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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. Multi-frequency intravascular ultrasound (IVUS) imaging.

    PubMed

    Ma, Teng; Yu, Mingyue; Li, Jiawen; Munding, Chelsea E; 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 multifrequency 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.

  3. Understanding the economic impact of intravascular ultrasound (IVUS).

    PubMed

    Alberti, Alessandro; Giudice, Pietro; Gelera, Alessandra; Stefanini, Luca; Priest, Virginia; Simmonds, Michael; Lee, Christa; Wasserman, Matthew

    2016-03-01

    To examine the cost-effectiveness of intravascular ultrasound (IVUS) use during percutaneous coronary intervention (PCI) with drug-eluting stents (DES) in treating coronary artery disease (CAD). A Markov model was constructed with a lifetime horizon to compare costs and health outcomes between IVUS-guided PCI and PCI guided solely by angiography from an Italian healthcare payer perspective. The population examined included CAD patients undergoing PCI with DES. From a healthcare payer perspective, the resulting incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year was negative in the base-case scenario (i.e., IVUS benefit assumed to persist beyond the first year). When IVUS benefit was assumed to be limited to the first year, the ICER increased to €9,624. This conclusion remained consistent even when scenarios varied regarding the duration of the device's effect. Furthermore, benefits of using IVUS were greater for patients with acute coronary syndrome, renal insufficiency, and diabetes. Using IVUS with angiography is a dominant strategy in Italy, and results demonstrate that it is desirable to target those at a greater risk of restenosis (i.e., patients with diabetes, chronic kidney disease, and acute coronary syndrome), who tend to benefit more from accurate stent implantation. Further information is necessary regarding the long-term benefits of IVUS, however sensitivity analysis presented in this research demonstrates a strong argument supporting the cost-effectiveness of IVUS.

  4. Real-time simulator for intravascular ultrasound (IVUS)

    NASA Astrophysics Data System (ADS)

    Abkai, Ciamak; Becherer, Nico; Hesser, Jürgen; Männer, Reinhard

    2007-03-01

    Intravascular Ultrasound (IVUS) plays a significant role in diagnostics of atherosclerotic diseases. Simulation of imaging techniques promises a better understanding of the physical background and segmentation strategies. Most simulation approaches describe ultrasonic backscattering using wave-equation based simplifications. More complicated real-time simulation techniques are not available so far. In this paper, we present an empirical model derived from wave-equations given by the Rayleigh integration method. According to boundary conditions and weak scatterers, a hybrid approach including the Beer-Lambert law to model attenuation is introduced. Scatterers are described by a 4D vessel-system model based on elastic tubes. Sophisticated discretization and numerical simplifications in addition to a highly optimized implementation of the model yields a real-time and realistic IVUS simulation with 20 frames/s on a 3.2 GHz Pentium 4 PC.

  5. Clinical applications of intravascular ultrasound (IVUS): experience from an academic high volume centre of Northern Greece.

    PubMed

    Mantziari, A; Ziakas, A; Stavropoulos, G; Styliadis, I H

    2011-01-01

    Intravascular ultrasound (IVUS) has become a valuable tool adjunctive to coronary angiography due to its ability to directly image atheroma and the vessel wall. We aimed to evaluate the use of IVUS during diagnostic angiography and coronary interventions in a coronary intervention academic high volume center of northern Greece. IVUS studies have been retrospectively retrieved from 2005 to 2008 from the archives of the catheterization laboratory of our department. IVUS was performed in 403 patients (294 male) of mean age 62±6 years. Indications for coronary angiography +/- intervention were acute coronary syndromes (49%), stable angina (46%) and previous coronary angioplasty evaluation (5%). Forty eight per cent of the IVUS studies were performed in left anterior descending artery (LAD), 25% in right coronary artery (RCA), 18% in left circumflex artery (LCx), and the rest (9%) in left main coronary artery (LMCA) or in coronary branches. Indications for performing an IVUS study were assessment of intermediate lesions (60%), evaluation of stent placement (36.5%), and determination of stent restenosis aetiology (3.5%). Among studies performed for assessment of intermediate lesions, 63% showed a non critical stenosis. IVUS after coronary stenting revealed a suboptimal stent placement in 77% of the cases, while in cases of stent restenosis, IVUS showed inadequate initial stent deployment in 43% of the patients. The use of IVUS in our department has contributed to the optimization of intervertional treatment of coronary lesions by means of evaluating borderline lesions, stenting placement and stent restenosis.

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

    PubMed

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

    2012-09-01

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

  7. Intravascular Ultrasound (IVUS): A Potential Arthroscopic Tool for Quantitative Assessment of Articular Cartilage.

    PubMed

    Huang, Yan-Ping; Zheng, Yong-Ping

    2009-06-26

    Conventional ultrasound examination of the articular cartilage performed externally on the body surface around the joint has limited accuracy due to the inadequacy in frequency used. In contrast to this, minimally invasive arthroscopy-based ultrasound with adequately high frequency may be a better alternative to assess the cartilage. Up to date, no special ultrasound transducer for imaging the cartilage in arthroscopic use has been designed. In this study, we introduced the intravascular ultrasound (IVUS) for this purpose. An IVUS system with a catheter-based probe (Ø approximately 1mm) was used to measure the thickness and surface acoustical reflection of the bovine patellar articular cartilage in vitro before and after degeneration induced by enzyme treatments. Similar measurement was performed using another high frequency ultrasound system (Vevo) with a probe of much larger size and the results were compared between the two systems. The thickness measured using IVUS was highly correlated (r = 0.985, p < 0.001) with that obtained by Vevo. Thickness and surface reflection amplitude measured using IVUS on the enzymatically digested articular cartilage showed changes similar to those obtained by Vevo, which were expectedly consistent with previous investigations. IVUS can be potentially used for the quantitative assessment of articular cartilage, with its ready-to-use arthroscopic feature.

  8. A histological and clinical comparison of new and conventional integrated backscatter intravascular ultrasound (IB-IVUS).

    PubMed

    Ohota, Masaya; Kawasaki, Masanori; Ismail, Tevfik F; Hattori, Kousuke; Serruys, Patrick W; Ozaki, Yukio

    2012-01-01

    While the utilization of integrated backscatter intravascular ultrasound (IB-IVUS) for the quantitative in vivo assessment of coronary plaque continues to grow, the validity of IB-IVUS images obtained from newly developed and conventional systems remains uncertain. To assess the accuracy and reliability of a newly developed IB-IVUS system (VISIWAVE) as compared to the conventional system (Clearview), we compared quantitative IB-IVUS plaque characteristics in the 2 systems using 125 post-mortem specimens from 26 coronary arteries in 11 cadavers, as well as using 200 clinical plaques in 32 patients undergoing coronary intervention. The overall agreement between the histological and IB-IVUS diagnoses using VISIWAVE (Cohen's κ=0.82, 95%CI: 0.73-0.90) was similar to that using Clearview (Cohen's κ=0.80, 95%CI: 0.71-0.89). The 2 systems also demonstrated comparably high sensitivity and specificity. In the direct comparison, the overall agreement between IB-IVUS diagnoses using VISIWAVE and Clearview was also excellent (Cohen's κ=0.87, 95%CI: 0.78-0.95). In the clinical comparison, measured plaque dimensions were similar (VISIWAVE: 8.27±3.46 mm(2) vs. Clearview; 8.31±3.46 mm(2), P=0.44) and there was strong concordance between both greyscale and IB-IVUS parameters. There was close agreement of analyzed results in both systems when compared with the gold standard of histology. Both systems are able to reliably and accurately characterize coronary plaque and thereby make a valuable contribution to our understanding of atherosclerosis.

  9. 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

  10. 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.

  11. Impact of gender and age on in vivo virtual histology-intravascular ultrasound imaging plaque characterization (from the global Virtual Histology Intravascular Ultrasound [VH-IVUS] registry).

    PubMed

    Qian, Jie; Maehara, Akiko; Mintz, Gary S; Margolis, M Pauliina; Lerman, Amir; Rogers, Jason; Banai, Shuel; Kazziha, Samer; Castellanos, Celia; Dani, Lokesh; Fahy, Martin; Stone, Gregg W; Leon, Martin B

    2009-05-01

    Virtual histology intravascular ultrasound (VH-IVUS) analyses were performed in the first 990 patients enrolled in the 3,000+ patient global VH-IVUS Registry to assess the impact of gender and age on in vivo VH-IVUS plaque characterization. The 990 patients were divided into 3 age group terciles (<58, 58 to 68, and >68 years) and again divided according to gender. In conclusion, (1) both women and men had an increase in plaque with increasing age; (2) at any age, men had more plaque than women; (3) percentages of dense calcium and necrotic core increased with increasing patient age in both men and women; and (4) gender differences were lowest in the oldest tercile (>68 years).

  12. Validating a bimodal intravascular ultrasound (IVUS) and near-infrared fluorescence (NIRF) catheter for atherosclerotic plaque detection in rabbits

    PubMed Central

    Abran, Maxime; Stähli, Barbara E.; Merlet, Nolwenn; Mihalache-Avram, Teodora; Mecteau, Mélanie; Rhéaume, Eric; Busseuil, David; Tardif, Jean-Claude; Lesage, Frédéric

    2015-01-01

    Coronary artery disease is characterized by atherosclerotic plaque formation. Despite impressive advances in intravascular imaging modalities, in vivo molecular plaque characterization remains challenging, and different multimodality imaging systems have been proposed. We validated an engineered bimodal intravascular ultrasound imaging (IVUS) / near-infrared fluorescence (NIRF) imaging catheter in vivo using a balloon injury atherosclerosis rabbit model. Rabbit aortas and right iliac arteries were scanned in vivo after indocyanine green (ICG) injection, and compared to corresponding ex vivo fluorescence and white light images. Areas of ICG accumulation were colocalized with macroscopic atherosclerotic plaque formation. In vivo imaging was performed with the bimodal catheter integrating ICG-induced fluorescence signals into cross-sectional IVUS imaging. In vivo ICG accumulation corresponded to ex vivo fluorescence signal intensity and IVUS identified plaques. PMID:26504648

  13. Validating a bimodal intravascular ultrasound (IVUS) and near-infrared fluorescence (NIRF) catheter for atherosclerotic plaque detection in rabbits.

    PubMed

    Abran, Maxime; Stähli, Barbara E; Merlet, Nolwenn; Mihalache-Avram, Teodora; Mecteau, Mélanie; Rhéaume, Eric; Busseuil, David; Tardif, Jean-Claude; Lesage, Frédéric

    2015-10-01

    Coronary artery disease is characterized by atherosclerotic plaque formation. Despite impressive advances in intravascular imaging modalities, in vivo molecular plaque characterization remains challenging, and different multimodality imaging systems have been proposed. We validated an engineered bimodal intravascular ultrasound imaging (IVUS) / near-infrared fluorescence (NIRF) imaging catheter in vivo using a balloon injury atherosclerosis rabbit model. Rabbit aortas and right iliac arteries were scanned in vivo after indocyanine green (ICG) injection, and compared to corresponding ex vivo fluorescence and white light images. Areas of ICG accumulation were colocalized with macroscopic atherosclerotic plaque formation. In vivo imaging was performed with the bimodal catheter integrating ICG-induced fluorescence signals into cross-sectional IVUS imaging. In vivo ICG accumulation corresponded to ex vivo fluorescence signal intensity and IVUS identified plaques.

  14. 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.

  15. The European Collaborative Project on Inflammation and Vascular Wall Remodeling in Atherosclerosis - Intravascular Ultrasound (ATHEROREMO-IVUS) Study.

    PubMed

    de Boer, Sanneke P M; Baran, Yael; Garcia-Garcia, Hector M; Eskin, Itamar; Lenzen, Mattie; Kleber, Marcus E; Regar, Evelyn; de Jaegere, Peter J; Ligthart, Jurgen M; van Geuns, Robert Jan; Lehtimäki, Tehro; Laaksonen, Reijo; Boersma, Eric; März, Winfried; Halperin, Erin; Serruys, Patrick W; Koenig, Wolfgang

    2017-09-26

    The European Collaborative Project on Inflammation and Vascular Wall Remodelling in Atherosclerosis - Intravascular Ultrasound (ATHEROREMO-IVUS) study has been designed as an exploratory clinical study to investigate the associations between genetic variation, coronary atherosclerosis phenotypes, and plaque vulnerability as determined by IVUS. The ATHEROREMO-IVUS study is a prospective, observational study of 581 patients with stable angina pectoris or acute coronary syndrome (ACS) who were referred for coronary angiography to the Thoraxcenter, Rotterdam, enriched with 265 IBIS-2 participants (total population, n=846). Prior to catheterization, blood samples were drawn for genetic analyses. During the catheterization procedure, IVUS was performed in a nonculprit coronary artery. The primary endpoint was the presence of vulnerable plaque as determined by IVUS virtual histology (VH). In addition, we performed a genome wide association study of plaque morphology. We observed strong signals associated with plaque morphology in several chromosomal regions: twelve SNPs (rs17300022, rs6904106, rs17177818, rs2248165, rs2477539, rs16865681, rs2396058, rs4753663, rs4082252, rs6932, rs12862206, rs6780676) in or near eight different genes (GNA12, NMBR, SFMBT2, CUL3, SESN3, SLC22A25, EFBN2, SEC62) were most significant. In conclusion, we found twelve SNPS in or in the proximity of eight genes, which were possibly associated with markers of vulnerable plaque.

  16. 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.

  17. Relation of genetic profile and novel circulating biomarkers with coronary plaque phenotype as determined by intravascular ultrasound: rationale and design of the ATHEROREMO-IVUS study.

    PubMed

    de Boer, Sanneke P M; Cheng, Jin M; Garcia-Garcia, Hector M; Oemrawsingh, Rohit M; van Geuns, Robert-Jan; Regar, Evelyn; Zijlstra, Felix; Laaksonen, Reijo; Halperin, Eran; Kleber, Marcus E; Koenig, Wolfgang; Boersma, Eric; Serruys, Patrick W

    2014-12-01

    The European Collaborative Project on Inflammation and Vascular Wall Remodeling in Atherosclerosis - Intravascular Ultrasound (ATHEROREMO-IVUS) study aims to investigate the relations of genetic profile and novel circulating biomarkers with coronary plaque phenotype and vulnerability as determined by intravascular ultrasound (IVUS). ATHEROREMO-IVUS is a prospective, observational cohort study of 846 patients with stable angina pectoris or acute coronary syndrome (ACS) who are referred for coronary angiography. Prior to the catheterisation procedure, blood samples are drawn for biomarker measurements and genetic analyses. During the catheterisation procedure, IVUS is performed in a non-culprit coronary artery. The primary endpoint is the presence of vulnerable plaque as determined by IVUS virtual histology. Secondary endpoints include the incidence of major adverse cardiac events during long-term follow-up. Results from ATHEROREMO-IVUS are expected to improve our knowledge of the role of genetic profile and circulating biomarkers in relation to the development of atherosclerosis and vulnerable plaques. Assessment and early validation of the prognostic value of novel biomarkers and intracoronary imaging techniques will be performed. (ClinicalTrials.gov number: NCT01789411).

  18. 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

  19. Automatic detection of blood versus non-blood regions on intravascular ultrasound (IVUS) images using wavelet packet signatures

    NASA Astrophysics Data System (ADS)

    Katouzian, Amin; Baseri, Babak; Konofagou, Elisa E.; Laine, Andrew F.

    2008-03-01

    Intravascular ultrasound (IVUS) has been proven a reliable imaging modality that is widely employed in cardiac interventional procedures. It can provide morphologic as well as pathologic information on the occluded plaques in the coronary arteries. In this paper, we present a new technique using wavelet packet analysis that differentiates between blood and non-blood regions on the IVUS images. We utilized the multi-channel texture segmentation algorithm based on the discrete wavelet packet frames (DWPF). A k-mean clustering algorithm was deployed to partition the extracted textural features into blood and non-blood in an unsupervised fashion. Finally, the geometric and statistical information of the segmented regions was used to estimate the closest set of pixels to the lumen border and a spline curve was fitted to the set. The presented algorithm may be helpful in delineating the lumen border automatically and more reliably prior to the process of plaque characterization, especially with 40 MHz transducers, where appearance of the red blood cells renders the border detection more challenging, even manually. Experimental results are shown and they are quantitatively compared with manually traced borders by an expert. It is concluded that our two dimensional (2-D) algorithm, which is independent of the cardiac and catheter motions performs well in both in-vivo and in-vitro cases.

  20. Intravascular ultrasound chirp imaging

    NASA Astrophysics Data System (ADS)

    Maresca, D.; Jansen, K.; Renaud, G.; van Soest, G.; Li, X.; Zhou, Q.; de Jong, N.; Shung, K. K.; van der Steen, A. F. W.

    2012-01-01

    We demonstrate the feasibility of intravascular ultrasound (IVUS) chirp imaging as well as chirp reversal ultrasound contrast imaging at intravascular ultrasound frequency. Chirp excitations were emitted with a 34 MHz single crystal intravascular transducer and compared to conventional Gaussian-shaped pulses of equal acoustic pressure. The signal to noise ratio of the chirp images was increased by up to 9 dB relative to the conventional images. Imaging of contrast microbubbles was implemented by chirp reversal, achieving a contrast to tissue ratio of 12 dB. The method shows potential for intravascular imaging of structures in and beyond coronary atherosclerotic plaques including vasa vasorum.

  1. Plaque REgression with Cholesterol absorption Inhibitor or Synthesis inhibitor Evaluated by IntraVascular UltraSound (PRECISE-IVUS Trial): Study protocol for a randomized controlled trial.

    PubMed

    Tsujita, Kenichi; Sugiyama, Seigo; Sumida, Hitoshi; Shimomura, Hideki; Yamashita, Takuro; Yamanaga, Kenshi; Komura, Naohiro; Sakamoto, Kenji; Ono, Takamichi; Oka, Hideki; Nakao, Koichi; Nakamura, Sunao; Ishihara, Masaharu; Matsui, Kunihiko; Sakaino, Naritsugu; Nakamura, Natsuki; Yamamoto, Nobuyasu; Koide, Shunichi; Matsumura, Toshiyuki; Fujimoto, Kazuteru; Tsunoda, Ryusuke; Morikami, Yasuhiro; Matsuyama, Koushi; Oshima, Shuichi; Kaikita, Koichi; Hokimoto, Seiji; Ogawa, Hisao

    2015-10-01

    Although the positive association between achieved low-density lipoprotein cholesterol (LDL-C) level and the risk of coronary artery disease (CAD) has been confirmed by randomized studies with statins, many patients remain at high residual risk of events suggesting the necessity of novel pharmacologic strategies. The combination of ezetimibe/statin produces greater reductions in LDL-C compared to statin monotherapy. The Plaque REgression with Cholesterol absorption Inhibitor or Synthesis inhibitor Evaluated by IntraVascular UltraSound (PRECISE-IVUS) trial was aimed at evaluating the effects of ezetimibe addition to atorvastatin, compared with atorvastatin monotherapy, on coronary plaque regression and change in lipid profile in patients with CAD. The study is a prospective, randomized, controlled, multicenter study. The eligible patients undergoing IVUS-guided percutaneous coronary intervention will be randomly assigned to receive either atorvastatin alone or atorvastatin plus ezetimibe (10 mg) daily using a web-based randomization software. The dosage of atorvastatin will be increased by titration within the usual dose range with a treatment goal of lowering LDL-C below 70 mg/dL based on consecutive measures of LDL-C at follow-up visits. IVUS will be performed at baseline and 9-12 months follow-up time point at participating cardiovascular centers. The primary endpoint will be the nominal change in percent coronary atheroma volume measured by volumetric IVUS analysis. PRECISE-IVUS will assess whether the efficacy of combination of ezetimibe/atorvastatin is noninferior to atorvastatin monotherapy for coronary plaque reduction, and will translate into increased clinical benefit of dual lipid-lowering strategy in a Japanese population. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  2. Effect of Intravascular Ultrasound-Guided vs Angiography-Guided Everolimus-Eluting Stent Implantation: The IVUS-XPL Randomized Clinical Trial.

    PubMed

    Hong, Sung-Jin; Kim, Byeong-Keuk; Shin, Dong-Ho; Nam, Chung-Mo; Kim, Jung-Sun; Ko, Young-Guk; Choi, Donghoon; Kang, Tae-Soo; Kang, Woong-Chol; Her, Ae-Young; Kim, Yong Hoon; Kim, Yonghoon; Hur, Seung-Ho; Hong, Bum-Kee; Kwon, Hyuckmoon; Jang, Yangsoo; Hong, Myeong-Ki

    2015-11-24

    Use of intravascular ultrasound (IVUS) promotes better clinical outcomes for coronary intervention in complex coronary lesions. However, randomized data demonstrating the clinical usefulness of IVUS are limited for lesions treated with drug-eluting stents. To determine whether the long-term clinical outcomes with IVUS-guided drug-eluting stent implantation are superior to those with angiography-guided implantation in patients with long coronary lesions. The Impact of Intravascular Ultrasound Guidance on Outcomes of Xience Prime Stents in Long Lesions (IVUS-XPL) randomized, multicenter trial was conducted in 1400 patients with long coronary lesions (implanted stent ≥28 mm in length) between October 2010 and July 2014 at 20 centers in Korea. Patients were randomly assigned to receive IVUS-guided (n = 700) or angiography-guided (n = 700) everolimus-eluting stent implantation. Primary outcome measure was the composite of major adverse cardiac events, including cardiac death, target lesion-related myocardial infarction, or ischemia-driven target lesion revascularization at 1 year, analyzed by intention-to-treat. One-year follow-up was complete in 1323 patients (94.5%). Major adverse cardiac events at 1 year occurred in 19 patients (2.9%) undergoing IVUS-guided and in 39 patients (5.8%) undergoing angiography-guided stent implantation (absolute difference, -2.97% [95% CI, -5.14% to -0.79%]) (hazard ratio [HR], 0.48 [95% CI, 0.28 to 0.83], P = .007). The difference was driven by a lower risk of ischemia-driven target lesion revascularization in patients undergoing IVUS-guided (17 [2.5%]) compared with angiography-guided (33 [5.0%]) stent implantation (HR, 0.51 [95% CI, 0.28 to 0.91], P = .02). Cardiac death and target lesion-related myocardial infarction were not significantly different between the 2 groups. For cardiac death, there were 3 patients (0.4%) in the IVUS-guided group and 5 patients (0.7%) in the angiography-guided group (HR, 0.60 [95% CI, 0

  3. Fluorescence lifetime intravascular ultrasound (FLIm-IVUS) and the quest to discriminate between early and advanced lipid cores in atherosclerosis (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Phipps, Jennifer E.; Bec, Julien; Vela, Deborah; Buja, L. Maximilian; Southard, Jeffrey A.; Margulies, Kenneth B.; Marcu, Laura

    2017-02-01

    FL-IVUS combines intravascular ultrasound with fluorescence lifetime imaging to obtain morphologic and biochemical details from the arterial wall. Ultrasound measurements alone provide morphologic information (plaque burden, remodeling index and presence of calcium). Fluorescence lifetime can determine the presence of a thick fibrous cap, macrophage infiltration, and lipid cores beneath thin fibrous caps. These details are important to assess plaque vulnerability. In this study, we focused on the ability of FL-IVUS to differentiate between early and advanced lipid cores-advanced cores are vulnerable to rupture. We imaged N=12 ex vivo human coronary arteries and performed hematoxylin and eosin, Movat's pentachrome and CD68 immunohistochemistry at 500 micron intervals throughout the length of the vessels. We found only N=1 thin-capped fibroatheroma (TCFA) with an advanced necrotic core and N=7 cases of foam cell infiltration, early lipid cores or deep necrotic cores. IVUS was able to observe the increased plaque burden and calcification of the advanced and deep necrotic cores, but could not identify early lipid cores, foam cell infiltration or discriminate between deep necrotic cores and TCFA. The addition of FLIm to IVUS allowed the TCFA to be discriminated from early lipid accumulation, particularly at 542+/-50 nm (355 nm pulsed excitation): 7.6 +/- 0.5 ns compared to 6.6 +/- 0.4 ns, respectively (P<0.001 by ANOVA analysis). These differences need to be validated in a larger cohort, but exist due to specific lipid content in the necrotic core as well as increased extracellular matrix in early lesions.

  4. Diagnostic accuracy of intravascular ultrasound-derived minimal lumen area compared with fractional flow reserve--meta-analysis: pooled accuracy of IVUS luminal area versus FFR.

    PubMed

    Nascimento, Bruno R; de Sousa, Marcos R; Koo, Bon-Kwon; Samady, Habib; Bezerra, Hiram G; Ribeiro, Antônio L P; Costa, Marco A

    2014-09-01

    Although intravascular ultrasound minimal luminal area (IVUS-MLA) is one of many anatomic determinants of lesion severity, it has been proposed as an alternative to fractional flow reserve (FFR) to assess severity of coronary artery disease. Pool the diagnostic performance of IVUS-MLA and determine its overall accuracy to predict the functional significance of coronary disease using FFR (0.75 or 0.80) as the gold standard. Studies comparing IVUS and FFR to establish the best MLA cutoff value that correlates with significant coronary stenosis were reviewed from a Medline search using the terms "fractional flow reserve" and "ultrasound." DerSimonian Laird method was applied to obtain pooled accuracy. Eleven clinical trials, including two left main (LM) trials (total N = 1,759 patients, 1,953 lesions) were included. The weighted overall mean MLA cutoff was 2.61 mm(2) in non-LM trials and 5.35 mm(2) in LM trials. For non-LM lesions, the pooled sensitivity of MLA was 0.79 (95% CI = 0.76-0.83) and specificity was 0.65 (95% CI = 0.62-0.67). Positive likelihood ratio (LR) was 2.26 (95% CI = 1.98-2.57) and LR- was 0.32 (95% CI = 0.24-0.44). Area under the summary receiver operator curve for all trials was 0.848. Pooled LM trials had better accuracy: sensitivity = 0.90, specificity = 0.90, LR+ = 8.79, and LR- = 0.120. Given its limited pooled accuracy, IVUS-MLA's impact on clinical decision in this scenario is low and may lead to misclassification in up to 20% of the lesions. Pooled analysis points toward lower MLA cutoffs than the ones used in current practice. © 2013 Wiley Periodicals, Inc.

  5. Intravascular ultrasound elastography.

    PubMed

    van der Steen, A F; de Korte, C L; Céspedes, E I

    1998-10-01

    Intravascular Ultrasound Blastography. The response of a tissue to mechanical excitation is a function of its mechanical properties. Excitation can be dynamic or quasistatic in nature. The response (e.g. displacement, velocity, compression) can be measured via ultrasound. This is the main principle underlying ultrasound elasticity imaging, sonoelasticity imaging, or ultrasound elastography. It is of great interest to know the local hardness of vessel wall and plaques. Intravascular elastography yields information unavailable or inconclusive if obtained from IVUS alone and thus contributes to more correct diagnosis. Potentially it can be used for therapy guidance. During the last decade several working groups used elastography in intravascular applications with varying success. In this paper we discuss the various approaches by different working groups. Focus will be on the approach of the Rotterdam group. Using a 30 MHz IVUS catheter, RF data are acquired from vessels in vitro at different intraluminal pressures. Local tissue displacement estimation by cross-correlation is followed by computation of the local strain. The resulting image supplies local information on the elastic properties of the vessel and plaque with high spatial resolution. Feasibility and usefulness are shown by means of phantom measurements. Furthermore, initial in vitro results of femoral arteries and correlation with histology are discussed. Phantom data show that the elastograms reveal information not presented by the echogram. In vitro artery data prove that in principle elastography is capable of identifying plaque composition where echography fails.

  6. In vivo detection of high-risk coronary plaques by radiofrequency intravascular ultrasound and cardiovascular outcome: results of the ATHEROREMO-IVUS study.

    PubMed

    Cheng, Jin M; Garcia-Garcia, Hector M; de Boer, Sanneke P M; Kardys, Isabella; Heo, Jung Ho; Akkerhuis, K Martijn; Oemrawsingh, Rohit M; van Domburg, Ron T; Ligthart, Jurgen; Witberg, Karen T; Regar, Evelyn; Serruys, Patrick W; van Geuns, Robert-Jan; Boersma, Eric

    2014-03-01

    Acute coronary syndromes (ACS) are mostly caused by plaque rupture. This study aims to investigate the prognostic value of in vivo detection of high-risk coronary plaques by intravascular ultrasound (IVUS) in patients undergoing coronary angiography. Between November 2008 and January 2011, IVUS of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography for ACS (n = 318) or stable angina (n = 263). Primary endpoint was major adverse cardiac events (MACEs) defined as mortality, ACS, or unplanned coronary revascularization. Culprit lesion-related events were not counted. Cumulative Kaplan-Meier incidence of 1-year MACE was 7.8%. The presence of IVUS virtual histology-derived thin-cap fibroatheroma (TCFA) lesions (present 10.8% vs. absent 5.6%; adjusted HR: 1.98, 95% CI: 1.09-3.60; P = 0.026) and lesions with a plaque burden of ≥70% (present 16.2% vs. absent 5.5%; adjusted HR: 2.90, 95% CI: 1.60-5.25; P < 0.001) were independently associated with a higher MACE rate. Thin-cap fibroatheroma lesions were also independently associated with the composite of death or ACS only (present 7.5% vs. absent 3.0%; adjusted HR: 2.51, 95% CI: 1.15-5.49; P = 0.021). Thin-cap fibroatheroma lesions with a plaque burden of ≥70% were associated with a higher MACE rate within (P = 0.011) and after (P < 0.001) 6 months of follow-up, while smaller TCFA lesions were only associated with a higher MACE rate after 6 months (P = 0.033). In patients undergoing coronary angiography, the presence of IVUS virtual histology-derived TCFA lesions in a non-culprit coronary artery is strongly and independently predictive for the occurrence of MACE within 1 year, particularly of death and ACS. Thin-cap fibroatheroma lesions with a large plaque burden carry higher risk than small TCFA lesions, especially on the short term.

  7. Plasma cystatin C and neutrophil gelatinase-associated lipocalin in relation to coronary atherosclerosis on intravascular ultrasound and cardiovascular outcome: Impact of kidney function (ATHEROREMO-IVUS study).

    PubMed

    Brankovic, Milos; Akkerhuis, K Martijn; Buljubasic, Nermina; Cheng, Jin M; Oemrawsingh, Rohit M; Garcia-Garcia, Hector M; Regar, Evelyn; Serruys, Patrick W; van Geuns, Robert-Jan; Boersma, Eric; Kardys, Isabella

    2016-11-01

    We investigated whether plasma cystatin C (CysC) and neutrophil gelatinase-associated lipocalin (NGAL) are associated with intravascular ultrasound (IVUS)-derived characteristics of coronary atherosclerosis and 1-year adverse coronary events in patients with normal and mildly-to-moderately impaired kidney function. Between 2008 and 2011, virtual histology (VH)-IVUS of a non-culprit coronary artery was performed in 581 patients undergoing coronary angiography. Creatinine, CysC and NGAL were measured in pre-procedural blood samples. Presence of VH-IVUS-derived thin-cap fibroatheroma (TCFA) lesions, lesions with plaque burden (PB)≥70% and lesions with minimal luminal area (MLA)≤4 mm(2) was assessed. Major adverse coronary events (MACE) comprised the composite of all-cause mortality, acute coronary syndrome, or unplanned coronary revascularization. Analyses were stratified using eGFRCr of 90 ml/min/1.73 m(2) as the cut-off. In patients with normal kidney function, those with higher CysC levels had fewer lesions with PB ≥ 70% and fewer VH-TCFA lesions (adjusted odds ratios (ORs) and 95% confidence intervals (CIs): 0.46 [0.30-0.69] and 0.59 [0.44-0.83], respectively, per standard deviation (SD) ln[ng/mL] CysC). Those with higher NGAL levels also had fewer lesions with PB ≥ 70% (adjusted OR [95% CI]:0.49 [0.29-0.82]) In patients with impaired kidneys, no differences in high-risk lesions were observed for CysC or NGAL. However, those with higher CysC had higher risk of MACE (hazard ratio (HR):1.4, 95% CI [1.03-1.92]). This was not the case in patients with normal kidney function. NGAL did not influence risk of MACE. Mild-to-moderate kidney dysfunction modifies the relationship between CysC and high-risk coronary lesions. This has not been established before, and offers an explanation for the difference in findings between experimental and epidemiologic studies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Intravascular Ultrasound

    MedlinePlus

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

    PubMed

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

    2014-11-01

    The aim of this study was to evaluate the impact of intravascular ultrasound (IVUS) guidance on the final volume of contrast agent used in patients undergoing percutaneous coronary intervention (PCI). To date, few approaches have been described to reduce the final dose of contrast agent in PCIs. We hypothesized that IVUS might serve as an alternative imaging tool to angiography in many steps during PCI, thereby reducing the use of iodine contrast. A total of 83 patients were randomized to angiography-guided PCI or IVUS-guided PCI; both groups were treated according to a pre-defined meticulous procedural strategy. The primary endpoint was the total volume contrast agent used during PCI. Patients were followed clinically for an average of 4 months. The median total volume of contrast was 64.5 ml (interquartile range [IQR]: 42.8 to 97.0 ml; minimum, 19 ml; maximum, 170 ml) in the angiography-guided group versus 20.0 ml (IQR: 12.5 to 30.0 ml; minimum, 3 ml; maximum, 54 ml) in the IVUS-guided group (p < 0.001). Similarly, the median volume of contrast/creatinine clearance ratio was significantly lower among patients treated with IVUS-guided PCI (1.0 [IQR: 0.6 to 1.9] vs. 0.4 [IQR: 0.2 to 0.6, respectively; p < 0.001). In-hospital and 4-month outcomes were not different between patients randomized to angiography-guided and IVUS-guided PCI. Thoughtful and extensive use of IVUS as the primary imaging tool to guide PCI is safe and markedly reduces the volume of iodine contrast compared with angiography-alone guidance. The use of IVUS should be considered for patients at high risk of contrast-induced acute kidney injury or volume overload undergoing coronary angioplasty. (Minimizing cOntrast utiliZation With IVUS Guidance in coRonary angioplasTy [MOZART]; NCT01947335). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. Development of a combined intravascular ultrasound and photoacoustic imaging system

    NASA Astrophysics Data System (ADS)

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

    2006-02-01

    Intravascular ultrasound (IVUS) imaging has emerged as an imaging technique to evaluate coronary artery diseases including vulnerable plaques. However, in addition to the morphological characteristics provided by IVUS imaging, there is a need for functional imaging capability that could identify the composition of vulnerable plaques. Intravascular photoacoustic (IVPA) imaging, in conjunction with clinically available IVUS imaging, may be such a technique allowing vulnerable plaque characterization and differentiation. We have developed an integrated intravascular ultrasound and photoacoustic imaging system to visualize clinically relevant structural and functional properties of the coronary arteries. The performance of the combined IVUS and IVPA imaging system was evaluated through images of arterial phantoms. Experiments were performed using high frequency IVUS imaging catheters operating at 20 MHz, 30 MHz and 40 MHz. The IVPA imaging was successful in highlighting inclusions based on differential optical absorption while these lesions did not have sufficient contrast in the IVUS images. Finally, initial IVUS and IVPA imaging studies were performed on ex vivo samples of a rabbit artery using the 40 MHz IVUS imaging catheter. Results of the above studies demonstrate the feasibility of combining intravascular ultrasound and photoacoustic imaging and suggest clinical utility of the developed imaging system in interventional cardiology.

  11. Combined intravascular photoacoustic and ultrasound imaging imaging of atherosclerotic calcification in human artery

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Li, Xiang; Zhou, Qifa; Shung, K. Kirk; Chen, Zhongping

    2012-03-01

    Intravascular ultrasound (IVUS) is mature imaging modality to diagnose blood vessel disease, especially for calcification characterization. Based on the intrinsic optical absorption, intravascular photoacoustic (IVPA) works as a complementary method to IVUS. In this paper, we develop a miniature intravascular probe combined photoacoustic and ultrasound imaging. The optical components and ultrasound transducer were integrated to achieve internal illumination. Atherosclerotic human artery was imaged ex vivo, which demonstrates the imaging ability of the multi-functional probe and illustrate its clinical potential.

  12. Heterogeneous Intravascular Ultrasound Findings of Stent Thrombosis

    PubMed Central

    Morofuji, Toru; Inaba, Shinji; Aisu, Hiroe; Takahashi, Kayo; Saito, Makoto; Higashi, Haruhiko; Yoshii, Toyofumi; Sumimoto, Takumi

    2017-01-01

    Objective The underlying mechanisms of stent thrombosis are not completely understood. Methods We experienced 12 definite stent thrombosis cases (1 early, 1 late, and 10 very late) at our hospital from July 2011 to April 2016 and evaluated the possible causes of stent thrombosis by intravascular ultrasound (IVUS). Results Five different potential morphological causes of stent thrombosis (neoatherosclerosis, stent malapposition, stent fracture, edge dissection, and stent underexpansion) were detected by IVUS in 10 cases (83.3%); in 1 of the remaining 2 cases, the discontinuation of antithrombotic drugs resulted in early stent thrombosis without abnormal IVUS findings. Of the 12 stent thrombosis cases, 4 occurred at a bare-metal stent (average time from stent implantation, 106 months); in all 12, significant neointimal hyperplasia was observed on IVUS, and 2 had plaque ruptures at an in-stent or proximal reference. Malapposed stent struts were observed in three very-late stent thromboses, and all of these underwent sirolimus-eluting stent implantation. Stent thrombosis due to mechanical (stent fracture) or procedure-related complications (edge dissection and stent underexpansion) was observed in three cases. Conclusion In patients with stent thrombosis, heterogeneous findings were observed in IVUS. This IVUS case series illustrates the possible mechanisms of stent thrombosis. PMID:28154268

  13. Intravascular ultrasound tissue harmonic imaging in vivo.

    PubMed

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

    2006-10-01

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

  14. Intravascular ultrasound imaging

    SciTech Connect

    Cavaye, D.M.; White, R.A. )

    1992-01-01

    This book will give vascular surgeons, cardiologists, radiologists, and technologists a complete working knowledge of intravascular ultrasound imaging and the crucial role of this new technology in endovascular diagnosis and therapy. The book reviews the essential principles of vascular pathology and ultrasound imaging and then provides state-of-the-art information on intraluminal ultrasound imaging devices and techniques, including practical guidelines for using catheters, optimizing image quality, and avoiding artifacts. Image interpretation and computerized image reconstruction are also discussed in detail. The first section explains the diagnostic, therapeutic, and experimental applications of intravascular ultrasound, particularly as a adjunct to angioplasty and other current interventional procedures.

  15. 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.

  16. 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.

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

    PubMed

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

    2016-04-01

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

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

    PubMed Central

    Chotai, Shayna; Khokhar, Azhar A.; Kelly, Paul A.

    2016-01-01

    Hazy lesions in coronary angiography can often be a puzzle for the interventional cardiologist. Recanalized chronic coronary thrombus, although rare, is one of the potential diagnoses. Intracoronary imaging with intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are tools that can guide to the correct diagnosis. We present the images of a case where IVUS was used to unravel such a lesion. PMID:27054109

  19. 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.

  20. Micromachined capacitive transducer arrays for intravascular ultrasound

    NASA Astrophysics Data System (ADS)

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

    2005-01-01

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

  1. Integrated catheter for intravascular ultrasound and photoacoustic imaging

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    The vulnerability of atherosclerotic plaques that are formed in the arterial walls due to atherosclerosis depends on both their distribution and composition. The distribution of the plaques can be imaged using an intravascular ultrasound (IVUS) imaging which is a clinically approved minimally-invasive method. The recently introduced intravascular photoacoustic (IVPA) imaging may be used to obtain the necessary information about the composition of the plaques. Previous studies using excised rabbit arteries have demonstrated that the combined IVUS/IVPA imaging may simultaneously provide the morphology and functional information of plaques. However, for in-vivo IVUS/IVPA imaging, an integrated IVUS/IVPA imaging catheter capable both of delivering light into a vessel lumen with consequent detection of photoacoustic transients and of probing the arterial walls in pulse-echo mode is required. In the current study, an advanced prototype of the integrated IVUS/IVPA imaging catheter based on a 40-MHz single-element ultrasound transducer and a 600-μm-core single optical fiber is introduced. Unlike previously reported prototypes, the current integrated IVUS/IVPA imaging catheter is capable of cross-sectional imaging of vessel walls via mechanical rotation of the catheter. The performance of the integrated IVUS/IVPA catheter was evaluated in tissue-mimicking phantoms with and without the presence of blood in a lumen. The results of our study suggest that the approach used to develop integrated IVUS/IVPA imaging catheter can be successfully translated to the clinical environment for in-vivo combined IVUS/IVPA imaging.

  2. 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.

  3. 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.

  4. FD-OCT and IVUS intravascular imaging modalities in peripheral vasculature.

    PubMed

    Spiliopoulos, S; Kitrou, P; Katsanos, K; Karnabatidis, D

    2017-02-01

    Intra-Vascular Ultra-Sound (IVUS) and Frequency Domain-Optical Coherence Tomography (FD-OCT), in vivo, intra-vascular, imaging modalities, widely used in the field of coronary disease, have been recently implemented in peripheral endovascular procedures, for procedural assessment, plaque characterization and determination of predictors of treatment outcomes. Their unique characteristics have also been used in order to provide additional features and improve the performance of re-entry devices and atherotomes. Areas covered: Present review focuses on available literature regarding these two promising imaging technologies in the peripheral vasculature, highlighting the added value produced by their use in endovascular therapy, their limitations and their utilization in new endovascular devices. Authors also provide their future perspective and the possible benefits in understanding vascular behavior and lesion characterization in peripheral endovascular interventions. Expert commentary: By providing both quantitative but also qualitative data on vessel and lesion morphology, intravascular imaging modalities offer a valid solution for endovascular treatment evaluation and outcome presentation homogeneity.

  5. Feasibility of in vivo intravascular photoacoustic imaging using integrated ultrasound and photoacoustic imaging catheter

    NASA Astrophysics Data System (ADS)

    Karpiouk, Andrei B.; Wang, Bo; Amirian, James; Smalling, Richard W.; Emelianov, Stanislav Y.

    2012-09-01

    Pilot studies of in vivo combined intravascular ultrasound (IVUS) and intravascular photoacoustic (IVPA) imaging are reported. A recently introduced prototype of an integrated IVUS/IVPA imaging catheter consisting of a single-element ultrasound transducer and a light delivery system based on a single optical fiber was adapted and used for in vivo imaging of a coronary stent deployed in a rabbit's thoracic aorta in the presence of luminal blood. The results suggest that in vivo IVUS/IVPA imaging is feasible using the integrated IVUS/IVPA imaging catheter. The challenges of in vivo combined IVUS/IVPA imaging are discussed, and further improvements on the design of the catheter and the clinical imaging system are proposed.

  6. 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

    2016-09-20

    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.

  7. 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.

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

    PubMed

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

    2017-03-01

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

  9. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

  11. Comparison of Angiography and Intravascular Ultrasound Before and After Balloon Angioplasty of the Femoropopliteal Artery

    SciTech Connect

    Lankeren, Winnifred van; Gussenhoven, Elma J.; Pieterman, Herman; Sambeek, Marc R.H.M. van; Lugt, Aad van der

    1998-09-15

    Purpose: To compare angiographic and intravascular ultrasound (IVUS) data before and after balloon angioplasty (PTA) of the femoropopliteal artery. Methods: Qualitative and quantitative analyses were performed on corresponding angiographic and IVUS levels obtained from 135 patients. Results: IVUS detected more lesions, calcified lesions, and vascular damage than angiography. Sensitivity of angiography was good for the presence of a lesion (84%), moderate for eccentric lesions (53%) and for vascular damage (52%), and poor for calcified lesions (30%). The increase in angiographic diameter stenosis was associated with a decrease in lumen area and increase in percentage area stenosis on IVUS. Conclusions: Angiography is less sensitive than IVUS for detecting lesion eccentricity, calcified lesions, and vascular damage. Presence of a lesion and amount of plaque were underestimated angiographically. Only before PTA was good agreement found between angiographic diameter stenosis and lumen size on IVUS.

  12. Intravascular Ultrasound Characterization of a Tissue-Engineered Vascular Graft in an Ovine Model.

    PubMed

    Pepper, Victoria K; Clark, Elizabeth S; Best, Cameron A; Onwuka, Ekene A; Sugiura, Tadahisa; Heuer, Eric D; Moko, Lilamarie E; Miyamoto, Shinka; Miyachi, Hideki; Berman, Darren P; Cheatham, Sharon L; Chisolm, Joanne L; Shinoka, Toshiharu; Breuer, Christopher K; Cheatham, John P

    2017-04-01

    Patients who undergo implantation of a tissue-engineered vascular graft (TEVG) for congenital cardiac anomalies are monitored with echocardiography, followed by magnetic resonance imaging or angiography when indicated. While these methods provide data regarding the lumen, minimal information regarding neotissue formation is obtained. Intravascular ultrasound (IVUS) has previously been used in a variety of conditions to evaluate the vessel wall. The purpose of this study was to evaluate the utility of IVUS for evaluation of TEVGs in our ovine model. Eight sheep underwent implantation of TEVGs either unseeded or seeded with bone marrow-derived mononuclear cells. Angiography, IVUS, and histology were directly compared. Endothelium, tunica media, and graft were identifiable on IVUS and histology at multiple time points. There was strong agreement between IVUS and angiography for evaluation of luminal diameter. IVUS offers a valuable tool to evaluate the changes within TEVGs, and clinical translation of this application is warranted.

  13. 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.

  14. Fast treatment planning with IVUS imaging in intravascular brachytherapy

    NASA Astrophysics Data System (ADS)

    Novario, Raffaele; Bianchi, Carla; Lorusso, Rita; Sampietro, Chiara; Tanzi, Fabio; Conte, Leopoldo; Vescovi, Mario; Caccia, Massimo; Alemi, Mario; Cappellini, Chiara

    2004-05-01

    The planned target volume in intracoronary brachytherapy is the vessel wall. The success of the treatment is based on the need of delivering doses possibly not lower than 8 and not higher than 30 Gy. An automatic procedure in order to acquire intravascular ultrasound images of the whole volume to be irradiated is pointed out; a motor driven pullback device, with velocity of the catheter of 0.5 and 1 mm/s allows to acquire the entire target volume of the vessel with a number of slices normally ranging from 400 to 1600. A semiautomatic segmentation and classification of the different structures in each slice of the vessel is proposed. The segmentation and the classification of the structures allows the calculation of their volume; this is very useful in particular for plaque volume assessment in the follow-up of the patients. A 3D analyser tool was developed in order to visualize the walls and the lumen of the vessel. The knowledge, for each axial slice, of the position of the source (in the centre of the catheter) and the position of the target (vessel walls) allows the calculation of a set of source-target distances. Given a time of irradiation, and a type of source a dose volume histogram (DVH) describing the distribution of the doses in the whole target can be obtained. The whole procedure takes few minutes and then is compatible with a safe treatment of the patient, giving an important indication about the quality of the radiation treatment selected.

  15. 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.

  16. 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.

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

    PubMed Central

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

    2012-01-01

    Abstract. 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. PMID:23224011

  18. Development of a catheter for combined intravascular ultrasound and photoacoustic imaging

    NASA Astrophysics Data System (ADS)

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

    2010-01-01

    Atherosclerosis is characterized by formation and development of the plaques in the inner layer of the vessel wall. To detect and characterize atherosclerotic plaques, we previously introduced the combined intravascular ultrasound (IVUS) and intravascular photoacoustic (IVPA) imaging capable of assessing plaque morphology and composition. The utility of IVUS/IVPA imaging has been demonstrated by imaging tissue-mimicking phantoms and ex vivo arterial samples using laboratory prototype of the imaging system. However, the clinical realization of a IVUS/IVPA imaging requires an integrated intravascular imaging catheter. In this paper, two designs of IVUS/IVPA imaging catheters—side fire fiber-based and mirror-based catheters—are reported. A commercially available IVUS imaging catheter was utilized for both pulse-echo ultrasound imaging and detection of photoacoustic transients. Laser pulses were delivered by custom-designed fiber-based optical systems. The optical fiber and IVUS imaging catheter were combined into a single device. Both designs were tested and compared using point targets and tissue-mimicking phantoms. The results indicate applicability of the proposed catheters for clinical use.

  19. Co-registration of angiography and intravascular ultrasound images through image-based device tracking.

    PubMed

    Prasad, Megha; Cassar, Andrew; Fetterly, Kenneth A; Bell, Malcolm; Theessen, Heike; Ecabert, Olivier; Bresnahan, John F; Lerman, Amir

    2016-12-01

    To determine the feasibility of automated co-registration of angiography and intravascular ultrasound (IVUS) to facilitate integration of these two imaging modalities in a synchronous manner. IVUS provides cross-sectional imaging of coronary arteries but lacks overview of the vascular territory provided by angiography. Co-registration of angiography and IVUS would increase utility of IVUS in the clinical setting. Forty-nine consecutive patients undergoing surveillance for cardiac allograft vasculopathy with angiography and IVUS of the left anterior descending artery (LAD) were enrolled. A pre-IVUS angiogram of the LAD was performed followed by an ECG-triggered fluoroscopy (ECGTF) during IVUS pullback at 0.5 mm/s using an automatic pullback device. ECGTF was used to track the IVUS catheter during pullback and establish a spatial relationship to the pre-IVUS angiogram. Angio-IVUS co-registration was performed with a research prototype (Siemens Healthcare, Germany) and accuracy was evaluated by distance mismatch between angiography and IVUS images at vessel bifurcations. Median age was 54 (44.5, 67) years. The population was 82.6% male with minimal risk factors. The median (IQR) co-registration distance mismatch measured at 108 bifurcations in 42 (85%) patients was 0.35 (0.00-1.16) mm. Seven patients were excluded due to inappropriate data acquisition (n = 3) and failure of tracking (n = 4), e.g., due to overlapping sternal wires. Estimated effective radiation dose for ECGTF was 0.09 mSv. This study demonstrates the feasibility of angio-IVUS co-registration which may be used as a clinical tool for localizing IVUS cross-sections along an angiographic roadmap. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  20. 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).

  1. In Vivo Calcium Detection by Comparing Optical Coherence Tomography, Intravascular Ultrasound, and Angiography.

    PubMed

    Wang, Xiao; Matsumura, Mitsuaki; Mintz, Gary S; Lee, Tetsumin; Zhang, Wenbin; Cao, Yang; Fujino, Akiko; Lin, Yongqing; Usui, Eisuke; Kanaji, Yoshihisa; Murai, Tadashi; Yonetsu, Taishi; Kakuta, Tsunekazu; Maehara, Akiko

    2017-08-01

    The aim of this study was to evaluate optical coherence tomography (OCT) and intravascular ultrasound (IVUS) versus coronary angiography in the assessment of target lesion calcification and its effect on stent expansion. IVUS is more sensitive than angiography in the detection of coronary artery calcium, but the relationship among IVUS, OCT, and angiography has not been studied. Overall, 440 lesions (440 patients with stable angina) underwent OCT- and IVUS-guided stent implantation. Coronary calcification was evaluated using: 1) angiography; 2) IVUS (maximum calcium angle and the surface pattern); and 3) OCT (mean and maximum calcium angle, calcium length, and maximum calcium thickness). Median patient age was 66 years, and 82.5% were men. Among 440 lesions, calcium was detected by angiography in 40.2%, IVUS in 82.7%, and OCT in 76.8%. The maximum calcium angle, maximum calcium thickness, and calcium length by OCT or IVUS increased in relation to the increasing severity of angiographically visible calcium. In 13.2% of lesions with IVUS-detected calcium, calcium was either not visible or was underestimated (>90° smaller maximum arc) by OCT mostly due to superficial OCT plaque attenuation. In 21.6% of lesions with IVUS calcium angle >180°, angiography did not detect any calcium; these lesions had thinner and shorter calcium deposits as assessed using OCT, and final minimum stent area was larger compared to those with angiographically visible calcium. In lesions with thinner calcium deposits by OCT, IVUS detected a smooth surface with reverberations whereas thick calcium deposits were associated with an irregular surface without reverberations. Angiographic detection of target lesion coronary calcium (compared to intravascular imaging) has not changed in the past 2 decades, and angiographically invisible calcium (only detectable by IVUS or OCT) did not appear to inhibit stent expansion. Copyright © 2017 American College of Cardiology Foundation. Published by

  2. 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.

  3. 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.

  4. Comparison of intravascular ultrasound and quantitative coronary angiography for the assessment of coronary artery disease progression.

    PubMed

    Berry, Colin; L'Allier, Philippe L; Grégoire, Jean; Lespérance, Jacques; Levesque, Sylvie; Ibrahim, Reda; Tardif, Jean-Claude

    2007-04-10

    The relative merits of quantitative coronary analysis (QCA) and intravascular ultrasound (IVUS) for the assessment of progression/regression in coronary artery disease are uncertain. To explore this subject further, we analyzed the angiographic and IVUS data derived from a contemporary clinical trial population. We investigated the relationships between QCA and IVUS at single time points (n=525) and also for the changes over time (n=432). QCA and IVUS data underwent central laboratory analyses. Statistically significant correlations were observed between the QCA coronary artery score and the IVUS-derived lumen volume (r=0.65, P<0.0001) and total vessel volume (r=0.55, P<0.0001) and between the QCA cumulative coronary stenosis score and percent atheroma volume on IVUS (r=0.32, P<0.0001) at baseline for matched segments. A similar pattern of correlations was observed for global (all segments) QCA-derived and single-vessel IVUS-derived data. There were statistically significant but weak correlations between the changes over time in lumen dimensions on QCA and IVUS (P=0.005) and between the change in cumulative coronary stenosis score on QCA and percent atheroma volume on IVUS (r=0.14, P=0.01). Nevertheless, patients with and without angiographic progression had changes in plaque volume on IVUS of 9.13 and 0.20 mm3, respectively (P=0.028). QCA- and IVUS-derived measures of lumen dimensions are correlated at single time points and for changes over time. Although the change in percent atheroma volume is only weakly correlated with QCA changes as continuous variables, disease progression on QCA is associated with significant increases in plaque volume on IVUS compared with no angiographic progression.

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

    PubMed Central

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

    2011-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Yan, Jiayong; Liu, Hong; Cui, Yaoyao

    2014-04-01

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

  7. Retroperitoneal Bleeding and Arteriovenous Fistula after Percutaneous Coronary Intervention Successfully Treated with Intravascular Ultrasound-guided Covered Stent Implantation.

    PubMed

    Mogi, Satoshi; Maekawa, Yuichiro; Fukuda, Keiichi; Noma, Shigetaka

    2016-01-01

    The major puncture-site complications of the transfemoral approach are retroperitoneal bleeding (RPB), arteriovenous (AV) fistula, and arterial pseudoaneurysm. Although the management of RPB and AV fistula depends on individual cases, our experience shows that the use of a covered stent with intravascular ultrasound (IVUS) guidance can successfully manage percutaneous coronary intervention-associated RPB and AV fistula. IVUS guidance can therefore make it easy to use an optimal-size covered stent.

