiation and stents. The combination of these two components, radioactive stents, is not as common as some of the other methods, yet still has potential of slowing restenosis. Investigation into source characteristics and artery wall radiobiology may illuminate some possible solutions to the problems of restenosis. This work has developed a calculational method to look at in-vivo images of implanted stents and determine the dose to the artery walls in order to test different source characteristics. The images are Intravascular Ultrasound (IVUS) cross-sectional slices of the stent and the artery. From these images, it is possible to determine the implanted stent structure. The pieces of the stent are identified in the images and modeled in a Monte Carlo simulation, using MCNP4c3. The simulation results were combined with the images to give three-dimensional absolute dose contours of the stent. The absolute dose values were verified using radiochromic film and 198Au-plated stents. This work was able to successfully verify the dose results and create a three-dimensional dose map of the implanted stent.

  10. Long-term outcomes of intravascular ultrasound-guided implantation of bare metal stents versus drug-eluting stents in primary percutaneous coronary intervention

    PubMed Central

    Cho, Yun-Kyeong; Park, Nam-Hee; Choi, Sang-Woong; Sohn, Ji-Hyun; Cho, Hyun-Ok; Park, Hyoung-Seob; Yoon, Hyuck-Jun; Kim, Hyungseop; Nam, Chang-Wook; Kim, Yoon-Nyun; Kim, Kwon-Bae

    2014-01-01

    Background/Aims While drug-eluting stents (DESs) have shown favorable outcomes in ST-segment elevation myocardial infarction (STEMI) compared to bare metal stents (BMSs), there are concerns about the risk of stent thrombosis (ST) with DESs. Because intravascular ultrasound (IVUS) guidance may help optimize stent placement and improve outcomes in percutaneous coronary intervention (PCI) patients, we evaluated the impact of IVUS-guided BMS versus DES implantation on long-term outcomes in primary PCI. Methods In all, 239 STEMI patients received DES (n = 172) or BMS (n = 67) under IVUS guidance in primary PCI. The 3-year incidence of major adverse cardiac events (MACEs) including death, myocardial infarction (MI), target vessel revascularization (TVR), and ST was evaluated. Results There was no difference in all cause mortality or MI. However, the incidence of TVR was 23.9% with BMS versus 9.3% with DES (p = 0.005). Thus, the number of MACEs was significantly lower with DES (11.0% vs. 29.9%; p = 0.001). The incidence of definite or probable ST was not different (1.5% vs. 2.3%; p = 1.0). IVUS-guided DES implantation (hazard ratio [HR], 0.25; 95% confidence interval [CI], 0.08 to 0.78; p = 0.017), stent length (HR, 1.03; 95% CI, 1.00 to 1.06; p = 0.046), and multivessel disease (HR, 3.01; 95% CI, 1.11 to 8.15; p = 0.030) were independent predictors of MACE. Conclusions In patients treated with primary PCI under IVUS guidance, the use of DES reduced the incidence of 3-year TVR versus BMS. However, all cause mortality and MI were similar between the groups. The incidence of ST was low in both groups. PMID:24574835

  11. Diagnostic Performance of Intravascular Ultrasound-Derived Minimal Lumen Area to Predict Functionally Significant Non-Left Main Coronary Artery Disease: a Meta-Analysis

    PubMed Central

    Shin, Ho-Cheol; Bae, Jong Seok; Jin, Han-Young; Seo, Jeong-Sook; Yang, Tae-Hyun; Kim, Dae-Kyeong; Cho, Kyoung-Im; Kim, Bo-Hyun; Park, Yong Hyun; Je, Hyung-Gon; Kim, Dong-Soo

    2016-01-01

    Background and Objectives Intravascular ultrasound (IVUS)-guided percutaneous coronary intervention frequently results in unnecessary stenting due to the low positive predictive value of IVUS-derived minimal lumen area (MLA) for identification of functionally significant coronary stenosis. We appraised the diagnostic accuracy of IVUS-derived MLA compared with the fractional flow reserve (FFR) to assess intermediate coronary stenosis. Subjects and Methods We searched MEDLINE and Cochrane databases for studies using IVUS and FFR methods to establish the best MLA cut-off values to predict significant non-left main coronary artery stenosis. Summary estimates were obtained using a random-effects model. Results The 17 studies used in our analysis enrolled 3920 patients with 4267 lesions. The weighted overall mean MLA cut-off value was 2.58 mm2. The pooled MLA sensitivity that predicted functionally significant coronary stenosis was 0.75 (confidence interval [CI]: 0.72 to 0.77) and the specificity was 0.66 (CI: 0.64 to 0.68). The positive likelihood ratio (LR) was 2.33 (CI: 2.06 to 2.63) and LR (-) was 0.33 (CI: 0.26 to 0.42). The pooled diagnostic odds ratio (DOR) was 7.53 (CI: 5.26 to 10.76) and the area under the summary receiver operating characteristic curve for all the trials was 0.782 with a Q point of 0.720. Meta-regression analysis demonstrated that an FFR cut-off point of 0.75 was associated with a four times higher diagnostic accuracy compared to that of 0.80 (relative DOR: 3.92; 95% CI: 1.25 to 12.34). Conclusion IVUS-derived MLA has limited diagnostic accuracy and needs careful interpretation to correlate with functionally significant non-left main coronary artery stenosis. PMID:27721852

  12. Chronic vascular response after self-expanding nitinol stent implantation in superficial femoral arteries: a serial intravascular ultrasound analysis.

    PubMed

    Nishimura, Machiko; Fujii, Kenichi; Fukunaga, Masashi; Kawasaki, Daizo; Miki, Kojiro; Saita, Ten; Horimatsu, Tetsuo; Tamaru, Hiroto; Imanaka, Takahiro; Naito, Yoshiro; Masuyama, Tohru

    2016-10-01

    The mechanical properties of the self-expanding nitinol stents (SENS) and chronic biological stimulation on the wall from the SENS have not been fully investigated. This study evaluated the mechanical vascular response to SENS implantation in superficial femoral artery (SFA) lesions using serial volumetric intravascular ultrasound (IVUS). Twenty-five symptomatic patients due to de novo SFA lesions scheduled for SENS placement were prospectively enrolled. Serial IVUS studies were performed immediately after crossing with a guidewire, immediately after the procedure, and at a 8-month follow-up. Serial IVUS volumetric analysis was conducted after stent deployment and at follow-up. Mean stent, lumen and neointimal areas were calculated as the volume divided by the stent length, and the calcium arc was measured. At follow-up, SENS had increased 40.6 % in overall volume. The chronic stent expansion tended to be larger, and the mean neointimal area at the 8-month follow-up was significantly larger in less calcified lesions compared to heavily calcified lesions. As a result, the mean late lumen area loss was significantly larger in lesions with calcium arcs of 0° and in the first and second quadrants than in those with calcium arcs in the third and fourth quadrants (2.8 ± 7.2, 1.3 ± 5.6, 0.6 ± 5.9, 1.2 ± 5.4, -0.8 ± 5.2 mm(2), respectively; p < 0.001). SENSs continued to enlarge with intimal proliferation over 8 months in all lesions. Although arterial calcium affected the degree of chronic stent expansion during the follow-up period, neointimal proliferation was smaller in heavily calcified lesion compared to less calcified lesion following SENS implantation.

  13. Endoscopic ultrasound-guided intravascular therapy.

    PubMed

    Binmoeller, Kenneth F; Sendino, Oriol; Kane, Steven D

    2015-01-01

    The gastrointestinal tract provides a unique "window" to access vascular structures in the mediastinum and abdomen. The advent of interventional endoscopic ultrasound (EUS) has enabled access to these structures with a standard fine-needle aspiration (FNA) needle. Sclerosants, cyanoacrylate, and coils can be delivered through the lumen of the FNA needle. EUS-guided treatment of gastric varices has theoretical advantages over conventional endoscopy-guided treatment. Controlled studies are needed to determine the role of EUS-guided treatment for primary and secondary prevention of variceal bleeding. There is a growing list of novel indications for EUS-guided vascular therapy that include portal vein angiography and pressure measurements, intrahepatic portosystemic shunt placement, and micro coil embolization of vascular structures. Additionally, access and therapy of the heart and surrounding structures appears feasible. PMID:25366271

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

    PubMed

    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 < 0.01). However, the NC in ISR lesions after SES implantation was covered with a thick fibrous cap. An increase in the size of NC covered with a thick fibrous cap is a characteristic morphological feature of ISR after SES implantation. Further studies are needed to clarify whether such a morphological change is related to the attenuation of stent thrombosis after SES implantation.

  15. Radiofrequency-intravascular ultrasound assessment of lesion coverage after angiography-guided emergent percutaneous coronary intervention in patients with non-ST elevation myocardial infarction.

    PubMed

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

    2013-12-15

    Using radiofrequency-intravascular ultrasound (VH-IVUS), we have previously demonstrated that in 50% of patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention with optimal angiographic result, the stent does not fully cover the whole VH-IVUS-derived thin-cap fibroatheroma (VH-TCFA) related to the culprit lesion. Presently, we set out to extend these findings to 20 patients with non-STEMI with Thrombolysis In Myocardial Infarction flow 3 in the infarct-related artery before intervention who were then treated with angiography-guided direct stent implantation. The lesion was imaged with VH-IVUS before and after intervention, but the results were blinded to the operator. Plaque rupture site was identified in 8 lesions (40%), all proximal to the minimum lumen area (MLA) site. The maximum necrotic core site was found proximal to MLA in 18 lesions and at the MLA in 2 lesions. Although the plaque rupture site was fully covered with the stent in all lesions, an uncovered VH-TCFA was found in 7 lesions (35%), 4 in the proximal reference segment, 1 in the distal reference segment, and 2 in both the proximal and distal reference segments. In conclusion, in 35% of patients with non-STEMI undergoing angiography-guided emergent percutaneous coronary intervention, the stent does not fully cover a VH-TCFA related to the culprit lesion.

  16. Intravascular ultrasound area strain imaging used to characterize tissue components and assess vulnerability of atherosclerotic plaques in a rabbit model.

    PubMed

    Hu, Xiao-Bo; Zhang, Peng-Fei; Su, Hai-Jun; Yi, Xin; Chen, Liang; Rong, Yuan-Yuan; Zhang, Ke; Li, Xuan; Wang, Lin; Sun, Chun-Li; Cai, Xiao-Jun; Li, Li; Song, Jian-Tao; Dai, Xiao-Min; Sui, Xiao-Di; Zhang, Yun; Zhang, Mei

    2011-10-01

    The purpose of this study was to investigate the association of area strain and tissue components and vulnerability of atherosclerotic plaques in a rabbit model. Forty purebred New Zealand rabbits underwent balloon-induced abdominal aorta endothelium injury, then a high-cholesterol diet for 24 weeks. Intravascular ultrasound (IVUS) images of abdominal aortas were acquired in situ and two consecutive frames near the end-diastole were used to construct an IVUS elastogram. Histologic slices matched with corresponding IVUS images were stained for fatty and collagen components, smooth muscle cells (SMCs) and macrophages. Regions-of-interest (ROIs) in plaques were classified as fibrous, fibro-fatty or fatty according to histologic study. Vulnerability indexes of ROIs were calculated as (fat + macrophage)/(collagen + SMCs). The area strain of these ROIs was calculated by use of an in-house-designed software system with a block-matching-based algorithm. Area strain was significantly higher in fatty ROIs (0.056 ± 0.003) than in fibrous (0.019 ± 0.002, p < 0.001) or fibro-fatty ROIs (0.033 ± 0.003, p < 0.001). The sensitivity and specificity of area strain for fatty ROIs characterization was 75.0% and 80.2% (area under the curve [AUC] 0.858, 95% confidence interval [CI] = 0.800-0.916, p < 0.001) and 75.0% and 75.3% (AUC 0.859, 95% CI = 0.801-0.917, p < 0.001) for fibrous ROIs, as demonstrated by receiver operating characteristic curve analysis. Area strain was positively correlated with vulnerability index (r(2) = 0.495, p < 0.001), fatty components (r(2) = 0.332, p < 0.001) and macrophage infiltration (r(2) = 0.406, p < 0.001); and negatively correlated with collagen and SMC composition (r(2) = 0.115 and r(2) = 0.169, p < 0.001, respectively). Area strain calculation with IVUS elastography based on digital B-mode analysis is feasible and can be useful for tissue characterization and plaque vulnerability assessment. PMID:21856069

  17. Computerized methodology for micro-CT and histological data inflation using an IVUS based translation map.

    PubMed

    Athanasiou, Lambros S; Rigas, George A; Sakellarios, Antonis I; Exarchos, Themis P; Siogkas, Panagiotis K; Naka, Katerina K; Panetta, Daniele; Pelosi, Gualtiero; Vozzi, Federico; Michalis, Lampros K; Parodi, Oberdan; Fotiadis, Dimitrios I

    2015-10-01

    A framework for the inflation of micro-CT and histology data using intravascular ultrasound (IVUS) images, is presented. The proposed methodology consists of three steps. In the first step the micro-CT/histological images are manually co-registered with IVUS by experts using fiducial points as landmarks. In the second step the lumen of both the micro-CT/histological images and IVUS images are automatically segmented. Finally, in the third step the micro-CT/histological images are inflated by applying a transformation method on each image. The transformation method is based on the IVUS and micro-CT/histological contour difference. In order to validate the proposed image inflation methodology, plaque areas in the inflated micro-CT and histological images are compared with the ones in the IVUS images. The proposed methodology for inflating micro-CT/histological images increases the sensitivity of plaque area matching between the inflated and the IVUS images (7% and 22% in histological and micro-CT images, respectively). PMID:25771781

  18. Coronary 3D reconstruction using IVUS images only: a numeric phantom investigation

    NASA Astrophysics Data System (ADS)

    Matsumoto, Monica Mitiko Soares; Cardoso, Fernando Mitsuyama; Lemos, Pedro Alves; Furuie, Sergio Shiguemi

    2010-03-01

    Intravascular ultrasound (IVUS) examination offers a tomographic view of the vessel, having the catheter tip as reference. During examination, the catheter is pulled back with a constant speed (0.5 or 1.0 mm/s) and the ultrasound transducer captures cross-sectional slices of the coronary. Currently, 3D IVUS reconstruction is based on single-plane or biplane angiography together with IVUS images. In this work, we present a preliminary approach to reconstruct tridimensionally the catheter path and coronary, based only on IVUS sequence. We have proposed a numeric phantom framework: coronary simulation, catheter dynamic path simulation, IVUS acquisition, reconstruction and validation. Our method infers the catheter path inside the coronary, based on shortest path graph algorithm. To reconstruct morphology, we have associated the catheter path and the position of the frame with smoothness costs, and solved it as a minimization problem. In this experiment we have used three different morphologies (straight, one curve and two curves) and 60 random initializations each for the initial point and angle of catheter insertion. The results for the plane containing the centerline of the catheter were 95.8% true positive and 8.5% false positive rates.

  19. 3D reconstruction of an IVUS transducer trajectory with a single view in cineangiography

    NASA Astrophysics Data System (ADS)

    Jourdain, Melissa; Meunier, Jean; Mongrain, Rosaire; Sherknies, Denis; Weng, Ji Yao; Tardif, Jean-Claude

    2005-04-01

    During an Intravascular Ultrasound(IVUS) intervention, a catheter with an ultrasound transducer is introduced in the body through a blood vessel and then pulled back to image a sequence of vessel cross-sections. Unfortunately, there is no 3D information about the position and orientation of these cross-section planes. To position the IVUS images in space, some researchers have proposed complex stereoscopic procedures relying on biplane angiography to get two X-ray image sequences of the IVUS transducer trajectory along the catheter. We have elaborated a much simpler algorithm to recover the transducer 3D trajectory with only a single view X-ray image sequence. The known pullback distance of the transducer during the IVUS intervention is used as an a priori to perform this task. Considering that biplane system are difficult to operate and rather expensive and uncommon in hospitals; this simple pose estimation algorithm could lead to an affordable and useful tool to better assess the 3D shape of vessels investigated with IVUS

  20. Dual-element needle transducer for intravascular ultrasound imaging

    PubMed Central

    Yoon, Sangpil; Kim, Min Gon; Williams, Jay A.; Yoon, Changhan; Kang, Bong Jin; Cabrera-Munoz, Nestor; Shung, K. Kirk; Kim, Hyung Ham

    2015-01-01

    Abstract. A dual-element needle transducer for intravascular ultrasound imaging has been developed. A low-frequency element and a high-frequency element were integrated into one device to obtain images which conveyed both low- and high-frequency information from a single scan. The low-frequency element with a center frequency of 48 MHz was fabricated from the single crystal form of lead magnesium niobate-lead titanate solid solution with two matching layers (MLs) and the high frequency element with a center frequency of 152 MHz was fabricated from lithium niobate with one ML. The measured axial and lateral resolutions were 27 and 122  μm, respectively, for the low-frequency element, and 14 and 40  μm, respectively, for the high-frequency element. The performance of the dual-element needle transducer was validated by imaging a tissue-mimicking phantom with lesion-mimicking area, and ex vivo rabbit aortas in water and rabbit whole blood. The results suggest that a low-frequency element effectively provides depth resolved images of the whole vessel and its adjacent tissue, and a high-frequency element visualizes detailed structure near the surface of the lumen wall in the presence of blood within the lumen. The advantages of a dual-element approach for intravascular imaging are also discussed. PMID:26158118

  1. A comparative approach of four different image registration techniques for quantitative assessment of coronary artery calcium lesions using intravascular ultrasound.

    PubMed

    Araki, Tadashi; Ikeda, Nobutaka; Dey, Nilanjan; Chakraborty, Sayan; Saba, Luca; Kumar, Dinesh; Godia, Elisa Cuadrado; Jiang, Xiaoyi; Gupta, Ajay; Radeva, Petia; Laird, John R; Nicolaides, Andrew; Suri, Jasjit S

    2015-02-01

    In IVUS imaging, constant linear velocity and a constant angular velocity of 1800 rev/min causes displacement of the calcium in subsequent image frames. To overcome this error in intravascular ultrasound video, IVUS image frames must be registered prior to the lesion quantification. This paper presents a comprehensive comparison of four registration methods, namely: Rigid, Affine, B-Splines and Demons on five set of calcium lesion quantification parameters namely: (i) the mean lesion area, (ii) mean lesion arc, (iii) mean lesion span, (iv) mean lesion length, and (v) mean lesion distance from catheter. Using our IRB approved data of 100 patient volumes, our results shows that all four registrations showed a decrease in five calcium lesion parameters as follows: for Rigid registration, the values were: 4.92%, 5.84%, 5.89%, 5.27%, and 4.57%, respectively, for Affine registration the values were: 6.06%, 6.51%, 7.28%, 6.50%, and 5.94%, respectively, for B-Splines registration the values were: 7.35%, 8.03%, 9.54%, 8.18%, and 7.62%, respectively, and for Demons registration the five parameters were 7.32%, 8.02%, 10.11%, 7.94%, and 8.92% respectively. The relative overlap of identified lesions decreased by 5.91% in case of Rigid registration, 6.23% in case of Affine registration, 4.48% for Demons registration, whereas it increased by 3.05% in case of B-Splines registration. Rigid and Affine transformation-based registration took only 0.1936 and 0.2893 s per frame, respectively. Demons and B-Splines framework took only 0.5705 and 0.9405 s per frame, respectively, which were significantly slower than Rigid and Affine transformation based image registration. PMID:25523233

  2. Plaque development, vessel curvature, and wall shear stress in coronary arteries assessed by X-ray angiography and intravascular ultrasound

    PubMed Central

    Wahle, Andreas; Lopez, John J.; Olszewski, Mark E.; Vigmostad, Sarah C.; Chandran, Krishnan B.; Rossen, James D.; Sonka, Milan

    2008-01-01

    The relationships among vascular geometry, hemodynamics, and plaque development in the coronary arteries are complex and not yet well understood. This paper reports a methodology for the quantitative analysis of in vivo coronary morphology and hemodynamics, with particular emphasis placed on the critical issues of image segmentation and the automated classification of disease severity. We were motivated by the observation that plaque more often developed at the inner curvature of a vessel, presumably due to the relatively lower wall shear stress at these locations. The presented studies are based on our validated methodology for the three-dimensional fusion of intravascular ultrasound (IVUS) and X-ray angiography, introducing a novel approach for IVUS segmentation that incorporates a robust, knowledge-based cost function and a fully optimal, three-dimensional segmentation algorithm. Our first study shows that circumferential plaque distribution depends on local vessel curvature in the majority of vessels. The second study analyzes the correlation between plaque distribution and wall shear stress in a set of 48 in vivo vessel segments. The results were conclusive for both studies, with a stronger correlation of circumferential plaque thickness with local curvature than with wall shear stress. The inverse relationship between local wall shear stress and plaque thickness was significantly more pronounced (p < 0.025) in vessel cross sections exhibiting compensatory enlargement (positive remodeling) without luminal narrowing than when the full spectrum of disease severity was considered. The inverse relationship was no longer observed in vessels where less than 35% of vessel cross sections remained without luminal narrowing. The findings of this study confirm, in vivo, the hypothesis that relatively lower wall shear stress is associated with early plaque development. PMID:16644262

  3. The Intravascular Ultrasound Elasticity-Palpography Technique Revisited: A Reliable Tool for the in vivo Detection of Vulnerable Coronary Atherosclerotic Plaques

    PubMed Central

    Deleaval, Flavien; Bouvier, Adeline; Finet, Gérard; Cloutier, Guy; Yazdani, Saami K.; Le Floc’h, Simon; Clarysse, Patrick; Pettigrew, Roderic I.; Ohayon, Jacques

    2016-01-01

    A critical key in detection of vulnerable plaques (VPs) is the quantification of its mechanical properties. From the intravascular ultrasound (IVUS) echogram and strain images, Céspedes et al. (2000) proposed an elasticity-palpography technique (E-PT) to estimate the apparent stress-strain modulus (S-SM) palpogram of the thick endoluminal layer of the arterial wall. However, this approach suffers from major limitations because it was developed for homogeneous, circular and concentric VPs. The present study was therefore designed to improve the E-PT by considering the anatomical shape of the VP. This improved E-PT (IE-PT) was successfully applied to six coronary lesions of patients imaged in vivo with IVUS. Our results demonstrated that the mean relative error of the S-SM decreased from 61.02±9.01% to 15.12±12.57% when considering the IE-PT instead of the E-PT. The accuracy of the S-SM palpograms computed by using the improved theoretical framework was also investigated with regard to noise which may affect prediction of plaque vulnerability. PMID:23727295

  4. Intravascular ultrasound imaging of peripheral arteries as an adjunct to balloon angioplasty and atherectomy.

    PubMed

    Korogi, Y; Hirai, T; Takahashi, M

    1996-01-01

    This article reviews many of the applications of intravascular ultrasound (US) imaging for peripheral arterial diseases. In vitro studies demonstrate an excellent correlation between ultrasound measurements of lumen and plaque cross-sectional area compared with histologic sections. In vivo clinical studies reveal the enhanced diagnostic capabilities of this technology compared with angiography. Intravascular US imaging can provide valuable information on the degree, eccentricity, and histologic type of stenosis before intervention, and on the morphological changes in the arterial wall and the extent of excision after intervention. Intravascular US may also serve as a superior index for gauging the diameter of balloon, stent, laser probe, and/or atherectomy catheter appropriate for a proposed intervention. Significant new insights into the mechanisms of balloon angioplasty and atherectomy have been established by intravascular US findings. Intravascular US imaging has been shown to be a more accurate method than angiography for determining the cross-sectional area of the arterial lumen, and for assessing severity of stenosis. Quantitative assessment of the luminal cross-sectional area after the balloon dilatation should be more accurate than angiography as intimal tears or dissections produced by the dilatation may not be accurately evaluated with angiography. At the present time, intravascular US is still a controversial imaging technique. Outcome studies are currently being organized to assess the clinical value and cost effectiveness of intravascular ultrasound in the context of these interventional procedures. PMID:8653738

  5. Treatment of acute intravascular thrombi with diagnostic ultrasound and intravenous microbubbles.

    PubMed

    Xie, Feng; Lof, John; Everbach, Carr; He, Anming; Bennett, Richard M; Matsunaga, Terry; Johanning, Jason; Porter, Thomas R

    2009-04-01

    The purpose of this study was to determine whether high mechanical index (MI) impulses from diagnostic ultrasound (DUS) could dissolve intravascular thrombi using intravenous microbubbles. Using a canine model, DUS was applied during a continuous intravenous infusion of microbubbles. Completely thrombosed grafts were assigned to 2 treatment regimens: low-MI (<0.5-MI) ultrasound alone; or intermittent high-MI impulses (1.9-MI) guided by low-MI ultrasound (contrast pulse sequencing). A 20-MHz cavitation detector was placed confocal to the ultrasound transducer to make intravascular cavitation measurements in 1 dog. Intravascular cavitational activity was detected when an MI of >0.5 was applied. In grafts treated with intermittent high-MI ultrasound, angiographic success was 71% at 30 min and 79% at 45 min, compared with 20% and 30% at these times in the low-MI ultrasound alone group (p < 0.05). We conclude that a commercially available DUS transducer can successfully recanalize acute intravascular thrombi during a continuous microbubble infusion. PMID:19580735

  6. Intravascular photoacoustic imaging of exogenously labeled atherosclerotic plaque through luminal blood

    PubMed Central

    Yeager, Doug; Karpiouk, Andrei; Wang, Bo; Amirian, James; Sokolov, Konstantin; Smalling, Richard

    2012-01-01

    Abstract. Combined intravascular ultrasound and intravascular photoacoustic (IVUS/IVPA) imaging has been previously established as a viable means for assessing atherosclerotic plaque morphological and compositional characteristics using both endogenous and exogenous contrast. In this study, IVUS/IVPA imaging of atherosclerotic rabbit aortas following systemic injection of gold nanorods (AUNRs) with peak absorbance within the tissue optical window is performed. Ex vivo imaging results reveal a high photoacoustic signal from localized AUNRs in regions with atherosclerotic plaques. Corresponding histological staining further confirms the preferential extravasation of AUNRs in atherosclerotic regions with compromised luminal endothelium and acute inflammation. The ability to detect AUNRs using combined IVUS and photoacoustic imaging in the presence of luminal saline and luminal blood is evaluated using both spectroscopic and single wavelength IVPA imaging techniques. Results demonstrate that AUNR detection within the arterial wall can be achieved using both methods, even in the case of imaging through luminal blood. PMID:23224013

  7. Cardiac phase extraction in IVUS sequences using 1-D Gabor filters.

    PubMed

    Barajas, Joel; Caballero, Karla L; Rodriguez, Oriol; Radeva, Petia

    2007-01-01

    A main issue in the automatic analysis of Intravascular Ultrasound (IVUS) images is the presence of periodic changes provoked by heart motion during the cardiac cycle. Although the Electrocardiogram (ECG) signal can be used to gate the sequence, few IVUS systems incorporate the ECG-gating option, and the synchronization between them implies several issues. In this paper, we present a fast and robust method to assign a phase in the cardiac cycle to each image in the sequence directly from in vivo clinical IVUS sequences. It is based on the assumption that the vessel wall is significantly brighter than the blood in each IVUS beam. To guarantee stability in this assumption, we use normalized reconstructed images. Then, the wall boundary is extracted for all the radial beams in the sequence and a matrix with these positions is formed. This matrix is filtered using a bank of 1-D Gabor filters centered at the predominant frequency of a given number of windows in the sequence. After filtering, we combine the responses to obtain a unique phase within the cardiac cycle for each image. For this study, we gate the sequence to make the sequence comparable with other ones of the same patient. The method is tested with 12 pullbacks of real patients and 15 synthetic tests.

  8. Image Processing in Intravascular OCT

    NASA Astrophysics Data System (ADS)

    Wang, Zhao; Wilson, David L.; Bezerra, Hiram G.; Rollins, Andrew M.

    Coronary artery disease is the leading cause of death in the world. Intravascular optical coherence tomography (IVOCT) is rapidly becoming a promising imaging modality for characterization of atherosclerotic plaques and evaluation of coronary stenting. OCT has several unique advantages over alternative technologies, such as intravascular ultrasound (IVUS), due to its better resolution and contrast. For example, OCT is currently the only imaging modality that can measure the thickness of the fibrous cap of an atherosclerotic plaque in vivo. OCT also has the ability to accurately assess the coverage of individual stent struts by neointimal tissue over time. However, it is extremely time-consuming to analyze IVOCT images manually to derive quantitative diagnostic metrics. In this chapter, we introduce some computer-aided methods to automate the common IVOCT image analysis tasks.

  9. Intraluminal fluorescence spectroscopy catheter with ultrasound guidance

    NASA Astrophysics Data System (ADS)

    Stephens, Douglas N.; Park, Jesung; Sun, Yang; Papaioannou, Thanassis; Marcu, Laura

    2009-05-01

    We demonstrate the feasibility of a time-resolved fluorescence spectroscopy (TRFS) technique for intraluminal investigation of arterial vessel composition under intravascular ultrasound (IVUS) guidance. A prototype 1.8-mm (5.4 Fr) catheter combining a side-viewing optical fiber (SVOF) and an IVUS catheter was constructed and tested with in vitro vessel phantoms. The prototype catheter can locate a fluorophore in the phantom vessel wall, steer the SVOF in place, perform blood flushing under flow conditions, and acquire high-quality TRFS data using 337-nm wavelength excitation. The catheter steering capability used for the coregistration of the IVUS image plane and the SVOF beam produce a guiding precision to an arterial phantom wall site location of 0.53+/-0.16 mm. This new intravascular multimodal catheter enables the potential for in vivo arterial plaque composition identification using TRFS.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. A Review of Intravascular Ultrasound–Based Multimodal Intravascular Imaging: The Synergistic Approach to Characterizing Vulnerable Plaques

    PubMed Central

    Ma, Teng; Zhou, Bill; Hsiai, Tzung K.; Shung, K. Kirk

    2015-01-01

    Catheter-based intravascular imaging modalities are being developed to visualize pathologies in coronary arteries, such as high-risk vulnerable atherosclerotic plaques known as thin-cap fibroatheroma, to guide therapeutic strategy at preventing heart attacks. Mounting evidences have shown three distinctive histopathological features—the presence of a thin fibrous cap, a lipid-rich necrotic core, and numerous infiltrating macrophages—are key markers of increased vulnerability in atherosclerotic plaques. To visualize these changes, the majority of catheter-based imaging modalities used intravascular ultrasound (IVUS) as the technical foundation and integrated emerging intravascular imaging techniques to enhance the characterization of vulnerable plaques. However, no current imaging technology is the unequivocal “gold standard” for the diagnosis of vulnerable atherosclerotic plaques. Each intravascular imaging technology possesses its own unique features that yield valuable information although encumbered by inherent limitations not seen in other modalities. In this context, the aim of this review is to discuss current scientific innovations, technical challenges, and prospective strategies in the development of IVUS-based multi-modality intravascular imaging systems aimed at assessing atherosclerotic plaque vulnerability. PMID:26400676

  12. Monolithic CMUT on CMOS Integration for Intravascular Ultrasound Applications

    PubMed Central

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

    2012-01-01

    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 where the elements need to 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. Experiments on a 1.6 mm diameter dual-ring CMUT array with a 15 MHz center frequency show that both the CMUTs and the integrated CMOS electronics are fully functional. The SNR measurements indicate that the performance is adequate for imaging CTOs located 1 cm away from the CMUT array. PMID:23443701

  13. Fully automatic contour detection in intravascular ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Brusseau, Elisabeth F.; de Korte, Chris L.; Mastik, Fritz; Schaar, Johannes; van der Steen, Anton F.

    2004-04-01

    Segmentation of deformable structures remains a challenging task in ultrasound imaging especially in low signal-to-noise ratio applications. In this paper a fully automatic method, dedicated to the luminal contour segmentation in intracoronary ultrasound imaging is introduced. The method is based on an active contour with a priori properties that evolves according to the statistics of the ultrasound texture brightness, determined as being mainly Rayleigh distributed. However, contrary to classical snake-based algorithms, the presented technique neither requires from the user the pre-selection of a region of interest tight around the boundary, nor parameter tuning. This fully automatic character is achieved by an initial contour that is not set, but estimated and thus adapted to each image. Its estimation combines two statistical criteria extracted from the a posteriori probability, function of the contour position. These criteria are the location of the function maximum (or maximum a posteriori estimator) and the first zero-crossing of the function derivative. Then starting form the initial contour, a region of interest is automatically selected and the process iterated until the contour evolution can be ignored. In vivo coronary images from 15 patients, acquired with a 20 MHz central frequency Jomed Invision ultrasound scanner were segmented with the developed method. Automatic contours were compared to those manually drawn by two physician in terms of mean absolute difference. Results demonstrate that the error between automatic contours and the average of manual ones (0.099+/-0.032mm) and the inter-expert error (0.097+/-0.027mm) are similar and of small amplitude.

  14. Intravascular ultrasound characterization of the "black hole" phenomenon after drug-eluting stent implantation.

    PubMed

    Costa, Marco A; Sabate, Manel; Angiolillo, Dominick J; Jimenez-Quevedo, Pilar; Teirstein, Paul; Carter, Andrew; Leon, Martin B; Moses, Jeffrey; Zenni, Martin; Yakubov, Steven; Guzman, Luis A; Gilmore, Paul; Macaya, Carlos; Bass, Theodore A

    2006-01-15

    An intraluminal echolucent tissue, dubbed "black hole," has been identified by intravascular ultrasonography after intracoronary brachytherapy. This study reports the characteristics and incidence of the black hole in patients treated with drug-eluting stent implantation using a sirolimus-eluting stent (SES). We included intravascular ultrasound data from the Compassionate Use of Sirolimus-Eluting Stent (SECURE, n = 61 lesions) registry, a study involving patients in whom previous brachytherapy had failed, and the DIABETES trial (n = 165 lesions), a multicenter, randomized study comparing SES versus bare metal stents in diabetic patients. Intravascular ultrasound follow-up was scheduled at 8 months (SECURE trial, post-brachytherapy population) and 9 months (DIABETES trial). In the SECURE population, a black hole was observed in 10 patients (19.6%). Seven black hole segments had significant intimal hyperplasia (> 10%). A black hole accounted for 27% of total intraluminal tissue. In the DIABETES trial, 2 patients (2.5%) in the SES group and none in the bare metal stent group showed echolucent intimal hyperplasia. In conclusion, a black hole occurred frequently after implantation of a SES in patients in whom intracoronary brachytherapy had previously failed. Black holes were also identified in a nonirradiated population, although the incidence was lower than in the post-brachytherapy patients. Bare metal stents were not associated with this phenomenon.

  15. Semi-automatic matching of OCT and IVUS images for image fusion

    NASA Astrophysics Data System (ADS)

    Pauly, Olivier; Unal, Gozde; Slabaugh, Greg; Carlier, Stephane; Fang, Tong

    2008-03-01

    Medical imaging is essential in the diagnosis of atherosclerosis. In this paper, we propose the semi-automatic matching of two promising and complementary intravascular imaging techniques, Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT), with the ultimate goal of producing hybrid images with increased diagnostic value for assessing arterial health. If no ECG gating has been performed on the IVUS and OCT pullbacks, there is typically an anatomical shuffle (displacement in time and space) in the image sequences due to the catheter motion in the artery during the cardiac cycle, and thus, this is not possible to perform a 3D registration. Therefore, the goal of our work is to detect semi-automatically the corresponding images in both modalities as a preprocessing step for the fusion. Our method is based on the characterization of the lumen shape by a set of Gabor Jets features. We also introduce different correction terms based on the approximate position of the slice in the artery. Then we train different support vector machines based on these features to recognize these correspondences. Experimental results demonstrate the usefulness of our approach, which achieves up to 95% matching accuracy for our data.

  16. High-resolution coregistered intravascular imaging with integrated ultrasound and optical coherence tomography probe

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Yin, Jiechen; Hu, Changhong; Zhou, Qifa; Shung, K. Kirk; Chen, Zhongping

    2010-09-01

    We report an integrated ultrasound (US) and optical coherence tomography (OCT) probe and system for intravascular imaging. The dual-function probe is based on a 50 MHz focused ring US transducer, with a centric hole for mounting OCT probe. The coaxial US and light beams are steered by a 45° mirror to enable coregistered US/OCT imaging simultaneously. Lateral resolution of US is improved due to focused ultrasonic beam. Mirror effects on US were investigated and in vitro imaging of a rabbit aorta has been carried out. The combined US-OCT system demonstrated high resolution in visualizing superficial arterial structures while retaining deep penetration of ultrasonic imaging.

  17. [Clinical Application of Extraction and Analysis of the Key Frames Based on IVUS Sequences].

    PubMed

    Mao, Haiqun; Yang, Feng; Huang, Zheng; Cui, Kai; Wang, Xinxin

    2015-08-01

    In this paper, we propose an image-based key frame gating method to reduce motion artifacts in intravascular ultrasound (IVUS) longitudinal cuts. The artifacts are mainly caused by the periodic relative displacement between blood vessels and the IVUS catheter due to cardiac motion. The method is achieved in four steps as following. Firstly, we convert IVUS image sequences to polar coordinates to cut down the amount of calculation. Secondly, we extracted a one-dimensional signal cluster reflecting cardiac motion by spectral analysis and filtering techniques. Thirdly, we designed a Butterworth band-pass filter for filtering the one-dimensional signal clusters. Fourthly, we retrieved the extremes of the filtered signal clusters to seek key frames to compose key-frames gated sequences. Experimental results showed that our algorithm was fast and the average frame processing time was 17ms. Observing the longitudinal viewpictures, we found that comparing to the original ones, the gated sequences had similar trend, less saw tooth shape, and good continuity. We selected 12 groups of clinical IVUS sequences [images (876 +/- 65 frames), coronary segments length (14.61 +/- 1.08 mm)] to calculate vessel volume, lumen volume, mean plaque burden of the original and gated sequences. Statistical results showed that, on one hand, both vessel volume and lumen volume measured of the gated sequences were significantly smaller than those of the original ones, and there was no significant difference on mean plaque burden between original and gated sequences, which met the need of the clinical diagnosis and treatment. On the other hand, variances of vessel area and lumen area of the gated sequences were significantly smaller than those of the original sequences, indicating that the gated sequences would be more stable than the original ones.

  18. Evaluation of combined near-IR spectroscopic (NIRS)-IVUS imaging as a means to detect lipid-rich plaque burden in human coronary autopsy specimens

    NASA Astrophysics Data System (ADS)

    Su, Jimmy L.; Grainger, Stephanie J.; Greiner, Cherry A.; Hendricks, Michael J.; Goode, Meghan M.; Saybolt, Matthew D.; Wilensky, Robert L.; Madden, Sean P.; Muller, James E.

    2016-02-01

    Intracoronary near-infrared spectroscopy (NIRS) can identify lipid in the coronary arteries, but lacks depth resolution. A novel catheter is currently in clinical use that combines NIRS with intravascular ultrasound (IVUS), which provides depth-resolved structural information via the IVUS modality. A measure designated as lipid-rich plaque burden (LRPB) has been proposed as a means to interpret the combined acoustic and optical information of NIRS-IVUS. LRPB is defined as the area created by the intersection of the NIRS lipid-rich arc with the corresponding IVUS-measured plaque burden. We determined the correlation in human coronary autopsy specimens between LRPB, a measure of lipid presence and extent available via intravascular imaging in patients, and the area of lipid-rich plaque as determined by the gold-standard of histology. Fifteen artery segments from 8 human autopsy hearts were imaged with the NIRS-IVUS system (TVC Imaging System, Infraredx Inc., Burlington, MA). Arteries were imaged in a specialty fixture that assured accurate co-registration between imaging and histology. The arteries were then fixed and divided into 2 mm blocks for histological staining. Pathological contouring of lipid-rich areas was performed on the stained thin sections for 54 lipid-rich blocks. Computation of LRPB was performed on transverse NIRS-IVUS frames corresponding to the histologic sections. The quantified LRPB was frequently higher than the lipid-rich plaque area determined by histology, because the region denoted by the EEL and lumen within the NIRS lipid-rich arc is not entirely comprised of lipid. Overall, a moderate to strong correlation (R = 0.73) was found between LRPB determined by NIRS-IVUS imaging and the lipid-rich plaque area determined by histology. LRPB, which can be measured in patients with NIRS-IVUS imaging, corresponds to the amount of lipid-rich plaque in a coronary artery. LRPB should be evaluated in prospective clinical trials for its ability to

  19. Novel combined miniature optical coherence tomography ultrasound probe for in vivo intravascular imaging

    NASA Astrophysics Data System (ADS)

    Yin, Jiechen; Li, Xiang; Jing, Joe; Li, Jiawen; Mukai, David; Mahon, Sari; Edris, Ahmad; Hoang, Khiet; Shung, K. Kirk; Brenner, Matthew; Narula, Jagat; Zhou, Qifa; Chen, Zhongping

    2011-06-01

    We have developed a miniature integrated optical coherence tomography (OCT) ultrasound (US) probing system for intravascular imaging applications. In the OCT probe, the light coming out of a single mode fiber is focused by a gradient-index lens and then reflected by a right-angle prism from the side of the probe into the sample. It was combined with a 35 MHz PMN-PT side-viewing ultrasound transducer to obtain the ultrasound image as well. The OCT and ultrasound probes were integrated as a single probe to obtain OCT and ultrasound images simultaneously. The integrated probe has an outer diameter of 0.69 mm which, to our knowledge, is the smallest integrated OCT-US probe reported. Fast data acquisition and processing was implemented for real-time imaging. In vitro OCT and US images of human coronary artery with pathology, as well as in vivo images of normal rabbit abdominal aorta, were obtained using the integrated OCT-US probe to demonstrate its capability.

  20. Serial Optical Coherence Tomography and Intravascular Ultrasound Analysis of Gender Difference in Changes of Plaque Phenotype in Response to Lipid-Lowering Therapy.

    PubMed

    Minami, Yoshiyasu; Hou, Jingbo; Xing, Lei; Jia, Haibo; Hu, Sining; Vergallo, Rocco; Soeda, Tsunenari; Lee, Hang; Zhang, Shaosong; Yu, Bo; Jang, Ik-Kyung

    2016-06-15

    Although the clinical benefit of statins have been demonstrated in both genders, gender differences in the response to statin therapy on plaque morphologic changes have not been reported. A total of 66 nonculprit plaques from 46 patients who had serial image acquisition at baseline, 6 months, and 12 months by both optical coherence tomography and intravascular ultrasound (IVUS) were included. Patients were treated with atorvastatin 60 mg (AT60) or 20 mg (AT20). The baseline characteristics were similar between women (n = 16) and men (n = 30) except for age (59.3 ± 6.8 vs 52.5 ± 10.6 years, p = 0.027) and smoking status (12.5% vs 70.0%, p <0.001). The change in fibrous cap thickness (FCT) at 12 months was significant in both groups (108.8 ± 87.4 μm, p <0.001, 91.3 ± 70.1 μm, p <0.001, respectively) without significant difference between the groups (p = 0.437). The percent change in mean lipid arc at 6 months was significantly greater in women than that in men (-12.8 ± 18.8% vs -1.56 ± 21.8%, p = 0.040). In women, the percent change of FCT in the AT20 group was similar to that in the AT60 group (182.5 ± 199.5% vs 192.9 ± 149.7%, p = 0.886). However, in men, the percent change of FCT in the AT20 group was significantly smaller than that in the AT60 group (92.2 ± 90.5% vs 225.9 ± 104.3%, p <0.001). No significant change in percent atheroma volume by IVUS was seen at 12 months in both women and men. In conclusion, statin therapy was effective in both genders for plaque stabilization at 12-month follow-up. High-intensity statin therapy may be particularly important in men. PMID:27138187

  1. Intravascular photoacoustic imaging at 35 and 80 MHz

    PubMed Central

    Li, Xiang; Wei, Wei; Shung, K. Kirk

    2012-01-01

    Abstract. The catheter-based intravascular photoacoustic (IVPA) imaging for diagnosing atherosclerosis, which can provide optical absorption contrast of the arterial wall besides acoustic scattering contrast from the conventional intravascular ultrasound (IVUS) imaging, has been intensively researched recently. The resolution of IVPA is determined by the frequency bandwidth of an ultrasonic transducer. Higher resolution can be achieved by increasing the transducer’s working frequency and bandwidth. We introduce IVPA imaging at 35 and 80 MHz by using newly designed integrated IVUS/IVPA probes. This is the first time IVPA has been achieved as high as 80 MHz. Six-micrometer tungsten wires were imaged to evaluate the probes’ spatial resolutions and beam patterns. Healthy rabbit aorta was imaged in vitro. Imaging results show that IVPA has superior contrast over IVUS in identifying the arterial wall, and IVPA at 80 MHz demonstrates extraordinary resolution (35 μm) compared to 35 MHz. PMID:23224004

  2. Intraarterial Ultrasound in Pancreatic Cancer: Feasibility Study and Preliminary Results

    SciTech Connect

    Larena-Avellaneda, Axel; Timm, Stephan; Kickuth, Ralph; Kenn, Werner; Steger, Ulrich; Jurowich, Christian; Germer, Christoph-Thomas

    2010-08-15

    Despite technological advances in computed tomography (CT) and magnetic resonance imaging, the involvement of the celiac or mesenteric artery in pancreatic cancer remains uncertain in many cases. Infiltration of these vessels is important in making decisions about therapy choices but often can only be definitively determined through laparotomy. Local (intraarterial) ultrasound may increase diagnostic accuracy. Using the Volcano intravascular ultrasound (IVUS) system, we applied a transfemoral method to scan the celiac and mesenteric arteries directly intraarterial. This technique was used in five patients with suspected pancreatic cancer. Technical success was achieved in all cases. In one case, a short dissection of the mesenteric artery occurred but could be managed interventionally. In tumors that did not contact with the vessels, IVUS was unable to display the tissue pathology. Our main interest was the infiltration of the arteries. In one case, infiltration was certain in the CT scan but uncertain in two patients. In the latter two cases, IVUS correctly predicted infiltration in one and freedom from tumor in the other case. In our preliminary study, IVUS correctly predicted arterial infiltration in all cases. IVUS did not provide new information when the tumor was far away from the vessel. Compared with IVUS in the portal vein, the information about the artery is more detailed, and the vessel approach is easier. These results encouraged us to design a prospective study to evaluate the sensitivity and specificity of this method.

  3. Endovascular Repair of Complex Aortic Aneurysms: Intravascular Ultrasound Guidance with an Intracardiac Probe

    SciTech Connect

    Zanchetta, Mario Rigatelli, Gianluca; Pedon, Luigi; Zennaro, Marco; Ronsivalle, Salvatore; Maiolino, Pietro

    2003-09-15

    To assess the accuracy and efficacy of intravascular ultrasound guidance obtained by an intracardiac ultrasound probe during complex aortic endografting. Between November 1999 and July 2002, 19 patients (5 female, 14 male; mean age 73.5 {+-} 2.1 years) underwent endovascular repair of thoracic (n = 10), complex abdominal (n = 6) and concomitant thoraco-abdominal (n = 3) aortic aneurysm. The most suitable size and configuration of the stent-graft were chosen on the basis of preoperative computed tomographic angiography (CTA) or magnetic resonance angiography (MRA). Intraoperative intravascular ultrasound imaging was obtained using a 9 Fr, 9 MHz intracardiac echocardiography (ICE) probe, 110 cm in length, inserted through a 10 Fr precurved long sheath. The endografts were deployed as planned by CTA or MRA. Before stent-graft deployment, the ICE probe allowed us to view the posterior aortic arch and descending thoraco-abdominal aorta without position-related artifacts, and to identify both sites of stent-graft positioning. After stent-graft deployment, the ICE probe allowed us to detect the need for additional modular components to internally reline the aorta in 11 patients, and to discover 2 incomplete graft expansions subsequently treated with adjunctive balloon angioplasty. In 1 patient, the ICE probe supported the decision that the patient was ineligible for the endovascular exclusion procedure. The ICE probe provides accurate information on the anatomy of the posterior aortic arch and thoracic and abdominal aortic aneurysms and a rapid identification of attachment sites and stent-graft pathology, allowing refinement and improvement of the endovascular strategy.

  4. Long-Term Histopathologic and IVUS Evaluations of a Novel Coiled Sheet Stent in Porcine Carotid Arteries

    SciTech Connect

    Kaneda, Hideaki; Ikeno, Fumiaki Lyons, Jennifer; Rezaee, Mehrdad; Yeung, Alan C.; Fitzgerald, Peter J.