  8. Multispectral fluorescence lifetime imaging system for intravascular diagnostics with ultrasound guidance: in vivo validation in swine arteries.

    PubMed

    Bec, Julien; Ma, Dinglong M; Yankelevich, Diego R; Liu, Jing; Ferrier, William T; Southard, Jeffrey; Marcu, Laura

    2014-05-01

    Fluorescence lifetime technique has demonstrated potential for analysis of atherosclerotic lesions and for complementing existing intravascular imaging modalities such as intravascular ultrasound (IVUS) in identifying lesions at high risk of rupture. This study presents a multimodal catheter system integrating a 40 MHz commercial IVUS and fluorescence lifetime imaging (FLIm) using fast helical motion scanning (400 rpm, 0.75 mm/s), able to acquire in vivo in pulsatile blood flow the autofluorescence emission of arterial vessels with high precision (5.08 ± 0.26 ns mean average lifetime over 13 scans). Co-registered FLIm and IVUS data allowed 3D visualization of both biochemical and morphological vessel properties. Current study supports the development of clinically compatible intravascular diagnostic system integrating FLIm and demonstrates, to our knowledge, the first in vivo intravascular application of a fluorescence lifetime imaging technique.

  9. Intravascular Ultrasound and Histology in In Vitro Assessment of Iliac Artery Angioplasty

    SciTech Connect

    Lankeren, Winnifred van; Gussenhoven, Elma J.; Qureshi, Akeel; Lugt, Aad van der

    1999-01-15

    Purpose: Intravascular ultrasound (IVUS) was used to assess in vitro the morphologic and quantitative effects of balloon angioplasty (PTA) of the iliac artery. Methods: Forty human iliac arteries ({>=} 30% area stenosis) were studied with IVUS in vitro before and after PTA and the findings were validated with histology. Results: The sensitivity of IVUS for dissection was 74% and for media rupture 59%. The incidence of vascular damage was higher when the whole segment was analyzed rather than the target site alone. Dissections occurred at the thinnest region of the plaque, unrelated to plaque calcification. Following PTA, quantitative changes at the target site were greater compared with the overall data derived from all cross-sections. The increase in lumen area was caused solely by an increase in vessel area. Conclusions: IVUS is sensitive in detecting dissections, which occurred irrespective of calcification at the thinnest region of the plaque. The increase in lumen area after PTA was caused by stretching of the vessel.

  10. 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. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  11. 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

  12. Volumetric three-dimensional intravascular ultrasound visualization using shape-based nonlinear interpolation

    PubMed Central

    2013-01-01

    Background Intravascular ultrasound (IVUS) is a standard imaging modality for identification of plaque formation in the coronary and peripheral arteries. Volumetric three-dimensional (3D) IVUS visualization provides a powerful tool to overcome the limited comprehensive information of 2D IVUS in terms of complex spatial distribution of arterial morphology and acoustic backscatter information. Conventional 3D IVUS techniques provide sub-optimal visualization of arterial morphology or lack acoustic information concerning arterial structure due in part to low quality of image data and the use of pixel-based IVUS image reconstruction algorithms. In the present study, we describe a novel volumetric 3D IVUS reconstruction algorithm to utilize IVUS signal data and a shape-based nonlinear interpolation. Methods We developed an algorithm to convert a series of IVUS signal data into a fully volumetric 3D visualization. Intermediary slices between original 2D IVUS slices were generated utilizing the natural cubic spline interpolation to consider the nonlinearity of both vascular structure geometry and acoustic backscatter in the arterial wall. We evaluated differences in image quality between the conventional pixel-based interpolation and the shape-based nonlinear interpolation methods using both virtual vascular phantom data and in vivo IVUS data of a porcine femoral artery. Volumetric 3D IVUS images of the arterial segment reconstructed using the two interpolation methods were compared. Results In vitro validation and in vivo comparative studies with the conventional pixel-based interpolation method demonstrated more robustness of the shape-based nonlinear interpolation algorithm in determining intermediary 2D IVUS slices. Our shape-based nonlinear interpolation demonstrated improved volumetric 3D visualization of the in vivo arterial structure and more realistic acoustic backscatter distribution compared to the conventional pixel-based interpolation method. Conclusions This

  13. 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.

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

    PubMed

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

    2014-01-01

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

  15. Challenges in tissue characterization from backscattered intravascular ultrasound signals

    NASA Astrophysics Data System (ADS)

    Katouzian, Amin; Sathyanarayana, Shashidhar; Li, Wenguang; Thomas, Tom; Carlier, Stéphane G.

    2007-03-01

    Plaque characterization through backscattered intravascular ultrasound (IVUS) signal analysis has been the subject of extensive study for the past several years. A number of algorithms to analyze IVUS images and underlying RF signals to delineate the composition of atherosclerotic plaque have been reported. In this paper, we present several realistic challenges one faces throughout the process of developing such algorithms to characterize tissue type. The basic tenet of ultrasound tissue characterization is that different tissue types imprint their own "signature" on the backscattered echo returning to the transducer. Tissue characterization is possible to the extent that these echo signals can be received, the signatures read, and uniquely attributed to a tissue type. The principal difficulty in doing tissue characterization is that backscattered RF signals originating as echoes from different groups of cells of the same tissue type exhibit no obvious commonality in appearance in the time domain. This happens even in carefully controlled laboratory experiments. We describe the method of acquisition and digitization of ultrasound radiofrequency (RF) signals from left anterior descending and left circumflex coronary arteries. The challenge of obtaining corresponding histology images to match to specific regions-of-interest on the images is discussed. A tissue characterization technique based on seven features is compared to a full spectrum based approach. The same RF and histology data sets were used to evaluate the performances of these two techniques.

  16. Automatic detection of luminal contour in intravascular ultrasound images using fuzzy clustering and snakes

    NASA Astrophysics Data System (ADS)

    Yi, Jianhua; He, Huiguang; Zhao, Mingchang; Liu, Jian; Chen, Xuejiao

    2009-10-01

    Extraction of the luminal contours from the intravascular ultrasound (IVUS) images is very important to analysis and diagnosis of coronary heart disease. Manual processing of large IVUS data is quite tedious and time consuming. This paper presented an algorithm for automatic detection of the luminal contours in intravascular ultrasound images, based on fuzzy clustering and snakes. To solve the difficulty of automatic contour initialization, this paper used fuzzy clustering and spline interpolation to obtain the initial contour. First, fuzzy clustering was used to detect the luminal contours on the multiple longitudinal images. Then, luminal contour points were transformed into the individual transversal images. Those luminal contour points were spline-interpolated on these transversal images. The spline-interpolated contour was used as the initial contour of snakes. We evaluated automatically detection method based on the average contours obtained from expert manual segmentation as the ground truth, and the results had demonstrated that our method was accurate and efficient.

  17. Intravascular near-infrared fluorescence catheter with ultrasound guidance and blood attenuation correction

    NASA Astrophysics Data System (ADS)

    Dixon, Adam J.; Hossack, John A.

    2013-05-01

    Intravascular near-infrared fluorescence (NIRF) imaging offers a new approach for characterizing atherosclerotic plaque, but random catheter positioning within the vessel lumen results in variable light attenuation and can yield inaccurate measurements. We hypothesized that NIRF measurements could be corrected for variable light attenuation through blood by tracking the location of the NIRF catheter with intravascular ultrasound (IVUS). In this study, a combined NIRF-IVUS catheter was designed to acquire coregistered NIRF and IVUS data, an automated image processing algorithm was developed to measure catheter-to-vessel wall distances, and depth-dependent attenuation of the fluorescent signal was corrected by an analytical light propagation model. Performance of the catheter sensing distance correction method was evaluated in coronary artery phantoms and ex vivo arteries. The correction method produced NIRF estimates of fluorophore concentrations, in coronary artery phantoms, with an average root mean square error of 17.5%. In addition, the correction method resulted in a statistically significant improvement in correlation between spatially resolved NIRF measurements and known fluorophore spatial distributions in ex vivo arteries (from r=0.24 to 0.69, p<0.01, n=6). This work demonstrates that catheter-to-vessel wall distances, measured from IVUS images, can be employed to compensate for inaccuracies caused by variable intravascular NIRF sensing distances.

  18. Intravascular near-infrared fluorescence catheter with ultrasound guidance and blood attenuation correction

    PubMed Central

    Hossack, John A.

    2013-01-01

    Abstract. Intravascular near-infrared fluorescence (NIRF) imaging offers a new approach for characterizing atherosclerotic plaque, but random catheter positioning within the vessel lumen results in variable light attenuation and can yield inaccurate measurements. We hypothesized that NIRF measurements could be corrected for variable light attenuation through blood by tracking the location of the NIRF catheter with intravascular ultrasound (IVUS). In this study, a combined NIRF-IVUS catheter was designed to acquire coregistered NIRF and IVUS data, an automated image processing algorithm was developed to measure catheter-to-vessel wall distances, and depth-dependent attenuation of the fluorescent signal was corrected by an analytical light propagation model. Performance of the catheter sensing distance correction method was evaluated in coronary artery phantoms and ex vivo arteries. The correction method produced NIRF estimates of fluorophore concentrations, in coronary artery phantoms, with an average root mean square error of 17.5%. In addition, the correction method resulted in a statistically significant improvement in correlation between spatially resolved NIRF measurements and known fluorophore spatial distributions in ex vivo arteries (from r=0.24 to 0.69, p<0.01, n=6). This work demonstrates that catheter-to-vessel wall distances, measured from IVUS images, can be employed to compensate for inaccuracies caused by variable intravascular NIRF sensing distances. PMID:23698320

  19. 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.

  20. 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.

  1. 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

  2. Radio Frequency Signal Analysis for Tissue Characterization of Coronary Artery: In Vivo Intravascular Ultrasound Study

    NASA Astrophysics Data System (ADS)

    Iwamoto, T.; Saijo, Y.; Tanaka, A.; Filho, E. S.; Li, S.; Yoshizawa, M.

    Intravascular ultrasound (IVUS) is an important clinical tool that provides high resolution cross-sectional image of coronary artery. However, it is difficult to accurately classify plaque composition by conventional IVUS images. In the present study, we apply self-organizing map (SOM) of radiofrequency (RF) signal spectra for automatic plaque classification in IVUS diagnosis. IVUS data were acquired with a commercially available IVUS system with the central frequency of 40 MHz. We used double SOM classifier. The 1st classifier is supervised-SOM, learned four structures (blood, catheter, shadow, and outer lumen) based on spectral parameters. The 2nd classifier is unsupervised-SOM, used for classifying remained data, which were not classified the 1st classifier. We defined categories on the 2nd SOM by using K-means clustering method. Finally, color codes were assigned to the plaque component values, and the tissue color coded maps were reconstructed. Results suggest that the proposed technique is useful for automatic characterization of plaque components in IVUS image.

  3. 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.

  4. 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.

  5. Accurate visualization and quantification of coronary vasculature by 3D/4D fusion from biplane angiography and intravascular ultrasound

    NASA Astrophysics Data System (ADS)

    Wahle, Andreas; Mitchell, Steven C.; Olszewski, Mark E.; Long, Ryan M.; Sonka, Milan

    2001-01-01

    In the rapidly evolving field of intravascular ultrasound (IVUS) for tissue characterization and visualization, the assessment of vessel morphology still lacks a geometrically correct 3D reconstruction. The IVUS frames are usually stacked up to form a straight vessel, neglecting curvature and the axial twisting of the catheter during the pullback. This paper presents a comprehensive system for geometrically correct reconstruction of IVUS images by fusion with biplane angiography, thus combining the advantages of both modalities. Vessel cross-section and tissue characteristics are obtained form IVUS, while the 3D locations are derived by geometrical reconstruction from the angiographic projections. ECG-based timing ensures a proper match of the image data with the respective heart phase. The fusion is performed for each heart phase individually, thus yielding the 4-D data as a set of 3-D reconstructions.

  6. Strain imaging with intravascular ultrasound: An in vivo study

    NASA Astrophysics Data System (ADS)

    Perrey, Christian; Ermert, Helmut; Bojara, Waldemar; Holt, Stephan; Lindstaedt, Michael

    2004-05-01

    The evaluation of mechanical properties of coronary plaques is of high interest for the assessment of coronary diseases. Intravascular ultrasound (IVUS) can be used to visualize strain in coronary tissue. In this study, strain imaging is performed using an IVUS system with a 40-MHz rotating single-element transducer. Radio frequency (rf) data are acquired during in vivo examinations and sampled at 100 MHz. Image frames are stored consecutively during 3 s at a frame rate of 30/s. Data are recorded at different levels of tissue compression. The required pressure difference is caused by natural pulsatile blood flow. The strain imaging algorithm estimates radial strain from rf data based on frame-to-frame correlation. Rotating transducers often show nonuniform rotational distortion (NURD), which leads to misaligned echo lines in consecutive frames. This results in lateral motion artifacts and causes decorrelation. This effect is reduced by lateral motion correction based on block-matching algorithms. Results show that strain imaging can successfully be performed in vivo with data acquired predominantly in diastole. Different coronary tissue regions can be identified by local strain variations. If NURD is present, strain image quality is degraded. In some cases NURD is reduced by repositioning the transducer.

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

    PubMed

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

    1996-05-01

    The purpose of this investigation was to compare the accuracy of intravascular ultrasound (IVUS) and electron-beam computed tomography (EBCT) in quantitating human atherosclerotic plaque and calcium. In experiment 1, 12 human atherosclerotic arterial segments were obtained at autopsy and imaged by using IVUS and EBCT. The plaque from each arterial segment was dissected and a volume measurement of the dissected plaque was obtained by water displacement. The plaque from each arterial segment was ashed at 700 degrees F, and the weight of the remaining ashes was used as an estimate of the calcium mass. In experiment II, 11 calcified arterial segments were obtained at autopsy and imaged by using IVUS at one site along the artery. A corresponding histologic cross section stained with Masson's trichrome was prepared. In experiment I, the mean plaque volume measured by water displacement was 165.3 +/- 118.4 microliters. The mean plaque volume calculated by IVUS was 166.1 +/- 114.4 microliters and correlated closely with that by water displacement (r = 0.98, p < 0.0001). The mean calcium mass measured by ashing was 19.4 +/- 15.8 mg. The mean calculated calcium mass by EBCT was 19.9 mg and correlated closely with that by ashing (r=0.98, p<0.001). The mean calculated calcium volume by IVUS was 18.6 +/- 11.2 microliters and correlated linearly with the calcium mass by ashing (r = 0.87, p < 0.0003). In experiment II, the mean cross-sectional area of the calcified matrix was 1.71 +/- 0.66 mm2 by histologic examination compared with 1.44 +/- 0.66 mm2 by IVUS. There was a good correlation between the calcified cross-sectional area by histologic examination and IVUS (r = 0.76, p < 0.007); however, IVUS may underestimate the amount of calcium present depending on the intralesional calcium morphologic characteristics. In conclusion, IVUS accurately quantitates atherosclerotic plaque volume as well as the cross-sectional area and volume of intralesional calcium, especially if the

  8. Utility of intravascular ultrasound in intracranial and extracranial neurointerventions: experience at University at Buffalo Neurosurgery-Millard Fillmore Gates Circle Hospital.

    PubMed

    Kan, Peter; Mokin, Maxim; Abla, Adib A; Eller, Jorge L; Dumont, Travis M; Levy, Elad I; Siddiqui, Adnan H

    2012-01-01

    Intravascular ultrasound (IVUS) generates high-resolution cross-sectional images and sagittal reconstructions of the vessel wall and lumen. As a result, this imaging modality can provide accurate measurements of the degree of vessel stenosis, allow the detection of intraluminal thrombus, and analyze the plaque composition. The IVUS modality is widely used in interventional cardiology, and its use in neurointerventions has gradually increased. With case examples, the authors illustrate the utility of IVUS as an adjunct to conventional angiography for a wide range of intracranial and extracranial neurointerventions.

  9. Intravascular ultrasound versus digital subtraction angiography: direct comparison of intraluminal diameter measurements in pediatric and adolescent imaging.

    PubMed

    Gill, Anne E; Ciszak, Tadi; Braun, Hayley; Hawkins, C Matthew

    2017-04-01

    Intravascular ultrasound (IVUS) allows intraluminal imaging of blood vessels rather than the one-dimensional luminal outline depicted by digital subtraction angiography (DSA). Despite extensive literature in multiple adult vascular diseases, IVUS has not been directly compared to DSA in pediatric and adolescent vascular pathologies. The purpose of this manuscript is to compare absolute luminal diameter measurements obtained via IVUS and DSA during a variety of pediatric endovascular procedures. We conducted a retrospective review of all pediatric and adolescent endovascular procedures from October 2014 to March 2016 in which IVUS and DSA were used. We compared the vessel diameter measurements and analyzed them using SAS software with a paired t-test. There were 102 total measurements (DSA = 56; IVUS = 56; 22 procedures; 20 patients). On average, IVUS measured 0.6 ± 2.1 mm larger than DSA (95% confidence interval [CI] -0.01 to 1.12; P = 0.06; r = 0.90). When venous compression syndrome (May-Thurner, Nutcracker, superior vena cava syndrome) measurements were excluded, IVUS measured 0.7 ± 1.6 mm larger than DSA (95% CI 0.14 to 1.18; P = 0.01; r = 0.93). When venous compression syndrome measurements were evaluated separately, IVUS measured 0.3 ± 3.0 mm larger than DSA (95% CI -1.16 to 1.82; P = 0.65; r = 0.45). Overall, IVUS measurements were slightly larger than DSA measurements in all data subsets. Absolute vessel diameter measurements obtained with IVUS in the pediatric and adolescent population are statistically significantly larger than those obtained using DSA when excluding venous compression syndromes. In venous compression syndromes, IVUS might provide a more accurate representation of vessel compression and diameter than DSA.

  10. In vivo volumetric analysis of coronary stent using optical coherence tomography with a novel balloon occlusion-flushing catheter: a comparison with intravascular ultrasound.

    PubMed

    Kawase, Yoshiaki; Hoshino, Kozo; Yoneyama, Ryuichi; McGregor, Jennifer; Hajjar, Roger J; Jang, Ik-Kyung; Hayase, Motoya

    2005-10-01

    Optical coherence tomography (OCT) is limited as an intravascular imaging tool because of interference with blood. This study tested a new balloon occlusion-flushing catheter for OCT scanning of stented coronary arteries and compared stent measurements between OCT and intravascular ultrasound (IVUS). Motorized pullback with OCT and IVUS was examined in coronary stents deployed in swine. Quantitative measurements were obtained and compared between both groups. In addition, stent strut thickness was compared among OCT, IVUS and actual measurement. The occlusion catheter successfully provided motorized pullback OCT images in the stented coronary arteries without any complications. There were no differences in calculated lumen volume. However, stent volumes were significantly smaller with OCT than with IVUS (p < 0.05). OCT significantly underestimated the stent strut thickness compared with the actual measurement. Although OCT underestimates the stent strut thickness, motorized pullback OCT imaging with the occlusion catheter can provide appropriate in-stent images in the porcine coronary arteries.

  11. 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

  12. Histopathologic validation of the intravascular ultrasound diagnosis of calcified coronary artery nodules.

    PubMed

    Lee, Jin-Bae; Mintz, Gary S; Lisauskas, Jennifer B; Biro, Sinan G; Pu, Jun; Sum, Stephen T; Madden, Sean P; Burke, Allen P; Goldstein, James; Stone, Gregg W; Virmani, Renu; Muller, James E; Maehara, Akiko

    2011-12-01

    A calcified nodule is a type of potentially vulnerable plaque accounting for approximately 2% to 7% of coronary events. Because its intravascular ultrasound (IVUS) features have never been validated, the aim of this study was to assess the IVUS characteristics of calcified nodules in comparison to histopathology. IVUS was performed in 856 pathologic slices in 29 coronary arteries (11 left anterior descending, 5 left circumflex, and 13 right coronary arteries) in 18 autopsy hearts. Pathologic sections were analyzed every 2 mm; qualitative and quantitative findings of matched IVUS were analyzed. IVUS detected calcification in 285 frames; 17 (6.0%) were calcified nodules, and 268 (94.0%) were non-nodular calcium by histopathology. Two calcified nodules (11.8%) were solitary, and 15 (88.2%) were adjacent to non-nodular calcium. IVUS characteristics of calcified nodules were (1) a convex shape of the luminal surface (94.1% in calcified nodules vs 9.7% in non-nodular calcium, p <0.001), (2) a convex shape of the luminal side of calcium (100% vs 16.0%, p <0.001), (3) an irregular luminal surface (64.7% vs 11.6%, p <0.001), and (4) an irregular leading edge of calcium (88.2% vs 19.0%, p <0.001). Luminal area at the calcified nodule site was larger (6.2 ± 2.4 vs 4.3 ± 1.6 mm(2), p <0.001) and plaque burden less (57 ± 6% vs 68 ± 5%, p <0.001) than at the minimum luminal area site. In conclusion, calcified nodules have distinct IVUS features (irregular and convex luminal surface) permitting their prospective identification in vivo. Copyright © 2011 Elsevier Inc. All rights reserved.

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

    PubMed

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

    2015-07-01

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

  14. Optical frequency domain imaging vs. intravascular ultrasound in percutaneous coronary intervention (OPINION trial): Study protocol for a randomized controlled trial.

    PubMed

    Kubo, Takashi; Shinke, Toshiro; Okamura, Takayuki; Hibi, Kiyoshi; Nakazawa, Gaku; Morino, Yoshihiro; Shite, Junya; Fusazaki, Tetsuya; Otake, Hiromasa; Kozuma, Ken; Akasaka, Takashi

    2016-11-01

    Optical coherence tomography is becoming increasingly widespread as an adjunctive intravascular diagnostic technique in percutaneous coronary intervention (PCI), because of its ability to visualize coronary structures at high resolution. Several studies have reported that intravascular ultrasound (IVUS) guidance in PCI might be helpful to reduce subsequent stent thrombosis, restenosis, repeat revascularization, myocardial infarction, and cardiac death. The OPtical frequency domain imaging vs. INtravascular ultrasound in percutaneous coronary InterventiON (OPINION) trial is aimed at evaluating the impact of optical frequency domain imaging (OFDI) guidance in PCI on clinical outcomes compared with IVUS guidance. The OPINION trial is a multicenter, prospective, randomized, controlled, open-label, parallel group, non-inferiority trial in Japan. The eligible patients are randomly assigned to receive either OFDI-guided PCI or IVUS-guided PCI. PCI is performed using the biolimus-eluting stent in accordance with a certain criteria of OFDI and IVUS for optimal stent deployment. All patients will undergo a follow-up angiography at 8 months. The primary endpoint is target vessel failure composed of cardiac death, myocardial infarction attributed to the target vessel, and clinically-driven target vessel revascularization at 12 months. When completed, the OPINION trial will contribute to define the clinical value of the OFDI guidance in PCI. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  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. Role of intravascular ultrasound imaging during endovascular interventions of failing hemodialysis access grafts.

    PubMed

    Ross, John R; Franga, Dion L; Gallichio, Michael; Patel, Ankur J; Ouriel, Kenneth

    2017-05-01

    Arteriovenous (AV) access graft complications represent a serious complication in patients undergoing hemodialysis. Angiography is one method of visualizing them. However, angiography is not always an effective means of detecting lesions that occur in this context. Intravascular ultrasound (IVUS) is an adjunct modality used to identify stenoses responsible for failing access by identifying multiple stenoses, including those that are most severe. The purpose of this study was to define the value of IVUS in patients with failing AV access grafts by comparing digital subtraction angiography (DSA) alone with DSA followed by IVUS. This was a single-center randomized study comparing IVUS with DSA in patients with failing hemodialysis access grafts. It consisted of 100 randomized hemodialysis patients presenting with failing AV access who were being considered for endovascular intervention. Interventions in the control group were guided by DSA alone, whereas interventions in the test group were guided by DSA followed by IVUS. Patients were observed for 6 months after intervention. The primary end point was the time in days to AV access graft failure after the index intervention, expressed as median and interquartile range. Secondary analyses included influence of DSA and IVUS on index procedure decision-making and percentage of patients with AV access graft reinterventions or discontinuation through 3 and 6 months. Median time to first AV graft reintervention or discontinuation was 61 days in the test group and 30 days in the control group (P = .16), with analysis limited to patients who experienced reintervention or discontinuation (n = 59). IVUS resulted in a change in treatment plan in 76% (44/58) of patients, with no treatment change after IVUS in 24% (14/58) of patients. At 6 months, approximately 35% of patients in both the control and test groups remained free from reinterventions (P = .88). At 6 months, approximately 75% of patients in the control group

  18. Optical coherence tomography versus intravascular ultrasound in the evaluation of observer variability and reliability in the assessment of stent deployment: the OCTIVUS study.

    PubMed

    Magnus, Patrick C; Jayne, John E; Garcia-Garcia, Hector M; Swart, Michael; van Es, Gerrit-Anne; Tijssen, Jan; Kaplan, Aaron V

    2015-08-01

    To compare the variability in the assessment of coronary stents among interventional cardiologists (readers) using optical coherence tomography (OCT) and intravascular ultrasound (IVUS). IVUS is established and validated in the evaluation of coronary stent. For cardiologists without core lab expertise, the utility of IVUS is limited by image quality. OCT yields higher image resolution; however, the consistency with which these readers interpret OCT images has not been fully evaluated or compared with IVUS. OCT and IVUS image sets (five pairs) obtained after stent placement were reviewed by readers with clinical experience in both modalities. Parameters assessed included stent expansion and symmetry, reference vessel and in-stent cross-sectional area (CSA) and diameter, and stent strut apposition as well as Multicenter Ultrasound Stenting in Coronaries criteria. These interpretations were compared with core lab readings and examined for interobserver variability. The interobserver variability for measurement of in-stent CSA was 1.34 mm(2) using IVUS compared with 0.85 mm(2) using OCT (P = 0.024). Variation in the deviation from core lab measurement of in-stent CSA for IVUS was 1.48 mm(2) compared with 0.87 mm(2) for OCT (P = 0.042). The interobserver agreement for obtaining the Multicenter Ultrasound Stenting in Coronaries criteria using IVUS was 80.4% compared with 81.1% using OCT (P = 0.78). Compared with the corelab measurement, the readers obtained an agreement of 72.7% using IVUS vs. 67.3% using OCT (P = 0.43). In the assessment of deployed coronary stents by practicing cardiologists, OCT images are interpreted more consistently compared with IVUS and can be used to assess stent deployment using IVUS-validated metrics. © 2015 Wiley Periodicals, Inc.

  19. 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

  20. (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

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

    PubMed

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

    2015-04-27

    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.

  2. (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.

  3. Multimodality imaging of attenuated plaque using grayscale and virtual histology intravascular ultrasound and optical coherent tomography.

    PubMed

    Kang, Soo-Jin; Ahn, Jung-Min; Han, Seungbong; Park, Duk-Woo; Lee, Seung-Whan; Kim, Young-Hak; Lee, Cheol Whan; Park, Seong-Wook; Mintz, Gary S; Park, Seung-Jung

    2016-07-01

    Although attenuated plaque is a marker for plaque vulnerability, the quantification and its implication have not been known. Multimodality pre-procedural imaging using grayscale intravascular ultrasound (IVUS), virtual histology-IVUS (VH-IVUS), and optical coherence tomography (OCT) were performed in 115 coronary lesions with diameter stenosis (DS) >30% and plaque burden ≥50% and compared the diagnostic accuracies for detecting thin-cap fibroatheromas (TCFA). A maximal arc of attenuation (40 MHz IVUS) ≥29.0° was the cutoff for predicting VH-TCFA (sensitivity 74%, specificity 66%); and OCT-TCFA (sensitivity 89%, specificity 64%), while a maximal arc attenuation ≥29.0° (20MHz IVUS) showed a poor sensitivity for predicting TCFA. Compared to the lesions with an arc of attenuation <30° as a rough cutoff value, the lesions with a maximum arc of attenuation ≥30° (40 MHz) were associated with more severe (smaller angiographic minimum lumen diameter and greater DS, smaller IVUS-MLA and a larger plaque burden) and had more unstable lesion characteristics: (1) larger remodeling index and more plaque ruptures (grayscale IVUS); (2) greater %necrotic core and more VH-TCFAs (VH-IVUS); and (3) more lipid, macrophages, cholesterol crystals, and microchannels; thinner fibrous caps; and more OCT-TCFAs, OCT-detected plaque ruptures, and red and white thrombi (OCT). Among 58 patients treated with stent implantation, postintervention peak CK-MB was higher in patients with the maximal attenuation ≥30° compared to those without (median 2.7 ng/ml [IQR 0.9-18.7 ng/ml] vs. median 0.9 ng/ml [IQR 0.7-2.1 ng/ml], P = 0.012). Attenuated plaque with a maximal attenuation ≥30° vs. <30° (40 MHz, but not 20 MHz IVUS) were more likely to be associated with unstable lesion morphology that may contribute to the immediate poststenting CK-MB elevation. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. 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.

  5. Analysis of Cardiovascular Tissue Components for the Diagnosis of Coronary Vulnerable Plaque from Intravascular Ultrasound Images

    PubMed Central

    Hwang, Yoo Na; Kim, Ga Young; Shin, Eun Seok

    2017-01-01

    The purpose of this study was to characterize cardiovascular tissue components and analyze the different tissue properties for predicting coronary vulnerable plaque from intravascular ultrasound (IVUS) images. For this purpose, sequential IVUS image frames were obtained from human coronary arteries using 20 MHz catheters. The plaque regions between the intima and media-adventitial borders were manually segmented in all IVUS images. Tissue components of the plaque regions were classified into having fibrous tissue (FT), fibrofatty tissue (FFT), necrotic core (NC), or dense calcium (DC). The media area and lumen diameter were also estimated simultaneously. In addition, the external elastic membrane (EEM) was computed to predict the vulnerable plaque after the tissue characterization. The reliability of manual segmentation was validated in terms of inter- and intraobserver agreements. The quantitative results found that the FT and the media as well as the NC would be good indicators for predicting vulnerable plaques in IVUS images. In addition, the lumen was not suitable for early diagnosis of vulnerable plaque because of the low significance compared to the other vessel parameters. To predict vulnerable plaque rupture, future study should have additional experiments using various tissue components, such as the EEM, FT, NC, and media.

  6. Chirp-Coded Ultraharmonic Imaging with a Modified Clinical Intravascular Ultrasound System.

    PubMed

    Shekhar, Himanshu; Huntzicker, Steven; Awuor, Ivy; Doyley, Marvin M

    2016-11-01

    Imaging plaque microvasculature with contrast-enhanced intravascular ultrasound (IVUS) could help clinicians evaluate atherosclerosis and guide therapeutic interventions. In this study, we evaluated the performance of chirp-coded ultraharmonic imaging using a modified IVUS system (iLab™, Boston Scientific/Scimed) equipped with clinically available peripheral and coronary imaging catheters. Flow phantoms perfused with a phospholipid-encapsulated contrast agent were visualized using ultraharmonic imaging at 12 MHz and 30 MHz transmit frequencies. Flow channels with diameters as small as 0.8 mm and 0.5 mm were visualized using the peripheral and coronary imaging catheters. Radio-frequency signals were acquired at standard IVUS rotation speed, which resulted in a frame rate of 30 frames/s. Contrast-to-tissue ratios up to 17.9 ± 1.11 dB and 10.7 ± 2.85 dB were attained by chirp-coded ultraharmonic imaging at 12 MHz and 30 MHz transmit frequencies, respectively. These results demonstrate the feasibility of performing ultraharmonic imaging at standard frame rates with clinically available IVUS catheters using chirp-coded excitation.

  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. An integrated framework for spatio-temporal registration of intravascular ultrasound pullbacks

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Wahle, Andreas; Chen, Zhi; Downe, Richard; Lopez, John; Kovarnik, Tomas; Sonka, Milan

    2015-03-01

    Spatio-temporal registration of baseline and follow-up intravascular ultrasound (IVUS) pullbacks is of paramount importance in studying the progression/regression of coronary artery disease. Automating these two tasks has the potential to increase productivity when studying large patient populations. Current automated methods are often designed for only one of the two tasks - spatial or temporal. In this paper, we propose an integrated framework which combines the two tasks and employs side-branches to constrain the IVUS pullback registration tasks. For temporal registration, canonical time warping technique optimizes extracted features and weighs cumulative distances. For spatial registration, the search range of cross-correlation based method is constrained by utilizing the angular differences between side-branches. Pilot validation is currently available for ten pairs of IVUS pullback sub-sequences. Results show average spatial and temporal registration errors of 0.49 mm +/- 0.51 mm and 5.56° +/- 3.35°, respectively, a notable improvement over our previous approach (p < 0.001) in temporal registration. Our method has the potential to improve spatial and temporal correspondence in studies of atherosclerotic vascular disease development using IVUS.

  10. Two Novel ACM (active Contour Model) Methods for Intravascular Ultrasound Image Segmentation

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    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.

  11. Intravascular ultrasound predictors of CD163 positive macrophage infiltration.

    PubMed

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

    2014-06-01

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

  12. Mapping Intravascular Ultrasound Controversies in Interventional Cardiology Practice

    PubMed Central

    Maresca, David; Adams, Samantha; Maresca, Bruno; van der Steen, Antonius F. W.

    2014-01-01

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

  13. 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.

  14. The transition to IVUS-guided IVC filter deployment in the nontrauma patient.

    PubMed

    Kassavin, Daniel S; Constantinopoulos, George

    2011-02-01

    While prior reports have demonstrated intravascular ultrasound (IVUS)-guided inferior vena cava filter (IVCF) deployment to be feasible, larger reviews using the latest generation of filters in the nontrauma setting are absent. We review our experience with the deployment of 104 IVCFs using IVUS, whereby we transition from a combined use of IVUS with traditional road mapping techniques (venography and/or renal vein cannulation) to the sole use of the IVUS as the road mapping tool for IVCF insertion. The use of IVUS for IVCF deployment minimizes radiation exposure to patients and staff, minimizes patient contrast exposure, and minimizes dependency on auxiliary staff for fluoroscopy. Intravascular ultrasound IVCF deployments can be performed without increasing morbidity and mortality, case duration, or overall costs when compared to standard deployments. The learning curve for transitioning into the use of the IVUS as the primary road mapping tool for IVCF deployments is approximately 20 cases.

  15. 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.

  16. Frequency-domain optical coherence tomography assessment of unprotected left main coronary artery disease-a comparison with intravascular ultrasound.

    PubMed

    Fujino, Yusuke; Bezerra, Hiram G; Attizzani, Guilherme F; Wang, Wei; Yamamoto, Hirosada; Chamié, Daniel; Kanaya, Tomoaki; Mehanna, Emile; Tahara, Satoko; Nakamura, Sunao; Costa, Marco A

    2013-09-01

    To investigate safety and feasibility of imaging unprotected left main (ULM) using frequency-domain optical coherence tomography (FD-OCT) compared with intravascular ultrasound (IVUS). IVUS has been used to assess and guide percutaneous coronary intervention (PCI) of ULM disease. FD-OCT offers 10-fold higher axial resolution than IVUS and its high-speed image acquisition obviates the need for proximal balloon occlusion. We prospectively enrolled 35 consecutive patients with ULM disease. FD-OCT and IVUS assessments were attempted pre- and post-PCI and compared in regards to safety, ability to image the region of interest (ROI), number of pullbacks, volume of contrast and ability to detect malapposition, dissection, and thrombus. Patients were followed for 1 year when FD-OCT imaging was repeated. FD-OCT required more repeated pullbacks to image the ROI compared to IVUS. Mean lumen and stent areas were similar between FD-OCT and IVUS (11.24 ± 2.66 vs. 10.85 ± 2.47 mm(2) , P = 0.13 and 10.44 ± 2.33 vs. 10.49 ± 2.32 mm(2) , P = 0.82, respectively), whereas imaged stent length was shorter with FD-OCT. Malapposition areas and volumes were larger and more edge dissections were detected by FD-OCT. There were no clinical adverse events and no complications associated with FD-OCT at baseline and 1-year follow-up. All dissections were healed, whereas stent malapposition was still detected at follow-up. FD-OCT assessment of ULM is feasible and safe. Direct comparisons with IVUS reveal that FD-OCT achieved imaging completeness less often, whereas it was more sensitive in detecting malapposition and edge dissections, and similar to IVUS in the assessment of lumen and stent dimensions. Copyright © 2013 Wiley Periodicals, Inc.

  17. Simultaneous Registration of Location and Orientation in Intravascular Ultrasound Pullbacks Pairs Via 3D Graph-Based Optimization.

    PubMed

    Zhang, Ling; Wahle, Andreas; Chen, Zhi; Zhang, Li; Downe, Richard W; Kovarnik, Tomas; Sonka, Milan

    2015-12-01

    A novel method is reported for simultaneous registration of location (axial direction) and orientation (circumferential direction) of two intravascular ultrasound (IVUS) pullbacks of the same vessel taken at different times. Monitoring plaque progression or regression (e.g., during lipid treatment) is of high clinical relevance. Our method uses a 3D graph optimization approach, in which the cost function jointly reflects similarity of plaque morphology and plaque/perivascular image appearance. Graph arcs incorporate prior information about temporal correspondence of the two IVUS sequences and limited angular twisting between consecutive IVUS images. Additionally, our approach automatically identifies starting and ending frame pairs in the two IVUS pullbacks. Validation of our method was performed in 29 pairs of IVUS baseline/follow-up pullback sequences consisting of 8 622 IVUS image frames in total. In comparison to manual registration by three experts, the average location and orientation registration errors ranged from 0.72 mm to 0.79 mm and from 7.3(°) to 9.3(°), respectively, all close to the inter-observer variability with no difference being statistically significant (p = NS). Rotation angles determined by our automated approach and expert observers showed high correlation (r(2) of 0.97 to 0.98) and agreed closely (mutual bias between the automated method and expert observers ranged from -1.57(°) to 0.15(°)). Compared with state-of-the-art approaches, the new method offers lower errors in both location and orientation registration. Our method offers highly automated and accurate IVUS pullback registration and can be employed in IVUS-based studies of coronary disease progression, enabling more focal studies of coronary plaque development and transition of vulnerability.

  18. Simultaneous Registration of Location and Orientation in Intravascular Ultrasound Pullbacks Pairs via 3D Graph-Based Optimization

    PubMed Central

    Wahle, Andreas; Chen, Zhi; Zhang, Li; Downe, Richard W.; Kovarnik, Tomas; Sonka, Milan

    2015-01-01

    A novel method is reported for simultaneous registration of location (axial direction) and orientation (circumferential direction) of two intravascular ultrasound (IVUS) pullbacks of the same vessel taken at different times. Monitoring plaque progression or regression (e.g., during lipid treatment) is of high clinical relevance. Our method uses a 3D graph optimization approach, in which the cost function jointly reflects similarity of plaque morphology and plaque/perivascular image appearance. Graph arcs incorporate prior information about temporal correspondence of the two IVUS sequences and limited angular twisting between consecutive IVUS images. Additionally, our approach automatically identifies starting and ending frame pairs in the two IVUS pullbacks. Validation of our method was performed in 29 pairs of IVUS baseline/follow-up pullback sequences consisting of 8,622 IVUS image frames in total. In comparison to manual registration by three experts, the average location and orientation registration errors ranged from 0.72 mm to 0.79 mm and from 7.3° to 9.3°, respectively, all close to the inter-observer variability with no difference being statistically significant (p = NS). Rotation angles determined by our automated approach and expert observers showed high correlation (r2 of 0.97 to 0.98) and agreed closely (mutual bias between the automated method and expert observers ranged from −1.57° to 0.15°). Compared with state-of-the-art approaches, the new method offers lower errors in both location and orientation registration. Our method offers highly automated and accurate IVUS pullback registration and can be employed in IVUS-based studies of coronary disease progression, enabling more focal studies of coronary plaque development and transition of vulnerability. PMID:26080381

  19. Safety of embolic protection device-assisted and unprotected intravascular ultrasound in evaluating carotid artery atherosclerotic lesions

    PubMed Central

    Musialek, Piotr; Pieniazek, Piotr; Tracz, Wieslawa; Tekieli, Lukasz; Przewlocki, Tadeusz; Kablak-Ziembicka, Anna; Motyl, Rafal; Moczulski, Zbigniew; Stepniewski, Jakub; Trystula, Mariusz; Zajdel, Wojciech; Roslawiecka, Agnieszka; Zmudka, Krzysztof; Podolec, Piotr

    2012-01-01

    Summary Background Significant atherosclerotic stenosis of internal carotid artery (ICA) origin is common (5–10% at ≥60 years). Intravascular ultrasound (IVUS) enables high-resolution (120 μm) plaque imaging, and IVUS-elucidated features of the coronary plaque were recently shown to be associated with its symptomatic rupture/thrombosis risk. Safety of the significant carotid plaque IVUS imaging in a large unselected population is unknown. Material/Methods We prospectively evaluated the safety of embolic protection device (EPD)-assisted vs. unprotected ICA-IVUS in a series of consecutive subjects with ≥50% ICA stenosis referred for carotid artery stenting (CAS), including 104 asymptomatic (aS) and 187 symptomatic (S) subjects (age 47–83 y, 187 men). EPD use was optional for IVUS, but mandatory for CAS. Results Evaluation was performed of 107 ICAs (36.8%) without EPD and 184 with EPD. Lesions imaged under EPD were overall more severe (peak-systolic velocity 2.97±0.08 vs. 2.20±0.08m/s, end-diastolic velocity 1.0±0.04 vs. 0.7±0.03 m/s, stenosis severity of 85.7±0.5% vs. 77.7±0.6% by catheter angiography; mean ±SEM; p<0.01 for all comparisons) and more frequently S (50.0% vs. 34.6%, p=0.01). No ICA perforation or dissection, and no major stroke or death occurred. There was no IVUS-triggered cerebral embolization. In the procedures of (i) unprotected IVUS and no CAS, (ii) unprotected IVUS followed by CAS (filters – 39, flow reversal/blockade – 3), (iii) EPD-protected (filters – 135, flow reversal/blockade – 48) IVUS+CAS, TIA occurred in 1.5% vs. 4.8% vs. 2.7%, respectively, and minor stroke in 0% vs. 2.4% vs. 2.1%, respectively. EPD intolerance (on-filter ICA spasm or flow reversal/blockade intolerance) occurred in 9/225 (4.0%). IVUS increased the procedure duration by 7.27±0.19 min. Conclusions Carotid IVUS is safe and, for the less severe lesions in particular, it may not require mandatory EPD use. High-risk lesions can be safely evaluated with

  20. 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

  1. An IVUS transducer for microbubble therapies.

    PubMed

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

    2014-03-01

    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.

  2. 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

  3. 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.

  4. Reproducibility of volumetric intravascular ultrasound radiofrequency-based analysis of coronary plaque composition in vivo.

    PubMed

    Hartmann, Marc; Mattern, Eline S K; Huisman, Jennifer; van Houwelingen, Gert K; de Man, Frits H A F; Stoel, Martin G; Danse, Peter W; Louwerenburg, Hans W; von Birgelen, Clemens

    2009-01-01

    Intravascular ultrasound radiofrequency (RF-IVUS) data permit the analysis of coronary plaque composition in vivo and is used as an endpoint of ongoing pharmacological intervention trials. We assessed the reproducibility of volumetric RF-IVUS analyses in mild-to-moderately diseased atherosclerotic human coronary arteries in vivo. A total of 9,212 IVUS analyses on cross-sectional IVUS frames was performed to evaluate the reproducibility of volumetric RF-IVUS measurements in 33 coronary segments with a length of 27 +/- 7 mm. For vessel, lumen, and plaque + media volume the relative measurement differences (P = NS for all) were (A = intraobserver comparison, same pullback) -0.40 +/- 1.0%; -0.48 +/- 1.4%; -0.35 +/- 1.6%, (B = intraobserver comparison, repeated pullback) -0.42 +/- 1.2%; -0.52 +/- 1.8%; -0.43 +/- 4.5% (C = interobserver comparison, same pullback) 0.71 +/- 1.8%; 0.71 +/- 2.2%, and 0.89 +/- 5.0%, respectively. For fibrous, fibro-lipidic, calcium, and necrotic-core volumes the relative measurement differences (P = NS for all) were (A) 0.45 +/- 2.1%; -1.12 +/- 4.9%; -0.84 +/- 2.1%; -0.22 +/- 1.8%, (B) 1.40 +/- 4.1%; 1.26 +/- 6.7%; 2.66 +/- 7.4%; 0.85 +/- 4.4%, and (C) -1.60 +/- 4.9%; 3.85 +/- 8.2%; 1.66 +/- 7.5%, and -1.58 +/- 4.7%, respectively. Of note, necrotic-core volume showed on average the lowest measurement variability. Thus, in mild-to-moderate atherosclerotic coronary artery disease the reproducibility of volumetric compositional RF-IVUS measurements from the same pullback is relatively high, but lower than the reproducibility of geometrical IVUS measurements. Measurements from repeated pullbacks and by different observers show acceptable reproducibilities; the volumetric measurement of the necrotic-core shows on average the highest reproducibility of the compositional RF-IVUS measurements.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  6. Multidimensional segmentation of coronary intravascular ultrasound images using knowledge-based methods

    NASA Astrophysics Data System (ADS)

    Olszewski, Mark E.; Wahle, Andreas; Vigmostad, Sarah C.; Sonka, Milan

    2005-04-01

    In vivo studies of the relationships that exist among vascular geometry, plaque morphology, and hemodynamics have recently been made possible through the development of a system that accurately reconstructs coronary arteries imaged by x-ray angiography and intravascular ultrasound (IVUS) in three dimensions. Currently, the bottleneck of the system is the segmentation of the IVUS images. It is well known that IVUS images contain numerous artifacts from various sources. Previous attempts to create automated IVUS segmentation systems have suffered from either a cost function that does not include enough information, or from a non-optimal segmentation algorithm. The approach presented in this paper seeks to strengthen both of those weaknesses -- first by building a robust, knowledge-based cost function, and then by using a fully optimal, three-dimensional segmentation algorithm. The cost function contains three categories of information: a compendium of learned border patterns, information theoretic and statistical properties related to the imaging physics, and local image features. By combining these criteria in an optimal way, weaknesses associated with cost functions that only try to optimize a single criterion are minimized. This cost function is then used as the input to a fully optimal, three-dimensional, graph search-based segmentation algorithm. The resulting system has been validated against a set of manually traced IVUS image sets. Results did not show any bias, with a mean unsigned luminal border positioning error of 0.180 +/- 0.027 mm and an adventitial border positioning error of 0.200 +/- 0.069 mm.

  7. Plaque Vulnerability as Assessed by Radiofrequency Intravascular Ultrasound in Patients with Valvular Calcification

    PubMed Central

    Senguttuvan, Nagendra Boopathy; Kumar, Sharath; Mishra, Sundeep; Cho, Jun Hwan; Kwon, Jee Eun; Hyeon, Seong Hyeop; Jeong, Yun Sang; Won, Hoyoun; Shin, Seung Yong; Lee, Kwang Je; Kim, Tae Ho; Kim, Chee Jeong; Kim, Sang-Wook

    2016-01-01

    Background Cardiac valvular calcification is associated with the overall coronary plaque burden and considered an independent cardiovascular risk and prognostic factor. The purpose of this study was to evaluate the relationship between the presence of valvular calcification and plaque morphology and/or vulnerability. Methods Transthoracic echocardiography was used to assess valvular calcification in 280 patients with coronary artery disease who underwent radiofrequency intravascular ultrasound (Virtual Histology IVUS, VH-IVUS). A propensity score–matched cohort of 192 patients (n = 96 in each group) was analyzed. Thin-capped fibroatheroma (TCFA) was defined as a necrotic core (NC) >10% of the plaque area with a plaque burden >40% and NC in contact with the lumen for ≥3 image slices. A remodeling index (lesion/reference vessel area) >1.05 was considered to be positive. Results Patients were divided into two groups: any calcification in at least one valve (152 patients) vs. no detectable valvular calcification (128 patients). Groups were similar in terms of age, risk factors, clinical diagnosis, and angiographic analysis after propensity score-matched analysis. Gray-scale IVUS analysis showed that the vessel size, plaque burden, minimal lumen area, and remodeling index were similar. By VH-IVUS, % NC and % dense calcium (DC) were greater in patients with valvular calcification (p = 0.024, and p = 0.016, respectively). However, only % DC was higher at the maximal NC site by propensity score-matched analysis (p = 0.029). The frequency of VH-TCFA occurrence was higher depending on the complexity (p = 0.0064) and severity (p = 0.013) of valvular calcification. Conclusions There is a significant relationship between valvular calcifications and VH-IVUS assessment of TCFAs. Valvular calcification indicates a greater atherosclerosis disease complexity (increased calcification of the coronary plaque) and vulnerable coronary plaques (higher incidence of VH-TCFA). PMID

  8. Reliable and Accurate Calcium Volume Measurement in Coronary Artery Using Intravascular Ultrasound Videos.

    PubMed

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

    2016-03-01

    Quantitative assessment of calcified atherosclerotic volume within the coronary artery wall is vital for cardiac interventional procedures. The goal of this study is to automatically measure the calcium volume, given the borders of coronary vessel wall for all the frames of the intravascular ultrasound (IVUS) video. Three soft computing fuzzy classification techniques were adapted namely Fuzzy c-Means (FCM), K-means, and Hidden Markov Random Field (HMRF) for automated segmentation of calcium regions and volume computation. These methods were benchmarked against previously developed threshold-based method. IVUS image data sets (around 30,600 IVUS frames) from 15 patients were collected using 40 MHz IVUS catheter (Atlantis® SR Pro, Boston Scientific®, pullback speed of 0.5 mm/s). Calcium mean volume for FCM, K-means, HMRF and threshold-based method were 37.84 ± 17.38 mm(3), 27.79 ± 10.94 mm(3), 46.44 ± 19.13 mm(3) and 35.92 ± 16.44 mm(3) respectively. Cross-correlation, Jaccard Index and Dice Similarity were highest between FCM and threshold-based method: 0.99, 0.92 ± 0.02 and 0.95 + 0.02 respectively. Student's t-test, z-test and Wilcoxon-test are also performed to demonstrate consistency, reliability and accuracy of the results. Given the vessel wall region, the system reliably and automatically measures the calcium volume in IVUS videos. Further, we validated our system against a trained expert using scoring: K-means showed the best performance with an accuracy of 92.80%. Out procedure and protocol is along the line with method previously published clinically.

  9. Dilatation Mechanism of Balloon Angioplasty in Children: Assessment by Angiography and Intravascular Ultrasound

    SciTech Connect

    Ino, Toshihiro; Kishiro, Masahiko; Okubo, Mataichi; Akimoto, Katsumi; Nishimoto, Kei; Yabuta, Keijiro; Kawasaki, Shiori; Hosoda, Yasuyuki

    1998-03-15

    Purpose: Little information is available about the dilatation mechanism in children. This prospective study aimed to (1) evaluate the dilatation mechanism of balloon angioplasty in children with arterial stenosis, and (2) compare the morphological changes seen by intravascular ultrasound (IVUS) and angiography. Methods: Twenty consecutive patients, who had undergone a total of 23 procedures, were examined before and immediately after balloon angioplasty with a 4.3 Fr, 30 MHz rotational tip IVUS system. The lesions for IVUS study had resulted from coarctation of the aorta in six patients, pulmonary arterial stenosis in five, Blalock-Taussig shunt stenosis in three, subclavian artery stenosis in two, renal artery stenosis in two, coronary artery stenosis in one and ductus arteriosus in one. Results: Four distinctive morphological types were identified: type I with arterial stretching, type IIa with superficial tearing, type IIb with deep intimal-medial tearing, type III with flap formation, and type IV with dissection. The diameter of the narrowest site before and after balloon angioplasty increased significantly from 2.1 {+-} 1.4 mm to 4.6 {+-} 3.4 mm (p < 0.001). Eighteen of the 23 angioplasty procedures (78%) were considered to be successful, with a dilatation ratio of more than 50%. In most patients with successful dilatation, non-stretch mechanisms such as tearing, flap formation, or dissection were found. The positive percent (70%) of non-stretch mechanisms seen by IVUS was significantly higher than the positive findings (39%) by angiography ({chi}{sup 2}= 6.47, p < 0.02). Conclusions: Non-stretch morphology of the arterial wall may be a common mechanism of dilatation after balloon angioplasty in children with arterial stenosis. IVUS is a useful modality for evaluating the effectiveness of balloon angioplasty and the mechanism of dilatation in individual cases.

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

    PubMed Central

    de Figueiredo, José Albuquerque; Nogueira, Iara Antonia Lustosa; Figueiro, Mabel Fernandes; Buehler, Anna Maria; Berwanger, Otavio

    2013-01-01

    Background The impact of intravascular ultrasound (IVUS) use on stenting has shown inconclusive results. Objective Systematic review and meta-analysis of the impact of IVUS on stenting regarding the clinical and angiographic evolution. Methods A search was performed in Medline/Pubmed, CENTRAL, Embase, Lilacs, Scopus and Web of Science databases. It included randomized clinical trials (RCTs) that evaluated the implantation of stents guided by IVUS, compared with those using angiography alone (ANGIO). The minimum follow-up duration was six months and the following outcomes were assessed: thrombosis, mortality, myocardial infarction, percutaneous and surgical revascularization, major adverse cardiovascular events (MACE) and restenosis. The binary outcomes were presented considering the number of events in each group; the estimates were generated by a random effects model, considering Mantel-Haenszel statistics as weighting agent and magnitude of effect for the relative risk (RR) with its respective 95% confidence interval (95%CI). Higgins I2 test was used to quantify the consistency between the results of each study. Results A total of 2,689 articles were evaluated, including 8 RCTs. There was a 27% reduction in angiographic restenosis (RR: 0.73, 95% CI: 0.54-0.97, I2 = 51%) and statistically significant reduction in the rates of percutaneous revascularization and overall (RR: 0.88; 95% CI: 0.51 to 1.53, I2 = 61%, RR: 0.73, 95% CI: 0.54 to 0.99, I2 = 55%), with no statistical difference in surgical revascularization (RR: 0.95, 95% CI: 0.52-1.74, I2 = 0%) in favor of IVUS vs. ANGIO. There were no differences regarding the other outcomes in the comparison between the two strategies. Conclusion Angioplasty with stenting guided by IVUS decreases the rates of restenosis and revascularization, with no impact on MACE, acute myocardial infarction, mortality or thrombosis outcomes. PMID:23821407

  11. Bi-modal imaging of atherosclerotic plaques: Automated method for co-registration between fluorescence lifetime imaging and intravascular ultrasound data

    NASA Astrophysics Data System (ADS)

    Gorpas, Dimitris; Fatakdawala, Hussain; Bec, Julien; Ma, Dinglong; Yankelevich, Diego R.; Bishop, John W.; Qi, Jinyi; Marcu, Laura

    2014-03-01

    The risk of atherosclerosis plaque rupture cannot be assessed by the current imaging systems and thus new multi-modal technologies are under investigation. This includes combining a new fluorescence lifetime imaging (FLIm) technique, which is sensitive to plaque biochemical features, with conventional intravascular ultrasound (IVUS), which provides information on plaque morphology. In this study we present an automated method allowing for the co-registration of imaging data acquired based on these two techniques. Intraluminal studies were conducted in ex-vivo segments of human coronaries with a multimodal catheter integrating a commercial IVUS (40 MHz) and a rotational side-viewing fiber based multispectral FLIm system (355 nm excitation, 390+/-20, 452+/-22 and 542+/-25 nm acquisition wavelengths). The proposed method relies on the lumen/intima boundary extraction from the IVUS polar images. Image restoration is applied for the noise reduction and edge enhancement, while gray-scale peak tracing over the A-lines of the IVUS polar images is applied for the lumen boundary extraction. The detection of the guide-wire artifact is used for the angular registration between FLIm and IVUS data, after which the lifetime values can be mapped onto the segmented lumen/intima interface. The segmentation accuracy has been assessed against manual tracings, providing 0.120+/-0.054 mm mean Hausdorff distance. This method makes the bi-modal FLIm and IVUS approach feasible for comprehensive intravascular diagnostic by providing co-registered biochemical and morphological information about atherosclerotic plaques.