    2006-06-15

    Carotid angioplasty with stent placement has been proposed as an alternative method for revascularization of carotid artery stenosis. A novel stent with a laser-cut, rolled sheet of Nitinol (EndoTex Interventional Systems, Inc., Cupertino, CA) has been developed to customize treatment of stenotic lesions in carotid arteries utilizing a single stent, designed to adapt to multiple diameters and to tapered or nontapered configurations. The purpose of this study is to evaluate the conformability and vascular response to a novel stent in a chronic porcine carotid model using serial three-dimensional intravascular ultrasound (IVUS) analysis as well as histological examination. Ten Yucatan pigs underwent stent implantation in both normal carotid arteries with adjunctive balloon angioplasty. Three-dimensional IVUS analysis was performed before stent implantation, after adjunctive balloon angioplasty, and at follow-up [1 month (n = 6), 3 months (n = 6), or 6 months (n = 8)]. Histological examination (injury score, percent plaque obstruction, and qualitative analysis) was also performed. All stents were successfully deployed and well apposed in different sized vessels (lumen area range: 19-30 mm{sup 2}). Volumetric IVUS analysis showed no significant difference between the lumen areas before stent implantation and after adjunctive balloon angioplasty and no stent area change at each follow-up point compared to immediately postprocedure. Histological examination revealed minimal injury and neointimal hyperplasia at each follow-up point. In the chronic porcine carotid model, the novel stent system demonstrated good conformability, resulting in minimal vessel injury and neointimal formation.

  5. An automated approach for segmentation of intravascular ultrasound images based on parametric active contour models.

    PubMed

    Vard, Alireza; Jamshidi, Kamal; Movahhedinia, Naser

    2012-06-01

    This paper presents a fully automated approach to detect the intima and media-adventitia borders in intravascular ultrasound images based on parametric active contour models. To detect the intima border, we compute a new image feature applying a combination of short-term autocorrelations calculated for the contour pixels. These feature values are employed to define an energy function of the active contour called normalized cumulative short-term autocorrelation. Exploiting this energy function, the intima border is separated accurately from the blood region contaminated by high speckle noise. To extract media-adventitia boundary, we define a new form of energy function based on edge, texture and spring forces for the active contour. Utilizing this active contour, the media-adventitia border is identified correctly even in presence of branch openings and calcifications. Experimental results indicate accuracy of the proposed methods. In addition, statistical analysis demonstrates high conformity between manual tracing and the results obtained by the proposed approaches.

  6. The relationship among extent of lipid-rich plaque, lesion characteristics, and plaque progression/regression in patients with coronary artery disease: a serial near-infrared spectroscopy and intravascular ultrasound study

    PubMed Central

    Dohi, Tomotaka; Maehara, Akiko; Moreno, Pedro R.; Baber, Usman; Kovacic, Jason C.; Limaye, Atul M.; Ali, Ziad A.; Sweeny, Joseph M.; Mehran, Roxana; Dangas, George D.; Xu, Ke; Sharma, Samin K.; Mintz, Gary S.; Kini, Annapoorna S.

    2015-01-01

    Aims To evaluate the relationship between lipid content and plaque morphometry as well as the process of lesion progression and regression in patients with significant coronary artery disease. Methods and results The present study, using data from the YELLOW trial, was conducted in patients having significant coronary lesions (fractional flow reserve <0.8) who underwent serial intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) at baseline and after 7 weeks. For each coronary plaque (≥50% plaque burden that was ≥5 mm in length), we evaluated plaque characteristics and the extent of lipid-rich plaque [LRP, defined as the 4 mm long segment with the maximum lipid-core burden index (maxLCBI4 mm)] on NIRS. Among 66 patients (age 63.0 ± 10.1 years; 82% statin use at baseline), 94 plaques were identified. The extent of LRP at baseline was positively correlated with IVUS plaque burden (r = 0.317, P = 0.002). A large LRP (maxLCBI4 mm ≥500) was present only in plaques with a large plaque burden (≥70%). Multivariate analysis demonstrated that plaque burden was the best predictor of the extent of LRP (P < 0.001). In lesions with a large plaque burden and a large amount of LRP at baseline, a reduction in LRP was seen in all lesions in patients receiving intensive statin therapy (P = 0.004) without a significant change in plaque burden. Conclusions Coronary lesions containing a large amount of LRP also had a large plaque burden. Short-term regression of LRP (without a change in plaque burden) was observed mainly in plaques with a large plaque burden and a large amount of LRP at baseline. Clinical Trial Registration http://www.clinicaltrials.gov. Unique identifier: NCT01567826. PMID:25190072

  7. A preliminary engineering design of intravascular dual-frequency transducers for contrast-enhanced acoustic angiography and molecular imaging.

    PubMed

    Ma, Jianguo; Martin, K; Dayton, Paul A; Jiang, Xiaoning

    2014-05-01

    Current intravascular ultrasound (IVUS) probes are not optimized for contrast detection because of their design for high-frequency fundamental-mode imaging. However, data from transcutaneous contrast imaging suggests the possibility of utilizing contrast ultrasound for molecular imaging or vasa vasorum assessment to further elucidate atherosclerotic plaque deposition. This paper presents the design, fabrication, and characterization of a small-aperture (0.6 × 3 mm) IVUS probe optimized for high-frequency contrast imaging. The design utilizes a dual-frequency (6.5 MHz/30 MHz) transducer arrangement for exciting microbubbles at low frequencies (near their resonance) and detecting their broadband harmonics at high frequencies, minimizing detected tissue backscatter. The prototype probe is able to generate nonlinear microbubble response with more than 1.2 MPa of rarefractional pressure (mechanical index: 0.48) at 6.5 MHz, and is also able to detect microbubble response with a broadband receiving element (center frequency: 30 MHz, -6-dB fractional bandwidth: 58.6%). Nonlinear super-harmonics from microbubbles flowing through a 200-μm-diameter micro-tube were clearly detected with a signal-to-noise ratio higher than 12 dB. Preliminary phantom imaging at the fundamental frequency (30 MHz) and dual-frequency super-harmonic imaging results suggest the promise of small aperture, dual-frequency IVUS transducers for contrast-enhanced IVUS imaging. PMID:24801226

  8. A Preliminary Engineering Design of Intravascular Dual-Frequency Transducers for Contrast-Enhanced Acoustic Angiography and Molecular Imaging

    PubMed Central

    Ma, Jianguo; Martin, K. Heath; Dayton, Paul A.; Jiang, Xiaoning

    2014-01-01

    Current intravascular ultrasound (IVUS) probes are not optimized for contrast detection because of their design for high-frequency fundamental-mode imaging. However, data from transcutaneous contrast imaging suggests the possibility of utilizing contrast ultrasound for molecular imaging or vasa vasorum assessment to further elucidate atherosclerotic plaque deposition. This paper presents the design, fabrication, and characterization of a small-aperture (0.6 × 3 mm) IVUS probe optimized for high-frequency contrast imaging. The design utilizes a dual-frequency (6.5 MHz/30 MHz) transducer arrangement for exciting microbubbles at low frequencies (near their resonance) and detecting their broadband harmonics at high frequencies, minimizing detected tissue backscatter. The prototype probe is able to generate nonlinear microbubble response with more than 1.2 MPa of rarefractional pressure (mechanical index: 0.48) at 6.5 MHz, and is also able to detect microbubble response with a broadband receiving element (center frequency: 30 MHz, −6-dB fractional bandwidth: 58.6%). Nonlinear super-harmonics from microbubbles flowing through a 200-μm-diameter micro-tube were clearly detected with a signal-to-noise ratio higher than 12 dB. Preliminary phantom imaging at the fundamental frequency (30 MHz) and dual-frequency super-harmonic imaging results suggest the promise of small aperture, dual-frequency IVUS transducers for contrast-enhanced IVUS imaging. PMID:24801226

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

    PubMed Central

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

    2015-01-01

    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. PMID:25914443

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

    PubMed

    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 <0.001). 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.

  11. [Spontaneous coronary artery dissection treated by intravascular ultrasound-guided percutaneous coronary intervention: case report and review of the literature].

    PubMed

    Ciliberti, Giuseppe; Notaristefano, Francesco; Sclafani, Rocco; Notaristefano, Salvatore; Giombolini, Claudio; Fortunati, Federico; Ambrosio, Giuseppe; Cavallini, Claudio

    2015-06-01

    Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic coronary artery disease, which typically affects women with a low cardiovascular risk profile, and its prevalence as a cause of acute coronary syndrome and sudden death is probably under-recognized. The pathophysiology of SCAD consists essentially in the formation of an intramural hematoma, with or without intimal tear, which causes luminal compression and obstruction. The most used technique for the diagnosis of SCAD is coronary angiography. Intravascular imaging tools, such as intravascular ultrasound and optical coherence tomography, provide a more accurate characterization of the coronary wall, allowing diagnosis when angiography is unclear. We present the case of a young woman admitted with typical chest pain associated with electrocardiographic changes and elevated cardiac troponin I.

  12. User-agent cooperation in multiagent IVUS image segmentation.

    PubMed

    Bovenkamp, E G P; Dijkstra, J; Bosch, J G; Reiber, J H C

    2009-01-01

    Automated interpretation of complex images requires elaborate knowledge and model-based image analysis, but often needs interaction with an expert as well. This research describes expert interaction with a multiagent image interpretation system using only a restricted vocabulary of high-level user interactions. The aim is to minimize inter- and intra-observer variability by keeping the total number of interactions as low and simple as possible. The multiagent image interpretation system has elaborate high-level knowledge-based control over low-level image segmentation algorithms. Agents use contextual knowledge to keep the number of interactions low but, when in doubt, present the user with the most likely interpretation of the situation. The user, in turn, can correct, supplement, and/or confirm the results of image-processing agents. This is done at a very high level of abstraction such that no knowledge of the underlying segmentation methods, parameters or agent functioning is needed. High-level interaction thereby replaces more traditional contour correction methods like inserting points and/or (re)drawing contours. This makes it easier for the user to obtain good results, while inter- and intra-observer variability are kept minimal, since the image segmentation itself remains under control of image-processing agents. The system has been applied to intravascular ultrasound (IVUS) images. Experiments show that with an average of 2-3 high-level user interactions per correction, segmentation results substantially improve while the variation is greatly reduced. The achieved level of accuracy and repeatability is equivalent to that of manual drawing by an expert. PMID:19116192

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

    PubMed

    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 (<3 months) after an initial left ventricular (LV) lead implantation with significant fibrous tissue. The 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.

  14. Level of Pregnancy-associated Plasma Protein-A Correlates With Coronary Thin-cap Fibroatheroma Burden in Patients With Coronary Artery Disease: Novel Findings From 3-Vessel Virtual Histology Intravascular Ultrasound Assessment.

    PubMed

    Wu, Xiao-Fan; Yang, Min; Qu, Ai-Juan; Mintz, Gary S; Yang, Ya; Shang, Yun-Peng; Gao, Hai; Zhang, Yu-Chen; Ge, Chang-Jiang; Wang, Lu-Ya; Wang, Lin; Pu, Jun

    2016-01-01

    Pregnancy-associated plasma protein-A (PAPP-A) level is an independent predictor of acute cardiovascular event occurrence. To test the hypothesis that increased PAPP-A levels would be associated with a higher burden of coronary thin-cap fibroatheroma (TCFA) thereby underlying the heightened risk for cardiovascular events in patients with coronary artery disease; 154 patients (462 vessels and 975 plaques) with stable angina or non-ST-segment elevation acute coronary syndrome (NSTE-ACS) referred for percutaneous coronary intervention were assessed using 3-vessel virtual histology (VH)-intravascular ultrasound (IVUS). Thin-cap fibroatheroma virtual histology was defined as focal, necrotic core (NC)-rich (≥10% of cross-sectional area) plaques in contact with the lumen, and plaque burden ≥40%. Pregnancy-associated plasma protein-A levels were determined by sandwich enzyme-linked immunosorbent assay, and patients were divided into 3 groups based on PAPP-A level tertiles. Although the highest PAPP-A level tertile was not associated with 3-vessel plaque number, it was associated with 3-vessel VH-TCFA number and necrotic core volume. Patients with ≥3 VH-TCFAs had a higher PAPP-A level than patients with 1 to 3 VH-TCFAs or without any VH-TCFA (13.3 ± 11.8 versus 7.8 ± 4.7 versus 7.4 ± 4.7 mIU/L, P < 0.001, respectively). Moreover, PAPP-A level was an independent predictor of higher total number of VH-TCFAs (OR 1.18; 95% CI 1.07-1.29, P = 0.001). This VH-IVUS study demonstrated, for the first time to our knowledge, that higher PAPP-A levels are associated with higher 3-vessel TCFA burden in patients with coronary artery disease. Pregnancy-associated plasma protein-A, therefore, might be a useful serum biomarker to predict increased coronary TCFA burden and plaque instability. PMID:26817910

  15. Ex Vivo Porcine Arterial and Chorioallantoic Membrane Acoustic Angiography Using Dual-Frequency Intravascular Ultrasound Probes.

    PubMed

    Martin, K Heath; Lindsey, Brooks D; Ma, Jianguo; Nichols, Timothy C; Jiang, Xiaoning; Dayton, Paul A

    2016-09-01

    The presence of blood vessels within a developing atherosclerotic plaque has been found to be correlated with increased plaque vulnerability and ensuing cardiac events, however, detection of coronary intraplaque neovascularization poses a significant challenge in the clinic. We describe here a new in vivo intravascular ultrasound imaging method using a dual-frequency transducer to visualize contrast flow in microvessels with high specificity. This method uses a specialized transducer capable of exciting contrast agents at a low frequency (5.5 MHz) while detecting their nonlinear superhamonics at a much higher frequency (37 MHz). In vitro evaluation of the approach was performed in a microvascular phantom to produce 3-D renderings of simulated vessel patterns and to determine image quality metrics as a function of depth. Furthermore, we describe the ability of the system to detect microvessels both ex vivo using porcine arteries and in vivo using the chorioallantoic membrane of a developing chicken embryo with optical confirmation. Dual-frequency contrast-specific imaging was able to resolve vessels similar in size to those found in vulnerable atherosclerotic plaques at clinically relevant depths. The results of this study add to the support for further evaluation and translation of contrast-specific imaging in intravascular ultrasound for the detection of vulnerable plaques in atherosclerosis. PMID:27260246

  16. Intravascular ultrasonic-photoacoustic (IVUP) endoscope with 2.2-mm diameter catheter for medical imaging.

    PubMed

    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.

  17. Measurement of coronary flow using high-frequency intravascular ultrasound imaging and pulsed Doppler velocimetry: in vitro feasibility studies.

    PubMed

    Grayburn, P A; Willard, J E; Haagen, D R; Brickner, M E; Alvarez, L G; Eichhorn, E J

    1992-01-01

    The recent development of intravascular ultrasound imaging offers the potential to measure blood flow as the product of vessel cross-sectional area and mean velocity derived from pulsed Doppler velocimetry. To determine the feasibility of this approach for measuring coronary artery flow, we constructed a flow model of the coronary circulation that allowed flow to be varied by adjusting downstream resistance and aortic driving pressure. Assessment of intracoronary flow velocity was accomplished using a commercially available end-mounted pulsed Doppler catheter. Cross-sectional area of the coronary artery was measured using a 20 MHz mechanical imaging transducer mounted on a 4.8 F catheter. The product of mean velocity and cross-sectional area was compared with coronary flow measured by timed collection in a graduated cylinder by linear regression analysis. Excellent correlations were obtained between coronary flow calculated by the ultrasound method and measured coronary flow at both ostial (r = 0.99, standard error of the estimate [SEE] = 13.9 ml/min) and distal (r = 0.98, SEE = 23.0 ml/min) vessel locations under steady flow conditions. During pulsatile flow, calculated and measured coronary flow also correlated well for ostial (r = 0.98, SEE = 12.7 ml/min) and downstream (r = 0.99, SEE = 9.3 ml/min) locations. That the SEE was lower for pulsatile as compared with steady flow may be explained by the blunting of the flow profile across the vessel lumen by the acceleration phase of pulsatile flow. These data establish the feasibility of measuring coronary artery blood flow using intravascular ultrasound imaging and pulsed Doppler techniques. PMID:1531416

  18. Early Effects of Intensive Lipid-Lowering Treatment on Plaque Characteristics Assessed by Virtual Histology Intravascular Ultrasound

    PubMed Central

    Lee, Jung-Hee; Shin, Dong-Ho; Kim, Byeong-Keuk; Ko, Young-Guk; Choi, Donghoon; Jang, Yangsoo

    2016-01-01

    Purpose The effects of short-term intensive lipid-lowering treatment on coronary plaque composition have not yet been sufficiently evaluated. We investigated the influence of short-term intensive lipid-lowering treatment on quantitative and qualitative changes in plaque components of non-culprit lesions in patients with acute coronary syndrome. Materials and Methods This was a prospective, randomized, open-label, single-center trial. Seventy patients who underwent both baseline and three-month follow-up virtual histology intravascular ultrasound were randomly assigned to either an intensive lipid-lowering treatment group (ezetimibe/simvastatin 10/40 mg, n=34) or a control statin treatment group (pravastatin 20 mg, n=36). Using virtual histology intravascular ultrasound, plaque was characterized as fibrous, fibro-fatty, dense calcium, or necrotic core. Changes in plaque components during the three-month lipid-lowering treatment were compared between the two groups. Results Compared with the control statin treatment group, there was a significant reduction in low-density lipoprotein cholesterol in the intensive lipid-lowering treatment group (-20.4±17.1 mg/dL vs. -36.8±17.4 mg/dL, respectively; p<0.001). There were no statistically significant differences in baseline, three-month follow-up, or serial changes of gray-scale intravascular ultrasound parameters between the two groups. The absolute volume of fibro-fatty plaque was significantly reduced in the intensive lipid-lowering treatment group compared with the control group (-1.5±3.4 mm3 vs. 0.8±4.7 mm3, respectively; p=0.024). A linear correlation was found between changes in low-density lipoprotein cholesterol levels and changes in the absolute volumes of fibro-fatty plaque (p<0.001, R2=0.209). Conclusion Modification of coronary plaque may be attainable after only three months of intensive lipid-lowering treatment. PMID:27401638

  19. Lipid detection by intravascular photoacoustic imaging with flexible catheter at 20 fps (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    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.

  20. Design factors of intravascular dual frequency transducers for super-harmonic contrast imaging and acoustic angiography

    NASA Astrophysics Data System (ADS)

    Ma, Jianguo; Martin, K. Heath; Li, Yang; Dayton, Paul A.; Shung, K. Kirk; Zhou, Qifa; Jiang, Xiaoning

    2015-05-01

    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 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 the design of intravascular acoustic angiography transducers.

  1. Intravascular photoacoustic imaging of atherosclerotic plaques: ex-vivo study using a rabbit model of atherosclerosis

    NASA Astrophysics Data System (ADS)

    Sethuraman, S.; Mallidi, S.; Aglyamov, S. R.; Amirian, J. H.; Litovsky, S.; Smalling, R. W.; Emelianov, S. Y.

    2007-02-01

    Diagnosis and treatment of atherosclerosis necessitates the detection and differentiation of rupture prone plaques. In principle, intravascular photoacoustic (IVPA) imaging has the ability to simultaneously visualize the structure and composition of atherosclerotic plaques by utilizing the difference in optical absorption. Extensive studies are required to validate the utility of IVPA imaging in detecting vulnerable plaques and address issues associated with the clinical implementation of the technique. In this work, we performed ex vivo imaging studies using a rabbit model of atherosclerosis. The intravascular photoacoustic (IVPA) and ultrasound (IVUS) images of the normal aorta and aorta with plaque were obtained and compared with histological slices of the tissue. The results indicate that IVPA imaging is capable of detecting plaques and showed potential in determining the composition. Furthermore, we initially addressed several aspects of clinical implementation of the IVPA imaging. Specifically, the configuration of combined IVPA and IVUS catheter was investigated and the effect of the optical absorption of the luminal blood on the IVPA image quality was evaluated. Overall, this study suggests that IVPA imaging can become a unique and important clinical tool.

  2. Design factors of intravascular dual frequency transducers for super-harmonic contrast imaging and acoustic angiography

    PubMed Central

    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

  3. Design factors of intravascular dual frequency transducers for super-harmonic contrast imaging and acoustic angiography.

    PubMed

    Ma, Jianguo; Martin, K Heath; Li, Yang; Dayton, Paul A; Shung, K Kirk; Zhou, Qifa; Jiang, Xiaoning

    2015-05-01

    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 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 the design of intravascular acoustic angiography transducers. PMID:25856384

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

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

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

    PubMed

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

    2010-10-01

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

  6. 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.

    PubMed

    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.

  7. Multimodality Intravascular Imaging Assessment of Plaque Erosion versus Plaque Rupture in Patients with Acute Coronary Syndrome

    PubMed Central

    Kwon, Jee Eun; Mintz, Gary S.; Hong, Young Joon; Lee, Sung Yun; Kim, Ki Seok; Hahn, Joo-Yong; Kumar, Kaup Sharath; Won, Hoyoun; Hyeon, Seong Hyeop; Shin, Seung Yong; Lee, Kwang Je; Kim, Tae Ho; Kim, Chee Jeong; Kim, Sang Wook

    2016-01-01

    Background and Objectives We assessed plaque erosion of culprit lesions in patients with acute coronary syndrome in real world practice. Subjects and Methods Culprit lesion plaque rupture or plaque erosion was diagnosed with optical coherence tomography (OCT). Intravascular ultrasound (IVUS) was used to determine arterial remodeling. Positive remodeling was defined as a remodeling index (lesion/reference EEM [external elastic membrane area) >1.05. Results A total of 90 patients who had plaque rupture showing fibrous-cap discontinuity and ruptured cavity were enrolled. 36 patients showed definite OCT-plaque erosion, while 7 patients had probable OCT-plaque erosion. Overall, 26% (11/43) of definite/probable plaque erosion had non-ST elevation myocardial infarction (NSTEMI) while 35% (15/43) had ST elevation myocardial infarction (STEMI). Conversely, 14.5% (13/90) of plaque rupture had NSTEMI while 71% (64/90) had STEMI (p<0.0001). Among plaque erosion, white thrombus was seen in 55.8% (24/43) of patients and red thrombus in 27.9% (12/43) of patients. Compared to plaque erosion, plaque rupture more often showed positive remodeling (p=0.003) with a larger necrotic core area examined by virtual histology (VH)-IVUS, while negative remodeling was prominent in plaque erosion. Overall, 65% 28/43 of plaque erosions were located in the proximal 30 mm of a culprit vessel-similar to plaque ruptures (72%, 65/90, p=0.29). Conclusion Although most of plaque erosions show nearly normal coronary angiogram, modest plaque burden with negative remodeling and an uncommon fibroatheroma might be the nature of plaque erosion. Multimodality intravascular imaging with OCT and VH-IVUS showed fundamentally different pathoanatomic substrates underlying plaque rupture and erosion. PMID:27482258

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

    PubMed

    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.

  9. Intravascular Imaging

    NASA Astrophysics Data System (ADS)

    de Jong, Nico; Bom, Nicolaas; Schaar, Johannes; Goertz, David; Frijlink, Martijn; Steen, Anton Fw Van Der

    IVUS is used for diagnostics, therapy guidance and scientific purposes. It is the only clinical available technique that can assess plaque burden and free lumen diameter at high accuracy. Contrast angiography, which was the golden standard before IVUS, can only give a shadow projection of the lumen. Especially with the advent of 3D IVUS using pull backs it became an important tool for monitoring treatment and follow up of interventions like balloon angioplasty and placing of stents (wire prostheses that are used to prevent the arterial wall from recoiling). 3D IVUS in combination with biplane angiography allows assessment of true 3D reconstructions of arteries, pre and post treatment. Using computational fluid dynamics the velocity profile and thus the shear stress at the vascular wall can be calculated. This can be related to biological markers, which gives insight in formation of atherosclerosis, restenosis and remodelling.

  10. Age-related effects of smoking on coronary artery disease assessed by gray scale and virtual histology intravascular ultrasound.

    PubMed

    Kang, Soo-Jin; Mintz, Gary S; Weisz, Giora; Mehran, Roxana; Rabbani, LeRoy E; Verheye, Stefan; Serruys, Patrick W; Xu, Ke; Stone, Gregg W; Maehara, Akiko

    2015-04-15

    Although smoking is a risk factor for coronary atherosclerosis, the age-related impact on lesion morphology has not been studied. The aim of this study was to assess the age-related impact of smoking on the extent of atherosclerosis and arterial remodeling. In Providing Regional Observations to Study Predictors of Events in the Coronary Tree, 687 patients with acute coronary syndrome underwent 3-vessel gray scale and virtual histology intravascular ultrasound imaging of 3,185 nonculprit lesions. In 207 patients ≤65 years, current (smoking within 1 month) and former (no smoking for >1 month) smokers showed significantly smaller normalized volumes of external elastic membrane (EEM), lumen, and P + M (plaque + media) compared with nonsmokers. At the minimal lumen area site, current and former smokers had significantly smaller EEM, lumen, and P + M areas than nonsmokers. Conversely, in 480 patients >65 years, current smokers had greater normalized P + M volumes than nonsmokers with no difference in normalized EEM or lumen volumes. Finally, in patients >65 years (but not in patients ≤65 years), current smokers showed more plaque ruptures (4.7% vs 1.8%, p = 0.05) and echolucent plaques (8.3% vs 3.9%, p = 0.05) compared with nonsmokers. On multivariable analysis, a history of smoking (combining current and former smoking) predicted smaller normalized EEM volumes compared with nonsmokers ≤65 years. In conclusion, in patients ≤65 years, but not in patients >65 years, smoking had a vascular constrictive effect that contributed to severe luminal stenosis. Conversely, smokers >65 years had more plaque with greater plaque instability. PMID:25726380

  11. Age-related effects of smoking on coronary artery disease assessed by gray scale and virtual histology intravascular ultrasound.

    PubMed

    Kang, Soo-Jin; Mintz, Gary S; Weisz, Giora; Mehran, Roxana; Rabbani, LeRoy E; Verheye, Stefan; Serruys, Patrick W; Xu, Ke; Stone, Gregg W; Maehara, Akiko

    2015-04-15

    Although smoking is a risk factor for coronary atherosclerosis, the age-related impact on lesion morphology has not been studied. The aim of this study was to assess the age-related impact of smoking on the extent of atherosclerosis and arterial remodeling. In Providing Regional Observations to Study Predictors of Events in the Coronary Tree, 687 patients with acute coronary syndrome underwent 3-vessel gray scale and virtual histology intravascular ultrasound imaging of 3,185 nonculprit lesions. In 207 patients ≤65 years, current (smoking within 1 month) and former (no smoking for >1 month) smokers showed significantly smaller normalized volumes of external elastic membrane (EEM), lumen, and P + M (plaque + media) compared with nonsmokers. At the minimal lumen area site, current and former smokers had significantly smaller EEM, lumen, and P + M areas than nonsmokers. Conversely, in 480 patients >65 years, current smokers had greater normalized P + M volumes than nonsmokers with no difference in normalized EEM or lumen volumes. Finally, in patients >65 years (but not in patients ≤65 years), current smokers showed more plaque ruptures (4.7% vs 1.8%, p = 0.05) and echolucent plaques (8.3% vs 3.9%, p = 0.05) compared with nonsmokers. On multivariable analysis, a history of smoking (combining current and former smoking) predicted smaller normalized EEM volumes compared with nonsmokers ≤65 years. In conclusion, in patients ≤65 years, but not in patients >65 years, smoking had a vascular constrictive effect that contributed to severe luminal stenosis. Conversely, smokers >65 years had more plaque with greater plaque instability.

  12. New fabrication techniques for ring-array transducers for real-time 3D intravascular ultrasound.

    PubMed

    Light, Edward D; Lieu, Victor; Smith, Stephen W

    2009-10-01

    We have previously described miniature 2D array transducers integrated into a Cook Medical, Inc. vena cava filter deployment device. While functional, the fabrication technique was very labor intensive and did not lend itself well to efficient fabrication of large numbers of devices. We developed two new fabrication methods that we believe can be used to efficiently manufacture these types of devices in greater than prototype numbers. One transducer consisted of 55 elements operating near 5 MHz. The interelement spacing is 0.20 mm. It was constructed on a flat piece of copper-clad polyimide and then wrapped around an 11 French catheter of a Cook Medical, Inc. inferior vena cava (IVC) filter deployment device. We used a braided wiring technology from Tyco Electronics Corp. to connect the elements to our real-time 3D ultrasound scanner. Typical measured transducer element bandwidth was 20% centered at 4.7 MHz and the 50 Omega round trip insertion loss was --82 dB. The mean of the nearest neighbor cross talk was -37.0 dB. The second method consisted of a 46-cm long single layer flex circuit from MicroConnex that terminates in an interconnect that plugs directly into our system cable. This transducer had 70 elements at 0.157 mm interelement spacing operating at 4.8 MHz. Typical measured transducer element bandwidth was 29% and the 50 Omega round trip insertion loss was -83 dB. The mean of the nearest neighbor cross talk was -33.0 dB. PMID:20458877

  13. Left Main Ostial Compression in a Patient with Pulmonary Hypertension: Dynamic Findings by IVUS

    PubMed Central

    Seabra, Luciana F.; Ribeiro, Henrique B.; de Barros e Silva, Pedro Gabriel Melo; Rodrigues, Marcelo J.; Spadaro, André G.; Conejo, Fábio; Godinho, Roger R.; Faig, Sandro M. M.; de Macedo, Thiago Andrade; de P. S. Baptista, Luciana; de Resende, Marcos Valerio C.; Furlan, Valter; Ribeiro, Expedito E.

    2015-01-01

    Patient: Female, 39 Final Diagnosis: Idiopathic pulmonary arterial hypertension Symptoms: Chest pain Medication: — Clinical Procedure: Percutaneous coronary intervention Specialty: Cardiology and Pulmonology Objective: Rare co-existance of disease or pathology Background: Pulmonary artery dilatation is a common feature among patients with severe pulmonary hypertension. Left main coronary artery extrinsic compression by an enlarged pulmonary artery is a rare complication and a potential cause for chest pain and sudden cardiac death in patients with pulmonary hypertension. This situation is very rare and few reports have described it. Currently, the appropriate management of these patients remains unknown. Case Report: In the present report we describe the case of a 39-year-old woman who presented with a 2-year history of cardiac symptoms related to exercise. The patient underwent a 64-slice multidetector computed tomography (MDCT) coronary angiography, which showed left main coronary artery (LMCA) compression by a markedly enlarged pulmonary artery trunk (44 mm), without intraluminal stenosis or coronary artery calcium, as determined by the Agatston score. This compression was considered to be the cause of the cardiac symptoms. To confirm and plan the treatment, the patient underwent cardiac catheterization that confirmed the diagnosis of pulmonary hypertension and LMCA critical obstruction. Taking into account the paucity of information regarding the best management in these cases, the treatment decision was shared among a “heart team” that chose percutaneous coronary intervention with stent placement. An intra-vascular ultrasound was performed during the procedure, which showed a dynamic compression of the left main coronary artery. The intervention was successfully executed without any adverse events. Conclusions: This case illustrates dynamic compression of the LMCA by IVUS, visually demonstrating the mechanism of the intermittent symptoms of myocardial

  14. Surgical removal of an intravascular ultrasonography catheter captured in a stent after percutaneous coronary intervention.

    PubMed

    Minami, Hiroya; Asada, Tatsuro; Gan, Kunio; Yamada, Akitoshi; Sato, Masanobu

    2011-03-01

    A-79-year-old woman underwent percutaneous coronary intervention (PCI) to the right coronary artery (RCA) for effort angina, followed by intravascular ultrasonography (IVUS) to ascertain stent expansion. The IVUS catheter became entangled in the stent and could not be withdrawn from the outside. The patient was transferred to our hospital for its surgical removal. For the emergent surgery, we opened the stent region in the RCA and directly removed the IVUS catheter with the twisted stent. Additional coronary artery bypass grafting (CABG) involving three vessels was performed. She was discharged 42 days after surgery. PMID:21448795

  15. Single-chip CMUT-on-CMOS front-end system for real-time volumetric IVUS and ICE imaging.

    PubMed

    Gurun, Gokce; Tekes, Coskun; Zahorian, Jaime; Xu, Toby; Satir, Sarp; Karaman, Mustafa; Hasler, Jennifer; Degertekin, F Levent

    2014-02-01

    Intravascular ultrasound (IVUS) and intracardiac echography (ICE) catheters with real-time volumetric ultrasound imaging capability can provide unique benefits to many interventional procedures used in the diagnosis and treatment of coronary and structural heart diseases. Integration of capacitive micromachined ultrasonic transducer (CMUT) arrays with front-end electronics in single-chip configuration allows for implementation of such catheter probes with reduced interconnect complexity, miniaturization, and high mechanical flexibility. We implemented a single-chip forward-looking (FL) ultrasound imaging system by fabricating a 1.4-mm-diameter dual-ring CMUT array using CMUT-on-CMOS technology on a front-end IC implemented in 0.35-μm CMOS process. The dual-ring array has 56 transmit elements and 48 receive elements on two separate concentric annular rings. The IC incorporates a 25-V pulser for each transmitter and a low-noise capacitive transimpedance amplifier (TIA) for each receiver, along with digital control and smart power management. The final shape of the silicon chip is a 1.5-mm-diameter donut with a 430-μm center hole for a guide wire. The overall front-end system requires only 13 external connections and provides 4 parallel RF outputs while consuming an average power of 20 mW. We measured RF A-scans from the integrated single- chip array which show full functionality at 20.1 MHz with 43% fractional bandwidth. We also tested and demonstrated the image quality of the system on a wire phantom and an ex vivo chicken heart sample. The measured axial and lateral point resolutions are 92 μm and 251 μm, respectively. We successfully acquired volumetric imaging data from the ex vivo chicken heart at 60 frames per second without any signal averaging. These demonstrative results indicate that single-chip CMUT-on-CMOS systems have the potential to produce realtime volumetric images with image quality and speed suitable for catheter-based clinical applications.

  16. Single-Chip CMUT-on-CMOS Front-End System for Real-Time Volumetric IVUS and ICE Imaging

    PubMed Central

    Gurun, Gokce; Tekes, Coskun; Zahorian, Jaime; Xu, Toby; Satir, Sarp; Karaman, Mustafa; Hasler, Jennifer; Degertekin, F. Levent

    2014-01-01

    Intravascular ultrasound (IVUS) and intracardiac echography (ICE) catheters with real-time volumetric ultrasound imaging capability can provide unique benefits to many interventional procedures used in the diagnosis and treatment of coronary and structural heart diseases. Integration of CMUT arrays with front-end electronics in single-chip configuration allows for implementation of such catheter probes with reduced interconnect complexity, miniaturization, and high mechanical flexibility. We implemented a single-chip forward-looking (FL) ultrasound imaging system by fabricating a 1.4-mm-diameter dual-ring CMUT array using CMUT-on-CMOS technology on a front-end IC implemented in 0.35-µm CMOS process. The dual-ring array has 56 transmit elements and 48 receive elements on two separate concentric annular rings. The IC incorporates a 25-V pulser for each transmitter and a low-noise capacitive transimpedance amplifier (TIA) for each receiver, along with digital control and smart power management. The final shape of the silicon chip is a 1.5-mm-diameter donut with a 430-µm center hole for a guide wire. The overall front-end system requires only 13 external connections and provides 4 parallel RF outputs while consuming an average power of 20 mW. We measured RF A-scans from the integrated single-chip array which show full functionality at 20.1 MHz with 43% fractional bandwidth. We also tested and demonstrated the image quality of the system on a wire phantom and an ex-vivo chicken heart sample. The measured axial and lateral point resolutions are 92 µm and 251 µm, respectively. We successfully acquired volumetric imaging data from the ex-vivo chicken heart with 60 frames per second without any signal averaging. These demonstrative results indicate that single-chip CMUT-on-CMOS systems have the potential to produce real-time volumetric images with image quality and speed suitable for catheter based clinical applications. PMID:24474131

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

    PubMed

    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.

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

    PubMed

    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. PMID:26667446

  19. Morphological and Stress Vulnerability Indices for Human Coronary Plaques and Their Correlations with Cap Thickness and Lipid Percent: An IVUS-Based Fluid-Structure Interaction Multi-patient Study

    PubMed Central

    Wang, Liang; Zheng, Jie; Maehara, Akiko; Yang, Chun; Billiar, Kristen L.; Wu, Zheyang; Bach, Richard; Muccigrosso, David; Mintz, Gary S.; Tang, Dalin

    2015-01-01

    Plaque vulnerability, defined as the likelihood that a plaque would rupture, is difficult to quantify due to lack of in vivo plaque rupture data. Morphological and stress-based plaque vulnerability indices were introduced as alternatives to obtain quantitative vulnerability assessment. Correlations between these indices and key plaque features were investigated. In vivo intravascular ultrasound (IVUS) data were acquired from 14 patients and IVUS-based 3D fluid-structure interaction (FSI) coronary plaque models with cyclic bending were constructed to obtain plaque wall stress/strain and flow shear stress for analysis. For the 617 slices from the 14 patients, lipid percentage, min cap thickness, critical plaque wall stress (CPWS), strain (CPWSn) and flow shear stress (CFSS) were recorded, and cap index, lipid index and morphological index were assigned to each slice using methods consistent with American Heart Association (AHA) plaque classification schemes. A stress index was introduced based on CPWS. Linear Mixed-Effects (LME) models were used to analyze the correlations between the mechanical and morphological indices and key morphological factors associated with plaque rupture. Our results indicated that for all 617 slices, CPWS correlated with min cap thickness, cap index, morphological index with r = -0.6414, 0.7852, and 0.7411 respectively (p<0.0001). The correlation between CPWS and lipid percentage, lipid index were weaker (r = 0.2445, r = 0.2338, p<0.0001). Stress index correlated with cap index, lipid index, morphological index positively with r = 0.8185, 0.3067, and 0.7715, respectively, all with p<0.0001. For all 617 slices, the stress index has 66.77% agreement with morphological index. Morphological and stress indices may serve as quantitative plaque vulnerability assessment supported by their strong correlations with morphological features associated with plaque rupture. Differences between the two indices may lead to better plaque assessment schemes

  20. Dual-Mode IVUS Catheter for Intracranial Image-Guided Hyperthermia: Feasibility Study

    PubMed Central

    Herickhoff, Carl D.; Grant, Gerald A.; Britz, Gavin W.; Smith, Stephen W.

    2010-01-01

    In this study, we investigated the feasibility of modifying 3-Fr IVUS catheters in several designs to potentially achieve minimally-invasive, endovascular access for image-guided ultrasound hyperthermia treatment of tumors in the brain. Using a plane wave approximation, target frequencies of 8.7 and 3.5 MHz were considered optimal for heating at depths (tumor sizes) of 1 and 2.5 cm, respectively. First, a 3.5-Fr IVUS catheter with a 0.7-mm diameter transducer (30 MHz nominal frequency) was driven at 8.6 MHz. Second, for a low-frequency design, a 220-μm-thick, 0.35 × 0.35-mm PZT-4 transducer—driven at width-mode resonance of 3.85 MHz—replaced a 40-MHz element in a 3.5-Fr coronary imaging catheter. Third, a 5 × 0.5-mm PZT-4 transducer was evaluated as the largest aperture geometry possible for a flexible 3-Fr IVUS catheter. Beam plots and on-axis heating profiles were simulated for each aperture, and test transducers were fabricated. The electrical impedance, impulse response, frequency response, maximum intensity, and mechanical index were measured to assess performance. For the 5 × 0.5-mm transducer, this testing also included mechanically scanning and reconstructing an image of a 2.5-cm-diameter cyst phantom as a preliminary measure of imaging potential. PMID:21041144

  1. Catheter ultrasound for cross-sectional imaging and drug delivery to vessel wall

    NASA Astrophysics Data System (ADS)

    Hossack, John A.

    2015-05-01

    Current methods for delivery of an anti-restenosis drug to an arterial vessel wall post-percutaneous transluminal angioplasty and stent placement are limited in terms of drug choice, dosing level, and ability to assure drug coverage between the struts of a drug eluting stent. Intravascular ultrasound (IVUS) provides real-time, radiation-free, imaging and assessment of atherosclerotic disease in terms of anatomical, functional and molecular information. In this presentation, the design of a dual imaging / therapy IVUS catheter is described and results documenting gene and drug delivery reported. Microbubbles and drug / gene (shell associated or co-injected) are dispensed from the catheter tip. Using this approach, it becomes possible to address the need for complete vessel wall coverage and achieve delivery in regions poorly addressed using conventional stent-based approaches. A range of in vitro, ex vivo and in vivo results are presented. Our most recent results involve a demonstration in a pig model of coronary balloon angioplasty that produced a 33% reduction in neointima formation versus a drug plus microbubble, but no ultrasound, control.

  2. Impact of arterial remodelling and plaque rupture on target and non‐target lesion revascularisation after stent implantation in patients with acute coronary syndrome: an intravascular ultrasound study

    PubMed Central

    Okura, Hiroyuki; Taguchi, Haruyuki; Kubo, Tomoichiro; Toda, Iku; Yoshiyama, Minoru; Yoshikawa, Junichi; Yoshida, Kiyoshi

    2007-01-01

    Objectives To investigate the impact of arterial remodelling on long‐term clinical outcome after stent implantation in patients with acute coronary syndrome (ACS). Methods 134 patients with ACS were enrolled. External elastic membrane (EEM) cross‐sectional area (CSA) and lumen CSA were measured. Plaque and media CSA was calculated as EEM minus lumen CSA. Final minimal stent area (MSA) was also measured after stenting. Positive remodelling (PR) was defined as the ratio of the EEM CSA at the target lesion to that at the proximal reference of >1.05, and intermediate or negative remodelling (IR/NR) was defined as that of ⩽1.05. Results Although final MSA was similar, target lesion revascularisation (TLR) rates at 2 years were significantly higher in patients with PR (33.7%) than in those with IR/NR (13.7%; p = 0.01). In addition, non‐TLR rates were also significantly higher in patients with PR (42.2%) than in those with IR/NR (23.5%; p = 0.03). Cardiac event‐free survival (for events such as death, myocardial infarction, TLR and non‐TLR) was significantly lower in patients with PR than in those with IR/NR (log rank, p = 0.001). By multivariate logistic regression analysis, PR (χ2 6.57, OR 2.70; 95% CI, 1.27 to 5.78; p = 0.01) and plaque rupture (χ2 4.17, OR 2.38; 95% CI, 1.04 to 5.45; p = 0.04) were independent predictors of cardiac events. Conclusion In patients with ACS, PR and intravascular ultrasound findings that may correspond with plaque rupture predict cardiac events including both TLR and non‐TLR at 2 years. PMID:17395673

  3. Interstudy reproducibility of the second generation, Fourier domain optical coherence tomography in patients with coronary artery disease and comparison with intravascular ultrasound: a study applying automated contour detection.

    PubMed

    Jamil, Z; Tearney, G; Bruining, N; Sihan, K; van Soest, G; Ligthart, J; van Domburg, R; Bouma, B; Regar, E

    2013-01-01

    Recently, Fourier domain OCT (FD-OCT) has been introduced for clinical use. This approach allows in vivo, high resolution (15 micron) imaging with very fast data acquisition, however, it requires brief flushing of the lumen during imaging. The reproducibility of such fast data acquisition under intracoronary flush application is poorly understood. To assess the inter-study variability of FD-OCT and to compare lumen morphometry to the established invasive imaging method, IVUS. 18 consecutive patients with coronary artery disease scheduled for PCI were included. In each target vessel a FD-OCT pullback (MGH system, light source 1,310 nm, 105 fps, pullback speed 20 mm/s) was acquired during brief (3 s) injection of X-ray contrast (flow 3 ml/s) through the guiding catheter. A second pullback was repeated under the same conditions after re-introduction of the FD OCT catheter into the coronary artery. IVUS and OCT imaging was performed in random order. FD-OCT and IVUS pullback data were analyzed using a recently developed software employing semi automated lumen contour and stent strut detection algorithms. Corresponding ROI were matched based on anatomical landmarks such as side branches and/or stent edges. Inter-study variability is presented as the absolute difference between the two pullbacks. FD-OCT showed remarkably good reproducibility. Inter-study variability in native vessels (cohort A) was very low for mean and minimal luminal area (0.10 ± 0.38, 0.19 ± 0.57 mm(2), respectively). Likewise inter-study variability was very low in stented coronary segments (cohort B) for mean lumen, mean stent, minimal luminal and minimal stent area (0.06 ± 0.08, 0.07 ± 0.10, 0.04 ± 0.09, 0.04 ± 0.10 mm(2), respectively). Comparison to IVUS morphometry revealed no significant differences. The differences between both imaging methods, OCT and IVUS, were very low for mean lumen, mean stent, minimal luminal and minimal stent area (0.10 ± 0.45, 0.10 ± 0

  4. Correlation between high density lipoprotein-cholesterol and remodeling index in patients with coronary artery disease: IDEAS (IVUS diagnostic evaluation of atherosclerosis in Singapore)-HDL study.

    PubMed

    Lee, Chi-Hang; Tai, Bee-Choo; Lim, Gek-Hsiang; Chan, Mark Y; Low, Adrian F; Tan, Kathryn C; Chia, Boon-Lock; Tan, Huay-Cheem

    2012-01-01

    Serum level of high density lipoprotein (HDL)-cholesterol is associated with risk of coronary artery disease. We correlated the serum level of cholesterol with coronary artery remodeling index of patients with coronary artery disease. A total of 120 patients with de novo lesions located in native coronary artery were studied. Remodeling index was based on intravascular ultrasound (IVUS) interrogation of the lesions using the static approach, and was defined as external elastic membrane (EEM) area at lesion/average EEM area at proximal and distal reference segments. The average remodeling index was 0.9 (SD: 0.2). The remodeling index was not associated with any of the demographic and coronary risk factors. Stable angina was associated with a low remodeling index. Remodeling index correlated with white blood cell count and HDL-cholesterol, but not with total cholesterol, LDL-cholesterol and triglyceride. In the multiple linear regression analysis, HDL-cholesterol and procedure indication were the only 2 significant predictors of remodeling index. An increase of 1 mg/dL of HDL-cholesterol resulted in a decrease of 0.003 (95% CI: 0.0001, 0.007; P = 0.046) in remodeling index, after adjusting for procedural indications. When stratified according to diabetic status, the negative correlation persisted in non-diabetic (P = 0.023), but not in diabetic, patients (P = 0.707). We found a negative correlation between HDL-cholesterol level and remodeling index. Diabetic status may have an influence on the observed relationship. PMID:21197580

  5. Tools for experimental characterization of the non-uniform rotational distortion in intravascular OCT probes

    NASA Astrophysics Data System (ADS)

    Dufour, Marc L.; Bisaillon, Charles-Etienne; Lamouche, Guy; Vergnole, Sebastien; Hewko, Mark; D'Amours, Frédéric; Padioleau, Christian; Sowa, Michael

    2011-03-01

    The Industrial Material Institute (IMI) together with the Institute for Biodiagnostic (IBD) has developed its own optical catheters for cardiovascular imaging applications. Those catheters have been used experimentally in the in vitro coronary artery model of the Langendorff beating heart and in a percutaneous coronary intervention procedure in a porcine model. For some catheter designs, non-uniform rotational distortion (NURD) can be observed as expected from past experience with intra-vascular ultrasound (IVUS) catheters. A two-dimensional (2D) coronary artery test bench that simulates the path into the coronary arteries has been developed. The presence or absence of NURD can be assessed with the test bench using a custom-built cardiovascular Optical Coherence Tomography (OCT) imaging system. A square geometry instead of the circular shape of an artery is used to simulate the coronary arteries. Thereby, it is easier to visualize NURD when it is present. The accumulated torsion induced by the friction on the catheter is measured along the artery path. NURD is induced by the varying friction force that is balanced by the accumulated torsion force. The pullback force is measured and correlated with NURD observed in the 2D test bench. Finally, a model is presented to help understanding the mechanical constraint that leads to the friction force variations.

  6. Optical Micromachined Ultrasound Transducers (OMUT)-- A New Approach for High Frequency Ultrasound Imaging

    NASA Astrophysics Data System (ADS)

    Tadayon, Mohammad Amin

    Piezoelectric technology is the backbone of most medical ultrasound imaging arrays, however, in scaling the technology to sizes required for high frequency operation (> 20 MHz), it encounters substantial difficulties in fabrication and signal transduction efficiency. These limitations particularly affect the design of intravascular ultrasound (IVUS) imaging probes whose operating frequency can approach 60 MHz. Optical technology has been proposed and investigated for several decades as an alternative approach for high frequency ultrasound transducers. However, to apply this promising technology in guiding clinical operations such as in interventional cardiology, brain surgery, and laparoscopic surgery further raise in the sensitivity is required. Here, in order to achieve the required sensitivity for an intravascular ultrasound imaging probe, we introduce design changes making use of alternative receiver mechanisms. First, we present an air cavity detector that makes use of a polymer membrane for increased mechanical deflection. We have also significantly raised the thin film detector sensitivity by improving its optical characteristics. This can be achieved by inducing a refractive index feature inside the Fabry-Perot resonator that simply creates a waveguide between the two mirrors. This approach eliminates the loss in energy due to diffraction in the cavity, and therefore the Q-factor is only limited by mirror loss and absorption. To demonstrate this optical improvements, a waveguide Fabry-Perot resonator has been fabricated consisting of two dielectric Bragg reflectors with a layer of photosensitive polymer between them. The measured finesse of the fabricated resonator was 692, and the Q-factor was 55000. The fabrication process of this device has been modified to fabricate an ultrasonically testable waveguide Fabry-Perot resonator. By applying this method, we have achieved a noise equivalent pressure of 178 Pa over a bandwidth of 28 MHz or 0.03 Pa/Hz1/2 which

  7. Systematic study of the effects of lowering low-density lipoprotein-cholesterol on regression of coronary atherosclerotic plaques using intravascular ultrasound

    PubMed Central

    2014-01-01

    Background Conflicting results currently exist on the effects of LDL-C levels and statins therapy on coronary atherosclerotic plaque, and the target level of LDL-C resulting in the regression of the coronary atherosclerotic plaques has not been settled. Methods PubMed, EMBASE, and Cochrane databases were searched from Jan. 2000 to Jan. 2014 for randomized controlled or blinded end-points trials assessing the effects of LDL-C lowering therapy on regression of coronary atherosclerotic plaque (CAP) in patients with coronary heart disease by intravascular ultrasound. Data concerning the study design, patient characteristics, and outcomes were extracted. The significance of plaques regression was assessed by computing standardized mean difference (SMD) of the volume of CAP between the baseline and follow-up. SMD were calculated using fixed or random effects models. Results Twenty trials including 5910 patients with coronary heart disease were identified. Mean lowering LDL-C by 45.4% and to level 66.8 mg/dL in the group of patients with baseline mean LDL-C 123.7 mg/dL, mean lowering LDL-C by 48.8% and to level 60.6 mg/dL in the group of patients with baseline mean LDL-C 120 mg/dL, and mean lowering LDL-C by 40.4% and to level 77.8 mg/dL in the group of patients with baseline mean LDL-C 132.4 mg/dL could significantly reduce the volume of CAP at follow up (SMD −0.108 mm3, 95% CI −0.176 ~ −0.040, p = 0.002; SMD −0.156 mm3, 95% CI −0.235 ~ −0.078, p = 0.000; SMD −0.123 mm3, 95% CI −0.199 ~ −0.048, p = 0.001; respectively). LDL-C lowering by rosuvastatin (mean 33 mg daily) and atorvastatin (mean 60 mg daily) could significantly decrease the volumes of CAP at follow up (SMD −0.162 mm3, 95% CI: −0.234 ~ −0.081, p = 0.000; SMD −0.101, 95% CI: −0.184 ~ −0.019, p = 0.016; respectively). The mean duration of follow up was from 17 ~ 21 months. Conclusions Intensive lowering LDL-C (rosuvastatin

  8. Ultrasound

    MedlinePlus

    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 ...

  9. Ultrasound

    MedlinePlus

    Ultrasound is a useful procedure for monitoring the baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two- ... sound waves and appear dark or black. An ultrasound can supply vital information about a mother's pregnancy ...

  10. Analysis of the Usefulness of Optical Coherence Tomography and Intravascular Ultrasonography for the Examination of Rabbit Atherosclerotic Plaques.

    PubMed

    Zhang, Huawei; Zhang, Shanchun; Wang, Peng; Wang, Jinda; Yi, Guiyan; Zhou, Ying; Chen, Yundai

    2016-03-01

    In the present study, we aimed to establish a rabbit atherosclerosis model and examine atherosclerotic plaques by using optical coherence tomography (OCT) and intravascular ultrasonography (IVUS) to evaluate the clinical usefulness of these diagnostic tools in the detection of atherosclerotic plaques. Twenty healthy New Zealand rabbits were fed on a high-fat diet for 4 weeks and then subjected to abdominal aortic intimal injury. The OCT and IVUS were performed after 8 weeks. The distal and proximal plaque images were marked to observe the plaque thickness and features of the lesions at the tunica intima and tunica media. Moreover, a pathological examination was performed to evaluate the efficacies of OCT and IVUS. The mean (SD) plaque thickness on OCT and IVUS images was 386.5 (125.3) μm and 412.7 (165.8) μm, respectively. Pathological examinations indicated a mean (SD) plaque thickness of 360.2 (98.l) μm (P > 0.05). No significant differences were noted between the 2 methods. The intimal and medial thickness measured with OCT showed greater correlation with pathologically measured thickness (r = 0.95, P < 0.001 for OCT; r = 0.88, P < 0.001 for IVUS); in particular, the intimal thickness measurements on OCT showed a higher correlation (r = 0.98, P < 0.001). However, the measurements obtained using IVUS were not accurate. Thus, compared with IVUS, OCT was more accurate in determining the nature and thickness of vascular plaques. PMID:26561217

  11. In vivo near infrared fluorescence (NIRF) intravascular molecular imaging of inflammatory plaque, a multimodal approach to imaging of atherosclerosis.

    PubMed

    Calfon, Marcella A; Rosenthal, Amir; Mallas, Georgios; Mauskapf, Adam; Nudelman, R Nika; Ntziachristos, Vasilis; Jaffer, Farouc A

    2011-08-04

    technologies including angiography and intravascular ultrasound (IVUS), offers a unique and novel integrated multimodal molecular imaging technique that distinguishes inflammatory atheromata, and allows detection of intravascular NIRF signals in human-sized coronary arteries.

  12. IVUS-based histology of atherosclerotic plaques: improving longitudinal resolution

    NASA Astrophysics Data System (ADS)

    Taki, Arash; Pauly, Olivier; Setarehdan, S. Kamaledin; Unal, Gozde; Navab, Nassir

    2010-03-01

    Although Virtual Histology (VH) is the in-vivo gold standard for atherosclerosis plaque characterization in IVUS images, it suffers from a poor longitudinal resolution due to ECG-gating. In this paper, we propose an image-based approach to overcome this limitation. Since each tissue have different echogenic characteristics, they show in IVUS images different local frequency components. By using Redundant Wavelet Packet Transform (RWPT), IVUS images are decomposed in multiple sub-band images. To encode the textural statistics of each resulting image, run-length features are extracted from the neighborhood centered on each pixel. To provide the best discrimination power according to these features, relevant sub-bands are selected by using Local Discriminant Bases (LDB) algorithm in combination with Fisher's criterion. A structure of weighted multi-class SVM permits the classification of the extracted feature vectors into three tissue classes, namely fibro-fatty, necrotic core and dense calcified tissues. Results shows the superiority of our approach with an overall accuracy of 72% in comparison to methods based on Local Binary Pattern and Co-occurrence, which respectively give accuracy rates of 70% and 71%.

  13. Imminent Cardiac Risk Assessment via Optical Intravascular Biochemical Analysis

    SciTech Connect

    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.

  14. Ultrasound

    MedlinePlus

    ... reflect off body structures. A computer receives the waves and uses them to create a picture. Unlike with an x-ray or CT scan, this test does not use ionizing radiation. The test is done in the ultrasound ...

  15. [The usefulness of intravascular echography during the percutaneous dilatation of aortic coarctation].

    PubMed

    Goicolea, F J; Macaya, C; Iñíguez, A; Alfonso, F; Hernández Antolín, R; Vila i Costa, I; Zamorano, J; Egocheaga, I; Zarco, P

    1992-01-01

    An intravascular ultrasound study was performed in a patient, to assess the anatomy of aortic coarctation and the results obtained after percutaneous dilation with a balloon catheter. Intravascular ultrasound imaging provides important additional information, not obtainable with other diagnostic procedures, regarding aortic wall structure and thickness. After balloon dilation, aortic disruption was clearly observed, accounting, together with the stretching of the outer layers of the aortic wall, for the increase in aortic luminal area. Intravascular ultrasound permitted also the accurate assessment of the improvement obtained. Intravascular imaging was clearly superior not only to conventional angiography, but also to transesophageal echocardiography in detecting the mechanism of dilation. We conclude that ultravascular ultrasound, with the additional information that it provides, may help in the selection of patients for percutaneous dilation of the coarctation as well as contributing to the identification of the mechanism of dilation.

  16. Disseminated intravascular coagulation (DIC)

    MedlinePlus

    Levi M. Disseminated intravascular coagulation. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap ...

  17. Comparison of Intensive Versus Moderate Lipid-Lowering Therapy on Fibrous Cap and Atheroma Volume of Coronary Lipid-Rich Plaque Using Serial Optical Coherence Tomography and Intravascular Ultrasound Imaging.

    PubMed

    Hou, Jingbo; Xing, Lei; Jia, Haibo; Vergallo, Rocco; Soeda, Tsunerari; Minami, Yoshiyasu; Hu, Sining; Yang, Shuang; Zhang, Shaosong; Lee, Hang; Yu, Bo; Jang, Ik-Kyung

    2016-03-01

    Despite marked clinical benefit, reduction in atheroma volume with statin therapy is minimal. Changes in plaque composition may explain this discrepancy. We aimed in the present study to assess the effect of statin therapy on coronary plaque composition and plaque volume using serial multimodality imaging. From an open-label, single-blinded study, patients with angiographically mild-to-moderate lesion were randomized to receive atorvastatin 60 (AT 60) mg or atorvastatin 20 (AT 20) mg for 12 months. Optical coherence tomography was used to assess fibrous cap thickness (FCT) and intravascular ultrasound to assess atheroma burden at 3 time points: baseline, at 6 months, and at 12 months. Thirty-six lipid-rich plaques in 27 patients with AT 60 mg and 30 lipid-rich plaques in 19 patients with AT 20 mg were enrolled in this study. Low-density lipoprotein cholesterol level was significantly decreased at 6 months without further reduction at 12 months. AT 60 mg induced greater reduction in low-density lipoprotein cholesterol compared with AT 20 mg. Optical coherence tomography revealed continuous increase in FCT from baseline to 6 months and to 12 months in both groups. AT 60 mg induced greater increase in FCT compared with AT 20 mg at both follow-up points. The prevalence of thin-cap fibroatheroma and the presence of macrophage at 6 months were significantly lower in AT 60 mg compared with AT 20 mg. Plaque burden did not change significantly in both groups. In conclusion, both intensive and moderate statin therapy stabilizes coronary plaques, with a greater benefit in the intensive statin group. However, no significant changes in plaque volume were observed over time regardless of the intensity of statin therapy. PMID:26778524

  18. Effects of the PPARγ agonist pioglitazone on coronary atherosclerotic plaque composition and plaque progression in non-diabetic patients: a double-center, randomized controlled VH-IVUS pilot-trial.

    PubMed

    Christoph, Marian; Herold, Joerg; Berg-Holldack, Anna; Rauwolf, Thomas; Ziemssen, Tjalf; Schmeisser, Alexander; Weinert, Sönke; Ebner, Bernd; Said, Samir; Strasser, Ruth H; Braun-Dullaeus, Ruediger C

    2015-05-01

    Despite the advanced therapy with statins, antithrombotics and antihypertensive agents, the medical treatment of coronary artery disease is less than optimal. Therefore, additional therapeutic anti-atherosclerotic options are desirable. This VH-IVUS study (intravascular ultrasonography with virtual histology) was performed to assess the potential anti-atherogenic effect of the PPARγ agonist pioglitazone in non-diabetic patients. A total of 86 non-culprit atherosclerotic lesions in 54 patients with acute coronary syndrome were observed in a 9-month prospective, double-blind, and placebo-controlled IVUS study. Patients were randomized to receive either 30 mg pioglitazone (Pio) or placebo (Plac). As primary efficacy parameter, the change of relative plaque content of necrotic core was determined by serial VH-IVUS analyses. Main secondary endpoint was the change of total plaque volume. In contrast to placebo, in the pioglitazone-treated group, the relative plaque content of necrotic core decreased significantly (Pio -1.3 ± 6.9% vs. Plac +2.6 ± 6.5%, p < 0.01). In comparison to the placebo group, the plaques in pioglitazone-treated patients showed significantly greater reduction of the total plaque volume (Pio -16.1 ± 26.4 mm3 vs. Plac -1.8 ± 30.9 mm3, p = 0.02). Treatment with a PPARγ agonist in non-diabetic patients results in a coronary artery plaque stabilization on top of usual medical care.

  19. Infections and intravascular devices.

    PubMed

    Elliott, T S; Faroqui, M H

    Complications associated with intravascular devices include infections mainly caused by Staphylococcus epidermis and S. aureus. The reported incidence of these infections varies. Several factors influence the propensity for catheter infections. We recommend strategies for the prevention and treatment of catheter-related sepsis. PMID:1422561

  20. An analog integrated circuit beamformer for high-frequency medical ultrasound imaging.

    PubMed

    Gurun, Gokce; Zahorian, Jaime S; Sisman, Alper; Karaman, Mustafa; Hasler, Paul E; Degertekin, F Levent

    2012-10-01

    We designed and fabricated a dynamic receive beamformer integrated circuit (IC) in 0.35-μm CMOS technology. This beamformer IC is suitable for integration with an annular array transducer for high-frequency (30-50 MHz) intravascular ultrasound (IVUS) imaging. The beamformer IC consists of receive preamplifiers, an analog dynamic delay-and-sum beamformer, and buffers for 8 receive channels. To form an analog dynamic delay line we designed an analog delay cell based on the current-mode first-order all-pass filter topology, as the basic building block. To increase the bandwidth of the delay cell, we explored an enhancement technique on the current mirrors. This technique improved the overall bandwidth of the delay line by a factor of 6. Each delay cell consumes 2.1-mW of power and is capable of generating a tunable time delay between 1.75 ns to 2.5 ns. We successfully integrated the fabricated beamformer IC with an 8-element annular array. Experimental test results demonstrated the desired buffering, preamplification and delaying capabilities of the beamformer.

  1. How Is Disseminated Intravascular Coagulation Treated?

    MedlinePlus

    ... 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 ...

  2. Disseminated intravascular coagulation.

    PubMed

    Gando, Satoshi; Levi, Marcel; Toh, Cheng-Hock

    2016-01-01

    Disseminated intravascular coagulation (DIC) is an acquired syndrome characterized by widespread intravascular activation of coagulation that can be caused by infectious insults (such as sepsis) and non-infectious insults (such as trauma). The main pathophysiological mechanisms of DIC are inflammatory cytokine-initiated activation of tissue factor-dependent coagulation, insufficient control of anticoagulant pathways and plasminogen activator inhibitor 1-mediated suppression of fibrinolysis. Together, these changes give rise to endothelial dysfunction and microvascular thrombosis, which can cause organ dysfunction and seriously affect patient prognosis. Recent observations have pointed to an important role for extracellular DNA and DNA-binding proteins, such as histones, in the pathogenesis of DIC. The International Society on Thrombosis and Haemostasis (ISTH) established a DIC diagnostic scoring system consisting of global haemostatic test parameters. This scoring system has now been well validated in diverse clinical settings. The theoretical cornerstone of DIC management is the specific and vigorous treatment of the underlying conditions, and DIC should be simultaneously managed to improve patient outcomes. The ISTH guidance for the treatment of DIC recommends treatment strategies that are based on current evidence. In this Primer, we provide an updated overview of the pathophysiology, diagnosis and management of DIC and discuss the future directions of basic and clinical research in this field. PMID:27250996

  3. New intravascular flow sensor using fiber optics

    NASA Astrophysics Data System (ADS)

    Stenow, Erik N. D.

    1994-12-01

    A new sensor using fiber optics is suggested for blood flow measurements in small vessels. The sensor principle and a first evaluation on a flow model are presented. The new sensor uses small CO2 gas bubbles as flow markers for optical detection. When the bubbles pass an optical window, light emitted from one fiber is reflected and scattered into another fiber. The sensor has been proven to work in a 3 mm flow model using two 110 micrometers optical fibers and a 100 micrometers steel capillary inserted into a 1 mm guide wire. The evaluation of a sensor archetype shows that the new sensor provides a promising method for intravascular blood flow measurement in small vessels. The linearity for steady state flow is studied in the flow interval 30 - 130 ml/min. comparison with ultrasound Doppler flowmetry was performed for pulsatile flow in the interval 25 - 125 ml/min. with a pulse length between 0.5 and 2 s. The use of intravascular administered CO2 in small volumes is harmless because the gas is rapidly dissolved in whole blood.

  4. Positron autoradiography for intravascular imaging: feasibility evaluation

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Xu, Tong; Ducote, Justin L.; Easwaramoorthy, Balasubramaniam; Mukherjee, Jogeshwar; Molloi, Sabee

    2006-02-01

    Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sudden death. Morphological imaging such as angiography or intravascular ultrasound cannot determine inflammation status of the plaque. A radiotracer such as 18F-FDG is accumulated in vulnerable plaques due to higher metabolic activity of the inflamed cap and could be used to detect a vulnerable plaque. However, positron emission tomography (PET) cannot detect the FDG-labelled plaques because of respiratory and heart motions, small size and low activity of the plaques. Plaques can be detected using a miniature particle (positron) detector inserted into the artery. In this work, a new detector concept is investigated for intravascular imaging of the plaques. The detector consists of a storage phosphor tip bound to the end of an intravascular catheter. It can be inserted into an artery, absorb the 18F-FDG positrons from the plaques, withdrawn from the artery and read out. Length and diameter of the storage phosphor tip can be matched to the length and the diameter of the artery. Monte Carlo simulations and experimental evaluations of coronary plaque imaging with the proposed detector were performed. It was shown that the sensitivity of the storage phosphor detector to the positrons of 18F-FDG is sufficient to detect coronary plaques with 1 mm and 2 mm sizes and 590 Bq and 1180 Bq activities in the arteries with 2 mm and 3 mm diameters, respectively. An experimental study was performed using plastic tubes with 2 mm diameter filled with an FDG solution, which simulates blood. FDG spots simulating plaques were placed over the surface of the tube. A phosphor tip was inserted into the tube and imaged the plaques. Exposure time was 1 min in all simulations and

  5. [The role of non-angiographic observations (IVUS, angioscopy, doppler) in coronary stenting].

    PubMed

    Alfonso, F; Goicolea, J; Segovia, J; Hernández, R; Fernández-Ortiz, A; Bañuelos, C; Macaya, C

    1997-01-01

    Coronary stenting is increasingly used during transcatheter coronary therapy. Coronary angiography, mainly since the advent of quantitative angiography, provides an effective tool to obtain excellent clinical results with coronary stenting. However, during this procedure some limitations inherent to the angiographic techniques may become apparent. Accordingly, great enthusiasm has been generated regarding the potential value of alternative diagnostic techniques to guide coronary stenting. Intravascular ultrasound is able to study the arterial wall and provides a unique tool to assess stent expansion, apposition and symmetry. Therefore, this technique is increasingly used to optimize stent deployment. Coronary angioscopy directly visualizes stent expansion and is able to precisely recognize protrusion of redundant fronds of tissue or residual dissections within the stent struts. In addition, this technique is the procedure of choice to identify intracoronary thrombus. Intracoronary Doppler permits the application in the catheterization laboratory of sophisticated methods of functional assessment of lesion severity. Coronary stenting allows a faster and complete normalization of coronary flow reserve than balloon angioplasty. Thus, all these new techniques of intracoronary diagnosis provide unique and useful information, which is complementary to that obtained with angiography, potentially useful during coronary stenting.

  6. Intravascular photoacoustic tomography for characterization of atherosclerotic lipid and inflammation

    NASA Astrophysics Data System (ADS)

    Zhang, Jian; Qin, Huan; Shi, Yujiao; Yang, Sihua; Xing, Da

    2014-09-01

    Photoacoustic imaging is a fast growing imaging technology depending on its high optical resolution of optics while taking the advantage of the high penetration depth of ultrasound. In this paper, we demonstrate the new progress in the photoacoustic imaging. Atherosclerosis is characterized by a progressive build-up of lipid in the arterial wall, which is known as plaque. Histological studies demonstrate that the primary cause of acute cardiovascular events is the rupture of atherosclerotic plaques. Lipid and inflammation within the plaque are related to influence the propensity of plaques to disrupt. Photoacoustic intravascular tomography (IVPAT) holds a great advantage in providing comprehensive morphological and functional information of plaques. Lipid relative concentration maps of atherosclerotic aorta were obtained and compared with histology. Furthermore, by selectively targeting the intravascular inflammatory cytokines, IVPAT is also capable of mapping the inflamed area and determining the degree of inflammation.

  7. Ultrasound pregnancy

    MedlinePlus

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

  8. Vascular ultrasound for atherosclerosis imaging

    PubMed Central

    de Korte, Chris L.; Hansen, Hendrik H. G.; van der Steen, Anton F. W.

    2011-01-01

    Cardiovascular disease is a leading cause of death in the Western world. Therefore, detection and quantification of atherosclerotic disease is of paramount importance to monitor treatment and possible prevention of acute events. Vascular ultrasound is an excellent technique to assess the geometry of vessel walls and plaques. The high temporal as well as spatial resolution allows quantification of luminal area and plaque size and volume. While carotid arteries can be imaged non-invasively, scanning of coronary arteries requires invasive intravascular catheters. Both techniques have already demonstrated their clinical applicability. Using linear array technology, detection of disease as well as monitoring of pharmaceutical treatment in carotid arteries are feasible. Data acquired with intravascular ultrasound catheters have proved to be especially beneficial in understanding the development of atherosclerotic disease in coronary arteries. With the introduction of vascular elastography not only the geometry of plaques but also the risk for rupture of plaques might be identified. These so-called vulnerable plaques are frequently not flow-limiting and rupture of these plaques is responsible for the majority of cerebral and cardiac ischaemic events. Intravascular ultrasound elastography studies have demonstrated a high correlation between high strain and vulnerable plaque features, both ex vivo and in vivo. Additionally, pharmaceutical intervention could be monitored using this technique. Non-invasive vascular elastography has recently been developed for carotid applications by using compound scanning. Validation and initial clinical evaluation is currently being performed. Since abundance of vasa vasorum (VV) is correlated with vulnerable plaque development, quantification of VV might be a unique tool to even prevent this from happening. Using ultrasound contrast agents, it has been demonstrated that VV can be identified and quantified. Although far from routine

  9. Intravascular adenomyomatosis: expanding the morphologic spectrum of intravascular leiomyomatosis.

    PubMed

    Hirschowitz, Lynn; Mayall, Frederick G; Ganesan, Raji; McCluggage, W Glenn

    2013-09-01

    Intravascular leiomyomatosis (IVL) is characterized by the presence of smooth muscle in venous and lymphatic spaces within the myometrium. Although the intravascular component usually consists solely of typical smooth muscle or variants of smooth muscle differentiation, we report 5 cases in which the intravascular component also included endometrioid glandular and stromal elements. We propose the term "intravenous adenomyomatosis" to describe this unusual variant of IVL. The mean age of the patients in this series was 50.2 years, slightly older than that of patients with conventional IVL. In addition to intravenous adenomyomatosis, both adenomyosis and leiomyomas were identified in all of our cases, supporting the hypothesis that the intravascular smooth muscle component in IVL is derived from associated myometrial pathology rather than from vessel walls. In our series, intravenous adenomyomatosis had a similar benign clinical behavior to most cases of IVL with no metastatic or recurrent disease identified at follow-up in 4 cases for which follow-up information was available. The main differential diagnoses are adenomyosis with vascular involvement, low-grade endometrial stromal sarcoma (ESS), including ESS with smooth muscle and glandular differentiation, and adenosarcoma with lymphovascular invasion. The possibility of intravenous adenomyomatosis should be borne in mind when considering these diagnoses, particularly ESS and adenosarcoma, which have different implications for patient management and prognosis.

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

    PubMed Central

    Roldan, Carlos J.; Paniagua, Linda

    2015-01-01

    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. PMID:26587087

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

    PubMed

    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.

  12. Endosulfan poisoning with intravascular hemolysis.

    PubMed

    Ramaswamy, Shankar; Puri, Goverdhan Dutt; Rajeev, Subramanyam

    2008-04-01

    We describe a 26-year-old female patient, who had attempted suicide with Endosulfan, and who presented to the Emergency Department with status epilepticus. She subsequently developed hypotension refractory to inotropes, intravascular hemolysis, disseminated intravascular coagulation (DIC), metabolic acidosis and, finally, cardiac arrest and death. Endosulfan is a chlorinated insecticide that causes central nervous system hyperstimulation. It is absorbed from the gastrointestinal tract, skin, and respiratory tract, and leads to nausea, vomiting, paraesthesia, giddiness, convulsion, coma, respiratory failure, and congestive cardiac failure. Hepatic, renal and myocardial toxicity, agranulocytosis, aplastic anemia, cerebral edema, DIC, thrombocytopenia, and skin reaction also have been reported. Management includes decontamination of skin and gastrointestinal tract, supportive care including treatment of status epilepticus, dysrhythmias, and mechanical ventilation. Mortality and morbidity rates are very high and there is no specific antidote. Atropine and catecholamines should be avoided.

  13. Improved dosimetry techniques for intravascular brachytherapy

    NASA Astrophysics Data System (ADS)

    Sehgal, Varun

    using Monte Carlo-based radiation transport code MCNP and tabulated for a range of different coronary geometries and different radionuclides. A new technique using imaging techniques such as intravascular ultrasound and angiography to assess dosimetry for realistic coronary arteries is also introduced. The results indicate the need for accurate assessment of post-intervention clinical measurements such as minimal lumen diameter and residual plaque burden and incorporating them into dose calculations.

  14. [The correlation between measurements performed by intravascular echography and quantitative digital angiography in large- and small-caliber arteries].

    PubMed

    Zamorano, J; Macaya, C; Alfonso, F; Goicolea, J; Iñíguez, A; Hernández-Antolín, R A; Ge, J; Zarco, P; Erbel, R; Meyer, J

    1992-04-01

    Intravascular ultrasound is a new promising technique that appears as a very useful complement to standard angiography in the study of atherosclerosis. Specifically, intravascular ultrasound provides by itself, information of great value concerning vessel wall characteristics. Nevertheless, before taking any decision with the results provided by this new technique, we must validate this information with that provided by other more conventional techniques like standard angiography. Accordingly, we have analyzed in 25 patients, 50 images of the abdominal aorta and 77 images of the coronary arteries taken from arterial segments free of atherosclerotic involvement. With the use of a calibrated small grid located over the patient's thorax, we have analyzed "in the same points" the images obtained with intravascular ultrasound and those provided by contrast angiography using a quantitative angiographic analysis. In the abdominal aorta the vessel diameter measured by intravascular ultrasound and angiography was 17.8 +/- 0.39 mm vs 18.6 +/- 0.42 mm (NS), whereas in the coronary arteries it was 2.76 +/- 0.39 mm vs 2.98 +/- 0.37 mm (NS), respectively. The correlation between both techniques was good for both types of arteries (r = 0.93 in the abdominal aorta and r = 0.87 in the coronary arteries). We conclude, that in our experience and with the methodology used, there is a good correlation between the measurements of the vessel diameters obtained by both intravascular ultrasound and digital angiography in arteries of different sizes, being the correlation even better in large arteries.

  15. Fibrinolysis in disseminated intravascular coagulation.

    PubMed

    Hack, C E

    2001-12-01

    Studies in experimental models for sepsis, the most common cause of disseminated intravascular coagulation (DIC), have put forward the concept of a procoagulant state that is characterized by thrombin generation exceeding that of plasmin. Convincing evidence indicates that this imbalance between coagulation and fibrinolysis is due to increased levels of plasminogen activator inhibitor type 1 (PAI-1). Levels of this fibrinolysis inhibitor indeed correlate with outcome and severity of multiple organ failure in patients with sepsis, as well as in patients with DIC from other causes. Hence we suggest that PAI-1 constitutes an important target for therapy in patients with DIC.

  16. How many IVUs can we install without sacrificing 16-mA operation?

    SciTech Connect

    Chae, Y.-C.; Accelerator Systems Division

    2010-01-21

    In this note, the authors examine the following hypothetical scenario: replacing existing 8-mm gap chambers with an in-vacuum undulator (IVU) one by one until they hit the boundary condition of 16-mA single-bunch operation. This is a continuation of a previous technical note on the topics of IVUs. The authors evaluated the impedance of IVU for various gaps. The result showed that the present 8-mm gap chamber can be replaced by the 8.754-mm IVU while maintaining the same 16-mA operational current. The estimates in this note make certain simplifying assumptions bearing on the effectiveness of nonlinear tapers. Subsequent evaluation of the effect of such tapers for APS parameters has cst considerable doubt on their usefulness. This results from the fact that APS has a fairly short electron bunch compared to the vacuum chamber dimensions. Investigation of other methods to decrease the impedance is on-going.

  17. Comparison of the Effect of Rosuvastatin 2.5 mg vs 20 mg on Coronary Plaque Determined by Angioscopy and Intravascular Ultrasound in Japanese With Stable Angina Pectoris (from the Aggressive Lipid-Lowering Treatment Approach Using Intensive Rosuvastatin for Vulnerable Coronary Artery Plaque [ALTAIR] Randomized Trial).

    PubMed

    Takayama, Tadateru; Komatsu, Sei; Ueda, Yasunori; Fukushima, Seiji; Hiro, Takafumi; Hirayama, Atsushi; Saito, Satoshi

    2016-04-15

    Diminishing yellow color, evaluated by coronary angioscopy, is associated with plaque stabilization and regression. Our aim was to assess the effect of aggressive lipid-lowering therapy with rosuvastatin on plaque regression and instability. Thirty-seven patients with stable angina or silent myocardial ischemia who planned to undergo elective percutaneous coronary intervention and had angioscopic yellow plaques of grade 2 or more were randomized to high-dose (group H, 20 mg/day, n = 18) or low-dose (group L, 2.5 mg/day, n = 19) rosuvastatin therapy for 48 weeks. Yellow plaque was graded on a 4-point scale of 0 (white) to 3 (bright yellow) by angioscopy, and plaque volume was determined by intravascular ultrasound for plaques with a length of 5 to 15 mm. Color and volume were assessed at baseline and after 48 weeks by the investigators blinded to the rosuvastatin dosage, and were compared between the 2 dosing groups. The level of low-density lipoprotein-cholesterol decreased from 130.3 ± 25.5 mg/dl to 61.7 ± 16.5 mg/dl (-50 ± 19%: high intensity) in group H (p <0.001) and from 130.9 ± 28.5 mg/dl to 89.7 ± 29.0 mg/dl (-30 ± 22%: moderate intensity) in group L (mean ± SD, p <0.001). The average color grade of yellow plaques decreased from 2.0 to 1.5 in group H (p <0.001) and from 2.0 to 1.6 in group L (p <0.001) after 48 weeks. Plaque volume decreased significantly in group H but not in group L. The percent change in plaque volume was significantly larger in group H than in group L (p = 0.005). In conclusion, both high-dose and low-dose rosuvastatin increased plaque stability. However, high-dose rosuvastatin was more effective than low-dose rosuvastatin in inducing plaque volume regression. Clinical Trial Registration No: UMIN-CTR, UMIN000003276. PMID:26879069

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Focused intravascular ultrasonic probe using dimpled transducer elements.

    PubMed

    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. PMID:25108608

  20. Acute Disseminated Intravascular Coagulation in Neuroendocrine Carcinoma

    PubMed Central

    Teh, Ru-Wen; Tsoi, Daphne T.

    2012-01-01

    Malignancy is a common cause of disseminated intravascular coagulation and usually presents as a chronic disorder in solid organ tumours. We present a rare case of recurrent acute disseminated intravascular coagulation in neuroendocrine carcinoma after manipulation, firstly, by core biopsy and, later, by cytotoxic therapy causing a release of procoagulants and cytokines from lysed tumour cells. This is reminiscent of tumour lysis syndrome where massive quantities of intracellular electrolytes and nucleic acid are released, causing acute metabolic imbalance and renal failure. This case highlights the potential complication of acute disseminated intravascular coagulation after trauma to malignant cells. PMID:23139666

  1. Intravascular Myopericytoma in the Heel: Case Report and Literature Review

    PubMed Central

    Valero, José; Salcini, José L.; Gordillo, Luis; Gallart, José; González, David; Deus, Javier; Lahoz, Manuel

    2015-01-01

    Abstract Intravascular myopericytoma (IVMP), regarded as a variant of myopericytoma, is a rare tumor. Very few cases have been described, none in the foot. The first case of IVMP located in the heel of the foot is described in this article. A literature review is reported of all cases of IVMP published in the English literature. A 48-year-old man possessed an IVMP on the heel of the right foot. The physical examination and histopathological and ultrasound studies are described. The literature review yielded 5 cases of IVMP, 2 of which were in the thigh and 1 each in the oral mucosa, the periorbital region, and the leg. The possibility that these lesions may be malignant suggests that the histopathological study of vascular tumors should include immunohistochemical tests. PMID:25789958

  2. Disseminated intravascular coagulation in sepsis.

    PubMed

    Zeerleder, Sacha; Hack, C Erik; Wuillemin, Walter A

    2005-10-01

    Disseminated intravascular coagulation is a frequent complication of sepsis. Coagulation activation, inhibition of fibrinolysis, and consumption of coagulation inhibitors lead to a procoagulant state resulting in inadequate fibrin removal and fibrin deposition in the microvasculature. As a consequence, microvascular thrombosis contributes to promotion of organ dysfunction. Recently, three randomized, double-blind, placebo-controlled trials investigated the efficacy of antithrombin, activated protein C (APC), and tissue factor pathway inhibitor, respectively, in sepsis patients. A significant reduction in mortality was demonstrated in the APC trial. In this article, we first discuss the physiology of coagulation and fibrinolysis activation. Then, the pathophysiology of coagulation activation, consumption of coagulation inhibitors, and the inhibition of fibrinolysis leading to a procoagulant state are described in more detail. Moreover, therapeutic concepts as well as the three randomized, double-blind, placebo-controlled studies are discussed.

  3. Obstetrical disseminated intravascular coagulation score.

    PubMed

    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.

  4. Treatment of Disseminated Intravascular Coagulation.

    PubMed

    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.

  5. Pulmonary intravascular lipid in neonatal necropsy specimens.

    PubMed

    Puntis, J W; Rushton, D I

    1991-01-01

    The lungs of 482 liveborn infants were examined at necropsy for the presence of intravascular lipid. Forty one patients had received parenteral feeding (including lipid emulsion in 30), and 441 had died before starting feeds or had received enteral feeds alone. Tissue was processed into wax and then stained with Sudan black; intravascular lipid was found in 15 of 30 infants who had received intravenous fat (Intralipid), but in no others. Those patients with positive lipid staining had received significantly more fat during parenteral nutrition than those in whom intravascular lipid was not found but the two groups were otherwise clinically indistinguishable. Using this staining technique intravascular lipid can be shown relatively often, although only in patients who have received intravenous lipid emulsion. The location of fat, predominantly in small pulmonary capillaries, and the absence of lipid emboli in other organs, suggests that lipid coalescence takes place before death and is not a postmortem artefact. The clinical relevance remains uncertain. PMID:1899990

  6. Pulmonary intravascular lipid in neonatal necropsy specimens.

    PubMed

    Puntis, J W; Rushton, D I

    1991-01-01

    The lungs of 482 liveborn infants were examined at necropsy for the presence of intravascular lipid. Forty one patients had received parenteral feeding (including lipid emulsion in 30), and 441 had died before starting feeds or had received enteral feeds alone. Tissue was processed into wax and then stained with Sudan black; intravascular lipid was found in 15 of 30 infants who had received intravenous fat (Intralipid), but in no others. Those patients with positive lipid staining had received significantly more fat during parenteral nutrition than those in whom intravascular lipid was not found but the two groups were otherwise clinically indistinguishable. Using this staining technique intravascular lipid can be shown relatively often, although only in patients who have received intravenous lipid emulsion. The location of fat, predominantly in small pulmonary capillaries, and the absence of lipid emboli in other organs, suggests that lipid coalescence takes place before death and is not a postmortem artefact. The clinical relevance remains uncertain.

  7. Intravascular Optical-Resolution Photoacoustic Tomography with a 1.1 mm Diameter Catheter

    PubMed Central

    Bai, Xiaosong; Gong, Xiaojing; Hau, William; Lin, Riqiang; Zheng, Jiaxiang; Liu, Chengbo; Zeng, Chengzhi; Zou, Xin; Zheng, Hairong; Song, Liang

    2014-01-01

    Photoacoustic imaging is an emerging technology that can provide anatomic, functional, and molecular information about biological tissue. Intravascular spectroscopic and molecular photoacoustic imaging can potentially improve the identification of atherosclerotic plaque composition, the detection of inflammation, and ultimately the risk stratification of atherosclerosis. In this study, a first-of-its-kind intravascular optical-resolution photoacoustic tomography (OR-PAT) system with a 1.1 mm diameter catheter is developed, offering optical-diffraction limited transverse resolution as fine as 19.6 μm, ∼10-fold finer than that of conventional intravascular photoacoustic and ultrasonic imaging. To offer complementary imaging information and depth, the system also acquires co-registered intravascular ultrasound images in parallel. Imaging of an iliac stent and a lipid phantom shows that the high resolution and contrast of OR-PAT can enable improved stent implantation guidance and lipid identification. In the future, these capabilities may ultimately improve the diagnosis and interventional treatment of vulnerable atherosclerotic plaques, which are prone to cause thrombotic complications such as myocardial infarction and stroke. PMID:24651256

  8. First reported revascularization of complex occlusion of the right coronary artery using the IVUS-guided reverse CART technique via a gastroepiploic artery graft.

    PubMed

    Dai, Jian; Katoh, Osamu; Zhou, Hua; Kyo, Eisho

    2016-02-01

    When patients who have previously undergone coronary artery bypass graft surgery develop ischemia symptoms that cannot be controlled by optimal medical therapy, repeat revascularization is indicated. The revascularization strategy should be based on individual clinical and anatomical characteristics. We report here a challenging patient who presented with recurrent stable angina due to worsening of a proximal right coronary artery (RCA) stenosis to chronic total occlusion (CTO) after anastomosis of the right gastroepiploic artery (GEA) to the posterior descending artery. A soft guidewire was advanced through the right GEA collateral channel to the distal end of the CTO, but the dedicated CTO guidewires could not be advanced across the severely calcified CTO using the retrograde wire crossing or kissing wire techniques. The RCA was eventually revascularized by implantation of drug-eluting stents using the intravascular ultrasound-guided reverse controlled antegrade and retrograde subintimal tracking technique.

  9. Assessment of coronary vasomotion by intracoronary ultrasound

    NASA Astrophysics Data System (ADS)

    Dupouy, Patrick J.; Dubois-Rande, Jean Luc; Pelle, Gabriel; Gallot, Dominique; Geschwind, Herbert J.

    1993-06-01

    Recently, new intravascular ultrasound devices for intracoronary use became available. The aim of the study was to evaluate the accuracy of intravascular ultrasound for the assessment of coronary artery vasomotion and endothelial function in patients with atherosclerosis. Twenty patients with luminal irregularities on coronary angiogram and a high cholesterol level (287 +/- 19 mg/dl) (group 1) and 6 patients with angiographically smooth arteries and a minimally elevated cholesterol level (197 +/- 12 mg/dl) (group 2) were studied. A mechanical intravascular ultrasound probe (4.3 French, 30 MHz, Cardiovascular Imaging Systems) was placed into the proximal segment of the coronary artery. Off-line measurements of the lumen area and calculation of mean intimal thickness indice was performed using digitized ultrasound images. Endothelial function was studied during a sympathetic stimulation by a cold pressor test and after intracoronary administration of papaverine and linsidomine. Mean intimal thickness was higher in group 1 than in group 2 (1.52 +/- 0.64 mm vs. 0.18 +/- 0.08 mm, p < 0.001). Linsidomine infusion induced a significant vasodilating effect in both groups (p < 0.001).

  10. [A method for studying intravascular platelet aggregation in vitro].

    PubMed

    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.

  11. Intravascular leiomyomatosis: an exceptional entity.

    PubMed

    Brunel, I; Iacoponi, S; Hernandez, A; Diestro, M D; De Santiago, J; Zapardiel, I

    2016-01-01

    Intravenous leiomyomatosis (IVL) is a rare benign condition characterized by the proliferation of smooth muscle cells originating from either the uterine venous wall or a uterine myoma. This leiomyomatosis extends most frequently to pelvic vessels, but also occasionally into the inferior vena cava and right cardiac chambers. Preoperative diagnosis is difficult and it should be suspected in the presence of cardiac or pelvic masses in women who have undergone hysterectomy or myomectomy previously. The treatment is hysterectomy, normally associated with a bilateral oophorectomy and removing the mass or metastasis if any. The post-surgical follow-up should be performed at long-term and include exploration and imaging, either ultrasound or MRI. The association of antiestrogenic drugs can be useful for disease control, especially in cases where oophorectomy is not performed and the tumor cannot be removed completely. PMID:27328511

  12. Ultrasound Backscattering Is Anisotropic in Bovine Articular Cartilage.

    PubMed

    Inkinen, Satu I; Liukkonen, Jukka; Tiitu, Virpi; Virén, Tuomas; Jurvelin, Jukka S; Töyräs, Juha

    2015-07-01

    Collagen, proteoglycans and chondrocytes can contribute to ultrasound scattering in articular cartilage. However, anisotropy of ultrasound scattering in cartilage is not fully characterized. We investigate this using a clinical intravascular ultrasound device with ultrasound frequencies of 9 and 40 MHz. Osteochondral samples were obtained from intact bovine patellas, and cartilage was imaged in two perpendicular directions: through articular and lateral surfaces. At both frequencies, ultrasound backscattering was higher (p < 0.05) when measured through the lateral surface of cartilage. In addition, the composition and structure of articular cartilage were investigated with multiple reference methods involving light microscopy, digital densitometry, polarized light microscopy and Fourier infrared imaging. Reference methods indicated that acoustic anisotropy of ultrasound scattering arises mainly from non-uniform distribution of chondrocytes and anisotropic orientation of collagen fibers. To conclude, ultrasound backscattering in articular cartilage was found to be anisotropic and dependent on the frequency in use. PMID:25933711

  13. Ultrasound Backscattering Is Anisotropic in Bovine Articular Cartilage.

    PubMed

    Inkinen, Satu I; Liukkonen, Jukka; Tiitu, Virpi; Virén, Tuomas; Jurvelin, Jukka S; Töyräs, Juha

    2015-07-01

    Collagen, proteoglycans and chondrocytes can contribute to ultrasound scattering in articular cartilage. However, anisotropy of ultrasound scattering in cartilage is not fully characterized. We investigate this using a clinical intravascular ultrasound device with ultrasound frequencies of 9 and 40 MHz. Osteochondral samples were obtained from intact bovine patellas, and cartilage was imaged in two perpendicular directions: through articular and lateral surfaces. At both frequencies, ultrasound backscattering was higher (p < 0.05) when measured through the lateral surface of cartilage. In addition, the composition and structure of articular cartilage were investigated with multiple reference methods involving light microscopy, digital densitometry, polarized light microscopy and Fourier infrared imaging. Reference methods indicated that acoustic anisotropy of ultrasound scattering arises mainly from non-uniform distribution of chondrocytes and anisotropic orientation of collagen fibers. To conclude, ultrasound backscattering in articular cartilage was found to be anisotropic and dependent on the frequency in use.

  14. [Possibilities for cardiac defibrillation using intravascular electrodes].

    PubMed

    Amosov, G G; Tolpekin, V E; Gasanov, E K; Fomichev, D I

    1987-05-01

    The efficiency of electric defibrillation of the heart was assessed in 17 experiments where the position of action electrodes varied. It is suggested that intravascular application of one electrode plus extravascular application of the other gives the optimum effect. The duration of unassisted reversible fibrillation averaged 3 minutes.

  15. Estimating the actual dose delivered by intravascular coronary brachytherapy using geometrically correct 3D modeling

    NASA Astrophysics Data System (ADS)

    Wahle, Andreas; Lopez, John J.; Pennington, Edward C.; Meeks, Sanford L.; Braddy, Kathleen C.; Fox, James M.; Brennan, Theresa M. H.; Buatti, John M.; Rossen, James D.; Sonka, Milan

    2003-05-01

    Intravascular brachytherapy has shown to reduce re-occurrence of in-stent restenosis in coronary arteries. For beta radiation, application time is determined from source activity and the angiographically estimated vessel diameter. Conventionally used dosing models assume a straight vessel with the catheter centered and a constant-diameter circular cross section. Aim of this study was to compare the actual dose delivered during in-vivo intravascular brachytherapy with the target range determined from the patient's prescribed dose. Furthermore, differences in dose distribution between a simplified tubular model (STM) and a geometrically correct 3-D model (GCM) obtained from fusion between biplane angiography and intravascular ultrasound were quantified. The tissue enclosed by the segmented lumen/plaque and media/adventitia borders was simulated using a structured finite-element mesh. The beta-radiation sources were modeled as 3-D objects in their angiographically determined locations. The accumulated dose was estimated using a fixed distance function based on the patient-specific radiation parameters. For visualization, the data was converted to VRML with the accumulated doses represented by color encoding. The statistical comparison between STM and GCM models in 8 patients showed that the STM significantly underestimates the dose delivered and its variability. The analysis revealed substantial deviations from the target dose range in curved vessels.

  16. Duplex ultrasound

    MedlinePlus

    Vascular ultrasound; Peripheral vascular ultrasound ... Deane CR, Goss DE. Peripheral arteries and veins. In: Allan PL, Baxter GM, Weston MJ, eds. Allan & Baxter: Clinical Ultrasound . 3rd ed. Philadelphia, PA: Elsevier ...

  17. Prostate Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  18. Ultrasound -- Pelvis

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  19. Hip Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  20. Ultrasound -- Vascular

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  1. Musculoskeletal Ultrasound

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  2. Ultrasound - Scrotum

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  3. Intravascular access in pediatric cardiac arrest.

    PubMed

    Brunette, D D; Fischer, R

    1988-11-01

    All cases of patients aged less than 48 months who presented in cardiac arrest to the Hennepin County Medical Center's emergency department (ED) during the years 1984 to 1986 were reviewed retrospectively. The ED record, initial and subsequent chest radiographs, hospital charts, and autopsy reports were analyzed. A total of 33 cases were reviewed. The average patient age was 5 months. The average time needed to establish intravascular access was 7.9 +/- 4.2 minutes. Success rates were 77% for central venous catheterization, 81% for surgical vein cutdown, 83% for intraosseous infusion, and 17% for percutaneous peripheral catheterization. Percutaneous peripheral catheterization, when successful, and bone marrow needle placement were the fastest methods of obtaining intravascular access. There were no major immediate complications, and delayed complications were minimal. Attempts at peripheral intravenous catheter placement should be brief, with rapid progression to intraosseous infusion if peripheral attempts are not successful. PMID:3178949

  4. [Intravascular lymphoma: Report of one case].

    PubMed

    Young, Pablo; Massa, María; Finn, Bárbara C; Fleire, Gonzalo; Stemmelin, Germán R; Ruades, Amanda; Sutovsky, Daniel; Casas, José G; Dezanzo, Pablo; Vigovich, Félix; Bruetman, Julio E

    2015-08-01

    Intravascular lymphoma is a rare subtype of extranodal diffuse large B-cell lymphoma characterized by clonal proliferation of lymphocytes inside of small and medium caliber vessels. Its incidence is estimated at one case per million. The clinical picture is very variable, but frequently has skin and central nervous system involvement. It is diagnosed by demonstrating pathological blood vessel infiltration by lymphoma cells. We report a 44 years old male presenting with fever, malaise and erythematous lesions in the abdominal wall. An abdominal wall biopsy showed dilated vascular vessels with atypical cells in their lumen, compatible with large B-cell intravascular lymphoma. He was treated with rituximab, cyclophosphamide, adriamycin, vincristine and prednisone and an autologous hematopoietic stem cell transplantation, achieving a complete remission that has lasted two years. PMID:26436939

  5. Techniques for Intravascular Foreign Body Retrieval

    SciTech Connect

    Woodhouse, Joe B.; Uberoi, Raman

    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.

  6. [Disseminated intravascular coagulation in solid tumours].

    PubMed

    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.

  7. Percutaneous Retrieval of Chronic Intravascular Foreign Bodies

    SciTech Connect

    Savage, Clare; Ozkan, Orhan S.; Walser, Eric M.; Wang Dongfang; Zwischenberger, Joseph B.

    2003-09-15

    To evaluate the feasibility of intravascular retrieval of chronic foreign bodies, we retrospectively reviewed an 8 year experience (1993-2001) of percutaneous retrieval of chronically retained intravascular foreign bodies (n = 6). In 6 of 6 cases (4 catheter fragments, 2 guidewires), 5-90 days elapsed before retrieval via the femoral or internal jugular vein. Under fluoroscopy, we determined the foreign body's course, position and size. A guidewire was advanced through a multipurpose catheter to the foreign body. The multipurpose catheter was replaced with a gooseneck snare catheter and the snare advanced to grasp and remove the foreign body. Percutaneous retrieval was successful in all 6 cases. One patient experienced mild hemoptysis, which resolved within 24 hr of observation. No patient experienced long-term sequelae. Given the potential life-threatening complications from intravascular foreign bodies and the low complication rate from percutaneous retrieval, we recommend extraction of the foreign body even if it is asymptomatic in the chronic setting (> 24 hr)

  8. Diagnosis and treatment of disseminated intravascular coagulation.

    PubMed

    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.