  12. Quantitative analysis for lumen and media-adventitia border detection in intravascular ultrasound images

    NASA Astrophysics Data System (ADS)

    Wang, Ling; Yu, Daoyin; Chen, Xiaodong; An, Zhiyong

    2008-12-01

    Therosclerosis causes partial or total obstruction of human arteries. Early quantitative analysis and accurate assessment of plaque position and volume are essential for the selection of the appropriate treatment. Several imaging techniques can be used for the estimation of the severity of the disease in vivo. Intravascular ultrasound (IVUS) is a commonly used diagnostic tool, which provides real-time visualization of plaque morphology and detection of typical plaque components, such as calcium, quantification of plaque eccentricity and wall thickness. In this paper, we firstly used a spatio-temporal filter to reduce the effect of speckles and enhance the image. Then we translated the problem of image segmentation to the problem of the minimum resolution of energy function. using an improved deformable models, we detected the border of lumen and media-adventitia in sequential intravascular ultrasound frames, and optimized it by dynamic programming. Finally, through the identification of the internal and external elastic lamina and the plaque-lumen interface, we figured out the parameter of plaque load, maximal and minimal diameters of the internal and external elastic lamina and so on. The obtained results demonstrate that our method is statistically accurate, reproducible, and capable to identify the regions of interest in sequences of IVUS frames.

  13. 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.

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

    PubMed

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

    2016-02-01

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

  15. Comparison between three-dimensional angiographic reconstruction and intravascular ultrasound: imaging of the left main coronary artery.

    PubMed

    Spoon, Daniel B; Rubinshtein, Ronen; Psaltis, Peter J; Sandhu, Gupreet S; Lennon, Ryan; Rihal, Charanjit S; Lerman, Amir

    2013-06-01

    The purpose of this study was to evaluate the left main (LM) coronary artery anatomy using three-dimensional (3D) quantitative coronary angiography (QCA) software as compared to intravascular ultrasound (IVUS). Percutaneous intervention of the LM coronary artery is becoming more common in selected patients with LM coronary artery disease (CAD). Quantification of LM CAD by conventional angiography can be difficult. IVUS is considered the gold standard to evaluate LM anatomy and severity of CAD but entails additional steps, catheters, and expertise. Our objective was to compare a novel quantitative angiographic analysis system with IVUS for LM anatomy. Fifty five patients underwent both coronary angiography and IVUS of the LM. LM measurements were analyzed with 3D QCA (IC-PRO, Paieon, Israel) software using IVUS as the reference standard. The measurements included proximal, middle, distal minimal luminal diameter (MLD) and area. Additionally, lesion MLD, minimal luminal area were recorded by both systems. Bland-Altman plots were used to investigate agreement between the two imaging systems. Of the 55 patients in our cohort, average age was 66 ± 11 years (25% female). By Bland-Altman analysis there was very good agreement between 3D QCA and IVUS for measures of MLD and minimal lumen area (MLA). However, there was poor concordance in the estimation of plaque burden between the two methods. Our data demonstrate that 3D QCA software has fair agreement when compared with IVUS for imaging of LM MLD and MLA. These results suggest that 3D QCA could potentially be helpful to guide intervention of the LM. Copyright © 2012 Wiley Periodicals, Inc.

  16. Evaluation of Directional Atherectomy Studied by Intravascular Ultrasound in Femoropopliteal Artery Stenosis

    SciTech Connect

    Tielbeek, Alexander V.; Vroegindeweij, Dammis; Gussenhoven, Elma J.; Buth, Jacob; Landman, Guido H.M.

    1997-11-15

    Purpose: To evaluate the role of intravascular ultrasound (IVUS) before and after directional atherectomy (DA) in the treatment of femoropopliteal artery stenosis. Methods: In 12 patients with 16 stenoses IVUS was performed before and immediately after an angiographically successful DA. This was defined as a diameter reduction (DR) {<=} 50%, which was calculated using the minimal lumen diameter compared with the diameter of a nearby 'normal' segment. In the presence of residual plaque on IVUS an additional DA was performed. Endpoints studied were DR {<=} 30% on IVUS compared with the IVUS findings of the angiographically normal reference segment, or when no additional atherosclerotic material could be removed by further DA passages. Results: Additional DA (mean 1.6 per lesion) had to be performed in all patients. Initial DA increased the cross-sectional free lumen area (FLA) from 3.8 {+-} 2.0 mm{sup 2} to 8.1 {+-} 2.7 mm{sup 2} (p= 0.0004). Additional DA increased FLA to 9.3 {+-} 2.3 mm{sup 2} (p= 0.002) after the second passage and to 9.8 {+-} 2.4 mm{sup 2} (p= 0.09) after the final DA run. The plaque area (PLA) before DA decreased from 18.1 {+-} 4.2 mm{sup 2} to 15.4 {+-} 4.8 mm{sup 2} (p= 0.002) after the first passage, and to 13.5 {+-} 5.0 mm{sup 2} (p= 0.004) and 12.8 {+-} 4.4 mm{sup 2} (p= 0.07) after the second and final DA runs, respectively. PLA of the reference segment (9.5 {+-} 5.7 mm{sup 2}) was significantly smaller (p= 0.006) than the final PLA of the treated lesion, indicating a large amount of retained plaque. As a result of DA there was an increase in the area bordered by the medial layer, i.e., the total vessel area (from 21.9 {+-} 4.7 mm{sup 2} to 23.0 {+-} 4.7 mm{sup 2}), significantly in eccentric and soft lesions. On IVUS, dissection and plaque rupture after the final passage was seen in 12 of 16 stenoses; two dissections were seen on the completion angiogram. After the final passage in all stenoses except three, the DR with IVUS was {<=} 30

  17. 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.

  18. Modelling of image-catheter motion for 3-D IVUS.

    PubMed

    Rosales, Misael; Radeva, Petia; Rodriguez-Leor, Oriol; Gil, Debora

    2009-02-01

    Three-dimensional intravascular ultrasound (IVUS) allows to visualize and obtain volumetric measurements of coronary lesions through an exploration of the cross sections and longitudinal views of arteries. However, the visualization and subsequent morpho-geometric measurements in IVUS longitudinal cuts are subject to distortion caused by periodic image/vessel motion around the IVUS catheter. Usually, to overcome the image motion artifact ECG-gating and image-gated approaches are proposed, leading to slowing the pullback acquisition or disregarding part of IVUS data. In this paper, we argue that the image motion is due to 3-D vessel geometry as well as cardiac dynamics, and propose a dynamic model based on the tracking of an elliptical vessel approximation to recover the rigid transformation and align IVUS images without loosing any IVUS data. We report an extensive validation with synthetic simulated data and in vivo IVUS sequences of 30 patients achieving an average reduction of the image artifact of 97% in synthetic data and 79% in real-data. Our study shows that IVUS alignment improves longitudinal analysis of the IVUS data and is a necessary step towards accurate reconstruction and volumetric measurements of 3-D IVUS.

  19. 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.

  20. 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.

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

    PubMed

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

    2017-10-01

    Intravascular ultrasound (IVUS) has been routinely used in some centers to investigate cardiac allograft vasculopathy in pediatric heart transplant recipients. We present an alternative method using more sophisticated imaging software. This study presents a comparison of this method with an established standard method. All patients who had IVUS performed in 2014 were retrospectively evaluated. The standard technique consisted of analysis of 10 operator-selected segments along the vessel. Each study was re-evaluated using a longitudinal technique, taken at every third cardiac cycle, along the entire vessel. Semiautomatic edge detection software was used to detect vessel imaging planes. Measurements included outer and inner diameter, total and luminal area, maximal intimal thickness (MIT), and intimal index. Each IVUS was graded for severity using the Stanford classification. All results were given as mean ± standard deviation (SD). Groups were compared using Student t test. A P value <.05 was considered significant. There were 59 IVUS studies performed on 58 patients. There was no statistically significant difference between outer diameter, inner diameter, or total area. In the longitudinal group, there was a significantly smaller luminal area, higher MIT, and higher intimal index. Using the longitudinal technique, there was an increase in Stanford classification in 20 patients. The longitudinal technique appeared more sensitive in assessing the degree of cardiac allograft vasculopathy and may play a role in the increase in the degree of thickening seen. It may offer an alternative way of grading severity of cardiac allograft vasculopathy in pediatric heart transplant recipients. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    PubMed Central

    Sánchez-Elvira, Guillermo; Coma-Canella, Isabel; Artaiz, Miguel; Páramo, José Antonio; Barba, Joaquín; Calabuig, José

    2010-01-01

    According to post-mortem studies, luminal thrombosis occurs from plaque rupture, erosion and calcified nodules. In vivo studies have found thin cap fibroatheroma (TCFA) as the main vulnerable lesion, prone to rupture. Few data about other post-mortem lesions have been reported in vivo. Our main objective is to characterize in vivo the coronary plaques with intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT), in order to detect not only thin cap fibroatheroma (TCFA), but also other possible vulnerable lesions. The secondary objective is to correlate these findings with clinical and analytical data. Twenty-five patients (18 stable) submitted to coronary angiography were included in this pilot study. After angiography, the three vessels were studied (when possible) with IVUS-VH and OCT. Plaque characteristics were correlated with clinical and analytical data. Forty-six lesions were analyzed. IVUS-VH detected significant necrotic core in 15 (3 were definite TCFA). OCT detected TCFA in 10 lesions, erosion in 6, thrombus in 5 and calcified nodule in 8. Possible vulnerable lesion was found in 61% of stable and 57% of unstable patients. Erosions and calcified nodules were only found in stable patients. Those with significant necrotic core had higher body mass index (P=0.016), higher levels of hs-CRP (P=0.019) and triglycerides (P=0.040). The higher the levels of hs-CRP, the larger the size of the necrotic core (r=0.69, P=0.003). Lesions with characteristics of vulnerability were detected by IVUS-VH and OCT in more than 50% of stable and unstable coronary patients. A significant necrotic core was mainly correlated with higher hs-CRP. PMID:21977297

  3. 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].

  4. 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. © The Author(s) 2016.

  5. Invasive characterization of atherosclerotic plaque in patients with peripheral arterial disease using near-infrared spectroscopy intravascular ultrasound.

    PubMed

    Abbas, Amr E; Zacharias, Sibin K; Goldstein, James A; Hanson, Ivan D; Safian, Robert D

    2017-09-01

    We describe the characteristics of atherosclerotic plaque in patients with peripheral arterial disease (PAD) using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) BACKGROUND: Imaging and autopsy studies have described atherosclerotic plaque in different vascular beds, including varying degrees of lipid, fibrosis, and calcification. Recently, NIRS has been validated as an accurate method for detecting lipid-core plaque (LCP) in the coronary circulation. Invasive evaluation of plaque composition using NIRS-IVUS has not been reported in different peripheral arterial circulations. We performed invasive angiography and NIRS-IVUS in consecutive PAD patients prior to percutaneous revascularization. Imaging evaluation included parameters from angiography, IVUS, and NIRS. NIRS-IVUS findings were compared among different vascular beds with regard to the presence and extent of calcification and LCP. One hundred and forty-nine lesions in 126 PAD patients were enrolled, including the internal carotid (n = 10), subclavian/axillary (n = 9), renal (n = 14), iliac (n = 35), femoropopliteal (n = 69), and infrapopliteal (n = 12) arteries. Plaque morphology was calcified in 132 lesions (89%) and fibrous in 17 lesions (11%). Calcification varied from 100% of renal artery stenoses to 55% of subclavian/axillary artery stenoses. LCP was present in 48 lesions (32%) and prevalence varied from 60% in carotid artery stenoses to 0% in renal artery stenoses (P < 0.005). LCP was only observed in fibrocalcific plaque, and was longitudinally and circumferentially surrounded by a more extensive degree of calcium. NIRS-IVUS in stable PAD patients demonstrates a high frequency of calcific plaque and statistically significant differences in the frequency of LCP in different arterial beds. LCP, when present in the peripheral circulation, is always associated with calcified plaque. The strong co-localization of calcified plaque and LCP in severe PAD lesions

  6. Near-Infrared Spectroscopy Enhances Intravascular Ultrasound Assessment of Vulnerable Coronary Plaque: A Combined Pathological and In Vivo Study.

    PubMed

    Puri, Rishi; Madder, Ryan D; Madden, Sean P; Sum, Stephen T; Wolski, Kathy; Muller, James E; Andrews, Jordan; King, Karilane L; Kataoka, Yu; Uno, Kiyoko; Kapadia, Samir R; Tuzcu, E Murat; Nissen, Steven E; Virmani, Renu; Maehara, Akiko; Mintz, Gary S; Nicholls, Stephen J

    2015-11-01

    Pathological studies demonstrate the dual significance of plaque burden (PB) and lipid composition for mediating coronary plaque vulnerability. We evaluated relationships between intravascular ultrasound (IVUS)-derived PB and arterial remodeling with near-infrared spectroscopy (NIRS)-derived lipid content in ex vivo and in vivo human coronary arteries. Ex vivo coronary NIRS and IVUS imaging was performed through blood in 116 coronary arteries of 51 autopsied hearts, followed by 2-mm block sectioning (n=2070) and histological grading according to modified American Heart Association criteria. Lesions were defined as the most heavily diseased 2-mm block per imaged artery on IVUS. IVUS-derived PB and NIRS-derived lipid core burden index (LCBI) of each block and lesion were analyzed. Block-level analysis demonstrated significant trends of increasing PB and LCBI across more complex atheroma (Ptrend <0.001 for both LCBI and PB). Lesion-based analyses demonstrated the highest LCBI and remodeling index within coronary fibroatheroma (Ptrend <0.001 and 0.02 versus all plaque groups, respectively). Prediction models demonstrated similar abilities of PB, LCBI, and remodeling index for discriminating fibroatheroma (c indices: 0.675, 0.712, and 0.672, respectively). A combined PB+LCBI analysis significantly improved fibroatheroma detection accuracy (c index 0.77, P=0.028 versus PB; net-reclassification index 43%, P=0.003), whereas further adding remodeling index did not (c index 0.80, P=0.27 versus PB+LCBI). In vivo comparisons of 43 age- and sex-matched patients (to the autopsy cohort) undergoing combined NIRS-IVUS coronary imaging yielded similar associations to those demonstrated ex vivo. Adding NIRS to conventional IVUS-derived PB imaging significantly improves the ability to detect more active, potentially vulnerable coronary atheroma. © 2015 American Heart Association, Inc.

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

    PubMed

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

    2015-01-01

    to compare noninfarct-related lesions in patients with acute myocardial infarction (MI) with culprit and non-culprit lesions in patients with stable angina pectoris (SAP) using intravascular ultrasound virtual histology (VH-IVUS). Overall 70 patients were enrolled: 38 with ST elevation (STE) MI and 32 with stable angina pectoris (SAP). All patients underwent three-vessel coronary angiography and gray-scale and VH-IVUS after percutaneous coronary intervention (PCI) of infarct-related lesion in STEMI or culprit lesion in SAP. A total of 130 plaques were examined: 70 in patients with STEMI and 60 in patients with SAP. Noninfarct-related lesions in acute MI compared with non-culprit lesions in SAP had significantly larger plaque burden and plaque volume, smaller minimum lumen area, and more positive remodeling. STEMI, hyperlipidemia, plaque burden, and hypertension were independent predictors of unstable plaques.

  8. Visualizing the stress distribution within vascular tissues using intravascular ultrasound elastography: a preliminary investigation.

    PubMed

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

    2015-06-01

    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.

  9. 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

  10. Joint registration of location and orientation of intravascular ultrasound pullbacks using a 3D graph based method

    NASA Astrophysics Data System (ADS)

    Zhang, Ling; Wahle, Andreas; Chen, Zhi; Zhang, Li; Downe, Richard; Kovarnik, Tomas; Sonka, Milan

    2015-03-01

    A novel method for simultaneous registration of location and orientation of baseline and follow-up intravascular ultrasound (IVUS) pullbacks is reported. The main idea is to represent the registration problem as a 3D graph optimization problem (finding a minimum-cost path) solvable by dynamic programming. Thus, global optimality of the resulting location and orientation registration is guaranteed according to the employed cost function and node connections. The cost function integrates information related to vessel/plaque morphology, plaque shape and plaque/perivascular image data. The node connections incorporate the prior information about angular twisting between consecutively co-registered IVUS image pairs. Pilot validation of our method is currently available for four pairs of IVUS pullback sequences consisting of 323 IVUS image frames from four patients. Results showed the average location and orientation registration errors were 0.26 mm and 5.2°, respectively. Compared with our previous results, the new method offers significant alignment improvement (p < 0.001).

  11. Safety and efficacy of carbon dioxide and intravascular ultrasound-guided stenting for renal artery stenosis in patients with chronic renal insufficiency.

    PubMed

    Kawasaki, Daizo; Fujii, Kenichi; Fukunaga, Masashi; Fukuda, Nobuhisa; Masuyama, Tohru; Ohkubo, Nobukazu; Kato, Masaaki

    2015-03-01

    We evaluated the feasibility, safety, and mid-term outcomes of renal artery stenting using carbon dioxide (CO₂) digital subtraction angiography and intravascular ultrasound (IVUS) for patients with renal insufficiency and significant atherosclerotic renal artery stenosis (RAS). Eighteen consecutive patients with chronic renal insufficiency underwent renal artery stenting under the guidance of CO₂ angiography and IVUS without contrast media. Renal function and blood pressure were assessed pre- and postintervention. A total of 27 de novo RAS in 18 patients (15 males; mean age: 72 ± 9 years) with renal insufficiency were treated by renal artery stenting with the combined use of the CO₂ angiography and IVUS without any procedural complications. Although the mean serum creatinine concentration preprocedure and 6 months after treatment did not change (2.7 ± 1.0-2.4 ± 1.1 mg/dL), blood pressure significantly decreased 6 months after stenting (158 ± 10-147 ± 11 mm Hg, P < .01).

  12. 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

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

    PubMed

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

    1995-02-01

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

  14. 18F-FDG PET and intravascular ultrasonography (IVUS) images compared with histology of atherosclerotic plaques: 18F-FDG accumulates in foamy macrophages.

    PubMed

    Ishino, Seigo; Ogawa, Mikako; Mori, Ikuo; Nishimura, Satoshi; Ikeda, Shota; Sugita, Taku; Oikawa, Tatsuo; Horiguchi, Takashi; Magata, Yasuhiro

    2014-04-01

    Intravascular ultrasonography (IVUS) and (18)F-FDG PET have been used to evaluate the efficacy of antiatherosclerosis drugs. These two modalities image different characteristics of atherosclerotic plaques, and a comparison of IVUS and PET images with histology has not been performed. The aim of this study was to align IVUS and PET images using anatomic landmarks in Watanabe heritable hyperlipidaemic (WHHL) rabbits, enabling comparison of their depiction of aortic atherosclerosis. Cellular (18)F-FDG localization was evaluated by (3)H-FDG microautoradiography (micro-ARG). A total of 19 WHHL rabbits (7 months of age) were divided into three groups: baseline (n = 6), 3 months (n = 4), and 6 months (n = 9). PET, IVUS and histological images of the same aortic segments were analysed. Infiltration by foamy macrophages was scored from 0 to IV using haematoxylin and eosin (H&E) and antimacrophage immunohistochemical staining, and compared with (3)H-FDG micro-ARG findings in two additional WHHL rabbits. IVUS images did not identify foamy macrophage deposition but revealed the area of intimal lesions (r = 0.87). (18)F-FDG PET revealed foamy macrophage distribution in the plaques. The intensity of (18)F-FDG uptake was correlated positively with the degree of foamy macrophage infiltration. Micro-ARG showed identical (3)H-FDG accumulation in the foamy macrophages surrounding the lipid core of the plaques. F-FDG PET localized and quantified the degree of infiltration of foamy macrophages in atherosclerotic lesions. IVUS defined the size of lesions. (18)F-FDG PET is a promising imaging technique for evaluating atherosclerosis and for monitoring changes in the composition of atherosclerotic plaques affecting their stability.

  15. Near-infrared spectroscopy-intravascular ultrasound: scientific basis and clinical applications.

    PubMed

    Kilic, Ismail Dogu; Caiazzo, Gianluca; Fabris, Enrico; Serdoz, Roberta; Abou-Sherif, Sara; Madden, Sean; Moreno, Pedro R; Goldstein, James; Di Mario, Carlo

    2015-12-01

    Coronary angiography underestimates the magnitude of the atherosclerotic burden and cannot detect the presence of disease in the early phases. Recognition of these inherent limitations of angiography has been an impetus for the development of other coronary imaging techniques. The novel near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) catheters can detect and quantify the presence of lipid core in the atherosclerotic plaque and associate it with other features such as lumen size and plaque architecture. Lipid-rich plaques are known to pose a higher risk of distal embolization during interventions and plaque disruption. The aim of this manuscript is the review of the potential clinical and research applications of this technology as highlighted by recent studies.

  16. Intravascular Ultrasound-Guided Percutaneous Coronary Intervention Improves the Clinical Outcome in Patients Undergoing Multiple Overlapping Drug-Eluting Stents Implantation

    PubMed Central

    Ahn, Sung Gyun; Sung, Joong Kyung; Lee, Ji-Hyun; Lee, Jun-Won; Youn, Young-Jin; Ahn, Min-Soo; Kim, Jang-Young; Yoo, Byung-Su; Lee, Seung-Hwan; Choe, Kyung-Hoon

    2013-01-01

    Background and Objectives Stented segment length is a predictive factor for restenosis and stent thrombosis still in the drug-eluting stent (DES) era, and the benefit of routine intravascular ultrasound (IVUS) is still unclear. The aim of the present study was to investigate whether IVUS-guided percutaneous coronary intervention (PCI) improved the vascular outcomes as compared with conventional PCI in the treatment of diffuse coronary artery disease. Subjects and Methods From our registry database from January 2006 to May 2009, we identified 85 consecutive patients with de novo coronary lesions treated with at least 64 mm of multiple, overlapping DES. The 2-year rate of major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, non-fatal myocardial infarction, target lesion revascularization (TLR), or stent thrombosis, was compared according to the use of IVUS. Results The 2-year MACE rate was lower in the IVUS-guided group than that of the angiography-guided group (8% vs. 33.3%, p=0.005). The incidence of TLR was lower in patients with IVUS use than in those without IVUS use (0% vs. 27.8%, p<0.001). On Cox proportional hazard analysis, no IVUS use {hazard ratio (HR) 5.917, 95% confidence interval (CI) 1.037-33.770, p=0.045} and age (HR 1.097, 95% CI 1.006-1.138, p=0.032) were unfavorable predictors for the 2-year MACE. Conclusion The use of IVUS may improve the effectiveness and safety of multiple overlapping drug-eluting stenting for long, diffuse coronary lesions. PMID:23682282

  17. Usefulness of intravascular ultrasound guidance in percutaneous coronary intervention with second-generation drug-eluting stents for chronic total occlusions (from the Multicenter Korean-Chronic Total Occlusion Registry).

    PubMed

    Hong, Sung-Jin; Kim, Byeong-Keuk; Shin, Dong-Ho; Kim, Jung-Sun; Hong, Myeong-Ki; Gwon, Hyeon-Cheol; Kim, Hyo-Soo; Yu, Cheol Woong; Park, Hun Sik; Chae, In-Ho; Rha, Seung-Woon; Lee, Seung-Hwan; Kim, Moo-Hyun; Hur, Seung-Ho; Jang, Yangsoo

    2014-08-15

    Despite the usefulness of intravascular ultrasound (IVUS) in percutaneous coronary intervention (PCI), the impact of IVUS guidance on clinical outcomes, particularly for chronic total occlusion (CTO) intervention, has rarely been studied. We sought to investigate the clinical usefulness of IVUS-guided CTO intervention with second-generation drug-eluting stent implantation. From 2007 to 2009, a total of 2,568 patients were enrolled in the Korean-CTO registry and 534 patients with successful implantation of second-generation drug-eluting stents were analyzed. IVUS-guided PCI was performed on 206 patients (39%). Clinical outcomes at 2 years were compared between the IVUS-guidance group and the angiography-guidance group in 201 propensity score-matched pairs. The primary end point was the occurrence of definite or probable stent thrombosis. Clinical characteristics were similar between both groups after matching. At 2 years, the IVUS-guidance group showed significantly less stent thrombosis than the angiography-guidance group (0% vs 3.0%, p = 0.014) and a lesser trend toward myocardial infarction (1.0% vs 4.0%, p = 0.058). Target lesion revascularization (TLR) and major adverse cardiovascular event rates were similar. However, a significant interaction was observed between the use of IVUS and lesion length for predicting the TLR (p = 0.037), suggesting usefulness of IVUS in long-lesion (≥3 cm) relative to short-lesion CTO. In conclusion, although IVUS-guided CTO PCI was not associated with a reduction in overall major adverse cardiovascular events, IVUS guidance appears to be associated with a reduction of stent thrombosis and myocardial infarction compared with angiography-guided CTO PCI. Additionally, TLR occurred less frequently in the IVUS-guidance group, especially for long lesions.

  18. Intravascular ultrasound is a critical tool for accurate endograft sizing in the management of blunt thoracic aortic injury.

    PubMed

    Wallace, Gabriel A; Starnes, Benjamin W; Hatsukami, Thomas S; Sobel, Michael; Singh, Niten; Tran, Nam T

    2015-03-01

    Accurate measurement of true aortic luminal diameter (ALD) is critical for endograft sizing in endovascular treatment of blunt thoracic aortic injury (BTAI), but ALD is dynamic and changes with respect to patients' hemodynamic status. This study aimed to characterize how ALD at the time of diagnosis of BTAI compares with ALD at the time of endovascular repair and later at follow-up. This is an Institutional Review Board-approved, single-institution retrospective analysis of prospectively obtained data. Patients were included who presented between July 2007 and December 2012 with computed tomography angiography (CTA)-diagnosed BTAI; who underwent thoracic endovascular aortic repair (TEVAR); and who underwent preoperative CTA, intraoperative intravascular ultrasound (IVUS), and postimplantation CTA. Comparison measurements of the ALD were made among CTA and IVUS images at the level of the left subclavian artery (LSCA) and between initial CTA and postimplantation CTA at 10, 15, and 20 cm distal to the LSCA. Theoretical endograft sizes were determined and compared for each ALD at the LSCA. Twenty-two patients were included in the analysis. Mean age was 38 ± 14 years (range, 17-61 years), with 82% men and mean Injury Severity Score of 43 ± 11 (range, 24-66). Mean time from emergency department admission to initial CTA was -1.2 ± 5 hours (range, -13 to 11.5 hours; negative time implies imaging at an outside facility before admission). Mean time from initial CTA to IVUS was 1.2 ± 1.4 days (range, 2.5 hours-5.7 days) and from IVUS to postimplantation CTA 33 ± 45 days (range, 17 hours-169 days). Overall, ALD measured by IVUS was significantly larger than that by initial CTA (Δ2.5 ± 3.1 mm; P < .05). ALD was also larger at 10, 15, and 20 cm distal to the LSCA in comparing the postimplantation CTA with the initial CTA (Δ2.4, 2.0, and 2.0 mm, respectively; all P < .05). More than half the devices would be sized differently with ALD measured by IVUS at the time of TEVAR

  19. Fully integrated optical coherence tomography, ultrasound, and indocyanine green based fluorescence tri-modality system for intravascular imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

    The rupture of atherosclerotic plaques is the leading cause of acute coronary events, so accurate assessment of plaque is critical. A large lipid pool, thin fibrous cap, and inflammatory reaction are the crucial characteristics for identifying vulnerable plaques. In our study, a tri-modality imaging system for intravascular imaging was designed and implemented. The tri-modality imaging system with a 1-mm probe diameter is able to simultaneously acquire optical coherence tomography (OCT), intravascular ultrasound (IVUS), and fluorescence imaging. Moreover, for fluorescence imaging, we used the FDA-approved indocyanine green (ICG) dye as the contrast agent to target lipid-loaded macrophages. Firstly, IVUS is used as the first step for identifying plaque since IVUS enables the visualization of the layered structures of the artery wall. Due to low soft-tissue contrast, IVUS only provides initial identification of the lipid plaque. Then OCT is used for differentiating fibrosis and lipid pool based on its relatively higher soft tissue contrast and high sensitivity/specificity. Last, fluorescence imaging is used for identifying inflammatory reaction to further confirm whether the plaque is vulnerable or not. Ex vivo experiment of a male New Zealand white rabbit aorta was performed to validate the performance of our tri-modality system. H and E histology results of the rabbit aorta were also presented to check assessment accuracy. The miniature tri-modality probe, together with the use of ICG dye suggest that the system is of great potential for providing a more accurate assessment of vulnerable plaques in clinical applications.

  20. 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

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

    PubMed

    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%.

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

    PubMed

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

    2016-09-20

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

  3. Intravascular Ultrasound Predictors of Major Adverse Cardiovascular Events After Implantation of Everolimus-eluting Stents for Long Coronary Lesions.

    PubMed

    Lee, Seung-Yul; Shin, Dong-Ho; Kim, Jung-Sun; Kim, Byeong-Keuk; Ko, Young-Guk; Choi, Donghoon; Jang, Yangsoo; Hong, Myeong-Ki

    2017-02-01

    There are limited data on the usefulness of intravascular ultrasound (IVUS) for long coronary lesions treated with second-generation drug-eluting stents. We evaluated IVUS predictors of major adverse cardiovascular events (MACE) 12 months after implantation of everolimus-eluting stents for long coronary lesions. A total of 804 patients who underwent both postintervention IVUS examination and long everolimus-eluting stent (≥ 28mm in length) implantation were included from 2 randomized trials. MACE was defined as a composite of cardiac death, myocardial infarction, and target-lesion revascularization. MACE occurred in 24 patients (3.0%) over 12 months. On multivariable Cox regression analysis, independent IVUS predictors of MACE included the postintervention minimum lumen area (MLA) at the target lesion (HR = 0.623; 95%CI, 0.433-0.895; P=.010) and the ratio of MLA/distal reference segment lumen area (HR = 0.744; 95%CI, 0.572-0.969; P=.028). The MLA and MLA-to-distal reference segment lumen area ratio that best predicted patients with MACE from those without these events were 5.0 mm(2) and 1.0, respectively. Patients with MLA<5.0 mm(2) or a distal reference segment lumen area had a higher risk of MACE (HR = 6.231; 95%CI, 1.859-20.891; P=.003) than those without MACE. Patients with a postintervention IVUS-measured MLA of<5.0 mm(2) or a distal reference segment lumen area were at risk for MACE after long everolimus-eluting stent implantation. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

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

    PubMed

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

    1994-01-01

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

  5. A four-criterion selection procedure for atherosclerotic plaque elasticity reconstruction based on in vivo coronary intravascular ultrasound radial strain sequences.

    PubMed

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

    2012-12-01

    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 four-criterion selection procedure (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.

  6. 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

  7. 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.

  8. Virtual angioscopic visualization and analysis of coronary aneurysms using intravascular ultrasound images

    NASA Astrophysics Data System (ADS)

    Ayeni, Tina A.; Holmes, David R., III; Robb, Richard A.

    2001-05-01

    Kawasaki Disease is an inflammatory illness of young children that can seriously affect the cardiovascular system. The disease may cause coronary artery aneurysms, a thinning and dilation of the arterial wall when the wall is weakened by disease. Such aneurysms significantly increase the risk of rupture of the arterial wall, an event from which few patients survive. Due to the largely asymptotic nature of coronary aneurysms, diagnosis must be timely and accurate in order for treatment to be effective. Currently, aneurysms are detected primarily using X-ray angiography, MRI, and CT images. Increased insight into the disease and its effects on the arterial wall can be gained by multi-dimensional computerized visualization and quantitative analysis of diagnostic images made possible by the techniques of intravascular imaging and virtual endoscopy. Intravascular ultrasound images (IVUS) of a coronary artery exhibiting aneurysms were acquired from a patient with Kawasaki Disease. The disease is characterized by low luminescent in the IVUS images. Image segmentation of the abnormal, prominent anechoic regions branching from the lumen and originating within other layers of the arterial wall was performed and each region defined as a separate object. An object segmentation map was generated and used in perspective rendering of the original image volume set at successive locations along the length of the arterial segment, producing a 'fly-through' of the interior of the artery. The diseased region (aneurysm) of the wall was well defined by the differences in luminal size and by differences in appearance of the arterial wall shape observed during virtual angioscopic fly-throughs. Erosions of the endovascular surface caused pronounced horizontal and vertical ballooning of the lumen. Minute cracks within the unaffected luminal areas revealed possible early development of an aneurysm on the contralateral wall, originating in the medial section of the artery and spreading

  9. Three-dimensional imaging in aortic disease by lighthouse transesophageal echocardiography using intravascular ultrasound catheters. Comparison to three-dimensional transesophageal echocardiography and three-dimensional intra-aortic ultrasound imaging.

    PubMed

    Buck, T; Görge, G; Hunold, P; Erbel, R

    1998-03-01

    Two-dimensional (2D) transesophageal echocardiography (TEE) and 2D intravascular ultrasound (IVUS) imaging face their greatest limitation in visualizing aortic disease in patients. With the aid of three-dimensional (3D) image reconstruction, TEE and IVUS can potentially overcome this limitation but still provide only limited spatial appreciation in aortic disease because 3D imaging of the thoracic aorta requires a broader spatial visualization of the mediastinum than provided by both techniques. Moreover, for timely decision making about aortic disease TEE is limited by a large probe, which requires sedation. Therefore, we developed an approach called 3D lighthouse transesophageal echocardiography (LTEE) using a thin intravascular ultrasound catheter, which provides a full circumferential (360 degree) image and requires no sedation. The purpose of this study was to compare the feasibility and accuracy of 3D TEE, 3D IVUS, and 3D LTEE for obtaining spatial visualization of the thoracic aorta to detect aortic diseases in patients. 3D image datasets were obtained for 3D LTEE by a manual pullback of a 3.3 mm thick, 10 MHz intravascular ultrasound catheter positioned in the esophagus; for 3D TEE using a conventional 15 mm thick probe; and for 3D IVUS using a 2.6 mm thick, 20 MHz intravascular ultrasound catheter. In 12 consecutive patients, three with aortic dissection (two with type III, one with type I) and 11 with suspected artherosclerosis, we analyzed and compared spatial visualization of the thoracic aorta, 3D image quality, patient discomfort, and study time. Providing a 3D dataset of 360-degree tomographic images of the mediastinum, 3D LTEE was the only approach that allowed broad spatial visualization of the aortic arch (9 of 12 patients) with the detection of aortic dissection or atherosclerotic plaques. Spatial visualization of the aortic arch by 3D TEE was incomplete because of the relatively narrow 90-degree image sector. However, in other segments 3D image

  10. IVUS-based imaging modalities for tissue characterization: similarities and differences.

    PubMed

    Garcìa-Garcìa, Hector M; Gogas, Bill D; Serruys, Patrick W; Bruining, Nico

    2011-02-01

    Gray-scale intravascular ultrasound (IVUS) is the modality that has been established as the golden standard for in vivo imaging of the vessel wall of the coronary arteries. The use of IVUS in clinical practice is an important diagnostic tool used for quantitative assessment of coronary artery disease. This has made IVUS the de-facto invasive imaging method to evaluate new interventional therapies such as new stent designs and for atherosclerosis progression-regression studies. However, the gray-scale representation of the coronary vessel wall and plaque morphology in combination with the limited resolution of the current IVUS catheters makes it difficult, if not impossible, to identify qualitatively (e.g. visually) the plaque morphology similar as that of histopathology, the golden standard to characterize and quantify coronary plaque tissue components. Meanwhile, this limitation has been partially overcome by new innovative IVUS-based post-processing methods such as: virtual histology IVUS (VH-IVUS, Volcano Therapeutics, Rancho Cordova, CA, USA), iMAP-IVUS (Bostoc Scientific, Santa Clara, CA, USA), Integrated Backscatter IVUS (IB-IVUS) and Automated Differential Echogenicity (ADE).

  11. Combined frequency domain photoacoustic and ultrasound imaging for intravascular applications

    PubMed Central

    Castelino, Robin F.; Hynes, Michael; Munding, Chelsea E.; Telenkov, Sergey; Foster, F. Stuart

    2016-01-01

    Intravascular photoacoustic (IVPA) imaging has the potential to characterize lipid-rich structures based on the optical absorption contrast of tissues. In this study, we explore frequency domain photoacoustics (FDPA) for intravascular applications. The system employed an intensity-modulated continuous wave (CW) laser diode, delivering 1W over an intensity modulated chirp frequency of 4-12MHz. We demonstrated the feasibility of this approach on an agar vessel phantom with graphite and lipid targets, imaged using a planar acoustic transducer co-aligned with an optical fibre, allowing for the co-registration of IVUS and FDPA images. A frequency domain correlation method was used for signal processing and image reconstruction. The graphite and lipid targets show an increase in FDPA signal as compared to the background of 21dB and 16dB, respectively. Use of compact CW laser diodes may provide a valuable alternative for the development of photoacoustic intravascular devices instead of pulsed laser systems. PMID:27895986

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

    PubMed

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

    2015-01-01

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

  13. Measurement of the 3D arterial wall strain tensor using intravascular B-mode ultrasound images: a feasibility study

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    Intravascular ultrasound (IVUS) elastography is a promising tool for studying atherosclerotic plaque composition and assessing plaque vulnerability. Current IVUS elastography techniques can measure the 1D or 2D strain of the vessel wall using various motion tracking algorithms. Since biological soft tissue tends to deform non-uniformly in 3D, measurement of the complete 3D strain tensor is desirable for more rigorous analysis of arterial wall mechanics. In this paper, we extend our previously developed method of 2D arterial wall strain measurement based on non-rigid image registration into 3D strain measurement. The new technique registers two image volumes acquired from the same vessel segment under different levels of luminal pressure and longitudinal stress. The 3D displacement field obtained from the image registration is used to calculate the local 3D strain tensor. From the 3D strain tensor, radial, circumferential and longitudinal strain distributions can be obtained and displayed. This strain tensor measurement method is validated and evaluated using IVUS images of healthy porcine carotid arteries subjected to a luminal pressure increase and longitudinal stretch. The ability of the algorithm to overcome systematic noise was tested, as well as the consistency of the results under different longitudinal frame resolutions.

  14. Joint learning of ultrasonic backscattering statistical physics and signal confidence primal for characterizing atherosclerotic plaques using intravascular ultrasound.

    PubMed

    Sheet, Debdoot; Karamalis, Athanasios; Eslami, Abouzar; Noël, Peter; Chatterjee, Jyotirmoy; Ray, Ajoy K; Laine, Andrew F; Carlier, Stephane G; Navab, Nassir; Katouzian, Amin

    2014-01-01

    Intravascular Ultrasound (IVUS) is a predominant imaging modality in interventional cardiology. It provides real-time cross-sectional images of arteries and assists clinicians to infer about atherosclerotic plaques composition. These plaques are heterogeneous in nature and constitute fibrous tissue, lipid deposits and calcifications. Each of these tissues backscatter ultrasonic pulses and are associated with a characteristic intensity in B-mode IVUS image. However, clinicians are challenged when colocated heterogeneous tissue backscatter mixed signals appearing as non-unique intensity patterns in B-mode IVUS image. Tissue characterization algorithms have been developed to assist clinicians to identify such heterogeneous tissues and assess plaque vulnerability. In this paper, we propose a novel technique coined as Stochastic Driven Histology (SDH) that is able to provide information about co-located heterogeneous tissues. It employs learning of tissue specific ultrasonic backscattering statistical physics and signal confidence primal from labeled data for predicting heterogeneous tissue composition in plaques. We employ a random forest for the purpose of learning such a primal using sparsely labeled and noisy samples. In clinical deployment, the posterior prediction of different lesions constituting the plaque is estimated. Folded cross-validation experiments have been performed with 53 plaques indicating high concurrence with traditional tissue histology. On the wider horizon, this framework enables learning of tissue-energy interaction statistical physics and can be leveraged for promising clinical applications requiring tissue characterization beyond the application demonstrated in this paper.

  15. 12-month intravascular ultrasound observations from BiOSS® first-in-man studies.

    PubMed

    Gil, Robert J; Bil, Jacek; Costa, Ricardo A; Gil, Katarzyna E; Vassiliev, Dobrin

    2016-09-01

    The aim of this study was to analyze the difference in neointima pattern assessed by intravascular ultrasound (IVUS) between two dedicated bifurcation stents, BiOSS® Expert and BiOSS® LIM at 12-month follow-up. This manuscript reports IVUS findings obtained from the analysis of patients enrolled into first-in-man registries initially assessing the BiOSS Expert® (paclitaxel) and BiOSS LIM® (sirolimus) stents. Quantitative angiographic analysis was performed pre, post-stenting, and at follow-up. IVUS examination was performed at 12 months. There were analyzed 34 cases (BiOSS Expert® 11 patients, BiOSS LIM® 23 patients). Procedural characteristics in the two groups were similar, except for rates of main vessel predilatation and FKB/POT, which were higher in BiOSS® LIM group, 54.5 % vs 73.9 % (P < 0.05) and 0 % vs 39.1 % (P < 0.05), respectively. When comparing late lumen loss (LLL) for both stents there were significantly bigger values for main vessel and main branch in the BiOSS® Expert group, but not in side branch. Intravascular ultrasound examination showed that in the BiOSS LIM® group comparing with the BiOSS Expert® group there was lower neointima burden in the whole stent (24.7 ± 7.5 % vs 19.4 ± 8.6 %, P < 0.05) as well as in main vessel (22.8 ± 5.6 % vs 16.9 ± 6.1 %, P < 0.05) and main branch (36.1 ± 6.5 % vs 27.6 ± 8.7 %, P < 0.05), but not at the level of bifurcation (15.1 ± 3.8 % vs 13.6 ± 5.4 %, P = NS). In addition, we found that final kissing balloon/proximal optimization technique (FKB/POT) was associated with significantly smaller value of LLL in main vessel (0.24 ± 0.09 mm vs 0.32 ± 0.14 mm, P < 0.05), which in IVUS analysis resulted in smaller neointima burden in main vessel (13.7 ± 3.9 % vs 18.9 ± 4.45 %, P < 0.05) as well as at the bifurcation site (12.6 ± 4.1 % vs 14.1 ± 2.4 %, P < 0.05). The

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

    PubMed

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

    1995-10-01

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

  17. Assessment of bioresorbable scaffold with a novel high-definition 60 MHz IVUS imaging system: Comparison with 40-MHz IVUS referenced to optical coherence tomography.

    PubMed

    Okada, Kozo; Kitahara, Hideki; Mitsutake, Yoshiaki; Tanaka, Shigemitsu; Kimura, Takumi; Yock, Paul G; Fitzgerald, Peter J; Ikeno, Fumiaki; Honda, Yasuhiro

    2017-07-14

    In vivo assessment of bioresorbable scaffold (BRS) is of growing clinical interest. The novel 60MHz high-definition intravascular ultrasound (HD-IVUS) has been developed to overcome the limitations of conventional 40 MHz IVUS. This study aimed to evaluate the performance and limitations of 60 MHz HD-IVUS compared with 40 MHz IVUS with respect to polymeric-strut visualization, quantitative and qualitative analysis, and feasibility of high-speed pullback in the assessment of BRS. In a bench-test model, 361 struts were analyzed to evaluate the influence of ultrasound-beam angles and proximity of adjacent struts on IVUS visualization of BRS struts. Various settings were created by deforming the BRS and positioning the transducer offcenter. In an in vivo swine coronary model, scaffold and lumen areas, degree of visible external elastic membrane, incomplete strut apposition, and strut fracture were evaluated in 59 matched cross-sections obtained at conventional (0.5 mm/sec) and high speed (10 mm/sec) pullbacks. Both studies utilized optical coherence tomography (OCT) as reference. Overall, 60 MHz HD-IVUS demonstrated significantly improved visualization of polymeric struts compared with 40 MHz IVUS (well-visualized: 84.5% vs 62.3%, not visible: 4.4% vs 13.9%, respectively. P < 0.001), which was less affected by the beam angle and adjacent strut proximity. In the in vivo model, 60-MHz HD-IVUS showed better agreement of area measurements and strut abnormalities with OCT than 40 MHz IVUS. These findings were also confirmed on high-speed pullback images of 60 MHz HD-IVUS. As referenced to OCT, this study showed superiority of 60 MHz HD-IVUS over 40 MHz IVUS in the assessment of BRS with feasibility of high-speed pullback imaging. © 2017 Wiley Periodicals, Inc.

  18. Impact of statins on progression of atherosclerosis: rationale and design of SATURN (Study of Coronary Atheroma by InTravascular Ultrasound: effect of Rosuvastatin versus AtorvastatiN).

    PubMed

    Nicholls, Stephen J; Borgman, Marilyn; Nissen, Steven E; Raichlen, Joel S; Ballantyne, Christie; Barter, Philip; Chapman, M John; Erbel, Raimund; Libby, Peter

    2011-06-01

    Previous imaging studies have demonstrated that the beneficial impact of high-dose statins on the progression of coronary atherosclerosis associates with their ability to lower levels of low-density lipoprotein cholesterol (LDL-C) and C-reactive protein (CRP) and to raise high-density lipoprotein cholesterol (HDL-C). The Study of Coronary Atheroma by InTravascular Ultrasound: Effect of Rosuvastatin versus AtorvastatiN (SATURN, NCT00620542) aims to compare the effects of high-dose atorvastatin and rosuvastatin on disease progression. A total of 1385 subjects with established coronary artery disease (CAD) on angiography were randomized to receive rosuvastatin 40 mg or atorvastatin 80 mg for 24 months. The primary efficacy parameter will be the nominal change in percent atheroma volume (PAV), determined by analysis of intravascular ultrasound (IVUS) images of matched coronary artery segments acquired at baseline and at 24-month follow-up. The effect of statin therapy on plasma lipids and inflammatory markers, and the incidence of clinical cardiovascular events will also be assessed. The study does not have the statistical power to directly compare the treatment groups with regard to clinical events. Serial IVUS has emerged as a sensitive imaging modality to assess the impact of treatments on arterial structure. In this study, IVUS will be used to determine whether high-dose statins have different effects on plaque progression.

  19. 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.

  20. Coronary Plaque Boundary Enhancement in IVUS Image by Using a Modified Perona-Malik Diffusion Filter

    PubMed Central

    Anam, S.; Uchino, E.; Suetake, N.

    2014-01-01

    We propose a modified Perona-Malik diffusion (PMD) filter to enhance a coronary plaque boundary by considering the conditions peculiar to an intravascular ultrasound (IVUS) image. The IVUS image is commonly used for a diagnosis of acute coronary syndrome (ACS). The IVUS image is however very grainy due to heavy speckle noise. When the normal PMD filter is applied for speckle noise reduction in the IVUS image, the coronary plaque boundary becomes vague. For this problem, we propose a modified PMD filter which is designed in special reference to the coronary plaque boundary detection. It can then not only reduce the speckle noise but also enhance clearly the coronary plaque boundary. After applying the modified PMD filter to the IVUS image, the coronary plaque boundaries are successfully detected further by applying the Takagi-Sugeno fuzzy model. The accuracy of the proposed method has been confirmed numerically by the experiments. PMID:25506357

  1. Coronary Plaque Boundary Enhancement in IVUS Image by Using a Modified Perona-Malik Diffusion Filter.

    PubMed

    Anam, S; Uchino, E; Suetake, N

    2014-01-01

    We propose a modified Perona-Malik diffusion (PMD) filter to enhance a coronary plaque boundary by considering the conditions peculiar to an intravascular ultrasound (IVUS) image. The IVUS image is commonly used for a diagnosis of acute coronary syndrome (ACS). The IVUS image is however very grainy due to heavy speckle noise. When the normal PMD filter is applied for speckle noise reduction in the IVUS image, the coronary plaque boundary becomes vague. For this problem, we propose a modified PMD filter which is designed in special reference to the coronary plaque boundary detection. It can then not only reduce the speckle noise but also enhance clearly the coronary plaque boundary. After applying the modified PMD filter to the IVUS image, the coronary plaque boundaries are successfully detected further by applying the Takagi-Sugeno fuzzy model. The accuracy of the proposed method has been confirmed numerically by the experiments.

  2. Mechanism of lumen gain with a novel rotational aspiration atherectomy system for peripheral arterial disease: examination by intravascular ultrasound.

    PubMed

    Hassan, Ali H M; Ako, Junya; Waseda, Katsuhisa; Honda, Yasuhiro; Zeller, Thomas; Leon, Martin B; Fitzgerald, Peter J

    2010-01-01

    The purpose of this study was to evaluate the mechanism of luminal gain with a novel atheroablation system (Pathway PV) for the treatment of peripheral artery disease using intravascular ultrasound (IVUS). The atherectomy system is a rotational atherectomy device, which employs expandable rotating blades with ports that allow flushing and aspiration of the plaque material or thrombus. In this first-in-man clinical study, IVUS analysis was available in 6 patients with lower limb ischemia treated with this device. The treatment results were assessed using IVUS at pre and post atherectomy. Lumen beyond burr size (LBB) was defined as lumen gain divided by the estimated burr area determined by the burr-size. IVUS analysis was available in six patients (superficial femoral artery n=3, popliteal artery n=2, posterior tibial artery n=1). Atheroablation achieved a significant increase in lumen area (LA) (preintervention 3.9+/-0.4, postatheroablation 8.0+/-1.7 mm(2), P<.05), and significant reduction in plaque area (27.5+/-4.0, 23.7+/-3.1 mm(2), P=.001), while there was no change in the vessel area (31.3+/-4.2, 32.1+/-2.8 mm(2), P=.4). LBB was 57.4+/-51.3%. This novel rotational aspiration atherectomy device achieved significant luminal gain by debulking in the absence of vessel stretching. The LA was greater than burr-sized lumen expectancy at cross-sections along the treated segments, suggesting a complimentary role of aspiration in luminal gain in atherosclerotic peripheral artery lesions.

  3. Donor-Transmitted Atherosclerosis Associated With Worsening Cardiac Allograft Vasculopathy After Heart Transplantation: Serial Volumetric Intravascular Ultrasound Analysis

    PubMed Central

    Watanabe, Takuya; Seguchi, Osamu; Yanase, Masanobu; Fujita, Tomoyuki; Murata, Yoshihiro; Sato, Takuma; Sunami, Haruki; Nakajima, Seiko; Kataoka, Yu; Nishimura, Kunihiro; Hisamatsu, Eriko; Kuroda, Kensuke; Okada, Norihiro; Hori, Yumiko; Wada, Kyoichi; Hata, Hiroki; Ishibashi-Ueda, Hatsue; Miyamoto, Yoshihiro; Fukushima, Norihide; Kobayashi, Junjiro; Nakatani, Takeshi

    2017-01-01

    Background The influence of preexisting donor-transmitted atherosclerosis (DA) on cardiac allograft vasculopathy (CAV) development remains unclear. Methods We performed 3-dimensional intravascular ultrasound (3D-IVUS) analysis in 42 heart transplantation (HTx) recipients at 2.1 ± 0.9 months (baseline) and 12.2 ± 0.4 months post-HTx, as well as consecutive 3D-IVUS analyses up to 3 years post-HTx in 35 of the 42 recipients. Donor-transmitted atherosclerosis was defined as a maximal intimal thickness of 0.5 mm or greater at baseline. Changes in volumetric IVUS parameters were compared in recipients with (DA group) and without DA (DA-free group) at baseline, 1 year, and 3 years post-HTx. Results Donor-transmitted atherosclerosis was observed in 57.1% of 42 recipients. The DA group exhibited a significantly greater increase in plaque volume at 1 year post-HTx (P < 0.001), leading to increased percent plaque volume (plaque volume/vessel volume, [%]) (P < 0.001) and decreased luminal volume (P = 0.021). Donor-transmitted atherosclerosis was independently associated with a greater increase in percent plaque volume during the first post-HTx year (P = 0.011). From 1 to 3 years post-HTx, the DA group underwent continuous reduction in luminal volume (P = 0.022). These changes resulted in a higher incidence of angiographic CAV at 3 years post-HTx in the DA group (58.8% vs 5.6%, P = 0.002). Conclusions This volumetric IVUS study suggests that DA correlates with the worsening change in CAV several years post-HTx. Donor-transmitted atherosclerosis recipients may require more aggressive treatment to prevent subsequent CAV progression. PMID:27472091

  4. A study of coronary artery rotational motion with dense scale-space optical flow in intravascular ultrasound

    NASA Astrophysics Data System (ADS)

    Danilouchkine, M. G.; Mastik, F.; van der Steen, A. F. W.

    2009-03-01

    This paper describes a novel method for estimating tissue motion in two-dimensional intravascular ultrasound (IVUS) images of a coronary artery. It is based on the classical Lukas-Kanade (LK) algorithm for optical flow (OF). The OF vector field quantifies the amount of misalignment between two consecutive frames in a sequence of images. From the theoretical standpoint, two fundamental improvements are proposed in this paper. First, using a simplified representation of the vessel wall as a medium with randomly distributed scatterers, it was shown that the OF equation satisfies the integral brightness conservation law. Second, a scale-space embedding for the OF equation was derived under the assumption of spatial consistency in IVUS acquisitions. The spatial coherence is equivalent to a locally affine motion model. The latter effectively captures and appropriately describes a complex deformation pattern of the coronary vessel wall under the varying physiological conditions (i.e. pulsatile blood pressure). The accuracy of OF tracking was estimated on the tissue-mimicking phantoms subjected to the controlled amount of angular deviation. Moreover, the performance of the classical LK and proposed approach was compared using the simulated IVUS images with an atherosclerotic lesion. The experimental results showed robust and reliable performance of up to 5° of rotation, which is within the plausible range of circumferential displacement of the coronary arteries. Subsequently, the algorithm was used to analyze vessel wall motion in 18 IVUS pullbacks from 16 patients. The in vivo experiments revealed that the motion of coronary arteries is primarily determined by the cardiac contraction.

  5. A study of coronary artery rotational motion with dense scale-space optical flow in intravascular ultrasound.

    PubMed

    Danilouchkine, M G; Mastik, F; van der Steen, A F W

    2009-03-21

    This paper describes a novel method for estimating tissue motion in two-dimensional intravascular ultrasound (IVUS) images of a coronary artery. It is based on the classical Lukas-Kanade (LK) algorithm for optical flow (OF). The OF vector field quantifies the amount of misalignment between two consecutive frames in a sequence of images. From the theoretical standpoint, two fundamental improvements are proposed in this paper. First, using a simplified representation of the vessel wall as a medium with randomly distributed scatterers, it was shown that the OF equation satisfies the integral brightness conservation law. Second, a scale-space embedding for the OF equation was derived under the assumption of spatial consistency in IVUS acquisitions. The spatial coherence is equivalent to a locally affine motion model. The latter effectively captures and appropriately describes a complex deformation pattern of the coronary vessel wall under the varying physiological conditions (i.e. pulsatile blood pressure). The accuracy of OF tracking was estimated on the tissue-mimicking phantoms subjected to the controlled amount of angular deviation. Moreover, the performance of the classical LK and proposed approach was compared using the simulated IVUS images with an atherosclerotic lesion. The experimental results showed robust and reliable performance of up to 5 degrees of rotation, which is within the plausible range of circumferential displacement of the coronary arteries. Subsequently, the algorithm was used to analyze vessel wall motion in 18 IVUS pullbacks from 16 patients. The in vivo experiments revealed that the motion of coronary arteries is primarily determined by the cardiac contraction.

  6. Detection and quantification of coronary atherosclerotic plaque by 64-slice multidetector CT: a systematic head-to-head comparison with intravascular ultrasound.

    PubMed

    Papadopoulou, Stella-Lida; Neefjes, Lisan A; Schaap, Michiel; Li, Hui-Ling; Capuano, Ermanno; van der Giessen, Alina G; Schuurbiers, Johan C H; Gijsen, Frank J H; Dharampal, Anoeshka S; Nieman, Koen; van Geuns, Robert Jan; Mollet, Nico R; de Feyter, Pim J

    2011-11-01

    We evaluated the ability of 64-slice multidetector computed tomography (MDCT)-derived plaque parameters to detect and quantify coronary atherosclerosis, using intravascular ultrasound (IVUS) as the reference standard. In 32 patients, IVUS and 64-MDCT was performed. The MDCT and IVUS datasets of 44 coronary arteries were co-registered using a newly developed fusion technique and quantitative parameters were derived from both imaging modalities. The threshold of >0.5 mm of maximum wall thickness was used to establish plaque presence on MDCT and IVUS. We analyzed 1364 coregistered 1-mm coronary cross-sections and 255 segments of 5-mm length. Compared with IVUS, 64-MDCT enabled correct detection in 957 of 1109 cross-sections containing plaque (sensitivity 86%). In 180 of 255 cross-sections atherosclerosis was correctly excluded (specificity 71%). On the segmental level, MDCT detected 213 of 220 segments with any atherosclerotic plaque (sensitivity 96%), whereas the presence of any plaque was correctly ruled out in 28 of 32 segments (specificity 88%). Interobserver agreement for the detection of atherosclerotic cross-sections was moderate (Cohen's kappa coefficient K=0.51), but excellent for the atherosclerotic segments (K=1.0). Pearson's correlation coefficient for vessel plaque volumes measured by MDCT and IVUS was r=0.91 (p<0.001). Bland-Altman analysis showed a slight non-significant underestimation of any plaque volume by MDCT (p=0.5), with a trend to underestimate noncalcified and overestimate mixed/calcified plaque volumes (p=0.22 and p=0.87 respectively). MDCT is able to detect and quantify atherosclerotic plaque. Further improvement in CT resolution is necessary for more reliable assessment of very small and distal coronary plaques. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. The Role of Intracoronary Plaque Imaging with Intravascular Ultrasound, Optical Coherence Tomography, and Near-Infrared Spectroscopy in Patients with Coronary Artery Disease.

    PubMed

    Hoang, Vu; Grounds, Jill; Pham, Don; Virani, Salim; Hamzeh, Ihab; Qureshi, Athar Mahmood; Lakkis, Nasser; Alam, Mahboob

    2016-09-01

    The development of multiple diagnostic intracoronary imaging modalities has increased our understanding of coronary atherosclerotic disease. These imaging modalities, intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near-infrared spectroscopy (NIRS), have provided a method to study plaques and introduced the concept of plaque vulnerability. They are being increasingly used for percutaneous coronary intervention (PCI) optimization and are invaluable tools in research studying the pathophysiology of acute coronary syndrome (ACS), in-stent thrombosis and in-stent restenosis. IVUS has the ability to visualize the intracoronary lumen and the vessel wall and can be used to detect early atherosclerotic disease even in the setting of positive arterial remodeling. Studies supporting the use of IVUS to optimize stent deployment and apposition have shown a significant reduction in cardiovascular events. OCT provides even higher resolution imaging and near microscopic detail of plaques, restenoses, and thromboses; thus, it can identify the etiology of ACS. Ongoing trials are evaluating the role of OCT in PCI and using OCT to study stent endothelialization and neointimal proliferation. NIRS is a modality capable of localizing and quantifying lipid core burden. It is usually combined with IVUS and is used to characterize plaque composition. The benefits of NIRS in the setting of ACS have been limited to case reports and series. The utilization of all these intracoronary imaging modalities will continue to expand as their indications for clinical use and research grow. Studies to support their use for PCI optimization resulting in improved outcomes with potential to prevent downstream events are ongoing.

  8. High frequency intravascular photoacoustic (IVPA) imaging for differentiating arterial wall layered structures

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Wei, Wei; Zhou, Qifa; Shung, K. Kirk; Chen, Zhongping

    2012-02-01

    Arterial wall is composed of three layers: intima, media and adventitia. Intima-media thickness (IMT) is an important prognostic indicator of atherosclerotic diseases. Although intravascular ultrasound (IVUS) imaging is a commonly used method for delineation of the layered structures, it is inferior to the optical absorption contrast offered by intravascular photoacoustic (IVPA) imaging. We introduce an integrated miniature probe that combines the capabilities of IVUS and IVPA imaging for the evaluation of arterial wall layered structures. Healthy rabbit aorta was imaged ex vivo. IVPA results showed superior contrast over IVUS in identifying the layered structures of arterial wall.

  9. Volumetric imaging using single chip integrated CMUT-on-CMOS IVUS array.

    PubMed

    Tekes, Coskun; Zahorian, Jaime; Gurun, Gokce; Satir, Sarp; Xu, Toby; Hochman, Michael; Degertekin, F Levent

    2012-01-01

    An intravascular ultrasound (IVUS) catheter that can provide forward viewing volumetric ultrasound images would be an invaluable clinical tool for guiding interventions. Single chip integration of front-end electronics with capacitive micromachined ultrasonic transducers (CMUTs) is highly desirable to reduce the interconnection complexity and enable miniaturization in IVUS catheters. For this purpose we use the monolithic CMUT-on-CMOS integration where CMUTs are fabricated directly on top of pre-processed CMOS wafers. This minimizes parasitic capacitances associated with connection lines. We have recently implemented a system design including all the required electronics using 0.35-µm CMOS process integrated with a 1.4-mm diameter CMUT array. In this study, we present the experimental volumetric imaging results from an ex-vivo chicken heart phantom. The imaging results demonstrate that the single-chip forward looking IVUS (FL-IVUS) system with monolithically integrated electronics has potential to visualize the front view of coronary arteries.

  10. Integrated intravascular optical coherence tomography ultrasound imaging system

    PubMed Central

    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. PMID:20210424

  11. 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

  12. 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

  13. Analysis of Plaque Composition in Coronary Chronic Total Occlusion Lesion Using Virtual Histology-Intravascular Ultrasound

    PubMed Central

    Park, Yo-Han; Kim, Yong-Kyun; Seo, Duck-Jun; Seo, Young-Hoon; Lee, Chung-Seop; Song, In-Geol; Yang, Dong-Ju; Kim, Ki-Hong; Park, Hyun-Woong; Kim, Wan-Ho

    2016-01-01

    Background and Objectives Success rates of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have recently been reported to range from 80% to 90%. A better understanding of the pathologic characteristics of the CTO lesion may helpful to improving CTO PCI success rates. We evaluated the CTO lesion in patients with stable angina (SA) by virtual histology-intravascular ultrasound (VH-IVUS). Subjects and Methods The study population consisted of 149 consecutive patients with SA underwent VH-IVUS examination. We analyzed demographic and VH-IVUS findings in 22 CTO patients (17 males; mean, 62.3 years old) compared with 127 non-CTO patients (82 males; mean, 61.3 years old). Results A significantly lower ejection fraction (57.6±13.0% vs. 65.4±8.8%, p=0.007) was detected in the CTO group compared with the non-CTO group. Reference vessel lumen area of the proximal and distal segment was significantly less in CTO group than in non-CTO group. The lesion length of the CTO group was significantly longer than those of the non-CTO group (24.4±9.6 mm vs. 17.2±7.4 mm, p<0.001). Total atheroma volume (224±159 mm3 vs. 143±86 mm3, p=0.006) and percent atheroma volume (63.2±9.6% vs. 55.8±8.5%, p=0.011) of the CTO group were also significantly greater than those of non-CTO group. However, the lesion length adjusted plaque composition of the CTO group was not significantly different compared with that of the non-CTO group. Conclusion CTO lesions had a longer lesion length and greater plaque burden than the non-CTO lesion in patients with SA. However, lesion length adjusted plaque composition showed similar between the two groups. These results support that plaque characteristics of CTO lesions are similar to non-CTO lesions in patients with SA. PMID:26798383

  14. Intravascular Ultrasound Observation of the Mechanism of No-Reflow Phenomenon in Acute Myocardial Infarction

    PubMed Central

    Li, Junxia; Wu, Longmei; Tian, Xinli; Zhang, Jian; Shi, Yujie

    2015-01-01

    Objective To study the mechanism of the no-reflow phenomenon using coronary angiography (CAG) and intravascular ultrasound (IVUS). Methods A total of 120 patients with acute myocardial infarction (AMI) who successfully underwent indwelling intracoronary stent placement by percutaneous coronary intervention (PCI). All patients underwent pre- and post-PCI CAG and pre-IVUS. No-reflow was defined as post-PCI thrombolysis in myocardial infarction (TIMI) grade 0, 1, or 2 flow in the absence of mechanical obstruction. Normal reflow was defined as TIMI grade 3 flow. The pre-operation reference vascular area, minimal luminal cross-sectional area, plaque cross-sectional area, lesion length, plaque volume and plaque traits were measured by IVUS. Results The no-reflow group was observed in 14 cases (11.6%) and normal blood-flow group in 106 cases (89.4%) based on CAG results. There was no statistically significant difference in the patients’ medical history, reference vascular area (no-flow vs. normal-flow; 15.5 ± 3.2 vs. 16.2 ± 3.3, p> 0.05) and lesion length (21.9 ± 5.1 vs. 19.5 ± 4.8, p> 0.05) between the two groups. No-reflow patients had a longer symptom onset to reperfusion time compared to normal blood-flow group [(6.6 ± 3.1) h vs (4.3 ± 2.7) h; p< 0.05] and higher incidence of TIMI flow grade< 3 (71.4% vs 49.0%, p< 0.05). By IVUS examination, the no-reflow group had a significantly increased coronary plaque area and plaque volume compared to normal blood-flow group [(13.7 ± 3.0) mm2 vs (10.2 ± 2.9) mm2; (285.4 ± 99.8) mm3 vs (189.7 ± 86.4) mm3; p< 0.01]. The presence of IVUS-detected soft plaque (57.1% vs. 24.0%, p< 0.01), eccentric plaque (64.2% vs. 33.7%, p< 0.05), plaque rupture (50.0% vs. 21.2%, p< 0.01), and thrombosis (42.8% vs. 15.3%) were significantly more common in no-reflow group. Conclusion There was no obvious relationship between the coronary risk factors and no-reflow phenomenon. The symptom onset to reperfusion time, TIMI flow grade before

  15. Elimination of the twist distortion in IVUS and CAG image fusion based on the Frenet-Serret formulas

    NASA Astrophysics Data System (ADS)

    Li, Hongxiao; Zhang, Zhaoxia; Chen, Xiaodong; Yu, Daoyin

    2010-11-01

    Cardiovascular disease can be diagnosed at higher accuracy by the fusion of IVUS (Intravascular Ultrasound) and CAG (Coronary Angiography) data. In the IVUS images acquisition process, pull-back path of the ultrasonic probe will twist due to intravascular blood flow and friction with vascular wall, which causes image distortion in the fusion of such IVUS images. In this paper, a new method used for reducing the twist between adjacent frames of IVUS is presented. First, we establish a rough perspective projection imaging model from the crossing information of two almost perpendicular projective angiography images. Then we use a discrete approximation of the Frenet-Serret formulas to calculate IVUS frames' relative twist by sequential triangulation method and correct the twist. Finally, coronary lumen data extracted from the corrected IVUS images are added to 3D transducer paths which are reconstructed by the model mentioned above. Reconstruction of the coronary artery which contains the lumen information of IVUS removes blind spots in CAG and provides a full view of artery which is absent in IVUS images.

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

    PubMed

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

    2015-04-01

    This study sought to compare angiographic endpoints at one-year follow-up after a drug-eluting stent implantation guided by either intravascular ultrasound (IVUS) or angiography in patients with chronic total occlusion (CTO) lesions. Patients with at least one CTO lesion recanalised successfully were randomly assigned to the IVUS-guided or the angiography-guided group. The use of IVUS for penetration of the true lumen and optimisation of stent expansion was only done in the IVUS-guided group. The primary endpoint was in-stent late lumen loss (LLL) at one-year follow-up. A total of 230 patients with CTO lesions after successful recanalisation were enrolled and followed with office visits or telephone contact up to 24 months. In-stent LLL in the IVUS-guided group was significantly lower compared to the angiography-guided group at one-year follow-up (0.28±0.48 mm vs. 0.46±0.68 mm, p=0.025), with a significant difference in restenosis of the "in-true-lumen" stent between the two groups (3.9% vs.13.7%, p=0.021). The minimal lumen diameter and minimal stent cross-section area significantly and negatively correlated with LLL (all p<0.001). The rates of adverse clinical events were comparable between the IVUS- and angiography-guided groups at two-year follow-up (21.7% vs. 25.2%, p=0.641). The IVUS-guided stenting of the CTO lesion was associated with less LLL and a lower incidence of "in-true-lumen" stent restenosis. Additional study is required to identify the clinical benefit of the IVUS-guided procedure for CTO lesions. [ChiCTR-TRC-10000996].

  17. The bull's eye sign and other suprainguinal venographic findings to limit the use of intravascular ultrasound in patients with severe venous stasis.

    PubMed

    Ascher, Enrico; Eisenberg, Justin; Bauer, Natalie; Marks, Natalie; Hingorani, Anil; Rizvi, Syed

    2017-01-01

    When assessing the common femoral and suprainguinal veins in patients with venous stasis, it is generally agreed that use of intravascular ultrasound (IVUS) is mandatory. This widely held dogma is reinforced by the fact that extrinsic compression of the iliac veins does not reproduce images consistent with eccentric stenosis as one sees in the arterial system. In an attempt to identify a subgroup of patients where the use of IVUS could be averted, we analyzed and carefully evaluated the images of patients who had both standard contrast venograms and IVUS examinations. Ninety-two common femoral and suprainguinal venograms performed during a recent 6-month period were randomly selected for analysis. Good quality venographic images were found in 88 of these limbs (78 patients) that also had IVUS data formed the basis of this analysis. All venograms included visualization of the common femoral, external and common iliac veins, and inferior vena cava. These veins were classified as (1) normal to mild (type I) vein narrowing or dilatation of ≤20% compared with the adjacent segment, (2) moderate (type II) ≥21%-40%, (3) severe (type III) ≥41%, and (4) bull's eye sign (type IV). The latter was defined as a central circle with minimal or no dye within a dilated vein and forking of the dye around the circle. In the present series, no 1-month mortality or 1-month morbidity was observed in these patients. The Clinical, Etiologic, Anatomic, and Pathologic (CEAP) classification score was class II in 24 cases (26%), class III in 36 cases (39%), class IV in 17 cases (18%), class V in nine cases (10%), and class VI in six cases (7%). There was no venographic or IVUS evidence of inferior vena cava stenosis or dilatation in this series. Of the venograms studied, 88 had positive intravascular ultrasound (PIVUS) or positive predictive value findings. The correlation of venographic findings and PIVUS was as follows: type I cases (26) had 85% PIVUS; type II (22) had 100% PIVUS; type

  18. 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.

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

    PubMed

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

    2004-01-01

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

  20. Clinical Impact of Intravascular Ultrasound-Guided Chronic Total Occlusion Intervention With Zotarolimus-Eluting Versus Biolimus-Eluting Stent Implantation: Randomized Study.

    PubMed

    Kim, Byeong-Keuk; Shin, Dong-Ho; Hong, Myeong-Ki; Park, Hun Sik; Rha, Seung-Woon; Mintz, Gary S; Kim, Jung-Sun; Kim, Je Sang; Lee, Seung-Jin; Kim, Hee-Yeol; Hong, Bum-Kee; Kang, Woong-Chol; Choi, Jin-Ho; Jang, Yangsoo

    2015-07-01

    There have been no randomized studies comparing intravascular ultrasound (IVUS)-guided versus conventional angiography-guided chronic total occlusion (CTO) intervention using new-generation drug-eluting stent Therefore, we conducted a prospective, randomized, multicenter trial designed to test the hypothesis that IVUS-guided CTO intervention is superior to angiography-guided intervention. After successful guidewire crossing, 402 patients with CTOs were randomized to the IVUS-guided group (n=201) or the angiography-guided group (n=201) and secondarily randomized to Resolute zotarolimus-eluting stents or Nobori biolimus-eluting stents. The primary and secondary end points were cardiac death and a major adverse cardiac event defined as the composite of cardiac death, myocardial infarction, or target-vessel revascularization, respectively. After 12-month follow-up, the rate of cardiac death was not significantly different between the IVUS-guided group (0%) and the angiography-guided group (1.0%; P by log-rank test=0.16). However, major adverse cardiac event rates were significantly lower in the IVUS-guided group than that in the angiography-guided group (2.6% versus 7.1%; P=0.035; hazard ratio, 0.35; 95% confidence interval, 0.13-0.97). Occurrence of the composite of cardiac death or myocardial infarction was significantly lower in the IVUS-guided group (0%) than in the angiography-guided group (2.0%; P=0.045). The rates of target-vessel revascularization were not significantly different between the 2 groups. In the comparison between Resolute zotarolimus-eluting stent and Nobori biolimus-eluting stent, major adverse cardiac event rates were not significantly different (4.0% versus 5.7%; P=0.45). Although IVUS-guided CTO intervention did not significantly reduce cardiac mortality, this randomized study demonstrated that IVUS-guided CTO intervention might improve 12-month major adverse cardiac event rate after new-generation drug-eluting stent implantation when compared

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

    PubMed

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

    2017-01-17

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

  2. Evaluation of a framework for the co-registration of intravascular ultrasound and optical coherence tomography coronary artery pullbacks.

    PubMed

    Molony, David S; Timmins, Lucas H; Rasoul-Arzrumly, Emad; Samady, Habib; Giddens, Don P

    2016-12-08

    A growing number of studies have used a combination of intravascular ultrasound (IVUS) and optical coherence tomography (OCT) for the assessment of atherosclerotic plaques. Given their respective strengths these imaging modalities highly complement each other. Correlations of hemodynamics and coronary artery disease (CAD) have been extensively investigated with both modalities separately, though not concurrently due to challenges in image registration. Manual co-registration of these modalities is a time expensive task subject to human error, and the development of an automatic method has not been previously addressed. We developed a framework that uses dynamic time warping for the longitudinal co-registration and dynamic programming for the circumferential co-registration of images and evaluated the methodology in a cohort (n = 12) of patients with moderate CAD. Excellent correlation was seen between the algorithm and two expert readers for longitudinal co-registration (CCC = 0.9964, CCC = 0.9959) and circumferential co-registration (CCC = 0.9688, CCC = 0.9598). The mean error of the circumferential co-registration angle was found to be within 10%. A framework for the co-registration of IVUS and OCT pullbacks has been developed which provides a foundation for comprehensive studies of CAD biomechanics.

  3. [Development of software for three-dimensional reconstruction and automatic quantification of intravascular ultrasound images. Initial experience].

    PubMed

    Sanz, Roberto; Bodí, Vicente; Sanchís, Juan; Moratal, David; Núñez, Julio; Palau, Patricia; García, Diego; Rieta, José J; Sanchís, Juan M; Chorro, Francisco J; Llácer, Angel

    2006-09-01

    Quantification of intravascular ultrasound (IVUS) images is essential in ischemic heart disease and interventional cardiology. Manual analysis is very slow and expensive. We describe an automated computerized method of analysis that requires only minimal initial input from a specialist. This study was carried out by interventional cardiologists and biomedical engineers working in close collaboration. We developed software in which it was necessary only to identify the media-adventitia boundary in a few images taken from the whole sequence. A three-dimensional reconstruction was then generated from each sequence, from which measurements of areas and volumes could be derived automatically. In total, 2300 randomly selected images from video sequences of 11 patients were analyzed. Results obtained using the proposed method differed only minimally from those obtained with the manual method: for vessel area measurements, the variability was 0.08 (0.07) (mean absolute error [standard deviation] normalized to the actual value; this corresponds to an error of 0.08 mm(2) per mm(2) of vessel area); for lumen area, 0.11 (0.11) (normalized), and for plaque volume, 0.5 (0.3) (normalized). Regions with severe lesions (<4 mm(2)) were correctly identified in more than 90% of cases. Specialist time needed for each reconstruction was 10 (8) minutes (vs 60 [10] minutes for manual analysis; P< .0001). The computerized method used dramatically reduced the time and effort needed for IVUS sequence analysis, and the automated measurements obtained were very promising.

  4. Comparison of coronary artery lesion length by NIRS-IVUS versus angiography alone.

    PubMed

    Hanson, Ivan D; Goldstein, James A; Dixon, Simon R; Stone, Gregg W

    2015-09-01

    Intravascular ultrasound (IVUS) studies analyzing target lesion plaque burden (PB) have established that invasive coronary angiography commonly underestimates lesion length, predisposing to 'geographic miss' during a percutaneous coronary intervention, which has been associated with adverse outcomes. Plaque composition may also influence stent outcome. The present study used near-infrared spectroscopy and IVUS (NIRS-IVUS) to assess the prevalence of PB and lipid-core plaque (LCP) extending beyond angiographic borders of target lesions. Fifty-eight patients (58 lesions) undergoing NIRS-IVUS were identified. By invasive coronary angiography, target lesion length and minimum lumen diameter were measured. Plaque, defined as NIRS-IVUS atheroma (either PB>40% or LCP), was identified adjacent to the angiographic-defined lesion margins. By NIRS-IVUS, atheroma (either PB>40% or LCP) was identified beyond angiographic lesion margins in 52/58 (90%) lesions. The mean lesion length was 13.4±5.9 mm by angiography and 19.8±7.0 mm (P<0.0001) by NIRS-IVUS. LCP extending beyond the angiographic border was observed in 30/58 (52%) lesions. NIRS-IVUS imaging shows that target lesion length is commonly underestimated by angiography alone. This finding may have implications for stent length selection and avoidance of geographic miss.

  5. Experience With Intravascular Ultrasound Imaging Of Human Atherosclerotic Arteries

    NASA Astrophysics Data System (ADS)

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

    1989-08-01

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

  6. 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.

  7. 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

  8. Coronary artery calcification is inversely related to body morphology in patients with significant coronary artery disease: a three-dimensional intravascular ultrasound study.

    PubMed

    Dangas, George D; Maehara, Akiko; Evrard, Solene M; Sartori, Samantha; Li, Jennifer R; Chirumamilla, Amala P; Nomura-Kitabayashi, Aya; Gukathasan, Nilusha; Hassanin, Ahmed; Baber, Usman; Fahy, Martin; Fuster, Valentin; Mintz, Gary S; Kovacic, Jason C

    2014-02-01

    Emerging data have indicated unexpected complexity in the regulation of vascular and bone calcification. In particular, several recent studies have challenged the concept of a universally positive relationship between body morphology [weight, height, body mass index (BMI), body surface area (BSA)] and the extent of vascular calcification. We sought to clarify these discrepancies and investigated the relationship between index lesion coronary artery calcification (CAC) and body morphology in patients undergoing percutaneous coronary intervention (PCI) using three-dimensional intravascular ultrasound (IVUS). We analysed CAC in patients who underwent PCI with pre-intervention IVUS imaging. The main outcome measure was the calcium index (CalcIndex); a three-dimensional IVUS-derived measure of total calcification per obstructive coronary lesion. A total of 346 patients (65.3 ± 10.6 years; 29.5% females) underwent PCI with IVUS-based CAC assessment. CalcIndex was categorized as zero-low (0-0.1399; n = 152) or intermediate-high (0.1400-1.2541; n = 194). All measures of body morphology were lower in patients with intermediate-high CalcIndex (height, P = 0.024; weight, P = 0.008; BMI, P = 0.064; BSA, P = 0.005). In adjusted multivariable models, weight and BSA were independent inverse predictors of intermediate-high CalcIndex [weight: odds ratio (OR) 0.986, P = 0.017; BSA: OR 0.323, P = 0.012] while CalcIndex also trended towards an inverse association with both height (P = 0.068) and BMI (P = 0.064). These independent inverse associations were consistent across multiple clinical subgroups, including stratification by age, race, gender, diabetes, and renal impairment. Using three-dimensional IVUS to assess vascular calcification, these data confirm an independent, inverse relationship between body size and index lesion CAC in patients with obstructive coronary artery disease.

  9. 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

  10. Coronary artery calcification is inversely related to body morphology in patients with significant coronary artery disease: a three-dimensional intravascular ultrasound study

    PubMed Central

    Dangas, George D.; Maehara, Akiko; Evrard, Solene M.; Sartori, Samantha; Li, Jennifer R.; Chirumamilla, Amala P.; Nomura-Kitabayashi, Aya; Gukathasan, Nilusha; Hassanin, Ahmed; Baber, Usman; Fahy, Martin; Fuster, Valentin; Mintz, Gary S.; Kovacic, Jason C.

    2014-01-01

    Aims Emerging data have indicated unexpected complexity in the regulation of vascular and bone calcification. In particular, several recent studies have challenged the concept of a universally positive relationship between body morphology [weight, height, body mass index (BMI), body surface area (BSA)] and the extent of vascular calcification. We sought to clarify these discrepancies and investigated the relationship between index lesion coronary artery calcification (CAC) and body morphology in patients undergoing percutaneous coronary intervention (PCI) using three-dimensional intravascular ultrasound (IVUS). Methods and results We analysed CAC in patients who underwent PCI with pre-intervention IVUS imaging. The main outcome measure was the calcium index (CalcIndex); a three-dimensional IVUS-derived measure of total calcification per obstructive coronary lesion. A total of 346 patients (65.3 ± 10.6 years; 29.5% females) underwent PCI with IVUS-based CAC assessment. CalcIndex was categorized as zero–low (0–0.1399; n = 152) or intermediate–high (0.1400–1.2541; n = 194). All measures of body morphology were lower in patients with intermediate–high CalcIndex (height, P = 0.024; weight, P = 0.008; BMI, P = 0.064; BSA, P = 0.005). In adjusted multivariable models, weight and BSA were independent inverse predictors of intermediate–high CalcIndex [weight: odds ratio (OR) 0.986, P = 0.017; BSA: OR 0.323, P = 0.012] while CalcIndex also trended towards an inverse association with both height (P = 0.068) and BMI (P = 0.064). These independent inverse associations were consistent across multiple clinical subgroups, including stratification by age, race, gender, diabetes, and renal impairment. Conclusion Using three-dimensional IVUS to assess vascular calcification, these data confirm an independent, inverse relationship between body size and index lesion CAC in patients with obstructive coronary artery disease. PMID:23904334

  11. a Deformable Template Model with Feature Tracking for Automated Ivus Segmentation

    NASA Astrophysics Data System (ADS)

    Manandhar, Prakash; Hau Chen, Chi

    2010-02-01

    Intravascular Ultrasound (IVUS) can be used to create a 3D vascular profile of arteries for preventative prediction of Coronary Heart Disease (CHD). Segmentation of individual B-scan frames is a crucial step for creating profiles. Manual segmentation is too labor intensive to be of routine use. Automated segmentation algorithms are not yet accurate enough. We present a method of tracking features across frames of ultrasound data to increase automated segmentation accuracy using a deformable template model.

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

    PubMed

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

    2013-01-01

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

  13. Guided Interventions for Prostate Cancer Using 3D-Transurethral Ultrasound and MRI Fusion

    DTIC Science & Technology

    2015-10-01

    fabrication. An FDA approved radially- phased 64-element array intravascular ultrasound ( IVUS ) device (Visions, Volcano Therapeutics) 8.2 French...catheter and Volcano s5 imaging system were used for the TUUS imaging. The IVUS was electronically controlled to yield 2D images that were stitched to...the stability of the phantoms over time, acquiring IVUS catheters, access to the imaging tools (TUUS imaging machine, TRUS imaging machine and MRI

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

    PubMed

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

    2016-10-26

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

  15. Image analysis techniques for automated IVUS contour detection.

    PubMed

    Papadogiorgaki, Maria; Mezaris, Vasileios; Chatzizisis, Yiannis S; Giannoglou, George D; Kompatsiaris, Ioannis

    2008-09-01

    Intravascular ultrasound (IVUS) constitutes a valuable technique for the diagnosis of coronary atherosclerosis. The detection of lumen and media-adventitia borders in IVUS images represents a necessary step towards the reliable quantitative assessment of atherosclerosis. In this work, a fully automated technique for the detection of lumen and media-adventitia borders in IVUS images is presented. This comprises two different steps for contour initialization: one for each corresponding contour of interest and a procedure for the refinement of the detected contours. Intensity information, as well as the result of texture analysis, generated by means of a multilevel discrete wavelet frames decomposition, are used in two different techniques for contour initialization. For subsequently producing smooth contours, three techniques based on low-pass filtering and radial basis functions are introduced. The different combinations of the proposed methods are experimentally evaluated in large datasets of IVUS images derived from human coronary arteries. It is demonstrated that our proposed segmentation approaches can quickly and reliably perform automated segmentation of IVUS images.

  16. An artificial neural network method for lumen and media-adventitia border detection in IVUS.

    PubMed

    Su, Shengran; Hu, Zhenghui; Lin, Qiang; Hau, William Kongto; Gao, Zhifan; Zhang, Heye

    2016-11-17

    Intravascular ultrasound (IVUS) has been well recognized as one powerful imaging technique to evaluate the stenosis inside the coronary arteries. The detection of lumen border and media-adventitia (MA) border in IVUS images is the key procedure to determine the plaque burden inside the coronary arteries, but this detection could be burdensome to the doctor because of large volume of the IVUS images. In this paper, we use the artificial neural network (ANN) method as the feature learning algorithm for the detection of the lumen and MA borders in IVUS images. Two types of imaging information including spatial, neighboring features were used as the input data to the ANN method, and then the different vascular layers were distinguished accordingly through two sparse auto-encoders and one softmax classifier. Another ANN was used to optimize the result of the first network. In the end, the active contour model was applied to smooth the lumen and MA borders detected by the ANN method. The performance of our approach was compared with the manual drawing method performed by two IVUS experts on 461 IVUS images from four subjects. Results showed that our approach had a high correlation and good agreement with the manual drawing results. The detection error of the ANN method close to the error between two groups of manual drawing result. All these results indicated that our proposed approach could efficiently and accurately handle the detection of lumen and MA borders in the IVUS images.

  17. Analysis of missing mechanism in IVUS imaging clinical trials with missing covariates.

    PubMed

    Hu, Mingxiu; Zhou, Tianyue

    2011-03-01

    Intravascular ultrasound (IVUS) is a clinical imaging procedure used to assess drug effects on the progression of coronary atherosclerosis in clinical trials. It is an invasive medical procedure of measuring coronary artery atheroma (plaque) volume, and leads to high missing rates (often over 30%). This paper uses an IVUS Phase II clinical trial data to explore the missing mechanism of IVUS endpoint, the percent atheroma volume (PAV). We proposed a moving-window method to examine the relationship between continuous covariates such as lipid endpoint and the probability of missing IVUS values, which provides a general approach for missing mechanism exploration. The moving-window method is more intuitive and provides a fuller picture about the relationship. In the example, some covariates such as lipid measures also have high missing rates after 12 months because of compliance issues probably caused by fatigue of blood drawing. We found that if the method of last observation carried forward (LOCF) is used to impute the lipid endpoints, it leads to biologically unexplainable results. Using the multiple imputation approach for the missing covariates results in a more reasonable conclusion about the IVUS missing mechanism. Age, race, and baseline PAV are identified as key potential contributors to the probability of missing IVUS endpoint. This finding can be used to reduce missing values in future IVUS trials by setting up appropriate inclusion and exclusion criteria at the trial design stages.

  18. QCA, IVUS and OCT in interventional cardiology in 2011.

    PubMed

    Reiber, Johan H C; Tu, Shengxian; Tuinenburg, Joan C; Koning, Gerhard; Janssen, Johannes P; Dijkstra, Jouke

    2011-12-01

    Over the past 30 years, quantitative coronary arteriography (QCA) has been used extensively as an objective and reproducible tool in clinical research to assess changes in vessel dimensions as a result of interventions, but also as a tool to provide evidence to the interventionalist prior to and after an intervention and at follow-up when necessary. With the increasing complexities of bifurcation stenting, corresponding analytical tools for bifurcation analysis have been developed with extensive reporting schemes. Although intravascular ultrasound (IVUS) has been around for a long time as well, more recent radiofrequency analysis provides additional information about the vessel wall composition; likewise optical coherence tomography (OCT) provides detailed information about the positions of the stent struts and the quality of the stent placement. Combining the information from the X-ray lumenogram and the intravascular imaging devices is mentally a challenging task for the interventionalist. To support the registration of these intravascular images with the X-ray images, 3D QCA has been developed and registered with the IVUS or OCT images, so that at every position along the vessel of interest the luminal data and the vessel wall data by IVUS or the stent strut data by OCT can be combined. From the 3D QCA the selection of the optimal angiographic views can also be facilitated. It is the intention of this overview paper to provide an extensive description of the techniques that we have developed and validated over the past 30 years.

  19. Evaluation of Plaque Morphology by 64-Slice Coronary Computed Tomographic Angiography Compared to Intravascular Ultrasound in Nonocclusive Segments of Coronary Arteries.

    PubMed

    Kesarwani, Manoj; Nakanishi, Rine; Choi, Tae-Young; Shavelle, David M; Budoff, Matthew J

    2017-08-01

    Although intravascular ultrasound (IVUS) is the current gold standard for plaque characterization, noninvasive coronary computed tomographic angiography (CCTA) requires further evaluation. The ability to detect plaque morphology by CCTA remains unclear. The purpose of this study was to evaluate the diagnostic accuracy of CCTA for plaque detection and morphology. Thirty-one patients underwent cardiac catheterization with IVUS and CCTA. The presence of plaque was evaluated by both modalities in nonocclusive segments (<50% stenosis) of the left anterior descending artery, left circumflex artery, and right coronary artery. Plaque morphology was classified as (1) normal, (2) soft or fibrous, (3) fibrocalcific, or (4) calcific. Results by IVUS and CCTA were compared blindly on a segment-to-segment basis with subgroup analysis based on CCTA tube voltage. Among the 31 patients (mean age 56.2 ± 8.6 years, 27% female), 152 segments were analyzed. Of these segments, 42% were in the left anterior descending artery, 32% were in the left circumflex artery, and 26% were in the right coronary artery. Plaque morphology by IVUS identified 103 segments as fibrous (68%), 31 as fibrocalcific (20%), and 6 as calcific (4.0%); 12 segments were normal (8.0%). To evaluate for the presence of plaque, CCTA had an overall sensitivity and specificity of 99% and 75%, respectively. In patients who underwent CCTA with a tube voltage of 100 kV, both sensitivity and specificity were 100%. The sensitivity and specificity of CCTA to identify plaque as calcified (fibrocalcific or calcific) vs noncalcified (soft or fibrous) were 87% and 96%, respectively. Overall, the accuracy of CCTA to detect the presence of plaque was 97%; the accuracy to detect plaque calcification was 94%. CCTA offers excellent sensitivity and accuracy for plaque detection and morphology characterization in nonocclusive coronary segments. In addition, diagnostic accuracy is preserved with a reduced tube voltage protocol

  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. Realistic IVUS image generation in different intraluminal pressures.

    PubMed

    Cardoso, Fernando Mitsuyama; Moraes, Matheus Cardoso; Furuie, Sérgio Shiguemi

    2012-12-01

    Intravascular ultrasound (IVUS) phantoms are important to calibrate and evaluate many IVUS imaging processing tasks. However, phantom generation is never the primary focus of related works; hence, it cannot be well covered, and is usually based on more than one platform, which may not be accessible to investigators. Therefore, we present a framework for creating representative IVUS phantoms, for different intraluminal pressures, based on the finite element method and Field II. First, a coronary cross-section model is selected. Second, the coronary regions are identified to apply the properties. Third, the corresponding mesh is generated. Fourth, the intraluminal force is applied and the deformation computed. Finally, the speckle noise is incorporated. The framework was tested taking into account IVUS contrast, noise and strains. The outcomes are in line with related studies and expected values. Moreover, the framework toolbox is freely accessible and fully implemented in a single platform. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. Effects of sitagliptin on coronary atherosclerosis in patients with type 2 diabetes-A serial integrated backscatter-intravascular ultrasound study

    PubMed Central

    Nozue, Tsuyoshi; Fukui, Kazuki; Koyama, Yutaka; Fujii, Hiroyuki; Kunishima, Tomoyuki; Hikita, Hiroyuki; Hibi, Kiyoshi; Miyazawa, Akiyoshi; Michishita, Ichiro; Investigators, for the TRUST

    2016-01-01

    Dipeptidyl peptidase-4 (DPP-4) inhibitors have demonstrated anti-inflammatory and anti-atherogenic effects in an animal model. However, the clinical usefulness of DPP-4 inhibitors, particularly its effects on coronary atherosclerosis, has not been evaluated thus far. Therefore, in this study, we evaluated the effects of sitagliptin, a DPP-4 inhibitor, on coronary atherosclerosis using integrated backscatter (IB)-intravascular ultrasound (IVUS) in patients with type 2 diabetes. This trial was a prospective, open-labeled, randomized, multicenter study. Twenty-eight patients with type 2 diabetes who underwent elective percutaneous coronary intervention (PCI) were randomly assigned to either the sitagliptin group (group S) or the control group (group C). Non-PCI lesions were evaluated using IB-IVUS at the time of PCI and at the 48-week follow-up. The primary endpoint was the percentage change in plaque volume measured using grayscale IVUS, and the secondary endpoint was changes in plaque composition evaluated using IB-IVUS. Grayscale IVUS analysis demonstrated that plaque volume tended to decrease in both groups (group S: -1.7±8.5%; group C: -3.2±12.2%), but a between-group difference was not observed. A decrease in the lipid plaque volume (group S: from 200.1±116.2 to 179.8±121.0 mm3, P = 0.02; group C: from 298.3±363.0 to 256.6±386.1 mm3, P = 0.1) and an increase in the calcified plaque volume (group S: from 2.1±0.9 to 3.2±1.8 mm3, P = 0.06; group C: from 2.3±1.7 to 4.8±3.5 mm3, P = 0.04) was observed on IB-IVUS analysis. Univariate and multivariate regression analyses showed that the percentage change in serum non-high-density lipoprotein (HDL) cholesterol level was an independent and significant predictor of a reduction in lipid plaque volume (β = 0.445, P = 0.04). In conclusions, sitagliptin did not significantly reduce coronary plaque volume in patients with type 2 diabetes. However, a decrease in the lipid plaque volume was observed in the sitagliptin

  3. Accuracy of OCT, grayscale IVUS, and their combination for the diagnosis of coronary TCFA: an ex vivo validation study.

    PubMed

    Fujii, Kenichi; Hao, Hiroyuki; Shibuya, Masahiko; Imanaka, Takahiro; Fukunaga, Masashi; Miki, Kojiro; Tamaru, Hiroto; Sawada, Hisashi; Naito, Yoshiro; Ohyanagi, Mitsumasa; Hirota, Seiichi; Masuyama, Tohru

    2015-04-01

    This study sought to assess the accuracy of optical coherence tomography (OCT), gray-scale intravascular ultrasound (IVUS), and their combination for detecting thin-cap fibroatheromas (TCFA). The extent to which the imaging characteristics of OCT and IVUS correlate with histologically defined TCFA is unknown. IVUS and OCT examinations identified focal plaques in 165 coronary arteries from 60 autopsy hearts. A total of 685 pairs of images of OCT and IVUS were compared with histology. By OCT, a TCFA was defined as a signal-poor region with diffuse borders and cap thickness <65 μm. By IVUS, a TCFA was defined by the presence of echolucent zones and/or ultrasound attenuation in areas of positive remodeling. By histology, 12 of 685 focal plaques were classified as TCFAs. With histology as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy for OCT-derived TCFA were 100%, 97%, 41%, 100%, and 98%, respectively. The corresponding numbers for IVUS-derived TCFA were 92%, 93%, 19%, 99%, and 93%, respectively. The histological findings underlying the false positive diagnoses of OCT for TCFA included large amounts of foam cell accumulation on the luminal surface, large amounts of microcalcifications at the surface, large amounts of hemosiderin accumulation, or organized thrombus. In contrast, histological causes of mischaracterization of TCFA by IVUS were mostly TCFA. When both OCT and IVUS criteria for TCFA were required to be met, the sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy were 92%, 99%, 69%, 99%, and 99%, respectively. In the present study, neither OCT nor IVUS were optimal to detect TCFA. The combined use of OCT and IVUS may improve TCFA detection accuracy. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. Use of intravascular imaging in managing coronary artery disease

    PubMed Central

    Jegere, Sanda; Narbute, Inga; Erglis, Andrejs

    2014-01-01

    For many years, coronary angiography has been considered “the gold standard” for evaluating patients with coronary artery disease. However, angiography only provides a planar two-dimensional silhouette of the lumen and is unsuitable for the precise assessment of atherosclerosis. With the introduction of intravascular imaging, direct visualization of the arterial wall is now feasible. Intravascular imaging modalities extend diagnostic information, thereby enabling more precise evaluation of plaque burden and vessel remodeling. Of all technologies, intravascular ultrasound (IVUS) is the most mature and widely used intravascular imaging technique. Optical coherence tomography (OCT) is an evolving technology that has the highest spatial resolution of existing imaging methods, and it is becoming increasingly widespread. These methods are useful tools for planning interventional strategies and optimizing stent deployment, particularly when stenting complex lesions. We strongly support the mandatory use of IVUS for left main percutaneous coronary intervention (PCI). In addition, it can be used to evaluate vascular responses, including neointimal growth and strut apposition, during follow-ups. Adequately powered randomized trials are needed to support IVUS or OCT use in routine clinical practice and to answer whether OCT is superior to IVUS in reducing adverse events when used to guide PCI. The current perception and adoption of innovative interventional devices, such as bioabsorbable scaffolds, will increase the need for intravascular imaging in the future. PMID:24976911

  5. Coronary β2-adrenoreceptors mediate endothelium-dependent vasoreactivity in humans: novel insights from an in vivo intravascular ultrasound study.

    PubMed

    Puri, Rishi; Liew, Gary Y H; Nicholls, Stephen J; Nelson, Adam J; Leong, Darryl P; Carbone, Angelo; Copus, Barbara; Wong, Dennis T L; Beltrame, John F; Worthley, Stephen G; Worthley, Matthew I

    2012-02-01

    The interaction between coronary β(2)-adrenoreceptors and segmental plaque burden is complex and poorly understood in humans. We aimed to validate intracoronary (IC) salbutamol as a novel endothelium-dependent vasodilator utilizing intravascular ultrasound (IVUS), and thus assess relationships between coronary β(2)-adrenoreceptors, regional plaque burden and segmental endothelial function. In 29 patients with near-normal coronary angiograms, IVUS-upon-Doppler Flowire imaging protocols were performed. Protocol 1: incremental IC salbutamol (0.15, 0.30, 0.60 μg/min) infusions (15 patients, 103 segments); protocol 2: salbutamol (0.30 μg/min) infusion before and after IC administration of N(G)-monomethyl-L-arginine (L-NMMA) (10 patients, 82 segments). Vehicle infusions (IC dextrose) were performed in 4 patients (21 segments). Macrovascular response [% change segmental lumen volume (ΔSLV)] and plaque burden [per cent atheroma volume (PAV)] were studied in 5-mm coronary segments. Microvascular response [per cent change in coronary blood flow (ΔCBF)] was calculated following each infusion. Intracoronary salbutamol demonstrated significant dose-response ΔSLV and ΔCBF from baseline, respectively (0.15 μg/min: 3.5 ± 1.3%, 28 ± 14%, P = 0.04, P = NS; 0.30 μg/min: 5.5 ± 1.4%, 54 ± 17%, P = 0.001, P < 0.0001; 0.60 μg/min: 4.8 ± 1.6%, 66 ± 15%, P = 0.02, P < 0.0001), with ΔSLV responses further exemplified in low vs. high plaque burden groups. Salbutamol vasomotor responses were suppressed by l-NMMA, supporting nitric oxide-dependent mechanisms. Vehicle infusions resulted in no significant ΔSLV or ΔCBF. Multivariate analysis including conventional cardiovascular risk factors, PAV, segmental remodelling and plaque eccentricity indices identified PAV as the only significant predictor of a ΔSLV to IC salbutamol (coefficient -0.18, 95% CI -0.32 to -0.044, P = 0.015). Conclusions Intracoronary salbutamol is a novel endothelium-dependent epicardial and

  6. Choosing the optimal mother wavelet for decomposition of radio-frequency intravascular ultrasound data for characterization of atherosclerotic plaque lesions

    NASA Astrophysics Data System (ADS)

    Bedekar, Devyani; Nair, Anuja; Vince, D. Geoffrey

    2005-04-01

    Aim: The objective of this work is to determine the optimal basis function to perform wavelet analysis for tissue characterization of radio frequency intravascular ultrasound (IVUS) backscattered data. This is the most important step in wavelet analysis as it ensures accurate decomposition of the original signal into the various frequency bands. The criterion to choose the mother wavelet that is best suited to the data depends on the intended application. Wavelet families possessing properties like orthogonality, regularity, stability and admissibility have previously been shown to have application in tissue characterization. Algorithm: Depending on the usable data bandwidth known from previous studies we decomposed data using a 4-level decomposition scheme. We then calculated Shannon"s entropy for every level and employed "minimum Shannon entropy criterion" to determine the best mother wavelet for signal decomposition. According to this criterion, accurate decomposition is indicated when the total entropy of the daughter (decomposed) levels is lower than the entropy of the parent level. Analysis and Results: We acquired 40 MHz IVUS data ex-vivo from 10 left anterior descending (LAD) coronary arteries. Data was acquired such that each frame comprised of 256 scanlines. Next, we randomly selected 3 scanlines for each LAD and applied the above-mentioned Shannon entropy criterion for these 30 scanlines. We analyzed 23 mother wavelets from different families. Daubechies 3rd order wavelet accurately decomposes 29/30 scanlines at all levels. Daubechies 6th order wavelet appears optimal for 21/30 scanlines. Future direction: To obtain more precise signal decomposition, the optimal mother wavelet should be selected at every decomposition level. The best mother wavelet is indicated by the lowest Shannon entropy for that particular level.

  7. Intravascular photoacoustic imaging of gold nanorod-labeled atherosclerotic plaques

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    Combined intravascular photoacoustic (IVPA) and intravascular ultrasound (IVUS) imaging has been previously established as a viable means for imaging atherosclerotic plaques using both endogenous and exogenous contrast. In this study, IVUS/IVPA imaging of an atherosclerotic rabbit aorta following injection of gold nanorods (AuNR) with peak absorbance within the tissue optical window was performed. Ex-vivo imaging results revealed high photoacoustic signal from localized AuNR. Corresponding histological cross-sections and digital photographs of the artery lumen confirmed the presence of AuNR preferentially located at atherosclerotic regions and in agreement with IVPA signal. Furthermore, an integrated IVUS/IVPA imaging catheter was used to image the AuNR in the presence of luminal blood. The results suggest that AuNR allow for IVPA imaging of exogenously labeled atherosclerotic plaques with a comparatively low background signal and without the need for arterial flushing.

  8. Intravascular photoacoustic imaging at 35 and 80 MHz

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Wei, Wei; Zhou, Qifa; Shung, K. Kirk; Chen, Zhongping

    2012-10-01

    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.

  9. Intravascular Ultrasound-Derived Stent Dimensions as Predictors of Angiographic Restenosis Following Nitinol Stent Implantation in the Superficial Femoral Artery.

    PubMed

    Miki, Kojiro; Fujii, Kenichi; Kawasaki, Daizo; Shibuya, Masahiko; Fukunaga, Masashi; Imanaka, Takahiro; Tamaru, Hiroto; Sumiyoshi, Akinori; Nishimura, Machiko; Horimatsu, Tetsuo; Saita, Ten; Okada, Kozo; Kimura, Takumi; Honda, Yasuhiro; Fitzgerald, Peter J; Masuyama, Tohru; Ishihara, Masaharu

    2016-06-01

    To identify intravascular ultrasound (IVUS) measurements that can predict angiographic in-stent restenosis (ISR) following nitinol stent implantation in superficial femoral artery (SFA) lesions. A retrospective review was conducted of 97 patients (mean age 72.9±8.9 years; 63 men) who underwent IVUS examination during endovascular treatment of 112 de novo SFA lesions between July 2012 and December 2014. Self-expanding bare stents were implanted in 46 lesions and paclitaxel-eluting stents in 39 lesions. Six months after stenting, follow-up angiography was conducted to assess stent patency. The primary endpoint was angiographic ISR determined by quantitative vascular angiography analysis at the 6-month follow-up. Variables associated with restenosis were sought in multivariate analysis; the results are presented as the odds ratio (OR) and 95% confidence interval (CI). At follow-up, 27 (31.8%) angiographic ISR lesions were recorded. The lesions treated with uncoated stents were more prevalent in the ISR group compared with the no restenosis group (74.1% vs 44.8%, p=0.02). Lesion length was longer (154.4±79.5 vs 109.0±89.3 mm, p=0.03) and postprocedure minimum stent area (MSA) measured by IVUS was smaller (13.9±2.8 vs 16.3±1.6 mm(2), p<0.001) in the ISR group. Multivariate analysis revealed that bare stent use (OR 7.11, 95% CI 1.70 to 29.80, p<0.01) and longer lesion length (OR 1.08, 95% CI 1.01 to 1.16, p=0.04) were predictors of ISR, while increasing postprocedure MSA (OR 0.58, 95% CI 0.41 to 0.82, p<0.01) was associated with lower risk of ISR. Receiver operating characteristic analysis identified a MSA of 15.5 mm(2) as the optimal cutpoint below which the incidence of restenosis increased (area under the curve 0.769). Postprocedure MSA can predict ISR in SFA lesions, which suggests that adequate stent enlargement during angioplasty might be required for superior patency. © The Author(s) 2016.

  10. Multimodality imaging of intermediate lesions: Data from FFR, OCT, NIRS-IVUS.

    PubMed

    Biały, Dariusz; Wawrzyńska, Magdalena; Arkowski, Jacek; Rogała, Marcin; Proniewska, Klaudia; Wańha, Wojciech; Wojakowski, Wojciech; Roleder, Tomasz

    2017-07-17

    Fractional flow reserve (FFR) assesses a functional impact of the atheroma on the myocardial ischemia, but it does not take into account the morphology of the lesion. Previous optical coherence tomography (OCT), intravascular ultrasound (IVUS) and near infrared spectroscopy (NIRS) studies presented their potential to detect vulnerable plaque, which is not possible by FFR assessment. With the following study, the intermediate lesions were assessed by FFR, OCT and combined NIRS-IVUS imaging to identify plaque vulnerability. 13 intermediate lesions were analyzed simultaneously by FFR, OCT and combined NIRS-IVUS imaging. Two lesions were found to have FFR ≤ 0.80 (0.65 and 0.76). The other 11 lesions had FFR > 0.80 with a mean FFR 0.88 ± 0.049. Two lesions with FFR ≤ 0.80 had plaque burden (PB) > 70% and minimal lumen area (MLA) < 4 mm², but neither of these 2 lesions were identified as OCT defined thin fibrous cap atheroma (TCFA), or NIRS-IVUS possible TCFA. Among the other 11 lesions with FFR > 0.80, 8 were identified as OCT-defined TCFA, 4 had PB > 70%, 6 had MLA < 4 mm², 2 had both plaque burden > 70% and MLA < 4 mm², 3 lesions were identified as NIRS-IVUS possible TCFA, and 4 lesions had LCBI > 400. The FFR-negative lesions pose traits of vulnerability as assessed simultaneously by IVUS, OCT and NIRS imaging.

  11. Reducing Neointima Formation in a Swine Model with IVUS and Sirolimus Microbubbles.

    PubMed

    Kilroy, Joseph P; Dhanaliwala, Ali H; Klibanov, Alexander L; Bowles, Douglas K; Wamhoff, Brian R; Hossack, John A

    2015-11-01

    Potent therapeutic compounds with dose dependent side effects require more efficient and selective drug delivery to reduce systemic drug doses. Here, we demonstrate a new platform that combines intravascular ultrasound (IVUS) and drug-loaded microbubbles to enhance and localize drug delivery, while enabling versatility of drug type and dosing. Localization and degree of delivery with IVUS and microbubbles was assessed using fluorophore-loaded microbubbles and different IVUS parameters in ex vivo swine arteries. Using a swine model of neointimal hyperplasia, reduction of neointima formation following balloon injury was evaluated when using the combination of IVUS and sirolimus-loaded microbubbles. IVUS and microbubble enhanced fluorophore delivery was greatest when applying low amplitude pulses in the ex vivo model. In the in vivo model, neointima formation was reduced by 50% after treatment with IVUS and the sirolimus-loaded microbubbles. This reduction was achieved with a sirolimus whole blood concentration comparable to a commercial drug-eluting stent (0.999 ng/mL). We anticipate this therapy will find clinical use localizing drug delivery for numerous other diseases in addition to serving as an adjunct to stents in treating atherosclerosis.

  12. 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). Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Intravascular Ultrasound Imaging of Peripheral Arteries as an Adjunct to Balloon Angioplasty and Atherectomy

    SciTech Connect

    Korogi, Yukunori; Hirai, Toshinori; Takahashi, Mutsumasa

    1996-11-15

    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 crossectional 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.