  9. A Simple Technique for Visualizing Ultrasound Fields Without Schlieren Optics.

    PubMed

    Kudo, Nobuki

    2015-07-01

    A simple technique designed for visualization of ultrasound fields without Schlieren optics is introduced. An optical system of direct shadowgraphy with diverging light, which consists of a point light source and a shadow screen, constituted the basic system, but the screen was replaced by focusing optics: a camera that makes a virtual screen at its focus plane. The proposed technique visualizes displacement of light deflected by ultrasound, and the use of focusing optics enables flexible settings of the virtual screen position and optical magnification. Insufficient sensitivity of shadowgraphy was overcome by elimination of non-deflecting light using image subtraction of shadowgrams taken with and without ultrasound exposure. A 1-MHz focused transducer for ultrasound therapy and a 20-MHz miniature transducer for intravascular imaging were used for experiments, and alternate pressure change in short-pulsed ultrasound was visualized, indicating the usefulness of the proposed technique for evaluation of medical ultrasound fields.

  10. Vaginal bleeding before 20 weeks gestation due to placental abruption leading to disseminated intravascular coagulation and fetal loss after appearing to satisfy criteria for routine threatened abortion: a case report and brief review of the literature.

    PubMed

    Hodgson, Danner T; Lotfipour, Shahram; Fox, J Christian

    2007-05-01

    We present a case of placental abruption with concomitant disseminated intravascular coagulation in a woman who presented with vaginal bleeding. A 32-year-old pregnant woman at 17 and 4/7 weeks gestation with a 1-month history of intermittent abdominal pain presented to our Emergency Department (ED) with 1 h of vaginal bleeding. Upon initial history, the patient reported that she was diagnosed with "blood behind the placenta" the day before and was discharged on pelvic precautions. An ED ultrasound confirmed the sub-amniotic hematoma with placental hematoma and a viable intrauterine fetus. A low fibrinogen level was suggested for disseminated intravascular coagulation and increasing hemorrhage necessitated dilation and evacuation and multiple units of blood products on an emergent basis. Only a few cases have been described in the literature demonstrating disseminated intravascular coagulation in patients at fewer than 20 weeks gestation with routine ultrasound findings of live intrauterine pregnancy and subchorionic hemorrhage. PMID:17499692

  11. CMUT-based Volumetric Ultrasonic Imaging Array Design for Forward Looking ICE and IVUS Applications

    PubMed Central

    Zahorian, Jaime; Xu, Toby; Rashid, Muhammad W.; Satir, Sarp; Gurun, Gokce; Karaman, Mustafa; Hasler, Jennifer; Degertekin, F. Levent

    2014-01-01

    Designing a mechanically flexible catheter based volumetric ultrasonic imaging device for intravascular and intracardiac imaging is challenging due to small transducer area and limited number of cables. With a few parallel channels, synthetic phased array processing is necessary to acquire data from a large number of transducer elements. This increases the data collection time and hence reduces frame rate and causes artifacts due to tissue-transducer motion. Some of these drawbacks can be resolved by different array designs offered by CMUT-on-CMOS approach. We recently implemented a 2.1-mm diameter single chip 10 MHz dual ring CMUT-on-CMOS array for forward looking ICE with 64-transmit and 56-receive elements along with associated electronics. These volumetric arrays have the small element size required by high operating frequencies and achieve sub mm resolution, but the system would be susceptible to motion artifacts. To enable real time imaging with high SNR, we designed novel arrays consisting of multiple defocused annular rings for transmit aperture and a single ring receive array. The annular transmit rings are utilized to act as a high power element by focusing to a virtual ring shaped line behind the aperture. In this case, image reconstruction is performed by only receive beamforming, reducing total required firing steps from 896 to 14 with a trade-off in image resolution. The SNR of system is improved more than 5 dB for the same frequency and frame rate as compared to the dual ring array, which can be utilized to achieve the same resolution by increasing the operating frequency. PMID:23366605

  12. Hypothesis: Disseminated Intravascular Inflammation as the Inflammatory Counterpart to Disseminated Intravascular Coagulation

    NASA Astrophysics Data System (ADS)

    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.

  13. Disseminated intravascular coagulation in meningococcal sepsis. Case 7.

    PubMed

    Zeerleder, S; Zürcher Zenklusen, R; Hack, C E; Wuillemin, W A

    2003-08-01

    We report on a man (age: 49 years), who died from severe meningococcal sepsis with disseminated intravascular coagulation (DIC), multiple organ dysfunction syndrome and extended skin necrosis. We discuss in detail the pathophysiology of the activation of coagulation and fibrinolysis during sepsis. The article discusses new therapeutic concepts in the treatment of disseminated intravascular coagulation in meningococcal sepsis, too.

  14. Intravascular imaging with a storage phosphor detector

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Petrek, Peter; Matthews, Kenneth L., II; Fritz, Shannon G.; Bujenovic, L. Steven; Xu, Tong

    2010-05-01

    The aim of this study is to develop and test an intravascular positron imaging system based on a storage phosphor detector for imaging and detecting vulnerable plaques of human coronary arteries. The radiotracer F18-FDG accumulates in vulnerable plaques with inflammation of the overlying cap. The vulnerable plaques can, therefore, be imaged by recording positrons emitted from F18-FDG with a detector inserted into the artery. A prototype intravascular detector was constructed based on storage phosphor. The detector uses a flexible storage phosphor tube with 55 mm length, 2 mm diameter and 0.28 mm wall thickness. The intravascular detector is guided into the vessel using x-ray fluoroscopy and the accumulated x-ray signal must be erased prior to positron imaging. For this purpose, a light diffuser, 0.9 mm in diameter and 55 mm in length, was inserted into the detector tube. The light diffuser was connected to a laser source through a 2 m long optical fiber. The diffuser redirected the 0.38 W laser light to the inner surface of the phosphor detector to erase it. A heart phantom with 300 cm3 volume and three coronary arteries with 3.2 mm diameter and with several plaques was constructed. FDG solution with 0.5 µCi cm-3 activity concentration was filled in the heart and coronary arteries. The detector was inserted in a coronary artery and the signal from the plaques and surrounding background activity was recorded for 2 min. Then the phosphor detector was extracted and read out using a storage phosphor reader. The light diffuser erased the signal resulting from fluoroscopic exposure to level below that encountered during positron imaging. Vulnerable plaques with area activities higher than 1.2 nCi mm-2 were visualized by the detector. This activity is a factor of 10-20 lower than that expected in human vulnerable plaques. The detector was able to image the internal surface of the coronary vessels with 50 mm length and 360° circumference. Spatial resolution was 0

  15. Advances in Molecular Imaging with Ultrasound

    PubMed Central

    Gessner, Ryan; Dayton, Paul A.

    2010-01-01

    Ultrasound imaging has long demonstrated utility in the study and measurement of anatomic features and noninvasive observation of blood flow. Within the last decade, advances in molecular biology and contrast agents have allowed researchers to use ultrasound to detect changes in the expression of molecular markers on the vascular endothelium and other intravascular targets. This new technology, referred to as ultrasonic molecular imaging, is still in its infancy. However, in preclinical studies, ultrasonic molecular imaging has shown promise in assessing angiogenesis, inflammation, and thrombus. In this review, we discuss recent advances in microbubble-type contrast agent development, ultrasound technology, and signal processing strategies that have the potential to substantially improve the capabilities and utility of ultrasonic molecular imaging. PMID:20487678

  16. Thyroid ultrasound

    PubMed Central

    Chaudhary, Vikas; Bano, Shahina

    2013-01-01

    Thyroid ultrasonography has established itself as a popular and useful tool in the evaluation and management of thyroid disorders. Advanced ultrasound techniques in thyroid imaging have not only fascinated the radiologists but also attracted the surgeons and endocrinologists who are using these techniques in their daily clinical and operative practice. This review provides an overview of indications for ultrasound in various thyroid diseases, describes characteristic ultrasound findings in these diseases, and illustrates major diagnostic pitfalls of thyroid ultrasound. PMID:23776892

  17. Protection against high intravascular pressure in giraffe legs.

    PubMed

    Petersen, Karin K; Hørlyck, Arne; Ostergaard, Kristine H; Andresen, Joergen; Broegger, Torbjoern; Skovgaard, Nini; Telinius, Niklas; Laher, Ismael; Bertelsen, Mads F; Grøndahl, Carsten; Smerup, Morten; Secher, Niels H; Brøndum, Emil; Hasenkam, John M; Wang, Tobias; Baandrup, Ulrik; Aalkjaer, Christian

    2013-11-01

    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 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 the artery. Histology of the isolated median artery confirmed dense sympathetic innervation at the narrowing. Structure and contractility of small arteries from muscular beds in the leg and neck were compared. The arteries from the legs demonstrated an increased media thickness-to-lumen diameter ratio, increased media volume, and increased numbers of smooth muscle cells per segment length and furthermore, they contracted more strongly than arteries from the neck (500 ± 49 vs. 318 ± 43 mmHg; n = 6 legs and neck, respectively). Finally, the transient increase in interstitial fluid pressure following injection of saline was 5.5 ± 1.7 times larger (n = 8) in the leg than in the neck. We conclude that 1) tissue compliance in the legs is low; 2) large arteries of the legs function as resistance arteries; and 3) structural adaptation of small muscle arteries allows them to develop an extraordinary tension. All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure.

  18. Protection against high intravascular pressure in giraffe legs.

    PubMed

    Petersen, Karin K; Hørlyck, Arne; Ostergaard, Kristine H; Andresen, Joergen; Broegger, Torbjoern; Skovgaard, Nini; Telinius, Niklas; Laher, Ismael; Bertelsen, Mads F; Grøndahl, Carsten; Smerup, Morten; Secher, Niels H; Brøndum, Emil; Hasenkam, John M; Wang, Tobias; Baandrup, Ulrik; Aalkjaer, Christian

    2013-11-01

    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 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 the artery. Histology of the isolated median artery confirmed dense sympathetic innervation at the narrowing. Structure and contractility of small arteries from muscular beds in the leg and neck were compared. The arteries from the legs demonstrated an increased media thickness-to-lumen diameter ratio, increased media volume, and increased numbers of smooth muscle cells per segment length and furthermore, they contracted more strongly than arteries from the neck (500 ± 49 vs. 318 ± 43 mmHg; n = 6 legs and neck, respectively). Finally, the transient increase in interstitial fluid pressure following injection of saline was 5.5 ± 1.7 times larger (n = 8) in the leg than in the neck. We conclude that 1) tissue compliance in the legs is low; 2) large arteries of the legs function as resistance arteries; and 3) structural adaptation of small muscle arteries allows them to develop an extraordinary tension. All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure. PMID:24005251

  19. Pulsed liquid microjet for intravascular injection

    NASA Astrophysics Data System (ADS)

    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.

  20. Intravascular behavior of a perfluorochemical emulsion.

    PubMed

    Tsuda, Y; Yamanouchi, K; Okamoto, H; Yokoyama, K; Heldebrant, C

    1990-03-01

    The purpose of this study was to clarify the reason why two similar perfluorochemical (PFC) emulsions, namely a mixed PFC (perfluorodecalin: FDC and perfluorotripropylamine: FTPA) and an FDC emulsion, resulted in a very different survival time for the exchange-transfused rats. Supposing that some difference in the intravascular behavior of both emulsions would account for such a difference in efficacy, experiments on behavior of PFC emulsions were carried out focusing on the particle size. It was reconfirmed that larger PFC particles were eliminated from the blood stream much more rapidly than smaller particles with three FMIQ (perfluoro-N-methyldecahydroisoquinoline) emulsions. After the FDC + FTPA emulsion or the FDC emulsion were injected into rabbits, PFC particles in the blood tended to decrease in size. When each of the collected blood samples was incubated at 37 degrees C for 24 h, the FDC emulsion enlarged in size markedly, but the FDC + FTPA emulsion showed no change. The retention of PFC particles appeared to depend on the emulsion stability rather than simply on the emulsifying agent alone. These data showed that some differences were observed in intravascular persistence of the FDC + FTPA emulsion and the FDC emulsion, and suggested that the efficacy of PFC emulsions would reflect their behavior in the circulation. PMID:2374085

  1. [Optical coherence tomography of coronary arteries--a novel intravascular imaging modality].

    PubMed

    Mrevlje, B; Legutko, J; Jąkała, J; Noč, M; Dudek, D; Birkemeyer, R; Aboukoura, M; Nienaber, C

    2014-09-01

    Optical coherence tomography (OCT) is the latest intravascular imaging modality for the investigation of coronary arteries. It can be used in patients with stable coronary artery disease as well as in patients with acute coronary syndrome. Its almost microscope-like resolution of 10-20 μm (10-times greater than intravascular ultrasound) gives us the most detailed insight into the coronary artery wall in vivo so far.Optical coherence tomography can be used for accurate qualitative and quantitative assessment of stenoses in stable coronary artery disease and accurate guidance of percutaneous coronary interventions as well as accurate postprocedural control. In patients with acute coronary syndrome it can be used for the detection of culprit of the culprit lesion (vulnerable plaque) which allows the operator to cover not only angiographically tightest stenosis (angiographic culprit lesion, caused in most cases by thrombus only) but most importantly the vulnerable plaque, which led to the acute event, as well. Furthermore, optical coherence tomography allows accurate assessment of thrombotic burden, stent apposition/malapposition, edge dissections and tissue prolaps or thrombus protrusions throught stent struts, etc. PMID:25225864

  2. A Broadband Polyvinylidene Difluoride-Based Hydrophone with Integrated Readout Circuit for Intravascular Photoacoustic Imaging.

    PubMed

    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.

  3. A Broadband Polyvinylidene Difluoride-Based Hydrophone with Integrated Readout Circuit for Intravascular Photoacoustic Imaging.

    PubMed

    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. PMID:26856788

  4. Dual-frequency ultrasound for detecting and sizing bubbles.

    PubMed

    Buckey, Jay C; Knaus, Darin A; Alvarenga, Donna L; Kenton, Marc A; Magari, Patrick J

    2005-01-01

    ISS construction and Mars exploration require extensive extravehicular activity (EVA), exposing crewmembers to increased decompression sickness risk. Improved bubble detection technologies could help increase EVA efficiency and safety. Creare Inc. has developed a bubble detection and sizing instrument using dual-frequency ultrasound. The device emits "pump" and "image" signals at two frequencies. The low-frequency pump signal causes an appropriately-sized bubble to resonate. When the image frequency hits a resonating bubble, mixing signals are returned at the sum and difference of the two frequencies. To test the feasibility of transcutaneous intravascular detection, intravascular bubbles in anesthetized swine were produced using agitated saline and decompression stress. Ultrasonic transducers on the chest provided the two frequencies. Mixing signals were detected transthoracically in the right atrium using both methods. A histogram of estimated bubble sizes could be constructed. Bubbles can be detected and sized transthoracically in the right atrium using dual-frequency ultrasound.

  5. Intravascular spill of hyperosmolar urea during induced midtrimester abortion.

    PubMed

    Kovasznay, B M; Burkman, R T; Atienza, M F; King, T M

    1979-01-01

    Intravascular spill of hypertonic sodium chloride and the resultant serious and occasionally fatal consquences have been reported in association with induced midtrimester abortion. This report details 3 cases of intravascular spill of hyperosmolar urea. Although urea may pose less concern, because of its ability to readily cross cell membranes and its action as an osmotic diuretic, inadvertent intravascular spill can produce symptoms that include nausea, headache, sensations of warmth, and intense uterine cramping. In addition, abnormal blood pigments may occasionally be noted in the urine. Treatment includes intravenous hydration, careful monitoring of fluid/electrolyte balance and renal function, and avoiding the use of oxytocic agents.

  6. Quinine-Induced Disseminated Intravascular Coagulation.

    PubMed

    Abed, Firas; Baniya, Ramkaji; Bachuwa, Ghassan

    2016-01-01

    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. PMID:27293443

  7. [Disseminated intravascular coagulation: clinical and biological diagnosis].

    PubMed

    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.

  8. Disseminated intravascular coagulation in burn injury.

    PubMed

    Lippi, Giuseppe; Ippolito, Luigi; Cervellin, Gianfranco

    2010-06-01

    Disseminated intravascular coagulation (DIC) is a complex and multifaceted disorder characterized by the activation of coagulation and fibrinolytic pathways, consumption of coagulation factors, and depletion of coagulation regulatory proteins. The introduction into the circulation of cellular debris characterized by strong thromboplastic activity due to tissue factor exposition or release (in or from burned tissues), which can thereby activate extrinsic pathway of coagulation system and trigger massive thrombin generation when present in sufficient concentration, represents the most plausible biological explanation to support the development of intravascular coagulation in patients with burn injury. Severe burns left untreated might also lead to an immunological and inflammatory response (activation of the complement cascade), which can amplify fibrinolysis and blood clotting. Overall, the real prevalence of DIC in patients with burns is as yet unclear. Postmortem, retrospective, and even longitudinal investigations are in fact biased by several factors, such as the objective difficulty to establish whether DIC might have occurred as a primary complication of burns or rather as a consequence of other superimposed pathologies (e.g., sepsis, multiple organ failure), the different diagnostic criteria for assessing DIC, and the heterogeneity of the patient samples studied. Nevertheless, the current scientific evidence is consistent with the hypothesis that biochemical changes suggestive for DIC (hypercoagulability, hypo- and hyperfibrinolysis) are commonplace in patients with burn trauma, and their severity increases exponentially with the severity of injury. Overt DIC seems to occur especially in critically ill burn patients or in those with severe burns (up to third degree) and large involvement of body surface area, in whom an appropriate therapy might be effective to prevent the otherwise fulminant course. Although early prophylaxis with antithrombin concentrates

  9. AUGMENTATION OF LIMB PERFUSION AND REVERSAL OF TISSUE ISCHEMIA PRODUCED BY ULTRASOUND-MEDIATED MICROBUBBLE CAVITATION

    PubMed Central

    Belcik, J. Todd; Mott, Brian H.; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J.; Ammi, Azzdine; Linden, Joel M.; Lindner, Jonathan R.

    2015-01-01

    Background Ultrasound can increase tissue blood flow in part through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation, and sought to characterize the biologic mediators. Methods and Results Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in non-ischemic mice after unilateral 10 min exposure to intermittent ultrasound alone (mechanical index [MI] 0.6 or 1.3) or ultrasound with lipid microbubbles (2×108 I.V.). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (p<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3-fold and 10-fold higher than control for MI 0.6 and 1.3, respectively; p<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase (eNOS) attenuated flow augmentation produced by ultrasound and microbubbles by 70% (p<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide (NO) production and muscle phospho-eNOS increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40–50% reduction in flow), ultrasound (MI 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control non-ischemic limb. Conclusions Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of eNOS. PMID:25834183

  10. Mechanical effects of muscle contraction increase intravascular ATP draining quiescent and active skeletal muscle in humans

    PubMed Central

    Crecelius, Anne R.; Kirby, Brett S.; Richards, Jennifer C.

    2013-01-01

    Intravascular adenosine triphosphate (ATP) evokes vasodilation and is implicated in the regulation of skeletal muscle blood flow during exercise. Mechanical stresses to erythrocytes and endothelial cells stimulate ATP release in vitro. How mechanical effects of muscle contractions contribute to increased plasma ATP during exercise is largely unexplored. We tested the hypothesis that simulated mechanical effects of muscle contractions increase [ATP]venous and ATP effluent in vivo, independent of changes in tissue metabolic demand, and further increase plasma ATP when superimposed with mild-intensity exercise. In young healthy adults, we measured forearm blood flow (FBF) (Doppler ultrasound) and plasma [ATP]v (luciferin-luciferase assay), then calculated forearm ATP effluent (FBF×[ATP]v) during rhythmic forearm compressions (RFC) via a blood pressure cuff at three graded pressures (50, 100, and 200 mmHg; Protocol 1; n = 10) and during RFC at 100 mmHg, 5% maximal voluntary contraction rhythmic handgrip exercise (RHG), and combined RFC + RHG (Protocol 2; n = 10). [ATP]v increased from rest with each cuff pressure (range 144–161 vs. 64 ± 13 nmol/l), and ATP effluent was graded with pressure. In Protocol 2, [ATP]v increased in each condition compared with rest (RFC: 123 ± 33; RHG: 51 ± 9; RFC + RHG: 96 ± 23 vs. Mean Rest: 42 ± 4 nmol/l; P < 0.05), and ATP effluent was greatest with RFC + RHG (RFC: 5.3 ± 1.4; RHG: 5.3 ± 1.1; RFC + RHG: 11.6 ± 2.7 vs. Mean Rest: 1.2 ± 0.1 nmol/min; P < 0.05). We conclude that the mechanical effects of muscle contraction can 1) independently elevate intravascular ATP draining quiescent skeletal muscle without changes in local metabolism and 2) further augment intravascular ATP during mild exercise associated with increases in metabolism and local deoxygenation; therefore, it is likely one stimulus for increasing intravascular ATP during exercise in humans. PMID:23429876

  11. 21 CFR 882.5150 - Intravascular occluding catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Class III (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or a... intravascular occluding catheter shall have an approved PMA or a declared completed PDP in effect before...

  12. 21 CFR 882.5150 - Intravascular occluding catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Class III (premarket approval). (c) Date PMA or notice of completion of a PDP is required. A PMA or a... intravascular occluding catheter shall have an approved PMA or a declared completed PDP in effect before...

  13. Intravascular laser therapy in different forms of lung diseases

    NASA Astrophysics Data System (ADS)

    Kirillov, M. N.; Reshetnikov, V. A.; Kazhekin, O. A.; Shepelenko, A. F.

    1993-06-01

    The potentions of laser intravascular therapy in elimination of pyogenic and inflammatory intoxication in cases of acute pneumonia, pyo-destructive diseases (including posttraumatic diseases) of the lungs are studied clinically.

  14. Ultrasound physics.

    PubMed

    Shriki, Jesse

    2014-01-01

    Bedside ultrasound has become an important modality for obtaining critical information in the acute care of patients. It is important to understand the physics of ultrasound in order to perform and interpret images at the bedside. The physics of both continuous wave and pulsed wave sound underlies diagnostic ultrasound. The instrumentation, including transducers and image processing, is important in the acquisition of appropriate sonographic images. Understanding how these concepts interplay with each other enables practitioners to obtain the best possible images.

  15. Collagen and chondrocyte concentrations control ultrasound scattering in agarose scaffolds.

    PubMed

    Inkinen, S; Liukkonen, J; Ylärinne, J H; Puhakka, P H; Lammi, M J; Virén, T; Jurvelin, J S; Töyräs, J

    2014-09-01

    Ultrasound imaging has been proposed for diagnostics of osteoarthritis and cartilage injuries in vivo. However, the specific contribution of chondrocytes and collagen to ultrasound scattering in articular cartilage has not been systematically studied. We investigated the role of these tissue structures by measuring ultrasound scattering in agarose scaffolds with varying collagen and chondrocyte concentrations. Ultrasound catheters with center frequencies of 9 MHz (7.1-11.0 MHz, -6 dB) and 40 MHz (30.1-45.3 MHz, -6 dB) were applied using an intravascular ultrasound device. Ultrasound backscattering quantified in a region of interest starting right below sample surface differed significantly (p < 0.05) with the concentrations of collagen and chondrocytes. An ultrasound frequency of 40 MHz, as compared with 9 MHz, was more sensitive to variations in collagen and chondrocyte concentrations. The present findings may improve diagnostic interpretation of arthroscopic ultrasound imaging and provide information necessary for development of models describing ultrasound propagation within cartilage. PMID:24972499

  16. Microbubbles in Ultrasound-Triggered Drug and Gene Delivery

    PubMed Central

    Hernot, Sophie; Klibanov, Alexander L.

    2008-01-01

    Ultrasound contrast agents, in the form of gas-filled microbubbles, are becoming popular in perfusion monitoring; they are employed as molecular imaging agents. Microbubbles are manufactured from biocompatible materials, they can be injected intravenously, and some are approved for clinical use. Microbubbles can be destroyed by ultrasound irradiation. This destruction phenomenon can be applied to targeted drug delivery and enhancement of drug action. The ultrasonic field can be focused at the target tissues and organs; thus, selectivity of the treatment can be improved, reducing undesirable side effects. Microbubbles enhance ultrasound energy deposition in the tissues and serve as cavitation nuclei, increasing intracellular drug delivery. DNA delivery and successful tissue transfection is observed in the areas of the body where ultrasound is applied after intravascular administration of microbubbles and plasmid DNA. Accelerated blood clot dissolution in the areas of insonation by cooperative action of thrombolytic agents and microbubbles is demonstrated in several clinical trials. PMID:18486268

  17. Intravascular probe for detection of vulnerable plaque

    NASA Astrophysics Data System (ADS)

    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

  18. Immunological characterization of pulmonary intravascular macrophages

    NASA Technical Reports Server (NTRS)

    Chitko-McKown, C. G.; Reddy, D. N.; Chapes, S. K.; McKown, R. D.; Blecha, F.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    Pulmonary intravascular macrophages (PIMs) are lung macrophages found apposed to the endothelium of pulmonary capillaries. In many species, they are responsible for the clearance of blood-borne particulates and pathogens; however, little else is known about their roles as immunologic effector cells. We compared PIMs with pulmonary alveolar macrophages (PAMs) to determine the relative immunological activities of these two cell populations. Our results suggested that both populations possess similar phagocytic and bactericidal activities. In assays measuring cytotoxicity, PIMs were more cytotoxic than PAMs against virally infected target cells; however, differences between these macrophage populations were not as marked when noninfected targets were used. LPS-stimulated PIMs produced more T-cell proliferative cytokines than PAMs, and both populations of nonstimulated macrophages produced similar amounts of the cytokines. In contrast, PAMs produced more TNF alpha and NO2- than PIMs when both populations were stimulated with LPS; however, nonstimulated PAMs and PIMs produced similar amounts of TNF alpha and NO2. These data suggest that bovine PIMs are immunologically active. Differences between the degrees of activity of PIMs and PAMs indicate that these macrophage populations may have different roles in lung surveillance.

  19. [Infection prevention and control in intravascular devices].

    PubMed

    Colombo, D; Russolillo, C

    2003-04-01

    Intravascular devices (IVD) are indispensable in the care of the critical patient; even so, their use can be complicated by infection, which is generally associated with longer hospital stay and ensuing higher hospital costs. It is therefore imperative that guidelines are applied that constitute a basis of information upon which the individual facility can develop its own strategy. The strategy can be outlined under the following points: a) staff training, b) surveillance of IVD-associated infections, c) hand washing, d) barrier measures during catheter introduction and management, e) insertion site management and medication systems for the insertion site, f) choice and replacement of the IVD, g) replacement of intravenous administration devices and liquids, h) antimicrobial prophylaxis. In the management of central venous catheters (CVC), recommendations call for: 1) the use of a single lumen CVC, unless multiple accesses are needed; 2) the peripheral placement of CVCs, both in the use of tunneled catheters and/or implantable vascular devices in patients over 4 years of age in which long-term vascular access (> 30 days) is planned; 3) the use of completely implantable devices in pediatric patients less than 4 years of age requiring long-term vascular access; 4) the use of the subclavian artery as the site of CVC insertion unless clinically contraindicated (e.g. coagulopathy, anatomic alterations); 5) the application of barrier precautions during CVC introduction and in the management of the catheter and the insertion site. PMID:12766724

  20. Laboratory testing in disseminated intravascular coagulation.

    PubMed

    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.

  1. Intravascular Neural Interface with Nanowire Electrode

    PubMed Central

    Watanabe, Hirobumi; Takahashi, Hirokazu; Nakao, Masayuki; Walton, Kerry; Llinás, Rodolfo R.

    2010-01-01

    Summary A minimally invasive electrical recording and stimulating technique capable of simultaneously monitoring the activity of a significant number (e.g., 103 to 104) of neurons is an absolute prerequisite in developing an effective brain–machine interface. Although there are many excellent methodologies for recording single or multiple neurons, there has been no methodology for accessing large numbers of cells in a behaving experimental animal or human individual. Brain vascular parenchyma is a promising candidate for addressing this problem. It has been proposed [1, 2] that a multitude of nanowire electrodes introduced into the central nervous system through the vascular system to address any brain area may be a possible solution. In this study we implement a design for such microcatheter for ex vivo experiments. Using Wollaston platinum wire, we design a submicron-scale electrode and develop a fabrication method. We then evaluate the mechanical properties of the electrode in a flow when passing through the intricacies of the capillary bed in ex vivo Xenopus laevis experiments. Furthermore, we demonstrate the feasibility of intravascular recording in the spinal cord of Xenopus laevis. PMID:21572940

  2. Endotoxin Induced Disseminated Intravascular Coagulation in Cattle

    PubMed Central

    Thomson, G. W.; McSherry, B. J.; Valli, V. E. O.

    1974-01-01

    Endotoxin administered intravenously to a group of four calves resulted in disseminated intravascular coagulation. A sublethal dose of piromen, a commercially available Pseudomonas spp endotoxin, was used. Serial measurements of total plasma fibrinogen, soluble fibrin levels, ethanol gelation tests, protamine sulfate tests, fibrinogen-fibrin-related antigen (FR-antigen) and prothrombin and thrombin times were done. Initial depression of plasma fibrinogen with a nadir of about 40% of pre-endotoxin levels at eight to 11 hours post-endotoxin (+8 to +11 hours) followed by an overcompensation to 180% at +60 to +108 hours was shown. Soluble fibrin was demonstrated in plasma from +2 to +22 hours with a peak of 100-114 mg/100 ml at +4 to +9 hours. Positive plasma ethanol gelation and protamine sulfate tests, as well as the presence of serum FR-antigen, occurred consistently following endotoxin administration. Significant increases in prothrombin times (PT) from +4 to +40 hours and in thrombin times (TT) from +4 to +16 hours were demonstrated. The peak increase of PT at +8 to +10 hours was 180%. The peak increase of TT at +6 to +9 hours was 260-290%. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4. PMID:4279765

  3. The basics of intravascular optical coherence tomography.

    PubMed

    Roleder, Tomasz; Jąkała, Jacek; Kałuża, Grzegorz L; Partyka, Łukasz; Proniewska, Klaudia; Pociask, Elżbieta; Zasada, Wojciech; Wojakowski, Wojciech; Gąsior, Zbigniew; Dudek, Dariusz

    2015-01-01

    Optical coherence tomography (OCT) has opened new horizons for intravascular coronary imaging. It utilizes near-infrared light to provide a microscopic insight into the pathology of coronary arteries in vivo. Optical coherence tomography is also capable of identifying the chemical composition of atherosclerotic plaques and detecting traits of their vulnerability. At present it is the only tool to measure the thickness of the fibrous cap covering the lipid core of the atheroma, and thus it is an exceptional modality to detect plaques that are prone to rupture (thin fibrous cap atheromas). Moreover, it facilitates distinguishing between plaque rupture and plaque erosion as a cause of acute intracoronary thrombosis. Optical coherence tomography is applied to guide angioplasties of coronary lesions and to assess outcomes of percutaneous coronary interventions broadly. It identifies stent malapposition, dissections, and thrombosis with unprecedented precision. Furthermore, OCT helps to monitor vessel healing after stenting. It evaluates the coverage of stent struts by the neointima and detects in-stent neoatherosclerosis. With so much potential, new studies are warranted to determine OCT's clinical impact. The following review presents the technical background, basics of OCT image interpretation, and practical tips for adequate OCT imaging, and outlines its established and potential clinical application.

  4. Contrast-enhanced ultrasound imaging of the vasa vasorum of carotid artery plaque

    PubMed Central

    Song, Ze-Zhou; Zhang, Yan-Ming

    2015-01-01

    The vasa vasorum of carotid artery plaque is a novel marker of accurately evaluating the vulnerability of carotid artery plaque, which was associated with symptomatic cerebrovascular and cardiovascular disease. The presence of ultrasound contrast agents in carotid artery plaque represents the presence of the vasa vasorum in carotid artery plaque because the ultrasound contrast agents are strict intravascular tracers. Therefore, contrast-enhanced ultrasound (CEUS) is a novel and safe imaging modality for evaluating the vasa vasorum in carotid artery plaque. However, there are some issues that needs to be assessed to embody fully the clinical utility of the vasa vasorum in carotid artery plaque with CEUS. PMID:26120382

  5. Ultrasound - Breast

    MedlinePlus

    ... discharge) and to characterize potential abnormalities seen on mammography or breast magnetic resonance imaging (MRI). Ultrasound imaging ... supply in breast lesions . Supplemental Breast Cancer Screening Mammography is the only screening tool for breast cancer ...

  6. Thyroid ultrasound

    MedlinePlus

    ... Performed Ultrasound is a painless method that uses sound waves to create images of the inside of the ... neck to help with the transmission of the sound waves. Next, the technician moves a wand, called a ...

  7. Abdominal Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  8. Obstetrical Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  9. [Interventional ultrasound].

    PubMed

    Blázquez Sánchez, N; Fernández Canedo, I; Valdés Vilches, L; de Troya Martín, M

    2015-11-01

    High-frequency ultrasound has become increasingly used in dermatology. This technique is accessible, non-invasive, and rapid and provides information in real time. Consequently, it has become of great diagnostic value in dermatology. However, high-frequency ultrasound also has a promising future as a complementary technique in interventional diagnostic procedures, even though its application in this field has been little studied by dermatologists. PMID:26895944

  10. Management of cancer-associated disseminated intravascular coagulation.

    PubMed

    Levi, Marcel

    2016-04-01

    Cancer may be complicated by the occurrence of disseminated intravascular coagulation (DIC). DIC is characterized by a widespread and intravascular activation of coagulation (leading to intravascular fibrin deposition) and simultaneous consumption of coagulation factors and platelets (potentially resulting in bleeding). Clinically, DIC in cancer has in general a less fulminant presentation than the types of DIC complicating sepsis and trauma. A more gradual, but also more chronic, systemic activation of coagulation can proceed subclinically. Eventually this process may lead to exhaustion of platelets and coagulation factors and bleeding (for example at the site of the tumor) may be the first clinical symptom indicating the presence of DIC. In some cases, the clinical presentation of DIC in cancer may be reminiscent of thrombotic microangiopathies, which is understandable in view of the role of endothelium in both conditions. The therapeutic cornerstone of DIC is treatment of the underlying disorder but supportive treatment, specifically aimed at the hemostatic system may be required. PMID:27067981

  11. Trauma Ultrasound.

    PubMed

    Wongwaisayawan, Sirote; Suwannanon, Ruedeekorn; Prachanukool, Thidathit; Sricharoen, Pungkava; Saksobhavivat, Nitima; Kaewlai, Rathachai

    2015-10-01

    Ultrasound plays a pivotal role in the evaluation of acute trauma patients through the use of multi-site scanning encompassing abdominal, cardiothoracic, vascular and skeletal scans. In a high-speed polytrauma setting, because exsanguinations are the primary cause of trauma morbidity and mortality, ultrasound is used for quick and accurate detection of hemorrhages in the pericardial, pleural, and peritoneal cavities during the primary Advanced Trauma Life Support (ATLS) survey. Volume status can be assessed non-invasively with ultrasound of the inferior vena cava (IVC), which is a useful tool in the initial phase and follow-up evaluations. Pneumothorax can also be quickly detected with ultrasound. During the secondary survey and in patients sustaining low-speed or localized trauma, ultrasound can be used to help detect abdominal organ injuries. This is particularly helpful in patients in whom hemoperitoneum is not identified on an initial scan because findings of organ injuries will expedite the next test, often computed tomography (CT). Moreover, ultrasound can assist in detection of fractures easily obscured on radiography, such as rib and sternal fractures.

  12. 21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Percutaneous, implanted, long-term intravascular... and Personal Use Therapeutic Devices § 880.5970 Percutaneous, implanted, long-term intravascular catheter. (a) Identification. A percutaneous, implanted, long-term intravascular catheter is a device...

  13. Incidental Intravascular Lipoleiomyomatosis in A Hysterectomy Specimen: How To Manage?

    PubMed Central

    Aslanova, Rakhshanda; Can, Nuray; Okten, Sabri Berkem; Aslan, Mehmet Musa

    2015-01-01

    Leiomyomas are common benign tumors in female gynaecologic surgery. They are originated from smooth muscle cells of the uterus and/or sometimes of the uterine vessels. Intravascular lipoleiomyomatosis is a very rare form of leiomyomas which grow within veins and can extend up to vena cava inferior and right heart chamber with cardiac symptoms and is diagnosed by cardiovascular surgeons. We report a case of incidental intravascular lipoleiomyomatosis which was confined to the uterus being diagnosed after a total abdominal hysterectomy by pathology and its management strategy. PMID:25738043

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

    PubMed

    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.

  15. Cranial Ultrasound/Head Ultrasound

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a ...

  16. The correspondence between coronary arterial wall strain and histology in a porcine model of atherosclerosis

    NASA Astrophysics Data System (ADS)

    Liang, Yun; Zhu, Hui; Friedman, Morton H.

    2009-09-01

    Atherosclerotic plaque rupture is the leading cause of mortality in cardiovascular disease. Intravascular ultrasound (IVUS) imaging is a powerful clinical technique that provides real-time cross-sectional images of the arterial wall and atherosclerotic plaques. However, it does not provide sufficient information about the histological composition of plaques to characterize their vulnerability. Arterial wall strain measurements may provide insights into plaque composition and vulnerability, complementing the information directly available in the IVUS echogram. We have developed a method to measure the transverse arterial wall strain tensor in response to luminal pressure change, by registering IVUS images acquired at different pressures. This method has been validated by using IVUS images with simulated motion and IVUS images of a vessel phantom. In this study, we further evaluate the method by assessing the correspondence of the calculated strain distribution and the histological composition of atherosclerotic coronary arteries from Sinclair miniature pigs following 12 months of a high fat diet. The images were acquired in situ using a clinical IVUS system and under computer-controlled pressurization. After image acquisition, the artery segments were fixed for histology to identify plaque components. The strain distributions were aligned with the corresponding histological sections. The stiffness of various components of the lesion, inferred from the wall strain distribution, was consistent with the tissue composition seen in the histological cross-sections. These findings suggest that strain measurements from IVUS are promising for assessing plaque vulnerability.

  17. Incidence of intravascular penetration in transforaminal cervical epidural steroid injections.

    PubMed

    Furman, Michael B; Giovanniello, Michael T; O'Brien, Erin M

    2003-01-01

    STUDY DESIGN A prospective, observational, human, study was conducted. OBJECTIVES To evaluate the incidence of vascular penetration during fluoroscopically guided, contrast-enhanced transforaminal cervical epidural steroid injections, and to determine whether the observation of blood in the needle hub can be used to predict a vascular injection. SUMMARY OF BACKGROUND DATA Incorrectly placed intravascular cervical spinal injections result in medication flow systemically and not to the desired target. A recently published study demonstrates a high incidence of intravascular injections in transforaminal lumbosacral epidural injections. No studies so far have evaluated the incidence of vascular injections in transforaminal cervical epidural steroid injections, nor have they calculated the ability of observed blood in the needle hub to predict a vascular injection in the cervical spine.METHODS The incidence of fluoroscopically confirmed intravascular uptake of contrast was prospectively observed in 337 patients treated with cervical transforaminal epidural steroid injections. The ability of observed blood in the needle hub to predict intravascular injection was also investigated. For each subject, the injection level was chosen on the basis of the clinical scenario including history, physical examination, and review of imaging studies. Some patients had multilevel injections. Using fluoroscopic guidance, the authors placed a 25-gauge needle into the epidural space using a transforaminal approach according to accepted standard technique. Needle tip location was confirmed with biplanar imaging. The presence or absence of blood in the needle hub spontaneously ("flash") and after attempted aspiration by pulling back on the syringe's plunger was documented. Contrast then was injected under real-time fluoroscopy to determine whether the location of the needle tip was intravascular. The results were recorded in a prospective manner indicating the presence or absence of blood

  18. A Prognostic Dilemma of Basal Cell Carcinoma with Intravascular Invasion

    PubMed Central

    Niumsawatt, Vachara; Castley, Andrew

    2016-01-01

    Summary: Basal cell carcinoma is the most common malignancy; however, it very rarely metastasizes. Despite the low mortality caused by this cancer, once it spreads, it has dim prognosis. We report a case of basal cell carcinoma with rare intravascular invasion and review the literature for risk factors and management of metastasis.

  19. 21 CFR 870.3375 - Cardiovascular intravascular filter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cardiovascular intravascular filter. 870.3375 Section 870.3375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... side of the heart and the pulmonary circulation. (b) Classification. Class II. The special controls...

  20. 21 CFR 870.3375 - Cardiovascular intravascular filter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cardiovascular intravascular filter. 870.3375 Section 870.3375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... side of the heart and the pulmonary circulation. (b) Classification. Class II. The special controls...

  1. 21 CFR 870.3375 - Cardiovascular intravascular filter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cardiovascular intravascular filter. 870.3375 Section 870.3375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices §...

  2. 21 CFR 870.3375 - Cardiovascular intravascular filter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cardiovascular intravascular filter. 870.3375 Section 870.3375 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices §...

  3. Integration of multi-modality imaging for accurate 3D reconstruction of human coronary arteries in vivo

    NASA Astrophysics Data System (ADS)

    Giannoglou, George D.; Chatzizisis, Yiannis S.; Sianos, George; Tsikaderis, Dimitrios; Matakos, Antonis; Koutkias, Vassilios; Diamantopoulos, Panagiotis; Maglaveras, Nicos; Parcharidis, George E.; Louridas, George E.

    2006-12-01

    In conventional intravascular ultrasound (IVUS)-based three-dimensional (3D) reconstruction of human coronary arteries, IVUS images are arranged linearly generating a straight vessel volume. However, with this approach real vessel curvature is neglected. To overcome this limitation an imaging method was developed based on integration of IVUS and biplane coronary angiography (BCA). In 17 coronary arteries from nine patients, IVUS and BCA were performed. From each angiographic projection, a single end-diastolic frame was selected and in each frame the IVUS catheter was interactively detected for the extraction of 3D catheter path. Ultrasound data was obtained with a sheath-based catheter and recorded on S-VHS videotape. S-VHS data was digitized and lumen and media-adventitia contours were semi-automatically detected in end-diastolic IVUS images. Each pair of contours was aligned perpendicularly to the catheter path and rotated in space by implementing an algorithm based on Frenet-Serret rules. Lumen and media-adventitia contours were interpolated through generation of intermediate contours creating a real 3D lumen and vessel volume, respectively. The absolute orientation of the reconstructed lumen was determined by back-projecting it onto both angiographic planes and comparing the projected lumen with the actual angiographic lumen. In conclusion, our method is capable of performing rapid and accurate 3D reconstruction of human coronary arteries in vivo. This technique can be utilized for reliable plaque morphometric, geometrical and hemodynamic analyses.

  4. Ultrasound Annual, 1984

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1984-01-01

    The 1984 edition of Ultrasound Annual explores new applications of ultrasound in speech and swallowing and offers guidelines on the use of ultrasound and nuclear medicine in thyroid and biliary tract disease. Other areas covered include Doppler sonography of the abdomen, intraoperative abdominal ultrasound, sonography of the placenta, ultrasound of the neonatal head and abdomen, and sonographic echo patterns created by fat.

  5. Characterization of coronary atherosclerosis by intravascular imaging modalities.

    PubMed

    Honda, Satoshi; Kataoka, Yu; Kanaya, Tomoaki; Noguchi, Teruo; Ogawa, Hisao; Yasuda, Satoshi

    2016-08-01

    Coronary artery disease (CAD) is highly prevalent in Western countries and is associated with morbidity, mortality, and a significant economic burden. Despite the development of anti-atherosclerotic medical therapies, many patients still continue to suffer from coronary events. This residual risk indicates the need for better risk stratification and additional therapies to achieve more reductions in cardiovascular risk. Recent advances in imaging modalities have contributed to visualizing atherosclerotic plaques and defining lesion characteristics in vivo. This innovation has been applied to refining revascularization procedure, assessment of anti-atherosclerotic drug efficacy and the detection of high-risk plaques. As such, intravascular imaging plays an important role in further improvement of cardiovascular outcomes in patients with CAD. The current article reviews available intravascular imaging modalities with regard to its method, advantage and disadvantage. PMID:27500094

  6. Disseminated intravascular coagulation in term and preterm neonates.

    PubMed

    Veldman, Alex; Fischer, Doris; Nold, Marcel F; Wong, Flora Y

    2010-06-01

    Among critically ill patients, the risk of developing disseminated intravascular coagulation (DIC) is probably highest in neonates. Low plasma reserves in pro- and anticoagulant coagulation factors, intravascular volume contraction after birth, and a high incidence of hypoxia and sepsis in critically ill newborns rapidly lead to a decompensation of the coagulation system in this population. Global coagulation tests and single-factor plasma levels have to be interpreted in the context of age-corrected normal ranges. Platelet consumption and reduced protein C plasma levels have diagnostic value; the latter also has prognostic potential in neonates with DIC and sepsis. Therapeutic success relies heavily on reversal of the underlying condition. Some coagulation-specific therapies have been explored in small studies and case series with varying success and sometimes conflicting results. Therefore, larger controlled trials in this common and serious condition are urgently needed.

  7. Characterization of coronary atherosclerosis by intravascular imaging modalities

    PubMed Central

    Honda, Satoshi; Kanaya, Tomoaki; Noguchi, Teruo; Ogawa, Hisao; Yasuda, Satoshi

    2016-01-01

    Coronary artery disease (CAD) is highly prevalent in Western countries and is associated with morbidity, mortality, and a significant economic burden. Despite the development of anti-atherosclerotic medical therapies, many patients still continue to suffer from coronary events. This residual risk indicates the need for better risk stratification and additional therapies to achieve more reductions in cardiovascular risk. Recent advances in imaging modalities have contributed to visualizing atherosclerotic plaques and defining lesion characteristics in vivo. This innovation has been applied to refining revascularization procedure, assessment of anti-atherosclerotic drug efficacy and the detection of high-risk plaques. As such, intravascular imaging plays an important role in further improvement of cardiovascular outcomes in patients with CAD. The current article reviews available intravascular imaging modalities with regard to its method, advantage and disadvantage. PMID:27500094

  8. Transponder system for non-invasive measurement of intravascular pressure.

    PubMed

    Schnakenberg, U; Krüger, C; Pfeffer, J G; Mokwa, W; von Bögel, G; Günther, R; Schmitz-Rode, Th

    2002-01-01

    Monitoring of blood pressure and pulse rate offers diagnostical and therapeutical opportunities in hypertension disease and arrhythmia, respectively. This paper presents an intravascular pressure monitoring system consisting of an implantable silicone capsule, which can be placed in an arterial system via a catheter. The capsule contains a pressure sensor and signal conditioning circuits for wireless data and energy transfer using 6.78 MHz transponder technology.

  9. Disseminated intravascular coagulation and hepatocellular necrosis due to clove oil.

    PubMed

    Brown, S A; Biggerstaff, J; Savidge, G F

    1992-10-01

    We describe the case of a 2-year-old child who suffered from disseminated intravascular coagulation (DIC) and hepatocellular necrosis, following ingestion of clove oil. The patient was treated with heparin and fresh frozen plasma, and, following specific haemostasis assays, with appropriate coagulation factor and inhibitor concentrates. The case demonstrates how this approach can be successfully used in the management of DIC with coexisting liver failure. PMID:1450336

  10. Silent intravascular lymphoma initially manifesting as a unilateral adrenal incidentaloma.

    PubMed

    Takahashi, Yoshiko; Iida, Keiji; Hino, Yasuhisa; Ohara, Takeshi; Kurahashi, Toshifumi; Tashiro, Takashi; Chihara, Kazuo

    2012-01-01

    Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of malignant lymphoma. Although the involvement of adrenal glands in IVLBCL is often observed, primary adrenal IVLBCL is rare. Most reported cases of adrenal IVLBCL showed bilateral lesions resulting in rapidly progressive adrenal failure and poor prognosis. Here, we report a case of slowly progressive primary adrenal IVLBCL manifesting initially with unilateral adrenal incidentaloma. This case is a silent IVLBCL and shows that the enlargement of both adrenal glands can be followed.

  11. Optical device for intravascular low-power laser illumination

    NASA Astrophysics Data System (ADS)

    Grobelny, Andrzej; Palasz, Zbigniew; Beres-Pawlik, Elzbieta M.; Abramski, Krzysztof M.; Derkacz, Arkadiusz; Bialy, Dariusz; Protasiewicz, Marcin

    2003-04-01

    The treatment method presented in this paper is an adjunct to coronary angioplasty. It consists in irradiating a previously dilated artery with laser light which stimulates endothelium proliferation and reduces local inflammation. The influence of 808 nm laser light on the endothelium was studied in vitro. Because of the location of atherosclerotic plaques, illumination of the endothelium poses a problem. To overcome it, we have designed and built a laser set-up for homogeneous intravascular illumination in vivo.

  12. Venous Ultrasound (Extremities)

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  13. Vascular wall stress during intravascular optical coherence tomography imaging

    NASA Astrophysics Data System (ADS)

    Sun, Cuiru; Yang, Victor

    2015-03-01

    Biomechanical properties of arterial wall is crucial for understanding the changes in the cardiovascular system. Catheters are used during intravascular optical coherence tomography (IVOCT) imaging. The presence of a catheter alters the flow field, pressure distribution and frictional resistance to flow in an artery. In this paper, we first study the transmural stress distribution of the catheterized vessel. COMSOL (COMSOL 4.4) was used to simulate the blood flow induced deformation in a catheterized vessel. Blood is modeled as an incompressible Newtonian fluid. Stress distribution from an three-layer vascular model with an eccentric catheter are simulated, which provides a general idea about the distribution of the displacement and the stress. Optical coherence elastography techniques were then applied to porcine carotid artery samples to look at the deformation status of the vascular wall during saline or water injection. Preliminary simulation results show nonuniform stress distribution in the circumferential direction of the eccentrically catheterized vascular model. Three strain rate methods were tested for intravascular OCE application. The tissue Doppler method has the potential to be further developed to image the vascular wall biomechnical properties in vivo. Although results in this study are not validated quantitatively, the experiments and methods may be valuable for intravascular OCE studies, which may provide important information for cardiovascular disease prevention, diagnosis and treatment.

  14. High intensity focused ultrasound sonothrombolysis: the use of perfluorocarbon droplets to achieve clot lysis at reduced acoustic powers

    PubMed Central

    Pajek, Daniel; Burgess, Alison; Huang, Yuexi; Hynynen, Kullervo

    2014-01-01

    The purpose of this study was to evaluate use of intravascular perfluorocarbon (PFC) droplets to reduce the sonication powers required to achieve clot lysis using high intensity focused ultrasound (HIFU). HIFU with droplets was initially applied to blood clots in an in vitro flow apparatus and inertial cavitation thresholds were determined. An embolic model for ischemic stroke was used to demonstrate the feasibility of this technique in vivo. Recanalization with intravascular droplets was achieved in vivo at 24±5% of the sonication power without droplets. Rabbits receiving 1 ms pulsed sonication during continuous intravascular droplet infusion recanalized in 71% of cases (p=0.041 vs controls). Preliminary experiments showed that damage was contained to the ultrasonic focus, suggesting that safe treatments would be possible with a more tightly focused hemispherical array that allows the whole focus to be placed inside of the main arteries in the human brain. PMID:25023095

  15. Disseminated intravascular large-cell lymphoma with initial presentation mimicking Guillain-Barré syndrome.

    PubMed

    Jiang, Qin Li; Pytel, Peter; Rowin, Julie

    2010-07-01

    We report a patient with intravascular large B-cell lymphoma who initially presented with acute ascending weakness and sensory changes. Electrodiagnostic testing and cerebral spinal fluid (CSF) studies were initially suggestive of a demyelinating polyneuropathy. Further clinical evaluation and testing were consistent with mononeuropathy multiplex. Autopsy revealed disseminated intravascular large-cell lymphoma. Intravascular large-cell lymphoma should be considered in the differential diagnosis of a rapidly evolving neuropathy associated with other organ involvement.

  16. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... eye is numbed with medicine (anesthetic drops). The ultrasound wand (transducer) is placed against the front surface ...

  17. Ultrasound annual, 1986

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1986-01-01

    This book provides an analyses of developments in the field of diagnostic ultrasound. Endoscopic ultrasound and ultrasound-guided aspiration of ovarian follicles for in vitro fertilization are addressed. The use of Doppler ultrasound to measure blood flow in obstetrics is also examined.

  18. Low-Power 2-MHz Pulsed-Wave Transcranial Ultrasound Reduces Ischemic Brain Damage in Rats.

    PubMed

    Alexandrov, Andrei V; Barlinn, Kristian; Strong, Roger; Alexandrov, Anne W; Aronowski, Jaroslaw

    2011-09-01

    It is largely unknown whether prolonged insonation with ultrasound impacts the ischemic brain tissue by itself. Our goal was to evaluate safety and the effect of high-frequency ultrasound on infarct volume in rats. Thirty-two Long-Evans rats with permanent middle cerebral and carotid artery occlusions received either 2-MHz ultrasound at two levels of insonation power (128 or 10 mW) or no ultrasound (controls). We measured cerebral hemorrhage, indirect and direct infarct volume as well as edema volume at 24 h. No cerebral hemorrhages were detected in all animals. Exposure to low-power (10 mW) ultrasound resulted in a significantly decreased indirect infarct volume (p = 0.0039), direct infarct volume (p = 0.0031), and brain edema volume (p = 0.01) compared with controls. High-power (128 mW) ultrasound had no significant effects. An additional experiment with India ink showed a greater intravascular penetration of dye into ischemic tissues exposed to low-power ultrasound. Insonation with high-frequency, low-power ultrasound reduces ischemic brain damage in rat. Its effect on edema reduction and possible promotion of microcirculation could be used to facilitate drug and nutrient delivery to ischemic areas.

  19. Comparison of plaque characteristics in narrowings with ST-elevation myocardial infarction (STEMI), non-STEMI/unstable angina pectoris and stable coronary artery disease (from the ADAPT-DES IVUS Substudy).

    PubMed

    Dong, Liang; Mintz, Gary S; Witzenbichler, Bernhard; Metzger, D Christopher; Rinaldi, Michael J; Duffy, Peter L; Weisz, Giora; Stuckey, Thomas D; Brodie, Bruce R; Yun, Kyeong Ho; Xu, Ke; Kirtane, Ajay J; Stone, Gregg W; Maehara, Akiko

    2015-04-01

    Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a prospective, multicenter registry of 8,582 consecutive stable and unstable patients who underwent percutaneous coronary intervention using a drug-eluting stent. We sought to identify key morphologic features leading to ST-segment elevation myocardial infarction (STEMI) versus non-STEMI (NSTEMI) or unstable angina pectoris (UA) versus stable coronary artery disease (CAD) presentation. In the prespecified grayscale and virtual histology (VH) substudy of ADAPT-DES, preintervention imaging identified 676 patients with a single culprit lesion. The relation between lesion morphology and clinical presentation was compared among patients with (1) STEMI, (2) NSTEMI or UA, and (3) stable CAD. Intravascular ultrasound identified more plaque rupture and VH thin-cap fibroatheroma (TCFA) in STEMI lesions compared with NSTEMI/UA or stable CAD lesions; conversely, fibroatheromas appeared more often calcified with a thick fibrous cap in stable CAD. Minimum lumen cross-sectional area (MLA) was smaller with larger plaque burden and positive remodeling in STEMI lesions. Lesions with plaque rupture versus those without plaque rupture showed higher prevalence of VH-TCFA and larger plaque burden with positive remodeling, especially in patients with STEMI. Multivariate analysis showed that in the lesions with plaque rupture, plaque burden at the MLA site was the only independent predictor for STEMI (cutoff of plaque burden = 85%) and in lesions without plaque rupture, MLA was the only independent predictor for STEMI (cutoff of MLA = 2.3 mm(2)). In conclusion, culprit lesions causing STEMI have smaller lumen areas, greater plaque burden, and more plaque rupture or VH-TCFA compared with NSTEMI/UA or stable CAD; in lesions with plaque rupture, only plaque burden predicted STEMI, and in lesions without plaque rupture, only MLA area predicted STEMI.

  20. Bothrops jararaca envenomation: Pathogenesis of hemostatic disturbances and intravascular hemolysis

    PubMed Central

    Senise, Luana V; Yamashita, Karine M

    2015-01-01

    To attain fully functional biological activity, vitamin-K dependent coagulation factors (VKDCF) are γ-carboxylated prior to secretion from liver. Warfarin impairs the γ-carboxylation, and consequently their physiological function. Bothrops jararaca snake venom (BjV) contains several activators of blood coagulation, especially procoagulant enzymes (prothrombin and factor X activators) and thrombin-like enzymes. In order to clarify the relative contribution of prothrombin and factor X activators to the hemostatic disturbances occurring during experimental B. jararaca envenomation, warfarin was used to deplete VKDCF, prior to BjV administration. Male Wistar rats were pretreated with saline (Sal) or warfarin (War) and inoculated subsequently with BjV or saline, thus forming four groups: Sal + Sal (negative control), Sal + BjV (positive control), War + Sal (warfarinization control), and War + BjV. Three hours after inoculation, prothrombin and factor X levels fell 40% and 50%, respectively; levels of both factors decreased more than 97% in the War + Sal and War + BjV groups. Platelet counts dropped 93% and 76% in Sal + BjV and War + BjV, respectively, and plasma fibrinogen levels decreased 86% exclusively in Sal + BjV. After 6 and 24 h, platelet counts and fibrinogen levels increased progressively. A dramatic augmentation in plasma hemoglobin levels and the presence of schizocytes and microcytes in the Sal + BjV group indicated the development of intravascular hemolysis, which was prevented by warfarin pretreatment. Our findings show that intravascular thrombin generation has the foremost role in the pathogenesis of coagulopathy and intravascular hemolysis, but not in the development of thrombocytopenia, in B. jararaca envenomation in rats; in addition, fibrinogenases (metalloproteinases) may contribute to coagulopathy more than thrombin-like enzymes. PMID:26080462

  1. Ultrasound in Space Medicine

    NASA Technical Reports Server (NTRS)

    Dulchavsky, Scott A.; Sargsyan, A.E.

    2009-01-01

    This slide presentation reviews the use of ultrasound as a diagnostic tool in microgravity environments. The goals of research in ultrasound usage in space environments are: (1) Determine accuracy of ultrasound in novel clinical conditions. (2) Determine optimal training methodologies, (3) Determine microgravity associated changes and (4) Develop intuitive ultrasound catalog to enhance autonomous medical care. Also uses of Ultrasound technology in terrestrial applications are reviewed.

  2. 21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...: “Guidance on Premarket Notification Submission for Short-Term and Long-Term Intravascular Catheters.” ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Percutaneous, implanted, long-term intravascular... and Personal Use Therapeutic Devices § 880.5970 Percutaneous, implanted, long-term...

  3. 21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...: “Guidance on Premarket Notification Submission for Short-Term and Long-Term Intravascular Catheters.” ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Percutaneous, implanted, long-term intravascular... and Personal Use Therapeutic Devices § 880.5970 Percutaneous, implanted, long-term...

  4. 21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...: “Guidance on Premarket Notification Submission for Short-Term and Long-Term Intravascular Catheters.” ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Percutaneous, implanted, long-term intravascular... and Personal Use Therapeutic Devices § 880.5970 Percutaneous, implanted, long-term...

  5. [Incidence of biological intravascular coagulation in legal induced abortions].

    PubMed

    Boudaoud, S; Eurin, B; Drouet, L; Alhomme, P; Dreyfus, R; Serfaty, D

    1986-01-01

    A prospective study was designed to evaluate coagulation abnormalities induced by early abortion (before ten weeks of pregnancy). Fifty-two women underwent suction abortion, under diazepam-fentanyl anaesthesia with spontaneous ventilation; they were screened for coagulation parameters before and after surgery. Eight tests were carried out: prothrombin time, activated partial thromboplastin time (APTT), thrombin time platelet count, fibrinogen levels, fibrin split products, fibrin soluble complexes and euglobulin lysis time. Results were consistent with activation. Consequences were limited and one general test (APTT) was not significantly modified. Suction abortion, even performed in early pregnancy, exposed to biological disseminated intravascular coagulation with a general risk of venous thrombosis.

  6. Disseminated Intravascular Coagulation after Surgery for Facial Injury

    PubMed Central

    Tachibana, Hirohiko; Ishikawa, Shigeo; Yusa, Kazuyuki; Kitabatake, Kenichirou; Iino, Mitsuyoshi

    2016-01-01

    A case of disseminated intravascular coagulation (DIC) presenting after surgery for facial trauma associated with multiple facial bone fractures is described. With regard to the oral and maxillofacial region, DIC has been described in the literature following head trauma, infection, and metastatic disease. Until now, only 5 reports have described DIC after surgery for facial injury. DIC secondary to facial injury is thus rare. The patient in this case was young and had no medical history. Preoperative hemorrhage or postoperative septicemia may thus induce DIC. PMID:27313913

  7. Venous gas embolism - Time course of residual pulmonary intravascular bubbles

    NASA Technical Reports Server (NTRS)

    Butler, B. D.; Luehr, S.; Katz, J.

    1989-01-01

    A study was carried out to determine the time course of residual pulmonary intravascular bubbles after embolization with known amounts of venous air, using an N2O challenge technique. Attention was also given to the length of time that the venous gas emboli remained as discrete bubbles in the lungs with 100 percent oxygen ventilation. The data indicate that venous gas emboli can remain in the pulmonary vasculature as discrete bubbles for periods lasting up to 43 + or - 10.8 min in dogs ventilated with oxygen and nitrogen. With 100 percent oxygen ventilation, these values are reduced significantly to 19 + or - 2.5 min.

  8. Intravascular filarial parasites elaborate cyclooxygenase-derived eicosanoids

    PubMed Central

    1990-01-01

    The nematode parasites that cause human lymphatic filariasis survive for long periods in their vascular habitats despite continual exposure to host cells. Since prostanoids formed from arachidonic acid can modulate interactions among platelets, leukocytes, and endothelial cells, we examined whether intravascular nematode parasites can elaborate prostanoids. Microfilariae of Brugia malayi utilize exogenous and endogenous arachidonic acid to generate and release two predominant prostanoids, prostacyclin and prostaglandin E2. Filarial metabolism of host fatty acids to form these vasodilatory, antiaggregatory, and immunomodulatory eicosanoids provides a means by which these helminthic parasites may influence host immune and other cellular responses. PMID:2117642

  9. Removal of Chronic Intravascular Blood Clots using Liquid Plasma

    NASA Astrophysics Data System (ADS)

    Jung, Jae-Chul; Choi, Myeong; Koo, Il; Yu, Zengqi; Collins, George

    2011-10-01

    An electrical embolectomy device for removing chronic intravascular blood clots using liquid plasma under saline environment was demonstrated. We employed a proxy experimental blood clot model of deep vein thrombosis (DVT) and actual equine blood clot. Thermal damage to contiguous tissue and the collagen denaturing via the plasma irradiation were investigated by histological analysis using birefringence of the tissue and verified by FT-IR spectroscopic study, respectively, which showed the high removal rate up to 2 mm per minute at room temperature and small thermal damage less than 200 μm.

  10. The first recurrent intravascular papillary endothelial hyperplasia (Masson’s tumor) of the kidney

    PubMed Central

    Alkan, Erdal; Sağlıcan, Yeşim; Özkanlı, Ahmet Oğuz; Balbay, Mevlana Derya

    2016-01-01

    Intravascular papillary endothelial hyperplasia (IPEH, Masson’s Tumor) of the kidney is an unusual, benign vascular lesion. A rare case of recurrent IPEH in the kidney was presented in this article. A 50-year-old male with a diagnosis of a suspicious mass in the left kidney was referred to our center for robotic partial nephrectomy. Robotic zero ischemia partial nephrectomy was performed due to the suspicion of a renal malignancy. On the basis of the histopathological results, the patient was diagnosed as IPEH. A urinary ultrasound was performed on the 3rd postoperative month and a hyper echoic solid lesion, which was in the same localization, was detected. Due to the previous atypical pathological result, computed tomography (CT) guided fine-needle aspiration biopsy from the left renal mass was performed but malignant cytology was not confirmed with this biopsy. On follow-up CT done 6 months later, a persistent suspicious left renal mass, measuring 40 × 30 cm in size was detected with no change in its dimensions and appearance. Additionally, magnetic resonance imaging (MRI) scan revealed a bone lesion of 15 × 10 mm in the left hip, which was not present on previous MRI/CT scans. In view of the solid masses in the left kidney, and left hip on CT and MRI scan suspicious for a probably metastatic renal neoplasm, left radical nephrectomy via a left subcostal transperitoneal incision was performed. The ultimate pathological report of the patient was also supported the diagnosis of Masson’s tumor and any renal malignancy was not encountered The patient was discharged on the 4th postoperative day and has been followed up for 4 months without any problems. In this case, we discuss the clinical features, histopathological characteristics, and the management of Masson’s tumor of the kidney in the light of the current literature.

  11. The first recurrent intravascular papillary endothelial hyperplasia (Masson’s tumor) of the kidney

    PubMed Central

    Alkan, Erdal; Sağlıcan, Yeşim; Özkanlı, Ahmet Oğuz; Balbay, Mevlana Derya

    2016-01-01

    Intravascular papillary endothelial hyperplasia (IPEH, Masson’s Tumor) of the kidney is an unusual, benign vascular lesion. A rare case of recurrent IPEH in the kidney was presented in this article. A 50-year-old male with a diagnosis of a suspicious mass in the left kidney was referred to our center for robotic partial nephrectomy. Robotic zero ischemia partial nephrectomy was performed due to the suspicion of a renal malignancy. On the basis of the histopathological results, the patient was diagnosed as IPEH. A urinary ultrasound was performed on the 3rd postoperative month and a hyper echoic solid lesion, which was in the same localization, was detected. Due to the previous atypical pathological result, computed tomography (CT) guided fine-needle aspiration biopsy from the left renal mass was performed but malignant cytology was not confirmed with this biopsy. On follow-up CT done 6 months later, a persistent suspicious left renal mass, measuring 40 × 30 cm in size was detected with no change in its dimensions and appearance. Additionally, magnetic resonance imaging (MRI) scan revealed a bone lesion of 15 × 10 mm in the left hip, which was not present on previous MRI/CT scans. In view of the solid masses in the left kidney, and left hip on CT and MRI scan suspicious for a probably metastatic renal neoplasm, left radical nephrectomy via a left subcostal transperitoneal incision was performed. The ultimate pathological report of the patient was also supported the diagnosis of Masson’s tumor and any renal malignancy was not encountered The patient was discharged on the 4th postoperative day and has been followed up for 4 months without any problems. In this case, we discuss the clinical features, histopathological characteristics, and the management of Masson’s tumor of the kidney in the light of the current literature. PMID:27635297

  12. The first recurrent intravascular papillary endothelial hyperplasia (Masson's tumor) of the kidney.

    PubMed

    Alkan, Erdal; Sağlıcan, Yeşim; Özkanlı, Ahmet Oğuz; Balbay, Mevlana Derya

    2016-09-01

    Intravascular papillary endothelial hyperplasia (IPEH, Masson's Tumor) of the kidney is an unusual, benign vascular lesion. A rare case of recurrent IPEH in the kidney was presented in this article. A 50-year-old male with a diagnosis of a suspicious mass in the left kidney was referred to our center for robotic partial nephrectomy. Robotic zero ischemia partial nephrectomy was performed due to the suspicion of a renal malignancy. On the basis of the histopathological results, the patient was diagnosed as IPEH. A urinary ultrasound was performed on the 3(rd) postoperative month and a hyper echoic solid lesion, which was in the same localization, was detected. Due to the previous atypical pathological result, computed tomography (CT) guided fine-needle aspiration biopsy from the left renal mass was performed but malignant cytology was not confirmed with this biopsy. On follow-up CT done 6 months later, a persistent suspicious left renal mass, measuring 40 × 30 cm in size was detected with no change in its dimensions and appearance. Additionally, magnetic resonance imaging (MRI) scan revealed a bone lesion of 15 × 10 mm in the left hip, which was not present on previous MRI/CT scans. In view of the solid masses in the left kidney, and left hip on CT and MRI scan suspicious for a probably metastatic renal neoplasm, left radical nephrectomy via a left subcostal transperitoneal incision was performed. The ultimate pathological report of the patient was also supported the diagnosis of Masson's tumor and any renal malignancy was not encountered The patient was discharged on the 4(th) postoperative day and has been followed up for 4 months without any problems. In this case, we discuss the clinical features, histopathological characteristics, and the management of Masson's tumor of the kidney in the light of the current literature. PMID:27635297

  13. Thyroid Storm Complicated by Bicytopenia and Disseminated Intravascular Coagulation

    PubMed Central

    Tokushima, Yoshinori; Sakanishi, Yuta; Nagae, Kou; Tokushima, Midori; Tago, Masaki; Tomonaga, Motosuke; Yoshioka, Tsuneaki; Hyakutake, Masaki; Sugioka, Takashi; Yamashita, Shu-ichi

    2014-01-01

    Patient: Male, 23 Final Diagnosis: Thyroid storm Symptoms: Delirium • diarrhea • fever • hypertension • hyperventilation • tachycardia • weight loss Medication: — Clinical Procedure: — Specialty: Endocrinology and Metabolic Objective: Unusual clinical course Background: The clinical presentation of thyroid storm includes fever, tachycardia, hypertension, and neurological abnormalities. It is a serious condition with a high mortality rate. Furthermore, some other complications affect the clinical course of thyroid storm. Although it is reported that prognosis is poor when thyroid storm is complicated by disseminated intravascular coagulation syndrome (DIC) and leukopenia, reports of such cases are rare. Case Report: A 23-year-old man presented with delirium, high pyrexia, diarrhea, and weight loss of 18 kg over 2 months. According to the criteria of Burch and Wartofsky, he was diagnosed with thyroid storm on the basis of his symptom-complex and laboratory data that confirmed the presence of hyperthyroidism. Investigations also found leukopenia, thrombocytopenia, and disseminated intravascular coagulation, all of which are very rare complications of thyroid storm. We successfully treated him with combined therapy including anti-thyroid medication, despite leukopenia. Conclusions: Early diagnosis and treatment are essential in ensuring a good outcome for patients with this rare combination of medical problems. PMID:25072662

  14. [Disseminated intravascular coagulation. Case series and literature review].

    PubMed

    Del Carpio-Orantes, Luis; García-Ortiz, Jorge José

    2014-01-01

    INTRODUCCIÓN: la coagulación intravascular diseminada es una entidad caracteriza por activación de la cascada de la coagulación y fibrinólisis endógena, que puede provocar la muerte. Nuestros objetivos fueron identificar la incidencia de coagulación intravascular diseminada, sus agentes etiológicos y la correlación entre la puntuación de la escala Apache II y la propuesta por la Sociedad Internacional de Trombosis y Hemostasia para el diagnóstico de esta entidad. MÉTODOS: estudio retrospectivo, observacional y descriptivo de pacientes atendidos en una unidad de cuidados intensivos en un periodo de 17 meses. Se analizó etiología, edad, sexo, conteo de plaquetas, coagulograma, niveles de fibrinógeno sérico y cuantificación del dímero D. Se calculó la puntuación de la escala propuesta por la Sociedad Internacional de Trombosis y Hemostasia y de la escala APACHE II.

  15. A short contemporary history of disseminated intravascular coagulation.

    PubMed

    Levi, Marcel; van der Poll, Tom

    2014-11-01

    Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic intravascular activation of coagulation, leading to a widespread deposition of fibrin in the circulation. There is ample experimental and pathological evidence that the fibrin deposition contributes to multiple organ failure. The massive and ongoing activation of coagulation may result in depletion of platelets and coagulation factors, which may cause bleeding (consumption coagulopathy). The syndrome of DIC is well known in the medical literature for centuries, although a more precise description of the underlying mechanisms had to await the 20th century. Initial ideas on a role of the contact activation system as the primary trigger for the systemic activation of coagulation as well as a presumed hyperfibrinolytic response in DIC have been found to be misconceptions. Experimental and clinical evidence now indicate that the initiation of coagulation in DIC is caused by tissue factor expression, which in combination with downregulated physiological anticoagulant pathways and impaired fibrinolysis leads to widespread fibrin deposition. In addition, an extensive bidirectional interaction between coagulation and inflammation may further contribute to the pathogenesis of DIC.

  16. Fatal Cryocrystalglobulinemia With Intravascular and Renal Tubular Crystalline Deposits.

    PubMed

    DeLyria, Paul A; Avedschmidt, Sarah E; Yamada, Chisa; Farkash, Evan A

    2016-05-01

    Cryocrystalglobulinemia is a rare variant of cryoglobulinemia in which monoclonal immunoglobulins self-assemble into crystalline arrays. We report a case of a 53-year-old man who presented with systemic thrombotic microangiopathy causing multiorgan failure, including decreased kidney, lung, and gastrointestinal function; skin necrosis; and mental status changes. Skin and kidney biopsy specimens showed intravascular thrombi, along with intravascular, intratubular, and periglomerular crystalline deposits. Typical morphologic features of cryoglobulinemia, such as a leukocytoclastic vasculitis and pseudothrombi, were absent. Spindled crystals precipitated in the cryoglobulin assay, and immunofixation showed them to be composed of monoclonal immunoglobulin G κ light chains. Ultrastructural analysis demonstrated deposits to have an array-like substructure. The patient was successfully treated with a combination of plasmapheresis, steroids, and bortezomib, but experienced a relapse and died 12 months after his initial diagnosis. Cryocrystalglobulinemia causes significant morbidity and mortality and should be classified as a monoclonal gammopathy of renal significance when it occurs in patients not meeting diagnostic criteria for multiple myeloma. PMID:26775022

  17. Dominant neurologic symptomatology in intravascular large B-cell lymphoma.

    PubMed

    Kubisova, K; Martanovic, P; Sisovsky, V; Tomleinova, Z; Steno, A; Janega, P; Rychly, B; Babal, P

    2016-01-01

    Intravascular large B-cell lymphoma (IVLBCL) is a rare variant of extranodal large B-cell lymphoma and it is characterized by selective intravascular proliferation of malignant cells. Typical features of the disease include aggressive behavior, rapid and frequently fatal course. Clinical picture is non-specific and heterogeneous, depending on the affected organ. It is not uncommon that this unique type of lymphoma is diagnosed post mortem. Herein, we report two cases of IVLBCL with neurologic symptomatology. In our clinical study patient 1 was an 80-year-old male with mixed paraparesis of lower extremities and difficulties with sphincter control. Patient 2 (56-year-old male) had vision malfunction, mental status changes and defect in phatic and motor functions. In both cases definite diagnosis was established by histological examination of necroptic material. We propose to include IVLBCL in differential diagnostic considerations in patients presenting with gradually impairing neurological status and spinal cord damage of unknown etiology (Fig. 2, Ref. 9). PMID:27546361

  18. The syndrome of pneumococcemia, disseminated intravascular coagulation and asplenia.

    PubMed Central

    Kingston, M E; MacKenzie, C R

    1979-01-01

    A 58-year-old man who survived an episode of fulminant pneumococcal septicemia with disseminated intravascular coagulation had undergone splenectomy 23 years previously. In the literature there are 25 reported cases of fulminant septicemia and disseminated intravascular coagulation associated with asplenia in adults (excluding cases in which corticosteroid or immunosuppressive therapy was given). The pneumococcus was responsible for all of these cases as well. The mortality in this series was more than 90%, and death occurred within 24 hours of presentation at hospital in almost 70% of the fatal cases and was associated with high-density bacteremia and adrenal hemorrhage. Gram-staining of the buffy coat of the peripheral blood or the exudate from purpuric skin lesions was carried out in only 6 of the 26 cases but yielded positive results in all but 1. It is concluded that a diagnosis of septicemia in asplenic adults can be established within a short time of presentation on the basis of statistical probability and the results of Gram-staining of the peripheral blood and exudate from the skin lesions. Prevention appears to be the cornerstone of management because of the variable interval from splenectomy to the onset of the syndrome and the high mortality. Images FIG. 1 PMID:38002

  19. Ultrasound Annual, 1983

    SciTech Connect

    Sanders, R.C.; Hill, M.C.

    1983-01-01

    The 1983 edition of Ultrasound Annual features a state-of-the-art assessment of real-time ultrasound technology and a look at improvements in real-time equipment. Chapters discuss important new obstetric applications of ultrasound in measuring fetal umbilical vein blood flow and monitoring ovarian follicular development in vivo and in vitro fertilization. Other topics covered include transrectal prostate ultrasound using a linear array system; ultrasound of the common bile duct; ultrasound in tropical diseases; prenatal diagnosis of craniospinal anomalies; scrotal ultrasonography; opthalmic ultrasonography; and sonography of the upper abdominal venous system.

  20. Transvaginal ultrasound (image)

    MedlinePlus

    Transvaginal ultrasound is a method of imaging the genital tract in females. A hand held probe is inserted directly ... vaginal cavity to scan the pelvic structures, while ultrasound pictures are viewed on a monitor. The test ...

  1. Abdominal ultrasound (image)

    MedlinePlus

    Abdominal ultrasound is a scanning technique used to image the interior of the abdomen. Like the X-ray, MRI, ... it has its place as a diagnostic tool. Ultrasound scans use high frequency sound waves to produce ...

  2. Medical Ultrasound Imaging.

    ERIC Educational Resources Information Center

    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)

  3. Ultrasound Tissue Characterization of Vulnerable Atherosclerotic Plaque

    PubMed Central

    Picano, Eugenio; Paterni, Marco

    2015-01-01

    A thrombotic occlusion of the vessel fed by ruptured coronary atherosclerotic plaque may result in unstable angina, myocardial infarction or death, whereas embolization from a plaque in carotid arteries may result in transient ischemic attack or stroke. The atherosclerotic plaque prone to such clinical events is termed high-risk or vulnerable plaque, and its identification in humans before it becomes symptomatic has been elusive to date. Ultrasonic tissue characterization of the atherosclerotic plaque is possible with different techniques—such as vascular, transesophageal, and intravascular ultrasound—on a variety of arterial segments, including carotid, aorta, and coronary districts. The image analysis can be based on visual, video-densitometric or radiofrequency methods and identifies three distinct textural patterns: hypo-echoic (corresponding to lipid- and hemorrhage-rich plaque), iso- or moderately hyper-echoic (fibrotic or fibro-fatty plaque), and markedly hyperechoic with shadowing (calcific plaque). Hypoechoic or dishomogeneous plaques, with spotty microcalcification and large plaque burden, with plaque neovascularization and surface irregularities by contrast-enhanced ultrasound, are more prone to clinical complications than hyperechoic, extensively calcified, homogeneous plaques with limited plaque burden, smooth luminal plaque surface and absence of neovascularization. Plaque ultrasound morphology is important, along with plaque geometry, in determining the atherosclerotic prognostic burden in the individual patient. New quantitative methods beyond backscatter (to include speed of sound, attenuation, strain, temperature, and high order statistics) are under development to evaluate vascular tissues. Although not yet ready for widespread clinical use, tissue characterization is listed by the American Society of Echocardiography roadmap to 2020 as one of the most promising fields of application in cardiovascular ultrasound imaging, offering unique

  4. Ultrasound Imaging System Video

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this video, astronaut Peggy Whitson uses the Human Research Facility (HRF) Ultrasound Imaging System in the Destiny Laboratory of the International Space Station (ISS) to image her own heart. The Ultrasound Imaging System provides three-dimension image enlargement of the heart and other organs, muscles, and blood vessels. It is capable of high resolution imaging in a wide range of applications, both research and diagnostic, such as Echocardiography (ultrasound of the heart), abdominal, vascular, gynecological, muscle, tendon, and transcranial ultrasound.

  5. Acute renal failure and intravascular hemolysis following henna ingestion.

    PubMed

    Qurashi, Hala E A; Qumqumji, Abbas A A; Zacharia, Yasir

    2013-05-01

    The powder of henna plant (Lawsonia inermis Linn.) is extensively used as a decorative skin paint for nail coloring and as a hair dye. Most reports of henna toxicity have been attributed to adding a synthetic dye para-phenylenediamine (PPD). PPD is marketed as black henna added to natural henna to accentuate the dark color and shorten the application time. PPD toxicity is well known and extensively reported in medical literature. We report a case of a young Saudi male who presented with characteristic features of acute renal failure and intravascular hemolysis following ingestion of henna mixture. Management of PPD poisoning is only supportive and helpful only if instituted early. Diagnosis requires a high degree of clinical suspicion, as the clinical features are quite distinctive. PMID:23640630

  6. Mathematical Modeling of Intravascular Blood Coagulation under Wall Shear Stress.

    PubMed

    Rukhlenko, Oleksii S; Dudchenko, Olga A; Zlobina, Ksenia E; Guria, Georgy Th

    2015-01-01

    Increased shear stress such as observed at local stenosis may cause drastic changes in the permeability of the vessel wall to procoagulants and thus initiate intravascular blood coagulation. In this paper we suggest a mathematical model to investigate how shear stress-induced permeability influences the thrombogenic potential of atherosclerotic plaques. Numerical analysis of the model reveals the existence of two hydrodynamic thresholds for activation of blood coagulation in the system and unveils typical scenarios of thrombus formation. The dependence of blood coagulation development on the intensity of blood flow, as well as on geometrical parameters of atherosclerotic plaque is described. Relevant parametric diagrams are drawn. The results suggest a previously unrecognized role of relatively small plaques (resulting in less than 50% of the lumen area reduction) in atherothrombosis and have important implications for the existing stenting guidelines.

  7. Basic studies on intravascular low-intensity laser therapy

    NASA Astrophysics Data System (ADS)

    Liu, Timon Cheng-Yi; Duan, Rui; Wang, Shuang-Xi; Liu, Jiang; Cui, Li-Ping; Jin, Hua; Liu, Song-Hao

    2006-09-01

    Intravascular low intensity laser therapy (ILILT) was originally put forward in USA in 1982, but popularized in Russia in 1980s and in China in 1990s, respectively. A randomized placebo-controlled study has shown ILILT clinical efficacy in patients suffering from rheumatoid arthritis. As Chinese therapeutic applications of ILILT were the most widely in the world, its basic research, such as intracellular signal transduction research, blood research in vitro, animal blood research in vivo, human blood research in vivo and traditional Chinese medicine research, was also very progressive in China. Its basic studies will be reviewed in terms of the biological information model of photobiomodulation in this paper. ILILT might work in view of its basic studies, but the further randomized placebo-controlled trial and the further safety research should be done.

  8. [Traumatic abruption of the placenta with disseminated intravascular coagulation].

    PubMed

    Benz, R; Malär, A-U; Benz-Wörner, J; Scherer, M; Hodel, M; Gähler, A; Haberthür, C; Konrad, C

    2012-10-01

    Trauma in pregnancy is infrequent and a systematic primary strategy constitutes a real challenge for the interdisciplinary team. With a high fetal mortality rate and a substantial maternal mortality rate traumatic placental abruption is a severe emergency which every anesthetist should be aware of. After hemodynamic stabilization of the mother and control of the viability of the fetus the therapy of traumatic placental abruption consists mostly of an immediate caesarean section. Coagulopathy by depletion of coagulation factors as well as disseminated intravascular coagulation (DIC) have to be expected and consequently a massive blood loss must be anticipated. Thrombelastography provides assistance for fast differential diagnosis and goal-directed treatment of the disturbed sections of the coagulation cascade.

  9. Thrombocytopenia and thrombosis in disseminated intravascular coagulation (DIC).

    PubMed

    Kitchens, Craig S

    2009-01-01

    Disseminated intravascular coagulation (DIC) is the physiologic result of pathologic overstimulation of the coagulation system. Despite multiple triggers, a myriad of laboratory abnormalities, and a clinical presentation ranging from gross hemostatic failure to life-threatening thrombosis, or even both simultaneously, a simplified clinical approach augmented by a few readily available tests allows prompt identification of the process and elucidation of treatment opportunities. Platelet counts in DIC may be low, especially in acute sepsis-associated DIC, yet increased in malignancy-associated chronic DIC. Thrombotic risk is not a function of the platelet count, and thrombocytopenia does not protect the patient from thrombosis. The stratification of both thrombotic risk and hemorrhagic risk will be addressed.

  10. Disseminated intravascular coagulation in obstetric and gynecologic disorders.

    PubMed

    Montagnana, Martina; Franchi, Massimo; Danese, Elisa; Gotsch, Francesca; Guidi, Gian Cesare

    2010-06-01

    Disseminated intravascular coagulation (DIC) is a syndrome characterized by a massive, widespread, and ongoing activation of the coagulation system, secondary to a variety of clinical conditions. Many obstetric complications, such as abruptio placentae, amniotic fluid embolism, endotoxin sepsis, retained dead fetus, post-hemorrhagic shock, hydatidiform mole, and gynecologic malignancies, might trigger DIC. In these gynecologic and obstetric settings, DIC is usually associated with high mortality and morbidity rates. No single laboratory test is sensitive or specific enough to diagnose DIC definitively, but it can be diagnosed by using a combination of multiple clinical and laboratory tests that reflect the pathophysiology of the syndrome. At present, the therapeutical approach to pregnancy- and gynecologic-related DIC comprises the specific and aggressive treatment of the underlying disease, eventually followed by a supportive blood product replacement therapy and restoration of physiological anticoagulant pathways. This article reviews the etiopathogenesis, clinical manifestations, laboratory diagnosis, and therapy of pregnancy- and gynecologic-related DIC.

  11. Potential diagnostic markers for disseminated intravascular coagulation of sepsis.

    PubMed

    Iba, Toshiaki; Ito, Takashi; Maruyama, Ikuro; Jilma, Bernd; Brenner, Thorsten; Müller, Marcella C A; Juffermans, Nicole P; Thachil, Jecko

    2016-03-01

    Disseminated intravascular coagulation (DIC) is an acquired thrombo-haemorrhagic disorder which arises in clinical scenarios like sepsis, trauma and malignancies. The clinic-laboratory diagnosis of DIC is made in a patient who develops the combination of laboratory abnormalities in the appropriate clinical scenario. The most common laboratory parameters in this setting have been the clotting profile, platelet count, serum fibrinogen and fibrin degradation markers. These tests had the advantage that they could be performed easily and in most laboratories. However, with the better understanding of the pathophysiology of DIC, in recent years, more specific tests have been suggested to be useful in this setting. The newer tests can also prove to be useful in prognostication in DIC. In addition, they may provide assistance in the selection and monitoring of patients diagnosed with DIC.

  12. Adaptive Estimation of Intravascular Shear Rate Based on Parameter Optimization

    NASA Astrophysics Data System (ADS)

    Nitta, Naotaka; Takeda, Naoto

    2008-05-01

    The relationships between the intravascular wall shear stress, controlled by flow dynamics, and the progress of arteriosclerosis plaque have been clarified by various studies. Since the shear stress is determined by the viscosity coefficient and shear rate, both factors must be estimated accurately. In this paper, an adaptive method for improving the accuracy of quantitative shear rate estimation was investigated. First, the parameter dependence of the estimated shear rate was investigated in terms of the differential window width and the number of averaged velocity profiles based on simulation and experimental data, and then the shear rate calculation was optimized. The optimized result revealed that the proposed adaptive method of shear rate estimation was effective for improving the accuracy of shear rate calculation.

  13. Advanced Congestive Heart Failure Associated With Disseminated Intravascular Coagulopathy.

    PubMed

    Sarcon, Annahita; Liu, Xiaoli; Ton, David; Haywood, James; Hitchcock, Todd

    2015-01-01

    Background. Disseminated intravascular coagulopathy (DIC) is a complication of an underlying disease and not a primary illness. It is most commonly associated with sepsis, trauma, obstetrical complications, and malignancies. There are very few cases in the literature illustrating the association between DIC and congestive heart failure. Findings. In this report, we present a case of severe congestive heart failure, leading to biventricular thrombi and subsequently DIC. Conclusion. We suggest that the association between congestive heart failure and DIC is an underrecognized one. Congestive heart failure continues to remain a major cause of morbidity and mortality despite advances in medical therapies. Thus far, the precise role of coagulation factors in congestive heart failure is unknown. Further investigations are needed to elucidate the pathophysiology of congestive heart failure and coagulation factors.

  14. Analysis of gas composition of intravascular bubbles produced by decompression.

    PubMed

    Ishiyama, A

    1983-06-01

    The gas composition of intravascular bubbles produced by decompression was investigated in rabbits using gas chromatography. The animals were exposed to 8 ATA for 30 min. All samples of bubbles were taken from the animals under 0.2 ATA pressure gradient so that no air could enter the sampling system from the outside. The percentage of carbon dioxide in the bubbles tended to decrease at first and then increased with post-decompression time. On the other hand, the percentage of oxygen tended to change in the opposite manner. Actual analysis of bubbles in the living decompressed animals indicates that carbon dioxide may be an outstanding factor in the initiation and early growth of bubbles. In view of this, Haldane's classical maximum supersaturation limit for avoiding decompression sickness should be examined and possibly modified for gases other than nitrogen.

  15. Mathematical Modeling of Intravascular Blood Coagulation under Wall Shear Stress

    PubMed Central

    Rukhlenko, Oleksii S.; Dudchenko, Olga A.; Zlobina, Ksenia E.; Guria, Georgy Th.

    2015-01-01

    Increased shear stress such as observed at local stenosis may cause drastic changes in the permeability of the vessel wall to procoagulants and thus initiate intravascular blood coagulation. In this paper we suggest a mathematical model to investigate how shear stress-induced permeability influences the thrombogenic potential of atherosclerotic plaques. Numerical analysis of the model reveals the existence of two hydrodynamic thresholds for activation of blood coagulation in the system and unveils typical scenarios of thrombus formation. The dependence of blood coagulation development on the intensity of blood flow, as well as on geometrical parameters of atherosclerotic plaque is described. Relevant parametric diagrams are drawn. The results suggest a previously unrecognized role of relatively small plaques (resulting in less than 50% of the lumen area reduction) in atherothrombosis and have important implications for the existing stenting guidelines. PMID:26222505

  16. Impact of Intravascular Hemolysis in Malaria on Liver Dysfunction

    PubMed Central

    Dey, Sumanta; Bindu, Samik; Goyal, Manish; Pal, Chinmay; Alam, Athar; Iqbal, Mohd. Shameel; Kumar, Rahul; Sarkar, Souvik; Bandyopadhyay, Uday

    2012-01-01

    We have investigated the impact of persistent intravascular hemolysis on liver dysfunction using the mouse malaria model. Intravascular hemolysis showed a positive correlation with liver damage along with the increased accumulation of free heme and reactive oxidants in liver. Hepatocytes overinduced heme oxygenase-1 (HO-1) to catabolize free heme in building up defense against this pro-oxidant milieu. However, in a condition of persistent free heme overload in malaria, the overactivity of HO-1 resulted in continuous transient generation of free iron to favor production of reactive oxidants as evident from 2′,7′-dichlorofluorescein fluorescence studies. Electrophoretic mobility shift assay documented the activation of NF-κB, which in turn up-regulated intercellular adhesion molecule 1 as evident from chromatin immunoprecipitation studies. NF-κB activation also induced vascular cell adhesion molecule 1, keratinocyte chemoattractant, and macrophage inflammatory protein 2, which favored neutrophil extravasation and adhesion in liver. The infiltration of neutrophils correlated positively with the severity of hemolysis, and neutrophil depletion significantly prevented liver damage. The data further documented the elevation of serum TNFα in infected mice, and the treatment of anti-TNFα antibodies also significantly prevented neutrophil infiltration and liver injury. Deferoxamine, which chelates iron, interacts with free heme and bears antioxidant properties that prevented oxidative stress, NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Furthermore, the administration of N-acetylcysteine also prevented NF-κB activation, neutrophil infiltration, hepatocyte apoptosis, and liver damage. Thus, hepatic free heme accumulation, TNFα release, oxidative stress, and NF-κB activation established a link to favor neutrophil infiltration in inducing liver damage during hemolytic conditions in malaria. PMID:22696214

  17. Intravascular large B-cell lymphoma with hemophagocytic syndrome (Asian variant) in a Caucasian patient.

    PubMed

    Fung, Kar-Ming; Chakrabarty, Jennifer H; Kern, William F; Magharyous, Hany; Gehrs, Bradley C; Li, Shibo

    2012-01-01

    Intravascular lymphoma is an aggressive and extremely rare extranodal lymphoma with neoplastic lymphoid cells confined exclusively within intravascular spaces. The histopathologic findings are subtle due to the rarity of the neoplastic cells in blood vessels. Clinical presentations are non-specific and focal space-occupying lesions or lymphoadenopathy are always lacking. It is a diagnostic challenge. Secondary hemophagocytic syndrome is uncommon and is typically associated with infection, malignancy, and suppressed immune states. Intravascular lymphoma has a strong association with hemophagocytic syndrome in Asian patients, the so-called "Asian variant", but not in Western patients. We report a case of intravascular B-cell lymphoma in a Caucasian patient associated with secondary hemophagocytic syndrome. The patient was diagnosed by core liver biopsy and successfully treated. This case demonstrates the importance of high index of suspicion and astute histopathologic examination in recognition of this unusual clinical and pathologic combination.

  18. New trick for removal of intravascular retained foreign body: a case report and review of literature.

    PubMed

    Mousa, Albeir Y; Gill, Gurpreet; Aburahma, Ali F

    2014-01-01

    A 54-year-old male presented to the vascular service for an urgent inpatient consultation. During an infusaport removal, the catheter was accidentally disconnected and lost intravascularly within the left subclavian vein, with the tip still in the right ventricle. We report on a novel technique for removing such intravascular foreign bodies (FBs), which will add a valuable technical option to our existing armamentarium regarding intracorporeal FB removal.

  19. Bubbles Quantified In vivo by Ultrasound Relates to Amount of Gas Detected Post-mortem in Rabbits Decompressed from High Pressure.

    PubMed

    Bernaldo de Quirós, Yara; Møllerløkken, Andreas; Havnes, Marianne B; Brubakk, Alf O; González-Díaz, Oscar; Fernández, Antonio

    2016-01-01

    The pathophysiological mechanism of decompression sickness is not fully understood but there is evidence that it can be caused by intravascular and autochthonous bubbles. Doppler ultrasound at a given circulatory location is used to detect and quantify the presence of intravascular gas bubbles as an indicator of decompression stress. In this manuscript we studied the relationship between presence and quantity of gas bubbles by echosonography of the pulmonary artery of anesthetized, air-breathing New Zealand White rabbits that were compressed and decompressed. Mortality rate, presence, quantity, and distribution of gas bubbles elsewhere in the body was examined postmortem. We found a strong positive relationship between high ultrasound bubble grades in the pulmonary artery, sudden death, and high amount of intra and extra vascular gas bubbles widespread throughout the entire organism. In contrast, animals with lower bubble grades survived for 1 h after decompression until sacrificed, and showed no gas bubbles during dissection. PMID:27493634

  20. Bubbles Quantified In vivo by Ultrasound Relates to Amount of Gas Detected Post-mortem in Rabbits Decompressed from High Pressure

    PubMed Central

    Bernaldo de Quirós, Yara; Møllerløkken, Andreas; Havnes, Marianne B.; Brubakk, Alf O.; González-Díaz, Oscar; Fernández, Antonio

    2016-01-01

    The pathophysiological mechanism of decompression sickness is not fully understood but there is evidence that it can be caused by intravascular and autochthonous bubbles. Doppler ultrasound at a given circulatory location is used to detect and quantify the presence of intravascular gas bubbles as an indicator of decompression stress. In this manuscript we studied the relationship between presence and quantity of gas bubbles by echosonography of the pulmonary artery of anesthetized, air-breathing New Zealand White rabbits that were compressed and decompressed. Mortality rate, presence, quantity, and distribution of gas bubbles elsewhere in the body was examined postmortem. We found a strong positive relationship between high ultrasound bubble grades in the pulmonary artery, sudden death, and high amount of intra and extra vascular gas bubbles widespread throughout the entire organism. In contrast, animals with lower bubble grades survived for 1 h after decompression until sacrificed, and showed no gas bubbles during dissection. PMID:27493634

  1. Bubbles Quantified In vivo by Ultrasound Relates to Amount of Gas Detected Post-mortem in Rabbits Decompressed from High Pressure.

    PubMed

    Bernaldo de Quirós, Yara; Møllerløkken, Andreas; Havnes, Marianne B; Brubakk, Alf O; González-Díaz, Oscar; Fernández, Antonio

    2016-01-01

    The pathophysiological mechanism of decompression sickness is not fully understood but there is evidence that it can be caused by intravascular and autochthonous bubbles. Doppler ultrasound at a given circulatory location is used to detect and quantify the presence of intravascular gas bubbles as an indicator of decompression stress. In this manuscript we studied the relationship between presence and quantity of gas bubbles by echosonography of the pulmonary artery of anesthetized, air-breathing New Zealand White rabbits that were compressed and decompressed. Mortality rate, presence, quantity, and distribution of gas bubbles elsewhere in the body was examined postmortem. We found a strong positive relationship between high ultrasound bubble grades in the pulmonary artery, sudden death, and high amount of intra and extra vascular gas bubbles widespread throughout the entire organism. In contrast, animals with lower bubble grades survived for 1 h after decompression until sacrificed, and showed no gas bubbles during dissection.