  14. Comparison of image characteristics of plaques in culprit coronary arteries by 64 slice CT and intravascular ultrasound in acute coronary syndromes.

    PubMed

    Takaoka, Hiroyuki; Ishibashi, Iwao; Uehara, Masae; Rubin, Geoffrey D; Komuro, Issei; Funabashi, Nobusada

    2012-10-04

    To evaluate plaque image characteristics in coronary artery culprit-lesions in subjects with acute coronary syndromes (ACS), we retrospectively compared coronary arterial images by 64-slice CT before conventional-coronary-angiogram with those by intravascular ultrasound (IVUS). Retrospective analysis of coronary arterial images from thirty-one subjects (26-males, mean age 59.3 ± 12.0 years) exhibiting acute symptoms with suspicion of ACS, where either (1) ECG was un-interpretable or (2) ECG was non diagnostic/cardiac biomarkers was equivocal; with significant stenosis on emergent 64 slice CT and subjects were finally diagnosed as having ACS confirmed by conventional-coronary-angiogram, followed by IVUS before coronary-intervention. After principal culprit-lesion components were classified into 1) thrombus, 2) soft plaques, and 3) fibrotic plaques by IVUS, corresponding culprit-lesion CT values were measured (two-observers). Nineteen and 12 of 31 subjects were finally diagnosed as unstable angina pectoris and non-ST elevation acute myocardial infarction respectively. Main culprit-lesion components of ACS were identified on MSCT in all subjects. Culprit-lesion CT values diagnosed as soft plaques by IVUS (n=6, 32.9 ± 8.7 HU) were not lower than those of thrombi (n=18, 43.2 ± 10.7 HU, p=0.268); both values were significantly lower than those of fibrotic plaques (n=7, 82.5 ± 22.6 HU) (both p<0.01). Calcification, spotty calcification, and positive arterial remodeling were observed in 67.7%, 61.3%, 58.1% (IVUS) and 58.1%, 51.6%, 74.2% (MSCT), respectively (all p=NS). CT value reproducibilities and culprit-lesion areas, were 0.87 and 0.86, respectively (two analyzers). 64-slice CT can non-invasively evaluate image characteristics in coronary artery culprit-lesions in ACS subjects accurately; this may help to differentiate soft plaques or thrombi generated by plaque rupture from fibrotic plaques. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. 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

  16. 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

  17. 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.

  18. Impact of deep vessel wall injury and vessel stretching on subsequent arterial remodeling after balloon angioplasty: a serial intravascular ultrasound study.

    PubMed

    Okura, Hiroyuki; Shimodozono, Shinichi; Hayase, Motoya; Bonneau, Heidi N; Yock, Paul G; Fitzgerald, Peter J

    2002-08-01

    Arterial remodeling has been shown to be responsible for lumen narrowing after nonstent interventions. To examine the impact of deep vessel wall injury (DI) after balloon angioplasty on the subsequent vessel remodeling process, we performed serial intravascular ultrasound (IVUS) analysis in 47 native coronary artery lesions that underwent balloon angioplasty. An IVUS study was performed before and after balloon angioplasty and repeated at follow-up. Vessel and lumen area were measured at the narrowest site before intervention. Plaque area was calculated as vessel area minus lumen area. DI was defined as the presence of plaque/vessel wall fracture deep in the medial layer (sonolucent zone by IVUS) after angioplasty. After angioplasty, DI was present in 18 (38%, DI group) and absent in 29 (62%, non-DI group) of lesions. During follow-up, changes in vessel area in the DI group were significantly larger than in the non-DI group (P =.007). There were no significant differences in changes in plaque area. A trend toward greater late lumen loss was observed in the non-DI group (P =.05). In the DI group, changes in lumen area correlated better with changes in vessel area (r = 0.81, P <.0001) than with changes in plaque area (r = 0.32, P =.20). However, in the non-DI group, changes in lumen area correlated with changes in plaque area (r = -0.55, P =.002), but not with changes in vessel area (r = 0.30, P =.11). Deep vessel wall injury after balloon angioplasty is associated with the magnitude of the subsequent vessel remodeling process. The differences in the remodeling process may have implications regarding adjunctive therapies to prevent restenosis after balloon angioplasty.

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

    PubMed Central

    2012-01-01

    Background The role of intravascular ultrasound (IVUS) in percutaneous coronary interventions (PCI) is still controversial despite several previously published meta-analyses. A meta-analysis to evaluate the controversial role of IVUS-guided PCI with bare-metal stenting was performed and a previous published meta-analysis was re-evaluated in order to clarify the discrepancy between results of these studies. Methods A systematic review was performed by an electronic search of the PubMed, Embase and Web of Knowledge databases and by a manual search of reference lists for randomized controlled trials published until April 2011, with clinical outcomes and, at least, six months of clinical follow-up. A meta-analysis based on the intention to treat was performed with the selected studies. Results Five studies and 1,754 patients were included. There were no differences in death (OR = 1.86; 95% CI = 0.88-3.95; p = 0.10), non-fatal myocardial infarction (OR = 0.65; 95% CI = 0.27-1.58; p = 0.35) and major adverse cardiac events (OR = 0.74; 95% CI = 0.49-1.13; p = 0.16). An analysis of the previous published meta-analysis strongly suggested the presence of publication bias. Conclusions There is no evidence to recommend routine IVUS-guided PCI with bare-metal stent implantation. This may be explained by the paucity and heterogeneity of the studies published so far. PMID:22999055

  20. The outcomes of intravascular ultrasound-guided drug-eluting stent implantation among patients with complex coronary lesions: a comprehensive meta-analysis of 15 clinical trials and 8,084 patients

    PubMed Central

    Fan, Zhong-Guo; Gao, Xiao-Fei; Li, Xiao-Bo; Shao, Ming-Xue; Gao, Ya-Li; Chen, Shao-Liang; Tian, Nai-Liang

    2017-01-01

    Objective: The effects of intravascular ultrasound (IVUS)-guided drug-eluting stent (DES) implantation in patients with complex coronary artery lesions remains to be controversial. This study sought to evaluate the outcomes of IVUS guidance in these patients. Methods: The EMBASE, Medline, and other internet sources were searched for relevant articles. The primary endpoint was major adverse cardiac events (MACE), including all-cause mortality, myocardial infarction (MI), and target-vessel revascularization (TVR). The incidence of definite/probable stent thrombosis (ST) was analyzed as the safety endpoint. Results: Fifteen clinical trials involving 8.084 patients were analyzed. MACE risk was significantly decreased following IVUS-guided DES implantation compared with coronary angiography (CAG) guidance (odds ratio [OR] 0.63, 95% confidence intervals [CI]: 0.53–0.73, p<0.001), which might mainly result from the lower all-cause mortality risk (OR 0.52, 95% CI: 0.40–0.67, p<0.001), MI (OR 0.70, 95% CI: 0.56–0.86, p=0.001), and TVR (OR 0.53, 95% CI: 0.40–0.70, p<0.001). The subgroup analyses indicated better outcomes of IVUS guidance in DES implantation for these patients with left main disease or bifurcation lesions. Conclusion: IVUS guidance in DES implantation is associated with a significant reduction in MACE risk in patients with complex lesions, particularly those with left main disease or bifurcation lesions. More large and powerful randomized trials are still warranted to guide stenting decision making. (Anatol J Cardiol 2017; 17: 258-68) PMID:28344214

  1. Defining a new standard for IVUS optimized drug eluting stent implantation: the PRAVIO study.

    PubMed

    Gerber, R T; Latib, A; Ielasi, A; Cosgrave, J; Qasim, A; Airoldi, F; Chieffo, A; Montorfano, M; Carlino, M; Michev, I; Tobis, J; Colombo, A

    2009-08-01

    Preliminary Investigation to the Angiographic Versus IVUS Optimization Trial is a single center prospective observational intravascular ultrasound (IVUS) guided stent implantation study assessing new criteria for optimal drug eluting stent (DES) deployment. IVUS assessment of DES often reveals underexpansion and malapposition. Optimal stent deployment is currently poorly defined and previous criteria may not be suitable in long and complex lesions. Optimization was defined as achieving >/or 70% of the cross-sectional area (CSA) of the postdilation balloon. This criterion was applied in 113 complex lesions. The size of this balloon was calculated according to vessel media-to-media diameters at various sites inside the stented segment. The IVUS guided treated lesions were matched according to diabetes, vessel type, reference vessel diameter, minimum lumen diameter (MLD), and lesion length with a group of angiographic treated lesions to compare final MLD achieved. Mean minimum stent CSA according to the postdilation balloon utilized was 4.62 mm(2), 6.26 mm(2), 7.87 mm(2), and 9.87 mm(2) for 2.5 mm, 3.0 mm, 3.5 mm, and 4 mm balloons, respectively. Final MLD (mm) was significantly larger in the IVUS compared to the angiographic-guided group (3.09 +/- 0.50 vs. 2.67 +/- 0.54; P < 0.0001). There were no procedural complications related to IVUS use. We propose new IVUS criteria based on vessel remodeling that results in an increment in the final MLD, compared to angiographic guidance, which is much larger than any previously published study. This criterion seems to be safely achievable. A proposed randomized study (angiographic vs. IVUS optimization trial) has been launched to test these concepts. (c) 2008 Wiley-Liss, Inc.

  2. Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology.

    PubMed

    Bourantas, Christos V; Jaffer, Farouc A; Gijsen, Frank J; van Soest, Gijs; Madden, Sean P; Courtney, Brian K; Fard, Ali M; Tenekecioglu, Erhan; Zeng, Yaping; van der Steen, Antonius F W; Emelianov, Stanislav; Muller, James; Stone, Peter H; Marcu, Laura; Tearney, Guillermo J; Serruys, Patrick W

    2016-04-26

    Cumulative evidence from histology-based studies demonstrate that the currently available intravascular imaging techniques have fundamental limitations that do not allow complete and detailed evaluation of plaque morphology and pathobiology, limiting the ability to accurately identify high-risk plaques. To overcome these drawbacks, new efforts are developing for data fusion methodologies and the design of hybrid, dual-probe catheters to enable accurate assessment of plaque characteristics, and reliable identification of high-risk lesions. Today several dual-probe catheters have been introduced including combined near infrared spectroscopy-intravascular ultrasound (NIRS-IVUS), that is already commercially available, IVUS-optical coherence tomography (OCT), the OCT-NIRS, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, IVUS intravascular photoacoustic imaging and combined fluorescence lifetime-IVUS imaging. These multimodal approaches appear able to overcome limitations of standalone imaging and provide comprehensive visualization of plaque composition and plaque biology. The aim of this review article is to summarize the advances in hybrid intravascular imaging, discuss the technical challenges that should be addressed in order to have a use in the clinical arena, and present the evidence from their first applications aiming to highlight their potential value in the study of atherosclerosis.

  3. 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.

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

    PubMed

    Van Mieghem, N M; de Jaegere, P P

    2013-08-01

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

  5. Image segmentation and tissue characterization in three-dimensional intravascular ultrasound images

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangmin; DeJong, Steven C.; McKay, Charles R.; Sonka, Milan

    1997-04-01

    In this paper, we report an automated approach to plaque tissue characterization in three-dimensional intravascular ultrasound images. Our previously reported automated method for coronary wall and plaque segmentation in intravascular ultrasound pullback sequences represent the first step of the method. Tissue characterization into two classes of soft and hard plaque is based on texture analysis and pattern recognition. Texture description features included gray- level-based measures, co-occurrence matrices, run length measures, and fractal-based measures. Performance of the method was assessed in cadaveric coronary arteries by comparison to the observer-defined plaque composition. Overall classification correctness of 90% was achieved.

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

    NASA Astrophysics Data System (ADS)

    Hsieh, Bao-Yu; Li, Pai-Chi

    2012-02-01

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

  7. Acoustic radiation force impulse imaging (ARFI) on an IVUS circular array.

    PubMed

    Patel, Vivek; Dahl, Jeremy J; Bradway, David P; Doherty, Joshua R; Lee, Seung Yun; Smith, Stephen W

    2014-04-01

    Our long-term goal is the detection and characterization of vulnerable plaque in the coronary arteries of the heart using intravascular ultrasound (IVUS) catheters. Vulnerable plaque, characterized by a thin fibrous cap and a soft, lipid-rich necrotic core is a precursor to heart attack and stroke. Early detection of such plaques may potentially alter the course of treatment of the patient to prevent ischemic events. We have previously described the characterization of carotid plaques using external linear arrays operating at 9 MHz. In addition, we previously modified circular array IVUS catheters by short-circuiting several neighboring elements to produce fixed beamwidths for intravascular hyperthermia applications. In this paper, we modified Volcano Visions 8.2 French, 9 MHz catheters and Volcano Platinum 3.5 French, 20 MHz catheters by short-circuiting portions of the array for acoustic radiation force impulse imaging (ARFI) applications. The catheters had an effective transmit aperture size of 2 mm and 1.5 mm, respectively. The catheters were connected to a Verasonics scanner and driven with pushing pulses of 180 V p-p to acquire ARFI data from a soft gel phantom with a Young's modulus of 2.9 kPa. The dynamic response of the tissue-mimicking material demonstrates a typical ARFI motion of 1 to 2 microns as the gel phantom displaces away and recovers back to its normal position. The hardware modifications applied to our IVUS catheters mimic potential beamforming modifications that could be implemented on IVUS scanners. Our results demonstrate that the generation of radiation force from IVUS catheters and the development of intravascular ARFI may be feasible.

  8. The Effect of Statin Therapy on Coronary Plaque Composition Using Virtual Histology Intravascular Ultrasound: A Meta-Analysis

    PubMed Central

    Zheng, Guian; Li, Yuxin; Huang, Huishan; Wang, Jinghan; Hirayama, Atsushi; Lin, Jinxiu

    2015-01-01

    Objective Previous studies have indicated that statin therapy may promote plaque regression. However, the impact of statin therapy on plaque composition has not been clearly elucidated. We performed a meta-analysis to investigate the effect of statin therapy on coronary plaque composition as assessed by virtual histology intravascular ultrasound (VH-IVUS). Methods Online databases were searched from inception to March 1, 2015. Studies providing VH-IVUS volumetric analyses of coronary plaque composition at baseline and follow-up in patients receiving statin therapy were included. Weighted mean difference (WMD) using a random-effects model was used. Results Ten studies involving 682 patients were included. There was a substantial reduction in fibrous volume between baseline and follow-up (WMD: -2.37 mm3, 95% confidence interval (CI) -4.01 to -0.74 mm3, P=0.004), and a significant increase in dense calcium (DC) volume (WMD: 0.89 mm3, 95% CI 0.70 to 1.08 mm3, P<0.00001). No significant change was seen in fibro-fatty and necrotic core (NC) volumes. In stratified analyses, the fibrous volume was decreased significantly (WMD: -3.39 mm3, 95% CI -6.56 to -0.21 mm3, P=0.04) and the absolute DC volume (WMD: 0.99 mm3, 95% CI 0.23 to 1.76 mm3, P=0.01) was increased in the subgroup with ≥12 months follow-up, whereas no significant change was observed in the subgroup with < 12 months follow-up. Similarly, a substantial decrease in fibrous volume (WMD: -2.01 mm3, 95% CI -3.05 to -0.96 mm3, P< 0.0002) and an increase in DC volume (WMD: 0.90 mm3, 95% CI 0.70 to 1.10 mm3, P< 0.00001) were observed in the subgroup with high-intensive statin therapy, while the change in fibrous and DC volumes approached statistical significance (P=0.05 and P=0.05, respectively) in the subgroup with low-intensive statin therapy. Conclusions Statin treatment, particularly of high-intensity and long-term duration, induced a marked modification in coronary plaque composition including a decrease in

  9. Induction Therapy With Antithymocyte Globulin in Patients Undergoing Cardiac Transplantation Is Associated With Decreased Coronary Plaque Progression as Assessed by Intravascular Ultrasound.

    PubMed

    Azarbal, Babak; Cheng, Richard; Vanichsarn, Christopher; Patel, Jignesh K; Czer, Lawrence S; Chang, David H; Kittleson, Michelle M; Kobashigawa, Jon A

    2016-01-01

    Antithymocyte globulin (ATG) is used as induction therapy after cardiac transplant for enhancing immunosuppression and delaying the initiation of nephrotoxic drugs. It is unknown if ATG induction is associated with decreased coronary plaque progression by intravascular ultrasound (IVUS). Patients transplanted between March 2010 and December 2012 with baseline and 1-year IVUS were included. All patients transplanted were included in a secondary analysis. Change in plaque progression was measured in a blinded fashion on matched coronary segments and contrasted between patients induced with ATG and those who were not. One hundred and three patients were included in IVUS arms. Mean age at transplant was 55.8 ± 12.6 years, and 33.0% were female. Patients induced with ATG were more sensitized (54.3% versus 14.3%). Plaque progression was attenuated in patients who received ATG by changes in maximal intimal area (1.0 ± 1.2 versus 2.3 ± 2.6 mm(2); P = 0.001), maximal percent stenosis (6.3 ± 7.9 versus 12.8 ± 12.3%; = 0.003), maximal intimal thickness (0.2 ± 0.2 versus 0.3 ± 0.3 mm; P = 0.035), and plaque volume (0.5 ± 0.7 versus 1.0 ± 1.3 mm(3)/mm; P = 0.016). Rapid plaque progression by maximal percent stenosis (≥ 20%) occurred less frequently in the ATG arm (4.3% versus 26.3; P = 0.003). Survival (P = 0.242) and any treated rejection (P = 0.166) were not statistically different between groups. Patients receiving ATG had a higher rate of first-year infection (P = 0.003), perhaps related to increased intravenous antibiotic use immediately postoperatively, and a trend toward more biopsy-proven rejection (P = 0.073). Induction therapy with ATG is associated with reduced first-year coronary plaque progression as assessed by IVUS, despite an increased prevalence of sensitized patients with a trend toward more rejection. © 2016 American Heart Association, Inc.

  10. Comparison of angiographic and IVUS derived coronary geometric reconstructions for evaluation of the association of hemodynamics with coronary artery disease progression.

    PubMed

    Timmins, Lucas H; Suo, Jin; Eshtehardi, Parham; Molony, David S; McDaniel, Michael C; Oshinski, John N; Giddens, Don P; Samady, Habib

    2016-09-01

    Wall shear stress (WSS) has been investigated as a prognostic marker for the prospective identification of rapidly progressing coronary artery disease (CAD) and atherosclerotic lesions likely to gain high-risk (vulnerable) characteristics. The goal of this study was to compare biplane angiographic vs. intravascular ultrasound (IVUS) derived reconstructed coronary geometries to evaluate agreement in geometry, computed WSS, and association of WSS and CAD progression. Baseline and 6-month follow-up angiographic and IVUS imaging data were collected in patients with non-obstructive CAD (n = 5). Three-dimensional (3D) reconstructions of the coronary arteries were generated with each technique, and patient-specific computational fluid dynamics models were constructed to compute baseline WSS values. Geometric comparisons were evaluated in arterial segments (n = 9), and hemodynamic data were evaluated in circumferential sections (n = 468). CAD progression was quantified from serial IVUS imaging data (n = 277), and included virtual-histology IVUS (VH-IVUS) derived changes in plaque composition. There was no significant difference in reconstructed coronary segment lengths and cross-sectional areas (CSA), however, IVUS derived geometries exhibited a significantly larger left main CSA than the angiographic reconstructions. Computed absolute time-averaged WSS (TAWSSABS) values were significantly greater in the IVUS derived geometries, however, evaluations of relative TAWSS (TAWSSREL) values revealed improved agreement and differences within defined zones of equivalence. Associations between VH-IVUS defined CAD progression and angiographic or IVUS derived WSS exhibited poor agreement when examining TAWSSABS data, but improved when evaluating the association with TAWSSREL data. We present data from a small cohort of patients highlighting strong agreement between angiographic and IVUS derived coronary geometries, however, limited agreement is observed between

  11. Quantitative multi-modality imaging analysis of a fully bioresorbable stent: a head-to-head comparison between QCA, IVUS and OCT.

    PubMed

    Gutiérrez-Chico, Juan Luis; Serruys, Patrick W; Girasis, Chrysafios; Garg, Scot; Onuma, Yoshinobu; Brugaletta, Salvatore; García-García, Héctor; van Es, Gerrit-Anne; Regar, Evelyn

    2012-03-01

    The bioresorbable vascular stent (BVS) is totally translucent and radiolucent, leading to challenges when using conventional invasive imaging modalities. Agreement between quantitative coronary angiography (QCA), intravascular ultrasound (IVUS) and optical coherence tomography (OCT) in the BVS is unknown. Forty five patients enrolled in the ABSORB cohort B1 study underwent coronary angiography, IVUS and OCT immediately post BVS implantation, and at 6 months. OCT estimated stent length accurately compared to nominal length (95% CI of the difference: -0.19; 0.37 and -0.15; 0.47 mm(2) for baseline and 6 months, respectively), whereas QCA incurred consistent underestimation of the same magnitude at both time points (Pearson correlation = 0.806). IVUS yielded low accuracy (95% CI of the difference: 0.77; 3.74 and -1.15; 3.27 mm(2) for baseline and 6 months, respectively), with several outliers and random variability test-retest. Minimal lumen area (MLA) decreased substantially between baseline and 6 months on QCA and OCT and only minimally on IVUS (95% CI: 0.11; 0.42). Agreement between the different imaging modalities is poor: worst agreement Videodensitometry-IVUS post-implantation (ICCa 0.289); best agreement IVUS-OCT at baseline (ICCa 0.767). All pairs deviated significantly from linearity (P < 0.01). Passing-Bablok non-parametric orthogonal regression showed constant and proportional bias between IVUS and OCT. OCT is the most accurate technique for measuring stent length, whilst QCA incurs systematic underestimation (foreshortening) and solid state IVUS incurs random error. Volumetric calculations using solid state IVUS are therefore not reliable. There is poor agreement for MLA estimation between all the imaging modalities studied, including IVUS-OCT, hence their values are not interchangeable.

  12. Multi-laboratory inter-institute reproducibility study of IVOCT and IVUS assessments using published consensus document definitions.

    PubMed

    Gerbaud, Edouard; Weisz, Giora; Tanaka, Atsushi; Kashiwagi, Manabu; Shimizu, Takehisa; Wang, Lin; Souza, Christiano; Bouma, Brett E; Suter, Melissa J; Shishkov, Milen; Ughi, Giovanni J; Halpern, Elkan F; Rosenberg, Mireille; Waxman, Sergio; Moses, Jeffrey W; Mintz, Gary S; Maehara, Akiko; Tearney, Guillermo J

    2016-07-01

    The aim of this study was to investigate the reproducibility of intravascular optical coherence tomography (IVOCT) assessments, including a comparison to intravascular ultrasound (IVUS). Intra-observer and inter-observer variabilities of IVOCT have been previously described, whereas inter-institute reliability in multiple laboratories has never been systematically studied. In 2 independent laboratories with intravascular imaging expertise, 100 randomized matched data sets of IVOCT and IVUS images were analysed by 4 independent observers according to published consensus document definitions. Intra-observer, inter-observer, and inter-institute variabilities of IVOCT qualitative and quantitative measurements vs. IVUS measurements were assessed. Minor inter- and intra-observer variability of both imaging techniques was observed for detailed qualitative and geometric analysis, except for inter-observer mixed plaque identification on IVUS (κ = 0.70) and for inter-observer fibrous cap thickness measurement reproducibility on IVOCT (ICC = 0.48). The magnitude of inter-institute measurement differences for IVOCT was statistically significantly less than that for IVUS concerning lumen cross-sectional area (CSA), maximum and minimum lumen diameters, stent CSA, and maximum and minimum stent diameters (P < 0.001, P < 0.001, P < 0.001, P = 0.02, P < 0.001, and P = 0.01, respectively). Minor inter-institute measurement variabilities using both techniques were also found for plaque identification. In the measurement of lumen CSA, maximum and minimum lumen diameters, stent CSA, and maximum and minimum stent diameters by analysts from two different laboratories, reproducibility of IVOCT was more consistent than that of IVUS. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  13. Multi-laboratory inter-institute reproducibility study of IVOCT and IVUS assessments using published consensus document definitions

    PubMed Central

    Gerbaud, Edouard; Weisz, Giora; Tanaka, Atsushi; Kashiwagi, Manabu; Shimizu, Takehisa; Wang, Lin; Souza, Christiano; Bouma, Brett E.; Suter, Melissa J.; Shishkov, Milen; Ughi, Giovanni J.; Halpern, Elkan F.; Rosenberg, Mireille; Waxman, Sergio; Moses, Jeffrey W.; Mintz, Gary S.; Maehara, Akiko; Tearney, Guillermo J.

    2016-01-01

    Aims The aim of this study was to investigate the reproducibility of intravascular optical coherence tomography (IVOCT) assessments, including a comparison to intravascular ultrasound (IVUS). Intra-observer and inter-observer variabilities of IVOCT have been previously described, whereas inter-institute reliability in multiple laboratories has never been systematically studied. Methods and results In 2 independent laboratories with intravascular imaging expertise, 100 randomized matched data sets of IVOCT and IVUS images were analysed by 4 independent observers according to published consensus document definitions. Intra-observer, inter-observer, and inter-institute variabilities of IVOCT qualitative and quantitative measurements vs. IVUS measurements were assessed. Minor inter- and intra-observer variability of both imaging techniques was observed for detailed qualitative and geometric analysis, except for inter-observer mixed plaque identification on IVUS (κ = 0.70) and for inter-observer fibrous cap thickness measurement reproducibility on IVOCT (ICC = 0.48). The magnitude of inter-institute measurement differences for IVOCT was statistically significantly less than that for IVUS concerning lumen cross-sectional area (CSA), maximum and minimum lumen diameters, stent CSA, and maximum and minimum stent diameters (P < 0.001, P < 0.001, P < 0.001, P = 0.02, P < 0.001, and P = 0.01, respectively). Minor inter-institute measurement variabilities using both techniques were also found for plaque identification. Conclusion In the measurement of lumen CSA, maximum and minimum lumen diameters, stent CSA, and maximum and minimum stent diameters by analysts from two different laboratories, reproducibility of IVOCT was more consistent than that of IVUS. PMID:26377904

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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.

  15. An automated method for lumen and media-adventitia border detection in a sequence of IVUS frames.

    PubMed

    Plissiti, Marina E; Fotiadis, Dimitrios I; Michalis, Lampros K; Bozios, George E

    2004-06-01

    In this paper, we present a method for the automated detection of lumen and media-adventitia border in sequential intravascular ultrasound (IVUS) frames. The method is based on the use of deformable models. 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. A simulated annealing scheme is included to ensure convergence at a global minimum. The method overcomes distortions in the expected image pattern, due to the presence of calcium, employing a specialized structure of the neural network and boundary correction schemas which are based on a priori knowledge about the vessel geometry. The proposed method is evaluated using sequences of IVUS frames from 18 arterial segments, some of them indicating calcified regions. The obtained results demonstrate that our method is statistically accurate, reproducible, and capable to identify the regions of interest in sequences of IVUS frames.

  16. Automated detection framework of the calcified plaque with acoustic shadowing in IVUS images.

    PubMed

    Gao, Zhifan; Guo, Wei; Liu, Xin; Huang, Wenhua; Zhang, Heye; Tan, Ning; Hau, William Kongto; Zhang, Yuan-Ting; Liu, Huafeng

    2014-01-01

    Intravascular Ultrasound (IVUS) is one ultrasonic imaging technology to acquire vascular cross-sectional images for the visualization of the inner vessel structure. This technique has been widely used for the diagnosis and treatment of coronary artery diseases. The detection of the calcified plaque with acoustic shadowing in IVUS images plays a vital role in the quantitative analysis of atheromatous plaques. The conventional method of the calcium detection is manual drawing by the doctors. However, it is very time-consuming, and with high inter-observer and intra-observer variability between different doctors. Therefore, the computer-aided detection of the calcified plaque is highly desired. In this paper, an automated method is proposed to detect the calcified plaque with acoustic shadowing in IVUS images by the Rayleigh mixture model, the Markov random field, the graph searching method and the prior knowledge about the calcified plaque. The performance of our method was evaluated over 996 in-vivo IVUS images acquired from eight patients, and the detected calcified plaques are compared with manually detected calcified plaques by one cardiology doctor. The experimental results are quantitatively analyzed separately by three evaluation methods, the test of the sensitivity and specificity, the linear regression and the Bland-Altman analysis. The first method is used to evaluate the ability to distinguish between IVUS images with and without the calcified plaque, and the latter two methods can respectively measure the correlation and the agreement between our results and manual drawing results for locating the calcified plaque in the IVUS image. High sensitivity (94.68%) and specificity (95.82%), good correlation and agreement (>96.82% results fall within the 95% confidence interval in the Student t-test) demonstrate the effectiveness of the proposed method in the detection of the calcified plaque with acoustic shadowing in IVUS images.

  17. Automated Detection Framework of the Calcified Plaque with Acoustic Shadowing in IVUS Images

    PubMed Central

    Liu, Xin; Huang, Wenhua; Zhang, Heye; Tan, Ning; Hau, William Kongto; Zhang, Yuan-Ting; Liu, Huafeng

    2014-01-01

    Intravascular Ultrasound (IVUS) is one ultrasonic imaging technology to acquire vascular cross-sectional images for the visualization of the inner vessel structure. This technique has been widely used for the diagnosis and treatment of coronary artery diseases. The detection of the calcified plaque with acoustic shadowing in IVUS images plays a vital role in the quantitative analysis of atheromatous plaques. The conventional method of the calcium detection is manual drawing by the doctors. However, it is very time-consuming, and with high inter-observer and intra-observer variability between different doctors. Therefore, the computer-aided detection of the calcified plaque is highly desired. In this paper, an automated method is proposed to detect the calcified plaque with acoustic shadowing in IVUS images by the Rayleigh mixture model, the Markov random field, the graph searching method and the prior knowledge about the calcified plaque. The performance of our method was evaluated over 996 in-vivo IVUS images acquired from eight patients, and the detected calcified plaques are compared with manually detected calcified plaques by one cardiology doctor. The experimental results are quantitatively analyzed separately by three evaluation methods, the test of the sensitivity and specificity, the linear regression and the Bland-Altman analysis. The first method is used to evaluate the ability to distinguish between IVUS images with and without the calcified plaque, and the latter two methods can respectively measure the correlation and the agreement between our results and manual drawing results for locating the calcified plaque in the IVUS image. High sensitivity (94.68%) and specificity (95.82%), good correlation and agreement (>96.82% results fall within the 95% confidence interval in the Student t-test) demonstrate the effectiveness of the proposed method in the detection of the calcified plaque with acoustic shadowing in IVUS images. PMID:25372784

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

    PubMed

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

    2013-04-01

    The double kissing (DK) crush technique is a modified version of the crush technique. It is specifically designed to increase the success rate of the final kissing balloon post-dilatation, but its efficacy and safety remain unclear. Data were obtained from the DKCRUSH-I trial, a prospective, randomized, multi-center study to evaluate safety and efficacy. Post-procedural and eight-month follow-up intravascular ultrasound (IVUS) analysis was available in 61 cases. Volumetric analysis using Simpson's method within the Taxus stent, and cross-sectional analysis at the five sites of the main vessel (MV) and three sites of the side branch (SB) were performed. Impact of the bifurcation angle on stent expansion at the carina was also evaluated. Stent expansion in the SB ostium was significantly less in the classical crush group ((53.81 ± 13.51)%) than in the DK crush group ((72.27 ± 11.46)%) (P = 0.04). For the MV, the incidence of incomplete crush was 41.9% in the DK group and 70.0% in the classical group (P = 0.03). The percentage of neointimal area at the ostium had a tendency to be smaller in the DK group compared with the classical group ((16.4 ± 19.2)% vs. (22.8 ± 27.1)%, P = 0.06). The optimal threshold of post-procedural minimum stent area (MSA) to predict follow-up minimum lumen area (MLA) < 4.0 mm(2) at the SB ostium was 4.55 mm(2), yielding an area under the curve of 0.80 (95% confidence interval: 0.61 to 0.92). Our data suggest that the DK crush technique is associated with improved quality of the final kissing balloon inflation (FKBI) and had smaller optimal cutoff value of post-procedural MSA at the SB ostium.

  19. 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.

  20. Fusion of 3D QCA and IVUS/OCT.

    PubMed

    Tu, Shengxian; Holm, Niels R; Koning, Gerhard; Huang, Zheng; Reiber, Johan H C

    2011-02-01

    The combination/fusion of quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS)/optical coherence tomography (OCT) depends to a great extend on the co-registration of X-ray angiography (XA) and IVUS/OCT. In this work a new and robust three-dimensional (3D) segmentation and registration approach is presented and validated. The approach starts with standard QCA of the vessel of interest in the two angiographic views (either biplane or two monoplane views). Next, the vessel of interest is reconstructed in 3D and registered with the corresponding IVUS/OCT pullback series by a distance mapping algorithm. The accuracy of the registration was retrospectively evaluated on 12 silicone phantoms with coronary stents implanted, and on 24 patients who underwent both coronary angiography and IVUS examinations of the left anterior descending artery. Stent borders or sidebranches were used as markers for the validation. While the most proximal marker was set as the baseline position for the distance mapping algorithm, the subsequent markers were used to evaluate the registration error. The correlation between the registration error and the distance from the evaluated marker to the baseline position was analyzed. The XA-IVUS registration error for the 12 phantoms was 0.03 ± 0.32 mm (P = 0.75). One OCT pullback series was excluded from the phantom study, since it did not cover the distal stent border. The XA-OCT registration error for the remaining 11 phantoms was 0.05 ± 0.25 mm (P = 0.49). For the in vivo validation, two patients were excluded due to insufficient image quality for the analysis. In total 78 sidebranches were identified from the remaining 22 patients and the registration error was evaluated on 56 markers. The registration error was 0.03 ± 0.45 mm (P = 0.67). The error was not correlated to the distance between the evaluated marker and the baseline position (P = 0.73). In conclusion, the new XA-IVUS/OCT co-registration approach is a

  1. Rigid and elastic registration for coronary artery IVUS images.

    PubMed

    Sun, Zheng; Bai, Hua; Liu, Bingru

    2016-04-29

    Intravascular ultrasound (IVUS) has been widely used in diagnosis and interventional treatment of cardiac vessel diseases. The coronary artery IVUS images are usually polluted by motion artifacts caused by cardiac motion, pulsatile blood and catheter twist during continuous pullback acquisition. Strategies for rigid and elastic registration of coronary artery IVUS studies are developed to suppress the longitudinal motion and misalignment between successive frames. Rigid registration is performed by searching for the optimal matching for each frame in other cycles based on the cyclic variation of gray-scale features. The image sequence is gated to properly identify the frames in each cardiac phase. Then, elastic registration between frames is achieved through an optimization algorithm based on thin plate spline (TPS) to correct the misalignment of successive slices. Experimental results with in vivo image data shows that the rigid registration performs better than the offline ECG gating. The elastic mapping relation between lumen contours in successive frames is smooth and continuous. The serrated vessel wall borders in longitudinal cuts are smoothed after rigid registration while image segmentation and feature extraction are required. The point-to-point correspondence between lumen contours detected from two matched frames is obtained with elastic registration.

  2. Does IVUS guidance of coronary interventions affect outcome? a prime example of the failure of randomized clinical trials.

    PubMed

    Gerber, Robert; Colombo, Antonio

    2008-04-01

    There has been a decline in the role of intravascular ultrasound (IVUS) guiding stenting. IVUS has lost favor with interventional cardiologists largely due to the emergence of drug eluting stents (DES). The advent of DES has lowered the need to maximize the final result due to the known low late-loss. This phenomenon has contributed to reduced interest in optimizing results with IVUS guidance. However, current concerns regarding stent thrombosis in relation to DES and its associated significant morbidity and mortality has once more focused attention on optimal stent deployment. Prior to DES, the evidence base was rather ambiguous, as some randomized and observational studies supported IVUS guided bare metal stent insertion in terms of reducing rates of restenosis and clinically driven target lesion revascularisation whereas others demonstrated no such benefit. As there is an additional cost and learning curve with IVUS, it has become difficult to justify its routine use. We present here a contemporary argument for the resurgence of IVUS optimized stent insertion. We also highlight deficiencies in previously adopted IVUS optimization criteria, which were based on distal and proximal lumen sizes. The new criteria proposed are based on vessel size at different segments of the stented area and therefore take advantage of vessel remodeling. The availability of high pressure, non-compliant balloons have made attainment of these new optimization targets possible without increasing the risk of complications. We hope to demonstrate this statement with the completion of the angiographically versus IVUS optimization (AVIO) study that soon will be initiated. Copyright 2008 Wiley-Liss, Inc.

  3. Combined IVUS and NIRS detection of fibroatheromas: histopathological validation in human coronary arteries.

    PubMed

    Kang, Soo-Jin; Mintz, Gary S; Pu, Jun; Sum, Stephen T; Madden, Sean P; Burke, Allen P; Xu, Ke; Goldstein, James A; Stone, Gregg W; Muller, James E; Virmani, Renu; Maehara, Akiko

    2015-02-01

    This study assessed grayscale intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) detection of a histological fibroatheroma (FA). NIRS-detected, lipid-rich plaques (LRPs) and IVUS-detected attenuated plaques are considered to be vulnerable. IVUS-attenuated plaque and NIRS-LRP (yellow or tan block chemogram) were compared with histopathology in 1,943 sections of 103 coronary arteries from 56 autopsied hearts. IVUS-superficial attenuation and NIRS-LRP showed a similar high specificity of approximately 95%, whereas IVUS-superficial attenuation alone had a poor sensitivity (vs. NIRS-LRP) in detecting FAs (36% vs. 47%; p = 0.001). Compared with FA sections with superficial attenuation, FA sections without superficial attenuation had a smaller plaque burden (57.1% vs. 67.7%), a larger arc of calcium (79.7° vs. 16.8°), and a lower prevalence of a ≥20% histological necrotic core (28% vs. 50%) or late FA (14% vs. 37%; all p < 0.05). Compared with FA sections with NIRS-LRP, FA sections without NIRS-LRP showed a smaller plaque burden (58.0% vs. 63.3%) and a lower prevalence of a ≥20% necrotic core (27% vs. 46%). Conversely, non-FAs with NIRS-LRP (vs. non-FAs without LRP) showed a larger plaque burden (55.1% vs. 46.3%), a greater prevalence of a ≥20% histological lipid pool (34% vs. 5%), and mostly pathological intimal thickening (50%) or fibrocalcific plaque (33%). When sections showed either IVUS attenuation or NIRS-LRP, the sensitivity for predicting a FA was significantly higher compared with IVUS attenuation alone (63% vs. 36%; p < 0.001) or NIRS-LRP alone (63% vs. 47%; p < 0.001). When sections showed both IVUS attenuation and NIRS-LRP, the positive predictive value improved compared with IVUS attenuation alone (84% vs. 66%; p < 0.001) or NIRS-LRP alone (84% vs. 65%; p < 0.001). NIRS-LRP was more accurate than IVUS for predicting plaque containing a necrotic core or a large lipid pool, and the combination was more accurate than either

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

    PubMed

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

    1996-01-01

    To characterize the effect of vessel curvature on the geometric accuracy of conventional three-dimensional reconstruction (3DR) algorithms for intravascular ultrasound image data. A common method of 3DR for intravascular ultrasound image data involves geometric reassembly and volumetric interpolation of a spatially related sequence of tomographic cross sections generated by an ultrasound catheter withdrawn at a constant rate through a vascular segment of interest. The resulting 3DR is displayed as a straight segment, with inherent vascular curvature neglected. Most vascular structures, however, are not straight but curved to some degree. For this reason, vascular curvature may influence the accuracy of computer-generated 3DR. We collected image data using three different intravascular ultrasound catheters (2.9 Fr, 4.3 Fr, 8.0 Fr) during a constant-rate pullback of 1 mm/sec through tubing of known diameter with imposed radii of curvature ranging from 2 to 10 cm. Image data were also collected from straight tubing. Image data were digitized at 1.0-mm intervals through a length of 25 mm. Two passes through each radius of curvature were performed with each intravascular ultrasound catheter. 3DR lumen volume for each radius of curvature was compared to that theoretically expected from a straight cylindrical segment. Differences between 3DR lumen volume of theoretical versus curved (actual) tubes were quantified as absolute percentage error and categorized as a function of curvature. Tubing deformation error was quantified by quantitative coronary angiography (QCA). Volumetric errors ranged from 1% to 35%, with an inverse relationship demonstrated between 3DR lumen volume and segmental radius of curvature. Higher curvatures (r < 6.0 cm) induced greater lumen volume error when compared to lower curvatures (r > 6.0 cm). This trend was exhibited for all three catheters and was shown to be independent of tubing deformation artifacts. QCA-determined percentage diameter

  5. Intravascular imaging comparison of two metallic limus-eluting stents abluminally coated with biodegradable polymers: IVUS and OCT results of the DESTINY trial.

    PubMed

    Costa, J Ribamar; Chamié, Daniel; Abizaid, Alexandre A C; Ribeiro, Expedito; Meireles, George C; Prudente, Maurício; Campos, Carlos A; Castro, Juliana P; Costa, Ricardo; Lemos, Pedro A

    2017-02-01

    We sought to compare, by means of IVUS and OCT imaging, the performance of a novel sirolimus-eluting drug-eluting stent (DES) with biodegradable polymer (Inspiron™) to the Biomatrix™ DES. From the DESTINY trial, a total of 70 randomized patients (2:1) were enrolled in the IVUS substudy (Inspiron™, n = 46; Biomatrix™: n = 20) while 25 patients were evaluated with OCT (Inspiron™, n = 19; Biomatrix™: n = 06) at 9-month follow-up. The main endpoints were % of neointimal tissue obstruction (IVUS) and neointimal stut coverage (OCT) at 9 months. Patients treated with both DES had very little NIH formation at 9 months either by IVUS (% of NIH obstruction of 4.9 ± 4.1 % with Inspiron™ vs. 2.7 ± 2.9 % with Biomatrix™, p = 0.03) or by OCT (neointimal thickness of 144.2 ± 72.5 µm Inspiron™ vs. 115.0 ± 53.9 µm with Biomatrix™, p = 0.45). Regarding OCT strut-level assessment, again both devices showed excellent 9-month performance, with high rates of strut coverage (99.49 ± 1.01 % with Inspiron™ vs. 97.62 ± 2.21 % with Biomatrix™, p < 0.001) and very rare malapposition (0.29 ± 1.06 % with Inspiron™ vs. 0.53 ± 0.82 % with Biomatrix™, p = 0.44). Patients with any uncovered struts were more frequently identified in the Biomatrix™ group (9.78 ± 7.13 vs. 2.29 ± 3.91 %, p < 0.001). In the present study, midterm IVUS and OCT evaluations showed that both new generation DES with biodegradable polymer were effective in terms of suppressing excessive neointimal response, with very high rates of apposed and covered struts, suggesting a consistent and benign healing pattern.

  6. Association of circulating levels of neopterin with non-culprit plaque vulnerability in CAD patients an angiogram, optical coherent tomography and intravascular ultrasound study.

    PubMed

    Sun, Yong; He, Jieqiong; Tian, Jinwei; Xie, Zulong; Wang, Chao; Yu, Bo

    2015-07-01

    Neopterin is a pteridine derivative secreted by activated macrophages. Previous studies have shown that neopterin plays a pivotal role in coronary artery disease (CAD); however, the relationship between circulating neopterin and non-culprit plaque vulnerability in patients with CAD remains unclear. In this study, we investigated the correlation of neopterin and vulnerable plaque features in patients with CAD. One hundred and thirty non-culprit plaques from 81 patients with CAD were assessed by angiogram and optical coherence tomography (OCT) as well as intravascular ultrasound (IVUS) imaging. According to the median value of serum neopterin (10.61 nmol/L), patients were divided into a low neopterin group (n = 40, IVUS findings showed that plaque burden was greater in the high neopterin group than that in the low neopterin group (P = 0.005). Neopterin was positively associated with vulnerable plaque features including TCFA, thinner fibrous cap, plaque rupture, greater plaque burden and frequent microvessel occurrence in CAD patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. IVUS catheter motion: implications for ultrasonic speckle and correction in IVUS palpography

    NASA Astrophysics Data System (ADS)

    Danilouchkine, Mikhail G.; Mastik, Frits; van der Steen, Antonius F. W.

    2008-03-01

    Intravascular Ultrasound (IVUS) palpography is a techniques that depicts the distribution of the mechanical strain over the luminal surface of coronary arteries. It utilizes conventional radiofrequency (RF) signals acquired at two different levels of a compressional load. The signals are cross-correlated to obtain the microscopic tissue displacements, which can be directly translated into local strain of the vessel wall. However, (apparent) tissue motion and nonuniform deformation of the vessel wall due to catheter jolting and rotation reduce signal correlation and result in void strain estimates. Implications of probe motion were studied on the tissue-mimicking phantom. The measured circumferential tissue displacement and level of the speckle decorrelation amounted to 12° and 0.58 for the catheter displacement of 800 μm, respectively. To compensate for the motion artifacts in IVUS palpography, a novel method, based on the feature-based scale-space Optical Flow (OF) was employed. The computed OF vector field quantifies the amount of the local tissue misalignment in consecutive frames. Subsequently, the extracted motion pattern is used to realign the signals prior to the cross-correlation analysis, reducing signal decorrelation and increasing the number of valid strain estimates. The advantage of applying the motion compensation algorithms was demonstrated in a mid-scale validation study on 14 in-vivo pullbacks. Both methods substantially increase the number of valid strain estimates in the partial and compounded palpograms. A mean relative improvement amounts to 28% and 14%, respectively. Implementation of motion compensation method increase the diagnostic value of IVUS palpography.

  8. Intravascular Targets for Molecular Contrast-Enhanced Ultrasound Imaging

    PubMed Central

    Moestue, Siver A.; Gribbestad, Ingrid S.; Hansen, Rune

    2012-01-01

    Molecular targeting of contrast agents for ultrasound imaging is emerging as a new medical imaging modality. It combines advances in ultrasound technology with principles of molecular imaging, thereby allowing non-invasive assessment of biological processes in vivo. Preclinical studies have shown that microbubbles, which provide contrast during ultrasound imaging, can be targeted to specific molecular markers. These microbubbles accumulate in tissue with target (over) expression, thereby significantly increasing the ultrasound signal. This concept offers safe and low-cost imaging with high spatial resolution and sensitivity. It is therefore considered to have great potential in cancer imaging, and early-phase clinical trials are ongoing. In this review, we summarize the current literature on targets that have been successfully imaged in preclinical models using molecularly targeted ultrasound contrast agents. Based on preclinical experience, we discuss the potential clinical utility of targeted microbubbles. PMID:22837657

  9. NIRS and IVUS for characterization of atherosclerosis in patients undergoing coronary angiography.

    PubMed

    Brugaletta, Salvatore; Garcia-Garcia, Hector M; Serruys, Patrick W; de Boer, Sanneke; Ligthart, Jurgen; Gomez-Lara, Josep; Witberg, Karen; Diletti, Roberto; Wykrzykowska, Joanna; van Geuns, Robert-Jan; Schultz, Carl; Regar, Evelyn; Duckers, Henricus J; van Mieghem, Nicolas; de Jaegere, Peter; Madden, Sean P; Muller, James E; van der Steen, Antonius F W; van der Giessen, Wim J; Boersma, Eric

    2011-06-01

    The aim of this study was to compare the findings of near-infrared spectroscopy (NIRS), intravascular ultrasound (IVUS) virtual histology (VH), and grayscale IVUS obtained in matched coronary vessel segments of patients undergoing coronary angiography. Intravascular ultrasound VH has been developed to add tissue characterization to the grayscale IVUS assessment of coronary plaques. Near-infrared spectroscopy is a new imaging technique able to identify lipid core-containing coronary plaques (LCP). We performed NIRS and IVUS-VH pullbacks in a consecutive series of 31 patients with a common region of interest (ROI) between 2 side branches. For each ROI, we analyzed the chemogram blocks by NIRS, plaque area and plaque burden by grayscale IVUS, and tissue types by IVUS-VH. The chemogram block is a summary metric of a 2-mm vertical slice of the chemogram. The value ranges from 0 to 1 according to the presence of lipids and represents the probability of LCP with a color scale from red (low probability) through orange and tan to yellow (high probability). Plaque area (mm(2)) increases as percentage VH derived-necrotic core (NC) content (4.6 ± 2.7 vs. 7.4 ± 3.5 vs. 8.6 ± 3.4 vs. 7.9 ± 3.3, grouped in percentage NC quartiles, p<0.001) and chemogram block probability color bin thresholds increase (4.9 ± 3.8 red, 7.3 ± 3.6 orange, 8.1 ± 3.4 tan, and 8.7 ± 3.4 yellow, p<0.001). The correlation between the block chemogram detection of lipid core and percentage NC content by VH was weak (r=0.149). Correction for the presence of calcium does not improve this correlation. Larger plaque area by grayscale IVUS was more often associated with either elevated percentage VH-NC or LCP by NIRS; however, the correlation between the detection of LCP by NIRS and necrotic core by VH is weak. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. 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.

  11. Feasibility of diagnosing unstable plaque in patients with acute coronary syndrome using iMap-IVUS*

    PubMed Central

    LIU, Jian; WANG, Zhao; WANG, Wei-min; LI, Qi; MA, Yu-liang; LIU, Chuan-fen; LU, Ming-yu; ZHAO, Hong

    2015-01-01

    Objective: To compare the plaque composition between stable and unstable plaques, characterize unstable plaque by using iMap-intravascular ultrasound (IVUS), and quantify the diagnostic criteria for unstable plaque. Methods: Thirty-three acute coronary syndrome (ACS) patients who had undergone coronary angiography and IVUS from February 19, 2014 to December 19, 2014 at Peking University People’s Hospital were enrolled in the study. Baseline data were collected. The patients were divided into two groups according to their gray-scale IVUS imaging, stable plaque and unstable plaque. A difference-in-difference evaluation was performed using the baseline data and off-line iMap imaging results between the two groups. A receiver operating characteristic (ROC) curve was constructed to obtain the optimal cut-off value to diagnose unstable plaque. Results: Percentages of fibrotic and necrotic tissues, absolute values of lipidic, necrotic, and calcified tissues, and plaque burden were independent predictors for unstable plaque. Absolute necrotic area was the best predictor and exhibited the highest diagnostic value for plaque vulnerability (area under the curve (AUC)=0.806, P=0.000, 95% CI (0.718, 0.894)). The cut-off score for predicting unstable plaque was 4.0 mm2. Conclusions: This study attempted to propose a cut-off value based on absolute necrotic area using iMap-IVUS to predict plaque vulnerability in patients with ACS. This score might provide a valuable reference for diagnosing unstable plaque. PMID:26537210

  12. An IVUS image-based approach for improvement of coronary plaque characterization.

    PubMed

    Taki, Arash; Roodaki, Alireza; Setarehdan, Seyed Kamaledin; Avansari, Sara; Unal, Gozde; Navab, Nassir

    2013-05-01

    Virtual Histology-Intravascular Ultrasound (VH-IVUS) is widely used for studying atherosclerosis plaque composition. However, one of the main limitations of the VH-IVUS relates to its dependence to the Electrocardiogram (ECG)-gated acquisition. To overcome this limitation, this paper proposes a robust image-based approach for characterization of the plaques using IVUS images. The proposed method consists of three main steps of (1) shadow detection: as an efficient preprocessing step to identify and remove acoustic shadow regions; (2) feature extraction: a combination of gray-scale based features and textural descriptors; and (3) classification: to classify each pixel into one of the three classes (calcium, necrotic core and fibro-fatty). In order to evaluate the efficiency of the proposed algorithm two in-vivo and ex-vivo data sets are considered. The kappa values of 0.639 on in-vivo and 0.628 on ex-vivo tests with VH-IVUS and the histology images labeled by the experts respectively indicate the effectiveness of the proposed algorithm. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Feasibility of diagnosing unstable plaque in patients with acute coronary syndrome using iMap-IVUS.

    PubMed

    Liu, Jian; Wang, Zhao; Wang, Wei-min; Li, Qi; Ma, Yu-liang; Liu, Chuan-fen; Lu, Ming-yu; Zhao, Hong

    2015-11-01

    To compare the plaque composition between stable and unstable plaques, characterize unstable plaque by using iMap-intravascular ultrasound (IVUS), and quantify the diagnostic criteria for unstable plaque. Thirty-three acute coronary syndrome (ACS) patients who had undergone coronary angiography and IVUS from February 19, 2014 to December 19, 2014 at Peking University People's Hospital were enrolled in the study. Baseline data were collected. The patients were divided into two groups according to their gray-scale IVUS imaging, stable plaque and unstable plaque. A difference-in-difference evaluation was performed using the baseline data and off-line iMap imaging results between the two groups. A receiver operating characteristic (ROC) curve was constructed to obtain the optimal cut-off value to diagnose unstable plaque. Percentages of fibrotic and necrotic tissues, absolute values of lipidic, necrotic, and calcified tissues, and plaque burden were independent predictors for unstable plaque. Absolute necrotic area was the best predictor and exhibited the highest diagnostic value for plaque vulnerability (area under the curve (AUC)=0.806, P=0.000, 95% CI (0.718, 0.894)). The cut-off score for predicting unstable plaque was 4.0 mm(2). This study attempted to propose a cut-off value based on absolute necrotic area using iMap-IVUS to predict plaque vulnerability in patients with ACS. This score might provide a valuable reference for diagnosing unstable plaque.

  14. 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.

  15. Reproducibility of grayscale and radiofrequency IVUS data acquisition in stented coronary arteries.

    PubMed

    Madssen, Erik; Jakala, Jacek; Proniewska, Klaudia; Kulaga, Tomasz; Hegbom, Knut; Wiseth, Rune

    2014-10-01

    Variability in data acquisition from intervened coronary arteries could represent a source of error that has implications for the design of serial stent studies. We assessed inter-pullback reproducibility of volumetric grayscale and radiofrequency intravascular ultrasound (IVUS) data in stented coronary arteries. Fifteen patients with coronary artery lesions treated with stent implantation were included and examined with two separate pullbacks using the Eagle Eye Gold-phased array 20 MHz IVUS catheter (Volcano). The arteries were divided into five segments, giving a total of 150 sub-segments for analyses. Matching of frames was performed using landmarks that were clearly visible in coronary angiography and intravascular pullbacks. Data were analyzed off-line at an independent Corelab. The inter-pullback reproducibility of geometrical data was very good for non-stented segments with relative differences less than 5% between pullbacks for lumen-, vessel-, and plaque volumes. For stented segments reproducibility was poorer with relative differences between pullbacks in the range of 5-10%. The inter-pullback reproducibility of compositional data demonstrated large standard deviations of relative differences, indicating a weaker agreement. Agreements between pullbacks were weaker in stented than those in non-stented segments. Based on our data, future longitudinal IVUS studies in intervened vessels should account for a variability of 5-10% attributed to the acquisition of images.

  16. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques.

    PubMed

    Falcão, João L A A; Falcão, Breno A A; Gurudevan, Swaminatha V; Campos, Carlos M; Silva, Expedito R; Kalil-Filho, Roberto; Rochitte, Carlos E; Shiozaki, Afonso A; Coelho-Filho, Otavio R; Lemos, Pedro A

    2015-01-27

    Background: The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. Objectives: We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. Methods: The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. Results: At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. Conclusions: In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.

  17. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

    PubMed Central

    Falcão, João L. A. A.; Falcão, Breno A. A.; Gurudevan, Swaminatha V.; Campos, Carlos M.; Silva, Expedito R.; Kalil-Filho, Roberto; Rochitte, Carlos E.; Shiozaki, Afonso A.; Coelho-Filho, Otavio R.; Lemos, Pedro A.

    2015-01-01

    Background The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. Objectives We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. Methods The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. Results At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. Conclusions In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques. PMID:25993595

  18. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques.

    PubMed

    Falcão, João L A A; Falcão, Breno A A; Gurudevan, Swaminatha V; Campos, Carlos M; Silva, Expedito R; Kalil-Filho, Roberto; Rochitte, Carlos E; Shiozaki, Afonso A; Coelho-Filho, Otavio R; Lemos, Pedro A

    2015-04-01

    The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.

  19. 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

  20. 80-MHz intravascular ultrasound transducer using PMN-PT free-standing film.

    PubMed

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

    2011-11-01

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

  1. 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.

  2. 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

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

    PubMed

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

    2011-12-01

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

  4. In-vivo iMap IVUS comparison of in-stent neointima and native coronary atherosclerosis.

    PubMed

    Trusinskis, Karlis; Strenge, Karlis; Juhnevica, Dace; Erglis, Andrejs

    2015-06-01

    The purpose of this study was to compare plaque characteristics of native coronary atherosclerosis and in-stent neointima ten months after ST elevation myocardial infarction (STEMI) using iMap intravascular ultrasound (IVUS). In 49 patients in-stent neointima and the coronary segment proximal to the stent were analyzed with iMap intravascular ultrasound (IVUS) ten months after primary PCI for STEMI. A higher percentage of necrotic tissue was observed in the proximal coronary segment compared to the in-stent neointima by iMap IVUS (25.5% ± 12.8% vs 12.3% ± 3.3%, p < 0.0001) ten months after STEMI. The proportion of fibrotic tissue in the proximal segment was lower (63.6% ± 14.8% vs 72.0% ± 5.7%, p = 0.002) and the proportion of the lipidic tissue was higher (8.8% ± 3.0% vs 5.9% ± 2.0%, p < 0.0001) than in-stent neointima. In patients ten months after STEMI, in-stent neointima contained a higher proportion of fibrotic tissue and lower proportion of necrotic and lipidic tissue compared the native atherosclerotic lesion. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Intravascular ultrasound assessment of the effect of laser energy on the arterial wall during the treatment of femoro-popliteal lesions: a CliRpath excimer laser system to enlarge lumen openings (CELLO) registry study.

    PubMed

    Kuku, Kayode O; Garcia-Garcia, Hector M; Koifman, Edward; Kajita, Alexandre H; Desale, Sameer; Azizi, Viana; Melaku, Gebremedhin; Bui, Anh; Meirovich, Yael F; Beyene, Solomon; Dheendsa, Aaphtaab; Schneider, Blaine; Waksman, Ron

    2017-09-26

    The CliRpath Excimer Laser System to Enlarge Lumen Openings (CELLO) registry included patients treated with modified excimer laser catheters for the endovascular treatment of peripheral artery disease affecting the superficial femoral artery (SFA) and proximal popliteal artery. The aim of this study was to assess, via intravascular ultrasound (IVUS) the dissections in the vessel wall following treatment with the laser catheters. IVUS grayscale images from the CELLO registry were systematically reviewed for dissections in the treated vessel segments by two investigators. Images from 33 patients; 66 pullbacks (1867 IVUS frames in 2 phases), were successfully matched frame-to-frame to evaluate identical segments of the treated vessels in the two phases; post-2 mm Turbo-Elite laser pilot channel creation and post Turbo-Booster laser atherectomy. Dissections were categorized as; (1) intimal, (2) medial, (3) intramural hematoma, and (4) adventitial according to the ACC Clinical Expert Consensus Document classification of dissections. An average of 57 frames was evaluated per pullback, giving a total of 3734 frames (1867 matched for pre-ablation (post channel creation) and post-ablation phases). Treatments with the modified Excimer laser catheters resulted in a significant increase in lumen area of 5.5 ± 3.2-mm(2) (95% CI 4.3-6.8, p < 0.0001) and reduction in plaque plus media volume of -10.6 ± 36.0 mm(3) (95% CI -25.8 to 4.6, p = 0.1619) whilst giving rise to mainly intramural hematoma formations post Turbo-Booster laser treatment in 55% of frames assessed and 24% medial dissections with less than 1% adventitial disruption. The Excimer laser based Turbo-Booster treatment of peripheral artery lesions resulted in significant plaque debulking and increased lumen diameter with negligible degree of adventitial layer injury.

  6. Usual Dose of Simvastatin Does Not Inhibit Plaque Progression and Lumen Loss at the Peri-Stent Reference Segments after Bare-Metal Stent Implantation: A Serial Intravascular Ultrasound Analysis

    PubMed Central

    Hong, Young Joon; Choi, Yun Ha; Ma, Eun Hye; Ko, Jum Suk; Lee, Min Goo; Park, Keun Ho; Sim, Doo Sun; Yoon, Nam Sik; Youn, Hyun Ju; Kim, Kye Hun; Park, Hyung Wook; Kim, Ju Han; Ahn, Youngkeun; Cho, Jeong Gwan; Park, Jong Chun; Kang, Jung Chaee

    2010-01-01

    Background/Aims The aim of this study was to assess the effects of a usual dose of simvastatin (20 mg/day) on plaque regression and vascular remodeling at the peri-stent reference segments after bare-metal stent implantation. Methods We retrospectively investigated serial intravascular ultrasound (IVUS) findings in 380 peri-stent reference segments (184 proximal and 196 distal to the stent) in 196 patients (simvastatin group, n = 132 vs. non-statin group, n = 64). Quantitative volumetric IVUS analysis was performed in 5-mm vessel segments proximal and distal to the stent. Results IVUS follow-up was performed at a mean of 9.4 months after stenting (range, 5 to 19 months). No significant differences were observed in the changes in mean plaque plus media (P&M) area, mean lumen area, and mean external elastic membrane (EEM) area from post-stenting to follow-up at both proximal and distal edges between the simvastatin and non-statin group. Although lumen loss within the first 3 mm from each stent edge was primarily due to an increase in P&M area rather than a change in EEM area, and lumen loss beyond 3 mm from each stent edge was due to a combination of increased P&M area and decreased EEM area, no significant differences in changes were observed in P&M, EEM, and lumen area at every 1-mm subsegment between the simvastatin and non-statin group. Conclusions A usual dose of simvastatin does not inhibit plaque progression and lumen loss and does not affect vascular remodeling in peri-stent reference segments in patients undergoing bare-metal stent implantation. PMID:21179272

  7. Online PC-based integration of digital intracoronary ultrasound images into angiographic images during cardiac catheterization.

    PubMed

    Sievers, Burkhard; Böse, Dirk; Sack, Stefan; Philipp, Sebastian; Wieneke, Heinrich; Erbel, Raimund

    2008-08-18

    In recent years, intravascular ultrasound (IVUS) has evolved as an important adjunct to angiography, providing insights that are significantly altering conventional paradigms in diagnosis and therapy. However, major drawbacks in the use of IVUS relied on the fact that a heavy console had to be moved from lab to lab, and extensive time for set up and image analysis. This additional time and the decrease in patients' through-put has not been applicable in clinical practice for many labs. Our manuscript concerns a novel PC-based platform for IVUS that enables the online intergration of digital intracoronary ultrasound images into angiographic images. This new technique offers remote operation, multiple control devices and custom viewing options. The PC-based platform enables IVUS images to be viewed simultaneously from multiple vantage points in the lab, and allows for multiple user interfaces.

  8. Plaque characteristics of thin-cap fibroatheroma evaluated by OCT and IVUS.

    PubMed

    Miyamoto, Yoshinori; Okura, Hiroyuki; Kume, Teruyoshi; Kawamoto, Takahiro; Neishi, Yoji; Hayashida, Akihiro; Yamada, Ryotaro; Imai, Koichiro; Saito, Ken; Yoshida, Kiyoshi

    2011-06-01

    The purpose of this study was to assess plaque characteristics of optical coherence tomography (OCT)-derived thin-cap fibroatheroma (TCFA) by integrated backscatter intravascular ultrasound (IB-IVUS). Radiofrequency signal-derived IVUS tissue characterization technology has become clinically available and provided objective and quantitative plaque characteristics of the coronary vessel wall. Integrated backscatter IVUS is one of the tissue characterization methods that can possibly provide quantitative plaque characteristics of the OCT-derived TCFA. Eighty-one coronary lesions with plaque burden >40% were selected and analyzed with both IB-IVUS and OCT. The OCT-derived TCFA was defined as a presence of thin fibrous cap (<65 μm) overlying a signal-poor lesion with diffuse border representing a lipid-rich plaque. By conventional gray-scale IVUS, external elastic membrane (EEM) cross-sectional area (CSA), lumen CSA, plaque plus media (P+M) CSA, plaque burden and remodeling index were measured. By IB-IVUS, plaque characteristics were further classified as fibrosis, dense fibrosis, calcification, or lipid pool. Optical coherence tomography identified 40 TCFAs (49%) and 41 non-TCFAs. The EEM CSA, P+M CSA, plaque burden, and remodeling index were significantly larger in OCT-derived TCFA than non-TCFA. By IB-IVUS, percentage lipid pool area (= lipid pool area/P+M CSA × 100) was significantly higher (62.4 ± 12.8% vs. 38.4 ± 13.1%, p<0.0001) and percentage fibrosis area (= fibrosis area/P+M CSA × 100) was significantly lower (34.6 ± 11.4% vs. 50.5 ± 8.7%, p<0.0001) in OCT-derived TCFA than non-TCFA. By receiver-operator characteristic curve analysis, percentage lipid pool area ≥55%, percentage fibrosis area ≤41%, and remodeling index ≥1.0 were predictors of OCT-derived TCFA. The OCT-derived TCFA had larger plaque burden and positive remodeling with predominant lipid component and less fibrous plaque assessed by IB-IVUS. Copyright © 2011 American College of

  9. OCT compared with IVUS in a coronary lesion assessment: the OPUS-CLASS study.

    PubMed

    Kubo, Takashi; Akasaka, Takashi; Shite, Junya; Suzuki, Takahiko; Uemura, Shiro; Yu, Bo; Kozuma, Ken; Kitabata, Hironori; Shinke, Toshiro; Habara, Maoto; Saito, Yoshihiko; Hou, Jingbo; Suzuki, Nobuaki; Zhang, Shaosong

    2013-10-01

    The aim of this study was to investigate the reliability of frequency domain optical coherence tomography (FD-OCT) for coronary measurements compared with quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS). Accurate luminal measurement is expected in FD-OCT because this technology offers high resolution and excellent contrast between lumen and vessel wall. In 5 medical centers, 100 patients with coronary artery disease were prospectively studied by using angiography, FD-OCT, and IVUS. In addition, 5 phantom models of known lumen dimensions (lumen diameter 3.08 mm; lumen area 7.45 mm(2)) were examined using FD-OCT and IVUS. Quantitative image analyses of the coronary arteries and phantom models were performed by an independent core laboratory. In the clinical study, the mean minimum lumen diameter measured by QCA was significantly smaller than that measured by FD-OCT (1.81 ± 0.72 mm vs. 1.91 ± 0.69 mm; p < 0.001) and the minimum lumen diameter measured by IVUS was significantly greater than that measured by FD-OCT (2.09 ± 0.60 mm vs. 1.91 ± 0.69 mm; p < 0.001). The minimum lumen area measured by IVUS was significantly greater than that by FD-OCT (3.68 ± 2.06 mm(2) vs. 3.27 ± 2.22 mm(2); p < 0.001), although a significant correlation was observed between the 2 imaging techniques (r = 0.95, p < 0.001; mean difference 0.41 mm(2)). Both FD-OCT and IVUS exhibited good interobserver reproducibility, but the root-mean-squared deviation between measurements was approximately twice as high for the IVUS measurements compared with the FD-OCT measurements (0.32 mm(2) vs. 0.16 mm(2)). In a phantom model, the mean lumen area according to FD-OCT was equal to the actual lumen area of the phantom model, with low SD; IVUS overestimated the lumen area and was less reproducible than FD-OCT (8.03 ± 0.58 mm(2) vs. 7.45 ± 0.17 mm(2); p < 0.001). The results of this prospective multicenter study demonstrate that FD-OCT provides accurate and reproducible

  10. An Integrated System for Superharmonic Contrast-Enhanced Ultrasound Imaging: Design and Intravascular Phantom Imaging Study.

    PubMed

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

    2016-09-01

    Superharmonic contrast-enhanced ultrasound imaging, also called acoustic angiography, has previously been used for the imaging of microvasculature. This approach excites microbubble contrast agents near their resonance frequency and receives echoes at nonoverlapping superharmonic bandwidths. No integrated system currently exists could fully support this application. To fulfill this need, an integrated dual-channel transmit/receive system for superharmonic imaging was designed, built, and characterized experimentally. The system was uniquely designed for superharmonic imaging and high-resolution B-mode imaging. A complete ultrasound system including a pulse generator, a data acquisition unit, and a signal processing unit were integrated into a single package. The system was controlled by a field-programmable gate array, on which multiple user-defined modes were implemented. A 6-, 35-MHz dual-frequency dual-element intravascular ultrasound transducer was designed and used for imaging. The system successfully obtained high-resolution B-mode images of coronary artery ex vivo with 45-dB dynamic range. The system was capable of acquiring in vitro superharmonic images of a vasa vasorum mimicking phantom with 30-dB contrast. It could detect a contrast agent filled tissue mimicking tube of 200 μm diameter. For the first time, high-resolution B-mode images and superharmonic images were obtained in an intravascular phantom, made possible by the dedicated integrated system proposed. The system greatly reduced the cost and complexity of the superharmonic imaging intended for preclinical study. Significant: The system showed promise for high-contrast intravascular microvascular imaging, which may have significant importance in assessment of the vasa vasorum associated with atherosclerotic plaques.

  11. Intravascular photoacoustic imaging of human coronary atherosclerosis

    NASA Astrophysics Data System (ADS)

    Jansen, Krista; van der Steen, Antonius F. W.; Springeling, Geert; van Beusekom, Heleen M. M.; Oosterhuis, J. Wolter; van Soest, Gijs

    2011-03-01

    We demonstrate intravascular photoacoustic imaging of human coronary atherosclerotic plaque. We specifically imaged lipid content, a key factor in vulnerable plaques that may lead to myocardial infarction. An integrated intravascular photoacoustics (IVPA) and ultrasound (IVUS) catheter with an outer diameter of 1.25 mm was developed. The catheter comprises an angle-polished optical fiber adjacent to a 30 MHz single-element transducer. The ultrasonic transducer was optically isolated to eliminate artifacts in the PA image. We performed measurements on a cylindrical vessel phantom and isolated point targets to demonstrate its imaging performance. Axial and lateral point spread function widths were 110 μm and 550 μm, respectively, for PA and 89 μm and 420 μm for US. We imaged two fresh human coronary arteries, showing different stages of disease, ex vivo. Specific photoacoustic imaging of lipid content, is achieved by spectroscopic imaging at different wavelengths between 1180 and 1230 nm.

  12. Knuckle technique guided by intravascular ultrasound for in-stent restenosis occlusion treatment

    PubMed Central

    Tasic, Mladen; Jagic, Nikola; Miloradovic, Vladimir; Nikolic, Dusan

    2015-01-01

    One of the rarest lesions is in-stent restenosis chronic total occlusion (CTO). Limited data suggest that the treatment success rate is dependent on the possibility to cross into the lumen of an occluded stent, and the decision about what technique to use varies by operator preference. The knuckle technique is used to create a deliberate dissection plane in various CTO techniques. A guide wire is pushed until a complex loop is formed and advanced through the lesion. In this report we present a case where a knuckle wire guided by intravascular ultrasound control is used to penetrate the distal cap in an in-stent restenosis CTO lesion. PMID:25848374

  13. SNR enhancement for catheter based intravascular photoacoustic/ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Cho, Seonghee; Choi, Changhoon; Ahn, Joongho; Kim, Taehoon; Park, Sungjo; Park, Hyoeun; Kim, Jinmoo; Lee, Seunghoon; Kang, Yeonsu; Chang, Kiyuk; Kim, Yongmin; Kim, Chulhong

    2017-03-01

    Atherosclerosis, the most common cause of death, kills suddenly by arterial occlusion by thrombosis, which is caused by plaque rupture. Because a growing necrotic core is highly related to plaque rupture in atherosclerosis, distinguishing between fibrous plaque and lipid-rich plaque in real time is important, but has been challenging. Real-time photoacoustic imaging requires a pulse laser with high repetition rate, which tends to sacrifice pulse energy. Furthermore, a high repetition rate is hard to achieve at lipid-sensitive wavelengths, such as 1210 nm and 1720 nm. To address the unmet need, we have developed the algorithm for PA imaging. We successfully acquired ex vivo PA images from the lipid cores of arterial plaques in rabbit arteries, using a low-power 1064-nm laser. PA images were acquired with a custom-made catheter employing a single-element 40-MHz ultrasound transducer and a compact 1064-nm laser with the pulse energy of 5 μJ and the repetition rate of 24 kHz. Acquired raw data were processed in the time and frequency domains. In the time domain, a delay-and-sum algorithm was used for image enhancement. In the frequency domain, signals exceeding the MTF were removed. As a result, SNR was increased by about 10 dB without degrading spatial resolution. We were able to achieve high-speed and high-SNR lipid target imaging in animals in spite of the low lipid sensitivity of a 1064nm laser. These results show good promise for detecting lipid-rich plaques with a compact high-speed laser, which can be easily adapted for target clinical applications.

  14. The assessment of Shin's method for the prediction of creatinine kinase-MB elevation after percutaneous coronary intervention: an intravascular ultrasound study.

    PubMed

    Shin, Eun-Seok; Garcia-Garcia, Hector M; Garg, Scot; Park, Jongha; Kim, Shin-Jae; Serruys, Patrick W

    2011-07-01

    Cardiac enzyme release is common after percutaneous coronary intervention (PCI). At present there is no established relationship between the quantity of necrotic core and dense calcium, as assessed by Shin's method using intravascular ultrasound virtual histology (VH-IVUS), and post-PCI creatinine kinase-MB (CK-MB) elevation. A total of 112 consecutive patients with unstable angina and a normal pre-PCI CK-MB level were imaged using VH-IVUS. Patients were divided into 2 groups according to the presence (CK-MB group, n = 22) or absence (non CK-MB group, n = 90) of a post-PCI CK-MB elevation >1.0 the upper limit of normal (3.6 ng/ml). Using Shin's method contours were drawn around the IVUS catheter (instead of the lumen), and the vessel. Mean area and volume of necrotic core and dense calcium were significantly greater in CK-MB group than in non CK-MB group (1.7 ± 0.9 mm(2) vs. 0.9 ± 0.6 mm(2), P < 0.001; 17.2 ± 8.8 mm(3) vs. 8.8 ± 5.8 mm(3), P < 0.001, and 0.9 ± 0.6 mm(2) vs. 0.4 ± 0.4 mm(2), P = 0.001; 9.1 ± 5.8 mm(3) vs. 3.9 ± 3.7 mm(3), P < 0.001, respectively). Percent necrotic core and dense calcium areas calculated by external elastic membrane (EEM) area were significantly greater in CK-MB group than in non CK-MB group (11.9 ± 5.1 vs. 6.6 ± 4.0%, P < 0.001 and 6.5 ± 4.0 vs. 3.0 ± 2.9%, P < 0.001, respectively). In the multivariate analysis, dense calcium volume and percent necrotic core to EEM at the most diseased segment were the only independent predictors of post-PCI CK-MB elevation (odds ratio: 1.22; 95% confidence interval: 1.09-1.37, P < 0.001 and odds ratio: 1.26; 95% confidence interval: 1.12-1.43, P < 0.001). Lesions with a greater amount of dense calcium volume and percent necrotic core to EEM, which can be easily identified and quantified on VH-IVUS analyzed using Shin's method, are responsible for post-PCI CK-MB elevation. With a rapid analyzing time, Shin's method may increase the

  15. Novel Method for Real Time Co-Registration of IVUS and Coronary Angiography.

    PubMed

    Frimerman, Aharon; Abergel, Eitan; Blondheim, David S; Shotan, Avraham; Meisel, Simcha; Shochat, Michael; Punjabi, Pritesh; Roguin, Ariel

    2016-04-01

    We present our experience with a novel method for real time co-registration of intravascular ultrasound (IVUS) and coronary angiography. A major limitation of the current practice of concomitant use of coronary angiography and IVUS is that the locations of the acquired IVUS images are not correlated with their exact locations on the vessel roadmap obtained by coronary angiography. Phantoms simulating the coronary tree were used to test the accuracy and potential of co-registration. Subsequently we examined patients who underwent IVUS during cardiac catheterization. Analysis and feasibility were performed in 42 arteries of 36 patients. The statistical validation in phantoms resulted in a co-registration accuracy of 1.12 mm. The length measurement on an angiogram resulted in an accuracy of 0.38 mm. Co-registration in patients was successful in all cases and four categories were assisted by 1(bad) to 5 (good) grading. Accuracy (the co-registration precision in pointing at the exact corresponding location): 4.8±0.41; Ease of use and workflow: 4.74±0.44; Stent landing zone detection and evaluation: 4.58±0.5; Stent landing zone length and diameter measurement: 4.94±0.23. The co-registration error was estimated as no more than 1 mm. In this pilot study, we found that the novel IVUS and coronary angiography co-registration method is accurate, easy to use, fast and user-friendly. This method precludes the need to use motorized automated pull back device. © 2016, Wiley Periodicals, Inc.

  16. Does calcium burden impact culprit lesion morphology and clinical results? An ADAPT-DES IVUS substudy.

    PubMed

    Shan, Peiren; Mintz, Gary S; Witzenbichler, Bernhard; Metzger, D Christopher; Rinaldi, Michael J; Duffy, Peter L; Weisz, Giora; Stuckey, Thomas D; Brodie, Bruce R; Généreux, Philippe; Crowley, Aaron; Kirtane, Ajay J; Stone, Gregg W; Maehara, Akiko

    2017-12-01

    Increasing coronary lesion calcification is thought to be associated with adverse percutaneous coronary intervention (PCI) and clinical outcomes. We investigated the effects of calcium burden on culprit lesion morphology and clinical events after intravascular ultrasound (IVUS)-guided PCI in the ADAPT-DES study. ADAPT-DES was a prospective, multicenter registry of 8582 consecutive patients undergoing successful PCI using DES. A pre-specified virtual histology (VH)-IVUS substudy of 638 culprit lesions (638 patients) had both pre- and post-PCI VH-IVUS. We divided lesions into tertiles according to pre-PCI percent dense calcium volume (DCV%=dense calcium/plaque volume×100). Compared with low and intermediate DCV% tertiles, patients in the high DCV% tertile had the largest arc of superficial calcium, highest percentage of necrotic core volume, and smallest remodeling index; they were also more likely to have advanced lesion morphology such as attenuated plaque and VH thin-cap fibroatheromas. In the high DCV% tertile IVUS guidance was associated with a minimum stent area that was smaller than tertiles with less calcium (p=0.01), but acceptable range, and similar stent expansion (73.8±16.8% vs. 74.0±19.2% vs. 72.4±17.3%, p=0.62) after more frequent use of rotational atherectomy and higher maximum inflation pressure. There was no significant association between pre-PCI DCV% and 2-year target lesion revascularization or major adverse cardiac events (cardiac death, myocardial infarction, or stent thrombosis). Increasing coronary artery calcification burden was associated with more advanced, complex VH-IVUS lesion morphology, but not with adverse clinical outcomes, perhaps due to more aggressive PCI techniques that optimized stent expansion. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  17. A prospective evaluation of using IVUS during percutaneous superficial femoral artery interventions.

    PubMed

    Hitchner, Elizabeth; Zayed, Mohamed; Varu, Vinit; Lee, George; Aalami, Oliver; Zhou, Wei

    2015-01-01

    The outcomes of endovascular interventions of the superficial femoral artery (SFA) are variable. Completion angiography is typically performed to confirm satisfactory outcomes after SFA angioplasty and/or stenting. However, two-dimensional angiography may not accurately reflect the extent of residual stenosis. We sought to determine whether intravascular ultrasound (IVUS) can help with residual disease assessment and procedure outcome. Patients with anticipated SFA disease were prospectively recruited to the study. Patients with primary SFA disease on diagnostic angiography were included. After SFA endovascular intervention with angioplasty and/or stenting, a completion angiogram was performed to confirm satisfactory results before IVUS evaluation. IVUS-detected maximal residual stenosis, maximal residual lesion volume, and number of nonconsecutive posttreatment SFA segments with >50% residual stenosis were evaluated. Periprocedural ankle-brachial indexes (ABIs), Short Form 36 (SF-36) surveys, and Walking Impairment Questionnaires were also collected. Fifty-nine patients were prospectively enrolled. Thirty-three received angioplasty only, and 26 received angioplasty and stenting. All patients were men, mean age was 67 years, and major comorbidities included coronary artery disease (53%), active smoking (56%), hypertension (88%), and diabetes (68%). The angioplasty-only cohort had more nonconsecutive areas of >50% residual stenosis (P = 0.004), greater residual stenosis (P = 0.03), and smaller minimal lumen diameters after treatment (P = 0.01) than the angioplasty and stenting cohort. However, there was no significant difference in ABI between the 2 groups and no difference in ABI improvement after intervention. Sixty-four percent of all patients demonstrated a >0.2 increase in postintervention ABI. Improvement in ABI at 1 month after procedure significantly correlated with postintervention SF-36 survey physical scores (r = 0.435, P = 0.007). IVUS evaluation

  18. Combined NIRS and IVUS imaging detects vulnerable plaque using a single catheter system: a head-to-head comparison with OCT.

    PubMed

    Roleder, Tomasz; Kovacic, Jason C; Ali, Ziad; Sharma, Raman; Cristea, Ecatarina; Moreno, Pedro; Sharma, Samin K; Narula, Jagat; Kini, Annapoorna S

    2014-07-01

    The presence of thin-cap fibroatheromas (TCFA) is associated with high risk of acute coronary syndrome, hence their early detection may identify high-risk patients. In the present study we investigated the ability of a combined imaging catheter with near-infrared spectroscopy (NIRS) plus intravascular ultrasound (IVUS) to detect TCFA in patients with stable coronary artery disease. Optical coherence tomography (OCT) and combined NIRS-IVUS assessment were performed on identical coronary segments. IVUS analysis provided per-segment minimal cross-sectional area (CSA), plaque length (PL), plaque burden (PB), plaque volume (PV), and remodelling index (RI). OCT was used as the gold-standard reference to define TCFA (fibrous cap thickness <65 μm). Plaque lipid content was estimated by NIRS (lipid core burden index [LCBI]). OCT-defined TCFA was present in 18 of 76 segments. IVUS revealed that OCT-defined TCFA were positively remodelled lesions with greater PB and PV, smaller CSA, and longer PL, while NIRS revealed greater LCBI per 2 mm segment (LCBI2mm) (all p<0.001). Greatest accuracy for OCT-defined TCFA detection was achieved using LCBI2mm >315 with RI >1.046 as a combined criterion value. OCT-defined TCFA are characterised by positive vessel remodelling, high plaque burden and greater lipid core burden as assessed by dual NIRS-IVUS imaging.

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

    PubMed

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

    2016-05-01

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

  20. Treatment of deeply located acute intravascular thrombi with therapeutic ultrasound guided by diagnostic ultrasound and intravenous microbubbles.

    PubMed

    Tsutsui, Jeane M; Xie, Feng; Johanning, Jason; Lof, John; Cory, Brian; He, Amming; Thomas, Lewis; Matsunaga, Terry; Unger, Evan; Porter, Thomas R

    2006-09-01

    We sought to determine the added value of simultaneous imaging of intravenously infused microbubbles that are being used to dissolve an intravascular thrombus with therapeutic ultrasound (TUS). In a chronic canine arteriovenous graft occluded by a thrombus, TUS (1 MHz) was applied through a 6-cm-thick tissue-mimicking phantom (measured mean +/- SD peak negative pressure through the phantom, 958 +/- 104 kPa) during an intravenous infusion of either saline (n = 6 occlusions) or lipid-encapsulated microbubbles (ImaRx Therapeutics, Inc, Tucson, AZ). Therapeutic ultrasound was intermittently applied during the microbubble infusion either at set time intervals (n = 6 occlusions) or when simultaneous diagnostic ultrasound (DUS) indicated a sustained presence of microbubbles (n = 12 occlusions). Success was defined as return of rapid flow within the graft (grade 3 flow). Diagnostic ultrasound showed microbubbles moving through small channels within the thrombus before angiographic evidence of flow in the graft. This guided the timing of TUS application better than using set time intervals. Angiographic clearance of the thrombus and restoration of grade 3 flow at 45 minutes of treatment were seen in 33% of deeply located thrombosed grafts treated with TUS at set time intervals and 92% of grafts treated with TUS guided by DUS (P < .001 compared with set time intervals). The use of TUS with intravenous microbubbles has a high success rate in recanalizing deeply located thrombosed arteriovenous grafts when performed with DUS guidance.

  1. Positive remodeling at 3 year follow up is associated with plaque-free coronary wall segment at baseline: a serial IVUS study.

    PubMed

    Wentzel, Jolanda J; Gijsen, Frank J H; van der Giessen, Rose; Rodriguez-Granillo, Gaston; Schuurbiers, Johan C H; Regar, E; de Feyter, Pim J; van der Steen, Antonius F W

    2014-09-01

    At present it is unknown what limits the arterial remodeling process during atherosclerotic plaque formation. In healthy arteries remodeling is regulated by the shear stress induced response by the endothelium. As endothelium at the plaque site is assumed to be dysfunctional, we tested the hypothesis that plaque free wall (PFW) determines vascular remodeling during atherosclerotic plaque build-up. 66 human coronary ROIs (38 patients) were studied at baseline and at 3 years follow up applying intravascular ultrasound (IVUS). From the IVUS images the lumen and external elastic membrane contours were delineated to assess wall thickness (WT), vessel area (VA), Plaque Area (PA) and plaque burden (PA/VA*100%). WT < 0.5 mm was defined as normal and determined the arc of the PFW (0-360°). Positive remodeling was defined as relative difference of VA over time >5%. At baseline, IVUS-PFW was inversely related to plaque burden (p < 0.05). Positive remodeling was most frequently observed in ROIs with IVUS-PFW > 180° (i.e. larger than half of the circumference) compared to PFW < 180° (55% vs. 12%, p < 0.05). Accordingly, plaques with IVUS-PFW > 180° at baseline had the largest change in VA (1.1 ± 2.1 vs. -0.4 ± 0.6 mm(2), p < 0.05) with an odds ratio of 9.2 to develop positive remodeling. Our serial IVUS data show that IVUS-PFW is a determinant of vascular remodeling. ROIs with PFW > 180 at baseline had the highest probability to undergo positive remodeling. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. 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.

  3. Intravascular ultrasound

    MedlinePlus

    ... by placing the transducer on the skin. A computer measures how the sound waves reflect off blood ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  4. Comprehensive serial study of dynamic remodeling of atherosclerotic coronary arteries using IVUS

    NASA Astrophysics Data System (ADS)

    Chen, Zhi; Wahle, Andreas; Zhang, Ling; Kovarnik, Tomas; Lopez, John J.; Sonka, Milan

    2016-03-01

    We present a semi-automated approach to comprehensively examine coronary remodeling over the entire length of intravascular ultrasound (IVUS) imaged vessels. Serial measurements at baseline and 12-month follow-up are analyzed rather than static data obtained at a single time point. Every IVUS pullback is segmented automatically, and then reviewed and algorithmically refined by an expert using a computer-aided just-enough-interaction approach. Subsequently, pairs of serial IVUS pullbacks are registered automatically using 3D graph optimization approach. Based on plaque volume increases or decreases over time, pullback frames are divided into two groups -- progression and regression. It is shown that plaque progression rates are positively correlated with percent stenosis (PS) indices (p≪0.01) while plaque regression rates are negatively correlated with percent stenosis indices (p≪0.01). Moreover, for the progression group, adventitia area increases in direct relation with the baseline percent stenosis (p=0.007) when PS is less than 50%. Significance of such a correlation is not observed when percent stenosis exceeds 50%. Conversely, for the regression group, change of adventitia area is relatively constant for percent stenosis <50% but decreases in direct relation with baseline stenosis (p≪0.01) when stenosis > 50%. This strongly suggests that lipid lowering treatment may effectively suppress plaque progression and accelerate plaque regression, especially for larger values of percent stenosis, and further accelerate the corresponding adventitia-remodeling process.

  5. Improving Cardiac Phase Extraction in IVUS Studies by Integration of Gating Methods.

    PubMed

    Maso Talou, Gonzalo D; Larrabide, Ignacio; Blanco, Pablo J; Bezerra, Cristiano Guedes; Lemos, Pedro A; Feijoo, Raul A

    2015-12-01

      Coronary intravascular ultrasound (IVUS) is a fundamental imaging technique for atherosclerotic plaque assessment. However, volume-based data retrieved from IVUS studies can be misleading due to the artifacts generated by the cardiac motion, hindering diagnostic, and visualization of the vessel condition. Then, we propose an image-based gating method that improves the performance of the preexisting methods, delivering a gating in an appropriate time for clinical practice. We propose a fully automatic method to synergically integrate motion signals from different gating methods to improve the cardiac phase estimation. Additionally, we present a local extrema identification method that provides a more accurate extraction of a cardiac phase and, also, a scheme for multiple phase extraction mandatory for elastography-type studies. A comparison with three state-of-the-art methods is performed over 61 in-vivo IVUS studies including a wide range of physiological situations. The results show that the proposed strategy offers: 1) a more accurate cardiac phase extraction; 2) a lower frame oversampling and/or omission in the extracted phase data (error of 1.492 ±0.977 heartbeats per study, mean ± SD); 3) a more accurate and robust heartbeat period detection with a Bland-Altman coefficient of reproducibility (RPC) of 0.23 s, while the second closest method presents an RPC of 0.36 s. The integration of motion signals performed by our method shown an improvement of the gating accuracy and reliability.

  6. 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.

  7. Volume-preserving smoothing of three-dimensional surfaces: application to intravascular ultrasound.

    PubMed

    Zeng, C; Sonka, M

    1998-10-01

    A volume-preserving three-dimensional smoothing approach is described that can be directly applied to 3D medical image data consisting of sets of 2D image slices, e.g., segmented intravascular ultrasound image sequences. Two local smoothing filters ℱ and 𝒢 were designed according to different smoothing goals and their performance was compared. Filtering with the ℱ filter of a relatively large frequency window keeps the important local characteristics of the object and results in little shrinkage while removing noise. Filtering with the Gaussian filter G that has an added volume compensation step results in no global shrinkage and may be used for multiscale filtering. The two filters can be easily extended to n-dimensional filtering. Copyright 1998 Academic Press.

  8. Association between IVUS findings and adverse outcomes in patients with coronary artery disease: the VIVA (VH-IVUS in Vulnerable Atherosclerosis) Study.

    PubMed

    Calvert, Patrick A; Obaid, Daniel R; O'Sullivan, Michael; Shapiro, Leonard M; McNab, Duncan; Densem, Cameron G; Schofield, Peter M; Braganza, Denise; Clarke, Sarah C; Ray, Kausik K; West, Nick E J; Bennett, Martin R

    2011-08-01

    The purpose of this study was to determine whether thin-capped fibroatheromata (TCFA) identified by virtual histology intravascular ultrasound (VH-IVUS) are associated with major adverse cardiac events (MACE) on individual plaque or whole patient analysis. Post-mortem studies have identified TCFA as the substrate for most myocardial infarctions. However, little is known about the natural history of individual TCFA and their link with MACE. VH-IVUS provides a method of identifying plaques in vivo that are similar (although not identical) to histologically defined TCFA, and has been validated in human atherectomy and post-mortem studies. One hundred seventy patients with stable angina or troponin-positive acute coronary syndrome referred for percutaneous coronary intervention (PCI) were prospectively enrolled and underwent 3-vessel VH-IVUS pre-PCI and also post-PCI in the culprit vessel. MACE consisted of death, myocardial infarction, or unplanned revascularization. In all, 30,372 mm of VH-IVUS were analyzed. Eighteen MACE occurred in 16 patients over a median follow-up of 625 days (interquartile range: 463 to 990 days); 1,096 plaques were classified, and 19 lesions resulted in MACE (13 nonculprit lesions and 6 culprit lesions). Nonculprit lesion factors associated with nonrestenotic MACE included VHTCFA (hazard ratio [HR]: 7.53, p = 0.038) and plaque burden >70% (HR: 8.13, p = 0.011). VHTCFA (HR: 8.16, p = 0.007), plaque burden >70% (HR: 7.48, p < 0.001), and minimum luminal area <4 mm(2) (HR: 2.91, p = 0.036) were associated with total MACE. On patient-based analysis, the only factor associated with nonrestenotic MACE was 3-vessel noncalcified VHTCFA (HR: 1.79, p = 0.004). VH-IVUS TCFA was associated with nonrestenotic and total MACE on individual plaque analysis, and noncalcified VHTCFA was associated with nonrestenotic and total MACE on whole-patient analysis, demonstrating that VH-IVUS can identify plaques at increased risk of subsequent events. The preservation

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

    PubMed

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

    2016-11-01

    CENTRAL was a prospective, multicenter, 100 patient study designed to evaluate the ability of a recanalization catheter system to cross chronic total occlusions (CTOs) of the superficial femoral artery while staying within the central vessel lumen. The primary endpoint was the successful crossing of a CTO (≥90% of the length) with the recanalization catheter in the central lumen of the superficial femoral artery in at least one-half of the studied patient population, confirmed by intravascular ultrasound. Secondary endpoints included standardized anatomic damage assessment (the TAPE method) and an assessment of the relationship between the percent of CTO crossing and TAPE scores to the rate of target-lesion revascularization (TLR) at 30 days and 6 months. The mean age of the occlusions was 16.6 ± 22.28 months (range, 1-120 months), the average occlusion length reported by the sites was 132.1 ± 87.69 mm (range, 4-300 mm), and a majority of lesions were moderately (42.0%) or severely (32.0%) calcified. In 43/85 (50.6%) of the evaluable intravascular ultrasound images, the recanalization catheter successfully navigated the central lumen of the CTO (ie, ≥90% luminal crossing) with >50% luminal crossing in 64/85 (75.3%) of cases. The 6-month TLR rate was significantly lower in patients where the CTO was crossed ≥90% in the central vessel lumen (4.7%) compared with crossings <90% (20.6%; P=.04). The 6-month TLR rate was 3.5% in patients with a favorable TAPE score of 0-4 and 36.8% with an unfavorable TAPE score of 5-8 (P<.001). Use of a recanalization catheter in complex superficial femoral artery CTO crossings achieved intraluminal crossings in >50% of cases and decreased anatomic damage, which appeared to offer a significant advantage in 6-month TLR rates.

  10. 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.

  11. An evaluation of dual source computed tomography used with the de Weert classification to detect vulnerable plaque, using IVUS virtual histology as a standard of reference.

    PubMed

    Dołęga-Kozierowski, Bartosz; Klimeczek, Piotr; Lis, Michał; Krycińska, Róża; Chrapusta, Anna; Zaleska-Dorobisz, Urszula; Garcarek, Jerzy; Witkiewicz, Wojciech

    2017-01-01

    One of the main risk factors for cerebral ischemic events is atherosclerotic disease of the internal carotid artery (ICA). Nowadays, increasing attention is being paid to the relationship between the morphological features of atherosclerotic plaque and the occurrence of stroke. Several studies have demonstrated that the presence of specific vulnerable plaque types, with a large lipid core and thin fibrous cap, can be used as an independent risk predictor of cerebral ischemic events. The present study is an attempt to develop the method of plaque surface morphology assessment presented by de Weert et al. by correlating the results of Dual Source Computed Tomography (DSCT) with those from intravascular ultrasound virtual histology (IVUS-VH). A group of 30 symptomatic patients (13 men and 17 women; 72 ± 9 years) with ICA stenosis suspected on the basis of ultrasound imaging (US) and confirmed to be above 70% in DSCT underwent intravascular ultrasound (IVUS) imaging. The results of DSCT were categorized according to the de Weert classification. There were 13 cases (43%) with smooth wall surfaces, 10 cases (33%) with discreet wall irregularities, and seven cases (23%) with incursions of contrast, indicating the presence of ulceration. In the IVUS-VH examinations, 4 out of 30 cases (13%) were identified as having adaptive intimal thickening (AIT), 4 (13%) as showing pathological intimal thickening (PIT), 6 (20%) with fibroatheromas (FA), six (20%) with fibrocalcific plaque (FCa), and 10 (33%) as having thin-cap fibroatheroma (TCFA), which is high-risk plaque. Comparing the above results showed that all the patients with confirmed wall ulceration in DSCT were characterized as having high-risk plaque in IVUS-VH. Using DSCT with the de Weert classification of plaque surface morphology makes reliable detection of ulcerations possible; therefore, this could become a significant new technique to improve current imaging protocols for patients with a high risk of ischemic

  12. 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

  13. Relation between plaque progression and low-density lipoprotein cholesterol during aging as assessed with serial long-term (> or =12 months) follow-up intravascular ultrasound of the left main coronary artery.

    PubMed

    Hartmann, Marc; von Birgelen, Clemens; Mintz, Gary S; van Houwelingen, Gert K; Eggebrecht, Holger; Böse, Dirk; Wieneke, Heinrich; Verhorst, Patrick M J; Erbel, Raimund

    2006-12-01

    Because of the clinical benefit of lipid lowering in older patients, we hypothesized that the relation between low-density lipoprotein (LDL) cholesterol serum levels and coronary plaque progression may persist throughout aging. We analyzed serial intravascular ultrasound (IVUS) data of 60 left main stems (18 +/- 9 months apart) and evaluated the relation between LDL cholesterol levels and coronary plaque progression at different ages. The population (n = 60) was divided into 3 groups according to age: tertile 1 (n = 20) was a mean age of 48 +/- 6 years (median 51, range 33 to 55), tertile 2 (n = 20) was a mean age of 58 +/- 2 years (median 59, range 55 to 61), and tertile 3 (n = 20) was a mean age of 66 +/- 6 years (median 65, range 61 to 83). Between groups, there was no significant difference in non-age-related demographics, clinical data, lipid profiles, or medications (e.g., statins). There was a positive linear relation between LDL cholesterol and annual changes in plaque plus media area in all age tertiles, which was statistically significant in tertiles 2 and 3 (r = 0.56, p <0.01; r = 0.50, p <0.02) and showed a strong trend in tertile 1 (r = 0.41, p = 0.07). The estimated LDL cholesterol thresholds, which, as determined by regression analysis, would correspond to no plaque progression, were 74, 60, and 78 mg/dl, respectively, in tertiles 1, 2, and 3. In conclusion, serial IVUS data in left main coronary arteries suggest that the relation between LDL cholesterol serum levels and plaque progression persists during aging.

  14. Absence of accelerated atherosclerotic disease progression after intracoronary infusion of bone marrow derived mononuclear cells in patients with acute myocardial infarction--angiographic and intravascular ultrasound--results from the TErapia Celular Aplicada al Miocardio Pilot study.

    PubMed

    Arnold, Roman; Villa, Adolfo; Gutiérrez, Hipólito; Sánchez, Pedro L; Gimeno, Federico; Fernández, Maria E; Gutiérrez, Oliver; Mota, Pedro; Sánchez, Ana; García-Frade, Javier; Fernández-Avilés, Francisco; San Román, Jose A

    2010-06-01

    We tried to evaluate a putative negative effect on coronary atherosclerosis in patients receiving intracoronary infusion of unfractionated bone marrow mononuclear cells (BMMC) following an acute ST-elevation myocardial infarction. Peripheral blood mononuclear cells or enriched CD133(+) BMMC have been associated with accelerated atherosclerosis of the distal segment of the infarct related artery (IRA). Thirty-seven patients with ST-elevation myocardial infarction from the TECAM pilot study underwent intracoronary infusion of autologous BMMC 9 +/- 3.1 days after onset of symptoms. We compared angiographic changes from baseline to 9 months of follow-up in the distal non-stented segment of the IRA, as well as in the contralateral coronary artery, with a matched control group. A subgroup of 15 treated patients underwent additional IVUS within the distal segment of the IRA. No difference between stem cell and control group were found regarding changes in minimum lumen diameter (0.006 +/- 0.42 vs 0.06 +/- 0.41 mm, P = ns) and the percentage of stenosis (-2.68 +/- 12.33% vs -1.78 +/- 8.75%, P = ns) at follow-up. Likewise, no differences were seen regarding changes in the contralateral artery (minimum lumen diameter -0.004 +/- 0.54 mm vs -0.06 +/- 0.35 mm, P = ns). In the intravascular ultrasound substudy, no changes were demonstrated comparing baseline versus follow-up in maximum area stenosis and plaque volume. In this pilot study, analysis of a subgroup of patients found that intracoronary injection of unfractionated BMMC in patients with acute ST-elevation myocardial infarction was not associated with accelerated atherosclerosis progression at mid term. Prospective, randomised studies in large cohorts with long-term angiographic and intravascular ultrasound follow-up are necessary to determine the safety of this therapy. Copyright 2010 Mosby, Inc. All rights reserved.

  15. IVUS-guided treatment strategies for definite late and very late stent thrombosis.

    PubMed

    Gomez-Lara, Josep; Salvatella, Neus; Gonzalo, Nieves; Hernández-Hernández, Felipe; Fernandez-Nofrerias, Eduard; Sánchez-Recalde, Angel; Bastante, Teresa; Marcano, Ana; Romaguera, Rafael; Ferreiro, José-Luis; Roura, Gerard; Teruel, Luis; Ariza-Solé, Albert; Miranda-Guardiola, Faustino; Rodríguez García-Abad, Vera; Gomez-Hospital, Joan-Antoni; Alfonso, Fernando; Cequier, Angel

    2016-12-10

    Our aim was to describe the intravascular ultrasound (IVUS) findings of patients with late stent thrombosis (ST) undergoing percutaneous intervention, and to compare the pre- and post-intervention IVUS findings of patients treated with balloon angioplasty (BA) vs. additional stent implantation (ASI). A total of 117 patients with late ST imaged with IVUS were included (51.2% had drug-eluting stent ST). Treatment was left to the operator's discretion: BA was performed in 53.8% and ASI in 46.2%. Pre-intervention, incomplete stent apposition (ISA) was observed in 69.8% vs. 63.0% (p=0.43), underexpansion in 33.3% vs. 18.5% (p=0.07) and restenosis in 15.9% vs. 27.8% (p=0.12), respectively. Post-intervention, persistent ISA was observed in 37.2% vs. 60.9% (p=0.03) and malapposition volume decreased by 43.6% vs. 2.6% (p=0.03). Persistent underexpansion was observed in 9.3% vs. 17.4% (p=0.26); however, the stent expansion index was largely increased with BA (from 0.75 to 0.88) compared to ASI (from 0.80 to 0.82); p=0.046. At two years, recurrent ST was observed in one (1.7%) vs. four (7.7%) patients, respectively; p=0.09. Non-optimal IVUS criteria of stent implantation are often observed in patients with late ST. Treatment of late ST with BA leads to a larger reduction of malapposition and underexpansion with respect to ASI and is associated with favourable outcomes.

  16. [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.

  17. Impact of chronic statin therapy on clinical presentation and underlying lesion morphology in patients undergoing percutaneous intervention: an ADAPT-DES IVUS substudy.

    PubMed

    Kadohira, Tadayuki; Mintz, Gary S; Souza, Cristiano F; Witzenbichler, Bernhard; Metzger, D Christopher; Rinaldi, Michael J; Mazzaferri, Ernest L; Duffy, Peter L; Weisz, Giora; Stuckey, Thomas D; Brodie, Bruce R; Crowley, Aaron; Kirtane, Ajay J; Stone, Gregg W; Maehara, Akiko

    2017-05-01

    Previous intravascular ultrasound (IVUS) studies have not established a relationship between chronic statin use and plaque morphology and composition in patients undergoing percutaneous coronary intervention (PCI). We sought to use pre-PCI grayscale and virtual histology (VH)-IVUS to assess plaque morphology and composition in patients treated with chronic statin therapy compared with patients who were not taking statins before admission and PCI. In a prespecified substudy of the Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents study, pre-PCI grayscale and VH-IVUS were performed in 780 patients with 916 culprit and 765 nonculprit lesions. Overall, 338 patients were treated with chronic statin therapy before admission. Statin-treated patients were older and had a higher prevalence of coronary risk factors. Statin-treated patients were more likely to present with stable angina, whereas non-statin-treated patients more frequently presented with acute myocardial infarction. Grayscale and VH-IVUS findings showed that lesions in statin-treated patients had a smaller plaque burden, but more dense calcium. Statin-treated patients had more calcified thick-cap fibroatheromas (9.2 vs. 3.7%, P=0.0007), but fewer VH-defined thin-cap fibroatheromas (45.2 vs. 56.1%, P=0.001) or plaque ruptures (26.6 vs. 38.4%, P=0.0001). In a propensity-matched population (n=249 in each group), similar results were obtained as regards clinical presentation and grayscale and VH-IVUS findings. Chronic statin use in patients with coronary artery disease was associated with more stable clinical presentation and IVUS findings consistent with greater lesion stability (fewer VH-thin-cap fibroatheromas and plaque ruptures and more calcified thick-cap fibroatheromas).

  18. Assessment of coronary atherosclerosis progression and regression at bifurcations using combined IVUS and OCT.

    PubMed

    Diletti, Roberto; Garcia-Garcia, Hector M; Gomez-Lara, Josep; Brugaletta, Salvatore; Wykrzykowska, Joanna J; van Ditzhuijzen, Nienke; van Geuns, Robert Jan; Regar, Evelyn; Ambrosio, Giuseppe; Serruys, Patrick W

    2011-07-01

    The aim of this study was to evaluate the progression of atherosclerotic coronary plaques at bifurcations, using combined intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT). Pathological findings reveal that atherosclerotic plaques characterized by the presence of large necrotic cores (NCs) with fibrous cap thicknesses < 65 μm are more prone to rupture. Accuracy in the detection of high-risk plaques could be improved by the combined use of IVUS-VH and OCT. IVUS-VH and OCT are 2 imaging modalities with different lateral resolutions and different depths of penetration. To provide a precise matching of the images, bifurcations were used as landmarks. IVUS-VH and OCT were performed in 56 bifurcations from 24 patients at baseline and at 6-month follow-up. All patients were treated with standard medical therapy. Bifurcations were studied at the proximal, in-bifurcation, and distal regions. Plaques were classified according to their composition as assessed by IVUS-VH and fibrous cap thickness as quantified by OCT. At baseline, 27 NC-rich plaques were found. At 6-month follow-up, 22 (81%) did not show any significant change. Four new NC-rich lesions developed. At both time points, percent NC was higher and the fibrous cap was thinner at the proximal bifurcation rim compared with the distal. There were no significant changes in percent NC and fibrous cap thickness in the 3 bifurcation regions between baseline and follow-up examinations. No major cardiovascular events due to bifurcation lesion progression were observed. The combined use of IVUS-VH and OCT is a reliable tool to serially assess plaque progression and regression, and in the present study it was demonstrated to be safe and feasible. At 6-month follow-up, in this post-percutaneous coronary intervention patient population, most high-risk plaques remained unchanged, retaining their imaging classifications, nevertheless appearing to have remained clinically silent. Copyright

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

    PubMed

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

    2013-09-01

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

  20. Multidetector computed tomography for the evaluation of coronary artery disease; the diagnostic accuracy in calcified coronary arteries, comparing with IVUS imaging.

    PubMed

    Park, Jong Kwan; Kim, Jong Youn; Kwon, Hyuck Moon; Kim, Tae Hoon; Oh, Seung-Jin; Hong, Bum-Kee; Yoon, Young Won; Min, Pil-Ki; Kwon, Sung Woo; Lee, Byoung Kwon

    2014-05-01

    Contrast enhanced multidetector computed tomography (MDCT) has been used as an alternative to coronary angiography for the assessment of coronary artery disease in the patient of the intermediate risk group. However, coronary calcium is a known limiting factor for MDCT evaluation. We investigated the diagnostic accuracy of 64-channel MDCT with each coronary artery calcium score (CACS) by compared with intravascular ultrasound (IVUS) imaging. A total of 54 symptomatic patients with intermediate-risk (10 females, mean age 59.9±6.9 years, Framingham point scores 9-20) with 162 sites who had a culprit lesion on 64-channel MDCT before performing coronary angiography with IVUS were enrolled. Patients were divided into 4 subgroups depending on CACS: 0, 1-99, 100-399, and >400. Lesion length, external elastic membrane (EEM) cross sectional area (CSA), minimal luminal area, and plaque area were measured and compared between IVUS and MDCT. The correlation coefficients for the measurements of the EEM CSA, lumen CSA, and plaque area were r=0.514, r=0.837, and r=0.578, respectively. Furthermore, there were close correlation of plaque area between four subgroups of CACS (r=0.671, r=0.623, r=0.562, r=0.571, respectively). Despite the increase in CACS, the geometric analysis of coronary arteries using with 64-channel MDCT was comparable with IVUS in symptomatic patient of the intermediate risk group.