  2. Pre-puncture ultrasound guided epidural insertion before vaginal delivery.

    PubMed

    Nassar, Mahmoud; Abdelazim, Ibrahim A

    2015-10-01

    Palpation method is widely used in clinical practice to identify the puncture site during combined spinal-epidural (CSE) blocks. Tuffier's line, is an anatomical landmark between two iliac crests (inter-cristal), which is widely used to identify the puncture site during CSE blocks is not always an indicator for specific vertebral level or inter-vertebral space. One hundred and Ten (110) women were scheduled for normal vaginal delivery and were randomized into two equal groups; palpation group and an ultrasound guided group to detect the efficacy of puncture ultrasound before CSE blocks to increase chances of successful CSE procedure on the first attempt and to reduce the number of attempts or punctures during insertion of CSE catheter. There were no significant differences between two studied groups regarding; maternal age, weight and height, while, there was a significant difference between two studied groups regarding; parity. Percentage of successful CSE procedure on the first attempt was significantly higher (67.27%) in ultrasound compared to palpation group (40%). Number of punctures (attempts) were significantly less in ultrasound (1.2 ± 0.6) compared to palpation group (2.3 ± 0.8) and the number of redirections was also significantly less in ultrasound (1.4 ± 0.5) compared to palpation group (2.8 ± 1.6). Although, time to identify puncture site was significantly longer in ultrasound compared to palpation group and total procedure time was longer in ultrasound (9.1 ± 1.5 min) compared to palpation group (6.2 ± 1.2 min), there was no significant difference between two studied groups regarding; time to identify puncture site and total procedure time. Two cases of dural puncture in palpation versus no cases in ultrasound group and two cases of intravascular catheter placement (one in each group), with no significant difference between two groups. Pre- puncture ultrasound guided epidural insertion before vaginal delivery, increases the chance of a

  3. IVUSAngio tool: a publicly available software for fast and accurate 3D reconstruction of coronary arteries.

    PubMed

    Doulaverakis, Charalampos; Tsampoulatidis, Ioannis; Antoniadis, Antonios P; Chatzizisis, Yiannis S; Giannopoulos, Andreas; Kompatsiaris, Ioannis; Giannoglou, George D

    2013-11-01

    There is an ongoing research and clinical interest in the development of reliable and easily accessible software for the 3D reconstruction of coronary arteries. In this work, we present the architecture and validation of IVUSAngio Tool, an application which performs fast and accurate 3D reconstruction of the coronary arteries by using intravascular ultrasound (IVUS) and biplane angiography data. The 3D reconstruction is based on the fusion of the detected arterial boundaries in IVUS images with the 3D IVUS catheter path derived from the biplane angiography. The IVUSAngio Tool suite integrates all the intermediate processing and computational steps and provides a user-friendly interface. It also offers additional functionality, such as automatic selection of the end-diastolic IVUS images, semi-automatic and automatic IVUS segmentation, vascular morphometric measurements, graphical visualization of the 3D model and export in a format compatible with other computer-aided design applications. Our software was applied and validated in 31 human coronary arteries yielding quite promising results. Collectively, the use of IVUSAngio Tool significantly reduces the total processing time for 3D coronary reconstruction. IVUSAngio Tool is distributed as free software, publicly available to download and use.

  4. Intravascular Large B-Cell Lymphoma: A Difficult Diagnostic Challenge.

    PubMed

    Khan, Maria S; McCubbin, Mark; Nand, Sucha

    2014-01-01

    Case Presentation. A 69-year-old Hispanic male, with a past history of diabetes and coronary disease, was admitted for fever, diarrhea, and confusion of 4 weeks duration. Physical examination showed a disoriented patient with multiple ecchymoses, possible ascites, and bilateral scrotal swelling. Hemoglobin was 6.7, prothrombin time (PT) 21.4 seconds with international normalized ratio 2.1, partial thromboplastin time (PTT) 55.6 seconds, fibrin split 10 µg/L, and lactate dehydrogenase (LDH) 1231 IU/L. Except for a positive DNA test for Epstein-Barr virus (EBV) infection, extensive diagnostic workup for infections, malignancy, or a neurological cause was negative. Mixing studies revealed a nonspecific inhibitor of PT and PTT but Factor VIII levels were normal. The patient was empirically treated with antibiotics but developed hypotension and died on day 27 of admission. At autopsy, patient was found to have intravascular diffuse large B-cell lymphoma involving skin, testes, lung, and muscles. The malignant cells were positive for CD20, CD791, Mum-1, and Pax-5 and negative for CD3, CD5, CD10, CD30, and Bcl-6. The malignant cells were 100% positive for Ki-67. Discussion. Intravascular large cell B-cell lymphoma (IVLBCL) is rare form of diffuse large B-cell lymphoma and tends to proliferate within small blood vessels, particularly capillaries and postcapillary venules. The cause of its affinity for vascular bed remains unknown. In many reports, IVLBCL was associated with HIV, HHV8, and EBV infections. The fact that our case showed evidence of EBV infection lends support to the association of this diagnosis to viral illness. The available literature on this subject is scant, and in many cases, the diagnosis was made only at autopsy. The typical presentation of this disorder is with B symptoms, progressive neurologic deficits, and skin findings. Bone marrow, spleen, and liver are involved in a minority of patients. Nearly all patients have elevated LDH, and about 65% are

  5. Intravascular papillary endothelial hyperplasia: histomorphological and immunohistochemical features

    PubMed Central

    2013-01-01

    Background Intravascular papillary endothelial hyperplasia (IPEH) is a benign intravascular process with features mimicking other benign and malignant vascular proliferations. IPEH lesions predominate in the head-neck region and the extremities. The characteristic histomorphological feature of IPEH is a papillary structure covered with hyperplastic endothelial cells within the vascular lumen. It is critical that this clinically benign lesion should not be mistaken for well-differentiated vascular tumors. In addition to the characteristic histological features, other useful diagnostic features included the intra-luminal location of the lesion, an intimate association with the organizing thrombus, the absence of necrosis, cellular pleomorphism, and mitotic activity. In addition, immunohistochemistry may indicate the vascular origin and proliferative index. In this study, we evaluated histomorphological and immunohistochemical findings (CD31, CD34, FVIII, type IV collagen, SMA, MSA, CD105, and Ki-67 staining) of ten IPEH cases. Methods Ten IPEH cases were re-examined for a panel of histomorphological and immunohistochemical features. CD31, CD34, FVIII, Type IV collagen, SMA and MSA antibodies utilized for immunohistochemical analysis. The histomorphological and immunohistochemical findings were evaluated by two independent pathologists using light microscopy. Results All ten cases involved intraluminal lesions with characteristic features of IPEH. All ten cases (100%) were stained positive for CD31 and CD34. The degree of staining with FVIII, type IV collagen, SMA, and MSA was variable. Conclusion In this series of specimens, CD31 and CD34 were the most sensitive markers indicating the vascular origin of the lesion. Staining for the other vascular markers (FVIII, type IV collagen, SMA and MSA) was variable. Different maturation degrees of lesions may account for the variation in immunohistochemical staining. Few previous investigations evaluated a wide range of

  6. Real-Time Intravascular Shear Stress in the Rabbit Abdominal Aorta

    PubMed Central

    Ai, Lisong; Yu, Hongyu; Dai, Wangde; Hale, Sharon L.; Kloner, Robert A.

    2012-01-01

    Fluid shear stress is intimately linked with the biological activities of vascular cells. A flexible microelectromechanical system (MEMS) sensor was developed to assess spatial- and temporal-varying components of intravascular shear stress (ISS) in the abdominal aorta of adult New Zealand white (NZW) rabbits. Real-time ISS (ISSreal-time) was analyzed in comparison with computational fluid dynamics (CFD) simulations for wall shear stress (WSS). Three-dimensional abdominal arterial geometry and mesh were created using the GAMBIT software. Simulation of arterial flow profiles was established by FLUENT. The Navier–Stokes equations were solved for non-Newtonian blood flow. The coaxial-wire-based MEMS sensor was deployed into the abdominal arteries of rabbits via a femoral artery cutdown. Based on the CFD analysis, the entrance length of the sensor on the coaxial wire (0.4 mm in diameter) was less than 10 mm. Three-dimensional fluoroscope and contrast dye allowed for visualization of the positions of the sensor and ratios of vessel to coaxial wire diameters. Doppler ultrasound provided the velocity profiles for the CFD boundary conditions. If the coaxial wire were positioned at the center of vessel, the CFD analysis revealed a mean ISS value of 31.1 with a systolic peak at 102.8 dyn · cm−2. The mean WSS was computed to be 10.1 dyn · cm−2 with a systolic peak at 33.2 dyn · cm−2, and the introduction of coaxial wire increased the mean WSS by 5.4 dyn · cm−2 and systolic peak by 18.0 dyn · cm−2. Experimentally, the mean ISS was 11.9 dyn · cm−2 with a systolic peak at 47.0 dyn · cm−2. The waveform of experimental ISS was similar to that of CFD solution with a 30.2% difference in mean and 8.9% in peak systolic shear stress. Despite the difference between CD and experimental results, the flexible coaxial-wire-based MEMS sensors provided a possibility to assess real-time ISS in the abdominal aorta of NZW rabbits. PMID:19527952

  7. [Ultrasound in pediatric dermatology].

    PubMed

    García-Martínez, F J; Muñoz-Garza, F Z; Hernández-Martín, A

    2015-11-01

    Cutaneous ultrasound is particularly useful in pediatric dermatology to diagnose numerous diseases without the need to use invasive tests. The present articles reviews some frequent dermatological entities in children whose study can be simplified through cutaneous ultrasound. This article also provides practical recommendations reported in the literature that may facilitate ultrasound examination, with special mention of benign tumoural disease, both congenital and acquired, and vascular anomalies.

  8. Children's (Pediatric) Abdominal Ultrasound Imaging

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  9. Ultrasound of the Thyroid Gland

    MedlinePlus

    ... waves. Ultrasound imaging, also called ultrasound scanning or sonography , involves the use of a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the ...

  10. Quantitative recovery of pulmonary intravascular macrophages from sheep lungs.

    PubMed

    Rogers, R A; Tasat, D R; Warner, A E; Brain, J D

    1994-12-01

    Pulmonary intravascular macrophages (PIMs) adhere to the endothelium of lung capillaries and sequester circulating particles and pathogens from the blood. Iron oxide (gamma Fe2O3) 5 mg/kg, administered intravenously, specifically labeled PIMs in situ within the living sheep. Attempts to isolate gamma Fe2O3-labeled PIMs using vascular perfusion (VP) procedures yielded few cells. To improve recovery of PIMs, a proteolytic lung digestion (PLD) procedure was developed. Following PLD, gamma Fe2O3-containing PIMs were recovered by magnets and the amount of gamma Fe2O3 present measured by fluxgate magnetometry. Proteolytic lung digestion recovered 34% of the total gamma Fe2O3 in lung samples and yielded 2 x 10(5) PIMs/g lung with 95% viability. In contrast, VP recovered only 3% of the total gamma Fe2O3 in the lung; furthermore, less than 2% of the recovered gamma Fe2O3 was cell associated. Proteolytic lung digestion followed by magnetic separation is an effective way to recover viable sheep PIMs for in vitro study. PMID:7996045

  11. Microbial diversity on intravascular catheters from paediatric patients.

    PubMed

    Zhang, L; Marsh, N; Long, D; Wei, M; Morrison, M; Rickard, C M

    2015-12-01

    Microorganisms play important roles in intravascular catheter (IVC)-related infections, which are the most serious complications in children with IVCs, leading to increased hospitalisation, intensive care admissions, extensive antibiotic treatment and mortality. A greater understanding of bacterial communities is needed in order to improve the management of infections. We describe here the systematic culture-independent evaluation of IVC bacteriology in IVC biofilms. Twenty-four IVC samples (six peripherally inserted central catheters, eight central venous catheters and ten arterial catheters) were collected from 24 paediatric patients aged 0 to 14 years old. Barcoded amplicon libraries produced from genes coding 16S rRNA and roll-plate culture methods were used to determine the microbial composition of these samples. From a total of 1,043,406 high-quality sequence reads, eight microbial phyla and 136 diverse microbial genera were detected, separated into 12,224 operational taxonomic units (OTUs). Three phyla (Actinobacteria, Firmicutes and Proteobacteria) predominate the microorganism on the IVC surfaces, with Firmicutes representing nearly half of the OTUs found. Among the Firmicutes, Staphylococcus (15.0% of 16S rRNA reads), Streptococcus (9.6%) and Bacillus (6.1%) were the most common. Community composition did not appear to be affected by patients' age, gender, antibiotic treatment or IVC type. Differences in IVC microbiota were more likely associated with events arising from catheter dwell time, rather than the type of IVC used. PMID:26515578

  12. Impact of microbial attachment on intravascular catheter-related infections.

    PubMed

    Zhang, Li; Gowardman, John; Rickard, Claire M

    2011-07-01

    Intravascular catheters (IVCs) are the most frequently used medical devices in hospitals. However, they are associated with life-threatening IVC-related bloodstream infection (IVC-BSI), which is one of the main hospital-acquired infections, and continue to be associated with morbidity, mortality and additional medical cost. Most published studies focus on measuring the rate of IVC-BSIs and addressing their importance, but only a few studies have mentioned the possible routes for microbes entering the bloodstream, which would help in developing effective prevention methods, and large trial studies are lacking. Some studies on IVC-BSIs have reported the most frequently isolated microbes, but caution needs to be made since many fastidious microbes are not isolated under current laboratory conditions. Although it is known that microbes colonise IVC surfaces and develop biofilms, leading to IVC-BSI, the relationships of microbial biofilms with patients' symptoms or outcomes remain unclear. Here we discuss the knowledge gained from microbial research in other (non-IVC) medical and non-medical applications that may be helpful in understanding the IVC context. In addition, published theory and data regarding microbial colonisation and biofilm development specifically in IVCs are reviewed. More research is needed to explore mechanisms of IVC-BSI and to provide superior prevention strategies.

  13. Acoustic determination of early stages of intravascular blood coagulation.

    PubMed

    Uzlova, Svetlana G; Guria, Konstantin G; Guria, Georgy Th

    2008-10-13

    The blood coagulation system (BCS) is a complex biological system playing a principal role in the maintenance of haemostasis. Insufficient activity of the BCS may lead to bleeding and blood loss (e.g. in the case of haemophilia). On the other hand, excessive activity may cause intravascular blood coagulation, thromboses and embolization. Most of the methods currently used for BCS monitoring suffer from the major disadvantage of being invasive. The purpose of the present work is to demonstrate the feasibility of using ultrasonic methods for non-invasive registration of the early stages of blood coagulation processes in intensive flows. With this purpose, a special experimental set-up was designed, facilitating the simultaneous detection of optical and acoustic signals during the clotting process. It was shown that (i) as microemboli appear in the flow during the early stage of blood coagulation, the intensity of the Doppler signal increases twofold, and (ii) microemboli formation in the early stages of blood clotting always reveals itself through an acoustic contrast. Both of these effects are well defined, so we hope that they may be used for non-invasive BCS monitoring in clinical practice.

  14. [Progress in diagnosis and treatment for disseminated intravascular coagulation].

    PubMed

    Wada, Hideo; Matsumoto, Takeshi; Aota, Takumi; Yamashita, Yoshiki

    2015-02-01

    As the development of a hypercoagulable state in the setting of disseminated intravascular coagulation (DIC) induces localized infection, therapy for DIC should be evaluated according to the findings of examinations for both severe sepsis and DIC. DIC is classified into the following types: "bleeding type," "organ failure type," "asymptomatic type," and "complication type." The "bleeding type" and "organ failure type" are considered to reflect the "plasmin inhibitor (PI) deficiency type" and "antithrombin (AT) deficiency type," respectively. In order to improve the diagnosis of DIC, in particular limitations in global coagulation tests, the Japanese Society of Thrombosis and Hemostasis recently proposed tentative diagnostic criteria for DIC using hemostatic molecular markers and AT. The recommendations for treatment of DIC, especially the use of AT concentrates, recombinant activated protein C and thrombomodulin, vary among several guidelines for the management of DIC. These agents inhibit the effects of key proteases in activating coagulation and consequently exert an anti-inflammatory effect on DIC. Hence, it is necessary to extensively evaluate these agents in well-conducted clinical trials.

  15. Back to the future: testing in disseminated intravascular coagulation.

    PubMed

    Toh, Cheng-Hock; Downey, Colin

    2005-11-01

    Following on from the first clinical observations on disseminated intravascular coagulation (DIC) in the nineteenth century, the dawn of laboratory testing for DIC began with the availability of assays that characterized the extrinsic and intrinsic pathways of coagulation. Markedly increased clotting times were the hallmark of DIC. As the understanding of the biochemistry of haemostasis and thrombosis improved, new tests were developed based on the molecular players that participate in the process. However, many are non-specific for DIC and/or are unwieldy in performance to keep apace with the demands of the acute clinical setting. The renewed emphasis in DIC for the modern laboratory of the twenty-first century has seen a return to the simple, rapid and practical global tests of coagulation within scoring systems that also capture the pathophysiological continuum by trend analysis. Additionally, new technologies based on these simple tests of coagulation hold promise in also indicating the in vivo interplay between coagulation and inflammation during DIC.

  16. Diagnostic criteria and laboratory tests for disseminated intravascular coagulation.

    PubMed

    Wada, Hideo; Matsumoto, Takeshi; Hatada, Tuyoshi

    2012-12-01

    Three diagnostic criteria for disseminated intravascular coagulation (DIC) have been established by the Japanese Ministry of Health, Labor and Welfare, the International Society on Thrombosis and Hemostasis (ISTH) and the Japanese Association for Acute Medicine. The diagnostic criteria involving global coagulation tests, such as the Japanese Ministry of Health, Labor and Welfare criteria and the ISTH overt diagnostic criteria, are first-generation DIC diagnostic criteria, those involving global coagulation tests and changes in these tests such as the Japanese Association for Acute Medicine criteria, are second-generation DIC diagnostic criteria, and those including non-overt DIC diagnostic criteria involving global coagulation tests, changes in these tests and hemostatic molecular markers will be the future (third-generation) DIC diagnostic criteria. There are no significant differences in the three diagnostic criteria with respect to predicting poor outcomes. Therefore, the third generation of diagnostic criteria including hemostatic molecular markers is expected to be established. Standardization and the determination of adequate cutoff values should be required for each laboratory test.

  17. Optimization of intravascular brachytherapy treatment planning in peripheral arteries.

    PubMed

    Zhou, Zhengdong; Haigron, Pascal; Shu, Huazhong; Yu, Wenxue; Moisan, Cécile; Manens, Jean-Pierre; Lucas, Antoine; Luo, Limin

    2007-09-01

    This work deals with the treatment planning optimization for intravascular brachytherapy (IVB) in peripheral arteries. The objective is both to quantitatively study the validity of different hypotheses required for a reliable application of the treatment with current techniques, and to contribute to the definition and the specification of a new optimized procedure taking into account the actual patient's vessel geometry. The detection of vascular luminal surface was performed by an image analysis process, i.e., virtual active navigation, applied to standard CT data. Dose distribution was calculated according to the formalism proposed and recommended by the AAPM in TG43 and TG60. A method combining simulated annealing and BFGS algorithms was applied to optimize the parameters associated with the dwell points such as their number, positions, and dwell times. Dose-surface histogram (DSH) was used to evaluate the dose distribution results. Four levels of accuracy in target surface description were tested. The application of this optimization method to four different CT data sets including patient data, phantom and animal models showed that the treatment plan can be improved when the actual vessel geometry has been taken into account.

  18. Light intensity matching between different intravascular optical coherence tomography systems

    NASA Astrophysics Data System (ADS)

    Liu, Shengnan; Eggermont, Jeroen; Nakatani, Shimpei; Lelieveldt, Boudewijn P. F.; Dijkstra, Jouke

    2016-02-01

    Currently two commercial intravascular optical coherence tomography (IVOCT) systems are available: Illumien Optis from St. Jude Medical (SJM) and Lunawave from Terumo. Both systems store the light intensity data in a raw vendor specific polar format. However, whereas SJM uses 16-bits per pixel Terumo uses 8-bits meaning the intensity values are in different ranges. This complicates quantitative light intensity based analysis when comparing results based on data from both systems. Therefore, this work aims to find an intensity transformation function from Terumo's 8-bit OFDI data to SJM's 16-bit range. The data consists of 8 pullbacks, 4 acquired with each system in the same arteries of 2 different patents pre- and post-stenting implantation. A total of 133 matching sections without stent struts from the two sets of pullbacks were identified based on landmarks such as side-branches and calcified regions. Since the main region of interest in the image is the tissue region only the pixels within 2mm behind the lumen border are used. In order to match the SJM data range, the Terumo data was rescaled and cumulative distribution functions (CDF) were calculated based on the histogram distributions. Comparing these CDFs, the transformation function can be determined. Application of this transformation function not only improves the visual similarity of matching slices it can also be used for further quantitative analysis.

  19. Disseminated intravascular coagulopathy: manifestations after a routine dental extraction.

    PubMed

    Peters, Kelly A; Triolo, Peter T; Darden, Daryle L

    2005-04-01

    Clinical signs and symptoms of acute disseminated intravascular coagulopathy (DIC) include bleeding from body orifices, such as the nose, mouth, or ear, bleeding from an intravenous (IV) site, areas of ecchymosis, or blood in the urine or stool. The underlying disease triggering DIC usually determines the clinical presentation. However, patients with chronic DIC (compensated DIC) may possess subclinical signs and symptoms, and the bleeding disorder may only be identified through laboratory findings. In this compensated form, the triggering factor is exposed slowly and in small amounts (seen in malignancies and vasculitis), allowing replenishing of the augmented factors by the liver, adequate reticuloendothelial clearance of fibrin degradation products, and increased production of platelets, which prevent secondary fibrinolysis and the signs of bleeding. 1,4 We report a case of an 82-year-old male who presented to the emergency room 24 hours after a routine dental extraction with bleeding from the tooth socket, severe hypotension, and presence of ecchymosis on his chest. Clinical and radiographic exam revealed multiple thoracic and abdominal aortic aneurysms, as well as infrarenal and iliac aneurysms, continuous oral hemorrhage, and a unique presentation rarely documented in the literature: a bleeding tooth socket as the initial clinical sign and presentation of DIC.

  20. Low-artifact intravascular devices: MR imaging evaluation.

    PubMed

    Teitelbaum, G P; Ortega, H V; Vinitski, S; Stern, H; Tsuruda, J S; Mitchell, D G; Rifkin, M D; Bradley, W G

    1988-09-01

    Flow-phantom magnetic resonance (MR) imaging, with use of both spin-echo (SE) and gradient-echo (GRE) techniques at 1.5 T, was performed on the percutaneous Greenfield (beta-III titanium alloy [TMA wire]), Amplatz (MP32-N alloy), and Simon nitinol filters and TMA wire facsimiles of the bird's nest, Gunther, new retrievable, and Amplatz vena caval filters. SE imaging allowed detection of thrombi as small as 5 X 5 mm trapped within the percutaneous Greenfield, Simon nitinol, and TMA-wire facsimile filters; with the MP32-N Amplatz filter, a larger volume of thrombus (10 X 20-mm clots) was necessary for clot detection. GRE imaging allowed detection of intraluminal tilting of the percutaneous Greenfield and facsimile Amplatz (TMA-wire) filters. GRE imaging was useful for demonstrating postfilter turbulence due to clots, which was greatest for the Amplatz filter. Imaging of facsimile vascular devices made of tantalum or TMA wire did not cause the severe "black-hole" MR artifacts typical of the stainless-steel devices. SE and GRE imaging were very useful for determining caval patency in two patients with previously placed Mobin-Uddin filters. Noninvasive MR evaluation of blood vessels in the presence of a variety of low-artifact intravascular devices appears feasible. PMID:3406402

  1. Effect of intravascular cellular aggregate dissolution in postoperative patients.

    PubMed Central

    Dawidson, I; Barrett, J; Miller, E; Litwin, M S

    1975-01-01

    It was the purpose of this study to confirm whether the increase in packed cell (PC) viscosity that occurs in humans after elective surgery is accompanied by a decrease in total body O2 consumption as previously noted in animals, and further to define the effect of resolution of intravascular cellular aggregates (ICA) on these parameters. Thirty nine patients were studied. Total body O2 consumption was 76% of normal 6 hours postop, 81% of normal 24 hours postop and 87% of normal 48 hours postop. Twenty four hours after operation PC viscosity and increased markedly. Saline infusion had no significant effect on total body O2 consumption or PC viscosity, either pre- or postop, but WB viscosity decreased linearly in proportion in the drop in hematocrit. Resolution of ICA by dextran-40 infusion was associated with return of total body O2 consumption and PC viscosity to normal; a decrease in WB viscosity was disproportionately greater than would have been seen had the decrease been due solely to the drop in hematocrit. It is concluded that in humans surgical trauma causes an increase in PC viscosity and microcirculatory impairment as evidenced by a decrease in total body O2 consumption. Resolution of ICA by dextran-40 infusion reverses that detrimental changes. PMID:1190882

  2. Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography

    PubMed Central

    Wang, Tianshi; Pfeiffer, Tom; Regar, Evelyn; Wieser, Wolfgang; van Beusekom, Heleen; Lancee, Charles T.; Springeling, Geert; Krabbendam, Ilona; van der Steen, Antonius F.W.; Huber, Robert; van Soest, Gijs

    2015-01-01

    Cardiac motion artifacts, non-uniform rotational distortion and undersampling affect the image quality and the diagnostic impact of intravascular optical coherence tomography (IV-OCT). In this study we demonstrate how these limitations of IV-OCT can be addressed by using an imaging system that we called “Heartbeat OCT”, combining a fast Fourier Domain Mode Locked laser, fast pullback, and a micromotor actuated catheter, designed to examine a coronary vessel in less than one cardiac cycle. We acquired in vivo data sets of two coronary arteries in a porcine heart with both Heartbeat OCT, working at 2.88 MHz A-line rate, 4000 frames/s and 100 mm/s pullback speed, and with a commercial system. The in vivo results show that Heartbeat OCT provides faithfully rendered, motion-artifact free, fully sampled vessel wall architecture, unlike the conventional IV-OCT data. We present the Heartbeat OCT system in full technical detail and discuss the steps needed for clinical translation of the technology. PMID:26713214

  3. Theragnostic ultrasound using microbubbles in the treatment of prostate cancer

    PubMed Central

    2016-01-01

    The use of gas-filled microbubbles in perfusion monitoring as intravascular ultrasound contrast agents has recently become more common. Additionally, microbubbles are employed as carriers of pharmaceutical substances or genes. Microbubbles have great potential to improve the delivery of therapeutic materials into cells and to modify vascular permeability, causing increased extravasation of drugs and drug carriers. Prostate cancer is the most common neoplasm in Europe and America, with an incidence twice to three times that of lung and colorectal cancer. Its incidence is still rising in Asian countries, including Japan and Korea. In this review, we present current strategies regarding the synthesis of microbubbles with targeted ligands on their surfaces, with a focus on prostate cancer. PMID:27197842

  4. Ultrasound skin tightening.

    PubMed

    Minkis, Kira; Alam, Murad

    2014-01-01

    Ultrasound skin tightening is a noninvasive, nonablative method that allows for energy deposition into the deep dermal and subcutaneous tissue while avoiding epidermal heating. Ultrasound coagulation is confined to arrays of 1-mm(3) zones that include the superficial musculoaponeurotic system and connective tissue. This technology gained approval from the Food and Drug Administration as the first energy-based skin "lifting" device, specifically for lifting lax tissue on the neck, submentum, and eyebrows. Ultrasound has the unique advantage of direct visualization of treated structures during treatment. Ultrasound is a safe and efficacious treatment for mild skin tightening and lifting.

  5. Electromagnetically navigated laparoscopic ultrasound.

    PubMed

    Wilheim, Dirk; Feussner, Hubertus; Schneider, Armin; Harms, Jens

    2003-01-01

    A three-dimensional (3D) representation of laparoscopic ultrasound examinations could be helpful in diagnostic and therapeutic laparoscopy, but has not yet been realised with flexible laparoscopic ultrasound probes. Therefore, an electromagnetic navigation system was integrated into the tip of a conventional laparoscopic ultrasound probe. Navigated 3D laparoscopic ultrasound was compared with the imaging data of 3D navigated transcutaneous ultrasound and 3D computed tomography (CT) scan. The 3D CT scan served as the "gold standard". Clinical applicability in standardized operating room (OR) settings, imaging quality, diagnostic potential, and accuracy in volumetric assessment of various well-defined hepatic lesions were analyzed. Navigated 3D laparoscopic ultrasound facilitates exact definition of tumor location and margins. As compared with the "gold standard" of the 3D CT scans, 3D laparoscopic ultrasound has a tendency to underestimate the volume of the region of interest (ROI) (Delta3.1%). A comparison of 3D laparoscopy and transcutaneous 3D ultrasonography demonstrated clearly that the former is more accurate for volumetric assessment of the ROI and facilitates a more detailed display of the lesions. 3D laparoscopic ultrasound imaging with a navigated probe is technically feasible. The technique facilitates detailed ultrasound evaluation of laparoscopic procedures that involve visual, in-depth, and volumetric perception of complex liver pathologies. Navigated 3D laparoscopic ultrasound may have the potential to promote the practical role of laparoscopic ultrasonography, and become a valuable tool for local ablative therapy. In this article, our clinical experiences with a certified prototype of a 3D laparoscopic ultrasound probe, as well as its in vitro and in vivo evaluation, is reported.

  6. HHV-8 and EBV-positive intravascular lymphoma: an unusual presentation of extracavitary primary effusion lymphoma

    PubMed Central

    Crane, Genevieve M.; Ambinder, Richard F.; Shirley, Courtney M.; Fishman, Elliot K.; Kasamon, Yvette L.; Taube, Janis M.; Borowitz, Michael J.; Duffield, Amy S.

    2014-01-01

    Intravascular lymphomas are rare and aggressive hematolymphoid tumors. Here we describe a human herpesvirus type-8/Kaposi sarcoma-associated herpesvirus (HHV-8/KSHV) and Epstein-Barr virus (EBV) positive intravascular lymphoma. The patient was a 59 year-old HIV-positive man who presented with diarrhea, abdominal pain, fevers, night sweats, and weight loss. Radiographic studies of the abdomen and pelvis revealed numerous subcentimeter nodules within the subcutaneous fat that lacked connection to the skin. An excisional biopsy demonstrated large atypical cells within vessels in the deep subcutaneous fat, and many of the vessels contained extensive organizing thrombi. The atypical cells lacked strong expression of most B-cell markers but were positive for MUM-1 and showed partial expression of several T-cell markers. An immunohistochemical stain for HHV-8 and an in situ hybridization for EBV were both positive in the neoplastic cells. The disease had a rapidly progressive and fatal course. This lymphoma appears to represent an entirely intravascular form of primary effusion lymphoma, and highlights the propensity for HHV-8 and EBV-positive lymphoid neoplasms to show aberrant expression of T-cell markers, illustrates the utility of skin biopsies for the diagnosis of intravascular lymphoma, and suggests that biopsies to evaluate for intravascular lymphoma should be relatively deep and include subcutaneous fat. PMID:24525514

  7. Percutaneous Retrieval of Misplaced Intravascular Foreign Objects with the Dormia Basket: An Effective Solution

    SciTech Connect

    Sheth, Rahul Someshwar, Vimal; Warawdekar, Gireesh

    2007-02-15

    Purpose. We report our experience of the retrieval of intravascular foreign body objects by the percutaneous use of the Gemini Dormia basket. Methods. Over a period of 2 years we attempted the percutaneous removal of intravascular foreign bodies in 26 patients. Twenty-six foreign bodies were removed: 8 intravascular stents, 4 embolization coils, 9 guidewires, 1 pacemaker lead, and 4 catheter fragments. The percutaneous retrieval was achieved with a combination of guide catheters and the Gemini Dormia basket. Results. Percutaneous retrieval was successful in 25 of 26 patients (96.2%). It was possible to remove all the intravascular foreign bodies with a combination of guide catheters and the Dormia basket. No complication occurred during the procedure, and no long-term complications were registered during the follow-up period, which ranged from 6 months to 32 months (mean 22.4 months overall). Conclusion. Percutaneous retrieval is an effective and safe technique that should be the first choice for removal of an intravascular foreign body.

  8. Development and evaluation of a novel VEGFR2-targeted nanoscale ultrasound contrast agents

    NASA Astrophysics Data System (ADS)

    Yu, Houqiang; Li, Chunfang; He, Xiaoling; Zhou, Qibing; Ding, Mingyue

    2016-04-01

    Recent literatures have reported that the targeted nanoscale ultrasound contrast agents are becoming more and more important in medical application, like ultrasound imaging, detection of perfusion, drug delivery and molecular imaging and so on. In this study, we fabricated an uniform nanoscale bubbles (257 nm with the polydispersity index of 0.458) by incorporation of antibody targeted to vascular endothelial growth factor receptor 2 (VEGFR2) into the nanobubbles membrane by using avidin-biotin interaction. Some fundamental characterizations such as nanobubble suspension, surface morphology, particle size distribution and zeta potential were investigated. The concentration and time-intensity curves (TICs) were obtained with a self-made ultrasound experimental setup in vitro evaluation. In addition, in order to evaluate the contrast enhancement ability and the potential tumor-targeted ability in vivo, normal Wistar rats and nude female BALB/c mice were intravascular administration of the nanobubbles via tail vein injection, respectively. Significant contrast enhancement of ultrasound imaging within liver and tumor were visualized. These experiments demonstrated that the targeted nanobubbles is efficient in ultrasound molecular imaging by enhancement of the contrast effect and have potential capacity for targeted tumor diagnosis and therapy in the future.

  9. [Ultrasound in East Africa].

    PubMed

    Gysel, W

    2012-09-01

    Ultrasound is poorly established in East Africa because of missing finances and medical staff. The Foundation for medical know how transfer SmW installed in the last 3 years an ultrasound department in all District Hospitals in the South Province Mombasa in Kenya and was teaching the medical staff 2-3 times an year according the guidelines of SGUM and EFSUMB. The project is based on the idea that knowledge transfer is more efficient than money transfer. The project is supervised by public health studies. The first results show that non physicians are able to perform good quality ultrasound examinations. 75% of the obstetrical and 50% of the abdominal ultrasound examinations show therapy-relevant findings. Ultrasound is going to rise to the position of the most important imagine system in developing countries.

  10. [Relationship between the state of intravascular bubbles and microcirculation system].

    PubMed

    Yuan, J; Pan, L; Wang, Q; Ji, Z; Gao, J

    1996-08-01

    To confirm the hypothesis that air bubbles were unable to block the blood vessels and that the state of the intravascular bubbles was determined by the function of the circulatory system, 35 guinea pigs were pressurized then were decompressed to normal pressure. Microscopic observation was made of the bulbar conjunctival, dorsum auricular and subcutaneous vessels in 33 surviving animals. Air bubbles of different amounts, sizes and shapes were found in the dorsum auricular and subcutaneous vein of all the amimals and in the bulbar conjunctival oriridal artery of 16 animals, and in some cases the vessels were even filled with bubbles. The bubbles ran in the same direction and at the same speed as the blood flow. They could run in a backward, to-and-fro or sluggish flow. The bubbles looked shapeless and tended to break and divided into branch flows where the vessel branches. The bubbles were motionless at the proximal end of the artery occluded due to spasm or when the blood was stagnated. Under the action of the blood pressure the bubbles could expand the vessel and push forward. The bubbles showed a tendency of flowing with ease with the function of the vessel recovered. The results suggest that bubbles of any size in the vessel could easily change their shape under the action of the blood flow and pressure, and pass through vessels of any diameter and circulate with the blood. Only when a vessel was occluded due to spasm or the blood in a vessel was stagnated could the bubbles be motionless, but it was not that the bubbles blocked the vessel.

  11. Mechanotransductional basis of endothelial cell response to intravascular bubbles.

    PubMed

    Klinger, Alexandra L; Pichette, Benjamin; Sobolewski, Peter; Eckmann, David M

    2011-10-01

    Vascular air embolism resulting from too rapid decompression is a well-known risk in deep-sea diving, aviation and space travel. It is also a common complication during surgery or other medical procedures when air or other endogenously administered gas is entrained in the circulation. Preventive and post-event treatment options are extremely limited for this dangerous condition, and none of them address the poorly understood pathophysiology of endothelial response to intravascular bubble presence. Using a novel apparatus allowing precise manipulation of microbubbles in real time fluorescence microscopy studies, we directly measure human umbilical vein endothelial cell responses to bubble contact. Strong intracellular calcium transients requiring extracellular calcium are observed upon cell-bubble interaction. The transient is eliminated both by the presence of the stretch activated channel inhibitor, gadolinium, and the transient receptor potential vanilliod family inhibitor, ruthenium red. No bubble induced calcium upsurge occurs if the cells are pretreated with an inhibitor of actin polymerization, cytochalasin-D. This study explores the biomechanical mechanisms at play in bubble interfacial interactions with endothelial surface layer (ESL) macromolecules, reassessing cell response after selective digestion of glycocalyx glycosoaminoglycans, hyaluran (HA) and heparin sulfate (HS). HA digestion causes reduction of cell-bubble adherence and a more rapid induction of calcium influx after contact. HS depletion significantly decreases calcium transient amplitudes, as does pharmacologically induced sydencan ectodomain shedding. The surfactant perfluorocarbon Oxycyte abolishes any bubble induced calcium transient, presumably through direct competition with ESL macromolecules for interfacial occupancy, thus attenuating the interactions that trigger potentially deleterious biochemical pathways.

  12. Supportive management strategies for disseminated intravascular coagulation. An international consensus.

    PubMed

    Squizzato, Alessandro; Hunt, Beverley J; Kinasewitz, Gary T; Wada, Hideo; Ten Cate, Hugo; Thachil, Jecko; Levi, Marcel; Vicente, Vicente; D'Angelo, Armando; Di Nisio, Marcello

    2016-05-01

    The cornerstone of the management of disseminated intravascular coagulation (DIC) is the treatment of the underlying condition triggering the coagulopathy. However, a number of uncertainties remain over the optimal supportive treatment. The aim of this study was to provide evidence and expert-based recommendations on the optimal supportive haemostatic and antithrombotic treatment strategies for patients with DIC. A working group defined five relevant clinical scenarios. Published studies were systematically searched in the MEDLINE and EMBASE databases (up to May 2014). Seven internationally recognised experts were asked to independently provide clinical advice. A two-phase blinded data collection technique was used to reach consensus. Only three randomised controlled trials (RCTs) on the supportive management of DIC were identified. The RCTs (overall less than 100 patients) investigated the use of fresh frozen plasma and platelet transfusion and found no differences in survival between the intervention and control groups. The experts' approach was heterogeneous, although there was consensus that supportive management should vary according to the underlying cause, clinical manifestations and severity of blood test abnormalities. Platelet transfusion should be given to maintain platelet count > 50×10⁹/l in case of bleeding while a lower threshold of 20 to 30×10⁹/l may be used in DIC without bleeding. Thromboprophylaxis with low-molecular-weight heparin is advised until bleeding ensues or platelet count drops below 30×10⁹/l. In conclusion, in the absence of solid evidence from RCTs, an individualised supportive management of DIC is advisable based on the type of underlying disease, presence of bleeding or thrombotic complications and laboratory tests results.

  13. Thromboelastometry in patients with severe sepsis and disseminated intravascular coagulation.

    PubMed

    Sivula, Mirka; Pettilä, Ville; Niemi, Tomi T; Varpula, Marjut; Kuitunen, Anne H

    2009-09-01

    Severe sepsis induces coagulopathy, which may lead to disseminated intravascular coagulation (DIC). Thromboelastometry is a point-of-care whole blood coagulation monitor, which has been validated in human endotoxemia model. We assessed thromboelastometry in severe sepsis and overt DIC and investigated its applicability in differentiating sepsis-related coagulation disturbances. Thromboelastometry (EXTEM and FIBTEM tests) and traditional coagulation assays were analyzed in 28 patients with severe sepsis, 12 of who fulfilled the criteria of overt DIC on admission. Ten healthy persons served as controls. Coagulation parameters, clotting time, clot formation time (CFT), alpha angle, maximal clot firmness (MCF) and lysis index at 60 min, were registered. In patients with overt DIC, EXTEM MCF, CFT and alpha angle differed from that in both healthy controls and patients without DIC, indicating hypocoagulation (MCF 52, 63 and 68 mm; CFT 184, 88 and 73 s; and alpha angle 58, 72 and 76 degrees , respectively, P < 0.01 for all). In patients without DIC, the trend was toward hypercoagulation in EXTEM and FIBTEM MCF (68 vs. 63 mm, P = 0.042 and 23 vs. 15 mm, P = 0.034, respectively). Receiver operating characteristic curves showed that MCF, CFT and alpha angle discriminated patients with overt DIC moderately (area under curve 0.891, 0.815 and 0.828, respectively, P < 0.001 for all). Traditional coagulation assays showed progressively worsening coagulopathy from controls to septic patients without DIC and further to those with overt DIC. We conclude that thromboelastometry may be a valuable tool in assessing whole blood coagulation capacity in patients with severe sepsis with and without overt DIC.

  14. Ultrasound imaging during pregnancy.

    PubMed

    Gold, R B

    1984-01-01

    Review by a panel of experts convened by the National Institute of Health (NIH) and the Federal Food and Drug Administration (FDA) resulted in a recommendation for diagnostic ultrasound imaging in about 1/3 of pregnancies only when medically indicated but not routinely. Ultrasound technology, 1st developed for use in submarine warfare sonar devices, is widely used by physicians because of its clinical significance and because it allows seeing intrauterine structures without exposing the fetus to dangerous radiation. Its most important uses include estimating the gestational age for patients with uncertain clinical dates, evaluating fetal growth, determining the cause of vaginal bleeding, determining fetal presentation, identifying multiple gestation, supplementing amniocentesis or other special procedures, diagnosing, confirming fetal death and locating intrauterine devices. Recently, many physicians have been advocating routine ultrasound screening of all pregnancies but this is an issue of concern among leading physicians and the NIH. The panel stressed the urgent need for additional research on the safety and efficacy of the procedure. Many studies that found adverse reactions associated with ultrasound use in humans suffer from sever methodological flaws. The panel recommended ultrasound not to be used for routine screening. Some studies indicate that no clear benefit from routine screening results. The panel's recommendations were criticized for unnecessarily restricting ultrasound use and for inappropriately sanctioning widespread use of the technology. Human Life International, an anti-abortion organization, opposed using ultrasound to detect fetal abnormalities, contending that this would promote abortion. Some abortion opponents, however, believe ultrasound would cause bonding between the mother and the fetus and discourage abortion. The panel underscored the importance of the skill and training of ultrasound examiners. In regard to informed consent, the

  15. High-sensitivity intravascular photoacoustic imaging of lipid–laden plaque with a collinear catheter design

    PubMed Central

    Cao, Yingchun; Hui, Jie; Kole, Ayeeshik; Wang, Pu; Yu, Qianhuan; Chen, Weibiao; Sturek, Michael; Cheng, Ji-Xin

    2016-01-01

    A highly sensitive catheter probe is critical to catheter-based intravascular photoacoustic imaging. Here, we present a photoacoustic catheter probe design on the basis of collinear alignment of the incident optical wave and the photoacoustically generated sound wave within a miniature catheter housing for the first time. Such collinear catheter design with an outer diameter of 1.6 mm provided highly efficient overlap between optical and acoustic waves over an imaging depth of >6 mm in D2O medium. Intravascular photoacoustic imaging of lipid-laden atherosclerotic plaque and perivascular fat was demonstrated, where a lab-built 500 Hz optical parametric oscillator outputting nanosecond optical pulses at a wavelength of 1.7 μm was used for overtone excitation of C-H bonds. In addition to intravascular imaging, the presented catheter design will benefit other photoacoustic applications such as needle-based intramuscular imaging. PMID:27121894

  16. High-sensitivity intravascular photoacoustic imaging of lipid-laden plaque with a collinear catheter design.

    PubMed

    Cao, Yingchun; Hui, Jie; Kole, Ayeeshik; Wang, Pu; Yu, Qianhuan; Chen, Weibiao; Sturek, Michael; Cheng, Ji-Xin

    2016-01-01

    A highly sensitive catheter probe is critical to catheter-based intravascular photoacoustic imaging. Here, we present a photoacoustic catheter probe design on the basis of collinear alignment of the incident optical wave and the photoacoustically generated sound wave within a miniature catheter housing for the first time. Such collinear catheter design with an outer diameter of 1.6 mm provided highly efficient overlap between optical and acoustic waves over an imaging depth of >6 mm in D2O medium. Intravascular photoacoustic imaging of lipid-laden atherosclerotic plaque and perivascular fat was demonstrated, where a lab-built 500 Hz optical parametric oscillator outputting nanosecond optical pulses at a wavelength of 1.7 μm was used for overtone excitation of C-H bonds. In addition to intravascular imaging, the presented catheter design will benefit other photoacoustic applications such as needle-based intramuscular imaging. PMID:27121894

  17. Changes in morphology and permeability of perfused rabbit arteries during acute elevation of the intravascular pressure

    SciTech Connect

    Voino-Yasenetskaya, T.A.; Skuratovskaya, L.N.

    1986-12-01

    This paper presents a study on whether a short-term increase of intravascular pressure causes morphological injuries to the endothelium or accelerates the accumulation of /sup 125/I-labeled low-density lipoproteins (/sup 125/I-LDL) in the wall of perfused arteries of healthy rabbits, and how a raised hydrostatic pressure affects /sup 125/I-LDL transport in denuded areas of perfused arteries. The average number of cells per 1 mm/sup 2/ of luminal surface during perfusion under a pressure of 100-250 mm Hg is shown. Also, the morphology of endothelial lining of rabbit aorta under increased intravascular pressure is presented, as is the incorporation of /sup 125/I-LDL into wall of rabbit aorta under increased intravascular pressure.

  18. In Vivo Assessment of Pulmonary Arterial Wall Fibrosis by Intravascular Optical Coherence Tomography in Pulmonary Arterial Hypertension: A New Prognostic Marker of Adverse Clinical Follow-Up§

    PubMed Central

    Domingo, Enric; Grignola, Juan C; Aguilar, Rio; Montero, María Angeles; Arredondo, Christian; Vázquez, Manuel; López-Messeguer, Manuel; Bravo, Carlos; Bouteldja, Nadia; Hidalgo, Cristina; Roman, Antonio

    2013-01-01

    Background: The aim is to correlate pulmonary arterial (PA) remodeling estimated by PA fibrosis in PA hypertension (PAH) with clinical follow-up. Histology of PA specimens is also performed. Methods: 19 patients, aged 54±16 (4 men), functional class II-III were studied with right heart catheterization, PA Intravascular Ultrasound and optical coherence tomography (OCT) in inferior lobe segment. PA wall fibrosis was obtained by OCT ( area of fibrosis/PA cross sectional area × 100). Patients follow-up was blind to OCT. Events were defined as mortality, lung transplantation, need of intravenous prostaglandins or onset of right ventricular failure. Results: OCT measurements showed high intra- and interobserver agreement. There was a good correlation between OCT and histology in PA fibrosis from explanted lungs. Area of fibrosis was 1.4±0.8 mm2, % fibrosis was 22.3±8. Follow-up was 3.5 years (2.5-4.5). OCT %Fib was significantly correlated with PA capacitance (r=-0.536) and with pulmonary vascular rsistance (r=0.55). Patients were divided according to the median value of PA fibrosis. There were 10 patients with a high (≥ 22%) and 9 with a low fibrosis (<22%). Events occurred in 6 (1 death, 1 lung transplantation, 2 intravenous prostaglandins, 2 right heart failure) out of 10 patients with high and in 0 out of 9 patients with low fibrosis (p<0.01). Conclusions: In PAH, the severity of PA remodeling assessed by OCT wall fibrosis was significantly predictive of severely unfavorable clinical outcome. In vivo assessment of pulmonary arterial wall fibrosis by intravascular OCT in PAH is a promising new prognostic marker of adverse clinical outcome. PMID:23730366

  19. Chronic biliary obstruction induces pulmonary intravascular phagocytosis and endotoxin sensitivity in rats.

    PubMed Central

    Chang, S W; Ohara, N

    1994-01-01

    Endotoxin sensitivity varies among animal species and appears to correlate with the presence of pulmonary intravascular macrophage (PIM). In rats, which lack PIM, we investigated the hypothesis that chronic cholestatic liver injury leads to induction of PIM and endotoxin sensitivity. Rats were randomized to either common bile duct ligation (BDL) or sham-surgery and studied at 1 wk (acute cholestasis), 2 wk (cholestasis, early cirrhosis), and 4 wk (cholestasis, established cirrhosis) after surgery. Intravascularly injected fluorescent latex microspheres (1 micron diameter) were taken up by large phagocytic cells in lung parenchyma of BDL rats (at 2 and 4 wk), while no uptake was observed in lungs from control rats. Electronmicroscopy revealed accumulation of large, mononuclear, macrophage-like cells containing ingested latex particles within the pulmonary capillaries. Pulmonary intravascular phagocytosis, as reflected in lung uptake of 99mTc microaggregated albumin (Microlite, mean particle diameter = 1 micron), averaged 0.7 +/- 0.1% (mean +/- SEM) of total injected dose in 13 control rats and progressively increased with time after BDL (1 wk, 1.7 +/- 0.2%; 2 wk, 10.0 +/- 3.0%; 4 wk 35.1 +/- 5.9%). Rats with biliary cirrhosis were markedly sensitive to the lethal effects of low dose endotoxin and demonstrated marked lung edema at the time of death. Furthermore, the lung uptake of intravascular 125I-lipopolysaccharide was increased five-fold in cirrhotic rats. We conclude that chronic biliary obstruction leads to the induction of pulmonary intravascular phagocytes and enhances endotoxin sensitivity in rats. Pulmonary intravascular phagocytosis in patients with advanced cirrhosis may account for their increased susceptibility to sepsis-induced adult respiratory distress syndrome. Images PMID:7962547

  20. Leiomyosarcoma of the Uterus with Intravascular Tumor Extension and Pulmonary Tumor Embolism

    SciTech Connect

    McDonald, Douglas K.; Kalva, Sanjeeva P. Fan, C.-M.; Vasilyev, Aleksandr

    2007-02-15

    We report the case of a 48-year-old woman presenting with recurrent uterine leiomyosarcoma (LMS) associated with right iliac vein and inferior vena cava (IVC) invasion and left lower lobe pulmonary tumor embolus. Because the prognosis and treatment differ from that of thrombotic pulmonary emboli, the differentiating imaging characteristics of intravascular tumor embolism are reviewed. To our knowledge, only two other cases of intravenous uterine leiomyosarcomatosis have been described in the existing literature, and this is the first reported case of the entity with associated intravascular tumor embolism.