  1. Multidetector Computed Tomography for the Evaluation of Coronary Artery Disease; The Diagnostic Accuracy in Calcified Coronary Arteries, Comparing with IVUS Imaging

    PubMed Central

    Park, Jong Kwan; Kim, Jong Youn; Kwon, Hyuck Moon; Kim, Tae Hoon; Oh, Seung-Jin; Hong, Bum-Kee; Yoon, Young Won; Min, Pil-Ki; Kwon, Sung Woo

    2014-01-01

    Purpose Contrast enhanced multidetector computed tomography (MDCT) has been used as an alternative to coronary angiography for the assessment of coronary artery disease in the patient of the intermediate risk group. However, coronary calcium is a known limiting factor for MDCT evaluation. We investigated the diagnostic accuracy of 64-channel MDCT with each coronary artery calcium score (CACS) by compared with intravascular ultrasound (IVUS) imaging. Materials and Methods A total of 54 symptomatic patients with intermediate-risk (10 females, mean age 59.9±6.9 years, Framingham point scores 9-20) with 162 sites who had a culprit lesion on 64-channel MDCT before performing coronary angiography with IVUS were enrolled. Patients were divided into 4 subgroups depending on CACS: 0, 1-99, 100-399, and >400. Lesion length, external elastic membrane (EEM) cross sectional area (CSA), minimal luminal area, and plaque area were measured and compared between IVUS and MDCT. Results The correlation coefficients for the measurements of the EEM CSA, lumen CSA, and plaque area were r=0.514, r=0.837, and r=0.578, respectively. Furthermore, there were close correlation of plaque area between four subgroups of CACS (r=0.671, r=0.623, r=0.562, r=0.571, respectively). Conclusion Despite the increase in CACS, the geometric analysis of coronary arteries using with 64-channel MDCT was comparable with IVUS in symptomatic patient of the intermediate risk group. PMID:24719125

  2. Intravascular Photoacoustics for Image-Guidance and Temperature Monitoring During Plasmonic Photothermal Therapy of Atherosclerotic Plaques: A Feasibility Study

    PubMed Central

    Yeager, Doug; Chen, Yun-Sheng; Litovsky, Silvio; Emelianov, Stanislav

    2014-01-01

    Recently, combined intravascular ultrasound and photoacoustic (IVUS/IVPA) imaging has been demonstrated as a novel imaging modality capable of visualizing both morphology (via IVUS) and cellular/molecular composition (via IVPA) of atherosclerotic plaques, using both endogenous tissue absorbers and exogenous contrast agents. Plasmonic gold nanoparticles were previously utilized as IVPA contrast agents which co-localize with atherosclerotic plaques, particularly phagocytically active macrophages. The present work demonstrates the use of IVUS/IVPA imaging as a tool for localized temperature monitoring during laser heating. The temperature dependent change in IVPA signal intensity of silica-coated gold nanorod contrast agents absorbing within the near-infrared optical wavelength range is evaluated and shown to have a linear relationship, with a slope greater than that of endogenous tissue. A continuous wave laser was subsequently incorporated into the IVUS/IVPA integrated catheter and utilized to selectively heat the nanoparticles with simultaneous IVPA temperature monitoring. IVUS/IVPA, therefore, provides a platform for detection and temperature monitoring of atherosclerotic plaques through the selective heating of plasmonic gold nanoparticle contrast agents. PMID:24396514

  3. 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

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

    PubMed

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

    2015-06-01

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

  5. Radial Modulation Contrast Imaging Using a 20-MHz Single-Element Intravascular Ultrasound Catheter

    PubMed Central

    Yu, Francois T. H.; Villanueva, Flordeliza S.; Chen, Xucai

    2014-01-01

    Contrast-enhanced intravascular ultrasound imaging is a promising tool for the characterization of coronary vasa vasorum proliferation, which has been identified as a marker of, and possible etiologic factor in, the development of high-risk atherosclerotic plaques. Resonance-based nonlinear detection methods have required the development of prototype catheters which are not commercially available, thus limiting clinical translation. In this study, we investigated the performances of a radial modulation imaging approach (25/3 MHz combination) using simulations, implemented it on a clinical 20-MHz rotating catheter, and tested it in a wall-less tissue-mimicking flow phantom perfused with lipid-encapsulated microbubbles (MBs). The effects of the phase lag, low-frequency pressure, and MB concentration on the envelope subtracted radial modulation signals were investigated as a function of depth. Our dual-pulse dual-frequency approach produced contrast-specific images with contrast-to-tissue improvements over B-mode of 15.1 ± 2.1 dB at 2 mm and 6.8 ± 0.1 dB at 4 mm depths. Using this imaging strategy, 200-μm-diameter cellulose tubing perfused with MBs could be resolved while surrounding tissue scattering was suppressed. These results raise promise for the detection of coronary vasa vasorum and may ultimately facilitate the detection of plaque at risk for rupture. PMID:24803134

  6. Impact of statin therapy on plaque characteristics as assessed by serial OCT, grayscale and integrated backscatter-IVUS.

    PubMed

    Hattori, Kousuke; Ozaki, Yukio; Ismail, Tevfik F; Okumura, Masanori; Naruse, Hiroyuki; Kan, Shino; Ishikawa, Makoto; Kawai, Tomoko; Ohta, Masaya; Kawai, Hideki; Hashimoto, Tousei; Takagi, Yasushi; Ishii, Junichi; Serruys, Patrick W; Narula, Jagat

    2012-02-01

    The purpose of this study was to evaluate the effect of statin treatment on coronary plaque composition and morphology by optical coherence tomography (OCT), grayscale and integrated backscatter (IB) intravascular ultrasound (IVUS) imaging. Although previous studies have demonstrated that statins substantially improve cardiac mortality, their precise effect on the lipid content and fibrous cap thickness of atherosclerotic coronary lesions is less clear. While IVUS lacks the spatial resolution to accurately assess fibrous cap thickness, OCT lacks the penetration of IVUS. We used a combination of OCT, grayscale and IB-IVUS to comprehensively assess the impact of pitavastatin on plaque characteristics. Prospective serial OCT, grayscale and IB-IVUS of nontarget lesions was performed in 42 stable angina patients undergoing elective coronary intervention. Of these, 26 received 4 mg pitavastatin after the baseline study; 16 subjects who refused statin treatment were followed with dietary modification alone. Follow-up imaging was performed after a median interval of 9 months. Grayscale IVUS revealed that in the statin-treated patients, percent plaque volume index was significantly reduced over time (48.5 ± 10.4%, 42.0 ± 11.1%; p = 0.033), whereas no change was observed in the diet-only patients (48.7 ± 10.4%, 50.4 ± 11.8%; p = NS). IB-IVUS identified significant reductions in the percentage lipid volume index over time (34.9 ± 12.2%, 28.2 ± 7.5%; p = 0.020); no change was observed in the diet-treated group (31.0 ± 10.7%, 33.8 ± 12.4%; p = NS). While OCT demonstrated a significant increase in fibrous cap thickness (140 ± 42 μm, 189 ± 46 μm; p = 0.001), such changes were not observed in the diet-only group (140 ± 35 μm, 142 ± 36 μm; p = NS). Differences in the changes in the percentage lipid volume index (-6.8 ± 8.0% vs. 2.8 ± 9.9%, p = 0.031) and fibrous cap thickness (52 ± 32 μm vs. 2 ± 22 μm, p < 0.001) over time between the pitavastatin and diet

  7. Predictors for functionally significant in-stent restenosis: an integrated analysis using coronary angiography, IVUS, and myocardial perfusion imaging.

    PubMed

    Kang, Soo-Jin; Cho, Young-Rak; Park, Gyung-Min; Ahn, Jung-Min; Han, Seung-Bong; Lee, Jong-Young; Kim, Won-Jang; Park, Duk-Woo; Lee, Seung-Whan; Kim, Young-Hak; Lee, Cheol Whan; Park, Seong-Wook; Mintz, Gary S; Park, Seung-Jung

    2013-11-01

    The aim of this study was to assess the clinical and morphological predictors for functionally significant in-stent restenosis (ISR). Although they have been studied de novo in native coronary artery lesions, the relationships between clinical and morphological characteristics and the hemodynamic significance of ISR are not well understood. In 175 patients with ISR of a single coronary artery (angiographic stenosis >50%), we compared quantitative coronary angiography and intravascular ultrasound (IVUS) with stress myocardial single-photon emission computed tomography (SPECT). A positive SPECT was a reversible perfusion defect in the territory of the ISR artery. Overall, 103 (59%) patients had a positive SPECT. In-segment IVUS minimal lumen area (MLA) was significantly smaller in lesions with positive SPECT compared with negative SPECT (1.7 ± 0.5 mm(2) vs. 2.4 ± 0.8 mm(2), p < 0.001). Stent underexpansion (minimal stent area <5.0 mm(2)) was more common in the positive SPECT group than in the negative SPECT group (52% vs. 32%, p = 0.010). A positive SPECT was seen in 54% (65 of 121) of focal ISR lesions compared with 70% (38 of 54) of multifocal or diffuse ISR lesions as assessed by IVUS (p = 0.039). Independent determinants for a positive SPECT were diabetes (odds ratio [OR]: 2.41; 95% confidence interval [CI]: 1.02 to 5.68; p = 0.046), in-segment angiographic diameter stenosis (OR: 1.06; 95% CI: 1.03 to 1.09; p < 0.001), in-segment IVUS-MLA (OR: 0.30; 95% CI: 0.14 to 0.63; p = 0.001), stent underexpansion (minimal stent area <5.0 mm(2)), (OR: 2.91; 95% CI: 1.19 to 7.07; p = 0.019), proximal location of the IVUS-MLA (OR: 4.62; 95% CI: 1.75 to 12.18; p = 0.002), and a multifocal or diffuse ISR pattern (OR: 2.50; 95% CI: 0.99 to 6.28; p = 0.050). An in-segment angiographic diameter stenosis ≥69.5% (72% sensitivity, 74% specificity, area under the curve = 0.793) and an IVUS-MLA ≤1.9 mm(2) (67% sensitivity, 75% specificity, area under the curve = 0.756) best

  8. 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.

  9. Contour detection of atherosclerotic plaques in IVUS images using ellipse template matching and particle swarm optimization.

    PubMed

    Zhang, Qi; Wang, Yuanyuan; Ma, Jianying; Shi, Jun

    2011-01-01

    It is valuable for diagnosis of atherosclerosis to detect lumen and media-adventitia contours in intravascular ultrasound (IVUS) images of atherosclerotic plaques. In this paper, a method for contour detection of plaques is proposed utilizing the prior knowledge of elliptic geometry of plaques. Contours are initialized as ellipses by using ellipse template matching, where a matching function is maximized by particle swarm optimization. Then the contours are refined by boundary vector field snakes. The method was evaluated via 88 in vivo images from 21 patients. It outperformed a state-of-the-art method by 3.8 pixels and 4.8% in terms of the mean distance error and relative mean distance error, respectively.

  10. Interframe registration of IVUS images due to catheter rotation with feature-based optical flow

    NASA Astrophysics Data System (ADS)

    Danilouchkine, Mikhail G.; Mastik, Frits; van der Steen, Antonius F. W.

    2007-03-01

    The quantitative assessment of and compensation for catheter rotation in Intravascular Ultrasound (IVUS) images presents a fundamental problem for noninvasive characterization of the mechanical properties of the coronary arteries. A method based on the scale-space optical flow algorithm with a feature-based weighting scheme is proposed to account for the aforementioned artifact. The computed vector field, describing the transformation between two consecutive frames, allows the quantitative assessment of the amount of vessel wall tissue motion, which is directly related to the catheter rotation. Algorithm accuracy and robustness were demonstrated on a tissue-mimicking phantom, subjected to controlled amount of angular deviation. The proposed method shows a great reliability in prediction of catheter rotational motion up to 4°.

  11. 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

  12. Additive Value of Integrated Backscatter IVUS for Detection of Vulnerable Plaque by Optical Frequency Domain Imaging: An Ex Vivo Autopsy Study of Human Coronary Arteries.

    PubMed

    Nakano, Masataka; Yahagi, Kazuyuki; Yamamoto, Hirosada; Taniwaki, Masanori; Otsuka, Fumiyuki; Ladich, Elena R; Joner, Michael; Virmani, Renu

    2016-02-01

    This study sought to evaluate the diagnostic performance of optical frequency domain imaging (OFDI) for recognition of coronary plaque morphologies and to assess additive values of integrated backscatter intravascular ultrasound (IB-IVUS) in detection of vulnerable plaque. Precise diagnosis of coronary lesions susceptible to plaque rupture and thrombosis may serve to stratify the risk of future coronary events and to make decisions for appropriate treatment of choice. Twenty-seven coronary arteries from 14 human autopsy hearts were interrogated ex vivo by OFDI and IB-IVUS. Imaged segments were sectioned at 3 mm intervals where a total of 360 pairs of cross-sectional images coregistered to histology were investigated. Overall, OFDI could depict various plaque components and structures such as fibrous tissue, sheet and nodular calcification, lipid, cholesterol crystals, and healed plaque rupture. OFDI could detect 14 of 18 thin-cap fibroatheroma (TCFA), however, the diagnostic accuracy was not high (positive predictive value [PPV] = 60.9%, κ = 0.664; area under the curve [AUC]: 0.88) mainly because of signal interference from macrophages. Further, we defined IB-IVUS-derived TCFA by recursive partitioning analysis as: 1) cross-sectional % lipid area >65.1%; 2) % lipid area >32.3 but <65.1% with plaque area >10.5 mm(2), where TCFA detection by IB-IVUS alone was marginal (PPV = 50.0%, κ = 0.545; AUC: 0.82). However, when IB-IVUS was combined with OFDI, all pseudo OFDI-derived TCFA (non-TCFA on histology) were excluded. Accordingly, PPV of TCFAs diagnosed by both OFDI and IB-IVUS was improved to 100.0% (κ = 0.704; AUC: 0.93). OFDI could recognize detailed morphologies of human coronary plaque. However, diagnostic accuracy of both OFDI alone and IB-IVUS alone to identify TCFA is limited. Combination of IB-IVUS with OFDI improved the accuracy for TCFA detection, suggesting hybrid imaging or further development of novel devices will be required to identify

  13. Impact of peri-stent remodeling on restenosis: a volumetric intravascular ultrasound study.

    PubMed

    Nakamura, M; Yock, P G; Bonneau, H N; Kitamura, K; Aizawa, T; Tamai, H; Fitzgerald, P J; Honda, Y

    2001-05-01

    Vessel remodeling is an important mechanism of late lumen loss after nonstent coronary interventions. However, its impact on in-stent restenosis has not been systematically investigated. Serial volumetric intravascular ultrasound analyses (poststent and follow-up) were performed in 55 lesions treated with a balloon-expandable stent (ACS MultiLink) using standard stent deployment techniques. The vessel volume (VV), lumen volume (LV), and volume bordered by the stent (SV) were measured using Simpson's method. The volume of plaque and neointima outside the stent (peri-stent volume, PSV) and volume of neointima within the stent (intrastent volume) were also measured. The change of each parameter during the follow-up period (follow-up minus poststent) was calculated and then divided by SV to normalize these values (designated as percent change [%]). As expected, %PSV directly correlated with %VV (P<0.0001, r=0.935), with no significant SV. A highly significant inverse correlation was seen between %PSV and the percent change of intrastent volume (P<0.0001, r=0.517). Consequently, %LV significantly correlated with peri-stent remodeling, as measured by %VV (P<0.0001, r=0.602). Positive remodeling of the vessel exterior to a coronary stent occurs to a variable degree after stent implantation. There is a distinct trade-off between positive remodeling and in-stent hyperplasia: in segments in which the degree of peri-stent remodeling is less, intrastent neointimal proliferation is greater and accompanied by more significant late lumen loss.

  14. Multimodality Intracoronary Imaging With Near-Infrared Spectroscopy and Intravascular Ultrasound in Asymptomatic Individuals With High Calcium Scores.

    PubMed

    Madder, Ryan D; VanOosterhout, Stacie; Klungle, David; Mulder, Abbey; Elmore, Matthew; Decker, Jeffrey M; Langholz, David; Boyden, Thomas F; Parker, Jessica; Muller, James E

    2017-10-01

    This study sought to determine the frequency of large lipid-rich plaques (LRP) in the coronary arteries of individuals with high coronary artery calcium scores (CACS) and to determine whether the CACS correlates with coronary lipid burden. Combined near-infrared spectroscopy and intravascular ultrasound was performed in 57 vessels in 20 asymptomatic individuals (90% on statins) with no prior history of coronary artery disease who had a screening CACS ≥300 Agatston units. Among 268 10-mm coronary segments, near-infrared spectroscopy images were analyzed for LRP, defined as a bright yellow block on the near-infrared spectroscopy block chemogram. Lipid burden was assessed as the lipid core burden index (LCBI), and large LRP were defined as a maximum LCBI in 4 mm ≥400. Vessel plaque volume was measured by quantitative intravascular ultrasound. Vessel-level CACS significantly correlated with plaque volume by intravascular ultrasound (r=0.69; P<0.0001) but not with LCBI by near-infrared spectroscopy (r=0.24; P=0.07). Despite a high CACS, no LRP was detected in 8 (40.0%) subjects. Large LRP having a maximum LCBI in 4 mm ≥400 were infrequent, found in only 5 (25.0%) of 20 subjects and in only 5 (1.9%) of 268 10-mm coronary segments analyzed. Among individuals with a CACS ≥300 Agatston units mostly on statins, CACS correlated with total plaque volume but not LCBI. This observation may have implications on coronary risk among individuals with a high CACS considering that it is coronary LRP, rather than calcification, that underlies the majority of acute coronary events. © 2017 American Heart Association, Inc.

  15. Five multiresolution-based calcium volume measurement techniques from coronary IVUS videos: A comparative approach.

    PubMed

    Banchhor, Sumit K; Araki, Tadashi; Londhe, Narendra D; Ikeda, Nobutaka; Radeva, Petia; Elbaz, Ayman; Saba, Luca; Nicolaides, Andrew; Shafique, Shoaib; Laird, John R; Suri, Jasjit S

    2016-10-01

    Fast intravascular ultrasound (IVUS) video processing is required for calcium volume computation during the planning phase of percutaneous coronary interventional (PCI) procedures. Nonlinear multiresolution techniques are generally applied to improve the processing time by down-sampling the video frames. This paper presents four different segmentation methods for calcium volume measurement, namely Threshold-based, Fuzzy c-Means (FCM), K-means, and Hidden Markov Random Field (HMRF) embedded with five different kinds of multiresolution techniques (bilinear, bicubic, wavelet, Lanczos, and Gaussian pyramid). This leads to 20 different kinds of combinations. IVUS image data sets consisting of 38,760 IVUS frames taken from 19 patients were collected using 40 MHz IVUS catheter (Atlantis® SR Pro, Boston Scientific®, pullback speed of 0.5 mm/sec.). The performance of these 20 systems is compared with and without multiresolution using the following metrics: (a) computational time; (b) calcium volume; (c) image quality degradation ratio; and (d) quality assessment ratio. Among the four segmentation methods embedded with five kinds of multiresolution techniques, FCM segmentation combined with wavelet-based multiresolution gave the best performance. FCM and wavelet experienced the highest percentage mean improvement in computational time of 77.15% and 74.07%, respectively. Wavelet interpolation experiences the highest mean precision-of-merit (PoM) of 94.06 ± 3.64% and 81.34 ± 16.29% as compared to other multiresolution techniques for volume level and frame level respectively. Wavelet multiresolution technique also experiences the highest Jaccard Index and Dice Similarity of 0.7 and 0.8, respectively. Multiresolution is a nonlinear operation which introduces bias and thus degrades the image. The proposed system also provides a bias correction approach to enrich the system, giving a better mean calcium volume similarity for all the multiresolution

  16. IVUS-Guided Implantation of Bioresorbable Vascular Scaffolds for Very Late Paclitaxel Stent Thrombosis

    PubMed Central

    Lin, Zhe-Zhong; Chang, Wei-Ting; Chiang, Chun-Yen; Chen, Zhih-Cherng; Ku, Po-Ming

    2017-01-01

    Bioresorbable vascular scaffold (BVS) implantation has been shown to be safe in patients with stable coronary disease, and effective against the thrombotic lesion and the in-stent restenosis (ISR) of the drug-eluting stent (DES). BVSs have the advantages of a snow racket concept, positive vessel remodeling, and better conformability compared with DES in acute coronary syndrome (ACS). We report on a young patient with ST-elevation myocardial infarction (STEMI) who presented to our emergency department arising from very late stent thrombosis (VLST) of a 2.5 × 28 mm paclitaxel-eluting stent (Coroflex® Please) three years after its implantation. After the patient was treated with balloon dilation, intravascular ultrasound (IVUS) revealed a short segment of a guide wire outside the DES mesh. Two BVSs were implanted to prevent a DES recoil. Post-scaffold-implantation IVUS showed adequately expanded strut of BVSs. Six months later, optical coherence tomography (OCT) revealed that some segments of the scaffold had been absorbed and that there was no in-scaffold restenosis. The patient had not complained about angina during the out-patient clinic follow-up. This is the first report of successful BVS implantation for a STEMI patient attributable to DES VLST. PMID:28115812

  17. A head-to-head comparison between CT- and IVUS-derived coronary blood flow models.

    PubMed

    Bulant, C A; Blanco, P J; Maso Talou, G D; Bezerra, C Guedes; Lemos, P A; Feijóo, R A

    2017-01-25

    The goal of this work is to compare coronary hemodynamics as predicted by computational blood flow models derived from two imaging modalities: coronary computed tomography angiography (CCTA) and intravascular ultrasound integrated with angiography (IVUS). Criteria to define boundary conditions are proposed to overcome the dissimilar anatomical definition delivered by both modalities. The strategy to define boundary conditions is novel in the present context, and naturally accounts for the flow redistribution induced by the resistance of coronary vessels. Hyperemic conditions are assumed to assess model predictions under stressed hemodynamic environments similar to those encountered in Fractional Flow Reserve (FFR) calculations. As results, it was found that CCTA models predict larger pressure drops, higher average blood velocity and smaller FFR. Concerning the flow rate at distal locations in the major vessels of interest, it was found that CCTA predicted smaller flow than IVUS, which is a consequence of a larger sensitivity of CCTA models to coronary steal phenomena. Comparisons to in-vivo measurements of FFR are shown. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Quantification of cross-sectional artery wall motion with IVUS image registration

    NASA Astrophysics Data System (ADS)

    Oakeson, Kevin D.; Zhu, Hui; Friedman, Morton H.

    2004-04-01

    Atherosclerotic lesions have been shown to have different mechanical properties than the non-diseased artery. Calculating vessel wall strain from cross-sectional vessel wall motions allows for the measurement of local stiffness. In this paper, a robust method is developed to track cross-sectional displacements of an artery wall using two different intravascular ultrasound (IVUS) images acquired at two different pressure levels respectively. First, the vessel wall region in one image is segmented semi-automatically by refining two spline-based contours to the locations of inner and outer vessel wall borders. Then the ringlike wall region in one image is registered to its counterpart in the other image in polar coordinates. The registration is performed by minimizing an energy function of the 2D motion field based on a spline-deformable-model. Both intensity and gradient information of the images are used to construct the energy function so that an accurate registration can be achieved. Registration accuracy was tested on simulated motions using IVUS images of a human coronary artery and a porcine carotid. The wall displacement fields calculated from real motion images are also demonstrated.

  19. Quantify patient-specific coronary material property and its impact on stress/strain calculations using in vivo IVUS data and 3D FSI models: a pilot study.

    PubMed

    Guo, Xiaoya; Zhu, Jian; Maehara, Akiko; Monoly, David; Samady, Habib; Wang, Liang; Billiar, Kristen L; Zheng, Jie; Yang, Chun; Mintz, Gary S; Giddens, Don P; Tang, Dalin

    2017-02-01

    Computational models have been used to calculate plaque stress and strain for plaque progression and rupture investigations. An intravascular ultrasound (IVUS)-based modeling approach is proposed to quantify in vivo vessel material properties for more accurate stress/strain calculations. In vivo Cine IVUS and VH-IVUS coronary plaque data were acquired from one patient with informed consent obtained. Cine IVUS data and 3D thin-slice models with axial stretch were used to determine patient-specific vessel material properties. Twenty full 3D fluid-structure interaction models with ex vivo and in vivo material properties and various axial and circumferential shrink combinations were constructed to investigate the material stiffness impact on stress/strain calculations. The approximate circumferential Young's modulus over stretch ratio interval [1.0, 1.1] for an ex vivo human plaque sample and two slices (S6 and S18) from our IVUS data were 1631, 641, and 346 kPa, respectively. Average lumen stress/strain values from models using ex vivo, S6 and S18 materials with 5 % axial shrink and proper circumferential shrink were 72.76, 81.37, 101.84 kPa and 0.0668, 0.1046, and 0.1489, respectively. The average cap strain values from S18 material models were 150-180 % higher than those from the ex vivo material models. The corresponding percentages for the average cap stress values were 50-75 %. Dropping axial and circumferential shrink consideration led to stress and strain over-estimations. In vivo vessel material properties may be considerably softer than those from ex vivo data. Material stiffness variations may cause 50-75 % stress and 150-180 % strain variations.

  20. High speed intravascular photoacoustic imaging with fast optical parametric oscillator laser at 1.7 μm

    PubMed Central

    Piao, Zhonglie; Ma, Teng; Li, Jiawen; Wiedmann, Maximilian T.; Huang, Shenghai; Yu, Mingyue; Kirk Shung, K.; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2015-01-01

    Intravascular photoacoustic imaging at 1.7 μm spectral band has shown promising capabilities for lipid-rich vulnerable atherosclerotic plaque detection. In this work, we report a high speed catheter-based integrated intravascular photoacoustic/intravascular ultrasound (IVPA/IVUS) imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A lipid-mimicking phantom and atherosclerotic rabbit abdominal aorta were imaged at 1 frame per second, which is two orders of magnitude faster than previously reported in IVPA imaging with the same wavelength. Clear photoacoustic signals by the absorption of lipid rich deposition demonstrated the ability of the system for high speed vulnerable atherosclerotic plaques detection. PMID:26339072

  1. High speed intravascular photoacoustic imaging with fast optical parametric oscillator laser at 1.7 μm.

    PubMed

    Piao, Zhonglie; Ma, Teng; Li, Jiawen; Wiedmann, Maximilian T; Huang, Shenghai; Yu, Mingyue; Kirk Shung, K; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2015-08-24

    Intravascular photoacoustic imaging at 1.7 μm spectral band has shown promising capabilities for lipid-rich vulnerable atherosclerotic plaque detection. In this work, we report a high speed catheter-based integrated intravascular photoacoustic/intravascular ultrasound (IVPA/IVUS) imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A lipid-mimicking phantom and atherosclerotic rabbit abdominal aorta were imaged at 1 frame per second, which is two orders of magnitude faster than previously reported in IVPA imaging with the same wavelength. Clear photoacoustic signals by the absorption of lipid rich deposition demonstrated the ability of the system for high speed vulnerable atherosclerotic plaques detection.

  2. High speed intravascular photoacoustic imaging with fast optical parametric oscillator laser at 1.7 μm

    NASA Astrophysics Data System (ADS)

    Piao, Zhonglie; Ma, Teng; Li, Jiawen; Wiedmann, Maximilian T.; Huang, Shenghai; Yu, Mingyue; Kirk Shung, K.; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2015-08-01

    Intravascular photoacoustic imaging at 1.7 μm spectral band has shown promising capabilities for lipid-rich vulnerable atherosclerotic plaque detection. In this work, we report a high speed catheter-based integrated intravascular photoacoustic/intravascular ultrasound (IVPA/IVUS) imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A lipid-mimicking phantom and atherosclerotic rabbit abdominal aorta were imaged at 1 frame per second, which is two orders of magnitude faster than previously reported in IVPA imaging with the same wavelength. Clear photoacoustic signals by the absorption of lipid rich deposition demonstrated the ability of the system for high speed vulnerable atherosclerotic plaques detection.

  3. PCSK9 in relation to coronary plaque inflammation: Results of the ATHEROREMO-IVUS study.

    PubMed

    Cheng, Jin M; Oemrawsingh, Rohit M; Garcia-Garcia, Hector M; Boersma, Eric; van Geuns, Robert-Jan; Serruys, Patrick W; Kardys, Isabella; Akkerhuis, K Martijn

    2016-05-01

    Experimental studies have suggested that proprotein convertase substilisin/kexin type 9 (PCSK9) might directly promote inflammatory processes contributing to atherosclerosis by mechanisms independent of low-density lipoprotein (LDL) cholesterol levels. This study aims to investigate the association between serum PCSK9 levels and the fraction and amount of necrotic core tissue in coronary atherosclerotic plaque, as assessed by intravascular ultrasound virtual histology (IVUS-VH) imaging. Between 2008 and 2011, IVUS-VH imaging of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography for acute coronary syndrome (ACS) or stable angina. PCSK9 concentrations were measured in serum samples that were drawn prior to coronary angiography. None of the patients received PCSK9 inhibitors. After adjustment for established cardiac risk factors, statin use and serum LDL cholesterol, serum PCSK9 levels were linearly associated with the fraction of plaque consisting of necrotic core tissue (β = 1.24% increase per 100 μg/L increase in PCKS9, 95%CI 0.55-1.94, p = 0.001) and with the absolute volume of necrotic core tissue (β = 0.09, 95%CI 0.01-0.18, p = 0.033), but were not significantly associated with plaque burden (p = 0.11), plaque volume (p = 0.22) or the presence of IVUS-VH-derived thin-cap fibroatheroma lesions (p = 1.0). Serum PCSK9 levels were linearly associated with the fraction and amount of necrotic core tissue in coronary atherosclerosis, independently of serum LDL cholesterol levels and statin use. Therefore, PCSK9 may be an interesting therapeutic target for the treatment of atherosclerotic disease beyond LDL cholesterol regulation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Bioresorbable vascular scaffolds for LMCA with double vessel disease under IVUS guidance.

    PubMed

    Kasturi, Sridhar; Vilvanathan, Vinoth Kumar

    2015-12-01

    An 80-year-old male patient, presented with chest pain. ECG showed ST elevation in leads V2 to V4 and T wave inversion in leads V2-V6. Check angiogram revealed ostial LMCA 70% lesion & mid-LAD 90% lesion and LCX proximal 80% lesion. Predilatation of LMCA lesion was done with 2.0 × 12 mm NC Trek balloon and the LAD lesion with 2.0 × 12 mm and 2.5 × 08 mm (NC Trek balloons). Prestenting IVUS (Intravascular ultrasound) was done with Atlantis SR pro 40 MHz 3.6 Fr catheter. IVUS showed the LAD to have a minimal lumen area of 2.6 sq mm with 90% fibrotic plaque and a vessel size of 2.5mm and the LMCA to have a minimal lumen area of 8.8 sq mm with 70% fibrotic plaque and vessel size of 3.8mm. Mid-LAD stenting was done with 2.5 × 28 mm Absorb Stent (BVS). Predilatation of LCX lesion was done with 2.5 × 08 mm NC Trek balloon. Then stenting was performed with 3.0 × 28 mm Absorb Stent (BVS). Check angiogram showed edge dissection proximal to the BVS Stent which was covered with 3.0 × 12 mm Xience Xpedtion Stent (DES). Then LMCA Stenting was done with 3.5 × 12 mm Absorb Stent. Post dilatation was done with 4.0 × 08 mm NC Trek balloon. Post Stenting LMCA - LAD IVUS was done. LMCA and LAD Stents were well opposed without any dissection or residual stenosis. TIMI III Flow was achieved in the final results. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  5. A Case of Acute Myocardial Infarction due to Left Main Trunk Occlusion Complicated With Aortic Dissection as Diagnosed by Intravascular Ultrasound

    PubMed Central

    Okamoto, Masashi; Amano, Tomonori; Matsuoka, Shunzo; Hirai, Hideki; Masuda, Kazunori; Nakajima, Kanta; Sueyoshi, Atsushi

    2012-01-01

    A 52-year-old man was transferred to our hospital with a sudden onset of severe chest pains. His electrocardiogram revealed ST-segment elevation suggestive of acute myocardial infarction. Emergency coronary angiography showed subtotal occlusion of left main trunk (LMT) with delayed coronary flow. Because intravascular ultrasound revealed a large intimal flap, we diagnosed aortic dissection involving the LMT. After stenting of the LMT, the patient underwent surgical repair of the aortic dissection. Although it is difficult to obtain a correct diagnosis of aortic dissection complicated with myocardial ischemia, we succeeded in diagnosing this rare condition by use of a intravascular ultrasound.

  6. Serial Assessment of Tissue Precursors and Progression of Coronary Calcification Analyzed by Fusion of IVUS and OCT: 5-Year Follow-Up of Scaffolded and Nonscaffolded Arteries.

    PubMed

    Zeng, Yaping; Tateishi, Hiroki; Cavalcante, Rafael; Tenekecioglu, Erhan; Suwannasom, Pannipa; Sotomi, Yohei; Collet, Carlos; Nie, Shaoping; Jonker, Hans; Dijkstra, Jouke; Radu, Maria D; Räber, Lorenz; McClean, Dougal R; van Geuns, Robert-Jan; Christiansen, Evald H; Fahrni, Therese; Koolen, Jacques; Onuma, Yoshinobu; Bruining, Nico; Serruys, Patrick W

    2017-10-01

    The aim of this study was to assess calcium growth with fused grayscale intravascular ultrasound (IVUS), IVUS-virtual histology, and optical coherence tomography (OCT) from baseline to 5-year follow-up in patients treated with bioresorbable vascular scaffolds. IVUS and OCT have individual strengths in assessing plaque composition and volume. Fusion of images obtained using these methods could potentially aid in coronary plaque assessment. Anatomic landmarks and endoluminal radiopaque markers were used to fuse OCT and IVUS images and match baseline and follow-up. Seventy-two IVUS-virtual histology and OCT paired matched cross-sectional in- and out-scaffold segments were fused at baseline and follow-up. In total, 46 calcified plaques at follow-up were detected using the fusion method (33 in-scaffold, 13 out-scaffold), showing either calcium progression (52.2%) or de novo calcifications (47.8%). On OCT, calcification volume increased from baseline to follow-up by 2.3 ± 2.4 mm(3) (p = 0.001). The baseline virtual histologic tissue precursors of dense calcium at follow-up were necrotic core in 73.9% and fibrous or fibrofatty plaque in 10.9%. In 15.2%, calcium was already present at baseline. Precursors on OCT were lipid pool in 71.2%, fibrous plaque in 4.3%, and fibrocalcific plaque in 23.9%. The use of OCT and IVUS fusion imaging shows similar calcium growth in- and out-scaffold segments. Necrotic core is the most frequent precursor of calcification. The scaffold resorption process creates a tissue layer that re-caps the calcified plaques. (Absorb Clinical Investigation, Cohort B [ABSORB B]; NCT00856856). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  7. Integrated intravascular ultrasound and optical coherence tomography technology: a promising tool to identify vulnerable plaques [INVITED PAPER

    PubMed Central

    Li, Jiawen; Chen, Zhongping

    2017-01-01

    Heart attack is mainly caused by the rupture of a vulnerable plaque. IVUS-OCT is a novel medical imaging modality that provides opportunities for accurate assessment of vulnerable plaques in vivo in patients. IVUS provides deep penetration to image the whole necrotic core while OCT enables accurate measurement of the fibrous cap of a plaque owing to its high resolution. In this paper, the authors describe the fundamentals, the technical designs and the applications of IVUS-OCT technology. Results from cadaver specimens are summarized, which indicated the complementary nature of OCT and IVUS for assessment of vulnerable plaques, plaque composition, and stent-tissue interactions. Furthermore, previously reported in vivo animal experiments are reviewed to assess the clinical adaptability of IVUS-OCT. Future directions for this technology are also discussed in this review. PMID:28966987

  8. Reconstruction of Intima and Adventitia Models into a State Undeformed by a Catheter by Using CT, IVUS, and Biplane X-Ray Angiogram Images

    PubMed Central

    Son, Jinwon

    2017-01-01

    The number of studies on blood flow analysis using fluid-structure interaction (FSI) analysis is increasing. Though a 3D blood vessel model that includes intima and adventitia is required for FSI analysis, there are difficulties in generating it using only one type of medical imaging. In this paper, we propose a 3D modeling method for accurate FSI analysis. An intravascular ultrasound (IVUS) image is used with biplane X-ray angiogram images to calculate the position and orientation of the blood vessel. However, these images show that the blood vessel is deformed by the catheter inserted into the blood vessel for IVUS imaging. To eliminate such deformation, a CT image was added and the two models were registered. First, a 3D model of the undeformed intima was generated using a CT image. In the second stage, a model of intima and adventitia deformed by the catheter was generated by combining the IVUS image and the X-ray angiogram images. A 3D model of intima and adventitia with the deformation caused by insertion of the catheter eliminated was generated by matching these 3D blood vessel models in different states. In addition, a 3D blood vessel model including bifurcation was generated using the proposed method. PMID:28154609

  9. Reconstruction of Intima and Adventitia Models into a State Undeformed by a Catheter by Using CT, IVUS, and Biplane X-Ray Angiogram Images.

    PubMed

    Son, Jinwon; Choi, Young

    2017-01-01

    The number of studies on blood flow analysis using fluid-structure interaction (FSI) analysis is increasing. Though a 3D blood vessel model that includes intima and adventitia is required for FSI analysis, there are difficulties in generating it using only one type of medical imaging. In this paper, we propose a 3D modeling method for accurate FSI analysis. An intravascular ultrasound (IVUS) image is used with biplane X-ray angiogram images to calculate the position and orientation of the blood vessel. However, these images show that the blood vessel is deformed by the catheter inserted into the blood vessel for IVUS imaging. To eliminate such deformation, a CT image was added and the two models were registered. First, a 3D model of the undeformed intima was generated using a CT image. In the second stage, a model of intima and adventitia deformed by the catheter was generated by combining the IVUS image and the X-ray angiogram images. A 3D model of intima and adventitia with the deformation caused by insertion of the catheter eliminated was generated by matching these 3D blood vessel models in different states. In addition, a 3D blood vessel model including bifurcation was generated using the proposed method.

  10. Iatrogenic subtle acute aortic dissection during coronary angioplasty for in-stent restenosis. Value of intravascular ultrasound for diagnosis and management.

    PubMed

    Alfonso, Fernando; Alvarez, Lucia; Almeria, Carlos

    2004-09-01

    A patient with a subtle, iatrogenic, type A aortic dissection following a coronary angioplasty is described. Intravascular ultrasound was useful to confirm the diagnosis of the confined aortic dissection and also to guide adequate stent coverage of its coronary entry door. Both transesophageal echocardiography and magnetic resonance imaging failed to detect any significant aortic wall abnormality.

  11. 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

  12. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. 3-D ultrasound imaging using a forward-looking CMUT ring array for intravascular/intracardiac applications.

    PubMed

    Yeh, David T; Oralkan, Omer; Wygant, Ira O; O'Donnell, Matthew; Khuri-Yakub, Butrus T

    2006-06-01

    Forward-viewing ring arrays can enable new applications in intravascular and intracardiac ultrasound. This work presents compelling, full-synthetic, phased-array volumetric images from a forward-viewing capacitive micromachined ultrasonic transducer (CMUT) ring array wire bonded to a custom integrated circuit front end. The CMUT ring array has a diameter of 2 mm and 64 elements each 100 microm x 100 microm in size. In conventional mode, echo signals received from a plane reflector at 5 mm had 70% fractional bandwidth around a center frequency of 8.3 MHz. In collapse mode, 69% fractional bandwidth is measured around 19 MHz. Measured signal-to-noise ratio (SNR) of the echo averaged 16 times was 29 dB for conventional operation and 35 dB for collapse mode. B-scans were generated of a target consisting of steel wires 0.3 mm in diameter to determine resolution performance. The 6 dB axial and lateral resolutions for the B-scan of the wire target are 189 microm and 0.112 radians for 8 MHz, and 78 microm and 0.051 radians for 19 MHz. A reduced firing set suitable for real-time, intravascular applications was generated and shown to produce acceptable images. Rendered three-dimensional (3-D) images of a Palmaz-Schatz stent also are shown, demonstrating that the imaging quality is sufficient for practical applications.

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

    PubMed

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

    2017-02-01

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

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

    PubMed Central

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

    2017-01-01

    We present a tri-modality imaging system and fully integrated tri-modality probe for intravascular imaging. The tri-modality imaging system is able to simultaneously acquire optical coherence tomography (OCT), ultrasound (US), and fluorescence imaging. Moreover, for fluorescence imaging, we used the FDA-approved indocyanine green (ICG) dye as the contrast agent to target lipid-loaded macrophages. We conducted imaging from a male New Zealand white rabbit to evaluate the performance of the tri-modality system. In addition, tri-modality images of rabbit aortas were correlated with hematoxylin and eosin (H&E) histology to check the measurement accuracy. The fully integrated miniature tri-modality probe, together with the use of ICG dye suggest that the system is of great potential for providing a more accurate assessment of vulnerable plaques in clinical applications. PMID:28271001

  16. Graph-Based IVUS Segmentation with Efficient Computer-Aided Refinement

    PubMed Central

    Sun, Shanhui; Sonka, Milan; Beichel, Reinhard R.

    2013-01-01

    A new graph-based approach for segmentation of luminal and external elastic lamina (EEL) surface of coronary vessels in gated 20 MHz intravascular ultrasound (IVUS) image sequences (volumes) is presented. The approach consists of a fully automated segmentation stage (‘new automated’ or NA) and a user-guided computer-aided refinement (‘new refinement’ or NR) stage. Both approaches are based on the LOGISMOS approach for simultaneous dual-surface graph-based segmentation. This combination allows the user to efficiently combine general information about IVUS image appearance and case-specific IVUS morphology and therefore deal with frequently occurring issues like calcified plaque – causing signal shadowing – and imaging artifacts. The automated segmentation stage starts with pre-segmenting the lumen to automatically define the lumen centerline, which is used to transform the segmentation task into a LOGISMOS-family graph optimization problem. Following the automated segmentation, the user can inspect the result and correct local or regional segmentation inaccuracies by (iteratively) providing approximate clues regarding the location of the desired surface locations. This expert information is utilized to modify the previously calculated cost functions, locally reoptimizing the underlying modified graph without a need to start the new optimization from scratch. Validation of our method was performed on 41 gated 20 MHz IVUS data sets for which an expert-defined independent standard was available. Resulting from the automated stage of the approach (NA), the mean and standard deviation of the RMS area errors for the luminal and external elastic lamina surfaces were 1.12 ± 0.67 mm2 and 2.35 ± 1.61 mm2, respectively. Following the refinement stage (NR), the RMS area errors significantly decreased to 0.82±0.44 mm2 and 1.17±0.65 mm2 for the same surfaces, respectively (p < 0.001 for both surfaces). The approach is delivering a previously unachievable speed of

  17. Graph-based IVUS segmentation with efficient computer-aided refinement.

    PubMed

    Sun, Shanhui; Sonka, Milan; Beichel, Reinhard R

    2013-08-01

    A new graph-based approach for segmentation of luminal and external elastic lamina (EEL) surface of coronary vessels in gated 20 MHz intravascular ultrasound (IVUS) image sequences (volumes) is presented. The approach consists of a fully automated segmentation stage ("new automated" or NA) and a user-guided computer-aided refinement ("new refinement" or NR) stage. Both approaches are based on the LOGISMOS approach for simultaneous dual-surface graph-based segmentation. This combination allows the user to efficiently combine general information about IVUS image appearance and case-specific IVUS morphology and therefore deal with frequently occurring issues like calcified plaque-causing signal shadowing-and imaging artifacts. The automated segmentation stage starts with pre-segmenting the lumen to automatically define the lumen centerline, which is used to transform the segmentation task into a LOGISMOS-family graph optimization problem. Following the automated segmentation, the user can inspect the result and correct local or regional segmentation inaccuracies by (iteratively) providing approximate clues regarding the location of the desired surface locations. This expert information is utilized to modify the previously calculated cost functions, locally re-optimizing the underlying modified graph without a need to start the new optimization from scratch. Validation of our method was performed on 41 gated 20 MHz IVUS data sets for which an expert-defined independent standard was available. Resulting from the automated stage of the approach (NA), the mean and standard deviation of the root mean square area errors for the luminal and external elastic lamina surfaces were 1.12 ±0.67 mm (2) and 2.35 ±1.61 mm (2) , respectively. Following the refinement stage (NR), the root mean square area errors significantly decreased to 0.82 ±0.44 mm (2) and 1.17 ±0.65 mm (2) for the same surfaces, respectively ( for both surfaces). The approach is delivering a previously

  18. Pathologic Intimal Thickening Plaque Phenotype: Not as Innocent as Previously Thought. A Serial 3D Intravascular Ultrasound Virtual Histology Study.

    PubMed

    Kovarnik, Tomas; Chen, Zhi; Wahle, Andreas; Zhang, Ling; Skalicka, Hana; Kral, Ales; Lopez, John J; Horak, Jan; Sonka, Milan; Linhart, Ales

    2017-01-01

    Pathologic intimal thickening (PIT) has been considered a benign plaque phenotype. We report plaque phenotypic changes in a baseline/follow-up intravascular ultrasound-based virtual histology study. A total of 61 patients with stable coronary artery disease were analyzed from the HEAVEN trial (89 patients randomized between routine statin therapy vs atorvastatin 80mg and ezetimibe 10mg) with serial intravascular ultrasound imaging of nonculprit vessels. We compared changes in 693 baseline and follow-up 5-mm long segments in a novel risk score, Liverpool Active Plaque Score (LAPS), plaque parameters, and plaque composition. The PIT showed the highest increase of risk score and, with fibrous plaque, also the LAPS. Necrotic core (NC) abutting to the lumen increased in PIT (22 ± 51.7; P = .0001) and in fibrous plaque (17.9 ± 42.6; P = .004) but decreased in thin cap fibroatheroma (TCFA) (⿿15.14 ± 52.2; P = .001). The PIT was the most likely of all nonthin cap fibroatheroma plaque types to transform into TCFA at follow-up (11% of all TCFA found during follow-up and 35.9% of newly-developed TCFA), but showed (together with fibrous plaque) the lowest stability during lipid-lowering therapy (24.7% of PIT remained PIT and 24.5% of fibrous plaque remained fibrous plaque). Over the 1-year follow-up, PIT was the most dynamic of the plaque phenotypes and was associated with an increase of risk score and LAPS (together with fibrous plaque), NC percentage (together with fibrous plaque) and NC abutting to the lumen, despite a small reduction of plaque volume during lipid-lowering therapy. The PIT was the main source for new TCFA segments. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

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

    PubMed

    Kiemeneij, F; Laarman, G; Slagboom, T

    1995-04-01

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

  20. Comparative assessment of "plaque/media" change on three modalities of IVUS immediately after implantation of either everolimus-eluting bioresorbable vascular scaffold or everolimus-eluting metallic stent in Absorb II study.

    PubMed

    Zeng, Yaping; Cavalcante, Rafael; Tenekecioglu, Erhan; Suwannasom, Pannipa; Sotomi, Yohei; Collet, Carlos; Abdelghani, Mahammad; Jonker, Hans; Digne, Franck; Horstkotte, Dieter; Zehender, Manfred; Indolfi, Ciro; Saia, Francesco; Fiorilli, Rosario; Chevalier, Bernard; Bolognese, Leonardo; Goicolea, Javier; Nie, Shaoping; Onuma, Yoshinobu; Serruys, Patrick W

    2017-04-01

    The purpose of the study to assess the comparability of immediate changes in plaque/media volume (PV) on three modalities of intravascular ultrasound (IVUS) after implantation of either bioresorbable vascular scaffold (BVS) or everolimus-eluting metallic stent (EES) in Absorb II Study. The two devices have different device volume and ultrasound backscattering that may interfere with the "plaque/media" assessed by three modalities on IVUS: grayscale, backscattering of radiofrequency and brightness function. In a multicenter randomized controlled trial, 501 patients with stable or unstable angina underwent documentary IVUS pre- and post- implantation. The change in plaque/media volume (PV) was categorized into three groups according to the relative PV change in device segment: PV "increased" >+5% (PVI), PV unchanged ±5% (PVU), and PV decreased <-5% (PVD). The change in PV was re-evaluated three times: after subtraction of theoretical device volume, after analysis of echogenicity based on brightness function. In 449 patients, 483 lesions were analyzed pre- and post-implantation. "PVI" was more frequently observed in BVS (53.8%) than EES group (39.4%), p = 0.006. After subtraction of the theoretical device volume, the frequency of "PVI" decreased in both BVS (36.2%) and EES (32.1%) groups and became comparable (p = 0.581). In addition, the percentage of "PVI" was further reduced in both device groups after correction for either radiofrequency backscattering (BVS 34.4% vs. EES 22.6%) or echogenicity (BVS 25.2% vs. EES 9.7%). PV change in device segment was differently affected by BVS and EES devices implantation due to their differences in device volume and ultrasound backscattering. It implies that the lumen volume was also artifactually affected by the type of device implanted. Comparative IVUS assessment of lumen and plaque/media volume changes following implantation of BVS and EES requires specific methodological adjustment.

  1. Plasma concentrations of molecular lipid species in relation to coronary plaque characteristics and cardiovascular outcome: Results of the ATHEROREMO-IVUS study.

    PubMed

    Cheng, Jin M; Suoniemi, Matti; Kardys, Isabella; Vihervaara, Terhi; de Boer, Sanneke P M; Akkerhuis, K Martijn; Sysi-Aho, Marko; Ekroos, Kim; Garcia-Garcia, Hector M; Oemrawsingh, Rohit M; Regar, Evelyn; Koenig, Wolfgang; Serruys, Patrick W; van Geuns, Robert-Jan; Boersma, Eric; Laaksonen, Reijo

    2015-12-01

    Previous lipidomics analyses have demonstrated that several lipid molecules in plasma are associated with fatal outcome in patients with coronary artery disease (CAD). This study aims to investigate the associations of previously identified high risk lipid molecules in plasma with coronary plaque characteristics derived from intravascular ultrasound virtual histology (IVUS-VH) imaging, with coronary lipid core burden index (LCBI) on near-infrared spectroscopy (NIRS), and with one year cardiovascular outcome in patients with CAD. Between 2008 and 2011, IVUS-VH imaging of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography for acute coronary syndrome (ACS) or stable CAD. NIRS imaging was additionally performed in 191 patients. Plasma concentrations of molecular lipids were measured with mass spectrometry. Several cholesteryl ester, ceramide and lactosylceramide species and ceramide ratios were associated with vulnerable plaque characteristics on IVUS-VH and NIRS imaging and with 1-year major adverse cardiac events (MACE, defined as all-cause mortality, ACS and unplanned coronary revascularization). In particular, ceramide d18:1/16:0 was consistently associated with higher necrotic core fraction on IVUS-VH (p = 0.001), higher LCBI (p = 0.024) on NIRS and higher MACE rate (adjusted HR 1.79 per standard deviation increase in log-transformed lipid concentration, 95%CI 1.24-2.59, p = 0.002). Several molecular lipid species, and particularly ceramide(d18:1/16:0), are associated with the fraction of necrotic core tissue and lipid core burden in coronary atherosclerosis, and are predictive for 1-year clinical outcome after coronary angiography. These molecular lipids may improve risk stratification in CAD and may also be interesting therapeutic targets for the treatment of atherosclerotic disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Validating Intravascular Imaging with Serial Optical Coherence Tomography and Confocal Fluorescence Microscopy

    PubMed Central

    Tardif, Pier-Luc; Bertrand, Marie-Jeanne; Abran, Maxime; Castonguay, Alexandre; Lefebvre, Joël; Stähli, Barbara E.; Merlet, Nolwenn; Mihalache-Avram, Teodora; Geoffroy, Pascale; Mecteau, Mélanie; Busseuil, David; Ni, Feng; Abulrob, Abedelnasser; Rhéaume, Éric; L’Allier, Philippe; Tardif, Jean-Claude; Lesage, Frédéric

    2016-01-01

    Atherosclerotic cardiovascular diseases are characterized by the formation of a plaque in the arterial wall. Intravascular ultrasound (IVUS) provides high-resolution images allowing delineation of atherosclerotic plaques. When combined with near infrared fluorescence (NIRF), the plaque can also be studied at a molecular level with a large variety of biomarkers. In this work, we present a system enabling automated volumetric histology imaging of excised aortas that can spatially correlate results with combined IVUS/NIRF imaging of lipid-rich atheroma in cholesterol-fed rabbits. Pullbacks in the rabbit aortas were performed with a dual modality IVUS/NIRF catheter developed by our group. Ex vivo three-dimensional (3D) histology was performed combining optical coherence tomography (OCT) and confocal fluorescence microscopy, providing high-resolution anatomical and molecular information, respectively, to validate in vivo findings. The microscope was combined with a serial slicer allowing for the imaging of the whole vessel automatically. Colocalization of in vivo and ex vivo results is demonstrated. Slices can then be recovered to be tested in conventional histology. PMID:27983695

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Endovascular Surgery for Inflammatory Abdominal Aortic Aneurysm with Contrast Allergy—Usefulness of Carbon Dioxide Angiography and Intravascular Ultrasound: A Case Report

    PubMed Central

    Morito, Haruna; Hoshina, Katsuyuki; Hosaka, Akihiro; Okamoto, Hiroyuki; Shigematsu, Kunihiro; Miyata,, Tetsuro

    2012-01-01

    We report a patient with inflammatory abdominal aortic aneurysm who underwent endovascular aneurysm repair, despite his having an allergy to iodinated contrast medium and anatomy unsuitable for the procedure. Intravascular ultrasound-guided and CO2-assisted aortic stent graft placement was performed, and the procedures resulted in the successful exclusion of the aneurysm with regression of the mantle sign and resolution of hydronephrosis. PMID:23555498

  8. 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

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

    PubMed

    Kwon, Jee Eun; Lee, Wang Soo; 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

    2016-07-01

    We assessed plaque erosion of culprit lesions in patients with acute coronary syndrome in real world practice. 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. 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). 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.

  10. The distribution of calcified nodule and plaque rupture in patients with peripheral artery disease: an intravascular ultrasound analysis.

    PubMed

    Horimatsu, Tetsuo; Fujii, Kenichi; Fukunaga, Masashi; Miki, Kojiro; Nishimura, Machiko; Naito, Yoshiro; Shibuya, Masahiko; Imanaka, Takahiro; Kawai, Kenji; Tamaru, Hiroto; Sumiyoshi, Akinori; Saita, Ten; Masuyama, Tohru; Ishihara, Masaharu

    2017-05-02

    In addition to plaque rupture (PR), calcified nodule (CN) may also have the potential to develop into arterial thrombus in the peripheral arteries. This study evaluated the distribution of plaque ruptures and calcified nodules in the peripheral arteries and their impact on the outcome of endovascular therapy (EVT). Consecutive 159 patients who underwent EVT with intravascular ultrasound guidance were enrolled. The position of CNs and PRs were assigned to any of common iliac artery, external iliac artery, common femoral artery, and superficial femoral artery. Forty-six (29%) patients had calcified nodule and twenty-eight (18%) patients had plaque rupture somewhere in the lower limb arteries. Although calcified nodules were evenly distributed throughout the length of the arteries plaque ruptures were predominantly located in the proximal segment of the iliofemoral arteries. Stent expansion ratio was significantly smaller in the target arteries with calcified nodules than in those with plaque rupture. Multivariate logistic regression analysis identified hemodialysis as an independent clinical predictor of calcified nodule (odds ratio 8.15, 95% confidence interval 1.73-38.3; P = 0.008). CN definitely affects incomplete stent deployment in the peripheral artery contributing to adverse events, on the other hand, PR has more acceptable outcomes after stent implantation. In the clinical setting, it is important that we realize the features of peripheral artery disease and its patient characteristics which having CNs and PRs to make a strategy for revascularization.

  11. Real-time intravascular photoacoustic-ultrasound imaging of lipid-laden plaque at speed of video-rate level

    NASA Astrophysics Data System (ADS)

    Hui, Jie; Cao, Yingchun; Zhang, Yi; Kole, Ayeeshik; Wang, Pu; Yu, Guangli; Eakins, Gregory; Sturek, Michael; Chen, Weibiao; Cheng, Ji-Xin

    2017-03-01

    Intravascular photoacoustic-ultrasound (IVPA-US) imaging is an emerging hybrid modality for the detection of lipidladen plaques by providing simultaneous morphological and lipid-specific chemical information of an artery wall. The clinical utility of IVPA-US technology requires real-time imaging and display at speed of video-rate level. Here, we demonstrate a compact and portable IVPA-US system capable of imaging at up to 25 frames per second in real-time display mode. This unprecedented imaging speed was achieved by concurrent innovations in excitation laser source, rotary joint assembly, 1 mm IVPA-US catheter, differentiated A-line strategy, and real-time image processing and display algorithms. By imaging pulsatile motion at different imaging speeds, 16 frames per second was deemed to be adequate to suppress motion artifacts from cardiac pulsation for in vivo applications. Our lateral resolution results further verified the number of A-lines used for a cross-sectional IVPA image reconstruction. The translational capability of this system for the detection of lipid-laden plaques was validated by ex vivo imaging of an atherosclerotic human coronary artery at 16 frames per second, which showed strong correlation to gold-standard histopathology.

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

    PubMed Central

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

    2013-01-01

    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 –60 dB 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 20–60 MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16 dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50 μm 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 12 dB lower range side lobe level and a 7 dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50 μm finer and –3 dB 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 200 μm in diameter with 6 dB 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. PMID:22871273

  13. 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.

  14. Comparison of diagnostic and therapeutic value of transesophageal echocardiography, intravascular ultrasonic imaging, and intraluminal phased-array imaging in aortic dissection with tear in the descending thoracic aorta (type B).

    PubMed

    Bartel, Thomas; Eggebrecht, Holger; Müller, Silvana; Gutersohn, Achim; Bonatti, Johannes; Pachinger, Otmar; Erbel, Raimund

    2007-01-15

    Transesophageal echocardiography (TEE) and conventional intravascular ultrasound (IVUS) have limited capabilities in type B aortic dissection. To evaluate its diagnostic value, intraluminal phased-array imaging (IPAI) was compared with IVUS and TEE. In 23 patients with type B aortic dissection, IPAI was tested with respect to its ability to depict true lumen (TL) and false lumen (FL), to localize which abdominal arteries originate from the TL and FL, and to identify all entries and reentries. After the completion of TEE, 2 additional examiners performed angiography and positioned an AcuNav catheter inside the TL. An IVUS catheter was then introduced into the TL by a fourth examiner. All examiners were blinded to one another. Four additional patients with type B aortic dissection developed peripheral malperfusion due to TL collapse. Transvenous IPAI was used to guide emergency fenestration of the intimal flap. TL and FL could be equally well identified by all diagnostic methods. IPAI detected more entries than IVUS (3.0 +/- 1.2 vs 0.8 +/- 0.5, p <0.001), and thoracic IPAI depicted more entries than TEE (1.8 +/- 1.0 vs 1.2 +/- 0.5, p <0.001). IPAI and IVUS showed >90% of the abdominal side branches. In all patients with peripheral malperfusion, successful emergency intimal flap fenestration was safely guided by IPAI. In conclusion, in the detailed diagnostic evaluation of type B aortic dissection, IPAI is superior to IVUS and TEE in detecting communications between the TL and FL. IPAI is also highly useful as a guiding tool for emergency intimal flap fenestration.

  15. Bioresorbable vascular scaffolds for LMCA with double vessel disease under IVUS guidance

    PubMed Central

    Kasturi, Sridhar; Vilvanathan, Vinoth Kumar

    2015-01-01

    An 80-year-old male patient, presented with chest pain. ECG showed ST elevation in leads V2 to V4 and T wave inversion in leads V2-V6. Check angiogram revealed ostial LMCA 70% lesion & mid-LAD 90% lesion and LCX proximal 80% lesion. Predilatation of LMCA lesion was done with 2.0 × 12 mm NC Trek balloon and the LAD lesion with 2.0 × 12 mm and 2.5 × 08 mm (NC Trek balloons). Prestenting IVUS (Intravascular ultrasound) was done with Atlantis SR pro 40 MHz 3.6Fr catheter. IVUS showed the LAD to have a minimal lumen area of 2.6 sq mm with 90% fibrotic plaque and a vessel size of 2.5 mm and the LMCA to have a minimal lumen area of 8.8 sq mm with 70% fibrotic plaque and vessel size of 3.8 mm. Mid-LAD stenting was done with 2.5 × 28 mm Absorb Stent (BVS). Predilatation of LCX lesion was done with 2.5 × 08 mm NC Trek balloon. Then stenting was performed with 3.0 × 28 mm Absorb Stent (BVS). Check angiogram showed edge dissection proximal to the BVS Stent which was covered with 3.0 × 12 mm Xience Xpedtion Stent (DES). Then LMCA Stenting was done with 3.5 × 12 mm Absorb Stent. Post dilatation was done with 4.0 × 08 mm NC Trek balloon. Post Stenting LMCA - LAD IVUS was done. LMCA and LAD Stents were well opposed without any dissection or residual stenosis. TIMI III Flow was achieved in the final results. PMID:26995415

  16. Circulating cytokines in relation to the extent and composition of coronary atherosclerosis: results from the ATHEROREMO-IVUS study.

    PubMed

    Battes, Linda C; Cheng, Jin M; Oemrawsingh, Rohit M; Boersma, Eric; Garcia-Garcia, Hector M; de Boer, Sanneke P M; Buljubasic, Nermina; Mieghem, Nicolas A van; Regar, Evelyn; Geuns, Robert-Jan van; Serruys, Patrick W; Akkerhuis, K Martijn; Kardys, Isabella

    2014-09-01

    We investigated whether concentrations of TNF-α, TNF-β, TNF-receptor 2, interferon-γ, IL-6, IL-8, IL-10 and IL-18 are associated with extent and composition of coronary atherosclerosis determined by grayscale and virtual histology (VH)- intravascular ultrasound (IVUS). Between 2008 and 2011, IVUS(-VH) imaging of a non-culprit coronary artery was performed in 581 patients (stable angina pectoris (SAP), n = 261; acute coronary syndrome (ACS), n = 309) undergoing coronary angiography from the ATHEROREMO-IVUS study. Plaque burden, presence of VH-IVUS-derived thin-cap fibroatheroma (TCFA) lesions, and presence of VH-TCFA lesions with plaque burden ≥70% were assessed. Blood samples for cytokine measurement were drawn from the arterial sheath prior to the angiography procedure. We applied linear and logistic regression. TNF-α levels were positively associated with plaque burden (beta (β) [95%CI]: 4.45 [0.99-7.91], for highest vs lowest TNF-α tertile) and presence of VH-TCFA lesions (odds ratio (OR) [95%CI] 2.30 (1.17-4.52), highest vs lowest TNF-α tertile) in SAP patients. Overall, an inverse association was found between IL-10 concentration and plaque burden (β [95%CI]: -1.52 [-2.49 to -0.55], per Ln (pg/mL) IL-10) as well as IL-10 and VH-TCFA lesions with plaque burden ≥70% (OR: 0.31 [0.12-0.80],highest vs lowest IL-10 tertile). These effects did not reach statistical significance in the separate SAP and ACS groups. Higher circulating TNF-α was associated with higher plaque burden and VH-TCFA lesions in SAP patients. Lower circulating IL-10 was associated with higher plaque burden and large VH-TCFA lesions. These in-vivo findings suggest a role for these cytokines in extent and vulnerability of atherosclerosis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. 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.

  18. Improving quantification of intravascular fluorescence imaging using structural information

    NASA Astrophysics Data System (ADS)

    Mallas, Georgios; Brooks, Dana H.; Rosenthal, Amir; Nika Nudelman, R.; Mauskapf, Adam; Jaffer, Farouc A.; Ntziachristos, Vasilis

    2012-10-01

    Intravascular near-infrared fluorescence (iNIRF) imaging can enable the in vivo visualization of biomarkers of vascular pathology, including high-risk plaques. The technique resolves the bio-distribution of systemically administered fluorescent probes with molecular specificity in the vessel wall. However, the geometrical variations that may occur in the distance between fibre-tip and vessel wall can lead to signal intensity variations and challenge quantification. Herein we examined whether the use of anatomical information of the cross-section vessel morphology, obtained from co-registered intravascular ultrasound (IVUS), can lead to quantification improvements when fibre-tip and vessel wall distance variations are present. The algorithm developed employs a photon propagation model derived from phantom experiments that is used to calculate the relative attenuation of fluorescence signals as they are collected over 360° along the vessel wall, and utilizes it to restore accurate fluorescence readings. The findings herein point to quantification improvements when employing hybrid iNIRF, with possible implications to the clinical detection of high-risk plaques or blood vessel theranostics.

  19. Computer aided diagnosis of Coronary Artery Disease, Myocardial Infarction and carotid atherosclerosis using ultrasound images: A review.

    PubMed

    Faust, Oliver; Acharya, U Rajendra; Sudarshan, Vidya K; Tan, Ru San; Yeong, Chai Hong; Molinari, Filippo; Ng, Kwan Hoong

    2017-01-01

    The diagnosis of Coronary Artery Disease (CAD), Myocardial Infarction (MI) and carotid atherosclerosis is of paramount importance, as these cardiovascular diseases may cause medical complications and large number of death. Ultrasound (US) is a widely used imaging modality, as it captures moving images and image features correlate well with results obtained from other imaging methods. Furthermore, US does not use ionizing radiation and it is economical when compared to other imaging modalities. However, reading US images takes time and the relationship between image and tissue composition is complex. Therefore, the diagnostic accuracy depends on both time taken to read the images and experience of the screening practitioner. Computer support tools can reduce the inter-operator variability with lower subject specific expertise, when appropriate processing methods are used. In the current review, we analysed automatic detection methods for the diagnosis of CAD, MI and carotid atherosclerosis based on thoracic and Intravascular Ultrasound (IVUS). We found that IVUS is more often used than thoracic US for CAD. But for MI and carotid atherosclerosis IVUS is still in the experimental stage. Furthermore, thoracic US is more often used than IVUS for computer aided diagnosis systems. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  20. Use of IVUS guided coronary stenting with drug eluting stent: a systematic review and meta-analysis of randomized controlled clinical trials and high quality observational studies.

    PubMed

    Klersy, Catherine; Ferlini, Marco; Raisaro, Arturo; Scotti, Valeria; Balduini, Anna; Curti, Moreno; Bramucci, Ezio; De Silvestri, Annalisa

    2013-12-05

    Long term safety of DES, particularly regarding thrombosis is of concern. The hypothesized underlying mechanisms (stent under expansion, malapposition) could be prevented by IVUS guidance. Aim of this meta-analysis of randomized controlled clinical trials (RCT) and high quality observational cohort studies (HQ-OBS) is to quantify the potential clinical benefit of intravascular ultrasound (IVUS) guidance in drug-eluting stents (DES) implantation. We performed an extensive literature search for full-text articles published in 2003–2013. The primary outcome was the rate of major adverse cardiac events (MACE) in RCT and HQ-OBS; secondary outcomes were death, myocardial infarction (MI), revascularization, thrombosis and post-procedural minimum lumen diameter (MLD). Fixed/random effect relative risks (RRs) or standardized mean difference (SMD) and 95% confidence interval (95% CI) were computed for the meta-analysis. Thirty-four articles were retrieved from 268 found; of these 3 were RCT and 9 were HQ-OBS; 18,707 patients were enrolled, 1037 in RCT and 17,670 in OBS. Median follow-up was 20 months. IVUS guidance was associated with a significantly lower rate of MACE (RR=0.80, 95% CI 0.71–0.89, p b 0.001), death (RR=0.60, 95% CI 0.48–0.74, p b 0.001), MI (RR=0.59, 95% CI 0.44–0.80, p=0.001) and thrombosis (RR=0.50, 95% CI 0.32–0.80, p=0.007) and larger MLD (SMD=0.15, 95% CI 0.03 to 0.27, p=0.014), but not of revascularization (RR=0.95, 95% CI 0.82–1.09, p=0.75). In this meta-analysis, IVUS guidance in DES implantation appears to reduce MACE, mortality and MI, possibly by reducing thrombosis rather than restenosis rate. Patients at high risk for thrombosis might be identified as the best candidate for IVUS guidance.

  1. Human coronary plaque wall thickness correlated positively with flow shear stress and negatively with plaque wall stress: an IVUS-based fluid-structure interaction multi-patient study.

    PubMed

    Fan, Rui; Tang, Dalin; Yang, Chun; Zheng, Jie; Bach, Richard; Wang, Liang; Muccigrosso, David; Billiar, Kristen; Zhu, Jian; Ma, Genshan; Maehara, Akiko; Mintz, Gary S

    2014-03-26

    Atherosclerotic plaque progression and rupture are believed to be associated with mechanical stress conditions. In this paper, patient-specific in vivo intravascular ultrasound (IVUS) coronary plaque image data were used to construct computational models with fluid-structure interaction (FSI) and cyclic bending to investigate correlations between plaque wall thickness and both flow shear stress and plaque wall stress conditions. IVUS data were acquired from 10 patients after voluntary informed consent. The X-ray angiogram was obtained prior to the pullback of the IVUS catheter to determine the location of the coronary artery stenosis, vessel curvature and cardiac motion. Cyclic bending was specified in the model representing the effect by heart contraction. 3D anisotropic FSI models were constructed and solved to obtain flow shear stress (FSS) and plaque wall stress (PWS) values. FSS and PWS values were obtained for statistical analysis. Correlations with p < 0.05 were deemed significant. Nine out of the 10 patients showed positive correlation between wall thickness and flow shear stress. The mean Pearson correlation r-value was 0.278 ± 0.181. Similarly, 9 out of the 10 patients showed negative correlation between wall thickness and plaque wall stress. The mean Pearson correlation r-value was -0.530 ± 0.210. Our results showed that plaque vessel wall thickness correlated positively with FSS and negatively with PWS. The patient-specific IVUS-based modeling approach has the potential to be used to investigate and identify possible mechanisms governing plaque progression and rupture and assist in diagnosis and intervention procedures. This represents a new direction of research. Further investigations using more patient follow-up data are warranted.

  2. First-in-human experience using the Volcano VIBE-RX vascular imaging balloon catheter system (Volcano IVUS-guided Balloon Evaluation - New Zealand: VIBE-NZ Study).

    PubMed

    Watson, Timothy; El-Jack, Seifeddin; Stewart, James T; Ormiston, John

    2013-09-01

    Intravascular ultrasound (IVUS) is a proven and safe imaging modality used to guide percutaneous coronary intervention (PCI). The Volcano VIBE™ RX Vascular Imaging Balloon Catheter is a novel rapid exchange, 0.014" wire-compatible multi-lumen conventional balloon catheter modified with the addition of an IVUS transducer proximal to the balloon, delivered via a standard 6 Fr sheath. We sought to evaluate the safety, balloon performance, and image quality of the VIBE™ RX in patients scheduled for coronary intervention. Patients aged >21 and <85 years with single or multivessel coronary disease scheduled for PCI due to coronary ischaemic symptoms were included. Those with angiographic features that precluded the safe or informative use of the device were excluded. Twenty-nine patients having angiography because of ischaemic symptoms underwent 44 VIBE RX imaging runs, with balloon dilation in 20. Successful device deployment was achieved in all but one patient. All images were adequate and reproducible. One patient had a non-ST-elevation MI felt to be due to the complexity of the procedure rather than directly related to the VIBE™ RX. The study demonstrated the safety and effectiveness of the VIBE™ RX for its intended purpose with minimal failure rate and no directly related complications.

  3. Intravascular ultrasound-guided percutaneous coronary intervention in a human immunodeficiency virus-positive patient with cocaine-associated acute myocardial infarction: case report and review.

    PubMed

    Sonne, Carolin; Stempfle, Hans-Ulrich; Klauss, Volker; Schiele, Thomas M

    2005-09-01

    Cocaine use is a major problem worldwide and there are numerous reports about cocaine-associated myocardial infarction. Nevertheless minimal data are available from randomised clinical trials to suggest evidence-based approaches to the management of cocaine-associated myocardial ischemia. Moreover, most reports have been limited to conservative management of cocaine-associated myocardial infarction. We report a case of a young male cocaine user with acute myocardial infarction, undergoing diagnostic coronary angiography and intravascular ultrasound revealing severe atherosclerosis, followed by successful stent implantation.

  4. The salvage of graft occlusion in a maintenace hemodialysis patient with tuberous sclerosis by percutaneous transluminal angioplasty using intravascular ultrasound: case report.

    PubMed

    Higuchi, Terumi; Abe, Masanori; Okada, Kazuyoshi; Nakajima, Yoshiko; Ohnishi, Yoshihiko; Hagi, Chihiro; Fukuda, Noboru; Kuno, Tsutomu; Takahashi, Susumu; Saito, Satoshi; Nagura, Yuji; Matsumoto, Koichi

    2004-04-01

    End-stage renal failure due to tuberous sclerosis is rare and there is no previous report of a patient with tuberous sclerosis undergoing long-term hemodialysis for over 18 years. The patency rate for a dialysis prosthetic graft is low, however, our patient's graft survived over 16 years. For thrombotic occlusion of a graft, we performed percutaneous thrombectomy and balloon angioplasty and salvaged graft occlusion. Moreover, this case is the first report in which the interventional procedure (mechanical thrombectomy and balloon angioplasty) could be observed by intravascular ultrasound in addition to angiography.

  5. In vivo CT detection of lipid-rich coronary artery atherosclerotic plaques using quantitative histogram analysis: a head to head comparison with IVUS.

    PubMed

    Marwan, Mohamed; Taher, Mohamed Awad; El Meniawy, Khaled; Awadallah, Hany; Pflederer, Tobias; Schuhbäck, Annika; Ropers, Dieter; Daniel, Werner G; Achenbach, Stephan

    2011-03-01

    Coronary atherosclerotic plaque characterisation may contribute to risk stratification for future cardiovascular events. The ability of computed tomography to classify plaques as 'fibrous' or 'lipid-rich' based on their average CT attenuation has been investigated but is fraught with substantial limitations. In this study, we evaluated the potential of analysing the distribution of CT attenuation values measured in Hounsfield Units (HU) within coronary atherosclerotic plaques to classify non-calcified plaques into fibrous and lipid-rich subtypes. Intravascular ultrasound (IVUS) served as the gold standard. We evaluated the data sets of 40 patients (30 males, 59±10 years) who had been referred for invasive coronary angiography for clinical reasons and in whom IVUS was performed in at least one coronary vessel. Using dual source CT, coronary CT angiography was performed as a part of a research protocol within 24 h previous to invasive coronary angiography. A contrast-enhanced volume dataset was acquired with retrospective ECG gating (120 kV, 400 mAs/rot, collimation 2 mm×64 mm×0.6 mm, 60-80 ml contrast agent i.v). IVUS was performed using a 40-MHz IVUS catheter (Atlantis, Boston Scientific Corporation, Natick, MA) and motorized pullback at 0.5 mm/s. Fifty five corresponding non-calcified plaques within the coronary artery system were identified in both DSCT and IVUS using bifurcation points as fiducial markers. In DSCT data sets, serial parallel cross-sections (1mm slice thickness) were rendered orthogonally to the centre line of the coronary artery for each of the 55 plaques. For each cross section and each plaque, a histogram of CT attenuation values (increments of 10HU) was determined. The percentage of pixels with a density ≤30 HU was calculated. Using IVUS as the gold standard, plaques were classified as predominantly fibrous (hyperechoic) or predominantly lipid-rich (hypoechoic). 15 predominantly fibrous plaques vs. 40 predominantly lipid-rich plaques were

  6. Anatomical and Physiological Changes after Paclitaxel-Coated Balloon for Atherosclerotic De Novo Coronary Lesions: Serial IVUS-VH and FFR Study

    PubMed Central

    Ann, Soe Hee; Balbir Singh, Gillian; Lim, Kyung Hun; Koo, Bon-Kwon; Shin, Eun-Seok

    2016-01-01

    Aims To assess the serial changes of de novo coronary lesions treated with paclitaxel-coated balloon (PCB) using intravascular ultrasound virtual histology (IVUS-VH) and fractional flow reserve (FFR). Method and Results This prospective observational study enrolled 27 patients with coronary artery disease treated with PCB who underwent coronary angiography, IVUS-VH and FFR before, immediately after intervention and at 9 months. 28 de novo lesions were successfully treated with PCB. Angiographic late luminal loss was 0.02 ± 0.27mm. Mean vessel and lumen areas showed increase at 9 months (12.0 ± 3.5mm2 to 13.2 ± 3.9mm2, p <0.001; and 5.4 ± 1.2mm2 to 6.5 ± 1.8mm2, p <0.001, respectively). Although mean plaque area was unchanged (6.6 ± 2.6mm2 to 6.6 ± 2.4mm2, p = 0.269), percent atheroma volume decreased significantly (53.4 ± 7.9% to 49.5 ± 6.4%, p = 0.002). The proportion of plaque compositions including fibrous, fibrofatty, dense calcium and necrotic core by IVUS-VH was unchanged at 9 months. The FFR of the treated lesion was 0.71 ± 0.13 pre-procedure, 0.87 ± 0.06 post-procedure and 0.84 ± 0.06 at follow-up. Conclusions De novo coronary lesions treated with PCB showed persistent anatomical and physiological patency with plaque redistribution and vessel remodeling without chronic elastic recoil or plaque compositional change during follow-up. PMID:26824602

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

    PubMed Central

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

    2016-01-01

    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, which reconstructs elasticity maps (or modulograms) of atheroma plaques from the estimation of strain fields. In the present in vitro experimental study, conducted on PVA-C 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 values and sensitivities 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. PMID:20826899

  8. Effects of Residual Stress, Axial Stretch, and Circumferential Shrinkage on Coronary Plaque Stress and Strain Calculations: A Modeling Study Using IVUS-Based Near-Idealized Geometries.

    PubMed

    Wang, Liang; Zhu, Jian; Samady, Habib; Monoly, David; Zheng, Jie; Guo, Xiaoya; Maehara, Akiko; Yang, Chun; Ma, Genshan; Mintz, Gary S; Tang, Dalin

    2017-01-01

    Accurate stress and strain calculations are important for plaque progression and vulnerability assessment. Models based on in vivo data often need to form geometries with zero-stress/strain conditions. The goal of this paper is to use IVUS-based near-idealized geometries and introduce a three-step model construction process to include residual stress, axial shrinkage, and circumferential shrinkage and investigate their impacts on stress and strain calculations. In Vivo intravascular ultrasound (IVUS) data of human coronary were acquired for model construction. In Vivo IVUS movie data were acquired and used to determine patient-specific material parameter values. A three-step modeling procedure was used to make our model: (a) wrap the zero-stress vessel sector to obtain the residual stress; (b) stretch the vessel axially to its length in vivo; and (c) pressurize the vessel to recover its in vivo geometry. Eight models were constructed for our investigation. Wrapping led to reduced lumen and cap stress and increased out boundary stress. The model with axial stretch, circumferential shrink, but no wrapping overestimated lumen and cap stress by 182% and 448%, respectively. The model with wrapping, circumferential shrink, but no axial stretch predicted average lumen stress and cap stress as 0.76 kPa and -15 kPa. The same model with 10% axial stretch had 42.53 kPa lumen stress and 29.0 kPa cap stress, respectively. Skipping circumferential shrinkage leads to overexpansion of the vessel and incorrect stress/strain calculations. Vessel stiffness increase (100%) leads to 75% lumen stress increase and 102% cap stress increase.

  9. Circulating acute phase proteins in relation to extent and composition of coronary atherosclerosis and cardiovascular outcome: results from the ATHEROREMO-IVUS study.

    PubMed

    Battes, Linda C; Akkerhuis, K Martijn; Cheng, Jin M; Garcia-Garcia, Hector M; Oemrawsingh, Rohit M; de Boer, Sanneke P M; Regar, Evelyn; van Geuns, Robert-Jan; Serruys, Patrick W; Boersma, Eric; Kardys, Isabella

    2014-12-20

    We examined whether the acute phase proteins (APPs): Alpha-1-Antitrypsin, Alpha-2-Macroglobulin, Complement C3, ferritin, haptoglobin, and Plasminogen Activator Inhibitor 1 (PAI-1) are associated with cardiovascular outcome, as well as with the extent and composition of coronary atherosclerosis as determined by intravascular ultrasound (IVUS) virtual histology (VH). In 2008-2011, IVUS(-VH) imaging of a non-culprit coronary artery was performed in 581 patients from the ATHEROREMO-IVUS study undergoing coronary angiography for acute coronary syndrome (ACS) (n=318) or stable angina pectoris (SAP) (n=263). Coronary atherosclerotic plaque volume, composition (fibrous, fibro-fatty, dense calcium and necrotic core) and vulnerability (VH-derived thin-cap fibroatheroma (TCFA) lesions) were assessed. Major adverse cardiac events (MACE; all-cause mortality, ACS or unplanned coronary revascularization) were assessed during 1-year follow-up. We applied linear, logistic and Cox regression. Mean age was 61.5 ± 11.4 years and 75.4% were men. Higher ferritin was associated with higher coronary plaque volume (beta [95% CI]: 0.19 [0.07-0.31] percent atheroma volume), for the highest vs the lowest tertile of ferritin; p for linear association=0.013. Higher PAI-1 was associated with higher rates of all-cause mortality or ACS (hazard ratio [95% CI]: 2.98 [1.10-8.06]), for the highest vs the lowest tertile of PAI-1. No clear-cut associations could be demonstrated between APPs and composition of atherosclerosis or plaque vulnerability. Higher circulating ferritin was associated with higher coronary plaque volume, and higher PAI-1 was associated with higher incidence of all-cause mortality or ACS. None of the APPs displayed consistent associations with composition of atherosclerosis or plaque vulnerability. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. 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.

  11. Anatomical and Physiological Changes after Paclitaxel-Coated Balloon for Atherosclerotic De Novo Coronary Lesions: Serial IVUS-VH and FFR Study.

    PubMed

    Ann, Soe Hee; Balbir Singh, Gillian; Lim, Kyung Hun; Koo, Bon-Kwon; Shin, Eun-Seok

    2016-01-01

    To assess the serial changes of de novo coronary lesions treated with paclitaxel-coated balloon (PCB) using intravascular ultrasound virtual histology (IVUS-VH) and fractional flow reserve (FFR). This prospective observational study enrolled 27 patients with coronary artery disease treated with PCB who underwent coronary angiography, IVUS-VH and FFR before, immediately after intervention and at 9 months. 28 de novo lesions were successfully treated with PCB. Angiographic late luminal loss was 0.02 ± 0.27 mm. Mean vessel and lumen areas showed increase at 9 months (12.0 ± 3.5 mm(2) to 13.2 ± 3.9 mm(2), p <0.001; and 5.4 ± 1.2 mm(2) to 6.5 ± 1.8 mm(2), p <0.001, respectively). Although mean plaque area was unchanged (6.6 ± 2.6 mm2 to 6.6 ± 2.4 mm(2), p = 0.269), percent atheroma volume decreased significantly (53.4 ± 7.9% to 49.5 ± 6.4%, p = 0.002). The proportion of plaque compositions including fibrous, fibrofatty, dense calcium and necrotic core by IVUS-VH was unchanged at 9 months. The FFR of the treated lesion was 0.71 ± 0.13 pre-procedure, 0.87 ± 0.06 post-procedure and 0.84 ± 0.06 at follow-up. De novo coronary lesions treated with PCB showed persistent anatomical and physiological patency with plaque redistribution and vessel remodeling without chronic elastic recoil or plaque compositional change during follow-up.

  12. Impact of intracoronary injection of CD133+ bone marrow stem cells on coronary atherosclerotic progression in patients with STEMI: a COMPARE-AMI IVUS substudy.

    PubMed

    Qiu, Fuyu; Maehara, Akiko; El Khoury, Ramez; Généreux, Philippe; LaSalle, Laura; Mintz, Gary S; Noiseux, Nicolas; Roy, Denis-Claude; Gobeil, François; Stevens, Louis-Mathieu; Reeves, François; Leclerc, Guy; Rivard, Alain; Mansour, Samer

    2016-01-01

    Adverse effects of intracoronary injection of stem cells on in-stent restenosis and atherosclerotic progression remain unclear. We sought to evaluate the adverse effects of intracoronary injection of CD133 cells on in-stent restenosis and atherosclerotic progression in the infarct-related and contralateral arteries using serial intravascular ultrasound (IVUS) analysis. Baseline and 4-month follow-up IVUS images were obtained from 17 patients treated with intracoronary stem cell injection and 20 placebo patients after primary percutaneous coronary intervention in the COMPARE-AMI trial. In the infarct-related artery, the stented segment, 5 mm proximal and distal reference segments, and proximal and distal nonstented segments were analyzed every 1 mm; the entire segment of a contralateral artery was also analyzed every 1 mm. In the infarct-related artery analysis, the median percentage of in-stent neointimal hyperplasia (12.1 vs. 7.6%, P=0.95), the reduction in the minimum lumen area (MLA; -1.6 vs. -1.5 mm(2), P=0.97), and the MLA at follow-up (4.3 vs. 5.3 mm(2), P=0.21) were found to be similar between the stem cell and placebo groups. Changes in proximal and distal nonstented segment lumen areas and plaque burden were also similar between the stem cell and placebo groups; however, there was a decrease in the maximum arc of the attenuated plaque behind the stent from baseline to follow-up in the placebo group (P=0.004), but not in the stem cell group. In the contralateral artery, there were no differences in changes in MLA, plaque burden, or attenuated plaque between stem cell and placebo patients. Intracoronary injection of CD133(+) bone marrow stem cells has no IVUS-detectable effect on neointimal hyperplasia or atherosclerosis progression in either infarct-related or contralateral arteries.

  13. Intravascular ultrasound guidance of percutaneous coronary intervention in ostial chronic total occlusions: a description of the technique and procedural results.

    PubMed

    Ryan, Nicola; Gonzalo, Nieves; Dingli, Philip; Cruz, Oscar Vedia; Jiménez-Quevedo, Pilar; Nombela-Franco, Luis; Nuñez-Gil, Ivan; Trigo, María Del; Salinas, Pablo; Macaya, Carlos; Fernandez-Ortiz, Antonio; Escaned, Javier

    2017-02-14

    Inability to cross the lesion with a guidewire is the most common reason for failure in percutaneous revascularization (PCI) of chronic total occlusions (CTOs). An ostial or stumpless CTO is an acknowledged challenge for CTO recanalization due to difficulty in successful wiring. IVUS imaging provides the opportunity to visualize the occluded vessel and to aid guidewire advancement. We review the value of this technique in a single-centre experience of CTO PCI. This series involves 22 patients who underwent CTO-PCI using IVUS guidance for stumpless CTO wiring at our institution. CTO operators with extensive IVUS experience in non-CTO cases carried out all procedures. Procedural and outcome data was prospectively entered into the institutional database and a retrospective analysis of clinical, angiographic and technical data performed. 17 (77%) of the 22 procedures were successful. The mean age was 59.8 ± 11.5 years, and 90.9% were male. The most commonly attempted lesions were located in the left anterior descending 36.4% (Soon et al. in J Intervent Cardiol 20(5):359-366, 2007) and Circumflex artery (LCx) 31.8% (Mollet et al. in Am J Cardiol 95(2):240-243, 2005). Mean JCTO score was 3.09 ± 0.75 (3.06 ± 0.68, 3.17 ± 0.98 in the successful and failed groups respectively p = 0.35). The mean contrast volume was 378.7 ml ± 114.7 (389.9 ml ± 130.5, 349.2 ml ± 52.2 p = 0.3 in the successful and failed groups respectively). There was no death, coronary artery bypass grafting or myocardial infarction requiring intervention in this series. When the success rates were analyzed taking into account the date of adoption of this technique, the learning curve had no significant impact on CTO-PCI success. This series describes a good success rate in IVUS guided stumpless wiring of CTOs in consecutive patients with this complex anatomical scenario.

  14. Neointimal hyperplasia in a thin-strut cobalt-chromium stent: insights from detailed 3-D intravascular ultrasound analysis.

    PubMed

    Otake, Hiromasa; Ako, Junya; Waseda, Katsuhisa; Sakurai, Ryota; Hirohata, Atsushi; Kaneda, Hideaki; Hasegawa, Takao; Honda, Yasuhiro; Fitzgerald, Peter J

    2010-11-05

    The effect of current generation cobalt-chromium stents on neointimal proliferation has not been fully elucidated. IVUS images of 137 patients treated with a single thin-strut cobalt-chromium stent (Driver: DRI, n=74) or stainless steel stent (Multilink plus: ML, n=63) were selected. Although % neointima volume (neointimal volume divided by stent volume) were comparable, DRI showed significantly smaller maximum %cross-sectional narrowing (%CSN: neointimal area divided by stent area) (P=0.006) with significantly less %CSN>60 (percent stent length with %CSN>60%) than ML (P=0.04). In conclusion, the amount of neointimal hyperplasia after DRI implantation was comparable to that after ML. However, current generation cobalt-chromium DRI may show less and shorter severe narrowing than the stainless steel ML.

  15. Acoustic Radiation Force Impulse Imaging (ARFI) on an IVUS Circular Array

    PubMed Central

    Patel, Vivek; Dahl, Jeremy; Bradway, David; Doherty, Joshua; Lee, Seung Yun; Smith, Stephen

    2014-01-01

    Our long-term goal is the detection and characterization of vulnerable plaque in the coronary arteries of the heart using IVUS catheters. Vulnerable plaque, characterized by a thin fibrous cap and a soft, lipid-rich, necrotic core is a pre-cursor to heart attack and stroke. Early detection of such plaques may potentially alter the course of treatment of the patient in order to prevent ischemic events. We have previously described the characterization of carotid plaques using external linear arrays operating at 9 MHz. In addition, we previously modified circular array IVUS catheters by short-circuiting several neighboring elements to produce fixed beam-widths for intra-vascular hyperthermia applications. In this paper we modified Volcano Visions 8.2 French, 9 MHz catheters and Volcano Platinum 3.5 French, 20 MHz catheters by short circuiting portions of the array for ARFI applications. The catheters had an effective transmit aperture size of 2 mm and 1.5 mm respectively. The catheters were connected to a Verasonics scanner and driven with pushing pulses of 180 V p-p to acquire ARFI data from a soft gel phantom with a Young’s modulus of 2.9 kPa. The dynamic response of the tissue-mimicking material demonstrates a typical ARFI motion of 1–2 microns as the gel phantom displaces away and recovers back to its normal position. The hardware modifications applied to our IVUS catheters mimic potential beamforming modifications that could be implemented on IVUS scanners. Our results demonstrate that the generation of radiation force from IVUS catheters and the development of intra-vascular ARFI may be feasible. PMID:24554291

  16. Prospective application of pre-defined intravascular ultrasound criteria for assessment of intermediate left main coronary artery lesions results from the multicenter LITRO study.

    PubMed

    de la Torre Hernandez, Jose M; Hernández Hernandez, Felipe; Alfonso, Fernando; Rumoroso, Jose R; Lopez-Palop, Ramon; Sadaba, Mario; Carrillo, Pilar; Rondan, Juan; Lozano, Iñigo; Ruiz Nodar, Juan M; Baz, Jose A; Fernandez Nofrerias, Eduard; Pajin, Fernando; Garcia Camarero, Tamara; Gutierrez, Hipolito

    2011-07-19

    This study is a prospective validation of 6 mm(2) as a minimum lumen area (MLA) cutoff value for revascularization of left main coronary artery (LMCA) lesions. Lesions involving the LMCA are prognostically relevant. Angiography has important limitations in the evaluation of LMCA lesions with intermediate severity. An MLA of 6 mm(2) assessed by intravascular ultrasound has been proposed as a cutoff value to determine lesion severity, but there are no large studies evaluating the prospective application and safety of this approach. We have designed a multicenter, prospective study. Consecutive patients with intermediate lesions in unprotected LMCA were evaluated with intravascular ultrasound. An MLA <6 mm(2) was used as criterion for revascularization. A total of 354 patients were included in 22 centers. LMCA revascularization was performed in 90.5% (152 of 168) of patients with an MLA <6 mm(2) and was deferred in 96% (179 of 186) of patients with an MLA of 6 mm(2) or more. A large scatter was observed between both groups regarding angiographic parameters. In a 2-year follow-up period, cardiac death-free survival was 97.7% in the deferred group versus 94.5% in the revascularized group (p = 0.5), and event-free survival was 87.3% versus 80.6%, respectively (p = 0.3). In the 2-year period, only 8 (4.4%) patients in the deferred group required subsequent LMCA revascularization, none with an infarction. Angiographic measurements are not reliable in the assessment of intermediate LMCA lesions. An MLA of 6 mm(2) or more is a safe value for deferring revascularization of the LMCA, given the application of the clinical and angiographic inclusion criteria used in this study. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  17. Automatic media-adventitia IVUS image segmentation based on sparse representation framework and dynamic directional active contour model.

    PubMed

    Zakeri, Fahimeh Sadat; Setarehdan, Seyed Kamaledin; Norouzi, Somayye

    2017-03-25

    Segmentation of the arterial wall boundaries from intravascular ultrasound images is an important image processing task in order to quantify arterial wall characteristics such as shape, area, thickness and eccentricity. Since manual segmentation of these boundaries is a laborious and time consuming procedure, many researchers attempted to develop (semi-) automatic segmentation techniques as a powerful tool for educational and clinical purposes in the past but as yet there is no any clinically approved method in the market. This paper presents a deterministic-statistical strategy for automatic media-adventitia border detection by a fourfold algorithm. First, a smoothed initial contour is extracted based on the classification in the sparse representation framework which is combined with the dynamic directional convolution vector field. Next, an active contour model is utilized for the propagation of the initial contour toward the interested borders. Finally, the extracted contour is refined in the leakage, side branch openings and calcification regions based on the image texture patterns. The performance of the proposed algorithm is evaluated by comparing the results to those manually traced borders by an expert on 312 different IVUS images obtained from four different patients. The statistical analysis of the results demonstrates the efficiency of the proposed method in the media-adventitia border detection with enough consistency in the leakage and calcification regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. 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

  19. Prevalence, Features, and Prognostic Importance of Edge Dissection After Drug-Eluting Stent Implantation: An ADAPT-DES Intravascular Ultrasound Substudy.

    PubMed

    Kobayashi, Nobuaki; Mintz, Gary S; Witzenbichler, Bernhard; Metzger, D Christopher; Rinaldi, Michael J; Duffy, Peter L; Weisz, Giora; Stuckey, Thomas D; Brodie, Bruce R; Parvataneni, Rupa; Kirtane, Ajay J; Stone, Gregg W; Maehara, Akiko

    2016-07-01

    Intravascular ultrasound detects stent edge dissections after percutaneous coronary intervention that are not seen angiographically. This study investigated the association between stent edge dissections and clinical outcomes. ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a large-scale, prospective, multicenter study of patients undergoing drug-eluting stent implantation. In this prospective substudy, 2062 patients (2433 lesions) were evaluated with intravascular ultrasound to characterize the morphological features and clinical outcomes of stent edge dissection after percutaneous coronary intervention. The prevalence of post-percutaneous coronary intervention stent edge dissection was 6.6% per lesion (161 of 2433). Calcified plaque at the proximal stent edge (relative risk [RR]=1.72; P=0.04) and proximal stent edge expansion (RR=1.18; P=0.004) were predictors for proximal dissection; attenuated plaque at the distal stent edge (RR=3.52; P=0.004), distal reference plaque burden (RR=1.56; P<0.0001), and distal edge stent expansion (RR=1.11; P=0.02) were predictors for distal dissection. At 1-year follow-up, target lesion revascularization was more common in lesions with versus without dissection (5.2% versus 2.7%; P=0.04). Multivariable analysis indicated that residual dissection was associated with target lesion revascularization at 1-year follow-up (RR=2.67; P=0.02). Among lesions with dissection, smaller effective lumen area increased the risk of target lesion revascularization at 1-year follow-up (cutoff value of 5.1 mm(2); P=0.05). Greater stent expansion and the presence of large, calcified, and/or attenuated plaques were independent predictors of stent edge dissection. Residual stent edge dissection, especially with a smaller effective lumen area, was associated with target lesion revascularization during 1-year follow-up after drug-eluting stent implantation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794

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

    PubMed

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

    2014-11-01

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

  1. Long-term safety and feasibility of three-vessel multimodality intravascular imaging in patients with ST-elevation myocardial infarction: the IBIS-4 (integrated biomarker and imaging study) substudy.

    PubMed

    Taniwaki, Masanori; Radu, Maria D; Garcia-Garcia, Hector M; Heg, Dik; Kelbæk, Henning; Holmvang, Lene; Moschovitis, Aris; Noble, Stephane; Pedrazzini, Giovanni; Saunamäki, Kari; Dijkstra, Jouke; Landmesser, Ulf; Wenaweser, Peter; Meier, Bernhard; Stefanini, Giulio G; Roffi, Marco; Lüscher, Thomas F; Windecker, Stephan; Räber, Lorenz

    2015-06-01

    We assessed the feasibility and the procedural and long-term safety of intracoronary (i.c) imaging for documentary purposes with optical coherence tomography (OCT) and intravascular ultrasound (IVUS) in patients with acute ST-elevation myocardial infarction (STEMI) undergoing primary PCI in the setting of IBIS-4 study. IBIS4 (NCT00962416) is a prospective cohort study conducted at five European centers including 103 STEMI patients who underwent serial three-vessel coronary imaging during primary PCI and at 13 months. The feasibility parameter was successful imaging, defined as the number of pullbacks suitable for analysis. Safety parameters included the frequency of peri-procedural complications, and major adverse cardiac events (MACE), a composite of cardiac death, myocardial infarction (MI) and any clinically-indicated revascularization at 2 years. Clinical outcomes were compared with the results from a cohort of 485 STEMI patients undergoing primary PCI without additional imaging. Imaging of the infarct-related artery at baseline (and follow-up) was successful in 92.2% (96.6%) of patients using OCT and in 93.2% (95.5%) using IVUS. Imaging of the non-infarct-related vessels was successful in 88.7% (95.6%) using OCT and in 90.5% (93.3%) using IVUS. Periprocedural complications occurred <2.0% of OCT and none during IVUS. There were no differences throughout 2 years between the imaging and control group in terms of MACE (16.7 vs. 13.3%, adjusted HR1.40, 95% CI 0.77-2.52, p = 0.27). Multi-modality three-vessel i.c. imaging in STEMI patients undergoing primary PCI is consistent a high degree of success and can be performed safely without impact on cardiovascular events at long-term follow-up.

  2. 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.

  3. Synergistic effect of ezetimibe addition on coronary atheroma regression in patients with prior statin therapy: Subanalysis of PRECISE-IVUS trial.

    PubMed

    Tsujita, Kenichi; Yamanaga, Kenshi; Komura, Naohiro; Sakamoto, Kenji; Sugiyama, Seigo; Sumida, Hitoshi; Shimomura, Hideki; Yamashita, Takuro; Oka, Hideki; Nakao, Koichi; Nakamura, Sunao; Ishihara, Masaharu; Matsui, Kunihiko; Sakaino, Naritsugu; Nakamura, Natsuki; Yamamoto, Nobuyasu; Koide, Shunichi; Matsumura, Toshiyuki; Fujimoto, Kazuteru; Tsunoda, Ryusuke; Morikami, Yasuhiro; Matsuyama, Koushi; Oshima, Shuichi; Kaikita, Koichi; Hokimoto, Seiji; Ogawa, Hisao

    2016-09-01

    The IMPROVE-IT trial showed that the clinical benefit of statin/ezetimibe combination appeared to be pronounced in patients with prior statin therapy. We hypothesized that the antiatherosclerotic effect of atorvastatin/ezetimibe combination was pronounced in patients with statin pretreatment. In the prospective, randomized, controlled, multicenter PRECISE-IVUS trial, 246 patients undergoing intravascular ultrasound-guided percutaneous coronary intervention were randomized to atorvastatin/ezetimibe combination or atorvastatin alone. The dosage of atorvastatin was uptitrated with a treatment goal of lowering low-density lipoprotein cholesterol to below 70 mg/dl in both groups. Serial volumetric intravascular ultrasound was performed at baseline and 9-12 month follow-up to quantify the coronary plaque response in 202 patients. We compared the intravascular ultrasound endpoints in all subjects, stratified by the presence or absence of statin pretreatment. The baseline low-density lipoprotein cholesterol level (100.7 ± 23.1 mg/dl vs. 116.4 ± 25.9 mg/dl, p < 0.001) and lathosterol (55 (38 to 87)) µg/100 mg total cholesterol vs. 97 (57 to 149) µg/100 mg total cholesterol, p < 0.001) was significantly lower, and campesterol/lathosterol ratio (3.9 (2.4 to 7.4) vs. 2.6 (1.5 to 4.1), p < 0.001) was significantly increased in patients with statin pretreatment. Contrary to the patients without statin pretreatment (-1.3 (-3.1 to -0.1)% vs. -0.9 (-2.3 to 0.9)%, p = 0.12), the atorvastatin/ezetimibe combination showed a significantly stronger reduction in delta percent atheroma volume, compared with atorvastatin alone, in patients with statin pretreatment (-1.8 (-3.6 to -0.3)% vs. -0.1 (-1.6 to 0.8)%, p = 0.002). Compensatory increase in cholesterol absorption observed in statin-treated patients might attenuate the inhibitory effects of statins on coronary plaque progression. A low-dose statin/ezetimibe combination might be a promising

  4. Standardized evaluation methodology and reference database for evaluating IVUS image segmentation.

    PubMed

    Balocco, Simone; Gatta, Carlo; Ciompi, Francesco; Wahle, Andreas; Radeva, Petia; Carlier, Stephane; Unal, Gozde; Sanidas, Elias; Mauri, Josepa; Carillo, Xavier; Kovarnik, Tomas; Wang, Ching-Wei; Chen, Hsiang-Chou; Exarchos, Themis P; Fotiadis, Dimitrios I; Destrempes, François; Cloutier, Guy; Pujol, Oriol; Alberti, Marina; Mendizabal-Ruiz, E Gerardo; Rivera, Mariano; Aksoy, Timur; Downe, Richard W; Kakadiaris, Ioannis A

    2014-03-01

    This paper describes an evaluation framework that allows a standardized and quantitative comparison of IVUS lumen and media segmentation algorithms. This framework has been introduced at the MICCAI 2011 Computing and Visualization for (Intra)Vascular Imaging (CVII) workshop, comparing the results of eight teams that participated. We describe the available data-base comprising of multi-center, multi-vendor and multi-frequency IVUS datasets, their acquisition, the creation of the reference standard and the evaluation measures. The approaches address segmentation of the lumen, the media, or both borders; semi- or fully-automatic operation; and 2-D vs. 3-D methodology. Three performance measures for quantitative analysis have been proposed. The results of the evaluation indicate that segmentation of the vessel lumen and media is possible with an accuracy that is comparable to manual annotation when semi-automatic methods are used, as well as encouraging results can be obtained also in case of fully-automatic segmentation. The analysis performed in this paper also highlights the challenges in IVUS segmentation that remains to be solved. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. The different association of epicardial fat with coronary plaque in patients with acute coronary syndrome and patients with stable angina pectoris: analysis using integrated backscatter intravascular ultrasound.

    PubMed

    Harada, Kazuhiro; Harada, Ken; Uetani, Tadayuki; Kataoka, Tadashi; Takeshita, Masahiro; Kunimura, Ayako; Takayama, Yohei; Shinoda, Norihiro; Kato, Bunichi; Kato, Masataka; Marui, Nobuyuki; Ishii, Hideki; Matsubara, Tatsuaki; Amano, Tetsuya; Murohara, Toyoaki

    2014-10-01

    We assessed the hypothesis that the epicardial fat is associated with coronary lipid plaque. Epicardial fat volume (EFV) is increased in patients with acute coronary syndrome (ACS), and lipid-rich plaques have been associated with acute coronary events. We enrolled 112 individuals who underwent percutaneous coronary intervention (PCI) (66 with ACS; 46 with stable angina pectoris [SAP]) and classified plaque components using integrated backscatter intravascular ultrasound as calcified, fibrous, or lipid. Possible effects of PCI on plaque data were minimized by assessing 10-mm vessel lengths proximal to the culprit lesions. Total plaque volume and percentage volumes of individual plaque components were calculated. EFV and abdominal visceral fat area were measured using 64-slice computed tomography. ACS patients had significantly higher EFV than did SAP patients (118 ± 44 vs.101 ± 41 mL, p = 0.019). In ACS patients, EFV was correlated with total plaque volume and percentage of lipid plaque (r = 0.27 and 0.31, respectively; p < 0.05). Moreover, an independent interaction between EFV and lipid-rich plaque (odds ratio, 1.04; 95% confidence interval, 1.00-1.07) were revealed. In contrast, in SAP patients, EFV was positively correlated with body mass index and abdominal visceral fat area but not with plaque characteristics. EFV was associated with lipid-rich plaque in patients with ACS, whereas no correlation between EFV and coronary plaque profile was apparent in SAP patients. Epicardial fat may have a role in the development of lipid plaque, which contributes to the pathogenesis of ACS. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. Characterisation of coronary atherosclerotic morphology by spectral analysis of radiofrequency signal: in vitro intravascular ultrasound study with histological and radiological validation

    PubMed Central

    Moore, M; Spencer, T; Salter, D; Kearney, P; Shaw, T; Starkey, I; Fitzgerald, P; Erbel, R; Lange, A; McDicken, N; Sutherland, G; Fox, K

    1998-01-01

    significantly from moderately fibrotic tissue, dense fibrotic tissue, microcalcification, and heavy calcium. No significant differences in any of the measured parameters were seen between the results obtained from small and large ROIs.
Conclusion—Frequency based spectral analysis of unprocessed ultrasound signal may lead to accurate identification of atherosclerotic plaque morphology.

 Keywords: tissue characterisation;  intravascular ultrasound;  spectral analysis;  radiofrequency data PMID:9659192

  12. Inhibition of plaque progression and promotion of plaque stability by glucagon-like peptide-1 receptor agonist: Serial in vivo findings from iMap-IVUS in Watanabe heritable hyperlipidemic rabbits.

    PubMed

    Sudo, Mitsumasa; Li, Yuxin; Hiro, Takafumi; Takayama, Tadateru; Mitsumata, Masako; Shiomi, Masashi; Sugitani, Masahiko; Matsumoto, Taro; Hao, Hiroyuki; Hirayama, Atsushi

    2017-10-01

    Glucagon-like peptide-1 (GLP-1) is thought to inhibit development of aortic atherosclerosis and plaque formation. However, whether GLP-1 stabilizes fully developed atherosclerotic plaque or alters the complicated plaque composition remains unclarified. Ten Watanabe heritable hyperlipidemic (WHHL) rabbits were divided into GLP-1 receptor agonist treatment group and control group. After confirmation of atherosclerotic plaques in brachiocephalic arteries by iMap intravascular ultrasound (iMAP-IVUS), GLP-1 receptor agonist lixisenatide was administered to WHHL rabbits at 30 nmoL/kg/day for 12 weeks by osmotic pump. An equal volume of normal saline was administered in a control group. After evaluation by iMAP-IVUS at 12 weeks, brachiocephalic arteries were harvested for pathological histological analysis. iMAP-IVUS analysis revealed larger fibrotic plaque components and smaller necrotic and calcified plaque components in the GLP-1 group than in the control group; %fibrotic area: 66.30 ± 2.06% vs. 75.14 ± 2.62%, p < 0.01, %necrotic area: 23.25 ± 1.87% vs. 16.17 ± 2.27%, p = 0.02, %calcified area: 2.15 ± 0.24% vs. 1.00 ± 0.18%, p < 0.01), indicating that GLP-1 receptor agonist might modify plaque composition and increase plaque stability. Histological analysis confirmed that GLP-1 receptor agonist treatment improved smooth muscle cell (SMC)-rich plaque with increased fibrotic content. Furthermore, plaque macrophage infiltration and calcification were significantly reduced by GLP-1 receptor agonist treatment; %SMC area: 6.93 ± 0.31% vs. 8.14 ± 0.48%, p = 0.02; %macrophage area: 9.11 ± 0.80% vs. 6.19 ± 0.85%, p < 0.01; %fibrotic area: 54.75 ± 1.63% vs. 69.60 ± 2.12%, p = 0.02; %calcified area: 3.25 ± 0.67% vs. 0.75 ± 0.15%, p = 0.02). GLP-1 receptor agonist inhibited plaque progression and promoted plaque stabilization by inhibiting plaque growth and modifying plaque composition. Copyright © 2017 Elsevier B.V. All

  13. Mechanism of Residual Lumen Stenosis at the Side Branch Ostium After Final Kissing Balloon Inflation: A Volumetric Intracoronary Ultrasound Study of Coronary Bifurcation Lesions.

    PubMed

    Yamawaki, Masahiro; Murasato, Yoshinobu; Kinoshita, Yoshihisa; Fujii, Kenichi; Fujino, Yoshihisa; Shinke, Toshiro; Takeda, Yoshihiro; Yamada, Shinichiro; Shimada, Yoshihisa; Tsukahara, Reiko; Muramatsu, Toshiya; Suzuki, Takahiko

    2016-04-01

    To investigate the mechanisms of residual stenosis (RS) at side branch ostium (SBO) after final kissing balloon inflation (FKI) and clarify the impact of carina- and plaque-shifts on RS. Carina- and plaque-shift induce SBO compromise. FKI is an effective technique to treat this complication; however, RS often persist, and are associated with restenosis at SBO. We performed serial volumetric analysis of 91 bifurcations in which crossover-stenting with FKI and pre-/post-intravascular ultrasounds (IVUS) were completed in both branches. The plaque- and carina-shifts were defined as an increase in the plaque-volume and a decrease in the vessel-volume at the SBO, respectively. RS at the SBO, defined as area stenosis >50% on IVUS, was identified in 19 lesions. After FKI, the plaque volume- significantly increased at the SBO, with its reduction in the proximal main vessel (MV). However, at the SBO, the volumetric lumen change correlated with vessel change (ρ = 0.690, P < 0.001), but not plaque change (P = 0.390), suggesting that RS at SBO was more likely associated with inadequate vessel stretch, not plaque increase after FKI. Carina-shift was more frequently found in cases with RS, compared to those without RS (37% vs. 11%, P = 0.013). Pre-procedure IVUS findings to predict RS at SBO after FKI were negative-remodeling at distal MV, plaque -burden at distal MV, and plaque-burden at the SBO. Carina-shift has a greater contribution to the formation of RS at SBO after FKI. The pre-procedure IVUS provides helpful information for predicting the RS after FKI. © 2016, Wiley Periodicals, Inc.

  14. 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

  15. 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

  16. Effects of the Addition of Eicosapentaenoic Acid to Strong Statin Therapy on Inflammatory Cytokines and Coronary Plaque Components Assessed by Integrated Ba