  1. Endobronchial ultrasound-guided transbronchial needle aspiration of pulmonary artery tumors: A systematic review (with video).

    PubMed

    Harris, Kassem; Modi, Kush; Kumar, Abhishek; Dhillon, Samjot Singh

    2015-01-01

    Convex probe endobronchial ultrasound (CP-EBUS) was originally introduced as a diagnostic and staging tool for lung cancer and subsequently utilized for diagnosis of other malignant and benign mediastinal diseases such as melanoma, lymphoma, and sarcoidosis. More recently, CP-EBUS has been successfully used for the visualization and diagnosis of pulmonary emboli and other vascular lesions including primary and metastatic pulmonary artery (PA) tumors. In this review, we will underline the role of EBUS-guided transbronchial needle aspiration (EBUS-TBNA) for the diagnosis of pulmonary arterial tumors such as sarcomas and tumor emboli. We will concisely discuss the clinical applications of EBUS-TBNA and the types of pulmonary arterial tumors and their different diagnostic modalities. We searched the Cochrane Library and PubMed from 2004 to 2014 to provide the most comprehensive review. Only 10 cases of EBUS-TBNA for intravascular lesions were identified in the literature. Although many cases of EBUS and EUS-guided transvascular tumor biopsies were described in the literature, there were no reported cases of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for intravascular tumor biopsies. Except for one paper, all cases were published as case reports. PMID:26374576

  2. High intensity ultrasound.

    PubMed

    ter Haar, G

    2001-03-01

    High-intensity focused ultrasound (HIFU) is a technique that was first investigated in the 1940s as a method of destroying selective regions within the brain in neuro-surgical An ultrasound beam can be brought to a tight focus at a distance from its source, and if sufficient energy is concentrated within the focus, the cells lying within this focal volume are killed, whereas those lying elsewhere are spared. This is a noninvasive method of producing selective and trackless tissue destruction in deep seated targets in the body, without damage to overlying tissues. This field, known both as HIFU and focused ultrasound surgery (FUS), is reviewed in this article.

  3. Ethics of prenatal ultrasound.

    PubMed

    Howe, David

    2014-04-01

    Prenatal ultrasound has opened new opportunities to examine, diagnose and treat the fetus, but these advances bring with them ethical dilemmas. In this chapter, I address the ethical principles that need to be considered when treating both mother and fetus as patients, and how these can be applied in practice. In particular, ultrasound practitioners have an ethical duty to maintain their theoretical knowledge and practical skills to ensure they advise parents correctly. I also discuss the ethical issues in carrying out intrauterine therapy, ultrasound-related research, and termination of pregnancy for fetal abnormality.

  4. Ultrasound assessment of schistosomiasis.

    PubMed

    Richter, J; Botelho, M C; Holtfreter, M C; Akpata, R; El Scheich, T; Neumayr, A; Brunetti, E; Hatz, C; Dong, Y; Dietrich, C F

    2016-07-01

    In 2000, the World Health Organization (WHO) issued an ultrasound field protocol for assessing the morbidity due to Schistosoma (S.) haematobium and S. mansoni. The experience with this classification has recently been reviewed systematically. The WHO protocol was well accepted worldwide. Here we review the use of ultrasound to assess the morbidity due to schistosomiasis with emphasis on easy, quick, and reproducible ways that can be used in the field. Findings obtained with high-end ultrasound scanners in the hospital setting that might eventually have applications in the field are also described. PMID:27429103

  5. Bedside ocular ultrasound.

    PubMed

    Roque, Pedro J; Hatch, Nicholas; Barr, Laurel; Wu, Teresa S

    2014-04-01

    Many ocular emergencies are difficult to diagnose in the emergency setting with conventional physical examination tools. Additionally, persistent efforts to re-examine the eye may be deleterious to a patient's overall condition. Ultrasound is an important tool because it affords physicians a rapid, portable, accurate, and dynamic tool for evaluation of a variety of ocular and orbital diseases. The importance of understanding orbital anatomy, with attention to the firm attachment points of the various layers of the eye, cannot be understated. This article describes the relevant eye anatomy, delves into the ultrasound technique, and illustrates a variety of orbital pathologies detectable by bedside ultrasound.

  6. IMPACT OF OBESITY ON ENDOTOXIN-INDUCED DISSEMINATED INTRAVASCULAR COAGULATION.

    PubMed

    Duburcq, Thibault; Tournoys, Antoine; Gnemmi, Viviane; Hubert, Thomas; Gmyr, Valery; Pattou, François; Jourdain, Mercé

    2015-10-01

    An early activation of coagulation and fibrinolysis occurs during sepsis, leading to the syndrome of disseminated intravascular coagulation (DIC). Obesity has been demonstrated to be a hypercoagulable and hypofibrinolytic state, but its impact on DIC has never been studied. In this study, we aimed to determine if obesity impairs DIC in an acute endotoxic shock model using minipigs. This was a prospective, comparative, and experimental ancillary study approved by the Animal Ethics Committee. Pigs were chosen as a clinically relevant species, resembling humans in coagulation reactions. Four groups of five "Yucatan" minipigs were studied: lean and obese control groups, a lean lipopolysaccharide (LPS) group receiving Escherichia coli endotoxin (LPS), and an obese LPS group receiving the same endotoxin dose. We measured standard coagulation parameters (prothrombin time [PT], platelet count, and fibrinogen levels), thrombin-antithrombin complexes, tissue-type plasminogen activator, and plasminogen activator inhibitor-1. All measurements were performed at baseline and 30, 60, 90, 150, and 300 min. Results were given as median with interquartile ranges. At baseline, platelet count (477 [428 - 532] G/L vs. 381 [307 - 442] G/L; P = 0.005) and fibrinogen levels (4.6 [3.8 - 5.2] g/L vs. 2 [1.8 - 2.9] g/L; P < 0.001) were significantly higher, whereas PT (80% [76% - 92%] vs. 96% [89% - 100%]; P = 0.01) was significantly lower in obese pigs compared with lean pigs. In the LPS groups, administration of endotoxin resulted in a typical hypokinetic shock with DIC. The decrease in coagulation parameters (PT, platelet count, and fibrinogen levels) and the increase in thrombin-antithrombin complexes (581 [382 - 1,057] μg/mL vs. 247 [125 - 369] μg/mL at 150 min; P = 0.03) were significantly more important in the obese LPS group compared with those in the lean LPS group. Concerning the fibrinolytic reaction, we found a slightly more elevated increase of plasminogen

  7. Meta-analysis on intravascular low energy laser therapy

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Dong; Liu, Timon Cheng-Yi; Wang, Yan-Fang; Liu, Song-Hao

    2008-12-01

    Intravascular low energy laser therapy (ILELT) was put forward for cardiocirculatory diseases in USA in 1982, was popular in Russia in 1980s, and then in China in 1990s. The therapeutic effects of ILELT and drugs in comparison with drugs only on Chinese patients and their blood parameters were analyzed with meta-analyses and reported as (OR, 95%CI) for patient improvement and (WMD, 95% CI) for blood parameter improvement, where 95%CI, OR and WMD denoted 95% confidence intervals, odds ratio and weighted mean difference, respectively. It was found that the patients of cerebral infarction (2.39, 2.09~2.74) and cerebrovascular diseases (2.97, 1.69~2.53) were cured, respectively, (P < 0.01), and the symptom improvement of patients of cerebral infarction, cerebrovascular diseases and diabetes were significant (3.13, 2.79~3.51), (4.92, 3.39~7.14) , and (3.80, 2.79~5.18), and mild (3.66, 3.15~4.24), (4.95, 2.77~8.84), and (7.11, 4.54~11.13), respectively, (P < 0.01). It was also found that the blood parameters such as cholesterol (-0.78, -1.32~-0.24), total cholesterol (-1.08, -1.80~-0.36), low density lipoprotein cholesterol (-0.6, -1.01~-0.19), triacylglycerol (0.63, -0.83~-0.42), high density lipoprotein (0.34, 0.10~0.59), erythrocyte aggregation index (-0.24, -0.27~-0.21), erythrocyte Sedimentation Rate (-4.57, -7.26~-1.89), fibrinogen (-0.76, -1.31~-0.21), whole blood contrast viscosity (-0.40, -0.69~-0.12), low cut blood viscosity (-1.2, -1.93~-0.48), high cut blood viscosity (-0.62, -0.92~-0.32), whole blood viscosity(-1.2, -1.85~-0.54) and plasma blood contrast viscosity(-0.07, -0.12~-0.03) were found improved (P < 0.05). It is concluded that the patients of cerebral infarction, cerebrovascular diseases and diabetes might be improved with ILELT, which might be mediated by blood parameter improvement.

  8. Ultrasound in pregnancy (image)

    MedlinePlus

    The ultrasound has become a standard procedure used during pregnancy. It can demonstrate fetal growth and can detect increasing ... abnormalities, hydrocephalus, anencephaly, club feet, and other ... does not produce ionizing radiation and is considered ...

  9. General Ultrasound Imaging

    MedlinePlus

    ... collects the sounds that bounce back and a computer then uses those sound waves to create an ... types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements into an array of ...

  10. Ultrasound: Pelvis (For Parents)

    MedlinePlus

    ... pelvic area and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  11. Ultrasound: Infant Hip

    MedlinePlus

    ... hip area, and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  12. Ultrasound: Abdomen (For Parents)

    MedlinePlus

    ... abdominal area and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  13. Ultrasound: Head (For Parents)

    MedlinePlus

    ... the head and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  14. Ultrasound: Bladder (For Parents)

    MedlinePlus

    ... bladder area and images are recorded on a computer. The black-and-white images show the internal ... the images can be seen clearly on the computer screen. A technician (sonographer) trained in ultrasound imaging ...

  15. Evolution of contrast agents for ultrasound imaging and ultrasound-mediated drug delivery

    PubMed Central

    Paefgen, Vera; Doleschel, Dennis; Kiessling, Fabian

    2015-01-01

    Ultrasound (US) is one of the most frequently used diagnostic methods. It is a non-invasive, comparably inexpensive imaging method with a broad spectrum of applications, which can be increased even more by using bubbles as contrast agents (CAs). There are various different types of bubbles: filled with different gases, composed of soft- or hard-shell materials, and ranging in size from nano- to micrometers. These intravascular CAs enable functional analyses, e.g., to acquire organ perfusion in real-time. Molecular analyses are achieved by coupling specific ligands to the bubbles’ shell, which bind to marker molecules in the area of interest. Bubbles can also be loaded with or attached to drugs, peptides or genes and can be destroyed by US pulses to locally release the entrapped agent. Recent studies show that US CAs are also valuable tools in hyperthermia-induced ablation therapy of tumors, or can increase cellular uptake of locally released drugs by enhancing membrane permeability. This review summarizes important steps in the development of US CAs and introduces the current clinical applications of contrast-enhanced US. Additionally, an overview of the recent developments in US probe design for functional and molecular diagnosis as well as for drug delivery is given. PMID:26441654

  16. Ultrasound in perinatology

    SciTech Connect

    Maklad, N.F.

    1986-01-01

    This 19th volume in the series Clinics in Diagnostic Ultrasound provides an overview and update of some of the recent applications of ultrasound (US) in the pernatal period. Prenatal topics include estimation of gestational age; evaluation of intrauterine growth retardation, non-immune hydrops, and fetal urinary abnormalities; fetal echocardiography; and biophysical scoring. The discussion of postnatal topics includes US studies of the head and abdomen, echocardiography, and interventional procedures.

  17. What is ultrasound?

    PubMed

    Leighton, Timothy G

    2007-01-01

    This paper is based on material presented at the start of a Health Protection Agency meeting on ultrasound and infrasound. In answering the question 'what is ultrasound?', it shows that the simple description of a wave which transports mechanical energy through the local vibration of particles at frequencies of 20 kHz or more, with no net transport of the particles themselves, can in every respect be misleading or even incorrect. To explain the complexities responsible for this, the description of ultrasound is first built up from the fundamental properties of these local particle vibrations. This progresses through an exposition of the characteristics of linear waves, in order to explain the propensity for, and properties of, the nonlinear propagation which occurs in many practical ultrasonic fields. Given the Health Protection environment which framed the original presentation, explanation and examples are given of how these complexities affect issues of practical importance. These issues include the measurement and description of fields and exposures, and the ability of ultrasound to affect tissue (through microstreaming, streaming, cavitation, heating, etc.). It is noted that there are two very distinct regimes, in terms of wave characteristics and potential for bioeffect. The first concerns the use of ultrasound in liquids/solids, for measurement or material processing. For biomedical applications (where these two processes are termed diagnosis and therapy, respectively), the issue of hazard has been studied in depth, although this has not been done to such a degree for industrial uses of ultrasound in liquids/solids (sonar, non-destructive testing, ultrasonic processing etc.). However, in the second regime, that of the use of ultrasound in air, although the waves in question tend to be of much lower intensities than those used in liquids/solids, there is a greater mismatch between the extent to which hazard has been studied, and the growth in commercial

  18. Focused ultrasound in ophthalmology

    PubMed Central

    Silverman, Ronald H

    2016-01-01

    The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via ciliodestruction), tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities. PMID:27757007

  19. [Ultrasound imaging in laryngology].

    PubMed

    Zajkowski, Piotr; Białek, Ewa J

    2007-01-01

    Modern ultrasound with high resolution transducers, and sensitive power Doppler and color Doppler modes, and other options, such as panoramic and 3D imaging, allows for detailed imaging of many anatomical structures and pathologic lesions of the head and neck. Only the structures situated in the sonographic acoustic shadow: behind bones, calcified cartilages, stones, and behind organs containing gas (f.e. trachea and larynx) can not be visualized. Ultrasound is widely regarded as the first imaging method in the diseases of the thyroid, salivary glands (parotid gland, submandibular gland and sublingual gland), lymph nodes, muscles, soft tissues of the head and neck, and as an valuable adjunct in some laryngeal pathologies. Real time ultrasound examination allows for dynamic assessment of organs and lesions, lets the examiner check the susceptibility of tumors for pressure, which is inaccessible in other imaging methods. Tumors and congenital lesions, inflammation, abscesses, abnormal lymph nodes, cysts, muscle hypertrophy and posttraumatic conditions may be well evaluated with ultrasound. However, most neck tumors (f.e. in the thyroid, salivary glands, and soft tisses) as well as equivocal lymph nodes demand fine needle aspiration biopsy to determine their benign or malignant nature. This paper presents application of ultrasound examination in the head and neck area including limitations of ultrasound diagnostics in many clinical cases. Data taken from Polish and foreign literature and author's experience are included in this paper.

  20. 21 CFR 880.5965 - Subcutaneous, implanted, intravascular infusion port and catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... port and catheter. 880.5965 Section 880.5965 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... port and catheter. (a) Identification. A subcutaneous, implanted, intravascular infusion port and... catheter is either preattached to the port or attached to the port at the time of device placement....

  1. Microfluidics in the Undergraduate Laboratory: Device Fabrication and an Experiment to Mimic Intravascular Gas Embolism

    ERIC Educational Resources Information Center

    Jablonski, Erin L.; Vogel, Brandon M.; Cavanagh, Daniel P.; Beers, Kathryn L.

    2010-01-01

    A method to fabricate microfluidic devices and an experimental protocol to model intravascular gas embolism for undergraduate laboratories are presented. The fabrication process details how to produce masters on glass slides; these masters serve as molds to pattern channels in an elastomeric polymer that can be adhered to a substrate, resulting in…

  2. Research of epidermal cellular vegetal cycle of intravascular low level laser irradiation in treatment of psoriasis

    NASA Astrophysics Data System (ADS)

    Zhu, Jing; Bao, Xiaoqing; Zhang, Mei-Jue

    2005-07-01

    Objective: To research epidermal cellular vegetal cycle and the difference of DNA content between pre and post Intravascular Low Level Laser Irradiation treatment of psoriasis. Method: 15 patients suffered from psoriasis were treated by intravascular low level laser irradiation (output power: 4-5mw, 1 hour per day, a course of treatment is 10 days). We checked the different DNA content of epidermal cell between pre and post treatment of psoriasis and 8 natural human. Then the percentage of each phase among the whole cellular cycle was calculated and the statistical analysis was made. Results: The mean value of G1/S phase is obviously down while G2+M phase increased obviously. T test P<0.05.The related statistical analysis showed significant difference between pre and post treatments. Conclusions: The Intravascular Low Level Laser Irradiation (ILLLI) in treatment of psoriasis is effective according to the research of epidermal cellular vegetal cycle and the difference DNA content of Intravascular Low Level Laser Irradiation between pre and post treatment of psoriasis

  3. [Rhabdomyolysis, disseminated intravascular coagulation and multiple organ failure in a patient with cocaine and heroine poisoning].

    PubMed

    Vreugdenhil, G; Ligthart, J; de Leeuw, P W

    1992-06-20

    A 19-year-old female patient with cocaine and heroin intoxication is described in whom several life threatening complications such as hypovolemic shock, cardiopulmonary insufficiency, rhabdomyolysis, diffuse intravascular coagulation and multiple organ failure occurred. The patient survived the intoxication after quick intensive treatment.

  4. Radiological imaging of florid intravascular papillary endothelial hyperplasia in the mandibule: case report and literature review.

    PubMed

    Xu, Sheng-Sheng; Li, Dan

    2014-01-01

    Intravascular papillary endothelial hyperplasia was a rare benign vascular proliferative process as a result of papillary proliferation of the endothelial cells within the vessels. To our knowledge, we reported the second case occurring in the madibule, and the first reported in 1984 in the literature. We discussed manifestations of multislice computed tomography and panoramic radiography about the lesion and relevant literature was reviewed.

  5. Evaluation of Intravascular Hemolysis With Erythrocyte Creatine in Patients With Aortic Stenosis.

    PubMed

    Sugiura, Tetsuro; Okumiya, Toshika; Kubo, Toru; Takeuchi, Hiroaki; Matsumura, Yoshihisa

    2016-07-27

    Chronic intravascular hemolysis has been identified in patients with cardiac valve prostheses, but only a few case reports have evaluated intravascular hemolysis in patients with native valvular heart disease. To detect intravascular hemolysis in patients with aortic stenosis, erythrocyte creatine was evaluated with hemodynamic indices obtained by echocardiography.Erythrocyte creatine, a marker of erythrocyte age, was assayed in 30 patients with aortic stenosis and 10 aged matched healthy volunteers. Peak flow velocity of the aortic valve was determined by continuous-wave Doppler echocardiography. Twenty of 30 patients with aortic stenosis had high erythrocyte creatine levels (> 1.8 µmol/g Hb) and erythrocyte creatine was significantly higher as compared with control subjects (1.98 ± 0.49 versus 1.52 ± 0.19 µmol/g Hb, P = 0.007). Peak transvalvular pressure gradient ranged from 46 to 142 mmHg and peak flow velocity ranged from 3.40 to 5.95 m/second. Patients with aortic stenosis had a significantly lower erythrocyte count (387 ± 40 versus 436 ± 42 × 10(4) µL, P = 0.002) and hemoglobin (119 ± 11 versus 135 ± 11 g/L, P < 0.001) as compared with control subjects. Erythrocyte creatine had a fair correlation with peak flow velocity (r = 0.55, P = 0.002).In conclusion, intravascular hemolysis due to destruction of erythrocytes was detected in patients with moderate to severe aortic stenosis and the severity of intravascular hemolysis was related to valvular flow velocity of the aortic valve.

  6. Asphyxia by Drowning Induces Massive Bleeding Due To Hyperfibrinolytic Disseminated Intravascular Coagulation

    PubMed Central

    Schwameis, Michael; Schober, Andreas; Schörgenhofer, Christian; Sperr, Wolfgang Reinhard; Schöchl, Herbert; Janata-Schwatczek, Karin; Kürkciyan, Erol Istepan; Sterz, Fritz

    2015-01-01

    Objective: To date, no study has systematically investigated the impact of drowning-induced asphyxia on hemostasis. Our objective was to test the hypothesis that asphyxia induces bleeding by hyperfibrinolytic disseminated intravascular coagulation. Design: Observational study. Setting: A 2,100-bed tertiary care facility in Vienna, Austria, Europe. Patients: All cases of drowning-induced asphyxia (n = 49) were compared with other patients with cardiopulmonary resuscitation (n = 116) and to patients with acute promyelocytic leukemia (n = 83). Six drowning victims were investigated prospectively. To study the mechanism, a forearm-ischemia model was used in 20 volunteers to investigate whether hypoxia releases tissue plasminogen activator. Interventions: None. Measurements and Main Results: Eighty percent of patients with drowning-induced asphyxia developed overt disseminated intravascular coagulation within 24 hours. When compared with nondrowning cardiac arrest patients, drowning patients had a 13 times higher prevalence of overt disseminated intravascular coagulation at admission (55% vs 4%; p < 0.001). Despite comparable disseminated intravascular coagulation scores, acute promyelocytic leukemia patients had higher fibrinogen but lower d-dimer levels and platelet counts than drowning patients (p < 0.001). Drowning victims had a three-fold longer activated partial thromboplastin time (124 s; p < 0.001) than both nondrowning cardiac arrest and acute promyelocytic leukemia patients. Hyperfibrinolysis was reflected by up to 1,000-fold increased d-dimer levels, greater than 5-fold elevated plasmin antiplasmin levels, and a complete absence of thrombelastometric clotting patterns, which was reversed by antifibrinolytics and heparinase. Thirty minutes of forearm-ischemia increased tissue plasminogen activator 31-fold (p < 0.001). Conclusions: The vast majority of drowning patients develops overt hyperfibrinolytic disseminated intravascular coagulation, partly caused by

  7. Intravascular pressure augments cerebral arterial constriction by inducing voltage-insensitive Ca2+ waves.

    PubMed

    Mufti, Rania E; Brett, Suzanne E; Tran, Cam Ha T; Abd El-Rahman, Rasha; Anfinogenova, Yana; El-Yazbi, Ahmed; Cole, William C; Jones, Peter P; Chen, S R Wayne; Welsh, Donald G

    2010-10-15

    This study examined whether elevated intravascular pressure stimulates asynchronous Ca(2+) waves in cerebral arterial smooth muscle cells and if their generation contributes to myogenic tone development. The endothelium was removed from rat cerebral arteries, which were then mounted in an arteriograph, pressurized (20-100 mmHg) and examined under a variety of experimental conditions. Diameter and membrane potential (V(M)) were monitored using conventional techniques; Ca(2+) wave generation and myosin light chain (MLC(20))/MYPT1 (myosin phosphatase targeting subunit) phosphorylation were assessed by confocal microscopy and Western blot analysis, respectively. Elevating intravascular pressure increased the proportion of smooth muscle cells firing asynchronous Ca(2+) waves as well as event frequency. Ca(2+) wave augmentation occurred primarily at lower intravascular pressures (<60 mmHg) and ryanodine, a plant alkaloid that depletes the sarcoplasmic reticulum (SR) of Ca(2+), eliminated these events. Ca(2+) wave generation was voltage insensitive as Ca(2+) channel blockade and perturbations in extracellular [K(+)] had little effect on measured parameters. Ryanodine-induced inhibition of Ca(2+) waves attenuated myogenic tone and MLC(20) phosphorylation without altering arterial V(M). Thapsigargin, an SR Ca(2+)-ATPase inhibitor also attenuated Ca(2+) waves, pressure-induced constriction and MLC(20) phosphorylation. The SR-driven component of the myogenic response was proportionally greater at lower intravascular pressures and subsequent MYPT1 phosphorylation measures revealed that SR Ca(2+) waves facilitated pressure-induced MLC(20) phosphorylation through mechanisms that include myosin light chain phosphatase inhibition. Cumulatively, our findings show that mechanical stimuli augment Ca(2+) wave generation in arterial smooth muscle and that these transient events facilitate tone development particularly at lower intravascular pressures by providing a proportion of the Ca

  8. AMUM LECTURE: Therapeutic ultrasound

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence A.

    2004-01-01

    The use of ultrasound in medicine is now quite commonplace, especially with the recent introduction of small, portable and relatively inexpensive, hand-held diagnostic imaging devices. Moreover, ultrasound has expanded beyond the imaging realm, with methods and applications extending to novel therapeutic and surgical uses. These applications broadly include: tissue ablation, acoustocautery, lipoplasty, site-specific and ultrasound mediated drug activity, extracorporeal lithotripsy, and the enhancement of natural physiological functions such as wound healing and tissue regeneration. A particularly attractive aspect of this technology is that diagnostic and therapeutic systems can be combined to produce totally non-invasive, imageguided therapy. This general lecture will review a number of these exciting new applications of ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of High Intensity Focused Ultrasound (HIFU) in the treatment of benign and malignant tumors as well as the introduction of acoustic hemostasis, especially in organs which are difficult to treat using conventional medical and surgical techniques.

  9. All-Optical Ultrasound Transducers for High Resolution Imaging

    NASA Astrophysics Data System (ADS)

    Sheaff, Clay Smith

    High frequency ultrasound (HFUS) has increasingly been used within the past few decades to provide high resolution (< 200 mum) imaging in medical applications such as endoluminal imaging, intravascular imaging, ophthalmology, and dermatology. The optical detection and generation of HFUS using thin films offers numerous advantages over traditional piezoelectric technology. Circumvention of an electronic interface with the device head is one of the most significant given the RF noise, crosstalk, and reduced capacitance that encumbers small-scale electronic transducers. Thin film Fabry-Perot interferometers - also known as etalons - are well suited for HFUS receivers on account of their high sensitivity, wide bandwidth, and ease of fabrication. In addition, thin films can be used to generate HFUS when irradiated with optical pulses - a method referred to as Thermoelastic Ultrasound Generation (TUG). By integrating a polyimide (PI) film for TUG into an etalon receiver, we have created for the first time an all-optical ultrasound transducer that is both thermally stable and capable of forming fully sampled 2-D imaging arrays of arbitrary configuration. Here we report (1) the design and fabrication of PI-etalon transducers; (2) an evaluation of their optical and acoustic performance parameters; (3) the ability to conduct high-resolution imaging with synthetic 2-D arrays of PI-etalon elements; and (4) work towards a fiber optic PI-etalon for in vivo use. Successful development of a fiber optic imager would provide a unique field-of-view thereby exposing an abundance of prospects for minimally-invasive analysis, diagnosis, and treatment of disease.

  10. Imaging of coronary atherosclerosis in various susceptible groups.

    PubMed

    Munnur, Ravi Kiran; Nerlekar, Nitesh; Wong, Dennis T L

    2016-08-01

    Coronary artery disease (CAD) is the leading cause of death and disability worldwide. Atherosclerosis, which is the primary pathophysiologic mechanism for the development of plaque leading to CAD, is a multifactorial process resulting from a complex interplay between genetic susceptibility and various risk factors such as hypertension (HT), dyslipidaemia, diabetes mellitus (DM) and smoking. In addition, influences from other disease states such as chronic kidney disease (CKD), obesity and the metabolic syndrome as well as gender and ethnic diversity also contribute to the disease process. Insights from pathological observations and advances in cellular and molecular biology have helped us understand the process of plaque formation, progression and rupture leading to events. Several intravascular imaging techniques such as intravascular ultrasound (IVUS), Virtual histology IVUS (VH-IVUS) and optical coherence tomography (OCT) allow in vivo assessment of plaque burden, plaque morphology and response to therapy. In addition, non invasive assessment using coronary artery calcium (CAC) score allows risk stratification and plaque burden assessment whilst computed tomography coronary angiography (CTCA) allows evaluation of luminal stenosis, plaque characterisation and quantification. This review aims to summarise the results of invasive and non-invasive imaging studies of coronary atherosclerosis seen in various high-risk populations including DM, metabolic syndrome, obesity, CKD and, gender differences and ethnicity. Understanding the phenotype of plaques in various susceptible groups may allow potential development of personalised therapies. PMID:27500095

  11. Imaging of coronary atherosclerosis in various susceptible groups

    PubMed Central

    Nerlekar, Nitesh; Wong, Dennis T. L.

    2016-01-01

    Coronary artery disease (CAD) is the leading cause of death and disability worldwide. Atherosclerosis, which is the primary pathophysiologic mechanism for the development of plaque leading to CAD, is a multifactorial process resulting from a complex interplay between genetic susceptibility and various risk factors such as hypertension (HT), dyslipidaemia, diabetes mellitus (DM) and smoking. In addition, influences from other disease states such as chronic kidney disease (CKD), obesity and the metabolic syndrome as well as gender and ethnic diversity also contribute to the disease process. Insights from pathological observations and advances in cellular and molecular biology have helped us understand the process of plaque formation, progression and rupture leading to events. Several intravascular imaging techniques such as intravascular ultrasound (IVUS), Virtual histology IVUS (VH-IVUS) and optical coherence tomography (OCT) allow in vivo assessment of plaque burden, plaque morphology and response to therapy. In addition, non invasive assessment using coronary artery calcium (CAC) score allows risk stratification and plaque burden assessment whilst computed tomography coronary angiography (CTCA) allows evaluation of luminal stenosis, plaque characterisation and quantification. This review aims to summarise the results of invasive and non-invasive imaging studies of coronary atherosclerosis seen in various high-risk populations including DM, metabolic syndrome, obesity, CKD and, gender differences and ethnicity. Understanding the phenotype of plaques in various susceptible groups may allow potential development of personalised therapies. PMID:27500095

  12. [Quantitative analyses of coronary artery calcification by using clinical cardiovascular imaging].

    PubMed

    Ehara, Shoichi; Yoshiyama, Minoru

    2010-11-01

    Coronary artery calcification (CAC) is a common phenomenon, but the clinical relevance of this phenomenon, for instance as a risk factor for plaque vulnerability, is still controversial. After the introduction of electron-beam computed tomography (EBCT), multislice computed tomography (MSCT), and intravascular ultrasound (IVUS), which enables quantitative assessment of CAC, the number of clinical studies concerning CAC has rapidly increased. In this review, we focus on the quantitative analyses of CAC by using clinical cardiovascular imaging and the clinical significance of CAC. PMID:21037389

  13. Ultrasound in space.

    PubMed

    Martin, David S; South, Donna A; Garcia, Kathleen M; Arbeille, Philippe

    2003-01-01

    Physiology of the human body in space has been a major concern for space-faring nations since the beginning of the space era. Ultrasound (US) is one of the most cost effective and versatile forms of medical imaging. As such, its use in characterizing microgravity-induced changes in physiology is being realized. In addition to the use of US in related ground-based studies, equipment has also been modified to fly in space. This involves alteration to handle the stresses of launch and different power and cooling requirements. Study protocols also have been altered to accommodate the microgravity environment. Ultrasound studies to date have shown a pattern of adaptation to microgravity that includes changes in cardiac chamber sizes and vertebral spacing. Ultrasound has been and will continue to be an important component in the investigation of physiological and, possibly, pathologic changes occurring in space or as a result of spaceflight.

  14. Ultrasound in space

    NASA Technical Reports Server (NTRS)

    Martin, David S.; South, Donna A.; Garcia, Kathleen M.; Arbeille, Philippe

    2003-01-01

    Physiology of the human body in space has been a major concern for space-faring nations since the beginning of the space era. Ultrasound (US) is one of the most cost effective and versatile forms of medical imaging. As such, its use in characterizing microgravity-induced changes in physiology is being realized. In addition to the use of US in related ground-based studies, equipment has also been modified to fly in space. This involves alteration to handle the stresses of launch and different power and cooling requirements. Study protocols also have been altered to accommodate the microgravity environment. Ultrasound studies to date have shown a pattern of adaptation to microgravity that includes changes in cardiac chamber sizes and vertebral spacing. Ultrasound has been and will continue to be an important component in the investigation of physiological and, possibly, pathologic changes occurring in space or as a result of spaceflight.

  15. Ultrasound applications in electrodiagnosis.

    PubMed

    Boon, Andrea J; Smith, Jay; Harper, C Michel

    2012-01-01

    This review article discusses the current scope of high-resolution diagnostic ultrasound in the diagnosis of neuromuscular disease, both as a complementary tool to electrodiagnosis and in some cases as a stand-alone imaging modality. Indications, limitations, potential for research, and training and credentialing are discussed. Indications include needle guidance for nerve conduction studies and needle electromyography, diagnosis of nerve entrapment, diagnostic muscle imaging via grayscale analysis, and dynamic real-time imaging, including sonopalpation, to provide additional diagnostic information. The role of neuromuscular ultrasound in research is discussed, including the need to evaluate the sensitivity, specificity, positive and negative predictive value, and cost-effectiveness of these techniques when they are used alone or in combination. Training and credentialing are reviewed, specifically noting the challenge of the lack of formal training programs and the relatively long, flat learning curve of diagnostic ultrasound.

  16. Ultrasound of Peripheral Nerves

    PubMed Central

    Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

    2013-01-01

    Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

  17. Robotically assisted ultrasound interventions

    NASA Astrophysics Data System (ADS)

    Ding, Jienan; Swerdlow, Dan; Wang, Shuxin; Wilson, Emmanuel; Tang, Jonathan; Cleary, Kevin

    2008-03-01

    The goal of this project is to develop a robotic system to assist the physician in minimally invasive ultrasound interventions. In current practice, the physician must manually hold the ultrasound probe in one hand and manipulate the needle with the other hand, which can be challenging, particularly when trying to target small lesions. To assist the physician, the robot should not only be capable of providing the spatial movement needed, but also be able to control the contact force between the ultrasound probe and patient. To meet these requirements, we are developing a prototype system based on a six degree of freedom parallel robot. The system will provide high bandwidth, precision motion, and force control. In this paper we report on our progress to date, including the development of a PC-based control system and the results of our initial experiments.

  18. [The successful prolongation of a twin preterm pregnancy complicated by a dead fetus and disseminated intravascular coagulation].

    PubMed

    Hasbún, J; Muñoz, H; von Mühlenbrock, R; Pommer, R; Fardella, P; Yuri, C

    1992-01-01

    A clinical case of twin pregnancy with one in utero death fetus, at 24 weeks of gestation is presented, accompanied by disseminated intravascular coagulation. The successful treatment with heparin its described.

  19. Optimizing methods for the study of intravascular lipid metabolism in zebrafish.

    PubMed

    Chen, Kan; Wang, Chang-Qian; Fan, Yu-Qi; Xie, Yu-Shui; Yin, Zhao-Fang; Xu, Zuo-Jun; Zhang, Hui-Li; Cao, Jia-Tian; Han, Zhi-Hua; Wang, Yue; Song, Dong-Qiang

    2015-03-01

    The zebrafish (Danio rerio) is a useful vertebrate model for use in cardiovascular drug discovery. The present study aimed to construct optimized methods for the study of intravascular lipid metabolism of zebrafish. The lipophilic dye, Oil Red O, was used to stain fasting zebrafish one to eight days post-fertilization (dpf) and to stain 7-dpf zebrafish incubated in a breeding system containing 0.1% egg yolk as a high-fat diet (HFD) for 48 h. Three-dpf zebrafish were kept in CholEsteryl boron-dipyrromethene (BODIPY) 542/563 C11 water for 24 h which indicated the efficiency of CholEsteryl BODIPY 542/563 C11 intravascular cholesterol staining. Subsequently, 7-dpf zebrafish were incubated in water containing the fluorescent probe CholEsteryl BODIPY 542/563 C11 and fed a high-cholesterol diet (HCD) for 10 d. Two groups of 7-dpf zebrafish were incubated in regular breeding water and fed with a regular or HCD containing CholEsteryl BODIPY 542/563 C11 for 10 d. Finally, blood lipids of adult zebrafish fed with regular or HFD for seven weeks were measured. Oil Red O was not detected in the blood vessels of 7-8-dpf zebrafish. Increased intravascular lipid levels were detected in 7-dpf zebrafish incubated in 0.1% egg yolk, indicated by Oil Red O staining. Intravascular cholesterol was efficiently stained in 3-dpf zebrafish incubated in breeding water containing CholEsteryl BODIPY 542/563 C11; however, this method was inappropriate for the calculation of intravascular fluorescence intensity in zebrafish >7‑dpf. In spite of this, intra-aortic fluorescence intensity of zebrafish fed a HCD containing CholEsteryl BODIPY 542/563 C11 was significantly higher (P<0.05) than that of those fed a regular diet containing CholEsteryl BODIPY 542/563 C11. The serum total cholesterol and triglyceride levels of adult zebrafish fed a HFD were markedly increased compared to those of the control group (P<0.05). In conclusion, the use of Oil Red O staining and CholEsteryl BODIPY 542/563 C11 may

  20. Ultrasound for neuraxial blockade.

    PubMed

    Srinivasan, Karthikeyan Kallidaikurichi; Lee, Peter John; Iohom, Gabriella

    2014-12-01

    Neuraxial blockade is still largely performed as a blind procedure. Despite of developments in the type of needles used and drugs administered, the process of locating the epidural or intra-thecal space is still limited to identification of landmarks by palpation and reliance on tactile feedback of the operator. Ultrasound has provided the long needed "eye" to the procedure and has already shown promise of improving the safety and efficacy or neuraxial blocks. This review focuses on understanding the sonoanatomy of the neuraxial space, performing a systematic pre-procedural ultrasound scan, and reviewing the available evidence. PMID:25463890

  1. Focused Ultrasound and Lithotripsy.

    PubMed

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  2. Focused Ultrasound and Lithotripsy.

    PubMed

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  3. Cardiac 4D Ultrasound Imaging

    NASA Astrophysics Data System (ADS)

    D'hooge, Jan

    Volumetric cardiac ultrasound imaging has steadily evolved over the last 20 years from an electrocardiography (ECC) gated imaging technique to a true real-time imaging modality. Although the clinical use of echocardiography is still to a large extent based on conventional 2D ultrasound imaging it can be anticipated that the further developments in image quality, data visualization and interaction and image quantification of three-dimensional cardiac ultrasound will gradually make volumetric ultrasound the modality of choice. In this chapter, an overview is given of the technological developments that allow for volumetric imaging of the beating heart by ultrasound.

  4. [Intravascular biocompatibility of decellularized xenogenic vascular scaffolds/PHBHHx hybrid material for cardiovascular tissue engineering].

    PubMed

    Wu, Song; Liu, Yinglong; Cui, Bin; Tang, Yue; Wang, Qiang; Qu, Xianghua; Chen, Guoqiang

    2008-04-01

    Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate, PHBHHx) has superior mechanical and biocompatibility that may enable it to meet cardiovascular tissue engineering applications. We developed hybrid materials based on decellularized xenogenic vascular scaffolds that were coated with PHBHHx to investigate the intravascular biocompatibility. The hybrid patches were implanted in the rabbit abdominal aorta (hybrid patch, n = 12). Only decellularized xenogenic vascular scaffolds were implanted without coating as control (uncoated patch, n = 12). The patches were explanted and examined histologically, and biochemically at 1, 4 and 12 weeks after the surgery. The hybrid patches maintained original shapes, covered by confluent layer of cells and had less calcification than uncoated control. The results indicated that PHBHHx coating reduced calcification, promoted the repopulation of hybrid patch with recipients cells. In conclusion, PHBHHx showed remarkable intravascular biocompatibility and would benefit endothelization which would be a useful candidate for lumen of cardiovascular tissue engineering. PMID:18616171

  5. An Arthrobacter spp. bacteremia leading to fetal death and maternal disseminated intravascular coagulation.

    PubMed

    Shigeta, Naoya; Ozaki, Kimiaki; Hori, Kensuke; Ito, Kimihiko; Nakayama, Masahiro; Nakahira, Kumiko; Yanagihara, Itaru

    2013-02-01

    A 34-year-old parous woman developed high fever and threatened preterm labor after a 1-day trip, for which she was receiving prenatal care at a hospital. Three days after onset, at 24 4/7 weeks of gestation, she was transferred to our hospital in an emergency. Soon after the woman's arrival at our hospital, the infant was spontaneously stillborn via a transvaginal delivery. Laboratory tests revealed severe maternal disseminated intravascular coagulation with renal and liver insufficiency. Histopathologic examination of the placenta revealed vast fibrin deposition and remarkable neutrophilic infiltration in the intervillous space, suggesting a rare bacterial infection caused by Arthrobacter spp. The bacteria were predominantly detected in the placenta and maternal blood serum by common bacterial 16S rRNA sequencing after polymerase chain reaction amplification. We report the first case, to our knowledge, of bacteremia with Arthrobacter spp., which may lead to maternal disseminated intravascular coagulation and intrauterine fetal death.

  6. Enhanced glucose tolerance by intravascularly administered piceatannol in freely moving healthy rats.

    PubMed

    Oritani, Yukihiro; Okitsu, Teru; Nishimura, Eisaku; Sai, Masahiko; Ito, Tatsuhiko; Takeuchi, Shoji

    2016-02-12

    Piceatannol is a phytochemical in the seeds of passion fruit that has a hypoglycemic effect when orally administered. To elucidate the contribution of intact and metabolites of piceatannol after gastro-intestinal absorption to hypoglycemic effect, we examined the influence of piceatannol and isorhapontigenin on blood glucose concentrations during fasting and glucose tolerance tests by administering them intravascularly to freely moving healthy rats. We found that intravascularly administered piceatannol reduced the blood glucose concentrations during both fasting and glucose tolerance tests, but isorhapontigenin did not during either of them. Furthermore, we found that piceatannol increased the insulinogenic index during glucose tolerance tests and that piceatannol had no influence on insulin sensitivity by performing hyperinsulinemic euglycemic clamping tests. These results suggest that piceatannol orally intaken may enhance glucose tolerance by the effect of intact piceatannol through enhanced early-phase secretion of insulin. Therefore, oral intake of piceatannol might contribute to proper control of postprandial glycemic excursions in healthy subjects.

  7. [Intravascular lymphoma treated with anti CD20 monoclonal antibodies. Report of one case].

    PubMed

    Alfaro, Jorge; Espinoza, Arturo; Manŕiquez, María; Moyano, Leonor; González, Néstor; Larrondo, Milton; Figueroa, Gastón

    2004-11-01

    We report a 78 year old male with prostatism, that was subjected to a prostate biopsy. The pathological study showed a microvascular lymphocytic infiltration. Four months later, the patients presented with reduced alertness, cough, dyspnea, fever and elevation of lactic dehydrogenase and erythrocyte sedimentation rate. Chest and abdominal CAT scans, bone marrow aspirate, protein electrophoresis and prostate specific antigen were normal. A re-evaluation of prostate biopsy showed an intravascular lymphoid infiltration, positive for CD45 and CD20, compatible with the diagnosis of intravascular lymphoma. Chemotherapy was started, but it was not tolerated by the patient and the response was partial. Therefore, treatment with monoclonal antibodies anti CD20 (Rituximab) was started. The tumor had a complete and prolonged (24 months) remission after the treatment

  8. Intravascular ATP and the regulation of blood flow and oxygen delivery in humans.

    PubMed

    Crecelius, Anne R; Kirby, Brett S; Dinenno, Frank A

    2015-01-01

    Regulation of vascular tone is a complex response that integrates multiple signals that allow for blood flow and oxygen supply to match oxygen demand appropriately. Here, we discuss the potential role of intravascular adenosine triphosphate (ATP) as a primary factor in these responses and put forth the hypothesis that deficient ATP release contributes to impairments in vascular control exhibited in aged and diseased populations. PMID:25390296

  9. Laparoscopic Manipulation of a Probe-based Confocal Laser Endomicroscope Using a Steerable Intravascular Catheter

    PubMed Central

    Desjardins, Adrien E.; Gurusamy, Kurinchi; Hawkes, David J.; Davidson, Brian R.

    2015-01-01

    Probe-based confocal laser endomicroscopy is an emerging imaging modality that enables visualization of histologic details during endoscopy and surgery. A method of guiding the probe with millimeter accuracy is required to enable imaging in all regions of the abdomen accessed during laparoscopy. On the basis of a porcine model of laparoscopic liver resection, we report our experience of using a steerable intravascular catheter to guide a probe-based confocal laser endomicroscope. PMID:25807277

  10. Surgical management of Wilms tumor with intravascular extension: a single-institution experience.

    PubMed

    Aspiazu, Diego; Fernandez-Pineda, Israel; Cabello, Rosa; Ramirez, Gema; Alvarez-Madrid, Antonio; De Agustin, Juan Carlos

    2012-02-01

    The purpose of this study was to retrospectively analyze the clinical presentation, treatment, and outcomes of children with Wilms tumor (WT) and intravascular extension who were treated at a single institution. A retrospective review was conducted of medical records of all children with Wilms tumor and intravascular extension treated at Virgen del Rocio Children's Hospital between 1992 and 2010. Seven patients (median age 3.4 years, range 2-8.1 years) were identified. At diagnosis, 6 of the 7 patients (85.7%) presented with tumor thrombus that reached the right atrium (RA) and 1 patient with infrahepatic inferior vena cava (IVC) thrombus. All patients received neoadjuvant chemotherapy (SIOP 2001 protocol) with vincristine, doxorubicin, and actinomycin D. Regression of the intravascular extension of the tumor was documented in all patients. Postchemotherapy level of extension was suprahepatic IVC in 1 patient, infrahepatic IVC in 2 patients, renal vein (RV) in 1 patient, and RA in 3 patients. Nephrectomy and thrombectomy were performed in all cases, requiring cardiopulmonary bypass for the 4 patients who presented with suprahepatic IVC and RA thrombus. The other 3 patients with infrahepatic IVC and RV involvement underwent cavotomy and thrombus extraction. Computed tomography, ultrasonography, and echocardiography were used for diagnosis and follow-up. All patients remain disease-free with a median follow-up of 6.3 years (range, 2-19 years). Neoadjuvant chemotherapy for WT with intravascular extension may facilitate the resection by decreasing the extent of the tumor thrombus. Cardiopulmonary bypass is indicated for suprahepatic IVC and RA involvement. Accurate diagnostic imaging is necessary.

  11. Recurrent thrombotic occlusions of arteries and veins caused by intravascular metastatic adenocarcinoma.

    PubMed Central

    Levi, M; Bronkhorst, C; Noorduyn, L A; Vreeken, J

    1994-01-01

    The occurrence of unexplained, rapidly recurring occlusions of arteries and veins in a previously healthy young woman is described. Post mortem examination showed no macroscopic abnormalities but revealed microscopic metastatic adenocarcinoma with remarkable intravascular localisation of the malignant cells. Whereas highly sensitive markers for the existence of systemic activation of blood coagulation remained within the normal range, it is suggested that specific characteristics of the tumour cells may have been responsible for this particular clinical presentation. PMID:7962660

  12. Effect of intravascular irradiation of He-Ne laser on cerebral infarction: Hemorrheology and apoptosis

    NASA Astrophysics Data System (ADS)

    Zhu, Jian; Liang, Min-yi; Cao, Hao-cai; Li, Xiao-Yuan; Li, Shao-ming; Li, Shun-hao; Li, Wen-qi; Zhang, Jin-hong; Liu, Lei; Lai, Jian-hong

    2005-07-01

    Objective: To explore the efficacy of He-Ne laser intravascular irradiation on infarction and hemorrheology. To observe the effects of intravascular low level He-Ne laser irradiation (ILLLI) of blood on cell proliferation, apoptosis and chromosome in lymphocyte from cerebral infarction Methods: Seventy cases with cerebral infarction were randomly divided into groups control group (35 cases) treated only with common drugs and therapeutic group (35 cases) treated besides common drugs also by He-Ne laser intravascular irradiation. Their hemorrheology index and treatment results were observed and compared. The blood lymphocytes of cerebral infarction were cultured before and after treatment. After that, the mitosis index (MI), cell kinetics index (CKI), sister-chromatid exchanges (SCE) frequencies and apoptosis were determined. Results The therapeutic group was better than the control one. The effective rate in the therapeutic group was 88.6%, in the control one was 65.7%. The viscosity and fibrinogen, etc were better than that in the control group with significant difference (P<0.01). The lymphocyte proliferation index was significantly two increased than the control one (P>0.05) in cerebral infarction patients after treatment; The CKI of lymphocytes had no obvious difference among groups (P>0.05) SCE frequencies of lymphocytes had no statistic significance between control group and ILLLI on (P>0.05). It showed the apoptosis rate of lymphocytes in cerebral infarction patients after ILLLI treatment increased significantly compared with the control group, (P<0.001). There was a significant difference of apoptosis rate of lymphocytes in cerebral infarction patients than the control (P<0.001). Conclusions: During the He-Ne laser intravascular irradiation of the cerebral infarction, the low level He-Ne by ILLLI can increase the proliferation of lymphocytes, and can induce lymphocytes to apoptosis, but has no mutagenicity of cells.

  13. [Evaluation of the severity course and prognosis of disseminated intravascular blood coagulation syndrome].

    PubMed

    Kinakh, M V; Chaplyk, V V; Fedchyshyn, N R

    2009-01-01

    Activation of the peroxidal oxidation of lipids (POL) processes with its primary and secondary products levels raising constitutes a favourable sign, according to data of examination of 66 patients, suffering different phases of disseminated intravascular blood coagulation syndrome (DIBCS). The POL products contents reduction (areactive course) characterizes the process severity and constitutes an unfavourable prognostical sign. The areactive course rate is the highest in the patients, suffering DIBCS, phase III.

  14. Isolated Intravascular Large B-cell Lymphoma Presenting with Diffuse Ground Glass Pulmonary Infiltrates.

    PubMed

    Srivali, Narat; Pannu, Bibek S; Iyer, Vivek N

    2016-06-01

    A case of 44-year-old man with dyspnea and CT chest demonstrated bilateral infiltration. Patient was failed to improve with antibiotics and steroid. Finally, video-assisted thoracic surgery-guided lung biopsy was performed and surprisingly revealed intravascular large B cell lymphoma. The patient was subsequently started on chemotherapy with considerable clinical improvement. At the time of last follow-up (4 years from diagnosis); there was no clinical or radiologic evidence of tumor recurrence. PMID:27408440

  15. Ultrasound and the IRB

    ERIC Educational Resources Information Center

    Epstein, Melissa A.

    2005-01-01

    The purpose of this paper is to assist researchers in writing their research protocols and subject consent forms so that both the Institutional Review Board (IRB) and subjects are assured of the minimal risk associated with diagnostic B-scan ultrasound as it is used in speech research. There have been numerous epidemiological studies on fetal…

  16. Doppler ultrasound monitoring technology.

    PubMed

    Docker, M F

    1993-03-01

    Developments in the signal processing of Doppler ultrasound used for the detection of fetal heart rate (FHR) have improved the operation of cardiotocographs. These developments are reviewed and the advantages and disadvantages of the various Doppler and signal processing methods are compared.

  17. [Therapies by focused ultrasound].

    PubMed

    Grenier, N; Trillaud, H; Palussière, J; Mougenot, C; Quesson, B; Denis De Senneville, B; Moonen, C

    2007-11-01

    Many techniques of thermotherapy have emerged over the last several years in the field of oncology using different types of physical agents, including ultrasound. Only ultrasound can target deep seated lesions non-invasively without need for percutaneous probe insertion. Depending on their utilization, it is possible to select either thermal effects, in a continuous mode, at low temperature (allowing thermo-induced biological effects) or at high temperature (allowing thermoablation), or mechanical effects, in a pulsed mode, at low energy level (allowing biological effects) or at high energy levels (histotripsy). Thermoablation by focused ultrasound is now developing fast for applications in many organs. It gained a well defined role for the treatment of prostatic cancer and uterine leiomyoma but needs to be better evaluated in other organs such as the breast. Treatment of abdominal tumors must still be considered as experimental as long as problems related to acoustic interfaces (produced by ribs and gas) and movement correction are not resolved. Biological applications of focused ultrasound are currently being explored and have a great long term potential.

  18. [Ultrasound guided percutaneous nephrolithotripsy].

    PubMed

    Guliev, B G

    2014-01-01

    The study was aimed to the evaluation of the effectiveness and results of ultrasound guided percutaneous nephrolithotripsy (PNL) for the treatment of patients with large stones in renal pelvis. The results of PNL in 138 patients who underwent surgery for kidney stones from 2011 to 2013 were analyzed. Seventy patients (Group 1) underwent surgery with combined ultrasound and radiological guidance, and 68 patients (Group 2)--only with ultrasound guidance. The study included patients with large renal pelvic stones larger than 2.2 cm, requiring the formation of a single laparoscopic approach. Using the comparative analysis, the timing of surgery, the number of intra- and postoperative complications, blood loss and length of stay were evaluated. Percutaneous access was successfully performed in all patients. Postoperative complications (exacerbation of chronic pyelonephritis, gross hematuria) were observed in 14.3% of patients in Group 1 and in 14.7% of patients in Group 2. Bleeding requiring blood transfusion, and injuries of adjacent organs were not registered. Efficacy of PNL in the Group 1 was 95.7%; 3 (4.3%) patients required additional interventions. In Group 2, the effectiveness of PNL was 94.1%, 4 (5.9%) patients additionally underwent extracorporeal lithotripsy. There were no significant differences in the effectiveness of PNL, the volume of blood loss and duration of hospitalization. Ultrasound guided PNL can be performed in large pelvic stones and sufficient expansion of renal cavities, thus reducing radiation exposure of patients and medical staff.

  19. Basic Principles of Ultrasound

    NASA Astrophysics Data System (ADS)

    Robinson, Teresa M.

    Ultrasound has been used in medicine for at least 50 years. Its current importance can be judged by the fact that, of all the various kinds of diagnostic images produced in the world, 1 in 4 is an ultrasound scan. Ultrasound energy is exactly like sound energy, it is a variation in the pressure within a medium. The only difference is that the rate of variation of pressure, the frequency of the wave, is too rapid for humans to hear. Medical ultrasound lies within a frequency range of 30 kHz to 500 MHz. Generally, the lower frequencies (30 kHz to 3 MHz) are for therapeutic purposes, the higher ones (2 to 40 MHz) are for diagnosis (imaging and Doppler), the very highest (50 to 500 MHz) are for microscopic images. For diagnostic purposes two main techniques are employed; the pulse-echo method is used to create images of tissue distribution; the Doppler effect is used to assess tissue movement and blood flow.

  20. [Ultrasound guided percutaneous nephrolithotripsy].

    PubMed

    Guliev, B G

    2014-01-01

    The study was aimed to the evaluation of the effectiveness and results of ultrasound guided percutaneous nephrolithotripsy (PNL) for the treatment of patients with large stones in renal pelvis. The results of PNL in 138 patients who underwent surgery for kidney stones from 2011 to 2013 were analyzed. Seventy patients (Group 1) underwent surgery with combined ultrasound and radiological guidance, and 68 patients (Group 2)--only with ultrasound guidance. The study included patients with large renal pelvic stones larger than 2.2 cm, requiring the formation of a single laparoscopic approach. Using the comparative analysis, the timing of surgery, the number of intra- and postoperative complications, blood loss and length of stay were evaluated. Percutaneous access was successfully performed in all patients. Postoperative complications (exacerbation of chronic pyelonephritis, gross hematuria) were observed in 14.3% of patients in Group 1 and in 14.7% of patients in Group 2. Bleeding requiring blood transfusion, and injuries of adjacent organs were not registered. Efficacy of PNL in the Group 1 was 95.7%; 3 (4.3%) patients required additional interventions. In Group 2, the effectiveness of PNL was 94.1%, 4 (5.9%) patients additionally underwent extracorporeal lithotripsy. There were no significant differences in the effectiveness of PNL, the volume of blood loss and duration of hospitalization. Ultrasound guided PNL can be performed in large pelvic stones and sufficient expansion of renal cavities, thus reducing radiation exposure of patients and medical staff. PMID:25807772

  1. The intravascular low level laser irradiation (ILLLI) in treatment of psoriasis clinically

    NASA Astrophysics Data System (ADS)

    Zhu, Jing; Nie, Fan; Shi, Hong-Min

    2005-07-01

    Objective: The title is research curative effect of intravascular low level laser irradiation (ILLLI) in treatment of psoriasis. Method: 478 patients with psoriasis from five groups to observe their efficacy. Group1 were treated by He-Ne laser combined with drug. Group 2 were treated by semi-conductor laser combined with drug. Group 3 were treated only by He-He laser. Group 4 were treated by semi-conductor laser. Group 5 were treated only by drug. The Ridit statistical analysis was applied to all of these data. The treatment of intravascular low level laser irradiation is as follow: laser power:4-5mw, 1 hour per day and 10 days as a period combined with vit C 2.0 g iv and inhalation of O2. Results: The clinical results: the near efficient rate was 100%, in group1-4, if combined with drugs it would be better. Ridit statistical analysis showed no significant difference between group1-4, p>0.05. The efficient rate 72.97% in group5.There were showed very significant difference with group1-4, p<0.01. 2.There were no significant differences between He-Ne laser (632.8nm) and semiconductor laser(650nm); 3.The efficacy of ILLLI in psoriasis was positive correlation to the ILLLI times. Conclusions: It can improve curative effect of intravascular low levellaser irradiation (ILLLI) in treatment of psoriasis.

  2. Stochastic bifurcation characteristics of SMA intravascular stent subjected to radial and axial excitations.

    PubMed

    Zhu, Zhiwen; Zhang, Wendi; Xu, Jia

    2014-01-01

    A kind of shape memory alloy (SMA) hysteretic nonlinear model is developed, and the stochastic bifurcation characteristics of SMA intravascular stents subjected to radial and axial excitations are studied in this paper. A new nonlinear differential item is introduced to interpret the hysteretic phenomena of SMA strain-stress curves, and the dynamic model of SMA intravascular stent subjected to radial and axial stochastic excitations is established. The conditions of the system's stochastic stability are determined, and the probability density function of the system response is obtained. Finally, the stochastic Hopf bifurcation characteristics of the system are analyzed. Theoretical analysis and numerical simulation show that the system stability varies with bifurcation parameters, and stochastic Hopf bifurcation occurs in the process; there are two limit cycles in the stationary probability density of the system response in some cases, which means that there are two vibration amplitudes whose probability are both very high; jumping phenomena between the two vibration amplitudes appears with the change of conditions, which may cause stent fracture or loss. The results of this paper are helpful for application of SMA intravascular stent in biomedical engineering fields.

  3. The neuroprotective effects of intravascular low level laser irradiation on cerebral ischemia rats

    NASA Astrophysics Data System (ADS)

    Qiu, Yongming; Lu, Zhaofeng; Wang, Zhongguang; Jiang, Jiyao

    2005-07-01

    The effects of intravascular low level laser irradiation of He-Ne on rat MCAo-induced cerebral injury were studied. The results showed that control rats (subjected to MCAo injury without laser treatment) at 7d exhibited striatal and cortical brain infarction in the right hemisphere from approximately 3 to 11mm from the front pole. the total infarct volume in this group was 34.5+/-8.1mm3. For experimental rats (with laser management), the total infarct volume was 29.0+/-9.0mm3. P was gained less than 0.05. The neurological score of control group was 4.7+/-0.6 and it was 5.2+/-1.0 in experimental group, comparison by statistical analysis showed P less than 0.05. The cerebral pathological damages in the control group were more severe than in experimental group. We concluded that the intravascular low level laser irradiation has no remarked complication and is helpful to reduce ischemic damage. There is clinically potential for the application of intravascular He-Ne low level laser irradiation in ischemia stroke.

  4. Use of an oxygen-carrying blood substitute to improve intravascular optical coherence tomography imaging

    NASA Astrophysics Data System (ADS)

    Hoang, Khiet C.; Edris, Ahmad; Su, Jianping; Mukai, David S.; Mahon, Sari; Petrov, Artiom D.; Kern, Morton; Ashan, Chowdhury; Chen, Zhongping; Tromberg, Bruce J.; Narula, Jagat; Brenner, Matthew

    2009-05-01

    Optical coherence tomography (OCT) is a catheter-based imaging technology with powerful resolution capable of identifying vulnerable plaques and guiding coronary intervention. However, a significant limitation of intravascular OCT imaging is its attenuation by blood. We propose that the use of an oxygen-carrying blood substitute could potentially optimize OCT image quality. Surgical isolation of the descending thoracic aorta of six rabbits is performed, followed by intravascular OCT imaging of the abdominal aorta. Perfluorodecalin (PFD) is oxygenated using a bubble-through technique with 100% oxygen. OCT imaging is performed and compared using three different flushing modalities: PFD; saline; and blood. OCT imaging of the rabbit abdominal aorta is successful in all of the subjects. In each of the six studied subjects, flushing with PFD consistently provides dramatically better imaging of the vessel wall tissue structures. OCT image quality is highly dependent on the ability of the flushing modality to remove blood from the imaging field. From this proof-of-concept study, we demonstrate that endovascular flushing with an oxygen-carrying blood substitute (PFD) is optically superior to saline flushing for intravascular imaging.

  5. Development of an intravascular pumping oxygenator using a new silicone membrane.

    PubMed

    Sueda, T; Fukunaga, S; Morita, S; Sueshiro, M; Hirai, S; Okada, K; Orihashi, K; Matsuura, Y

    1997-01-01

    A new intravascular pumping oxygenator (IVPO) was developed for intravascular gas exchange and circulatory assistance in critically ill patients with respiratory and circulatory failure. The IVPO utilizes new silicone hollow fibers (diameter, 1 mm; membrane width, 50 microns) and consists of two driving tubes for the oxygenation and pumping of circulating blood. The performance characteristics of the IVPO were studied using an experiment ex vivo model. With a mean hemoglobin concentration of 10.5 +/- 2.3 g/dl, total oxygen transfer was 5.6 +/- 1.5 ml/min at a blood flow of 200 ml/min and 6.3 +/- 2.2 ml/min at a blood flow of 250 ml/min. Total CO2 transfer was 3.8 +/- 1.4 ml/min at a blood flow of 200 ml/min and 4.2 +/- 1.6 ml/min at a blood flow of 250 ml/min. Blood flow increased to a maximum of 250 ml/min during IVPO pumping. This preliminary experiment demonstrated that the IVPO has the capacity to function both as circulatory assist pump and as an intravascular hollow fiber oxygenator.

  6. [High frequency ultrasound].

    PubMed

    Sattler, E

    2015-07-01

    Diagnostic ultrasound has become a standard procedure in clinical dermatology. Devices with intermediate high frequencies of 7.5-15 MHz are used in dermato-oncology for the staging and postoperative care of skin tumor patients and in angiology for improved vessel diagnostics. In contrast, the high frequency ultrasound systems with 20-100 MHz probes offer a much higher resolution, yet with a lower penetration depth of about 1 cm. The main indications are the preoperative measurements of tumor thickness in malignant melanoma and other skin tumors and the assessment of inflammatory and soft tissue diseases, offering information on the course of these dermatoses and allowing therapy monitoring. This article gives an overview on technical principles, devices, mode of examination, influencing factors, interpretation of the images, indications but also limitations of this technique. PMID:25636803

  7. Biofouling control with ultrasound

    SciTech Connect

    Bott, T.R.

    2000-06-01

    Experiments have been carried out on a small-scale simulated cooling water system using a monoculture of Pseudomonas fluorescens to represent the slime-forming microbial community, to examine the opportunities for control using ultrasound. Glass tubes (18 mm I.D. x 1 m long) through which contaminated water flowed at 1 m/s were dosed with ultrasound along the tube axis. Glass tubes were employed to facilitate the use of infrared absorbance for biofilm accumulation assessment. The preliminary results demonstrate that control of biofilm formation and the removal of established biofilms on the inside of tubes may be achieved by the technology, but there may be some limitations with respect to removal.

  8. [High frequency ultrasound].

    PubMed

    Sattler, E

    2015-07-01

    Diagnostic ultrasound has become a standard procedure in clinical dermatology. Devices with intermediate high frequencies of 7.5-15 MHz are used in dermato-oncology for the staging and postoperative care of skin tumor patients and in angiology for improved vessel diagnostics. In contrast, the high frequency ultrasound systems with 20-100 MHz probes offer a much higher resolution, yet with a lower penetration depth of about 1 cm. The main indications are the preoperative measurements of tumor thickness in malignant melanoma and other skin tumors and the assessment of inflammatory and soft tissue diseases, offering information on the course of these dermatoses and allowing therapy monitoring. This article gives an overview on technical principles, devices, mode of examination, influencing factors, interpretation of the images, indications but also limitations of this technique.

  9. Sparsity driven ultrasound imaginga)

    PubMed Central

    Tuysuzoglu, Ahmet; Kracht, Jonathan M.; Cleveland, Robin O.; C¸etin, Müjdat; Karl, W. Clem

    2012-01-01

    An image formation framework for ultrasound imaging from synthetic transducer arrays based on sparsity-driven regularization functionals using single-frequency Fourier domain data is proposed. The framework involves the use of a physics-based forward model of the ultrasound observation process, the formulation of image formation as the solution of an associated optimization problem, and the solution of that problem through efficient numerical algorithms. The sparsity-driven, model-based approach estimates a complex-valued reflectivity field and preserves physical features in the scene while suppressing spurious artifacts. It also provides robust reconstructions in the case of sparse and reduced observation apertures. The effectiveness of the proposed imaging strategy is demonstrated using experimental data. PMID:22352501

  10. Ultrasound-Assisted Freezing

    NASA Astrophysics Data System (ADS)

    Delgado, A. E.; Sun, Da-Wen

    Freezing is a well-known preservation method widely used in the food industry. The advantages of freezing are to a certain degree counterbalanced by the risk of damage caused by the formation and size of ice crystals. Over recent years new approaches have been developed to improve and control the crystallization process, and among these approaches sonocrystallization has proved to be very useful, since it can enhance both the nucleation rate and the crystal growth rate. Although ultrasound has been successfully used for many years in the evaluation of various aspects of foods and in medical applications, the use of power ultrasound to directly improve processes and products is less popular in food manufacturing. Foodstuffs are very complex materials, and research is needed in order to define the specific sound parameters that aid the freezing process and that can later be used for the scale-up and production of commercial frozen food products.

  11. Prostate Focused Ultrasound Therapy.

    PubMed

    Chapelon, Jean-Yves; Rouvière, Olivier; Crouzet, Sébastien; Gelet, Albert

    2016-01-01

    The tremendous progress in engineering and computing power coupled with ultrasound transducer technology and imaging modalities over the past 20 years have encouraged a revival of clinical interest in ultrasound therapy, mainly in High-Intensity Focused Ultrasound (HIFU). So far, the most extensive results from HIFU obtained in urology involve transrectal prostate ablation, which appears to be an effective therapeutic alternative for patients with malignant prostate tumors. Prostate cancer (PCa) is one of the most frequently diagnosed cancers in men. Several treatment options with different therapeutic approaches exist, including HIFU for localized PCa that has been in use for over 15 years. Since the early 2000s, two systems have been marketed for this application, and other devices are currently in clinical trials. HIFU treatment can be used either alone or in combination with (before- or after-) external beam radiotherapy (EBRT) (before or after HIFU) and can be repeated multiple times. HIFU treatment is performed under real-time monitoring with ultrasound or guided by MRI. Two indications are validated today: Primary care treatment and EBRT failure. The results of HIFU for primary care treatment are similar to standard conformal EBRT, even though no randomized comparative studies have been performed and no 10-year follow up data is yet available for HIFU. Salvage HIFU after EBRT failure is increasing with oncological outcomes, similar to those achieved with surgery but with the advantage of fewer adverse effects. HIFU is an evolving technology perfectly adapted for focal treatment. Thus, HIFU focal therapy is another pathway that must be explored when considering the accuracy and reliability for PCa mapping techniques. HIFU would be particularly suited for such a therapy since it is clear that HIFU outcomes and toxicity are relative to the volume of prostate treated.

  12. Clinical ophthalmic ultrasound improvements

    NASA Technical Reports Server (NTRS)

    Garrison, J. B.; Piro, P. A.

    1981-01-01

    The use of digital synthetic aperture techniques to obtain high resolution ultrasound images of eye and orbit was proposed. The parameters of the switched array configuration to reduce data collection time to a few milliseconds to avoid eye motion problems in the eye itself were established. An assessment of the effects of eye motion on the performance of the system was obtained. The principles of synthetic techniques are discussed. Likely applications are considered.

  13. Benign breast lesions: Ultrasound

    PubMed Central

    Masciadri, N.; Ferranti, C.

    2011-01-01

    Benign breast diseases constitute a heterogeneous group of lesions arising in the mammary epithelium or in other mammary tissues, and they may also be linked to vascular, inflammatory or traumatic pathologies. Most lesions found in women consulting a physician are benign. Ultrasound (US) diagnostic criteria indicating a benign lesion are described as well as US findings in the most frequent benign breast lesions. PMID:23396888

  14. Tissue identification by ultrasound

    NASA Technical Reports Server (NTRS)

    Lecroissette, D. H.; Heyser, R. C.; Gammell, P. M.; Wilson, R. L.

    1978-01-01

    The ultrasonic properties of animal and human soft tissue were measured over the frequency range of 1.5 to 10.0 MHz. The method employed a swept-frequency, coherent technique known as time delay spectrometry. Measurements of attenuation versus frequency on liver, backfat, kidney, pancreas, spleen, breast, and other tissue were made. Considerable attention was paid to tissue handling and in determining the effects of fixing on the attenuation of ultrasound in the tissue.

  15. Pulmonary artery intimal sarcoma diagnosed using endobronchial ultrasound-guided transbronchial needle aspiration.

    PubMed

    Caraway, Nancy P; Salina, Davide; Deavers, Michael T; Morice, Rodolfo; Landon, Gene

    2015-01-01

    Intimal sarcoma of the pulmonary artery is a rare intraluminal malignant neoplasm that has an aggressive biological behavior, and early diagnosis may improve patient outcome. We describe a case of pulmonary artery intimal sarcoma diagnosed on cytologic material obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy with rapid on-site evaluation (ROSE). The aspirate showed loosely cohesive clusters of pleomorphic malignant spindled and epithelioid cells. An immunostain panel did not demonstrate any definitive mesenchymal or epithelial differentiation. The tumor's intraluminal origin was supported by radiographic imaging studies. Subsequently, the patient received preoperative chemotherapy and underwent tumor resection with reconstruction. This report describes the cytomorphologic features of this rare intravascular tumor and demonstrates how EBUS-TBNA with ROSE was instrumental in obtaining optimal cytologic sampling for ancillary studies, thus expediting the management.

  16. Pulmonary artery intimal sarcoma diagnosed using endobronchial ultrasound-guided transbronchial needle aspiration.

    PubMed

    Caraway, Nancy P; Salina, Davide; Deavers, Michael T; Morice, Rodolfo; Landon, Gene

    2015-01-01

    Intimal sarcoma of the pulmonary artery is a rare intraluminal malignant neoplasm that has an aggressive biological behavior, and early diagnosis may improve patient outcome. We describe a case of pulmonary artery intimal sarcoma diagnosed on cytologic material obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy with rapid on-site evaluation (ROSE). The aspirate showed loosely cohesive clusters of pleomorphic malignant spindled and epithelioid cells. An immunostain panel did not demonstrate any definitive mesenchymal or epithelial differentiation. The tumor's intraluminal origin was supported by radiographic imaging studies. Subsequently, the patient received preoperative chemotherapy and underwent tumor resection with reconstruction. This report describes the cytomorphologic features of this rare intravascular tumor and demonstrates how EBUS-TBNA with ROSE was instrumental in obtaining optimal cytologic sampling for ancillary studies, thus expediting the management. PMID:25745502

  17. A novel method for non-invasive plaque morphology analysis by coronary computed tomography angiography.

    PubMed

    Fujimoto, Shinichiro; Kondo, Takeshi; Kodama, Takahide; Fujisawa, Yasuko; Groarke, John; Kumamaru, Kanako K; Takamura, Kazuhisa; Matsunaga, Eriko; Miyauchi, Katsumi; Daida, Hiroyuki; Rybicki, Frank J

    2014-10-01

    Coronary computed tomography angiography (CCTA) plaque morphology based on conventional Hounsfield units relies on absolute CT numbers is influenced by imaging and anatomical variables. The project describes and tests a novel alternative method, termed the "labeling method", which uses relative CT numbers and 3-dimensional plaque structure. Using virtual histology intravascular ultrasound (VH-IVUS) as the reference standard, this study compares the labeling method to a conventional CT-number based method to determine coronary plaque morphology. Thirty-seven high-risk, non-calcified atherosclerotic coronary lesions were prospectively evaluated in 33 consecutive patients who underwent CCTA followed by VH-IVUS (mean interval 8.6 ± 13.3 days). CCTA-derived vessel and minimum lumen areas were compared to VH-IVUS measures. Fibrotic and necrotic core areas were calculated by both the labeling method to the CT-number based method; both were tested for agreement with reference standard VH-IVUS. Inter- and intra-observer correlations were assessed. CCTA significantly underestimated minimum lumen area when compared to VH-IVUS (mean difference -1.4 ± 0.9 mm(2), p < 0.0001). Necrotic core and fibrous areas quantified using the labeling method demonstrated superior correlation with VH-IVUS compared to those quantified using the CT-number based method, Pearson's r = 0.75 versus 0.42 and r = 0.80 and 0.59, respectively. Compared to VH-IVUS, limits of agreement for the labeling method-derived necrotic core (-2.0 to 2.5 mm(2)) and fibrous areas (0.6-8.0 mm(2)) were more narrow than those determined using the CT-number based method (-3.7 to 7.3 and -4.0 to 8.9 mm(2), respectively). Inter- and intraobserver correlations were excellent for all CCTA derived measures (r = 0.85-0.98). A novel CCTA-based labeling method offers an alternative to conventional CT-number based analyses for plaque morphology. The labeling method demonstrates superior correlation to VH-IVUS for measures of

  18. Ischemia monitoring in off-pump coronary artery bypass surgery using intravascular near-infrared spectroscopy

    PubMed Central

    Bernet, Franziska H; Reineke, David; Zerkowski, Hans-Reinhard; Baykut, Doan

    2006-01-01

    Background In off-pump coronary artery bypass surgery, manipulations on the beating heart can lead to transient interruptions of myocardial oxygen supply, which can generate an accumulation of oxygen-dependent metabolites in coronary venous blood. The objective of this study was to evaluate the reliability of intravascular near-infrared spectroscopy as a monitoring method to detect possible ischemic events in off-pump coronary artery bypass procedures. Methods In 15 elective patients undergoing off-pump myocardial revascularization, intravascular near-infrared spectroscopic analysis of coronary venous blood was performed. NIR signals were transferred through a fiberoptic catheter for signal emission and collection. For data analysis and processing, a miniature spectrophotometer with multivariate statistical package was used. Signal acquisition and analysis were performed before and after revascularization. Spectroscopic data were compared with hemodynamic parameters, electrocardiogram, transesophageal echocardiography and laboratory findings. Results A conversion to extracorporeal circulation was not necessary. The mean number of grafts per patient was 3.1 ± 0.6. An intraoperative myocardial ischemia was not evident, as indicated by electrocardiogram and transesophageal echocardiography. Continuous spectroscopic analysis showed reproducible absorption spectra of coronary sinus blood. Due to uneventful intraoperative courses, clear ischemia-related changes could be detected in none of the patients. Conclusion Our initial results show that intravascular near-infrared spectroscopy can reliably be used for an online intraoperative ischemia monitoring in off-pump coronary artery bypass surgery. However, the method has to be further evaluated and standardized to determine the role of spectroscopy in off-pump coronary artery bypass surgery. PMID:16723014

  19. Microparticle production, neutrophil activation, and intravascular bubbles following open-water SCUBA diving.

    PubMed

    Thom, Stephen R; Milovanova, Tatyana N; Bogush, Marina; Bhopale, Veena M; Yang, Ming; Bushmann, Kim; Pollock, Neal W; Ljubkovic, Marko; Denoble, Petar; Dujic, Zeljko

    2012-04-01

    The goal of this study was to evaluate annexin V-positive microparticles (MPs) and neutrophil activation in humans following decompression from open-water SCUBA diving with the hypothesis that changes are related to intravascular bubble formation. Sixteen male volunteer divers followed a uniform profile of four daily SCUBA dives to 18 m of sea water for 47 min. Blood was obtained prior to and at 80 min following the first and fourth dives to evaluate the impact of repetitive diving, and intravascular bubbles were quantified by trans-thoracic echocardiography carried out at 20-min intervals for 2 h after each dive. MPs increased by 3.4-fold after each dive, neutrophil activation occurred as assessed by surface expression of myeloperoxidase and the CD18 component of β(2)-integrins, and there was an increased presence of the platelet-derived CD41 protein on the neutrophil surface indicating interactions with platelet membranes. Intravascular bubbles were detected in all divers. Surprisingly, significant inverse correlations were found among postdiving bubble scores and MPs, most consistently at 80 min or more after the dive on the fourth day. There were significant positive correlations between MPs and platelet-neutrophil interactions after the first dive and between platelet-neutrophil interactions and neutrophil activation documented as an elevation in β(2)-integrin expression after the fourth dive. We conclude that MPs- and neutrophil-related events in humans are consistent with findings in an animal decompression model. Whether there are causal relationships among bubbles, MPs, platelet-neutrophil interactions, and neutrophil activation remains obscure and requires additional study.

  20. Frequency-Domain Intravascular Optical Coherence Tomography of the Femoropopliteal Artery

    SciTech Connect

    Karnabatidis, Dimitris Katsanos, Konstantinos; Paraskevopoulos, Ioannis; Diamantopoulos, Athanasios; Spiliopoulos, Stavros; Siablis, Dimitris

    2011-12-15

    Purpose: Optical coherence tomography (OCT) is a catheter-based imaging method that employs near-infrared light to produce high-resolution intravascular images. The authors report the safety and feasibility and illustrate common imaging findings of frequency-domain OCT (FD-OCT) imaging of the femoropopliteal artery in a series of 20 patients who underwent infrainguinal angioplasty. Methods: After crossing the lesion of interest, OCT was performed with a dextrose saline flush technique with simultaneous obstructive manual groin compression. An automatic pullback FD-OCT device was employed (each scan acquiring 54 mm of vessel lumen in 271 consecutive frames). OCT images were acquired before and after balloon dilatation and following provisional stenting if necessary and were evaluated for baseline characteristics of plaque or in-stent restenosis (ISR), vessel wall trauma after angioplasty, presence of thrombus, stent apposition, and tissue prolapse. Imaging follow-up was not included in this study's protocol. Results: Twenty-seven obstructive lesions (18 cases of de novo atherosclerosis and 9 of ISR) of the femoropopliteal artery were imaged and 148 acquisitions were analyzed in total. High-resolution intravascular OCT imaging with effective blood clearance was achieved in 93.9%. Failure was mainly attributed to preocclusive proximal lesions and/or collateral flow. Mixed features of lipid pool areas, calcium deposits, necrotic core, and fibrosis were identified in all of the imaged atherosclerotic lesions, whereas ISR was purely fibrotic. After balloon angioplasty, OCT identified extensive intimal tears in all cases and one case of severe dissection that biplane subtraction angiography failed to identify. Conclusions: Infrainguinal frequency-domain optical coherence tomography is safe and feasible and may provide intravascular high-resolution imaging of the femoropopliteal artery during infrainguinal angioplasty procedures.

  1. An electro-responsive hydrogel for intravascular applications: an in vitro and in vivo evaluation.

    PubMed

    Verbrugghe, Peter; Verhoeven, Jelle; Coudyzer, Walter; Verbeken, Eric; Dubruel, Peter; Mendes, Eduardo; Stam, Frank; Meuris, Bart; Herijgers, Paul

    2015-11-01

    There is a growing interest in using hydrogels for biomedical applications, because of more favourable characteristics. Some of these hydrogels can be activated by using particular stimuli, for example electrical fields. These stimuli can change the hydrogel shape in a predefined way. It could make them capable of adaptation to patient-specific anatomy even post-implantation. This is the first paper aiming to describe in vivo studies of an electro-responsive, Pluronic F127 based hydrogel, for intravascular applications. Pluronic methacrylic acid hydrogel (PF127/MANa) was in vitro tested for its haemolytic and cytotoxic effects. Minimal invasive implantation in the carotid artery of sheep was used to evaluate its medium-term biological effects, through biochemical, macroscopic, radiographic, and microscopic evaluation. Indirect and direct testing of the material gave no indication of the haemolytic effects of the material. Determination of fibroblast viability after 24 h of incubation in an extract of the hydrogel showed no cytotoxic effects. Occlusion was obtained within 1 h following in vivo implantation. Evaluation at time of autopsy showed a persistent occlusion with no systemic effects, no signs of embolization and mild effects on the arterial wall. An important proof-of-concept was obtained showing biocompatibility and effectiveness of a pluronic based electro-responsive hydrogel for obtaining an arterial occlusion with limited biological impact. So the selected pluronic-methacrylic acid based hydrogel can be used as an endovascular occlusion device. More importantly it is the first step in further development of electro-active hydrogels for a broad range of intra-vascular applications (e.g. system to prevent endoleakage in aortic aneurysm treatment, intra-vascular drug delivery).

  2. An electro-responsive hydrogel for intravascular applications: an in vitro and in vivo evaluation.

    PubMed

    Verbrugghe, Peter; Verhoeven, Jelle; Coudyzer, Walter; Verbeken, Eric; Dubruel, Peter; Mendes, Eduardo; Stam, Frank; Meuris, Bart; Herijgers, Paul

    2015-11-01

    There is a growing interest in using hydrogels for biomedical applications, because of more favourable characteristics. Some of these hydrogels can be activated by using particular stimuli, for example electrical fields. These stimuli can change the hydrogel shape in a predefined way. It could make them capable of adaptation to patient-specific anatomy even post-implantation. This is the first paper aiming to describe in vivo studies of an electro-responsive, Pluronic F127 based hydrogel, for intravascular applications. Pluronic methacrylic acid hydrogel (PF127/MANa) was in vitro tested for its haemolytic and cytotoxic effects. Minimal invasive implantation in the carotid artery of sheep was used to evaluate its medium-term biological effects, through biochemical, macroscopic, radiographic, and microscopic evaluation. Indirect and direct testing of the material gave no indication of the haemolytic effects of the material. Determination of fibroblast viability after 24 h of incubation in an extract of the hydrogel showed no cytotoxic effects. Occlusion was obtained within 1 h following in vivo implantation. Evaluation at time of autopsy showed a persistent occlusion with no systemic effects, no signs of embolization and mild effects on the arterial wall. An important proof-of-concept was obtained showing biocompatibility and effectiveness of a pluronic based electro-responsive hydrogel for obtaining an arterial occlusion with limited biological impact. So the selected pluronic-methacrylic acid based hydrogel can be used as an endovascular occlusion device. More importantly it is the first step in further development of electro-active hydrogels for a broad range of intra-vascular applications (e.g. system to prevent endoleakage in aortic aneurysm treatment, intra-vascular drug delivery). PMID:26474577

  3. Eptifibatide-induced thrombocytopenia: with thrombosis and disseminated intravascular coagulation immediately after left main coronary artery percutaneous coronary angioplasty.

    PubMed

    Tempelhof, Michael W; Benzuly, Keith H; Fintel, Dan; Krichavsky, Marc Z

    2012-01-01

    Early clinical trials of eptifibatide did not show a significant association between eptifibatide and the development of thrombocytopenia, thrombosis, or disseminated intravascular coagulation. However, more recent literature has suggested a significant association between eptifibatide and the development of thrombocytopenia and thrombosis. Although the true incidence and the pathophysiology of these associations are unknown, the development of these events can be life-threatening. Herein, we describe the case of a patient who experienced acute onset of profound thrombocytopenia, developing thrombosis, pulmonary emboli, and disseminated intravascular coagulation. This paper adds to the few previous reports of cases that suggested an association between thrombocytopenia, thrombosis, and the administration of eptifibatide. To the best of our knowledge, this is the first case report in the medical literature that associates the new onset of thrombocytopenia, thrombosis, and disseminated intravascular coagulation with the administration of eptifibatide. We also provide a subject review.

  4. Intravascular Papillary Endothelial Hyperplasia: Diagnostic Sequence and Literature Review of an Orofacial Lesion

    PubMed Central

    Guledgud, Mahima V.; Patil, Karthikeya; Saikrishna, Degala; Yelamali, Tejesh

    2014-01-01

    Intravascular papillary endothelial hyperplasia or Masson's tumor is a rare reactive disease of vascular origin characterized by exuberant proliferation of endothelial cells notably occurring within blood vessels of head, neck, and extremities. The importance of this entity is its ability to mimic a variety of diseases both benign and malignant in the orofacial region. Here, we present a case of Masson's tumor within the masseter muscle in a 40-year-old female with emphasis on the sequential investigative procedures performed to diagnose this entity. PMID:24891960

  5. Acute kidney injury and disseminated intravascular coagulation due to mercuric chloride poisoning

    PubMed Central

    Dhanapriya, J.; Gopalakrishnan, N.; Arun, V.; Dineshkumar, T.; Sakthirajan, R.; Balasubramaniyan, T.; Haris, M.

    2016-01-01

    Mercury is a toxic heavy metal and occurs in organic and inorganic forms. Inorganic mercury includes elemental mercury and mercury salts. Mercury salts are usually white powder or crystals, and widely used in indigenous medicines and folk remedies in Asia. Inorganic mercury poisoning causes acute kidney injury (AKI) and gastrointestinal manifestations and can be life-threatening. We describe a case with unknown substance poisoning who developed AKI and disseminated intravascular coagulation (DIC). Renal biopsy showed acute tubular necrosis. Later, the consumed substance was proven to be mercuric chloride. His renal failure improved over time, and his creatinine normalized after 2 months. PMID:27194836

  6. Intestinal Intravascular Large B-cell Lymphoma Mimicking Ulcerative Colitis with Secondary Membranoproliferative Glomerulonephritis.

    PubMed

    Kaneyuki, Daisuke; Komeno, Yukiko; Yoshimoto, Hiroshi; Yoshimura, Naoki; Iihara, Kuniko; Ryu, Tomiko

    2016-01-01

    A 47-year-old woman with ulcerative colitis (UC) was admitted to our hospital for renal dysfunction and progressive anemia. Colonoscopy revealed intestinal lesions and pathological findings showed intravascular large B-cell lymphoma (IVLBCL). According to the polymerase chain reaction analysis of sequential rectal specimens, we concluded that she suffered from intestinal BCL, not UC. After chemotherapy, her renal function progressed to nephrotic syndrome. The pathological findings of renal biopsy specimens indicated membranoproliferative glomerulonephritis (MPGN). Chemotherapy was continued and led to the remission of BCL and MPGN. We herein describe the first case of intestinal IVLBCL mimicking UC with secondary MPGN. PMID:27580553

  7. Intravascular low-level laser irradiation in the treatment of psoriasis

    NASA Astrophysics Data System (ADS)

    Zhu, Jing; Shi, Hong-Min; Zhang, Hui-Guo; Zhang, Mei-Jue; Xu, Jian; Zhou, Min; Hu, Guo-Qiang

    1998-11-01

    Liu TCY et al have put forward the biological information model on low intensity laser irradiation (BIML): low intensity laser irradiation couples with intracellular messenger through the chromophore absorption in the cell membrane: hot-color laser irradiation activates cAMP phosphodiestererase through Gi protein, or activates phosphoinositide phospholipase C through G protein, or activates one of receptor-associated kinases: cAMP; cold- color laser irradiation activates adenylate cyclase through Gs protein: cAMP$ARUP. In this paper, under the guidance of BIML, we applied the intravascular low intensity He-He laser irradiation on blood to a patient of idiopathic edema, and succeeded.

  8. Blue or red: which intravascular laser light has more effects in diabetic patients?

    PubMed

    KazemiKhoo, N; Ansari, F

    2015-01-01

    The effects of intravascular laser irradiation of blood (ILIB), with 405 and 632.8 nm on serum blood sugar (BS) level, were comparatively studied. Twenty-four diabetic type 2 patients received 14 sessions of ILIB with blue and red lights. BS was measured before and after therapy. Serum BS decreased highly significant after ILIB with both red and blue lights (p < 0.0001), but we did not find significant difference between red and blue lights. The ILIB effect would be of benefit in the clinical treatment of diabetic type 2 patients, irrespective of lasers (blue or red lights) that are used.

  9. Rash, disseminated intravascular coagulation and legionella: Episode 10 and a rewind into the past

    PubMed Central

    Thalanayar, Prashanth M.; Holguin, Fernando

    2015-01-01

    Legionella pneumophila is the most common cause of legionellosis and is one of the organisms causing atypical pneumonia. We report the presentation of disseminated intravascular coagulation (DIC) and skin rash in a single case of severe Legionella pneumonia. The unique clinical presentation of a diffuse rash diagnosed as purpura fulminans and the unpredictable variations encountered during the diagnostic work-up of the case make this write-up crucial. This article synthesizes all reported cases of L. pneumonia associated with cutaneous manifestations as well as cases presenting with DIC. Furthermore, this manuscript illustrates the correlation between cutaneous and coagulopathic manifestations, and morbidity and mortality from L. pneumonia. PMID:26236615

  10. Specific imaging of atherosclerotic plaque lipids with two-wavelength intravascular photoacoustics

    PubMed Central

    Wu, Min; Jansen, Krista; van der Steen, Antonius F. W.; van Soest, Gijs

    2015-01-01

    The lipid content in plaques is an important marker for identifying atherosclerotic lesions and disease states. Intravascular photoacoustic (IVPA) imaging can be used to visualize lipids in the artery. In this study, we further investigated lipid detection in the 1.7-µm spectral range. By exploiting the relative difference between the IVPA signal strengths at 1718 and 1734 nm, we could successfully detect and differentiate between the plaque lipids and peri-adventitial fat in human coronary arteries ex vivo. Our study demonstrates that IVPA imaging can positively identify atherosclerotic plaques using only two wavelengths, which could enable rapid data acquisition in vivo. PMID:26417500

  11. Primary bilateral adrenal intravascular large B-cell lymphoma associated with adrenal failure.

    PubMed

    Fukushima, Ayumi; Okada, Yosuke; Tanikawa, Takahisa; Onaka, Takashi; Tanaka, Aya; Higashi, Takehiro; Tsukada, Junichi; Tanaka, Yoshiya

    2003-07-01

    We report a rare case of bilateral primary adrenal non-Hodgkin's lymphoma with adrenal failure. A 66-year-old woman developed symptoms of adrenal failure. The cause of adrenal failure was suspected to be malignant lymphoma based on the high levels of serum soluble interleukin-2 receptor and LDH. Bilateral adrenalectomy was performed and pathological examination showed intravascular large B-cell lymphoma (IVL). Although complete remission was achieved, recurrence occurred three months later with brain metastases. IVL should be suspected in patients with bilateral adrenal tumors who present with rapidly progressive adrenal failure.

  12. Sudden death due to intravascular hemolysis after bladder irrigation with distilled water.

    PubMed

    Bell, M D

    1992-09-01

    A 45-year-old white man was hospitalized with gross hematuria, one month after cystoscopy and biopsy for the same complaint. The biopsy revealed cystitis glandularis. One day after admission, he developed seizures and died within hours. Autopsy, laboratory tests, and further questioning of the hospital staff showed that he died of acute hyponatremia and massive intravascular hemolysis after irrigating the bladder with sterile water. Two deep bladder ulcers with exposed veins served as the portals of entry. Until now, this fatal complication had been described only during transurethral surgery. Both a careful autopsy and hospital investigation is necessary to differentiate in-hospital natural death from iatrogenic fatality. PMID:1402764

  13. Addressing Phonological Questions with Ultrasound

    ERIC Educational Resources Information Center

    Davidson, Lisa

    2005-01-01

    Ultrasound can be used to address unresolved questions in phonological theory. To date, some studies have shown that results from ultrasound imaging can shed light on how differences in phonological elements are implemented. Phenomena that have been investigated include transitional schwa, vowel coalescence, and transparent vowels. A study of…

  14. [Ultrasound imaging of coronary artery].

    PubMed

    Fuse, Shigeto

    2014-09-01

    Coronary arterial anatomy and the terminology were reviewed. There is a specific portion of coronary artery aneurysm in Kawasaki disease. To investigate coronary arterial lesion, ultrasound imaging is useful because of non-invasive, high special and time resolu tion method. I explained the patient posture, the approaching method to the coronary arter ies, ultrasound setting, measurement of coronary arterial diameter and diastolic measurement.

  15. Effects of transducer position on backscattered intensity in coronary arteries.

    PubMed

    Courtney, Brian K; Robertson, Abel L; Maehara, Akiko; Luna, Jorge; Kitamura, Katsuhiro; Morino, Yoshihiro; Achalu, Radha; Kirti, Shailaja; Yock, Paul G; Fitzgerald, Peter J

    2002-01-01

    Acute myocardial infarction is a frequent cause of sudden death, and is typically initiated by the rupture of coronary artery plaques. The likelihood and severity of rupture are influenced by the plaque structures and components. Radiofrequency (RF) intravascular ultrasound (US) (IVUS-RF) measurements extend current IVUS imaging techniques and may eventually enable the in vivo identification of these features. However, IVUS-RF measurements are affected by the transducer's instantaneous position in the vessel. Specifically, backscattered intensity (BI) decreases as either the distance between the tissue and the transducer increases, or as the beam's angle of incidence on the tissue increases. IVUS-RF data were acquired from seven disease-free coronary arteries in vitro. The 0-dB level for BI was defined as the peak intensity of the reflection from a stainless-steel flat reflector at each distance. The baseline BI measured in adventitial tissue was -32.5 dB (at 0 degrees, 0 mm) with angle and distance dependencies of -0.172 dB/ degrees and -3.37 dB/mm. In contrast, the BI from combined intima and media was -38.2 dB with dependencies of -0.111 dB/ degrees and -4.46 dB/mm (p < 0.05 for all three parameters). Acknowledging and compensating for these effects may allow IVUS-RF to develop into a rapidly deployable tool for the clinical detection of vulnerable plaques and to monitor coronary artery disease progression and regression. PMID:11879955

  16. Endobronchial ultrasound elastography

    PubMed Central

    Dietrich, Christoph F.; Jenssen, Christian; Herth, Felix J. F.

    2016-01-01

    Elastographic techniques have recently become available as advanced diagnostic tools for tissue characterization. Strain elastography is a real-time technique used with transcutaneous ultrasound (US) and endoscopic US. Convincing evidence is available demonstrating a significant value of strain elastography for the discrimination of benign and malignant lymph nodes (LNs). This paper reviews preliminary data demonstrating the feasibility of performing real-time elastography during endobronchial US (EBUS) and a potential application of this technique for selection of LNs for EBUS-guided transbronchial needle aspiration in patients with lung cancer and extrathoracic malignancies. PMID:27503154

  17. Therapeutic Endoscopic Ultrasound

    PubMed Central

    Cheriyan, Danny

    2015-01-01

    Endoscopic ultrasound (EUS) technology has evolved dramatically over the past 20 years, from being a supplementary diagnostic aid available only in large medical centers to being a core diagnostic and therapeutic tool that is widely available. Although formal recommendations and practice guidelines have not been developed, there are considerable data supporting the use of EUS for its technical accuracy in diagnosing pancreaticobiliary and gastrointestinal pathology. Endosonography is now routine practice not only for pathologic diagnosis and tumor staging but also for drainage of cystic lesions and celiac plexus neurolysis. In this article, we cover the use of EUS in biliary and pancreatic intervention, ablative therapy, enterostomy, and vascular intervention. PMID:27118942

  18. Imaging By Ultrasound

    PubMed Central

    Kidney, Maria R.

    1986-01-01

    Imaging by ultrasound has dramatically changed the investigation and management of many clinical problems. It is useful in many different parts of the body. In this brief discussion, the following topics are considered: hepatic lesions, bleeding in early pregnancy, gynecological pathology (adnexal lesions), aortic aneurysms, thyroid nodules and scrotal masses. The usefulness of duplex carotid sonography, which combines ultrasonic imaging and Doppler studies, is also discussed. Other topics (gallstones, biliary obstruction, renal calculi, hydronephrosis) are discussed in the appropriate sections. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:21267202

  19. What's new in urologic ultrasound?

    PubMed Central

    Lal, Anupam; Naranje, Priyanka; Pavunesan, Santhosh Kumar

    2015-01-01

    Ultrasound is an imaging technology that has evolved swiftly and has come a long way since its beginnings. It is a commonly used initial diagnostic imaging modality as it is rapid, effective, portable, relatively inexpensive, and causes no harm to human health. In the last few decades, there have been significant technological improvements in the equipment as well as the development of contrast agents that allowed ultrasound to be even more widely adopted for urologic imaging. Ultrasound is an excellent guidance tool for an array of urologic interventional procedures and also has therapeutic application in the form of high-intensity focused ultrasound (HIFU) for tumor ablation. This article focuses on the recent advances in ultrasound technology and its emerging clinical applications in urology. PMID:26166960

  20. [Laparoscopic ultrasound in biliary diseases].

    PubMed

    Cociorvei, A; Calu, V

    2011-01-01

    Laparoscopic ultrasound is an intraoperative exploration of the abdominal viscera using ultrasounds. The aim of this work is to obviate this new method of exploration and to underline its advantages and limits. In this study were enroled 65 pacients with gallbladder stones, admitted in The Surgical Clinic, "Elias" Emergency Hospital, from October 2005 until December 2006. The measured parameters were CBD size and the presence of stones or sludge within CBD, and various methods were compared: abdominal ultrasound, laparoscopic ultrasound and laparoscopic cholangiography. The results allowed us to consider that laparoscopic ultrasound is a useful tool for the intraoperative diagnosis of choledocolithiasis. When compared to laparoscopic cholangiography, our study revealed the same specificity and positive predictive value, and a sensitivity of 0.93.